CS245092B1 - Stabilization system for vinyl chloride's homopolymers and/or copolymers - Google Patents

Abstract

Stabilization system for polyvinyl chloride and vinyl chloride copolymers of which the principal the component is antimony mercaptide, and which does not show color at elevated temperature, sulfides.

Description

(54) Stabilization system for vinyl chloride homopolymers and / or copolymers

A stabilizing system for polyvinyl chloride and vinyl chloride copolymers, the main constituent of which is antimony mercaptide and which does not show sulphide coloration at elevated temperature.

The invention relates to a stabilization system for homopolymers and / or copolymers of vinyl chloride, the main component of which is an antimony mercapto compound and which does not form colored sulfide type compounds during the thermal stress of the polymer.

The antimony stabilizers of the Sb type (SiOCOOR ² ) in which R ¹ is alkylene C 2 -C 8 and R ² is alkyl or arylalkyl C 1 -C 13, as well as their stabilization systems, are effective thermal stabilizers for polyvinyl chloride and vinyl chloride copolymers. is that, in addition to reactions in which antimony reacts with hydrogen chloride and a mercaptide residue with polyene sequences resulting from the thermal cleavage of polyvinyl chloride, a simultaneous irreversible reaction of a small portion of antimony with sulfur from the mercapto group to form sulphides is present. The presence of pigmented color blends does not affect their presence, but the white or transparent blend forms a wide variety of shades ranging from vivid orange and red to greyish shades depending on the local thermal stress of the mixture. When testing known stabilization systems based on antimony derivatives, for example according to NSR Pat. No. 2,704,487 or German Pat. 2,454,986 in white blends showed significant color changes at temperatures above 373 K. Neither the antimony mercaptoderivatives nor their mixtures with oxides or salts of Ba, Ca, Cd, Zn as well as with phosphites, amines, polyols and common co-stabilizers gave a homogeneous white coloration.

Said drawback does not have a stabilizing system according to the invention, composed of antimony tris-isoxtyl mercaptoacetate, an epoxy compound, zinc sulfate heptahydrate, trlsphenylphosphite or derivatives thereof, calcium stearate or dibutyltin maleate or a mixture thereof. The gelling and processing of the white mixtures containing this system does not lead to a coloration typical of sulphides, but only at a substantially longer thermal stress or at a higher temperature the material darkens due to degradation. The thermal stability of the mixture corresponds to the sum of the effects of the individual components of the system. The sulfides of the system of the present invention are not likely to occur because the antimony or mercaptide moiety preferably reacts with the other components of the system to produce colorless or white products that form intermediate steps, with no sulfides among the end products of the reactions. Although all the components of the stabilizing system of the invention are known as stabilizers or co-stabilizers, their synergistic effects with antimony derivatives have also been described, for example in NSR Pat. no. No. 2,704,487 and no. No. 2,454,986, U.S. Pat. No. 3,919,168 and no. No. 4,391,757, the entire system has not been described yet, and its effect in suppressing sulphide formation in white and transparent compositions has not been described.

Although the interaction of the individual components of the system and the mechanism of its shaking at higher temperatures is not known precisely, it has been shown in a number of tests that none of its components can be omitted or reduced below the described range because it loses its effect and develops a coloring sulphides.

The stabilizing system of the invention may be combined with other ingredients that enhance its thermal or light stabilizing effect, for example with metal soaps, benzophenone, triazole and amine derivatives, dialkyl tin mercaptides or carboxylates, but these do not participate in the suppression of sulfide formation.

Example 1

Plasticized polyvinyl chloride for injection, consisting of:

S-PVC (K-value 65) 54 d. di 2-ethylhexyl 38 d. chloroparaffins 2 d. micronized limestone 1.75 d. titanium white 0.9 d. azodicarbonamide 0.15 d. wax E 0.2 d. Sb-tris-isooctyl mercaptoacetate 0.55 d. epoxy resin / equivalent 0.5 / 0.5 d. ZnSOi.7 HžO 0.1 d. tris-nonylphenylphosphite 0.5 d. dilaurate 0.8 d. A-steareth 0.55 d.

Example 2

Plastisol for casting:

micro suspension PVC (K-75) 20 d. emulsion PVC (K-70) 20 d. suspension PVC (K-65) 10.5 d. di 2-ethylhexyl 40 d. micronized limestone 2.9 d. titanium white 3 d. partial fatty glyceride 1 d. Zn octoate 0.8 d. silicone oil 0.08 d. Sb-tris-isooctyl mercaptoacetate 0.6 d. epoxy resin / equivalent 0.5 / 0.4 d. ZnSCk. 7 HzO 0.12 d. tris fenyletylfenylfosfit 0.4 d. dilaurate 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.