JP2013006312A - Hard coat film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hard coat film that hardly causes cracks in an edge portion during punching processing, even though being double-sided hard coat film, and also has superior fingerprint resistance.SOLUTION: The hard coat film has a hard coat layer A on one surface of a base material film, and a hard coat layer B on the other surface thereof, wherein the thickness of the hard coat layer A is ≥2 μm and ≤10 μm, the thickness of the hard coat layer B is ≥0.05 μm and ≤2.5 μm, the thickness of the hard coat layer A is ≥0.5 μm thicker than the thickness of the hard coat layer B, and a contact angle of water on the surface of the hard coat layer A is ≥78 degrees and ≤90 degrees and the contact angle of n-dodecane is ≤20 degrees.

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 fingerprint resistance, 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 used to improve the design of the plastic film that has been hard-coated on one side (front surface, the outer surface of the touch panel) on the opposite side (back side) of the hard-coated process. A plurality of sheets (about 10 to 30 sheets) from one processed sheet obtained by this series of processes such as vapor deposition processing, printing of frames and logos, and etching of vapor deposition parts other than printing parts The icon sheet is made and finally cut (punched) into the required size for use by touch panel manufacturers.

  By the way, as a use of such a touch panel, terminals such as ATM, a car navigation system, a smartphone, a portable music playback terminal, a game machine, and the like are various. As an input method to the touch panel, there are a case of inputting mainly with a human finger and a case of inputting with a plastic stylus pen depending on these applications. Among these, in finger input, there is a problem that fingerprints tend to remain on the touch panel surface. In order to solve such problems, Patent Documents 1 to 4 disclose techniques for using a surfactant in the hard coat layer or performing surface treatment with an alkaline aqueous solution.

On the other hand, touch panels for finger input are often used outdoors, such as a car navigation system, which is a typical application, and the image quality should be at a practical level, and there are demands such as low haze and clearness. not high. In such cases, antiglare (AG) -treated hard coat (HC) is used in most cases to prevent reflection of external light and reflection.
) A film is provided on the surface of the touch panel (for example, Patent Documents 5 and 6). And since such AGHC originally looks whitish, it is difficult to see fingerprints from the beginning. Therefore, the problem with fingerprints has not been considered so important.

JP 2004-114355 A JP 2004-230562 A JP 2005-186484 A JP 2009-40056 A JP 2007-58162 A JP 2008-96781 A Japanese Patent Laid-Open No. 10-16111

  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. However, in this case, the present inventors have newly found that there is a problem that cracks occur at the edge portion during punching.

  In recent years, a touch panel with low haze and high clearness has been required for a terminal intended to view an image or a video, such as a smartphone or a portable music playback terminal. In addition, due to the fact that various inputs are possible, for example, capacitive touch panels have been introduced in these applications, and those based on finger input have become mainstream. In this case, it is necessary to use a clear HC film without using an AGHC film in order to avoid a decrease in clearness. In this case, the surface of the clear HC film is touched with a finger, so that a fingerprint attached at the time of input is not present. There is a big problem that it becomes very noticeable. There is also a problem that the attached fingerprint is difficult to wipe off.

  Therefore, although the present invention is a double-sided hard coat film, cracks are hardly generated at the edge portion during punching, and it is not noticeable even when fingerprints are attached, and is excellent in wiping properties of fingerprints (hereinafter referred to as these). Are collectively referred to as fingerprint resistance.) An object is to provide a hard coat film.

  The present inventor has intensively studied to solve the above problems. As a result, with respect to the hard coat layers on the front and back sides, the respective thicknesses and thickness differences are in a specific numerical range, and the contact angles of water and n-dodecane on the front hard coat layer are in a specific numerical range. As a result, the inventors have found that cracks are less likely to occur during punching and have excellent fingerprint resistance, and have reached the present invention.

  That is, the present invention is a hard coat film having a hard coat layer A on one surface and a hard coat layer B on the other surface, and the hard coat layer A has a thickness of 2 μm or more and 10 μm or less. The thickness of the coat layer B is 0.05 μm or more and 2.5 μm or less, the thickness of the hard coat layer A is 0.5 μm or more thicker than the thickness of the hard coat layer B, and the contact angle of water on the surface of the hard coat layer A is The hard coat film has a contact angle of 78 ° to 90 ° and an n-dodecane contact angle of 20 ° or less.

  Moreover, this invention 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, and the hard-coat layer B is an average grain. 2 to 10% by mass of inert particles having a diameter of 50 to 500 nm based on the mass of the hard coat layer B, the contact angle of water on the surface of the hard coat layer B is 88 degrees or less, and the contact of n-dodecane By providing at least one of the aspects having an angle of 20 degrees or less, a further excellent hard coat film can be obtained.

  Although the present invention is a double-sided hard coat film, it is possible to provide a hard coat film that is less prone to crack at the edge portion during punching and has excellent fingerprint resistance.

<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 is such that the pencil hardness is H or more, preferably 2H or more, more preferably 3H or more, but the lower limit is 2 μm or more. . 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 by making the thickness of the hard-coat layer A into the said numerical range.

(Contact angle of hard coat layer A)
In the hard coat layer A in the present invention, the contact angle of water on the surface thereof is 78 degrees or more and 90 degrees or less, and the contact angle of n-dodecane is 20 degrees or less. When the contact angles of water and n-dodecane are in the above numerical range, the fingerprint resistance is excellent. That is, the oil content in the fingerprint (which is an alternative evaluation by n-dodecane in the present invention) can be more easily spread and the oil content in the fingerprint can be further suppressed from diffusing light and becoming noticeable white. As a result, fingerprints can be made less noticeable. At the same time, the wiping property of the attached fingerprint becomes better. When the contact angle of water is smaller than 78 degrees, the moisture / oil content tends to wet and spread, and the effect of improving the wiping property tends to decrease. On the other hand, if the contact angle of water is greater than 90 degrees, it may be difficult for moisture (cleaning liquid or water during wiping or wiping, moisture in the exhalation) to enter below oil, or wipe off the attached fingerprint. There is a tendency for the effect of improving the properties to be significantly reduced. In addition, when the contact angle of n-dodecane exceeds 20 degrees, the wetting and spreading of the oil in the fingerprint component tends to be insufficient, the light hitting the oil diffuses, and the fingerprint itself stands out white. It tends to be easier. From such a viewpoint, the contact angle on the surface of the hard coat layer A is more preferably a water contact angle of 78 degrees or more and 86 degrees or less, and a contact angle of n-dodecane of 15 degrees or less. More preferably, the contact angle is 80 ° to 85 °, and the contact angle of n-dodecane is 10 ° or less. In order to achieve such a numerical value range of the contact angle, for example, a method using a radiation curable resin A as described later can be exemplified, which is preferable in the present invention.

(Radiation curable resin A)
The hard coat layer A in the present invention is not particularly limited as long as it satisfies the contact angle of water and the contact angle of n-dodecane defined in the present invention. The radiation curable resin A may be used. Here, “mainly” means 80% by mass or more, preferably 90% by mass or more, based on the total mass of the hard coat layer.
In particular, in the present invention, use of the radiation curable resin A described later can be exemplified as a preferable method for satisfying the aspect of the contact angle defined by the present invention.

  As such a radiation curable resin A, a structure in which a (poly) alkylene glycol component is copolymerized in the main chain or side chain of an acrylic polymer composed of a polyfunctional (meth) acrylate compound in the radiation curable resin B described later is formed. It is preferable to use a radiation-curable resin containing a (poly) alkylene glycol component. The (poly) alkylene glycol component may be mono (alkylene glycol) without having a repeating structure, or may be oligo (alkylene glycol) or poly (alkylene glycol) having a repeating structure. . Specific examples of the (poly) alkylene glycol component include (poly) ethylene glycol and (poly) propylene glycol, and (poly) ethylene glycol is particularly preferred. A preferred embodiment of the (poly) alkylene glycol component-containing radiation curable resin includes an embodiment containing a compound having a (meth) acryloyl group as a functional group at both ends of the (poly) alkylene glycol component. Moreover, what can form the structure which the (poly) alkylene glycol component random-copolymerized to the polyfunctional (meth) acrylate compound (oligomer or polymer) after hardening, or the block copolymerization especially preferably is mentioned preferably.

  The (poly) alkylene glycol component has a number average molecular weight Mn of preferably 46 to 1,000,000, more preferably 60 to 500,000. When the number average molecular weight Mn is in the above numerical range, the contact angle of water and the contact angle of n-dodecane on the surface of the hard coat layer can be easily set within the numerical range defined by the present invention. When the number average molecular weight Mn is too high, the contact angle of water tends to be too high. Also, since the viscosity of the coating becomes too high, coating tends to be difficult. Moreover, since it tends to be difficult to dissolve in a solvent with low polarity, it tends to be difficult to handle as a coating agent.

  The copolymerization amount of the (poly) alkylene glycol component is preferably 1% by mass or more and 5% by mass or less, more preferably 1.5% by mass or more and 4% by mass with respect to the mass of the acrylic polymer composed of the polyfunctional (meth) acrylate compound. It is 2 mass% or less, Most preferably, it is 2 mass% or less and 3 mass% or less. When the copolymerization amount of the (poly) alkylene glycol component is in the above numerical range, the contact angle of water and the contact angle of n-dodecane on the surface of the hard coat layer A may be within the numerical range defined by the present invention. It becomes easy. Increasing the copolymerization amount of the (poly) alkylene glycol component tends to reduce the contact angle of water, but does not significantly affect the contact angle of n-dodecane. Therefore, according to the method using the (poly) alkylene glycol component, a combination of a contact angle range of water and a contact angle range of n-dodecane that cannot be obtained only by adding a normal surfactant can be obtained.

  The number average molecular weight Mn of the radiation curable resin A as described above is preferably 100 to 1000000, more preferably 1000 to 500000. When the number average molecular weight Mn is too high, since the viscosity is too high, coating tends to be difficult.

  Commercially available products can be used as the (poly) alkylene glycol component-containing radiation curable resin having the above-described embodiment. Examples of such commercially available products include KZ6404 (manufactured by JSR Corporation), Lucifral G-004 (Nippon Paint). Kogyo Co., Ltd.), Beam Set 1460 (Arakawa Chemical Industries Co., Ltd.) and the like.

  The inventor has found that adjustment of the contact angle as in the present invention cannot be achieved by simple addition of an independent additive such as a surfactant capable of adjusting wettability. That is, when a surfactant is added, the hydrophilic and hydrophobic groups of the surfactant are mixed on the hard coat layer surface after coating and curing, so that the wettability to water and oil (n-dodecane) At the same time, the wettability with respect to becomes worse. On the other hand, in a general acrylic hard coat layer to which no surfactant is added, the contact angle of n-dodecane tends to be low, but the contact angle of water tends to be too low. In any case, it was confirmed that a normal hard coat layer and a surfactant added thereto could not achieve the range of contact angles preferably defined by the present invention, that is, excellent fingerprint resistance could not be obtained. . On the other hand, in the method using the (poly) alkylene glycol component-containing radiation curable resin as described above, when the amount of copolymerization of the (poly) alkylene glycol component is increased, the water contact angle tends to decrease, but n -Does not significantly affect the contact angle of dodecane. Therefore, it is possible to simultaneously achieve the water contact angle and the n-dodecane contact angle 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.

  The hard coat layer B is provided for the purpose of imparting scratch resistance in the process. From such a viewpoint, the hardness may be preferably B or more, more preferably HB or more. And more preferably 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 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.

(Radiation curable resin B)
The hard coat layer B in the present invention is made of a curable resin as a main component. Examples of the curable resin 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% by mass or more, preferably 55% by mass or more 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 A 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 (Meth) acrylate, ditrimethylolpropane tetra (meth) acrylate), melamine (meth) acrylate, etc., and oligomers of about 2 to 20 mer composed of at least one of these, and polymers composed of at least one of these. Can be mentioned. 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. For example, the number average molecular weight is preferably 150 to 1,000,000, preferably 1,000 to 500,000, and the effect of improving the coating appearance is enhanced. Can do. 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), KAYARD D-310, D-330, DPHA, DPHA-2C (above, Nipponization) Such as Nikarac MX-302 (manufactured by Sanwa Chemical Co., Ltd.).

(Contact angle of hard coat layer B)
Further, the hard coat layer B in the present invention preferably has a contact angle of water of 88 degrees or less on the surface thereof and a contact angle of n-dodecane of 20 degrees or less. When the contact angle of water and n-dodecane is in the above numerical range, the adhesion to vapor deposition and printing is excellent. From this point of view, the contact angle on the surface of the hard coat layer B is more preferably a water contact angle of 86 degrees or less and an n-dodecane contact angle of 15 degrees or less. Is more preferably 85 degrees or less and the contact angle of n-dodecane is 10 degrees or less. In order to achieve such a numerical range of the contact angle, for example, a method using the above-described radiation curable resin A can be exemplified, which is preferable in the present invention. In this case, the radiation curable resin A may be 80% by mass or more, preferably 90% by mass or more in the total mass of the hard coat layer B.

  The adjustment of the contact angle on the surface of the hard coat layer B is also achieved by simple addition of an independent additive such as a surfactant capable of adjusting the wettability as well as the adjustment of the contact angle of the surface of the hard coat layer A. Can not. Therefore, the normal hard coat layer and those to which a surfactant is added cannot achieve the range of the contact angle on the surface of the hard coat layer B preferably defined by the present invention, that is, excellent adhesiveness cannot be obtained. .

(Photopolymerization initiator)
In the present invention, the hard coat layer A and / or B having higher hardness (hereinafter, when referring to the hard coat layer A and / or B, these may be collectively referred to as a hard coat layer). In order to form it, 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-1-1 [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. 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 in the present invention can contain inert particles.
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; Ba and Pb chromate; (11) carbon (eg Kerr Bon black, graphite, etc.); (12) Glass (for example, glass powder, glass beads, etc.); (13) Carbonate of Ca and Mg; (14) Fluorite; (15) Spinel oxide. Of these, silicon dioxide is preferable from the viewpoint of excellent transparency.

The average particle size of the inert particles is preferably 50 to 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 a hard-coat layer. When the content is in the above numerical range, the blocking resistance is excellent. From such a viewpoint, the content is more preferably 2 to 8% by mass, and particularly preferably 3 to 6% by mass.

  In the present invention, it is preferred that the hard coat layer B contains such inert particles, and it is difficult to cause blocking when the hard coat film of the present invention is wound while maintaining a good appearance. be able to. By doing so, it is possible to wind up without using a protective film or the like. In this case, it is preferable from the viewpoint of transparency that the hard coat layer A substantially does not contain inert particles.

(Other components that can be added)
The hard coat layer 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, an electrification, and the like within the range not impairing the object of the present invention. Inhibitors, pigments, dyes and the like can be contained.

<Method for forming hard coat layer>
The hard coat film of the present invention has a coating liquid for forming a hard coat layer (hereinafter sometimes referred to as a hard coat (HC) agent) on the side on which the hard coat layer of the base film to be described later is formed. It can be obtained by coating on the surface of the film, drying by heating and curing.

  The HC agent in the present invention is a solution in which a curable resin, a photopolymerization initiator that may be optionally added, inert particles, and other components that can be added are added to a solvent and mixed. In adding each component, it may be added as a solid such as powder, or a solid or a dispersion in a single form using an appropriate solvent may be added. The solvent used for the HC agent 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 the HC agent is improved. The appearance of the coat layer 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, 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, 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, an HC agent 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 2000 mJ / cm ^2, more preferably 50~1500mJ / cm ^2, particularly preferably a 100~1000mJ / cm ^2.

  The hard coat film of the present invention has a hard coat layer on both sides of the base film, but each hard coat layer may be provided sequentially, or an HC agent is coated on both sides and simultaneously the hard coat layer. May be provided.

<Base film>
The base film in this invention is not specifically limited, For example, the sheet | seat or film which consists of a polyethylene terephthalate, a polyethylene naphthalate, a polycarbonate, polyethylene, a polystyrene triacetyl cellulose, an acryl etc. 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, 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 poly ( 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 of the polyester resin is preferably 0.4 or more and less than 0.7. If the intrinsic viscosity is less than 0.4, low molecular weight substances are likely to be generated from the polyester resin itself, and the transparency of the substrate tends to be deteriorated. The intrinsic viscosity is preferably 0.5 or more and less than 0.7. 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 that can be copolymerized with an addition-polymerizable oxazoline group-containing monomer. , 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 styrene sulfonic 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 ' -Bitrilene-4,4 'diisocyanate, 3,3' dimethyldiphenylmethane-4,4'-diisocyanate, metaphenylene diisocyanate, etc. That.

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, and if it exceeds 20% by mass, the stability of the coating liquid and the appearance of the easy-adhesive layer may be deteriorated. .

  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. The film is stretched at a magnification (a biaxially stretched film before it is finally re-stretched in the machine direction or the transverse direction to complete orientation crystallization), and the like. 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 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, that is, the coating amount of the coating liquid is The 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 5% or less, more preferably 3% or less, and particularly preferably 1% or less from the viewpoint of excellent visibility of the LCD when used as an optical application such as a touch panel. is there. 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) 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.

(4) 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.

(5) Contact angle (5-1) Contact angle of water 0.2 mL of distilled water is slowly dropped from a height of 5 mm onto the surface of the hard coat layer with a syringe and left for 30 seconds, then the contact angle (hard coat The angle formed by the tangent line between the surface of the layer and the droplet) was measured by observing with a CCD camera. The same operation was repeated 5 times, and the average value was used.
(5-2) Contact angle of n-dodecane From the height of 5 mm, 0.2 mL of n-dodecane was slowly dropped onto the hard coat layer surface with a syringe and allowed to stand for 15 seconds. And the angle formed by the tangent line of the droplet) were measured by observing with a CCD camera. The same operation was repeated 5 times, and the average value was used. In the region where the contact angle is 5 degrees or less, since the numerical value of the contact angle cannot be obtained accurately, the measured value was obtained with the result that the contact angle was 5 degrees or less.

(6) Adhesive evaluation Aluminum was vapor-deposited on the surface of the hard-coat layer B (thickness was about 20-30 nm) using the vacuum evaporation apparatus (model number: JEE-4X) by JEOL Ltd., and the hard coat was carried out. The surface of layer A was fixed to a glass plate with double-sided tape. Next, cello tape (registered trademark) is bonded to the surface of the hard coat layer B on which aluminum is vapor-deposited, and after 1 minute, it is quickly peeled off in the vertical direction. At that time, the degree of aluminum remaining on the surface of the hard coat layer B is determined by the following index.
(Double-circle): There is no peeling of an aluminum vapor deposition layer.
○: The degree to which the deposited aluminum layer is peeled off a little. (Guideline: 1-5%)
X: Partially peeled off. (Guideline: 5-50%)
Xx: The part which stuck the cellophane (trademark) peels off. (Guideline: 50-100%)

(7) Method for Measuring Content of (Poly) alkylene Glycol Component A radiation curable resin was divided into each component by preparative GPC, and a structure constituted by performing pyrolysis GC-MS for each component was identified. Thereafter, each component was quantified from the peak integrated value of ¹ H-NMR, and the content of the (poly) alkylene glycol component was identified.
[Preparation GPC conditions]
Column: JAIGEL-2H x 2 600 x 22 mmI. D. (Nippon Analytical Industry)
Mobile phase solvent: chloroform 3.5 ml / min
[Pyrolysis GC-MS conditions]
Pyrolysis temperature: 600 ° C simple pyrolysis and on-line methylation Pyrolysis methylating agent: tetramethylammonium hydroxide (TMAH)
Column: ZB-1, length 30 m × inner diameter 0.32 mm, film thickness 0.5 μm
GC temperature: 40 ° C. (0 min), 15 ° C./min, 322 ° C. (10 min)
[Quantification by ¹ H-NMR]
Calculation formula: Content = molecular weight × (integral ratio / ¹ H number), normalized so that the sum is 100.
As for pentaerythritol triacrylate and dipentaerythritol pentaacrylate, it was assumed that the area ratio of GPC coincided with the weight ratio, and the integral value (1000) of acrylic groups in ¹ H-NMR was assigned to the ratio.

(8) Fingerprint resistance evaluation (8-1) How to view fingerprints Place the hard coat film on a glass plate with the back side painted black, and press the finger against the end face of the hard coat film, so that half of the fingerprint is on the film. Half was attached to the glass simultaneously. The appearance from the front of the fingerprint was judged based on the following criteria: ○: The fingerprint on the hard coat is hardly visible △: The fingerprint on the hard coat and the fingerprint on the glass stand out to the same extent ×: On the hard coat (8-2) Fingerprint wiping property Fingers were pressed against the hard coat film surface to attach the fingerprints, and then wiped back and forth five times using tissue paper. The following criteria were used to determine how the fingerprints looked after: ○: The fingerprints were not visible after wiping. △: The fingerprints remained after being wiped.

(9) Glass transition temperature (Tg)
About 10 mg for resin samples and about 20 mg for film samples (base film) are sealed in an aluminum pan for measurement and attached to a differential scanning calorimeter (DSC) (DuPont Instrument 910 DSC). The temperature was raised to 290 ° C. at a rate of 20 ° C./min, held at 290 ° C. for 3 minutes, then taken out, immediately transferred onto ice and rapidly cooled. The pan was mounted on the DSC again, and the temperature was raised from 25 ° C. at a rate of 20 ° C./min, and the glass transition temperature Tg (unit: ° C.) was measured.

[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 The following HC agent was applied to one side (polyester film having an easy-adhesion layer having a thickness of 75 nm on both sides) (this side is the front side).
HC agent: as radiation curable resin A, beam set 1460 (trade name, manufactured by Arakawa Chemical Industries, Ltd., acrylic polymer mainly composed of pentaerythritol triacrylate and dipentaerythritol pentaacrylate (mass ratio: 83/17), As a (poly) alkylene glycol component, a resin in which 2.9% by mass of repeating ethylene glycol units (polyethylene glycol having a molecular weight of 2,000 to 6,000) is copolymerized with respect to the mass of the acrylic polymer, and photopolymerization is started. Methyl ethyl ketone (MEK) / xylene = 9/1 (mass ratio) mixed solution, solid content concentration 80% by mass.) 100 parts by mass with t-butanol 135 parts by mass A coating solution having a concentration of 34% by mass was obtained. The (poly) alkylene glycol component was confirmed to be copolymerized by analysis such as ¹ H-NMR, IR, and GC-MS.
The coating was performed by a reverse gravure coating method so that the coating thickness after drying was 6 μm, and was dried under conditions of 70 ° 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 of the base film opposite to the surface on which the hard coat layer A is formed, a hard coat paint manufactured by Arakawa Chemical Industries, Ltd. 1460), silica particles having an average particle diameter of 100 nm (trade name MEK-ST-ZL) added thereto so as to be 2% by mass with respect to the mass of the hard coat layer B, reverse gravure coating In this method, coating was performed such that the coating thickness after drying was 2.0 μm, and drying was performed at 70 ° C. for 2 minutes. Subsequently, the hard coat layer B was formed by irradiating with 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). The obtained hard coat film was excellent in winding property, and could be wound up without attaching a protective film. The properties of the obtained hard coat film are shown in Table 1.

[Example 2]
As an HC agent for forming the hard coat layer A, Forse Seed No. manufactured by China Paint Co., Ltd. A hard coat film was obtained in the same manner as in Example 1 except that 423C (solid content 50%) was used as it was. The obtained hard coat film was excellent in winding property, and could be wound up without attaching a protective film. The properties of the obtained hard coat film are shown in Table 1.

[Example 3]
In the formation of the hard coat layer B, a hard coat film was formed in the same manner as in Example 1 except that ultraviolet irradiation was performed in a nitrogen purge atmosphere with an oxygen concentration of 1000 ppm or less and the thickness of the hard coat layer B after drying was 1.0 μm. Got. The obtained hard coat film was excellent in winding property, and could be wound up without attaching a protective film. The properties of the obtained hard coat film are shown in Table 1.

[Example 4]
In the hard coat layer B, a hard coat film was obtained in the same manner as in Example 1 except that no silica particles were added. The obtained hard coat film had a low winding property, and it was necessary to wind up after a protective film (manufactured by SANA Chemical Co., Ltd., PAC-3-60) was bonded with a nip roll before winding. The properties of the obtained hard coat film are shown in Table 1.

[Example 5]
In the HC agent for forming the hard coat layer B, Aika Itron Z-770UH manufactured by Aika Industry Co., Ltd. is used as the radiation curable resin B, and the amount of the diluent solvent is adjusted so that the solid content concentration of the HC agent is the same. A hard coat film was obtained in the same manner as in Example 4 except for the adjustment. The obtained hard coat film had a low winding property, and it was necessary to wind up after a protective film (manufactured by SANA Chemical Co., Ltd., PAC-3-60) was bonded with a nip roll before winding. The properties of the obtained hard coat film are shown in Table 1.

[Example 6]
A hard coat film was formed in the same manner as in Example 5 except that in the formation of the hard coat layer B, ultraviolet irradiation was performed in a nitrogen purge atmosphere having an oxygen concentration of 1000 ppm or less, and the thickness of the hard coat layer B after drying was changed to 0.5 μm. Got. The obtained hard coat film had a low winding property, and it was necessary to wind up after a protective film (manufactured by SANA Chemical Co., Ltd., PAC-3-60) was bonded with a nip roll before winding. The properties of the obtained hard coat film are shown in Table 1.

[Example 7]
In the preparation of the coating liquid for forming the hard coat layer A of Example 1, as the radiation curable resin, the copolymerization ratio of ethylene glycol units was 2.2% by mass with respect to the mass of the acrylic polymer. A hard coat film was obtained in the same manner as in Example 1 except that was used. The obtained hard coat film was excellent in winding property, and could be wound up without attaching a protective film. The properties of the obtained hard coat film are shown in Table 1.

[Example 8]
In the preparation of the coating liquid for forming the hard coat layer A of Example 1, as a radiation curable resin, the copolymerization ratio of ethylene glycol units repeatedly was 3.8% by mass with respect to the mass of the acrylic polymer. A hard coat film was obtained in the same manner as in Example 1 except that was used. The obtained hard coat film was excellent in winding property, and could be wound up without attaching a protective film. The properties of the obtained hard coat film are shown in Table 1.

[Examples 9 to 12]
A hard coat film was obtained in the same manner as in Example 1 except that the thickness of the hard coat layers A and B after drying was as shown in Table 1. When the thickness was 1 μm or less, ultraviolet irradiation was performed in a nitrogen purge atmosphere with an oxygen concentration of 1000 ppm or less. Each of the obtained hard coat films was excellent in winding property and could be wound up without attaching a protective film. The properties of the obtained hard coat film are shown in Table 1.

[Example 13]
A hard coat film was obtained in the same manner as in Example 1 except that the hard coat paint (Z-7812-13) manufactured by Aika Kogyo Co., Ltd. was used as the HC agent for forming the hard coat layer B. The obtained hard coat film was excellent in winding property, and could be wound up without attaching a protective film. The properties of the obtained hard coat film are shown in Table 1.

[Comparative 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 A hard coat paint (Desolite Z7501) manufactured by JSR Co., Ltd. as a HC agent is applied to one side of the polyester film having a 75 nm thick easy-adhesion layer on both sides (this side is the front side). The coating method was applied so that the coating thickness after drying was 6 μm, and dried under the conditions of 70 ° C. × 2 minutes, and then an ultraviolet irradiation device (FusionUV Systems Japan Co., Ltd .: trade name Fusion H bulb) Was used to form a hard coat layer A by irradiating ultraviolet rays under the condition of a light amount of 200 mJ / cm ² .
Next, on the surface opposite to the surface on which the hard coat layer A is formed in the base film, the same HC agent as the front surface is applied by a reverse gravure coating method so that the coating thickness after drying becomes 2.0 μm. It was coated and dried under 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 obtained hard coat film had a low winding property, and it was necessary to wind up after a protective film (manufactured by SANA Chemical Co., Ltd., PAC-3-60) was bonded with a nip roll before winding. The properties of the obtained hard coat film are shown in Table 1.

[Comparative Examples 2 to 7]
A hard coat film was obtained in the same manner as in Example 1 except that the thickness of the hard coat layers A and B after drying was as shown in Table 1. Each of the obtained hard coat films was excellent in winding property and could be wound up without attaching a protective film. The properties of the obtained hard coat film are shown in Table 1.

  Since the hard coat film of the present invention is excellent in punching processability and at the same time excellent in fingerprint resistance, it is suitably used for applications in which punching process is performed. In particular, it can be suitably used for an icon sheet.

Claims (4)

  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, the thickness of the hard coat layer A is 0.5 μm or more thicker than the thickness of the hard coat layer B, and the contact angle of water on the surface of the hard coat layer A is 78 ° or more and 90 °. A hard coat film having a contact angle of n-dodecane of 20 degrees or less.   The hard coat film of Claim 1 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.   The hard coat film according to claim 1 or 2, wherein the hard coat layer B contains 2 to 10% by mass of inert particles having an average particle size of 50 to 500 nm based on the mass of the hard coat layer B.   The hard coat film according to any one of claims 1 to 3, wherein the contact angle of water on the surface of the hard coat layer B is 88 degrees or less and the contact angle of n-dodecane is 20 degrees or less.