Internally plasticized polymer latex
AssigneeRohm and Haas Company
InventorsDavid R. Gehman, Joseph M. Owens, Richard E. Zdanowski
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Abstract
This invention relates to a latex of internally plasticized polymer particles, low in viscosity although high in hydrophilic components and film forming at temperatures below the calculated Tg of the polymer. The polymer may be prepared by a multistage emulsion polymerization process. The first stage is highly water-swellable or water-soluble. The principal second or later stage is less hydrophilic and of higher Tg than the first stage and is polymerized in the emulsion in the presence of the first stage.
Claims29
A latex of internally plasticized addition polymer particles, having a calculated Tg above about 20.degree. C., comprising:
- (A) a first stage polymer comprising at least 10% hydrophilic mer units comprising 0.5 to 90% acid or base units, in the unneutralized or neutralized form, and about 99.5% to 10% nonionic hydrophilic units and (B) a later stage, less hydrophilic, polymer polymerized in the presence of an emulsion of the first stage polymer, wherein the first and later stage polymers are each at least about 20% of the addition polymer, by weight;
- the latex having (1) a viscosity below about 5,000 centipoises, at 20% solids over the pH range 4 to 10, and (2) a minimum film temperature more than 5.degree. C. below the calculated Tg of the addition polymer.
A latex of internally plasticized addition polymer particles comprising:
- (A) a first stage polymer, polymerized from a monomer mix consisting essentially of monoethylenically unsaturated monomers, comprising, by weight, at least 10% hydrophilic mers, the hydrophilic mers comprising at least 10% nonionic and at least 0.5% ionic mers, and
- (B) a less hydrophilic, higher Tg, later stage polymer polymerized in the presence of an emulsion of the first stage polymer;
- (A) being from 20% to 80% of the combined weight of (A) and (B);
- the interpenetration parameter of (A) being greater than that of (B) by up to eight units.
A process, for producing a latex of internally plasticized addition polymer particles, comprising:
- (a) polymerizing a first stage polymer comprising at least 10% hydrophilic mer units comprising nonionic hydrophilic units and
- (b) in the presence of an emulsion of the first stage polymer polymerizing a later stage less hydrophilic polymer wherein the first and later stage polymers are each at least about 20% of the addition polymer, by weight, to produce a latex having (1) a viscosity below about 5,000 centipoises at 20% solids and over the pH range 4 to 10, and (2) a minimum film temperature more than 5.degree. C. below the calculated Tg of the addition polymer;
- the addition polymer having a calculated Tg above about 20.degree. C.
A process, for producing a latex of internally plasticized addition polymer particles, comprising
- (a) producing a first stage polymer, polymerized from a monomer mix consisting essentially of monoethylenically unsaturated monomers, comprising at least 10% by weight hydrophilic mers, the hydrophilic mers comprising at least 10% by weight nonionic mers and at least 0.5% by weight ionic mers and
- (b) polymerizing, in the presence of an emulsion of the first stage polymer, a later stage polymer less hydrophilic, having an interpenetration parameter higher by up to eight units, and a higher Tg than the first stage polymer, the first stage polymer being from 20 to 80% by weight of the total first and later stage polymers.
Dependencies are inferred from the claim text.