Abstract: A method for preparing isophorone diisocyanate by (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. The method reduces the content of hydrolyzed chlorine in the isophorone diisocyanate product, improves the yellowing resistance of the product, and the harm due to presence of hydrolyzed chlorine in the product is reduced.

Abstract: The present invention provides an isocyanurate-containing polyisocyanate composition with stable chromaticity, and a preparation method thereof, belonging to the technical field of polyisocyanate composition preparation. The preparation method comprises: an isocyanate monomer being polymerized in the presence of a catalyst, after the reaction is terminated, obtaining a prepolymer, subjecting the prepolymer to separation treatment and heat treatment, and obtaining the polyisocyanate composition containing isocyanurate; based on the weight of the polyisocyanate composition, the cleavable amine content of the polyisocyanate composition is less than or equal to 20 ppm. By means of controlling the cleavable amine content of the polyisocyanate composition, the present invention causes the resulting isocyanurate-containing polyisocyanate composition to have stable storage chromaticity, and the present invention has a chrominance increase of ?10 Hazen when stored at 40° C. for 12 months.

Abstract: A polyisocyanate composition, a preparation method therefor and an application thereof. The value of the mass content of alkaline hydrolyzed chlorine minus the mass content of water hydrolyzed chlorine in the polyisocyanate composition is 0.1 ppm-100 ppm. The mass content of the alkaline hydrolyzed chlorine is the mass content obtained by calculating halogen dissociated under alkaline conditions and/or halogen dissociated under a temperature condition of 100° C. or more as the relative atomic mass of a chlorine atom.

Abstract: A method for preparing an isocyanate in a gaseous phase by 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. Substance A is a NCO group-containing substance and/or an olefinic double bond-containing substance. The method reduces 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.

Abstract: The present invention belongs to the technical field of preparing isocyanate derivatives, and particularly relates to a storage-stable polyisocyanate composition and a preparation method therefor. The method comprises: in the presence of a catalyst system, subjecting an isocyanate monomer to a polymerization reaction; terminating the reaction after a suitable conversion rate is reached, so as to obtain a polyisocyanate reaction solution; and then performing heat treatment on the obtained polyisocyanate reaction solution to obtain a heat-treated polyisocyanate mixture, wherein the heat treatment temperature is 10-30° C. higher than the heat-sensitive temperature of the obtained polyisocyanate product, and the heat treatment time is 5-30 min; and then performing separation treatment on the heat-treated polyisocyanate mixture. When the polyisocyanate composition of the present invention is stored at 50° C.

Abstract: The present application provides a storage-stable polyisocyanate composition and a preparation method. The polyisocyanate composition is obtained by selecting one or more diisocyanate from aliphatic diisocyanates and alicyclic diisocyanates, and reacting same with an alcohol compound; the polyisocyanate composition contains an isocyanurate group, a uretdione group, a carbamate group, and an allophanate group; within the polyisocyanate composition, the molar ratio of the carbamate group/(uretdione group+isocyanurate group) is 0.01-0.2, and preferably 0.01-0.1. Compared to existing techniques, the present application has the advantage of a noticeable increase in system viscosity of uretdione polyisocyanate during storage. With the present application, by means of controlling the ratio of the carbamate group/(uretdione group+isocyanurate group) within the system, the increase in viscosity of a product during storage is inhibited, thereby improving the storage stability of the product.

Abstract: Disclosed is a 1,3-bisisocyanatomethylcyclohexane composition and an optical resin prepared therefrom. The composition comprises, based on the weight of 1,3-bisisocyanatomethylcyclohexane, a) 65%-95 wt % of trans-1,3-bisisocyanatomethylcyclohexane; b) greater than 0 and less than or equal to 0.5 wt %, preferably 0.02-0.5 wt % of 1,4-bisisocyanatomethylcyclohexane. Preferably, the 1,3-bisisocyanatomethylcyclohexane composition contains greater than 0 and less than or equal to 600 ppm of 1-isocyanatomethyl-3-methylcyclohexane, based on the weight of 1,3-bisisocyanatomethylcyclohexane. The 1,3-bisisocyanatomethylcyclohexane composition is used for preparing an optical resin, which can be applied to produce an optical lens with a better performance in preventing opacification and optical distortion.

Abstract: Disclosed is an aliphatic polyisocyanate composition, wherein the molar ratio of an iminooxadiazinedione structure to an isocyanurate structure is 0.01-0.8:1, and the molar ratio of an iminooxadiazinedione structure in a polymer larger than three molecules to the iminooxadiazinedione structure in the composition is 0.2-0.8:1. Provided are a method for preparing the aliphatic polyisocyanate composition, and a coating composition. The aliphatic polyisocyanate composition has both a lower viscosity and a better crosslinking property. The composition can significantly reduce the usage amount of a solvent when used in a coating composition, is more environmentally friendly and also has a better paint film property. The preparation method has a simple process and mild conditions, is easy to operate and control, and is suitable for industrial scale production.

Abstract: Preparation method for a polyurethane optical resin and applications thereof. The preparation method for the polyurethane optical resin comprises: a raw material composition comprising isocyanate and a polythiol compound undergoes a polymerization to produce the polyurethane optical resin. The turbidity value of the isocyanate used in the raw material composition is controlled at ?2 NTU. The polyurethane optical resin produced is applicable in manufacturing optical products.

Abstract: A method for preparing an isocyanate in a gaseous phase by 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. Substance A is a NCO group-containing substance and/or an olefinic double bond-containing substance. The method reduces 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.

Abstract: A method for preparing isophorone diisocyanate by (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. The method reduces the content of hydrolyzed chlorine in the isophorone diisocyanate product, improves the yellowing resistance of the product, and the harm due to presence of hydrolyzed chlorine in the product is reduced.

Abstract: An isocyanate polymerization catalyst, a preparation method thereof and a method for preparing polyisocyanates comprising isocyanurate groups by using the same. The catalyst is a carboxylic acid salt containing a di-quaternary ammonium ion. The structure of the catalyst contains hydroxyl-containing aromatic heterocyclic residues. The catalyst is highly active. Only a small quantity of the catalyst is required for the polymerization of isocyanates. The prepared polyisocyanates have color values lower than 25 Hazen, monomer contents of less than 0.5% by weight, high contents of isocyanurates and low viscosities.

Abstract: Disclosed is an imine-type quaternary ammonium salt catalyst, wherein the catalyst has a general structure formula shown by formula I below; in the formula, R1 and R2, respectively, are independently selected from a C1-C20 linear alkyl or a branched C3-C20 alkyl, and a C1-C20 hydroxylalkyl, a C3-C8 cycloalkyl, and arylated alkyl; R3 is a linear or branched alkyl, cycloalkyl or aryl; and R4 is hydrogen, aryl, a linear C1-C15 alkyl or branched C3-C15 alkyl. Also disclosed are a method for preparing the catalyst and a polyisocyanate composition prepared therefrom. The catalyst, by introducing an imine structure, on the basis of ensuring high catalytic activity thereof, is allowed to have properties of high temperature decomposition and inactivation, and when applied to the synthesis of polyisocyanate, can effectively prevent the risk of explosive polymerization caused by an uncontrolled reaction.

Abstract: Disclosed is an imine-type quaternary ammonium salt catalyst, wherein the catalyst has a general structure formula shown by formula I below; in the formula, R1 and R2, respectively, are independently selected from a C1-C20 linear alkyl or a branched C3-C20 alkyl, and a C1-C20 hydroxylalkyl, a C3-C8 cycloalkyl, and arylated alkyl; R3 is a linear or branched alkyl, cycloalkyl or aryl; and R4 is hydrogen, aryl, a linear C1-C15 alkyl or branched C3-C15 alkyl. Also disclosed are a method for preparing the catalyst and a polyisocyanate composition prepared therefrom. The catalyst, by introducing an imine structure, on the basis of ensuring high catalytic activity thereof, is allowed to have properties of high temperature decomposition and inactivation, and when applied to the synthesis of polyisocyanate, can effectively prevent the risk of explosive polymerization caused by an uncontrolled reaction.

Abstract: A heater for heating and vaporizing droplets in gas stream, comprising a heater housing and a heater body located inside the heater housing, wherein the heater housing is provided with an airflow inlet and an airflow outlet, the airflow enters into the heater housing via the airflow inlet, flows through the heater body, and then is discharged via the airflow outlet; the heater body comprises a stereoscopic network structure formed by interweaving one or more electrical heating wires. The use of the heater and a method for preparing isocyanate using the heater. The heater has a simple structure, a low pressure loss, uniform heating and a high heat utilization ratio during preparing isocyanate.

Abstract: An isocyanate polymerization catalyst, a preparation method thereof and a method for preparing polyisocyanates comprising isocyanurate groups by using the same. The catalyst is a carboxylic acid salt containing a di-quaternary ammonium ion. The structure of the catalyst contains hydroxyl-containing aromatic heterocyclic residues. The catalyst is highly active. Only a small quantity of the catalyst is required for the polymerization of isocyanates. The prepared polyisocyanates have color values lower than 25 Hazen, monomer contents of less than 0.5% by weight, high contents of isocyanurates and low viscosities.

Abstract: A method for continuously preparing biuret polyisocyanate, comprising: a mixed solution of a diisocyanate and a catalyst with water vapour, in an aerosol form, are continuously reacted in a first reactor; the product obtained therefrom is brought into a second reactor for a further reaction; a tail gas from the second reactor is condensed and refluxed, and the non-condensable gas is brought into a tail gas treatment system; a reaction liquid obtained in the second reactor is further reacted in a third reactor; and then separation is performed for removing monomers, so as to obtain biuret polyisocyanate.

Abstract: A heater for heating and vaporizing droplets in gas stream, comprising a heater housing and a heater body located inside the heater housing, wherein the heater housing is provided with an airflow inlet and an airflow outlet, the airflow enters into the heater housing via the airflow inlet, flows through the heater body, and then is discharged via the airflow outlet; the heater body comprises a stereoscopic network structure formed by interweaving one or more electrical heating wires. The use of the heater and a method for preparing isocyanate using the heater. The heater has a simple structure, a low pressure loss, uniform heating and a high heat utilization ratio during preparing isocyanate.

Abstract: A method for continuously preparing biuret polyisocyanate, comprising: a mixed solution of a diisocyanate and a catalyst with water vapour, in an aerosol form, are continuously reacted in a first reactor; the product obtained therefrom is brought into a second reactor for a further reaction; a tail gas from the second reactor is condensed and refluxed, and the non-condensable gas is brought into a tail gas treatment system; a reaction liquid obtained in the second reactor is further reacted in a third reactor; and then separation is performed for removing monomers, so as to obtain biuret polyisocyanate.

Abstract: The present invention provides a flow duct type jet reactor and a process for preparing isocyanates using it. The flow duct type jet reactor situates flow ducts in inner feed pipe which form whirlpool and reinforce vortex, thereby amine steam rapidly admixes and reacts with phosgene, and the byproducts are reduced. In addition, the present process uses a jet-absorption apparatus which rapidly cools the high temperature gas discharged from the reactor to a temperature at which the product is thermally stable, and at the same time provides negative pressure for the reaction process of the system, and thus saving bulky vacuum system.