DE2415449C3 - Flame-resistant polyolefin molding compounds - Google Patents

Description

Thermoplastic polymers, such as. B. Polyolefins have a number of properties that make them common to many Make uses appear particularly suitable. However, you have a serious one Disadvantage that limits their scope and that is their flammability

Halogenated organic compounds are mainly used to make plastics flame-retardant and antimony trioxide mixed into them. Usually, in order to achieve a sufficient effect, larger amounts of additives are applied, which in turn deteriorates the physical Properties such as strength, gloss, electrical insulation, etc., of these mixtures are conditioned.

Many of the previously known additives diffuse to the surface over time and sweat out, whereby the flame retardant effect is reduced.

In the Austrian patent specification 2 48 107 both chlorinated paraffins and halogenated cycloaliphatics and halogenated aromatics are mentioned as flame retardants. British Patent 9 10 545 describes the esters of halogenated alcohols with unsaturated polycarboxylic acids which can be subjected to a copolymerization with other polymerizable compounds and which give flame-retardant resins; Furthermore, in British patent 10 94 723 esters of halogenated alcohols with halogenated dicarboxylic acids are given as a flame-retardant additive, especially for polystyrene.
It has now been found that bis (23-dibromopropyl) fumarate is particularly suitable as a flame-retardant additive for polyolefins, in particular polypropylene, and shows a good effect even when relatively small amounts are added

ίο The subject of the invention are therefore flame retardant Polyolefin mixtures with a content of organic halogen compounds and antimony trioxide, which are characterized in that they contain 3 to 15% by weight as the organic halogen compound (based on the finished mixture) of bis- (2 ^ -dibromopropylj-fumarate and 1.0 to 5% by weight of antimony trioxide (based on the finished mixture), wherein these mixtures also contain conventional additives such as fillers, stabilizers, pigments and / or foaming agents may contain.

The flame-retardant mixtures according to the invention offer particular advantages if the polyolefin Polypropylene is. In this case, mixtures are particularly preferred which contain only 4-7% by weight of bis (2,3-dibromopropyl) fumarate contain. The antimony trioxide content is expediently 1.5 to 3.0% by weight.

Bis- (2,3-dibromopropyl) fumarate is so thermally stable that it can be incorporated into the polyolefin even at temperatures above 200 ^° C., as are particularly necessary for processing polypropylene, and does not suffer any decomposition

Furthermore, this compound has the advantageous property of not migrating from the mixtures, see above that the flame retardancy of the moldings produced therefrom is permanently guaranteed.

This addition has proven to be particularly advantageous for Polypropylene has proven to be very effective at 4% in the mixture together with 1.5% Sb2C> 3 shows.

Bis (2,3-dibromopropyl) fumarate can be produced in a simple manner by bromination of diallyl fumarate.
The following examples are intended to show the advantages of these flame-retardant polyolefin mixtures in more detail, without restricting the invention thereto.

Example 1 to 3

With a ram kneader at 19O ⁰ C working temperature door moldings were produced the following compositions and tested with 32 specimens per test according to ASTM D 635th

example 1 Example 2 Example 3 Polypropylene
Dibromopropyl fumarate
Antimony trioxide 91.5% by weight
6.5 wt%
2.0 wt% 94.5% by weight
4.0% by weight
1.5 wt% 96.0% by weight
3.0% by weight
1.0 wt% 32 test specimens, of which
going out immediately
not going out
afterburning
average
Burning time (sec) 28
0
4th
0.9 5
0
27
1.0 0
0
32
2.6

With an addition of only 3.0% of the halogen compound, all test rods extinguish in a short time Time, at 63% addition, 28 of 32 go out immediately.

Example 5

example Polystyrene 4th 84% Copolymers with
5 approx. 15% polyethylene Dibromopropyl himarate 92% 12% Dibromopropyl himarate Sb ₂ O ₃ 6% 4% Sb ₂ O ₃ Going out immediately 2% 0 Going out immediately Afterburning 0 32 Afterburning Average 32 io average Afterburn time (sec) 13th Afterburn time (sec) 3.4

92% 6% 2% 0

32

1.9

Claims (4)

Patent claims: 1. Flame-retardant molding compounds, consisting of A) polyolefins, B) organic halogen compounds, C) Antimony triox ^ d, as well as optionally usual additives, characterized that they are 3 to 15% by weight, based on the finished mixture, as the organic halogen compound of bis (23-dibromopropyl) fumarate and 1.0-5% by weight of antimony trioxide, based on the finished product Mixture, included. 2. Flame-retardant polyolefin molding compound according to claim 1, characterized in that the polyolefin is polypropylene 3. Flame-resistant polyolefin molding compositions according to Claims 1 and 2, characterized in that that the mixture with polypropylene as polyolefin 4 to 7 wt .-% bis (2 ^ -dibromopropyl) fumarate contains 4. Flame-resistant polyols molding compositions according to claim 3, characterized in that the Antimony trioxide content is 1.5 to 3% by weight