Abstract: The present invention provides rubber compositions having an excellent transparency and rubber properties comprising a rubbery polymer and an inorganic filler, and relates to specific methods of producing said rubber. Thus, they are rubber compositions comprising 100 parts by weight of at least one rubbery polymer and 5–150 parts by weight of an inorganic filler per 100 parts by weight of said rubbery polymer, wherein the haze is 50% or less, and the inorganic bulking agents are dispersed so that the number of circular regions with a diameter of 0.5 ?m or greater having no inorganic fillers is one or less and the number of circular regions with a diameter of 0.3 ?m or greater having no inorganic fillers is three or less in an image of a 5 ?m square of said rubber composition determined by a scanning probe microscope (SPM) and wherein the haze of said rubber composition having a thickness of 5 mm is 50% or less, and specific methods of producing them.

Abstract: The invention relates to: a modified rubber having a specific structure modified with a compound having two or more epoxy groups in the molecule; and a process for producing a modified rubber which includes copolymerizing a vinylaromatic hydrocarbon and a conjugated diene by the solution polymerization method using an organolithium as an initiator and modifying the resultant copolymer with a compound having two or more epoxy groups in the molecule. The invention further relates to a modified-rubber composition obtained by compounding a raw rubber containing the modified rubber with silica, and to rubber vibration isolators and a footwear article each obtained from the modified-rubber composition.

Abstract: The present invention provides rubber compositions having an excellent transparency and rubber properties comprising a rubbery polymer and an inorganic filler, and relates to specific methods of producing said rubber. Thus, they are rubber compositions comprising 100 parts by weight of at least one rubbery polymer and 5-150 parts by weight of an inorganic filler per 100 parts by weight of said rubbery polymer, wherein the haze is 50% or less, and the inorganic bulking agents are dispersed so that the number of circular regions with a diameter of 0.5 ?m or greater having no inorganic fillers is one or less and the number of circular regions with a diameter of 0.3 ?m or greater having no inorganic fillers is three or less in an image of a 5 ?m square of said rubber composition determined by a scanning probe microscope (SPM) and wherein the haze of said rubber composition having a thickness of 5 mm is 50% or less, and specific methods of producing them.

Abstract: The invention relates to: a modified rubber having a specific structure modified with a compound having two or more epoxy groups in the molecule; and a process for producing a modified rubber which includes copolymerizing a vinylaromatic hydrocarbon and a conjugated diene by the solution polymerization method using an organolithium as an initiator and modifying the resultant copolymer with a compound having two or more epoxy groups in the molecule. The invention further relates to a modified-rubber composition obtained by compounding a raw rubber containing the modified rubber with silica, and to rubber vibration isolators and a footwear article each obtained from the modified-rubber composition.