- Formation and Depolymerization of Oligomers during Thermal Cracking of Silicon-Containing Carbamates
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Polymerization reactions in the thermal cracking of N-substituted carbamates to produce the corresponding isocyanates significantly reduce the yield of isocyanates and thus vastly hinder the industrial application of such non-phosgene routes. Herein, we tried to recycle the oligomers generated during the thermal cracking of 3-ethylcarbamatopropyltriethoxysilane (CPTS) to produce 3-isocyanatopropyltriethoxysilane (IPTS). Firstly, the polymerized substrates of the pyrolysis reaction were analyzed by NMR, IR, MALDI-TOF-MS and TG, indicating the pyrolysis substrates were mixtures of CPTS (25 wt%), polyureas (74 wt%), imines, and other compounds (a carbonyl group source, but also forms hydrogen bonds with polyureas. In addition, NH3 co-produced can also modify the reaction system microenvironment, which might be favorable for the dissociation of polyureas. With optimized conditions, more than 96 % of polymerized substrates could be reverted to CPTS for secondary cracking.
- Wang, Peixue,Zhou, Dawei,Fei, Yuqing,Long, Yan,Deng, Youquan
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- The isocyanate group-containing alkoxysilane method (by machine translation)
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[Problem] an isocyanate group-containing alkoxysilane isocyanate group-containing alkoxysilane having high purity can be efficiently produced. [Solution] The amino group-containing alkoxysilane is reacted with dialkyl carbonate, carbamate alcohol mixture is obtained. Then, the mixture was heated to obtain an isocyanate group-containing alkoxysilanes. In this case, alcohol-containing fractions of 1 second, isocyanate group-containing alkoxysilane containing 2 fractions of a second, annular byproducts including 3 a fraction is obtained. The, the first fraction of the heated mixture before mixing 3, annular reaction byproduct alcohol, cyclic carbamate returned products. Figure 1 [drawing] (by machine translation)
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Paragraph 0084; 0089-0094
(2020/10/03)
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- Preparation method of 3-isocyanate propyltriethoxysilane
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The invention relates to a preparation method of 3-isocyanate propyltriethoxysilane, belonging to the field of fine chemical synthesis. The method comprises synthesizing the 3-isocyanate propyltriethoxysilane from chloropropyltriethoxysilane and potassium cyanate through one-step synthesis in an ionic liquid adopted as a solvent under a catalysis function. An isocyanate process is adopted, and aiming at disadvantages, of the process, that reaction raw materials are difficult to dissolve and yields are low, the preparation method of the 3-isocyanate propyltriethoxysilane based on the ionic liquid is provided.
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Paragraph 0033-0058
(2019/11/21)
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- Method for preparing isocyanate-based silane by hydrosilylation reaction
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The invention relates to a synthetic method of an isocyanate-based silane coupling agent and belongs to the field of synthesis of silane coupling agents. The preparation method comprises the followingsteps: taking allyl urea and sodium nitrite as main raw materials, taking toluene as a solvent, and taking tetra-n-butyl ammonium bromide as a catalyst to synthesize allyl isocyanate; then, under theaction of a noble metal catalyst such as platinum or rhodium, carrying out hydrosilylation with silicon-hydrogen bond containing hydrogenalkoxysilanes such as trimethoxy silane, triethoxy silane andthe like for carrying out a reaction to generate an isocyanate-based silane coupling agent crude product; and then carrying out reduced pressure distillation treatment to obtain the isocyanate-based silane coupling agent product. The method has the advantages of simple operation, high reaction conversion rate, high yield, stable quality, safe environment-friendly energy-saving efficient productionprocess, and the like, and industrial production is easy to realize.
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Paragraph 0026; 0027
(2019/10/01)
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- Preparation method of 3-isocyanatopropyltrialkoxysilane
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A preparation method of 3-isocyanatopropyltrialkoxysilane comprises the steps of (1) mixing 3-chloropropyltrialkoxysilane, urea and ammonium salt, heating to 120-130 DEG C, stirring to allow reactingfor 2-3 hours, cooling, and removing solid by centrifuging or filtering; (2) adding the separated liquid into a manganese or cobalt carboxylate catalyst, heating to 150-200 DEG C under nitrogen protection, and stirring to allow reacting for 1-2 hours; (3) sampling the reaction product, rectifying under reduced pressure after qualification is confirmed by detection, and separating the target product. The preparation method has the advantage of evidently reduced production cost.
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Paragraph 0018; 0020
(2019/03/25)
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- MANUFACTURING METHOD OF CARBAMATE ALKYLSILANE
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PROBLEM TO BE SOLVED: To provide a manufacturing method capable of providing carbamate alkylsilane effectively from a reaction mixture obtained from a reaction of aminoalkylsilane and a carbonic ester compound at high purity and high yield. SOLUTION: There is provided a manufacturing method of carbamate alkylsilane of the formula (3) by distilling a reaction mixture obtained by reacting an organic silicate compound represented by the formula (1) and a carbonic ester compound represented by the formula (2) in a presence of a metal catalyst containing one or more kinds of metal selected from Mn and Zn. R1 is a substituted/unsubstituted bifunctional hydrocarbon group with 3 to 6 carbon atoms, R2 and R3 are each independently a substituted/unsubstituted C1 to 10 monovalent hydrocarbon group and n is an integer of 0 to 2. R4 is each independently a substituted/unsubstituted C1 to 10 monovalent hydrocarbon group. SELECTED DRAWING: None COPYRIGHT: (C)2018,JPOandINPIT
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Paragraph 0045
(2018/03/23)
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- Process for preparation of silicon-containing isocyanate compounds
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A silicon-containing isocyanate compound represented by the following general formula [I]: STR1 wherein each of R1, R2, and R3 independently represents a hydrocarbon group having 1 to 10 carbon atoms, an alkoxy group having 1 to 6 carbon atoms or a trialkyl siloxy group (each alkyl having 1 to 4 carbon atoms), with the proviso that at least one of R1, R2, and R3 is an alkoxy group having 1 to 6 carbon atoms, and n is a number of from 1 to 4, can be obtained in a high yield by reacting carbonyl chloride with a silicon-containing alkylamine represented by the following general formula [II]: STR2 wherein R1, R2, R3, and n are as defined above, in an inert organic solvent in the presence of a tertiary amine. If a filtrate remaining after removal of a tertiary amine hydrochloride from the reaction liquid, a liquid remaining after removal of the solvent from the filtrate, or a distillate formed by distillation of this liquid is treated with an alkali metal salt or alkaline earth metal salt of higher fatty acid or an aromatic carboxylic acid, the intended product can be obtained at a high purity in a high yield.
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