Waterborne epoxy coating and preparation method thereof

Abstract

The invention discloses a waterborne epoxy coating and a preparation method thereof, and the waterborne epoxy coating is prepared from 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 a defoaming agent, 10-20 parts of deionized water, 5-10 parts of a cross-linking agent, 1-3 parts of a curing agent, 40-60 parts of zinc powder, 6-12 parts of modified sol and 15-30 parts of modified nano rare earth. By adding the modified sol and the zinc powder, on one hand, the modified sol material can be used as a carrier for dispersing the zinc powder, so that the zinc powder can be more uniformly dispersed in the coating; and on the other hand, the modified sol material has relatively strong toughening performance, and can provide good support and coating after the coating forms a film, so that the strength and durability of the coating are improved.

Description

Technical Field

[0001] The 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] Adding various synergistic materials to water-based coatings is the key to improving the long-term anti-corrosion performance of coatings. However, simply adding various anti-corrosion materials will inevitably lead to agglomeration between the components in the coating, and the agglomerated added materials will not only fail to achieve the effect of enhancing density, but may also reduce the mechanical properties of the coating, thereby reducing 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 be used 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 performance, 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 technical solution provided by the present invention for solving the above problems is: 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 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.

[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 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.

[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 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.

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

[0014] S5, adding 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, put titanium dioxide sol, zirconium dioxide sol and silicon dioxide sol into a special mixing device and mix them to obtain modified sol;

[0019] Preferably, the ratio of the titanium dioxide sol, the zirconium dioxide sol and the 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 is lifted up and down in the stirring barrel to stir the material in the stirring barrel up and down so that the material can be 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 be used 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 performance, and 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 It is a flowchart of the preparation process of the polyurethane coating of the present invention;

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

[0032] Figure 3 It 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 structural schematic 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 The enlarged 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] Fig. 9 It is a schematic diagram of the positioning axis of the present invention. Figure 1 ;

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

[0040] The attached drawings are marked with: 1. stirring barrel, 2. stirring motor, 3. upper cover, 4. positioning shaft, 5. stirring frame, 6. stirring shaft, 7. stirring paddle, 8. stirring blade, 9. scraper blade 1, 10. scraper blade 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 implementation methods of the present invention in detail with reference to the accompanying drawings and embodiments, 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 directional words, such as the terms "center", "lateral", "longitudinal", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", etc., indicating directions and positional relationships are based on the directions or positional relationships shown in the accompanying drawings, which are only for the convenience of narrating the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and cannot be understood as limiting the specific scope of protection of the present invention.

[0043] In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features. Therefore, the definition of "first" and "second" features can explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "several" is two or more, unless otherwise clearly and specifically defined.

[0044] In the present invention, unless otherwise specified and limited, the terms "assemble", "connect", and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can also be a mechanical connection; it can be directly connected, or it can be connected through an intermediate medium, or the two elements can be internally connected. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0045] It should be understood that when used in this specification and the appended claims, the terms "include" and "comprises" indicate the presence of described features, integers, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or combinations 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, unless the context clearly indicates otherwise, the singular forms of "a", "an" and "the" are intended to include plural forms.

[0047] Example 1

[0048] The present 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 be used 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; 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] The present 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] The present 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] The present 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, putting the modified epoxy resin emulsion and the polyamide resin into a special mixing device and mixing them evenly, heating them to 50-70° C. to react for 20-35 minutes, adding the modified nano rare earth, and mixing them at 80-100° C. for 20-35 minutes;

[0062] S5, adding 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 comprises the following steps:

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

[0066] S1.2. Put 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, the zirconium dioxide sol and the silicon dioxide sol is 1:1:3.

[0068] In this embodiment, specifically, the preparation method of the modified nano rare earth in S2 comprises 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 comprises 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 component; the stirring component 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 transmission, 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 is lifted up and down in the stirring barrel 1 to stir the material in the stirring barrel 1 up and down so that the material can be 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 stirring 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 matches the outer ring of the positioning shaft 4. A guide head 12 is arranged in the movable hole 13. A guide groove that matches the guide head 12 is arranged on the outer circumferential surface of the positioning shaft 4. 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 blade 9 is vertically arranged on the frame body, and the stirring blade 8 is horizontally arranged on the frame body. A scraper blade 2 10 is arranged on the side of the stirring blade 8 close to the stirring barrel 1.

[0079] In the above scheme, after the stirring motor is turned on, the stirring shaft and the stirring paddle drive the materials in the stirring barrel to stir. Under the action of the flowing materials, the stirring frame rotates with the materials. During the rotation of the stirring frame, the connecting head is driven to rotate. During the rotation of the connecting head, the guide head on the connecting head moves upward along the spiral rising groove, thereby driving the stirring paddle to move upward. When the guide head reaches the top of the spiral rising groove, the guide head enters the reset groove from the spiral rising groove and moves downward until it reaches the bottom of the spiral rising groove. The guide head rotates up and down and reciprocates in this way, thereby driving the stirring frame to move up and down while rotating, and the scraper blade one on the stirring frame rotates and scrapes the inner wall of the stirring barrel, and the scraper blade two scrapes the inner wall of the stirring barrel up and down, thereby effectively scraping off the material adhering to the inner wall of the stirring barrel. At the same time, the stirring blade on the stirring frame rotates and reciprocates up and down driven by the stirring frame, thereby improving the stirring effect of the material in the stirring barrel.

[0080] The above description is only for the best embodiment of the present invention, but it should not be understood as limiting the claims. The present invention is not limited to the above embodiments, and its specific structure is allowed to be changed. All changes made within the scope of protection of the independent claims of the present invention are within the scope of protection of the present invention.

Claims

1. A waterborne epoxy coating, characterized in that: The waterborne epoxy coating is prepared from 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.

2. A waterborne epoxy coating according to claim 1, characterized in that: The waterborne 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. A waterborne epoxy coating according to claim 1, characterized in that: The waterborne 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. A waterborne epoxy coating according to claim 1, characterized in that: The waterborne 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. A method for preparing a waterborne epoxy coating according to any one of claims 1 to 4, characterized in that: The preparation method comprises the following steps: S1, preparing modified sol; S2, preparing modified nano rare earth; S3, preparing modified epoxy resin emulsion; S4, putting the modified epoxy resin emulsion and the polyamide resin into a special mixing device and mixing them evenly, heating them to 50-70° C. to react for 20-35 minutes, adding the modified nano rare earth, and mixing them at 80-100° C. for 20-35 minutes; S5, adding 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.

6. The method for preparing a waterborne epoxy coating according to claim 5, characterized in that: 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. Put titanium dioxide sol, zirconium dioxide sol and silicon dioxide sol into a special mixing device and mix them evenly to obtain modified sol.

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

3.

8. The method for preparing a waterborne epoxy coating according to claim 5, characterized in that: 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.

9. The method for preparing a waterborne epoxy coating according to claim 5, characterized in that: 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.

10. The method for preparing a waterborne epoxy coating according to claim 5, characterized in that: 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 can be stirred more evenly.

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