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US 4,094,848 AGranted
Process for producing finely divided porous polymer particles
AssigneeFuji Photo Film Co., Ltd.
InventorKenji Naito
Life of this patent
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Abstract
A process for producing finely divided polymer particles which is characterized by using a water drop containing polymer emulsion which is produced by a process comprising dissolving a copolymer containing about 10 to about 70 mol% of a carboxyl group containing vinyl compound in a solvent mixture consisting of about 20 to about 90 weight% of sec-butanol or tert-butanol and about 10 to about 80% by weight of another hydrophobic organic solvent and dispersing the resultant solution in an aqueous medium.
Claims12
A process for producing finely divided porous polymer particles comprising:
- (1) forming a solution by dissolving a copolymer in a solvent mixture
- (a) said copolymer comprising as one comonomer component of said copolymer, from about 10 to about 70 mol % of a vinyl compound which contains a carboxyl group,
- (b) said solvent mixture comprising
- (i) from about 20 to about 90% by weight of a solvent selected from the group consisting of sec-butanol, tert-butanol or mixtures thereof, and
- (ii) from about 10 to about 80% by weight of a hydrophobic organic solvent,
- (2) forming a water drop containing polymer emulsion by dispersing said solution in an aqueous medium in the presence of at least one emulsion stabilizer or surface active agent, and
- (3) recovering said finely divided porous polymer particles from said emulsion.
4 more elements
Dependencies are inferred from the claim text.