DE1258081B - Flame-retardant thermoplastic molding compounds - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Int. Cl .:

C08f

German class: 39 b -22/06

Number: 1258 081

File number: B 85283IV c / 39 b

Filing date: January 5, 1966

Open date: January 4, 1968

It is known that low-volatility, bromine-containing organic compounds are used as flame retardants can use for thermoplastics. Have special technical importance before especially brominated butadiene or isoprene polymers, which are particularly useful as flame retardants suitable for self-extinguishing moldings made of foam-like styrene polymers. It has, however has shown that these compounds do not yet have all of the properties required for flame retardancy to satisfy. It has also already been proposed to use bromine compounds in admixture with such To use compounds as flame retardants that increase the effect of the bromine compounds. Such synergistic compounds are z. B. certain organic peroxides or metal-containing Links. The use of synergistic compounds has other disadvantages. So z. B. discolorations occur in the thermoplastic. It also usually works in practical use Difficulties in incorporating mixtures of compounds into the plastic instead of individual components.

The subject of the invention are thermoplastic molding compositions comprising a styrene polymer and a bromine-containing one contain organic compound, characterized in that they contain bromination products of Compounds of the formula

IO

CH,

C —Ar —C -

CH,

CH,

- (en) _z

Flame-retardant thermoplastic molding compounds

Applicant:

Aniline & Soda Factory in Baden

Aktiengesellschaft, 6700 Ludwigshafen

Named as inventor:

Dr. Herbert Naarmann, 6700 Ludwigshafen;

Dr. Edmund Priebe, 6710 Frankenthal;

Dr. Ernst Günther Kastning, 6701 Assenheim;

Dr. Herbert Willersinn,

Dr. Heinz Weber, 6700 Ludwigshafen, Germany

an aromatic radical. Thus, Ar can advantageously be a radical that is different from benzene, toluene, diphenyl, Naphthalene or anthracene, (en) is a group that is formed by the addition of butadiene or isoprene on the remainder in square brackets. Such common connections can z. B. by metallations with lithium, sodium, potassium, rubidium and / or cesium of aliphatic substituted aromatics are obtained on the tertiary hydrogen atom of the aliphatic side group. Depending on the type of addition of the butadiene or isoprene, the group (s) can have the following structure to have:

contain, in which Ar is an aromatic radical, (s) a grouping which is formed by addition or polymerization of butadiene or isoprene, y = 1 to 20 and χ or ζ = 1 to 100.

The bromine-containing flame retardants to be used according to the invention have a better flame retardant effect as known flame retardants based on brominated butadiene polymers. It is therefore not necessary to combine the bromine compounds with synergistic compounds to use. The brominated polymers also have the advantage that they are a relatively have a high decomposition point, so that the molding compositions according to the invention are below the usual Do not discolour processing conditions.

In the bromination products of the compounds of the general formula given above, Ar is

a) (- CH ₂ - CH = CH - CH ₂ -)

b) (- CH ₂ -C-) where RH or CH ₃ denotes

CH

Il

CH ₂

c) (- CH ₂ - CH -)

C-R

CH ₂

Polymers which contain structures b) and c) are particularly suitable.

709 717/651

3 4

The number y is 1 to 20 inclusive, preferably does not dissolve merisat and its boiling point is below 2 to 10. The number χ or ζ is 1 to 100, the preferred softening point of the polymer is, for. B. wise 5 to 65. It goes without saying that χ and ζ are aliphatic or cycloaliphatic hydrocarbons

or can be different. substances such as propane, butane, pentane, hexane, heptane, cy-

In the bromination products of the compounds ₅ clohexane or halogenated hydrocarbons, such as methyl

of the general formula should expediently via chloride, dichlorodifluoromethane or 1,2,2-trifluoro-

50% of the double bonds be brominated. 1,1,2-trichloroethane. Also mixtures of propellants

The bromination products begin at 180 ^° C. and can be contained in the masses. It has to be decomposed before splitting off hydrogen bromide. partly, 3 to 10 percent by weight, based on the

Although to achieve a certain flame _I0 styrene polymer to use blowing agent, protective effect smaller amounts of bromine compounds according to the invention from such foamable molding compositions who are needed to be used than with the z. B. self-extinguishing foam body comparable bromine compounds, it is appropriate to keep fine particles of these compounds in gas that the molding compounds contain at least such amounts of the permeable molds at temperatures above bromine compounds that the bromine _{content 15 of} the softening point contained in the compounds 0.1 Weight percent is. In most cases, the polymers are heated so that the particles expand, and it is not necessary for the masses to degenerate and weld to form molded bodies. Such 5 weight percent bromine contain. Preferably foamable molding compositions can also be processed by extruders into foam sheets with the aid of the compositions containing 0.5 to 2 percent by weight. Bromine. Styrene polymers within the meaning of the invention ₂ o For the production of self-extinguishing foams, polystyrene and copolymers of styrene, shaped webs or films can, as usual, contain the at least 50 percent by weight of styrene polymerized individual components of the molding compositions merged together. Can be mixed with a blowing agent as a mixed polymerisation compound. The mixing nents come z. B. in question a-methylstyrene, acrylic is advantageous in a continuously operating nitrile, methacrylonitrile, ester of acrylic or meth 25 mixing device, for. B. in an extruder, vorgeacryläure and alcohols with 1 to 8 carbon atoms, took. One works at temperatures which are upper fumaric acid esters from alcohols with 1 to 8 carbon atoms, half the softening point of the plastics. Vinylpyridine, N-vinyl compounds, such as N-vinylcarb- The mixtures should be kept under a pressure azole, butadiene or small amounts, eg. B. 0.001, which is at least equal to the pressure of the propellant to 1.0, preferably 0.01 to 0.1 percent by weight, 30 means. This avoids the mian divinylbenzene. already during the mixing process or

The molding compounds for production self-extinguish- during heating to temperature ·; above

the moldings can also foam up so-called impact of their softening point

contain tough styrene polymers. For this impact pressure of the propellant, the pressure is to be understood

tough styrene polymers are counted z. B. Mi- 35 adjusts itself at the corresponding temperature,

If organic liquids are used as blowing agents

tuell together with other monomers in counter-turns or gaseous compounds below the

was of finely divided rubber-like polymer critical temperature, then the blowing

seeds are preserved. One can such polymers mean the vapor pressure of the blowing agent, the

also by mixing styrene acrylonitrile copolymer 40 itself over the mixture of the thermoplastic

seeds with butadiene or acrylic acid ester polymer plastic and the propellant forms,

making seeds. The mixtures are in a zone of lesser

Other customary pressures can also be expressed in the molding compositions. So the pressure should be in this zone

Components may be included, e.g. B. fillers, dye under the propellant pressure at the prevailing

substances, color pigments, lubricants, plasticizers, anti-45 temperature, so that the mixtures

Statics, anti-aging agents, stabilizers or foams. In most cases it is best to

those compounds that promote foam formation. most moderate, the mixtures in one under normal pressure

The molding compositions can be in finely divided form, for. B. to squeeze out standing zone. Sometimes it can happen Pearl form, in the form of cylindrical granules or in part, the pressure in the zone under normal form of chunks are present, how to keep them under pressure during grinding.

can be obtained from bulk polymers. The orga-

Particles advantageously have a diameter of niche bromine compounds with the styrene polymer

0.1 to 6 mm, preferably from around 0.4 to 3 mm. sat and possibly with further components

The molding compounds can be mixed, for example, by components. You can, for example

Injection molding or extrusion to self-extinguish- 55 on the roll, in the extruder or in a kneader

the moldings or profiles are processed. insert into the plastic. You can in many

Due to their relatively low content of organic cases, the mono-

The niche halogen compounds have been added to the invention. It is also possible, for. B. at

According to molding compounds softening points, which affect the production of cast films, the bromine compound

add 60 of those of the polymers contained in them to a solution of the plastic and that

differ slightly. To evaporate the solvent.

Molding compounds which are produced from the molding compounds by themselves are of particular importance Production of self-extinguishing foam-shaped extinguishing moldings are carried out in the following manner Structures are suitable. In addition to styrene polymer, they contain: To test the foamed materials are sowed and the organic bromine compound a propellant 65 molded body for 5 seconds in a luminous gas means. '' The flame is kept at a height of 40 mm and the propellants are either liquid or the flame is then removed with a gentle movement, gaseous organic compounds that make up the poly- The extinction time of the molded body after removal

from the flame is a measure of its flame resistance. Insufficient or not flame retardant Finished molding compounds burn off completely after being removed from the flame.

The parts mentioned in the examples are parts by weight and the percentages are percentages by weight.

d) Ar - biphenyl, y = ~ 5, χ or ζ =
en = isoprene, bromine content ~ 65%

-15, -60,

-45,

Tabel

Styrene polymer

Flame retardant medium

: Weight percent

Polystyrene

example

In each case 30 parts of a styrene polymer and certain amounts of an organic bromine compound are dissolved in 100 parts of methylene chloride. 3 parts of pentane are added to the solution. The solution is then poured onto a glass plate and the methylene chloride is allowed to evaporate at room temperature. The pentane remains homogeneously distributed in the mixture. The film obtained in this way is ^{foamed in water vapor at 100 °} C. and dried in vacuo at 35 ^° C. for a period of 12 hours. The foam films obtained are tested for their flame retardancy by the method given above. The results are given in the table.

Flame retardants used

a) 1,2-polybutadiene (brominated) MW = -5000, Bromine content ~ 70% (comparison test).

Flame retardants according to the invention:

b) Ar = phenylene, y = ~ 3, χ or ζ =
en = butadiene, bromine content ~ 70%;

c) Ar = phenylene, y = ~ 8, χ or ζ =
en = butadiene, bromine content ~ 70%:

15 copolymer from
Weight percent

Styrene

25 percent by weight
Acrylonitrile

a a

b b

c c

d d

away

Extinction time in seconds

1.0

1.25

1.0

1.25

1.0

1.25

1.0

1.25

1.0 1.0

11.0 9.0

2.9 1.8

3.1 2.1

3.6

2.4

12.0

3.7

Claims (1)

Claim: Thermoplastic molding compounds containing a styrene polymer and a bromine-containing organic compound contain, characterized in that they contain bromination products of Compounds of the formula (en) _x - CH, C — Ar — C - LCH ₃ CH ■ 3_Y> · (en) _z 35, where Ar is an aromatic radical, (s) a grouping which is formed by addition or polymerization of butadiene or isoprene, 3 · = 1 to 20 and χ or ζ = 1 to 100. 709 717/651 12.67 © Bundesdruckerei Berlin