Antistatic film and preparation method thereof

Abstract

The invention relates to an antistatic film and a preparation method thereof, and belongs to the technical field of polymer film materials. The antistatic film is prepared from the following components in parts by weight: 100 parts of PP resin, 5 to 8 parts of hydrogenated petroleum resin, 4.5 to 5.5 parts of conductive filler, 1.2 to 1.6 parts of antistatic additive, 0.1 to 0.12 part of antioxidant, 0.08 to 0.1 part of light stabilizer and 2.5 to 3 parts of lubricant, the preparation method comprises the following steps: carrying out amine ester exchange on methyl acrylate and diethylenetriamine under the catalysis of sodium hydride to prepare a double-bond-terminated amide compound, namely an amidated matrix, carrying out addition on mercaptopropyltrimethoxysilane and the amidated matrix under the initiation of ultraviolet radiation, and introducing a methoxysilane structure to the end part of the amidated matrix for modification, so as to obtain the antistatic additive. Finally, bromopropane and residual amido of the silanization intermediate are subjected to quaternization treatment, and the antistatic auxiliary is obtained. The film material is endowed with good antistatic performance and packaging performance through the interaction of the antistatic auxiliaries.

Description

Technical Field

[0001] The invention belongs to the technical field of polymer film materials, and in particular relates to an antistatic film and a preparation method thereof. Background Art

[0002] Polypropylene (PP) itself is a thermoplastic polymer material with a high melting point and excellent comprehensive properties. It has the characteristics of low price, low specific gravity, excellent mechanical properties, good stress cracking resistance and wear resistance, high chemical stability, easy molding and processing, etc. Therefore, it is widely used in many industries such as chemical industry, electrical appliances, automobiles, construction, packaging, etc., especially in the packaging field. PP film has high strength and good barrier properties, and is an excellent material for flexible packaging; however, polypropylene is a completely non-polar polymer, so its electrical insulation is very high, and its surface resistivity is usually 10 14 - to 10 17 Ω, which makes polypropylene film very easy to accumulate static charge. During the production or processing, due to friction and other reasons, polypropylene film is easily charged with static electricity, and this static electricity is difficult to disappear through conduction, which seriously restricts its application.

[0003] In the prior art, by introducing antistatic agents into polypropylene film materials, the antistatic needs can be met in most fields; according to the form of introduction of antistatic agents, it mainly includes external addition method and internal addition method, among which, the external addition method is to attach antistatic agents on the surface of polypropylene base film by technical means to form static electricity evacuation channels on the surface of the base film. This method has a significant antistatic effect, but the molding process of the film material is complicated, and the antistatic agent layer on the surface forms an isolation layer, which affects the secondary processing of the film material and makes the versatility of the film material insufficient; the internal addition method is to compound a certain amount of antistatic agents in the film-making raw materials to form static electricity evacuation channels inside the film material. Compared with the external addition method, the process is simpler, but the amount of antistatic agents used is usually large. These external antistatic agents have a greater impact on the mechanical properties of the substrate, which deteriorates the packaging protection performance of the film material. The prior art can only seek a balance between the two. Summary of the invention

[0004] In order to solve the technical problems mentioned in the background technology, the object of the present invention is to provide an antistatic film and a preparation method thereof.

[0005] The purpose of the present invention can be achieved through the following technical solutions: An antistatic film comprises, by weight, 100 parts of PP resin, 5-8 parts of hydrogenated petroleum resin, 4.5-5.5 parts of conductive filler, 1.2-1.6 parts of antistatic auxiliary agent, 0.1-0.12 parts of antioxidant, 0.08-0.1 parts of light stabilizer and 2.5-3 parts of lubricant.

[0006] The antistatic auxiliary agent is prepared by the following method: Step A1: diethylenetriamine, methyl acrylate and anhydrous tetrahydrofuran are mixed, dry nitrogen is introduced for protection, the temperature is controlled at 5-15°C in an ice-water bath, stirring is applied at 120-150 rpm, sodium hydride is slowly added to react for 1.5-2h, then the temperature is raised to 60-70°C and refluxed for 3-4h. After the reaction is completed, tetrahydrofuran is removed by rotary evaporation to obtain an amidated matrix; Furthermore, the dosage ratio of diethylenetriamine, methyl acrylate, sodium hydride and anhydrous tetrahydrofuran is 0.1 mol: 0.2 mol: 20-30 mg: 45-60 mL, and under the catalysis of sodium hydride, methyl acrylate and diethylenetriamine undergo amine ester exchange to form an amide compound with a terminal double bond.

[0007] Step A2: Mix the amidated matrix, mercaptopropyltrimethoxysilane, dimethylphenylphosphine and anhydrous acetone, introduce dry nitrogen for protection, control the water bath temperature at 45-55°C, apply 180-240 rpm stirring and 150-200 W / m 2 UV irradiation, reaction for 2.8-3.5h, after the reaction is completed, acetone is removed by rotary evaporation to obtain a silylation intermediate; Furthermore, the amount ratio of the amidated matrix, mercaptopropyltrimethoxysilane, dimethylphenylphosphine and anhydrous acetone is 0.1 mol: 0.2 mol: 40-50 mg: 160-220 mL. Under ultraviolet irradiation, the active mercapto group at the end of mercaptopropyltrimethoxysilane is added to the end double bond of the amidated matrix, and methoxysilane structure modification is introduced into the end of the amidated matrix.

[0008] Step A3: Mix the silylation intermediate, bromopropane, tetrabutylammonium bromide and anhydrous carbon tetrachloride, introduce dry nitrogen protection, heat to 60-70°C, stir at 60-90 rpm, reflux for 8-10 hours, and remove carbon tetrachloride by rotary evaporation after the reaction to obtain an antistatic additive; Furthermore, the usage ratio of the silylation intermediate, bromopropane, tetrabutylammonium bromide and anhydrous carbon tetrachloride is 0.1 mol: 0.25-0.3 mol: 45-60 mg: 60-80 mL, and the excess bromopropane reacts with the residual amine group of the silylation intermediate to undergo quaternization reaction.

[0009] Preferably, the conductive filler is compounded from nano copper powder and nano acetylene carbon black.

[0010] The invention discloses a method for preparing an antistatic film, which specifically comprises the following steps: adding various raw materials according to weight proportions into a high-speed mixer for uniform mixing, transferring the raw materials into a twin-screw extruder for extrusion and pelletization, and then casting the pelletization into a film to obtain the antistatic film.

[0011] Furthermore, the temperature process parameters of extrusion pelletizing are: zone one 150-160°C, zone two 165-175°C, zone three 180-190°C, zone four 190-195°C, zone five 195-200°C, zone six 185-190°C, and die head 200-210°C.

[0012] Furthermore, the temperature process parameters of the cast film are: zone one 180-190°C, zone two 200-210°C, zone three 220-230°C, connector 230-235°C, die head 240-245°C, chill roller 30°C.

[0013] Beneficial effects of the present invention: The invention adopts an internal addition method to prepare an antistatic film, wherein the antistatic film takes PP resin as a matrix, and the conductive filler and the antistatic auxiliary agent interact to give the film material good antistatic performance and packaging performance; the antistatic auxiliary agent is prepared by methyl acrylate and diethylenetriamine undergoing amine ester exchange under the catalysis of sodium hydride to prepare a double-bond terminated amide compound, namely an amidated matrix, and then mercaptopropyltrimethoxysilane is added to the amidated matrix under ultraviolet irradiation to introduce methoxysilane structure modification to the end of the amidated matrix, namely a silanized intermediate, and finally bromopropane is used to perform quaternization treatment on the residual amine group of the silanized intermediate, thus obtaining the antistatic auxiliary agent; in the process of melt blending, the terminal methoxysilane of the antistatic auxiliary agent is coupled with the conductive filler, thereby improving the compatibility of the conductive filler with the PP matrix, which is beneficial to the uniformity of the conductive filler. The electrostatic conductive network is evenly dispersed, and the antistatic additive molecules loaded contain quaternary ammonium structures, which form a cationic charge layer near the surface of the conductive filler particles, which is conducive to the formation of more charge transfer channels between the conductive fillers, thereby making the film have good antistatic properties; the evenly dispersed conductive filler has little effect on the mechanical properties of the film, and the antistatic additive molecules loaded on the surface contain a large number of amide structures, which can promote the PP matrix to produce β-phase crystals near the surface of the conductive filler during the film forming process. β-crystalline PP has excellent toughness and forms a flexible transition layer between the rigid conductive filler and the PP matrix, further reducing the influence of the conductive filler on the mechanical properties of the film. At the same time, it reduces the failure of the charge transfer network caused by the separation of the conductive filler and the PP matrix, and maintains a stable electrostatic evacuation network. DETAILED DESCRIPTION

[0014] 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.

[0015] Example 1, preparation of antistatic film, the specific implementation process is as follows: (1) Preparation of antistatic additives Step A1: diethylenetriamine, methyl acrylate and anhydrous tetrahydrofuran are mixed, dry nitrogen is introduced for protection, the temperature is controlled at 15°C in an ice-water bath, stirring is applied at 150 rpm, sodium hydride is slowly added to react for 1.5 hours, and then the temperature is raised to 70°C and refluxed for 3 hours, wherein the amount ratio of diethylenetriamine, methyl acrylate, sodium hydride and anhydrous tetrahydrofuran is 0.1 mol: 0.2 mol: 20 mg: 60 mL. After the reaction is completed, tetrahydrofuran is removed by rotary evaporation to obtain an amidated matrix.

[0016] Step A2: Mix the amidated matrix, mercaptopropyltrimethoxysilane, dimethylphenylphosphine and anhydrous acetone, introduce dry nitrogen protection, control the water bath temperature at 55°C, apply 240 rpm stirring and 200 W / m 2 The reaction was carried out under ultraviolet irradiation for 2 h, wherein the usage ratio of the amidation matrix, mercaptopropyltrimethoxysilane, dimethylphenylphosphine and anhydrous acetone was 0.1 mol: 0.2 mol: 40 mg: 220 mL. After the reaction, the acetone was removed by rotary evaporation to obtain a silylation intermediate.

[0017] Step A3: Mix the silylation intermediate, bromopropane, tetrabutylammonium bromide and anhydrous carbon tetrachloride, introduce dry nitrogen protection, heat to 70°C, stir at 90rpm, and reflux for 8h, wherein the amount ratio of the silylation intermediate, bromopropane, tetrabutylammonium bromide and anhydrous carbon tetrachloride is 0.1mol:0.3mol:45mg:80mL. After the reaction, remove carbon tetrachloride by rotary evaporation to obtain an antistatic additive.

[0018] (2) Preparation of antistatic film Ingredients: The raw materials are calculated by weight: 100 parts of PP resin, and HP550J type resin raw material is used in the implementation process; 5 parts of hydrogenated petroleum resin, and FST-H100 type raw material is used in the implementation process; 4.5 parts of conductive filler, and nano copper powder and nano acetylene carbon black are premixed and compounded in a mass ratio of 1:1 in the implementation process; 1.2 parts of antistatic additive, which is self-made in this embodiment; 0.12 parts of antioxidant, and antioxidant 1010 and antioxidant 168 are premixed and compounded in a mass ratio of 2:1 in the implementation process; 0.1 parts of light stabilizer, and UV-237 type raw material is used in the implementation process; 2.5 parts of lubricant, and 420P type raw material is used in the implementation process.

[0019] Granulation: Add all raw materials into a high-speed mixer, mix at 800 rpm for 10 min, and then transfer to a twin-screw extruder for extrusion and pelletizing. The temperature process parameters for extrusion and pelletizing are: 160°C in zone 1, 165-175°C in zone 2, 190°C in zone 3, 195°C in zone 4, 200°C in zone 5, 190°C in zone 6, and 210°C in the die.

[0020] Cast film: The pellets are transferred to a cast film machine for cast film formation, wherein the temperature process parameters of the cast film formation are: 190°C for zone one, 210°C for zone two, 230°C for zone three, 235°C for connector, 245°C for die head, and 30°C for chill roller to obtain an antistatic film.

[0021] Example 2, preparation of antistatic film, the specific implementation process is as follows: (1) Preparation of antistatic additives Step A1: diethylenetriamine, methyl acrylate and anhydrous tetrahydrofuran are mixed, dry nitrogen is introduced for protection, the temperature is controlled at 5°C in an ice-water bath, stirring is applied at 120rpm, sodium hydride is slowly added to react for 2h, and then the temperature is raised to 60°C and refluxed for 4h, wherein the amount ratio of diethylenetriamine, methyl acrylate, sodium hydride and anhydrous tetrahydrofuran is 0.1mol:0.2mol:30mg:45mL. After the reaction is completed, tetrahydrofuran is removed by rotary evaporation to obtain an amidated matrix.

[0022] Step A2: Mix the amidated matrix, mercaptopropyltrimethoxysilane, dimethylphenylphosphine and anhydrous acetone, introduce dry nitrogen protection, control the water bath temperature at 45°C, apply 180 rpm stirring and 150 W / m 2 The reaction was carried out under ultraviolet irradiation for 3.5 hours, wherein the usage ratio of the amidation matrix, mercaptopropyltrimethoxysilane, dimethylphenylphosphine and anhydrous acetone was 0.1 mol: 0.2 mol: 50 mg: 160 mL. After the reaction, the acetone was removed by rotary evaporation to obtain a silylation intermediate.

[0023] Step A3: Mix the silylation intermediate, bromopropane, tetrabutylammonium bromide and anhydrous carbon tetrachloride, introduce dry nitrogen protection, heat to 60°C, stir at 60rpm, and reflux for 10h, wherein the amount ratio of the silylation intermediate, bromopropane, tetrabutylammonium bromide and anhydrous carbon tetrachloride is 0.1mol:0.25mol:60mg:60mL. After the reaction, remove carbon tetrachloride by rotary evaporation to obtain an antistatic additive.

[0024] (2) Preparation of antistatic film Ingredients: The raw materials are calculated by weight: 100 parts of PP resin, and HP550J type resin raw material is used in the implementation process; 8 parts of hydrogenated petroleum resin, and FST-H100 type raw material is used in the implementation process; 5.5 parts of conductive filler, and nano copper powder and nano acetylene carbon black are premixed and compounded in a mass ratio of 1:1 in the implementation process; 1.6 parts of antistatic additive, which is self-made in this embodiment; 0.1 part of antioxidant, and antioxidant 1010 and antioxidant 168 are premixed and compounded in a mass ratio of 2:1 in the implementation process; 0.08 part of light stabilizer, and UV-237 type raw material is used in the implementation process; 3 parts of lubricant, and 420P type raw material is used in the implementation process.

[0025] Granulation: Add all raw materials into a high-speed mixer, mix at 800 rpm for 10 min, and then transfer to a twin-screw extruder for extrusion and pelletizing. The temperature process parameters for extrusion and pelletizing are: 150°C in zone 1, 165°C in zone 2, 180°C in zone 3, 190°C in zone 4, 195°C in zone 5, 185°C in zone 6, and 200°C in the die.

[0026] Cast film: The pellets are transferred to a cast film machine for cast film formation, wherein the temperature process parameters of the cast film formation are: 180°C for zone one, 200°C for zone two, 220°C for zone three, 230°C for connector, 240°C for die head, and 30°C for chill roller to obtain an antistatic film.

[0027] Example 3, preparation of antistatic film, the specific implementation process is as follows: (1) Preparation of antistatic additives Step A1: diethylenetriamine, methyl acrylate and anhydrous tetrahydrofuran are mixed, dry nitrogen is introduced for protection, the temperature is controlled at 5°C in an ice-water bath, stirring is applied at 150rpm, sodium hydride is slowly added to react for 2h, and then the temperature is raised to 70°C and refluxed for 4h, wherein the amount ratio of diethylenetriamine, methyl acrylate, sodium hydride and anhydrous tetrahydrofuran is 0.1mol:0.2mol:25mg:55mL. After the reaction is completed, tetrahydrofuran is removed by rotary evaporation to obtain an amidated matrix.

[0028] Step A2: Mix the amidated matrix, mercaptopropyltrimethoxysilane, dimethylphenylphosphine and anhydrous acetone, introduce dry nitrogen for protection, control the water bath temperature at 50°C, apply 240 rpm stirring and 180 W / m 2 The reaction was carried out under ultraviolet irradiation for 3.2 hours, wherein the usage ratio of the amidation matrix, mercaptopropyltrimethoxysilane, dimethylphenylphosphine and anhydrous acetone was 0.1 mol: 0.2 mol: 45 mg: 200 mL. After the reaction was completed, the acetone was removed by rotary evaporation to obtain a silylation intermediate.

[0029] Step A3: Mix the silylation intermediate, bromopropane, tetrabutylammonium bromide and anhydrous carbon tetrachloride, introduce dry nitrogen protection, heat to 65°C, stir at 90 rpm, and reflux for 9.5 hours, wherein the amount ratio of the silylation intermediate, bromopropane, tetrabutylammonium bromide and anhydrous carbon tetrachloride is 0.1 mol: 0.28 mol: 55 mg: 75 mL. After the reaction, remove carbon tetrachloride by rotary evaporation to obtain an antistatic additive.

[0030] (2) Preparation of antistatic film Ingredients: The raw materials are calculated by weight: 100 parts of PP resin, and HP550J type resin raw material is used in the implementation process; 6 parts of hydrogenated petroleum resin, and FST-H100 type raw material is used in the implementation process; 5.2 parts of conductive filler, and nano copper powder and nano acetylene carbon black are premixed and compounded in a mass ratio of 1:1 in the implementation process; 1.4 parts of antistatic additive, which is self-made in this embodiment; 0.1 part of antioxidant, and antioxidant 1010 and antioxidant 168 are premixed and compounded in a mass ratio of 2:1 in the implementation process; 0.1 part of light stabilizer, and UV-237 type raw material is used in the implementation process; 2.8 parts of lubricant, and 420P type raw material is used in the implementation process.

[0031] Granulation: Add all raw materials into a high-speed mixer, mix at 800 rpm for 10 min, and then transfer to a twin-screw extruder for extrusion and pelletizing. The temperature process parameters for extrusion and pelletizing are: 160°C in zone 1, 170°C in zone 2, 180°C in zone 3, 190°C in zone 4, 200°C in zone 5, 190°C in zone 6, and 210°C in the die.

[0032] Cast film making: The pellets are transferred to a cast film machine for cast film making, wherein the temperature process parameters of the cast film making are: 190°C for zone one, 210°C for zone two, 220°C for zone three, 230°C for connector, 240°C for die head, and 30°C for chill roller to obtain an antistatic film.

[0033] Comparative Example 1 This comparative example refers to Example 3, except that the antistatic auxiliary agent is replaced with the same amount of antistatic agent SN, and the rest of the implementation process is exactly the same.

[0034] Comparative Example 2 This comparative example refers to Example 3, except that the antistatic agent is replaced by 0.5 parts of antistatic SN, 0.8 parts of silane coupling agent KH580 and 0.15 parts of NP-508 nucleating agent, and the rest of the implementation process is exactly the same.

[0035] Samples were taken from the antistatic film prepared as above, and the mechanical properties and heat sealing properties were tested according to GB / T 27740-2011 standard, and the surface resistivity was tested according to GB / T 1410-2006 standard. The specific test results are shown in the following table:

[0036] The test results in the above table show that the antistatic film of the embodiment has excellent toughness, and its mechanical properties are significantly better than those of the comparative example, and its heat sealing strength is good, and its surface resistivity reaches 10 8 Order of magnitude, suitable for antistatic packaging materials.

[0037] In the description of the specification, the description with reference to the terms "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0038] The above contents are merely examples and explanations of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in a similar manner. As long as they do not deviate from the invention or exceed the scope defined by the claims, they shall all fall within the protection scope of the present invention.

Claims

1. An antistatic film, characterized in that: The composition includes, by weight: 100 parts of PP resin, 5-8 parts of hydrogenated petroleum resin, 4.5-5.5 parts of conductive filler, 1.2-1.6 parts of antistatic additive, 0.1-0.12 parts of antioxidant, 0.08-0.1 parts of light stabilizer and 2.5-3 parts of lubricant; The antistatic auxiliary agent is prepared by the following method: Step A1: diethylenetriamine, methyl acrylate and anhydrous tetrahydrofuran are mixed, dry nitrogen is introduced for protection, the temperature is controlled at 5-15°C in an ice-water bath, sodium hydride is slowly added with stirring for 1.5-2h, then the temperature is raised to 60-70°C and refluxed for 3-4h, and tetrahydrofuran is removed by rotary evaporation after the reaction is completed to obtain an amidated matrix; Step A2: Mix the amidated matrix, mercaptopropyltrimethoxysilane, dimethylphenylphosphine and anhydrous acetone, introduce dry nitrogen for protection, control the water bath temperature at 45-55°C, stir and apply 150-200W / m 2 UV irradiation, reaction for 2.8-3.5h, after the reaction is completed, acetone is removed by rotary evaporation to obtain a silylation intermediate; Step A3: Mix the silylation intermediate, bromopropane, tetrabutylammonium bromide and anhydrous carbon tetrachloride, introduce dry nitrogen for protection, heat to 60-70°C, stir and reflux for reaction for 8-10h, and remove carbon tetrachloride by rotary evaporation after the reaction to obtain an antistatic additive.

2. An antistatic film according to claim 1, characterized in that: The usage ratio of diethylenetriamine, methyl acrylate, sodium hydride and anhydrous tetrahydrofuran is 0.1 mol: 0.2 mol: 20-30 mg: 45-60 mL.

3. An antistatic film according to claim 2, characterized in that: The usage ratio of the amidated matrix, mercaptopropyltrimethoxysilane, dimethylphenylphosphine and anhydrous acetone is 0.1 mol: 0.2 mol: 40-50 mg: 160-220 mL.

4. An antistatic film according to claim 3, characterized in that: The usage ratio of the silylation intermediate, bromopropane, tetrabutylammonium bromide and anhydrous carbon tetrachloride is 0.1 mol: 0.25-0.3 mol: 45-60 mg: 60-80 mL.

5. An antistatic film according to claim 1, characterized in that: The conductive filler is compounded by nano copper powder and nano acetylene carbon black.

6. The method for preparing an antistatic film according to claim 1, characterized in that: The specific method is: adding each raw material according to the weight ratio into a high-speed mixer and mixing evenly, transferring the raw materials into a twin-screw extruder for extrusion and pelletizing, and then casting the pellets into a film to obtain an antistatic film.

7. The method for preparing an antistatic film according to claim 6, characterized in that: The temperature process parameters of extrusion pelletizing are: zone 1 150-160℃, zone 2 165-175℃, zone 3 180-190℃, zone 4 190-195℃, zone 5 195-200℃, zone 6 185-190℃, and die head 200-210℃.

8. The method for preparing an antistatic film according to claim 6, characterized in that: The temperature process parameters of the cast film are: zone 1 180-190°C, zone 2 200-210°C, zone 3 220-230°C, connector 230-235°C, die 240-245°C, chill roller 30°C.

Images