CN111993737A

CN111993737A - High-transmittance high-fog optical pre-coating film and preparation method thereof

Info

Publication number: CN111993737A
Application number: CN201910422703.6A
Authority: CN
Inventors: 金亚东; 杨承翰; 裴旺; 朱正平
Original assignee: Ningbo Solartron Technology Co Ltd
Current assignee: Ningbo Solartron Technology Co Ltd
Priority date: 2019-05-27
Filing date: 2019-05-27
Publication date: 2020-11-27

Abstract

The invention relates to the field of films, in particular to a high-transmittance high-haze optical pre-coating film and a preparation method thereof. The invention provides a high-transmittance high-haze film optical pre-coating film and a preparation method thereof, aiming at solving the problem that the pre-coating film is difficult to have the performances of high light transmittance and high haze at the same time. The optical precoating film substrate is of an ABA (Absolute ABA) multilayer co-extrusion structure, and inorganic or organic particles are added into the layer B; a layer of anti-reflection coating is coated on the surface of the layer A; the optical pre-coating film provided by the invention has the characteristics of high light transmittance and high haze, is coated and formed at one time in a stretching process, does not need rewinding, is simple in preparation method, high in speed, high in efficiency and low in cost, and is suitable for large-scale production.

Description

High-transmittance high-fog optical pre-coating film and preparation method thereof

Technical Field

The invention relates to the field of films, in particular to a high-transmittance high-haze optical pre-coating film and a preparation method thereof.

Background

Biaxially oriented polyester films have a number of excellent properties: high mechanical strength, excellent optical performance, good electrical insulation performance, good barrier performance, good temperature resistance, chemical corrosion resistance, good dimensional stability and the like, thus being widely applied to the fields of packaging, electronic and electric products, photography, magnetic products and the like. Polyester films are required to have higher optical properties than packaging or electronic and electrical applications, and are required to have more excellent optical properties in addition to mechanical strength, thermal stability, and the like. For example, in the case of a diffusion film and a brightness enhancement film used in a liquid crystal display panel, a polyester film as a base film is required to have a light transmittance of 90% or more, and even 94% or more as a base film for a liquid crystal display protective film.

In the production of common polyester films, in order to meet the requirement of processability, the polyester surface layer must contain a small amount of fine solid particles to play the role of anti-blocking of the winding and unwinding of the film. Such inorganic particles are generally silica, calcium phosphate, kaolin, etc., and the particle diameter is generally between 1 and 6 μm. The traditional method is that inorganic particles are added into a polyester raw material to prepare a master batch chip, and then the inorganic particles are added into the whole film (single-layer extrusion) or the film surface layer (A layer in ABA three-layer co-extrusion) in a master batch adding mode. The addition of these inorganic particles solves the problem of blocking resistance of the film surface, but inevitably prevents part of the light from causing a decrease in light transmittance.

The surface layer of the film is precoated with a water-based coating in an on-line precoating mode, and the optical performance of the precoating film is generally better because the coating can be very thin (50-200nm), the particle size of anti-adhesion particles can be smaller, and the thin coating has a certain antireflection function.

The on-line coating does not need rewinding, and the coating is thin and uniform, and has high speed, high efficiency and low cost. At present, the market of domestic optical films is rapidly increased, the proportion of the optical pre-coating films is gradually increased, and in order to save the manufacturing cost, a plurality of optical pre-coating film manufacturers adopt the high-haze pre-coating films to process so as to replace and reduce other films, thereby achieving the purpose of reducing the cost. The haze of the optical pre-coating film on the domestic market is generally lower at present. The higher the haze is, the greater the production difficulty is, so the prepared precoating film with high light transmission and high haze has certain market prospect.

Disclosure of Invention

The invention provides a high-transmittance high-haze film optical pre-coating film and a preparation method thereof, aiming at solving the problem that the pre-coating film is difficult to have the performances of high light transmittance and high haze at the same time. The optical pre-coating film provided by the invention is multi-layer co-extrusion, is coated on line in the stretching process for one-step forming, does not need rewinding, and has the advantages of thin and uniform coating, high speed, high efficiency and low cost.

The invention adopts the following technical scheme:

the invention provides a high-transmittance high-fog optical pre-coating film and a preparation method thereof, which are characterized in that: the high-transmittance high-haze optical pre-coating film comprises a PET (polyethylene terephthalate) base material, the thickness of the base material is 25-300 mu m, the base material is an ABA (abscisic acid) three-layer co-extrusion structure, and the thickness of a base material B layer is 5-60 mu m; inorganic or organic particles are added into the base material layer B; the two sides of the base material are pre-coated with a polyester coating on line, and the polyester pre-coating contains inorganic particles.

Further, the high-transmittance high-haze optical pre-coating film is characterized in that the substrate B layer particles are one or a combination of two of SiO2, BaSO4 and PMMA; the particle size of the particles is 2-8 μm.

Furthermore, the high-transmittance high-haze optical precoating film is characterized in that the two sides of the base material are precoated with polyester coatings containing inorganic particles, the inorganic particles are one or the combination of two of SiO2 and BaSO4, and the diameter of the inorganic particles is 0.1-0.4 μm.

Further, the high-transmittance high-haze optical precoating film is characterized in that the thickness of the precoating layer is 0.05-0.5 μm.

Furthermore, the high-transmittance high-haze optical pre-coating film is characterized in that the base material is prepared by three-layer co-extrusion through two extruders ABA, and the pre-coating preparation method is that a wire rod or a gravure roller is used for coating a layer of water-based polyester coating on two sides in the base material preparation process before transverse drawing after longitudinal drawing.

The optical pre-coating film provided by the invention has the characteristics of high light transmittance and high haze, and is simple in production process, high in efficiency and low in cost.

Drawings

FIG. 1 is a schematic structural view of a high-transmittance high-haze optical precoating film according to the present invention;

in the figure: 1, A layer of PET, 2, B layer of PET, 3, surface precoating, 4, B layer added particles and 5, nano inorganic particles in the precoating.

Detailed Description

In order to make the technical scheme and technical effects of the present invention more understandable, the present invention is described in detail below with reference to embodiments, wherein the raw material for preparing the polyester film is chinese petrochemical PET chips; the water-based resin can be water-soluble polyacrylate, water-soluble polyurethane and water-soluble sulfonated polyester.

The percentages stated in the examples are by weight.

The invention provides a high-transmittance high-fog optical pre-coating film and a preparation method thereof, wherein the preparation method comprises the following steps:

(1) preparation of coating liquid

The water-based resin is MD1200 polyester resin produced by TOYOBO company, the curing agent is Elastlon BN-4 blocked isocyanate curing agent produced by the first industrial pharmaceutical company, the additive is NYSCOL 2034DI nano colloidal silica produced by Ika chemical company, and the rest is deionized water. The preparation process of the coating liquid comprises the following steps: 8.5 percent of water-based resin, 1.5 percent of curing agent, 1.0 percent of colloidal silica additive and 89.0 percent of deionized water are mixed and stirred evenly and filtered for standby.

(2) Process for preparing polyester film

The polyester resin used in the examples was medium petrochemical PET polyester chip.

The polyester film base material is prepared on a polyester film stretching production line produced by Mitsubishi heavy industry company, Japan Steel works or Brukna company, Germany. The preparation steps of the film are as follows: melting polyester raw materials by two twin-screw extruders, mixing the polyester raw materials by a die head junction station to form an ABA three-layer structure extrusion casting sheet, longitudinally stretching the obtained thick sheet by 3 times at 100 ℃, performing double-sided coating by using prepared coating liquid, drying at 98 ℃ in a transverse preheating section, transversely stretching by 3.2 times at 104 ℃, performing heat setting treatment at 230 ℃, cutting edges and rolling after cooling, and finally preparing the high-transparency high-haze optical polyester film with the thickness of 25-300 mu m.

The optical properties of the polyester film obtained were evaluated by measuring the light transmittance and haze according to GB/T2410-2008 on an EEL 57D haze Meter of Diffusion, UK.

Example 1

The optical pre-coating film provided by the invention has the total thickness of 150 mu m, wherein the total thickness of the A layer is 120 mu m, and the thickness of the B layer is 30 mu m; the B layer contains 0.5% of SiO₂Particles having a particle size of 2 μm; the thickness of the precoat dry film was 0.2. mu.m. The relevant properties are shown in Table 1.

Example 2

The optical pre-coating film provided by the invention has the total thickness of 150 mu m, wherein the total thickness of the A layer is 120 mu m, and the thickness of the B layer is 30 mu m; the B layer contains 1.0% of SiO₂Particles having a particle size of 2 μm; the thickness of the precoat dry film was 0.2. mu.m. The relevant properties are shown in Table 1.

Example 3

The optical pre-coating film provided by the invention has the total thickness of 150 mu m, wherein the total thickness of the A layer is 120 mu m, and the thickness of the B layer is 30 mu m; the B layer contains 2.0% of SiO₂Particles having a particle size of 2 μm; the thickness of the precoat dry film was 0.2. mu.m. The relevant properties are shown in Table 1.

Example 4

The optical pre-coating film provided by the invention has the total thickness of 150 mu m, wherein the total thickness of the A layer is 120 mu m, and the thickness of the B layer is 30 mu m; the B layer contains 3.0% of SiO₂Particles having a particle size of 2 μm; the thickness of the precoat dry film was 0.2. mu.m. The relevant properties are shown in Table 1.

Example 5

The optical pre-coating film provided by the invention has the total thickness of 150 mu m, wherein the total thickness of the A layer is 120 mu m, and the thickness of the B layer is 30 mu m; the B layer contains 5.0% of SiO₂Particles having a particle size of 2 μm; the thickness of the precoat dry film was 0.2. mu.m. The relevant properties are shown in Table 1.

Example 6

The optical pre-coating film provided by the invention has the total thickness of 150 mu m, wherein the total thickness of the A layer is 120 mu m, and the thickness of the B layer is 30 mu m; the layer B contains 0.5% of PMMA particles with the particle size of 2 mu m; the thickness of the precoat dry film was 0.2. mu.m. The relevant properties are shown in Table 1.

Example 7

The optical pre-coating film provided by the invention has the total thickness of 150 mu m, wherein the total thickness of the A layer is 120 mu m, and the thickness of the B layer is 30 mu m; the B layer contains 0.5% of SiO₂Particles and 0.5% of PMMA particles, the particle size is 2 μm; the thickness of the precoat dry film was 0.2. mu.m. The relevant properties are shown in Table 1.

Example 8

The optical pre-coating film provided by the invention has the total thickness of 150 mu m, wherein the total thickness of the A layer is 120 mu m, and the thickness of the B layer is 30 mu m; the B layer contains 1.0% of SiO₂Particles and 1.0% of PMMA particles, the particle size is 2 μm; the thickness of the precoat dry film was 0.2. mu.m. The relevant properties are shown in Table 1.

Example 9

The optical pre-coating film provided by the invention has the total thickness of 150 mu m, wherein the total thickness of the A layer is 120 mu m, and the thickness of the B layer is 30 mu m; the B layer contains 2.0% of SiO₂Particles and 2.0% of PMMA particles with the particle size of 2 μm; the thickness of the precoat dry film was 0.2. mu.m. The relevant properties are shown in Table 1.

Example 10

The optical pre-coating film provided by the invention has the total thickness of 150 mu m, wherein the total thickness of the A layer is 120 mu m, and the thickness of the B layer is 30 mu m; layer B contains 2.0% BaSO₄Particles and 2.0% of PMMA particles with the particle size of 2 μm; the thickness of the precoat dry film was 0.2. mu.m. The relevant properties are shown in Table 1.

TABLE 1

Example 11

The optical pre-coating film provided by the invention has the total thickness of 150 mu m, wherein the total thickness of the A layer is 120 mu m, and the thickness of the B layer is 30 mu m; the B layer contains 0.5% of SiO₂Particles having a particle diameter of 8 μm; the thickness of the precoat dry film was 0.2. mu.m. The relevant properties are shown in Table 2.

Example 12

The optical pre-coating film provided by the invention has the total thickness of 150 mu m, wherein the total thickness of the A layer is 120 mu m, and the thickness of the B layer is 30 mu m; the B layer contains 1.0% of SiO₂Particles, granulesThe diameter is 8 mu m; the thickness of the precoat dry film was 0.2. mu.m. The relevant properties are shown in Table 2.

Example 13

The optical pre-coating film provided by the invention has the total thickness of 150 mu m, wherein the total thickness of the A layer is 120 mu m, and the thickness of the B layer is 30 mu m; the B layer contains 2.0% of SiO₂Particles having a particle diameter of 8 μm; the thickness of the precoat dry film was 0.2. mu.m. The relevant properties are shown in Table 2.

Example 14

The optical pre-coating film provided by the invention has the total thickness of 150 mu m, wherein the total thickness of the A layer is 120 mu m, and the thickness of the B layer is 30 mu m; the B layer contains 3.0% of SiO₂Particles having a particle diameter of 8 μm; the thickness of the precoat dry film was 0.2. mu.m. The relevant properties are shown in Table 2.

Example 15

The optical pre-coating film provided by the invention has the total thickness of 150 mu m, wherein the total thickness of the A layer is 120 mu m, and the thickness of the B layer is 30 mu m; the B layer contains 5.0% of SiO₂Particles having a particle diameter of 8 μm; the thickness of the precoat dry film was 0.2. mu.m. The relevant properties are shown in Table 2.

Example 16

The optical pre-coating film provided by the invention has the total thickness of 150 mu m, wherein the total thickness of the A layer is 120 mu m, and the thickness of the B layer is 30 mu m; the layer B contains 0.5% of PMMA particles with the particle size of 8 mu m; the thickness of the precoat dry film was 0.2. mu.m. The relevant properties are shown in Table 2.

Example 17

The optical pre-coating film provided by the invention has the total thickness of 150 mu m, wherein the total thickness of the A layer is 120 mu m, and the thickness of the B layer is 30 mu m; the B layer contains 0.5% of SiO₂Particles and 0.5% of PMMA particles, the particle size is 8 μm; the thickness of the precoat dry film was 0.2. mu.m. The relevant properties are shown in Table 2.

Example 18

The optical pre-coating film provided by the invention has the total thickness of 150 mu m, wherein the total thickness of the A layer is 120 mu m, and the thickness of the B layer is 30 mu m; the B layer contains 1.0% of SiO₂Particles and 1.0% of PMMA particles, the particle size is 8 μm; the thickness of the precoat dry film was 0.2. mu.m. The relevant properties are shown in Table 2.

Example 19

The invention providesAn optical pre-coating film with a total thickness of 150 μm, wherein the total thickness of the A layer is 120 μm, and the thickness of the B layer is 30 μm; the B layer contains 2.0% of SiO₂Particles and 2.0% of PMMA particles with the particle size of 8 μm; the thickness of the precoat dry film was 0.2. mu.m. The relevant properties are shown in Table 2.

Example 20

The optical pre-coating film provided by the invention has the total thickness of 150 mu m, wherein the total thickness of the A layer is 120 mu m, and the thickness of the B layer is 30 mu m; layer B contains 2.0% BaSO₄Particles and 2.0% of PMMA particles with the particle size of 8 μm; the thickness of the precoat dry film was 0.2. mu.m. The relevant properties are shown in Table 2.

TABLE 2

Example 21

The optical pre-coating film provided by the invention has the total thickness of 150 mu m, wherein the total thickness of the A layer is 120 mu m, and the thickness of the B layer is 30 mu m; the B layer contains 0.5% of SiO₂Particles having a particle size of 2 μm; the thickness of the precoat dry film was 0.2. mu.m. The relevant properties are shown in Table 3.

Example 22

The optical pre-coating film provided by the invention has the total thickness of 150 mu m, wherein the total thickness of the A layer is 120 mu m, and the thickness of the B layer is 30 mu m; the B layer contains 1.0% of SiO₂Particles having a particle size of 2 μm; the thickness of the precoat dry film was 0.2. mu.m. The relevant properties are shown in Table 3.

Example 23

The optical pre-coating film provided by the invention has the total thickness of 150 mu m, wherein the total thickness of the A layer is 120 mu m, and the thickness of the B layer is 30 mu m; the B layer contains 2.0% of SiO₂Particles having a particle size of 2 μm; the thickness of the precoat dry film was 0.2. mu.m. The relevant properties are shown in Table 3.

Example 24

The optical pre-coating film provided by the invention has the total thickness of 150 mu m, wherein the total thickness of the A layer is 120 mu m, and the thickness of the B layer is 30 mu m; the B layer contains 3.0% of SiO₂Particles having a particle size of 2 μm; the thickness of the precoat dry film was 0.2. mu.m. The relevant properties are shown in Table 3.

Example 25

The optical pre-coating film provided by the invention has the total thickness of 150 mu m, wherein the total thickness of the A layer is 120 mu m, and the thickness of the B layer is 30 mu m; the B layer contains 5.0% of SiO₂Particles having a particle size of 2 μm; the thickness of the precoat dry film was 0.2. mu.m. The relevant properties are shown in Table 3.

Example 26

The optical pre-coating film provided by the invention has the total thickness of 150 mu m, wherein the total thickness of the A layer is 120 mu m, and the thickness of the B layer is 30 mu m; the layer B contains 0.5% of PMMA particles with the particle size of 2 mu m; the thickness of the precoat dry film was 0.2. mu.m. The relevant properties are shown in Table 3.

Example 27

The optical pre-coating film provided by the invention has the total thickness of 150 mu m, wherein the total thickness of the A layer is 120 mu m, and the thickness of the B layer is 30 mu m; the B layer contains 0.5% of SiO₂Particles and 0.5% of PMMA particles, the particle size is 2 μm; the thickness of the precoat dry film was 0.2. mu.m. The relevant properties are shown in Table 3.

Example 28

The optical pre-coating film provided by the invention has the total thickness of 150 mu m, wherein the total thickness of the A layer is 120 mu m, and the thickness of the B layer is 30 mu m; the B layer contains 1.0% of SiO₂Particles and 1.0% of PMMA particles, the particle size is 2 μm; the thickness of the precoat dry film was 0.2. mu.m. The relevant properties are shown in Table 3.

Example 29

The optical pre-coating film provided by the invention has the total thickness of 150 mu m, wherein the total thickness of the A layer is 120 mu m, and the thickness of the B layer is 30 mu m; the B layer contains 2.0% of SiO₂Particles and 2.0% of PMMA particles with the particle size of 2 μm; the thickness of the precoat dry film was 0.2. mu.m. The relevant properties are shown in Table 3.

Example 30

The optical pre-coating film provided by the invention has the total thickness of 150 mu m, wherein the total thickness of the A layer is 120 mu m, and the thickness of the B layer is 30 mu m; layer B contains 2.0% BaSO₄Particles and 2.0% of PMMA particles with the particle size of 2 μm; the thickness of the precoat dry film was 0.2. mu.m. The relevant properties are shown in Table 3.

TABLE 3

Example 31

The optical pre-coating film provided by the invention has a total thickness of 25 mu m, wherein the total thickness of the A layer is 20 mu m, and the thickness of the B layer is 5 mu m; the B layer contains 2.0% of SiO₂Particles having a particle size of 5 μm; the thickness of the precoat dry film was 0.2. mu.m. The relevant properties are shown in Table 4.

Example 32

The optical pre-coating film provided by the invention has a total thickness of 25 mu m, wherein the total thickness of the A layer is 20 mu m, and the thickness of the B layer is 5 mu m; the B layer contains 2.0% of SiO₂Particles and 2.0% of PMMA particles, the particle size is 5 μm; the thickness of the precoat dry film was 0.2. mu.m. The relevant properties are shown in Table 4.

Example 33

The optical pre-coating film provided by the invention has a total thickness of 25 mu m, wherein the total thickness of the A layer is 20 mu m, and the thickness of the B layer is 5 mu m; the B layer contains 5.0% of SiO₂Particles having a particle size of 5 μm; the thickness of the precoat dry film was 0.2. mu.m. The relevant properties are shown in Table 4.

TABLE 4

Example 34

The optical pre-coating film provided by the invention has the total thickness of 300 mu m, wherein the total thickness of the layer A is 240 mu m, and the thickness of the layer B is 60 mu m; the B layer contains 2.0% of SiO₂Particles having a particle size of 5 μm; the thickness of the precoat dry film was 0.2. mu.m. The relevant properties are shown in Table 5.

Example 35

The optical pre-coating film provided by the invention has a total thickness of 25 μm, wherein the total thickness of the A layer is 240 μm, and the thickness of the B layer is 60 μm; the B layer contains 2.0% of SiO₂Particles and 2.0% of PMMA particles, the particle size is 5 μm; the thickness of the precoat dry film was 0.2. mu.m. The relevant properties are shown in Table 5.

Example 36

The invention provides an optical precoating film, and the total thickness of the precoating film is 25μ m, wherein the total thickness of the A layer is 240 μm, and the thickness of the B layer is 60 μm; the B layer contains 5.0% of SiO₂Particles having a particle size of 5 μm; the thickness of the precoat dry film was 0.2. mu.m. The relevant properties are shown in Table 5.

TABLE 5

As can be seen from the data presented in the above Table of examples 1-36, the precoat film provided by the present invention is characterized by high light transmittance and high haze. Among them, the precoat film provided in example 30 has the best overall performance; in particular, the precoat film provided in example 6 had the highest light transmittance, and the precoat film provided in example 36 had the highest haze.

The above description is only a preferred embodiment of the present invention, and is not intended to limit the scope of the present invention. All equivalent changes and modifications made according to the disclosure of the present invention are covered by the scope of the claims of the present invention.

Claims

1.A high-transmittance high-fog optical pre-coating film and a preparation method thereof are characterized in that: the high-transmittance high-haze optical pre-coating film comprises a PET (polyethylene terephthalate) base material, the thickness of the base material is 25-300 mu m, the base material is an ABA (abscisic acid) three-layer co-extrusion structure, and the thickness of a base material B layer is 5-60 mu m; inorganic or organic particles are added into the base material layer B; the two sides of the base material are pre-coated with a polyester coating on line, and the polyester pre-coating contains inorganic particles.

2. The pre-coating film of claim 1, wherein the substrate B layer additive particles are one or a combination of two of SiO2, BaSO4 and PMMA; the particle size of the particles is 2-8 μm.

3. The high-haze optical precoating film according to claim 1, wherein the polyester-based precoating coating on both sides of the substrate comprises inorganic particles, the inorganic particles are one or two of SiO2 and BaSO4, and the diameter of the inorganic particles is 0.1-0.4 μm.

4. The high haze optical precoat film according to claim 1, wherein the precoat layer thickness is 0.05-0.5 μm.

5. The preparation method of the high-transparency high-haze optical precoating film according to claim 1, wherein the base material is prepared by ABA three-layer co-extrusion of two extruders, and the precoating layer is prepared by coating a layer of water-based polyester coating on both sides by using a wire rod or a gravure roller coating mode in the preparation process of the base material and before transverse drawing after longitudinal drawing.