Tacky polymeric microspheres
AssigneeMinnesota Mining and Manufacturing Company
InventorsWilliam A. Baker, Warren D. Ketola
Life of this patent
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Abstract
Infusible, solvent-insoluble, solvent-dispersible, inherently tacky, elastomeric polymeric microspheres which are formed from non-ionic monomers and comprise at least one oleophilic water-emulsifiable alkyl acrylate or methacrylate ester, and a suspension polymerization technique for producing the microspheres, which includes the use of an ionic suspension stabilizer.
Claims10
Infusible, solvent-insoluble, solvent-dispersible, inherently tacky, elastomeric polymeric microspheres formed from non-ionic monomers and comprising a major portion of at least one oleophilic, water-emulsifiable alkyl acrylate or methacrylate ester, said polymeric microspheres having a glass transition temperature below about -20.degree. C., and having been prepared by aqueous suspension polymerization in the presence of at least one anionic emulsifier at a concentration level above said emulsifier's critical micelle concentration and an ionic suspension stabilizer having an interfacial tension of at least about 15.0 dynes per centimeter.
An article comprising a substrate having disposed on at least one surface thereon infusible, solvent-insoluble, solvent-dispersible, inherently tacky, elastomeric polymeric microspheres formed from non-ionic monomers and comprising a major portion of at least one oleophilic, water-emulsifiable alkyl acrylate or methacrylate ester, said polymeric microspheres having a glass transition temperature below about -20.degree. C., and having been prepared by aqueous suspension polymerization in the presence of at least one anionic emulsifier at a concentration level above said emulsifier's critical micelle concentration and an ionic suspension stabilizer having an interfacial tension of at least about 15.0 dynes per centimeter.
A suspension polymerization process for preparing infusible, solvent-insoluble, solvent-dispersible, inherently tacky, elastomeric polymeric microspheres comprising the steps of:
- (a) charging to a reaction vessel
- (i) at least one alkyl acrylate or methacrylate ester monomer;
- and
- (ii) at least one anionic emulsifier at a concentration above its critical micelle concentration;
- and
- (iii) a substantially water-insoluble polymerization initiator;
- and
- (iv) an ionic suspension stabilizer, having an interfacial tension of at least about 15.0 dynes per centimeter;
- (b) agitating the reaction vessel charge to create an emulsion;
- (c) heating said emulsion while maintaining said agitation;
- whereby elastomeric, solvent-dispersible polymeric microspheres are formed from said emulsion.
Dependencies are inferred from the claim text.