A high water-barrier optical film and a polarizing plate comprising the same
By designing a water-blocking layer with nano-protrusions and microporous structures on the optical film, and combining it with modified acrylate polymers and polyvinylidene fluoride resin, the balance between water-blocking and optical properties of the optical film is solved, resulting in an optical film with high water resistance and low haze, suitable for applications such as displays and touch screens.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- HEFEI XINMEI MATERIALS TECHNOLOGY CO LTD
- Filing Date
- 2025-01-21
- Publication Date
- 2026-06-26
AI Technical Summary
Existing optical films struggle to balance water-blocking and optical properties, especially in high-temperature and high-humidity environments where water permeability is high, failing to effectively protect equipment or products. Furthermore, traditional water-blocking materials may affect transparency and gloss.
A water-blocking layer with nano-protrusions and microporous structure is combined with modified acrylate polymer and polyvinylidene fluoride resin to form a highly water-blocking optical film. It is manufactured using nanoimprinting technology to ensure that water molecules cannot penetrate it and UV absorbers are added to prevent aging.
It achieves high water resistance and low fogging in humid environments, preventing equipment from being damaged by moisture, while maintaining excellent optical performance and durability, making it suitable for applications such as displays and touch screens.
Smart Images
Figure CN119575520B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of optical thin film technology, and more particularly to a high water-resistant optical film and a polarizing plate containing the same. Background Technology
[0002] With the rapid development of modern technology, optical films play an indispensable and crucial role in many fields such as displays and touch screens. In these applications, optical films not only need to possess excellent optical properties, but also face extremely stringent requirements regarding their barrier properties, especially their water-blocking properties.
[0003] In the field of display technology, such as liquid crystal displays (LCDs) and organic light-emitting diode displays (OLEDs), moisture intrusion can cause serious damage to internal sensitive components and materials. For LCDs, moisture can lead to deterioration of the liquid crystal material, corrosion of the electrodes, and degradation of the polarizer's performance, resulting in problems such as uneven display, color deviation, reduced contrast, and even screen failure. In OLEDs, moisture can react chemically with the organic light-emitting materials, significantly shortening their lifespan and producing defects such as black spots and bright spots, severely impacting display quality and product reliability.
[0004] In touchscreen technology, whether capacitive or resistive, moisture penetration can alter the touchscreen's electrical properties and surface characteristics. For example, it may lead to decreased touch sensitivity, inaccurate positioning, or even touch functionality failure, significantly reducing user experience and product market competitiveness.
[0005] However, traditional optical films often fall short of the growing demand for water-blocking performance. Some conventional optical films exhibit high water permeability in high-temperature and high-humidity environments, failing to provide sufficient protection for the equipment or products they are used in. For example, some common polymer-based optical films, due to their molecular structure and microstructure, allow water molecules to pass through the film relatively easily, leading to a higher risk of moisture damage to the equipment during use.
[0006] At the same time, in pursuing high water-blocking performance, the optical properties of the optical film cannot be ignored. Many materials or treatments with good water-blocking properties may increase the haze of the optical film, reducing its transparency and gloss, which is unacceptable for applications with extremely high requirements for optical clarity. For example, although some inorganic water-blocking coatings have good water-blocking effects, their crystal structure or surface roughness can easily cause light scattering, leading to increased haze of the optical film and failing to meet the stringent requirements for low haze in fields such as high-definition displays.
[0007] CN113249062A discloses an adhesive composition, an adhesive, an adhesive sheet, and an optical film with an adhesive layer. The adhesive composition contains a (meth)acrylate polymer (A). In the molecular weight distribution of the (meth)acrylate polymer (A) determined by gel permeation chromatography, the amount of the component with a molecular weight of 3 million or more is 15% by mass or less, and the peak molecular weight (Mp) is 800,000 or more and 1.2 million or less. Furthermore, when the (meth)acrylate polymer (A) is dissolved at a concentration of 20% by mass in a mixed solvent of ethyl acetate and acetone containing 85% by mass of ethyl acetate, the viscosity is 5000 mPa·s or more and 10000 mPa·s or less. This adhesive, adhesive sheet, and optical film with an adhesive layer exhibit excellent durability and good processability when coating the adhesive composition.
[0008] CN107033647A discloses a polarizing plate comprising an aqueous primer composition, and a method for preparing an optical film comprising a primer layer. For every 100 parts by weight of the primer composition, the primer composition comprises 1 to 30 parts by weight of a polyurethane polymer, 0.1 to 10 parts by weight of water-dispersible particles, and the balance being water. The polarizing plate is located between the optical film and the primer layer formed from the primer composition. The method includes coating at least one side of the optical film with the primer composition; and drying the optical film coated with the primer composition. The primer composition has good adhesion properties and can be included in the polarizing plate without reducing its transparency and without requiring additional processes or equipment.
[0009] CN104356967A discloses a UV-curable polyolefin optical film and its preparation method. The UV-curable polyolefin optical film is made by premixing 100 parts by weight of ethylene-octene copolymer, 0.1-2 parts by weight of hydroxyl-containing acrylate monomer, 0.3-2 parts by weight of photoinitiator, 0-1.0 parts by weight of co-crosslinking agent, 0.05-0.5 parts by weight of light stabilizer, 0.05-0.5 parts by weight of antioxidant, and 0-1.0 parts by weight of coupling agent in a conical stirrer before casting. The preparation method is simple, easy to operate, and has high production efficiency. The obtained UV-curable polyolefin optical film not only has the advantages of easy processing and reworkability, but also has excellent water vapor barrier properties, insulation properties, adhesion properties, and non-corrosive properties.
[0010] However, the water-blocking performance of the aforementioned optical films still needs further improvement. Summary of the Invention
[0011] In view of the problems existing in the prior art, the present invention provides a high water-blocking optical film and a polarizing plate containing the same. The high water-blocking optical film has a water-blocking layer with a special material combination and structural design, which can effectively block the penetration of water molecules and provide sufficient protection for the equipment or products in which it is applied.
[0012] To achieve this objective, the present invention adopts the following technical solution:
[0013] In a first aspect, the present invention provides a high water-blocking optical film, the high water-blocking optical film comprising a base film, a water-blocking layer and an adhesive layer;
[0014] The structure of the high water-blocking optical film includes a water-blocking layer, a first adhesive layer, a base film and a second adhesive layer stacked in sequence, or a water-blocking layer, a base film and a second adhesive layer stacked in sequence.
[0015] The surface of the water-blocking layer has a uniform and orderly arranged nanoprotrusion and microporous structure.
[0016] The high water-resistant optical film has a haze of less than 1% and a water permeability of <130g / m at 60℃ and 90%RH. 2 / day; the surface contact angle of the water-blocking layer is above 80°.
[0017] The high water-resistant optical film of this invention comprises a base film, a water-resistant layer, and an adhesive layer, wherein the adhesive layer can be disposed on one or both sides of the base film. The optical film of this invention has a water-resistant layer, exhibiting excellent hydrophobicity. The nano-protrusions and microporous structure significantly enhance the hydrophobicity. This microstructure causes water droplets to be approximately spherical on the surface of the optical film, minimizing the contact area with the film and thus greatly reducing the possibility of water wetting and penetration on the film surface. This ensures the stability and reliability of the optical film in humid environments and effectively prevents internal components or materials from deteriorating or being damaged due to moisture. Furthermore, the nano-protrusions and microporous structure are uniformly and orderly arranged, ensuring that the haze of the high water-resistant optical film is below 1%, without affecting normal optical performance while maintaining high water-resistant properties.
[0018] The nano-protrusions and microporous structures on the surface of the water-blocking layer of the present invention are manufactured using nanoimprint technology, which is suitable for large-scale industrial production.
[0019] The adhesive layer in the high water-resistant optical film of the present invention can be provided in one or two layers as needed. The structure of the high water-resistant optical film can be a water-resistant layer, a first adhesive layer, a base film, and a second adhesive layer stacked sequentially, or it can be a water-resistant layer, a base film, and a second adhesive layer stacked sequentially. The thickness of the first adhesive layer and the second adhesive layer can be the same or different, and can be adjusted according to actual needs.
[0020] The haze of the high water-resistant optical film of the present invention is less than 1%, for example, it can be 1%, 0.9%, 0.8%, 0.7%, 0.5%, 0.3% or 0.1%, etc., but it is not limited to the listed values. Other unlisted values within this range are also applicable.
[0021] Water permeability at 60℃ and 90%RH <130g / m 2 / day, for example, could be 129g / m 2 / day, 125g / m 2 / day, 120g / m 2 / day, 110g / m 2 / day, 100g / m 2 / day, 90g / m 2 / day or 50g / m 2 / day, etc., but not limited to the listed values; other unlisted values within this range also apply.
[0022] The surface contact angle of the water-blocking layer is 80° or higher, for example, it can be 80°, 81°, 83°, 85° or 89°, but it is not limited to the listed values. Other unlisted values within this range are also applicable.
[0023] Preferably, the thickness of the base film is 20 to 80 μm, for example, it can be 20 μm, 30 μm, 40 μm, 50 μm, 60 μm, 70 μm or 80 μm, but it is not limited to the listed values. Other unlisted values within this range are also applicable.
[0024] Preferably, the thickness of the water-blocking layer is 0.1 to 10 μm, for example, it can be 0.1 μm, 0.2 μm, 0.5 μm, 1 μm, 3 μm, 5 μm or 10 μm, but it is not limited to the listed values. Other unlisted values within this range are also applicable.
[0025] Preferably, the thickness of the adhesive layer is 200 to 1000 nm, for example, it can be 200 nm, 300 nm, 400 nm, 500 nm, 700 nm, 900 nm or 1000 nm, but it is not limited to the listed values. Other unlisted values within this range are also applicable.
[0026] Preferably, the height of the nanoprotrusion is 50 to 300 nm, for example, it can be 50 nm, 60 nm, 80 nm, 100 nm, 150 nm, 200 nm or 300 nm, but it is not limited to the listed values. Other unlisted values within this range are also applicable.
[0027] Preferably, the pore size of the microporous structure is 30 to 300 nm, for example, it can be 30 nm, 50 nm, 100 nm, 150 nm, 200 nm, 250 nm or 300 nm, but it is not limited to the listed values. Other unlisted values within this range are also applicable.
[0028] Preferably, the water-blocking layer is formed by coating and curing a water-blocking mixture.
[0029] Preferably, the mass fraction of the solvent in the water-blocking mixture is 40% to 70%, for example, it can be 40%, 45%, 50%, 55%, 60%, 65%, or 70%, but it is not limited to the listed values. Other unlisted values within this range are also applicable.
[0030] Preferably, the solvent comprises any one or a combination of at least two of toluene, acetone, methyl ethyl ketone (MEK), or dimethyl carbonate, wherein typical but non-limiting combinations include a combination of toluene and acetone, a combination of MEK and dimethyl carbonate, a combination of toluene and MEK, or a combination of dimethyl carbonate and acetone.
[0031] Preferably, the solids in the water-blocking mixture, by mass fraction, include 30% to 60% of the total solids by mass of modified acrylate polymer, for example, 30%, 35%, 40%, 45%, 50%, 55% or 60%, etc., but are not limited to the listed values, and other unlisted values within this range are also applicable.
[0032] 15% to 30% polyvinylidene fluoride resin, for example, 15%, 16%, 18%, 20%, 22%, 25% or 30%, etc., but not limited to the listed values, other unlisted values within this range also apply;
[0033] 2% to 6% of ultraviolet absorber, for example, 2%, 2.5%, 3%, 3.5%, 4%, 5% or 6%, etc., but not limited to the listed values, other unlisted values within this range are also applicable;
[0034] 1% to 3% of aziridine crosslinking agent, for example, 1%, 1.2%, 1.5%, 1.8%, 2%, 2.5% or 3%, etc., but not limited to the listed values, other unlisted values within this range are also applicable;
[0035] 0.5% to 1.5% of polyether-modified silicone defoamer, for example, 0.5%, 0.6%, 0.8%, 1%, 1.2%, 1.3% or 1.5%, etc., but not limited to the listed values, other unlisted values within this range are also applicable;
[0036] Citric acid of 0.1% to 0.5%, such as 0.1%, 0.2%, 0.25%, 0.3%, 0.35%, 0.4%, or 0.5%, but not limited to the listed values; other unlisted values within this range also apply.
[0037] 2% to 5% of phenolic hydroxyl compounds, for example, 2%, 2.5%, 3%, 3.5%, 4%, 4.5% or 5%, but not limited to the listed values, other unlisted values within this range also apply;
[0038] And 3% to 8% compatibilizer, for example, it can be 3%, 3.5%, 4%, 4.5%, 5%, 6% or 8%, etc., but is not limited to the listed values. Other unlisted values within this range are also applicable.
[0039] The polyvinylidene fluoride resin in the water-blocking mixture of this invention has low surface energy, making it difficult for water molecules to adhere to and diffuse on its surface. The modified acrylate polymer provides excellent film-forming properties and stability for the overall structure. Together, they form an effective hydrophobic barrier. Furthermore, the UV absorber efficiently absorbs ultraviolet radiation, effectively preventing aging, yellowing, and embrittlement of the optical film caused by UV irradiation. This significantly extends the service life of the optical film, ensuring that it maintains good optical, mechanical, and barrier properties even under long-term outdoor use or in environments with strong sunlight. It maintains stable light transmittance and low haze, guaranteeing the performance stability and appearance integrity of devices or products using the optical film. This provides a solid guarantee for its application in fields with high requirements for optical performance and durability, such as displays and touchscreens.
[0040] The present invention does not limit the ultraviolet absorber, and any one of benzotriazole, benzophenone or triazine can be selected, preferably benzotriazole, such as UV-P, which is more conducive to the transmittance of the optical film.
[0041] The phenolic hydroxyl compound described in this invention, when used in combination with a UV absorber, can further enhance the stability of the material. The phenolic hydroxyl compound may be pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate].
[0042] Preferably, the modified acrylate polymer comprises any one or a combination of at least two of the following: copolymers of long-chain alkyl vinyl ethers and acrylates, copolymers of protocatechuic acid and acrylates, copolymers of amine compounds and acrylates, copolymers of carbamates and acrylates, copolymers of aromatic vinyl compounds and acrylates, copolymers of organosilicones and acrylates, or copolymers of fluorinated monomers and acrylates. Typical but non-limiting combinations include combinations of copolymers of long-chain alkyl vinyl ethers and acrylates and copolymers of protocatechuic acid and acrylates, combinations of copolymers of amine compounds and acrylates and copolymers of carbamates and acrylates, combinations of copolymers of aromatic vinyl compounds and acrylates and copolymers of organosilicones and acrylates, or combinations of copolymers of fluorinated monomers and acrylates and copolymers of long-chain alkyl vinyl ethers and acrylates; preferably, copolymers of carbamates and acrylates, and more preferably, polyurethane acrylates.
[0043] Preferably, the compatibilizer comprises any one or a combination of at least two of maleic anhydride graft polymers, acrylate-fluorocarbon polymer block copolymers, or fluorinated surfactants, wherein typical but not limited combinations include combinations of maleic anhydride graft polymers and acrylate-fluorocarbon polymer block copolymers, combinations of fluorinated surfactants and maleic anhydride graft polymers, or combinations of acrylate-fluorocarbon polymer block copolymers and fluorinated surfactants, preferably fluorinated surfactants.
[0044] The coating method described in this invention includes any one of micro-groove coating, wire rod coating, or extrusion coating.
[0045] Preferably, the curing is photocuring.
[0046] Preferably, the water-blocking mixture further includes a photoinitiator.
[0047] Preferably, the absorption wavelength of the photoinitiator is different from that of the ultraviolet absorber.
[0048] Preferably, the amount of photoinitiator added accounts for 0.5% to 5% of the solid mass in the water-blocking mixture, for example, it can be 0.5%, 0.8%, 1%, 2%, 3%, 4% or 5%, etc., but is not limited to the listed values. Other unlisted values within this range are also applicable.
[0049] Preferably, the base film comprises an acrylate polymer resin film.
[0050] The present invention does not limit the manufacturing method of the base film, for example, it can be stretched into a film by resin hot melt extrusion.
[0051] Preferably, the adhesive layer comprises an isocyanate crosslinking agent.
[0052] Preferably, the adhesive layer may or may not include an ultraviolet absorber.
[0053] The adhesive layer described in this invention can be coated and cured onto a base film, such as by methods like microgravure coating, wire rod coating, or extrusion coating, using either thermosetting or photocuring.
[0054] In a second aspect, the present invention also provides a polarizing plate, the polarizing plate comprising the high water-resistant optical film described in the first aspect.
[0055] The polarizing plate of the present invention includes a PVA film and a high water-resistant optical film disposed on one or two surfaces of the PVA film; the polarizing plate may also include other film layers such as an outer protective film, adhesive, and release film.
[0056] Compared with the prior art, the present invention has at least the following beneficial effects:
[0057] (1) The high water-blocking optical film provided by the present invention has excellent hydrophobicity. The polyvinylidene fluoride resin in the raw materials has the characteristic of low surface energy, which makes it difficult for water molecules to adhere to and diffuse on its surface. The modified acrylate polymer provides good film-forming properties and stability for the overall structure. The two are closely combined to form an effective hydrophobic barrier. At the same time, the uniform and orderly arranged nano-protrusions and microporous structure on the surface of the water-blocking layer further enhance the hydrophobicity. This microstructure makes water droplets appear as near spherical on the film surface, thereby greatly reducing the possibility of water wetting and penetration on the film surface, ensuring the stability and reliability of the optical film in a humid environment, and effectively preventing the internal components or materials of the equipment using the optical film from deteriorating or being damaged due to moisture.
[0058] (2) The ultraviolet absorber added to the water-blocking layer raw material of the high water-blocking optical film provided by the present invention can efficiently absorb ultraviolet radiation, effectively prevent the optical film from aging, yellowing, embrittlement and other problems caused by ultraviolet radiation, significantly extend the service life of the optical film, ensure that it can maintain good optical performance, mechanical performance and barrier performance in long-term outdoor use or in environments with strong light, maintain stable light transmittance and low haze, and ensure the performance stability and appearance integrity of the equipment or products using the optical film, providing a solid guarantee for its application in fields with high requirements for optical performance and durability, such as displays and touch screens. Attached Figure Description
[0059] Figure 1 This is a schematic diagram of the high water-resistant optical film in Embodiment 1 of the present invention.
[0060] Figure 2 This is a schematic diagram of the high water-resistant optical film in Embodiment 2 of the present invention.
[0061] Figure 3 This is a schematic diagram of the optical film structure in Comparative Example 1 of the present invention.
[0062] Figure 4 This is a schematic diagram of the polarizing plate in Application Example 1 of the present invention.
[0063] Figure 5 This is a schematic diagram of the polarizing plate in Application Example 2 of the present invention.
[0064] In the diagram: 10 - water-blocking layer; 20 - first adhesive layer; 30 - base film; 40 - second adhesive layer; 100 - high water-blocking optical film; 200 - PVA film; 300 - outer protective film. Detailed Implementation
[0065] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments.
[0066] The present invention will now be described in further detail. However, the examples described below are merely simplified examples of the present invention and do not represent or limit the scope of protection of the present invention. The scope of protection of the present invention is determined by the claims.
[0067] It should be understood that in the description of this invention, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.
[0068] It should be noted that, in the description of this invention, unless otherwise explicitly specified and limited, the terms "set," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.
[0069] Example 1
[0070] This embodiment provides a high water-blocking optical film. The structure of the high water-blocking optical film includes a water-blocking layer 10, a first adhesive layer 20, a base film 30, and a second adhesive layer 40 stacked sequentially, as shown in the schematic diagram below. Figure 1 As shown.
[0071] The thickness of the base film 30 is 40 μm; the thickness of the water-blocking layer 10 is 5 μm; the thickness of the first adhesive layer 20 is 500 nm; and the thickness of the second adhesive layer 40 is 500 nm.
[0072] The surface of the water-blocking layer 10 has uniformly and orderly arranged nanoprotrusions and microporous structures. The height of the nanoprotrusions is 100 nm. The pore size of the microporous structure is 50 nm.
[0073] The water-blocking layer 10 is formed by coating and curing a water-blocking mixture.
[0074] The water-blocking mixture contains 60% solvent by mass; the solvent is toluene; by mass fraction, the solids in the water-blocking mixture include 60% modified acrylate polymer, 20% polyvinylidene fluoride resin, 4% UV absorber, 1% aziridine crosslinking agent, 1.5% polyether-modified silicone defoamer, 0.5% citric acid, 5% phenolic hydroxyl compound, and 8% compatibilizer. The modified acrylate polymer is a copolymer of urethane and acrylate, specifically polyurethane acrylate.
[0075] The phenolic hydroxy compound is pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate];
[0076] The compatibilizer is a fluorinated surfactant, specifically a perfluoropolyether modified acrylate.
[0077] The curing process is photocuring; the water-blocking mixture also includes the photoinitiator Omnirad 907; the absorption wavelength of the photoinitiator is different from that of the ultraviolet absorber; the amount of the photoinitiator added accounts for 0.5% to 5% of the solid mass in the water-blocking mixture.
[0078] The base film 30 is an acrylic polymer resin film formed by hot melt extrusion and stretching.
[0079] The first adhesive layer 20 and the second adhesive layer 40 include an isocyanate crosslinking agent, specifically hexamethylene diisocyanate; the first adhesive layer 20 also includes a benzotriazole ultraviolet absorber, specifically UV-P; the second adhesive layer 40 does not contain an ultraviolet absorber.
[0080] Example 2
[0081] This embodiment provides a high water-blocking optical film. The structure of the high water-blocking optical film includes a water-blocking layer 10, a base film 30, and a second adhesive layer 40 stacked sequentially, as shown in the schematic diagram below. Figure 2 As shown, the rest are the same as in Example 1.
[0082] Example 3
[0083] This embodiment provides a high water-blocking optical film, which is the same as in Example 1 except that the water-blocking mixture forming the water-blocking layer does not contain polyvinylidene fluoride resin.
[0084] Example 4
[0085] This embodiment provides a high water-blocking optical film, which is the same as in Example 1 except that the water-blocking mixture forming the water-blocking layer does not contain modified acrylate polymer.
[0086] Comparative Example 1
[0087] This comparative example provides an optical film, the structure of which includes a base film 30 and a second adhesive layer 40 stacked sequentially, as shown in the schematic diagram below. Figure 3 As shown. The base film 30 is a conventional acrylic resin hot melt extrusion film with a thickness of 40 μm, and the rest is the same as in Example 1.
[0088] Comparative Example 2
[0089] This comparative example provides a high water-blocking optical film. The structure of the high water-blocking optical film includes a water-blocking layer 10, a base film 30, and a second adhesive layer 40 stacked sequentially. Except that the water-blocking layer 10 has a smooth and flat surface, the rest is the same as in Example 2.
[0090] The optical films in the above embodiments and comparative examples were subjected to the following tests:
[0091] Humidity permeability: Add 30g±0.1g(m0) of desiccant to the permeation cup, cover the cup mouth with an optical film of area S, where S = cup mouth area, and then place the permeation cup sealed with the optical film into a constant temperature and humidity chamber at 60℃ and 90% for 24 hours. After that, take it out and confirm the weight m of the desiccant. Humidity permeability = (m-m0) / S.
[0092] Haze: The sample was measured using an NDK-manufactured haze meter NDH8000;
[0093] 380nm transmittance: The sample was measured using a JASCO VAP-8010 visible spectrophotometer;
[0094] Water contact angle: The contact angle meter Dmo-502 manufactured by Kyowa was used to measure the water droplet on the surface of the water-blocking layer; the measurement results are shown in Table 1.
[0095] Table 1
[0096]
[0097]
[0098] In Table 1, "OK" in the overall evaluation indicates that the water-blocking and optical properties of the optical film meet the usage requirements; "NG" indicates that one or both of the water-blocking or optical properties of the optical film do not meet the usage requirements.
[0099] As can be seen from Table 1:
[0100] (1) As can be seen from the comprehensive examples 1 to 2, the high water-blocking optical film provided by the present invention has better water-blocking performance, and the addition of ultraviolet absorber to the water-blocking layer can efficiently absorb ultraviolet radiation, effectively preventing problems such as aging, yellowing, and embrittlement of the optical film caused by ultraviolet radiation.
[0101] (2) As can be seen from Examples 1 and 3-4, since the water-blocking mixture forming the water-blocking layer in Example 3 does not contain polyvinylidene fluoride resin, the water-blocking effect of the water-blocking layer will be worse, and the water permeability of the high water-blocking optical film will become 149 g / m³. 2 / day, and the water contact angle also becomes smaller, at 72.5°, and its water-blocking performance does not meet the requirements for use; since the water-blocking mixture forming the water-blocking layer in Example 4 does not contain modified acrylate polymer, the transparency of the water-blocking layer will become worse, the transmittance of the high water-blocking optical film becomes 82.3%, and the haze is 1.8%, and its optical performance does not meet the requirements for use.
[0102] (3) Combining Example 1 and Comparative Example 1, it can be seen that the optical film in Comparative Example 1 does not have a water-blocking layer, resulting in a significant reduction in water-blocking effect, and the moisture permeability of the optical film becomes 168 g / m². 2 / day, and the 380nm transmittance becomes 89.7%, and the water contact angle becomes 68.1°, its water-blocking performance does not meet the usage requirements;
[0103] (4) As can be seen from the comparison of Example 2 and Comparative Example 2, the water-blocking layer in Comparative Example 2 has a smooth and flat surface, which leads to a decrease in the hydrophobicity of the optical film. Water droplets can penetrate into the water-blocking layer, resulting in a significant reduction in the water-blocking effect. The water permeability of the optical film becomes 132 g / m³. 2 / day, and the water contact angle becomes 78.8°, its water-blocking performance does not meet the usage requirements.
[0104] Application Example 1
[0105] This application example provides a polarizing plate, which includes the high water-resistant optical film 100 from Example 1. The polarizing plate has a structure consisting of a high water-resistant optical film 100, a PVA film 200, and an outer protective film 300 stacked sequentially, as shown in the schematic diagram below. Figure 4 As shown.
[0106] Application Example 2
[0107] This application example provides a polarizing plate, which includes the high water-resistant optical film 100 from Example 1. The polarizing plate has a structure in which the high water-resistant optical film 100, the PVA film 200, and the high water-resistant optical film 100 are stacked sequentially, as shown in the schematic diagram below. Figure 5 As shown.
[0108] In summary, the high water-blocking optical film provided by this invention has excellent hydrophobicity, and the water-blocking layer can efficiently absorb ultraviolet radiation, effectively preventing problems such as aging, yellowing, and embrittlement of the optical film caused by ultraviolet radiation. The high water-blocking optical film of this invention can be applied to polarizing plates, significantly improving the service life of polarizing plates.
[0109] The applicant declares that the above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.
Claims
1. A high water-resistant optical film, characterized in that, The high water-blocking optical film includes a base film, a water-blocking layer, and an adhesive layer; The high water-blocking optical film has a structure comprising a water-blocking layer, a first adhesive layer, a base film and a second adhesive layer stacked sequentially, or a water-blocking layer, a base film and a second adhesive layer stacked sequentially. The surface of the water-blocking layer has a uniform and orderly arranged nanoprotrusion and microporous structure. The high water-resistant optical film has a haze of less than 1% and a water permeability of <130g / m at 60℃ and 90%RH. 2 / day; The surface contact angle of the water-blocking layer is 80° or more; The water-blocking layer is formed by coating and curing a water-blocking mixture. The mass fraction of the solvent in the water-blocking mixture is 40%~70%; By mass fraction, the solids in the water-blocking mixture include 30% to 60% modified acrylate polymer, 15% to 30% polyvinylidene fluoride resin, 2% to 6% ultraviolet absorber, 1% to 3% aziridine crosslinking agent, 0.5% to 1.5% polyether modified silicone defoamer, 0.1% to 0.5% citric acid, 2% to 5% phenolic hydroxyl compound and 3% to 8% compatibilizer; The modified acrylate polymer is a polyurethane acrylate; The adhesive layer includes an isocyanate crosslinking agent; The base film includes an acrylate polymer resin film.
2. The high water-resistant optical film according to claim 1, characterized in that, The thickness of the base film is 20~80μm.
3. The high water-resistant optical film according to claim 1, characterized in that, The thickness of the water-blocking layer is 0.1~10μm.
4. The high water-resistant optical film according to claim 1, characterized in that, The thickness of the adhesive layer is 200~1000nm.
5. The high water-resistant optical film according to claim 1, characterized in that, The height of the nanoprotrusions is 50~300nm.
6. The high water-resistant optical film according to claim 1, characterized in that, The pore size of the microporous structure is 30~300nm.
7. The high water-resistant optical film according to claim 1, characterized in that, The solvent includes any one or a combination of at least two of toluene, acetone, butanone, or dimethyl carbonate.
8. The high water-resistant optical film according to claim 1, characterized in that, The compatibilizer includes any one or a combination of at least two of maleic anhydride graft polymers, acrylate-fluorocarbon polymer block copolymers, or fluorinated surfactants.
9. The high water-resistant optical film according to claim 8, characterized in that, The compatibilizer is a fluorinated surfactant.
10. The high water-resistant optical film according to claim 1, characterized in that, The curing process is photocuring.
11. The high water-resistant optical film according to claim 1, characterized in that, The water-blocking mixture also includes a photoinitiator.
12. The high water-resistant optical film according to claim 11, characterized in that, The absorption wavelength of the photoinitiator is different from that of the ultraviolet absorber.
13. The high water-resistant optical film according to claim 11, characterized in that, The amount of photoinitiator added accounts for 0.5% to 5% of the solid mass in the water-blocking mixture.
14. The high water-resistant optical film according to claim 1, characterized in that, The adhesive layer may or may not include an ultraviolet absorber.
15. A polarizing plate, characterized in that, The polarizing plate includes the high water-resistant optical film according to any one of claims 1 to 14.