Demulsification type water-borne epoxy resin curing agent, preparation method thereof and water-borne coating

Abstract

The invention discloses a demulsification type water-borne epoxy resin curing agent, a preparation method thereof and a water-borne coating, belongs to the technical field of water-borne epoxy resin curing agents, and overcomes the defect that a paint film prepared from an epoxy emulsion coating in the prior art is relatively slow in drying speed. According to the preparation method of the demulsification type water-borne epoxy resin curing agent, the raw materials comprise the following components: component (a) hydrophobic amine and derivatives thereof; the component (b) is a compound containing an epoxy group; the component (c) is a polyether compound containing an epoxy group; the ratio of the molar weight of the component (a) to the molar weight of the epoxy group of the component (b) is 1: (0.01-0.1), and the molar ratio of the component (a) to the component (c) is 1: (3-15). According to the demulsification type water-borne epoxy resin curing agent disclosed by the invention, the coating has very good quick-drying property.

Description

Technical Field

[0001] The invention belongs to the technical field of waterborne epoxy resin curing agents, and in particular relates to a demulsified waterborne epoxy resin curing agent and a preparation method thereof, and a waterborne coating. Background Art

[0002] In recent years, as people's environmental awareness has increased, epoxy resin coatings have shown a trend of changing from "oil" to "water", and the application of water-based epoxy resin coatings has become more and more extensive, and there are more and more types. Epoxy emulsion, also known as epoxy dispersion, has the characteristics of high strength, moisture resistance, oil resistance, and corrosion resistance. It can be used as a raw material for construction materials such as coatings, flooring, and tile adhesives.

[0003] At present, most amine curing agents used in water-based epoxy resin coatings have good hydrophilicity and water retention capacity. After the epoxy emulsion is mixed with the curing agent, the water evaporates slowly due to the strong water retention capacity of the amine, which slows down the demulsification rate of the rubber particles. In turn, the curing speed of the resin in the rubber particles slows down after contact with the amine, resulting in a slower drying speed of the paint film made of water-based epoxy resin. Summary of the invention

[0004] Therefore, the technical problem to be solved by the present invention is to overcome the defect of slow drying speed of the paint film prepared by epoxy emulsion coating in the prior art, thereby providing a demulsified water-based epoxy resin curing agent and a preparation method thereof, and a water-based coating.

[0005] To this end, the present invention provides the following technical solutions.

[0006] In a first aspect, the present invention provides a method for preparing a demulsified waterborne epoxy resin curing agent, wherein the raw materials are composed of the following components:

[0007] Component (a) hydrophobic amines and their derivatives;

[0008] Component (b) a compound containing an epoxy group;

[0009] Component (c) a polyether compound containing an epoxy group;

[0010] The molar ratio of component (a) to the molar ratio of epoxy groups in component (b) is 1:(0.01-0.1), and the molar ratio of component (a) to component (c) is 1:(3-15).

[0011] In an optional embodiment, the ratio of the molar amount of component (a) to the molar amount of epoxy groups of component (b) is 1:(0.02-0.05);

[0012] and / or

[0013] The molar ratio of component (a) to component (c) is 1:(3-10).

[0014] In an optional embodiment, the component (a) is selected from at least one of 4,4'-diaminodicyclohexylmethane and its derivatives, dimethyldiaminocyclohexylmethane and its derivatives;

[0015] The derivative of 4,4'-diaminodicyclohexylmethane may be a tricyclic derivative or a modified derivative thereof;

[0016] The derivative of dimethyldiaminocyclohexylmethane may be a tricyclic derivative or a modified derivative thereof.

[0017] In an optional embodiment, the component (b) is selected from one or more of epoxy resin E51, epoxy resin E20, epoxy resin E54, phenyl glycidyl ether, benzyl glycidyl ether, C12-C14 glycidyl ether, butyl glycidyl ether, 1,4-butanediol diglycidyl ether and 1,2-ethylene glycol diglycidyl ether;

[0018] In an optional embodiment, the component (c) is selected from at least one of polyethylene glycol diglycidyl ether and polypropylene glycol diglycidyl ether.

[0019] In an optional embodiment, the preparation method comprises the following steps:

[0020] A. Add component (a) into a reaction vessel, heat and stir;

[0021] B. adding component (b) into the reaction vessel of step A, reacting to obtain an intermediate product;

[0022] C. adding component (c) into the reaction vessel of step B, reacting to obtain a reaction product;

[0023] D. Cooling the reaction product and adding deionized water to obtain a demulsified waterborne epoxy resin curing agent.

[0024] In an optional embodiment, in step A, heating is performed to 70-100°C, preferably 80-90°C.

[0025] In an optional embodiment, in step B, the reaction conditions are heating and stirring;

[0026] Optionally, the heating temperature is 70 to 100° C., preferably 80 to 90° C.;

[0027] Optionally, the reaction time is 0.5 to 3 hours, preferably 1 to 2 hours.

[0028] In an optional embodiment, in step C, the reaction conditions are heating and stirring;

[0029] Optionally, the heating temperature is 70 to 100° C., preferably 80 to 90° C.;

[0030] Optionally, the reaction time is 0.5 to 3 hours, preferably 1 to 2 hours.

[0031] In an optional embodiment, in step D, after cooling the reaction product to 50-70° C., deionized water at 50-70° C. is added to obtain a demulsified waterborne epoxy resin curing agent;

[0032] Optionally, after adding deionized water, a demulsified water-based epoxy resin curing agent with a mass solid content of 50% to 90% is obtained, and optionally 60% to 80%.

[0033] Optionally, adding deionized water and stirring;

[0034] Optionally, the stirring rate is 1000-3000 rpm.

[0035] In a second aspect, the present invention provides a demulsified waterborne epoxy resin curing agent prepared according to the above preparation method, with an HLB value of 6 to 7.

[0036] In a third aspect, the present invention provides a water-based coating, comprising the demulsified water-based epoxy resin curing agent.

[0037] The present invention can select HMDA or HMDA derivatives, and can prepare demulsified waterborne epoxy resin curing agents with different chain lengths, systems, mechanical strengths and properties by combining compounds with different epoxy groups, so as to meet various application requirements.

[0038] The demulsified water-based epoxy resin curing agent of the present invention can be used alone or in combination with other epoxy resin curing agents, and has a wide range of applications.

[0039] The technical solution of the present invention has the following advantages:

[0040] 1. The raw materials of the demulsified waterborne epoxy resin curing agent of the present invention are composed of the following components: component (a) hydrophobic amines and derivatives thereof; component (b) compounds containing epoxy groups; component (c) polyether compounds containing epoxy groups; the ratio of the molar amount of component (a) to component (b) to the molar amount of epoxy groups of component (b) is 1:(0.01-0.1), and the molar ratio of component (a) to component (c) is 1:(3-15).

[0041] In order to achieve a "quick-drying" effect for the paint film, the present application proposes a method for preparing a demulsified water-based curing agent. The obtained curing agent has low water retention and can demulsify the epoxy emulsion. The emulsion particles rupture to release the reactants, which react with the curing agent quickly to accelerate the reaction rate.

[0042] HLB value (Hydrophile-Lipophile Balance Number), also known as hydrophilic-hydrophobic balance value or water-oil ratio, is used to measure the hydrophilicity and lipophilicity of surfactants. HLB value is generally between 1 and 40. The larger the HLB value, the more hydrophilic the surfactant is, and the smaller the HLB value, the more lipophilic the surfactant is. When the HLB value of a surfactant is between 6 and 7, it has a demulsifying effect and can quickly break the emulsion particles.

[0043] The component (a) of the present invention adopts a hydrophobic amine, and the component (c) polyether compound is introduced to improve its hydrophilicity, and by controlling the raw material ratio, the HLB value of the obtained curing agent is between 6 and 7, the demulsification speed is fast, and the epoxy emulsion after demulsification can fully contact and react with the amine, which can significantly improve the reaction rate and has a very obvious effect on improving the drying speed of the coating; at the same time, the epoxy emulsion after demulsification fully contacts and reacts with the amine, which helps to deepen the degree of reaction and enhance the mechanical properties of the water-based paint film. If the amount of hydrophilic polyether compound added is too much, the system is too hydrophilic, and the obtained curing agent cannot have a demulsification effect. On the contrary, if the hydrophilic polyether compound is added too little, it is too lipophilic, and the epoxy emulsion cannot maintain a homogeneous structure during the operation period after mixing with the curing agent, which may cause it to be impossible to use for construction.

[0044] The demulsified water-based epoxy resin curing agent of the present invention enables the coating to have excellent quick-drying properties, can be applied to the fields of water-based floor and water-based steel structure anticorrosive coatings, and has obvious application value.

[0045] At present, there is no relevant patent or literature recording the preparation method of demulsified water-based curing agent. Therefore, the research and application of demulsified water-based epoxy resin curing agent in the present invention is of great significance. DETAILED DESCRIPTION

[0046] The following examples are provided for a better understanding of the present invention, but are not intended to limit the best mode of implementation, nor to limit the content and protection scope of the present invention. Any product identical or similar to the present invention obtained by anyone under the inspiration of the present invention or by combining the features of the present invention with other prior arts shall fall within the protection scope of the present invention.

[0047] If no specific experimental steps or conditions are specified in the examples, the conventional experimental steps or conditions described in the literature in the field can be used. If no manufacturer is specified for the reagents or instruments used, they are all conventional reagent products that can be obtained commercially.

[0048] The names, abbreviations and sources of the main chemicals used in the examples of the present invention are shown in the following table. Unless otherwise specified, all reagents used were of chemical analytical grade.

[0049] Table 1

[0050]

[0051]

[0052] Example 1

[0053] This embodiment provides a method for preparing a demulsified waterborne epoxy resin curing agent, the specific steps are:

[0054] (1) Add 210 g (1 mol) of HMDA into a three-necked flask and stir at 90°C.

[0055] (2) Add 9.5 g of epoxy resin E51 (0.05 mol of epoxy group) into the three-necked flask of step (1), and stir the reaction at 90° C. for 2 h to obtain an intermediate product.

[0056] (3) Add 519 g (3 mol) of polyethylene glycol diglycidyl ether into the three-necked flask in step (2), and stir the reaction at 90° C. for 2 h to obtain a curing agent product.

[0057] (4) The curing agent product was cooled to 50° C., and 50° C. deionized water was added to obtain a slurry with a mass solid content of 70%. The slurry was stirred and dispersed uniformly at 1200 rpm to obtain a demulsified water-based epoxy resin curing agent.

[0058] Example 2

[0059] This embodiment provides a method for preparing a demulsified waterborne epoxy resin curing agent, the specific steps are:

[0060] (1) Add 210 g (1 mol) of HMDA into a three-necked flask and stir at 90°C.

[0061] (2) Add 9.5 g of epoxy resin E51 (0.05 mol of epoxy group) into the three-necked flask of step (1), and stir the reaction at 90° C. for 2 h to obtain an intermediate product.

[0062] (3) Add 553.6 g (3.2 mol) of polyethylene glycol diglycidyl ether into the three-necked flask of step (2), and stir the reaction at 90° C. for 2 h to obtain a curing agent product.

[0063] (4) The curing agent product was cooled to 50° C., and 50° C. deionized water was added to obtain a slurry with a mass solid content of 70%. The slurry was stirred and dispersed uniformly at 1200 rpm to obtain a demulsified water-based epoxy resin curing agent.

[0064] Example 3

[0065] This embodiment provides a method for preparing a demulsified waterborne epoxy resin curing agent, the specific steps are:

[0066] (1) Add 210 g (1 mol) of HMDA into a three-necked flask and stir at 90°C.

[0067] (2) Add 4.75 g of epoxy resin E51 (0.025 mol of epoxy group) into the three-necked flask of step (1), and stir the reaction at 90° C. for 2 h to obtain an intermediate product.

[0068] (3) Add 519 g (3 mol) of polyethylene glycol diglycidyl ether into the three-necked flask in step (2), and stir the reaction at 90° C. for 2 h to obtain a curing agent product.

[0069] (4) The curing agent product was cooled to 50° C., and 50° C. deionized water was added to obtain a slurry with a mass solid content of 70%. The slurry was stirred and dispersed uniformly at 1200 rpm to obtain a demulsified water-based epoxy resin curing agent.

[0070] Example 4

[0071] This embodiment provides a method for preparing a demulsified waterborne epoxy resin curing agent, the specific steps are:

[0072] (1) Add 210 g (1 mol) of HMDA into a three-necked flask and stir at 90°C.

[0073] (2) Add 9.5 g of epoxy resin E51 (0.05 mol of epoxy group) into the three-necked flask of step (1), and stir the reaction at 90° C. for 2 h to obtain an intermediate product.

[0074] (3) Add 865 g (5 mol) of polyethylene glycol diglycidyl ether into the three-necked flask in step (2), and stir the mixture at 90° C. for 2 h to obtain a curing agent product.

[0075] (4) The curing agent product was cooled to 50° C., and 50° C. deionized water was added to obtain a slurry with a mass solid content of 70%. The slurry was stirred and dispersed uniformly at 1200 rpm to obtain a demulsified water-based epoxy resin curing agent.

[0076] Example 5

[0077] (1) Add 210 g (1 mol) of HMDA into a three-necked flask and stir at 90°C.

[0078] (2) Add 3.8 g (0.02 mol of epoxy group) of epoxy resin E51 into the three-necked flask of step (1), and stir the reaction at 90° C. for 2 h to obtain an intermediate product.

[0079] (3) Add 1384 g (8 mol) of polyethylene glycol diglycidyl ether into the three-necked flask in step (2), and stir the mixture at 90° C. for 2 h to obtain a curing agent product.

[0080] (4) The curing agent product was cooled to 50° C., and 50° C. deionized water was added to obtain a slurry with a mass solid content of 70%. The slurry was stirred and dispersed uniformly at 1200 rpm to obtain a demulsified water-based epoxy resin curing agent.

[0081] Example 6

[0082] (1) Add 210 g (1 mol) of HMDA into a three-necked flask and stir at 90°C.

[0083] (2) Add 3.8 g of epoxy resin E51 (0.02 mol of epoxy group) into the three-necked flask of step (1), and stir the reaction at 90° C. for 2 h to obtain an intermediate product.

[0084] (3) Add 1730 g (10 mol) of polyethylene glycol diglycidyl ether into the three-necked flask in step (2), and stir the mixture at 90° C. for 2 h to obtain a curing agent product.

[0085] (4) The curing agent product was cooled to 50° C., and 50° C. deionized water was added to obtain a slurry with a mass solid content of 70%. The slurry was stirred and dispersed uniformly at 1200 rpm to obtain a demulsified water-based epoxy resin curing agent.

[0086] Comparative Example 1

[0087] This comparative example provides a method for preparing a water-based epoxy resin curing agent, comprising the following steps:

[0088] (1) Add 210 g (1 mol) of HMDA into a three-necked flask and stir at 90°C.

[0089] (2) Add 3.8 g of epoxy resin E51 (0.02 mol of epoxy group) into the three-necked flask of step (1), and stir the reaction at 90° C. for 2 h to obtain an intermediate product.

[0090] (3) Add 3287 g (19 mol) of polyethylene glycol diglycidyl ether into the three-necked flask in step (2), and stir the reaction at 90° C. for 2 h to obtain a curing agent product.

[0091] (4) The curing agent product was cooled to 50° C., and 50° C. deionized water was added to obtain a slurry with a mass solid content of 70%. The slurry was stirred and dispersed uniformly at 1200 rpm to obtain a demulsified water-based epoxy resin curing agent.

[0092] Table 2

[0093]

[0094] Test example

[0095] The HLB values ​​of the waterborne epoxy resin curing agents prepared in each embodiment and comparative example were calculated respectively, and the calculation formula is as follows:

[0096] HLB=HLB (a) ×q (a) +HLB (b) ×q (b) +HLB (c) ×q (c)

[0097] Among them, HLB (a) is the HLB value of component (a), HLB (b) is the HLB value of component (b), HLB (c) is the HLB value of component (c);

[0098] Based on the total mass of component (a) + component (b) + component (c), q (a) is the mass percentage of component (a), q (b) is the mass percentage of component (b), q (c) is the mass percentage of component (c);

[0099] HLB value of HMDA (a) =3.048, HLB value of E51 (b) =3.432, HLB value of polyethylene glycol glycidyl ether (c) =7.269.

[0100] The water-based epoxy resin curing agent prepared in each embodiment and comparative example was mixed evenly with the epoxy resin emulsion wanpro0906 in a mass ratio of 1:2, and then the paint film sample was scraped and the paint film drying test was carried out. The test method was based on "GB / 1728-89 Paint Film and Putty Film Drying Time Determination Method". The specific test results are shown in Table 3.

[0101] Table 3

[0102]

[0103]

[0104] It can be seen from the test results in Table 2 that the epoxy resin cured paint film prepared by the demulsified water-based epoxy resin curing agent of Examples 1 to 6 of the present invention has a fast drying speed, can meet the application requirements of epoxy resin floor materials, and has good application prospects.

[0105] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived from these are still within the scope of protection of the invention.

Claims

1. A method for preparing a demulsified waterborne epoxy resin curing agent, characterized in that: The raw materials consist of the following components: Component (a) hydrophobic amines and their derivatives; Component (b) a compound containing an epoxy group; Component (c) a polyether compound containing an epoxy group; The molar ratio of component (a) to the molar ratio of epoxy groups in component (b) is 1:(0.01-0.1), and the molar ratio of component (a) to component (c) is 1:(3-15).

2. The preparation method according to claim 1, characterized in that: The ratio of the molar amount of component (a) to the molar amount of epoxy groups of component (b) is 1:(0.02-0.05); and / or The molar ratio of component (a) to component (c) is 1:(3-10).

3. The preparation method according to claim 1, characterized in that: At least one of the following conditions is met: (1) The component (a) is at least one selected from 4,4'-diaminodicyclohexylmethane and its derivatives, dimethyldiaminocyclohexylmethane and its derivatives; (2) the component (b) is selected from one or more of epoxy resin E51, epoxy resin E20, epoxy resin E54, phenyl glycidyl ether, benzyl glycidyl ether, C12-C14 glycidyl ether, butyl glycidyl ether, 1,4-butanediol diglycidyl ether and 1,2-ethylene glycol diglycidyl ether; (3) The component (c) is at least one selected from polyethylene glycol diglycidyl ether and polypropylene glycol diglycidyl ether.

4. The preparation method according to any one of claims 1 to 3, characterized in that The preparation method comprises the following steps: A. Add component (a) into a reaction vessel, heat and stir; B. adding component (b) into the reaction vessel of step A, reacting to obtain an intermediate product; C. adding component (c) into the reaction vessel of step B, reacting to obtain a reaction product; D. Cooling the reaction product and adding deionized water to obtain a demulsified waterborne epoxy resin curing agent.

5. The preparation method according to claim 3, characterized in that: In step A, the temperature is heated to 70-100°C, preferably 80-90°C.

6. The preparation method according to claim 3, characterized in that: In step B, the reaction conditions are heating and stirring; Optionally, the heating temperature is 70 to 100° C., preferably 80 to 90° C.; Optionally, the reaction time is 0.5 to 3 hours, preferably 1 to 2 hours.

7. The preparation method according to claim 3, characterized in that: In step C, the reaction conditions are heating and stirring; Optionally, the heating temperature is 70 to 100° C., preferably 80 to 90° C.; Optionally, the reaction time is 0.5 to 3 hours, preferably 1 to 2 hours.

8. The preparation method according to claim 4, characterized in that: In step D, after cooling the reaction product to 50-70° C., deionized water at 50-70° C. is added to obtain a demulsified waterborne epoxy resin curing agent; Optionally, adding deionized water and stirring; Optionally, the stirring rate is 1000-3000 rpm.

9. A demulsified waterborne epoxy resin curing agent prepared according to the preparation method according to any one of claims 1 to 8, characterized in that: The HLB value is 6 to 7.

10. A water-based paint, characterized in that: The invention comprises the demulsified waterborne epoxy resin curing agent as described in claim 9.

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