Polymer composition which can be cured at room temperature and which is made of polyaldehyde and 1,3 keto ester
Patent Information
- Application Number
- EP2023734253
- Authority / Receiving Office
- EP · EP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2022-07-13
- Filing Date
- 2023-06-21
- Publication Date
- 2025-05-21
AI Technical Summary
Existing room temperature-curable polymer compositions for adhesives, sealants, and coatings face challenges such as moisture sensitivity, bubble formation, incomplete polymerization, and toxicity issues due to the use of isocyanate groups and silane-functional polymers, which affect storage stability, application thickness, and durability.
A two-component composition comprising compounds with aldehyde groups and 1,3-ketoester groups, with average molecular weights between 400 to 20,000 g/mol, that are non-toxic and not sensitive to moisture, allowing for flexible stoichiometry and rapid curing without emissions, using conventional non-metallic catalysts like tertiary amines.
The composition achieves high elasticity, strength, and resistance to heat and water, with improved storage stability and application flexibility, resulting in a robust and long-lasting adhesive, sealant, or coating with controlled curing rates.
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Abstract
Description
[0001] ROOM TEMPERATURE-CURING POLYMER COMPOSITION OF
[0002] POLYALDEHYDE AND 1,3-KETOESTER
[0003] Technical area
[0004] The invention relates to two-component compositions and their use as room temperature curable elastic adhesives, sealants or coatings.
[0005] State of the art
[0006] Reactive polymer compositions that cure at room temperature and can be used as adhesives, sealants, or coatings with elastic properties are well known. Polyurethane systems, which cure through the reaction of isocyanate groups with polyols and / or moisture, forming particularly highly elastic polymers, are widely used. The formulation, manufacture, and use of polyurethane systems pose a number of challenges in practice. They usually contain significant amounts of monomeric diisocyanates, which can irritate the eyes, skin, and mucous membranes. The moisture sensitivity of the isocyanate groups can lead to premature crosslinking reactions associated with increased viscosity and even gelling, thus impairing shelf life and storage stability.In single-component systems, the water required for curing must penetrate from the outside in the form of atmospheric moisture, making application in thick layers or between moisture-proof substrates difficult. Two-component systems with a polyol and an isocyanate component pose the problem that the isocyanate groups can react not only with the hydroxyl groups of the polyols, but also with any water present. Particularly in high ambient humidity, this can trigger blistering and cause incomplete polymerization with chain terminations due to only partially reacted polyols, leading to a more or less severe loss of strength and elasticity. These problems are rarely encountered when mercury catalysts are used, which catalyze the reaction with the polyols very selectively.However, due to their high toxicity, mercury catalysts have long been discontinued. As an alternative, two-component polyurethanes are often catalyzed with tin compounds and / or tertiary amines, which are significantly less selective and can lead to bubble formation, especially in high ambient humidity. Bismuth or zirconium catalysts have higher selectivity; however, these and other alternative metal catalysts are sensitive to hydrolysis, resulting in a significant loss of catalytic activity, which in turn can lead to curing problems.
[0007] Reactive polymer compositions based on silane-functional polymers (SMP / STP) and silicones are also widely used. These polymer systems cure through hydrolysis and condensation of silane groups, releasing alcohols, especially methanol or ethanol, or oximes, which are toxic and cause VOC emissions. Furthermore, they usually contain high amounts of low-molecular-weight silanes as crosslinkers or drying agents, which are also harmful to health. Due to the moisture sensitivity of the silane groups, these polymer systems are also challenging to manufacture and use and do not always produce the desired results. Also common are water-based polymer systems, which are usually based on acrylate or polyurethane dispersions. These cure through water evaporation and coalescence and are largely free of chemical reactive groups.However, they can only be used in relatively thin layers and only between open-pored substrates. The curing speed is highly dependent on ambient humidity, and they exhibit high shrinkage. After curing, they are more sensitive to water due to the surfactants they contain, which are necessary for the production and stability of the dispersion, which can lead to reduced durability, especially in outdoor applications.
[0008] US 5,452,653 describes the crosslinking of compounds containing acetoacetate groups with aromatic aldimines. Highly solvent-containing acrylate polymers containing acetoacetate groups or aqueous polyurethane-acrylate dispersions containing acetoacetate groups are used. Description of the invention
[0009] The object of the present invention is therefore to provide a new, room temperature curable polymer composition which is suitable as an elastic adhesive, sealant or coating and overcomes the disadvantages of the known polymer systems.
[0010] Surprisingly, this object is achieved with a curable composition as described in claim 1. The composition comprises a first component containing aldehyde group-containing compounds and a second component containing 1,3-ketoester group-containing compounds, wherein the average molecular weight M n at least one of the two components, with respect to the aldehyde- or 1,3-ketoester-containing compounds, is in the range of 400 to 20,000 g / mol. This composition has several advantageous and surprising properties compared to prior-art room-temperature-curable polymer systems.
[0011] Both the aldehyde-containing compounds and the 1,3-ketoester-containing compounds are substances of low toxicological concern, do not require hazard labeling, and can be handled without special precautions. The composition according to the invention is not sensitive to moisture and blistering and allows for a high degree of freedom in formulation, since additives commonly used in curable compositions can be used in both components without causing problems with the storage stability of the respective component.Surprisingly, the composition is very tolerant with regard to the stoichiometry of the reactive groups. A cured, non-sticky material with high extensibility and strength, and good resistance to heat and water, is produced at a ratio of the number of 1,3-ketoester groups to the number of aldehyde groups across the entire range from 1 to 2 or more. This is very surprising, given that state-of-the-art reactive systems typically exhibit a sharp decline in mechanical quality with significant deviations from the optimal stoichiometry of the reactive groups, which is usually close to 1:1. For these reasons, the mixing ratio of the two components can be adjusted almost arbitrarily, allowing considerable freedom in the application method and simple, very reliable processing with a high degree of error tolerance.The composition is easily processable under ambient conditions, without the need for organic solvents for dissolving or diluting, or water for emulsifying or dispersing components. The composition cures surprisingly quickly and smoothly under ambient conditions, regardless of humidity, without generating emissions. A particularly advantageous feature is that the curing rate is highly controllable with conventional catalysts, particularly non-metallic bases such as tertiary amines, amidines, or guanidines. Curing produces a non-sticky, elastic polymer of high strength and elongation, with good tear resistance and resistance to heat and water.Due to the combination of these advantageous properties, the composition according to the invention has a particularly easy handling without special protective measures as well as a high robustness and durability, both during the production and storage of the components, during their use in a wide range of ambient and application conditions and fluctuations in the mixing ratio, as well as after curing under mechanical, thermal or chemical stress.
[0012] The composition according to the invention is thus highly suitable for use as a high-quality elastic adhesive, sealant, or coating. 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.
[0013] Ways to implement the invention
[0014] The invention relates to a curable composition comprising
[0015] - a first component containing aldehyde group-containing compounds comprising at least one compound having two or more aldehyde groups and
[0016] - a second component containing 1,3-ketoester group-containing compounds comprising at least one compound having two or more 1,3-ketoester groups of the formula (I), OO
[0017] - A (l) where R 1 represents a monovalent hydrocarbon radical having 1 to 6 C atoms, wherein the average molecular weight Mn of at least one of the two components with respect to the aldehyde or 1,3-ketoester group-containing compounds is in the range from 400 to 20,000 g / mol.
[0018] O
[0019] “Aldehyde groups” are functional groups of the formula which are bound by the dashed line.
[0020] A dashed line in the formulas in this document represents the bond between a substituent and the corresponding molecular residue. The term "molecular weight" refers to the molar mass (in grams per mole) of a molecule. The term "average molecular weight" refers to the number average molecular weight (M n ) of a polydisperse mixture of oligomeric or polymeric molecules. It is determined by gel permeation chromatography (GPC) using polystyrene as a standard.
[0021] 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 3 months up to 6 months or more, without its application or use properties being changed by storage to an extent relevant to its use.
[0022] Substance names beginning with “poly” such as polyacetoacetate, polyaldehyde or polyol refer to substances that formally contain two or more of the functional groups mentioned in their name per molecule.
[0023] “Room temperature” is defined as a temperature of 23 °C.
[0024] 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.
[0025] The first and second components of the curable composition are individually stable and are stored in separate containers until they are mixed together shortly before or during application.
[0026] The curable composition is preferably not water-based. It is preferably largely free of water or contains only a low water content. Such a composition cures quickly regardless of ambient humidity, can be applied in thick layers and / or between waterproof substrates, and exhibits minimal shrinkage during curing.
[0027] The curable composition preferably contains less than 10% by weight, preferably less than 5% by weight, in particular less than 2% by weight, of water based on the total composition.
[0028] The curable composition is preferably free of compounds containing aldehyde or 1,3-ketoester groups, which are present as an emulsion or dispersion. Thus, the compounds containing aldehyde or 1,3-ketoester groups are preferably largely free of ionic groups or precursors thereof, and largely free of longer poly(oxyethylene) chains, as are common in surfactants. Such a composition has high water resistance. In particular, the aldehyde-containing compounds of the first component and the 1,3-ketoester-containing compounds of the second component each have a content of acid groups or ionic groups of less than 0.1% by weight, preferably less than 0.05% by weight, based on the aldehyde-containing or 1,3-ketoester-containing compounds. The ionic groups are in particular carboxylate groups, ammonium groups, or sulfonate groups.In the curable composition, the average molecular weight M. n at least one of the two components, with respect to the aldehyde- or 1,3-ketoester-containing compounds, in the range of 400 to 20,000 g / mol. Such a composition cures to form an elastic, high-strength polymer.
[0029] Preferably, at least one of the two components has an average molecular weight M n The molecular weight of the aldehyde- or 1,3-ketoester-containing compounds is in the range of 1,000 to 20,000 g / mol, preferably 1,500 to 15,000 g / mol, in particular 2,000 to 10,000 g / mol. This enables particularly high extensibility.
[0030] Preferably, the compound with two or more aldehyde groups is liquid at room temperature. In particular, it has a viscosity at 20 °C of 0.2 to 700 Pa s, preferably 0.3 to 500 Pa s, particularly preferably 0.5 to 200 Pa s, in particular 1 to 100 Pa s, measured using a cone-plate viscometer with a cone diameter of 10 mm, a cone angle of 1°, a cone-tip-to-plate distance of 0.05 mm, and a shear rate of 10 s -1 , for viscosities of less than 1 Pa s with a cone diameter of 50 mm. Such compounds are easy to handle at ambient temperatures, even without the addition of solvents or thinners.
[0031] Preferred compounds with two or more aldehyde groups are polymers containing aldehyde groups.
[0032] Preferably, the average molecular weight M nof the first component with respect to the aldehyde group-containing compounds in the range from 1,000 to 20,000 g / mol, preferably 1,500 to 15,000 g / mol, in particular 2,000 to 10,000 g / mol, measured by gel permeation chromatography (GPC) against polystyrene as standard. Such a component is easy to handle at ambient temperatures even without the addition of solvents or thinners and enables polymers with high extensibility and elasticity.
[0033] Preferably, the average aldehyde functionality of the aldehyde group-containing
[0034] Compounds in the first component range from 1.6 to 4, preferably 1.8 to 3.5, particularly preferably 2.0 to 3.0, especially 2.2 to 3.0. This enables cured compositions with high ductility, strength, and durability.
[0035] Preferably, the aldehyde group-containing compounds comprise a polymer having a polymer backbone containing poly(oxyalkylene) units and / or polyester units.
[0036] Preferred poly(oxyalkylene)s are poly(oxyethylene), poly(oxy-1,2-propylene), poly(oxy-1,3-propylene), poly(oxy-1,4-butylene), poly(oxy-1,2-butylene) or a mixture of these poly(oxyalkylenes). Of these, preference is given to poly(oxy-1,2-propylene), poly(oxy-1,3-propylene) or poly(oxy-1,4-butylene), in particular poly(oxy-1,2-propylene), which may contain from 0 to 25% by weight of poly(oxyethylene) units based on the poly(oxyalkylene) backbone, in particular at the chain ends. Aldehyde-functional polymers with such a backbone have low viscosity and are therefore particularly easy to handle and particularly hydrophobic. They enable compositions with particularly good processability, high extensibility and good water resistance.
[0037] Preferred polyesters are esters of dicarboxylic acids and di- or triols, triglycerides, or polyesters based on dimer or trimer fatty acids. Polyesters derived from dimer fatty acids or from castor oil, castor oil derivatives, or vegetable oils are particularly preferred. Aldehyde-functional polymers with such a backbone are particularly hydrophobic and enable compositions with particularly good heat and water resistance. Furthermore, they are based on renewable raw materials and are therefore particularly sustainable.
[0038] Preferably, the compound with two or more aldehyde groups additionally contains urethane groups. This results in compositions with particularly high extensibility. Preferably, the aldehyde-containing compounds comprise a urethane-containing polymer that is liquid at room temperature and has an average molecular weight M nfrom 1,000 to 20,000 g / mol, preferably 1,500 to 15,000 g / mol, in particular 2,000 to 10,000 g / mol, and an average aldehyde functionality of 1.8 to 3.5, particularly preferably 2.0 to 3.0, in particular 2.2 to 3.0.
[0039] Preferably, the compound having two or more aldehyde groups is obtained from the reaction of at least one hydroxyaldehyde with at least one isocyanate group-containing polymer or at least one polyisocyanate.
[0040] Particularly suitable as hydroxyaldehyde are compounds having a molecular weight in the range of 60 to 500 g / mol, preferably 60 to 250 g / mol.
[0041] Particularly suitable are 2-hydroxyacetaldehyde, 3-hydroxybutanal, 3-hydroxypivalaldehyde, 5-hydroxypentanal, 2-(2-hydroxyethoxy)acetaldehyde, 3-(2-hydroxyethoxy)propanal, 5-hydroxymethylfurfural, alkoxylated o-, m- or p-hydroxybenzaldehyde or alkoxylated vanillin, where "alkoxylated" preferably stands for (mono- or poly-) "ethoxylated" or "propoxylated", as well as 4,4'-(2-hydroxypropane-1,3-diyl)-bis(oxy)-bis(benzaldehyde) or 4,4'-(2-hydroxypropane-1,3-diyl)-bis(oxy)-bis(3-methoxybenzaldehyde).
[0042] Preferred are ethoxylated salicylaldehyde, especially 2-(2-hydroxyethoxy)benzaldehyde, ethoxylated vanillin, especially 4-(2-hydroxyethoxy)-3-methoxybenzaldehyde, 5-hydroxymethylfurfural, N'-2-hydroxyethyl-N-piperazinyl-2,2-dimethylpropanal, or N'-3-hydroxypropyl-N-piperazinyl-2,2-dimethylpropanal. These hydroxyaldehydes are accessible using simple processes and enable aldehyde-containing compounds with low viscosity and thus good handling, as well as compositions with good processability and high strength with high extensibility.
[0043] 5-Hydroxymethylfurfural is particularly preferred as a hydroxyaldehyde. This hydroxyaldehyde is accessible from renewable raw materials and, surprisingly, enables particularly low-viscosity compounds with aldehyde groups and curable compositions with particularly good processability and high strength, ductility, and resistance to heat and water.
[0044] Particularly suitable as isocyanate group-containing polymers for the production of compounds having two or more aldehyde groups are reaction products of polyols with diisocyanates, in particular in a molar NCO / OH ratio of 1.5 / 1 to 10 / 1, wherein unreacted monomeric diisocyanates have optionally been removed from the polymer.
[0045] The isocyanate group-containing polymer preferably has a content of free isocyanate groups in the range from 0.5 to 15% by weight, particularly preferably 1 to 10% by weight, in particular 1.5 to 6% by weight, based on the polymer.
[0046] A particularly preferred isocyanate-containing polymer is a reaction product from the reaction of at least one diisocyanate and at least one polyol in an NCO / OH ratio of at least 3 / 1, preferably 3 / 1 to 10 / 1, in particular 4 / 1 to 8 / 1, followed by the removal of a large portion of the monomeric diisocyanate by means of a suitable separation process, so that the isocyanate-containing polymer ultimately has a monomeric diisocyanate content of at most 0.2% by weight, based on the polymer. Such an isocyanate-containing polymer enables aldehyde-functional polymers with a particularly low content of reaction products of monomeric diisocyanate and hydroxyaldehyde, in particular less than 0.5% by weight of these reaction products, based on the aldehyde-functional polymer. This enables curable compositions with particularly simple processing, long open times, rapid curing, and particularly good flexibility.
[0047] Particularly suitable diisocyanates are 1,6-hexane diisocyanate (HDI), 2,2(4),4-trimethyl-1,6-hexane diisocyanate (TMDI), 1-methyl-2,4(6)-diisocyanatocyclohexane (HeTDI), isophorone diisocyanate (IPDI), 4,4'-diisocyanatodicyclohexylmethane (H12MDI), 4(2),4'-diphenylmethane diisocyanate (MDI), or 2,4(6)-toluene diisocyanate. HDI, IPDI, TDI, or MDI are preferred. IPDI is particularly preferred. This results in particularly easy-to-process compositions that cure to form polymers with high strength and extensibility.
[0048] Particularly suitable as polyol are
[0049] - Polyether polyols, in particular polyoxyalkylene diols or polyoxyalkylene triols, in particular polymerization products of ethylene oxide or 1,2-propylene oxide or 1,2- or 2,3-butylene oxide or oxetane or tetrahydrofuran, or mixtures thereof, where these can be polymerized with the aid of a starter molecule having two or more active hydrogen atoms, in particular a starter molecule such as water, ammonia or a compound having several OH or NH groups such as, for example, 1,2-ethanediol, 1,2- or 1,3-propanediol, neopentyl glycol, diethylene glycol, triethylene glycol, the isomeric dipropylene glycols or tripropylene glycols, the isomeric butanediols, pentanediols, hexanediols, heptanediols, octanediols, nonanediols, decanediols, undecanediols, 1,3- or 1 ,4-cyclohexanedimethanol, bisphenol A, hydrogenated bisphenol A, 1,1,1-trimethylolethane, 1,1,1-trimethylolpropane, glycerol or aniline, or mixtures of the aforementioned compounds.
[0050] Preferred polyether polyols are polyoxypropylene diols or polyoxypropylene triols, or so-called ethylene oxide-terminated (EO-endcapped or EO-tipped) polyoxypropylene diols or triols. The latter are polyoxyethylene-polyoxypropylene mixed polyols, which are obtained in particular by further alkoxylating polyoxypropylene diols or triols with ethylene oxide after completion of the propoxylation reaction, thus ultimately exhibiting primary hydroxyl groups.
[0051] Preferred polyether polyols have a degree of unsaturation of less than 0.02 mEq / g, in particular less than 0.01 mEq / g.
[0052] - Polyester polyols, especially those obtained from the polycondensation of hydroxycarboxylic acids or lactones or from the polycondensation of aliphatic and / or aromatic polycarboxylic acids with di- or polyhydric alcohols. Amorphous, di- or trimer fatty acid-based polyester polyols, such as those commercially available from Croda, for example, are preferred. - Polycarbonate polyols, obtainable, for example, by reacting diols with dialkyl carbonates, diaryl carbonates, or phosgene.
[0053] - Block copolymers containing at least two hydroxyl groups, in particular polyetherpolyesterpolyols.
[0054] - Polyacrylate and polymethacrylate polyols.
[0055] - Polyhydroxy-functional fats or oils, in particular natural fats or oils, such as castor oil, derivatives of castor oil; or polyols obtained by chemical modification of natural fats and oils - so-called oleochemical polyols, such as hydroxylated vegetable oils available under the trade name Sovermol® (from BASF).
[0056] - Polyhydrocarbon polyols, such as, in particular, polyhydroxy-functional polyolefins, polyisobutylenes, polyisoprenes; polyhydroxy-functional ethylene-propylene, ethylene-butylene, or ethylene-propylene-diene copolymers, such as those produced, for example, by Kraton Polymers; polyhydroxy-functional polymers of dienes, in particular of 1,3-butadiene, which may also be produced, in particular, from anionic polymerization; polyhydroxy-functional copolymers of dienes such as 1,3-butadiene or diene mixtures and vinyl monomers such as styrene, acrylonitrile, vinyl chloride, vinyl acetate, vinyl alcohol, isobutylene and isoprene, for example polyhydroxy-functional acrylonitrile / butadiene copolymers, such as those that can be produced from epoxides or amino alcohols and carboxyl-terminated acrylonitrile / butadiene copolymers (for example commercially available under the name Hypro® CTBN or CTBNX or ETBN from Emerald Performance Materials);and hydrogenated polyhydroxy-functional polymers or copolymers of dienes.;
[0057] Polyols that are liquid at room temperature are preferred.
[0058] Preferred are polyols having an OH number in the range from 9 to 115 mg KOH / g, preferably 14 to 60 mg KOH / g, in particular 18 to 40 mg KOH / g.
[0059] Particularly preferred are polyether polyols, di- or trimer fatty acid-based polyester polyols, castor oil, castor oil derivatives, or hydroxylated vegetable oils. Polyether polyols are most preferred. Also suitable as compounds containing two or more aldehyde groups are reaction products of at least one polyisocyanate with at least one hydroxyaldehyde, in particular the aforementioned hydroxyaldehydes.
[0060] Suitable polyisocyanates are in particular oligomeric diisocyanates, in particular 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 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), where "HDI" stands for 1,6-hexane diisocyanate, "IPDI" for isophorone diisocyanate, and "TDI" for 2,4-tolylene diisocyanate or mixtures thereof with 2,6-tolylene diisocyanate. HDI-derived oligomeric diisocyanates, especially HDI biurets, are preferred.
[0061] Preferably, the isocyanate group-containing polymer or the polyisocyanate and the hydroxyaldehyde are reacted in an OH / NCO ratio of 1 / 1 to 1.2 / 1 at a temperature of 40 to 140 °C, preferably 60 to 120 °C, optionally in the presence of a suitable catalyst.
[0062] The curable composition comprises as a component of the second component at least one compound having two or more 1,3-ketoester groups of the formula (I), where R 1 stands for a monovalent hydrocarbon residue with 1 to 6 C atoms.
[0063] Preferably R 1represents methyl, ethyl, propyl, isopropyl, butyl or phenyl. R is particularly preferably 1 for methyl or phenyl.
[0064] Most preferred is R 1 for methyl. Such a 1,3-ketoester group is also called an acetoacetate group.
[0065] Preferably, the compound with two or more 1,3-ketoester groups is liquid at room temperature. In particular, it has a viscosity at 20 °C of 0.01 to 100 Pa s, preferably 0.02 to 50 Pa s, in particular 0.05 to 20 Pa s, measured using a cone-plate viscometer with a cone diameter of 10 mm, a cone angle of 1°, a cone tip-to-plate distance of 0.05 mm, and a shear rate of 10 s -1 , for viscosities of less than 1 Pa s with a cone diameter of 50 mm. Such a compound is easy to handle at ambient temperatures even without the addition of solvents or thinners and enables easy-to-process compositions.
[0066] Preferably, the average functionality of the second component with respect to the compounds containing 1,3-ketoester groups is in the range of 1.6 to 4, preferably 1.8 to 3.5, particularly preferably 2.0 to 3.0. This enables cured compositions with high extensibility, strength, and durability.
[0067] Preferably, the average molecular weight M n the second component with respect to the 1,3-ketoester group-containing compounds in the range of 230 to 10,000 g / mol, preferably 250 to 2,000 g / mol.
[0068] In a preferred embodiment of the invention, the average molecular weight M n of the second component with respect to the 1,3-ketoester group-containing compounds in the range of 500 to 2,000 g / mol. Such a second component enables particularly well-processable compositions of high strength. In a further preferred embodiment of the invention, the average molecular weight Mn of the second component with respect to the 1,3-ketoester group-containing compounds in the range of 2,000 to 10,000 g / mol. In combination with a first component with a similarly high average molecular weight M n With regard to the compounds containing aldehyde groups, such a second component enables compositions with a mixing ratio of the two components in the range of 1:1 in a particularly simple manner, which is particularly advantageous in certain applications, in particular when processed by means of static mixers.
[0069] The second component preferably contains at least one 1,3-ketoester group-containing polymer with an average molecular weight M n from 500 to 10,000 g / mol, preferably 500 to 2,000 g / mol, and an average functionality of 1.8 to 3.5, particularly preferably 2.0 to 3.0, in particular 2.5 to 3.0.
[0070] Preferably, the compound having two or more 1,3-ketoester groups of formula (I) is obtained from the transesterification of at least one 1,3-ketoester of formula (II), where R 2 represents C1-6 alkyl and R 1 has the meanings already mentioned, with at least one polyfunctional alcohol with release and removal of the alcohol of the formula R 2 OH.
[0071] Preferably R 2 stands for methyl, ethyl or tert. butyl, in particular for ethyl.
[0072] The reaction is preferably carried out at a temperature in the range from 50 to 150 °C with distillative removal of the released alcohol R 2OH, optionally under vacuum and optionally in the presence of catalysts. Preferred 1,3-ketoesters of the formula (II) are methyl acetoacetate, ethyl acetoacetate, tert-butyl acetoacetate, ethyl propionyl acetate, ethyl 3-oxohexanoate, ethyl isobutyryl acetate or ethyl benzoyl acetate, especially ethyl acetoacetate.
[0073] It is also possible to prepare a compound with two or more 1,3-ketoester groups by reacting diketene or the adduct of diketene with acetone (= 2,2,6-trimethyl-4H-1,3-dioxin-4-one) with at least one polyfunctional alcohol, whereby in the case of the acetone-diketene adduct acetone is released.
[0074] Suitable polyfunctional alcohols are commercially available compounds or polymers having two or more OH groups, such as in particular 1,2-ethanediol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, diethylene glycol, dipropylene glycol, 1,1,1-trimethylolpropane, glycerol, ethoxylated or in particular propoxylated glycerol, ethoxylated or in particular propoxylated 1,1,1-trimethylolpropane, castor oil, ethoxylated or in particular propoxylated castor oil, ketone resin-modified castor oil, hydroxylated vegetable oils, dimer fatty acid diols or Trimer fatty acid triols, dimer- or trimer fatty acid-based amorphous polyester diols or triols, as well as the other polyols already mentioned above for the production of a polymer containing isocyanate groups, in particular poly(oxy-1,2-propylene)diols or triols or ethylene oxide-endcapped poly(oxy-1,2-propylene)diols or triols.
[0075] Particularly preferred polyfunctional alcohols are 1,2-ethanediol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, 1,4-cyclohexanedimethanol, dipropylene glycol or 1,1,1-trimethylolpropane.
[0076] Furthermore, particularly preferred as a polyfunctional alcohol is propoxylated 1,1,1-trimethylolpropane with an average molecular weight M n from 300 to 1,700 g / mol.
[0077] Furthermore, particularly preferred as polyfunctional alcohols are poly(oxy-1,2-propylene)diols with an average molecular weight M n from 400 to 10,000 g / mol or poly(oxy-1,2-propylene)triols with an average molecular weight M n from 2,000 to 10,000 g / mol, wherein the poly(oxy-1,2-propylene)diols or triols are optionally ethylene oxide endcapped.
[0078] Also particularly preferred as polyfunctional alcohols are dimer fatty acid-based amorphous polyesterdiols or trimer fatty acid-based amorphous polyester triols with an average molecular weight M n from 800 to 3,000 g / mol.
[0079] Particularly preferred compounds containing 1,3-ketoester groups are selected from the group consisting of 1,2-ethanediol bis(acetoacetate), 1,2-propanediol bis(acetoacetate), 1,3-propanediol bis(acetoacetate), 1,4-butanediol bis(acetoacetate), 1,6-hexanediol bis(acetoacetate), 1,4-cyclohexanedimethanol bis(acetoacetate), dipropylene glycol bis(acetoacetate), 1,1,1-trimethylolpropane tris(acetoacetate), glycerol tris(acetoacetate), propoxylated 1,1,1-trimethylolpropane tris(acetoacetate) with medium molecular weight M nfrom 500 to 2,000 g / mol, poly(oxy-1,2-propylene)diol-bis(acetoacetate) with average molecular weight Mn from 600 to 10,000 g / mol, poly(oxy-1,2-propylene)triol-tris(acetoacetate) with average molecular weight M n from 2,000 to 10,000 g / mol, poly(oxy-1,2-propylene)triol tris(acetoacetate) containing ethylene oxide units with medium molecular weight M n from 2,000 to 10,000 g / mol, dimer fatty acid-based polyesterdiol bis(acetoacetate) and trimer fatty acid-based polyestertriol tris(acetoacetate).
[0080] Most preferably, the compounds containing 1,3-ketoester groups comprise a dimer fatty acid-based polyesterdiol diacetoacetate that is liquid at room temperature or a trimer fatty acid-based polyestertriol triacetoacetate that is liquid at room temperature. This enables cured compositions with particularly high extensibility.
[0081] Suitable compounds with two or more acetoacetate groups are also commercially available, in particular as K-Flex® 7301 or K-Flex® XM-B301 (both from King Industries).
[0082] Preferably, the average functionality of the entire composition is
[0083] With respect to the reactive groups, aldehyde and 1,3-ketoester groups, at least 1.9, in particular at least 2.0. This means that a composition with an average aldehyde functionality in the first component of, for example, 1.8 is preferably combined with a second component with an average 1,3-ketoester functionality of at least 2.0, preferably at least 2.1, to achieve an overall average reactive group functionality of 1.9, preferably 2.0.
[0084] Particularly preferably, the curable composition contains as a constituent of the first component at least one urethane group-containing polymer which is liquid at room temperature and has an average molecular weight M n from 1,000 to 20,000 g / mol, preferably 1,500 to 15,000 g / mol, in particular 2,000 to 10,000 g / mol, and an average aldehyde functionality of 1.8 to 3.5, particularly preferably 2.0 to 3.0, in particular 2.2 to 3.0, and as a constituent of the second component at least one acetoacetate group-containing polymer having an average molecular weight M n from 500 to 10,000 g / mol, preferably 500 to 2,000 g / mol, and an average acetoacetate functionality of 1.8 to 3.5, particularly preferably 2.0 to 3.0, in particular 2.5 to 3.0, wherein the average reactive group functionality is preferably at least 1.9 in total, in particular at least 2.0.
[0085] In addition, the first component of the curable composition may contain proportions of low molecular weight polyaldehydes, such as in particular 1,6-hexanedialdehyde, 1,7-heptanedialdehyde, 1,8-octanedialdehyde, 1,9-nonanedialdehyde, 2-methyl-1,8-octanedialdehyde, 1,10-decanedialdehyde, 1,11-undecanedialdehyde, 1,12-dodecanedialdehyde, hexahydrophthalaldehyde, hexahydroisophthalaldehyde, hexahydroterephthalaldehyde, octahydro-4,7-methano-1H-indenedicarbaldehyde, 3,6,9-trioxaundecan-1,11-dial, 1,3-bis-(2,2-dimethyl-3-oxopropyl)imidazolidin-2-one, N,N'-bis(2,2-dimethyl-3-oxopropyl)piperazine, N,N'-bis(2,2-dimethyl-3-oxo-propyl)urea, phthalaldehyde, isophthalaldehyde, terephthalaldehyde, 9,10-anthracenedicarbaldehyde or naphthalenedicarboxaldehyde.
[0086] The curable composition may additionally contain further components, in particular the following: - fillers, in particular ground or precipitated calcium carbonates, which may be coated with fatty acids, in particular stearates, barytes (heavy spars), quartz flours, quartz sands, dolomites, wollastonites, kaolins, 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 blacks, graphite, metal powders, for example of aluminum, copper, iron, silver or steel, PVC powders or hollow spheres;
[0087] - 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;
[0088] - Nanofillers such as graphene or carbon nanotubes;
[0089] - dyes;
[0090] - pigments, in particular titanium dioxide, chromium oxide, iron oxides or organic pigments;
[0091] - 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, benzoates, glycol ethers, glycol esters, plasticizers with a polyether structure, in particular polyoxypropylene monols, diols or triols, or polyoxypropylene monols, diols or -triols with blocked hydroxyl groups, in particular in the form of acetate groups, as well as 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, in particular phthalates, hydrogenated phthalates, adipates or plasticizers with polyether structure;,
[0092] - solvents;
[0093] - Modifiers such as hydrocarbon resins, natural or synthetic waxes or bitumen; - Rheology modifiers, in particular urea compounds, phyllosilicates such as bentonites, castor oil derivatives, hydrogenated castor oil, polyamides, polyurethanes, fumed silicas or hydrophobically modified polyoxyethylenes;
[0094] - drying agents, in particular molecular sieves, calcium oxide, mono-oxazolidines such as Incozol® 2 (from Incorez) or orthoformic acid esters;
[0095] - adhesion promoters, in particular titanates or organoalkoxysilanes such as aminosilanes, mercaptosilanes, epoxysilanes, vinylsilanes, (meth)acrylsilanes, carbamatosilanes, alkylsilanes, S-(alkylcarbonyl)mercaptosilanes or oligomeric forms of these silanes;
[0096] - Catalysts, in particular non-metallic bases such as tertiary amines, in particular 2-dimethylaminoethyl ether, 2,2'-dimorpholinodiethyl ether (DMDEE) or 1,4-diazabicyclo[2.2.2]octane (DABCO), amidines, in particular 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU), 1,5-diazabicyclo[4.3.0]non-5-ene (DBN) or 1-(2-hydroxy-3-(3-trimethoxysilylpropoxy)prop-1-yl)-2-methyl-1,4,5,6-tetrahydropyrimidine, or guanidines, in particular 1,1,3,3-tetramethylguanidine, 1-hexyl-2,3-diisopropylguanidine or 1,1'-( a,®-Polyoxypropylene)bis(2,3-diisopropylguanidine) with medium molecular weight M nof about 250 to 500 g / mol, and in particular basic salts such as in particular potassium acetate, potassium benzoate, potassium carbonate, potassium hydrogen carbonate, potassium phosphates, and the corresponding salts with sodium or lithium instead of potassium, such basic salts preferably being used as aqueous solutions, for example with a concentration of 10 to 30% by weight of the salt based on the total weight of the solution;
[0097] - non-reactive thermoplastic polymers, such as homo- or copolymers of unsaturated monomers, in particular from the group comprising ethylene, propylene, butylene, isobutylene, isoprene, vinyl acetate and alkyl (meth)acrylates, in particular polyethylenes (PE), polypropylenes (PP), polyisobutylenes, ethylene-vinyl acetate copolymers (EVA) and atactic poly-α-olefins (APAO);
[0098] - flame-retardant substances, in particular the fillers already mentioned, such as aluminum hydroxide or magnesium hydroxide, organic phosphoric acid esters, ammonium polyphosphates, melamine or derivatives thereof, boron compounds or antimony compounds; - 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.
[0099] Such additives can be present as part of the first or second component. Substances reactive with 1,3-ketoester groups are preferably part of the first component. Substances reactive with aldehyde groups are preferably part of the second component.
[0100] The curable composition preferably additionally contains at least one further component selected from plasticizers, fillers, and catalysts. The curable composition preferably contains several such further components.
[0101] The curable composition preferably contains at least one basic catalyst with a pKa of at least 8, preferably at least 8.5, in particular a nitrogen-containing compound or an aqueous solution of a basic salt. Such a composition exhibits particularly rapid curing.
[0102] In a preferred embodiment of the invention, the curable composition contains, based on the total composition, 10 to 95% by weight, preferably 20 to 90% by weight, in particular 30 to 80% by weight, of fillers. Preferably, fillers are selected from calcium carbonates, barite, quartz powder, quartz sand, kaolin, aluminum hydroxide, titanium dioxide, and carbon black. Such a composition is particularly suitable for applications in layer thicknesses of at least 1 mm, preferably 1 to 500 mm, in particular 1.5 to 250 mm. The cured composition exhibits pronounced elastic properties.
[0103] In a further preferred embodiment of the invention, the curable composition contains, based on the total composition, 5 to 80% by weight, in particular 10 to 60% by weight, of plasticizer. Plasticizers are preferably selected from DINP, DIDP, DPHP, DINCH, bis(2-ethylhexyl) terephthalate, DINT, bis(2-ethylhexyl) 1,4-cyclohexanedicarboxylate, diisononyl 1,4-cyclohexanedicarboxylate, DOA, polyoxypropylene monols, polyoxypropylene diols, polyoxypropylene triols, polyoxypropylene monol acetates, polyoxypropylene diol diacetates, polyoxypropylene triol triacetates, and DPK.
[0104] In a particularly preferred embodiment of the invention, the curable composition contains fillers and plasticizers, in particular, based on the total composition, 20 to 90% by weight, in particular 30 to 80% by weight, of fillers and 5 to 60% by weight of plasticizer.
[0105] 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 solvents with a boiling point at atmospheric pressure of less than 250°C, based on the total composition. Such a composition causes particularly low emissions.
[0106] The first component of the curable composition is preferably free of aldimine groups or contains only a low aldimine group content of less than 0.2 mol, in particular less than 0.1 mol, of aldimine groups per mole of 1,3-ketoester groups in the second component. This means that the first component is largely free of primary amines. Primary amine groups react with aldehydes to form aldimines. It is not within the scope of the present invention to convert the aldehyde groups in the first component to aldimine groups. The curing of the curable composition according to the invention occurs primarily by reaction of 1,3-ketoester groups with free aldehyde groups.
[0107] Preferably, the curable composition comprises a total of
[0108] - 5 to 100% by weight, preferably 10 to 70% by weight, of the sum of compounds with aldehyde groups or 1,3-ketoester groups of the formula (I),
[0109] - 0 to 50% by weight, preferably 10 to 40% by weight, plasticizer,
[0110] - 0 to 90% by weight, preferably 20 to 80% by weight, fillers, - and optionally other substances, based on the total composition.
[0111] In the curable composition, the ratio of the number of 1,3-ketoester groups to the number of aldehyde groups is preferably in the range of 0.5 to 2.5, particularly preferably 0.8 to 2.2, especially 1 to 2. Such a ratio enables rapid, trouble-free curing to form a mechanically high-quality polymer with high strength, extensibility, and durability. Particularly surprising is the fact that the ratio can be varied within such a wide range, while always yielding a non-sticky material with good mechanical properties. This makes the composition particularly robust with respect to fluctuations in the mixing ratio of the two components during processing.
[0112] The consistency of the first and second components of the curable composition is suitably such that the components can be easily mixed together under ambient conditions using simple methods. Liquid or pasty components are particularly suitable for this purpose.
[0113] The first and second components of the curable composition are prepared separately. The components of each component are mixed together to create a macroscopically homogeneous mass. Each component is stored in a separate container. Suitable containers include a drum, container, hobbock, bucket, canister, can, bag, tubular bag, cartridge, or tube. The components are stable in storage.
[0114] To apply the curable composition, the two components and any additional components present are mixed together shortly before or during application. The mixing ratio is selected such that the ratio of the number of 1,3-ketoester groups to the number of aldehyde groups is within a suitable range, in particular approximately 1 to 2. In parts by weight, the mixing ratio between the first and second components is typically in the range of approximately 100:1 to 1:5, in particular 50:1 to 1:2.
[0115] If the components are mixed together prior to application, care must be taken to ensure that not too much time elapses between mixing the components and application, as otherwise the onset of reaction and the associated increase in viscosity may lead to 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.
[0116] The “open time” is the period of time between the mixing of the components and the end of a state of the composition suitable for processing.
[0117] Mixing is preferably carried out at ambient temperature, in particular at a temperature in the range of -5 to 50°C, in particular 0 to 40°C.
[0118] When the two components are mixed, the composition begins to harden due to the chemical reaction that begins. The 1,3-ketoester groups react primarily with the aldehyde groups, causing the composition to finally harden into a solid, polymeric material. It can be assumed that the curing reaction causes structural units of the
[0119] formula Furthermore, it can be assumed that any additional 1,3-ketoester group present can add to the resulting C=C double bond and thus increase the crosslinking density.
[0120] Curing preferably takes place at ambient temperature, in particular at a temperature in the range of -5 to 50°C, in particular 0 to 40°C. The invention further relates to the cured composition obtained from the curable composition after mixing the two components.
[0121] Preferably, the cured composition is elastic and has high strength and high extensibility.
[0122] Preferably, the cured composition has a tensile strength, determined according to DIN EN 53504 as described in the examples, of at least 1 MPa, preferably at least 1.5 MPa, in particular at least 2 MPa.
[0123] Preferably, the cured composition has an elongation at break, determined according to DIN EN 53504 as described in the examples, of at least 50%, preferably at least 75%, more preferably at least 100%, particularly preferably at least 150%, in particular at least 200%.
[0124] Preferably, the cured composition has a Shore A hardness, determined according to DIN 53505 as described in the examples, in the range from 10 to 90, in particular 20 to 80.
[0125] Furthermore, the cured composition exhibits good heat and water resistance. Preferably, the cured composition exhibits high strength, ductility, and hardness even after storage for 7 days at 100°C or at 70°C and 100% relative humidity.
[0126] The curable composition is suitable for a wide range of applications. It can be used, in particular, as an adhesive, sealant, coating, casting resin, or filler.
[0127] The invention further relates to the use of the curable composition as an elastic adhesive, elastic sealant, or elastic coating, wherein the first and second components, and any additional components present, are mixed together, and the mixed composition is applied in the liquid state to at least one substrate. When used as an elastic adhesive, elastic sealant, or elastic coating, the layer thickness of the cured composition is preferably at least 1 mm, preferably 1 to 50 mm, in particular 1.5 to 25 mm.
[0128] Suitable substrates include:
[0129] - Glass, glass ceramics, concrete, mortar, cement screed, fiber cement, brick, tile, plaster or natural stones such as granite or marble;
[0130] - Repair or levelling compounds based on PCC (polymer-modified cement mortar) or ECO (epoxy resin-modified cement mortar);
[0131] - 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;
[0132] - asphalt or bitumen;
[0133] - 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;
[0134] - 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;
[0135] - 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);
[0136] - insulating foams, in particular made of EPS, XPS, PUR, PIR, rock wool, glass wool, aerogel or foamed glass (foam glass);
[0137] - coated or painted substrates, in particular painted tiles, painted concrete, powder-coated metals or alloys or painted sheets;
[0138] - Coatings, paints or varnishes.
[0139] If necessary, the substrates can be pretreated before application, particularly by physical and / or chemical cleaning processes or the application of an activator or primer. Two similar or different substrates can be bonded and / or sealed.
[0140] An article is obtained from the use of the curable composition. The article is in particular bonded, sealed, or coated with the 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 rotor blade of a wind turbine, 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.
[0141] Examples
[0142] The following are exemplary embodiments intended to further illustrate the described invention. Of course, the invention is not limited to these described exemplary embodiments.
[0143] The “standard climate” (“NK”) is defined as a temperature of 23±1 °C and a relative humidity of 50±5%.
[0144] Unless otherwise stated, the chemicals used were from Sigma-Aldrich Chemie GmbH.
[0145] Description of the measurement methods:
[0146] 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 ) were measured. Viscosities of less than 1 Pa s were measured with a cone diameter of 50 mm.
[0147] Infrared spectra (FT-IR) were measured on undiluted films on a Thermo Scientific Nicolet iS5 FT-IR instrument equipped with a horizontal diamond crystal ATR measurement unit. The absorption bands are given in wavenumbers (cm -1 ) is indicated.
[0148] Production of isocyanate group-containing polymers: Polymer P-1:
[0149] 780 g of ethylene oxide-terminated polyoxypropylenetriol (Desmophen® 5031 BT, OH number 28.0 mg KOH / g, OH functionality approx. 2.3, from Covestro) and 303 g of isophorone diisocyanate (Vestanat® IPDI, from Evonik) were reacted at 80 °C using a known method to form a reaction mixture with an NCO content of 9.1% by weight. The volatile components, particularly unreacted isophorone diisocyanate, were then removed by distillation in a short-path evaporator (jacket temperature 160 °C, pressure 0.1 to 0.005 mbar), yielding a polymer with an NCO content of 1.84% by weight and a monomeric isophorone diisocyanate content of 0.02% by weight.
[0150] Polymer P-2:
[0151] 590 g of polyoxypropylene diol (Acclaim® 4200, OH number 28 mg KOH / g, from Covestro), 1180 g of ethylene oxide-terminated polyoxypropylene triol (Caradol® MD34-02, OH number 35 mg KOH / g, from Shell) and 230 g of isophorone diisocyanate (Vestanat® IPDI, from Evonik) were reacted at 80 °C according to a known method to form a polymer with an NCO content of 2.1 wt%.
[0152] Polymer P-3:
[0153] 818 g of polyoxypropylene diol (Acclaim® 4200, OH number 28.5 mg KOH / g, from Covestro) and 227 g of isophorone diisocyanate (Vestanat® IPDI, from Evonik) were reacted at 80 °C using a known method to form a reaction mixture with an NCO content of 6.6 wt.%. The volatile components, particularly unreacted isophorone diisocyanate, were then removed by distillation in a short-path evaporator (jacket temperature 160 °C, pressure 0.1 to 0.005 mbar), yielding a polymer with an NCO content of 1.91 wt.% and a monomeric isophorone diisocyanate content of 0.03 wt.%.
[0154] Polymer P-4:
[0155] 727.0 g of polyoxypropylenediol (Acclaim® 4200, OH number 28 mg KOH / g, from Covestro) and 273.0 g of 4,4'-diphenylmethane diisocyanate (Desmodur® 44 MC L, from Covestro) were reacted at 80 °C using a known process to form a reaction mixture with an NCO content of 7.6% by weight. The volatile components, particularly unreacted 4,4'-diphenylmethane diisocyanate, were then removed by distillation in a short-path evaporator (jacket temperature 180 °C, pressure 0.1 to 0.005 mbar, condensation temperature 47 °C), yielding a polymer with an NCO content of 1.7% by weight and a monomeric 4,4'-diphenylmethane diisocyanate content of 0.08% by weight.
[0156] Polymer P-5:
[0157] 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 method to form a polymer with an NCO content of 1.5% by weight.
[0158] Polymer P-6:
[0159] 600 g of polyoxypropylene diol (Voranol® 1010 L, OH number 112 mg KOH / g, from Dow) and 533.3 g of isophorone diisocyanate (Vestanat® IPDI, from Evonik) were reacted at 80 °C using a known method to form a reaction mixture with an NCO content of 15.6 wt.%. The volatile components, particularly unreacted isophorone diisocyanate, were then removed by distillation in a short-path evaporator (jacket temperature 160 °C, pressure 0.1 to 0.005 mbar), yielding a polymer with an NCO content of 5.18 wt.% and a monomeric isophorone diisocyanate content of 0.03 wt.%.
[0160] Preparation of compounds with two or more aldehyde groups:
[0161] Connections D-1 to D-7:
[0162] For each compound, the amounts (in parts by weight) of the corresponding isocyanate-containing polymer specified in Table 1 were reacted with the specified amount (in parts by weight) of the corresponding hydroxy-functional aldehyde in the presence of 0.02% by weight of dibutyltin dilaurate at 110 °C under exclusion of moisture until no isocyanate groups were detectable by IR spectroscopy. For the polymers containing aromatic isocyanate groups, P-4 and P-5, the reaction was carried out without dibutyltin dilaurate and at 80 °C. A clear, colorless liquid was obtained in each case. The properties of compounds D-1 to D-7 are listed in Table 1.
[0163] Table 1: Preparation and properties of compounds D-1 to D-7.
[0164] The average molecular weight M nby gel permeation chromatography (GPC) against polystyrene (474 to 2,520,000 g / mol) as a standard with tetrahydrofuran as the mobile phase and a refractive index detector. The average molecular weight M n was 6,100 g / mol.
[0165] Preparation of compounds with two or more 1,3-ketoester groups:
[0166] Connections B-1 to B-5:
[0167] For each compound, the amount (in parts by weight) of the corresponding polyhydric alcohol specified in Table 2 was mixed with the specified amount (in parts by weight) of the corresponding 1,3-ketoester and 0.1 wt% tetra-n-butyl titanate (Tyzor® TnBT, from Dorf Ketal) and reacted under vacuum and with removal of volatiles at a temperature of 140 °C. A clear, colorless liquid was obtained in each case.
[0168] Table 2: Preparation and properties of compounds B-1 to B-5.
[0169] 1 Trimethylolpropane-initiated polyoxypropylenetriol (Desmophen® 4011 T, OH number 550 mg KOH / g, from Covestro)
[0170] 2 amorphous, dimer fatty acid-based polyesterdiol (Priplast® 1837, OH number 115 mg KOH / g, from Croda) Production of curable compositions:
[0171] Examples E-1 to E-29
[0172] For each example, the ingredients of the first component (K1) listed in Tables 3 to 7 were mixed together in the specified amounts (in parts by weight) using a centrifugal mixer (SpeedMixer™ DAC 150, FlackTek Inc.) and stored in a sealed container.
[0173] Likewise, the ingredients of the second component (K2) listed in Tables 3 to 7 were processed and stored.
[0174] Socal® U1S2 (from Imerys), a precipitated and stearate-coated calcium carbonate, was used as the "CaCO3 precipitate." Monarch® 570 (from Cabot) was used as the "carbon black."
[0175] The two components of each composition were then blended into a homogeneous paste using a centrifugal mixer and tested as described below. The setting time was determined by stirring a freshly mixed amount of approximately 3 g at standard conditions with a spatula at regular intervals until the mixture no longer gelled.
[0176] To determine the mechanical properties, the mixed composition was applied to a silicone-coated release paper to form a 2 mm thick film. This film was cured for 7 days under standard climate conditions. Several dumbbell-shaped test specimens with a length of 75 mm, a web length of 30 mm and a web width of 4 mm were punched out of the film and these were tested according to DIN EN 53504 at a tensile speed of 200 mm / min for tensile strength, elongation at break, Young's modulus 5% (at 0.5-5% elongation) and Young's modulus 50% (at 0.5-50% elongation). Furthermore, some test specimens were punched out to determine the tear propagation resistance and tested according to DIN ISO 34-1, method B (angular test specimen) at a tensile speed of 500 mm / min. The Shore A hardness was determined according to DIN 53505 on test specimens cured for 7 days under standard climate conditions. These results are marked with the suffix "7d NK".To determine heat and water resistance, additional Shore A test specimens were cured for 7 days under standard conditions and either stored for an additional 7 days in a convection oven at 100°C or for an additional 7 days at 70°C and 100% relative humidity. After cooling to room temperature, the Shore A hardness was determined as described. These results are designated "+7d 100°C" or "+7d 70 / 100."
[0177] When the examples according to the invention were cured, a non-sticky, elastic material was formed.
[0178] The results are shown in Tables 3 to 7.
[0179] Table 3: Composition and properties of E-1 to E-7.
[0180] 1 1,8-Diazabicyclo[5.4.0]undec-7-ene (Lupragen® N700, from BASF)
[0181] 2 Ratio of the number of acetoacetate groups to aldehyde groups
[0182]
[0183] Table 4: Composition and properties of E-4 and E-8 to E-13. "nb" stands for "not determined."
[0184] 1 1,8-Diazabicyclo[5.4.0]undec-7-ene (Lupragen® N700, from BASF)
[0185] 2 Ratio of the number of acetoacetate groups to aldehyde groups
[0186]
[0187] Table 5: Composition and properties of E-14 to E-21.
[0188] 1 1,8-Diazabicyclo[5.4.0]undec-7-ene (Lupragen® N700, from BASF)
[0189] 2 Ratio of the number of acetoacetate groups to aldehyde groups
[0190]
[0191] Table 6: Composition and properties of E-4, E-15 and E-22 to E-25.
[0192] "nb" stands for "not determined"
[0193] 1 1,8-Diazabicyclo[5.4.0]undec-7-ene (Lupragen® N700, from BASF)
[0194] 2 Ratio of the number of acetoacetate groups to aldehyde groups
[0195]
[0196] Table 7: Composition and properties of E-26 to E-29.
[0197] 1 1,8-Diazabicyclo[5.4.0]undec-7-ene (Lupragen® N700, from BASF)
[0198] 2 Ratio of the number of 1,3-ketoester groups to aldehyde groups
Claims
Patent claims: 1 . Curable composition comprising - a first component containing aldehyde group-containing compounds comprising at least one compound having two or more aldehyde groups and - a second component containing 1,3-ketoester group-containing compounds comprising at least one compound having two or more 1,3-ketoester groups of the formula (I), OO-0A R1 <'> where R 1 represents a monovalent hydrocarbon radical having 1 to 6 C atoms, where the average molecular weight M n at least one of the two components with respect to the aldehyde or 1,3-ketoester group-containing compounds is in the range of 400 to 20,000 g / mol.
2. Composition according to claim 1, characterized in that it contains less than 10% by weight, preferably less than 5% by weight, in particular less than 2% by weight, of water based on the total composition.
3. Composition according to one of claims 1 or 2, characterized in that the compound having two or more aldehyde groups is liquid at room temperature, in particular with a viscosity at 20 °C of from 0.2 to 700 Pa s, preferably 0.3 to 500 Pa s, particularly preferably 0.5 to 200 Pa s, measured by means of a cone-plate viscometer with a cone diameter of 10 mm, cone angle of 1 °, cone tip-plate distance of 0.05 mm, shear rate of 10 s -1 , for viscosities of less than 1 Pa s with cone diameter 50 mm.
4. Composition according to one of claims 1 to 3, characterized in that the average molecular weight M n the first component in Based on the aldehyde-containing compounds, the molecular weight is in the range from 1,000 to 20,000 g / mol, preferably 1,500 to 15,000 g / mol, in particular 2,000 to 10,000 g / mol, measured by gel permeation chromatography (GPC) against polystyrene as standard. Composition according to one of claims 1 to 4, characterized in that the aldehyde-containing compounds comprise a polymer having a polymer backbone containing poly(oxyalkylene) units and / or polyester units. Composition according to one of claims 1 to 5, characterized in that the aldehyde-containing compounds comprise a urethane-containing polymer which is liquid at room temperature and has an average molecular weight M nfrom 1,000 to 20,000 g / mol, preferably 1,500 to 15,000 g / mol, in particular 2,000 to 10,000 g / mol, and an average aldehyde functionality of 1.8 to 3.5, preferably 2.0 to 3.0, in particular 2.2 to 3.
0. Composition according to one of claims 1 to 6, characterized in that in the 1,3-ketoester groups of the formula (I) R 1 represents methyl, ethyl, propyl, isopropyl, butyl or phenyl, preferably methyl or phenyl, in particular methyl. Composition according to one of claims 1 to 7, characterized in that the average functionality of the second component with respect to the 1,3-ketoester group-containing compounds is in the range from 1.6 to 4, preferably 1.8 to 3.5, particularly preferably 2.0 to 3.
0. Composition according to one of claims 1 to 8, characterized in that the average molecular weight M nthe second component with respect to the 1,3-ketoester group-containing compounds is in the range of 230 to 10,000 g / mol, preferably 250 to 2,000 g / mol. Composition according to one of claims 1 to 9, characterized in that, based on the total composition, 10 to 95% by weight, preferably 20 to 90% by weight, in particular 30 to 80% by weight, of fillers are present. Composition according to one of claims 1 to 10, characterized in that, based on the total composition, 5 to 80% by weight, in particular 10 to 60% by weight, of plasticizers are present. Composition according to one of claims 1 to 11, characterized in that, based on the total composition, less than 10% by weight, preferably less than 5% by weight, in particular less than 1% by weight, of volatile organic solvents having a boiling point at atmospheric pressure of less than 250°C are present.A cured composition obtained from the curable composition according to any one of claims 1 to 12 after mixing the two components, wherein the cured composition has in particular a tensile strength of at least 1 MPa, preferably at least 1.5 MPa, in particular at least 2 MPa, and / or an elongation at break of at least 75%, preferably at least 100%, in particular at least 150%, determined according to DIN EN 53504 at a tensile speed of 200 mm / min on dumbbell-shaped test specimens with a thickness of 2 mm and a length of 75 mm, a web length of 30 mm and a web width of 4 mm. Use of the composition according to any one of claims 1 to 12 as an elastic adhesive, elastic sealant or elastic coating, wherein the first and the second and any further components present are mixed with one another and the mixed composition is applied in the liquid state to at least one substrate. Use according to claim 14, wherein the cured composition has a layer thickness of at least 1 mm, preferably 1 to 50 mm, in particular 1.5 to 25 mm.