Claims
- 1. A polymer scale preventive agent for use in polymerization of vinyl chloride monomer or a monomer mixture containing vinyl chloride monomer as a major component, comprising:
- (A) a naphthoquinone natural dye selected from the group consisting of naphthazarines and
- (B) a polyvinyl alcohol with a saponification degree of at least 50 mol % wherein the component (B) essentially consists of (B-1) a polyvinyl alcohol with a saponification degree of at least 95 mol % and (B-2) a polyvinyl alcohol with a saponification degree of at least 70 mol % but not more than 95 mol %, wherein the weight ratio of component (B-1)/component (B-2) is in the range of 1/50 to 50/1.
- 2. The agent of claim 1, wherein the component (B) comprises a polyvinyl alcohol with a saponification degree of at least 95 mol %.
- 3. The agent of claim 1, wherein the polyvinyl alcohol of the component (B) has a polymerization degree of 300 to 8,000.
- 4. The agent of claim 1, wherein the component (B) is contained in an amount of 0.1 to 10,000 parts by weight per 100 parts by weight of the component (A).
- 5. The agent of claim 1 which further comprises a solvent and is in a state of a solution or a dispersion.
- 6. The agent of claim 5, wherein the total concentration of the components (A) and (B) is in the range of 0.001 to 20% by weight.
- 7. The agent of claim 1, wherein component (A) comprises at least one compound selected from the group consisting of naphthazarin, 2,3-dihydroxynaphthazarin, 2-methylnaphthazarin, 2-hydroxynaphthazarin, 2-hydroxy-3-methylnaphthazarin, 2-hydroxy-3-ethylnapthazarin, 2-hydroxy-3-acetylnaphthazarin and 2,7-dimethylnaphthazarin.
Priority Claims (3)
Number |
Date |
Country |
Kind |
2-225525 |
Aug 1990 |
JPX |
|
2-225526 |
Aug 1990 |
JPX |
|
2-225527 |
Aug 1990 |
JPX |
|
Parent Case Info
This application is a continuation of application Ser. No. 07/750,619, filed on Aug. 27, 1991, now abandoned.
US Referenced Citations (5)
Foreign Referenced Citations (3)
Number |
Date |
Country |
91965 |
Oct 1983 |
EPX |
126991 |
Dec 1984 |
EPX |
320227 |
Jun 1989 |
EPX |
Continuations (1)
|
Number |
Date |
Country |
Parent |
750619 |
Aug 1991 |
|