24801-88-5Relevant articles and documents
Formation and Depolymerization of Oligomers during Thermal Cracking of Silicon-Containing Carbamates
Wang, Peixue,Zhou, Dawei,Fei, Yuqing,Long, Yan,Deng, Youquan
, p. 1039 - 1045 (2019)
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.
Preparation method of 3-isocyanatopropyltrialkoxysilane
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Paragraph 0018; 0020, (2019/03/25)
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.
Method for preparing isocyanate-based silane by hydrosilylation reaction
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Paragraph 0026; 0027, (2019/10/01)
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.