Provided is a tire that prevents a polyurethane foam layer from discoloring to brown. A tire comprises: a polyurethane foam layer laminated on an outer layer of the tire with a barrier layer therebetween, wherein the polyurethane foam layer contains a polyurethane foam, and the barrier layer is formed from a rubber composition containing butyl rubber as a rubber component.

A coating agent for a rubber-coated cylinder head gasket contains a lubricant and a urethane resin. The lubricant is unsintered polytetrafluoroethylene resin particles having an average primary particle size of 1 μm or less. The amount of the unsintered polytetrafluoroethylene resin particles in a solid content is 30 to 80% by volume. The present invention provides a coating agent for a rubber-coated cylinder head gasket that can form a coat that is highly wear-resistant under high contact pressure and high temperature conditions and with which a rubber layer is less likely to stick to the seal face of the cylinder block or the cylinder head after the use under high contact pressure and high temperature conditions, and a cylinder head gasket obtained using the coating agent.

A coating agent for a rubber-coated cylinder head gasket contains a lubricant and a urethane resin. The lubricant is unsintered polytetrafluoroethylene resin particles having an average primary particle size of 1 μm or less. The amount of the unsintered polytetrafluoroethylene resin particles in a solid content is 30 to 80% by volume. The present invention provides a coating agent for a rubber-coated cylinder head gasket that can form a coat that is highly wear-resistant under high contact pressure and high temperature conditions and with which a rubber layer is less likely to stick to the seal face of the cylinder block or the cylinder head after the use under high contact pressure and high temperature conditions, and a cylinder head gasket obtained using the coating agent.

[Object] To provide the underlayer composition for the disc brake pad, which may be applicable to the manufacturing process of softening the rubber by heating even if the uncrosslinked fluororubber in the underlayer composition and the disc brake pad with an excellent brake noise suppression effect.

[Means to Resolve] To use the underlayer composition containing 5-15 weight % of the uncrosslinked fluororubber relative to the entire amount of the underlayer composition, 4-8 weight % of the phenol-based resin as the binder relative to the entire amount of the underlayer composition, and 0.3-2 weight % of the hexamethylenetetramine as the curing agent for the phenol-based resin relative to the entire amount of the underlayer composition.

[Object] To provide the underlayer composition for the disc brake pad, which may be applicable to the manufacturing process of softening the rubber by heating even if the uncrosslinked fluororubber in the underlayer composition and the disc brake pad with an excellent brake noise suppression effect.

[Means to Resolve] To use the underlayer composition containing 5-15 weight % of the uncrosslinked fluororubber relative to the entire amount of the underlayer composition, 4-8 weight % of the phenol-based resin as the binder relative to the entire amount of the underlayer composition, and 0.3-2 weight % of the hexamethylenetetramine as the curing agent for the phenol-based resin relative to the entire amount of the underlayer composition.

A sulfur-modified chloroprene polymer latex includes an emulsifier and a sulfur-modified chloroprene polymer obtained by modifying a chloroprene polymer (A) with sulfur (B), wherein the sulfur amount Y in the sulfur-modified chloroprene polymer and the z-average particle size X of the sulfur-modified chloroprene polymer satisfy formulae (1) to (3) (formula (1): 0.10<Y<0.60; formula (2): 120<X<320; and formula (3): Y<0.0025X−0.20), the total amount of a chloroprene monomer (A-1) and a monomer (A-2) copolymerizable with the chloroprene monomer which constitute the chloroprene polymer is 100 parts by mass, the amount of sulfur (B) contained in the sulfur-modified chloroprene polymer is Y parts by mass, and the z-average particle size of the sulfur-modified chloroprene polymer is X nm. The sulfur-modified chloroprene polymer latex composition can also include a metal oxide (C), a cross-linking accelerator (D), and an antioxidant (E).

A sulfur-modified chloroprene polymer latex includes an emulsifier and a sulfur-modified chloroprene polymer obtained by modifying a chloroprene polymer (A) with sulfur (B), wherein the sulfur amount Y in the sulfur-modified chloroprene polymer and the z-average particle size X of the sulfur-modified chloroprene polymer satisfy formulae (1) to (3) (formula (1): 0.10<Y<0.60; formula (2): 120<X<320; and formula (3): Y<0.0025X−0.20), the total amount of a chloroprene monomer (A-1) and a monomer (A-2) copolymerizable with the chloroprene monomer which constitute the chloroprene polymer is 100 parts by mass, the amount of sulfur (B) contained in the sulfur-modified chloroprene polymer is Y parts by mass, and the z-average particle size of the sulfur-modified chloroprene polymer is X nm. The sulfur-modified chloroprene polymer latex composition can also include a metal oxide (C), a cross-linking accelerator (D), and an antioxidant (E).

A sulfur-modified chloroprene polymer latex includes an emulsifier and a sulfur-modified chloroprene polymer obtained by modifying a chloroprene polymer (A) with sulfur (B), wherein the sulfur amount Y in the sulfur-modified chloroprene polymer and the z-average particle size X of the sulfur-modified chloroprene polymer satisfy formulae (1) to (3) (formula (1): 0.10<Y<0.60; formula (2): 120<X<320; and formula (3): Y<0.0025X−0.20), the total amount of a chloroprene monomer (A-1) and a monomer (A-2) copolymerizable with the chloroprene monomer which constitute the chloroprene polymer is 100 parts by mass, the amount of sulfur (B) contained in the sulfur-modified chloroprene polymer is Y parts by mass, and the z-average particle size of the sulfur-modified chloroprene polymer is X nm. The sulfur-modified chloroprene polymer latex composition can also include a metal oxide (C), a cross-linking accelerator (D), and an antioxidant (E).

A conjugated diene-based polymer of the present invention has an absolute molecular weight measured by viscosity detector-equipped GPC-light scattering measurement, of 40×10.sup.4 or more and 5000×10.sup.4 or less, has a branching number (Bn) measured by the viscosity detector-equipped GPC-light scattering measurement, of 8 or more, and has a modification ratio of 60% by mass or more.

A conjugated diene-based polymer of the present invention has an absolute molecular weight measured by viscosity detector-equipped GPC-light scattering measurement, of 40×10.sup.4 or more and 5000×10.sup.4 or less, has a branching number (Bn) measured by the viscosity detector-equipped GPC-light scattering measurement, of 8 or more, and has a modification ratio of 60% by mass or more.