Waterborne wet-on-wet epoxy zinc-rich primer and method of making same

Abstract

This invention relates to a water-based wet-on-wet epoxy zinc-rich primer and its preparation method, mainly comprising the following components A and B: Component A is mainly prepared from the following components in the following mass ratios: Component B is mainly prepared from the following components in the following mass ratios: This invention overcomes the shortcomings of existing environmentally friendly water-based zinc-rich primers, which require baking or a relatively long self-drying curing time, resulting in the inability to perform wet-on-wet application and low application efficiency. Through the synergistic effect of a specially designed water-based epoxy resin and modified fatty amine adduct, and the preferred components and their proportions in the system, it has the advantages of being able to perform wet-on-wet application and having excellent performance.

Description

Technical Field

[0001] This invention relates to a water-based wet-on-wet epoxy zinc-rich primer and its preparation method, which is applied in the field of coating production. Background Technology

[0002] The descriptions in this section provide background information related to this disclosure only and do not constitute prior art. With the development of the heavy-duty anti-corrosion industrial coating industry and the introduction of various environmental regulations, the coating industry has also experienced rapid growth, with the market gradually shifting from solvent-based anti-corrosion coatings to water-based products. At the same time, various so-called environmentally friendly water-based zinc-rich primers have emerged, but these coatings require baking or a relatively long self-drying curing time, such as CN201811319599.X, before a second coat can be applied, meaning they cannot be applied wet-on-wet, greatly affecting construction efficiency. Therefore, providing a water-based wet-on-wet epoxy zinc-rich primer that can be applied wet-on-wet, and exhibits excellent freeze-thaw resistance, salt spray resistance, flash rust inhibition, adhesion strength, high non-volatile content, and fast drying speed, along with its preparation method, has become an urgent priority. Summary of the Invention

[0003] To overcome the shortcomings of existing environmentally friendly water-based zinc-rich primers, which require baking or a relatively long self-drying curing time, resulting in the inability to apply wet-on-wet primers and low application efficiency, this invention provides a water-based wet-on-wet epoxy zinc-rich primer and its preparation method. Through the synergistic effect of specially designed water-based epoxy resin and modified fatty amine adduct, along with the preferred components and their dosage ratios in the system, it has the advantages of being able to be applied wet-on-wet, and possessing excellent freeze-thaw resistance, salt spray resistance, flash rust inhibition, bonding strength, high non-volatile content, and fast drying speed.

[0004] The technical solution of the present invention is as follows:

[0005] A water-based wet-on-wet epoxy zinc-rich primer mainly comprises the following components A and B:

[0006] Component A is mainly prepared from the following components in the following mass ratios:

[0007]

[0008] Wherein, the waterborne epoxy resin is an oleophilic epoxy resin modified with waterborne properties; the organic modified anti-settling agent is a polyamide-modified organic anti-settling agent; and the modified extender filler is a low-oil-absorption powder modified powder.

[0009] Component B is mainly prepared from the following components in the following mass ratios:

[0010]

[0011] Among them, the modified fatty amine adduct is a modified fatty amine adduct with the introduction of -si-o- and -coc- structures.

[0012] This application's water-based wet-on-wet epoxy zinc-rich primer, through a specially designed combination of water-based epoxy resin and modified fatty amine adduct, and the synergistic effect of the preferred components and their proportions in the system, allows for wet-on-wet application (i.e., wet-on-wet recoating of intermediate and topcoats). It also boasts advantages such as excellent freeze-thaw resistance, salt spray resistance, flash rust inhibition, superior adhesion strength, high non-volatile content, and fast drying speed. This effectively solves the paint film defects caused by short application intervals, such as blistering, peeling, and rain-induced blistering. Figure 1-2 As can be seen, the introduction of partial silicon-oxygen bonds into the waterborne epoxy resin increases the cohesive force during film formation. Simultaneously, during surface drying, this increased cohesive force makes it difficult for water and co-solvents in the second coating to penetrate to the bottom coating, thus preventing risks such as blistering, peeling, and other defects. Furthermore, the introduction of terminal silicon-oxygen bonds in the modified aliphatic amine adduct enhances the coating's ability to bond with the substrate, significantly improving its water resistance. (For example, an environmentally friendly waterborne zinc-rich primer prepared using a modified aliphatic amine without -Si-O- groups showed only 18 hours of water resistance after 24 hours of self-drying curing, resulting in full-surface blistering. In contrast, the environmentally friendly waterborne zinc-rich primer in this application, using a modified aliphatic amine with -Si-O- groups, showed no change in water resistance after 30 days under the same standard conditions.) This application's waterborne wet-on-wet epoxy zinc-rich primer meets the HG / T3668-2020 epoxy zinc-rich standard. This product overcomes the major challenges of existing water-based products and pioneers the application of water-based products that mimic the workability of oil-based products.

[0013] Among them, the waterborne epoxy resin is made by water-based modification of oleophilic epoxy resin, giving the resin certain hydrophilic properties, thus allowing water to emulsify the resin material well. The organic modified anti-settling agent is made of polyamide and has excellent oil-soluble swelling properties, thus giving the system excellent thixotropic properties, with a TI index as high as 6 or above. Due to this property, the prepared waterborne wet-on-wet epoxy zinc-rich primer coating has excellent anti-sagging properties. The organosilicon defoamer has excellent tension contact points, which can act very effectively on the surface of the bubble film. When it acts on the bubble, due to the high surface tension of the bubble film and the extremely low surface tension of the additive, the large tension difference allows the bubble to break very quickly, resulting in a very smooth and even coating film after side cutting and appearance. The modified zinc powder has excellent cathodic protection properties, and can sacrifice its own end to protect the iron substrate after contact with it. The modified extender filler has a sheet-like structure, which allows it to spread very well in the paint film. This spreading process makes the paint film denser, resulting in a better barrier effect. The modified aliphatic amine adduct has two outstanding characteristics: first, it has a very good ability to emulsify waterborne epoxy resins, and the two are very compatible; second, it has very good fast drying properties and can produce a good hydrophobic and oleophobic interface, thereby solving various paint film defects existing in the current wet-on-wet application process.

[0014] The dispersant is a polymeric dispersant.

[0015] The preferred dispersant is a dispersant specifically designed for zinc-rich products. It has a sufficient number of anchoring groups to disperse modified zinc powder and modified extender fillers, while some of the groups can extend into other solvents and resins in the system to increase the system stability of the coating product.

[0016] The organic modified anti-settling agent is a polyamide-modified wax powder.

[0017] Organic modified anti-settling agents are primarily selected based on two aspects: 50℃ heat storage and anti-sagging properties during product application. Oil-based bentonite or fumed silica lacks good anti-settling and anti-sagging characteristics; in contrast, polyamide wax powder exhibits excellent anti-settling and anti-sagging properties.

[0018] The co-solvent is propylene glycol methyl ether solvent.

[0019] The preferred co-solvent is a good solvent for waterborne epoxy resins, which can effectively reduce the viscosity of the system, making the product more stable during the production process.

[0020] The toughening agent is dipropylene glycol butyl ether.

[0021] The preferred toughening agent is a small molecule toughening agent, which can reduce the overall system MFT, enabling the coating to form a very good film during the film-forming process. At the same time, it can also increase the encapsulation of the film-forming material, making the film density of the coating more compact.

[0022] The water-based wet-on-wet epoxy zinc-rich primer is prepared by mixing component A and component B in a mass ratio of 9:1-11:1 (equivalent ratio refers to the ratio of epoxy equivalent to active hydrogen equivalent).

[0023] This water-based wet-on-wet epoxy zinc-rich primer is easy to use; it only requires simple mixing before application.

[0024] The preparation method of the water-based wet-on-wet epoxy zinc-rich primer includes the following steps:

[0025] (I) Preparation of Component A

[0026] (1) After mixing the waterborne epoxy resin with the cosolvent, start the mixer, adjust the speed to 800-1200 r / min, and disperse for at least 10 minutes to obtain a well dispersed solution.

[0027] (2) Add the dispersant and silicone defoamer to the dispersion obtained in step (1), maintain the rotation speed at 800-1200 r / min, and disperse for at least 10 minutes; then add the organic modified anti-settling agent, maintain the rotation speed at 800-1200 r / min, and disperse for at least 10 minutes; then continue to add the modified zinc powder and modified extender filler, adjust the rotation speed to 2500-3000 r / min and disperse until uniform; finally add the toughening agent, maintain the rotation speed at 2500-3000 r / min, and disperse until uniform to obtain component A;

[0028] (II) Preparation of Component B

[0029] The modified fatty amine adduct, co-solvent, and water are mixed and dispersed until homogeneous; then the anti-flash rust additive is slowly added and dispersed until homogeneous to obtain component B.

[0030] The preparation method of the water-based wet-on-wet epoxy zinc-rich primer is simple and easy to operate.

[0031] The preparation method of the water-based wet-on-wet epoxy zinc-rich primer also includes step (iii) preparing the water-based wet-on-wet epoxy zinc-rich primer: mixing component A and component B evenly in a mass ratio of 9:1-11:1 to obtain the water-based wet-on-wet epoxy zinc-rich primer.

[0032] This water-based wet-on-wet epoxy zinc-rich primer is easy to use; it only requires simple mixing before application.

[0033] Compared with the prior art, this invention application has the following advantages:

[0034] 1) The water-based wet-on-wet epoxy zinc-rich primer of this application combines specially designed water-based epoxy resin with modified fatty amine adducts, and has the advantages of wet-on-wet application, freeze-thaw resistance, salt spray resistance, flash rust inhibition, excellent bonding strength, high non-volatile content, and fast drying speed through the synergistic effect of each preferred component and its dosage ratio in the system.

[0035] 2) The preferred dispersant is a dispersant for zinc-rich products, which has a sufficient number of anchoring groups to act on anti-flash rust additives and modified extender fillers. At the same time, some groups can extend to other solvents and resins in the system to increase the system stability of the coating product.

[0036] 3) The preferred co-solvent is a good solvent for waterborne epoxy resin, which can effectively reduce the viscosity of the system, making the product more stable during the production process;

[0037] 4) The preferred toughening agent is a small molecule toughening agent, which can reduce the overall MFT of the system, so that the coating can form a film very well during the film formation process. At the same time, it can also increase the encapsulation of the film-forming material, making the film density of the coating more compact.

[0038] 5) This water-based wet-on-wet epoxy zinc-rich primer is easy to use; it only requires simple mixing before application.

[0039] 6) The preparation method of the water-based wet-on-wet epoxy zinc-rich primer is simple and easy to operate. Attached Figure Description

[0040] Figure 1 This is a schematic diagram of the structure of the waterborne epoxy resin in the waterborne wet-on-wet epoxy zinc-rich primer described in this invention.

[0041] Figure 2 This is a schematic diagram of the structure of the modified fatty amine adduct of the water-based wet-on-wet epoxy zinc-rich primer described in this invention. Detailed Implementation

[0042] The technical solution of the present invention will be clearly and completely described below with reference to specific embodiments. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0043] Example 1

[0044] The water-based wet-on-wet epoxy zinc-rich primer of this invention mainly comprises the following components A and B:

[0045] Component A is mainly prepared from the following components in the following mass ratios:

[0046]

[0047] Wherein, the waterborne epoxy resin is an oleophilic epoxy resin modified with waterborne properties; the organic modified anti-settling agent is a polyamide-modified organic anti-settling agent; and the modified extender filler is a low-oil-absorption powder modified powder.

[0048] Component B is mainly prepared from the following components in the following mass ratios:

[0049]

[0050] Among them, the modified fatty amine adduct is a modified fatty amine adduct with the introduction of -si-o- and -coc- structures.

[0051] The dispersant is a polymeric dispersant.

[0052] The organic modified anti-settling agent is a polyamide-modified wax powder.

[0053] The co-solvent is propylene glycol methyl ether solvent.

[0054] The toughening agent is dipropylene glycol butyl ether.

[0055] The water-based wet-on-wet epoxy zinc-rich primer is prepared by mixing component A and component B in a mass ratio of 10:1 during use.

[0056] The method for preparing the water-based wet-on-wet epoxy zinc-rich primer includes the following steps:

[0057] (I) Preparation of Component A

[0058] (1) After mixing the waterborne epoxy resin with the cosolvent, start the mixer, adjust the speed to 800 r / min, and disperse for 12 minutes to obtain a well dispersed solution.

[0059] (2) Add the dispersant and silicone defoamer to the dispersion obtained in step (1), maintain the rotation speed at 800 r / min, and disperse for 12 minutes; then add the organic modified anti-settling agent, maintain the rotation speed at 800 r / min, and disperse for 12 minutes; then continue to add the modified zinc powder and modified extender filler, adjust the rotation speed to 3000 r / min and disperse until uniform; finally add the toughening agent, maintain the rotation speed at 3000 r / min and disperse until uniform, thus obtaining component A;

[0060] (II) Preparation of Component B

[0061] The modified fatty amine adduct, co-solvent, and water are mixed and dispersed until homogeneous; then the anti-flash rust additive is slowly added and dispersed until homogeneous to obtain component B.

[0062] The preparation method of the water-based wet-on-wet epoxy zinc-rich primer also includes step (iii) preparing the water-based wet-on-wet epoxy zinc-rich primer: mixing component A and component B in a mass ratio of 10:1 to obtain the water-based wet-on-wet epoxy zinc-rich primer.

[0063] Example 2

[0064] The water-based wet-on-wet epoxy zinc-rich primer of this invention mainly comprises the following components A and B:

[0065] Component A is mainly prepared from the following components in the following mass ratios:

[0066]

[0067]

[0068] Wherein, the waterborne epoxy resin is an oleophilic epoxy resin modified with waterborne properties; the organic modified anti-settling agent is a polyamide-modified organic anti-settling agent; and the modified extender filler is a low-oil-absorption powder modified powder.

[0069] Component B is mainly prepared from the following components in the following mass ratios:

[0070]

[0071] Among them, the modified fatty amine adduct is a modified fatty amine adduct with the introduction of -si-o- and -coc- structures.

[0072] The dispersant is a polymeric dispersant.

[0073] The organic modified anti-settling agent is a polyamide-modified wax powder.

[0074] The co-solvent is propylene glycol methyl ether solvent.

[0075] The toughening agent is dipropylene glycol butyl ether.

[0076] The water-based wet-on-wet epoxy zinc-rich primer is prepared by mixing component A and component B in a mass ratio of 9:1 during use.

[0077] The method for preparing the water-based wet-on-wet epoxy zinc-rich primer includes the following steps:

[0078] (I) Preparation of Component A

[0079] (1) After mixing the waterborne epoxy resin with the cosolvent, start the mixer, adjust the speed to 1000 r / min, disperse for 10 minutes to obtain a well dispersed solution;

[0080] (2) Add the dispersant and silicone defoamer to the dispersion obtained in step (1), maintain the rotation speed at 1000 r / min, and disperse for 10 minutes; then add the organic modified anti-settling agent, maintain the rotation speed at 1000 r / min, and disperse for 10 minutes; then continue to add the modified zinc powder and modified extender filler, adjust the rotation speed to 2800 r / min, and disperse until uniform; finally add the toughening agent, maintain the rotation speed at 2800 r / min, and disperse until uniform to obtain component A;

[0081] (II) Preparation of Component B

[0082] The modified fatty amine adduct, co-solvent, and water are mixed and dispersed until homogeneous; then the anti-flash rust additive is slowly added and dispersed until homogeneous to obtain component B.

[0083] The preparation method of the water-based wet-on-wet epoxy zinc-rich primer also includes step (iii) preparing the water-based wet-on-wet epoxy zinc-rich primer: mixing component A and component B evenly in a mass ratio of 9:1 to obtain the water-based wet-on-wet epoxy zinc-rich primer.

[0084] Example 3

[0085] The water-based wet-on-wet epoxy zinc-rich primer of this invention mainly comprises the following components A and B:

[0086] Component A is mainly prepared from the following components in the following mass ratios:

[0087]

[0088] Wherein, the waterborne epoxy resin is an oleophilic epoxy resin modified with waterborne properties; the organic modified anti-settling agent is a polyamide-modified organic anti-settling agent; and the modified extender filler is a low-oil-absorption powder modified powder.

[0089] Component B is mainly prepared from the following components in the following mass ratios:

[0090]

[0091] Among them, the modified fatty amine adduct is a modified fatty amine adduct with the introduction of -si-o- and -coc- structures.

[0092] The dispersant is a polymeric dispersant.

[0093] The organic modified anti-settling agent is a polyamide-modified wax powder.

[0094] The co-solvent is propylene glycol methyl ether solvent.

[0095] The toughening agent is dipropylene glycol butyl ether.

[0096] The water-based wet-on-wet epoxy zinc-rich primer is prepared by mixing component A and component B in a mass ratio of 11:1 during use.

[0097] The method for preparing the water-based wet-on-wet epoxy zinc-rich primer includes the following steps:

[0098] (I) Preparation of Component A

[0099] (1) After mixing the waterborne epoxy resin with the cosolvent, start the mixer, adjust the speed to 1200 r / min, disperse for 15 minutes to obtain a well dispersed solution;

[0100] (2) Add the dispersant and silicone defoamer to the dispersion obtained in step (1), maintain the rotation speed at 1200 r / min, and disperse for at least 10 minutes; then add the organic modified anti-settling agent, maintain the rotation speed at 1200 r / min, and disperse for 15 minutes; then continue to add the modified zinc powder and modified extender filler, adjust the rotation speed to 2500 r / min and disperse until uniform; finally add the toughening agent, maintain the rotation speed at 2500 r / min and disperse until uniform, thus obtaining component A;

[0101] (II) Preparation of Component B

[0102] The modified fatty amine adduct, co-solvent, and water are mixed and dispersed until homogeneous; then the anti-flash rust additive is slowly added and dispersed until homogeneous to obtain component B.

[0103] The preparation method of the water-based wet-on-wet epoxy zinc-rich primer also includes step (iii) preparing the water-based wet-on-wet epoxy zinc-rich primer: mixing component A and component B evenly in a mass ratio of 11:1 to obtain the water-based wet-on-wet epoxy zinc-rich primer.

[0104] Manufacturer Information:

[0105] Waterborne epoxy resin: AQUAER-3009, Jiangsu Fuqisen New Material Co., Ltd.;

[0106] Dispersant: Polymer type dispersant, model 6208, Zhanxin Company;

[0107] Organic modified anti-settling agent: polyamide modified wax powder, AQUAER-153, Jiangsu Fuqisen New Materials;

[0108] Organosilicon defoamer: TEGO-810, DIGIC;

[0109] Toughening agent: dipropylene glycol butyl ether, Dow Chemical;

[0110] Modified zinc powder: Hunan Xinweiling, its preparation method: pyrrole and ferric chloride hexahydrate are dispersed in a mixed solution composed of ethanol and hydrogen peroxide, then zinc powder is added to the mixed solution and ultrasonically treated, and then stirring is continued to obtain the modified zinc powder;

[0111] Modified extender filler: Low oil absorption modified powder (oil absorption value <15), Shijiazhuang Yourong Chemical 908;

[0112] Cosolvent: Propylene glycol methyl ether solvent, Dow Chemical.

[0113] Modified fatty amine adduct: AQUAER-3123, Jiangsu Fuqisen New Materials.

[0114] Experimental data:

[0115] Testing method: Each property was tested according to the HG / T 3668-2020 standard for zinc-rich epoxy resin;

[0116] The results are shown in Table 1:

[0117] Table 1. Performance parameter test results for each embodiment.

[0118]

[0119]

[0120] As can be seen from Table 1, all embodiments provided by the present invention meet the HG / T 3668-2020 epoxy zinc-rich standard. In addition, in terms of non-standard performance beyond the standard, our products can be applied wet-on-wet, and the effect is excellent (freeze-thaw resistance, salt spray resistance, flash rust inhibition, excellent bonding strength, high non-volatile content, and fast drying speed).

Claims

1. A water-based wet-on-wet epoxy zinc-rich primer, characterized in that: It mainly contains the following components A and B: Component A is mainly prepared from the following components in the following mass ratios: 15-20 parts of waterborne epoxy resin Dispersant 0.5-1 part 0.5-1 part of organic modified anti-settling agent 0.2-0.5 parts of silicone defoamer 1-2 parts toughening agent 50-60 parts of modified zinc powder 20-30 parts of modified extender filler 8-10 parts of co-solvent; Wherein, the waterborne epoxy resin is an oleophilic epoxy resin that has been modified into a waterborne form; the organic modified anti-settling agent is a polyamide-modified organic anti-settling agent; and the modified extender filler is a low-oil-absorption modified powder. Component B is mainly prepared from the following components in the following mass ratios: 40-50 parts of modified fatty amine adduct 20-30 parts water 10-20 parts of cosolvent Anti-flash rust additive 5-10 parts; Among them, the modified fatty amine adduct is a modified fatty amine adduct with the introduction of -si-o- and -coc- structures; The dispersant is a polymeric dispersant.

2. The water-based wet-on-wet epoxy zinc-rich primer according to claim 1, characterized in that: The organic modified anti-settling agent is a polyamide-modified wax powder.

3. The water-based wet-on-wet epoxy zinc-rich primer according to claim 1, characterized in that: The co-solvent is propylene glycol methyl ether solvent.

4. The water-based wet-on-wet epoxy zinc-rich primer according to claim 1, characterized in that: The toughening agent is dipropylene glycol butyl ether.

5. The water-based wet-on-wet epoxy zinc-rich primer according to claim 1, characterized in that: The water-based wet-on-wet epoxy zinc-rich primer is prepared by mixing component A and component B in a mass ratio of 9:1 to 11:1 during use.

6. The method for preparing the water-based wet-on-wet epoxy zinc-rich primer according to any one of claims 1-5, characterized in that: Includes the following steps: (a) Preparation of component A (1) After mixing the water-based epoxy resin with the co-solvent, start the mixer, adjust the speed to 800-1200 r / min, and disperse for at least 10 minutes to obtain a well-dispersed solution; (2) Add the dispersant and silicone defoamer to the dispersion obtained in step (1), maintain the rotation speed at 800-1200 r / min, and disperse for at least 10 minutes; then add the organic modified anti-settling agent, maintain the rotation speed at 800-1200 r / min, and disperse for at least 10 minutes; then continue to add the modified zinc powder and modified extender filler, adjust the rotation speed to 2500-3000 r / min and disperse until uniform; finally add the toughening agent, maintain the rotation speed at 2500-3000 r / min and disperse until uniform, thus obtaining component A; (II) Preparation of Component B The modified fatty amine adduct, co-solvent, and water are mixed and dispersed until homogeneous; then the anti-flash rust additive is slowly added and dispersed until homogeneous to obtain component B.

7. The method for preparing the water-based wet-on-wet epoxy zinc-rich primer according to claim 6, characterized in that: The preparation method of the water-based wet-on-wet epoxy zinc-rich primer also includes step (iii) preparing the water-based wet-on-wet epoxy zinc-rich primer: mixing component A and component B evenly in a mass ratio of 9:1-11:1 to obtain the water-based wet-on-wet epoxy zinc-rich primer.

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