Process for producing oxymethylene polymers

The present invention relates to an improved process for the preparation of oxymethylene polymers, comprising the steps of: a) heterogeneous polymerization of a mixture at the existence of a chain transfer agent and an initiator used for cationic polymerization, wherein the mixture comprises a-1) at least one monomer forming a -CH2-O- unit, and a-2) optionally, at least one comonomer copolymerized with the monomer forming a -CH2-O- unit and provided with at least one C-C bond; b) increasing the temperature to be high enough to enable basically-homogeneous polymer melt besides residual monomers at the end of a polymerization reaction before passivation; c) passivating basically-homogeneous active polymer through supplying a passivant to the polymer and monomer mixture; d) supplying the passivated homogeneous polymer mixture prepared in the steps a) and c) to a hydrolyzation area, wherein the hydrolyzation area is used as a hydrolyzation mixture comprising one or more protic solvents, and ...

Method of polyarylene sulfide crystallization

A method for formation of a semi-crystalline polyarylene sulfide is described. The method can include reaction of sulfur-containing monomer with a dihaloaromatic monomer in an organic amide solvent to form a polymer following by combination of the polymer with a crystallization solution. The crystallization solution is pre-heated and the mixture formed is slowly cooled to crystallize the polymer.

Multi-stage process for forming polyarylene sulfides

A multi-stage process and system for formation of a polyarylene sulfide is described. The multi-stage process can include at least three separate formation stages that can take place in three different reactors. The first stage of the formation process can include reaction of an alkali metal sulfide with an organic amide solvent to form a complex including a hydrolysis product of the solvent and an alkali metal hydrogen sulfide. The second stage of the formation process can include reaction of the complex formed in the first stage with a dihaloaromatic monomer to form a prepolymer, and the third stage can include further polymerization of the prepolymer with additional monomers to form the final product.

Salt byproduct separation during formation of polyarylene sulfide

Methods of forming a polyarylene sulfide and systems as may be utilized in carrying out the methods are described. Included in the formation method is a filtration process for treatment of a mixture, the mixture including a polyarylene sulfide, a salt byproduct of the polyarylene sulfide formation reaction, and a solvent. The filtration process includes maintaining the downstream side of the filter medium at an increased pressure. The downstream pressure can such that the boiling temperature of the mixture at the downstream pressure can be higher than the temperature at which the polyarylene sulfide is insoluble in the solvent.

Salt Byproduct Separation During Formation of Polyarylene Sulfide

Methods of forming a polyarylene sulfide and systems as may be utilized in carrying out the methods are described. Included in the formation method is a filtration process for treatment of a mixture, the mixture including a polyarylene sulfide, a salt byproduct of the polyarylene sulfide formation reaction, and a solvent. The filtration process includes maintaining the downstream side of the filter medium at an increased pressure. The downstream pressure can such that the boiling temperature of the mixture at the downstream pressure can be higher than the temperature at which the polyarylene sulfide is insoluble in the solvent. 1. A method for forming a polyarylene sulfide comprising:reacting a dihaloaromatic compound with an alkali metal sulfide or an alkali metal hydrosulfide in an organic amide solvent to form a polyarylene sulfide and a salt;subjecting a mixture including the polyarylene sulfide, the salt, and the organic amide solvent to a filtration process in which the mixture flows to a filter medium from upstream of the filter medium and in which a filtrate flows away from the filter medium in a downstream direction, the salt being retained on the filter medium during the filtration process and forming a filter cake, the filtration process having a downstream pressure, the downstream pressure being elevated above atmospheric pressure, the boiling temperature of the mixture at the downstream pressure being greater than the minimum temperature at which the polyarylene sulfide is fully soluble in the solvent, the filtration having an upstream pressure, the upstream pressure being greater than the downstream pressure for at least a portion of the filtration process, the filtration being carried out in a temperature range that is less than the boiling temperature of the mixture at the downstream pressure and that is greater than the minimum temperature at which the polyarylene sulfide is fully soluble in the solvent.2. The method of claim 1 , further comprising ...

Salt byproduct separation during formation of polyarylene sulfide

Methods of forming a polyarylene sulfide and systems as may be utilized in carrying out the methods are described. Included in the formation method is a filtration process for treatment of a mixture, the mixture including a polyarylene sulfide, a salt byproduct of the polyarylene sulfide formation reaction, and a solvent. The filtration process includes maintaining the downstream side of the filter medium at an increased pressure. The downstream pressure can such that the boiling temperature of the mixture at the downstream pressure can be higher than the temperature at which the polyarylene sulfide is insoluble in the solvent.

Method and system for separation of a polymer from multiple compounds

Methods, devices, and systems that can be utilized in separating a polymer from other compounds of a polymer formation process are described. The methods utilize multiple sedimentors in a countercurrent flow design in conjunction with different solvent solutions in the multiple sedimentors to separate a product polymer from other compounds of a polymer formation process. The sedimentors include feed inlets that can encourage contact between countercurrent flows and improve mass transfer rates between the countercurrent flows.

Process for the production of trioxane

The present invention relates to a process for producing cyclic acetal comprising i) preparing a liquid reaction mixture comprising a) formaldehyde source, b) an aprotic compound and c) a catalyst; and ii) converting the formaldehyde source into cyclic acetals.

Process for producing a cyclic acetal in a heterogeneous reaction system

A process for producing a cyclic acetal is disclosed. According to the process, a formaldehyde source is combined with an aprotic compound and contacted with a heterogeneous catalyst which causes the formaldehyde source to convert into a cyclic acetal such as trioxane. The catalyst, for instance, may comprise a solid catalyst such as an ion exchange resin. In one embodiment, the process is used for converting anhydrous formaldehyde gas to trioxane. The anhydrous formaldehyde gas may be produced form an aqueous formaldehyde solution by an extractive distillation.

Method of Polyarylene Sulfide Crystallization

A method for formation of a semi-crystalline polyarylene sulfide is described. The method can include reaction of sulfur-containing monomer with a dihaloaromatic monomer in an organic amide solvent to form a polymer following by combination of the polymer with a crystallization solution. The crystallization solution is pre-heated and the mixture formed is slowly cooled to crystallize the polymer. 1. A method for forming a semi-crystalline polyarylene sulfide comprising:polymerizing a first sulfur-containing monomer and a first dihaloaromatic monomer in an organic amide solvent to form a polyarylene sulfide prepolymer;polymerizing the polyarylene sulfide prepolymer with a second dihaloaromatic monomer and a second sulfur-containing monomer to form a polyarylene sulfide;combining the polyarylene sulfide with a crystallization solution to form a polymer mixture, the mixture including the crystallization solution in an amount of about 5 wt. % or greater by weight of the mixture, wherein the crystallization solution is pre-heated prior to combination with the polyarylene sulfide, the polymer mixture being at a temperature of about 230° C. or greater upon formation; andcooling the polymer mixture at a rate of about 0.5° C. per minute or less until the polymer mixture reaches a temperature of about 190° C. or less, the polyarylene sulfide crystallizing during the cooling to form the semi-crystalline polyarylene sulfide.2. The method of claim 1 , wherein the crystallization solution is pre-heated to a temperature from about 50° C. to about 200° C.3. The method of claim 1 , wherein the crystallization solution comprises water.4. The method of claim 3 , wherein the mixture includes the crystallization solution in an amount of from about 3 wt. % to about 10 wt. % by weight of the mixture.5. The method of claim 1 , wherein the crystallization solution includes an acid.6. The method of claim 5 , wherein the method comprises formation of a hydrogen sulfide by-product claim 5 , ...

Process for producing a cyclic acetal

The present invention relates to a process for producing cyclic acetal comprising i) preparing a reaction mixture comprising a) a formaldehyde source in a liquid medium and b) a catalyst; ii) converting the formaldehyde source into cyclic acetals, wherein the final conversion of said formaldehyde source to said cyclic acetal is greater than 10% on basis of the initial formaldehyde source.

Polyoxymethylene Nanoparticles

The synthesis of nanoparticles based on hyperbranched-linear-hyperbranched ABA triblock copolymers with hyperbranched polyglycerol (hbPG) as A-block and linear poly(oxymethylene) as B-block is described. The acid-degradable nanoparticles were formed in a facile process, combining a solvent evaporation process with the miniemulsion technique resulting in particles with a diameter in the range of 190 to 250 nm and a standard deviation of ˜30% determined with DLS and SEM. The nanoparticles were placed on a silicon wafer and sintered leading to films with a thickness in the μm-range investigated via SEM. The surface properties of these films were investigated via static contact angle measurements at the liquid/vapor interface. The contact angle decreases from 67° for the polymer with two hydroxyl groups to 29° for the polymer with 16 hydroxyl groups, confirming the influence of the polymer structure and size of the hbPG block on the surface properties. 1. Polymer particles comprising polyoxymethylene nanoparticles , the nanoparticles having an average particle size of from about 20 nm to about 700 nm as measured by dynamic light scattering.2. Polymer particles as defined in claim 1 , wherein the nanoparticles consist of a polyoxymethylene polymer.3. Polymer particles as defined in claim 1 , wherein the nanoparticles comprise a polyoxymethylene polymer having a number average molecular weight of from about 500 g/mol to about 50 claim 1 ,000 g/mol.4. Polymer particles as defined in claim 1 , wherein the nanoparticles comprise a polyoxymethylene copolymer.5. Polymer particles as defined in claim 1 , wherein the nanoparticles comprise a polyoxymethylene triblock copolymer.6. Polyoxymethylene particles as defined in claim 5 , wherein the polyoxymethylene triblock copolymer includes a middle portion between a first end portion and a second end portion claim 5 , the first and second end portions comprising hyperbranched portions.7. Polyoxymethylene particles as defined in ...

Process for the production of trioxane from aqueous formaldehyde sources

The present invention relates to a process for producing cyclic acetal comprising i) preparing a liquid reaction mixture comprising a) a formaldehyde source, b) an aprotic compound and c) a catalyst; wherein the total amount of protic compounds is less than 40 wt.-%, based on the total weight of the reaction mixture; and ii) converting the formaldehyde source into cyclic acetals.

Process For Recycling Polyacetals

A process for recycling polyoxymethylene polymers is disclosed. A polyoxymethylene polymer is at least partially dissolved in an aprotic compound. The resulting solution or suspension (liquid mixture) is then contacted with a catalyst which causes the polyoxymethylene polymer to be converted into a cyclic acetal. The cyclic acetal can be separated, collected and used in other processes. In one embodiment, the cyclic acetal may be used to produce a polyoxymethylene polymer. 120.-. (canceled)21. A process for the recycling of oxymethylene homo- or copolymers comprising the steps:a) at least partly dissolving an oxymethylene homo- or copolymer in an aprotic compound;b) converting the at least partly dissolved oxymethylene homo- or copolymer in the presence of a catalyst to cyclic acetals; andc) converting the cyclic acetals obtained in step b) optionally together with comonomer(s) to oxymethylene polymers.22. A process according to claim 21 , wherein at least 20 wt.-% of the oxymethylene homo- or copolymer is dissolved in the aprotic compound.23. A process according to claim 21 , wherein the oxymethylene polymer is at least partly dissolved at a temperature higher than 100° C.24. A process according to claim 21 , wherein the aprotic compound has a boiling point of 120° C. or higher claim 21 , determined at 1 bar.25. A process according to claim 21 , wherein the oxymethylene polymer claim 21 , the aprotic compound and the catalyst form a reaction mixture and wherein the reaction mixture comprises at least 60 wt.-% of the aprotic compound claim 21 , wherein the weight is based on the total weight of the reaction mixture.26. A process according to claim 21 , wherein the aprotic compound comprises a sulfur containing organic compound.27. A process according to claim 21 , wherein the aprotic compound comprises a dipolar nitro-group free compound.29. A process according to claim 21 , wherein the aprotic compound is sulfolane.32. A process according to claim 21 , wherein the ...

Integrated process for producing cyclic acetals and oxymethylene polymers

A process for producing cyclic acetals is described. A formaldehyde source is contacted with an aprotic compound in the presence of a catalyst to produce the cyclic acetals. The aprotic compound can increase conversion rates and/or efficiency. In one embodiment, the formaldehyde source is obtained from methanol. In particular, methanol can be converted into formaldehyde which is then converted into a cyclic acetal. In one embodiment, the cyclic acetal can then be used to produce oxymethylene polymers.

Initiator

An initiator for cationic polymerization comprises a salt of a protic acid as well as a protic add. The molar ratio of protic acid to salt is in the range from 1:0.01 to 1:2000. The initiator is used for example for cationic homo- or copolymerization of trioxane, and permits stable and flexible operation of the polymerization.

Process for Producing Oxymethylene Polymers

The present invention relates to a process for the preparation of oxymethylene polymers, the oxymethylene polymers obtained therefrom as well as their use. 1. A process for the preparation of oxymethylene polymers comprising the following steps: [{'sub': '2', 'a-1) at least one monomer that forms —CH—O— units, and'}, 'a-2) optionally at least one comonomer copolymerizable therewith and having at least one C—C bond,, 'a) heterogeneous polymerization, in the presence of a chain transfer agent and an initiator for cationic polymerization, of a mixture comprising'}b) raising the temperature during the course of the polymerization sufficiently far that a substantially homogeneous polymer melt is present at the end of polymerization prior to deactivation alongside remaining residual monomers,c) deactivating the active polymer chains in a substantially homogeneous phase by feeding a deactivator into the polymer and monomer mixture,d) feeding the deactivated homogeneous polymer mixture prepared in step a) to c) to a hydrolysis zone as a hydrolysis mixture comprising one or more protic solvent(s) and wherein said polymer mixture is subjected to hydrolysis in the presence of protic solvent at a temperature which is higher than the melting point of the polymer mixture prepared in step a) to c); ande) precipitating the hydrolyzed oxymethylene polymer from the solution prepared in step d).2. The process according to claim 1 , wherein the chain transfer agent is an acetal of formaldehyde.4. The process according to claim 3 , wherein Rand/or Ris methyl.5. The process according to claim 3 , wherein q is 1.7. The process according to wherein the molar ratio of protic acid to salt is in the range from 1:0.01 to 1:2000.8. The process according to claim 6 , wherein the molar ratio of protic acid to salt is in the range from 1:0.5 to 1:10.9. The process according to claim 6 , wherein the molar ratio of protic acid to salt is in the range from 1:1 to 1:4.10. The process according to ...

GASIFIER FOR SOLID CARBON FUEL

Gasifiers for the gasification of solid carbon-based fuels are disclosed herein. An example gasifier includes an inlet chamber for introducing fuel into the gasifier and a pyrolysis region for pyrolyzing the fuel introduced into the vessel. The pyrolysis region includes first means for admission of a pyrolysis agent. The example gasifier also includes a combustion region for incinerating pyrolysis gases originating from the pyrolysis region, where the combustion region includes second means for admission of a gasifying agent. Also, the example gasifier includes a reduction region for gasifying carbonized fuel originating from the pyrolysis region, an outlet for collecting gases originating from the reduction region, and a region for collecting and discharging ashes. In addition, the example gasifier includes active transfer means to actively transfer solid material from the pyrolysis region to the reduction region. In some examples, the active transfer means is located between the pyrolysis region and the combustion region, and the active transfer means includes a transfer chamber to prevent a direct flow of the solid material from the pyrolysis region to the reduction region, where the transfer chamber is permeable to the pyrolysis gases. 113-. (canceled)14. A cocurrent fixed bed gasifier for the gasification of solid carbon-based fuel , the gasifier comprising a vertical vessel successively comprising , from the top downward:an inlet chamber for introducing fuel into the gasifier;a pyrolysis region for pyrolyzing the fuel introduced into the vessel, the pyrolysis region comprising first means for admission of a pyrolysis agent;active transfer means to actively transfer solid material from the pyrolysis region to a reduction region, the active transfer means comprising a transfer chamber configured to prevent a direct flow of the solid material from the pyrolysis region to the reduction region, the transfer chamber being permeable to pyrolysis gases originating ...

GASIFIER FOR SOLID CARBON FUEL

Gasifiers for the gasification of solid carbon-based fuels are disclosed herein. An example gasifier includes an inlet chamber for introducing fuel into the gasifier and a pyrolysis region for pyrolyzing the fuel introduced into the vessel. The pyrolysis region includes first means for admission of a pyrolysis agent. The example gasifier also includes a combustion region for incinerating pyrolysis gases originating from the pyrolysis region, where the combustion region includes second means for admission of a gasifying agent. Also, the example gasifier includes a reduction region for gasifying carbonized fuel originating from the pyrolysis region, an outlet for collecting gases originating from the reduction region, and a region for collecting and discharging ashes. In addition, the example gasifier includes active transfer means to actively transfer solid material from the pyrolysis region to the reduction region. In some examples, the active transfer means is located between the pyrolysis region and the combustion region, and the active transfer means includes a transfer chamber to prevent a direct flow of the solid material from the pyrolysis region to the reduction region, where the transfer chamber is permeable to the pyrolysis gases. 1. A cocurrent fixed bed gasifier for the gasification of solid carbon-based fuel , the gasifier comprising a vertical vessel successively comprising , from the top downward:an inlet chamber for introducing fuel into the gasifier;a pyrolysis region for pyrolyzing the fuel introduced into the vessel, the pyrolysis region including first means for admission of a pyrolysis agent;active transfer means to actively transfer solid material from the pyrolysis region to a reduction region, the active transfer means including a transfer chamber configured to prevent a direct flow of the solid material from the pyrolysis region to the reduction region, the transfer chamber being permeable to pyrolysis gases originating from the pyrolysis ...

Multi-stage Process for Forming Polyarylene Sulfides

A multi-stage process and system for formation of a polyarylene sulfide is described. The multi-stage process can include at least three separate formation stages that can take place in three different reactors. The first stage of the formation process can include reaction of an alkali metal sulfide with an organic amide solvent to form a complex including a hydrolysis product of the solvent and an alkali metal hydrogen sulfide. The second stage of the formation process can include reaction of the complex formed in the first stage with a dihaloaromatic monomer to form a prepolymer, and the third stage can include further polymerization of the prepolymer with additional monomers to form the final product. 1. A multi-stage method for forming a polyarylene sulfide comprising:reacting a complex with a first dihaloaromatic monomer to form a polyarylene sulfide prepolymer, the complex including an alkali metal organic amine carboxylic acid salt and an alkali metal hydrogen sulfide;thereafter, carrying out a second polymerization reaction in which the polyarylene sulfide prepolymer is reacted in the organic amide solvent to form the polyarylene sulfide, wherein the molar ratio of any water present in the second polymerization reaction to the sulfur-containing monomer of the second polymerization reaction is less than about 0.2.2. The method of claim 1 , wherein the reaction to form the prepolymer takes place in a first reactor and the second polymerization reaction to form the polyarylene sulfide takes place in a second reactor.3. The method of claim 1 , further comprising reacting a second organic amide solvent claim 1 , an alkali metal sulfide claim 1 , and water to form the complex including the alkali metal organic amine carboxylic acid salt and the alkali metal hydrogen sulfide.4. The method of claim 3 , wherein the formation of the complex takes place in a third reactor.5. The method of claim 3 , wherein the reaction to form the prepolymer take place in a first ...

Salt Byproduct Separation During Formation of Polyarylene Sulfide

Methods of forming a polyarylene sulfide and systems as may be utilized in carrying out the methods are described. Included in the formation method is a filtration process for treatment of a mixture, the mixture including a polyarylene sulfide, a salt byproduct of the polyarylene sulfide formation reaction, and a solvent. The filtration process includes maintaining the downstream side of the filter medium at an increased pressure. The downstream pressure can such that the boiling temperature of the mixture at the downstream pressure can be higher than the temperature at which the polyarylene sulfide is insoluble in the solvent. 1. A method for forming a polyarylene sulfide comprising:reacting a dihaloaromatic compound with an alkali metal sulfide or an alkali metal hydrosulfide in an organic amide solvent to form a polyarylene sulfide and a salt;subjecting a mixture including the polyarylene sulfide, the salt, and the organic amide solvent to a filtration process in which the mixture flows to a filter medium from upstream of the filter medium and in which a filtrate flows away from the filter medium in a downstream direction, the salt being retained on the filter medium during the filtration process and forming a filter cake, the filtration process having a downstream pressure, the downstream pressure being elevated above atmospheric pressure, the boiling temperature of the mixture at the downstream pressure being greater than the minimum temperature at which the polyarylene sulfide is fully soluble in the solvent, the filtration having an upstream pressure, the upstream pressure being greater than the downstream pressure for at least a portion of the filtration process, the filtration being carried out in a temperature range that is less than the boiling temperature of the mixture at the downstream pressure and that is greater than the minimum temperature at which the polyarylene sulfide is fully soluble in the solvent.2. The method of claim 1 , further comprising ...

Method of Polyarylene Sulfide Crystallization

A method for formation of a semi-crystalline polyarylene sulfide is described. The method can include reaction of sulfur-containing monomer with a dihaloaromatic monomer in an organic amide solvent to form a polymer following by combination of the polymer with a crystallization solution. The crystallization solution is pre-heated and the mixture formed is slowly cooled to crystallize the polymer. 1. A method for forming a semi-crystalline polyarylene sulfide comprising:polymerizing a first sulfur-containing monomer and a first dihaloaromatic monomer in an organic amide solvent to form a polyarylene sulfide prepolymer;polymerizing the polyarylene sulfide prepolymer with a second dihaloaromatic monomer and a second sulfur-containing monomer to form a polyarylene sulfide;combining the polyarylene sulfide with a crystallization solution to form a polymer mixture, the mixture including the crystallization solution in an amount of about 5 wt. % or greater by weight of the mixture, wherein the crystallization solution is pre-heated prior to combination with the polyarylene sulfide, the polymer mixture being at a temperature of about 230° C. or greater upon formation; andcooling the polymer mixture at a rate of about 0.5° C. per minute or less until the polymer mixture reaches a temperature of about 190° C. or less, the polyarylene sulfide crystallizing during the cooling to form the semi-crystalline polyarylene sulfide.2. The method of claim 1 , wherein the crystallization solution is pre-heated to a temperature from about 50° C. to about 200° C.3. The method of claim 1 , wherein the crystallization solution comprises water.4. The method of claim 3 , wherein the mixture includes the crystallization solution in an amount of from about 3 wt. % to about 10 wt. % by weight of the mixture.5. The method of claim 1 , wherein the crystallization solution includes an acid.6. The method of claim 5 , wherein the method comprises formation of a hydrogen sulfide by-product claim 5 , ...

Method and System for Separation of a Polymer from Multiple Compounds

Methods, devices, and systems that can be utilized in separating a polymer from other compounds of a polymer formation process are described. The methods utilize multiple sedimentors in a countercurrent flow design in conjunction with different solvent solutions in the multiple sedimentors to separate a product polymer from other compounds of a polymer formation process. The sedimentors include feed inlets that can encourage contact between countercurrent flows and improve mass transfer rates between the countercurrent flows. 1. A method for separating a solid polymer from multiple compounds comprising:introducing a first slurry into a first sedimentor, the first slurry including the solid polymer, a liquid carrier, and multiple compounds of formation of the polymer;introducing a first solvent into the first sedimentor, the first slurry flowing through the first sedimentor countercurrent to the first solvent within at least a portion of the first sedimentor, one or more compounds of formation of the polymer being soluble in the first solvent, the one or more first solvent soluble compounds transferring from the first slurry to the first solvent within the first sedimentor, the first slurry thus being transformed and forming a second slurry;introducing the second slurry into a second sedimentor;introducing a second solvent into the second sedimentor, the second solvent differing from the first solvent, the second slurry flowing through the second sedimentor countercurrent to the second solvent within at least a portion of the second sedimentor, one or more compounds of formation of the polymer being soluble in the second solvent, the one or more second solvent soluble compounds transferring from the second slurry to the second solvent within the second sedimentor, the second slurry thus being transformed and forming a third slurry.2. The method of claim 1 , wherein one of the first solvent and the second solvent is an organic solvent and other solvent is an aqueous ...

Process For Producing Polyoxymethylene Polymers With Long-Chain Alkyl End Groups, and Polymers Made Therefrom

A polyoxymethylene polymer is disclosed that contains long-chain alkyl end groups. The polyoxymethylene polymer may be formed by using a Bis-alkylformal as a chain transfer agent during production of the polymer. In one embodiment, the Bis-alkylformal is dissolved in a monomer, such as trioxane, during production of the polymer. In one embodiment, a branching agent may also be present with one or more monomers for producing a branched polyoxymethylene polymer. In this manner, greater amounts of alkyl end groups can be incorporated into the polymer. The resulting polymer has excellent flow characteristics. The polymer may be used to form various molded articles with excellent tribological properties. 1. A process for producing a polyoxymethylene polymer comprising:{'sub': '2', 'combining a monomer that forms —CH—O— units with a transfer agent and an initiator, the transfer agent comprising a Bis-alkylformal, the Bis-alkylformal including alkyl end groups having a linear or branched carbon chain length of at least 10 carbon atoms;'}polymerizing the monomer while raising the temperature, the pressure, or both the temperature and pressure during polymerization an amount sufficient for the Bis-alkylformal to dissolve in the monomer, and wherein the Bis-alkylformal reacts during the polymerization such that the linear or branched alkyl end groups on the Bis-alkylformal form end groups on the polyoxymethylene polymer; andadding a deactivator to deactivate the polymerization.2. A process as defined in claim 1 , wherein the formed polyoxymethylene polymer comprises a substantially homogeneous polymer melt when the deactivator is added.3. A process as defined in claim 1 , further comprising the step of degrading unstable chain ends on the formed polyoxymethylene polymer through hydrolysis.5. A process according to claim 1 , wherein the Bis-alkylformal comprises Bis-stearylformal or Bis-eicosanylformal.6. A process as defined in claim 1 , wherein the Bis-alkylformal includes ...

Polyoxymethylene Polymer With Long Chain Alkylene Glycol End Groups

A polyoxymethylene polymer is disclosed that contains long-chain alkylene glycol end groups. The polyoxymethylene polymer may be formed by using a Bis-oligo-alkylene glycol-formal as a chain transfer agent during production of the polymer. The end groups on the polyoxymethylene polymer may comprise ethylene oxide end groups and/or propylene oxide end groups. The resulting polymer has excellent flow characteristics and may be used as a flow additive for other thermoplastic polymers. Alternatively, the polymer may be used to form various molded articles with excellent tribological properties. 1. A thermoplastic polymer comprising:a polyoxymethylene polymer with alkylene oxide end groups, the alkylene oxide end groups having an average molecular weight of from about 350 g/mol to about 10,000 g/mol.3. A thermoplastic polymer as defined in wherein n is from 12 to 60.5. A thermoplastic polymer as defined in claim 2 , where R is an alkyl group having a carbon chain length of less than about 10 carbon atoms.6. A thermoplastic polymer as defined in claim 5 , wherein R is an ethyl or methyl group.7. A polymer composition comprising:a thermoplastic polymer combined with a flow additive, the flow additive comprising a polyoxymethylene polymer with alkylene oxide end groups, the alkylene oxide end groups having an average molecular weight of from about 350 g/mol to about 10,000 g/mol.8. A polymer composition as defined in claim 7 , wherein the alkylene oxide end groups have an average molecular weight of from about 500 g/mol to about 5000 g/mol.9. A polymer composition as defined in claim 7 , wherein the thermoplastic polymer comprises a second polyoxymethylene polymer claim 7 , the second polyoxymethylene polymer not including the alkylene oxide end groups.11. A polymer composition as defined in claim 7 , wherein the alkylene oxide end groups comprise monoalkylated alkylene oxide end groups.12. A polymer composition as defined in claim 7 , wherein the alkylene oxide end groups ...

GASIFIER FOR A SOLID CARBON FUEL

Disclosed here are example gasifiers for gasification of solid carbon fuel. An example gasifier includes a vertical vessel that includes feeding means for introducing a fuel at a top and along a first vertical axis in the vessel. The example vessel also includes a pyrolysis zone for pyrolysis of the fuel, a combustion zone for burning pyrolysis gases from the pyrolysis zone, a reduction zone for gasifying carbonized fuel from the pyrolysis zone and an outlet for collecting gases produced in the reduction zone. In addition, the example vessel includes a horizontal plate fixedly mounted between the feeding means and the pyrolysis zone for receiving and retaining the fuel introduced into the vessel. Also, the example vessel includes a movable pusher mounted between the feeding means and the horizontal plate, the movable pusher to push the fuel retained on the horizontal plate into the pyrolysis zone and positioned or positionable above the horizontal plate. 1. A gasifier comprising a vertical vessel comprising:feeding means for introducing a fuel at a top and along a first vertical axis in the vessel;a pyrolysis zone for pyrolysis of the fuel;a combustion zone for burning pyrolysis gases from the pyrolysis zone;a reduction zone for gasifying carbonized fuel from the pyrolysis zone;an outlet for collecting gases produced in the reduction zone;a horizontal plate fixedly mounted between the feeding means and the pyrolysis zone for receiving and retaining the fuel introduced into the vessel; anda movable pusher mounted between the feeding means and the horizontal plate, the movable pusher to push the fuel retained on the horizontal plate into the pyrolysis zone and positioned or positionable above the horizontal plate.2. The gasifier as claimed in claim 1 , wherein the movable pusher comprises at least one arm extending horizontally above the plate and mounted rotatably about a second vertical axis.3. The gasifier as claimed in claim 2 , wherein the second axis is offset ...

INITIATOR

An initiator for cationic polymerization comprises a salt of a protic acid as well as a protic add. The molar ratio of protic acid to salt is in the range from 1:0.01 to 1:2000. The initiator is used for example for cationic homo- or copolymerization of trioxane, and permits stable and flexible operation of the polymerization. 19-. (canceled)11. A polymer according to claim 10 , wherein the protic acid is trifluoromethanesulfonic acid claim 10 , pentafluoroethanesulfonic acid claim 10 , heptafluoropropanesulfonic acid claim 10 , nonafluorobutanesulfonic acid claim 10 , perfluoropentanesulfonic acid claim 10 , perfluorohexanesulfonic acid or perfluoroheptanesulfonic acid.12. A polymer according to claim 10 , wherein where R-Rare independently hydrogen claim 10 , methyl claim 10 , ethyl claim 10 , n-propyl claim 10 , isopropyl claim 10 , n-butyl claim 10 , isobutyl or 4-methoxyphenyl. This application is based on and claims priority to U.S. Provisional Patent Application No. 60/847,268, filed Sep. 26, 2006.The present invention concerns an initiator for cationic polymerization. This invention also concerns a process for cationic polymerization of monomers in the presence of the initiator and polymers produced by means of the process.Cationic polymerization is an ionic polymerization which proceeds via a stepwise reaction of monomer molecules at positively charged active sites. A number of monomers can be polymerized by this method. Examples of such monomers are olefins, vinyl ethers, vinylarenes such as styrene, but in particular compounds comprising heteroatoms such as ethers, thioethers, oxiranes, oxazolines, esters and acetals. Known initiators for cationic polymerization are protic acids such as perchloric acid or trifiuoro-methanesulfonic acid or Lewis acids such as boron trifluoride or aluminum trichloride.Cationic polymerization has achieved particular importance in relation to the production of polyacetals, which are prepared by polymerization of aldehydes via ...

POLYOXYMETHYLENE COPOLYMER SUITED FOR USE IN LIQUID SYSTEMS

A water soluble polyoxymethylene copolymer is described. In one embodiment, the polyoxymethylene copolymer is a liquid at 35° C. and is water soluble. The polyoxymethylene copolymer may have a comonomer content of greater than about 60% by weight, such as greater than about 70% by weight, such as greater than about 80% by weight. The copolymer is usually formed using a chain transfer agent. The polyoxymethylene copolymer can be formed so as to have a relatively low molecular weight and have a relatively great amount of end groups or terminal groups. For instance, the copolymer may contain end groups in an amount greater than 300 mmol/kg. 1. A polyoxymethylene polymer composition comprising a polyoxymethylene copolymer containing 1 ,3-dioxolane units in an amount greater than about 60% by weight , the copolymer containing end groups in an amount greater than 300 mmol/kg.2. A polyoxymethylene polymer composition as defined in claim 1 , wherein the copolymer contains hemiformal terminal groups in an amount less than about 60 mmol/kg.3. A polyoxymethylene polymer composition as defined in claim 1 , wherein the polymer is formed from the reaction product of trioxane claim 1 , 1 claim 1 ,3-dioxolane claim 1 , a chain transfer agent claim 1 , and a catalyst.4. A polyoxymethylene polymer composition as defined in claim 3 , wherein the polymer has a molecular weight of from about 500 to about 7 claim 3 ,000.5. A polyoxymethylene polymer composition as defined in claim 3 , wherein the chain transfer agent comprises methylal claim 3 , butylal claim 3 , ethylene glycol claim 3 , diethylene glycol claim 3 , triethylene glycol or mixtures thereof.6. A polyoxymethylene polymer composition as defined in claim 2 , wherein the catalyst comprises triflic acid claim 2 , perchloric acid claim 2 , boron trifluoride claim 2 , or mixtures thereof.7. A polyoxymethylene polymer composition as defined in claim 1 , wherein the copolymer contains dioxolane units in an amount from about 55% by ...

Process For The Production of Trioxane

The present invention relates to a process for producing cyclic acetal comprising i) preparing a liquid reaction mixture comprising a) formaldehyde source, b) an aprotic compound and c) a catalyst; and ii) converting the formaldehyde source into cyclic acetals. 1. A process for producing a cyclic acetal comprising:contacting a formaldehyde source with a liquid medium comprising a sulfur-containing organic compound in the presence of a catalyst; andat least partially converting the formaldehyde source into a cyclic acetal.2. (canceled)3. A process according to claim 1 , wherein the sulfur-containing organic compound has a boiling point of 140° C. or higher claim 1 , determined at 1 bar.4. (canceled)5. (canceled)6. A process according to wherein higher than 50% of the formaldehyde source is converted into one or more cyclic acetals during the reaction.7. A process according to wherein the liquid medium comprises at least 60 wt.-% claim 1 , of the sulfur-containing organic compound.8. A process according to claim 1 , wherein the sulfur-containing organic compound is selected from the group consisting of organic sulfoxides claim 1 , organic sulfones claim 1 , organic sulfonate esters claim 1 , and mixtures thereof.9. A process according to wherein the sulfur-containing organic compound is selected from the group consisting of cyclic or alicyclic organic sulfoxides claim 1 , alicyclic or cyclic sulfones claim 1 , and mixtures thereof.11. A process according to wherein the sulfur-containing organic compound is sulfolane.14. (canceled)15. A process according to wherein the formaldehyde source and the sulfur-containing organic compound form a homogeneous phase.16. (canceled)17. A process according to wherein the reaction produces trioxane and tetroxane.18. (canceled)19. A process according to wherein during the process a reaction mixture includes the formaldehyde source claim 1 , the sulfur-containing organic compound claim 1 , and the catalyst claim 1 , and wherein the ...

Process for Recycling A Formaldehyde Source During A Polymerization Process

A process for recovering volatile components from an oxymethylene polymer process is disclosed. The volatile components are removed from the process and the formaldehyde collected is converted to a cyclic acetal. The formaldehyde is converted to a cyclic acetal by contacting the formaldehyde with a catalyst in the presence of an aprotic solvent. 1. A process for producing oxymethylene homo- or copolymers comprising:a) polymerizing at least one monomer to form an oxymethylene polymer in the presence of an initiator;b) deactivating the polymerization;c) removing residual monomers containing formaldehyde;d) contacting the formaldehyde with an aprotic compound and a catalyst; ande) at least partly converting the formaldehyde to a cyclic acetal.2. (canceled)3. (canceled)4. A process according to wherein at least 50 wt.-% claim 1 , of the monomer is converted to the oxymethylene homo- or copolymer prior to removing the residual monomers containing formaldehyde and wherein the wt.-% refers to the total weight of the monomers.5. A process according to claim 1 , wherein the polymerization is deactivated prior to the removal of the residual monomers containing formaldehyde.6. A process according to wherein the formaldehyde is removed as a gaseous mixture together with residual monomers.7. A process according to wherein the polymerization process uses trioxane and/or tetroxane as a monomer; and optionally includes a comonomer.8. (canceled)9. (canceled)10. (canceled)11. A process according to wherein the aprotic compound has a boiling point of 120° C. or higher claim 1 , determined at 1 bar.12. A process according to wherein the formaldehyde claim 1 , the aprotic compound and the catalyst form a reaction mixture and wherein the reaction mixture comprises at least 60 wt.-% claim 1 , of the aprotic compound claim 1 , wherein the weight is based on the total weight of the reaction mixture.13. A process according to wherein the aprotic compound comprises a sulfur containing organic ...

Block Copolymers Based on Linear Poly(oxymethylene)(POM) and Hyperbranched Poly(glycerol): Combining Polyacetals with Polyethers

Synthesis of hyperbranched-linear-hyperbranched ABA triblock copolymers based on linear poly(oxy methylene) (POM) and hyperbranched poly(glycerol) (hbPG) blocks is described. The polymers having a polyacetal polyether structure were prepared from linear bishydroxy functional POM macroinititators, obtained by cationic ring-opening polymerization of trioxane and dioxane with formic acid as transfer agent and following hydrolysis of the formiate group. Partial deprotonation of the resulting hydroxyl groups permitted the hypergrafting by anionic ring-opening multibranching polymerization (ROMBP) of glycidol. 1. A polymer comprising a hyperbranched polyoxymethylene homopolymer or copolymer , the polyoxymethylene homopolymer or copolymer comprising a middle portion positioned between a first end portion and a second end portion , at least one of the end portions having a hyperbranched structure.2. A polymer as defined in claim 1 , wherein both end portions have a hyperbranched structure.3. A polymer as defined in claim 1 , wherein the middle portion comprises a linear structure having repeating oxymethylene units and optionally other oxyalkylene units.4. A polymer as defined in claim 1 , wherein the hyperbranched polyoxymethylene polymer comprises a triblock copolymer.5. A polymer as defined in claim 1 , wherein each hyperbranched portion includes at least 10 branches per molecule and generally less than about 500 branches per molecule.6. A polymer as defined in claim 1 , wherein each hyperbranched portion includes end units and wherein the end units comprise functional groups.7. A polymer as defined in claim 6 , wherein at least about 80% of the end units comprise the functional groups.8. A polymer as defined in claim 6 , wherein the functional groups comprise hydroxyl groups claim 6 , amino groups claim 6 , alkoxyl groups claim 6 , esters or amides.9. A polymer as defined in claim 1 , wherein the hyperbranched portions are aliphatic.10. A polymer as defined in claim 1 , ...

Integrated Process for Producing Cyclic Acetals and Oxymethylene Polymers

A process for producing cyclic acetals is described. A formaldehyde source is contacted with an aprotic compound in the presence of a catalyst to produce the cyclic acetals. The aprotic compound can increase conversion rates and/or efficiency. In one embodiment, the formaldehyde source is obtained from methanol. In particular, methanol can be converted into formaldehyde which is then converted into a cyclic acetal. In one embodiment, the cyclic acetal can then be used to produce oxymethylene polymers. 1. A process for producing a cyclic acetal comprising:converting methanol to a formaldehyde;contacting the formaldehyde with a catalyst in the presence of an aprotic compound; andat least partly converting the formaldehyde to a cyclic acetal.2. (canceled)3. A process according to claim 1 , wherein the methanol is dehydrogenated in order to form the formaldehyde.4. A process according to claim 1 , wherein the formaldehyde is formed by nonoxidative dehydrogenation of methanol.5. A process according to claim 1 , wherein the formaldehyde is formed by dehydrogenating methanol at a temperature of from about 300° C. to about 1100° C.6. A process according to claim 1 , wherein the formaldehyde is formed in the presence of a catalyst comprising an alkali metal claim 1 , an alkaline earth metal claim 1 , copper claim 1 , zinc claim 1 , tin claim 1 , compounds thereof claim 1 , or mixtures thereof.7. A process according to claim 1 , wherein the formaldehyde is formed by extractive distillation.8. A process according to claim 1 , wherein the methanol is oxidized to form the formaldehyde.9. A process according to claim 7 , wherein the extractive distillation is carried out by feeding crude formaldehyde containing water and methanol to a middle or lower part of a distillation column and feeding an extractant to an upper part of the distillation column claim 7 , the extractant being inert to formaldehyde claim 7 , and wherein formaldehyde gas is collected from a top of the ...

Process For The Production Of Trioxane From Aqueous Formaldehyde Sources

The present invention relates to a process for producing cyclic acetal comprising i) preparing a liquid reaction mixture comprising a) a formaldehyde source, b) an aprotic compound and c) a catalyst; wherein the total amount of protic compounds is less than 40 wt.-%, based on the total weight of the reaction mixture; and ii) converting the formaldehyde source into cyclic acetals. 1. A process for producing a cyclic acetal comprising:reacting a formaldehyde source in the presence of a catalyst to produce a cyclic acetal, and wherein the reaction is carried out in a liquid medium comprising a liquid aprotic compound having a boiling point of 120° C. or higher determined at 1 bar, and wherein the amount of the liquid aprotic compound comprises at least 20 wt % of the liquid medium.2. (canceled)3. (canceled)4. (canceled)5. (canceled)6. A process according to claim 1 , wherein the formaldehyde source is an aqueous formaldehyde solution with a formaldehyde content ranging from about 60 to about 90 wt.-% claim 1 , based on the total weight of the aqueous formaldehyde solution.7. A process according to claim 1 , wherein the aprotic compound has a boiling point of 140° C. or higher claim 1 , determined at 1 bar and wherein the aprotic compound has a relative static permittivity of more than 15.8. (canceled)9. (canceled)10. A process according to wherein the liquid medium comprises at least 40 wt.-% claim 1 , of the aprotic compound.11. A process according to wherein the aprotic compound is selected from the group consisting of organic sulfoxides claim 1 , organic sulfones claim 1 , organic sulfonate esters claim 1 , and mixtures thereof.12. A process according to wherein the aprotic compound is selected from the group consisting of cyclic or alicyclic organic sulfoxides claim 1 , alicyclic or cyclic sulfones claim 1 , and mixtures thereof.14. A process according to wherein the aprotic compound is sulfolane.17. (canceled)18. (canceled)19. (canceled)20. A process according to ...

Process for Producing A Cyclic Acetal

The present invention relates to a process for producing cyclic acetal comprising i) preparing a reaction mixture comprising a) a formaldehyde source in a liquid medium and b) a catalyst; ii) converting the formaldehyde source into cyclic acetals, wherein the final conversion of said formaldehyde source to said cyclic acetal is greater than 10% on basis of the initial formaldehyde source. 1. A process for producing a cyclic acetal comprising:contacting gaseous formaldehyde with a liquid medium comprising a liquid aprotic compound in the presence of a catalyst; andat least partially converting the gaseous formaldehyde into a cyclic acetal.2. (canceled)3. A process according to claim 1 ,wherein the aprotic compound is a polar aprotic compound.4. (canceled)5. A process according to claim 1 , wherein the catalyst is heterogeneous with the liquid medium.6. A process according to claim 1 , wherein the weight ratio of gaseous formaldehyde to the aprotic compound is from about 1:50 to about 1:3.7. A process according to claim 1 , wherein the aprotic compound has a boiling point of 140° C. or higher determined at 1 bar.8. (canceled)9. A process according to wherein higher than 30% claim 1 , of the gaseous formaldehyde is converted into one or more cyclic acetals during the reaction.10. A process according to wherein the liquid medium comprises at least 60 wt.-% claim 1 , of the aprotic compound.11. A process according to wherein the aprotic compound is selected from the group consisting of organic sulfoxides claim 1 , organic sulfones claim 1 , organic sulfonate esters claim 1 , and mixtures thereof.12. A process according to wherein the aprotic compound is selected from the group consisting of cyclic or alicyclic organic sulfoxides claim 1 , alicyclic or cyclic sulfones claim 1 , and mixtures thereof.14. A process according to wherein the aprotic compound is sulfolane.17. (canceled)18. A process according to wherein the reaction is carried out at a temperature ranging from ...

Process for Recycling Polyacetals

A process for recycling polyoxymethylene polymers is disclosed. A polyoyxmethylene polymer is at least partially dissolved in an aprotic compound. The resulting solution or suspension (liquid mixture) is then contacted with a catalyst which causes the polyoxymethylene polymer to be converted into a cyclic acetal. The cyclic acetal can be separated, collected and used in other processes. In one embodiment, the cyclic acetal may be used to produce a polyoxymethylene polymer. 1. A process for the conversion of oxymethylene homo- or copolymers to cyclic acetals comprising the steps:a) at least partly dissolving an oxymethylene homo- or copolymer in a liquid medium comprising an aprotic compound andb) converting the at least partly dissolved oxymethylene homo- or copolymer in the presence of a catalyst to cyclic acetals.2. (canceled)3. (canceled)4. A process according to claim 1 , wherein at least 20 wt.-% claim 1 , of the oxymethylene homo- or copolymer is dissolved in the aprotic compound.5. A process according to wherein the oxymethylene polymer is at least partly dissolved at a temperature higher than 100° C.6. A process according to wherein the cyclic acetals obtained are purified or separated.7. A process according to wherein the aprotic compound is liquid under the dissolution condition.8. A process according to claim 1 , wherein the polyoxymethylene homo- or copolymer has a number average molecular weight (Mn) of more than 2 claim 1 ,000 Dalton.9. A process according to wherein the aprotic compound has a boiling point of 120° C. or higher claim 1 , determined at 1 bar.10. A process according to wherein the oxymethylene polymer claim 1 , the aprotic compound and the catalyst form a reaction mixture and wherein the reaction mixture comprises at least 60 wt.-% claim 1 , of the aprotic compound claim 1 , wherein the weight is based on the total weight of the reaction mixture.11. A process according to wherein the aprotic compound comprises a sulfur containing organic ...

Process for Producing A Cyclic Acetal In A Heterogeneous Reaction System

A process for producing a cyclic acetal is disclosed. According to the process, a formaldehyde source is combined with an aprotic compound and contacted with a heterogeneous catalyst which causes the formaldehyde source to convert into a cyclic acetal such as trioxane. The catalyst, for instance, may comprise a solid catalyst such as an ion exchange resin. In one embodiment, the process is used for converting anhydrous formaldehyde gas to trioxane. The anhydrous formaldehyde gas may be produced form an aqueous formaldehyde solution by an extractive distillation.

Process for the preparation of oxymethylene polymers and apparatus suitable therefor

Beschrieben werden ein Verfahren und eine Vorrichtung zur Herstellung von Oxymethylen-Polymeren. Dieses umfasst die Polymerisation von einem Oxymethylengruppen-bildenden Monomeren, gegebenenfalls in Gegenwart von einem zyklischen Acetal, zusammen mit einem Acetal des Formaldehyds und einem Initiator der kationischen Polymerisation, vorzugsweise in einem gasdichten Kneter oder Extruder. Dabei wird der Temperaturverlauf der Polymerisation derart gestaltet, dass die zunächst durch ausfallendes Polymer heterogene Polymerisationsmischung in eine homogene Phase am Ende der Polymerisation übergeht. Die homogene Phase, in der das Polymer in flüssiger Form vorliegt, wird durch Zugabe von Deaktivatoren stabilisiert. Nach Entfernen von flüchtigen Bestandteilen werden Oxymethylen-Polymere mit hoher thermischer Stabilität und guten mechanischen Eigenschaften erhalten. Die Oxymethylen-Polymeren lassen sich energetisch günstig herstellen und ihre Eigenschaften lassen sich durch Vorgabe des Temperaturprofils während der Polymerisation gezielt einstellen. Described are a method and apparatus for making oxymethylene polymers. This comprises the polymerization of an oxymethylene group-forming monomer, optionally in the presence of a cyclic acetal, together with an acetal of formaldehyde and an initiator of cationic polymerization, preferably in a gas-tight kneader or extruder. In this case, the temperature profile of the polymerization is designed in such a way that the polymerization mixture which is initially heterogeneous by precipitating polymer changes into a homogeneous phase at the end of the polymerization. The homogeneous phase in which the polymer is in liquid form is stabilized by the addition of deactivators. After devolatilization, oxymethylene polymers with high thermal stability and good mechanical properties are obtained. The oxymethylene polymers can be produced energetically low and their properties can be adjusted by specifying the temperature profile during the ...

Process for producing oxymethylene polymers

The present invention relates to an improved process for the preparation of oxymethylene polymers, the oxymethylene polymers obtained therefrom as well as their use.

Method and system for separation of a polymer from multiple compounds

Methods, devices, and systems that can be utilized in separating a polymer from other compounds of a polymer formation process are described. The methods utilize multiple sedimentors in a countercurrent flow design in conjunction with different solvent solutions in the multiple sedimentors to separate a product polymer from other compounds of a polymer formation process. The sedimentors include feed inlets that can encourage contact between countercurrent flows and improve mass transfer rates between the countercurrent flows.

Method of polyarylene sulfide crystallization

A method for formation of a semi-crystalline polyarylene sulfide is described. The method can include reaction of sulfur-containing monomer with a dihaloaromatic monomer in an organic amide solvent to form a polymer following by combination of the polymer with a crystallization solution. The crystallization solution is pre-heated and the mixture formed is slowly cooled to crystallize the polymer.

Homogeneous blends of aromatic polyamides and Poly-N-vinylpyrrolidone, process for preparing and their use

Copolymer from polyarylene sulfide and aromatic polyester

(57)【要約】 【課題】 本発明は、ポリアリーレンスルフィド及び芳 香族ポリエステルからコポリマーの合成及びブレンド、 特にポリアリーレンスルフィドと液晶ポリエステルとの ブレンドを相溶化させるためのその使用を提供する。 【解決手段】 本発明のコポリマーは、 ａ）ｉ）式（Ｉ）： 【化１】 （式中、Ｒ 1 及びＲ 2 基は、互いに独立して、水素、フッ 素、塩素若しくは臭素原子又は、炭素原子１〜６個を有 する分岐若しくは非分岐アルキル若しくはアルコキシ基 である）の構造から誘導された単位１；及び／又は ii）式（II）： 【化２】 の構造から誘導された単位２を有する、1000〜20,000g/ molの数平均分子量Ｍｎを有するセグメントＡ及び ｂ）式（IV）： 【化３】 （式中、Ａｒは芳香族基又は、１個以上の縮合した芳香 族基であり、ｎは２〜100の数、特に５〜20である）の ポリアリーレンスルフィド構造から誘導されたセグメン トＢを含むことを特徴とする。

Process for the preparation of trioxane

Verfahren zur Herstellung von Trioxan aus wässrigen Formaldehydlösungen in Gegenwart saurer Katalysatoren in einer Reaktionskolonne mit Umlaufverdampfer, dadurch gekennzeichnet, daß die als Ausgangslösung verwendete Formaldehydlösung mit einem Seitenstrom aus dem Sumpf der Reaktionskolonne gemischt und über einen Rohrreaktor dem oberen Teil der Reaktionskolonne zugeführt wird. method for the preparation of trioxane from aqueous formaldehyde solutions in Presence of acid catalysts in a reaction column with circulation evaporator, characterized in that the as a starting solution used formaldehyde solution mixed with a side stream from the bottom of the reaction column and over a tubular reactor is fed to the upper part of the reaction column.

Carbonaceous solid fuel gasifier

Process for producing polyoxymethylene polymers with long-chain alkyl end groups, and polymers made therefrom

A polyoxymethylene polymer is disclosed that contains long-chain alkyl end groups. The polyoxymethylene polymer may be formed by using a Bis-alkylformal as a chain transfer agent during production of the polymer. In one embodiment, the Bis-alkylformal is dissolved In a monomer, such as trioxane, during production of the polymer. In one embodiment a branching agent may also be present with one or more monomers for producing a branched polyoxymethylene polymer. In this manner, greater amounts of alkyl end groups can be incorporated into the polymer. The resulting polymer has excellent flow characteristics. The polymer may be used to form various molded articles with excellent tribological properties.

Gasifier for solid carbon fuel

Gazéifieur de combustible solide carboné comportant une cuve verticale (4), ladite cuve comportant successivement, en partant du haut vers le bas : une entrée (5) de combustible solide carboné (2) à gazéifier, une zone de pyrolyse (10) dudit combustible pour produire des gaz de pyrolyse et du « char », une zone de combustion (20) des gaz de pyrolyse, une zone de réduction (30) du « char », une sortie (6) de gaz, et une zone de récolte de cendres (40). La zone de pyrolyse (10) est séparée de la zone de combustion (20) par des moyens de transfert actifs comportant un sas de transfert (50) apte à transférer le combustible (2) de la zone de pyrolyse (10) vers la zone de réduction (30) sans que ledit combustible ne puisse s'écouler directement de la zone de pyrolyse (10) vers la zone de réduction (30), permettant ainsi de mieux contrôler le débit de matière solide entre ces deux zones. Carbonated solid fuel gasifier comprising a vertical tank (4), said tank comprising successively, starting from the top down: an inlet (5) of carbonated solid fuel (2) to be gasified, a pyrolysis zone (10) of said fuel to produce pyrolysis gases and "char", a combustion zone (20) of pyrolysis gases, a reduction zone (30) of "char", a gas outlet (6), and a crop harvesting zone ash (40). The pyrolysis zone (10) is separated from the combustion zone (20) by active transfer means comprising a transfer airlock (50) capable of transferring the fuel (2) from the pyrolysis zone (10) to the zone reduction (30) without said fuel can not flow directly from the pyrolysis zone (10) to the reduction zone (30), thereby better controlling the flow of solid material between these two zones.

Soluble polyarylenesulphoxides, process for the manufacture and use thereof

New soluble linear or branched polyarylene sulphoxides (I). (I), contains arylene sulphoxide units (Ar-SO; Ar = arylene) and have a degree of oxidation of 20-80%. Preferably prepared by homogeneous partial oxidation of polyarylene sulphide with dinitrogen tetroxide in inert medium at -30 to 150 degrees C. In particular, poly-1,4-phenylene sulphide is 50-70% oxidised at 0-30 degrees C.

Gasifier for solid carbon fuel

The invention relates to a gasifier for solid carbon fuel comprising a vertical vat (4), said vat comprising, in series from top to bottom: an inlet (5) for a solid carbon fuel (2) to be gasified; an area (10) for pyrolyzing said fuel so as to produce pyrolysis gases and char; an area (20) for combusting the pyrolysis gases; an area (30) for reducing the char; a gas outlet (6); and an ash-collecting area (40). The pyrolysis area (10) is separated from the combustion area (20) by an active transfer means comprising a transfer airlock (50) capable of transferring the fuel (2) from the pyrolysis area (10) to the reduction area (30) with said fuel being unable to flow directly from the pyrolysis area (10) to the reduction area (30), thus enabling better control of the flow rate of solid matter between said two areas.

Homogeneously mixed alloys comprising aromatic polyamides and poly-n-vinylpyrrolidone, process for their preparation, and their use

Abstract of the disclosure Homogeneously mixed alloys comprising aromatic polyamides and poly-N-vinylpyrrolidone, process for their prepara-tion, and their use Alloys of aromatic polyamides with poly-N-vinylpyrroli-done which are homogeneously mixed and allow the physical and mechanical properties to be adjusted in a targeted way, such as for improving the processability and water-absorption capacity. The PVP, which is water-soluble per se, is not dissolved out of the allows by water. Futher-more, a process for the preparation of the alloys, and their use as molded articles, such as films, coatings or pressings is described.

Production of oxymethylene (co)polymers for molding, including specified homopolymers, involves heterogeneous polymerization of monomer in presence of formaldehyde acetal and cationic initiator and deactivation in basic homogeneous phase

Beschrieben wird eine Vorrichtung zur Herstellung von Oxymethylen-Homo- und -Copolymeren. Dieses umfasst die heterogene Polymerisation von einem Oxymethylengruppen-bildenden Monomeren zusammen mit einem Acetal des Formaldehyds und einem Initiator der kationischen Polymerisation, gefolgt von der Deaktivierung des Polymerisats in homogener Phase durch Behandlung mit einem basischen aprotischen Lösungsmittel oder mit einem aprotischen Lösungsmittel, das eine Base enthält. DOLLAR A Außerdem werden Oxymethylen-Homopolymere mit sehr hoher Stabilität beschrieben.

Gasifier for solid carbon fuel with active transfer means

Gasifiers for the gasification of solid carbon-based fuels are disclosed herein. An example gasifier includes an inlet chamber for introducing fuel into the gasifier and a pyrolysis region for pyrolyzing the fuel introduced into the vessel. The pyrolysis region includes first means for admission of a pyrolysis agent. The example gasifier also includes a combustion region for incinerating pyrolysis gases originating from the pyrolysis region, where the combustion region includes second means for admission of a gasifying agent. Also, the example gasifier includes a reduction region for gasifying carbonized fuel originating from the pyrolysis region, an outlet for collecting gases originating from the reduction region, and a region for collecting and discharging ashes. In addition, the example gasifier includes active transfer means to actively transfer solid material from the pyrolysis region to the reduction region. In some examples, the active transfer means is located between the pyrolysis region and the combustion region, and the active transfer means includes a transfer chamber to prevent a direct flow of the solid material from the pyrolysis region to the reduction region, where the transfer chamber is permeable to the pyrolysis gases.

Process for the copolymerisation of trioxane

Ein Initiator zur kationischen Polymerisation enthält neben einer Protonensäure zusätzlich auch ein Salz einer Protonensäure. Das molare Verhältnis von Protonensäure zu Salz liegt im Bereich von 1 : 0,01 bis 1 : 2.000. Der erfindungsgemäße Initiator wird zum Beispiel für die kationische Homo- oder Copolymerisation von Trioxan eingesetzt und erlaubt eine stabile und flexible Prozessführung der Polymerisation.

Process for separating organometallic compounds and/or metal carbonyls from their solutions in organic media

The separation of organometallic compounds and/or metal carbonyls from their solutions in organic media is effected according to the invention with the aid of semipermeable membranes of an aromatic polyamide.

Process for preparing sulphurous polymers

Initiator

Ein Initiator zur kationischen Polymerisation enthält neben einer Protonensäure zusätzlich auch ein Salz einer Protonensäure. Das molare Verhältnis von Protonensäure zu Salz liegt im Bereich von 1 : 0,01 bis 1 : 2.000. Der erfindungsgemäße Initiator wird zum Beispiel für die kationische Homo- oder Copolymerisation von Trioxan eingesetzt und erlaubt eine stabile und flexible Prozessführung der Polymerisation.

MACROPOROES, ASYMMETRIC HYDROPHIL MEMBRANE OF POLYARAMIDE

The membrane is characterised in that it contains a copolyamide having at least the following recurring structural units: (A) -OC-Ar-CO- (B) -NH-Ar'-NH- <IMAGE> in which Ar and Ar' are divalent aromatic radicals, in which the valence bonds are in the para or a comparable coaxial or parallel position, R is a lower alkyl radical or a lower alkoxy radical each having up to 4 C atoms or a halogen radical and R' is an unsubstituted or substituted methylene radical or an -O-Ar-O- group, in which Ar has the same composition as described above,

Method for the production of trioxane

The invention relates to a method for producing trioxane from aqueous formaldehyde solutions in the presence of acid catalysts. The formaldehyde is reacted into trioxane in a reaction column comprising a circulating evaporator. The formaldehyde solution used as an initial solution is mixed with a lateral flow from the bottom of the reaction column and is fed to the top portion of the reaction column via a tubular reactor. The inventive method is characterized by the fact that it requires little energy and forms a small amount of secondary product.

METHOD AND DEVICE FOR SEPARATING SOLIDS FROM POLYMER SOLUTIONS

Process for producing a cyclic acetal

The present invention relates to a process for producing cyclic acetal comprising i) preparing a reaction mixture comprising a) a formaldehyde source in a liquid medium and b) a catalyst; ii) converting the formaldehyde source into cyclic acetals, wherein the final conversion of said formaldehyde source to said cyclic acetal is greater than 10% on basis of the initial formaldehyde source.

Gasifier for a solid carbon fuel

Gazéifieur de combustible solide carboné comportant au moins une première cuve verticale (4) et des moyens d'introduction (5) pour introduire le combustible (2) dans une partie supérieure de la première cuve au dessus d'une zone de pyrolyse (10), ladite zone de pyrolyse étant une zone où le combustible introduit est pyrolysé pour produire des gaz de pyrolyse et du combustible carbonisé. Le gazéifieur comporte également une zone de combustion (20) pour brûler lesdits gaz de pyrolyse, une zone de réduction (30) pour gazéifier le combustible carbonisé provenant de la zone de pyrolyse (10) afin de produire des gaz de synthèse et des cendres, et une sortie (6) pour récolter lesdits gaz de synthèse. La première cuve (4) comporte un plateau horizontal fixe (50) monté entre le moyens d'introduction (5) et la zone de pyrolyse (10) afin d'y retenir le combustible introduit, ainsi qu'un poussoir mobile (51) monté entre les moyens d'introduction (5) et le plateau (50) pour transférer le combustible, retenu sur le plateau, vers la zone de pyrolyse (10). Le plateau (50) forme un écran thermique protégeant au moins partiellement les moyens d'introduction (5) et le poussoir mobile (51) contre les hautes températures régnant dans la première cuve (4). Carbonaceous solid fuel gasifier comprising at least a first vertical vessel (4) and introduction means (5) for introducing the fuel (2) into an upper part of the first vessel above a pyrolysis zone (10) said pyrolysis zone being an area where the fuel introduced is pyrolyzed to produce pyrolysis gases and carbonized fuel. The gasifier also has a combustion zone (20) for burning said pyrolysis gas, a reduction zone (30) for gasifying the carbonized fuel from the pyrolysis zone (10) to produce synthesis gases and ashes, and an outlet (6) for harvesting said synthesis gases. The first tank (4) comprises a fixed horizontal plate (50) mounted between the introduction means (5) and the pyrolysis zone (10) in ...

MACROPOROES, ASYMMETRIC HYDROPHIL MEMBRANE OF POLYARAMIDE

Macroporous, asymmetric, hydrophilic polyaramide membranes

Abstract of the Disclosure A macroporous, asymmetric, hydrophilic membrane containing polyaramid is described. The characterizing features are that it contains a copolyamide which has at least the following recurring structural units: (A) -OC-Ar-CO-(B) -NH-Ar'-NH (C) (D)

MACROPOROES, ASYMMETRIC, HYDROPHIL MEMBRANE OF POLYARAMIDE.

The membrane is characterised in that it contains a copolyamide having at least the following recurring structural units: (A) -OC-Ar-CO- (B) -NH-Ar'-NH- <IMAGE> in which Ar and Ar' are divalent aromatic radicals, in which the valence bonds are in the para or a comparable coaxial or parallel position, R is a lower alkyl radical or a lower alkoxy radical each having up to 4 C atoms or a halogen radical and R' is an unsubstituted or substituted methylene radical or an -O-Ar-O- group, in which Ar has the same composition as described above,

METHOD FOR PRODUCING SULFURIZED POLYMERS

Process for the preparation of aromatic sulfur-containing polymers

Device for separating fluid from a fiber following contact

A device for separating a moving fiber from processing fluid is disclosed and claimed. A chamber defining hydrophilic and hydrophobic flow paths respectively is exemplified. The device is placed so that substantially all water associated with processing exits via the hydrophilic path while the fiber exits via the hydrophobic path.

Monoanhydride compounds, method of making same and reaction products thereof

The present invention relates to monoanhydride monomer compounds, methods of making such compounds and reaction products of the monoanhydride-diacid compounds with other monomers. The inventive monomer compounds exhibit selective reactivity, that is, the dianhydride locus is substantially more reactive towards amines than the diacid locus making it possible to sequentially synthesize a new class of materials suitable for membranes, catalytic substrates or any speciality material required for advanced applications.

Composite diaphragm, process for producing it and its use

Abstract of the disclosure HOE 89/F 406K Composite membrane, process for its production and its use A composite membrane for gas separation having a three-layer structure, constructed from A) a supporting membrane layer made of porous polymer, B) a nonporous, gas-permeable intermediate layer, C) a permselective layer of regularly arranged organic molecules having a layer thickness of 3 to 100 nm, the layers (A) and (C) enclosinq the intermediate layer (B), wherein the permselective layer (C) is constructed from regularly arranged amphiphilic molecules which contain one or two alkyl chains each having 7 to 25 carbon atoms per polar hydrophilic group.

Process for separating organometallic compounds and/or metal carbonyls from their solutions in organic media

Organometallic compounds and/or metal carbonyls are separated from their solutions in organic media with the aid of semi-permeable membranes made of aromatic polyamides.

Initiator

An initiator for cationic polymerization comprises a salt of a protic acid as well as a protic add. The molar ratio of protic acid to salt is in the range from 1:0.01 to 1:2000. The initiator is used for example for cationic homo- or copolymerization of trioxane, and permits stable and flexible operation of the polymerization.

Semipermeable membrane made from a homogeneously miscible polymer blend

A semipermeable membrane is described which comprises a homogeneously miscible polymer blend of an aromatic polyamide and polyvinylpyrrolidone. The aromatic polyamide is in particular formed of recurrent units of the formula I: ##STR1## wherein E 1 and E 2 are identical or different and are selected from the groupings ##STR2## --AR 1 --, and --AR 1 --X--AR 2 , where AR 1 and Ar 2 are the same or different 1,2-phenylene, 1,3-phenylene or 1,4-phenylene groups which may be substituted by (C 1 -C 6 )-alkyl, (C 1 -C 6 )-alkoxy, --CF 3 or halogen and X denotes a) a direct bond or one of the following divalent groups: --O--, --C(CF 3 ) 2 --, --SO 2 --, --C(R 1 ) 2 --, with R 1 being hydrogen, (C 1 -C 6 )-alkyl or fluoroalkyl having from 1 to 4 carbon atoms in the alkyl group or --Z--AR 1 --Z--, where Z is one of the groups --O-- and --C(CH 3 ) 2 or --O--Ar 1 --Y--Ar 2 --O--, where Y has the meaning given under Xa) above. The membrane has pronouned hydrophilic properties and is moreover stable to hydrolyzing agents and oxidants and to the action of heat. It is also resistant to organic solvents and microorganisms and exhibits low adsorption of proteins. A process for producing the membrane and a process for modifying the retention capacity thereof are also described. The membrane is produced by spreading a solution of the homogeneously miscible polymer blend on a planar substrate and precipitating the blend. Retention capacity is modified by heat treatment.

MACROPOROUS, ASYMMETRIC AND HYDROPHILIC POLY-V-ARAMIDE MEMBRANES.

The membrane is characterised in that it contains a copolyamide having at least the following recurring structural units: (A) -OC-Ar-CO- (B) -NH-Ar'-NH- <IMAGE> in which Ar and Ar' are divalent aromatic radicals, in which the valence bonds are in the para or a comparable coaxial or parallel position, R is a lower alkyl radical or a lower alkoxy radical each having up to 4 C atoms or a halogen radical and R' is an unsubstituted or substituted methylene radical or an -O-Ar-O- group, in which Ar has the same composition as described above,

SEMIPERMEABLE MEMBRANE OF A HOMOGENE MIXABLE POLYMER ALLOY.

A semipermeable membrane is described which comprises a homogeneously miscible polymer blend of an aromatic polyamide and polyvinylpyrrolidone. The aromatic polyamide is in particular formed of recurrent units of the formula I: <IMAGE> (I) wherein E1 and E2 are identical or different and are selected from the groupings <IMAGE> <IMAGE> -AR1-, and -AR1-X-AR2, where AR1 and Ar2 are the same or different 1,2-phenylene, 1,3-phenylene or 1,4-phenylene groups which may be substituted by (C1-C6)-alkyl, (C1-C6)-alkoxy, -CF3 or halogen and X denotes a) a direct bond or one of the following divalent groups: -O-, -C(CF3)2-, -SO2-, -C(R1)2-, with R1 being hydrogen, (C1-C6)-alkyl or fluoroalkyl having from 1 to 4 carbon atoms in the alkyl group or -Z-AR1-Z-, where Z is one of the groups -O- and -C(CH3)2 or -O-Ar1-Y-Ar2-O-, where Y has the meaning given under Xa) above. The membrane has pronouned hydrophilic properties and is moreover stable to hydrolyzing agents and oxidants and to the action of heat. It is also resistant to organic solvents and microorganisms and exhibits low adsorption of proteins. A process for producing the membrane and a process for modifying the retention capacity thereof are also described. The membrane is produced by spreading a solution of the homogeneously miscible polymer blend on a planar substrate and precipitating the blend. Retention capacity is modified by heat treatment.

Macroporous, asymmetric, hydrophilic polyamide membranes

The membrane is characterised in that it contains a copolyamide having at least the following recurring structural units: (A) -OC-Ar-CO- (B) -NH-Ar'-NH- <IMAGE> in which Ar and Ar' are divalent aromatic radicals, in which the valence bonds are in the para or a comparable coaxial or parallel position, R is a lower alkyl radical or a lower alkoxy radical each having up to 4 C atoms or a halogen radical and R' is an unsubstituted or substituted methylene radical or an -O-Ar-O- group, in which Ar has the same composition as described above,

Odorants for gases

The invention relates to an odorant for city gas, containing norbornene or a norbornene derivative, a thinner and optionally additional additives. The inventive odorant is characterised in that it is sulphurless and has a low toxicity and that only a negligible amount is absorbed by the soil. The odorant releases a distinct warning odour, even in low concentrations.

Process for the preparation of polyarylene sulfides

Semipermeable membrane made from a homogeneously miscible polymer blend

A semipermeable membrane is described which comprises a homogeneously miscible polymer blend of an aromatic polyamide and polyvinylpyrrolidone. The aromatic polyamide is in particular formed of recurrent units of the formula I: (see formula I) wherein E1 and E2 are identical or different and are selected from the groupings (see formula II) -Ar1-, and -Ar1-X-Ar2, where Ar1 and Ar2 are the same or different 1,2-phenylene, 1,3-phenylene or 1,4-phenylene groups which may be substituted by (C1-C6) -alkyl , (C1-C6)-alkoxy, -CF3 or halogen and X denotes a) a direct bond or one of the following divalent groups -O-, -C (CF3)2-, -SO2-, -CO-, -C(R1)2-, with R2 being hydrogen, (C1-C6)-alkyl or fluoroalkyl having from 1 to 4 carbon atoms in the alkyl group or b) -Z-Ar1-Z-, where Z is one of the groups -O- and -C(CH3)2 or c) -O-Ar1-Y-Ar2-O-, where Y has the meaning given under Xa) above. The membrane has pronounced hydrophilic properties and is moreover stable to hydrolyzing agents and oxidants and to the action of heat. It is also resistant to organic solvents and microorganisms and exhibits low adsorption of proteins. A process for producing the membrane and a process for modifying the retention capacity thereof are also described. The membrane is produced by spreading a solution of the homogeneously miscible polymer blend on a planar substrate and precipitating the blend. Retention capacity is modified by heat treatment.

Process for the preparation of sulphur-containing polymers

Bei dem Verfahren zur Herstellung von aromatischen schwefelhaltigen Polymeren wird das Polymer aus einem Präpolymer mit Halogen-Endgruppen gebildet. Das Verfahren kann in zwei Stufen erfolgen: 1. Herstellung des Präpolymeren und 2. Umsetzung von Präpolymer zum Polymer. Das Verfahren eignet sich besonders zur Herstellung von Polyphenylensulfid. In the process for the production of aromatic sulfur-containing Polymers is the polymer of a prepolymer with halogen end groups educated. The process can be carried out in two stages: 1. Production of the Prepolymers and 2. conversion of prepolymer to polymer. The procedure is particularly suitable for the production of polyphenylene sulfide.

Process for preparation of oxymethylene polymers in a homogeneous phase, and use

A process and an apparatus are described for preparation of oxymethylene polymers. This process encompasses polymerization, in a homogeneous phase, of a monomer which forms oxymethylene groups, as far as 90% of maximum conversion in the presence of an acetal of formaldehyde and of an initiator for cationic polymerization, followed by deactivation of the reaction mixture. The resultant oxymethylene polymers have alkyl ether end groups and are extremely stable.

Semi-permeable membrane made of an homogeneously mixed polymeric alloy

A semipermeable membrane is described which comprises a homogeneously miscible polymer blend of an aromatic polyamide and polyvinylpyrrolidone. The aromatic polyamide is in particular formed of recurrent units of the formula I: <IMAGE> (I) wherein E1 and E2 are identical or different and are selected from the groupings <IMAGE> <IMAGE> -AR1-, and -AR1-X-AR2, where AR1 and Ar2 are the same or different 1,2-phenylene, 1,3-phenylene or 1,4-phenylene groups which may be substituted by (C1-C6)-alkyl, (C1-C6)-alkoxy, -CF3 or halogen and X denotes a) a direct bond or one of the following divalent groups: -O-, -C(CF3)2-, -SO2-, -C(R1)2-, with R1 being hydrogen, (C1-C6)-alkyl or fluoroalkyl having from 1 to 4 carbon atoms in the alkyl group or -Z-AR1-Z-, where Z is one of the groups -O- and -C(CH3)2 or -O-Ar1-Y-Ar2-O-, where Y has the meaning given under Xa) above. The membrane has pronouned hydrophilic properties and is moreover stable to hydrolyzing agents and oxidants and to the action of heat. It is also resistant to organic solvents and microorganisms and exhibits low adsorption of proteins. A process for producing the membrane and a process for modifying the retention capacity thereof are also described. The membrane is produced by spreading a solution of the homogeneously miscible polymer blend on a planar substrate and precipitating the blend. Retention capacity is modified by heat treatment.

initiator

Ein Initiator zur kationischen Polymerisation enthält neben einer Protonensäure zusätzlich auch ein Salz einer Protonensäure. Das molare Verhältnis von Protonensäure zu Salz liegt im Bereich von 1 : 0,01 bis 1 : 2000. Der erfindungsgemäße Initiator wird zum Beispiel für die kationische Homo- oder Copolymerisation von Trioxan eingesetzt und erlaubt eine stabile und flexible Prozessführung der Polymerisation. In addition to a protic acid, an initiator for cationic polymerization additionally contains a salt of a protic acid. The molar ratio of protic acid to salt is in the range from 1: 0.01 to 1: 2000. The initiator according to the invention is used, for example, for the cationic homo- or copolymerization of trioxane and permits stable and flexible process control of the polymerization.

Copolymer for compatibilizing blends

A copolymer comprising a) a segment A with a number-average molar mass Mn of from 1000 to 20,000 g/mol, which has i) units 1, which have been derived from structures of the formula (I) ##STR1## where the radicals R 1 and R 2 , independently of one another, are a hydrogen, fluorine, chlorine or bromine atom or a branched or unbranched alkyl or alkoxy radical having from 1 to 6 carbon atoms; and/or ii) units 2, which are derived from structures of the formula (II) ##STR2## and b) a segment B, derived from a polyarylene sulfide structure of the formula (IV) ##STR3## where Ar is an aromatic radical, or more than one condensed aromatic radicals, and n is a number from 2 to 100, in particular from 5 to 20, together with a process for its preparation, and also its use for compatibilizing blends made from polyarylene sulfides and aromatic polyesters.

Alloys with a glass transition temperature

Polymerlegierungen auf der Basis von Polybenzimidazolen sind aufgrund ihrer außergewöhnlichen thermischen und mechanischen Eigenschaften in der Technik von großem Interesse. Legierungen aus einem Homo- oder Copolybenzimidazol und Poly-H-vinylpyrrolidon sind homogen gemischt und weisen nur eine Glastemperatur auf. Polymer alloys based on polybenzimidazoles are of great interest in technology due to their exceptional thermal and mechanical properties. Alloys from a homo- or copolybenzimidazole and poly-H-vinylpyrrolidone are mixed homogeneously and have only a glass transition temperature.

Method and device for separating substances

The invention relates to a method of separating substances according to which a substance containing at least a first and a second component are introduced, together with a wash fluid, into a container having at least one settling chamber and subjected to a gravitation field. Under the effect of the gravitation field the first substance component is concentrated in the settling chamber in a settling zone which is limited by a base. Next the substance containing said concentrated first component is evacuated from the settling zone through an opening in the base in the form of a sediment layer. The wash fluid flows against the sediment layer from the side and then passes through said sediment layer such that the remaining second component is at least partly displaced from the sediment layer. The invention also relates to a device, notably for carrying out the above method.

Process for the Preparation of Oxymethylene Polymers and Apparatus Suitable for This Purpose

A process and an apparatus for the preparation of oxymethylene polymers is described. The process encompasses the polymerization of a monomer that forms oxymethylene groups, if appropriate in the presence of a cyclic acetal, together with an acetal of formaldehyde and with an initiator for cationic polymerization, preferably in a gas-tight kneader or extruder. The temperature profile of the polymerization here is designed in such a way that the polymerization mixture, which is initially heterogeneous by virtue of precipitating polymer, is converted to a homogeneous phase at the end of the polymerization. The homogeneous phase in which the polymer is present in liquid form is stabilized via addition of deactivators. After removal of volatile constituents, oxymethylene polymers are obtained with high thermal stability and with good mechanical properties. The oxymethylene polymers can be prepared at low energy cost and their properties can be adjusted as desired via prescription of the temperature profile during the polymerization.

Process for Separating Organometallic Compounds and/or Metal Carbonyls from Their Solutions in Organic Media

The separation of organometallic compounds and/or metal carbonyls from their solutions in organic media is effected according to the invention with the aid of semipermeable membranes of an aromatic polyamide.

Method for the production of trioxane

The invention relates to a process for preparing trioxane from aqueous formaldehyde solutions in the presence of acidic catalysts. The reaction of the formaldehyde to give trioxane takes place in a reaction column equipped with a circulation evaporator, and the formaldehyde solution used as the starting solution is mixed with a sidestream from the bottom of the reaction column and fed to the upper section of the reaction column via a tubular reactor. The process is notable for a low energy requirement and little by-product formation.

Homogeneously mixed alloys comprising aromatic polyamides and poly-n-vinylpyrrolidone, process for their preparation, and their use

Vorrichtung und verfahren zur stofftrennung

Verfahren zur kombinatorischen herstellung von mischungen sowie seine verwendung

Initiator

Ylide-pyridinium-polymeren und daraus hergestellte materialien.

Verfahren zur herstellung von trioxan

Method for producing and dehydrating cyclic formals

Processes are described which comprise: (a) providing a mixture comprising a cyclic formal and water, wherein the mixture has a cyclic formal concentration and a water concentration; (b) bringing the mixture into contact with an aqueously selective membrane; (c) creating a pressure differential across the membrane; and (d) obtaining a permeate having a higher water concentration and a lower cyclic formal concentration than the mixture, and a retentate having a lower water concentration and a higher cyclic formal concentration than the mixture.

Legierungen mit einer Glastemperatur

Process and apparatus for preparing formaldehyde from methanol by dehydrogenation

Optical indicator element

An optical indicator element includes a locator and function symbol that is equipped with a shared optical indicator element, with the intensity of the shared light input being adapted and regulated in brightness to the current ambient brightness. Regulation is accomplished through a PWM (pulse-width modulated) signal from a control device. The indicator element itself comprises a shared and preferably colored plastic that illuminates the locator and function symbol, with the area of the joint symbol being cleared of colored paint on the plastic. The light is preferably guided from at least one light source to the plastic by a light conductor into which the light is coupled, but this can also be accomplished by at least one light source located directly beneath the plastic.

Vorrichtung und verfahren zur stofftrennung

Die Erfindung betrifft eine Vorrichtung zur Stofftrennung mittels Gegenstromwaschung einem Behälter mit einem ersten Endbereich, an welchem eine erste Eintrittsöffnung für den Eintritt eines Stoffgemisches und eine erste Austriffsöffnung für den Austritt einer abzutrennenden Stoffkomponente des Stoffgemischs und eines Waschfluids vorgesehen ist, mit einem dem ersten Endbereich axial gegenüberliegenden zweiten Endbereich, an welchem eine zweite Eintrittsöffnung für den Eintritt des Waschfluids und eine zweite Austrittsöffnung für den Austritt einer weiteren Stoffkomponente des Stoffgemischs und des Waschfluids vorgesehen ist, sowie mit einem Verdrängungsbereich, welcher zwischen dem ersten Endbereich und dem zweiten Endbereich vorgesehen ist, wobei der Verdrängungsbereich in den zweiten Endbereich mit einem Übergangsquerschnitt übergeht. Die Vorrichtung ist erfindungsgemäß dadurch gekennzeichnet, dass im Bereich des Übergangsquerchnitts für ein flächiges Einleiten des Waschfluids eine Eintragseinrichtung angeordnet ist, welche mit der zweiten Eintrittsöffnung leitend verbunden ist, und dass zur gezielten Einbringung von Bewegungsenergie in den Verdrängungsbereich mindestens ein Bewegungsorgan vorgesehen ist. Ferner betrifft die Erfindung ein Verfahren zur Stofftrennung durch Waschung mit einem Waschfluid.

Vorrichtung und verfahren zur stofftrennung

Die Erfindung betrifft eine Vorrichtung zur Stofftrennung mittels Gegenstromwaschung einem Behälter mit einem ersten Endbereich, an welchem eine erste Eintrittsöffnung für den Eintritt eines Stoffgemisches und eine erste Austriffsöffnung für den Austritt einer abzutrennenden Stoffkomponente des Stoffgemischs und eines Waschfluids vorgesehen ist, mit einem dem ersten Endbereich axial gegenüberliegenden zweiten Endbereich, an welchem eine zweite Eintrittsöffnung für den Eintritt des Waschfluids und eine zweite Austrittsöffnung für den Austritt einer weiteren Stoffkomponente des Stoffgemischs und des Waschfluids vorgesehen ist, sowie mit einem Verdrängungsbereich, welcher zwischen dem ersten Endbereich und dem zweiten Endbereich vorgesehen ist, wobei der Verdrängungsbereich in den zweiten Endbereich mit einem Übergangsquerschnitt übergeht. Die Vorrichtung ist erfindungsgemäss dadurch gekennzeichnet, dass im Bereich des Übergangsquerchnitts für ein flächiges Einleiten des Waschfluids eine Eintragseinrichtung angeordnet ist, welche mit der zweiten Eintrittsöffnung leitend verbunden ist, und dass zur gezielten Einbringung von Bewegungsenergie in den Verdrängungsbereich mindestens ein Bewegungsorgan vorgesehen ist. Ferner betrifft die Erfindung ein Verfahren zur Stofftrennung durch Waschung mit einem Waschfluid.

Vorrichtung und verfahren zur stofftrennung

Vorrichtung und verfahren zur stofftrennung

Die Erfindung betrifft eine Vorrichtung zur Stofftrennung mittels Gegenstromwaschung einem Behälter mit einem ersten Endbereich, an welchem eine erste Eintrittsöffnung für den Eintritt eines Stoffgemisches und eine erste Austriffsöffnung für den Austritt einer abzutrennenden Stoffkomponente des Stoffgemischs und eines Waschfluids vorgesehen ist, mit einem dem ersten Endbereich axial gegenüberliegenden zweiten Endbereich, an welchem eine zweite Eintrittsöffnung für den Eintritt des Waschfluids und eine zweite Austrittsöffnung für den Austritt einer weiteren Stoffkomponente des Stoffgemischs und des Waschfluids vorgesehen ist, sowie mit einem Verdrängungsbereich, welcher zwischen dem ersten Endbereich und dem zweiten Endbereich vorgesehen ist, wobei der Verdrängungsbereich in den zweiten Endbereich mit einem Übergangsquerschnitt übergeht. Die Vorrichtung ist erfindungsgemäß dadurch gekennzeichnet, dass im Bereich des Übergangsquerchnitts für ein flächiges Einleiten des Waschfluids eine Eintragseinrichtung angeordnet ist, welche mit der zweiten Eintrittsöffnung leitend verbunden ist, und dass zur gezielten Einbringung von Bewegungsenergie in den Verdrängungsbereich mindestens ein Bewegungsorgan vorgesehen ist. Ferner betrifft die Erfindung ein Verfahren zur Stofftrennung durch Waschung mit einem Waschfluid.

Vorrichtung und verfahren zur stofftrennung

Polymers having pendent pyridinium ylide moieties and products prepared therefrom

Polymeric pyridinium ylide and products derived therefrom

Verfahren zur nicht oxidativen herstellung von formaldehyd aus methanol