Abstract:
A flame-retardant composition includes: a powdery acid-modified hydrogenated block copolymer (a) having a bulk density of 0.1 to 0.4 g/ml and which is a hydrogenated block copolymer modified by addition of an unsaturated carboxylic acid or a derivative thereof, the hydrogenated block copolymer comprises a polymer block A composed mainly of a vinyl aromatic compound unit and a polymer block B composed mainly of a conjugated diene unit, and has a weight average molecular weight of 50,000 to 500,000; a polyolefin resin (b); a non-aromatic rubber softener (c); and a metal hydrate (d). The flame-retardant composition contains the components (a), (b), (c) and (d) in proportions that satisfy the following relationships (1) to (3): 0.1≦Wa/(Wa+Wb)≦0.9 (1) 0.05≦Wc/(Wa+Wb+Wc)≦0.5 (2) 0.4≦Wd/(Wa+Wb+Wc+Wd)≦0.75 (3) wherein Wa, Wb, Wc and Wd represent masses of the acid-modified hydrogenated block copolymer (a), the polyolefin resin (b), the non-aromatic rubber softener (c) and the metal hydrate (d), respectively.
Abstract:
A flame-retardant composition includes: a powdery acid-modified hydrogenated block copolymer (a) having a bulk density of 0.1 to 0.4 g/ml and which is a hydrogenated block copolymer modified by addition of an unsaturated carboxylic acid or a derivative thereof, the hydrogenated block copolymer comprises a polymer block A composed mainly of a vinyl aromatic compound unit and a polymer block B composed mainly of a conjugated diene unit, and has a weight average molecular weight of 50,000 to 500,000; a polyolefin resin (b); a non-aromatic rubber softener (c); and a metal hydrate (d). The flame-retardant composition contains the components (a), (b), (c) and (d) in proportions that satisfy the following relationships (1) to (3): 0.1≦Wa/(Wa+Wb)≦0.9 (1) 0.05≦Wc/(Wa+Wb+Wc)≦0.5 (2) 0.4≦Wd/(Wa+Wb+Wc+Wd)≦0.75 (3) wherein Wa, Wb, Wc and Wd represent masses of the acid-modified hydrogenated block copolymer (a), the polyolefin resin (b), the non-aromatic rubber softener (c) and the metal hydrate (d), respectively.
Abstract:
An expansion molding apparatus for forming molded articles having consistently or partially thin-walls by expanding expandable thermoplastic resin beads in a cavity formed between molds with the application of heat. The apparatus has a moving device, for example, a cylinder which moles the molds in one orthogonal direction relative to a closing direction of the molds when filling the cavity with the expandable thermoplastic resin beads. After filling the resin beads in the cavity by moving at least one of the molds in at least one direction orthogonal to the closing direction so that a distance in a circumference section of the cavity becomes greater, the mold is moved back to the original position and the application of heat is performed to obtain molded articles.
Abstract:
A pressure sensitive adhesive composition is provided which comprises a tri-block copolymer (a) consisting of aromatic vinyl block-conjugated diene block-aromatic vinyl block in which the conjugated diene moiety is hydrogenated and a block copolymer (b) consisting of an aromatic vinyl block and a conjugated diene block in which the conjugated diene moiety is hydrogenated. The adhesive composition is significantly improved in low temperatures characteristics, adhesion and processability with good adhesion.
Abstract:
Modified cis-1,4-polyisoprene rubber obtained by incorporating into cis-1,4-polyisoprene rubber a side chain formed by succinimide residue containing in the N position a hydrocarbon residue having at least one tertiary nitrogen atom. This rubber is excellent in green strength at ordinary room temperature, and flowability at an elevated temperature. Its vulcanizate is comparable to, or better than natural rubber in breaking strength and hardness.
Abstract:
An adhesive composition suitable for a hot melt adhesive or hot melt pressure-sensitive adhesive, which comprises a block copolymer (a) and a tackifier (b), wherein said block copolymer (a) has at least one polymer block A being a hydrogenated butadiene polymer block having a 1,2-bond content of 20 mol % or less and at least one polymer block B substantially having an olefin polymer structure different from the polymer block A and having a glass transition temperature of -20.degree. C. or less and a heat of crystalline fusion of 8 cal/g or lower, and containing the polymer block A before hydrogenation in an amount of 3 to 80 wt. %.
Abstract:
There is provided a curable sealing composition comprising a low molecular weight rubber, a curing agent and other additives as required and being characterized in that a block copolymer of isoprene and butadiene with a viscosity average molecular weight of 7,000-150,000 is used as the low molecular weight rubber. The composition has a good workability, and when cured, produces seals having excellent thermal stability, elasticity and sealing effect.
Abstract:
A rubber composition with improved processability and capable of affording a vulcanizate with improved properties including improved adhesion to a metal surface is disclosed. The composition comprises a modified liquid polyisoprene rubber and a natural rubber. The modified liquid polyisoprene rubber is an adduct of maleic anhydride or a derivative thereof with a liquid polyisoprene rubber with a cis-1,4 content of not less than 70% and a molecular weight of 8,000 to 100,000, the amount of said maleic anhydride or said derivative being 0.1 to 15 mol % per isoprene unit in said liquid polyisoprene rubber.
Abstract:
A rubber composition having excellent processability and improved dispersion state of carbon black containing:a functional group-containing polymer having a number average molecular weight of 1,000 to 100,000 and comprising 0 to 60 mole % of a structural unit represented by the formula (1) and 100 to 40 mole % of a structural unit represented by formula (2) plus a structural unit represented by formula (3), the polymer having on one end of its molecule an average at least 0.6 group per molecule of a group represented by formula (4), a hydroxyl group or an amino group; ##STR1## wherein R.sup.1 represents a hydrogen atom or a methyl group, ##STR2## wherein R.sup.2 represents a hydrogen atom or a methyl group, ##STR3## wherein R.sup.3 represents a vinyl group or an isopropenyl group;--COOR.sup.4 (4) wherein R.sup.4 represents a hydrogen atom or an alkali metal;a solid rubber andcarbon black.
Abstract:
A method of forming molded articles having consistently or partially thin-walls by expanding expandable thermoplastic resin beads in a cavity formed between molds with the application of heat. The introduction of the resin beads is carried out after causing the width of a circumference section of the cavity to be greater than the diameter of the beads by moving one of or both of the molds in at least one direction orthogonal to a direction of closing the molds, the molds are then moved back to the normal positions, and the introduced resin beads are heated to form the molded article. Also, an expansion molding apparatus having a moving device such as a cylinder which moves the molds in at least one direction orthogonal to the closing direction during the introduction of the expandable thermoplastic resin beads, whereby consistently or partially thin-walled molded articles are manufactured.