WO2007063031A2 - Stabilized polymerizable mixtures - Google Patents

Abstract

Disclosed is a mixture containing (A) at least one aromatic heterocycle of general formula (I), wherein W, X, and Y can independently represent hydrogen, NR1R2, O-R3, P-R24, P-R4R6, SR5, C1-C20 alkylcarbonyl, C1-C20 alkoxycarbonyl, C2-C20 alkenyl, C2-C20 alkenylcarbonyl, C2-C20 alkinyl, C2-C20 alkinylcarbonyl, C3-C15 cycloalkyl, C5-C15 cycloalkylcarbonyl, aryl, arylcarbonyl, a heterocycle, aryl, a halogen atom, or C1-C20 alkyl, several or all hydrogen atoms in the C1-C20 alkyl group being optionally substituted with fluoride atoms or one or several of the hydrogen atoms being optionally replaced by SR5, and R1 and R2 have the meaning indicated below while R3 to R6 can also represent hydrogen, C1-C20 alkyl, C1-C20 alkylcarbonyl, C1-C20 alkoxycarbonyl, C2-C20 alkenyl, C2-C20 alkenylcarbonyl, C2-C20 alkinyl, C2-C20 alkinylcarbonyl, C3-C15 cycloalkyl, C5-C15 cycloalkylcarbonyl, aryl, arylcarbonyl, a heterocycle, or a halogen atom, Z can represent hydrogen, C1-C20 alkyl, C3-C15 cycloalkyl, aryl, or a heterocycle, and R1 and R2 can independently represent hydrogen, NR4R5, O-R3, P-R24, P-R4R6, SR5, C1-C20 alkyl, C1-C20 alkylcarbonyl, C1-C20 alkoxycarbonyl, C2-C20 alkenyl, C2-C20 alkenylcarbonyl, C2-C20 alkinyl, C2-C20 alkinylcarbonyl, C3-C15 cycloalkyl, C5-C15 cycloalkylcarbonyl, aryl, arylcarbonyl, a heterocycle, or a halogen atom while R3 to R6 can also represent hydrogen, C1-C20 alkyl, C1-C20 alkylcarbonyl, C1-C20 alkoxycarbonyl, C2-C20 alkenyl, C2-C20 alkenylcarbonyl, C2-C20 alkinyl, C2-C20 alkinylcarbonyl, C3-C15 cycloalkyl, C5-C15 cycloalkylcarbonyl, aryl, arylcarbonyl, a heterocycle, or a halogen atom, and (B) at least one polymerizable compound.

Description

 Stabilized polymerizable mixtures

description

The present invention describes novel mixtures of polymerizable compounds and stabilizers which are protected against polymerization. It also relates to polymers made from these blends.

For the purposes of the present invention, polymerizable compounds are understood as meaning compounds which have one or more ethylenically unsaturated groups.

Chemical compounds which have one or more ethylenically unsaturated groups have a pronounced tendency to radical polymerization. Such compounds are used as monomers for the controlled production of polymers, eg. B. by radical polymerization. At the same time, however, the pronounced tendency for free-radical polymerization is disadvantageous in that it occurs both during storage and during chemical and / or physical processing, for. Example by distillation or rectification, the ethylenically unsaturated compounds, in particular under the action of energy, for. As heat and / or light, can come to unwanted, spontaneous radical polymerization. Such uncontrolled polymerizations can be used for the gradual formation of polymer coatings z. B. lead to heated surfaces or even run explosively.

It is therefore common to add ethylenically unsaturated compounds or mixtures containing such compounds, both during storage and during chemical and / or physical processing substances that prevent or slow a spontaneous polymerization. They are generally referred to as inhibitors or retarders and summarized under the generic term "stabilizers".

A large number of stabilizers are known for polymerizable compounds, in particular for acrylic acid and methacrylic acid, hereinafter called (meth) acrylic acid, and their esters, hereinafter called (meth) acrylic esters.

From EP-A-1 1 10999 pyrazolones are described, which are used in combination with other stabilizers for the stabilization of polymers.

The non-prepublished patent application DE-102005023607 describes aromatic 6-membered heterocycles which are used for stabilizing polymerizable compounds and polymers. The above-described stabilizers are able to reliably protect polymerizable compounds from unwanted polymerization. A disadvantage of them, however, is that polymers prepared from polymerizable compounds to which these stabilizers have been added have a clearly discernible color. This probably arises from the fact that the stabilizer is destroyed in the polymerization and the degradation products formed have a strong intrinsic color. When these stabilizers are used, the choice is then made to tolerate the inherent color of the corresponding polymers or to remove the stabilizers from them immediately prior to the desired polymerization of the polymerizable compounds.

The object of the present invention was therefore to provide polymerizable compounds protected against undesired polymerization in which the polymer produced from them by desired polymerization has a significantly lower intrinsic coloration than when using known stabilizers, without the prior removal of the stabilizer being necessary.

Accordingly, a mixture was found which contains:

(A) at least one aromatic heterocycle of the general formula

worin

wherein

W, X and Y are independent

Hydrogen, NR ¹ R ² , OR ³ , PR ₂ ⁴ , PR ⁴ R ⁶ , SR ⁵ , d-CaO-alkylcarbonyl, C 1 -C ₂₀ -alkoxycarbonyl, C ₂ -C ₂₀ -alkenyl, C ₂ - C ₂₀ alkenylcarbonyl, C ₂ -C ₂₀ kinyl -alkyl, C ₂ -C ₂₀ -Alkinylcar-carbonyl, C3-Ci5-cycloalkyl, Cs-cis-cycloalkylcarbonyl, aryl, arylcarbonyl, heterocycle, aryl, a halogen atom, or C -C ₂₀ alkyl, wherein in the Ci-C ₂₀ -Alkyl group, several or all hydrogen atoms may be replaced by fluorine atoms or one or more of the hydrogen atoms may be replaced by SR ⁵ may be, and wherein R ¹ and R ^{2 are} the below have the meaning given, and R ³ to R ⁶ is also hydrogen, Ci-C ₂₀ alkyl, C ₂₀ alkylcarbonyl, C ₂₀ alkoxycarbonyl, C ₂ -C ₂₀ alkenyl, C ₂ -C ₂₀ alkenylcarbonyl , C ₂ -C ₂₀ -alkynyl, C ₂ -C ₂₀ -alkynylcarbonyl,

C3-Ci5-cycloalkyl, Cs-Cis-cycloalkylcarbonyl, aryl, arylcarbonyl, a heterocycle or a halogen atom, Z can be hydrogen, C 1 -C 20 -alkyl, C 3 -C 15 -cycloalkyl, aryl or a heterocycle, and

R ¹ and R ² may be independently hydrogen, NR ⁴ R ⁵ , OR ³ , P-R ^{2 4} , P-R ⁴ R ⁶ , SR ⁵ ,

Ci-C2o-alkyl, _{Ci-C2o-alkylcarbonyl,} Ci-C2o-alkoxycarbonyl, _{C2-C2o-alkenyl,} C ₂ -C ₂₀ alkenylcarbonyl, _C2-C2o alkynyl, C ₂ -C ₂₀ - Al kinyl carbonyl, C3-Ci5-cycloalkyl, Cs-Cis-cycloalkylcarbonyl, aryl, arylcarbonyl, a heterocycle or a halogen atom, and wherein R ³ to R ^{6 is} also hydrogen, Ci-C ₂ o-alkyl, Ci-C ₂₀ alkyl carbonyl, _{Ci-C2o-alkoxycarbonyl,} C ₂ -C ₂ -alkenyl, C ₂ -C ₂ o-Alkenylcar-carbonyl, C ₂ -C ₂ O-AI kinyl, C ₂ -C ₂ o Alkynylcarbonyl, C3-Ci5-cycloalkyl, Cs-Cis-cycloalkylcarbonyl, aryl, arylcarbonyl, a heterocycle or a halogen atom, and

(B) at least one polymerizable compound.

In formula (I), preference is given to W, X and Y being hydrogen, NR ¹ R ² , OR ³ , C ₁ -C ₂₀ -alkyl, C ₂ -C ₂ o-alkenyl or a halogen atom, with the proviso that in the case of NR ¹ R ² R ¹ and R ^{2 are the} same and are hydrogen or C ₁ -C 20 -alkyl, and in the case of OR ³ R ^{3 is} hydrogen or C ₁ -C 20 -alkyl.

In formula (I), Z is preferably hydrogen, OR ³ , C 1 -C ₂₀ -alkyl, C 1 -C ₂₀ -alkylcarbonyl or C ₁ -C 20 -alkoxycarbonyl, with the proviso that in the case of OR ³ R ^{3 is} hydrogen or C ₁ -C 4 -alkyl -C ₂₀ alkyl.

In formula (I), R ¹ and R ² are preferably identical and are hydrogen, C ₁ -C 20 -alkyl, C ₁ -C 20 -alkylcarbonyl or C ₁ -C 20 -alkoxycarbonyl, particularly preferably hydrogen, C ₁ -C 10 -alkyl C 1 -C 10 -alkylcarbonyl or C 1 -C 10 -alkoxycarbonyl, very particularly preferably hydrogen, C 1 -C 6 -alkyl, C 1 -C 6 -alkylcarbonyl or C 1 -C 6 -alkoxycarbonyl.

The radicals R ³ , R ⁴ , R ⁵ and R ⁶ in formula (I) are preferably hydrogen or C 1 -C ₂₀ -alkyl, particularly preferably hydrogen or C 1 -C ₁₀ -alkyl and very particularly preferably hydrogen or C 1 -C ⁶ -alkyl.

In detail, the collective terms given for the various radicals R have the following meaning:

C ₁ -C 20 -alkyl: straight-chain or branched hydrocarbon radicals having up to 20 carbon atoms, preferably C 1 -C 10 -alkyl, such as methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, 1, 1-dimethylethyl, pentyl, 2-methylbutyl, 1, 1-dimethylpropyl, 1, 2-dimethylpropyl, 2,2-dimethylpropyl, 1-ethylpropyl, hexyl, 2-methylpentyl, 3-methyl- pentyl, 1, 1-dimethylbutyl, 1, 2-dimethylbutyl, 1, 3-dimethylbutyl, 2,2-dimethylbutyl, 2,3-dimethylbutyl, 3,3-dimethylbutyl, 2-ethylbutyl, 1, 1, 2-trimethylpropyl, 1, 2,2-trimethylpropyl, 1-ethyl-1-methylpropyl, 1-ethyl-2-methylpropyl, heptyl, octyl, 2-ethylhexyl, 2,4,4-trimethylpentyl, 1, 1, 3, 3-tetramethylbutyl, nonyl and decyl and their isomers.

Ci-Cao-alkylcarbonyl: a straight-chain or branched alkyl group having 1 to 20 carbon atoms (as mentioned above), which is bonded via a carbonyl group (-CO-), preferably Ci-do-alkylcarbonyl such as formyl, acetyl, n- or iso-propionyl, n-, iso-, sec- or tert-butanoyl, n-iso-, sec- or tert-pentanoyl, n- or iso-nonanoyl, n-dodecanoyl.

C 2 -C 20 -alkenyl: unsaturated, straight-chain or branched hydrocarbon radicals having 2 to 20 carbon atoms and a double bond in any position, preferably C 2 -C 10 -alkenyl, such as ethenyl, 1-propenyl, 2-propenyl, 1-methylethenyl, 1 Butenyl, 2-butenyl, 3-butenyl, 1-methyl-1-propenyl, 2-methyl-1-propenyl, 1-methyl-2-propenyl, 2-methyl-2-propenyl, 1-pentenyl, 2-pentenyl, 3-pentenyl, 4-pentenyl, 1-methyl-1-butenyl, 2-methyl-1-butenyl, 3-methyl-1-butenyl, 1-methyl-2-butenyl, 2-methyl-2- butyl, 3-methyl-2-butenyl, 1-methyl-3-butenyl, 2-methyl-3-butenyl, 3-methyl-3-butenyl, 1, 1-dimethyl-2-propenyl, 1, 2- Dimethyl 1-propenyl, 1, 2-dimethyl-2-propenyl, 1-ethyl-1-propenyl, 1-ethyl-2-propenyl, 1-hexenyl, 2-hexenyl, 3-hexenyl, 4-hexenyl, 5- Hexenyl, 1-methyl-1-pentenyl, 2-methyl-1-pentenyl, 3-methyl-1-pentenyl, 4-methyl-1-pentenyl, 1-methyl-2-pentenyl, 2-methyl-2-pentenyl, 3-methyl-2-pentenyl, 4-methyl-2-pentenyl, 1-methyl-3-pentenyl, 2-methyl-3-pentenyl, 3-methyl-3-pen tenyl, 4-methyl-3-pentenyl, 1-methyl-4-pentenyl, 2-methyl-4-pentenyl, 3-methyl-4-pentenyl, 4-methyl-4-pentenyl, 1, 1-dimethyl-2- butenyl, 1, 1-dimethyl-3-butenyl, 1, 2-dimethyl-1-butenyl, 1, 2-dimethyl-2-butenyl, 1, 2-dimethyl-3-butenyl, 1, 3-dimethyl-1 butenyl, 1, 3-dimethyl-2-butenyl, 1, 3-dimethyl-3-butenyl, 2,2-dimethyl-3-butenyl, 2,3-dimethyl-1-butenyl, 2,3-dimethyl-2- butenyl, 2,3-dimethyl-3-butenyl, 3,3-dimethyl-1-butenyl, 3,3-dimethyl-2-butenyl, 1-ethyl-1-butenyl, 1-ethyl-2-butenyl, 1 - Ethyl 3-butenyl, 2-ethyl-1-butenyl, 2-ethyl-2-butenyl, 2-ethyl-3-butenyl, 1, 1, 2-trimethyl-2-propenyl, 1-ethyl-1 - methyl-2-propenyl, 1-ethyl-2-methyl-1-propenyl and 1-ethyl-2-methyl-2-propenyl, as well as the isomers of heptenyl, octenyl, nonenyl and decenyl.

C 2 -C 20 -alkenylcarbonyl: unsaturated, straight-chain or branched hydrocarbon radicals having 2 to 20 carbon atoms and a double bond in any position (as mentioned above) which are bonded via a carbonyl group (-CO-), preferably C 2 -C 10 -alkylcarbonyl, such as for example, ethenyl, propenoyl, butenoyl, pentenoyl, nonenoyl and their isomers.

C 2 -C 20 -alkynyl: straight-chain or branched hydrocarbon groups having 2 to 20 carbon atoms and a triple bond in any position, preferred C ₂ -C 10 -alkynyl, such as ethynyl, 1-propynyl, 2-propynyl, 1-butynyl, 2-butynyl, 3-butynyl, 1-methyl-2-propynyl, 1-pentynyl, 2-pentynyl, 3-pentynyl, 4-pentynyl, 1-methyl-2-butynyl, 1-methyl-3-butynyl, 2-methyl-3-butynyl, 3-methyl-1-butynyl, 1, 1-dimethyl-2-propynyl, 1 - Ethyl 2-propynyl, 1-hexynyl, 2-hexynyl, 3-hexynyl, 4-hexynyl, 5-hexynyl, 1-methyl-2-pentynyl, 1-methyl-3-pentynyl, 1-methyl-4 pentynyl, 2-methyl-3-pentynyl, 2-methyl-4-pentynyl, 3-methyl-1-pentynyl, 3-methyl-4-pentynyl, 4-methyl-1-pentynyl, 4-methyl-2- pentynyl, 1, 1-dimethyl-2-butynyl, 1, 1-dimethyl-3-butynyl, 1, 2-dimethyl-3-butynyl, 2,2-dimethyl-3-butynyl, 3, 3-dimethyl-1 - butinyl, 1-ethyl-2-butynyl, 1-ethyl-3-butynyl, 2-ethyl-3-butynyl and 1-ethyl-1-methyl-2-propynyl and the isomers of heptynyl, octynyl, nonynyl, decynyl ,

C 2 -C 20 -alkynylcarbonyl-unsaturated, straight-chain or branched hydrocarbon radicals having 2 to 20 carbon atoms and a triple bond in any position (as mentioned above) which are attached via a carbonyl group (-CO-), preferably C 2 -C 10 -alkynylcarbonyl such as propinoyl, butinoyl, pentinoyl, noninoyl, decinoyl and their isomers.

C3-C15-cycloalkyl: monocyclic, saturated hydrocarbon groups having 3 to 15 carbon ring members, preferably Ca-Cs-cycloalkyl such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl and cyclooctyl and a saturated or unsaturated cyclic system such as. B. norbornyl or norbenyl.

C 3 -C 15 -cycloalkylcarbonyl: monocyclic, saturated hydrocarbon groups having 3 to 15 carbon ring members (as mentioned above) which are via a carbonyl group (-CO-), preferably Ca-C 5 -cycloalkylcarbonyl.

Aryl: a mono- to trinuclear aromatic ring system containing 6 to 14 carbon ring members, e.g. As phenyl, naphthyl and anthracenyl, preferably a mononuclear to dinuclear, more preferably a mononuclear aromatic ring system.

Arylcarbonyl: preferably a mono- to trinuclear aromatic ring system (as mentioned above), which is bonded via a carbonyl group (-CO-), such as. B. benzoyl, preferably a mono- to binuclear, more preferably a mononuclear aromatic ring system.

Heterocycles: five- to twelve-membered, preferably five- to nine-membered, particularly preferably five- to six-membered oxygen, nitrogen and / or sulfur atoms optionally containing several rings ring system such as furyl, thiophenyl, pyrryl, pyridyl, indolyl, benzoxazolyl, dioxolyl, Dioxyl, benzimidazolyl, benzothiazolyl, dimethylpyridyl, methylquinolyl, dimethylpyrryl, methoxyfuryl, dimethoxypyridyl, difluoropyridyl, methylthiophenyl, isopropylthiophenyl or tert-butylthiophenyl. The substituents listed in detail may each be interrupted at any position by one or more heteroatoms as described above, the number of these heteroatoms being not more than 10, preferably not more than 8, very particularly preferably not more than 5 and in particular not more than 3 is, and / or in any position, but not more than five times, preferably not more than four times and more preferably not more than three times, by alkyl, alkyloxy, alkyloxycarbonyl, aryl, aryloxy, aryloxycarbonyl, hydroxycarbonyl, aminocarbonyl, hetero Rocyclen, heteroatoms or halogen atoms may be substituted, which may also be substituted by a maximum of twice, preferably a maximum of once with the said groups.

The classes of alkyl, aryl and heterocycles mentioned in this group have the abovementioned meaning.

Heteroatoms are oxygen, nitrogen, sulfur or phosphorus.

Alkyloxy denotes a straight-chain or branched alkyl group having 1 to 20 carbon atoms (as mentioned above) which are bonded via an oxygen atom (-O-), preferably C 1 -C 10 -alkyloxy, for example methoxy, ethoxy, propoxy.

Alkoxycarbonyl is an alkoxy group having 1 to 20 carbon atoms (as mentioned above), which is bonded via a carbonyl group (-CO-), preferably Ci-Cio-alkyloxycarbonyl.

Aryloxy is a mono- to trinuclear aromatic ring system (as mentioned above) which is bonded via an oxygen atom (-O-), preferably a mono- to binuclear, particularly preferably a mononuclear aromatic ring system.

Aryloxycarbonyl is a mono- to trinuclear aryloxy group (as mentioned above) which is bonded via a carbonyl group (-CO-), preferably a mono- to binuclear, particularly preferably a mononuclear aryloxycarbonyl.

Halogen atoms are fluorine, chlorine, bromine and iodine.

The preparation of the aromatic heterocycles of the general formula (I) is generally known and described, for example, in the following references:

As described, for example, in MH Elnagdi, GEH Elgemeie, FA Abd-Elaal, Heterocycles 1985, 23, 3121, pyrazoles can be prepared by reaction of aryl or alkyl hydrazines with beta-bifunctional educts. The beta-bifunctional educts include beta-diketones, beta-keto esters and beta-diketronitriles. The reaction of hydrazines with acetylene derivatives also provides pyrazoles according to: Ed. AR Katrizki, Advances in Heterocyclic Chemistry 1976, 19, 301, Academic Press, New York.

Addition of a zinc compound prepared in situ from trichlorotrifluoroethane to benzaldehydes gives alcohols from which 1-aryl-3,3,3-trifluoropropynes are accessible (G. Meazza, G. Zanardi, P. Piccardi, J. Heterocyc Chem , 30, 365). Depending on the reaction conditions, cycloaddition with diazomethane leads to differently substituted pyrazoles (Y. Kobayashi, T. Yamashita, K. Takahashi, H. Kuroda, I. Kumaidaki, Chem. Pharm. Bull. 1984, 32, 4402).

Substituted phenylhydrazines can be reacted with methyl methacrylates via a base-catalyzed ring-closing reaction to give the corresponding pyrazolidone derivatives. The subsequent oxidation leads to the desired pyrazole derivatives (J. Chem. Soc. Perkin Trans 2, 1982, 1599).

JP 85-29357 describes the reaction of methylhydrazine with methoxyacrylic acid methyl ester to give 5-hydroxypyrazole.

Another synthetic route is to acylate 3-pyrazolidone on a nitrogen atom in the first step and to alkylate the amide nitrogen in the second step. Finally, the pyrazole is oxidized (H. Dorn, Angew. Chem. 1966, 78, 676).

When the following text refers to the or an aromatic heterocycle of the formula (I), this also includes the possibility of a mixture of aromatic heterocycles of the formula (I). The same applies mutatis mutandis to the term other stabilizer, costabilizer and polymerizable compound.

In a preferred embodiment of the process according to the invention, the aromatic heterocycle of the formula (I) is advantageously used together with another stabilizer or costabilizer. These are z. DE-A 102 49 507 and DE-A 102 58 329, DE-A 198 56 565 and EP-A 765 856. As a result, existing deficiencies of the known stabilizers, for example, the color structure during the action or the processing of the polymerizable compound and the insufficient effect of the stabilizers during the workup of the polymerizable compound, compensated.

The mixtures according to the invention preferably contain at least one costabilizer. In general, the costabilizer is selected from the group of oxygen-containing gases, phenolic compounds, quinones and hydroquinones, N-oxyl compounds, aromatic amines, phenylenediamines, imines, sulfonamides, oximes, Hydroxylamines, urea derivatives, phosphorus-containing compounds, sulfur-containing compounds, complexing agents based on tetraazannulen and metal salts, and optionally mixtures thereof.

Oxygen-containing gases may, for example, be those gases which have an oxygen content of between 0.1 and 100% by volume, preferably of 0.5 to 50% by volume and more preferably of 1 to 25% by volume. For example, these may be nitrogen monoxide, nitrogen dioxide, oxygen or dinitrogen trioxide or air. These may be mixed individually, in any mixtures with one another or with another gas, for example nitrogen, noble gases, water vapor, carbon monoxide, carbon dioxide or lower alkanes, preferably air or air-nitrogen mixtures.

Phenolic compounds are for. B: phenol, alkylphenols, for example o-, m- or p-cresol (methylphenol), 2-tert-butyl-4-methylphenol, 6-tert-butyl-2,4-dimethylphenol, 2,6-diol tert-butyl-4-methylphenol, 2-tert-butylphenol, 4-tert-butylphenol, 2,4-di-tert-butylphenol, 2-methyl-4-tert-butylphenol, 4-tert-butyl 2,6-dimethylphenol, or 2,2'-methylenebis (6-tert-butyl-4-methylphenol), 4,4'-oxydiphenyl, 3,4-methylenedioxy-diphenol (sesamol), 3, 4-dimethylphenol, catechol (1, 2-dihydroxybenzene), 2- (1'-methylcyclohex-1'-yl) -4,6-dimethylphenol, 2- or 4- (1'-phenyleth-1'-yl) phenol , 2-tert-butyl-6-methylphenol, 2,4,6-tris-tert-butylphenol, 2,6-di-tert-butylphenol, naphthylphenol [CAS-No. 1 1066-49-2], octylphenol [CAS-No. 140-66-9], 2,6-dimethylphenol, bisphenol A, bisphenol B, bisphenol C, bisphenol F, bisphenol S, 3,3 ', 5,5'-tetrabromobisphenol A, 2,6-di-tert .-butyl-p-cresol, Koresin® from BASF Aktiengesellschaft, methyl 3,5-di-tert-butyl-4-hydroxybenzoate, 4-tert-butylcatechol, 2-hydroxybenzyl alcohol, 2-methoxy-4-methylphenol, 2,3,6-trimethylphenol, 2,4,5-trimethylphenol, 2,4,6-trimethylphenol, 2-isopropylphenol, 4-isopropylphenol, 6-isopropyl-m-cresol, n-octadecyl-beta- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate, 1,1,3-tris- (2-methyl-4-hydroxy-5-tert-butylphenyl) butane, 1, 3.5- Trimethyl-2,4,6-tris (3,5-di-tert-butyl-4-hydroxybenzyl) benzene, 1, 3,5, -tris (3,5-di-tert-butyl-4 -hydroxybenzyl) isocyanurate, 1,3,5-tris (3,5-di-tert-butyl-4-hydroxyphenyl) propionyloxyethyl isocyanurate, 1,3,5-tris- (2,6-dimethyl 3-hydroxy-4-tert-butylbenzyl) isocyanurate or pentaerythritol tetrakis [beta- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], 2,6-di-tert. butyl-4-dimethylaminomethyl phenol, 6-sec-butyl-2,4-dinitrophenol, Irganox ^® 565, 1010, 1076, 1 141, 1 192, 1222 and 1425 from Ciba Specialty Chemicals, 3- (3 ', 5'-di-tert. -butyl-4'-hydroxyphenyl) octadecyl propionate, hexadecyl 3- (3 ', 5'-di-tert-butyl-4'-hydroxyphenyl) propionate, 3- (3', 5'-di-tert-butyl) 4'-hydroxyphenyl) propionic acid octyl ester, 3-thia-1, 5-pentanediol bis - [(3 ', 5'-di-tert-butyl-4'-hydroxyphenyl) propionate], 4,8-di- oxa-1,1,1-undecanediol bis - [(3 ', 5'-di-tert-butyl-4'-hydroxyphenyl) propionate], 4,8-dioxa-1,1,1-undecanediol bis [ (3'-tert-butyl-4'-hydroxy-5'-methylphenyl) propionate], 1, 9-nonanediol-bis - [(3 ', 5'-di-tert-butyl-4'- hydroxyphenyl) propionate], 1, 7-heptanediamine bis [3- (3 ', 5'-di-tert-butyl-4'-hydroxyphenyl) propionic acid amide], 1, 1-methanediamine bis [3- (3' , 5'-di-tert-butyl-4'-hydroxyphenyl) propionic acid amide], 3- (3 ', 5'-di-tert-butyl-4'-hydroxyphenyl) - propionic acid hydrazide, 3- (3 ', 5'-dimethyl-4'-hydroxyphenyl) propionic acid hydrazide, bis (3-tert-butyl-5-ethyl-2-hydroxyphen-1-yl) methane, bis (3,5 -di-tert-butyl-4-hydroxyphen-1-yl) methane, bis [3- (1 '-methylcyclohex-1'-yl) -5-methyl-2-hydroxyphen-1-yl] methane, bis - (3-tert-butyl-2-hydroxy-5-methylphen-1-yl) methane, 1, 1-bis (5-tert-butyl-4-hydroxy-2-methylphen-1-yl) ethane , Bis (5-tert-butyl-4-hydroxy-2-methylphen-1-yl) sulfide, bis (3-tert-butyl-2-hydroxy-5-methylphen-1-yl) sulfide, 1 , 1-Bis- (3,4-dimethyl-2-hydroxyphen-1-yl) -2-methylpropane, 1, 1-bis (5-tert-butyl-3-methyl-2-hydroxyphen-1-yl ) butane, 1,3,5-tris [1 '- (3 ", 5" -di-tert-butyl-4 "-hydroxyphen-1" -yl) meth-1'-yl] -2,4 , 6-trimethylbenzene, 1, 1, 4-tris (5'-tert-butyl-4'-hydroxy-2'-methylphen-1'-yl) butane and tert-butyl catechol, and aminophenols , such as B. p-aminophenol, nitrosophenols, such as. For example, p-nitrosophenol, p-nitroso-o-cresol, alkoxyphenols, such as 2-methoxyphenol (guaiacol, pyrocatechol monomethyl ether), 2-ethoxyphenol, 2-isopropoxyphenol, 4-methoxyphenol (hydroquinone monomethyl ether), mono- or di-tert-butyl 4-methoxyphenol, 3,5-di-tert-butyl-4-hydroxyanisole, 3-hydroxy-4-methoxybenzyl alcohol, 2,5-dimethoxy-4-hydroxybenzyl alcohol (syringa alcohol), 4-hydroxy-3-methoxybenzene aldehyde (vanillin), 4-hydroxy-3-ethoxybenzaldehyde (ethylvanillin), 3-hydroxy-4-methoxybenzaldehyde (isovanillin), 1- (4-hydroxy-3-methoxyphenyl) ethanone (acetovanillon), eugenol, dihydroeugenol, Isoeugenol, tocopherols, such as. B. alpha, beta, gamma, delta and epsilon tocopherol, tocol, beta-tocopherol hydroquinone, and 2,3-di-hydro-2,2-dimethyl-7-hydroxybenzofuran (2,2-dimethyl-7 hydroxycumaran).

Suitable quinones and hydroquinones are, for example, hydroquinone or hydroquinone monomethyl ether (4-methoxyphenol), methylhydroquinone, 2,5-di-tert-butylhydroquinone, 2-methyl-p-hydroquinone, 2,3-dimethylhydroquinone, trimethylhydroquinone,

4-methylcatechol, tert-butylhydroquinone, 3-methylcatechol, benzoquinone, 2-methyl-p-hydroquinone, 2,3-dimethylhydroquinone, trimethylhydroquinone, tert-butylhydroquinone, 4-ethoxyphenol, 4-butoxyphenol, hydroquinone monobenzyl ether, p-phenoxyphenol, 2-methylhydroquinone, tetramethyl-p-benzoquinone, diethyl-1,4-cyclohexanedione-2,5-dicarboxylate, phenyl-p-benzoquinone, 2,5-dimethyl-3-benzyl-p-benzoquinone, 2- isopropyl 5-methyl-p-benzoquinone (thymoquinone), 2,6-diisopropyl p-benzoquinone, 2,5-dimethyl-3-hydroxy-p-benzoquinone, 2,5-dihydroxy-p-benzoquinone, Embelin , Tetrahydroxy-p-benzoquinone, 2,5-dimethoxy-1,4-benzoquinone, 2-amino-5-methyl-p-benzoquinone, 2,5-bis-phenylamino-1,4-benzoquinone, 5,8-dihydroxy-1 , 4-naphthoquinone, 2-anilino-1,4-naphthoquinone, anthraquinone, N, N-dimethylindoaniline, N, N-diphenyl-p-benzoquinone diimine, 1,4-benzoquinone dioxime, coerulignone, 3,3'- Di-tert-butyl-5,5'-dimethyldiphenoquinone, p-rosolic acid (aurin), 2,6-di-tert-butyl-4-benzylidene-benzoquinone, 2,5-di tert-amyl hydroquinone.

As N-oxyls (nitroxyl or N-oxyl radicals, compounds which have at least one> NO group) are z. B. suitable 4-hydroxy-2,2,6,6-tetramethyl-piperidine N-oxyl, 4-oxo-2,2,6,6-tetramethylpiperidine-N-oxyl, 4-methoxy-2,2,6,6-tetramethylpiperidine-N-oxyl, 4-acetoxy-2, 2,6,6-tetramethyl-piperidine-N-oxyl, 2,2,6,6-tetramethyl-piperidine-N-oxyl, Uvinul ^® 4040P from BASF Aktiengesellschaft, 4,4 ', 4 "-tris (2, 2,6,6-tetramethylpiperidine-N-oxyl) phosphite, 3-oxo-2,2,5,5-tetramethylpyrrolidine-N-oxyl, 1 -Oxyl-2,2,6,6- tetramethyl-4-methoxypiperidine, 1 -Oxyl-2,2,6,6-tetramethyl-4-trimethylsilyloxypiperidine, 1 -Oxyl-2,2,6,6-tetramethylpiperidin-4-yl-2-ethylhexanoate, 1 - Oxyl 2,2,6,6-tetramethylpiperidin-4-yl sebacate, 1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl-stearate, 1 -Oxyl-2,2,6,6- tetramethylpiperidin-4-yl benzoate, 1 -Oxyl 2,2,6,6-tetramethylpiperidin-4-yl- (4-tert-butyl) benzoate, bis (1-oxyl-2,2,6, 6-tetramethylpiperidin-4-yl) succinate, bis (1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl) adipate, 1, 10-decanedioic acid bis (1-oxyl-2, 2,6,6-tetramethylpiperidin-4-yl), bis (1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl) n-butyl malonate, bis (1-oxyl-2,2, 6,6-t etramethylpiperidin-4-yl) phthalate, bis (1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl) isophthalate, bis (1-oxyl-2,2,6,6-tetramethylpiperidine-4- yl) terephthalate, bis (1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl) hexahydroterephthalate, N, N'-bis (1-oxyl-2,2,6,6-tetramethylpiperidine-4 -yl) adipinamide, N- (1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl) caprolactam, N- (1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl ) dodecyl succinimide, 2,4,6-tris [N-butyl-N- (1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl] triazine, N, N'-bis (1 -oxyl-2,2,6,6-tetramethylpiperidin-4-yl) -N, N'-bis-formyl-1, 6-diaminohexane, 4,4'-ethylene-bis (1-oxyl-2,2 , 6,6-tetramethylpiperazin-3-one).

As aromatic amines, or phenylenediamines, for example, suitable N ₁ N-di- phenylamine, N-nitroso-diphenylamine, nitrosodiethylaniline, p-phenylenediamine, N, N'-di-alkyl-p-phenylenediamine, wherein the alkyl groups may be the same or different and each independently of one another can consist of 1 to 4 carbon atoms and can be straight-chain or branched, for example N, N'-di-isobutyl-p-phenylenediamine, N, N'-di-isopropyl-p-phenylenediamine, Irganox ^® 5057 from Ciba Spezialitätenchemie, N-phenyl-p-phenylenediamine, N, N'-diphenyl-p-phenylenediamine, N-isopropyl-N-phenyl-p-phenylenediamine, N, N'-di-sec-butyl- p-phenylenediamine (Kerobit® BPD from BASF Aktiengesellschaft), N-phenyl-N'-isopropyl-p-phenylenediamine (Vulkanox ^® 4010 from Bayer AG), N- (1, 3-dimethylbutyl) -N'-phenyl-p- phenylenediamine, N-phenyl-2-naphthylamine, iminodibenzyl, N, N'-diphenylbenzidine, N-phenyltetraaniline, acridone, 3-hydroxydiphenylamine, 4-hydroxydiphenylamine.

Imines are z. Methyl ethylimine, (2-hydroxyphenyl) benzoquinoneimine, (2-hydroxyphenyl) benzophenone imine, N, N-dimethylindoaniline, thionin (7-amino-3-imino-3H-phenothiazine), methylene violet (7-dimethylamino-3-methyl) phenothiazinon).

Suitable sulfonamides as stabilizer are, for example, N-methyl-4-toluenesulfonamide, N-tert-butyl-4-toluenesulfonamide, N-tert-butyl-N-oxyl-4-toluenesulfonamide, N, N'-bis (4 -sulfanilamide) piperidine, 3 - {[5- (4-aminobenzoyl) -2,4-dimethylbenzenesulfonyl] ethylamino} -4-methylbenzenesulfonic acid, as described in DE-A 102 58 329. Oximes can be, for example, aldoximes, ketoximes or amidoximes, as described, for example, in DE-A 101 39 767, preferably diethylketoxime, acetoneoxime, methylethylketoxime, cyclohexanone oxime, benzaldehyde oxime, benzil dioxime, dimethylglyoxime, 2-pyridinaldoxime, salicylaldoxime, phenyl-2-pyridylketoxime, 1, 4-benzoquinone-dioxime, 2,3-butanedione dioxime, 2,3-butanedione monooxime, 9-fluorenone oxime, 4-tert-butylcyclohexanone oxime, N-ethoxy-acetimidic acid ethyl ester, 2,4-dimethyl-3-pentanone oxime, cyclododecanone oxime, 4 Heptanonoxim and di-2-Furanylethandiondioxim or other aliphatic or aromatic oximes or their reaction products with alkyl transfer agents such. For example, alkyl halides, triflates, sulfonates, tosylates, carbonates, sulfates, phosphates or the like.

Hydroxylamines are z. N, N-diethylhydroxylamine and those disclosed in international application WO 03/099757.

Suitable urea derivatives are, for example, urea or thiourea.

Phosphorus compounds are z. B. triphenylphosphine, triphenyl phosphite, hypophosphorous acid, Trinonylphsophit, triethyl phosphite or Diphenylisopro- pylphosphin.

Examples of suitable sulfur-containing compounds are diphenyl sulfide, phenothiazine and sulfur-containing natural substances such as cysteine.

Complexing agents based on tetraazannulenes (TAA) are e.g. Thiebenzotetraza [14] annulenes and porphyrins as described in Chem. Soc. Rev. 1998, 27, 105-1 15.

Metal salts are z. As copper, manganese, cerium, nickel, chromium, carbonate, chloride, - dithiocarbamate, sulfate, salicylate or acetate, stearate, ethylhexanoate.

Preferred costabilizers are oxygen-containing gases, phenothiazine, o-, m- or p-cresol (methylphenol), 2-tert-butyl-4-methylphenol, 2,6-di-tert-butyl-4-methylphenol, 2 tert-butylphenol, 4-tert-butylphenol, 2,4-di-tert-butylphenol, catechol (1, 2-di-hydroxybenzene), 2,6-di-tert-butylphenol, 4-tert. Butyl-2,6-dimethylphenol, octylphenol [140-66-9], nonylphenol [11066-49-2], 2,6-dimethylphenol, 2,6-di-tert-butyl-p-cresol, Bisphenol A, tert-butyl catechol, hydroquinone, hydroquinone monomethyl ether or methylhydroquinone, 2,2,6,6-tetramethylpiperidine-N-oxyl, 4-hydroxy-2,2,6,6-tetramethyl-piperidine-N- oxyl, 4-oxo-2,2,6,6-tetramethylpiperidine-N-oxyl and manganese acetate, cerium (III) carbonate, cerium (III) acetate or cerium (III) ethylhexanoate, cerium ( III) stearate and mixtures thereof in different compositions. Particularly preferred are air, air-nitrogen mixtures, phenothiazine, o-, m- or p-cresol (methylphenol), 2,6-di-tert-butyl-4-methylphenol, 4-tert-butylphenol, 4- tert-butyl-2,6-dimethylphenol, octylphenol [140-66-9], nonylphenol [11066-49-2], 2,6-dimethylphenol, 2,6-di-tert-butyl-p-cresol , tert-butyl catechol, hydroquinone, hydroquinone monomethyl ether or methyl hydroquinone, 2,2,6,6-tetramethylpiperidine-N-oxyl, 4-hydroxy-2,2,6,6-tetramethyl-piperidine-N-oxyl, 4-Oxo-2,2,6,6-tetramethylpiperidine-N-oxyl and cerium (III) acetate or cerium (III) ethylhexanoate and mixtures of at least two of said components.

Particularly preferred are air, air-nitrogen mixtures, phenothiazine, hydroquinone and hydroquinone monomethyl ether and 2,2,6,6-tetramethyl-piperidine-N-oxyl, 4-hydroxy-2,2,6,6-tetramethyl-piperidine-N -oxyl, 4-oxo-2,2,6,6-tetramethylpiperidine-N-oxyl, N, N'-di-sec-butyl-p-phenylenediamine, cerium (III) acetate or cerium (III) ethylhexanoate and mixtures thereof.

The aromatic heterocycle of the general formula (I) or its mixture with another stabilizer or costabilizer is also referred to in the following text as a stabilizer.

If the stabilizer is a mixture, it contains as components i) the aromatic heterocycle of the general formula (I) and ii) another stabilizer or costabilizer in the following weight ratios (i): (ii): from 1: 100 to 100: 1, preferably 1:50 to 50: 1, more preferably 1:10 to 10: 1 and especially 1: 5 to 5: 1.

Preference is given to mixtures of at least the aromatic heterocycle of the general formula (I) and one of the following components:

Phenothiazine - hydroquinone monomethyl ether

4-hydroxy-2,2,6,6-tetramethyl-piperidine-N-oxyl

4-oxo-2,2,6,6-tetramethyl-piperidine-N-oxyl

2,2,6,6-tetramethyl-piperidine-N-oxyl

Phenothiazine / hydroquinone monomethyl ether - phenothiazine / 4-hydroxy-2,2,6,6-tetramethyl-piperidine-N-oxyl

Hydroquinone monomethyl ether / 4-hydroxy-2,2,6,6-tetramethyl-piperidine-N-oxyl at least one of said cerium salts, each in the presence or absence of an oxygen-containing gas, preferably in the presence.

The polymerizable compounds contained in the mixtures according to the invention is preferably selected from the group consisting of mono-, di- or triethylenisch unsaturated C3-Cs-carboxylic acids, Ci-C2o-esters, -amides, -nitriles and Anhydrides of these mono-, di- or triethylenisch unsaturated C3-Cs-carboxylic acids, vinyl esters of carboxylic acids containing up to 20 carbon atoms, vinyl ethers of alcohols containing 1 to 10 carbon atoms, vinyl aromatics and heteroaromatics having up to 20 carbon atoms , Vinyl lactams having 3 to 10 C atoms in the ring, open-chain N-vinyl amide compounds and N-vinylamine compounds, vinyl halides, aliphatic optionally halogenated hydrocarbons having 2 to 8 C atoms and 1 or 2 double bonds, vinylidenes or mixtures of these monomers.

Preferred mono-, di- or triethylenisch unsaturated C3-C6-carboxylic acids are z. B. (meth) acrylic acid, dimethylacrylic acid, ethacrylic acid, citraconic acid, methylenemalonic acid, crotonic acid, fumaric acid, mesaconic acid, itaconic acid, maleic acid and their Ci-C2o-alkyl esters, amides, nitriles, aldehydes and -Anhydride such. Methyl (meth) acrylate, ethyl (meth) acrylate, (meth) acrylic acid n-butyl ester, (meth) acrylic acid n-propyl ester, (meth) acrylic acid iso-propyl ester, (meth) acrylic acid 2-ethyl hexyl ester, (meth) acrylic acid aryl ester, maleic acid monomethyl ester, maleic acid dimethyl ester, maleic acid monoethyl ester, diethyl maleate, alkylene glycol (meth) acrylates, (meth) acrylamide, N-dimethyl (meth) acrylamide, N-tert-butyl (meth) acrylamide , (Meth) acrylonitrile, (meth) acrolein, (meth) acrylic anhydride, itaconic acid anhydride, maleic anhydride and its half esters. Cationic monomers of this group are, for example, dialkylaminoalkyl (meth) acrylates and dialkylaminoalkyl (meth) acrylamides, such as dimethylaminomethyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate and the salts of the last-mentioned monomers with carboxylic acids or mineral acids, and qauternated products.

Other monomers of this group are z. As well as hydroxyl-containing monomers, in particular Ci-Cio-hydroxyalkyl (meth) acrylates such as hydroxy ethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, hydroxyisobutyl (meth) acrylate.

Further monomers of this group are phenyloxyethylglycol mono- (meth) acrylate, glycidyl (meth) acrylate, trimethylolpropane triacrylate, ureidomethyl methacrylate, amino (meth) acrylates such as 2-aminoethyl (meth) acrylate.

Vinyl esters of carboxylic acids having 1 to 20 carbon atoms are, for. As vinyl laurate, vinyl stearate, vinyl propionate, vinyl versatate and vinyl acetate.

As vinyl ethers of 1 to 10 carbon atoms containing alcohols are z. For example, methyl vinyl ether, ethyl vinyl ether, butyl vinyl ether, 4-hydroxybutyl vinyl ether, vinyl isobutyl ether or dodecyl vinyl ether.

Examples of vinylaromatic and heteroaromatic compounds are

Vinyl toluene, α- and p-methylstyrene, α-butylstyrene, 4-n-butylstyrene, 4-n-decylstyrene, styrene, Divinylbenzene, 2-vinylpyridine, N-vinylimidazole, N-vinylpiperidone, N-vinyl-2-methylimidazole and N-vinyl-4-methylimidazole into consideration.

Vinyllactams having 3 to 10 carbon atoms in the ring are, for example, N-vinylcaprolactam, N-vinylpyrrolidone, laurolactam, oxygenated purines such as xanthine or its derivatives such as 3-methylxanthine, hypoxanthine, guanine, theophylline, caffeine, adenine or theobromine.

Furthermore, open-chain N-vinylamide compounds and N-vinylamine compounds such as N-vinylformamide, N-vinyl-N-methylformamide, N-vinylacetamide, N-vinyl-N-methylacetamide, N-vinyl-N-ethylacetamide, N-vinylpropionamide, N-vinyl Vinyl-N-methylpropionamide and N-vinylbutyramide and N-vinyl-N-dimethylamine, N-vinyl-N-methylethylamine, N-vinyl-N-diethylamine are stabilized by the novel process.

The vinyl halides are chloro, fluoro or bromo substituted ethylenically unsaturated compounds such as vinyl chloride, vinyl fluoride and vinylidene chloride.

Aliphatic optionally halogenated hydrocarbons having 2 to 8 C atoms and 1 or 2 olefinic double bonds are, for example, ethylene, propene, 1-butene, 2-butene, isobutene, butadiene, isoprene and chloroprene.

Vinylidene, for example, is called vinylidene cyanide.

Other polymerizable compounds are N-vinylcaprolactam, vinylphosphoric acids, vinylacetic acid, allylacetic acid, N-vinylcarbazole, hydroxymethylvinylketone, N, N-divinylethyleneurea, vinylene carbonate, tetrafluoroethylene, hexafluoropropene, nitroethylene, allylacetic acid, .alpha.-chloroacrylic ester, .alpha.-cyanoacrylic ester, methylene malonate, α-Cyansorbinsäureester, cyclopentadiene, cyclopentene, cyclohexene and cyclododecene.

In a preferred embodiment of the process according to the invention, the aromatic heterocycles are used for stabilizing mono-, di- or triethylenically unsaturated C 3 -C 8 -carboxylic acids, and their C 1 -C 20 -alkyl esters or N-vinylcaprolactam, N-vinylformamide, N-vinylimidazole, N-vinylformamide. Vinylpyrrolidone, vinylphosphoric, N-vinylcarbazole, N, N-divinylethyleneurea, trimethylolpropane, Ureidomethylmeth-acrylate, styrene, butadiene or isoprene used.

Preferred unsaturated C 3 -C 8 -carboxylic acids are, for example, acrylic acid and methacrylic acid and also their C 1 -C 8 -alkyl esters, such as, for example, For example, methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate. In general, the erfindungsgmäßen mixtures 0.1 to 1000 ppm of the aromatic heterocycle 'of the formula (I), based on the polymerizable compound, preferably 1 to 900 ppm, more preferably 10 to 800 ppm, most preferably 50 to 700 ppm and in particular 100 to 500 ppm.

In general, the erfindungemäße mixture comprising (A) the aromatic heterocycle 'of the general formula (I) and (B) the polymerizable compound prepared by reacting the aromatic heterocycle of the general formula (I), optionally together with the other stabilizers and or costabilizer mixed with the polymerizable compound.

The manner of adding the aromatic heterocycle of the general formula (I) and the other stabilizer or costabilizers to be used is not limited. The added aromatic heterocycle of the general formula (I) can be added individually or as a mixture with other stabilizers and / or with the aforementioned costabilizers, in liquid or in dissolved form in a suitable solvent, this solvent itself may be a stabilizer such , B. in DE-A 102 00 583 described.

The concentration of the solutions used is limited only by the solubility of the stabilizer in the solvent, for example, it may be 0.1 to 50 wt .-%, preferably 0.2 to 25 wt .-%, particularly preferably 0.3 to 10 wt .-% and most preferably 0.5 to 5 wt .-%.

Of course, if the melting point is below 120 ° C., preferably below 100 ° C., particularly preferably below 80 ° C. and in particular below 60 ° C., the stabilizer can also be used as a melt.

In a further preferred form, the aromatic heterocycle of general formula (I) is melted with a phenol having a melting point below 120 ° C., preferably below 100 ° C., more preferably below 80 ° C. and in particular below 60 ° C., as costabilizer used. The phenol is particularly preferably selected from p-aminophenol, p-nitrosophenol, 2-tert-butylphenol, 4-tert-butylphenol, 2,4-di-tert-butylphenol, 2-methyl-4-tert-butylphenol , 4-tert-butyl-2,6-dimezylphenol, hydroquinone and hydroquinone monomethyl ether.

As described above, 0.1 to 1000 ppm of the aromatic heterocycle of the general formula (I) is used relative to the polymerizable compound. If a mixture of at least one aromatic heterocycle of the general formula (I) with another stabilizer or costabilizers is used, then from 0.1 to 5000 ppm, preferably from 1 to 4000 ppm, particularly preferably from 5 to 2500 ppm, particularly preferably 10 to 1000 ppm and in particular 50 to 750 ppm, based on the polymerizable compound.

If a mixture containing more than one single compound from the group consisting of the compounds consisting of the aromatic heterocycle of the general formula (I), the other stabilizer and costabilizers used, these compounds can be fed both independently at different or equal metering points and independently be solved each other in different solvents.

The mixture according to the invention containing (A) the aromatic heterocycle of the general formula (I) and (B) the polymerizable compound is advantageously prepared directly in the preparation of the polymerizable compound. In this case, the stabilizer is preferably used in those places where the polymerizable compound, for example by high purity, high residence time and / or high temperature, is exposed to a risk of polymerization.

These may be, for example, absorption units, desorption units, rectification units, for example distillation apparatus or rectification columns, evaporators, for example natural or forced circulation evaporators, condensers or vacuum units.

For example, the stabilizers can be metered at the top of a rectification unit, z. B. in the head of the rectification unit, removal fixtures or on the separating internals such. As soils, packs, breakwaters or beds, sprayed or sprayed or metered together with the return, in a condenser, z. B. sprayed, so that the condenser head and / or the cooling surfaces are wetted, or in a vacuum unit, as described in EP-A 1 057 804 or as a barrier liquid in a liquid ring pump, as described in DE-A 101 43 565.

The mixture according to the invention containing (A) the aromatic heterocycle of the general formula (I) and (B) the polymerizable compound can be further prepared by reacting the stabilizer in the preparation of polymerizable compounds or the compounds used to prepare the polymer added polymerizable compounds used educts.

The erfindungemäß to be used aromatic heterocycles of the general formula (I) can be further used both as a storage and as a transport stabilizer, ie for stabilizing the pure polymerizable compounds. The mixture according to the invention containing (A) the aromatic heterocycle of the general formula (I) and (B) the polymerizable compound is effectively protected against oxidation or polymerization on contact with oxygen-containing gas, in particular gas mixtures containing oxygen and nitrogen, in particular air or air. nitrogen mixtures

The mixture (A) of the invention of the aromatic heterocycle of the general formula (I) and (B) of the polymerizable compound is particularly effective when stored in a vessel, e.g. a storage tank or conventional transport container containing a continuous liquid phase and a continuous gas phase, wherein the continuous liquid phase consists of the erfindungemäßen mixture containing (A) the aromatic heterocycle of the general formula (I) and (B) the polymerizable compound and the continuous Gas phase consists of an oxygen-containing gas.

In a preferred embodiment, the stabilizer is used in a process as described in DE-A 100 64 642. For this purpose, in a process for working up (meth) acrylic acid in the presence of the stabilizer, a mixture of substances originating from the workup, essentially containing (meth) acrylic acid, stabilizer-containing mixture is fed into a distillation apparatus and a low-boiler stream containing stabilizer obtained therefrom recycled the workup.

Such aromatic heterocycles according to the invention are particularly suitable for such a process whose vapor pressures at 141 ° C. (boiling point of acrylic acid) at normal pressure are at least 15 hPa, preferably between 20 and 800 hPa, more preferably between 25 and 500 hPa, very particularly preferably between 25 and 250 hPa and especially between 25 and 160 hPa, and mixtures thereof.

In a further preferred embodiment, the aromatic heterocycles according to the invention are used in a process for working up N-vinyl monomers such as the stated vinyl esters, vinyl ethers, vinylaromatics and heteroaromatics and the open-chain V-vinylamide compounds and N-vinylamine compounds.

Ppm and percentages used in this specification refer, unless otherwise indicated, to percentages by weight and ppm. Experimental part

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100 g (0.55 mol) of 2-chloro-5-trifluoromethylpyridine were dissolved in 800 ml of ethanol. 275 g (5.5 mol) of hydrazine hydrate were dissolved in 400 ml of ethanol and rapidly added dropwise at room temperature within 15 min. The solution was added for 8 h

wurde in 1 L tert-Butanol gelöst und 46.3 g (0.473 mol) Pro- piolsäureethylester innerhalb von 15 min zugetropft. Die Reaktionslösung wurde eingeengt, mit Wasser versetzt und mit Dichlormethan extrahiert. Die Wasserphase wurde mit Essigsäure auf pH 7 eingestellt und der resultierende Niederschlag abgesaugt, mit Wasser gewaschen und getrocknet: 57.2 g (0.25 mol, 58%).13 5O ⁰ C stirred. The solvent was distilled off, the solid was filtered off with suction, washed with water and dried: 76.3 g (0.43 mol, 78%). The hydrazine thus obtained

was dissolved in 1 L tert-butanol and 46.3 g (0.473 mol) of propiolic acid were added dropwise within 15 min. The reaction solution was concentrated, combined with water and extracted with dichloromethane. The water phase was adjusted to pH 7 with acetic acid and the resulting precipitate was filtered off with suction, washed with water and dried: 57.2 g (0.25 mol, 58%).

20 g (0.114 mol) of 3-trifluoromethylphenylhydrazine were dissolved in 210 ml of tert-butanol. 25.5 g (0.228 mol) of potassium tert-butoxide were added in portions. 10.5 g (0.125 mol) of methyl propiolate (dissolved in 30 ml of tert-butanol) were

und Essigsäureethylester wurde die Wasserphase auf pH 2 angesäuert, mit Essigsäureethylester extrahiert, mit Natriumsulfat getrocknet und das Lösungsmittel abdestilliert. Man erhielt 6.8 g (0.030 mol, 26%) Feststoff. 14 slowly added dropwise and refluxed for 1 h. The solvent was distilled off and the remaining residue was taken up in 300 ml of water. After extraction with dichloromethane

and ethyl acetate, the water phase was acidified to pH 2, extracted with ethyl acetate, dried with sodium sulfate and the solvent distilled off. This gave 6.8 g (0.030 mol, 26%) of solid.

out

in g 78.8 g

Fest¬

108.7

(1: 1) 10

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237.6 g (1.1 mol) 2,3-Dichloro-5-trifluormethyl-pyridin wurden in 1.4 I Ethanol gelöst, und 550 g (1 1 mol) Hydrazini- umhydrat, gelöst in 600 ml Ethanol, schnell zugetropft. Nach 12 h Rühren wurde das Lösungsmittel abdestilliert, der Rückstand mit 1.5 I Wasser versetzt, abgesaugt, mit Was¬

237.6 g (1.1 mol) of 2,3-dichloro-5-trifluoromethyl-pyridine were dissolved in 1.4 l of ethanol, and 550 g (1 1 mol) of hydrazine hydrate dissolved in 600 ml of ethanol were added dropwise rapidly. After stirring for 12 h, the solvent was distilled off, the residue was combined with 1.5 l of water, filtered off with suction, washed with water

Washed 188 and dried: 214.8 g (1.0 mol, 92%) of solid.

9.9 g (0.047 mol) of the solid thus obtained were initially charged in 100 ml of tert-butanol, 10.5 g (0.094 mol) of potassium tert-butylate and, after 30 minutes, a solution of 4.3 g (0.05 mol) of ethyl propiolate in 15 ml of tert-butanol was added ,

stand mit Methyltertbutylether gewaschen, in Wasser aufgenommen, abgesaugt und getrocknet. Man erhielt 68.2 g (0.02 mol, 42 %) Zielprodukt.After 2 h, the solvent was distilled off, the reverse

washed with methyl tert-butyl ether, taken up in water, filtered off with suction and dried. 68.2 g (0.02 mol, 42%) of the target product were obtained.

22.6 g (0.2 mol) of phenylhydrazine were initially charged in 200 ml of methanol and 35 g (0.22 mol) of ethyl 2-methylacetoacetate in 1 ml of acetic acid were added at room temperature. After stirring for 2 h, a solution of 12 g (0.22 mol) of sodium methylate in 300 ml of methanol was added dropwise, 12 h

Essigsäure auf pH 7 gestellt. Der entstandene Niederschlag wurde abgesaugt und man erhielt 23.7 g (0.126 mol, 63 %) eines hellen Öls.19 stirred and the solvent distilled off. The residue was taken up in 800 ml of water, filtered off, with 10 ml

Acetic acid adjusted to pH 7. The resulting precipitate was filtered off with suction to give 23.7 g (0.126 mol, 63%) of a pale oil.

Example of the stabilizing effect in acrylic acid

Ppm and percentages used in this specification refer, unless otherwise indicated, to percentages by weight and ppm.

0.5 ml of freshly thawed acrylic acid, which had been distilled twice to remove the storage stabilizer, were filled under an air atmosphere into 1.8 ml ampoules.

All samples were stored in a convection oven at 120 ° C.

In each test series, 3 ampoules of each acrylic acid sample were filled and tested, the mean of the time until complete polymerization was visually recorded.

The average standard deviation within a test series was approximately 2 - 4%. Unless otherwise stated, concentrations were 25 ppm aromatic heterocycle plus 10 ppm phenothiazine (PTZ).

The relative effectiveness is calculated from the quotient of the time to polymerization of the sample of aromatic heterocycle and PTZ and the time to polymerization of the reference sample. As a reference sample, pure PTZ was used, the relative effectiveness of the reference sample is therefore 1, 0.

The results are summarized in Table 1.

Table 1

Claims

claims 1. containing mixture (A) at least one aromatic heterocycle of the general formula

wherein W, X and Y are independent Hydrogen, NR ¹ R ² , OR ³ , PR ₂ ⁴ , PR ⁴ R ⁶ , SR ⁵ , d-Cao-alkylcarbonyl, Ci-C ₂₀ - alkoxycarbonyl, C ₂ -C ₂₀ alkenyl, C ₂ -C ₂₀ Alkenylcarbonyl, C ₂ -C ₂₀ -alkynyl, C ₂ -C ₂₀ -alkynylcarbonyl, C ₃ -C 15 -cycloalkyl, C ₃ -C 6 -cycloalkylcarbonyl, aryl, arylcarbonyl, a heterocycle, aryl, a halogen atom, or C ₁ -C 4 _20- alkyl, where in the Ci-C ₂₀ - Al-kylgruppe more or all hydrogen atoms may be replaced by fluorine atoms or one or more of the hydrogen atoms may be replaced by SR ⁵ may be, and wherein R ¹ and R ^{2 have} the meaning mentioned below, and R ³ to R ⁶ also Hydrogen, C 1 -C ₂₀ -alkyl, C 1 -C ₂₀ -alkylcarbonyl, C 1 -C ₂₀ -alkoxycarbonyl, C ₂ -C ₂₀ alkenyl, C ₂ -C ₂₀ alkenylcarbonyl, C ₂ -C ₂₀ kinyl -alkyl, C ₂ -C ₂₀ alkynylcarbonyl, C3-Ci5-cycloalkyl, Cs-Cis-cycloalkylcarbonyl, aryl, arylcarbonyl, a Heterocycle or a halogen atom, Z can be hydrogen, C 1 -C ₂₀ -alkyl, C 3 -C 6 -cycloalkyl, aryl or a heterocycle, and R ¹ and R ² can independently of one another be hydrogen, NR ⁴ R ⁵ , OR ³ , PR ₂ ⁴ , PR ⁴ R ⁶ , SR ⁵ , C 1 -C ₂₀ -alkyl, C 1 -C ₂₀ -alkylcarbonyl, C 1 -C ₂₀ -alkoxycarbonyl . C ₂ -C ₂₀ alkenyl, C ₂ -C ₂₀ alkenylcarbonyl, C ₂ -C ₂₀ kinyl -alkyl, C ₂ -C ₂₀ -alkyl kinyl- carbonyl, C3-Cis-cycloalkyl, Cs-Cis-cycloalkylcarbonyl, aryl, be, and wherein R ³ to R ⁶ is also hydrogen, Ci-C ₂₀ alkyl, C ₂₀ alkyl carbonyl, C ₂₀ alkoxycarbonyl, C ₂ -C ₂₀ alkenyl, arylcarbonyl, a heterocycle or a halogen atom, C ₂ -C ₂₀ alkenylcarbonyl, C ₂ -C ₂₀ -alkynyl, C ₂ -C ₂₀ -alkynylcarbonyl, C ₃ -C 6 -cycloalkyl, C ₁ -C 6 -cycloalkylcarbonyl, aryl, arylcarbonyl, a heterocycle or a halogen atom , and (B) at least one polymerizable compound. 2. Mixture according to claim 1, wherein in formula (I) W, X and Y are hydrogen, NR ¹ R ² , OR ³ , C 1 -C 20 -alkyl, C 2 -C 20 -alkenyl or a halogen atom, with the proviso that im Case of NR ¹ R ² R ¹ and R ^{2 are the} same and are hydrogen or C 1 -C 20 -alkyl, and in the case of OR ³ R ^{3 is} hydrogen or C 1 -C 20 -alkyl. 3. Mixture according to claim 1 or 2 1 or 2, wherein in formula (I) Z is hydrogen, OR ³ , Ci-C ₂ o-alkyl, Ci-C ₂ o-alkylcarbonyl or Ci-C ₂ o-alkoxycarbonyl, with of the Provided that in the case of OR ³ R ^{3 is} hydrogen or Ci-C2o-alkyl. 4. Mixture according to one of claims 1 to 3, characterized in that R ¹ and R ^{2 are the} same and are hydrogen, C 1 -C 20 -alkyl, C 1 -C 20 -alkylcarbonyl or C 1 -C 20 -alkoxycarbonyl. 5. Mixture according to one of the preceding claims, containing 0.1 to 1000 ppm of the aromatic heterocycle 'of the formula (I) or of a mixture of aromatic heterocycles of the formula (I) based on the polymerizable compound. 6. Mixture according to one of the preceding claims, comprising at least one co-stabilizer or another stabilizer. 7. Mixture according to claim 6, wherein the costabilizer is selected from Group of oxygen-containing gases, phenolic compounds, quinones and hydroquinones, N-oxyl compounds, aromatic amines, phenylenediamines, imines, sulfonamides, oximes, hydroxylamines, urea derivatives, phosphorus-containing compounds, sulfur-containing compounds, complexing agents based on tetraazannulen and metal salts, and optionally mixtures thereof. 8. Mixture according to claim 6 or 7, characterized in that as a costabilizer phenothiazine, hydroquinone, hydroquinone monomethyl ether, 2,2,6,6-tetramethyl-piperidine-N-oxyl, 4-hydroxy-2,2,6,6- tetramethyl-piperidine-N-oxyl, 4-oxo-2,2,6,6-tetramethyl-piperidine-N-oxyl, N, N'-di-sec-butyl-p-phenylenediamine, cerium (III) acetate, cerium (III) ethylhexanoate, oxygen-containing gases and / or mixtures thereof. 9. Mixture according to one of the preceding claims, characterized in that the polymerizable compound contains at least one ethylenically unsaturated group. 10. Mixture according to claim 9, characterized in that the polymerizable compound is selected from the group of mono-, di- or triethyle- nisch unsaturated C3-Cs-carboxylic acids, Ci-C2o-esters, amides, nitriles and -Anhydride this mono-, di- or triethylenisch unsaturated C3-Cs-carboxylic acids, vinyl esters of carboxylic acids containing up to 20 carbon atoms, vinyl ethers of alcohols containing 1 to 10 carbon atoms, vinyl aromatics and heteroaromatics with up to 20 C atoms, vinyl lactams having 3 to 10 C atoms in the ring, open-chain N-vinyl amide compounds and N-vinylamine compounds, vinyl halides, aliphatic optionally halogenated hydrocarbons having 2 to 8 C atoms and 1 or 2 double bonds, vinylidenes or mixtures of these monomers , 1 1. A mixture according to claim 9 or 10, comprising as a polymerizable compound mono-, di- or triethylenisch unsaturated C3-Cs-carboxylic acids, C1-C20- esters of these mono-, di- or triethylenisch unsaturated C3-Cs-carboxylic acids, Vinyl esters of carboxylic acids containing up to 20 carbon atoms, vinyl ethers of alcohols containing from 1 to 10 carbon atoms, vinylaromatics and heteroaromatics having up to 20 carbon atoms, vinyl lactams having from 3 to 10 carbon atoms in the ring, open-chain N-vinylamide compounds or N-vinyl amine compounds. A mixture according to any one of claims 9 to 11, containing as the polymerizable compound (meth) acrylic acid, (meth) acrylic acid ester, N-vinylcaprolactam, N-vinylformamide, N-vinylimidazole, N-vinylpyrrolidone, vinylphosphoric acids, N-vinylcarbazole, N, N-divinylethyleneurea Trimethylolpropane triacrylate, uromethyl methacrylate, styrene, butadiene or isoprene. 13. vessel containing a continuous liquid phase and a continuous gas phase, wherein the continuous liquid phase consists of the mixture according to one of claims 1 to 12 and the continuous gas phase consists of an oxygen-containing gas. 14. A vessel according to claim 13, wherein the oxygen-containing gas is mixtures containing oxygen and nitrogen, in particular air or air-nitrogen mixtures. 15. Polymers prepared by polymerization of a mixture according to any one of claims 1 to 12.