Water-based bi-component epoxy primer for public buses and preparation method of water-based bi-component epoxy primer

Abstract

The invention relates to the technical field of epoxy primer, and discloses a water-based bi-component epoxy primer for public buses, which comprises the following raw materials in parts by mass: a component A: 38-43 parts of water-based epoxy resin; 15-20 parts of an anti-rust and anti-corrosion pigment; 10 to 15 parts of a pigment filling agent; 10 to 15 parts of body filler; 2.5 to 3.0 parts of a cosolvent; 2.5 to 3.0 parts of a dispersant; 0.3 to 0.5 part of a defoaming agent; 0.5 to 1 part of a wetting leveling agent; 0.5 to 1 part of a flash rust inhibitor; 0.2 to 0.5 part of a rheological additive; 10 to 15 parts of deionized water; a component B: 15-30 parts of an epoxy curing agent; and 10 to 20 parts of deionized water. The water-borne epoxy resin is a mixed solution of two emulsions with different particle sizes, and the anti-rust pigment is a mixed pigment of aluminum tripolyphosphate and composite zinc phosphate. The water-based bi-component epoxy primer for the public bus is high in adhesive force, good in flexibility, excellent in impact resistance and excellent in salt mist resistance and chemical resistance.

Description

Technical Field

[0001] The invention relates to the technical field of epoxy primers, and in particular to a water-based two-component epoxy primer for public buses and a preparation method thereof. Background Art

[0004] There are also some two-component epoxy primers in the prior art, such as the Chinese invention patent with application number 201610294687.3, entitled "A water-based two-component epoxy primer for automobiles with excellent performance and its preparation method", which includes component A and component B, and specifically discloses its composition and preparation method. It can be used as an automobile coating. It not only has a low VOC content and is an environmentally friendly product, but also has excellent adhesion, filling, and polishing properties, excellent physical and mechanical properties, water resistance and chemical resistance, excellent low-viscosity anti-settling properties, workability and anti-sagging properties, excellent hiding power, storage stability and drying speed.

[0005] (2) Another example is the Chinese authorized invention patent with application number 201910035133.5, entitled "Water-based two-component epoxy anticorrosive primer for water-based and solvent-based coatings", which discloses the preparation methods of components A and B. It has excellent adhesion to substrates such as steel plates and aluminum plates, high hardness, and not only has excellent anticorrosive performance in water-based coatings, but also makes up for the limited application range of general water-based anticorrosive coatings. It can be used as a primer for both water-based and solvent-based coatings, has a wide range of applications, and is energy-saving and environmentally friendly. Summary of the invention

[0006] In order to overcome the deficiencies of the prior art, the object of the present invention is to provide a water-based two-component epoxy primer for public buses and a preparation method thereof, which has strong adhesion, good flexibility, excellent impact resistance, and excellent salt spray resistance and chemical resistance.

[0007] The present invention is implemented by the following technical scheme: A water-based two-component epoxy primer for a public bus comprises the following raw materials in parts by weight:

[0008] Component A:

[0009] Waterborne epoxy resin: 38-43 parts;

[0010] Anti-rust and anti-corrosion pigments: 15-20 parts;

[0011] Pigment filler: 10-15 parts;

[0012] Physical filler: 10-15 parts;

[0013] Solvent: 2.5-3.0 parts;

[0014] Dispersant: 2.5-3.0 parts;

[0015] Defoaming agent: 0.3-0.5 parts;

[0016] Wetting and leveling agent: 0.5-1 part;

[0017] Anti-flash rust agent: 0.5-1 part;

[0018] Rheological additive: 0.2-0.5 parts;

[0019] Deionized water: 10-15 parts;

[0020] Component B:

[0021] Epoxy curing agent: 15 to 30 parts;

[0022] Deionized water: 10-20 parts.

[0023] Furthermore, the water-based epoxy resin is a mixture of two emulsions with different particle sizes: water-based epoxy resin EP384W / 53W and water-based epoxy resin EP387W / 54W.

[0024] Furthermore, the anti-rust and anti-rust pigment is a mixed pigment of aluminum tripolyphosphate and composite zinc phosphate.

[0025] Furthermore, the pigment filler is a mixed filler of a 1500-mesh barium sulfate pigment filler and a 1250-mesh talc filler.

[0026] Furthermore, the physical filler is R-996 titanium dioxide.

[0027] Furthermore, the co-solvent is dipropylene glycol methyl ether.

[0028] Furthermore, the dispersant is BYK-190 dispersant or BYK-194 dispersant.

[0029] Furthermore, the defoamer is a mixed defoamer of BYK-028 defoamer and 902W defoamer; the wetting and leveling agent is XL-401 leveling agent; the anti-flash rust additive is ED-617F anti-flash rust additive; and the rheological additive is 0620 rheological additive.

[0030] A method for preparing a water-based two-component epoxy primer for a bus, using the water-based two-component epoxy primer for a bus, comprising the following steps:

[0031] First, a grinding slurry is prepared, and then a finished paint is prepared using the grinding slurry, and preferably the finished paint is mixed with component B to prepare a primer;

[0032] The preparation steps of the grinding slurry are:

[0033] Step a1, add deionized water and co-solvent in sequence to start dispersion; then add dispersant and defoamer in sequence, and stir for 10 minutes after all are added;

[0034] Step b1, according to the raw material ratio, add anti-rust and anti-corrosion pigment, pigment filler, and physical filler in sequence, adjust the speed to 1000-1200rpm after all are added, and disperse at high speed for 20 minutes;

[0035] Step c1, select a suitable grinder, adjust the grinding parameters, and control the fineness of the grinding slurry to ≤25 μm;

[0036] The preparation steps of the finished paint are:

[0037] Step a2, transferring the pre-prepared grinding slurry to a suitable production equipment;

[0038] Step b2, rotating speed 500-700 rpm, add water-based epoxy resin, anti-rust agent, wetting and leveling agent in sequence, after all are added, stir for 10 minutes;

[0039] Step c2, rotating speed 600-800 rpm, adding rheological additive to adjust the viscosity of the paint slurry to the design index range, and preparing a finished paint;

[0040] The preparation steps of the primer are:

[0041] The epoxy curing agent is added to deionized water for dilution, and then added to the finished paint for mixing to prepare a two-component epoxy primer.

[0042] Compared with the prior art, the beneficial effects of the present invention are: the water-based two-component epoxy primer for public buses of the present invention has the characteristics of strong adhesion, good flexibility, excellent impact resistance, etc. on a variety of substrates (galvanized sheet, fiberglass, cold-rolled sheet, aluminum alloy), excellent salt spray resistance and chemical resistance, and some performances are greatly improved compared with the epoxy primer in the prior art. DETAILED DESCRIPTION

[0043] The following describes the embodiments of the present invention by specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the following embodiments and features in the embodiments can be combined with each other without conflict.

[0044] The object of the present invention is to provide a highly anti-corrosion sulfonated polyaniline modified waterborne epoxy resin coating and a preparation method thereof in view of the defects of the prior art.

[0045] Embodiment 1

[0046] The invention provides a water-based two-component epoxy primer for public buses, comprising the following raw materials in parts by weight: component A: 38 to 43 parts of water-based epoxy resin; 15 to 20 parts of anti-rust and anti-corrosion pigments; 10 to 15 parts of pigment fillers; 10 to 15 parts of physical fillers; 2.5 to 3.0 parts of cosolvents; 2.5 to 3.0 parts of dispersants; 0.3 to 0.5 parts of defoamers; 0.5 to 1 parts of wetting and leveling agents; 0.5 to 1 parts of anti-flash rust agents; 0.2 to 0.5 parts of rheological additives; 10 to 15 parts of deionized water; component B: 15 to 30 parts of epoxy curing agents; and 10 to 20 parts of deionized water.

[0047] Specifically, the raw material composition of a water-based two-component epoxy primer for a bus in this embodiment is shown in Table 1 in parts by weight.

[0048] Table 1 Raw material composition of water-based two-component epoxy primer for public buses

[0049]

[0050] Preferably, the water-based epoxy resin is a mixture of two emulsions with different particle sizes, namely, water-based epoxy resin EP384W / 53W and water-based epoxy resin EP387W / 54W of Zhenxin. In this embodiment, the mass ratio is 1:1. Of course, different ratios can be adjusted according to needs. The two water-based epoxy resin emulsions have different particle sizes and are used in combination with each other, which can not only ensure the adhesion of the paint film to the substrate, but also have good paint film toughness.

[0051] Preferably, the antirust and anticorrosion pigment is aluminum tripolyphosphate and composite zinc phosphate mixed pigment of Shijiazhuang Xinsheng Chemical, and its mass ratio is 1:1.5 in the present embodiment. Aluminum tripolyphosphate has good affinity with varnish, and tripolyphosphate root ion P30105- has good chemical activity, can form complex with various metal ions, such as iron ion, to form protective film. Zinc phosphate also has strong condensation ability with trivalent iron ion, and its root ion and iron ion can form a solid protective film with iron phosphate as the main body, and this dense passivation film is insoluble in water, has high hardness, strong adhesion, can generate chromium compound with many metal ions, and has good antirust effect.

[0052] Preferably, the pigment filler is a mixed filler of 1500 mesh barium sulfate pigment filler from Baoding Bohai and 1250 mesh talc filler from Beijing Liguo Weiye, and the mass ratio in this embodiment is 1: 1. Barium sulfate has the advantages of strong chemical inertness, good stability, acid and alkali resistance, etc., which can improve the flame retardancy and impermeability of the primer; talc as a filler can increase the stability of the primer shape, increase the tensile strength, shear strength and flexural strength, and reduce deformation, elongation, and thermal expansion coefficient.

[0053] Preferably, the physical filler is R-996 titanium dioxide from DuPont of the United States, which has stable chemical properties and has excellent pigment properties after surface aluminum coating treatment, good brightness and gloss, strong hiding power, tinting power and fluidity, and good weather resistance and anti-powdering properties.

[0054] Preferably, the co-solvent is dipropylene glycol methyl ether (DPM) from Dow Chemical of the United States.

[0055] Preferably, the dispersant is BYK-190 dispersant or BYK-194 dispersant from German BYK Chemicals. It is easily soluble in water and can be mixed with various surfactants for use. It can reduce the time and energy required for the primer to complete the dispersion process, stabilize the dispersed pigment dispersion, modify the surface properties of the pigment particles, and adjust the mobility of the pigment particles.

[0056] Preferably, the defoamer is a mixture of BYK-028 defoamer from German BYK Chemical and 902W defoamer from American Dow Chemical, and in this embodiment, the mass ratio is 1:2. It is used to absorb bubbles and enter the bubble film to thin the base after foaming in the coating processing, and can quickly destroy and suppress bubbles and lower the liquid level.

[0057] Preferably, the wetting and leveling agent is the XL-401 leveling agent of Shanghai Xuanwan Chemical Industry, which mainly functions to improve the surface properties of the coating and enhance the adhesion and glossiness of the coating.

[0058] Preferably, the anti-flash rust additive is ED-617F anti-flash rust additive produced by Shanghai Tianyu Chemical Industry; it is used to prevent corrosion caused by sodium salts, form an anodic passivation layer on the surface of the metal substrate, and effectively prevent flash rust. The coating film formed by the anti-flash rust additive can also achieve an anti-corrosion effect at the same time.

[0059] Preferably, the rheological additive is Wanhua Company's 0620 rheological additive, which is used for thickening water-based paint to facilitate the production, storage and construction of the paint.

[0060] The water-based two-component epoxy primer for public buses prepared by the present invention has the characteristics of strong adhesion, good flexibility, excellent impact resistance, etc., and has excellent salt spray resistance and chemical resistance.

[0061] Embodiment 2

[0062] A method for preparing a water-based two-component epoxy primer for a bus, using the water-based two-component epoxy primer component for a bus in Example 1 to prepare the epoxy primer, comprising the following steps:

[0063] First, the grind slurry is prepared, and then the finished paint is prepared from the grind slurry. The finished paint is preferably mixed with the B component to prepare the primer.

[0064] Specifically, the preparation steps of the grinding slurry are:

[0065] Step a1, add deionized water and co-solvent in sequence to start dispersion; then add dispersant and defoamer in sequence, and stir for 10 minutes after all are added;

[0066] Step b1, according to the raw material ratio, add anti-rust and anti-corrosion pigment, pigment filler, and physical filler in sequence, adjust the speed to 1000-1200rpm after all are added, and disperse at high speed for 20 minutes;

[0067] Step c1, select a suitable grinder, adjust the grinding parameters, and control the fineness of the grinding slurry to ≤25 μm;

[0068] Specifically, the preparation steps of the finished paint are:

[0069] Step a2, transferring the pre-prepared grinding slurry to a suitable production equipment;

[0070] Step b2, rotating speed 500-700 rpm, add water-based epoxy resin, anti-rust agent, wetting and leveling agent in sequence, after all are added, stir for 10 minutes;

[0071] Step c2, rotating speed 600-800 rpm, adding rheological additive to adjust the viscosity of the paint slurry to the design index range, and preparing a finished paint;

[0072] The preparation steps of the primer are:

[0073] The epoxy curing agent is added to deionized water for dilution, and then added to the finished paint for mixing to prepare a two-component epoxy primer.

[0074] The performance of the water-based two-component epoxy primer for buses was tested, and its various indicators are:

[0075] (1) Pencil hardness: Refer to the specification of "Determination of film hardness of paints and varnishes by pencil method" GB / T 6739-2022, and use the PPH-750 trolley pencil hardness tester of Shanghai Tianchen Modern Environmental Technology Co., Ltd. for testing. The pencil hardness is HB-H.

[0076] (2) Impact strength: refer to the "Determination of impact resistance of paint film" GB / T 1732-2020 specification, and use the QCJ paint film impact tester of Shenzhen Lai Te Instrument Equipment Co., Ltd. to test. A 1 kg weight falls freely on the coating test plate, and the maximum height at which the paint film undergoes elongation and deformation without causing damage indicates the impact resistance of the paint film, and the impact resistance is greater than 100 cm.

[0077] (3) Adhesion: Refer to the "Scratch Test for Paint and Varnish Films" GB / T 9286-2021 specification, and use the QFH paint film 100-grid knife scratch tester of Shenzhen Xingke Instrument Co., Ltd. for testing. Adhesion decreases from 0 to 5 levels, with 0 being the best, 5 being the worst, and 3 being basically qualified. The test result is adhesion level 0 (substrate aluminum alloy).

[0078] (4) Bending resistance: Referring to the GB / T 1731-2020 specification "Determination of flexibility of paint film and putty film", a QTX paint film flexibility tester is used to apply the epoxy primer on a metal plate. The plate is bent on shafts of different diameters (mm) to determine the bending resistance of the paint film and test its flexibility. The bending resistance of the epoxy primer is less than 5mm.

[0079] (5) Water resistance: Refer to the "Determination of Water Resistance of Paint Film" GB / T 1733-1993 specification, use the ZY6354 paint film water resistance tester of Dongguan Zhongnuo Quality Inspection Instrument Co., Ltd. to test, immerse the paint film sample in water in a transparent glass tank on all four sides, and observe the state of the paint film. The water resistance of epoxy primer (40℃)> 480h.

[0080] (6) Acid and alkali resistance: Tested in accordance with the "Test Standard for Waterborne Epoxy Resin Anticorrosive Coatings" HG / T 4759-2014. One end of a glass tube with an inner diameter of not less than 50m is glued to the center of the tested coating surface with vaseline. Then, a certain amount of H2SO4, HAC acid solution, or NaOH alkaline solution is poured into the glass tube as needed and kept for a certain period of time. The coated plate sample is then removed and visually inspected for bubbling, discoloration, peeling, and other abnormal phenomena. The epoxy primer is tested for acid resistance (3%, H2SO4) > 168h, alkali resistance (2%, NaOH) > 168h, and acid resistance (5%, HAC) > 168h.

[0081] (7) Neutral salt spray resistance: Refer to GB / T1771-2007 "Determination of neutral salt spray resistance of paints and varnishes", and use the BLD-YW salt spray test chamber of Kunshan Bailida Testing Equipment Co., Ltd. for testing. The neutral salt spray resistance of epoxy primer is greater than 500h.

[0082] During the research and development, first, a special film-forming main resin is selected to ensure the basic performance of the paint film; second, a curing agent that matches the main resin is selected; third, a reasonable combination of co-solvents is selected to adjust the product's construction viscosity and drying performance; fourth, high-quality functional additives are combined to adjust the product's rheological parameters; finally, through a special manufacturing process, this water-based paint product with special excellent performance is prepared.

[0083] The water-based two-component epoxy primer for public buses prepared by the present invention has the characteristics of strong adhesion, good flexibility, excellent impact resistance, etc. on a variety of substrates (galvanized sheet, fiberglass, cold-rolled sheet, aluminum alloy), excellent salt spray resistance and chemical resistance, and some performances are greatly improved compared with the epoxy primer in the prior art.

[0084] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A water-based two-component epoxy primer for buses, characterized in that: The invention comprises the following raw materials in parts by weight: Component A: Waterborne epoxy resin: 38-43 parts; Anti-rust and anti-corrosion pigments: 15-20 parts; Pigment filler: 10-15 parts; Physical filler: 10-15 parts; Solvent: 2.5-3.0 parts; Dispersant: 2.5-3.0 parts; Defoaming agent: 0.3-0.5 parts; Wetting and leveling agent: 0.5-1 part; Anti-flash rust agent: 0.5-1 part; Rheological additive: 0.2-0.5 parts; Deionized water: 10-15 parts; Component B: Epoxy curing agent: 15 to 30 parts; Deionized water: 10-20 parts.

2. The water-based two-component epoxy primer for public transportation vehicles according to claim 1, characterized in that: The water-based epoxy resin is a mixture of two emulsions with different particle sizes: water-based epoxy resin EP384W / 53W and water-based epoxy resin EP387W / 54W.

3. The water-based two-component epoxy primer for public transportation according to claim 2, characterized in that: The anti-rust and anti-rust pigment is a mixed pigment of aluminum tripolyphosphate and composite zinc phosphate.

4. The water-based two-component epoxy primer for public transportation vehicles according to claim 3, characterized in that: The pigment filler is a mixed filler of a 1500-mesh barium sulfate pigment filler and a 1250-mesh talcum powder filler.

5. The water-based two-component epoxy primer for public transportation vehicles according to claim 4, characterized in that: The physical filler is R-996 titanium dioxide.

6. The water-based two-component epoxy primer for public transportation vehicles according to claim 5, characterized in that: The cosolvent is dipropylene glycol methyl ether.

7. The water-based two-component epoxy primer for public transportation vehicles according to claim 6, characterized in that: The dispersant is BYK-190 dispersant or BYK-194 dispersant.

8. The water-based two-component epoxy primer for public transportation vehicles according to claim 7, characterized in that: The defoamer is a mixed defoamer of BYK-028 defoamer and 902W defoamer.

9. The water-based two-component epoxy primer for public transportation vehicles according to claim 8, characterized in that: The wetting and leveling agent is XL-401 leveling agent; the anti-flash rust additive is ED-617F anti-flash rust additive; and the rheological additive is 0620 rheological additive.

10. A method for preparing a water-based two-component epoxy primer for a bus, using the water-based two-component epoxy primer for a bus according to any one of claims 1 to 9, characterized in that: The following steps are involved: First, a grinding slurry is prepared, and then a finished paint is prepared using the grinding slurry, and preferably the finished paint is mixed with component B to prepare a primer; The preparation steps of the grinding slurry are: Step a1, add deionized water and co-solvent in sequence to start dispersion; then add dispersant and defoamer in sequence, and stir for 10 minutes after all are added; Step b1, according to the raw material ratio, add anti-rust and anti-corrosion pigment, pigment filler, and physical filler in sequence, adjust the speed to 1000-1200rpm after all are added, and disperse at high speed for 20 minutes; Step c1, select a suitable grinder, adjust the grinding parameters, and control the fineness of the grinding slurry to ≤25 μm; The preparation steps of the finished paint are: Step a2, transferring the pre-prepared grinding slurry to a suitable production equipment; Step b2, rotating speed 500-700 rpm, add water-based epoxy resin, anti-rust agent, wetting and leveling agent in sequence, after all are added, stir for 10 minutes; Step c2, rotating speed 600-800 rpm, adding rheological additive to adjust the viscosity of the paint slurry to the design index range, and preparing a finished paint; The preparation steps of the primer are: The epoxy curing agent is added to deionized water for dilution, and then added to the finished paint for mixing to prepare a two-component epoxy primer.

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