Curable polymer compositions containing aldimines, polyisocyanates and compounds having activated methylene groups

Abstract

The invention relates to a curable composition comprising at least one aldimine L having aldimine groups of formula (I), optionally at least one polyol, at least one polyisocyanate, and at least one compound V having activated methylene groups of formula (II), wherein, based on the total composition, the ratio of the number of isocyanate groups to the sum of the number of aldimine groups plus hydroxyl groups is at least 0.9, and wherein the ratio of the number of activated methylene groups of formula (II) to the number of aldimine groups of formula (I) is at least 1. The composition is particularly suitable as a resilient coating having high strength, as a toughened coating having a particularly low tendency to form bubbles, or as a toughened adhesive. The composition cures using easily accessible aldimines derived from volatile aldehydes such as benzaldehyde, without odours, to form a high-quality polymer having a high tear-growth resistance.

Description

[0001] Curable polymer compositions containing aldimines, polyisocyanates and compounds with activated methylene groups

[0002] Technical area

[0003] The invention relates to curable compositions containing an aldimine, a polyisocyanate and a compound with activated methylene groups, as well as their use as elastic to viscoelastic coating or adhesive.

[0004] State of the art

[0005] Typical polyurethane coatings and adhesives consist of a polyol component and an isocyanate component, which are mixed and applied for the application. The curing reaction (urethane formation) is typically catalyzed by a tertiary amine and / or an organometallic compound. Particularly in coating applications, the challenge is that the curing material comes into intensive contact with ambient moisture due to the thin layer thickness and large surface area. Moisture can react with isocyanate groups in competition with the polyols, causing blistering and curing problems due to incomplete crosslinking.This can be improved by the use of more selective metal catalysts, although mercury-based catalysts cannot be used for toxicity reasons and complex compounds of bismuth, zinc or zirconium are difficult to use due to their high activity and high sensitivity to hydrolysis.

[0006] Furthermore, improvements in the moisture sensitivity of such polyurethane coatings can be achieved by incorporating an amine hardener into the polyol component. However, in their free form, most amine hardeners are too reactive and cause application difficulties, for example, due to inhomogeneities during mixing, excessively short open times, or in the adhesion build-up of an adhesive due to insufficient wetting of the substrate surface. To improve this, amine hardeners can be used in blocked, hydrolytically activated form, as so-called latent hardeners, for example as ketimines or aldimines. However, these release a ketone or aldehyde upon curing, which causes an undesirable odor and emissions or remains as a plasticizer in the cured composition, where it can significantly reduce the strength of the cured composition or cause problems with migration, exudation, or substrate contamination.

[0007] US 2015 / 0259465 describes compositions with a polyol and an isocyanate component, which additionally contain polyaldimines and special metal catalysts. Small amounts of metal catalysts with acetoacetate ligands can also be used. This does not resolve the problems of odor and / or plasticizing and migration effects caused by the released aldehydes.

[0008] WO 2022 / 219148 describes two-component anti-corrosive coatings containing a polyisocyanate, a polyol, and a special aldimine. The problems with plasticizing and migration effects caused by the released aldehydes are not resolved.

[0009] US 5,288,804 describes curable compositions containing polyacetoacetates and aldimines. They do not contain polyisocyanates and do not form elastic polymers, as is typical for polyurethanes.

[0010] WO 2017 / 044726 describes coatings, particularly anti-corrosive coatings, in which polyacetoacetates are cured with polyisocyanates. This also does not produce elastic polymers, as is typical for polyurethanes.

[0011] Description of the invention

[0012] The object of the invention is to provide a polymer composition which can be applied without problems and with a sufficiently long open time, which cures without blistering, odors, emissions or plasticizing releasers and which is suitable as a coating or adhesive.

[0013] This object is achieved with a curable composition as described in claim 1. The composition comprises at least one aldimine L having aldimine groups of the formula (I), optionally at least one polyol, at least one polyisocyanate and at least one compound V having activated methylene groups of the formula (II), in particular cyanoacetate, acetoacetate or malonate groups. Surprisingly, the aldimine L is activated by the compound V such that the aldimine groups are available for reaction with the polyisocyanate and urea bonds are formed. Surprisingly, no aldimine hydrolysis takes place, i.e. no moisture is required to activate the aldimine groups and make them accessible for reaction with isocyanate groups. Furthermore, apparently no aldehyde is released, because even with aldimines based on volatile aldehydes such as benzaldehyde, no aldehyde odor is detectable during curing.It can be assumed that during curing, an adduct of compound V and the aldehyde residue remains in the cured composition, with no odor emissions, plasticizer effects, or migration effects being observed. The composition according to the invention enables the use of aldimines derived from widely available, inexpensive aldehydes, such as benzaldehyde in particular, without the undesirable odor problem occurring. Surprisingly, the composition according to the invention not only cures odorlessly, but also exhibits a significantly reduced tendency to blistering and / or particularly good mechanical properties, in particular higher strength and hardness and higher tear resistance while maintaining good extensibility.

[0014] The curable composition according to the invention enables elastic coatings with high strength and high extensibility, tough, elastic, high-strength coatings with a particularly low tendency to blistering, and tough, elastic adhesives with good phase segregation and a particularly low glass transition temperature, making the mechanical properties of such adhesives particularly dependent on the prevailing temperature over a wide temperature range. This facilitates the use of such adhesives for load-bearing bonds on vehicles, for example, which are exposed to large temperature fluctuations during use.

[0015] Further aspects of the invention are the subject of further independent claims. Particularly preferred embodiments of the invention are the subject of the dependent claims.

[0016] Ways to implement the invention

[0017] The invention relates to a curable composition comprising - at least one aldimine L having aldimine groups of the formula (I),

[0018] — N^Z (0 where Z is an organic radical with 1 to 25 C atoms,

[0019] - optionally at least one polyol,

[0020] - at least one polyisocyanate, and

[0021] - at least one compound V having activated methylene groups of formula (II), where Y is a radical of the formula ■ __ CN , — C— R , ---C— OR 1 or

[0022] O II C— O— -, R represents a monovalent hydrocarbon radical with 1 to 10

[0023] C atoms and R 1represents an alkyl radical having 1 to 6 C atoms, wherein, based on the total composition, the ratio of the number of isocyanate groups to the sum of the number of aldimine groups plus hydroxyl groups is at least 0.9 and the ratio of the number of activated methylene groups of the formula (II) to the number of aldimine groups of the formula (I) is at least 1.

[0024] A dashed line in the formulas in this document represents the bond between a substituent and the corresponding molecular residue. Substance names beginning with "poly", such as polyisocyanate or polyol, refer to substances that formally contain two or more of the functional groups mentioned in their name per molecule.

[0025] The term “molecular weight” refers to the molar mass (in grams per mole) of a molecule or a moiety of a molecule. The term “average molecular weight” refers to the number average molecular weight (M n) a polydisperse mixture of oligomeric or polymeric molecules or molecular residues. It is determined by gel permeation chromatography (GPC) using polystyrene as a standard.

[0026] A composition is described as “storage-stable” if it can be stored at room temperature in a suitable container for a prolonged period, typically for at least three months up to six months or more, without its application or use properties being changed by storage to an extent relevant to its use.

[0027] The "NCO content" refers to the content of isocyanate groups in weight percent. "Room temperature" refers to a temperature of 23 °C.

[0028] All industry standards and norms mentioned in this document refer to the versions valid at the time of filing the initial application. Percentages by weight (wt%) refer to the mass fraction of a component of a composition or molecule relative to the entire composition or molecule, unless otherwise specified. The terms "mass" and "weight" are used synonymously in this document.

[0029] Preferably, the aldimine L has two to three aldimine groups of formula (I).

[0030] Preferably, the aldimine L has an aldimine equivalent weight, or in the case of an oligomeric or polymeric aldimine L average aldimine equivalent weight, of 110 to 2,500 g / eq.

[0031] In particular, the aldimine L has two to three aldimine groups of formula (I) and an aldimine equivalent weight, or in the case of an oligomeric or polymeric aldimine L average aldimine equivalent weight, of 110 to 2,500 g / eq.

[0032] Z preferably represents an aliphatic hydrocarbon radical having 3 to 11 C atoms bonded via a primary or secondary C atom or an aromatic or heteroaromatic five- or six-membered ring which is optionally substituted and / or fused and comprises a total of 4 to 25 C atoms, in particular an aromatic or heteroaromatic five- or six-membered ring which is optionally substituted and / or fused and comprises a total of 4 to 25 C atoms.Insbesondere ist Z ausgewählt aus der Liste bestehend aus 1 -Propyl, 2-Propyl, 1- Butyl, 1 -Pentyl, 1 -Heptyl, 3-Heptyl, 1 -Undecyl, Phenyl, 2-M ethyl phenyl, 3-Methyl- phenyl, 4-Methylphenyl, 4-Ethylphenyl, 4-lsopropylphenyl, 4-tert-Butylphenyl, 4- C -14-Alkylphenyl, 2,5-Dimethylphenyl, 2-Methoxyphenyl, 3-M ethoxy phenyl, 4-Me- thoxyphenyl, 2-Ethoxyphenyl, 3-Ethoxyphenyl, 4-Ethoxyphenyl, 4-Propoxyphenyl, 4-lsopropoxyphenyl, 4-Butoxyphenyl, 4-Pentoxyphenyl, 4-Decyloxyphenyl, 4-Do- decyloxyphenyl, 2,3-Dimethoxyphenyl, 2,4-Dimethoxyphenyl, 2,5-Dimethoxyphe- nyl, 3,4-Dimethoxyphenyl, 3,5-Dimethoxyphenyl, 2,4,6-Trimethylphenyl, 2,4,5-Tri- methoxyphenyl, 2,4,6-Trimethoxyphenyl, 3,4,5-Trimethoxyphenyl, 4-Methoxy- carbonylphenyl, 4-Ethoxycarbonylphenyl, 3-Nitrophenyl, 1 -Naphthyl, 2-Naphthyl, 2-Furyl, 5-Methyl-2-furyl, Thiophen, Pyridin, Pyrrol und Chinolin.

[0033] Of these, preference is given to phenyl, the isomeric methylphenyls, 4-Cw-14-alkylphenyl, 4-methoxyphenyl, 3,4-dimethoxyphenyl, 4-methoxycarbonylphenyl, 4-ethoxycarbonylphenyl, 3-nitrophenyl, 5-methyl-2-furyl or 2-furyl.

[0034] Most preferably, Z is phenyl. Such aldimines are derived from benzaldehyde. They are particularly easily accessible and enable particularly fast and reliable curing.

[0035] Aldimines derived from volatile aldehydes such as benzaldehyde produce a strong, unpleasant odor when used as latent curing agents in compositions containing isocyanate groups. This severely limits the applicability of such compositions, as the odor is present during application and persists long afterward. Surprisingly, the composition according to the invention does not produce any aldehyde odor, which is particularly advantageous because the composition can be used without restriction even in odor-sensitive applications, for example, in building interiors or in automobiles.

[0036] Preferred aldimine L are aldimines of formula (III a) or formula (III b), where n stands for 2 or 3,

[0037] G 1 for a di- or trivalent polyoxyalkylene radical with an average

[0038] Molecular weight Mn from 800 to 6'000 g / mol,

[0039] G 2 represents an n-valent organic radical having 2 to 25 C atoms, and Z has the meanings already mentioned.

[0040] In a preferred embodiment of the invention, the aldimine L is an aldimine of formula (III a), where n stands for 2 or 3, G 1 represents a di- or trivalent polyoxyalkylene radical having an average molecular weight Mn of 800 to 6,000 g / mol and Z has the meanings already mentioned.

[0041] An aldimine of formula (III a) is typically derived from a polyoxyalkylenediamine or triamine and an aldehyde of formula aus we |chen it is obtainable by a condensation reaction.

[0042] Preferred polyoxyalkylenediamines or triamines are polyoxypropylenediamines or triamines, in particular Jeffamine® D-2000, Jeffamine® D-4000 or Jeffamine® T-5000 (all from Huntsman), or corresponding types from BASF or Nitroil.

[0043] In particular, an aldimine of formula (III a) is selected from the list consisting of N,N'-dibenzylidenepolyoxypropylenediamines and N,N',N"-tribenzylidenepolyoxypropylenediamines and the analogous aldimines derived from tolualdehyde, a 4-C10-i4-alkylbenzaldehyde mixture, 4-methoxybenzaldehyde, methyl 4-formylbenzoate, ethyl 4-formylbenzoate, 3-nitrobenzaldehyde and furfural instead of benzaldehyde.

[0044] A curable composition containing an aldimine of formula (III a) can be formulated entirely without polyol. Upon curing, a polyurea is formed. This can be used, for example, to obtain coatings with high resistance to heat, moisture, and abrasion.

[0045] In a further preferred embodiment of the invention, the aldimine L is an aldimine of the formula (III b), where n stands for 2 or 3, G 2 represents an n-valent organic radical having 2 to 25 C atoms and Z has the meanings already mentioned.

[0046] G is preferred 2 for a divalent hydrocarbon radical having 2 to 15 C atoms, in particular 5 to 15 C atoms, or for a di- or trivalent polyoxyalkylene radical having an average molecular weight M n from 160 to 500 g / mol.

[0047] The aldimine of formula (III b) is typically derived from a primary amine and an aldehyde of formula O' Z aus which it is obtainable by a condensation reaction.

[0048] Preferred primary amines are commercially available aliphatic or cycloaliphatic primary amines, in particular selected from the list consisting of 1,2-ethanediamine, 1,2-propanediamine, 1,3-propanediamine, 1,4-butanediamine, 1,5-pentanediamine, 2,2-dimethyl-1,3-propanediamine, 1,3-pentanediamine (DAMP), 1,6-hexanediamine, 1,5-diamino-2-methylpentane (MPMD), 1,7-heptanediamine, 1,8-octanediamine, 2,5-dimethyl-1,6-hexanediamine, 1,9-nonanediamine, 2,2(4),4-trimethyl-1,6-hexanediamine (TMD), 1 ,10-decanediamine, 1,11-undecanediamine, 2-butyl-2-ethyl-1,5-pentanediamine (C11-neodiamine), 1,12-dodecanediamine, 1,2-diaminocyclohexane, 1,3-diaminocyclohexane, 1,4-diaminocyclohexane, 1 ,3-bis(aminomethyl)cyclohexane, 1,4-bis(aminomethyl)cyclohexane, 1,3-bis(aminomethyl)benzene (MXDA), isophoronediamine (IPDA), 2(4)-methyl-1,3-diaminocyclohexane, bis(4-aminocyclohexyl)methane, 2,5(6)-Bis(aminomethyl)bicyclo[2.2.1]heptane (NBDA), 3(4),8(9)-Bis(ami- nomethyl)tricyclo[5.2.1 .0 2 ' 6]decane (TCD-diamine), 4,9-dioxadodecane-1 , 12-diamine, 4,7,10-trioxatridecane-1 ,13-diamine, polyoxypropylenediamines with an average molecular weight M n from 200 to 500 g / mol and polyoxypropylenetriamines with an average molecular weight M n from 300 to 500 g / mol.

[0049] Preferred polyoxypropylene di- or triamines are Jeffamine® D-230, Jeffamine® D-400 or Jeffamine® T-403 (all from Huntsman), as well as equivalent grades from BASF or Nitroil.

[0050] As an aldehyde of the formula bevorzugt sind Butanal, Isobutyraldehyd, Valer- aldehyd, Hexanal, Octanal, 2-Ethylhexanal, Dodecanal, Benzaldehyd, 2-Tolual- dehyd, 3-Tolualdehyd, 4-Tolualdehyd, 4-Ethylbenzaldehyd, 4-lsopropyl-benzalde- hyd, 4-tert-Butylbenzaldehyd, 4-Cio-i4-Alkylbenzaldehyd, 2,5-Dimethylbenzalde- hyd, 2-Methoxybenzaldehyd, 3-Methoxybenzaldehyd, 4-Methoxybenzaldehyd, 2- Ethoxybenzaldehyd, 3-Ethoxybenzaldehyd, 4-Ethoxybenzaldehyd, 4-Propoxy- benzaldehyd, 4-lsopropoxybenzaldehyd, 4-Butoxybenzaldehyd, 4-Pentoxybenz- aldehyd, 4-Decyloxybenzaldehyd, 4-Dodecyloxybenzaldehyd, 2,3-Dimethoxy- benzaldehyd, 2,4-Dimethoxybenzaldehyd, 2,5-Dimethoxybenzaldehyd, 3,4-Dime- thoxybenzaldehyd, 3,5-Dimethoxybenzaldehyd, 2,4,6-T rimethylbenzaldehyd, 2,4,5-T rimethoxybenzaldehyd, 2,4,6-T rimethoxybenzaldehyd, 3,4,5-T rimethoxy- benzaldehyd, 4-Formylbenzoesäuremethylester, 4-Formylbenzoesäureethylester, 3-Nitrobenzaldehyd, 1-Naphthaldehyd, 2-Naphthaldehyd, Furfural oder 5-Methyl- furfural.

[0051] Of these, aromatic or heteroaromatic aldehydes are preferred. Particular preference is given to benzaldehyde, the isomeric tolualdehydes, a 4-C-14-alkylbenzaldehyde mixture, 4-methoxybenzaldehyde, 3,4-dimethoxybenzaldehyde, methyl 4-formylbenzoate, ethyl 4-formylbenzoate, 3-nitrobenzaldehyde, or furfural.

[0052] Benzaldehyde is most preferred.

[0053] Aldimines of formula (III b) derived from aromatic aldehydes, such as benzaldehyde in particular, sometimes exhibit a marked tendency to crystallize. Preferred aldimines of formula (III b) are those which, as such or as mixtures with one another, are permanently liquid at room temperature without the addition of solvents or diluents. Such aldimines enable compositions with low emissions.

[0054] Particularly preferred is the aldimine of formula (III b) selected from the list consisting of N,N'-dibenzylidene-1,5-pentanediamine, N,N'-dibenzylidene-1,6-hexanediamine, N,N'-dibenzylidene-2-methyl-1,5-pentanediamine, N,N'-dibenzylidene-2,2(4),4-trimethyl-1,6-hexanediamine, N,N'-dibenzylidene-1,3-bis(aminomethyl)cyclohexane, N,N'-dibenzylidene-1,3-bis(aminomethyl)benzene, N,N'-dibenzylideneisophoronediamine, N,N'-dibenzylidene-4,4'-methylene-bis(cyclohexylamine), N,N'-dibenzylidene-polyoxypropylenediamines with medium molecular weight M n from 350 to 750 g / mol and N,N',N"-tribenzylidenepolyoxypropylenetriamines with medium molecular weight M n from 450 to 700 g / mol, as well as the analogous aldimines derived from tolualdehyde, a 4-Cio-i4-alkylbenzaldehyde mixture, 4-methoxybenzaldehyde, 4-formylbenzoic acid methyl ester, 4-formylbenzoic acid ethyl ester, 3-nitrobenzaldehyde and furfural instead of benzaldehyde.

[0055] Of these, preferred are N,N'-dibenzylidene-1,5-pentanediamine, N,N'-dibenzylidene-2-methyl-1,5-pentanediamine, N,N'-dibenzylidene-1,6-hexanediamine, N,N'-dibenzylidene-2,2(4),4-trimethyl-1,6-hexanediamine, N,N'-dibenzylidenepolyoxypropylenediamines with medium molecular weight M n from 350 to 700 g / mol or N,N'-bis(4-C-14-alkylbenzylidene)isophoronediamine. In a preferred embodiment of the invention, the curable composition contains at least one polyol P having an OH number of 14 to 280 mg KOH / g, preferably 28 to 112 mg KOH / g.

[0056] The polyol P preferably has an average molecular weight M n from 400 to 10,000 g / mol, in particular 1,000 to 6,000 g / mol.

[0057] The polyol P preferably has an average OH functionality in the range from 1.6 to 3, particularly preferably 1.8 to 3, in particular 2.2 to 3.

[0058] The polyol P preferably contains at least some primary hydroxyl groups. Such polyols are particularly reactive with isocyanates.

[0059] Preferably, the polyol P is liquid at room temperature.

[0060] Commercially available polyols are suitable as Polyol P, in particular

[0061] - polyether polyols, in particular polyoxyalkylene diols and / or polyoxyalkylene triols, wherein triols are preferably started on 1,1,1-trimethylolpropane or glycerol, as well as polyether polyols with polymer particles dispersed therein, in particular those with styrene-acrylonitrile particles (SAN) or polyurea or polyhydrazodicarbonamide particles (PHD),

[0062] - Polyester polyols, in particular from the polycondensation of hydroxycarboxylic acids or lactones or the polycondensation of aliphatic and / or aromatic polycarboxylic acids with di- or polyhydric alcohols, or esterification products of dimer or trimer fatty acids,

[0063] - polycarbonate polyols,

[0064] - polyetherpolyesterpolyols,

[0065] - polyacrylate or polymethacrylate polyols,

[0066] - Polyhydroxyfunctional fats or oils, in particular natural fats, oils or derivatives thereof, in particular reaction products of castor oil,

[0067] - Polyhydrocarbon polyols, in particular hydroxy-functional polyolefins, polyisobutylenes or polyisoprenes, furthermore hydroxy-functional ethylene-propylene copolymers, ethylene-butylene copolymers or ethylene-propylene-diene copolymers, as produced, for example, by Kraton Polymers, furthermore hydroxy-functional polymers of dienes, in particular of 1,3-butadiene, furthermore hydroxy-functional copolymers of dienes and vinyl monomers such as styrene, acrylonitrile, vinyl chloride, vinyl acetate, vinyl alcohol, isobutylene or isoprene, and hydrogenated hydroxy-functional polymers or copolymers of dienes.

[0068] Polyether polyols or polyester polyols are preferred.

[0069] Polyether polyols in particular enable high elasticity over a wide temperature range, while polyester polyols enable particularly high strength.

[0070] Particularly preferred polyether polyols are polyoxypropylene polyols, ethylene oxide-terminated polyoxypropylene polyols or polyether polyols with polymer particles dispersed therein, in particular those with styrene-acrylonitrile particles (SAN) or polyurea or polyhydrazodicarbonamide particles (PHD).

[0071] Particularly preferred are ethylene oxide-terminated polyoxypropylene triols or ethylene oxide-terminated polyoxypropylene triols containing styrene-acrylonitrile particles (SAN) dispersed therein.

[0072] Also preferred are polyether polyols with a low unsaturation content (so-called "low monol" and "ultra low monol" polyols), in particular less than 0.02 mEq / g, preferably less than 0.01 mEq / g.

[0073] Particularly preferred polyester polyols are reaction products of castor oil, such as Setathane® D 1150 (from Allnex), or amorphous saturated polyester diols or triols, in particular from the reaction of dicarboxylic acids such as in particular succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid or dodecanedicarboxylic acid, with alcohols such as in particular 1,2-ethanediol, diethylene glycol, 1,2-propanediol, 1,3-propanediol, 2-methyl-1,3-propanediol, dipropylene glycol, 1,4-butanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, 1,3-cyclohexanedimethanol, 1,4-cyclo- hexanedimethanol, trimethylolpropane, or glycerol. If at least one aldimine of the formula (III b) is present as aldimine L, the curable composition preferably contains at least one polyol P or at least one aldimine of the formula (III a), in particular at least one polyol P.

[0074] The weight ratio between aldimines L, in particular aldimines of formula (III b), and polyols P is preferably in the range from 2 / 98 to 50 / 50, particularly preferably 3 / 97 to 40 / 60, in particular 4 / 96 to 30 / 70. Such a curable composition has a sufficiently long processing time and high strength with good extensibility after curing.

[0075] The curable composition further contains at least one polyisocyanate.

[0076] The polyisocyanate preferably has an NCO content based on the polyisocyanate of 8 to 35% by weight, preferably 10 to 33% by weight.

[0077] The polyisocyanate preferably has an NCO functionality or average NCO functionality of 2.1 to 4.0.

[0078] Preferred polyisocyanates are oligomers or derivatives of commercially available diisocyanates, such as in particular 1,5-pentane diisocyanate (PDI), 1,6-hexane diisocyanate (HDI), isophorone diisocyanate (IPDI), perhydro-2,4(6)-toluene diisocyanate (HeTDI), perhydro-4,4'-diphenylmethane diisocyanate (H12MDI), 2,2(4),4-trimethyl-1,6-hexane diisocyanate (TMDI), cyclohexane-1,3-diisocyanate, cyclohexane-1,4-diisocyanate, 1,3-bis(isocyanatomethyl)cyclohexane, 1,4-bis(isocyanatomethyl)cyclohexane, m-xylene diisocyanate, p-xylene diisocyanate, 2,4(6)-toluene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), 1,4-Phenylene diisocyanate (PDI) or naphthalene-1,5-diisocyanate (NDI), as well as so-called polymeric diphenylmethane diisocyanate (polymeric MDI or pMDI), which is a room temperature liquid mixture of MDI and MDI homologues with more than two isocyanate-substituted benzene rings, each of which may contain a proportion of reaction products with polyols.

[0079] Polyisocyanates that contain a proportion of reaction products with polyols can also be referred to as "quasi-prepolymers." Polyether polyols with an average molecular weight M are particularly suitable for this purpose. n from 300 to 2,000 g / mol, in particular selected from poly(oxy-1,2-ethylene)diols, poly(oxy-1,2-ethylene)diols containing ethylene oxide units, ethoxylated and / or propoxylated 1,1,1-trimethylolpropane and ethoxylated and / or propoxylated glycerol.

[0080] The polyisocyanate is particularly preferably selected from oligomers and derivatives of HDI, IPDI, TDI and MDI that are liquid at room temperature, and polymeric MDI (pMDI), which may each contain reaction products with polyols.

[0081] Particularly preferred are polymeric MDI and oligomers containing uretdione, isocyanurate, or iminooxadiazinedione groups, or various of these groups, as well as derivatives containing ester, urea, urethane, biuret, allophanate, carbodiimide, uretonimine, or oxadiazinetrione groups, or various of these groups. In practice, such polyisocyanates usually represent mixtures of substances with different degrees of oligomerization and / or chemical structures.

[0082] Particularly preferred are mixtures of MDI and MDI homologues (polymeric MDI or pMDI) which are liquid at room temperature, HDI biurets such as Desmodur® N 100 or N 3200 (from Covestro), Tolonate® HDB or HDB-LV (from Vencorex) or Duranate® 24A-100 (from Asahi Kasei), HDI isocyanurates such as Desmodur® N 3300, N 3600 or N 3790 BA (all from Covestro), Tolonate® HDT, HDT-LV or HDT-LV2 (from Vencorex), Duranate® TPA-100 or THA-100 (from Asahi Kasei) or Coronate® HX (from Nippon Polyurethane), HDI uretdiones such as Desmodur® N 3400 (from Covestro), HDI iminooxadiazinediones such as Desmodur® XP 2410 (from Covestro), HDI allophanates such as Basonat BA grades (BASF), TDI oligomers such as Desmodur® IL (from Covestro), or mixed isocyanurates based on TDI / HDI such as Desmodur® HL (from Covestro), each of which may contain reaction products with polyols. Based on the total composition, the ratio of the number of isocyanate groups to the sum of the number of aldimine groups plus hydroxyl groups is at least 0.9.

[0083] In this case, all isocyanate groups contained in the composition are related to the sum of all aldimine groups contained in the composition plus all hydroxyl groups contained in the composition.

[0084] Hydroxyl groups originate in particular from polyols P, and optionally from other polyols, in particular chain extenders.

[0085] A preferred ratio of the number of isocyanate groups to the sum of the number of aldimine groups plus hydroxyl groups is from 0.9 to 1.2, in particular from 1 to 1.1.

[0086] Such a composition cures to a polymer of high strength and good ductility.

[0087] The curable composition further contains at least one compound V having activated methylene groups of the formula (II), oo

[0088] II II1where Y is a radical of the formula __ -CN , ---C— R , ---C— OR or stands.

[0089] Preferably, the methylene groups of formula (II) are covalently bonded in compound V. In particular, the methylene groups of formula (II) are not present as a ligand on a metal atom.

[0090] R is preferably an alkyl radical having 1 to 6 carbon atoms or phenyl, particularly preferably methyl, ethyl, propyl, isopropyl, butyl, or phenyl. Most preferably, R is methyl.

[0091] Preferably R 1 is methyl, ethyl, or tert-butyl, particularly preferably ethyl or tert-butyl, in particular ethyl. Compound V is preferably liquid at room temperature. In particular, it has a viscosity at 20 °C of 0.01 to 50 Pa s, more preferably 0.01 to 25 Pa s, particularly preferably 0.01 to 10 Pa s, in particular 0.02 to 5 Pa s, measured using a cone-plate viscometer with a cone diameter of 10 mm, cone angle of 1°, cone tip-to-plate distance of 0.05 mm, and a shear rate of 10 s. -1, for viscosities of less than 0.5 Pa s with a cone diameter of 50 mm. Such a connection enables compositions that are easy to process at ambient temperature without the addition of solvents or thinners.

[0092] The compound V preferably contains one to six activated methylene groups of the formula (II), particularly preferably two to four, in particular two to three, activated methylene groups of the formula (II).

[0093] Preferably, the compound V has a molecular weight, or in the case of an oligomeric or polymeric compound V average molecular weight M n , from 100 to 10,000 g / mol, preferably 196 to 5,000 g / mol, particularly preferably 240 to 2,500 g / mol, in particular 240 to 1,500 g / mol.

[0094] Preferably, the compound V has, with respect to the activated methylene groups of the formula (II), an equivalent weight, or in the case of an oligomeric or polymeric compound V, an average equivalent weight, of 100 to 2,100 g / eq, preferably 114 to 600 g / eq, in particular 114 to 400 g / eq.

[0095] Preferably, the compound V has, with respect to the activated methylene groups of the formula (II), a functionality, or in the case of an oligomeric or polymeric compound V, an average functionality, of 1 to 4, preferably 1.5 to 3.5, in particular 1.8 to 3.

[0096] In particular, the compound V has, with respect to the activated methylene groups of the formula (II), an equivalent weight, or in the case of an oligomeric or polymeric compound V average equivalent weight, of 100 to 2,100 g / eq, preferably 114 to 600 g / eq, in particular 114 to 400 g, and a functionality, or in the case of an oligomeric or polymeric compound V average functionality, of 1 to 4, preferably 1.5 to 3.5, in particular 1.8 to 3.

[0097] Preferably, based on the total composition, the ratio of the number of activated methylene groups of the formula (II) to the number of aldimine groups of the formula (I) is in the range from 1 to 4, particularly preferably 1.2 to 3, in particular 1.5 to 2.5.

[0098] Preferably, the compound V is obtained from the transesterification of at least one hydroxyl-containing compound with at least one compound of the formula (IV), 1where Y 1 for a remainder of the formula " _CN , ---C— R or —C— OR and R and R 1 have the meanings already described.

[0099] The transesterification is preferably carried out at a temperature of 50 to 150 °C with distillative removal of the released alcohol R 1 OH and optionally fragmentation products thereof, optionally under vacuum and optionally in the presence of catalysts.

[0100] It is also possible to prepare a compound V containing cyanoacetate groups by esterification of cyanoacetic acid with at least one compound containing hydroxyl groups.

[0101] It is also possible to prepare a compound V containing acetoacetate groups by reacting the hydroxyl group-containing compound on which compound V is based with diketene or the adduct of diketene with acetone (= 2,2,6-trimethyl-4H-1,3-dioxin-4-one), whereby in the case of the acetone-diketene adduct

[0102] Acetone is released. It is also possible to produce a compound V containing malonate groups by esterifying malonic acid with at least one hydroxyl-containing compound.

[0103] Particularly suitable compounds of formula (IV) are methyl cyanoacetate, ethyl cyanoacetate, tert-butyl cyanoacetate, methyl acetoacetate, ethyl acetoacetate, tert-butyl acetoacetate, ethyl 3-oxohexanoate, ethyl benzoyl acetate, dimethyl malonate, diethyl malonate, diisopropyl malonate or di-(tert-butyl) malonate.

[0104] Preferred are ethyl cyanoacetate or tert-butyl cyanoacetate, ethyl acetoacetate or tert-butyl acetoacetate, and malonic acid diethyl ester.

[0105] Preferred hydroxyl-containing compounds are commercially available OH-functional compounds or polymers, such as in particular 1,2-ethanediol, diethylene glycol, triethylene glycol, 1,2-propanediol, dipropylene glycol, tripropylene glycol, 1,3-propanediol, 1,4-butanediol, 1,2-butanediol, 2-methyl-1,3-propanediol, 1,5-pentanediol,

[0106] 1,2-pentanediol, neopentyl glycol, 2-methyl-1,4-butanediol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, 1,8-octanediol, 2-ethyl-1,3-hexanediol, 1,10-decanediol, 1,12-dodecanediol, polytetrahydrofurandiol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, 1,1,1-trimethylolethane, 1,1,1-trimethylolpropane, glycerol, pentaerythritol, ethoxylated or especially propoxylated glycerol, ethoxylated or especially propoxylated 1,1,1-trimethylolpropane, poly(oxy-1,2-propylene)diols with medium Molecular weight of 400 to 4,000 g / mol, EO-terminated poly(oxy-1,2-propylene)diols with average molecular weight of 1,000 to 4,000 g / mol, poly(oxy-

[0107] 1,2-propylene)triols with an average molecular weight of 400 to 6,000 g / mol, EO-terminated poly(oxy-1,2-propylene)triols with an average molecular weight of 3,000 to 6,000 g / mol, di- or trimer fatty acid-based polyester polyols with an average molecular weight of 1,000 to 3,000 g / mol, castor oil, derivatives of castor oil or hydroxylated vegetable oils.

[0108] In a preferred embodiment of the invention, Y is a radical of the formula ■ _-CN and the activated methylene groups of formula (II) are therefore cyanoacetate groups. Preferably, a compound V having cyanoacetate groups is selected from the list consisting of ethyl cyanoacetate, 2-methyl-1,3-propanediol dicyanoacetate, neopentylglycol dicyanoacetate, 1,6-hexanediol dicyanoacetate, 3-methyl-1,5-pentanediol dicyanoacetate, 2-ethyl-1,3-hexanediol dicyanoacetate, the tricyanoacetate of ethoxylated and / or propoxylated 1,1,1-trimethylolpropane, the tricyanoacetate of ethoxylated and / or propoxylated glycerol, poly(oxy-1,2-propylene)diol bis(cyanoacetate), ethylene oxide units-containing poly(oxy-1,2-propylene)diol bis(cyanoacetate), dimer fatty acid-based polyesterdiol bis(cyanoacetate) and trimer fatty acid-based Polyestertriol-tris(cyanoacetate).

[0109] In a particularly preferred embodiment of the invention, Y in the O II

[0110] Formula (II) for a radical of the formula --_C— R , where R preferably represents methyl and the activated methylene groups of formula (II) are thus acetoacetate groups.

[0111] Preferably, a compound V having acetoacetate groups is selected from the list consisting of ethyl acetoacetate, 1,2-propanediol diacetoacetate, dipropylene glycol diacetoacetate, tripropylene glycol diacetoacetate, 1,3-propanediol diacetoacetate, 1,4-butanediol diacetoacetate, 2-methyl-1,3-propanediol diacetoacetate, 1,5-pentanediol diacetoacetate, neopentyl glycol diacetoacetate, 1,6-hexanediol diacetoacetate, 3-methyl-1,5-pentanediol diacetoacetate, 2-ethyl-1,3-hexanediol diacetoacetate, glycerol diacetoacetate, glycerol triacetoacetate, 1,1,1-trimethylolethane diacetoacetate, 1,1,1-trimethylolethane triacetoacetate, 1,1,1-trimethylolpropane diacetoacetate, 1,1,1-trimethylolpropane triacetoacetate, the triacetoacetate of propoxylated and / or ethoxylated 1,1,1-trimethylolpropane, the triacetoacetate of propoxylated and / or ethoxylated glycerol, poly(oxy-1,2-propylene)diol bis(acetoacetate), poly(oxy-1,2-propylene)diol bis(acetoacetate) containing ethylene oxide units,Castor oil bis(acetoacetate), castor oil tris(acetoacetate), dimer fatty acid-based polyesterdiol bis(acetoacetate) and trimer fatty acid-based polyestertriol tris(acetoacetate). Of these, preference is given to 1,2-propanediol diacetoacetate, dipropylene glycol diacetoacetate, 2-methyl-1,3-propanediol diacetoacetate, neopentyl glycol diacetoacetate, 1,6-hexanediol diacetoacetate, 3-methyl-1,5-pentanediol diacetoacetate, 2-ethyl-1,3-hexanediol diacetoacetate, glycerol diacetoacetate, glycerol triacetoacetate, 1,1,1-trimethylolpropane diacetoacetate, 1,1,1-trimethylolpropane triacetoacetate, a triacetoacetate of propoxylated 1,1,1-trimethylolpropane with average molecular weight M, n from 500 to 1,000 g / mol or a poly(oxy-1,2-propylene)diol bis(acetoacetate) with medium molecular weight M n from 550 to 5,000 g / mol.

[0112] O

[0113] In a further embodiment, Y is a radical of the formula ---C 11 — OR 1O II or ---C— O--- and the activated methylene groups of formula (II) are thus malonate groups.

[0114] Preferably, a compound V having malonate groups is selected from the list consisting of diethyl malonate, diisopropyl malonate, 1,2-ethanediol bis(ethylmalonate), 1,2-propanediol bis(ethylmalonate), 1,3-propanediol bis(ethylmalonate), 1,4-butanediol bis(ethylmalonate), 2-methyl-1,3-propanediol bis(ethylmalonate), neopentyl glycol bis(ethylmalonate), 1,6-hexanediol bis(ethylmalonate), 3-methyl-1,5-pentanediol bis(ethylmalonate), 2-ethyl-1,3-hexanediol bis(ethylmalonate), 1,4-cyclohexanedimethanol bis(ethylmalonate), diethylene glycol bis(ethylmalonate), di- propylene glycol bis(ethylmalonate), glycerol tris(ethylmalonate), 1,1,1-trimethylolpropane tris(ethylmalonate), castor oil tris(ethylmalonate), poly(oxy-1,2-propylene)diol bis(ethylmalonate) with medium molecular weight M nfrom 500 to 2,000 g / mol, propoxylated 1,1,1-trimethylolpropane with three ethyl malonate end groups and an average molecular weight M n from 650 to 2,500 g / mol, corresponding oligomeric compounds of these reaction products, as well as polyester diols containing malonate groups from the reaction of diols such as 1,6-hexanediol and 1,4-cyclohexanedimethanol with malonic acid and diethyl malonate and optionally adipic acid or diethyl adipic acid. Suitable compounds containing malonate groups are also commercially available, in particular as Acure® 510-200 (from Allnex).

[0115] The curable composition preferably contains at least one further component selected from crosslinkers, catalysts, drying agents, fillers, and pigments. The curable composition preferably contains several such components.

[0116] Preferred crosslinkers are so-called chain extenders or low molecular weight polyols, such as in particular 1,3-propanediol, 1,4-butanediol, 1,2-butanediol, 2-methyl-1,3-propanediol, 1,5-pentanediol, neopentyl glycol, 2-methyl-1,4-butanediol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, and ethoxylated and / or propoxylated glycerol or ethoxylated and / or propoxylated 1,1,1-trimethylolpropane, each with an OH number of 300 to 650 mg KOH / g.

[0117] Such crosslinkers are preferably used in combination with a polyol P.

[0118] Preferred catalysts are

[0119] - metal compounds, in particular organotin(IV) compounds such as in particular dibutyltin diacetate, dibutyltin dilaurate, dibutyltin dichloride, dibutyltin diacetylacetonate, dimethyltin dilaurate, dioctyltin diacetate, dioctyltin dilaurate or dioctyltin diacetylacetonate, as well as complex compounds of bismuth(III) or zirconium(IV), in particular with ligands selected from alcoholates, carboxylates, 1,3-diketonates, oxinate, 1,3-ketoesterates and 1,3-ketoamidates, and / or

[0120] - Amingruppen-haltige Verbindungen wie insbesondere Triethylamin, Tripropylamin, Tributylamin, Tri(2-ethylhexyl)amin, N,N-Dimethylisopropylamin, N-Ethyl- diisopropylamin, N,N-Dimethylcyclohexylamin, N,N-Dimethyl-Ci2-i4-alkylamin, N,N-Dimethylbenzylamin, a-Methylbenzyldimethylamin, N-Methylpiperidin, N,N'- Dimethylpiperazin, N-Methyl-N'-dimethylaminoethylpiperazin, Bis-(dimethyl- aminoethyljpiperazin, 1 ,4-Diazabicyclo[2.2.2]octan (DABCO), 1 ,3,5-Trimethyl- hexahydrotriazin, 1 ,3-Bis(dimethylaminopropyl)harnstoff, Bis(2-dimethylamino- ethyl)ether, Tris(2-(2-methoxyethoxy)ethyl)amin, N-Methylmorpholin, N-Ethyl- morpholin oder 2,2'-Dimorpholinodiethylether (DMDEE).

[0121] Metal compounds catalyze the reaction of isocyanate groups and are preferred for curable compositions containing polyisocyanates with aliphatic isocyanate groups. Compounds containing amine groups catalyze both the reaction of isocyanate groups and the reaction of compound V with aldimines L.

[0122] In the event that the curable composition contains acids, preferably at least one base, in particular a compound containing amine groups, is additionally contained in such an amount that the curable composition as a whole is not acidic.

[0123] The curable composition preferably contains at least one zeolite, also called molecular sieve, as a drying agent.

[0124] Preferred fillers are ground or precipitated calcium carbonates, optionally coated with fatty acids, especially stearates, barites (heavy spars), quartz flours, quartz sands, dolomites, wollastonites, kaolins, calcined kaolins, phyllosilicates such as mica or talc, zeolites, aluminum hydroxides, magnesium hydroxides, silicas including highly dispersed silicas from pyrolysis processes, industrially produced carbon blacks, graphite, ground fillers from agricultural sources such as olive kernel flour or nutshell flour, metal powders, for example, aluminum, copper, iron, silver, or steel, PVC powders, or hollow spheres. Calcium carbonates, barites, quartz flours, quartz sands, or kaolins are particularly preferred.

[0125] Preferred pigments are titanium dioxide, chromium oxide, iron oxides or organic pigments.

[0126] The curable composition may additionally contain other components, in particular: - polymers containing isocyanate groups,

[0127] - other crosslinkers such as oxazolidines, ketimines or other aldimines,

[0128] - dyes,

[0129] - fibres, in particular glass fibres, carbon fibres, metal fibres, ceramic fibres, hemp fibres, cellulose fibres or plastic fibres such as polyamide fibres or polyethylene fibres,

[0130] - Nanofillers or nanofibers such as graphene or carbon nanotubes,

[0131] - Plasticizers, in particular phthalates, in particular diisononyl phthalate (DINP), diisodecyl phthalate (DIDP) or di(2-propylheptyl)phthalate (DPHP), hydrogenated phthalates, in particular diisononyl 1,2-cyclohexanedicarboxylate (DINCH), terephthalates, in particular bis(2-ethylhexyl)terephthalate or diisononyl terephthalate (DINT), hydrogenated terephthalates, in particular bis(2-ethylhexyl)-1,4-cyclohexanedicarboxylate or diisononyl 1,4-cyclohexanedicarboxylate, isophthalates, trimellitates, adipates, in particular dioctyl adipate (DOA), azelates, sebacates, citrates, benzoates, glycol ethers, glycol esters, plasticizers with polyether structure, in particular poly(oxy-1,2-propylene) monols, diols or triols with blocked hydroxyl groups, in particular in in the form of acetyl groups, organic sulfonates or phosphates, in particular diphenyl cresyl phosphate (DPK), polybutenes, polyisobutenes or plasticizers derived from natural fats or oils, in particular epoxidized soy or linseed oil or rapeseed oil methyl ester,phthalates, hydrogenated phthalates, adipates or plasticizers with polyether structure are preferred,

[0132] - solvents,

[0133] - Rheology modifiers, in particular urea compounds, layered silicates such as bentonites, derivatives of castor oil, hydrogenated castor oil, polyamides, polyurethanes, pyrogenic silicas or hydrophobically modified polyoxyethylenes,

[0134] - other drying agents such as calcium oxide, highly reactive isocyanates such as p-tosyl isocyanate, mono-oxazolidines such as Incozol® 2 (from Incorez) or orthoesters,

[0135] - Adhesion promoters, in particular titanates or organoalkoxysilanes such as epoxysilanes, in particular 3-glycidoxypropyltrimethoxysilane or 3-glycidoxypropyltriethoxysilane, aminosilanes, iminosilanes, mercaptosilanes, vinylsilanes, (meth)acrylosilanes, carbamatosilanes, alkylsilanes, S-(alkylcarbonyl)mercaptosilanes or oligomeric forms of these silanes,

[0136] - flame-retardant substances, in particular the fillers already mentioned, aluminium hydroxide or magnesium hydroxide, organic phosphoric acid esters, ammonium polyphosphates, melamine or derivatives thereof, boron compounds or antimony compounds;

[0137] - non-reactive thermoplastic polymers, in particular homo- or copolymers of unsaturated monomers, in particular from the group comprising ethylene, propylene, butylene, isobutylene, isoprene, styrene, vinyl acetate and alkyl (meth)acrylates, in particular polyethylenes (PE), polypropylenes (PP), polyisobutylenes, ethylene-vinyl acetate copolymers (EVA) and atactic poly-α-olefins (APAO);

[0138] - Modifiers such as hydrocarbon resins, natural or synthetic waxes or bitumen;

[0139] - Additives, in particular wetting agents, flow control agents, defoamers, deaerators, stabilizers against oxidation, heat, light or UV radiation or biocides; as well as other substances commonly used in curable compositions.

[0140] It may be useful to dry certain substances chemically or physically before mixing them into the composition.

[0141] The curable composition preferably contains less than 10% by weight, more preferably less than 5% by weight, and especially less than 1% by weight, of volatile organic compounds (VOCs) with a boiling point at atmospheric pressure of less than 250°C, based on the total composition. Such a composition causes particularly low emissions.

[0142] The curable composition is preferably formulated as a multi-component system, in particular as a two- or three-component system. The curable composition preferably comprises a component K1 and a component K2, as well as optionally a component K3, each of which is individually stable and stored in separate containers.

[0143] Preferably, the ingredients are distributed among the components in such a way that either

[0144] - Aldimines L and optionally polyols are part of component K1, polyisocyanates are part of component K2 and compounds V are either part of component K2 or are present as a separate component K3, or that

[0145] - Compounds V and optionally polyols are part of component K1 and aldimines L and polyisocyanates are part of component K2.

[0146] Additional ingredients in the composition may be present as components K1 and / or K2 and / or K3. Care should be taken to ensure that the components are formulated in such a way that each component is individually stable when stored in a suitable container.

[0147] In a preferred embodiment of the invention, the curable composition comprises a component K1, a component K2 and optionally a component K3, wherein component K1 contains at least one aldimine of the formula (III a), component K2 contains at least one polyisocyanate and compound V is either a constituent of component K2 or is present as a separate component K3. Preferred polyisocyanates are those containing aliphatic isocyanate groups, in particular trimers of HDI. Such a curable composition cures to form a polyurea and enables particularly high-quality coatings with particularly high strength and resistance to UV, heat, moisture and abrasion.

[0148] In a further preferred embodiment of the invention, the curable composition comprises a component K1 and a component K2, wherein component K1 contains at least one aldimine of the formula (III a) and at least one polyisocyanate and component K2 contains at least one compound V.

[0149] In a further preferred embodiment of the invention, the curable composition comprises a component K1, a component K2, and optionally a component K3, wherein component K1 contains at least one polyol P and at least one aldimine of formula (III b), component K2 contains at least one polyisocyanate, and compound V is either a constituent of component K2 or is present as a separate component K3. Such a composition is particularly cost-effective and enables high strengths and good extensibility.

[0150] In a further preferred embodiment of the invention, the curable composition comprises a component K1 and a component K2, wherein component K1 contains at least one polyol P and at least one compound V and component K2 contains at least one polyisocyanate and at least one aldimine of the formula (III b).

[0151] The consistency of the components is preferably such that they can be easily mixed together under ambient conditions using simple methods. Liquid or pasty components are particularly suitable for this purpose. The components preferably have a similar viscosity and / or rheology. Such components are particularly easy to mix with each other.

[0152] Components K1, K2 and, if applicable, K3 of the curable composition are prepared separately. The ingredients of each component are mixed together to form a macroscopically homogeneous liquid or paste. Components K1, K2 and, if applicable, K3 are each stored in a separate container. Suitable containers include, in particular, drums, containers, hobbocks, buckets, canisters, tins, bags, tubular bags, cartridges or tubes. To use the curable composition, all ingredients, in particular components K1, K2 and, if applicable, K3, are mixed together shortly before or during application. In the case of three components, the mixing sequence is arbitrary. All three components can be mixed at the same time, or two of the three components can be mixed first and then the other component mixed in.Preferably, aldimines L and compounds V are not premixed separately, but rather mixed in the presence of the polyisocyanate. The mixing ratio is selected such that the ratio of the number of aldimine groups to the number of isocyanate groups and the ratio of the number of activated methylene groups of formula (II) to the number of aldimine groups are within the range according to the invention.

[0153] Mixing is preferably carried out at ambient temperature, in particular at a temperature of -5 to 50 °C, preferably 0 to 40 °C, in particular 5 to 35 °C.

[0154] If the components are mixed together prior to application, care must be taken to ensure that the time between mixing and application is not too long, as otherwise the reaction and the associated increase in viscosity may cause problems such as insufficient flow or slow or incomplete adhesion to the substrate. In particular, the open time of the composition during application should not be exceeded.

[0155] The "open time" refers to the period of time between mixing the components and the end of a composition suitable for processing. The open time can also be referred to as the "processing time." The time until a tack-free surface forms is a measure of the open time.

[0156] When the ingredients or components are mixed, the composition begins to harden due to the chemical reaction that occurs.

[0157] Based on the observed effects, it can be assumed that the activated methylene groups of formula (II) react with aldimine groups of formula (I), thereby activating them, i.e., making them reactive towards isocyanate groups. The reaction of the activated aldimine groups with the isocyanate groups leads to crosslinking of the isocyanate-containing polymer with the formation of urea groups. Unlike the hydrolytic activation of aldimine groups, the aldehyde is not released but remains permanently in the composition in derivatized form, presumably as an adduct with compound V or its derivatives. Furthermore, isocyanate groups can react with existing moisture or, particularly in the case of aromatic isocyanate groups, with methylene groups of formula (II).

[0158] Curing preferably takes place at ambient temperature, in particular at a temperature of -5 to 50 °C, preferably 0 to 40 °C.

[0159] The curing reaction proceeds reliably without blistering or odor. The aldehyde derivatives remaining in the composition show no signs of migration, nor do they appear to have a plasticizing effect on the cured composition.

[0160] Another object of the invention is the cured composition obtained from the curable composition after mixing the ingredients or components and subsequent curing.

[0161] Preferably, the cured composition has high strength, good ductility and high tear resistance.

[0162] The cured composition preferably has a tensile strength of at least 5 MPa, in particular at least 7 MPa, and - for particularly hard compositions with a Shore hardness of more than 60 D - in particular at least 15 MPa, determined according to DIN EN 53504 on dumbbell-shaped test specimens (length 75 mm, web length 30 mm, web width 4 mm, thickness 2 mm) at a tensile speed of 200 mm / min. The cured composition preferably has an elongation at break of at least 50%, in particular at least 100%, determined according to DIN EN 53504 on dumbbell-shaped test specimens (length 75 mm, web length 30 mm, web width 4 mm, thickness 2 mm) at a tensile speed of 200 mm / min.

[0163] The cured composition preferably has a tear resistance of at least 7 N / mm, preferably at least 10 N / mm, and for particularly hard compositions with a Shore hardness of more than 60 D of at least 25 N / mm, in particular at least 50 N / mm, determined according to DIN ISO 34-1 method B (angular test specimen) with a sample thickness of 2 mm and a tensile speed of 500 mm / min.

[0164] The curable composition is suitable for a wide range of applications. It is used in particular as a coating, adhesive, sealant, casting resin, or filler, especially as an elastic to viscoelastic coating or adhesive.

[0165] A further object of the invention is the use of the curable composition as an elastic or viscoelastic coating or adhesive, wherein the ingredients or components are mixed together and the mixed composition is applied in the liquid state to at least one substrate.

[0166] Suitable substrates include:

[0167] - Glass, glass ceramics, concrete, mortar, cement screed, fiber cement, brick, tile, plaster or natural stones such as granite or marble;

[0168] - Repair or levelling compounds based on PCC (polymer-modified cement mortar) or ECO (epoxy resin-modified cement mortar);

[0169] - Metals or alloys such as aluminum, iron, steel, copper, other non-ferrous metals, including surface-treated metals or alloys such as galvanized or chrome-plated metals;

[0170] - Asphalt or bitumen; - Leather, textiles, paper, wood, wood materials bonded with resins, for example phenolic, melamine or epoxy resins, resin-textile composites or other so-called polymer composites;

[0171] - Plastics such as rigid and soft PVC, polycarbonate, polystyrene, polyester, polyamide, PMMA, ABS, SAN, epoxy resins, phenolic resins, PUR, POM, TPO, PE, PP, EPM or EPDM, each untreated or surface-treated, for example by means of plasma, corona or flames;

[0172] - fiber-reinforced plastics, such as carbon fiber-reinforced plastics (CFRP), glass fiber-reinforced plastics (GRP), natural fiber-reinforced plastics (NFRP) and sheet molding compounds (SMC);

[0173] - Insulating materials, in particular foams, in particular EPS, XPS, PUR, PIR, aerogel or foamed glass (foam glass), or fibres made of rock wool or glass wool,

[0174] - coated or painted substrates, in particular painted tiles, painted concrete, powder-coated metals or alloys or painted sheets;

[0175] - Coatings, paints or varnishes.

[0176] If necessary, the substrates may be pretreated before application, in particular by physical and / or chemical cleaning processes or the application of an activator or a primer.

[0177] Two similar or two different substrates can be bonded and / or sealed.

[0178] An article is obtained from the use of the curable composition. This article may be a building or a part thereof, in particular a building or civil engineering structure, a bridge, a roof, a staircase, or a facade, or it may be an industrial or consumer good, in particular a window, a pipe, a wind turbine rotor blade, a household appliance, or a means of transport, such as, in particular, an automobile, a bus, a truck, a rail vehicle, a ship, an aircraft, or a helicopter, or an attachment thereof. Examples

[0179] The following are exemplary embodiments intended to further illustrate the described invention. Of course, the invention is not limited to these described exemplary embodiments.

[0180] The “standard climate” (“NK”) is defined as a temperature of 23±1 °C and a relative humidity of 50±5%.

[0181] Unless otherwise stated, the chemicals used were from Merck.

[0182] The viscosity was measured on a thermostatted cone-plate viscometer Rheotec RC30 (cone diameter 10 mm, cone angle 1 °, cone tip-plate distance 0.05 mm, shear rate 10 s -1 ) measured. Viscosities of less than 0.5 Pa s were measured with a cone diameter of 50 mm and a shear rate of 100 s' 1 measured.

[0183] Infrared spectra (FT-IR) were measured as undiluted films on a Thermo Scientific Nicolet iS5 FT-IR instrument equipped with a horizontal diamond crystal ATR measurement unit.

[0184] Production of aldimines:

[0185] Aldimine A-1 :

[0186] 212.2 g (2 mol) of benzaldehyde were initially charged under a nitrogen atmosphere, admixed with 158.3 g (1 mol) of 2,2(4),4-trimethyl-1,6-hexanediamine (Vestamin® TMD, from Evonik) with vigorous stirring, and the volatile components were subsequently removed at 80 °C and a vacuum of 10 mbar. This gave 333.6 g of N,N'-dibenzylidene-2,2(4),4-trimethyl-1,6-hexanediamine as a clear, yellowish liquid with an amine number of 335 mg KOH / g and an aldimine equivalent weight of 167.3 g / eq.

[0187] Aldimine A-2:

[0188] 106.1 g (1 mol) of benzaldehyde was placed under a nitrogen atmosphere, mixed with 124.0 g (1 mol NH2) of polyoxypropylenediamine (Jeffamine® D-230, from Huntsman) with vigorous stirring, and the volatile components were then removed at 80 °C and a vacuum of 10 mbar. This yielded 210.7 g of a clear, yellowish liquid with a viscosity at 20 °C of 0.34 Pa s, an amine number of 265 mg KOH / g, and an aldimine equivalent weight of 212 g / eq. Aldimine A-3:

[0189] 50.00 g of aldehyde-1 (0.17 mol aldehyde groups) were placed under a nitrogen atmosphere, mixed with 13.93 g (0.08 mol) of isophoronediamine (Vestamin® IPD, from Evonik) with vigorous stirring, and the volatile components were subsequently removed at 80 °C and a vacuum of 10 mbar. A clear, yellowish liquid with an amine number of 144 mg KOH / g and an aldimine equivalent weight of 390 g / eq was obtained.

[0190] As aldehyde-1, a reaction mixture containing predominantly branched 4-(Cio-14-alkyl)benzaldehydes with an average aldehyde equivalent weight of 290 g / eq was used, obtained from HF-BF3-catalyzed formylation of Cio-14-alkylbenzene.

[0191] Aldimine A-4:

[0192] 212.2 g (2 mol) of benzaldehyde were initially charged under a nitrogen atmosphere, mixed with a mixture of 51.1 g (0.5 mol) of 1,5-pentanediamine (from Cathay Biotech) and 58.1 g (0.5 mol) of 1,6-hexanediamine with vigorous stirring, and the volatile components were then removed at 80 °C and a vacuum of 10 mbar. This yielded 289.8 g of a clear, yellowish liquid with a viscosity at 20 °C of 0.09 Pa s, an amine number of 393 mg KOH / g, and an aldimine equivalent weight of 142.7 g / eq.

[0193] Preparation of compounds with activated methylene groups:

[0194] Compound B-1 :

[0195] 134.2 g (1 mol) of 1,1,1-trimethylolpropane was treated with 522.1 g (3.3 mol) of tert-butyl acetoacetate and reacted at a temperature of 140 °C under vacuum until the broad OH band in the range of 3,300 to 3,600 cm was observed in the FT-IR. -1had disappeared and no more volatiles were separated. 367.3 g of 1,1,1-trimethylolpropane triacetoacetate were obtained as a clear, yellowish liquid with a viscosity at 20 °C of 0.27 Pa s and a theoretical acetoacetate equivalent weight of 129 g / eq. Compound B-2:

[0196] 146.1 g (1 mol) of isosorbide was treated with 348.0 g (2.2 mol) of tert-butylacetoacetate and reacted at a temperature of 140 °C under vacuum until the broad OH band in the range of 3,300 to 3,600 cm -1 had disappeared and no more volatile substances were separated. 310.6 g of isosorbide diacetoacetate were obtained as a clear, yellowish liquid with a viscosity at 20 °C of 0.91 Pa s and a theoretical acetoacetate equivalent weight of

[0197] 157 g / eq.

[0198] Connection B-3:

[0199] 92.1 g (1 mol) of glycerol (= 1,2,3-trihydroxypropane) was treated with 506.2 g (3.2 mol) of tert-butylacetoacetate and reacted at a temperature of 140 °C under vacuum until the broad OH band in the range of 3,300 to 3,600 cm' was observed in the FT-IR. 1 had disappeared and no more volatiles were separated. 327.6 g of glycerol triacetoacetate were obtained as a clear, yellowish liquid with a viscosity at 20 °C of 0.12 Pa s and a theoretical acetoacetate equivalent weight of 114.7 g / eq.

[0200] Connection B-4:

[0201] 104.1 g (1 mol) of neopentyl glycol (= 2,2-dimethyl-1 ,3-propanediol) was treated with 348.0 g (2.2 mol) of ethyl acetoacetate and 0.45 g of tetra-n-butyl titanate and reacted at a temperature of 140 °C under vacuum until the broad OH band in the range of 3,300 to 3,600 cm -1had disappeared and no more volatile substances were separated. 254.1 g of neopentyl glycol diacetoacetate were obtained as a clear, yellowish liquid with a viscosity at 20 °C of < 0.05 Pa s and a theoretical acetoacetate equivalent weight of

[0202] 136 g / eq. Other substances and abbreviations used:

[0203] Polyol-1 : Castor oil-based branched polyol (Setathane® D 1150,

[0204] OH number 156 mg KOH / g, from Allnex) Polyol-2: Trimethylolpropane-initiated polyoxypropylene triol (Desmophen® 4011 T, OH number 550 mg KOH / g, from Covestro)

[0205] Polyol-3: Ethylene oxide-terminated polyoxypropylene triol (Voranol® CP

[0206] 4755, OH number 35 mg KOH / g, from Dow)

[0207] Polyol-4: Ethylene oxide-terminated polyoxypropylene triol with 45 wt.% grafted SAN polymer (Lupranol® 4003 / 1, OH number 20 mg KOH / g, from BASF)

[0208] HDI trimer: T rimer of 1,6-hexane diisocyanate (Desmodur® N 3600,

[0209] 23 wt.% NCO, from Covestro) modified MDI: carbodiimide-modified diphenylmethane diisocyanate (Desmodur® VH 20 N, 24.5 wt.% NCO, from Covestro) polymeric MDI: diphenylmethane diisocyanate with polymeric components (Desmodur® VL, 31.5 wt.% NCO, from Covestro)

[0210] Production of curable compositions:

[0211] Examples Z-1 to Z-30:

[0212] For each example, the ingredients of the first component (K1) listed in Tables 1 to 4 were mixed in the specified amounts (in parts by weight) and stored in a sealed container.

[0213] Likewise, the ingredients of the second component (K2) were mixed in the amounts (in parts by weight) specified in Tables 1 to 4 and stored in a sealed container.

[0214] If present, the ingredient of the third component (K3) was used in the amount specified in Tables 1 to 4.

[0215] The components of each composition were then processed into a homogeneous liquid using the centrifugal mixer and tested as described below.

[0216] The gelling time (time between mixing the components and gelling) was determined by moving 10 g of the mixed composition with a spatula at regular intervals until the mass gelled.

[0217] To determine the mechanical properties, the composition was cast onto a PTFE-coated foil to form a 2 mm thick film. This film was cured by storage for 14 days under standard conditions. Several dumbbell-shaped test specimens (length 75 mm, web length 30 mm, web width 4 mm) were punched from the film and tested according to DIN EN 53504 at a tensile speed of 200 mm / min for maximum tensile strength, elongation at break, and 5% elastic modulus (between 0.5-5% elongation). Furthermore, several test specimens were punched out to determine tear resistance and tested according to DIN ISO 34-1, Method B (angular test specimen) at a tensile speed of 500 mm / min.

[0218] The Shore hardness was determined according to DIN 53505 on cylindrical test specimens (diameter 20 mm, thickness 5 mm) after a storage period of 14 days in standard climate.

[0219] Odor was assessed by nose-sniffing the freshly prepared films at a distance of 2 cm. "0" means no aldehyde odor was detectable. "+", "++", or "+++" indicate a slight, distinct, or intense aldehyde odor.

[0220] To determine the tendency to bubble formation, the freshly mixed composition was applied to a glass plate in a layer thickness of 500 μm. The plate was immediately stored for 24 hours in a climate chamber at 30 °C and 80% relative humidity, and then evaluated. "0" means no bubbles were present. "+", "++", or "+++" indicate few, some, or many bubbles were present, respectively.

[0221] During curing, a non-sticky, polymeric material was created.

[0222] The results are shown in Tables 1 to 4.

[0223] The examples marked with “(Ref.)” are comparative examples.

[0224]

[0225] Table 1 : Composition and properties of Z-1 to Z-6.

[0226] 1 Molecular sieve 3Ä 50 wt.% in castor oil

[0227] 2 Dibutyltin dilaurate 10% by weight in dioctyl adipate

[0228] 3 DABCO® 33-LV (from Evonik)

[0229] 4 Ratio of the number of activated methylene groups of formula (II) to the number of aldimine groups of formula (I)

[0230] Table 2: Composition and properties of 7.-7 to Z-15.

[0231] 1 Molecular sieve 3Ä 50 wt.% in castor oil

[0232] 2 Dibutyltin dilaurate 10% by weight in dioctyl adipate

[0233] 3 DABCO® 33-LV (from Evonik)

[0234] 4 Salicylic acid 5 wt.% in dioctyl adipate

[0235] 5 Ratio of the number of activated methylene groups of formula (II) to the number of aldimine groups of formula (I)

[0236] "nb" stands for "not determined"

[0237]

[0238] Table 3: Composition and properties of Z-16 to Z-21.

[0239] 1 Molecular sieve 3Ä 50 wt.% in Polyol-3

[0240] 2 Ratio of the number of activated methylene groups of formula (II) to the number of aldimine groups of formula (I)

[0241] "nb" stands for "not determined"

[0242] Table 4: Composition and properties of Z-22 to Z-30.

[0243] 1 Molecular sieve 3Ä 50 wt.% in castor oil

[0244] 2 Ratio of the number of activated methylene groups of formula (II) to the number of aldimine groups of formula (I)

[0245] "nb" stands for "not determined"

Claims

Patent claims: 1 . Curable composition comprising - at least one aldimine L with aldimine groups of formula (I), — N^Z 0) where Z is an organic radical with 1 to 25 C atoms, - optionally at least one polyol, - at least one polyisocyanate, and - at least one compound V with activated methylene groups of formula (II), oo II II where Y is a radical of the formula ■ __ CN , — C— R , ---C— OR 1 or O II C— O— -, R represents a monovalent hydrocarbon radical having 1 to 10 C atoms and R 1represents an alkyl radical having 1 to 6 C atoms, wherein, based on the total composition, the ratio of the number of isocyanate groups to the sum of the number of aldimine groups plus hydroxyl groups is at least 0.9 and the ratio of the number of activated methylene groups of the formula (II) to the number of aldimine groups of the formula (I) is at least 1.

2. Composition according to claim 1, characterized in that the aldimine L has two to three aldimine groups of the formula (I) and an aldimine equivalent weight, or in the case of an oligomeric or polymeric aldimine L average aldimine equivalent weight, of 110 to 2,500 g / eq.

3. Composition according to one of claims 1 or 2, characterized in that Z represents an aliphatic hydrocarbon radical having 3 to 11 C atoms bonded via a primary or secondary C atom or represents an aromatic or heteroaromatic five- or six-membered Ring, der gegebenenfalls substituiert und / oder anelliert ist und insgesamt 4 bis 25 C-Atome umfasst, steht, wobei Z insbesondere ausgewählt ist aus der Liste bestehend aus 1 -Propyl, 2-Propyl, 1 -Butyl, 1 -Pentyl, 1 -Heptyl, 3-Heptyl, 1 -Undecyl, Phenyl, 2-Methyl- phenyl, 3-Methylphenyl, 4-Methylphenyl, 4-Ethylphenyl, 4-lsopropylphenyl, 4- tert-Butylphenyl, 4-C -i4-Alkylphenyl, 2,5-Dimethylphenyl, 2-Methoxyphenyl, 3-Methoxyphenyl, 4-Methoxyphenyl, 2-Ethoxyphenyl, 3-Ethoxyphenyl, 4- Ethoxyphenyl, 4-Propoxyphenyl, 4-lsopropoxyphenyl, 4-Butoxyphenyl, 4- Pentoxyphenyl, 4-Decyloxyphenyl, 4-Dodecyloxyphenyl, 2,3-Dimethoxy- phenyl, 2,4-Dimethoxyphenyl, 2,5-Dimethoxyphenyl, 3,4-Dimethoxyphenyl, 3,5-Dimethoxyphenyl, 2,4,6-Trimethylphenyl, 2,4,5-Trimethoxyphenyl, 2,4,6- Trimethoxyphenyl, 3,4,5-Trimethoxyphenyl, 4-Methoxycarbonylphenyl, 4- Ethoxycarbonylphenyl, 3-Nitrophenyl, 1 -Naphthyl, 2-Naphthyl, 2-Furyl, 5- Methyl-2-furyl, Thiophen, Pyridin, Pyrrol und Chinolin.

4. Composition according to one of claims 1 to 3, characterized in that the aldimine L is an aldimine of formula (III a) or formula (III b), where n stands for 2 or 3, G 1 for a di- or trivalent polyoxyalkylene radical with an average molecular weight M n from 800 to 6,000 g / mol, and G 2 stands for an n-valent organic residue with 2 to 25 C atoms.

5. Composition according to one of claims 1 to 4, characterized in that at least one polyol P having an OH number of 14 to 280 mg KOH / g, preferably 28 to 112 mg KOH / g, is present.

6. Composition according to claim 5, characterized in that the weight ratio between aldimines L, in particular aldimines of the formula (III b), and polyols P is in the range from 2 / 98 to 50 / 50, preferably 3 / 97 to 40 / 60, in particular 4 / 96 to 30 / 70.

7. Composition according to one of claims 1 to 6, characterized in that the polyisocyanate has an NCO content based on the polyisocyanate of 8 to 35% by weight, preferably 10 to 33% by weight, wherein the polyisocyanate is selected in particular from oligomers and derivatives of 1,6-hexane diisocyanate, isophorone diisocyanate, 2,4(6)-toluene diisocyanate and diphenylmethane diisocyanate which are liquid at room temperature, and polymeric diphenylmethane diisocyanate, wherein these may each contain reaction products with polyols.

8. Composition according to one of claims 1 to 7, characterized in that the compound V has, with respect to the activated methylene groups of the formula (II), an equivalent weight, or in the case of an oligomeric or polymeric compound V average equivalent weight, of 100 to 2,100 g / eq, preferably 114 to 600 g / eq, in particular 114 to 400 g, and a functionality, or in the case of an oligomeric or polymeric compound V average functionality, of 1 to 4, preferably 1.5 to 3.5, in particular 1.8 to 3.

9. Composition according to one of claims 1 to 8, characterized in that, based on the total composition, the ratio of the number of activated methylene groups of the formula (II) to the number of aldimine groups of the formula (I) is in the range from 1 to 4, preferably 1.2 to 3, particularly preferably 1.5 to 2.

5.

10. Composition according to one of claims 1 to 9, characterized O II is characterized in that Y represents a radical of the formula C—R, where R preferably represents methyl and the activated methylene groups of the formula (II) are thus acetoacetate groups, where the compound V is in particular selected from the list consisting of ethyl acetoacetate, 1,2-propanediol diacetoacetate, dipropylene glycol diacetoacetate, tripropylene glycol diacetoacetate, 1,3-propanediol diacetoacetate, 1,4-butanediol diacetoacetate, 2-methyl-1,3-propanediol diacetoacetate, 1,5-pentanediol diacetoacetate, neopentyl glycol diacetoacetate, 1,6-hexanediol diacetoacetate, 3-methyl-1,5-pentanediol diacetoacetate, 2-ethyl-1,3-hexanediol diacetoacetate, glycerol diacetoacetate, glycerol triacetoacetate, 1 , 1 , 1 -Trimethylolethane diacetoacetate, 1 , 1 , 1 -Trimethylolethane triacetoacetate, 1 , 1 , 1 -Trimethylolpropane diacetoacetate, 1 ,1 ,1-Trimethylolpropane triacetoacetate, the triacetoacetate of propoxylated and / or ethoxylated 1 ,1 ,1-trimethylolpropane,the triacetoacetate of propoxylated and / or ethoxylated glycerin, poly(oxy-1,2-propylene)diol bis(acetoacetate), ethylene oxide-containing poly(oxy-1,2-propylene)diol bis(acetoacetate), castor oil bis(acetoacetate), castor oil tris(acetoacetate), dimer fatty acid-based polyesterdiol bis(acetoacetate) and trimer fatty acid-based polyestertriol tris(acetoacetate).

11. Composition according to one of claims 1 to 10, characterized in that at least one further component selected from crosslinkers, catalysts, drying agents, fillers and pigments is present.

12. Composition according to one of claims 1 to 11, characterized in that the composition comprises a component K1 and a component K2, and optionally a component K3, which are each storage-stable on their own and are stored in separate containers.

13. Composition according to claim 12, characterized in that either - Aldimines L and optionally polyols are components of component K1, polyisocyanates are components of component K2 and compounds V are either components of component K2 or are present as a separate component K3, or that - Compounds V and optionally polyols are part of component K1 and aldimines L and polyisocyanates are part of component K2.

14. Cured composition obtained from the curable composition according to any one of claims 1 to 13 after mixing the ingredients or components and subsequent curing.

15. Use of the curable composition according to any one of claims 1 to 13 as an elastic or viscoelastic coating or adhesive, wherein the ingredients or components are mixed together and the mixed composition is applied in the liquid or pasty state to at least one substrate.

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