JP2013010323A - Hard coat film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hard coat film which hardly generates cracks in the edge part in stamping although its both surfaces composed of a hard coat film, and has excellent pen sliding durability.SOLUTION: The hard coat film is constituted of a hard coat layer A formed on one surface of a base film and a hard coat layer B formed on the other surface. The thickness of the hard coat layer A is 2-10 μm, and the thickness of the hard coat layer B is 0.05-2.5 μm. The thickness of the hard coat layer A is not less than 0.5 μm greater than that of the hard coat layer B. The hard coat layer A has unevenness that is formed by the phase separation of two or more components.

Description

  The present invention relates to a hard coat film. In particular, the present invention relates to a hard coat film that is suitable for punching and has excellent pencil hardness and pen sliding durability, and is particularly suitable for use as an icon sheet.

In recent years, a touch panel can be operated while looking at the screen by providing a transparent or translucent input device directly on a display such as an LCD (Liquid Crystal Display), and can be easily operated by anyone. Also, since it is possible to input characters and pictures, it has come to be widely used as a man / machine interface.
The touch panel includes an optical method, an ultrasonic method, an electromagnetic induction method, a capacitance method, a resistance film method, and the like, but a resistance film method is mainly used for medium to small touch panels. Moreover, although the material used for the surface of a touch panel changes with these systems, in many cases, the hard coat film which provided the material with some high hardness in the plastic film is used.

  There are various applications for touch panels such as ATM terminals, car navigation systems, smartphones, portable music playback terminals, game machines, etc., especially recent thinning, improved design, and a wide variety of designs. With this trend, hard coat films used on the surface of touch panels are often integrated with the touch panel by printing frames, icons, logos, etc. on the back side (the surface on the touch panel side of the hard coat film). I came. Such a hard coat film printed on the back surface is often called an icon sheet. This icon sheet is generally made of a plastic film with a hard coat treatment on one side, vapor deposition processing to improve the design on the opposite side of the hard coat treatment, and printing of a frame or logo. It is manufactured by, for example, etching the deposited portion. Then, a plurality (about 10 to 30) of icon sheets are made from one processed sheet obtained by this series of processes, and finally cut (punched) into a necessary size and provided to the touch panel manufacturer. Is done.

On the other hand, the hard coat film used on the touch panel surface is subjected to an input operation using, for example, a polyacetal pen on the front surface (the surface on the input side of the hard coat film). For this reason, such a hard coat layer is required to have pen sliding durability, and for example, there is a report in Patent Document 1 as a technique for improving it.
In the icon sheet manufacturing as described above, the back side of the single-sided hard coat film is processed such as printing. However, in order to meet the demand for higher quality in recent years, the back side applied during each processing is scratched. If it is attached, the quality will be insufficient and the yield will be reduced. Therefore, it is conceivable to provide a hard coat layer on the back surface (for example, Patent Document 2). However, in such a case, there is a problem that a crack is generated at the edge portion during punching. Moreover, it cannot be said that the pen sliding durability is sufficient only by providing a hard coat on the front surface.

JP 2007-70456 A Japanese Patent Laid-Open No. 10-16111

  An object of the present invention is to provide a hard coat film which is a double-sided hard coat film but hardly cracks at the edge portion during punching and has excellent pen sliding durability.

The present inventor has intensively studied to solve the above problems. As a result, for the hard coat layers on the front and back sides, the thickness and thickness difference of each of the hard coat layers are in a specific numerical range, and the hard coat layer on the front surface has irregularities due to phase separation, so that cracks are generated during punching. The present inventors have found that it is difficult to occur and is excellent in pencil hardness and pen sliding durability.
The present invention employs the following configuration in order to solve the above problems.
1. A hard coat film having a hard coat layer A on one surface and a hard coat layer B on the other surface, wherein the thickness of the hard coat layer A is 2 μm or more and 10 μm or less, and the thickness of the hard coat layer B Is 0.05 μm or more and 2.5 μm or less, and the thickness of the hard coat layer A is 0.5 μm or more thicker than that of the hard coat layer B. The hard coat layer A is formed by phase separation of two or more components. Hard coat film having unevenness.
2. 2. The hard coat film according to 1 above, wherein the hard coat layer A does not contain fine particles for imparting irregularities.
3. The hard coat film as described in 1 or 2 above, wherein the center line average roughness (Ra) on the surface of the hard coat layer A is 1 nm or more and 300 nm or less, and the 10-point average roughness (Rz) is 25 nm or more and 2,000 nm or less. .
4). Hard coat film of any one of said 1-3 which has an easily bonding layer which contains a polyester resin and a crosslinking agent as a structural component between a base film and hard coat layer A and / or hard coat layer B. .
5. The hard coat layer A is composed of a curable resin composition A, and the curable resin composition A includes an unsaturated double bond-containing acrylic copolymer as a first component and a polyfunctional unsaturated double as a second component. 5. The hard coat film according to any one of the above 1 to 4, comprising a bond-containing monomer or an oligomer thereof as a main component.
6). The hard coat layer B is made of a curable resin B, and the curable resin B is mainly composed of a polyfunctional (meth) acrylate monomer, a polyfunctional (meth) acrylate oligomer, or a polyfunctional (meth) acrylate polymer. The hard coat film according to any one of 1 to 5.

  Although the hard coat film of the present invention is a double-sided hard coat film, cracks are hardly generated at the edge portion during punching and the pen sliding durability is excellent.

<Hard coat film>
The hard coat film of the present invention has a hard coat layer A on one side of the base film and a hard coat layer B on the other side.

<Hard coat layer A>
The hard coat layer A in the present invention is a layer provided on the outermost surface in the final product when the hard coat film of the present invention is used for a touch panel, particularly for an icon sheet, and therefore it is desirable that the hardness is higher. The thickness of the hard coat layer A is not particularly limited as long as the hardness can secure a pencil hardness of 2H or more, preferably 3H or more, but the lower limit is 2 μm or more. Thereby, it is excellent in pen sliding durability. The thickness is preferably 3.5 μm or more, and not only scratches that are cohesive failure, but also dents in plastic deformation become inconspicuous. From such a viewpoint, the thickness of the hard coat layer A is more preferably 4.5 μm or more. On the other hand, the upper limit is 10 μm or less, preferably 8.5 μm or less, more preferably 7 μm or less. If the thickness of the hard coat layer A is too thick, the hard coat layer A shrinks due to heat when the hard coat layer A is cured or after processing such as vapor deposition or printing, and the hard coat film is easily curled. And tend to cause problems when pasting together. Moreover, it exists in the tendency which can suppress the crack generation | occurrence | production of the edge part at the time of stamping more by making the thickness of the hard-coat layer A into the said numerical range.
In addition, the hardness of the hard coat layer A is appropriately selected from the curable resin composition A described later constituting the hard coat layer A described later, the thickness of the hard coat layer A is adjusted, and the addition of a photopolymerization initiator is further added. It can be easily adjusted by adjusting the amount and UV irradiation intensity, or adjusting the oxygen concentration by purging with N ₂ during UV irradiation.
Further, the thickness of the hard coat layer A can be easily adjusted by the coating amount of the curable resin composition A described later constituting the hard coat layer A.

  The hard coat layer A in the present invention has irregularities formed by phase separation of two or more components on the surface thereof. By having such irregularities, the pen sliding durability is excellent. In the present invention, the hard coat layer A preferably has no fine particles for imparting irregularities to the surface. By such an aspect, the improvement effect of pen sliding durability can be made high. In other words, the pen sliding durability can be improved by having irregularities on the surface, but when such irregularities are formed by fine particles, the fine particles fall off from the hard coat layer when written with a pen. This is because the phenomenon that the surface is scraped off by the dropped fine particles is likely to occur, and the effect of improving the pen sliding durability is lowered.

  Moreover, 1 nm or more is preferable and the centerline average roughness (Ra) in the hard-coat layer A surface in this invention can make the improvement effect of pen sliding durability high. From such a viewpoint, Ra is more preferably 5 nm or more, further preferably 8 nm or more, and particularly preferably 11 nm or more. On the other hand, when Ra is too large, the effect of improving transparency is lowered. Therefore, 300 nm or less is preferable, 200 nm or less is more preferable, and 160 nm or less is more preferable. Furthermore, the 10-point average roughness (Rz) on the surface of the hard coat layer A in the present invention is preferably 25 nm or more, and the effect of improving pen sliding durability can be enhanced. From such a viewpoint, Rz is more preferably 45 nm or more, further preferably 55 nm or more, and particularly preferably 80 nm or more. On the other hand, when Rz is too large, the effect of improving transparency is lowered. Therefore, it is preferably 2,000 nm or less, more preferably 1,500 nm or less, and even more preferably 1,300 nm or less. If Ra and Rz are simultaneously in the above numerical range, the effect of improving pen sliding durability can be further enhanced. Moreover, winding property becomes favorable because it is Ra and Rz as mentioned above.

Further, in the present invention, the hard coat layer A has surface irregularities as described above, thereby improving the slipping property when winding the hard coat film of the present invention, and winding it without laminating a protective film. In addition, blocking can be made difficult to occur when the icon sheets are printed and superimposed on each other.
In order to achieve such an aspect of Ra and Rz, the solvent and drying conditions used when forming the hard coat layer A may be adjusted, or the components for phase separation may be adjusted. For example, the surface tends to become rough when dried quickly using a low-boiling solvent. Moreover, when it is easy to mutually phase-separate, it exists in the tendency which becomes coarse.
In the present invention, such a hard coat layer A can be formed by using, for example, the following curable resin composition A.

<Curable resin composition A>
The hard coat layer A in the present invention has irregularities formed by phase separation of two or more components, and comprises the following curable resin composition A. The curable resin composition A includes at least two kinds of components, a first component and a second component. When the curable resin composition A is applied onto the base film, the first component and the second component are based on the difference in physical properties between the first component and the second component. And are phase-separated.

  The first component is made of at least one resin and the second component is selected from the group consisting of at least one monomer or oligomer.

  As the first component resin, for example, (meth) acrylic resin, olefin resin, polyether resin, polyester resin, polyurethane resin, polysiloxane resin, polysilane resin, polyimide resin, or resin containing a fluorinated resin in a skeleton structure is used. be able to. These resins may be so-called oligomers having a low molecular weight. As a resin containing a (meth) acrylic resin in its skeleton structure, a resin obtained by polymerizing or copolymerizing a (meth) acrylic monomer, a resin obtained by copolymerizing a (meth) acrylic monomer and another monomer having an ethylenically unsaturated double bond Etc. Examples of the resin containing an olefin resin in the skeleton structure include polyethylene, polypropylene, ethylene / propylene copolymer, ethylene / vinyl acetate copolymer, ionomer, ethylene / vinyl alcohol copolymer, and ethylene / vinyl chloride copolymer. . The resin containing a polyether resin in the skeleton structure is a resin containing an ether bond in the molecular chain, and examples thereof include polyethylene glycol, polypropylene glycol, and polytetramethylene glycol. The resin containing a polyester resin in the skeleton structure is a resin containing an ester bond in the molecular chain, and examples thereof include an unsaturated polyester resin, an alkyd resin, and polyethylene terephthalate. A resin including a polyurethane resin in a skeleton structure is a resin including a urethane bond in a molecular chain. The resin containing a polysiloxane resin in the skeleton structure is a resin containing a siloxane bond in the molecular chain. A resin containing a polysilane resin in a skeleton structure is a resin containing a silane bond in a molecular chain. A resin including a polyimide resin in a skeleton structure is a resin including an imide bond in a molecular chain. The resin containing a fluorinated resin in the skeleton structure is a resin containing a structure in which part or all of hydrogen of polyethylene is replaced with fluorine. The resin may be a copolymer composed of two or more of the above skeleton structures, or may be a copolymer composed of the above skeleton structures and other monomers.

The first component resin preferably has a weight average molecular weight of 2,000 to 100,000, more preferably 5,000 to 50,000.
The first component resin preferably has a lower limit of the glass transition temperature (Tg) of 2 ° C. or higher, preferably 10 ° C. or higher, more preferably 50 ° C. or higher. On the other hand, the upper limit of the glass transition point is 200 ° C., preferably 150 ° C. The glass transition temperature can be obtained by a method similar to the method for measuring Tg by ordinary dynamic viscoelasticity. This Tg is, for example, RHEOVIBRON
It can be measured using MODEL RHEO 2000, 3000 (trade name, manufactured by Orientec). When the glass transition temperature is lower than 2 ° C., the antiblocking function is lowered.

  The second component is a monomer or an oligomer. As the monomer, a multifunctional monomer, for example, a dealcoholization reaction product of a polyhydric alcohol and (meth) acrylate, specifically, dipentaerythritol hexa (meth) acrylate, Trimethylolpropane tri (meth) acrylate and the like can be used. Examples of the oligomer include urethane (meth) acrylate oligomers, polyester (meth) acrylate oligomers, and low molecular weight products of the resins mentioned in the first component, particularly 3 to 10 repeating units and a weight average molecular weight of 8,000. Less than. The oligomer may be a copolymer composed of two or more of the aforementioned skeleton structures of the resin, or may be a copolymer composed of the skeleton structure and other monomers.

  Moreover, it is preferable that the 1st component and 2nd component in this invention each have a functional group which mutually reacts. The resistance of the hard coat layer A can be increased by reacting such functional groups with each other. As a combination of such functional groups, for example, a functional group having active hydrogen (hydroxyl group, amino group, thiol group, carboxyl group, etc.) and an epoxy group, a functional group having active hydrogen and an isocyanate group, and an ethylenically unsaturated group Ethylenically unsaturated group (polymerization of ethylenically unsaturated group occurs), silanol group and silanol group (condensation polymerization of silanol group occurs), silanol group and epoxy group, functional group having active hydrogen and functional group having active hydrogen Groups, active methylene and acryloyl groups, oxazoline groups and carboxyl groups. Further, the term “functional group that reacts with each other” here means that the reaction does not proceed only by mixing only the first component and the second component, but the polymerization initiator, curing agent, catalyst, and photosensitizer are combined. And those that react with each other by mixing.

  Examples of the polymerization initiator that can be used here include a photopolymerization initiator and a thermal polymerization initiator. Examples of the photopolymerization initiator include 2-hydroxy-2methyl-1phenyl-propan-1-one, 1- Hydroxy-cyclohexyl-phenyl-ketone, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one, 2,2-dimethoxy-1,2-diphenylethane-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1 and the like. Examples of the thermal polymerization initiator include azo thermal polymerization initiators such as azobisisobrityronitrile and peroxide thermal polymerization initiators such as benzoyl peroxide. Examples of the catalyst that can be used include an acid, a base catalyst, and a metal catalyst. Examples of the photosensitizer that can be used include benzophenone and derivatives thereof, thioxanthone and derivatives thereof, anthraquinone and derivatives thereof, and coumarin and derivatives thereof. Examples of the curing agent that can be used include a melamine curing agent, a (block) isocyanate curing agent, and an epoxy curing agent.

  When each of the first component and the second component has functional groups that react with each other, the mixture of the first component and the second component is thermosetting, photocurable (UV curable, visible light curable, infrared It has curability such as curability. Since thermosetting affects the thermoplastic resin as a substrate, a curing reaction that does not use heat, particularly a photocuring reaction, is preferred.

  As the difference in physical properties of the first component and the second component that cause phase separation between the first component and the second component, for example, the SP value (solubility parameter) of each component, SUH, LARKE, J. et al. P.S.A-1,5, 1671-1681 (1967)) and the weight average amount have a certain difference.

  When the difference between the physical properties of the first component and the second component that causes phase separation between the first component and the second component is the difference in SP value, the difference between the SP value of the first component and the SP value of the second component Is preferably 1.0 or more. The difference in SP value is more preferably 1.5 or more. The upper limit of the difference in SP value is not particularly limited, but is generally 8 or less. When the difference between the SP value of the first component and the SP value of the second component is 1.0 or more, the compatibility of the resins with each other is low, whereby the first component and the second component are applied after application of the curable resin composition A. It is believed that phase separation between the two components results.

  In the present invention, the first component resin is more preferably an unsaturated double bond-containing acrylic copolymer, and the second component monomer or oligomer is a polyfunctional unsaturated double bond-containing monomer or More preferably, it is the oligomer. Moreover, it is preferable that the curable resin composition A mainly contains these first component and second component. The “oligomer” as used in the present invention refers to a polymer having a repeating unit and having 3 to 10 repeating units. Further, the “main component” means that the proportion in the curable resin composition A is 60% by mass or more, preferably 70% by mass or more, and more preferably 80% by mass or more.

  Examples of such an unsaturated double bond-containing acrylic copolymer include a resin obtained by polymerizing or copolymerizing a (meth) acrylic monomer, and a (meth) acrylic monomer and another monomer having an ethylenically unsaturated double bond. Resin, a resin obtained by reacting a (meth) acrylic monomer with another ethylenically unsaturated double bond and a monomer having an epoxy group, a (meth) acrylic monomer and another ethylenically unsaturated double bond and an isocyanate group Examples thereof include a resin obtained by reacting a monomer having the same. One of these unsaturated double bond-containing acrylic copolymers may be used alone, or two or more thereof may be mixed and used.

  Examples of the polyfunctional unsaturated double bond-containing monomer include the above-mentioned polyfunctional monomers, for example, a dealcoholization reaction product of polyhydric alcohol and (meth) acrylate, specifically, dipentaerythritol hexa (meta). ) Acrylate, dipentaerythritol penta (meth) acrylate, trimethylolpropane tri (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, neopentyl glycol di (meth) acrylate, and the like. In addition, an acrylate monomer having a polyethylene glycol skeleton such as polyethylene glycol # 200 diacrylate (manufactured by Kyoeisha Chemical Co., Ltd.) can also be used. One of these polyfunctional unsaturated double bond-containing monomers may be used alone, or two or more thereof may be mixed and used.

  Furthermore, as another example of the first component and the second component useful in the present invention, it is preferable to use a resin in which both the first component and the second component contain a (meth) acrylic resin in a skeleton structure. The first component is more preferably an unsaturated double bond-containing acrylic copolymer, and the second component is more preferably a polyfunctional unsaturated double bond-containing monomer.

  In addition, as a preferable organic solvent used when the first component and the second component are the above combinations, for example, ketone solvents such as methyl ethyl ketone, acetone, methyl isobutyl ketone, cyclohexanone; methanol, ethanol, propanol, isopropanol, butanol And alcohol solvents such as anisole, phenetol propylene glycol monomethyl ether, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, and diethylene glycol diethyl ether. One of these solvents may be used alone, or two or more organic solvents may be mixed and used.

  The curable resin composition A in the present invention may contain a resin that is usually used in addition to the first component and the second component. Further, the curable resin composition A in the present invention can form a resin layer having irregularities without using fine particles or the like by using the first component and the second component as described above. There are features. Therefore, it is preferable that the curable resin composition in the present invention does not contain fine particles.

  The curable resin composition A in the present invention is prepared by mixing the first component and the second component together with a solvent, a polymerization initiator, a catalyst, a photosensitizer and a curing agent as necessary. . The mass ratio of the first component and the second component in the curable resin composition A is preferably 0.1: 99.9 to 50:50, more preferably 0.3: 99.7 to 20:80, 0.5: 99.5 to 10:90 is more preferable. In the case of using a polymerization initiator, a catalyst, and a photosensitizer, the first component and the second component, and 100 parts by mass of other resins as necessary (referred to collectively as “resin component”), 0.01 to 20 parts by mass, preferably 1 to 10 parts by mass can be added. When using a hardening | curing agent, 0.1-50 mass parts with respect to 100 mass parts of said resin components, Preferably 1-30 mass parts can be added. When using a solvent, it is 1-9,900 mass parts with respect to 100 mass parts of said resin components, Preferably it can add 10-900 mass parts.

  In addition, various additives can be added to the curable resin composition A in the present invention as necessary. Examples of such additives include conventional additives such as antistatic agents, plasticizers, surfactants, antioxidants, and ultraviolet absorbers.

  The curable resin composition of the present invention comprising as a main component the first component which is an unsaturated double bond-containing acrylic copolymer as described above and the second component which is a polyfunctional unsaturated double bond-containing monomer or oligomer thereof. Specific examples of the product A include Lucifural NAB-001, Lucifral NAB-007, and Lucifural NAG-1000, which are hard coat paints manufactured by Nippon Paint.

<Method for forming hard coat layer A>
The hard coat layer A in this invention is formed by apply | coating said curable resin composition A on a base film. The coating method of the curable resin composition A can be appropriately selected according to the situation such as the coating process, for example, dip coating method, air knife coating method, curtain coating method, roller coating method, wire bar coating method, gravure. It can be applied by a coating method or an extrusion coating method. Hereinafter, the coating liquid applied on the base film for forming the hard coat layer A may be referred to as a hard coat (HC) agent A.

  Such coating can be performed by diluting the curable resin composition A with an appropriate solvent, but such a solvent is not particularly limited. Specific examples of the solvent used include aromatic solvents such as toluene and xylene; ketone solvents such as methyl ethyl ketone, acetone, methyl isobutyl ketone and cyclohexanone; diethyl ether, isopropyl ether, tetrahydrofuran, dioxane, ethylene glycol dimethyl ether, Ether solvents such as ethylene glycol diethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, propylene glycol monomethyl ether, anisole, phenetol; ester solvents such as ethyl acetate, butyl acetate, isopropyl acetate, ethylene glycol diacetate; dimethylformamide, diethylformamide Amide solvents such as N-methylpyrrolidone; methyl cellosol , Ethyl cellosolve, cellosolve solvents such as butyl cellosolve; methanol, ethanol, alcohol solvents such as propanol; and the like; dichloromethane, halogenated solvents such as chloroform. These solvents may be used alone or in combination of two or more. Of these solvents, ester solvents, ether solvents, alcohol solvents and ketone solvents are preferably used.

  The phase separation of the first component and the second component may be performed by subjecting the coating film obtained by applying the curable resin composition A to the base film to phase separation at room temperature or before curing. The membrane may be dried and phase separated prior to curing. In the case of drying or heating before curing the coating film, it is dried at 30 to 200 ° C., more preferably 40 to 150 ° C. for 0.01 to 30 minutes, more preferably 0.1 to 10 minutes. Can be separated. When the mixture of the first component and the second component is photo-curable, drying before curing and phase separation in advance can effectively remove the solvent in the film having irregularities and is desirable. There is an advantage that unevenness of the size can be provided.

As another method of phase separation before curing, a method of irradiating the coating film with light and causing phase separation can also be used. As light to irradiate, for example, light having an exposure amount of 0.1 to 3.5 J / cm ² , preferably 0.5 to 1.5 J / cm ² can be used. The wavelength of the irradiation light is not particularly limited, and for example, irradiation light having a wavelength of 360 nm or less can be used. For example, when 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one or the like is used as a photoinitiator, the irradiation light is irradiated with light having a wavelength near 310 nm. And it is more preferable to irradiate light having a wavelength near 360 nm. Such light can be obtained using a high-pressure mercury lamp, an ultra-high pressure mercury lamp, or the like. By irradiating light in this way, phase separation and curing will occur. By irradiating light to cause phase separation, there is an advantage that unevenness of the surface shape due to drying unevenness of the solvent contained in the curable resin composition A can be avoided.

  By curing the coating film obtained by applying the curable resin composition A or the dried coating film, the hard coat layer A having unevenness formed by phase separation is formed. When the mixture of the first component and the second component is thermosetting, heating at 40 to 280 ° C, more preferably 80 to 250 ° C, for 0.1 to 180 minutes, more preferably 1 to 60 minutes. Can be cured. When the mixture of a 1st component and a 2nd component is photocurable, it can be hardened by irradiating light using the light source which emits the light of the wavelength as needed. Light irradiation can also be used for the purpose of phase separation as described above.

<Hard coat layer B>
The hard coat layer B in the present invention is a layer on which the surface of this layer is subjected to processing such as vapor deposition or printing when the hard coat film of the present invention is used for a touch panel, particularly for an icon sheet. The hard coat film of the present invention is later cut by punching, but if the thickness of the hard coat layer B is too thick, cracks occur in the hard coat layer near the cut portion during the punching process, resulting in poor design. . For this reason, the upper limit of the thickness of the hard coat layer B is 2.5 μm or less, preferably 2 μm or less, and more preferably 1.5 μm or less. On the other hand, the lower limit is 0.05 μm or more, and if it is too thin, the scratch resistance is inferior and the yield is lowered. From such a viewpoint, the lower limit of the thickness of the hard coat layer B is preferably 0.1 μm or more.
In addition, the thickness of the hard coat layer B can be easily adjusted by the application amount of the curable resin B described later constituting the hard coat layer B.

The hard coat layer B is provided for the purpose of imparting scratch resistance in the process. From such a viewpoint, the hardness is preferably B or more, more preferably HB or more. More preferably, it may be F or more. On the other hand, H or less is preferable from the viewpoint of increasing the punching workability improving effect, increasing the vapor deposition property or printability, or increasing the adhesion between the hard coat layer B and the vapor deposition layer or the print layer. . From the viewpoint of excellent balance, the hardness of the hard coat layer B is preferably HB to H.
In addition, the hardness of the hard coat layer B is appropriately selected from the curable resin B described later constituting the hard coat layer, the thickness of the hard coat layer B is adjusted, the addition amount of the photopolymerization initiator, and the UV irradiation. It can be easily adjusted by adjusting the intensity or adjusting the oxygen concentration by purging with N ₂ during UV irradiation.

In the present invention, the thickness of the hard coat layer A and the thickness of the hard coat layer B are in the above numerical ranges, and the thickness of the hard coat layer A is greater than the thickness of the hard coat layer B. 5 μm or more. By making the difference in thickness within the above numerical range, it is possible to suppress the occurrence of cracks at the edge portion during punching. If the difference in thickness is too small, cracks tend to occur. From such a viewpoint, the difference in thickness is preferably 1 μm or more, more preferably 3 μm or more, and particularly preferably 4 μm or more. On the other hand, if the difference in thickness is large, there is a tendency that cracks are less likely to occur, but if the difference in thickness is too large, the hard coat film tends to curl, so 9 μm or less is preferable, 6 μm or less is more preferable.
In the present invention, the hard coat layer B as described above can be formed by using, for example, the following curable resin B.

<Curable resin B>
The hard coat layer B in the present invention is made of a curable resin B as a main component. Examples of the curable resin B include a thermosetting resin and a radiation curable resin. In the present invention, a radiation curable resin is preferable, and an ultraviolet curable resin is particularly preferable. The hard coat layer B in the present invention is preferably composed of the following radiation curable resin B as a main component. Here, “main” means 51 mass% or more, preferably 55 mass% based on the mass of the hard coat layer.

The radiation curable resin B in the present invention is a monomer, oligomer, or polymer that can be cured by radiation. As the radiation curable resin B in the present invention, the crosslinking density after curing can be increased, the effect of improving the surface hardness can be increased, and the effect of improving the transparency can be increased. Polyfunctional (meth) acrylate compounds such as polyfunctional (meth) acrylate monomers, polyfunctional (meth) acrylate oligomers, or polyfunctional (meth) acrylate polymers are preferred.
Such a polyfunctional (meth) acrylate compound is a compound containing a (meth) acryloyl group in the molecule, and preferably contains at least two (meth) acryloyl groups in the molecule. As a result, the crosslinking reaction of the radiation curable resin B easily proceeds, and the effect of improving the surface hardness can be further increased. Moreover, the polyfunctional (meth) acrylate compound in this invention may contain other polymerizable functional groups other than a (meth) acryloyl group in a molecule | numerator.

  Specific examples of the polyfunctional (meth) acrylate compound containing at least two (meth) acryloyl groups in the molecule include, for example, neopentyl glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri ( (Meth) acrylate, trimethylolethane tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol tetra (meth) acrylate, alkyl-modified dipentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, Alkyl modified dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, caprolactone modified dipentaerythritol hexa Examples include (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, melamine (meth) acrylate, and the like, oligomers of about 2 to 20 mer composed of at least one of these, and polymers composed of at least one of these. be able to. Such polyfunctional (meth) acrylate compounds may be used alone or in combination of two or more.

  The number of repeating units of the polyfunctional (meth) acryl oligomer / polymer is not particularly limited, but for example, the number average molecular weight is preferably 150 to 1,000,000, and preferably 1,000 to 500,000. The effect of improving the appearance can be increased. When the number average molecular weight is less than 150 or exceeds 1,000,000, the viscosity tends to be too low or too high, and the effect of improving the coating appearance tends to be low.

  Polyfunctional (meth) acrylate compounds containing at least two (meth) acryloyl groups in the molecule as described above are, for example, Aronics M-400, M-450, M-305, M-309, M-310, M-315, M-320, TO-1200, TO-1231, TO-595, TO-756 (above, manufactured by Toagosei Co., Ltd.), KAYARD D-310, D-330, DPHA, DPHA-2C (above, Japan) Available from Kayaku Co., Ltd.) and Nikalac MX-302 (manufactured by Sanwa Chemical Co., Ltd.).

<Photopolymerization initiator>
In the present invention, the hard coat layer A and / or B having higher hardness (when referring to the hard coat layer A and / or B, these may be collectively referred to simply as a hard coat layer) is formed. Therefore, it is preferable to add a photopolymerization initiator to the hard coat layer. Examples of the photopolymerization initiator include 1-hydroxycyclohexyl phenyl ketone, 2,2-dimethoxy-2-phenylacetophenone, xanthone, fluorenone, anthraquinone, benzaldehyde, fluorene, anthraquinone, triphenylamine, carbazole, 3-methylacetophenone, 4- Chlorobenzophenone, 2,2-dimethoxy-2-phenylacetophenone, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholino-propan-1-one, 2,4,6-trimethylbenzoyldiphenyl Examples thereof include phosphine oxide and bis (2,6-dimethoxybenzoyl) -2,4,4-trimethylpentylphosphine oxide. It is preferable that the addition amount of this photoinitiator is 0.1 to 10 mass% on the basis of 100 mass% of curable resin (curable resin composition A or curable resin B). By making addition amount into the said numerical range, the improvement effect of the surface hardness of a hard-coat layer can be made higher. When there is too much addition amount, the added photoinitiator tends to work as a plasticizer, and there exists a possibility that the intensity | strength of a hard-coat layer may become low.

<Inert particles>
The hard coat layer B in the present invention can contain inert particles from the viewpoint of handleability. On the other hand, it is preferable not to contain from a transparency viewpoint.
Such inert particles may be organic particles or inorganic particles. Examples of the organic particles include polymer resin particles such as polystyrene resin particles, silicone resin particles, acrylic resin particles, styrene-acrylic resin particles, divinylbenzene-acrylic resin particles, polyester resin particles, polyimide resin particles, and melamine resin particles. It is done. Among these, acrylic resin particles are preferable from the viewpoint of excellent transparency. Examples of the inorganic particles include (1) silicon dioxide (including hydrate, silica sand, quartz, etc.); (2) alumina in various crystal forms; (3) silicic acid containing 30% by mass or more of SiO ₂ component. Salts (eg, amorphous or crystalline clay minerals, aluminosilicates (including calcined products and hydrates), warm asbestos, zircon, fly ash, etc.); (4) oxides of Mg, Zn, Zr and Ti; (5) Sulfates of Ca and Ba; (6) Phosphates of Li, Ba and Ca (including monohydrogen and dihydrogen salts); (7) Benzoates of Li, Na and K; (8) Terephthalate of Ca, Ba, Zn and Mn; (9) titanate of Mg, Ca, Ba, Zn, Cd, Pb, Sr, Mn, Fe, Co and Ni; (10) chromic acid of Ba and Pb Salt; (11) carbon (eg carbon black, (12) glass (for example, glass powder, glass beads, etc.); (13) carbonates of Ca and Mg; (14) fluorite; (15) spinel oxide. Of these, silicon dioxide is preferable from the viewpoint of excellent transparency.

In addition, it is preferable that the average particle diameter of an inert particle is 50-500 nm. When the average particle size is in the above numerical range, the blocking resistance is excellent. From such a viewpoint, the average particle diameter is more preferably 70 to 350 nm, and particularly preferably 80 to 280 nm.
Moreover, it is preferable that content of an inert particle is 2-10 mass% on the basis of the mass of the hard-coat layer B. As shown in FIG. When the content is in the above numerical range, the handleability is excellent while maintaining the transparency to some extent. From such a viewpoint, the content is more preferably 2 to 8% by mass, particularly preferably 3 to 6% by mass, but as described above, from the viewpoint of improving the transparency, the embodiment does not contain inert particles. Is preferred.

<Other components that can be added>
The hard coat layer B in the present invention is an inorganic fine particle or organic fine particle other than the above inert particles, a photosensitizer, a leveling agent, a plasticizer, an ultraviolet absorber, an antioxidant, as long as the object of the present invention is not impaired. An antistatic agent, a pigment, a dye, and the like can be contained.

<Method for forming hard coat layer B>
For the hard coat layer B, a coating liquid for forming the hard coat layer B (hereinafter sometimes referred to as a hard coat (HC) agent B) is desired to form the hard coat layer B of the base film described later. It can be obtained by coating on the surface on the side, drying by heating and curing.
The HC agent B in the present invention is a solution obtained by adding and mixing a curable resin B and an optional photopolymerization initiator, inert particles, and other components that can be added to a solvent. When adding each component, it may be added as a solid such as a powder, or a solid in a form of a solution or a dispersion using an appropriate solvent may be added. The solvent used for the HC agent B is not particularly limited. For example, ketones such as methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone, alcohols such as methanol, ethanol, propanol, n-butanol, secondary butanol and isopropyl alcohol, butyl acetate , Esters such as ethyl acetate, aromatic hydrocarbons such as toluene and xylene, glycol ethers such as propylene glycol monomethyl ether and propylene glycol monomethyl ether acetate can be used, and the dispersibility of HC agent B is improved. The appearance of the hard coat layer B is improved. Of these, ketones are preferable from the viewpoint of good solubility, and methyl ethyl ketone and methyl isobutyl ketone are particularly preferable. As solid content concentration of HC agent B, 1-70 mass% is preferable, and 10-60 mass% is more preferable, By setting it as such an aspect, defects, such as a smear, can be reduced.

As a method for applying the HC agent B, a method known per se can be adopted. For example, the lip direct method, comma coater method, slit reverse method, die coater method, gravure roll coater method, blade coater method, spray coater method, air knife coat method, dip coat method, bar coater method and the like can be preferably mentioned. By these coating methods, the HC agent B is coated on the base film to form a hard coat (HC) coating film, and the obtained HC coating film is heated and dried. As conditions for heat drying, it is preferable to heat at 50 to 150 ° C. for 10 to 180 seconds, more preferably to heat at 50 to 120 ° C. for 20 to 150 seconds, and to heat at 50 to 80 ° C. for 30 to 120 seconds. Is particularly preferred. After heat drying, the HC coating is cured by ultraviolet irradiation or electron beam irradiation. For UV irradiation, the irradiation amount is preferably 10 to 2,000 mJ / cm ^2, more preferably 50~1,500mJ / cm ^2, particularly preferably a 100~1,000mJ / cm ^2.

  The hard coat film of the present invention has a hard coat layer A and a hard coat layer B on both sides of the base film, but each hard coat layer may be provided in sequence, or both sides of the HC agent. You may apply A and HC agent B and provide a hard-coat layer simultaneously.

<Base film>
The base film in the present invention is not particularly limited. For example, a sheet or film made of polyethylene terephthalate, polyethylene naphthalate, polycarbonate, polyethylene, styrene resin (for example, polystyrene), triacetyl cellulose, acrylic resin, or the like is used. Can be mentioned. Of these, a film made of polyethylene terephthalate or polyethylene naphthalate is preferable from the viewpoint of good balance between optical properties such as transparency, mechanical properties, heat resistance, and price.
The thickness of the base film is not particularly limited, but is preferably 25 μm or more and 300 μm or less, more preferably 40 μm or more and 200 μm or less, and particularly preferably 50 μm or more from the viewpoint of rigidity suitable for a touch panel and good handling properties. 150 μm or less.

<Easily adhesive layer>
In this invention, it is preferable to have an easily bonding layer between the base film and the hard coat layer A and / or the hard coat layer B. Such an easy-adhesion layer contains a polyester resin and a crosslinking agent as constituent components. Such an easy-adhesion layer can further improve the adhesion between the base film and the hard coat layer. Moreover, by having an easy-adhesion layer on a base material film, the slipperiness | lubricity, scratch resistance, and blocking resistance of a base film can be improved more.
Hereinafter, each component which comprises an easily bonding layer is demonstrated.

<Polyester resin>
As the polyester resin used for the easy-adhesion layer, a polyester obtained from a dicarboxylic acid component and a diol component can be used. Examples of the polyvalent base component include terephthalic acid, isophthalic acid, phthalic acid, phthalic anhydride, 2,6-naphthalenedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, adipic acid, sebacic acid, trimellitic acid, pyromellitic acid, A dimer acid and 5-sodium sulfo isophthalic acid can be illustrated.
As such a polyester resin, it is preferable to use a copolymer polyester using two or more kinds of dicarboxylic acid components. The polyester resin may contain an unsaturated polybasic acid component such as maleic acid or itaconic acid, or a hydroxycarboxylic acid component such as p-hydroxybenzoic acid, if it is in a slight amount.

  Examples of the diol component of the polyester resin include ethylene glycol, 1,4-butanediol, diethylene glycol, dipropylene glycol, 1,6-hexanediol, 1,4-cyclohexanedimethanol, xylene glycol, dimethylolpropane, and the like ( Examples thereof include ethylene oxide) glycol and poly (tetramethylene oxide) glycol.

  The polyester resin preferably has a glass transition temperature of 40 to 100 ° C. When the glass transition temperature is lower than 40 ° C, blocking tends to occur between the films. When the glass transition temperature exceeds 100 ° C, the easily adhesive layer tends to be hard and brittle, and the scratch resistance tends to deteriorate. Absent. The glass transition temperature is more preferably 60 to 80 ° C. Within this range, better adhesion and scratch resistance can be obtained.

The intrinsic viscosity (measured in o-chlorophenol at 35 ° C.) of the polyester resin is preferably 0.4 dl / g or more and less than 0.7 dl / g. When the intrinsic viscosity is less than 0.4 dl / g, the low molecular weight product tends to be easily generated from the polyester resin itself, and the transparency of the substrate tends to be deteriorated. The intrinsic viscosity is preferably 0.5 dl / g or more and less than 0.7 dl / g. If it is this range, since the generation | occurrence | production of the low molecular weight substance from polyester resin itself can be suppressed more highly more highly and the cohesion force of polyester resin becomes higher, more excellent adhesiveness and scratch resistance can be obtained.
The polyester resin is preferably soluble or dispersible in water, but water-soluble one containing some organic solvent can also be used.

  The polyester resin can be produced, for example, by the following method. A dicarboxylic acid component and a diol component are charged into a transesterification reactor, a catalyst is added, methanol is distilled off by controlling the temperature at 230 ° C. in a nitrogen atmosphere, and a transesterification reaction is performed. Next, the temperature is gradually raised to 255 ° C., and the polycondensation reaction is carried out under reduced pressure in the system to obtain a polyester resin. When the molecular weight increases during the polycondensation, the melt viscosity increases and stirring in the system becomes difficult. The polyester resin used in the easy-adhesion layer has a high melt viscosity for a low molecular weight compared to homopolyethylene terephthalate, making stirring in the system very difficult, increasing the torque of the motor of the stirring equipment, and the shape of the blade Intrinsic viscosity can be increased by devising the above and by extending the polymerization time. The content ratio of the polyester resin in 100% by mass of the easy-adhesion layer is preferably 50 to 95% by mass, and more preferably 60 to 90% by mass.

<Crosslinking agent>
As a crosslinking agent used for an easily bonding layer, an epoxy type crosslinking agent, an oxazoline type crosslinking agent, a melamine type crosslinking agent, and an isocyanate type crosslinking agent are preferable. One of these may be used, or two or more may be used.

  Examples of the epoxy-based crosslinking agent include polyepoxy compounds, diepoxy compounds, monoepoxy compounds, glycidylamine compounds and the like. Here, examples of the polyepoxy compound include sorbitol, polyglycidyl ether, polyglycerol polyglycidyl ether, pentaerythritol polyglycidyl ether, diglycerol polyglycidyl ether, triglycidyl tris (2-hydroxyethyl) isocyanate, glycerol polyglycidyl ether. , Trimethylolpropane polyglycidyl ether, diepoxy compound, for example, neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, resorcin diglycidyl ether, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene Glycol diglycidyl ether, polypropylene glycol diglycidyl ether Ether, polytetramethylene glycol diglycidyl ether, as a monoepoxy compound, e.g., allyl glycidyl ether, 2-ethylhexyl glycidyl ether, phenyl glycidyl ether. Examples of the glycidylamine compound include N, N, N ′, N ′,-tetraglycidyl-m-xylylenediamine, 1,3-bis (N, N-diglycidylamino) cyclohexane and the like.

  As the oxazoline-based crosslinking agent, a polymer containing an oxazoline group is preferable. Such a polymer can be prepared by polymerization of an addition polymerizable oxazoline group-containing monomer alone or with another monomer. Addition polymerizable oxazoline group-containing monomers include 2-vinyl-2-oxazoline, 2-vinyl-4-methyl-2-oxazoline, 2-vinyl-5-methyl-2-oxazoline, 2-isopropenyl-2-oxazoline, 2-isopropenyl-4-methyl-2-oxazoline, 2-isopropenyl-5-ethyl-2-oxazoline, and the like can be mentioned, and one or a mixture of two or more thereof can be used. Among these, 2-isopropenyl-2-oxazoline is industrially easily available and suitable, and a polymer containing this as a monomer component, that is, an acrylic resin containing an oxazoline group is particularly adhesive in the present invention. Can be increased, which is preferable. Such a polymer preferably contains 1 to 10 (mmol / g, solid) of 2-isopropenyl-2-oxazoline. The other monomer is not particularly limited as long as it is a monomer copolymerizable with an addition-polymerizable oxazoline group-containing monomer, such as alkyl acrylate, alkyl methacrylate (the alkyl group includes a methyl group, an ethyl group, an n-propyl group, an isopropyl group). , N-butyl group, isobutyl group, t-butyl group, 2-ethylhexyl group, cyclohexyl group) and the like (meth) acrylic acid esters; acrylic acid, methacrylic acid, itaconic acid, maleic acid, fumaric acid, crotonic acid, Unsaturated carboxylic acids such as styrenesulfonic acid and its salts (sodium salt, potassium salt, ammonium salt, tertiary amine salt, etc.); Unsaturated nitriles such as acrylonitrile, methacrylonitrile; acrylamide, methacrylamide, N-alkyl Acrylamide, N-alkyl methacrylate Amide, N, N-dialkylacrylamide, N, N-dialkylmethacrylate (alkyl groups include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, t-butyl, 2- Unsaturated amides such as ethylhexyl group, cyclohexyl group, etc .; Vinyl esters such as vinyl acetate, vinyl propionate, acrylic acid, methacrylic acid added with polyalkylene oxide; methyl vinyl ether, ethyl vinyl ether, etc. Vinyl ethers; α-olefins such as ethylene and propylene; halogen-containing α and β-unsaturated monomers such as vinyl chloride, vinylidene chloride and vinyl fluoride; α, β-unsaturated such as styrene and α-methylstyrene Saturated aromatic monomers and the like, and one of these or It can be used two or more monomers.

  As the melamine-based crosslinking agent, a compound obtained by reacting methyl alcohol melamine derivative obtained by condensing melamine and formaldehyde with methyl alcohol, ethyl alcohol, isopropyl alcohol or the like as a lower alcohol and a mixture thereof are preferable. Examples of the methylol melamine derivative include monomethylol melamine, dimethylol melamine, trimethylol melamine, tetramethylol melamine, pentamethylol melamine, hexamethylol melamine and the like.

  Examples of the isocyanate-based crosslinking agent include tolylene diisocyanate, diphenylmethane-4,4′-diisocyanate, metaxylylene diisocyanate, hexamethylene-1,6-diisocyanate, 1,6-diisocyanate hexane, tolylene diisocyanate and hexanetriol. Adduct, adduct of tolylene diisocyanate and trimethylolpropane, polyol-modified diphenylmethane-4,4'-diisocyanate, carbodiimide-modified diphenylmethane-4,4'-diisocyanate, isophorone diisocyanate, 1,5-naphthalene diisocyanate, 3,3 ' -Bitrylene-4,4 'diisocyanate, 3,3' dimethyldiphenylmethane-4,4'-diisocyanate, metaphenylene diisocyanate, etc. It is.

The content of the crosslinking agent in the easy-adhesion layer is preferably 0.1 to 30% by mass, more preferably 1 to 20% by mass, and particularly preferably 3 to 10% by mass in 100% by mass of the easy-adhesion layer. When the content ratio is less than 0.1% by mass, the effect of increasing the cohesive force of the easy-adhesion layer tends to be difficult to develop, and the adhesiveness tends to be insufficient, which is not preferable. On the other hand, if the amount is more than 30% by mass, the easy-adhesion layer tends to be too hard, stress relaxation tends to be less, the effect of improving adhesiveness is less likely to be exhibited, and the film having the easy-adhesion layer is recovered and used. In such a case, foreign matter due to the crosslinked body tends to be generated, which is not preferable.
Of the above, the oxazoline-based crosslinking agent is preferable because it is easy to handle and the pot life of the coating solution is long.

<Fine particles>
The easy-adhesion layer in the present invention preferably contains fine particles from the viewpoint of further improving the slipperiness and scratch resistance of the base film. Such fine particles have an average particle diameter of 20 to 200 nm, preferably 40 to 120 nm. If it is larger than 200 nm, the fine particles fall off easily, and if it is smaller than 20 nm, sufficient lubricity and scratch resistance may not be obtained. The fine particles are usually contained in the composition of the easy adhesion layer.
Examples of such fine particles include calcium carbonate, magnesium carbonate, calcium oxide, zinc oxide, magnesium oxide, silicon oxide, sodium silicate, aluminum hydroxide, iron oxide, zirconium oxide, barium sulfate, titanium oxide, tin oxide, and antimony trioxide. Inorganic fine particles such as carbon black and molybdenum disulfide; organic fine particles such as acrylic cross-linked polymer, styrene cross-linked polymer, silicone resin, fluororesin, benzoguanamine resin, phenol resin, and nylon resin can be used. One of these may be used, or two or more may be used.
The content of fine particles in the easy-adhesion layer is preferably 0.1 to 10% by mass and more preferably 1 to 5% by mass in 100% by mass of the easy-adhesion layer. If the content is less than 0.1% by mass, sufficient lubricity and scratch resistance tend to be difficult to obtain, and if it exceeds 10% by mass, the cohesive force of the coating tends to decrease and the adhesiveness deteriorates. It tends to be unfavorable.

<Aliphatic wax>
The easy adhesion layer preferably contains an aliphatic wax from the viewpoint of further improving the lubricity of the base film.

  Specific examples of the aliphatic wax include plant-based waxes such as carnauba wax, candelilla wax, rice wax, wood wax, jojoba oil, palm wax, rosin modified wax, cucumber wax, sugar cane wax, esparto wax, and bark wax. Animal waxes such as beeswax, lanolin, whale wax, ibota wax and shellac wax; mineral waxes such as montan wax, ozokerite and ceresin wax; petroleum waxes such as paraffin wax, microcrystalline wax and petrolactam; And synthetic hydrocarbon waxes such as polyethylene wax, oxidized polyethylene wax, polypropylene wax, and oxidized polypropylene wax. Among these, carnauba wax, paraffin wax, and polyethylene wax are particularly preferable because they are easy to adhere to hard coats and pressure-sensitive adhesives and have good lubricity. These are preferably used as an aqueous dispersion because of their ability to reduce environmental burden and ease of handling.

  The content of these aliphatic waxes in 100% by mass of the easy-adhesion layer is preferably 0.5 to 30% by mass, more preferably 1 to 10% by mass, and particularly preferably 2 to 5% by mass. If the content is less than 0.5% by mass, the film surface slipperiness tends to be insufficient, which is not preferable. On the other hand, when the content exceeds 30% by mass, the adhesion to the base film tends to be insufficient, and the adhesion to the hard coat layer tends to be insufficient, which is not preferable.

<Method for forming easy-adhesion layer>
In the present invention, each of the above components is a coating liquid (including an aqueous coating liquid such as an aqueous solution, an aqueous dispersion or an emulsified liquid. Hereinafter, it may be simply referred to as a coating liquid) for forming an easy adhesion layer. It is preferably used in the form. If necessary, the coating liquid may contain other resins than the above-described components, such as an antistatic agent, a colorant, a surfactant, an ultraviolet absorber, and a crosslinking agent.

  The solid content concentration of the coating liquid used in the present invention is usually preferably 20% by mass or less, and particularly preferably 1 to 10% by mass. If this ratio is less than 1% by mass, the coatability to the substrate film may be insufficient, while if it exceeds 20% by mass, the stability of the coating liquid and the appearance of the easy-adhesive layer may be deteriorated. Absent.

  Application of the coating liquid can be carried out at any stage, but so-called in-line coating, which is carried out during the production process of the base film, is preferred, and further, it is preferably applied to the film before orientation crystallization is completed. . Here, the film before the crystal orientation is completed is an unstretched film, a uniaxially stretched film obtained by stretching the unstretched film in either the longitudinal direction or the transverse direction, and further in two directions, the longitudinal direction and the transverse direction. It includes those stretched at a magnification (biaxially stretched film before being finally re-stretched in the machine direction or the transverse direction to complete oriented crystallization). Especially, it is preferable to apply | coat a coating liquid to an unstretched film or a uniaxially stretched film, and to perform longitudinal stretch and / or horizontal stretch and heat setting as it is.

  When applying the coating liquid to the base film, either a corona surface treatment, a flame treatment, a plasma treatment, or other physical treatment is applied to the surface of the base film as a pretreatment for improving the coating property, or the coating liquid is interfaced. It is preferred to add an activator. Such a surfactant improves the function of promoting the wetting of the coating liquid on the film and the stability of the coating liquid. For example, polyoxyethylene-fatty acid ester, sorbitan fatty acid ester, glycerin fatty acid ester, fatty acid metal soap And anionic and nonionic surfactants such as alkyl sulfates, alkyl sulfonates, and alkyl sulfosuccinates. The amount of the surfactant added is preferably 0.01 to 2% by mass in the coating solution.

  As a coating method, any known coating method can be applied. For example, a roll coating method, a gravure coating method, a roll brush method, a spray coating method, an air knife coating method, an impregnation method, a curtain coating method and the like can be used alone or in combination. In addition, a coating film may be formed only on one side of a film as needed, and may be formed on both surfaces.

  The thickness of the easy adhesion layer is a dry film thickness, preferably 0.01 to 0.3 μm, more preferably 0.02 to 0.25 μm, and still more preferably 0.05 to 0.1 μm. The coating amount is preferably such that the thickness of the easy-adhesion layer falls within the above numerical range. If the easy-adhesion layer is too thin, the adhesion tends to be inferior. Conversely, if it is too thick, blocking tends to occur or the haze value tends to increase.

<Characteristics of hard coat film>
The haze of the hard coat film of the present invention is preferably 2.0% or less, more preferably 1.5% or less, particularly preferably from the viewpoint of excellent visibility of the LCD when used as an optical application such as a touch panel. 1.2% or less. Such haze can be achieved by lowering the haze of the substrate film, or by appropriately adjusting the fine particles in the easy-adhesion layer, the components of the hard coat layer, and the mode of the inert particles to be added.

Hereinafter, the present invention will be described more specifically with reference to examples. In addition, each evaluation in an Example followed the following method.
(1) Haze The haze (Hz) of the hard coat film was measured with a haze meter HCM-2B manufactured by Suga Test Instruments Co., Ltd. according to JIS K7150. The measurement light was incident from the hard coat layer A side. Measurement was carried out at arbitrary five locations, and the average value thereof was defined as haze (Hz) (unit:%).
(2) Thickness of hard coat layer The sample film was cut with a sharp razor, and the thickness of the hard coat layer was measured by observing the obtained cross section with an optical microscope. The measurement was carried out at 10 arbitrary locations for each of the hard coat layer A and the hard coat layer B, and the average value of each was defined as the thickness (unit: μm) of the hard coat layer.
(3) Presence / absence of unevenness formed by phase separation of two or more components Using a non-contact surface shape measuring machine manufactured by Zygo, the surface of the hard coat layer A was observed, and phase separation of the two components, and The presence or absence of unevenness was observed. Rz of 25 nm or more was evaluated as “present” and less than 25 nm was evaluated as “none”.

(4) Pencil hardness It implemented based on JISK5600. (Load: 750g)
Evaluation was carried out on the surface of the hard coat layer of the hard coat film.
(5) Punchability (cutting)
The punchability of the hard coat film was determined by punching 100 sheets from a sample film into a size of 50 mm in length and 40 mm in width using a manual punching machine (PAT. NO. 1835841) manufactured by Yamakoshi Works. The four sides were visually observed to check for cracks. The number of cracks was determined as follows.
◎: 0 sheets ○: 1-2 sheets Δ: 3-4 sheets ×: 5 sheets or more Punching was performed with the hard coat layer A on the upper blade side.

(6) Pen sliding property Using a polyacetal pen with a tip of 0.8 mmR, the surface of the obtained hard coat film on the hard coat layer A side is linearly slid 50,000 times under the condition of a load of 250 g. Thereafter, the degree of abrasion of the hard coat surface was determined by visual observation and determined as follows.
◎: No scratch ○: It looks very thin, but there are shallow scratches that cannot be seen by touching with a finger.
(Triangle | delta): Although it looks thin, there is a crack of the grade which can be understood by touching with a finger.
X: There are scratches that can be clearly seen even if they are clearly visible and touched.
(7) Surface Roughness Using a non-contact optical roughness meter (manufactured by ZYGO, trade name: NewView 5022), scanning was performed on a region of 283 μm × 213 μm at a magnification of 25 times to obtain a surface profile. Centerline average roughness (Ra) and ten-point average roughness (Rz) were calculated from the obtained surface profile. The measurement was carried out at any five locations on the surface of the hard coat layer A, and the average value thereof was taken as the measurement value.

[Example 1]
Polyester film (type: O4L86W, thickness: 188 μm, polyester resin / crosslinking agent / fine particles / aliphatic wax = 90/5/2/3 (mass% of solid content) as a constituent component as a base film On one side of the polyester film having a 75 nm thick easy-adhesive layer on both sides (this side is the front side), as a curable resin composition A, a hard coat paint made by Nippon Paint (Luciferal NAB-001) Was applied by a reverse gravure coating method so that the coating thickness after drying was 6 μm, and dried under conditions of 60 ° C. × 2 minutes. Subsequently, the hard coat layer A was formed by irradiating ultraviolet rays under a condition of a light amount of 200 mJ / cm ² using an ultraviolet irradiation device (FusionUV Systems Japan Co., Ltd .: trade name Fusion H bulb).
Next, on the surface opposite to the surface on which the hard coat layer A is formed on the base film, a hard coat paint (Desolite Z7501, polyfunctional acrylate UV curable resin) manufactured by JSR Co., Ltd. as HC agent B is reverse gravure. The coating method was applied such that the coating thickness after drying was 1.5 μm, and dried under the conditions of 70 ° C. × 2 minutes. Next, similarly to the front surface, a hard coat layer B is formed by irradiating ultraviolet rays under the condition of a light amount of 200 mJ / cm ² using an ultraviolet irradiation device (FusionUV Systems Japan Co., Ltd .: product name Fusion H bulb). Then, a hard coat film was obtained. The properties of the obtained hard coat film are shown in Table 1.

[Example 2]
A hard coat film was obtained in the same manner as in Example 1 except that a hard coat paint (Luciferal NAB-007) manufactured by Nippon Paint Co., Ltd. was used as the curable resin composition A. The properties of the obtained hard coat film are shown in Table 1.

[Example 3]
A hard coat film was obtained in the same manner as in Example 1 except that the thickness of the hard coat layer B after drying was 0.5 μm. The properties of the obtained hard coat film are shown in Table 1.

[Example 4]
A hard coat film was obtained in the same manner as in Example 1 except that a hard coat paint (Luciferal NAG-1000) manufactured by Nippon Paint Co., Ltd. was used as the HC agent for forming the hard coat layer A. The properties of the obtained hard coat film are shown in Table 1.
[Examples 5 to 6]
A hard coat film was prepared and evaluated in the same manner as in Example 1 except that the coating amounts of the curable resin composition A and the HC agent B were changed and the thickness of the hard coat layer was as shown in Table 1. The results are shown in Table 1.

[Comparative Example 1]
A hard coat film was obtained in the same manner as in Example 1 except that a hard coat paint (Desolite Z7501) manufactured by JSR Corporation was used as the curable resin composition A for forming the hard coat layer A. It was necessary to wind up the obtained hard coat film after pasting a protective film (manufactured by Sanei Kaken, PAC-3-60) with a nip roll before winding. The properties of the obtained hard coat film are shown in Table 1.

[Comparative Example 2]
A hard coat film was obtained in the same manner as in Example 1 except that the thickness of the hard coat layer B after drying was 3 μm. The properties of the obtained hard coat film are shown in Table 1.

[Comparative Example 3]
A hard coat film was obtained in the same manner as in Example 1 except that the thickness of the hard coat layer B after drying was changed to 6 μm. The properties of the obtained hard coat film are shown in Table 1.

[Comparative Examples 4 to 7]
A hard coat film was prepared and evaluated in the same manner as in Example 1 except that the coating amounts of the curable resin composition A and the HC agent B were changed and the thickness of the hard coat layer was as shown in Table 1. The results are shown in Table 1.
In Examples 1 to 6 and Comparative Examples 2 to 7, it was possible to wind up without using a protective film, and there was no problem in windability, which was good.
In Table 1, HC layer A represents hard coat layer A.

  The hard coat film of the present invention is useful for touch panels of terminals such as ATMs, car navigation systems, smartphones, portable music playback terminals, and game machines.

Claims (6)

  A hard coat film having a hard coat layer A on one surface and a hard coat layer B on the other surface, wherein the thickness of the hard coat layer A is 2 μm or more and 10 μm or less, and the thickness of the hard coat layer B Is 0.05 μm or more and 2.5 μm or less, and the thickness of the hard coat layer A is 0.5 μm or more thicker than that of the hard coat layer B. The hard coat layer A is formed by phase separation of two or more components. Hard coat film having unevenness.   The hard coat film according to claim 1, wherein the hard coat layer A does not contain fine particles for imparting irregularities.   The hard coat according to claim 1, wherein the center line average roughness (Ra) of the surface of the hard coat layer A is 1 nm to 300 nm and the 10-point average roughness (Rz) is 25 nm to 2,000 nm. the film.   The hard of any one of Claims 1-3 which has an easily bonding layer which contains a polyester resin and a crosslinking agent as a structural component between a base film and the hard-coat layer A and / or the hard-coat layer B. Coat film.   The hard coat layer A is composed of a curable resin composition A, and the curable resin composition A includes an unsaturated double bond-containing acrylic copolymer as a first component and a polyfunctional unsaturated double as a second component. The hard coat film according to claim 1, comprising a bond-containing monomer or an oligomer thereof as a main component. The hard coat layer B is made of a curable resin B, and the curable resin B is mainly composed of a polyfunctional (meth) acrylate monomer, a polyfunctional (meth) acrylate oligomer, or a polyfunctional (meth) acrylate polymer. Item 6. The hard coat film according to any one of Items 1 to 5.