摘要:
A process for the manufacture of partially dehydrated organic polymer polyol dispersions from the reaction of polyhydroxyl compounds and aqueous polymer dispersions wherein the problem of excessive viscosity is overcome by mixing the reactants with a recycled partially dehydrated polyol polymer dispersion, removing water from the reaction mixture, removing a portion of the partially dehydrated polyol polymer dispersion, and recycling the remainder.
摘要:
Stable melamine-polyoxyalkylene polyether polyol dispersions are prepared by the in situ reduction of melamine particles wherein 90 percent of the melamine particles have a particle size of less than 10 microns. Stabilizers for the melamine-polyol dispersion are selected from the group consisting of(a) silicic acids and silicates,(b) salts of perfluorinated alkyl carboxylic acids having 4 to 20 carbon atoms, salts of alkyl sulfonic acids and perfluorinated alkylsulfonic acids having 4 to 20 carbon atoms and polyperfluoroether polyols having molecular weights of 300 to 6000, and(c) salts of fatty alcohol sulfates having 6 to 30 carbon atoms.These dispersions are useful for the preparation of polyurethane foams.
摘要:
The invention relates to a process for the manufacture of reinforced polyurethane foams based on the reaction of organic polyisocyanates and polyols in the presence of filler dispersions. These dispersions are prepared by in situ crushing of the filler in the polyisocyanate or polyol to a particle size of less than 7 microns.
摘要:
Thermoplastic molding materials containing a mixture ofA. a heat-stable polymer, e.g. a polyether sulfone or polysulfone, which does not contain any reactive groups, andB. a heat-stable polymer which contains reactive groups, preferably nitrile or thioaryl groups and/or sulfur bridges,can be processed to moldings, which can be crosslinked, for example by being heated at above 200.degree. C., so that the plastic matrix becomes virtually insoluble.
摘要:
Fiber-reinforced materials are produced by a process in which a heat-stable thermoplastic aromatic polyether A containing reactive groups, preferably nitrile groups and/or sulfur bridges and/or arylthio or alkylthio groups, if required together with a heat-stable thermoplastic polymer B which does not contain any reactive groups, is applied onto reinforcing fibers, the resulting semi-finished product is shaped, and the plastic matrix in the molding obtained is crosslinked so that there is virturally no increase in its glass transition temperature although the amount of soluble material is decreased to less than 60%, determined by extraction in boiling dichloromethane for one hour.
摘要:
Fiber-reinforced materials are produced by a process in which a heat-stable thermoplastic aromatic polyether A which contains reactive groups, preferably nitrile groups and/or sulfur bridges and/or arylthio or alkylthio groups, if necessary together with a heat-stable thermoplastic polymer B which does not contain any reactive groups, is applied onto reinforcing fibers, the resulting semi-finished product is molded and, in the molding obtained, the plastic matrix is crosslinked so that the glass transition temperature increases and it becomes virtually insoluble.
摘要:
Fiber-reinforced materials are produced by impregnating continuous filaments with a melt of a polyarylene sulfide ketone, preferably one having a reduced viscosity .eta..sub.red of from 0.1 to 0.5 [dl.g.sup.-1 ], shaping the resulting semi-finished product to give a finished article and heating the latter for not less than 15 minutes at above the crystallite melting point of the polyarylene sulfide ketone, the latter undergoing crosslinking and its glass transition temperature Tg increasing by not less than 5.degree. C.
摘要:
The invention relates to a process for the preparation of polyurethane or polyurethane-polyurea molded parts by reacting organic polyisocyanates, polyols and chain extenders in the presence of monocyclic amidines having the formula ##STR1## as catalyst or catalyst mixtures of monocyclic amidines having the formula (I) and (a) tertiary amines, (b) metal salts having the formula Me X.sub.n Y.sub.m (II), and/or (c) optionally-substituted aliphatic carboxylic acids. R.sup.1 and R.sup.2, Me, X, Y, n, and m are defined herein.
摘要:
Vinyl ester resins possess unsaturated terminal groups and are based on polyphenols of the formulaC(ArOH).sub.m (R').sub.p --(CR.sub.2).sub.n --C(ArOH).sub.m (R").sub.p (I)or(ArOH)--CH.sub.2 --Ar--CH.sub.2 --[(ArOH)--CH.sub.2 --Ar--CH.sub.2 ].sub.n --(ArOH) (II)wherein R, R' and R" may be identical or different and are each H or CH.sub.3, Ar is phenylene which is unsubstituted or substituted by methyl or methoxy, n is 0, 1 or 2, m is 1 or 2 and p is 3-m.
摘要:
The invention relates to a process for the preparation of elastomeric molded parts having urethane or urethane and urea linkages which comprises reacting(a) an organic polyisocyanate,(b) a polyhydroxyl compound selected from the group consisting of(i) polyester polyols with molecular weights of 1000 to 3000 and hydroxyl numbers of 170 to 35 produced by polycondensation of organic dicarboxylic acids and a polyol mixture of at least 3 polyols;(ii) polyether polyols having terminal ester groups, molecular weights of 1000 to 8000 and hydroxyl numbers of 170 to 15; and(iii) mixtures thereof;(c) a chain extenderwherein components (a) through (c) are processed according to reaction injection molding techniques in open or closed molds.The reaction is preferably carried out as a one-shot process and may also be carried out in the presence of blowing agents (d), auxiliaries (e), and additives (e).The non-cellular and/or microcellular elastomeric molded parts produced according to the method of this invention are particularly well suited for use in the automobile industry, for example, as bumper covers and body parts such as fenders, spoilers, wheel well expansions as well as engineering housing parts and runners. The cellular foams are used, for example, as shoe soles, armrests, headrests, safety coverings in the passenger compartment in automobiles as well as motorcycle and bicycle seats, seat cushions and cover layers in composite foams.