A one component water borne coating composition

Abstract

The present invention relates to a one component water borne coating composition, comprising at least one hydrazide terminated polyisocyanate with the general Formula (I), wherein R1 is independently selected from a residue left after the isocyanate functional group on a polyisocyanate have reacted with a functional group containing an active hydrogen, n is a number from 2.0 to less than or equal to 6.0, m is an integer from 1 to 3, X is independently selected from - NR4NH-, -NR4NHCO- or a heteroatom such as O or S, R3 is independently selected from a straight or branched, saturated or unsaturated, substituted or unsubstituted, aliphatic group with up to 18 carbon atoms or a substituted or unsubstituted aromatic group with 6 to 18 carbon atoms, and wherein when X is O or S there is no R2 and wherein when X is -NR4NH- then there is no R2 and no R3 and -NR4NH- is connected via the nitrogen atom of NH to the carbonyl atom of the terminal carbonylhydrazide and R4 is H or a straight or branched, saturated or unsaturated, substituted or unsubstituted, aliphatic group with up to (18) carbon atoms or a substituted or unsubstituted aromatic group with (6) to (18) carbon atoms and wherein when X is -NR4NHCO- then there is no R2 and - NR4NHCO- is connected via the carbon atom of CO- to R3 and R4 is H or a straight or branched, saturated or unsaturated, substituted or unsubstituted, aliphatic group with up to (18) carbon atoms or a substituted or unsubstituted aromatic group with (6) to (18) carbon atoms and further comprising at least one modified resin containing at least one poly methane or poly aery lie or polymethane acrylic structure and comprising at least one keto structure.

Description

[0001] A one component water borne coating composition

[0002] Technical field

[0003] The present invention relates to a one component water borne coating composition which has a special structure can be used in waterborne acrylic and acrylic modification polyurethane. This structure can help the resin cure at room temperature while keeping very good performance.

[0004] Prior art

[0005] Due to environmental reasons, replacing solvent based products with water-based products has become a common trend around the world in recent years.

[0006] In traditional polyacrylate (PA) and polyurethane acrylate (PUA) self-crosslinking systems, diacetone acrylamide (DAAM) / acetylacetoxyethyl methacrylate (AAEM) with adipic dihydrazide (ADH) systems are generally selected. However, this methods still difficult to achieve the goal of replacing solvent based by water borne products. The main reason is that the final dry film crosslinking density and molecular weights is not sufficient. The typical water borne products contain between 40 and 70 % water, with molecular weights ranging from several hundred thousand to several million. However, most traditional solvent based resins have molecular weights ranging from hundred thousand to less than ten thousand. Low molecular weights easy to get good film formation and high crosslink density.

[0007] For aqueous products, increasing cross-linking density during the polymerization process is extremely difficult and dangerous. Therefore, in the most of waterborne products, the crosslinking system choose DAAM-ADH or AAEM-ADH, the crosslinking process occurs during the drying process, this method have no impact to the emulsion stability. For example, CN109627858A uses AAEM-ADH self-crosslinking method. As described in patent CN109867743 A, a room temperature self-crosslinking waterborne acrylic dispersion use DAAM-ADH as crosslinker. The crosslinking density formed by these methods still very low, so in IK self-crosslinking system, The film performance still difficult to reach the level of traditional solvent based products.

[0008] Water based 2K resins have emerged as the times require. Although many 2K products performance can comparable to solvent based products, their application has numerous limitations. One of the reason is that raw materials with hydroxyl groups must be introduced into polymer chain during in the polymerization process. Due to stronger hydrophilicity, it is difficult to get a hydroxyl value above 3%, which limits the later crosslinking density and performance. For hydroxyl value more than 3% the currently used method is to use SAD (secondary dispersion) technology. However, secondary dispersions are generally synthesized in solvent at normal pressure or high pressure, and then dispersed in water. At the end of the synthesis process, the solvent will be keep in the emulsion or removed. If keeping in the resin, it is often referred to as a "pseudo aqueous" system. Extracting solvents requires additional time and energy by vacuum distillation. To ensure that the solvents used in the first step can be completely eliminated or meet the requirements below a certain set value range, the process is lengthy and complex, and each step may lead to product problems or performance change.

[0009] Further, after obtaining the required hydroxyl value resin, a polyisocyanate crosslinker is required for the curing process. The main problem with this method is that the isocyanate group can also react with water in emulsion. After adding the polyisocyanate crosslinker to the resin, it is necessary to consider the issue of pot life. Generally, the pot life is between 1-8 hours, this means the materials must be fully used within the pot life, otherwise the remaining material will not be usable anymore, resulting in significant waste. Secondly, because some isocyanates will react with water and other side reaction, NCO / OH usually requires an excess of 10% to 100%, so, the molar ratio or equivalent ratio of NCO / OH is between 1.1 and 2.0 to ensure the desired performance. As described in patent CN113248999 A, the two-component topcoat use an equivalent ratio of n (-NCO): n (- OH)=1.5-1.8.

[0010] The crosslinking mechanism of 2K resin, no matter it is hydroxy polyurethane or hydroxy acrylic, or a mixture of both, is the reaction of NCO group with hydroxyl group resulting in a urethane group will ultimately be obtained. There are many similar patents, such as CN108410343A, which choose the way -NCO react with the mixture of waterborne hydroxy acrylic and waterborne polyurethane. Currently, because the high price of polyisocyanate crosslinker, the need for excessive use have led to the higher cost of traditional 2K water-based products.

[0011] CN109337034A describes polyisocyanates, ADH, DAAM, and AAEM in a traditional of involving the ketohydrazide reaction of AAEM and ADH, the Michael addition reaction of DAAM and primary amines, and polymerization using primary aminated DAAM and polyisocyanates, the reaction of small molecule polyols and polyisocyanates with multi-functional groups, and the reaction of aminosiloxanes and polyisocyanates. Disadvantages are that the stability of the modified polyisocyanates is not good enough.

[0012] CN 112538128 A introduces an acrylic monomers which containing urea and hydrazide groups into the polymer chain. However, the compatibility of the ADH modified polyisocyanates with emulsion is not as good as just ADH / AAEM. In CN106149381A, there are monomeric diisocyanates and hydrazides on the polymer chain. Itrefers to cross-linking between the two resins and uses dihydrazides as a chain extender to obtain a hydrazides blocked polyurethane prepolymer, followed by emulsifying this prepolymer containing hydrazide groups into the water to get water-borne polyurethane dispersion.

[0013] Summary of invention

[0014] The object of the present invention was to provide a waterborne resin composition as replacement for traditional two-component (2K) water-based resins while maintaining their good properties of the obtained coatings and improved pot-life and low temperature curing.

[0015] Surprisingly, this purpose has been achieved by providing a one component water borne coating composition, comprising at least one hydrazide terminated polyisocyanate with the general Formula (I), Formula (I), wherein R1is independently selected from a residue left after the isocyanate functional group on a polyisocyanate have reacted with a functional group containing an active hydrogen, n is a number from 2.0 to less than or equal to 6.0, m is an integer from 1 to 3,

[0016] X is independently selected from -NR4NH-, -NR4NHCO- or a heteroatom such as O or S, R3is independently selected from a straight or branched, saturated or unsaturated, substituted or unsubstituted, aliphatic group with up to 18 carbon atoms or a substituted or unsubstituted aromatic group with 6 to 18 carbon atoms, and wherein when X is O or S there is no R2and wherein when X is -NR4NH- then there is no R2and no R3and -NR4NH- is connected via the nitrogen atom of NH to the carbonyl atom of the terminal carbonylhydrazide and R4is H or a straight or branched, saturated or unsaturated, substituted or unsubstituted, aliphatic group with up to 18 carbon atoms or a substituted or unsubstituted aromatic group with 6 to 18 carbon atoms and wherein when X is -NR4NHCO- then there is no R2and -NR4NHCO- is connected via the carbon atom of CO- to R3and R4is H or a straight or branched, saturated or unsaturated, substituted or unsubstituted, aliphatic group with up to 18 carbon atoms or a substituted or unsubstituted aromatic group with 6 to 18 carbon atoms and further comprising at least one modified resin containing at least one polyurethane or polyacrylic or polyurethane acrylic structure and comprising at least one keto structure.

[0017] One aspect of the present invention provides a process for preparing a one component water borne coating composition, wherein at least one hydrazide terminated polyisocyanate with the general Formula (I) is mixed with and / or prepared in the presence of at least one modified resin containing at least one polyurethane or polyacrylic or polyurethane acrylic structure and comprising at least one keto structure.

[0018] Yet another aspect of the present invention provides a use of the inventive one component water borne coating composition for protecting a surface of a substrate or preparing a coating on the surface of a substrate or for an adhesive or for a sealing or for a molded article.

[0019] Yet another aspect of the present invention provides a coating method comprising the steps of: applying the inventive one component water borne coating composition or applying the one component water borne coating composition, obtainable or obtained by the inventive process onto a surface of a substrate, and then curing and drying, optionally under the influence of heat.

[0020] Yet another aspect of the present invention provides a coating obtainable or obtained, preferably directly obtained by the inventive coating method.

[0021] Yet another aspect of the present invention provides a coated product comprising a substrate and a coating obtainable or obtained, preferably directly obtained, according to the inventive coating method or by applying the inventive one component water borne coating composition onto the substrate and then curing and drying, optionally under the influence of heat, wherein the coated product is preferably selected from building walls, furniture surfaces, floors or metal surfaces.

[0022] Embodiments

[0023] The present invention provides a one component water borne coating composition, comprising at least one hydrazide terminated polyisocyanate with the general Formula (I), Formula (I), wherein R1is independently selected from a residue left after the isocyanate functional group on a polyisocyanate have reacted with a functional group containing an active hydrogen, n is a number from 2.0 to less than or equal to 6.0, m is an integer from 1 to 3,

[0024] X is independently selected from -NR4NH-, -NR4NHCO- or a heteroatom such as O or S,

[0025] R3is independently selected from a straight or branched, saturated or unsaturated, substituted or unsubstituted, aliphatic group with up to 18 carbon atoms or a substituted or unsubstituted aromatic group with 6 to 18 carbon atoms, and wherein when X is O or S there is no R2and wherein when X is -NR4NH- then there is no R2and no R3and -NR4NH- is connected via the nitrogen atom of NH to the carbonyl atom of the terminal carbonylhydrazide and R4is H or a straight or branched, saturated or unsaturated, substituted or unsubstituted, aliphatic group with up to 18 carbon atoms or a substituted or unsubstituted aromatic group with 6 to 18 carbon atoms and wherein when X is -NR4NHCO- then there is no R2and -NR4NHCO- is connected via the carbon atom of CO- to R3and R4is H or a straight or branched, saturated or unsaturated, substituted or unsubstituted, aliphatic group with up to 18 carbon atoms or a substituted or unsubstituted aromatic group with 6 to 18 carbon atoms and further comprising at least one modified resin containing at least one polyurethane or poly aery lie or polyurethane acrylic structure and comprising at least one keto structure.

[0026] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

[0027] When the definitions of terms in this specification conflict with the meanings commonly understood by those skilled in the art to which the invention belongs, the definitions set forth herein shall prevail.

[0028] Unless otherwise specified, all numerical values for expressions, reaction conditions, etc. used in the specification and claims are understood to be modified by the term "about". Therefore, unless otherwise indicated, the numerical parameters described herein are approximate values that can vary to obtain the desired performance as needed.

[0029] Unless otherwise specified, the terms "one", "one kind", "a", and "the" used in this specification are intended to include "at least one" or "one or more." For example, "one component" refers to one or more components, and therefore in the implementation of the disclosed embodiment, it may consider and use more than one component.

[0030] The term "and / or" used in this invention refers to either one or both of the elements mentioned. The terms "comprise" and "contain" used in this invention encompass the case where only the mentioned elements are present, as well as the case where other elements not mentioned also exist.

[0031] Hydrazine terminated polyisocyanate with the general Formula (I):

[0032] In another preferred embodiment the present invention provides the coating composition, wherein in general Formula (I) above, the polyisocyanate in R1include one or more of the following structures: diisocyanate dimer structure, isocyanurate structure, allophanate structure, uretdione structure, biuret structure, carbodiimide structure and triazine structure.

[0033] In another preferred embodiment the present invention provides the coating composition, wherein in general Formula (I) above, the polyisocyanate in R1include one or more of a polyisocyanate based on hexamethylene diisocyanate with isocyanurate structure, a polyisocyanate based on pentamethylene diisocyanate with an isocyanurate structure, a polyisocyanate based on isophorone diisocyanate with an isocyanurate structure and a polyisocyanate based on 4,4’ -diisocyanate diphenylmethane with an isocyanurate structure.

[0034] In another preferred embodiment the present invention provides a hydrazide terminated polyisocyanate with the general Formula (I), wherein n is a number from 2.0 to less than or equal to 5.0.

[0035] In another preferred embodiment the present invention provides a hydrazide terminated polyisocyanate with the general Formula (I), wherein m is an integer from 1 to 2.

[0036] In another preferred embodiment the present invention provides a hydrazide terminated polyisocyanate with the general Formula (I), wherein R3is independently selected from a straight or branched, saturated or unsaturated, substituted or unsubstituted, aliphatic group with up to 10 carbon atoms or a substituted or unsubstituted aromatic group with 6 to 10 carbon atoms, most preferred independently selected from a straight or branched, saturated or unsaturated, substituted or unsubstituted, aliphatic group with up to 8 carbon atoms or a substituted or unsubstituted aromatic group with 6 to 10 carbon atoms.

[0037] In another preferred embodiment the present invention provides a hydrazide terminated polyisocyanate with the general Formula (I), wherein R1is independently selected from a residue left after the isocyanate functional group on the polyisocyanate have reacted with a functional group containing an active hydrogen. In another preferred embodiment the present invention provides a hydrazide terminated polyisocyanate with the general Formula (I), wherein when X is -NR2NHCO- then there is no R2and -NR4NHCO- is connected via the carbon atom of CO- to R3and R4is H or a straight or branched, saturated or unsaturated, substituted or unsubstituted, aliphatic group with up to 18 carbon atoms or a substituted or unsubstituted aromatic group with 6 to 18 carbon atoms, preferred there is no R2and -NR4NHCO- is connected via the carbon atom of CO- to R3and R4is H or a straight or branched, saturated or unsaturated, substituted or unsubstituted, aliphatic group with up to 10 carbon atoms or a substituted or unsubstituted aromatic group with 6 to 10 carbon atoms, more preferred there is no R2and -NR4NHCO- is connected via the carbon atom of CO- to R3and R4is H or a straight or branched, saturated or unsaturated, substituted or unsubstituted, aliphatic group with up to 8 carbon atoms or a substituted or unsubstituted aromatic group with 6 to 10 carbon atoms.

[0038] In another preferred embodiment the present invention provides a hydrazide terminated polyisocyanate with the general Formula (I), wherein when X is -NR4NH- then there is no R2and no R3and -NR4NH- is connected via the nitrogen atom of NH to the carbonyl atom of the terminal carbonylhydrazide and R4is H or a straight or branched, saturated or unsaturated, substituted or unsubstituted, aliphatic group with up to 18 carbon atoms or a substituted or unsubstituted aromatic group with 6 to 18 carbon atoms, preferred there is no R2and no R3and -NR4NH- is connected via the nitrogen atom of NH to the carbonyl atom of the terminal carbonylhydrazide and R4is H or a straight or branched, saturated or unsaturated, substituted or unsubstituted, aliphatic group with up to 10 carbon atoms or a substituted or unsubstituted aromatic group with 6 to 10 carbon atoms, more preferred there is no R2and no R3and -NR4NH- is connected via the nitrogen atom of NH to the carbonyl atom of the terminal carbonylhydrazide and R4is H or a straight or branched, saturated or unsaturated, substituted or unsubstituted, aliphatic group with up to 8 carbon atoms or a substituted or unsubstituted aromatic group with 6 to 10 carbon atoms.

[0039] In another preferred embodiment the present invention provides the coating composition, wherein in general Formula (I),

[0040] R1is independently selected from a residue left after the isocyanate functional group on a polyisocyanate have reacted with a functional group containing an active hydrogen, n is a number from 2.0 to less or equal to 6.0, preferred is a number from 2.0 to less or equal to 5.0, m is an integer from 1 to 3, preferred is an integer from 1 to 2,

[0041] X is independently selected from -NR4NH-, -NR4NHCO- or a heteroatom such as O or S,

[0042] R3is independently selected from a straight or branched, saturated or unsaturated, substituted or unsubstituted, aliphatic group with up to 18 carbon atoms or a substituted or unsubstituted aromatic group with 6 to 18 carbon atoms, preferred with up to 10 carbon atoms or a substituted or unsubstituted aromatic group with 6 to 10 carbon atoms, most preferred with up to 8 carbon atoms or a substituted or unsubstituted aromatic group with 6 to 10 carbon atoms, and wherein when X is O or S there is no R2and wherein when X is -NR4NH- then there is no R2and no R3and -NR4NH- is connected via the nitrogen atom of NH to the carbonyl atom of the terminal carbonylhydrazide and R4is H or a straight or branched, saturated or unsaturated, substituted or unsubstituted, aliphatic group with up to 10 carbon atoms or a substituted or unsubstituted aromatic group with 6 to 10 carbon atoms, more preferred there is no R2and no R3and -NR4NH- is connected via the nitrogen atom of NH to the carbonyl atom of the terminal carbonylhydrazide and R4is H or a straight or branched, saturated or unsaturated, substituted or unsubstituted, aliphatic group with up to 8 carbon atoms or a substituted or unsubstituted aromatic group with 6 to 10 carbon atoms and wherein when X is -NR2NHCO- then there is no R2and -NR4NHCO- is connected via the carbon atom of CO- to R3and R4is H or a straight or branched, saturated or unsaturated, substituted or unsubstituted, aliphatic group with up to 18 carbon atoms or a substituted or unsubstituted aromatic group with 6 to 18 carbon atoms, preferred there is no R2and -NR4NHCO- is connected via the carbon atom of CO- to R3and R4is H or a straight or branched, saturated or unsaturated, substituted or unsubstituted, aliphatic group with up to 10 carbon atoms or a substituted or unsubstituted aromatic group with 6 to 10 carbon atoms, more preferred there is no R2and - NR4NHCO- is connected via the carbon atom of CO- to R3and R4is H or a straight or branched, saturated or unsaturated, substituted or unsubstituted, aliphatic group with up to 8 carbon atoms or a substituted or unsubstituted aromatic group with 6 to 10 carbon atoms.

[0043] In another preferred embodiment the present invention provides a hydrazide terminated polyisocyanate with alternative definition in the general Formula (I), wherein X is N, R2is H, m is o

[0044] 1, n is between 3 and 6 and R3 wherein the (CH2)4is connected to the terminal hydrazide functionality with m =1. This is the same preferred embodiment if X in general Formula (I) is -NR4NHCO-, wherein R2is not there, -NR4NHCO- is connected via the carbon atom of CO- to R3, R4is H, m is 1, n is between 3 and 6 and R3is -(CH2)4-.

[0045] The hydrazide terminated polyisocyanate has essentially no free isocyanate present, wherein essentially preferably means an free isocyanate content below 1 % by weight, preferably less than 0.5 % by weight, more preferably less than 0.1 % by weight determined according to DIN-EN ISO 11909:2007-05, most preferably no detectable NCO groups by IR spectroscopy.

[0046] The hydrazide terminated polyisocyanate with the general Formula (I) is obtainable or can be obtained, preferably is directly obtained, by the reaction of a polyisocyanate A and at least one compound B, comprising at least one terminal hydrazide functionality and a second terminal hydrazide or hydrazine functionality or a thiol group or a hydroxy group, optionally in the presence of a catalyst C.

[0047] In general the starting materials can be added in arbitrary order. During the reaction, polyisocyanate A or solution of polyisocyanate A in a solvent miscible with water and inert towards isocyanate groups, preferably acetone, can be added into solution of compound B in water and a solvent miscible with water and inert towards isocyanate groups, preferably acetone. Or it is also possible to preemulsify the poly isocyanate A in water and then add the emulsion of polyisocyanate into the solution of compound B in water and a solvent miscible with water and inert towards isocyanate groups, preferably acetone. If polyisocyanate A comprises hydrophilic groups, for example as mentioned below, the of pre-emulsification embodiment of the inventive process is preferred. Another option is to pre-emulsify poly isocyanate A in water and add the emulsion of polyisocyanate A into a mixture of compound B and a emulsion of the modified resin containing at least one polyurethane or polyacrylic or polyurethane acrylic structure and comprising at least one keto structure directly. Thereby, the process efficiency could be further improved.

[0048] The hydrazide terminated polyisocyanate with the general Formula (I) can be preferably obtained by conversion of a polyisocyanate A and at least one compound B, comprising at least one terminal hydrazide functionality and a second terminal hydrazide or hydrazine functionality or a thiol group or a hydroxy group, optionally in the presence of a catalyst C. For this, polyisocyanate A is reacted with compound B comprising at least one terminal hydrazide functionality and a second terminal hydrazide functionality or a thiol group or a hydroxy group, optionally in the presence of catalyst C.

[0049] In a preferred embodiment of the process, the conversion (or “reaction”) is carried out by a procedure in which: a polyisocyanate component A with an average NCO functionality of 2,0 to 5.0 and a content of aliphatically, cycloaliphatically, araliphatically and / or aromatically bonded isocyanate groups (calculated as NCO, molecular weight=42) of 8.0 to 27.0 wt. % is reacted with a compound B, comprising at least one terminal hydrazide functionality, and optionally a catalyst C up to 2 % by weight, based on the total weight of components A and B.

[0050] The polyisocyanate A is one or more of the following: a polyisocyanate with isocyanate groups linked by aliphatic, cycloaliphatic, aromatic or araliphatic linkages. Such polyisocyanates include one or more of the following structures: diisocyanate dimer structure, isocyanurate structure, allophanate structure, uretdione structure, biuret structure, carbodiimide structure and triazine structure, which can be obtained by modifying the appropriate diisocyanate, as described in J. Prakt. Chem. 336 (1994) 185-200 and EP-A0336205, EP-A0339396 and EP-A0798299. Moreover, the polyisocyanate A to be employed in the process as a rule has preferably an average NCO functionality of 2 to 5, preferably 2.3-4.5 and / or a content of isocyanate groups of 8-27 wt%, preferably 14 to 24 wt%. It comprises at least one organic polyisocyanate with aliphatically cycloaliphtically, araliphatically and or aromatically bonded isocyanate groups.

[0051] The polyisocyanate discussed in the process typically corresponds to the polyisocyanate described in R1of the general Formula (I). For sake of clarity, the term "polyisocyanate" in "R1is independently selected from a residue left after the isocyanate functional group on a polyisocyanate have reacted with a functional group containing an active hydrogen" does not include monomeric diisocyanates.

[0052] The preferred polyisocyanate A includes one or more of the following: a polyisocyanate with aliphatic linkages and a polyisocyanate with cycloaliphatic linkages. The more preferred polyisocyanate includes one or more of the following: a polyisocyanate based on hexamethylene diisocyanate with isocyanurate structure, a polyisocyanate based on pentamethylene diisocyanate with an isocyanurate structure, a polyisocyanate based on isophorone diisocyanate with an isocyanurate structure, and a poly isocyanate based on 4,4 ’-diisocyanate diphenylmethane with an isocyanurate structure. The further preferred polyisocyanates are low-viscosity aliphatic polyisocyanates and / or hydrophilically modified aliphatic polyisocyanates. Even more preferred are low-viscosity polyisocyanates based on hexamethylene diisocyanate and / or based on pentamethylene diisocyanate and / or hydrophilically modified aliphatic polyisocyanates based on hexamethylene diisocyanate and / or based on pentamethylene diisocyanate.

[0053] In order to prepare the starting polyisocyanate A, preferably the starting poly isocyanurate, any desired monomeric diisocyanate and triisocyanate that can be obtained via phosgenation or non- phosgenation methods such as thermal decomposition of aminocarbonyl groups can be used. The preferred diisocyanates are those with isocyanate groups containing alkyl, cycloalkyl, arylalkyl, and / or aryl connections and a molecular weight of 140-400. The following are the most preferred: l,4-bis(isocyanatomethyl)cyclohexane, pentamethylene diisocyanate (1,5-diisocyanatopentane or PDI), hexamethylene diisocyanate (1,6-diisocyanatohexane or HDI), 2-methyl-l,5-diisocyanato- hexane, l,5-diisocyanato-2,2-dimethylpentane, 2,2,4-trimethyl-l,6-diisocyanatohexane, 2,4,4- trimethyl-l,6-diisocyanatohexane, 1,10-diisocyanatodecane, 1,3-diisocyanatocyclohexane, 1,4- diisocyanatocyclohexane, 1 ,3 -bis(isocyanatomethyl)cyclohexane, 1,4- bis(isocyanatomethyl)cyclohexane, isophorone diisocyanate (IPDI), 4,4’-diisocyanato- dicyclohexy Imethane, 1 -isocy anato- 1 -methy l-4(3)-isocy anatomethyl-cy clohexane, dimethyldicyclohexylmethane diisocyanate (H12MDI), tetramethylxylylene diisocyanate (TMXDI), 2,4- and 2,6-diisocyanato-toluene, 2,4’-diisocyanatodiphenylmethane, pentamethylene diisocyanate, 4,4’- diisocyanatodiphenylmethane, and 1,5-diisocyanatonaphthalene.

[0054] Suitable polyisocyanate containing HDI asymmetric trimer could be Desmodur® N 3900 which can be obtained from Covestro. Suitable polyisocyanate containing HDI allophanate could be Desmodur® XP 2860 which can be obtained from Covestro. Suitable polyisocyanate containing HDI uretdione could be Desmodur® N 3400 which can be obtained from Covestro. Suitable HDI-based isocyanurates could be Desmodur® N3600 from Covestro, Tolonate™ HDT LV from Vencorex, Duranate™ TPA-100 from Asahi Kasei, Vestanat® HT 2500 / LV from Evonik, Coronate® HXR LV from Tosoh, Basonat® HA 1000 and Basonat® HA 2000 from BASF and Wannate® HT-600 from Wanhua. Suitable PDI-based isocyanurates could be Desmodur® CQ N7300 from Covestro. Suitable hydrophilically modified polyisocyanates A can be selected rather freely by the skilled person, possible examples include HDI- or PDI- polyisocyanates like Bayhydur® ultra 305, Bayhydur® ultra 3100 or Bayhydur® CQ 701-90.

[0055] Compound B (also named “Component” B), comprising at least one terminal hydrazide functionality as well as a second terminal hydrazide functionality or a thiol group or a hydroxy group, can also be a mixture of one or more compounds mentioned below. The more preferred are compounds B containing acyl hydrazide. The most preferred ones are adipic dihydrazide and carbonyldihydrazide.

[0056] The compound B could be hydrazide compounds containing hydroxy group like 2-Hydroxyacetic acid hydrazide, 2-hydroxy-2-methyl-propanehydrazid, 3-hydroxypropanehydrazide, 2- hydroxypropanehydrazide.

[0057] The compound B could be hydrazide compounds containing thiol group like 2- sulfanylacetohydrazide, 3 -Mercaptopropanehydrazide, 2-mercapto-, hydrazide.

[0058] The preferred component b comprises or is hydrazide compounds containing terminal hydrazides, with a terminal hydrazide functionality of 2 to 5. The more preferred terminal hydrazide functionality is 2 to 3, and the most preferred is 2.

[0059] It could most preferably be one or more of the following: ethane dihydrazide, adipic dihydrazide, carbonyl dihydrazide, malonic dihydrazide, succinic dihydrazide, isophthalic dihydrazide, terephthalic dihydrazide, aliphatic dihydrazides, phthalic dihydrazide, cyclohexane- 1,2- dicarbohydrazide, hydrazine dicarboxylate, decanedioic dihydrazide, isophthalic acid dihydrazide, 2, 5-bis(2 -ethoxy ethoxy)-!, 4-benzenedicarbohydrazide, 2,5-bis(allyloxy)-l,4- benzenedicarbohydrazide, sebacic dihydrazide, lauroyl hydrazide, adipyl hydrazide, dodecanedioic dihydrazide, 2,5 -bis(2-isobutoxyethoxy)- 1 ,4-benzenedicarbohydrazide, 4,4 ’ -diphenylmethane dihydrazide, and octanedioic dihydrazide or their mixtures. However, the present invention is not limited to monomers derived from the above.

[0060] The optional catalyst C is preferably one or more of the following: sulfonic catalysts, phosphoric catalysts, tertiary amine catalysts, tertiary phosphine catalysts, tertiary hydroxyalkylamine catalysts and metal catalysts, most preferably one or more of the following: metal catalysts and phosphoric catalysts.

[0061] The sulfonic acid catalyst is preferably one or more of the following: methanesulfonic acid, p- toluenesulfonic acid, trifluoromethanesulfonic acid, perfluorobutanesulfonic acid, dodecylbenzenesulfonic acid, methyl- and ethyl-toluenesulfonic salt.

[0062] The phosphoric acid catalyst is preferably one or more of the following: silylated acids, monoalkyl phosphates and dialkyl phosphates, more preferably one or more of the following: monobutyl phosphate, mono(tridecyl) phosphate, dibutyl phosphate, dioctyl phosphate, trimethylsilyl mesylate, trimethylsilyl triflate, tris(trimethylsilyl) phosphate and diethyl(trimethylsilyl) phosphate, most preferably one or more of the following: monobutyl phosphate and dibutyl phosphate.

[0063] The tertiary amine catalyst is preferably one or more of the following: triethylamine, tributylamine, N,N-dimethylaniline, N-ethylpiperidine and N,N'-dimethylpiperazine.

[0064] The tertiary phosphine catalyst is preferably one or more of the following: triethylphosphine, tributylphosphine and dimethylphenylphosphine.

[0065] The tertiary hydroxyalkylamine catalyst is preferably those described in line 30-35 in page 3 of GB2221465 and / or line 11 in page 2 of GB2222161, most preferably one or more of the following: triethanolamine, N-methyldiethanolamine, dimethylethanolamine, mixtures of a tertiary bicyclic amine (e.g., DBU) with a low-molecular-weight simple aliphatic alcohol, N- isopropyldiethanolamine and l-(2-hydroxy ethyl) pyrrolidine.

[0066] The metal catalyst may be those described in line 32-35 in page 8 of DE3240613, preferably one or more of the following: manganese octoates, iron octoates, cobalt octoates, nickel octoates, copper octoates, zinc octanoates, zirconium octanoates, cerium octanoates, lead octanoates, manganese naphthenates, iron naphthenates, cobalt naphthenates, nickel naphthenates, copper naphthenates, zinc naphthenates, zirconium naphthenates, cerium naphthenates, lead naphthenates and mixtures of the above-mentioned salts and lithium, sodium, potassium, calcium or barium acetate. The metal catalyst may also be those described in DE line 5-11 in page 4 of US4604418 A, preferably one or more of the following: sodium salts of linear or branched alkane carboxylic acids having up to 10 carbon atoms and potassium salts of linear or branched alkane carboxylic acids having up to 10 carbon atoms, wherein the carboxylic acid is preferably one or more of the following: propionic acid, butyric acid, valeric acid, hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid, decanoic acid and undecanoic acid.

[0067] The metal catalyst may also be a salt of alkali metals and / or a salt of alkaline earth metals as described in line 8-13 in page 3 of EPA0100129, preferably one or more of the following: Aliphatic, cycloaliphatic or aromatic mono-carboxylic acid and poly -carboxylic acids having 2-20 carbons with sodium benzoate or potassium benzoate. The metal catalyst may also be alkali metal phenolates known in line 90-92 in page 1 of GB1391066A and GB1386399A, preferably one or more of the following: sodium phenolates and potassium phenolates. The metal catalyst can also be those known in line 37-42 in page 1 of GB 809809, preferably one or more of the following: alkali metal oxides, alkaline earth metal oxides, alkali metal hydroxides, alkaline earth metal hydroxides, alkali metal carbonates, alkaline earth metal carbonates, alkali metal alkoxides, alkaline earth metal alkoxides, alkali metal phenolates, alkaline earth metal phenolates, alkali metal salts of alkylenatable compounds, metal salts of weak aliphatic carboxylic acids, metal salts of alicyclic carboxylic acids, basic alkali metal compounds complexed with crown ethers, and basic alkali metal compounds complexed with poly ether alcohols.

[0068] The metal catalyst may also be potassium salts of pyrrolidones known from line 5-8 in page 1 of EP0033581. The metal catalyst can also be monocyclic or polycyclic complexes of titanium, zirconium and / or hafnium known in line 24-34 in page 2 of EP2883895, preferably one or more of the following: zirconium tetra-n-butyrate, zirconium tetra-2-ethylhexanoate and zirconium tetra-2- ethylhexanoate. The metal catalyst can also be tin compounds of the type described in European Polymer Journal, 16, 1979, 147-148, preferably one or more of the following: dibutyltin dichloride, diphenyltin dichloride, triphenyltin alkanolate, tributyltin acetate, tributyltin oxide, tin octoate, dibutyl(dimethoxy)stannane, and tributyltin imidazol.

[0069] The metal salt of weak aliphatic carboxylic acids and the metal salt of the alicyclic carboxylic acids are each independently preferably one or more of the following: sodium methanolate, sodium acetate, potassium acetate, sodium acetoacetate, lead 2-ethylhexanoate and lead naphthenates.

[0070] The basic alkali metal compound complexed with crown ethers and the basic alkali metal compound complexed with polyether alcohols are each independently preferably one or more of the following: complexed sodium or potassium carboxylates, which can be known in line 54-58 in page 3 of US4487928 A.

[0071] In the following the term “system” is used for the hydrazide terminated polyisocyanate. When the system comprises a metal catalyst, a terminator is preferably used after the reaction of the system is completed. In addition, the above-mentioned phosphoric catalysts, sulfonic catalysts and derivatives thereof can be used here as the terminator. In addition to these two catalysts, other inorganic acids such as hydrochloric acid, phosphorous acid, acid chlorides such as acetyl chloride, benzoyl chloride or isophthaloyl dichloride can also be used as the terminator.

[0072] The amount of the catalyst is preferably 0% by weight to 2 % by weight, more preferably 0 % by weight to 1 % by weight, even more preferably 0.0001 % by weight to 0.5 % by weight and most preferred 0.005 % by weight to 0.02% by weight, relative to the total weight of the hydrazide terminated polyisocyanate.

[0073] The system may further include a solvent that is inert or reactive to the isocyanate groups. The inert solvents for isocyanate may include, but are not limited to, one or more of the following: ethyl acetate, butyl acetate, ethylene glycol monomethyl ether, ethyl ether acetate, 1 -methoxy -2-propyl acetate, acetone, 2-butanone, 4-methyl-2 -pentanone, cyclohexanone, toluene, dipropylene glycol diacetate, diglyme, diethylene glycol monoethyl ether, butyl ether acetate, N-methylpyrrolidone, and N- methylcaprolactam.

[0074] Reactive solvents for isocyanate may include, but are not limited to, one or more of the following: water, small molecule alcohols such as monofunctional or multifunctional alkyl alcohols having 1- 10 carbon atoms, aromatic alcohols, etc.

[0075] Generally the hydrazide terminated polyisocyanate of general formula (I) can be identified for example by combination of 13C-NMR with IR spectroscopy.

[0076] When used, the hydrazide terminated polyisocyanate can be mixed with an isocyanate different from the hydrazide terminated polyisocyanate, for example, a non-modified isocyanate. Such isocyanate different from the inventive hydrazide terminated polyisocyanate, for example the non-modified isocyanates, can be selected from the generally known isocyanates and polyisocyanates. Preferably, however, 0 to 10% by weight and most preferably no other isocyanate different from the hydrazide terminated polyisocyanate is used. Modified resin containing at least one polyurethane or polyacrylic or polyurethane acrylic structure and comprising at least one keto structure:

[0077] In another preferred embodiment the present invention provides a coating composition, wherein the at least one keto structure of the modified resin conforms to the following general Formula (II),

[0078] Formula (II), wherein R and R" are independently selected from hydrogen atom or methyl group.

[0079] This structure of general Formula (II) can be obtained by introducing monomers containing carbon groups into the main chain of the molecular chain. The most preferred form of this patent is diacetone acrylamide (DAAM) and acetylacetoxyethyl methacrylate (AAEM), which can be one or more of them. The total amount of one or more added is 0.1% to 15% by weight of the total amount of monomers, and the most preferred form is 0.4% to 10% by weight to achieve the best balance between cost performance.

[0080] The monomers containing ketone carbonyls in general Formula (II) can be DAAM or AAEM, but are not limited to both.

[0081] The ratio of hydrazide terminated polyisocyanate with the general Formula (I) to the modified resin containing at least one polyurethane or polyacrylic or polyurethane acrylic structure and comprising at least one keto structure can be varied over a broad range but is preferably calculated as the terminal hydrazide group: ketone carbonyl group and lies in a range from 0.1:1 to 1.2:1 based on the molar ratio of the ketone group, particularly preferably from 0.3:1 to 0.98:1.

[0082] The one component water borne coating composition and its preparation process:

[0083] The inventive one component water borne coating composition can be prepared by mixing at least one hydrazide terminated polyisocyanate with the general Formula (I) with at least one modified resin containing at least one polyurethane or polyacrylic or polyurethane acrylic structure and comprising at least one keto structure and / or by preparing the at least one hydrazide terminated polyisocyanate with the general Formula (I) in the presence of at least one modified resin containing at least one polyurethane or polyacrylic or polyurethane acrylic structure and comprising at least one keto structure. The hydrazide terminated polyisocyanate with the general Formula (I) referred to in this section and the claims thereto is the same as defined and preferably defined above in the description of the present invention. The hydrazide terminated polyisocyanate depicted by general formula (I) is used preferably as curing agent for a polyurethane or polyacrylic (PAC) emulsion containing keto carbonyl moieties. During drying process of the resin, with the evaporation of water and the pH of the system changing from alkaline to acidic, the ketone carbonyl group and the hydrazide group in the inventive one component water borne coating composition the inventors assume that it will undergo a keto hydrazide selfcrosslinking reaction, which can be carried out even at room temperature, therefore ultimately achieving the goal of self-crosslinking at room temperature as described in the present invention. This crosslinking reaction forms interpenetrating polymer network (IPN), which augments the crosslinking density, barrier properties, mechanical properties and chemical resistance of the film.

[0084] Preferably in the inventive process is the modified resin obtainable or obtained by introducing monomers containing carbon groups into the main chain of the molecular chain, preferably using diacetone acrylamide (DAAM) and / or acetylacetoxyethyl methacrylate (AAEM) as one of the monomers, preferably diacetone acrylamide or acetylacetoxyethyl methacrylate.

[0085] Alternatively or additionally preferred is the inventive process wherein the total amount of the monomers containing carbon groups is 0.1% to 15% of the total amount of monomers of the modified resin, and the most preferred form is 0.4% to 10% of the total amount of monomers of the modified resin.

[0086] The ratio of hydrazide terminated polyisocyanate with the general Formula (I) to the modified resin containing at least one polyurethane or polyacrylic or polyurethane acrylic structure and comprising at least one keto structure can be varied over a broad range in the inventive process, but is preferably calculated as the terminal hydrazide group : ketone carbonyl group and lies in a range from 0.1 : 1 to 1.2:1 based on the molar ratio of the ketone group, particularly preferably from 0.3:1 to 0.98:1

[0087] The inventive one component water borne coating composition has the advantages of high efficiency, convenience, widely adjustable performance, low cost, energy conservation and environmental protection, which is conducive to promoting the use of high-performance water-based resin, especially in replacing traditional two-component (2K) water-based resin.

[0088] The invention is further described in detail below through examples, which are only used to illustrate the invention and do not limit the scope of the invention. Examples

[0089] All percentages in the present invention are weight percentages, unless otherwise specified.

[0090] Measurements for the present invention are conducted at 23±2°C and 50±5% relative humidity, unless otherwise specified.

[0091] Non-volatile components [% by weight] : about 1 g sample was spread on glass fiber filter on top of an aluminum sample pan. Solid content was tested by Metteler Teredo Halogen Moisture Analyzer Excellence HS153. Drying program: standard, drying temperature: 120 °C, switch-off criterion: 5 (1 mg / 140 seconds) (keep heating sample at 120 °C and keep weighing, if weight loss in 140 seconds is less than 1 mg, stop testing and record rest weight percentage as result.).

[0092] Viscosity of polyisocyanate is determined according to DIN EN ISO 3219:1994-10, at 23 °C with a shear rate of 10 s-1 using an MV-DIN rotor. Color values are measured in accordance with DIN EN 1557: 1997-03.

[0093] Viscosity of examples and comparison examples: 150 g sample was filled in glass bottle. Viscosity of sample was tested by Brookfield DV-II+ Pro viscometer at room temperature (20 to 25 oC), using spindle S62 (unless specifically mentioned) at rotation speed 30 rpm according to ISO 3219: 1994.

[0094] Raw materials list:

[0095] Rhodapon UB-WX: Alkyl sulfate as surfactant

[0096] ADH: Adipic hydrazide, Bought from TCI.

[0097] Bayhydur® ultra 305: Water-dispersible Polyisocyanate, from Covestro, NCO content: 16.2%wt, Viscosity(mPa.s): 6500 mPa.s

[0098] Bayhydur® XP 2655: Polyisocyanate, HDI trimer, from Covestro. NCO content: 21.5%wt, Viscosity(mPa.s): 3500mPa.s

[0099] Covestro NeoRez R-1007: water borne PUD

[0100] Defoamer: Isofoam 16

[0101] Desmodur® N 3600: Poly isocyanate, HDI trimer, from Covestro. NCO content: 23.5%wt, Viscosity(mPa.s): 1200mPa.s; used as 50% wt. acetone solution.

[0102] Disponil® SLS 103: Surfactant from BASF

[0103] Emulsifier: EMULGATOR FD400 (15% solution in water) polytetrahydrofuran ether glycol (PTMG-1000): molecular weight 1000 g / mol, available from BASF Bruggolite FF6: sodium salt of an organic sulfinic acid derivative; reducing agent for emulsion polymerization. BYK028: Defoamer, available from BYK Auxiliary (Shanghai) Co., Ltd.

[0104] TEGO410: Levelling agent

[0105] BYK349: Levelling agent

[0106] PUR-64: Thickener

[0107] Synthesis of hydrazide terminated polyisocyanates:

[0108] Hydrazide terminated polyisocyanate 1 :

[0109] Four-necked flask equipped with a stirrer, a thermometer, a reflux condenser, a nitrogen blowing tube, and a dropping funnel were purged with a nitrogen atmosphere. A solution of 212.0 g ADH (8%wt in water) and 72.9 g acetone was added. The mixture was stirred and heated to 40°C, followed by dropwise addition of a solution of 50 g Bayhydur® ultra 305 in acetone (50%wt). After the dropwise addition was completed, stirring was continued. The disappearance of the isocyanate functional group absorption peak was monitored by an infrared spectroscopy. Then, 1.26 g EMULGATOR FD400 was added. After removing excess acetone under vacuum, a white emulsion with solid content of 20.2%wt, viscosity of 88 mPa.s (23.5 °C), particle size of 600 nm, and pH of 7 was obtained.

[0110] Hydrazide terminated polyisocyanate 2:

[0111] Four-necked flask equipped with a stirrer, a thermometer, a reflux condenser, a nitrogen blowing tube, and a dropping funnel were purged with a nitrogen atmosphere. A solution of 273.8 g ADH (8%wt in water) and 50.6 g acetone was added. The mixture was stirred and heated to 40 °C, and then 0.31 g triethylamine was added. Subsequently, a solution of 50 g Bayhydur® XP 2655 in acetone (50%wt) was added dropwise. After dropwise addition was completed, stirring was continued. The disappearance of the isocyanate functional group absorption peak was monitored by an infrared spectroscopy. Then, 1.41 g EMULGATOR FD400 and 0.06 g isofoam 16 were added. After removing excess acetone under vacuum, a white emulsion with solid content of 20%wt, viscosity 230 mPa.s (23.5 °C), particle size of 1100 nm, and pH of 6.3 was obtained.

[0112] Hydrazide terminated polyisocyanate 3:

[0113] Four-necked flask equipped with a stirrer, thermometer, reflux condenser, nitrogen blowing tube, and dropping funnel were purged with nitrogen. A solution of 212 g CDH (4.3% wt in water) and 127.1 g acetone was added, and heated to 40 °C with agitation. Then, a solution of 50.0 g Bayhydur® ultra 3100 in acetone (50% wt) was added dropwise. After the dropwise addition was completed, agitation was continued. The disappearance of the isocyanate functional group absorption peak was monitored by an infrared spectrometer. Subsequently, 1.1 g EMULGATOR FD400 and 0.05 g isofoam 16 were added, and excess acetone was removed by vacuum. A white emulsion with a solids content of 11% wt, viscosity of 149 mPa.s (23.5 °C), particle size of 3200 nm, and pH of 6.6 was obtained.

[0114] Hydrazide terminated polyisocyanate 4:

[0115] Four-necked flasks equipped with a stirrer, a thermometer, a reflux condenser, a nitrogen blowing tube, and a dropping funnel were purged with a nitrogen atmosphere. A solution of 442.7 g ADH (3.3%wt in water) and 649.1 g acetone was added. The mixture was stirred and heated to 40°C, followed by dropwise addition of a solution of 30 g Desmodur® N 3600 in acetone (50%wt). After the dropwise addition was completed, stirring was continued. The disappearance of the isocyanate functional group absorption peak was monitored by an infrared spectroscopy. Then, 0.083 g EMULGATOR FD400 and 0.05 g isofoam 16 were added. After removing excess acetone under vacuum, a white emulsion with solid content of 7%wt, viscosity of 608 mPa.s (23.5 °C), particle size of 2368 nm, and pH of 8.7 was obtained.

[0116] Synthesis of the one-component coating compositions:

[0117] Example 1 (Single-phase structure):

[0118] 32 parts of deionized water and 1 part of RHODAPON®UB-WX were added to the reactor with 0.05 part ammonium persulfate (APS) and heated to 50 °C. 7 parts of deionized water and 0.5 parts of RHODAPON® UB-WX were added to the monomer tank with 7 parts styrene (S), 10 parts methyl methacrylate (MMA), 26 parts butyl methacrylate (BMA), 1 parts methacrylic acid (MAA), 1.7 parts diacetone acrylamide (DAAM) and everything were mixed well. In an initiator tank, 0.2 parts of APS and 5 parts of water were mixed until fully dissolved. 10% of the mixture from the monomer tank were added to the reactor at 50 °C, after temperature was raised up to 85 °C and then started to feed the monomer tank and initiator tank simultaneously for 120 minutes and continued to hold for 60 minutes after feeding. After cooling down to below 30°C and then pH was adjusted to 7.0-9.0 by ammonia.

[0119] Then 10 parts of Hydrazide terminated polyisocyanate 1 were added and 0.3 parts of biocide benzoisothiazolinone (BIT) were added, evenly stirred , resulting in a -45% solid water-based acrylic resin.

[0120] Example 2 (Single-phase structure):

[0121] 32 parts of deionized water and 1 part of RHODAPON® UB-WX were added to the reactor with, 0.05 part ammonium persulfate (APS), and heated to 50 °C . 7 parts of deionized water and 0.5 parts of RHODAPON® UB-WX were added to the monomer tank with, 7 parts styrene (S), 10 parts methyl methacrylate (MMA), 20 parts butyl methacrylate (BMA), 1 parts methacrylic acid (MAA), 5.8 parts diacetone acrylamide (DAAM) and everything were mixed well. In an initiator tank, 0.2 parts of APS and 5 parts of water were mixed until fully dissolved. 5 parts of the mixture from the monomer tank were added to the reactor at 50 °C. After temperature was raised up to 85 °C and then started to feed the monomer tank and initiator tank simultaneously for 120 minutes and continued to hold for 60 minutes after feeding. After cooling down to below 30°C and then pH was adjusted to 7.0-9.0 by ammonia. Then 8.4 parts of the Hydrazide terminated polyisocyanate 1 were added and 0.3 parts of biocide BIT were added, evenly stirred, resulting in a -42% solid water-based acrylic resin.

[0122] Example 3 (Muti-phase structure):

[0123] 12.5 parts of deionized water and 1.2 parts of Disponil® SLS 103 were added to the reactor, with 0.05 part ammonium persulfate (APS), and heated to 50 °C . 2.4 parts of deionized water and 0.6 parts of Disponil® SLS 103 were added to the monomer tank with, 8 parts styrene (S), 8 parts methyl methacrylate (MMA), 4 parts butyl methacrylate (BMA), 1 parts methacrylic acid (MAA), and 0.3 parts acetylacetoxyethyl methacrylate (AAEM) (0.67% to total monomer), and everything were mixed well. In an initiator tank, 0.2 parts of APS and 1.6 parts of water were mixed until fully dissolved. 10% of the mixture from the monomer tank were added to the reactor at 50 °C, after temperature was raised up to 85 °C and then started to feed the monomer tank in 120 minutes and initiator tank in 360 minutes. After the monomer feeding is completed, continue to hold for 60 minutes. During holding process, 0.9 parts of diacetone acrylamide (DAAM), 6 parts of methyl methacrylate (MMA), 7 parts of butyl acrylate (BA), 5 parts of butyl methacrylate (BMA), and 1 parts of MAA were added to the monomer tank and mixed well. After holding process, continue to feed monomer tank for 120 minutes and hold for 60 minutes after feeding is completed. Added 8.4 parts of water to rinse and cool. Then cooled to below 30 °C and pH was adjusted to 7.0-9.0 by ammonia. Then 12 parts of the hydrazide terminated polyisocyanate 2 were added and evenly mixed; 0.3 parts of biocide BIT were added, the pH value to 7.0-9.0 were checked and adjusted as needed, resulting in a 40% solid water-based acrylic polyurethane resin.

[0124] Example 4 (polyurethane acrylate (PUA)):

[0125] 59.9 parts of Covestro NeoRez R-1007, which is water-based polyurethane resin, and 4.3 parts of deionized water were added to the reactor, mixed evenly, and then the temperature raised to 90 °C .

[0126] 3.5 parts of deionized water and 0.7 parts of Disponil® SLS 103 were added to the monomer tank in turn, 0.4 parts diacetone acrylamide (DAAM), 2 parts butyl acrylate (BA), and 17.6 parts methyl methacrylate (MMA), were mixed well. In an initiator tank, mix 0.2 parts of APS and 4.7 parts of water were mixed evenly. Starting at 90 °C, the monomer tank and the initiator tank were feed simultaneously for 60 minutes. After the monomer feeding was completed, it was continued to hold for 60 minutes. Then, the temperature was reduced to below 30 °C and 3.9 parts of hydrazide terminated polyisocyanate 4 were added and evenly mixed. Then 0.3 parts of biocide BIT were added and stirred evenly; pH was checked and adjusted to 7.0-9.0 as needed, resulting in a -45% solid water-based acrylic resin.

[0127] Example 5 (polyacrylate grafted polyurethane):

[0128] 4.2 parts of acetone, 12.2 parts of polytetrahydrofuran ether glycol (PTMG-1000, Mw 1000), 1 part of dimethylol propionic acid (DMPA), 3.3 parts of hydroxy ethyl methacrylate (HEMA), 0.02 parts of dibutyltin dilaurate (T12), and 0.01 parts of 2,6-di-tert-butyl-p-methylphenol (BHT) were added to the reactor, mixed evenly, and then temperature was raised to 50 °C . Then 11.1 parts of isophorone diisocyanate (IPDI) was added to reactor; and temperature was raised to 90 °C and kept for 2 hours until NCO% was below 8.06%. After that the reactor was cooled to below 80 °C and 0.7 parts of triethylamine (TEA) was added. The reactor was then cooled to below 30 °C and 1.1 parts of 64% hydrazine solution was added in reactor. 47 parts of deionized water was added into dispersion reactor, and then prepolymer in reactor was fed into dispersion kettle for 90 minutes with high-speed emulsification to obtain a light blue translucent emulsion. 0.8 parts of diacetone acrylamide (DAAM) and 10 parts of methyl methacrylate (MMA) were added to monomer tank and mixed evenly. Half of the monomer mixture was added to dispersion reactor at 30 °C, stirred for 40 minutes, and then 0.02 parts of Bruggolite FF6 and 0.04 parts of hydrogen peroxide were added to dispersion reactor for redox reaction. Temperature was raised to - 45 °C from exothermic reaction and then lowered to 30 °C. Remaining monomers was added to dispersion reactor, stirred for 20 minutes, and then 0.01 parts of Bruggolite FF6 and 0.01 parts of hydrogen peroxide were added for the redox reaction. After temperature reached heat peak, hold for 60 minutes as needed. After the completion of the polymerization, the acetone in the resin was removed by vacuum distillation. Then the reactor was cooled to below 30 °C and pH value was adjusted to 7.0 to 9.0 as needed.

[0129] Then 4.8 parts of hydrazide terminated polyisocyanate 3 were added and evenly mixed. After that, 0.3 parts of BIT were added and stirred evenly; pH was checked and adjusted to 7.0-9.0 as needed, resulting in a -45% solid water-based acrylic resin.

[0130] Comparative example 1

[0131] 32 parts of deionized water and 1 part of RHODAPON®UB-WX were added to the reactor with 0.05 part ammonium persulfate (APS) and heated to 50 °C. 7 parts of deionized water and 0.5 parts of RHODAPON® UB-WX were added to the monomer tank with 7 parts styrene (S), 10 parts methyl methacrylate (MMA), 26 parts butyl methacrylate (BMA), 1 parts methacrylic acid (MAA), 1.7 parts diacetone acrylamide (DAAM) and everything mixed well. In an initiator tank, 0.2 parts of APS and 5 parts of water were mixed until fully dissolved. 10% of the mixture from the monomer tank were added to the reactor at 50°C, after temperature was raised up to 85 °C and then started to feed the monomer tank and initiator tank simultaneously for 120 minutes and continued to hold for 60 minutes after feeding. After cooling down to below 30 °C and then pH was adjusted to 7.0-9.0 by ammonia. Then 0.8 parts of ADH were added to reactor and mixed evenly. And then 0.3 parts of biocide benzoisothiazolinone (BIT) were added and evenly stirred, resulting in a -45% solid water-based acrylic resin.

[0132] Comparative example 2:

[0133] 32 parts of deionized water and 1 part of RHODAPON®UB-WX were added to the reactor with 0.05 part ammonium persulfate (APS) and heated to 50 °C. 7 parts of deionized water and 0.5 parts of RHODAPON® UB-WX were added to the monomer tank with 1.7 parts hydroxyethyl methacrylate (HEMA), 7 parts styrene (S), 10 parts methyl methacrylate (MMA), 26 parts butyl methacrylate (BMA), 1 parts methacrylic acid (MAA) and everything were mixed well. In an initiator tank, 0.2 parts of APS and 5 parts of water were mixed until fully dissolved. 10% of the mixture from the monomer tank were added to the reactor at 50 °C, after temperature was raised up to 85 °C and then started to feed the monomer tank and initiator tank simultaneously for 120 minutes and continued to hold for 60 minutes after feeding. After cooling down to below 30 °C and then pH was adjusted to 7.0-9.0 by ammonia. And then 0.3 parts of biocide benzoisothiazolinone (BIT) were added and evenly stirred, resulting in a -45% solid water-based acrylic resin with OH value at -1.9%.

[0134] Comparative example 2 was used in combination with polyisocyanate crosslinker as a 2K formulation.

[0135] Application tests:

[0136] After the addition of a cosolvent and other additives to the synthetic resin in the examples 1 to 5 and comparative examples 1 and 2, water was used to dilute and adjust the viscosity. The Polyisocyanate crosslinker in 2K formulation of comparative example 2 was Bay hy dur® 305 diluted in 25% DPM and was added at a molar ratio of NCO / OH=1: 1.5. The fullcoating formulations are summarized in table 1.

[0137] Table 1: Overview on prepared coating system formulations

[0138] Raw materials Weight percent

[0139] Examples 1 to 5 and Comparative Examples 1 and 2 80

[0140] BYK028 0.3

[0141] TEGO410 0.2

[0142] BYK349 0.5

[0143] PUR-64 0.7

[0144] DPM 2

[0145] DPnB 3

[0146] Di-water 13.3

[0147] Total 100 The coating formulations were scraped to a glass plate and the paint film performance was tested after 24 hours at 50°C . The test results are shown in table 2. Table 2: Test results of the obtained films

[0148] Test Test results

[0149] Test items methods Ex. 1 Ex. 2 Ex. 3 Ex. 4 Ex. 5 Comp. ex. 1 Comp. ex. 2

[0150] Thickness Thickness

[0151] 30-35 30-35 30-35 30-35 30-35 30-35 30-35

[0152] (um) Meter

[0153] GB / T

[0154] Adhesion

[0155] 9286- 0 Grade 0 Grade 0 Grade 0 Grade 0 Grade 0 Grade 0 Grade

[0156] (h)

[0157] 1998

[0158] Pencil GB / T hardness (7 6739- H 2H F H H 3B H days) 1996

[0159] Water GB / T resistance 1733- 5 5 4 5 5 2 4

[0160] (24h) 1993

[0161] Alcohol GB / T resistance 23989- 5 4 5 5 5 2 4

[0162] (Ih) 2009 remarks: 5 is best , 0 is poorest

[0163] Discussion of examples:

[0164] From the data in table 2, it can be seen that the hardness of the paint film on the glass plate of all examples has been greatly improved, basically reaching a hardness level of 2K. Further chemical resistance tests also found excellent water, acid, and alkali resistance for the inventive one component water borne coating composition. The traditional comparative IK self-crosslinking system performs significantly worse in this aspect. For the comparative 2K system, in addition to the obvious cost advantages, the performance is basically the same as that of 2K, indicating that the structural design method shown in the invention can greatly improve the performance of IK aqueous resin, with the technical advantage of improved pot-life compared to the 2K system.

Claims

1. Claims:

1. A one component water borne coating composition, comprising at least one hydrazide terminated polyisocyanate with the general Formula (I),wherein R1is independently selected from a residue left after the isocyanate functional group on a polyisocyanate have reacted with a functional group containing an active hydrogen, n is a number from 2.0 to less than or equal to 6.0, m is an integer from 1 to 3,X is independently selected from -NR4NH-, -NR4NHCO- or a heteroatom such as O or S, R3is independently selected from a straight or branched, saturated or unsaturated, substituted or unsubstituted, aliphatic group with up to 18 carbon atoms or a substituted or unsubstituted aromatic group with 6 to 18 carbon atoms, and wherein when X is O or S there is no R2and wherein when X is -NR4NH- then there is no R2and no R3and -NR4NH- is connected via the nitrogen atom of NH to the carbonyl atom of the terminal carbonylhydrazide and R4is H or a straight or branched, saturated or unsaturated, substituted or unsubstituted, aliphatic group with up to 18 carbon atoms or a substituted or unsubstituted aromatic group with 6 to 18 carbon atoms and wherein when X is -NR4NHCO- then there is no R2and -NR4NHCO- is connected via the carbon atom of CO- to R3and R4is H or a straight or branched, saturated or unsaturated, substituted or unsubstituted, aliphatic group with up to 18 carbon atoms or a substituted or unsubstituted aromatic group with 6 to 18 carbon atoms and further comprising at least one modified resin containing at least one polyurethane or polyacrylic or polyurethane acrylic structure and comprising at least one keto structure.

2. The coating composition according to claim 1, wherein the polyisocyanate in R1include one or more of the following structures: diisocyanate dimer structure, isocyanurate structure, allophanate structure, uretdione structure, biuret structure, carbodiimide structure and triazine structure.

3. The coating composition according to claim 1 or 2, wherein the polyisocyanate in R1include one or more of a polyisocyanate based on hexamethylene diisocyanate with isocyanuratestructure, a polyisocyanate based on pentamethylene diisocyanate with an isocyanurate structure, a polyisocyanate based on isophorone diisocyanate with an isocyanurate structure and a poly isocyanate based on 4,4 ’-diisocyanate diphenylmethane with an isocyanurate structure.

4. The coating composition according to any one of claims 1 to 3, wherein in general Formula (I), R1is independently selected from a residue left after the isocyanate functional group on a polyisocyanate have reacted with a functional group containing an active hydrogen, n is a number from 2.0 to less or equal to 5.0, m is an integer from 1 to 2,X is independently selected from -NR4NH-, -NR4NHCO- or a heteroatom such as O or S, preferably -NR4NH- or -NR4NHCO-,R3is independently selected from a straight or branched, saturated or unsaturated, substituted or unsubstituted, aliphatic group with up to 10 carbon atoms or a substituted or unsubstituted aromatic group with 6 to 10 carbon atoms, most preferred with up to 8 carbon atoms or a substituted or unsubstituted aromatic group with 6 to 10 carbon atoms, and wherein when X is O or S there is no R2, and wherein when X is -NR4NH- then there is no R2and no R3and -NR4NH- is connected via the nitrogen atom of NH to the carbonyl atom of the terminal carbonylhydrazide and R4is H or a straight or branched, saturated or unsaturated, substituted or unsubstituted, aliphatic group with up to 10 carbon atoms or a substituted or unsubstituted aromatic group with 6 to 10 carbon atoms, more preferred there is no R2and no R3and -NR4NH- is connected via the nitrogen atom of NH to the carbonyl atom of the terminal carbonylhydrazide and R4is H or a straight or branched, saturated or unsaturated, substituted or unsubstituted, aliphatic group with up to 8 carbon atoms or a substituted or unsubstituted aromatic group with 6 to 10 carbon atoms, and wherein when X is -NR4NHCO- then there is no R2and -NR4NHCO- is connected via the carbon atom of CO- to R3and R4is H or a straight or branched, saturated or unsaturated, substituted or unsubstituted, aliphatic group with up to 10 carbon atoms or a substituted or unsubstituted aromatic group with 6 to 10 carbon atoms, more preferred there is no R2and - NR4NHCO- is connected via the carbon atom of CO- to R3and R4is H or a straight or branched, saturated or unsaturated, substituted or unsubstituted, aliphatic group with up to 8 carbon atoms or a substituted or unsubstituted aromatic group with 6 to 10 carbon atoms.

5. The coating composition according to any one of claims 1 to 4, wherein the at least one keto structure of the modified resin conforms to the following general Formula (II),Formula (II),wherein R and R’ ’ are independently selected from hydrogen atom or methyl group6. The coating composition according to any one of claims 1 to 5, wherein the ratio of hydrazide terminated polyisocyanate with the general Formula (I) to the modified resin containing at least one polymethane or polyacrylic or polymethane acrylic structure and comprising at least one keto structure is calculated as the terminal hydrazide group: ketone carbonyl group and lies in a range from 0.1 : 1 to 1.2: 1 based on the molar ratio of the ketone group, particularly preferably from 0.3:1 to 0.98:1.

7. A process for preparing a one component water borne coating composition, wherein at least one hydrazide terminated polyisocyanate with the general Formula (I) ),wherein R1is independently selected from a residue left after the isocyanate functional group on a polyisocyanate have reacted with a functional group containing an active hydrogen, n is a number from 2.0 to less than or equal to 6.0, m is an integer from 1 to 3,X is independently selected from -NR4NH-, -NR4NHCO- or a heteroatom such as O or S, R3is independently selected from a straight or branched, saturated or unsaturated, substituted or unsubstituted, aliphatic group with up to 18 carbon atoms or a substituted or unsubstituted aromatic group with 6 to 18 carbon atoms, and wherein when X is O or S there is no R2and wherein when X is -NR4NH- then there is no R2and no R3and -NR4NH- is connected via the nitrogen atom of NH to the carbonyl atom of the terminal carbonylhydrazide and R4is H or a straight or branched, saturated or unsaturated, substituted or unsubstituted, aliphatic group with up to 18 carbon atoms or a substituted or unsubstituted aromatic group with 6 to 18 carbon atoms and wherein when X is -NR4NHCO- then there is no R2and -NR4NHCO- is connected via the carbon atom of CO- to R3and R4is H or a straight or branched, saturated or unsaturated, substituted or unsubstituted, aliphatic group with up to 18 carbon atoms or a substituted or unsubstituted aromatic group with 6 to 18 carbon atoms, is mixed with and / or prepared in the presence of at least one modified resin containing at least one polymethane or polyacrylic or polymethane acrylic structure and comprising at least one keto structure.

8. The process according to claim 7, wherein the modified resin is obtainable or obtained by introducing monomers containing carbon groups into the main chain of the molecular chain, preferably using diacetone acrylamide and / or acetylacetoxyethyl methacrylate as one of the monomers, preferably diacetone acrylamide or acetylacetoxyethyl methacrylate.

9. The process according to claim 8, wherein the total amount of the monomers containing carbon groups is 0.1% to 15% of the total amount of monomers of the modified resin, and the most preferred form is 0.4% to 10% of the total amount of monomers of the modified resin.

10. A use of the one component water borne coating composition according to any one of claims 1 to 6 for protecting a surface of a substrate or preparing a coating on the surface of a substrate or for an adhesive or for a sealing or for a molded article.

11. A coating method comprising the steps of: applying the one component water borne coating composition according any one of claims 1 to 6 or applying the one component water borne coating composition, obtainable or obtained by a process according to any one of claims 7 to 9 onto a surface of a substrate, and then curing and drying, optionally under the influence of heat.

12. A coating obtainable or obtained, preferably directly obtained by the coating method of claim 11.

13. A coated product comprising a substrate and a coating obtainable or obtained, preferably directly obtained, according to the coating method of claim 11 or by applying the one component water borne coating composition according to any one of claims 1 to 6 onto the substrate and then curing and drying, optionally under the influence of heat, wherein the coated product is preferably selected from building walls, furniture surfaces, floors or metal surfaces.

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