Waterborne epoxy anticorrosive primer and preparation method thereof

Abstract

The invention relates to the field of epoxy anti-corrosion primer, and discloses waterborne epoxy anti-corrosion primer and a preparation method thereof, and the waterborne epoxy anti-corrosion primer is composed of a component A and a component B, the component A is prepared from the following raw materials in parts by weight: 5-25 parts of water, 1-3 parts of a dispersing agent, 30-40 parts of pigment and filler, 1-8 parts of an anti-rust pigment, 0.1-1 part of a defoaming agent, 0.1-1 part of a pigment and filler wetting agent, 0.5-2 parts of water-based organic bentonite, 30-40 parts of a water-based epoxy emulsion, 0.5-1 part of a base material wetting agent, 0.2-1 part of a cosolvent, 0.5-2 parts of an anti-flash rust agent and 0-0.5 part of a silane coupling agent; the component B is prepared from the following raw materials in parts by weight: 10-40 parts of a water-based polyamide epoxy curing agent, 0-2 parts of nano silicon dioxide aerogel and 60-90 parts of water; the mass ratio of the component A to the component B is (6-12): 1, the salt fog resistance time of the prepared waterborne epoxy anticorrosive primer is higher than that of a contrast, the crosslinking density of the two components is higher, the initial protection is improved by the flash rust inhibitor, and the corrosion inhibition effect of single aluminum triphosphate is better due to the compounding of zinc phosphate and aluminum triphosphate.

Description

Technical Field

[0001] The present invention relates to the field of epoxy anticorrosive primers, and in particular to a waterborne epoxy anticorrosive primer and a preparation method thereof. Background Art

[0002] Water-based epoxy anti-corrosion primers are primarily used as intermediate coats on container exteriors and interiors. They are generally used as anti-corrosion primers for industrial applications (such as construction machinery and steel structures). With recent developments in container construction, the required product properties have become more stringent than those of older versions. Customers have reduced construction times from 3 minutes per TEU to 1 minute per TEU. These changes in construction conditions have led to the following product requirements: 1. Dry quickly, both surface drying and actual drying should be fast; 2. Under the premise of fast drying, the main agent and curing agent have a long working life after mixing, which can avoid waste; 3. Fewer pinholes, because the surfactant of water-based paint will foam, which makes water-based paint prone to foaming. It is necessary for the bubbles to be quickly removed from the paint film (before the surface is dry) to make the dry film dense and thus have good anti-corrosion performance; 4. Good anti-corrosion performance; 5. The inner paint needs to have good wear resistance to prevent the loading from falling off; 6. Good mechanical properties, preventing the container from falling off due to impact, adhesion, impact, flexibility, etc. Summary of the Invention

[0003] In view of the shortcomings of the prior art, the present invention solves the technical problems by adopting the following technical solutions: the waterborne epoxy anticorrosive primer of the present invention is composed of two components A and B; Component A is prepared from the following raw materials in parts by weight: 5-25 parts of water, 1-3 parts of dispersant, 30-40 parts of pigments and fillers, 1-8 parts of anti-rust pigments, 0.1-1 parts of defoaming agent, 0.1-1 parts of pigment and filler wetting agent, 0.5-2 parts of water-based organic bentonite, 30-40 parts of water-based epoxy emulsion, 0.5-1 parts of substrate wetting agent, 0.2-1 parts of cosolvent, 0.5-2 parts of anti-flash rust agent and 0-0.5 parts of silane coupling agent; Component B is prepared from the following raw materials in parts by weight: 10-40 parts of water-based polyamide epoxy curing agent, 0-2 parts of nano-silica aerogel and 60-90 parts of water; The mass ratio of component A to component B is 6-12:1.

[0004] Preferably, the pigments and fillers are titanium dioxide, red iron oxide, yellow iron oxide, precipitated barium sulfate, talc, wollastonite powder or mica powder.

[0005] Preferably, the anti-rust pigment is a mixture of one or more of zinc phosphate and aluminum tripolyphosphate.

[0006] Preferably, the defoaming agent is silicone mineral oil.

[0007] Preferably, the cosolvent is PNB or DPNB.

[0008] A method for preparing a waterborne epoxy anticorrosive primer comprises the following steps: Step 1: Add the anti-rust pigment and silane coupling agent into a high-speed mixer and dry mix them at 80°C for 15 minutes to allow the silane to coat the pigment surface. Add pigments and fillers and continue mixing for 10 minutes. Step 2: premix the pretreated pigments and fillers in step 1 with water, dispersant, 50% defoamer, and pigment and filler wetting agent; The first stage of grinding: grinding with zirconia beads to a fineness of ≤25μm and a particle size of 1mm; Add water-based organobentonite and remaining defoamer; Second stage grinding: switch to 0.3mm zirconia beads and grind to a fineness of ≤15μm; Step 3: Transfer the ground material in step 2 to a vacuum dispersion kettle, and the vacuum degree of the vacuum dispersion kettle is ≤-0.08MPa; Slowly add water-based epoxy emulsion and pre-cool to 10°C; Maintain stirring at 5°C and add substrate wetting agent, anti-flash rust agent, and cosolvent in sequence; Vacuum stirring for 30 minutes to remove microbubbles and obtain component A; Step 4: Mix the water-based polyamide curing agent and the nano-silica aerogel, add an aqueous solution containing 0.1% cellulose thickener, and homogenize and emulsify to form a core-shell structure to obtain component B; Step 5: Stir 70% of component B and component A at low speed for 3 minutes. After standing and aging for 5 minutes, add the remaining 30% of component B and finally stir for 2 minutes to obtain the water-based epoxy anti-corrosion primer.

[0009] The beneficial effects of the present invention are as follows: 1. The salt spray resistance time of the waterborne epoxy anticorrosive primer prepared by the present invention is longer than that of the comparative example. This is because the two-component crosslinking density is higher and the anti-flash rust agent improves the initial protection. The zinc phosphate + aluminum tripolyphosphate compound has a better corrosion inhibition effect than single aluminum tripolyphosphate. In addition, the VOC in the embodiment is only 42 g / L, which is lower than the comparative example (68 g / L), which is in line with the environmental protection trend. The present invention is more convenient to apply at room temperature.

[0010] 2. The present invention forms a Si-O-Zn covalent bond on the surface of zinc phosphate through a silane coupling agent, strengthening the chemical bonding with the epoxy emulsion. The penetration path of the corrosive medium is blocked, and the mesoporous structure of the nano-aerogel adsorbs the primary amine groups of the curing agent. During gradient mixing, the curing agent is slowly released through the concentration difference, achieving the coexistence of rapid curing and long pot life. DETAILED DESCRIPTION

[0011] The present invention will be described in further detail below with reference to specific embodiments. The embodiments of the present invention are provided for purposes of illustration and description and are not intended to be exhaustive or to limit the invention to the disclosed forms. Many modifications and variations will be apparent to those skilled in the art. The embodiments are chosen and described to better illustrate the principles and practical applications of the present invention and to enable those skilled in the art to understand the present invention and design various embodiments with various modifications suitable for specific applications.

[0012] In the first embodiment, a waterborne epoxy anticorrosive primer comprises the following raw materials in parts by weight: Component A: 20 parts water, 2 parts dispersant, 15 parts titanium dioxide / 15 parts precipitated barium sulfate, 5 parts zinc phosphate, 0.5 parts defoamer, 0.5 parts wetting agent, 1 part bentonite, 35 parts water-based epoxy emulsion, 0.8 parts substrate wetting agent, 0.6 parts PNB, 1 part flash rust inhibitor, 0.5 parts silane coupling agent; Component B: 23 parts of water-based polyamide curing agent, 75 parts of water, and 2 parts of nano-silica aerogel; Component A: component B = 8:1; Step 1: Add the anti-rust pigment and silane coupling agent into a high-speed mixer and dry mix them at 80°C for 15 minutes to allow the silane to coat the pigment surface. Add pigments and fillers and continue mixing for 10 minutes. Step 2: premix the pretreated pigments and fillers in step 1 with water, dispersant, 50% defoamer, and pigment and filler wetting agent; The first stage of grinding: grinding with zirconia beads to a fineness of ≤25μm and a particle size of 1mm; Add water-based organobentonite and remaining defoamer; Second stage grinding: switch to 0.3mm zirconia beads and grind to a fineness of ≤15μm; Step 3: Transfer the ground material in step 2 to a vacuum dispersion kettle, and the vacuum degree of the vacuum dispersion kettle is ≤-0.08MPa; Slowly add water-based epoxy emulsion and pre-cool to 10°C; Maintain stirring at 5°C and add substrate wetting agent, anti-flash rust agent, and cosolvent in sequence; Vacuum stirring for 30 minutes to remove microbubbles and obtain component A; Step 4: Mix the water-based polyamide curing agent and the nano-silica aerogel, add an aqueous solution containing 0.1% cellulose thickener, and homogenize and emulsify to form a core-shell structure to obtain component B; Step 5: Stir 70% of component B and component A at low speed for 3 minutes. After standing and aging for 5 minutes, add the remaining 30% of component B and finally stir for 2 minutes to obtain the water-based epoxy anti-corrosion primer.

[0013] Example 2: A water-based epoxy anti-corrosion primer comprises the following raw materials in parts by weight: Component A: 20 parts water, 2 parts dispersant, 15 parts titanium dioxide / 15 parts precipitated barium sulfate, 2 parts zinc phosphate, 3 parts aluminum tripolyphosphate, 0.5 parts defoamer, 0.5 parts wetting agent, 1 part bentonite, 35 parts water-based epoxy emulsion, 0.8 parts substrate wetting agent, 0.6 parts PNB, 1 part flash rust inhibitor, 0.5 parts silane coupling agent; Component B: 23 parts of water-based polyamide curing agent, 75 parts of water, and 2 parts of nano-silica aerogel; Component A: component B = 10:1; Step 1: Add the anti-rust pigment and silane coupling agent into a high-speed mixer and dry mix them at 80°C for 15 minutes to allow the silane to coat the pigment surface. Add pigments and fillers and continue mixing for 10 minutes. Step 2: premix the pretreated pigments and fillers in step 1 with water, dispersant, 50% defoamer, and pigment and filler wetting agent; The first stage of grinding: grinding with zirconia beads to a fineness of ≤25μm and a particle size of 1mm; Add water-based organobentonite and remaining defoamer; Second stage grinding: switch to 0.3mm zirconia beads and grind to a fineness of ≤15μm; Step 3: Transfer the ground material in step 2 to a vacuum dispersion kettle, and the vacuum degree of the vacuum dispersion kettle is ≤-0.08MPa; Slowly add water-based epoxy emulsion and pre-cool to 10°C; Maintain stirring at 5°C and add substrate wetting agent, anti-flash rust agent, and cosolvent in sequence; Vacuum stirring for 30 minutes to remove microbubbles and obtain component A; Step 4: Mix the water-based polyamide curing agent and the nano-silica aerogel, add an aqueous solution containing 0.1% cellulose thickener, and homogenize and emulsify to form a core-shell structure to obtain component B; Step 5: Stir 70% of component B and component A at low speed for 3 minutes. After standing and aging for 5 minutes, add the remaining 30% of component B and finally stir for 2 minutes to obtain the water-based epoxy anti-corrosion primer.

[0014] Example 3: A waterborne epoxy anticorrosive primer comprises the following raw materials in parts by weight: Component A: 5 parts water, 3 parts dispersant, 40 parts titanium dioxide, 8 parts zinc phosphate, 1 part defoamer, 0.1 part wetting agent, 0.5 part bentonite, 40 parts water-based epoxy emulsion, 1 part substrate wetting agent, 0.2 parts PNB, 2 parts flash rust inhibitor, 0.5 parts silane coupling agent; Component B: 38 parts of water-based polyamide curing agent, 60 parts of water, and 2 parts of nano-silica aerogel; Component A: component B = 6:1; Step 1: Add the anti-rust pigment and silane coupling agent into a high-speed mixer and dry mix them at 80°C for 15 minutes to allow the silane to coat the pigment surface. Add pigments and fillers and continue mixing for 10 minutes. Step 2: premix the pretreated pigments and fillers in step 1 with water, dispersant, 50% defoamer, and pigment and filler wetting agent; The first stage of grinding: grinding with zirconia beads to a fineness of ≤25μm and a particle size of 1mm; Add water-based organobentonite and remaining defoamer; Second stage grinding: switch to 0.3mm zirconia beads and grind to a fineness of ≤15μm; Step 3: Transfer the ground material in step 2 to a vacuum dispersion kettle, and the vacuum degree of the vacuum dispersion kettle is ≤-0.08MPa; Slowly add water-based epoxy emulsion and pre-cool to 10°C; Maintain stirring at 5°C and add substrate wetting agent, anti-flash rust agent, and cosolvent in sequence; Vacuum stirring for 30 minutes to remove microbubbles and obtain component A; Step 4: Mix the water-based polyamide curing agent and the nano-silica aerogel, add an aqueous solution containing 0.1% cellulose thickener, and homogenize and emulsify to form a core-shell structure to obtain component B; Step 5: Stir 70% of component B and component A at low speed for 3 minutes. After standing and aging for 5 minutes, add the remaining 30% of component B and finally stir for 2 minutes to obtain the water-based epoxy anti-corrosion primer.

[0015] Example 4: A water-based epoxy anticorrosive primer comprises the following raw materials in parts by weight: Component A: 25 parts water, 1 part dispersant, 30 parts yellow iron oxide, 1 part aluminum tripolyphosphate, 0.1 part defoamer, 1 part wetting agent, 2 parts bentonite, 30 parts water-based epoxy emulsion, 0.5 part substrate wetting agent, 1 part PNB, 0.5 part flash rust inhibitor, 0.5 part silane coupling agent; Component B: 8 parts of water-based polyamide curing agent, 90 parts of water, and 2 parts of nano-silica aerogel; Component A: component B = 12:1; Step 1: Add the anti-rust pigment and silane coupling agent into a high-speed mixer and dry mix them at 80°C for 15 minutes to allow the silane to coat the pigment surface. Add pigments and fillers and continue mixing for 10 minutes. Step 2: premix the pretreated pigments and fillers in step 1 with water, dispersant, 50% defoamer, and pigment and filler wetting agent; The first stage of grinding: grinding with zirconia beads to a fineness of ≤25μm and a particle size of 1mm; Add water-based organobentonite and remaining defoamer; Second stage grinding: switch to 0.3mm zirconia beads and grind to a fineness of ≤15μm; Step 3: Transfer the ground material in step 2 to a vacuum dispersion kettle, and the vacuum degree of the vacuum dispersion kettle is ≤-0.08MPa; Slowly add water-based epoxy emulsion and pre-cool to 10°C; Maintain stirring at 5°C and add substrate wetting agent, anti-flash rust agent, and cosolvent in sequence; Vacuum stirring for 30 minutes to remove microbubbles and obtain component A; Step 4: Mix the water-based polyamide curing agent and the nano-silica aerogel, add an aqueous solution containing 0.1% cellulose thickener, and homogenize and emulsify to form a core-shell structure to obtain component B; Step 5: Stir 70% of component B and component A at low speed for 3 minutes. After standing and aging for 5 minutes, add the remaining 30% of component B and finally stir for 2 minutes to obtain the water-based epoxy anti-corrosion primer.

[0016] Comparative Example: The water-based epoxy anticorrosive primer includes the following raw materials in parts by weight: 20 parts of E-51 epoxy resin, 15 parts of composite iron titanium powder, 10 parts of silicon carbide, 25 parts of aluminum tripolyphosphate, 15 parts of red iron oxide, 20 parts of talc, 5 parts of mica powder, 25 parts of deionized water, 5 parts of butyl acrylate, 15 parts of diethylenetriamine, and 1.8 parts of corrosion inhibitor.

[0017] The above-mentioned corrosion inhibitors and additives are dispersed, and then the pigments and fillers are ground. The epoxy resin is emulsified at a high temperature of 130 degrees Celsius, and then a curing agent is added and mixed to obtain a primer.

[0018] Basic physical property tests were conducted on Examples 1 to 4 and the comparative example. The results are shown in the following table: The anti-corrosion performance test was carried out on Examples 1 to 4 and the comparative example. The results are shown in the following table: The construction and environmental protection tests were carried out on Examples 1 to 4 and the comparative example, and the results are shown in the following table: From the above performance tests, it can be seen that Example 1 (A:B=8:1) has a salt spray resistance time of 320 hours, which is significantly higher than that of the comparative example (260 hours). This is because the two-component cross-linking density is higher and the anti-flash rust agent improves the initial protection.

[0019] The corrosion inhibition effect of the zinc phosphate + aluminum tripolyphosphate compound (Example 2) is better than that of the single aluminum tripolyphosphate (Comparative Example).

[0020] When A:B=8:1, the comprehensive performance is the best (salt spray resistance 320h, impact resistance 50cm); when A:B=10:1, insufficient curing leads to decreased performance.

[0021] The VOC in Example 1 is only 42 g / L, which is lower than that in the comparative example (68 g / L), and is in line with the trend of environmental protection.

[0022] The comparative example requires emulsification at a high temperature of 130° C., which consumes a lot of energy and easily causes the curing agent to react prematurely. The example is more convenient to construct at room temperature.

[0023] The comparative example has poor solvent resistance (swelling in xylene) due to the presence of butyl acrylate; the cross-linked structure of the example is more stable.

[0024] Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field and related fields without making creative efforts should fall within the scope of protection of the present invention. Structures, devices, and operating methods not specifically described and explained in the present invention shall be implemented in accordance with conventional means in the field unless otherwise specified or limited.

Claims

1. A waterborne epoxy anticorrosive primer, characterized by: It consists of two components, A and B; Component A is prepared from the following raw materials in parts by weight: 5-25 parts of water, 1-3 parts of dispersant, 30-40 parts of pigments and fillers, 1-8 parts of anti-rust pigments, 0.1-1 parts of defoaming agent, 0.1-1 parts of pigment and filler wetting agent, 0.5-2 parts of water-based organic bentonite, 30-40 parts of water-based epoxy emulsion, 0.5-1 parts of substrate wetting agent, 0.2-1 parts of cosolvent, 0.5-2 parts of anti-flash rust agent and 0-0.5 parts of silane coupling agent; Component B is prepared from the following raw materials in parts by weight: 10-40 parts of water-based polyamide epoxy curing agent, 0-2 parts of nano-silica aerogel and 60-90 parts of water; The mass ratio of component A to component B is 6-12:

1.

2. The waterborne epoxy anticorrosive primer according to claim 1, characterized in that: The pigments and fillers are titanium dioxide, red iron oxide, yellow iron oxide, precipitated barium sulfate, talcum powder, wollastonite powder or mica powder.

3. The waterborne epoxy anticorrosive primer according to claim 1, characterized in that: The anti-rust pigment is a mixture of one or more of zinc phosphate and aluminum tripolyphosphate.

4. The waterborne epoxy anticorrosive primer according to claim 1, characterized in that: The defoaming agent is organic silicon mineral oil.

5. The waterborne epoxy anticorrosive primer according to claim 1, characterized in that: The cosolvent is PNB or DPNB.

6. The waterborne epoxy anticorrosive primer according to claim 1, characterized in that: The silane coupling agent is KH-560.

7. A method for preparing a waterborne epoxy anticorrosive primer, characterized in that: The following steps are involved: Step 1: Add the anti-rust pigment and silane coupling agent into a high-speed mixer and dry mix them at 80°C for 15 minutes to allow the silane to coat the pigment surface. Add pigments and fillers and continue mixing for 10 minutes. Step 2: premix the pretreated pigments and fillers in step 1 with water, dispersant, 50% defoamer, and pigment and filler wetting agent; The first stage of grinding: grinding with zirconia beads to a fineness of ≤25μm and a particle size of 1mm; Add water-based organobentonite and remaining defoamer; Second stage grinding: switch to 0.3mm zirconia beads and grind to a fineness of ≤15μm; Step 3: Transfer the ground material in step 2 to a vacuum dispersion kettle, and the vacuum degree of the vacuum dispersion kettle is ≤-0.08MPa; Slowly add water-based epoxy emulsion and pre-cool to 10°C; Maintain stirring at 5°C and add substrate wetting agent, anti-flash rust agent, and cosolvent in sequence; Vacuum stirring for 30 minutes to remove microbubbles and obtain component A; Step 4: Mix the water-based polyamide curing agent and the nano-silica aerogel, add an aqueous solution containing 0.1% cellulose thickener, and homogenize and emulsify to form a core-shell structure to obtain component B; Step 5: Stir 70% of component B and component A at low speed for 3 minutes. After standing and aging for 5 minutes, add the remaining 30% of component B and finally stir for 2 minutes to obtain the water-based epoxy anti-corrosion primer.

Images