Preparation method of high-definition optical-grade polyester film

Abstract

The invention relates to a preparation method of a high-definition optical-grade polyester film, raw materials of an upper surface layer and a lower surface layer comprise film-grade polyester chips and optical-grade polyester anti-adhesion master batches, the film-grade polyester chips and the optical-grade polyester anti-adhesion master batches are mixed according to a certain proportion to form the high-definition optical-grade polyester film, and the addition amount of the anti-adhesion master batches is 2-5%; film-grade polyester chips and anti-sticking master batch are fed into each stock bin through a fan, after being uniformly mixed, the materials enter a pre-crystallizer to be pre-crystallized and dried, dried raw materials enter an extruder, are heated and melted in the extruder, pass through a metering pump, a filter and an adapter to reach a die head, flow out of a die lip, are pressed on a chilling roller through an adsorption system, and are subjected to extrusion molding to obtain a finished product. The cast sheet is rapidly cooled, the thick sheet enters the transverse drawing system to be transversely drawn after being longitudinally drawn, and finally the thick sheet passes through the traction system to the rolling system to form a large film roll. According to the high-definition base film processed through the method, the light transmittance of the product is 90%, the definition is 98% or above, the high-definition base film has the excellent optical performance such as high definition, and the viscosity of a post-processing product can be improved.

Description

Technical Field

[0001] The invention relates to the technical field of film manufacturing, and in particular to a method for preparing a high-definition optical-grade polyester film. Background Art

[0002] Biaxially oriented polyester (BOPET) film has excellent comprehensive properties, such as high mechanical strength, good optical properties, excellent barrier properties, acid and corrosion resistance, etc., and is widely used in electronic components, packaging, liquid crystal display, glass film, architectural decoration and other fields. In the past decade, although my country's BOPET film industry has developed rapidly, the main way for the development of this industry in my country is to increase production capacity, and too little investment has been made in the research of high-performance polyester film and differentiated polyester film. As a result, the production capacity of ordinary low-value-added polyester film is seriously oversupplied at this stage, while new high-end products, such as optical-grade BOPET film, are in short supply and basically rely on imports. Therefore, it is particularly urgent to develop such optical-grade high-transparency BOPET film. This must start from raw materials, processes, equipment and other aspects. In order to solve the shortcomings exposed by the anti-adhesion masterbatch that needs to be added to any BOPET film, especially to improve its optical properties and meet its performance requirements as an optical film. Summary of the invention

[0003] The object of the present invention is to provide a method for preparing a high-definition optical-grade polyester film to solve the above technical problems.

[0004] To achieve the above object, the present invention provides the following technical solutions:

[0005] A method for preparing a high-definition optical-grade polyester film, characterized in that the raw materials of the upper surface layer and the lower surface layer are composed of film-grade polyester chips and optical-grade polyester anti-adhesive masterbatch, the film-grade polyester chips and the anti-adhesive masterbatch are mixed in a certain proportion, and the addition amount of the anti-adhesive masterbatch is 2% to 5%; the blank chips and the anti-adhesive masterbatch are fed into each silo by a fan, and then automatically mixed according to a given proportion, after the mixing is uniform, they enter the pre-crystallizer for pre-crystallization, the raw materials enter the drying tower for drying after pre-crystallization, the dried raw materials enter the extruder, the raw materials are heated and melted in the extruder, and reach the die head after passing through a metering pump, a filter, and an adapter, and after flowing out from the die lip, they are pressed onto a chilling roller through an adsorption system to quickly cool the cast sheet, and the thick sheet enters the transverse drawing system for transverse stretching after longitudinal stretching, and finally passes through a traction system to a winding system to form a large film roll.

[0006] The present invention is further provided that the preparation method of the optical grade polyester anti-adhesive masterbatch is: A. pre-drying the anti-adhesive agent and the carrier resin polyethylene terephthalate; B. producing by a twin-screw extruder.

[0007] The present invention further provides that the mass fraction of the anti-sticking agent is 2-4%.

[0008] The present invention further provides that the anti-sticking agent is diatomaceous earth or silicon dioxide or organic microspheres or inorganic microspheres.

[0009] The present invention further arranges: a. the temperature of each zone of the extruder is 250-290° C.; b. the main engine speed is 200-450 r / min; c. the current is 300-400 A; d. 1-3 stages of vacuum exhaust, the vacuum degree is -0.05-0.1 MPa; e. the inorganic material is fed by a high-precision scale; f. the extruder screw original component adopts a low-shear high-dispersion special combination original component; g. a high-density filter screen is selected; the filter screen has five layers, the two surface layers use a mesh number of 40, the upper and lower second layers use a mesh number of 60, and the middle uses a 300-mesh filter screen combination.

[0010] The present invention is further arranged that the volume proportion of the upper surface layer and the lower surface layer is 10%.

[0011] The present invention further provides that the particle size of the anti-sticking agent is 4 μm-8 μm.

[0012] Beneficial effects of the present invention: The high-definition base film processed by the present invention has a product transmittance of 90% and a clarity of more than 98%, has excellent optical properties such as high definition, is beneficial to improving the viscosity of post-processed products, and meets the use of release protection in the electronic field and other fields. DETAILED DESCRIPTION

[0013] The following will explain the implementation methods of the present application in detail with reference to examples, so that the implementation process of how the present application uses technical means to solve technical problems and achieve technical effects can be fully understood and implemented accordingly.

[0014] A method for preparing a high-definition optical-grade polyester film, characterized in that the raw materials of the upper surface layer and the lower surface layer are composed of film-grade polyester chips and optical-grade polyester anti-adhesive masterbatch, the film-grade polyester chips and the anti-adhesive masterbatch are mixed in a certain proportion, and the addition amount of the anti-adhesive masterbatch is 2% to 5%; the blank chips and the anti-adhesive masterbatch are fed into each silo by a fan, and then automatically mixed according to a given proportion, after the mixing is uniform, they enter the pre-crystallizer for pre-crystallization, the raw materials enter the drying tower for drying after pre-crystallization, the dried raw materials enter the extruder, the raw materials are heated and melted in the extruder, and reach the die head after passing through a metering pump, a filter, and an adapter, and after flowing out from the die lip, they are pressed onto a chilling roller through an adsorption system to quickly cool the cast sheet, and the thick sheet enters the transverse drawing system for transverse stretching after longitudinal stretching, and finally passes through a traction system to a winding system to form a large film roll.

[0015] The present invention is further provided that the preparation method of the optical grade polyester anti-adhesive masterbatch is: A. pre-drying the anti-adhesive agent and the carrier resin polyethylene terephthalate; B. producing by a twin-screw extruder.

[0016] The present invention further provides that the mass fraction of the anti-sticking agent is 2-4%.

[0017] The present invention further provides that the anti-sticking agent is diatomaceous earth or silicon dioxide or organic microspheres or inorganic microspheres.

[0018] The present invention further arranges: a. the temperature of each zone of the extruder is 250-290° C.; b. the main engine speed is 200-450 r / min; c. the current is 300-400 A; d. 1-3 stages of vacuum exhaust, the vacuum degree is -0.05-0.1 MPa; e. the inorganic material is fed by a high-precision scale; f. the extruder screw original component adopts a low-shear high-dispersion special combination original component; g. a high-density filter screen is selected; the filter screen has five layers, the two surface layers use a mesh number of 40, the upper and lower second layers use a mesh number of 60, and the middle uses a 300-mesh filter screen combination.

[0019] The present invention is further arranged that the volume proportion of the upper surface layer and the lower surface layer is 10%.

[0020] The present invention further provides that the particle size of the anti-sticking agent is 4 μm-8 μm.

[0021] The following experiments were conducted for this application:

[0022] In this application, diatomite, silica, organic microspheres and inorganic microspheres are used as anti-adhesive agents. The effects of different anti-adhesive agents on the film are compared under the same conditions (film thickness is 30 μm, and 4% anti-adhesive masterbatch is added to the two surface layers). The experimental results show that: anti-adhesive performance: silica > diatomite > organic microspheres = inorganic microspheres, haze: silica > diatomite > organic microspheres = inorganic microspheres. The specific data are as follows:

[0023] Blank Silicon dioxide diatomite Organic microspheres Inorganic microspheres Adhesion force / g 210 33 35 49 45 Haze % 1.6 5.5 3.8 2.8 2.1

[0024] Taking silicon dioxide as an example, films with a thickness of 30 μm and a 4% addition amount on both surface layers were prepared to test the effect of different particle sizes on film performance.

[0025] The experimental results are as follows:

[0026] Haze 4μm 4.1 5μm 4.3 6μm 5.3 7μm 5.9 8μm 8.9

[0027] As the particle size of the anti-sticking agent increases, the haze of the film increases with the increase of particle size.

[0028] The high-definition base film processed by the present invention has a product transmittance of 90% and a clarity of more than 98%, has excellent optical properties such as high definition, is beneficial to improving the viscosity of post-processed products, and meets the use of release protection in the electronic field and other fields.

[0029] For example, certain words are used in the specification and claims to refer to specific components. Those skilled in the art should understand that hardware manufacturers may use different terms to refer to the same component. This specification and claims do not use differences in names as a way to distinguish components, but use differences in the functions of components as the criteria for distinction. For example, "including" mentioned throughout the specification and claims is an open term, so it should be interpreted as "including but not limited to". "Approximately" means that within an acceptable error range, those skilled in the art can solve the technical problem within a certain error range and basically achieve the technical effect.

[0030] It should be noted that the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a product or system including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such product or system. In the absence of more restrictions, the elements defined by the sentence "comprises a ..." do not exclude the existence of other identical elements in the product or system including the elements.

[0031] The above description shows and describes several preferred embodiments of the present invention, but as mentioned above, it should be understood that the present invention is not limited to the form disclosed herein, and should not be regarded as excluding other embodiments, but can be used in various other combinations, modifications and environments, and can be modified within the scope of the invention concept described herein through the above teachings or the technology or knowledge of the relevant field. Changes and variations made by those skilled in the art do not depart from the spirit and scope of the present invention, and should be within the scope of protection of the claims attached to the present invention.

Claims

1. A method for preparing a high-definition optical grade polyester film, characterized in that: The raw materials of the upper surface layer and the lower surface layer are film-grade polyester chips and optical-grade polyester anti-adhesive masterbatch. The film-grade polyester chips and the anti-adhesive masterbatch are mixed in a certain proportion, and the addition amount of the anti-adhesive masterbatch is 2% to 5%. The blank chips and the anti-adhesive masterbatch are fed into each silo through a fan, and then automatically mixed according to a given proportion. After the mixing is uniform, they enter the pre-crystallizer for pre-crystallization. After the pre-crystallization, the raw materials enter the drying tower for drying. The dried raw materials enter the extruder. The raw materials are heated and melted in the extruder, and reach the die head after passing through a metering pump, a filter, and an adapter. After flowing out from the die lip, they are pressed onto a chilled roller through an adsorption system to quickly cool the cast sheet. After the thick sheet is longitudinally stretched, it enters the transverse drawing system for transverse stretching, and finally passes through the traction system to the winding system to form a large film roll.

2. The method for preparing a high-definition optical grade polyester film according to claim 1, characterized in that: The preparation method of the optical grade polyester anti-adhesive masterbatch is as follows: A. pre-drying the anti-adhesive agent and the carrier resin polyethylene terephthalate; B. producing by a twin-screw extruder.

3. The method for preparing a high-definition optical grade polyester film according to claim 1, characterized in that: The mass fraction of the anti-sticking agent is 2-4%.

4. The method for preparing a high-definition optical grade polyester film according to claim 2, characterized in that: The anti-sticking agent is diatomaceous earth or silicon dioxide or organic microspheres or inorganic microspheres.

5. The method for preparing a high-definition optical grade polyester film according to claim 1, characterized in that: a. The temperature of each zone of the extruder is 250~290℃; b. The main engine speed is 200~450r / min; c. The current is 300~400A; d. 1~3 stages of vacuum exhaust, vacuum degree -0.05~0.1MPa; e. Inorganic materials are fed by high-precision weighing; f. The extruder screw components are low-shear and high-dispersion special combination components; g. High-density filter is used; the filter is five-layer, the two surface layers are 40 mesh, the upper and lower second layers are 60 mesh, and the middle layer is 300 mesh filter combination.

6. The method for preparing a high-definition optical grade polyester film according to claim 1, characterized in that: The volume proportion of the upper surface layer and the lower surface layer is 10%.

7. The method for preparing a high-definition optical grade polyester film according to claim 4, characterized in that: The particle size of the anti-sticking agent is 5 μm-8 μm.