Method of preparing a low density, nonflammable polyvinyl foam composition
AssigneeHirosuke Kojima
InventorsTakayuki Otsu, Hirosuke Kojima
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Abstract
A method of preparing a foamable polyvinyl system resin composition which renders a non-flammable, high strength to weight ratio foam product comprises, reacting at least 0.05 parts by weight of an organic radical initiator per 1 part by weight of polyvinyl system resin with the components consisting essentially of (a) at least one polyvinyl system resin (b) 2-100 parts by weight of at least one inorganic filler per 1 part by weight of polyvinyl system resin (c) an effective amount of at least one blowing agent.
Claims3
A method of preparing a foamable polyvinyl resin composition suitable for forming nonflammable foamed products having compressive strengths greater than 10 kg/cm.sup.2 and densities less than 100 kg/m.sup.3, said method comprising the step of reacting (a) polyvinyl chloride resin;
- (b) at least 0.05 parts by weight organic initiator per 1 part by weight of polyvinyl chloride resin, said organic initiator being selected from the group consisting of azobisalkylnitrile, azobiscyclohexylcarbonitrile, azobisester, phenylazotriphenylmethane, phenylazothiophenylether, phenylazophenylamine, azobisbenzoyl, tetraalkylterazane, 4,4'-azobis-4-cyano valeric acid, dibenzothiazoledisulfide, metal compound of 2-mercapto benzothiazole, N-cyclohexyl-2-benzothiazolysulphenamide, tetraalkylthiuramdisulfide, and metal derivatives of dialkyldithiocarbamic acid;
- (c) 2-100 parts by weight of at least one inorganic filler per 1 part by weight of polyvinyl chloride resin;
- and (d) an effective amount of at least one blowing agent.
A process for making a vinyl chloride polymer foam suitable for forming nonflammable foamed products having compressive strengths greater than 10 kg/cm.sup.2 and densities less than 100 kg/cm.sup.3, said process comprising the steps of:
- (1) preparing a composition consisting of:
- (a) a vinyl chloride polymer selected from the group consisting of polyvinyl chloride, polyvinylidene chloride, copolymers of polyvinyl chloride, chlorinated polyethylene;
- (b) 2-100 parts per 1 part of vinyl chloride polymer of at least one inorganic filler;
- (c) a blowing agent;
- and
- (d) 0.05 parts per 1 part of polymer of an organic radical initiator selected from the group consisting of azobisalkylnitrile, azobiscyclohexylcarbonitrile, azobisester, phenylazotriphenylmethane, phenylazothiophenylether, phenylazophenylamine, azobisbenzoyl, tetraalkylterazane, 4,4'-azobis-4-cyano valeric acid, dibenzothiazoledisulfide, metal compound of 2-mercapto benzothiazole, N-cyclohexyl-2-benzothiazolysulphenamide, tetraalkylthiuramdisulfide, and metal derivatives of dialkyldithiocarbamic acid, and
- (2) blending the composition prepared according to step (1) at elevated temperatures until the temperature of the blend is raised to about 40.degree.-60.degree. C.
Dependencies are inferred from the claim text.