A waterborne epoxy coating and a method for preparing the same

Abstract

The application discloses a kind of water-based epoxy coating and preparation method thereof, the water-based epoxy coating is made of the following weight parts of raw materials, modified epoxy resin emulsion 65~80 parts, polyamide resin 20~30 parts, barium sulfate 0.5~5 parts, defoaming agent 1~4 parts, deionized water 10~20 parts, crosslinking agent 5~10 parts, curing agent 1~3 parts, zinc powder 40~60 parts, modified sol 6~12 parts and modified nanometer rare earth 15~30 parts.The application adds modified sol and zinc powder, on the one hand, modified sol material can be used as the carrier of dispersed zinc powder, which can make zinc powder more evenly dispersed in the coating;On the other hand, modified sol material has strong toughening performance, which can provide good support and coating after coating film formation, thereby improving the strength and durability of coating.

Description

Technical Field

[0001] The present invention relates to the technical field of epoxy coating preparation, and in particular to a water-based epoxy coating and a preparation method thereof. Background Art

[0002] Waterborne epoxy coatings are coatings that use water as a solvent or dispersion medium. Waterborne epoxy coatings include water-soluble epoxy coatings and water-emulsified coatings. Water-soluble coatings are often also called electrophoretic coatings, that is, the resin is dissolved in water to form a uniform colloidal solution. If the resin ions are charged, under the action of direct current, the colloidal particles can be discharged and deposited on the surface of the workpiece by electrophoresis. Waterborne epoxy resin coatings have excellent metal adhesion and corrosion resistance, as well as good chemical stability and bonding properties. Waterborne epoxy resin coatings are currently the focus of research in the coatings industry.

[0003] The addition of various synergistic materials to water-based coatings is key to improving the long-term corrosion resistance of coatings. However, simply adding various anti-corrosion materials will inevitably lead to agglomeration between the components in the coating. Agglomerated additives not only fail to achieve the effect of enhancing density, but may also reduce the mechanical properties of the coating, thereby shortening the coating life. Summary of the Invention

[0004] The problem to be solved by the present invention is to provide a water-based epoxy coating and a preparation method thereof. By adding modified sol and zinc powder, on the one hand, the modified sol material can serve as a carrier for dispersing zinc powder, so that the zinc powder can be dispersed more evenly inside the coating; on the other hand, the modified sol material has strong toughening properties and can provide good support and coating after the coating is formed into a film, thereby improving the strength and durability of the coating.

[0005] The present invention provides a technical solution for solving the above problems: a water-based epoxy coating, which is made of the following raw materials in parts by weight: 65-80 parts of modified epoxy resin emulsion, 20-30 parts of polyamide resin, 0.5-5 parts of barium sulfate, 1-4 parts of defoaming agent, 10-20 parts of deionized water, 5-10 parts of cross-linking agent, 1-3 parts of curing agent, 40-60 parts of zinc powder, 6-12 parts of modified sol and 15-30 parts of modified nano rare earth.

[0006] Preferably, the water-based epoxy coating is made of the following raw materials in parts by weight: 65 parts of modified epoxy resin emulsion, 25 parts of polyamide resin, 1 part of barium sulfate, 1 part of defoaming agent, 10 parts of deionized water, 8 parts of crosslinking agent, 1 part of curing agent, 50 parts of zinc powder, 12 parts of modified sol and 20 parts of modified nano rare earth.

[0007] Preferably, the water-based epoxy coating is made of the following raw materials in parts by weight: 70 parts of modified epoxy resin emulsion, 20 parts of polyamide resin, 2 parts of barium sulfate, 3 parts of defoaming agent, 15 parts of deionized water, 5 parts of crosslinking agent, 2 parts of curing agent, 40 parts of zinc powder, 6 parts of modified sol and 15 parts of modified nano rare earth.

[0008] Preferably, the water-based epoxy coating is made of the following raw materials in parts by weight: 80 parts of modified epoxy resin emulsion, 22 parts of polyamide resin, 5 parts of barium sulfate, 4 parts of defoaming agent, 20 parts of deionized water, 10 parts of crosslinking agent, 3 parts of curing agent, 60 parts of zinc powder, 8 parts of modified sol and 30 parts of modified nano rare earth.

[0009] The present invention also discloses a method for preparing a waterborne epoxy coating as described in any one of the above, the method comprising the following steps:

[0010] S1, preparing modified sol;

[0011] S2, preparing modified nano rare earth;

[0012] S3, preparing modified epoxy resin emulsion;

[0013] S4, placing the modified epoxy resin emulsion and polyamide resin into a special mixing device and mixing them evenly, heating them to 50-70°C for reaction for 20-35 minutes, adding the modified nano rare earth, and mixing them at 80-100°C for 20-35 minutes;

[0014] S5. Add barium sulfate, defoaming agent, cross-linking agent, curing agent, zinc powder and modified sol into a special mixing device in sequence;

[0015] S6. Raise the temperature to 120-150°C and react for 20-30 minutes to obtain a water-based epoxy coating.

[0016] Preferably, the preparation method of the modified sol in S1 comprises the following steps:

[0017] S1.1. Take titanium dioxide sol, zirconium dioxide sol and silicon dioxide sol in proportion;

[0018] S1.2. Place titanium dioxide sol, zirconium dioxide sol and silicon dioxide sol into a special mixing device and mix them to obtain a modified sol;

[0019] Preferably, the ratio of the titanium dioxide sol, zirconium dioxide sol and silicon dioxide sol is 1:1:3.

[0020] Preferably, the preparation method of the modified nano rare earth in S2 comprises the following steps:

[0021] S2.1. Take nano-lanthanum borate, nano-rare earth and silane coupling agent in proportion;

[0022] S2.2. Place nano-lanthanum borate, nano-rare earth and silane coupling agent into a special mixing device and mix them evenly to obtain modified nano-rare earth.

[0023] Preferably, the preparation method of the modified epoxy resin emulsion comprises the following steps:

[0024] S3.1, mixing nano-titanium dioxide, nano-zinc phosphate and epoxy resin and adding them into a kneader for reaction;

[0025] S3.2, then add the initiator, stir evenly and keep warm for 6 hours to obtain the modified epoxy resin;

[0026] S3.3. Add deionized water and ethylenediamine for emulsification and dispersion to obtain a modified epoxy resin emulsion.

[0027] Preferably, the special mixing device in S4 includes a stirring barrel and a stirring assembly; the stirring assembly is used to stir the material in the stirring barrel; the stirring assembly includes a stirring motor, a stirring shaft, an auxiliary lifting stirring mechanism and a plurality of stirring paddles; the stirring motor is installed at the upper end of the stirring barrel, one end of the stirring shaft is connected to the motor belt transmission, and the other end extends into the stirring barrel, and the plurality of stirring paddles are evenly distributed on the stirring shaft, and the auxiliary lifting stirring mechanism rises and falls in the stirring barrel to stir the material in the stirring barrel up and down so that the material is stirred more evenly.

[0028] Compared with the prior art, the advantages of the present invention are: by adding modified sol and zinc powder, on the one hand, the modified sol material can serve as a carrier for dispersing zinc powder, so that the zinc powder can be dispersed more evenly inside the coating; on the other hand, the modified sol material has strong toughening properties, which can provide good support and coating after the coating is formed into a film, thereby improving the strength and durability of the coating. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The drawings described herein are used to provide further understanding of the present invention and constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0030] Figure 1 This is a flowchart of the preparation process of the polyurethane coating of the present invention;

[0031] Figure 2 This is a flowchart of the preparation process of the chitosan modified coupling agent solution of the present invention;

[0032] Figure 3 This is a flowchart of the preparation process of the modified wollastonite of the present invention;

[0033] Figure 4 The present invention

[0034] Figure 5 It is a schematic structural diagram of the special mixing device of the present invention;

[0035] Figure 6 is a cross-sectional view of a special mixing device of the present invention;

[0036] Figure 7 yes Figure 6 A magnified schematic diagram of point A in the middle;

[0037] Figure 8 is a top view of the auxiliary lifting and stirring mechanism of the present invention;

[0038] Figure 9 This is a schematic diagram of the positioning axis of the present invention Figure 1 ;

[0039] Figure 10 This is a schematic diagram of the positioning axis of the present invention Figure 2 .

[0040] The attached drawings are marked with: 1. Mixing barrel, 2. Mixing motor, 3. Upper cover, 4. Positioning shaft, 5. Mixing frame, 6. Mixing shaft, 7. Mixing paddle, 8. Mixing blade, 9. Scraper 1, 10. Scraper 2, 11. Connecting head, 12. Guide head, 13. Movable hole, 14. Spiral rising groove, 15. Reset groove. DETAILED DESCRIPTION

[0041] The following will describe the embodiments of the present invention in detail with reference to the accompanying drawings and examples, so that the implementation process of how the present invention applies technical means to solve technical problems and achieve technical effects can be fully understood and implemented accordingly.

[0042] In the description of the present invention, it should be noted that, for directional words, such as the terms "center", "horizontal", "longitudinal", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like, indicating directions and positional relationships, are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and cannot be understood as limiting the specific scope of protection of the present invention.

[0043] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features. Therefore, the terms "first" and "second" may explicitly or implicitly refer to one or more of these features. Throughout the description of the present invention, "several" means two or more, unless otherwise specifically defined.

[0044] In the present invention, unless otherwise specified or limited, the terms "assemble," "connect," and "connect" should be understood in a broad sense. For example, they may refer to fixed connection, detachable connection, or integral connection; mechanical connection; direct connection, connection through an intermediate medium, or internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0045] It will be understood that when used in this specification and the appended claims, the terms “comprises” and “comprising” indicate the presence of described features, integers, steps, operations, elements and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or groups thereof.

[0046] It should also be understood that the terms used in this description of the embodiments of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the embodiments of the present invention. As used in the description of the embodiments of the present invention and the appended claims, the singular forms "a", "an", and "the" are intended to include the plural forms unless the context clearly indicates otherwise.

[0047] Example 1

[0048] This embodiment discloses a water-based epoxy coating, which is made of the following raw materials in parts by weight: 65-80 parts of modified epoxy resin emulsion, 20-30 parts of polyamide resin, 0.5-5 parts of barium sulfate, 1-4 parts of defoaming agent, 10-20 parts of deionized water, 5-10 parts of cross-linking agent, 1-3 parts of curing agent, 40-60 parts of zinc powder, 6-12 parts of modified sol and 15-30 parts of modified nano rare earth.

[0049] In the above scheme, by adding modified sol and zinc powder, on the one hand, the modified sol material can serve as a carrier for dispersing zinc powder, which can make the zinc powder more evenly dispersed inside the coating; on the other hand, the modified sol material has strong toughening properties, which can provide good support and coating after the coating is formed into a film, thereby improving the strength and durability of the coating; at the same time, the modified epoxy resin emulsion is modified by nano-titanium dioxide and nano-zinc phosphate, so that the nanoparticles are evenly dispersed in the epoxy resin emulsion, and the nanoparticles make the prepared wood paint have better leveling properties; and the surface of the modified nano rare earth has a wear-resistant surface layer, which can increase the overall wear resistance of the water-based epoxy coating.

[0050] Example 2

[0051] This embodiment discloses a water-based epoxy coating, which is made of the following raw materials in parts by weight: 65 parts of modified epoxy resin emulsion, 25 parts of polyamide resin, 1 part of barium sulfate, 1 part of defoaming agent, 10 parts of deionized water, 8 parts of cross-linking agent, 1 part of curing agent, 50 parts of zinc powder, 12 parts of modified sol and 20 parts of modified nano rare earth.

[0052] Example 3

[0053] This embodiment discloses a water-based epoxy coating, which is made of the following raw materials in parts by weight: 70 parts of modified epoxy resin emulsion, 20 parts of polyamide resin, 2 parts of barium sulfate, 3 parts of defoaming agent, 15 parts of deionized water, 5 parts of cross-linking agent, 2 parts of curing agent, 40 parts of zinc powder, 6 parts of modified sol and 15 parts of modified nano rare earth.

[0054] Example 4

[0055] This embodiment discloses a water-based epoxy coating, which is made of the following raw materials in parts by weight: 80 parts of modified epoxy resin emulsion, 22 parts of polyamide resin, 5 parts of barium sulfate, 4 parts of defoaming agent, 20 parts of deionized water, 10 parts of cross-linking agent, 3 parts of curing agent, 60 parts of zinc powder, 8 parts of modified sol and 30 parts of modified nano rare earth.

[0056] Example 5

[0057] This embodiment discloses a method for preparing a waterborne epoxy coating as described in any one of embodiments 1-4, the preparation method comprising the following steps:

[0058] S1, preparing modified sol;

[0059] S2, preparing modified nano rare earth;

[0060] S3, preparing modified epoxy resin emulsion;

[0061] S4, placing the modified epoxy resin emulsion and polyamide resin into a special mixing device and mixing them evenly, heating them to 50-70°C for reaction for 20-35 minutes, adding the modified nano rare earth, and mixing them at 80-100°C for 20-35 minutes;

[0062] S5. Add barium sulfate, defoaming agent, cross-linking agent, curing agent, zinc powder and modified sol into a special mixing device in sequence;

[0063] S6. Raise the temperature to 120-150°C and react for 20-30 minutes to obtain a water-based epoxy coating.

[0064] In this embodiment, specifically, the preparation method of the modified sol in S1 includes the following steps:

[0065] S1.1. Take titanium dioxide sol, zirconium dioxide sol and silicon dioxide sol in proportion;

[0066] S1.2. Place titanium dioxide sol, zirconium dioxide sol and silicon dioxide sol into a special mixing device and mix them evenly to obtain modified sol.

[0067] Furthermore, the ratio of the titanium dioxide sol, zirconium dioxide sol and silicon dioxide sol is 1:1:3.

[0068] In this embodiment, specifically, the preparation method of the modified nano rare earth in S2 includes the following steps:

[0069] S2.1. Take nano-lanthanum borate, nano-rare earth and silane coupling agent in proportion;

[0070] S2.2. Place nano-lanthanum borate, nano-rare earth and silane coupling agent into a special mixing device and mix them evenly to obtain modified nano-rare earth.

[0071] In this embodiment, specifically, the preparation method of the modified epoxy resin emulsion includes the following steps:

[0072] S3.1, mixing nano-titanium dioxide, nano-zinc phosphate and epoxy resin and adding them into a kneader for reaction;

[0073] S3.2, then add the initiator, stir evenly and keep warm for 6 hours to obtain the modified epoxy resin;

[0074] S3.3. Add deionized water and ethylenediamine for emulsification and dispersion to obtain a modified epoxy resin emulsion.

[0075] Example 6

[0076] This embodiment discloses a special mixing device, which includes a stirring barrel 1 and a stirring assembly; the stirring assembly is used to stir the material in the stirring barrel 1.

[0077] In this embodiment, specifically, the stirring assembly includes a stirring motor 2, a stirring shaft 6, an auxiliary lifting stirring mechanism and a plurality of stirring paddles 7; the stirring motor 2 is installed at the upper end of the stirring barrel 1, one end of the stirring shaft 6 is connected to the motor belt drive, and the other end extends into the stirring barrel 1, and the plurality of stirring paddles 7 are evenly distributed on the stirring shaft 6, and the auxiliary lifting stirring mechanism rises and falls in the stirring barrel 1 to stir the material in the stirring barrel 1 up and down so that the material is stirred more evenly.

[0078] The auxiliary lifting and stirring mechanism includes a positioning shaft 4, a stirring frame 5 and a connecting head 11. The positioning shaft 4 is arranged at the center position of the lower end surface of the upper cover 3 of the mixing barrel 1. The positioning shaft 4 is provided with a matching hole for the stirring shaft 6 to pass through. The connecting head 11 is provided with a movable hole 13 that cooperates with the outer ring of the positioning shaft 4. A guide head 12 is provided in the movable hole 13. The outer circumferential surface of the positioning shaft 4 is provided with a guide groove that cooperates with the guide head 12. The guide groove includes a spiral rising groove 14 and a reset groove 15. The spiral rising groove 14 is spirally arranged on the positioning shaft 4. One end of the reset groove 15 is connected to the bottom of the spiral rising groove 14, and the other end is connected to the top of the spiral rising groove 14. The stirring frame 5 is connected to the outer circumferential surface of the connecting head 11. The stirring frame 5 includes a frame body, a plurality of scrapers 9 and a plurality of stirring blades 8. The scraper 9 is vertically arranged on the frame body, and the stirring blade 8 is horizontally arranged on the frame body. The stirring blade 8 is provided with a scraper 2 10 on the side close to the mixing barrel 1.

[0079] At the same time, the stirring blades on the stirring frame rotate up and down and reciprocate under the drive of the stirring frame, thereby improving the stirring effect of the material in the stirring barrel.

[0080] The above description is merely a description of the preferred embodiment of the present invention and is not to be construed as limiting the scope of the claims. The present invention is not limited to the above embodiment, and variations in the specific structure are permitted. Any variations within the scope of the independent claims of the present invention are also within the scope of protection of the present invention.

Claims

1. A method for preparing a waterborne epoxy coating, characterized in that: The waterborne epoxy coating is made of the following raw materials in parts by weight: 65-80 parts of modified epoxy resin emulsion, 20-30 parts of polyamide resin, 0.5-5 parts of barium sulfate, 1-4 parts of defoaming agent, 10-20 parts of deionized water, 5-10 parts of crosslinking agent, 1-3 parts of curing agent, 40-60 parts of zinc powder, 6-12 parts of modified sol and 15-30 parts of modified nano rare earth; The preparation method comprises the following steps: S1, preparing modified sol; S2, preparing modified nano rare earth; S3, preparing modified epoxy resin emulsion; S4, placing the modified epoxy resin emulsion and polyamide resin into a special mixing device and mixing them evenly, heating them to 50-70°C for reaction for 20-35 minutes, adding the modified nano rare earth, and mixing them at 80-100°C for 20-35 minutes; S5. Add barium sulfate, defoaming agent, cross-linking agent, curing agent, zinc powder and modified sol into a special mixing device in sequence; S6. Raise the temperature to 120-150° C. and react for 20-30 minutes to obtain a water-based epoxy coating; The dedicated mixing device in S4 includes a stirring barrel and a stirring assembly; the stirring assembly is used to stir the material in the stirring barrel; the stirring assembly includes a stirring motor, a stirring shaft, an auxiliary lifting stirring mechanism and a plurality of stirring paddles; the stirring motor is installed at the upper end of the stirring barrel, one end of the stirring shaft is connected to the motor belt transmission, and the other end extends into the stirring barrel, the plurality of stirring paddles are evenly distributed on the stirring shaft, and the auxiliary lifting stirring mechanism rises and falls in the stirring barrel to stir the material in the stirring barrel up and down so that the material is stirred more evenly; The auxiliary lifting and stirring mechanism includes a positioning shaft, a stirring frame and a connecting head. The positioning shaft is arranged at the center position of the lower end surface of the upper cover of the mixing barrel. The positioning shaft is provided with a matching hole for the stirring shaft to pass through. The connecting head is provided with a movable hole that cooperates with the outer ring of the positioning shaft. A guide head is provided in the movable hole. A guide groove that cooperates with the guide head is provided on the outer circumferential surface of the positioning shaft. The guide groove includes a spiral rising groove and a reset groove. The spiral rising groove is spirally arranged on the positioning shaft. One end of the reset groove is connected with the bottom of the spiral rising groove, and the other end is connected with the top of the spiral rising groove. The stirring frame is connected to the outer circumferential surface of the connecting head. The stirring frame includes a frame body, a plurality of scraper blades and a plurality of stirring blades. Scraper blade 1 is vertically arranged on the frame body, and the stirring blade is horizontally arranged on the frame body. Scraper blade 2 is provided on the side of the stirring blade close to the mixing barrel.

2. The method for preparing a waterborne epoxy coating according to claim 1, wherein: The water-based epoxy coating is prepared from the following raw materials in parts by weight: 65 parts of modified epoxy resin emulsion, 25 parts of polyamide resin, 1 part of barium sulfate, 1 part of defoamer, 10 parts of deionized water, 8 parts of crosslinking agent, 1 part of curing agent, 50 parts of zinc powder, 12 parts of modified sol and 20 parts of modified nano rare earth.

3. The method for preparing a waterborne epoxy coating according to claim 1, wherein: The water-based epoxy coating is prepared from the following raw materials in parts by weight: 70 parts of modified epoxy resin emulsion, 20 parts of polyamide resin, 2 parts of barium sulfate, 3 parts of defoaming agent, 15 parts of deionized water, 5 parts of crosslinking agent, 2 parts of curing agent, 40 parts of zinc powder, 6 parts of modified sol and 15 parts of modified nano rare earth.

4. The method for preparing a waterborne epoxy coating according to claim 1, wherein: The water-based epoxy coating is prepared from the following raw materials in parts by weight: 80 parts of modified epoxy resin emulsion, 22 parts of polyamide resin, 5 parts of barium sulfate, 4 parts of defoaming agent, 20 parts of deionized water, 10 parts of crosslinking agent, 3 parts of curing agent, 60 parts of zinc powder, 8 parts of modified sol and 30 parts of modified nano rare earth.

5. The method for preparing a waterborne epoxy coating according to claim 1, wherein: The preparation method of the modified sol in S1 comprises the following steps: S1.

1. Take titanium dioxide sol, zirconium dioxide sol and silicon dioxide sol in proportion; S1.

2. Place titanium dioxide sol, zirconium dioxide sol and silicon dioxide sol into a special mixing device and mix them evenly to obtain modified sol.

6. The method for preparing a waterborne epoxy coating according to claim 5, wherein: The ratio of the titanium dioxide sol, zirconium dioxide sol and silicon dioxide sol is 1:1:

3.

7. The method for preparing a waterborne epoxy coating according to claim 1, wherein: The preparation method of the modified nano rare earth in S2 comprises the following steps: S2.

1. Take nano-lanthanum borate, nano-rare earth and silane coupling agent in proportion; S2.

2. Place nano-lanthanum borate, nano-rare earth and silane coupling agent into a special mixing device and mix them evenly to obtain modified nano-rare earth.

8. The method for preparing a waterborne epoxy coating according to claim 1, wherein: The preparation method of the modified epoxy resin emulsion comprises the following steps: S3.1, mixing nano-titanium dioxide, nano-zinc phosphate and epoxy resin and adding them into a kneader for reaction; S3.2, then add the initiator, stir evenly and keep warm for 6 hours to obtain the modified epoxy resin; S3.

3. Add deionized water and ethylenediamine for emulsification and dispersion to obtain a modified epoxy resin emulsion.

Images