手术臂

METHOD FOR PREPARING ISOPHORONE DIISOCYANATE

Disclosed is a method for preparing isophorone diisocyanate. The method comprises the following steps: (1) reacting isophorone with hydrogen cyanide in the presence of a catalyst to obtain isophorone nitrile; (2) reacting the isophorone nitrile obtained in step (1) with ammonia gas and hydrogen in the presence of a catalyst to obtain isophorone diamine; and (3) subjecting the isophorone diamine to a phosgenation reaction to obtain the isophorone diisocyanate, wherein the content of impurities containing a secondary amine group in the isophorone diamine that undergoes the phosgenation reaction in step (3) is ≤ 0.5 wt%, preferably ≤ 0.3 wt%, and further preferably ≤ 0.1 wt%. By means of the method of the present invention, the content of hydrolyzed chlorine in the isophorone diisocyanate product can be effectively reduced, the yellowing resistance of the product is effectively improved, and the harm of causing an unqualified downstream article due to the presence of the hydrolyzed chlorine ...

METHOD FOR PREPARING ISOCYANATE IN GASEOUS PHASE

Disclosed is a method for preparing an isocyanate in a gaseous phase, comprising feeding, in the presence or absence of an inert gas, an amine-containing gas stream and a phosgene-containing gas stream into a reaction region, allowing the amine and the phosgene to contact in gaseous forms and undergo a phosgenation reaction in the reaction region, thus preparing the target isocyanate in a gaseous form in the reaction region. The phosgene-containing stream is subjected to preheating and warming before being fed into the reaction region, and the phosgene-containing stream comprises a substance A at a mass fraction of < 1% before being subjected to the preheating and warming up, the substance A being a NCO group-containing substance and/or an olefinic double bond-containing substance. The method of the present invention can reduce the formation of clogging matter in a heat exchanger and a vessel during the preheating and warming of the phosgene and during the reaction process. Accordingly, ...

Methanol ammoxidation catalyst as well as preparation method and application thereof

The invention discloses a methanol ammoxidation catalyst as well as a preparation method and application thereof. The catalyst comprises the following components in percentage by mass: 10-90% of a carrier, 2-30% of molybdenum, 5-40% of iron and 1-10% of 2, 2-bipyridine-5-5-dicarboxylic acid. The catalyst has the advantages of simple structure, large pore structure, high stability and high strength. The catalyst is used for preparing hydrocyanic acid, high yield can be obtained, even under the condition of low ammonia-oxygen ratio, generation of by-product glycolonitrile can be effectively reduced, and selectivity of hydrocyanic acid is obviously improved.

Polyisocyanate composition and preparation method thereof

The invention discloses a polyisocyanate composition and a preparation method thereof, the polyisocyanate composition is prepared from raw materials including toluene diisocynate and a polyol compound, the polyol compound comprises trimethylolpropane and optional binary to tetrahydric alcohol with the molecular weight of 62-200, and the trimethylolpropane is trimethylolpropane or trimethylolpropane or trimethylolpropane or trimethylolpropane or trimethylolpropane or trimethylolpropane or trimethylolpropane or trimethylolpropane or trimethylolpropane. The polyisocyanate composition comprises carbamate and allophanate, and simultaneously meets the following characteristics: a, the content of 2, 4-toluene diisocyanate isomer forming the polyisocyanate composition accounts for 85% or less of the total molar weight of toluene diisocyanate forming the polyisocyanate composition, preferably 82% or less, and more preferably 80% or less; and b, the Tg of the polyisocyanate composition is greater ...

Sulfonyl isocyanate composition with improved stability and preparation method thereof

The invention relates to a sulfonyl isocyanate composition with improved stability and a preparation method of the sulfonyl isocyanate composition. The sulfonyl isocyanate composition comprises 10-8000 ppm of an isomer component and/or 0.05-5% of a sulfonamide component. The sulfonyl isocyanate composition has improved stability, after the sulfonyl isocyanate composition is stored at 50 DEG C for 6 months, the change of the mass percentage content of the isocyanate monomer compared with an initial value is less than or equal to 2%, the problems that the product purity is reduced and the color number is unstable in the storage process are solved, and a stabilizer does not need to be additionally added.

Preparation method of isocyanate alkoxy silane

The invention discloses a preparation method of isocyanate alkoxy silane, and belongs to the field of synthesis of silane coupling agents. The preparation method comprises the following steps: taking amino alkoxy silane and phosgene as reaction raw materials, and synthesizing isocyanate alkoxy silane in one step without using an acid-binding agent in a photochemical process. According to the invention, the problem of low yield of the existing method for preparing isocyanate alkoxy silane is solved, excessive phosgene and solvent can be recycled, and the utilization efficiency of phosgene is improved.

Surgical arm sliding table positioning device, surgical platform and surgical system

The invention relates to the technical field of detection mechanisms, in particular to a positioning device of an operation arm sliding table, an operation platform and an operation system. The positioning device of the operation arm sliding table comprises a sliding table upper cover and a sensor, the sensor is a three-dimensional force control sensor, and the upper end and the lower end of the three-dimensional force control sensor are induction ends; the sliding table upper cover covers the three-dimensional force control sensor and is connected with the upper end of the three-dimensional force control sensor, the sliding table comprises a sliding table outer shell, the lower end of the three-dimensional force control sensor is connected with the sliding table outer shell, and a gap is formed between the lower end of the sliding table upper cover and the sliding table outer shell. The sensor is arranged to be a three-dimensional force control sensor, and the sensor is arranged on the ...

Method for cultivating high-yield soybean plant, soybean gene and application thereof

The invention provides a method for cultivating a high-yield soybean plant, a soybean gene and application of the soybean gene, and belongs to the technical field of soybean genetic breeding. The invention aims to provide a gene and a method related to soybean yield and increase of soybean seed grain and single plant total grain weight. The invention provides a method for cultivating a high-yield soybean plant, which comprises the following steps of: 1, connecting a gene as shown in SEQ ID NO.1 with a pCAMBIA3300 vector to obtain a recombinant vector; step 2, transforming the recombinant vector in the step 1 into agrobacterium to obtain recombinant agrobacterium; and 3, transferring the recombinant agrobacterium in the step 2 into the soybean to obtain a transgenic soybean plant, and identifying to obtain a positive transgenic soybean plant. And a theoretical foundation is laid for cultivation of high-yield soybean varieties.