Abstract: A photocurable resin composition capable of producing a three-dimensional object which has excellent dimensional accuracy with a small volume shrinkage factor and excellent heat resistance with a high heat distortion temperature as well as excellent transparency and mechanical properties. This composition comprises at least one imidated acrylic compound (i) represented by the following formula: wherein R1 is an alicyclic group, an aromatic group or an aliphatic group which may be substituted, R2 is a residual group of amino alcohol, R3 is hydrogen atom or methyl group, and n is 1 or 2; (ii) a radical polymerizable compound and/or a cationic polymerizable compound other than the above imidated acrylic compound; and (iii) a photopolymerization initiator. The weight ratio of the imidated acrylic compound to the radical polymerizable compound and/or cationic polymerizable compound is 80:20 to 10:90.

Abstract: A photohardenable resin composition comprising (A) a urethanated acrylic compound represented by formula (I): (A)a—C—(R)4−a wherein R is H or alkyl; a is 3 or 4; and A represents a group of formula (II): wherein D represents —CH2CH2O—, —CH2CH(CH3)O—, —CH2CH2COO— or —(CH2)6COO—; E represents —CH2CH2O—, —CH2CH(CH3)O—, —COCH2CH2O— or —CO(CH2)6O—; G represents a diol or triol residual group; J represents a divalent or trivalent and substituted or unsubstituted hydrocarbon group; L represents —(CH2CH2O)h— (h: integer of 1 to 4), —(CH2CH(CH3)O)j— (j: integer of 1 to 4), or —(CH2CH2O)k—(CH2CH(CH3)O)m— (k, m: integer of 1 to 3 (k+m=2, 3 or 4); b, c, and d are each 0 or 1 (b+c+d=1, 2 or 3); e is 0, 1 or 2; f is 0 or 1 (e+f=1 or 2); and g is 1 or 2, and (B) a radical polymerizable compound at a (A) : (B) r

Abstract: There is provided a photocurable resin composition comprising (A) an urethane acrylate having three or four acrylate groups in the molecule, (B) a radical polymerizable compound different from the above urethane acrylate; and (C) a photopolymerization initiator, the weight ratio of the urethane acrylate (A) to the radical polymerizable compound (B) being 80:20 to 10:90; and a production process thereof. The said photocurable resin composition can provide moldings and stereolithographed objects having excellent dimensional accuracy with a small volume shrinkage factor at the time of photo-curing and excellent heat resistance with a high thermal deformation temperature as well as excellent transparency and mechanical properties such as tensile strength.

Abstract: A resin composition for forming a three-dimensional object by optical stereolithography, which contains 5 to 65 vol % of aluminum oxide fine particles having an average particle diameter of 3 to 70 &mgr;m and 5 to 30 vol % of whiskers having a diameter of 0.3 to 1 &mgr;m, a length of 10 to 70 &mgr;m and an aspect ratio of 10 to 100, the total content of the aluminum oxide fine particles and the whiskers being 10 to 70 vol %. According to the resin composition for forming a three-dimensional object by optical stereolithography, a high-quality three-dimensional object by optical stereolithography that has high heat resistance with a high heat distortion temperature and high rigidity with a high flexural modulus and that is free from a dimensional change on account of a low linear thermal expansion coefficient even when temperature varies can be obtained by optical stereolithography with high dimensional accuracy.

Abstract: There is provided a photocurable resin composition comprising (A) an urethane acrylate having three or four acrylate groups in the molecule, (B) a radical polymerizable compound different from the above urethane acrylate; and (C) a photopolymerization initiator, the weight ratio of the urethane acrylate (A) to the radical polymerizable compound (B) being 80:20 to 10:90; and a production process thereof. The said photocurable resin composition can provide moldings and stereolithographed objects having excellent dimensional accuracy with a small volume shrinkage factor at the time of photo-curing and excellent heat resistance with a high thermal deformation temperature as well as excellent transparency and mechanical properties such as tensile strength.

Abstract: A resin composition for stereolithography and a process for producing a three-dimensional object using the same. The resin composition comprises (1) a liquid photohardenable resin composition containing at least one of photo-polymerizable compounds and a photosensitive polymerization initiator, and (2) at least one of radiation energy absorbers in an amount of from 0.001 to 1.0% by weight based on the total amount of the liquid photohardenable resin composition (1).

Abstract: A resin composition for three-dimensional object by optical stereolithography containing a colorant, such as carbon black, in an amount of 0.05 to 0.5% by weight can provide a colored three-dimensional object which has excellent physical and mechanical properties such as dimensional accuracy, shape stability, hardness and tensile strength and elastic modulus in tension, as well as light-shielding properties, gives a massive impression and is colorful at a high optical shaping speed and in a good productivity.

Abstract: A photocurable resin composition comprising (A) at least one urethane di- or triacrylate, which is a novel compound, (B) a radical polymeriable compound, and (C) a photopolymerization initiator, the weight ratio of the urethane acrylate (A) to the radical polymerizable compound (B) being 65/35 to 25/75; a method of producing a photo-cured object by photo-curing the above composition; a vacuum casting mold obtained by the above method; and a vacuum casting method using the above mold.

Abstract: A mold having a cavity for shaping a three-dimensional object, which comprises a photocured resin of a photocurable resin composition comprising(A) a liquid photocurable resin, and(B) at least one reinforcing agent selected from the group consisting of inorganic solid particles having an average particle diameter of 3 to 70 .mu.m and a whisker having an average diameter of 0.3 to 1.0 .mu.m, a length of 10 to 70 .mu.m and an aspect ratio of 10 to 100 and optionally, in which the inner surface of the cavity is covered by a solid film having a thickness of 5 to 1000 .mu.m.

Abstract: Photocurable resin compositions capable of producing plastic molds with improved durability by stereolithography in the presence of a photoinitiator includes unsaturated urethane of a specified kind, vinyl monomer of a specified kind, a filler and salt of phosphoric acid ester of specified kinds at a specified ratio.

Abstract: A resin composition for stereolithography and a process for producing a three-dimensional object using the same. The resin composition comprises (1) a liquid photohardenable resin composition containing at least one of photo-polymerizable compounds and a photosensitive polymerization initiator, and (2) at least one of radiation energy absorbers in an amount of from 0.001 to 1.0% by weight based on the total amount of the liquid photohardenable resin composition (1).

Abstract: A plastic mold is produced by first repeating the process of forming a layer of a photocurable resin composition of a specified kind and exposing it to actinic radiation to at least partially photocure it to produce a photocured layered structure having a glass transition temperature of 70.degree.-120.degree. C. This structure is then subjected to a post-cure process at a temperature high than the glass transition temperature by 30.degree.-100.degree. C. Plastic molds made by this method have superior heat distortion temperature and tensile elastic modulus.

Abstract: A resin composition for production of a three-dimensional object by curing, which comprises a) a liquid photocurable resin, and b) a reinforcing agent selected from an inorganic solid particle having an average particle diameter of 3 to 70 .mu.m, whisker having an average particle diameter of 0.3 to 1.0 .mu.m, a length of 10 to 70 .mu.m and an aspect ratio of 10 to 100, and a combination of these.

Abstract: A process for producing an aromatic polyamide film, which comprises drawing an undrawn aromatic polyamide film biaxially at a draw ratio of at least 1.5 in a solvent mixture consisting of (a) 5% to 75% by weight of a good solvent of the aromatic polyamide and (b) 25% to 95% by weight of a non-solvent of the aromatic polyamide, and heat treating the drawn film, which contains at least 1% by weight, based on the weight of the film, of a good solvent of said aromatic polyamide, at a temperature of not lower than 150.degree. C.An m-phenyleneisophthalamide polymer film having extremely excellent dimensional stability under moist conditions, which film has a density d of from 1.35 to 1.41 g/cm.sup.3 and principal refractive indices n.sub..alpha., n.sub..beta. and n.sub..gamma. (n.sub..alpha. >n.sub..beta. >n.sub..gamma.

Abstract: There is provided an aromatic polyamide composition, which comprises (a) a polyamide, the recurring structural units of which are substantially totally aromatic, (b) an organic amide solvent, and (c) one or more salts selected from chlorides and bromides of an alkali metal, an alkaline earth metal or ammonium. The amounts of the polyamide and the organic amide solvent are in the ranges of 30 to 50% and 70 to 50% by weight, respectively, based on the total weight of the polyamide and the organic amide solvent. The amount of the salt is defined by the formulae:in the case where 30.ltoreq.x.ltoreq.33.6, y.gtoreq.10, andin the case where 33.6<x.ltoreq.50, y>2.8x-84wherein "x" is the amount in % by weight of the polyamide based on the total weight of the polyamide and the organic amide solvent, and "y" is the amount in % by mole of the salt based on the polyamide. The polyamide composition is useful for melt-shaping films, fibers and other shaped articles.

Abstract: A wholly aromatic polyamide fiber material having an excellent resistance to chemicals, comprises wholly aromatic polyamide fibers each covered with a coating of a fluorine-containing polymeric resin which coating has been derived from an aqueous emulsion of the fluorine-containing polymer resin.

Abstract: Aromatic polyamide film, having an excellent thermal resistance and a high dielectric breakdown strength, which comprises an aromatic polyamide containing repeating units of the formula----NH--Ar.sub.1 --CO----or----NH--Ar.sub.1 --NHCO--Ar.sub.2 --CO----and cross-linked with a cross-linking compound having at least one radical selected fromR.sup.1 --C(R.sup.2).dbd.C--CH.sub.2 (R.sup.3)--,R.sup.1 --C(R.sup.2).dbd.CR .sup.3 --,R.sup.1 --C(R.sup.2).dbd.C(R.sup.3)--COO--andR.sup.1 --C(R.sup.2).dbd.C(R.sup.3)--CONH--,or another cross-linking cyanuric or isocyanuric acid compound, by means of heat, ultraviolet rays or electron beam.

Abstract: An aromatic polyamide composition usable for producing shaped articles, for instance, filaments, comprises the components of an aromatic polyamide resin (P), a polar amide solvent (S) and an auxiliary solvent (H) consisting of a halogenated hydrocarbon, for example, dichloromethane and dichloroethane, the proportions of the components (P), (S) and (H) being on or within a quadrilateral A C D E defined by the co-ordinates:A (P 5.0, S 30.0, H 65.0 )C (P 45.0, S 30.0, H 25.0)D (P 57.0, S 38.0, H 5.0) andF (P 5.0, S 90.0, H 5.0).The composition also contains a solubility enhancing agent consisting of one or more inorganic halide, such as alkali metal halides, alkaline earth metal halides and ammonium halides, in amount of from 5 to 60%, based on the weight of the polyamide resin.

Abstract: A liquid coating composition containing vinyl fluoride-hexafluoropropylene resin which has superior storage stability even in high concentrations and can form a coating layer having outstandingly superior mechanical strength properties such as tensile strength, initial Young's modulus or hardness and superior transparency and gloss. The liquid coating composition comprises a vinyl fluoride-hexafluoropropylene copolymer having an inherent viscosity of 0.2 to 2 and composed of 5 to 50 mol % of units derived from hexafluoropropylene, 0 to 10 mol % of units derived from a third component and the remainder being units derived from vinyl fluoride, and specified solvent, the amount of said copolymer being 1 to 50% by weight, as solids content, based on the weight of the composition.

Abstract: A method for preparing a vinyl fluoride-hexafluoropropylene copolymer resin having an inherent viscosity of 0.2 to 2 suitable for use in liquid coating compositions in the presence of an organic peroxide initiator, a fluorine-containing surface active agent, a dispersing agent and/or a molecular-weight regulating agent.Liquid coating compositions containing the vinyl fluoride-hexafluoropropylene resin having superior storage stability even in high concentrations and can form a coating layer having outstandingly superior mechanical strength properties such as tensile strength, initial Young's modulus or hardness and superior transparency and gloss.