Abstract: A curable mixture which includes at least (a) 10 to 100 percent by weight, in relation to the sum of the components (a) and (b), of at least one bi- or polyfunctional aromatic cyanate or a prepolymer formed from at least one bi- or polyfunctional aromatic cyanate or a mixture formed from the abovementioned cyanates and/or prepolymers; (b) 0 to 90 percent by weight, in relation to the sum of the components (a) and (b), of at least one mono-, bi- or polyfunctional epoxy resin; (c) 0.5 to 30 percent by weight, in relation to the sum of the components (a) and (b), of at least one mono-, bi- or polyfunctional aromatic amine; and (d) 0 to 5 percent by weight, in relation to the sum of the components (a) and (b), of at least one catalyst from the group consisting of transition metal compounds and boron trihalides.

Abstract: Described are prepolymer compositions on the basis of novolak cyanates of the general formula wherein n is a number from 0 to 20 and the radicals R are identical or different and represent hydrogen or methyl. The compositions contain: 30 to 90 parts by weight of a prepolymer from novolak cyanates (I) wherein R=hydrogen (Ia) and 10 to 70 parts by weight of novolak cyanates (I) wherein R=methyl (Ib), and optionally highly disperse silicon dioxides and/or particulate or fibrous fillers. The inventive compositions are solid at normal temperature and can be ground to flowable powders. They have excellent stability when stored and are easy to process and especially suitable for use as the resin component in base materials for printed circuits on resin-bound abrasive products.

Abstract: A curable mixture which includes at least (a) 10 to 100 percent by weight, in relation to the sum of the components (a) and (b), of at least one bi- or polyfunctional aromatic cyanate or a prepolymer formed from at least one bi- or polyfunctional aromatic cyanate or a mixture formed from the abovementioned cyanates and/or prepolymers; (b) 0 to 90 percent by weight, in relation to the sum of the components (a) and (b), of at least one mono-, bi- or polyfunctional epoxy resin; (c) 0.5 to 30 percent by weight, in relation to the sum of the components (a) and (b), of at least one mono-, bi- or polyfunctional aromatic amine; and (d) 0 to 5 percent by weight, in relation to the sum of the components (a) and (b), of at least one catalyst from the group consisting of transition metal compounds and boron trihalides.

Abstract: The unsaturated oligophenol cyanates of the general formula [A—]n[B—A—]xB[—A]m   (I) in which A is a group of formula: and B is a group of formula: where R1, R2 and R3 are each hydrogen or a bond with a group B, there being either one or two bonds with group B; and both R4 and R4′ as well as R5 and R5′ separately or jointly represent a direct bond or hydrogen and a bond with a group A, there being either one or two bonds with A. The indices m and n are 0 or 1 but not both 1 at the same time and x is a whole number between 0 and 10, where at least one of the numbers, m, n and x is not 0. The unsaturated oligophenol cyanates can be prepared by reacting the corresponding oligophenols with cyanogen chloride. The have a low viscosity and owing to their double bonds are able to undergo free-radical polymerization.

Abstract: Described are prepolymer compositions on the basis of novolak cyanates of the general formula 1

Abstract: Blends of novolaks and cyanates, such blends can be thermally hardened in a short time and without using a catalyst and have an excellent storage stability. The resins obtained by the blends can be used as binding agents in abradants or as chip coverings or printed circuit boards (PCB) in electronics.

Abstract: Arylcyanates are produced by reacting polyvalent phenols with a halogen cyanogen in the presence of a tertiary amine and a nonaqueous solution at high temperature. The tertiary ammonium halogenide obtained as a secondary product is fully or partially removed by processing the reaction mixture with cationic and anionic exchanger, whereby arylcyanates with a particularly low halogenide content are obtained.

Abstract: A process for the production of aryl cyanates of the general formula I: ##STR1## A phenol of the general formula II: ##STR2## a tertiary amine and cyanogen chloride, of which at least one of the three components is present as a solution in an organic solvent, are fed essentially simultaneously and continuously at a temperature of -20.degree. C. to 0.degree. C. and in a molar ratio of cyanogen chloride to the reactive hydroxy groups of the phenol of 1.0:1.0 to 1.2:1.0 in a cooled loop reactor, so that the reaction components, before they come in contact with one another, are prediluted by the reaction mixture circulating in the loop reactor. Simultaneously, a stream of the reaction mixture corresponding to the fed volume of the reaction components is drawn off from the circulation.