Disclosed is a rubber composition which suppresses poor mixing or poor dispersion from occurring between an organic polymer material derived from natural rubber and an inorganic material such as silica and exhibits excellent viscoelastic properties, and a silane coupling agent composition used in the same. Also disclosed is a silane coupling agent composition comprising a protein modifying agent and a silane compound represented by Formula (1):

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wherein each of the variables is as defined herein.

An acrylic rubber includes 20 to 35% by weight of ethyl methacrylate units (a), 0 to 20% by weight of ethyl acrylate units (b), 50 to 75% by weight of n-butyl acrylate units (c), and 0.5 to 4% by weight of carboxyl group-containing monomer units (d).

An acrylic rubber includes 20 to 35% by weight of ethyl methacrylate units (a), 0 to 20% by weight of ethyl acrylate units (b), 50 to 75% by weight of n-butyl acrylate units (c), and 0.5 to 4% by weight of carboxyl group-containing monomer units (d).

An acrylic rubber includes 20 to 35% by weight of ethyl methacrylate units (a), 0 to 20% by weight of ethyl acrylate units (b), 50 to 75% by weight of n-butyl acrylate units (c), and 0.5 to 4% by weight of carboxyl group-containing monomer units (d).

A polymer composition includes at least one poly(aryl ether ketone) (PAEK) component and at least one low molecular weight aromatic compound. A polymer metal junction including the polymer composition and a method of making a polymer metal junction are also described.

A polymer composition includes at least one poly(aryl ether ketone) (PAEK) component and at least one low molecular weight aromatic compound. A polymer metal junction including the polymer composition and a method of making a polymer metal junction are also described.

A prepreg having excellent tackiness as well as excellent resin strength after curing and strength in the non-fiber direction is described; and a fiber-reinforced composite material using the prepreg, where the prepreg is composed of reinforcing fibers and a resin composition which includes [A] an epoxy resin, [B] a dicyanamide and [C] a compound having a melting point of 130° C. or lower and a solubility parameter whose difference from the solubility parameter of [B] is 8 or less.

A prepreg having excellent tackiness as well as excellent resin strength after curing and strength in the non-fiber direction is described; and a fiber-reinforced composite material using the prepreg, where the prepreg is composed of reinforcing fibers and a resin composition which includes [A] an epoxy resin, [B] a dicyanamide and [C] a compound having a melting point of 130° C. or lower and a solubility parameter whose difference from the solubility parameter of [B] is 8 or less.

A polymer composition includes a conductive polymer and at least one stretchability and electrical conductivity (STEC) enhancer, wherein a content of the STEC enhancer in the composition is at least about 1 wt. % of the composition.

A polymer composition includes a conductive polymer and at least one stretchability and electrical conductivity (STEC) enhancer, wherein a content of the STEC enhancer in the composition is at least about 1 wt. % of the composition.