Back to results
US 7,022,745 B2Granted
Process for forming solid pressure sensitive adhesive polymer microspheres
AssigneeSurf Chip, Inc.
InventorsJong-Shing Guo, Augustin T. Chen, Sharon D. Trembley
Life of this patent
Estimating the term…
Abstract
In forming pressure sensitive adhesive microspheres by copolymerizing a non-ionic monomer of an alkyl acrylate or alkyl methacrylate ester of a non-tertiary alcohol and an acid monomer copolymerizable with said non-ionic monomer, an electrolyte is present during the polymerization to promote formation of solid rather than hollow microspheres.
Claims48
A process for preparing solid polymeric pressure sensitive adhesive microspheres comprising:
- (a) contacting a polymerizable aqueous emulsion of at least one non-ionic monomer of an alkyl acrylate or alkyl methacrylate ester of a non-tertiary alcohol and at least one acid monomer copolymerizable with said non-ionic monomer and at least one strong electrolyte selected from alkali metal, alkaline earth metal, or ammonium salts of inorganic or organic acids having a Ka equal to or greater than the Ka of acetic acid,;
- and
- (b) polymerizing the emulsion to form an aqueous suspension of said solid polymeric pressure sensitive adhesive microspheres;
- wherein at least an amount of said strong electrolyte effective to produce polymeric pressure sensitive adhesive solid microspheres is contacted with the polymerizable aqueous emulsion prior to the start of polymerization,
- wherein said process utilizes at least one emulsifier in a concentration greater than the critical micelle concentration;
- and
- wherein said solid polymeric microspheres have improved adhesion performance characteristics.
4 more elements
A process for preparing solid polymeric pressure sensitive adhesive microspheres comprising:
- (a) contacting a polymerizable aqueous emulsion of
- 2-ethylhexyl acrylate and acrylic acid, and a strong electrolyte selected from sodium sulfate or ammonium acetate;
- and
- (b) polymerizing the emulsion to form an aqueous suspension of said solid polymeric pressure sensitive adhesive microspheres;
- wherein at least an amount of said strong electrolyte effective to produce polymeric pressure sensitive adhesive solid microspheres is contacted with the polymerizable aqueous emulsion prior to the start of polymerization, and
- wherein said process utilizes at least one emulsifier in a concentration greater than the critical micelle concentration;
- and
- wherein said solid polymeric microspheres have improved adhesion performance characteristics.
5 more elements
A process for preparing solid polymeric pressure sensitive adhesive microspheres comprising:
- (a) contacting a polymerizable aqueous emulsion of at least one non-ionic monomer of an alkyl acrylate or alkyl methacrylate ester of a non-tertiary alcohol and at least one acid monomer copolymerizable with said non-ionic monomer and at least one strong electrolyte selected from alkali metal, alkaline earth metal, or ammonium salts of inorganic or organic acids having a Ka equal to or greater than the Ka of acetic acid,;
- and
- (b) polymerizing the emulsion to form an aqueous suspension of said solid polymeric pressure sensitive adhesive microspheres;
- wherein an amount of said strong electrolyte ranging from 0.2:1 to 3:1 by weight of the acid monomer (weight of electrolyte to weight of acid monomer) is contacted with the polymerizable aqueous emulsion prior to the start of polymerization to provide the solid polymeric pressure sensitive adhesive microspheres;
- wherein said process utilizes at least one emulsifier in a concentration greater than the critical micelle concentration;
- and
- wherein said solid polymeric microspheres have improved adhesion performance characteristics.
4 more elements
A process for preparing solid polymeric pressure sensitive adhesive microspheres comprising:
- (a) contacting a polymerizable aqueous emulsion of
- 2-ethylhexyl acrylate and acrylic acid, and a strong electrolyte selected from sodium sulfate or ammonium acetate;
- and
- (b) polymerizing the emulsion to form an aqueous suspension of said solid polymeric pressure sensitive adhesive microspheres;
- wherein an amount of said strong electrolyte ranging from 0.2:1 to 3:1 by weight of the acid monomer (weight of strong electrolyte to weight of acid monomer) is contacted with the polymerizable aqueous emulsion prior to the start of polymerization to provide the solid polymeric pressure sensitive adhesive microspheres;
- wherein said process utilizes at least one emulsifier in a concentration greater than the critical micelle concentration;
- and
- wherein said solid polymeric microspheres have improved adhesion performance characteristics.
5 more elements
Dependencies are inferred from the claim text.