Aspartic polyurea coating adhesion promoter, and preparation method and application thereof

Abstract

The application relates to the technical field of polyaspartic ester, and specifically discloses an aspartic polyurea coating adhesion promoter, a preparation method and application thereof. The preparation method of the adhesion promoter is as follows: an amine compound, a ketone compound and / or an aldehyde compound are subjected to dehydration condensation, and then modified by a silane coupling agent, so that the aspartic polyurea coating adhesion promoter is prepared. The adhesion promoter has the following advantages when applied to the aspartic polyurea coating: the adhesion promoter participates in the curing of the aspartic polyurea coating, can effectively reduce the failure of the adhesion of the aspartic polyurea coating, the adhesion promoter slowly releases reaction groups -NH2, -NH and / or -OH after absorbing water vapor in the air through the aspartic polyurea coating, participates in cross-linking and curing, and the reaction speed is slow; the adhesion promoter contains multiple reactive groups, the range of the addition amount of the adhesion promoter can be adjusted, and the adhesion promoter has a smaller influence on the film performance.

Description

Technical Field

[0001] This application relates to the technical field of polyaspartic esters, and more specifically, to an aspartic polyurea coating adhesion promoter, its preparation method, and its application. Background Technology

[0002] Aspartic polyurea coatings are made by mixing and reacting multiple components, including polyaspartic esters and isocyanates. Compared with other materials, aspartic polyurea coatings have better weather resistance, aging resistance, UV resistance, impact resistance, waterproofing, corrosion resistance, and low-temperature resistance. They can be directly exposed outdoors for many years without aging or chalking, and can remain as good as new after washing. However, aspartic polyurea coatings have relatively poor adhesion to substrates.

[0003] In related technologies, adhesion promoters such as silane coupling agents are commonly used to improve the adhesion of aspartic polyurea coatings to the substrate. Commonly used silane coupling agents include aminosiloxanes (KH550), epoxysiloxanes (KH560), acryloyloxysiloxanes (KH570), and vinylsiloxanes. Among these, aminosiloxanes contain primary amine groups and react extremely quickly in aspartic polyurea coatings, significantly impacting the coating's pot life (i.e., the allowable storage time after mixing). Epoxysiloxanes, acryloyloxysiloxanes, and vinylsiloxanes, however, cannot participate in cross-linking with polyaspartic esters to form a film, easily leading to adhesion failure.

[0004] Therefore, there is a need to provide an adhesion promoter suitable for aspartic polyurea coatings in order to further broaden the application range of aspartic polyurea coatings. Summary of the Invention

[0005] This application provides an aspartic polyurea coating adhesion promoter, its preparation method, and its application. The adhesion promoter of this application has the following advantages when used in aspartic polyurea coatings: the silane hydrolysis in the adhesion promoter can form chemical bonds with the substrate surface, thereby improving the adhesion between the aspartic polyurea coating and the substrate; the adhesion promoter participates in the curing of the aspartic polyurea coating, effectively reducing the failure of the aspartic polyurea coating adhesion; the adhesion promoter slowly releases reactive groups -NH2, -NH, and / or -OH after absorbing moisture from the air through the aspartic polyurea coating, participating in cross-linking curing, with a slow reaction rate; the adhesion promoter contains multiple reactive groups, allowing for a wide range of adjustment in the amount added, and has minimal impact on the coating film performance.

[0006] In a first aspect, this application provides a method for preparing an aspartic polyurea coating adhesion promoter, which adopts the following technical solution:

[0007] A preparation method of an aspartic polyurea coating adhesion promoter, the preparation method comprising: dehydrating and condensing an amine compound, a ketone compound and / or an aldehyde compound, and then modifying the dehydrated and condensed product with a silane coupling agent, thereby obtaining the aspartic polyurea coating adhesion promoter.

[0008] Optionally, the amine compound is one or a combination of aromatic amine, alicyclic amine, aliphatic amine or phenolic amine; and contains at least two functional groups, which are one or a combination of -NH2, -NH and -OH.

[0009] Optionally, the amine compound is selected from isophorone diamine, 3,3'-dimethyl-4,4-diaminodicyclohexyl methane, 4,4'-diaminodicyclohexyl methane, 1-methyl-2,4-cyclohexanediamine, pentanediamine, 2-methyl-1,5-pentanediamine, polyether amine D230, polyether amine D2000, polyether amine T403, m-xylylenediamine, cyclohexanedimethylamine, cyclohexanediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, aminoethylpiperazine, ethanolamine, diethanolamine, mono-isopropanolamine, di-isopropanolamine, 2-amino-2-methyl-1-propanol, N-(2-hydroxyethyl)ethylenediamine.

[0010] Optionally, the amine compound is an amino alcohol.

[0011] Optionally, the amino alcohol is at least one of ethanolamine, diethanolamine, mono-isopropanolamine, di-isopropanolamine, 2-amino-2-methyl-1-propanol, N-(2-hydroxyethyl)ethylenediamine or a modified amino alcohol obtained by ring opening of an epoxy compound with -NH2.

[0012] Optionally, the ketone compound is at least one of acetone, butanone, methyl isobutyl ketone, methyl isoamyl ketone, methyl isopropyl ketone and phenylacetone.

[0013] The aldehyde compound is at least one of benzaldehyde, phenylacetaldehyde, n-butyraldehyde, isobutyraldehyde, isoamyl aldehyde, 2,2-dimethyl-3-lauryloxy-propanal.

[0014] Optionally, the silane coupling agent is at least one of alkylsilane, vinylsilane, acryloxy silane, epoxy silane, isocyanate silane.

[0015] Optionally, the silane coupling agent is at least one selected from the group consisting of tetramethoxysilane, tetraethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, styrene ethyl trimethoxysilane, (3-acryloyloxypropyl) trimethoxysilane, (3-methacryloyloxypropyl) trimethoxysilane, (3-acryloyloxypropyl) triethoxysilane, (3-methacryloyloxypropyl) triethoxysilane, 3-(2,3-epoxypropoxy) propyl trimethoxysilane, 2-(3,4-epoxycyclohexyl) ethyl trimethoxysilane, 3-isocyanate propyl trimethoxysilane, 3-isocyanate propyl triethoxysilane.

[0016] Optionally, the preparation method is: dropping the ketone compound and / or the aldehyde compound into the amine compound or the amino alcohol, adding a solvent to reflux and dehydrate, after the dehydration is completed, removing the solvent and unreacted ketone compound and / or aldehyde compound to obtain a modified ketimine, aldimine or oxazolidine; dropping the silane coupling agent into the modified ketimine, aldimine or oxazolidine to react for 2-48h to obtain the adhesion promoter.

[0017] In the second aspect, the application provides an asparto-polyurea coating adhesion promoter prepared by the above preparation method.

[0018] In the third aspect, the application provides an application of the asparto-polyurea coating adhesion promoter in improving the adhesion of asparto-polyurea coating on different substrates.

[0019] In the fourth aspect, the application provides an asparto-polyurea coating, wherein the asparto-polyurea coating comprises the above asparto-polyurea coating adhesion promoter.

[0020] In summary, the application has the following advantages:

[0021] The adhesion promoter of the application has the following advantages when applied in asparto-polyurea coating:

[0022] The silane hydrolysis in the adhesion promoter can form a chemical bond with the surface of the substrate, so that the adhesion between the asparto-polyurea coating and the substrate is more excellent;

[0023] The adhesion promoter participates in the curing of the asparto-polyurea coating, which can effectively reduce the failure of the adhesion of the asparto-polyurea coating;

[0024] The adhesion promoter slowly releases the reactive groups -NH2, -NH and / or -OH after absorbing the water vapor in the air through the asparto-polyurea coating, and participates in cross-linking and curing, and the reaction speed is slow;

[0025] The adhesion promoter contains multiple reactive groups, and the addition amount of the adhesion promoter has a large adjustment range and has less influence on the performance of the paint film. DETAILED DESCRIPTION

[0026] Before describing the embodiments of the present application in detail, it should be understood that the terminology used herein is for the purpose of describing specific embodiments only. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this term belongs.

[0027] The present application provides an aspartic polyurea coating adhesion promoter and a preparation method thereof.

[0028] The preparation method of the adhesion promoter is as follows: the ketone compound and / or the aldehyde compound are added dropwise into the amine compound or the amino alcohol, a solvent is added for reflux dehydration, after the dehydration is completed, the solvent and the unreacted ketone compound and / or the aldehyde compound are removed to obtain a ketimine, aldimine or oxazolidine to be modified; the silane coupling agent is added dropwise into the ketimine, aldimine or oxazolidine to be modified and reacted for 2-48 h to obtain the adhesion promoter.

[0029] The present application also provides an application of the aspartic polyurea coating adhesion promoter in improving the adhesion of the aspartic polyurea coating on different substrates.

[0030] The adhesion promoter of the present application is prepared by dehydration condensation of primary amine or amino alcohol with aldehyde and ketone to obtain corresponding ketimine, aldimine or oxazolidine, and then addition reaction of the reaction groups -NH2, -NH or -OH in the ketimine, aldimine or oxazolidine with other groups containing C=C, epoxy group or -NCO.

[0031] The adhesion promoter of the present application and the silane coupling agent promote the adhesion between the coating and the substrate in the same mechanism. The present application mainly provides a modified silane coupling agent participating in the crosslinking and curing of the aspartic polyurea coating. Since the modified silane coupling agent can participate in the crosslinking, the influence on the performance of the coating is smaller when the amount of the modified silane coupling agent is larger; and the participation in the crosslinking and curing can avoid the peeling of the coating from other silane coupling agents, and effectively reduce the adhesion failure.

[0032] In order to make the purpose, technical solutions and advantages of the present application more clear, the technical solutions in the embodiments of the present application are described clearly and completely. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0033] The present application is further described in detail below in combination with the embodiments, comparative examples and performance test results.

[0034] Embodiments

[0035] Embodiment 1

[0036] The embodiment provides an aspartic polyurea coating adhesion promoter.

[0037] A 1L four-necked glass flask is taken, diethylenetriamine 103g (1mol) is added, methyl isobutyl ketone 300g (3mol) is added dropwise, after dehydration at 120 DEG C under reflux, vacuum distillation is carried out, the excessive methyl isobutyl ketone is extracted, and the modified ketimine is obtained.

[0038] Vinyl triethoxysilane 190g (1mol) is added into the modified ketimine, and the temperature is raised to 120 DEG C under nitrogen protection for 48h, so that the adhesion promoter is obtained.

[0039] The adhesion promoter comprises the following structural formula:

[0040]

[0041] Embodiment 2

[0042] The embodiment provides an aspartic polyurea coating adhesion promoter.

[0043] A 1L four-necked glass flask is taken, diethylenetriamine 103g (1mol) is added, methyl isobutyl ketone 300g (3mol) is added dropwise, after dehydration at 120 DEG C under reflux, vacuum distillation is carried out, the excessive methyl isobutyl ketone is extracted, and the modified ketimine is obtained.

[0044] 3-Isocyanate propyl triethoxysilane 247g (1mol) is added dropwise into the modified ketimine, and the temperature is raised to 50 DEG C under nitrogen protection for 6h, so that the adhesion promoter is obtained.

[0045] The adhesion promoter comprises the following structural formula:

[0046]

[0047] Embodiment 3

[0048] The embodiment provides an aspartic polyurea coating adhesion promoter.

[0049] A 1L four-necked glass flask is taken, diethylenetriamine 103g (1mol) is added, methyl isobutyl ketone 300g (3mol) is added dropwise, after dehydration at 120 DEG C under reflux, vacuum distillation is carried out, the excessive methyl isobutyl ketone is extracted, and the modified ketimine is obtained.

[0050] 3-(2,3-epoxypropoxy) propyl trimethoxysilane 236g (1mol) is added into the modified ketimine, and the temperature is raised to 120 DEG C under nitrogen protection for 24h, so that the adhesion promoter is obtained.

[0051] The adhesion promoter described above comprises a compound of the following structural formula:

[0052]

[0053] Example 4

[0054] The present example provides an adhesion promoter for asparto-polyurea coating.

[0055] Take a 2L four-necked glass flask, add tetraethylenepentamine 189g (1mol), drop in benzaldehyde 212g (2mol), after the drop is completed, continue to add 100g cyclohexane, after the temperature is raised to 100°C and reflux dehydration is completed, reduce pressure distillation, extract the excess benzaldehyde and cyclohexane, and obtain the modified aldimine;

[0056] Add (3-methacryloyloxypropyl)trimethoxysilane 744g (3mol) to the modified aldimine described above, and react under nitrogen protection at 80°C for 48h to obtain the adhesion promoter.

[0057] The adhesion promoter described above comprises a compound of the following structural formula:

[0058]

[0059] Example 5

[0060] The present example provides an adhesion promoter for asparto-polyurea coating.

[0061] Take a 1L four-necked glass flask, add diethanolamine 105g (1mol), drop in butanone 144g (2mol), raise the temperature to 90°C and reflux until dehydration is completed, then reduce pressure distillation, extract the excess butanone, and obtain the modified oxazolidine.

[0062] Add 3-(2,3-epoxypropoxy)propyltrimethoxysilane 236g (1mol) to the modified oxazolidine described above, and react under nitrogen protection at 120°C for 24h to obtain the adhesion promoter.

[0063] The adhesion promoter described above comprises a compound of the following structural formula:

[0064]

[0065] Performance test experiment

[0066] The adhesion promoter prepared in the above example was used to prepare asparto-polyurea coating, and the pot life of the asparto-polyurea coating mixed with HDI trimer was detected according to GB / T31416-2015; and the asparto-polyurea coatings prepared in the test group and the control group were respectively coated on different substrates to form asparto-polyurea coating layers, and the surface dry time, pressure dry time, pencil hardness of the asparto-polyurea coating layers on the sandblasted steel plate substrate, and the pull-off adhesion between the asparto-polyurea coating layers coated on different substrates and the substrates were detected.

[0067] Among them, the detection method of surface dry time and pressure dry time refers to GB / T1728-1989, the detection method of pencil hardness refers to GB / T6739-2006, and the detection method of pull-off adhesion refers to ASTM D4541.

[0068] The coating method of asparto-polyurea coating is as follows: a hand spray gun is used to apply the coating, and the average thickness of one application is 70 μm, and then the coating is cured under standard curing conditions for 7 days.

[0069] The components and their amounts in the asparto-polyurea coating are shown in Table 1, the detection results of pot life, surface dry time, pressure dry time, and pencil hardness are shown in Table 2, and the detection results of pull-off adhesion are shown in Table 3.

[0070] Table 1 Components and their amounts in asparto-polyurea coating

[0071]

[0072]

[0073] Table 2 Detection results of pot life, surface dry time, pressure dry time, and pencil hardness

[0074]

[0075] Table 3 Detection results of pull-off adhesion of asparto-polyurea coating layer

[0076]

[0077] In summary, compared with the control group, the use of the adhesion promoter of the present application can effectively improve the adhesion of the asparto-polyurea coating, and in addition, by adjusting the amount of adhesion promoter added in the asparto-polyurea coating, the hardness of the asparto-polyurea coating can also be improved.

[0078] Finally, it should be noted that the above examples are only used to illustrate the technical solutions of the present application, and are not intended to limit the same; although the present application has been described in detail with reference to the foregoing examples, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing examples, or make equivalent replacements for some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for preparing an aspartic polyurea coating adhesion promoter, characterized in that, The preparation method is as follows: an amine compound, ketone compound, and / or aldehyde compound are subjected to dehydration condensation to obtain the corresponding ketimine, aldolimine, or oxazolidine. Then, the reactive groups -NH2, -NH, or -OH in the ketimine, aldolimine, or oxazolidine undergo an addition reaction with the C=C, epoxy group, or -NCO in the silane coupling agent, thereby obtaining an aspartic polyurea coating adhesion promoter. The amine compound is one or a combination of aromatic amines, alicyclic amines, fatty amines, or phenolic amines; and contains at least two functional groups, wherein the functional groups are one or a combination of -NH2, -NH, and -OH, and at least one functional group is -NH2 or -NH.

2. The preparation method according to claim 1, characterized in that, The amine compound is selected from isophorone diamine, 3,3'-dimethyl-4,4-diaminodicyclohexylmethane, 4,4'-diaminodicyclohexylmethane, 1-methyl-2,4-cyclohexanediamine, pentaethylenediamine, 2-methyl-1,5-pentanediamine, polyetheramine D230, polyetheramine D2000, polyetheramine T403, m-phenylenediamine, cyclohexanedimethylamine, cyclohexanediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, aminoethylpiperazine, monoethanolamine, diethanolamine, monoisopropanolamine, diisopropanolamine, 2-amino-2-methyl-1-propanol, and N-(2-hydroxyethyl)ethylenediamine.

3. The preparation method according to claim 1, characterized in that, The amine compound is an amino alcohol; the amino alcohol is at least one of monoethanolamine, diethanolamine, monoisopropanolamine, diisopropanolamine, 2-amino-2-methyl-1-propanol, N-(2-hydroxyethyl)ethylenediamine, or a modified amino alcohol obtained by ring-opening an epoxide compound with -NH2.

4. The preparation method according to claim 1, characterized in that, The ketone compound is selected from at least one of acetone, butanone, methyl isobutyl ketone, methyl isopentyl ketone, methyl isopropyl ketone, and acetophenone.

5. The preparation method according to claim 1, characterized in that, The aldehyde compound is selected from at least one of benzaldehyde, phenylacetaldehyde, n-butyraldehyde, isobutyraldehyde, isovaleraldehyde, and 2,2-dimethyl-3-lauroyloxy-propanal.

6. The preparation method according to claim 1, characterized in that, The silane coupling agent is selected from at least one of vinylsilane, acryloyloxysilane, epoxysilane, and isocyanate-based silane.

7. The preparation method according to claim 1, characterized in that, The silane coupling agent is selected from at least one of vinyltrimethoxysilane, vinyltriethoxysilane, styrene ethyltrimethoxysilane, (3-acryloyloxypropyl)trimethoxysilane, (3-methacryloyloxypropyl)trimethoxysilane, (3-acryloyloxypropyl)triethoxysilane, (3-methacryloyloxypropyl)triethoxysilane, 3-(2,3-epoxypropoxy)propyltrimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-propylisocyanatetrimethoxysilane, and 3-propylisocyanatetriethoxysilane.

8. The preparation method according to claim 1, characterized in that, The ketone compound and / or the aldehyde compound are added dropwise to the amine compound, and a solvent is added for reflux dehydration. After dehydration, the solvent and unreacted ketone compound and / or aldehyde compound are removed to obtain the ketimine, aldolimine or oxazolidine to be modified. The silane coupling agent is added dropwise to the ketimine, aldolimine or oxazolidine to be modified and reacted for 2-48 hours to obtain the adhesion promoter.

9. An aspartic polyurea coating adhesion promoter prepared by any one of claims 1-8.

10. The application of the aspartic polyurea coating adhesion promoter of claim 9 in improving the adhesion of aspartic polyurea coatings on different substrates.

11. An aspartic polyurea coating, characterized in that, The aspartic polyurea coating includes the aspartic polyurea coating adhesion promoter as described in claim 9.

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