Multipurpose water-based seal primer and preparation method thereof

Abstract

The invention belongs to the technical field of water-based coatings, and particularly relates to a multipurpose water-based seal primer and a preparation method thereof.The multipurpose water-based seal primer comprises a component A and a component B. The mass ratio of the component A to the component B is 7: 1, and the component A comprises, by mass, 20-50% of water-based epoxy emulsion, 10-15% of anti-rust pigment, 3-10% of tinting pigment, 20-40% of water, 3-8% of water-based auxiliaries, 8-20% of body filler and the balance solvent; and the component B comprises the following components in percentage by mass: 20-40% of a water-based amine curing agent, 10-20% of a cosolvent, 10-40% of deionized water and 3-8% of a water-based additive. The water-based seal primer is low in solvent content, ultralow in VOC emission, excellent in paint film appearance effect, high in adhesive force and high in cracking resistance, can be used for the surfaces of various base materials, and has good matching performance and resistance, excellent base material adaptability, excellent drying speed, excellent chemical resistance, excellent corrosion resistance, excellent construction latitude and excellent constructability; and high film thickness, excellent anti-sagging property and excellent mechanical property can be coated at one time.

Description

Technical Field

[0001] The invention belongs to the technical field of water-based coatings, and in particular relates to a multi-purpose water-based sealing primer and a preparation method thereof. Background Art

[0002] As people pay more attention to environmental protection and environmental regulations become increasingly stringent, coating suppliers and users have higher and higher requirements for environmental protection and pay more and more attention to volatile organic compounds (VOC), thus requiring the solvent content in coatings to be lower and lower. The water-based sealing primer involved in the present invention has a good sealing effect mainly for various substrate surfaces such as electrogalvanizing, hot-dip galvanizing, and hot-spraying zinc, avoiding paint film defects caused by the reaction between conventional water-based primers and substrate surfaces. It provides a transition for subsequent coatings, has good wetting agent permeability, has good adhesion to substrates and subsequent topcoats, and is also suitable for use as a substrate sealing paint before applying solvent-based topcoats. Water is used as a diluent, which is non-toxic and safe.

[0003] The invention patent with Chinese patent publication number CN111961169A discloses a water-based epoxy resin emulsion, a primer and a preparation method thereof. The primer prepared in the patent has excellent water resistance, acid and alkali resistance and adhesion, is environmentally friendly, low in VOC, and is a green and environmentally friendly primer. However, it may react with the surface of substrates such as electrogalvanized, hot-dip galvanized, and hot-sprayed zinc, affecting the adhesion of subsequent topcoats. Summary of the invention

[0004] The purpose of the present invention is to mainly solve the problem that the water-based sealing primer currently on the market has no good sealing effect on the surfaces of substrates such as electrogalvanized, hot-dip galvanized, and hot-sprayed zinc, and conventional water-based primers react with the surfaces of the substrates.

[0005] In order to solve the above problems, the present invention provides a multi-purpose water-based sealing primer and a preparation method thereof. The specific technical scheme of the present invention is as follows: The multi-purpose water-based sealing primer provided by the present invention is characterized in that it comprises two components, A and B, wherein the mass ratio of component A to component B is 7:1, component A is a main component of a multi-purpose water-based sealing primer, and the component A comprises, by mass percentage, 20-50% of water-based epoxy emulsion, 10-15% of anti-rust pigment, 3-10% of coloring pigment, 8-20% of body filler, 3-8% of water-based auxiliary agent, 20-40% of deionized water, and the remainder of solvent; the component B is a curing agent part of a multi-purpose water-based sealing primer, and the component B comprises, by mass percentage, 20-40% of water-based amine curing agent, 10-20% of cosolvent, 20-40% of deionized water, and 3-8% of water-based auxiliary agent; wherein the water-based epoxy emulsion is preferably E11, E13 produced by Xingfeng Chemical Company or COATECH™ WE 7675 produced by Gaotai Company, and the water-based amine curing agent is preferably Q14, Q15 produced by Xingfeng Chemical Company or Coatech™ WE 7372-80.

[0006] Preferably, the coloring pigment is a mixture of carbon black, titanium dioxide and barium sulfate, with the weight percentage of carbon black being 0.5-1%, the weight percentage of titanium dioxide being 3-5%, and the weight percentage of barium sulfate being 5-10%; the carbon black is preferably MA-100 produced by Mitsubishi Corporation of Japan, and the titanium dioxide is preferably R996 produced by Lomon Billions Corporation.

[0007] Preferably, the aqueous additive comprises, by weight percentage: 0.5-1% aqueous dispersant, 0.3-0.7% aqueous defoamer, 0.3-0.5% aqueous wetting agent, 1-2% aqueous thickener, 0.3-0.6% pH adjuster, and 3-8% aqueous metal passivator.

[0008] Preferably, the aqueous defoamer comprises at least two different aqueous defoamers, and the aqueous defoamers include, by weight percentage: 0.1-0.3% silicone defoamer and 0.2-0.4% mineral oil defoamer; wherein the silicone defoamer is preferably Airex 902w produced by Evonik Specialty Chemicals or Coadd DF-002 produced by Puwei New Materials Technology Co., Ltd., and the mineral oil defoamer is preferably BASF Foamaster 2190 or CoaddDF-420 produced by Puwei New Materials Technology Co., Ltd.

[0009] Preferably, the aqueous thickener comprises at least two different aqueous thickeners, and the aqueous thickener comprises, by weight percentage: 0.5-1% polyurethane thickener and 0.05-0.1% aqueous bentonite; wherein the polyurethane thickener is preferably RM-12w produced by Dow Chemical Company or Coadd U-112 associative polyurethane thickener produced by Puwei New Materials Technology Co., Ltd., and the aqueous bentonite is preferably DW produced by Hemmings Company.

[0010] Preferably, the aqueous dispersant is a non-ionic high molecular weight polymer aqueous dispersant having a comb-like structure and providing excellent stability and color development, preferably CAP-221 produced by Xingfeng Chemical Company or Coadd D-74 produced by Puwei New Material Technology Co., Ltd.

[0011] Preferably, the aqueous wetting agent is a low-foaming, high-efficiency silicone aqueous wetting agent, preferably TEGO WET 270 produced by Evonik Specialty Chemicals or Coadd W-118 produced by Puwei New Material Technology Co., Ltd.

[0012] Preferably, the pH adjuster is AMP-95.

[0013] Preferably, the water-based passivating agent is a metal passivating agent with excellent stability, which reduces the probability of active metals reacting with water by forming a protective oxide film on the metal surface, and has a highly efficient passivating effect on the metal substrate. The water-based metal passivating agent is 3-8% by weight, and Coadd™ MP-86 from Puwei New Material Technology Co., Ltd. is preferred.

[0014] Preferably, the solvent comprises, by weight percentage: 1-3% diethylene glycol butyl ether and 1-3% ethylene glycol butyl ether.

[0015] The present invention also provides a method for preparing a multi-purpose water-based sealing primer, wherein the preparation of component A comprises the following steps: S1. Deionized water, dispersant and defoamer are sequentially added to a stirring container and dispersed at 500-800 rpm for 5-10 minutes, and then anti-rust pigment, coloring pigment and body filler are sequentially added and dispersed at 1000-1500 rpm for 15 minutes; S2. Add zirconium beads and disperse at high speed at 2000-2500 rpm. After the fineness reaches less than 20 microns, filter and pour into the paint mixing tank; S3. In a paint mixing tank, the aqueous epoxy emulsion, solvent, defoamer, wetting agent, passivator, anti-flash rust agent, thickener are sequentially added to the paint mixing tank and dispersed for 10-15 minutes under stirring conditions of 500-800 rpm to prepare component A; The preparation of component B includes the following steps: Add deionized water, co-solvent and amine curing agent to a clean paint mixing tank in sequence, control the feeding time within 30 minutes, and stir for 15 minutes to prepare component B; Compared with the water-based sealing primer of the prior art, the water-based sealing primer provided by the present invention, which can be used for a variety of substrates and has good matching and resistance, has a low solvent content, and therefore has ultra-low VOC emissions, excellent paint film appearance, strong adhesion (reaching level 0), and strong crack resistance (crack film thickness reaches 75-80μm). In addition, the water-based sealing primer that can be used for various substrate surfaces such as electrogalvanizing, hot-dip galvanizing, and hot-spraying zinc has good matching and resistance and also has excellent substrate adaptability, excellent drying speed and chemical resistance, excellent anti-corrosion performance, excellent construction tolerance and construction performance, can be applied at a high film thickness at one time, excellent anti-sagging, and excellent mechanical properties. The water-based sealing primer can be widely used in wind power, steel structure, auto parts and other fields. DETAILED DESCRIPTION

[0016] In order to make the purpose and principle of the present invention more clear, it is further described below in conjunction with specific embodiments.

[0017] The waterborne epoxy emulsion in the present invention is selected from E11, E13 produced by Xingfeng Chemical Company or COATECH™ WE 7675 produced by Gaotai Company, and the waterborne amine curing agent is selected from Q14, Q15 of Xingfeng Chemical Company or Coatech™ WE 7372-80 produced by Gaotai Company.

[0018] The preferred carbon black for the coloring pigment is MA-100 produced by Mitsubishi Corporation of Japan, and the titanium dioxide is R996 produced by Longman Billions. The silicone defoamer is Airex 901w produced by Evonik Specialty Chemicals or Coadd DF-002 produced by Puwei New Material Technology Co., Ltd.

[0019] The defoaming agent is preferably an organosilicon defoaming agent such as Airex 902w produced by Evonik Specialty Chemicals or Coadd DF-002 produced by Puwei New Material Technology Co., Ltd., and the mineral oil defoaming agent is BASF Foamaster 2190 or Coadd DF-420 produced by Puwei New Material Technology Co., Ltd.

[0020] The thickener is preferably a polyurethane thickener such as RM-12w produced by Dow Chemical Company or Coadd U-112 associative polyurethane thickener produced by Puwei New Material Technology Co., Ltd., and the water-based bentonite is DW produced by Hemmings Company.

[0021] The dispersant is CAP-221 produced by Xingfeng Chemical Company or Coadd D-74 produced by Puwei New Material Technology Co., Ltd.

[0022] The wetting agent is TEGO WET 270 produced by Evonik Specialty Chemicals or Coadd W-118 produced by Puwei New Material Technology Co., Ltd.

[0023] The pH adjuster was AMP-95.

[0024] The metal passivator is Coadd™ MP-86 from Puwei New Material Technology Co., Ltd.

[0025] <Example 1> This embodiment provides a multi-purpose water-based sealing primer component A, and its formula is listed in Table 1.

[0026] Table 1 This embodiment also provides a method for preparing the multi-purpose water-based sealing primer. The method is prepared according to the formula ratio in Table 1, and comprises the following steps: Step S1, adding water, aqueous dispersant, defoamer, and pH adjuster into a stirring container in sequence, dispersing them at 500-800 rpm / min for 5-10 min, and then adding pigments and fillers and dispersing them at high speed at 1000-1500 rpm / min for 15 min; Step S2, adding zirconium beads, dispersing at high speed at 2000-2500 rpm / min, filtering after the fineness reaches less than 15 μm, and pouring the filtrate into a paint mixing tank; Step S3, in a paint mixing tank, respectively, adding water-based epoxy emulsion, solvent, defoamer, water-based wetting agent, water-based thickener, and water-based metal passivator into the paint mixing tank in sequence and dispersing them for 10-15 minutes under stirring conditions of 500-800 rpm / min, thereby obtaining a water-based sealing primer with good matching and resistance that can be used for a variety of substrates.

[0027] A multi-purpose water-based sealing primer component B, the formula of which is listed in Table 2.

[0028] Table 2 This embodiment also provides a method for preparing the multi-purpose water-based sealing primer. The method is prepared according to the formula ratio in Table 2, and comprises the following steps: Add amine curing agent, deionized water, drying agent, solvent and anti-flash rust agent in a clean paint mixing tank in sequence, and control the feeding time within 30 minutes. Stir for 15 minutes to prepare component B; <Example 2> This embodiment provides another multi-purpose water-based sealing primer main agent, and its formula is listed in Table 3.

[0029] Table 3 The preparation method of the multi-purpose water-based sealing primer of this embodiment is prepared according to the formula ratio of Table 2, and the preparation steps are consistent with the preparation steps of Example 1.

[0030] A multi-purpose water-based sealing primer component B, the formula of which is listed in Table 2.

[0031] <Example 3> This embodiment provides another multi-purpose water-based sealing primer, and its formula is listed in Table 4.

[0032] Table 4 The preparation method of the multi-purpose water-based sealing primer of this embodiment is prepared according to the formula ratio of Table 3, and the preparation steps are consistent with the preparation steps of Example 1.

[0033] A multi-purpose water-based sealing primer component B, the formula of which is listed in Table 5.

[0034] Table 5 Components raw material Weight percentage / % Waterborne amine curing agent Coatech™ WE 7372-80 42 Deionized water -- 34 Drier K54 3.5 Ethylene glycol butyl ether -- 20 Anti-flash rust agent TEGO WET 270 from Evonik Specialty Chemicals 0.5 <Test example> In this test example, the multi-purpose water-based sealing primer prepared in the above embodiment and the control group (Hempel) were coated on the same substrate surface according to the same method, and various performance tests were performed on the coating. The test results are listed in Table 6.

[0035] Among them, the test substrates for the bending test, cupping test, and impact test are all tinplate plates with a dry film thickness of 40-60μm. The substrates used for other performance test items are all sandblasted steel plates with a dry film thickness of 40-60μm.

[0036] Table 6 Test items Detection Methods Control group Example 1 Example 2 Example 3 Coating hardness GB / T 6739-2006 H H H H Coating bending test GB / T 11185-2009 2mm 2mm 2mm 1mm Coating impact resistance GB / T 1732-1993 50 50 50 50 Coating Adhesion GB / T 9286 Level 4 Level 0 Level 0 Level 0 Coating water resistance (40℃) GB / T 5209-1985 120h 240h 240h 240h Alkali resistance of coating (0.1N NaOH, 4h) GB / T 9274 pass pass pass pass <![CDATA[Acid resistance of coating (0.1N H2SO4, 24h)]]> GB / T 9274 pass pass pass pass Coating salt spray resistance (500h) GB / T1771 Foaming pass pass pass VOC GB / T24409 188 98 89 82 Electrogalvanizing compatibility / Foaming pass pass pass Hot dip galvanizing compatibility / Foaming pass pass pass Hot-spray zinc matching / Foaming pass pass pass As shown in Table 6, compared with the water-based sealing primer in the prior art, the multi-purpose water-based sealing primer prepared in the above embodiment has better performance in terms of compatibility with various metal substrates, salt spray resistance, coating adhesion, etc. Moreover, the multi-purpose water-based sealing primer has a low solvent content, ultra-low VOC emissions, and excellent mechanical properties, chemical resistance, anti-corrosion performance, and construction performance.

[0037] The above description is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent substitutions or changes according to the technical solutions and novel concepts of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A multi-purpose water-based sealing primer, characterized in that: It includes two components, A and B, the mass ratio of component A to component B is 7:1, and the component A includes, by mass percentage: Water-based epoxy emulsion 20-50%; Anti-rust pigment 10-15%; Coloring pigment 3-10%; Water 20-40%; Water-based additives 3-8%; Physical filler 8-20%; Solvent residue; The B component comprises, by mass percentage: Water-based amine curing agent 20-40%; Solvent 10-20%; Deionized water 10-40%; Water-based additives 3-8%.

2. A multi-purpose water-based sealing primer as claimed in claim 1, characterized in that: The coloring pigment is a mixture of carbon black, titanium dioxide and barium sulfate, wherein the weight percentage of carbon black is 0.5-1%, the weight percentage of titanium dioxide is 3-5%, and the weight percentage of barium sulfate is 5-10%.

3. A multi-purpose water-based sealing primer as claimed in claim 1, characterized in that: The aqueous additive comprises by weight percentage: Aqueous dispersant 0.5-1%; Water-based defoamer 0.3-0.7%; Aqueous wetting agent 0.3-0.5%; Water-based thickener 1-2%; pH adjuster 0.3-0.6%; Water-based metal passivator 3-8%.

4. A multi-purpose water-based sealing primer as claimed in claim 1, characterized in that: The aqueous defoamer comprises at least two different aqueous defoamers, and the aqueous defoamers include, by weight percentage: 0.1-0.3% of an organosilicon defoamer and 0.2-0.4% of a mineral oil defoamer.

5. A multi-purpose water-based sealing primer as claimed in claim 1, characterized in that: The aqueous thickener comprises at least two different aqueous thickeners, and the aqueous thickeners include, by weight percentage: 0.5-1% polyurethane thickener and 0.05-0.1% aqueous bentonite.

6. A multi-purpose water-based sealing primer as claimed in claim 1, characterized in that: The water-based metal passivator forms a protective oxide film on the metal surface to reduce the probability of active metals reacting with water. The water-based metal passivator is 3-8% by weight.

7. A multi-purpose water-based sealing primer as claimed in claim 1, characterized in that: The aqueous dispersant is a non-ionic high molecular weight polymer aqueous dispersant with a comb-shaped structure; the aqueous wetting agent is a low-foaming and high-efficiency organic silicon aqueous wetting agent; and the pH regulator is a multifunctional amine auxiliary agent.

8. A multi-purpose water-based sealing primer as claimed in claim 1, characterized in that: The solvent comprises, by weight percentage, 1-3% of diethylene glycol butyl ether and 1-3% of ethylene glycol butyl ether.

9. A method for preparing the multi-purpose water-based sealing primer as claimed in claim 1, characterized in that: The preparation of component A includes the following steps: S1. Deionized water, dispersant and defoamer are sequentially added to a stirring container and dispersed at 500-800 rpm for 5-10 minutes, and then anti-rust pigment, coloring pigment and body filler are sequentially added and dispersed at 1000-1500 rpm for 15 minutes; S2. Add zirconium beads and disperse at high speed at 2000-2500 rpm. After the fineness reaches less than 20 microns, filter and pour into the paint mixing tank; S3. In the paint mixing tank, the aqueous epoxy emulsion, solvent, defoamer, wetting agent, passivator, anti-flash rust agent, thickener were sequentially added to the paint mixing tank and dispersed for 10-15 minutes at 500-800 rpm to prepare component A; The preparation of component B includes the following steps: Add deionized water, co-solvent and amine curing agent to a clean paint mixing tank in sequence, control the feeding time within 30 minutes, and stir for 15 minutes.

Images