SU606868A1 - Polymer composition - Google Patents

Description

The invention relates to stabilized compositions based on styrene copolymers with diene rubber. Such compositions may find use in the manufacture of articles with enhanced resistance to heat and light. Polymer compositions are known, including styrene copolymers with polybutadiene (impact polystyrenes) or styrene copolymers with acrylic acid nitrile and polybutadiene (ABS plastic), in which organic compounds, such as alkylphenols l, benzophenone 2, benztriene derivatives, are used as stabilizers. Tinuvina Pz. However, the known stabilizers from the class of alkylphenols are only thermal stabilizers, and compounds such as benzophenone a and demolitolol are only light stabilizers. A composition based on impact polystyrene (graft copolymer of styrene with diene rubber) and thermostabilizer are also known. A significant disadvantage of the above compositions is their insufficient thermal and light stability, and, moreover, the introduction of a di- (-4-phenylaminophenyl) carbonate 4 as a stabilizer, which gives the composition a dark (brown) color, resulting in the composition can only be recommended for the manufacture of products painted in dark color. The aim of the invention is to increase the thermal stability and preserve the natural color of the composition. The goal is achieved by the introduction of N, N-di (2.2,6,6-tetramethyl-4-piperidyl) -2, 4-toluenendicarbagshd as a heat stabilizing additive in the following ratio, wt.%: Graft copolymer of styrene with diene rubber 99,5-99,95 I, N-DI (2,2,6, 6-tetramethyl-4-piperidyl) -2, 4-trlyylenedicarbamid 0.05-0.5 The specified stabilizer has the structure, H) NH-CO -Uh nh h /. CHv CH, -CO-ELF KH J CHj CHj

The synthesis of this stabilizer, conditionally Named Lastar 2MB, is based on the reaction of the interaction of diazocnaates and 2,2,6,6-tetramethyl-4-aminopiperidine

Lastar 2MB is a white powder with m.p. 265-2b7 molecular weight 386.

Introduction of 2MB Lastar and coloration dye copolymer. To obtain an opaque composition, a filler — titanium dioxide in an amount of 0.5–1 wt.% Can be introduced into its composition.

As a graft copolymer of styrene with diene rubber, a copolymer of styrene with polybutadiene or x can be used: a styrene polymer with acrylonitrile and polybutadiene.

The introduction of a stabilizer into the composition under industrial conditions can be carried out by mixing in high-speed mixers. Under laboratory conditions, nacTStp 2MB can be introduced into the composition by mixing in a ball mill or it can be introduced into a solution of a copolymer.

Examples 1-5, A composition is prepared from a graft copolymer of styrene with polybutadiene or a styrene copolymer (or a mixture of styrene with methyl styrene with acrylonitrile and polybutadiene and a stabilizing additive by mixing the components in a ball mill at room temperature for 30 minutes.

The resulting compositions are granulated on a standard screw extruder and, using granulated material, the standard bars are made under pressure using standard bars 55x6x4 mm.

In order to determine the light stability, bars made from the proposed composition are exposed in a weather meter with a source of irradiation with carbon arc lamps, selected

samples after 50, 100, 200, 300 and 500 hours of exposure and determine the impact strength in accordance with GOST 46476i).

Thermal stability is determined by the nocyie heating of standard bars at 500, 100, 2000, and 3000 hours at the air thermostat by changing the toughness (Table 1).

Light and thermal stability is also determined by the oxidation rate of the composition under ultraviolet irradiation under a flPK-2 lamp or by heating at. To carry out such tests, thin films (50 µm) are made from a benzene solution of copolymer and a stabilizing additive. After warming up for 1,3,5,10 and 15 hours, the Pr 160®C or irradiation for 5, 10, 15 and 25 hours by the method of IR spectroscopy determines the number of groups (absorption bands of 1720 cuf) characterizing the oxidation rate (Table 2).

Examples 6-8 (control). The experiments were carried out as in Examples 1-5. The change in the oxidation rate of the composition in the presence of a stabilizer is given in Table 2.

These tables show that the composition with Lastar 2MB has a higher thermal and light stability than co-positions prepared with a known stabilizing additive (example 8) or industrial stabilizers (example 7),

Products from the proposed composition are highly stable under conditions of elevated temperatures and UV irradiation.

The invention can be used in the manufacture of Noluchenin compositions based on copolymer of styrene with polybutadiene (high impact polystyrenes and ABS plastics).

but

Well h

with

The change in the oxidation rate of the composition in the presence of.

stabilizer

A polymer composition comprising a graft copolymer of styrene with diene rubber and a stabilizing additive, characterized in that, in order to increase thermal stability and preserve the natural color of the composition, it contains as a stabilizing additive a M, M-di (2,2,6, 6- tetramethyl-4-piperidyl) -24-toluylene endcarbamide in the following ratio of components, wt.%:

Graft copolymer

styrene with diene

rubber 99,5-99,95

table 2

6, -tetramethyl-4-piperidyl) -2, 4-toluylenicarbamide 0.05-0.5 Sources of information taken into account in the examination:

1. The patent of France 1343872, cl. From 08 if 1963.

2. USSR author's certificate number 179467, cl. From 08 U 25/06, 1964.

3. US Patent I 3368997, cl. 260-45.8, 1968.

4. Author's certificate of the USSR 401699, cl. From 08 L 25/06, 1972.