DE10225367C1 - Curable prepolymer formulations, used as lacquer binder, contain urethane (meth)acrylate, acetoacetate or enamine-functionalized derivative of polyol obtained by ring opening and/or hydrolysis of epoxidized vegetable oil - Google Patents

Abstract

Curable formulations contain prepolymer (binder) derived from polyol (I) based on vegetable oil (II) (triglycerides) and obtained by opening and/or hydrolyzing oxirane rings of epoxidized (II) or reaction product. (I) are converted to urethane (meth)acrylate (IIIA) with diisocyanate-hydroxy-functional (meth)acrylate adduct; acetoacetate (IIIB) with acetoacetic acid or diketene; enamine-functionalized derivative (IIIC) from (IIIB) and primary or secondary amine or ammonia. Curable formulations contain prepolymer(s) (binder) derived from polyol(s) (I) based on vegetable oils (II) (mainly triglycerides) and obtained by opening and/or hydrolyzing oxirane rings of epoxidized (II) or directly from the reaction product of (II) with peroxycarboxylic acids or hydrogen peroxide in the presence of carboxylic acids, followed by direct ring opening and/or hydrolysis. (I) act as base for conversion to (a) (II)-urethane (meth)acrylates (IIIA) by reaction with reaction products (adducts) of diisocyanate(s) and hydroxy-functional (meth)acrylate(s), (b) (II) acetoacetates (IIIB) by reaction with acetoacetic acid or diketene or (c) enamine-functionalized (II) derivatives (IIIC) by further reaction of (IIIB) with primary or secondary amines or ammonia. An Independent claim is also included for the preparation of curable formulations in this way, in which stage (c) gives (II) derivatives containing aminocrotonate (enamine) groups.

Description

The invention relates to curable preparations, which prepolymers (in particular for Paint binders) based on reaction products of epoxidized vegetable oils include, as well as processes for the preparation of said prepolymers.

The basis for this are epoxidized vegetable oils, which are first subjected to a ring opening and / or hydrolysis of the oxirane rings (without cleavage of the triglycerides). The resulting polyol oils can be reacted further in subsequent reaction stages, either

• - To vegetable oil urethane (meth) acrylates by reaction with diisocyanates and hydroxy-functional (meth) acrylate monomers or
• - to acetoacetate-functional oils by reaction with esters of acetoacetic acid or with diketene or
• - to aminocrotonate - ("enamine" -) functional vegetable oil derivatives subsequent reaction of the acetoacetate-functional oils with primary or with secondary amines or with ammonia.

The reaction products of the polyol oils are suitable as binders for solvent-free or low-solvent, chemically cross-linking coating materials, crosslinking in the form of photopolymerization (radiation curing) or a vinylogenic addition reaction (as thermal curing) can take place.

It is known to avoid or reduce environmental and harmful emissions of volatile organic solvents Coating systems water-thinnable coating materials, high solids, powder coatings or use radiation-curing coating materials.  

It is also known that the radiation-curing coating materials are liquid, solvent-free materials, being polymerizable, radical crosslinking resins and reactive thinners based on acrylates as Binder basis dominate. The networking process is done either by Electron radiation or started by UV radiation (in the latter case under Using photoinitiators that are able to absorb UV radiation absorb and then generate the required starting radicals) and results in Cured coatings in seconds or fractions of a second.

Radiation-curing systems are used today, for. B. in the coating of papers and foils as well as wooden surfaces, also as printing inks, Overprint varnishes, adhesives and. a.

As polymerizable, radical crosslinking acrylate binders are among other also vegetable oil epoxy acrylates (addition products of epoxidized oils with Acrylic acid), mostly based on soybean oil, as well as "oil modified" acrylates (with Resins modified with fatty acid groups). The disadvantage of this is the limitation the amounts that can be used, since high proportions of vegetable oil epoxy acrylates are relative soft, qualitatively inadequate coatings would result.

Cationic UV-curing lacquer systems are also known, which, for. B. also on the Base of epoxidized vegetable oils can be produced [see W. Sack, A. Lott, D. Bartmann, O. Metzger and U. Lübker, NAROSSA 2000, Magdeburg, Conference proceedings and patent DE 100 01 476]. However, these are achievable Properties in terms of hardness and reactivity are also very limited.

Solvent-reduced coating materials or are also known Varnish binder under the name "High-Solids". That term is however not clearly defined. This means materials that (depending on Default) not more than 20 or 30% volatile organic solvents contain. To achieve this, special coating resins with less Intrinsic viscosity required, possibly also special solvents.  

Regarding the drying or hardening of high solids come in general Mechanisms for use, which are also known from conventional paint systems are.

However, other, relatively new networking mechanisms for high solids are also known; this includes vinylogous addition. Acetoacetate-modified resins can be used as binders with lower viscosity. These can e.g. B. by transesterification of polyester or polyether polyols with tert-butyl acetoacetate (120-140 ° C, N ₂ atmosphere) or by reaction with diketene. If necessary, the acetoacetate-modified resins thus synthesized can be reacted further in the reactor with equimolar amounts of amines, resins with aminocrotonate ("enamine") groups being formed. Both acetoacetate-modified resins and enamine-modified resins crosslink at elevated temperatures with α, β-unsaturated carbonyl compounds, e.g. B. acrylates (acetoacetates preferably in the presence of basic catalysts) [see: N. Pietschmann, K. Stengel and B. Hößelbarth, Progr. Org. Coat. 36, 1999, pp. 64-69; N. Pietschmann, I. Peter and K. Stengel, XXV. FATIPEC Congress, Turin 2000, Tagungsband 4, pp. 119-133 and the journal and patent literature cited there].

The disadvantage of water-dilutable coating materials, high solids, Powder coatings or radiation-curing coating materials that such Materials are not universally applicable and not all of them Quality standards of sophisticated, conventional, solvent-based Coating materials can be achieved.

Another disadvantage is that the paint binders for water-dilutable Coating materials, high solids, powder coatings or radiation-crosslinking Coating materials are predominantly fully synthetic, d. H. fossil Carbon sources (oil, coal) serve as the original starting point.  

If appropriate products (or with the appropriate coating materials coated substrates) - at the end of their service life at the latest and disposed of, the carbon it contains will sooner or later It converts carbon dioxide and pollutes the atmosphere.

In addition, the mostly oligomeric basic structures are synthesized Binder with high expenditure of time and energy; in fossil or native There are hardly any "chemical building blocks" that are already available used.

That means the environmental friendliness of the usual radiation-curing systems, high- Solids, powder coatings and water-based coatings are essentially limited to one Reduction or elimination of the solvent content in the coating materials. On the other hand, the overall ecological balance has proven to be disadvantageous. H. including the Manufacture of the binders that form the basis of the coating materials represent.

The object of the invention is based on native vegetable oils, d. H. by growing raw materials Varnish binders for radiation-curing coating materials and To create high solids that combine the advantages and quality features of the well-known, solvent-free or solvent-reduced binders on a fully synthetic basis exhibit, but improve their disadvantageous, unfavorable life cycle assessment.

According to the invention, this object is achieved as specified in the claims.

For further chemical implementation, the epoxy groups are first (Oxirane rings) opened by epoxidized oils to replace them with functional ones Introduce groups that enable later networking in the paint film should. Because the goal is the synthesis of high molecular paint film formers, The natural triglyceride structure of the oils should largely remain.  

Therefore mild reaction conditions are chosen. For example, is suitable treatment of the epoxidized oil with formic acid / water mixtures (e.g. 2 h at 40 ° C). This gives polyol oils that have one instead of an oxirane ring 1,2-diol unit (i.e. two adjacent "vicinal" OH groups). On The advantage of this approach is that it potentially higher number of linking points is generated (theoretically up to two instead one per epoxy group), even if - due to incomplete hydrolysis of a part of the oxirane rings - partially hydroxy formate groups (i.e. only one OH group as well a formic acid ester group) in addition to the 1,2-diol groups.

In an analogous manner, it is also possible to use the acid hydrolysis as a "one-pot reaction" perform the same reaction approach as the Prileshaev epoxidation, e.g. B. after epoxidation of the vegetable oil with performic acid (or with Hydrogen peroxide + formic acid).

The polyols thus produced (hereinafter also referred to as "polyol oils") the preliminary stage or starting point for the prepolymers, which are part of the Preparations according to the invention are.

In further reaction steps, adducts of hydroxy-functional (meth) acrylates and diisocyanates are first prepared, e.g. B. from hydroxyethyl acrylate and isophorone diisocyanate. The stoichiometric ratio is 1: 1, so that one isocyanate group per molecule remains free in the adduct ( Fig. 1):

Fig. 1 Adduct formation from a hydroxy (meth) acrylate and a diisocyanate

R = H or CH ₃

R ¹

= C _n

H _2n

, e.g. B. C ₂

H ₄

R ²

= any, e.g. B. residues of isophorone, hexamethylene (C ₆

H ₁₂

), Diphenylmethane, hydrogenated diphenylmethane, 2,4-tolylene or 2,6-tolylene

CHR = CH-CO-OR ¹ -OH + OCN-R ² -NCO → CHR = CH-CO-OR ¹ -O-CO-NH-R ² -NCO
These hydroxy (meth) acrylate-isocyanate adducts are reacted with the polyol oils to give vegetable oil urethane (meth) acrylates. Fig. 2 shows this reaction schematically using the example of the reaction of a 1,2-diol unit on a fatty acid chain of the triglyceride:

Fig. 2 Addition reaction to vegetable oil urethane (meth) acrylate

R = H or CH ₃

R ¹

= C _n

H _2n

, e.g. B. C ₂

H ₄

R ²

= any, e.g. B. residues of isophorone, hexamethylene (C ₆

H ₁₂

), Diphenylmethane, hydrogenated diphenylmethane, 2,4-tolylene or 2,6-tolylene

The vegetable oil urethane acrylates are used together with reactive thinners and a photoinitiator in radiation-curing preparations (especially radiation-curing lacquer preparations). For example, with 50% by mass of a highly functional vegetable oil urethane acrylate very hard Coatings.

This finding is surprising because vegetable oil derivatives are otherwise relatively soft films result (e.g. radically UV-hardened vegetable oil epoxy acrylates or cationically UV-hardened vegetable oil epoxies). A likely explanation for this is that the synthesized vegetable oil urethane acrylates have a very high  Have acrylate functionality per triglyceride molecule which corresponds to that with the technical Common vegetable oil epoxy acrylates significantly exceeds achievable values (Example: In the case of commercial soybean oil epoxy acrylates, from approx. 2.5 to 3 Acrylate groups per triglyceride. One in the manner described above Soybean oil urethane acrylate produced, on the other hand, gave about 5 acrylate groups each Triglycerideinheit).

Based on this, UV-curing coating materials with a very high vegetable oil content and with an optimally adjusted ratio between hardness and flexibility are obtained by either

• - The highly functional vegetable oil urethane (meth) acrylates with lower functional Vegetable oil-epoxy-acrylates can be combined or
• - Vegetable oil urethane (meth) acrylates with "medium" acrylate functionality synthesized and be used.

The higher-functional vegetable oil urethane (meth) acrylates described here thus differ both in the way of production and in their properties significantly of those described in the patent literature [Pat. CH 679310 (Sicpa Holding S.A.) and Pat. JP 53115307 (Morohoshi Printing Ink Co.)] called urethane acrylates on the Base of castor oil, which already contains OH groups in its natural state.

Fig. 3 Transesterification reaction to vegetable oil acetoacetate

R: z. B. C (CH ₃

) ₃

- (tert-Butyl), C ₂

H ₅

-, CH ₃

-

Another variant of the paint binders according to the invention based on polyol oils consists of acetoacetate-functionalized vegetable oil derivatives. For this purpose, the polyol oils with esters of acetoacetic acid, for. B. implemented tert-butylacetoacetate (z. B. 120-140 ° C, N ₂ atmosphere). Fig. 3 shows this reaction schematically using the example of the reaction of a 1,2-diol unit on a fatty acid chain of the triglyceride.

Alternatively, acetoacetate-modified vegetable oil derivatives can also be obtained by reacting the Polyol oils can be produced with diketene.

The acetoacetate-modified vegetable oil derivatives obtained have significantly lower ones Viscosities than the polyol oils used.

Furthermore, it is alternatively possible to produce enamine-functionalized vegetable oil derivatives based on acetoacetates. For this purpose, acetoacetate-functionalized vegetable oil derivatives are further reacted with ammonia, primary amines (e.g. n-butylamine) or secondary amines. Fig. 4 shows the corresponding implementation of a 1,2-diol unit on a fatty acid chain of the triglyceride:

Fig. 4 Implementation of a vegetable oil acetoacetate to the corresponding enamine derivative

R = H or C _n

H _{2n + 1}

, e.g. B. C ₄

H ₉

(N-butyl)

The amine is initially added at 40-60 ° C. After the addition has taken place, the products are heated to 120-140 ° C. and kept under N ₂ flow for 90 minutes to complete the reaction and to drive off the water of reaction. This second modification step led to slightly yellowish resins with a higher viscosity than the corresponding acetoacetates.

Both the acetoacetate-functionalized vegetable oil derivatives and the enamine-functionalized vegetable oil derivatives are cured at elevated temperatures (e.g. 120-150 ° C) with α, β-unsaturated carbonyl compounds, e.g. B. with unsaturated acrylates ( Fig. 5). Here, especially when acetoacetates are used, basic catalysts (e.g. DBN, DBU or tetramethylguanidine) should be present.

Fig. 5 Schematic representation of the crosslinking reaction of an acetoacetate (a) or an enamine (b) with an acrylate

R = fatty acid residue of a triglyceride molecule,
R ¹

= any basic body of the (meth) acrylate monomer or (meth) acrylate oligomer

The following are used as acrylates:

• - Different commercial acrylate oligomers or acrylate monomers (as Resins or reactive thinners for radiation-curable coating materials commercially available)
• - Vegetable oil urethane (meth) acrylates synthesized according to the invention (as already described)
• - vegetable oil epoxy acrylates.

Instead of acrylates there are also other α, β-unsaturated carbonyl compounds, z. B. methacrylates, maleates or fumarates can be used.

The composition is chosen, for example, so that the number of Acrylate groups and the number of acetoacetate groups or enamine groups correspond approximately to each other (equimolar approach). After the thermal Depending on the reactants used, hardening or hardening occurs more flexible lacquer films of mostly good solvent and water resistance as well as good Substrate adhesion, even on non-pretreated steel.

The advantages of the invention are that based on renewable Raw materials (native vegetable oils) high quality paint binders for radiation-curing coating materials and high solids have been created Advantages of known, solvent-free or reduced-solvent, have fully synthetic paint binders, but their inadequate Avoid or improve the ecological balance. The paint binders according to the invention are characterized by good mechanical and chemical resistance properties out.

The invention is explained in more detail below using exemplary embodiments.

example 1

19.1 parts by weight of epoxidized linseed oil were used to produce polyol oils (Epoxy equivalent weight 191 g / mol) to 100 parts by weight of formic acid Water mixtures  different concentration ratios (weight of formic acid: water) 70: 30, 50: 50, 40: 60 or 10: 90). The whole was stirred at 40 ° C warmed and left at this temperature for 2 hours. After that Formic acid and water - either immediately or after another 24 hours Room temperature or after warming to 90 ° C for 30 minutes - in a vacuum distilled off (rotary evaporator), so that the highly viscous polyol oil remained.

In some cases, the polyol oil was left from the last residues Formic acid freed. For this it was first diluted with methylene chloride, then twice with saturated sodium bicarbonate solution and once with Washed saline, dried and the methylene chloride in vacuo distilled off.

In all reaction batches using the formic acid-water Mixtures 70: 30, 50: 50 and 40: 60 could be made Disappearance of the oxirane rings, the formation of OH groups as well as the No formation of COOH groups (i.e. the preservation of the triglycerides) by means of IR Spectroscopy. In contrast, there was none with the 10:90 mixture detect significant changes compared to epoxidized linseed oil.

A polyol oil prepared using the 50:50 formic acid-water mixture was examined by ¹ H-NMR. Signals in the range of 7.9 to 8.4 ppm indicated that formate groups were still present, ie incomplete hydrolysis. The intensity evaluation showed approx. 40% hydroxyformate per original epoxy group, ie approx. 60% 1,2-diol.

Example 2

The production of a vegetable oil urethane acrylate was based on a polyol oil which had been prepared by reacting epoxidized soybean oil (with an epoxy equivalent weight of 246 g / mol with formic acid + water / 50:50). According to IR spectroscopy and ¹ H-NMR evaluation, the oxirane rings were completely converted, with about 32% hydroxyformate or correspondingly about 68% diol being formed.

First, 22.2 g (0.1 mol) of isophorone diisocyanate with 0.126 g (0.002 mol) Dibutyltin dilaurate and with 0.125 g of finely ground phenothiazine or / and treated with 0.5 g of 4-methoxyphenol. With stirring and cooling 11.6 g (0.1 mol) of hydroxyethyl acrylate were added. The mixture became then kept at 40 ° C for one to four hours (Alternatively, this can also be Hydroxyethyl acrylate submitted and the dibutyltin dilaurate to the mixture can be added quickly, but ice cooling is required first because a Temperature peak occurs.).

Then 15.9 g of the above. Polyol oil for better fluidity heated to 70 ° C and to the adduct of isophorone diisocyanate and Hydroxyethyl acrylate added (the amount of free isocyanate groups in the Adduct corresponds approximately to the amount of OH groups in the polyol oil).

After the exothermicity had subsided, the mixture became a kept at 60 ° C for up to three hours. In the end, the highly viscous obtained Resin with an acrylate monomer (e.g. tripropylene glycol diacrylate in an amount of 35-40%) and if necessary with additional 4-methoxyphenol (300 ppm) nachstabilisiert. The IR spectrum of the resin produced in this way showed very little small residues of unreacted isocyanate.

Example 3

For testing a vegetable oil urethane acrylate in a UV-curing Lacquer preparation was 78.7 percent by mass of a 64% solution of a soybean oil Urethane acrylates in tripropylene glycol diacrylate (prepared as in the previous Example described; the stated quantity corresponds to 50 percent by mass of the pure resin) with a further 17.8 mass percent tripropylene glycol diacrylate and with 3.0 percent by mass of a photoinitiator (Darocur 1173, manufacturer CIBA) and 0.5 Mass percent of a leveling additive (BYK-306, manufacturer BYK-Chemie) mixed.

The approach was applied manually to glass and sheet steel (application device with 200 µm gap height; this results in 100-120 µm dry film thickness). The hardening was carried out using a medium pressure mercury vapor lamp (80 W / cm) at 5, 10 or 20 m / min. In all cases there were very hard surfaces; the Pendulum damping values according to KÖNIG were in the range of 130-160 s.  

However, the low cupping values found on steel showed that the cupping was too high Brittleness.

In further tests carried out analogously, by combining the Soybean oil urethane acrylates with other acrylate oligomers, for example with one Soybean oil epoxy acrylate, coatings of more balanced hardness and flexibility receive.

Example 4

The same polyol was used to produce a vegetable oil acetoacetate Soybean oil based, which was already given in Example 2 as the starting material has been.

68 g of this polyol oil were after being heated to 60 ° C in one Four-necked flask filled with a thermometer, a dropping funnel and a descending cooler was equipped. After heating to 120 ° C were under Stir within 60 minutes 57 g of tert-butylacetoacetate (this amount corresponds to approx. 85% of the OH groups present.) via a dropping funnel gradually added. The released tert-butanol distilled over and was caught in a round bottom flask at the end of the descending cooler.

After the addition was complete, the dropping funnel was closed by a Gas inlet tube replaced so that the reaction mixture with a slight Nitrogen flow could be applied. The approach was completed stirred for a further 2 hours at 120 ° C. and then for a further 2 hours at 140 ° C. held. The heat supply was then stopped. After cooling The gas inlet pipe was also removed below 80 ° C.

The evaluation of the increase in mass of the resin in the reaction flask showed a complete implementation of the acetoacetate. The viscosity of the obtained Acetoacetoxylated soybean oil derivative was significantly lower than that of the corresponding polyol oil.  

Example 5

For the production of an enamine-functionalized soybean oil derivative, the acetoacetate, the preparation of which was described in Example 4 has been. Of these, 30 g were placed in a four-necked flask equipped with a Thermometer, a dropping funnel and a reflux condenser was equipped. To 9 g of n-butylamine were heated to 60 ° C. with stirring within 20 minutes dropwise.

The mixture was then nitrogen-treated at 60 ° C. for one hour überschleiert. The reaction mixture turned yellowish and also milky-cloudy, the latter through the water of reaction released.

The mixture was then heated to 120 ° C. After a further 20 min the reflux condenser replaced by a descending condenser and the nitrogen flow strengthened. The mixture was stirred for a further 40 min at 120 ° C. with further stirring leave, then 60 min at 140 ° C. The approach cleared as a result of the water discharge gradually resumed, but retained a yellowish to amber appearance.

Example 6

The paint binders prepared according to the above application examples (according to Example 4 - soybean oil acetoacetate, according to Example 5 - soybean oil enamine) were mixed with a hexafunctional urethane acrylate (Ebecryl 1290, manufacturer UCB) and optionally with a basic catalyst (0.45% DBU = 1,8-diazabi-cyclo- [5.4.0] -undec-7- en) or / and a small amount of solvent (butyl acetate) combined (data in percent by mass):

The systems were applied to glass and sheet steel (Q-Panel R-36) and baked for 30 min at 120 ° C and at 150 ° C (dry layer thickness: approx. 50 µm). The pendulum hardness / pendulum damping according to König, the cupping, the cross cut adhesion on steel (after adhesive tape tear) and the resistance to an ethanol-water mixture (1: 1) over 16 h were evaluated. The pendulum hardness values are given below:

The flexibility (cupping values on steel) were consistently very high (7.0-8.5 mm). The cross-cut values on the steel were generally 1.

Example 7

35 percent by weight of an acetoacetate based on linseed oil, 56 percent by weight of one Rapeseed oil epoxy acrylates (produced by adding acrylic acid to epoxidized Rapeseed oil) and 9% of a freshly prepared, 5% solution of DBU in butyl acetate were mixed intensely. Application, curing and testing were carried out analogously Example 6.

The pendulum hardness on glass was 24 s (after curing at 120 ° C) or 43 s (150 ° C). The resistance to ethanol + water (1: 1) was rated 3 or 4 rated.

Claims (9)

1. Curable preparations
which contain at least one prepolymer (binder), which is obtained by reacting at least one vegetable oil-based polyol, the polyols - while largely maintaining the triglyceride structure - by opening and / or hydrolysis of the oxirane rings of epoxidized vegetable oils or directly from the reaction mixture of Reaction of vegetable oils with peroxycarboxylic acids or with hydrogen peroxide in the presence of carboxylic acids and immediately following ring opening and / or hydrolysis are obtained and serve as a starting point for subsequent steps in which they
either
are reacted with reaction products (adducts) which have been prepared from at least one diisocyanate and at least one hydroxy-functional acrylate or methacrylate to give vegetable oil-urethane (meth) acrylates
or
be reacted with esters of acetoacetic acid or with diketene to give vegetable oil acetoacetates
or
by further reaction of the vegetable oil acetoacetates with primary or secondary amines or with ammonia to form enamine-functionalized vegetable oil derivatives. 2. Curable preparations according to claim 1, which contain at least one vegetable oil Contain urethane (meth) acrylate. 3. Curable preparations according to claim 2, in which at least one vegetable oil Epoxy acrylate is used with.   4. Curable preparations according to claim 1, which contain at least one vegetable oil Acetoacetate according to claim 1 and / or at least one enamine functionalized Vegetable oil derivative according to claim 1 together with at least one Contain (meth) acrylate oligomer and / or (meth) acrylate monomer. 5. Curable preparations according to claim 4, which is a basic catalyst contain. 6. Curable preparations according to claim 4, in which the stoichiometric Relationship between the acetoacetate groups and / or enamine groups and the (Meth) acrylate groups is 1: 1. 7. Curable preparations according to claim 4, which are at least one as acrylate Vegetable oil urethane (meth) acrylate according to claim 1 or / and at least one Vegetable oil epoxy acrylate included. 8. A process for the preparation of curable preparations, characterized in that polyols from vegetable oils serve as the starting base, the polyols - while largely maintaining the triglyceride structure - from epoxidized vegetable oils by opening and / or hydrolysis of the oxirane rings or directly from the reaction mixture of the reaction of Vegetable oils with peroxycarboxylic acids or with hydrogen peroxide in the presence of carboxylic acids and immediately following ring opening and / or hydrolysis are produced and in subsequent steps

• a) the polyols with reaction products (adducts), which have been prepared from at least one diisocyanate and at least one hydroxy-functional acrylate or methacrylate, are further converted to vegetable oil-urethane (meth) acrylates or
• b) the polyols are converted to vegetable oil acetoacetates, which takes place with esters of acetoacetic acid or with diketene or
• c) the vegetable oil acetoacetates mentioned under b) are further reacted with primary or secondary amines or with ammonia to give vegetable oil derivatives which contain aminocrotonate groups (enamine groups).

9. A method for producing curable preparations according to claim 8, characterized in that used for the ring opening reaction Mixtures 30 to 80 mass percent formic acid and 20 to 70 mass percent Contain water.