Water-repellent, fluorine-containing, semi-transparent cured film

Abstract

To provide a cured film having both high water repellency and high durability and having translucency.SOLUTION: This invention relates to a water-repellent fluorine-containing translucent cured film, wherein inorganic oxide particles having a grain diameter of 200 nm or less are contained in a cured film of a curable composition comprising a fluorine-containing polymerizable compound and a fluorine-free polymerizable compound.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a novel water-repellent, fluorine-containing, semi-transparent cured film. [Background technology]

[0002] Various water-repellent coating agents are sometimes used to impart water repellency to the surfaces of various materials, such as electronic materials, medical materials, packaging materials, building materials, and clothing. Many compositions containing fluororesins or fluorine compounds are known as such water-repellent coating agents. Among these, a technique has been proposed in which unevenness is imparted to the surface of a coating film to be formed, thereby achieving even higher water repellency.

[0003] For example, a water-repellent coating composition is known that contains a resin solution containing a first fluororesin that can be solidified by drying, and a particle component of a second fluororesin (Patent Document 1).

[0004] Furthermore, for example, a cured film having an uneven surface has been proposed, which is formed using a curable composition containing a compound having a perfluoropolyether group and a curable site, and a curable resin and / or a curable monomer, and further using a mold having an uneven structure (Patent Document 2). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-216585 [Patent Document 2] JP 2019-2014 A Summary of the Invention [Problem to be solved by the invention]

[0006] However, the method of Patent Document 1 does not provide sufficient durability of the coating film, and when the surface is repeatedly rubbed, the bonding strength between the fine particles and between the fine particles and the resin matrix is ​​weak, so the fine particles may peel off, causing the uneven surface structure to be lost over time and resulting in a decrease in water repellency.

[0007] Furthermore, since the method of Patent Document 1 uses white micro-sized PTFE resin particles, even if a transparent PET film or the like is used as the base film, the film becomes opaque, and there are limitations on the designs that can be used.

[0008] Furthermore, the method of Patent Document 2 requires the use of a mold to create the irregularities, and therefore, without such equipment, it is impossible to form a cured film with high water repellency. Moreover, since the irregularities are caused by the cured film itself, there is also a risk that the irregularities will be reduced or disappear over time due to wear. On the other hand, if the predetermined irregularities are not formed in such a cured film, high water repellency (particularly a contact angle with water of 150 degrees or more) cannot be obtained.

[0009] Thus, there is a need for the development of technology that will ensure that high water repellency is maintained, but at present such technology has not yet been developed.

[0010] Therefore, a main object of the present invention is to provide a cured film that has both high water repellency and durability, and also has transparency. [Means for solving the problem]

[0011] As a result of extensive research conducted in light of the problems of the prior art, the present inventors discovered that the above object can be achieved by employing a composition that can provide a coating film having a specific structure, and thus completed the present invention.

[0012] That is, the present invention relates to the following water-repellent fluorine-containing translucent cured film. 1. A water-repellent, fluorine-containing, translucent cured film, characterized in that the cured film is made from a curable composition containing a fluorine-containing polymerizable compound and a fluorine-free polymerizable compound and contains inorganic oxide fine particles having a particle size of 200 nm or less. 2. The arithmetic mean roughness (R a ) is 0.05μm or more and 1.00μm or less, and the maximum height roughness (R z ) is 0.50 μm or more and 10.00 μm or less, and the average length of the element (R sm 2. The water-repellent, fluorine-containing, translucent cured film according to Item 1, wherein the average particle size is 50.0 μm or more and 1000.0 μm or less. 3. The arithmetic mean surface height (S) within a square plane of 555.8 μm × 555.8 μm was determined by observing the surface of the cured film using a white light interference microscope. a ) is 0.01 μm or more and 2.00 μm or less, and the root mean square height (S q ) is 0.05 μm or more and 3.00 μm or less, and the maximum cross-sectional height (S t 3. The water-repellent, fluorine-containing, translucent cured film according to item 1 or 2, wherein the value of (a) is 1.00 μm or more and 30.00 μm or less. 4. The water-repellent, fluorine-containing translucent cured film according to any one of items 1 to 3, wherein the fluorine concentration at the surface of the cured film as determined by XPS analysis is 5 to 50 atomic %. 5. The water-repellent, fluorine-containing translucent cured film according to any one of items 1 to 4, wherein the fluorine-containing polymerizable compound is perfluoropolyether (meth)acrylate. 6. The water-repellent, fluorine-containing translucent cured film according to any one of items 1 to 5, wherein the fluorine-free polymerizable compound is a fluorine-free (meth)acrylate compound. 7. The water-repellent, fluorine-containing translucent cured film according to any one of items 1 to 6, wherein the surfaces of the inorganic oxide fine particles are modified with (meth)acryloyl groups. 8. The water-repellent fluorine-containing translucent cured film according to any one of items 1 to 7, wherein the content of inorganic oxide fine particles is 1 to 200 parts by weight per 100 parts by weight of the total of all components of the curable composition excluding inorganic oxide fine particles. 9. Transmittance (L) in the transmittance measurement mode of the spectrophotometer (CM-5)* 9. The water-repellent fluorine-containing semitransparent cured film according to any one of items 1 to 8, wherein the water-repellent fluorine-containing semitransparent cured film has a water-repellent fluorine-containing semitransparent cured film having ... [Effects of the Invention]

[0013] The main object of the present invention is to provide a cured film that combines high water repellency and durability while also having relatively high transparency. In particular, the present invention provides a cured film having a specific uneven surface by combining a specific curable compound with specific inorganic oxide microparticles and curing them with active energy rays. This provides high water repellency and high abrasion resistance, thereby enabling the high water repellency to be maintained for a relatively long period of time. Furthermore, by limiting the size of the inorganic oxide microparticles to 200 nm or less, a cured film having relatively high transparency can be provided.

[0014] The cured film of the present invention having such characteristics can be widely applied to various materials or products whose surfaces should be imparted with water repellency. [Brief explanation of the drawings]

[0015] [Figure 1] FIG. 2 is a view showing the results of observing the cross section of the cured film obtained in Example 1 with a field emission scanning electron microscope. DETAILED DESCRIPTION OF THE INVENTION

[0016] 1.Water-repellent, fluorine-containing, semi-transparent cured film The water-repellent, fluorine-containing, translucent cured film of the present invention (cured film of the present invention) is characterized in that inorganic oxide fine particles with a particle size of 200 nm or less are contained in a cured film of a curable composition containing a fluorine-containing polymerizable compound and a fluorine-free polymerizable compound.

[0017] Details of the types and compositions of the components (fluorine-containing polymerizable compound, etc.) that constitute the cured film of the present invention will be explained later in "2. Method for producing cured film."

[0018] The cured film of the present invention is composed of a cured product of a curable composition containing a fluorine-containing polymerizable compound and a fluorine-free polymerizable compound, and has a structure in which inorganic oxide fine particles are dispersed in the matrix of the cured product.

[0019] In the cured film of the present invention, at least a portion of the inorganic oxide fine particles contributes to the formation of an uneven surface of the cured film, thereby imparting a specific uneven surface to the surface of the cured film of the present invention, thereby achieving excellent water repellency, durability, and good transparency.

[0020] From the viewpoint of water repellency, durability, and transparency, the uneven shape is determined by measuring the arithmetic mean roughness (R a ) is 0.05 μm or more and 1.00 μm or less (especially 0.10 μm or more and 0.80 μm or less), and the maximum height roughness (R z ) is 0.50 μm or more and 10.00 μm or less (especially 0.60 μm or more and 8.00 μm or less), and the average length of the element (R sm ) is preferably in the range of 50.0 μm or more and 1000.0 μm or less (particularly, 100.0 μm or more and 800.0 μm or less).

[0021] Furthermore, from the same viewpoint, the uneven shape is determined by observing the surface of the cured film using a white light interference microscope in accordance with ISO standard 25178, and is calculated as the arithmetic mean surface height (S a ) is 0.01 μm or more and 2.00 μm or less (especially 0.03 μm or more and 1.00 μm or less), and the root mean square height (S q ) is 0.05 μm or more and 3.00 μm or less (especially 0.06 μm or more and 1.50 μm or less), and the maximum cross-sectional height (S t ) is preferably in the range of 1.00 μm or more and 30.00 μm or less (particularly, 2.00 μm or more and 20.00 μm or less).

[0022] In order to form the above-mentioned cured film surface and to exhibit high transparency, inorganic oxide fine particles having a particle size of 200 nm or less (particularly 150 nm or less) may be used. As long as these conditions are met, nanoparticles having an average primary particle size of 1 to 100 nm (particularly 2 to 50 nm) may also be used.

[0023] The shape of the inorganic oxide particles is not limited as long as it can form minute irregularities on the surface, and any shape such as spherical, scaly, needle-like, or irregular may be used.

[0024] The content of inorganic oxide fine particles in the cured film of the present invention depends on the type of inorganic oxide fine particles used, but from the viewpoint of water repellency and durability, the content of inorganic oxide fine particles is generally set to 100% by weight of the inorganic oxide fine particles in the curable composition. and solvent The content may be about 1 to 200 parts by weight, preferably 5 to 150 parts by weight, and more preferably 10 to 100 parts by weight, per 100 parts by weight of the total of the components excluding the above. Therefore, the content of the inorganic oxide fine particles in the cured film of the present invention may be, for example, about 0.5 to 70% by weight (particularly about 4 to 60% by weight).

[0025] The cured film of the present invention may contain other additives within the range that does not impair the effects of the present invention. For example, additives such as colorants (dyes, pigments), antistatic agents, antioxidants, UV absorbers, dispersants, surfactants, leveling agents, surface conditioners, anti-sagging agents, thickeners, antifoaming agents, and lubricants may be contained. Note that, if any of these additives corresponds to inorganic oxide fine particles, they are included in the content of the inorganic oxide fine particles.

[0026] The cured film of the present invention is formed by curing a fluorine-containing polymerizable compound or the like as described above, and the fluorine concentration at the surface of the cured film measured by XPS analysis (X-ray photoelectron spectroscopy) as an indicator of the fluorine content is preferably 5 to 50 atomic % (particularly 10 to 40 atomic %). By having a water-repellent fluorine component present at least on the surface of the cured film within this range, excellent water repellency can be more reliably obtained.

[0027] The cured film of the present invention is not particularly limited in its transmittance as long as it is transparent or translucent. The transmittance is measured by a spectrophotometer (CM-5, Konica Minolta Japan Inc.) in the transmittance measurement mode (L * The transmittance is preferably 60 or more (particularly 65 or more). The upper limit of the transmittance can be set to, for example, 100, but is not limited to this.

[0028] The thickness of the cured film of the present invention can be appropriately set depending on, for example, the material of the substrate to which the cured film of the present invention is applied, the desired water repellency, transmittance, etc., and can be, for example, within the range of about 0.1 to 10 μm, but is not limited thereto.

[0029] 2. Manufacturing method for water-repellent fluorine-containing translucent cured film The cured film of the present invention can be suitably produced, for example, by a method including: (1) a step (coating film forming step) of forming a coating film from a fluorine-containing composition (the composition of the present invention) containing (a) inorganic oxide fine particles having a particle size of 200 nm or less, (b) a fluorine-containing polymerizable compound, and (c) a fluorine-free polymerizable compound; and (2) a step (curing step) of curing the coating film to obtain a cured film.

[0030] Each component constituting the composition of the present invention will be specifically described below. In the present invention, unless otherwise specified, acryloyl groups and methacryloyl groups will be collectively referred to as "(meth)acryloyl groups." Acrylates and methacrylates will be collectively referred to as "(meth)acrylates."

[0031] (1) Paint film formation process In the coating film formation process, a coating film is formed from a fluorine-containing composition (the composition of the present invention) containing (a) inorganic oxide fine particles having a particle size of 200 nm or less, (b) a fluorine-containing polymerizable compound, and (c) a fluorine-free polymerizable compound.

[0032] Inorganic oxide fine particles The inorganic oxide fine particles used have a particle size of 200 nm or less. By incorporating such inorganic oxide fine particles into the composition of the present invention, extremely fine irregularities can be formed on the surface of the coating film when the composition is formed into a coating film, which contributes to high water repellency.

[0033] The type of inorganic oxide is not particularly limited as long as the above-mentioned effects can be obtained, and examples thereof include inorganic oxides such as silicon oxide, titanium oxide, and aluminum oxide. These inorganic oxides can be used alone or in combination of two or more. As in the above specific examples, in the present invention, inorganic oxides also include metal oxides.

[0034] These inorganic oxide particles themselves can be known or commercially available. For example, silicon oxide products include those with the product names "AEROSIL 50," "AEROSIL 150," "AEROSIL 200," "AEROSIL 300," "AEROSIL 380," "AEROSIL R972," "AEROSIL R972V," "AEROSIL R972CF," "AEROSIL R974," "AEROSIL RX200," "AEROSIL RY200," "AEROSIL R202," "AEROSIL R805," "AEROSIL R812," and "AEROSIL R812S" (all manufactured by Nippon Aerosil Co., Ltd.), "YA010C," "YA050C," and "YC100C" (all manufactured by Admattex Co., Ltd.). Titanium oxide products include those with the product name "AEROXIDE TiO2T805" (manufactured by Nippon Aerosil Co., Ltd.). Examples of aluminum oxide include the product "AEROXIDE Alu C" (manufactured by Nippon Aerosil Co., Ltd.).

[0035] In particular, in the present invention, inorganic oxide fine particles preferably have functional groups on the surface of each particle. For example, polymerizable functional groups (curable functional groups) such as (meth)acryloyl groups, (meth)acryloyloxy groups, epoxy groups, allyl groups, and vinyl groups are preferred. This strengthens the bond between the inorganic oxide fine particles and the resin matrix in the cured film formed by active energy ray curing, resulting in a cured film with improved durability (particularly abrasion resistance). These functional groups can be imparted by surface-treating untreated inorganic oxide fine particles using a known method. For example, the fine particle surface can be surface-modified with a silane coupling agent having a reactive functional group, such as a (meth)acryloyl group. Alternatively, commercially available inorganic oxide fine particles with such functional groups can be used. Examples include products with the product names "AEROSIL R711" and "AEROSIL VP RM50L" (both manufactured by Nippon Aerosil Co., Ltd.).

[0036] As described above, inorganic oxide fine particles having a particle size of 200 nm or less may be used. For example, nanoparticles having an average primary particle size of 1 to 100 nm (particularly 2 to 50 nm) may also be used.

[0037] The composition of the present invention may contain a small amount of particles having a particle size exceeding 200 nm, as long as the effect of the present invention is not impaired. However, it is preferable to remove particles having a particle size exceeding 200 nm by classification or the like.

[0038] In the present invention, the average primary particle size can be measured using a field emission scanning electron microscope (FE-SEM), and if the resolution of the scanning electron microscope is low, it may be measured using another electron microscope such as a transmission electron microscope in combination. Specifically, if the particle shape is spherical, its diameter is considered to be the diameter, and if the particle shape is non-spherical, its longest diameter is considered to be the diameter, and the average value of the diameters of 300 particles randomly selected by observation using a scanning electron microscope or the like is taken to be the average primary particle size.

[0039] The content (solid content ratio) of inorganic oxide particles in the composition of the present invention is not limited, but can be appropriately set within the range of 1 to 200 parts by weight (particularly 5 to 150 parts by weight) per 100 parts by weight of the total of the components of the composition of the present invention excluding inorganic oxide particles and solvent (hereinafter also referred to as "polymerizable mixture"). Therefore, the content of inorganic oxide particles in the composition of the present invention can be, for example, about 1 to 60% by weight (particularly about 4 to 60% by weight).

[0040] The total of the components of the composition of the present invention excluding the inorganic oxide fine particles and the solvent usually refers to the total (solid content) of the fluorine-containing polymerizable compound, the fluorine-free polymerizable compound, and the photopolymerization initiator.

[0041] A preferred embodiment of the present invention involves the use of two or more inorganic oxide microparticles having different average primary particle diameters within the above particle size range. For example, a first microparticle may be used in combination with a second microparticle having a larger average primary particle diameter than the first microparticles. In this case, the average primary particle diameter of the first microparticles is preferably 1 nm to 20 nm, and more preferably 5 nm to 15 nm. The average primary particle diameter of the second microparticles is preferably 21 nm to 100 nm, and more preferably 25 nm to 50 nm. By using two types of microparticles with different sizes, a nanoscale uneven structure that contributes to water repellency and a microscale uneven structure (surface unevenness) that contributes to durability can be more reliably formed when a cured film is formed, thereby further improving water repellency and durability.

[0042] In this case, the content of the first microparticles is preferably 1 part by weight or more and 50 parts by weight or less, and more preferably 10 parts by weight or more and 40 parts by weight or less, relative to 100 parts by weight of the polymerizable mixture. The content of the second microparticles is preferably 1 part by weight or more and 100 parts by weight or less, and more preferably 10 parts by weight or more and 50 parts by weight or less, relative to 100 parts by weight of the polymerizable mixture. If the first microparticles and second microparticles are in these ranges, the water repellency and durability will be even better.

[0043] The materials of the first fine particles and the second fine particles are not particularly limited, and may be the same material or different materials.

[0044] Fluorine-containing polymerizable compounds The fluorine-containing polymerizable compound is a basic component for imparting water repellency to the cured film formed from the composition of the present invention.

[0045] The fluorine-containing polymerizable compound is not particularly limited as long as it has a fluorine-containing organic group and a polymerizable (curable) functional group (polymerizable double bond). The fluorine-containing polymerizable compound includes not only compounds used as monomers before polymerization, but also compounds with relatively large molecular weights, generally called oligomers or macromonomers.

[0046] Examples of the above-mentioned organic group containing fluorine include a) an organic group having a perfluoroalkyl structure, b) an organic group having a perfluoropolyether structure, c) an alkylene group in which some of the hydrogen atoms are substituted with fluorine atoms, etc. Among these, an organic group having a perfluoropolyether structure can be preferably used.

[0047] The perfluoropolyether structure has the repeating unit -[C n F 2n O]- (where n is an integer of 1 or more). These may be linear or branched. Therefore, for example, -CF2-, -CF(CF3)-, -CF2CF2-, -CF2CF2CF2-, -CF(CF3)CF2- -CF(CF3)CF2CF2- -CF(CF3)CF(CF3)CF2- These include, but are not limited to:

[0048] In addition, when the repeating unit is composed of two or more of the above repeating units, each -[C n F 2n O]-groups may be the same as or different from each other.

[0049] The polymerizable functional group bonded to the fluorine-containing organic group is not limited, but particularly preferably used are a (meth)acryloyl group, a (meth)acryloyloxy group, an epoxy group, an allyl group, a vinyl group, etc. The fluorine-containing polymerizable compound may have one or more polymerizable functional groups.

[0050] The polymerizable functional group may be bonded to either the end or the side chain of the fluorine-containing organic group.

[0051] Furthermore, the polymerizable functional group may be directly bonded to the fluorine-containing organic group or may be bonded via another organic group (such as a divalent organic group). Therefore, for example, the polymerizable functional group may be bonded to the fluorine-containing organic group via a urethane bond -COONH-, an ester bond -COO-, or the like. Therefore, for example, perfluoropolyether urethane (meth)acrylate, which has a structure in which a (meth)acryloyl group is bonded to a perfluoropolyether group via a urethane bond, can also be used as the fluorine-containing polymerizable compound.

[0052] The molecular weight of the fluorine-containing polymerizable compound may be, but is not limited to, a number average molecular weight of about 100 to 100,000, and therefore compounds having a number average molecular weight of about 500 to 20,000 can also be used.

[0053] Specific examples of fluorine-containing polymerizable compounds include at least one of perfluoroalkyl (meth)acrylate, perfluoroalkyl vinyl ether, perfluoropolyether (meth)acrylate (particularly perfluoropolyether urethane (meth)acrylate), 1H,1H,2H,2H-tridecafluorooctyl acrylate, etc. Among these, perfluoropolyether (meth)acrylate (particularly perfluoropolyether urethane (meth)acrylate) and the like can be preferably used. These compounds have a highly reactive (meth)acryloyl group and a perfluoropolyether group that is excellent in water and oil repellency, droplet removal properties, etc., so that it is possible to more reliably form a cured film with higher water repellency. These compounds can be used alone or in combination.

[0054] In the present invention, the fluorine-containing polymerizable compound itself can be a known or commercially available one. For example, the perfluoropolyether urethane (meth)acrylate is available under the product names "Fluorolink AD1700" and "Fluorolink MD700" (both manufactured by Solvay Specialty Polymers Japan Ltd.), and the 1H,1H,2H,2H-tridecafluorooctyl acrylate is available under the product name "Viscoat 13F" (manufactured by Osaka Organic Chemical Industry Ltd.).

[0055] The content of the fluorine-containing polymerizable compound is not limited, but is usually preferably 5 to 95 parts by weight, and more preferably 30 to 60 parts by weight, per 100 parts by weight of the polymerizable mixture. If the content of the fluorine-containing polymerizable compound is 5 parts by weight or more, the water repellency of the cured film will be higher, and if it is 95 parts by weight or less, a polymerization initiator and the like can be appropriately added, making it easier to cure more reliably.

[0056] Fluorine-free polymerizable compounds The fluorine-free polymerizable compound is a polymerizable compound that does not contain fluorine, and has the effect of more reliably reducing the viscosity of the composition of the present invention when a perfluoropolyether acrylate or the like having a relatively high viscosity is used.

[0057] The type of fluorine-free polymerizable compound is not particularly limited as long as it has one or more polymerizable functional groups (curable functional groups) such as (meth)acryloyl groups, (meth)acryloyloxy groups, epoxy groups, allyl groups, vinyl groups, etc., and does not contain fluorine. The type can be changed depending on the additional performance required for the application, such as adhesion to the substrate, chemical resistance, flexibility, weather resistance, etc. Examples include 1,6-hexanediol diacrylate (HDDA), tetrahydrofurfuryl acrylate (THFA), and amine (meth)acrylate. These compounds can be used alone or in combination.

[0058] The content of the fluorine-free polymerizable compound is not limited, but is preferably set to 5 to 90 parts by weight in 100 parts by weight of the polymerizable mixture.

[0059] In addition, in the composition of the present invention, the amine (meth)acrylate plays a role in effectively suppressing inhibition of curing on the surface. From this point of view, the amine (meth)acrylate is preferably contained in an amount of 0.1 to 5 parts by weight per 100 parts by weight of the polymerizable mixture.

[0060] Other additives In the composition of the present invention, particularly when ultraviolet light is used as the active energy ray, a photopolymerization initiator can also be used. The photopolymerization initiator is not particularly limited as long as it can cause polymerization upon ultraviolet light irradiation. Therefore, any type of photopolymerization initiator, such as a cleavage-type polymerization initiator or a hydrogen abstraction-type polymerization initiator, can be used. For example, intramolecular cleavage-type initiators include alkylphenones and oxime esters. For example, hydrogen abstraction-type initiators include benzophenone / amines and thioxanthone / amines. These can be used alone or in combination of two or more. These photopolymerization initiators themselves can be known or commercially available. For example, the product name "Omnirad127" (manufactured by IGM Resins BV) can be mentioned.

[0061] The content of the photopolymerization initiator is not particularly limited, but can usually be about 0.1 to 10 parts by weight per 100 parts by weight of the total of the fluorine-containing polymerizable compound and the fluorine-free polymerizable compound.

[0062] In the composition of the present invention, a solvent can be used as needed for the purpose of adjusting viscosity, etc. The solvent is not particularly limited, and examples thereof include organic solvents such as aromatic hydrocarbons such as toluene and xylene, alicyclic hydrocarbon solvents such as methylcyclohexane and cyclohexane, ester solvents such as ethyl acetate and butyl acetate, ketone solvents such as methyl ethyl ketone and acetone, and alcohol solvents such as isopropyl alcohol and denatured ethanol. These can be used alone or in combination of two or more.

[0063] The amount of solvent used, when used, is not particularly limited, but can be adjusted appropriately to obtain an appropriate viscosity depending on the coating / painting method, etc., within the range of approximately 10 to 500 parts by weight per 100 parts by weight of the total amount of inorganic oxide microparticles and polymerizable mixture, but is not limited to this.

[0064] The composition of the present invention may contain additives such as colorants (dyes, pigments), antistatic agents, antioxidants, UV absorbers, dispersants, surfactants, leveling agents, surface conditioners, anti-sagging agents, thickeners, antifoaming agents, lubricants, etc., within the range that does not impair the effects of the present invention. When any of these additives also falls under the category of inorganic oxide fine particles, they are included in the content of the inorganic oxide fine particles.

[0065] The composition of the present invention can be prepared by mixing these components uniformly, using a known or commercially available kneader, mixer, or the like.

[0066] In the coating film forming step, a coating film is formed using the composition of the present invention as described above. Usually, a coating film of the composition of the present invention may be formed on a substrate.

[0067] The substrate used in the coating film formation process may be a material to be imparted with water repellency, or a cured film formed on that material or on a portion thereof. Here, water repellency includes not only the ability to repel water, but also the ability to repel ice, ice water, etc. Therefore, the composition of the present invention can be used to prevent adhesion of water or the accumulation of ice, snow, etc.

[0068] The material of the substrate is not particularly limited, and may be, for example, any of synthetic resin, rubber, metal, ceramic, fibrous material (paper, nonwoven fabric, woven fabric, etc.), composite materials thereof, etc. Furthermore, the substrate may be any of a finished product (finished product), a semi-finished product, or the raw material thereof. More specifically, the substrate may be widely applied to such products as packaging materials, daily necessities, building materials, clothing, cosmetics, pharmaceuticals, etc. Furthermore, the substrate may be applied to products (building materials, automobile parts, etc.) used outdoors for waterproofing, preventing ice and snow adhesion, etc., or materials therefor.

[0069] The formation of a coating film can be carried out, for example, by applying the liquid composition of the present invention onto a substrate. The application method is not particularly limited, and can be carried out, for example, by a doctor blade, a bar coater, a brush, a roller, a spray gun, etc. Furthermore, in the present invention, when applying, the above-mentioned application and drying can be repeated two or more times to obtain a predetermined thickness.

[0070] The thickness of the coating film can be appropriately set depending on, for example, the use of the cured film, and can be adjusted so that the thickness of the cured film is, for example, about 0.1 to 10 μm, but is not limited to this.

[0071] After the coating film is formed, it is preferable to perform a heat treatment for drying as needed. The degree of heat treatment varies depending on the amount of coating in the previous step and the amount of solvent contained in the composition, but whether the solvent has completely evaporated can be determined by visual inspection, odor, etc. If the heat treatment is insufficient, there is a risk of poor curing of the coating film in the subsequent curing step. When heat treatment is performed, it may be performed at, for example, about 50 to 160°C, but is not limited thereto.

[0072] (2) Paint film curing process In the coating film curing step, the coating film formed above is cured to obtain a cured film.

[0073] The curing method is not particularly limited as long as it can cure the composition of the present invention by polymerizing it, and examples thereof include curing with active energy rays, heat curing, etc. In the present invention, curing with active energy rays is particularly preferred.

[0074] The active energy rays used in the curing step are not limited, and examples thereof include electron beams, ultraviolet rays, far ultraviolet rays, visible light, infrared rays, etc. These can be irradiated using known or commercially available active energy ray irradiation devices.

[0075] The irradiation conditions can also be set within the range normally adopted. For example, when ultraviolet rays are used as the active energy rays, the ultraviolet irradiation conditions are as follows: a peak irradiance of 10 to 1000 mW / cm 2 The cumulative light intensity is 100-3000mJ / cm 2 However, this is only when an ultraviolet integrating illuminometer with a 365 nm wavelength receiver is used.

[0076] Furthermore, for example, when an electron beam is used as the active energy beam, the electron beam irradiation conditions can be an acceleration voltage of 100 to 300 kV and a dose of about 10 to 100 kGy. [Example]

[0077] The features of the present invention will be described in more detail below with reference to examples and comparative examples. However, the scope of the present invention is not limited to these examples. In the examples, "%" indicates "% by weight" unless otherwise specified.

[0078] Example 1 A polymerizable mixture was prepared by mixing 50 parts by weight of Fluorolink AD1700 (perfluoropolyether acrylate, 70% solids by weight, Solvay Specialty Polymers Japan), 15 parts by weight of Viscoat #230 (1,6-hexanediol diacrylate, Osaka Organic Chemical Industry Ltd.), 50 parts by weight of Viscoat #150 (tetrahydrofurfuryl acrylate, Osaka Organic Chemical Industry Ltd.), 4 parts by weight of Omnirad 127 (cleavage-type polymerization initiator, IGM Resins BV), 1 part by weight of CN371NS (amine acrylate, SARTOMER), and 1 part by weight of benzophenone (photopolymerization initiator, Fujifilm Wako Pure Chemical Industries). To 100 parts by weight of the obtained polymerizable mixture, 10 parts by weight of R711 (methacrylic group surface-modified silica microparticles (average primary particle diameter: 12 nm), AEROSIL), 10 parts by weight of VP RM50L (methacrylic group surface-modified silica microparticles (average primary particle diameter: 40 nm), AEROSIL), and 100 parts by weight of ethyl acetate (Fujifilm Wako Pure Chemical Industries) were added and mixed to obtain a mixed solution. The resulting mixture was applied to a double-sided adhesive PET film (Toyobo Co., Ltd., Cosmoshine, 100 μm thick) using a No. 8 bar coater. After application, the film was dried at 100°C for 3 minutes to form a coating film on the double-sided adhesive PET film. The coating film was then irradiated with ultraviolet light using a high-pressure mercury UV lamp to produce a cured film approximately 1 μm thick. The UV irradiation conditions were as follows: the coated film was placed on a conveyor and passed under a UV lamp once. The UV irradiance was 200-300 mW / cm peak irradiance. 2 The cumulative amount of light irradiated was 650-800mJ / cm 2 The peak irradiance and the integrated light amount were measured using an Eye ultraviolet integrated illuminance meter (product name: "UVPF-A1" (equipped with a 365 nm photodetector PD-365), manufactured by Iwasaki Electric Co., Ltd.).

[0079] Example 2 A mixed solution was obtained by adding and mixing R711 (20 parts by weight), VP RM50L (20 parts by weight), and ethyl acetate (300 parts by weight) to 100 parts by weight of the polymerizable mixture prepared in the same manner as in Example 1. The mixed solution obtained was coated, dried, and cured in the same manner as in Example 1 to obtain a cured film.

[0080] Example 3 A mixed solution was obtained by adding R711 (10 parts by weight) and ethyl acetate (100 parts by weight) to and mixing with 100 parts by weight of the polymerizable mixture prepared in the same manner as in Example 1. The mixed solution obtained was coated, dried, and cured in the same manner as in Example 1 to obtain a cured film.

[0081] Example 4 A mixed solution was obtained by adding R711 (20 parts by weight) and ethyl acetate (150 parts by weight) to and mixing with 100 parts by weight of the polymerizable mixture prepared in the same manner as in Example 1. The mixed solution obtained was coated, dried, and cured in the same manner as in Example 1 to obtain a cured film.

[0082] Example 5 A mixed solution was obtained by adding R711 (40 parts by weight) and ethyl acetate (300 parts by weight) to and mixing with 100 parts by weight of the polymerizable mixture prepared in the same manner as in Example 1. The mixed solution obtained was coated, dried, and cured in the same manner as in Example 1 to obtain a cured film.

[0083] Example 6 A mixed solution was obtained by adding VP RM50L (20 parts by weight) and ethyl acetate (100 parts by weight) to and mixing with 100 parts by weight of the polymerizable mixture prepared in the same manner as in Example 1. The mixed solution obtained was coated, dried, and cured in the same manner as in Example 1 to obtain a cured film.

[0084] Example 7 A mixed solution was obtained by adding VP RM50L (40 parts by weight) and ethyl acetate (166 parts by weight) to and mixing with 100 parts by weight of the polymerizable mixture prepared in the same manner as in Example 1. The mixed solution obtained was coated, dried, and cured in the same manner as in Example 1 to obtain a cured film.

[0085] Example 8 A polymerizable mixture was prepared by mixing AD1700 (10 parts by weight), Viscoat #230 (24.2 parts by weight), Viscoat #150 (80.8 parts by weight), Omnirad 127 (4 parts by weight), CN371NS (1 part by weight), and benzophenone (1 part by weight). At this time, the proportion of the fluorine-containing polymerizable compound in the polymerizable mixture was 5.9%. To 100 parts by weight of the obtained polymerizable mixture, R711 (5 parts by weight), VP RM50L (5 parts by weight), and ethyl acetate (75 parts by weight) were added and mixed to obtain a mixed solution. The obtained mixed solution was coated, dried, and cured in the same manner as in Example 1 to obtain a cured film.

[0086] Example 9 A mixed solution was obtained by adding and mixing R711 (10 parts by weight), VP RM50L (10 parts by weight), and ethyl acetate (100 parts by weight) to 100 parts by weight of the polymerizable mixture prepared in the same manner as in Example 8. The mixed solution obtained was coated, dried, and cured in the same manner as in Example 1 to obtain a cured film.

[0087] Example 10 To 100 parts by weight of the polymerizable mixture prepared in the same manner as in Example 8, R711 (20 parts by weight), VP RM50L (20 parts by weight), and ethyl acetate (300 parts by weight or more) were added and mixed to obtain a mixed solution. The mixed solution obtained was coated, dried, and cured in the same manner as in Example 1 to obtain a cured film.

[0088] Example 11 A mixed solution was obtained by adding R711 (10 parts by weight) and ethyl acetate (100 parts by weight) to and mixing with 100 parts by weight of the polymerizable mixture prepared in the same manner as in Example 8. The mixed solution obtained was coated, dried, and cured in the same manner as in Example 1 to obtain a cured film.

[0089] Example 12 A mixed solution was obtained by adding and mixing R711 (20 parts by weight) and ethyl acetate (150 parts by weight) to 100 parts by weight of the polymerizable mixture prepared in the same manner as in Example 8. The mixed solution obtained was coated, dried, and cured in the same manner as in Example 1 to obtain a cured film.

[0090] Example 13 A mixed solution was obtained by adding VP RM50L (20 parts by weight) and ethyl acetate (100 parts by weight) to and mixing with 100 parts by weight of the polymerizable mixture prepared in the same manner as in Example 8. The mixed solution obtained was coated, dried, and cured in the same manner as in Example 1 to obtain a cured film.

[0091] Example 14 A mixed solution was obtained by adding VP RM50L (40 parts by weight) and ethyl acetate (166 parts by weight) to and mixing with 100 parts by weight of the polymerizable mixture prepared in the same manner as in Example 8. The mixed solution obtained was coated, dried, and cured in the same manner as in Example 1 to obtain a cured film.

[0092] Example 15 A polymerizable mixture was prepared by mixing AD1700 (115 parts by weight), Omnirad127 (4 parts by weight), CN371NS (1 part by weight) and benzophenone (1 part by weight). To 100 parts by weight of the obtained polymerizable mixture, R711 (10 parts by weight), VP RM50L (10 parts by weight), and ethyl acetate (125 parts by weight) were added and mixed to obtain a mixed solution. The obtained mixed solution was coated, dried, and cured in the same manner as in Example 1 to obtain a cured film.

[0093] Example 16 A mixed solution was obtained by adding and mixing R711 (20 parts by weight) and ethyl acetate (150 parts by weight) to 100 parts by weight of the polymerizable mixture prepared in the same manner as in Example 15. The mixed solution obtained was coated, dried, and cured in the same manner as in Example 1 to obtain a cured film.

[0094] Example 17 A polymerizable mixture was prepared by mixing Fluorolink AD1700 (50 parts by weight), Viscoat #230 (15 parts by weight), Viscoat #150 (50 parts by weight), and CN371NS (amine acrylate, SARTOMER) (1 part by weight). At this time, the proportion of fluorine-containing polymerizable compounds in the polymerizable mixture was 34.7%. The polymerizable mixture of Example 17 was prepared by replacing the polymerizable mixture of Example 1 with the polymerizable mixture of Example 1 but without the polymerization initiator. The polymerizable mixture of Example 17 is cured by electron beam, so no initiator is required. To 100 parts by weight of the resulting mixture, R711 (10 parts by weight), VP RM50L (10 parts by weight), and ethyl acetate (125 parts by weight) were added and mixed to obtain a mixed liquid. The resulting mixture was applied to a double-sided, easily adhesive PET (polyethylene terephthalate) film using a No. 8 bar coater. After application, the film was dried at 100°C for 3 minutes to form a coating. The coating was then irradiated with electron beams using an electron beam irradiator (CB250, i-Electron Beam Co., Ltd.) to produce a cured film. The electron beam irradiation conditions were an acceleration voltage of 200 kV, an absorbed dose of 30 kGy, and a single irradiation.

[0095] [Table 1]

[0096] Comparative Example 1 A 9 wt% solution of amorphous fluororesin (product name "CYTOP", CTX-809A, manufactured by Asahi Glass Co., Ltd.) was diluted using CT-solve 180 to obtain a 1.0 wt% CYTOP solution. TFW3000F, TFW1000, and TFW500 (polytetrafluoroethylene (PTFE) powders with average primary particle diameters of 3 μm, 10 μm, and 25 μm, respectively, manufactured by Seishin Co., Ltd.) were mixed in a 1:1:1 (weight ratio) ratio to obtain a PTFE mixed powder. The PTFE mixed powder was added to the 1.0 wt% CYTOP solution and stirred to obtain a 6.0 wt% PTFE coating solution. The resulting coating solution was applied to a double-sided adhesive PET film using a No. 24 bar coater and then heat-cured at 100°C for 1 hour, followed by 150°C for 3 hours. It was thought that it would be better to use a No. 8 bar coater (liquid film thickness 18 μm) as in the examples, but the PTFE mixed powder in the coating solution was coarse, and the No. 8 bar coater was unable to form a coating film containing the PTFE powder uniformly, so a No. 24 bar coater was used.

[0097] Comparative Example 2 A coating solution and a PTFE mixed powder were prepared in the same manner as in Comparative Example 1. The coating solution was applied to a double-sided adhesive PET film using a No. 24 bar coater, and then a 0.04 m 2 7g of PTFE mixed powder was sprinkled evenly on the coated surface (20cm x 20cm). That is, 175g / m 2 The PTFE mixed powder was sprinkled on the laminate so that the laminate amount was 100°C for 1 hour, and then the laminate was heat-cured at 150°C for 3 hours.

[0098] Test Example 1 The treated surface (cured film) of each sample was used as the test surface, and the contact angle of 2.0 μL of pure water was measured using a contact angle measuring device ("DMs-401," manufactured by Kyowa Interface Science Co., Ltd.). A double paper wiper (Kimwipe S-200 mini, manufactured by Nippon Paper Crecia Co., Ltd.) was attached to the bottom of a 50 g weight with a 4 cm square base. The weight was placed on the test surface and pulled in one direction parallel to the test surface at approximately 20 cm / sec. The contact angle was measured after each pulling and rubbing. The measurement temperature can be room temperature (e.g., 20°C). Furthermore, in Comparative Example 2, significant PTFE mixed powder detachment occurred after the first friction, and it was determined that the paper wiper surface was not in an appropriate friction state for the second friction, so the paper wiper was replaced for the second friction. Although no particle detachment was observed in the Example, the paper wiper was replaced after the first friction in order to match the conditions of the Example and the Comparative Example. Since no particle detachment was observed after the second or subsequent friction, the paper wiper was not replaced. The number of frictions and the contact angle (unit: degrees) at that time are shown in Tables 2 and 3.

[0099] [Table 2]

[0100] [Table 3]

[0101] The results in Table 3 show that Comparative Example 1 did not achieve high water repellency. Comparative Example 2 achieved high water repellency before rubbing, but with rubbing, the PTFE mixed powder was significantly detached, and after two rubbings, the contact angle significantly decreased. On the other hand, in the Examples shown in Table 2, after three rubbings, most Examples showed very high water repellency with a contact angle of 140 degrees or more, and even after 10 rubbings, all Examples showed high water repellency with a contact angle of 135 degrees or more. As is clear from this, each Example can exhibit higher durability than Comparative Example 2. As described above, it can be seen that the present invention can achieve a surface that has both high durability and high water repellency.

[0102] Test Example 2 According to the ASME2009 standard, the arithmetic mean roughness (R a ), maximum height roughness (R z ) and the average length of the elements (R sm The measurement was carried out three times, and the average value was used as the measured value. The measurement conditions were a cutoff value (λ c The measurement results are shown in Table 4.

[0103] [Table 4]

[0104] Test Example 3 The cured film surface was observed using a white light interference microscope (VS1330, Hitachi High-Tech Corporation) in accordance with ISO standard 25178, and the arithmetic mean surface height (S a ), root mean square height (S q ) and maximum cross-sectional height (S t) was measured. The measurement conditions were: camera: high pixel count, camera speed: standard, objective lens: 10XDI, lens barrel: 1X, zoom lens: 1X, light source: 530 white, measurement device: piezo, measurement mode: wave, field of view size: 1024 x 1024, scan range: start: 10, stop: -85, number of effective pixels: 50%, average count: 1, lamp: auto, aperture stop: 100%, surface correction: primary, interpolation: full interpolation, filter: 3 x 3 pixels (boundary processing: object expansion and edge interpolation). Measurements were performed three times, and the average was used as the measured value. The measurement results are shown in Table 5.

[0105] [Table 5]

[0106] Test Example 4 The fluorine concentration on the surface of the cured films of Examples 12, 16, and 17 was measured by XPS analysis (X-ray photoelectron spectroscopy). The measurement conditions were: apparatus: Quantera SXM (PHI Corporation); excitation X-ray: monochromatic Al Kα 1,2 The X-ray diameter was 200 μm, the photoelectron detection angle was 45° (the detector tilt relative to the sample surface), the analysis software was MultiPak Version 9.5.0.8 (Ulvac-Phi), the smoothing was 9-point smoothing, and the horizontal axis correction was set to 284.6 eV for the C1s main peak (CHx, CC). The results are shown in Table 6.

[0107] [Table 6]

[0108] Test Example 5 The transmittance of each sample was measured. The transmittance was measured in the transmittance measurement mode using a spectrophotometer (CM-5, Konica Minolta Japan Inc.). *The measurement conditions were a viewing angle of 10°, a light source of D65, and a double-sided easy-adhesion PET film as a blank, and the average value of three measurements was taken as the measured value. The measurement results are shown in Table 7.

[0109] [Table 7]

[0110] Test Example 6 The cross section of the cured film obtained in Example 1 was observed with a field emission scanning electron microscope, and the observation results are shown in FIG. As shown in Figure 1, the inorganic oxide particles filling the inside of the cured film form micro-scale surface irregularities, and nano-scale surface irregularities are further formed on top of these.

Claims

1. a curable composition comprising a perfluoropolyether (meth)acrylate as a fluorine-containing polymerizable compound and a fluorine-free (meth)acrylate compound as a fluorine-free polymerizable compound, wherein a cured film of the curable composition contains 1 to 200 parts by weight of silicon oxide microparticles having a particle size of 200 nm or less and whose surfaces are modified with (meth)acryloyl groups, per 100 parts by weight of the total of all components of the curable composition excluding the silicon oxide microparticles and the solvent; A water-repellent, fluorine-containing, translucent cured film having an arithmetic mean roughness (Ra) of 0.10 μm or more and 0.80 μm or less, as determined by surface measurement of the cured film using a surface roughness measuring device, and a contact angle with water of 139.3 degrees or more after 0 friction cycles.

2. 2. The water-repellent, fluorine-containing, translucent cured film according to claim 1, wherein the arithmetic mean roughness (Ra) determined by measuring the surface of the cured film with a surface roughness measuring device is 0.10 μm or more and 0.80 μm or less, the maximum height roughness (Rz) is 0.50 μm or more and 10.00 μm or less, and the mean element length (Rsm) is 50.0 μm or more and 1000.0 μm or less.

3. 3. The water-repellent fluorine-containing translucent cured film according to claim 1 or 2, wherein the arithmetic mean surface height (Sa) within a square plane measuring 555.8 μm × 555.8 μm squares, as determined by observation of the surface of the cured film with a white light interference microscope, is from 0.01 μm to 2.00 μm, the root mean square height (Sq) is from 0.05 μm to 3.00 μm, and the maximum cross-sectional height (St) is from 1.00 μm to 30.00 μm.

4. 4. The water-repellent, fluorine-containing, semi-transparent cured film according to claim 1, wherein the fluorine concentration at the surface of the cured film as determined by XPS analysis is 5 to 50 atomic %.

5. A water-repellent, fluorine-containing, translucent cured film described in any one of claims 1 to 4, which contains 1,6-hexanediol diacrylate (HDDA), tetrahydrofurfuryl acrylate (THFA), and amine (meth)acrylate as non-fluorine-containing polymerizable compounds.

6. A water-repellent, fluorine-containing, translucent cured film described in any one of claims 1 to 4, having a thickness of 0.1 to 10 μm.

7. 7. The water-repellent, fluorine-containing, translucent cured film according to claim 1, which has a transmittance (L* value) of 60 or more in a transmittance measurement mode of a spectrophotometer.

Images