Industrial process for production of high-purity diaryl carbonate

A kind of technology of diaryl carbonate and dialkyl carbonate, which is applied in the industrial preparation field of high-purity diaryl carbonate, and can solve the problems such as the existence of by-products with a middle boiling point and a method for removing them which are not disclosed.

Active Publication Date: 2007-09-26
ASAHI KASEI KK
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

And so far there is no literature disclosing the existence of these middle-boiling point by-products and their removal methods at all.

Method used

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  • Industrial process for production of high-purity diaryl carbonate
  • Industrial process for production of high-purity diaryl carbonate

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0246]

[0247] Using this L=3100cm, D=500cm, L / D=6.2, n=30, D / d shown in Figure 1 1 =3.85, D / d 2 =11.1 continuous multistage distillation column. In addition, in this embodiment, as internal parts, two Mellapak (metal orifice corrugated packing) (the total number of stages is 11) are arranged on the upper part, and the lower part uses 2 , The number of holes is about 250 / m 2 perforated trays.

[0248]

[0249] Using L as shown in Figure 2 A =1700cm, D A =340cm, and set n A As the separation column A, a continuous multistage distillation column with a Mellapak of =30 as internals was used.

[0250]

[0251] Using L as shown in Figure 2 B =2200cm, D B =280cm, and set n 1 =12, n 2 =18,n 3 =5 continuous multi-stage distillation columns with 3 Mellapaks as internals were used as the refining column B.

[0252]

[0253] Using L as shown in Figure 2 C =1500cm, D C =150cm, and set n 4 = 6, n 5 =10, n 6 3 Mellapaks of =7 are as the continuous multi-stage disti...

Embodiment 2

[0268] In addition to changing the distillation and separation conditions, the bottom temperature of the high boiling point material separation tower A is 210°C, the top pressure is 3800Pa, and the reflux ratio is 0.61, the bottom temperature of the diaryl carbonate refining tower B is 220°C, Top pressure is 6700Pa, reflux ratio is 1.5, and the tower bottom temperature of middle boiling point substance separation tower C is that 200 ℃, tower top pressure are 2400Pa, reflux ratio are except the condition of 0.35, carry out reactive distillation and by the method identical with embodiment 1 Separated by distillation. After 500 hours and 1000 hours, the purity of diphenyl carbonate was 99.999% by mass or higher, and the contents of the middle-boiling point by-products and high-boiling point by-products were all 1 ppm or less and could not be detected. In addition, in this diphenyl carbonate, no halogen was detected (1 ppb or less).

Embodiment 3

[0270] An aromatic polycarbonate was prepared by the method described in Example 1 of International Publication No. 99 / 64492 using the diphenyl carbonate obtained in Example 1. The obtained aromatic polycarbonate having a number average molecular weight of 10500 was injection-molded at 310° C. to produce a test piece (thickness: 3.2 mm). b of the test piece * The value (numerical value representing the degree of yellowness by the CIELAB method) was 3.2, which was completely free of yellow, colorless, and very excellent in transparency. After pulverizing these test pieces with a crusher, injection molding was repeated 5 times at 310°C, and b of the obtained test pieces * The value was 3.5, and no significant coloring was found. In addition, test pieces (b) produced by injection molding the aromatic polycarbonate were carried out * Value = 3.2) heat aging test (120 ° C, 500 hours), b * The value was 3.5, and no significant coloring was found.

[0271] In addition, b of an a...

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Abstract

The invention provides a specific method to provide a raw material of a reaction mixture containing creosote alkylaryl aster through the ester interchange reaction of creosote dialkyl ester and aromatic single hydroxyl compound and to steadily produce high-purity creosote diaryl aster used for preparing high-quality and high-purity polycarbonate material. The invention makes the materials get into the ester interchange reaction with a reaction distillation tower. The reaction compound with high boiling point from the bottom of the tower is continuously and orderly passed three specific continuous multistage distillation towers, saying a high boiling point material separating tower A, a creosote dialkyl ester treating tower B and a mid-boiling point material separating tower C, so as to steadily and permanently produce, in the industrial scale of more than 1t per hour, the high-purity creosote dialkyl ester which is taken as a sidedraw naphtha of the treating tower B and does not contain mid and high boiling point off-products substantially.

Description

technical field [0001] The invention relates to an industrial preparation method of high-purity diaryl carbonate. More specifically, the present invention relates to a reaction mixture containing an alkyl aryl carbonate obtained by transesterification of a dialkyl carbonate and an aromatic monohydroxy compound as a raw material, which is subjected to transesterification by means of a reactive distillation column Reaction, the resulting high-boiling reaction mixture containing diaryl carbonate is separated and refined by using three continuous multi-stage distillation towers with a specific structure, thereby industrially preparing polycarbonate raw materials for transesterification Useful process for high purity diaryl carbonates. Background technique [0002] High-purity diaryl carbonates are important raw materials for the preparation of aromatic polycarbonates, which are many engineering plastics most in demand, without the use of toxic phosgene. As a method for produci...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C68/06C08G64/04C07C68/08C07C69/96B01D3/00
CPCB01D3/146B01D3/009C07C68/06C07C68/065C07C68/08C08G64/307Y02P20/10Y02P20/582C07C69/96B01D3/16B01D3/22
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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