A golf ball according to the present invention comprises: a core having a diameter of 37-39 mm and a first density; a mantle which surrounds the core, includes amorphous alloy powder, and has a thickness of 0.8-1.2 mm and a second density; and a cover which surrounds the mantle and has a thickness of 1-1.4 mm and a third density.

A resin-rubber composite in which a polyamide-based resin-molded product or a polyphenylene sulfide-based resin-molded product is directly vulcanization-bonded to a peroxide-crosslinkable nonpolar rubber composition, which forms a rubber layer, without interposing an adhesive, wherein both resin-molded products have a polymerized film with a radical, which is formed by activating the surface of the product, in the case of polyamide-based resin-molded products, by low-pressure plasma treatment by a microwave method using inert gas, or by activating the surface of the product, in the case of polyphenylene sulfide-based resin-molded products, by low-pressure plasma treatment by a microwave method using active gas, and then performing low-pressure plasma treatment by a microwave method using a hydrocarbon-based monomer in both cases. The resin-rubber composite can be effectively used for drum seals, automobile parts such as side cover seals for transmissions, anti-vibration rubber, resin rubber laminate hoses, and the like.

Provided is a method for producing a polyisoprenoid, which can increase natural rubber production by enhancing the rubber synthesis activity of rubber particles. The present invention provides methods for producing a polyisoprenoid using a gene coding for a cis-prenyltransferase (CPT) family protein, a gene coding for a Nogo-B receptor (NgBR) family protein and a gene coding for a rubber elongation factor (REF) family protein, specifically a method for producing a polyisoprenoid in vitro using rubber particles bound to proteins coded for by these genes, and a method for producing a polyisoprenoid in vivo using a recombinant organism (plant) having these genes introduced therein.

A method of manufacturing a marine hose that at least a base hose, a sponge layer, a foam rubber layer, and a cover rubber layer. The method comprises the steps of: wrapping a sponge layer around the outside of the base hose; wrapping a foam rubber layer around the outside of the sponge layer, the foam rubber layer containing an unvulcanized foam rubber composition; wrapping a cover rubber layer around the outside of the foam rubber layer; and vulcanizing the wrapped assembly; wherein the foam rubber composition includes a rubber component containing as a main component at least one selected from the group consisting of natural rubber, styrene butadiene rubber, chloroprene rubber, ethylene propylene rubber, ethylene propylene diene rubber, and reclaimed rubber.

Multi-stage composite materials, their preparation, and their uses are described. A composite includes a first layer of a first material contributing to mechanical strength of the composite having a first length, and a second layer of a second material contributing to the mechanical strength of the composite having a second length, wherein the second length is greater than the first length, wherein the second length of the second layer is affixed to the first length of the first layer at both ends of the first and second lengths so that the second layer is spaced apart from the first layer.

Presented are fiber-reinforced polymer (FRP) composite components with integrated polymer parts, methods for making/using such FRP composite components, and vehicles equipped with battery packs sealed inside FRP battery enclosures by integrated elastomeric seals. An FRP composite component, such as a rigid battery tray basin, includes a component body that is formed with a polymer matrix material, such as a fast-curing epoxy resin. A fiber preform, such as a multiaxial-fiber fabric sheet, is encapsulated within the component body and formed with a cluster of fibers bound together in a predefined formation. A polymer seal, such as an elastomeric bulb seal, includes a seal head and a mounting base. The seal's mounting base is stitched to the fiber preform and at least partially encapsulated within the component body. The seal head protrudes from the fiber preform and extends through an aperture in the component body.