Polyvinylacetal resin and process for producing the same

Details Polyvinylacetal resin and process for producing the same Polyvinylacetal resin and process for producing the same

2008-06-10

2008-06-10

Choi, Ling-Sui (Department: 1796)

Synthetic resins or natural rubbers -- part of the class 520 ser

Synthetic resins

Mixing of two or more solid polymers; mixing of solid...

C525S056000, C526S202000

Reexamination Certificate

active

07385005

ABSTRACT:
A polyvinylacetal resin powder with a low metal content, being excellent in transparency, moisture resistance and electrical insulating properties and having a large specific surface area, and a process for its production, are presented. A polyvinylacetal resin powder obtained by reacting polyvinyl alcohol and an aldehyde in the presence of an acid catalyst, which has an acetalization degree of at least 60 mol %, a specific surface area of from 1.50 to 3.50 m2/g, a bulk density of from 0.12 to 0.19 g/cm3, an average particle diameter of from 0.5 to 2, 5 μm and a metal content of at most 80 ppm.It is produced, for example, by feeding a reaction fluid containing polyvinyl alcohol, an aldehyde and an acid catalyst into a first reactor, to carry out an acetalization reaction, discharging the reaction fluid wherein the acetalization degree has reached from 10 to 60 mol %, and feeding the same into a second reactor to carry out a further reaction to bring the acetalization degree of polyvinylacetal to at least 65 mol %.

REFERENCES:
patent: 32 46 605 (1984-06-01), None
patent: 196 17 893 (1997-10-01), None
patent: 0 513 857 (1992-11-01), None
patent: 1 447 520 (1976-08-01), None
patent: 63301208 (1988-12-01), None
patent: 4-55404 (1992-02-01), None
patent: 4-275310 (1992-09-01), None
patent: 5-1108 (1993-01-01), None
patent: 5-59117 (1993-03-01), None
patent: 05059117 (1993-03-01), None
patent: 5-97918 (1993-04-01), None
patent: 5-97919 (1993-04-01), None
patent: 05097918 (1993-04-01), None
patent: 5-140216 (1993-06-01), None
patent: 11-349629 (1999-12-01), None
patent: 2000-38456 (2000-02-01), None
patent: 2000038456 (2000-02-01), None
patent: 2000-336117 (2000-12-01), None
patent: 2000336117 (2000-12-01), None
patent: WO 94/13710 (1994-06-01), None
Patent Abstracts of Japan, JP 05-059117, Mar. 9, 1993 (reference previously filed in Japanese language on Aug. 9, 2004).
Derwent Publications, AN 1983-21176, XP-002320217, JP 58-011046, Jan. 21, 1983.

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