DE1271979B - Flame retardant colored molding compounds - Google Patents

Description

Flame-resistant colored molding compositions It is known to use halogen-containing, in particular bromine-containing substances as flame retardants for thermoplastic polymers to use. In order to achieve an adequate flame retardant effect, it is necessary to to add relatively large amounts of halogen-containing substances to the polymers. However, this has an adverse effect on certain properties.

It is also known the flame retardant effect of bromine-containing compounds to be strengthened by additives, so that one can use much smaller amounts of bromine-containing Compounds can achieve an adequate flame retardant effect. This is how it is, for example possible, by adding organic peroxides, the flame-retardant effect of organic To improve bromine compounds. Organic peroxides, however, have the disadvantage that they are toxic and sometimes decompose easily in an explosive manner. With sensitive People who handle such peroxides can develop dermatoses. Farther expensive and cumbersome precautions must be taken when handling peroxides to avoid explosions. In addition, peroxides also disintegrate slowly at room temperature so that products stored for a long time are no longer flame-retardant are.

Furthermore, it was known to use chlorinated hydrocarbons together Antimony trioxide to be used as a flame retardant for thermoplastic polymers. The disadvantage here is that a relatively large amount of antimony trioxide is required, whereby the mechanical properties are adversely affected. This stuff can in certain polymerization processes, e.g. B. in bead polymerization, are not already added to the monomer, since it is not in the bead polymer homogeneously distributed.

Furthermore, plastic compounds for production are already flame-retardant Known molded bodies which, in addition to styrene polymers, contain organic chlorine compounds, small amounts of certain organometallic compounds of metals of the VI. until VII. Subgroup of the Periodic System, such as ferrocene, the corresponding cobalt or manganese compounds or iron, cobalt or molybdenum carbonyl. the organometallic compounds have a synergistic effect on the organic Chlorine compounds, so that significantly smaller amounts of chlorine compounds are required, to make styrene polymers flame-retardant.

A disadvantage here is that the plastic masses that Containing ferrocene or ferrocene-like complex compounds, undesirably discolored are. This discoloration also changes over time because of these compounds be oxidatively degraded under the influence of atmospheric oxygen.

This discoloration is particularly annoying when it comes to colored plastic masses as it gradually changes the original hue.

Subject of the invention are thermoplastic mold; containing masses a styrene polymer, an organic chlorine or bromine compound and optionally a propellant characterized in that it also contains 0.01 to 10 percent by weight contain one or more dyes in which heavy metals as a complex or are bound in salt form.

For the purposes of the invention, styrene polymers are polystyrene and copolymers from styrene and other monomeric polymerizable compounds, the at least Contains 50 percent by weight of styrene polymerized. As comonomers, for. B. in question a-methylstyrene, nuclear halogenated styrenes such as 2,4-dichlorostyrene, acrylonitrile, Methacrylonitrile, ester cc, ß-unsaturated carboxylic acids with alcohols, the 1 to Contains 8 carbon atoms, such as acrylic acid and methacrylic acid ester, fumaric acid ester of Alcohols with 1 to 8 carbon atoms, N-vinyl compounds such as N-vinyl carbazole, butadiene and small amounts of divinylbenzene.

Suitable organic chlorine compounds are those that have a high Have a melting point and whose chlorine content is between 40 and 75%, like low molecular weight Chlorine compounds, e.g. B. hexachlorocyclododecane, hexachlorocyclopentadiene, hexachlorendomethylenetetrahydrophthalic acid, Tetrachlorobutyrolactone, tetrachlorobutanediol diacetate. High molecular weight ones are particularly suitable chlorine-containing compounds which do not have the properties of styrene polymers or affect only slightly. Such compounds are e.g. B. post-chlorinated polyvinyl chloride with a chlorine content of about 58 to 63 percent by weight, chlorinated polyisobutylene with a chlorine content of about 40 to 50 percent by weight. Are particularly suitable also chlorinated paraffins with a, chlorine content. from 60 to 75 percent by weight, Their carbon chains - at least 18 to 40 C-A torne - contain. It's in everyone Case, it makes sense to use chlorine compounds with a high chlorine content in order to: their quantities to be able to keep the plastic mass as low as possible. The chlorine compounds are added to the plastic compounds in such amounts that they have a chlorine content of at least 2 percent by weight. In most cases it is not necessary that the masses contain more than 15 percent by weight of chlorine. Preferably included the 'masses 3 to 6 percent by weight of chlorine.

Suitable organic bromine compounds are above all those with a Bromine content of over -30 percent by weight, e.g. B. tetrabromobutane, dibromoethylbenzene, Dibromopropanol, or esters or acetates of dibromopropanol, e.g. B. Tris (dibromopropyl) phosphate, In addition, pentabromodiphenyl ether, organic bromine compounds are particularly suitable, which are not very volatile, which do not act as plasticizers or only to a small extent and have no unpleasant smell. Here in particular are the bromination products of Butadiene or isoprene oligomers or polymers, e.g. B. hexabromocyclododecane, octabromohexadecane, or brominated natural or synthetic rubber. The bromine compounds are used in such amounts that the plastic masses have a bromine content of at least 0.5 percent by weight. In most cases it is not necessary that the masses contain more than 5 percent by weight of bromine. Preferably. Contain the Masses 1 to 3 percent by weight bromine.

As dyes, the heavy metals are bound as a complex or in salt form included, come z. B. metal complex dyes or color lakes in question. Suitable Metal complex dyes are z. B. 1: 1 or 1: 2 complexes of azo or azomethine dyes, Complexes of complex-forming nitrosonaphthols or complexes of phthalocyanine. In particular, for example, the heavy metal complexes of azo dyes or soluble and insoluble halogenated and unhalogenated copper phthalocyanines into consideration. Heavy metals of main group IV and V come as heavy metals as well the I. to VIII. subgroup of the periodic system, z. B. Chromium, Cobalt, nickel, manganese or iron. Of the color lacquers, for. B. the complex heteropoly acid salts of azo and triphenylmethane dyes. as Heteropolyacids come e.g. B. in question: phosphotungstic acid, phosphomolybdenum or phosphomolybdenum tungstic acid.

The plastic compounds contain between 0.01 and 10, advantageously between 0.1 and 5 percent by weight, based on the mass, of one or more metal-containing Dyes.

Molding compositions which are colored for the production of flame-retardant foam-shaped materials are of particular importance Structures are suitable. In addition to a styrene polymer, they contain an organic chlorine or a bromine compound and an organic metal-containing dye. Propellant. Propellants are gaseous or liquid hydrocarbons under normal conditions or to understand halogenated hydrocarbons, which .. do not dissolve the plastic. Suitable are z. B. propane, butane, pentane, hexane or dichloromethane.

# Substances are also suitable which - at a certain temperature Split off gäsförinige stöee. Such substances. are z. B. azodiisobutyronitrile.

The propellants can be used in the foamable plastic quantities from 2 to 20 percent by weight, based on that contained in the plastic compounds Polymer, be included. From such foamable plastic masses Colored flame-retardant foam bodies are obtained by removing fine particles of these Masses in gas-permeable forms at temperatures above the softening point _ heated the polymers contained in the masses so that the particles expand and weld them to form bodies. Such foamable Kunststoffniassen can can also be processed into foam sheets with the help of extruders.

The plastic masses can also contain other common components be e.g. B. fillers such as lubricants, antistatic agents and plasticizers.

The metal-containing dyes can be used to produce the plastic compounds together with the organic halogen compound or individually one after the other with the styrene polymer and optionally also with other components - mixed will. They can be used, for example, on a roll, in an extruder or in a kneader insert into the plastic. In many cases you can use the monomers as usual be added before the polymerization. It is also possible, for. B. at the production of cast films, the metal-containing dye together with the halogen compound a solution of the plastic in which they remain after the solvent has been removed, to add.

Since many organic metal complex dyes dissolve in styrene, not on the other hand in water, it is in the special case of colored flame retardant and expandable granular masses containing a blowing agent, Mixtures of monomers, blowing agents, halogen compounds and organic metal complex dyes in aqueous suspension in colored flame retardant and expandable granular Convict masses.

The molding compositions can, for example, by injection molding or extrusion molding processed into flame-retardant moldings or profiles. In organic Dissolved in solvents, the plastic compounds are also suitable as flame-retardant Varnishes, e.g. B. for wood or metal coatings. Because of their relatively low salary the molding compositions according to the invention have softening points of organic halogen compounds, which differ only slightly from those of the polymers contained in them.

The molding compounds are also distinguished by the fact that they also follow Do not lose the property of flame retardancy over a longer storage period and do not discolour, so that the original shade is retained.

The flame retardancy of the molding compounds is tested in the following way: Unfoamed plastic compounds with the dimensions 0.1-3 # 12 cm are foamed with the dimension 3 # 3 - 12 cm in the non-luminous flame of a for 5 seconds Bunsen burner held and then removed from the flame with a smooth movement. The extinction time of the shaped body after removal from the flame is a measure of its flame resistance. An extinguishing time of 0 to 2 seconds can be described as very good, one such from 2 to 5 seconds as well. Extinguishing times of less than 10 seconds are sufficient. Molding compounds with insufficient or non-flame retardant properties will burn after removal from the flame completely.

The parts mentioned in the examples are parts by weight. The K values were based on the method of H. F i k e n t s c h e r, Cellulosechemie, 13 (1932), P. 60, determined.

The following dyes were used in the examples (C. L numbers are the numbers of the dyes from Color Index, Second Edition, 1956). A. Nickel complex of an azo dye C.I. No. 12775. B. Manganese complex of an azo dye C.I. No. 15865.

C. Iron complex of a nitrosonaphthol dye CI No. 10006. D. Copper complex of a phthalocyanine dye G. 1 . No.74260.

E. Copper complex of a phthalocyanine dye C.I. 74160.

F. Phosphotungstic molybdic acid-containing dye C.I. No. 45160.

G. Copper complex of a phthalocyanine dye. EXAMPLE 1 In a stirred autoclave, 4,000 parts of water containing 4 parts of polyvinylpyrrolidone with a K value of 90 dissolved, 1960 parts of styrene in a mixture with 40 parts of hexabromocyclodedecane, 200 parts of petroleum ether with a boiling point of 35 to 40 ° C., 8.8 parts of azodiisobutyronitrile and each one of the metal complex dyes given in Table 1 is heated to 80 ° C. for 30 hours. Foam bodies are produced from the plastic beads obtained in gas-permeable molds by means of steam and their flame resistance is tested by the method described above. Table 1 Dye parts K-value of the in the mass color of the out of the mass extinction time of the contained polymer produced foam body foam body A 0.6 52.7 pale yellow 10 seconds D 1.5 52.1 light green 10 seconds G 5 49.2 blue 5 seconds - - 48.2 white burns down EXAMPLE 2 20 parts of polystyrene (K value = 60), 3 parts of pentane and the compounds given in Table 2 are dissolved in 80 parts of methylene chloride each time and cast films are produced from the solution. The films that remain after the solvent has evaporated are foamed in boiling water and, after drying, tested for their flame resistance. Table 2 Dye parts halogen compound parts color of the extinguishing time Foam sheet of the foam sheet A 0.004 hexabromocyclododecane 0.4 pale yellow 5 seconds - - Hexabromocyclododecane 0.4 white burns off - - Hexabromocyclododecane 0.6 white 15 seconds E 0.2 hexabromocyclododecane 0.6 light blue 5 seconds B 0.2 hexabromocyclododecane 0.6 light red 5 seconds F 0.2 hexabromocyclododecane 0.6 pink 5 seconds C 0.2 chlorinated paraffin (Cl = 70%) 1.6 light green 5 seconds - Chlorinated paraffin (Cl = 70 "/,) 1.6 white burns off

Claims (1)

Claim: Thermoplastic molding compound containing a styrene polymer, an organic chlorine or bromine compound and optionally a propellant, characterized in that they also contain 0.01 to 10 percent by weight of one or contain several dyes in which heavy metals appear as a complex or in salt form are bound. References considered: U.S. Patent No. 2,986 547.