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Industrial production process for high-quality aromatic polycarbonate

A polycarbonate and aromatic technology, applied in the field of high-quality and high-performance aromatic polycarbonate, can solve problems such as unrecorded hints, undisclosed, difficulties, etc.

Active Publication Date: 2008-12-10
ASAHI KASEI KK
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, there are many following problems in this interfacial polycondensation method: toxic phosgene must be used; a very large amount of dichloromethane, which is more than ten times the amount of polycarbonate, is harmful to health and the environment as a polymerization solvent; by-product hydrogen chloride, Chlorine-containing compounds such as sodium chloride and dichloromethane by-products corrode devices; difficulties are encountered in separating chlorine-containing residual impurities such as sodium chloride and dichloromethane, which have a bad influence on polymer properties; and dichloromethane must be treated A large amount of process wastewater such as methane and unreacted bisphenol A
[0017] However, in all existing documents proposing the preparation of aromatic carbonates by these reactive distillation methods, there is no specific method or device that can be mass-produced on an industrial scale (for example, 1 ton per hour) at all, and there is no description of their hints

Method used

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  • Industrial production process for high-quality aromatic polycarbonate
  • Industrial production process for high-quality aromatic polycarbonate
  • Industrial production process for high-quality aromatic polycarbonate

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0341] (1) Continuously prepare the operation (I) of diphenyl carbonate

[0342]

[0343] use figure 1 L as shown 1 =3300cm, D 1 =500cm, L 1 / D 1 =6.6,n 1 =80,D 1 / d 11 =17,D 1 / d 12 =9 continuous multistage distillation columns. In addition, in this embodiment, as an inner part, a cross-sectional area of ​​each hole = about 1.5 cm 2 , with the number of holes = about 250 / m 2 perforated trays.

[0344]

[0345] use figure 2 L as shown 2 =3100cm, D 2 =500cm, L 2 / D 2 =6.2,n 2 =30,D 2 / d 21 =3.85,D 2 / d 22 =11.1 continuous multistage distillation column. In addition, in this embodiment, as internal parts, 2 Mellapaks (a total of 11 theoretical stages) are installed in the upper part, and the cross-sectional area of ​​each hole = about 1.3 cm is used in the lower part. 2 , with the number of holes = about 250 / m 2 perforated trays.

[0346]

[0347] use image 3 The first continuous multistage distillation column 101 as shown and the second continuo...

Embodiment 2

[0362] (1) Continuously prepare the operation (I) of diphenyl carbonate

[0363] Using the same apparatus as in Example 1, reactive distillation was performed under the following conditions.

[0364] The raw material 1 containing phenol / dimethyl carbonate = 1.1 (weight ratio) was continuously introduced in a liquid state at a flow rate of 40 tons / hour from the upper introduction port 11 of the first continuous multistage distillation column 101 . On the other hand, the raw material 2 containing dimethyl carbonate / phenol=3.9 (weight ratio) was continuously introduced in a gaseous state at a flow rate of 43 tons / hour from the lower introduction port 12 of the first continuous multistage distillation column 101. The molar ratio of the raw materials introduced into the first continuous multistage distillation column 101 was dimethyl carbonate / phenol=1.87. This raw material does not substantially contain halogen (beyond the detection limit of ion chromatography, 1 ppb or less). C...

Embodiment 3

[0375] (1) Continuously prepare the operation (I) of diphenyl carbonate

[0376] The cross-sectional area of ​​each hole of the perforated tray in the second continuous multistage distillation column 201 = about 1.8 cm 2 , except that, using the same apparatus as in Example 1, reactive distillation was carried out under the following conditions.

[0377] The raw material 1 containing phenol / dimethyl carbonate = 1.7 (weight ratio) was continuously introduced in a liquid state at a flow rate of 86 tons / hour from the upper introduction port 11 of the first continuous multistage distillation column 101 . On the other hand, the raw material 2 containing dimethyl carbonate / phenol = 3.5 (weight ratio) was continuously introduced in a gaseous state at a flow rate of 90 tons / hour from the lower introduction port 12 of the first continuous multistage distillation column 101 . The molar ratio of the raw materials introduced into the first continuous multistage distillation column 101 wa...

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Abstract

Disclosed is a specific process for producing a high-quality / high-performance aromatic polycarbonate free from discoloration and having excellent mechanical properties from a dialkyl carbonate and an aromatic dihydroxy compound stably, in an industrially large scale (e.g., 1 ton or more per hour) for a prolonged period of time (e.g., for 1000 hours or longer, preferably 3000 hours or longer, more preferably 5000 hours or longer). The process comprises the steps of: (I) producing a diaryl carbonate with two reactive distillation columns each having a specific structure; (II) purifying the diaryl carbonate to yield a highly pure diaryl carbonate; (III) preparing a molten prepolymer from an aromatic dihydroxy compound and the highly pure diaryl carbonate and treating the molten prepolymer with a guide contact flow-down type polymerizer having a specific structure to produce a desired aromatic polycarbonate; and (IV) recycling an aromatic monohydroxy compound, which is a by-product in the reaction in step (III), into step (I).

Description

technical field [0001] The present invention relates to the industrial preparation method of aromatic polycarbonate. More specifically, the present invention relates to a method for industrially producing a high-quality, high-performance aromatic polycarbonate having excellent mechanical properties without coloration, in large quantities, from a dialkyl carbonate and an aromatic dihydroxy compound, stably over a long period of time. Background technique [0002] In recent years, aromatic polycarbonates have been widely used in various fields as engineering plastics excellent in heat resistance, impact resistance, and transparency. Regarding the production method of this aromatic polycarbonate, various studies have been conducted so far, in which an aromatic dihydroxy compound such as 2,2-bis(4-hydroxyphenyl)propane (hereinafter referred to as bisphenol A) The method of interfacial polycondensation with phosgene has been industrialized. However, there are many following pro...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C08G64/30B01D3/14B01D3/22C07C68/06C07C69/96
CPCB01D3/009C07C68/06C08G64/307Y02P20/10C07C69/96B01D3/14C08G64/20C08G64/30
Inventor 福冈伸典宫地裕纪八谷广志松崎一彦
Owner ASAHI KASEI KK
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