Claims
- 1. A process for production of a vinyl chloride polymer comprising polymerizing, by suspension polymerization or emulsion polymerization, vinyl chloride monomer or a mixture of vinyl chloride monomer with a vinyl monomer copolymerizable with said vinyl chloride monomer in an aqueous medium in a polymerizer, wherein the inner wall surface of the polymerizer and portions of the auxiliary equipment thereof which come into contact with the monomer during polymerization have been previously coated with a scaling preventive coating comprising at least one component selected from dyes and pigments, and the chloride ion concentration in the reaction mixture is controlled to not higher than 100 ppm during the polymerization.
- 2. A process according to claim 1, wherein said scaling preventive coating comprises at least one component selected from azo dyes and pigments, anthraquinone dyes and pigments, indigoid dyes and pigments, phthalocyanine dyes and pigments, carbonium dyes and pigments, quinoneimine dyes, methine dyes, quinoline dyes, nitro dyes, benzoquinone and naphthoquinone dyes, naphthalimide dyes and pigments, perinone dyes, sulfide dyes, fluorescent dyes, and azoic dyes.
- 3. A process according to claim 2, wherein said scaling preventive coating comprises an azine dye.
- 4. A process according to claim 1, wherein said scaling preventive coating further comprises an inorganic compound.
- 5. A process according to claim 4, wherein said inorganic compound is selected from silicic acids; silicates; salts of magnesium, calcium, barium, zinc, aluminum, tin, iron, nickel, cobalt, chromium, molybdenum, manganese, copper, silver and platinum; and inorganic colloids.
- 6. A process according to claim 5, wherein said inorganic compound is a silicate, silicic acid colloid or ferric hydroxide colloid.
- 7. A process according to claim 4, wherein said scaling preventive coating comprises at least one component selected from azo dyes and pigments, anthraquinone dyes and pigments, indigoid dyes and pigments, phthalocyanine dyes and pigments, carbonium dyes and pigments, quinoneimine dyes, methine dyes, quinoline dyes, nitro dyes, benzoquinone and naphthoquinone dyes, naphthalimide dyes and pigments, perinone dyes, sulfide dyes, fluorescent dyes, and azoic dyes.
- 8. A process according to claim 7, wherein said scaling preventive coating comprises an azine dye.
- 9. A process according to claim 1, wherein a fixing agent is used for enchancement of the fixing characteristic of said scaling preventive coating.
- 10. A process according to claim 9, wherein said fixing agent is at least one selected from olefin polymers, diene polymers, acetylene polymers, aliphatic vinyl or vinylidene polymers, aromatic vinyl polymers, heterocyclic vinyl polymers, acrylic or methacrylic polymers, polyethers, polysulfides, polysulfones, poly(alkylene diisocyanate), poly(5-iminohydantoin), poly(perfluoroglutaronitrile), poly(1-perfluorobutyrylaziridine), polyesters, polyamides, polyureas, polyurethanes, linear condensed poplymers, heterocyclic condensed polymers, natural polymers, modified natural polymers, polysiloxanes, organic metal polymers and inorganic polymers.
- 11. A process according to claim 1, wherein portions of a recovery system for unreacted monomers where scales may stick are previously coated with the scaling preventive coating.
- 12. A process according to claim 1, wherein the inner wall surface of the polymerizer and the portions of the auxiliary equipment contacting the monomer have a surface roughness of 10 .mu.m or less.
Priority Claims (2)
Number |
Date |
Country |
Kind |
59-152522 |
Jul 1984 |
JPX |
|
59-155967 |
Jul 1984 |
JPX |
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Parent Case Info
This is a continuation of application Ser. No. 756,313, filed July 18, 1985 and now abandoned.
US Referenced Citations (7)
Foreign Referenced Citations (5)
Number |
Date |
Country |
0008799 |
Mar 1980 |
EPX |
121263 |
Oct 1984 |
EPX |
126991 |
Dec 1984 |
EPX |
1291145 |
Sep 1972 |
GBX |
1365590 |
Sep 1974 |
GBX |
Non-Patent Literature Citations (1)
Entry |
Preparation and Properties of Polyvinyl Chloride, Zilberman et al., Chimija, 1968, pp. 24-29--WPS-1 USSR. |
Continuations (1)
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Number |
Date |
Country |
Parent |
756313 |
Jul 1985 |
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