KR20140029179A - Method for producing icon sheet, icon sheet, and touch panel using the same - Google Patents

Abstract

The present invention provides an icon sheet having less optical distortion due to a print step difference, less remaining bubbles, less dent by weight, and a less delaminated adhesive layer and a method of fabricating the same. A method of fabricating an icon sheet at least includes: forming a print layer including a frame and/or an icon through printing on one side or both sides of a base material and one side of hard coat film forming a hard coat layer; preparing an adhesive film where an adhesive layer is formed on a corresponding delamination processing surface of a delamination processed delamination film; laminating a photo-curable resin layer by coating a photo-curable resin composition having a fluidity on an upper part of a portion having no print layer of a side for forming the print layer of the hard coat film and an upper part of the print layer; bonding an adhesive film on the photo-curable resin layer by interposing the adhesive layer therebetween; and hardening the photo-curable resin layer by irradiating light on the photo-curable resin layer.

Description

TECHNICAL FIELD [0001] The present invention relates to a method of manufacturing an icon sheet, an icon sheet, and a touch panel using the icon sheet,

The present invention relates to a method of producing an icon sheet having a print layer and a pressure-sensitive adhesive layer on one side of a hard-coated film, an icon sheet obtained thereby, and a touch panel using the same.

In the present specification, the printing step refers to the thickness of the printing layer from the substrate surface in a state in which the printing layer of the black frame and / or icon is formed on the surface of the substrate made of the transparent resin film.

2. Description of the Related Art A touch panel is conventionally known in which a hard coat film on which an icon indicating an operation method is printed on the surface of a touch panel is stuck (see, for example, Patent Documents 1 and 2).

As a display (display apparatus) to which a touch panel is applied, a liquid crystal display (LCD), an electroluminescent display (inorganic EL, organic EL), etc. are mentioned, As a specific electronic apparatus which this touch panel is used, a liquid crystal television , A mobile terminal, a mobile phone, an electronic paper, an electronic book terminal, a personal computer, and the like.

However, in Patent Document 1, when the hard coat film on which the icon is printed is adhered with the pressure-sensitive adhesive, if the step between the printed portion of the icon and the periphery thereof is set to 5 μm or less, generation of bubbles .

Various attempts have been made to prevent the incorporation of air bubbles caused by the existence of the printing step of the icon in adhering the hard coat film on which the icon indicating the operation method is printed on the surface of the touch panel For example, see Patent Documents 3 to 7).

Patent Documents 8 and 9 disclose a manufacturing method of an image display panel in which a decorative layer is formed on the back surface of a viewable panel substrate that forms an image display. In a state in which an ultraviolet curing resin or a thermosetting resin is continuously filled on the inner side of the step of the decorative layer on the back surface of the panel substrate and the top surface of the decorative layer and then a separator film coated with a release agent on the upper surface of the curing resin, The film is pressed to the side of the cured resin and UV irradiation is performed, and then the separator film is peeled off to manufacture an image display panel.

A technique of laminating a photocurable resin in two layers and curing the same at the same time is disclosed in, for example, Patent Documents 10 to 12.

Japanese Laid-Open Patent Publication 2003-036143 Japanese Laid-Open Patent Publication 2004-213187 Japanese Unexamined Patent Publication No. 2009-098324 Japanese Unexamined Patent Publication No. 2010-176111 Japanese Unexamined Patent Publication No. 2010-072471 Japanese Unexamined Patent Publication No. 2010-097070 Japanese Unexamined Patent Publication No. 2010-239324 Japanese Laid-Open Patent Publication 2012-22281 Japanese Laid-Open Patent Publication 2012-22210 Japanese Unexamined Patent Publication No. 2000-248241 Japanese Patent Application Laid-Open No. 2004-204090 Japanese Unexamined Patent Publication No. H1-11-1386

However, in the display device described in Patent Document 3, it is necessary to add a translucent member (corresponding to a hard coat film) to the surface of the touch panel through the adhesive layer and the pressure-sensitive adhesive layer, And it could not be employed for an inexpensive display device. Moreover, in the display apparatus of patent document 3, although the light shielding layer of thickness about 5-10 micrometers is formed so that the outer periphery of a liquid crystal device may be formed, an adhesive bond layer and an adhesive layer are not so influenced by the printing step of a light shielding layer. The area of is excreted.

In addition, Patent Document 4 discloses that a step between a transparent protective plate made of an acrylic resin or a polycarbonate resin and a printing portion is filled with a transparent resin to be flattened, and that the protective plate is bonded to the display surface with a double-sided tape or an adhesive having transparency. have.

According to patent document 4, it is said that it is preferable to make the film thickness of photocurable resin into the film thickness twice or more of the thickness of a printing layer, but the detail of the planarization method performed using photocurable resin is not described in detail.

In addition, Patent Document 5 discloses bonding a surface protective layer (corresponding to a protective film) having a light shielding layer (corresponding to a printed layer of an icon) on the surface of a touch panel via an adhesive layer having a specific storage elastic modulus. . When the pressure-sensitive adhesive layer is used, the pressure-sensitive adhesive layer is not formed. However, after the surface protective layer is bonded to the touch panel, the pressure-sensitive adhesive is cured by irradiating ultraviolet rays from the surface protective layer or the opposite side of the touch panel. However, Is not sufficiently irradiated with ultraviolet rays.

In addition, Patent Document 6 discloses bonding a surface transparent plate (corresponding to a protective film) having a black printing layer (corresponding to a printing layer of an icon) on the surface of a touch panel via a transparent adhesive sheet having a specific storage elastic modulus. It is.

It is supposed that bubbles are not generated in the adhesive surface between the liquid crystal display panel and the plastic plate (protective transparent plate). However, since the protective transparent plate made of transparent plastic is adhered to the liquid crystal panel via the transparent adhesive sheet, there is a problem that bubbles can not be remained in the corner portion where the step of the black print layer occurs.

In addition, Patent Document 7 discloses bonding a design panel having an outer frame to a touch panel via a double-sided tape.

Since the bonding surface of a double-sided tape becomes substantially planar as a whole, it is said that an air bubble does not arise between a design panel and a double-sided tape. However, since the design panel is bonded to the touch panel via the double-sided tape, there is a problem that bubbles remain in the corner portion where the step of the print layer of the outer frame portion occurs.

Further, the image display panel disclosed in Patent Documents 8 and 9 can reduce the generation of bubbles, but there is a problem that when the load is applied to the panel, the panel is prone to sag.

The inventions disclosed in Patent Documents 10 to 12 all relate to a pressure-sensitive adhesive film or a pressure-sensitive adhesive tape, and disclose that the base material and the pressure-sensitive adhesive layer are cured at the same time. However, in these cases, the base layer needs to be thicker than the pressure-sensitive adhesive layer in order to impart stress relievability and the like to the tape. Therefore, the viscosity of the resin composition solution of the base layer is made higher than the viscosity of the pressure- have.

Therefore, in the case where the upper portion of the portion of the hard coat film on which the print layer is not coated is filled with the highly viscous resin composition using the invention disclosed in Patent Documents 10 to 12, in the corner portion where the step of the print layer occurs, Can not be avoided.

Further, in the case of producing an icon sheet having a print layer and a pressure-sensitive adhesive layer on one side of a hard coat film other than the problem of generation of bubbles, the pressure-sensitive adhesive layer previously laminated on the release film is knotted There is a problem that the adhesive strength of the pressure-sensitive adhesive layer is lowered and the pressure-sensitive adhesive layer is liable to be peeled off under a high-humidity heat environment.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide an icon sheet production method in which optical distortion caused by a printing step is small, bubble remains unremoved, dents do not occur even when a load is applied, , Icon sheet and touch panel using it.

In order to solve the above problems, the present invention provides a method for producing an icon sheet having a print layer and a pressure-sensitive adhesive layer on one side of a hard-

Step (1): A hard coat film in which a hard coat layer is formed on one side or both sides of a substrate is used. When a hard coat layer is formed on one side, a hard coat layer is formed on the other side A step of forming a print layer made of a frame and / or an icon on one side by printing,

Step (2): a step of preparing an adhesive film having a pressure-sensitive adhesive layer formed on the exfoliated surface of the exfoliated film,

Step (3): A photocurable resin composition having fluidity is applied to an upper portion of a portion of the hard coat film on which the print layer is formed, on which the print layer is not coated, and an upper portion of the print layer, ,

Process (4): The process of pasting the adhesive film in which the adhesive layer was formed in the said peeling process surface of the peeling process film which was prepared previously on the said photocurable resin layer via the said adhesive layer,

Step (5): a step of curing the photo-curable resin layer by irradiating light to the photo-curable resin layer

The icon sheet having at least the following characteristics: < tb > < TABLE >

Moreover, this invention is a manufacturing method of the icon sheet which has a printing layer and an adhesive layer in one side of a hard-coat film,

Step (1): A hard coat film in which a hard coat layer is formed on one side or both sides of a substrate is used. When a hard coat layer is formed on one side, a hard coat layer is formed on the other side A long roll of a hard coat film in which a print layer made of a frame and / or an icon is formed on one side by printing,

Step (2): a step of preparing a long roll of an adhesive film having a pressure-sensitive adhesive layer formed on the exfoliated surface of the exfoliated film,

Step (3): While the long roll of the hard coat film is unwound and unwound, the upper surface of the portion of the hard coat film on which the print layer is formed, on which the print layer is not coated, A step of laminating a photocurable resin layer by applying a photocurable resin composition having flowability,

Step (4): a step of bonding the adhesive film unwound while winding the long roll of the adhesive film on the photo-curable resin layer with the adhesive layer interposed therebetween,

Step (5): a step of curing the photo-curable resin layer by irradiating light to the photo-curable resin layer

The icon sheet having at least the following characteristics: < tb > < TABLE >

Further, the present invention provides an icon sheet obtained by the method for producing an icon sheet.

Further, the present invention provides a touch panel in which the icon sheet is bonded via the pressure-sensitive adhesive layer.

In addition, the present invention provides an electronic apparatus in which a touch panel is embedded.

The manufacturing method of the icon sheet of this invention is a process (1): when using the hard-coat film which provided the hard-coat layer in one side or both surfaces of a base material, and forming a hard-coat layer in one side, the other side In the case where the hard coat layer is formed on both sides, a step of forming a printed layer made of a frame and / or an icon on either side by printing;

Step (2): a step of preparing an adhesive film having a pressure-sensitive adhesive layer formed on the exfoliated surface of the exfoliated film,

Step (3): A photocurable resin composition having fluidity is applied to an upper portion of a portion of the hard coat film on which the print layer is formed, on which the print layer is not coated, and an upper portion of the print layer, ,

Process (4): The process of pasting the adhesive film in which the adhesive layer was formed in the said peeling process surface of the peeling process film which was prepared previously on the said photocurable resin layer via the said adhesive layer,

Step (5): a step of curing the photo-curable resin layer by irradiating light to the photo-curable resin layer

Since the structure which has at least, it has little distortion of a printing step, there are few bubbles | survives of foam | bubble, it is hard to produce a recession with respect to a load, and an icon sheet in which an adhesive layer does not peel easily can be manufactured efficiently.

Further, the icon sheet of the present invention can be suitably used as a scattering-preventive film, particularly as an icon sheet to be laminated on the ITO surface of a capacitive touch panel.

1 is a sectional view showing an example of an icon sheet of the present invention.

EMBODIMENT OF THE INVENTION Hereinafter, preferable embodiment of this invention is described.

A method for producing an icon sheet of the present invention is a method for producing an icon sheet having a print layer and a pressure-sensitive adhesive layer on one side of a hard coat film,

Step (1): A hard coat film in which a hard coat layer is formed on one side or both sides of a substrate is used. When a hard coat layer is formed on one side, a hard coat layer is formed on the other side A step of forming a print layer made of a frame and / or an icon on one side by printing,

Step (2): a step of preparing an adhesive film having a pressure-sensitive adhesive layer formed on the exfoliated surface of the exfoliated film,

Step (3): A photocurable resin composition having fluidity is applied to an upper portion of a portion of the hard coat film on which the print layer is formed, on which the print layer is not coated, and an upper portion of the print layer, ,

Process (4): The process of pasting the adhesive film in which the adhesive layer was formed in the said peeling process surface of the peeling process film which was prepared previously on the said photocurable resin layer via the said adhesive layer,

Step (5): a step of curing the photo-curable resin layer by irradiating light to the photo-curable resin layer

At least.

Moreover, the manufacturing method of the icon sheet of this invention is a manufacturing method of the icon sheet which has a printing layer and an adhesive layer in one side of a hard-coat film,

Process (1): When using the hard-coat film which provided the hard-coat layer on one side or both sides of the base material, and forming a hard-coat layer on one side, a hard-coat layer is formed on both sides on the other side, If there is, the process of preparing the elongate roll body of the hard-coat film which provided the printing layer which consists of a frame and / or an icon by printing on either surface,

Step (2): a step of preparing a long roll of an adhesive film having a pressure-sensitive adhesive layer formed on the exfoliated surface of the exfoliated film,

Step (3): While the long roll of the hard coat film is unwound and unwound, the upper surface of the portion of the hard coat film on which the print layer is formed, on which the print layer is not coated, A step of laminating a photocurable resin layer by applying a photocurable resin composition having flowability,

Step (4): a step of bonding the adhesive film unwound while winding the long roll of the adhesive film on the photo-curable resin layer with the adhesive layer interposed therebetween,

Step (5): a step of curing the photo-curable resin layer by irradiating light to the photo-curable resin layer

At least.

(Hard coat film)

The hard coat film used in the method for producing an icon sheet of the present invention is one having a hard coat layer on one or both sides of a transparent resin film to be a substrate.

The transparent resin film is preferably one selected from the group consisting of a polyethylene terephthalate (PET) resin film, a polyethylene naphthalate (PEN) resin film and a cyclic polyolefin (COP) Do. In particular, a polyethylene terephthalate (PET) resin film is suitably used in view of relatively low price and high transparency.

10-250 micrometers is preferable and, as for the thickness of a transparent resin film, 30-200 micrometers is more preferable. When the thickness of a transparent resin film is thinner than 10 micrometers, since handleability is lacking, it is not preferable. Moreover, when the thickness of a transparent resin film is thicker than 250 micrometers, transparency falls, cost becomes high, and processing suitability in the manufacturing process of a hard coat film worsens, and it is unpreferable. From the above point, 10-250 micrometers is preferable and, as for the thickness of a transparent resin film, 30-200 micrometers is more preferable. Further, for the purpose of improving the adhesion between the transparent resin film and the hard coat layer, even if a resin layer having an appropriate adhesion property is laminated on the surface of the transparent resin film, or a surface treatment such as a flame treatment, a corona treatment or a plasma treatment is performed do. Moreover, you may form a base layer between a transparent resin film and a hard-coat layer.

(Hard coat layer)

The hard coat layer to be formed on the transparent resin film is required to have a hard coat property so as to be usable as a surface material of the touch panel, and there is no practical problem if the measured value is usually 2H or more in the pencil hardness test. There is no restriction | limiting in particular in resin used for a hard-coat layer, Thermosetting hard-coat resin, such as silicone type and a melamine type, UV-curable hard coat resin, such as silicone type, an acryl type, etc. can be used. In the hard coat film of the present invention, a hard coat layer is formed on one side or both sides of the transparent resin film. In the case where the hard coat layer is formed on only one side of the transparent resin film, warpage or deformation due to thermal expansion tends to occur, so that the cost is prioritized over the performance, except that a cheap hard coat film is required. It is preferable to form a hard coat layer on both surfaces of a film.

Moreover, 1-10 micrometers is preferable and, as for the thickness of a hard-coat layer, 2-8 micrometers is more preferable. When the thickness of the hard coat layer is thinner than 1 µm, hard coat properties cannot be obtained, and scratch resistance is reduced, and curing failure is easily caused when an ultraviolet curable hard coat resin is used.

If the thickness of the hard coat layer is larger than 10 mu m, cracks tend to occur in the hard coat layer, and the hard coat film itself tends to cause curling, which is not preferable.

In addition, you may add the additive for providing various functions, such as an antistatic agent and a ultraviolet absorber, to a hard-coat layer as needed. As a method of forming a hard coat layer on the surface of a transparent resin base material, the conventionally well-known method, such as a reverse coat method, the die coat method, and the gravure coat method, can be used.

When the printing layer and the pressure-sensitive adhesive layer are laminated on the hard-coat layer, for the purpose of improving the adhesion between the hard-coat layer, the printing layer and the pressure-sensitive adhesive layer, Or may be subjected to surface treatment such as flame treatment, corona treatment, or plasma treatment.

(Printed layer of black frame and / or icon)

The present invention relates to a method for producing an icon sheet having a printing layer and an adhesive layer on one side of a hard coat film.

In the icon sheet according to the present invention, the black frame formed by the printing layer suppresses the leakage of the illumination light emitted from the display panel (the backlight of the liquid crystal panel or the like) provided behind the touch panel from the periphery of the display panel , It is provided for shielding the peripheral portion of the display panel. In addition, the icons formed by the printed layer are fixedly frequently used among icons (displays of patterns, characters, symbols, etc. for inputting or selecting specific functions, operations, items, etc.) displayed on the screen of the touch panel. It is installed to display.

Formation of the black frame and / or icon by a printing layer is performed by apply | coating and drying the coating material which consists of a resin composition containing a light-shielding black pigment by screen printing, intaglio printing, etc., and forming a light-shielding film. As the black pigment, one or more compounds selected from the group consisting of carbon black, graphite, aniline black, cyanine black, titanium black, black iron oxide, chromium oxide, and manganese oxide may be used in combination. Of these black pigments, particularly carbon black is suitably used. The distribution range of the preferable particle diameter of a black pigment (light absorbing material) is the range of 0.01-0.5 micrometer, More preferably, it is the range of 0.05-0.3 micrometer. On the other hand, in order to adjust the color tone of the light-shielding layer to an achromatic color or a preferable color tone, a plurality of different coloring materials may be used as needed. In addition, in order to form a black frame by a printing layer, for example, the black frame can be formed by using the acrylic resin paint which disperse | distributed carbon black as a black pigment, and making the film thickness of a printing layer into 10-50 micrometers. Can be. It is not necessary to limit this print layer to black, and it is possible to select various colors, such as glossy resin, white, and various hue colors.

(Photocurable pressure-sensitive adhesive composition)

In the method for producing the icon sheet of the present invention, the photocurable pressure-sensitive adhesive composition used for forming the pressure-sensitive adhesive layer is not particularly limited.

Examples of the photocurable pressure-sensitive adhesive composition include a photocurable pressure-sensitive adhesive composition of an acrylic syrup type having an acrylic polymer, an acrylic monomer and a photopolymerization initiator as essential components, or a subject comprising a urethane acrylate polymer and / or a urethane acrylate A photo-curable pressure-sensitive adhesive composition of urethane acrylic type prepared by adding a crosslinking agent, an additive, etc., as necessary, with an acrylic monomer and a photopolymerization initiator as essential components can be used.

These photocurable pressure-sensitive adhesive compositions exhibit tackiness at the time of photo-curing and solidify to become a pressure-sensitive adhesive layer.

The photocurable pressure-sensitive adhesive composition of the acrylic syrup type contains a step of rapidly terminating the polymerization by cooling or introducing oxygen, or volatilizing the organic solvent used in the polymerization, so that it is more preferable to obtain a stable composition than the urethane acrylic photocurable pressure- it's difficult. For this reason, a urethane acrylic photocurable adhesive composition is preferred.

As the urethane acrylate which is the main component of the photocurable resin composition, for example, there can be used one or more compounds having one or more hydroxyl group-containing acrylic monomers obtained by reacting two or more hydroxyl group-containing acrylic monomers with one mole of a compound having two or more NCO groups in one molecule, (Meth) acrylic group. Examples of the hydroxyl group-containing acrylic monomer include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, polyethylene glycol mono (Meth) acrylate having a hydroxyl group such as poly (meth) acrylate, polypropylene glycol mono (meth) acrylate and cyclohexanedimethanol mono (meth) acrylate.

Moreover, as a compound which has two or more NCO groups in 1 molecule, the oligomer whose molecular weight obtained by making polyisocyanate compounds, such as diisocyanate, and polyol compounds, such as a diol, react is about 500-50000 is preferable.

Examples of the polyisocyanate compound include aliphatic polyisocyanates such as hexamethylene diisocyanate and isophorone diisocyanate, and aromatic polyisocyanates such as tolylene diisocyanate, xylylene diisocyanate, diphenylmethane diisocyanate and phenylene diisocyanate.

Examples of the polyol compound include glycols such as ethylene glycol, propylene glycol, tetramethylene glycol, hexamethylene glycol, neopentyl glycol and 1,4-cyclohexanedimethanol; polyols having three or more hydroxyl groups such as glycerin and pentaerythritol; A polyether diol such as polyethylene glycol, polypropylene glycol, polytetramethylene glycol and polyhexamethylene glycol; a polyether-type diol such as polyether-type diol such as polyether-type diol obtained by reacting the diol with a dibasic acid such as phthalic acid, isophthalic acid, terephthalic acid, maleic acid, fumaric acid, adipic acid, Ester type diols and the like.

In the photocurable resin composition, at least one of (meth) acrylates may be contained in at least one of the urethane acrylates. Other monomers may also be added as long as the effects of the present invention are not impaired. As the (meth) acrylate, for example, alkyl represented by the general formula CH ₂ = CR ¹ -COOR ² (wherein R ¹ represents hydrogen or a methyl group and R ² represents an alkyl group having 1 to 14 carbon atoms) Acrylic monomers, such as meth) acrylate, are mentioned. Specific examples of the alkyl (meth) acrylate represented by the general formula CH ₂ ═CR ¹ -COOR ² include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) (Meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, t- (meth) acrylate, n-hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, isooctyl And dodecyl (meth) acrylate. These may be used alone or in combination of two or more. Among these, 2-ethylhexyl (meth) acrylate and n-butyl (meth) acrylate are used preferably. In addition, these alkyl groups R ² may be linear or branched. In addition, as a non-acrylic-type monomer containing an alkoxy silyl group, vinyl methoxysilane, vinyl trimethoxysilane, etc. are mentioned, for example.

In addition, various compounds such as non-acrylic monomers can be used. As for the addition monomer, the monofunctional monomer which has one photopolymerizable group, such as a (meth) acryl group and a vinyl group, per molecule is preferable.

The photo-curable resin composition usually contains at least one kind of acrylic monomer as a diluent for lowering the viscosity at the time of coating. However, since it is necessary to increase the amount of UV irradiation when an acrylic monomer component is added excessively, The addition amount is preferably 50 mass% or less, more preferably 30 mass% or less of the resin component.

Moreover, when an organic solvent remains in resin, the residual organic solvent may cause fouling with respect to the printing layer of the hard-coat film in which the printing layer of the black frame was formed. Therefore, it is necessary to raise solvent resistance in advance for the coating material of the printing layer using a UV curing agent or a crosslinking agent.

Moreover, since urethane acrylate type UV curable resin and an acrylic syrup add polymerization photopolymerization initiator and the ultraviolet light contained in room light or sunlight acts on an acrylic syrup, a polymerization reaction may advance and management becomes difficult, It is preferable to add a photoinitiator just before possible as soon as possible of the application | coating process which is a subsequent process. This is similarly handled in the resin solution in which the acrylic syrup is dissolved in the organic solvent, and care should be taken to prevent the photopolymerization initiator from starting the reaction before coating or film forming due to any external factor.

The photopolymerization initiator (polymerization catalyst) used in the photocurable resin composition is not particularly limited, and examples thereof include an acetophenone photopolymerization initiator, a benzoin photopolymerization initiator, a benzophenone photopolymerization initiator, a thioxanthone photopolymerization initiator, Based photopolymerization initiator and the like.

Examples of the acetophenone-based photopolymerization initiator include acetophenone, p- (tert-butyl) 1 ', 1', 1'-trichloroacetophenone, chloroacetophenone, 2 ', 2'-diethoxyacetophenone, Phenone, 2,2-dimethoxy-2'-phenylacetophenone, 2-aminoacetophenone, dialkylaminoacetophenone and the like.

As a benzoin type photoinitiator, benzyl, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy 2-methyl -1-phenyl-2-methylpropan-1-one, 1- (4-isopropylphenyl) -2-hydroxy 2-methylpropan-1-one, benzyl dimethyl ketal and the like.

Examples of the benzophenone-based photopolymerization initiators include benzophenone, benzoylbenzoic acid, methyl benzoyl benzoate, methyl-o-benzoylbenzoate, 4-phenylbenzophenone, hydroxybenzophenone, hydroxypropylbenzophenone, and acrylbenzophenone. X-bis (dimethylamino) benzophenone etc. are mentioned.

Examples of the thioxanthene photopolymerization initiator include thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, diethylthioxanthone, and dimethylthioxanthone.

Other examples of the photopolymerization initiator include? -Acyloxime esters, benzyl- (o-ethoxycarbonyl)? -Monooxime, acylphosphine oxide, glyoxyester, 3-ketocmarine, Camphorquinone, tetramethylthiuramsulfide, azobisisobutyronitrile, benzoyl peroxide, dialkyl peroxide, and tert-butyl peroxypivalate.

One type of these photoinitiators may be used and may use two or more types together. The content of the photopolymerization initiator is preferably 0.005 to 5 mass%, particularly preferably 0.01 to 2 mass%, based on 100 mass% of the total amount of the polymerizable compound. When the content of the photopolymerization initiator is 0.005 mass% or more, the polymerizable compound can be polymerized in a short period of time. When the content is 5 mass% or less, the photopolymerization initiator remains in the cured product.

In the photocurable resin composition, a crosslinking agent may be added to crosslink the acrylic polymer as an optional component. The number of groups of the functional group contained in the crosslinking agent is selected by the physical properties of the required pressure-sensitive adhesive composition, and it is possible to adjust the addition amount of the crosslinking agent as necessary.

It will not specifically limit, if it is a compound which has two functional groups which carry out crosslinking reaction in 1 molecule as a bifunctional crosslinking agent. As such a bifunctional crosslinking agent, a bifunctional epoxy compound, a bifunctional isocyanate, etc. are mentioned, for example.

Examples of the bifunctional epoxy compound include ethylene glycol diglycidyl ether, diethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, dipropylene glycol diglycidyl ether, Aliphatic bifunctional epoxy compounds such as polypropylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether and 1,6-hexanediol diglycidyl ether, hydrogenated bisphenol A diglycidyl ether, o- And aromatic bifunctional epoxy compounds such as phthalic acid diglycidyl ester, terephthalic acid diglycidyl ester, and resorcin diglycidyl ether. The epoxy group of the bifunctional epoxy compound can crosslink react with the carboxyl group of the acrylic polymer.

Examples of the difunctional isocyanate include aliphatic difunctional isocyanates such as hexamethylene diisocyanate and isophorone diisocyanate (IPDI), and aromatic difunctional isocyanates such as tolylene diisocyanate and diphenylmethane diisocyanate. The NCO group of the bifunctional isocyanate can crosslink react with the carboxyl group and the hydroxyl group of the acrylic polymer.

The content of the bifunctional crosslinking agent is preferably 0.5 to 3.0 parts by mass, more preferably 1.0 to 3.0 parts by mass, per 100 parts by mass of the acrylic polymer, within a range of 0.1 equivalent or less based on the crosslinking point of the acrylic polymer.

The number of functional groups is not limited to bifunctionality, and it is possible to use a crosslinking agent having three or more functionalities in order to adjust necessary physical properties (adhesion, hardness, etc.).

(Pressure-sensitive adhesive layer)

In the method for producing the icon sheet of the present invention, the resin composition constituting the pressure-sensitive adhesive layer is not particularly limited. However, in order to improve the adhesiveness with the cured resin layer formed by curing the photo-curable resin composition, It is preferable to use a resin composition of the same kind, and for example, a urethane acrylic resin composition is preferably used.

In order to laminate | stack the adhesive layer which consists of a urethane acrylic resin on a peeling film, the urethane acrylic photocurable adhesive composition which has fluidity is apply | coated to the surface of a peeling film, it irradiates light to this, photocures, and forms an adhesive layer. The method is preferred.

The urethane acrylic photocurable pressure-sensitive adhesive composition used for forming the pressure-sensitive adhesive layer contains a subject composed of a urethane acrylate polymer and / or a urethane acrylate, an acrylic monomer and a photopolymerization initiator as essential components, and a crosslinking agent, Can be used.

The photo-curable pressure-sensitive adhesive composition of the urethane acrylic type exhibits tackiness upon photo-curing and solidifies to become a pressure-sensitive adhesive layer.

The essential components of the urethane acrylate polymer and / or urethane acrylate used in the preparation of the urethane acrylic photocurable resin composition, the respective essential components of the acrylic monomer and the photopolymerization initiator, and, if necessary, the crosslinking agent, , The essential components of the urethane acrylate polymer and / or the urethane acrylate used in the preparation of the urethane acrylic photocurable resin composition for forming the layer, the respective essential components of the acrylic monomer and the photopolymerization initiator, and, if necessary, the crosslinking agent, Are prepared using the same materials.

In the pressure-sensitive adhesive layer used in the icon sheet of the present invention, it is preferable to adjust the adhesive force of the pressure-sensitive adhesive to the adherend in accordance with the adherend state, to improve the adhesion in the case where the adherend is a glass plate, to improve the durability of the pressure- It is also possible to add various additives such as a tackifier, a softener (plasticizer), a filler, an anti-aging agent, and a silane coupling agent, if necessary.

Examples of the tackifier include rosin and its derivatives, polyterpenes, terpene phenol resins, coumarone-indene resins, petroleum resins, styrene resins and xylene resins. As a softening agent, liquid polyether, glycol ester, liquid polyterpene, liquid polyacrylate, phthalic acid ester, trimellitic acid ester, etc. are mentioned, for example.

(Peeling film)

The release film used in the method for producing an icon sheet of the present invention is preferably a transparent film obtained by coating a transparent resin film so as to inspect the adhesion of dust or the like or contamination when inspecting quality after manufacturing the icon sheet of the present invention. It is preferable that the release treatment agent is applied and exfoliated. As the transparent resin film, a polyethylene terephthalate (PET) resin film is suitably used in view of its relatively low cost and high transparency. 10-250 micrometers is preferable and, as for the thickness of a transparent resin film, 30-200 micrometers is more preferable. In addition, the method of peeling process is not specifically limited, You may use the silicone type | system | group peeling agent, addition reaction type | mold silicone type | system | group peeling agent which are already widely used.

(Icon sheet)

In the icon sheet of the present invention,

Step (1): A hard coat film in which a hard coat layer is formed on one side or both sides of a substrate is used. When a hard coat layer is formed on one side, a hard coat layer is formed on the other side A step of forming a print layer made of a frame and / or an icon on one side by printing,

Step (2): a step of preparing an adhesive film having a pressure-sensitive adhesive layer formed on the exfoliated surface of the exfoliated film,

Step (3): A photocurable resin composition having fluidity is applied to an upper portion of a portion of the hard coat film on which the print layer is formed, on which the print layer is not coated, and an upper portion of the print layer, ,

Process (4): The process of pasting the adhesive film in which the adhesive layer was formed in the said peeling process surface of the peeling process film which was prepared previously on the said photocurable resin layer via the said adhesive layer,

Step (5): a step of curing the photo-curable resin layer by irradiating light to the photo-curable resin layer

Lt; / RTI >

In the step (4), a pressure-sensitive adhesive layer of a pressure-sensitive adhesive film prepared in advance is applied onto a photo-curable resin layer made of an uncured resin composition in an uncured state to form a pressure- . Subsequently, the photocurable resin layer is cured by performing step (5) and irradiating the photocurable resin layer with light. By forming a cured resin layer in this way, the mixed layer which consists of resin in which these resin materials were mixed between cured resin layer and an adhesive layer can be formed. By forming the mixed layer between the cured resin layer and the pressure-sensitive adhesive layer, the interlaminar bond strength between the cured resin layer and the pressure-sensitive adhesive layer can be increased, and peeling between the cured resin layer and the pressure-

Further, in the icon sheet of the present invention,

Step (1): A hard coat film in which a hard coat layer is formed on one side or both sides of a substrate is used. When a hard coat layer is formed on one side, a hard coat layer is formed on the other side A step of preparing a long roll of a hard coat film in which a print layer made of a frame and / or icon is formed by printing on one side,

Step (2): a step of preparing a long roll of an adhesive film having a pressure-sensitive adhesive layer formed on the exfoliated surface of the exfoliated film,

Step (3): While the long roll of the hard coat film is unwound and unwound, the upper surface of the portion of the hard coat film on which the print layer is formed, on which the print layer is not coated, A step of laminating a photocurable resin layer by applying a photocurable resin composition having flowability,

Step (4): a step of bonding the adhesive film unwound while winding the long roll of the adhesive film on the photo-curable resin layer with the adhesive layer interposed therebetween,

Step (5): a step of curing the photo-curable resin layer by irradiating light to the photo-curable resin layer

Lt; / RTI >

1 is a view showing an example of an icon sheet of the present invention.

The icon sheet 1 of the present embodiment includes a hard coat film on which a print layer 3 made of a frame and / or an icon is formed by printing on a transparent resin film 2 having a hard coat layer 7, 3, a cured resin layer 4, a pressure-sensitive adhesive layer 5, and a release film 6 are laminated in this order.

In the icon sheet (1) of the present invention, the thickness of the transparent resin film (2) is preferably in a range of 25 to 188 m, more preferably in a range of 38 to 125 m. If the thickness of the transparent resin film 2 is less than 38 mu m, there is no polyethylene terephthalate (PET) resin film for optical use, or workability in handling is remarkably deteriorated. When the thickness of the transparent resin film 2 is 188 占 퐉 or more, measures for preventing the occurrence of pencil hardness and pitting can be taken, but it is not preferable because the thickness of the final product is reduced.

The thickness of the print layer 3 is preferably in the range of 5 탆 to 60 탆, more preferably in the range of 10 탆 to 30 탆. If the thickness of the print layer 3 is smaller than 5 占 퐉, the color concealability and appearance become worse, and if the thickness of the print layer 3 is larger than 60 占 퐉, the cost is greatly increased.

The thickness of the cured resin layer 4 is preferably in the range of 3 탆 to 30 탆, more preferably in the range of 3 탆 to 15 탆. When the thickness of the cured resin layer 4 is less than 3 占 퐉, it is necessary to use a harder material in order to prevent the occurrence of indentation, but curling due to shrinkage at the time of curing becomes remarkable, which is not preferable.

Moreover, the range of 5 micrometers-30 micrometers is preferable, and, as for the thickness of the adhesive layer 5, the range of 10 micrometers-25 micrometers is more preferable. When the thickness of the pressure-sensitive adhesive layer 5 is thinner than 5 占 퐉, the pressure-sensitive adhesive force and holding force are lowered. When the thickness of the pressure-sensitive adhesive layer 5 is larger than 30 占 퐉, thinning of the thin film can not be achieved.

Example

Hereinafter, the present invention will be described in detail by way of examples.

<Preparation of a hard coat film having a print layer>

A hard coat film (trade name: HC7125F-TP, manufactured by DIC Co., Ltd.) having a hard coat layer formed on both surfaces thereof was used as a transparent resin film, and a polyethylene terephthalate (PET) resin film having a thickness of 125 탆 was used. A black pigment-based ink (HAC series manufactured by Seiko Dovance Co., Ltd., Conk 710 Black) was printed and dried on one surface of the hard coat film so as to have a thickness of 15 占 퐉 by drying using a silk printing machine, (About 90 mm x about 53 mm in size of the display area in the black frame) of about 115 mm x about 60 mm was formed on the hard coat film (A).

The obtained hard coat film (A) has the thickness of the printed layer of a black frame of 15 micrometers, and has the height of the level | step difference by the printed layer of a black frame (henceforth a height of a printing level | step difference).

&Lt; Preparation of optical adhesive film (OCA) &gt;

A polyethylene terephthalate (PET) resin film having a thickness of 50 占 퐉 was peeled off on one side of the surface of a polyethylene terephthalate (PET) resin film, and then a urethane acrylate UV curable pressure-sensitive adhesive composition (urethane acrylate- 470 type) was applied so as to have a thickness of 25 mu m after curing to form a pressure-sensitive adhesive layer. Further, UV irradiation was conducted in a nitrogen purge atmosphere and cured to form a transparent pressure-sensitive adhesive layer for optical use. Thereafter, the optical transparent pressure-sensitive adhesive layer was subjected to peeling treatment with silicon, and the peeled surface of a polyethylene terephthalate (PET) resin film having a thickness of 38 mu m and on which a release agent layer was formed was superimposed and bonded, (OCA) was obtained.

(Example 1)

Using the hard coat film (A), a urethane acrylic UV curable resin composition having fluidity at a portion where a black frame was not formed by a print layer and a black frame by a print layer was coated on a hard coat The film (A) was applied so that the thickness of the film (A) from the surface of the transparent resin film became 10 mu m after curing to form a UV curable resin composition layer. On the UV curable resin composition layer, a PET resin film Sensitive adhesive film is bonded via a pressure-sensitive adhesive layer so as to prevent air bubbles from entering, and then UV irradiation is performed to cure the UV-curable urethane acrylate-based resin composition to form a photo-curable resin layer, an adhesive layer and a release film An icon sheet of Example 1 was obtained.

(Example 2)

The icon sheet of Example 2 was obtained in the same manner as in Example 1 except that a urethane acrylic UV-curable resin composition having flowability different from that of Example 1 was used as the UV-curable resin composition.

(Comparative Example 1)

Using the hard coat film (A), a UV curable resin composition having a urethane acrylate type flowability was printed on the black frame formed by the print layer and the black frame formed by the print layer, (A) having a thickness of 10 탆 from the surface of the transparent resin film after curing to form a UV curable resin composition layer, followed by UV irradiation in a nitrogen purge atmosphere to cure the UV curable resin composition to form UV A curable resin layer was formed. The optical adhesive film of Example 1, in which a PET resin film having a thickness of 38 탆 was peeled off from the UV curable resin layer, was bonded via a pressure-sensitive adhesive layer so as to prevent air bubbles from entering, thereby forming a light-curable resin layer, And the icon sheet of Comparative Example 1 laminated in this order was obtained.

(Comparative Example 2)

Using the hard coat film (A), a urethane acrylic UV curable resin composition having fluidity at a portion where a black frame was not formed by a print layer and a black frame by a print layer was coated on a hard coat The film (A) was applied so as to have a thickness of 10 mu m from the surface of the transparent resin film after curing to form a UV curable resin composition layer. A polyethylene terephthalate (PET) resin film having a thickness of 38 占 퐉 was overlaid on the UV curable resin composition layer to form a UV curable urethane acrylate UV curable resin composition by curing the UV curable resin composition Strata. The optical adhesive film of Example 1, in which a PET resin film having a thickness of 38 mu m was peeled off from the UV curable resin layer, was adhered via a pressure-sensitive adhesive layer so as not to contain air bubbles, The UV curable resin composition was cured to obtain an icon sheet of Comparative Example 2 in which a photo-curable resin layer, a pressure-sensitive adhesive layer, and a release film were laminated in this order.

(Comparative Example 3)

Example 1, in which a 38 占 퐉 -thick PET resin film was peeled off from the upper part of the black frame by the print layer and the upper part of the black frame by the print layer using the hard coat film (A) The optical adhesive film was kneaded with a pressure-sensitive adhesive layer interposed therebetween so as to prevent bubbles from entering, thereby obtaining an icon sheet of Comparative Example 3 in which an adhesive layer and a release film were stacked in this order.

(Bubble confirmation examination after bonding)

Icon sheet of Example 1, 2 and Comparative Examples 1 and 2, ITO film (manufactured by Nakai Kogyo Co., Ltd., product name), which were manufactured using a bonding apparatus (manufactured by Climb Products Co., Ltd., product name: small sheetfender, model: SE320). : The operation which bonded together the ITO surface of the glass plate which adhere | attached metaforce 125R2xA and surface resistance value 250 (ohm) / m <^2> ) with the adhesive tape was performed.

(Feasibility test)

In the sample produced by the bubble confirmation test after bonding, the pencil hardness test according to K5400-1 was performed except having made the load into 1 kg. As a result, in Examples 1 and 2 and Comparative Example 1, a pencil hardness test was performed on a portion where no printing was performed, and it was found that the pencil hardness was 2H. Also, occurrence of punching on a portion rubbed with a pencil could not be visually confirmed. However, in Comparative Example 2, the pencil hardness 2H was satisfied, but the occurrence of denting was confirmed visually.

(Hot heat test)

An icon sheet of the produced Examples 1 and 2 and Comparative Examples 1 to 3 was applied to a glass plate using a kneading apparatus (manufactured by Climate Products Co., Ltd., product name: small sheet stacking machine, type: SE320).

A sample in which the icon sheet and the glass were combined was put in an environment of 85 ° C × 85% RH for 240 hours, and the interface to be peeled off after the removal was confirmed.

In the case of standing still, the icon sheets of Examples 1 and 2 and Comparative Examples 1 to 3 had no external problems such as lifting and peeling.

When the icon sheet was forcibly peeled off from the glass, the icon sheets of Examples 1 and 2 were not peeled from the interface between the coating layer and the pressure-sensitive adhesive layer. However, the icon sheets of Comparative Examples 1 and 2 were peeled from the interface between the coating layer and the adhesive layer. The icon sheet of Comparative Example 3 was peeled from the interface between the hard coat film and the pressure-sensitive adhesive layer.

The icon sheets of Examples 1 and 2 were prepared by applying a urethane acrylic photocurable resin composition having fluidity to the upper portion of a portion of the hard coat film on which the print layer was not formed and the upper portion of the print layer And an adhesive film on which a pressure-sensitive adhesive layer is formed on the exfoliated surface of the exfoliated exfoliated film previously prepared on the photocurable resin layer is bonded via the pressure-sensitive adhesive layer, Curable resin layer, and the photo-curable resin layer, the pressure-sensitive adhesive layer, and the release film are stacked in this order.

The icon sheet obtained in Examples 1 and 2 could be bonded without causing the occurrence of air bubbles in a portion where there is a print step between the transparent resin film and the black frame of the print layer.

However, the icon sheets of Comparative Example 1 and Comparative Example 2 were printed on the upper surface of the portion on which the print layer of the hard coat film was formed with no print layer, and on the upper portion of the print layer of the urethane acrylic type photocurable resin composition To form a photo-curable resin layer, thereby forming a photo-curable resin layer, and adhering a pressure-sensitive adhesive film to the surface of the transparent resin film and the black frame of the print layer, The bubbles were generated.

In addition, the icon sheet of Comparative Example 3 in which only the pressure-sensitive adhesive film was adhered to the hard coat film having the print layer could not fill the printed steps of the portion where the print step between the transparent resin film and the black frame of the print layer existed, Respectively.

The icon sheet of Comparative Example 3 was then able to reduce the bubbles generated by the autoclave process (40 ° C × 0.5m MPa × 15 minutes) as a whole, but the bubbles of such a size as to be visually recognizable remained there was.

The present invention relates to an icon sheet in which distortion of printed steps is small, bubble remains, the load is hardly exaggerated, and the pressure-sensitive adhesive layer is difficult to peel off, and a touch panel using the same. The icon sheet of the present invention can be suitably used as an anti-scattering film used for protecting the touch panel or an icon sheet that is adhered to the ITO surface of the capacitive touch panel.

One… Icon sheet, 2 ... Transparent resin film, 3... Print layer, 4... Cured resin layer, 5 ... Pressure-sensitive adhesive layer, 6 ... Release film, 7... Hard coat layer

Claims (5)

A method of producing an icon sheet having a print layer and a pressure-sensitive adhesive layer on one side of a hard coat film,
Process (1): When using the hard-coat film which provided the hard-coat layer on one side or both sides of the base material, and forming a hard-coat layer on one side, a hard-coat layer is formed on both sides on the other side, A step of forming a printed layer made of a frame and / or an icon by printing, if any
Step (2): a step of preparing an adhesive film having a pressure-sensitive adhesive layer formed on the exfoliated surface of the exfoliated film,
Step (3): A photocurable resin composition having fluidity is applied to an upper portion of a portion of the hard coat film on which the print layer is formed, on which the print layer is not coated, and an upper portion of the print layer, ,
Step (4): a step of bonding an adhesive film having a pressure-sensitive adhesive layer formed on the exfoliated surface of the exfoliated release film prepared on the photocurable resin layer via the pressure-sensitive adhesive layer,
Step (5): a step of curing the photo-curable resin layer by irradiating light to the photo-curable resin layer
Of the icon sheet. A method of producing an icon sheet having a print layer and a pressure-sensitive adhesive layer on one side of a hard coat film,
Process (1): When using the hard-coat film which provided the hard-coat layer on one side or both sides of the base material, and forming a hard-coat layer on one side, a hard-coat layer is formed on both sides on the other side, If there is, the process of preparing the elongate roll body of the hard-coat film which provided the printing layer which consists of a frame and / or an icon by printing on either surface,
Step (2): a step of preparing a long roll of an adhesive film having a pressure-sensitive adhesive layer formed on the exfoliated surface of the exfoliated film,
Step (3): While the long roll of the hard coat film is unwound and unwound, the upper surface of the portion of the hard coat film on which the print layer is formed, on which the print layer is not coated, A step of laminating a photocurable resin layer by applying a photocurable resin composition having flowability,
Process (4): The process of pasting the said adhesive film which unwound while rewinding the elongate roll body of the said adhesive film on the said photocurable resin layer through the said adhesive layer,
Step (5): a step of curing the photo-curable resin layer by irradiating light to the photo-curable resin layer
Of the icon sheet. An icon sheet obtained by the method for producing an icon sheet of claim 1 or 2. The touch panel according to claim 3, wherein the icon sheet is bonded via the pressure-sensitive adhesive layer. An electronic device incorporating the touch panel of claim 4.

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