Aqueous epoxy resin composition, process for its preparation and use thereof

Abstract

The application discloses a kind of water-based epoxy resin composition and its preparation method and application, the composition includes following weight ratio of each raw material: water-based epoxy resin 35-80%, preferably 40-80%, more preferably 50-70%, ketone imine end-capped hydrolysable silane 5-20%, preferably 5-15%, more preferably 5-10%, cyclic carbonate 1-20%, preferably 5-20%, more preferably 5-10%, water-based secondary amine curing agent 10-50%, preferably 10-40%, more preferably 20-40%. The composition not only has longer operation time, but also can be dried completely in a very short time after construction, and exhibits better adhesion on metal and concrete surface, and has very good water resistance and salt fog resistance.

Description

Technical Field

[0001] This invention relates to an epoxy resin composition, and more particularly to an aqueous epoxy resin composition, its preparation method, and its application. Background Technology

[0002] Waterborne epoxy coatings are environmentally friendly coatings, and their performance mainly depends on the waterborne curing agent. During the synthesis of waterborne curing agents, to ensure sufficient working time, highly reactive primary amines in the curing agent are often capped to form secondary amine groups. However, with a high proportion of primary amine capping, the post-curing performance of the waterborne curing agent is significantly insufficient, and accelerators cannot be directly added. This results in insufficient crosslinking density, leading to inadequate adhesion, water resistance, and salt spray resistance.

[0003] To address the aforementioned issues, organosilicon compounds are often introduced into waterborne epoxy coating systems as coupling agents. However, directly adding primary amino organosilicon compounds to waterborne coatings can significantly reduce the working time of the coatings.

[0004] Patent DE69915740T2 uses organosilicon compounds with ketimine-terminated ends to prepare curable resin systems, which solves the problem of working time of water-based curing agents. However, this solution cannot solve the problems of post-curing performance of secondary amine groups in water-based curing agents and insufficient toughness of curing agents, which seriously affects the crosslinking density of the system.

[0005] Therefore, while ensuring that the water-based curing agent has a long working time, how to improve the post-curing performance of water-based epoxy coatings, and how to improve their adhesion, water resistance and salt spray resistance, is a technical challenge. Summary of the Invention

[0006] To address the above technical problems, this invention proposes a waterborne epoxy resin composition, its preparation method, and its application. The composition not only has a long working time but also dries completely within a short time after application, exhibits good adhesion to metal and concrete surfaces, and possesses excellent water and salt spray resistance.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0008] A waterborne epoxy resin composition comprising the following raw materials in the indicated weight ratios:

[0009] The waterborne epoxy resin content is 35-80%, preferably 40-80%, and more preferably 50-70%.

[0010] The amount of ketimide-terminated hydrolyzable silane is 5-20%, preferably 5-15%, more preferably 5-10%.

[0011] Cyclic carbonates 1-20%, preferably 5-20%, more preferably 5-10%.

[0012] The water-based secondary amine curing agent comprises 10-50%, preferably 10-40%, and more preferably 20-40%.

[0013] As a preferred embodiment of the present invention, the waterborne epoxy resin is selected from one or more of bisphenol A epoxy resin, bisphenol F epoxy resin, phenolic epoxy resin, glycidyl ether type epoxy resin, and glycidyl amine type epoxy resin.

[0014] Preferably, the waterborne epoxy resin is an epoxy emulsion with a solid content of 40-70% and an epoxy equivalent of 300-1500, preferably at least one of epoxy resin E20 and epoxy resin E51, and more preferably at least one of wantipro0906, wantipro0901, and Nantong Xingchen epoxy emulsion 0912A.

[0015] As a preferred embodiment of the present invention, the ketimine-terminated hydrolyzable silane is a reaction product of a hydrolyzable silane containing a primary amine group and an aldehyde / ketone compound.

[0016] Preferably, the hydrolyzable silane containing a primary amino group is one or more of 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-aminopropylmethyldimethoxysilane, aminopropylmethyldiethoxysilane, N-(β-aminoethyl)-γ-aminopropyltrimeth(eth)oxysilane, N-aminoethyl-3-aminopropylmethyldimethoxysilane, and diethylenetriaminopropyltrimethoxysilane;

[0017] Preferably, the aldehyde / ketone compound is one or more of formaldehyde, paraformaldehyde, benzaldehyde, acetaldehyde, pentanal, octanal, phenylacetaldehyde, glyoxal, malondialdehyde, adipaldehyde, acetone, butanone, acetophenone, methyl isobutyl ketone, and cyclohexanone.

[0018] As a preferred embodiment of the present invention, the cyclic carbonate is one or more of ethylene carbonate, propylene carbonate, butene carbonate, and bicyclic carbonate.

[0019] As a preferred embodiment of the present invention, the aqueous secondary amine curing agent is a capped primary amine curing agent, preferably a polyamine and a substance containing an amino reactive group as the reaction product of the capping agent.

[0020] As a preferred embodiment of the present invention, the polyamine is selected from one or more of aliphatic amines, alicyclic amines, aromatic amines, polyether amines and their modifiers, and the end-capping agent is selected from one or more of substances containing epoxy groups, unsaturated hydrocarbon groups, carboxyl groups, aldehyde groups and ketone groups.

[0021] As a preferred embodiment of the present invention, the fatty amine ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentanediamine, methylpentanediamine, hexanediamine, N-(2-ethylamino)-1,3-propanediamine, and N,N'-di(3-aminopropyl)-1,2-ethylenediamine are selected as one or more of the following:

[0022] Preferably, the alicyclic amine is isophorone diamine, 1,3-cyclohexanedimethylamine, 4,4'-diaminodicyclohexylmethane, 3,3'-dimethyl-4,4'-diaminodicyclohexylmethane, 1-methyl-2,4-cyclohexanediamine, 1,2-diaminocyclohexane, N-cyclohexyl-1,3-propanediamine, cyclohexylamine, N... 1 -(3-aminopropyl)-N 3 One or more of cyclohexyl-1,3-propanediamine;

[0023] Preferably, the aromatic amine is one or more selected from diaminodiphenylmethane, m-phenylenediamine, toluenediamine, and diethyltoluenediamine;

[0024] Preferably, the polyetheramine is one or more of Wanamine 8100, Wanamine 8200, Jeffamine D2000, Jeffamine T403, Jeffamine D220, Jeffamine D400, and Jeffamine T5000;

[0025] Preferably, the modified polyamine can be a modified amine compound obtained through the following chemical modifications: Mannich modification, amidation, epoxy addition, etc.

[0026] Preferably, the capping agent is selected from one or more of epoxy resin, glycidyl ether, glycidyl amine, acrylic resin, acrylate resin, formaldehyde, paraformaldehyde, benzaldehyde, acetaldehyde, pentanal, octanal, phenylacetaldehyde, glyoxal, malondialdehyde, adipaldehyde, acetone, butanone, acetophenone, methyl isobutyl ketone, and cyclohexanone.

[0027] In this invention, the waterborne epoxy resin composition may optionally include one or more of pigments, fillers, dispersants, leveling agents, defoamers, wetting agents, flame retardants, and diluents as additives.

[0028] As pigments and fillers suitable for the present invention, pigments and filler components known in the coating field, such as calcium carbonate, barium sulfate, silica powder, titanium dioxide, carbon black, talc, nano clay, and graphite, can be selected.

[0029] BYK-190, BYK-192, etc. can be selected as dispersants suitable for this invention.

[0030] As a leveling agent suitable for the present invention, BYK-333, TEGO Glide 407, etc. can be selected.

[0031] As a defoamer suitable for the present invention, BYK-012, BYK-028, tego FOAMEX 810, etc. can be selected.

[0032] As a wetting agent suitable for the present invention, tego270, tego4100, etc. can be selected.

[0033] As flame retardants suitable for use in this invention, sodium silicate, DOPO system flame retardants, etc., can be selected.

[0034] As a diluent suitable for the present invention, propylene glycol methyl ether, ethylene glycol butyl ether, etc. can be selected.

[0035] The present invention also provides a method for preparing the waterborne epoxy resin composition as described above, characterized in that, according to the weight ratio, the waterborne epoxy resin, ketimide-terminated hydrolyzable silane, cyclic carbonate, and waterborne secondary amine curing agent are mixed and stirred to obtain the waterborne epoxy resin composition.

[0036] The present invention also provides the application of the waterborne epoxy resin composition as described above in waterborne coatings.

[0037] The beneficial effects of this invention are as follows:

[0038] By end-capping the hydrolyzable silane and releasing primary amine groups through hydrolysis after film formation, not only is there a longer operating time, but the cyclic carbonate can also react rapidly with the primary amine groups during film formation, thereby increasing the drying time and crosslinking density of the coating film in a short time. This solves the problem that existing technologies cannot balance operating time and drying speed.

[0039] The waterborne epoxy resin in this invention has strong post-curing properties and good system compatibility, which can give the paint film good mechanical and thermal properties, as well as good adhesion to metal and concrete surfaces. Detailed Implementation

[0040] The present invention will be further illustrated below with specific embodiments. These embodiments are merely illustrative and do not limit the scope of the invention.

[0041] The names, abbreviations, and sources of the main chemicals used in the embodiments of this invention are shown in the table below. Unless otherwise specified, all reagents used are of analytical grade.

[0042] The main raw material information involved in the following specific implementation methods is shown in Table 1:

[0043] Table 1. Information on Main Raw Materials

[0044] Triethylenetetramine, diethylenetriamine, 593 curing agent, m-phenylenediamine Inokai Butyl glycidyl ether Anhui Xinyuan Epoxy Resin E51 South Asia Resin γ-aminopropyltriethoxysilane Inokai N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane Inokai 3-Aminopropyltrimethoxysilane Inokai Paraformaldehyde, butyraldehyde, butanone, methyl isobutyl ketone Inokai Ethylene carbonate, propylene carbonate, butene carbonate Inokai dimer acid Shandong Huijin Isophorone diamine (IPDA) Wanhua Chemical Hydroxyethyl acrylate Wanhua Chemical Epoxy emulsion wantipro0906 Wanhua Chemical Epoxy Emulsion 0912A Nantong Xingchen

[0045] The main testing methods used in this invention are as follows:

[0046] (1) Operating time: The viscosity of the material at 25°C was recorded using a Bollerfeld viscometer. The operating time of the epoxy resin blend is the time it takes for the viscosity to double.

[0047] (2) Adhesion test of paint film: The adhesion test of metal surface is carried out according to the method in GB / T9286—1998 "Cross-cut test of paint and varnish film". The test level is divided into 0-5 according to the standard record. The smaller the value, the better the adhesion.

[0048] (3) Impact resistance test of paint film: The impact strength of the paint film is represented by the maximum height (cm) from which a heavy hammer falls on the test plate without causing damage to the paint film.

[0049] (4) Hot water resistance test: The paint film prepared by the composition is subjected to a water immersion performance test at 50℃. The test method is Method C in GB / T9274-1988 Determination of resistance to liquid media of paints and varnishes. Observe whether there are blistering, rust or other corrosion phenomena in the paint film.

[0050] (5) Salt spray resistance test: The paint film prepared by the composition is subjected to a neutral salt spray test. The test method is GB / T1771-1991 Determination of neutral salt spray resistance of paints and varnishes.

[0051]

Preparation of Example 1

[0052] 3-Aminopropyltriethoxysilane (1 mol, 221 g) and paraformaldehyde (1 mol, 30 g) were heated to 50 °C with stirring and kept at this temperature for 2 h. After heating, the mixture was dehydrated under vacuum to obtain ketimine-terminated hydrolyzable silane A.

[0053] N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane (1 mol, 222 g) and butyraldehyde (1 mol, 72 g) were heated to 70 °C with stirring and kept at this temperature for 2 h. After being dehydrated under vacuum, ketimine-terminated hydrolyzable silane B was obtained.

[0054] 3-Aminopropyltrimethoxysilane (1 mol, 179 g) and butanone (1 mol, 72 g) were heated to 70 °C with stirring and kept at this temperature for 2 h. After heating, the mixture was dehydrated under vacuum to obtain ketimine-terminated hydrolyzable silane C.

[0055] 3-Aminopropylmethyldimethoxysilane (1 mol, 163 g) and methyl isobutyl ketone (1 mol, 100 g) were heated to 70 °C with stirring and kept at this temperature for 2 h. After heating, the mixture was dehydrated under vacuum to obtain ketimine-terminated hydrolyzable silane D.

[0056]

Preparation of Example 2

[0057] Triethylenetetramine (1 mol, 146 g), epoxy resin E51 (0.25 mol, 95 g), and butyl glycidyl ether (1.5 mol, 201 g) were mixed and heated to 50 °C with stirring. After holding at this temperature for 2 h, deionized water was added to adjust the epoxy equivalent to 270, thus obtaining end-capped primary amine curing agent A.

[0058] Mix 593 curing agent (1 mol, 217 g) and dimer acid (0.5 mol, 280 g), heat to 180 °C with stirring, keep warm for 2 h, then cool to 80 °C, add deionized water and propylene glycol methyl ether diluent to adjust the epoxy equivalent to 270, and obtain end-capped primary amine curing agent B.

[0059] Isophorone diamine (1 mol, 170 g), hydroxyethyl acrylate (1 mol, 116 g), and butyl glycidyl ether (1 mol, 134 g) were mixed and heated to 80 °C with stirring. After holding at this temperature for 2 h, deionized water and propylene glycol methyl ether were added to adjust the epoxy equivalent to 270, thus obtaining end-capped primary amine curing agent C.

[0060] The m-phenylenediamine (1 mol, 136 g), butanone (1 mol, 72 g), and butyl glycidyl ether (1 mol, 134 g) were mixed and heated to 80 °C with stirring. After holding at this temperature for 2 h, deionized water and ethylene glycol butyl ether were added to adjust the epoxy equivalent to 400, thus obtaining the end-capped primary amine curing agent D.

[0061]

Example 1

[0062] 60g of epoxy emulsion wantipro0906, 20g of ketimide-terminated hydrolyzable silane A, 7.5g of ethylene carbonate, and 12.5g of terminated primary amine curing agent A were mixed and stirred until homogeneous to obtain an aqueous epoxy composition.

[0063]

Examples 2-8

[0064] Different waterborne epoxy compositions were prepared using the raw material compositions and formulations shown in Table 2.

[0065] Table 2. Formulations of waterborne epoxy compositions in Examples 1-8

[0066]

[0067] Comparative Example 1

[0068] Aqueous epoxy compositions were prepared under essentially the same conditions as in Example 1, except that ethylene carbonate was not added.

[0069] Comparative Example 2

[0070] Aqueous epoxy compositions were prepared under essentially the same conditions as in Example 1, except that the end-capped primary amine curing agent A was replaced with diethylenetriamine.

[0071] The performance of the waterborne epoxy compositions provided in each embodiment and comparative example was tested, and the results are shown in Table 3:

[0072] Table 3. Performance Test Results

[0073]

[0074]

[0075] The above description is only a preferred embodiment of the present invention. It should be noted that those skilled in the art can make several improvements and additions without departing from the method of the present invention, and these improvements and additions should also be considered within the scope of protection of the present invention.

Claims

1. A waterborne epoxy resin composition, characterized in that, The raw materials include the following ingredients in the indicated weight ratios: Waterborne epoxy resin 35-80%, Ketoimine-terminated hydrolyzable silanes, 5-20%. Cyclic carbonates 1-20%, Water-based secondary amine curing agent 10-50%.

2. The aqueous epoxy resin composition according to claim 1, characterized in that, The raw materials include the following ingredients in the indicated weight ratios: Waterborne epoxy resin 40-80%, Ketoimine-terminated hydrolyzable silanes, 5-15%, Cyclic carbonates 5-20%, Water-based secondary amine curing agent 10-40%.

3. The aqueous epoxy resin composition according to claim 1, characterized in that, The raw materials include the following ingredients in the indicated weight ratios: Waterborne epoxy resin 50-70%, Ketoimine-terminated hydrolyzable silanes, 5-10%, Cyclic carbonates 5-10%, Water-based secondary amine curing agent 20-40%.

4. The aqueous epoxy resin composition according to claim 1, characterized in that, The waterborne epoxy resin is selected from one or more of bisphenol A epoxy resin, bisphenol F epoxy resin, phenolic epoxy resin, glycidyl ether type epoxy resin, and glycidyl amine type epoxy resin.

5. The aqueous epoxy resin composition according to claim 1, characterized in that, The ketimine-terminated hydrolyzable silane is a reaction product of a hydrolyzable silane containing a primary amine group and a ketone compound.

6. The aqueous epoxy resin composition according to claim 5, characterized in that, The hydrolyzable silanes containing primary amino groups are one or more of the following: 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-aminopropylmethyldimethoxysilane, aminopropylmethyldiethoxysilane, N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, N-aminoethyl-3-aminopropylmethyldimethoxysilane, and diethylenetriaminopropyltrimethoxysilane.

7. The aqueous epoxy resin composition according to claim 5, characterized in that, Ketone compounds are one or more of acetone, butanone, acetophenone, methyl isobutyl ketone, and cyclohexanone.

8. The aqueous epoxy resin composition according to any one of claims 1-7, characterized in that, The cyclic carbonate is one or more of ethylene carbonate, propylene carbonate, and butene carbonate.

9. The aqueous epoxy resin composition according to any one of claims 1-7, characterized in that, The cyclic carbonate is a bicyclic carbonate.

10. The aqueous epoxy resin composition according to any one of claims 1-7, characterized in that, The aqueous secondary amine curing agent is a capped primary amine curing agent.

11. The aqueous epoxy resin composition according to claim 10, characterized in that, The aqueous secondary amine curing agent is a reaction product of polyamine and a substance containing amino reactive groups as a capping agent.

12. The aqueous epoxy resin composition according to claim 11, characterized in that, The polyamine is selected from one or more of aliphatic amines, alicyclic amines, aromatic amines, polyether amines and their modifiers, and the end-capping agent is selected from one or more of substances containing epoxy groups, unsaturated hydrocarbon groups, carboxyl groups, aldehyde groups and ketone groups.

13. The aqueous epoxy resin composition according to claim 12, characterized in that, The fatty amine is one or more of the following: ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentamethylenediamine, methylpentanediamine, hexamethylenediamine, N-(2-ethylamino)-1,3-propanediamine, and N,N'-di(3-aminopropyl)-1,2-ethylenediamine.

14. The aqueous epoxy resin composition according to claim 13, characterized in that, The alicyclic amine is isophorone diamine, 1,3-cyclohexanedimethylamine, 4,4'-diaminodicyclohexylmethane, 3,3'-dimethyl-4,4'-diaminodicyclohexylmethane, 1-methyl-2,4-cyclohexanediamine, 1,2-diaminocyclohexane, N-cyclohexyl-1,3-propanediamine, cyclohexylamine, N... 1 -(3-aminopropyl)-N 3 One or more of cyclohexyl-1,3-propanediamine.

15. The aqueous epoxy resin composition according to claim 13, characterized in that, The aromatic amine is one or more of diaminodiphenylmethane, m-phenylenediamine, toluenediamine, and diethyltoluenediamine.

16. The aqueous epoxy resin composition according to claim 13, characterized in that, The polyetheramine is one or more of Wanamine 8100, Wanamine 8200, Jeffamine D2000, Jeffamine T403, Jeffamine D220, Jeffamine D400, and Jeffamine T5000.

17. The aqueous epoxy resin composition according to claim 13, characterized in that, The capping agent is selected from one or more of the following: epoxy resin, glycidyl ether, glycidyl amine, acrylic resins, acrylates, formaldehyde, paraformaldehyde, benzaldehyde, acetaldehyde, pentanal, octanal, phenylacetaldehyde, glyoxal, malondialdehyde, adipaldehyde, acetone, butanone, acetophenone, methyl isobutyl ketone, and cyclohexanone.

18. A method for preparing an aqueous epoxy resin composition according to any one of claims 1-17, characterized in that, The components of waterborne epoxy resin, ketimide-terminated hydrolyzable silane, cyclic carbonate, and waterborne secondary amine curing agent are mixed and stirred according to the weight ratio to obtain a waterborne epoxy resin composition.

19. The use of a waterborne epoxy resin composition as described in any one of claims 1-17 in waterborne coatings.

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