Ciba-geigy Corporation

Reiner Fuchs

Kornelia Malzacher

Johannes Kaufhold

Gerd Abeler

The invention relates to a process for the preparation of a pulverulent diorganotin mercaptocarboxylate, which comprises reacting a diorganotin oxide of the formula I, ##STR1## in which R.sup.1 and R.sup.2, independently of one another, are C.sub.1 -C.sub.18 alkyl, at a temperature in the range from 35.degree. C. to 70.degree. C. in the absence of solvents and/or adsorbents with a mercaptocarboxylic acid of the formula II ##STR2## in which R.sup.3 is alkylene having 1 to 18 C atoms or is phenylene, and subjecting the reaction mixture and product during the reaction and the subsequent cooling phase to constant thorough mixing. The process products are suitable for the stabilisation of chlorine-containing polymers against the damaging effect of light, oxygen and/or heat.

Process for the preparation of diorganotin mercaptocarboxylates

The invention relates to a process for the preparation of a pulverulent diorganotin dicarboxylate, which comprises reacting a diorganotin oxide of the formula I, ##STR1## in which R.sup.1 and R.sup.2, independently of one another, are C.sub.1 -C.sub.8 alkyl, at a temperature in the range from 45.degree. C. to 70.degree. C. in the absence of solvents and adsorbents with a dicarboxylic acid of the formula II ##STR2## in which R.sup.3 is C.sub.1 -C.sub.18 alkylene, cycloalkylene having 5 to 7 carbon atoms, phenylene, C.sub.1 -C.sub.18 alkenylene or C.sub.1 -C.sub.8 alkylene substituted by 1 or 2 hydroxyl groups, or its anhydride, and subjecting the reaction mixture and the product during the reaction and the subsequent cooling phase to constant thorough mixing. The diorganotin dicarboxylates thus obtained are suitable for the stabilization of chlorine-containing polymers against the damaging effect of light, oxygen and/or heat.

Process for the preparation of diorganotin dicarboxylates

There is disclosed a process for the preparation of a powdered stabilizer mixture comprising tin stabilizers and adsorbents, which process comprises mixing and heating at least one carboxylic acid or a carboxylic anhydride, at least one organotin oxide and at least one, preferably mineral, adsorbent.

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Ober-Ramstadt, Germany

Reiner Fuchs