Production method of flame-retardant PET (Polyethylene Terephthalate) composite current collector base film

Abstract

The invention discloses a production method of a flame-retardant PET composite current collector base film. The base film comprises an outer surface layer, a middle core layer and an inner surface layer, the outer surface layer is composed of PET, silicon dioxide, titanium dioxide, carbodiimide, a light stabilizer and an antioxidant; the middle core layer is prepared from PET (Polyethylene Terephthalate), tris (dibromophenyl) phosphate, antimony trioxide and nano ferroferric oxide; and the inner surface layer is prepared from PET (Polyethylene Terephthalate), glass fibers, an ethyl-methyl acrylate-glycidyl methacrylate terpolymer and an ethylene-methyl acrylate copolymer. The tris (dibromophenyl) phosphate of the middle core layer is used as a main flame retardant, the flame retardant effect on PET is improved by utilizing a halogen-phosphorus synergistic effect, and antimony trioxide is used as a synergist.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of PET base film, in particular to a production method of flame-retardant PET composite current collector base film. BACKGROUND

[0002] Polyethylene terephthalate (PET) has the advantages of high strength, good wear resistance and good chemical stability, but it belongs to a melt flammable material, and the limiting oxygen index is very low. When burning, a large amount of heat is generated, and there is a serious melt dripping phenomenon, which can easily cause a fire, limiting its application. Therefore, it is particularly important to modify PET for flame retardation. Therefore, how to develop a PET composite current collector base film that can improve the flame retardant effect is the research direction of the workers in the field. SUMMARY

[0003] In view of the defects of the prior art, the purpose of the present application is to provide a production method of flame-retardant PET composite current collector base film.

[0004] To solve the above problems, the technical solution of the present application is: a production method of flame-retardant PET composite current collector base film, the base film comprising an outer surface layer, a middle core layer and an inner surface layer; The outer surface layer is composed of PET, silicon dioxide, titanium dioxide, carbodiimide, light stabilizer and antioxidant; The middle core layer is composed of PET, tris (dibromophenyl) phosphate, diantimony trioxide and nano ferric oxide; The inner surface layer is composed of PET, glass fiber, ethyl-methyl acrylate-glycidyl methacrylate terpolymer and ethylene-methyl acrylate copolymer; The production method comprises the following steps: (1) The raw materials are weighed according to the proportions of the components of the outer surface layer, the middle core layer and the inner surface layer respectively; (2) The raw materials of the outer surface layer, the middle core layer and the inner surface layer are respectively blended and sent into the respective extruders for plasticizing and mixing; (3) The molten melt is respectively sent into the die head, and the melt is combined in the die head and then formed into a molten sheet through the flat die head opening; (4) The sheet is attached to the chill roller by air knife and quenched to form an unformed sheet, and then the sheet is formed into a cast sheet after water bath cooling; (5) The cast sheet is stretched to form a film; (6) The film thickness is detected by infrared rays, and the corresponding thickness deviation is fed back to the die head, and the corresponding position screw bolt heating power is slightly moved to correct the film thickness deviation; (7) The film is wound.

[0005] Further, the components of the outer surface layer, the intermediate core layer and the inner surface layer are in a mass ratio of 20% for the outer surface layer, 60% for the intermediate core layer and 20% for the inner surface layer.

[0006] Further, the components of the intermediate core layer are in a mass ratio of 80.9% for PET, 16% for tri(dibromophenyl) phosphate, 3% for antimony trioxide and 0.1% for nano four-iron oxide.

[0007] Further, the components of the inner surface layer are in a mass ratio of 86% for PET, 12% for glass fiber, 1% for ethyl-methyl acrylate-glycidyl methacrylate terpolymer and 1% for ethylene-methyl acrylate copolymer.

[0008] Further, the components of the outer surface layer are in a mass ratio of 86% for PET, 1% for silicon dioxide, 1% for titanium dioxide, 2% for carbodiimide, 5% for light stabilizer and 5% for antioxidant.

[0009] Further, the light stabilizer is light stabilizer UV-770 and the antioxidant is antioxidant 1010.

[0010] The beneficial effects of the present application are that tri(dibromophenyl) phosphate in the intermediate core layer is used as the main flame retardant, the halogen-phosphorus synergistic effect is utilized to improve the flame retardant effect on PET, and antimony trioxide is used as the synergist; The inner surface layer is toughened and modified to PET by the glass fiber, the ethyl-methyl acrylate-glycidyl methacrylate terpolymer and the ethylene-methyl acrylate copolymer, so that the material has good elongation and impact toughness; The silicon dioxide in the outer surface layer is used as the anti-adhesive, the titanium dioxide makes the film white and opaque, has the effect of reflecting light, the carbodiimide is easy to react with the carboxylic acid generated by the hydrolysis of the ester group in the polyester structure to generate the ureide derivative, thereby eliminating the carboxyl group, preventing the hydrolysis from spreading, playing the role of chain breaking and reconnection, the light stabilizer plays the role of preventing oxidation reaction and delaying aging, the antioxidant achieves the purpose of preventing auto-oxidation, that is, the film has the effect of preventing hydrolysis and anti-aging, and the service life is improved. BRIEF DESCRIPTION OF DRAWINGS

[0011] Figure 1 The figure is a schematic diagram of the base film of the present application.

[0012] As shown in the figure: 1 - outer surface layer, 2 - intermediate core layer, 3 - inner surface layer. DETAILED DESCRIPTION

[0013] In order to compare the technical solutions of the present application more intuitively and completely, the following non-limiting characteristic descriptions are made in combination with the drawings of the present application: A production method of a flame-retardant PET composite current collector base film, the base film comprising an outer surface layer 1, an intermediate core layer 2 and an inner surface layer 3; The outermost layer 1 is composed of PET, silicon dioxide, titanium dioxide, carbodiimide, light stabilizer, and antioxidant; The intermediate core layer 2 is composed of PET, tris(dibromophenyl) phosphate, antimony trioxide, and nano-iron tetroxide; The inner surface layer 3 is composed of PET, glass fiber, ethyl methyl acrylate-glycidyl methacrylate terpolymer, and ethylene-methyl acrylate copolymer. The production method of flame-retardant PET composite current collector film includes the following steps: (1) Weigh the raw materials according to the proportions of each component in the outer layer, middle core layer and inner surface layer; (2) The raw materials for the outer layer, the middle core layer and the inner surface layer are blended separately and fed into their respective extruders for mixing and plasticizing; (3) The molten melt is fed into the die head separately. After the melt merges in the die head, it forms a molten sheet through the flat die head opening. (4) The sheet is attached to the cooling roller with an air knife and cooled rapidly to form an unshaped sheet. Then, the sheet is shaped into a cast sheet after being cooled in a water bath. (5) The cast sheet is stretched to form a thin film; (6) The film thickness is detected by infrared light and the corresponding thickness deviation is fed back to the die head. The thickness deviation of the film is corrected by micro-adjusting the heating power of the bolts at the corresponding positions. (7) Wind up the film.

[0014] The components of the outer layer, the middle core layer, and the inner surface layer are in the following mass ratio: outer layer 20%, middle core layer 60%, and inner surface layer 20%.

[0015] The components of the intermediate core layer by mass ratio are: PET 80.9%, tris(dibromophenyl) phosphate 16%, antimony trioxide 3%, and nano-iron tetroxide 0.1%.

[0016] The components of the inner surface layer are as follows by mass ratio: PET 86%, glass fiber 12%, ethyl methyl acrylate-glycidyl methacrylate terpolymer 1%, and ethylene-methyl acrylate copolymer 1%.

[0017] The outer layer consists of the following components by mass ratio: PET 86%, silicon dioxide 1%, titanium dioxide 1%, carbodiimide 2%, light stabilizer 5%, and antioxidant 5%.

[0018] The light stabilizer is UV-770, and the antioxidant is antioxidant 1010.

[0019] The beneficial effects of this invention are: tris(dibromophenyl) phosphate in the middle core layer serves as the main flame retardant, utilizing the halogen-phosphorus synergistic effect to improve the flame retardant effect on PET, and antimony trioxide serves as a synergist; The inner surface layer is toughened and modified by glass fiber, ethyl methyl acrylate-glycidyl methacrylate terpolymer, and ethylene-methyl acrylate copolymer, giving the material good elongation and impact toughness. The outer layer of silica acts as an anti-sticking agent, while titanium dioxide makes the film white and opaque, reflecting light. Carbodiimide readily reacts with carboxylic acids generated by the hydrolysis of ester groups in the polyester structure to form acylurea derivatives, thereby eliminating carboxyl groups, preventing hydrolysis propagation, and playing a role in chain breakage and reconnection. The light stabilizer prevents oxidation reactions and delays aging, while the antioxidant prevents auto-oxidation. Thus, the film has anti-hydrolysis and anti-aging properties, improving its service life.

Claims

1. A method for producing a flame-retardant PET composite current collector film, characterized in that: The base film consists of an outer layer, a middle core layer, and an inner layer; The outer layer is composed of PET, silica, titanium dioxide, carbodiimide, light stabilizer, and antioxidant. The intermediate core layer is composed of PET, tris(dibromophenyl) phosphate, antimony trioxide, and nano-iron tetroxide; The inner surface layer is composed of PET, glass fiber, ethyl methyl acrylate-glycidyl methacrylate terpolymer, and ethylene-methyl acrylate copolymer; The production method includes the following steps: (1) Weigh the raw materials according to the proportions of each component in the outer layer, middle core layer and inner surface layer; (2) The raw materials for the outer layer, the middle core layer and the inner surface layer are blended separately and fed into their respective extruders for mixing and plasticizing; (3) The molten melt is fed into the die head separately. After the melt merges in the die head, it forms a molten sheet through the flat die head opening. (4) The sheet is attached to the cooling roller with an air knife and cooled rapidly to form an unshaped sheet. Then, the sheet is shaped into a cast sheet after being cooled in a water bath. (5) The cast sheet is stretched to form a thin film; (6) The film thickness is detected by infrared light and the corresponding thickness deviation is fed back to the die head. The thickness deviation of the film is corrected by micro-adjusting the heating power of the bolts at the corresponding positions. (7) Wind up the film.

2. The method for producing a flame-retardant PET composite current collector film according to claim 1, characterized in that: The components of the outer layer, the middle core layer, and the inner surface layer are in the following mass ratio: outer layer 20%, middle core layer 60%, and inner surface layer 20%.

3. The method for producing a flame-retardant PET composite current collector film according to claim 1, characterized in that: The components of the intermediate core layer by mass ratio are: PET 80.9%, tris(dibromophenyl) phosphate 16%, antimony trioxide 3%, and nano-iron tetroxide 0.1%.

4. The method for producing a flame-retardant PET composite current collector film according to claim 1, characterized in that: The components of the inner surface layer are as follows by mass ratio: PET 86%, glass fiber 12%, ethyl methyl acrylate-glycidyl methacrylate terpolymer 1%, and ethylene-methyl acrylate copolymer 1%.

5. The method for producing a flame-retardant PET composite current collector film according to claim 1, characterized in that: The outer layer consists of the following components by mass ratio: PET 86%, silicon dioxide 1%, titanium dioxide 1%, carbodiimide 2%, light stabilizer 5%, and antioxidant 5%.

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