Abstract: A tapered hollow shaft made of a fiber reinforced composite material, which comprises: (a) at least one angle layer consisting essentially of polyacrylonitrile-based carbon fibers having a tensile modulus ranging from 200 to 500 GPa and a tensile strength ranging from 4000 to 5600 MPa; (b) at least one straight layer consisting essentially of polyacrylonitrile-based carbon fibers having a tensile modulus ranging from 200 to 460 GPa and a tensile strength ranging from 3500 to 5600 MPa; (c) at least one reinforcing layer consisting essentially of pitch-based carbon fibers or polyacrylonitrile-based carbon fibers each having a compressive breaking strain of 1.7 to 5.0%, a tensile modulus ranging from 5 to 160 GPa, a tensile strength ranging from 500 to 3000 MPa and a density ranging from 1.5 to 1.

Abstract: This invention relates to an aromatic ester (meth)acrylate dendrimer composed of the core formed by an aromatic polycarboxylic acid and the branches formed by an aromatic compound containing one hydroxyl group and two carboxyl groups and represented by the following general formula (1) and also to a curable resin composition which contains the dendrimer and a polymerization initiator as essential components, is low in viscosity and highly curable, and forms a coating film with excellent heat and moisture resistance.

Abstract: This invention relates to a process for purifying benzoic acid continuously to a purity of 99.9% or more by introducing crystals of crude benzoic acid with a bulk density of 0.2 g/cm3 or more and an average particle diameter of 0.3 mm or more into a continuous crystallization apparatus equipped with a stirrer and a heating device from the upper portion of the apparatus, effecting counter-current contact of the falling crystals of crude benzoic acid with the melt generated by heating with the heating device, withdrawing the purified benzoic acid as melt from the lower portion of the apparatus, and withdrawing the mother liquor from the upper portion of the apparatus. The process makes it possible to prepare high-purity benzoic acid continuously in a relatively simple apparatus at high efficiency.

Abstract: This invention relates to laminates for use in HDD suspensions which are composed of a stainless steel base material and successive layers formed thereon of polyimides and an electrical conductor and in which the linear expansion coefficient of the polyimide layer is controlled in the range of 1×10−5/° C. to 3×10−5/° C. and the adhesive strength between stainless steel and polyimide and that between polyimide and electrical conductor are controlled at 0.5 kg/cm or more. This invention also relates to a process for preparing laminates for use in HDD suspensions comprising applying a solution of polyimide precursors or polyimides to a stainless steel base material with a thickness of 10 to 70 &mgr;m in one layer or more, drying, performing heat treatment at 250° C. or more to form a layer of polyimides with a thickness of 3 to 20 &mgr;m and a linear expansion coefficient of 1×10−5/° C. to 3×10−5/° C.

Abstract: Provided is a rubber-modified aromatic vinyl resin composition, wherein(a) 4 to 20% by weight of a rubber-like polymer is contained,(b) the rubber-like polymer is dispersed in the aromatic vinyl polymer in the form of grains, and the dispersed grains have a weight-average grain diameter falling in a range of 0.4 to 0.8 .mu.m,(c) the dispersed grains have 1.0 .mu.m or less of a 5% value and 0.2 .mu.m or more of a 95% value in a cumulative grain diameter distribution on a weight basis,(d) a ratio of toluene-insoluble matters to a rubber component each of which is contained in the said composition falls in a range of 1.0 to 2.5, and(e) 0.005 to 0.5% by weight of a silicone oil or the mixed oil of the same amount of silicone oil and a fluorine compound oil of 0.0002 to 0.03% by weight is contained in the said composition. The rubber-modified aromatic vinyl resin composition described above is excellent in a balance between an impact resistance and a rigidity, and has an excellent gloss.

Abstract: Rubber-modified styrenic resin compositions of this invention comprise 90 to 30% by weight of rubber-modified styrenic resins (A) containing rubbery polymers dispersed with an average particle diameter of 0.3 to 2.0 .mu.m in the phase of styrenic polymers (C) and 10 to 70% by weight of styrene-(meth)acrylate ester copolymer resins (B) and, in said compositions, the content of (meth)acrylate ester units is 5 to 50% by weight and the toluene-insolubles (% by weight: X) and the rubber component (% by weight: Y) are present at a ratio (X/Y) in the range from 1.2 to 3.5. The compositions excel in appearance, scratch resistance, impact resistance and rigidity and are easy to fabricate.

Abstract: A printing web transporting roller is disclosed which is characterized by using as the roller basis thereof a roller basis made of a fiber-reinforced plastics and provided on the peripheral surface thereof with a plurality of portions of a surface of large curvature and a plurality of portions of a surface of small curvature alternately arranged in a mutually adjoining state and having a composite coating film superposed on the roller basis and composed of a porous ceramic layer formed by thermal spraying and a resin layer formed on the surface of the ceramic layer and inside the pores in the ceramic layer.

Abstract: This invention relates to a process for preparing indan derivatives and comprises a process for preparing cis-1-amino-2-indanol by treating (.+-.)indan-1,2-diol and/or its 2-formate derivative with specific microbes to give optically active 2-hydroxy-1-indanone, converting the optically active 2-hydroxy-1-indanone to its oxime, and treating the oxime with hydrogen or a hydrogen donor in the presence of a heterogeneous hydrogenation catalyst, a process for preparing optically active 2-hydroxy-1-indanone and/or optically active indan-1,2-diol by treating (.+-.)indan-1,2-diol and/or its 2-formate derivative with specific microbes, and a process for preparing cis-1-amino-2-indanol by treating the oxime of 2-hydroxy-1-indanone with hydrogen or a hydrogen donor in the presence of a heterogeneous hydrogenation catalyst.

Abstract: A rubber-modified styrenic resin composition obtained by graft-polymerizing a styrenic monomer dissolving a rubber-like polymer, wherein(1) the rubber-like polymer is dispersed in a styrenic polymer matrix in the form of particles having a volume average particle diameter falling in the range of 0.5 to 1.6 .mu.m,(2) the dispersed particles of said rubber-like polymer are of a salami structure in which a part of the styrenic polymer having a number average particle diameter falling in the range of 0.13 .mu.m or more and up to 0.20 .mu.m and a particle diameter distribution falling in the range of 1.15 to 1.35 is dispersed and included in the rubber-like polymer particles, and(3) the dispersed particles of said rubber-like polymer have a swelling ratio falling in the range of 7 to 12 in toluene.The rubber-modified styrenic resin composition of the present invention is excellent in mechanical strength, a gloss and a coloring property and has a good balance between them.

Abstract: In a step of spinning a molten mesophase pitch in a process for manufacturing a pitch-type carbon fiber, the pitch is allowed to pass through an orifice and to be contracted once, is then expanded in an introduction port with a diameter greater than that of the orifice, and is then allowed to pass through an outlet pore formed at a collecting portion to spin the pitch. The pitch-type carbon fiber has a high elastic modulus in tension and high compressive strength.

Abstract: This invention relates to resin solution compositions for electronic materials consisting of organic solutions of 100 parts by weight of siloxanepolyimidepolyamic acid copolymers composed of imide segments formed by polycondensation of aromatic tetracarboxylic acid dianhydrides and siloxanediamines and amic acid segments formed by polyaddition of aromatic tetracarboxylic acid dianhydrides and aromatic diamines other than siloxanediamines and represented by the following general formula (1) (in which X is the residue of an aromatic tetracarboxylic acid dianhydride, Y is the residue of a siloxanediamine, Z is the residue of an aromatic diamine, l and m are integers independent of each other, and n is an integer of 1 or more) and 1 to 50 parts by weight of epoxy resins. The compositions are storage-stable and curable at relatively low temperature and yield cured products with an excellent balance of heat resistance, high-frequency characteristics, chemical resistance and stress relaxation characteristics.

Abstract: The present invention provides a needle coke for graphite electrodes, wherein a needle coke, used as a raw material coke, comprises a coke of 100 parts by weight, to which adheres a substance of 0.03 to 16 parts by weight having a softening point, or a melting point, or a temperature at which it thermally decomposes without leaving a residue (after subjecting it to a heat treatment at 200.degree. C. or higher), which does not exceed 1800.degree. C., which substance comprises preferably 0.05 to 5 parts by weight of at least one boron, phosphorus or silicon compound, or pyrex glass. Also provided is a process for producing the needle coke. The use of the above needle coke in producing graphite electrodes can effectively inhibit puffing in a graphitizing step and improve the yield of the electrodes as well as enhancing product characteristics.

Abstract: Compounds of the following general formula (I) and pharmaceutically acceptable salts thereof.

Abstract: An epoxy resin composition of this invention is obtained by solidifying epoxy resins represented by the following general formula (1) (wherein G is glycidyl group and R.sup.1 to R.sup.8 are hydrogen atoms, halogen atoms or hydrocarbon groups with 1 to 6 carbon atoms, and n is an integer of 0 to 10) by crystallization and adding epoxy resin curing agents to the resulting solid. It shows good flow and low moisture absorption, cures with excellent heat resistance at soldering temperature and is useful for a variety of applications, in particular, for encapsulating semiconductor devices.

Abstract: A sound absorbing material which comprises a base layer 1 having a porosity of 5 to 50% by volume and a decorative layer 3 having a porosity of 5 to 50% by volume integrally, and which is obtained by sprinkling inorganic particles 4 containing colored particles in an amount of at least 1% by volume which are coated with a weather-resistant transparent resin so as to form a first particle layer which is to form the decorative layer 3 in the sound absorbing material, sprinkling uncolored inorganic lightweight particles 2 which are coated with a thermosetting resin on the first particle layer so as to form a second particle layer which is to form the base layer 1 in the sound absorbing material, and carrying out thermal compression integral molding of the first particle layer and the second particle layer simultaneously, is lightweight and inexpensive, and is provided with an attractive external stone-grain-like appearance, without impairing the sound absorbing ability of the material.

Abstract: There is provided a multi-layer blow-molded article wherein in a multi-layer marginal-wall region formed of a plurality of layers, a convexly crooked portion projecting generally convexly from inside to outside is so formed that the molding shrinkage factor of a resin for use in a more outer layer is larger than that of a resin for use in a more inner layer, and a concavely crooked portion denting generally concavely from outside to inside is so formed that the molding shrinkage factor of a resin for use in a more outer layer is smaller than that of a resin for use in a more inner layer; and all the layers of the molded article are fittingly secured to each other by means of a clamping force resulting from the difference in molding shrinkage factors of the resins constituting the layers and/or portions defined in a circumferential direction in the multi-layer marginal-wall region.

Abstract: A fiber-reinforced plastic bar comprises a core and a surface member, the core comprises a high strength continuous fiber and a matrix resin, and the surface member comprises a polypropylene fiber. This fiber-reinforced plastic bar does not undergo degradation even when mortar, concrete, etc, are cured in an autoclave.

Abstract: An object of the present invention is to provide a process for producing rubber-modified styrene resins in which a distribution of the diameters of the rubber particles is narrow and the impact resistance is well balanced with the elastic modulus. The constitution thereof is characterized in that an aromatic monovinyl series monomer, a rubbery polymer and a styrene polymer are mixed and dissolved, and the mixed solution is adjusted so that the relation of the content R (wt. %) of the rubbery polymer contained in said mixed solution with the content Ps (wt. %) of the styrene polymer satisfies 0.2<Ps/R<3; the solution is further subjected to pre-heating treatment to maintain the conditions before rubber phase inversion, and then rubber phase inversion is carried out in a plug flow type reactor followed by polymerizing to enhance the polymerization conversion rate in the following plug flow type reactor.

Abstract: The present invention provides a novel silicate group-containing polyimide which is excellent in mechanical properties, heat resistance and electrical properties and has an excellent film forming ability. Further, the present invention provides a film-formable heat resistant material having an excellent solvent resistance, elasticity and adhesive property. The silicate group-containing polyimide has a repeated unit represented by the following Formula (1): ##STR1## wherein Ar.sub.1 represents a tetravalent organic group; R.sub.1 and R.sub.2 each are a single bond or represent an alkylene group having 1 to 4 carbon atoms or a phenylene group; R.sub.3 to R.sub.7, R.sub.9 and R.sub.10 each represent a hydrocarbon group having 1 to 6 carbon atoms; R.sub.8 represents an ethylene group or an alkylene group having 3 to 6 carbon atoms; m and n represent independently an integer of 1 to 10; and k represents an integer of 0 to 2.

Abstract: This invention relates to alkali-developable photosensitive or thermosetting resin compositions obtained by mixing (A) polymerizable unsaturated compounds having main structural units represented by the following general formulas (1) and (2) ##STR1## ?wherein R.sub.1, and R.sub.2 designate hydrogen, alkyl group with 1 to 5 carbon atoms or halogen, R.sub.3 designates hydrogen or methyl group, X designates --CO--, --SO.sub.2 --, --C(CF.sub.3).sub.2 --, --Si(CH.sub.3).sub.2 --, --CH.sub.2 --, --C(CH.sub.3).sub.2 --, --O--, ##STR2## or direct linkage, Y designate acid anhydride residue, Z designates acid dianhydride residue and the mole ratio of the structural units (m/n) is from 1/99 to 90/10 and showing an inherent viscosity (.eta..sub.inh) of 0.1 dl/g or more as determined on a solution of 0.5 g of said compounds in 100 ml of N-methylpyrrolidone at 30.degree. C.