Abstract: The present invention has its object to provide a photoradical- and photocation-curable composition improved in curability. The present invention relates to a photoradical- and photocation-curable composition which comprises: (A) a vinyl polymer having, per molecule, two or more groups represented by the general formula (1): —OC(O)C(Ra)?CH2??(1) wherein Ra represents a hydrogen atom or an organic group containing 1 to 20 carbon atoms, at least one of which groups occurs at a molecular terminus, and (B) an epoxy compound and/or oxetane compound and that the N atom-containing compound concentration in the component (A) is not higher than 1,000 ppm and the N atom-containing compound concentration relative to the component (B) is not higher than 2,300 ppm.

Abstract: A liquid sealing agent used for automobile parts, electric parts, various kinds of machine parts and the like exhibits good oil resistance, heat resistance, adhesiveness and flexibility. A vinyl polymer has at least one crosslinkable silyl group and can yield a cured product exhibiting an oil resistance superior to that of a cured product from a reference polymer obtained by replacing the repeating unit thereof with butyl acrylate alone, in any one item of the immersion test according to JIS K 6258 for the land use 3-5 lubricating oil specified in JIS K 2215.

Abstract: The present invention has its object to provide an acrylic curable composition which is improved in tackiness, retention and other adhesive properties without reducing the thermal stability and weather resistance. The above-mentioned object can be solved by a curable composition which comprises, as an essential component, polymer (I), which is a (meth)acrylic acid ester copolymer having, in each molecule, at least one group represented by the general formula 1: —OC(O)C(Ra)?CH2??(1) ?(wherein Ra represents a hydrogen atom or a hydrocarbon group containing 1 to 20 carbon atoms) at a terminus of the molecular chain and is obtained by (co)polymerizing an (meth)acrylic acid alkyl ester the alkyl moiety of which contains 7 to 20 carbon atoms.

Abstract: A sealing material, which comprises a curing product of a composition comprising (A) an acrylic polymer having at least one alkenyl group capable of undergoing hydrosilylation reaction, (B) a hydrosilyl group-containing compound and (C) a hydrosilylation catalyst as essential components, is suitable for use as cam cover seals and oil pan seals for automobile engines, fuel cell cooling medium seals, automobile wire harnesses seals, HDD cover gasket or vibration-insulating HDD cover gasket seals, etc.

Abstract: It is an object of the present invention to provide a curable which has good storage stability and can give cured products retaining the high elongation characteristic originating from the polyether polymer and showing a high gel fraction and good weatherability. Thus, the present invention provides a durable composition which comprises the following two components: a polyether polymer having at least one crosslinkable functional group and a vinyl polymer which is compatible with said polyether polymer having at least one crosslinkable functional group at a polymer terminus. Further, the present invention provides a curable composition which comprises the following three components: a polyether polymer having at least one crosslinkable functional group, a vinyl polymer incompatible with said polyether polymer and having at least one crosslinkable function group, and a compatibilizing agent capable of compatibilizing said polyether polymer and said vinyl polymer with each other when added to a mixture thereof.

Abstract: A method for producing a (meth)acrylic polymer having crosslinkable silyl groups at the termini, comprising a step of adding a hydrosilane compound having a crosslinkable silyl group to an alkenyl-terminated (meth)acrylic polymer (A), which is prepared by atom transfer radical polymerization, in the presence of a platinum hydrosilylation catalyst. The amount of the platinum hydrosilylation catalyst is 0.1 to 10 mg on a platinum metal basis per kilogram of the alkenyl-terminated (meth)acrylic polymer (A). An object of the invention is to provide a method for producing a (meth)acrylic polymer having terminal crosslinkable silyl.

Abstract: The present invention provides a composition for on-site forming gaskets, which has excellent heat resistance, weather resistance, oil resistance, curability, compression set, and the like, a gasket, and (meth)acrylic acid and a curable composition thereof. Specifically, the present invention provides a composition for on-site forming gaskets containing a vinyl polymer with a (meth)acryloyl group at a molecular end as an essential component, and a gasket, a cured product of the composition exhibiting predetermined compression set. Also, the present invention provides a (meth)acrylic polymer having a (meth)acryloyl group at a molecular end and a curable composition thereof, a cured product exhibiting high oil resistance.

Abstract: The present invention has its object to provide a curable composition which comprises a vinyl polymer capable of providing cured products generally showing good mechanical characteristics, oil resistance and thermal stability, among others and can be cured by the hydrosilylation reaction and, further, showing excellent curing characteristics so far unattainable with the prior art compositions.

Abstract: The present invention has for its object to provide a curable composition which, despite its low viscosity, gives a cured product with a high gel fraction, low residual tack, low modulus, high elongation, and good flexibility. The present invention relates to a curable composition comprising the following two components: (A) a vinyl polymer having at least one crosslinking silyl group on the average per molecule: and (B) a photocurable substance, (C) an air oxidation-curable substance, (D) a high molecular plasticizer, (E) a reactive plasticizer or (F) a compound having one silanol group in its molecule and/or a compound capable of reacting with moisture to give a compound having one silanol group in the molecule.

Abstract: The present invention provides: a process for preparing a vinyl polymer containing a halogen in an amount of 1,000 mg or less per kilogram, in which a vinyl polymer containing the halogen produced by atom transfer radical polymerization of a vinyl monomer is heated at a temperature in the range of 140 to 250° C. to dehalogenate the vinyl polymer; a vinyl polymer obtained by the process; and a hydrosilylation-reactive curable composition containing the vinyl polymer.

Abstract: The present invention has for its object to provide a curable composition which, despite its low viscosity, gives a cured product with a high gel fraction, low residual tack, low modulus, high elongation, and good flexibility. The present invention relates to a curable composition comprising the following two components: (A) a vinyl polymer having at least one crosslinking silyl group on the average per molecule: and (B) a photocurable substance, (C) an air oxidation-curable substance, (D) a high molecular plasticizer, (E) a reactive plasticizer or (F) a compound having one silanol group in its molecule and/or a compound capable of reacting with moisture to give a compound having one silanol group in the molecule.

Abstract: The present invention is concerned with a vinyl polymer having at least one group of the general formula (1) per molecule at the molecular chain terminus. -Z-R—CR1?CR2R3??(1) wherein Z represents an oxygen atom, a sulfur atom, a group of the formula NR?, R? represents a univalent hydrocarbon group containing 1 to 20 carbon atoms, or a bivalent organic group containing 1 to 20 carbon atoms, and R represents a carbonyl group, a direct bond or a bivalent organic group containing 1 to 20 carbon atoms; R1 and R2 are the same or different and each represents a hydrogen atom or a univalent organic group group containing 1 to 20 carbon atoms, and R3 represents an organic group containg 1 to 20 carbon atoms. The present invention is further concerned with a curable composition comprising the above vinyl polymer.

Abstract: The present invention relates to a method for producing a vinyl polymer retaining the ability for atom transfer radical polymerization, a method for reliably producing a vinyl polymer having terminal functional groups, a vinyl polymer having functional groups prepared by these methods, and a curable composition comprising the polymer. A vinyl polymer having terminal functional groups can be reliably produced through the steps of preparing a vinyl polymer by atom transfer radical polymerization of a vinyl monomer in a polymerization solvent in the presence of a polymerization initiator and a transition metal complex functioning as a polymerization catalyst, removing the polymerization solvent and the vinyl monomer while the ability for atom transfer radical polymerization is maintained, and supplying a functional-group-introducing agent having a low polymerizability to introduce a functional group to a polymer terminus.

Abstract: It is a subject to improve wet performances and noise performances while restricting degradations in dry performances, and for solving this subject, the pneumatic tire is comprised of a tread grounding surface that is partitioned into four to five regions by three to four main grooves that extend successively in the tire circumferential direction. The main grooves are comprised of one large width main groove which groove width comprises 4 to 20% of a tread grounding width and which is apart from the tire equator by a distance corresponding to 5 to 30% of the tread grounding width further to one grounding end side, and small width main grooves that are disposed between the large width main groove and the other grounding end and which groove width is larger than 2.0 mm but smaller than that of the large width main groove. Both groove side edges of the large width main groove extends in a successive and linear manner in the tire circumferential direction without being interrupted.

Abstract: The present invention is concerned with a vinyl polymer having at least one group of the general formula (1) permolecule at the molecular chain terminus. —Z—R—CR1?CR2R3??(1) wherein Z represents an oxygen atom, a sulfur atom, a group of the formula NR?, R? represents a univalent hydrocarbon group containing 1 to 20 carbon atoms, or a bivalent organic group containing 1 to 20 carbon atoms, and R represents a carbonyl group, a direct bond or a bivalent organic group containing 1 to 20 carbon atoms; R1 and R2 are the same or different and each represents a hydrogen atom or a univalent organic group containing 1 to 20 carbon atoms, and R3 represents an organic group containing 1 to 20 carbon atoms. The present invention is further concerned with a curable composition comprising the above vinyl polymer.

Abstract: The invention has its object to provide a curable composition having improved compatibility of a high-molecular-weight polyether polymer and a vinyl polymer and excellent in mechanical properties. The invention uses a curable composition which comprises a polyether polymer (I) having at least one crosslinkable functional group and a number average molecular weight of 10,000 or higher, and a vinyl polymer (II) having at least one crosslinkable functional group at a polymer terminus and compatible with the polyether polymer (I). As the vinyl polymer (II), a poly(n-butyl acrylate/ethyl acrylate/octadecyl acrylate) copolymer may be mentioned, for example.

Abstract: The present invention provides: a process for preparing a vinyl polymer containing a halogen in an amount of 1,000 mg or less per kilogram, in which a vinyl polymer containing the halogen produced by atom transfer radical polymerization of a vinyl monomer is heated at a temperature in the range of 140 to 250° C. to dehalogenate the vinyl polymer; a vinyl polymer obtained by the process; and a hydrosilylation-reactive curable composition containing the vinyl polymer.

Abstract: A pneumatic tire comprises: a carcass ply turned up around a bead core in each bead portion from the inside to the outside of the tire so as to form a pair of turnup portions and a main portion therebetween; a bead apex disposed between the carcass ply turnup portion and main portion; and a reinforcing rubber layer disposed axially outside the carcass ply, wherein the bead apex extends radially outwardly from the bead core up to a position at a radial height in a range of from 10 to 25 mm from the radially outer end of the bead core; the reinforcing rubber layer extends radially outwardly beyond the maximum tire section width point, and radially inwardly beyond the radially outer edge of the turnup portion; and the bead apex and reinforcing rubber layer are each made of a hard rubber, and the difference in hardness therebetween is not more than 15 degrees.

Abstract: The present invention relates to a vinyl polymer terminated in a silanol group, a hydrolyzable silyl group or an acrylic functional group, to a method of producing a vinyl polymer having a hydrolyzable silyl group at one or more termini thereof which comprises reacting a vinyl polymer having a silanol group at one or more termini thereof with a silicon compound having two or more silicon atom-bound hydrolyzable groups, and a method of producing a vinyl polymer having an acrylic functional group at one or more termini thereof which comprises reacting a vinyl polymer having a silanol group at one or more termini thereof with a silicon compound represented by the general formula (3): XSiR2-G-O—C(O)C(L)=CH2??(3) wherein X is a hydrolyzable group.

Abstract: This invention provides a production method of a vinyl polymer having a functional group at a molecular chain terminus which comprises adding a compound (I) having a functional group and an internal alkenyl group or conjugated polyene compound (II) in the living radical polymerization of a radical-polymerizable vinyl monomer. The present invention relates to a vinyl polymer having a functional group at a molecular terminus, a production method of the same and a curable composition containing said polymer.