A metal corrosion-resistant heat transfer protective film and its preparation method

Abstract

This invention relates to a heat transfer protective film for metal corrosion protection, comprising a heat-resistant layer coated on one side of a base film, and an adsorption layer, a strong anode layer, and a weak anode layer sequentially coated on the other side of the base film. Sacrificial anode cathodic protection is an effective method for metal corrosion protection, while heat transfer technology transfers graphic coded information onto a substrate using a heat transfer printer or similar method. Because the coating can be prepared in advance, it can form heat transfer protective films with multiple functions. By preparing an anode coating containing an active metal, coating it as a heat transfer protective film, and then transferring it onto a metal substrate, the sacrificial anode material protects the cathode metal while imparting graphic coded information to the metal substrate. This represents a new metal corrosion protection mode that adapts to the development of the information age.

Description

Technical Field

[0001] This invention belongs to the field of heat transfer film and metal corrosion protection technology, specifically relating to a heat transfer protective film for metal corrosion protection and its preparation method. Background Technology

[0002] Metallic materials are an important part of our social life, but approximately 30% of metallic materials are lost each year due to corrosion, severely affecting their performance. Metal corrosion is the phenomenon of material deterioration and damage caused by the chemical or electrochemical effects of the environmental medium. Currently, conventional corrosion prevention methods include metal surface treatment and electrochemical protection. Metal surface treatment requires overall treatment of the metal, which is cumbersome and costly; electrochemical protection requires additional anodic materials or protective current and is only used in specific situations. Currently, there is a lack of an efficient and convenient method for metal corrosion prevention.

[0003] Thermal transfer technology has seen rapid development in China recently. It allows for the pre-treatment of a coating onto a thin film, which is then used to transfer specific images and text onto a substrate via a thermal transfer printer. Because the coating can be prepared in advance, it can form multifunctional thermal transfer protective films. Combining thermal transfer technology with corrosion protection technology—applying a coating containing reactive metals to a thin film and then transferring it to a metal substrate via thermal transfer to act as the anode material—and using sacrificial anode cathodic protection for metal corrosion prevention, while simultaneously displaying images, text, and codes during the printing process, is particularly important in keeping pace with the era of ubiquitous digital technology.

[0004] Therefore, there is an urgent need to research and develop a heat transfer protective film for metal corrosion protection and its preparation method. Summary of the Invention

[0005] To overcome the problems in the prior art, the present invention aims to provide a heat transfer protective film for metal corrosion protection. This metal corrosion protective film provides a strong anode layer, a weak anode layer, and an adsorption layer suitable for heat transfer technology. Using equipment such as a heat transfer printer, a coating containing a reactive metallic material is transferred onto a metal substrate. The adsorption layer wets the three coating layers, forming a corrosion galvanic cell with the metal, thus sacrificing the anode to reduce metal corrosion. Simultaneously, it displays graphic codes and other information on the metal object.

[0006] The present invention also provides a method for preparing the above-mentioned heat transfer protective film for metal corrosion protection.

[0007] To achieve the above objectives, the technical solution of the present invention is as follows:

[0008] A heat transfer protective film for metal corrosion protection comprises a heat-resistant layer coated on one side of a base film, and an adsorption layer, a strong anode layer, and a weak anode layer sequentially coated on the other side of the base film. This heat transfer protective film transfers images onto the metal surface via heat transfer, forming a "metal-weak anode layer-strong anode layer-adsorption layer" structure. The adsorption layer adsorbs moisture from the air and covers the metal, thus protecting the metal object and reducing corrosion through sacrificial anode protection.

[0009] Specifically, the heat-resistant layer can be acrylic-modified silicone.

[0010] Furthermore, the base film can be a polyester film.

[0011] Specifically, the adsorption layer is composed of polyethylene wax, ethylene-vinyl acetate copolymer (EVA), and sodium polyacrylate in a weight ratio of 20-25:1-3:0.1-0.3. The polyethylene wax is a water-based and oil-based polyethylene wax with water-absorbing properties.

[0012] Furthermore, the strong anode layer is composed of epoxy resin, elastomer, aluminum powder, and carbon nanotubes in a weight ratio of 15-20:1-3:2-5:1-2.

[0013] Specifically, the elastomer is a type of rubber or rubber-like elastomer. The elastomer is preferably styrene-butadiene-styrene block copolymer (SBS). The carbon nanotubes are preferably single-walled carbon nanotubes.

[0014] Furthermore, the weak anode layer is composed of polyester resin, zinc powder, carbon nanotubes, and conductive pigments in a weight ratio of 18-25:2-5:1-2:2-3. The carbon nanotubes are preferably single-walled carbon nanotubes.

[0015] Specifically, the pigment can be black, red, green, etc., such as black conductive carbon black.

[0016] Furthermore, the thickness of the heat-resistant layer can be 0.06-0.1 μm; the thickness of the base film can be 5-10 μm; the thickness of the adsorption layer can be 1-3 μm; the thickness of the strong anode layer can be 2-5 μm; and the thickness of the weak anode layer can be 2-5 μm.

[0017] The present invention also provides a method for preparing the above-mentioned heat transfer protective film for metal corrosion protection, which includes the following steps:

[0018] a. Dilute the acrylic-modified silicone with methyl ethyl ketone solvent, coat it on one side of the base film, dry it to form a heat-resistant layer, and then proceed to the next process.

[0019] b. Weigh and mix the ethylene-vinyl acetate copolymer and sodium polyacrylate in the adsorption layer according to the proportion, dissolve them by heating with toluene (generally heating to 80-110℃), cool to room temperature, add polyethylene wax, transfer to a grinding device and grind for 1-2 hours, coat it to the other side of the base film through a coating screen roller and dry it to obtain the adsorption layer.

[0020] c. Weigh and mix the epoxy resin and elastomer in the strong anode layer according to the proportion, dissolve them with toluene by heating, cool to room temperature, add carbon nanotubes and aluminum powder, transfer to a grinding device and grind for 2-4 hours, coat it onto the adsorption layer through a coating screen roller and dry it to obtain the strong anode layer.

[0021] d. Weigh the polyester resin in the weak anode layer according to the proportion, dissolve it with toluene by heating, cool it to room temperature, add zinc powder, carbon nanotubes and conductive pigments, transfer it to a grinding device and grind for 2-4 hours, coat it onto the strong anode layer through a coating screen roller and dry it to obtain a heat transfer protective film for metal corrosion protection.

[0022] Sacrificial anode cathodic protection is an effective method for metal corrosion prevention, while thermal transfer technology transfers graphic coded information onto a substrate using a thermal transfer printer or similar method. Because the coating can be prepared in advance, it can form a multi-functional thermal transfer protective film. By preparing an anode coating containing an active metal, applying it as a thermal transfer protective film, and then transferring it onto a metal substrate, the sacrificial anode material protects the cathode metal while imparting graphic coded information to the metal substrate. This is a new metal corrosion prevention model that adapts to the development of the information age. The main technical breakthrough of this invention is the development of a novel thermal transfer protective film for metal corrosion prevention, exploring new application models combining metal corrosion prevention and thermal transfer technology. Compared with existing technologies, this invention has the following beneficial effects:

[0023] 1) The heat transfer protective film for metal corrosion protection of the present invention consists of five layers, namely a heat-resistant layer coated on one side of the base film, and an adsorption layer, a strong anode layer, and a weak anode layer coated on the other side of the base film in sequence. When transferred onto the metal substrate, it forms a structure of "metal-weak anode layer-strong anode layer-adsorption layer". The three coating layers form a corrosion cell with the metal through the wetting of the adsorption layer, and the sacrificial anode reduces metal corrosion.

[0024] 2) The adsorption layer of this invention is composed of water-based and oil-based polyethylene wax and sodium polyacrylate. The polyethylene wax helps the weak anode layer and strong anode layer of the heat transfer film to detach and transfer to the metal substrate. The sodium polyacrylate with strong moisture absorption capacity can adsorb moisture on the outermost layer. The combination of the two substances achieves good transfer performance and meets the conditions for forming a corrosion cell. This is the key innovation point of the integration of the two technologies.

[0025] 3) In this invention, the active metals in the weak anode layer and the strong anode layer are zinc and aluminum, respectively. After forming the "metal-weak anode layer-strong anode layer-adsorption layer" structure, the outermost zinc layer first corrodes to protect the cathode metal, with the weak anode layer separating it from the metal. After the zinc is consumed, the aluminum then corrodes to protect the metal. This step-by-step consumption of anode material avoids rapid failure of the single-layer structure after corrosion, extending the corrosion protection time. Simultaneously, the weak anode layer and the strong anode layer contain single-walled carbon nanotubes, which have excellent electrical conductivity and high tensile and flexural strength, resulting in good electrical conductivity within the coating and solving the conductivity problem of zinc and aluminum powders between resin coatings.

[0026] 4) This invention solves the homogeneity problem of zinc and aluminum powder in the coating by using selected polyester resin, acrylic resin, and elastomer. It also meets the heat transfer requirements of thermal transfer printing technology, avoiding the problem of transfer failure due to the presence of metal in the coating. This allows coatings containing anodic metal materials to solve metal corrosion problems while displaying graphics and coded information. Due to the flexibility of thermal transfer, the area of ​​graphics and coded information can be arbitrarily changed according to the size of the metal object, thereby adjusting the anodic metal material content and achieving a highly efficient and convenient metal corrosion protection effect. Detailed Implementation

[0027] The technical solution of the present invention will be further described in detail below with reference to the embodiments, but the scope of protection of the present invention is not limited thereto.

[0028] Unless otherwise specified, all raw materials used in the following embodiments are commercially available products that can be purchased directly. For example:

[0029] Acrylic-modified organosilicon was purchased from Longsheng Sihai New Materials Co., Ltd. (SH-1046).

[0030] The base film is a biaxially oriented polyester film, purchased from Jiaozuo Zhuoli Membrane Material Co., Ltd. (5-10 micrometer film).

[0031] Polyethylene wax was purchased from Longhai Chemical 2546B;

[0032] Ethylene-vinyl acetate copolymer (EVA) was purchased from Mitsui Chemicals 150;

[0033] Sodium polyacrylate was purchased from Jixin Yibang Biotechnology Co., Ltd. as ACUSOL 445n.

[0034] The epoxy resin was purchased from Nan Ya E51.

[0035] Styrene-butadiene-styrene block copolymer (SBS) was purchased from Kraton Group's G1652;

[0036] The polyester resin was purchased from Hanhai New Materials CL270;

[0037] The carbon nanotubes used were single-walled carbon nanotubes with a diameter of less than 1 nanometer, purchased from Occidental's TUBALLMATRIX 302.

[0038] The aluminum powder was purchased from Yingkou Hengda Extra Fine Aluminum Powder.

[0039] The zinc powder was purchased from Zhongke Xinnuote Fine Zinc Powder.

[0040] The conductive pigment was purchased from Eborui's conductive carbon black.

[0041] Room temperature refers to 25±5℃.

[0042] Example 1

[0043] A heat transfer protective film for metal corrosion protection comprises a heat-resistant layer coated on one side of a base film, and an adsorption layer, a strong anode layer, and a weak anode layer sequentially coated on the other side of the base film. The base film has a thickness of 5 μm.

[0044] The weight ratio and thickness of each raw material in the heat-resistant layer, adsorption layer, strong anode layer, and weak anode layer in the above scheme are shown in the table below.

[0045]

[0046] The above-mentioned method for preparing a heat transfer protective film for metal corrosion protection specifically includes the following steps:

[0047] a. Dilute the acrylic-modified silicone with methyl ethyl ketone solvent, coat it on one side of the base film, dry it at 110°C to form a heat-resistant layer, and then proceed to the next process.

[0048] b. Weigh and mix the ethylene-vinyl acetate copolymer (EVA) and sodium polyacrylate in the adsorption layer according to the proportion, dissolve them by heating to 80°C with toluene, cool to room temperature and add polyethylene wax, transfer to a grinding device and grind for 1.5 hours, coat it to the other side of the base film through a coating screen roller and dry it at 110°C to obtain the adsorption layer.

[0049] c. Weigh and mix the epoxy resin and elastomer (SBS) in the strong anode layer according to the proportion, dissolve them by heating to 80°C with toluene, cool to room temperature, add single-walled carbon nanotubes and aluminum powder, transfer to a grinding device and grind for 3 hours, coat it onto the adsorption layer through a coating screen roller and dry it at 110°C to obtain the strong anode layer.

[0050] d. Weigh the polyester resin in the weak anode layer according to the proportion, dissolve it by heating to 80°C with toluene, cool it to room temperature, add zinc powder, single-walled carbon nanotubes and conductive pigment carbon black, transfer it into a grinding device and grind for 3 hours, coat it onto the strong anode layer through a coating screen roller and dry it at 110°C to obtain a heat transfer protective film for metal corrosion protection.

[0051] The heat transfer protective film for metal corrosion protection produced in this case has the following effects:

[0052] Transfer 10cm 2 Heat transfer protective film for metal corrosion protection is printed up to 100cm. 2 Iron sheets were exposed to 70% humidity air, immersed in water, and immersed in a 3.5% sodium chloride solution for 3, 7, and 15 days, respectively, to observe rust marks (slight rust marks were defined as 1-5% of the rusted area, moderate rust marks as 6-20% of the rusted area, and severe rust marks as greater than 20% of the rusted area). Iron sheets without any heat transfer protective film imprints were placed as a control group. The results are shown in the table below.

[0053]

[0054] As can be seen from the table above, iron sheets with metal anti-corrosion heat transfer protective film imprints are less prone to rusting under different conditions compared to iron sheets without protective imprints, thus better protecting the metal from corrosion.

[0055] Example 2

[0056] A heat transfer protective film for metal corrosion protection comprises a heat-resistant layer coated on one side of a base film, and an adsorption layer, a strong anode layer, and a weak anode layer sequentially coated on the other side of the base film. The base film has a thickness of 5 μm. The weight ratio and thickness of the raw materials for the heat-resistant layer, adsorption layer, strong anode layer, and weak anode layer are shown in the table below.

[0057] The preparation method of the above-mentioned heat transfer protective film for metal corrosion protection is as described in Example 1.

[0058]

[0059] The heat transfer protective film for metal corrosion protection produced in this case has the following effects (the test method is the same as in Example 1).

[0060]

[0061]

[0062] Example 3

[0063] A heat transfer protective film for metal corrosion protection comprises a heat-resistant layer coated on one side of a base film, and an adsorption layer, a strong anode layer, and a weak anode layer sequentially coated on the other side of the base film. The base film has a thickness of 10 μm. The weight ratio and thickness of the raw materials for the heat-resistant layer, adsorption layer, strong anode layer, and weak anode layer are shown in the table below.

[0064] The preparation method of the above-mentioned heat transfer protective film for metal corrosion protection is as described in Example 1.

[0065]

[0066] The heat transfer protective film for metal corrosion protection produced in this case has the following effects (the test method is the same as in Example 1).

[0067]

[0068] Example 4

[0069] A heat transfer protective film for metal corrosion protection and its preparation method are disclosed, characterized in that it comprises a heat-resistant layer coated on one side of a base film, and an adsorption layer, a strong anode layer, and a weak anode layer sequentially coated on the other side of the base film. The base film has a thickness of 10 μm, and the weight ratio and thickness of each raw material in the heat-resistant layer, adsorption layer, strong anode layer, and weak anode layer are shown in the table below.

[0070] The preparation method of the above-mentioned heat transfer protective film for metal corrosion protection is as described in Example 1.

[0071]

[0072]

[0073] The heat transfer protective film for metal corrosion protection produced in this case has the following effects (the test method is the same as in Example 1).

[0074]

[0075] Example 5

[0076] A heat transfer protective film for metal corrosion protection comprises a heat-resistant layer coated on one side of a base film, and an adsorption layer, a strong anode layer, and a weak anode layer sequentially coated on the other side of the base film. The base film has a thickness of 10 μm. The weight ratio and thickness of the raw materials for the heat-resistant layer, adsorption layer, strong anode layer, and weak anode layer are shown in the table below.

[0077] The preparation method of the above-mentioned heat transfer protective film for metal corrosion protection is as described in Example 1.

[0078]

[0079] The heat transfer protective film for metal corrosion protection produced in this case has the following effects (the test method is the same as in Example 1).

[0080]

[0081]

Claims

1. A heat transfer protective film for metal corrosion protection, characterized in that, It consists of a heat-resistant layer coated on one side of the base film, and an adsorption layer, a strong anode layer, and a weak anode layer sequentially coated on the other side of the base film; The adsorption layer is composed of polyethylene wax, ethylene-vinyl acetate copolymer and sodium polyacrylate in a weight ratio of 20-25:1-3:0.1-0.

3. The strong anode layer is composed of epoxy resin, elastomer, aluminum powder, and carbon nanotubes in a weight ratio of 15-20:1-3:2-5:1-2. The weak anode layer is composed of polyester resin, zinc powder, carbon nanotubes, and conductive pigments in a weight ratio of 18-25:2-5:1-2:2-3.

2. The heat transfer protective film for metal corrosion protection as described in claim 1, characterized in that, The heat-resistant layer is made of acrylic-modified silicone.

3. The heat transfer protective film for metal corrosion protection as described in claim 1, characterized in that, The base film is a polyester film.

4. The heat transfer protective film for metal corrosion protection as described in claim 1, characterized in that, The elastomer is one of rubber or rubber-like elastomers.

5. The heat transfer protective film for metal corrosion protection as described in claim 1, characterized in that, The conductive pigment is conductive carbon black.

6. The heat transfer protective film for metal corrosion protection as described in claim 1, characterized in that, The thickness of the heat-resistant layer is 0.06-0.1μm; the thickness of the base film is 5-10μm; the thickness of the adsorption layer is 1-3μm; the thickness of the strong anode layer is 2-5μm; and the thickness of the weak anode layer is 2-5μm.

7. A method for preparing a heat transfer protective film for metal corrosion protection as described in any one of claims 1 to 6, characterized in that, Includes the following steps: a. Dilute the acrylic-modified silicone with methyl ethyl ketone solvent, coat it on one side of the base film, dry it to form a heat-resistant layer, and then proceed to the next process. b. Weigh and mix the ethylene-vinyl acetate copolymer and sodium polyacrylate in the adsorption layer according to the proportion, dissolve them with toluene by heating, cool to room temperature, add polyethylene wax, grind for 1-2 hours, coat to the other side of the base film and dry to obtain the adsorption layer. c. Weigh and mix the epoxy resin and elastomer in the strong anode layer together in proportion, heat with toluene until dissolved, cool to room temperature, add carbon nanotubes and aluminum powder, grind for 2-4 hours, coat onto the adsorption layer and dry to obtain the strong anode layer. d. Weigh the polyester resin in the weak anode layer according to the proportion, dissolve it with toluene by heating, cool it to room temperature, add zinc powder, carbon nanotubes and conductive pigments, grind for 2-4 hours, coat it onto the strong anode layer and dry it to obtain a heat transfer protective film for metal corrosion protection.

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