Quick-drying zinc phosphate epoxy paint and preparation method thereof

Abstract

The invention belongs to the technical field of coatings, and particularly relates to quick-drying zinc phosphate epoxy paint and a preparation method thereof. The quick-drying zinc phosphate epoxy paint comprises a component A and a component B. The component A is prepared from, by mass, 10-20 parts of epoxy resin, 4-10 parts of petroleum resin, 5-10 parts of a resin modifier, 0.5-1.5 parts of an anti-settling agent, 0.5-1 part of a dispersing agent, 0.5-1 part of a defoaming agent, 0.1-0.7 part of a silane coupling agent, 60-70 parts of pigment filler and 8-15 parts of an organic solvent. And the component B is a modified amine curing agent. According to the invention, the epoxy resin with strong corrosion resistance, wear resistance and impact resistance is matched with the resin modifier to improve the flexibility; petroleum resin is matched, so that the hardness of the paint is improved, and the drying speed of a paint film can be increased; and the anti-settling agent is added to improve the thixotropy of the paint so as to improve the sagging resistance and storage stability of the paint. A certain amount of zinc phosphate is added, so that the paint has good anti-rust performance and waterproof performance. And finally, matching with a self-made modified amine curing agent to finally obtain the quick-drying high-sagging anti-corrosion epoxy coating.

Description

Technical Field

[0001] The invention belongs to the technical field of coatings, and in particular relates to a quick-drying zinc phosphate epoxy paint and a preparation method thereof. Background Art

[0002] Epoxy coatings have always been the most frequently used coatings in chemical anti-corrosion, railway wind power and other construction fields. However, conventional epoxy coatings have a slow drying speed and poor sagging performance. Therefore, in order to ensure a beautiful appearance without sagging during construction, multiple coats of spraying are often required. The second coat is sprayed after the first coat of paint is dry, so that a better appearance can be guaranteed when the paint film thickness requirement is high. However, when epoxy paint dries slowly, it usually increases the construction period and is more troublesome. Summary of the invention

[0003] The present invention aims to solve the above problems and provides a quick-drying zinc phosphate epoxy paint and a preparation method thereof, which adopts a modified amine curing agent as a curing agent, has quick-drying, high anti-sagging properties and excellent anti-corrosion properties.

[0004] According to the technical solution of the present invention, the quick-drying zinc phosphate epoxy paint comprises component A and component B. The component A comprises, by mass: 10-20 parts of epoxy resin, 4-10 parts of petroleum resin, 5-10 parts of resin improver, 0.5-1.5 parts of anti-settling agent, 0.5-1 parts of dispersant, 0.5-1 parts of defoamer, 0.1-0.7 parts of silane coupling agent, 60-70 parts of pigment and filler, and 8-15 parts of organic solvent; The component B is a modified amine curing agent, which is prepared by introducing a polyamine monomer into the main chain of a cardanol formal resin.

[0005] Furthermore, the equivalent ratio of the epoxy group of the epoxy resin in the component A to the active hydrogen of the component B is 1:(0.5-1).

[0006] Furthermore, at least one of the following conditions is met: The epoxy resin is selected from 601-75S and / or 128; The petroleum resin is selected from C9 petroleum resin or C5 petroleum resin; The resin improver is selected from WSCM-5110 or NX-2022; The anti-settling agent is selected from 8800k polyamide wax powder and / or Y7071 bentonite; The dispersant is selected from HD5006 or WELLMIX-1633; The defoamer is selected from BYK-052N, Q-066 or WELLMIX-2085; The silane coupling agent is selected from coupling agent KH-550 or KH560; The color filler is selected from one or more of silicon dioxide, talc, calcium carbonate, zinc phosphate and pigment; The organic solvent is selected from one or more of xylene, n-butanol, isopropanol and propylene glycol.

[0007] Furthermore, the polyamine is selected from triethylenetetramine and m-xylylenediamine, and the cardanol formal resin is obtained by reacting cardanol and formaldehyde solution.

[0008] Furthermore, the modified amine curing agent is prepared by the following method: S1: adding ammonium chloride solution to the mixed solution of cardanol and formaldehyde solution, heating at 90-100° C. to react, to obtain cardanol formal resin; S2: under heat preservation conditions, adding polyamine to the cardanol formal resin, separating after reaction, and obtaining the modified amine curing agent.

[0009] Furthermore, in step S1, the concentration of the formaldehyde solution is 30-45%, the concentration of the ammonium chloride solution is 5-10%, and the mass ratio of cardanol, formaldehyde solution and ammonium chloride solution is (10-15): (2-6): (1-2).

[0010] Furthermore, in step S2, the polyamines are triethylenetetramine and meta-xylenediamine, the mass ratio of the added amount of triethylenetetramine to cardanol is (6-10): (10-15), and the mass ratio of the added amount of meta-xylenediamine to cardanol is (2-4): (10-15).

[0011] Furthermore, in step S1, the heating reaction time is 0.8-1.5 h; in step S2, the reaction time is 0.8-1.5 h, and the separation method after the reaction is distillation.

[0012] The second aspect of the present invention provides a method for preparing the above-mentioned quick-drying zinc phosphate epoxy paint, comprising the following steps: S1: Epoxy resin and petroleum resin are dispersed in part of the organic solvent to dissolve all the petroleum resin; S2: adding a resin improver and a dispersant to the mixed system obtained in step S1; S3: adding an anti-settling agent to the mixed system obtained in step S2; S4: Add pigments, fillers, silane coupling agents and defoamers to the mixed system obtained in S3 in sequence, keep the mixture at 55-65°C for 15-40 minutes, and then adjust the viscosity to 120±10ku with the remaining organic solvent to obtain component A; S5: combining the obtained component A with a modified amine curing agent to obtain the quick-drying zinc phosphate epoxy paint.

[0013] Furthermore, when in use, component A is mixed evenly with the modified amine curing agent, and diluted with epoxy diluent to 60-70 ku.

[0014] The technical solution of the present invention has the following advantages over the prior art: The present invention adopts epoxy resin with strong corrosion resistance, wear resistance and impact resistance and is matched with a resin improver to improve its flexibility. At the same time, petroleum resin is matched to improve the hardness of the paint and can help to accelerate the drying speed of the paint film. Anti-settling agent is added to improve the thixotropy of the paint to improve the anti-sagging property and storage stability of the paint. A certain amount of zinc phosphate is added to make the paint have good anti-rust and waterproof properties. Finally, a homemade modified amine curing agent is matched to finally obtain a fast-drying high-sagging anti-corrosion epoxy coating. DETAILED DESCRIPTION

[0015] The invention provides a quick-drying zinc phosphate epoxy paint, which is a base-medium-in-one atmospheric protective paint applicable in all seasons. The paint has a fast drying speed, can be sprayed three times a day, and has a sag far exceeding that of ordinary epoxy paint, which can reach 800 μm. The VOC content is very low and the anti-corrosion performance is excellent. The paint is an environmentally friendly, quick-drying anti-corrosion paint.

[0016] Specifically, the equivalent ratio of epoxy group (epoxy group of epoxy resin in component A) to active hydrogen (active hydrogen of component B) is 1:(0.5-1) component A and component B, wherein: Component A includes, by mass: 10-20 parts of epoxy resin, 4-10 parts of petroleum resin, 5-10 parts of resin improver, 0.5-1.5 parts of anti-settling agent, 0.5-1 parts of dispersant, 0.5-1 parts of defoamer, 0.1-0.7 parts of silane coupling agent, 60-70 parts of pigment and filler, and 8-15 parts of organic solvent; Component B is a modified amine curing agent, which is prepared by introducing a polyamine monomer into the main chain of the cardanol formal resin.

[0017] In some preferred embodiments, the epoxy resin uses 601-75S, Yuanbang 128 epoxy resin, or Nan Ya 128 epoxy resin, which can make the coating have strong adhesion, excellent chemical resistance, water resistance, and corrosion resistance.

[0018] The petroleum resin is selected from C9 petroleum resin or C5 petroleum resin, which can improve the weather resistance, hardness and wear resistance of the coating and accelerate its drying speed.

[0019] The resin improver is selected from WSCM-5110 or Cardolite NX-2022, which can effectively improve the mechanical properties such as wear resistance, impact resistance, toughness, weather resistance and chemical resistance of the coating.

[0020] The anti-settling agent is selected from 8800k polyamide wax powder or Y7071 bentonite, which can effectively prevent the stratification of the paint system and the sedimentation of pigments and fillers, and can make the pigments evenly dispersed in the paint system, increase storage stability, make the paint have strong thixotropic properties, effectively control sagging, and make construction convenient.

[0021] The dispersant is selected from HD5006 or WELLMIX-1633, which can effectively disperse the pigments and fillers in the formula and increase the stability of the system.

[0022] The defoamer is selected from BYK-052N, Q-066 or WELLMIX-2085, which can effectively solve the foaming during the paint stirring process and make the paint film smooth and free of bubbles.

[0023] The silane coupling agent is selected from coupling agent KH-550 or KH560, which can improve the performance of the resin, enhance the adhesion between the coating and the substrate, and improve the durability of the coating.

[0024] The color filler is selected from one or more of silicon dioxide, talc, calcium carbonate, zinc phosphate and pigments. The combination of silicon dioxide, talc and calcium carbonate can improve the hardness of the coating, and has good wear resistance, and makes the paint film present a semi-matte appearance. Zinc phosphate can form a dense passivation film in the paint, which can effectively improve the anti-corrosion performance of the coating and increase the drying speed of the coating. Red iron oxide can improve the hiding power, light resistance, heat resistance and chemical resistance of the paint.

[0025] The organic solvent is selected from one or more of xylene, n-butanol, isopropanol and propylene glycol.

[0026] In some preferred embodiments, the polyamine is selected from triethylenetetramine and m-xylenediamine, and the cardanol formal resin is obtained by reacting cardanol with a formaldehyde solution. Among them, cardanol is a natural biomass phenol with unique long-chain alkanes. After reacting with formaldehyde to obtain the cardanol formal resin, triethylenetetramine and m-xylenediamine are introduced at the same time, thereby preparing a modified amine curing agent with fast room temperature solid content, good chemical resistance, high flexibility and good adhesion.

[0027] Specifically, the modified amine curing agent can be prepared by the following method: S1: adding ammonium chloride solution to the mixed solution of cardanol and formaldehyde solution, heating at 90-100° C. for reaction for 0.8-1.5 h to obtain cardanol formal resin; S2: under heat preservation conditions, adding polyamine to the obtained cardanol formal resin, and distilling and separating water molecules for 0.8-1.5 hours after the reaction to obtain a modified amine curing agent.

[0028] Specifically: in step S1, the concentration of the formaldehyde solution is 30-45%, the concentration of the ammonium chloride solution is 5-10%, and the mass ratio of cardanol, formaldehyde solution and ammonium chloride solution is (10-15): (2-6): (1-2). In step S2, the polyamines are triethylenetetramine and m-xylenediamine, and the mass ratio of the amount of triethylenetetramine added to cardanol is (6-10): (10-15); the mass ratio of the amount of m-xylenediamine added to cardanol is (2-4): (10-15).

[0029] The above-mentioned quick-drying zinc phosphate epoxy paint can be prepared by the following steps: S1: Epoxy resin and petroleum resin are dispersed in part of the organic solvent to dissolve all the petroleum resin; S2: adding a resin improver and a dispersant to the mixed system obtained in step S1, and stirring evenly; S3: adding an anti-settling agent to the mixed system obtained in step S2, and dispersing at high speed for 20 minutes; S4: Add pigments, fillers, silane coupling agents and defoamers to the mixed system obtained in S3 in sequence, keep the mixture at 55-65°C for 15-40 minutes, and then adjust the viscosity to 120±10ku with the remaining organic solvent to obtain component A; S5: combining the obtained component A with a modified amine curing agent to obtain a fast-drying zinc phosphate epoxy paint.

[0030] During use, mix component A and modified amine curing agent evenly, and dilute to 60-70ku with epoxy diluent (such as xylene: n-butanol = 7:3), and apply it on the sandblasted carbon steel substrate to obtain a quick-drying zinc phosphate epoxy paint coating.

[0031] The present invention is further described below in conjunction with specific embodiments so that those skilled in the art can better understand the present invention and implement it, but the embodiments are not intended to limit the present invention.

[0032] In the following embodiments, the epoxy resin is Yuanbang 128, the petroleum resin is C9 petroleum resin, the resin improver is NX-2022, the anti-settling agent is 8800k polyamide wax powder, the dispersant is WELLMIX-1633, the defoaming agent is BYK-052N, the silane coupling agent is KH560, the color filler is a mixture of silicon dioxide, talc, calcium carbonate, zinc phosphate and red iron oxide, and the organic solvent is a mixture of xylene and PM (1-methoxy-2-propanol).

[0033] The raw materials of the modified amine curing agent include, by weight: 12 parts of cardanol, 4 parts of formaldehyde solution (37%), 1.5 parts of ammonium chloride solution (10%), 8 parts of triethylenetetramine, and 3 parts of triethylenetetramine. The preparation method is as follows: Add the above-mentioned cardanol components to a flask equipped with a thermometer and a condensation reflux device, add the above-mentioned formaldehyde solution while stirring, heat to 90-100°C in an oil bath, add ammonium chloride solution as a catalyst, keep warm and react for 1 hour to obtain cardanol formal resin. Then add the above-mentioned triethylenetetramine components dropwise, and continue to react for 1 hour after constant temperature reflux for 10 minutes after the addition is completed. After the active hydrogen in the triethylenetetramine is condensed with the hydroxymethyl of the cardanol formal resin, the polyamine monomer is introduced into the main chain of the cardanol formal resin to obtain the desired final product. Distill and separate the water molecules to obtain the desired modified amine curing agent. Example 1

[0034] Component A, calculated by mass, includes: 14 parts of epoxy resin, 8 parts of petroleum resin, 8 parts of resin improver, 0.8 parts of anti-settling agent, 1 part of dispersant, 1.2 parts of defoaming agent, 0.5 parts of silane coupling agent, 28 parts of silicon dioxide, 8 parts of talc, 15 parts of calcium carbonate, 3 parts of zinc phosphate, 6 parts of pigment (red iron oxide), 6 parts of xylene, and 2.5 parts of PM.

[0035] The preparation method is as follows: S1: Add 14 parts of epoxy resin, 8 parts of petroleum resin, 8 parts of resin improver, 3 parts of xylene and 2.5 parts of PM into the kettle in sequence, stir at 1500 rpm for about 30 minutes to dissolve the petroleum resin; S2: Add 1 part of dispersant into S1 and disperse evenly, add 0.8 part of anti-settling agent while stirring, and disperse for 20 minutes to fully dissolve; S3: 1.2 parts of defoamer, 0.5 parts of silane coupling agent, 28 parts of silicon dioxide, 8 parts of talc, 15 parts of calcium carbonate, 3 parts of zinc phosphate and 6 parts of red iron oxide are added into the S2 system in sequence. The system temperature is raised to 60°C by high-speed dispersion and kept warm for 20 minutes. Finally, the viscosity is adjusted to 120±10ku with the remaining solvent. Example 2

[0036] Component A, calculated by mass, includes: 16 parts of epoxy resin, 6 parts of petroleum resin, 6 parts of resin improver, 1 part of anti-settling agent, 1 part of dispersant, 1.2 parts of defoaming agent, 0.5 parts of silane coupling agent, 28 parts of silicon dioxide, 8 parts of talc, 15 parts of calcium carbonate, 3 parts of zinc phosphate, 6 parts of red iron oxide, 6 parts of xylene, and 2.3 parts of PM.

[0037] The preparation method is the same as that of Example 1. Example 3

[0038] Component A, calculated by mass, includes: 16 parts of epoxy resin, 5 parts of petroleum resin, 7 parts of resin improver, 1 part of anti-settling agent, 1 part of dispersant, 1.2 parts of defoaming agent, 0.5 parts of silane coupling agent, 28 parts of silicon dioxide, 11 parts of talc, 15 parts of calcium carbonate, 6 parts of red iron oxide, 6 parts of xylene, and 2.3 parts of PM.

[0039] The preparation method is the same as that of Example 1.

[0040] 1. Component A in Examples 1-3 was mixed with common epoxy curing agent Sunmide305-70X (referred to as common) and modified amine curing agent (referred to as homemade) at an equivalent ratio of epoxy equivalent: active hydrogen equivalent = 1:0.8 and stirred evenly. The drying speed of six uniformly mixed paints was tested. The test results are shown in Table 1.

[0041] 2. It can be clearly seen from the test results in Table 1 that the homemade modified amine curing agent can significantly increase the drying speed of the paint film.

[0042] The components A in Examples 1-3 were respectively mixed with modified amine curing agents (referred to as homemade) at an equivalent ratio of epoxy equivalent: active hydrogen equivalent = 1:0.8 and evenly stirred, and tested according to performance test indicators. The results are shown in Table 2.

[0043]

[0044] From the test results in Table 2, it can be seen that 8800k polyamide wax powder can significantly improve the sagging performance of paint, increase the thixotropy of paint, and improve the storage performance of paint when used at 1% by weight. Zinc phosphate can significantly improve the anti-corrosion performance of the paint film in the system of this fast-drying epoxy coating. The salt spray resistance test can reach the C5-M standard in ISO12944, and it also has a certain improvement in drying speed.

[0045] Compared with traditional epoxy coatings on the market, the quick-drying zinc phosphate epoxy paint of the present invention is an environmentally friendly anti-corrosion paint with low VOC emissions. It ensures the excellent performance of epoxy products while improving their anti-corrosion performance. In combination with a homemade modified amine curing agent, the drying speed of the paint is significantly improved, and at the same time, it has very high anti-sagging performance. While reducing the pollution of paint construction to the environment for customer units, it also makes the construction more convenient, saving customers' construction costs and time. The present invention uses zinc phosphate filler to improve its anti-corrosion performance and further improves its drying speed. The use of homemade modified amine resin enables the product to overcome the previous defects of slow drying speed and poor sagging index, providing a new idea for the research and development of epoxy paint.

[0046] Obviously, the above embodiments are merely examples for 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 protection scope of the invention.

Claims

1. A quick-drying zinc phosphate epoxy paint, comprising component A and component B, characterized in that: The component A comprises, by mass: 10-20 parts of epoxy resin, 4-10 parts of petroleum resin, 5-10 parts of resin improver, 0.5-1.5 parts of anti-settling agent, 0.5-1 parts of dispersant, 0.5-1 parts of defoamer, 0.1-0.7 parts of silane coupling agent, 60-70 parts of pigment and filler, and 8-15 parts of organic solvent; The component B is a modified amine curing agent, which is prepared by introducing a polyamine monomer into the main chain of a cardanol formal resin.

2. The quick-drying zinc phosphate epoxy paint according to claim 1, characterized in that: The equivalent ratio of the epoxy group of the epoxy resin in the component A to the active hydrogen of the component B is 1:(0.5-1).

3. The quick-drying zinc phosphate epoxy paint according to claim 1 or 2, characterized in that: At least one of the following conditions is met: The epoxy resin is selected from 601-75S and / or 128; The petroleum resin is selected from C9 petroleum resin or C5 petroleum resin; The resin improver is selected from WSCM-5110 or NX-2022; The anti-settling agent is selected from 8800k polyamide wax powder and / or Y7071 bentonite; The dispersant is selected from HD5006 or WELLMIX-1633; The defoamer is selected from BYK-052N, Q-066 or WELLMIX-2085; The silane coupling agent is selected from coupling agent KH-550 or KH560; The color filler is selected from one or more of silicon dioxide, talc, calcium carbonate, zinc phosphate and pigment; The organic solvent is selected from one or more of xylene, n-butanol, isopropanol and propylene glycol.

4. The quick-drying zinc phosphate epoxy paint according to claim 1, characterized in that: The polyamine is selected from triethylenetetramine and m-xylylenediamine, and the cardanol formal resin is obtained by reacting cardanol with a formaldehyde solution.

5. The quick-drying zinc phosphate epoxy paint according to claim 1, characterized in that: The modified amine curing agent is prepared by the following method: S1: adding ammonium chloride solution to the mixed solution of cardanol and formaldehyde solution, heating at 90-100° C. to react, to obtain cardanol formal resin; S2: under heat preservation conditions, adding polyamine to the cardanol formal resin, separating after reaction, and obtaining the modified amine curing agent.

6. The quick-drying zinc phosphate epoxy paint as claimed in claim 5, characterized in that: In step S1, the concentration of the formaldehyde solution is 30-45%, the concentration of the ammonium chloride solution is 5-10%, and the mass ratio of cardanol, formaldehyde solution and ammonium chloride solution is (10-15): (2-6): (1-2).

7. The quick-drying zinc phosphate epoxy paint as claimed in claim 5, characterized in that: In step S2, the polyamines are triethylenetetramine and meta-xylenediamine, the mass ratio of the added amount of triethylenetetramine to cardanol is (6-10): (10-15), and the mass ratio of the added amount of meta-xylenediamine to cardanol is (2-4): (10-15).

8. The quick-drying zinc phosphate epoxy paint as claimed in claim 5, characterized in that: In the step S1, the heating reaction time is 0.8-1.5 hours; in the step S2, the reaction time is 0.8-1.5 hours, and the separation method after the reaction is distillation.

9. A method for preparing the quick-drying zinc phosphate epoxy paint according to any one of claims 1 to 8, characterized in that: The following steps are included: S1: Epoxy resin and petroleum resin are dispersed in part of the organic solvent to dissolve all the petroleum resin; S2: adding a resin improver and a dispersant to the mixed system obtained in step S1; S3: adding an anti-settling agent to the mixed system obtained in step S2; S4: Add pigments, fillers, silane coupling agents and defoamers to the mixed system obtained in S3 in sequence, keep the mixture at 55-65°C for 15-40 minutes, and then adjust the viscosity to 120±10ku with the remaining organic solvent to obtain component A; S5: combining the obtained component A with a modified amine curing agent to obtain the quick-drying zinc phosphate epoxy paint.

10. The preparation method according to claim 9, characterized in that: When in use, mix component A and modified amine curing agent evenly, and dilute with epoxy diluent to 60-70ku.

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