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Alpha-methyl phenylethylene unstaturated dimer preparing method

A methyl styrene, unsaturated technology, applied in the field of preparation of α-methyl styrene unsaturated dimer, can solve the problem of high polymer yield, achieve high reaction rate, simple separation method, high activity effect

Active Publication Date: 2006-10-25
CHINA PETROLEUM & CHEM CORP +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Its characteristics are: less catalyst consumption, high activity, and fast reaction speed; but the high polymer yield in the product is high, and the separation of the catalyst needs to be washed with water and alkali, and there are environmental protection problems and problems such as product chromaticity and stability.

Method used

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Examples

Experimental program
Comparison scheme
Effect test

example 1

[0019] This example describes H 3 PW 12 o 40 nH 2 O catalyst preparation.

[0020] NaH with a molar ratio of 1:8 2 PO 12 12H 2 O and Na 2 WO 4 2H 2 O was dissolved in 6 times the weight of water, heated to 70°C, under the condition of continuous stirring, adding a strong inorganic acid to keep the pH value of the solution at about 0, continuing to heat and reflux for 2 hours, then cooling to room temperature, adding ether to extract, and After the ether is removed from the extract, the solid obtained is H 3 PW 12 o 40 .

example 2

[0022] This example describes Cs 2.5 h 0.5 PW 12 o 40 Catalyst preparation.

[0023] (1) Accurately weigh 11.3122gH 3 PW 12 o 40 21H 2 O is dissolved in water to make a 10% aqueous solution;

[0024] (2) According to the requirements of stoichiometry, accurately weigh 1.4149g of anhydrous Cs 2 CO 3 (analytical pure) dissolved in water to form a 5% aqueous solution;

[0025] (3) under continuous stirring, the Cs 2 CO 3 The solution is continuously and slowly added dropwise to the phosphotungstic acid solution. After the dropwise addition is completed, continue to stir for 30 minutes, then evaporate the excess water, and the solid obtained after fine grinding is the required catalyst Cs 2.5 h 0.5 PW 12 o 40 .

example 3

[0027] This example describes H 3 PW 12 o 40 / Preparation of silica gel catalyst.

[0028] 1. Set the specific surface area to 324m 2 / g of silica gel with a pore size of 9.2nm was treated at 150°C for 4 hours. After cooling to room temperature, weigh 40.0 g for later use.

[0029] 2. Accurately weigh 11.3122gH 3 PW 12 o 40 21H 2 O was dissolved in water to form a 15% solution, and quickly poured into the above prepared silica gel. Stand for 3 hours, then dry to remove excess water, that is, 20% H 3 PW 12 o40 / Silica gel.

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PUM

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Abstract

A kind of preparation method of α-methylstyrene unsaturated dimer, comprising: by loaded type heteropolyacid compound and C 2 ~C 6 In the presence of a co-catalyst composed of aliphatic diol compounds, dimerize α-methylstyrene at a temperature of 50-100°C, wherein the weight ratio of co-catalyst to α-methylstyrene monomer is 0.1 % to 1.4%. Compared with the prior art, the method provided by the invention has the following advantages under the premise of maintaining high target product selectivity: high catalyst activity, high reaction rate, mild reaction conditions, low yield of high polymer, catalyst and reaction mixture The separation method is simple, there is no subsequent water washing and alkali washing treatment process, and the catalyst can be reused.

Description

technical field [0001] The present invention relates to a process for the preparation of unsaturated dimers of alpha-methylstyrene. Specifically, the present invention relates to a method for synthesizing an unsaturated dimer of alpha-methylstyrene by using a supported heteropolyacid as a catalyst for dimerization of alpha-methylstyrene. technical background [0002] The role of α-methylstyrene unsaturated dimer is very wide. It can be used as a molecular weight regulator in the production of copolymers such as ABS resin, AS resin, PS and SBR, replacing tetrachloromethane, dodecanethiol and other types of molecular weight regulators. Tetrachloromethane was decided to abolish its use at the end of 1995 at the Montreal International Conference in 1992 because of its damage to the ozone layer, while the use of dodecyl mercaptan was gradually controlled due to the odor pollution caused in the process of handling and use. Therefore, α-methylstyrene unsaturated dimers, especiall...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07C15/40C07C2/02
Inventor 卜嘉川梁宇翔汪孟言杜泽学
Owner CHINA PETROLEUM & CHEM CORP