DD151075A1 - SELF-LOADING PLASTIC BASED ON A STYROPOLYMER - Google Patents

Abstract

It is the object of finding such Löeschmittel which reduce the mechanical properties of the polymer in the smallest possible way and have no other adverse side effects. The extinguishing agent used is 0.5 to 35 parts by weight. per 100 parts by weight Styrene polymers, a brominated oligomer of alpha-methyl styrene with 40 to 70 wt .-% of bromine bound bromine mixed. The molecular weight of the oligomers is 1000 to 5000. As synergists, inorganic extinguishing agents such as antimony trioxide may be used in an amount of 3 to 9 parts by weight. be added per 100 parts of styrene polymers. The oligomers are suitable for flameproofing polystyrene, especially for impact compact masses.

Description

Applicant: VBB Chemische Werke Buna 4212 Schkopau

Authorized Representative: Dr. med. Harry slept in the Combine V33 chemical V / erke Buna, 4212 Schkopau

19 66 25 - * -

Title of the invention

Self-extinguishing plastic based on a styrene polymer field of application of the invention

The invention relates to self-extinguishing plastics based on a styrene polymer, in which the self-extinguishing effect is achieved by the presence of a brominated oligomeric aromatic hydrocarbon.

Characteristic of the known technical solutions

Poly-styrenic substances find a wide range of technical applications. For many purposes, however, it is desirable for the plastics to be self-extinguishing. This property is achieved by the presence of extinguishing agents based on halogenated organic compounds. In the case of styrene-based plastics, addition of halogenated diphenyl, diphenyl ether and the like is particularly advantageous.

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A significant group of substances which inhibits the combustibility of the polystyrene plastics comprises broccinated aromatic hydrocarbons such as 2etrabromobenzene, tetrabromotoluene (Brit., PS 1 158 168), etrabromoxylene (G3SR-PS 97 296), brominated alkylbenzenes (BKD-AS 2 130 296, FRG). AS 2 064 677, Japan PS 71.24132) or brominated hexamethylbenzene (Franz. PS 2 018 490).

Another large extinguishing agent group are the brominated polymers and oligomers, such as. 3. Oligomers of the alkylbenzenes (BRD-AS 2 358 855, Franz. PS 1 520 880), alkylbenzene copolymers with dienes (BRD-AS 1 258 081) and addition products of cyclopentadienes and vinylaromatic hydrocarbons (US Pat. No. 3,891,599, USA-PS 3,711,563). The disadvantage of all these substances is that they significantly reduce the mechanical properties of the polymer in an effective amount, especially the notched impact strength of the compacts.

Z iel the invention

The aim of the invention is to find such an extinguishing agent, the mechanical properties of the polymer, such as. As the notched impact strength, degrades in the smallest possible way and has no other adverse side effects.

Explanation of the essence of the invention

The invention has for its object to find a bromine-containing, oligomeric additive, which meets the requirements mentioned.

Surprisingly, it has been found that the addition of brominated oligomers of δ-methylstyrene containing 40 to 70% by weight of nucleus-bonded bromine having a molecular weight of 1000 to 5000 in an amount of 0.5 to 35 parts by weight per 100 parts by weight of polymers to styrene polymers self-extinguishing plastic on the base

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of polystyrene, which does not have the disadvantages mentioned such as reduced impact strength. This is unexpected to those skilled in the art because the known extinguishing agents of similar structure significantly reduce the impact strength of the styrenic polymers.

The effect of this extinguishing agent can be further increased synergistically, if the self-extinguishing plastic also contains inorganic extinguishing agents, especially antimony trioxide having a particle size of less than 5y & m in an amount of up to 9 parts by weight per 100 2eile Styrolpolyiaer.

The self-extinguishing plastic based on a styrene polymer may also contain other known extinguishing agents, such as e.g. Compounds of Alummniums and phosphorus additionally included. Other additives, such as foaming agents, dyes, plasticizers, fillers, etc., can also be added to the plastics.

The styrenic polymer may be either a homo- or a copolymer of styrene or its derivatives. Of the copolymers, it is particularly the copolymers with butadiene, isoprene or acrylonitrile.

The advantage of the self-extinguishing plastic based on a styrene polymer and a brominated oligomer of pC-methylstyrene according to the invention is that the addition of the extinguishing agent, the mechanical properties, especially the Kferbschlagzähigkeit, are less reduced than is the case with known.

The invention is illustrated by the following examples, the results obtained with parameters of a Decabromdiphenyläther and antimony trioxide containing as extinguishing PoIy

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styrene and with parameters of a polystyrene without extinguishing agent additive.

Execution examples ·

Example 1 (comparative example)

In a high-speed mixer, 100 parts by weight of impact polystyrene, 14 parts by weight of decabromodiphenyl ether and 4 parts by weight of antimony trioxide were mixed together. The mixture was plasticized in a twin-screw extruder and subsequently granulated. Specimens were prepared from the granules and the flammability according to ASTH D 635 as well as the impact resistance and the breaking strength were determined.

The following properties were found

Polystyrene without extinguishing agent added Polystyrene / decambromodiphenyl ether / antimony brioxide Burning behavior according to ASiM D 635 flammable incombustible Notched impact strength (kJ / m ² ) 85.9 54.2 Tear resistance (LIPa) 25.7 24.6

Example 2

The procedure of Example 1 was repeated, instead of Decabromdiphenyläther a brominated oligomer of ofi - methylstyrene having a molecular weight of 1480, a bromine content of 52% by weight and a melting point of 80 to 90 ⁰ O was added. Two samples were prepared with different extinguishing agent content. Sample No. 1 containing 18 parts by weight and Sample 2 containing 26 parts by weight of the brominated oligomer of α-methylstyrene. The following properties were found:

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Sample Hr * 1 Sample No. 2 even incombustible hurrying on 73.6 57.7 24.9 24.8

Burning behavior according to ASi ¹ MD

Notched impact strength; (kJ / m). Tear resistance (MPo)

Example 3

The procedure of Example 1 was repeated, instead of decabromodiphenyl ether, a brominated oligomer of 0 ( -Methylmethyris having a molecular weight of 1700, a Bromöehalt of 55% and a melting point of 130 - 1'35 ⁰ C was added Composition as prepared in Example 2. The following values were found:

Burning behavior according to ASTM D

Notched impact strength (kJ / m ² ) Tear strength (LIPA)

Sample No. 1 Sample No. 2 even incombustible extinguishing 61.5 55.0 25.5 25.4

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Claims (2)

invention claim 1. Self-extinguishing plastic based on a styrene polymer and extinguishing agent additives, characterized in that it per 100 parts by weight of Styrolpolyme.ren, 0.5 to 35 parts by weight of a brominated oligomer of o <J-methyl styrene with a content of 4-0 to 70 Weight * -% of nucleus-bound bromine and having a molecular weight of 1000 to 5000 contains. _v 2. Self-extinguishing plastic according to item 1, characterized in that it additionally contains synergistically acting extinguishing agent, preferably antimony trioxide of a particle size below 5, / tm and / or extinguishing agents such as compounds of aluminum and phosphorus. iPR 1Q77_ «.-Mi / · ·