Anticorrosive paint for metal and preparation method thereof

Abstract

The invention relates to the technical field of paint, and particularly discloses anticorrosive paint for metal and a preparation method of the anticorrosive paint. The anticorrosive paint for metal comprises a component A and a component B, the component A comprises an epoxy resin mixture, amino resin and filler; the component B comprises a polyamide curing agent; the epoxy resin mixture comprises glycidyl ether epoxy resin, linear epoxy resin and an epoxy resin diluent; the preparation method comprises the following steps: stirring and mixing the glycidyl ether epoxy resin, the linear epoxy resin and the epoxy resin diluent, adding the amino resin and the filler into the epoxy resin mixture, stirring and mixing, and grinding to obtain the component A; and stirring and mixing the component A and the component B to obtain the anticorrosive paint for the metal. The anticorrosive paint for metal has high adhesive force to a metal base material, can be cured on the surface of the metal base material to form a compact paint film, and has an excellent anticorrosive effect.

Description

Technical Field

[0001] The present application relates to the technical field of paints, and more specifically, to an anti-corrosion paint for metal and a preparation method thereof. Background Art

[0002] Metal anti-corrosion paint is a special paint that can effectively protect metal surfaces from corrosion. It is characterized by strong anti-corrosion ability, good wear resistance, strong oxidation resistance and high safety. Therefore, it is widely used in various industries and fields.

[0003] However, the construction of metal anti-corrosion paint is difficult, and the oil stains, rust and other impurities on the metal surface need to be thoroughly treated before painting. Otherwise, it is easy to cause the paint to fall off, affecting the anti-corrosion effect. Summary of the invention

[0004] In order to improve the adhesion of metal anti-corrosion paint, the present application provides an anti-corrosion paint for metal and a preparation method thereof.

[0005] In the first aspect, the present application provides an anti-corrosion paint for metal, which adopts the following technical solution: An anticorrosive paint for metal, comprising component A and component B; The A component comprises the following components in parts by weight: 25 to 40 parts of epoxy resin mixture; 1 to 5 parts of amino resin; 30 to 45 parts of filler; The B component comprises the following components in parts by weight: 35 to 50 parts of polyamide curing agent; 48 to 64 parts of solvent; The epoxy resin mixture comprises glycidyl ether epoxy resin, linear epoxy resin and epoxy resin diluent.

[0006] By adopting the above technical solution, an epoxy resin mixture formed by mixing glycidyl ether epoxy resin, linear epoxy resin and epoxy resin diluent is used as the main film-forming substance. On the one hand, the epoxy resin diluent has low viscosity and good compatibility with glycidyl ether epoxy resin and linear epoxy resin, and can dilute glycidyl ether epoxy resin and linear epoxy resin, so that the paint has excellent construction fluidity, which is convenient for it to wet on the surface of the substrate to form a dense corrosion-resistant paint film, thereby improving the adhesion of the paint to the substrate. On the other hand, the linear epoxy resin contains one or more epoxy groups, and after cross-linking and curing with glycidyl ether epoxy resin with strong adhesion, the formed paint film has a high cross-linking density, has excellent anti-corrosion performance and adhesion, can be attached to the surface of the substrate, and improve the anti-corrosion performance of the substrate.

[0007] At the same time, the molecular structures of epoxy resins, amino resins, polyamides, etc. have long-chain ester bond structures. After cross-linking and curing, the resulting paint film is plump, brightly colored, hard, tough, has strong adhesion, outstanding insulation properties, and excellent chemical corrosion resistance.

[0008] Preferably, the linear epoxy resin is dicyclopentadiene phenol epoxy resin.

[0009] Preferably, the epoxy equivalent of the dicyclopentadiene phenol epoxy resin is 260 to 280 g / eq, the solid content is 75±1%, and the viscosity is 200 to 800 mPa.s.

[0010] By adopting the above technical solution, dicyclopentadiene phenol epoxy resin is a linear multifunctional epoxy resin with excellent high adhesion and chemical resistance. The paint formulated with it has high adhesion on the substrate and can effectively improve the corrosion resistance of the substrate.

[0011] Preferably, the epoxy diluent is a glycidyl ether type reactive diluent.

[0012] By adopting the above technical solution, the glycidyl ether type active diluent has both low volatility and long open time, and the paint prepared with it has good processing performance, is easy to be coated on the surface of the substrate, and is convenient for construction.

[0013] Preferably, the glycidyl ether type reactive diluent is a monofunctional glycidyl ether type reactive diluent.

[0014] By adopting the above technical scheme, the monofunctional glycidyl ether type active diluent has a moderate curing rate, low viscosity, and strong dilution ability, and the paint prepared with the monofunctional glycidyl ether type active diluent has good construction performance.

[0015] Preferably, the monofunctional glycidyl ether type reactive diluent is octyl glycidyl ether or benzyl glycidyl ether.

[0016] By adopting the above technical scheme, the above-mentioned type of monofunctional glycidyl ether type active diluent has the characteristics of low viscosity, good fluidity, low surface tension, low odor, low toxicity, etc., and has good dilution property for epoxy resin. The paint prepared by using it has good processing performance, strong permeability, and high adhesion on the surface of the substrate.

[0017] Preferably, the epoxy equivalent of the glycidyl ether epoxy resin is 184 to 195 g / eq, and the viscosity is 10000 to 16000 mPa.s.

[0018] By adopting the above technical scheme, in the epoxy diluent environment, low epoxy equivalent glycidyl ether epoxy resin and high epoxy equivalent linear epoxy resin are selected for cross-linking and curing, which has a moderate curing speed, good paint fluidity, excellent permeability, not only high adhesion to the substrate, but also can form a paint film with a high cross-linking density after curing, which is beneficial to improve the adhesion of the paint to the substrate and the anti-corrosion performance.

[0019] Preferably, the epoxy resin mixture is composed of a mixture of a glycidyl ether epoxy resin, a linear epoxy resin and an epoxy resin diluent in a weight ratio of 1:(0.45-0.55):(2.5-3.5).

[0020] By adopting the above technical solution, the glycidyl ether epoxy resin, linear epoxy resin and epoxy resin diluent are mixed in the above proportion, and the three raw materials have good compatibility, and the epoxy resin mixture formed has good construction performance. Therefore, the paint prepared with the above epoxy resin mixture and other raw materials has good fluidity and permeability on the surface of the substrate, which is conducive to improving the adhesion and anti-corrosion performance of the paint to the substrate In a second aspect, the present application provides a method for preparing an anti-corrosion paint for metal, using the following technical solution: A method for preparing an anticorrosive paint for metal comprises the following steps: S1: After the glycidyl ether epoxy resin, the linear epoxy resin and the epoxy resin diluent are stirred and mixed, an epoxy resin mixture is formed; the amino resin and the filler are added to the epoxy resin mixture, stirred and mixed, and ground to obtain component A; The polyamide curing agent and the solvent are stirred and mixed to obtain component B; S2: After mixing component A and component B, an anti-corrosion paint for metal is obtained.

[0021] By adopting the above technical scheme, the glycidyl ether epoxy resin, linear epoxy resin and epoxy resin diluent are first stirred and mixed to make them fully mixed and dispersed to form a stable epoxy resin mixture, and then the amino resin and filler are added to promote the full dispersion and compatibility of various resins and fillers. After cross-linking and curing with a curing agent, it is conducive to forming a dense paint film and improving the anti-corrosion effect on the substrate.

[0022] In summary, this application has the following beneficial effects: 1. The epoxy resin mixture formed by mixing glycidyl ether epoxy resin, linear epoxy resin and epoxy resin diluent has excellent construction fluidity and cross-linking performance. The paint prepared by the mixture can wet and quickly penetrate the metal substrate. After cross-linking and curing, a dense paint film can be formed on the surface of the metal substrate, which is beneficial to improve the anti-corrosion performance and adhesion of the paint; 2. The monofunctional glycidyl ether type active diluent in the present application has a strong dilution ability and can promote full compatibility between resins. The prepared paint has high fluidity, long open time, good wettability and permeability to the metal substrate, which is beneficial to improve the adhesion of the paint to the metal substrate; 3. The method of the present application first uses epoxy diluent to dilute glycidyl ether epoxy resin and linear epoxy resin to obtain an epoxy resin mixture with good fluidity, and then adds amino resin, filler, etc. to mix, so as to facilitate the full mixing of various resins and fillers, which is beneficial to improving the anti-corrosion performance of the paint. DETAILED DESCRIPTION

[0023] The present application is further described in detail below with reference to the embodiments.

[0024] The raw materials used in the examples of the present application are commercially available unless otherwise specified below.

[0025] Amino resin, CYMEL-325; The filler is precipitated barium sulfate; Polyamide curing agent, brand name YS-8115, purchased from Shanghai Yaoshan Industrial Co., Ltd.; The solvent is xylene; Drier, brand DMP-30.

[0026] Performance Testing The anti-corrosion paint for metal prepared in the examples of the present application and the anti-corrosion paint prepared in the comparative example were tested for adhesion, flexibility and corrosion resistance. The testing method is as follows: Adhesion: Tested in accordance with GB / T 5210-2006 standard; Flexibility: Tested in accordance with GBT 1731-2020 standard; Corrosion resistance test: (1) Using a sandblasted steel plate as a substrate, the same sandblasted steel plate is first degreased and derusted, then cut to form a number of specimens, and finally paint is sprayed on the surface of the specimens, and after curing at room temperature, a sample is obtained; (2) Under the conditions of temperature 23±2°C and humidity (50±5)%, the samples were immersed in 25wt% sulfuric acid solution and 30wt% sodium hydroxide solution, respectively, covered and sealed, and immersed for 500 hours, and then the paint film was observed for peeling, shedding, and rusting. Under the conditions of temperature 23±2°C and humidity (50±5)%, the samples were immersed in 3.5wt% sodium chloride solution, covered and sealed, and immersed for 3 months, and then the paint film was observed for peeling, shedding, and rusting. Example

[0027] Example 1 An anti-corrosion paint for metal, the components and their corresponding weights (kg) are shown in the following table.

[0028] The method for preparing the above-mentioned anticorrosive paint for metal comprises the following steps: S1: After the glycidyl ether epoxy resin, the linear epoxy resin and the epoxy resin diluent are stirred and mixed, the temperature is raised to 120°C to 160°C (120°C in the embodiment of the present application) at a rate of 2°C / min to 5°C / min (2°C / min in the embodiment of the present application), the reaction is carried out for 100min to 150min (100min in the embodiment of the present application), the heating is stopped, and the mixture is cooled to 40°C to 60°C (400°C in the embodiment of the present application) to obtain an epoxy resin mixture; Add the amino resin and filler to the epoxy resin mixture, stir and mix at 800-1200 r / min (800 r / min in the embodiment of the present application) for 10-45 min (20 min in the embodiment of the present application), and grind to obtain component A; The polyamide curing agent, the solvent and the drying agent are stirred and mixed, and stirred and mixed at 800 to 1200 r / min (800 r / min in the embodiment of the present application) for 5 to 20 min (20 min in the embodiment of the present application) to obtain component B; S2: After mixing component A and component B, an anti-corrosion paint for metal is obtained.

[0029] In the embodiment of the present application, the glycidyl ether epoxy resin is bisphenol A epoxy resin, the brand is WSR618, the epoxy equivalent is 184-195 g / eq, and the viscosity is 10000-16000 mPa.s; Linear epoxy resin, dicyclopentadiene phenol epoxy resin, model EMTE310-A75, epoxy equivalent weight of 260-280 g / eq, solid content of 75±1%, viscosity of 200-800 mPa.s; The epoxy resin diluent is benzyl glycidyl ether; The weight ratio of component A to component B is 1:2.5.

[0030] Embodiment 2-3 An anti-corrosion paint for metal, which is different from Example 1 in that the components and their corresponding weights (kg) are shown in the following table.

[0031] The anti-corrosion paints for metal prepared in Examples 1 to 3 of the present application were tested for adhesion, flexibility and corrosion resistance. The test results are shown in the following table.

[0032] By analyzing the data in the above table, it can be seen that the anticorrosive paint for metal prepared in Examples 1 to 3 has an adhesion of up to 11.6 to 13.5 MPa and a flexibility of up to 1 to 2 mm. After being immersed in 25% wt sulfuric acid solution and 30% wt sodium hydroxide solution for 500 hours, the paint film has no bubbles, no shedding, and no rust. After being immersed in 3.5 wt% sodium chloride solution for 3 months, the paint film has no bubbles, no shedding, and no rust. This shows that the anticorrosive paint for metal prepared in Examples 1 to 3 of the present application has high adhesion, flexibility and corrosion resistance.

[0033] Embodiments 4 to 7 An anti-corrosion paint for metal, which is different from Example 1 in that the components and their corresponding weights (kg) in the epoxy resin mixture are shown in the following table.

[0034] The anti-corrosion paints for metal prepared in Examples 4 to 7 of the present application were tested for adhesion, and the test results are shown in the following table.

[0035] By analyzing the data in the above table, it can be seen that the anti-corrosion paint for metal prepared in Examples 1, 4 to 5 has an adhesion of up to 12.6 to 13.2 MPa. The anti-corrosion paint for metal prepared in Examples 6 and 7 has a significantly lower adhesion than the anti-corrosion paint for metal prepared in Examples 1, 4 to 5. This shows that in the total raw materials for the preparation of the anti-corrosion paint for metal in the present application, when the epoxy resin mixture is composed of a glycidyl ether epoxy resin, a linear epoxy resin and an epoxy resin diluent in a weight ratio of 1: (0.45 to 0.55): (2.5 to 3.5), the adhesion of the paint can be improved. The reason for this may be that the epoxy resin mixture prepared by mixing in the above weight ratio has good construction performance, so the paint prepared by using it has good fluidity and permeability on the surface of the substrate, which is conducive to the adhesion of the paint to the surface of the substrate, thereby improving the adhesion of the paint to the substrate.

[0036] Example 8 An anti-corrosion paint for metal, which is different from Example 1 in that the glycidyl ether epoxy resin is bisphenol A epoxy resin with a brand name of E-20 and an epoxy equivalent of 454 to 555 g / eq.

[0037] Example 9 An anticorrosive paint for metal, which is different from Example 1 in that the linear epoxy resin is Huntsman EPN 1179 resin.

[0038] Example 10 An anti-corrosion paint for metal, which is different from Example 1 in that the glycidyl ether type active diluent is polyethylene glycol diglycidyl ether.

[0039] Embodiment 11 An anti-corrosion paint for metal, which is different from Example 1 in that the epoxy diluent is xylene.

[0040] The anti-corrosion paints for metal prepared in Examples 8 to 11 of the present application were tested for adhesion, flexibility and corrosion resistance. The test results are shown in the following table.

[0041] By analyzing the data in the above table, it can be seen that compared with Example 1, the adhesion and flexibility of Example 8 are both reduced. After being immersed in 25%wt sulfuric acid solution and 30%wt sodium hydroxide solution for 500h, the paint film has a small amount of blistering, no shedding, and a small amount of rust. This shows that in the total raw materials for preparing the anti-corrosion paint for metal of the present application, the epoxy equivalent of the glycidyl ether epoxy resin is selected to be 184-195g / eq and the viscosity is 10000-16000mPa.s, which can improve the adhesion, flexibility and corrosion resistance of the paint.

[0042] Compared with Example 1, the adhesion and flexibility of Example 9 are both reduced. After being immersed in 25%wt sulfuric acid solution and 30%wt sodium hydroxide solution for 500h, the paint film has a small amount of blistering, no shedding, and a small amount of rust. This shows that in the total raw materials for preparing the anti-corrosion paint for metal of the present application, the linear epoxy resin selected is dicyclopentadiene phenol epoxy resin, which can improve the adhesion, flexibility and corrosion resistance of the paint.

[0043] Compared with Example 1, the adhesion of Examples 10 and 11 is reduced. This shows that in the total raw materials for preparing the anti-corrosion paint for metal of the present application, the epoxy resin diluent is a monofunctional glycidyl ether type active diluent, which can improve the adhesion of the paint.

[0044] Comparative Example Comparative Example 1 An anti-corrosion paint, which is different from Example 1 in that an equal weight of glycidyl ether epoxy resin WSR618 is used to replace the linear epoxy resin EMTE310-A75.

[0045] Comparative Example 2 An anti-corrosion paint, which is different from Example 1 in that an equal weight of glycidyl ether epoxy resin WSR618 is used to replace the epoxy resin mixture.

[0046] The anti-corrosion paints prepared in Comparative Examples 1 to 2 of the present application were tested for adhesion, flexibility and corrosion resistance. The test results are shown in the following table.

[0047] By analyzing the data in the above table, it can be seen that compared with Example 1, the adhesion of Comparative Example 1 is relatively reduced by 24.24%, and the flexibility is reduced. After immersion in 25%wt sulfuric acid solution and 30%wt sodium hydroxide solution for 500h, the paint film has a large amount of bubbles, partial shedding, and a large amount of rust. After immersion in 3.5wt% sodium chloride solution for 3 months, the paint film has a small amount of bubbles, partial shedding, and a small amount of rust.

[0048] Compared with Example 1, the adhesion of Comparative Example 2 is relatively reduced by 29.55%, and the flexibility is reduced. After being immersed in 25%wt sulfuric acid solution and 30%wt sodium hydroxide solution for 500h, the paint film has a lot of bubbles, most of it falls off, and a lot of rust. After being immersed in 3.5wt% sodium chloride solution for 3 months, the paint film has a lot of bubbles, part of it falls off, and a lot of rust.

[0049] This shows that in the total raw materials for preparing the anti-corrosion paint for metal in the present application, the epoxy resin mixture prepared by mixing glycidyl ether epoxy resin, linear epoxy resin and epoxy resin diluent is used as the main film-forming substance, which can improve the adhesion, flexibility and corrosion resistance of the anti-corrosion paint for metal.

[0050] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make modifications to the present embodiment without any creative contribution as needed, but such modifications are protected by the patent law as long as they are within the scope of the claims of the present application.

Claims

1. An anticorrosive paint for metal, characterized in that: It includes component A and component B; The A component comprises the following components in parts by weight: 25 to 40 parts of epoxy resin mixture; 1 to 5 parts of amino resin; 30 to 45 parts of filler; The B component comprises the following components in parts by weight: 35 to 50 parts of polyamide curing agent; The epoxy resin mixture comprises glycidyl ether epoxy resin, linear epoxy resin and epoxy resin diluent.

2. The anticorrosive paint for metal according to claim 1, characterized in that: The linear epoxy resin is dicyclopentadiene phenol epoxy resin.

3. The anticorrosive paint for metal according to claim 2, characterized in that: The epoxy equivalent of the dicyclopentadiene phenol epoxy resin is 260-280 g / eq, the solid content is 75±1%, and the viscosity is 200-800 mPa.s.

4. The anticorrosive paint for metal according to claim 1, characterized in that: The epoxy diluent is a glycidyl ether type active diluent.

5. The anticorrosive paint for metal according to claim 4, characterized in that: The glycidyl ether type active diluent is a monofunctional glycidyl ether type active diluent.

6. The anticorrosive paint for metal according to claim 5, characterized in that: The monofunctional glycidyl ether type active diluent is octyl glycidyl ether or benzyl glycidyl ether.

7. The anticorrosive paint for metal according to claim 1, characterized in that: The epoxy equivalent of the glycidyl ether epoxy resin is 184-195 g / eq, and the viscosity is 10000-16000 mPa.s.

8. The anticorrosive paint for metal according to claim 1, characterized in that: The epoxy resin mixture is composed of a mixture of glycidyl ether epoxy resin, a linear epoxy resin and an epoxy resin diluent in a weight ratio of 1: (0.45-0.55): (2.5-3.5).

9. The method for preparing the anticorrosive paint for metal according to any one of claims 1 to 8, characterized in that: The following steps are involved: S1: After the glycidyl ether epoxy resin, the linear epoxy resin and the epoxy resin diluent are stirred and mixed, an epoxy resin mixture is formed; the amino resin and the filler are added to the epoxy resin mixture, stirred and mixed, and ground to obtain component A; S2: After mixing component A and component B, an anti-corrosion paint for metal is obtained.

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