The B. F. Goodrich Company

Thomas J Doyle

Charles N Bush

Bela K Mikofalvy

Marion G Morningstar

This invention relates to the suspension polymerization of vinyl halides and vinylidene halides in an aqueous medium to make polymers and copolymers which are designed for use in making plastisols. The process is conducted in an aqueous medium using a free-radical yielding catalyst, and in the presence of a hydrolyzed polyvinyl acetate (polyvinyl alcohol) having a degree of hydrolysis in the range of about 65% to about 85% and a compound having a hydrophile-lipophile balance (HLB) less than about 3.5. The important aspect of the present new process is the use of agitation ramping, that is, changing the degree of agitation during the course of the reaction, and adding the catalyst to the reaction medium after the same has reached the reaction temperature whereby these are produced polymer particles which are dense spherical glassy beads having an average diameter in the range of about 10 to about 100 microns. The suspension resins so produced are easily and uniformly mixed with a plasticizer to form plastisols which are stable, containing particles of uniform and proper size, and capable of producing films, and like products, of good clarity.

Suspension polymerization process for making vinyl resins for use in

The present invention relates to a process for producing low energy dispersion vinyl copolymers which, in a plastisol, can be fused at lower temperatures or in a shorter period of time than presently available dispersion vinyl copolymers. It has been found that if, instead of adding all the comonomer batchwise prior to the start of the reaction, the comonomer, such as methyl acrylate, for example, is metered into the reactor continuously, or intermittently, during all or part of the polymerization reaction period, a dispersion vinyl copolymer is produced that has a lower plastisol viscosity for a given comonomer content. Plastisols made from the vinyl copolymers of the present invention have good flow properties and the fused films made therefrom have high gloss, high clarity and good mechanical strength, even when fused at low temperatures.

Process for making dispersion copolymers through monomer metering

There is disclosed a process for preparing vinyl dispersion resins by conducting the polymerization reaction of the vinyl monomer or monomers in an aqueous alkaline medium, using an oil-soluble polymerization initiator, at temperatures preferably below about 48.degree. C., in the presence of an emulsifier system comprising the ammonium salt of a high fatty acid containing from 8 to 20 carbon atoms and at least one long chain alcohol containing from 14 to 24 carbon atoms, wherein the ratio of alcohol to emulsifier is equal to or greater than 1.0 and wherein the reaction ingredients are thoroughly mixed, and preferably homogenized, prior to polymerization. The process produces paste resins having improved heat stability and flow properties and capable of producing films having high clarity and improved water resistance. More importantly, polymer build-up in the reactor is substantially reduced and multiple polymerizations can be run in the reactor without opening the same.

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Lorain, OH, United States of America

Thomas J Doyle