Process for producing 2,2-dialkyl-3-acetyloxypropanal

Abstract

The present invention relates to a process for preparing an aldol ester of formula (I), which comprises reacting at least one carboxylic acid anhydride of formula (II) with at least one aldol of formula (III) by heating in the presence of a basic catalyst having a conjugate acid pKa of at least 8, and to the reaction product obtained therefrom. The process of the present invention provides a low-color, low-odor reaction product containing a high content of the aldol ester of formula (I) as a blocking agent for primary amines, which can be used without complicated purification steps, particularly without overhead distillation of the aldol ester. The blocked amine thus obtained has a long shelf life even when used with isocyanate-containing polymers and cures rapidly and easily upon contact with moisture to form mechanically high-performance, robust elastomers.

Description

Technical Field

[0001] The present invention relates to the production of aldol ester aldehydes and aldol ester aldimines, and in particular to moisture-curing polyurethane compositions containing these compounds for use as adhesives, sealants, or coatings.

Background Art

[0002] 2,2-Dialkyl-3-acyloxypropanal is a carboxylic acid ester of aldol from the crossed aldol reaction of a secondary aliphatic aldehyde and formaldehyde. They are versatile starting materials, for example, for the production of fragrances, dyes, and polymers. Of particular commercial interest is their use as blocking agents for primary polyamines. The resulting aldol ester aldimines are particularly suitable as potential curing agents for polymers containing isocyanate groups. As described, for example, in European Patent No. 1 527 115 or International Publication No. 2016 / 005457 pamphlet, polyurethane compositions having good storage stability, curing rapidly upon contact with moisture, and forming stable elastomers of high mechanical quality with good processing reliability can be obtained from them.

[0003] The preparation method of 2,2-dialkyl-3-acetyloxypropanal has been described in the literature many times. In the known preparation methods, the aldol 2,2-dialkyl-3-hydroxypropanal is used as it is, or generated in situ from the starting aldehyde, and esterified with a carboxylic acid, or, less frequently, with their acid anhydrides or enol esters, to form the aldol ester 2,2-dialkyl-3-acetyloxypropanal. For example, as described in U.S. Patent No. 3,251,876, U.S. Patent No. 3,374,267, or U.S. Patent No. 3,720,705, the esterification reaction and the accompanying aldol formation reaction are typically carried out in the presence of an acid catalyst, such as sulfuric acid or p-toluenesulfonic acid, and then the aldol ester is isolated and purified, especially by distillation.

[0004] The disadvantage of the above preparation method is actually that the yield of the reaction product is relatively low. The reaction product thus obtained is typically extremely black in color and has a pungent odor of strongly malodorous by-products, and therefore, it needs to be purified in order to be further usable. Furthermore, empirically speaking, in the production process under acid catalysis, especially for short-chain aldol esters, there is a risk of exotherm in the process, and thus it becomes impossible to operate safely in large-scale production facilities. This applies not only to the reaction itself, even when operating without a solvent or an entraining agent that suppresses the reaction temperature, but also to the purification of the reaction product after the reaction, especially by distillation at the top of the column. For example, at a temperature in the region of 150 °C, a strong thermal decomposition reaction has already occurred, and even if the acid catalyst is neutralized subsequently, it is impossible to sufficiently suppress the reaction. In addition, under such strongly acidic conditions, it is also necessary to carry out production with corrosion-resistant equipment. The catalyst-free preparation method under neutral conditions as described in U.S. Patent No. 4,017,537 and the preparation method using pyridine as a catalyst as described in German Patent No. 19 506728 do not pose a risk of exotherm in the process and also have no corrosion problems, but they are still not satisfactory because of the extremely long reaction time and the rather low yield obtained. Summary of the Invention Problems to be Solved by the Invention

[0005] Accordingly, an object of the present invention is to provide a method for preparing 2,2-dialkyl-3-acetyloxypropanal that gives a high reaction product yield and can be carried out with a good space-time yield without the risk of exotherm in the process. Means for Solving the Problems

[0006] This object is achieved by the method according to claim 1. In this method, a carboxylic anhydride is reacted with an aldol while heating in the presence of a basic catalyst having a pKa of at least 8 for the conjugate acid. To date, there is no description anywhere of this type of method using a basic catalyst. Surprisingly, it has been found that the method of the present invention enables a rapid reaction in high yield without the risk of exotherm in the process and without the need for a solvent or a cosolvent. The reaction product thus obtained is surprisingly lightly colored and has a low odor, so that it does not require troublesome purification, in particular it is not necessary to use overhead distillation, and in particular it can be used as a blocking agent for primary amines. Since there is no corrosive action on metals, the method of the present invention can be carried out in an inexpensive standard reactor made of stainless steel. What is particularly surprising in the method of the present invention is that the reaction product is stable even when heated to a temperature well above 200 °C, even in the case of short-chain aldol esters, in particular 2,2-dialkyl-3-acetyloxypropanal, whereas heating the corresponding reaction product from an acid-catalyzed process to a temperature above 150 °C results in a strong exotherm, suggesting a fairly high risk of exotherm in the process.

[0007] The method of the present invention provides reaction products that are lightly colored, have a low odor, and have a high content of 2,2-dialkyl-3-acyl-oxypropanal, which do not require the use of troublesome purification steps, in particular it is not necessary to use overhead distillation of 2,2-dialkyl-3-acyl-oxypropanal, and can be used as a blocking agent for primary amines. The blocked amine / potential curing agent thus obtained has a low odor and, surprisingly, has storage stability even when combined with a polymer containing isocyanate groups, and when brought into contact with moisture, cures rapidly and with good processing reliability to form a stable elastomer of high mechanical quality.

[0008] A further aspect of the invention is the subject matter of the further independent claims. Particularly preferred embodiments of the invention are the subject matter of the dependent claims.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Embodiments for Carrying Out the Invention

[0010] The present invention is a method for preparing an aldol ester of the following formula (I),

Chemical formula

Chemical formula

Chemical formula

[0011] An "aliphatic" aldehyde group or isocyanate group refers to one directly bonded to an aliphatic or alicyclic carbon atom.

[0012] An "aromatic" aldehyde group or isocyanate group refers to one directly bonded to an aromatic carbon atom.

[0013] A "primary amino group" refers to an amino group bonded to a single organic group and carrying two hydrogen atoms; a "secondary amino group" refers to an amino group bonded to two organic groups (which together may form part of a ring) and carrying one hydrogen atom; and a "tertiary amino group" refers to an amino group bonded to three organic groups (two or three of which may be part of one or more rings) and carrying no hydrogen atoms.

[0014] Substances named starting with "poly", such as polyamines, polyols or polyisocyanates, formally refer to substances containing two or more of the functional groups included in their names per molecule.

[0015] "Molecular weight" refers to the molar mass of a molecule or molecular residue (unit: g / mol). "Average molecular weight" refers to the number-average molecular weight (M n ) of a polydisperse mixture of oligomeric or polymeric molecules or molecular residues. It is determined by gel permeation chromatography (GPC) relative to polystyrene as a standard.

[0016] Values of weight percent (wt%) refer to the mass ratio of the components of a composition, unless otherwise specified, based on the entire composition. The terms "mass" and "weight" are used synonymously in this specification.

[0017] "NCO content" refers to the content of isocyanate groups (unit: wt%).

[0018] A substance or composition is called "storage stable" or "storable" if it can be stored at room temperature for a long period, typically at least from 3 months to 6 months or more, in a suitable container, without any change that would interfere with its use or performance in that use.

[0019] "Room temperature" refers to a temperature of 23 °C.

[0020] All industry standards and benchmarks described in this specification relate to the version in force on the date of the first filing.

[0021] R 1 is methyl or ethyl, particularly methyl, and R 2 is preferably methyl, ethyl, n-propyl, or n-butyl.

[0022] R 1 and R 2 are each preferably methyl.

[0023] R 3 is preferably a hydrocarbyl group having 1 to 11 carbon atoms, optionally chlorinated.

[0024] R 3 is more preferably an alkyl group having 1 to 7 carbon atoms or phenyl.

[0025] R 3 is most preferably methyl.

[0026] Preferred groups R 1 、R 2 、and R 3 are particularly readily obtainable and give the aldol esters of formula (I), but they are particularly suitable as blocking agents for primary amines.

[0027] Group R 3is small, especially when it is methyl, the method of the present invention is particularly advantageous because, in the known acid catalyst methods of the prior art, strong coloring, strong odor, and highly dangerous, thermally unstable reaction products in the process are generated. A small group R 3 Blocked amines (blocked amines) based on aldol esters of formula (I) having, especially methyl, are particularly suitable for moisture-curing polyurethane compositions which are required to have, for example for coating purposes, particularly low viscosity and / or particularly high hardness.

[0028] The basic catalyst preferably has a pKa of at least 9, especially at least 10, of the conjugate acid. This results in a particularly rapid reaction.

[0029] The basic catalyst is preferably a tertiary amine or an amidine.

[0030] More preferably, the basic catalyst is selected from the group consisting of trimethylamine, dimethylethylamine, methyldiethylamine, triethylamine, diisopropylethylamine, N-methylpyrrolidine, N-methylpiperidine, 1,5-diazabicyclo[4.3.0]non-5-ene (DBN), and 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU). These compounds are readily available and exhibit good catalytic activity in the method of the present invention.

[0031] Most preferably, it is triethylamine. This enables a particularly rapid reaction, is inexpensive, and is volatile, so it can be easily removed from the reaction mixture by distillation. Furthermore, it also has excellent compatibility as a catalyst for promoting the preparation of the aldol of formula (III).

[0032] The basic catalyst is preferably used in an amount in the range of 0.01% to 10% by weight, especially 0.05% to 5% by weight, based on the total reaction mixture.

[0033] The most preferred catalyst, triethylamine, is used in an amount preferably in the range of 0.1% to 10% by weight, particularly 0.5% to 5% by weight, based on the total reaction mixture.

[0034] The method is preferably carried out at a temperature in the range of 80 to 150 °C, particularly 100 to 130 °C.

[0035] The carboxylic acid anhydride of formula (II) is preferably used in a stoichiometrically excess amount with respect to the aldol of formula (III).

[0036] It is preferred to initially charge the aldol of formula (III) and add the carboxylic acid anhydride of formula (II) in the presence of a basic catalyst.

[0037] It is preferred to remove most or all of the carboxylic acid released from the carboxylic acid anhydride, unreacted carboxylic acid anhydride, basic catalyst, and any volatile by-products and solvents present, during or after the reaction, particularly by vacuum distillation, from the reaction mixture.

[0038] Optionally, a solvent or a co-entrainer may be used, such as, in particular, cyclohexane or toluene, or a hydrocarbon mixture, for example petroleum spirit or hydrogenated naphthalite, particularly those having a boiling range of 75 to 95 °C or 80 to 100 °C.

[0039] The method is preferably carried out without using an organic solvent or a co-entrainer.

[0040] The carboxylic acid anhydride of formula (II) is preferably selected from the group consisting of acetic anhydride, propionic anhydride, butyric anhydride, isobutyric anhydride, hexanoic anhydride, 2-ethylhexanoic anhydride, lauric anhydride, benzoic anhydride, chloroacetic anhydride, dichloroacetic anhydride, and trichloroacetic anhydride.

[0041] Among these, acetic anhydride, propionic anhydride, hexanoic anhydride, 2-ethylhexanoic anhydride, or benzoic anhydride is preferable.

[0042] Most preferably, it is acetic anhydride.

[0043] The aldol of formula (III) is, in some cases, used in the form of an oligomer, particularly in the form of a dimer of formula (IIIa).

Chemical formula

[0044] The aldol of formula (III) or its oligomer is preferably obtained by reacting with formaldehyde, in some cases formaldehyde in the form of paraformaldehyde or trioxane, and an aldehyde of formula (IV)

Chemical formula

[0045] Formaldehyde is preferably used in the form of formalin or paraformaldehyde, more preferably in the form of paraformaldehyde.

[0046] The aldehyde of formula (IV) is preferably isobutyraldehyde, 2-methylbutyraldehyde, 2-ethylbutyraldehyde, 2-methylvaleraldehyde, or 2-ethylcaproaldehyde.

[0047] Particularly preferably, it is isobutyraldehyde.

[0048] The aldol of formula (III) is preferably obtained by reacting with formaldehyde, in some cases formaldehyde in the form of paraformaldehyde or trioxane, and at least one aldehyde of formula (IV)

Chemical formula

[0049] This reaction mixture containing the aldol of formula (III) does not contain, in particular, strong acids, in particular halogen-containing acids such as boron trichloride, boron tribromide, or hydrochloric acid. This means that the basic catalyst does not form any salts that would interfere with its activity.

[0050] The reaction of formaldehyde with at least one aldehyde of formula (IV) is a cross-aldol reaction. It is preferably carried out in the presence of a basic catalyst having a pKa of at least 8, preferably at least 9, in particular at least 10 for the conjugate acid. It is preferably the same basic catalyst as that used in the esterification reaction of the carboxylic acid anhydride of formula (II) with the aldol of formula (III), i.e., the basic catalyst used to prepare the aldol ester of formula (I) in the process of the present invention. Triethylamine is particularly preferred as the basic catalyst for both reactions.

[0051] The amount of the basic catalyst used for the aldol reaction is preferably in the range of 0.1% to 20% by weight, in particular 0.5% to 15% by weight, based on the total reaction mixture for the aldol reaction.

[0052] The aldol reaction is preferably carried out at a temperature within the range of 60 to 90 °C.

[0053] It is preferred to use the aldehyde of formula (IV) in a stoichiometric excess with respect to formaldehyde.

[0054] Formaldehyde is preferably used in the form of formalin or paraformaldehyde, in particular in the form of paraformaldehyde.

[0055] In the aldol reaction, a solvent may be present. It is preferred to carry out the aldol reaction without an organic solvent.

[0056] Subsequent to the aldol reaction, it is preferred to remove volatile substances, in particular unreacted aldehyde of formula (IV), the solvent, and optionally part of the basic catalyst, in particular by distillation under reduced pressure.

[0057] It is particularly preferred to carry out the process of the invention in the following two-step process: (i) In the first step (aldol reaction), a basic catalyst and formaldehyde (in particular in the form of paraformaldehyde) are initially charged, and then at least one aldehyde of formula (IV) is added in a stoichiometric excess relative to the formaldehyde at a temperature in the range of 60 to 90 °C to form the aldol of formula (III), and then volatile substances, in particular the excess aldehyde of formula (IV), and optionally part of the basic catalyst are removed from the reaction mixture, (ii) In the second step (esterification), the reaction mixture thus obtained is reacted with the carboxylic anhydride of formula (II) at a temperature in the range of 100 to 130 °C, where volatile substances, in particular the carboxylic acid released from the carboxylic anhydride, unreacted carboxylic anhydride, and optionally the basic catalyst are removed from the reaction mixture during and / or after the reaction, in particular by distillation under reduced pressure.

[0058] The invention further provides a reaction product obtainable by the process of the invention, in particular a reaction product obtainable from the preferred two-step process, which is characterized in that it contains: 60% to 95% by weight, in particular 65% to 90% by weight, more preferably 70% to 85% by weight of the aldol ester of formula (I), and 5% to 40% by weight, preferably 10% to 35% by weight, in particular 15% to 30% by weight of other esters, aldehydes, and / or acetals not corresponding to formula (I).

[0059] The aldol esters of formula (I) present in the reaction product are preferably selected from the group consisting of: 2,2-dimethyl-3-acetoxypropanal, 2,2-dimethyl-3-propionyloxypropanal, 2,2-dimethyl-3-hexanoyloxypropanal, 2,2-dimethyl-3-(2-ethylhexanoyloxy)propanal, and 2,2-dimethyl-3-benzoyloxypropanal. Particularly preferred is 2,2-dimethyl-3-acetoxypropanal.

[0060] In addition to the aldol esters of formula (I), the reaction product of the present invention preferably contains a triester of formula (V) and / or an acetal of formula (VI): [Chemical formula] [R in formulas (V) and (VI) 1 , R 2 , and R 3 are as defined above].

[0061] The reaction product of the present invention preferably contains 0.1% to 20% by weight, particularly 0.5% to 15% by weight, more preferably 1% to 10% by weight, of the triester of formula (V).

[0062] The reaction product of the present invention preferably contains 1% to 20% by weight, particularly 2% to 15% by weight, more preferably 3% to 10% by weight, of the acetal of formula (VI).

[0063] The reaction product of the present invention has the advantage of containing no halides, so there is no need to remove them using a cumbersome finishing process.

[0064] The reaction product of the present invention is transparent, lightly colored, and has a low odor. Therefore, it can be used without further purification. The reaction product is also extremely thermally stable and does not show any significant exotherm even when heated to 200 °C. This enables high process safety in its preparation and processing.

[0065] The reaction product of the present invention can also be further purified, especially before use for the isolation of the aldol ester of formula (I) by overhead distillation. Even in that case, the high thermal stability of the reaction product works particularly advantageously.

[0066] The reaction product of the present invention is preferably used without further purification.

[0067] The reaction product of the present invention is suitable for numerous applications, especially for the production of fragrances, dyes, or polymers. The reaction product of the present invention is particularly suitable as a blocking agent for primary amines.

[0068] It is preferred to use the reaction product of the present invention for the production of blocked amines (blocked amines). For this purpose, the reaction product is reacted with at least one primary amine. In this reaction, the primary amino group undergoes a condensation reaction with the aldehyde group to release water and form an aldimine group, which represents a blocked, hydrolytically activatable form of the primary amino group.

[0069] The blocked amine (blocked amine) obtained by the reaction of the reaction product of the present invention with a primary amine can be advantageously used as a latent curing agent in moisture-curing polyurethane compositions.

[0070] Regarding the reaction using the reaction product of the present invention, a primary amine that is bifunctional with respect to isocyanate groups, that is, in addition to a primary amino group, at least 1 additional primary amino group, and / or at least 1 secondary amino group, and / or a primary amine having at least 1 hydroxyl group is preferred. The blocked amine (blocked amine) thus obtained is particularly suitable as a latent curing agent for polyurethane compositions. They have particularly advantageous properties in relation to storage stability, processability, curability, and mechanical properties.

[0071] Accordingly, the present invention further provides a blocked amine (blocked amine) obtained by reacting the reaction product of the present invention with at least 1 amine having a primary amino group and in addition at least 1 reactive group selected from a primary amino group, a secondary amino group, and a hydroxyl group. It is preferred that the amine has only 1 secondary amino group or only 1 hydroxyl group. It is particularly preferred that the amine does not contain a secondary amino group.

[0072] The blocked amine (blocked amine) thus obtained includes, in addition to the aldimine from the reaction of the aldol ester of formula (I), by-products from the method of the present invention present in the reaction product used, particularly the triester of formula (V) described above, and / or the acetal of formula (VI), and / or the reaction product of these with the amine.

[0073] Suitable amines for blocking include, in particular, the following: - Primary aliphatic diamines, for example, in particular, ethane-1,2-diamine, propane-1,2-diamine, propane-1,3-diamine, butane-1,4-diamine, butane-1,3-diamine, 2-methylpropane-1,2-diamine, pentane-1,3-diamine, pentane-1,5-diamine, 2,2-dimethylpropane-1,3-diamine, hexane-1,6-diamine, 1,5-diamino-2-methylpentane, heptane-1,7-diamine, octane-1,8-diamine, 2,5-dimethylhexane-1,6-diamine, nonane-1,9-diamine, 2,2(4),4-trimethylhexane-1,6-diamine, decane-1,10-diamine, undecane-1,11-diamine, 2-butyl-2-ethylpentane-1,5-diamine, dodecane-1,12-diamine, cyclohexane-1,2-diamine, cyclohexane-1,3-diamine, cyclohexane-1,4-diamine, 1-amino-3-aminomethyl-3,5,5-trimethylcyclohexane, 4(2)-methylcyclohexane-1,3-diamine, 1,3-bis(aminomethyl)cyclohexane, 1,4-bis(aminomethyl)cyclohexane, bis(4-aminocyclohexyl)methane, bis(4-amino-3-methylcyclohexyl)methane, bis(4-amino-3-ethylcyclohexyl)methane, bis(4-amino-3,5-dimethylcyclohexyl)methane, bis(4-amino-3-ethyl-5-methylcyclohexyl)methane, 2,5(2,6)-bis(aminomethyl)bicyclo[2.2.1]heptane, 3(4),8(9)-bis(aminomethyl)tricyclo[5.2.1.0 2,6 decane, 1,3-bis(aminomethyl)benzene, 1,4-bis(aminomethyl)benzene, 3-oxapentane-1,5-diamine, 3,6-dioxaoctane-1,8-diamine, 4,7-dioxadecane-1,10-diamine, 4,7-dioxadecane-2,9-diamine, 4,9-dioxadodecane-1,12-diamine, 5,8-dioxadodecane-3,10-diamine, 4,7,10-trioxatridecane-1,13-diamine, average molecular weight M within the range of 170 to 4000 g / mol nα,ω - polyoxypropylene diamine having the following, in particular, D - 230, D - 400, XTJ - 582, D - 2000, XTJ - 578, or D - 4000 (all manufactured by Huntsman) of Jeffamine® products, α,ω - polyoxypropylene / polyoxyethylene diamine, in particular, ED - 600, ED - 900, ED - 2003, or HK - 511 (all manufactured by Huntsman) of Jeffamine® products, α,ω - polyoxypropylene / polyoxy - 1,4 - butylene diamine, in particular, THF - 100, THF - 140, THF - 230, XTJ - 533, or XTJ - 536 (all manufactured by Huntsman) of Jeffamine® products, α,ω - polyoxypropylene / polyoxy - 1,2 - butylene diamine, in particular, XTJ - 568, or XTJ - 569 (both manufactured by Huntsman) of Jeffamine® products, or α,ω - polyoxy - 1,2 - butylene diamine, in particular, Jeffamine® XTJ - 523 (manufactured by Huntsman), - Primary aliphatic triamines, for example, in particular, 1,3,6 - triaminohexane, 1,4,8 - triaminooctane, 4 - aminomethyloctane - 1,8 - diamine, 5 - aminomethyloctane - 1,8 - diamine, 1,6,11 - triaminoundecane, 1,3,5 - triaminocyclohexane, 1,3,5 - tris(aminomethyl)cyclohexane, 1,3,5 - tris(aminomethyl)benzene, with an average molecular weight M in the range of 330 to 6000 g / mol n Tris(ω - polyoxypropylene amine) starting from trimethylolpropane or glycerol having the following, in particular, T - 403, T - 3000, or T - 5000 (all manufactured by Huntsman) of Jeffamine® products, or tris(ω - polyoxypropylene / polyoxy - 1,2 - butylene amine) starting from trimethylolpropane, in particular, Jeffamine® XTJ - 566 (manufactured by Huntsman), or - Primary aromatic diamines, for example, in particular, 1,3-phenylenediamine, 1,4-phenylenediamine, 4(2)-methyl-1,3-phenylenediamine (TDA), 3,5-diethyl-2,4(6)-tolylenediamine (DETDA), or 4,4'-diaminodiphenylmethane (MDA), or, - Aliphatic diamines having a primary amino group and a secondary amino group, for example, in particular, N-methylethane-1,2-diamine, N-ethylethane-1,2-diamine, N-butylethane-1,2-diamine, N-hexyethane-1,2-diamine, N-(2-ethylhexyl)ethane-1,2-diamine, N-cyclohexylethane-1,2-diamine, N-benzylethane-1,2-diamine, 4-aminomethylpiperidine, 3-(4-aminobutyl)piperidine, N-(2-aminoethyl)piperazine, N-(2-aminopropyl)piperazine, N-benzylpropane-1,2-diamine, N-benzylpropane-1,3-diamine, N-methylpropane-1,3-diamine, N-ethylpropane-1,3-diamine, N-butylpropane-1,3-diamine, N-hexylpropane-1,3-diamine, N-(2-ethylhexyl)propane-1,3-diamine, N-dodecylpropane-1,3-diamine, N-cyclohexylpropane-1,3-diamine, 3-methylamino-1-pentylamine, 3-ethylamino-1-pentylamine, 3-butylamino-1-pentylamine, 3-hexylamino-1-pentylamine, 3-(2-ethylhexyl)amino-1-pentylamine, 3-dodecylamino-1-pentylamine, 3-cyclohexylamino-1-pentylamine, aliphatic diamines, for example, N-cocoalkylpropane-1,3-diamine, N-oleylpropane-1,3-diamine, N-soyaalkylpropane-1,3-diamine, N-tallowalkylpropane-1,3-diamine, or N-(C 16~22(Alkyl)propane-1,3-diamine, for example, those available from Akzo Nobel under the trade name Duomeen®, or aliphatic primary diamines, products from Michael-type addition reactions in which acrylonitrile, maleic or fumaric acid diesters, citraconic acid diesters, (meth)acrylic acid esters, (meth)acrylamides, or itaconic acid diesters are reacted with them in a molar ratio of (1:1), or - aliphatic polyamines having two primary and secondary amino groups, for example, in particular, bis(hexamethylene)triamine (BHMT), diethylenetriamine (DETA), dipropylenetriamine (DPTA), N-(2-aminoethyl)propane-1,3-diamine (N3 amine), N3-(3-aminopentyl)pentane-1,3-diamine, or N5-(3-amino-1-ethylpropyl)-2-methylpentane-1,5-diamine, or - hydroxylamines, for example, in particular, 2-aminoethanol, 2-amino-1-propanol, 1-amino-2-propanol, 3-amino-1-propanol, 4-amino-1-butanol, 4-amino-2-butanol, 2-amino-2-methylpropanol, 5-amino-1-pentanol, 6-amino-1-hexanol, 7-amino-1-heptanol, 8-amino-1-octanol, 10-amino-1-decanol, 12-amino-1-dodecanol or their higher homologues, 4-(2-aminoethyl)-2-hydroxyethylbenzene, 3-aminomethyl-3,5,5-trimethylcyclohexanol, derivatives bearing primary amino groups of glycols, for example, diethylene glycol, dipropylene glycol, dibutylene glycol, or their higher oligomers or polymers, in particular, 2-(2-aminoethoxy)ethanol, 2-(2-(2-aminoethoxy)ethoxy)ethanol, or α-(2-hydroxymethylethyl)-ω-(2-aminomethylethoxy)-poly(oxy(methylethane-1,2-diyl)), 3-(2-hydroxyethoxy)propylamine, 3-(2-(2-hydroxyethoxy)ethoxy)propylamine, or 3-(6-hydroxyhexyloxy)propylamine.

[0074] The amine is, in particular, selected from the group consisting of: hexane-1,6-diamine, 1-amino-3-aminomethyl-3,5,5-trimethylcyclohexane, 4(2)-methylcyclohexane-1,3-diamine, 1,3-bis(aminomethyl)cyclohexane, 1,4-bis(aminomethyl)cyclohexane, 1,3-bis(aminomethyl)benzene, cyclohexane-1,2-diamine, cyclohexane-1,3-diamine, cyclohexane-1,4-diamine, bis(4-aminocyclohexyl)methane, 2,5(2,6)-bis(aminomethyl)bicyclo[2.2.1]heptane, 3(4),8(9)-bis(aminomethyl)tricyclo[5.2.1.0 2,6 decane, an α,ω-polyoxypropylene diamine having an average molecular weight M in the range of 170 to 500 g / mol, in particular D-230 or D-400 (manufactured by Huntsman) of the Jeffamine® product, a trimethylolpropane or glycerol starting tris(ω-polyoxypropyleneamine) having an average molecular weight M in the range of 330 to 500 g / mol, in particular T-403 of Jeffamine® (manufactured by Huntsman), 1,4-phenylenediamine, 3,5-diethyl-2,4(6)-toluenediamine, 2-(2-aminoethoxy)ethanol, 2-(2-(2-aminoethoxy)ethoxy)ethanol, and 3-aminomethyl-3,5,5-trimethylcyclohexanol. n having an α,ω-polyoxypropylene diamine having an average molecular weight M in the range of 170 to 500 g / mol, in particular D-230 or D-400 (manufactured by Huntsman) of the Jeffamine® product, a trimethylolpropane or glycerol starting tris(ω-polyoxypropyleneamine) having an average molecular weight M in the range of 330 to 500 g / mol, in particular T-403 of Jeffamine® (manufactured by Huntsman), 1,4-phenylenediamine, 3,5-diethyl-2,4(6)-toluenediamine, 2-(2-aminoethoxy)ethanol, 2-(2-(2-aminoethoxy)ethoxy)ethanol, and 3-aminomethyl-3,5,5-trimethylcyclohexanol. n starting from trimethylolpropane or glycerol having a tris(ω-polyoxypropyleneamine), in particular T-403 of Jeffamine® (manufactured by Huntsman), 1,4-phenylenediamine, 3,5-diethyl-2,4(6)-toluenediamine, 2-(2-aminoethoxy)ethanol, 2-(2-(2-aminoethoxy)ethoxy)ethanol, and 3-aminomethyl-3,5,5-trimethylcyclohexanol.

[0075] Among these, the preferred ones are: hexane-1,6-diamine, 1-amino-3-aminomethyl-3,5,5-trimethylcyclohexane, an α,ω-polyoxypropylene diamine having an average molecular weight M in the range of 170 to 300 g / mol, a tris(ω-polyoxypropyleneamine) starting from trimethylolpropane having an average molecular weight M in the range of 330 to 500 g / mol, or 2-(2-aminoethoxy)ethanol. n having an α,ω-polyoxypropylene diamine having an average molecular weight M in the range of 170 to 300 g / mol, a tris(ω-polyoxypropyleneamine) starting from trimethylolpropane having an average molecular weight M in the range of 330 to 500 g / mol, or 2-(2-aminoethoxy)ethanol. n starting from trimethylolpropane having a tris(ω-polyoxypropyleneamine), or 2-(2-aminoethoxy)ethanol.

[0076] These preferred amines can be easily obtained. In blocked form, they give moisture-curing polyurethane compositions having good storage stability, good processability, rapid curability, and high strength combined with high extensibility.

[0077] When the blocked amine (blocked amine) has a hydroxyl group or a secondary amino group, that group reacts with the isocyanate groups present during storage.

[0078] The blocked amine (blocked amine) of the present invention is preferably prepared by the following steps: - Incorporating the reaction product of the present invention, optionally with the addition of a solvent, into the reaction mixture together with an amine, such that the aldehyde group is present in stoichiometric amount or in stoichiometric excess with respect to the primary amino group. - Removing the condensed water formed in the reaction and optionally any solvent used from the reaction mixture, by means of a suitable method, during or after the incorporation step.

[0079] The condensed water and optionally any solvent used are preferably removed from the heated reaction mixture by applying reduced pressure.

[0080] It is preferred not to use a solvent.

[0081] The reaction is preferably carried out at a temperature in the range of 20°C to 120°C, particularly 40°C to 100°C.

[0082] In the reaction, optionally a catalyst, particularly an acid catalyst, is used.

[0083] The blocked amine (blocked amine) of the present invention particularly contains at least one aldimine of formula (VII): [wherein, [In the formula, m is 0 or 1, n is 1 or 2 or 3, and (m + n) is 2 or 3, A is an organic group having (m + n) valences and 2 to 25 carbon atoms, R 1 、R 2 、and R 3 are as defined above.

[0084] It is preferred that m is 0 and n is 2 or 3. Such an aldimine of formula (VII) is a di- or tri-aldimine.

[0085] More preferably, m is 1 and n is 1. Such an aldimine of formula (VII) is a hydroxyaldimine.

[0086] A is preferably an alkylene group having 5 to 15 carbon atoms, optionally having a cyclic component, or a divalent or trivalent polyoxyalkylene group.

[0087] Particularly preferred is when A is a group selected from the group consisting of: 1,6 - hexylene, (1,5,5 - trimethylcyclohexan - 1 - yl)methane - 1,3, α,ω - polyoxypropylene having an average molecular weight M in the range of 170 to 300 g / mol, n tris(ω - polyoxypropylene) starting from trimethylolpropane having an average molecular weight M in the range of 330 to 500 g / mol, 1,4 - phenylene, 3,5 - diethyl - 2,4(6) - tolylene, and 3 - oxa - 1,5 - pentylene. n

[0088] Particularly preferred is when the aldimine of formula (VII) is selected from the group consisting of: N,N’ - bis(2,2 - dimethyl - 3 - acetoxypropylidene)hexylene - 1,6 - diamine, N,N’ - bis(2,2 - dimethyl - 3 - acetoxypropylidene) - 3 - aminomethyl - 3,5,5 - trimethylcyclohexylamine, an average molecular weight M in the range of 450 to 880 g / mol nN,N'-bis(2,2-dimethyl-3-acetoxypropylidene)polyoxypropylene diamine having an average molecular weight M in the range of 730 to 880 g / mol n N,N',N''-tris(2,2-dimethyl-3-acetoxypropylidene)polyoxypropylene triamine, N,N'-bis(2,2-dimethyl-3-acetoxypropylidene)phenylenediamine-1,4, N,N'-bis(2,2-dimethyl-3-acetoxypropylidene)-3,5-diethyl-tolylene-2,4(6)-diamine, and N-(2,2-dimethyl-3-acetoxypropylidene)-2-(2-aminoethoxy)ethan-1-ol.

[0089] Their preferred blocked amines provide a moisture-curing polyurethane composition having good storage stability, good processability, especially rapid curability, and especially high strength combined with high elongation. In the case of N-(2,2-dimethyl-3-acetoxypropylidene)-2-(2-aminoethoxy)ethan-1-ol, the hydroxyl group reacts with the isocyanate groups present during storage.

[0090] The present invention further provides a moisture-curing polyurethane composition comprising the following: - at least one polyisocyanate and / or a polymer containing isocyanate groups, and - at least one blocked amine from the reaction of the reaction product of the present invention as described above.

[0091] The moisture-curing polyurethane composition preferably contains at least one blocked amine containing an aldimine of formula (VII).

[0092] Suitable polyisocyanates are the following: - Commercially available aromatic, aliphatic, or cycloaliphatic diisocyanates, such as, in particular, diphenylmethane 4,4'-diisocyanate (optionally containing diphenylmethane 2,4'- and / or 2,2'-diisocyanate fractions) (MDI), diphenylmethane 2,4'-diisocyanate (2,4'-MDI), tolylene 2,4-diisocyanate, or a mixture thereof with tolylene 2,6-diisocyanate (TDI), phenylene 1,4-diisocyanate (PDI), naphthalene 1,5-diisocyanate (NDI), hexane 1,6-diisocyanate (HDI), 2,2(4),4-tetramethylhexamethylene 1,6-diisocyanate (TMDI), cyclohexane 1,3- or 1,4-diisocyanate, 1-isocyanato-3,3,5-trimethyl-5-isocyanatomethylcyclohexane (isophorone diisocyanate, i.e., IPDI), perhydrodiphenylmethane 2,4'- or 4,4'-diisocyanate (HMDI), 1,3- or 1,4-bis(isocyanatomethyl)cyclohexane, m- or p-xylylene diisocyanate (XDI), or mixtures thereof, - Higher functionality derivatives of such diisocyanates, in particular, liquefied diphenylmethane 4,4'-diisocyanate by carbodiimidization, uretonimine formation, or adduct formation with a polyol, - Mixtures of MDI that are liquid at room temperature (including homologues of MDI) (polymeric MDI, i.e., PMDI), - Oligomers of diisocyanates, for example, in particular, HDI biuret such as Desmodur® N100 or N3200 (manufactured by Covestro), Tolonate® HDB or HDB-LV (manufactured by Vencorex), or Duranate® 24A-100 (manufactured by Asahi Kasei); HDI isocyanurate such as Desmodur® N3300, N3600 or N3790BA (all manufactured by Covestro), Tolonate® HDT, HDT-LV or HDT-LV2 (manufactured by Vencorex), Duranate® TPA-100 or THA-100 (manufactured by Asahi Kasei), or Coronate® HX (manufactured by Tosoh); HDI uretdione such as Desmodur® N3400 (manufactured by Covestro); HDI iminooxadiazinedione such as Desmodur® XP2410 (manufactured by Covestro); HDI allophanate such as Desmodur® VP LS2102 (manufactured by Covestro); IPDI isocyanurate such as the solution type Desmodur® Z4470 (manufactured by Covestro) or the solid type Vestanat® T1890 / 100 (manufactured by Evonik Industries); TDI oligomer such as Desmodur® IL (manufactured by Covestro); or a mixed isocyanurate based on TDI / HDI such as Desmodur® HL (manufactured by Covestro); or - Commercially available triisocyanates, for example, in particular, 4,4’,4”-triphenylmethane triisocyanate (available as Desmodur® RE (manufactured by Covestro)), or tris(p-isocyanatophenyl) thiophosphate (available as Desmodur® RFE (manufactured by Covestro)).

[0093] Polymers containing suitable isocyanate groups are, in particular, reaction products of at least one polyol and a stoichiometric excess of at least one diisocyanate. The reaction is preferably carried out in the absence of moisture at a temperature in the range of 20 to 160 °C, particularly 40 to 140 °C, and optionally in the presence of a suitable catalyst.

[0094] The NCO / OH ratio is preferably in the range of (1.3 / 1) to (10 / 1). Monomeric diisocyanates remaining in the reaction mixture after reaction with the OH groups can be removed, in particular, by distillation.

[0095] If the monomeric diisocyanate is to be removed from the polymer, the NCO / OH ratio in the reaction is preferably in the range of (3 / 1) to (10 / 1), particularly (4 / 1) to (7 / 1). The polymer containing isocyanate groups thus obtained preferably contains no more than 0.5% by weight, more preferably no more than 0.3% by weight of monomeric diisocyanate after distillation. In this case, the monomeric diisocyanate is removed, in particular, by short-path vacuum distillation.

[0096] If the monomeric diisocyanate is not to be removed from the polymer, the NCO / OH ratio in the reaction is preferably in the range of (1.3 / 1) to (2.5 / 1). Such polyetherurethane polymers contain, in particular, no more than 3% by weight, preferably no more than 2% by weight of monomeric diisocyanate.

[0097] Preferred monomeric diisocyanates are the aromatic, aliphatic or cycloaliphatic diisocyanates already mentioned, in particular MDI, TDI, HDI, HMDI or IPDI, or mixtures thereof.

[0098] Particularly preferred are 4,4'-MDI, TDI or IPDI.

[0099] Suitable polyols are commercially available polyols, or mixtures thereof, especially the following: - Polyether polyols, in particular polyoxyalkylene diols and / or polyoxyalkylene triols, in particular those obtained by the polymerization reaction of ethylene oxide, or 1,2-propylene oxide, or 1,2- or 2,3-butylene oxide, or oxetane, or tetrahydrofuran, or mixtures thereof, where they can be polymerized with the aid of starter molecules having two or three active hydrogen atoms, in particular water, ammonia, or starter molecules such as compounds having two or more OH or NH groups, for example: ethane-1,2-diol, propane-1,2- or -1,3-diol, neopentyl glycol, diethylene glycol, triethylene glycol, isomeric dipropylene glycols or tripropylene glycols, isomeric butanediols, pentanediols, hexanediols, heptanediols, octanediols, nonanediols, decanediols, undecanediols, 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 of the abovementioned compounds. Also suitable are polyether polyols containing polymer particles dispersed therein, in particular those containing styrene / acrylonitrile (SAN) particles or polyurea or polyhydrazodicarbonamide (PHD) particles. Preferred polyether polyols are polyoxypropylene diols or polyoxypropylene triols, or those called ethylene oxide-terminated EO-capped or EO-tipped polyoxypropylene diols or triols. The latter are mixed polyoxyethylene / polyoxypropylene polyols which are obtained in particular by further alkoxylation of polyoxypropylene diols or triols with ethylene oxide when their polypropoxylation reaction is complete, and as a result have primary hydroxyl groups. Preferred polyether polyols have an unsaturation of less than 0.02 meq / g, in particular less than 0.01 meq / g. - Polyester polyols (also called oligoesterols), prepared by known processes, in particular by polycondensation of hydroxycarboxylic acids or lactones, or by polycondensation of aliphatic and / or aromatic polycarboxylic acids with dihydric or polyhydric alcohols. Preferred are dihydric alcohols such as, in particular, ethane-1,2-diol, diethylene glycol, propane-1,2-diol, dipropylene glycol, butane-1,4-diol, pentane-1,5-diol, hexane-1,6-diol, neopentyl glycol, glycerol, 1,1,1-trimethylolpropane, or mixtures of the above-mentioned alcohols, reacted with organic dicarboxylic acids or their anhydrides or esters such as, in particular, succinic acid, glutaric acid, adipic acid, suberic acid, sebacic acid, dodecanedicarboxylic acid, maleic acid, fumaric acid, phthalic acid, isophthalic acid, terephthalic acid, cyclohexane-1,2-dicarboxylic acid, cyclohexane-1,3-dicarboxylic acid or -1,4-dicarboxylic acid, or mixtures of the above-mentioned acids, to give polyester diols, or lactones such as, in particular, ε-caprolactone, to give polyester polyols. Particularly preferred are polyester polyols formed from adipic acid or sebacic acid or dodecanedicarboxylic acid and hexanediol or neopentyl glycol. - Polycarbonate polyols, for example those obtained by reacting the above-mentioned alcohols (used to form the polyester polyol) with dialkyl carbonates, diaryl carbonates, or phosgene. - Block copolymers carrying at least two OH groups and having at least two different blocks of the polyether, polyester and / or polycarbonate structure of the above-mentioned type, in particular polyether polyester polyols. - Polyacrylate or polymethacrylate polyols. - Polyhydroxy-functionalized oils, such as natural oils, especially castor oil; or polyols obtained by chemically modifying natural oils (referred to as oleochemical polyols), such as epoxypolyesters or epoxypolyethers obtained by epoxidizing unsaturated oils and then ring-opening with carboxylic acids or alcohols, or polyols obtained by hydroformylating and hydrogenating unsaturated oils; or polyols obtained from natural oils by a decomposition process such as alcoholysis or ozonolysis and then subjecting the chemical bonds, such as the decomposition reaction products or their derivatives thus obtained, to transesterification or dimerization. Preferred decomposition reaction products of natural oils are, in particular, fatty acids and fatty alcohols and furthermore fatty acid esters, especially methyl esters (FAME), which can be derivatized to hydroxy fatty acid esters, for example by hydroformylating and hydrogenating. - Polyhydrocarbon polyols (also referred to as oligohydrocarbinols), such as, in particular, polyhydroxy-functionalized polyolefins, polyisobutylene, polyisoprene; polyhydroxy-functionalized ethylene / propylene, ethylene / butylene or ethylene / propylene / diene copolymers (for example those from Kraton Polymers); polyhydroxy-functionalized polymers of dienes, especially 1,3-butadiene (which can also be produced, in particular, by anionic polymerization); polyhydroxy-functionalized copolymers of dienes, such as 1,3-butadiene or a diene mixture, with vinyl monomers such as styrene, acrylonitrile, vinyl chloride, vinyl acetate, vinyl alcohol, isobutylene or isoprene, in particular polyhydroxy-functionalized acrylonitrile / butadiene copolymers which can be produced from epoxides or amino alcohols and carboxyl-terminated acrylonitrile / butadiene copolymers (for example those commercially available from Emerald Performance Materials under the names Hypro® CTBN or CTBNX or ETBN); or hydrogenated polyhydroxy-functionalized polymers or copolymers of dienes.

[0100] Particularly preferred are further mixtures of polyols.

[0101] Preferred are polyether polyols, polyester polyols, polycarbonate polyols, poly(meth)acrylate polyols, or polybutadiene polyols.

[0102] Particularly preferred are polyether polyols, polyester polyols, especially aliphatic polyester polyols, or polycarbonate polyols, especially aliphatic polycarbonate polyols.

[0103] Especially preferred are polyether polyols, especially polyoxyalkylene polyols.

[0104] Most preferred are polyoxypropylene diols or triols, or ethylene oxide-terminated polyoxypropylene diols or triols.

[0105] Preferred are polyols having an average molecular weight M in the range of 400 to 20000 g / mol, preferably 1000 to 15000 g / mol n thereof.

[0106] Preferred are polyols having an average OH functionality in the range of 1.6 to 3.

[0107] Preferred are polyols that are liquid at room temperature.

[0108] In order to produce a polymer containing isocyanate groups, it is also possible to use further partially the following bifunctional or polyfunctional alcohols: In particular, ethane-1,2-diol, propane-1,2-diol, propane-1,3-diol, 2-methylpropane-1,3-diol, butane-1,2-diol, butane-1,3-diol, butane-1,4-diol, pentane-1,3-diol, pentane-1,5-diol, 3-methylpentane-1,5-diol, neopentyl glycol, dibromoneopentyl glycol, hexane-1,2-diol, hexane-1,6-diol, heptane-1,7-diol, octane-1,2-diol, octane-1,8-diol, 2-ethylhexane-1,3-diol, diethylene glycol, triethylene glycol, dipropylene glycol, tripropylene glycol, cyclohexane-1,3-dimethanol or -1,4-dimethanol, ethoxylated bisphenol A, propoxylated bisphenol A, cyclohexanediol, hydrogenated bisphenol A, dimer fatty acid alcohol, 1,1,1-trimethylolethane, 1,1,1-trimethylolpropane, glycerol, pentaerythritol, sugar alcohol, for example in particular, xylitol, sorbitol, or mannitol, or sugar, for example in particular, sucrose, or alkoxylated derivatives of the above-mentioned alcohols, or mixtures of the above-mentioned alcohols.

[0109] The moisture-curing polyurethane composition preferably contains at least one polymer containing isocyanate groups.

[0110] The polymer containing isocyanate groups preferably has an average molecular weight M in the range of 1500 to 20000 g / mol, in particular 2000 to 15000 g / mol. n having.

[0111] The polymer containing isocyanate groups preferably has an isocyanate group content in the range of 0.5% to 10% by weight, in particular 1% to 5% by weight.

[0112] The polymer containing the isocyanate groups preferably has a low monomeric diisocyanate content, specifically less than 2% by weight, especially less than 1% by weight of monomeric diisocyanate.

[0113] It is preferred that the moisture-curing polyurethane composition further contains at least one additional component selected from fillers, plasticizers, further blocked amines (blocked amines), catalysts, and stabilizers.

[0114] Suitable fillers include, in particular, the following: ground or precipitated calcium carbonate (optionally coated with fatty acids, especially stearate), barite, quartz powder, silica sand, dolomite, wollastonite, calcined kaolin, layered silicates such as mica or talc, zeolite, aluminum hydroxide, magnesium hydroxide, silica (including silica micronized by the pyrolysis method), cement, gypsum, fly ash, industrially produced carbon black, graphite, metal powders such as aluminum, copper, iron, silver, or steel, PVC powder, or lightweight fillers such as hollow glass beads or gas-filled plastic spheres (microspheres), especially of the type obtainable under the trade name Expancel® (manufactured by Akzo Nobel).

[0115] Preferred are calcium carbonate (optionally coated with fatty acids, especially stearate), calcined kaolin, micronized silica, or industrially produced carbon black.

[0116] Suitable plasticizers include, in particular, the following: esters of carboxylic acids such as phthalates, in particular diisononyl phthalate (DINP), diisodecyl phthalate (DIDP) or di(2-propylheptyl) phthalate (DPHP), hydrogenated phthalates, or cyclohexane-1,2-dicarboxylate esters, in particular hydrogenated diisononyl phthalate or diisononyl cyclohexane-1,2-dicarboxylate (DINCH), terephthalates, in particular bis(2-ethylhexyl) terephthalate (DOTP), or diisononyl terephthalate (DINT), hydrogenated terephthalates or cyclohexane-1,4-dicarboxylate esters, in particular hydrogenated bis(2-ethylhexyl) terephthalate or bis(2-ethylhexyl) cyclohexane-1,4-dicarboxylate, or hydrogenated diisononyl terephthalate or diisononyl cyclohexane-1,4-dicarboxylate, isophthalates, trimellitates, adipates, in particular dioctyl adipate, azelates, sebacates, benzoates, glycol ethers, glycol esters, plasticizers having a polyether structure, in particular monools, diols or triols of polypropylene oxide having hydroxyl groups blocked, in particular in the form of acetate groups, organic phosphates or sulfonates, polybutene, polyisobutene, or plasticizers derived from natural oils, in particular epoxidized soybean oil or linseed oil.

[0117] Preferred plasticizers are phthalates, hydrogenated phthalates, adipates, or plasticizers having a polyether structure.

[0118] Suitable further blocked amines (blocked amines) are, in particular, oxazolidines or aldimines.

[0119] Preferred as further blocked amines (blocked amines) are bisoxazolidines of formula (VIII) or (IX):

Chemical formula

[0120] Further preferred as a further blocked amine is a monooxazolidine of the following formula: [Chemical formula] [wherein, L is an alkyl, cycloalkyl, or arylalkyl group having 1 to 8 carbon atoms, in particular methyl, ethyl, or n - butyl, and Q is as defined above].

[0121] Also preferred as a further blocked amine is [Chemical formula] an aldimine of, where y is 2 or 3, G is an organic group having 2 to 23 carbon atoms, and B is an organic group having 6 to 30 carbon atoms.

[0122] G is preferably an alkylene group optionally containing a cyclic component, or a divalent or trivalent polyoxyalkylene group having 5 to 15 carbon atoms, in particular 1,6 - hexylene, (1,5,5 - trimethylcyclohexan - 1 - yl)methane - 1,3, or an α,ω - polyoxypropylene having an average molecular weight M in the range of 170 to 300 g / mol n or an α,ω - polyoxypropylene having an average molecular weight M in the range of 330 to 500 g / moln It is tris(ω - polyoxypropylene) starting from trimethylolpropane and having

[0123] B is preferably an organic group having 7 to 22 carbon atoms, particularly 2,2 - dimethyl - 3-(N - morpholino)propylidene, 2,2 - dimethyl - 3 - lauroyloxypropylidene, benzylidene or a substituted benzylidene, particularly 4 - decylbenzylidene, 4 - undecylbenzylidene, 4 - dodecylbenzylidene, 4 - tridecylbenzylidene, or 4 - tetradecylbenzylidene (wherein the 4 - alkyl group may be branched in some cases).

[0124] The moisture - curable polyurethane composition particularly preferably contains at least one bisoxazolidine of formula (VIII) in which D is 1,6 - hexylene. Such a composition gives particularly high strength combined with high extensibility.

[0125] Suitable catalysts are catalysts for accelerating the reaction of isocyanate groups, particularly the following: organotin(IV) compounds such as, in particular, dibutyltin diacetate, dibutyltin dilaurate, dibutyltin dichloride, dibutyltin diacetylacetonate, dimethyltin dilaurate, dioctyltin diacetate, dioctyltin dilaurate, or dioctyltin diacetylacetonate, complexes of bismuth(III) or zirconium(IV), particularly those having ligands selected from alkoxides, carboxylates, 1,3 - diketonates, oxanates, 1,3 - ketoesters, and 1,3 - ketoamides, or compounds containing a tertiary amino group such as, in particular, 2,2’ - dimorpholinodiethyl ether (DMDEE).

[0126] Suitable catalysts are further additional catalysts for hydrolytic decomposition of aldimine groups such as, in particular, organic acids, in particular carboxylic acids such as 2-ethylhexanoic acid, lauric acid, stearic acid, isostearic acid, oleic acid, neodecanoic acid, benzoic acid, salicylic acid, or 2-nitrobenzoic acid, organic carboxylic anhydrides such as phthalic anhydride, hexahydrophthalic anhydride or hexahydromethylphthalic anhydride, carboxylic acids, organic sulfonic acids such as methanesulfonic acid, p-toluenesulfonic acid, or silyl esters of 4-dodecylbenzenesulfonic acid, sulfonic acid esters, other organic or inorganic acids, or mixtures of the above-mentioned acids and acid esters. Particularly preferred are carboxylic acids, in particular aromatic carboxylic acids such as benzoic acid, 2-nitrobenzoic acid, or in particular salicylic acid.

[0127] Also particularly preferred is a combination of a plurality of different catalysts.

[0128] Suitable stabilizers are in particular the following: stabilizers against oxidation, heat, light or UV rays, in particular titanium dioxide, iron oxide, zinc oxide, benzophenone, benzotriazole, compounds having a 2,6-di-tert-butylphenol group such as those known under the trade name Irganox (registered trademark) (manufactured by BASF), compounds having a 2,2,6,6-tetramethylpiperidine group, called HALS (hindered amine light stabilizer), such as those known under the trade name Tinuvin (registered trademark) (manufactured by BASF), or phosphorus-containing compounds such as those known under the trade name Irgafos (registered trademark) (manufactured by BASF).

[0129] The moisture-curing polyurethane composition may in particular further contain the following additives: - Inorganic or organic pigments, in particular titanium dioxide, chromium oxide, or iron oxide; - Fibers, in particular glass fibers, carbon fibers, metal fibers, ceramic fibers, polymer fibers such as polyamide fibers or polyethylene fibers, or natural fibers such as wool, cellulose, hemp, or sisal; - Nano fillers, such as graphene or carbon nanotubes; - Dyes; - Desiccants, especially molecular sieve powder, calcium oxide, highly reactive isocyanates such as p-tolyl isocyanate, monooxazolidine such as Incozol® 2 (manufactured by Incorez), or orthoformate esters; - Adhesion promoters, especially organoalkoxysilanes, especially epoxysilanes, such as, in particular, 3-glycidoxypropyltrimethoxysilane or 3-glycidoxypropyltriethoxysilane, (meth)acrylosilanes, anhydridesilanes, carbamatosilanes, alkylsilanes, or iminosilanes, or those in the form of oligomers of these silanes, or titanates; - Further catalysts that accelerate the reaction of isocyanate groups; - Rheology modifiers, especially thickeners, especially layered silicates such as bentonite, derivatives of castor oil, hydrogenated castor oil, polyamides, polyamide waxes, polyurethanes, urea compounds, fumed silica, cellulose ethers, or hydrophobically modified polyoxyethylene; - Solvents, especially acetone, methyl acetate, tert-butyl acetate, 1-methoxy-2-propyl acetate, ethyl 3-ethoxypropionate, diisopropyl ether, diethylene glycol diethyl ether, ethylene glycol diethyl ether, ethylene glycol monobutyl ether, ethylene glycol mono-2-ethylhexyl ether, acetals such as propylal, butyral, 2-ethylhexylal, dioxolane, glycerol formal, or 2,5,7,10-tetraoxaundecane (TOU), toluene, xylene, heptane, octane, naphtha, white spirit, petroleum ether or gasoline, especially Solvesso® grade (manufactured by Exxon), and propylene carbonate, dimethyl carbonate, butyrolactone, N-methylpyrrolidone, N-ethylpyrrolidone, p-chlorobenzotrifluoride, or benzotrifluoride; - Natural resins, oils such as rosin, shellac, linseed oil, castor oil, or soybean oil; - Non-reactive polymers, in particular homopolymers or copolymers of unsaturated monomers from the group comprising ethylene, propylene, butylene, isobutylene, isoprene, vinyl acetate, or alkyl (meth)acrylates, in particular polyethylene (PE), polypropylene (PP), polyisobutylene, ethylene / vinyl acetate copolymer (EVA), or atactic poly-α-olefin (APAO); - Flame retardant substances, in particular the aluminum hydroxide or magnesium hydroxide fillers mentioned above, and even more particularly organic phosphoric esters such as, in particular, triethyl phosphate, tricresyl phosphate, triphenyl phosphate, diphenylcresyl phosphate, isodecyldiphenyl phosphate, tris(1,3-dichloro-2-propyl) phosphate, tris(2-chloroethyl) phosphate, tris(2-ethylhexyl) phosphate, tris(chloroisopropyl) phosphate, tris(chloropropyl) phosphate, triphenyl phosphate with various degrees of isopropylation, mono-, bis-, or tris-(isopropylphenyl) phosphate, resorcinol bis(diphenyl phosphate), bisphenol A bis(diphenyl phosphate) or ammonium polyphosphate; - Additives, in particular wetting agents, leveling agents, defoaming agents, deaerating agents, or insecticides; Or further substances customary in moisture-curing polyurethane compositions.

[0130] Certain substances are preferably mixed into the composition after being dried chemically or physically.

[0131] The moisture-curing polyurethane composition is produced in particular while excluding moisture and is stored at room temperature in a moisture-tight container. Suitable moisture-tight containers are in particular metal and / or plastic, optionally coated, and specifically drums, containers, hobbocks, buckets, canisters, cans, bags, tubular bags, cartridges, or tubes.

[0132] The moisture-curing polyurethane composition may be in the form of a one-component composition, or may be in the form of a multi-component composition, particularly a two-component composition.

[0133] A composition called a "one-component" composition is one in which all the components of the composition are present in the same container and have storage stability as they are.

[0134] A composition called a "two-component" composition is one in which the components of the composition are present in the state of two different components, which are stored in separate containers and are not mixed with each other until immediately before or during the application of the composition.

[0135] The moisture-curing polyurethane composition is preferably a one-component composition. Given appropriate packaging and storage conditions, it typically has storage stability for several months, and up to one year or more at the longest.

[0136] When the moisture-curing polyurethane composition is applied, the curing process is initiated, whereby a cured composition is obtained.

[0137] In the case of a one-component composition, it is applied as it is, and then curing starts under the influence of moisture or humidity. For the purpose of accelerating curing, water and optionally a catalyst and / or an accelerator containing a curing agent can be incorporated into the composition at the time of application, or the composition can be brought into contact with such an accelerator component after the composition has been applied.

[0138] During curing, the isocyanate groups react with each other, either in parallel or sequentially, with hydrolyzable aldimine groups and optionally also blocked amino groups present under the influence of moisture to form urea groups. The combination of these and any other reactions of the isocyanate groups that lead to the curing of the composition is also called crosslinking.

[0139] The moisture required to cure the moisture-curing polyurethane composition is preferably incorporated into the composition through diffusion from the air (atmospheric moisture). As a result of this process, a solid layer of the cured composition (skin) is formed on the surface of the composition in contact with the atmosphere. Curing proceeds in the direction of diffusion from the outside to the inside, and the skin gradually thickens, and finally the entire applied composition is covered. It is also possible to additionally or entirely feed moisture from one or more substrates to which the composition has been applied into the composition, and / or to provide it from the vulcanization accelerator component, which is incorporated into the composition during application or brought into contact after application, for example by a painting method or a spraying method.

[0140] The moisture-curing polyurethane composition is preferably applied at ambient temperature, particularly in the range of about -10 to 50 °C, preferably in the range of -5 to 45 °C, particularly 0 to 40 °C.

[0141] It is preferable to cause the curing of the moisture-curing polyurethane composition at ambient temperature.

[0142] The moisture-curing polyurethane composition is preferably used as an adhesive or a sealant or a coating, particularly in the construction industry and the manufacturing industry, or in the manufacture of motor vehicles.

[0143] Particularly preferred is use as an elastic adhesive and / or sealant for the following: veneer bonding, assembly, bonding of installable components, module bonding, window glass bonding, joint sealing, body structure sealing, seam or cavity sealing, or elastic bonding in the manufacture of motor vehicles, for example, particularly for bonding and attaching parts such as plastic covers, trim strips, flanges, fenders, driver's seats, or other components that can be incorporated into the painted body of a motor vehicle, or bonding window glass to the body of a vehicle (said motor vehicle being particularly a passenger car, truck, bus, railway vehicle, or ship).

[0144] Also preferably, it is used as an elastic coating for protecting a floor surface or a wall surface, particularly as a so-called liquid coating film for sealing a roof, particularly a flat roof or a slightly inclined roof area, or a courtyard, or, for example, under tiles or ceramic slabs, in a humid compartment or in a kitchen, or for sealing water in a building interior or on a balcony, or as a seam seal, or, for example, for sealing leaks in a roof membrane or other elastic seals or for the purpose of repairing a seal or a coating.

Examples

[0145] In the following, working examples are shown for the purpose of further explaining the present invention described above. Needless to say, the present invention is not limited to those described working examples.

[0146] “Standard climatic conditions (SCC)” refers to a temperature of 23 ± 1°C and a relative atmospheric humidity of 50 ± 5%.

[0147] Unless otherwise specified, the chemicals used are manufactured by Sigma - Aldrich Chemie GmbH.

[0148] Description of measurement methods: The gas chromatogram (GC) was measured within a temperature range of 60 - 320°C, with a heating rate of 15°C / min and a holding time of 10 minutes at 320°C. The inlet temperature was 250°C. A Zebron ZB - 5 column (L = 30m, ID = 0.25mm, dj = 0.5μm) was used, and the gas flow rate was 1.5 mL / min. Detection was by the flame ionization method (FID). In addition, a mass spectrum (EI + ) was recorded to correspond the GC peaks to the chemical structures.

[0149] The infrared spectrum (FT - IR) was recorded as a neat film using a Bruker Alpha Eco - ATR FT - IR device. The absorption bands are represented by the wave number (cm -1 )

[0150] DSC (Differential Scanning Calorimetry) analysis was determined using a Mettler Toledo DSC 3+ 700 instrument, in a temperature range of 10 - 400 °C, at a heating rate of 4 K / min, using an adiabatic M20 pressure crucible (manufactured by TueV Sued (Switzerland)) (first run).

[0151] The amine value (including blocked amino groups) was determined by titration (using 0.1 N HClO4 in acetic acid against crystal violet).

[0152] Preparation of the aldol ester of formula (I): Example 1: Preparation of the reaction product of the present invention containing 2,2 - dimethyl - 3 - acetoxypropanal in the presence of triethylamine Step 1 (aldol reaction): A V4A steel reactor equipped with an addition system, a stirring system, a heating system, a cooling system, and a distillation column with a condenser, maintained under a nitrogen atmosphere, was charged with 297 kg of triethylamine (manufactured by BASF), 587 kg of paraformaldehyde (manufactured by Tennants Fine Chemicals), and 282 kg of deionized water, and they were mixed. While stirring the mixture, it was heated under reflux to 60 °C. Then, 1523 kg of isobutyraldehyde (manufactured by BASF) was metered in over 3 hours, during which the reaction mixture was maintained at 65 - 75 °C under reflux. After further refluxing for 30 minutes, no exotherm was observed anymore. Then, the system was switched to distillation, and its internal pressure was gradually reduced to distill off volatile substances, initially at 85 °C / 250 mbar and then at 100 °C / 50 mbar. 705 kg of distillate was collected (according to gas chromatography, unreacted isobutyraldehyde, water, and triethylamine occupied a significant portion). What remained in the reactor was 1924 kg of reaction mixture, which according to gas chromatography, contained approximately 88 wt% of 2,2 - dimethyl - 3 - hydroxypropanal (retention time, approximately 3.2 minutes) and approximately 4 wt% of triethylamine (retention time, 2.2 minutes).

[0153] Step 2 (Esterification): Next, the reactor was set to standard pressure using nitrogen and refluxed to raise the internal temperature to 110°C. Then, the internal pressure was reduced to 250 mbar, and 2076 kg of acetic anhydride (manufactured by BP Chemicals) was added and mixed for 1 hour. Subsequently, volatile substances were removed from the reaction mixture. For this purpose, the reactor was set to fractional distillation (80% reflux), and the contents were distilled at a top temperature of approximately 78°C. When the top temperature reached 80°C, the internal pressure of the reactor was gradually further reduced, and distillation was continued each time until the top temperature reached 80°C again. As soon as the top temperature exceeded 80°C at an internal pressure of 30 mbar, distillation, i.e., the removal of volatile substances from the reaction mixture, was terminated. A total of 2134 kg of distillate was collected (according to gas chromatography, it was unreacted acetic anhydride, acetic acid, triethylamine, and 2,2-dimethyl-3-acetoxypropanal). Then the reaction product was cooled and stored under a nitrogen atmosphere.

[0154] 1851 kg of a transparent, light yellow liquid with a mild fruity odor was obtained. According to gas chromatography, the reaction product contained approximately 78% by weight of 2,2-dimethyl-3-acetoxypropanal (retention time, 4.8 minutes), approximately 5.7% by weight of the triester of formula (V) (retention time, 10.9 minutes), and approximately 6.3% by weight of the acetal of formula (VI) (retention times, 6.4 minutes and 6.6 minutes). Hereafter, this will be referred to as the "reaction product from Example 1". FT-IR: 2973, 2938, 2877, 2818, 2716, 1728, 1473, 1374, 1228, 1160, 1118, 1040, 892, 775.

[0155] The DSC of the reaction product was recorded and is shown in Figure 1. A weak exotherm of 20 kJ / kg was observed in the region of 105 - 155°C.

[0156] Purification of the reaction product by top distillation: (Comparative Example) 500 g of the reaction product obtained from Example 1 was distilled at 120 - 130 °C under reduced pressure in a round-bottom flask equipped with a distillation column. Thereby, a distillate of 370.4 g (= 2,2-dimethyl-3-acetoxypropanal from Example 1 distilled at the top of the column) was obtained at a top temperature of 84 - 87 °C, 30 mbar, and 60% reflux. According to gas chromatography, it contained approximately 94% by weight of 2,2-dimethyl-3-acetoxypropanal.

[0157] A first fraction of 73.8 g (= first run) was collected at a top temperature of 76 - 80 °C, 30 mbar, and 80% reflux. According to gas chromatography, this contained approximately 56% by weight of 2,2-dimethyl-3-acetoxypropanal, approximately 17% by weight of acetic acid, and approximately 18% by weight of triethylamine. What remained as a residue was 55.8 g and had a 2,2-dimethyl-3-acetoxypropanal content of 0.8% by weight.

[0158] Example 2: (Comparative example) Preparation of 2,2-dimethyl-3-acetoxypropanal in the presence of an acid A round-bottom flask equipped with a distillation column and a water separator was charged with 100 g of cyclohexane, 144.0 g of paraformaldehyde, 403.7 g of acetic acid, and 6.3 g of p-toluenesulfonic acid under a nitrogen atmosphere and mixed. The mixture was heated under reflux to 60 °C while stirring well, and 346.4 g of isobutyl aldehyde was gradually added thereto so that the internal temperature did not exceed 75 °C. Then the system was switched from reflux to water separation and gradually heated to reach an internal temperature of 100 °C. When the internal temperature reached 100 °C, the internal pressure was gradually lowered while taking care to maintain the internal temperature at about 100 °C. At the point where the internal pressure was 600 mbar, 81 g of water was separated. Then the system was switched from water separation to distillation, and the internal pressure was further lowered while taking care to maintain the internal temperature at about 100 °C. When the internal pressure was 30 mbar and the top temperature of the column was 67 °C, most of the excess acetic acid was removed. The reaction product was cooled and stored under a nitrogen atmosphere. The collected distillate consisted mostly of cyclohexane and small amounts of water, isobutyl aldehyde, and acetic acid according to gas chromatography.

[0159] 576 g of a dark liquid having a pungent odor was obtained. According to gas chromatography, the reaction product contained about 61.7% by weight of 2,2-dimethyl-3-acetoxypropanal (retention time, 4.8 minutes).

[0160] The DSC of the reaction product from Example 2 was recorded and is shown in Figure 2. A strong exotherm of 530 kJ / kg was observed in the region of 100 to 400 °C.

[0161] Preparation of blocked amine (blocked amine): Aldimine A1: (from the reaction product of the present invention) N,N'-bis(2,2-dimethyl-3-acetoxypropylidene)-3-aminomethyl-3,5,5-trimethylcyclohexylamine A round-bottomed flask was charged with 373.0 g of the reaction product from Example 1 (containing about 78% by weight of 2,2-dimethyl-3-acetoxypropanal) under a nitrogen atmosphere. Then, while stirring well, 170.3 g (1 mol) of 3-aminomethyl-3,5,5-trimethylcyclohexylamine (Vestamin® IPD, manufactured by Evonik) was added, and then volatile substances were removed at 80 °C under a vacuum of 10 mbar. As a result, 497 g of a transparent, light yellow, low-viscosity liquid having a mild fruity odor and an amine value of 223 mg KOH / g (which corresponds to a calculated aldimine equivalent of 252 g / equivalent) was obtained.

[0162] Aldimine R1: (Comparative example, from the purified reaction product) N,N'-Bis(2,2-dimethyl-3-acetoxypropylidene)-3-aminomethyl-3,5,5-trimethylcyclohexylamine A round-bottomed flask was charged with 293 g of the 2,2-dimethyl-3-acetoxypropanal distilled from the top of the column from Example 1 under a nitrogen atmosphere. Then, while stirring well, 170.3 g (1 mol) of 3-aminomethyl-3,5,5-trimethylcyclohexylamine (Vestamin® IPD, manufactured by Evonik) was added, and then volatile substances were removed at 80 °C under a vacuum of 10 mbar. As a result, 418 g of an almost colorless, low-viscosity liquid having a mild fruity odor and an amine value of 262 mg KOH / g (which corresponds to a calculated aldimine equivalent of 214 g / equivalent) was obtained.

[0163] Moisture-curing polyurethane composition: Compositions Z1 and Z2 For each composition, the following components were mixed in a centrifugal mixer while excluding moisture to form a visually homogeneous liquid: 213.7 g of a polymer containing isocyanate groups and having an NCO content of 3.7 wt% (based on polyoxypropylene diol having an OH number of 56 mg KOH / g and toluene diisocyanate (Desmodur® T80P, manufactured by Covestro)), 61.3 g of a crosslinking agent (Desmodur® L67 MPA / X, manufactured by Covestro), 73 g of a plasticizer, 149 g of a solvent, 19 g of a thickener, 417 g of an inorganic filler, and 0.5 g of salicylic acid.

[0164] In contrast, for Composition Z1, 67.7 g of aldimine A1 or, for Composition Z2, 57.5 g of aldimine R1 was further added.

[0165] Each composition was stored in a sealed metal container with moisture excluded and finally the following tests were carried out.

[0166] Viscosity was measured at 20 °C using a Rotothinner: "freshly" refers to the viscosity measured 24 hours after composition manufacture. "4 weeks at 40 °C" and "8 weeks at 40 °C" refer to the viscosities after storage at 40 °C in a sealed container for 4 weeks and 8 weeks, respectively.

[0167] The curing rate ("BK drying time") was measured under standard climatic conditions using a Beck-Koller drying time recorder in accordance with ASTM D5895. The result of Phase 2 corresponds to the skin-over time (tack-free time) of the composition.

[0168] Through-curing was determined by shaping the composition into a cylinder with a diameter of 40 mm and a height of 4 mm, leaving it standing under standard climatic conditions (SCC) or at 5 °C / 80% relative humidity, and after 24 hours or 48 hours cutting it open and measuring the thickness of the cured layer formed on the surface of the composition. The results are reported as "24 hours, SCC" and "48 hours, SCC", and "48 hours, 5 °C" in accordance with the curing time and climatic conditions.

[0169] For the measurement of mechanical properties, a two-layer cured film was prepared for each composition. To do this, using a doctor blade, a first layer with a thickness of 800 μm was applied, stored for 24 hours under standard climatic conditions, and then, using a doctor blade, a second layer with a thickness of 400 μm was applied at an angle of 90 degrees to the first layer. This two-layer film was stored for a further 24 hours under standard climatic conditions and then stored at 60 °C for 24 hours in an air-circulation oven. After a further 24 hours under standard climatic conditions had elapsed, test pieces in the shape of strips with a length of 100 mm and a width of 25 mm were punched out from the film, and using these, in accordance with DIN EN 53504, at a strain rate of 180 mm / min and an orbit length of 60 mm, the tensile strength and elongation at break were measured.

[0170] The appearance was judged visually for the films prepared for the measurement of mechanical properties.

[0171] The odor was evaluated by smelling, at a distance of approximately 100 mm, a freshly applied flat composition with a diameter of approximately 150 mm with the nose.

[0172]

Table 1

[0173] From Table 1, it can be seen that the reaction product of the present invention from Example 1 has excellent compatibility for use as a blocked amine / potential curing agent in a one-component moisture-curing composition as it is, i.e., without further purification by top-of-column distillation. Composition Z1 shows even better properties than composition Z2 containing aldimine R1 derived from 2,2-dimethyl-3-acetoxypropanal purified by top-of-column distillation in some cases, surprisingly. Specifically, composition Z1 shows lower viscosity and particularly high elongation even after storage, while maintaining other properties equally.

[0174] Compositions Z1 and Z2 are suitable, in particular as a coating film or coating, especially as a so-called liquid coating film for sealing roofs, bridges, terraces, etc.

Claims

1. A method for preparing an aldol ester of the following formula (I), comprising: 【Chemical 1】 (wherein, R １ and R ２ are the same or different alkyl groups having 1 to 4 carbon atoms, or together represent an alkylene group having 4 to 6 carbon atoms, and R ３ is an optionally halogenated hydrocarbyl group having 1 to 17 carbon atoms), at least one carboxylic acid anhydride of the following formula (II) 【Chemical 2】 at least one aldol of the following formula (III), optionally in oligomeric form, [Chemical Formula 3] reacted with heating in the presence of a basic catalyst having a pKa of at least 8 for the conjugate acid, characterized in that method.

2. R １ and R ２ The method according to claim 1, characterized in that each of them is methyl.

3. R ３ The method according to claim 1 or 2, characterized in that R is an alkyl group having 1 to 7 carbon atoms or phenyl, especially methyl.

4. The method according to any one of claims 1 to 3, characterized in that the basic catalyst has a pKa of at least 9, particularly at least 10, for the conjugate acid.

5. The method according to any one of claims 1 to 4, characterized in that the basic catalyst is triethylamine.

6. The method according to any one of claims 1 to 5, characterized in that it is carried out at a temperature in the range of 80 to 150 °C, particularly 100 to 130 °C.

7. The method according to any one of claims 1 to 6, characterized in that it is carried out without using an organic solvent or a co-removing agent.

8. The aldol of formula (III) is used as a component of a reaction mixture obtained from the reaction of formaldehyde, optionally in the form of paraformaldehyde or trioxane, with at least one aldehyde of the following formula (IV) in the presence of a basic catalyst having a pKa of at least 8 for the conjugate acid: 【Chemical Formula 4】

9. The method according to any one of claims 1 to 8, characterized in that it is carried out in the following two-step process: (i) In the first step, the basic catalyst and formaldehyde, particularly formaldehyde in the form of paraformaldehyde, are initially charged, and then at least one aldehyde of the following formula (IV) [Chemical Formula 5] is added in a stoichiometric excess with respect to formaldehyde at a temperature in the range of 60 to 90 °C to form the aldol of formula (III) as a result, and then volatile substances are removed from the reaction mixture, and (ii) In the second step, the reaction mixture thus obtained is reacted with the carboxylic acid anhydride of formula (II) at a temperature in the range of 100 to 130 °C, and volatile substances are removed from the reaction mixture during and / or after the reaction.

10. A reaction product obtained by the method according to any one of claims 1 to 9, characterized by comprising 60% to 95% by weight of the aldol ester of the formula (I) and 5% to 40% by weight of other esters, aldehydes and / or acetals not corresponding to the formula (I).

11. A reaction product according to claim 10, characterized by comprising a triester of the following formula (V) and / or an acetal of the following formula (VI), in particular 0.1% to 20% by weight of the triester of the following formula (V) and 1% to 20% by weight of the acetal of the following formula (VI): 【Chemical Formula 6】

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