DE10346135A1 - Stabilizer mixture, useful for the stabilization of polymerizable compounds against polymerization, comprises at least one radical trap containing glycerol units and at least one other (co)stabilizer - Google Patents

Abstract

A stabilizer mixture (I) comprises at least one radical trap containing at least two glycerol units with the proviso that it is not ethylenediamine tetraacetic acid (EDTA), diethylenetriamine pentaacetic acid (DTPA), trans-1,2-cyclohexane diamine tetraacetic acid (CYDTA) or their alkali or alkaline earth salts, and at least one other stabilizer or costabilizer. Independent claims are included for: (1) a mixture (II) comprising a stabilizer mixture (I) and at least one polymerizable compound; and (2) a process for the stabilization of polymerizable compounds during processing, storage and/or transport by use of the radical trap.

Description

The present invention describes the use of radical scavengers for stabilizing polymerizable compounds against polymerization.

It is known that polymerizable compounds through heat or exposure to light or peroxides easily for polymerization can be brought. However, since in the manufacture, processing, storage and / or transport the polymerization is reduced for safety and economic reasons or needs to be reduced, there is a constant need for new, effective ones Polymerization inhibitors.

This is particularly problematic chemical and / or physical processing during processing, such as by distillation or rectification, and subsequently storage and transportation.

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

In GB-A 1 601 979 describes the stabilization of an aqueous solution of a (meth) acrylate salt with a nitrosophenolate in the presence of EDTA as a chelator.

In US 4,929,660 discloses an adhesive composition that contains a radical acrylic monomer and a polymerization inhibitor, a metal chelator, and a radical scavenger. This radical scavenger is an N, N-dialkyl or N, N-diarylalkylhydroxylamine.

The stabilization of unsaturated quaternary ammonium salts in the presence of metal scavengers is described in US 5,912,383 described. These metal scavengers can be diethylenetriaminepentaacetic acid and N- (hydroxyethyl) ethylenediaminetriacetic acid as well as the associated sodium salts.

In the German patent application DE-A 199 20 796 describes a process for the preparation of isobornyl (meth) acrylate by reacting camphene with (meth) acrylic acid, which is also carried out in the presence of a chelating agent. As a chelating agent, this document discloses nitrilotriacetic acid, ethylenediaminetetraacetic acid, N- (2-hydroxyethyl) ethylenediaminetriacetic acid, 1,2-cyclohexylenedinitrilotetraacetic acid, diethylenetriaminepentaacetic acid, 3,6-dioxaoctamethylenedinitrilotetraacetic acid and the alkali metal salts of these.

WO 02 / 2668.5 describes the stabilization of acrylic monomers during the distillation with a stabilizer in the presence of oxygen with a metal scavenger which is selected from ethylenediaminetetraacetic acid (EDTA), diethylenetriaminepentassetic acid (DTPA) and their Na salt (Na ₅ DTPA) and trans-1 , 2-Cyclohexandiaminpentaessigsäure. These metal traps are used to complex free iron.

The Japanese patent application JP 05-295011 and JP 05-320205 also describe those of acrylic acid in the presence of EDTA, DTPA, CYDTA and their alkali salts.

Object of the present invention was therefore an alternative method for stabilizing polymerizable compounds against polymerization during processing, storage and / or transport to disposal to deliver.

The task was solved by a method for stabilizing polymerizable compounds against Polymerization during processing, storage and / or transport, wherein at least one radical scavenger, containing at least two glycine units is used with which proviso that the radical scavenger is not selected is from ethylenediaminetetraacetic acid (EDTA), diethylenetriaminepentaacetic acid (DTPA), trans-1,2-cyclohexanediaminediamine tetraacetic acid (CYDTA) and their alkali and alkaline earth salts.

worin R, R' unabhängig voneinander Wasserstoff oder Metall sein können. Beispielsweise handelt es sich bei diesen Metallen um Alkalimetalle wie Natrium oder Kalium.In a preferred embodiment, at least one radical scavenger is used which contains at least two glycine units, with the proviso that the radical scavenger does not have ≥ 2 of the following structural units:

wherein R, R 'can independently be hydrogen or metal. For example, these metals are alkali metals such as sodium or potassium.

In a particularly preferred embodiment one uses at least radical scavengers, the at least two glycine units and contains at least one amide and / or ester unit. Prefers points out the radical scavenger two amide units.

Radical scavengers of the general formula (I) are very particularly preferably used:

In particular, these can be:
G ¹ can be NR ³ R ⁴ or OR ⁷ and G ² can be NR ⁵ R ⁶ or OR ⁸ .

X can be C ₁ -C ₂₀ alkyl, NCH ₂ COOR ⁹ , NR ¹⁰ , O, S, PR ¹¹ , Se, SiOR ¹² R ¹³ or aryl, the substituents mentioned preferably being in any position, but not more than five times cannot be substituted more than four times, particularly preferably not more than three times, by one or more heteroatoms and / or halogen atoms. X is preferably a C ₁ -C ₂₀ alkyl group or NCHCOOR ⁹ , particularly preferably X is a C ₁ -C ₁₀ alkyl group or NCHCOOR ⁹ .

k, l, m and n are independent of each other 0 to 20. l and m are preferably in the range from 0 to 10, particularly preferably from 0 to 5, very particularly preferably from 0 to 3 and particularly preferably 0 to 2. k and n preferably have the same Value, e.g. B. in the range from 0 to 10, preferably from 0 to 5, entirely particularly preferably from 1 to 3, in particular k and n have the Value 1.

• a) im Falle der genannten aliphatischen Substituenten die Reste R³ und R⁴ beziehungsweise R⁵ und R⁶ auch miteinander verbunden sein können und so gemein sam einen drei- bis achtgliedrigen, bevorzugt einen fünf- bis siebengliedrigen und besonders bevorzugt einen fünf- bis sechsgliedrigen Ring bilden können,
• b) die genannten aliphatischen Substituenten geradkettig oder verzweigt sein können,
• c) die Substituenten jeweils an beliebiger Position durch ein oder mehrere Heteroatome unterbrochen sein können, wobei die Anzahl dieser Heteroatome nicht mehr als 10 beträgt, bevorzugt nicht mehr als 8, besonders bevorzugt nicht mehr als 5 und insbesondere nicht mehr als 3, und/oder
• d) die Substituenten jeweils an beliebiger Position, allerdings nicht mehr als fünfmal, bevorzugt nicht mehr als viermal und besonders bevorzugt nicht mehr als dreimal durch Alkyl, Alkyloxy, Alkyloxycarbonyl, Aryl, Aryloxy, Aryloxycarbonyl, Hydroxycarbonyl, Aminocarbonyl, Heterocyclen, Heteroatome oder Halogenatome substituiert sein können, wobei diese ebenfalls maximal zweimal, bevorzugt maximal einmal mit den genannten Gruppen substituiert sein können.

The radicals R ¹ to R ⁸ can have the following meanings:
R ¹ to R ⁶ can independently of one another be hydrogen, C ₁ -C ₂₀ alkyl, C ₁ -C ₂₀ alkylcarbonyl, 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 ₅ -C ₁₅ cycloalkylcarbonyl, aryl, arylcarbonyl or heterocycles,
R ⁷ and R ⁸ can independently of one another be C ₁ -C ₂₀ alkyl, C ₁ -C ₂₀ alkylcarbonyl, 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 ₅ -C ₁₅ -cycloalkylcarbonyl, aryl, arylcarbonyl or heterocycles,
in which

• a) in the case of the aliphatic substituents mentioned, the radicals R ³ and R ⁴ or R ⁵ and R ^{6 can} also be linked to one another and so together a three- to eight-membered, preferably a five- to seven-membered and particularly preferably a five- to six-membered Can form a ring
• b) the aliphatic substituents mentioned can be straight-chain or branched,
• c) the substituents can be interrupted at any position by one or more heteroatoms, the number of these heteroatoms being not more than 10, preferably not more than 8, particularly preferably not more than 5 and in particular not more than 3, and / or
• d) the substituents are substituted in any position, but not more than five times, preferably not more than four times and particularly preferably not more than three times by alkyl, alkyloxy, alkyloxycarbonyl, aryl, aryloxy, aryloxycarbonyl, hydroxycarbonyl, aminocarbonyl, heterocycles, heteroatoms or halogen atoms can be, which can also be substituted at most twice, preferably at most once, with the groups mentioned.

R ⁹ to R ¹³ are optionally, independently of one another, hydrogen or C ₁ -C ₂₀ -alkyl.

The collective terms given for the various radicals R have the following meanings:
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-methylpentyl, 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.

C ₁ -C ₂₀ 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 C ₁ -C ₁₀ 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-butenyl, 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-l-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-pentenyl, 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-ti-methyl-2-propenyl, 1-ethyl-1-methyl-2-propenyl, 1-ethyl-2-methyl-1-propenyl and 1-ethyl-2-methyl- 2-propenyl, and 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 ₂₀ -alkylcarbonyl such as ethenoyl, propenoyl, butenoyl, pentenoyl, nonenoyl and their isomers.

C ₂ -C ₂₀ alkynyl: straight-chain or branched hydrocarbon groups with 2 to 20 carbon atoms and a triple bond in any position, preferably C ₂ -C ₂₀ 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 -butinyl, 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-butynyl, 1-ethyl-2-butynyl, 1-ethyl-3-butynyl, 2-ethyl-3-butynyl and 1-ethyl-1 -methyl-2-propynyl and the isomers of heptinyl, 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 bonded via a carbonyl group (-CO-), preferably C ₂ -C ₁₀ Alkynylcarbonyl such as propinoyl, butinoyl, pentinoyl, noninoyl, decinoyl and their isomers.

C ₃ -C ₁₅ cycloalkyl: monocyclic, saturated hydrocarbon groups with 3 to 15 carbon ring members, preferably C ₃ -C ₈ cycloalkyl such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl and cyclooctyl as well as a saturated or unsaturated cyclic system such as e.g. B. norbornyl or norbenyl.

C ₃ -C ₁₅ cycloalkylcarbonyl: monocyclic, saturated hydrocarbon groups with 3 to 15 carbon ring members (as mentioned above) which are via a carbonyl group (-CO-), preferably C ₃ -C ₈ cycloalkylcarbonyl.

Aryl: a single to trinuclear aromatic Ring system containing 6 to 14 carbon ring members, e.g. B. phenyl, Naphthyl and anthracenyl, preferably a one to two nucleus, particularly preferably a mononuclear aromatic ring system.

Arylcarbonyl: preferably a single to trinuclear aromatic ring system (as mentioned above), which via a Carbonyl group (-CO-) is bound to, such as. B. benzoyl, preferred a one to two core, particularly preferably a single core 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 having several Ring-containing ring system such as furyl, thiophenyl, Pyrryl, pyridyl, indolyl, benzoxazolyl, dioxolyl, dioxyl, benzimidazolyl, Benzthiazolyl, dimethylpyridyl, methylquinolyl, dimethylpyrryl, Methoxyfuryl, dimethoxypyridyl, difluoropyridyl, methylthiophenyl, Isopropylthiophenyl or tert-butylthiophenyl.

The substituents listed in detail can as described above at any position with an or several heteroatoms are interrupted, the number of these heteroatoms not more than 10, preferably not more than 8, very particularly preferred is not more than 5 and in particular not more than 3, and / or preferred in any position, but not more than five times not more than four times, and particularly preferably not more than three times, by alkyl, alkyloxy, alkyloxycarbonyl, aryl, aryloxy, aryloxycarbonyl, Hydroxycarbonyl, aminocarbonyl, heterocycles, heteroatoms or halogen atoms substituted could be, these also being at most twice, preferably at most once can be substituted with the groups mentioned.

The connection classes mentioned in this group Alkyl, aryl and heterocycles have the meaning given above.

Heteroatoms are oxygen, nitrogen, Sulfur or phosphorus.

Alkyloxy means 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 such as for example methoxy, ethoxy, propoxy.

Alkoxycarbonyl is an alkoxy group with 1 to 20 carbon atoms (as mentioned above), which is bonded via a carbonyl group (-CO-), preferably C ₁ -C ₁₀ alkyloxycarbonyl.

Aryloxy is a single to trinuclear aromatic ring system (as mentioned above), which via a Oxygen atom (-O-) is bonded to, preferably a mononuclear or dinuclear, a mononuclear aromatic ring system is particularly preferred.

Aryloxycarbonyl is a one to trinuclear aryloxy group (as mentioned above), which via a Carbonyl group (-CO-) is bonded to, preferably a one to two-ringed, a mononuclear aryloxycarbonyl is particularly preferred.

Halogen atoms are fluorine, chlorine, bromine and iodine.

The radicals R ¹ and R ² are preferably the same and are hydrogen or C ₁ -C ₂₀ alkyl, particularly preferably hydrogen or C ₁ -C ₁₀ alkyl, very particularly preferably hydrogen or C ₁ -C ₆ alkyl.

The radicals R ³ and R ⁵ are preferably the same and are hydrogen, C ₁ -C ₂₀ alkyl or C ₁ -C ₂₀ alkylcarbonyl, particularly preferably hydrogen, C ₁ -C ₁₀ alkyl or C ₁ -C ₁₀ alkylcarbonyl, very particularly preferably hydrogen, C ₁ -C ₆ alkyl or C ₁ -C ₆ alkylcarbonyl.

The radicals R ⁴ and R ⁶ or R ⁷ and R ⁸ are preferably the same and are C ₁ -C ₂₀ alkyl, C ₁ -C ₂₀ alkylcarbonyl, aryl, C ₂ -C ₂₀ alkenyl, C ₂ -C ₂₀ - Alkenylcarbonyl, C ₂ -C ₂₀ alkynyl or C ₂ -C ₂₀ alkynylcarbonyl. As described above, the radicals can be interrupted at any position by one or more heteroatoms, the number of these heteroatoms not more than 10, preferably not more than 8, very particularly preferably not more than 5 and in particular not more than 3, and / or in each case at any position, but not more than five times, preferably not more than four times and particularly preferably not more than three times, by alkyl, alkyloxy, alkyloxycarbonyl, aryl, aryloxy, aryloxycarbonyl, hydroxycarbonyl, aminocarbonyl, heterocycles, heteroatoms or halogen atoms can, which can also be substituted at most twice, preferably at most once, with the groups mentioned.

Particularly preferred radicals R ⁴ and R ⁶ or R ⁷ and R ⁸ are selected from phenyl, benzyl, p-methoxyphenyl, o-, m- or p-hydroxyphenyl, 1-hydroxyhexyl, methyl, ethyl, propyl, butyl, ethylene glycol, diethylene glycol , Triethylene glycol, ethoxylate with 4 to 10 EO units, ethylenediamine, diethylenetriamine, triethylenetetraamine and amino acids such as alanine, valine, leucine, isoleucine, proline, tryptophan, phenylalanine, methionine, glycine, serine, tyrosine, threonine, cysteine, asparagine , Aspartic or glutamic acid, lysine, arginine or histidine.

For example, R ⁴ and R ⁶ or R ⁷ and R ^{8 can be} the radicals mentioned in Table 1.

Table 1

Of course, all combinations are of said substituents R and X with the numbers given for k, l, m and n possible.

Table 2 shows the preferred ones Individuals of the formula (I) are summarized.

Table 2

These compounds are prepared, for example, analogously to that in DE-A 101 05 014 and CH-A 569 405 described synthetic routes. The compounds disclosed therein are used as metal complexes in the case of metal phenomena or as contrast agents in diagnostics. A general synthetic route is disclosed in Bioorganic Medicinal Chemistry Letters 2001, 11, 2573.

Usually become the radical scavengers used individually or as a mixture, preferably not more than five, particularly preferably not more than four and very particularly preferably not more than three of the radical scavengers mentioned above are used.

The amount in which the radical scavengers according to the invention are used to have a stabilizing effect on the polymerizable compound exercise, are more common within the framework Attempts to determine.

For example, from 0.1 to 1000 ppm of a radical scavenger or a radical scavenger mixture based on the polymerizable Compound used, preferably 1 to 900 ppm, particularly preferably 10 to 800 ppm, very particularly preferably 50 to 700 ppm and in particular 100 to 500 ppm.

According to the invention, the free radical scavengers can advantageously be used together with at least one other compound known as a stabilizer and / or costabilizer. These are e.g. B. in the older German patent application with the file number 102 49 507.6 and in DE-A 102 58 329 . DE-A 198 56 565 and in EP-A 765 856 described.

Oxygenated ones come as costabilizers Gases, phenolic compounds, quinones and hydroquinones, N-oxyl compounds, aromatic amines and phenylenediamines, imines, sulfonamides, oximes, Hydroxylamines, urea derivatives, phosphorus-containing compounds, sulfur-containing compounds, complexing agents based on tetraazaannulene (TAA) and / or metal salts, and optionally mixtures thereof in question.

For example, oxygen-containing gases be gases with an oxygen content between 0.1 and 100 % By volume, preferably from 0.5 to 50% by volume and particularly preferably from Have 1 to 25 vol .-%. For example, nitrogen monoxide, Nitrogen dioxide, oxygen or nitrous oxide or air. these can individually, in any mixture with each other or with another Mixed gas, for example nitrogen, noble gases, water vapor, Carbon monoxide, carbon dioxide or lower alkanes are preferred are air or air-nitrogen mixtures.

Phenolic compounds are e.g. B: phenol, alkylphenols, for example o-, m- or p-cresol (methylphenol), 2-tert-butyl-4-methylphenol, 6-tert-butyl-2,4-dimethylphenol, 2,6-di- 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'-methylene-bis- (6-tert-butyl-4-methylphenol), 4,4'-oxydiphenyl, 3,4-methylenedioxydiphenol (sesamol), 3,4 -Dimethylphenol, pyrocatechol (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, nonylphenol [CAS-No. 11066-49-2], 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 ^® of BASF Aktiengesellschaft, 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-β- (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 [β- (3,5, -di-tert-butyl-4-hydroxyphenyl) propionate], 2,6-di-tert-butyl-4-dimethylaminomethylphenol, 6 sec. butyl-2, 4-dinitrophenol, Irganox ^® 565, 1010, 1076, 1141, 1192, 1222 and 1425 from Ciba Specialty Chemicals, 3- (3 ', 5'-di-tert-butyl-4'-hydroxyphenyl) propionate, 3- ( 3 ', 5'-Di-tert-butyl-4'-hydroxyphenyl) propionic acid hexadecyl ester, 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-dioxa-1,11-undecanediol-bis - [(3', 5'- di-tert-butyl-4'-hydroxyphenyl) propionate], 4,8-dioxa-1,11-undecanediol-bis - [(3'-tert-butyl-4'-hydroxy-5'-methylphenyl) propionate ], 1,9-nonanediol-bis - [(3 ', 5'-di-tert-butyl-4'-hydroxyphenyl) propionate], 1,7-heptane diamine-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- (5th '-tert.-butyl-4'-hydroxy-2'-methylphen-1'-yl) butane and tert-butylcatechol, as well as aminophenols, such as z. B. p-aminophenol, nitrosophenols, such as. B. p-nitrosophenol, p-nitroso-o-cresol, alkoxyphenols, for example 2-methoxyphenol (guaiacol, catechol 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-methoxybenzaldehyde (vanillin ), 4-hydroxy-3-ethoxybenzaldehyde (ethylvanillin), 3-hydroxy-4-methoxybenzaldehyde (iso-vanillin), 1- (4-hydroxy-3-methoxyphenyl) ethanone (acetovanillon), eugenol, dihydroeugenol, isoeugenol, tocopherols, such as B. α-, β-, γ-, δ- and ε-tocopherol, tocol, α-tocopherol hydroquinone, and 2,3-dihydro-2,2-dimethyl-7-hydroxybenzofuran (2,2-dimethyl-7-hydroxycoumaran ).

When are quinones and hydroquinones for example suitable hydroquinone or hydroquinone monomethyl ether (4-methoxyphenol), methyl hydroquinone, 2,5-di-tert-butyl hydroquinone, 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-bisphenylamino-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, Coerulignon, 3,3'-di-tert-butyl-5,5'-dimethyldiphenoquinone, p-rosolic acid (Aurine), 2,6-di-tert-butyl-4-benzylidene-benzoquinone, 2,5-di-tert-amylhydroquinone.

As N-oxyls (nitroxyl or N-oxyl radicals, compounds which have at least one> NO • group) are, for. B. suitable 4-hydroxy-2,2,6,6-tetramethyl-piperidine-N-oxyl, 4-oxo-2,2,6,6-tetramethyl-piperidine-N-oxyl, 4-methoxy-2,2 , 6,6-tetramethyl-piperidine-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-tetramethyl-piperidine-N-oxyl) phosphite, 3-oxo-2,2,5,5-tetramethyl- pyrrolidine-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) ester, bis (1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl) n-but ylmalonate, bis- (1-oxy1-2,2,6,6-tetramethylpiperidin-4-yl) phthalate, bis- (1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl) isophthalate, bis- (1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl) terephthalate, bis (1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl) hexahydroterephthalate, N, N'-bis - (1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl) adipinamide, N- (1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl) caprolactam, N- (1- Oxyl-2,2,6,6-tetramethylpiperidin-4-yl) dodecylsuccinimide, 2,4,6-tris- [N-butyl-N- (1-oxyl-2,2,6,6-tetramethylpiperidin-4- yl] triazine, N, N'-bis (1-oxy1-2,2,6,6-tetramethylpiperidin-4-yl) -N, N'-bis-formyl-1,6-diaminohexane, 4,4 ' -ethylene-bis (1-oxyl-2,2,6,6-tetramethylpiperazin-3-one).

Suitable aromatic amines or phenylenediamines are, for example, N, N-diphenylamine, N-nitrosodiphenylamine, nitrosodiethylaniline, p-phenylenediamine, N, N'-dialkyl-p-phenylenediamine, where the alkyl radicals can be the same or different and in each case independently of one another is 1 to 4 carbon atoms and may be straight or branched, for example N, N'-di-iso-butyl-p-phenylenediamine, N, N'-di-iso-propyl-p-phenylenediamine, Irganox ^® 5057 from Ciba specialty Chemicals , 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, imoinodibenzyl, N, N'-diphenylbenzidine, N-phenyltetraaniline, acridone, 3-hydroxydiphenylamine, 4-hydroxydiphenylamine.

Imines are e.g. B. methylethylimine, (2-hydroxyphenyl) benzoquinone imine, (2-hydroxyphenyl) benzophenone imine, N, N-dimethylindoaniline, thionine (7-amino-3-imino-3H-phenothiazine), methylene violet (7-dimethylami no-3-phenothiazinon).

Sulfonamides which act as stabilizers 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 in DE-A 102 58 329 ,

Oximes can be, for example, aldoximes, ketoximes or amidoximes, for example in DE-A 101 39 767 described, preferably diethyl ketoxime, acetone oxime, methyl ethyl ketoxime, cyclohexanone oxime, benzaldehyde oxime, benzil dioxime, dimethyl glyoxime, 2-pyridine doxime, salicylaldoxime, phenyl-2-pyridyl ketoxime, 1,4-benzoquinone dioxime, 2,3-butanedione dioxime, 2,3-butanedione mono Fluorenone oxime, 4-tert-butyl-cyclohexanone oxime, N-ethoxy-acetimidic acid ethyl ester, 2,4-dimethyl-3-pentanone oxime, cyclododecanone oxime, 4-heptanone oxime and di-2-furanylethanedione dioxime or other aliphatic or aromatic oximes or their reaction products with alkyl transfer reaction products such as B. alkyl halides, triflates, sulfonates, tosylates, carbonates, sulfates, phosphates or the like.

Hydroxylamines are e.g. B. N, N-diethylhydroxylamine and those registered in the international application with the file number PCT / EP / 03/03139 are disclosed.

Examples of urea derivatives are suitable urea or thiourea.

Are phosphorus-containing compounds z. B. triphenylphosphine, triphenylphosphite, hypophosphorous acid, trinonylphosphite, Triethyl phosphite or diphenyl isopropyl phosphine.

As sulfur-containing compounds Diphenyl sulfide, phenothiazine and sulfur-containing are suitable, for example Natural substances such as cysteine.

Complexing agent based on tetraazannules (TAA) are e.g. B. Diebenzotetraaza [14] annulene and porphyrins such as them in Chem. Soc. Rev. 1998, 27, 105-115.

Metal salts are e.g. B. 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, Pyrocatechol (1,2-dihydroxybenzene), 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-tetramethyl-piperidine-N-oxyl, 4-hydroxy-2,2,6,6-tetramethyl-piperidine-N-oxyl, 4-oxo-2,2,6,6 tetramethyl-piperidine-N-oxyl as well as manganese (II) acetate, cerium (III) carbonate, cerium (III) acetate or cerium (III) ethylhexanoate, Cerium (III) stearate and mixtures thereof in different compositions.

Air, air-nitrogen mixtures are particularly preferred, 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, hydrochi nonmonomethyl ether or Methylhydroquinone, 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 and cerium (III) acetate or cerium (III) ethylhexanoate and mixtures of at least two of the components mentioned.

Air is particularly preferred, 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-tetramethyl-piperidine-N-oxyl, N, N'-di-sec.-butyl-p-phenylenediamine, cerium (III) acetate or Cerium (III) ethylhexanoate and mixtures thereof.

The type of addition of the stabilizer according to the invention and the costabilizers to be used where appropriate is not restricted. The added stabilizer according to the invention can be added individually or as a mixture with further stabilizers according to the invention and / or with the aforementioned costabilizers, in liquid or in dissolved form in a suitable solvent, which solvent itself can be a stabilizer, such as. B. in DE-A 102 00 583 described. Also suitable as solvents are, for example, material flows from the preparation of the polymerizable compound. For example, the pure products, ie the polymerizable compounds, can be used in a purity of generally 95% or more, preferably 98% or more and particularly preferably 99% or more, but also the starting materials used to prepare the polymerizable compounds, in a purity of 95% or more, preferably 98 or more and particularly preferably 99% or more, or those streams which contain starting materials and / or products and / or intermediates and / or by-products.

The concentration of the used solutions is only by solubility of the stabilizer / stabilizer mixture in the solvent limited, for example it can be 0.1–50 % By weight, preferably 0.2-25 % By weight, particularly preferably 0.3-10 % By weight and very particularly preferably 0.5-5% by weight.

Of course, the radical scavengers or Radical scavenger mixtures can also be used as a melt, for example if the melting point below 120 ° C, preferably below 100 ° C, particularly preferably below 80 ° C and especially below 60 ° C is.

In a further preferred form, the radical scavengers or radical scavengers according to the invention Mixtures used as a melt with a phenol with a melting point below 120 ° C, preferably below 100 ° C, particularly preferably below 80 ° C and in particular below 60 ° C as a costabilizer. 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-dimethylphenol, hydroquinone and hydroquinone monomethyl ether.

As previously described, 0.1 up to 1000 ppm of the radical scavenger according to the invention or a mixture of radical scavengers based on the polymerizable Connection used. Is a mixture of radical scavengers according to the invention Costabilizers used, 0.1 to 5000 ppm, are preferred 1 to 4000 ppm, particularly preferably 5 to 2500 ppm, particularly preferred 10 to 1000 ppm and in particular 50 to 750 ppm based on the polymerizable Connection used.

Will be a mixture of several stabilizers or costabilizers used, they can both independently at different or the same dosing points as well independently be dissolved from each other in different solvents.

According to the invention, the stabilizers / stabilizer mixtures preferably used in places where the polymerizable compound, for example due to high purity, high retention time and / or high Temperature, a risk of polymerization is exposed.

This can include absorption units, Desorption units, rectification units, for example distillation apparatus or rectification columns, evaporators, for example natural or forced circulation evaporators, Capacitors or vacuum units.

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

The radical scavengers to be used according to the invention can both can be used as a storage and transport stabilizer, d. H. to stabilize the pure polymerizable compounds.

• i) wenigstens einen Radikalfänger, der mindestens zwei Glycineinheiten enthält, mit der Maßgabe, dass der Radikalfänger nicht ausgewählt ist aus Ethylendia mintetraessigsäure (EDTA), Diethylentriaminpentaessigsäure (DTPA), trans-1,2-Cyclohexandiamintetraessigsäure (CYDTA) und deren Alkali- und Erdalkalisalze und
• ii) wenigstens einen weiteren Stabilisator oder Costabilisator.

The invention furthermore relates to stabilizer mixtures comprising

• i) at least one radical scavenger which contains at least two glycine units, with the proviso that the radical scavenger is not selected from ethylenediaminetetraacetic acid (EDTA), diethylenetriaminepentaacetic acid (DTPA), trans-1,2-cyclohexanediamine tetraacetic acid (CYDTA) and their alkali metal and alkaline earth metal salts and
• ii) at least one further stabilizer or costabilizer.

Radical scavenger with at least two glycine units i) are compounds therein which preferably have at least one amide and / or contain ester unit, particularly preferably free radical scavenger Formula (I). Stabilizer mixtures with the aforementioned preferred radical scavengers according to the invention Of course also subject of the invention.

There are combinations of all of the above mentioned components possible.

Stabilizers or costabilizers are the above oxygen-containing gases, phenolic compounds, quinones and Hydroquinones, N-oxyl compounds, aromatic amines and phenylenediamines, imines, Sulfonamides, oximes, hydroxylamines, urea derivatives, phosphorus-containing and / or sulfur-containing compounds, complexing agents based on TAA and / or metal salts.

Stabilizer mixtures are preferred from the radical scavenger and phenothiazine, radical scavenger / hydroquinone, Radical scavenger / hydroquinone, Free-radical scavengers / 4-hydroxy-2,2,6,6-tetramethyl-piperidine-N-oxyl, Free-radical scavengers / 4-oxo-2,2,6,6-tetramethyl-piperidine-N-oxyl, Free-radical scavengers / 2,2,6,6-tetramethyl-piperidine-N-oxyl, Radical scavengers / phenothiazine / hydroquinone, Free-radical scavengers / phenothiazine / 4-hydroxy-2,2,6,6-tetramethyl-piperidine-N-oxyl or radical scavenger / hydroquinone monomethyl ether / 4-hydroxy-2,2,6,6-tetramethyl-piperidine-N-oxyl and optionally at least one of the cerium salts mentioned, each in arrival or Absence of an oxygen-containing gas, preferably in the presence.

The stabilizer mixtures according to the invention contain components i) and ii) in weight ratios i): ii) between 1: 100 to 100: 1, preferably 1:50 to 50: 1, particularly preferably 1:10 to 10: 1 and in particular 1: 5 to 5: 1.

The invention further relates to Mixtures containing the aforementioned stabilizer mixtures according to the invention and contain at least one polymerizable compound. All combinations of stabilizer mixtures according to the invention are included with polymerizable Connections possible.

The use of the mixtures, which contain the aforementioned stabilizer mixtures, for stabilization polymerizable Compounds against polymerization during processing, storage and / or Transport is also the subject of the invention.

Compounds capable of polymerization in the sense of the present invention are those having at least one ethylenically unsaturated group. These are selected from mono-, di- or triethylenically unsaturated C ₃ -C ₈ carboxylic acids, C ₁ -C ₂₀ esters, amides, nitriles and anhydrides of these mono-, di- or triethylenically unsaturated C ₃ -C ₈ -Carboxylic acids, vinyl esters of up to 20 C-containing carboxylic acids, vinyl ethers of 1 to 10 C-containing alcohols, vinyl aromatics and - heteroaromatic with up to 20 C-atoms, vinyl lactams with 3 to 10 C-atoms in the ring, open-chain N -Vinylamide compounds and N-vinylamine compounds, vinyl halides, aliphatic optionally halogenated hydrocarbons with 2 to 8 carbon atoms and 1 or 2 double bonds, vinylidenes or mixtures of these monomers.

Preferred mono-, di- or triethylenically unsaturated C ₃ -C ₆ carboxylic acids are e.g. B. (meth) acrylic acid, dimethylacylic acid, ethacrylic acid, citraconic acid, methylene malonic acid, crotonic acid, fumaric acid, mesaconic acid, itaconic acid, maleic acid and their C ₁ -C ₂₀ alkyl esters, amides, nitriles, aldehydes and anhydrides such as, for. B. (meth) acrylic acid methyl ester, (meth) acrylic acid ethyl ester, (meth) acrylic acid n-butyl ester, (meth) acrylic acid n-propyl ester, (meth) acrylic acid isopropyl ester, (meth) acrylic acid 2-ethylhexyl ester, (meth ) acrylic acid aryl ester, maleic acid monomethyl ester, maleic acid dimethyl ester, maleic acid monoethyl ester, maleic acid diethyl ester, alkylene glycol (meth) acrylates, (meth) acrylamide, N-dimethyl (meth) acrylamide, N-tert-butyl (meth) acrylamide, (meth) acrylonitrile, (meth) acrolein , (Meth) acrylic anhydride, itaconic 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 latter monomers with carboxylic acids or mineral acids and the qauternated products.

Other monomers of this group are e.g. B. also hydroxyl-containing monomers, in particular C ₁ -C ₁₀ hydroxyalkyl (meth) acrylates such as hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, hydroxyisobutyl (meth) acrylate.

Other monomers in this group are Phenyloxyethyl glycol mono- (meth) acrylate, glycidyl (meth) acrylate, Trimethylolpropane triacrylate, ureidomethyl methacrylate, amino (meth) acrylates such as 2-aminoethyl (meth) acrylate.

With vinyl esters of carboxylic acids 1 to 20 carbon atoms are e.g. B. vinyl laurate, vinyl stearate, vinyl propionate, vinyl versatic acid and vinyl acetate.

As a vinyl ether of 1 to 10 carbon atoms Containing alcohols are e.g. B. methyl vinyl ether, ethyl vinyl ether, butyl vinyl ether, 4-hydroxybutyl vinyl ether, vinyl isobutyl ether or dodecyl vinyl ether to call.

As vinyl aromatic and heteroaromatic Compounds come, for example, vinyl toluene, α- and p-methylstyrene, α-butylstyrene, 4-n-butylstyrene, 4-n-decylstyrene, styrene, divinylbenzene, 2-vinylpryridine, N-vinylimidazole, N-vinylpiperidone, N-vinyl-2-methylimidazole and N-vinyl-4-methylimidazole into consideration.

Vinyl lactams with 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.

Open-chain N-vinylamide compounds can also be used and N-vinylamine compounds such as N-vinylformamide, N-vinyl-N-methylformamide, N-vinyl acetamide, N-vinyl-N-methylacetamide, N-vinyl-N-ethylacetamide, N-vinyl propionamide, N-vinyl-N-methyl propionamide and N-vinylbutyramide and N-vinyl-N-dimethylamine, N-vinyl-N-methylethylamine, N-vinyl-N-diethylamine stabilized by the process according to the invention become.

The vinyl halides are with chlorine, Fluorine or bromine substituted ethylenically unsaturated compounds such as Vinyl chloride, vinyl fluoride and vinylidene chloride.

Aliphatic halogenated if necessary Hydrocarbons with 2 to 8 carbon atoms and 1 or 2 olefinic Double bonds are, for example, ethylene, propene, 1-butene, 2-butene, isobutene, Called butadiene, isoprene and chloroprene.

For example, as vinylidene Called vinylidencyanid.

Other polymerizable compounds are N-vinylcaprolactam, vinyl phosphoric acids, vinyl acetic acid, allylacetic acid, N-vinyl carbazole, Hydroxymethyl vinyl ketone, N, N-divinylethylene urea, vinylene carbonate, Tetrafluoroethylene, hexafluoropropene, nitroethylene, allylacetic acid, α-chloroacrylic ester, α-cyanoacrylic ester, methylene malonic ester, α-cyano sorbic acid ester, Cyclopentadiene, cyclopentene, cyclohexene and cyclododecene.

In a preferred embodiment of the process according to the invention, the radical scavengers are used to stabilize 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-vinyl pyrrolidone, vinyl phosphoric acids, N-vinyl carbazole, N, N-divinylethylene urea, trimethylol propane acrylate, ureidomethyl methacrylate, styrene, butadiene or isoprene.

Preferred unsaturated C ₃ -C ₈ carboxylic acids are for example acrylic acid and methacrylic acid and their C ₁ -C ₈ alkyl esters such as. B. methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate.

In a preferred embodiment, the radical scavengers according to the invention are in a ver used to drive like it in DE-A 100 64 642 is described. For this purpose, in a process for working up (meth) acrylic acid in the presence of at least one stabilizer, a mixture of substances originating from the working up and essentially free of (meth) acrylic acid and containing stabilizer is passed into a distillation apparatus and a low-boiling stream containing stabilizer obtained therefrom is fed into the Workup returned.

For Such a method is particularly radical scavengers according to the invention suitable whose vapor pressures at 141 ° C (Boiling point of acrylic acid) at normal pressure be at least 15 hPa, preferably between 20 and 800 hPa, particularly preferably between 25 and 500 hPa, very particularly preferably between 25 and 250 hPa and in particular between 25 and 160 hPa and their mixtures.

In a further preferred embodiment are the radical scavengers according to the invention in a process for working up N-vinyl monomers such as those mentioned Vinyl esters, vinyl ethers, vinyl aromatics and heteroaromatics and the open-chain V-vinylamide compounds and N-vinylamine compounds used.

Of course, the area of application relates of the method according to the invention also on storage and transport of these polymerizable compounds.

Ppm- used in this document and percentages relate to unless otherwise stated Weight percent and ppm.

The following examples are intended to Explain invention, but don't limit yourself to these examples.

example 1

0.5 ml freshly thawed and for Removal of the storage stabilizer was double distilled acrylic acid in an air atmosphere filled into 1.8 ml ampoules.

The samples were all in the forced air drying cabinet at 120 ° C stored.

In each series of tests, everyone Acrylic acid sample 3 ampoules each filled and tested, the mean of the time to complete polymerization was captured visually.

The average standard deviation within a test series was approx. 2-4%.

The concentrations were so far not otherwise specified, 25 ppm radical scavenger plus 10 ppm phenothiazine (PTZ).

The relative effectiveness is calculated is the quotient from the time until the sample polymerizes from radical scavenger and PTZ and the time until the reference sample polymerized. As Pure PTZ was used as the reference sample, the relative effectiveness of the reference sample therefore 1.0.

The results are in Table 3 summarized.

Table 3

Example 2

In a 250 ml round bottom flask 90 ml of the monomer with the desired one Amount of stabilizer filled and rinsed with the appropriate atmosphere. The piston was on the desired Storage temperature heated. Samples were taken at regular intervals. This were examined for the polymer content by Raman spectroscopy. The The course of the curve relative to the unstabilized sample shows the effectiveness of the stabilizer system used.

A mixture of N-vinylpyrrolidone (NVP) and pyrrolidone (1: 1) are used and with 25 ppm PTZ offset. The sample was examined at 150 ° C under an air atmosphere. Rapid polymer formation (PVP = polyvinylpyrrolidone) took place. The results are shown in Table 4.

A mixture of 25 ppm radical scavenger (Table 3 from Example 1) and 25 ppm PTZ was added to a mixture of N-vinylpyrrolidone and pyrrolidone (1: 1) and heated under identical conditions. No significant differences could be determined between the free radical scavengers used in Example 1. Table 5 summarizes the results of a radical scavenger (Table 3 from Example 1, 1st entry). The formation of PVP in the presence of a radical scavenger according to the invention and PTZ was successfully suppressed.

Then, using this example the influence of different concentrations of PTZ and radical scavenger according to the invention was investigated. The results are shown in Table 6. From this it becomes clear that from an amount of 25 ppm PTZ and free radical scavenger none significant difference in the polymerization inhibition recognizable is.

Claims (23)

Process for stabilizing polymerizable compounds against polymerization during processing, storage and / or transport, characterized in that at least one radical scavenger, the contains at least two glycine units, with the proviso that the radical scavenger not selected is from ethylenediaminetetraacetic acid (EDTA), diethylenetriaminepentaacetic acid (DTPA), trans-1,2-cyclohexanediaminetetraacetic acid (CYDTA) and their alkali and alkaline earth salts. A method according to claim 1, characterized in that at least one radical scavenger containing at least two glycine units is used, with the proviso that the radical scavenger does not have ≥ 2 of the following structural units:

wherein R, R 'can independently be hydrogen or metal. A method according to claim 1 or 2, characterized in that that you have at least one radical scavenger that has at least 2 glycine units and contains at least one amide and / or ester unit. Process according to claims 1 to 3, characterized in that at least one radical scavenger of the formula (I) is used

wherein, G ^{1 can be} NR ³ R ⁴ or OR ⁷ , G ² NR ⁵ R ⁶ or OR ⁸ can be, R ¹ to R ⁶ independently of one another hydrogen, C ₁ -C ₂₀ alkyl, C ₁ -C ₂₀ alkylcarbonyl, 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 ₅ -C ₁₅ cycloalkylcarbonyl, aryl, arylcarbonyl or can be heterocycles, R ⁷ and R ⁸ independently of one another are C ₁ -C ₂₀ alkyl, C ₁ -C ₂₀ alkylcarbonyl, C ₂ -C ₂₀ alkenyl, C ₂ -C ₂₀ alkenylcarbonyl, C ₂ -C ₂₀ - Can be alkynyl, C ₂ -C ₂₀ alkynylcarbonyl, C ₃ -C ₁₅ cycloalkyl, C ₅ -C ₁₅ cycloalkylcarbonyl, aryl, arylcarbonyl or heterocycles, XC ₁ -C ₂₀ alkyl, NCH ₂ COOR ⁹ , NR ¹⁰ , Can be O, S, PR ¹¹ , Se, SiOR ¹² R ¹³ or aryl, wherein R ⁹ to R ^{13 can} independently be hydrogen or C ₁ -C ₂₀ alkyl, and k, l, m, n independently of one another for numbers can stand from 0 to 20. Process according to claims 1 to 4, characterized in that R ¹ and R ^{2 are the} same and are hydrogen or C ₁ -C ₂₀ alkyl. Process according to claims 1 to 5, characterized in that R ³ and R ^{5 are the} same and are hydrogen, C ₁ -C ₂₀ alkyl or C ₁ -C ₂₀ alkylcarbonyl. Process according to claims 1 to 6, characterized in that R ⁴ and R ^{6 are the} same and C ₁ -C ₂₀ alkyl, C ₁ -C ₂₀ alkylcarbonyl, aryl, C ₂ -C ₂₀ alkenyl, C ₂ -C ₂₀ -Alkenylcarbonyl, C ₂ -C ₂₀ alkynyl or C ₂ -C ₂₀ alkynylcarbonyl. Process according to claims 6 or 7, characterized in that R ³ and R ^{5 are} hydrogen and R ⁴ and R ^{6 are} selected from phenyl, benzyl, p-methoxyphenyl, o-, m- or p-hydroxyphenyl, 1-hydroxyhexyl, methyl , Ethyl, propyl, butyl, ethylene glycol, diethylene glycol, triethylene glycol, ethoxylate with 4 to 10 EO units, ethylenediamine, diethylenetriamine, triethylenetetraamine and amino acids. Process according to claims 1 to 5, characterized in that R ⁷ and R ^{8 are the} same and C ₁ -C ₂₀ alkyl, C ₁ -C ₂₀ alkylcarbonyl, aryl, C ₂ -C ₂₀ alkenyl, C ₂ -C ₂₀ -Alkenylcarbonyl, C ₂ -C ₂₀ alkynyl or C ₂ -C ₂₀ alkynylcarbonyl. A method according to claim 9, characterized in that R ⁷ and R ^{8 are} selected from phenyl, benzyl, p-methoxyphenyl, o-, m- or p-hydroxyphenyl, 1-hydroxyhexyl, methyl, ethyl, propyl, butyl, ethylene glycol, diethylene glycol , Triethylene glycol, ethoxylate with 4 to 10 EO units, ethylenediamine, diethylenetriamine, triethylenetetraamine and amino acids. Process according to claims 1 to 10, characterized in that XC ₁ -C ₂₀ alkyl or GH ₂ NCOOR ⁹ . Process according to claims 1 to 11, characterized in that at least one of the following compounds is used:

Method according to claims 1 to 12, characterized in that that you 0.1 to 1000 ppm of the radical scavenger or a radical scavenger mixture based on the polymerizable Connection starts. Method according to claims 1 to 13, characterized in that you use at least one costabilizer. A method according to claim 14, characterized in that the costabilizer selected is 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 tetraazannules and metal salts, and if appropriate Mixtures of these. A method according to claim 14 or 15, characterized in that that as 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 of it begins. Method according to one of the preceding claims, characterized characterized in that the polymerizable compound at least an ethylenically unsaturated Group contains. A method according to claim 17, characterized in that the polymerizable compound is selected from the group of mono-, di- or triethylenically unsaturated C ₃ -C ₈ carboxylic acids, C ₁ -C ₂₀ esters, amides, nitriles and anhydrides of these mono-, di- or triethylenically unsaturated C ₃ -C ₈ carboxylic acids, vinyl esters of carboxylic acids containing up to 20 C atoms, vinyl ethers of alcohols containing 1 to 10 C atoms, vinyl aromatics and - heteroaromatics with up to 20 C atoms, Vinyl lactams with 3 to 10 carbon atoms in the ring, open-chain N-vinylamide compounds and N-vinylamine compounds, vinyl halides, aliphatic optionally halogenated hydrocarbons with 2 to 8 carbon atoms and 1 or 2 double bonds, vinylidenes or mixtures of these monomers. Process according to claim 17 or 18, characterized in that the polymerizable compound is mono-, di- or triethylenically unsaturated C ₃ -C ₈ -carboxylic acids, C ₁ -C ₂₀ esters of these mono-, di- or triethylenically unsaturated C ₃ - C ₈ carboxylic acids, vinyl esters of carboxylic acids containing up to 20 C atoms, vinyl ethers of alcohols containing 1 to 10 C atoms, vinyl aromatics and heteroaromatics with up to 20 C atoms, vinyl lactams with 3 to 10 C atoms in the ring, uses open-chain N-vinylamide compounds or N-vinylamine compounds. Process according to claims 17 to 19, characterized in that the polymerizable compound is (meth) acrylic acid, (meth) acrylic acid ester, N-vinylcaprolactam, N-vinylformamide, N-vinylimi dazol, N-vinylpyrrolidone, vinylphosphoric acids, N-vinylcarbazole, N, N-divinylethyleneurea, trimethylolpropane triacrylate, ureidomethyl methacrylate, styrene, butadiene or isoprene. Containing stabilizer mixture i) at least a radical scavenger, which contains at least two glycine units, with the proviso that the radical scavenger not selected is from ethylenediaminetetraacetic acid (EDTA), diethylenetriaminepentaacetic acid (DTPA), trans-1,2-cyclohexanediaminetetraacetic acid (CYDTA) and their alkali and alkaline earth salts and ii) at least one another stabilizer or co-stabilizer. Mixture of substances containing a stabilizer mixture according to claim 21 and at least one polymerizable compound. Use of a stabilizer mixture according to claim 21 for stabilizing polymerizable compounds against polymerization during processing, storage and / or transport.