摘要:
Molded articles are produced in a two-stage process. In the first stage, an organic polyisocyanate is reacted with an organic compound containing at least two epoxide groups (NCO: epoxide equivalent ratio of 1.2:1 to 500:1) in the presence of a tertiary amine catalyst. This reaction is stopped when no more than 65% of the isocyanate groups have reacted by adding an alkylating sulfonic acid alkyl ester of methyl iodide and/or of dimethyl sulfate in an amount equivalent to the amount of tertiary amine catalyst present. A latent catalyst capable of being activated by heat is subsequently added to the intermediate product and the resultant mixture is heated in a mold to complete the crosslinking of the intermediate product and to form the molded article.
摘要:
This invention relates to heat-hardenable epoxide resin mixtures of at least one 1,2-polyepoxide having more than one 1,2-epoxide group per molecule, at least one cyclic carboxylic acid anhydride and at least one ammonium phosphonate or ammonium phosphate as a hardening catalyst, as well as further optional auxiliaries.
摘要:
A thermosetting reactive resin mixture is made from an organic polyisocyanate, a polyepoxide and a heat activatable catalyst. The catalyst is a tertiary or quaternary ammonium salt of an alkylating or acidic ester of an organic phosphonic acid or of phosphoric acid. The polyisocyanate and polyepoxide are used in quantities such that the equivalent ratio of isocyanate groups to epoxide groups is from 1.2:1 to 70:1. These mixtures may be heated to produce plastics having excellent heat resistance, moisture and abrasion resistance, low dielectric losses and excellent molding properties.
摘要:
This invention relates to storage stable resin reaction mixtures obtained by mixing at least one organic polyisocyanate, at least one organic compound containing at least two epoxide groups, at least one alkylating agent that inhibits the reaction of the polyisocyanate and epoxide components, and optional auxiliary agents and additives. The present invention further relates to a process for the preparation of such reaction mixtures and to their use.
摘要:
The invention relates to new, liquid-crystalline diglycidyle compounds of optionally ring-substituted 4-hydroxyphenyl 4-hydroxybenzoates, a synthesis of p-epoxypropoxy-phenyl p-epoxy-propoxybenzoate, furthermore epoxy resin mixtures containing the new diglycidyle compounds, and the use of the new diglycidyl compounds and the epoxy resin mixtures thereof in curable mixtures.
摘要:
In a construction material comprising a flexible carrier substrate impregnated or coated with a water-hardening resin, the resin contains as an additive polyether polysiloxane polyurethanes of the formula ##STR1## in which R.sup.1 is lower alkyl,m is the average number of siloxane groups in the range from 5 to 25,R is ##STR2## in which X is lower alkylene,Y is an aliphatic, cycloaliphatic, aromatic or araliphatic moiety, which is unsubstituted or substituted by further ##STR3## Z is a polyether moiety based on ethylene oxide units propylene oxide units, or both with the average number of ethylene oxide and propylene oxide units being in the range fro 10 to 100 andR.sup.2 is lower alkyl.
摘要:
The present invention is directed to an improved process for the direct preparation of polyurethane powders in a finely divided form by the reaction of polyisocyanates and isocyanate reactive compounds in a carrier phase, using interface active compounds, the improvement wherein the interface active compound used consists of at least one polymer of a urethane of (i) a long chain alkyl isocyanate and (ii) a hydroxyalkyl-acrylic or -metacrylic acid ester.
摘要:
The present invention is directed to aqueous solutions or dispersions of cationically modified polyurethanes, characterized in that the dissolved or dispersed polyurethanes(i) contain about 2 to 200 milliequivalents of incorporated ammonium groups per 100 g of solids content,(ii) contain 0 to about 25% by weight of ethylene oxide units within terminal or lateral polyether chains and(iii) contain at least 1.3% by weight, calculated as SiO.sub.3 (molecular weight=76), of built-in structural units corresponding to the formula ##STR1## wherein R', R" and R"' may be the same or different and represent hydrogen or alkyl groups containing 1 to 4 carbon atoms,the total quantity of hydrophilic structural units (i) and (ii) being sufficient to ensure the solubility or dispersibility of the polyurethanes in water and the solutions or dispersions having a pH value of 3 to 6. The present invention is also directed to a process for the preparation of these storage stable aqueous solutions or dispersions and to their use as coating compounds or for the preparation of coating compositions for any substrates.
摘要:
Liquid crystalline bis-chlorocarbonic acid esters are 4-hydroxybenzoic acid-(4'-hydroxyphenyl) esters corresponding to the following formula ##STR1## wherein R.sub.1, R.sub.2, R.sub.3 and R.sub.4 denote, independently of one another, hydrogen, a halogen atom or a C.sub.1 to C.sub.6 alkyl group. Preparation of (I) and liquid crystalline N-alkyl polyurethanes and polycarbonates prepared form (I) are other invention embodiments.
摘要:
Novel polyurethanes are prepared by reacting(a) an organic diisocyanate of formula ##STR1## wherein M represents --CH.dbd.CH--; --N.dbd.N--; --CH.dbd.N--; ##STR2## or and where R.sub.1 through R.sub.4 may be the same or different and represent hydrogen, halogen, CN, CF.sub.3 or saturated aliphatic C.sub.1 -C.sub.12 alkyl residues which may be interrupted by ether hydrogen atoms with(b) compounds of molecular weights of from between 400 and 10,000 and which contain at least two active hydrogen atoms reactive toward isocyanate groups.