[UNK]

the present invention relates to an improved method for ' the production of polyesters highly polymerized. More particularly, the invention relates to a method, for the production of polyesters, characterized in that it consists essentially in firstly producing a bis (m-hydroxy alkyl) by using an ester exchange reaction between an ester of lower [...] of an aromatic dicarboxylic acid and glycols in using as catalyst a manganese compound is soluble in the reaction system, and adding thereto a phosphoric acid, phosphorous acid, hypophosphorous acid or a phosphorus compound, in particular a trivalent phosphorus compound capable of being converted into any of the phosphorus derivatives to deactivate polymerization catalysts that are the compounds of [...], with a concentration of the glycols in the reaction system set so as to decrease to a value between 1 and 30^by weight (hereinafter, all percentages are intended to be taken as being expressed by weight), is carried out by loading a polycondensation germanium dioxide in the form specified amorphous germanium dioxide, a hydrate, a solution in an aqueous glycol or a product-dioxide cooled germanium from a melt dioxdie with boron or antimony trioxide.

To produce polyesters, a conventional method well known and frequently used consists in producing an ester exchange reaction between an ester of a diacid [...] and a lower alkylene glycol in the presence of a catalyst which is a compound of soluble manganese, and, immediately after the end of the reaction, to carry out polycondensation reaction product in the presence of a catalyst at a pressure high temperature [...] during the polycondensation, the reaction is carried out generally at a temperature above 200° 0. In these conditions, various side reactions tend to occur, and therefore the resulting polyesters are exposed to degradation of some physical property, in particular, of coloring, to a lower point of fusion, [...] more, the catalyst remaining in the polyesters, i.e. the existence of a mineral metallic compound, imparts a tint (due to the ion of the metal content therein) to a shaped article prepared from such [...] such coloring can not be removed by ordinary methods of bleaching. In particular, when using such polyesters' in the field of textile products, such a coloring is a defect [...]. In the case where the polyesters are used in the field of thin films and like, a degradation of the transparency caused by the mineral material therein preventing the development of uses of the kind of product.

During studies have resulted in the present invention, it is found that the polyester obtained by carrying out the known method described above is lower in its whiteness, to its thermal stability and the possibility of bleaching*

An object of the present invention is therefore to provide a method for the production of polyesters having excellent in whiteness, thermal stability, possibility of bleaching, and which is free of a melting point depressant.

According to the present invention, the reaction is carried out ester exchange in a manner well known, the reaction is usually in the pressure line [...] the compounds of manganese useful as catalyst in the ester exchange reaction include, in addition to the manganese carbonate, salts of an aliphatic acid (acetic acid, propionic, butyric or the like), salts of an aromatic acid (benzoic acid, p-methyl-benzoic, naphthoic and the like) and a j an alkoxide [...] such as methyl, ethyl, propyl and the like, the compounds of the phosphorus to be added for deactivating the polymerization catalyst substantially that constitutes said manganese compound can be selected from phosphoric acid, phosphorous acid, hypophosphoric acid, an alkali metal salt, alkaline earth metal or ammonium of said acids, and more particularly to a trivalent phosphorus compound. Phosphorus compounds particularly useful are phosphorous acid, triphenyl phosphite and tricresylphosphite-

the addition of a phosphorus compound is to be performed after the end of the ester exchange reaction and prior to the start of the polycondensation. the proportion of phosphorus compound to be added varies according to the proportion used compound [...] for implementing the invention, it is necessary to add phosphorus compounds in a proportion such that the result is a complete [...] of the catalyst consisting of manganese compound used, the gathered data in Table 1 below illustrate this purpose; they relate to an operation in utilizing parts 194 dimethyl terephthalate, 160 e. ethylene glycol and 0.04 pd ' manganese acetate for the ester exchange reaction and, after the end of said ester exchange reaction and the addition of phosphorus compound, the reaction product is subjected to a polycondensation reaction at a temperature of 280° 0 and under a pressure of 0.1 mm of mercury.

Table 1. -Effect deactivation of the manganese compound

on the bleaching polimerizability and-

Phosphite Viscosity Ratio Guests

triphenyl to reached after a

manganese acetate polymerization

in mol % during 5 hours

Color sealable polymer after bleaching*

Bleaching * Measurement conditions: bleached 60 minutes to 90 °C in

an aqueous solution of [...] (2 g) and acetic acid

(2 g) in a liter of water, and then reduced with an aqueous solution of sodium hydrosulfite (1 g) and sodium hydroxide (1 g) [...] a liter of water during 30 minutes to 90 °C.

** [...] with the addition of 0.02 portion amorphous germanium dioxide after loading of the phosphorus compound.

In the examination of the above data, it is found that the catalytic activity [...] of the manganese compound is substantially cancelled by adding a proportion of phosphorus compound is, mol, more than about 2 times, and preferably 2.5 times, the amount of manganese compound, and that the properties of bleaching are remarkably improved at the same time.

It is confirmed also that the problem of discoloration of the polymer by the heat is significantly reduced by the deactivation of the manganese compound.

The proportion of phosphorus compound to be added in order to deactivate the manganese compound may exceed more than 10 times (mol) that of manganese compound, , but no further improvement is found.

The polymerization reaction of the ester exchange reaction product thus obtained is performed by adding catalytic proportion of germanium dioxide as a polymerization catalyst; in this case; a concentration of the glycol present in the reaction system is critical. In the catalytic system compound of phosphorus-dioxide [...] germanium, an etherification reaction tends to intervene with the result a coloration of the polyester obtained. To avoid such a coloring, it is necessary to suppress as much as possible the proportion of the glycols in the system at the time of the addition of the germanium dioxide. [...][...][...] understood, the degree of such a decrease is in relation to the reaction conditions (temperature and time) [...] systematic trials show that the proportion of glycols should preferably be between 1 and 30 fa fa by weight-

Herein is the ester exchange reaction between dimethyl terephthalate and ethylene glycol using 0.02 fa a manganese compound as a catalyst. At resulting reaction product, is added 0.1 fa of phosphorous acid, and in the polycondensation by adding 0.02 dioxide and fa germanium Heating to 280 °C during 3 hours. On lowering of the melting point of the polymer due to a side reaction is illustrated by the following expression:

^ 0.5^{2+5 (Ce/100) Aim}

where Ce is the concentration of glycol {fa by weight) at the time of the addition of the germanium dioxide, and Tm is measured using a differential calorimeter at a maximum position wherein crystals of the ' polymer dissolve. The expression indicates that the higher a concentration of glycol in the system is small, the resulting polymer becomes more excellent.

Can control the glycol content by performing a step of heating the reaction system at a temperature above the boiling point of the glycol under reduced pressure or under atmospheric pressure for expelling of the glycol by distillation.

the reaction product, ester exchange thus obtained is then polymerized to using germanium dioxide in a form specified.

It has been found that germanium dioxide in some form can be considerably improved with solubility in both the polycondensation system and in ethylene [...] ;

eet also favorable effect, its activity of polycondensation is greater _AOE280A2AO>

Among the germanium thiophenylthiopyrane in a form specified in accordance with the present invention include amorphous germanium dioxide, a hydrate, an aqueous solution and a solution in aqueous ethylene glycol, and a product prepared by melting germanium dioxide with boron trioxide or antimony trioxide and cooling of the melt, preferably quickly*

A amorphous germanium dioxide exhibits a catalytic activity of polycondensation much higher than that of a germanium dioxide currently commercially sold. related germanium thiophenylthiopyrane presented in the form of a hydrate, an aqueous solution or a solution in 1' aqueous ethylene [...] also have a catalytic activity of polycondensation much larger than that of a germanium dioxide of commerce or a germanium [...].

In an aqueous system, germanium dioxide does not react with ethylene glycol but dissolves as such, and then germanium dioxide dissolved activity has a much greater than that of a reaction product of germanium dioxide with ethylene glycol, reaction product such as, for example, the germanium glycoxide.

Products prepared by melting dioxdie germanium with boron trioxide or antimony trioxide and by cooling the melt, preferably rapidly, not only have much greater activity as polycondensation catalysts: they also improve remarkably the whiteness and the light transmittance of the polymer type products, when compared to the results obtained using a germanium dioxide commonly sold commercially. To prepare such products, is preferably used a weight ratio of germanium dioxide at boron trioxide or antimony trioxide between 100:1 and 1:20.

the germanium thiophenylthiopyrane in the form specified according to the present invention exhibit an effect as a polycondensation catalyst at very low concentrations; the concentration to provide the same catalytic effect than that of the antimony trioxide to be used on an industrial scale is about 0.01, at most 0.02 i < >, calculated on the base of the terephthalic acid or its esters-

the polycondensation is carried out at high temperature and under a reduced pressure, according to the conventional technique well known.

the present invention is applicable in a large domain of the production of polyesters, , i.e. that it is applicable to the production of a polyester by ester exchange reaction between a lower alkyl ester of an aromatic dicarboxylic acid represented by the following general formula (A) and ~ glycols represented by the following general formula (B), and then-by polycondensation of the product resulting from said ester exchange reaction.

^, 000R [...]_{4 2 X ^} _AOE280A2AO> _AOE280A2AO> _AOE280A2AO> (A)

wherein j and R. R. ^ each represent an alkyl radical comprising 1 to 10 atoms " carbon; fi.'_{2 and} are each ^ - ^ ( [...] ) where n is either equal to zero, is an integer of 1 to 4 inclusive; X is a divalent aromatic radical corresponding to the formula

<

7 wherein T is a divalent residue corresponding

the formula-^ (0¾),_{n-(0:00 2) -00}-(0:00_2)n-, -(CH_2)n- 0 - (CH_2)n-,

- 0 - (^ [...] -0-, <-O-- -0° - 3 - (0:00_{2) ji-S-},

S-^ - ^-S-, well- [...] = N-(GH_2)n- CH 2 where n is zero or

an integer from 1 to 4 inclusive and m represents an integer of 1 to 5 inclusive.

[...] -0 - ( [...],)-OR, or 5,2^P6... (B) Hg-O- [...] - [...] ^

where p is a number from 2 to 12 inclusive; q is a number from 1 to 10 inclusive; and R ^ Rg each represent a hydrogen atom or an acyl group containing 2 to 4 carbon atoms, and Ry represents an alkylene radical having 2 to 4 carbon atoms.

In the practice of the present invention, it is also possible to produce polyesters using a mixed system comprising an ester of aliphatic dicarboxylic acid, for example dimethyl adipate and dimethyl succinate, and said aromatic dicarboxylic acid ester, glycol further.

Oi following examples are given different, non-limi-course

_AOE296A0AO> [...], for more fully illustrate the present invention.

In Example 1 a. reaction vessel, is loaded 194 parts by weight (hereinafter, all amounts thus specified are intended to be taken by weight, and "part" is abbreviated "e.") dimethyl terephthalate, 160 e. ethylene glycol and 0.04 [...] p. of manganese as a catalyst, and is carried the ester exchange reaction to 200° 0 during 3 hours to distilling a stoichiometric ratio of methanol. The system resulting reaction is heated to 250 °C for distilling ethylene glycol present, in the system to control the proportion of ethylene glycol and the lower to 12 thereafter adding 0.1 p. of phosphorous acid to deactivate the manganese acetate having been used as a catalyst.

Furthermore, is added to the reaction system e. 0.02 germanium dioxide in the form of an aqueous solution, the temperature is raised to 280° G, and the polycondensation is carried out under a reduced pressure of Q, 08 mm Hg for three hours.

The resulting polymer has a melting point (P. S '.) of 2b5°C and a reduced viscosity of 0.78. (The value of the reduced viscosity is measured to 35 °C using as the solvent a mixture of phenol and tetrachloroethane in a weight ratio of 1:2 and wherein the polymer is dissolved at a concentration of 0.2 g/100 ml. Thereafter, all values of viscosity Guests claims are intended to be taken as having been measured in the state specified)" The whiteness, transparency and excellent spinnability of the polymer are*

Example 2. -In a reaction vessel, 194 is charged e. dimethyl terephthalate, 160 e. ethylene glycol and 0.04 p. glycolate manganese, and in the exchange reaction d^{! ester} 200 °C during 3 hours to flush a stoichiometric ratio of methanol, is then added 0.1 p. of hypophosphorous acid to disable the glycolate manganese have been used as polymerization catalyst.

The resulting reaction system is heated up to 250 °C, is added 0.03 p. carbohydrate germanium dioxide after adjusting the proportion of ethylene glycolate present in the system, and the polymerization is carried out at 280 °C under a reduced pressure of 0.05 mm of mercury.

The relationship between the proportion of ethylene glycol in the system when. adding germanium dioxide and the melting point of the polymer obtained data spring of Table 2.

Table 2

Proportion ethylene glycol fusion point of the coexisting in a polymer system obtained

(# by weight) (°C)

Example 3 *-polymerization Oh conduit as in the example 1, but using 1' manganese hydroxide as catalyst front exchange instead of manganese acetate, and a solution in the glycol aqueous germanium dioxide as a polymerization catalyst _AOE280A2AO>

The polymer thus obtained has a viscosity a [...] Guests of 0.75 and^1. 265.5 °C of, whiteness and transparency is excellent, and it has good [...] -

[...] Example 4-is the ester exchange reaction and the polycondensation reaction both in the manner described in the example 1, but using manganese benzoate instead of manganese acetate, and the amorphous germanium dioxide in place of its hydrate. A polymer is obtained a whiteness and excellent transparency, and whose T.O.S. is 265° 0.

Example 5 _AOE280A2AO>-In a reaction vessel, is charged p 550.

ester 1,2-bis-^-carboxyphenoxy) [...], 160 e. ethylene glycol and 0.06 p. manganese carbonate, and the reaction is brought to 200 °C ester exchange during 4 hours for distilling ethylene glycol to lower to 15 # the proportion of ethylene glycol present in the system. P 0.4 is then added.

triphenyl phosphite to disable the manganese carbonate have been used as polymerization catalyst.

At resulting system, is added 0.02 p. of amorphous germanium dioxide, and then the temperature is raised to 280° G and the polymerization is conducted for 5 hours under a reduced pressure of 0.08 mm of mercury and the result is a polymer having a reduced viscosity of 0.81 and a P.P. of 250° G, and a whiteness and excellent transparency*

Example 6. -In a glass container, is placed e. 194 dimethyl terephthalate and 160 e. ethylene glycol, and the mixture is heated to 200 °C in the presence of 0.04 p. manganese acetate * about until the theoretical amount of methanol has been expelled by addition of 0.5 [...] p. of triphenyl phosphite to the reaction mixture, is raises the temperature to 280° G, is flushing of the ethylene glycol by distillation until to 11 $in the system, and the polycondensation is carried out in the presence of the catalyst specified (in an amount of 0.02 $) to 280° G and under a reduced pressure of 0.1 mm of mercury s_. the results are listed in table 3"

Table 5