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Method for preparing polycarbonate

A polycarbonate and polyethylene glycol technology is applied in the field of polymer material preparation to achieve the effects of reducing dosage, increasing utilization rate and improving utilization rate

Inactive Publication Date: 2010-06-16
CHINA NAT BLUESTAR GRP CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

In recent years, for example, described in U.S. Patent No. 5,391,692, it has been found that phase transfer catalysts quaternary ammonium halides and quaternary phosphorus halides can replace tertiary amines as catalysts for polycarbonate interfacial preparation methods, thereby increasing the phosgene Utilization, however, the use of these catalysts also inhibits the conversion of chloroformate-terminated intermediate polymers into useful species, such as end- or hydroxyl-terminated polycarbonates, while generating concomitant chloroformate-terminated end product
Since the presence of chloroformate-terminated species is generally undesirable in polycarbonate products, the use of quaternary ammonium halides and quaternary phosphorus halides as catalysts, although able to improve phosgene utilization, has not been widely adopted on an industrial scale. use
[0005] U.S. Patent No. 5,519,105 and U.S. No. 5,510,449 disclose that the combined use of phase transfer catalysts and tertiary amines can increase the effective utilization rate of carbonyl chloride, and simultaneously improve the conversion rate of chloroformate-terminated polymers into useful products, However, the combined use of the two catalysts has its disadvantages, such as the production system including the need to use two independent processes for recovering the catalyst

Method used

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  • Method for preparing polycarbonate
  • Method for preparing polycarbonate

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0033] The synthesis of embodiment 1 amphiphilic macromolecular catalyst

[0034] Taking polyethylene glycol-block-poly-4-vinylpyridine as an example, the synthesis of amphiphilic macromolecular catalysts is divided into the following four steps:

[0035] 1. Synthesis of Dithiobenzoic Acid

[0036] 1.1 Grignard reagent preparation

[0037] Bromobenzene (5.6g, 0.036mol) and magnesium sticks (0.82g, 0.036mol) were stirred in THF (100ml) to obtain Grignard reagent.

[0038] 1.2 Synthesis of dithiobenzoic acid

[0039] At -5°C, a THF solution (30ml) of carbon disulfide (2.7g, 0.036mol) was added to the above Grignard reagent solution, and reacted for 1h. Then 5 mL of water was added dropwise and stirring was continued for 30 min. Suction filtration, remove THF under reduced pressure. Add dilute hydrochloric acid to acidify (10%, v / v), CH 2 Cl 2extraction. The organic phase was extracted three times with cold NaOH solution (10%), acidified and extracted. repeat three times...

Embodiment 2

[0055] Dissolve 6.03g of bisphenol A, 2.2012g of sodium hydroxide, 48mg of sodium dithionite and 4mg of tert-butylphenol in 44mL of water to form an aqueous phase, stir, and the pH is 12.

[0056] 10 mg of polyethylene glycol-block-poly-4-vinylpyridine (wherein n is 10) prepared by the method described in Example 1 was dissolved in 2 mL of dichloromethane and added to the above system; then 1.263 g of triphosgene Dissolved in 12mL of dichloromethane. Add the dichloromethane solution of triphosgene into the system, stir, and react at 30°C for 30 minutes, and keep the pH value of the system at 10-10.5 during the reaction.

[0057] Upon completion of the phosgenation reaction, chloroformate was detected using 4-(4-nitrobenzyl)pyridine (NBP) as described by A.N. Agree et al. (talanta, 1996, vol. 13. p. 1151-1160). The measured chloroformate content was 4.89% (mass fraction). No phenol precipitates out after the wastewater phase is acidified after the reaction. The above procedu...

Embodiment 3

[0059] The steps of Example 2 were repeated, except that the amount of polyethylene glycol-block-poly-4-vinylpyridine added was 73.7 mg, and the content of chloroformate was determined to be 0.5% (mass fraction).

[0060] And when adding equimolar equivalent triethylamine 1.5mL as catalyst in the reaction mixture, it was found that the chloroformate in the product obtained could not be detected, indicating that the chloroformate in the polymer was completely hydrolyzed.

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Abstract

The invention relates to a method for preparing polycarbonate. The method utilizes an interface method, and comprises the steps of: mixing alkaline aqueous solution of one or more dihydroxy aromatic hydrocarbons and organic solution of carbonyl chloride(phosgene); controlling the pH value to be between 9 and 12.5 in the whole process; and performing an interfacial polymerization reaction of a phenol chain terminator, the dihydroxy aromatic hydrocarbons and the phosgene in the presence of a catalyst, namely an amphiphilic block copolymer to prepare the polycarbonate. The method utilizes the amphiphilic block copolymer as the catalyst for preparing the polycarbonate by the interface method, which can increase the utilization rate of the carbonyl chloride, reduce the consumption of the carbonyl chloride, and improve the utilization rate of bisphenol; the catalyst can promote the rapid transformation of chloroformate and obtain a polycarbonate product with low inclusion amount of dihydroxy aromatic compounds; and no phenol precipitations are precipitated after a wastewater phase is acidified, and a catalyst material can be treated and recovered by adopting a conventional method.

Description

technical field [0001] The invention relates to the field of polymer material preparation, in particular to a method for preparing polycarbonate, wherein an amphiphilic block copolymer is used as a phase transfer catalyst and a condensation catalyst. Background technique [0002] Polycarbonate (Polycarbonate, PC) is a high-performance polymer material, widely used as an engineering plastic in the fields of automobiles, electrical appliances, construction and household appliances. [0003] The industrial production of polycarbonate is mainly carried out by the interface method, that is, the alkaline aqueous solution of one or several dihydroxy aromatic hydrocarbons is mixed with the organic solution of carbonyl chloride (phosgene) and then subjected to photochemical reaction to form a prepolymer. , adding a molecular weight terminator or branching agent, catalyst, etc., for interfacial polymerization to generate polycarbonate. Although practice has proved that organic tertia...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C08G64/20C08G64/24
Inventor 张希文朱栋栋胡衍平
Owner CHINA NAT BLUESTAR GRP CO LTD
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