DE10243241A1 - A process for separation of alpha, beta-unsaturated carboxylic acids from a reaction mixture by reaction with 2-oxazoline and radiation curing with a decreased content of residual alpha, beta-unsaturated carboxylic acids - Google Patents

Abstract

A process for separation of alpha, beta-unsaturated carboxylic acids from a reaction mixture by reaction of the alpha,beta-unsaturated carboxylic acids with at least one 2-oxazoline , where the content of alpha, beta-unsaturated carboxylic acids in the reaction mixture prior to reaction with the 2-oxazoline does not exceed 20 wt.% is new. Independent claims are included for: (1) a radiation curable composition containing the reaction mixture in which the alpha, beta-unsaturated carboxylic acids are reacted with the 2-oxazoline; (2) a polymer obtainable by reaction of at least one alpha, beta-unsaturated carboxylic acid with at least one 2-oxazoline and at least one epoxy compound; a radiation curable composition containing polymer; (3) a process for coating of substrates using the radiation cured composition.

Description

Find radiation curable compositions increasingly used for coating substrates. such Compositions often contain Esters of acrylic acid or methacrylic acid, summarized in this document as (meth) acrylic acid.

The in the manufacture of such (meth) acrylates The resulting reaction mixtures usually contain (meth) acrylic acid in quantities from 0.01 to 20% by weight and typically fall at catalytic esterification of mono- or polyhydric alcohols with a surplus (Meth) acrylic acid on. The removal of the excess (meth) acrylic acid is due to toxicological, production and product engineering perspective vital. For the use as a paint raw material is usually a residual content regarding acrylic acid with an acid number (SZ) below 5 mg KOH / g required (corresponds to a content of approx. 0.64% by weight acrylic acid). Technically, this is done, for example, by an alkaline wash or by the addition of acrylic acid scavengers, such as e.g. Epoxies.

The alkaline washout of acrylic acid is disadvantageous from an economic point of view, since this involves large quantities of acrylic acid withdrawn unused from the product. In addition, water-soluble products and additives with washed out again after washing must be added.

The use of epoxies is in the production of radiation-curable Paint raw materials suitable because the reaction products of acrylic acid and Epoxides, in turn, produce reactive acrylic esters, which are mostly problem-free react as part of the paint system.

The disadvantage of this, however, is that Epoxides, e.g. Bisphenol A diglycidether, expensive and mostly aromatic, thus can lead to yellowing of the product. Aliphatic epoxies are generally less yellowing, but significantly more expensive Feedstocks as the aromatic. The implementation continues with these Epoxides by building up polymers with high molecular weight in usually an undesirable strong viscosity increase of the reaction mixture. Furthermore, it is mostly used for reaction with epoxides a catalyst is required, for example tetraalkylammonium halides.

WO 98/33855 and EP-A1 970 977 describe reaction products of 2-oxazolines with acrylic acid as polymers which contain amidoacrylate structures.

The implementation is in the literature of 2-oxazolines with acrylic acid already described in detail at low temperatures. So reacted 2-methyl-2-oxazoline already at 40 ° C in DMF with acrylic acid or with β-propiolactone to the same product, forming N-acylethyleneimine units (G. Odian, P.A. Gunatillake, Macromolecules 1984, 17, 1297-1307 and T. Saegusa, S. Kobayashi, Y. Kimura, Macromolecules 1974, 7, 139-140).

As electrophilic nucleophiles can also Acrylamide, hydroxyalkyl acrylates, maleimides and cyclic carboxylic anhydrides can be used (T. Saegusa, H. Ikeda, H. Fujii, Macromolecules 1972, 5, 354-8 and Macromolecules 1975, 8, 374-6).

The strictly alternating so available Polymers based on 2-ethyl-2-oxazoline and acrylic acid known (CA No. 127273-81-8).

In the writings mentioned, the Reaction in each case for the production of the polymer in question from acrylic acid and 2-oxazoline with a molecular weight of approx. 140 to 2500 (WO 98/33855) or 590-2760 (G. Odian, P.A. Gunatillake, loc.cit.). To do this acrylic acid and the 2-oxazoline are reacted with one another in pure form. The yields achieved in spite of a variety of varied Reaction parameters at the reaction conditions not more than 69 % (G. Odian, P.A. Gunatillake, loc.cit.) Or 75% (WO 98/33855).

Object of the present invention was to find an alternative method of separating α, β-unsaturated carboxylic acids to develop from reaction mixtures in which the residual content of α, β-unsaturated carboxylic acid is reduced and the reaction product can remain in the paint raw material without the application properties of the finished radiation-curable Adversely affect paint system. The Reaction products should continue to have low viscosities End products.

The task was solved by a process for the separation of α, β-unsaturated Carboxylic acids these containing reaction mixtures by reacting the α, β-unsaturated carboxylic acids with at least one 2-oxazoline, the content of α, β-unsaturated carboxylic acid no longer in the reaction mixture before the reaction with the 2-oxazoline than 20% by weight.

With the process according to the invention it is possible to reduce the content of α, β-unsaturated carboxylic acid in the reaction mixture to below 1% by weight. In view of the maximum yield of 75% in the prior art, it must therefore be described as surprising and unexpected that the α, β-unsaturated carboxylic acid content can be reduced so efficiently by the process according to the invention without side reactions with electrophilic initiators, such as, for example, occurring ring-opening polymerizations to form poly- (N-acylethyleneimines), as are known from Encyclopedia of Polymer Science and Technology, Suppl. Vol. 1, 1976, pp. 220-237. In addition, the polymeric adducts can have a positive effect on the oxygen affect the sensitivity of the uncured paint, so that curing is usually possible under an oxygen-containing atmosphere. This effect has hitherto been achieved by carrying out Michael additions of amine compounds which contain alpha-methylene groups and which are accordingly oxygen-sensitive, ie oxidizable.

a, b-Unsaturated carboxylic acids can, for example, according to the invention be acrylic acid, methacrylic acid, ethacrylic, hydroxymethylacrylic, maleic including their anhydride and half esters, fumaric acid, itaconic acid, citraconic acid, mesaconic acid or crotonic, preferably acrylic acid, methacrylic acid, maleic anhydride and maleic acid, particularly preferred (meth) acrylic acid and most preferably acrylic acid.

Reaction mixtures in the sense of this Font are mixtures that are available are by reactions of at least one α, β-unsaturated carboxylic acid at least one reactant with the aim of chemically the α, β-unsaturated carboxylic acid to change. You can for example, reactions of at least one α, β-unsaturated carboxylic acid with Hydroxy group-containing compounds (esterification), implementation of at least one α, β-unsaturated carboxylic acid with alkylene oxides, such as ethylene oxide, propylene oxide, iso-butylene oxide, 1-butene oxide, 2-butene oxide, vinyl oxirane, styrene oxide or epichlorohydrin, or glycidyl ethers, for example aromatic Glycidyl ethers or aliphatic glycidyl ethers or reactions of at least one α, β-unsaturated carboxylic acid with compounds containing amino groups, preferred reaction mixtures are esterification mixtures.

Preferred esterification mixtures are those reaction mixtures which are obtainable by esterification at least one α, β-unsaturated carboxylic acids with at least one compound that has at least one hydroxy group contains preferably 2 to 10, particularly preferably 2 to 6, very particularly preferably 2 to 4 and in particular 2 to 3.

Connections that are at least two Hydroxy groups are included in this document as polyalcohols designated.

The polyalcohols can be aliphatic, be cycloaliphatic or aromatic, preferably aliphatic or cycloaliphatic and very particularly preferably aliphatic, straight-chain or branched and optionally substituted with functional ones Groups.

As a rule, the polyalcohols two to 50 carbon atoms and preferably three to 40.

The molecular weight of the polyalcohols that can be used is usually below 5000 g / mol, preferably below 2500 g / mol, particularly preferably below 1500 g / mol, very particularly preferably below 1000 g / mol and in particular below 800 g / mol.

Preferred polyalcohols are polyols, functionalized polyols, alkoxylated polyols, sugar alcohols, alkoxylated Sugar alcohols, polyesherols, polyesterols and at least partially alkoxylated polyesterols.

Examples of polyols are trimethylol butane, Trimethylolpropane, trimethylolethane, neopentyl glycol, hydroxypivalic acid neopentyl glycol ester, Pentaerythritol, glycerin, 1,2-ethylene glycol, 1,2-propylene glycol, 2-ethyl-1,3-propanediol, 2-methyl-1,3-propanediol, hydroquinone, bisphenol A, bisphenol F, Bisphenol B, 2,2-bis (4-hydroxycyclohexyl) propane, 1,1-, 1,2-, 1,3- and 1,4-cyclohexanedimethanol, 1,2-, 1,3- or 1,4-cyclohexanediol, But-2-en-1,4-diol and but-2-in-1,4-diol.

The polyols can also carry additional functionalities such as ether functions (-O-), carboxyl functions (-COOH) or C ₁ -C ₄ alkyloxycarbonyl functions (ester groups), C ₁ -C ₄ alkyl in this document being methyl, ethyl, iso Propyl, n-propyl, n-butyl, iso-butyl, sec-butyl or tert-butyl.

Examples of such functionalized polyols are ditrimethylolpropane, dipentaerythritol, dimethylolpropionic acid, dimethylolbutyric acid, trimethylolacetic acid, hydroxypivalic acid and the 2-hydroxyethyl or C ₁ -C ₄ alkyl esters of these acids.

Examples of sugar alcohols are sorbitol, Mannitol, maltitol, isomalt, diglycerol, threitol, erythritol, adonite (ribitol), Arabite (Lyxit), Xylit and Dulcit (Galactit).

Examples of polyetherols are poly-THF with a molecular weight between 162 and 2000, preferably between 162 and 1458, particularly preferably between 162 and 1098, very particularly preferably between 162 and 738 and in particular between 162 and 378, poly-1,3-propanediol and poly-1,2-propanediol with a molecular weight between 134 and 1178, preferably between 134 and 888, particularly preferably between 134 and 598 and very particularly preferably between 134 and 308, polyethylene glycol with a molecular weight between 106 and 898, preferably between 106 and 458, particularly preferably from 106 to 400, very particularly preferably between 106 and 235 and in particular Diethylene glycol, triethylene glycol and tetraethylene glycol.

As polyesterols e.g. such considered, as by esterification of polycarboxylic acids, preferably dicarboxylic acids, can be produced with the above polyols.

The starting materials for such polyesterols are known to the person skilled in the art. Preferably can be used as polycarboxylic acids, oxalic acid, maleic acid, fumaric acid, succinic acid, glutaric acid, adipic acid, sebacic acid, dodecanedioic acid, o-phthalic acid, isophthalic acid, terephthalic acid, trimellitic acid, azelaic acid, 1,4-cyclohexanedicarboxylic acid or tetrahydrophthalic acid, their isomers and hydrogenation products, and esterifiable derivatives, such as anhydrides or dialkyl esters, for example C ₁ -C ₄ alkyl esters, preferably methyl, ethyl or n-Butyl ester, the acids mentioned are used.

As carboxylic acids or hydroxyl groups Lactones come 4-hydroxybenzoic acid, 6-hydroxy-2-naphthoic acid, Pivalolactone or ε-caprolactone into consideration. The above-mentioned polyfunctional ones come as polyols Alcohols, preferably neopentyl glycol, trimethylolpropane, trimethylolethane, Pentaerythritol, dimethylolpropionic acid or dimethylolbutyric acid.

Can also be used as polyalcohols are alkoxylated polyols and alkoxylated polyesterols obtained by reaction a polyol or polyesterol with at least one alkylene oxide available are.

These are the products the available if one or more of the polyols or polyesterols listed above with at least one alkylene oxide, for example ethylene oxide, propylene oxide, iso-butylene oxide, 1-butene oxide, 2-butene oxide, vinyl oxirane, styrene oxide or epichlorohydrin. A degree of alkoxylation is preferred per hydroxy group from 1 to 30, particularly preferably from 1 to 20, very particularly preferably 1 to 10 and in particular 1 to 5.

The content of α, β-unsaturated carboxylic acids in Reaction mixture is not more than 20% by weight, preferably not more than 15, especially preferably from 0.5 to 10, very particularly preferably from 1 to 7 and in particular from 2 to 6% by weight.

The free α, β-unsaturated carboxylic acids in Reaction mixture before conversion with the 2-oxazoline are through the implementation of the invention reacted with the 2-oxazoline generally at least 80%, preferred at least 85%, particularly preferably at least 90%, entirely particularly preferably at least 93% and in particular at least 95%.

worin
R¹, R², R³, R⁴ und R⁵ unabhängig voneinander jeweils Wasserstoff, C₁-C₁₈-Alkyl, gegebenenfalls durch ein oder mehrere Sauerstoff- und/oder Schwefelatome und/oder ein oder mehrere substituierte oder unsubstituierte Iminogruppen unterbrochenes C₂-C₁₈-Alkyl, C₆-C₁₂-Aryl, C₅-C₁₂-Cycloalkyl oder einen fünf- bis sechsgliedrigen, Sauerstoff-, Stickstoff- und/oder Schwefelatome aufweisenden Heterocyclus bedeuten oder zwei von ihnen gemeinsam einen ungesättigten, gesättigten oder aromatischen und gegebenenfalls durch ein oder mehrere Sauerstoff- und/oder Schwefelatome und/ oder ein oder mehrere substituierte oder unsubstituierte Iminogruppen unterbrochenen Ring bilden, wobei die genannten Reste jeweils durch funktionelle Gruppen, Aryl, Alkyl, Aryloxy, Alkyloxy, Halogen, Heteroatome und/oder Heterocyclen substituiert sein können bedeuten.The content of α, β-unsaturated carboxylic acids in the reaction mixture after the reaction according to the invention with the 2-oxazoline is generally not more than 15% by weight, preferably not more than 10, particularly preferably not more than 5, very particularly preferably not more than 1 and in particular not more than 0.5% by weight. 2-Oxazolines (4,5-dihydrooxazoles) which can be used according to the invention can be, for example, those of the formula (I)

wherein
R ¹ , R ² , R ³ , R ⁴ and R ⁵ each independently of one another are hydrogen, C ₁ -C ₁₈ -alkyl, C optionally interrupted by one or more oxygen and / or sulfur atoms and / or one or more substituted or unsubstituted imino groups ₂ -C ₁₈ alkyl, C ₆ -C ₁₂ aryl, C ₅ -C ₁₂ cycloalkyl or a five- to six-membered, oxygen, nitrogen and / or sulfur atom-containing heterocycle or two of them together represent an unsaturated, saturated or aromatic ring which is optionally interrupted by one or more oxygen and / or sulfur atoms and / or one or more substituted or unsubstituted imino groups, the radicals mentioned being each by functional groups, aryl, alkyl, aryloxy, alkyloxy, halogen, heteroatoms and / or heterocycles can be substituted.

Mean in it
C ₁ -C ₁₈ alkyl optionally substituted by functional groups, aryl, alkyl, aryloxy, alkyloxy, halogen, heteroatoms and / or heterocycles, for example methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, Pentyl, hexyl, heptyl, octyl, 2-ethylhexyl, 2,4,4-trimethylpentyl, decyl, dodecyl, tetradecyl, hetadecyl, octadecyl, 1,1-dimethylpropyl, 1,1-dimethylbutyl, 1,1,3,3- Tetramethylbutyl, benzyl, 1-phenylethyl, 2-phenylethyl, α, α-dimethylbenzyl, benzhydryl, p-tolylmethyl, 1- (p-butylphenyl) -ethyl, p-chlorobenzyl, 2,4-dichlorobenzyl, p-methoxybenzyl, m- Ethoxybenzyl, 2-cyanoethyl, 2-cyanopropyl, 2-methoxycarbonethyl, 2-ethoxycarbonylethyl, 2-butoxycarbonylpropyl, 1,2-di- (methoxycarbonyl) -ethyl, 2-methoxyethyl, 2-ethoxyethyl, 2-butoxyethyl, diethoxymethyl, diethoxyethyl, 1,3-dioxolan-2-yl, 1,3-dioxan-2-yl, 2-methyl-1,3-dioxolan-2-yl, 4-methyl-1,3-dioxolan-2-yl, 2- Isopropoxyethyl, 2-butoxypropyl, 2-octyloxyethyl, chloromethyl, 2-chloroethyl, trichloromethyl, trifluoromethyl, 1,1-dimethyl-2-chloroethyl, 2-methoxyisopropyl, 2-ethoxyethyl, butylthiomethyl, 2-dodecylthioethyl, 2-phenylthioethyl, 2,2,2-trifluoroethyl, 2-hydroxyethyl, 2-hydroxypropyl, 3-hydroxypropyl, 4- Hydroxybutyl, 6-hydroxyhexyl, 2-aminoethyl, 2-aminopropyl, 3-aminopropyl, 4-aminobutyl, 6-aminohexyl, 2-methylaminoethyl, 2-methylaminopropyl, 3-methylaminopropyl, 4-methylaminobutyl, 6-methylaminohexyl, 2-dimethylaminoethyl, 2-dimethylaminopropyl, 3-dimethylaminopropyl, 4-dimethylaminobutyl, 6-dimethylaminohexyl, 2-hydroxy-2,2-dimethylethyl, 2-phenoxyethyl, 2-phenoxypropyl, 3-phenoxypropyl, 4-phenoxybutyl, 6-phenoxyhexyl, 2-methoxyethyl, 2-methoxypropyl, 3-methoxypropyl, 4-methoxybutyl, 6-methoxyhexyl, 2-ethoxyethyl, 2-ethoxypropyl, 3-ethoxypropyl, 4-ethoxybutyl or 6-ethoxyhexyl and,
C ₂ -C ₁₈ alkyl optionally interrupted by one or more oxygen and / or sulfur atoms and / or one or more substituted or unsubstituted imino groups, for example 5-hydroxy-3-oxapentyl, 8-hydroxy-3,6-dioxa- octyl, 11-hydroxy-3,6,9-trioxa-undecyl, 7-hydroxy-4-oxa-heptyl, 11-hydroxy-4,8-dioxa-undecyl, 15-hydroxy-4,8,12-trioxa- pentadecyl, 9-hydroxy-5-oxa-nonyl, 14-hydroxy-5,10-oxa-tetradecyl, 5-methoxy-3-oxa-pentyl, 8-methoxy-3,6-dioxa-octyl, 11-methoxy- 3,6,9-trioxa-undecyl, 7-methoxy-4-oxa-heptyl, 11-methoxy-4,8-dioxa-undecyl, 15-methoxy-4,8,12-trioxa-pentadecyl, 9-methoxy- 5-oxa-nonyl, 14-meth oxy-5,10-oxa-tetradecyl, 5-ethoxy-3-oxa-pentyl, 8-ethoxy-3,6-dioxa-octyl, 11-ethoxy-3,6,9 -trioxa-undecyl, 7-ethoxy-4-oxaheptyl, 11-ethoxy-4,8-dioxa-undecyl, 15-ethoxy-4,8,12-trioxa-pentadecyl, 9-ethoxy-5-oxa-nonyl or 14 ethoxy-5,10-oxa-tetradecyl.

If two radicals form a ring, these radicals can jointly mean 1,3-propylene, 1,4-butylene, 2-oxa-1,3-propylene, 1-oxa-1,3-propylene, 2-oxa-1, 3-propylene, 1-oxa-1,3-propenylene, 1-aza-1,3-propenylene, 1- (C ₁ -C ₄ alkyl) -1-aza-1,3-propenylene, 1,4- Buta-1,3-dienylene, 1-aza-1,4-buta-1,3-dienylene or 2-aza-1,4-buta-1,3-dienylene.

The number of oxygen and / or Sulfur atoms and / or imino groups are not limited. In the Rule is they not more than 5 in the rest, preferably not more than 4 and very particularly preferably not more than 3.

Furthermore are between two heteroatoms, as a rule, preferably at least one carbon atom at least two.

Substituted and unsubstituted Imino groups can for example imino, methylimino, iso-propylimino, n-butylimino or be tert-butylimino.

Continue to mean
functional groups carboxy, carboxamide, hydroxy, di (C ₁ -C ₄ alkyl) amino, C ₁ -C ₄ alkyloxycarbonyl, cyano or C ₁ -C ₄ alkyloxy, optionally by functional groups, aryl, alkyl, aryloxy , Alkyloxy, halogen, heteroatoms and / or heterocycles substituted C ₆ -C ₁₂ aryl, for example phenyl, tolyl, xylyl, α-naphthyl, β-naphthyl, 4-diphenylyl, chlorophenyl, dichlorophenyl, trichlorophenyl, difluorophenyl, methylphenyl, dimethylphenyl, trimethylphenyl , Ethylphenyl, diethylphenyl, iso-propylphenyl, tert-butylphenyl, dodecylphenyl, methoxyphenyl, dimethoxyphenyl, ethoxyphenyl, hexyloxyphenyl, methylnaphthyl, isopropylnaphthyl, chloronaphthyl, ethoxynaphthyl, 2,6-dimethylphenyl, 2,4,6-trimethylphenyl Dimethoxyphenyl, 2,6-dichlorophenyl, 4-bromophenyl, 2- or 4-nitrophenyl, 2,4- or 2,6-dinitrophenyl, 4-dimethylaminophenyl, 4-acetylphenyl, methoxyethylphenyl or ethoxymethylphenyl,
C ₅ -C ₁₂ cycloalkyl optionally substituted by functional groups, aryl, alkyl, aryloxy, alkyloxy, halogen, heteroatoms and / or heterocycles, for example cyclopentyl, cyclohexyl, cyclooctyl, cyclododecyl, methylcyclopentyl, dimethylcyclopentyl, methylcyclohexyl, dimethylcyclohexyl, butylcycloxyhexohexyl, methylcyclohexohexyl , Dimethoxycyclohexyl, Diethoxycyclohexyl, Butylthiocyclohexyl, Chlorcyclohexyl, Dichlorcyclohexyl, Dichlorcyclopentyl as well as a saturated or unsaturated bicyclic system such as Norbornyl or Norbornenyl and
a five- to six-membered heterocycle containing oxygen, nitrogen and / or sulfur atoms, for example furyl, thiophenyl, pyrryl, pyridyl, indolyl, benzoxazolyl, dioxolyl, dioxyl, benzimidazolyl, benzthiazolyl, dimethylpyridyl, methylquinolyl, dimoxypyridyl, dimethylpyridyl, dimethylpyrylyl, Methylthiophenyl, isopropylthiophenyl or tert-butylthiophenyl.

R ¹ is preferably hydrogen, methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, n-pentyl, 1-ethylpentyl, nonyl, undecyl, phenyl, 4-methylphenyl, 4-methoxyphenyl , 4-chlorophenyl, 2,6-dimethylphenyl, 2,6-dimethoxyphenyl, 2,4,6-trimethylphenyl and 2-furanyl.

R ¹ is particularly preferably hydrogen, methyl, ethyl or phenyl, very particularly preferably hydrogen, methyl or ethyl and in particular ethyl.

At least two of the radicals R ² , R ³ , R ⁴ and R ⁵ are preferably hydrogen and the remaining methyl, vinyl and / or phenyl, particularly preferably at least three of the radicals R ² , R ³ , R ⁴ and R ^{5 are} hydrogen and the remaining methyl, very particularly preferably either R ² or R ^{4 are} methyl or hydrogen and the other of the radicals R ¹ to R ^{4 are} hydrogen and in particular R ² , R ³ , R ⁴ and R ^{5 are} hydrogen.

The following 2-oxazolines are particularly preferred:
2-ethyl-2-oxazoline, 2-methyl-2-oxazoline, 2-oxazoline, 2,4,4-trimethyl-2-oxazoline, 4,4-dimethyl-2-oxazoline and 2-ethyl-4,4- dimethyl-2-oxazoline, especially 2-ethyl-2-oxazoline.

Of course, one or more 2-oxazolines are used, for example 1 to 4, preferably 1 to 3, particularly preferably 1 to 2 and very particularly preferably 1.

The reaction according to the invention of the α, β-unsaturated carboxylic acid contained in the reaction mixture can take place, for example, under the following reaction conditions:
The temperature of the reaction can be 25 to 120 ° C, preferably 40 to 100 and particularly preferably 40 to 80 ° C.

The molar ratio of 2-oxazoline to im Reaction mixture contained α, β-unsaturated carboxylic acid is usually more than 1, preferably 1.0 to 1.5 and particularly preferred 1.1 to 1.3 mol / mol.

The oxazoline is added preferably liquid, i.e. with a liquid Oxazoline in substance or in solution and in the case of a solid oxazoline as a melt, solution or dispersion.

Implementation of the reaction mixture with the oxazoline usually takes no more than 6 hours, preferably 0.5 to 5 and particularly preferably 1 to 4 hours.

The addition of a catalyst is usually not necessary since the implementation of the oxazoline with the α, β-unsaturated carboxylic acid is autocatalyzed.

The implementation can be carried out discontinuously, be carried out continuously or semi-continuously, preferably under Mixing, for example stirring or pumping around.

This is usually done with oxazoline metered into the reaction mixture and reacted as described above, however, the order is not essential according to the invention.

Another subject of the present Invention are radiation curable Compositions comprising at least one reaction mixture prepared according to the invention included in the contained therein α, β-unsaturated carboxylic acids at least one 2-oxazoline have been reacted.

It can be advantageous to treat the reaction mixtures obtainable according to the invention after or during the reaction with the 2-oxazoline with a compound having primary or secondary amino groups, as is known, for example, from EP-A-280 222 . DE-A-23 46 424 and the EP-A-211 978 is known.

In a preferred embodiment becomes the α, β-unsaturated carboxylic acid containing Reaction mixture according to the invention with a Oxazoline and additionally reacted with at least one alkylene oxide or glycidyl ether. This has the advantage that it consists of α, β-unsaturated carboxylic acid and oxazoline built polymer by reaction with the epoxy or Glycidyl ether is terminated and thus built up lower molecular weights become, which leads to a reduced viscosity increase. It will also be less Amount of epoxy or glycidyl ether needed.

For this, the reaction mixture is like implemented above with the oxazoline and additionally with implemented at least one epoxy compound.

A suitable epoxy compound is one with at least one epoxy group, for example an alkylene oxide or a glycidyl ether. Examples of alkylene oxides are ethylene oxide, Propylene oxide, isobutylene oxide, 1-butene oxide, 2-butene oxide, vinyl oxirane, styrene oxide or epichlorohydrin. glycidyl can for example aromatic or aliphatic. Examples of aromatic are bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, bisphenol B diglycidyl ether, Bisphenol-S-diglycidyl ether, hydroquinone diglycidyl ether, alkylation products of phenol / dicyclopentadiene, e.g. 2,5-bis ((2,3-epoxypropoxy) phenyl] octahydro-4,7-methano-5H-indene (CAS No. [13446-85-0]) , Tris [4- (2,3-epoxypropoxy) phenyl] methane isomer) CAS no. [66072-39-7]), Phenol based epoxy novolaks (CAS # [9003-35-4]) and cresol based epoxy novolaks (CAS No. [37382-79-9]). Aliphatic glycidyl ether Examples are 1,4-butanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether, Trimethylolpropane triglycidyl ether, pentaerythritol tetraglycidyl ether, 1,1,2,2-tetrakis [4- (2,3-epoxypropoxy) phenyl] ethane (CAS No. [27043-37-4]), Diglycidyl ether of polypropylene glycol (α, ω-bis (2,3-epoxypropoxy) poly (oxypropylene) (CAS No. [16096-30-3]) and hydrogenated bisphenol A (2,2-bis [4- (2,3-epoxypropoxy) cyclohexyl] propane, CAS-No. [13410-58-7]).

The addition of the epoxy compound can before or at the same time as the oxazoline, however, preferably only in the course of the implementation of the unsaturated carboxylic acid with the oxazoline, for example after at least 10% of the above-mentioned reaction time for the Conversion, preferably after at least 25%, particularly preferably after at least 50%, very particularly preferably after at least 75% and especially after at least 90% of the reaction time.

The molar ratio of added epoxy compound to the α, β-unsaturated carboxylic acid contained in the reaction mixture is in the Rule at most than 1, preferably less than 0.75, particularly preferably less than 0.5, very particularly preferably 0.05 to 0.25 and in particular 0.05 up to 0.15 mol / mol.

Another object of this invention is a polymer available by reacting at least one α, β-unsaturated carboxylic acid with at least one 2-oxazoline and at least one epoxy compound.

worin
m eine positive ganze Zahl zwischen 1 und 500,
R¹, R², R³, R⁴ und R⁵ die oben angeführte Bedeutung aufweisen,
R⁶, R⁷ und R⁸ unabhängig voneinander jeweils Wasserstoff, Phenyl, Hydroxymethyl oder C₁-C₄-Alkyl und
R⁹ Wasserstoff oder eine organischen Rest
bedeuten.The polymer formed in such a reaction corresponds to the formula (II) (after addition of epoxy),

wherein
m is a positive integer between 1 and 500,
R ¹ , R ² , R ³ , R ⁴ and R ^{5 have} the meaning given above,
R ⁶ , R ⁷ and R ⁸ independently of one another are each hydrogen, phenyl, hydroxymethyl or C ₁ -C ₄ alkyl and
R ^{9 is} hydrogen or an organic radical
mean.

worin
R¹, R², R³, R⁴, R⁵, R⁶, R⁷, R⁸ und m die oben genannten Bedeutungen haben,
n eine positive ganze Zahl von 2 bis 10 und
R¹⁰ einen n-valenten organischen Rest
bedeuten.If the epoxy compound is a compound with n epoxy groups, the polymer obtainable has the following formula (III)

wherein
R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ and m have the meanings given above,
n is a positive integer from 2 to 10 and
R ^{10 is} an n-valent organic radical
mean.

The positive integer m is preferred between 1 and 250, particularly preferably between 1 and 100, entirely particularly preferably between 2 and 50 and in particular between 2 and 25.

R ⁶ , R ⁷ and R ⁸ are preferably hydrogen or methyl, particularly preferably hydrogen.

The positive integer n is preferred between 2 and 6, particularly preferably between 2 and 5, very particularly preferably between 2 and 4, in particular 2 or 3 and especially 2.

R ⁹ is preferably hydrogen, methyl, phenyl, vinyl or chloromethyl and particularly preferably hydrogen.

Preferred radicals R ¹⁰ are

Such polymers can have weight-average molar masses M _g (determined by gel permeation chromatography with tetrahydrofuran as eluent and polystyrene as standard) of up to approximately 5000 g / mol, preferably up to 3000, particularly preferably up to 2000 and very particularly preferably up to 1000.

Another subject of the present Invention are radiation curable Masses containing polymers of formula (II) and / or (III).

• (A) mindestens ein erfindungsgemäß hergestelltes Reaktionsgemisch, in dem darin enthaltene α,β-ungesättigte Carbonsäuren mit mindestens einem 2-Oxazolin sowie gegebenenfalls mindestens einer Epoxiverbindung umgesetzt worden sind,
• (B) gegebenenfalls mindestens eine weitere polymerisierbare Verbindung mit einer oder mehreren copolymerisierbaren, ethylenisch ungesättigten Gruppen,
• (C) gegebenenfalls einen oder mehrere photochemisch und/oder thermisch aktivierbare(n) Initiator(en), sowie
• (D) gegebenenfalls weitere lacktypische Additive.

Radiation-curable compositions according to the invention contain, for example

• (A) at least one reaction mixture prepared according to the invention in which the α, β-unsaturated carboxylic acids contained therein have been reacted with at least one 2-oxazoline and, if appropriate, at least one epoxy compound,
• (B) optionally at least one further polymerizable compound having one or more copolymerizable, ethylenically unsaturated groups,
• (C) optionally one or more photochemically and / or thermally activatable initiator (s), and
• (D) optionally other paint-typical additives.

Compounds (B) are known per se for example urethane (meth) acrylates, epoxy (meth) acrylates, carbonate (meth) acrylates or reactive thinner.

The general production of urethane (meth) acrylates is known per se to the person skilled in the art.

The urethane (meth) acrylates preferably have a number average molecular weight M _n of 500 to 20,000, in particular from 750 to 10,000, particularly preferably 750 to 3000 g / mol (determined by gel permeation chromatography using tetrahydrofuran and polystyrene as standard).

The urethane (meth) acrylates preferably have has a content of 1 to 5, particularly preferably 2 to 4, moles of (meth) acrylic groups per 1000 g urethane (meth) acrylate.

The epoxy (meth) acrylates preferably have a number average molecular weight M _n from 340 to 20,000, particularly preferably from 340 to 10,000 g / mol and very particularly preferably from 480 to 3000 g / mol; the content of (meth) acrylic groups is preferably 1 to 5, particularly preferably 2 to 4 per 1000 g of epoxy (meth) acrylate (determined by gel permeation chromatography with polystyrene as standard and tetrahydrofuran as eluent).

Suitable connections (B) are carbonate (meth) acrylates which preferably have an average of 1 to 5, in particular 2 to 4, particularly preferably 2 to 3 (meth) acrylic groups and very particularly preferably contain 2 (meth) acrylic groups.

The number average molecular weight M _{n of} the carbonate (meth) acrylates is preferably less than 3000 g / mol, particularly preferably less than 1500 g / mol, particularly preferably less than 800 g / mol (determined by gel permeation chromatography with polystyrene as standard, solvent tetrahydrofuran).

Radically polymerisable come as reactive diluents Compounds, preferably radiation-curable, with an ethylenic unsaturated, copolymerizable group into consideration, or mixtures thereof.

Examples include α, β-unsaturated carboxylic acids, C ₁ -C ₂₀ alkyl (meth) acrylates, vinyl aromatics with up to 20 C atoms, vinyl esters of carboxylic acids containing up to 20 C atoms, ethylenically unsaturated nitriles, vinyl ethers from 1 to Alcohols containing 10 carbon atoms and aliphatic hydrocarbons with 2 to 8 carbon atoms and 1 or 2 double bonds.

As α, β-unsaturated carboxylic acids, for example Acrylic acid, methacrylic acid, Maleic acid or their half esters, 3-acryloxypropionic acid, maleic anhydride, fumaric acid or their half esters or crotonic acid can be used.

Preferred as (meth) acrylic acid alkyl esters are those with a C ₁ -C ₁₀ alkyl radical, such as methyl methacrylate, methyl acrylate and ethyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate, 2-hydroxyethyl acrylate, 4-hydroxybutyl acrylate, 2- (dimethylamino) ethyl acrylate or diyl acrylate.

In particular, mixtures are also the (meth) acrylic acid alkyl ester suitable.

With vinyl ethers of carboxylic acids 1 to 20 carbon atoms are e.g. Vinyl laurate, vinyl stearate, vinyl propionate and Vinyl acetate.

As vinyl aromatic compounds come e.g. Vinyl toluene, α-butyl styrene, 4-n-butylstyrene, 4-n-decylstyrene and preferably styrene.

Examples of nitriles are acrylonitrile and methacrylonitrile.

Suitable vinyl ethers are e.g. vinyl methyl ether, Vinyl isobutyl ether, vinyl hexyl ether and vinyl octyl ether.

As non-aromatic hydrocarbons with 2 to 8 carbon atoms and one or two olefinic double bonds be butadiene, isoprene, and ethylene, propylene and isobutylene called.

Furthermore, N-vinylformamide, N-vinylpyrrolidone and N-vinylcaprolactam can be used.

As photoinitiators (C) Photoinitiators known to those skilled in the art can be used, e.g. such in "Advances in Polymer Science ", Volume 14, Springer Berlin 1974 or in K.K. Dietliker, Chemistry and Technology of UV- and EB-Formulation for Coatings, Inks and Paints, Volume 3; Photoinitiators for Free Radical and Cationic Polymerization, P.K.T. Oldring (Eds), SITA Technology Ltd, London, mentioned.

Consider for example Phosphine oxides, benzophenones, α-hydroxy-alkyl-aryl-ketones, Thioxanthones, anthraquinones, acetophenones, benzoins and benzoin ethers, Ketals, imidazoles or phenylglyoxylic acids.

Considering mono or bisacylphosphine oxides such as Irgacure ^® 819 (bis (2,4,6-trimethylbenzoyl) phenylphosphine) as described for example in EP-A 7 508 . EP-A 57 474 . DE-A 196 18 720 . EP-A 495 751 or EP-A 615 980 are described further, for example, 2,4,6-trimethylbenzoyldiphenylphosphine oxide (Lucirin ^® TPO), ethyl 2,4,6-trimethylbenzoylphenylphosphinate and bis (2,6-dimethoxybenzoyl) -2,4,4-trimethylpentylphosphine oxide.

Benzophenones are for example Benzophenone, 4-aminobenzophenone, 4,4'-bis (dimethylamino) benzophenone, 4-phenylbenzophenone, 4-chlorobenzophenone, Michler's ketone, o-methoxybenzophenone, 2,4,6-trimethylbenzophenone, 4-methylbenzophenone, 2,4-dimethylbenzophenone, 4-isopropylbenzophenone, 2-chlorobenzophenone, 2,2'-dichlorobenzophenone, 4-methoxybenzophenone, 4-propoxybenzophenone or 4-butoxybenzophenone.

α-hydroxy-alkyl-aryl-ketones Examples are 1-benzoylcyclohexan-1-ol (1-hydroxy-cyclohexylphenyl ketone), 2-hydroxy-2,2-dimethylacetophenone (2-hydroxy-2-methyl-1-phenyl-propan-1-one), 1-hydroxyacetophenone, 1- [4- (2-hydroxyethoxy) phenyl] -2-hydroxy-2-methyl-1-propan-1-one or polymer which is 2-hydroxy-2-methyl-1- (4-isopropen-2-yl-phenyl) propan-1-one polymerized contains (Esacure® KIP 150).

Phenylglyoxylic acids are for example in DE-A 198 26 712 . DE-A 199 13 353 or WO 98/33761.

As further paint-typical additives (D) can for example antioxidants, stabilizers, activators (accelerators), fillers, Pigments, dyes, antistatic agents, flame retardants, Thickeners, thixotropic agents, surface-active agents, viscosity modifiers, Plasticizers or chelating agents can be used.

Furthermore, one or more initiators which can be activated photochemically and / or thermally can be added, for example potassium peroxodisulfate, dibenzoyl peroxide, cyclohexanone peroxide, di-tert-butyl peroxide, azobis-isobutyronitrile, cyclohexylsulfonylacetyl peroxide, di-isopropyl percarbonate, tert-butyl peroxate and tert-butyl peroxate for example, those thermally activatable initiators that have a half-life at 80 ° C have more than 100 hours, such as di-t-butyl peroxide, cumene hydroperoxide, dicumyl peroxide, t-butyl perbenzoate, silylated pinacoles, which are commercially available, for example, under the trade name ADDID 600 from Wacker or amine N-oxides containing hydroxyl groups, such as 2. 2,6,6-tetramethylpiperidine-N-oxyl, 4-hydroxy-2,2,6,6-tetramethylpiperidine-N-oxyl etc.

Further examples of suitable initiators are in "polymer Handbook ", 2nd ed., Wiley & Sons, New York described.

In addition to radicals, as thickeners (Co) polymerized (co) polymers, common organic and inorganic Thickeners such as hydroxymethyl cellulose or bentonite can be considered.

As chelating agents e.g. ethylenediamineacetic and their salts and β-diketones be used.

Suitable fillers include silicates, e.g. obtainable by hydrolysis of silicon tetrachloride Silicates such as Aerosil® Degussa, silica, talc, aluminum silicates, magnesium silicates, Calcium carbonates etc.

Suitable stabilizers include typical UV absorbers such as oxanilides, triazines and benzotriazole (the latter available as Tinuvin® brands Ciba Specialty Chemicals) and benzophenones. these can alone or together with suitable radical scavengers, for example sterically hindered amines such as 2,2,6,6-tetramethylpiperidine, 2,6-di-tert-butylpiperidine or their derivatives, e.g. Bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, be used. Stabilizers are usually sold in quantities of 0.1 to 5.0 wt .-%, based on those contained in the preparation solid components.

• (A) 20–100 Gew.-%, bevorzugt 40–90, besonders bevorzugt 50– 90 und insbesondere 60–80 Gew.-%,
• (B) 0–70 Gew.-%, bevorzugt 5–50, besonders bevorzugt 6–40 und insbesondere 10–30 Gew.-%,
• (C) 0–20 Gew.-%, bevorzugt 0,5–15, besonders bevorzugt 1–10 und insbesondere 2–5 Gew.-% sowie
• (D) 0–50 Gew.-%, bevorzugt 2–40, besonders bevorzugt 3–30 und insbesondere 5–20 Gew.-%,

mit der Maßgabe, dass (A), (B), (C) und (D) zusammen 100 Gew.-% ergeben.Typical compositions for the radiation-curable compositions according to the invention are, for example

• (A) 20-100% by weight, preferably 40-90, particularly preferably 50-90 and in particular 60-80% by weight,
• (B) 0-70% by weight, preferably 5-50, particularly preferably 6-40 and in particular 10-30% by weight,
• (C) 0-20% by weight, preferably 0.5-15, particularly preferably 1-10 and in particular 2-5% by weight and
• (D) 0-50% by weight, preferably 2-40, particularly preferably 3-30 and in particular 5-20% by weight,

with the proviso that (A), (B), (C) and (D) together make up 100% by weight.

The content of the reaction products the α, β-unsaturated carboxylic acids and the 2-oxazoline, e.g. the polymers of the formula (II) or (III), in the reaction mixture (A) is of course dependent on the amount of it contained α, β-unsaturated carboxylic acid and the amount of 2-oxazoline used. The content of these reaction products in (A) can be up to 80% by weight, preferably up to 60, particularly preferably up to 45, very particularly up to 20, in particular up to 15 and especially up to 5% by weight.

The substrates are coated with the radiation-curable compositions according to the invention by customary processes known to those skilled in the art, at least one dispersion or coating formulation being applied to the substrate to be coated in the desired thickness and the volatile constituents of the dispersions being removed, if appropriate with heating. If desired, this process can be repeated one or more times. It can be applied to the substrate in a known manner, for example by spraying, filling, knife coating, brushing, rolling, rolling, casting, laminating, back-molding or coextruding. The coating thickness is generally in a range from about 3 to 1000 g / m ² and preferably 10 to 200 g / m ² .

Furthermore, a method for Coating substrates disclosed, in which the coating composition applied to the substrate and dried, if necessary, with electron beams or UV exposure under an oxygen-containing atmosphere or preferably cures under inert gas, if necessary at temperatures up to the drying temperature and subsequently at temperatures up to 160 ° C, preferably between 60 and 160 ° C, thermally treated.

The process for coating Substrates can also be done this way be that after the application of the coating compound initially at Temperatures up to 160 ° C, preferably between 60 and 160 ° C, thermally treated and then with electron beams or UV exposure under oxygen or preferably under inert gas hardened becomes.

The hardening of the on the substrate formed films can if desired exclusively thermally. Generally the coatings are cured however, both by irradiation with high-energy radiation and also thermal.

The hardening can also be additional or instead of thermal curing done by NIR radiation, with NIR radiation being electromagnetic here Radiation in the wavelength range from 760 nm to 2.5 μm, is preferably designated from 900 to 1500 nm.

If necessary, if several Layers of the coating agent are applied one above the other, thermal, NIR and / or radiation curing is carried out after each coating process.

Suitable radiation sources for radiation curing are, for example, low-pressure mercury lamps, medium-pressure lamps with high-pressure lamps and fluorescent tubes, pulse lamps, metal halide lamps, Electronic flash devices, which enables radiation curing without a photoinitiator, or excimer emitters. Radiation curing is effected by exposure to high-energy radiation, that is to say UV radiation or daylight, preferably emitting light in the wavelength range from λ = 200 to 700 nm, particularly preferably from λ = 200 to 500 nm and very particularly preferably λ = 250 to 400 nm, or by Irradiation with high-energy electrons (electron radiation; 150 to 300 keV). High-pressure mercury vapor lamps, lasers, pulsed lamps (flashing light), halogen lamps or excimer lamps are used as radiation sources. The radiation dose usually sufficient for crosslinking in UV curing is in the range from 80 to 3000 mJ / cm ² .

Of course there are also several radiation sources for the hardening applicable, e.g. two to four.

These can also be different Wavelength ranges radiate.

Irradiation can optionally also in the absence of oxygen, e.g. be carried out under an inert gas atmosphere. Suitable inert gases are preferably nitrogen, noble gases, carbon dioxide, or Combustion gases. Furthermore, the radiation can take place by the coating material is covered with transparent media. Transparent media are e.g. Plastic films, glass or liquids, e.g. Water. Irradiation is particularly preferred in such a way that like they did in the older one German application with the file number 199 57 900.8 is.

• i) ein Substrat mit einer Dispersion, wie zuvor beschrieben, beschichtet,
• ii) flüchtige Bestandteile der Dispersion zur Filmbildung unter Bedingungen entfernt, bei denen der Initiator (C) im wesentlichen noch keine freien Radikale ausbildet,
• iii) gegebenenfalls den in Schritt ii) gebildeten Film mit energiereicher Strahlung bestrahlt, wobei der Film vorgehärtet wird, und anschließend gegebenenfalls den mit dem vorgehärteten Film beschichteten Gegenstand mechanisch bearbeitet oder die Oberfläche des vorgehärteten Films mit einem anderen Substrat in Kontakt bringt,
• iv) dem Film thermisch endhärtet.

Another object of the invention is a method for coating substrates, wherein

• i) coating a substrate with a dispersion as described above,
• ii) volatile constituents of the dispersion are removed for film formation under conditions in which the initiator (C) essentially does not yet form any free radicals,
• iii) optionally irradiating the film formed in step ii) with high-energy radiation, the film being prehardened, and then optionally machining the object coated with the prehardened film or bringing the surface of the prehardened film into contact with another substrate,
• iv) thermally cures the film.

Steps iv) and iii) also performed in reverse order, d. H. the film can go first be cured thermally and then with high-energy radiation.

The coating compositions according to the invention are suitable are particularly suitable for coating substrates such as wood, paper, Textile, leather, fleece, plastic surfaces, glass, ceramics, mineral Building materials, such as shaped cement blocks and fiber cement panels, or metals or coated metals, preferably plastics or metals.

The are particularly preferred coating compositions according to the invention as or in outer coatings, so those applications that are exposed to daylight are preferred of buildings or Parts of buildings, Interior coatings, road markings, Coatings on vehicles and aircraft. In particular the coating compositions according to the invention used as or in automotive clearcoat and topcoat (s).

The radiation-curable materials obtainable according to the invention Masses have a low content of α, β-unsaturated carboxylic acids and additionally show a low viscosity, a lower color number, improved resistance to yellowing and improved adhesion to substrates such as e.g. Wood, paper and Metal, without the remaining properties like chemical resistance, To affect scratch resistance. This makes it easy to make clear and non-yellowing Clear varnishes possible.

The method according to the invention is an example here illustrated: In the esterification of (meth) acrylic acid with a hydroxy compound are preferably 0.1 to 1.5, especially preferably 0.5 to 1.4 and very particularly preferably 0.7 to 1.3 equivalents (Meth) acrylic acid, based on 1 hydroxy equivalent of the hydroxy compounds used.

The reaction of the (meth) acrylic acid with the hydroxy compounds can e.g. in the presence of an acidic esterification catalyst, such as. Sulfuric acid, p-toluenesulfonic acid, Dodecylbenzenesulfonic acid or acidic ion exchanger and in the presence of a hydrocarbon, which forms an azeotropic mixture with water, especially up to a conversion of, for example, at least 85%, preferably at least 90, very particularly preferably 90 to 98% and in particular 90-95% of the Hydroxy groups of the hydroxy compound, for example at 60 to 140 ° C become. The water of reaction formed is removed azeotropically. suitable Hydrocarbons are aliphatic and aromatic, e.g. alkanes and cycloalkanes such as pentane, n-hexane, n-heptane, methylcyclohexane and cyclohexane, aromatics such as benzene, toluene and the xylene isomers, and so-called special gasoline, which have boiling points between 70 and 140 ° C.

To avoid premature polymerization, the reaction with (meth) acrylic acid is advantageously carried out in the presence of small amounts of inhibitors. These are the usual compounds used to prevent thermal polymerization, for example of the hydroquinone type, the hydroquinone monoalkyl ether, especially hydroquinone monomethyl ether, the 2,6-di-t-butylphenol, the N-nitrosoamine, the phenothiazine, the phosphoric acid ester or the hypophosphorous acid. she are generally used in amounts of 0.001 to 2.0%, preferably in amounts of 0.005 to 0.5%.

After esterification, the solvent, e.g. the hydrocarbon, from the reaction mixture by distillation, optionally under reduced pressure. The esterification catalyst can be appropriately neutralized, e.g. by adding tertiary Amines or alkali hydroxides. Also over liquid (meth) acrylic acid can partly e.g. be removed by distillation in vacuo.

The reaction product shows before the start the reaction with the oxazoline generally still has an acid number (SZ, according to DIN EN 3682) above 25, preferably from 35 to 300, particularly preferably from 35 to 250 mg KOH / g substance (without solvent) on.

Then the reaction product implemented as described above with at least one 2-oxazoline.

Compared to, for example, bisphenol A diglycidyl ether is a significantly smaller amount of, for example, 2-ethyl-2-oxazoline necessary to implement α, β-unsaturated carboxylic acids contained in the reaction mixture.

It is also used for reaction with oxazolines no external catalyst required.

Ppm- used in this document and percentages relate to unless otherwise stated Percentages by weight and - ppm.

Examples

example 1

To a polyether acrylate with a of acid number gem. DIN EN ISO 3682 of 30 mg KOH / g, was at one temperature from 60-100 ° C over 2 hours 5% by weight of 2-ethyl-2-oxazoline and then 2% by weight of bisphenol A diglycidyl ether over 2 hours up to an acid number of less than 5 mg KOH / g added. The viscosity was 300 mPas.

This coating composition was Ciba Specialty Chemicals mixed with 4 wt .-% photoinitiator Irgacure 500 ^® coated a doctor blade on wood and glass by means of, and five times under an undoped high-pressure mercury lamp (power 120 W / cm) having a lamp substrate distance of 12 cm and exposed to a belt speed of 5 m / min. The layer thickness after exposure was 50 μm.

The Erichsen deepening was according to DIN 53156 determines and is a measure of flexibility and elasticity. The information takes place in millimeters (mm). High values mean high flexibility.

The liability with cross cut was according to DIN 53151 determined and given in grades. Small values mean high ones Liability.

The chemical resistance was acc. Compared to DIN 68860 Sodium carbonate, red wine, instant coffee, black currant juice, Ethyl butyl acetate, mustard, lipstick, disinfectant, black Ballpoint pen and detergent determined and according to optical Assessment graded. Low grades mean high chemical resistance.

The viscosity was measured using a cone-plate viscometer at 25 ° C certainly.

The coating showed chemical resistance from 1.1 (optical assessment).

Example 2

To a polyether acrylate with a of acid number gem. DIN EN ISO 3682 of 30 mg KOH / g was 6 wt .-% 2-ethyl-2-oxazoline at a Temperature from 60-100 ° C up to an acid number of <5 mg KOH / g added. The viscosity was 290 mPas.

The coating mass became analog Example 1 examined.

Comparative example

To a polyether acrylate with a of acid number gem. DIN EN ISO 3682 of 30 mg KOH / g, 10 wt .-% bisphenol A diglycidyl ether over 6 hours at a temperature of 80-100 ° C up to an acid number of <6 mg KOH / g added. The viscosity was 600 mPas.

The coating mass became analog Example 1 examined.

table

Claims (15)

Process for the separation of α, β-unsaturated carboxylic acids from the reaction mixtures containing them by reacting the α, β-unsaturated carboxylic acids with at least one 2-oxazoline, characterized in that the content of α, β-unsaturated carboxylic acid in the reaction mixture before the reaction with the 2-oxazoline is not more than 20% by weight. Method according to claim 1, characterized in that it is the reaction mixture a reaction mixture of an esterification of the α, β-unsaturated carboxylic acid with is at least one compound that has at least one hydroxy group contains. A method according to claim 1 or 2, characterized in that the 2-oxazoline has the formula (I),

wherein R ¹ , R ² , R ³ , R ⁴ and R ⁵ independently of one another are each hydrogen, C ₁ -C ₁₈ alkyl, optionally interrupted by one or more oxygen and / or sulfur atoms and / or one or more substituted or unsubstituted imino groups C ₂ -C ₁₈ alkyl, C ₆ -C ₁₂ aryl, C ₆ -C ₁₂ cycloalkyl or a five- to six-membered heterocycle containing oxygen, nitrogen and / or sulfur atoms or two of them together represent an unsaturated, saturated or form an aromatic ring which is optionally interrupted by one or more oxygen and / or sulfur atoms and / or one or more substituted or unsubstituted imino groups, the radicals mentioned being each by functional groups, aryl, alkyl, aryloxy, alkyloxy, halogen, heteroatoms and / or heterocycles can be substituted. Procedure according to a the preceding claims, characterized in that the 2-oxazoline is selected from the group 2-ethyl-2-oxazoline, 2-methyl-2-oxazoline, 2-oxazoline, 2,4,4-trimethyl-2-oxazoline, 4,4-dimethyl-2-oxazoline and 2-ethyl-4,4-dimethyl-2-oxazoline. Procedure according to a the preceding claims, characterized in that the reaction mixture additionally with at least one epoxy compound is implemented. Method according to claim 5, characterized in that the molar ratio of added epoxy compound to the α, β-unsaturated carboxylic acid contained in the reaction mixture less than 0.75 mol / mol. A radiation Masses containing a reaction mixture in the α, β-unsaturated carboxylic acids contained therein at least one 2-oxazoline have been reacted. Radiation-curable compositions containing a reaction mixture in the α, β-unsaturated contained therein te carboxylic acids have been reacted with at least one 2-oxazoline and additionally with at least one alkylene oxide or glycidyl ether. Polymer, available by reacting at least one α, β-unsaturated carboxylic acid with at least one 2-oxazoline and at least one epoxy compound. Polymer according to claim 9, characterized in that it corresponds to the formula (II),

wherein R ¹ , R ² , R ³ , R ⁴ and R ^{5 have} the meaning given in claim 3, R ⁶ , R ⁷ and R ⁸ independently of one another are each hydrogen, phenyl, hydroxymethyl or C ₁ -C ₄ alkyl and R ⁹ Is hydrogen or an organic radical. Polymer according to claim 9, characterized in that it corresponds to the formula (III),

wherein R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ and m have the meanings given in Claims 3 and 9, n is a positive integer from 2 to 10 and R ^{10 is} one n-valent organic residue. A radiation Masses containing polymers according to one of claims 9 to 11. A radiation Masses containing (A) at least one reaction mixture, in the α, β-unsaturated carboxylic acids contained therein at least one 2-oxazoline and optionally at least one Epoxy compound have been implemented, (B) optionally at least another polymerizable compound with one or more copolymerizable, ethylenically unsaturated groups, (C) if necessary one or more photochemically and / or thermally activatable Initiator (s), and (D) if appropriate, further paint-typical Additives. Process for coating substrates, thereby characterized in that a radiation-curable composition according to a of claims 9 to 13 is used. Use of 2-oxazines for the separation of α, β-unsaturated carboxylic acids from the reaction mixtures containing them by reacting the α, β-unsaturated carboxylic acids with the at least one nem 2-oxazoline, the content of α, β-unsaturated carboxylic acid in the reaction mixture before the reaction with the 2-oxazoline being not more than 20% by weight.