Stabiliser for compositions containing isocyanate groups

Abstract

The invention relates to the use of at least one malonate of formula (I) as a stabiliser for storage stability in compositions containing isocyanate groups, and to a curable composition obtained from the use according to the invention. The malonate of formula (I) makes possible one-component elastic adhesives with very good storage stability, which adhere excellently to glass and ceramic substrates without pretreatment using primers. Such an adhesive is particularly suitable for bonding panes in the vehicle industry.

Description

[0001] Stabilizer for isocyanate group-containing compounds

[0002] Technical field

[0003] The invention relates to the use of stabilizers to increase the storage stability of isocyanate group-containing compositions, isocyanate group-containing compositions containing such stabilizers, and the use of the compositions as elastic adhesives and / or sealants.

[0004] State of the art

[0005] One-component, moisture-curing polyurethane compounds and their use as elastic adhesives, sealants, or coatings are well-known, particularly for bonding windows in the automotive industry. The storage stability of such compounds repeatedly presents a challenge. Typically, these compounds contain only a low concentration of isocyanate groups. Therefore, even small amounts of moisture or a slight tendency to form isocyanate oligomers can lead to premature cross-linking during storage in sealed containers. This manifests as an excessive increase in viscosity, eventually resulting in gelation of the compound.The storage stability of compositions with a low proportion of monomeric diisocyanates, as well as in the presence of organosilanes and / or organometallic catalysts such as dibutyltin dilaurate, especially in combination with amine catalysts such as 2,2'-dimorpholinyl diethyl ether, is particularly challenging. However, a particularly low content of monomeric diisocyanates is advantageous with regard to EHS classification, and the use of organosilanes in combination with organometallic catalysts enables particularly good adhesion properties, especially to glass or glass-ceramics, such as those found in windshields in the automotive industry. Diethyl malonate is known from the prior art as a stabilizer for the storage stability of isocyanate-containing compositions, for example from US 9,868,810 or US 11,859,109. Description of the invention.

[0006] The object of the present invention is to provide an elastic adhesive that exhibits good storage stability and adhesion properties and is suitable for bonding windshields in vehicles. Surprisingly, this object is achieved by using a malonate of formula (I) as a stabilizer for storage stability in isocyanate-containing compositions. The malonate of formula (I) enables the use of one-component, moisture-curing elastic adhesives with very good storage stability, which adhere excellently to common glass and ceramic substrates, particularly without pretreatment by means of a primer. In contrast, the diethyl malonate known from the prior art, when used instead of a malonate of formula (I), does improve the storage stability of such compositions, but the adhesion properties are significantly inferior, especially on certain ceramic substrates.

[0007] The use according to the invention enables the production of one-component polyurethane adhesives with good storage stability, excellent processability, in particular high sag resistance, low stringing, and a sufficiently long open time with rapid curing, as well as high strength and elasticity and excellent adhesion properties, even without pretreatment with a primer, especially on substrates commonly used in glass bonding such as glass or glass ceramics. These favorable properties are also achieved with non-hazardous adhesives based on isocyanate-containing polymers with a very low content of monomeric diisocyanates, especially those derived from particularly reactive aromatic diisocyanates such as diphenylmethane diisocyanate (MDI) or toluene diisocyanate (TDI).

[0008] Further aspects of the invention are the subject of further independent claims. Particularly preferred embodiments of the invention are the subject of dependent claims. Ways of carrying out the invention

[0009] The invention relates to the use of at least one malonate of formula (I) as a stabilizer for storage stability in isocyanate group-containing compositions, where

[0010] R 1 for a hydrocarbon residue, possibly containing ether groups, with 11 to 100 carbon atoms, and

[0011] R 2 for R 1 or for R 3 stands, where R 3 stands for a possibly branched alkyl group with 1 to 4 carbon atoms.

[0012] A composition is considered "storage-stable" if it can be stored at room temperature in a suitable container for an extended period, typically at least 3 months up to 6 months or more, without its application or performance characteristics changing to a degree relevant to its use. To assess storage stability, accelerated aging of the composition in a sealed container can be carried out for 7 or 14 days at 60 °C.

[0013] A functional group of the formula is called a "malonate group".

[0014] OO

[0015] -_-oX\XX -- denotes which is bonded to a C atom via the dashed line.

[0016] The term "molecular weight" refers to the molar mass (in grams per mole) of a molecule or molecular residue. The "mean molecular weight" is the number-average molecular weight (M) of the molecules. n) a polydisperse mixture of oligomeric or polymeric molecules or molecular residues. The average molecular weight M n is determined in particular by gel permeation chromatography (GPC) against polystyrene as a standard.

[0017] The "NCO content" refers to the percentage of isocyanate groups by weight relative to the entire polymer. A composition is described as "one-component" if all components are contained and stored in the same container.

[0018] A temperature of 23 °C is referred to as "room temperature".

[0019] All industry standards and norms mentioned in this document refer to the versions valid at the time of filing the initial application. Weight percent (wt%) denotes 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.

[0020] R is preferred 1 for a hydrocarbon residue with 11 to 20 C atoms, preferably 12 to 18 C atoms, or for a hydrocarbon residue containing ether groups with 11 to 100 C atoms, preferably 12 to 80 C atoms.

[0021] R is particularly preferred 1selected from the list consisting of undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl and octadecyl, wherein these alkyl groups are linear or branched, containing 3,6-dioxa-1-dodecyl, 3,6,9-trioxa-1-tridecyl and other monofunctional polyether residues, including repeating units selected from 1,2-ethyleneoxy, 1,2-propylenoxy, 1,3-propylenoxy and 1,4-butylenoxy.

[0022] The preferred monofunctional polyether residue is an alkanol-started poly(oxy-1,2-propylene)monol with an average molecular weight M. n from 300 to 2,000 g / mol, preferably 350 to 1,500 g / mol, in particular 500 to 1,000 g / mol, after removal of the hydroxyl group, where alkanol in particular means butanol.

[0023] The residue of a monofunctional polyether residue is also preferred.

[0024] Alkanol-started poly(oxy-1,2-ethylene)monols with a medium

[0025] Molecular weight M n from 300 to 2,000 g / mol, preferably 350 to 1,500 g / mol, in particular 500 to 1,000 g / mol, after removal of the hydroxyl group, where alkanol in particular means butanol.

[0026] R is preferred 1 for a linear or branched dodecyl, tridecyl, tetradecyl, pentadecyl or hexadecyl residue.

[0027] R is especially preferred 1 for a linear dodecyl residue.

[0028] Furthermore, R is particularly preferred 1 for a technical mixture of branched Ci2-14 alkyl residues.

[0029] Furthermore, R is particularly preferred 1 for a butanol-started poly(oxy-1,2-propylene) residue with a mean molecular weight M n from 500 to 1,000 g / mol.

[0030] Furthermore, R is particularly preferred 1for an alkanol-started poly(oxy-1,2-ethylene) residue with a mean molecular weight Mn of 300 to 500 g / mol.

[0031] R is preferred 2 for R 1 .

[0032] R is preferred 3 for ethyl or tert-butyl, especially for ethyl.

[0033] In a particularly preferred embodiment of the invention, the stabilizer comprises a mixture of malonates of formula (I), in which a portion of the residues R 2 for R 1 stands and part of the remains R 2 not for R 3 The following is particularly preferred: at least 10%, more preferably at least 20%, more preferably at least 40%, and in particular at least 60% of the residues R. 2 for R 1 .

[0034] Preferably, the malonate of formula (I) is used in such an amount that the isocyanate group-containing composition contains 0.3 to 15 meq, preferably 0.5 to 8 meq, in particular 1 to 5 meq, malonate groups from malonates of formula (I) per 100 parts by weight of the isocyanate group-containing composition.

[0035] Preferably, the malonate of formula (I) comprises a reaction product obtained from the transesterification of at least one malonate of formula (II) with at least one monoalcohol of formula (III) with removal of alcohol of formula R 3 -OH ,

[0036] R 1 — OH (Hl) where R 1 and R 3 which has the meanings already described.

[0037] Suitable malonates of formula (II) include dimethyl malonate, diethyl malonate, diisopropyl malonate, butylethyl malonate, tert-butylethyl malonate, or di-tert-butyl malonate. Diethyl malonate or di-tert-butyl malonate, especially diethyl malonate, is preferred as the malonate of formula (II).

[0038] Preferably as the monoalcohol of formula (III) is linear or branched undecanol, dodecanol, tridecanol, tetradecanol, pentadecanol, hexadecanol, heptadecanol or octadecanol, in particular linear dodecanol or a technical mixture of branched Ci2-14-alkanols.

[0039] A particularly suitable technical mixture of branched Ci2-14 alkanols is Exxal® 13 (from ExxonMobil).

[0040] A polyether monool, in particular an alkanol-started poly(oxy-1,2-propylene) monool with an average molecular weight M, is also preferred as the monoalcohol of formula (III). nfrom 500 to 1,500 g / mol, preferably 500 to 1,000 g / mol, where alkanol specifically refers to butanol.

[0041] A particularly suitable butanol-started poly(oxy-1,2-propylene)monol is Synalox® 100-20B (from Dow).

[0042] A further preferred monoalcohol of formula (III) is an alkanol-started poly(oxy-1,2-ethylene)monol with an average molecular weight M n of 300 to 750 g / mol, preferably 300 to 500 g / mol, where alkanol specifically refers to butanol. The transesterification preferably takes place at a temperature of 80 to 160 °C, particularly 100 to 150 °C, optionally in the presence of a suitable catalyst, preferably under vacuum and with distillation to remove the released alcohol R. 3 — OH .

[0043] The transesterification preferably takes place in a molar ratio of monoalcohol of formula (III) to malonate of formula (II) in the range of 1 to 2, preferably 1.2 to 2.0, more preferably 1.5 to 1.9, and particularly 1.7 to 1.9. Such a reaction product typically contains a mixture of malonates of formula (I) with R 2 = R 1 and malonates of formula (I) with R 2 = R 3 , and it contains particularly little unreacted monoalcohol of formula (III) and particularly little unreacted malonate of formula (II).

[0044] Such a reaction product is low in odor, non-volatile, and enables isocyanate group-containing compositions with good storage stability, high strength and elasticity, and surprisingly good adhesion properties.

[0045] In the case of a technical mixture of branched Ci2-14-alkanols and diethyl malonate in a molar ratio of 1.8:1 and complete transesterification, the reaction product essentially contains the following malonates (1a) and (1b) in a molar ratio of about 80 / 20.

[0046] The malonate of formula (I) is used as a stabilizer for storage stability in isocyanate group-containing compositions. Preferably, the isocyanate group-containing composition contains at least one isocyanate group-containing polymer, in particular with an NCO content based on the total polymer of 0.5 to 8 wt%, preferably 0.75 to 5 wt%, and in particular 1 to 3 wt%.

[0047] Preferably, the isocyanate-containing composition is a single-component, moisture-curing compound. All ingredients are mixed and packaged in a single, airtight container. Good storage stability is of central importance, ensuring that the composition can be used even after extended storage periods of 3 to 6 months or more without any loss of processability or final properties such as strength, elasticity, and adhesion. During application, the isocyanate-containing composition comes into contact with moisture from the air and from the substrates to which it is applied, thereby initiating the curing process.For particularly fast curing or when applying between moisture-proof substrates, additional moisture can be added, for example by mixing in a moisture-containing so-called booster component or by brushing or spraying the substrates or the applied composition with moisture.

[0048] It is also possible to use the malonate of formula (I) as a stabilizer in the isocyanate component of a two-component composition, wherein the isocyanate component contains, in particular, an isocyanate-group-containing polymer. Such a two-component composition comprises, in addition to the isocyanate component, another component which typically contains polyols, amines, and / or latent hardeners such as aldimines, ketimines, enamines, or oxazolidines. The two components are packaged separately and are stable for storage. They are mixed for application and curing, whereby the isocyanate groups react primarily with reactive groups from the other component, forming a crosslink. The malonate of formula (I) improves the storage stability of the isocyanate component.Another object of the invention is a curable isocyanate group-containing composition comprising at least one isocyanate group-containing polymer and, as a stabilizer for storage stability, at least one malonate of formula (I) as described above.

[0049] Preferably, the hardenable composition contains 0.3 to 15 meq, preferably 0.5 to 8 meq, in particular 1 to 5 meq, malonate groups from malonates of formula (I) in relation to the total composition.

[0050] Preferably, the isocyanate-containing polymer is liquid at room temperature. It is preferably low-viscosity and has a viscosity of 0.5 to 50 Pa s, preferably 1 to 30 Pa s, and particularly 1 to 20 Pa s, determined at 20 °C using a cone-plate viscometer with a cone diameter of 10 mm, a cone angle of 1°, and a cone-plate distance of 0.05 mm at a shear rate of 10 s'. 1 .

[0051] Preferably, the isocyanate-containing polymer has an NCO content of 0.5 to 8 wt% based on the total polymer, more preferably 0.75 to 5 wt%, and particularly 1 to 3 wt%. The NCO content is determined in particular by reacting the isocyanate groups with an excess of dibutylamine and back-titration of the unreacted dibutylamine with aqueous hydrochloric acid.

[0052] Preferably, the isocyanate group-containing polymer has a medium isocyanate functionality of 1.7 to 4.0, in particular 1.8 to 3.0.

[0053] Preferably, the isocyanate-containing polymer has a medium molecular weight M n from 1,000 to 20,000 g / mol, 2,000 to 15,000 g / mol, especially 4,000 to 10,000 g / mol.

[0054] Preferably, the isocyanate groups of the isocyanate-containing polymer are derived from at least one monomeric diisocyanate selected from the list consisting of 4,4'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, 1,6-hexane diisocyanate, isophorone diisocyanate, 4,4'-diisocyanatodicyclohexylmethane and 1-methyl-2,4(6)-diisocyanatocyclohexane.

[0055] Isocyanate groups derived from 4,4'-diphenylmethane diisocyanate or 2,4(6)-toluene diisocyanate, especially 4,4'-diphenylmethane diisocyanate, are particularly preferred. These isocyanate groups are highly reactive and therefore especially critical with regard to storage stability. In particular, 4,4'-diphenylmethane diisocyanate enables a particularly fast-curing composition with exceptionally high strength and elasticity.

[0056] The isocyanate group-containing polymer is preferably produced by reacting at least one monomeric diisocyanate with at least one polyol in a molar ratio NCO / OH of at least 1.3, preferably at least 1.5, in particular at least 1.8, preferably under exclusion of moisture at 20 to 160 °C, in particular 40 to 140 °C, optionally in the presence of a suitable catalyst.

[0057] A particularly preferred isocyanate-containing polymer has a monomeric diisocyanate content of less than 0.5 wt%, preferably less than 0.2 wt%, and particularly less than 0.1 wt%, based on the total polymer. This enables curable compositions with a monomeric diisocyanate content of less than 0.1 wt% based on the total composition. Such compositions have a favorable EHS classification and are particularly safe in use.

[0058] An isocyanate group-containing polymer with a particularly low content of monomeric diisocyanates is preferably produced with a molar NCO / OH ratio of 3 / 1 to 10 / 1, preferably 3 / 1 to 8 / 1, and subsequent removal of unreacted monomeric diisocyanate by distillation, preferably by thin-film distillation or short-path distillation, preferably under vacuum.

[0059] Suitable monomeric diisocyanates for the production of the isocyanate-containing polymer include commercially available aliphatic, cycloaliphatic, or aromatic diisocyanates such as 1,6-hexane diisocyanate (HDI), isophorone diisocyanate (IPDI), 4,4'-diisocyanatodicyclohexylmethane (H12MDI), 1-methyl-2,4(6)-diisocyanocyclohexane (HeTDI), 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), and diphenylmethane diisocyanate. (MDI), 1,4-phenylene diisocyanate (PDI) or naphthalene-1,5-diisocyanate (NDI).

[0060] Preferably the monomeric diisocyanate is selected from the list consisting of 4,4'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, 1,6-hexane diisocyanate, isophorone diisocyanate, 4,4'-diisocyanatodicyclohexylmethane and 1-methyl-2,4(6)-diisocyanatocyclohexane.

[0061] Suitable polyols for the production of the isocyanate-containing polymer are commercially available polyols or mixtures thereof, in particular

[0062] - 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),

[0063] - Polyester polyols, in particular from the polycondensation of hydroxycarboxylic acids or lactones or the polycondensation of aliphatic and / or aromatic polycarboxylic acids with dihydric or polyhydric alcohols, as well as polyester polyols containing dimer or trimer fatty acid esters,

[0064] - Polycarbonate polyols,

[0065] - Polyether polyester polyols

[0066] - Polyacrylate or polymethacrylate polyols,

[0067] - polyhydroxy functional fats or oils, for example natural fats and oils, especially castor oil; or polyols obtained by chemical modification of natural fats and oils – so-called oleochemical polyols,

[0068] - Polyhydrocarbon polyols, in particular hydroxy-functional polyolefins, polyisobutylenes or polyisoprenes, furthermore hydroxy-functional ethylene-propylene copolymers, ethylene-butylene copolymers or ethylene-propylene-diene copolymers, such as those produced 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, as well as hydrogenated hydroxy-functional polymers or copolymers of dienes.

[0069] Mixtures of polyols are particularly suitable.

[0070] Polyols with a medium OH functionality of 1.7 to 3 are preferred.

[0071] Preferred polyether polyols, polyester polyols, polycarbonate polyols, or polyacrylate polyols are preferred. Polyether polyols or polyester polyols, especially polyether polyols, are particularly preferred.

[0072] Preferably, polyether polyols with repeating units are selected from oxy-1,2-propylene, oxy-1,3-propylene, oxy-1,4-butylene, oxy-1,2-butylene and oxyphenylethylene, optionally including additional oxy-1,2-ethylene, in particular up to 25 wt% oxy-1,2-ethylene units based on the polyether polyol.

[0073] 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, are preferred.

[0074] Particularly preferred are polyether polyols with oxy-1,2-propylene repeat units, optionally with up to 25 wt%, based on the total weight of the polyether polyol, oxy-1,2-ethylene units at the chain ends (also called "ethylene oxide-terminated" or "EO-terminated" polyether polyols).

[0075] Particularly preferred are poly(oxy-1,2-propylene)diols or triols, optionally EO-terminated, with an OH number of 7 to 175 mg KOH / g, preferably 10 to 145 mg KOH / g, and particularly 14 to 112 mg KOH / g. Particularly preferred are poly(oxy-1,2-propylene)diols or triols, optionally EO-terminated, with an average molecular weight M. n from 1,000 to 12,000 g / mol, preferably 2,000 to 8,000 g / mol.

[0076] Particularly preferably, the curable composition contains at least one isocyanate group-containing polymer with polyether chains and an NCO content of 1 to 3 wt% based on the total polymer.

[0077] The curable composition may contain more than one isocyanate group-containing polymer.

[0078] A curable composition particularly suitable as a disc adhesive preferably contains, in addition to one or more isocyanate group-containing polymers with polyether chains and an NCO content of 1 to 3 wt% based on the total polymer, at least one further isocyanate group-containing polymer.

[0079] A further polymer containing isocyanate groups is particularly suitable if it is a polymer that is solid at room temperature and based on at least one semi-crystalline polyester polyol, whereby such a polymer particularly improves the processability of the curable composition with regard to the stability of the freshly applied, not yet cured composition.

[0080] Another suitable polymer containing isocyanate groups is a polymer based on a polyol containing at least one dimer fatty acid ester. Such a polymer offers particularly good adhesion properties.

[0081] Such additional polymers are preferably included in an amount of up to 10% by weight per additional polymer, relative to the total weight of all isocyanate group-containing polymers.

[0082] In a preferred embodiment of the invention, the hardenable composition contains at least one latent, moisture-activated hardener, in particular at least one aldimine, preferably in such an amount that the molar ratio of the aldimine groups to the isocyanate groups in the entire composition is in the range of 0.2 to 1.0, in particular 0.5 to 0.9.

[0083] An aldimine of formula (IV) is preferred where n stands for 2 or 3,

[0084] G stands for an n-valent organic residue with 2 to 25 carbon atoms, and

[0085] Z stands for a monovalent hydrocarbon residue with 3 to 20 carbon atoms, possibly containing ether groups, ester groups and / or tertiary amine groups.

[0086] Preferably, G represents the remainder of a diamine or triamine selected from the list consisting of 1,5-pentanediamine, 1,6-hexanediamine, isophoronediamine, 4,4'-methylenebis(cyclohexylamine), 1,3-bis(aminomethyl)cyclohexane, polyoxypropylenediamine with medium molecular weight M n from 200 to 500 g / mol and polyoxypropylenetriamine with medium molecular weight M n from 300 to 500 g / mol after removal of the two or three amine groups.

[0087] Preferably, Z represents a residue selected from the list consisting of 2-propyl, 1,1-dimethyl-2-acetoxyethyl, 1,1-dimethyl-2-lauroyloxyethyl, 1,1-dimethyl-2-(N-morpholino)ethyl, phenyl, methylphenyl, methoxyphenyl and 4-Cio-14-alkylphenyl.

[0088] Particularly preferred are aldimines of formula (IV) selected from the list consisting of N,N'-bis(2,2-dimethyl-3-lauroyloxypropylidene)hexane-1,6-diamine, N,N'-bis(2,2-dimethyl-3-(N-morpholino)propylidene)hexane-1,6-diamine, N,N'-bis(2,2-dimethyl-3-acetoxypropylidene)-3-aminomethyl-3,5,5-trimethylcyclohexylamine, N,N'-bis(2,2-dimethyl-3-lauroyloxypropylidene)-3-aminomethyl-3,5,5-trimethylcyclohexylamine, N,N'-bis(2,2-dimethyl-3-(N-morpholino)propylidene)-3-aminomethyl-3,5,5-trimethylcyclohexylamine, N,N'-Bis(4-Cio-14-alkylbenzylidene)-3-aminomethyl-3,5,5-trimethylcyclohexylamine, N,N'-Bis(2,2-dimethyl-3-lauroyloxypropylidene)polyoxypropylenediamine with medium molecular weight M nfrom 750 to 1050 g / mol, N,N',N"-Tris(2,2-dimethyl-3-lauroyloxypropylidene)polyoxypropylenetriamine with medium molecular weight M n from 1,125 to 1,325 g / mol and N,N'-dibenzylidene polyoxypropylenediamine with medium molecular weight M n from 400 to 700 g / mol.

[0089] The curable composition preferably contains at least one further component selected from fillers, plasticizers, catalysts and adhesion promoters.

[0090] Suitable fillers include, in particular, ground or precipitated calcium carbonates, which may be coated with fatty acids, especially stearates, barites (barytes), quartz flours, quartz sands, dolomites, wollastonites, calcined kaolins, layered silicates such as mica or talc, zeolites, aluminum hydroxides, magnesium hydroxides, silicas including highly dispersed silicas from pyrolysis processes, industrially produced carbon black, graphite, metal powders such as aluminum, copper, iron, silver or steel, PVC powder or hollow spheres.

[0091] Calcium carbonates, which may be coated with fatty acids, especially stearates, calcined kaolins and / or industrially produced carbon blacks are preferred.

[0092] Suitable plasticizers include, in particular, phthalates such as diisononyl phthalate (DINP), diisodecyl phthalate (DIDP) or di(2-propylheptyl) phthalate (DPHP), hydrogenated phthalates such as diisononyl-1,2-cyclohexane dicarboxylate (DINCH), terephthalates such as bis(2-ethylhexyl) terephthalate or diisononyl terephthalate (DINT), hydrogenated terephthalates such as bis(2-ethylhexyl)-1,4-cyclohexane dicarboxylate or diisononyl-1,4-cyclohexane dicarboxylate, isophthalates, trimellitates, adipates such as dioctyl adipate (DOA), azelates, sebacates, citrates, benzoates, glycol ethers, glycol esters, and plasticizers with a polyether structure, in particular poly(oxy-1,2-propylene) monols, diols or triols with blocked Hydroxyl groups, especially in the form of acetyl groups, organic sulfonates or phosphates, especially diphenylcresyl phosphate (DPK), polybutenes,Polyisobutene or plasticizers derived from natural fats or oils, such as in particular epoxidized soybean or linseed oil or rapeseed oil methyl ester, wherein phthalates, hydrogenated phthalates, adipates or plasticizers with a polyether structure are preferred.

[0093] Suitable catalysts are, in particular, compounds containing tertiary amino groups, such as 2,2'-dimorpholinodiethyl ether (DMDEE), as well as organotin(IV) compounds, such as dibutyltin diacetate, dibutyltin dilaurate, dibutyltin dichloride, dibutyltin diacetylacetonate, dimethyltin dilaurate, dioctyltin diacetate, dioctyltin dilaurate or dioctyltin diacetylacetonate, 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, if the hardenable composition contains aldimines, organic acids that accelerate the hydrolysis of aldimines, such as carboxylic acids or sulfonic acids, in particular an aromatic carboxylic acid such as Salicylic acid.

[0094] Suitable adhesion promoters are in particular titanates or organoalkoxysilanes such as epoxysilanes, aminosilanes, iminosilanes, mercaptosilanes, vinylsilanes, (meth)acrylosilanes, carbamatosilanes, alkylsilanes, S-(alkylcarbonyl)mercaptosilanes, or oligomeric forms of these silanes. Epoxysilanes, especially 3-glycidoxypropyltrimethoxysilane or 3-glycidoxypropyltriethoxysilane, are particularly preferred.

[0095] The hardenable composition may also contain additional components, in particular:

[0096] - Oligomeric diisocyanates, especially room-temperature liquid mixtures of MDI and MDI homologs (polymeric MDI or PMDI), HDI biuretes 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 isocyanates 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 allophanes such as Desmodur® VP LS 2102 (from Covestro), IPDI isocyanurates such as in solution as Desmodur® Z 4470 (from Covestro) or in solid form as Vestanat® T1890 / 100 (from Evonik), TDI oligomers such as Desmodur® IL (from Covestro), or mixed isocyanurates based on TDI / HDI such as Desmodur® HL (from Covestro);

[0097] - other latent hardeners, especially oxazolidines or ketimines;

[0098] - Pigments, especially titanium dioxide, chromium oxide, iron oxides or organic pigments;

[0099] - Dyes;

[0100] - Fibers, especially glass fibers, carbon fibers, metal fibers, ceramic fibers, hemp fibers, cellulose fibers or plastic fibers such as polyamide fibers or polyethylene fibers;

[0101] - Nanofillers or nanofibers such as graphene or carbon nanotubes;

[0102] - Solvents;

[0103] - Modifying agents such as hydrocarbon resins, natural or synthetic waxes or bitumen;

[0104] - Rheology modifiers, especially urea compounds, layered silicates such as bentonites, derivatives of castor oil, hydrogenated castor oil, polyamides, polyurethanes, pyrogenic silicas or hydrophobically modified polyoxyethylenes;

[0105] - Desiccants, in particular molecular sieves, calcium oxide, highly reactive isocyanates such as p-tosyl isocyanate, mono-oxazolidines such as Incozol® 2 (from Incorez) or orthoesters;

[0106] - non-reactive thermoplastic polymers, in particular homo- or copolymers of unsaturated monomers, especially from the group comprising ethylene, propylene, butylene, isobutylene, isoprene, styrene, vinyl acetate and alkyl (meth)acrylates, in particular polyethylene (PE), polypropylene (PP), polyisobutylene, ethylene vinyl acetate copolymers (EVA) and atactic poly-a-olefins (APAO);

[0107] - flame-retardant substances, in particular the fillers already mentioned: aluminium hydroxide or magnesium hydroxide, organophosphates, ammonium polyphosphates, melamine or derivatives thereof, boron compounds or antimony compounds;

[0108] - Additives, in particular wetting agents, leveling agents, defoamers, deaerators, stabilizers against oxidation, heat, light or UV radiation or biocides; as well as other substances commonly used in curable compositions.

[0109] It may be useful to dry certain substances chemically or physically before mixing them into the composition.

[0110] The curable composition preferably contains less than 5% by weight, more preferably less than 2% by weight, and particularly less than 1% by weight, volatile organic compounds (VOCs) with a boiling point at normal pressure of less than 250 °C. Such a composition causes particularly low emissions.

[0111] Preferably, the curable composition contains, in relation to the total composition

[0112] - 10 to 80 wt%, preferably 30 to 70 wt%, isocyanate group-containing polymers,

[0113] - 10 to 80 wt%, preferably 20 to 70 wt%, fillers,

[0114] - 0 to 60 wt%, preferably 10 to 50 wt%, plasticizer, and at least one malonate of formula (I), preferably at least one catalyst, preferably at least one organoalkoxysilane and optionally further components.

[0115] The curable composition is produced, in particular, under exclusion of moisture and stored at ambient temperature in moisture-proof containers. A suitable moisture-proof container consists, in particular, of a metal and / or plastic, optionally coated, and is, in particular, a drum, a container, a pail, a bucket, a canister, a box, a bag, a sausage pack, a cartridge, or a tube. The curable composition may be in the form of a one-component or a multi-component, in particular two-component, composition.

[0116] A composition is described as "single-component" if all components of the composition are contained in the same container and are therefore stable during storage.

[0117] A composition is described as "two-component" if the components of the composition are present in two different components, which are stored in separate containers and are only mixed together shortly before or during the application of the composition.

[0118] Preferably, the hardenable composition is one-component.

[0119] A "one-component" product is a hardenable composition whose ingredients are mixed and stored in a single airtight container for long-term stability.

[0120] The curing process begins when the curable composition is applied. The result is the cured composition.

[0121] In the case of a single-component composition, it is applied as is and begins to harden under the influence of moisture or water. To accelerate the hardening process, an accelerator component containing or releasing water and / or a catalyst and / or a hardener can be added to the composition during application, or the composition can be brought into contact with such an accelerator component after application.

[0122] During curing, the isocyanate groups react with each other under the influence of moisture. If the curable composition contains aldimine, the isocyanate groups also react with the hydrolyzing aldimine groups. The entirety of these reactions of the isocyanate groups that lead to the curing of the composition is also referred to as cross-linking. The moisture required for curing preferentially enters the composition from the air (humidity) via diffusion. A skin first forms on the surfaces of the composition that are in contact with air. Curing continues along the direction of diffusion from the outside in, with the skin becoming progressively thicker and eventually covering the entire applied composition.The moisture can also enter the composition additionally or entirely from one or more substrates onto which the composition has been applied and / or originate from an accelerator component that is added to the composition during application or brought into contact with it after application, for example by brushing or spraying.

[0123] The curable composition is preferably applied at ambient temperature, particularly in the range of about -10 to 50°C, preferably -5 to 45°C, particularly 0 to 40°C.

[0124] The curing of the curable composition preferably also takes place at ambient temperature.

[0125] The curable composition has very good storage stability, a long processing time (open time), fast curing, high elasticity with high strength and good adhesion properties, especially on glass and glass ceramics.

[0126] The curable composition is preferably used as an elastic adhesive or elastic sealant or elastic coating, in particular as an elastic adhesive, which also acts as a sealant.

[0127] As an adhesive and / or sealant, the curable composition is particularly suitable for bonding and sealing applications in the construction and manufacturing industries or in vehicle construction, especially for parquet bonding, assembly, component bonding, module bonding, window bonding, joint sealing, body sealing, seam sealing, or cavity sealing. Elastic bonding in vehicle construction includes, for example, the bonding of parts such as plastic covers, trim strips, flanges, bumpers, driver's cabs, or other add-on parts to the painted body of a vehicle, or, in particular, the bonding of windows into the body, with the vehicles being, in particular, automobiles, trucks, buses, rail vehicles, or ships.

[0128] As a sealant, the curable composition is particularly suitable for the elastic sealing of joints, seams or cavities of all kinds, especially joints in construction such as expansion joints or connection joints between components, or floor joints in civil engineering.

[0129] As a coating, the curable composition is particularly suitable for protecting and / or sealing buildings or parts thereof, especially in the area of ​​plastic materials, particularly for balconies, terraces, roofs, especially flat roofs or slightly inclined roof surfaces or roof gardens, or inside buildings under tiles or ceramic slabs in wet rooms or kitchens, or in collection trays, channels, shafts, silos, tanks or wastewater treatment plants.

[0130] The curable composition can be formulated to have a paste-like consistency with thixotropic properties. Such a composition is applied using a suitable device, for example from commercially available cartridges, drums, or pails, for instance in the form of a caterpillar, which may have a substantially round or triangular cross-sectional area.

[0131] The curable composition can be formulated to be liquid and self-leveling or only slightly thixotropic, allowing it to be poured for application. As a coating, it can then be spread evenly to the desired thickness, for example, using a roller, squeegee, notched trowel, or spatula. Typically, a layer thickness of 0.5 to 3 mm, particularly 1 to 2.5 mm, is applied in a single step. Suitable substrates that can be bonded, sealed, or coated with the curable composition include, in particular,

[0132] - Glass, glass ceramics, concrete, mortar, cement screed, fiber cement, in particular fiber cement boards, brick, brick, gypsum, in particular gypsum boards or anhydrite screed, or natural stones such as granite or marble;

[0133] - Metals or alloys such as aluminium, copper, iron, steel, non-ferrous metals, including surface-treated metals or alloys such as galvanised or chromium-plated metals;

[0134] - coated or painted substrates, in particular painted tiles, painted concrete, powder-coated metals or alloys or painted sheets;

[0135] - Paints or varnishes, especially automotive topcoats;

[0136] - Plastics such as, in particular, rigid or flexible PVC, polycarbonate, polystyrene, polyester, polyamide, PMMA, ABS, SAN, epoxy resins, phenolic resins, PUR, POM, TPO, PE, PP, EPM, EPDM or blends of polycarbonate, as well as other plastics such as, in particular, ABS and / or SAN, whereby these plastics may be untreated or surface-treated, for example by means of plasma, corona or flame, as well as fiber-reinforced plastics such as, in particular, carbon fiber-reinforced plastics (CFRP), glass fiber-reinforced plastics (GFRP) or sheet moulding compounds (SMC);

[0137] - Repair or leveling compounds based on PCC (polymer-modified cement mortar) or ECC (epoxy resin-modified cement mortar);

[0138] - Asphalt or bitumen;

[0139] - Leather, textiles, paper, wood, wood-based materials bonded with resins such as phenolic, melamine or epoxy resins, resin-textile composites or other so-called polymer composites;

[0140] - Insulating foams, especially made of EPS, XPS, PUR, PIR, rock wool, glass wool or foamed glass (Foamglas).

[0141] The substrates can be pretreated before application if necessary, in particular by physical and / or chemical cleaning processes or by applying an activator or primer. Two identical or two different substrates can be bonded and / or sealed.

[0142] Preferably, the curable composition has a paste-like consistency and is used as an adhesive in the automotive industry, especially for window bonding, particularly without pretreatment of the substrates by means of primers.

[0143] Another object of the invention is the hardened composition obtained from the described hardenable composition after contact with moisture.

[0144] Preferably, the cured composition is elastic and has in particular a tensile strength of at least 2 MPa, preferably at least 3 MPa, and an elongation at break of at least 150%, preferably at least 300%, determined according to DIN EN 53504 at a tensile speed of 200 mm / min on dumbbell-shaped test specimens with a length of 75 mm, a web length of 30 mm, a web width of 4 mm and a thickness of 2 mm.

[0145] Preferably, the curable composition is used in a bonding or sealing process comprising the steps

[0146] (i) Applying the curable composition

[0147] - on a first substrate and contact of the composition with a second substrate within the open time of the composition, or

[0148] - on a first and on a second substrate and combining the two substrates within the open time of the composition, or

[0149] - between two substrates,

[0150] (ii) Hardening of the composition by contact with moisture.

[0151] The bonding or sealing process yields a bonded or sealed article. This article may be a structure or part thereof, in particular a building structure, a roof, a stairwell or a facade, or it may be an industrial or consumer good, in particular a window, a lamp, a traffic light, a household appliance or a means of transport such as, in particular, an automobile, a bus, a caravan, a truck, a rail vehicle, a ship, an aircraft or a helicopter, or an attachment thereof.

[0152] Examples

[0153] The following are exemplary embodiments intended to further illustrate the described invention. Of course, the invention is not limited to these described embodiments.

[0154] A temperature of 23±1°C and a relative humidity of 50±5% are referred to as "standard climate" ("NC").

[0155] Unless otherwise stated, the chemicals used were from Sigma-Aldrich Chemie GmbH.

[0156] Viscosity was measured using a thermostatically controlled cone-plate viscometer Rheotec RC30 (cone diameter 25 mm, cone angle 1°, cone tip-plate distance 0.05 mm, shear rate 10 s). -1 ) measured.

[0157] The content of monomeric diisocyanate was determined by HPLC (detection via photodiode array; 0.04 M sodium acetate / acetonitrile as mobile phase) after prior derivatization with N-propyl-4-nitrobencylamine.

[0158] Production of malonate compounds

[0159] Malonat M1

[0160] 72.13 g (0.36 mol OH) of Ci2-14-alkyl alcohol (Exxal® 13, OH number 280 mg KOH / g, from ExxonMobil) was reacted with 32.03 g (0.2 mol) of diethyl malonate and 0.15 g of tetra-n-butyl titanate (Tyzor® TnBT, from Dorf Ketal) under vacuum and after removal of the volatile components, especially ethanol, at a temperature of 140 °C. A clear, colorless liquid with a calculated malonate equivalent weight of 439 g / eq was obtained.

[0161] Malonat M2

[0162] 135.0 g (0.18 mol OH) Butanol-started polyoxypropylene monol (Synalox® 100-20B, mean molecular weight M n (approx. 750 g / mol, from Dow) was reacted with 16.0 g (0.1 mol) of diethyl malonate and 0.1 g of tetra-n-butyl titanate (Tyzor® TnBT, from Dorf Ketal) under vacuum and after removal of the volatile components at a temperature of 140 °C. A clear, colorless liquid with a calculated malonate equivalent weight of 1427 g / eq was obtained.

[0163] Production of isocyanate group-containing polymers:

[0164] Polymer P1 :

[0165] 725 g of ethylene oxide-terminated polyoxypropylenetriol (Desmophen® 5031 BT, OH number 28.0 mg KOH / g, OH functionality approx. 2.3, from Covestro) and 275 g of 4,4'-diphenylmethane diisocyanate (Desmodur® 44 MC L, from Covestro) were reacted at 80 °C according to a known procedure to form a reaction mixture with an NCO content of 7.6 wt%. Subsequently, the volatile components, in particular unreacted 4,4'-diphenylmethane diisocyanate, were removed by distillation in a short-path evaporator (jacket temperature 180 °C, pressure 0.1 to 0.005 mbar), yielding a polymer with an NCO content of 1.7 wt%, a viscosity at 20 °C of 19 Pa s and a monomeric 4,4'-diphenylmethane diisocyanate content of 0.04 wt%.

[0166] Polymer P2:

[0167] 513.3 g of polyoxypropylenediol (Acclaim® 4200, OH number 28 mg KOH / g, from Covestro), 256.7 g of ethylene oxide-terminated polyoxypropylenetriol (Caradol® MD34-02, OH number 35 mg KOH / g, from Shell) and 64.2 g of toluene diisocyanate (Desmodur® T 80 P, from Covestro) were reacted at 80 °C according to a known process to form a polymer with an NCO content of 1.5 wt% and a viscosity at 20 °C of 22 Pa s.

[0168] Polymer P3:

[0169] 597.5 g of dimer fatty acid-based amorphous polyester diol (Priplast® 1838, OH number 110 mg KOH / g, from Cargill) and 402.5 g of 4,4'-diphenylmethane diisocyanate (Desmodur® 44 MC L, from Covestro) were reacted at 80 °C to form a reaction mixture with an NCO content of 11.0 wt%. Subsequently, the volatile components, in particular unreacted 4,4'-diphenylmethane diisocyanate, were removed by distillation in a short-path evaporator (jacket temperature 180 °C, pressure 0.1 to 0.005 mbar), yielding a polymer with an NCO content of 2.8 wt%, a viscosity at 20 °C of 312 Pa s and a monomeric 4,4'-diphenylmethane diisocyanate content of 0.09 wt%.

[0170] Polymer P4:

[0171] 1000.0 g of semi-crystalline polyester diol (Dynacoll® 7360, OH number 34 mg KOH / g, from Evonik) and 142 g of 4,4'-diphenylmethane diisocyanate (Desmodur® 44 MC L, from Covestro) were reacted at 80 °C to form a polymer that is solid at room temperature with an NCO content of 2.0 wt%.

[0172] Production of moisture-curable compositions:

[0173] Compositions Z-1 to Z-4:

[0174] For each composition, the ingredients listed in Table 1 were thoroughly mixed in the specified quantities (in parts by weight) using a planetary mixer under vacuum and exclusion of moisture, the composition was filled into aluminium cartridges and stored airtight at room temperature.

[0175] The polymer P4 was melted before being added.

[0176] 3-Glycidoxypropyltrimethoxysilane (Silguest® A-187 from Momentive) was used as the "epoxysilane".

[0177] Omyacarb® 5-GU (from Omya) was used as the "chalk".

[0178] Monarch® 570 (from Cabot) was used as the "Russ".

[0179] A solution of 1 wt.% dibutyltin dilaurate (DBTDL) and 12 wt.% 2,2'-dimorpholinodiethyl ether (DMDEE) in dioctyl adipate was used as the "catalyst solution".

[0180] Each composition was then tested as follows:

[0181] As a measure of storage stability, the dispensing force was determined after storing a sealed cartridge for 3 days at room temperature and for 7 or 14 days in a convection oven at 60 °C. Cartridges stored at 60 °C were cooled to room temperature before the dispensing force was measured. The dispensing force was measured using a dispensing tool (Zwick / Roell Z005) by screwing a 5 mm inner diameter nozzle onto the cartridge and measuring the force required to dispense the composition through the nozzle at a speed of 60 mm / min. The value given is an average of the forces measured after dispensing strokes of 22 mm, 24 mm, 26 mm, and 28 mm. A slight increase in the dispensing force after storage at 60 °C compared to the initial value after 3 days at room temperature indicates good storage stability.

[0182] The skin formation time was determined as a measure of the open time (working time). For this purpose, a few grams of the composition were applied to cardboard in a layer approximately 2 mm thick, and the time was measured under standard climate conditions until, upon lightly tapping the surface of the composition with an LDPE pipette, no residue remained on the pipette. The skin formation time was determined for material stored for 3 days at room temperature and for material stored for 7 and 14 days at 60 °C. A consistent value for the skin formation time is a further indication of good storage stability of the composition.

[0183] To determine the mechanical properties, each composition was pressed between two silicone-coated release papers to form a 2 mm thick film and stored for 7 days under standard climatic conditions. After removing the release papers, several test specimens (dumbbells with a length of 75 mm, a web length of 30 mm, and a web width of 4 mm) were punched out, and the tensile strength, elongation at break, and modulus of elasticity at 5% (at 0.5–5% elongation) were determined according to DIN EN 53504 at a tensile speed of 200 mm / min.

[0184] Adhesion was determined by applying the composition in the form of five parallel beads, each approximately 10 mm wide, 5 mm high, and 15 mm long, to the respective substrate. The substrates were first wiped with a paper towel soaked in a 1:1 mixture of isopropanol and water by weight, and then wiped again with a dry paper towel (wipe on, wipe off). After a curing period of seven days under standard conditions, the adhesion of the cured composition was initially tested by making a small incision at the narrow end of the first bead just above the adhesive surface. The incised end of the bead was then held with round-nose pliers, and an attempt was made to pull the bead away from the substrate. The bead was then cut again down to the substrate, the exposed portion was rolled up with the round-nose pliers, and another attempt was made to pull the bead away from the substrate. In this way, the entire bead was pulled away from the substrate.The adhesion was then assessed based on the fracture pattern as described below. After a curing period of 14 days under standard climate conditions, the adhesion was tested again using the second bead as described. The test specimen was then immersed in deionized water for 7 days, then stored for 2 hours under standard climate conditions, and the third bead was then tested for adhesion as described. Next, the test specimen was stored in a convection oven at 80°C for 24 hours, followed by 2 hours under standard climate conditions, and the fourth bead was then tested for adhesion as described. Finally, the test specimen was stored for 7 days at 70°C and 100% relative humidity, followed by 2 hours under standard climate conditions, and the fifth bead was tested for adhesion as described.

[0185] Adhesion was tested on glass and on various ceramic substrates using the following test substrates from Rocholl: Glass Air Side, Glass Tin Side, Ceramic JM 1 L5350, Ceramic JM 1 PBL3020, Ceramic Ferro 14531 1 R7344 and Ceramic Ferro 14316 1 R7363.

[0186] Adhesion was assessed based on the proportion of the area on which a cohesive failure pattern (CF) was present after the bead was cut away, according to the following scale:

[0187] "1" stands for 90 to 100% CF (very good adhesion)

[0188] "2" represents 70 to 89% CF

[0189] "3" represents 50 to 69% CF

[0190] "4" represents 25 to 49% CF

[0191] "5" represents 0 to 24% CF

[0192] The results are given in the order of storage: 7d RT, 14d RT, 7d H2O, 1d 80°C and 7d 70°C / 100% relative humidity.

[0193] The results are shown in Table 1. The compositions marked "(Ref.)" are comparative examples.

[0194] Table 1 shows that the compositions Z1 and Z2 according to the invention exhibited good storage stability with a small increase in the extrusion force after storage at 60 °C in a sealed container and very good adhesion properties to glass and various ceramic substrates. Composition Z3 (Ref.) with diethyl malonate as a stabilizer also showed good storage stability, but had significantly poorer adhesion properties, particularly on ceramic substrates, especially type JM 1 L5350. Composition Z4 (Ref.) without malonate showed insufficient storage stability.

[0195]

[0196] Table 1: Composition and properties of Z1 to Z4.

[0197] 1 containing 1 wt.% DBTDL and 12 wt.% DM DEE in DOA

[0198] 2 not determined

Claims

Patent claims:

1. Use of at least one malonate of formula (I) as a stabilizer for storage stability in isocyanate group-containing compositions, where R 1 for a hydrocarbon residue, possibly containing ether groups, with 11 to 100 carbon atoms, and R 2 for R 1 or R 3 stands, where R 3 stands for a possibly branched alkyl group with 1 to 4 carbon atoms.

2. Use according to claim 1, characterized in that R 1 for a hydrocarbon residue with 11 to 20 C atoms, preferably 12 to 18 C atoms, or for a hydrocarbon residue containing ether groups with 11 to 100 C atoms, preferably 12 to 80 C atoms.

3. Use according to one of claims 1 or 2, characterized in that R 1selected from the list consisting of undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl and octadecyl, wherein these alkyl groups are linear or branched, Containing 3,6-dioxa-1-dodecyl, 3,6,9-trioxa-1-tridecyl and other monofunctional polyether residues, repeating units selected from 1,2-ethyleneoxy, 1,2-propylenoxy, 1,3-propylenoxy and 1,4-butylenoxy, wherein the monofunctional polyether residue is the residue of an alkanol-started poly(oxy-1,2-propylene)monol or poly(oxy-1,2-ethylene)monol with an average molecular weight M determined by gel permeation chromatography n from 300 to 2,000 g / mol, preferably 350 to 1,500 g / mol, in particular 500 to 1,000 g / mol, after removal of the hydroxyl group, where alkanol particularly stands for butanol.

4. Use according to any one of claims 1 to 3, characterized in that the stabilizer comprises a mixture of malonates of formula (I), when which a part of the remains R 2 for R 1 stands and part of the remains R 2 for R 3 stands.

5. Use according to any one of claims 1 to 4, characterized in that the isocyanate group-containing composition contains 0.3 to 15 meq, preferably 0.5 to 8 meq, in particular 1 to 5 meq, malonate groups from malonates of formula (I) based on 100 parts by weight of the isocyanate group-containing composition.

6. Use according to any one of claims 1 to 5, characterized in that the malonate of formula (I) is a reaction product from the transesterification of at least one malonate of formula (II) with at least one monoalcohol of formula (III) with removal of alcohol of formula R 3 — OH includes, OO X Ä R3- O'^X ^\ O -R 3 (I I) R 1 — OH (Hl) wherein the transesterification preferably took place in a molar ratio of monoalcohol of formula (III) to malonate of formula (II) in the range of 1 to 2, preferably 1.2 to 2.0, more preferably 1.5 to 1.9, in particular 1.7 to 1.

9.

7. A curable isocyanate-containing composition comprising at least one isocyanate-containing polymer and, as a stabilizer for storage stability, at least one malonate of formula (I) as defined in any one of claims 1 to 6.

8. Composition according to claim 7, characterized in that the isocyanate group-containing polymer has an NCO content of 0.5 to 8 wt%, preferably 0.75 to 5 wt%, in particular 1 to 3 wt%, based on the total polymer.

9. Composition according to one of claims 7 or 8, characterized in that the isocyanate groups of the isocyanate-containing polymer are derived from at least one monomeric diisocyanate selected from the list consisting of 4,4'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, 1,6-hexane diisocyanate, isophorone diisocyanate, 4,4'-diisocyanatodicyclohexylmethane and 1-methyl-2,4(6)-diisocyanatocyclohexane.

10. Composition according to one of claims 7 to 9, characterized in that the composition contains at least one further component selected from fillers, plasticizers, catalysts and adhesion promoters.

11. Composition according to one of claims 7 to 10, characterized in that the curable composition is one-component.

12. Cured composition obtained from the composition according to any one of claims 7 to 11 after contact with moisture.

13. Cured composition according to claim 12, characterized in that the cured composition is elastic and in particular has a tensile strength of at least 2 MPa, preferably at least 3 MPa, and an elongation at break of at least 150%, preferably at least 300%, determined according to DIN EN 53504 at a tensile speed of 200 mm / min on dumbbell-shaped test specimens with a length of 75 mm, a web length of 30 mm, a web width of 4 mm and a thickness of 2 mm.

14. Methods for bonding or sealing, comprising the steps (i) Applying the composition according to any one of claims 7 to 11 - on a first substrate and contact of the composition with a second substrate within the open time of the composition, or - on a first and on a second substrate and combining the two substrates within the open time of the composition, or - between two substrates, (ii) Hardening of the composition by contact with moisture.

15. Bonded or sealed article obtained from the method according to claim 14.

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