Liquid plastic base film and preparation method thereof

Abstract

The invention discloses a liquid plastic base film and a preparation method thereof, belongs to the technical field of materials, and is used for solving the problem of developing a green and environment-friendly liquid plastic base film with excellent performance. The model of the liquid-plastic base film is DX-936S, the liquid-plastic base film is composed of a composite water-based high-molecular polymer dispersion, and the composite water-based high-molecular polymer dispersion is prepared from the following raw materials: 20-40 parts of water-based acrylic resin, 15-30 parts of water-based polyurethane resin, 7.5-15 parts of nano silicon dioxide, 4-8 parts of a plasticizer, 2.5-5 parts of a dispersing agent and 1-2 parts of a defoaming agent. The product is in a liquid state before being brushed, forms a solid film after being brushed, is suitable for protecting surfaces in various shapes, and is convenient to clean. The product is low in VOC, non-toxic, harmless, green and environment-friendly, and does not generate the defects of shrinkage cavities and the like in the coating process. The coating has excellent chemical resistance, flexibility, water resistance, scratch resistance, oil resistance, corrosion resistance, weather resistance and the like. The adhesive tape is suitable for most of different types of base materials, and can be easily peeled off from the base materials without any trace.

Description

Technical Field

[0001] The present invention belongs to the technical field of materials. Specifically, it is a liquid-plastic base film composed of a composite aqueous polymer dispersion and having a variety of excellent properties and wide applications, as well as a preparation method thereof. Background Art

[0002] Currently, in various industrial production and product protection fields, the demand for surface protective films is increasing day by day. Traditional protective films have many deficiencies in performance. For example, some protective films have poor chemical resistance and are easily damaged after contacting some chemical substances; some have poor flexibility and cannot adapt to the protection of various shaped surfaces; and some are prone to defects such as shrinkage holes during the coating process, affecting the appearance and quality of products. At the same time, some protective films also have environmental problems, such as containing high levels of VOCs, which are harmful to the environment and human health.

[0003] Therefore, it is of great practical significance to develop a liquid-plastic base film with excellent performance and environmental friendliness. Summary of the Invention

[0004] The purpose of the present invention is to provide a liquid-plastic base film to solve the deficiencies of existing protective films in terms of performance and environmental protection and meet the requirements of modern production for surface protection materials.

[0005] To achieve the above technical purpose, the technical solution adopted by the present invention is as follows:

[0006] A liquid-plastic base film, which is composed of a composite aqueous polymer dispersion. The composite aqueous polymer dispersion includes the following raw materials: 20 - 40 parts of aqueous acrylic resin, 15 - 30 parts of aqueous polyurethane resin, 7.5 - 15 parts of nano-silica, 4 - 8 parts of plasticizer, 2.5 - 5 parts of dispersant, and 1 - 2 parts of defoamer. It is in a liquid state before brushing and forms a solid film after brushing. The liquid-plastic base film produced using the above raw materials has the model DX-936S.

[0007] Compared with the prior art, the liquid-plastic base film product of the present invention is a new generation of liquid-plastic base film composed of a novel special composite aqueous polymer dispersion, and is an ideal product that cannot be replaced in modern production. It is in a liquid state before brushing and forms a solid film after brushing, suitable for the protection of various shaped surfaces and easy to clean. This product has low VOCs, is non-toxic and harmless, environmentally friendly, and does not produce defects such as shrinkage holes during the coating process. It has excellent chemical resistance, flexibility, water resistance, scratch resistance, oil resistance, corrosion resistance, weather resistance and other properties. It is applicable to the vast majority of different types of substrates and can be easily peeled off from the substrate without leaving traces. The liquid-plastic base film product is commonly used in coating workshops and used as a substrate in combination with medium- and low-temperature dust-removing products. Detailed Embodiment

[0008] To enable those skilled in the art to better understand the present invention, the technical solution of the present invention will be further described below in conjunction with embodiments.

[0009] A liquid-plastic base film, which is composed of a composite aqueous polymer dispersion. The composite aqueous polymer dispersion includes 20-40 parts of aqueous acrylic resin, 15-30 parts of aqueous polyurethane resin, 7.5-15 parts of nano-silica, 4-8 parts of plasticizer, 2.5-5 parts of dispersant, and 1-2 parts of defoamer.

[0010] The aqueous acrylic resin, aqueous polyurethane resin, nano-silica, plasticizer, dispersant, and defoamer are composed in the following ratio: 40:30:15:8:5:2.

[0011] It is in a liquid state before brushing and forms a solid film after brushing.

[0012] The working temperature range is 5-80°C.

[0013] No shrinkage holes will be generated during the coating process.

[0014] The present invention also discloses a method for preparing a liquid-plastic base film, which includes the following steps:

[0015] Step 1, raw material preparation. According to the formula, weigh each component and take 20-40 parts of aqueous acrylic resin, 15-30 parts of aqueous polyurethane resin, 7.5-15 parts of nano-silica, 4-8 parts of plasticizer, 2.5-5 parts of dispersant, and 1-2 parts of defoamer. Among them, the aqueous acrylic resin is one of the main components for forming the base film, endowing the base film with good film-forming properties, water resistance, and chemical resistance. The aqueous polyurethane resin can enhance the flexibility and wear resistance of the base film. Nano-silica is indispensable and can significantly improve the hardness, scratch resistance, and weather resistance of the base film.

[0016] Step 2, pre-stirring stage. Add the weighed aqueous acrylic resin and aqueous polyurethane resin into a container with a stirring device, select the stirring speed, start stirring at 200-400 revolutions per minute, and continue for 10-15 minutes to reach the pre-fusion state of the two resins. Among them, the pre-fusion state means that the two resins are gradually and evenly mixed, and the fluidity and appearance of the liquid gradually tend to be consistent. The purpose of this stage is to initially mix the two main resins and make them fuse with each other, laying a foundation for adding other components later.

[0017] Step 3: Addition and stirring. After the pre-stirring is completed, slowly add nano-silica. Nano-silica has a small particle size and a large specific surface area, and it is easy to agglomerate. Therefore, after adding it, the stirring speed needs to be increased to 400 - 600 revolutions per minute and stirred for 20 - 30 minutes. High-speed stirring can effectively break the agglomerates of nano-silica and make it evenly dispersed in the resin system. During this process, as the stirring progresses, the viscosity of the mixed liquid will slightly increase, and the appearance will become more delicate and uniform.

[0018] Step 4: Addition and stirring of the remaining components. Add the plasticizer, dispersant, and defoamer in sequence, and keep the stirring speed at 300 - 500 revolutions per minute and continue stirring for 30 - 60 minutes to make all components fully mixed and uniform. The temperature is controlled at 20 - 30 °C and the relative humidity is 40% - 60% during the entire preparation process. Among them, the defoamer can prevent the generation of bubbles and shrinkage holes during the preparation and application processes to ensure the stability of the product quality.

[0019] In the preferred solution, in Step 2, the pre-stirring stage, in the pre-fusion state, a stirring container made of stainless steel is selected, which has good corrosion resistance and can avoid chemical reactions with the resin. The size of the container needs to be reasonably selected according to the preparation volume to ensure that the resin has enough space to move in the container, which is conducive to stirring and mixing. At the same time, a stirring device with high precision and good stability is equipped, and a stirrer with a variable-frequency speed-regulating motor is used to accurately control the stirring speed. Among them, a paddle-type stirring paddle is used, which can promote the liquid circulation during stirring and prompt the preliminary mixing of the resin. The paddle-type stirring paddle operates at a low speed.

[0020] Step 2: Pre-stirring stage, in the pre-fusion state, slowly pour the waterborne acrylic resin into the stirring container, pour it evenly along the container wall, and avoid concentrating in one place, which may cause uneven local mixing. Subsequently, add the waterborne polyurethane resin in the same way. The addition processes of the two resins should be kept stable and continuous to prevent large impacts and affect the mixing effect.

[0021] Step 2: Pre-stirring stage, in the pre-fusion state, after adding the two resins, start stirring at a speed of 200 - 400 revolutions per minute. The lower starting speed can prevent excessive bubbles from being generated due to too fast stirring, and at the same time, it can also allow the two resins to come into initial contact and penetrate each other. In the first 5 minutes of stirring, closely observe the flow state and mixing situation of the resin. As the stirring progresses, it can gradually be seen that the two resins, which were originally relatively distinct, begin to interpenetrate and blend with each other. After 5 minutes, according to the actual state of the mixed liquid, increase the speed to 300 - 400 revolutions per minute to accelerate the diffusion and collision between molecules and further promote the fusion. Stir at this speed for 5 - 10 minutes, and the fluidity of the mixed liquid gradually becomes more uniform, and the originally existing local concentration differences gradually decrease. Table 1 shows the physical and chemical properties of this product.

[0022]

[0023] Table 1

[0024] Example 1

[0025] It is composed of waterborne acrylic resin, waterborne polyurethane resin, nano-silica, plasticizer, dispersant, and defoamer in the following ratio: 40:30:15:8:5:2. Through the above stirring process, it is fully mixed evenly to obtain the raw material of the liquid-plastic base film. The raw material is brushed on the surface of the metal substrate at a temperature of 25°C, and the brushing thickness is 0.1 mm. After brushing, it is naturally dried at room temperature to form a solid film. After testing, the VOC content of this liquid-plastic base film is extremely low, meeting the environmental protection standards. Performance tests are carried out in the temperature range of 5 - 80°C, and its chemical resistance, flexibility, water resistance, scratch resistance, oil resistance, corrosion resistance, and weather resistance all perform well. It can be peeled off from the metal substrate without leaving any traces.

[0026] The liquid-plastic base film of the present invention is composed of a novel special composite waterborne polymer dispersion, with the characteristics of low VOC, non-toxic, harmless, and green environmental protection, meeting the modern environmental protection concept, and being beneficial to the health of workers and environmental protection. Among them, waterborne acrylic resin and waterborne polyurethane resin provide good film-forming property, flexibility, and chemical resistance; nano-silica enhances the hardness, wear resistance, and weather resistance of the film; the plasticizer improves the flexibility of the film; the dispersant ensures the uniform dispersion of each component; the defoamer reduces the generation of bubbles and shrinkage holes during the coating process.

[0027] Its working temperature range is 5 - 80°C, and it can be stably applied within a relatively wide temperature range, expanding the usage scenarios.

[0028] Excellent chemical resistance, flexibility, water resistance, scratch resistance, oil resistance, corrosion resistance, and weather resistance make it suitable for surface protection of various complex environments and different types of substrates, improving the service life and quality of the product.

[0029] The characteristics of being liquid before brushing and solid after brushing are convenient for construction, can adapt to the protection of various shaped surfaces, and are easy to clean. At the same time, it is easy to peel off from the substrate without leaving any traces, facilitating the removal of the protective film when needed without affecting the substrate itself. When used as a substrate in the coating workshop in cooperation with medium- and low-temperature dust-removing products, its application value in industrial production is further enhanced. The above has introduced in detail the liquid-plastic base film and the preparation method of the liquid-plastic base film provided by the present invention. The description of specific embodiments is only used to help understand the method of the present invention and its core idea. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and modifications can be made to the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims

1. Liquid-plastic base film, characterized in that: The liquid-plastic base film is composed of a composite aqueous polymer dispersion, and the composite aqueous polymer dispersion includes the following raw materials: 20-40 parts of aqueous acrylic resin, 15-30 parts of aqueous polyurethane resin, 7.5-15 parts of nano-silica, 4-8 parts of plasticizer, 2.5-5 parts of dispersant, and 1-2 parts of defoamer.

2. The liquid-plastic base film according to claim 1, characterized in that: It is in a liquid state before brushing and forms a solid film after brushing.

3. The liquid-plastic base film according to claim 2, wherein: The working temperature range is 5-80 °C.

4. The liquid-plastic base film according to claim 3, characterized in that: No shrinkage holes will be generated during the painting process.

5. The method for preparing the liquid-plastic base film according to claim 4, characterized in that: It includes the following steps: Step 1, raw material preparation: According to the formula, weigh each component and take 20-40 parts of aqueous acrylic resin, 15-30 parts of aqueous polyurethane resin, 7.5-15 parts of nano-silica, 4-8 parts of plasticizer, 2.5-5 parts of dispersant, and 1-2 parts of defoamer. Step 2, pre-stirring stage: Add the weighed aqueous acrylic resin and aqueous polyurethane resin into a container with a stirring device, select the stirring speed, start stirring at 200-400 revolutions per minute, and continue for 10-15 minutes to reach the pre-fusion state of the two resins. Step 3, addition and stirring: After the pre-stirring is completed, add nano-silica. Nano-silica has a small particle size and a large specific surface area, and is easy to agglomerate. After adding, the stirring speed needs to be increased to 400-600 revolutions per minute and stirred for 20-30 minutes. High-speed stirring can effectively break the agglomerates of nano-silica and make it evenly dispersed in the resin system. Step 4, addition and stirring of the remaining components: Add the plasticizer, dispersant, and defoamer in sequence, keep the stirring speed at 300-500 revolutions per minute, and continue stirring for 30-60 minutes to make all components fully mixed evenly. The temperature is controlled at 20-30 °C and the relative humidity is 40%-60% during the whole preparation process. Among them, the defoamer can prevent the generation of bubbles and shrinkage holes during the preparation and application process.

6. The method for preparing the liquid-plastic base film according to claim 5, characterized in that: Step 2, pre-stirring stage: In the pre-fusion state, select a stirring container made of stainless steel and a stirrer with a variable-frequency speed-regulating motor to control the stirring speed.

7. The method for preparing the liquid-plastic base film according to claim 6, characterized in that: Step 2, pre-stirring stage: In the pre-fusion state, use a paddle-type stirring paddle, which can push the liquid to circulate during stirring and promote the preliminary mixing of the resins.

8. The method for preparing a liquid-plastic base film according to claim 7, characterized in that: Step 2, pre-stirring stage: In the pre-fusion state, slowly pour the aqueous acrylic resin into the stirring container, pour it evenly along the container wall to avoid concentration in one place resulting in uneven local mixing, and then add the aqueous polyurethane resin in the same way.

9. The method for preparing the liquid-plastic base film according to claim 8, wherein: Step 2, pre-stirring stage: In the pre-fusion state, start stirring at a speed of 200-400 revolutions per minute after adding the two resins; closely observe the flow state and mixing situation of the resins in the first 5 minutes of stirring; after 5 minutes, increase the speed to 300-400 revolutions per minute according to the actual state of the mixed liquid to accelerate the diffusion and collision between molecules and further promote fusion.

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