Abstract: A photopolymerizable composition comprising a vinylic compound, a sulfur-containing compound and an .alpha.-diketone is disclosed. The sulfur-containing compound may be a mercaptobenzoic acid or a polysulfide.

Abstract: Disclosed is a photopolymerizable dental composition consisting essentially of (A) a composite filler obtained by non-catalytically polymerizing a carboxylic acid monomer with a vinyl monomer in a polymerization system having an inorganic compound dispersed therein; (B) a monomer mixture composed of 2,2-bis[4-(methacryloxyethoxy)phenyl]propane, at least one hexafunctional urethane methacrylate having an isocyanuric acid skeleton, and an ethylenic vinyl monomer diluent; and (C) a photopolymerization initiator. The composite resin obtained by curing this dental composition has high mechanical strength and good water resistance.

Abstract: A composition for artificial marble which comprises a polymer composition in which an inorganic substance and an organic polymer are firmly bound in one body and a vinyl compound, said polymer composition being obtained by polymerizing a polymerizable vinyl monomer, in the presence of at least one monomer selected from the group consisting of carboxylic acid monomer, sulfonic acid monomer, and sulfonate monomer, in an aqueous polymerization system containing an inorganic substance dispersed therein; and a processs for producing artificial marble from said composition by cast polymerization with the addition of a polymerization initiator.

Abstract: A polymer composition wherein an inorganic substance and an organic polymer are firmly consolidated, which is characterized by being produced by polymerizing a vinyl monomer susceptible to radical polymerization in a polymerization system containing a dispersed inorganic substance in the presence of at least one monomer selected from sulfonic acid monomers, sulfonate monomers, or carboxylic acid monomers represented by the general formula [I] ##STR1## wherein R.sub.1 is a hydrogen atom, alkyl group having 1 to 20 carbon atoms, phenyl group, derivative of phenyl group, or halogen atom, X is CONH, ##STR2## COO(CH.sub.2).sub.m or (CH.sub.2).sub.n (wherein R.sub.2 and R.sub.3 are each a hydrogen atom or alkyl group having 1 to 15 carbon atoms, R.sub.4 is an alkylene group having 1 to 15 carbon atoms, m is an integer of 1 to 20, and n is an integer of 0 to 20), and Y is a hydrogen atom, ammonium radical, or an alkali metal atom, or by the general formula [II] ##STR3## wherein R.sub.

Abstract: A polymer composition in which an organic polymer and carbon fiber are strongly combined and a process for producing the polymer composition by the electrolytic polymerization of a reactive monomer using the carbon fiber as an electrode, which process is characterized in that the polymerization is carried out by adding an aliphatic epoxy compound, alicyclic epoxy compound, organic titanate compound, or vinylsilane compound, as part or all of the reactive monomer.

Abstract: A polymer composition wherein an inorganic substance and an organic polymer are firmly consolidated, which is characterized by being produced by polymerizing a vinyl monomer susceptible to radical polymerization in a polymerization system containing a dispersed inorganic substance in the presence of at least one monomer selected from sulfonic acid monomers, sulfonate monomers, or carboxylic acid monomers represented by the general formula [I] ##STR1## wherein R.sub.1 is a hydrogen atom, alkyl group having 1 to 20 carbon atoms, phenyl group, derivative of phenyl group, or halogen atom, X is CONH, ##STR2## COO(CH.sub.2).sub.m or (CH.sub.2).sub.n (wherein R.sub.2 and R.sub.3 are each a hydrogen atom or alkyl group having 1 to 15 carbon atoms, R.sub.4 is an alkylene group having 1 to 15 carbon atoms, m is an integer of 1 to 20, and n is an integer of 0 to 20), and Y is a hydrogen atom, ammonium radical, or an alkali metal atom, or by the general formula [II] ##STR3## wherein R.sub.