There is described a low number average molecular weight (M.sub.N<10 kD) and high glass transition temperature (>75 C.) copolymer (optionally a solid grade oligomer (SGO)) that comprises (a) at least 20 wt-% of itaconate functional monomer(s), (b) not more than 40% of a hydrophilic monomer, preferably an acid functional monomer(s) in an amount sufficient to achieve an acid value from 65 to 325 mg KOH per g of solid polymer; (c) optionally not more than 70% of other monomers not being either (a) or (b), having a max content of vinyl aromatic monomer(s) of 40 wt-% and/or max content of methacrylate(s) of 40 wt-%; where the weight percentages of monomers (a), (b) and (c) are calculated as a proportion of the total amount of monomers in the copolymer being 100%.

There is described a low number average molecular weight (M.sub.N<10 kD) and high glass transition temperature (>75 C.) copolymer (optionally a solid grade oligomer (SGO)) that comprises (a) at least 20 wt-% of itaconate functional monomer(s), (b) not more than 40% of a hydrophilic monomer, preferably an acid functional monomer(s) in an amount sufficient to achieve an acid value from 65 to 325 mg KOH per g of solid polymer; (c) optionally not more than 70% of other monomers not being either (a) or (b), having a max content of vinyl aromatic monomer(s) of 40 wt-% and/or max content of methacrylate(s) of 40 wt-%; where the weight percentages of monomers (a), (b) and (c) are calculated as a proportion of the total amount of monomers in the copolymer being 100%.

The present invention provides a novel curable composition in which a reaction is caused to occur between a hydroperoxide and a thiourea compound to initiate polymerization of a radical polymerizable monomer and which has excellent adhesive properties, moderate curability, and excellent long-term storage stability. The present invention relates to a curable composition (A) containing: a radical polymerizable monomer (a1) having no acidic group; a hydroperoxide compound (a2); and at least one cyclic thiourea compound (a3) selected from the group consisting of a substituted ethylenethiourea compound (a3-1), a substituted propylenethiourea compound (a3-2), and a substituted butylenethiourea compound (a3-3) each having a specific structure with a cyclic structure moiety into which a substituent is introduced.

The present invention provides a novel curable composition in which a reaction is caused to occur between a hydroperoxide and a thiourea compound to initiate polymerization of a radical polymerizable monomer and which has excellent adhesive properties, moderate curability, and excellent long-term storage stability. The present invention relates to a curable composition (A) containing: a radical polymerizable monomer (a1) having no acidic group; a hydroperoxide compound (a2); and at least one cyclic thiourea compound (a3) selected from the group consisting of a substituted ethylenethiourea compound (a3-1), a substituted propylenethiourea compound (a3-2), and a substituted butylenethiourea compound (a3-3) each having a specific structure with a cyclic structure moiety into which a substituent is introduced.

Polymer particle embolics and methods of making same are described. The particle embolics can be used as embolization agents.

The present invention provides a composition for a semiconductor device, where the composition is such that the removability of residues is excellent and the dissolution of tungsten is further suppressed. The composition for a semiconductor device contains a resin having a repeating unit A derived from a polymerizable compound containing a nitrogen atom and water, where a ClogP of the polymerizable compound is 0.5 or more and a solubility of the resin in water at 25 C. is 0.01% by mass or more.

The present invention provides a composition for a semiconductor device, where the composition is such that the removability of residues is excellent and the dissolution of tungsten is further suppressed. The composition for a semiconductor device contains a resin having a repeating unit A derived from a polymerizable compound containing a nitrogen atom and water, where a ClogP of the polymerizable compound is 0.5 or more and a solubility of the resin in water at 25 C. is 0.01% by mass or more.

Methods of (co)polymerizing ethylenically-unsaturated materials, including the steps of providing a non-deaerated mixture of free radically (co)polymerizable ethylenically-unsaturated material in a batch reactor, exposing the non-deaerated mixture to a source of ionizing radiation for a time sufficient to initiate (co)polymerization of at least a portion of the free radically (co)polymerizable ethylenically-unsaturated material, and allowing the free radically (co)polymerizable ethylenically-unsaturated material to (co)polymerize under essentially adiabatic conditions while continuing to expose the mixture to the source of ionizing radiation for a time sufficient to yield an at least partially (co)polymerized (co)polymer. The ethylenically-unsaturated materials are selected from vinyl-functional monomers, vinyl-functional oligomers, vinyl-functional macromers, and combinations thereof. The mixture is preferably free of thermally-induced or UV-induced free radical polymerization initiators. The source of ionizing radiation may be a gamma ray source, an x ray source, an electron beam source with an emission energy greater than 300 keV, and combinations thereof.

Methods of (co)polymerizing ethylenically-unsaturated materials, including the steps of providing a non-deaerated mixture of free radically (co)polymerizable ethylenically-unsaturated material in a batch reactor, exposing the non-deaerated mixture to a source of ionizing radiation for a time sufficient to initiate (co)polymerization of at least a portion of the free radically (co)polymerizable ethylenically-unsaturated material, and allowing the free radically (co)polymerizable ethylenically-unsaturated material to (co)polymerize under essentially adiabatic conditions while continuing to expose the mixture to the source of ionizing radiation for a time sufficient to yield an at least partially (co)polymerized (co)polymer. The ethylenically-unsaturated materials are selected from vinyl-functional monomers, vinyl-functional oligomers, vinyl-functional macromers, and combinations thereof. The mixture is preferably free of thermally-induced or UV-induced free radical polymerization initiators. The source of ionizing radiation may be a gamma ray source, an x ray source, an electron beam source with an emission energy greater than 300 keV, and combinations thereof.

The present invention provides a dental adhesive exhibiting excellent initial bond strength and bond durability to both enamel and dentin. The present invention relates to a dental adhesive containing: an asymmetric acrylamide-methacrylic acid ester compound (a); an acid group-containing (meth)acrylic polymerizable monomer (b); and a water-soluble polymerizable monomer (c). The asymmetric acrylamide-methacrylic acid ester compound (a) is represented by the following general formula (1):

##STR00001##

where X is an optionally substituted, linear or branched C.sub.1 to C.sub.6 aliphatic group or an optionally substituted aromatic group, the aliphatic group is optionally interrupted by at least one linking group selected from the group consisting of O, S, CO, COO, OCO, NR.sup.1, CONR.sup.1, NR.sup.1CO, COONR.sup.1, OCONR.sup.1, and NR.sup.1CONR.sup.1, and R.sup.1 is a hydrogen atom or an optionally substituted, linear or branched C.sub.1 to C.sub.6 aliphatic group.