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Process for preparing vinyl acetate polymer

A technology for vinyl acetate and polymers, which is applied in the field of preparing vinyl acetate polymers, and can solve the problems of reduced transparency of solutions and volatilized odors, etc.

Inactive Publication Date: 2003-05-28
KURARAY CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, PVA obtained by ordinary methods has some problems, that is, when an aqueous solution is used, insoluble matter in a solvent such as water increases, and the transparency of the solution decreases
In addition, PVA obtained by using persulfates, azo compounds, or organic peroxides as polymerization initiators also has problems in that, for example, when PVA is heated, odor is volatilized.

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0047] In a 10-liter polymerization reactor equipped with a four-bladed paddle stirrer with a condensation coil in the middle, diisopropyl peroxydicarbonate (IPPDC) is used as a polymerization initiator, and lactic acid is used as a hydroxycarboxylic acid, under the following conditions Under continuous polymerization of VAc.

[0048] Amount of VAc 1,000 g / h

[0049] The amount of methanol solution of 0.04% lactic acid 50 g / hour

[0050] The amount of 0.08% IPPDC methanol solution 50 g / hour

[0051] Methanol 150g / h

[0052] Polymerization temperature 60℃

[0053] Average stay time 5 hours

[0054] The obtained polymerization reaction solution is sent to the middle part of the washing tower, and methanol vapor is input at the bottom thereof, and unreacted VAc is washed from the top of the tower to obtain a methanol solution of PVAc.

[0055] Sodium hydroxide was added to the obtained PVAc methanol solution. The solution was saponified at 40° C. and dried...

Embodiment 2-11 and comparative Embodiment 1-7

[0057] PVAc was obtained after polymerizing VAc in the same manner as in Example 1, except that the polymerization initiators and acids in Table 1 or 2 were used. A methanol solution of PVAc is then prepared and saponified to obtain PVA. The evaluation results are listed in Tables 1 and 2.

[0058] implement

[0059] Compare

[0060] Prepare PVAc according to the method of the present invention, reduce the amount of soluble matter in the waste liquid that PVAc saponification produces, reduce the amount of insoluble matter in the solvent that is used to prepare the PVA solution that obtains by PVAc saponification, improve the obtained by PVAc saponification The transparency of the PVA solution reduces the odor of the PVA obtained by saponification of PVAc.

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Abstract

The present invention provides a process of producing a vinyl acetate polymer by homopolymerization of a vinyl acetate monomer or copolymerization of a vinyl acetate monomer and another copolymerizable comonomer, characterized in that a polymerization initiator is an organic peroxide having a half life at 60 DEG C of 10 to 110 minutes, and a polymerization liquid contains at least one carboxylic acid or its salt, said carboxylic acid being selected from the group consisting of a hydroxycarboxylic acid and a polycarboxylic acid.

Description

technical field [0001] The present invention relates to the preparation of vinyl acetate polymers (hereinafter referred to as "PVAc", which may including copolymers). Background technique [0002] Known polymerization methods of VAc include solution polymerization, bulk polymerization, suspension polymerization, emulsion polymerization and the like. [0003] In polymerization, generally persulfates such as potassium persulfate, azo compounds such as azobisisobutyronitrile, and organic peroxides such as benzoyl peroxide can be used as polymerization initiators. [0004] PVAc obtained by polymerizing VAc is converted into polyvinyl alcohol (hereinafter referred to as "PVA", including copolymers) by saponification, and PVA is widely used in industry. [0005] Japanese Laid-Open Patent Heisei 4-213302 (hereinafter referred to as "known item A") discloses a specific organic peroxide used as a polymerization initiator. [0006] Japanese Laid-Open Patent Showa 58-222102 (hereina...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C08F2/00C08F18/08
CPCC08F18/08C08F2/00C08F2/04C08F2/06
Inventor 高地宽吉见一赖
Owner KURARAY CO LTD