Polyaziridine compounds

Abstract

The present invention relates to a polyaziridine compound, which has: a) 2 to 6 of the following structural units (A): #imgabs0# wherein R1 is H, R2 and R4 are independently selected from H or an aliphatic hydrocarbon group containing 1 to 4 carbon atoms, R3 is an aliphatic hydrocarbon group containing 1 to 4 carbon atoms, R'=H or an aliphatic hydrocarbon group containing 1 to 4 carbon atoms; R" and R'" are independently selected from an aliphatic hydrocarbon group containing 1 to 4 carbon atoms, an alicyclic hydrocarbon group containing 4 to 12 carbon atoms, or an aliphatic hydrocarbon group containing 6 to 12 carbon atoms; a) an aromatic hydrocarbon group containing from 4 to 8 carbon atoms, wherein R' (when different from H) and R" can be part of the same saturated alicyclic hydrocarbon group containing from 4 to 8 carbon atoms, optionally containing heteroatoms, wherein R" and R"' can be part of the same saturated alicyclic hydrocarbon group containing from 4 to 8 carbon atoms, optionally containing heteroatoms, b) one or more connecting chains, wherein each of these connecting chains connects two structural units A in said structural unit A; and c) a molecular weight in the range of 600 Daltons to 5000 Daltons.

Description

[0001] The present invention relates to compounds having at least two aziridine groups, which can be used, for example, for crosslinking carboxylic acid-functional polymers, for example dissolved and / or dispersed in aqueous media.

[0002] Over the years, there has been an increasing demand for coatings with improved resistance properties (such as stain resistance and solvent resistance), improved mechanical properties, and improved bond strength. One or more of these properties can be enhanced to even higher levels by crosslinking. Many crosslinking mechanisms have been investigated over the years, and for aqueous dispersions, the most useful crosslinking mechanisms include isocyanate crosslinking of hydroxyl-functional dispersions, reactions between carbodiimides and carboxylic acids, epoxy crosslinking, and crosslinking using aziridine-based crosslinking agents.

[0003] US-A-5133997 describes a coating composition comprising an aqueous dispersion of a linear aliphatic polyurethane resin, an anionic surfactant, and a cross-linking agent capable of promoting the curing of the resin. Trimethylolpropane tris(2-methyl-1-aziridine propionate), CAS No. 64265-57-2, is a multifunctional aziridine cross-linking agent used as a cross-linking agent. It is well known and highly active for cross-linking carboxylic acid functional polymers. However, this cross-linking agent has unfavorable genotoxic characteristics. US-A-2015118501 relates to an anti-fog coating composition comprising an aqueous polymer dispersion and a cross-linking agent such as an aziridine cross-linking agent; in Preparation Example 4, a multifunctional aziridine cross-linking agent was prepared by Michael addition of ethoxylated trimethylolpropane triacrylate and 2-methylaziridine. US-A-3763132 relates to curable compositions comprising carboxyl-containing polymers and aziridines, such as adducts of propylene imine and trimethylolpropane trimethacrylate, which can be used as, for example, coating applications. There is a need in the industry to improve the safety, health and environmental characteristics of adhesives, inks and coatings and materials for the preparation of adhesives, inks and coatings. Genotoxicity describes the properties of chemical or physical agents that cause any type of DNA damage, which may not always result in transmissible mutations. Mutagenicity refers to the induction of permanent transmissible DNA changes (as DNA constituents or chromosome structure) that are maintained in somatic cell division and passed on to progeny in germ cells. Genotoxicity must not be confused with mutagenicity. All mutagens are genotoxic, but not all genotoxic substances are mutagenic.

[0004] The present invention aims to provide a compound having at least two aziridinium groups which has reduced genotoxicity compared to trimethylolpropane tris(2-methyl-1-aziridine propionate) and good crosslinking efficiency. Compounds having at least two aziridinium groups are also referred to herein as polyaziridine compounds.

[0005] This object has surprisingly been achieved by providing polyaziridine compounds having:

[0006] a) 2 to 6 of the following structural units (A):

[0007]

[0008] in

[0009] R1 is H,

[0010] R2 and R4 are independently selected from H or an aliphatic hydrocarbon group containing 1 to 4 carbon atoms,

[0011] R3 is an aliphatic hydrocarbon group containing 1 to 4 carbon atoms;

[0012] R′=H or an aliphatic hydrocarbon group containing 1 to 4 carbon atoms;

[0013] R" and R'" are independently selected from an aliphatic hydrocarbon group containing 1 to 4 carbon atoms, an alicyclic hydrocarbon group containing 4 to 12 carbon atoms, or an aromatic hydrocarbon group containing 6 to 12 carbon atoms,

[0014] wherein R′ (if different from H) and R″ may be part of the same saturated alicyclic hydrocarbon radical containing 4 to 8 carbon atoms, optionally containing heteroatoms, and

[0015] wherein R" and R"' may be part of the same saturated alicyclic hydrocarbon group containing 4 to 8 carbon atoms, optionally containing heteroatoms;

[0016] b) one or more connecting chains, wherein each of these connecting chains connects two of the structural units A present in the polyaziridine compound; and

[0017] c) A molecular weight in the range of 600 to 5000 Daltons.

[0018] Surprisingly, it has been found that the polyaziridine compounds according to the invention have reduced genotoxicity compared to trimethylolpropane tris(2-methyl-1-aziridine propionate). The polyaziridine compounds according to the invention show only weakly positive induced genotoxicity, or even no genotoxicity, i.e., they show genotoxicity levels comparable to the naturally occurring background.

[0019] Genotoxicity can be treated by Measurements were performed using the Toxys® assay (Toxys, Leiden, the Netherlands). The assay can be applied to pure substances or to compositions that are direct products obtained in the preparation of the polyaziridine compounds of the present invention. Positive induction of genotoxicity means that the induction level of the biomarkers Bscl2-GFP and Rtkn-GFP in the absence or presence of a metabolic system rat S9 liver extract is equal to or higher than 2 times at least one of 10%, 25% and 50% cytotoxicity. Weak positive induction of genotoxicity means that the induction level of the biomarkers Bscl2-GFP and Rtkn-GFP in the absence or presence of a metabolic system based on rat S9 liver extract (aroclor1254-induced rats, Moltox, Boone, NC, USA) is higher than 1.5 times and lower than 2 times at at least one of 10%, 25% and 50% cytotoxicity (but lower than 2 times at 10%, 25% and 50% cytotoxicity). Genotoxicity comparable to the naturally occurring background means that the induction levels of the biomarkers Bscl2-GFP and Rtkn-GFP in the absence and presence of a metabolic system based on rat S9 liver extract (aroclor1254-induced rats, Boone, NC, USA) are less than or equal to 1.5 times the levels at 10%, 25%, and 50% cytotoxicity. In the absence and presence of a metabolic system based on rat S9 liver extract (aroclor1254-induced rats, Moltox, Boone, NC, USA), the induction levels of the genotoxicity reporter genes Bscl2-GFP and Rtkn-GFP are preferably less than or equal to 1.5 times the levels at 10%, 25%, and 50% cytotoxicity. Substances that exhibit induction levels less than or equal to 1.5 times the levels at 10%, 25%, and 50% cytotoxicity in the absence and presence of a metabolic system based on rat S9 liver extract (aroclor1254-induced rats, Moltox, Boone, NC, USA) are not genotoxic.

[0020] The crosslinking efficiency of a crosslinking agent can be assessed by evaluating the chemical resistance as defined and determined as described below.

[0021] For all upper and / or lower boundaries of any range given herein, unless otherwise specifically stated, the boundary values are included in the given range. Thus, when it is said from x to y, it is meant to include x and y and also all intermediate values.

[0022] In this specification, the term "coating composition" encompasses paints, coatings, varnishes, adhesives, and ink compositions, but is not limited to this list. The term "aliphatic hydrocarbon group" refers to optionally branched alkyl, alkenyl, and alkynyl groups. The term "alicyclic hydrocarbon group" refers to cycloalkyl and cycloalkenyl groups optionally substituted with at least one aliphatic hydrocarbon group. The term "aromatic hydrocarbon group" refers to a benzene ring optionally substituted with at least one aliphatic hydrocarbon group. These optional aliphatic hydrocarbon substituents are preferably alkyl groups. Examples of alicyclic hydrocarbon groups having 7 carbon atoms are cycloheptyl and methyl-substituted cyclohexyl. Examples of aromatic hydrocarbon groups having 7 carbon atoms are methyl-substituted phenyl. Examples of aromatic hydrocarbon groups having 8 carbon atoms are xylyl and ethyl-substituted phenyl.

[0023] Although the structural units (A) present in the polyaziridine compounds according to the present invention may independently have different R2, R3, R4, R', R", and / or R'", the structural units (A) present in the polyaziridine compounds are preferably identical to each other.

[0024] The polyaziridine compound according to the present invention is usually obtained with a composition in which, in addition to the polyaziridine compound, there may also be remaining starting materials, by-products and / or solvents for the preparation of the polyaziridine compound. The composition may only contain one polyaziridine compound according to the present invention, but may also contain more than one polyaziridine compound according to the present invention. For example, when a mixture of polyisocyanates is used as the starting material, a mixture of polyaziridine compounds is obtained.

[0025] The carbamate aziridine compound of the present invention contains 2 to 6 structural units (A), preferably 2 to 4 structural units (A), more preferably 2 or 3 structural units (A).

[0026] R1 is H. R2 and R4 are independently selected from H or an aliphatic hydrocarbon group containing 1 to 4 carbon atoms. Preferably, R2 and R4 are independently selected from H or an aliphatic hydrocarbon group containing 1 to 2 carbon atoms.

[0027] R3 is an aliphatic hydrocarbon group containing 1 to 4 carbon atoms, preferably an aliphatic hydrocarbon group containing 1 to 2 carbon atoms.

[0028] In a preferred embodiment of the present invention, R2 is H, R3 is C2H5 and R4 is H. In another more preferred embodiment of the present invention, R2 is H, R3 is CH3 and R4 is H or CH3. In another even more preferred embodiment of the present invention, R2 is H, R3 is CH3 and R4 is H.

[0029] R'=H or an aliphatic hydrocarbon group containing 1 to 4 carbon atoms; R" and R'" are independently selected from an aliphatic hydrocarbon group containing 1 to 4 carbon atoms, an alicyclic hydrocarbon group containing 4 to 12 carbon atoms, or an aromatic hydrocarbon group containing 6 to 12 carbon atoms.

[0030] wherein R' (when different from H) and R" may be part of the same saturated alicyclic hydrocarbon group containing 4 to 8 carbon atoms, optionally containing heteroatoms.

[0031] wherein R" and R'" may be part of the same saturated alicyclic hydrocarbon group containing 4 to 8 carbon atoms, optionally containing heteroatoms.

[0032] Preferably, R′═H; R″ and R′″ are aliphatic hydrocarbon groups containing 1 to 4 carbon atoms, alicyclic hydrocarbon groups containing 4 to 12 carbon atoms or aromatic hydrocarbon groups containing 6 to 12 carbon atoms, wherein R″ and R′″ may be part of the same saturated alicyclic hydrocarbon group containing 4 to 8 carbon atoms, optionally containing heteroatoms. More preferably, R′═H and R″ and R′″ are aliphatic hydrocarbon groups containing 1 to 4 carbon atoms. More preferably, R′═H and R″ and R′″ are aliphatic hydrocarbon groups containing 1 to 2 carbon atoms. Most preferably, R′═H and R″ and R′″ are CH groups.

[0033] The molecular weight of the polyaziridine compound according to the present invention is 600 dalton to 5000 dalton. The molecular weight of the polyaziridine compound according to the present invention is preferably 3800 dalton at the most, more preferably 3600 dalton at the most, more preferably 3000 dalton at the most, more preferably 1600 dalton at the most, even more preferably 1200 dalton at the most. The molecular weight of the polyaziridine compound according to the present invention is preferably at least 700 dalton, more preferably at least 800 dalton, even more preferably at least 840 dalton. As used herein, the molecular weight of the polyaziridine compound is the calculated molecular weight. The calculated molecular weight is obtained by adding the atomic masses of all atoms present in the structural formula of the polyaziridine compound. If the polyaziridine compound is present in a composition comprising more than one polyaziridine compound according to the present invention, for example, when one or more starting materials in the starting material for the preparation of the polyaziridine compound are a mixture, then molecular weight calculation can be performed for each compound present alone in the composition. As described in the experimental section below, the molecular weight of the polyaziridine compound according to the present invention can be measured using MALDI-TOF mass spectrometry.

[0034] The polyaziridine compound according to the present invention comprises one or more connecting chains, wherein each of these connecting chains connects two structural units A in the structural unit A. The connecting chain present in the polyaziridine compound is preferably composed of 4 to 300 atoms, more preferably 5 to 250 atoms, more preferably 6 to 100 atoms, most preferably 6 to 20 atoms. The atoms of the connecting chain are preferably C and optionally N, O, S and / or P, preferably C and optionally N and / or O. The connecting chain is preferably a collection of covalently linked atoms, the collection of atoms being composed of i) carbon atoms, ii) carbon and nitrogen atoms, or iii) carbon, oxygen and nitrogen atoms.

[0035] The connecting chain is defined as the shortest chain of consecutive atoms connecting two structural units A. The figure below shows an example of the polyaziridine compound according to the present invention, and a connecting chain between two structural units A.

[0036]

[0037] Any two structural units A present in the polyaziridine compounds of the present invention are connected by a connecting chain as defined herein. Therefore, each structural unit A present in the polyaziridine compounds of the present invention is connected to each other structural unit A by a connecting chain as defined herein. In the case where the polyaziridine compound according to the present invention has two structural units A, the polyaziridine compound has one such connecting chain connecting these two structural units.

[0038] In the case where the polyaziridine compound according to the present invention has three structural units A, the polyaziridine compound has three connecting chains, wherein each of the three connecting chains connects the structural unit A with another structural unit A, that is, the first structural unit A is connected to the second structural unit A through the connecting chain, and the first and second structural units A are each independently connected to the third structural unit A through their corresponding connecting chains.

[0039] The following figures show examples of polyaziridine compounds having three structural units A and three connecting chains, wherein each of the three connecting chains connects two structural units A.

[0040]

[0041] The polyaziridine compounds according to the invention having more than two structural units A have the number of connecting chains according to the following equation:

[0042] LC = {(AN-1) x AN)} / 2, where LC = the number of connecting chains in the polyaziridine compound, and AN = the number of structural units A in the polyaziridine compound. Thus, for example, if there are 5 structural units A in the polyaziridine compound, AN = 5; this means that there are {(5-1) x 5} / 2 = 10 connecting chains.

[0043] Preferably, the number of consecutive C atoms and optionally O atoms between the N atom of the carbamate group in the structural unit A and the next N atom (which is present in the connecting chain or is the N atom of the carbamate group of another structural unit A) is at most 9, as shown, for example, below in the polyaziridine compounds according to the invention.

[0044]

[0045] The polyaziridine compound according to the present invention preferably contains one or more linking groups, wherein each of these linking groups connects two structural units A in the structural unit A, and wherein each of these linking groups consists of at least one functional group selected from the group consisting of: aliphatic hydrocarbon functional groups (preferably containing 1 to 8 carbon atoms), alicyclic hydrocarbon functional groups (preferably containing 4 to 10 carbon atoms), aromatic hydrocarbon functional groups (preferably containing 6 to 12 carbon atoms), isocyanurate functional groups, iminooxadiazinedione functional groups, ether functional groups, ester functional groups, amide functional groups, carbonate functional groups, carbamate functional groups, urea functional groups, biuret functional groups, allophanate functional groups, uretdione functional groups and any combination thereof. More preferably, the linking group is an array of continuous functional groups, wherein each functional group is selected from the group consisting of: an aliphatic hydrocarbon functional group (preferably containing 1 to 8 carbon atoms), an alicyclic hydrocarbon functional group (preferably containing 4 to 10 carbon atoms), an aromatic hydrocarbon functional group (preferably containing 6 to 12 carbon atoms), an isocyanurate functional group, an iminooxadiazinedione functional group, an ether functional group, an ester functional group, an amide functional group, a carbonate functional group, a carbamate functional group, a urea functional group, a biuret functional group, an allophanate functional group, and a uretdione functional group.

[0046] The following figure shows in bold the linking groups of an example of a polyaziridine compound according to the present invention. In this example, the linking group connecting two structural units A in the structural unit A consists of the following array of consecutive functional groups: aliphatic hydrocarbon functional group 1 (straight chain C6H 12 ), isocyanurate 2 (cyclic C3N3O3) functional group and aliphatic hydrocarbon functional group 3 (straight chain C6H 12 ).

[0047]

[0048] The following figure shows in bold the following example linking groups of the polyaziridine compound according to the present invention. In this example, the linking group connecting the two structural units A consists of the following array of continuous functional groups: aliphatic hydrocarbon functional group 1 (straight chain C6H 12 ), isocyanurate 2 (cyclic C3N3O3) and aliphatic hydrocarbon functional group 3 (straight chain C6H 12 ).

[0049]

[0050] In the polyaziridine compound of the present invention, any two structural units A in the structural unit A present are preferably connected by a linking group, and the linking group is as defined herein. Therefore, each structural unit A present in the polyaziridine compound of the present invention is preferably connected with each other structural unit A using a linking group, and the linking group is as defined in the present invention. In the case where the polyaziridine compound according to the present invention has two structural units A, the polyaziridine compound has a such linking group connecting these two structural units. In the case where the polyaziridine compound according to the present invention has three structural units A, the polyaziridine compound has three such linking groups, and wherein each linking group in the three linking groups links structural unit A to another structural unit A.

[0051] The figure below shows an example of a polyaziridine compound having three structural units A and three linking groups, wherein each of the three linking groups connects two structural units A. One linking group consists of the following array of consecutive functional groups: an aliphatic hydrocarbon functional group 1 (straight chain C6H 12 ), isocyanurate 2 (cyclic C3N3O3) and aliphatic hydrocarbon functional group 3 (straight chain C6H 12 For the connection between the structural units A labeled A1 and A3, the linking group consists of the following array of consecutive functional groups: aliphatic hydrocarbon functional group 1 (straight chain C6H 12 ), isocyanurate 2 (cyclic C3N3O3) and aliphatic hydrocarbon functional group 4 (straight chain C6H 12 ), and for the connection between the structural units A labeled A2 and A3, the linking group consists of the following array of consecutive functional groups: aliphatic hydrocarbon functional group 3 (straight chain C6H 12 ), isocyanurate 2 (cyclic C3N3O3) and aliphatic hydrocarbon functional group 4 (straight chain C6H 12 ).

[0052]

[0053] Preferably, linking group is made up of at least one functional group selected from the group consisting of: aliphatic hydrocarbon functional group (preferably containing 1 to 8 carbon atoms), alicyclic hydrocarbon functional group (preferably containing 4 to 10 carbon atoms), aromatic hydrocarbon functional group (preferably containing 6 to 12 carbon atoms), isocyanurate functional group, iminooxadiazinedione functional group, carbamate functional group, urea functional group, biuret functional group and their any combination.Linking group preferably contains isocyanurate functional group, iminooxadiazinedione functional group, biuret functional group, allophanate functional group or uretdione functional group. More preferably, linking group contains isocyanurate functional group or iminooxadiazinedione functional group. For the sake of clarity, the polyaziridine compound can be obtained from the reaction product of one or more suitable compounds B with a hybrid isocyanurate (e.g., HDI / IPDI isocyanurate), thereby producing a polyaziridine compound having a linking group consisting of an array of the following consecutive functional groups: linear C6H 12 (i.e., an aliphatic hydrocarbon functional group having 6 carbon atoms), an isocyanurate functional group (cyclic C3N3O3), and

[0054]

[0055] (ie, an alicyclic hydrocarbon functional group having 9 carbon atoms and an aliphatic hydrocarbon functional group having 1 carbon atom).

[0056] The term "aliphatic hydrocarbon functional group" refers to optionally branched alkyl, alkenyl and alkynyl groups. Although the optional branches of C atoms are part of the linking group, they are not part of the linking chain. The term "alicyclic hydrocarbon functional group" refers to cycloalkyl and cycloalkenyl groups that are optionally substituted with at least one aliphatic hydrocarbon group. Although the optional aliphatic hydrocarbon substituent is part of the linking group, it is not part of the linking chain. The optional aliphatic hydrocarbon substituent is preferably an alkyl group. The term "aromatic hydrocarbon functional group" refers to a benzene ring that is optionally substituted with at least one aliphatic hydrocarbon group. The optional aliphatic hydrocarbon substituent is preferably an alkyl group. Although the optional aliphatic hydrocarbon substituent is part of the linking group, it is not part of the linking chain.

[0057] On the linking group, one or more substituents may be present as pendant groups on the linking group, as shown in bold in, for example, the following polyaziridine compounds. These pendant groups are not part of the linking group.

[0058]

[0059] The side groups preferably contain Where X, R7, R8, n′ and R 10As described below. In one embodiment of the present invention, the polyaziridine compound comprises one or more linking groups, wherein each of these linking groups links two structural units A in the structural unit A, wherein the linking group consists of the following: (i) at least two aliphatic hydrocarbon functional groups or at least two alicyclic hydrocarbon functional groups, and (ii) an isocyanurate functional group or an iminooxadiazinedione functional group, and wherein the side group is present on the linking group, wherein the side group has the following structural formula:

[0060]

[0061] n′ is the number of repeating units, and is an integer of 1 to 50, preferably 2 to 30, more preferably 5 to 20.

[0062] X is O or NH, preferably X is O,

[0063] In each repeating unit, R7 and R8 are independently H or CH3,

[0064] R9 is an aliphatic hydrocarbon group preferably containing 1 to 8 carbon atoms, or an alicyclic hydrocarbon group preferably containing 4 to 10 carbon atoms, and

[0065] R 10 Contains up to 20 carbon atoms and is an aliphatic hydrocarbon group, an alicyclic hydrocarbon group or an aromatic hydrocarbon group, or a combination thereof. In a preferred embodiment, one of R7 and R8 is H, and the other R7 or R8 is CH3. In another more preferred embodiment, R7 and R8 are H. R 10 Preferably, the polyaziridine compound contains an aliphatic hydrocarbon group (preferably CH3) having 1 to 20 carbon atoms, an alicyclic hydrocarbon group having 5 to 20 carbon atoms, or an aromatic hydrocarbon group having 6 to 20 carbon atoms. The presence of the side group causes the viscosity of the polyaziridine compound to decrease and is therefore more easily miscible with the polymer to be cross-linked. In this embodiment, the polyaziridine compound preferably contains 2 structural units A. In this embodiment, the linking group is preferably composed of an array of the following consecutive functional groups: a first alicyclic hydrocarbon functional group, an isocyanurate functional group or an iminooxadiazinedione functional group, and a second alicyclic hydrocarbon functional group, and R9 is an alicyclic hydrocarbon group, wherein the first alicyclic hydrocarbon functional group and the second alicyclic hydrocarbon functional group are the same as R9, more preferably, the linking group is composed of an array of the following consecutive functional groups: a first aliphatic hydrocarbon functional group, an isocyanurate functional group or an iminooxadiazinedione functional group and a second aliphatic hydrocarbon functional group, and R9 is an aliphatic hydrocarbon functional group, wherein the first aliphatic hydrocarbon functional group and the second aliphatic hydrocarbon functional group are the same as R9.

[0066] In a preferred embodiment, the polyaziridine compound according to the present invention preferably contains polyoxyethylene (—O—CH 2 -CH 2 -) in an amount of preferably at least 0.1 wt %, more preferably at least 6 wt %, more preferably at least 10 wt % and preferably less than 45 wt %, more preferably less than 25 wt %, most preferably less than 16 wt % relative to the polyaziridine compound. x Groups and / or polyoxypropylene (-O-CHCH3-CH2-) x Preferably, the polyaziridine compound contains polyoxyethylene (—O—CH 2 -CH 2 -) in an amount of preferably at least 0.1 wt %, more preferably at least 6 wt %, more preferably at least 10 wt % and preferably less than 45 wt %, more preferably less than 45 wt % and most preferably less than 16 wt % relative to the polyaziridine compound. x Group. Contains polyoxyethylene (-O-CH2-CH2-) x The polyaziridine compound of the group is preferably a reaction product of at least compound (B), a polyisocyanate and an alkoxy poly(ethylene glycol), preferably a methoxy poly(ethylene glycol) (MPEG) and / or poly(ethylene glycol). The reaction product can be obtained by reacting at least compound B, a polyisocyanate and an alkoxy poly(ethylene glycol) and / or poly(ethylene glycol), wherein compound B has the following structural formula

[0067]

[0068] wherein R′ and R″ are as defined above. The reaction product can also be obtained by reacting a polyisocyanate with an alkoxypoly(ethylene glycol) and / or poly(ethylene glycol) and reacting the compound thus obtained with compound (B). The reaction product can also be obtained by reacting compound (B) with a polyisocyanate and reacting the compound thus obtained with an alkoxypoly(ethylene glycol) and / or poly(ethylene glycol). The amount of alkoxypoly(ethylene glycol), preferably methoxypoly(ethylene glycol) (MPEG), and / or poly(ethylene glycol) (PEG) chains having an average molecular weight above 2200 Daltons, preferably an average molecular weight above 1600 Daltons, in the polyaziridine compound as defined above is preferably less than 35% by weight, more preferably less than 15% by weight, more preferably less than 5% by weight. %. The average molecular weight of the methoxy poly (ethylene glycol) (MPEG) and / or poly (ethylene glycol) (PEG) chains present in the polyaziridine compound is preferably less than 1100 daltons, more preferably less than 770 daltons, and most preferably less than 570 daltons. The average molecular weight is determined by multiplying the OH functionality of the polyol by the equivalent weight of the polyol. The OH functionality of the polyol is given by the supplier of the polyol. In the case where the polyol is a diol, the OH functionality is 2. The equivalent weight of the polyol is calculated by dividing 56100 by the OH value of the polyol. The OH value of the polyol is measured by titrating a known mass of polyol according to ISO14900 (2017) and is expressed as mg KOH / g polyol.

[0069] The aziridine group has the following structural formula:

[0070]

[0071] The isocyanurate functional group is defined as

[0072] The iminooxadiazinedione functional group is defined as

[0073] The allophanate functional group is defined as

[0074] The uretdione functional group is defined as

[0075] The biuret functional group is defined as

[0076] In a preferred embodiment of the present invention, the linking group present in the polyaziridine compound of the present invention is composed of the following functional groups: (i) at least one aliphatic hydrocarbon functional group and / or at least one alicyclic hydrocarbon functional group; and (ii) optionally at least one aromatic hydrocarbon functional group; and (iii) optionally an isocyanurate functional group or an iminooxadiazinedione functional group or an allophanate functional group or a uretdione functional group. Preferably, the linking group present in the polyaziridine compound of the present invention is composed of the following functional groups: (i) at least one aliphatic hydrocarbon functional group and / or at least one alicyclic hydrocarbon functional group; and (ii) optionally at least one aromatic hydrocarbon functional group; and (iii) optionally an isocyanurate functional group or an iminooxadiazinedione functional group. A very suitable way to obtain such polyaziridine compounds is to react compound B having the following structural formula with a polyisocyanate having aliphatic reactivity:

[0077]

[0078] The term "polyisocyanate with aliphatic reactivity" refers to compounds in which all isocyanate groups are directly bonded to aliphatic or alicyclic hydrocarbon groups, regardless of whether aromatic hydrocarbon groups are also present. The polyisocyanate with aliphatic reactivity may be a mixture of polyisocyanates with aliphatic reactivity. When compared with similar compounds but based on polyisocyanates with aromatic reactivity, compounds based on polyisocyanates with aliphatic reactivity have a reduced tendency to yellow over time. The term "polyisocyanate with aromatic reactivity" is intended to mean compounds in which all isocyanate groups are directly bonded to benzene or naphthalene groups, regardless of whether aliphatic or alicyclic hydrocarbon groups are also present. Preferred polyisocyanates with aliphatic reactivity are 1,5-pentamethylene diisocyanate PDI, 1,6-hexamethylene diisocyanate HDI, isophorone diisocyanate IPDI, 4,4′-dicyclohexylmethane diisocyanate H12MDI, 2,2,4-trimethylhexamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, tetramethylxylene diisocyanate TMXDI (all isomers) and higher molecular weight variants such as, for example, their isocyanurates or iminooxadiazinediones. More preferred polyisocyanates with aliphatic reactivity are isocyanurates or iminooxadiazinediones of 1,5-pentamethylene diisocyanate PDI, 1,6-hexamethylene diisocyanate HDI, isophorone diisocyanate IPDI, 4,4′-dicyclohexylmethane diisocyanate H12MDI, 2,2,4-trimethylhexamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, tetramethylxylene diisocyanate TMXDI. In this embodiment, preferably, the linking group consists of an array of the following consecutive functional groups: an aliphatic hydrocarbon functional group, an aromatic hydrocarbon functional group and an aliphatic hydrocarbon functional group (for example, when TMXDI is used to prepare the polyaziridine compound), or the linking group consists of an array of the following consecutive functional groups: an alicyclic hydrocarbon functional group, an aliphatic hydrocarbon functional group and an alicyclic hydrocarbon functional group (for example, when H12MDI is used to prepare the polyaziridine compound), or more preferably, the linking group consists of an array of the following consecutive functional groups: an aliphatic hydrocarbon functional group, an isocyanurate functional group or an iminooxadiazinedione functional group and an aliphatic hydrocarbon functional group. Most preferably, in this embodiment, the linking group consists of an array of the following consecutive functional groups: an aliphatic hydrocarbon functional group, an isocyanurate functional group, and an aliphatic hydrocarbon functional group (e.g., when the isocyanurate of 1,6-hexamethylene diisocyanate and / or the isocyanurate of 1,5-pentamethylene diisocyanate is used to prepare the polyaziridine compound).

[0079] The total amount of cyclic structures (other than aziridine) present in the polyaziridine compound is preferably at most 3, because this results in a lower viscosity than when there is a higher amount of cyclic structures. Lower viscosities are easier to handle and / or require less cosolvent to make the compound easier to handle. If the polyaziridine compound is solid at ambient temperature, then polyaziridine compounds with more than three cyclic structures can cause more difficulties when dissolving such polyaziridines. The total amount of cyclic structures (other than aziridine) present in the polyaziridine compound is more preferably from 0 to 2, even more preferably 1 or 2, and most preferably 1, the cyclic structure being preferably an isocyanurate or an iminooxadiazinedione.

[0080] The polyaziridine compounds according to the present invention preferably contain at least 5% by weight, more preferably at least 5.5% by weight, more preferably at least 6% by weight, more preferably at least 9% by weight, more preferably at least 12% by weight and preferably less than 25% by weight, preferably less than 20% by weight of carbamate bonds. The polyaziridine compounds according to the present invention preferably have an aziridine equivalent weight (molecular weight of the polyaziridine compound divided by the number of aziridines present in the polyaziridine compound) of at least 200 daltons, more preferably at least 230 daltons and even more preferably at least 260 daltons, and preferably at most 2500 daltons, more preferably at most 1000 daltons and even more preferably at most 500 daltons.

[0081] If necessary, then amines, preferably 0.1 wt % to 5 wt %, more preferably 0.1 wt % to 2.5 wt %, most preferably 0.1 wt % to 1 wt % of secondary or tertiary amines can be used to stabilize polyaziridine compounds. Preferred amines include ammonia, dimethylethanolamine, diisopropylamine, isopropanolamine, diethylethanolamine, N, N-dimethylisopropanolamine, 3-dimethylamino-1-propanol, 2-[2-(dimethylamino) ethoxy} ethanol, N-ethylmorpholine, dimethylbenzylamine and triethylamine. Alternatively, alkaline hydroxides can be used, such as, for example, NaOH, LiOH, KOH and a combination of amine and alkaline hydroxide.

[0082] The polyaziridine compounds according to the invention are preferably obtained by reacting at least a polyisocyanate with a compound B having the following formula:

[0083]

[0084] wherein the molar ratio of compound B to polyisocyanate is from 2 to 6, more preferably from 2 to 4, and most preferably from 2 to 3, and wherein R′, R″, R″′, R1, R2, R3 and R4 are as defined above. The reaction of the polyisocyanate with compound B can be carried out by contacting equal amounts of the polyisocyanate with compound B in the presence of, for example, a tin catalyst (e.g., dibutyltin dilaurate) or a bismuth catalyst (e.g., bismuth neodecanoate) at a temperature in the range of from 0°C to 110°C, more suitably from 20°C to 110°C, more suitably from 40°C to 95°C, even more suitably from 60°C to 85°C. A solvent such as dimethylformamide (DMF), acetone and / or methyl ethyl ketone can be used. The polyisocyanate contains at least 2 isocyanate groups, preferably at least 2.5 isocyanate groups on average, more preferably at least 2.8 isocyanate groups on average. Mixtures of polyisocyanates can also be used as starting materials. Preferred polyisocyanates are polyisocyanates with aliphatic reactivity. The term "polyisocyanate with aliphatic reactivity" refers to compounds in which all isocyanate groups are directly bonded to aliphatic or alicyclic hydrocarbon groups, regardless of whether aromatic hydrocarbon groups are also present. The polyisocyanate with aliphatic reactivity may be a mixture of polyisocyanates with aliphatic reactivity. Preferred polyisocyanates with aliphatic reactivity are 1,5-pentamethylene diisocyanate PDI, 1,6-hexamethylene diisocyanate HDI, isophorone diisocyanate IPDI, 4,4′-dicyclohexylmethane diisocyanate H12MDI, 2,2,4-trimethylhexamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, p-tetramethylxylene diisocyanate (p-TMXDI) and their meta-isomers, and also higher molecular weight variants, for example their isocyanurates or iminooxadiazinediones or allophanates or uretdiones. More preferred polyisocyanates with aliphatic reactivity are isocyanurates or iminooxadiazinediones of 1,5-pentamethylene diisocyanate PDI, 1,6-hexamethylene diisocyanate HDI, isophorone diisocyanate IPDI, 4,4′-dicyclohexylmethane diisocyanate H12MDI, 2,2,4-trimethylhexamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, tetramethylxylene diisocyanate TMXDI. Even more preferred polyisocyanates with aliphatic reactivity are isocyanurates or iminooxadiazinediones of 1,6-hexamethylene diisocyanate, isocyanurates or iminooxadiazinediones of 1,5-pentamethylene diisocyanate, isocyanurates or iminooxadiazinediones of IPDI. Suitable iminooxadiazinedione trimers containing HDI are available from Covestro. N3900. Suitable allophanates containing HDI are available from Covestro XP2860. Suitable uretdione containing HDI is available from Covestro N3400. Suitable HDI-based isocyanurate trimers are available, for example, from Covestro ( N3600), Vencorex (Tolonate TM HDT LV), Asahi Kasei (Duranate TM TPA-100)、Evonik( HT2500 / LV) and Tosoh( HXR LV) is obtained. Methods for preparing compound (B) are known in the art. Preferred aziridine compounds for preparing compound B are propylene imine, 2,2-dimethylaziridine and ethylaziridine. The synthesis of ethylaziridine is described, for example, in EP0227461B1. The most preferred aziridine compound for preparing compound B is propylene imine.

[0085] Compound B is preferably obtained by reacting an at least non-OH-functional monoepoxide compound with an aziridine compound of the following formula (C):

[0086]

[0087] wherein R1, R2, R3 and R4 are as defined above. The non-OH functional monoepoxide may be a mixture of different non-OH functional monoepoxides. Non-limiting examples of non-OH functional monoepoxides are 2,2-dimethyloxirane (=isobutylene oxide, CAS No. 558-30-5), 2-methyl-2-vinyloxirane (=isoprene monooxide, CAS No. 1838-94-4), 1-methylcyclopentene oxide (CAS No. 16240-42-9), 1-oxaspiro[2.4]heptane (CAS No. 185-60-4), 2-methyl-1,2-oxobutane (CAS No. 30095-63-7), 2,2,3-trimethyloxirane (CAS No. 5076-19-7), 2-methyl-2-(2-propen-2-yl)oxirane (CAS No. 34485-82-0) and any mixtures thereof. The non-OH-functional monoepoxide is preferably selected from the group consisting of 2,2-dimethyloxirane (=isobutylene oxide, CAS No. 558-30-5), 2-methyl-2-vinyloxirane (CAS No. 1838-94-4), 2-methyl-1,2-butylene oxide (CAS No. 30095-63-7), 2,2,3-trimethyloxirane (CAS No. 5076-19-7), and any mixtures thereof. More preferably, the non-OH-functional monoepoxide is selected from the group consisting of 2,2-dimethyloxirane (=isobutylene oxide, CAS No. 558-30-5), 2-methyl-2-vinyloxirane (CAS No. 1838-94-4), 2-methyl-1,2-butylene oxide (CAS No. 30095-63-7), and any mixtures thereof. Most preferably, the non-OH-functional monoepoxide is 2,2-dimethyloxirane (=isobutylene oxide, CAS No. 558-30-5).

[0088] The polyaziridine compound according to the present invention is preferably obtained by a process comprising at least the following steps (i) and (ii):

[0089] (i) reacting an aziridine compound of formula (C) with an at least non-OH-functional monoepoxide compound to obtain compound B, and

[0090] (ii) reacting compound B with a polyisocyanate.

[0091] Step (i) can be carried out, for example, by contacting one equivalent of the epoxide compound with one equivalent of the aziridine compound under atmospheric pressure at a temperature in the range of from 20° C. to 110° C., more suitably from 40° C. to 95° C., even more suitably from 60° C. to 85° C. The reaction of the adduct obtained in step (i) (compound (B)) with a polyisocyanate (step (ii)) can be carried out, for example, by contacting an equivalent amount of the polyisocyanate with the adduct in the presence of, for example, a tin catalyst (e.g., dibutyltin dilaurate) under atmospheric pressure at a temperature in the range of from 20° C. to 110° C., more suitably from 40° C. to 95° C.

[0092] Examples of preferred polyaziridine compounds according to the present invention are:

[0093]

[0094]

[0095] Another aspect of the present invention is a crosslinker composition comprising at least one polyaziridine compound as defined above and further comprising at least one additional component, such as remaining starting materials, by-products and / or solvents used in the preparation of the polyaziridine compound according to the present invention. The crosslinker composition may comprise only one polyaziridine compound according to the present invention, but may also contain more than one polyaziridine compound according to the present invention. For example, when a mixture of polyisocyanates is used as a starting material for the preparation of polyaziridines, a mixture of polyaziridine compounds is obtained. After the polyaziridine compound according to the present invention has been obtained, the polyaziridine compound according to the present invention can be isolated and the reaction product can be used without further purification, or the solvent used to prepare the polyaziridine compound can be removed from the composition obtained in the preparation of the polyaziridine compound according to the present invention. The amount of the polyaziridine compound according to the present invention in the crosslinker composition is typically at least 10% by weight, often typically at least 15% by weight and most typically at least 25% by weight relative to the total amount of the composition. Relative to the total amount of crosslinker composition, the amount of the polyaziridine compound according to the present invention in the crosslinker composition is preferably at least 60 % by weight, more preferably at least 80 % by weight, and most preferably at least 99 % by weight. The molecular weight of the polyaziridine compound is in the scope of 600 dalton to 5000 dalton in the crosslinker composition. Preferred molecular weight is as described above, and the molecular weight of the polyaziridine compound is measured using MALDI-TOF-MS as described in the experimental section hereinafter. MALDI-TOF-MS refers to matrix-assisted laser desorption ionization time-of-flight mass spectrometry.

[0096] The amount of aziridinyl-functional molecules having a molecular weight below 250 Daltons, more preferably below 350 Daltons, even more preferably below 450 Daltons, even more preferably below 550 Daltons and even more preferably below 580 Daltons present in the crosslinker composition according to the invention is preferably below 5 wt.-%, more preferably below 2 wt.-%, more preferably below 1 wt.-%, more preferably below 0.5 wt.-% and most preferably below 0.1 wt.-%, relative to the total weight of the crosslinker composition, wherein the molecular weight is determined using LC-MS as described in the experimental part below.

[0097] The average number of aziridinyl groups per aziridinyl-containing molecule in the composition is preferably at least 1.8, more preferably at least 2, more preferably at least 2.2, and preferably less than 10, more preferably less than 6, and most preferably less than 4. Most preferably, the average number of aziridinyl groups per aziridinyl-containing molecule in the composition is from 2.2 to 3. The calculated average amount of urethane bonds, relative to the total weight of the polyaziridine compounds according to the invention present in the crosslinker composition, is at least 5% by weight, more preferably at least 5.5% by weight, more preferably at least 6% by weight, more preferably at least 9% by weight, more preferably at least 12% by weight, and preferably less than 25% by weight, preferably less than 20% by weight.

[0098] In view of the potential water sensitivity of the polyaziridine compounds according to the present invention, the crosslinker composition preferably does not contain a substantial amount of water, and more preferably does not contain water. By "does not contain a substantial amount of water" is meant less than 15% by weight, preferably less than 5% by weight, more preferably less than 1% by weight, and most preferably less than 0.1% by weight. In view of the potential water sensitivity of the polyaziridine compounds according to the present invention, water is preferably not intentionally added to the composition (i.e., a small amount of water may be present in the compounds used to prepare the polyaziridine compounds according to the present invention).

[0099] The polyaziridine compounds according to the present invention preferably have a Brookfield viscosity at 25° C. of at least 10,000 mPa.s, more preferably at least 20,000 mPa.s, more preferably at least 50,000 mPa.s, preferably at most 1,000,000 mPa.s, more preferably at most 500,000 mPa.s, even more preferably at most 200,000 mPa.s at 25° C. As used herein, the Brookfield viscosity is determined according to ISO 2555-89. In an alternative embodiment, the viscosity of the polyaziridine is measured at 25° C. in an 80% solids solution in dimethylformamide (DMF) using a Brookfield with spindle S63. The viscosity as measured according to this method is preferably in the range of 300 mPa.s to 20,000 mPa.s, more preferably in the range of 500 mPa.s to 12,000 mPa.s, and most preferably in the range of 700 mPa.s to 3,000 mPa.s.

[0100] The polyaziridine compounds according to the invention or the crosslinker compositions comprising at least one polyaziridine compound as defined above can advantageously be used as crosslinkers for crosslinking carboxylic acid-functional polymers which are preferably dissolved and / or dispersed in an aqueous medium.

[0101] Another aspect of the present invention is a two-component coating system comprising a first component and a second component that are separate and distinct from each other, wherein the first component comprises a carboxylic acid-functional polymer dissolved and / or dispersed, preferably dispersed, in an aqueous medium, and wherein the second component comprises a polyaziridine compound as defined above or a crosslinker composition comprising at least one polyaziridine compound as defined above, wherein the first component and the second component are stored separately because the crosslinking reaction between the crosslinker and the polymer to be crosslinked can begin immediately after mixing the crosslinker with the aqueous composition of the polymer to be crosslinked. Immediately before applying the coating composition, the first and second components of the two-component system are mixed to obtain a coating composition comprising aziridine groups Q and carboxylic acid groups. Prior to combining with the second component, the pH of the first component is preferably at least 7, more preferably at least 7.5, even more preferably at least 8, and even more preferably at least 8.5.

[0102] The carboxylic acid functional polymer present in the first component of the two-component coating system contains carboxylic acid groups and / or carboxylate groups, and the carboxylic acid groups and / or carboxylate groups preferably do not contain covalent bonds that prevent these groups from chemically reacting with the aziridine moiety present in the polyaziridine compound. As used herein, the amount of carboxylic acid groups present in the carboxylic acid functional polymer is the total amount of deprotonated and protonated carboxylic acid groups present in the polymer to be crosslinked. Therefore, the amount of carboxylic acid groups present in the carboxylic acid functional polymer is the total amount of carboxylate groups and carboxylic acid groups present in the carboxylic acid functional polymer. The polymer to be crosslinked preferably contains carboxylate groups that are at least partially neutralized by a base. Preferably, at least some of the base is a volatile base. Preferably, at least some of the carboxylic acid groups present in the carboxylic acid functional polymer to be crosslinked undergo deprotonation to obtain carboxylate groups. Deprotonation is achieved by neutralizing the carboxylic acid functional polymer with a base. Examples of suitable bases are ammonia, secondary amines, tertiary amines, LiOH, NaOH and / or KOH. Examples of secondary and tertiary amines are as described above. Preferred bases are tertiary amines. Preferred tertiary amines are as described above. Most preferred is triethylamine.

[0103] The non-limiting example of cross-linkable carboxylic acid functional polymer is vinyl polymer (such as styrene-acrylic acid), (methyl) acrylic copolymer, vinyl acetate (to) polymer (such as vinyl acetate vinyl chloride ethylene polymer), polyurethane, condensation polymer (such as polyester, polyamide, polycarbonate), and the hybrid of any polymer in these polymers, wherein at least one polymer in two polymers has carboxylic acid functional group.Carboxylic acid functional polymer is preferably selected from the group consisting of the following: polyester, polycarbonate, polyamide, vinyl polymer, polyacrylate, polymethacrylate, poly-(acrylate-co-methacrylate), polyurethane, poly-(carbamate-co-acrylate), poly-(carbamate-co-methacrylate), poly-(carbamate-co-acrylate-co-methacrylate), poly-(carbamate-co-acrylate-co-methacrylate), polyurea and their mixture.Preferably, vinyl polymer means the polymer comprising the reaction residue of styrene and acrylate and / or methacrylate. In an embodiment of the present invention, the preferred crosslinkable carboxylic acid functional polymer is selected from the group consisting of vinyl polymers, polyacrylates, polymethacrylates, poly(acrylate-co-methacrylates) and mixtures thereof. In another embodiment, the carboxylic acid functional polymer is selected from the group consisting of polyurethanes, poly(urethane-co-acrylates), poly(urethane-co-methacrylates), poly(urethane-co-acrylates-co-methacrylates), polyureas and mixtures thereof. The present invention also relates to a coating composition obtained by mixing a first component and a second component of a two-component coating system just before applying the coating composition, wherein the coating composition comprises an amount of aziridinyl groups Q and carboxylic acid groups such that the stoichiometric amount (SA) of aziridinyl groups Q on the carboxylic acid groups is preferably from 0.1 to 2.0, more preferably from 0.2 to 1.5, even more preferably from 0.25 to 0.95, and most preferably from 0.3 to 0.8. The pH of the coating composition is preferably at least 7.5, more preferably at least 8, more preferably at least 8.5, even more preferably at least 9.

[0104] The present invention also relates to a substrate having a coating, the coating being obtained by: (i) applying a coating composition as described above to a substrate, and (ii) drying the coating composition by evaporating the volatiles. The coating composition is preferably dried at a temperature below 160°C, preferably below 90°C, more preferably below 50°C, and most preferably at ambient temperature. The coating composition according to the present invention can be applied to any type of substrate, such as wood, leather, concrete, textiles, plastics, vinyl flooring, glass, metal, ceramics, paper, wood-plastic composites, and fiberglass-reinforced materials. The thickness of the dried coating on the substrate is preferably 1 to 200 microns, more preferably 5 to 150 microns, and most preferably 15 to 90 microns. If the coating composition is an ink composition, the thickness of the dried ink is preferably 0.005 to 35 microns, more preferably 0.05 to 25 microns, and most preferably 4 to 15 microns.

[0105] The invention will now be illustrated by reference to the following examples. Unless otherwise indicated, all parts, percentages and ratios are by weight.

[0106] AV determination

[0107] The acid value (AV) of a sample's solid matter is determined based on ASTM D1639-90 (1996) e1. In this procedure, a sample dissolved in a good solvent is titrated with an alcoholic potassium hydroxide solution of known concentration (KOH). The difference in titration volume between the sample and the blank is a measure of the solid's acid value according to the following formula: AV = [(Vblank - Vsample)*N KOH *56.1] / (W*S / 100), where AV is the solid acid value in mg KOH / g solid material, Vblank is the volume of KOH solution used in the blank, Vsample is the volume of KOH solution used in the sample, and N KOH is the normality of the KOH solution, W is the sample weight in grams, and S is the solids content of the sample in %. The measurements were performed in duplicate using a potentiometric endpoint on a Metrohm 702SM Titrino titrator (the results were accepted if the difference between the duplicates was <0.1 mg KOH / g solid matter).

[0108] Chemical resistance

[0109] Chemical resistance test based on DIN 68861-1:2011-01.

[0110] Unless otherwise stated, chemical resistance testing is as follows:

[0111] The coating composition consisted of 0.9 stoichiometric amounts (SA) of total carboxylic acid reactive functional groups (e.g., aziridinyl) compared to the carboxylic acid functional groups. The coating composition was processed as described in the examples and then cast using a wire rod coater at a wet layer thickness of 100 μm. After casting, the film was dried at 25°C for 1 hour and then annealed at 50°C for 16 hours. Subsequently, a piece of cotton wool was soaked in 1:1 ethanol: demineralized water (by weight) and placed on the film for 60 minutes (unless otherwise stated). After removing the cotton wool and allowing it to recover overnight, the spots were scored according to the following scale:

[0112] 1 Complete coating degradation

[0113] 2 Structural damage to the coating

[0114] 3 Severe markings on the coating, visible from multiple directions

[0115] 4 Slight marks on the coating, visible from certain angles

[0116] 5 No marking or gloss change observed

[0117] Viscosity measurement:

[0118] Apparent viscosity was determined according to ISO 2555:2018. Measurements were performed at 23°C on a Brookfield DVE-LV viscometer (single cylinder geometry) at 60 rpm. A spindle was selected from S62, S63, or S64, using the lowest numbered spindle (i.e., the largest spindle) that produced a torque reading between 10% and 100%.

[0119] Analysis of low molecular weight fractions by LC-MS

[0120] LC system: Agilent 1290 Infinity II; Detector No. 1: Agilent 1290 Infinity IIPDA; Detector No. 2: Agilent iFunnel 6550Q-TOF-MS.

[0121] LC-MS analysis of the low molecular weight fraction was performed using the following procedure. A solution of approximately 100 mg / kg of material in methanol was prepared gravimetrically and stirred. 0.5 μl of this solution was injected into a UPLC equipped with ESI-TOF-MS detection. The column used was a 100 × 2.1 mm, 1.8 μm, Waters HSS T3 C18 column operated at 40°C. The flow rate was 0.5 ml / min. -1. The solvent used is 10mM NH4CH3COO aqueous solution (eluent A), acetonitrile (B) and THF (C) set to pH 9.0 with NH3. Two binary gradients from 80 / 20A / B to 1 / 99A / B and from 1 / 99A / B to 1 / 49 / 50A / B / C in 10 minutes are applied, after which the starting condition (80 / 20A / B) is applied. Assuming that all components have linear MS responses in all response ranges and that the ionization efficiency of all components is equal, the total ion current signal is integrated. In the case of coelution, the extracted ion chromatogram of the specific species is integrated. The integral signal of the specific low molecular weight peak is divided by the total integral sample signal to produce the score of the low molecular weight substance.

[0122] MALDI-ToF-MS

[0123] All MALDI-ToF-MS spectra are obtained using Bruker Ultraflextreme MALDI-ToF mass spectrometer. The instrument is equipped with an Nd:YAG laser and a collision cell (not used for these samples) emitted at 1064nm. Use a reflectron, use the highest resolution mode (scope of 60-7000m / z) providing accurate mass to obtain spectrum in positive ion mode. Use cesium triiodide (scope of 0.3-3.5kDa) to carry out mass calibration (calibration method: IAV molecular characterization, code MC-MS-05). The laser energy is 20%. Sample is dissolved in THF with approximately 50mg / mL. The matrix used is: DCTB (trans 2-[3-(4-tert-butylphenyl)-2-methyl-2-propenylidene] malononitrile), CAS number 300364-84-5. Prepare matrix solution by dissolving 20mg in 1mL THF.

[0124] Sodium iodide (NaI, CAS No. 7681-82-5) was used as the salt; 10 mg was dissolved in 1 ml of THF, and MeOH was added dropwise. The sample: matrix: salt ratio was 10:200:10 (μl). After mixing, 0.5 μl was spotted onto a MALDI plate and air-dried. The peak measured in the MALDI spectrum is the sodium adduct of the polyaziridine compound, and in the context of this specification, the molecular weight (MW) of the polyaziridine compound corresponds to MW = observed [M + M 阳离子 ]–M 阳离子 , where the observed [M+M 阳离子 ] is a MALDI-TOF MS peak, and M 阳离子 is the exact mass of the cation used to prepare the adduct (in this case, M of sodium 阳离子= 23.0 Da). Polyaziridine compounds can be identified by comparing the MW to the exact molecular mass of the theoretical structure (ie, the sum of the non-isotopic average atomic masses of its constituent atoms), using a maximum deviation of 0.6 Da.

[0125] Synthesis of waterborne polyurethane P1

[0126] A 1-liter flask (equipped with a thermometer and an overhead stirrer) was charged with 29.9 grams of dimethylolpropionic acid, 282.1 grams of polypropylene glycol (with a calculated average molecular weight (M) of 2000 Da and an OH number of 56 ± 2 mg KOH / g polypropylene glycol), 166.5 grams of polypropylene glycol (with a calculated average molecular weight (M) of 1000 Da and an OH number of 112 ± 2 mg KOH / g polypropylene glycol), and 262.8 grams of isophorone diisocyanate (the average molecular weight of each of the polyols was calculated from its OH number according to the following equation: M = 2 * 56100 / [OH number in mg KOH / g polypropylene glycol]. The reaction mixture was placed under an N2 atmosphere and heated to 50°C, after which 0.07 grams of dibutyltin dilaurate was added to the reaction mixture. An exothermic reaction was observed; however, appropriate measures were taken to prevent the reaction temperature from exceeding 97°C. The reaction was maintained at 95°C for one hour. The resulting polyurethane P1′ had an NCO content of 7.00% (theoretical 7.44%) based on solids, as determined according to ISO 14896, Method A (2009), and an acid number of 16.1 ± 1 mg KOH / g polyurethane P1′. Polyurethane P1′ was cooled to 60°C, 18.7 g of triethylamine was added, and the resulting mixture was stirred for 30 minutes. Subsequently, an aqueous dispersion of polyurethane P1′ (hereinafter referred to as P1) was prepared as follows: the thus-prepared mixture of polyurethane P1′ and triethylamine was added to a mixture of 1100 g of demineralized water, 19.5 g of nonylphenol ethoxylate (9 ethoxylate groups), and 4.0 g of triethylamine at room temperature over a period of 60 minutes. After the additions were complete, the mixture was stirred for an additional 5 minutes, after which 111.2 g of hydrazine (16 wt.% aqueous solution) was added. The aqueous dispersion of polyurethane P1′ thus prepared was stirred for an additional 1 h to obtain P1.

[0127] Genotoxicity testing

[0128] pass The genotoxicity of the Examples and Comparative Examples was evaluated using the ToxTracker assay (Toxys, Leiden, the Netherlands). The ToxTracker assay is a set of several validated green fluorescent protein (GFP)-based mouse embryonic stem (mES) reporter cell lines that can be used to identify the bioactivity and potential carcinogenicity of newly developed compounds in a single test. The method uses a two-step approach.

[0129] In a first step, a dose-ranging study was performed using wild-type mES cells (line B4418). 20 different concentrations of each compound were tested, starting with 10 mM in DMSO as the highest concentration, and 19 serial 2-fold dilutions.

[0130] Next, the genotoxicity of the Examples and Comparative Examples was assessed using specific genes linked to reporter genes for detecting DNA damage; the specific genes were Bscl2 (as described in US9695481B2 and EP2616484B1) and Rtkn (Hendriks et al., Toxicol. Sci. 2015, 150, 190-203) biomarkers. Genotoxicity was assessed at 10%, 25%, and 50% cytotoxicity in the absence and presence of a metabolic system based on rat S9 liver extract (aroclor1254-induced rats, Moltox, Boone, NC, USA). Independent cell lines were seeded into 96-well cell culture plates, and fresh ES cell culture medium containing diluted test substances was added to the cells 24 hours after the cells were seeded into the 96-well plates. For each compound tested, five concentrations were tested at 2-fold dilutions. The highest sample concentration induced significant cytotoxicity (50-70%). In the case of no or low cytotoxicity, 10 mM or the maximum soluble mixture concentration was used as the maximum test concentration.Cytotoxicity was determined by counting cells after 24 hours of exposure using a Guava easyCyte 10HT flow cytometer (Millipore).

[0131] GFP reporter gene induction is always compared with vehicle control treatment. For specific compounds, the DMSO concentration in all wells is similar and never exceeds 1%. All compounds were tested in at least three completely independent repeated experiments. All experiments included a positive control treatment (DNA damage) using cisplatin. Metabolism was assessed by adding S9 liver extract. In the presence of S9 and required cofactors (RegenSysA+B, Moltox, Boone, NC, USA), cells were exposed to five concentrations of test compounds for 3 hours. After washing, cells were incubated in fresh ES cell culture medium for 24 hours. After 24 hours of exposure, the induction of the GFP reporter gene was determined using a Guava easyCyte 10HT flow cytometer (Millipore). Only the GFP expression in complete individual cells was determined. The average GFP fluorescence and cell concentration in each well were measured and used for cytotoxicity assessment. Data were analyzed using ToxPlot software (Toxys, Leiden, the Netherlands). Induction levels reported are at compound concentrations that induce 10%, 25% and 50% cytotoxicity after a 3-hour exposure and 24-hour recovery in the presence of S9 rat liver extract or alternatively a 24-hour exposure in the absence of S9 rat liver extract.

[0132] A positive induction level of a biomarker is defined as equal to or higher than 2-fold induction at at least one of 10%, 25% and 50% cytotoxicity in the absence or presence of a metabolic system rat S9 liver extract; a weak positive induction is defined as higher than 1.5-fold and lower than 2-fold induction at at least one of 10%, 25% and 50% cytotoxicity in the absence or presence of a metabolic system rat S9 liver extract (but lower than 2-fold at 10%, 25% and 50% cytotoxicity), and a negative induction is defined as lower than or equal to 1.5-fold induction at 10%, 25% and 50% cytotoxicity in the absence or presence of a metabolic system based on rat S9 liver extract.

[0133] Components and abbreviations used:

[0134] Dimethylformamide (CAS No. 68-12-2) was obtained from cros Organics (a subsidiary of Thermo Fisher Scientific).

[0135] Di(propylene glycol) dimethyl ether (Proglyde DMM, CAS No. 111109-77-4) was obtained from Dow Inc

[0136] Trimethylolpropane tris(2-methyl-1-aziridine propionate), CAS No. 64265-57-2, CX-100 was obtained from DSM.

[0137] Isobutylene oxide (CAS No. 558-30-5) was obtained from Alfa Aesar (a subsidiary of Thermo Fisher Scientific).

[0138] Isoprene monooxide (2-methyl-2-vinyloxirane, CAS No. 1838-94-4) was obtained from Acros (a subsidiary of Thermo Fisher Scientific).

[0139] 2-Methylaziridine (propylene imine, CAS No. 75-55-8) was obtained from Menadiona SL. (Palafolls, Spain).

[0140] Potassium carbonate (CAS No. 584-08-7) was obtained from Alfa Aesar (a subsidiary of Thermo Fisher Scientific).

[0141] Polyethylene glycol monomethyl ether (CAS No.: 9004-74-4) with a number average molecular weight of 500 Da was obtained from Acros Organics (a subsidiary of Thermo Fisher Scientific).

[0142] IPDI (5-isocyanato-1-(isocyanatomethyl)-1,3,3-trimethylcyclohexane, I, isophorone diisocyanate, CAS No. 4098-71-9) was obtained from Covestro.

[0143] N3600 and N3900 was obtained from Covestro.

[0144] XTJ-436 (CAS No. 118270-87-4) was obtained from Huntsman.

[0145] Bismuth neodecanoate (CAS No. 34364-26-6) was obtained from TIB chemicals AG (Mannheim, Germany).

[0146] Hydrazine (16% aqueous solution, CAS No. 302-01-2) was obtained from Honeywell.

[0147] Dimethylolpropionic acid (DMPA, CAS No. 4767-03-7) was obtained from Perstop Polyols.

[0148] Triethylamine (TEA, CAS No. 121-44-8) was obtained from Arkema

[0149] Dibutyltin dilaurate (CAS No. 77-58-7) was obtained from Sigma-Aldrich.

[0150] Polypropylene glycols with a number average molecular weight of 1000 Da and a number average molecular weight of 2000 Da were obtained from BASF.

[0151] Sodium lauryl sulfate (30% aqueous solution, CAS No. 73296-89-6) was obtained from BASF.

[0152] Methyl methacrylate (CAS No. 80-62-6) was obtained from Lucite Int.

[0153] n-Butyl acrylate (CAS No. 141-32-2) was obtained from Dow Chemical.

[0154] Methacrylic acid (CAS No. 79-41-4) was obtained from Lucite Int.

[0155] Ammonium persulfate (CAS No. 7727-54-0) was obtained from United Initiators.

[0156] Ammonia (25% aqueous solution, CAS No. 1336-21-6) was obtained from Merck.

[0157] 1-Butanol (CAS No. 71-36-3) was obtained from Sigma-Aldrich.

[0158] Comparative Example 1

[0159] Comparative Example 1 is CX-100, trimethylolpropane tris(2-methyl-1-aziridine propionate), the chemical structure of which is shown below.

[0160]

[0161] As a reference, the performance of trimethylolpropane tris(2-methyl-1-aziridine propionate) as a crosslinker was evaluated using a spot test on the coating surface based on the procedure from the DIN 68861-1:2011-01 standard. For these tests, 0.23 parts of the compound were mixed with 0.60 parts of Proglyde TMDMM (dipropylene glycol dimethyl ether, a mixture of isomers) was mixed and incubated at 80°C for 10 minutes under regular stirring. Subsequently, 0.56 parts of the resulting solution were added to 20 parts of P1 under continuous stirring, and the resulting mixture was further stirred for 30 minutes. The coating composition was then filtered and applied to a Leneta test card using a 100 μm wire applicator (test C1-1). The film was dried at 25°C for 16 hours, then annealed at 50°C for 1 hour and further dried at 25°C for 24 hours. Subsequently, a piece of cotton wool was immersed in 1:1 EtOH: demineralized water and placed on the film at various time intervals. After removing EtOH and recovering for 60 minutes, the following results were obtained (score 1 indicates complete degradation of the film, 5 indicates no visible damage):

[0162]

[0163] Genotoxicity testing

[0164]

[0165] The results of the genotoxicity test showed that the cross-linking agent of Comparative Example 1 was genotoxic.

[0166] Example 1

[0167] A round-bottom flask equipped with a condenser was placed under a N atmosphere and charged with propylene imine (10.02 g), isobutylene oxide (10.04 g) and KCO (0.50 g) and heated to 55° C., after which the mixture was stirred at T = 55° C. for 96 h. After filtration, excess PI was removed in vacuo, followed by further purification by vacuum distillation to obtain a colorless, low-viscosity liquid.

[0168] 5.78 g of the resulting material (2-methyl-1-(2-methylaziridin-1-yl)propan-2-ol) was charged to the feeding funnel along with 7.91 g of dimethylformamide. This mixture was fed over 15 minutes to a 9.00 g flask equipped with a thermometer and filled with water heated to 50°C. A mixture of N3600, 37.29 g of DMF and 0.02 g of bismuth neodecanoate was added to a reaction flask while stirring the mixture with a mechanical overhead stirrer under a nitrogen atmosphere. After the addition was complete, the mixture was further heated to 80°C. Samples were taken at regular intervals and the reaction progress was monitored using a Bruker Alpha FT-IR spectrometer until the peak at 2200-2300 cm -1The mixture was stirred for 2 hours until no NCO stretching change was observed. 0.29 g of 1-butanol was then added to the mixture, followed by further reaction until the NCO stretching peak completely disappeared. The solution was concentrated in vacuo to a 25 wt% solution, yielding a slightly viscous liquid.

[0169] The calculated molecular weight of the theoretical main component is 891.62 Da, and the chemical structure is shown below.

[0170]

[0171] The molecular weight was confirmed by Maldi-TOF-MS: calculated [M+Na+] = 914.62 Da; observed [M+Na+] = 914.67 Da.

[0172] The following components with masses below 580 Da were determined and quantified by LC-MS:

[0173]

[0174] is present in the composition at less than 0.01% by weight, and

[0175]

[0176] Present in less than 0.01 wt%.

[0177] The performance of the synthesized compound as a crosslinking agent was evaluated using a spot test on the coating surface based on the process from DIN 68861-1:2011-01 standard. For these tests, 1.4 parts of crosslinker solution were added to 10 parts of P1 under continuous stirring, and the resulting mixture was further stirred for 30 minutes. Then, the coating composition was filtered and applied to a Leneta test card using a 100 μm wire coater (test 1-1). As a reference, a film was cast from the same composition lacking a crosslinking agent (test 1-2). The film was dried at 25 ° C for 16 hours, then annealed at 50 ° C for 1 hour, and further dried at 25 ° C for 24 hours. Subsequently, a piece of cotton wool was immersed in 1: 1 EtOH: demineralized water, and various time intervals were placed on the film. After removing EtOH and recovering for 60 minutes, the following results were obtained (score 1 indicates complete degradation of the film, and 5 indicates no visible damage):

[0178]

[0179]

[0180] Genotoxicity testing

[0181]

[0182] The results of the genotoxicity test showed that the cross-linker composition of Example 1 only had weak positive induced genotoxicity.

[0183] Example 2

[0184] The (2-methyl-1-(2-methylaziridin-1-yl)propan-2-ol) intermediate was synthesized as described in Example 1.

[0185] 11.46 g of the substance (2-methyl-1-(2-methylaziridin-1-yl)propan-2-ol) was placed in the feeding funnel along with 25.2 g of dimethylformamide. This mixture was fed over 30 minutes to a 22.8 g flask equipped with a thermometer and filled with water heated to 50°C. In a reaction flask containing a mixture of N 3600, 72.0 g of DMF and 0.002 g of bismuth neodecanoate, the mixture was stirred with a mechanical overhead stirrer under a nitrogen atmosphere. After the feeds were complete, a mixture of 12.9 g of poly(ethylene glycol) monomethyl ether having an average Mn of 500 Da and 39.6 g of DMF was added to the reaction mixture and stirred at 50° C. for 2 hours. Samples were taken at regular intervals and the progress of the reaction was monitored using a Bruker Alpha FT-IR spectrometer until the peak at 2200-2300 cm -1 The reaction mixture was stirred for 2 hours until no NCO stretching change was observed. Subsequently, 0.48 g of 1-butanol and 4.8 g of DMF were added to the mixture, followed by further reaction until the NCO stretching peak disappeared completely. The reaction product was a slightly viscous 25 wt% solution of the crosslinker in DMF.

[0186] The calculated molecular weights of the theoretical main components are 891.62 Da (three aziridines), 1190.76 Da (two aziridines, 9 EG repeating units), 1234.79 Da (two aziridines, 10 EG repeating units) and 1278.81 Da (two aziridines, 11 EG repeating units), and the chemical structures are shown below.

[0187]

[0188] The molecular weight was confirmed by Maldi-TOF-MS: calculated [M+Na+] = 914.62 Da; observed [M+Na+] = 914.47 Da.

[0189]

[0190] The molecular weight was confirmed by Maldi-TOF-MS: calculated [M+Na+] = 1213.76 Da; observed [M+Na+] = 1213.59 Da.

[0191]

[0192] The molecular weight was confirmed by Maldi-TOF-MS: calculated [M+Na+] = 1257.79 Da; observed [M+Na+] = 1257.63 Da.

[0193]

[0194] The molecular weight was confirmed by Maldi-TOF-MS: calculated [M+Na+] = 1301.81 Da; observed [M+Na+] = 1301.67 Da.

[0195] The following components with masses below 580 Da were determined and quantified by LC-MS:

[0196]

[0197] is present in the composition at less than 0.01% by weight, and

[0198]

[0199] Present in less than 0.01 wt%.

[0200] The performance of the synthesized compound as a crosslinking agent was evaluated using a spot test on the coating surface based on the process from DIN 68861-1:2011-01 standard. For these tests, 0.8 parts of crosslinker solutions were added to 15 parts of P1 under continuous stirring, and the resulting mixture was further stirred for 30 minutes. Then, the coating composition was filtered and applied to a Leneta test card using a 100 μm wire coater (test 2-1). As a reference, a film was cast from the same composition lacking a crosslinking agent (test 2-2). The film was dried at 25°C for 16 hours, then annealed at 50°C for 1 hour, and further dried at 25°C for 24 hours. Subsequently, a piece of cotton wool was immersed in 1:1 EtOH: demineralized water, and various time intervals were placed on the film. After removing EtOH and recovering for 60 minutes, the following results were obtained (score 1 indicates complete degradation of the film, and 5 indicates no visible damage):

[0201]

[0202] The water-based acrylic adhesive was synthesized as follows.

[0203] A 2 L, four-necked flask equipped with a thermometer and overhead stirrer was charged with sodium lauryl sulfate (30% solids in water, 18.6 g solution) and demineralized water (711 g). The reactor phase was placed under an N2 atmosphere and heated to 82°C. A mixture of demineralized water (112 g), sodium lauryl sulfate (30% solids in water, 37.2 g solution), methyl methacrylate (174.41 g), n-butyl acrylate (488.44 g), and methacrylic acid (34.88 g) was placed in a large feed funnel and emulsified with an overhead stirrer (monomer feed). Ammonium persulfate (1.75 g) was dissolved in demineralized water (89.61 g) and placed in a small feed funnel (initiator feed). Ammonium persulfate (1.75 g) was dissolved in demineralized water (10.5 g) and this solution was added to the reactor phase. Immediately thereafter, 5% by volume of the monomer feed was added to the reactor phase. The reaction mixture was then allowed to exotherm to 85°C and held at 85°C for 5 minutes. The remaining monomer feed and initiator feed were then fed to the reaction mixture over 90 minutes, maintaining the temperature at 85°C. After the feeds were complete, the monomer feed funnel was rinsed with demineralized water (18.9 g), and the reaction temperature was maintained at 85°C for 45 minutes. The mixture was then cooled to room temperature and adjusted to pH 7.2 with ammonia solution (6.25 wt% in demineralized water) and to 40% solids with additional demineralized water.

[0204] For further spot test, under continuous stirring, 1.6 parts of crosslinker solution were added to 15 parts of the above-mentioned aqueous polyacrylate adhesive, and the resulting mixture was further stirred for 30 minutes. Then, the coating composition was filtered and applied to a Leneta test card using a 100 μm wire coater (test 2-3). As a reference, a film was also cast from the same composition lacking a crosslinker (test 2-4). The film was dried at 25°C for 1 hour, then annealed at 50°C for 16 hours, and further dried at 25°C for 24 hours. Subsequently, a piece of cotton wool was immersed in 1:1 EtOH: demineralized water and placed at various time intervals on the film. After removing EtOH and recovering for 60 minutes, the following results were obtained (score 1 indicates complete degradation of the film, 5 indicates no visible damage):

[0205]

[0206] Genotoxicity testing

[0207]

[0208]

[0209] The results of the genotoxicity test showed that the cross-linker composition of Example 2 only had weak positive induced genotoxicity.

[0210] Example 3

[0211] A round-bottom flask equipped with a condenser was placed under a N atmosphere and charged with propylene imine (25.2 g), 2-methyl-2-vinyl oxirane (24.7 g) and KCO (2.00 g) and heated to 70° C., after which the mixture was stirred for 90 h at T = 70° C. After filtration, excess PI was removed in vacuo, followed by further purification by vacuum distillation to obtain a colorless, low-viscosity liquid.

[0212] 3.30 g of the resulting material (2-methyl-1-(2-methylaziridin-1-yl)but-3-en-2-ol) was placed in a feeding funnel along with 11.0 g of dimethylformamide. This mixture was fed over 15 minutes to a 6.00 g flask equipped with a thermometer and filled with water heated to 50°C. N3600, 22.0 g of DMF and 0.12 g of bismuth neodecanoate were added to a reaction flask while stirring the mixture with a mechanical overhead stirrer under a nitrogen atmosphere. After the feeds were complete, a mixture of 3.24 g of poly(ethylene glycol) monomethyl ether having an average Mn of 500 Da and 5.5 g of DMF was added to the reaction mixture and stirred at 50° C. for 2 hours. Samples were taken at regular intervals and the reaction progress was monitored using a Bruker Alpha FT-IR spectrometer until the peak at 2200-2300 cm -1 The reaction mixture was stirred for 2 hours until no NCO stretching change was observed. Subsequently, 0.19 g of 1-butanol was added to the mixture, followed by further reaction until the NCO stretching peak disappeared completely. The reaction product was a slightly viscous 25 wt% solution of the crosslinker in DMF.

[0213] The calculated molecular weights of the theoretical main components are 941.63 Da (three aziridines), 1214.76 Da (two aziridines, 9EG repeating units), 1258.79 Da (two aziridines, 10EG repeating units) and 1302.81 Da (two aziridines, 11EG repeating units), and the chemical structures are shown below.

[0214]

[0215] The molecular weight was confirmed by Maldi-TOF-MS: calculated [M+Na+] = 950.61 Da; observed [M+Na+] = 950.47 Da.

[0216]

[0217] The molecular weight was confirmed by Maldi-TOF-MS: calculated [M+Na+] = 1237.76 Da; observed [M+Na+] = 1237.56 Da.

[0218]

[0219] The molecular weight was confirmed by Maldi-TOF-MS: calculated [M+Na+] = 1281.79 Da; observed [M+Na+] = 1281.59 Da.

[0220]

[0221] The molecular weight was confirmed by Maldi-TOF-MS: calculated [M+Na+] = 1325.81 Da; observed [M+Na+] = 1325.61 Da.

[0222] The following components with masses below 580 Da were determined and quantified by LC-MS:

[0223]

[0224] is present in the composition at less than 0.01% by weight, and

[0225]

[0226] Present in less than 0.01 wt%.

[0227] The performance of the synthesized compound as a crosslinking agent was evaluated using a spot test on the coating surface based on the process from DIN 68861-1:2011-01 standard. For these tests, 1.1 parts of crosslinker solution were added to 10 parts of P1 under continuous stirring, and the resulting mixture was further stirred for 30 minutes. Then, the coating composition was filtered and applied to a Leneta test card using a 100 μm wire coater (test 3-1). As a reference, a film was cast from the same composition lacking a crosslinking agent (test 3-2). The film was dried at 25 ° C for 16 hours, then annealed at 50 ° C for 1 hour, and further dried at 25 ° C for 24 hours. Subsequently, a piece of cotton wool was immersed in 1: 1 EtOH: demineralized water and placed at various time intervals on the film. After removing EtOH and recovering for 60 minutes, the following results were obtained (score 1 indicates complete degradation of the film, and 5 indicates no visible damage):

[0228]

[0229] Genotoxicity testing

[0230]

[0231] The results of the genotoxicity test showed that the cross-linker composition of Example 3 only had weak positive induced genotoxicity.

[0232] Example 4

[0233] The 2-methyl-1-(2-methylaziridin-1-yl)but-3-en-2-ol intermediate was synthesized as described in Example 3.

[0234] 3.30 g of 2-methyl-1-(2-methylaziridin-1-yl)but-3-en-2-ol and 13.75 g of dimethylformamide were placed in the feeding funnel. This mixture was fed over 15 minutes into a 6.00 g flask equipped with a thermometer and filled with water heated to 50°C. N 3600, 27.5 g DMF and 0.12 g bismuth neodecanoate in a reaction flask while stirring the mixture with a mechanical overhead stirrer under nitrogen. After the feeds were complete, 6.52 g of A mixture of XTJ-436 (CAS No. 118270-87-4, obtained from Huntsman) and 6.88 g of DMF was added to the reaction mixture and stirred at 50° C. for 2 hours. Samples were taken at regular intervals and the reaction progress was monitored using a Bruker Alpha FT-IR spectrometer until the peak at 2200-2300 cm -1 The reaction mixture was stirred for 2 hours until no NCO stretching change was observed. Subsequently, 0.19 g of 1-butanol was added to the mixture, followed by further reaction until the NCO stretching peak disappeared completely. The reaction product was a slightly viscous 25 wt% solution of the crosslinker in DMF.

[0235] The calculated molecular weights of the theoretical main components are 941.63Da (three aziridines), 1644.16Da (two aziridines, 11PG repeating units), 1702.20Da (two aziridines, 12PG repeating units) and 1760.24Da (two aziridines, 13PG repeating units), and the chemical structures are shown below.

[0236]

[0237] The molecular weight was confirmed by Maldi-TOF-MS: calculated [M+Na+] = 950.61 Da; observed [M+Na+] = 950.49 Da.

[0238]

[0239] The molecular weight was confirmed by Maldi-TOF-MS: calculated [M+Na+] = 1667.16 Da; observed [M+Na+] = 1666.97 Da.

[0240]

[0241] The molecular weight was confirmed by Maldi-TOF-MS: calculated [M+Na+] = 1725.20 Da; observed [M+Na+] = 1725.01 Da.

[0242]

[0243] The molecular weight was confirmed by Maldi-TOF-MS: calculated [M+Na+] = 1783.24 Da; observed [M+Na+] = 1783.08 Da.

[0244] The following components with masses below 580 Da were determined and quantified by LC-MS:

[0245]

[0246] is present in the composition at less than 0.01% by weight, and

[0247]

[0248] Present in less than 0.01 wt%.

[0249] The performance of the synthesized compound as a crosslinking agent was evaluated using a spot test on the coating surface based on the process from DIN 68861-1:2011-01 standard. For these tests, 1.4 parts of crosslinker solution were added to 10 parts of P1 under continuous stirring, and the resulting mixture was further stirred for 30 minutes. Then, the coating composition was filtered and applied to a Leneta test card using a 100 μm wire coater (test 4-1). As a reference, a film was cast from the same composition lacking a crosslinking agent (test 4-2). The film was dried at 25 ° C for 16 hours, then annealed at 50 ° C for 1 hour, and further dried at 25 ° C for 24 hours. Subsequently, a piece of cotton wool was immersed in 1: 1 EtOH: demineralized water and placed at various time intervals on the film. After removing EtOH and recovering for 60 minutes, the following results were obtained (score 1 indicates complete degradation of the film, 5 indicates no visible damage):

[0250]

[0251] Genotoxicity testing

[0252]

[0253] The results of the genotoxicity test showed that the crosslinker composition of Example 4 was non-genotoxic.

[0254] Example 5

[0255] The 2-methyl-1-(2-methylaziridin-1-yl)but-3-en-2-ol intermediate was synthesized as described in Example 3.

[0256] 5.09 g of 2-methyl-1-(2-methylaziridin-1-yl)but-3-en-2-ol and 25.50 g of dimethylformamide were placed in the feeding funnel. This mixture was fed over 15 minutes into a 7.00 g flask equipped with a thermometer and filled with water heated to 50°C. In a reaction flask, a mixture of 3600 N 35.0 g DMF and 0.02 g bismuth neodecanoate was added while stirring the mixture with a mechanical overhead stirrer under a nitrogen atmosphere. After the addition was complete, the reaction mixture was stirred at 50° C. for 2 hours. Samples were taken at regular intervals and the progress of the reaction was monitored using a Bruker Alpha FT-IR spectrometer until the peak at 2200-2300 cm -1 The reaction mixture was stirred for 10 minutes until no NCO stretching change was observed. Subsequently, a solution of 0.23 g of 1-butanol in 3.5 g of DMF was added to the mixture, followed by further reaction until the NCO stretching peak completely disappeared. The reaction product was a slightly viscous 15 wt% solution of the crosslinker in DMF.

[0257] The calculated molecular weight of the theoretical main component is 941.63 Da, and the chemical structure is shown below.

[0258]

[0259] The molecular weight was confirmed by Maldi-TOF-MS: calculated [M+Na+] = 950.61 Da; observed [M+Na+] = 950.71 Da.

[0260] The following components with masses below 580 Da were determined and quantified by LC-MS:

[0261]

[0262] is present in the composition at 0.011% by weight, and

[0263]

[0264] Present in less than 0.01 wt%.

[0265] The performance of the synthesized compound as a crosslinking agent was evaluated using a spot test on the coating surface based on the process from DIN 68861-1:2011-01 standard. For these tests, 0.7 parts of crosslinking agent solutions were added to 20 parts of P1 under continuous stirring, and the resulting mixture was further stirred for 30 minutes. Then, the coating composition was filtered and applied to a Leneta test card using a 100 μm wire applicator (test 5-1). As a reference, a film was cast from the same composition lacking a crosslinking agent (test 5-2). The film was dried at 25°C for 16 hours, then annealed at 50°C for 1 hour, and further dried at 25°C for 24 hours. Subsequently, a piece of cotton wool was immersed in 1:1 EtOH: demineralized water and placed at various time intervals on the film. After removing EtOH and recovering for 60 minutes, the following results were obtained (score 1 indicates complete degradation of the film, and 5 indicates no visible damage):

[0266]

[0267]

[0268] The water-based acrylic adhesive was synthesized as follows.

[0269] A 2 L, four-necked flask equipped with a thermometer and overhead stirrer was charged with sodium lauryl sulfate (30% solids in water, 18.6 g solution) and demineralized water (711 g). The reactor phase was placed under an N2 atmosphere and heated to 82°C. A mixture of demineralized water (112 g), sodium lauryl sulfate (30% solids in water, 37.2 g solution), methyl methacrylate (174.41 g), n-butyl acrylate (488.44 g), and methacrylic acid (34.88 g) was placed in a large feed funnel and emulsified with an overhead stirrer (monomer feed). Ammonium persulfate (1.75 g) was dissolved in demineralized water (89.61 g) and placed in a small feed funnel (initiator feed). Ammonium persulfate (1.75 g) was dissolved in demineralized water (10.5 g) and this solution was added to the reactor phase. Immediately thereafter, 5% by volume of the monomer feed was added to the reactor phase. The reaction mixture was then allowed to exotherm to 85°C and held at 85°C for 5 minutes. The remaining monomer feed and initiator feed were then fed to the reaction mixture over 90 minutes, maintaining the temperature at 85°C. After the feeds were complete, the monomer feed funnel was rinsed with demineralized water (18.9 g), and the reaction temperature was maintained at 85°C for 45 minutes. The mixture was then cooled to room temperature and adjusted to pH 7.2 with ammonia solution (6.25 wt% in demineralized water) and to 40% solids with additional demineralized water.

[0270] For further spot test, the performance of the synthesized compound as a crosslinking agent was evaluated using the spot test on the coating surface based on the procedure from DIN 68861-1:2011-01 standard. For these tests, 1.3 parts of crosslinker solution were added to 20 parts of the above-mentioned acrylic adhesives under continuous stirring, and the resulting mixture was further stirred for 30 minutes. Then, the coating composition was filtered and applied to a Leneta test card using a 100 μm wire coater (test 5-3). As a reference, a film was also cast from the same composition lacking a crosslinking agent (test 5-4). The film was dried at 25 ° C for 16 hours, then annealed at 50 ° C for 1 hour, and further dried at 25 ° C for 24 hours. Subsequently, a piece of cotton wool was immersed in 1: 1 EtOH: demineralized water and placed at various time intervals on the film. After removing EtOH and recovering for 60 minutes, the following results were obtained (score 1 indicates complete degradation of the film, and 5 indicates no visible damage):

[0271]

[0272] Genotoxicity testing

[0273]

[0274] The results of the genotoxicity test showed that the cross-linker composition of Example 5 only had weak positive induced genotoxicity.

Claims

1. A polyaziridine compound, comprising: a) 2 to 6 of the following structural units (A): in R1 is H, R2 and R4 are independently selected from H or an aliphatic hydrocarbon group containing 1 to 4 carbon atoms, R3 is an aliphatic hydrocarbon group containing 1 to 4 carbon atoms, R'=H or an aliphatic hydrocarbon group containing 1 to 4 carbon atoms; R" and R'" are independently selected from an aliphatic hydrocarbon group containing 1 to 4 carbon atoms, an alicyclic hydrocarbon group containing 4 to 12 carbon atoms, or an aromatic hydrocarbon group containing 6 to 12 carbon atoms, or R' and R" are part of the same saturated alicyclic hydrocarbon radical containing 4 to 8 carbon atoms, optionally containing heteroatoms, or R" and R'" are part of the same saturated alicyclic hydrocarbon radical containing 4 to 8 carbon atoms, optionally containing heteroatoms, b) one or more connecting chains, wherein each of these connecting chains connects two structural units A in the structural unit A, wherein the connecting chain is defined as the shortest chain of consecutive atoms connecting two structural units A; c) a molecular weight in the range of 600 Daltons to 5000 Daltons, wherein the molecular weight is determined using MALDI-TOF mass spectrometry; and d) one or more linking groups, wherein each of these linking groups connects two structural units A in the structural unit A, wherein the linking group consists of at least one functional group selected from the group consisting of: aliphatic hydrocarbon functional group, alicyclic hydrocarbon functional group, aromatic hydrocarbon functional group, isocyanurate functional group, iminooxadiazinedione functional group, ether functional group, ester functional group, amide functional group, carbonate functional group, carbamate functional group, urea functional group, biuret functional group, allophanate functional group, uretdione functional group and any combination thereof.

2. The polyaziridine compound according to claim 1, wherein R2 is H, R3 is CH3, and R4 is H.

3. The polyaziridine compound according to claim 1, wherein R2 is H, R3 is CH3, and R4 is CH3.

4. The polyaziridine compound according to any one of claims 1 to 3, wherein R'=H; R" and R'" are aliphatic hydrocarbon groups containing 1 to 4 carbon atoms.

5. The polyaziridine compound according to any one of claims 1 to 3, wherein R'=H; R" and R'" are aliphatic hydrocarbon groups containing 1 to 2 carbon atoms.

6. The polyaziridine compound according to any one of claims 1 to 3, wherein R'=H; R" and R'" are CH3. 7 . The polyaziridine compound according to claim 1 , wherein the polyaziridine compound contains 2 or 3 structural units (A).

8. The polyaziridine compound according to any one of claims 1 to 3, wherein the connecting chain consists of 4 to 300 atoms, and the connecting chain is a collection of covalently linked atoms consisting of i) carbon atoms, ii) carbon and nitrogen atoms, or iii) carbon, oxygen, and nitrogen atoms.

9. The polyaziridine compound according to any one of claims 1 to 3, wherein the polyaziridine compound has a molecular weight of 840 to 3800 Daltons, wherein the molecular weight is determined using MALDI-TOF mass spectrometry.

10. The polyaziridine compound according to any one of claims 1 to 3, wherein the linking group of the polyaziridine compound consists of at least one functional group selected from the group consisting of: Aliphatic hydrocarbon functional groups, alicyclic hydrocarbon functional groups, aromatic hydrocarbon functional groups, isocyanurate functional groups, iminooxadiazinedione functional groups, carbamate functional groups, urea functional groups, biuret functional groups, and any combination thereof.

11. The polyaziridine compound according to any one of claims 1 to 3, wherein the linking group consists of (i) at least two aliphatic hydrocarbon functional groups or at least two alicyclic hydrocarbon functional groups and (ii) an isocyanurate functional group or an iminooxadiazinedione functional group, and wherein a pendant group is present on the linking group, wherein the pendant group has the following structural formula: n' is the number of repeating units and is an integer from 1 to 50, X is O or NH, In each repeating unit, R7 and R8 are independently H or CH3, R9 is an aliphatic hydrocarbon group or an alicyclic hydrocarbon group, and R 10 Contains up to 20 carbon atoms and is an aliphatic hydrocarbon group, an alicyclic hydrocarbon group, or an aromatic hydrocarbon group, or a combination thereof.

12. The polyaziridine compound according to any one of claims 1 to 3, wherein the linking group consists of (i) at least two aliphatic hydrocarbon functional groups or at least two alicyclic hydrocarbon functional groups and (ii) an isocyanurate functional group or an iminooxadiazinedione functional group, and wherein a pendant group is present on the linking group, wherein the pendant group has the following structural formula: n' is the number of repeating units and is an integer from 1 to 50, X is O, In each repeating unit, R7 and R8 are independently H, R9 is an aliphatic hydrocarbon group or an alicyclic hydrocarbon group, and R 10 Contains up to 20 carbon atoms and is an aliphatic hydrocarbon group, an alicyclic hydrocarbon group, or an aromatic hydrocarbon group, or a combination thereof.

13. The polyaziridine compound according to any one of claims 1 to 3, wherein the linking group consists of (i) at least two aliphatic hydrocarbon functional groups or at least two alicyclic hydrocarbon functional groups and (ii) an isocyanurate functional group or an iminooxadiazinedione functional group, and wherein a pendant group is present on the linking group, wherein the pendant group has the following structural formula: n' is the number of repeating units and is an integer from 1 to 50, X is O or NH, In each repeating unit, R7 and R8 are independently H or CH3, R9 is an aliphatic hydrocarbon group or an alicyclic hydrocarbon group, R 10 contains up to 20 carbon atoms and is an aliphatic, alicyclic or aromatic hydrocarbon group, or a combination thereof, and The polyaziridine compound contains two structural units (A). 14 . The polyaziridine compound according to claim 1 , wherein the polyaziridine compound contains a polyoxyethylene group in an amount of at least 0.1% by weight and in an amount of less than 45% by weight relative to the polyaziridine compound.

15. The polyaziridine compound according to any one of claims 1 to 3, wherein the polyaziridine compound is obtained by reacting at least a polyisocyanate with a compound B having the following structural formula: wherein the molar ratio of compound B to polyisocyanate is from 2 to 6, and wherein R′, R″, R′″, R1, R2, R3 and R4 are as defined in any one of claims 1 to 3.

16. The polyaziridine compound according to any one of claims 1 to 3, wherein the polyaziridine compound is obtained by reacting at least a polyisocyanate with a compound B having the following structural formula: wherein the molar ratio of compound B to polyisocyanate is from 2 to 6, and wherein R', R", R'", R1, R2, R3 and R4 are as defined in any one of claims 1 to 3; and The compound B is obtained by reacting at least a non-OH functional monoepoxide compound with an aziridine compound having the following structural formula: wherein R1, R2, R3 and R4 are as defined in any one of claims 1 to 3.

17. The polyaziridine compound according to any one of claims 1 to 3, wherein the polyaziridine compound is obtained by reacting at least a polyisocyanate with a compound B having the following structural formula: wherein the molar ratio of compound B to polyisocyanate is from 2 to 6, and wherein R′, R″, R′″, R1, R2, R3 and R4 are as defined in any one of claims 1 to 3; The compound B is obtained by reacting at least a non-OH functional monoepoxide compound with an aziridine compound having the following structural formula: wherein R1, R2, R3 and R4 are as defined in any one of claims 1 to 3; and The non-OH-functional monoepoxide compound is 2,2-dimethyloxirane. 18 . A crosslinker composition comprising at least one polyaziridine compound according to claim 1 and further comprising at least one additional component.

19. The crosslinker composition according to claim 18, wherein the molecular weight of the polyaziridine compound according to any one of claims 1 to 17 present in the crosslinker composition is in the range of 600 Daltons to 5000 Daltons, wherein the molecular weight is determined using MALDI-TOF mass spectrometry.

20. The crosslinker composition of claim 18, wherein the amount of aziridinyl-functional molecules having a molecular weight below 580 Daltons is less than 5 wt%, relative to the total weight of the crosslinker composition, wherein the molecular weight is determined using LC-MS.

21. The crosslinker composition of claim 18, wherein the crosslinker composition contains less than 5% by weight water.

22. Use of the polyaziridine compound according to any one of claims 1 to 17 or the crosslinker composition according to any one of claims 18 to 21 for crosslinking a carboxylic acid-functional polymer dissolved and / or dispersed in an aqueous medium, wherein the carboxylic acid-functional polymer comprises carboxylic acid groups and / or carboxylate groups.

23. A two-component coating system comprising a first component and a second component, each of the first component and the second component being separate and distinct from each other, and wherein the first component comprises a dissolved and / or dispersed carboxylic acid functional polymer, wherein the carboxylic acid functional polymer comprises carboxylic acid groups and / or carboxylate groups, and the second component comprises the polyaziridine compound of any one of claims 1 to 17 or the crosslinker composition of any one of claims 18 to 21.

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