A high-recoverability resin particles having a mean particle size of 1 to 100 μm containing a crossdinked (meth)acrylic acid ester-based resin, wherein the high-recoverability resin particles have a recovery rate of 22% or greater, and a 30% compression strength of 1.5 to 5.0 kgf/mm.sup.2.

The present invention relates to a cross-linkable rubber composition, a cross-linked rubber composition obtained by cross-linking such a rubber composition, a method of preparing a tyre and a tyre. In a cross-linkable rubber composition the cross-linkable rubber composition comprises, per hundred parts by weight of rubber (phr): ≥1 phr to ≤99 phr of a rubber component selected from the group of styrene-butadiene rubber (SBR), polybutadiene rubber (BR), natural rubber (NR) or a mixture thereof; and ≥1 phr to ≤120 phr of an aliphatic resin component. The composition further comprises ≥1 phr to ≤50 phr of a polyisoprene rubber (IR) having ≥mol-%, as determined by NMR spectroscopy, of 3,4-linked units derived from isoprene. It has surprisingly been found that such a polyisoprene rubber having 3,4-linked units derived from isoprene in combination with aliphatic resin worked very well in broadening the tan delta curve of the compound, indicating the compound can perform well in wide range of conditions when cured and used as a rubber for a tyre tread.

The present invention relates to a cross-linkable rubber composition, a cross-linked rubber composition obtained by cross-linking such a rubber composition, a method of preparing a tyre and a tyre. In a cross-linkable rubber composition the cross-linkable rubber composition comprises, per hundred parts by weight of rubber (phr): ≥1 phr to ≤99 phr of a rubber component selected from the group of styrene-butadiene rubber (SBR), polybutadiene rubber (BR), natural rubber (NR) or a mixture thereof; and ≥1 phr to ≤120 phr of an aliphatic resin component. The composition further comprises ≥1 phr to ≤50 phr of a polyisoprene rubber (IR) having ≥mol-%, as determined by NMR spectroscopy, of 3,4-linked units derived from isoprene. It has surprisingly been found that such a polyisoprene rubber having 3,4-linked units derived from isoprene in combination with aliphatic resin worked very well in broadening the tan delta curve of the compound, indicating the compound can perform well in wide range of conditions when cured and used as a rubber for a tyre tread.

A method for method for preparing a functionalized polymer, the method comprising the steps of preparing an active polymerization mixture including a reactive polymer by polymerizing conjugated diene monomer with a lanthanide-based catalyst; introducing a heterocyclic nitrile compound with the reactive polymer to form a functionalized polymer within the polymerization mixture; introducing a quenching agent to the polymerization mixture including the functionalized polymer, where the ratio of water or protic hydrogen atoms in the quenching agent to the lanthanide atoms in the lanthanide-based catalyst is less than 1500 to 1.

A method for method for preparing a functionalized polymer, the method comprising the steps of preparing an active polymerization mixture including a reactive polymer by polymerizing conjugated diene monomer with a lanthanide-based catalyst; introducing a heterocyclic nitrile compound with the reactive polymer to form a functionalized polymer within the polymerization mixture; introducing a quenching agent to the polymerization mixture including the functionalized polymer, where the ratio of water or protic hydrogen atoms in the quenching agent to the lanthanide atoms in the lanthanide-based catalyst is less than 1500 to 1.

The present invention aims to provide a viscosity-index improving agent having an excellent friction reduction effect to reduce friction of a lubricating oil composition when the viscosity-index improving agent is added thereto. The present also aims to provide a lubricating oil composition containing the viscosity-index improving agent. The present invention relates to, for example, a viscosity-index improving agent containing: (co)polymer (A) containing, as an essential constituent monomer, a polyolefin-based monomer (a) represented by the following formula (1); an ester oil (B1) having a kinematic viscosity at 100° C. of 1.00 to 2.50 mm.sup.2/s; and an ester oil (B2) having a kinematic viscosity at 100° C. of 2.51 to 5.00 mm.sup.2/s:

##STR00001##

wherein R.sup.1 is a hydrogen atom or a methyl group; —X.sup.1— is a group represented by —O—, —O(AO).sub.m-, or —NH—, A is a C2-C4 alkylene group, m is an integer of 1 to 10, and each A may be the same or different when m is 2 or more; R.sup.2 is a residue after removal of one hydrogen atom from a hydrocarbon polymer containing a 1,2-butylene group as a structural unit; and p represents a number of 0 or 1.

Provided is a thermosetting resin composition capable of forming a resin layer having sufficiently low relative dielectric constant and dissipation factor, and high flexibility and toughness in a relatively short period of time, a cured material thereof, a prepreg, a laminate, a metal clad laminate, and a printed circuit board. This is accomplished by a thermosetting resin composition including a (A) polymerizable polyphenylene ether compound of General Formula (1), an (B) elastomer, and a (C) tetrafluoroethylene-based polymer particle, wherein a content of (C) is from 1 parts by mass to 30 parts by mass, with respect to 100 parts by mass of the composition.

The present invention aims to provide a viscosity-index improving agent capable of providing a lubricating oil composition having an appropriate gelation index, an excellent HTHS viscosity at 100° C., and an excellent kinematic viscosity at 40° C. when the viscosity-index improving agent is added thereto. The present also aims to provide a lubricating oil composition containing the viscosity-index improving agent. The present invention relates to, for example, a viscosity-index improving agent containing a copolymer (A) and an ester oil (Z), the copolymer A containing, as constituent monomers, a polyolefin-based monomer (a) represented by the following formula (1), a monomer (b) represented by the following formula (2) in which R.sup.4 is a C4 alkyl group, and at least one of a monomer (c) represented by the following formula (3) and a monomer (d) represented by the following formula (2) in which R.sup.4 is a C2-C3 alkyl group:

##STR00001##

wherein R.sup.1 is a hydrogen atom or a methyl group; —X.sup.1— is a group represented by —O—, —O(AO).sub.m—, or —NH—, A is a C2-C4 alkylene group, m is an integer of 1 to 10, and each A may be the same or different when m is 2 or more; R.sup.2 is a residue after removal of one hydrogen atom from a hydrocarbon polymer containing a 1,2-butylene group as a structural unit; and p represents a number of 0 or 1;

##STR00002##

wherein R.sup.3 is a hydrogen atom or a methyl group; —X.sup.2— is a group represented by —O— or —NH—; and R.sup.4 is a C2-C4 alkyl group;

##STR00003##

wherein R.sup.5 is a hydrogen atom or a methyl group; —X.sup.3— is a group represented by —O— or —NH—; R.sup.6 is a C2-C4 alkylene group; R.sup.7 is a C1-C8 alkyl group; and r is an integer of 1 to 20, and each R.sup.6 may be the same or different when r is 2 or more.

An objective of the present invention is to provide a resin composition capable of improving at least either one of heat resistance and visible light transmission. A resin composition according to an aspect of the present invention contains a coloring agent and a resin, and the coloring agent contains a compound represented by a formula (I), a formula (II), a formula (III) or a formula (IV).

##STR00001##

An objective of the present invention is to provide a resin composition capable of improving at least either one of heat resistance and visible light transmission. A resin composition according to an aspect of the present invention contains a coloring agent and a resin, and the coloring agent contains a compound represented by a formula (I), a formula (II), a formula (III) or a formula (IV).

##STR00001##