JP5909925B2 - Hard coat film - Google Patents

Description

  The present invention relates to a hard coat film that is excellent in the ability to prevent the back side of an adhesive liquid from flowing around.

  In recent years, various display devices such as a liquid crystal television, a plasma display (PDP), and an organic EL display have been developed in addition to a CRT, and their screen sizes are increasing. Along with the increase in screen size and image quality, a hard coat film on which an antireflection layer or the like is formed is attached to the front surface of a display device in order to improve visibility. Moreover, in such a display apparatus, a hand may touch directly or an object may contact, and it is easy to get a damage | wound. Accordingly, a hard coat film with a hard coat layer in which a hard coat layer is formed on a transparent film substrate for preventing scratches and an antireflection layer or the like further formed thereon has been used.

  As such a hard coat film for a display device, a wide film having a size of 1000 mm or more and further 2000 mm or more has recently been required due to the enlargement of the screen. In addition, a thin transparent film substrate having a thickness of about 40 μm has been used for mobile phones and notebook computers. Therefore, a resin film such as cellulose ester is used for the transparent film substrate, and a hard coat layer, an antireflection layer, an antifouling layer or an antiglare layer is formed thereon as an optical functional layer. .

  When the transparent film substrate becomes wider as described above, color unevenness and periodic unevenness occur in reflection performance, coloring degree, phase difference performance, visual field expansion performance, and the like.

  For such a problem, for example, Patent Document 1 discloses a hard coat film in which a knurling portion is further laminated on a coated hard coat layer or a functional layer on a transparent film substrate that has already been knurled. The manufacturing method of this is proposed.

  On the other hand, a wide transparent film base material tends to generate a non-uniform portion of the roll tightening at the stage of winding the hard coat film after forming the optical functional layer or the like. This non-uniform winding of the roll also facilitates adhesion between the film surfaces (hereinafter referred to as blocking). A film fed out from a roll in which blocking occurs causes wrinkles, scratches, etc., and cannot be applied to a display device, resulting in a decrease in yield.

  For such a problem, Patent Document 2 proposes a hard coat film provided with a knurling portion that is 2 μm or more higher than the thickness of the functional layer.

  However, the hard coat films disclosed in Patent Documents 1 and 2 described above are such that the adhesive liquid applied to adhere the hard coat film to a display screen such as a display is hard coated from both ends of the transparent film substrate. There was a problem around the so-called liquid back, which reached the layer side.

Patent No. 4479260 JP-A-2005-77795

  The present invention has been made in view of such circumstances, and its purpose extends to the hard coat layer side where the adhesive liquid is not applied when the adhesive liquid is applied to the transparent film substrate side of the optical film. An object of the present invention is to provide a hard coat film that suppresses the so-called back of the adhesive liquid.

  As a result of intensive studies by the inventors of the present invention to achieve the above object, a specific number of embosses are processed at both ends of a hard coat film in which a hard coat layer having high hardness is formed on a transparent film substrate, and transparent A convex knurling portion was also provided on the surface of the film base opposite to the side on which the hard coat layer was formed. As a result, the adhesive liquid applied to the transparent film substrate in order to attach the hard coat film to the display is blocked by the knurling part of the convex part, so that the back of the adhesive liquid can be suppressed. The inventors have found that a coated film can be obtained, and have completed the present invention.

That is, the hard coat film according to the present invention is a hard coat film in which a hard coat layer having an elastic modulus of 5.0 GPa or more is formed on one surface of a transparent film substrate, and both ends of the hard coat film. The surface of the hard coat layer is provided with 10 to 140 knurling irregularities per 1 cm ² , and the hard coat layer of the transparent film base is formed so as to correspond to the recesses applied to the hard coat layer. The convex part of the said knurling part is given to the surface on the opposite side to the made side.

Moreover, it is suitable to have an adhesive liquid layer on the surface opposite to the side on which the hard coat layer is provided.

  The pressure-sensitive adhesive layer preferably contains at least one selected from an acrylic pressure-sensitive adhesive, a silicone-based pressure-sensitive adhesive, a urethane-based pressure-sensitive adhesive, and a rubber-based pressure-sensitive adhesive.

  The hard coat layer preferably contains at least one polyfunctional acrylate.

The polyfunctional (meth) acrylate is preferably isocyanuric acid-modified acrylate.

  The elastic modulus of the transparent film substrate is preferably 3.0 to 4.5 GPa.

Further, the transparent film substrate is suitably a polyester film with Ekise' adhesive layer.

  According to this invention, the hard coat film which can suppress the back circumference of an adhesive liquid can be provided.

It is a top view of the hard coat film concerning the present invention, and a sectional view of a knurling part.

  Hereinafter, embodiments according to the present invention will be described, but the present invention is not limited thereto.

The hard coat film according to the present invention is a hard coat film in which a hard coat layer having an elastic modulus of 5.0 GPa or more is formed on one surface of a transparent film substrate, and at both ends of the hard coat film, The surface of the hard coat layer is provided with 10 to 140 knurling irregularities per 1 cm ² , and the hard coat layer of the transparent film substrate is formed so as to correspond to the concave portions provided on the hard coat layer. A convex portion of the knurling portion is provided on a surface opposite to the side.

[Knurling part]
First, the knurling part according to the present invention will be described.

  The knurling part in the hard coat film of the present invention is one obtained by embossing an uneven band at both ends with respect to the winding direction of the hard coat film.

  In the conventional hard coat film, a knurling part is provided only on the side surface of the base film on which the hard coat layer is provided in order to prevent blocking that occurs when the roll-shaped film is wound. Most of them were. On the other hand, in the hard coat film of the present invention, the hard coat of the transparent film substrate was formed by further embossing the entire hard coat film having the hard coat layer formed on one side of the transparent film substrate. The convex part of the knurling part is also given to the surface opposite to the side.

  The hard coat film of the present invention is affixed to a display device such as a display for reasons of improved visibility and prevention of damage. When pasting on this display device, the adhesive liquid is applied to the transparent film substrate surface on which the hard coat film is not formed.

  In the conventional hard coat film, since convex knurling is not applied to the transparent film substrate as in the present invention, the excess adhesive solution applied to the transparent film substrate is applied with the adhesive solution. There was a so-called back of the liquid that would flow to the hard coat layer side.

  However, in the present invention, the convex knurling portion of the transparent film base as described above plays a role of blocking the adhesive liquid applied to the transparent film base, and therefore suppresses the back of the adhesive liquid. be able to.

  The shape of the unevenness of the knurling portion is not particularly limited, and the arrangement may be random or linear, and various patterns can be used. Moreover, when the said linear knurling part is given, it is preferable that it is a linear form of multiple rows rather than a linear form of one row. This is because if there are a plurality of knurling portions in the width direction, the flow of the adhesive liquid can be suppressed in stages.

The number of these knurling parts is 10-140 per cm < ² >, Preferably it is 30-120. When the number is less than 10, the knurling of the winding core portion is crushed during long winding, and blocking occurs. When the number is more than 140, the pushing force is insufficient and a sufficient height cannot be obtained during the knurling process. Further, the ratio of the area of the portion observed as the embossing protrusion to the entire embossed portion is preferably about 15 to 50%.

  As a method of providing unevenness as a knurling portion, it can be formed by pressing a heated embossing roll on the film. The knurling portion can be applied at room temperature, but it is preferable to process the film at a glass transition temperature (Tg) + 20 ° C. or higher and a melting point (Tm) + 30 ° C. or lower.

  Fine embossing is formed on the embossing roll. By pressing this embossing roll, unevenness can be formed on the film and the end can be made bulky. The embossed height according to the present invention refers to a thickness obtained by subtracting the thickness of the base material before the knurling portion is formed from the total thickness of the convex portions of the embossed portion. Moreover, when a hard coat film is formed, it means the thickness obtained by subtracting the thickness of the base material and the hard coat layer before forming the knurling portion from the total thickness of the convex portions of the embossed portion. This is achieved by using an embossing roll that has been engraved into irregularities so that the height of the convex portions becomes a desired height at the stage of processing the embossing rolls.

  The width of the knurling part is not particularly limited, but is 0.5 cm to 3 cm, preferably 1 to 2.5 cm, particularly preferably 1.5 to 2 cm. Although the position of a knurling part is not specifically limited, It is preferable that the embossing is given to the part of 0-50 mm from the film edge part.

  FIG. 1 is a schematic view of a knurling portion according to the present invention. However, the figure is an example, and the present invention is not limited to this. Fig.1 (a) is a top view of the hard coat film of this invention, FIG.1 (b) is sectional drawing shown by IB-IB of Fig.1 (a).

  The hard coat film of this invention is manufactured as follows, for example.

  First, the knurling part is provided in advance by pressing the embossing rolls against both ends of the transparent base film 3 during manufacture. The knurling part provided for this transparent substrate film may or may not be provided. Next, after the hard coat layer 2 is formed on the transparent film substrate 3, a convex knurling portion 5 and a concave knurling portion 4 'are applied to the hard coat layer 2 side, and at the same time a transparent film base A convex knurling portion 4 is provided on the material 2 side. These knurling portions may be provided by using an embossing roll heated after winding the hard coat layer 3 on the transparent film substrate 2.

  And the effect of this invention will be acquired if the convex knurling part 4 is provided in the surface on the opposite side to the side in which the hard-coat layer 2 of the transparent film base material 3 was formed. That is, when the hard coat film 1 of the present invention is affixed to the display device or the like, the adhesive liquid layer 6 is applied to the film 1, and this adhesive liquid is wrapped around the back of the adhesive liquid by the knurling part 4. Suppressed.

  When the number of knurling portions 5 on the transparent film base hard coat layer is small or absent, wrinkles or scratches are generated on the hard coat film when the hard coat film is wound as a roll film.

  In the present invention, the convex knurling portion 5 and the concave knurling portion 4 ′ on the hard coat layer side are preferably provided at different positions. By providing these knurling portions at different positions, the liquid back periphery deterring effect is effectively achieved, and the blocking preventing effect is also synergistically achieved.

  Further, the transparent film substrate 2 may be a substrate film with an easy adhesion layer. If it is a base film with an easy-adhesion layer, the hard coat layer 3 can be easily formed on the transparent film base 2 simply by thermocompression bonding of the hard coat layer.

  The elastic modulus of the hard coat layer is 5.0 GPa or more. When the elastic modulus of the hard coat layer is smaller than 5.0 GPa, when the hard coat film is wound as a roll film, the knurling part 4 is crushed due to the embossing being pressed by the winding pressure, and as a result, the adhesion It becomes impossible to maintain an embossed height that can prevent the liquid back circumference.

  The thickness of the knurling part 4 is preferably 1 to 20 μm, and more preferably 3 to 10 μm. If the thickness of the knurling part 4 is smaller than 1 μm, a minute unevenness of the film surface called “Yuzu skin” is likely to occur, and the periphery of the liquid back cannot be suppressed. On the other hand, when the thickness is larger than 20 μm, the thickness of the winding end portion is increased (ear-out failure), and the film is deformed to deteriorate the winding shape.

  The width of the hard coat film in which the hard coat layer and the transparent film substrate are laminated is 1 m or more, so that the production efficiency and the utilization efficiency when the antireflection film is applied to a display device are high, preferably 1.3. ~ 4m. When such a wide hard coat film is used, it is preferable that the knurling portions 4, 4 ′ and the knurling portion 5 are provided not only at the end of the transparent film substrate but also inside thereof. That is, it is preferable to provide a plurality of rows of knurling portions. For example, if a knurling part is provided at the center of the hard coat film, blocking that may occur at the center of the wide transparent film substrate can be effectively prevented.

  In the present invention, in order to increase the uniformity of the winding core side to the winding center portion to the winding outside when the hard coat film is wound into a roll, the thickness of the winding core side knurling portion is more than the winding outside knurling portion thickness. The thickness difference is preferably in the range of 1 to 10 μm, and more preferably in the range of 3 to 8 μm. For example, by changing the embossing roll so that the core side emboss thickness (15 μm) / winding center part emboss thickness (10 μm) / winding side emboss thickness (5 μm) are combined, the core side direction Even if the embossing is pressed by the winding pressure, a desired embossing thickness can be ensured.

(Heat treatment)
When the hard coat film having these knurling portions is wound up in a roll shape and wound in a roll shape, when the heat treatment is performed at 42 ° C. or more for 3 days or more, 10 ° C. to 30 ° C. / It is preferable to heat at a daily temperature increase rate. The treatment temperature is preferably in the range of 50 ° C to 120 ° C, and the period is preferably 3 days to 30 days.

  If the rate of temperature increase during the heat treatment exceeds 30 ° C./day, the hard coat film will rapidly expand, and wrinkles are likely to occur near the core, which is not preferable. Further, if it is less than 10 ° C./day, productivity is remarkably inferior, which is not realistic.

  There is no particular limitation on the temperature rising pattern, and a linear, curvilinear or stepwise pattern may be taken for optimization. Further, there may be a temporary temperature drop during the temperature rising period.

  Although there is no restriction | limiting in particular in the temperature fall after heat processing, In order to make the shrinkage | contraction of a hard coat film uniform, it is preferable to reduce temperature by the 10-30 degreeC / day temperature fall pattern similarly to temperature rising.

  In order to stably perform the heat treatment, it is preferably performed in a place where the temperature and humidity can be adjusted, and particularly preferably performed in a heat treatment chamber such as a clean room without dust.

  Any material can be used as a wound core when winding a hard coat film having a knurling portion or a hard coat film coated with a hard coat layer and a functional layer into a roll shape. However, it is preferably a hollow plastic core, and the plastic material may be any heat-resistant plastic that can withstand the heat treatment temperature. For example, phenol resin, xylene resin, melamine Resins, polyester resins, epoxy resins and the like can be mentioned. A thermosetting resin reinforced with a filler such as glass fiber is preferable.

  The number of windings to these winding cores is preferably 100 windings or more, more preferably 500 windings or more, the winding thickness is preferably 5 cm or more, and the width of the film substrate is 80 cm or more. It is preferably 1 m or more.

  When the heat treatment is performed in a state where the roll wound around the plastic core is coated with the hard coat layer or the hard coat layer and the functional layer on the long transparent plastic film substrate in this way. The roll is preferably rotated, and the rotation is preferably performed at a speed of 1 rotation or less per minute, and may be continuous or intermittent. Moreover, it is preferable to perform rewinding of the roll once or more during the heating period.

[Hard coat layer]
The hard coat layer according to the present invention will be described.

  The hard coat layer according to the present invention is provided on one surface of the transparent film substrate.

  In addition, the hard coat film in this invention means the film whose pencil hardness is H-8H. Most preferably, it is 2H-6H. The pencil hardness is evaluated by pencil hardness evaluation specified by JIS K 5400 using a test pencil specified by JIS S 6006 after the prepared hard coat film is conditioned at a temperature of 25 ° C. and a relative humidity of 60% for 2 hours. It is the value measured according to the method.

(Polyfunctional acrylate)
As the composition contained in the hard coat layer, an actinic ray curable resin such as ultraviolet ray is generally used. In the present invention, it is preferable to contain a polyfunctional acrylate as such an actinic ray curable resin. The polyfunctional acrylate is preferably selected from the group consisting of pentaerythritol polyfunctional acrylate, dipentaerythritol polyfunctional acrylate, pentaerythritol polyfunctional methacrylate, and dipentaerythritol polyfunctional methacrylate. Here, the polyfunctional acrylate is a compound having two or more acryloyloxy groups and / or methacryloyloxy groups in the molecule.

  Examples of the polyfunctional acrylate monomer include ethylene glycol diacrylate, diethylene glycol diacrylate, 1,6-hexanediol diacrylate, neopentyl glycol diacrylate, trimethylolpropane triacrylate, trimethylolethane triacrylate, and tetramethylolmethane triacrylate. , Tetramethylolmethane tetraacrylate, pentaglycerol triacrylate, pentaerythritol diacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, glycerin triacrylate, dipentaerythritol triacrylate, dipentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, dipentaerythritol Lithol hexaacrylate, tris (acryloyloxyethyl) isocyanurate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, 1,6-hexanediol dimethacrylate, neopentyl glycol dimethacrylate, trimethylolpropane trimethacrylate, trimethylolethane trimethacrylate, Tetramethylol methane trimethacrylate, tetramethylol methane tetramethacrylate, pentaglycerol trimethacrylate, pentaerythritol dimethacrylate, pentaerythritol trimethacrylate, pentaerythritol tetramethacrylate, glycerol trimethacrylate, dipentaerythritol trimethacrylate, dipentaerythritol tetramethacrylate Acrylate, dipentaerythritol penta methacrylate, dipentaerythritol hexa methacrylate, isobornyl acrylate and the like preferably. These compounds are used alone or in admixture of two or more. Moreover, oligomers, such as a dimer and a trimer of the said monomer, may be sufficient.

  Moreover, it is preferable to contain isocyanuric acid modified acrylate in addition to the above (meth) acrylate. For example, it is selected from modified isocyanuric acid EO-modified diacrylate, modified isocyanuric acid EO-modified triacrylate, and the like.

  The addition amount of the actinic ray curable resin is preferably 15% by mass or more and less than 70% by mass in the solid content in the hard coat layer composition.

  In order to accelerate the curing of the actinic ray curable resin, a photopolymerization initiator and an acrylic compound having at least two polymerizable unsaturated bonds in the molecule are contained in a mass ratio of 20: 100 to 0.01: 100. It is preferable.

  Specific examples of the photopolymerization initiator include acetophenone, benzophenone, hydroxybenzophenone, Michler's ketone, α-amyloxime ester, thioxanthone, and derivatives thereof, but are not particularly limited thereto.

In the hard coat layer according to the present invention, a binder such as a known thermoplastic resin, thermosetting resin or hydrophilic resin such as gelatin can be mixed with the actinic ray curable resin. These resins preferably have a polar group in the molecule. Examples of the polar _{group, -COOM, -OH, -NR 2,} -NR 3 X, -SO 3 M, -OSO 3 M, -PO 3 M 2, -OPO 3 M ( wherein, M represents a hydrogen atom, an alkali A metal or an ammonium group, X represents an acid forming an amine salt, R represents a hydrogen atom or an alkyl group).

  Examples of commercially available actinic radiation curable resins that can be used in the present invention include ADEKA OPTMER KR / BY series: KR-400, KR-410, KR-550, KR-566, KR-567, BY-320B (Asahi) Manufactured by Denka Co., Ltd.); Koei Hard A-101-KK, A-101-WS, C-302, C-401-N, C-501, M-101, M-102, T-102, D-102 NS-101, FT-102Q8, MAG-1-P20, AG-106, M-101-C (manufactured by Guangei Chemical Co., Ltd.); Seika Beam PHC2210 (S), PHC X-9 (K-3), PHC2213 , DP-10, DP-20, DP-30, P1000, P1100, P1200, P1300, P1400, P1500, P1600, SCR900 (Daiichi Seikagaku Corporation )); KRM7033, KRM7039, KRM7130, KRM7131, UVECRYL29201, UVECRYL29202 (manufactured by Daicel UC Corporation); RC-5015, RC-5016, RC-5020, RC-5031, RC-5100, RC-5102, RC-5120, RC-5122, RC-5152, RC-5171, RC-5180, RC-5181 (Dainippon Ink Chemical Co., Ltd.); 340 clear (manufactured by China Paint Co., Ltd.); Sunrad H-601, RC-750, RC-700, RC-600, RC-500, RC-611, RC-612 (manufactured by Sanyo Chemical Industries); SP -1509, SP-1507 (manufactured by Showa Polymer Co., Ltd.); RCC-15C (manufactured by Grace Japan Co., Ltd.), Aronix M-6100, M-8030, M-8060 (manufactured by Toagosei Co., Ltd.); B420 (manufactured by Shin-Nakamura Chemical Co., Ltd.) or the like can be appropriately selected and used.

  Further, the hard coat layer may contain fine particles of an inorganic compound or an organic compound in order to adjust the scratch resistance, slipperiness and refractive index.

  Examples of inorganic fine particles used in the hard coat layer include silicon oxide, titanium oxide, aluminum oxide, tin oxide, indium oxide, ITO, zinc oxide, zirconium oxide, magnesium oxide, calcium carbonate, calcium carbonate, talc, clay, and calcined kaolin. And calcined calcium silicate, hydrated calcium silicate, aluminum silicate, magnesium silicate and calcium phosphate. In particular, silicon oxide, titanium oxide, aluminum oxide, zirconium oxide, magnesium oxide and the like are preferably used.

  Organic particles include polymethacrylic acid methyl acrylate resin powder, acrylic styrene resin powder, polymethyl methacrylate resin powder, silicon resin powder, polystyrene resin powder, polycarbonate resin powder, benzoguanamine resin powder, melamine resin powder. An ultraviolet curable resin composition such as polyolefin resin powder, polyester resin powder, polyamide resin powder, polyimide resin powder, or polyfluoroethylene resin powder can be added. Particularly preferred are cross-linked polystyrene particles (for example, SX-130H, SX-200H, SX-350H manufactured by Soken Chemical), polymethyl methacrylate particles (for example, MX150, MX300 manufactured by Soken Chemical), and fluorine-containing acrylic resin fine particles. The Examples of the fluorine-containing acrylic resin fine particles include commercial products such as FS-701 manufactured by Nippon Paint. Examples of the acrylic particles include Nippon Paint: S-4000, and examples of the acrylic-styrene particles include Nippon Paint: S-1200, MG-251.

  The average particle diameter of these fine particle powders is preferably 0.01 to 5 μm, more preferably 0.1 to 5.0 μm, and particularly preferably 0.1 to 4.0 μm. Further, it is preferable to contain two or more kinds of fine particles having different particle diameters. The proportion of the ultraviolet curable resin composition and the fine particles is desirably blended so as to be 0.1 to 30 parts by mass with respect to 100 parts by mass of the resin composition. In order to increase the heat resistance of the hard coat layer, an antioxidant that does not inhibit the photocuring reaction can be selected and used. Examples include hindered phenol derivatives, thiopropionic acid derivatives, phosphite derivatives, and the like. Specifically, for example, 4,4′-thiobis (6-tert-3-methylphenol), 4,4′-butylidenebis (6-tert-butyl-3-methylphenol), 1,3,5-tris (3,5-di-tert-butyl-4-hydroxybenzyl) isocyanurate, 2,4,6-tris (3,5-di-tert-butyl-4-hydroxybenzyl) mesitylene, di-octadecyl-4- Examples thereof include hydroxy-3,5-di-tert-butylbenzyl phosphate. These hard coat layers can be coated by a known method such as a gravure coater, a dip coater, a reverse coater, a wire bar coater, a die coater, or an ink jet method. After application, it is heat-dried and UV-cured.

  The hard coat layer coating solution may contain a solvent, or may be appropriately contained and diluted as necessary. Examples of the organic solvent contained in the coating solution include hydrocarbons (toluene, xylene), alcohols (methanol, ethanol, isopropanol, butanol, cyclohexanol), ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone), It can be appropriately selected from esters (methyl acetate, ethyl acetate, methyl lactate), glycol ethers, and other organic solvents, or a mixture thereof can be used. Propylene glycol monoalkyl ether (1 to 4 carbon atoms of the alkyl group) or propylene glycol monoalkyl ether acetate ester (1 to 4 carbon atoms of the alkyl group) is 5% by mass or more, more preferably 5 to 80%. It is preferable to use the organic solvent containing at least mass%.

  The hard coat layer has a center line average roughness (Ra) defined by JIS B 0601 of 0.001 to 0.1 μm, or a fine hard coat layer and Ra is adjusted to 0.1 to 1 μm. An antiglare hard coat layer may also be used. The center line average roughness (Ra) is preferably measured by an optical interference type surface roughness measuring instrument, and can be measured, for example, using a non-contact surface fine shape measuring device WYKO NT-2000 manufactured by WYKO.

  Further, the hard coat layer preferably contains a silicone surfactant or a polyoxyether compound. As the silicone surfactant, polyether-modified silicone is preferable, and specifically, BYK-UV3500, BYK-UV3510, BYK-333, BYK-331, BYK-337 (manufactured by BYK-Chemical Japan), TSF4440, TSF4445, TSF4446, TSF4452, TSF4460 (GE Toshiba Silicone), KF-351, KF-351A, KF-352, KF-353, KF-354, KF-355, KF-615, KF-618, KF-945, KF- 6004 (polyether-modified silicone oil; manufactured by Shin-Etsu Chemical Co., Ltd.), and the like, but are not limited thereto.

  Of the polyoxyether compounds, the polyoxyethylene oleyl ether compound is preferable, and is generally a compound represented by the general formula (α).

Formula _{(α): C 18 H 35} -O (C 2 H 4 O) nH ( wherein, n represents 2-40.)

  The average addition number (n) of ethylene oxide with respect to the oleyl part is 2 to 40, preferably 2 to 10, more preferably 2 to 9, and further preferably 2 to 8. The compound of the general formula (α) can be obtained by reacting ethylene oxide with oleyl alcohol.

  Specific products include Emulgen 404 (polyoxyethylene (4) oleyl ether), Emulgen 408 (polyoxyethylene (8) oleyl ether), Emulgen 409P (polyoxyethylene (9) oleyl ether), Emulgen 420 (polyoxy) Ethylene (13) oleyl ether), Emulgen 430 (polyoxyethylene (30) oleyl ether) or more, Kao Corporation, NOFBLEEAO-9905 (polyoxyethylene (5) oleyl ether) manufactured by NOF Corporation.

  In addition, () represents the number of n. Nonionic polyoxyether compounds may be used alone or in combination of two or more.

  These components are preferably added in the range of 0.01 to 3% by mass with respect to the solid component in the coating solution in order to improve the coating property.

  Further, the hard coat layer may contain a fluorine-siloxane graft polymer.

  The fluorine-siloxane graft polymer refers to a copolymer polymer obtained by grafting polysiloxane containing siloxane and / or organosiloxane alone and / or organopolysiloxane to at least a fluorine-based resin. Examples of commercially available products include ZX-022H, ZX-007C, ZX-049, and ZX-047-D manufactured by Fuji Kasei Kogyo Co., Ltd. These compounds may be used as a mixture. Fluorine-siloxane graft polymer should be used in a coating solution that has a mass ratio of actinic ray curable resin to fluorine-siloxane graft polymer: energy-active radiation curable resin = 0.05: 100 to 5.00: 100. To preferred.

  The hard coat layer may have a multilayer structure of two or more layers. One of the layers may be a so-called conductive layer containing, for example, conductive fine particles, a π-conjugated conductive polymer, or an ionic polymer. Examples of the π-conjugated conductive polymer include polythiophene, poly (3-methylthiophene), poly (3-ethylthiophene), poly (3-propylthiophene), poly (3-butylthiophene), and poly (3-hexylthiophene). , Poly (3-octylthiophene), poly (3-decylthiophene), poly (3-dodecylthiophene), poly (3-bromothiophene), poly (3-chlorothiophene), poly (3-cyanothiophene), poly (3-phenylthiophene), poly (3,4-dimethylthiophene), poly (3,4-dibutylthiophene), poly (3-hydroxythiophene), poly (3-methoxythiophene), poly (3-ethoxythiophene) , Poly (3-butoxythiophene), poly (3-hexyloxythiophene), poly (3 Octyloxythiophene), poly (3-decyloxythiophene), poly (3-dodecyloxythiophene), poly (3,4-dihydroxythiophene), poly (3,4-dimethoxythiophene), poly (3,4-di Ethoxythiophene), poly (3,4-dipropoxythiophene), poly (3,4-dibutoxythiophene), poly (3,4-dihexyloxythiophene), poly (3,4-dioctyloxythiophene), poly ( 3,4-didecyloxythiophene), poly (3,4-didodecyloxythiophene), poly (3,4-ethylenedioxythiophene), poly (3,4-propylenedioxythiophene), poly (3,4 4-butenedioxythiophene), poly (3-methyl-4-methoxythiophene), poly (3-methyl-4 -Ethoxythiophene), poly (3-carboxythiophene), poly (3-methyl-4-carboxythiophene), poly (3-methyl-4-carboxyethylthiophene), poly (3-methyl-4-carboxybutylthiophene) , Polypyrrole, poly (N-methylpyrrole), poly (3-methylpyrrole), poly (3-ethylpyrrole), poly (3-N-propylpyrrole), poly (3-butylpyrrole), poly (3-octyl) Pyrrole), poly (3-decylpyrrole), poly (3-dodecylpyrrole), poly (3,4-dimethylpyrrole), poly (3,4-dibutylpyrrole), poly (3-carboxypyrrole), poly (3 -Methyl-4-carboxypyrrole), poly (3-methyl-4-carboxyethylpyrrole), poly (3-methyl 4-carboxybutylpyrrole), poly (3-hydroxypyrrole), poly (3-methoxypyrrole), poly (3-ethoxypyrrole), poly (3-butoxypyrrole), poly (3-hexyloxypyrrole), poly ( 3-methyl-4-hexyloxypyrrole), polyaniline, poly (2-methylaniline), poly (3-isobutylaniline), poly (2-anilinesulfonic acid), poly (3-anilinesulfonic acid) and the like. . Each of these may be used alone or two types of copolymers can be suitably used.

  Further, the ionic polymer may contain a color tone adjusting agent (dye or pigment) having a color tone adjusting function as a color correction filter for various display elements, or may contain an electromagnetic wave blocking agent or an infrared absorber. It is preferable to have each function.

  As the coating method of the hard coat layer coating solution, the above-described methods can be used. The coating amount is suitably 0.1 to 40 μm, preferably 0.5 to 30 μm, as the wet film thickness. Moreover, as a dry film thickness, it is an average film thickness of 0.1-30 micrometers, Preferably it is 1-20 micrometers.

  The hard coat layer is preferably irradiated with ultraviolet rays after coating and drying, and the irradiation time for obtaining the necessary amount of active light irradiation is preferably about 0.1 second to 1 minute, and the curing efficiency of the ultraviolet curable resin Or from the viewpoint of work efficiency, 0.1 to 10 seconds is more preferable.

[Transparent film substrate]
The base film used for the production of the hard coat film of the present invention is preferably easy to produce, optically isotropic, such as a hard coat layer, and optically transparent.

  Any of the above-mentioned properties may be used, for example, cellulose ester films such as cellulose diacetate film, cellulose acetate butyrate film, cellulose triacetate film, polyester film, polycarbonate film, polyarylate film, polysulfone. Film (including polyethersulfone), polyester film such as polyethylene terephthalate, polyethylene naphthalate, polyethylene film, polypropylene film, cellophane, polyvinylidene chloride film, polyvinyl alcohol film, ethylene vinyl alcohol film, syndiotactic polystyrene film, Norbornene resin film, polymethylpentene film, polyetherketone film Arm, polyether ketone imide film, a polyamide film, a fluororesin film, a nylon film, a cycloolefin polymer film, polymethyl methacrylate film or there may be mentioned acrylic film or the like, but are not limited to. Among these, cellulose ester films (for example, Konica Minoltak KC8UX2M, KC4UX2M, KC4UY, KC8UT, KC5UN, KC12UR, KC8UCR-3, KC8UCR-4 (above, manufactured by Konica Minolta Opto), polycarbonate film, polysulfone (Polysulfone) A film containing ether sulfone) and a cycloolefin polymer film are preferred, and particularly preferred is a polyester-based film from the viewpoint of better achieving the object effects of the present invention, manufacturing, cost, transparency, adhesiveness, etc. It is.

  Moreover, it is preferable that the transparent film base material of this invention is what is provided with the easily bonding layer on one side or both surfaces. The presence of the easy-adhesion layer can improve the adhesion between the transparent film substrate and the hard coat layer, or the transparent film substrate and the display device.

  The thickness of the easy adhesion layer is preferably 10 to 200 nm, more preferably 20 to 150 nm. If the thickness of the easy-adhesion layer is less than 10 nm, the effect of improving the adhesion is poor, and if it exceeds 200 nm, cohesive failure of the easy-adhesion layer tends to occur and the adhesion may be lowered.

  As the constituent material of the easy-adhesion layer, it is preferable that the material has excellent adhesion to the polyester film. Specifically, for example, polyester resin, acrylic resin, urethane acrylic resin, silicon acrylic resin, melamine resin, polysiloxane resin. Can be used. These resins may be used alone or as a mixture of two or more.

(Adhesive layer)
The pressure-sensitive adhesive layer applied to the hard coat film according to this embodiment is for attaching a film in which the hard coat layer is formed on a transparent film substrate to a display device or the like.

  The pressure-sensitive adhesive used in the pressure-sensitive adhesive layer of the present invention is not particularly limited as long as it is a known pressure-sensitive adhesive for applying a hard coat film. From an acrylic pressure-sensitive adhesive, a silicone pressure-sensitive adhesive, a urethane pressure-sensitive adhesive, and a rubber pressure-sensitive adhesive. It is preferable that it contains at least one selected.

  As the pressure-sensitive adhesive used in the pressure-sensitive adhesive layer used in the present invention, the known acrylic, silicone-based, urethane-based, and rubber-based pressure-sensitive adhesive resins can be used. Among these, an acrylic copolymer containing a (meth) acrylate monomer having an alkyl group having 2 to 14 carbon atoms as a repeating unit as a main monomer component is preferable from the viewpoint of light resistance and heat resistance.

  Among these, alkyl methacrylate having an alkyl side chain having 4 to 9 carbon atoms or alkyl acrylate having an alkyl side chain having 4 to 9 carbon atoms is preferable, and alkyl acrylate having an alkyl side chain having 4 to 9 carbon atoms. Is more preferable. By using an alkyl (meth) acrylate having an alkyl side chain with a carbon number within the range, it is easy to ensure a suitable adhesive force.

  Hereinafter, the present invention will be described more specifically by way of examples. However, the present invention is not limited to the examples.

(Example 1)
A polyester film having a length of 2600 m, a width of 1.4 m, and a film thickness of 100 μm was produced as follows. The transparent long base film was provided with a first knurling portion as shown below. Next, a hard coat layer was provided on one surface of the polyester film to produce a hard coat film of Example 1.

<Production of polyester film>
Polyethylene terephthalate (PET) resin was melted at 290 ° C. with an extruder, extruded into a sheet form from a T-die, and cooled with a cast drum. Thereafter, the unstretched film was stretched in the longitudinal direction using a roll stretching apparatus at a stretching temperature of 120 ° C. and a stretching ratio of 5 times. Subsequently, after applying an easy-contact layer to the obtained longitudinally stretched film, it was dried and stretched in the transverse direction at a stretching temperature of 110 ° C. and a stretching ratio of 3.0 times with a transverse stretching apparatus to produce a polyester film.

<Coating of hard coat layer>
The following hard coat layer composition was die coated on one surface of the polyester film, dried at 80 ° C. for 5 minutes, and then provided with a hard coat layer so as to irradiate with 160 mJ / cm ² of ultraviolet light, thereby producing a hard coat film.

<< Hardcoat layer composition >>
The following materials were stirred and mixed to obtain a hard coat layer coating composition.

Pentaerythritol tri / tetraacrylate
(NK Ester A-TMM-3L, Shin-Nakamura Chemical Co., Ltd.) 100 parts by mass Irgacure 184 (Ciba Japan Co., Ltd.) 2 parts by mass Polyether-modified polydimethyl siloxane (BYK-UV3510, manufactured by Big Chemie Japan Co., Ltd.) ) 1 part by mass Cyclohexanone 10 parts by mass Methyl ethyl ketone 93 parts by mass The elastic modulus of this hard coat layer was measured to be 5.5 GPa.

<< Production of knurling part >>
The heated embossing roll is pressed against both ends of the hard coat film produced as described above, and the convex portion is formed on the surface opposite to the side on which the hard coat layer of the polyester film is formed (the back surface is convex). So that the knurling part is 70 per 1 cm ² . At this time, the embossing height was 7 μm and the width was 15 mm.

  In addition, the embossing height in a present Example is the height remove | excluding the film thickness of the polyester film and hard coat film before knurling part formation from the convex part total thickness of an embossed part.

(Example 2)
A hard coat film of Example 2 was produced in the same manner as in Example 1 except that 20 pieces per 1 cm ^{2 of the} knurling part were used.

(Example 3)
A hard coat film of Example 3 was produced in the same manner as in Example 1 except that the knurling part was arranged to be 140 pieces per 1 cm ² .

(Comparative Example 1)
In Example 1, the hard coat film was not laminated, and Comparative Example 1 was used.

(Comparative Example 2)
A hard coat film of Comparative Example 2 was produced in the same manner as in Example 3 except that the elastic modulus of the hard coat layer was 4.5 GPa.

(Comparative Example 3)
A hard coat film was produced in the same manner as in Example 3. However, the knurling part was so formed as to be recessed (the back surface was concave) with respect to the surface of the polyester film opposite to the side on which the hard coat layer was formed. This was designated as Comparative Example 3.

(Comparative Example 4)
A hard coat film of Example Comparative Example 4 was produced in the same manner as in Example 1 except that the knurling part had a density of 70 per 1 cm ² .

(Comparative Example 5)
A hard coat film of Comparative Example 5 was produced in the same manner as in Example 1 except that the knurling part was produced so that the density was 160 per 1 cm ² .

  The following evaluation was performed on each of the above sheets.

<Evaluation>
<Anti-back effect prevention of adhesive>
Back of the liquid when wire bar coating was applied on the opposite side of the hard-coated surface of the single-sided hard-coated film substrate with an adhesive of 25 g / m ² of acrylic adhesive having a viscosity of 100 (mPa · s / 25 ° C.) The presence or absence of surroundings was confirmed.

A: No back circumference is generated and wetting spread is less than 30% of the width of the knurling portion.
○: No back circumference is generated, and wetting spread is 30% or more and less than 100% of the width of the knurling portion.
X: The back circumference occurred due to wet spreading.

<Emboss height after winding the hard coat film>
The embossed height after winding up the hard coat film was measured with a contact-type desktop thickness measuring device (manufactured by Yamabun Electric Co., Ltd.).

  The above results are shown in Table 1 below.

[Discussion]
From the results in Table 1, a hard coat layer having an elastic modulus of 5.0 GPa or more was formed, and the convex part of the knurling part was applied to the surface of the transparent film substrate opposite to the side on which the hard coat layer was formed. It was revealed that the hard coat films of Examples 1 to 3 were able to suppress the back of the adhesive. In particular, when the density of the knurling part is 70 pieces / cm ² (Example 1), when the density is 140 pieces / cm ² (Example 3), and 20 pieces / cm ² (Example 2). In comparison, it was found that the knurling part was not crushed even after winding, and the deterrent effect around the liquid back was excellent.

  On the other hand, Comparative Example 1 that does not have a knurling part that is not laminated with a hard coat layer as in the present invention has no convex part on the surface on the opposite side of the hard coat surface, and therefore prevents the liquid back around at all. I couldn't. In addition, although the hard coat layer was laminated, when the elastic modulus of the hard coat layer was smaller than 5 GPa (Comparative Example 2), the knurling portion collapsed when the hard coat film was wound, and the adhesive The back of the agent could not be prevented.

  Also, the back of the pressure-sensitive adhesive was not applied to the back side of Comparative Example 3 in which a non-convex knurling portion was formed on the surface opposite to the side on which the hard coat layer of the transparent film substrate was formed. Since there was no convex knurling part that dammed the surface, the back of the adhesive could not be suppressed.

Further, when the density of the knurling part was 5 pieces / cm ² (Comparative Example 4), the knurling part was crushed when the hard coat film was wound, and the back of the adhesive could not be prevented. . Furthermore, when the density of the knurling portion was 160 pieces / cm ² (Comparative Example 5), only a height of 2 μm could be obtained during knurling, and the back of the adhesive could not be prevented.

Claims (7)

A hard coat film in which a hard coat layer having an elastic modulus of 5.0 GPa or more is formed on one surface of a transparent film substrate,
At both ends of the hard coat film, 10 to 140 knurling irregularities are applied to the surface on the hard coat layer side per cm ² ,
The convex part of the knurling part is given to the surface opposite to the side where the hard coat layer was formed of the transparent film base so as to correspond to the concave part given to the hard coat layer. Hard coat film. The hard coat film according to claim 1, further comprising an adhesive liquid layer on a surface opposite to the side on which the hard coat layer is provided.   The hard coat film according to claim 2, wherein the pressure-sensitive adhesive layer contains at least one selected from an acrylic pressure-sensitive adhesive, a silicone-based pressure-sensitive adhesive, a urethane-based pressure-sensitive adhesive, and a rubber-based pressure-sensitive adhesive.   The hard coat film according to claim 1, wherein the hard coat layer contains at least one polyfunctional (meth) acrylate. The hard coat film according to claim 4, wherein the polyfunctional (meth) acrylate is an isocyanuric acid-modified acrylate.   The hard coat film according to claim 1, wherein the transparent film substrate has an elastic modulus of 3.0 to 4.5 GPa.   The hard coat film according to claim 1, wherein the transparent film substrate is a polyester film with an easy adhesion layer.

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