Claims
- 1. A process for the preparation of a monodisperse particle latex of a vinyl chloride polymer, comprising aqueousemulsion polymerizing, in one or two stages, vinyl chloride monomer in the absence of surface-active agent in the first stage, in the presence of at least 0.2% by weight of at least one water-soluble alkali metal or ammonium persulfate initiator, and also in the presence of at least one water-soluble auxiliary compound that is a solvent for vinyl chloride, said solvent not being capable of copolymerizing with said vinyl chloride monomer, in such amount that the solubility of vinyl chloride in the aqueous phase at 25.degree. C. at atmospheric pressure is at least 1.5 g/l, and wherein said monodisperse particle latex is substantially free of non-spherical particles.
- 2. The process as defined by claim 1, comprising a single stage of aqueous emulsion polymerization.
- 3. The process as defined by claim 1, wherein said auxiliary compound comprises an alcohol or ketone having from 1 to 16 carbon atoms.
- 4. The process as defined by claim 3, wherein said auxiliary compound is methyl alcohol, ethyl alcohol, butyl alcohol, dimethyl ketone or methyl ethyl ketone.
- 5. The process as defined in claim 1, wherein the proportion of said auxiliary compound ranges from 1 to 100% by weight relative to the vinyl chloride monomers.
- 6. The process as defined by claim 1, wherein the monomer content of the reaction mixture ranges from 1 to 50% at the start of said stage.
- 7. The process as defined in claim 1, comprising two stages of aqueous emulsion polymerization, and wherein the second stage is carried out in the presence of a seed material which comprise at least a part of the latex emanating from the first stage.
- 8. The process as defined by claim 7, wherein the amount of seed material is such that the quantity of polymer contained therein constitutes from 0.3 to 30% by weight of the total amount of polymer plus monomer.
- 9. The process as defined by claim 7, wherein the quantity of water employed in carrying out the second stage is such that the initial content of seed material plus monomer constitutes from 1 to 45% by weight relative to the reaction mixture.
- 10. The process as defined by claim 7, wherein the second stage is carried out in the presence of a water-soluble initiator.
- 11. The process as defined by claim 10 wherein said second stage is carried out in the presence of a water-soluble initiator, a reducing agent and an anionic emulsifier.
- 12. The process as defined by claim 11, said second stage being carried out in the presence of a non-ionic emulsifier.
- 13. A process for the preparation of a monodisperse particle latex of a vinyl chloride polymer, comprising aqueous emulsion polymerizing, in one or two stages, vinyl chloride monomer in the absence of surface-active agent in the first stage, in the presence of at least 0.2% by weight of at least one water-soluble alkali metal or ammonium persulfate initiator, and also in the presence of at least one water-soluble auxiliary compound that is a solvent for vinyl chloride, said solvent not being capable of copolymerizing with said vinyl chloride monomer, in such amount that the solubility of vinyl chloride in the aqueous phase at 25.degree. C. at atmospheric pressure is at least 1.5 g/l, and wherein said monodisperse particle latex contains particles having an average diameter from 0.5 to 1.2 .mu.m.
Priority Claims (1)
Number |
Date |
Country |
Kind |
87 05260 |
Apr 1987 |
FRX |
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Parent Case Info
This application is a continuation, of application Ser. No. 07/180,837, filed Apr. 12, 1988, now abandoned.
US Referenced Citations (7)
Foreign Referenced Citations (3)
Number |
Date |
Country |
889980 |
Sep 1949 |
DEX |
699016 |
Oct 1953 |
GBX |
991536 |
May 1965 |
GBX |
Continuations (1)
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Number |
Date |
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Parent |
180837 |
Apr 1988 |
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