Triazine carbamate crosslinking agent

Abstract

One or more compounds of general formula (II) [Formula 1] JPEG2025520070000025.jpg2234 with one or more compounds of general formula (III) HO-[X-] i R 1 (III) A crosslinking agent obtainable by reacting Compounds of formula (I) [Case 2] JPEG2025520070000026.jpg2132 (Wherein, Q' is a group represented by the formula COO-[X-] i R 1 Based on each i is independently selected from an integer from 1 to 50 for 35 mol % or more of Q' in the mixture, and i is equal to 0 for the remaining Q' in the mixture; each X is independently selected from the group consisting of CH2-CH2-O, CH2-CH(CH3)-O, CH(CH3)-CH2-O-, CH2-C(CH3)2-O-, CH2-CHVin-O, CHVin-CH2-O, CH2-CHPh-O-, and CHPh-CH2-O, where Ph is phenyl and Vin is vinyl; Each R 1 is C1~C 30 hydrocarbyl) A crosslinking agent comprising a mixture of

Description

Technical Field

[0001] The present invention relates to triazine carbamate crosslinking agents, particularly for use in coating compositions, and more particularly for use in aqueous formulations for forming coatings.

Background Art

[0002] Tris(alkoxycarbonylamino)triazines are commercially available crosslinking agents. These typically contain combinations of various alkyl carbamate functional groups in their chemical structures. Since these are typically not water-soluble, they are supplied in organic solvents such as n-butanol. Therefore, it is difficult to use them in aqueous coating formulations. An interesting feature of such compounds is that they do not contain formaldehyde and do not release it upon curing. Therefore, their human toxicity is lower. They are also not particularly suitable for self-crosslinking reactions, i.e., they do not form films in the absence of other reactive compounds. When used to crosslink reactive compounds such as hydroxy-containing polymers and epoxy-containing polymers, they give very durable acid-resistant films that exhibit a good balance of hardness and flexibility. Such films typically find use in automotive topcoats, exterior can varnishes, and coil coatings. Tris(alkoxycarbonylamino)triazines can be used as the sole crosslinking agent in coating or ink formulations, or at lower levels in combination with other crosslinking agents such as amino resins or isocyanates to obtain a balance of properties.

[0003] In addition to tris(alkoxycarbonylamino)triazines, several other available non-formaldehyde crosslinking agents that provide carbamate functional groups are available. Examples of such alternatives are isocyanates and blocked isocyanates. Although these can provide excellent properties, there is a risk of generating harmful blocking agents and free isocyanates.

Summary of the Invention

[0004] Accordingly, an object of the present invention is to provide a carbamate crosslinking agent that overcomes at least some of the above drawbacks.

[0005] More specifically, an object of the present invention is to provide a stable water-compatible carbamate crosslinking agent that enables a high crosslinking density and has few associated environmental and toxicity problems.

[0006] The crosslinking agent of the first aspect, the mixture of the second aspect, and the compound of the third aspect may have one or more of the following advantages: · It may be self-crosslinkable. This means that they can react with themselves to form a crosslinked product (typically a film). Thus, no additional reactive compound other than the crosslinking agent, mixture, or compound itself is required to obtain the crosslinked product. Thus, typically, a film can be obtained in the presence of only a small amount of additional reactive compound or even in its absence. · It may be formaldehyde-free. This means that they do not need to contain formaldehyde and typically do not contain formaldehyde. Also, they do not release formaldehyde upon curing. Thus, their human toxicity is low. · It tends to be dispersible in water and is thus particularly well-suited for forming low-VOC (volatile organic compound) formulations. · It may enable the formation of coatings having a high crosslinking density. · It may be compatible with aqueous acrylic, polyester, and epoxy binders.

[0007] The aqueous dispersion of the fourth aspect may have one or more of the following advantages: · It may be stable. · The VOC can be very low. · It may enable the formation of coatings having excellent solvent resistance on a plurality of substrates including metals, glass, and paper.

[0008] In a first aspect, the present invention provides a compound of one or more general formulas (II) [Chemical formula] (wherein each Q'' is a group of the formula COOR 2 and each R 2 is independently selected from the group consisting of C1-C 30 hydrocarbyl) with one or more compounds of general formula (III) HO-[X-] i R 1 (III) (wherein each X is independently selected from the group consisting of CH2-CH2-O, CH2-CH(CH3)-O, CH(CH3)-CH2-O-, CH2-C(CH3)2-O-, CH2-CHVin-O, CHVin-CH2-O, CH2-CHPh-O-, and CHPh-CH2-O (wherein Ph is phenyl and Vin is vinyl), each i is independently selected from integers from 1 to 50, each R 1 is independently selected from the group consisting of C1-C 30 hydrocarbyl) to obtain a crosslinking agent that can be obtained by reacting, a compound of general formula (I) [Chemical formula] (wherein Q' is a group of the formula COO-[X-] i R 1 and each i is independently selected from integers from 1 to 50 for 35 mol% or more of Q' in the mixture, and i is equal to 0 for the remaining Q' in the mixture, Each X is independently selected from the group consisting of CH2-CH2-O, CH2-CH(CH3)-O, CH(CH3)-CH2-O-, CH2-C(CH3)2-O-, CH2-CHVin-O, CHVin-CH2-O, CH2-CHPh-O-, and CHPh-CH2-O (wherein Ph is phenyl and Vin is vinyl). Each R 1 is independently selected from the group consisting of C1-C 30 hydrocarbyl). relates to a crosslinking agent comprising a mixture of)

[0009] In a second aspect, the present invention relates to a compound of general formula (I) [Chemical formula] (wherein Q' is a group of the formula COO-[X-] i R 1 and each i is independently selected from integers from 1 to 50 for 35 mol% or more of Q' in the mixture, and i is equal to 0 for the remaining Q' in the mixture. Each X is independently selected from the group consisting of CH2-CH2-O, CH2-CH(CH3)-O, CH(CH3)-CH2-O-, CH2-C(CH3)2-O-, CH2-CHVin-O, CHVin-CH2-O, CH2-CHPh-O-, and CHPh-CH2-O (wherein Ph is phenyl and Vin is vinyl). Each R 1 is independently selected from the group consisting of C1-C 30 hydrocarbyl). relates to a mixture of).

[0010] In a third aspect, the present invention provides a compound of general formula (I) selected from the list consisting of: a) a compound in which one of the Q' groups is a group of the formula COOCH2CH2CH2CH3 and two of the Q' groups are groups of the formula COO-[CH2-CH2-O-]2CH3; b) a compound in which one of the Q' groups is a group of the formula COOCH2CH2CH2CH3 and two of the Q' groups are groups of the formula COO-[CH2-CH2-O-]2CH2CH2CH2CH3; c) a compound in which one of the Q' groups is a group of the formula COOCH2CH2CH2CH3 and two of the Q' groups are groups of the formula COO-[CH2-CH(CH3)-O-]2CH3; d) a compound in which one of the Q' groups is a group of the formula COOCH2CH2CH2CH3 and two of the Q' groups are groups of the formula COOCH2CH2OCH2CH2CH2CH3; and e) a compound in which one of the Q' groups is a group of the formula COOCH2CH2CH2CH3 and two of the Q' groups are groups of the formula COO-[CH2-CH2-O-]2CH2CH3. [Chemical formula] relates to.

[0011] In a fourth aspect, the present invention relates to an aqueous (coating) composition comprising one of a crosslinking agent according to any embodiment of the first aspect, a mixture according to any embodiment of the second aspect, or a compound according to any embodiment of the third aspect.

[0012] In a fifth aspect, the present invention provides, in the absence of a catalyst, one or more compounds of general formula (II) [Chemical formula] (wherein Q'' is a group of the formula COOR 2 and each R 2 is independently selected from the group consisting of C1-C 30 hydrocarbyl) reacted with one or more compounds of general formula (III) HO-[X-] i R 1 (III) (wherein each X is independently selected from the group consisting of CH2-CH2-O, CH2-CH(CH3)-O, CH(CH3)-CH2-O-, CH2-C(CH3)2-O-, CH2-CHVin-O, CHVin-CH2-O, CH2-CHPh-O-, and CHPh-CH2-O (wherein Ph is phenyl and Vin is vinyl)), each i is independently selected from integers from 1 to 50, each R 1 is independently selected from the group consisting of C1-C 30 hydrocarbyl) A method for forming a crosslinking agent according to the first aspect, a mixture according to the second aspect, or a compound according to the third aspect, comprising reacting with

[0013] In a sixth aspect, the present invention is a method for forming a coating, comprising reacting a crosslinking agent according to any embodiment of the first aspect, a mixture according to any embodiment of the second aspect, or a compound according to any embodiment of the third aspect with itself, provided that the reaction is carried out in the presence of a further compound, other than a compound containing a 1,3,5-triazine carbamate moiety, which can condense with the compound of general formula (I) and is present in a maximum amount of 30% by weight relative to the amount of the compound of general formula (I).

[0014] In a seventh aspect, the present invention relates to a coating comprising a crosslinked crosslinking agent according to any embodiment of the first aspect, a crosslinked mixture according to any embodiment of the second aspect, or a crosslinked compound according to any embodiment of the third aspect, provided that no further compound other than a compound containing a 1,3,5-triazine carbamate moiety has condensed with the compound of general formula (I), or a maximum of 30% by weight of the compound of general formula (I) of a further compound other than a compound containing a 1,3,5-triazine carbamate moiety has condensed with the compound of general formula (I).

[0015] In an eighth aspect, the present invention relates to a method of co-crosslinking a crosslinking agent according to any embodiment of the first aspect, a mixture according to any embodiment of the second aspect, or a compound according to any embodiment of the third aspect with a further compound, the method comprising heating the mixture and the further compound at a temperature of 100 to 150 °C.

Mode for Carrying Out the Invention

[0016] As used herein, unless otherwise provided, the term "aqueous composition" is meant to refer to an aqueous solution, an aqueous dispersion, and an aqueous emulsion. As is typically known in the art, the term "aqueous solution" is meant to refer to a compound, typically oligomers and / or polymer particles, that is mixed with an aqueous medium in a continuous phase. The term "aqueous dispersion" is meant to refer to a mixture in which the compound is dispersed as insoluble particles in an aqueous medium. The term "aqueous emulsion" is meant to refer to a mixture in which the compound is suspended as droplets throughout an aqueous medium.

[0017] In a first aspect, the present invention provides one or more compounds of general formula (II)

Chemical formula

Chemical formula

[0018] The crosslinking agent according to the present invention can be obtained by a carbamoyl group transfer reaction in which the group of formula [X-] i R 1 replaces the hydrocarbyl chain R of formula (II) to give formula (I). Compound (II) for use herein can be a pure compound or a mixture of compounds corresponding to general formula (II). Compounds of general formula (II) are most readily available as mixtures of compounds corresponding to general formula (II), and such mixtures of compounds are acceptable starting materials for preparing the crosslinking agent, mixture, or compound according to the present invention. 2

[0019] Formula (II) is in its extended form: ​ [Chemical formula] It can also be represented by. The compound of general formula (II) is also sometimes called tris(alkoxycarbonylamino)triazine (TACT).

[0020] R 2 is independently selected from the group consisting of C1-C 30 hydrocarbyl, preferably C1-C 15 hydrocarbyl, more preferably C1-C 12 hydrocarbyl, even more preferably the group consisting of C1-C8 hydrocarbyl, still more preferably the group consisting of C1-C6 hydrocarbyl, even still more preferably the group consisting of C1-C4 hydrocarbyl, and even still more preferably the group consisting of C1 hydrocarbyl and C4 (e.g., n-butyl) hydrocarbyl. A straight-chain hydrocarbyl chain is preferred for R 2 . The advantage of the crosslinking agent according to the first aspect obtained from compound (II) in which R 2 is a relatively short hydrocarbyl chain is expected to be more water-compatible than the crosslinking agent according to the first aspect obtained from compound (II) in which R 2 is a relatively long hydrocarbyl chain. Nevertheless, even with a longer R 2 chain, the water compatibility is improved with respect to the starting material.

[0021] Examples of one or more compounds of general formula (II) are compounds in which all R 2 groups are methyl, compounds in which all R 2 groups are n-butyl, and mixtures of compounds of general formula (II) including compounds in which some R 2 groups are methyl and other R 2 groups are n-butyl. A specific example of such a mixture is CYMEL® NF 2000 commercially available from allnex USA, Inc.

[0022] [X-] present in compound (I)i R 1 It has been observed that the exact nature of the radical can be varied within defined limits while maintaining its advantageous properties. Thus, it is permissible to use two or more different compounds (III) to prepare compound (I). However, it is simpler to use a single compound (I).

[0023] The various possible X share hydrophilic properties and length.

[0024] In embodiments, each X can be independently selected from the group consisting of -CH2-CH2-O and -CH2-CH(CH3)-O.

[0025] The nature and proportion of X in the case of a mixture are typically the same for a mixture of compounds (I) contained in one or more compounds of general formula (III) and the crosslinking agent.

[0026] The nature and proportion of i in the case of a mixture are typically the same for a mixture of compounds (I) contained in one or more compounds of general formula (III) and the crosslinking agent, provided that i is different from 0.

[0027] In embodiments, each i different from 0 can be independently selected from integers from 1 to 50, preferably from 1 to 30, more preferably from 1 to 15, still more preferably from 1 to 10, even more preferably from 1 to 5, and yet even more preferably from 2 to 3, and most preferably, each i different from 0 is 2.

[0028] R in the case of a mixture 1 The nature and proportion thereof are typically the same for a mixture of compounds (I) contained in one or more compounds of general formula (III) and the crosslinking agent, provided that i is different from 0.

[0029] R in the case of a mixture 1The property and its ratio are typically the same as those of R for the mixture of one or more compounds of general formula (III) and compound (II) contained in the crosslinking agent, as long as i is equal to 0. 2 It is the same as the property and its ratio of

[0030] R 1 is independently selected from the group consisting of C1-C 30 hydrocarbyl. In an embodiment, R 1 can be a linear or branched alkyl, with or without a cyclic moiety, aryl, alkylaryl, or arylalkyl. Linear alkyl is preferred.

[0031] In an embodiment, R 1 is independently selected from the group consisting of C1-C 20 hydrocarbyl, preferably C1-C 10 hydrocarbyl, more preferably C1-C6 hydrocarbyl, and most preferably C1-C4 hydrocarbyl. Shorter hydrocarbyls are preferred from the perspective of their better water compatibility.

[0032] Examples of one or more compounds of general formula (III) are 2-(2-methoxyethoxy)ethanol, 2-(2-butoxyethoxy)ethanol, dipropylene glycol monomethyl ether, and 2-butoxyethanol.

[0033] Typically, the crosslinking agent of the present invention does not contain formaldehyde.

[0034] Typically, the mixture of compounds contained in the crosslinking agent also does not contain formaldehyde.

[0035] The mixture of crosslinking agent and the compounds contained therein according to the first aspect includes compounds that can be obtained by reacting one or more compounds of general formula (II) with one or more compounds of general formula (III), but may also include unreacted starting materials (for example, compounds of general formula (I) having i such that each Q' is equal to 0) that may remain in the reaction medium at the end of the reaction. In embodiments, at least 70 mol%, preferably at least 80 mol%, more preferably at least 90 mol%, even more preferably at least 95 mol%, more preferably substantially all of the compounds of the crosslinking agent may be according to general formula (I). The crosslinking agent may be in a liquid medium, i.e., in contact with a solvent. For example, the crosslinking agent can be suspended, dispersed, or dissolved in a solvent. The solvent preferably contains water, and the crosslinking agent is then contained in an aqueous dispersion. This is the subject of the fourth aspect.

[0036] In embodiments, at least 70 mol%, preferably at least 80 mol%, more preferably at least 90 mol%, more preferably at least 95 mol%, even more preferably at least 99 mol%, most preferably substantially all of the compounds of the mixture of compounds of general formula (I) may have at least one Q' group having an i different from 0. In other words, in these embodiments, at most 30 mol%, preferably at most 20 mol%, more preferably at most 10 mol%, more preferably at most 5 mol%, even more preferably at most 1 mol% of the compounds of the mixture of compounds of general formula (I) have all Q' groups equal to 0, and most preferably substantially none have Q' groups equal to 0. These compounds of general formula (I) having all Q' groups equal to 0 are typically unreacted compounds of general formula (II).

[0037] In embodiments, each X can be independently selected from the group consisting of -CH2-CH2-O and -CH2-CH(CH3)-O.

[0038] In an embodiment, for each i, for 35 mol% or more of Q' in the mixture, it can be independently selected from integers of 1 to 50, preferably 1 to 30, more preferably 1 to 15, still more preferably 1 to 10, even more preferably 1 to 5, and yet even more preferably 2 to 3, and i is equal to 0 for the remaining Q' in the mixture.

[0039] In a preferred embodiment, for each i, for 50 to 80 mol% of Q' in the mixture, it can be independently selected from integers of 1 to 50, preferably 1 to 30, more preferably 1 to 15, still more preferably 1 to 10, even more preferably 1 to 5, and yet even more preferably 2 to 3, and i is equal to 0 for the remaining Q' in the mixture.

[0040] In a more preferred embodiment, for each i, for 57 to 77 mol% of Q' in the mixture, it can be independently selected from integers of 1 to 50, preferably 1 to 30, more preferably 1 to 15, still more preferably 1 to 10, even more preferably 1 to 5, and yet even more preferably 2 to 3, and i is equal to 0 for the remaining Q' in the mixture.

[0041] In an even more preferred embodiment, for each i, for 59 to 77 mol% of Q' in the mixture, it can be independently selected from integers of 1 to 50, preferably 1 to 30, more preferably 1 to 15, still more preferably 1 to 10, even more preferably 1 to 5, and yet even more preferably 2 to 3, and i is equal to 0 for the remaining Q' in the mixture.

[0042] In a still more preferred embodiment, i can be equal to 1 or 2 for 59 to 77 mol% of Q' in the mixture, and i is equal to 0 for the remaining Q' in the mixture.

[0043] In the most preferred embodiment, i can be equal to 2 for 59 to 77 mol% of Q' in the mixture, and i is equal to 0 for the remaining Q' in the mixture.

[0044] In an embodiment, at least 5 mol%, preferably at least 10 mol%, more preferably at least 15 mol%, still more preferably at least 20 mol% of the compound of formula (I) in the mixture has, for all three of its Q' groups, an i that is different from 0 and is selected from integers from 1 to 50.

[0045] In an embodiment, 5 mol% to 40 mol%, preferably 10 to 32 mol%, more preferably 16 to 26 mol%, still more preferably 19 to 23 mol%, most preferably 20 to 22 mol% of the compound of formula (I) in the mixture has, for all three of its Q' groups, an i that is different from 0 and is selected from integers from 1 to 50.

[0046] In an embodiment, 5 mol% to 40 mol%, preferably 10 to 32 mol%, more preferably 16 to 26 mol%, still more preferably 19 to 23 mol%, most preferably 20 to 22 mol% of the compound of formula (I) in the mixture has, for all three of its Q' groups, an i that is selected from integers from 1 to 30.

[0047] In an embodiment, 5 mol% to 40 mol%, preferably 10 to 32 mol%, more preferably 16 to 26 mol%, still more preferably 19 to 23 mol%, most preferably 20 to 22 mol% of the compound of formula (I) in the mixture has, for all three of its Q' groups, an i that is selected from integers from 1 to 15.

[0048] In an embodiment, 5 mol% to 40 mol%, preferably 10 to 32 mol%, more preferably 16 to 26 mol%, still more preferably 19 to 23 mol%, most preferably 20 to 22 mol% of the compound of formula (I) in the mixture has, for all three of its Q' groups, an i that is selected from integers from 1 to 10.

[0049] In an embodiment, 5 mol% to 40 mol%, preferably 10 to 32 mol%, more preferably 16 to 26 mol%, even more preferably 19 to 23 mol%, and most preferably 20 to 22 mol% of the compound of formula (I) in the mixture has an i selected from the integers 1 to 5 for all three of its Q' groups.

[0050] In an embodiment, 5 mol% to 40 mol%, preferably 10 to 32 mol%, more preferably 16 to 26 mol%, even more preferably 19 to 23 mol%, and most preferably 20 to 22 mol% of the compound of formula (I) in the mixture has an i selected from the integers 2 to 3 for all three of its Q' groups.

[0051] In an embodiment, 5 mol% to 40 mol%, preferably 10 to 32 mol%, more preferably 16 to 26 mol%, even more preferably 19 to 23 mol%, and most preferably 20 to 22 mol% of the compound of formula (I) in the mixture has an i equal to 2 for all three of its Q' groups.

[0052] Any feature of the first aspect can be as described correspondingly in the fifth aspect.

[0053] In a second aspect, the present invention relates to a compound of general formula (I) [Chemical formula] (wherein Q' is a group of the formula COO-[X-] i R 1 and each i is independently selected from the integers 1 to 50 for 35 mol% or more of the Q' in the mixture, and i is equal to 0 for the remaining Q' in the mixture, each X is independently selected from the group consisting of CH2-CH2-O, CH2-CH(CH3)-O, CH(CH3)-CH2-O-, CH2-C(CH3)2-O-, CH2-CHVin-O, CHVin-CH2-O, CH2-CHPh-O-, and CHPh-CH2-O (wherein Ph is phenyl and Vin is vinyl). Each R 1 is independently selected from the group consisting of C1-C 30 hydrocarbyl) relates to a mixture of

[0054] In an embodiment, the composition of the mixture of the second aspect can be the same as the composition of the crosslinking agent of the first aspect.

[0055] Any feature of the second aspect can be as described correspondingly in the first aspect.

[0056] In a third aspect, the present invention provides a compound of general formula (I) selected from the list consisting of: a) a compound in which one of the Q' groups is a group of the formula COOCH2CH2CH2CH3 and two of the Q' groups are groups of the formula COO-[CH2-CH2-O-]2CH3; b) a compound in which one of the Q' groups is a group of the formula COOCH2CH2CH2CH3 and two of the Q' groups are groups of the formula COO-[CH2-CH2-O-]2CH2CH2CH2CH3; c) a compound in which one of the Q' groups is a group of the formula COOCH2CH2CH2CH3 and two of the Q' groups are groups of the formula COO-[CH2-CH(CH3)-O-]2CH3; d) a compound in which one of the Q' groups is a group of the formula COOCH2CH2CH2CH3 and two of the Q' groups are groups of the formula COOCH2CH2OCH2CH2CH2CH3; and e) a compound in which one of the Q' groups is a group of the formula COOCH2CH2CH2CH3 and two of the Q' groups are groups of the formula COO-[CH2-CH2-O-]2CH2CH3.

Chemical formula

[0057] In some embodiments, these compounds are examples of individual compounds present in the crosslinking agent of the first aspect or the mixture of the second aspect.

[0058] In a first preferred embodiment, the present invention provides A compound of general formula (I) in which one of the Q' groups is a group of the formula COOCH2CH2CH2CH3 and two of the Q' groups are groups of the formula COO-[CH2-CH2-O-]2CH3 [Chemical formula] relates to

[0059] In a second preferred embodiment, the present invention A compound of general formula (I) in which one of the Q' groups is a group of the formula COOCH2CH2CH2CH3 and two of the Q' groups are groups of the formula COO-[CH2-CH2-O-]2CH2CH2CH2CH3 [Chemical formula] relates to

[0060] In a third preferred embodiment, the present invention A compound of general formula (I) in which one of the Q' groups is a group of the formula COOCH2CH2CH2CH3 and two of the Q' groups are groups of the formula COO-[CH2-CH(CH3)-O-]2CH3 [Chemical formula] relates to

[0061] In a fourth preferred embodiment, the present invention A compound of general formula (I) in which one of the Q' groups is a group of the formula COOCH2CH2CH2CH3 and two of the Q' groups are groups of the formula COOCH2CH2OCH2CH2CH2CH3 [Chemical formula] relates to

[0062] In a fifth preferred embodiment, the present invention A compound of general formula (I) in which one of the Q' groups is a group of the formula COOCH2CH2CH2CH3 and two of the Q' groups are groups of the formula COO-[CH2-CH2-O-]2CH2CH3 [Chemical formula] relates to

[0063] In a fourth aspect, the present invention relates to an aqueous (coating) composition comprising a crosslinking agent according to any embodiment of the first aspect, a mixture according to any embodiment of the second aspect, or a compound according to any embodiment of the third aspect.

[0064] In embodiments, the aqueous composition may comprise 5 to 50% by weight of water, preferably 10 to 25% by weight of water.

[0065] Preferably, the aqueous composition does not contain any organic solvents. In embodiments, the aqueous composition may comprise 0 to 10% by weight, preferably 0 to 4% by weight, of a water-miscible organic solvent. These small amounts of organic solvents still qualify the aqueous composition as a low-VOC aqueous composition.

[0066] Preferably, the total amount of water and water-miscible organic solvent does not exceed 50% by weight.

[0067] In embodiments, the aqueous composition may comprise 5 to 50% by weight of water and 0 to 50% by weight, preferably 0 to 10% by weight, more preferably 0 to 4% by weight, of a water-miscible organic solvent, and the total amount of water and water-miscible organic solvent does not exceed 50% by weight.

[0068] Preferably, the aqueous composition may comprise 10 to 25% by weight of water and 0 to 10% by weight, preferably 0 to 4% by weight, of a water-miscible organic solvent.

[0069] When present, any water-miscible organic solvent is suitable. Preferably, the organic solvent may comprise a compound having the following general formula X=HO-[-X’-] j -R 3

[0070] In the formula, R 3 is independently selected from the group consisting of C1-C 30 hydrocarbyl, preferably R 1 is equal to.

[0071] In the formula, X’ is independently selected from the group consisting of CH2-CH2-O, CH2-CH(CH3)-O, CH(CH3)-CH2-O-, CH2-C(CH3)2-O-, CH2-CHVin-O, CHVin-CH2-O, CH2-CHPh-O-, and CHPh-CH2-O (wherein Ph is phenyl and Vin is vinyl), preferably equal to X.

[0072] In the formula, j is independently selected from integers from 1 to 50, preferably equal to i.

[0073] In an embodiment, the aqueous dispersion may comprise a crosslinking agent according to any embodiment of the first aspect, a mixture according to any embodiment of the second aspect, or a compound according to any embodiment of the third aspect in an amount of 50 to 95% by weight.

[0074] In an embodiment, the sum of a) water, b) an optional water-miscible organic solvent, and c) a crosslinking agent according to any embodiment of the first aspect, a mixture according to any embodiment of the second aspect, or a compound according to any embodiment of the third aspect is at least 90% by weight, preferably at least 95% by weight, more preferably at least 99% by weight, and most preferably substantially all of the aqueous dispersion.

[0075] Any feature of the fourth aspect may be as correspondingly described in the first aspect, the second aspect, or the third aspect.

[0076] In a fifth aspect, the present invention provides, in the absence of a catalyst, one or more compounds of general formula (II)

Chemical formula

[0077] If one or more compounds of general formula (II) are obtained (e.g., purchased) and dissolved in an organic solvent, at least 90 wt%, preferably 95 wt% or more of this solvent can be advantageously removed according to techniques well known to those skilled in the art before adding one or more compounds of general formula (III).

[0078] Performing this preliminary solvent removal step is particularly beneficial when (III) has a boiling point of 140 °C or lower.

[0079] In an embodiment, the molar ratio of the compound of general formula (II) to the compound of general formula (III) can be from 1:4.5 to 1:1.5. Preferably, this ratio can be from 1:4 to 1:2, more preferably, this ratio can be from 1:3.5 to 1:2.5. Most preferably, this ratio is 1:3. Such a ratio is advantageous as it gives the best self-crosslinking performance and generally gives very good water resistance and solvent resistance after co-crosslinking.

[0080] (II) The reaction between (II) and (III) is preferably carried out under an inert atmosphere, for example in nitrogen, according to techniques well known to those skilled in the art. The reaction temperature typically falls within the range of 60 to 180 °C, and the reaction pressure typically falls within the range of 50 to 500 mbar.

[0081] The method according to the fifth aspect does not require a catalyst. The inventors have surprisingly even noticed that better results can be obtained when no catalyst is used.

[0082] At the end of the reaction, water can be added to form an aqueous composition, especially an aqueous dispersion. The water is preferably added gradually. The water is preferably added until the solids content in the aqueous composition reaches 75 to 95% by weight.

[0083] In addition to water, a water-miscible organic solvent can be added to reach a final solids content in the range of 40 to 94% by weight. An example of a suitable water-miscible organic solvent is ethylene glycol monobutyl ether. Adding such a solvent can help reduce the viscosity of the dispersion.

[0084] Any feature of the fifth aspect can be as correspondingly described in the first, second, or third aspect.

[0085] In a sixth aspect, the present invention relates to a method of forming a coating, the method comprising reacting a crosslinking agent according to any embodiment of the first aspect, a mixture according to any embodiment of the second aspect, or a compound according to any embodiment of the third aspect with itself, provided that the reaction is carried out in the presence of a further compound other than a compound containing a 1,3,5-triazine carbamate moiety that can condense with the compound of general formula (I) and that is at most 30 wt%, at most 25 wt%, at most 20 wt%, at most 15 wt%, at most 10 wt%, at most 5 wt%, at most 3 wt%, or even at most 1 wt% based on the amount of the compound of general formula (I). This means that when 100 g of the compound of general formula (I) is present in the reaction medium, there may be present in the reaction medium 30 g or less, 25 g or less, 20 g or less, 15 g or less, 10 g or less, 5 g or less, or even 1 g or less of a compound other than a compound containing a 1,3,5-triazine carbamate moiety that can condense with the compound of general formula (I).

[0086] Typically, in a sixth aspect, the present invention relates to a method of forming a coating, the method comprising reacting a crosslinking agent according to any embodiment of the first aspect, a mixture according to any embodiment of the second aspect, or a compound according to any embodiment of the third aspect with itself, provided that the reaction is carried out in the presence of a further compound that does not correspond to general formula (I) but that can condense with the compound of general formula (I) and that is at most 30 wt%, at most 25 wt%, at most 20 wt%, at most 15 wt%, at most 10 wt%, at most 5 wt%, at most 3 wt%, or even at most 1 wt% based on the amount of the compound of general formula (I).

[0087] In other words, in a sixth aspect, the present invention relates to the use of a crosslinking agent according to any embodiment of the first aspect, a mixture according to any embodiment of the second aspect, or a compound according to any embodiment of the third aspect for forming a coating by self-crosslinking.

[0088] In an embodiment, the coating can be as described below in a seventh aspect.

[0089] The reaction referred to in the sixth aspect is a self-crosslinking reaction, i.e., a crosslinking reaction that occurs between a) a crosslinking agent according to any embodiment of the first aspect, a mixture according to any embodiment of the second aspect, or a compound according to any embodiment of the third aspect, and b) itself. The crosslinking agent according to any embodiment of the first aspect, the mixture according to any embodiment of the second aspect, and the compound according to any embodiment of the third aspect all have the property that they can react with themselves, thereby forming a crosslinked network and thereby forming a crosslinked product (typically a film or a coating).

[0090] In embodiments, the self-crosslinking reaction is carried out in the presence of a further compound other than a compound containing a 1,3,5-triazine carbamate moiety that can condense with the compound of general formula (I), up to 30 wt%, preferably up to 25 wt%, more preferably up to 20 wt%, still more preferably up to 15 wt%, still more preferably up to 10 wt%, still more preferably up to 5 wt%, even more preferably up to 3 wt%, and even more preferably up to 1 wt% based on the amount of the compound of general formula (I).

[0091] This means that in these embodiments, a compound (other than those containing a 1,3,5-triazine carbamate moiety) that does not correspond to general formula (I) but can condense with the crosslinking agent, mixture, or compound according to general formula (I), up to 30 wt%, up to 25 wt%, up to 20 wt%, up to 15 wt%, up to 10 wt%, up to 5 wt%, up to 3 wt%, or even up to 1 wt% can be present during the reaction. The reason for allowing up to 30 wt% of a compound not corresponding to general formula (I) is that in the presence of such small amounts of other reactive compounds, the reaction remains mostly a self-crosslinking reaction.

[0092] Most preferably, the self-crosslinking reaction is carried out in the absence of further compounds other than those containing a 1,3,5-triazine carbamate moiety that can condense with the compound of general formula (I). This means that in these embodiments, the only further compounds that are allowed to be present during the self-crosslinking reaction are those that contain a 1,3,5-triazine carbamate moiety but do not fall within general formula (I). This also means that in these embodiments, further compounds (other than those containing a 1,3,5-triazine carbamate moiety) that can condense with the compound of general formula (I) cannot be present during the reaction. This exception is due to the fact that during the formation of the crosslinking agent according to the first aspect, a small amount of by-products that contain a 1,3,5-triazine carbamate moiety but do not fall within general formula (I) may be formed. The presence of such by-products typically does not significantly interfere with the properties of the crosslinking agent according to the first aspect, the mixture according to the second aspect, or the compound according to the third aspect. Furthermore, removing such by-products is time-consuming, energy-consuming, and wasteful. Therefore, these by-products typically are not removed from the crosslinking agent according to the first aspect after their synthesis.

[0093] In embodiments, the reaction step may include subjecting the crosslinking agent to a temperature of at least 120 °C, or even at least 130 °C. For example, the reaction step may include subjecting the crosslinking agent to a temperature in the range of 120 °C to 190 °C.

[0094] In embodiments, the further compounds that can condense with the compound of general formula (I) may have one or more of the following functional groups: aldehyde, hydroxyl, epoxide, carboxylic acid, and anhydride.

[0095] Any feature of the sixth aspect may be as described correspondingly in the first, second, third, or seventh aspect.

[0096] In a seventh aspect, the present invention relates to a coating comprising a crosslinked crosslinking agent according to any embodiment of the first aspect, a crosslinked mixture according to any embodiment of the second aspect, or a crosslinked compound according to any embodiment of the third aspect, provided that no additional compound other than a compound comprising a 1,3,5-triazine carbamate moiety is condensed with the compound of general formula (I), or at most 30% by weight, preferably at most 25% by weight, more preferably at most 20% by weight, still more preferably at most 15% by weight, still more preferably at most 10% by weight, still more preferably at most 5% by weight, even more preferably at most 3% by weight, and yet even more preferably at most 1% by weight, based on the amount of the compound of general formula (I), of an additional compound other than a compound comprising a 1,3,5-triazine carbamate moiety is condensed with the compound of general formula (I).

[0097] Typically, in a seventh aspect, the present invention relates to a coating comprising a crosslinked crosslinking agent according to any embodiment of the first aspect, a crosslinked mixture according to any embodiment of the second aspect, or a crosslinked compound according to any embodiment of the third aspect, provided that no additional compound not corresponding to general formula (I) is condensed with the compound of general formula (I), or at most 30% by weight, preferably at most 25% by weight, more preferably at most 20% by weight, still more preferably at most 15% by weight, still more preferably at most 10% by weight, still more preferably at most 5% by weight, even more preferably at most 3% by weight, and yet even more preferably at most 1% by weight, based on the amount of the compound of general formula (I), of an additional compound not corresponding to general formula (I) is condensed with the compound of general formula (I).

[0098] In embodiments, the coating may be able to withstand at least 70, preferably at least 80, more preferably at least 100, even more preferably at least 120, even more preferably at least 150, even more preferably at least 175, and even more preferably at least 200 double rubs with MEK as measured according to the test methods described in the examples section.

[0099] In an embodiment, the further compound capable of condensing with the compound of general formula (I) has one or more of the following functional groups: aldehyde, hydroxyl, epoxide, carboxylic acid, and anhydride.

[0100] Any feature of the seventh aspect may be as described correspondingly in the first, second, third, or sixth aspect.

[0101] In an eighth aspect, the present invention relates to a method of co-crosslinking a crosslinking agent according to any embodiment of the first aspect, a mixture according to any embodiment of the second aspect, or a compound according to any embodiment of the third aspect with a further compound, the method comprising heating the crosslinking agent, mixture, or compound and the further compound at a temperature of 100 to 150 °C or even 110 to 150 °C.

[0102] A crosslinking agent according to any embodiment of the first aspect, a mixture according to any embodiment of the second aspect, or a compound according to any embodiment of the third aspect can be co-crosslinked with various further compounds. Examples of suitable further compounds are comonomers, oligomers, and polymers, such as hydroxyl-containing monomers, oligomers, and polymers; epoxide-containing monomers, oligomers, and polymers; and carboxylic acid-containing monomers, oligomers, and polymers.

[0103] On the one hand, a mixture of a crosslinking agent according to any embodiment of the first aspect, a mixture according to any embodiment of the second aspect, or a compound according to any embodiment of the third aspect and, on the other hand, a further compound can be included in a coating composition, particularly a low-VOC aqueous composition.

[0104] In an advantageous aspect, the further compound for use herein is an acrylic polyol. Exemplary suitable acrylic polyol polymers for use herein include those commercially available under the trade names Viacryl®, Setaqua®, or Macrynal® from Allnex USA, INC.

[0105] This crosslinking can occur with or without a catalyst and typically requires heating.

[0106] The resulting coating is typically suitable for protecting the surface.

[0107] Any feature of the eighth aspect may be as described correspondingly in the first, second, or third aspect.

Examples

[0108] The present disclosure is further illustrated by the following examples. These examples are for illustrative purposes only and are not meant to limit the appended claims.

[0109] Example 1: Reaction between tris((methyl / butyl)carbamate)triazine and 2-(2-methoxyethoxy)ethanol at a molar ratio of triazine to alcohol of 1:3 Into a 500 ml four-necked glass flask equipped with a glass stirrer, a thermocouple, a distillation bridge, and a Liebig condenser, 242 g (0.32 mol) of 1,3,5-triazine containing a combination of butylcarbamate functional groups and methylcarbamate functional groups (present at 50 wt% in butanol and commercially available from Allnex under the trade name Cymel® NF2000A) was charged. Distillation was carried out by gradually increasing the temperature from 70 °C to 150 °C under a reduced pressure of 100 mbar until the weight of the compounds present in the glass flask decreased to 136 g, indicating almost complete removal of the butanol solvent.

[0110] Next, the flask and its contents were returned to atmospheric pressure under a nitrogen atmosphere and cooled to 100 °C. Then, 118 g (0.98 mol) of 2-(2-methoxyethoxy)ethanol was mixed with 1,3,5-triazine. The temperature of the reaction mixture was gradually raised under atmospheric pressure in a nitrogen atmosphere and maintained at 120 - 130 °C for 30 minutes to promote the exchange of the alkyl chains present on 1,3,5-triazine with 2-(2-methoxyethoxy)ethanol. Next, the vacuum was gradually increased from 350 mbar to 80 mbar under a nitrogen atmosphere, and then the temperature was gradually raised to 150 °C. The reaction mixture was maintained at 80 mbar and 150 °C with stirring until no further condensation of the distillate was observed, thereby obtaining 173 g of the final product. When all the solvent had been distilled off, the reaction temperature was lowered to 80 °C and 48 g of water was added stepwise, thereby obtaining an adduct that was 78 wt% in water.

[0111] From 13C NMR, about 65 mol% substitution of the alkylated species (average 2-substitution of 2-(2-methoxyethoxy)ethylcarbamate functional groups on each triazine molecule) was achieved.

[0112] From LC-MS, a similar degree of substitution was confirmed (64 mol%). Also, by LC-MS, the proportion of tris(2-(2-methoxyethoxy)ethylcarbamate) in the triazine could be evaluated to be 21 mol%.

[0113] Example 2: Reaction between tris((methyl / butyl)carbamate)triazine and 2-(2-methoxyethoxy)ethanol at a triazine to alcohol molar ratio of 1:4.5 A 500 ml four-necked glass flask equipped with a glass stirrer, a thermocouple, a distillation bridge, and a Liebig condenser was charged with 201 g (0.27 mol) of a 1,3,5-triazine containing a combination of butylcarbamate and methylcarbamate functional groups (present at 50 wt% in butanol and commercially available from Allnex under the trade name Cymel® NF2000A). Distillation was carried out by gradually increasing the temperature from 70 °C to 150 °C under a reduced pressure of 100 mbar until the weight of the compounds present in the glass flask decreased to 113 g, indicating almost complete removal of the butanol solvent.

[0114] Next, the flask and its contents were returned to atmospheric pressure under a nitrogen atmosphere and cooled to 100 °C. Then, 147 g (1.22 mol) of 2-(2-methoxyethoxy)ethanol was mixed with the 1,3,5-triazine. The temperature of the reaction mixture was gradually increased under atmospheric pressure in a nitrogen atmosphere and maintained at 120 - 130 °C for 30 minutes to promote the exchange of the alkyl chains present on the 1,3,5-triazine with 2-(2-methoxyethoxy)ethanol. Then, the vacuum was gradually increased from 350 mbar to 80 mbar under a nitrogen atmosphere and the temperature was gradually increased to 150 °C. The reaction was maintained at 80 mbar and 150 °C with stirring until no further condensation of the distillate was observed, thereby obtaining 150 g of the final product. When all the solvent had been distilled off, the reaction temperature was lowered to 80 °C and 36 g of water was added stepwise, thereby obtaining an 81 wt% adduct in water.

[0115] From 13C NMR, substitution of approximately 77 mol% of the alkylated species (average 2.3 substitutions of 2-(2-methoxyethoxy)ethylcarbamate functional groups on each triazine molecule) was achieved.

[0116] From LC-MS, a similar degree of substitution was confirmed (76 mol%). Also, from LC-MS, the proportion of tris(2-(2-methoxyethoxy)ethylcarbamate) in the triazine could be evaluated to be 39 mol%.

[0117] Example 3: Reaction between tris((methyl / butyl)carbamate)triazine and 2-(2-methoxyethoxy)ethanol at a molar ratio of triazine to alcohol of 1:1.5 Into a 500 ml four-necked glass flask equipped with a glass stirrer, a thermocouple, a distillation bridge, and a Liebig condenser, 270 g (0.37 mol) of 1,3,5-triazine containing a combination of butylcarbamate functional groups and methylcarbamate functional groups (present at 50 wt% in butanol and commercially available from Allnex under the trade name Cymel® NF2000A) was charged. Distillation was carried out by gradually increasing the temperature from 70 °C to 150 °C under a reduced pressure of 100 mbar until the weight of the compounds present in the glass flask decreased to 145.1 g, indicating almost complete removal of the butanol solvent.

[0118] Next, the flask and its contents were returned to atmospheric pressure under a nitrogen atmosphere and cooled to 100 °C. Then, 66 g (0.55 mol) of 2-(2-methoxyethoxy)ethanol was mixed with the 1,3,5-triazine. The temperature of the reaction mixture was gradually increased under atmospheric pressure combined with a nitrogen atmosphere and maintained at 120 - 130 °C for 30 minutes to promote the exchange of the alkyl chains present on the 1,3,5-triazine by 2-(2-methoxyethoxy)ethanol. Then, the vacuum was gradually increased from 350 mbar to 80 mbar under a nitrogen atmosphere and the temperature was gradually increased to 150 °C.

[0119] The reaction product was maintained at 80 mbar and 150 °C with stirring until no further condensation of the distillate was observed, thereby obtaining 180 g of the final product. Once all the solvent had been distilled off, the reaction temperature was lowered to 80 °C and 10 g of water was added in portions. To further reduce the viscosity, 31 g of 2-butoxyethanol solvent was added, thereby obtaining a solid adduct of 80 wt% in water.

[0120] From 13C NMR, substitution of approximately 39 mol% of the alkylated species (an average of 1.17 substitutions of 2-(2-methoxyethoxy)ethylcarbamate functional groups per triazine molecule) was achieved.

[0121] From LC-MS, a similar degree of substitution was confirmed (39 mol%). Also, by LC-MS, the proportion of tris(2-(2-methoxyethoxy)ethylcarbamate) in the triazine could be evaluated to be 5 mol%.

[0122] The chemical compositions of the crosslinking agents of Examples 1 to 3 are summarized in Table 1 below: [Table 1]

[0123] Example 4: Reaction between tris((methyl / butyl)carbamate)triazine and 2-butoxyethanol at a molar ratio of triazine to alcohol of 1:3 Into a 500 ml four-necked glass flask equipped with a glass stirrer, a thermocouple, a distillation bridge, and a Liebig condenser, 270 g (0.37 mol) of 1,3,5-triazine containing a combination of butylcarbamate functional groups and methylcarbamate functional groups (present at 50 wt% in butanol and commercially available from Allnex under the trade name Cymel® NF2000A) was charged. Distillation was carried out by gradually increasing the temperature from 70 °C to 150 °C under a reduced pressure of 100 mbar until the weight of the compounds present in the glass flask decreased to 145.1 g, showing almost complete evaporation of the butanol.

[0124] Next, the flask and its contents were returned to atmospheric pressure under a nitrogen atmosphere and cooled to 100 °C. Then, 116 g (0.98 mol) of 2-butoxyethanol was mixed with 1,3,5-triazine. The temperature of the reaction mixture was gradually raised under atmospheric pressure in a nitrogen atmosphere and maintained at 120 - 130 °C for 30 minutes to promote the exchange of the alkyl chains present on 1,3,5-triazine with 2-butoxyethanol. Next, the vacuum was gradually increased from 350 mbar to 80 mbar under a nitrogen atmosphere and the temperature was gradually raised to 150 °C. The reaction product was maintained at 80 mbar and 150 °C with stirring until no further condensation of the distillate was observed, thereby obtaining 165 g of the final product. When all the solvent had been distilled off, the reaction temperature was lowered to 80 °C and 9 g of water was slowly added. To further reduce the viscosity, 40 g of 2-butoxyethanol solvent was added, thereby obtaining an adduct of 77 wt% in water and 2-butoxyethanol.

[0125] From 13C NMR, substitution of about 53 mol% of the alkylated species (average 1.59 substitutions of 2-butoxyethylcarbamate functional groups on each triazine molecule) was achieved.

[0126] Example 5: Reaction between tris((methyl / butyl)carbamate)triazine and 2-(2-butoxyethoxy)ethanol at a molar ratio of triazine to alcohol of 1:3 in a single distillation step A 500 ml four-necked glass flask equipped with a glass stirrer, a thermocouple, a distillation bridge, and a Liebig condenser was charged with 223 g (0.30 mol) of 1,3,5-triazine containing a combination of butylcarbamate and methylcarbamate functional groups (present at 50 wt% in butanol and commercially available from Allnex under the trade name Cymel® NF2000A). Then, 147 g (0.91 mol) of 2-(2-butoxyethoxy)ethanol was mixed with 1,3,5-triazine. The temperature of the reaction mixture was gradually raised to 80 °C under a nitrogen atmosphere. Next, the reaction mixture was slowly brought to a reduced pressure of 80 mbar under a nitrogen atmosphere while simultaneously raising the temperature from 80 °C to 150 °C, thereby performing distillation and reaction simultaneously.

[0127] Next, the temperature was maintained at 150 °C at a pressure of 80 mbar while stirring until further condensation of the distillate was no longer observed, thereby obtaining 189 g of the final product. The reaction temperature was then lowered to 80 °C, and 29 g of water and 41 g of 2-butoxyethanol solvent were added stepwise, thereby obtaining an adduct of 73 wt% in water and 2-butoxyethanol.

[0128] From 13C NMR, substitution of about 63 mol% of the alkylating species (average of 1.89 substitutions of the 2-(2-butoxyethoxy)ethylcarbamate functional groups on each triazine molecule) was achieved.

[0129] From LC-MS, a similar degree of substitution was confirmed (61 mol%). Also, LC-MS allowed the proportion of tris(2-(2-butoxyethoxy)ethylcarbamate) in the triazine to be estimated at 30 mol%.

[0130] Example 6: Reaction between tris((methyl / butyl)carbamate)triazine and dipropylene glycol monomethyl ether at a molar ratio of triazine to alcohol of 1:3 in a single distillation step Into a 500 ml four-necked glass flask equipped with a glass stirrer, a thermocouple, a distillation bridge, and a Liebig condenser, 221 g (0.30 mol) of 1,3,5-triazine containing a combination of butylcarbamate and methylcarbamate functional groups (present at 50 wt% in butanol and commercially available from Allnex under the trade name Cymel® NF2000A) was charged. Next, 132.8 g (0.90 mol) of dipropylene glycol monomethyl ether, commercially available under the trade name DOWANOL™ DPM Glycol Ether, was mixed with the 1,3,5-triazine. The temperature of the reaction mixture was gradually raised to 80 °C under a nitrogen atmosphere. The reaction mixture was then slowly brought to a reduced pressure of 80 mbar under a nitrogen atmosphere while simultaneously raising the temperature from 80 °C to 150 °C, thereby performing distillation and reaction simultaneously. The temperature was then maintained at 150 °C at a pressure of 80 mbar while stirring until no further condensation of the distillate was observed, thereby obtaining 147 g of the final product. When all the solvent had been distilled off, the reaction temperature was lowered to 80 °C and 9 g of water was added. To further reduce the viscosity, 48.5 g of 2-butoxyethanol was added stepwise, thereby obtaining an adduct of 72 wt% in water and 2-butoxyethanol.

[0131] From 13C NMR, about 40 mol% substitution of the alkylated species (average 1.21 substitutions of dipropylene glycol monomethyl ether carbamate functional groups on each triazine molecule) was achieved.

[0132] Example 7: Aqueous composition. Aqueous compositions could be obtained from all the crosslinking agents of Examples 1 to 6. Furthermore, all the crosslinking agents of the present invention exhibit excellent water dispersibility. To achieve good miscibility with water, no additional organic solvent was required for the crosslinking agents of Examples 1 and 2. For the crosslinking agents of Examples 3 to 6, a certain amount of organic solvent was beneficial to obtain good miscibility with water.

[0133] Example 8: Self-crosslinking performance. A coating was formed on a metal panel and subsequently heated at 140 °C for 30 minutes to evaluate the self-crosslinking properties of the crosslinking agent of the present invention and Cymel® NF2000A (as a comparative triazine). All of the resulting films were transparent. No catalyst was used in the self-crosslinking test.

[0134] The solvent resistance (methyl ethyl ketone double rub on metal) was evaluated by moving a cotton cloth saturated with methyl ethyl ketone back and forth and pressing it on the coating surface. One double rub is equal to the forward and backward stroke on the coating surface. The reported number is the number of double rubs required to break the coating. High solvent resistance is advantageous for ensuring good protection of the coating and the substrate against runoff in household or industrial products.

[0135] From these tests, it was concluded that the comparative tris((methyl / butyl)carbamate) triazine (Cymel® NF2000A) does not self-crosslink, while the crosslinking agent of the present invention does self-crosslink. The crosslinking agents obtained in all examples according to the present invention demonstrated excellent self-crosslinking properties, as evidenced by their ability to withstand at least 75, at least 100, at least 150, or even at least 200 methyl ethyl ketone double rubs. All other examples of the crosslinking agent according to the present invention showed good self-crosslinking properties with higher methyl ethyl ketone double rub resistance than the Cymel® NF2000A control, which failed prior to 40 double rubs of methyl ethyl ketone.

[0136] The results are summarized in Table 2 below:

Table 2

[0137] Example 9: Co-crosslinking in a low VOC formulation Comparative tris((methyl / butyl)carbamate)triazine Cymel® NF2000A provides many beneficial properties but is not water-soluble. This means that it can be used in water-dilutable resins and aqueous dispersions, but it is necessary to pre-blend it with the resin to be crosslinked and subsequently add a water-compatible organic solvent. However, this procedure does not necessarily enable the obtaining of a stable aqueous formulation. Furthermore, the resulting formulation has a relatively high VOC (volatile organic compound).

[0138] In contrast, the crosslinking agents of the present invention are typically aqueous or do not require many organic solvents to form a clear and stable composition. In the aqueous case, they are typically obtained with less than 2% by weight of organic solvent. Otherwise, 15% by weight or less of organic solvent is sufficient to be compatible with water.

[0139] Since these crosslinking agents do not contribute much to the volatile organic components (VOC) in the coating formulation, the formulations prepared using the crosslinking agents of the present invention and typical aqueous binders, particularly aqueous acrylic resins, show a significant reduction in VOC compared to the formulations prepared using Cymel® NF2000A and the binder.

[0140] The co-crosslinking properties of Cymel® NF2000A and the crosslinking agents of the present invention with an aqueous acrylic resin (commercially available from Allnex under the trade name Viacryl® 6276) were evaluated by forming a coating on a metal panel and subsequently heating the coating at a temperature of 115°C to 140°C for 30 minutes. All of the resulting films were transparent. No catalyst was used in the co-crosslinking test.

[0141] It was possible to obtain a low VOC formulation, but it is noteworthy that the polymer binder Viacryl® 6276 contains 3.2% by weight of organic solvent which necessarily increases the overall VOC value. The VOC results (g / L) and methyl ethyl ketone double friction results are shown in Table 3 below.

Table 3

[0142] As easily observed in Table 3, the co-crosslinking performance of the crosslinking agent according to the present invention using the exemplified aqueous acrylic resin Viacryl® 6276 is equivalent to that obtained with the Cymel® NF2000A control.

[0143] These co-crosslinking experiments were repeated with glass panels and paper panels instead of metal panels. Good methyl ethyl ketone double friction performance was also obtained on these substrates.

Claims

1. one or more compounds of general formula (II) 【Chemistry 1】 where each Q″ is a group of formula COOR ２ is the basis of Each R ２ is C １ ~C ３０ hydrocarbyl) with one or more compounds of general formula (III) [-[E-] ｉ R １ (III) wherein each X is CH ２ -CH ２ -O, CH ２ -CH(CH ３ )—O, CH(CH ３ )-CH ２ -O-, CH ２ -C(CH ３ ) ２ -O-, CH ２ -CHVin-O, CHVin-CH ２ -O, CH ２ -CHPh-O-, and CHPh-CH ２ -O, wherein Ph is phenyl and Vin is vinyl; each i is independently selected from an integer from 1 to 50; Each R １ is C １ ~C ３０ hydrocarbyl) a crosslinking agent obtainable by reacting Compounds of general formula (I) 【Chemistry 2】 (Wherein Q' is a group of the formula COO-[X-] ｉ R １ is the basis of each i is independently selected from an integer from 1 to 50 for 35 mol % or more of Q' in the mixture, and i is equal to 0 for the remaining Q' in said mixture; Each X is CH ２ -CH ２ -O, CH ２ -CH(CH ３ )—O, CH(CH ３ )-CH ２ -O-, CH ２ -C(CH ３ ) ２ -O-, CH ２ -CHVin-O, CHVin-CH ２ -O, CH ２ -CHPh-O-, and CHPh-CH ２ -O, wherein Ph is phenyl and Vin is vinyl; Each R １ is C １ ~C ３０ hydrocarbyl) A cross-linking agent comprising a mixture of

2. 2. The crosslinker of claim 1, wherein at least 70 mol % of the compounds of the mixture have at least one Q' group with i different from 0.

3. 2. The crosslinker of claim 1, wherein each i is independently selected from an integer from 1 to 50 for 59 to 77 mol % of Q' in the mixture, and i is equal to 0 for the remaining Q' in the mixture.

4. 4. The crosslinker of claim 3, wherein i is equal to 2 for 59-77 mol% of Q' in the mixture, and i is equal to 0 for the remaining Q' in the mixture.

5. Each X is —CH ２ -CH ２ —O and —CH ２ -CH(CH ３ 2. The crosslinker of claim 1, wherein the crosslinker is independently selected from the group consisting of:

6. R １ But C １ ~C ４ 10. The crosslinker of claim 1, independently selected from the group consisting of hydrocarbyls.

7. 2. The crosslinker of claim 1, wherein at least 5 mol % of the compounds of formula (I) in the mixture have i selected from integers from 1 to 50 for all three of their Q' groups.

8. An aqueous composition comprising the crosslinker of any one of claims 1 to 7.

9. In the absence of a catalyst, one or more compounds of general formula (II) 【Transformation 3】 (wherein Q″ is a group of the formula COOR ２ is the basis of Each R ２ is C １ ~C ３０ hydrocarbyl) with one or more compounds of general formula (III) [-[E-] ｉ R １ (III) wherein each X is CH ２ -CH ２ -O, CH ２ -CH(CH ３ )—O, CH(CH ３ )-CH ２ -O-, CH ２ -C(CH ３ ) ２ -O-, CH ２ -CHVin-O, CHVin-CH ２ -O, CH ２ -CHPh-O-, and CHPh-CH ２ -O, wherein Ph is phenyl and Vin is vinyl; each i is independently selected from an integer from 1 to 50; Each R １ is C １ ~C ３０ hydrocarbyl) 8. A method of forming the crosslinker of claim 1, comprising reacting

10. 10. A method for forming a coating, comprising the step of reacting a crosslinker according to any one of claims 1 to 7 with itself, with the proviso that said reaction is carried out in the presence of up to 30% by weight, relative to the amount of the compound of general formula (I), of a further compound other than a compound comprising a 1,3,5-triazine carbamate moiety, capable of condensing with the compound of general formula (I).

11. 11. The method of claim 10, wherein the further compound capable of condensing with the compound of general formula (I) has one or more of the following functional groups: aldehyde, hydroxyl, epoxide, carboxylic acid, and anhydride.

12. 11. The method of claim 10, wherein the reacting step comprises subjecting the cross-linking agent to a temperature of at least 120°C.

13. 8. A coating comprising the crosslinked crosslinker according to any one of claims 1 to 7, with the proviso that no further compounds other than the compound comprising a 1,3,5-triazine carbamate moiety are condensed with the compound of general formula (I) or up to 30% by weight, relative to the amount of the compound of general formula (I), of further compounds other than the further compound comprising a 1,3,5-triazine carbamate moiety are condensed with the compound of general formula (I).

14. 8. A method for co-crosslinking the crosslinker of any one of claims 1 to 7 with a further compound, the method comprising the step of heating the crosslinker and the further compound at a temperature of 100-150°C.

15. a) one of the Q' groups is of the formula COOCH ２ CH ２ CH ２ CH ３ and two of the Q′ groups are groups of the formula COO—[CH ２ -CH ２ -O-] ２ CH ３ b) a compound in which one of the Q′ groups is of the formula COOCH ２ CH ２ CH ２ CH ３ and two of the Q′ groups are groups of the formula COO—[CH ２ -CH ２ -O-] ２ CH ２ CH ２ CH ２ CH ３ c) compounds in which one of the Q' groups is a group of formula COOCH ２ CH ２ CH ２ CH ３ and two of the Q′ groups are groups of the formula COO—[CH ２ -CH(CH ３ )-O-] ２ CH ３ d) compounds in which one of the Q' groups is a group of formula COOCH ２ CH ２ CH ２ CH ３ , and two of the Q′ groups are groups of the formula COOCH ２ CH ２ OCH ２ CH ２ CH ２ CH ３ and e) compounds in which one of the Q' groups is a group of formula COOCH ２ CH ２ CH ２ CH ３ and two of the Q′ groups are groups of the formula COO—[CH ２ -CH ２ -O-] ２ CH ２ CH ３ a compound of general formula (I) selected from the list consisting of compounds which are in the group 【Chemistry 4】 。

Images