AG coating liquid, preparation method and polaroid applying AG coating liquid

Abstract

The invention relates to an AG coating liquid, a preparation method and a polaroid applying the AG coating liquid, acrylic particles are added into the AG coating liquid, so that the anti-dazzle performance of the coating liquid is improved, a defoaming agent is further added, and bubbles generated in the preparation process of the coating liquid are inhibited. The invention further provides a preparation method of the AG coating liquid, in the preparation process, the methylbenzene mother liquor, the defoaming agent and the final mixed solution are filtered through a filter, bubbles in the AG coating liquid are further removed, and the situation that the coating effect is affected due to the fact that the bubbles cannot be rapidly and effectively discharged during online coating is avoided. The AG coating liquid disclosed by the invention has excellent stability and dispersity, is not easy to generate a condensation phenomenon and is easy to coat, and the polaroid prepared from the AG coating liquid has excellent optical performance.

Description

Technical Field

[0001] The present invention belongs to the technical field of optical materials, and in particular relates to an AG coating liquid, a preparation method and a polarizer using the same. Background Art

[0002] In liquid crystal display imaging technology, polarizers, as core raw materials, play a key role in converting natural light into polarized light and improving light utilization efficiency. It consists of a multi-layer structure including PVA film, upper and lower substrates, protective film, release film and pressure-sensitive adhesive, and is widely used in terminal consumer electronic products such as televisions, computers, mobile phones and other liquid crystal imaging fields. The two polarizers in the liquid crystal display module are attached to both sides of the glass substrate, responsible for converting the backlight beam into polarized light and analyzing the polarized light after liquid crystal electrical modulation to produce light and dark contrast, thereby forming a display screen. Polarized light is a necessary condition for imaging of liquid crystal display modules. The absence of any polarizer will cause the module to be unable to display images. Given the fragility of the PVA layer material, it is particularly important to protect both ends.

[0003] At present, PMMA film (polymethyl methacrylate film, commonly known as acrylic film or organic glass film) is widely used as the upper and lower protective film of polarizing plates due to its excellent weather resistance, high transmittance and other characteristics. In order to enhance the fit between PMMA film and PVA film and prevent the film materials from sticking to each other, a layer of Primer coating is often applied on the PMMA film. In addition, in order to improve the anti-glare and anti-mapping properties of PMMA film, a functional coating is added to the reverse side of the Primer coating, and AG (Anti-Glare) liquid is prepared by adding specific particles to the surface hardening coating, so that the PMMA film has excellent anti-glare performance and clarity after coating with AG liquid.

[0004] However, in the process of making and filling the coating liquid, the generation of bubbles has become a problem that needs to be solved urgently. Specifically, a large number of bubbles will be generated during the mixing and gluing cycle of the colloid. At the same time, the rapid increase in the viscosity of the colloid will also cause bubbles to be generated, and these bubbles are difficult to remove from the filling barrel. The presence of bubbles not only reduces the quality of the coating liquid, but also affects the coating effect. When the coating liquid containing bubbles is applied to the surface of the PMMA film, defects will occur, resulting in black streaks after the polarizer is bonded, which seriously affects the performance and use of the polarizer.

[0005] The traditional defoaming method relies on the liquid supply pump to pump the liquid, circulate and filter the AG liquid through a filter with a pore size of 4.5um and discharge the liquid containing bubbles. After the glue is applied on the line, secondary defoaming of the pipeline reflux is required. This method is complicated to operate, time-consuming and liquid-consuming, and is not conducive to improving production efficiency. Therefore, it is particularly urgent and important to develop and produce an AG coating liquid without bubbles. Summary of the invention

[0006] The purpose of the present invention is to overcome the deficiencies in the prior art and to provide an AG coating liquid, a preparation method and a polarizer using the same.

[0007] To achieve the above object, the present invention adopts the following technical solutions:

[0008] The present application provides an AG coating solution, which comprises the following components by weight:

[0009]

[0010] As a further improvement of the present application, the main resin is acrylic resin, and the auxiliary resin is 2-(4-hydroxybutyl) acrylate.

[0011] As a further improvement of the present application, the acrylic particles are copolymers of methyl methacrylate and ethylene glycol dimethacrylate.

[0012] As a further improvement of the present application, the photoinitiator is 2-methyl-1-[4-(methylthio)phenyl]-2-(4-morpholinyl)-1-propanone.

[0013] As a further improvement of the present application, the defoaming agent is one or two of polydimethylsiloxane and a copolymer of ethylene oxide and propylene oxide.

[0014] As a further improvement of the present application, the toluene mother liquor is prepared by the following method:

[0015] By weight, 47 parts of toluene solution are placed on a homogenizer, the toluene solution completely covers the stirring blade of the homogenizer, the stirring blade is rotated counterclockwise, and the stirring speed is ≥3600r / min. After the stirring begins, 3 parts of bentonite are added at a position adjacent to the stirring blade. After the addition is completed, the stirring blade is rotated clockwise, and the stirring speed is ≥3600r / min. Then, the mixed solution is passed through a 10-inch 4.5μm filter element for a circulation filtration time of not less than 60min to obtain a toluene mother liquor.

[0016] To achieve the above object, the present application also provides a method for preparing an AG coating liquid, comprising the following steps:

[0017] By weight, 20 to 40 parts of main resin, 5 to 15 parts of compounding resin, 15 to 25 parts of toluene, 10 to 15 parts of butanone, and 5 to 15 parts of toluene mother liquor in step S1 are first added into a reaction container, and the reaction container is rotated clockwise at a speed of ≥1350rpm / min for 30min. Then, 1 to 2 parts of acrylic particles, 5 parts of leveling agent, and 1 to 2 parts of photoinitiator are added into the reaction container, and the reaction container is rotated clockwise at a speed of ≥2500rpm / min for 20min. Then, 5 to 15 parts of defoaming agent filtered through a 20-inch 10μm filter are added into the reaction container, the reaction container is evacuated to -0.1MPa, and the reaction container is rotated clockwise at a speed of 100rpm / min for 10min to 1h, and the final mixed solution is circulated and filtered through a 5 to 15-inch 1 to 10μm filter to obtain an AG coating liquid.

[0018] To achieve the above objectives, the present application also provides a use of the above-mentioned coating liquid in preparing a polarizer.

[0019] To achieve the above-mentioned purpose, the present application also provides a polarizer, which includes, from bottom to top, a lower protective film layer, a polarizing film layer, and an upper protective film layer, wherein the polarizing film layer includes a relative upper surface and a lower surface, the upper protective film layer is bonded to the upper surface of the polarizing film layer, and the lower protective film layer is bonded to the lower surface of the polarizing film layer, and an AG coating liquid is coated on the surface of the upper protective film layer away from the polarizing film layer and the surface of the lower protective film layer away from the polarizing film layer, and the AG coating liquid is the coating liquid described above.

[0020] As a further improvement of the present application, the upper protective film is any one of a PMMA film, a TAC film, and a PET film, and the lower protective film is any one of a PMMA film, a TAC film, and a PET film.

[0021] The beneficial effect of the present application is that the present application provides an AG coating liquid, in which acrylic particles are added to improve the anti-glare performance of the coating liquid, and a defoaming agent is added to suppress bubbles generated during the preparation of the coating liquid. The present application also provides a method for preparing an AG coating liquid, in which the toluene mother liquor, the defoaming agent, and the final mixed solution are all filtered through a filter to further remove bubbles in the AG coating liquid, thereby avoiding the inability to quickly and effectively discharge bubbles during on-line coating, which affects the coating effect.

[0022] The AG coating liquid has excellent stability and dispersibility, is not prone to agglomeration and is easy to coat. It will not affect the optical properties of the AG layer after PMMA coating, nor will it affect the bonding performance of the Primer surface of the PMMA film when it is bonded to a polarizer. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a physical picture of the AG coating solution prepared in Comparative Example 1 in a container;

[0024] Figure 2 This is a physical picture of the AG coating liquid prepared in Comparative Example 1 entering the glue supply system pipeline;

[0025] Figure 3 This is a schematic diagram of the film surface forming condition after coating the AG coating liquid prepared in Comparative Example 1;

[0026] Figure 4 Schematic diagram of broadband bubble point defects in the polarizer prepared by the AG coating solution of Comparative Example 1;

[0027] Figure 5 is a SEM image of the bubble point defect in the polarizer prepared by the AG coating solution of Comparative Example 2 after cutting;

[0028] Figure 6 It is a schematic diagram of the structure of the polarizer of TAC+TAC architecture;

[0029] Figure 7 This is a schematic diagram of the structure of the PMMA+PET polarizer;

[0030] Figure 8 This is a schematic diagram of the structure of a polarizer with a PMMA+PMMA architecture. DETAILED DESCRIPTION

[0031] The present invention is further described below. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and are not intended to limit the protection scope of the present invention.

[0032] The AG coating liquid used in the preparation process of polarizer will generate a large number of bubbles during the preparation, stirring and canning process, so that the stored AG coating liquid to be used will contain many bubbles. The causes include: the viscosity increases too quickly and the stirring speed is too fast during the preparation process. In order to solve the problem of excessive bubbles in the coating liquid, the present application provides an AG coating liquid, a preparation method and a polarizer using the same.

[0033] To achieve the above object, the present invention adopts the following technical solutions:

[0034] The present application provides an AG coating solution, which comprises the following components by weight:

[0035]

[0036] In an optional embodiment, the main resin is acrylic resin, and the auxiliary resin is 2-(4-hydroxybutyl) acrylate.

[0037] In an alternative embodiment, the acrylic particles are copolymers of methyl methacrylate and ethylene glycol dimethacrylate.

[0038] In an alternative embodiment, the photoinitiator is 2-methyl-1-[4-(methylthio)phenyl]-2-(4-morpholinyl)-1-propanone.

[0039] In an optional embodiment, the defoaming agent is one or two of polydimethylsiloxane and a copolymer of ethylene oxide and propylene oxide.

[0040] In an optional embodiment, the toluene mother liquor is prepared by the following method:

[0041] By weight, 47 parts of toluene solution are placed on a homogenizer, the toluene solution completely covers the stirring blade of the homogenizer, the stirring blade is rotated counterclockwise, and the stirring speed is ≥3600r / min. After the stirring begins, 3 parts of bentonite are added at a position adjacent to the stirring blade. After the addition is completed, the stirring blade is rotated clockwise, and the stirring speed is ≥3600r / min. Then, the mixed solution is passed through a 10-inch 4.5μm filter element for a circulation filtration time of not less than 60min to obtain a toluene mother liquor.

[0042] The present application also provides a method for preparing an AG coating solution, comprising the following steps:

[0043] By weight, 20 to 40 parts of main resin, 5 to 15 parts of compounding resin, 15 to 25 parts of toluene, 10 to 15 parts of butanone, and 5 to 15 parts of toluene mother liquor in step S1 are first added into a reaction container, and the reaction container is rotated clockwise at a speed of ≥1350rpm / min for 30min. Then, 1 to 2 parts of acrylic particles, 5 parts of leveling agent, and 1 to 2 parts of photoinitiator are added into the reaction container, and the reaction container is rotated clockwise at a speed of ≥2500rpm / min for 20min. Then, 5 to 15 parts of defoaming agent filtered through a 20-inch 10μm filter are added into the reaction container, the reaction container is evacuated to -0.1MPa, and the reaction container is rotated clockwise at a speed of 100rpm / min for 10min to 1h, and the final mixed solution is circulated and filtered through a 5 to 15-inch 1 to 10μm filter to obtain an AG coating liquid.

[0044] The present application also provides a polarizer, which includes, from bottom to top, a lower protective film layer, a polarizing film layer, and an upper protective film layer, wherein the polarizing film layer includes a relative upper surface and a lower surface, the upper protective film layer is bonded to the upper surface of the polarizing film layer, and the lower protective film layer is bonded to the lower surface of the polarizing film layer, and an AG coating liquid is coated on the surface of the upper protective film layer away from the polarizing film layer and the surface of the lower protective film layer away from the polarizing film layer, and the AG coating liquid is the coating liquid described above.

[0045] In an optional embodiment, when the AG coating liquid is applied to the PMMA film, a slit die coater is used. The slit die coater is designed with a mold that can evenly distribute the AG coating liquid in the lateral direction. The coating film surface is smoothed by creating a fault between the top of the mold, called the "die lip", and the support roller. This method supplies the AG coating liquid enclosed in the container to the "mold" through pressure, so the AG coating liquid will not be affected by the air and stable coating can be achieved. The coating head gasket generally uses a 50-100um PET gasket, which is sandwiched between the upper lip and the lower lip. The film surface is then adjusted by adjusting the gap between the coating head and the back roller, the vacuum degree of the coating head itself, and the frequency of the liquid supply pump.

[0046] In an optional embodiment, the upper protective film is any one of a PMMA film, a TAC film, and a PET film, and the lower protective film is any one of a PMMA film, a TAC film, and a PET film.

[0047] In order to verify that the AG coating liquid prepared by the technical solution of the present application has excellent coating performance, the following experimental data are also provided for verification.

[0048] Example 1

[0049] Preparation of toluene mother liquor: 47 parts of toluene are placed on a homogenizer by weight, the toluene solution completely covers the stirring blade of the homogenizer, the stirring blade is rotated counterclockwise, and the stirring speed is ≥3600r / min. After the stirring begins, 3 parts of bentonite are added at a position adjacent to the stirring blade. After the addition is completed, the stirring blade is rotated clockwise, and the stirring speed is ≥3600r / min. The mixed solution is then filtered through a 10-inch 4.5μm filter element for 60 minutes to obtain a toluene mother liquor.

[0050] Preparation of AG coating liquid: by weight, first add 20 parts of main resin, 5 parts of compounding resin, 15 parts of toluene, 10 parts of butanone, and 5 parts of toluene mother liquor in step S1 into a reaction container, rotate clockwise at a speed of ≥1350rpm / min for 30min, then add 1 part of acrylic particles, 5 parts of leveling agent, and 1 part of photoinitiator into the above reaction container, rotate clockwise at a speed of ≥2500rpm / min for 20min, and then add 5 parts of polydimethylsiloxane filtered through a 20-inch 10μm filter into the above reaction container, evacuate the reaction container to -0.1MPa, rotate clockwise at a speed of 100rpm / min for 10min, and circulate and filter the final mixed solution through a 5-inch 1μm filter to obtain an AG coating liquid.

[0051] Example 2

[0052] Preparation of toluene mother liquor: 47 parts of toluene solution are placed on a homogenizer by weight, the toluene solution completely covers the stirring blade of the homogenizer, the stirring blade is rotated counterclockwise, and the stirring speed is ≥3600r / min. After the stirring begins, 3 parts of bentonite are added at a position adjacent to the stirring blade. After the addition is completed, the stirring blade is rotated clockwise, and the stirring speed is ≥3600r / min. Then the mixed solution is filtered through a 10-inch 4.5μm filter element for 60 minutes to obtain a toluene mother liquor.

[0053] Preparation of AG coating liquid: by weight, first add 30 parts of main resin, 10 parts of compounding resin, 20 parts of toluene, 13 parts of butanone, and 10 parts of toluene mother liquor in step S1 into a reaction container, rotate clockwise at a speed of ≥1350rpm / min for 30min, then add 2 parts of acrylic particles, 5 parts of leveling agent, and 2 parts of photoinitiator into the above reaction container, rotate clockwise at a speed of ≥2500rpm / min for 20min, and then add 10 parts of polydimethylsiloxane filtered through a 20-inch 10μm filter into the above reaction container, evacuate the reaction container to -0.1Mpa, rotate clockwise at a speed of 100rpm / min for 10min, and circulate and filter the final mixed solution through a 10-inch 5μm filter to obtain an AG coating liquid.

[0054] Example 3

[0055] Preparation of toluene mother liquor: 47 parts of toluene solution are placed on a homogenizer by weight, the toluene solution completely covers the stirring blade of the homogenizer, the stirring blade is rotated counterclockwise, and the stirring speed is ≥3600r / min. After the stirring begins, 3 parts of bentonite are added at a position adjacent to the stirring blade. After the addition is completed, the stirring blade is rotated clockwise, and the stirring speed is ≥3600r / min. Then the mixed solution is filtered through a 10-inch 4.5μm filter element for 60 minutes to obtain a toluene mother liquor.

[0056] Preparation of AG coating liquid: by weight, first add 40 parts of main resin, 15 parts of compounding resin, 25 parts of toluene, 15 parts of butanone, and 15 parts of toluene mother liquor in step S1 into a reaction container, rotate clockwise at a speed of ≥1350rpm / min for 30min, then add 2 parts of acrylic particles, 5 parts of leveling agent, and 2 parts of photoinitiator into the above reaction container, rotate clockwise at a speed of ≥2500rpm / min for 20min, and then add 15 parts of polydimethylsiloxane filtered through a 20-inch 10μm filter into the above reaction container, evacuate the reaction container to -0.1MPa, rotate clockwise at a speed of 100rpm / min for 10min, and circulate and filter the final mixed solution through a 15-inch 10μm filter to obtain an AG coating liquid.

[0057] Example 4

[0058] The difference between this embodiment and embodiment 2 is that a copolymer of ethylene oxide and propylene oxide is used instead of polydimethylsiloxane.

[0059] Example 5

[0060] The difference between this embodiment and embodiment 2 is that polydimethylsiloxane and a copolymer of ethylene oxide and propylene oxide are used instead of polydimethylsiloxane, wherein the mass ratio of the copolymer of ethylene oxide and propylene oxide to polydimethylsiloxane is 1:1.

[0061] Comparative Example 1

[0062] The difference between this comparative example and Example 2 is that no defoaming agent, that is, no polydimethylsiloxane, is added in this comparative example. Figure 1 A physical picture of the AG coating liquid prepared in this comparative example in a container is given, and the physical picture shows that bubbles appear in the finally prepared AG coating liquid without adding a defoaming agent. Figure 2 The actual picture of the AG coating liquid prepared in this comparative example entering the glue supply system pipeline is given. After observation, the AG coating liquid in the pipeline has obvious bubbles, which need to be manually discharged again, otherwise the coating effect will be affected. After the AG coating liquid prepared in comparative example 1 is applied, the film surface will not be formed. The coating situation is referenced Figure 3 .

[0063] Comparative Example 2

[0064] The difference between this comparative example and Example 2 is that the AG coating liquid of this comparative example was not subjected to negative pressure defoaming in a stirring tank during the preparation process, that is, the reaction container was not evacuated to -0.1 MPa.

[0065] During the experiment, polarizers were prepared from the AG coating solutions of Examples 1 to 5 and Comparative Examples 1 and 2, and then tested by AOI (Automated Optical Inspection). The polarizers prepared from the AG coating solutions of Examples 1 to 5 did not contain bubbles or point defects; the polarizers prepared from the AG coating solution of Comparative Example 1 contained a large number of broadband bubble point defects, such as Figure 4 As shown; the polarizer prepared by the coating solution of Comparative Example 2 contains a small amount of bubbles, which are shown as bubble point defects as a whole. The scanning electron microscope (SEM) of the bubble point defect after cutting is as follows Figure 5 shown.

[0066] In summary, a defoamer is added to the AG coating liquid in the present application, and the defoamer can effectively inhibit and remove the trace bubbles already existing in the solution, so as to avoid the bubbles in the AG coating liquid affecting the coating of the PMMA film, TAC film or PET film. The generation of some bubbles can be reduced by a circulating filter during the glue supply process after production. The defoamer of the present application has excellent stability and dispersibility, is not prone to coagulation and is easy to apply. It will not affect the optical properties of the PMMA film, TAC film or PET film, nor will it affect the anti-glare performance and cleanliness of the PMMA film, TAC film or PET film after coating.

[0067] The AG coating liquid prepared by the technical solution provided in the present application contains substantially no bubbles and has excellent stability and dispersibility. After being applied to the surface of a PMMA, TAC or PET protective film, the polarizer prepared therefrom has excellent optical properties, wherein: the architecture of the polarizer can be a TAC+TAC architecture, a PMMA+PET architecture, a PMMA+PMMA architecture, etc. The structural schematic diagram of a specific polarizer corresponding to the TAC+TAC architecture is as follows Figure 6 As shown, the structural diagram of the specific polarizer corresponding to the PMMA+PET architecture is as follows Figure 7 As shown, the structural diagram of the specific polarizer corresponding to the PMMA+PMMA architecture is as follows Figure 8 shown.

[0068] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. An AG coating liquid, characterized in that: The components include the following by weight:

2. The AG coating solution according to claim 1, characterized in that: The main resin is acrylic resin, and the auxiliary resin is 2-(4-hydroxybutyl) acrylate.

3. The AG coating solution according to claim 1, characterized in that: The acrylic particles are copolymers of methyl methacrylate and ethylene glycol dimethacrylate.

4. The AG coating solution according to claim 1, characterized in that: The photoinitiator is 2-methyl-1-[4-(methylthio)phenyl]-2-(4-morpholinyl)-1-propanone.

5. The AG coating solution according to claim 1, characterized in that: The defoaming agent is one or two of polydimethylsiloxane and a copolymer of ethylene oxide and propylene oxide.

6. The AG coating solution according to claim 1, characterized in that: The toluene mother liquor is prepared by the following method: By weight, 47 parts of toluene solution are placed on a homogenizer, the toluene solution covers the stirring blade of the homogenizer, the stirring blade is rotated counterclockwise, and the stirring speed is ≥3600r / min. After the stirring begins, 3 parts of bentonite are added at a position adjacent to the stirring blade. After the addition is completed, the stirring blade is rotated clockwise, and the stirring speed is ≥3600r / min. Then, the mixed solution is passed through a 10-inch 4.5μm filter element for a circulation filtration time of not less than 60min to obtain a toluene mother liquor.

7. A method for preparing the AG coating solution according to any one of claims 1 to 6, characterized in that: The steps include: By weight, 20 to 40 parts of main resin, 5 to 15 parts of compounding resin, 15 to 25 parts of toluene, 10 to 15 parts of butanone, and 5 to 15 parts of toluene mother liquor in step S1 are first added into a reaction container, and the reaction container is rotated clockwise at a speed of ≥1350rpm / min for 30min. Then, 1 to 2 parts of acrylic particles, 5 parts of leveling agent, and 1 to 2 parts of photoinitiator are added into the reaction container, and the reaction container is rotated clockwise at a speed of ≥2500rpm / min for 20min. Then, 5 to 15 parts of defoaming agent filtered through a 20-inch 10μm filter are added into the reaction container, the reaction container is evacuated to -0.1Mpa, and the reaction container is rotated clockwise at a speed of 100rpm / min for 10min to 1h, and the final mixed solution is circulated and filtered through a 5 to 15-inch 1 to 10μm filter to obtain an AG coating liquid.

8. Use of the coating solution according to any one of claims 1 to 6 in preparing a polarizer.

9. A polarizer, comprising, from bottom to top, a lower protective film layer, a polarizing film layer, and an upper protective film layer, wherein the polarizing film layer comprises an upper surface and a lower surface opposite to each other, the upper protective film layer is bonded to the upper surface of the polarizing film layer, and the lower protective film layer is bonded to the lower surface of the polarizing film layer, characterized in that: Coating AG coating liquid on the surface of the upper protective film layer away from the polarizing film layer and the surface of the lower protective film layer away from the polarizing film layer, The AG coating liquid is the coating liquid according to any one of claims 1 to 6.

10. The polarizer according to claim 9, characterized in that: The upper protective film is any one of a PMMA film, a TAC film, and a PET film, and the lower protective film is any one of a PMMA film, a TAC film, and a PET film.

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