Dispersion stabilizer for suspension polymerization of vinyl...

Plastic and nonmetallic article shaping or treating: processes – Miscellaneous

Reexamination Certificate

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C524S557000

Reexamination Certificate

active

07070731

ABSTRACT:
The present invention provides a new dispersion stabilizer that satisfies, at a high level, the performances required for a dispersion stabilizer used for suspension polymerization. A method of producing a dispersion stabilizer that is useable for suspension polymerization of a vinyl compound and contains a vinyl alcohol polymer (A) includes producing the vinyl alcohol polymer (A) by heat-treating a vinyl alcohol polymer (B) at a temperature of 90 to 180° C. for 0.5 to 20 hours in an atmosphere in which an oxygen concentration is 8000 ppm or lower. The vinyl alcohol polymer (B) has a saponification degree of at least 60 mol % and contains a residual acetic acid group whose block character is in the range of 0.3 to 0.6.

REFERENCES:
patent: 5308911 (1994-05-01), Takada et al.
patent: 5334575 (1994-08-01), Noonan et al.
patent: 5717044 (1998-02-01), Takada
patent: 5780547 (1998-07-01), Saeki et al.
patent: 5977273 (1999-11-01), Saeki et al.
patent: 6451898 (2002-09-01), Tanimoto et al.
patent: 6485842 (2002-11-01), Shindome et al.
patent: 6495623 (2002-12-01), Tanimoto et al.
patent: 6635709 (2003-10-01), Kato et al.
patent: 30 48 687 (1982-07-01), None
patent: 1152032 (2001-11-01), None
patent: 653239 (1951-05-01), None
patent: 61-108602 (1986-05-01), None
patent: 5-105702 (1993-04-01), None
patent: 5-88251 (1993-12-01), None
patent: 8-208724 (1996-08-01), None
patent: 2002-30104 (2002-01-01), None
patent: 2002-97208 (2002-04-01), None
K. Nagano, et al., Koubunshi Kankoukai, pp. 246-249 and pp. 411-415, “POVAL”, 1984.
T. Moritani et al. Macromolecuels, vol. 10, No. 3, pp. 532-535, “13C-and 1H-NMR Investigations of Sequences Distribution in Vinyl Alcohol-Vinyl Acetate Copolymers”, May-Jun. 1977.

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