PE (polyethylene) protective film for automobile and manufacturing method of PE protective film

Abstract

According to the PE protective film for the automobile and the manufacturing method, low-density polyethylene and high-density polyethylene are blended, meanwhile, dithio cyclic phosphate is preferably selected as a main flame retardant, a zinc borate / zinc oxide mixture is preferably selected as an auxiliary flame retardant, and the PE protective film has excellent tensile strength, flame retardance and ultraviolet resistance. The paint is suitable for surface protection of various automobile parts, and the automobile parts are prevented from being polluted, corroded and scratched in the production, processing, transportation, storage and use processes. The product has good tensile strength and adhesion performance, the PE protective film can be stably pasted, the situation that the two ends of the protective film are raised after the protective film is used for a period of time is reduced, the service life of the protective film can be prolonged, and the PE protective film has good flame retardance and ultraviolet resistance.

Description

Technical Field

[0001] The invention relates to the technical field of PE protective films, and in particular to a PE protective film for automobiles and a manufacturing method thereof. Background Art

[0002] Polyethylene is the simplest macromolecular organic compound and the most widely used macromolecular material in the world today. PE protective film is based on special polyethylene plastic film and can be used on the surface of various automotive trim materials. Its biggest advantage is to protect the original smooth and shiny surface. For this reason, domestic and foreign high-end automobile manufacturers and parts processing companies widely use PE protective film in the manufacturing process to protect products from pollution, corrosion and scratches, thereby improving the production quality and market competitiveness of corporate products.

[0003] However, with the development of the plastics industry, people have higher and higher requirements for the various properties of plastic products, especially the fire safety performance of plastic products, which requires not only flame retardancy, but also halogen-free and pollution-free. Polyethylene plastic is a plastic that is easy to burn, and its limiting oxygen index is only 17.4. Therefore, it is very necessary and of great significance to modify the flame retardant properties of PE protective film materials for automobiles. Summary of the invention

[0004] The technical problem to be solved by the present invention is to solve the deficiencies of the above-mentioned prior art as follows.

[0005] In order to solve the above technical problems, the present invention discloses a PE protective film for automobiles, comprising a protective film base, an adhesive and a release paper, wherein the adhesive is sprayed on one side of the protective film base and the release paper is added, and the protective film base comprises, by weight percentage: polyethylene: 80-100 parts; calcium carbonate: 20-30 parts; polypropylene carbonate: 5-8 parts; thiocyclic phosphate: 6-14 parts; a mixture of zinc borate and zinc oxide: 3-7 parts; graphene microsheets: 1-2 parts; and a toughening agent, an anti-ultraviolet agent and a lubricant.

[0006] Furthermore, the adhesive comprises, by weight percentage: polyurethane: 20-25 parts; propylene glycol methyl ether acetate: 10-15 parts; phenolic resin: 5-10 parts; adhesive: 20-25 parts; and a curing agent and a modifier.

[0007] Furthermore, the polyethylene is a blend of low-density polyethylene and high-density polyethylene, and the mass ratio of the low-density polyethylene to the high-density polyethylene is 2 to 3:1.

[0008] The present invention also discloses a method for manufacturing a PE film for automobiles:

[0009] Add 20-25 parts of polyurethane, 10-15 parts of propylene glycol methyl ether acetate, 5-10 parts of phenolic resin, and 20-25 parts of adhesive to a mixing device, mix and stir, increase the temperature to 60-70°C, rotate at 500-1000r / min, and stir for 20-50min; add a curing agent and a modifier, increase the temperature to 80-90°C, stir for 2-3h, and obtain an adhesive.

[0010] 80-100 parts of polyethylene, 20-30 parts of calcium carbonate and 5-8 parts of polypropylene carbonate are mixed in a blender for 15-20 minutes; 6-14 parts of thiocyclic phosphate, 3-7 parts of a mixture of zinc borate and zinc oxide, 1-2 parts of graphene microsheets, 1-3 parts of a toughening agent, 1-5 parts of an anti-ultraviolet agent and 0.1-0.3 parts of a lubricant are added and the mixture is stirred for 10-20 minutes to obtain a protective film base material.

[0011] The protective film base material is added into a twin-screw extruder, and then a semi-finished PE protective film is obtained through melting, mixing and stretching. The extrusion temperature of the extruder is 160-190°C, and the screw speed is 450-550r / min.

[0012] The adhesive is sprayed on one side of the semi-finished PE protective film and a release paper is added, and the PE protective film is obtained by cutting.

[0013] The invention has the following advantages: dithiocyclic phosphate is used as the main flame retardant, and the zinc borate / zinc oxide mixture is used as the auxiliary flame retardant, and has excellent tensile strength, flame retardancy and ultraviolet resistance; it has good tensile strength and adhesion performance, can stably adhere to the PE protective film, and reduce the situation that the two ends of the protective film are flaked after being used for a period of time, and can increase the service life; and the PE protective film has good flame retardancy and ultraviolet resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 The present invention is a flow chart of the production of a PE film for automobiles;

[0015] Figure 2 This is a schematic diagram of the temperature monitoring and adjustment principle in the present invention;

[0016] Figure 3 This is the schematic diagram of the emergency stop of the conveyor in the present invention. DETAILED DESCRIPTION

[0017] like Figure 1As shown, the preparation method of the adhesive is as follows: add 20-25 parts of polyurethane, 10-15 parts of propylene glycol methyl ether acetate, 5-10 parts of phenolic resin, and 20-25 parts of adhesive to a mixing device, mix and stir, increase the temperature to 60-70°C, rotate at 500-1000r / min, and stir for 20-50min; add a curing agent and a modifier, increase the temperature to 80-90°C, stir for 2-3h, and obtain an adhesive.

[0018] The preparation method of the protective film base layer is as follows: 80 to 100 parts of polyethylene, 20 to 30 parts of calcium carbonate, and 5 to 8 parts of polypropylene carbonate are mixed in a mixer and stirred for 15 to 20 minutes; 6 to 14 parts of thiocyclic phosphate, 3 to 7 parts of a mixture of zinc borate and zinc oxide, 1 to 2 parts of graphene microsheets, 1 to 3 parts of a toughening agent, 1 to 5 parts of an anti-ultraviolet agent, and 0.1 to 0.3 parts of a lubricant are added and stirred for 10 to 20 minutes to obtain a protective film base material.

[0019] The protective film base material is added into a twin-screw extruder, and then a semi-finished PE protective film is obtained through melting, mixing and stretching. The extrusion temperature of the extruder is 160-190°C, and the screw speed is 450-550r / min.

[0020] Cyclic dithiophosphate is a halogen-free, environmentally friendly flame retardant that does not affect the transparency of PE protective film and has good compatibility with base plastics and other additives. Zinc borate and zinc oxide are two non-toxic and inexpensive flame retardants. When used in combination, they have multiple functions such as good flame retardancy, carbonization, smoldering and smoke suppression, and droplet prevention, and have good synergistic flame retardant effects with cyclic dithiophosphate.

[0021] In this embodiment, the synergistic effect between flame retardants is reasonably utilized, and dithiocyclic phosphate is preferably used as the main flame retardant and the zinc borate / zinc oxide mixture is used as the auxiliary flame retardant.

[0022] Graphene microsheets are a type of graphene layered stack. Its layered structure can prevent combustible gas from escaping into the flame zone, prevent energy back-transmission and promote carbonization. It is expected to become a new type of flame retardant with high efficiency and low addition amount. The layered stack of graphene microsheets has excellent mechanical strength, electrical conductivity, thermal conductivity, as well as good lubrication, high temperature resistance, high temperature resistance and corrosion resistance, and low production cost. This product uses graphene microsheets in combination with dithiocyclic phosphate and zinc borate / zinc oxide, which has a good synergistic flame retardant effect, with a LOI of up to 32.6, and has passed the UL92V0 level in the vertical burning test. At the same time, graphene microsheets also improve the tensile strength and impact toughness of PE protective film.

[0023] The polyethylene used in this embodiment is a blend of low-density polyethylene and high-density polyethylene, and the mass ratio of low-density polyethylene to high-density polyethylene is 2 to 3:1. Low-density polyethylene is known for its low density, which makes it light and flexible, and is widely used in the field of plastic bags and protective films. High-density polyethylene is harder and has higher strength and better heat resistance. Blending the two in a suitable ratio can obtain a polyethylene material with moderate hardness and softness. Therefore, this product has excellent viscosity and tensile strength, and can effectively prevent the problem of warping after long-term use.

[0024] In this embodiment, polyurethane, propylene glycol methyl ether acetate, phenolic resin and adhesive are used as raw materials, and a curing agent and a modifier are added to prepare an adhesive with excellent performance. The modifier is preferably a coupling agent and a stabilizer. The adhesive is sprayed on one side of the semi-finished PE protective film and a release paper is added, and the PE protective film is obtained by cutting. The prepared adhesive can effectively solve the problem of winging at both ends generated during use.

[0025] After the adhesive protective film base material is prepared, the adhesive is sprayed on one side of the semi-finished PE protective film and release paper is added, and the PE protective film is obtained by cutting.

[0026] During the material mixing and melting stage, a temperature sensor and a central controller are provided in the exhaust duct. The central control processor is provided with a temperature reference value setting circuit and a temperature value comparator. The temperature sensor is connected to the temperature value comparator. The temperature value comparator compares the actual temperature value measured by the temperature sensor with the temperature reference value set by the temperature reference value setting circuit. The central control processor controls the intake fan and the exhaust fan to increase or decrease the air volume synchronously and equally through the exhaust fan drive circuit and the intake fan drive circuit according to the comparison result of the temperature value comparator.

[0027] like Figure 2 As shown, when working, the system compares the current temperature signal with the preset temperature signal and calculates the difference between them. If there is a temperature deviation, the controller will automatically adjust the operation of the actuator so that the temperature tends to the preset value. Therefore, the material temperature can be adjusted independently and specifically according to the temperature monitoring results, making the temperature control more independent and accurate, which is conducive to improving product quality, meeting the quality requirements of special functional plastic films, overcoming the influence of the golden temperature difference factor in production, and creating conditions for increasing production speed. This greatly improves the competitiveness of the product.

[0028] Protection devices include: Figure 3As shown. It includes a detection module, a data acquisition module, a processor and PLC industrial control. The detection module includes a photoelectric detector and a pressure sensor. The module is connected to the data collection module, and the data collection module is directly connected to the processor. When there is a signal transmission, the processor is directly connected to the PLC industrial control module to shut down the motor and stop it urgently. At the same time, the processor directly contacts the background server through the communication module to notify the safety problem in the first time.

[0029] When a safety accident such as pinching hands occurs during the transportation of the protective film, the processor will quickly take alarm and emergency stop measures through the data acquisition module, reducing the possibility of safety accidents, protecting the life and health of the staff, and improving work efficiency.

[0030] Visual shaking feeding is adopted, a transparent observation window is designed on the side wall of the hopper facing the operator, and the hopper is set as a movable hopper, and the hopper is controlled by a motor to perform micro-vibration. When the film blowing machine is working, the raw material particles are directly placed in the hopper, and the raw material particles are sent to the feed port through a vertical feeder, and then sent to the material channel through the feed port. When the raw material particles are found to be attached to the inner wall of the hopper through the observation window, the vibration motor is started to make the raw material particles fall off. A buffer pad is provided at the connection between the hopper and the feed port. The buffer pad is used to buffer the connection between the feed port and the hopper to prevent wear or damage to the connection caused by vibration.

[0031] In addition, the protective film conveyor emergency stop technology is adopted. The protection device includes a detection module, a data acquisition module, a processor and a PLC industrial control. It is easy to use. The pressure sensor and the photoelectric detector are used at the same time, which reduces the occurrence rate of accidents in production and improves work efficiency.

[0032] The comparison of economic indicators between the PE protective film prepared by the above preparation method and similar domestic products is shown in the following table

[0033]

[0034] The PE protective film of the present invention has the following advantages:

[0035] (1) High product quality: stable viscosity, no problem of winging at both ends during use. High tensile strength, high elongation, strong flame retardant performance, and excellent UV resistance.

[0036] (2) The product is easy to use and clean: generally hot-sticking is used, which is easy to remove and has good weather resistance. The bonding resin will not have adverse effects on the protected material products and complies with EU environmental monitoring regulations;

[0037] (3) Green and environmentally friendly: The use of dithiocyclic phosphate halogen-free environmentally friendly flame retardant reduces the emission of toxic substances without affecting the transparency and performance of the PE protective film.

Claims

1. A PE protective film for automobiles, comprising a protective film base, an adhesive and a release paper, wherein the adhesive is sprayed on one side of the protective film base and the release paper is added, characterized in that: The protective film base layer includes, by weight percentage: Polyethylene: 80-100 parts; Calcium carbonate: 20-30 parts; Polypropylene carbonate: 5-8 parts; Thiocyclic phosphate: 6-14 parts; Zinc borate and zinc oxide mixture: 3-7 parts; Graphene microsheets: 1-2 parts; As well as toughening agents, UV inhibitors and lubricants.

2. The PE protective film for automobiles according to claim 1, characterized in that: The adhesive comprises, by weight percentage: Polyurethane: 20-25 parts; Propylene glycol methyl ether acetate: 10-15 parts; Phenolic resin: 5-10 parts; Adhesive material: 20-25 parts; As well as curing agents and modifiers.

3. The PE protective film for automobile according to claim 1, characterized in that: The polyethylene is a blend of low-density polyethylene and high-density polyethylene, and the weight ratio of the low-density polyethylene to the high-density polyethylene is 2 to 3:

1.

4. The PE protective film for automobiles according to claim 2, characterized in that: The modifier is a coupling agent and a stabilizer.

5. A method for producing a PE film for automobiles, Add 20-25 parts of polyurethane, 10-15 parts of propylene glycol methyl ether acetate, 5-10 parts of phenolic resin, and 20-25 parts of adhesive to a mixing device, mix and stir, raise the temperature to 60-70°C, rotate at 500-1000r / min, and stir for 20-50min; add a curing agent and a modifier, raise the temperature to 80-90°C, stir for 2-3h, and obtain an adhesive; 80-100 parts of polyethylene, 20-30 parts of calcium carbonate, and 5-8 parts of polypropylene carbonate are mixed in a mixer and stirred for 15-20 minutes; 6-14 parts of thiocyclic phosphate, 3-7 parts of a mixture of zinc borate and zinc oxide, 1-2 parts of graphene microsheets, 1-3 parts of a toughening agent, 1-5 parts of an anti-ultraviolet agent, and 0.1-0.3 parts of a lubricant are added and stirred for 10-20 minutes to obtain a protective film base material; The protective film base material is added into a twin-screw extruder, and then a semi-finished PE protective film is obtained by melting, mixing and stretching. The extrusion temperature of the extruder is 160-190°C, and the screw speed is 450-550r / min; The adhesive is sprayed on one side of the semi-finished PE protective film and a release paper is added, and the PE protective film is obtained by cutting.

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