High-water-resistance optical film and polarizing plate comprising same

Abstract

The invention provides a high-water-resistance optical film and a polarizing plate comprising the same. The high-water-resistance optical film comprises a base film, a water-resistance layer and an adhesive layer, the structure of the high-water-resistance optical film comprises a water-resistance layer, a first adhesive layer, a base film and a second adhesive layer which are stacked in sequence, or the water-resistance layer, the base film and the second adhesive layer which are stacked in sequence, the surface of the waterproof layer is provided with nanometer protrusions and micropore structures which are uniformly and orderly arranged. The high-water-resistance optical film has excellent hydrophobicity, the water-resistance layer can efficiently absorb ultraviolet radiation, the problems of aging, yellowing, embrittlement and the like of the optical film caused by ultraviolet radiation are effectively prevented, the high-water-resistance optical film can be applied to a polarizing plate, and the service life of the polarizing plate is greatly prolonged.

Description

Technical Field

[0001] The present invention relates to the technical field of optical films, and in particular to a high water-resistance optical film and a polarizing plate comprising the same. Background Art

[0002] With the rapid development of modern science and technology, optical films play an indispensable and key role in many fields such as displays, touch screens, etc. In these application scenarios, optical films not only need to have excellent optical properties, but also have extremely stringent requirements on their barrier properties, especially water barrier 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 sensitive components and materials inside. For LCDs, moisture can cause deterioration of liquid crystal materials, corrosion of electrodes, and degradation of polarizer performance, leading to problems such as uneven display, color deviation, reduced contrast, and even screen failure. In OLEDs, moisture can chemically react with organic light-emitting materials, significantly shortening their service life and causing defects such as black spots and bright spots, which seriously affect display quality and product reliability.

[0004] In terms of touch screen technology, whether it is a capacitive touch screen or a resistive touch screen, water penetration may change the electrical performance and surface characteristics of the touch screen. For example, it may cause a decrease in touch sensitivity, inaccurate positioning, or even failure of the touch function, greatly reducing the user experience and the market competitiveness of the product.

[0005] However, traditional optical films often fail to meet the growing demand for water-blocking properties. Some conventional optical films have high water permeability in high temperature and high humidity environments and cannot provide adequate protection for the devices or products they are applied to. For example, some common polymer-based optical films, due to the limitations of their molecular structure and microscopic morphology, allow water molecules to pass through the film layer relatively easily, resulting in a higher risk of moisture exposure during use of the device.

[0006] At the same time, in the pursuit of high water-blocking performance, the optical properties of the optical film cannot be ignored. Many materials or treatment methods with good water-blocking performance may increase the haze of the optical film and reduce its transparency and glossiness, which is unacceptable for applications that require extremely high optical clarity. For example, although some inorganic water-blocking coatings have good water-blocking effects, due to factors such as their crystal structure or surface roughness, they are prone to scattering light, resulting in increased haze of the optical film, which cannot meet the strict requirements for low haze of optical films in fields such as high-definition display.

[0007] CN113249062A discloses an adhesive composition, an adhesive, an adhesive sheet and an optical film with an adhesive layer, wherein the adhesive composition contains a (meth) acrylate polymer (A), wherein in the molecular weight distribution of the (meth) acrylate polymer (A) measured by gel permeation chromatography, the amount of the component having a molecular weight of 3 million or more is less than 15% by mass, and the peak molecular weight (Mp) is more than 800,000 and less than 1.2 million, and furthermore, the viscosity of the (meth) acrylate polymer (A) when dissolved in a mixed solvent of ethyl acetate and acetone containing 85% by mass of ethyl acetate in a manner of 20% by mass is more than 5000mPa·s and less than 10000mPa·s. The adhesive, the adhesive sheet and the optical film with an adhesive layer have excellent durability, and good processability when the adhesive composition is applied.

[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 remainder of water. The polarizing plate is located between the optical film and the primer layer formed by the primer composition. The method comprises 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 adhesive properties and can be included in the polarizing plate without reducing the transparency of the polarizing plate and without requiring additional processes or equipment.

[0009] CN104356967A discloses a UV-curable polyolefin optical film and a preparation method thereof. The UV-curable polyolefin optical film is prepared by pre-mixing 100 parts of ethylene-octene copolymer, 0.1-2 parts of hydroxyl-containing acrylate monomer, 0.3-2 parts of photoinitiator, 0-1.0 parts of co-crosslinking agent, 0.05-0.5 parts of light stabilizer, 0.05-0.5 parts of antioxidant, and 0-1.0 parts of coupling agent in parts by weight in a conical stirrer and then casting. The preparation method has simple procedures, convenient processing, easy operation, and 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 performance, insulation performance, bonding performance, and non-corrosive performance.

[0010] However, the water barrier properties of the above optical films need to be further improved. Summary of the invention

[0011] In view of the problems existing in the prior art, the present invention provides a high water-resistance optical film and a polarizing plate containing the same. The high water-resistance optical film has a water-resistance 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 to which it is applied.

[0012] To achieve this object, the present invention adopts the following technical solutions:

[0013] In a first aspect, the present invention provides a high water-resistance optical film, the high water-resistance optical film comprising a base film, a water-resistance layer and a bondable layer;

[0014] The structure of the high water-resistant optical film comprises a water-resistant layer, a first adhesive layer, a base film and a second adhesive layer stacked in sequence, or a water-resistant layer, a base film and a second adhesive layer stacked in sequence;

[0015] The surface of the water-blocking layer has uniform and orderly arranged nano-protrusions and micro-pore structures;

[0016] The haze of the high water-resistance optical film is less than 1%; the water permeability at 60°C and 90% RH is less than 130g / m 2 / day; the surface contact angle of the water-blocking layer is greater than 80°.

[0017] The high water-resistance optical film of the present invention comprises a base film, a water-resistance layer and a bonding layer, wherein the bonding layer can be arranged on one side or both sides of the base film. The optical film of the present invention is provided with a water-resistance layer, which exhibits excellent hydrophobicity; wherein the nano-protrusions and microporous structures significantly enhance the hydrophobicity, and such microstructures make the water droplets on the surface of the optical film present an approximately spherical state, minimizing the contact area with the film, thereby greatly reducing the possibility of water infiltration and penetration on the surface of the film, ensuring the stability and reliability of the optical film in a humid environment, and effectively preventing the performance degradation or damage of the internal components or materials due to moisture. Moreover, the nano-protrusions and microporous structures are arranged uniformly and orderly, ensuring that the haze of the high water-resistance optical film is below 1%, and under the premise of having high water-resistance performance, it does not affect the normal optical performance.

[0018] The nano-protrusions and micro-pore structures on the surface of the water-blocking layer of the present invention are manufactured by nano-imprinting technology and are suitable for large-scale industrial production.

[0019] The adhesive layer in the high water-resistance optical film of the present invention can be provided with one or two layers as required, and the structure of the high water-resistance optical film can be a water-resistance layer, a first adhesive layer, a base film, and a second adhesive layer stacked in sequence, or a water-resistance layer, a base film, and a second adhesive layer stacked in sequence. 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-resistance 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, and other values ​​not listed in the numerical range are also applicable;

[0021] Water permeability at 60°C, 90% RH <130g / m 2 / day, for example, 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 are not limited to the listed values, and other values ​​not listed within the range are also applicable;

[0022] The surface contact angle of the water-blocking layer is greater than 80°, for example, 80°, 81°, 83°, 85°, or 89°, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0023] Preferably, the thickness of the base film is 20 to 80 μm, for example, 20 μm, 30 μm, 40 μm, 50 μm, 60 μm, 70 μm or 80 μm, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0024] Preferably, the thickness of the water-blocking layer is 0.1-10 μm, for example, 0.1 μm, 0.2 μm, 0.5 μm, 1 μm, 3 μm, 5 μm or 10 μm, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0025] Preferably, the thickness of the bondable layer is 200-1000 nm, for example, 200 nm, 300 nm, 400 nm, 500 nm, 700 nm, 900 nm or 1000 nm, but is not limited to the listed values, and other unlisted values ​​within the numerical 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 is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0027] Preferably, the pore size of the microporous structure is 30 to 300 nm, for example, 30 nm, 50 nm, 100 nm, 150 nm, 200 nm, 250 nm or 300 nm, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0028] Preferably, the water-blocking layer is formed by coating and curing a water-blocking mixed liquid.

[0029] Preferably, the mass fraction of the solvent in the water-blocking mixed liquid is 40% to 70%, for example, it can be 40%, 45%, 50%, 55%, 60%, 65% or 70%, etc., but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0030] Preferably, the solvent comprises any one of toluene, acetone, butanone or dimethyl carbonate or a combination of at least two thereof, wherein typical but non-limiting combinations include a combination of toluene and acetone, a combination of butanone and dimethyl carbonate, a combination of toluene and butanone or a combination of dimethyl carbonate and acetone.

[0031] Preferably, the solid matter in the water-blocking mixed liquid includes 30% to 60% of the total solid mass ratio of the modified acrylate polymer, for example, 30%, 35%, 40%, 45%, 50%, 55% or 60%, etc., but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable;

[0032] 15% to 30% of polyvinylidene fluoride resin, for example, 15%, 16%, 18%, 20%, 22%, 25% or 30%, etc., but not limited to the listed values, other values ​​not listed within the numerical range are also applicable;

[0033] 2% to 6% of the ultraviolet absorber, for example, it can be 2%, 2.5%, 3%, 3.5%, 4%, 5% or 6%, etc., but it is not limited to the listed values, and other values ​​not listed within the numerical 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 values ​​not listed within the numerical range are also applicable;

[0035] 0.5% to 1.5% of the 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 values ​​not listed within the range are also applicable;

[0036] 0.1% to 0.5% citric acid, for example, 0.1%, 0.2%, 0.25%, 0.3%, 0.35%, 0.4% or 0.5%, etc., but not limited to the listed values, other values ​​not listed within the range are also applicable;

[0037] 2% to 5% of the phenolic hydroxyl compound, for example, can be 2%, 2.5%, 3%, 3.5%, 4%, 4.5% or 5%, etc., but are not limited to the listed values, and other values ​​not listed within the numerical range are also applicable;

[0038] and 3% to 8% of a compatibilizer, for example, 3%, 3.5%, 4%, 4.5%, 5%, 6% or 8%, etc., but are not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0039] The polyvinylidene fluoride resin in the water-blocking mixed liquid of the present invention has the characteristic of low surface energy, which makes it difficult for water molecules to adhere to and diffuse on its surface, while the modified acrylic polymer provides good film-forming property and stability for the overall structure, and the two cooperate to form an effective hydrophobic barrier. In addition, the ultraviolet absorber can efficiently absorb ultraviolet radiation, effectively prevent the aging, yellowing, embrittlement and other problems of the optical film caused by ultraviolet radiation, significantly extend the service life of the optical film, ensure that it can still maintain good optical properties, mechanical properties and barrier properties in long-term outdoor use or in an environment with strong light, maintain stable light transmittance and low haze, ensure the performance stability and appearance integrity of the equipment or product using the optical film, and provide a solid guarantee for its application in fields such as display screens and touch screens that have high requirements for optical properties and durability.

[0040] The present invention does not limit the ultraviolet absorber, and any one of benzotriazoles, benzophenones or triazines can be selected, preferably benzotriazoles, such as UV-P, which is more beneficial to the transmittance of the optical film.

[0041] The phenolic hydroxy compound of the present invention can be used in combination with an ultraviolet absorber to further enhance the stability of the material. The phenolic hydroxy compound can be pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate.

[0042] Preferably, the modified acrylate polymer includes any one or a combination of at least two of a copolymer of a long-chain alkyl vinyl ether and acrylate, a copolymer of protocatechuic acid and acrylate, a copolymer of an amine compound and acrylate, a copolymer of a carbamate and acrylate, a copolymer of an aromatic vinyl compound and acrylate, a copolymer of an organosilicon and acrylate, or a copolymer of a fluorine-containing monomer and acrylate, wherein a typical but non-limiting combination includes a combination of a copolymer of a long-chain alkyl vinyl ether and acrylate and a copolymer of protocatechuic acid and acrylate, a combination of a copolymer of an amine compound and acrylate and a copolymer of a carbamate and acrylate, a combination of a copolymer of an aromatic vinyl compound and acrylate and a copolymer of an organosilicon and acrylate, or a combination of a copolymer of a fluorine-containing monomer and acrylate and a copolymer of a long-chain alkyl vinyl ether and acrylate; preferably a copolymer of a carbamate and acrylate, and more preferably polyurethane acrylate.

[0043] Preferably, the compatibilizer comprises any one or a combination of at least two of a maleic anhydride grafted polymer, an acrylate-fluorocarbon polymer block copolymer or a fluorinated surfactant, wherein typical but non-limiting combinations include a combination of a maleic anhydride grafted polymer and an acrylate-fluorocarbon polymer block copolymer, a combination of a fluorinated surfactant and a maleic anhydride grafted polymer or a combination of an acrylate-fluorocarbon polymer block copolymer and a fluorinated surfactant, preferably a fluorinated surfactant.

[0044] The coating method of the present invention includes any one of micro-dimple coating, wire rod coating or extrusion coating.

[0045] Preferably, the curing is photocuring.

[0046] Preferably, the water-blocking mixed liquid also includes a photoinitiator.

[0047] Preferably, the absorption wavelength of the photoinitiator is different from the absorption wavelength of the ultraviolet absorber.

[0048] Preferably, the amount of the photoinitiator added accounts for 0.5% to 5% of the solid matter 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, and other unlisted values ​​within the numerical range are also applicable.

[0049] Preferably, the base film includes an acrylate polymer resin film.

[0050] The present invention does not limit the manufacturing method of the base film. For example, the base film can be formed by hot-melt extrusion of resin.

[0051] Preferably, the bondable layer includes an isocyanate-based cross-linking agent.

[0052] Preferably, the bondable layer includes or excludes a UV absorber.

[0053] The adhesive layer of the present invention can be cured to the base film by coating, such as micro-dimpled coating, wire rod coating, extrusion coating and the like, using heat curing or light curing.

[0054] In a second aspect, the present invention further provides a polarizing plate, wherein the polarizing plate comprises the high-resistance water optical film described in the first aspect.

[0055] The polarizing plate of the present invention comprises a PVA film and a high water-resistance optical film disposed on one or both surfaces of the PVA film; the polarizing plate may further comprise other film layers such as an outer protective film, an adhesive, and a release film.

[0056] Compared with the prior art, the present invention has at least the following beneficial effects:

[0057] (1) The high water-resistant optical film provided by the present invention has excellent hydrophobicity. The polyvinylidene fluoride resin in the constituent raw materials itself has the characteristic of low surface energy, which makes it difficult for water molecules to adhere to and diffuse on its surface, while the modified acrylate polymer provides good film-forming property 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 structures on the surface of the water-resistant layer further enhance the hydrophobicity. This microstructure makes the water droplets on the surface of the film appear in a state of approximately spherical shape, thereby greatly reducing the possibility of water infiltration and penetration on the surface of the film, 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 raw material of the water-blocking layer of the high water-blocking optical film provided by the present invention can efficiently absorb ultraviolet radiation, effectively preventing the optical film from aging, yellowing, brittleness and other problems caused by ultraviolet radiation, significantly extending the service life of the optical film, ensuring that it can still maintain good optical properties, mechanical properties and barrier properties under long-term outdoor use or in an environment with strong light, maintain stable light transmittance and low haze, and ensure the performance stability and appearance integrity of the equipment or product using the optical film, providing a solid guarantee for its application in fields such as display screens and touch screens that have high requirements for optical properties and durability. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] Figure 1 It is a schematic diagram of the structure of the high water-resistance optical film in Example 1 of the present invention.

[0060] Figure 2 It is a schematic diagram of the structure of the high water-resistance optical film in Example 2 of the present invention.

[0061] Figure 3 It is a schematic diagram of the structure of the optical film in Comparative Example 1 of the present invention.

[0062] Figure 4 It is a schematic diagram of the structure of the polarizing plate in Application Example 1 of the present invention.

[0063] Figure 5 It is a schematic structural diagram of the polarizing plate in Application Example 2 of the present invention.

[0064] In the figure: 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 DESCRIPTION

[0065] The technical solution of the present invention is further described below with reference to the accompanying drawings and through specific implementation methods.

[0066] The present invention is further described in detail below. However, the following examples are only 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 shall be subject to the claims.

[0067] It should be understood that, in the description of the present invention, the terms "first", "second", etc. are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0068] It should be noted that in the description of the present invention, unless otherwise clearly specified and limited, the terms "disposed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood by specific circumstances.

[0069] Example 1

[0070] This embodiment provides a high water-resistance optical film, the structure of which includes a water-resistance layer 10, a first adhesive layer 20, a base film 30 and a second adhesive layer 40 stacked in sequence, and its structural schematic diagram is shown as follows: Figure 1 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 bondable layer 20 is 500 nm; and the thickness of the second bondable layer 40 is 500 nm.

[0072] The surface of the water-blocking layer 10 has uniform and orderly arranged nano protrusions and microporous structures. The height of the nano protrusions 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 mixed liquid;

[0074] The mass fraction of the solvent in the water-blocking mixed liquid is 60%; the solvent is toluene; by mass fraction, the solid matter in the water-blocking mixed liquid includes 60% modified acrylate polymer, 20% polyvinylidene fluoride resin, 4% ultraviolet absorber, 1% aziridine crosslinker, 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 carbamate 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 fluorine-containing surfactant, specifically perfluoropolyether modified acrylate.

[0077] The curing is photocuring; the water-blocking mixed liquid also includes a 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 matter in the water-blocking mixed liquid.

[0078] The base film 30 is an acrylic polymer resin film formed by hot-melt extrusion and stretching;

[0079] The first bondable layer 20 and the second bondable layer 40 include an isocyanate crosslinking agent, specifically hexamethylene diisocyanate; the first bondable layer 20 also includes a benzotriazole ultraviolet absorber, specifically UV-P; and the second bondable layer 40 does not include an ultraviolet absorber.

[0080] Example 2

[0081] This embodiment provides a high water-resistance optical film, the structure of which includes a water-resistance layer 10, a base film 30 and a second adhesive layer 40 stacked in sequence, and its structural schematic diagram is shown as follows: 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 the first embodiment except that the water-blocking mixed solution forming the water-blocking layer does not contain polyvinylidene fluoride resin.

[0084] Example 4

[0085] This embodiment provides a highly water-resistant optical film, which is the same as the first embodiment except that the water-resistant mixed solution for forming the water-resistant layer does not contain a modified acrylic ester polymer.

[0086] Comparative Example 1

[0087] This comparative example provides an optical film, wherein the optical film structure comprises a base film 30 and a second adhesive layer 40 which are stacked in sequence. Figure 3 The base film 30 is a conventional acrylic resin film formed by hot melt extrusion and stretching, with a thickness of 40 μm, and the rest is the same as that of Example 1.

[0088] Comparative Example 2

[0089] This comparative example provides a high water-resistance optical film, the structure of which includes a water-resistance layer 10, a base film 30 and a second bondable layer 40 stacked in sequence, and the water-resistance layer 10 has a smooth and flat surface, and the rest is the same as Example 2.

[0090] The optical films in the above embodiments and comparative examples were subjected to the following tests:

[0091] Moisture permeability: add 30g±0.1g (m0) desiccant into the moisture permeable cup, cover the cup mouth with an optical film of area S, S = cup mouth area, then put the moisture permeable cup sealed with optical film into a constant temperature and humidity machine at 60℃ and 90%, take it out after 24 hours, confirm the desiccant weight m, moisture permeability = (m-m0) / S;

[0092] Haze: The sample was placed in the haze meter NDH8000 manufactured by NDK for measurement;

[0093] 380nm transmittance: The sample was placed in a visible spectrophotometer VAP-8010 manufactured by JASCO for measurement;

[0094] Water contact angle: The contact angle meter Dmo-502 manufactured by Kyowa was used to measure the water droplets 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 means that both the water barrier performance and the optical performance of the optical film meet the use requirements; "NG" means that one or both of the water barrier performance or the optical performance of the optical film do not meet the use requirements.

[0099] From Table 1 we can see that:

[0100] (1) It can be seen from Examples 1 to 2 that the high water-blocking optical film provided by the present invention has excellent water-blocking performance, and the addition of an ultraviolet absorber in the water-blocking layer can efficiently absorb ultraviolet radiation, effectively preventing the optical film from aging, yellowing, embrittlement, and other problems caused by ultraviolet radiation;

[0101] (2) Combining Example 1 with Examples 3 to 4, it can be seen that since the water-blocking mixed solution forming the water-blocking layer in Example 3 does not contain polyvinylidene fluoride resin, the water-blocking effect of the water-blocking layer is deteriorated, and the moisture permeability of the high water-blocking optical film becomes 149 g / m 2 / day, and the water contact angle also becomes smaller, which is 72.5°, and its water-blocking performance does not meet the use requirements; since the water-blocking mixed liquid forming the water-blocking layer in Example 4 does not contain a modified acrylate polymer, the transparency of the water-blocking layer will deteriorate, and the transmittance of the high water-blocking optical film will become 82.3%, and the haze will be 1.8%, and its optical performance does not meet the use requirements;

[0102] (3) From the perspective of Example 1 and Comparative Example 1, it can be seen that the optical film of Comparative Example 1 does not have a water-blocking layer, and the water-blocking effect is greatly reduced, and the moisture permeability of the optical film becomes 168 g / m 2 / day, and the transmittance at 380nm becomes 89.7%, and the water contact angle becomes 68.1°, and its water barrier performance does not meet the use requirements;

[0103] (4) It can be seen from the combination of Example 2 and Comparative Example 2 that the water-blocking layer of Comparative Example 2 has a smooth and flat surface, which will lead to a decrease in the hydrophobicity of the optical film. Water droplets will penetrate into the water-blocking layer, resulting in a significant decrease in the water-blocking effect. The moisture permeability of the optical film becomes 132 g / m 2 / day, and the water contact angle becomes 78.8°, and its water barrier performance does not meet the use requirements.

[0104] Application Example 1

[0105] This application example provides a polarizing plate, which includes the high-resistance water optical film 100 in Example 1. The structure of the polarizing plate is a high-resistance water optical film 100, a PVA film 200 and an outer protective film 300 stacked in sequence. The schematic diagram of the structure is shown in FIG. Figure 4 shown.

[0106] Application Example 2

[0107] This application example provides a polarizing plate, which includes the high-resistance water optical film 100 in Example 1. The structure of the polarizing plate is a high-resistance water optical film 100, a PVA film 200 and a high-resistance water optical film 100 stacked in sequence, and its structural schematic diagram is shown as follows Figure 5 shown.

[0108] In summary, the high water-resistance optical film provided by the present invention has excellent hydrophobicity, and the water-resistance layer can efficiently absorb ultraviolet radiation, effectively preventing the optical film from aging, yellowing, embrittlement and other problems caused by ultraviolet radiation; the high water-resistance optical film of the present invention can be applied to polarizing plates, greatly improving the service life of polarizing plates.

[0109] The applicant declares that the above is only a specific implementation mode 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 thought of by those skilled in the art within the technical scope disclosed by the present invention shall fall within the protection scope and disclosure scope of the present invention.

Claims

1. A high water-resistance optical film, characterized in that: The high water-resistance optical film comprises a base film, a water-resistance layer and a bondable layer; The structure of the high water-resistant optical film comprises a water-resistant layer, a first adhesive layer, a base film and a second adhesive layer stacked in sequence, or a water-resistant layer, a base film and a second adhesive layer stacked in sequence; The surface of the water-blocking layer has uniform and orderly arranged nano-protrusions and micro-pore structures; The haze of the high water-resistance optical film is less than 1%; the water permeability at 60°C and 90% RH is less than 130g / m 2 / day; the surface contact angle of the water-blocking layer is greater than 80°.

2. The high-resistance water optical film according to claim 1, characterized in that: The thickness of the base film is 20 to 80 μm; Preferably, the thickness of the water-blocking layer is 0.1 to 10 μm; Preferably, the thickness of the bondable layer is 200-1000 nm.

3. The high-resistance water optical film according to claim 1 or 2, characterized in that: The height of the nanoprotrusions is 50 to 300 nm; Preferably, the pore size of the microporous structure is 30-300 nm.

4. The high-resistance water optical film according to any one of claims 1 to 3, characterized in that: The water-blocking layer is formed by coating and curing the water-blocking mixed liquid; Preferably, the mass fraction of the solvent in the water-blocking mixed liquid is 40% to 70%; Preferably, the solvent comprises any one of toluene, acetone, butanone or dimethyl carbonate or a combination of at least two thereof; Preferably, the solid matter in the water-blocking mixture includes, by mass fraction, 30% to 60% of modified acrylate polymer, 15% to 30% of polyvinylidene fluoride resin, 2% to 6% of ultraviolet absorber, 1% to 3% of aziridine crosslinking agent, 0.5% to 1.5% of polyether modified silicone defoamer, 0.1% to 0.5% of citric acid, 2% to 5% of phenolic hydroxyl compound and 3% to 8% of compatibilizer.

5. The high-resistance water optical film according to claim 4, characterized in that: The modified acrylate polymer includes any one or a combination of at least two of a copolymer of a long-chain alkyl vinyl ether and acrylate, a copolymer of protocatechuic acid and acrylate, a copolymer of an amine compound and acrylate, a copolymer of a carbamate and acrylate, a copolymer of an aromatic vinyl compound and acrylate, a copolymer of an organosilicon and acrylate, or a copolymer of a fluorine-containing monomer and acrylate, preferably a copolymer of a carbamate and acrylate, and more preferably polyurethane acrylate.

6. The high-resistance water optical film according to claim 4, characterized in that: The compatibilizer includes any one of maleic anhydride grafted polymer, acrylate-fluorocarbon polymer block copolymer or fluorine-containing surfactant or a combination of at least two thereof, preferably a fluorine-containing surfactant.

7. The high-resistance water optical film according to claim 4, characterized in that: The curing is photocuring.

8. The high-resistance water optical film according to claim 7, characterized in that: The water-blocking mixed liquid also includes a photoinitiator; Preferably, the absorption wavelength of the photoinitiator is different from the absorption wavelength of the ultraviolet absorber; Preferably, the amount of the photoinitiator added accounts for 0.5% to 5% of the solid matter in the water-blocking mixed liquid.

9. The high-resistance water optical film according to any one of claims 1 to 8, characterized in that: The bondable layer includes an isocyanate cross-linking agent; Preferably, the base film comprises an acrylate polymer resin film; Preferably, the bondable layer includes or excludes a UV absorber.

10. A polarizing plate, characterized in that: The polarizing plate comprises the high-resistance water optical film according to any one of claims 1 to 9.

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