Antistatic protective film for display screen preparation and preparation method thereof

Abstract

The invention discloses an antistatic protective film for display screen preparation and a preparation method thereof, and belongs to the technical field of screen protective films.The antistatic protective film for display screen preparation is prepared from, by weight, 80-90 parts of LLDPE, 20-30 parts of EVA resin composition, 6-10 parts of antistatic agent, 0.2-0.4 part of anti-blocking agent and 0.4-0.8 part of heat stabilizer. The preparation method comprises the following steps: adding LLDPE (Linear Low Density Polyethylene), EVA (Ethylene Vinyl Acetate) resin composition, an antistatic agent, an anti-blocking agent and a heat stabilizer into a high-speed mixer according to a formula, uniformly mixing, then adding into a double-screw extruder, extruding and granulating, and then drying to obtain polyethylene master batch; the polyethylene master batch is added into a blow molding machine, and the antistatic protective film for display screen preparation is prepared through a film blowing process. The anti-static protective film prepared by the invention has excellent flame retardant property, anti-static property, mechanical property and anti-aging property.

Description

Technical Field

[0001] The invention belongs to the technical field of screen protective films, and in particular relates to an antistatic protective film for display screen preparation and a preparation method thereof. Background Art

[0002] There are many types of protective films on the market, including PP, PVC, PE and other materials. Among them, polyethylene (PE) has been used in the field of protective films due to its excellent comprehensive performance, rich raw material sources and low cost. However, due to the structure of polyethylene itself, it has strong insulation properties. Insulation will become an unfavorable factor in many application scenarios, and even bring dangers. For example, static electricity is easily accumulated during production, transportation, application, separation, friction and collision, and it is not easy to eliminate. Therefore, there is an urgent need to prepare an antistatic protective film for display screen preparation.

[0003] Patent announcement number CN116925459B discloses an antistatic PE protective film and its preparation method. The patent adds LLDPE, EVA resin composition, antistatic agent, anti-blocking agent, ultraviolet absorber, and heat stabilizer into a high-speed mixer according to the formula and mixes them evenly, then adds them into a twin-screw extruder for extrusion granulation, and then dries them to obtain polyethylene masterbatch; then the polyethylene masterbatch is added into a blow molding machine, and an antistatic PE protective film is prepared by a film blowing process. The patent improves the antistatic performance and antistatic durability of the PE protective film, but the antistatic protective film for display screen preparation in the patent and the prior art still has problems such as poor flame retardancy. Summary of the invention

[0004] The purpose of the present invention is to provide an antistatic protective film for display screen preparation and a preparation method thereof, aiming to solve the problems mentioned in the background technology that the antistatic protective film for display screen preparation in the prior art still has poor flame retardant properties.

[0005] The purpose of the present invention can be achieved through the following technical solutions:

[0006] An antistatic protective film for display screen preparation comprises the following raw materials in parts by weight:

[0007] LLDPE 80-90 parts, EVA resin composition 20-30 parts, antistatic agent 6-10 parts, opening agent 0.2-0.4 parts, thermal stabilizer 0.4-0.8 parts.

[0008] The antistatic agent is prepared by reacting a flame retardant and anti-aging intermediate with amino-modified multi-walled carbon nanotubes, and the antistatic agent includes a flame retardant group, a benzophenone group and an amide group.

[0009] Multi-walled carbon nanotubes have high conductivity and can form a good conductive network in the material, thereby effectively conducting charges. When used as an antistatic agent, they can avoid the harm caused by static electricity accumulation.

[0010] Furthermore, the preparation method of the antistatic agent is:

[0011] S1: Under nitrogen protection, 2'-aminobenzophenone-2-carboxylic acid and diphenylphosphine chloride are added to dichloromethane, stirred, cooled to -5°C, triethylamine is added, reacted at -5°C for 2-2.5h, then heated to room temperature for 6h, filtered, washed, and dried after the reaction to obtain a flame retardant and anti-aging intermediate;

[0012] The usage ratio of 2'-aminobenzophenone-2-carboxylic acid, diphenylphosphine chloride, dichloromethane and triethylamine is 24 mg: 48 mg: 15 mL: 51 mg.

[0013] 2'-aminobenzophenone-2-carboxylic acid and diphenylphosphonium chloride undergo substitution reaction to obtain a flame retardant and anti-aging intermediate. In the above steps, triethylamine is used as an acid binding agent.

[0014] S2: Dissolve the flame retardant and anti-aging intermediate and amino multi-walled carbon nanotubes in DMF, add cross-linking agent dicyclohexylcarbodiimide, react at 50° C. for 24 hours, filter, wash, and vacuum dry at 40-60° C. for 24-48 hours to obtain an antistatic agent.

[0015] The usage ratio of the flame retardant and anti-aging intermediate, the amino multi-walled carbon nanotubes, DMF and dicyclohexylcarbodiimide is 95 mg: 45 mg: 20 mL: 45 mg.

[0016] The carboxyl group in the flame retardant and anti-aging intermediate reacts with the amino group in the amino multi-walled carbon nanotube to generate an amide group, thereby obtaining an antistatic agent.

[0017] Furthermore, the opening agent is oleamide.

[0018] Furthermore, the heat stabilizer is one or both of zinc stearate and calcium stearate.

[0019] The present invention also protects a method for preparing an antistatic protective film for display screen preparation, comprising the following steps:

[0020] A1. Add LLDPE, EVA resin composition, antistatic agent, anti-blocking agent and heat stabilizer into a high-speed mixer and mix them evenly, then add them into a twin-screw extruder for extrusion granulation, and then dry them to obtain polyethylene masterbatch;

[0021] A2. Add the polyethylene masterbatch obtained in step A1 into a blow molding machine, and prepare an antistatic protective film for display screen preparation through a film blowing process.

[0022] Furthermore, the temperature of extrusion granulation in step S1 is 190-210°C; the film blowing process in step S2 is: the temperature of zone 1 is 100-120°C, the temperature of zone 2 is 130-160°C, the temperature of zone 3 is 150-170°C, the temperature of zone 4 is 180-200°C, the temperature of zone 5 is 180-190°C, the die head temperature is 170-180°C, the blowing ratio is 1.5-2.5, and the drawing ratio is 1.5-3.

[0023] Beneficial effects of the present invention:

[0024] 1. The raw materials for preparing the antistatic protective film of the present invention contain an antistatic agent, which is prepared by the reaction of a flame retardant and anti-aging intermediate with an amino multi-walled carbon nanotube, and the flame retardant and anti-aging intermediate is prepared by a substitution reaction between 2'-aminobenzophenone-2-carboxylic acid and diphenylphosphonium chloride. The antistatic agent includes a flame retardant group, a benzophenone group and an amide group. Nitrogen-containing compounds decompose at high temperatures to produce a large amount of non-combustible gases, such as ammonia, carbon dioxide and water vapor, which can dilute the concentration of combustible gases and oxygen, thereby inhibiting the combustion chain reaction. Phosphorus-containing compounds decompose at high temperatures to produce phosphorus oxygen free radicals, which can capture hydrogen free radicals and hydroxyl free radicals in the combustion chain reaction, thereby terminating the combustion reaction. When it is used as a raw material for preparing an antistatic protective film, it can improve the flame retardant properties of the antistatic protective film for display screen preparation. The benzophenone group contains a benzene ring and a carbonyl structure. These functional groups can form intramolecular hydrogen bonds to form a chelate ring structure. When ultraviolet rays irradiate benzophenone compounds, the hydrogen bonds in the molecule oscillate, and the stable chelate ring opens, converting the absorbed ultraviolet energy into heat energy or releasing it in the form of harmless low-energy radiation, thereby avoiding ultraviolet damage to the material, increasing the aging resistance of the antistatic protective film used in the preparation of display screens, and extending the service life of the protective film. The amide group can improve the dispersibility of the antistatic agent in the raw material through the spatial position effect, thereby enhancing the mechanical properties of the protective film, and the improved dispersibility of the antistatic agent helps to form a more uniform conductive network and improve the antistatic performance of the protective film. DETAILED DESCRIPTION

[0025] The following will be combined with 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.

[0026] The amino-modified multi-walled carbon nanotubes in the present invention were purchased from Jiangsu Xianfeng Nanomaterial Technology Co., Ltd.

[0027] Preparation Example 1

[0028] The preparation method of the antistatic agent of this preparation example is:

[0029] S1: Under nitrogen protection, 2.4 g of 2'-aminobenzophenone-2-carboxylic acid and 48 mg of diphenylphosphine chloride were added to 15 mL of dichloromethane, stirred, cooled to -5°C, 51 mg of triethylamine was added, reacted at -5°C for 2 h, then heated to room temperature for 6 h, filtered after the reaction, washed, and dried to obtain a flame retardant and anti-aging intermediate;

[0030] S2: Dissolve 95 mg of the flame retardant and anti-aging intermediate and 45 mg of amino-modified multi-walled carbon nanotubes in 20 mL of DMF, add 45 mg of cross-linking agent dicyclohexylcarbodiimide, react at 50° C. for 24 h, filter, wash, and vacuum dry at 40° C. for 24 h to obtain an antistatic agent.

[0031] Preparation Example 2

[0032] The preparation method of the antistatic agent of this preparation example is:

[0033] S1: Under nitrogen protection, 2.4 g of 2'-aminobenzophenone-2-carboxylic acid and 48 mg of diphenylphosphine chloride were added to 15 mL of dichloromethane, stirred, cooled to -5°C, 51 mg of triethylamine was added, reacted at -5°C for 2.5 h, then heated to room temperature for 6 h, filtered after the reaction, washed, and dried to obtain a flame retardant and anti-aging intermediate;

[0034] S2: 95 mg of the flame retardant and anti-aging intermediate and 45 mg of the amino-modified multi-walled carbon nanotubes were dissolved in 20 mL of DMF, 45 mg of the cross-linking agent dicyclohexylcarbodiimide was added, the mixture was reacted at 50° C. for 24 h, filtered, washed, and vacuum dried at 60° C. for 48 h to obtain an antistatic agent.

[0035] Preparation Example 3

[0036] The preparation method of the antistatic agent of this preparation example is:

[0037] 50 mg of benzophenone-2-carboxylic acid and 45 mg of amino-modified multi-walled carbon nanotubes were dissolved in 20 mL of DMF, 45 mg of cross-linking agent dicyclohexylcarbodiimide was added, the mixture was reacted at 50° C. for 24 h, filtered, washed, and vacuum dried at 60° C. for 48 h to obtain an antistatic agent.

[0038] Preparation Example 4

[0039] The antistatic agent in this preparation example is amino-modified multi-walled carbon nanotubes.

[0040] Preparation Example 5

[0041] The antistatic agent in this preparation example is multi-walled carbon nanotubes.

[0042] Example 1

[0043] This embodiment provides a method for preparing an antistatic protective film for display screen preparation, comprising the following steps:

[0044] A1. According to the formula, 80 parts of LLDPE, 20 parts of EVA resin composition, 6 parts of antistatic agent prepared in Preparation Example 1, 0.2 parts of oleic acid amide, and 0.4 parts of zinc stearate were added into a high-speed mixer and mixed evenly, and then added into a twin-screw extruder and extruded and granulated at 190° C., and then dried to obtain polyethylene masterbatch;

[0045] A2. Add the polyethylene masterbatch obtained in step A1 into a blow molding machine, and prepare an antistatic protective film for display screen preparation by a film blowing process. The film blowing process is as follows: the temperature of zone 1 is 100° C., the temperature of zone 2 is 130° C., the temperature of zone 3 is 150° C., the temperature of zone 4 is 180° C., the temperature of zone 5 is 180° C., the temperature of the die head is 170° C., the blowing ratio is 1.5, and the draft ratio is 1.5.

[0046] Example 2

[0047] This embodiment provides a method for preparing an antistatic protective film for display screen preparation, comprising the following steps:

[0048] A1. According to the formula, 85 parts of LLDPE, 25 parts of EVA resin composition, 8 parts of antistatic agent prepared in Preparation Example 1, 0.3 parts of oleic acid amide, and 0.6 parts of calcium stearate were added into a high-speed mixer and mixed evenly, and then added into a twin-screw extruder for extrusion granulation at 200° C., and then dried to obtain polyethylene masterbatch;

[0049] A2. Add the polyethylene masterbatch obtained in step A1 into a blow molding machine, and prepare an antistatic protective film for display screen preparation by a film blowing process. The film blowing process is: the temperature of zone 1 is 110° C., the temperature of zone 2 is 145° C., the temperature of zone 3 is 160° C., the temperature of zone 4 is 190° C., the temperature of zone 5 is 187° C., the temperature of the die head is 175° C., the blow-up ratio is 2, and the draft ratio is 2.5.

[0050] Example 3

[0051] This embodiment provides a method for preparing an antistatic protective film for display screen preparation, comprising the following steps:

[0052] A1. According to the formula, 90 parts of LLDPE, 30 parts of EVA resin composition, 10 parts of antistatic agent prepared in Preparation Example 2, 0.4 parts of oleic acid amide, 0.4 parts of zinc stearate, and 0.4 parts of calcium stearate were added into a high-speed mixer and mixed evenly, and then added into a twin-screw extruder and extruded and granulated at 210° C., and then dried to obtain polyethylene masterbatch;

[0053] A2. Add the polyethylene masterbatch obtained in step A1 into a blow molding machine, and prepare an antistatic protective film for display screen preparation by a film blowing process. The film blowing process is: the temperature of zone 1 is 120°C, the temperature of zone 2 is 160°C, the temperature of zone 3 is 170°C, the temperature of zone 4 is 200°C, the temperature of zone 5 is 190°C, the temperature of the die head is 180°C, the blowing ratio is 2.5, and the draft ratio is 3.

[0054] Comparative Example 1

[0055] The difference between this comparative example and Example 1 is that the antistatic agent in Example 1 is replaced by the substance in Preparation Example 3, and the remaining raw materials and steps are the same as Example 1.

[0056] Comparative Example 2

[0057] The difference between this comparative example and Example 1 is that the antistatic agent in Example 1 is replaced by the substance in Preparation Example 4, and the remaining raw materials and steps are the same as Example 1.

[0058] Comparative Example 3

[0059] The difference between this comparative example and Example 1 is that the antistatic agent in Example 1 is replaced by the substance in Preparation Example 5, and the remaining raw materials and steps are the same as Example 1.

[0060] Comparative Example 4

[0061] This comparative example is different from Example 1 in that "6 parts of the antistatic agent prepared in Preparation Example 1" in Example 1 are replaced by "5 parts of the antistatic agent prepared in Preparation Example 1", and the remaining raw materials and steps are the same as Example 1.

[0062] Comparative Example 5

[0063] This comparative example is different from Example 3 in that "10 parts of the antistatic agent prepared in Preparation Example 2" in Example 1 is replaced by "11 parts of the antistatic agent prepared in Preparation Example 2", and the remaining raw materials and steps are the same as Example 3.

[0064] The performance of the antistatic protective films prepared in Examples 1 to 3 and Comparative Examples 1 to 5 was tested. The test items are as follows. The test results are shown in Table 1:

[0065] 1. Flame retardant performance: The flame retardant performance of the film material was tested using a JF-3 oxygen index tester.

[0066] 2. Mechanical properties: Tensile strength and elongation at break are tested according to standard GB / T 1040.1-2018.

[0067] 3. Anti-aging performance: 1000h light aging (6000l ux) treatment The anti-peep films prepared in Example 1 to Example 3 and Comparative Example 1 to Comparative Example 5 were tested for their tensile strength according to GB / T 1040.1-2018, and the tensile strength retention rate was calculated.

[0068] 4. Antistatic performance: Surface resistance is tested in accordance with GB / T1410-2006 Test method for volume resistivity and surface resistivity of solid insulating materials.

[0069] Table 1

[0070]

[0071]

[0072] Note: “ / ” in Table 1 means the item was not tested.

[0073] It can be seen from Table 1 that the antistatic protective film prepared by the present invention has excellent flame retardant properties, mechanical properties, anti-aging properties and antistatic properties.

[0074] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0075] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An antistatic protective film for display screen preparation, characterized in that: By weight, it includes the following raw materials: LLDPE 80-90 parts, EVA resin composition 20-30 parts, antistatic agent 6-10 parts, opening agent 0.2-0.4 parts, heat stabilizer 0.4-0.8 parts; The antistatic agent is prepared by reacting a flame retardant and anti-aging intermediate with amino-modified multi-walled carbon nanotubes, and the antistatic agent includes a flame retardant group, a benzophenone group and an amide group.

2. The antistatic protective film for display screen preparation according to claim 1, characterized in that: The opening agent is oleamide.

3. The antistatic protective film for display screen preparation according to claim 1, characterized in that: The heat stabilizer is one or both of zinc stearate and calcium stearate.

4. The antistatic protective film for display screen preparation according to claim 1, characterized in that: The preparation method of the antistatic agent is: S1: Under nitrogen protection, 2'-aminobenzophenone-2-carboxylic acid and diphenylphosphine chloride are added to dichloromethane, stirred, cooled to -5°C, triethylamine is added, reacted at -5°C for 2-2.5h, then heated to room temperature for 6h, filtered, washed, and dried after the reaction to obtain a flame retardant and anti-aging intermediate; S2: dissolving the flame retardant and anti-aging intermediate and the amino multi-walled carbon nanotubes in DMF, adding dicyclohexylcarbodiimide, reacting at 50° C. for 24 hours, filtering, washing, and vacuum drying at 40-60° C. for 24-48 hours to obtain an antistatic agent.

5. The antistatic protective film for display screen preparation according to claim 4, characterized in that: In step S1, the usage ratio of 2'-aminobenzophenone-2-carboxylic acid, diphenylphosphine chloride, dichloromethane and triethylamine is 24 mg:48 mg:15 mL:51 mg.

6. The antistatic protective film for display screen preparation according to claim 4, characterized in that: In step S2, the usage ratio of the flame retardant and anti-aging intermediate, the amino multi-walled carbon nanotubes, DMF, and dicyclohexylcarbodiimide is 95 mg: 45 mg: 20 mL: 45 mg.

7. The method for preparing an antistatic protective film for display screen preparation according to any one of claims 1 to 6, characterized in that: The following steps are involved: A1. Add LLDPE, EVA resin composition, antistatic agent, anti-blocking agent and heat stabilizer into a high-speed mixer and mix them evenly, then add them into a twin-screw extruder for extrusion granulation, and then dry them to obtain polyethylene masterbatch; A2. Add the polyethylene masterbatch obtained in step A1 into a blow molding machine, and prepare an antistatic protective film for display screen preparation through a film blowing process.

8. The method for preparing an antistatic protective film for display screen preparation according to claim 7, characterized in that: In step S1, the temperature of extrusion granulation is 190-210°C.

9. The method for preparing an antistatic protective film for display screen preparation according to claim 7, characterized in that: In step S2, the film blowing process is: the temperature of zone 1 is 100-120°C, the temperature of zone 2 is 130-160°C, the temperature of zone 3 is 150-170°C, the temperature of zone 4 is 180-200°C, the temperature of zone 5 is 180-190°C, the die head temperature is 170-180°C, the blowing ratio is 1.5-2.5, and the draft ratio is 1.5-3.

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