Preparation method of halogen-free casing coating

Abstract

The invention is applicable to the technical field of casing coatings, and particularly relates to a preparation method of a halogen-free casing coating, which comprises the following steps: mixing and stirring 10-30 parts of a modified resin solution, 10-25 parts of aluminum paste, 40-65 parts of thermoplastic resin, 5-20 parts of an organic solvent and 0.1-1 part of an auxiliary agent to obtain the halogen-free casing coating. According to the invention, the polymethyl methacrylate is used as modified resin to replace halogen-containing products such as vinyl chloride-vinyl acetate resin and vinyl chloride resin, so that the alcohol resistance is improved, and the polymethyl methacrylate is used to replace vinyl chloride-vinyl acetate resin and vinyl chloride resin, so that the alcohol resistance problem of the shell coating is solved, and the halogen-free requirement of the shell coating is met; the polymethyl methacrylate is convenient to purchase, can be purchased from regular resin companies or plastic particle companies on the market, can also be used after being purchased and crushed, and is low in cost.

Description

Technical Field

[0001] The invention belongs to the technical field of casing coatings, and in particular relates to a preparation method of halogen-free casing coatings. Background Art

[0002] With the strengthening of environmental protection awareness, European and American countries have imposed restrictions on products containing halogen elements (fluorine, chlorine, bromine, iodine, astatine), and issued a series of laws or industry regulations to control the content of halogen elements in electronic and electrical products, such as: Montreal Protocol, Stockholm Convention, EN regulations, IEC regulations and IPC regulations, etc. The introduction of these regulations or directives directly restricts the export of electronic and electrical products containing halogen elements, and indirectly restricts the use of compounds containing halogen elements. The substance used to improve alcohol resistance in casing coatings is chloride containing a large amount of chlorine.

[0003] In order to make the casing coating comply with halogen-free regulations or restrictions and have good alcohol resistance, coating technicians have made long-term and unremitting efforts. The main solutions are as follows: 1. Replace the original chlorine-containing resin with nitrocellulose. 2. Use imported high glass transition temperature resin. The existing technology has the disadvantages of too thin coating film, which leads to reduced alcohol resistance or high cost. Summary of the invention

[0004] The object of the present invention is to provide a halogen-free casing coating, aiming to solve the problem in the prior art that the coating film is too thin, resulting in reduced alcohol resistance or high cost.

[0005] The present invention is achieved by a method for preparing a halogen-free casing coating, the method comprising: mixing and stirring 10-30 parts of a modified resin solution, 10-25 parts of an aluminum silver paste, 40-65 parts of a thermoplastic resin, 5-20 parts of an organic solvent and 0.1-1 part of an auxiliary agent to obtain a halogen-free casing coating.

[0006] Preferably, the organic solvent is one of acetone, butanone, methyl acetate and ethyl acetate, or a mixture of two of them.

[0007] Preferably, the organic solvent is one or a mixture of two of toluene, xylene, trimethylbenzene, ethyl acetate, butyl acetate, methyl isoamyl ketone and propylene glycol methyl ether acetate.

[0008] Preferably, the thermoplastic resin is a thermoplastic acrylate resin.

[0009] Preferably, the modified resin is polymethyl methacrylate plastic particles.

[0010] Preferably, the materials for preparing the halogen-free housing coating include 10-30 parts of modified resin solution, 10-25 parts of aluminum silver paste, 40-65 parts of thermoplastic resin, 5-20 parts of organic solvent and 0.1-1 part of auxiliary agent.

[0011] Preferably, the materials for preparing the halogen-free housing coating include 18-22 parts of modified resin liquid, 16-20 parts of aluminum silver paste, 50-55 parts of thermoplastic resin, 10-15 parts of organic solvent and 0.2-0.5 parts of additive.

[0012] Preferably, the method comprises adding an organic solvent and an auxiliary agent into a stirring kettle in proportion, stirring evenly, adding aluminum silver paste, stirring evenly again, adding thermoplastic resin and modified resin liquid at the same time, stirring slowly for 30 minutes, filtering and packaging, and obtaining a halogen-free casing coating.

[0013] The preparation method of the halogen-free casing coating provided by the present invention adopts polymethyl methacrylate as a modified resin to replace chloroacetic acid resin, vinyl chloride resin and other halogen-containing products, thereby improving alcohol resistance. The use of polymethyl methacrylate to replace chloroacetic acid resin and vinyl chloride resin not only solves the alcohol resistance problem of the casing coating, but also meets the requirement that the casing coating is halogen-free. Polymethyl methacrylate is easy to purchase and can be purchased from regular resin companies or plastic particle companies on the market, or the materials produced by waste organic glass can be purchased and crushed for use, which is low in cost. DETAILED DESCRIPTION

[0014] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0015] In one embodiment of the present invention, a method for preparing a halogen-free casing coating comprises: mixing and stirring 10-30 parts of a modified resin solution, 10-25 parts of an aluminum silver paste, 40-65 parts of a thermoplastic resin, 5-20 parts of an organic solvent and 0.1-1 part of an additive to obtain a halogen-free casing coating.

[0016] In this embodiment, the modified resin and the organic solvent are continuously stirred in a stirring tank until the modified resin is completely dissolved to prepare a modified resin solution; the modified resin solution, aluminum silver paste, thermoplastic resin, organic solvent, and additives are mixed and stirred in a certain proportion to obtain the casing coating described in this scheme.

[0017] The proportions of the various components are: modified resin solution: 10-30 parts; aluminum silver paste: 10-25 parts; thermoplastic resin: 40-65 parts; organic solvent: 5-20 parts; auxiliary agent: 0.1-1 part.

[0018] Furthermore, the proportions of the components are: modified resin liquid: 18-22 parts; aluminum silver paste: 16-20 parts; thermoplastic resin: 50-55 parts; organic solvent: 10-15 parts; additive: 0.2-0.5 parts.

[0019] In this embodiment, the organic solvent is one of acetone, butanone, methyl acetate, and ethyl acetate, or a mixture of two of them.

[0020] In this embodiment, the organic solvent is one or a mixture of two of toluene, xylene, trimethylbenzene, ethyl acetate, butyl acetate, methyl isoamyl ketone, and propylene glycol methyl ether acetate.

[0021] In this embodiment, the auxiliary agent is: polyether modified silicone type leveling agent.

[0022] In this embodiment, the thermoplastic resin is a thermoplastic acrylic resin. The modified resin is polymethyl methacrylate (commonly known as organic glass) plastic particles, that is, organic glass plastic particles. They can be genuine polymethyl methacrylate plastic particles produced by petrochemical plants or plastic plants (for example, the product with the brand number 211 of Chi Mei Group in Taiwan, China), or they can be the product obtained by crushing waste organic glass.

[0023] In this embodiment, the preparation steps include adding an organic solvent and an auxiliary agent into a stirring kettle, stirring evenly, adding aluminum silver paste, stirring evenly again, and then adding thermoplastic resin and modified resin liquid at the same time, stirring slowly for 30 minutes, filtering and packaging, and thus obtaining a halogen-free high alcohol-resistant casing coating.

[0024] Embodiment 1,

[0025] Modified resin solution: 18

[0026] Thermoplastic resin: 55 (using 1201 resin from Yixing Sanmu Group)

[0027] Aluminum paste: 18 (commercially available)

[0028] Organic solvent: 8.5 (butyl acetate)

[0029] Additive: 0.5. (BYK306 additive is used)

[0030] The operation process is: first, add organic solvent and additives into the stirring kettle, start the motor, stir evenly, then add aluminum silver paste, stir evenly again, then add thermoplastic resin and modified resin solution at the same time, stir slowly for 30 minutes, filter and package, and you will get halogen-free high alcohol-resistant casing coating.

[0031] Embodiment 2,

[0032] Modified resin solution: 22

[0033] Thermoplastic resin: 51 (using 1201 resin from Yixing Sanmu Group)

[0034] Aluminum paste: 18 (commercially available)

[0035] Organic solvent: 8.5 (butyl acetate)

[0036] Additive: 0.5 (using BYK306 additive)

[0037] The operation process is: first, add organic solvent and additives into the stirring kettle, start the motor, stir evenly, then add aluminum silver paste, stir evenly again, then add thermoplastic resin and modified resin solution at the same time, stir slowly for 30 minutes, filter and package, and you will get halogen-free high alcohol-resistant casing coating.

[0038] Comparative Example 1: (Traditional halogen-containing technical solution)

[0039] Chlorovinyl resin solution: 22 (using 15 / 45M chlorovinyl resin from Wacker, Germany)

[0040] Thermoplastic resin: 51 (using 1201 resin from Yixing Sanmu Group)

[0041] Aluminum paste: 18 (commercially available)

[0042] Organic solvent: 8.5 (butyl acetate)

[0043] Additive: 0.5 (using BYK306 additive)

[0044] The operation process is: first, add organic solvent and additives into the stirring kettle, start the motor, stir evenly, then add aluminum silver paste, stir evenly again, then add thermoplastic resin and chloroacetic resin solution at the same time, stir slowly for 30 minutes, filter and package, and you will get the traditional high alcohol-resistant casing coating.

[0045] Comparative Example 2: (Halogen-free technical solution)

[0046] Nitrocellulose solution: 22 (using 1 / 2 second nitrocellulose)

[0047] Thermoplastic resin: 51 (using 1201 resin from Yixing Sanmu Group)

[0048] Aluminum paste: 18 (commercially available)

[0049] Organic solvent: 8.5 (butyl acetate)

[0050] Additive: 0.5 (using BYK306 additive)

[0051] The operation process is: first, add organic solvent and additives into the stirring kettle, start the motor, stir evenly, then add aluminum silver paste, stir evenly again, then add thermoplastic resin and nitrocellulose solution, stir slowly for 30 minutes, filter and package, and you will get halogen-free high alcohol-resistant casing coating.

[0052] Comparative Example 3: (Halogen-free technical solution)

[0053] Imported high glass transition temperature resin: 22 (using MB2952 resin from Mitsubishi Corporation of Japan)

[0054] Thermoplastic resin: 51 (using 1201 resin from Yixing Sanmu Group)

[0055] Aluminum paste: 18 (commercially available)

[0056] Organic solvent: 8.5 (butyl acetate)

[0057] Additive: 0.5 (using BYK306 additive)

[0058] The operation process is: first, add organic solvent and additives into the stirring kettle, start the motor, stir evenly, then add aluminum silver paste, stir evenly again, then add thermoplastic resin and imported high glass transition temperature resin at the same time, stir slowly for 30 minutes, filter and package, and you will get halogen-free high alcohol-resistant casing coating.

[0059] Take 20g samples of Comparative Examples 1, 2, 3 and Examples 1, 2 respectively, add 30g of diluent, dilute and stir evenly, spray on ABS plastic samples respectively, bake at 60 degrees for 1 hour, take out the samples, cool for 2 hours, and then test.

[0060] The testing instrument is a 500-gram alcohol tester.

[0061] Place the sample under the alcohol tester, start the instrument, wipe the sample until the coating is wiped off and the ABS plastic is exposed, and record the alcohol resistance wipe value on the tester. The larger the value, the better the alcohol resistance.

[0062] Comparative Example 1 Comparative Example 2 Comparative Example 3 Example 1 Example 2 Alcohol resistant wipe value 558 385 432 561 567

[0063] Performance evaluation 1: The alcohol wiping resistance of Example 1 and Example 2 is slightly better than that of Comparative Example 1, but compared with Comparative Example 1, the examples do not contain halogen.

[0064] Performance evaluation 2: The alcohol wiping performance of Example 1 and Example 2 is significantly better than that of Comparative Example 2 and Comparative Example 3. Although Comparative Example 2 and Comparative Example 3 also do not contain halogen, their alcohol wiping performance is significantly reduced.

[0065] The present invention utilizes the high alcohol resistance and halogen-free characteristics of polymethyl methacrylate, and dissolves polymethyl methacrylate plastic particles (organic glass particles) to form an alcohol-resistant modified resin for casing coating, which is halogen-free and ensures that the alcohol-resistant wiping performance is not lower than that of traditional alcohol-resistant casing coating. More importantly, the material source is broad and the price is low. Genuine polymethyl methacrylate plastic particles from petrochemical companies or plastic particle companies can be purchased and used, and discarded organic glass plastic products can be recycled, crushed and dissolved, and can also be used normally, thereby reducing the damage of discarded plastics to the environment.

[0066] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing a halogen-free casing coating, characterized in that: The method comprises: mixing and stirring 10-30 parts of a modified resin solution, 10-25 parts of an aluminum silver paste, 40-65 parts of a thermoplastic resin, 5-20 parts of an organic solvent and 0.1-1 part of an auxiliary agent to obtain a halogen-free housing coating.

2. The method for preparing the halogen-free casing coating according to claim 1, characterized in that: The organic solvent is one of acetone, butanone, methyl acetate and ethyl acetate, or a mixture of two of them.

3. The method for preparing the halogen-free casing coating according to claim 1, characterized in that: The organic solvent is one of toluene, xylene, trimethylbenzene, ethyl acetate, butyl acetate, methyl isoamyl ketone and propylene glycol methyl ether acetate, or a mixture of two of them.

4. The method for preparing the halogen-free casing coating according to claim 1, characterized in that: The thermoplastic resin is a thermoplastic acrylate resin.

5. The method for preparing the halogen-free casing coating according to claim 1, characterized in that: The modified resin is polymethyl methacrylate plastic particles.

6. The method for preparing the halogen-free casing coating according to claim 1, characterized in that: The materials for preparing the halogen-free housing coating include 10-30 parts of modified resin solution, 10-25 parts of aluminum silver paste, 40-65 parts of thermoplastic resin, 5-20 parts of organic solvent and 0.1-1 part of auxiliary agent.

7. The method for preparing the halogen-free casing coating according to claim 1, characterized in that: The materials for preparing the halogen-free housing coating include 18-22 parts of modified resin liquid, 16-20 parts of aluminum silver paste, 50-55 parts of thermoplastic resin, 10-15 parts of organic solvent and 0.2-0.5 parts of auxiliary agent.

8. The method for preparing the halogen-free casing coating according to any one of claims 1, 6 and 7, characterized in that: The method comprises adding an organic solvent and an auxiliary agent into a stirring kettle in proportion, stirring evenly, adding aluminum silver paste, stirring evenly again, adding thermoplastic resin and modified resin liquid at the same time, stirring slowly for 30 minutes, filtering and packaging to obtain a halogen-free casing coating.