Antibacterial and anti-ultraviolet adhesive-free electrostatic adsorption protective film and preparation method thereof

Abstract

The present invention discloses an antibacterial, anti-ultraviolet, adhesive-free electrostatic adsorption protective film and a preparation method thereof, which relates to the technical field of polymer protective films, and includes layer A, layer B, layer C and layer D from top to bottom; wherein, layer A is LDPE; layer B is a mixed layer of LDPE and LLDPE with a mass ratio of 1:1; layer C is a mixed layer of LDPE and LLDPE with a mass ratio of 3:7; layer D is an adhesive layer; and the adhesive layer includes electrostatic adsorption fibers and antistatic materials. Compared with the currently used protective film materials, this product does not require the use of adhesives, and the polyethylene material film is adsorbed on the surface of the protected base material through electrostatic action, thereby protecting the related products, and through the doping of specific nanoparticles, a certain improvement in anti-ultraviolet, antibacterial and mechanical properties is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of polymer protective films, and more specifically to an antibacterial, anti-ultraviolet, adhesive-free electrostatic adsorption protective film and a preparation method thereof. Background Art

[0002] Acrylic is a chemical material, the chemical name is "PMMA" belongs to the polyacrylate class. Acrylic sheet is made of methyl methacrylate monomers, that is, polymethyl methacrylate sheet organic glass, also known as specially treated organic glass, is an alternative product of organic glass. In the application industry, the raw materials of acrylic generally appear in the form of sheets, etc. Due to its strong corrosion resistance, strong surface hardness and gloss, the application of acrylic sheet is becoming more and more extensive, especially in the fields of construction and advertising. With the development and progress of society, more and more acrylic sheets have begun to enter all walks of life and have made great contributions.

[0003] The surface of acrylic sheets shipped out of the factory needs to be covered with a protective film to protect the relevant products, avoid damage caused by bumps during handling, transportation, and use, and reduce oxidation and aging caused by contact with oxygen in the air. The performance and quality of the protective film are very important to the quality of the product. At present, the protective film still has the following problems:

[0004] (1) With the expansion of application scenarios, more requirements are put forward for protective films, such as antibacterial, anti-ultraviolet, mechanical properties, etc. However, the protective films currently used usually cannot meet the comprehensive requirements of antibacterial, anti-ultraviolet, mechanical properties, etc.

[0005] (2) The protective films currently used are usually made of PE, PVC, PET and other materials, and usually require adhesive bonding. However, adhesives usually contain certain volatile pollutants. Therefore, if relevant adhesives are used in the production process, it will cause certain environmental pollution and affect the health of workers. In addition, most of the protective films currently used require adhesive bonding, and during the use of the product, the adhesive usually remains on the surface of the product. Therefore, when using the related products, it may have a certain impact on the performance of the product and affect the health of the user. Therefore, it is necessary to develop a polymer protective film material that does not require the use of conventional adhesives, and achieve a protective effect on the surface of the protected substrate material. This has practical significance for the production of related products.

[0006] Therefore, how to provide an antibacterial, anti-UV, adhesive-free electrostatic adsorption protective film and its preparation method which does not require the use of conventional adhesives, but uses specific ingredients and utilizes the electrostatic effect between the two to achieve the adsorption of the polyethylene material film on the surface of the protected base material, thereby achieving the protection of related products is a technical problem that technical personnel in this field urgently need to solve. Summary of the invention

[0007] In view of this, the present invention provides an antibacterial, anti-ultraviolet, adhesive-free polyethylene material electrostatic adsorption protective film. The present invention can currently be applied to the surface protection of polymer plates such as acrylic, and in the future the scope of use can be expanded to the surface of other substrate materials, such as various stainless steel plates, aluminum-plastic plates, mirror plates, titanium plates, color steel plates, decorative plates, fireproof plates, fluorocarbon paint plates, PVC, PET sheets, glass, instruments, signs, household appliances, air conditioners, furniture, automobile manufacturing and other industries.

[0008] In order to achieve the above object, the present invention adopts the following technical solution:

[0009] An antibacterial, anti-ultraviolet and adhesive-free electrostatic adsorption protective film, which comprises, from top to bottom, a layer A, a layer B, a layer C and a layer D;

[0010] Wherein, the A layer is LDPE;

[0011] The B layer is a mixed layer of LDPE and LLDPE with a mass ratio of 1:1;

[0012] The C layer is a mixed layer of LDPE and LLDPE with a mass ratio of 3:7;

[0013] The D layer is an adhesive layer;

[0014] The adhesive layer includes electrostatic adsorption fibers and antistatic materials, and the mass ratio of the two is 3:1.

[0015] Preferably, the A layer also includes nanoparticles;

[0016] The A layer comprises, by mass percentage, 0.5-2% nanoparticles and 98-99.5% LDPE.

[0017] Preferably, the electrostatic adsorption fiber is polyvinylidene fluoride and its derivatives.

[0018] Preferably, the antistatic material is polyethylene oxide.

[0019] Preferably, the nanoparticles are niobium pentoxide, zirconium dioxide or titanium dioxide treated with a surfactant.

[0020] The material of the present invention is compounded with semiconductor nanomaterials such as niobium pentoxide, zirconium dioxide, titanium dioxide and the like of specific types and proportions, so that the related materials can achieve certain improvements in anti-ultraviolet, antibacterial and mechanical properties.

[0021] Preferably, the surfactant is cetyltrimethylammonium bromide or cetyltrimethylammonium chloride.

[0022] Another object of the present invention is to provide a method for preparing the above-mentioned antibacterial, anti-ultraviolet, adhesive-free electrostatic adsorption protective film, comprising the following steps:

[0023] (1) Raw material preparation

[0024] Weighing the raw materials of each layer of the protective film, and then drying the raw materials to remove the moisture contained in the raw materials;

[0025] (2) Ingredients and mixing

[0026] The raw materials of layer A, layer B, layer C and layer D are added to the extruder respectively, heated and melted to obtain the molten materials of layer A, layer B, layer C and layer D; the specific process parameters of the extruder are as follows: total radial width 1200-1400 mm, traction line speed 50-65 m / min, upper rotation speed 40-60 Hz, current 1-3 A, lower traction tension 9-10.5 kg;

[0027] (3) Extrusion blown film

[0028] Adjusting the pressure, allowing the molten materials of layer A, layer B, layer C and layer D to pass through the extruder and extrude into a continuous molten film to obtain layer A, layer B, layer C and layer D, and combining the layers by extrusion to obtain a semi-finished product;

[0029] (4) Drying and curing, slitting and packaging

[0030] The semi-finished product is dried, cut and packaged to obtain the electrostatic adsorption protective film.

[0031] Preferably, the drying in step (1) is performed at 60° C. for 4-8 hours.

[0032] Preferably, the heating and melting temperature in step (2) is 160-170° C.; and the pulling speed of the extruder in step (3) is 50-60 m / min.

[0033] Preferably, the drying in step (4) is at 60°C.

[0034] It can be seen from the above technical solution that compared with the prior art, the present invention has the following beneficial effects:

[0035] 1. Compared with the currently used protective film materials, this product does not require the use of adhesives. The polyethylene film is adsorbed on the surface of the protected base material through electrostatic action to protect the relevant products. Through the doping of specific nanoparticles, it achieves certain improvements in anti-ultraviolet, antibacterial and mechanical properties. It has very practical significance for the production, transportation and use of related products, and for the protection and quality assurance of goods.

[0036] 2. The present invention uses low-density polyethylene (LDPE) and linear low-density polyethylene (LLDPE). Due to the branching degree and structural characteristics of the molecular chain, these two polyethylene materials show good flexibility and impact resistance in physical properties. The adhesive layer contains electrostatic adsorption fibers to enhance the electrostatic adsorption effect of the film, wherein the main component of the electrostatic adsorption fiber is polyvinylidene fluoride related derivatives (PVDF), which can be well attached to the surface of the base material through electrostatic adsorption force. In addition, the related components of this layer contain a small amount of antistatic components, which can avoid the electrostatic repulsion between the membrane material and the substrate, and indirectly enhance the electrostatic adsorption effect.

[0037] 3. During processing, a large amount of static charge (static adsorption fiber) is injected into the surface of the adhesive layer, and the injection of static charge is evenly distributed to ensure that the adsorption effect of the film is consistent, so that the surface has a strong static field. Since the static electricity cannot be felt on the outside of the static film, users will not be disturbed by static electricity during use. It is suitable for surfaces that are sensitive to adhesive or glue residues. It is adsorbed on the surface of acrylic sheets and will not leave glue when torn off, which has the function of protecting related products. It can protect related products from damage caused by bumps during handling, transportation, and use, and reduce oxidation and aging caused by contact with oxygen in the air. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0039] Figure 1 The accompanying drawing is a schematic diagram of the structure provided by the present invention;

[0040] Figure 2 This is the microscopic morphology of the electrostatic adsorption protective film without adding nanoparticles;

[0041] Figure 3 This is the microscopic morphology of the electrostatic adsorption protective film with 2% niobium pentoxide added;

[0042] Figure 4is a tensile curve diagram of the electrostatic adsorption protective film without adding nanoparticles;

[0043] Figure 5 This is the tensile curve of the electrostatic adsorption protective film with 2% niobium pentoxide added. DETAILED DESCRIPTION

[0044] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0045] Example 1

[0046] This embodiment provides an antibacterial, anti-ultraviolet, adhesive-free electrostatic adsorption protective film, which includes, from top to bottom, a layer A, a layer B, a layer C, and a layer D;

[0047] The A layer includes, by mass percentage, 5% niobium pentoxide treated with hexadecyltrimethylammonium bromide and 95% LDPE; the B layer is a mixed layer of LDPE and LLDPE in a mass ratio of 1:1; the C layer is a mixed layer of LDPE and LLDPE in a mass ratio of 3:7; and the D layer is an adhesive layer;

[0048] In this embodiment, the adhesive layer includes polyvinylidene fluoride and polyethylene oxide, and the mass ratio of the two is 3:1.

[0049] Example 2

[0050] This embodiment provides an antibacterial, anti-ultraviolet, adhesive-free electrostatic adsorption protective film, which includes, from top to bottom, a layer A, a layer B, a layer C, and a layer D;

[0051] The A layer includes, by mass percentage, 2% zirconium dioxide treated with hexadecyltrimethylammonium chloride and 98% LDPE; the B layer is a mixed layer of LDPE and LLDPE in a mass ratio of 1:1; the C layer is a mixed layer of LDPE and LLDPE in a mass ratio of 3:7; and the D layer is an adhesive layer;

[0052] In this embodiment, the adhesive layer includes polyvinylidene fluoride and polyethylene oxide, and the mass ratio of the two is 3:1.

[0053] Example 3

[0054] This embodiment provides an antibacterial, anti-ultraviolet, adhesive-free electrostatic adsorption protective film, which includes, from top to bottom, a layer A, a layer B, a layer C, and a layer D;

[0055] The A layer includes, by mass percentage: 3% titanium dioxide treated with hexadecyltrimethylammonium bromide and 97% LDPE; the B layer is a mixed layer of LDPE and LLDPE in a mass ratio of 1:1; the C layer is a mixed layer of LDPE and LLDPE in a mass ratio of 3:7; the D layer is an adhesive layer;

[0056] In this embodiment, the adhesive layer includes polyvinylidene fluoride and polyethylene oxide, and the mass ratio of the two is 3:1.

[0057] Example 4

[0058] This embodiment provides a method for preparing the above-mentioned antibacterial and anti-ultraviolet adhesive-free electrostatic adsorption protective film, comprising the following steps:

[0059] (1) Raw material preparation

[0060] Weigh the raw materials of each layer of the protective film, and then dry the raw materials at 60°C for 7 hours to remove the moisture contained in the raw materials;

[0061] (2) Ingredients and mixing

[0062] The raw materials of layer A, layer B, layer C and layer D were added to the extruder respectively, and heated and melted at 160°C to obtain molten materials of layer A, layer B, layer C and layer D; the specific process parameters of the extruder were as follows: total radial width 1200 mm, traction line speed 55 m / min, upper rotation speed 45 Hz, current 2 A, lower traction tension 9 kg;

[0063] (3) Extrusion blown film

[0064] The pressure is adjusted so that the molten materials of the A layer, the B layer, the C layer and the D layer pass through the extruder to extrude into a continuous molten film. The pulling speed of the extruder is 60 m / min to obtain the A layer, the B layer, the C layer and the D layer, and the layers are combined by extrusion to obtain a semi-finished product;

[0065] (4) Drying and curing, slitting and packaging

[0066] The semi-finished product is dried at 60° C., and then cut and packaged to obtain the electrostatic adsorption protective film.

[0067] Example 5

[0068] This embodiment provides a method for preparing the above-mentioned antibacterial and anti-ultraviolet adhesive-free electrostatic adsorption protective film, comprising the following steps:

[0069] (1) Raw material preparation

[0070] Weigh the raw materials of each layer of the protective film, and then dry the raw materials at 60°C for 4 hours to remove the moisture contained in the raw materials;

[0071] (2) Ingredients and mixing:

[0072] The raw materials of layer A, layer B, layer C and layer D were added to the extruder respectively, and heated and melted at 170°C to obtain molten materials of layer A, layer B, layer C and layer D; the specific process parameters of the extruder were as follows: total radial width 1400 mm, traction line speed 50 m / min, upper rotation speed 40 Hz, current 3 A, lower traction tension 10.5 kg;

[0073] (3) Extrusion blown film

[0074] The pressure is adjusted so that the molten materials of the A layer, the B layer, the C layer and the D layer pass through the extruder to extrude into a continuous molten film. The pulling speed of the extruder is 50 m / min to obtain the A layer, the B layer, the C layer and the D layer, and the layers are combined by extrusion to obtain a semi-finished product;

[0075] (4) Drying and curing, slitting and packaging

[0076] The semi-finished product is dried at 60° C., and then cut and packaged to obtain the electrostatic adsorption protective film.

[0077] Performance test

[0078] Microscopic morphology characterization of PE film

[0079] Figure 2 This is the microscopic morphology of the electrostatic adsorption protective film without adding nanoparticles. Figure 3 This is the microscopic morphology of the electrostatic adsorption protective film with 2% niobium pentoxide added. It can be seen from the figure that there are still a few uneven areas on the surfaces of both.

[0080] Tensile properties test

[0081] The tensile strength was measured by tensile testing, and the relevant curves are shown in Figure 3 and Figure 4 As shown:

[0082] Figure 4 The tensile curve of the electrostatic adsorption protective film without adding nanoparticles, from which it can be concluded that its elongation at break is 248.7%, and the tensile strength is 27.663 MPa;

[0083] Figure 5 This is the tensile curve of the electrostatic adsorption protective film with 2% niobium pentoxide added. From the figure, it can be concluded that its elongation at break is 220.8% and the tensile strength is 46.6983 MPa.

[0084] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part.

[0085] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An antibacterial, anti-ultraviolet, adhesive-free electrostatic adsorption protective film, characterized in that: From top to bottom, it includes layer A, layer B, layer C and layer D; Wherein, the A layer is LDPE; The B layer is a mixed layer of LDPE and LLDPE with a mass ratio of 1:1; The C layer is a mixed layer of LDPE and LLDPE with a mass ratio of 3:7; The D layer is an adhesive layer; The adhesive layer includes electrostatic adsorption fibers and antistatic materials, and the mass ratio of the two is 3:1; The A layer also includes nanoparticles; The A layer comprises, by mass percentage: 0.5-2% nanoparticles and 98-99.5% LDPE; The nanoparticles are niobium pentoxide, zirconium dioxide or titanium dioxide treated with a surfactant.

2. The antibacterial, anti-ultraviolet, adhesive-free electrostatic adsorption protective film according to claim 1, characterized in that: The electrostatic adsorption fiber is polyvinylidene fluoride and its derivatives.

3. The antibacterial, anti-ultraviolet, adhesive-free electrostatic adsorption protective film according to claim 2, characterized in that: The antistatic material is polyethylene oxide.

4. The antibacterial, anti-ultraviolet, adhesive-free electrostatic adsorption protective film according to claim 3, characterized in that: The surfactant is hexadecyltrimethylammonium bromide or hexadecyltrimethylammonium chloride.

5. A method for preparing the antibacterial, anti-ultraviolet, adhesive-free electrostatic adsorption protective film according to any one of claims 2 to 4, characterized in that: The following steps are involved: (1) Raw material preparation Weighing the raw materials of each layer of the protective film, and then drying the raw materials to remove the moisture contained in the raw materials; (2) Ingredients and mixing The raw materials of layer A, layer B, layer C and layer D are respectively added into the extruder, heated and melted to obtain molten materials of layer A, layer B, layer C and layer D; the specific process parameters of the extruder are as follows: total width 1200-1400 mm, traction line speed 50-65 m / min, upper rotation speed 40-60 Hz, current 1-3 A, lower traction tension 9-10.5 kg; (3) Extrusion blown film Adjust the pressure so that the molten materials of layer A, layer B, layer C and layer D pass through the extruder and are extruded into a continuous molten film to obtain layer A, layer B, layer C and layer D, and combine the layers by extrusion to obtain a semi-finished product; (4) Drying and curing, slitting and packaging The semi-finished product is dried, cut and packaged to obtain the electrostatic adsorption protective film.

6. The method for preparing an antibacterial, anti-ultraviolet, adhesive-free electrostatic adsorption protective film according to claim 5, characterized in that: The drying in step (1) is performed at 60° C. for 4-8 hours.

7. The method for preparing an antibacterial, anti-ultraviolet, adhesive-free electrostatic adsorption protective film according to claim 5, characterized in that: The heating and melting temperature in step (2) is 160-170° C.; the pulling speed of the extruder in step (3) is 50-60 m / min.

8. The method for preparing an antibacterial, anti-ultraviolet, adhesive-free electrostatic adsorption protective film according to claim 5, characterized in that: The drying temperature in step (4) is 60°C.

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