Abstract: The silicone rubber composition of the invention comprises, as the peroxide curing agent, a neopentane diol derivative represented by the general formulaR.sup.1 --O--O--CO--O--CH.sub.2 --C(CH.sub.3).sub.2 --CH.sub.2 --O--CO--O--O--R.sup.2,in which R.sup.1 and R.sup.2 are each, independently from the other, a monovalent hydrocarbon group having 3 to 10 carbon atoms or a silyl group of the general formula --SiR.sup.3.sub.3, R.sup.3 being a methyl, ethyl or phenyl group, such as trimethyl silyl, in admixture with a diorganopolysiloxane and a reinforcing silica filler. By virtue of this unique formulation, the silicone rubber composition is suitable for hot-air vulcanization without compression as in the vulcanization process by extrusion molding followed by heating in a hot-air oven.

Abstract: The invention provides a silicone-coated release paper having a coating surface film of an organopolysiloxane composition curable by irradiation with ultraviolet light or electron beams to give a fully cured film resistant to migration of the organopolysiloxane constituents therefrom on to other surfaces in contact therewith. The composition comprises (a) a diorganopolysiloxane terminatd at both molecular chain ends each with a divinylmethylsilyl group or trivinylsilyl group, (b) an organohydrogenpolysiloxane having at least 2 hydrogen atoms directly bonded to the silicon atoms in a molecule, (c) a catalytic amount of a platinum or rhodium catalyst and, optionally, (d) a compound of a rare earth element such as ceric oxide.

Abstract: A rubber composition capable of giving a highly oil-resistant vulcanizate with an organic peroxide as the vulcanizing agent is proposed. The composition is a blend of an EPM or EPDM rubber and an acrylic rubber loaded with a reinforcing filler, of which the latter rubber is a copolymer having at least two vinylsilyl groups in a molecule as the pendant groups introduced by the copolymerization of one or more acrylic monomers with a vinylsilyl-containing organosilicon compound having an aliphatically unsaturated group copolymerizable with the acrylic monomers in a molecule, such as CH.sub.2 .dbd.CH--CO--O--CH.sub.2 CH.sub.2 CH.sub.2 --Si-- and CH.sub.2 .dbd.CH--C.sub.6 H.sub.4 --Si--. The covulcanizate has the high mechanical strengths of the EPM or EPDM rubber and the high oil resistance of the acrylic rubber in combination.

Abstract: A silicone rubber composition suitable for hot-air vulcanization under normal pressure without the disadvantages of surface tackiness and internal voids in the cured rubber products and also free from the problems of corrosiveness to metals and toxicity to workers, which comprises, as the curing agent for the organopolysiloxane, a peroxide derivative of dibenzoyl peroxide which is substituted on each of the benzene nuclei with substituted silyl, e.g. trimethyl silyl, group or a silyl-substituted methyl, e.g. trimethylsilyl methyl, group.

Abstract: A BTRS (buried Twin-Ridge Substrate) structure laser, wherein an oblong protrusion (10) is provided on a substrate (1) of a first conductivity type and two ridges (9, 9) divided by a groove (31) therebetween are provided on a second layer (2) of a second conductivity type, and thereon plural layers (3, 4, 5, 6) including an active layer (4) are provided is improved to have longer service life such that: the protrusion (10) is shortened so as to have its both ends apart inside cavity facet of the substrate (1), or further by width of each ridge (9, 9) is narrowed at both ends thereof thereby forming narrowed end parts (9', 9'), so that excessive current injection to the active layer near the cavity facet is eliminated.

Abstract: The silicone rubber composition comprises, in addition to the conventional ingredients of a high-polymeric diorganopolysiloxane and a reinforcing silica filler, a specific phosphorus-containing organic compound, such as phosphinates, phosphonates and phosphates, in a limited amount. By virtue of this unique ingredient, the composition can give a cured silicone rubber product having greatly improved resistance against dynamic fatigue.

Abstract: A crosslinkable copolymer is prepared by the copolymerization of a first ethylenically unsaturated monomer and a second monomer substituted by a vinyl-containing cyclic organosilicon group such as ##STR1## in which Vi and Me denote vinyl and methyl groups, respectively. When such a copolymer is admixed with a crosslinking agent such as an organic peroxide and shaped with heating, the crosslinkable copolymer is crosslinked so that the shaped article is imparted with greatly improved properties.

Abstract: Vulcanizates of so-called EPM and EPDM rubber compositions can be imparted with greatly improved flame retardancy and emit a greatly decreased volume of smoke in burning when the rubber composition is compounded with a conventional flame retardant agent of aluminum or magnesium hydroxide together with a polymer of an acrylic acid ester and an organopolysiloxane in combination or a copolymer composed of the moieties of these two kinds of monomeric units in a limited weight proportion.

Abstract: In a TRS (twin ridge substrate) type semiconductor laser, reflectivity at both facets of the resonator at the oscillation wavelength is selected to be higher than the reflectivity of the semiconductor crystal of the laser device, but smaller than 1, thereby stabilizing the light oscillation with a low S/N ratio.

Abstract: A photoresist processing solution includes a 2-hydroxyethyl-(mono-or polyoxyethyl) trialkyl ammonium hydroxide and is used in a process for development of photoresists having a solubility in aqueous alkaline solution which is a function of exposure to light.

Abstract: The inventive copolymer composition is satisfactorily curable or vulcanizable into, for example, a rubbery elastomer even by an organic peroxide contained therein as a crosslinking agent. The crosslinkable copolymer comprised therein is a polymer having, in a molecule, at least two monomeric units each having a vinyl-containing organosilicon pendant group represented by the general formula (Vi.sub.m R.sup.1.sub.n SiO).sub.a Vi.sub.b R.sup.2.sub.c Si--, in which Vi is a vinyl group, R.sup.1 is a hydrogen atom or a group selected from the class consisting of monovalent hydrocarbon groups free from aliphatic unsaturation, hydroxy group and hydrolyzable groups excepting halogen atoms, R.sup.2 is a hydrogen atom or a monovalent hydrocarbon group, m is 1, 2 or 3, n is zero, 1 or 2, a is 1, 2 or 3, b is zero, 1 or 2 and c is zero, 1 or 2 with the proviso that a+b=1, 2 or 3 and a+b+c=3.

Abstract: A semiconductor substrate having a groove with a dove-tail-shaped cross section is used as a substrate and thereon, several epitaxial layers including an active layer are formed and a current injection region is formed immediately above the groove; the semiconductor laser attains a high power lasing with the fundamental transverse mode.

Abstract: The rubber composition is formulated with (A) a combination of an ethylene-propylene copolymeric rubber and an organopolysiloxane having at least two alkenyl groups per molecule as the polymeric base, (B) a reinforcing silica filler, (C) an alkoxysilane compound and (D) a thiocarbamyl-containing organosilane compound. The rubber composition can be vulcanized with an organic sulfur compound or organic peroxide as the vulcanizing agent to give a vulcanizate having quite satisfactory mechanical properties including, in particular, greatly improved heat resistance and greatly decreased permanent compression set even without using carbon black as the reinforcing filler. The omission of carbon black in the formulation gives an advantage that the rubber may be colored in any light color.

Abstract: The radiation-curable organopolysiloxane composition of the invention is quite free from the problem of the migration of silicone toward the surface of a body in contact with the surface of the cured film of the composition even by curing with an extremely small dose of radiation, e.g. ultraviolet light and electron beams, for curing. The mechanism for curing is in principle the radiation-induced addition reaction between the aliphatically unsaturated bonds in a first organopolysiloxane and the mercapto groups in a second organopolysiloxane but the aliphatically unsaturated bond in the first organopolysiloxane is bonded preferably remotely from the silicon atom with an electron-attractive atom or group intervening therebetween such as the divalent groups of the formula --O--CH.sub.2).sub.2 S-- and --CH.sub.2 --O--CH.sub.2 --S--.

Abstract: An epoxy resin-based composition suitable for encapsulation of semiconductor devices is proposed. The resin composition is capable of giving a cured resin encapsulation highly resistant against crack formation by virtue of the unique ingredient therein, in addition to the thermally curable epoxy resin and an inorganic filler, which is a combination of an organopolysiloxane having a hydrocarbon group substituted by certain functional groups, e.g. glycidyl, amino, mercapto and the like, and a block copolymer composed of the segments of a polymeric aromatic moiety and segments of an organopolysiloxane moiety.

Abstract: A flame-retardant silicone rubber composition is prepared by admixing a base compound of a dimethylpolysiloxane gum and a siliceous filler with a combination of a platinum compound and an organosilicon compound having at least one nitrogen-containing organic group and at least one aliphatically unsaturated group in a molecule in such a proportion that the molar ratio of nitrogen to platinum is within a specified range. The effect of flame retardancy exhibited by the composition is so reliable and constant that the effect can be obtained regardless of the type of the peroxide curing agent and the curing behavior of the composition is never affected by the formulation of the flame retardant agent.

Abstract: The inventive method for forming a cured film on a substrate surface comprises coating the surface with a room temperature curable organosiloxazane polymer comprising, in a molecule, (a) at least one organosiloxane unit represented by the unit formula (a) at least one organosiloxane unit represented by the unit formulaR.sup.1.sub.a SiO.sub.(4-a)/2,and (b) at least one organosilazane unit represented by the unit formulaR.sup.2.sub.b Si(NR.sup.3).sub.(4-b)/2,in which R.sup.1, R.sup.2 and R.sup.3 are each a hydrogen atom or a substituted or unsubstituted monovalent hydrocarbon group, not all of them being simultaneously hydrogen atoms, and the subscripts a and b are each a positive integer of 1, 2 or 3 with the proviso that a and b cannot be simultaneously equal to 3, in a molecule and subjecting the coating film to exposure to a moisture-containing atmosphere. The method is useful for forming a surface-protecting film or for imparting surface releasability.

Abstract: The invention provides a chemical etching method for a semiconductor device, which comprises a step of forming a first layer of Ga.sub.1-x Al.sub.x As (0.ltoreq.x<1) having a surface (100), a step of forming on the first layer a second layer of Ga.sub.1-y Al.sub.y As (0.ltoreq.y<1) having a surface (100), and a step of chemically etching the layers from a level above the second layer and along the direction of <011>. The slope angle of etch face of the second layer depends on the mol fraction y of the second layer, and the slope angle of etch face of the first layer depends on the mol fraction y of the second layer and the mol fraction x of the first layer. These facts are best utilized in the invention so that the etch profile of the first layer may have a desired slope angle.

Abstract: In a laser of such type that the distribution of the effective refractive index varies in a direction which is along the face of its active layer and perpendicular to the direction of the laser light transmission, thereby defining the active region to be between a pair of refractive index changing zones, the refractive indexes of a pair of end surfaces of a laser resonator (i.e. the active region) is made smaller than the intrinsic refractive indexes of the cleavage face of the active layer.

Abstract: The invention provides a novel method for surface priming when adhesive bonding is desired between a rubber, e.g. silicone rubber, and a substrate of a material such as a metal or plastic resin. The inventive method is performed by use of a primer composition of which the principal ingredient is an organosilicon polymer hitherto not used for such a purpose. The organosilicon polymer is represented by the average unit formula R.sub.a Six.sub.4-a, in which R is a monovalent hydrocarbon group, X is a divalent atom or group selected from the class consisting of an oxygen atom, an imino group, alkylene groups and a phenylene group and a is a positive number of 0.2 to 1.8, at least one of the hydrocarbon groups denoted by R in a molecule being aliphatically unsaturated and at least 10% by moles of the groups denoted by X in a molecule being the imino groups.