Unlock instant, AI-driven research and patent intelligence for your innovation.

Dispersion stabilizer for suspension polymerization and method for producing vinyl resin

a technology of suspension polymerization and stabilizer, which is applied in the direction of transportation and packaging, mixing, chemistry apparatus and processes, etc., can solve the problems of not fully satisfying the above required performance, and achieve the effects of improving bulk density, excellent polymerization stability, and small particle siz

Active Publication Date: 2017-11-23
KURARAY CO LTD
View PDF4 Cites 2 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Benefits of technology

The present invention provides a dispersion stabilizer for suspension polymerization of vinyl-based monomers that produces a vinyl-based resin with good stability and particle size. The dispersion stabilizer contains a vinyl alcohol-based polymer (A) with specific properties including low absorbance, high degree of saponification, high viscosity-average degree of polymerization, and a YI value. The polymer (A) has to have a degree of saponification of not less than 68 mol % and not more than 98 mol % for optimal performance. The dispersion stabilizer helps to improve the polymerization stability, particle size, and bulk density of the vinyl-based resin.

Problems solved by technology

Since it is difficult to satisfy the above performances with a general partially saponified PVA, various attempts have been made.
Although the performances of the dispersion stabilizer are improved by the heat treatment compared with conventional products, they do not fully satisfy the above required performances.

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Examples

Experimental program
Comparison scheme
Effect test

example 1

[0051]In a 5 liter autoclave, 100 parts of a deionized aqueous solution in which PVA (A1) was dissolved in an amount of 880 ppm relative to vinyl chloride were charged, and deionized water was additionally charged to have 1200 parts of deionized water in total. Then, 0.65 parts of a 70% solution of cumyl peroxyneodecanoate in toluene and 1.05 parts of a 70% solution of t-butyl peroxyneododecanoate in toluene were charged in the autoclave. An operation in which nitrogen was introduced into the autoclave to produce a pressure of 0.2 MPa and then the nitrogen was purged was repeated 5 times in total. Inside the autoclave was thus sufficiently purged with nitrogen to remove oxygen, followed by charging of 940 parts of vinyl chloride. The contents in the autoclave were raised in temperature to 57° C. to initiate polymerization of the vinyl chloride monomer with stirring. The pressure in the autoclave was 0.80 MPa at the beginning of the polymerization. Approximately 3.5 hours after the i...

example 2

[0064]Suspension polymerization of vinyl chloride was carried out in the same manner as that in Example 1 other than using a deionized aqueous solution in which PVA (A1) (240 ppm based on vinyl chloride) and PVA (B1) (640 ppm based on vinyl chloride) were dissolved, instead of the deionized aqueous solution of PVA (A1), to produce vinyl chloride resin particles. Evaluation results of the vinyl chloride resin particles are shown in Table 2.

examples 3-14

[0065]Suspension polymerization of vinyl chloride was carried out in the same manner as that in Example 2 other than changing the type and amount of the PVA (A) and the PVA (B) to be used as shown in Table 1 to produce vinyl chloride resin particles. Evaluation results of the vinyl chloride resin particles are shown in Table 2.

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

PropertyMeasurementUnit
wavelengthaaaaaaaaaa
wavelengthaaaaaaaaaa
yellow indexaaaaaaaaaa
Login to View More

Abstract

A dispersion stabilizer for suspension polymerization is provided that includes a vinyl alcohol-based polymer (A), wherein a 0.1 mass % concentration aqueous solution of the polymer (A) has an absorbance (a1) of less than 0.25 at a wavelength of 280 nm, the aqueous solution has an absorbance (a2) of less than 0.030 at a wavelength of 320 nm, the polymer (A) has a degree of saponification of not less than 68 mol % and not more than 98 mol %, the polymer (A) has a viscosity-average degree of polymerization of more than 1500 and less than 4500, and the polymer (A) in powder form has a YI value of not less than 5. The dispersion stabilizer is capable of producing a vinyl-based resin that is excellent in polymerization stability, has a small particle size, and has an improved bulk density.

Description

TECHNICAL FIELD[0001]The present invention relates to a dispersion stabilizer for suspension polymerization containing a vinyl alcohol-based polymer. The present invention also relates to a method of producing a vinyl-based resin in which a vinyl-based monomer is suspension-polymerized using the dispersion stabilizer.BACKGROUND ART[0002]For industrial production of a vinyl-based polymer, such as a vinyl chloride resin, suspension polymerization is widely applied in which a vinyl-based monomer, such as vinyl chloride, is dispersed in an aqueous medium using a dispersion stabilizer to be polymerized in the presence of an oil-soluble catalyst. In general, factors to control the quality of a vinyl-based polymer include a rate of polymerization, a polymerization temperature, a type and an amount of a catalyst, a model of a polymerization vessel, a stirring rate, a type of a dispersing agent, and the like. Among all, the type of a dispersing agent has a significant influence. For suspensi...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & Authority Applications(United States)
IPC IPC(8): C08F116/06C08F114/06C08L29/04C08F2/20C08F8/12C08F18/08C09K23/52
CPCC08F8/12C08F18/08C08F2/20C08L2205/025C08L29/04C08F114/06C08F116/06C08F14/06C08F216/06C08F8/00C08F2/30C09K23/018C09K23/38C08F118/08C08F218/08
Inventor FUKUHARA, TADAHITO
Owner KURARAY CO LTD