Abstract: A flame-retardant resin composition contains a prepolymer represented by the general formula: ##STR1## wherein R.sub.1 stands for a hydrogen atom or an unreactive saturated group; R.sub.2 stands for a reactive unsaturated group; m and n each stand for a positive number of 1 to 4 and X and Y are each a copolymerization ratio and are in the range of 0.3 to 0.7 with the proviso that the sum total of X and Y is 1,as an essential component.

Abstract: A magnetic recording medium comprising a non-magnetic substrate and a magnetic layer formed thereon, at least the surface portion of said magnetic layer being made from an organic compound having a perfluoro group and a hydrocarbon group is excellent in durability and exhibits good lubricating effect for a long period of time.

Abstract: The present invention provide a thermosetting resin composition comprising(a) a poly-p-hydroxstyrene derivative represented by the general formula ##STR1## wherein A is a halogen group, R.sub.1 is an alkenyl or alkenoyl group of 2 to 4 carbon atoms, m denotes a number of 1 to 4 and from more than denotes a number of 1 to 100,(b) an epoxy-modified polybutadiene, and(c) an aromatic maleimide compound, and a prepreg and a laminated sheet which use said resin composition.

Abstract: A polymer having dihydropyridine rings or dihydrotriazine rings as main constitutional units, an ethynyl- or cyanato-terminated Schiff's compound which is a starting material for producing the polymer, and applications of the polymer.

Abstract: A resin composition comprising an epoxy resin and an isocyanate group-containing fluorine compound is particularly suitable for covering a magnetic recording medium comprising a non-magnetic substrate and formed thereon a thin magnetic film so as to give excellent sliding durability.

Abstract: The present invention provides a thermosetting resin composition comprising(a) a prepolymer of a poly-p-hydroxystyrene derivative represented by the general formula ##STR1## wherein A is a halogen group, R.sub.1 is an alkenyl or alkenoyl group of 2 to 4 carbon atoms, 4 carbon atoms, m denotes a number of 1 to 4 and n denotes a number of 1 to 100,(b) an epoxy-modified polybutadiene, and(c) an aromatic maleimide compound, and a prepreg and a laminated sheet which use said resin composition.

Abstract: A magnetic recording medium comprising a non-magnetic substrate and a magnetic layer formed thereon, at least the surface portion of said magnetic layer being made from an organic compound having a perfluoro group and a hydrocarbon containing group is excellent in durability and exhibits good lubricating effect for a long period of time.

Abstract: A resin composition for printed circuit board and the printed circuit board in which said resin composition is used as substrate, said resin composition comprising one or more cyclic phosphonitrile compounds represented by the general formula [I] and/or [II] and an aromatic maleimide compound and/or an aromatic amine: ##STR1## wherein at least two of R's (R.sub.1 to R.sub.

Abstract: The present invention provide a process for producing printed circuit boards which comprises the steps of(a) roughening a surface of a copper layer formed on an insulating board.(b) coating the roughened surface of copper layer with a photo-resist layer containing a sublimable copper-corrosion inhibitor, exposing the resist layer selectively to actinic rays according to a circuit pattern to form, and developing the resulting resist layer, thereby forming plating-resist coats on circuit-negative pattern portions of the copper layer,(c) heat-treating the plating-resist coats,(d) plating chemically the circuit-corresponding portion with copper,(e) removing the plating-resist coats, and(f) removing the copper layer except the circuit-corresponding portion thereof.

Abstract: A circuit board, which comprises an insulating substrate, a copper wiring having a coarsely roughened surface provided on the insulating substrate, and a copper oxide-reduced layer provided on the coarsely roughened surface of the copper wiring and formed by reduction of copper oxide and electroless plating, the copper oxide-reduced layer having a finely roughed surface and having a deposited layer of at least one of nickel and cobalt, where the copper oxide-reduced layer having a deposited layer of at least one of nickel and cobalt on the surface is roughened in a range of 0.05 to 5 .mu.m in terms of a maximum vertical distance between the top of convex parts and the bottom of concave parts of the copper oxide-reduced layer per .mu.m of the longitudinal distance of the copper oxide-reduced layer, and at least one of nickel and cobalt is deposited in an amount of 5.times.10.sup.-7 to 1.times.10.sup.-4 g/cm.sup.2 on the copper oxide-reduced layer, has a high adhesiveness to an insulating resin.

Abstract: The present invention provides an electrophotographic toner, particularly with a good transferability and a good flowability, which comprises a binder resin and a coloring agent, the binder resin containing a lactone-modified epoxy resin, obtained by subjecting all or a portion of secondary hydroxyl groups of epoxy compounds having hydroxyl groups in the molecules to ring opening polymerization of lactone.The present invention further provides an electrophotographic toner with a good transferability, a good flowability and a good offset resistance and also with a fixability of transferred images, which comprises a binder resin and a coloring aent, the binder resin containing:(1) a lactone-modified epoxy resin, obtained by subjecting all or a portion of secondary hydroxyl groups of epoxy compounds having hydroxy groups in the molecules to ring opening polymerization of lactone,(2) styrene-butadiene rubber, and(3) polyester resin.

Abstract: A resin composition for printed circuit board and the printed circuit board in which said resin composition is used as substrate, said resin composition comprising one or more cyclic phosphonitrile compounds represented by the general formula [I] and/or [II] and an aromatic maleimide compound and/or an aromatic amine: ##STR1## wherein at least two of R's (R.sub.1 to R.sub.

Abstract: A thermosetting resin composition comprising a special poly(p-hydroxystyrene) derivative resin and a radical polymerization initiator, and if necessary an epoxy modified polybutadiene, can provide prepregs and laminates having a low dielectric constant, a shorter signalling delay time, good heat resistance and flame retardancy and thus being suitable for producing multilayer printed circuit boards.

Abstract: The present invention provides a thermosetting resin composition comprising(a) a prepolymer of a poly(p-hydroxystyrene) derivative represented by the general formula ##STR1## wherein A is a halogen group, R.sub.1 is an alkenyl or alkenoyl group of 2 to 4 carbon atoms, m denotes a number of 1 to 4 and n denotes a number of 1 to 100,(b) an epoxy-modified polybutadiene, and(c) an aromatic maleimide compound, and a prepreg and a laminated sheet which use said resin composition.

Abstract: There are disclosed a nitrile-terminated Schiff compound represented by the formula X--Z--Y--C.tbd.N).sub.m (I) wherein n is 1 or 2, Z is --CH.dbd.N-- or --N.dbd.CH-- and Y is a divalent organic group such as phenylene and the like, and X is the same as Y when n=2 or H, lower alkyl group etc. when n=1; polymers obtained by polymerizing said Schiff compound alone or together with other monomers, and a process for preparing such a polymer therefrom.

Abstract: A thermosetting resin composition comprising a special poly(p-hydroxystyrene) derivative resin and a radical polymerization initiator, and if necessary an epoxy modified polybutadiene, can provide prepregs and laminates having a low dielectric constant, a shorter signalling delay time, good heat resistance and flame retardancy and thus being suitable for producing multilayer printed circuit boards.

Abstract: A magnetic recording medium of high durability comprising a substrate material and a magnetic layer provided on at least one surface of the substrate material, the magnetic layer comprising magnetic powder and a resinous binder, characterized in that the magnetic layer comprises further at least one compound of the formula:Rf--CH.sub.2 --R).sub.m X (I)wherein Rf is a fluorinated polyoxyalkyl group having 8 to 152 carbon atoms, R is an oxyalkylene group having 2 or 3 carbon atoms, X is a polar group such as --OH, --OCH.sub.3, -O-lower alkylene-COOH or -O-CO-lower alkylene-OH and m is an integer of not less than 1 uniformly and entirely dispersed in the magnetic layer.

Abstract: A thermosetting resin composition comprising as essential constituents (a) a prepolymer comprising a poly(p-hydroxystyrene) derivative represented by the general formula ##STR1## wherein A represents a hydrogen or halogen atom or an alkenyl or alkenoyl group having 2 to 4 carbon atoms, m represents a number in the range of from 1 to 4, and n represents a number in the range of from 1 to 100, and (b) a 1,2-polybutadiene or a derivative thereof. By using this novel resin composition and a customary equipment and procedure, it is easy to obtain a tack-free prepreg which is able to produce laminated materials of low permittivity suitable for use in multilayer printed circuit boards improved in peel strength of bonded copper foil, mechanical strengths, flame retardancy, and heat resistance, as compared to conventional printed circuit boards.

Abstract: A liquid crystal display element comprising a pair of substrates, a pair of electrodes provided on the respective substrates, at least one of which is transparent and a liquid crystal layer disposed between said substrates, the liquid crystal layer comprising a nematic liquid crystal, which exhibits a positive dielectric constant anisotropy and contains an optically active substance, the liquid crystal moleccule orientation direction in the liquid crystal layer is twisted in the range of 200.degree. to 250.degree. from the one substrate surface toward the other substrate surface so as to form a helical structure therein. A polyimide orientation film is provided between the electrodes and the liquid crystal layer. The polyimide orientation film is one made of a polyimide prepared by reacting a diamine compound having a long-chain hydrocarbon group or a diamine compound having a trifluoromethyl group with a tetracarboxylic dianhydride and causes a pretilt angle of at least 3.degree.

Abstract: A liquid crystal display element comprising a pair of substrates, a pair of electrodes provided on the respective substrates, at least one of which is transparent and a liquid crystal layer disposed between said substrates, the liquid crystal layer comprising a nematic liquid crystal, which exhibits a positive dielectric constant anisotropy and contains an optically active substance, the liquid crystal moleccule orientation direction in the liquid crystal layer is twisted in the range of 200.degree. to 250.degree. from the one substrate surface toward the other substrate surface so as to form a helical structure therein. A polyimide orientation film is provided between the electrodes and the liquid crystal layer. The polyimide orientation film is one made of a polyimide prepared by reacting a diamine compound having a long-chain hydrocarbon group or a diamine compound having a trifluoromethyl group with a tetracarboxylic dianhydride and causes a pretilt angle of at least 3.degree.