Ciba-geigy Corporation

Karl Mechera

Abdul-Cader Zahir

Sheik A Zahir

Daniel Wagner

A process for producing as end-product a heat-hardenable mixture forming thermosetting resin, e.g., a reactive hot-melt adhesive, comprises preparing a first pre-mixture by introducing a meltable heat-hardenable solid resin and liquid resin, flexibilizer, adhesion-promoter and/or plasticizer into a mixing zone in which the components are melted together; preparing a second pre-mixture by mixing with each other a heat-activatable hardener and thixotropic agent, hardening accelerator and/or electrical conductivity-imparting additive; introducing the melt into an extruding zone; and introducing the pulverulent pre-mixture into the extruding zone downstream of the melt-intake for mixing with the first pre-mixture at a temperature below said hardening temperature and in such amount that the content of the second pre-mixture in the end-product ranges from 10 to 50, preferably from 20 to 30 weight-% air occlusions in the melt and the extruded end-product being avoided.

Process and plant for manufacturing heat-hardenable meltable mixtures

Compounds of formula I or II ##STR1## in which formulae R.sup.1 and R.sup.2 are each independently of the other hydrogen, alkyl, alkenylmethyl, cyclohexyl, phenyl, benzyl or tolyl, or are a --CH.sub.2 --CHR.sup.3 --CH.sub.2 --S--H group, R.sup.3 and R.sup.4 are each independently of the other hydrogen or methyl, X is alkylene, --S--, --SO--, --SO.sub.2 -- or substituted alkylene, R.sup.5 and R.sup.6 are each independently of the other hydrogen or alkyl, R.sup.8 is hydrogen, alkyl, alkenylmethyl or phenyl, and wherein n is an integer from 1 to 10, can be used as hardeners for epoxy resins. The compositions containing epoxy resins and these hardeners are particularly suitable for use as adhesive formulations. The cured products have good moisture resistance.

Compositions comprising an epoxy resin and mercaptan-containing

Compounds of formula I or II ##STR1## in which formulae R.sup.1 and R.sup.2 are each independently of the other hydrogen, alkyl, alkenylmethyl, cyclohexyl, phenyl, benzyl or tolyl, or are a --CH.sub.2 CHR.sup.3 --CH.sub.2 --S--H group, R.sup.3 and R.sup.4 are each independently of the other hydrogen or methyl, X is alkylene, --S--, --SO--, --SO.sub.2 -- or substituted alkylene, R.sup.5 and R.sup.6 are each independently of the other hydrogen or alkyl, R.sup.8 is hydrogen, alkyl, alkenylmethyl or phenyl, and wherein n is an integer from 1 to 10, can be used as hardeners for epoxy resins. The compositions containing epoxy resins and these hardeners are particularly suitable for use as adhesive formulations. The cured products have good moisture resistance.

Growing community of inventors

Muttenz, Switzerland

Karl Mechera