Ultrathin barrier polyester film and preparation method thereof

Abstract

The invention relates to the technical field of polyester films, in particular to an ultrathin barrier polyester film and a preparation method thereof. The invention relates to an ultra-thin barrier polyester film, which is characterized in that the high-barrier ultra-thin polyester film is divided into an upper layer and a lower layer; the upper layer is an olefin-olefin alcohol copolymer or an ethylene-acrylic acid copolymer or a nano silicon dioxide modified ethylene-vinyl alcohol copolymer, and the lower layer is prepared from the following raw materials: dispersion liquid of a non-metallic material and polyethylene naphthalate. The high-barrier ultrathin polyester film provided by the invention has high barrier property and good tolerance effect on environmental factors such as climate change, ultraviolet radiation and the like, the thickness of the polyester film is superior to that of a common polyester film, the attachment degree of the polyester film and a base material is higher, and the texture and the performance of the base material are not influenced.

Description

Technical Field

[0001] The present invention relates to the technical field of polyester films, and particularly to an ultra-thin barrier polyester film and a preparation method thereof. Background Art

[0002] Polyester film, also known as polyester thin film, light sheet, polyester film, photosensitive paper, polyester film, benzene tin film, glassine paper, release film, is a kind of polymer plastic film. It is made of polyethylene terephthalate as raw material, extruded into a thick sheet, and then biaxially stretched into a film material. Because of its excellent comprehensive performance, it is more and more popular among consumers. Polyester film, such as environmental protection film, PET film, opal film and other printing and packaging consumables, is widely used in the fiberglass industry, building materials industry, printing industry, medicine and health. Polyester film is a colorless and transparent film with luster, excellent performance, high rigidity, hardness and toughness, puncture resistance, friction resistance, high and low temperature resistance, chemical resistance, oil resistance, good airtightness and freshness preservation performance, and is one of the commonly used barrier composite film substrates. The thickness of polyester film is generally 12μm, and it is commonly used as the outer layer material for retort packaging, with good printability. Since China's production volume and technical level still cannot meet the market demand, some still need to rely on imports.

[0003] Polyester film is often used in the outer layer of flexible packaging, and is made into various common food, beverage, medicine and daily chemical product packages in life. It has excellent transparency and glossiness, non-toxic, good hygiene, good thermoforming performance. PET sheet is considered an ideal packaging material meeting environmental protection requirements, with excellent surface decoration performance, can be printed without surface treatment, is easy to press patterns, is easy to metallize, and has low surface resistivity after being coated with a polymer conductive polymer, and has good mechanical strength.

[0004] At present, the thickness of polyester film is relatively high, the adhesion with the substrate is low, covering on the substrate increases the thickness of the substrate, affecting the texture and performance of the substrate. In addition, the weather resistance and barrier properties of the polyester film covering on substrates such as solar cell backsheets are required to be very high. Therefore, it is very necessary to invent a high-barrier ultra-thin polyester film. Summary of the Invention

[0005] An ultra-thin barrier polyester film, characterized in that the high-barrier ultra-thin polyester film is divided into upper and lower layers; the upper layer is an olefin-olefin alcohol copolymer or an ethylene-acrylic acid copolymer or a nano-silica modified ethylene-vinyl alcohol copolymer, and the lower layer preparation raw materials include a dispersion liquid of non-metallic materials and polyethylene naphthalate.

[0006] The present invention is further provided that when the upper layer is an olefin-olefin alcohol copolymer, the molecular weight of the olefin is 20-80.

[0007] The present invention is further provided that the upper layer is an ethylene-vinyl alcohol copolymer.

[0008] The present invention is further configured such that the lower layer is a mixture of a dispersion of a carbon material - surfactant aqueous solution and polyethylene naphthalate.

[0009] The present invention is further configured such that the carbon material includes one of carbon nanotubes, graphene, graphite, carbon fiber, porous activated carbon, carbon black, diamond, and fullerene.

[0010] The present invention is further configured such that the carbon material is graphene or carbon nanotubes.

[0011] The present invention is further configured such that when the carbon material is graphene, the surfactant aqueous solution includes an anionic surfactant aqueous solution or the surfactant aqueous solution is a sodium dodecyl sulfonate aqueous solution, and the lower layer is a mixture of a dispersion of graphene - sodium dodecyl sulfonate aqueous solution and polyethylene naphthalate.

[0012] The present invention is further configured such that when the carbon material is carbon nanotubes, the surfactant is polyvinylpyrrolidone, and the lower layer is a mixture of a carbon nanotube - polyvinylpyrrolidone dispersion and polyethylene naphthalate.

[0013] The present invention is further configured such that the lower layer is a mixture of polyethylene naphthalate, a dispersion of graphene - sodium dodecyl sulfonate aqueous solution, and montmorillonite.

[0014] A method for preparing an ultra - thin barrier polyester film for preparing the high - barrier ultra - thin polyester film, characterized by comprising the following steps:

[0015] Step 1: Prepare a dispersion of a non - metallic material. Mix the non - metallic material with the dispersion liquid, and under room - temperature conditions, stir with a high - speed stirrer for 2 h to 4 h, and then disperse ultrasonically for 2 h to 4 h to obtain a dispersion of the non - metallic material with a concentration of 2000 ppm to 10000 ppm.

[0016] Step 2: Melt - mix the dispersion of the non - metallic material obtained in Step 1 and polyethylene naphthalate in a twin - screw extruder and evacuate. The screw speed is (15 - 30) r / min, the melting temperature is 250 - 300 °C, the mixing time is 3 - 5 h, and the vacuum degree is 90 - 140 mmHg; evacuate until the mixture of the dispersion of the non - metallic material and polyethylene naphthalate is mixed evenly and there are no bubbles in the stirring.

[0017] Step 3: Continuously melt-mix the upper-layer raw materials, the dispersion of the non-metallic material obtained in Step 2, and the mixture of polyethylene naphthalate in a twin-screw extruder and evacuate to a vacuum. The screw speed is (15 - 30) r / min, the melting temperature is 250 - 300 °C, the mixing time is 3 - 5 h, and the vacuum degree is 90 - 140 mmHg; Evacuate until the upper-layer raw materials, the dispersion of the non-metallic material, and the mixture of polyethylene naphthalate are evenly mixed and there are no bubbles when stirred.

[0018] Step 4: Dry the mixture of the upper-layer raw materials, the dispersion of the non-metallic material, and the polyethylene naphthalate obtained in Step 3 and put it into an extruder. The extrusion temperature is 250 - 300 °C; The extruded thick sheet is transversely stretched 3 - 5 times at 80 - 100 °C, and the extruded thick sheet is longitudinally stretched 3 - 5 times at 80 - 100 °C. After transverse and longitudinal stretching, it is heat-set at 180 - 220 °C, wound and slit to obtain the finished product.

[0019] Advantages of the present invention: The high-barrier ultra-thin polyester film provided by the present invention has high barrier properties and good tolerance to environmental factors such as climate change and ultraviolet radiation. The thickness of the polyester film is better than that of common polyester films, and it has a higher adhesion to the substrate and does not affect the texture and performance of the substrate. Detailed implementation

[0020] An ultra-thin barrier polyester film, characterized in that the high-barrier ultra-thin polyester film is divided into upper and lower layers; The upper layer is an olefin-olefin alcohol copolymer or an ethylene-acrylic acid copolymer or a nano-silica-modified ethylene-vinyl alcohol copolymer, and the lower-layer preparation raw materials include a dispersion of a non-metallic material and polyethylene naphthalate.

[0021] The present invention is further provided that when the upper layer is an olefin-olefin alcohol copolymer, the molecular weight of the olefin is 20 - 80.

[0022] The present invention is further provided that the upper layer is an ethylene-vinyl alcohol copolymer.

[0023] The present invention is further provided that the lower layer is a mixture of a dispersion of a carbon material-surfactant aqueous solution and polyethylene naphthalate.

[0024] The present invention is further provided that the carbon material includes one of carbon nanotubes, graphene, graphite, carbon fiber, porous activated carbon, carbon black, diamond, fullerene.

[0025] The present invention is further provided that the carbon material is graphene or carbon nanotubes.

[0026] The present invention is further configured that when the carbon material is graphene, the surfactant aqueous solution includes an anionic surfactant aqueous solution or the surfactant aqueous solution is a sodium dodecyl sulfate aqueous solution, and the lower layer is a mixture of a dispersion of graphene - sodium dodecyl sulfate aqueous solution and polyethylene naphthalate.

[0027] The present invention is further configured that when the carbon material is carbon nanotubes, the surfactant is polyvinylpyrrolidone, and the lower layer is a mixture of a carbon nanotube - polyvinylpyrrolidone dispersion and polyethylene naphthalate.

[0028] The present invention is further configured that the lower layer is a mixture of polyethylene naphthalate, a dispersion of graphene - sodium dodecyl sulfate aqueous solution and montmorillonite.

[0029] A method for preparing an ultra - thin barrier polyester film for preparing the high - barrier ultra - thin polyester film, which is characterized by comprising the following steps:

[0030] Step 1: Prepare a dispersion of non - metallic materials. Mix the non - metallic materials with the dispersion liquid, and under room - temperature conditions, stir with a high - speed stirrer for 2 h to 4 h, and then perform ultrasonic dispersion for 2 h to 4 h to obtain a dispersion of non - metallic materials with a concentration of 2000 ppm to 10000 ppm.

[0031] Step 2: Melt - mix the dispersion of non - metallic materials obtained in Step 1 and polyethylene naphthalate in a twin - screw extruder and evacuate. The screw speed is (15 - 30) r / min, the melting temperature is 250 - 300 °C, the mixing time is 3 - 5 h, and the vacuum degree is 90 - 140 mmHg; evacuate until the mixture of the dispersion of non - metallic materials and polyethylene naphthalate is uniformly mixed and there are no bubbles in the stirring.

[0032] Step 3: Continue to melt - mix the upper - layer raw materials and the mixture of the dispersion of non - metallic materials and polyethylene naphthalate obtained in Step 2 in a twin - screw extruder and evacuate. The screw speed is (15 - 30) r / min, the melting temperature is 250 - 300 °C, the mixing time is 3 - 5 h, and the vacuum degree is 90 - 140 mmHg; evacuate until the upper - layer raw materials, the dispersion of non - metallic materials and the mixture of polyethylene naphthalate are uniformly mixed and there are no bubbles in the stirring.

[0033] Step 4: Dry the mixture of the upper - layer raw materials, the dispersion of non - metallic materials and polyethylene naphthalate obtained in Step 3 and then put it into an extruder, and the extrusion temperature is 250 - 300 °C; the extruded thick sheet is transversely stretched 3 - 5 times at 80 - 100 °C, the extruded thick sheet is longitudinally stretched 3 - 5 times at 80 - 100 °C, and after transverse and longitudinal stretching, it is heat - set at 180 - 220 °C, wound and slit to obtain the finished product.

[0034] The high-barrier ultra-thin polyester film provided by the present invention has high barrier properties, good tolerance to environmental factors such as climate change and ultraviolet radiation, the thickness of the polyester film is superior to that of common polyester films, and it has a higher degree of adhesion to the substrate, without affecting the texture and performance of the substrate.

[0035] The present invention will be specifically described below through examples. It is necessary to point out here that the following examples are only used to further illustrate the present invention and cannot be construed as limiting the protection scope of the present invention. Some non-essential improvements and adjustments made by those skilled in the art based on the above content of the present invention still fall within the protection scope of the present invention.

[0036] As described above, it is only a preferred embodiment of the present invention, and it is not a limitation of the invention in other forms. Any person skilled in the art may use the disclosed technical content to make changes or equivalent changes to equivalent embodiments, but as long as it does not depart from the technical solution content of the present invention, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present invention still fall within the protection scope of the technical solution of the present invention.

Claims

1. An ultra-thin barrier polyester film, characterized in that, The high-barrier ultra-thin polyester film is divided into upper and lower layers; the upper layer is an olefin-olefin alcohol copolymer, or an ethylene-acrylic acid copolymer, or an ethylene-vinyl alcohol copolymer modified with nano-silica, and the raw materials for preparing the lower layer include a dispersion of non-metallic materials and polyethylene naphthalate.

2. The ultra-thin barrier polyester film according to claim 1, wherein When the upper layer is an olefin-olefin alcohol copolymer, the molecular weight of the olefin is 20-80.

3. The ultra-thin barrier polyester film according to claim 1, wherein The upper layer is an ethylene-vinyl alcohol copolymer.

4. The ultra-thin barrier polyester film according to claim 1, wherein, The lower layer is a mixture of a dispersion of carbon material-surfactant aqueous solution and polyethylene naphthalate.

5. The ultra-thin barrier polyester film according to claim 4, characterized in that, The carbon material includes one of carbon nanotubes, graphene, graphite, carbon fiber, porous activated carbon, carbon black, diamond, fullerene.

6. The ultra-thin barrier polyester film according to claim 4, wherein The carbon material is graphene or carbon nanotubes.

7. The ultra-thin barrier polyester film according to claim 4, wherein When the carbon material is graphene, the surfactant aqueous solution includes an anionic surfactant aqueous solution or the surfactant aqueous solution is a sodium dodecyl sulfonate aqueous solution, and the lower layer is a mixture of a dispersion of graphene-sodium dodecyl sulfonate aqueous solution and polyethylene naphthalate.

8. The ultra-thin barrier polyester film according to claim 4, wherein When the carbon material is carbon nanotubes, the surfactant is polyvinylpyrrolidone, and the lower layer is a mixture of a carbon nanotube-polyvinylpyrrolidone dispersion and polyethylene naphthalate.

9. The ultra-thin barrier polyester film according to claim 1, wherein The lower layer is a mixture of polyethylene naphthalate, a dispersion of graphene-sodium dodecyl sulfonate aqueous solution and montmorillonite.

10. A preparation method of an ultra-thin barrier polyester film, which is used to prepare the high-barrier ultra-thin polyester film described in any one of claims 1-8, and is characterized in that, It includes the following steps: Step 1: Prepare a dispersion of non-metallic materials. Mix the non-metallic materials with the dispersion, and under room temperature conditions, stir with a high-speed stirrer for 2 h to 4 h, and then perform ultrasonic dispersion for 2 h to 4 h to obtain a dispersion of non-metallic materials with a concentration of 2000 ppm to 10000 ppm. Step 2: Melt-mix the dispersion of non-metallic materials obtained in Step 1 and polyethylene naphthalate in a twin-screw extruder and evacuate. The screw speed is (15-30) r / min, the melting temperature is 250-300 °C, the mixing time is 3-5 h, and the vacuum degree is 90-140 mmHg; evacuate until the mixture of the dispersion of non-metallic materials and polyethylene naphthalate is evenly mixed and there are no bubbles in the stirring. Step 3: Continuously melt-mix the upper layer raw materials and the mixture of the dispersion of non-metallic materials and polyethylene naphthalate obtained in Step 2 in a twin-screw extruder and evacuate. The screw speed is (15-30) r / min, the melting temperature is 250-300 °C, the mixing time is 3-5 h, and the vacuum degree is 90-140 mmHg; evacuate until the upper layer raw materials, the dispersion of non-metallic materials and the mixture of polyethylene naphthalate are evenly mixed and there are no bubbles in the stirring. Step 4: Dry the mixture of the upper layer raw materials, the dispersion of non-metallic materials and polyethylene naphthalate obtained in Step 3 and then put it into an extruder, and the extrusion temperature is 250-300 °C; the extruded thick sheet is transversely stretched 3-5 times at 80-100 °C, and the extruded thick sheet is longitudinally stretched 3-5 times at 80-100 °C. After transverse and longitudinal stretching, it is heat-set at 180-220 °C, wound and slit to obtain the finished product.