US 4,786,696 AGranted

Process for the preparation of tacky polymeric microspheres

AssigneeMinnesota Mining and Manufacturing Company

InventorBernd Bohnel

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Abstract

A process for the preparation of infusible, solvent-insoluble, solvent-dispersible, inherently tacky elastomeric polymeric microspheres without the use of a suspension stabilizer comprising the steps of: (a) charging to a reaction vessel: (1) at least one alkyl acrylate or methacrylate ester monomer; (2) at least one emulsifier at a concentration above its critical micelle concentration; and (3) an effective amount of at least one substantially water insoluble polymerization initiator; (b) agitating the reaction vessel charge prior to the initiation of the reaction sufficient to create a suitable monomer/water emulsion in the reaction vessel; and (c) maintaining the agitation for a time sufficient to allow substantially complete conversion of the monomer. This process forms elastomeric, solvet-dispersible, polymeric micropheres.

Claims18

Dependent claims

(a) concocting a reaction mixture by charging to a reaction vessel
(i) one or more alkyl acrylate or methacrylate ester monomers or mixtures thereof
(ii) at least one emulsifier at a concentration above its critical micelle concentration;
and
(iii) an effective amount of at least one substantially water insoluble polymerization initiator;
(b) agitating said reaction mixture sufficient to create a suspension of monomer droplets having an average monomer droplet size in the range of between about 5 microns and about 70 microns prior to the initiation of a reaction therein;
(c) initiating a reaction in said reaction vessel;
and
(d) maintaining said agitation for a time sufficient to allow substantially complete conversion of said monomer;
whereby elastomeric, solvent-dispersible, polymeric microspheres are formed.

7 more elements

Dependencies are inferred from the claim text.