CN-116445092-B - Polyester film and preparation method thereof

Abstract

The invention provides a polyester film which comprises, by mass, 80% -88% of polyester and 12% -20% of a second barrier additive, wherein the second barrier additive is a first barrier additive modified by an organic ultraviolet barrier, the first barrier additive comprises, by mass, 52% -58% of nano silicon dioxide, 25% -30% of nano vanadium dioxide and 14% -20% of nano titanium dioxide, and the first functional layer and the second functional layer comprise, by mass, 65% -73% of polyester, 24% -32% of an anti-adhesion master batch and 3% -5% of a second barrier additive. The invention is helpful for improving the production efficiency, and the heat insulation and ultraviolet ray insulation performances are slightly reduced, but the process cost is low, so that the invention is very suitable for batch production in factories.

Inventors

• ZHOU BO

Assignees

• 浙江华清新材料有限公司

Dates

Publication Date

20260512

Application Date

20230414

Claims (3)

1. 1. The polyester film comprises a first functional layer, a barrier core layer, a second functional layer, an EVA bonding layer, a PET base film layer and an adhesive layer which are sequentially arranged, and is characterized in that: The barrier core layer comprises 80-88% of polyester and 12-20% of second barrier additive, wherein the second barrier additive is a first barrier additive modified by an organic ultraviolet barrier, and the preparation method of the second barrier additive comprises the steps of adding the organic ultraviolet barrier with the mass being 2-5 times of that of the first barrier additive into the first barrier additive, and uniformly mixing; the first barrier additive comprises the following components, by mass, 52% -58% of nano silicon dioxide, 25% -30% of nano vanadium dioxide and 14% -20% of nano titanium dioxide; The first functional layer and the second functional layer have the same components and comprise 65-73% of polyester, 24-32% of anti-blocking master batch and 3-5% of second blocking additive by mass percent; the thickness of the first functional layer is 5-8 mu m, and the thickness of the barrier core layer is 10-15 mu m; the organic ultraviolet blocking material comprises 60-75% of benzotriazole organic compound and 25-40% of bis-ethylhexyloxyphenol methoxyphenyl triazine by mass percent.
2. 2. A process for producing a polyester film according to claim 1, comprising the steps of: (1) Preparing a first functional layer (A layer), a barrier core layer (B layer) and a second functional layer (A layer) by adopting a three-layer coextrusion process to form an ABA three-layer coextrusion film; (2) Preparing a PET base film layer; (3) Coating an adhesive on the upper surface of the PET base film layer to form a bonding layer, and bonding the bonding layer with the second functional layer through the bonding layer; (4) And coating an adhesive on the lower surface of the PET base film layer to form an adhesive layer.
3. 3. The method for preparing the polyester film according to claim 2, wherein the first barrier additive is prepared by mixing nano silicon dioxide, nano vanadium dioxide and nano titanium dioxide in proportion, dispersing the mixture in ethanol, adding silane, and performing ball milling treatment on the obtained mixture, wherein the specific condition of the ball milling treatment is that the diameter of a grinding ball is 1-3mm, the rotating speed of the grinding ball is 800-1000r/min, and the ball milling time is not less than 6 hours.

Description

Polyester film and preparation method thereof Technical Field The invention belongs to the technical field of polyester films, and particularly relates to a polyester film used as an automobile window film and a preparation method thereof. Background The film for the front window and the rear window of the automobile can protect privacy, insulate heat, prevent sun and prevent ultraviolet rays to a certain extent. The traditional film pasted on the front window of the automobile is a unidirectional light-transmitting transparent film, which can not influence the driving safety, but has insignificant heat insulation, sun protection and ultraviolet protection functions, so that the effects of reducing the temperature in the automobile, reducing the use of an air conditioner of the automobile, reducing the oil consumption and the like are declared in the industry. The Chinese patent application No. 201911170208.7 discloses a high-light-transmittance high-definition anti-explosion polyester film and a preparation method thereof (application publication No. CN 111004585A), wherein the polyester film sequentially comprises a film coating layer, a first functional layer, a core layer, a second functional layer, a metal heat insulation layer, a bonding layer, a PET base film layer and an adhesive layer. Compared with the existing polyester film, the polyester film has the advantages of high light transmittance, low haze, good ultraviolet resistance, high infrared blocking rate, high tensile strength, high peeling strength and excellent heat insulation performance and antiknock performance, and can provide more comfortable observation vision for a driver. The film is of an eight-layer structure and is prepared by firstly preparing a first functional layer, a core layer and a second functional layer to form a three-layer co-extrusion film, (2) preparing a coating layer on the first functional layer, (3) preparing a metal heat insulation layer on the second functional layer, (4) preparing a PET (polyethylene terephthalate) base film layer, (5) coating an adhesive on the upper surface of the PET base film layer to form an adhesive layer, and bonding the adhesive layer and the metal heat insulation layer together through the adhesive layer, and (6) coating the adhesive on the lower surface of the PET base film layer to form the adhesive layer. The multi-step operation is not only tedious, but also seriously affects the production efficiency. In addition, the formation of the coating layer adopts a PEVCD method, the metal heat insulation layer adopts a vacuum magnetic control sputtering technology, the high process cost is required, and the metal heat insulation layer also can block visible light, so that the industrial mass production is not facilitated. For this purpose, the present application is proposed. Disclosure of Invention In order to solve the defects in the prior art, the invention provides a polyester film and a preparation method thereof. The invention provides a polyester film, which comprises a first functional layer, a barrier core layer, a second functional layer, a bonding layer, a PET (polyethylene terephthalate) base film layer and an adhesive layer which are sequentially arranged; The barrier core layer comprises 80-88% of polyester and 12-20% of a second barrier additive, wherein the second barrier additive is a first barrier additive modified by an organic ultraviolet barrier, and the preparation method of the second barrier additive comprises the steps of adding the organic ultraviolet barrier with the mass 2-5 times that of the first barrier into the first barrier, and uniformly mixing; The first barrier additive comprises the following components, by mass, 52% -58% of nano silicon dioxide, 25% -30% of nano vanadium dioxide and 14% -20% of nano titanium dioxide; The first functional layer and the second functional layer comprise the following components, by mass, 65% -73% of polyester, 24% -32% of anti-blocking master batch and 3% -5% of second blocking additive, wherein the anti-blocking master batch is hollow spherical nano silicon dioxide (can be commercially available or can be self-made by referring to the prior art); The nano silicon dioxide, the nano vanadium dioxide and the nano titanium dioxide are preferably spherical or lamellar structures, and the spherical and lamellar structures have excellent reflection and diffuse reflection properties, so that the infrared light blocking performance can be enhanced on the microscopic scale, and the excellent organic ultraviolet blocking object modification effect can be obtained. The polyester comprises one or more of polyethylene terephthalate, polypropylene terephthalate and polybutylene terephthalate. The principle is that the silicon dioxide and the vanadium dioxide have excellent infrared blocking functions, the titanium dioxide has excellent ultraviolet blocking functions, the nano silicon dioxide, the nano vanadium dioxide and the nano tit