Abstract: A high electrical power-resistant radiowave absorbing body is disclosed comprising a carbon fiber fabric embedded in inorganic cement. The fabric can be woven or nonwoven. Carbon fiber fabrics of different densities can be used to develop a concentration gradient to enable wide frequency band absorption.

Abstract: A safety fuel tank for automobiles and the vehicles, wherein substantially skeletal reticulated flexible polyurethane foam is integrally foamed, is produced by reacting a mixture of (a) poly(oxypropylene-oxyethylene)polyetherpolyol having 51-98% by weight of ethylene oxide component and (b) poly(oxypropylene-oxyethylene)polyetherpolyol having not less than 51% by weight of propylene oxide component as the polyhydroxyl compound with an organic polyisocyanate in the presence of a catalyst, a foaming agent, a surfactant and an additive in a fuel tank.

Abstract: A method of producing flexible polyether polyurethane foams, which have a substantially skeletal reticulated structure, is disclosed. When the flexible foam is produced by reacting a polyhydroxyl compound with an organic polyisocyanate in the presence of a blowing agent by one-shot process, a catalyst and other additives, a mixture of (a) poly(oxyethylene-oxypropylene)polyether polyol containing 51 to 98% by weight of ethylene oxide component and (b) poly(oxyethylene-oxypropylene)polyether polyol containing not less than 51% by weight of propylene oxide component is used as the polyhydroxyl compound.

Abstract: A process for producing flame-resistant foam resins is disclosed. The flame-resistant foam resin is produced by reacting an organic polyisocyanate with urea.

Abstract: A moisture- and heat-resistant flexible polyurethane foam, which is free from lowering of the foam hardness due to moisture absorption during or after the production of the foam under a high temperature and high humidity condition and free from development of scorch during the production of the foam, can be obtained by adding an amino acid or an amino acid analogous compound to a raw material mixture, and foaming the resulting mixture.

Abstract: The flexible polyurethane foams having high flame resistance and smoke resistance can be produced by reacting a polyhydroxyl compound and a polyisocyanate with a urea derivative selected from the group consisting of(a) a compound represented by the general formula ##STR1## wherein at least one of R.sub.1, R.sub.2, R.sub.3 and R.sub.4 represents hydroxylalkyl, alkoxyalkyl, alkyl and aryl groups and the remainder represents hydrogen atom, and(b) a urea-formaldehyde condensation product in the presence of a catalyst, a surfactant and a blowing agent.These polyurethane foams can easily provide the favorable foam sheets by compression-molding these foams under heating.

Abstract: A method of producing polyurea foams is disclosed. The polyurea foam is produced by reacting an organic polyisocyanate with water in the presence of urea or by reacting a crude tolylene diisocyanate or a mixture of crude tolylene diisocyanate and crude diphenylmethane diisocyanate as an organic polyisocyanate with water in the presence of an amine catalyst, a silicone surfactant and, if necessary, a tin catalyst.

Abstract: Flexible urethane foams having a low density and capable of preventing spontaneous combustion during production and storage are produced by compounding 5.0-12.0 parts by weight based on 100 parts by weight of polyhydroxylcompounds, of water and not less than 0.1 part by weight of aromatic amine antioxidant, further preferably not less than 0.01 part by weight of phosphorous acid triesters in the usual combination of polyhydroxyl compounds, polyisocyanates, water, catalysts, surfactants, foaming agent and other additives.

Abstract: According to the present invention polyurethane foams, can be obtained as flame resistant and non-corrosive product. The invention specifies the foaming of raw material mixture comprising polyhydroxyl compound, polyisocyanate, blowing agent and etc. to be carried out in the presence of melamine powder added thereto as novel flame retardant, the final products being inexpensive and suitable to be used as structural material, etc.

Abstract: The flexible polyurethane foams having high flame resistance and smoke resistance can be produced by reacting a polyhydroxyl compound and a polyisocyanate with a urea derivative selected from the group consisting of(a) a compound represented by the general formula ##STR1## wherein at least one of R.sub.1, R.sub.2, R.sub.3 and R.sub.4 represents hydroxylalkyl, alkoxyalkyl, alkyl and aryl groups and the remainder represents hydrogen atom, and(b) a urea-formaldehyde condensation product in the presence of a catalyst, a surfactant and a blowing agent.These polyurethane foams can easily provide the favorable foam sheets by compression-molding these foams under heating.

Abstract: A flame-resistant and smoke-retardant polyurethane foam is produced by reacting a polyisocyanate with a polyhydroxyl compound in the presence of an alkaline earth metal salt of a carboxylic acid and a foaming agent.

Abstract: An excellent flame- and smoke-resistant polyurethane foam is produced by reacting a polyol, a polyisocyanate and an amine-carbamate of primary or secondary amine having hydroxyl group in the presence of a catalyst and a surfactant.

Abstract: A flame- and smoke-retarded, non-shrinkable flexible polyurethane foam is prepared by reactingA. a polyol having at least two active hydrogen atoms and a molecular weight of from 1,000 to 10,000,B. a low molecular weight polyhydroxyl compound having a molecular weight of from 60 to 700,C. a polyisocyanate andD. an ammonium compound which generates ammonia gas at a temperature below 100.degree. C,wherein the equivalent weight ratio of (B) to (A) is ranging from 0.5 to 2.0 and the amount of (D) based upon 100 parts by (A) ranges from 0.5 to 10 parts by weight.

Abstract: An excellent flame- and smoke-resistant flexible polyurethane foam is produced by reacting a polyisocyanate with a mixture ofA. polyether polyol containing secondary hydroxyl group of at least 50 mol% of total hydroxyl content and having a number average molecular weight of 3,000-6,000 andB. a low molecular weight polyhydroxyl compound, an equivalent weight ratio of said low molecular weight polyhydroxyl compound (B) to said polyether polyol (A) being 0.5-2.0, if desired, the flame retardancy of the foam may be enhanced by the addition of a small amount of flame retardant.

Abstract: A thermoplastic and organic solvent-soluble poly(amide-imide) elastomer having a number average molecular weight ranging from 10,000 to 100,000, prepared by reacting (1) an acid anhydride functional polymer, represented by the following formula ##STR1## or a mixture of said acid anhydride functional polymer (1) and a tetracarboxylic acid dianhydride, with (2) a dicarboxylic acid dihydrazide in the presence of an aprotic dipolar solvent at a temperature ranging from -10.degree. C to 30.degree. C.

Abstract: The present invention relates to a process for manufacturing a new elastomer having high elasticity, mechanical strength and processability from epoxy compounds, trimellitoyl-functional polymers and a third element. The third element is any of acid anhydride compounds having a molecular weight lower than 700, and having at least one acid anhydride group, such as maleic, phthalic, succinic, adipic, trimellitic, pyromellitic, and benzophenone tetracarboxylic anhydrides. It is, according to another aspect, an improvement of physical properties, especially tensile and tear strengths of the elastomer manufactured by reacting said first two elements according to the copending application Ser. No. 143,643, filed May 14, 1971, while keeping desirably low exothermicity and thermal contraction during the curing.

Abstract: A curable epoxy resin composition containing an epoxy resin and, as a curing agent, 3,9-bis(2-hydrazidoethyl)-2,4,8,10-tetraoxaspiro-[5,5]-undecane, as well as the cured resins produced from such composition, the curable resin being useful for paints, adhesives, and molded articles.

Abstract: A flexible elastomer resin having an improved impact resistance and strength is produced by reacting an acid anhydride group functional polymer, which is prepared by reacting a hydroxyl group functional polymer having a number average molecular weight of 400 to 10,000 and containing at least two hydroxyl groups at the end or the side chain with a tricarboxylic acid anhydride monohalide, with at least one nitrogen compound having polyfunctional active hydrogens and at least one epoxy resin having at least one epoxy group.

Abstract: A stiffener, 3,9-(2-hydrazidoethyl)-2,4,8,10-tetraoxaspiro-[5,5]-undecane, is used for improving physical properties of rubber compositions.

Abstract: Aldehyde functional polymers having a molecular weight of about 500 to 50,000 and containing aldehyde functional groups at both ends and/or on side chains of the molecule are produced by subjecting some of the double bonds in a high polymer containing olefinically unsaturated double bonds to ozone-decomposition by ozone-containing gas and reducing the ozone-decomposition products by means of a trivalent phosphorus compound as a reducing agent into substantially only aldehyde functional groups.