Claims
- 1. An agitated aqueous suspension process for producing porous, substantially skinless, agglomerated polyvinyl chloride resin particles comprising polymerizing vinyl monomer in the presence of a dispersant system comprising (a) from about 0.02 to about 0.06 part by weight per 100 parts by weight monomer of an ion sensitive primary dispersant capable of thickening water; (b) from about 0.2 to about 0.4 part by weight of non-polyethylene oxide containing secondary dispersant; and (c) from about 0.1 to about 0.3 part by weight per 100 parts by weight vinyl monomer of a polyvinyl acetate secondary dispersant having a hydrolysis level less than 70%, said resin particles having a mercury porosity of from about 0.1 cc/g to about 0.7 cc/g, and a particle size of from about 70 microns to about 1000 microns, and a friability of less than about 2, and a powder mix time of less than about 400 seconds, and a shape factor less than about 0.85 and wherein greater than about 20% of the area of the surface of said particle is PVC as measured by ESCA.
- 2. A process of claim 1 wherein said non-polyethylene oxide containing dispersant is selected from the group consisting of sorbitan trioleate, sorbitan tristearate, sorbitan monooleate, sorbitan monopalmitate, glycerol monooleate, glycerol monostearate, and triglycerol monooleate.
- 3. A process of claim 2 wherein said primary dispersant is a lightly crosslinked interpolymer of acrylic acid.
- 4. A process of claim 3 wherein said polyvinyl acetate secondary dispersant has a hydrolysis level less than 55%.
- 5. A process of claim 4 wherein said vinyl monomer is vinyl chloride.
Parent Case Info
This is a division of application Ser. No. 038,099, filed Apr. 14, 1987, now U.S. Pat. No. 4,711,908, issued Dec. 8, 1987.
US Referenced Citations (5)
Divisions (1)
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Number |
Date |
Country |
Parent |
38099 |
Apr 1987 |
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