Wanhua Chemical Beijing Co., Wanhua Chemical Group Co. and Wanhua Chemical Ningbo Co. | Date: 2014-02-11
The present invention relates to a method for preparing TDI (toluene diisocyanate) isocyanurate by using TDI, monohydric alcohol, solvent, antioxidant, catalyst and termination agent as the raw materials. The properties of the isocyanurate are improved by the process comprising the modification by monohydric alcohol and addition of the catalyst and solvent in several stages at an appropriate temperature. By adding the catalyst and solvent in batches at the condition of controlling both NCO % and the viscosity in the preparation process, and adjusting the solid content at each step, the resulting TDI isocyanurate has low content of free TDI, high xylene tolerance, small product color number, and high performance stability, which makes the product obtained by the isocyanurate have good application properties such as the drying, polishing and extinction properties of coating film, and such isocyanurate has good compatibility with other components.
Wanhua Chemical Ningbo Co. and Wanhua Chemical Group Co. | Date: 2011-09-06
Provided is a 3-aminomethyl-3,5,5-trimethylcyclohexylamine preparation method. A feeding flow of 3-cyano-3,5,5-trimethylcyclohexylimine is reacted with NH3 and hydrogen in the presence of a hydrogenation catalyst; the method is characterized by: firstly adding a basic compound to the feeding flow of 3-cyano-3,5,5-trimethylcyclohexylimine, and then after a portion of 3-cyano-3,5,5-trimethylcyclohexylimine has reacted, adding an acidic compound to reaction materials for further hydrogenation reaction to prepare the product. The method ensures that the aminonitrile content in the product is low, thus effectively reducing the duration of the reaction and greatly reducing the consumption of the catalyst during the hydrogenation reaction process.
Wanhua Chemical Ningbo Co. and Wanhua Chemical Group Co. | Date: 2012-05-26
A process of producing chlorine gas by catalytic oxidation of hydrogen chloride including: incorporating an oxidizing agent such as ozone, hydrogen peroxide solution etc. into a gas stream of hydrogen chloride containing impurities, conducting oxidation pretreatment of the gas stream under the action of ultrasonic wave, such that the impurities contained in the gas stream are oxidized; wherein the oxidizing agent does not generate additional or new impurities in the reaction system, where the gas stream obtained after the oxidation pretreatment is allowed to pass through a separating device wherein the oxidized impurities in the form of liquid and/or the oxidized impurities in the form of solid are removed from the gas stream so as to obtain a purified gas stream of hydrogen chloride, and thereafter the purified gas stream of hydrogen chloride is well mixed with a gas stream containing molecular oxygen, the resultant gas mixture is preheated to a reaction temperature, and then catalytically oxidized to produce chlorine gas, thus by means of oxidation pretreatment and separation, the process can remove efficiently the sulfur-containing impurities, the halogen-containing impurities, hydrocarbon impurities and the like from the gas stream of hydrogen chloride, and does not generate additional impurities.
Wanhua Chemical Group Co. and Wanhua Chemical Ningbo Co. | Date: 2013-05-09
The present invention relates to a composite catalyst, preparation process thereof, and process for catalyzing the trimerization of butadiene using the composite catalyst. The composite catalyst comprises: (A) a titanium compound catalyst active component, (B) an organometallic compound co-catalyst component, (C) a sulfoxide compound catalyst-modifying component, (D) a monoester compound catalyst-modifying component, and (E) a solvent component. The composite catalyst has advantages of excellent selectivity, high catalytic activity, easy preparation and so on.
Wanhua Chemical Group Co. and Wanhua Chemical Ningbo Co. | Date: 2012-12-07
The present invention provides a method for preparing 3-aminomethyl-3,5,5-trimethyl cyclohexylamine. The method comprises: a) reacting 3-cyano-3,5,5-trimethyl cyclohexanone with excess primary amine as well as removing the water generated from the reaction, so that IPN is substantially converted into imine compounds; b) in the presence of an ammonolysis catalyst, mixing the product of step a) with liquid ammonia, making the imine compound perform ammonolysis reaction to generate 3-cyano-3,5,5-trimethyl cyclohexylimine and the primary amine; and c) in the presence of hydrogen and a hydrogenation catalyst, hydrogenating 3-cyano-3,5,5-trimethyl cyclohexylimine obtained in step b) to obtain 3-aminomethyl-3,5,5-trimethyl cyclohexylamine. The method of the present invention avoids the generation of 3,5,5-trimethyl cyclohexanol and 3-aminomethyl-3,5,5-trimethyl cyclohexanol as the major by-products in the prior art, thereby improving the yield of 3-aminomethyl-3,5,5-trimethyl cyclohexylamine.