摘要:
A process for bonding lignocellulose raw materials using an isocyanate group-containing urethane-modified diphenylmethane diisocyanate mixture having a viscosity of 120 to 1000 mPas at 25.degree. C. and an isocyanate content of 15 to 33.6 percent by weight which is obtained by reacting a diphenylmethane diisocyanate mixture containing 10 to 75 percent by weight of 2,4'-diphenylmethane diisocyanate with 0.05 to 0.5 hydroxyl equivalents of a polyol per equivalent isocyanate group.
摘要:
The invention describes a process for harmonizing the reaction rates for the formation of urethane and isocyanurate groups during the preparation of polyurethane-polyisocyanurate foams by reacting organic polyisocyanates with polyols in the presence of blowing agents and salts of amines having the formula ##STR1## as catalysts, wherein R stands for an hydrogen atom or a straight chained or branched alkyl radical with 1 to 19 carbon atoms, and n and m are equal or different whole numbers from 2 to 10.
摘要:
A process for making a polyurethane which comprises reacting an organic polyisocyanate with a higher molecular weight organic polyhydroxyl compound in the presence of a catalyst having the following formula: ##STR1## wherein X is sulfur or NH and n is a whole number from 2 to 6. Also used is a catalyst which is a combination of the above-mentioned catalyst and an organic tin compound.
摘要:
The invention relates to the preparation of molded polyurethane parts having a lightfast polyurethane skin. The skin is formed by applying a reaction mixture comprising an organic polyisocyanate, a polyol, a chain extender, an aliphatic primary or secondary aliphatic diamine, and a catalyst, by a one-shot process in the absence of solvents, to the inside wall of the molding tool.The molded parts produced in accordance with this invention are used, for instance, in the automobile industry for the inside equipment of vehicles. Specifically, they may be used as cover plates for steering wheels and for lining doors. They may also be used for external equipment such as bumpers, headlight housings, and may be used in the electrical industry as housing elements.
摘要:
Intumescent, electrical installation systems which comprise an injection molding material of polyolefins or polyimides in combination with intumescent additives, the melting points of the polyolefins and of the polyimides being lower than the intumescence temperature of the intumescent additives.
摘要:
2,6-dimethylphenylmaleimide is used as a comonomer for the preparation of styrene copolymers and vinyl chloride copolymers having an increased glass transition temperature and low intrinsic coloration compared with the prior art.
摘要:
Melamine resin prepregs or melamine resin laminates which consist of a web-like fiber reinforcement which is impregnated with melamine resins which essentially comprisea) 40-85% by weight of at least partly etherified melamine resins, which are obtainable by reaction of melamine, formaldehyde and alkanols having 1 to 8 C atoms in a molar ratio of melamine formaldehyde:alkanol of 1:(5 to 6):(4 to 6), andb) 60-15% by weight of diols consisting of 25 to 75% by weight of polyester-diols and/or polyether-diols having a molecular weight of at least 400 g/mol and 75 to 25% by weight of low molecular weight diols having 2 to 12 C atoms.
摘要:
The object of this invention is a moisture-curing, storage stable, single-component polyurethane system comprising:A. a polyurethane prepolymer with a free isocyanate content of 1 to 5 percent by weight;B. a dialdimine having the formulaR[--N.dbd.CH--C(CH.sub.3).sub.2 --CH.sub.2 --O--CO--CH--(CH.sub.3).sub.2 ].sub.2in whichR is a divalent aliphatic radical with 2 to 10 carbon atoms, aliphatic radical having 4 to 10 carbon atoms and containing ether oxygen and/or lower alkylamino nitrogen atoms, cycloaliphatic radical with 6 to 15 carbon atoms oraromatic radical with 6 to 21 carbon atoms;andC. an acid catalyst selected from the group consisting of aliphatic carboxylic acids, aromatic carboxylic acids, toluenesulfonic acid, and mixtures thereof.The polyurethane systems are used as coating, sealing, casting, spackling and bonding materials.
摘要:
Flame-resistant plastics which contain trihydrazinotriazine and/or triguanidinotriazine and/or the phosphoric acid or boric acid salts thereof as flame retardants.
摘要:
Thermoplastic polyester-imides having improved mechanical properties, characterized in that they consist of recurring units of the formula I ##STR1## in which R denotes an 2,4-tolylene, 2,6-tolylene, 2,5-bis(4-phenylenethio) thiadiazole,or a 1,4-bis(phenylenethio)diphenyl sulfone radical, a process for their preparation and their use for the production of industrial components of plastic.