Lonza Ag

Lonza Inc.

Alessandro Falchetto

Ulrich Daum

Paul Hanselmann

Sajal Das

Brigitta Heyl-Frank

Martin Gmur

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.

Hardenable cyanate compositions

Described are prepolymer compositions on the basis of novolak cyanates of the general formulawherein 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.

Novolak cyanate-based prepolymer compositions

Unsaturated oligophenol cyanates

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.

Novolak cyanate blends

Method for producing arylcyanates

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.

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Domodossola, Italy

Alessandro Falchetto