Provided is a curable resin composition for a dry-etching resist, the curable resin composition containing a polymer (A) having, in a side chain, a particular structure including an aromatic group having a vinyl group. The polymer (A) includes 80 to 100 wt % of the particular structure. In addition, provided are a dry-etching resist mask obtained by curing the curable composition for a dry-etching resist, and the dry-etching resist mask having a pattern formed by a nanoimprint method.

What is provided is a method for producing a composite-particle composition including a first step of obtaining a dispersion liquid of fine fibers; a second step of coating a surface of liquid droplets of a polymerizable monomer or a polymer with the fine fibers in the dispersion liquid to stabilize the liquid droplets as an emulsion; a third step of polymerizing the liquid droplets of the polymerizable monomer or the polymer to obtain composite particles including the polymer coated with the fine fibers; and a fourth step of adsorbing a compound that forms an ionic bond in a pair with an ionic functional group of the fine fibers onto the fine fibers in the surface of the composite particles.

What is provided is a method for producing a composite-particle composition including a first step of obtaining a dispersion liquid of fine fibers; a second step of coating a surface of liquid droplets of a polymerizable monomer or a polymer with the fine fibers in the dispersion liquid to stabilize the liquid droplets as an emulsion; a third step of polymerizing the liquid droplets of the polymerizable monomer or the polymer to obtain composite particles including the polymer coated with the fine fibers; and a fourth step of adsorbing a compound that forms an ionic bond in a pair with an ionic functional group of the fine fibers onto the fine fibers in the surface of the composite particles.

Provided are hollow particles which are more excellent in heat resistance and dispersibility than ever before and which are lightweight. The hollow particles containing hollow resin particles having a surface covered with inorganic fine particles, wherein a volume average particle diameter of the hollow particles is from 0.1 μm to 9.0 μm, and a void ratio thereof is from 55% to 95%; wherein a repeating unit constituting the resin of the hollow resin particles contains a crosslinkable monomer unit, and a content of the crosslinkable monomer unit is from 25 to 100 parts by mass, with respect to 100 parts by mass of the resin; wherein a primary particle diameter of the inorganic fine particles is from 10 nm to 120 nm; and wherein the inorganic fine particles are contained at from 5 to 180 parts by mass, with respect to 100 parts by mass of the hollow resin particles.

Provided are hollow particles which are more excellent in heat resistance and dispersibility than ever before and which are lightweight. The hollow particles containing hollow resin particles having a surface covered with inorganic fine particles, wherein a volume average particle diameter of the hollow particles is from 0.1 μm to 9.0 μm, and a void ratio thereof is from 55% to 95%; wherein a repeating unit constituting the resin of the hollow resin particles contains a crosslinkable monomer unit, and a content of the crosslinkable monomer unit is from 25 to 100 parts by mass, with respect to 100 parts by mass of the resin; wherein a primary particle diameter of the inorganic fine particles is from 10 nm to 120 nm; and wherein the inorganic fine particles are contained at from 5 to 180 parts by mass, with respect to 100 parts by mass of the hollow resin particles.

Responsive or degradable branched polymers may be prepared by the free radical polymerisation of a multivinyl monomer in the presence of a chain transfer agent, using a source of radicals, wherein the extent of propagation is controlled relative to the extent of chain transfer to prevent gelation of the polymer. The multivinyl monomer may comprise a cleavable group, for example an ester, or a multiplicity of such groups, between two vinyl groups. Said monomer may be a macromonomer containing multiple cleavage sites.

Responsive or degradable branched polymers may be prepared by the free radical polymerisation of a multivinyl monomer in the presence of a chain transfer agent, using a source of radicals, wherein the extent of propagation is controlled relative to the extent of chain transfer to prevent gelation of the polymer. The multivinyl monomer may comprise a cleavable group, for example an ester, or a multiplicity of such groups, between two vinyl groups. Said monomer may be a macromonomer containing multiple cleavage sites.

A hydrocarbon resin polymer is provided. The hydrocarbon resin polymer includes: 0.15-15 mol % of repeating units (A), which are derived from bridged ring monomer compounds; 15-90 mol % of repeating units (B), which are derived from monovinyl aromatic compounds; and 8-80 mol % of repeating units (C), which are derived from divinyl aromatic compounds.

A hydrocarbon resin polymer is provided. The hydrocarbon resin polymer includes: 0.15-15 mol % of repeating units (A), which are derived from bridged ring monomer compounds; 15-90 mol % of repeating units (B), which are derived from monovinyl aromatic compounds; and 8-80 mol % of repeating units (C), which are derived from divinyl aromatic compounds.

A method for producing hollow particles which have a void ratio of 50% or more, the method comprising: preparing a mixture liquid containing a polymerizable monomer, a hydrophobic solvent, an aqueous medium, etc., suspending the mixture liquid to prepare a suspension in which droplets of a monomer composition containing the polymerizable monomer, the hydrophobic solvent, etc., are dispersed in the aqueous medium, and subjecting the suspension to a polymerization reaction to prepare a precursor composition containing precursor particles having a hollow portion surrounded by a shell and filled with the hydrophobic solvent, wherein the polymerizable monomer a hydrocarbon monomer, and in 100% by mass of the polymerizable monomer, a content of a crosslinkable monomer containing two or more ethylenically unsaturated double bonds is 70% by mass or more, and wherein the hydrophobic solvent is a hydrocarbon solvent containing 5 to 8 carbon atoms.