Polarizer and preparation method thereof

Abstract

The invention provides a polaroid and a preparation method thereof. The polaroid sequentially comprises a protective film, a COATIN-optical compensation film layer, a polarized photon layer, a compensation layer and a release film from one side to the other side, and the optical axis angle of the COATIN-optical compensation film layer is inclined by 20-50 degrees, and the compensation value is 40-10000. By the adoption of the technical scheme, the circular polarization conversion layer is externally arranged in the polaroid structure while the linear polaroid layer is reserved, compatibility of the polaroid and an LCD panel is reserved, and linear polarization can be converted into circular polarization; according to the present invention, the xanthophyll-containing eye protection film can effectively protect eyes, can efficiently filter blue light, has characteristics of low glare interference and stable dynamic display, and can reduce the dependence of retina on xanthophyll so as to effectively protect eyes during long-term use.

Description

Technical Field

[0001] This invention relates to the field of polarizer technology, and more particularly to a polarizer and its preparation method. Background Technology

[0002] Currently, the polarizers used in conventional LCDs (Liquid Crystal Displays) primarily rely on linear polarization technology. LCDs control brightness by modulating the polarization direction of light through voltage-controlled liquid crystal molecule alignment. Linear polarizers (typically vertically and horizontally polarized) are located on opposite sides of the liquid crystal layer, respectively. By altering the liquid crystal alignment through electrical signals, they selectively block or transmit polarized light, thus achieving image display. However, current linear polarization technology has the following drawbacks:

[0003] ①Reflected light (such as sunlight or lamplight reflected on the screen surface) is usually linearly polarized. If it is in the same polarization direction as the linear polarizer of the display, it will pass through directly, resulting in strong glare, such as making it difficult to see the mobile phone screen in sunlight.

[0004] ②When the LCD is in the dark, the liquid crystal molecules are not completely uniformly arranged, which may cause some linearly polarized light to leak, thus reducing the panel contrast. This is more obvious on VA Mode panels.

[0005] ③ Regarding eye protection, blue light and glare are harmful light sources that irritate the eyes. Linear polarizers cannot filter unpolarized blue light themselves, requiring other adjustments to achieve a blue light blocking effect. Simultaneously, linear polarizers cannot eliminate unpolarized glare (such as diffuse light), forcing users to increase screen brightness to compensate for visibility, thus increasing blue light exposure. Furthermore, because the vibration direction of linear polarizers is fixed, the stimulation to the human eye is concentrated in one direction, having little impact on the absorption characteristics of lutein. It only allows specific lutein molecules to function, and prolonged viewing may lead to more pronounced eye fatigue.

[0006] Existing circular polarizers are expensive and mainly used in small and medium-sized panels, and are incompatible with the modulation mechanism of LCD liquid crystals. Summary of the Invention

[0007] To address the above technical problems, this invention discloses a polarizer and its preparation method, which not only retains the compatibility between the polarizer and the LCD panel, but also converts linear polarized light into circular polarized light, thus providing an eye-protecting effect.

[0008] The technical solution adopted by this invention is as follows:

[0009] A polarizer comprises, from one side to the other, a protective film, a coupling-optical compensation film layer, a polarizer layer, a compensation layer, and a release film; the optical axis angle of the coupling-optical compensation film layer is obliquely 20-50°, and the compensation value is 40-10000. The compensation layer serves as an inner protective layer.

[0010] Using this technical solution, the COATING-optical compensation film layer has optical compensation function. When combined with the polarizer layer, it becomes a circular polarizer. This not only maintains the compatibility between the polarizer and the LCD panel, but also converts linear polarized light into circular polarized light. It also has higher blue light filtering efficiency, lower glare interference, and can reduce the retina's dependence on lutein, thus protecting the eyes more effectively.

[0011] As a further improvement of the present invention, the compensation layer is connected to the release film through a pressure-sensitive adhesive layer.

[0012] As a further improvement of the present invention, the COATING-optical compensation film layer is made of cellulose triacetate, cyclic olefin copolymer, polyethylene terephthalate or acrylic resin; the polarizer layer is made of polyvinyl alcohol.

[0013] As a further improvement of the present invention, the pressure-sensitive adhesive layer is a polyacrylate pressure-sensitive adhesive with a thickness of 5-30 μm.

[0014] As a further improvement of the present invention, the protective film is made of polyethylene terephthalate or polycarbonate; the compensation layer is made of cellulose triacetate, cyclic olefin copolymer or acrylic resin; and the release film is a polyethylene terephthalate film or polycarbonate film treated with silane.

[0015] As a further improvement of the present invention, an inner protective layer is provided between the COATING-optical compensation film layer and the polarizer layer.

[0016] As a further improvement of the present invention, the COATING-optical compensation film layer is connected to the inner protective layer through a pressure-sensitive adhesive layer; the material of the inner protective layer is cellulose triacetate, cyclic olefin copolymer or acrylic resin.

[0017] This invention discloses a method for preparing the polarizer as described above, comprising the following steps:

[0018] Step S11: After the polarizer layer material is stretched by a wet process, its upper and lower surfaces are bonded to the compensation layer and the COATING-optical compensation film layer using PVA composite adhesive. At the same time, a protective film is bonded to the surface of the COATING-optical compensation film layer to obtain a semi-finished product.

[0019] Step S12: The bonded semi-finished product is bonded to a release film coated with pressure-sensitive adhesive.

[0020] This invention discloses a method for preparing the polarizer as described above, comprising the following steps:

[0021] Step S21: After the polarizer layer material is subjected to a wet stretching process, its upper and lower surfaces are bonded to the compensation layer and the inner protective layer using PVA composite adhesive to obtain a semi-finished product.

[0022] Step S22: The semi-finished product is bonded to a release film coated with pressure-sensitive adhesive;

[0023] Step S23: Apply a COATING-optical compensation film layer to the surface of the inner protective layer using pressure-sensitive adhesive;

[0024] Step S24: Apply a protective film to the surface of the COATING-optical compensation film layer.

[0025] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0026] First, by employing the technical solution of this invention, while retaining the linear polarizer layer, a circular polarizer conversion layer is externally placed within the polarizer structure. This structure maintains the compatibility between the polarizer and the LCD panel, and also converts linear polarized light into circular polarized light. Compared to linear polarizers, the circular polarizer produced by this invention, after being bonded to the LCD panel, exhibits a more uniform absorption of lutein due to the change in its electric field vector direction over time. The blue light filtering efficiency of the circular polarizer can be 10-15% higher than that of ordinary linear polarizers. Therefore, through more efficient blue light filtering, lower glare interference, and more stable dynamic display, it can reduce the retina's dependence on lutein, thus providing more effective eye protection during long-term use.

[0027] Secondly, the circular polarization structure of this invention can eliminate polarized glare, and with the addition of a coating and HDR, it can achieve a sunglasses-free function. Compared to existing circular polarizers, this invention has wider applications in the LCD field and can be used in panels with VA Mode, IPS Mode, and other display modes.

[0028] Third, the technical solution of the present invention can ensure circular polarization performance while achieving roll-to-roll lamination of film material during the polarizer manufacturing process, thus allowing it to be used in larger sizes and reducing costs. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the structure of a polarizer according to Embodiment 1 of the present invention.

[0030] Figure 2 This is a schematic diagram of the structure of a polarizer according to Embodiment 2 of the present invention.

[0031] The reference numerals in the figures include:

[0032] 1-Protective film, 2-COATING-Optical compensation film layer, 3-Polarizing layer, 4-Compensation layer, 5-Release film, 6-First pressure-sensitive adhesive layer, 7-Inner protective layer, 8-Second pressure-sensitive adhesive layer. Detailed Implementation

[0033] The preferred embodiments of the present invention will be described in further detail below.

[0034] Example 1

[0035] like Figure 1 As shown, a polarizer comprises, from one side to the other, a protective film 1, a COATING-optical compensation film layer 2, a polarizer layer 3, a compensation layer 4, and a release film 5. The optical axis angle of the COATING-optical compensation film layer 2 is obliquely 20-50°, and the compensation value is 40-10000. The compensation layer 4 is connected to the release film 5 through a first pressure-sensitive adhesive layer 6.

[0036] The COATING-optical compensation film layer 2 is made of cellulose triacetate, cyclic olefin copolymer, polyethylene terephthalate, or acrylic resin; the polarizer layer 3 is made of polyvinyl alcohol. The first pressure-sensitive adhesive layer is polyacrylic acid adhesive with a thickness of 5–30 μm.

[0037] The protective film 1 is made of polyethylene terephthalate or polycarbonate; the compensation layer 4 is made of cellulose triacetate, cyclic olefin copolymer or acrylic resin; and the release film 5 is a polyethylene terephthalate film or polycarbonate film treated with silane.

[0038] The polarizer in this embodiment is prepared using the following steps:

[0039] Step S11: After the polarizer layer material is stretched by a wet process, its upper and lower surfaces are bonded to the compensation layer and the COATING-optical compensation film layer using PVA composite adhesive. At the same time, a protective film is bonded to the surface of the COATING-optical compensation film layer to obtain a semi-finished product.

[0040] Step S12: The bonded semi-finished product is bonded to a release film coated with pressure-sensitive adhesive.

[0041] Example 2

[0042] Based on Example 1, such as Figure 2 As shown, in the polarizer of this embodiment, an inner protective layer 7 is provided between the COATING-optical compensation film layer 2 and the polarizer layer 3. The COATING-optical compensation film layer 2 is connected to the inner protective layer 7 through a second pressure-sensitive adhesive layer 8; the inner protective layer 7 is made of cellulose triacetate, cyclic olefin copolymer, or acrylic resin. The second pressure-sensitive adhesive layer 8 is polyacrylic acid adhesive with a thickness of 5–30 μm.

[0043] The polarizer in this embodiment is prepared using the following steps:

[0044] Step S21: After the polarizer layer material is subjected to a wet stretching process, its upper and lower surfaces are bonded to the compensation layer and the inner protective layer using PVA composite adhesive to obtain a semi-finished product.

[0045] Step S22: The semi-finished product is bonded to a release film coated with pressure-sensitive adhesive;

[0046] Step S23: Apply a COATING-optical compensation film layer to the surface of the inner protective layer using pressure-sensitive adhesive;

[0047] Step S24: Apply a protective film to the surface of the COATING-optical compensation film layer.

[0048] The above description, in conjunction with specific preferred embodiments, provides a further detailed explanation of the present invention. It should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various simple deductions or substitutions can be made without departing from the concept of the present invention, and all such modifications and substitutions should be considered within the scope of protection of the present invention.

Claims

1. A polarizer, characterized in that: It comprises, from one side to the other, a protective film, a COATING-optical compensation film layer, a polarizer layer, a compensation layer, and a release film; the optical axis angle of the COATING-optical compensation film layer is obliquely 20 to 50°, and the compensation value is 40 to 10000.

2. The polarizer according to claim 1, characterized in that: The compensation layer is connected to the release film via a pressure-sensitive adhesive layer.

3. The polarizer according to claim 1, characterized in that: The COATING optical compensation film is made of cellulose triacetate, cyclic olefin copolymer, polyethylene terephthalate, or acrylic resin; the polarizer layer is made of polyvinyl alcohol.

4. The polarizer according to claim 1, characterized in that: The pressure-sensitive adhesive layer is a polyacrylate pressure-sensitive adhesive with a thickness of 5–30 μm.

5. The polarizer according to claim 1, characterized in that: The protective film is made of polyethylene terephthalate or polycarbonate; the compensation layer is made of cellulose triacetate, cyclic olefin copolymer or acrylic resin; the release film is a polyethylene terephthalate film or polycarbonate film treated with silane.

6. The polarizer according to any one of claims 1 to 5, characterized in that: An inner protective layer is provided between the COATING optical compensation film layer and the polarizer layer.

7. The polarizer according to claim 6, characterized in that: The COATING optical compensation film layer is connected to the inner protective layer through a pressure-sensitive adhesive layer; the inner protective layer is made of cellulose triacetate, cyclic olefin copolymer or acrylic resin.

8. The method for preparing a polarizer according to any one of claims 1 to 5, characterized in that: Includes the following steps: Step S11: After the polarizer layer material is stretched by a wet process, its upper and lower surfaces are bonded to the compensation layer and the COATING-optical compensation film layer using PVA composite adhesive. At the same time, a protective film is bonded to the surface of the COATING-optical compensation film layer to obtain a semi-finished product. Step S12: The bonded semi-finished product is bonded to a release film coated with pressure-sensitive adhesive.

9. The method for preparing a polarizer according to any one of claims 6 to 7, characterized in that: Includes the following steps: Step S21: After the polarizer layer material is subjected to a wet stretching process, its upper and lower surfaces are bonded to the compensation layer and the inner protective layer using PVA composite adhesive to obtain a semi-finished product. Step S22: The semi-finished product is bonded to a release film coated with pressure-sensitive adhesive; Step S23: Apply a COATING-optical compensation film layer to the surface of the inner protective layer using pressure-sensitive adhesive; Step S24: Apply a protective film to the surface of the COATING-optical compensation film layer.

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