MULTI-AZIRIDINE COMPOUND

Abstract

The present invention relates to a multi-aziridine compound having: a) from 2 to 6 of the following structural units (A): whereby R′, R″ are as defined herein m is an integer from 1 to 6; b) one or more linking chains wherein each one of these linking chains links two of the structural units A; and c) a molecular weight in the range from 840 Daltons to 5000 Daltons. The multi-aziridine compound can be used for example for crosslinking of for example carboxylic acid functional polymers dissolved and/or dispersed in an aqueous medium.

##STR00001##

Claims

1. A multi-aziridine compound having: a) from 2 to 6 of the following structural units (A): ##STR00051## whereby m is an integer from 1 to 6; and R′ and R″ are according to (1) or (2): (1) R′═H or an aliphatic hydrocarbon group containing from 1 to 14 carbon atoms, R″═H, an aliphatic hydrocarbon group containing from 1 to 14 carbon atoms, a cycloaliphatic hydrocarbon group containing from 5 to 12 carbon atoms, an aromatic hydrocarbon group containing from 6 to 12 carbon atoms, CH.sub.2—O—(C═O)—R′″, CH.sub.2—O—R″″, or CH.sub.2—(OCR′″″HCR′″″H).sub.n—OR″″″, whereby R′″ is an aliphatic hydrocarbon group containing from 1 to 14 carbon atoms and R″″ is an aliphatic hydrocarbon group containing from 1 to 14 carbon atoms or an aromatic hydrocarbon group containing from 6 to 12 carbon atoms, n being from 1 to 35, R′″″ independently being H or an aliphatic hydrocarbon group containing from 1 to 14 carbon atoms and R″″″ being an aliphatic hydrocarbon group containing from 1 to 4 carbon atoms, and whereby either R′ or R″ is not H; (2) R′ and R″ form together a saturated cycloaliphatic hydrocarbon group containing from 5 to 8 carbon atoms; b) one or more linking chains wherein each one of these linking chains links two of the structural units A; and c) a molecular weight in the range from 840 Daltons to 5000 Daltons, wherein the molecular weight is determined using MALDI-TOF mass spectrometry according to the description.

2. The multi-aziridine compound according to claim 1, wherein m is 1; R′ and R″ are according to (1) or (2): (1) R′═H or an alkyl group containing from 1 to 2 carbon atoms, and R″═H, an aliphatic hydrocarbon group containing from 1 to 4 carbon atoms, CH.sub.2—O—(C═O)—R′″, CH.sub.2—O—R″″, or CH.sub.2—(OCR′″″HCR′″″H).sub.n—OR″″″, whereby R′″ is an alkyl group containing from 1 to 14 carbon atoms and R″″ is an alkyl group containing from 1 to 14 carbon atoms, n being from 1 to 35, R′″″ independently being H or a methyl group and R″″″ being an alkyl group containing from 1 to 4 carbon atoms, and whereby either R′ or R″ is not H; (1) R′ and R″ form part of a saturated cycloaliphatic hydrocarbon group containing from 5 to 8 carbon atoms.

3. The multi-aziridine compound according to claim 1, wherein R′═H, and R″=an aliphatic hydrocarbon group containing from 1 to 14 carbon atoms, a cycloaliphatic hydrocarbon group containing from 5 to 12 carbon atoms, an aromatic hydrocarbon group containing from 6 to 12 carbon atoms, CH.sub.2—O—(C═O)—R′″, CH.sub.2—O—R″″, or CH.sub.2—(OCR′″″HCR″″″H).sub.n—OR″″″, whereby R′″ is an aliphatic hydrocarbon group containing from 1 to 14 carbon atoms and R″″ is an aliphatic hydrocarbon group containing from 1 to 14 carbon atoms or an aromatic hydrocarbon group containing from 6 to 12 carbon atoms, n being from 1 to 35, R′″″ independently being H or an aliphatic hydrocarbon group containing from 1 to 14 carbon atoms and R″″″ being an aliphatic hydrocarbon group containing from 1 to 4 carbon atoms.

4. The multi-aziridine compound according to claim 1, wherein R′ is H and R″=an alkyl group containing from 1 to 4 carbon atoms, CH.sub.2—O—(C═O)—R′″, CH.sub.2—O—R″″, or CH.sub.2—(OCH.sub.2CH.sub.2).sub.n—OCH.sub.3, whereby R′″ is an alkyl group containing from 3 to 12 carbon atoms and R″″ is an alkyl group containing from 1 to 14 carbon atoms.

5. The multi-aziridine compound according to claim 1, wherein the multi-aziridine compound contains 2 or 3 structural units (A).

6. The multi-aziridine compound according to claim 1, wherein the linking chains consist of from 4 to 300 atoms, more preferably from 5 to 250 and most preferably from 6 to 100 atoms and the linking chains are a collection of atoms covalently connected which collection of atoms consists of i) carbon atoms, ii) carbon and nitrogen atoms, or iii) carbon, oxygen and nitrogen atoms.

7. The multi-aziridine compound according to claim 1, wherein the multi-aziridine compound has a molecular weight of from 840 to 3800 Daltons, whereby the molecular weight is determined using MALDI-TOF mass spectrometry according to the description.

8. The multi-aziridine compound according to claim 1, wherein the multi-aziridine compound comprises one or more connecting groups wherein each one of these connecting groups connects two of the structural units A, whereby the connecting groups consist of at least one functionality selected from: aliphatic hydrocarbon functionality, cycloaliphatic hydrocarbon functionality, aromatic hydrocarbon functionality, isocyanurate functionality, iminooxadiazindione functionality, ether functionality, ester functionality, amide functionality, carbonate functionality, urethane functionality, urea functionality, biuret functionality, allophanate functionality, uretdione functionality and any combination thereof.

9. The multi-aziridine compound according to claim 8, wherein the connecting groups of the multi-aziridine compound consist of at least one functionality selected from: aliphatic hydrocarbon functionality, cycloaliphatic hydrocarbon functionality, aromatic hydrocarbon functionality, isocyanurate functionality, iminooxadiazindione functionality, urethane functionality, urea functionality, biuret functionality and any combination thereof.

10. The multi-aziridine compound according to claim 1, wherein the multi-aziridine compound comprises one or more connecting groups wherein each one of these connecting groups connects two of the structural units A, wherein the connecting groups consist of (i) at least two aliphatic hydrocarbon functionality or at least two cycloaliphatic hydrocarbon functionality and (ii) an isocyanurate functionality or an iminooxadiazindione functionality, and wherein a pendant group is present on a connecting group, whereby the pendant group has the following structural formula: ##STR00052## n′ is the number of repeating units and is an integer from 1 to 50, preferably from 2 to 30, more preferably from 5 to 20. X is O or NH, R.sub.7 and R.sub.8 are independently H or CH.sub.3 in each repeating unit, R.sub.9 is an aliphatic hydrocarbon group, preferably containing from 1 to 8 carbon atoms, or a cycloaliphatic hydrocarbon group, preferably containing from 4 to 10 carbon atoms, and R.sub.10 contains at most 20 carbon atoms and is an aliphatic, cycloaliphatic or aromatic hydrocarbon group or a combination thereof.

11. The multi-aziridine compound according to claim 10, wherein X is O and R.sub.7 and R.sub.8 are H.

12. The multi-aziridine compound according to claim 10, wherein the multi-aziridine compound contains 2 structural units (A).

13. The multi-aziridine compound according to claim 12, wherein the connecting group consists of the array of the following consecutive functionalities: a first aliphatic hydrocarbon functionality, an isocyanurate functionality or an iminooxadiazindione functionality, and a second aliphatic hydrocarbon functionality, and R.sub.9 is an aliphatic hydrocarbon group, whereby the first and second aliphatic hydrocarbon functionality and R.sub.9 are identical.

14. The multi-aziridine compound according to claim 1, wherein the multi-aziridine compound contains polyoxyethylene (—O—CH2-CH2-).sub.x group(s) in an amount of at least 0.1 wt. %, preferably at least 6 wt. %, more preferably at least 10 wt. % and in an amount of less than 45 wt. %, more preferably less than 25 wt. % and most preferably less than 16 wt. %, relative to the multi-aziridine compound.

15. The multi-aziridine compound, wherein the multi-aziridine compound is obtained by reacting at least a polyisocyanate and a compound B with the following structural formula: ##STR00053## whereby the molar ratio of compound B to polyisocyanate is from 2 to 6, preferably from 2.1 to 5 and most preferably from 2.4 to 3., and whereby m, R′, and R″, are defined as in claim 1.

16. The multi-aziridine compound according to claim 15, wherein the polyisocyanate is a polyisocyanate with aliphatic reactivity.

17. The multi-aziridine compound according to claim 15, wherein compound B is obtained by reacting at least a non-OH functional monoepoxide compound with ethyleneimine.

18. The multi-aziridine compound according to claim 17, wherein the non-OH functional monoepoxide compound is selected from the group consisting of n-butylglycidylether, 2-ethylhexylglycidylether, glycidyl neodecanoate, and any mixture thereof.

19. A crosslinker composition comprising at least one multi-aziridine compound according to claim 1 and further comprising at least one additional component.

20. The crosslinker composition according to claim 19, wherein the molecular weight of the multi-aziridine compounds present in the crosslinker composition is in the range from 840 Daltons to 5000 Daltons, whereby the molecular weight is determined using MALDI-TOF mass spectrometry according to the description.

21. The crosslinker composition according to claim 19, wherein the amount of aziridine functional molecules having a molecular weight lower than 820 Daltons is lower than 1.5 wt. %, preferably lower than 1 wt. %, relative to the total weight of the crosslinker composition, whereby the molecular weight is determined using LC-MS as described in the description.

22. The crosslinker composition according to claim 19, wherein the crosslinker composition contains less than 5 wt. % of water.

23. Use of the multi-aziridine compound according to claim 1 or the crosslinker composition for crosslinking a carboxylic acid functional polymer dissolved and/or dispersed in an aqueous medium, whereby the carboxylic acid functional polymer contains carboxylic acid groups and/or carboxylate groups.

24. A two-component coating system comprising a first component and a second component each of which is separate and distinct from each other and wherein the first component comprises a carboxylic acid functional polymer dissolved and/or dispersed, preferably dispersed, in an aqueous medium, whereby the carboxylic acid functional polymer contains carboxylic acid groups and/or carboxylate groups and the second component comprises a multi-aziridine compound according to claim 1 or the second component is a crosslinker composition.

Description

COMPARATIVE EXAMPLE 1

[0120] Comparative Example 1 is CX-100, trimethylolpropane tris(2-methyl-1-aziridinepropionate), obtained from DSM. Chemical structure is shown below.

##STR00026##

[0121] For reference, the performance of trimethylolpropane tris(2-methyl-1-aziridinepropionate) as a crosslinker was assessed using spot tests on coating surfaces, based on procedures 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™ DMM (dipropylene glycol dimethyl ether, mixture of isomers) and incubated at 80° C. for 10 minutes under regular agitation. 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. Afterwards, this coating composition was filtered and applied to Leneta test cards using 100 μm wire rod applicators (Test C1-1). The films were dried for 16 hours at 25° C., then annealed at 50° C. for 1 hour and further dried for 24 hours at 25° C. Subsequently, a piece of cotton wool was soaked in 1:1 EtOH demineralized water and placed on the film for various timespans. After removal of the EtOH and 60 minutes recovery, the following results were obtained (a score of 1 indicates complete degradation of the film, 10 indicates no damage visible):

[0122] Ethanol Spot Test

TABLE-US-00001 Sample 30 min 60 min 120 min 300 min Test C1-1 8 7 7 6

[0123] Genotoxicity Test

TABLE-US-00002 Without S9 rat liver extract With S9 rat liver extract concentration Bscl 2 Rtkn Bscl 2 Rtkn .fwdarw. 10 25 50 10 25 50 10 25 50 10 25 50 Comp. Ex. 1 1.2 1.5 2.0 1.4 2.0 3.2 1.7 2.3 2.1 3.0 4.3 3.4

[0124] The genotoxicity test results show that the crosslinker of Comparative Example 1 is genotoxic.

COMPARATIVE EXAMPLE 2

[0125] 15.0 grams of Desmodur N 3600 and 75 grams of dimethylformamide were charged to a reaction flask equipped with a thermometer. The mixture was stirred with a mechanical upper stirrer under a nitrogen atmosphere. The mixture was than heated to 50° C., whereafter 6.80 grams of 1-(2-hydroxyethyl)ethyleneimine was added. 15 minutes later 0.03 grams of bismuth neodecanoate was charged to the reaction flask, which was then heated further to 60° C. Samples were taken at regular intervals and the reaction progress was monitored using a Bruker Alpha FT-IR spectrometer until no NCO-stretch at 2200-2300 cm.sup.−1 was observed. The solvent was removed in vacuo to obtain a clear, slightly yellowish highly viscous liquid. The calculated molecular weight of the theoretical main component was 765.47 Da, chemical structure is shown below.

##STR00027##

[0126] Molecular weight was confirmed by Maldi-TOF-MS: Calcd. [M+K+]=804.43 Da; Obs. [M+K+]=804.27 Da.

[0127] Genotoxicity Test

TABLE-US-00003 Without S9 rat liver extract With S9 rat liver extract concentration Bscl 2 Rtkn Bscl 2 Rtkn .fwdarw. 10 25 50 10 25 50 10 25 50 10 25 50 Comp. Ex. 2 1.1 1.3 1.4 1.7 2.4 2.8 1.4 1.9 1.9 2.0 3.4 3.0

[0128] The genotoxicity test results show that the crosslinker of Comparative Example 2 is genotoxic.

COMPARATIVE EXAMPLE 3

[0129] 2.60 grams of 1-(aziridin-1-yl)propan-2-ol, 0.02 grams of bismuth neodecanoate and 32 grams of dimethylformamide were charged to a reaction flask equipped with a thermometer. The mixture was stirred with a mechanical upper stirrer under a nitrogen atmosphere and heated to 50° C. A solution of 5.00 grams of Desmodur N 3600 in 32 grams of dimethylformamide was then added dropwise in 15 minutes to the reaction flask, where after the mixture was heated further to 70° C. Samples were taken at regular intervals and the reaction progress was monitored using a Bruker Alpha FT-IR spectrometer until no NCO-stretch at 2200-2300 cm.sup.−1 was observed. The solvent was removed in vacuo to obtain an opaque highly viscous liquid. The calculated molecular weight of the theoretical main component was 807.52 Da, chemical structure is shown below.

##STR00028##

[0130] Molecular weight was confirmed by Maldi-TOF-MS: Calcd. [M+Na+]=830.52 Da; Obs. [M+Na+]=830.47 Da.

[0131] Genotoxicity Test

TABLE-US-00004 Without S9 rat liver extract With S9 rat liver extract concentration Bscl 2 Rtkn Bscl 2 Rtkn .fwdarw. 10 25 50 10 25 50 10 25 50 10 25 50 Comp. Ex. 3 1.1 1.3 1.3 1.3 1.8 1.9 1.3 1.8 1.8 1.3 2.1 2.2

[0132] The genotoxicity test results show that the crosslinker of Comparative Example 3 is genotoxic.

EXAMPLE 1

[0133] A round bottom flask equipped with a condensor was placed under a N.sub.2 atmosphere and charged with ethylene imine (50.0 gram), n-butyl glycidyl ether (108.0 gram) and K.sub.2CO.sub.3 (5.00 gram) and heated to 40° C. in 30 min, after which the mixture was stirred for 48 h at T=40° C. After filtration the excess of El was removed in vacuo, followed by further purification via vacuum distillation, resulting in a colorless low viscous liquid. 3.45 grams of the resulting material (1-(aziridin-1-yl)-3-butoxypropan-2-ol) was charged to a reaction flask equipped with a thermometer, together with 0.02 grams of bismuth neodecanoate and 15 grams of dimethylformamide. The mixture was stirred with a mechanical upper stirrer under a nitrogen atmosphere and heated to 50° C. A solution of 4.00 grams of Desmodur® N 3600 in 8 grams of dimethylformamide was then added dropwise in 45 minutes to the reaction flask, while keeping the reaction temperature constant at 50° C. Samples were taken at regular intervals and the reaction progress was monitored using a Bruker Alpha FT-IR spectrometer until no change in NCO-stretch at 2200-2300 cm.sup.−1 was observed. Subsequently, 0.13 grams of 1-butanol were added to the mixture, followed by further reaction to complete disappearance of aforementioned NCO-stretch peak. Concentration of the solution in vacuo to a 25 wt % solution yielded a slightly viscous liquid.

[0134] The calculated theoretical molecular weight of the main component was 1023.69 Da, chemical structure is shown below.

##STR00029##

[0135] Molecular weight was confirmed by Maldi-TOF-MS: Calcd. [M+Na+]=1046.69 Da; Obs. [M+Na+]=1046.72 Da.

[0136] The following components with a mass below 840 Da were determined by LC-MS and quantified:

##STR00030##

[0137] was present in the composition at 0.48 wt. % and

##STR00031##

[0138] was present at less than 0.01 wt. %.

[0139] Performance of the synthesized compound as a crosslinker was assessed using spot tests on coating surfaces, based on procedures from DIN 68861-1:2011-01 standard. For these tests, 1.4 parts of the crosslinker solution were added to 10 parts of P1 under continuous stirring, and the resulting mixture was further stirred for 30 minutes. Afterwards, this coating composition was filtered and applied to Leneta test cards using 100 μm wire rod applicators (Test 1-1). For reference, films were also cast from the same composition lacking a crosslinker (Test 1-2). The films were dried for 16 hours at 25° C., then annealed at 50° C. for 1 hour and further dried for 24 hours at 25° C. Subsequently, a piece of cotton wool was soaked in 1:1 EtOH: demineralized water and placed on the film for various timespans. After removal of the EtOH and 60 minutes recovery, the following results were obtained (a score of 1 indicates complete degradation of the film, 5 indicates no damage visible):

[0140] Ethanol Spot Test

TABLE-US-00005 Sample 60 min 240 min Test 1-1 5 4 Test 1-2 1 1

[0141] Genotoxicity Test

TABLE-US-00006 Without S9 rat liver extract With S9 rat liver extract concentration Bscl 2 Rtkn Bscl 2 Rtkn .fwdarw. 10 25 50 10 25 50 10 25 50 10 25 50 Ex. 1 1.1 1.1 1.0 1.0 1.0 0.9 1.1 1.1 1.2 1.0 1.1 1.1

[0142] The genotoxicity test results show that the crosslinker composition of Example 1 is non-genotoxic.

COMPARATIVE EXAMPLE 4

[0143] 1.00 grams of 4,4′-methylenebis(cyclohexyl isocyanate) and 4.8 grams of dimethylformamide were charged to a reaction flask equipped with a thermometer. The mixture was stirred with a mechanical upper stirrer under a nitrogen atmosphere and heated to 50° C. 0.02 grams of bismuth neodecanoate was added to the solution. A solution of 1.21 grams 1-(aziridin-1-yl)-3-butoxypropan-2-ol in 2.28 grams of dimethylformamide was then added dropwise in 15 minutes to the reaction flask, where after the mixture was heated further to 80° C. Samples were taken at regular intervals and the reaction progress was monitored using a Bruker Alpha FT-IR spectrometer until no change in NCO-stretch at 2200-2300 cm.sup.−1 was observed. Subsequently, 0.05 grams of 1-butanol were added to the mixture, followed by further reaction to complete disappearance of aforementioned NCO-stretch peak. Evaporation of the solvent in vacuo yielded a highly viscous opaque liquid. The calculated theoretical molecular weight of the main component was 608.45 Da, chemical structure is shown below.

##STR00032##

[0144] Molecular weight was confirmed by Maldi-TOF-MS: Calcd. [M+Na+]=631.45 Da; Obs. [M+Na+]=631.45 Da.

[0145] Genotoxicity Test

TABLE-US-00007 Without S9 rat liver extract With S9 rat liver extract concentration Bscl 2 Rtkn Bscl 2 Rtkn .fwdarw. 10 25 50 10 25 50 10 25 50 10 25 50 Comp. Ex 4 1.1 1.4 1.6 1.2 1.5 2.1 1.2 1.5 1.4 1.1 1.6 1.9

[0146] The genotoxicity test results show that the crosslinker composition of Comp Ex 4 is genotoxic.

EXAMPLE 2

[0147] A round bottom flask equipped with a condensor was placed under a N.sub.2 atmosphere and charged with ethylene imine (50.0 gram), n-butyl glycidyl ether (108.0 gram) and K.sub.2CO.sub.3 (5.00 gram) and heated to 40° C. in 30 min, after which the mixture was stirred for 48 h at T=40° C. After filtration the excess of El was removed in vacuo, followed by further purification via vacuum distillation, resulting in a colorless low viscous liquid.

[0148] 0.67 grams of the resulting material (1-(aziridin-1-yl)-3-butoxypropan-2-ol) was charged to a feeding funnel together with 0.54 grams of a poly(ethylene glycol) monomethyl ether with an average Mn of 500 Da and 2.28 grams of dimethylformamide. This mixture was fed in 15 minutes to a reaction flask equipped with a thermometer and filled with 1.00 grams of Desmodur® N 3600, 4.54 grams of DMF and 0.02 grams of bismuth neodecanoate at 50° C., while the mixture was stirred with a mechanical upper stirrer under a nitrogen atmosphere. After the feed was completed, the mixture was heated further to 80° C. Samples were taken at regular intervals and the reaction progress was monitored using a Bruker Alpha FT-IR spectrometer until no change in NCO-stretch at 2200-2300 cm.sup.−1 was observed. Subsequently, 0.03 grams of 1-butanol were added to the mixture, followed by further reaction to complete disappearance of aforementioned NCO-stretch peak. Concentration of the solution in vacuo to a 25 wt % solution yielded a slightly viscous liquid.

[0149] The calculated molecular weights of the theoretical main components were 1023.69 Da (three aziridines), 1322.84 Da (two aziridines, 10 EG repeating units) and 1366.87 Da (two aziridines, 11 EG repeating units).

##STR00033##

[0150] Molecular weight was confirmed by Maldi-TOF-MS: Calcd. [M+Na+]=1046.69 Da; Obs. [M+Na+]=1046.16 Da.

##STR00034##

[0151] Molecular weight was confirmed by Maldi-TOF-MS: Calcd. [M+Na+]=1345.84 Da; Obs. [M+Na+]=1345.31 Da.

##STR00035##

[0152] Molecular weight was confirmed by Maldi-TOF-MS: Calcd. [M+Na+]=1389.87 Da; Obs. [M+Na+]=1389.52 Da.

[0153] The following components with a mass below 820 Da were determined by LC-MS and quantified:

##STR00036##

[0154] was present in the composition at less than 0.01 wt % and

##STR00037##

[0155] was present at less than 0.01 wt. %.

[0156] Performance of the synthesized compound as a crosslinker was assessed using spot tests on coating surfaces, based on procedures from the DIN 68861-1:2011-01 standard. For these tests, 2.4 parts of the crosslinker solution were added to 10 parts of P1 under continuous stirring, and the resulting mixture was further stirred for 30 minutes. Afterwards, this coating composition was filtered and applied to Leneta test cards using 100 μm wire rod applicators (Test 2-1). For reference, films were also cast from the same composition lacking a crosslinker (Test 2-2). The films were dried for 16 hours at 25° C., then annealed at 50° C. for 1 hour and further dried for 24 hours at 25° C. Subsequently, a piece of cotton wool was soaked in 1:1 EtOH: demineralized water and placed on the film for various timespans. After removal of the EtOH and 60 minutes recovery, the following results were obtained (a score of 1 indicates complete degradation of the film, 5 indicates no damage visible):

[0157] Ethanol Spot Test

TABLE-US-00008 Sample 30 min 240 min Test 2-1 3 3 Test 2-2 1 1

[0158] Genotoxicity Test

TABLE-US-00009 Without S9 rat liver extract With S9 rat liver extract concentration Bscl 2 Rtkn Bscl 2 Rtkn .fwdarw. 10 25 50 10 25 50 10 25 50 10 25 50 Ex. 2 1.1 1.2 1.2 1.2 1.3 1.2 1.1 1.1 1.1 1.1 1.2 1.1

[0159] The genotoxicity test results show that the crosslinker composition of Example 2 is non-genotoxic.

EXAMPLE 3

[0160] A round bottom flask equipped with a condensor was placed under a N.sub.2 atmosphere and charged with ethylene imine (40.0 gram), Cardura E10P (151.5 gram) and K.sub.2CO.sub.3 (4.00 gram) and heated to 40° C., after which the mixture was stirred for 48 h at T=40° C. After filtration the excess of El was removed in vacuo, followed by further purification via vacuum distillation, resulting in a colorless low viscous liquid.

[0161] 1.35 grams of the resulting material (3-(aziridin-1-yl)-2-hydroxypropyl neodecanoate) was charged to a feeding funnel together with 2.40 grams of dimethylformamide. This mixture was fed in 15 minutes to a reaction flask equipped with a thermometer and filled with 1.00 grams of Desmodur® N 3600, 4.80 grams of DMF and 0.02 grams of bismuth neodecanoate at 50° C., while the mixture was stirred with a mechanical upper stirrer under a nitrogen atmosphere. After the feed was completed, the mixture was heated further to 80° C. Samples were taken at regular intervals and the reaction progress was monitored using a Bruker Alpha FT-IR spectrometer until no change in NCO-stretch at 2200-2300 cm.sup.−1 was observed. Subsequently, 0.03 grams of 1-butanol were added to the mixture, followed by further reaction to complete disappearance of the aforementioned NCO-stretch peak. Concentration of the solution in vacuo to a 25 wt % solution yielded a slightly viscous liquid.

[0162] The calculated molecular weight of the theoretical main component was 1317.91 Da, chemical structure is shown below.

##STR00038##

[0163] Molecular weight was confirmed by Maldi-TOF-MS: Calcd. [M+Na+]=1340.91 Da; Obs. [M+Na+]=1340.88 Da.

[0164] The following components with a mass below 820 Da were determined by LC-MS and quantified:

##STR00039##

[0165] was present in the composition at less than 0.01 wt % and

##STR00040##

[0166] was present at 0.07 wt. %.

[0167] Performance of the synthesized compound as a crosslinker was assessed using spot tests on coating surfaces, based on procedures from the DIN 68861-1:2011-01 standard. For these tests, 2.0 parts of the crosslinker solution were added to 10 parts of P1 under continuous stirring, and the resulting mixture was further stirred for 30 minutes. Afterwards, this coating composition was filtered and applied to Leneta test cards using 100 μm wire rod applicators (Test 3-1). For reference, films were also cast from the same composition lacking a crosslinker (Test 3-2). The films were dried for 16 hours at 25° C., then annealed at 50° C. for 1 hour and further dried for 24 hours at 25° C. Subsequently, a piece of cotton wool was soaked in 1:1 EtOH: demineralized water and placed on the film for various timespans. After removal of the EtOH and 60 minutes recovery, the following results were obtained (a score of 1 indicates complete degradation of the film, 5 indicates no damage visible):

[0168] Ethanol Spot Test

TABLE-US-00010 Sample 30 min 240 min Test 3-1 4 4 Test 3-2 1 1

[0169] Genotoxicity Test

TABLE-US-00011 Without S9 rat liver extract With S9 rat liver extract concentration Bscl 2 Rtkn Bscl 2 Rtkn .fwdarw. 10 25 50 10 25 50 10 25 50 10 25 50 Ex. 3 1.1 1.2 1.4 1.3 1.5 1.5 1.1 1.2 1.2 1.3 1.5 1.5

[0170] The genotoxicity test results show that the crosslinker composition of Example 3 is non-genotoxic.

EXAMPLE 4

[0171] A round bottom flask equipped with a condensor was placed under a N.sub.2 atmosphere and charged with ethylene imine (50.0 gram), n-butyl glycidyl ether (108.0 gram) and K.sub.2CO.sub.3 (5.00 gram) and heated to 40° C. in 30 min, after which the mixture was stirred for 48 h at T=40° C. After filtration the excess of El was removed in vacuo, followed by further purification via vacuum distillation, resulting in a colorless low viscous liquid. 3.37 grams of the resulting material (1-(aziridin-1-yl)-3-butoxypropan-2-ol) was charged to a feeding funnel together with 5.4 grams Jeffamine® XTJ-436 (CAS number 118270-87-4, obtained from Huntsman) and 30 grams of dimethylformamide. This mixture was fed in 15 minutes to a reaction flask equipped with a thermometer and filled with 5.00 grams of Desmodur® N 3600, 40 grams of DMF and 0.12 grams of bismuth neodecanoate at 50° C., while the mixture was stirred with a mechanical upper stirrer under a nitrogen atmosphere. After the feed was completed, the mixture was heated further to 80° C. Samples were taken at regular intervals and the reaction progress was monitored using a Bruker Alpha FT-IR spectrometer until no change in NCO-stretch at 2200-2300 cm.sup.−1 was observed. Subsequently, 0.16 grams of 1-butanol were added to the mixture, followed by further reaction to complete disappearance of aforementioned NCO-stretch peak. Concentration of the solution in vacuo to a 25 wt % solution yielded a slightly viscous liquid.

[0172] The calculated molecular weights of the theoretical main components were 1023.69 Da (three aziridines), 1824.30 Da (two aziridines, 13 PO repeating units) and 1882.34 Da (two aziridines, 14 PO repeating units).

##STR00041##

[0173] Molecular weight was confirmed by Maldi-TOF-MS: Calcd. [M+Na+]=1046.69 Da; Obs. [M+Na+]=1046.71 Da.

##STR00042##

[0174] Molecular weight was confirmed by Maldi-TOF-MS: Calcd. [M+Na+]=1847.29 Da; Obs. [M+Na+]=1847.40 Da.

##STR00043##

[0175] Molecular weight was confirmed by Maldi-TOF-MS: Calcd. [M+Na+]=1905.33 Da; Obs. [M+Na+]=1905.44 Da.

[0176] The following components with a mass below 820 Da were determined by LC-MS and quantified:

##STR00044##

[0177] was present in the composition at less than 0.01 wt % and

##STR00045##

[0178] was present at less than 0.01 wt. %.

[0179] Performance of the synthesized compound as a crosslinker was assessed using spot tests on coating surfaces, based on procedures from the DIN 68861-1:2011-01 standard. For these tests, 1.0 parts of the crosslinker solution were added to 15 parts of P1 under continuous stirring, and the resulting mixture was further stirred for 30 minutes. Afterwards, this coating composition was filtered and applied to Leneta test cards using 100 μm wire rod applicators (Test 4-1). For reference, films were also cast from the same composition lacking a crosslinker (Test 4-2). The films were dried for 16 hours at 25° C., then annealed at 50° C. for 1 hour and further dried for 24 hours at 25° C. Subsequently, a piece of cotton wool was soaked in 1:1 EtOH: demineralized water and placed on the film for various timespans. After removal of the EtOH and 60 minutes recovery, the following results were obtained (a score of 1 indicates complete degradation of the film, 5 indicates no damage visible):

[0180] Ethanol Spot Test

TABLE-US-00012 Sample 60 min 240 min Test 4-1 3 3 Test 4-2 1 1

[0181] A waterborne acrylic binder was synthesized as follows.

[0182] A 2 L four-necked flask equipped with a thermometer and overhead stirrer was charged with sodium lauryl sulphate (30% solids in water, 18.6 grams of solution) and demineralized water (711 grams). The reactor phase was placed under N.sub.2 atmosphere and heated to 82° C. A mixture of demineralized water (112 grams), sodium lauryl sulphate (30% solids in water, 37.2 grams of solution), methyl methacrylate (174.41 grams), n-butyl acrylate (488.44 grams) and methacrylic acid (34.88 grams) was placed in a large feeding funnel and emulsified with an overhead stirrer (monomer feed). Ammonium persulphate (1.75 grams) was dissolved in demineralized water (89.61 grams) and placed in a small feeding funnel (initiator feed). Ammonium persulphate (1.75 grams) was dissolved in demineralized water (10.5 grams), and this solution was added to the reactor phase. Immediately afterwards, 5% by volume of the monomer feed was added to the reactor phase. The reaction mixture then exothermed to 85° C. and was kept at 85° C. for 5 minutes. Then, the residual monomer feed and the initiator feed were fed to the reaction mixture over 90 minutes, maintaining a temperature of 85° C. After completion of the feeds, the monomer feed funnel was rinsed with demineralized water (18.9 grams) and reaction temperature maintained at 85° C. for 45 minutes. Subsequently, the mixture was cooled to room temperature and brought to pH=7.2 with ammonia solution (6.25 wt. % in demineralized water), and brought to 40% solids with further demineralized water.

[0183] For further spot tests, performance of the synthesized compound as a crosslinker was assessed using spot tests on coating surfaces, based on procedures from the DIN 68861-1:2011-01 standard. For these tests, 1.1 parts of the crosslinker solution were added to 15 parts of the acrylic binder described above under continuous stirring, and the resulting mixture was further stirred for 30 minutes. Afterwards, this coating composition was filtered and applied to Leneta test cards using 100 μm wire rod applicators (Test 4-3). For reference, films were also cast from the same composition lacking a crosslinker (Test 4-4). The films were dried for 16 hours at 25° C., then annealed at 50° C. for 1 hour and further dried fo 24 hours at 25° C. Subsequently, a piece of cotton wool was soaked in 1:1 EtOH: demineralized water and placed on the film for various timespans. After removal of the EtOH and 60 minutes recovery, the following results were obtained (a score of 1 indicates complete degradation of the film, 5 indicates no damage visible):

[0184] Ethanol Spot Test

TABLE-US-00013 Sample 60 min 240 min Test 4-3 3 3 Test 4-4 1 1

[0185] Genotoxicity Test

TABLE-US-00014 Without S9 rat liver extract With S9 rat liver extract concentration Bscl 2 Rtkn Bscl 2 Rtkn .fwdarw. 10 25 50 10 25 50 10 25 50 10 25 50 Ex. 4 1.0 1.0 1.1 1.0 1.1 1.1 1.0 1.0 1.0 1.0 1.0 1.0

[0186] The genotoxicity test results show that the crosslinker composition of Example 4 is non-genotoxic.

EXAMPLE 5

[0187] A round bottom flask equipped with a condensor was placed under a N.sub.2 atmosphere and charged with ethylene imine (50.0 gram), n-butyl glycidyl ether (108.0 gram) and K.sub.2CO.sub.3 (5.00 gram) and heated to 40° C. in 30 min, after which the mixture was stirred for 48 h at T=40° C. After filtration the excess of El was removed in vacuo, followed by further purification via vacuum distillation, resulting in a colorless low viscous liquid. 5.61 grams of the resulting material (1-(aziridin-1-yl)-3-butoxypropan-2-ol) was charged to a reaction flask equipped with a thermometer, together with 0.02 grams of bismuth neodecanoate and 32 grams of dimethylformamide. The mixture was stirred with a mechanical upper stirrer under a nitrogen atmosphere and heated to 50° C. A solution of 6.30 grams of Desmodur® N 3900 in 34 grams of dimethylformamide was then added dropwise in 15 minutes to the reaction flask, while keeping the reaction temperature constant at 50° C. Samples were taken at regular intervals and the reaction progress was monitored using a Bruker Alpha FT-IR spectrometer until no change in NCO-stretch at 2200-2300 cm.sup.−1 was observed. Subsequently, 0.21 grams of 1-butanol were added to the mixture, followed by further reaction to complete disappearance of aforementioned NCO-stretch peak. Concentration of the solution in vacuo to a 25 wt % solution yielded a slightly viscous liquid.

[0188] The calculated theoretical molecular weight of the main component was 1023.69 Da, chemical structure is shown below.

##STR00046##

[0189] Molecular weight was confirmed by Maldi-TOF-MS: Calcd. [M+Na+]=1046.69 Da; Obs. [M+Na+]=1046.73 Da.

[0190] The following components with a mass below 820 Da were determined by LC-MS and quantified:

##STR00047##

was present in the composition at 0.07 wt % and

##STR00048##

[0191] was present at less than 0.01 wt. % and

##STR00049##

[0192] was present at less than 0.01 wt. %.

[0193] Performance of the synthesized compound as a crosslinker was assessed using spot tests on coating surfaces, based on procedures from DIN 68861-1:2011-01 standard. For these tests, 1.4 parts of the crosslinker solution were added to 10 parts of P1 under continuous stirring, and the resulting mixture was further stirred for 30 minutes. Afterwards, this coating composition was filtered and applied to Leneta test cards using 100 μm wire rod applicators (Test 5-1). For reference, films were also cast from the same composition lacking a crosslinker (Test 5-2). The films were dried for 16 hours at 25° C., then annealed at 50° C. for 1 hour and further dried fo 24 hours at 25° C. Subsequently, a piece of cotton wool was soaked in 1:1 EtOH: demineralized water and placed on the film for various timespans. After removal of the EtOH and 60 minutes recovery, the following results were obtained (a score of 1 indicates complete degradation of the film, 5 indicates no damage visible): Ethanol spot test

TABLE-US-00015 Sample 60 min 240 min Test 5-1 5 4 Test 5-2 1 1

[0194] Genotoxicity Test

TABLE-US-00016 Without S9 rat liver extract With S9 rat liver extract concentration Bscl 2 Rtkn Bscl 2 Rtkn .fwdarw. 10 25 50 10 25 50 10 25 50 10 25 50 Ex. 5 1.1 1.1 0.9 1.0 1.1 1.0 1.1 1.1 1.2 1.0 0.9 1.0

[0195] The genotoxicity test results show that the crosslinker composition of example 5 is non-genotoxic.

COMPARATIVE EXAMPLE 5

[0196] Comparative Example 5 is pentaerythritol tris(3-(1-aziridinyl)propionate), CAS number 57116-45-7, obtained from ABCR. Chemical structure is shown below.

##STR00050##

[0197] Genotoxicity Test

TABLE-US-00017 Without S9 rat liver extract With S9 rat liver extract concentration Bscl 2 Rtkn Bscl 2 Rtkn .fwdarw. 10 25 50 10 25 50 10 25 50 10 25 50 Ex. 5 1.2 1.4 2.1 1.2 1.7 3.5 1.1 1.5 2.3 1.3 2.1 4.3

[0198] The genotoxicity test results show that the crosslinker of Comp Ex 5 is genotoxic.