JP2016002764A - Laminate, use thereof, and production method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laminate excellent in surface hardness and such bending resistance that the laminate can endure even repeated bending, and to provide a protective film which has antifouling property and is used particularly for flexible displays.SOLUTION: The laminate has 0.2 mm or smaller thickness, is made transparent and has a layer constitution of a thermoplastic resin film (I)/a photocurable resin (A) layer/another photocurable resin (B) layer. The flexural modulus of each of a photocurable resin (A) for forming the photocurable resin (A) layer and another photocurable resin (B) for forming the photocurable resin (B) layer is 3-6 GPa. The overall thickness (At+Bt) of the thickness (At) of the photocurable resin (A) layer and that (Bt) of the photocurable resin (B) layer is 0.1 mm or smaller and a thickness ratio (At/Bt) of the thickness (At) of the photocurable resin (A) layer to that (Bt) of the photocurable resin (B) layer is 1 or larger.

Description

  The present invention relates to a transparent laminate formed by laminating two or more photocurable resin layers on a thermoplastic resin film, and more specifically, it has excellent surface hardness and flex resistance (bending durability), and is a flexible display. The present invention relates to a laminate useful as a protective film or a touch panel substrate.

On the outermost surface of a portable information terminal such as a smartphone or tablet, a protective film (hereinafter, “film” means “sheet”) for the purpose of preventing scratches, preventing scattering, protecting the internal display, and the like. ) Is installed. Such a protective film is called as a cover, a window, or a cover window.
Currently, a glass plate having a thickness of about 0.3 to 1 mm and a resin laminate having a thickness of about 0.01 to 0.3 mm are used for the protective film. Such protective films are often required to have antifouling properties, fingerprint wiping properties, finger / pen sliding properties, printability, and the like, and also have a function that can be replaced according to consumer preferences. Yes.

  In recent years, flexible personal digital assistants and TVs with curved screens have been sold, and many displays that can be folded and rolled have been proposed. Such a display also requires a protective film, but the glass plate is broken, so that the safety of consumers cannot be ensured. In particular, in the case of a flexible display, a glass plate having a thickness of 0.3 mm or more is difficult to bend, and even an extremely thin glass film having a thickness of 0.2 mm or less is difficult to use because it is cracked when bent repeatedly.

  On the other hand, since the hard coat layer also breaks in the resin laminate, the so-called bending resistance that cannot withstand repeated bending cannot be satisfied. The protective film made of resin has a surface hardness such as polymethyl methacrylate (PMMA), polycarbonate, polyethylene terephthalate (PET), etc., which is a base material. is there. As the hard coat layer is harder and thicker, the surface hardness is expected to improve, but conversely, the bending resistance is lowered, and when bent, it cannot follow the flexibility of the resin used as the base material, causing cracks and cracks. Will occur.

  The surface hardness is evaluated by pencil hardness or steel wool scratch resistance. For example, in the case of pencil hardness, the required surface hardness is 6H or more. The flex resistance is evaluated by a mandrel test. Although it varies depending on the application, it is said that a radius of curvature of 1 mm (outer diameter of 2 mm) or less is required in order to adopt flexible.

  Therefore, in order to satisfy these various properties, a large number of laminates have been proposed. For example, it has been disclosed that a hard coat film having a specific layer structure provides a resin laminate having excellent surface hardness ( For example, see Patent Documents 1 to 3.) Moreover, it is disclosed that a specific active energy ray cured film gives a resin laminate having excellent surface hardness and antifouling properties (see, for example, Patent Documents 4 to 11). In addition, it is disclosed that a photopolymerizable composition comprising a polyfunctional urethane (meth) acrylate having an alicyclic structure and a polyfunctional (meth) acrylate having an alicyclic structure gives a resin molded article having high pencil hardness. (For example, refer to Patent Document 12). Moreover, the method of obtaining a photocuring molded object continuously using transparent films, such as a polyethylene terephthalate (PET), for a support film is disclosed (for example, refer patent document 13).

JP-A-11-300873 JP 2008-107762 A JP 2012-91370 A Japanese Patent Laid-Open No. 5-287215 JP 2006-160802 A JP 2010-121013 A JP 2002-194084 A JP 2003-192751 A JP 2003-335984 A JP 2012-031260 A Japanese Patent Laid-Open No. 9-100111 JP 2006-193596 A JP 2002-012682 A

  However, in the techniques disclosed in Patent Documents 1 to 10, as can be seen from the examples, the pencil hardness is about 5H at the maximum and does not reach 6H. In addition, in the disclosed technology of Patent Document 11, there is a description of pencil hardness 8H, but this is only when it is applied to a glass plate, and when applied to a soft resin base material, it is estimated that the maximum is about 5H. The Furthermore, in the disclosed technique of Patent Document 12, a resin molded body (single plate) having a pencil hardness of 7H is obtained. However, since it is composed of only a crosslinkable polymer, it is brittle and is resistant to repeated bending. In terms of sex, it is insufficient. In addition, in the disclosed technique of Patent Document 13, a resin molded body is obtained using an optical PET film as an upper and lower support during photocuring, but the expensive optical PET film on both sides will be discarded after production. It is hard to say that productivity is excellent. Moreover, it cannot be said that any of the disclosed technologies satisfy all the performances required for flexible displays, such as flex resistance, and further improvements are required.

  In view of this, the present invention provides a laminate having excellent surface resistance and bending resistance that can withstand repeated bending, and a protective film having antifouling properties, particularly a protective film for flexible displays. It is intended to do.

  However, as a result of intensive studies by the present inventors to solve the above-described problems, the present inventors have a layer structure of thermoplastic resin film [I] / photo-curing resin (A) layer / photo-curing resin (B) layer. The present invention has found that by providing two layers of a photo-curing resin layer having a specific bending elastic modulus and a specific thickness on a flexible thermoplastic resin film, high surface hardness and bending resistance can be expressed. completed.

  That is, the gist of the present invention is a transparent laminate having a thickness of 0.2 mm or less, and has a layer structure of thermoplastic resin film [I] / photo-curing resin (A) layer / photo-curing resin (B) layer. The flexural modulus of the photo-curing resin (A) forming the photo-curing resin (A) layer and the photo-curing resin (B) forming the photo-curing resin (B) layer is 3 to 6 GPa, respectively, and The total (At + Bt) of the thickness (At) of the photocurable resin (A) layer and the thickness (Bt) of the photocurable resin (B) layer is 0.1 mm or less, and the thickness of the photocurable resin (A) layer The present invention relates to a laminate having a thickness ratio (At / Bt) of (At) to the thickness (Bt) of the photo-curing resin (B) layer of 1 or more.

  Furthermore, in the present invention, a protective film for a display, a touch panel substrate, and a touch panel using the laminate are also provided, and further, the manufacture of the laminate is also provided.

  According to the present invention, it is possible to obtain a laminate having a surface hardness comparable to that of glass and having excellent bending resistance. Such a laminate is suitable as a protective film for a flexible display or a touch panel substrate.

Hereinafter, the present invention will be described in detail.
In the present invention, “(meth) acrylate” is a generic term for acrylate and methacrylate, and “(meth) acryl” is a generic term for acrylic and methacrylic. Moreover, polyfunctional here means having two or more (meth) acryloyl groups in a molecule | numerator.

  Bending resistance does not mean that the laminate does not bend or bend, but does not crack in the laminate even if it is bent, the laminate does not crack, and has bending durability. It means that.

  The laminate of the present invention is a transparent laminate having a thickness of 0.2 mm or less. The thickness of the laminate is preferably 0.17 mm or less, more preferably 0.15 mm or less. When the thickness exceeds 0.2 mm, the flexibility is lowered and the bending resistance tends to be lowered. In addition, as a lower limit of thickness, it is 0.01 mm, Preferably it is 0.05 mm.

  In the present invention, the transparency of the laminate is usually 80% or more, more preferably 85% or more, still more preferably 87% or more, and particularly preferably 90% or more. If the light transmittance is too low, it tends to be difficult to increase the brightness of the display.

  The laminate of the present invention has a layer structure of thermoplastic film [I] / photo-curing resin (A) layer / photo-curing resin (B) layer, and forms a photo-curing resin (A) layer ( The bending elastic modulus of the photocurable resin (B) forming the A) and photocurable resin (B) layers is 3 to 6 GPa, respectively. The bending elastic modulus of the photocurable resin (A) is more preferably 3 to 5 GPa, particularly preferably 3.5 to 4.5 GPa, and the bending elastic modulus of the photocurable resin (B) is more preferably 4 to 6 GPa. Particularly preferred is 4.5 to 5.5 GPa. If the flexural modulus of the photo-curing resin (A) and the photo-curing resin (B) is too low, the surface hardness tends to decrease, and if it is too large, the bending resistance tends to decrease.

In addition, about a bending elastic modulus, it measures as follows.
That is, in accordance with JIS K7171: 2008, the photocurable resin (A) was molded into a length of 20 mm × width of 5 mm × thickness of 1 mm, and an autograph “AG-5kNE” manufactured by Shimadzu Corporation (distance between fulcrums of 16 mm, 1 mm) / Min) to measure the flexural modulus (GPa) at 23 ° C. The same applies to the photocurable resin (B).

  Moreover, in this invention, it is important to have the following relationship regarding the thickness (At) of a photocurable resin (A) layer, and the thickness (Bt) of a photocurable resin (B) layer.

  That is, the total (At + Bt) of the thickness (At) of the photocurable resin (A) layer and the thickness (Bt) of the photocurable resin (B) layer is 0.1 mm or less, and the photocurable resin (A) layer It is important that the thickness ratio (At / Bt) of the thickness (At) and the thickness (Bt) of the photocurable resin (B) layer is 1 or more.

  The total thickness (At + Bt) is preferably 0.09 mm or less, more preferably 0.08 mm or less, and particularly preferably 0.07 mm or less. If the total thickness (At + Bt) is too thick, flexibility tends to decrease and flex resistance tends to decrease.

  Furthermore, the thickness ratio (At / Bt) of the thickness (At) of the photo-curing resin (A) layer and the thickness (Bt) of the photo-curing resin (B) layer is 1.5 or more, further 2 or more, In particular, it is preferably 2.5 or more. If the thickness ratio (At / Bt) is too small, the pencil hardness tends to decrease.

  In the present invention, the thickness of the thermoplastic resin film [I] is preferably 0.15 mm or less, particularly 0.03 to 0.15 mm, more preferably 0.05 to 0.12 mm, especially 0. It is preferably 0.07 to 0.1 mm. If the thickness is too thin, handling tends to be difficult, and if the thickness is too thick, the bending resistance of the laminate tends to decrease.

  Further, the thickness (At) of the photo-curing resin (A) layer is preferably 0.01 to 0.09 mm, particularly 0.03 to 0.07 mm, and more preferably 0.04 to 0.06 mm. Preferably there is. If the thickness is too thin, the surface hardness tends to decrease, and if it is too thick, the bending resistance tends to decrease.

  Furthermore, the thickness (Bt) of the photocurable resin (B) layer is preferably 0.005 to 0.05 mm, particularly 0.01 to 0.04 mm, more preferably 0.015 to 0.03 mm. Preferably there is. If the thickness is too thin, the surface hardness tends to decrease, and if it is too thick, the bending resistance tends to decrease.

  The thermoplastic resin film [I] used in the present invention may be any film having transparency, for example, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polycarbonate (PC), polymethyl methacrylate (PMMA). ), Polystyrene (PS), polyimide (PI), cycloolefin polymer (COP), cycloolefin copolymer (COC), and a film made of a thermoplastic resin such as triacetylcellulose (TAC). Among these, an inexpensive PET film and a polyimide film excellent in heat resistance are preferable.

Examples of the photocuring resin (A) layer in the present invention include (meth) acrylic resins, epoxy resins, thiol / ene addition resins, and (meth) acrylic resins are preferable from the viewpoint of rapid curing. From the viewpoint of adhesion, the photocurable composition (a) containing the following components (a1), (a2) and (a3) is preferably cured.
(A1) polyfunctional urethane (meth) acrylate compound (a2) alicyclic structure-containing polyfunctional (meth) acrylate compound (a3) photopolymerization initiator

The polyfunctional urethane (meth) acrylate compound (a1) is obtained by reacting a polyisocyanate compound and a hydroxyl group-containing (meth) acrylate compound.
Examples of the polyisocyanate compound include aromatic, aliphatic, and alicyclic polyisocyanates. Among them, tolylene diisocyanate, diphenylmethane diisocyanate, hydrogenated diphenylmethane diisocyanate, polyphenylmethane polyisocyanate, modified Diphenylmethane diisocyanate, hydrogenated xylylene diisocyanate, xylylene diisocyanate, hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, tetramethylxylylene diisocyanate, isophorone diisocyanate, norbornene diisocyanate, 1,3-bis (isocyanatomethyl) cyclohexane, phenylene diisocyanate, Lysine diisocyanate, lysine triisocyanate, naphthalene diiso Polyisocyanates such as ananates, trimer compounds or multimeric compounds of these polyisocyanates, burette type polyisocyanates, water-dispersed polyisocyanates (for example, “Aquanate 100”, “Aquanate” manufactured by Nippon Polyurethane Industry Co., Ltd.) 110 "," Aquanate 200 "," Aquanate 210 ", etc.), or the reaction products of these polyisocyanates and polyols. These can be used alone or in combination of two or more. Among these, alicyclic polyisocyanates such as hydrogenated diphenylmethane diisocyanate, isophorone diisocyanate, norbornene diisocyanate, and 1,3-bis (isocyanatomethyl) cyclohexane are preferable in that the water absorption of the resin laminate can be reduced.

  Examples of the hydroxyl group-containing (meth) acrylate compound include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 2 -Hydroxyethylacryloyl phosphate, 2- (meth) acryloyloxyethyl-2-hydroxypropyl phthalate, 2-hydroxy-3- (meth) acryloyloxypropyl (meth) acrylate, caprolactone-modified 2-hydroxyethyl (meth) acrylate , Pentaerythritol tri (meth) acrylate, dipentaerythritol penta (meth) acrylate, caprolactone-modified dipentaerythritol penta (meth) acrylate, caprolactone-modified pentae Suritorutori (meth) acrylate, ethylene oxide-modified dipentaerythritol penta (meth) acrylate, ethylene oxide modified pentaerythritol tri (meth) acrylate. These can be used alone or in combination of two or more. Among these, acrylate is preferable from the viewpoint of rapid curing, and carbon chains (carbon chain between hydroxyl group and (meth) acryloyl) such as 2-hydroxyethyl (meth) acrylate and pentaerythritol tri (meth) acrylate are relatively short. A thing is more preferable at the point which can improve the pencil hardness of a laminated body. From the viewpoint of the hardness of the photo-curing resin, polyfunctional (meth) acrylates, particularly trifunctional or higher (meth) acrylates are preferred.

Examples of the alicyclic structure-containing polyfunctional (meth) acrylate compound (a2) include bis (hydroxy) tricyclo [5.2.1.0 ^2,6 ] decane = di (meth) acrylate, bis (hydroxy). Tricyclo [5.2.1.0 ^2,6 ] decane = acrylate methacrylate, bis (hydroxymethyl) tricyclo [5.2.1.0 ^2,6 ] decane = di (meth) acrylate, bis (hydroxymethyl) tricyclo [5.2.1.0 ^2,6 ] decane = acrylate methacrylate, bis (hydroxy) pentacyclo [6.5.1.1 ^3,6 . 0 ^2,7 . 0 ^9,13 ] pentadecane = di (meth) acrylate, bis (hydroxy) pentacyclo [6.5.1.1 ^3,6 . 0 ^2,7 . 0 ^9,13 ] pentadecane = acrylate methacrylate, bis (hydroxymethyl) pentacyclo [6.5.1.1 ^3,6 . 0 ^2,7 . 0 ^9,13 ] pentadecane = di (meth) acrylate, bis (hydroxymethyl) pentacyclo [6.5.1.1 ^3,6 . 0 ^2,7 . 0 ^9,13 ] pentadecane = acrylate methacrylate, 2,2-bis [4- (β- (meth) acryloyloxyethoxy) cyclohexyl] propane, 1,3-bis ((meth) acryloyloxymethyl) cyclohexane, 1,3 -Bifunctional (meth) acrylates such as bis ((meth) acryloyloxyethyl) cyclohexane, 1,4-bis ((meth) acryloyloxymethyl) cyclohexane, 1,4-bis ((meth) acryloyloxyethyl) cyclohexane; Tris (hydroxy) tricyclo [5.2.1.0 ^2,6 ] decane = tri (meth) acrylate, tris (hydroxymethyl) tricyclo [5.2.1.0 ^2,6 ] decane = tri (meth) acrylate , Tris (hydroxy) pentacyclo [6.5.1.1 ^3,6 . 0 ^2,7 . 0 ^9,13 ] pentadecane = tri (meth) acrylate, tris (hydroxymethyl) pentacyclo [6.5.1.1 ^3,6 . 0 ^2,7 . 0 ^9,13 ] trifunctional such as pentadecane = tri (meth) acrylate, 1,3,5-tris ((meth) acryloyloxymethyl) cyclohexane, 1,3,5-tris ((meth) acryloyloxyethyl) cyclohexane The above (meth) acrylate is mentioned. Among these, from the viewpoint of the heat resistance of the substrate, bis (hydroxy) tricyclo [5.2.1.0 ^2,6 ] decane = di (meth) acrylate, bis (hydroxymethyl) tricyclo [5.2.1. 0 ^2,6 ] decane = di (meth) acrylate is preferred. Two or more of the alicyclic structure-containing polyfunctional (meth) acrylate compounds (a2) can be used in combination, or acrylate and methacrylate can be used in combination.

  As the photopolymerization initiator (a3), known compounds can be used. For example, benzophenone, benzoin methyl ether, benzoin propyl ether, diethoxyacetophenone, 1-hydroxycyclohexyl phenyl ketone, 2,6-dimethylbenzoyldiphenyl. Examples include phosphine oxide, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, 1,2-octanedione, 1- [4- (phenylthio) phenyl]-, 2- (O-benzoyloxime). Among these, radical-cleavage photopolymerization initiators such as 1-hydroxycyclohexyl phenyl ketone and 2,4,6-trimethylbenzoyldiphenylphosphine oxide are preferable. These photopolymerization initiators may be used alone or in combination of two or more.

  In the photocurable composition (a), the content ratio (weight ratio) of the polyfunctional urethane (meth) acrylate compound (a1) and the alicyclic structure-containing polyfunctional (meth) acrylate compound (a2) is (a1) / (A2) = 20/80 to 50/50 is preferable from the viewpoint of bending resistance, particularly 25/75 to 45/65, and further preferably 30/70 to 40/60. In such a content ratio, if the amount of (a1) is too small, the adhesiveness with the thermoplastic resin film [I] tends to decrease, and if it is too large, the laminate tends to warp.

  Moreover, content of a photoinitiator (a3) is with respect to a total of 100 weight part of a polyfunctional urethane (meth) acrylate type compound (a1) and an alicyclic structure containing polyfunctional (meth) acrylate type compound (a2). 0.1 to 10 parts by weight, more preferably 1 to 7 parts by weight, and particularly preferably 3 to 5 parts by weight. When the content is too small, photocuring tends not to proceed sufficiently, and when the content is too large, yellowing tends to occur in the laminate.

In the present invention, examples of the photo-curing resin (B) layer include (meth) acrylic resins, epoxy resins, thiol / ene addition resins, and (meth) acrylic resins are preferred from the viewpoint of rapid curing. From the viewpoint of adhesion, the photocurable composition (b) comprising the following components (b1), (b2) and (b3) is preferably cured.
(B1) polyfunctional urethane (meth) acrylate compound (b2) alicyclic structure-containing polyfunctional (meth) acrylate compound (b3) photopolymerization initiator

  About the said polyfunctional urethane (meth) acrylate type compound (b1), an alicyclic structure containing polyfunctional (meth) acrylate type compound (b2), and a photoinitiator (b3), the above-mentioned polyfunctional urethane (meth) acrylate type Examples are the same as those described for the compound (a1), the alicyclic structure-containing polyfunctional (meth) acrylate compound (a2), and the photopolymerization initiator (a3).

  In the photocurable composition (b), the content ratio (weight ratio) of the polyfunctional urethane (meth) acrylate compound (b1) and the alicyclic structure-containing polyfunctional (meth) acrylate compound (b2) is (a1) / (A2) = 51/49 to 80/20 is preferable in terms of pencil hardness, particularly 55/45 to 65/35, and more preferably 60/40 to 70/30. In such a content ratio, if the amount of (b1) is too small, the adhesiveness with the photocurable resin (A) layer tends to decrease, and if it is too large, the laminate tends to warp.

  Moreover, content of a photoinitiator (b3) is with respect to a total of 100 weight part of a polyfunctional urethane (meth) acrylate type compound (b1) and an alicyclic structure containing polyfunctional (meth) acrylate type compound (b2). 0.1 to 10 parts by weight, more preferably 1 to 7 parts by weight, and particularly preferably 3 to 5 parts by weight. When the content is too small, photocuring tends not to proceed sufficiently, and when the content is too large, yellowing tends to occur in the laminate.

In the present invention, it is also preferable from the viewpoint of antifouling property that the photocurable composition (b) contains a fluorine compound (b4) in addition to the above (b1) to (b3).
The fluorine compound (b4) is preferably a reactive fluorine compound in terms of maintaining antifouling properties for a long period of time, and the reactive fluorine compound is preferably an ultraviolet reactive fluorine compound in terms of pencil hardness, For example, the compound which has both a fluorinated alkyl group and an acryloyl group is mentioned. Among these, “Megafac RS-75” (manufactured by DIC) is preferable in terms of the contact angle.

  Content of a fluorine compound (b4) is 0.1 with respect to a total of 100 weight part of polyfunctional urethane (meth) acrylate type compound (b1) and alicyclic structure containing polyfunctional (meth) acrylate type compound (b2). It is preferably 10 to 10 parts by weight, more preferably 0.3 to 5 parts by weight, and particularly preferably 0.5 to 3 parts by weight. When the content is too small, the antifouling property tends to decrease, and when the content is too large, the adhesiveness of the photocurable resin (B) layer tends to decrease.

  In the present invention, the photocurable resin (B) layer contains a polysiloxane structure-containing polyfunctional urethane (meth) acrylate compound (b1 ′) and a photopolymerization initiator (b3). It is preferable in terms of surface hardness that the product (b ′) is cured. Furthermore, in addition to the polysiloxane structure-containing polyfunctional urethane (meth) acrylate-based compound (b1 ') and the photopolymerization initiator (b3), it is also preferable from the viewpoint of antifouling properties to contain a fluorine compound (b4).

  As the polysiloxane structure-containing polyfunctional urethane (meth) acrylate-based compound (b1 ′), known compounds can be appropriately selected, and examples thereof include the compounds described in Patent Documents 5 to 8 above.

  Polysiloxane structure-containing polyfunctional urethane (meth) acrylate compound (b1 ′), photopolymerization initiator (b3), fluorine compound (b4) content, polysiloxane structure-containing polyfunctional urethane (meth) acrylate compound (B1 ′) The photopolymerization initiator (b3) is preferably 0.1 to 10 parts by weight, more preferably 1 to 7 parts by weight, especially 3 to 5 parts by weight, based on 100 parts by weight of the fluorine compound. (B4) is preferably 0.1 to 10 parts by weight, more preferably 0.3 to 5 parts by weight, and particularly preferably 0.5 to 3 parts by weight.

  If the amount of the photopolymerization initiator (b3) is too small, the photocuring tends not to proceed sufficiently. If the amount is too large, the laminate tends to be yellowed. Moreover, when there are too few fluorine compounds (b4), there exists a tendency for antifouling property to fall, and when too much, there exists a tendency for the adhesiveness of a photocurable resin (B) layer to fall.

  In this invention, as above-mentioned, a polyfunctional urethane (meth) acrylate type compound and an alicyclic structure containing polyfunctional (meth) acrylate type compound are used as a photocurable resin (A) layer and (B) layer. However, the following functions are expressed by using these.

  That is, since the polyfunctional urethane (meth) acrylate compound is polyfunctional, it can form a cross-linked resin by curing to obtain a photocured resin layer with high surface hardness, and further has a urethane bond in the molecule. And since the obtained photocurable resin layer has moderate toughness by a hydrogen bond, the laminated body excellent in bending resistance can be obtained. In addition, since the alicyclic structure-containing polyfunctional (meth) acrylate compound is polyfunctional, it can form a crosslinked resin by curing to obtain a laminate with high surface hardness and heat resistance. Therefore, the water absorption rate of the laminate can be reduced.

  In the present invention, the bending elastic moduli of the photocurable resin (A) forming the photocurable resin (A) layer and the photocurable resin (B) forming the photocurable resin (B) layer are as described above. However, for these flexural moduli, the type and content ratio of the polyfunctional urethane (meth) acrylate-based compound and the alicyclic structure-containing polyfunctional (meth) acrylate-based compound, the type and content ratio of the fluorine compound, and the like are appropriately selected. For example, it can be increased by using a trifunctional or higher functional compound as the polyfunctional urethane (meth) acrylate compound.

  The photocurable compositions (a), (b), and (b ′) used in the present invention may contain a small amount of auxiliary components to such an extent that the surface hardness and flex resistance of the laminate are not impaired. Well, for example, monomers having an ethylenically unsaturated bond other than components (a1), (a2), (b1), (b2), and (b1 ′), chain transfer agents, antioxidants, ultraviolet absorbers , Thermal polymerization initiators, surfactants, antistatic agents, polymerization inhibitors, antifoaming agents, leveling agents, bluing agents, dyes and pigments, and the like.

  Examples of the monomer having an ethylenically unsaturated bond other than components (a1), (a2), (b1), (b2), and (b1 ′) include methyl methacrylate and 2-hydroxyethyl (meth) acrylate. , Phenyl (meth) acrylate, benzyl (meth) acrylate, monofunctional (meth) acrylate such as cyclohexyl (meth) acrylate, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate , Polyethylene glycol di (meth) acrylate, tetraethylene glycol or higher, 1,3-butylene glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, 2 Polyfunctional (meth) acrylates such as hydroxy 1,3-di (meth) acryloxypropane, 2,2-bis [4- (meth) acryloyloxyphenyl] propane, trimethylolpropane tri (meth) acrylate, acrylamide, methacryl Examples thereof include (meth) acrylic acid derivatives such as amide, acrylonitrile and methacrylonitrile, and styrene compounds such as styrene, chlorostyrene, divinylbenzene and α-methylstyrene.

  The content of the monomer having an ethylenically unsaturated bond other than the components (a1), (a2), (b1), (b2), and (b1 ′) is the polyfunctional urethane in the photocurable composition ( It is preferably 30 parts by weight or less, more preferably 20 parts by weight or less, and particularly preferably 10 parts by weight or less with respect to a total of 100 parts by weight of the (meth) acrylate compound and the alicyclic structure-containing polyfunctional (meth) acrylate compound. . If the content is too large, the surface hardness and flex resistance of the laminate tend to decrease.

  As the chain transfer agent, a polyfunctional mercaptan compound is preferable. Examples of the polyfunctional mercaptan compound include pentaerythritol tetrakisthioglycolate, pentaerythritol tetrakisthiopropionate, and the like. These polyfunctional mercaptan-based compounds are usually 10 weights with respect to a total of 100 parts by weight of the polyfunctional urethane (meth) acrylate compounds and alicyclic structure-containing polyfunctional (meth) acrylate compounds in the photocurable composition. It is preferably used at a ratio of not more than 5 parts, more preferably not more than 5 parts by weight, particularly preferably not more than 3 parts by weight. When there is too much this usage-amount, there exists a tendency for the surface hardness of the laminated body obtained to fall.

  Examples of the antioxidant include 2,6-di-t-butylphenol, 2,6-di-t-butyl-p-cresol, 2,4,6-tri-t-butylphenol, 2,6-di- t-butyl-4-s-butylphenol, 2,6-di-t-butyl-4-hydroxymethylphenol, n-octadecyl-β- (4′-hydroxy-3 ′, 5′-di-t-butylphenyl) ) Propionate, 2,6-di-tert-butyl-4- (N, N-dimethylaminomethyl) phenol, 3,5-di-tert-butyl-4-hydroxybenzylphosphonate-diethyl ester, 2,4 -Bis (n-octylthio) -6- (4-hydroxy-3 ', 5'-di-t-butylanilino) -1,3,5-triazine, 4,4-methylene-bis (2,6-di-) t-Butyl Enol), 1,6-hexanediol bis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], bis (3,5-di-tert-butyl-4-hydroxybenzyl) sulfide 4,4′-di-thiobis (2,6-di-t-butylphenol), 4,4′-tri-thiobis (2,6-di-t-butylphenol), 2,2-thiodiethylenebis [3 -(3,5-di-tert-butyl-4-hydroxyphenyl) propionate], N, N'-hexamethylenebis- (3,5-di-tert-butyl-4-hydroxyhydroxyhydrocinnamide, N, N′-bis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionyl] hydrazine, calcium (3,5-di-tert-butyl-4-hydroxybenzyl) monoethylphospho Phonate, 1,3,5-trimethyl-2,4,6-tris (3,5-di-t-butyl-4-hydroxybenzyl) benzene, tris (3,5-di-t-butyl-4-hydroxyphenyl) ) Isocyanurate, tris (3,5-di-t-butyl-4-hydroxybenzyl) isocyanurate, 1,3,5-tris-2 [3 (3,5-di-t-butyl-4-hydroxyphenyl) Propionyloxy] ethyl isocyanate, tetrakis [methylene-3- (3 ', 5'-di-t-butyl-4-hydroxyphenyl) propionate] methane, 3,5-di-t-butyl-4-hydroxybenzyl phosphite -A compound such as diethyl ester may be used, and these compounds may be used alone or in combination of two or more thereof. Styrene-3- (3 ', 5'-di -t- butyl-4-hydroxyphenyl) propionate] methane, particularly from the viewpoint of the effect of suppressing the hue increases.

  The content of the antioxidant is usually 0.001 with respect to a total of 100 parts by weight of the polyfunctional urethane (meth) acrylate compound and the alicyclic structure-containing polyfunctional (meth) acrylate compound in the photocurable composition. It is preferably ˜1 part by weight, particularly preferably 0.01 to 0.5 part by weight. When the amount of such an antioxidant is too small, the heat resistance of the laminate tends to decrease, and when the amount is too large, the light transmittance tends to decrease.

  The ultraviolet absorber is not particularly limited as long as it is soluble in the (meth) acrylate compound, and various ultraviolet absorbers can be used. Specific examples include salicylic acid ester, benzophenone, triazole, hydroxybenzoate, and cyanoacrylate. These ultraviolet absorbers may be used in combination. Among these, in terms of compatibility with (meth) acrylate compounds, benzophenone or triazole, specifically, (2-hydroxy-4-octyloxy-phenyl) -phenyl-methanone, 2-benzotriazole- Ultraviolet absorbers such as 2-yl-4-tert-octyl-phenol are preferred.

  The content of the ultraviolet absorber is usually 0.001 with respect to a total of 100 parts by weight of the polyfunctional urethane (meth) acrylate compound and the alicyclic structure-containing polyfunctional (meth) acrylate compound in the photocurable composition. It is preferably ˜1 part by weight, particularly preferably 0.01 to 0.1 part by weight. If the amount of the ultraviolet absorber is too small, the light resistance tends to be lowered. If the amount is too large, it takes time to cure the photocurable composition, or sufficient curing cannot be achieved.

  As the thermal polymerization initiator, known compounds can be used, such as hydroperoxide, t-butyl hydroperoxide, diisopropylbenzene hydroperoxide, 1,1,3,3-tetramethylbutyl hydroperoxide, and the like. Hydroperoxides, dialkyl peroxides such as di-t-butyl peroxide and dicumyl peroxide, peroxyesters such as t-butylperoxybenzoate, t-butylperoxy (2-ethylhexanoate), benzoylper Examples thereof include peroxides such as diacyl peroxides such as oxides, peroxycarbonates such as diisopropyl peroxycarbonate, peroxyketals, and ketone peroxides.

  Thus, a laminate having the layer structure of the thermoplastic resin film [I] / photo-curable resin (A) layer / photo-curable resin (B) layer of the present invention is obtained, and the photo-curable resin (B) layer in the laminate is obtained. The pencil hardness is preferably 6H or more. More preferably, it is 7H or more, Most preferably, it is 8H or more. If the pencil hardness is too low, the protective property of the protective film tends to be reduced. The upper limit of pencil hardness is 10H. In adjusting the pencil hardness to the above range, a method of appropriately controlling the type of the photocurable composition (b) or (b ′) described above, the content of the component, and the type and content ratio of the fluorine compound can be used. . For example, it is possible to use a polyfunctional urethane (meth) acrylate compound having 3 to 6 functional groups.

  Moreover, in this invention, it is preferable that the contact angle with the water of a photocurable resin (B) layer is 50 degrees or more. In particular, it is preferably 80 ° or more, more preferably 90 ° or more, and particularly preferably 100 ° or more, and the upper limit is preferably 130 ° or less, particularly 120 ° or less, and more preferably 110 ° or less. If the contact angle is too low, the antifouling property tends to decrease.

  In adjusting the contact angle to the above range, a method of appropriately controlling the type of the photocurable composition (b) or (b ′) described above, the content of the component, and the type and content ratio of the fluorine compound can be used. . In addition, when a contact angle is too large, it exists in the tendency for the adhesiveness of a photocurable resin (A) layer and a photocurable resin (B) layer to fall.

Next, the manufacturing method of the laminated body of this invention is explained in full detail.
In the laminate of the present invention, a photocurable composition (a) is applied on a thermoplastic resin film [I] such as a PET film, and photocured to form a photocurable resin (A) layer, The photocurable resin (A) layer is coated with the photocurable composition (b) or (b ′) and photocured to form a photocurable resin (B) layer. Application and photocuring may be performed sequentially using a general wet coat technique, and photocuring of the photocuring resin (A) layer may be performed by a light-transmitting material such as a thermoplastic resin film [I] and a glass plate. However, it is preferably performed in the following steps (1) to (6) in terms of improving surface hardness and adhesion.

(1) Step of applying photocurable composition (a) to thermoplastic resin film [I] (2) Step of covering thermoplastic resin film [II] on photocurable composition (a) (3) Activity Step of irradiating energy ray to cure photocurable composition (a) (4) Step of peeling thermoplastic resin film [II] from photocurable resin (A) layer (5) Photocurable resin (A) layer Step of applying photocurable composition (b) or (b ′) on top (6) Step of irradiating active energy ray to cure photocurable composition (b) or (b ′)

  In the laminate of the present invention, in order for the photocurable resin (B) layer to exhibit high pencil hardness, the photocurable composition (a) is sufficiently cured and the pencil hardness of the photocurable resin (A) layer is also high. Need to increase. In general wet coating, polymerization inhibition by oxygen, insufficient curing due to lower coating temperature, insufficient curing due to residual solvent, etc. are likely to occur. However, by performing the above-mentioned step (2), sufficient A photo-cured resin (A) layer cured to a high temperature can be obtained.

  The thermoplastic resin film [II] used in the step (2) is not particularly limited as long as it has transparency, and can be the same as the thermoplastic resin film [I]. For example, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polycarbonate (PC), polymethyl methacrylate (PMMA), polystyrene (PS), polyimide (PI), cycloolefin polymer (COP), cycloolefin copolymer (COC), triacetyl cellulose Examples thereof include a film made of a thermoplastic resin such as (TAC). Among these, an inexpensive PET film is preferable.

Furthermore, in terms of improving the hardness of the photocurable resin (A) layer and / or the photocurable resin (B) layer, the following step (3 ′) is performed after the step (3) and / or the step (6). It is preferable to perform the following step (6 ′) after.
(3 ′) A step of improving the degree of curing by irradiating the photocurable resin (A) layer with infrared rays (6 ′) A step of improving the degree of curing by irradiating the photocurable resin (B) layer with infrared rays.

  As infrared rays, it is preferable to perform infrared rays having a wavelength of 4 μm or more using a far infrared heater or an infrared laser so that the surface of the photocurable resin (A) layer and / or (B) is 50 ° C. or more. The heating temperature is more preferably 100 ° C. or higher, further preferably 150 ° C. or higher, and particularly preferably 200 ° C. or higher. When heating temperature is too low, it exists in the tendency for the pencil hardness of a photocurable resin (A) layer and / or (B) to fall. In addition, the upper limit of heating temperature is 400 degreeC normally.

The heating time is preferably within 10 minutes in order to avoid deformation of the thermoplastic resin film [I]. The heating time is more preferably within 5 minutes, further preferably within 3 minutes, and particularly preferably within 1 minute. When the heating time is too long, the hue of the photocurable resin (A) layer and / or (B) tends to be lowered. In addition, the minimum of heating time is 1 second normally.
When irradiating infrared rays, hot air can be used in combination.

  In the step (4), the thermoplastic resin film [II] is peeled from the photocurable resin (A) layer to obtain a laminate of the thermoplastic resin film [I] / photocurable resin (A) layer. In order to improve the adhesion between the two, a surface-treated thermoplastic resin film [I] such as an easy-adhesion PET film may be used.

  Further, as the thermoplastic resin film [II], an easily peelable PET film or an ultrathin PET film may be used in order to improve the peelability, or a smooth surface with less surface roughness than the thermoplastic film [I]. It is also possible to use a simple film.

In this invention, it is preferable to perform a process (3 '') after a process (3 ') at the point which improves the adhesiveness of a photocurable resin (A) layer / photocurable resin (B) layer.
(3 ″) Step of activating the surface of the photo-curing resin (A) layer by plasma treatment or corona treatment

  The method of plasma treatment or corona treatment is not particularly limited and can be performed using a commercially available treatment apparatus. However, plasma treatment is preferable from the viewpoint of the surface activation effect, and continuous treatment is possible. A pressure plasma treatment is more preferable.

  The method for applying the photocurable composition (a) or the photocurable composition (b) or (b ′) is not particularly limited, and is a die coat, spin coat, bar coat, spray coat, roll coat, or mask on one side. A known method such as dip coating or screen printing is used. Among these, die coating is preferable from the viewpoint of productivity.

The photocurable composition (a) and the photocurable composition (b) or (b ′) can be used by blending an organic solvent and adjusting the viscosity as necessary. Examples of the organic solvent include alcohols such as methanol, ethanol, propanol, n-butanol and i-butanol, ketones such as acetone, methyl isobutyl ketone, methyl ethyl ketone and cyclohexanone, cellosolves such as ethyl cellosolve, toluene, xylene Aromatic glycols such as propylene glycol monomethyl ether, acetates such as ethyl acetate and butyl acetate, and diacetone alcohol. These organic solvents may be used alone or in combination of two or more.
In the case of diluting with an organic solvent, photocuring is performed after applying and drying.

As for the method of light irradiation, for example, photocuring is preferably performed from both sides or one side using an active energy ray, particularly ultraviolet rays having a wavelength of 200 to 400 nm, in an irradiation light amount range of 1 to 100 J / cm ² . A more preferable range of the irradiation light amount is ^{2 to} 50 J / cm ² , and further preferably 3 to 30 J / cm ² . When the amount of irradiation light is too small, the polymerization tends to be insufficient, and when too much, the warpage of the laminate tends to increase. The illuminance of ultraviolet rays is usually 10 to 5000 mW / cm ² , preferably 100 to 1000 mW / cm ² . If the illuminance is too small, it tends to be hard to cure sufficiently to the deep part of the photo-curing resin layer, and if the illuminance is too large, polymerization tends to run away and the retardation of the laminate tends to increase.

Examples of the ultraviolet light source include a metal halide lamp, a high pressure mercury lamp, an electrodeless mercury lamp, and an LED lamp. In order to prevent polymerization from running away due to infrared rays generated from a light source, it is also possible to use a filter that blocks infrared rays, a mirror that does not reflect infrared rays, or the like for the lamp.
In the light irradiation, it is preferable to divide the light into a plurality of times because a laminated body with less warpage can be obtained. Moreover, performing under nitrogen is preferable in terms of rapid curing.

  The laminate obtained in the present invention may be heat-treated for improving the degree of polymerization or releasing stress strain. Examples of the method include heating in an oven and infrared heating.

  Thus, the laminate of the present invention can be obtained. From the viewpoint of productivity, the laminate is preferably a roll having a width of 300 mm or more. More preferably, the width is 500 mm or more, and the length is preferably 100 m or more, and particularly preferably 1000 m or more. The upper limit of the width is usually 5 m, and the upper limit of the length is usually 10,000 m.

The laminate of the present invention is very useful as a protective film for a display, and can be formed as a protective film with an adhesive layer by forming an adhesive layer on one side of the laminate. The material of the pressure-sensitive adhesive layer is not particularly limited, and an acrylic or silicon-based pressure-sensitive adhesive is appropriately used.
In the laminate, the pressure-sensitive adhesive layer is preferably formed on the opposite surface of the thermoplastic resin film [I] on which the photocurable resin (A) layer and the photocurable resin (B) are laminated.

  Moreover, the laminated body of this invention makes a transparent conductive film in the reverse surface in which the photocurable resin (A) layer and photocurable resin (B) layer of thermoplastic film [I] were formed, and is set as a touchscreen board | substrate. Furthermore, a touch panel can be obtained using such a touch panel substrate.

  The material of the transparent electrode is not particularly limited, and examples thereof include inorganic conductive films such as ITO and IGZO, and organic conductive films such as PEDOT. The surface resistance value of the transparent conductive film is preferably 1000 Ω / □ or less, more preferably 10 to 500 Ω / □, and still more preferably 50 to 200 Ω / □. If the surface resistance is too high, the conductivity tends to decrease.

EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated further more concretely, this invention is not limited to a following example, unless the summary is exceeded.
In the examples, “parts” and “%” mean weight basis.
The evaluation was performed as follows.

(1) Flexural modulus (GPa)
In accordance with JIS K7171: 2008, a photocurable resin (A) is molded into a length of 20 mm, a width of 5 mm, and a thickness of 1 mm, and an autograph “AG-5kNE” manufactured by Shimadzu Corporation (distance between supporting points: 16 mm, 1 mm / min) ), The flexural modulus (GPa) at 23 ° C. was measured. It measured similarly about photocurable resin (B).

(2) Pencil Hardness According to JIS K 5600-5-4, the pencil hardness of the surface of the photocured resin (B) layer of the laminate was measured.

(3) Bending resistance (mandrel test)
A test piece of 100 mm × 50 mm was allowed to stand for 48 hours in an environment of 23 ° C. and 50%, and then tested for bending resistance by the JIS K5600-5-1: 1999 cylindrical mandrel method (mandrel diameter of 2 mm with a type 1 test apparatus). The test was performed under a bending time of 2 seconds and an environment of 23 ° C. and 50%, and the photocured resin layer was visually observed with a microscope and evaluated as follows.
○ ・ ・ ・ No change △ ・ ・ ・ Cracks and cracks are observed with a microscope × ・ ・ ・ White turbidity is observed with visual inspection

(4) Transparency (%)
The total light transmittance (%) was measured using a Nippon Denshoku haze meter “NDH-2000”.

(5) Adhesiveness According to JIS K 5400 (1990 edition), evaluation was performed by an initial tape method and after a high temperature and high humidity test of 65 ° C., 95% RH, 1000 hours.
○ ・ ・ ・ No peeling at any interface × ・ ・ ・ There is peeling at any interface

(6) Antifouling property (ink wiping property)
A line was drawn with blue magic ink on the surface of the light-curing resin (B) layer of the laminate, and after standing for 24 hours, the appearance after wiping with a waste cloth was visually observed and evaluated as follows.
○ ・ ・ ・ Can be wiped clean △ ・ ・ ・ While it can be wiped off

(Ink repellency)
A line was drawn with blue magic ink on the surface of the photo-curing resin (B) layer of the laminate, and the mark of the magic ink was visually observed and evaluated as follows.
○ ... Repels ink and the traces of the lines are dotted. △ ... Repels ink and the traces of the lines become thin.

Moreover, each component for preparing each photocurable composition is as follows.
[Polyfunctional urethane (meth) acrylate compound (a1) or (b1)]
-(A1-1) or (b1-1): Hexafunctional alicyclic structure-containing urethane acrylate In a flask equipped with a thermometer, stirrer, water-cooled condenser and nitrogen gas inlet, 192.0 g (0.86 mol) of isophorone diisocyanate ) And pentaerythritol triacrylate [a mixture of pentaerythritol triacrylate and pentaerythritol tetraacrylate (hydroxyl value 120 mg KOH / g)] 808.0 g (1.73 mol), 0.01 g of hydroquinone methyl ether as a polymerization inhibitor, As a reaction catalyst, 0.01 g of dibutyltin dilaurate was added and reacted at 60 ° C. for 8 hours. When the residual isocyanate group became 0.3% or less, the reaction was terminated to obtain a hexafunctional alicyclic structure-containing urethane acrylate.

[Polysiloxane structure-containing polyfunctional urethane (meth) acrylate compound (b1 ′)]
(B1′-1): Polysiloxane structure-containing polyfunctional urethane acrylate and methyl ethyl ketone described below (manufactured by Nippon Synthetic Chemical Industry Co., Ltd., “AF-100”: solid content concentration 50%)
(B1'-2) Mixture of polysiloxane structure-containing polyfunctional urethane acrylate and methyl isobutyl ketone solvent (Mitsubishi Chemical Corporation, "H0745": solid content concentration 40%)
(B1′-3) Mixture of polysiloxane structure-containing polyfunctional urethane acrylate, fluorine compound, and methyl isobutyl ketone solvent (Mitsubishi Chemical Corporation, “H0502”: solid concentration 40%)

[Aricyclic structure-containing polyfunctional (meth) acrylate compound (a2) or (b2)]
(A2-1) or (b2-1): bis (hydroxymethyl) tricyclo [5.2.1.0 ^2,6 ] decane = diacrylate (“A-DCP” manufactured by Shin-Nakamura Chemical Co., Ltd.)

[Photopolymerization initiator (a3) or (b3)]
(A3-1) or (b3-1): 1-hydroxycyclohexyl phenyl ketone (“Irgacure 184” manufactured by Ciba Specialty Chemicals)

[Fluorine compound (b4)]
(B4-1) Reactive fluorine compound: Megafax (“RS-75” manufactured by DIC (solid content concentration 40%, MEK93 / MIBK7 solvent))

<Example 1>
[Preparation of Photocurable Composition (a)]
Hexafunctional alicyclic structure-containing urethane acrylate (a1-1) 30 parts, bis (hydroxymethyl) tricyclo [5.2.1.0 ^2,6 ] decane = diacrylate (a2-1) 70 parts, 1-hydroxycyclohexyl After stirring 5 parts of phenyl ketone (a3-1) at 60 ° C. until uniform, it was filtered through a 100 μm filter to obtain a photocurable composition (a-1). The bending elastic modulus of the photocurable resin obtained by photocuring the photocurable composition (a-1) was 4 GPa.

[Preparation of Photocurable Composition (b)]
60 parts urethane acrylate (b1-1) containing hexafunctional alicyclic structure, 40 parts bis (hydroxymethyl) tricyclo [5.2.1.0 ^2,6 ] decane diacrylate (b2-1), 1-hydroxycyclohexyl After stirring 5 parts of phenylketone (b3-1), 1 part of MegaFac RS-75 (b4-1), and 100 parts of propylene glycol monomethyl ether acetate at 60 ° C., the mixture was filtered through a 100 μm filter. Thus, a photocurable composition (b-1) was obtained. The photocurable composition (b-1) was dried at 80 ° C. and then photocured. The resulting photocurable resin had a flexural modulus of 5 GPa.

[Production of Laminate [I]]
As the thermoplastic resin film [I], a biaxially stretched PET film (Made by Mitsubishi Plastics, “Diafoil T600E”) having a width of 200 mm, a length of 300 mm, and a thickness of 0.1 mm is prepared. The above photocurable composition (a-1) was applied to a thickness of 0.05 mm by bar coating. Next, as the thermoplastic resin film [II], a biaxially stretched PET film (manufactured by Mitsubishi Plastics, “Diafoil S100”) having a thickness of 0.025 mm is prepared, and the top of the photocurable composition (a-1). Then, photocuring was performed by irradiating ultraviolet rays with an illuminance of 100 mw / cm ² and a light amount of 1 J / cm ² from the upper part to form a photocurable resin (A) layer. After peeling off and removing the thermoplastic resin film [II], far-infrared heating is performed using a far-infrared heating device ("FR-24" manufactured by Futaba Kagaku) so that the surface of the photocurable resin (A) layer becomes 200 ° C. The plasma treatment was performed for 1 minute, and further using a normal pressure plasma surface treatment apparatus (“RD640” manufactured by Sekisui Chemical). The processing speed was 10 m / min. Finally, on the photocurable resin (A) layer, the photocurable composition (b-1) was applied to a thickness of 0.02 mm by bar coating, dried at 80 ° C. for 10 minutes, and then the irradiation conditions described above. Was photocured to form a photocured resin (B) layer. The far-infrared heating is performed for 1 minute so that the surface of the photocurable resin (B) layer is also 200 ° C., and the layer structure of the thermoplastic resin film [I] / photocurable resin (A) layer / photocurable resin (B) layer The laminated body which has was obtained.
About the obtained laminated body, when said evaluation was performed, it had favorable performance as Table 2 shows.

<Example 2>
In Example 1, it carried out similarly except apply | coating a photocurable composition (a-1) to thickness 0.03mm, and obtained the laminated body.
About the obtained laminated body, when said evaluation was performed, it had favorable performance as Table 2 shows.

<Example 3>
In Example 1, it carried out similarly except using a biaxially-stretched PET film of thickness 0.05mm as thermoplastic resin film [I], and obtained the laminated body.
About the obtained laminated body, when said evaluation was performed, it had favorable performance as Table 2 shows.

<Example 4>
In Example 1, it replaced with the photocurable composition (b-1) and carried out similarly except using the following photocurable composition (b'-1), and obtained the laminated body.
About the obtained laminated body, when said evaluation was performed, it had favorable performance as Table 2 shows.

[Preparation of Photocurable Composition (b′-1)]
Mixture of polysiloxane structure-containing polyfunctional urethane acrylate and methyl ethyl ketone (solid content concentration 50%) (b1′-1) 100 parts, 1-hydroxycyclohexyl phenyl ketone (b3-1) 2.5 parts, Megafax RS-75 ( b4-1) One part was stirred at 60 ° C. until uniform, and then filtered through a 100 μm filter to obtain a photocurable composition (b′-1). The photocurable composition (b′-1) was dried at 80 ° C. and then photocured. The resulting photocurable resin had a flexural modulus of 5 GPa.

<Example 5>
In Example 1, it replaced with the photocurable composition (b-1) and carried out similarly except using the following photocurable composition (b'-2), and obtained the laminated body.
About the obtained laminated body, when said evaluation was performed, it had favorable performance as Table 2 shows.

[Preparation of Photocurable Composition (b′-2)]
Mixing polysiloxane structure-containing polyfunctional urethane acrylate and methyl isobutyl ketone (solid content concentration 40%) (b1′-2) 100 parts, 1-hydroxycyclohexyl phenyl ketone (b3-1) 2.5 parts at 60 ° C. The mixture was stirred until uniform, and then filtered through a 100 μm filter to obtain a photocurable composition (b′-2). The photocurable composition (b′-2) was dried at 80 ° C. and then photocured. The resulting photocurable resin had a flexural modulus of 5 GPa.

<Example 6>
In Example 1, it replaced with the photocurable composition (b-1) and carried out similarly except using the following photocurable composition (b'-3), and obtained the laminated body.
About the obtained laminated body, when said evaluation was performed, it had favorable performance as Table 2 shows.

[Preparation of Photocurable Composition (b′-3)]
Polysiloxane structure-containing polyfunctional urethane acrylate compound, fluorine compound, methyl isobutyl ketone mixture (solid content concentration 40%) (b1′-3) 100 parts, 1-hydroxycyclohexyl phenyl ketone (b3-1) 2.5 parts Was stirred at 60 ° C. until uniform, and then filtered through a 100 μm filter to obtain a photocurable composition (b′-3). The photocurable composition (b′-3) was dried at 80 ° C. and then photocured. The resulting photocurable resin had a flexural modulus of 5 GPa.

<Example 7>
A laminate was obtained in the same manner as in Example 1 except that the photocuring resin (A) layer was formed without using the thermoplastic resin film [II].
About the obtained laminated body, when said evaluation was performed, it had favorable performance as Table 2 shows.

<Example 8>
In Example 1, as the thermoplastic resin films [I] and [II], the photocurable compositions (a-1) and (b-1) are die-coated using a PET roll film having a width of 500 mm and a length of 1000 m. Except for the above, the same procedure was followed to obtain a roll of laminate.
About the obtained laminated body, when said evaluation was performed, it had favorable performance as Table 2 shows.

[Preparation of protective film]
<Example 9>
Using the laminate obtained in Example 1, an acrylic pressure-sensitive adhesive (manufactured by Nippon Synthetic Chemical Industry Co., Ltd., on the surface of the thermoplastic resin film [I] (the surface on which the photocurable resin layer is not formed), “ "Coponyl 5740") and 100 parts of a crosslinking agent (trimethylolpropane adduct of tolylene diisocyanate; "Coronate L" manufactured by Nippon Polyurethane Co., Ltd.) were applied so that the thickness after drying was 0.1 mm. It dried and formed the adhesive layer.
The obtained laminate with an adhesive layer had good reworkability, and the laminate was useful as a protective film.

[Production of touch panel]
<Example 10>
Using the laminate obtained in Example 1, an ITO film having a thickness of 200 mm was formed at 180 ° C. on the surface of the thermoplastic resin film [I] (the surface on which the photocurable resin layer was not formed) by sputtering. Was formed into a transparent conductive film.
The obtained laminate with transparent conductive film (ITO film surface) had a surface resistance of 100Ω / □, and the laminate was useful as a touch panel substrate.

<Comparative Example 1>
In Example 1, it carried out similarly except apply | coating a photocurable composition (a-1) to thickness 0.1mm, and obtained the laminated body.
When the obtained laminate was evaluated as described above, it was inferior in flex resistance as shown in Table 2.

<Comparative Example 2>
In Example 1, it carried out similarly except apply | coating a photocurable composition (a-1) to thickness 0.01mm, and obtained the laminated body.
About the obtained laminated body, when said evaluation was performed, as Table 2 showed, it was inferior to pencil hardness.

<Comparative Example 3>
Two optical polishing glasses are made to face each other, a photocurable composition (a-1) is poured at 23 ° C. into a mold using a silicon plate having a thickness of 0.2 mm as a spacer, and a metal halide lamp is used. Ultraviolet rays were irradiated from both sides with a light amount of 20 J / cm ² and demolded to obtain a photo-curing resin sheet.
A laminate was obtained in the same manner as in Example 1 except that the obtained photocurable resin sheet was used instead of the thermoplastic resin film [I].
When the obtained laminate was evaluated, it was inferior in flex resistance as shown in Table 2.

<Comparative Example 4>
In Example 1, as a photocurable composition (a), a photocurable composition (a-2) comprising 100 parts of 1,6-hexanediol diacrylate and 5 parts of 1-hydroxycyclohexyl phenyl ketone (a3-1). ) Was used in the same manner to obtain a laminate.
The bending elastic modulus of the photocurable resin obtained by photocuring the photocurable composition (a-2) was 2 GPa.
About the obtained laminated body, when said evaluation was performed, as Table 2 showed, it was inferior to pencil hardness.

<Comparative Example 5>
In Example 1, as a photocurable composition (a), a photocurable composition comprising 100 parts of a hexafunctional alicyclic structure-containing urethane acrylate (a1-1) and 5 parts of 1-hydroxycyclohexyl phenyl ketone (a3-1). A laminate was obtained in the same manner except that the product (a-3) was used. The bending elastic modulus of the photocurable resin obtained by photocuring the photocurable composition (a-3) was 7 GPa.
When the obtained laminate was evaluated as described above, it was inferior in flex resistance as shown in Table 2.

<Comparative Example 6>
In Example 1, as a photocurable composition (a), a photocurable composition (a-2) comprising 100 parts of 1,6-hexanediol diacrylate and 5 parts of 1-hydroxycyclohexyl phenyl ketone (a3-1). ) And 100 parts of hexafunctional alicyclic structure-containing urethane acrylate (b1-1), 5 parts of 1-hydroxycyclohexyl phenyl ketone (b3-1), and propylene glycol monomethyl ether acetate as the photocurable composition (b) A laminate was obtained in the same manner except that 100 parts of the photocurable composition (b-2) was used. The photocuring resin obtained by photocuring the photocurable composition (a-2) has a flexural modulus of 2 GPa, and light obtained by photocuring the photocurable composition (b-2). The bending elastic modulus of the cured resin is 7 GPa.
As a result of the above evaluation, the obtained laminate was inferior in pencil hardness and flex resistance as shown in Table 2.

  From the above evaluation results, if the thickness of each layer of the laminate is not adjusted, both pencil hardness and flex resistance cannot be satisfied, and a protective film useful for flexible displays cannot be obtained. In the examples satisfying the above, both the pencil hardness and the bending resistance were excellent in a well-balanced manner.

  The laminate of the present invention can be advantageously used for various optical materials and electronic materials. For example, protective sheet, touch panel, liquid crystal substrate, organic / inorganic EL substrate, PDP substrate, electronic paper substrate, light guide plate, phase difference plate, optical filter, etc. It can be used for recording applications, energy applications such as thin film battery substrates and solar cell substrates, optical communication applications such as optical waveguides, and functional films / sheets and various optical films / sheets. In addition to optical materials and electronic materials, it can also be used in, for example, automotive materials, building materials, medical materials, stationery, and the like.

Claims (18)

  A transparent laminate having a thickness of 0.2 mm or less, having a layer structure of thermoplastic resin film [I] / photo-curing resin (A) layer / photo-curing resin (B) layer, and photo-curing resin (A ) The photocuring resin (A) forming the layer and the photocuring resin (B) forming the photocuring resin (B) layer each have a flexural modulus of 3 to 6 GPa, and the photocuring resin (A) layer The sum (At + Bt) of the thickness (At) and the thickness (Bt) of the photocurable resin (B) layer is 0.1 mm or less, and the thickness (At) of the photocurable resin (A) layer and the photocurable resin ( B) A laminate having a layer thickness (Bt) thickness ratio (At / Bt) of 1 or more. The photocurable resin (A) layer contains the following components (a1), (a2) and (a3), and the content ratio (weight ratio) of (a1) and (a2) is (a1) / (a2) The laminate according to claim 1, which is obtained by curing a photocurable composition (a) satisfying = 20/80 to 50/50.
(A1) polyfunctional urethane (meth) acrylate compound (a2) alicyclic structure-containing polyfunctional (meth) acrylate compound (a3) photopolymerization initiator The photocurable resin (B) layer contains the following components (b1), (b2) and (b3), and the content ratio (weight ratio) of (b1) and (b2) is (b1) / (b2) The laminate according to claim 1 or 2, wherein the photocurable composition (b) satisfying = 51/49 to 80/20 is cured.
(B1) polyfunctional urethane (meth) acrylate compound (b2) alicyclic structure-containing polyfunctional (meth) acrylate compound (b3) photopolymerization initiator   The laminate according to claim 3, wherein the photocurable composition (b) contains a fluorine compound (b4).   The photocurable resin (B) layer cures the photocurable composition (b ′) containing the polysiloxane structure-containing polyfunctional urethane (meth) acrylate compound (b1 ′) and the photopolymerization initiator (b3). The laminate according to claim 1, wherein the laminate is formed as described above.   The laminate according to claim 5, wherein the photocurable composition (b ') contains a fluorine compound (b4).   The laminate according to any one of claims 1 to 6, wherein the photocuring resin (B) layer has a pencil hardness of 6H or more.   The laminated body according to any one of claims 1 to 7, wherein a contact angle with water on the surface of the photocurable resin (B) layer is 90 ° or more.   The thermoplastic resin film [I] is a polyester film having a thickness of 0.15 mm or less, and the laminate according to any one of claims 1 to 8.   The laminate according to any one of claims 1 to 9, which is a roll body having a width of 300 mm or more and a length of 100 m or more.   It uses as a protective film of a display, The laminated body in any one of Claims 1-10 characterized by the above-mentioned.   The adhesive layer is formed in the reverse surface on which the photocurable resin (A) layer and the photocurable resin (B) were laminated | stacked of thermoplastic resin film [I], Any one of Claims 1-11 characterized by the above-mentioned. Or a laminate.   A protective film for a display comprising the laminate according to claim 1.   A transparent conductive film is formed on the opposite surface of the thermoplastic resin film [I] of the laminate according to claim 1 on which the photocurable resin (A) layer and the photocurable resin (B) layer are formed. A touch panel substrate, characterized in that   A touch panel comprising the touch panel substrate according to claim 14. It passes the following process (1)-(6), The manufacturing method of the laminated body in any one of Claims 1-12 characterized by the above-mentioned.
(1) Step of applying photocurable composition (a) to thermoplastic resin film [I] (2) Step of covering thermoplastic resin film [II] on photocurable composition (a) (3) Activity Step of irradiating energy ray to cure photocurable composition (a) (4) Step of peeling thermoplastic resin film [II] from photocurable resin (A) layer (5) Photocurable resin (A) layer Step of applying photocurable composition (b) or (b ′) on top (6) Step of irradiating active energy ray to cure photocurable composition (b) or (b ′) The method for producing a laminate according to claim 16, wherein the following step (3 ') is performed after the step (3) and / or the following step (6') is performed after the step (6).
(3 ′) A step of improving the degree of curing by irradiating the photocurable resin (A) layer with infrared rays (6 ′) A step of improving the degree of curing by irradiating the photocurable resin (B) layer with infrared rays. The manufacturing method of the laminated body of Claim 17 which performs the following process (3 '') after a process (3 ').
(3 ″) Step of activating the surface of the photo-curing resin (A) layer by plasma treatment or corona treatment