Polymers having aldehyde groups

Abstract

The present invention relates to a non-ionic aldehyde-functional polymer having end groups of formula (I) and having an average content of aldehyde groups of 0.15 to 1.2 meq / g. The polymers are suitable for cross-linking compounds having reactive groups, such as, in particular, cyanoacetate, acetoacetate or malonate groups, at ambient temperatures. The invention relates to a polymer which enables fast curing while having particularly long processing times, and which has particularly high tensile strength and tear propagation resistance at high ductility. It is therefore suitable as a component of elastic adhesives, sealants or coatings, which are essentially free of toxic components and less sensitive to moisture and bubble formation, can be particularly well processed, and are particularly robust and long-life.

Description

Technical Field

[0001] The invention relates to polymers having aldehyde groups and their use for curing compounds having reactive groups, such as, in particular, cyanoacetate, acetoacetate or malonate groups, and to adhesives, sealants or coatings obtainable therefrom which are curable at room temperature. Prior art

[0002] Reactive polymer compositions that are curable at room temperature and can be used as adhesives, sealants or coatings with elastic properties are known. Polyurethane systems that are cured and form particularly high elastic polymers by the reaction of isocyanate groups with polyols and / or moisture are widely used. However, they are sensitive to the formation of bubbles due to excessive moisture during the curing process, and the polyisocyanates used for this purpose are generally toxic compounds. Reactive polymer compositions based on silane-functional polymers (SMP / STP) and silicones are also widely used. In the process of its curing, alcohols, particularly methanol or ethanol, or oximes are released, which are toxic and cause VOC emissions, and they generally contain a large amount of low molecular weight silanes in addition, which are equally harmful to health. Also known are water-based polymer systems, which are generally based on acrylate dispersions or polyurethane dispersions. These are cured by the evaporation and coalescence of water, and are substantially free of chemically reactive groups. However, they can only be used in relatively thin layers and are only used between open-cell substrates, and the curing rate is highly dependent on ambient humidity, and they have high shrinkage. After curing, water sensitivity is increased due to the inclusion of surfactants required for the production and stability of the dispersion, which can lead to reduced durability, especially in outdoor applications. Summary of the invention

[0003] It is an object of the present invention to provide a functional polymer which can be crosslinked together with a compound having suitable reactive groups and which enables the realization of a room temperature curable composition having elasticity which overcomes the disadvantages of the prior art.

[0004] This object is surprisingly achieved by nonionic aldehyde-functional polymers according to claim 1. The aldehyde-functional polymers according to the invention having end groups of the formula (I) are insensitive to moisture and bubble formation, have extremely low toxicological problems, do not require hazard marking, and can be handled without special precautions. The polymers according to the invention are particularly suitable for the crosslinking of compounds having reactive groups, such as, in particular, cyanoacetate groups, 1,3-ketoester groups or malonate groups, and such polymer systems have good processability and do not require organic solvents for dissolving or diluting, or water for emulsifying or dispersing the components. They cure surprisingly rapidly and without defects under ambient conditions, independently of humidity, without causing emissions, and the curing rate can be very well controlled using conventional catalysts, in particular non-metallic bases such as tertiary amines, amidines or guanidines. Curing produces non-sticky, elastic polymers of high strength and ductility, as well as good stability to heat and water.

[0005] The polymers according to the invention enable particularly high-quality elastic adhesives, sealants or coatings which overcome the disadvantages of the prior art with regard to toxic components, sensitivity to moisture and stability as well as robustness after curing.

[0006] Further aspects of the invention are the subject matter of further independent claims. Particularly preferred embodiments of the invention are the subject matter of the dependent claims.

[0007] Specific embodiments of the present invention

[0008] The present invention provides nonionic aldehyde-functional polymers having terminal groups of formula (I),

[0009]

[0010] and it has an average content of aldehyde groups of 0.15 to 1.2 meq / g, preferably 0.2 to 0.75 meq / g, more preferably 0.2 to 0.7 meq / g, especially 0.3 to 0.6 meq / g,

[0011] in

[0012] R is a divalent organic group having 1 to 15 carbon atoms, and

[0013] D is a divalent hydrocarbon group having 4 to 15 carbon atoms.

[0014] “Nonionic” polymers are polymers having a content of less than 0.05% by weight, in particular less than 0.01% by weight, based on the polymer, of ionic groups, the ionic groups being selected in particular from carboxylate groups, ammonium groups and sulfonate groups.

[0015] "Room temperature" refers to a temperature of 23°C.

[0016] The dashed lines in the formulae here represent in each case the bond between a substituent and the remainder of the molecule to which it belongs.

[0017] "Molecular weight" refers to the molar mass of a molecule (g / mole). "Average molecular weight" refers to the number average molecular weight (Mn) of a polydisperse mixture of oligomer or polymer molecules. It is determined by gel permeation chromatography (GPC) using polystyrene as a standard.

[0018] Substance names beginning with "poly", such as polyol, polyisocyanate, polycyanoacetate or polyacetoacetate, refer to substances that formally contain two or more of the functional groups appearing in their names per molecule.

[0019] A "storage-stable" substance or composition is one that can be stored in a suitable container at room temperature for a long period of time, generally at least 3 months to 6 months or longer, without such storage resulting in a change in its application or use properties to an extent relevant to its use.

[0020] All industry standards and specifications mentioned in this document refer to the versions effective on the date of initial submission.

[0021] Unless otherwise indicated, weight percent (% wt) refers to the mass proportion of a component of a composition or molecule, based on the entire composition or the entire molecule. The terms "mass" and "weight" are used synonymously herein.

[0022] The aldehyde-functional polymers preferably have an average molecular weight Mn of 1500 to 20 000 g / mol, preferably 2500 to 15 000 g / mol, in particular 3500 to 8000 g / mol, measured by gel permeation chromatography (GPC) relative to polystyrene as standard.

[0023] Preferably, the aldehyde-functional polymer has an average aldehyde functionality of from 1.8 to 4, preferably from 2.0 to 3, especially from 2.2 to 3.0.

[0024] Preferably, the aldehyde-functional polymer contains less than 20% by weight, in particular less than 15% by weight, of oxyethylene units, based on the total polymer. Such polymers are particularly stable to moisture.

[0025] Preferably, R in formula (I) is a linear or branched alkyl group, cycloalkylene group, arylalkylene group or aryl group, which may also contain oxygen and / or nitrogen atoms.

[0026] In particular, the R group is selected from methylene, propane-1,2-diyl, 2-methylpropane-1,2-diyl, butane-1,4-diyl, 2-oxabutane-1,4-diyl, 3-oxapentane-1,5-diyl,

[0027] Among them, preferred

[0028] Particularly preferred is Such polymers are derived from 5-hydroxymethylfurfural, which is obtainable from renewable raw materials. These polymers have particularly low viscosity and impart high strength, ductility, tear propagation strength and heat and water resistance to the curable compositions.

[0029] Preferably, D in formula (I) is a divalent group after removing two amino groups from hexane-1,6-diamine, 2,2(4),4-trimethylhexane-1,6-diamine, 1-methyl-2,4(6)-diaminocyclohexane, isophoronediamine, 4,4'-diaminodicyclohexylmethane, diphenylmethane-4(2),4'-diamine or toluene-2,4(6)-diamine.

[0030] More preferably, D is a divalent radical of hexane-1,6-diamine or isophoronediamine after removal of the two amino groups, especially a radical of isophoronediamine after removal of the two amino groups. Such aldehyde-functional polymers have a particularly low viscosity.

[0031] Preferably, R in the terminal group of formula (I) and in the compound of formula (II) are the same group.

[0032] Preferably, the aldehyde-functional polymer has a polymer backbone comprising poly(oxyalkylene) units and / or polyester units.

[0033] In particular, the aldehyde-functional polymer has a poly(oxyalkylene) backbone.

[0034] Preferred poly(oxyalkylene)s are poly(oxy-1,2-propylene), mixed poly(oxy-1,2-propylene)(oxyethylene), poly(oxy-1,3-propylene), poly(oxy-1,4-butylene), poly(oxy-1,2-butylene) or mixed forms of these poly(oxyalkylene)s.

[0035] Among these, poly(oxy-1,2-propylene), poly(oxy-1,3-propylene) or poly(oxy-1,4-butylene), in particular poly(oxy-1,2-propylene), may contain 0-25% by weight, preferably 0-20% by weight, of poly(oxyethylene) units based on a poly(oxyalkylene) backbone, especially at the chain ends. Aldehyde-functional polymers with such backbones have low viscosity and are therefore particularly efficiently processable and particularly hydrophobic. They give compositions having particularly good processability, high ductility and good water resistance.

[0036] Preferred polymer backbones containing polyester units are esters of dicarboxylic acids and diols or triols, and triglycerides, especially esters of dimerized fatty acids or derivatives derived from castor oil, castor oil or vegetable oils.

[0037] The aldehyde-functional polymer preferably has a content of a compound of formula (II)

[0038]

[0039] The content is less than 1% by weight, preferably less than 0.5% by weight, in particular less than 0.2% by weight, based on the polymer, wherein R and D have the definitions given above. Such aldehyde-functional polymers surprisingly allow fast curing with particularly long processing times and particularly high tensile strength and tear propagation strength at high ductility, so that such polymer systems have particularly good processability and are particularly robust and long-lived.

[0040] More preferably, the aldehyde functional polymer has a poly(oxyalkylene) backbone wherein R is And D is the radical of isophorone diisocyanate after removal of two isocyanate groups.

[0041] Preferably, the aldehyde-functional polymer is substantially free of acid groups. Preferably, the acid group content is less than 0.1% by weight, based on the polymer. Such polymers are particularly hydrophobic and can impart good water resistance to the cured composition.

[0042] The aldehyde-functional polymer is preferably liquid at room temperature. In particular, it has a sufficiently low viscosity so that it flows freely even without any significant heating and can therefore be easily transported, filled and compounded.

[0043] Preferably, the viscosity of the aldehyde-functional polymer at 20° C. is 1 to 500 Pa·s, preferably 2 to 200 Pa·s, and especially 5 to 100 Pa·s, which is obtained by a cone diameter of 10 mm, a cone angle of 1°, a cone tip-plate distance of 0.05 mm, and a shear rate of 10 s -1 Cone and plate viscometer measurement.

[0044] The aldehyde-functional polymer is preferably the reaction product of at least one hydroxyaldehyde of the formula HO—R—CHO and at least one polymer containing isocyanate groups.

[0045] The reaction is preferably carried out at an OH / NCO ratio of at least 1, at a temperature of from 40 to 140° C., preferably from 60 to 120° C., optionally in the presence of a suitable catalyst and optionally in the presence of a plasticizer.

[0046] The aldehyde-functional polymer preferably contains no isocyanate groups.

[0047] Suitable hydroxyaldehydes are especially 2-hydroxyacetaldehyde, 3-hydroxybutyraldehyde, 3-hydroxypivalaldehyde, 5-hydroxyvaleraldehyde, 2-(2-hydroxyethoxy)acetaldehyde, 3-(2-hydroxyethoxy)propionaldehyde, 5-hydroxymethylfurfural, alkoxylated o-, m- or p-hydroxybenzaldehyde or alkoxylated vanillin, where “alkoxylated” preferably means (mono- or poly-) “ethoxylated” or “propoxylated”, and also 4,4′-(2-hydroxypropane-1,3-diyl)bis(oxy)bis(benzaldehyde) or 4,4′-(2-hydroxypropane-1,3-diyl)bis(oxy)bis(3-methoxybenzaldehyde).

[0048] Preferred are 5-hydroxymethylfurfural, ethoxylated salicylaldehydes, especially 2-(2-hydroxyethoxy)benzaldehyde, or ethoxylated vanillins, especially 4-(2-hydroxyethoxy)-3-methoxybenzaldehyde. These hydroxyaldehydes are obtainable by simple processes and give aldehyde-functional polymers of low viscosity.

[0049] Particularly preferred is 5-hydroxymethylfurfural. This hydroxyaldehyde is obtainable from renewable raw materials and enables particularly low-viscosity polymers.

[0050] The isocyanate group-containing polymer preferably has a monomeric diisocyanate of the formula OCN-D-NCO in an amount of less than 0.5% by weight, preferably less than 0.2% by weight, in particular less than 0.1% by weight, based on the isocyanate group-containing polymer. Such polymers enable particularly low contents of compounds of the formula (II).

[0051] Suitable polymers containing isocyanate groups for reaction with hydroxyaldehydes of the formula HO-R-CHO are in particular the reaction products of at least one monomeric diisocyanate of the formula OCN-D-NCO with at least one polymeric polyol in an NCO / OH ratio of 3 / 1 to 10 / 1, and the monomeric diisocyanate is subsequently removed by suitable separation methods to a content of less than 0.5% by weight, preferably less than 0.2% by weight, in particular less than 0.1% by weight, based on the polymer.

[0052] The polymer containing isocyanate groups preferably has an NCO content of 0.6% to 6% by weight, more preferably 0.9% to 3.5% by weight and in particular 1.3% to 2.7% by weight, based on the polymer.

[0053] Preferably, the average NCO functionality of the polymer containing isocyanate groups is from 1.8 to 4, preferably from 2 to 3, in particular from 2.2 to 3.0.

[0054] Suitable diisocyanates of the formula OCN-D-NCO are in particular hexane-1,6-diisocyanate (HDI), 2,2(4),4-trimethylhexane-1,6-diisocyanate (TMDI), 1-methyl-2,4(6)-diisocyanatocyclohexane (H6TDI), isophorone diisocyanate (IPDI), 4,4'-diisocyanatodicyclohexylmethane (H 12 MDI), 4(2),4'-diphenylmethane diisocyanate (MDI) or toluene 2,4(6)-diisocyanate (TDI). HDI or IPDI is preferred, and IPDI is particularly preferred.

[0055] Preferred polymer polyols are polymers having an OH value of 9 to 114 mg KOH / g, preferably 12 to 57 mg KOH / g, in particular 18 to 45 mg KOH / g, and whose polymer backbone contains poly(oxyalkylene) units and / or polyester units.

[0056] Particular preference is given to poly(oxyalkylene) polyols, castor oil, hydroxy-functional derivatives of castor oil, hydroxylated vegetable oils or polyester polyols based on dimerized or trimerized fatty acids or polyols having poly(oxyalkylene) and polyester units.

[0057] Most preferred are poly(oxyalkylene) polyols.

[0058] Preferred poly(oxyalkylene) polyols, also called polyether polyols, are especially the 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, wherein these can be polymerized with the aid of starter molecules having two or more active hydrogen atoms, such as in particular water, ammonia or compounds having a plurality of OH or NH groups, for example ethane-1,2-diol, propylene oxide or 1,2- or 2,3-butylene oxide or oxetane or tetrahydrofuran or mixtures thereof. 1,2- or 1,3-diol, neopentyl glycol, diethylene glycol, triethylene glycol, isomeric dipropylene glycol or tripropylene glycol, isomeric butanediols, pentanediol, hexanediol, heptanediol, octanediol, nonanediol, decanediol, undecanediol, cyclohexane-1,3- or 1,4-dimethanol, bisphenol A, hydrogenated bisphenol A, 1,1,1-trimethylolethane, 1,1,1-trimethylolpropane, glycerol or aniline, or mixtures thereof.

[0059] Particularly preferred are poly(oxy-1,2-propylene) diols, poly(oxy-1,2-propylene) triols or so-called ethylene oxide-terminated (EO-terminated or EO-terminated) poly(oxy-1,2-propylene) 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 the propoxylation reaction is complete, and thus they ultimately have primary hydroxyl groups.

[0060] Also particularly preferred are poly(oxy-1,3-propylene) glycol or poly(oxy-1,4-butylene) glycol.

[0061] Preference is given to polyols having an unsaturation of less than 0.02 meq / g, especially less than 0.01 meq / g.

[0062] The compound of formula (II) is obtained by the reaction of monomeric diisocyanates contained in the isocyanate group-containing polymer with hydroxyaldehydes of the formula HO-R-CHO. The low monomeric diisocyanate content in the isocyanate group-containing polymer leads to an advantageously low content of the compound of formula (II) of less than 1% by weight, preferably less than 0.5% by weight, in particular less than 0.2% by weight, based on the polymer.

[0063] The aldehyde-functional polymers of the invention can be used particularly advantageously for curing compounds having at least two reactive groups reactive toward aldehydes to form cured compositions having elastic properties. Low contents of compounds of formula (II) enable particularly long processing times and rapid curing as well as particularly high tensile strength and tear propagation strength and high ductility.

[0064] The present invention therefore further provides for the use of aldehyde-functional polymers for curing at least one compound V having at least two reactive groups which are reactive toward aldehydes.

[0065] These reactive groups are preferably selected from cyanoacetate groups, 1,3-ketoester groups and malonate groups.

[0066] Compound V is preferably liquid at room temperature. In particular, its viscosity at 20°C is 0.1-100 Pa·s, preferably 0.2-50 Pa·s, especially 0.5-20 Pa·s, which is determined by a cone diameter of 10 mm, a cone angle of 1°, a cone tip-plate distance of 0.05 mm, a shear rate of 10 s -1 The viscosity is measured by a cone-plate viscometer and a ball diameter of 50 mm is used for viscosities less than 1 Pa·s. Such compounds enable curable compositions having good processability at ambient temperature and without the need for the addition of solvents or diluents.

[0067] Compound V preferably has 2 to 4 of the reactive groups mentioned.

[0068] Compound V preferably has only a low water content, in particular up to 10% by weight of water, based on compound V. Such nonaqueous compounds impart particularly good weathering stability to the cured composition.

[0069] Curing is preferably carried out at ambient temperature, in particular at a temperature of from -5 to 50°C, preferably from 0 to 40°C.

[0070] More preferably, compound V has at least two cyanoacetate groups. This results in cured compositions having particularly good mechanical properties, in particular high ductility and tear propagation strength.

[0071] For curing of at least one compound V having cyanoacetate groups, the aldehyde-functional polymer is preferably used in such an amount that the ratio of the number of cyanoacetate groups to the number of aldehyde groups is in the range from 0.7 to 1.5, preferably 0.8 to 1.2, in particular 0.9 to 1.1. Particularly suitable compounds V having cyanoacetate groups are selected from the group consisting of ethane-1,2-diol bis(cyanoacetate), propane-1,2-diol bis(cyanoacetate), propane-1,3-diol bis(cyanoacetate), butane-1,4-diol bis(cyanoacetate), hexane-1,6-diol bis(cyanoacetate), cyclohexane-1,4-dimethanol bis(cyanoacetate), dipropylene glycol bis(cyanoacetate), 1,1,1-trimethylolpropane tris(cyanoacetate), glycerol tris(cyanoacetate), propoxylated 1,1,1-trimethylolpropane tris(cyanoacetate) having an average molecular weight Mn of 500 to 2000 g / mol, poly(oxy-1,2-propylene)diol bis(cyanoacetate) having an average molecular weight Mn of 2000 to 10000 g / mol, The invention also includes the following: polyester triol tris(cyanoacetate) containing ethylene oxide units and having an average molecular weight Mn of 2000 to 10000 g / mol, poly(oxy-1,2-propylene) triol tris(cyanoacetate) having an average molecular weight Mn of 2000 to 10000 g / mol, poly(oxy-1,2-propylene) diol bis(cyanoacetate) containing ethylene oxide units and having an average molecular weight Mn of 2000 to 10000 g / mol, polyester diol bis(cyanoacetate) based on dimer fatty acids having an average molecular weight Mn of 1000 to 4000 g / mol, and polyester triol tris(cyanoacetate) based on trimer fatty acids having an average molecular weight Mn of 1000 to 4000 g / mol.

[0072] Such compounds V having cyanoacetate groups are obtained in particular from the transesterification of at least one cyanoacetate of the formula (III) with at least one polyfunctional alcohol, with simultaneous release and removal of a cyanoacetate of the formula R 1 -OH alcohol.

[0073] Where R 1 It is C 1-6 alkyl.

[0074] Preferably, R 1 This is methyl, ethyl or tert-butyl, especially ethyl.

[0075] Further preferably, compound V has at least two 1,3-ketoester groups, preferably at least two 1,3-ketoester groups of the formula (IV), in particular at least two acetoacetate groups.

[0076]

[0077] In formula (IV), R 2 is a monovalent hydrocarbon radical having 1 to 6 carbon atoms, preferably methyl, ethyl, propyl, isopropyl, butyl or phenyl, especially methyl.

[0078] For curing the at least one compound V having 1,3-ketoester groups, the aldehyde-functional polymer is preferably used in an amount such that the ratio of the number of 1,3-ketoester groups to the number of aldehyde groups is in the range from 0.5 to 2.5, more preferably from 0.8 to 2.2, in particular from 1 to 2.

[0079] Particularly suitable compounds V having 1,3-ketoester groups are selected from ethane-1,2-diol bis(acetoacetate), propane-1,2-diol bis(acetoacetate), propane-1,3-diol bis(acetoacetate), butane-1,4-diol bis(acetoacetate), hexane-1,6-diol bis(acetoacetate), cyclohexane-1,4-dimethanol bis(acetoacetate), dipropylene glycol bis(acetoacetate), 1,1,1-trimethylolpropane tris(acetoacetate), glycerol tris(acetoacetate), propoxylated 1,1,1-trimethylolpropane tris(acetoacetate) with an average molecular weight Mn of 500 to 2000 g / mol. Trimethylolpropane tris(acetoacetate), poly(oxy-1,2-propylene)diol bis(acetoacetate) having an average molecular weight Mn of 600 to 10000 g / mol, poly(oxy-1,2-propylene)triol tris(acetoacetate) having an average molecular weight Mn of 2000 to 10000 g / mol, poly(oxy-1,2-propylene)triol tris(acetoacetate) containing ethylene oxide units and having an average molecular weight Mn of 2000 to 10000 g / mol, dimerized fatty acid-based polyester diol bis(acetoacetate) and trimerized fatty acid-based polyester triol tris(acetoacetate).

[0080] Such compounds V having 1,3-ketoester groups are obtained in particular from the transesterification of at least one 1,3-ketoester of the formula (V) with at least one polyfunctional alcohol, with simultaneous release and removal of a 1,3-ketoester of the formula R 4 OH alcohol,

[0081]

[0082] Where R 3 is a monovalent hydrocarbon group having 1 to 6 carbon atoms and R 4 It is C 1-6 alkyl.

[0083] Preferably, R 3 is methyl, ethyl, propyl, isopropyl, butyl or phenyl, preferably methyl or phenyl, especially methyl, and R 4 is methyl, ethyl or tert-butyl, especially ethyl.

[0084] Compounds V having 1,3-ketoester groups are also obtained by reaction of diketene or an adduct of diketene and acetone (=2,2,6-trimethyl-4H-1,3-dioxin-4-one) with at least one polyfunctional alcohol, wherein in the case of the acetone-diketenoid adduct, acetone is liberated.

[0085] Further preferably, compound V has at least two malonate groups, especially of the formula of malonate groups.

[0086] For curing of at least one compound V having malonate groups, the aldehyde-functional polymer is preferably used in such an amount that the ratio of the number of malonate groups to the number of aldehyde groups is in the range from 0.5 to 2.5, more preferably from 0.8 to 2.2 and in particular from 1 to 2.

[0087] Particularly suitable compounds V having malonate groups are selected from the group consisting of ethane-1,2-diol bis(ethyl malonate), propane-1,2-diol bis(ethyl malonate), propane-1,3-diol bis(ethyl malonate), butane-1,4-diol bis(ethyl malonate), hexane-1,6-diol bis(ethyl malonate), cyclohexane-1,4-dimethanol bis(ethyl malonate), diethylene glycol bis(ethyl malonate), dipropylene glycol bis(ethyl malonate), glycerol tri(ethyl malonate), 1,1,1-trimethylolpropane tri(ethyl malonate), dimer fatty acid diol bis(ethyl malonate), trimer fatty acid triol tri(ethyl malonate), esters), castor oil tris(ethyl malonate), poly(oxy-1,2-propylene)diol bis(ethyl malonate) having an average molecular weight Mn of 500 to 2000 g / mol, propoxylated 1,1,1-trimethylolpropane having three ethyl malonate end groups and an average molecular weight Mn of 650 to 2500 g / mol, the corresponding oligomeric compounds of these reaction products and polyester diols containing malonate groups from the reaction of diols such as hexane-1,6-diol or cyclohexane-1,4-dimethanol with malonic acid or diethyl malonate and optionally other dicarboxylic acids or esters thereof, such as in particular adipic acid or diethyl adipic acid or dimer fatty acids.

[0088] Suitable compounds V having malonate groups are obtained in particular from the reaction of at least one polyfunctional alcohol with malonic acid or at least one malonate of the formula (VI):

[0089]

[0090] Where R 5 and R 6 Each is an alkyl group having 1 to 6 carbon atoms.

[0091] Preferably, R 5 and R 6 Each is methyl, ethyl or isopropyl, especially ethyl.

[0092] Preferred malonic esters of formula (VI) are dimethyl malonate, diethyl malonate, diisopropyl malonate, butyl ethyl malonate, tert-butyl ethyl malonate or di-tert-butyl malonate. Particular preference is given to dimethyl malonate, diethyl malonate or diisopropyl malonate, especially diethyl malonate.

[0093] Suitable polyfunctional alcohols for reaction with the cyanoacetic acid esters of the formula (III) or the 1,3-ketoesters of the formula (V) or the malonic esters of the formula (VI) are commercially available compounds or polymers having two or more OH groups, such as, in particular, ethane-1,2-diol, propylene glycol, butane-1,4-diol, pentane-1,5-diol, hexane-1,6-diol, cyclohexane-1,3-dimethanol, cyclohexane-1,4-dimethanol, diethylene glycol, dipropylene glycol, 1,1,1- Trimethylolpropane, glycerol, ethoxylated or especially propoxylated glycerol, ethoxylated or especially propoxylated 1,1,1-trimethylolpropane, castor oil, ethoxylated or especially propoxylated castor oil, ketone resin-modified castor oil, poly(oxy-1,2-propylene) diols or triols, ethylene oxide-terminated poly(oxy-1,2-propylene) diols or triols, dimerized fatty acid diols or trimerized fatty acid triols or dimerized or trimerized fatty acid-based polyester diols or triols.

[0094] Compounds V having malonate groups can also be obtained by reacting malonic acid with polyfunctional alcohols having an excess of OH groups. The stoichiometry in this reaction is preferably 2.2 to 3.5, preferably 2.3 to 3.3, molar equivalents of OH groups of the polyfunctional alcohol per mole of malonic acid. In this reaction, other dicarboxylic acids, such as adipic acid, can also be used.

[0095] Likewise possible are compounds V having mixed reactive groups, ie for example compounds V having at least one cyanoacetate group and at least one acetoacetate group, or at least one cyanoacetate group and at least one malonate group, or at least one acetoacetate group and at least one malonate group.

[0096] Preference is given to using aldehyde-functional polymers for curing at least one compound V as a constituent of a two-component composition, wherein the first component comprises the aldehyde-functional polymer according to the invention and the second component comprises the compound V, wherein the first and second components are themselves storage-stable and are stored in separate containers until they are mixed with one another shortly before or during application.

[0097] The two-component composition may additionally contain further ingredients, in particular fillers, fibers, nanofillers such as graphene or carbon nanotubes, dyes, pigments, plasticizers, solvents, rheology modifiers, adhesion promoters such as, in particular, titanates or organoalkoxysilanes, catalysts, in particular non-metallic bases such as tertiary amines, amidines or guanidines, or basic salts such as, in particular, potassium acetate, potassium benzoate, potassium carbonate or sodium acetate, in particular as an aqueous solution, or flame retardants, additives such as, in particular, wetting agents, leveling agents, defoamers, deaerators or stabilizers against oxidation, heat, light or UV radiation, or other substances typically used in curable compositions.

[0098] These additives can be present as a component of the first or second component. The substance reactive with aldehyde groups is preferably a component of the second component.

[0099] The composition preferably additionally contains at least one further ingredient selected from plasticizers, fillers and catalysts. In particular, it comprises several of these further ingredients.

[0100] The composition preferably contains less than 10%, more preferably less than 5% and in particular less than 1% by weight of volatile organic solvents having a boiling point below 250° C. at standard pressure, based on the total composition. Such compositions lead to particularly low emission levels.

[0101] The consistency of the first component and the second component is suitable for making the components can be well mixed with each other by simple methods under ambient conditions. For this purpose, liquid or pasty components are particularly suitable.

[0102] For application, the two components and any other components present are mixed with one another shortly before or during application. The mixing ratio is selected so that the ratio of the reactive groups is within a suitable range. The mixing ratio between the first and second components is generally in the range of about 100:1 to 1:5, in particular 50:1 to 1:2, based on parts by weight.

[0103] If the components are mixed with one another before application, it must be ensured that not too much time elapses between mixing of the components and application, since otherwise the onset of reaction and the associated increase in viscosity can lead to problems such as inadequate leveling or delayed or incomplete adhesion to the substrate.

[0104] The term "processing time" is used here to mean the time interval between mixing the components and the end of a state in which the composition is suitable for processing. Long processing times are particularly advantageous in the case of subsequent rapid curing.

[0105] Mixing and curing are preferably carried out at ambient temperature.

[0106] As the two components are mixed, the composition begins to cure by an initial chemical reaction. Mainly the aldehyde groups react with the reactive groups present in compound V, thereby ultimately curing the composition to obtain a solid polymer material.

[0107] In the case of cyanoacetate groups as reactive groups of compound V, the curing reaction is expected to form structural unit.

[0108] In the case of a 1,3-ketoester group as the reactive group of compound V, the curing reaction is expected to form a compound of the formula A structural unit of , wherein any further 1,3-ketoester groups present can add to the C═C double bonds formed, thus increasing the crosslinking density.

[0109] In the case of malonate groups as reactive groups of compound V, the curing reaction is expected to form A structural unit of , wherein further malonate groups which are optionally present can add to the C═C double bonds formed, thus increasing the crosslinking density.

[0110] In particular, during the curing process, an elastic material is formed which has a tensile strength of at least 1 MPa, preferably at least 2 MPa and an elongation at break of at least 50%, preferably at least 100%, more preferably at least 200%, and in particular at least 400%, the properties being determined in accordance with DIN EN 53504 at a tensile rate of 200 mm / min.

[0111] The aldehyde-functional polymers of the invention having end groups of the formula (I) enable particularly long processing times with rapid curing and particularly high tensile strength and tear propagation strength with high ductility, so that such polymer systems have particularly good processability and are particularly robust and long-lived.

[0112] The aldehyde-functional polymers according to the invention are particularly suitable as components of elastic adhesives, sealants or coatings which are substantially free of toxic ingredients and are not very sensitive to moisture and which have high resistance and robustness after curing. Example

[0113] Examples are described below which are intended to further illustrate the invention described. It is obvious that the invention is not limited to these described examples.

[0114] “Standard climatic conditions” (“NK”) mean a temperature of 23±1° C. and a relative air humidity of 50%±5%.

[0115] Unless otherwise stated, chemicals used were from Sigma-Aldrich Chemie GmbH.

[0116] Description of the measurement method:

[0117] The content of monomeric diisocyanate was determined by means of HPLC (detection by photodiode array; 0.04 M sodium acetate / acetonitrile as mobile phase) after prior derivatization by means of N-propyl-4-nitrobenzylamine.

[0118] The viscometer was set to Rheotec RC 30 cone and plate viscometer (cone diameter 10 mm, cone angle 1°, cone tip-plate distance 0.05 mm, shear rate 10 s -1 ) The viscosity was measured on a cone with a diameter of 50 mm. Viscosities less than 1 Pa·s were measured using a cone with a diameter of 50 mm.

[0119] Infrared spectra (FT-IR) were measured in the form of undiluted films on a Nicolet iS5 FT-IR instrument from Thermo Scientific equipped with a horizontal ATR measurement cell with a diamond crystal. The absorption bands are reported in wavenumbers (cm -1 )Report.

[0120] Preparation of polymers containing isocyanate groups:

[0121] Polymer NCO-1:

[0122] 780 g of ethylene oxide-terminated polyoxypropylene triol ( 5031BT, OH value 28.0 mgKOH / g, from Covestro) and 303 g isophorone diisocyanate ( IPDI, from Evonik) was converted by known methods at 80° C. into a reaction mixture having an NCO content of 9.1% by weight. Subsequently, the volatile constituents, in particular unconverted isophorone diisocyanate, were removed by distillation in a short-path evaporator (jacket temperature 160° C., pressure 0.1 to 0.005 mbar) to give a polymer having an NCO content of 1.84% by weight and a content of monomeric isophorone diisocyanate of 0.02% by weight.

[0123] Polymer NCO-2:

[0124] 894.5 g of ethylene oxide-terminated polyoxypropylene triol ( 5031BT, OH value 28.0 mgKOH / g, from Covestro) and 102.0 g isophorone diisocyanate ( IPDI (from Evonik) was converted by known methods at 80° C. in the presence of 0.01 g of dibutyltin dilaurate into a polymer having an NCO content of 1.83% by weight and a content of 1.4% by weight of monomeric isophorone diisocyanate.

[0125] Polymer NCO-3:

[0126] 590 g of polyoxypropylene glycol ( 4200, OH value 28mg KOH / g, from Covestro), 1180g ethylene oxide-terminated polyoxypropylene triol ( MD34-02, OH value 35 mg KOH / g, from Shell) and 230 g isophorone diisocyanate ( IPDI, from Evonik) was converted at 80° C. by known methods into a polymer having an NCO content of 2.1% by weight and a content of 1.3% by weight of monomeric isophorone diisocyanate.

[0127] Polymer NCO-4:

[0128] 818 g of polyoxypropylene glycol ( 4200, OH value 28.5 mg KOH / g, from Covestro) and 227 g isophorone diisocyanate ( IPDI, from Evonik) was converted by known methods at 80° C. into a reaction mixture having an NCO content of 6.6% by weight. Subsequently, the volatile constituents, in particular unconverted isophorone diisocyanate, were removed by distillation in a short-path evaporator (jacket temperature 160° C., pressure 0.1 to 0.005 mbar) to give a polymer having an NCO content of 1.91% by weight and a content of monomeric isophorone diisocyanate of 0.03% by weight.

[0129] Polymer NCO-5:

[0130] 600g polyoxypropylene glycol ( 1010L, OH value 112 mg KOH / g, from Dow) and 533.3 g isophorone diisocyanate ( IPDI, from Evonik) was converted by known methods at 80° C. to a reaction mixture having an NCO content of 15.6% by weight. Subsequently, the volatile constituents, in particular unconverted isophorone diisocyanate, were removed by distillation in a short-path evaporator (jacket temperature 160° C., pressure 0.1 to 0.005 mbar) to give a polymer having an NCO content of 5.18% by weight and a content of monomeric isophorone diisocyanate of 0.03% by weight.

[0131] Polymer NCO-6:

[0132] 150g polyoxypropylene glycol ( P400, OH value 263 mg KOH / g, from Dow) and 156.4 g isophorone diisocyanate ( IPDI, from Evonik) was converted at 80° C. by known methods into a reaction mixture having an NCO content of 9.65% by weight and a content of monomeric isophorone diisocyanate of >1% by weight.

[0133] Preparation of Aldehyde Functional Polymers:

[0134] Polymers A-1 to A-8:

[0135] For each compound, the amount (in parts by weight) of the corresponding polymer containing isocyanate groups specified in Table 1 was reacted with the amount (in parts by weight) of the corresponding hydroxy-functional aldehyde specified in Table 1 in the presence of 0.02% by weight of dibutyltin dilaurate at 110° C. with exclusion of moisture until isocyanate groups were no longer detectable by IR spectroscopy.

[0136]

[0137] Table 1: Preparation and properties of polymers A-1 to A-8

[0138] 1 4,4'-(2-Hydroxypropane-1,3-diyl)bis(oxy)bis(3-methoxybenzaldehyde), prepared from 2 mol of vanillin and 1 mol of epichlorohydrin

[0139] The average molecular weight Mn of polymer A-1 was also determined by gel permeation chromatography (GPC) with polystyrene (474-2520000 g / mol) as standard, tetrahydrofuran as mobile phase and a refractive index detector. The average molecular weight Mn was 6100 g / mol.

[0140] Polymer A-8 labeled "(Ref.)" is a comparative example having an average aldehyde content of 1.07 meq / g (ie, outside the claimed range). It is a glassy solid at room temperature and therefore was not used to prepare the curable composition.

[0141] Preparation of compounds having at least two reactive groups:

[0142] Compound V-1: (having cyanoacetate group)

[0143] To 50.0 g of trimethylolpropane-initiated poly(oxy-1,2-propylene)triol ( 4011T, OH value 550mg KOH / g, from Covestro) was added with 61.0g ethyl cyanoacetate and 0.1g tetra-n-butyl titanate ( TnBT, from Dorf Ketal), the mixture was converted at 140° C. under reduced pressure and distillation to remove ethanol. A clear, colorless liquid was obtained with a viscosity of 1.72 Pa·s at 20° C., a cyanoacetate functionality of 3, and a calculated cyanoacetate equivalent weight of 169 g / eq.

[0144] Compound V-2: (having acetoacetate group)

[0145] To 50.0 g of trimethylolpropane-initiated poly(oxy-1,2-propylene)triol ( 4011T, OH value 550mg KOH / g, from Covestro) was added with 67.0g ethyl acetoacetate and 0.1g tetra-n-butyl titanate ( TnBT, from Dorf Ketal), the mixture was converted at 140° C. under reduced pressure and distillation to remove ethanol. A clear, colorless liquid was obtained with a viscosity of 0.8 Pa·s at 20° C., an acetoacetate functionality of 3, and a calculated acetoacetate equivalent of 186 g / eq.

[0146] Compound V-3: (having a malonate group)

[0147] To 123.4 g of trimethylolpropane-initiated poly(oxy-1,2-propylene)triol ( 4011T, OH value 550mg KOH / g, from Covestro) was added with 192.2g diethyl malonate and 0.3g tetra-n-butyl titanate ( TnBT, from Dorf Ketal), the mixture was converted at 140° C. under reduced pressure and distillation to remove ethanol. A clear, colorless liquid was obtained with a viscosity of 7.3 Pa·s at 20° C., an estimated malonate functionality of about 3, and an estimated malonate equivalent weight of about 217 g / eq.

[0148] Preparation of curable composition:

[0149] Compositions Z-1 to Z-10

[0150] For each example, the mixture was stirred at room temperature using a centrifugal mixer (Speedmixer). TM DAC 150, Flacktek Inc.) The ingredients of the first component (K1) specified in Tables 2 and 3 were mixed in the specified amounts (parts by weight) and stored in a closed container.

[0151] The ingredients of the second component (K2) specified in Tables 2 and 3 were processed and stored likewise.

[0152] The "precipitated CaCO3" used is U1S2 (from Imerys), a precipitated and stearate-coated calcium carbonate.

[0153] The "carbon black" used is 570 (from Cabot).

[0154] The two components of each composition were then processed using a centrifugal mixer into a homogenous liquid, and the liquid was immediately tested as follows:

[0155] The gel time is determined by stirring a freshly mixed amount of about 3 g with a spatula at regular intervals under standard climatic conditions until this is no longer possible due to gelling of the mass.

[0156] The mechanical strength was determined by applying the mixed composition to a silicone-coated release paper to give a film with a thickness of 2 mm, allowing the film to cure for 7 days under standard climatic conditions, punching out several dumbbell-shaped specimens with a length of 75 mm, a beam length of 30 mm and a beam width of 4 mm from the film, and testing these specimens for tensile strength, elongation at break, 5% modulus of elasticity (at 0.5%-5% elongation) and 50% modulus of elasticity (at 0.5%-50% elongation) at a tensile rate of 200 mm / min according to DIN EN 53504. In addition, several specimens were punched out to determine the tear propagation strength and tested at a tensile rate of 500 mm / min according to DIN ISO 34-1, method B (angle specimens).

[0157] The Shore A hardness is determined in accordance with DIN 53505 on test specimens cured under standard climatic conditions for 7 days. These results are given with the addition "7d NK". For some compositions, the Shore A hardness is also determined after 1, 2 and 4 days of curing and is indicated accordingly. In order to determine the heat and water resistance, for several compositions, further Shore A test specimens are additionally stored in an air-circulating oven at 100° C. for 7 days or additionally at 70° C. and 100% relative humidity for 7 days after curing under standard climatic conditions and the Shore A hardness is determined as described after cooling to room temperature. These results are given with the addition "+7d 100° C." or "+7d 70 / 100".

[0158] In each case, a non-sticky, elastic material is formed during curing.

[0159] The results are reported in Tables 2 and 3.

[0160]

[0161]

[0162] Table 2: Composition and properties of Z-1 to Z-3

[0163] 1 2,2'-Bis(dimethylamino)diethyl ether

[0164] 2 2,2'-Dimorpholinodiethyl ether

[0165] It is evident from Table 2 that composition Z-1 comprising polymer A-1 and only 0.04 wt. % of compound of formula (II) has a longer processing time while simultaneously fast curing, and has higher tensile strength and tear propagation strength while simultaneously high ductility, compared to compositions Z-2 and Z-3 comprising polymers A-2 and A-3, which have high contents of compound of formula (II) of 2.8 wt. % and 2.6 wt. %, respectively.

[0166]

[0167]

[0168] Table 3: Composition and properties of Z-4 to Z-10

[0169] “nb” stands for “not determined”

[0170] 1 2,2'-Bis(dimethylamino)diethyl ether

[0171] 2 2,2'-Dimorpholinodiethyl ether

[0172] 3 1,8-Diazabicyclo[5.4.0]undec-7-ene (from BASF N700).

Claims

1. Nonionic aldehyde-functional polymers having terminal groups of formula (I) and it has an average content of aldehyde groups of 0.15 to 1.2 meq / g, preferably 0.2 to 0.75 meq / g, more preferably 0.2 to 0.7 meq / g, especially 0.3 to 0.6 meq / g, in R is a divalent organic group having 1 to 15 carbon atoms, and D is a divalent hydrocarbon group having 4 to 15 carbon atoms.

2. The aldehyde-functional polymer according to claim 1, characterized in that The average molecular weight Mn, measured by gel permeation chromatography (GPC) relative to polystyrene as standard, is from 1500 to 20 000 g / mol, preferably from 2500 to 15 000 g / mol and in particular from 3500 to 8000 g / mol.

3. The aldehyde-functional polymer according to claim 1 or 2, characterized in that The average aldehyde functionality is from 1.8 to 4, preferably from 2.0 to 3, especially from 2.2 to 3.

0.

4. The aldehyde-functional polymer according to any one of claims 1 to 3, characterized in that R is a linear or branched alkylene, cycloalkylene, arylalkylene or aryl group, which may also contain oxygen and / or nitrogen atoms.

5. The aldehyde-functional polymer according to any one of claims 1 to 4, characterized in that D is a divalent group of hexane-1,6-diamine, 2,2(4),4-trimethylhexane-1,6-diamine, 1-methyl-2,4(6)-diaminocyclohexane, isophoronediamine, 4,4'-diaminodicyclohexylmethane, diphenylmethane-4(2),4'-diamine or toluene-2,4(6)-diamine after removing two amino groups, preferably a group of hexane-1,6-diamine or isophoronediamine after removing two amino groups.

6. The aldehyde-functional polymer according to any one of claims 1 to 5, characterized in that They have a polymer backbone comprising poly(oxyalkylene) units and / or polyester units.

7. The aldehyde-functional polymer according to any one of claims 1 to 6, characterized in that It has a content of less than 1% by weight, based on the polymer, of the compound of formula (II) 8. The aldehyde-functional polymer according to any one of claims 1 to 7, characterized in that They have an acid group content of less than 0.1% by weight, based on the polymer.

9. The aldehyde-functional polymer according to any one of claims 1 to 8, characterized in that Its viscosity at 20°C is 1-500 Pa·s, preferably 2-200 Pa·s, especially 5-100 Pa·s, and the viscosity is measured by a cone diameter of 10 mm, a cone angle of 1°, a cone tip-plate distance of 0.05 mm, a shear rate of 10 s -1 The viscosity was measured by cone and plate viscometer.

10. The aldehyde-functional polymer according to any one of claims 1 to 9, characterized in that It is the reaction product of at least one hydroxyaldehyde of the formula HO-R-CHO and at least one polymer containing isocyanate groups.

11. The aldehyde-functional polymer of claim 10, characterized in that The polymer containing isocyanate groups is the reaction product of at least one monomeric diisocyanate of the formula OCN-D-NCO and at least one polymer polyol in an NCO / OH ratio in the range from 3 / 1 to 10 / 1, from which the monomeric diisocyanate is subsequently removed by a suitable separation process to a content of less than 0.5% by weight, based on the polymer containing isocyanate groups.

12. The aldehyde-functional polymer of claim 11, characterized in that The polymeric polyols are polymers having an OH value of 9 to 114 mg KOH / g, preferably 12 to 57 mg KOH / g, in particular 18 to 45 mg KOH / g, and the polymer backbone contains poly(oxyalkylene) units and / or polyester units.

13. Use of an aldehyde-functional polymer as claimed in any one of claims 1 to 12 for curing at least one compound V having at least two reactive groups which are reactive toward aldehydes.

14. The use according to claim 13, characterized in that The curing is carried out at ambient temperature, in particular at a temperature of -5 to 50°C, preferably 0 to 40°C.

15. The use according to any one of claims 13 and 14, characterized in that In the curing process, an elastic material is obtained, which has a tensile strength of at least 1 MPa, preferably at least 2 MPa, in particular at least 3 MPa, and an elongation at break of at least 50%, preferably at least 100%, more preferably at least 200%, in particular at least 400%, measured at a tensile rate of 200 mm / min according to DIN EN 53504.

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