Claims
- 1. A method of preventing polymer scale formation in a polymerization vessel during the polymerization of a monomer having an ethylenic double bond, wherein said polymerization is carried out in a polymerization vessel in which its inner wall surface has been previously coated with a coating solution consisting of (A) at least one member selected from the group consisting of C.I. Acid Black 1, C.I. Acid Black 2, C.I. Acid Black 124, C.I. Direct Blue 1, C.I. Direct Blue 6, C.I. Direct Blue 71, C.I. Direct Black 2, C.I. Direct Black 19, C.I. Direct Black 32, C.I. Direct Black 38, C.I. Direct Black 77, C.I. Acid Blue 1, C.I. Acid Blue 2, C.I. Acid Blue 40, C.I. Acid Blue 59, and alkali metal salts and ammonium salts of a sulfonated product obtained by sulfonation of a condensate of an aromatic amine compound having the general formula (I): ##STR3## wherein R.sup.1 represents a hydrogen atom, --HN.sub.2, --N.dbd.N--C.sub.6 H.sub.5, --NH--C.sub.6 H.sub.5 or --NH--C.sub.6 H.sub.4 --NH.sub.2, and R.sup.2 represents a hydrogen atom or --NH.sub.2, with an aromatic nitro compound having the general formula (II) ##STR4## wherein R.sup.3 represents a hydrogen atom or --NH.sub.2, (B) at least one member selected from the group consisting of C.I. Solvent Black 3, C.I. Solvent Black 5, C.I. Solvent Black 7, C.I. Solvent Black 22, C.I. Basic Black 2, C.I. Basic Orange 2, C.I. Basic Orange 14, C.I. Solvent Blue 2, C.I. Solvent Blue 11, C.I. Solvent Blue 12, C.I. Solvent Blue 25, C.I. Solvent Blue 35 and C.I. Solvent Blue 36, and one or more solvents and pH adjusters with the solution having a pH of more than 7, and then dried to form a coating.
- 2. The method according to claim 1, wherein said component (A) is C.I. Acid Black 1, C.I. Acid Black 2, C.I. Acid Black 124, or said alkali metal salt or ammonium salt of the sulfonation product.
- 3. The method according to claim 1, wherein said component (B) is C.I. Solvent Black 3, C.I. Solvent Black 5, C.I. Solvent Black 7, or C.I. Solvent Black 22.
- 4. The method according to claim 1, wherein said coating solution has a pH of from 8 to 11.
- 5. The method according to claim 1, wherein the pH of said coating solution is adjusted with ethylenediamine.
- 6. The method according to claim 1, wherein the weight ratio of the component (A)/the component (B) in said coating solution ranges from 100/0.1 to 100/1,000.
- 7. The method according to claim 1, wherein said coating solution contains said component (A) and said component (B) in a total concentration of from 0.01 to 5% by weight.
- 8. The method according to claim 1, wherein said coating solution has been previously applied to parts of the polymerization vessel with which the monomer comes into contact during polymerization other than its inner wall surface and then dried to form a coating.
- 9. The method according to claim 8, wherein said parts with which the monomer comes into contact are selected from the group consisting of a stirring shaft, stirring blade, baffle, header, search coil and condenser.
- 10. The method according to claim 1, wherein said coating solution has been further previously applied to parts of the recovery system of an unreacted monomer with which the monomer comes into contact and then dried to form a coating.
- 11. The method according to claim 1, wherein the coating formed has a coating weight of from 0.001 to 5 g/m.sup.2.
- 12. The method according to claim 1, wherein the monomer is at least one member selected from the group consisting of vinyl halides; vinyl esters; acrylic acid and methacrylic acid, or salts of these; maleic acid or fumaric acid, and esters or anhydrides thereof; diene monomers; aromatic vinyl compounds; acrylates; acrylonitrile; halogenated vinylidenes; and vinyl ethers.
- 13. The method according to claim 1, wherein said polymerization is carried out as suspension polymerization, emulsion polymerization, solution polymerization or bulk polymerization.
Priority Claims (1)
Number |
Date |
Country |
Kind |
1-207185 |
Aug 1988 |
JPX |
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Parent Case Info
This application is a continuation of application Ser. No. 07/395,584, filed on Aug. 18, 1989, now abandoned.
US Referenced Citations (1)
Number |
Name |
Date |
Kind |
4068059 |
Whitenhafer |
Jan 1978 |
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Foreign Referenced Citations (1)
Number |
Date |
Country |
0096319 |
Dec 1983 |
EPX |
Continuations (1)
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Number |
Date |
Country |
Parent |
395584 |
Aug 1989 |
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