Method for preparing polyvinyl chloride by suspension polymerization

Claim 2

The method as claimed in claim 6 wherein said sulfur atom containing compounds are selected from the group consisting of thiocarbonyl radical containing compounds, thioether radical containing compounds and thioalcohols; said oxygen atom containing compounds are selected from the group consisting of quinones, aldehydes, ketones, alcohols having at least six carbon atoms and carboxylic acids having at least six carbon atoms; said anionic and nonionic surface active agents have alkyl radicals containing less than about 18 carbon atoms; said azo dyes are selected from the group consisting of aqueous monoazo dyes, aqueous polyazo dyes, metal-containing azo dyes, naphthol dyes, dispersable azo dyes, fast light yellow G and fast oil yellow G; said anthraquinone dyes are selected from the group consisting of anthraquinone acid dyes, anthraquinone vat dyes, anthrone vat dyes, alizarine dyes, dispersable anthraquinone dyes, IndanthrEne golden yellow RY, Indanthrene gray-X and oil blue-G extra; said indigoid dyes are selected from the group consisting of Brilliant Indigo B, Indanthrene red violet RH and Indanthrene printing black B; said sulfur dyes are selected from the group consisting of sulfur blue F.B.B. and sulfur black B; said phthalocyanine dyes are selected from the group consisting of copper phthalocyanine, metal-free phthalocyanine compounds and phthalocyanine blue; and said azine dyes are selected from the group consisting of aniline black, nigrosin black, oil black and spirit black.

Claim 3

The method as claimed in claim 3 wherein said alizarine dyes are alizarine yellow of alizarine red V2A.

Claim 4

The method as claimed in claim 3 wherein said azo radical containing compounds are selected from the group consisting of azomethane, azobenzene and monoamino nitroso benzene; said nitro radical containing compounds are nitrobenzene; said nitroso radical containing compounds are nitroso benzene or monoaminonitrosobenzene; said azine cyclic compounds are selected from the group consisting of pyrazine, pyridine, thiazine, oxazine, methylene blue, nigrosine black, oil black, and spirit black; said thiocarbonyl radical containing compounds are selected from the group consisting of thiglycolic acid, thiocarbamic acid, thiocarbanil acid, and thiobenzoic acid; said thioether radical containing compound is selected from the group consisting of thiourea and methyl thioether; said thio alcohols are mercaptans having the general formula R-S-R'' wherein R and R'' are alkyl radicals; said quinone compounds are parabenzoquinone; said aldehydes are selected from the group consisting of formaldehyde, acetaldehyde and benzaldehyde; said ketones are acetone; said alcohols are cetyl alcohol or octyl alcohol; and said carboxylic acids are stearic acid.

Claim 5

The method as claimed in claim 1 wherein vinyl chloride monomer is polymerized and at most 100 ppm of said coating compound is added to the polymerization mixture, the monomer, or to the polymerization mixture and the monomer.

Claim 6

The method as claimed in claim 1 wherein an alkali substance is added to the polymerization mixture in an amount such that the pH of the polymerization mixture at the termination of the polymerization will be at least 6.

Claim 7

The method as claim in claim 6 wherein an alkali substance is added to the polymerization mixture in an amount such that the pH of the polymerization mixture at the termination of the polymerization will be at least 6.

Claim 8

The method as claimed in claim 1 further including the step of adding to the polymerization mixture an additive selected from the group consisting of permanganate salts, bichromate salts and ceric sulfate.

Claim 9

The method as claim in claim 6 further including the step of adding to the polymerization mixture an additive selected from the group consisting of permanganate salts, bichromate salts and ceric sulfate.

Claim 10

The method as claimed in claim 7 further including the step of adding to the polymerization mixture an additive selected from the group consisting of permanganate salts, bichromate salts and ceric sulfate.

Claim 11

The method as claimed in claim 8 further including the step of adding to the polymerization mixture an additive selected from the group consisting of permanganate salts, bichromate salts and ceric sulfate.

Claim 12

The method as claimed in claim 1 wherein said suspending agent is a protective colloidal material selected from the group consisting of polyvinyl acetate, partially saponified polyvinyl acetate, polyvinyl alcohol, vinylacetate-maleic anhydride copolymer, styrene-maleic anhydride copolymer, polyacrylic acid, starch, methyl cellulose, hydroxymethyl cellulose, carboxymethyl cellulose, cellulose ether and gelatin or a dispersing agent selected from the group consisting of calcium carbonate, magnesium carbonate, barium sulfate, titanium white and alumina.

Claim 13

The method as claimed in claim 1 wherein said Catalyst is an organic peroxide or an azo compound.

Claim 14

The method as claimed in claim 14 wherein said organic peroxide is an oil-soluble hydroperoxide, lauroyl peroxide, benzoyl peroxide, isopropyl peroxydicarbonate or acetyl cyclohexyl sulfonyl peroxide and said azo compound is azobisisobutylonitrile or dimethylvaleronitrile.

Claim 15

The method as claimed in claim 1 wherein said polymerization is conducted at a temperature of 20*-70* C.

Claim 16

The method as claimed in claim 1 wherein said suspending agent is partially saponified polyvinyl acetate and said alkali substance is added when the polymerization rate is at least several percent.