Use of hydroxybenzotriazole derivatives and/or hydroxy indazole derivatives as flame retardants for plastics and flameproof plastic moulded bodies

1. A method of imparting flame retardancy to a plastic material comprising combining the plastic material with a flame retardant compound, wherein the plastic material is selected from the group consisting of thermoplastic, elastomeric, and duroplastic plastic materials; and

wherein the flame retardant compound is according to the general formulae I to IV

or a mixture of at least two compounds of the general formulae I to IV,

wherein, with each occurrence, respectively independently of each other,

R 1 is selected from the group consisting of hydrogen, alkyl radicals with 1 to 18 carbon atoms, partially or perfluorinated alkyl radicals with 1 to 18 carbon atoms, unsaturated organic radicals with up to 1 to 18 carbon atoms, two vicinal radicals R 1 also being able to be joined to form a ring, —NO 2 , —F, —Cl and —Br, and

R 2 is selected from the group consisting of mono-, bi- or trivalent inorganic or organic cations.

2. The method according to claim 1 , wherein the plastic material is selected from the group consisting of:

a) polymers made of olefins or diolefins, and copolymers in the form of statistical or block structures, terpolymers, and graft polymers,

b) a polymer selected from polystyrene, polymethylstyrene, polyvinylnaphthalene, styrene-butadiene (SB), styrene-butadiene-styrene (SBS), styrene-ethylene-butylene-styrene (SEBS), styrene-ethylene-propylene-styrene, styrene-isoprene, styrene-isoprene-styrene (SIS), styrene-butadiene-acrylonitrile (ABS), styrene-acrylonitrile-acrylate (ASA), styrene-ethylene, styrene-maleic anhydride polymers including corresponding graft copolymers, and graft copolymers made of methylmethacrylate,

c) halogen-comprising polymers,

d) polymers made of unsaturated esters,

e) polymers made of unsaturated alcohols and derivatives,

f) polyacetals,

g) polyphenylene oxides and blends with polystyrene or polyamides,

h) polymers of cyclic ethers,

i) polyurethanes and polyureas,

j) polyamides,

k) polyimides, polyamideimides, polyetherimides, polyesterimides, polyetherketones, polysulphones, polyethersulphones, polyarylsulphones, polyphenylene sulphide, polybenzimidazoles, and polyhydantoins,

l) polyesters made of aliphatic or aromatic dicarboxylic acids and diols or made of hydroxycarboxylic acids,

m) polycarbonates, polyester carbonates, and blends thereof,

n) cellulose derivatives,

o) non-thermoplastic or duroplastic plastic materials,

p) epoxy resins,

q) phenol resins, urea-formaldehyde resins, and melamine-formaldehyde resins,

r) unsaturated polyester resins made of unsaturated dicarboxylic acids and diols,

s) silicones,

t) polyurethanes which are reaction products from di- or polyfunctional isocyanates and polyols, and polyureas,

u) alkyd resins and allyl resins, and

v) mixtures, combinations or blends of two or more of the previously mentioned polymers.

3. The method according to claim 1 , wherein the compound according to the general formulae I to IV and/or the mixture of at least two compounds of formula I to IV is mixed with the plastic material, the total content of the compound according to the general formulae I to IV in the resulting mixture being 0.01 to 50% by weight.

4. The method according to claim 1 , wherein the mono-, di- or trivalent inorganic cations are selected from the group consisting of Li + , Na + , K + , ½ Mg 2+ , ½ Ca 2+ , ⅓ Al 3+ , ½ Zn 2+ and/or the organic cations are selected from the group consisting of nitrogen- and phosphorus-containing organic cations.

5. The method according to claim 1 , wherein, with each occurrence, R 1 is hydrogen and/or R 2 is a mono- or bivalent inorganic cation.

6. The method according to claim 1 , further comprising combining the plastic material and the flame retardant compound with at least one further flame retardant selected from the group consisting of phosphorus-containing, nitrogen-containing, inorganic, silicon-containing, boron-containing, sulphur-containing, halogen-containing, and radical-forming flame retardants, wherein the at least one further flame retardant is combined in an amount of up to 70 parts by weight relative to the totality of the at least one compound according to the general formulae I to IV and of the at least one plastic material.

7. The method according to claim 6 , wherein the at least one further flame retardant is selected from the group consisting of

a) inorganic flame retardants, layer silicates, organically- or unmodified double salts, POSS-(polyhedral oligomeric silsesquioxane) compounds, huntite, hydromagnesite, and halloysite,

b) nitrogen-containing flame retardants,

c) phosphorus-containing flame retardants,

d) halogen-containing flame retardants based on chlorine and bromine, optionally in combination with Sb 2 O 3 and/or Sb 2 O 5 ,

e) borates, optionally on carrier materials,

f) sulphur-containing flame-retardants,

g) anti-drip agents,

h) silicon-containing compounds,

i) radical-forming flame-retardants, and

j) carbon modifications.

8. The method according to claim 1 , comprising combining the at least one plastic material and the at least one flame retardant with at least one stabilizer selected from the group consisting of phenolic antioxidants, phosphites, phosphonites, aminic antioxidants, sulphur-containing antioxidants, hydroxylamines, and hindered amines, in an amount of 0.01 to 10% parts by weight, relative to the totality of the at least one compound according to the general formulae Ito IV and of the at least one plastic material.