Triazine carbamate crosslinkers

Abstract

A cross-linking agent obtainable by reacting one or more compounds of the following general formula (II) with one or more compounds of the following general formula (III): # imgabs 0 # HO-[X-] iR1 (III) wherein the cross-linking agent comprises a mixture of compounds of the following general formula (I): # imgabs 1 # wherein Q'is a group of the formula COO-[X-] iR1; wherein, for 35 mol% or more of Q'in the mixture, each i is independently selected from an integer from 1 to 50, and for the remaining Q 'in the mixture, i is equal to 0, each X is independently selected from 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, Vin is vinyl, and each R1 is independently selected from a C1-C30 hydrocarbon group.

Description

Technical Field

[0001] The present invention relates to triazine urethane crosslinkers, particularly for use in coating compositions, more particularly aqueous formulations for forming coatings. Background Art

[0002] Tris(alkoxycarbonylamino)triazines are commercially available crosslinkers. Their chemical structure typically contains a combination of various alkylcarbamate functional groups. Because they are insoluble in water, they are typically provided in organic solvents such as n-butanol. Therefore, it is difficult to use them in waterborne coating formulations. An interesting feature of such compounds is that they do not contain formaldehyde or do not release formaldehyde when cured. Therefore, they are less toxic to humans. They are also particularly unsuitable for self-crosslinking reactions, i.e., they do not form films without other reactive compounds. When used to crosslink reactive compounds such as hydroxyl- and epoxy-containing polymers, they produce highly durable, acid-resistant films that achieve a good balance between hardness and flexibility. Such films are typically used in automotive topcoats, outer can varnishes, and coil coatings. Tris(alkoxycarbonylamino)triazines can be used as the sole crosslinker in a coating or ink formulation, or can be used in combination with other crosslinkers such as amino resins or isocyanates at lower levels to achieve a balance of properties.

[0003] In addition to tris(alkoxycarbonylamino)triazines, several other available formaldehyde-free crosslinking agents that provide carbamate functionality are also possible. Examples of such alternatives are isocyanates and blocked isocyanates. These can provide excellent performance but can generate hazardous blocking agents and free isocyanates. SUMMARY OF THE INVENTION

[0005] It was therefore an object of the present invention to provide a urethane crosslinker which at least partially overcomes some of the abovementioned disadvantages.

[0006] More specifically, it is an object of the present invention to provide a stable, water-compatible urethane crosslinker capable of achieving high crosslink densities with low environmental or toxicity concerns.

[0007] The cross-linking 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:

[0008] They are self-crosslinkable. This means that they are able to react with themselves to form a crosslinked product (usually a film). Therefore, apart from the crosslinking agent, mixture or compound itself, no further (additional) reactive compounds are required to obtain a crosslinked product. Thus, films can usually be obtained in the presence of only small amounts of other reactive compounds, or even in the absence of other reactive compounds.

[0009] They can be formaldehyde-free. This means that they do not need to contain formaldehyde, and usually do not contain formaldehyde. In addition, they do not release formaldehyde during the curing process. Therefore, their toxicity to humans is low.

[0010] • They are particularly suitable for forming low VOC (volatile organic compound) formulations because they tend to be dispersible in water.

[0011] They can form coatings with high crosslink density.

[0012] They are compatible with water-based acrylic, polyester and epoxy adhesives.

[0013] The aqueous dispersion of the fourth aspect may have one or more of the following advantages:

[0014] • It may be stable.

[0015] Its VOC content can be very low.

[0016] • It can form coatings with excellent solvent resistance on a variety of substrates, including metal, glass and paper.

[0017] In a first aspect, the present invention relates to a crosslinking agent obtainable by reacting one or more compounds of the general formula (II) with one or more compounds of the general formula (III):

[0018] HO-[X-] i R 1 (III)

[0019] in:

[0020] Each Q" is the formula COOR 2 A group in which each R 2 Independently selected from C1-C 30 Hydrocarbon,

[0021] Each X is independently selected from 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, Vin is vinyl,

[0022] Each i is independently selected from an integer of 1-50,

[0023] Each R 1 Independently selected from C1-C 30 Hydrocarbon,

[0024] The crosslinking agent comprises a mixture of compounds of the following general formula (I):

[0025]

[0026] Where Q' is of the formula COO-[X-] i R 1 A group in which:

[0027] For 35 mol% or more of Q' in the mixture, each i is independently selected from an integer of 1 to 50, and for the remainder of Q' in the mixture, i is equal to 0,

[0028] Each X is independently selected from 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, Vin is vinyl, and

[0029] Each R 1 Independently selected from C1-C 30 Hydrocarbon.

[0030] In a second aspect, the present invention relates to a mixture of compounds of the following general formula (I):

[0031]

[0032] Where Q' is of the formula COO-[X-] i R 1 A group in which:

[0033] For 35 mol% or more of Q' in the mixture, each i is independently selected from an integer of 1 to 50, and for the remainder of Q' in the mixture, i is equal to 0,

[0034] Each X is independently selected from 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, Vin is vinyl, and

[0035] Each R 1 Independently selected from C1-C 30 Hydrocarbon.

[0036] In a third aspect, the present invention relates to a compound of the following general formula (I):

[0037]

[0038] It is selected from the following compounds:

[0039] a) wherein one of the Q' groups is a group of the formula COOCH2CH2CH2CH3, and wherein two of the Q' groups are a group of the formula COO-[CH2-CH2-O-]2CH3;

[0040] b) wherein one of the Q' groups is a group of the formula COOCH2CH2CH2CH3, and wherein two of the Q' groups are a group of the formula COO-[CH2-CH2-O-]2CH2CH2CH2CH3;

[0041] c) wherein one of the Q' groups is a group of the formula COOCH2CH2CH2CH3, and wherein two of the Q' groups are a group of the formula COO-[CH2-CH(CH3)-O-]2CH3;

[0042] d) wherein one of the Q' groups is a group of the formula COOCH2CH2CH2CH3, and wherein two of the Q' groups are groups of the formula COOCH2CH2OCH2CH2CH2CH3; and

[0043] e) wherein one of the Q' groups is a group of the formula COOCH2CH2CH2CH3, and wherein two of the Q' groups are a group of the formula COO-[CH2-CH2-O-]2CH2CH3.

[0044] In a fourth aspect, the present invention relates to an aqueous (coating) composition comprising one of the crosslinking agent of any embodiment of the first aspect, the mixture of any embodiment of the second aspect, or the compound of any embodiment of the third aspect.

[0045] In a fifth aspect, the present invention relates to a method of forming the crosslinking agent of the first aspect, the mixture of the second aspect or the compound of the third aspect, comprising the step of reacting one or more compounds of the general formula (II) with one or more compounds of the general formula (III) in the absence of a catalyst:

[0046] HO-[X-] i R 1 (III)

[0047] in:

[0048] Q" is COOR 2 A group in which each R 2 Independently selected from C1-C 30 Hydrocarbon,

[0049] Each X is independently selected from 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, Vin is vinyl,

[0050] Each i is independently selected from an integer from 1 to 50, and

[0051] Each R 1 Independently selected from C1-C 30 Hydrocarbon.

[0052] In a sixth aspect, the present invention relates to a method for forming a coating, which comprises reacting a crosslinker of any embodiment of the first aspect, a mixture of any embodiment of the second aspect, or a compound of any embodiment of the third aspect with itself, provided that: the reaction is carried out in the presence of up to 30 wt% of an additional compound capable of condensing with the compound of general formula (I) and different from the compound containing a 1,3,5-triazine carbamate portion, wherein the wt% is relative to the amount of the compound of general formula (I).

[0053] In the seventh aspect, the present invention relates to a coating comprising a crosslinked crosslinker of any embodiment of the first aspect, a crosslinked mixture of any embodiment of the second aspect, or a crosslinked compound of any embodiment of the third aspect, provided that: no additional compound different from the compound containing the 1,3,5-triazine carbamate portion is condensed with the compound of general formula (I), or up to 30 wt% of the additional compound different from the compound containing the 1,3,5-triazine carbamate portion is condensed with the compound of general formula (I) relative to the amount of the compound of general formula (I).

[0054] In an eighth aspect, the present invention relates to a method for co-crosslinking a crosslinker of any embodiment of the first aspect, a mixture of any embodiment of the second aspect, or a compound of any embodiment of the third aspect with an additional compound, the method comprising the step of heating the mixture and the additional compound at a temperature of 100-150°C. DETAILED DESCRIPTION OF THE INVENTION

[0056] As used herein and unless otherwise indicated, the term "aqueous (water-containing) composition" is used to refer to water-based solutions, water-based dispersions, and water-based emulsions. As is generally known in the art, the term "water-based solution" refers to a compound, typically oligomer and / or polymer particles, mixed with an aqueous medium in a continuous phase. The term "water-based dispersion" refers to a mixture in which a compound is dispersed as insoluble particles in an aqueous medium. The term "water-based emulsion" refers to a mixture in which a compound is suspended as droplets throughout an aqueous medium.

[0057] In a first aspect, the present invention relates to a crosslinking agent obtainable by reacting one or more compounds of the general formula (II) with one or more compounds of the general formula (III):

[0058] HO-[X-] i R 1 (III)

[0059] in:

[0060] Each Q" is the formula COOR 2 A group in which each R 2 Independently selected from C1-C 30 Hydrocarbon,

[0061] Each X is independently selected from 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, Vin is vinyl,

[0062] Each i is independently selected from an integer of 1-50,

[0063] Each R 1 Independently selected from C1-C 30 Hydrocarbon,

[0064] The crosslinking agent comprises a mixture of compounds of the following general formula (I):

[0065]

[0066] Where Q' is of the formula COO-[X-] i R 1 A group in which:

[0067] For 35 mol% or more of Q' in the mixture, each i is independently selected from an integer of 1 to 50, and for the remainder of Q' in the mixture, i is equal to 0,

[0068] Each X is independently selected from 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, Vin is vinyl, and

[0069] Each R 1 Independently selected from C1-C 30 Hydrocarbon.

[0070] The cross-linking agent of the present invention can be obtained by transcarbamylation reaction, wherein the formula [X-] i R 1 The group replaces the hydrocarbon chain R in the general formula (II) 2 To obtain the general formula (I). The compound (II) used herein can be a pure compound or a mixture of compounds of the general formula (II). The compound of the general formula (II) is most easily obtained in the form of a mixture of compounds of the general formula (II), and such a mixture of compounds is an acceptable starting material for preparing the crosslinking agent, mixture or compound of the present invention.

[0071] The general formula (II) can also be expressed in its expanded form:

[0072]

[0073] The compounds of general formula (II) are known as tris(alkoxycarbonylamino)triazines (sometimes also referred to as TACT).

[0074] R 2 Independently selected from C1-C 30 Hydrocarbyl, preferably C1-C 15 Hydrocarbyl, more preferably C1-C 12 A hydrocarbon group, more preferably a C1-C8 hydrocarbon group, still more preferably a C1-C6 hydrocarbon group, still more preferably a C1-C4 hydrocarbon group, and even more preferably a C1 and C4 hydrocarbon group (eg, n-butyl). 2 is a linear hydrocarbon chain. 2 The advantage of the crosslinkers of the first aspect obtained from compounds (II) which are relatively short hydrocarbyl chains is that they are expected to be more efficient than those obtained from compounds wherein R 2 The crosslinking agents of the first aspect obtained for compounds (II) with relatively long hydrocarbon chains are more compatible with water. 2 The chains also have improved water compatibility relative to the starting materials.

[0075] An example of one or more compounds of the general formula (II) is a compound wherein all the groups R 2are all methyl compounds, where all groups R 2 are all compounds containing n-butyl, and some of the groups R 2 is methyl and other groups R 2 A mixture of compounds of the general formula (II) containing a compound having an n-butyl group. A specific example of such a mixture is NF2000, commercially available from allnex USA, Inc.

[0076] It has also been observed that the group [X-] present in compound (I) i R 1 The exact nature of (III) can vary within defined limits while maintaining its advantageous properties. Therefore, it is acceptable to use more than one different compound (III) to prepare compound (I). However, it is simpler to use a single compound (I).

[0077] Various possible Xs share certain hydrophilicity and length.

[0078] In some embodiments, each X can be independently selected from -CH2-CH2-O and -CH2-CH(CH3)-O.

[0079] The nature of X and the proportions it occupies in the case of a mixture are generally identical for the one or more compounds of the general formula (III) and for the mixture of compounds comprised in the crosslinker (I).

[0080] For mixtures of the one or more compounds of the general formula (III) and for the compounds (I) comprised in the crosslinker, i and the proportions it occupies in the case of mixtures are generally identical, provided that the i in question is not zero.

[0081] In some embodiments, each i that is not 0 can be independently selected from an integer of 1-50, preferably an integer of 1-30, more preferably an integer of 1-15, more preferably an integer of 1-10, even more preferably an integer of 1-5, and even more preferably an integer of 2-3, and most preferably each i that is not 0 is 2.

[0082] For one or more compounds of the general formula (III) and for the mixture of compounds (I) contained in the crosslinking agent, R 1 The properties of and the proportions they occupy in the case of mixtures are generally the same, provided that the i involved is not zero.

[0083] For the one or more compounds of the general formula (III) and for the mixture of compounds (II) contained in the crosslinking agent, R 1 The properties and proportions of the mixture are usually related to R2 The properties and their ratios are the same, provided that the i involved is equal to 0.

[0084] R 1 Independently selected from C1-C 30 In some embodiments, R 1 It may be a straight chain or branched alkyl, aryl, alkaryl or aralkyl group which may or may not contain a cyclic part.

[0085] In some embodiments, R 1 Can be independently selected from C1-C 20 Hydrocarbyl, preferably C1-C 10 The hydrocarbon group is preferably a C1-C6 hydrocarbon group, and most preferably a C1-C4 hydrocarbon group. In view of its better compatibility with water, a shorter hydrocarbon group is preferred.

[0086] Examples of one or more compounds of the general formula (III) are 2-(2-methoxyethoxy)ethanol, 2-(2-butoxyethoxy)ethanol, dipropylene glycol monomethyl ether and 2-butoxyethanol.

[0087] Typically, the crosslinking agents of the present invention are formaldehyde-free.

[0088] Typically, the mixture of compounds included in the crosslinking agent is also formaldehyde-free.

[0089] The cross-linking agent of the first aspect and the mixture of compounds contained therein include compounds obtainable by reacting one or more compounds of the general formula (II) with one or more compounds of the general formula (III), and may also include unreacted starting materials (e.g., compounds of the general formula (I) in which i in each Q' is equal to 0) that may remain in the reaction medium at the end of the reaction. In some embodiments, at least 70 mol%, preferably at least 80 mol%, more preferably at least 90 mol%, even more preferably at least 95 mol%, and more preferably substantially all of the compounds of the cross-linking agent conform to the general formula (I). The cross-linking agent may be in a liquid medium, that is, it may be in contact with a solvent. For example, it may be suspended, dispersed, or dissolved in a solvent. The solvent preferably includes water, and in this case the cross-linking agent is contained in an aqueous dispersion. This is the subject of the fourth aspect.

[0090] In some embodiments, at least 70 mol%, preferably at least 80 mol%, more preferably at least 90 mol%, more preferably at least 95 mol%, more preferably at least 99 mol%, and most preferably substantially all of the compounds in the mixture of compounds of formula (I) may have at least one Q' group in which i is not 0. In other words, in these embodiments, up to 30 mol%, preferably up to 20 mol%, more preferably up to 10 mol%, more preferably up to 5 mol%, more preferably up to 1 mol%, and most preferably substantially 0 mol% of the compounds in the mixture of compounds of formula (I) have all Q' groups equal to 0. These compounds of formula (I) with all Q' groups equal to 0 are typically unreacted compounds of formula (II).

[0091] In some embodiments, each X can be independently selected from -CH2-CH2-O and -CH2-CH(CH3)-O.

[0092] In some embodiments, for 35 mol% or more of Q' in the mixture, each i can be independently selected from an integer of 1-50, preferably an integer of 1-30, more preferably an integer of 1-15, more preferably an integer of 1-10, even more preferably an integer of 1-5, and even more preferably an integer of 2-3, and for the remaining Q' in the mixture, i is equal to 0.

[0093] In some preferred embodiments, for 50-80 mol% of Q' in the mixture, each i can be independently selected from an integer of 1-50, preferably an integer of 1-30, more preferably an integer of 1-15, more preferably an integer of 1-10, even more preferably an integer of 1-5, and even more preferably an integer of 2-3, and for the remaining Q' in the mixture, i is equal to 0.

[0094] In some more preferred embodiments, for 57-77 mol% of Q' in the mixture, each i can be independently selected from an integer of 1-50, preferably an integer of 1-30, more preferably an integer of 1-15, more preferably an integer of 1-10, even more preferably an integer of 1-5, and even more preferably an integer of 2-3, and for the remaining Q' in the mixture, i is equal to 0.

[0095] In some even more preferred embodiments, for 59-77 mol% of Q' in the mixture, each i can be independently selected from an integer of 1-50, preferably an integer of 1-30, more preferably an integer of 1-15, more preferably an integer of 1-10, even more preferably an integer of 1-5, and even more preferably an integer of 2-3, and for the remaining Q' in the mixture, i is equal to 0.

[0096] In some more preferred embodiments, i may be equal to 1 or 2 for 59-77 mol% of Q' in the mixture, and i is equal to 0 for the remainder of Q' in the mixture.

[0097] In some most preferred embodiments, i may be equal to 2 for 59-77 mol% of Q' in the mixture, and equal to 0 for the remainder of Q' in the mixture.

[0098] In some embodiments, for all three Q' groups, at least 5 mol%, preferably at least 10 mol%, more preferably at least 15 mol%, more preferably at least 20 mol% of the compounds of formula (I) in the mixture have i other than 0, for example an integer selected from 1-50.

[0099] In some embodiments, for all three Q' groups, 5-40 mol%, preferably 10-32 mol%, more preferably 16-26 mol%, more preferably 19-23 mol% and most preferably 20-22 mol% of the compounds of formula (I) in the mixture have i other than 0, for example an integer selected from 1-50.

[0100] In some embodiments, for all three Q' groups, 5-40 mol%, preferably 10-32 mol%, more preferably 16-26 mol%, more preferably 19-23 mol% and most preferably 20-22 mol% of the compounds of formula (I) in the mixture have i selected from an integer of 1-30.

[0101] In some embodiments, for all three Q' groups, 5-40 mol%, preferably 10-32 mol%, more preferably 16-26 mol%, more preferably 19-23 mol% and most preferably 20-22 mol% of the compounds of formula (I) in the mixture have i selected from an integer of 1-15.

[0102] In some embodiments, for all three Q' groups, 5-40 mol%, preferably 10-32 mol%, more preferably 16-26 mol%, more preferably 19-23 mol% and most preferably 20-22 mol% of the compounds of formula (I) in the mixture have i selected from an integer of 1-10.

[0103] In some embodiments, for all three Q' groups, 5-40 mol%, preferably 10-32 mol%, more preferably 16-26 mol%, more preferably 19-23 mol% and most preferably 20-22 mol% of the compounds of formula (I) in the mixture have i selected from an integer of 1-5.

[0104] In some embodiments, for all three Q' groups, 5-40 mol%, preferably 10-32 mol%, more preferably 16-26 mol%, more preferably 19-23 mol% and most preferably 20-22 mol% of the compounds of formula (I) in the mixture have i selected from an integer of 2-3.

[0105] In some embodiments, 5-40 mol%, preferably 10-32 mol%, more preferably 16-26 mol%, more preferably 19-23 mol% and most preferably 20-22 mol% of the compounds of formula (I) in the mixture have i equal to 2 for all three Q' groups.

[0106] Any features of the first aspect may be as described accordingly in the fifth aspect.

[0107] In a second aspect, the present invention relates to a mixture of compounds of general formula (I):

[0108]

[0109] Where Q' is of the formula COO-[X-] i R 1 A group in which:

[0110] For 35 mol% or more of Q' in the mixture, each i is independently selected from an integer of 1 to 50, and for the remainder of Q' in the mixture, i is equal to 0,

[0111] Each X is independently selected from 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, Vin is vinyl, and

[0112] Each R 1 Independently selected from C1-C 30 Hydrocarbon.

[0113] In some embodiments, the composition of the mixture of the second aspect may be the same as the composition of the cross-linking agent of the first aspect.

[0114] Any features of the second aspect may be as described in the first aspect.

[0115] In a third aspect, the present invention relates to a compound of general formula (I):

[0116]

[0117] It is selected from the following compounds:

[0118] a) wherein one of the Q' groups is a group of the formula COOCH2CH2CH2CH3, and wherein two of the Q' groups are a group of the formula COO-[CH2-CH2-O-]2CH3;

[0119] b) wherein one of the Q' groups is a group of the formula COOCH2CH2CH2CH3, and wherein two of the Q' groups are a group of the formula COO-[CH2-CH2-O-]2CH2CH2CH2CH3;

[0120] c) wherein one of the Q' groups is a group of the formula COOCH2CH2CH2CH3, and wherein two of the Q' groups are a group of the formula COO-[CH2-CH(CH3)-O-]2CH3;

[0121] d) wherein one of the Q' groups is a group of the formula COOCH2CH2CH2CH3, and wherein two of the Q' groups are groups of the formula COOCH2CH2OCH2CH2CH2CH3; and

[0122] e) wherein one of the Q' groups is a group of the formula COOCH2CH2CH2CH3, and wherein two of the Q' groups are a group of the formula COO-[CH2-CH2-O-]2CH2CH3.

[0123] In some embodiments, these compounds are examples of individual compounds present in the cross-linker of the first aspect or the mixture of the second aspect.

[0124] In a first preferred embodiment, the present invention relates to a compound of general formula (I):

[0125]

[0126] wherein one of the Q' groups is a group of formula COOCH2CH2CH2CH3, and wherein two of the Q' groups are a group of formula COO-[CH2-CH2-O-]2CH3.

[0127] In a second preferred embodiment, the present invention relates to a compound of general formula (I):

[0128]

[0129] wherein one of the Q' groups is a group of formula COOCH2CH2CH2CH3, and wherein two of the Q' groups are a group of formula COO-[CH2-CH2-O-]2CH2CH2CH2CH3.

[0130] In a third preferred embodiment, the present invention relates to a compound of general formula (I):

[0131]

[0132] wherein one of the Q' groups is a group of formula COOCH2CH2CH2CH3, and wherein two of the Q' groups are a group of formula COO-[CH2-CH(CH3)-O-]2CH3.

[0133] In a fourth preferred embodiment, the present invention relates to a compound of general formula (I):

[0134]

[0135] wherein one of the Q' groups is a group of formula COOCH2CH2CH2CH3, and wherein two of the Q' groups are a group of formula COOCH2CH2OCH2CH2CH2CH3.

[0136] In a fifth preferred embodiment, the present invention relates to a compound of general formula (I):

[0137]

[0138] wherein one of the Q' groups is a group of formula COOCH2CH2CH2CH3, and wherein two of the Q' groups are a group of formula COO-[CH2-CH2-O-]2CH2CH3.

[0139] In a fourth aspect, the present invention relates to an aqueous (coating) composition comprising a crosslinker 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.

[0140] In some embodiments, the aqueous composition may comprise 5-50 wt% water, preferably 10-25 wt% water.

[0141] Preferably, the aqueous composition does not contain any organic solvent. In some embodiments, the aqueous composition may contain 0-10 wt%, preferably 0-4 wt% of a water-miscible organic solvent. These small amounts of organic solvents allow the aqueous composition to still meet the requirements of a low VOC aqueous composition.

[0142] Preferably, the sum of the amount of water and the amount of water-miscible organic solvent does not exceed 50 wt%.

[0143] In some embodiments, the aqueous composition may comprise 5-50 wt% water, and 0-50 wt%, preferably 0-10 wt%, more preferably 0-4 wt% water-miscible organic solvent, wherein the sum of the amount of water and the amount of water-miscible organic solvent does not exceed 50 wt%.

[0144] Preferably, the aqueous composition may comprise 10-25 wt% of water, and 0-10 wt%, preferably 0-4 wt% of a water-miscible organic solvent.

[0145] When present, any water miscible organic solvent is suitable. Preferably, the organic solvent may include a compound having the following general formula:

[0146] X=HO-[-X'-] j -R 3

[0147] Where R 3 Independently selected from C1-C 30 Hydrocarbyl, and preferably with R 1 same.

[0148] X' is independently selected from 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, and is preferably the same as X, wherein Ph is phenyl and Vin is vinyl.

[0149] j is independently selected from integers of 1-50, and is preferably the same as i.

[0150] In some embodiments, the aqueous dispersion may comprise 50-95 wt% of the crosslinker of any embodiment of the first aspect, the mixture of any embodiment of the second aspect, or the compound of any embodiment of the third aspect.

[0151] In some embodiments, the total amount of a) water, b) an optional water-miscible organic solvent, and c) a cross-linking agent of any embodiment of the first aspect, a mixture of any embodiment of the second aspect, or a compound of any embodiment of the third aspect together accounts for at least 90 wt %, preferably at least 95 wt %, more preferably at least 99 wt %, and most preferably substantially all of the aqueous dispersion.

[0152] Any features of the fourth aspect may be as described in the first aspect, the second aspect or the third aspect respectively.

[0153] In a fifth aspect, the present invention relates to a method of forming the crosslinking agent of the first aspect, the mixture of the second aspect or the compound of the third aspect, comprising the step of reacting one or more compounds of the general formula (II) with one or more compounds of the general formula (III) in the absence of a catalyst:

[0154] HO-[X-] i R 1 (III)

[0155] in:

[0156] Q" is COOR 2 A group in which each R 2 Independently selected from C1-C 30 Hydrocarbon,

[0157] Each X is independently selected from 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, Vin is vinyl,

[0158] Each i is independently selected from an integer from 1 to 50, and

[0159] Each R 1 Independently selected from C1-C 30 Hydrocarbon.

[0160] If the one or more compounds of general formula (II) are obtained (e.g. purchased) in the form of being dissolved in an organic solvent, it may be advantageous to remove at least 90 wt%, preferably 95 wt% or more of the solvent before adding the one or more compounds of general formula (III) according to techniques well known to those skilled in the art.

[0161] It is particularly advantageous to perform this preliminary solvent removal step if the compound of formula (III) has a boiling point of 140°C or less.

[0162] In some embodiments, the molar ratio of the compound of formula (II) to the compound of formula (III) may be 1:4.5 to 1:1.5. Preferably, the ratio may be 1:4 to 1:2, more preferably, the ratio may be 1:3.5 to 1:2.5. Most preferably, the ratio is 1:3. Such ratios are advantageous because they have the best self-crosslinking properties and generally give very good water resistance and solvent resistance after co-crosslinking.

[0163] The reaction between the compound of formula (II) and the compound of formula (III) is preferably carried out under an inert atmosphere, such as nitrogen, according to techniques well known to those skilled in the art. The reaction temperature is usually 60-180° C. and the reaction pressure is usually 50-500 mbar.

[0164] The method of the fifth aspect does not require a catalyst. The inventors have even noticed that surprisingly better results are obtained when no catalyst is used.

[0165] At the end of the reaction, water may be added to form an aqueous composition, in particular an aqueous dispersion. Water is preferably added gradually. Water is preferably added until the solid content in the aqueous composition reaches 75-95 wt%.

[0166] In addition to water, a water-miscible organic solvent may be added to bring the final solid content to 40-94 wt%. An example of a suitable water-miscible organic solvent is ethylene glycol monobutyl ether. Adding this solvent may help reduce the viscosity of the dispersion.

[0167] Any features of the fifth aspect may be as described in the first, second or third aspect respectively.

[0168] In a sixth aspect, the present invention relates to a method for forming a coating, comprising reacting a crosslinker 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 an additional compound capable of condensing with the compound of general formula (I) and different from the compound comprising a 1,3,5-triazine carbamate moiety in an amount of 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% relative to the compound of general formula (I). This means that if there are 100 g of the compound of general formula (I) in the reaction medium, no more than 30 g, no more than 25 g, no more than 20 g, no more than 15 g, no more than 10 g, no more than 5 g or even no more than 1 g of a compound capable of condensing with the compound of general formula (I) and different from the compound comprising a 1,3,5-triazine carbamate moiety may be present in the reaction medium.

[0169] Generally, in a sixth aspect, the present invention relates to a method for forming a coating, which comprises reacting a crosslinker of any embodiment of the first aspect, a mixture of any embodiment of the second aspect, or a compound of any embodiment of the third aspect with itself, provided that the reaction is carried out in the presence of an additional compound that does not belong to the compound of general formula (I) but is capable of condensing with the compound of general formula (I) in an amount of 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% relative to the compound of general formula (I).

[0170] In other words, in the sixth aspect, the present invention relates to use of the crosslinking agent of any embodiment of the first aspect, the mixture of any embodiment of the second aspect or the compound of any embodiment of the third aspect for forming a coating by self-crosslinking.

[0171] In some embodiments, the coating may be as described in the seventh aspect below.

[0172] The reaction described in the sixth aspect is a self-crosslinking reaction, that is, a crosslinking reaction between a) the crosslinking agent of any embodiment of the first aspect, the mixture of any embodiment of the second aspect, or the compound of any embodiment of the third aspect and b) itself. The crosslinking agent of any embodiment of the first aspect, the mixture of any embodiment of the second aspect, and the compound of any embodiment of the third aspect all have the property of being able to react with themselves to form a crosslinked network, thereby forming a crosslinked product (usually a film or coating).

[0173] In some embodiments, the self-crosslinking reaction is carried out in the presence of up to 30 wt %, preferably up to 25 wt %, more preferably up to 20 wt %, more preferably up to 15 wt %, more preferably up to 10 wt %, more preferably up to 5 wt %, even more preferably up to 3 wt % or still more preferably up to 1 wt % of an additional compound capable of condensing with the compound of general formula (I) and different from the compound comprising a 1,3,5-triazine carbamate moiety.

[0174] This means that in these embodiments, 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% of compounds not belonging to general formula (I) but capable of condensing with the crosslinking agent, mixture or compound according to general formula (I) (other than the compound comprising a 1,3,5-triazine carbamate moiety) can be present during the reaction. The reason for allowing up to 30 wt% of compounds not belonging to general formula (I) is that in the presence of such a small amount of other reactive compounds, the reaction remains mainly a self-crosslinking reaction.

[0175] Most preferably, the self-crosslinking reaction is carried out in the absence of additional compounds that can condense with the compound of general formula (I) and are different from the compound containing 1,3,5-triazine carbamate moiety. This means that, in these embodiments, the only additional compound allowed to exist during the self-crosslinking reaction is a compound containing 1,3,5-triazine carbamate moiety but not belonging to general formula (I). This also means that, in these embodiments, additional compounds (different from those containing 1,3,5-triazine carbamate moiety) that can condense with the compound of general formula (I) are not allowed to exist during the reaction. This exception is due to the fact that when forming the crosslinking agent of the first aspect, a small amount of by-products containing 1,3,5-triazine carbamate moiety but not belonging to general formula (I) may be formed. The presence of such by-products does not usually significantly interfere with the performance of the crosslinking agent of the first aspect, the mixture of the second aspect, or the compound of the third aspect. In addition, removing such by-products is very time-consuming, energy-consuming and wasteful. Therefore, after the crosslinking agent of the first aspect is synthesized, it is usually not removed from the crosslinking agent.

[0176] In some embodiments, the reacting step may include subjecting the cross-linking agent to a temperature of at least 120° C. or even at least 130° C. For example, the reacting step may include subjecting the cross-linking agent to a temperature of 120-190° C.

[0177] In some embodiments, the additional compound capable of condensing with the compound of formula (I) may have one or more of the following functional groups: aldehyde, hydroxyl, epoxy, carboxyl, and anhydride.

[0178] Any features of the sixth aspect may be as described in the first, second, third or seventh aspect respectively.

[0179] In a seventh aspect, the present invention relates to a coating comprising a crosslinked crosslinker of any embodiment of the first aspect, a crosslinked mixture of any embodiment of the second aspect, or a crosslinked compound of any embodiment of the third aspect, provided that no additional compound different from the compound comprising a 1,3,5-triazine carbamate portion is condensed with the compound of general formula (I), or an amount of at most 30 wt%, preferably at most 25 wt%, more preferably at most 20 wt%, more preferably at most 15 wt%, more preferably at most 10 wt%, more preferably at most 5 wt%, even more preferably at most 3 wt% and even more preferably at most 1 wt% of additional compound different from the compound comprising a 1,3,5-triazine carbamate portion is condensed with the compound of general formula (I).

[0180] Generally, in the seventh aspect, the present invention relates to a coating comprising a crosslinked crosslinker of any embodiment of the first aspect, a crosslinked mixture of any embodiment of the second aspect, or a crosslinked compound of any embodiment of the third aspect, provided that: no additional compounds not belonging to the general formula (I) are condensed with the compound of the general formula (I), or an amount of at most 30wt%, preferably at most 25wt%, more preferably at most 20wt%, more preferably at most 15wt%, more preferably at most 10wt%, more preferably at most 5wt%, even more preferably at most 3wt% and even more preferably at most 1wt% of additional compounds not belonging to the general formula (I) are condensed with the compound of the general formula (I), relative to the amount of the compound of the general formula (I).

[0181] In some embodiments, the coating is capable of withstanding 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 still more preferably at least 200 MEK double rubs when measured according to the test method described in the Examples section.

[0182] In some embodiments, the additional compound capable of condensing with the compound of formula (I) has one or more of the following functional groups: aldehyde, hydroxyl, epoxy, carboxyl, and anhydride.

[0183] Any features of the seventh aspect may be as described in the first, second, third or sixth aspect respectively.

[0184] In an eighth aspect, the present invention relates to a method for co-crosslinking a crosslinking agent of any embodiment of the first aspect, a mixture of any embodiment of the second aspect, or a compound of any embodiment of the third aspect with an additional compound, wherein the method comprises the step of heating the crosslinking agent, the mixture or the compound and the additional compound at a temperature of 100-150°C, or even 110-150°C.

[0185] The cross-linking agent of any embodiment of the first aspect, the mixture of any embodiment of the second aspect, or the compound of any embodiment of the third aspect can be co-cross-linked with a variety of additional compounds. Examples of suitable additional compounds are co-monomers, oligomers and polymers, such as hydroxyl-containing monomers, oligomers and polymers, epoxy-containing monomers, oligomers and polymers, and carboxyl-containing monomers, oligomers and polymers.

[0186] The crosslinker of any embodiment of the first aspect on the one hand, the mixture of any embodiment of the second aspect, or the mixture of any embodiment of the third aspect and an additional compound on the other hand may be included in a coating composition, particularly a low VOC waterborne composition.

[0187] In one advantageous aspect, the additional compound used herein is an acrylic polyol. Exemplary acrylic polyol polymers suitable for use herein include those available from allnex USA, INC under the trade name or Those.

[0188] This co-crosslinking can occur with or without a catalyst, and generally requires heating.

[0189] The resulting coating is generally suitable for protecting the surface.

[0190] Any features of the eighth aspect may be as described in the first, second or third aspect respectively. Example

[0191] The present disclosure is further illustrated by the following examples. These examples are for illustrative purposes only and are not intended to limit the scope of the claims.

[0192] Example 1: Reaction of tris((methyl / butyl)carbamate)triazine and 2-(2-methoxyethoxy)ethanol in a molar ratio of 1:3

[0193] A 500 ml four-necked glass flask equipped with a glass stirrer, thermocouple, distillation bridge and Liebig condenser was charged with 242 g (0.32 mol) of 1,3,5-triazine containing a combination of butyl and methyl carbamate functional groups (present in the form of 50 wt% in butanol, available under the trade name NF2000A is commercially available from allnex). The distillation was performed under a reduced pressure of 100 mbar, and the temperature was gradually increased from 70° C. to 150° C. until the weight of the compound present in the glass flask decreased to 136 g, indicating that the butanol solvent was almost completely removed.

[0194] The flask and its contents were then returned to atmospheric pressure under nitrogen and cooled to 100°C. 118 g (0.98 mol) of 2-(2-methoxyethoxy)ethanol was then mixed with the 1,3,5-triazine. The temperature of the reaction mixture was gradually raised under atmospheric pressure and nitrogen and maintained at 120-130°C for 30 minutes to promote the exchange of the alkyl chains on the 1,3,5-triazine by 2-(2-methoxyethoxy)ethanol. The vacuum was then gradually increased from 350 mbar to 80 mbar under nitrogen and the temperature was then gradually increased to 150°C. The reaction was maintained at 80 mbar and 150°C with stirring until no condensation of distillate was observed, thereby obtaining 173 g of the final product. After all the solvents were distilled off, the reaction temperature was lowered to 80°C and 48 g of water was gradually added to obtain a 78 wt% adduct in water.

[0195] From the C NMR, about 65 mol% replacement of the alkylated species was achieved (an average of 2 2-(2-methoxyethoxy)ethylcarbamate functional groups per triazine molecule).

[0196] A similar degree of substitution (64 mol %) was confirmed by LC-MS. Furthermore, LC-MS allowed the proportion of tris(2-(2-methoxyethoxy)ethylcarbamate) in the triazine to be estimated to be 21 mol %.

[0197] Example 2: Reaction of tris((methyl / butyl)carbamate)triazine and 2-(2-methoxyethoxy)ethanol in a molar ratio of 1:4.5

[0198] 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 1,3,5-triazine containing a combination of butyl and methyl carbamate functional groups (present in the form of 50 wt% in butanol, available under the trade name NF2000A is commercially available from allnex). The distillation was performed under a reduced pressure of 100 mbar, and the temperature was gradually increased from 70° C. to 150° C. until the weight of the compound present in the glass flask decreased to 113 g, indicating that the butanol solvent was almost completely removed.

[0199] The flask and its contents were then returned to atmospheric pressure under a nitrogen atmosphere and cooled to 100°C. 147 g (1.22 mol) of 2-(2-methoxyethoxy)ethanol was then mixed with the 1,3,5-triazine. The temperature of the reaction mixture was gradually raised under atmospheric pressure and nitrogen atmosphere and maintained at 120-130°C for 30 minutes to promote the exchange of the alkyl chains on the 1,3,5-triazine by 2-(2-methoxyethoxy)ethanol. The vacuum was then gradually increased from 350 mbar to 80 mbar under a nitrogen atmosphere, and the temperature was then gradually increased to 150°C. The reaction was maintained at 80 mbar and 150°C with stirring until no condensation of distillate was observed, thereby obtaining 150 g of the final product. After all the solvents were distilled off, the reaction temperature was lowered to 80°C and 36 g of water was gradually added to obtain 81 wt% adduct in water.

[0200] From the C NMR, about 77 mol% replacement of the alkylated species was achieved (an average of 2.3 2-(2-methoxyethoxy)ethylcarbamate functional groups per triazine molecule).

[0201] A similar degree of substitution (76 mol %) was confirmed by LC-MS. Furthermore, LC-MS allowed the proportion of tris(2-(2-methoxyethoxy)ethylcarbamate) in the triazine to be estimated to be 39 mol %.

[0202] Example 3: Reaction of tris((methyl / butyl)carbamate)triazine and 2-(2-methoxyethoxy)ethanol in a molar ratio of 1:1.5

[0203] A 500 ml four-necked glass flask equipped with a glass stirrer, a thermocouple, a distillation bridge and a Liebig condenser was charged with 270 g (0.37 mol) of 1,3,5-triazine containing a combination of butyl and methyl carbamate functional groups (present in the form of 50 wt% in butanol, available under the trade name NF2000A is commercially available from allnex). The distillation was performed under a reduced pressure of 100 mbar, and the temperature was gradually increased from 70° C. to 150° C. until the weight of the compound present in the glass flask decreased to 145.1 g, indicating that the butanol solvent was almost completely removed.

[0204] The flask and its contents were then returned to atmospheric pressure under a nitrogen atmosphere and cooled to 100°C. 66 g (0.55 mol) of 2-(2-methoxyethoxy)ethanol was then mixed with the 1,3,5-triazine. The temperature of the reaction mixture was gradually raised under atmospheric pressure and nitrogen atmosphere and maintained at 120-130°C for 30 minutes to promote the exchange of the alkyl chains on the 1,3,5-triazine by 2-(2-methoxyethoxy)ethanol. The vacuum was then gradually raised from 350 mbar to 80 mbar under a nitrogen atmosphere, and the temperature was then gradually raised to 150°C.

[0205] The reaction was maintained at 80 mbar and 150° C. with stirring until no more condensation of distillate was observed, yielding 180 g of final product. After all solvent had been distilled off, the reaction temperature was lowered to 80° C. and 10 g of water were added gradually. To further reduce the viscosity, 31 g of 2-butoxyethanol solvent was added, yielding 80 wt% solid adduct in water.

[0206] From the C NMR, about 39 mol% replacement of the alkylated species was achieved (an average of 1.17 2-(2-methoxyethoxy)ethylcarbamate functional groups per triazine molecule).

[0207] A similar degree of substitution (39 mol %) was confirmed by LC-MS. Furthermore, LC-MS allowed the proportion of tris(2-(2-methoxyethoxy)ethylcarbamate) in the triazine to be estimated to be 5 mol %.

[0208] The chemical compositions of the crosslinking agents of Examples 1-3 are summarized in Table 1 below.

[0209] Table 1: Chemical composition of the crosslinking agents of Examples 1-3

[0210]

[0211] Example 4: Reaction of tris((methyl / butyl)carbamate)triazine and 2-butoxyethanol in a molar ratio of 1:3

[0212] A 500 ml four-necked glass flask equipped with a glass stirrer, a thermocouple, a distillation bridge and a Liebig condenser was charged with 270 g (0.37 mol) of 1,3,5-triazine containing a combination of butyl and methyl carbamate functional groups (present in the form of 50 wt% in butanol, available under the trade name NF2000A is commercially available from allnex). The distillation was performed under a reduced pressure of 100 mbar, and the temperature was gradually increased from 70° C. to 150° C. until the weight of the compound present in the glass flask decreased to 145.1 g, indicating that butanol was almost completely removed.

[0213] The flask and its contents were then returned to atmospheric pressure under a nitrogen atmosphere and cooled to 100°C. 116 g (0.98 mol) of 2-butoxyethanol was then mixed with the 1,3,5-triazine. The temperature of the reaction mixture was gradually raised under atmospheric pressure and nitrogen atmosphere and maintained at 120-130°C for 30 minutes to promote the exchange of the alkyl chains on the 1,3,5-triazine by 2-butoxyethanol. The vacuum was then gradually increased from 350 mbar to 80 mbar under a nitrogen atmosphere, and the temperature was then gradually increased to 150°C. The reaction was maintained at 80 mbar and 150°C under stirring until no condensation of the distillate was observed, thereby obtaining 165 g of the final product. After all the solvents were distilled off, the reaction temperature was lowered to 80°C and 9 g of water was slowly added. In order to further reduce the viscosity, 40 g of 2-butoxyethanol was added to obtain a 77 wt% adduct in water and 2-butoxyethanol.

[0214] From the C NMR, about 53 mol % replacement of the alkylated species was achieved (an average of 1.59 2-butoxyethylcarbamate functional groups per triazine molecule).

[0215] Example 5: Reaction of tris((methyl / butyl)carbamate)triazine and 2-(2-butoxyethoxy)ethanol in a molar ratio of 1:3 in a single distillation step

[0216] 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 butyl and methyl carbamate functional groups (present in the form of 50 wt% in butanol, available under the trade name NF2000A is commercially available from allnex). Then 147 g (0.91 mol) of 2-(2-butoxyethoxy)ethanol was mixed with the 1,3,5-triazine. The temperature of the reaction mixture was gradually raised to 80° C. under a nitrogen atmosphere. Then, the reaction mixture was slowly decompressed to 80 mbar under a nitrogen atmosphere while the temperature was raised from 80° C. to 150° C., thereby performing distillation and reaction simultaneously.

[0217] The temperature was then maintained at 150° C., the pressure was 80 mbar, and stirring was performed until no condensation of the distillate was 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 gradually added, thereby obtaining a 73 wt % adduct in water and 2-butoxyethanol.

[0218] From the C NMR, about 63 mol% replacement of the alkylated species was achieved (an average of 1.89 2-(2-butoxyethoxy)ethylcarbamate functional groups per triazine molecule).

[0219] A similar degree of substitution (61 mol %) was confirmed by LC-MS. Furthermore, LC-MS allowed the proportion of tris(2-(2-butoxyethoxy)ethylcarbamate) in the triazine to be estimated to be 30 mol %.

[0220] Example 6: Reaction of tris((methyl / butyl)carbamate)triazine and dipropylene glycol monomethyl ether in a molar ratio of 1:3 in a single distillation step

[0221] A 500 ml four-necked glass flask equipped with a glass stirrer, a thermocouple, a distillation bridge and a Liebig condenser was charged with 221 g (0.30 mol) of 1,3,5-triazine containing a combination of butyl and methyl carbamate functional groups (present in the form of 50 wt% in butanol, available under the trade name NF2000A is commercially available from allnex). Then 132.8 g (0.90 mol) of dipropylene glycol monomethyl ether (commercially available under the trade name DOWANOLTM 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 depressurized to 80 mbar under a nitrogen atmosphere while the temperature was raised from 80°C to 150°C, thereby simultaneously performing distillation and reaction. The temperature was then maintained at 150°C and the pressure was 80 mbar with stirring until no more condensation of the distillate was observed, thereby obtaining 147 g of the final product. After all the solvents had been distilled off, the reaction temperature was lowered to 80°C and 9 g of water was gradually added. In order to further reduce the viscosity, 48.5 g of 2-butoxyethanol was gradually added to obtain a 72 wt% adduct in water and 2-butoxyethanol.

[0222] From the C NMR, approximately 40 mol% replacement of the alkylated species was achieved (an average of 1.21 dipropylene glycol monomethyl ether carbamate functional groups per triazine molecule).

[0223] Example 7: Aqueous composition

[0224] All crosslinking agents of Examples 1-6 can obtain aqueous compositions. In addition, all crosslinking agents of the present invention show excellent water dispersibility. The crosslinking agents of Examples 1 and 2 do not require any additional organic solvent to achieve good miscibility in water. A certain amount of organic solvent is beneficial for the crosslinking agents of Examples 3-6 to achieve good miscibility in water.

[0225] Example 8: Self-crosslinking performance

[0226] The crosslinking agents and the like of the present invention were evaluated by forming a coating on a metal plate and then heating the coating at 140°C for 30 minutes. Self-crosslinking properties of NF2000A (triazine as control). All films obtained were transparent. No catalyst was used in the self-crosslinking studies.

[0227] Solvent resistance (methyl ethyl ketone double rub on metal) was evaluated as follows: a cotton cloth saturated with methyl ethyl ketone was pressed onto the coated surface in a reciprocating motion; one double rub equals one reciprocating motion across the coated surface. The reported number is the number of double rubs required to destroy the coating. High solvent resistance helps ensure good protection of the coating and substrate from spills of any household or industrial products.

[0228] From these studies it can be concluded that the comparative tris((methyl / butyl)carbamate)triazine ( NF2000A) does not self-crosslink, while the crosslinker of the present invention does self-crosslink. The crosslinkers obtained in all the examples of the present invention show excellent self-crosslinking performance, which is manifested in that they have the ability to withstand at least 75, at least 100, at least 150 or even at least 200 methyl ethyl ketone two-way rubbings. Compared with the crosslinker that fails before 40 methyl ethyl ketone two-way rubbings, the crosslinker of the present invention is not self-crosslinking. All other examples of the crosslinking agent of the present invention showed better self-crosslinking performance and higher resistance to two-way rubbing of methyl ethyl ketone compared to the NF2000A control.

[0229] The results are summarized in Table 2 below.

[0230] Table 2: Self-crosslinking properties

[0231]

[0232] Example 9: Co-crosslinking in low VOC formulations

[0233] Although the control tris((methyl / butyl)carbamate) triazine NF2000A has many beneficial properties, but it is not soluble in water. It can be used in water-reducible resins and water-based dispersions, but this requires first blending with the resin to be crosslinked and then adding a water-compatible organic solvent. However, this process does not always result in a stable water-based formulation. In addition, the VOC (volatile organic compound) content of the resulting formulation is relatively high.

[0234] In contrast, the crosslinking agents of the present invention are generally water-based, or do not require much organic solvent to form a clear and stable composition. For water-based compositions, less than 2 wt% of organic solvent is generally used. Otherwise, no more than 15 wt% of organic solvent is sufficient to make it compatible with water.

[0235] Since these crosslinkers contribute little to the volatile organic components (VOC) in coating formulations, they are Compared with the formulations prepared with NF2000A and binders, the VOC of the formulations prepared with the crosslinker of the present invention and typical water-based binders (especially waterborne acrylic resins) is significantly reduced.

[0236] The coating is formed on a metal plate and then heated at 115-140°C for 30 minutes. NF2000A and the crosslinking agent of the present invention are combined with a waterborne acrylic resin (available from Allnex under the trade name The co-crosslinking performance of 6276 (commercially available) was evaluated. All films obtained were transparent. No catalyst was used in the co-crosslinking study.

[0237] Low VOC formulations are available, but it is important to note that polymer binders 6276 contains 3.2 wt% organic solvents, which necessarily increases the overall VOC value. Table 3 below shows the VOC results (in g / L) and the methyl ethyl ketone two-way rub results.

[0238] Table 3: Co-crosslinking properties and VOC values

[0239]

[0240] It can be easily observed from Table 3 that the crosslinking agent of the present invention is compatible with the exemplary waterborne acrylic resin. The co-crosslinking performance of 6276 The co-crosslinking performance of the NF2000A control was comparable.

[0241] These co-crosslinking experiments have been repeated on glass and paperboard (rather than metal). Good MEK two-way rub performance was also obtained on these substrates.

Claims

1. A crosslinking agent obtainable by reacting one or more compounds of the following general formula (II) with one or more compounds of the following general formula (III): HO-[X-] i R 1 (III) in: Each Q" is the formula COOR 2 A group in which each R 2 Independently selected from C1-C 30 Hydrocarbon, Each X is independently selected from 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, Vin is vinyl, Each i is independently selected from an integer of 1-50, Each R 1 Independently selected from C1-C 30 Hydrocarbon, The crosslinking agent comprises a mixture of compounds of the following general formula (I): Where Q' is of the formula COO-[X-] i R 1 A group in which: For 35 mol% or more of Q' in the mixture, each i is independently selected from an integer of 1 to 50, and for the remainder of Q' in the mixture, i is equal to 0, Each X is independently selected from 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, Vin is vinyl, and Each R 1 Independently selected from C1-C 30 Hydrocarbon. 2 . The crosslinker according to claim 1 , wherein at least 70 mol % of the compounds in the mixture have at least one Q′ group where i is not 0. 3 .

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

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

5. The cross-linking agent of any one of the preceding claims, wherein each X is independently selected from -CH2-CH2-O and -CH2-CH(CH3)-O.

6. A cross-linking agent according to any one of the preceding claims, wherein R 1 Independently selected from C1-C4 hydrocarbon groups.

7. The crosslinker according to any one of the preceding claims, wherein at least 5 mol% of the compounds of formula (I) in the mixture have i selected from an integer of 1-50 for all three Q' groups.

8. An aqueous composition comprising the cross-linking agent according to any one of claims 1 to 7.

9. A method for forming a cross-linking agent according to any one of claims 1 to 7, comprising the step of reacting one or more compounds of the following general formula (II) with one or more compounds of the following general formula (III) in the absence of a catalyst: HO-[X-] i R 1 (III) in: Q" is COOR 2 A group in which each R 2 Independently selected from C1-C 30 Hydrocarbon, Each X is independently selected from 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, Vin is vinyl, Each i is independently selected from an integer of 1-50, Each R 1 Independently selected from C1-C 30 Hydrocarbon.

10. A method of forming a coating comprising the step of reacting a crosslinking agent as claimed in any one of claims 1 to 7 with itself, provided that the reaction is carried out in the presence of up to 30 wt% of an additional compound capable of condensing with the compound of general formula (I) and different from the compound comprising a 1,3,5-triazine carbamate moiety, wherein the wt% is relative to the amount of the compound of general formula (I).

11. The method according to claim 10, wherein the additional compound capable of condensing with the compound of general formula (I) has one or more of the following functional groups: aldehyde, hydroxyl, epoxy, carboxyl and anhydride.

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

13. A coating comprising a crosslinking agent according to any one of claims 1 to 7, provided that no additional 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 wt% of additional compounds other than the compound comprising a 1,3,5-triazine carbamate moiety are condensed with the compound of general formula (I), wherein the wt% is relative to the amount of the compound of general formula (I).

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

15. A compound of the following general formula (I): It is selected from the following compounds: a) wherein one of the Q' groups is a group of the formula COOCH2CH2CH2CH3, and wherein two of the Q' groups are a group of the formula COO-[CH2-CH2-O-]2CH3; b) wherein one of the Q' groups is a group of the formula COOCH2CH2CH2CH3, and wherein two of the Q' groups are a group of the formula COO-[CH2-CH2-O-]2CH2CH2CH2CH3; c) wherein one of the Q' groups is a group of the formula COOCH2CH2CH2CH3, and wherein two of the Q' groups are a group of the formula COO-[CH2-CH(CH3)-O-]2CH3; d) wherein one of the Q' groups is a group of the formula COOCH2CH2CH2CH3, and wherein two of the Q' groups are groups of the formula COOCH2CH2OCH2CH2CH2CH3; and e) wherein one of the Q' groups is a group of the formula COOCH2CH2CH2CH3, and wherein two of the Q' groups are a group of the formula COO-[CH2-CH2-O-]2CH2CH3.

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