Novel two-component outer coating containing polyaspartate ester

Abstract

The present invention relates to a two-component external coating system comprising a polyaspartic acid ester containing only small amounts of diacryloyl fumarate esters, a process for its preparation and its use in the production of coatings, in particular for protection against corrosion, and in the field of general industrial coatings or ACE (agriculture, construction and civil engineering equipment), as well as the use of substrates coated therewith.

Description

Technical Field

[0001] The present invention relates to a two-component topcoat system comprising a polyaspartic acid ester containing only a small amount of dialkyl fumarate, a method for producing the same, and its use in the production of coatings, in particular a method for corrosion protection, and in the fields of ACE (agriculture, construction and geotechnical equipment), and for use in substrates coated thereby.

Background Art

[0002] Two-component (2C) coating compositions comprising a polyisocyanate component in combination with a component reactive towards isocyanate groups, in particular a polyhydroxyl component, as binder have been known for a long time. They are suitable for the production of high-quality coatings that are hard, elastic, abrasion-resistant and solvent-resistant, and can be adjusted, inter alia, to be weather-resistant.

[0003] Within the scope of this 2C polyurethane coating technology, certain ester-containing secondary polyamines have been established in recent years, and so-called polyaspartic acid esters or polyaspartates are particularly suitable as binders in low-solvent or solvent-free (high-solids) coating compositions in combination with paint polyisocyanates, enabling rapid curing of the coatings at low temperatures.

[0004] In addition to the above-mentioned rapid curing of these coatings, the use of such polyaspartic acid esters in topcoats enables a very attractive reduced layer structure for use in the field of topcoats. However, in the fields of anticorrosion and ACE (agriculture, construction, geotechnical equipment), conventional polyaspartic acid-based topcoats have not been able to be established because they lose their gloss. Therefore, there has long been a desire in the market for colored polyaspartic acid-based topcoats with improved gloss retention.

[0005] The use of polyaspartate esters in 2C coating compositions, either alone or in mixtures with further components that are reactive to isocyanate groups, is described, for example, in EP0403921, EP0639628, EP0667362, EP0689881, US5214086, EP069696, EP0596360, EP0893458, DE19701835, EP0470461, WO15130501, WO15130502 and US5243012.

[0006] The preparation of amino-functional aspartates is known in itself. Synthesis is carried out by the addition of a primary polyamine to the activated carbon-carbon double bond of a vinyl carbonyl compound, such as maleic acid or fumarate esters, which is well described in the literature (Houben-Weyl, Meth.d.Org.Chemie vol.11 / 1, 272 (1957), Usp.Khim. 1969, 38, 1933). If only one amino group of the polyamine reacts with the double bond of the vinyl carbonyl compound, this reaction can result in the formation of a polyaspartate ester having a primary amino group as a byproduct. In commercially available polyaspartates, maleic acid esters are used as the vinyl carbonyl compound. During the preparation of polyaspartates based on maleic acid esters, retro-Michael addition may occur as a further undesirable side reaction, where the elimination of the polyamine leads to the formation of dialkyl fumarate as a byproduct. Therefore, a typical method for producing polyaspartate esters requires a storage period of 4 to 6 weeks after the majority of the reactants have reacted with each other. During this time, the product undergoes so-called maturation, which is evident in the stabilization of viscosity. During this time, the conversion rate continues to increase, and the dialkyl fumarate content also decreases. This storage period of several weeks incurs considerable logistical costs during production. The product is not shipped to the customer until the end of the storage period, but it still contains a considerable amount of dialkyl fumarate, which can cause severe sensitization. After maturation, the polyaspartate esters thus prepared typically still contain residual amounts of fumarate ranging from 3 to 20 weight percent. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] EP0403921 [Patent Document 2] EP0639628 [Patent Document 3] EP0667362 [Patent Document 4] EP0689881 [Patent Document 5] US5214086 [Patent Document 6] EP069696 [Patent Document 7] EP0596360 [Patent Document 8] EP0893458 [Patent Document 9] DE19701835 [Patent Document 10] EP0470461 [Patent Document 11] WO15130501 [Patent Document 12] WO15130502 [Patent Document 13] US5243012 [Non-patent literature]

[0008] [Non-Patent Document 1] Houben-Weyl, Meth.d.Org.Chemie vol.11 / 1, 272(1957), Usp.Khim.1969,38,1933 [Overview of the project] [Problems that the invention aims to solve]

[0009] The object of the present invention was to provide a polyaspartate ester-based coating composition for producing a gloss-stable colored topcoat. [Means for solving the problem]

[0010] Surprisingly, it has been found that this object can be achieved by a polyaspartic acid ester-based coating composition with a significantly reduced dialkyl fumarate content. According to the present invention, the dialkyl fumarate content in the polyaspartic acid ester component is 0.01 to 1.2% by weight, preferably 0.01 to 1% by weight, more preferably 0.01 to 0.1% by weight, and these values can be reduced by a special distillation process.

[0011] [ The theoretical possibility of treating polyaspartic acid esters by distillation is described, for example, in EP0403921. This disclosure gives no examples and does not specify the distillation method. Furthermore, EP0403921 does not describe polyaspartic acid esters having a maximum dialkyl fumarate content of 1.2% by weight, and it is needless to say that it brings about an improvement in the gloss stability of these coatings, especially in the production of colored topcoats.

[0012] DE102006002153 likewise describes, in Comparative Example III, polyaspartic acid esters released from dialkyl fumarates by distillation. Again, there is no mention or suggestion of the use of polyaspartic acid esters having a dialkyl fumarate content reduced according to the present invention or of the effects achievable thereby in the production of colored topcoats.

[0013] WO2018 / 074884 and WO2018 / 074885, which were not yet published as patents at the time of filing the patent application of the present invention, likewise describe the distillation of polyaspartic acid esters, and WO2018074884 also describes its use in coating compositions. Neither of the two documents describes colored topcoats based on these purified esters.

Mode for Carrying Out the Invention

[0014] The present invention relates to a two-component coating composition (2C coating composition) comprising the following; a) At least one polyaspartic acid ester-containing component A, b) At least one polyisocyanate component B, c) Optionally, different from A, one or more components C that are reactive towards isocyanate groups, d) At least one inorganic and / or organic pigment, preferably in a proportion of at least 3% by weight (≧3% by weight) based on the total weight of the two-component composition (component D1), and, Optionally, other auxiliaries and additives (component D2).

[0015] In the context of the present invention, the polyaspartic acid ester-containing component A is One or more polyaspartic acid esters of general formula (I)

Chemical formula

Chemical formula

[0016] Polyaspartate ester-containing component A is a composition comprising one or more polyaspartate esters of general formula (I) and optionally general formula (II), where R1 and R2 are preferably the same or different alkyl groups having 1 to 18 carbon atoms each, preferably the same or different alkyl groups having 1 to 8 carbon atoms each, and most preferably, each of which is an alkyl group such as methyl, ethyl, propyl, isopropyl, butyl, or isobutyl. Ethyl is most preferred.

[0017] Polyaspartate ester-containing component A is a composition comprising one or more polyaspartate esters of general formula (I) and optionally general formula (II), where X is an organic group obtained by removing a primary amino group from a polyamine bonded to a corresponding (cyclo)aliphatic or aromaticaliphatic group having a primary amino group, and is selected from the group of all known polyamines having a primary amino group conforming to the following general formula (III). Examples include the following compounds: ethylenediamine, 1,2-diaminopropane, 1,4-diaminobutane, 1,5-diaminopentane, 2,5-diamino-2,5-dimethylhexane, 1,5-diamino-2-methylpentane (Dytek® A, manufactured by Invista), 1,6-diaminohexane, 2,2,4-and / or 2,4,4-trimethyl-1,6-diaminohexane, 1,11-diaminoundecane, 1,12-diaminododecane or triaminononane, etheramines such as 4,9-dioxadodecane-1,12-diamine, 4,7,10-trioxatridecane-1,13-diamine, or high molecular weight polyether polyamines having aliphatic-linked primary amino groups, such as those marketed by Huntsman under the name Jefamin®. Aliphatic polycyclic polyamines such as tricyclodecan bismethylamine (TCD diamine) or bis(aminomethyl)norbornane, amino-functional siloxanes, such as diaminopropylsiloxane G10 DAS (Momentive), and oleoalkyl-based amines, such as Solvay's fentamine and Croda's priamine, are also available.

[0018] The polyaspartate ester-containing component A is preferably a composition comprising one or more polyaspartate esters of general formula (I) and optionally general formula (II), where X is an organic group obtained by removing a primary amino group from one of the polyamines of general formula (III), where m=2 and X is a cyclic hydrocarbon group comprising at least one cyclic carbon ring. Examples of diamines that are particularly preferred for use include 1-amino-3,3,5-trimethyl-5-aminomethylcyclohexane (IPDA), 2,4- and / or 2,6-hexahydrotolylenediamine (H6-TDA), isopropyl-2,4-diaminocyclohexane and / or isopropyl-2,6-diaminocyclohexane, 1,3-bis(aminomethyl)cyclohexane, 2,4'- and / or 4,4'-diaminodicyclohexylmethane, 3,3'-dimethyl-4,4'-diaminodicyclohexylmethane (Laromin® C260, BASF AG), isomers of diaminodicyclohexylmethane substituted with methyl groups in the ring (=C-monomethyl-diaminodicyclohexylmethane), 3(4)-aminomethyl-1-methylcyclohexylamine (AMCA), and aromatic aliphatic diamines such as 1,3-bis(aminomethyl)benzene and m-xylylenediamine.

[0019] Similarly, polyaspartate ester-containing component A is preferably a composition comprising one or more polyaspartate esters of general formula (I) and optionally general formula (II), where X is an organic group obtained by removing a primary amino group from one of the polyamines of general formula (III), and is selected from the following group: polyether polyamines having aliphatic-linked primary amino groups, 1,2-diaminopropane, 1,4-diaminobutane, 1,6-diaminohexane, 1,5-diamino-2-methylpentane, 2 ,5-diamino-2,5-dimethylhexane, 2,2,4-and / or 2,4,4-trimethyl-1,6-diaminohexane, 1,11-diaminoundecane, 1,12-diaminododecane, 1-amino-3,3,5-trimethyl-5-aminomethylcyclohexane, 2,4-and / or 2,6-hexahydrotolylenediamine, 1,5-diaminopentane, 2,4'-and / or 4,4'-diaminodicyclohexylmethane, or 3,3'-dimethyl-4,4'-diaminodicyclohexylmethane. Particularly preferred are 3,3'-dimethyl-4,4'-diaminodicyclohexylmethane, 1,5-diaminopentane, 2,4'- and / or 4,4'-diaminodicyclohexylmethane, 1,5-diamino-2-methylpentane, and very particularly preferred are 2,4'- and / or 4,4'-diaminodicyclohexylmethane.

[0020] Polyaspartate ester-containing component A is particularly preferably a composition comprising one or more polyaspartate esters of general formula (I) and optionally general formula (II), where X is an organic group obtained by removing a primary amino group from one of the polyamines of general formula (III), and is selected from the following group: These are polyether polyamines having aliphatic-linked primary amino groups, 1,2-diaminopropane, 1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane, 1,5-diamino-2-methylpentane, 2,5-diamino-2,5-dimethylhexane, 2,2,4-and / or 2,4,4-trimethyl-1,6-diaminohexane, 1,11-diaminoundecane, 1,12-diaminododecane, 1-amino-3,3,5-trimethyl-5-aminomethylcyclohexane, 2,4-and / or 2,6-hexahydrotolylenediamine, 2,4'-and / or 4,4'-diaminodicyclohexylmethane, or 3,3'-dimethyl-4,4'-diaminodicyclohexylmethane.

[0021] Polyaspartate ester-containing component A is most preferably a composition comprising one or more polyaspartate esters of general formula (I) and optionally general formula (II), where X is an organic group obtained by removing a primary amino group from one of the polyamines of general formula (III), and is selected from the following group: 3,3'-dimethyl-4,4'-diaminodicyclohexylmethane, 2,4'- and / or 4,4'-diaminodicyclohexylmethane, 1,5-diamino-2-methylpentane. The index m is an integer greater than 1, preferably 2.

[0022] If polyaspartate ester-containing component A contains one or more polyaspartate esters of general formula (II), these are present in proportion to >0%, preferably 0.1% or more (≧0.1%), more preferably 1% or more (≧1%), most preferably 4% or more (≧4%) of the area by GC, and 20% or less (≦20%), more preferably 15% or less (≦15%) (measured as area %) of the gas chromatogram, where the sum of the areas by GC of the two compounds of general formulas (I) and (II) is 100%. Any combination of the specified upper and lower limits is possible. All possible combinations are considered disclosed.

[0023] Polyaspartate ester-containing component A is preferably a composition comprising one or more polyaspartate esters of general formula (I) and optionally (II), where the proportion of dialkyl fumarate is 0.01% to 1.2% by weight (≧0.01% to 1.2% by weight≦), preferably 0.01% to 1% by weight (≧0.01% to 1% by weight≦), and more preferably 0.01% to 0.1% by weight (≧0.01% to 0.1% by weight≦), based on the total weight of component A.

[0024] Polyaspartate ester-containing component A is particularly preferred, One or more polyaspartate esters of general formula (I); (wherein X is an m-valent organic group optionally containing one or more heteroatoms, obtained by removing a primary amino group from a polyether polyamine, 1,2-diaminopropane, 1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane, 1,5-diamino-2-methylpentane, 2,5-diamino-2,5-dimethylhexane, 2,2,4- and / or 2,4,4-trimethyl-1,6-diaminohexane, 1,11-diaminoundecane, 1,12-diaminododecane, 1-amino-3,3,5-trimethyl-5-aminomethylcyclohexane, 2,4- and / or 2,6-hexahydrotolylenediamine, 2,4'- and / or 4,4'-diaminodicyclohexylmethane or 3,3'-dimethyl-4,4'-diaminodicyclohexylmethane, R1 and R2 are identical or different alkyl groups each having 1 to 8 carbon atoms. m is an integer greater than 1), and One or more polyaspartic acid esters having a primary amino group of general formula (II) (In the formula, n is m-1, A composition comprising X, and the R1 and R2 groups are the same as described above, The proportion of the compound of general formula (II) corresponds to >0%, preferably 0.1% or more (≧0.1%), more preferably 1% or more (≧1%), and most preferably at least 4% (≧4%) of the area measured by GC (measured as area %). Here, the sum of the GC areas of the two compounds of general formulas (I) and (II) is 100%, and the dialkyl fumarate is present in component A in amounts ranging from 0.01% to 1.2% by weight (≧0.01% to ≦1.2% by weight) based on the total weight of component A.

[0025] A particularly preferred alternative embodiment corresponds to the above, but the polyaspartate ester having a primary amino group of general formula (II) present in polyaspartate ester-containing component A is absent.

[0026] Polyaspartate ester-containing component A is most preferably, One or more polyaspartate esters of general formula (I) (wherein X is an m-valent organic group obtained by removing a primary amino group from 3,3'-dimethyl-4,4'-diaminodicyclohexylmethane, 2,4'- and / or 4,4'-diaminodicyclohexylmethane, or 1,5-diamino-2-methylpentane, R1 and R2 are the same or different alkyl groups selected from the group consisting of methyl, ethyl, propyl, isopropyl, butyl, or isobutyl groups. m is 2), and One or more polyaspartic acid esters having a primary amino group of general formula (II) (In the formula, n is m-1, A composition comprising X, and the R1 and R2 groups are the same as described above, The proportion of the compound of general formula (II) is characterized by corresponding to >0%, preferably 0.1% or more (≧0.1%), more preferably 1% or more (≧1%), and most preferably at least 4% (≧4%) (measured as area %) of the gas chromatogram, as determined by GC. Here, the sum of the GC areas of the two compounds of general formulas (I) and (II) is 100%, and the dialkyl fumarate is present in component A in amounts ranging from 0.01% to 1% by weight (≧0.01% to 1% by weight≦) based on the total weight of component A.

[0027] A very preferred alternative embodiment corresponds to the above, but the polyaspartate ester having a primary amino group of general formula (II) present in polyaspartate ester-containing component A is absent.

[0028] Polyaspartate ester-containing component A is most preferably, One or more polyaspartate esters of general formula (I) [In the formula, X is an m-valent organic group obtained by removing a primary amino group from 3,3'-dimethyl-4,4'-diaminodicyclohexylmethane, 2,4'- and / or 4,4'-diaminodicyclohexylmethane, R1 and R2 are ethyl groups. m is 2, and One or more polyaspartic acid esters having a primary amino group of general formula (II) (In the formula, n is m-1, X, and the R1 and R2 groups are the same as described above.) A composition containing, The proportion of the compound of general formula (II) is characterized by corresponding to >0%, preferably 0.1% or more (≧0.1%), more preferably 1% or more (≧1%), and most preferably at least 4% (≧4%) (measured as area %) of the gas chromatogram, as determined by GC. Here, the sum of the GC areas of the two compounds of general formulas (I) and (II) is 100%, and the dialkyl fumarate is present in component A in amounts ranging from 0.01% to 0.1% by weight (≧0.01% to ≦0.1% by weight) based on the total weight of component A.

[0029] The most preferred alternative embodiment corresponds to the above, but the polyaspartate ester having a primary amino group of general formula (II) present in polyaspartate ester-containing component A is absent.

[0030] The polyaspartate ester-containing component A is preferably, The composition comprises one or more polyaspartate esters of general formula (I), and optionally one or more polyaspartate esters of formula (II) having a platinum-cobalt color index of 100 or less, more preferably 50 or less. The platinum-cobalt color index is measured according to DIN EN ISO 6271:2016-05.

[0031] Polyaspartate ester-containing component A, which includes one or more polyaspartate esters of general formula (I) and formula (II), can be prepared by the following process: Polyamines of general formula (III) [ka] [In the formula, X is an m-valent organic group, optionally containing one or more heteroatoms, obtained by removing a primary amino group from a polyamine having an amino group bonded to a (cyclo)aliphatic or aromaticaliphatic group, having a molecular weight in the range of 60 to 6000 g / mol, and may contain further functional groups that are reactive to isocyanate groups and / or inert at temperatures up to 100°C, where m is an integer greater than 1, preferably 2.] The compound of general formula (IV) [ka] [In the formula, R1 and R2 are the same or different organic groups, preferably the same or different alkyl groups having 1 to 18 carbon atoms each, more preferably the same or different alkyl groups having 1 to 8 carbon atoms each, most preferably alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl or isobutyl in each case, and most preferably ethyl.] The response was, and, This involves the removal of the unreacted fraction of the compound of general formula (IV) by distillation.

[0032] The above process for preparing polyaspartate ester-containing component A, which contains one or more polyaspartate esters of general formulas (I) and (II), is preferably carried out in two steps. In the first step, the compounds of general formulas (III) and (IV) are reacted at a temperature of 0°C to 100°C, preferably 20 to 80°C, more preferably 20 to 60°C, until the ratio of the equivalent amount of primary amino groups in the compound of general formula (III) to the equivalent amount of C=C double bonds in the compound of general formula (IV) is 1:1.2 to 1.2:1, but preferably 1:1.05 to 1.05:1, and the residual content of the compound of general formula (IV) is 2 to 15 weight percent, preferably 3 to 10 weight percent.

[0033] In the second step, the unreacted fraction of the compound of general formula (IV) is removed by distillation.

[0034] Polyaspartate ester-containing component A, which contains only polyaspartate ester of general formula (I) and does not contain formula (II), can be prepared by a similar method, but with an excess of the compound of general formula IV, i.e., the ratio of the equivalent amount of primary amino groups in the compound of general formula (III) to the equivalent amount of C=C double bonds in the compound of general formula (IV) is 1:10, preferably 1:5, and more preferably 1:2.

[0035] The appropriate conditions during distillation are a pressure range of 0.01 to 2 mbar, and a bottom outflow temperature of 170°C or less when exiting the distillation apparatus, and above the temperature obtained from the following equation (V):

number

[0036] Maintaining this pressure range ensures that the moderate temperature of the bottom outflow is sufficient to reduce the dialkyl fumarate content to the desired level, while also guaranteeing that the process remains usable on an industrial scale. At lower pressures, the gas density becomes too low, resulting in the need for very large equipment and making the process economically unprofitable.

[0037] The temperature of the bottom outflow is preferably ≤170°C, but at least 20K higher than the temperature derived from equation (V), and more preferably between 20K and 40K higher than the temperature derived from equation (V), but 170°C or lower.

[0038] The compounds of general formula (III) that can be used in the above process are all known polyamines having a primary amino group that matches general formula (III). Examples include the following compounds: ethylenediamine, 1,2-diaminopropane, 1,4-diaminobutane, 1,5-diaminopentane, 2,5-diamino-2,5-dimethylhexane, 1,5-diamino-2-methylpentane (Dytek® A, manufactured by Invista), 1,6-diaminohexane, 2,2,4-and / or 2,4,4-trimethyl-1,6-diaminohexane, 1,11-diaminoundecane, 1,12-diaminododecane or triaminononane, etheramines such as 4,9-dioxadodecane-1,12-diamine, 4,7,10-trioxatridecane-1,13-diamine, or high molecular weight polyether polyamines having aliphatic-bonded primary amino groups, such as those marketed under the name Jefamine® by Huntsman. Furthermore, aliphatic polycyclic polyamines such as tricyclodecan bismethylamine (TCD diamine) or bis(aminomethyl)norbornane, amino-functional siloxanes, such as diaminopropylsiloxane G10 DAS (Momentive), and oleoalkyl-based amines, such as Solvay's fentamine and Kuroda's priamine, can also be used.

[0039] In the above process, it is preferable to use a polyamine of general formula (III) in which m=2 and X is a cyclic hydrocarbon group having at least one cyclic carbon ring. Examples of diamines that are particularly preferred for use include 1-amino-3,3,5-trimethyl-5-aminomethylcyclohexane (IPDA), 2,4- and / or 2,6-hexahydrotolylenediamine (H6-TDA), isopropyl-2,4-diaminocyclohexane and / or isopropyl-2,6-diaminocyclohexane, 1,3-bis(aminomethyl)cyclohexane, 2,4'- and / or 4,4'-diaminodicyclohexylmethane, 3,3'-dimethyl-4,4'-diaminodicyclohexylmethane (Laromin® C260, BASF AG), isomers of diaminodicyclohexylmethane substituted with methyl groups in the ring (=C-monomethyl-diaminodicyclohexylmethane), 3(4)-aminomethyl-1-methylcyclohexylamine (AMCA), and aromatic aliphatic diamines such as 1,3-bis(aminomethyl)benzene and m-xylylenediamine.

[0040] In the process according to the present invention, it is also preferable to use a polyamine of general formula (III) selected from the following group: aliphatic-linked primary amino group polyether polyamine, 1,2-diaminopropane, 1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane, 1,5-diamino-2-methylpentane, 2,5-diamino-2,5-dimethylhexane, 2,2,4- and / or 2,4,4-trimethyl-1,6-diaminohexane, 1,11-diaminoundecane, 1,12-diaminododecane, 1-amino-3,3,5-trimethyl-5-aminomethylcyclohexane, 2,4- and / or 2,6-hexahydrotolylenediamine, 2,4'- and / or 4,4'-diaminodicyclohexylmethane, or 3,3'-dimethyl-4,4'-diaminodicyclohexylmethane. Particularly preferred are 3,3'-dimethyl-4,4'-diaminodicyclohexylmethane, 2,4'- and / or 4,4'-diaminodicyclohexylmethane, 1,5-diamino-2-methylpentane, and very particularly preferred is the use of 2,4'- and / or 4,4'-diaminodicyclohexylmethane.

[0041] In the process according to the present invention, it is particularly preferable to use a polyamine of general formula (III) selected from the following group: aliphatic-linked primary amino group polyether polyamine, 1,2-diaminopropane, 1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane, 1,5-diamino-2-methylpentane, 2,5-diamino-2,5-dimethylhexane, 2,2,4- and / or 2,4,4-trimethyl-1,6-diaminohexane, 1,11-diaminoundecane, 1,12-diaminododecane, 1-amino-3,3,5-trimethyl-5-aminomethylcyclohexane, 2,4- and / or 2,6-hexahydrotolylenediamine, 2,4'- and / or 4,4'-diaminodicyclohexylmethane, or 3,3'-dimethyl-4,4'-diaminodicyclohexylmethane.

[0042] In the method according to the present invention, it is very preferable to use a polyamine of general formula (III) selected from the group consisting of 3,3'-dimethyl-4,4'-diaminodicyclohexylmethane, 2,4'- and / or 4,4'-diaminodicyclohexylmethane and 1,5-diamino-2-methylpentane.

[0043] The preferred compounds of general formula (IV) used in the above process are maleic acid or fumarate esters of general formula (IV) in which R1 and R2 are the same or different organic groups each having 1 to 18 carbon atoms. Preferably, R1 and R2 are independently linear or branched alkyl groups having 1 to 8 carbon atoms, more preferably each alkyl group such as methyl, ethyl, propyl, isopropyl, butyl, or isobutyl, particularly preferably ethyl.

[0044] Examples of compounds of general formula (IV) include the following: dimethyl maleate, diethyl maleate, di-n-propyl or diisopropyl maleate, di-n-butyl maleate, di-2-ethylhexyl maleate, or the corresponding fumarate ester. Diethyl maleate is particularly preferred.

[0045] The two-component coating composition according to the present invention comprises at least one polyisocyanate component B.

[0046] A suitable polyisocyanate component B is an organic polyisocyanate having at least two average NCO functionalities and a molecular weight of at least 140 g / mol. Particularly suitable are unmodified organic polyisocyanates in the molecular weight range of 140–300 g / mol, paint polyisocyanates in the molecular weight range of 300–1000 g / mol, and NCO prepolymers or mixtures thereof having urethane, urea and / or allophanate groups and a molecular weight greater than 400 g / mol.

[0047] In the context of this invention, the term “paint polyisocyanate” is understood to mean a compound or mixture of compounds that can be obtained from simple polyisocyanates by oligomerization reactions known in themselves. Suitable examples of oligomerization reactions include carbodiimide, dimerization, trimerization, deureation, urea formation, urethaneization, allofanization, and / or cyclization with the formation of an oxadiazine structure. Oligomerization may consist of two or more of the above reactions occurring simultaneously or sequentially.

[0048] "Paint polyisocyanate" is preferably biuret polyisocyanate, polyisocyanate containing isocyanurate groups, a mixture of polyisocyanates containing isocyanurate and uretidione groups, polyisocyanate containing urethane and / or allophanate groups, or a mixture of polyisocyanates containing isocyanurate and allophanate groups based on a simple organic polyisocyanate. Equally suitable as polyisocyanate component B is a prepolymer containing isocyanate groups that is known in itself and is based on a simple organic polyisocyanate and / or paint polyisocyanate, on the one hand, and on the other hand, based on an organic polyhydroxy compound with a molecular weight of more than 300 g / mol. Polyisocyanates in coatings containing urethane groups are derivatives of low molecular weight polyols with a molecular weight range of 62 to 300 g / mol, while suitable polyols are, for example, ethylene glycol, propylene glycol, trimethylolpropane, glycerol, or mixtures thereof. Prepolymers containing isocyanate groups are prepared using polyhydroxy compounds having a molecular weight greater than 300 g / mol, preferably greater than 400 g / mol, and more preferably between 400 and 8000 g / mol. Such polyhydroxy compounds are particularly those having 2 to 6, preferably 2 to 3, hydroxyl groups per molecule and are selected from the group consisting of ethers, esters, thioethers, carbonates, and polyacrylate polyols, as well as mixtures of such polyols.

[0049] In the preparation of prepolymers containing isocyanate groups, the high molecular weight polyols mentioned may also be used in the form of mixtures with the low molecular weight polyols mentioned, directly producing a mixture of a low molecular weight paint polyisocyanate containing urethane groups and a high molecular weight NCO prepolymer which is equally suitable as polyisocyanate component b) according to the present invention.

[0050] For the preparation of prepolymers containing isocyanate groups or mixtures thereof with paint polyisocyanates, simple organic polyisocyanates or paint polyisocyanates of the type mentioned as examples below are reacted with high molecular weight hydroxyl compounds or mixtures thereof and low molecular weight polyhydroxyl compounds of the type mentioned as examples, while maintaining an NCO / OH equivalent ratio of 1.1:1 to 40:1, preferably 2:1 to 25:1, to form urethanes and / or allophanates. If distillable simple organic polyisocyanates are used in excess, this can be optionally removed by distillation after the reaction, resulting in an NCO prepolymer containing monomer-free isocyanate groups, which can also be used as polyisocyanate component b).

[0051] Examples of suitable simple organic polyisocyanates include 1,4-diisocyanate butane, 1,5-diisocyanate pentane, 1,6-diisocyanate hexane (HDI), 1,5-diisocyanate-2,2-dimethylpentane, 2,2,4- and 2,4,4-trimethyl-1,6-diisocyanate hexane, and tetramethylxylylene diisocyanate (TMXDI). 1-Isocyanate-3,3,5-trimethyl-5-isocyanate methylcyclohexane (isophorone diisocyanate, IPDI), 1-Isocyanate-1-methyl-4(3)-isocyanate methylcyclohexane, dicyclohexylmethane 2,4'-diisocyanate and / or 4,4'-diisocyanate, 1,10-diisocyanate todecane, 1,12-diisocyanate todecane, cyclohexane 1,3- and 1,4-diisocyanate, xylylene diisocyanate The isomers, triisocyanate nonanes (TIN), naphthylene 1,5-diisocyanate, 2,4-diisocyanate toluene, or mixtures thereof with 2,6-diisocyanate toluene, preferably an industrial polyisocyanate mixture of 2,2'-,2,4'-,4,4'-diisocyanate diphenylmethane or diphenylmethane series, comprising up to 35% by weight of 2,6-diisocyanate toluene based on the mixture, or any desired mixture of the polyisocyanates mentioned.

[0052] Preferably, 1,4-diisocyanate butane, 1,5-diisocyanate pentane, 1,6-diisocyanate hexane (HDI), 1,5-diisocyanate-2,2-dimethylpentane, 2,2,4- or 2,4,4-trimethyl-1,6-diisocyanate hexane, tetramethylxylylene diisocyanate (TMXDI), 1-isocyanate-3,3,5-trimethyl-5-isocyanate methylcyclohexane (isophorone diisocyanate, IPDI), 1-isocyanate-1-methylcyclohexane The use of aliphatic, alicyclic, or aromatic aliphatic polyisocyanates is selected from the group of polyisocyanates such as tyl-4(3)-isocyanate methylcyclohexane, dicyclohexylmethane 2,4'- and / or 4,4'-diisocyanate, 1,10-diisocyanate todecane, 1,12-diisocyanate todecane, cyclohexane 1,3- and 1,4-diisocyanate, xylylene diisocyanate isomers, triisocyanate nonane (TIN), or any desired mixture of such polyisocyanates.

[0053] In principle, it is also possible to use a mixture of different types of polyisocyanate components as described above.

[0054] In addition to the polyaspartate ester-containing component A, the two-component composition according to the present invention may contain a further component (component C) that is reactive to isocyanate groups.

[0055] These may be, for example, low molecular weight polyols in the molecular weight range of 62 to 300 g / mol, such as ethylene glycol, propylene glycol, trimethylolpropane, glycerol, or mixtures thereof, or polyhydroxy compounds having a molecular weight greater than 300 g / mol, preferably greater than 400 g / mol, and more preferably 400 to 8000 g / mol. Such polyhydroxy compounds are particularly those having 2 to 6 hydroxyl groups per molecule, preferably 2 to 3, and are selected from the group consisting of ethers, esters, thioethers, carbonates, and polyacrylate polyols, as well as mixtures of such polyols.

[0056] In addition, the two-component composition according to the present invention comprises at least one inorganic and / or organic pigment (component D1), such as titanium dioxide, zinc oxide, iron oxide, chromium oxide, or carbon black.

[0057] The proportion of pigment in the composition is preferably 3% by weight or more (≧3% by weight), more preferably 5% to 40% by weight (≧5% to ≦40% by weight), and most preferably 10% to 35% by weight (≧5% to ≦40% by weight), based on the total weight of the two-component composition.

[0058] A comprehensive review of pigments for coatings is found in “Lehrbuch der Lacke und Beschichtungen [Textbook on Paints and Coatings],” Volume II, “Pigments, Fillers, Dyes,” HKittel, Verlag W.AColomb in Heenemann GmbH, Berlin-Oberschwandorf, 1974, pp. 17–265.

[0059] Furthermore, the compositions according to the present invention may also include further auxiliary agents and additives, and in particular polyurethane compounds (component D2), which are typical of coating techniques with polyisocyanate polyaddition compounds:

[0060] Examples include catalysts / activators such as titanium-, zirconium-, bismuth-, tin- and / or iron-containing catalysts, as described in WO 05058996, for example. It is also possible to add amines or amidines. The proportion of the crosslinking catalyst in the composition is preferably 0.001% to 5% by weight (≧0.001% to ≦5%), preferably 0.005% to 2% by weight (≧0.005% to ≦2%), and more preferably 0.01% to 1% by weight (≧0.01% to ≦1%), based on the total weight of the two-component composition.

[0061] Other suitable auxiliary and additive D2 examples include coating additives, e.g., UV absorbers and light stabilizers such as sterically hindered amines (HALS), as well as stabilizers, defoamers, crater inhibitors and / or wetting agents, leveling agents, film-forming aids, reactive diluents, biocides, and solvents or substances for rheological control. The use of light stabilizers, especially UV absorbers, e.g., substituted benzotriazoles, S-phenyltriazines or oxalanilides, and sterically hindered amines, especially those having the 2,2,6,6-tetramethylpiperidyl structure called HALS, is described, for example, in AValet, Lichtschutzmittel fuer Lacke [Light stabilizers for paints], Vincentz Verlag, Hanover, 1996.

[0062] Stabilizers, such as free radical scavengers, and other polymerization inhibitors, such as sterically hindered phenols, are intended to stabilize the paint components during storage and prevent discoloration during curing. Wetting agents and leveling agents improve the surface wetting and / or leveling of the coating. Examples include fluorosurfactants, silicone surfactants, and certain polyacrylates. Rheology-controlling additives are important for controlling the properties of the binary system at application and in the leveling phase on the substrate, and are disclosed, for example, in patent specifications WO9422968, EP0276501, EP0249201, or WO9712945. It is also possible to use water scavengers, such as triethyl orthoformate, toluenesulfonyl isocyanate, monooxazolidine, or molecular sieves, and hydrolysis stabilizers, such as carbodiimides. The proportion of coating additives in the composition is preferably 0.5% to 15% by weight (≧0.5% to ≦15%), preferably 1% to 10% by weight (≧1% to ≦10%), and more preferably 2% to 7% by weight (≧2% to ≦7%), based on the total weight of the two-component composition. A comprehensive review of paint additives can be found in “Lehrbuch der Lacke und Beschichtungen [Textbook on Paints and Coatings],” Volume III, “Loesemittel, Weichmacher, Additive, Zwischenprodukte [Solvents, Plasticizers, Additives, Intermediates],” H. Kittel, Verlag WAColomb in der Heenemann GmbH, Berlin-Oberschwandorf, 1976, pp. 237-398.

[0063] Further auxiliary agents and additives D2 are fillers. Examples of suitable fillers are barite, chalk, or talc. Fillers with a barrier effect can also be used, for example, plate-like phyllosilicate or layered aluminosilicate, graphite, aluminum plates, or barrier pigments, such as iron mica and nanofillers, such as clay and aluminum silicate, where the fillers can be used alone or in combination. The proportion of fillers in the coating is preferably 1% to 30% by weight (≧1% to ≦30%), preferably 3% to 20% by weight (≧3% to ≦20%), and more preferably 5% to 15% by weight (≧5% to ≦15%), based on the total weight of the two-component composition. A comprehensive review of fillers for coatings is found in “Lehrbuch der Lacke und Beschichtungen [Textbook on Paints and Coatings],” Volume II, “Pigments, Fillers, Dyes,” HKittel, Verlag W.AColomb in Heenemann GmbH, Berlin-Oberschwandorf, 1974, pp. 17–265.

[0064] The solvent is also considered an auxiliary and additive D2. The solvent may be an organic solvent, a mixture of organic solvents, or water or a mixture of organic solvents and water. A suitable solvent should be used in a manner known to those skilled in the art, and this use should be tailored to the composition and application process. The solvent is intended to dissolve the components used, facilitate their mixing, and avoid incompatibility. In addition, during coating and curing, they should be removed from the coating in a manner tailored to the ongoing crosslinking reaction so as to give a solvent-free coating with an optimal appearance and free from defects such as popping or pinholes. Suitable solvents include, in particular, solvents used in two-component techniques. Examples of organic solvents are acetone, ketones such as methyl ethyl ketone or hexanone, esters such as ethyl acetate, butyl acetate, and methoxypropyl acetate, substituted glycols and other ethers, aromatic compounds such as xylene or solvent naphtha from Exxon-Chemie, and mixtures of the solvents mentioned. Water is also suitable as a solvent or diluent when the NCO-reactive component of the composition is in the form of an aqueous dispersion. If present, the proportion of solvent in the composition is preferably 0.5% to 40% by weight (≧0.5% to ≦40%), preferably 1% to 30% by weight (≧1% to ≦30%), and more preferably 2% to 25% by weight (≧2% to ≦25%), based on the total weight of the two-component composition.

[0065] The ratio of polyisocyanate component B to polyaspartate ester-containing component A in the composition is preferably 0.5:1.0 to 3.0:1.0, based on the molar amount of polyisocyanate groups relative to NCO-reactive groups. Particularly preferred is a ratio of 0.9:1.0 to 1.5:1.0, and a ratio of 1.05:1.0 to 1.25:1.0 is especially preferred.

[0066] The two-component composition according to the present invention is preferably not a foaming or foam-forming composition. The composition is preferably not radically polymerizable, and in particular not photopolymerizable; that is, the composition does not cure by a radical process, particularly a radical polymerization process initiated by chemical rays.

[0067] The two-component coating composition according to the present invention is manufactured by a method known in paint and coating technology.

[0068] The isocyanate-reactive component (R) and the isocyanate-containing component (H) are initially prepared separately by mixing the respective isocyanate-reactive components A and C, or by mixing the respective polyisocyanate component B. Auxiliaries and additives D1 and D2 are preferably mixed with the isocyanate-reactive component R. Components R and H thus produced are not mixed until immediately before or during application. If mixing is performed before application, it should be noted that the reaction of the components begins immediately after mixing. The reaction rate varies depending on the selection of components and additives. The processing time during which the composition must be applied is also known as the pot life and is defined as the time from mixing of the components to doubling of the initial viscosity and / or flow time (determined according to DIN EN ISO 2431:2012-03, but using a DIN 4 flow cup), which ranges from 1 minute to 24 hours, usually from 10 minutes to 8 hours, depending on the selection of components. The pot life is determined by methods known to those skilled in the art.

[0069] In preferred embodiments, the isocyanate-reactive component is optionally dispersed and subsequently mixed, and then ground. The latter can be carried out, for example, using a bead mill. A sieving step may be performed following the grinding.

[0070] The present invention also relates to a method for coating a substrate, comprising at least the following steps: i) Apply the above two-component coating composition to at least a portion of the substrate to be coated, and ii) The coating composition from step i) is cured.

[0071] Accordingly, the present invention further provides the use of the two-component coating composition according to the present invention in the manufacture of a coating on a substrate, the above method for coating a substrate, and the coated substrate itself obtained in this manner.

[0072] The substrate may already be fully or partially coated with one or more coating layers. These coating layers may be uncured or wet, partially cured or fully cured, and any further coating layers on the substrate are preferably partially or fully cured. Examples of coating layers include primer coats, undercoats, fillers, sprinkling coats, base coats, or substrates that are already fully painted and recoated after possible pretreatment such as sanding or plasma activation.

[0073] Two-component coating compositions are used particularly in the manufacture of anticorrosive coatings, general industrial painting, and in the fields of ACE (agricultural, building, and civil engineering). The coatings here are preferably topcoats.

[0074] Accordingly, the present invention preferably provides the use of the above two-component coating composition in the production of a topcoat on a substrate, the above method for coating a substrate with these topcoats, and the coated substrate itself that can be obtained in this manner.

[0075] Furthermore, the present invention provides for the use of topcoats in the fields of corrosion protection, general industrial coatings, or ACE coatings.

[0076] The coating composition can be applied by conventional application methods. Examples of application methods include application with a coarse or fine brush, roller application, knife application, dipping, and spraying, with spray application being preferred. After an optional flash-off time, curing or drying of the composition according to the present invention is performed on the substrate or object following the application. This is carried out according to conventional methods in coating technology, either under ambient conditions (temperature and atmospheric humidity) or under forced conditions, such as increasing the oven temperature, using radiation such as infrared, near-infrared, or microwave radiation, and using dehumidified and / or heated air or other gases. This is preferably done without the use of equipment for forced curing. The applied coating composition is cured at a temperature of, for example, -20 to 100°C, preferably -10 to 80°C, more preferably 0 to 60°C, and most preferably 10 to 40°C. Lower curing temperatures may be used, though less preferred, but this results in a longer curing time.

[0077] Similarly, although undesirable, it is also possible to cure the composition at higher temperatures, for example, 80-160°C or above.

[0078] After the first coating has cured, a further coating may be applied and cured in the same manner.

[0079] The present invention further provides the use of a two-component coating composition in the manufacture of gloss-stable coatings. [Examples]

[0080] Examples of Experiments Raw materials and base materials: PACM20: Mixture of 2,4- and 4,4'-diaminodicyclohexylmethane, Manufacturer: Evonik Desmodur N 3600: Low viscosity HDI trimer containing approximately 23% NCO and ≤0.25% free HDI, Manufacturer: Covestro Desmodur XP 2489: An aliphatic polyisocyanate based on HDI and isophorone diisocyanate trimers, containing approximately 21% NCO, manufactured by Covestro UOP L Powder: Molecular Sieves, Honeywell UOP, USA Byk A 530: Antifoaming agent, Byk-Chemie GmbH, Germany Disperbyk 163: Dispersant, Byk-Chemie GmbH, Germany Titanium dioxide R-KB-4: Pigment, various suppliers Chromium Oxide Green GN: Pigment, various suppliers Iron Oxide Yellow 415: Pigment, various suppliers Heucophos® ZPA: Corrosive protective pigment, Heubach GmbH, Germany Baryte EWO: Barite filler, Sachtleben, Germany Microtalc IT Extra: Talc filler, Mondo Minerals, Netherlands CAB-O-SIL TS 720: Rheological additive, Cabot Aerogel, Germany Tinuvin 292: Light stabilizer, BASF, Germany Solvent: Solvesso 100, 1-methoxy-2-propyl acetate (MPA) and butyl acetate (BA), Azelis, Germany

[0081] method: The diethyl fumarate content was quantified using GC with an internal standard. An Agilent 6890 gas chromatograph with a standard GC capillary (100% polysiloxane phase) and an FID detector was used. The injector temperature (split outlet) was 180°C, and helium was used as the carrier gas. The limit of quantification for this method was 300 ppm.

[0082] GC-MS analysis was performed using an Agilent 6890 gas chromatograph and an Agilent 5973 mass spectral detector, employing standard ionization (electron bombardment) at 70 eV, a standard GC capillary (100% polysiloxane phase), and divided injection at an injector temperature of 250°C. Gas chromatogram evaluation was performed as area percentage.

[0083] All viscosity measurements were performed at 23°C using a Physica MCR 51 rheometer from Anton Paar Germany GmbH (DE), in accordance with DIN EN ISO 3219:1994-10.

[0084] The Hazen color index values ​​were measured using a Lico 400 colorimeter from Hach Lange GmbH (Germany) in accordance with DIN EN ISO 6271:2016-05.

[0085] The amine value was determined titrately according to EN ISO 9702:1998 (perchloric acid method), except that the result was expressed as an amine value. The amine value in mg KOH / g was calculated according to the following formula:

number

[0086] The flow time was determined according to DIN EN ISO 2431:2012-03, except that a DIN 4 flow cup was used.

[0087] Pot life was defined as the time required for the viscosity to double.

[0088] Drying was measured according to DIN EN ISO 9117-5:2012-11.

[0089] Weather resistance was tested according to DIN EN ISO16474 / 2:2014-03, Method A, Cycle 1 (102:18) and DIN EN ISO16474 / 3:2014-03, Method C, Cycle 4 (UVB). Tests were performed on a single-layer topcoat on roughened aluminum.

[0090] The gloss value was measured using a reflectometer in accordance with the standard DIN EN ISO2813:2015-02.

[0091] Pendulum hardness was determined using a Koenig pendulum on glass, in accordance with DIN EN ISO1522:2007-04.

[0092] Spray coating was performed using a SATAjet RP 3000 spray gun with a 1.6 mm SATA spray nozzle at a pressure of approximately 2.1–2.2 bar. Coating was performed under typical ambient conditions (allowing for slight variations in temperature and humidity).

[0093] Salt spray testing was performed on samples described in accordance with ISO 17872, following DIN EN ISO 9227:2012-09, which corresponds to the NSS method. Single and double topcoats were applied to steel plates (blasted with SA21 / 2). Blistering was evaluated according to DIN EN ISO 4628-2:2016-07 (nc = no change / bl = number of blisters / bs = blister size). Delamination and corrosion were evaluated according to ISO 4628-8:2012-3.

[0094] The condensate test was performed according to DIN EN ISO6270-2:2005-09. Blistering was evaluated according to DIN EN ISO4628-2:2016-07 (nc = no change / bl = number of blisters / bs = blister size).

[0095] The cross-cut test was performed in accordance with DIN EN ISO2409:2006-13.

[0096] The pull-off test was performed according to DIN EN ISO 4624:2016-08 Method B. The tensile stress and fracture properties were evaluated according to the following criteria: A. Poor adhesion of the substrate; Poor adhesion between the A / B substrate and the first coating; B. Poor adhesion in the first coating; B / C Poor adhesion between the first coating and the second coating;

[0097] Manufacturing of pigmentation topcoats The topcoat was prepared at room temperature by placing the components of Component 1 in a cooling container (a jacketed container externally cooled with cold tap water), pre-dispersing them using a dissolver at approximately 600-800 rpm, then grinding them in a bead mill, and finally sieving them. Component 1 was processed after a maturation period of one day.

[0098] Next, component 2 was added slowly while stirring (approximately 600-800 rpm), and then dispersed at 2000 rpm for 1 minute (coating 1) or at 2800 rpm for 30 minutes (coating 2).

[0099] Single-layer structure The topcoat used was applied to steel plates (blasted SA21 / 2) or roughened aluminum plates by the described spray application method and dried at 23°C / 50% relative humidity.

[0100] double layer structure A 1C PUR zinc dust basecoat was applied to a steel plate (blasted to SA21 / 2) by the spray application method described in the Covestro Deutschland AG guideline formulation designated RR5280. After this basecoat had dried, the topcoat was similarly applied by the spray application method described and dried at 23°C / 50% relative humidity.

[0101] Polyaspartate ester PAE1 A polyaspartate ester marketed by Covestro under the name Desmophen NH 1420. Material data: Monoamine of formula (II) (GC-MS): 4.0% Diethyl fumarate (GC) 2.9% by weight Viscosity 1220 mPas Color Index 27APHA Amine value: 201 mg KOH / g

[0102] Polyaspartate ester PAE2 First, 341.8 g of PACM20 was packed under stirring and dry nitrogen at 23°C. 560.0 g of diethyl maleate was added dropwise, ensuring the temperature did not rise above 60°C. At the end of the addition, the temperature was adjusted to 45°C, and the mixture was stirred at 45°C for 2 hours. Next, the mixture was stored at 23°C for 7 weeks. The diethyl fumarate content after storage was 3.0% by weight. Next, the diethyl fumarate was removed by distillation at 120°C and 0.2 mbar. A light-colored product with the following material data was obtained: Monoamine of formula (II) (GC-MS): 4.2% Diethyl fumarate (GC) 0.05% by weight Viscosity 1860mPas Color Index 19 APHA Amine value: 203 mg KOH / g

[0103] Polyaspartate ester PAE3 First, 341.8 g of PACM20 was packed under stirring and dry nitrogen at 23°C. 560.0 g of diethyl maleate was added dropwise, ensuring the temperature did not rise above 60°C. At the end of the addition, the temperature was adjusted to 45°C, and the mixture was stirred at 45°C for 2 hours. Next, the mixture was stored at 23°C for 9 weeks. The diethyl fumarate content after storage was 2.7% by weight. Next, the diethyl fumarate was removed by distillation at 120°C and 0.2 mbar. A light-colored product with the following material data was obtained: Monoamine of formula (II) (GC-MS): 5.3% Diethyl fumarate (GC) 0.09% by weight Viscosity 1810 mPas Color Index 27APHA Amine value: 206 mg KOH / g

[0104] Polyaspartate ester PAE4 First, 341.8 g of PACM20 was packed under stirring and dry nitrogen at 23°C. 567.6 g of diethyl maleate was added dropwise, ensuring the temperature did not rise above 60°C. Upon completion of the addition, the temperature was adjusted to 45°C, and the mixture was stirred at 45°C for 2 hours. The mixture was then stored at 23°C for 30 hours. The diethyl fumarate content after storage was 8.62% by weight. Next, the diethyl fumarate was removed by distillation at 120°C and 0.2 mbar. A light-colored product with the following material data was obtained: Monoamine of formula (II) (GC-MS): 13.2% Diethyl fumarate (component A, GC) <0.03% by weight Viscosity 1650 mPas Color Index 5APHA Amine value: 213 mg KOH / g

[0105] Polyaspartate ester PAE5 First, 341.8 g of PACM20 was packed under stirring and dry nitrogen at 23°C. 1678.8 g of diethyl maleate was added dropwise, ensuring the temperature did not rise above 60°C. Upon completion of the addition, the temperature was adjusted to 45°C, and the mixture was stirred at 45°C for 1 hour. The mixture was then stored at 23°C for 24 hours. Next, the diethyl fumarate was removed by distillation at 120°C and 0.2 mbar. A light-colored product with the following material data was obtained: Monoamine of formula (II) (GC-MS): 9.3% Diethyl fumarate (component A, GC) 0.07% by weight Viscosity 1710 mPas Color Index 21APHA Amine value: 219 mg KOH / g

[0106] As shown in Tables 1 and 7, polyaspartate esters PAE1, 2, 3, and PAE5 were incorporated into the top coat.

[0107] [Table 1]

[0108] Tables 2 and 3 summarize the pot life and drying time of the topcoats in Examples 1-8.

[0109] [Table 2]

[0110] [Table 3]

[0111] As can be seen from Table 2, the coating compositions according to the present invention exhibit faster drying, associated with a longer pot life, compared to conventional polyaspartate ester-based coating compositions. The coating compositions according to the present invention shown in Table 3 similarly have a longer pot life along with the same rapid drying.

[0112] The cured topcoats from Examples 4, 5, 7, and 8 were also subjected to weather resistance testing. The results are shown in Tables 4-6.

[0113] [Table 4]

[0114] [Table 5]

[0115] [Table 6]

[0116] As the weather resistance results show, the coating composition according to the present invention exhibits slower gloss loss and higher or at least equally higher residual gloss compared to conventional polyaspartate ester-based coating compositions.

[0117] [Table 7]

[0118] [Table 8]

[0119] Table 8 confirms that the coating composition according to the present invention is characterized not only by good chemical resistance but also by faster drying, which is associated with a longer pot life, compared to conventional polyaspartate ester-based coating compositions.

[0120] Next, the cured coatings 9-14 were subjected to both a condensed water test and a salt spray test.

[0121] [Table 9]

[0122] [Table 10]

[0123] These results demonstrate that the coating composition according to the present invention contributes to obtaining corrosion-resistant formulations.

[0124] Next, the cured coatings 9-14 were applied to provide weather resistance.

[0125] [Table 11]

[0126] [Table 12]

[0127] The topcoat 2 based on the coating composition according to the present invention is characterized by slower gloss loss and higher, or at least equally higher, residual gloss compared to a conventional topcoat 2 based on polyaspartate esters.

Claims

1. A process for producing a two-component coating composition (2C coating composition) comprising the following, a) At least one polyaspartate ester-containing component A, b) at least one polyisocyanate component B, c) Optionally, one or more components C that are reactive to isocyanate groups, unlike A. d) at least one inorganic and / or organic pigment, and which may contain other auxiliary agents and additives (component D2), Here, component A corresponds to a composition containing the following: One or more polyaspartate esters of general formula (I) 【Chemistry 1】 [In the formula, X is an m-valent organic group, optionally containing one or more heteroatoms, having an amino group bonded (cyclo)aliphatic or aromaticaliphatic, obtainable by removing a primary amino group from a corresponding polyamine, and having a molecular weight in the range of 60 to 6000 g / mol.] Furthermore, it may contain additional functional groups that are reactive with respect to the isocyanate group and / or inert at temperatures up to 100°C. R1 and R2 are identical or different organic groups, each having 1 to 18 carbon atoms. m is an integer greater than 1, and One or more polyaspartic acid esters having a primary amino group of general formula (II) 【Chemistry 2】 [In the formula, n is m-1, and X and R １ and R ２ The base is the same as above. and, The dialkyl fumarate is present in component A in an amount of 0.01% to 1.2% by weight based on the total weight of component A. Furthermore, the proportion of the compound of formula (II) is 4% or more and 20% or less based on the area determined by GC (measured as area %) of the gas chromatogram, and here, the sum of the areas of the two compounds of general formulas (I) and (II) determined by GC is 100%. Here, the amount of dialkyl fumarate is reduced by distillation. The aforementioned process.

2. The process according to claim 1, characterized in that dialkyl fumarate is present in component A in an amount of 0.01% to 1% by weight based on the total weight of component A.

3. The process according to claim 1, characterized in that dialkyl fumarate is present in component A in an amount of 0.01% to 0.1% by weight based on the total weight of component A.

4. The process according to any one of claims 1 to 3, wherein the proportion of the compound of formula (II) is 15% or less of the area covered by GC.

5. A method for manufacturing a coating on a substrate, including the following steps: i) Apply a two-component coating composition obtained by the process described in any one of claims 1 to 4 to at least a portion of the substrate to be coated, and ii) The coating composition from step i) is cured.

6. A substrate having a coating thereon, wherein the coating comprises a cured two-component coating composition as defined in any one of claims 1 to 4.

7. A method for manufacturing a coating on a substrate according to claim 5, characterized in that the coating is a top coat.

8. The substrate according to claim 6, characterized in that the coating is a top coat.

9. Use of a two-component coating composition (2C coating composition) obtained by a process according to any one of claims 1 to 4 for manufacturing a coating, Herein, the use is such that the coating is used in the field of corrosion protection or general industrial coating, or as a coating for ACE (agricultural, construction and earthwork equipment).

10. The method according to claim 5 or 7, wherein the coating is used in the field of corrosion protection or general industrial coating, or as a coating for ACE (agricultural, construction and earthworks).

11. The substrate according to claim 6 or 8, wherein the coating is used in the field of corrosion protection or general industrial coating, or as a coating for ACE (agricultural, construction and earthworks).

12. Use of a two-component coating composition (2C coating composition) obtained by the process described in any one of claims 1 to 4 for manufacturing a gloss-stable coating.

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