JP2014052394A - Resin film and production method of resin film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a novel and improved resin film and a production method of the resin film by which contamination resistance and sliding property can be improved as well as film strength can be improved.SOLUTION: The resin film includes: a low refractive index layer containing a plurality of hollow silica particles 20 and a binder resin 30 bonding the hollow silica particles; and a photopolymerizable fluorine polymer 41 and a thermally polymerizable fluorine polymer 42 which are bonded to the hollow silica particles 20 distributed on the surface of the low refractive index layer and are repulsive to the binder resin. The content percentage of the hollow silica particles 20 is 30 mass% or more and 60 mass% or less; the content percentage of the photopolymerizable fluorine polymer 41 and the thermally polymerizable fluorine polymer 42 is larger than 1 mass% and 7 mass% or less; the content percentage of the thermally polymerizable fluorine polymer 42 is 2 mass% or less; and a ratio of the content percentage of the thermally polymerizable fluorine polymer to the content percentage of the photopolymerizable fluorine polymer is 0.1 or more and 0.7 or less.

Description

  The present invention relates to a resin film and a method for producing the resin film.

  In many cases, an antireflection film is attached to the surface of a liquid crystal display or a plasma display. The antireflection film improves the visibility of the display by preventing the reflection of light on the display surface. The conventional antireflection film includes a low refractive index layer having a low refractive index and a high refractive index layer having a higher refractive index than the low refractive index layer. The low refractive index layer includes hollow silica particles, an acrylic resin, a fluorinated acrylic resin, and an additive.

  The hollow silica particles are silica particles having a hollow structure and have a role of reducing the refractive index of the low refractive index layer. The hollow silica particles have a hydroxyl group and a photopolymerizable functional group. Here, acryloyl group and methacryloyl group are known as photopolymerizable functional groups. The photopolymerizable functional group is also referred to as an ionizing radiation curable group.

  The acrylic resin has a role of a binder for bonding the hollow silica particles. The fluorinated acrylic resin has a role of reducing the refractive index of the low refractive index layer while bonding the hollow silica particles together. The additive imparts antifouling properties and slipperiness to the low refractive index layer, that is, the antireflection film, by binding to the functional groups of the hollow silica particles distributed on the surface of the low refractive index layer. Silicone and fluoropolymers are known as additives.

JP 2007-11323 A JP 2005-99778 A JP 2006-291077 A

  By the way, when the additive is present on the surface of the low refractive index layer, its function is exhibited. However, in the conventional low refractive index layer, the additive is distributed not only on the surface but also inside. The reason why the additive is distributed inside the low refractive index layer is that the hollow silica particles and the fluorinated acrylic resin inhibit the additive bleed out (transfer to the surface). That is, the additive cannot effectively move to the surface because the hollow silica particles serve as a barrier. In addition, the additive is compatible with the fluorinated acrylic resin. For example, since the fluoropolymer and the fluorinated acrylic resin both contain fluorine, they are easily compatible. That is, the additive remains in the vicinity of the fluorinated acrylic resin.

  Therefore, the conventional low refractive index layer cannot effectively distribute the additive on the surface of the low refractive index layer. For this reason, the conventional low refractive index layer has good initial antifouling properties and slipperiness to some extent, but there has been a problem that these characteristics are remarkably lowered by repeated surface wiping.

  In addition, in the conventional low refractive index layer, the additive distributed inside the low refractive index layer reduces the crosslink density of the binder resin (that is, acrylic resin and fluorinated acrylic resin), so that the film strength also decreases. There was also a problem. Specifically, the additive (particularly fluoropolymer) repels acrylic resin. For this reason, the acrylic resin is less likely to be distributed around the additive, and as a result, the crosslink density of the acrylic resin is lowered.

  On the other hand, although patent documents 1-3 disclose the technique regarding an antireflection film, the said problem was not able to be solved at all. That is, Patent Document 1 discloses a polymerizable composition containing hollow silica particles having an acryloyl group and / or a methacryloyl group on the surface, and an acrylic monomer having an acryloyl group and / or a methacryloyl group. Patent Document 2 discloses an antireflection laminate including an ionizing radiation curable resin composition and hollow silica particles in which at least a part of the particle surface is treated with a silane coupling agent having an ionizing radiation curable group. Patent Document 3 discloses a composition for forming a low refractive index film comprising a perfluoro group-containing (meth) acrylic ester resin and hollow silica particles treated with a silane coupling agent having a predetermined structure. However, any of these techniques is a technique aiming to firmly bond the hollow silica particles to each other, and thus cannot solve the above problems at all.

  Therefore, the present invention has been made in view of the above problems, and the object of the present invention is to improve the antifouling property and slipperiness, and improve the film strength. An object of the present invention is to provide an improved resin film and a method for producing the resin film.

  In order to solve the above problems, according to an aspect of the present invention, a low refractive index layer including a plurality of hollow silica particles and a binder resin that bonds the hollow silica particles to each other, and distributed on the surface of the low refractive index layer A photopolymerizable fluoropolymer and a thermopolymerizable fluoropolymer that bind to the hollow silica particles and repel the binder resin, and the content of the hollow silica particles is 30% by mass or more and 60% by mass or less. The total content of the polymerizable fluoropolymer and the thermally polymerizable fluoropolymer is greater than 1% by mass and 7% by mass or less, and the content of the thermally polymerizable fluoropolymer is 2% by mass or less. A resin film is provided in which the ratio of the content ratio to the content ratio of the photopolymerizable fluoropolymer is 0.1 or more and 0.7 or less.

  According to this aspect, the resin film includes a photopolymerizable fluoropolymer and a thermopolymerizable fluoropolymer that bind to the hollow silica particles distributed on the surface of the low refractive index layer and repel the binder resin. Therefore, since the photopolymerizable fluoropolymer and the thermopolymerizable fluoropolymer are effectively bleed out due to the repulsive force of the binder resin, the resin film is formed on the surface of the low refractive index layer. Can be unevenly distributed. Thereby, the resin film can improve antifouling property and slipperiness, and can improve film strength.

  Here, the binder resin may have a hydrogen bond forming group capable of forming a hydrogen bond with another functional group.

  According to this aspect, since the binder resin has a hydrogen bond forming group, the photopolymerizable fluoropolymer and the thermopolymerizable fluoropolymer can be effectively bleed out.

  The binder resin may have a hydroxyl group as a hydrogen bond forming group.

  According to this viewpoint, since the binder resin has a hydroxyl group as a hydrogen bond forming group, the photopolymerizable fluoropolymer and the thermopolymerizable fluoropolymer can be effectively bleed out.

  Further, the weight average molecular weight of the thermally polymerizable fluoropolymer may be larger than the weight average molecular weight of the photopolymerizable fluoropolymer.

  According to this viewpoint, the photopolymerizable fluoropolymer and the thermopolymerizable fluoropolymer can effectively bleed out. Further, since the photopolymerizable fluoropolymer functions as a compatibilizing agent, the solubility of the thermopolymerizable fluoropolymer in the solvent is improved.

  Further, the weight average molecular weight of the thermally polymerizable fluoropolymer may be 10,000 or more, and the weight average molecular weight of the photopolymerizable fluoropolymer may be less than 10,000.

  According to this viewpoint, the photopolymerizable fluoropolymer and the thermopolymerizable fluoropolymer can effectively bleed out. Further, since the photopolymerizable fluoropolymer functions as a compatibilizing agent, the solubility of the thermopolymerizable fluoropolymer in the solvent is improved.

  According to another aspect of the present invention, hollow silica particles, a binder monomer capable of binding the hollow silica particles, and a photopolymerizable fluoropolymer capable of binding to the hollow silica particles and repelling the binder monomer. And a step of generating a coating solution containing the thermally polymerizable fluoropolymer, a step of applying the coating solution to the substrate, and a step of initiating a polymerization reaction, and the content of the hollow silica particles is 30% by mass or more The total content of the photopolymerizable fluoropolymer and the thermopolymerizable fluoropolymer is greater than 1% by mass and 7% by mass or less, and the content of the thermopolymerizable fluoropolymer is 2% by mass or less. The ratio of the content of the heat-polymerizable fluoropolymer to the content of the photopolymerizable fluoropolymer is 0.1 or more and 0.7 or less, and the production of the resin film The law is provided.

  According to this viewpoint, the resin film can be formed simply by applying a coating solution in which each material is dissolved to the substrate and starting the polymerization reaction. Therefore, a resin film excellent in antifouling property, slipperiness and film strength can be easily produced.

  As described above, according to the present invention, the resin film can improve the antifouling property and the slipperiness, and can improve the film strength.

It is a sectional side view showing typically the composition of the resin film concerning the embodiment of the present invention.

  Exemplary embodiments of the present invention will be described below in detail with reference to the accompanying drawings. In addition, in this specification and drawing, about the component which has the substantially same function structure, duplication description is abbreviate | omitted by attaching | subjecting the same code | symbol.

<1. Configuration of resin film>
First, based on FIG. 1, the structure of the resin film 10 which concerns on this embodiment is demonstrated. The resin film 10 includes a low refractive index layer 10 a and an additive 40. The low refractive index layer 10a includes hollow silica particles 20, a binder resin 30, and a photoinitiator. The resin film 10 of the present embodiment is used for, for example, an antireflection film, but is suitably applied to other fields, for example, a field using a low refractive index film.

  The hollow silica particles 20 are nanoscale particles dispersed in the low refractive index layer 10a and having a thermally polymerizable functional group and a photopolymerizable functional group. Specifically, the hollow silica particle 20 has an outer shell layer, and the inside of the outer shell layer is hollow or porous. The outer shell layer and the porous body are mainly composed of silicon oxide. In addition, many thermopolymerizable functional groups and photopolymerizable functional groups are bonded to the outer shell layer. The thermopolymerizable functional group, the photopolymerizable functional group, and the outer shell layer are bonded via at least one of a Si—O—Si bond and a hydrogen bond. Examples of the thermally polymerizable functional group include a hydroxyl group, a silanol group, an alkoxy group, a halogen, hydrogen, and an isocyanate group. Examples of the photopolymerizable functional group include an acryloyl group and a methacryloyl group. That is, the hollow silica particle 20 includes at least one of an acryloyl group and a methacryloyl group as a photopolymerizable functional group. The photopolymerizable functional group is also referred to as an ionizing radiation curable group. The hollow silica particles 20 need only have a thermally polymerizable functional group and a photopolymerizable functional group, and the number and type of these functional groups are not particularly limited.

  The average particle diameter of the hollow silica particles 20 is not particularly limited, but is preferably 10 to 100 nm, and more preferably 40 to 60 nm. When the average particle diameter is less than 10 nm, the hollow silica particles 20 are likely to aggregate, and thus the uniform dispersion of the hollow silica particles 20 may not be easy. Further, when the average particle diameter exceeds 100 nm, the transparency of the low refractive index layer 10a may be lowered.

  Here, the average particle diameter is an arithmetic average value of the particle diameter of the hollow silica particles 20 (the diameter when the hollow silica particles 20 are assumed to be spheres). The particle size of the hollow silica particles 20 is measured by, for example, a laser diffraction / scattering particle size distribution meter (specifically, HORIBA LA-920). The laser diffraction / scattering particle size distribution analyzer is not limited to HORIBA LA-920. Moreover, although the refractive index of the hollow silica particle 20 changes according to the refractive index requested | required of the low refractive index layer 10a, it will be 1.10-1.40, for example, Preferably it will be 1.15-1.25. The refractive index of the hollow silica particles 20 is measured by, for example, simulation software (Lambda Research TracePro).

  The content of the hollow silica particles 20 (mass% with respect to the total mass of the hollow silica particles 20, the binder resin 30, the additive 40, and the photoinitiator) is 30 to 60% by mass. As will be described later, when the content of the hollow silica particles 20 falls within this range, the characteristics of the resin film 10 are improved. A more preferable content of the hollow silica particles is 40% by mass or more and 50% by mass or less. When the content of the hollow silica particles falls within this range, the characteristics of the resin film 10 are further improved.

  The binder resin 30 has a network structure and connects the hollow silica particles 20 to each other. The monomer constituting the binder resin 30, that is, the binder monomer has a hydrogen bond forming group and two or more photopolymerizable functional groups. The hydrogen bond forming group is a functional group capable of forming a hydrogen bond with another functional group, and is, for example, a hydroxyl group. The hydrogen bond forming group is not limited to this example, but a hydrogen bond (that is, a nitrogen atom in which a hydrogen atom bonded to another atom by a covalent bond is located in the vicinity of the hydrogen atom, oxygen, sulfur, fluorine, π electron system) Any functional group may be used as long as it forms a non-covalent attractive interaction with a lone electron pair. As described above, the photopolymerizable functional group is, for example, an acryloyl group or a methacryloyl group. Therefore, the binder monomer is a polyfunctional acrylate monomer.

  Here, since the binder resin 30 is obtained by polymerizing a binder monomer having a hydrogen bond-forming group, the additive 40 described later can be effectively bleed out. That is, since the binder resin 30 has a hydrogen bond forming group, the surface tension is increased. On the other hand, since the additive 40 is a fluoropolymer, the surface tension is low. Therefore, the additive 40 effectively bleeds out by repelling the binder resin 30. The surface tension of the binder monomer is preferably 36 or more and 45 or less. When the surface tension falls within this range, the additive 40 effectively bleeds out. The surface tension is measured by, for example, an automatic surface tension meter (specifically, Kyowa Interface Science DY-300). The automatic surface tension meter is not limited to Kyowa Interface Science DY-300.

  Binder monomers include diacrylates such as glycerin di (meth) acrylate, 2-hydroxy-3-acryloyloxypropyl (meth) acrylate, isocyanurate acrylate, tri (meth) acrylates such as pentaerythritol (meth) acrylate, Examples thereof include penta (meth) acrylate such as pentaerythritol (meth) acrylate derivative and dipentaerythritol (meth) acrylate. Of course, the monomer for binder may be other than these. That is, the binder monomer may be any as long as it has a hydrogen bond forming group and two or more photopolymerizable functional groups.

  Since the binder monomers have a total of three or more functional groups, the binder resin 30 having a complicated three-dimensional structure (network structure) is formed by polymerizing each other. That is, the hydrogen bond-forming group of the binder monomer is thermally polymerized (condensation polymerization) with the thermally polymerizable functional group of the hollow silica particle 20 or the hydrogen bond-forming group of another binder monomer. Further, the photopolymerizable functional group of the binder monomer is photopolymerized with the photopolymerizable functional group of the hollow silica particle 20 or the photopolymerizable functional group of another binder monomer. Thereby, the binder resin 30 having a complicated three-dimensional structure (network structure) is formed. Moreover, since the binder monomer bleeds out the additive 40, the additive 40 remaining in the low refractive index layer 10a can be reduced. Therefore, the crosslinking density of the binder resin 30 is improved, and consequently the mechanical strength of the low refractive index layer 10a is improved.

  In some cases, the hollow silica particles 20 are directly bonded to each other. That is, the thermally polymerizable functional group of the hollow silica particle 20 is bonded to the thermally polymerizable functional group of the other hollow silica particle 20, and the photopolymerizable functional group of the hollow silica particle 20 is the light of the other hollow silica particle 20. Bonds with a polymerizable functional group. Such bonding is possible because, as will be described later, the hollow silica particles 20 are not modified in advance when the resin film 10 is manufactured.

  In contrast, for example, in Patent Document 3, the hollow silica particles are modified with a silane coupling agent in advance (the silane coupling agent is bonded to the functional group of the hollow silica particles). And a low refractive index layer is produced | generated using the hollow silica particle modified with the silane coupling agent. For this reason, it becomes difficult for hollow silica particles to approach and by extension, it becomes difficult to couple | bond together directly. Further, since the silane coupling agent has a linear structure, even if the silane coupling agents are bonded to each other, a complicated network structure as in the present embodiment is not formed. Therefore, the strength of the low refractive index layer of Patent Document 3 is lower than that of the low refractive index layer 10a of the present embodiment.

  The additive 40 is added to impart antifouling properties and slipperiness to the low refractive index layer 10a. The additive 40 is specifically composed of a photopolymerizable fluoropolymer 41 and a thermopolymerizable fluoropolymer 42.

  The photopolymerizable fluoropolymer is a fluoropolymer having a photopolymerizable functional group, and is represented by the following chemical formula (1).

  In chemical formula (1), Rf1 represents a (per) fluoroalkyl group or (per) fluoropolyether group, W1 represents a linking group, and RA1 represents a functional group having a polymerizable unsaturated group, that is, a photopolymerizable functional group. n represents an integer of 1 to 3, and m represents an integer of 1 to 3.

The structure of the (per) fluoroalkyl group is not particularly limited. That is, the (per) fluoroalkyl group is a straight chain (for example, —CF ₂ CF ₃ , —CH ₂ (CF ₂ ) ₄ H, —CH ₂ (CF ₂ ) ₈ CF ₃ , —CH ₂ CH ₂ (CF ₂ ). ₄ H, etc.) even in a branched structure (eg, CH (CF ₃ ) ₂ , CH ₂ CF (CF ₃ ) ₂ , CH (CH ₃ ) CF ₂ CF ₃ , CH (CH ₃ ) (CF ₂ ) ₅ CF ₂ H) or an alicyclic structure (preferably a 5-membered or 6-membered ring such as a perfluorocyclohexyl group, a perfluorocyclopentyl group, or an alkyl group substituted with these). good.

The (per) fluoropolyether group is a (per) fluoroalkyl group having an ether bond, and the structure thereof is not particularly limited. That is, as the (per) fluoropolyether group, for example, CH ₂ OCH ₂ CF ₂ CF ₃ , CH ₂ CH ₂ OCH ₂ C ₄ F ₈ H, CH ₂ CH ₂ OCH ₂ CH ₂ C ₈ F ₁₇ , CH ₂ CH _{2 OCF 2 CF 2 OCF 2 CF} 2 H, fluorocycloalkyl ether group having 4 to 20 carbon atoms such as a fluorine atom 5 or more can be mentioned. Other examples include (CF ₂ ) _x O (CF ₂ CF ₂ O) _y , [CF (CF ₃ ) CF ₂ O] _x- [CF ₂ (CF ₃ )], (CF ₂ CF ₂ CF ₂ O) _x , (CF ₂ CF ₂ O) _{x and the} like. Here, x and y are arbitrary natural numbers.

  The linking group is not particularly limited, and examples thereof include a methylene group, a phenylene group, an alkylene group, an arylene group, a heteroalkylene group, or a combination group in which these are combined. These linking groups may further have a carbonyl group, a carbonyloxy group, a carbonylimino group, a sulfonamide group, or the like, or a functional group obtained by combining these. Examples of the photopolymerizable functional group include an acryloyl group and a methacryloyl group.

  The weight average molecular weight Mw of the photopolymerizable fluoropolymer 41 is smaller than the weight average molecular weight Mw of the thermopolymerizable fluoropolymer 42 described later, preferably less than 10,000. The lower limit of the weight average molecular weight Mw of the photopolymerizable fluoropolymer is not particularly limited, but is, for example, 3000 or more. In addition, the oleic acid falling angle of the photopolymerizable fluoropolymer 41 is selected according to the antifouling property and slipperiness required for the resin film 10 and is, for example, 10 degrees or less. The oleic acid falling angle is measured by, for example, a fully automatic contact angle meter DM700 (manufactured by Kyowa Interface Science Co., Ltd.).

  The thermopolymerizable fluoropolymer 42 is a fluoropolymer having a thermopolymerizable functional group, and is represented by the following chemical formula (2).

  In chemical formula (2), Rf2 is a (per) fluoroalkyl group or (per) fluoropolyether group, W2 is a linking group, and X is a thermally polymerizable functional group, such as an alkoxy group having 1 to 4 carbon atoms or a silanol group. , Halogen or hydrogen. n represents 1-3. The thermally polymerizable functional group is a concept including the above-described hydrogen bond forming group.

  The structures of (per) fluoroalkyl group, (per) fluoropolyether group, and linking group are the same as those of the photopolymerizable fluoropolymer. The weight average molecular weight Mw of the thermopolymerizable fluoropolymer is larger than the weight average molecular weight Mw of the photopolymerizable fluoropolymer, preferably 10,000 or more. In addition, although the upper limit of the weight average molecular weight Mw of a thermopolymerizable fluoropolymer is not specifically limited, For example, it will be 50000 or less. In addition, the oleic acid falling angle of the photopolymerizable fluoropolymer 41 is selected according to the antifouling property and slipperiness required for the resin film 10 and is, for example, 10 degrees or less.

  Thus, since the photopolymerizable fluoropolymer 41 and the thermopolymerizable fluoropolymer 42 have a fluoropolymer portion as a basic skeleton, the fluoropolymer portion and the hydrogen bond forming group of the binder resin 30 repel each other. Thereby, the photopolymerizable fluoropolymer 41 and the thermopolymerizable fluoropolymer 42 effectively bleed out (that is, unevenly distributed on the surface of the low refractive index layer 10a).

  The photopolymerizable fluoropolymer 41 is bonded to the photopolymerizable functional groups of the hollow silica particles 20 and the binder resin 30 distributed on the surface of the low refractive index layer 10a, and the thermopolymerizable fluoropolymer 42 is combined with the low refractive index layer. The hollow silica particles 20 distributed on the surface of 10a and the thermally polymerizable functional groups of the binder resin 30 are bonded. Thus, in this embodiment, the hollow silica particles 20 and the binder resin 30 arranged on the surface of the low refractive index layer 10a are protected by the photopolymerizable fluoropolymer 41 and the thermopolymerizable fluoropolymer 42.

  On the other hand, conventionally, only a photopolymerizable polymer has been used as an additive. Therefore, in the conventional low refractive index layer, the hydroxyl portion of the hollow silica particles arranged on the surface was exposed. For this reason, there existed a problem that the antifouling property and slipperiness of a low refractive index layer fell remarkably.

  On the other hand, in this embodiment, the hollow silica particles 20 disposed on the surface of the low refractive index layer 10a are protected by the photopolymerizable fluoropolymer 41 and the thermopolymerizable fluoropolymer 42. That is, the hydroxyl group of the hollow silica particle 20 is also protected by the thermally polymerizable fluoropolymer 42. Therefore, in this embodiment, since the surface of the low refractive index layer 10a can be uniformly protected by the photopolymerizable fluoropolymer 41 and the thermopolymerizable fluoropolymer 42, antifouling properties and slipperiness are improved.

  Further, the weight average molecular weight Mw of the thermopolymerizable fluoropolymer 42 is larger than the weight average molecular weight Mw of the photopolymerizable fluoropolymer 41. The reason why the weight average molecular weight Mw of the photopolymerizable fluoropolymer 41 and the thermopolymerizable fluoropolymer 42 is set in this way is as follows. That is, the photopolymerizable fluoropolymer 41 and the thermopolymerizable fluoropolymer 42 are preferable because the surface tension decreases as the weight average molecular weight Mw increases (that is, the antifouling property, the slip property, and the bleed out property are improved).

  However, since the acryloyl group and the methacryloyl group have a large polarity, if the weight average molecular weight Mw of the fluoropolymer is too large, it becomes difficult to introduce these functional groups into the fluoropolymer. That is, it becomes difficult to produce the photopolymerizable fluoropolymer 41. Further, when the weight average molecular weight Mw is too large, the photopolymerizable fluoropolymer 41 and the thermopolymerizable fluoropolymer 42 are difficult to dissolve in a solvent during the production of the resin film 10 (specifically, compatibility with the binder monomer). Decreases).

  Therefore, the weight average molecular weight Mw of the photopolymerizable fluoropolymer 41 was set as described above. Thereby, since the weight average molecular weight Mw of the fluoropolymer in which an acryloyl group and a methacryloyl group are introduced can be reduced, the acryloyl group and the methacryloyl group can be easily introduced into the fluoropolymer.

  Further, the photopolymerizable fluoropolymer 41 plays a role of a compatibilizer with respect to the thermopolymerizable fluoropolymer 42. That is, the thermopolymerizable fluoropolymer 42 is easily dissolved in the solvent by being charged into the solvent together with the photopolymerizable fluoropolymer 41 having a small weight average molecular weight Mw. That is, in this embodiment, by increasing the weight average molecular weight Mw of the thermopolymerizable fluoropolymer 42, the weight average molecular weight Mw of the entire additive 40 is increased, while the weight average molecular weight Mw of the photopolymerizable fluoropolymer 41 is increased. By making it small, the additive 40 is easily dissolved in the solvent.

  In addition, the content rate (mass% with respect to the total mass of the hollow silica particle 20, the binder resin 30, the additive 40, and a photoinitiator) of the additive 40 is larger than 1 mass%, and becomes 7 mass% or less. Preferably they are 2 mass% or more and 7 mass% or less, More preferably, they are 4 mass% or more and 6 mass% or less. Moreover, the content rate (mass% with respect to the total mass of the hollow silica particle 20, the binder resin 30, the additive 40, and a photoinitiator) of the thermopolymerizable fluoropolymer 42 is 2 mass% or less. Although a lower limit is not specifically limited, For example, 0.5 mass% or more is preferable. Further, the ratio of the content of the heat-polymerizable fluoropolymer 42 and the content of the photopolymerizable fluoropolymer 41 is 0.1 or more and 0.7 or less. More preferably, it is 0.3 or more and 0.5 or less. When these conditions are satisfied, the characteristics of the resin film 10 are improved.

  The photoinitiator is a material for initiating photopolymerization, and the type thereof is not limited. That is, in this embodiment, any photoinitiator can be used. However, it is preferable that the photoinitiator is less susceptible to oxygen inhibition and has good surface curability.

<2. Manufacturing Method of Resin Film 10>
Next, a method for manufacturing the resin film 10 will be described. First, the hollow silica particles 20, the photoinitiator, the binder monomer, and the additive 40 are charged into a solvent and stirred to generate a coating solution. The type of the solvent is not particularly limited, but a ketone solvent having a boiling point of 110 ° C. or higher is preferably used. This is because this solvent can dissolve each material stably and can easily bleed out the photopolymerizable fluoropolymer 41 and the thermopolymerizable fluoropolymer 42. Next, a coating layer is formed by applying (coating) the coating liquid to an arbitrary substrate. In addition, the application method is not particularly limited, and a known method is arbitrarily applied. At this time, the photopolymerizable fluoropolymer 41 and the thermopolymerizable fluoropolymer 42 bleed out due to the repulsive force from the binder monomer and are unevenly distributed on the surface of the coating layer. Subsequently, each polymerization reaction is started. Thereby, while the binder resin 30 is formed, the photopolymerizable fluoropolymer 41 and the thermopolymerizable fluoropolymer 42 are bonded to the hollow silica particles 20 arranged on the surface of the coating layer. Thereby, the resin film 10 is formed.

  Thus, since the binder monomer can effectively bleed out the photopolymerizable fluoropolymer 41 and the thermopolymerizable fluoropolymer 42, the resin film 10 according to this embodiment is manufactured by a very simple process. Is done. Further, since the additive 40 is unevenly distributed on the surface of the low refractive index layer 10a, it is not necessary to separately attach an antifouling sheet or the like to the surface of the low refractive index layer 10a.

Example 1
Next, examples of the present embodiment will be described. In Example 1, the resin film 10 was manufactured by the following manufacturing method.

  45% by mass (parts by mass) of pentaerythritol triacrylate as a monomer for binder, 50% by mass of hollow silica particles (JGC Catalysts and Chemicals Thruria 4320), and 1.8% by mass of photopolymerizable perfluoropolyether (PFPE) as additives. ) (Shin-Etsu Chemical KY-1203) and 0.2% by mass of thermopolymerizable PFPE (Shin-Etsu Chemical KY-108) and 3% by mass of Irgacure 184 (manufactured by Nagase Sangyo Co., Ltd.) were prepared as photoinitiators. Then, these materials were put into 8000% by mass of methyl isobutyl ketone (MIBK) and stirred to prepare a coating solution.

  Here, the average particle diameter of the hollow silica particles was 50 nm to 60 nm. The refractive index of the hollow silica particles was 1.25. The surface tension of pentaerythritol triacrylate was 39.8. Moreover, the weight average molecular weight Mw of photopolymerizable PFPE was 8000, and the oleic acid sliding angle was 5 °. The heat-polymerizable PFPE had a weight average molecular weight Mw of 17000 and an oleic acid falling angle of 7 °. Note that the measurement was performed by the above-described apparatus or simulation software.

Subsequently, the coating layer was formed by apply | coating a coating liquid on a board | substrate. Next, the coating layer was dried at 110 ° C. for about 1 minute, and then cured by irradiation with ultraviolet rays (metal halide lamp: light quantity: 1000 mJ / cm ² ) for 5 seconds in a nitrogen atmosphere (oxygen concentration of 1000 ppm or less). Thereby, a resin film was prepared. The thickness of the resin film was about 110 nm.

(Examples 2-14, Comparative Examples 1-20)
Except for changing the content of each material, the type of photopolymerizable resin, the type of thermopolymerizable resin, and the type of binder monomer, Examples 2 to 14, And the resin film which concerns on Comparative Examples 1-20 was created. Here, Table 1 shows the content of each material and the types of binder monomers.

  Among the acrylic resin items, * 1 represents a binder monomer having no hydrogen bond forming group (specifically, a hydroxyl group), that is, pentaerythritol tetraacrylate (38.9). * 2 shows a hydroxyl group-containing binder monomer, that is, isocyanurate diacrylate (40.2). * 3 indicates a hydroxyl group-containing binder monomer, that is, dipentaerythritol pentaacrylate (39.7). * 4 shows photopolymerizable silicone X-22-164E (manufactured by Shin-Etsu Chemical Co., Ltd.). * 5 indicates a photopolymerizable fluororesin, that is, OPTOOL DAC (manufactured by Daikin Industries). * 6 indicates a thermally polymerizable fluororesin, that is, KY-164 (manufactured by Shin-Etsu Chemical Co., Ltd.). * 7 represents a binder monomer having no hydrogen bond-forming group (specifically, a hydroxyl group), that is, ethoxylated (n = 6) trimethylolpropane triacrylate (38.9). * 8 represents a binder monomer having no hydrogen bond forming group (specifically, a hydroxyl group), that is, propoxylated (n = 6) trimethylolpropane triacrylate (34.1). No mark indicates a hydroxyl group-containing binder monomer, that is, pentaerythritol triacrylate (39.8). The numerical value (the numerical value in parentheses) attached to each binder monomer indicates the surface tension of each binder monomer.

(test)
Next, the following tests were performed on the resin films according to the respective examples and comparative examples.

(Wipe rubbing test)
The surface of the substrate coated with the resin film was subjected to 100 reciprocating abrasions with a wipe while applying a load of 500 g / cm ^{2 in} the vertical direction. The wipe used was a Kim wipe wiper S-200 manufactured by Nippon Paper Crecia.

(Eraser abrasion test)
The surface of the substrate coated with the resin film was subjected to 100 round-trip wear with an eraser while applying a load of 500 g / cm ^{2 in} the vertical direction. As the eraser, MONOPE-04A manufactured by Dragonfly Pencil Co., Ltd. was used.

(Evaluation)
The following evaluation was performed on each resin film in the initial stage (before performing the cotton rubbing test and the eraser rubbing test), after the cotton rubbing test, and after the eraser rubbing test.

(Contact angle evaluation)
Using a fully automatic contact angle meter DM700 (manufactured by Kyowa Interface Science Co., Ltd.), 2 μl of pure water was dropped onto a substrate coated with a resin film, and the contact angle was measured.

(Magic wiping evaluation)
An approximately 3 cm line was drawn with a magic pen on the surface of the substrate coated with the resin film (that is, the surface of the resin film) and left for 1 minute. After that, I wiped like a circle with Kimwipe. The magic pen used was ZEBRA's McKee Black fine, and the Kim wipe was the same as in the wipe rubbing test. Then, the presence or absence of wiping residue was confirmed visually. No wiping residue was OK, and wiping residue was NG.

(Fingerprint adhesion and wiping evaluation)
The fingerprint of the fingertip was pressed against the surface of the substrate coated with the resin film (that is, the surface of the resin film) so that the load was about 200 g. Then, the presence or absence of the fingerprint was confirmed with the finger. Evaluate as “large” when the fingerprint of the pressed part can be clearly confirmed, “slightly” when part of the fingerprint of the pressed part can be confirmed, and “less” when the fingerprint of the pressed part can be confirmed as faint. did. After that, the fingerprint was wiped like a circle with Kimwipe. Kim wipes were the same as in the wipe rubbing test. Then, the presence or absence of wiping residue was confirmed visually. No wiping residue was OK, and wiping residue was NG. The evaluation results are shown in Table 2.

  When the example and the comparative example were compared, in the example, not only the initial characteristics but also the characteristics after the rubbing test were good. On the other hand, in the comparative example, the initial characteristics were good except for the comparative example 16, but the result after the rubbing test was not good. Therefore, it can be seen that the content of each material is preferably in the above-described range.

  As described above, according to the present embodiment, the resin film 10 includes the additive 40 that binds to the hollow silica particles distributed on the surface of the low refractive index layer 10 a and repels the binder resin 30. Therefore, the additive 40 effectively bleeds out due to the repulsive force of the binder resin 30, so that the resin film 10 can cause the additive 40 to be unevenly distributed on the surface of the low refractive index layer 10 a. Thereby, the resin film 10 can improve antifouling property and slipperiness, and can improve film | membrane intensity | strength.

  Furthermore, since the binder resin 30 has a hydrogen bond forming group, the additive 40 can be effectively bleed out.

  Moreover, since the binder resin 30 has a hydroxyl group as a hydrogen bond forming group, the additive 40 can be effectively bleed out.

  Further, the weight average molecular weight of the thermally polymerizable fluoropolymer 42 is larger than the weight average molecular weight of the photopolymerizable fluoropolymer 41. Therefore, the additive 40 can effectively bleed out. Moreover, since the photopolymerizable fluoropolymer 41 functions as a compatibilizing agent, the solubility of the additive 40 in the solvent is improved.

  Furthermore, since the weight average molecular weight of the thermopolymerizable fluoropolymer is 10,000 or more and the weight average molecular weight of the photopolymerizable fluoropolymer is less than 10,000, the additive 40 can effectively bleed out. Moreover, since the photopolymerizable fluoropolymer 41 functions as a compatibilizing agent, the solubility of the additive 40 in the solvent is improved.

  The resin film 10 can be easily formed because it can be formed simply by applying a coating solution in which each material is dissolved and starting a polymerization reaction.

  The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited to such examples. It is obvious that a person having ordinary knowledge in the technical field to which the present invention pertains can come up with various changes or modifications within the scope of the technical idea described in the claims. Of course, it is understood that these also belong to the technical scope of the present invention.

DESCRIPTION OF SYMBOLS 10 Resin film | membrane 20 Hollow silica particle 30 Binder resin 40 Additive 41 Photopolymerizable fluoropolymer 42 Thermopolymerizable fluoropolymer

Claims (6)

A low refractive index layer comprising a plurality of hollow silica particles and a binder resin that bonds the hollow silica particles;
A photopolymerizable fluoropolymer and a thermopolymerizable fluoropolymer that bind to the hollow silica particles distributed on the surface of the low refractive index layer and repel the binder resin;
The content of the hollow silica particles is 30% by mass or more and 60% by mass or less,
The total content of the photopolymerizable fluoropolymer and the thermopolymerizable fluoropolymer is more than 1% by mass and 7% by mass or less,
The content of the thermopolymerizable fluoropolymer is 2% by mass or less,
The ratio of the content rate of the said thermopolymerizable fluoropolymer and the content rate of the said photopolymerizable fluoropolymer is 0.1 or more and 0.7 or less, The resin film characterized by the above-mentioned.   The resin film according to claim 1, wherein the binder resin has a hydrogen bond forming group capable of forming a hydrogen bond with another functional group.   The resin film according to claim 2, wherein the binder resin has a hydroxyl group as the hydrogen bond forming group.   The resin film according to any one of claims 1 to 3, wherein a weight average molecular weight of the thermopolymerizable fluoropolymer is larger than a weight average molecular weight of the photopolymerizable fluoropolymer.   The resin film according to claim 4, wherein the thermopolymerizable fluoropolymer has a weight average molecular weight of 10,000 or more, and the photopolymerizable fluoropolymer has a weight average molecular weight of less than 10,000. A hollow silica particle, a binder monomer capable of binding the hollow silica particles, a photopolymerizable fluoropolymer and a thermopolymerizable fluoropolymer capable of binding to the hollow silica particle and repelling the binder monomer; Producing a coating liquid comprising:
Applying the coating solution to a substrate;
Initiating a polymerization reaction, and
The content of the hollow silica particles is 30% by mass or more and 60% by mass or less,
The total content of the photopolymerizable fluoropolymer and the thermopolymerizable fluoropolymer is more than 1% by mass and 7% by mass or less,
The content of the thermopolymerizable fluoropolymer is 2% by mass or less,
The method for producing a resin film, wherein the ratio of the content of the heat-polymerizable fluoropolymer and the content of the photopolymerizable fluoropolymer is 0.1 or more and 0.7 or less.

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