Provided are a polyphenyl ether resin composition and a prepreg and a laminated board containing same. The polyphenyl ether resin composition comprises the following components: (1) a tetrafunctional or higher multifunctional acrylate-modified thermosetting polyphenyl ether resin; and (2) a vinyl resin cross-linking agent, the weight of the vinyl resin cross-linking agent being 40-100 parts by weight based on 100 parts by weight of the tetrafunctional or higher multifunctional acrylate-modified thermosetting polyphenyl ether resin. The modified thermosetting polyphenyl ether resin, due to containing a tetrafunctional or higher multifunctional acrylate active group, can cross-link more vinyl resin cross-linking agents. Not only the prepared high-speed electronic circuit substrate has low dielectric constant and dielectric loss, but also double bonds in side chains of the vinyl resin cross-linking agent are reacted completely in a resin curing system, so that the high-speed electronic circuit substrate has a better thermo-oxidative aging resistance.

Blends of elastomer composites with unfilled or less highly filled elastomer reduces hysteresis without compromising reinforcement. Hysteresis may also be reduced by adjusting the compounding method.

Disclosed are fluorinated vinyl polymer resin compositions, and prepregs and laminate materials containing the same. The fluorinated vinyl polymer resin composition includes a fluorine-substituted vinyl polymer resin and a functional polymer, where the fluorine-substituted vinyl polymer resin has the chemical structure: ##STR00001## where the maximum particle size is less than about 100 microns, at least one of the substituents R.sub.1, R.sub.2, R.sub.3, and R.sub.4 includes a fluorine atom, and where n is greater than about 100. The fluorinated vinyl polymer resin composition can be incorporated in prepreg and laminate materials.

A preparation method of a rubber composition for a tire assures that good processability can be obtained even if a silane coupling agent having a mercapto group is blended. The preparation method of a rubber composition for a tire is characterized by initiating kneading of a rubber component and a compound represented by the following formula (1) before kneading the rubber component and a silane coupling agent having a mercapto group. ##STR00001##
(Wherein each of R.sup.1 to R.sup.4 independently represents a straight-chain or branched chain alkyl group having 1 to 18 carbon atoms or a cycloalkyl group having 5 to 12 carbon atoms.)

Thermosetting epoxy resin compositions on the one hand at room temperature in the incompletely cured state exhibit extremely slight alteration in shape and on the other hand develop a high surface tack, and, moreover, in the fully cured state are of high impact strength and at the same time exhibits high adhesion, particularly to metallic substrates. These compositions are ideally suited to the production of self-adhesive reinforcing elements.

The present disclosure provides an all-steel tire with 100% definite elongations of an upper tread and a lower tread being interrelated to each other. The all-steel tire of the present disclosure includes a lower tread rubber layer B and an upper tread rubber layer A. Through repeated multiple experiments of the applicant, when a ratio of stresses at 100% definite elongation of the upper tread rubber layer A to the lower tread rubber layer B is (0.7-0.8):1, and the 100% stress at definite elongation of the lower tread rubber layer B is 3.2-5.5 Mpa, it can be ensured that after any tread of the tire is subjected to performance adjustment, the performance balance of the whole tire crown is continuously maintained, so that no new problem is generated after the tread performance of the all-steel radial tire is improved.

Disclosed herein are rubber compositions comprising: (a) natural rubber, polyisoprene, or a combination thereof; (b) at least one conjugated diene monomer containing polymer or polymer; (c) a first silica filler having a BET surface area of at least 220 m.sup.2/g; (d) a second silica filler having a BET surface area lower than that of the first silica filler and greater than 135 m.sup.2/g; and (e) optionally carbon black filler.

A flame-retardant sealing material comprising a polyurethane foam formed from a polyurethane raw material containing a polyol component, an isocyanate, a water repellent, a flame retardant and the like, wherein the polyol component contains a hydroxyl-terminated prepolymer obtained by the reaction of a polyether polyol and an isocyanate, the water repellent is a polybutadiene polyol or the like, the flame retardant is (1) a non-halogen non-condensed phosphate ester or (2) a halogen-containing non-condensed phosphate ester, which are liquid at ordinary temperature, and the isocyanate index is 100 to 150.

According to a production method of a rubber composition for tire of the present invention comprising a rubber component (A) comprising at least one selected from the group consisting of a natural rubber and a synthetic diene rubber, a filler, a coupling agent (D) of (C.sub.pH.sub.2p+1O).sub.3Si(CH.sub.2).sub.qSCOC.sub.kH.sub.2k+1, and a vulcanizing agent (E) comprising a vulcanizer and a vulcanization accelerator, the method comprising: a step X1 of kneading all amount of A, a part of the filler and a part of D, a step X2 of kneading the kneaded product of step X1, the remaining amount of the filler and D, and a step F of kneading the kneaded product of step X2 and E, it is possible to produce a rubber composition for tire in which fuel efficiency and abrasion resistance are improved in a good balance.

A rubber composition is provided. The rubber roller including a roller body formed of a porous body formed by foaming and crosslinking the rubber composition and an image forming device including the rubber roller are also provided. In the rubber composition, fine porous particles of at least one type selected from a group consisting of zeolite, activated carbon, and diatomite along with a crosslinking component and a foaming component are mixed into a rubber that contains at least one type selected from a group consisting of diene-based rubbers and ethylene propylene-based rubbers and an ion-conductive rubber. A rubber roller includes a roller body that is formed by cylindrically extrusion-molding and crosslinking the rubber composition. An image forming device has the rubber roller 1 assembled thereinto.