Electronic process die-cutting co-extrusion protective film and preparation method thereof

Abstract

The invention discloses an electronic process die-cutting co-extrusion protective film, and relates to the technical field of protective films, the electronic process die-cutting co-extrusion protective film comprises a blown film outer layer, a blown film middle layer and a blown film inner layer, the blown film outer layer comprises 50-70 parts of a hydrogenated styrene block copolymer A, 20-50 parts of a hydrogenated styrene block copolymer B and 5-20 parts of polypropylene; the blown film middle layer comprises 20-50 parts of low-density polyethylene, 20-50 parts of linear low-density polyethylene and 20-40 parts of polypropylene; the film blowing inner layer comprises 20-30 parts of low-density polyethylene, 20-40 parts of high-density polyethylene and 20-40 parts of polypropylene; wherein the ratio of the blown film outer layer is 10-20%, the ratio of the blown film middle layer is 40-60%, and the ratio of the blown film inner layer is 40-60%. The invention further discloses a preparation method of the electronic process die-cutting co-extrusion protective film. The coating has good stability and aging resistance, has good chemical stability, and can resist erosion of various chemical substances; and the reject ratio caused by pause marks generated by the capacity during film tearing is reduced, the material transferring time during production is shortened, and the loss and the production cost are reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of protective films, and more specifically, to an electronic manufacturing die-cut co-extruded protective film and a preparation method thereof. Background Art

[0002] With the continuous rapid development of the electronics industry, especially the continuous expansion of the scope of consumer electronic products, die-cutting is not only limited to the later stage of printed products, but also a production of auxiliary materials for industrial electronic products. Commonly used products are applied to: electroacoustics, healthcare, display signs, safety protection, transportation, office supplies, electronic power, communication, industrial manufacturing, and home leisure industries. They are used in mobile phones, MIDs, digital cameras, automobiles, LCDs, LEDs, FPCs, FFCs, and RFID products, and are gradually used for the bonding, dust prevention, shock absorption, insulation, and shielding heat conduction protection of the above products. The die-cutting materials used for processing include rubber, single-sided and double-sided tapes, foams, plastics, vinyls, silicones, metal tapes, metal foils, optical films, protective films, wire meshes, hot melt tapes, and silicones.

[0003] Diffusion sheets are made by coating a uniform resin and a light diffusion material on a PET substrate, and then using a PC with a rough surface to obtain a uniformly concave-convex rough diffusion surface by thermal transfer. Due to the special surface of the diffusion sheet, a coated acrylic adhesive product with a higher adhesive force needs to be used for bonding and protection. However, after the coated adhesive product is bonded, the adhesive force increases greatly, and it is easy to produce a pause mark when tearing the film, resulting in a high defective rate. Another type is a common transparent medium-high viscosity co-extruded film, in which the inner layer uses pure high-pressure polyethylene. When cutting, it is difficult to cut off due to its large toughness, and there will be an adhesion problem between the sheets after stacking. At present, the protection of diffusion sheets mostly uses co-extruded protective films produced by the casting process. During production, the material transfer time is long, the viscosity is single and the loss is large, and the production cost is high. In view of this, we propose an electronic manufacturing die-cut co-extruded protective film and a preparation method thereof. Summary of the Invention

[0004] To solve the above technical problems, an electronic manufacturing die-cut co-extruded protective film and a preparation method thereof are provided. The present technical solution solves the problem of high production cost mentioned above.

[0005] To achieve the above object, the technical solution adopted by the present invention is: an electronic manufacturing die-cut co-extruded protective film, comprising: a blown film outer layer, a blown film middle layer, and a blown film inner layer, wherein the blown film outer layer comprises 50-70 parts of a hydrogenated styrene block copolymer A, 20-50 parts of a hydrogenated styrene block copolymer B, and 5-20 parts of polypropylene;

[0006] The blown film middle layer comprises 20-50 parts of low-density polyethylene, 20-50 parts of linear low-density polyethylene, and 20-40 parts of polypropylene;

[0007] The inner layer of the blown film comprises 20-30 parts of low-density polyethylene, 20-40 parts of high-density polyethylene and 20-40 parts of polypropylene;

[0008] Among them, the proportion of the outer layer of the blown film is 10-20%, the proportion of the middle layer of the blown film is 40-60%, and the proportion of the inner layer of the blown film is 40-60%.

[0009] Preferably, the hydrogenated styrene block copolymer A does not contain unsaturated double bonds, and the processing temperature is 195-210 °C. The hydrogenated styrene block copolymer A includes one or more of Asahi Kasei S1606, Asahi Kasei H1221, Kraton 6700, Kraton 1645 and Kraton 1652; the hydrogenated styrene block copolymer A includes styrene, conjugated diene and hydrogenating agent.

[0010] Preferably, the hydrogenated styrene block copolymer B does not contain unsaturated double bonds, and the processing temperature is 175-200 °C. The hydrogenated styrene block copolymer B includes one or more of Asahi Kasei L613, Asahi Kasei H1521, Kraton 1646, Kraton 6666 and Kraton 1643; the hydrogenated styrene block copolymer B includes styrene, conjugated diene and hydrogenating agent.

[0011] Preferably, the density of the polypropylene is 0.91 g / cm 3 , and the polypropylene in the outer layer of the blown film includes one or more of SK B310F, RP242G, and Cosmoplene W331; the polypropylene in the middle layer and the inner layer of the blown film includes one or more of SK R520Y, R701, J640, and T30S; the polypropylene is one of homopolypropylene and copolymerized polypropylene.

[0012] Preferably, the low-density polyethylene is one of autoclave-process low-density polyethylene and high-pressure tubular-process low-density polyethylene; the linear low-density polyethylene is one of butene copolymerized polyethylene, ethylene copolymerized polyethylene and octene copolymerized polyethylene.

[0013] A preparation method of an electronic process die-cut co-extruded protective film, and the preparation steps are as follows:

[0014] S1. Prepare materials, including: the outer layer of the blown film, the middle layer of the blown film and the inner layer of the blown film. By calculating the dosage of each layer of raw materials, automatically weigh the materials and stir evenly;

[0015] S2. Melt processing, put the evenly stirred raw materials into a single-screw extrusion device respectively. The processing temperature of the outer layer of the blown film is controlled at 185-210 °C, and the processing temperatures of the middle layer and the inner layer of the blown film are controlled at 195-210 °C. Melt the raw materials, and the melted materials are driven by the screw to different areas for shear separation processing;

[0016] S3. Filter impurities. Use a stack filter with a precision of 20 μm to filter the melt in the three-layer screw, removing impurities and crystal points.

[0017] S4. Die forming. The three-layer melt flows into the die respectively. The die temperature is controlled at 185 - 205 °C from bottom to top. Adjust the air volume and the traction wire speed according to the set specifications to make the melt expand and form a film bubble.

[0018] S5. Cooling and shaping. Cool the film bubble to obtain a stable film bubble.

[0019] S6. Flattening and winding. The cooled film bubble is flattened by a chevron clip, multiple anti-sticking guide rollers and tension control guide rollers, and then wound.

[0020] S7. Slitting into finished products. According to the usage specifications, slit the wound film into the corresponding width to finally obtain the protective film.

[0021] Preferably, in step S1, the weighed materials are respectively added into the temperature-controlled heating screws of the outer layer, middle layer and inner layer of the blown film, and separated scissors mixing processing is carried out for 5 - 10 min, and the rotation speed of the screw motor is 40 - 50 r / min.

[0022] Preferably, in step S5, cooling is carried out through an air control automatic air ring, the wind speed is 5 - 10 m / s, and the flow rate is 10 - 100 m 3 / min.

[0023] Preferably, in step S6, in the winding step, the film bubble is extruded by a clamping plate to initially unfold the film surface, and an anti-sticking guide roller is used for leveling treatment. Through the monitoring and control system of the sensor, a constant tension is maintained during the winding process.

[0024] Preferably, in step S7, in the slitting step, the film is guided to the cutter by a guide roller, and the tension control system is used to keep the film under tension during slitting. The cutting quality is monitored in real time and dimensional inspection is carried out. The slit film strips are guided to the winding device, and the winding tension is adjusted to make the film roll tight and neat.

[0025] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0026] The present invention adopts a three-layer co-extrusion structure, uses polyethylene and polypropylene as raw materials for the middle layer and the matte layer, and uses a modified thermoplastic elastomer for the adhesive layer. The protective film made by co-extruding the three-layer materials through heating, melting, shearing and plasticizing by a co-extrusion system and then through a die head and a forming die using a three-layer blown film process has good stability and aging resistance, has good chemical stability, and can resist the erosion of various chemical substances; reduces the defect rate caused by the pause marks generated during film tearing, reduces the long material transfer time during production, and reduces losses and production costs. Description of the Drawings

[0027] Figure 1 This is a schematic diagram of the preparation steps of the present invention. Specific embodiments

[0028] The following description is used to disclose the present invention so that those skilled in the art can implement the present invention. The preferred embodiments in the following description are only examples, and other obvious variations can be conceived by those skilled in the art.

[0029] Referring to Figure 1 As shown, an electronic manufacturing die-cut co-extruded protective film includes: a blown film outer layer, a blown film middle layer, and a blown film inner layer. The blown film outer layer includes 50-70 parts of a hydrogenated styrene block copolymer A, 20-50 parts of a hydrogenated styrene block copolymer B, and 5-20 parts of polypropylene;

[0030] The blown film middle layer includes 20-50 parts of low-density polyethylene, 20-50 parts of linear low-density polyethylene, and 20-40 parts of polypropylene;

[0031] The blown film inner layer includes 20-30 parts of low-density polyethylene, 20-40 parts of high-density polyethylene, and 20-40 parts of polypropylene;

[0032] Among them, the proportion of the blown film outer layer is 10-20%, the proportion of the blown film middle layer is 40-60%, and the proportion of the blown film inner layer is 40-60%.

[0033] The polyethylene in this application has good flexibility, impact resistance, and chemical corrosion resistance, while polypropylene has higher rigidity, hardness, and heat resistance. The combination of the two as the middle layer endows the protective film with the characteristics of both rigidity and flexibility, enabling it to withstand a certain amount of external force impact and stretching without being easily broken or deformed, providing a solid structural support for the entire protective film. The modified thermoplastic elastomer has good elasticity and adhesiveness, can closely adhere to the surface of the object to be protected, and can undergo a certain amount of elastic deformation when subjected to external forces, absorbing and dispersing energy, further enhancing the impact resistance and tear resistance of the protective film;

[0034] The matte layer formed by polypropylene has a low gloss and a soft visual effect, which not only makes the appearance of the protective film more beautiful, but also effectively reduces light reflection and the irritation to the human eye. In addition, the matte surface can also prevent scratches and fingerprints on the surface of the object to be protected to a certain extent, playing a better role in protection and decoration;

[0035] The modified thermoplastic elastomer of the adhesive layer can provide appropriate adhesiveness, which can firmly adhere to the surface of the object to be protected, preventing the protective film from falling off during use, and can be easily peeled off when removal is required, without leaving residual glue and causing no damage to the surface of the object to be protected;

[0036] Polyethylene and polypropylene themselves have good chemical stability and can resist the erosion of various chemicals, such as acids, alkalis, and organic solvents. This enables the protective film to maintain stable performance in different chemical environments and extends its service life.

[0037] It has a certain tolerance to environmental factors such as ultraviolet rays, oxygen, and moisture. When used in outdoor environments, it will not age, discolor, or become brittle due to long-term exposure to sunlight, and can maintain good physical properties and appearance quality.

[0038] By using a coextrusion system and a three-layer blown film process, three different materials can be processed into a protective film with a three-layer structure at one time, avoiding the cumbersome processes of multiple processing and lamination. This greatly improves production efficiency and reduces production costs. During the coextrusion process, by precisely controlling process parameters such as the temperature, pressure, and extrusion speed of each layer of material, precise control of the thickness and performance of each layer can be achieved, thereby producing protective film products that meet the needs of different customers and application scenarios. The coextrusion process can enable the materials of each layer to be fully mixed and combined in a molten state, reducing material waste, improving material utilization rate, and reducing production costs.

[0039] Hydrogenated styrene block copolymer A does not contain unsaturated double bonds, and its processing temperature is 195 - 210 °C. Hydrogenated styrene block copolymer A includes one or more of Asahi Kasei S1606, Asahi Kasei H1221, Kraton 6700, Kraton 1645, and Kraton 1652; Hydrogenated styrene block copolymer A includes styrene, conjugated diene, and a hydrogenating agent.

[0040] Hydrogenated styrene block copolymer B does not contain unsaturated double bonds, and its processing temperature is 175 - 200 °C. Hydrogenated styrene block copolymer B includes one or more of Asahi Kasei L613, Asahi Kasei H1521, Kraton 1646, Kraton 6666, and Kraton 1643; Hydrogenated styrene block copolymer B includes styrene, conjugated diene, and a hydrogenating agent.

[0041] The density of polypropylene is 0.91 g / cm 3 , and the polypropylene in the outer layer of the blown film includes one or more of SK B310F, RP242G, and Cosmoplene W331; the polypropylene in the middle layer and the inner layer of the blown film includes one or more of SK R520Y, R701, J640, and T30S; Polypropylene is one of homopolypropylene and copolymerized polypropylene.

[0042] Low-density polyethylene is one of autoclave-process low-density polyethylene and tubular-process high-pressure low-density polyethylene; Linear low-density polyethylene is one of butene copolymerized polyethylene, ethylene copolymerized polyethylene, and octene copolymerized polyethylene.

[0043] A preparation method of an electronic process die-cut co-extrusion protective film, and the preparation steps are as follows:

[0044] S1. Prepare materials, including: the outer blown film layer, the middle blown film layer and the inner blown film layer. By calculating the raw material dosage of each layer, automatically weigh the materials and stir them evenly;

[0045] S2. Melt processing: Put the evenly stirred raw materials into a single-screw extrusion device respectively. The processing temperature of the outer blown film layer is controlled at 185 - 210 °C, and the processing temperatures of the middle blown film layer and the inner blown film layer are controlled at 195 - 210 °C. Melt the raw materials, and the melted materials are driven by the screw to different areas for shear separation processing;

[0046] S3. Filter impurities: Use a stacked plate filter with a precision of 20 μm to filter the melt in the three-layer screw to remove impurities and crystal points;

[0047] S4. Die head forming: The three-layer melt flows into the die head respectively. The die head temperature is controlled at 185 - 205 °C from bottom to top. Adjust the air volume and the traction wire speed according to the set specifications to make the melt blow up to form a film bubble;

[0048] S5. Cooling and shaping: Cool the film bubble to obtain a stable film bubble;

[0049] S6. Flattening and winding: The cooled film bubble is flattened by a herringbone clip, multiple anti-sticking guide rollers and a tension control guide roller, and then wound;

[0050] S7. Slitting into finished products: According to the usage specifications, slit the wound film into corresponding widths to finally obtain the protective film.

[0051] In step S1, the weighed materials are respectively added into the temperature-controlled heating screws of the outer blown film layer, the middle blown film layer and the inner blown film layer for separation scissor mixing processing for 5 - 10 minutes, and the screw motor speed is 40 - 50 r / min.

[0052] In step S5, the cooling is carried out by a wind control automatic air ring, the wind speed is 5 - 10 m / s, and the flow rate is 10 - 100 m 3 / min.

[0053] In step S6, in the winding step, the film bubble is extruded by a clamping plate to initially unfold the film surface, and the anti-sticking guide roller is used for leveling treatment. Through the monitoring and control system adjustment by the sensor, a constant tension is maintained during the winding process.

[0054] In step S7, in the slitting step, the film is guided to the cutter by a guide roller, and the tension control system is used to keep the film under tension during slitting. The cutting quality is monitored in real time and dimensional inspection is carried out. The slit film strips are guided to the winding device, and the winding tension is adjusted to make the film roll tight and neat.

[0055] By precisely calculating the raw material dosage for each layer and stirring evenly, the performance of each layer of the protective film can be guaranteed to meet the design requirements, making the physical properties of the final product, such as tensile strength and flexibility, uniform in all parts, and avoiding local performance defects caused by uneven raw material ratios. At the same time, automatically weighing materials improves production efficiency and metering accuracy, reducing human errors;

[0056] Melting the raw materials of different layers within a specific temperature range and performing shear separation processing helps the polymer molecular chains in the raw materials to better orient and arrange, thereby improving the mechanical and optical properties of the protective film. Different temperature controls can adapt to the characteristics of each layer of material, enabling each layer of raw material to reach the best molten state, laying a good foundation for subsequent forming processing;

[0057] Using a laminated filter with a precision of 20um to remove impurities and crystal points can effectively improve the cleanliness and flatness of the protective film. Impurities and crystal points may cause problems such as uneven light transmission and surface roughness of the protective film, affecting its appearance and service performance. After filtration, the quality and reliability of the protective film can be improved;

[0058] Precisely controlling the die head temperature and adjusting the air volume and draw line speed according to the set specifications can enable the melt to accurately expand and form a film bubble that meets the size and shape requirements. Appropriate temperature ensures that the melt has good fluidity and formability. Reasonable adjustment of the air volume and draw line speed can control the diameter and thickness uniformity of the film bubble, ensuring the specification accuracy and appearance quality of the protective film;

[0059] Cooling the film bubble to obtain a stable film bubble helps to fix the shape and size of the film bubble, preventing it from deforming during subsequent processing. At the same time, the cooling process can also further crystallize and orient the polymer molecular chains, improving the mechanical properties and stability of the protective film;

[0060] Flattening the film surface through herringbone clips, anti-sticking guide rollers, and tension control guide rollers and then winding it can ensure that the protective film remains flat during the winding process, avoiding problems such as wrinkles and adhesion. A good flattening effect is beneficial for subsequent slitting and use. The tension control guide roller can make the winding tension uniform, preventing the film roll from having uneven tightness and ensuring product quality;

[0061] Slitting the wound film into corresponding widths according to the usage specification requirements enables the protective film to meet the needs of different users and different application scenarios, improving the applicability and market competitiveness of the product. The slitting process can remove the uneven parts at the film edges, further improving the appearance quality and dimensional accuracy of the product.

[0062] Table 1 below is the parameter table of the embodiments and comparative examples of the present invention

[0063]

[0064]

[0065] Table 1 The following Table 2 shows the effect test method and data table of the present invention

[0066]

[0067] Table 2

[0068] The foregoing has shown and described the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments, and what is described in the above embodiments and the specification is only the principle of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements fall within the scope of the present invention claimed.

Claims

1. An electronic manufacturing die-cut co-extruded protective film, characterized in that, Including: The outer layer of blown film, the middle layer of blown film and the inner layer of blown film, wherein the outer layer of blown film includes 50-70 parts of hydrogenated styrene block copolymer A, 20-50 parts of hydrogenated styrene block copolymer B and 5-20 parts of polypropylene; The middle layer of blown film includes 20-50 parts of low density polyethylene, 20-50 parts of linear low density polyethylene and 20-40 parts of polypropylene; The inner layer of blown film includes 20-30 parts of low density polyethylene, 20-40 parts of high density polyethylene and 20-40 parts of polypropylene; Among them, the proportion of the outer layer of blown film is 10-20%, the proportion of the middle layer of blown film is 40-60%, and the proportion of the inner layer of blown film is 40-60%.

2. The electronic manufacturing die-cut co-extruded protective film according to claim 1, wherein The hydrogenated styrene block copolymer A does not contain unsaturated double bonds, and the processing temperature is 195-210 °C. The hydrogenated styrene block copolymer A includes one or more of Asahi Kasei S1606, Asahi Kasei H1221, Kraton 6700, Kraton 1645 and Kraton 1652; The hydrogenated styrene block copolymer A includes styrene, conjugated diene and hydrogenating agent.

3. An electronic manufacturing die-cut co-extruded protective film according to claim 1, characterized in that, The hydrogenated styrene block copolymer B does not contain unsaturated double bonds, and the processing temperature is 175-200 °C. The hydrogenated styrene block copolymer B includes one or more of Asahi Kasei L613, Asahi Kasei H1521, Kraton 1646, Kraton 6666 and Kraton 1643; The hydrogenated styrene block copolymer B includes styrene, conjugated diene and hydrogenating agent.

4. The electronic manufacturing die-cut co-extruded protective film according to claim 1, wherein The density of the polypropylene is 0.91 g / cm 3 , and the polypropylene in the outer layer of the blown film includes one or more of SKB310F, RP242G, and Cosmoplene W331; the polypropylene in the middle layer and the inner layer of the blown film includes one or more of SK R520Y, R701, J640, and T30S; the polypropylene is either homopolypropylene or copolymer polypropylene.

5. An electronic manufacturing die-cut co-extruded protective film according to claim 1, characterized in that, The low density polyethylene is one of autoclave process low density polyethylene and tubular process high pressure low density polyethylene; The linear low density polyethylene is one of butene copolymerized polyethylene, ethylene copolymerized polyethylene and octene copolymerized polyethylene.

6. A preparation method of an electronic manufacturing die-cut co-extrusion protective film, characterized in that, The preparation steps are as follows: S1. Prepare materials, including: the outer layer of blown film, the middle layer of blown film and the inner layer of blown film. By calculating the dosage of raw materials for each layer, automatically weigh the materials and stir evenly; S2. Melt processing, put the evenly stirred raw materials into a single screw extrusion device respectively. The processing temperature of the outer layer of blown film is controlled at 185-210 °C, and the processing temperatures of the middle layer and the inner layer of blown film are controlled at 195-210 °C. Melt the raw materials, and the melted materials are driven by the screw to different areas for shear separation processing; S3. Filter impurities, use a stack filter with a precision of 20um to filter the melt in the three-layer screw to remove impurities and crystal points; S4. Die head forming, the three-layer melt flows into the die head respectively. The die head temperature is controlled at 185-205 °C from bottom to top. Adjust the air volume and the traction wire speed according to the set specifications to make the melt blow up to form a film bubble; S5. Cooling and shaping, cool the film bubble to obtain a stable film bubble; S6. Flattening and winding, the cooled film bubble is flattened by a herringbone clip, multiple anti-sticking guide rollers and tension control guide rollers, and then wound; S7. Slitting into finished products, according to the usage specifications, slit the wound film into the corresponding width to finally obtain the protective film.

7. The preparation method of an electronic process die-cut co-extrusion protective film according to claim 6, characterized in that, In step S1, the weighed materials are respectively added into the temperature-controlled heating screws of the outer layer, the middle layer and the inner layer of the blown film, and shear separation and mixing processing are carried out for 5-10 minutes, and the screw motor speed is 40-50 r / min.

8. The preparation method of an electronic manufacturing die-cut co-extrusion protective film according to claim 6, characterized in that, In step S5, cooling is carried out by an air control automatic air ring with a wind speed of 5 - 10 m / s and a flow rate of 10 - 100 m 3 / min.

9. The preparation method of an electronic process die-cut co-extrusion protective film according to claim 6, characterized in that, In step S6, during the winding process, the film bubble is squeezed by the clamping plates to initially unfold the film surface, and an anti-sticking guide roller is used for leveling. Through the monitoring of sensors and the adjustment of the control system, a constant tension is maintained during the winding process.

10. The preparation method of an electronic manufacturing die-cut co-extrusion protective film according to claim 6, characterized in that, In step S7, during the slitting process, the film is guided to the cutter by the guide roller. The tension control system is used to keep the film under tension during slitting. The cutting quality is monitored in real time and dimensional inspection is carried out. The slit film strips are guided to the winding device, and the winding tension is adjusted to make the film roll tight and neat.

Images