CS245092B1 - Stabilizing system for homopolymers and / or copolymers of vinyl chloride - Google Patents

Abstract

Stabilizing system for polyvinyl chloride and vinyl chloride copolymers, the main component of which is antimony mercaptide, and which does not show discoloration caused by sulfides at elevated temperatures.

Description

245092 3

BACKGROUND OF THE INVENTION The present invention relates to a stabilizing system for the bleach and / or the vinyl chloride copolymer, the main component of which is an antimony mercapto compound, and which does not form a polymeric sulfide type compound.

The antimony stabilizers of the Sb type (SRiCOOR2) wherein R < 1 &gt; is alkylene of C2 to C3 and R &lt; 2 &gt; is alkyl or arylalkyl of C1 to C13, as well as stabilizing systems based thereon, are effective heat stabilizers for polyvinyl chloride and vinyl chloride polymers. in addition to the reaction in which the antimony is reacted with hydrogen chloride and the mercapto residue with polyene sequences resulting from the thermal cleavage of polyvinyl chloride, a small portion of the antimony with sulfur from the mercapto group is also irreversibly reacted to form sulfides. The presence of non-white or translucent blends in their distinctive pigmented blends is different in their color, otherwise the blends of white or translucent blends result in a full range of shades of orange and red to gray-brown shades depending on local thermal stress of the mixtures, color changes are undesirable, for example, when testing known stabilization systems for antimony derivatives, the podium NSR pat. 2,704,487 or NSR Pat. 2,454,986 in white mixtures exhibited significant color changes at 373 K. Neither antimony mercaptides nor their mixtures with Ba, Ca, Cd, Zn as well as with phosphites, amines, polyols and conventional costabilizers, have no homogeneous white coloration.

This drawback does not have a stabilizing system according to the invention composed of antimony-tris-isocyanylmercaptoacetate, epoxy compound, zinc sulfate heptahydrate, tris-phenylphosphite or derivatives thereof, calcium sulfate stearate or dibutyltin amine or mixtures thereof. In the gelatinization and processing of white mixtures containing this system, the sulfide-typical color does not occur, but only after a substantially longer thermal stress or when the temperature rises to darken the material due to de-gradation. The thermal stability of the compositions corresponds to the effects of the individual components of the system. The formation of sulfides in the system according to the invention does not appear to be due to the fact that the antimony or mercaptide moiety preferably reacts with the other components of the system to form colorless or white products which form intermediate steps, with no sulfides being present among the final reaction products. all of the components of the stabilizing system of the invention are known as stabilizing or costabilizing agents and have also been described as having synergistic effects with antimony derivatives, e.g. Nos. 2,704,487 and 2,454,986; Nos. 3,919,168 and 4,391,757 have not yet described the whole system in particular its effect in suppressing sulfide formation in white and transparent compositions. Although the interaction of the individual components of the system and the mechanism of its action at higher temperatures is not known, it has been shown that none of its components can be omitted or reduced its dosage below the described range, since it affects the effect and discoloration occurs, sulfides.

The stabilizing system of the present invention may be combined with other additives which increase its thermal or light stabilizing effect, for example with metal soaps, benzophenone, triazole and amino derivatives, dialkyl tin mercaptides or carboxylates, but these are not involved in the suppression of sulfides. Example 1 Polyvinyl chloride for injection molding: S-PVC (K-value 65) 54 d. Di-2-ethylhexyl phthalate 38 d. Chloroparaffin 2 d. Limestone micronized 1.75 d. Titanium white 0.9 d. Azodicarbonamide 0.15 d. wax E 0.2 d. Sb-tris-isooctylmercaptoacetate 0.55 d. epoxy resin / equivalent 0.5 / 0.5 d. ZnSO4.7 H 2 O 0.1 d. tris-nonylphenylphosphite 0.5 d. dibutyltin maleate 0.8 d Ca-stearate 0.55 d

Plastisol for casting with composition: micrususpension PVC (K-75) 20 d. Emulsion PVC (K-70) 20 d. Suspension PVC (K-65) 10.5 d. Di-2-ethylhexyl phthalate 40 d. 9 d. Titanium dioxide 3 d. Partial fatty glyceride 1 d. Zn-octoate 0.8 d. Silicone oil 0.08 d. Sb-tris-isooctylmercaptoacetate 0.6 d. Epoxy resin / equivalent 0.5 / 0.4 d. ZnSCU. Tris-phenylethylphenyl phosphite 0.4 d. Dibutyltin maleate 0.2 d.

Claims (1)

SUBJECT Stability system for homopolymers and / or copolymers of vinyl chloride, characterized in that it consists of 10 to 70% by weight of antimony-tris-isooctyl mercaptoacetate, furthermore from 5 to 50% by weight of an epoxy compound having a molecular weight of 150 to 3500, containing at least one oxyran group, further from 1 to 10 weight percent of zinc sulfate heptahydrate, from 10 to 10 INVENTION 40% by weight of an organophosphite of the formula wherein R is hydrogen or a C2 to C18 alkyl or arylalkyl, further from 10 to 50% by weight of dibutyltin maleate or calcium stearate or a mixture thereof.