JP6031195B2 - Photocurable resin composition and cured film thereof - Google Patents

Description

  The present invention relates to a photocurable resin composition suitably used for forming a hard coat layer and a cured film thereof.

  Conventionally, information terminal devices such as a mobile phone, a personal digital assistant (PDA), a portable game machine, a digital camera, a personal computer, and a television are known. In recent years, in such information terminal devices, a touch panel is mounted on the front surface of the display panel. The touch panel can input necessary information such as data information to the information terminal device by pressing the surface panel with a finger or a pen.

  Examples of the touch panel classification include an optical method, an ultrasonic method, a capacitance method, and a resistive film method. In the capacitive touch panel, a laminated film having a transparent base material and a transparent conductive layer having a pattern shape such as a stripe shape disposed on the transparent base material is used.

  If the surface of the transparent substrate is scratched, the transparency is lowered. Therefore, a hard coat layer is formed by applying a coating agent on the surface of the transparent substrate, and a transparent conductive layer is disposed on the hard coat layer. When the adhesion between the hard coat layer and the transparent conductive layer is low, the transparent conductive layer is disposed on the hard coat layer via an adhesive layer. According to the hard coat layer, scratch resistance can be imparted to the surface of the transparent substrate. Such a hard coat layer is required to have high transparency in order to ensure the visibility of the touch panel.

  Conventionally, various investigations have been made on coating agents used for forming a hard coat layer. In Patent Document 1, (A) acrylic resin 3 to 40% by mass, (B) polyoxyethylene-polyoxypropylene block copolymer 0.1 to 5% by mass, and (C) two or more lights in one molecule The photocurable hydrophilic coating agent containing the resin component containing 55-95 mass% of photopolymerizable polyfunctional compounds which have a polymeric group is disclosed.

  In Patent Document 2, a reaction obtained by adding a carboxyl group-containing (meth) acrylic compound (a2) to a polymer obtained by polymerizing a polymerization component (a1) containing a vinyl compound having an epoxy group in the molecule. Active energy ray curing containing product (A), colloidal silica (B), phosphoric acid compound (C) containing 1 or 2 vinyl groups in the molecule, and polyfunctional (meth) acrylic compound (D) A mold resin composition is disclosed.

  Patent Document 3 discloses an optical sheet that has a functional layer on at least one surface of a transparent substrate, and the functional layer is made by dispersing translucent inorganic particles and / or translucent organic particles in a transparent resin. ing.

International Publication No. 2011/013497 Specification JP 2009-286972 A JP 2010-66549 A

  The hard coat layer formed using the photocurable hydrophilic coating agent of Patent Document 1 has low blocking resistance. Therefore, when the transparent base material which has a hard-coat layer is wound up in roll shape or stored, it will become difficult for the transparent base materials to adhere and peel.

  The active energy ray-curable resin composition of Patent Document 2 contains colloidal silica as inorganic particles. Concavities and convexities are formed by inorganic particles on the surface of the hard coat layer formed using the active energy ray-curable resin composition, thereby imparting blocking resistance to the hard coat layer. However, the use of only inorganic particles can not only sufficiently improve the blocking resistance of the hard coat layer, but also lowers the transparency of the hard coat layer.

  In the optical sheet of Patent Document 3, irregularities are formed on the surface of the functional layer by translucent inorganic particles and / or translucent organic particles. However, such irregularities are formed in order to impart antiglare properties to the optical sheet. For this purpose, translucent inorganic particles and translucent organic particles having a large particle diameter are used. Use of such translucent inorganic particles and translucent organic particles reduces the transparency of the functional layer.

  Moreover, formation of a transparent conductive layer or an adhesive layer on the hard coat layer can be performed, for example, by applying an ink such as a composition containing a conductive paste or an adhesive to the hard coat layer. However, since the hard coat layer has low compatibility with ink, when the ink is applied on the hard coat layer, the hard coat layer repels the ink. Therefore, ink cannot be printed with high accuracy, and a transparent conductive layer or adhesive layer having a desired pattern shape or uniform thickness cannot be formed on the hard coat layer. Therefore, it is also necessary to improve the printability of the hard coat layer.

  Therefore, an object of the present invention is to provide a photocurable resin composition capable of forming a hard coat layer that has improved blocking resistance without lowering transparency and also has excellent printability. Is to provide.

The photocurable resin composition of the present invention is
The hydroxyl value is 10 to 350 mg KOH / g, the (meth) acryl equivalent is 100 to 800 g / eq, the weight average molecular weight is 10,000 to 200,000, and the glass transition point is 50 to 110 ° C. (Meth) acrylic polymer (A) having a photopolymerizable group and a hydroxyl group in the side chain;
Inorganic particles (B) having an average particle diameter of 10 nm to 500 nm;
Organic particles (C) having an average particle diameter of 10 nm to 500 nm;
A photopolymerizable polyfunctional compound (D) having two or more photopolymerizable groups in one molecule;
And the total weight of the (meth) acrylic polymer (A), the inorganic particles (B), the organic particles (C), and the photopolymerizable polyfunctional compound (D),
The content of the (meth) acrylic polymer (A) is 10 to 40% by weight,
The content of the inorganic particles (B) is 5 to 40% by weight,
The content of the organic particles (C) is 0.5 to 10% by weight,
Content of the said photopolymerizable polyfunctional compound (D) is 20 to 70 weight%, It is characterized by the above-mentioned.

  The (meth) acrylic polymer (A) preferably contains 10 to 90% by weight of an alkyl (meth) acrylate component.

  The inorganic particles (B) are preferably at least one of metal particles and metal oxide particles.

  The organic particles (C) are preferably (meth) acrylic resin particles.

  The photocurable resin composition preferably contains a photopolymerization initiator.

  Moreover, the cured film of the present invention is obtained by curing the photocurable resin composition.

  According to the photocurable resin composition of the present invention, it is possible to form a hard coat layer that has improved blocking resistance without lowering transparency and also has excellent printability.

[Photocurable resin composition]
The photocurable resin composition of the present invention has a (meth) acrylic polymer (A), an inorganic particle (B), an organic particle (C), and one molecule having a photopolymerizable group and a hydroxyl group in the side chain. A photopolymerizable polyfunctional compound (D) having two or more photopolymerizable groups is contained therein.

((Meth) acrylic polymer (A))
The photocurable resin composition of the present invention contains at least one (meth) acrylic polymer (A) having a photopolymerizable group and a hydroxyl group in the side chain. By using the (meth) acrylic polymer (A), a hard coat layer having excellent transparency can be formed. The (meth) acrylic polymer (A) can be radically polymerized with a photopolymerizable polyfunctional compound (D) and a photopolymerizable group to form a crosslinked structure. Thereby, a hard coat layer having high hardness and excellent scratch resistance can be formed.

  The (meth) acrylic polymer (A) may have at least one photopolymerizable group and a hydroxyl group in the side chain, but the (meth) acrylic polymer (A) is photopolymerizable in the side chain. It is preferable that each group has two or more hydroxyl groups. In the present invention, (meth) acryl means acryl or methacryl.

  If the photopolymerizable group of the (meth) acrylic polymer (A) has an ethylenically unsaturated double bond capable of radical polymerization with the photopolymerizable group of the photopolymerizable polyfunctional compound (D) described later. Good. Examples of the photopolymerizable group include an acryloyl group, a methacryloyl group, a styryl group, a vinyl group, and an allyl group, and an acryloyl group and a methacryloyl group are preferable.

As the (meth) acrylic polymer (A), the following (meth) acrylic polymers (A1) to (A3) are preferably exemplified.
A polymer having a glycidyl group obtained by radical polymerization of a monomer composition (I) containing a radically polymerizable monomer having a glycidyl group and, if necessary, an alkyl (meth) acrylate having no glycidyl group. (Meth) acrylic polymer (A1) obtained by adding a compound having a carboxyl group and a photopolymerizable group to I ′);
Polymer (II ′) having a hydroxyl group obtained by radical polymerization of a radically polymerizable monomer having a hydroxyl group and, if necessary, a monomer composition (II) containing an alkyl (meth) acrylate not having a hydroxyl group (Meth) acrylic polymer (A2) obtained by adding a compound having an isocyanate group and a photopolymerizable group to the above, and a radical polymerizable monomer having a carboxyl group, and optionally having a carboxyl group By adding a compound having a glycidyl group and a photopolymerizable group to a polymer (III ′) having a carboxyl group obtained by radical polymerization of a monomer composition (III) containing no alkyl (meth) acrylate The resulting (meth) acrylic polymer (A3).

The (meth) acrylic polymers (A1) to (A3) can be produced, for example, by the following methods (1) to (3).
(1) Radical polymerization of a monomer composition (I) containing a radically polymerizable monomer having a glycidyl group and, if necessary, an alkyl (meth) acrylate having no glycidyl group in the presence of a radical polymerization initiator (Meth) acrylic polymer (A1) by adding a compound having a carboxyl group and a photopolymerizable group to the polymer (I ′) and obtaining a polymer (I ′) having a glycidyl group A method comprising the steps of:
(2) Radical polymerization of a radical polymerizable monomer having a hydroxyl group and, if necessary, a monomer composition (II) containing an alkyl (meth) acrylate having no hydroxyl group in the presence of a radical polymerization initiator. A step of obtaining a polymer (II ′) having a hydroxyl group by the step, and a step of obtaining a (meth) acrylic polymer (A2) by adding a compound having an isocyanate group and a photopolymerizable group to the polymer (II ′). And (3) a radically polymerizable monomer having a carboxyl group, and if necessary, a monomer composition (III) containing an alkyl (meth) acrylate having no carboxyl group, the presence of a radical polymerization initiator A step of obtaining a polymer (III ′) having a carboxyl group by radical polymerization under the following conditions; And (1) adding a compound having a glycidyl group and a photopolymerizable group to obtain a (meth) acrylic polymer (A3).

  A specific example of the production method (1) of the (meth) acrylic polymer (A1) will be described below. A radically polymerizable monomer having a glycidyl group and, if necessary, a monomer composition (I) containing an alkyl (meth) acrylate not having a glycidyl group in a reaction vessel in the presence of a radical polymerization initiator. By polymerizing, a polymer (I ′) having a glycidyl group is produced. Next, a compound having a carboxyl group and a photopolymerizable group and, if necessary, a catalyst are added to the reaction vessel. If necessary, a polymerization inhibitor such as p-methoxyphenol or hydroquinone (HQ) may be added to the reaction vessel. After that, while oxygen is blown into the reaction vessel as necessary, for example, the reaction solution is controlled to be 30 to 150 ° C., and is allowed to react for 6 to 12 hours, thereby photopolymerizing the side chain. A (meth) acrylic polymer (A1) having a functional group and a hydroxyl group can be produced.

  Examples of the radical polymerizable monomer having a glycidyl group include glycidyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate glycidyl ether, and allyl glycidyl ether, with glycidyl (meth) acrylate being preferred. In addition, the radically polymerizable monomer which has a glycidyl group may be used independently, or 2 or more types may be used together. In addition, (meth) acrylate means an acrylate or a methacrylate.

  The content of the radical polymerizable monomer having a glycidyl group in the monomer composition (I) is preferably 10 to 90% by weight, and more preferably 20 to 80% by weight. By setting the content of the radical polymerizable monomer having a glycidyl group to be equal to or higher than the above lower limit value, a hard coat layer having a high crosslinking density and excellent hardness can be formed. Moreover, gelatinization at the time of the synthesis | combination of a (meth) acrylic-type polymer can be suppressed by making content of the radically polymerizable monomer which has a glycidyl group below into the said upper limit.

  The monomer composition (I) preferably contains an alkyl (meth) acrylate having no glycidyl group. The alkyl (meth) acrylate having no glycidyl group preferably has no hydroxyl group. Such alkyl (meth) acrylates include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, pentyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) ) Acrylate, octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, nonyl (meth) acrylate, decyl (meth) acrylate, benzyl (meth) acrylate, dicyclopentadienyl (meth) acrylate, and the like. . Of these, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, and butyl (meth) acrylate are preferable, and methyl (meth) acrylate is more preferable. In addition, alkyl (meth) acrylate may be used independently or 2 or more types may be used together.

  10 to 90 weight% is preferable and, as for content of the alkyl (meth) acrylate which does not have a glycidyl group in monomer composition (I), 20 to 80 weight% is more preferable. By making content of the alkyl (meth) acrylate which does not have a glycidyl group more than the said lower limit, gelatinization at the time of the synthesis | combination of a (meth) acrylic-type polymer can be suppressed. Moreover, by setting the content of the alkyl (meth) acrylate having no glycidyl group to be the upper limit value or less, a hard coat layer having a high crosslink density and excellent hardness can be formed.

  The monomer composition (I) may contain an alkyl (meth) acrylate having a hydroxyl group. By using an alkyl (meth) acrylate having a hydroxyl group, the hydroxyl value of the (meth) acrylic polymer (A1) can be adjusted. Examples of the alkyl (meth) acrylate having a hydroxyl group include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 4 -Hydroxybutyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, 8-hydroxyoctyl (meth) acrylate, 10-hydroxydecyl (meth) acrylate, 12-hydroxylauryl (meth) acrylate and the like. Of these, 2-hydroxyethyl (meth) acrylate is preferable. In addition, the alkyl (meth) acrylate which has a hydroxyl group may be used independently, or 2 or more types may be used together.

  The content of the alkyl (meth) acrylate having a hydroxyl group in the monomer composition (I) is preferably 80% by weight or less, and more preferably 60% by weight or less. By making content of the alkyl (meth) acrylate which has a hydroxyl group below the said upper limit, the transparency fall of the hard-coat layer by aggregation of an inorganic particle (B) and organic particle (C) can be suppressed.

  The monomer composition (I) may contain a (meth) acrylate having an alicyclic group. Examples of the (meth) acrylate having an alicyclic group include cyclohexyl (meth) acrylate, 4-butylcyclohexyl (meth) acrylate, dicyclopentanyl (meth) acrylate, dicyclopentenyl (meth) acrylate, and dicyclopenta Examples include dienyl (meth) acrylate, isobornyl (meth) acrylate, and tricyclodecanyl (meth) acrylate.

  The content of the (meth) acrylate having an alicyclic group in the monomer composition (I) is preferably 80% by weight or less, and more preferably 60% by weight or less. By making content of (meth) acrylate which has an alicyclic group below the said upper limit, the fall of the molecular weight of (meth) acrylic-type polymer (A1) is suppressed, and, thereby, blocking resistance and transparency A hard coat layer having excellent properties can be formed.

  A compound having a carboxyl group and a photopolymerizable group is added to the polymer (I ′) having a glycidyl group. Examples of the compound having a carboxyl group and a photopolymerizable group include an ethylenically unsaturated carboxylic acid or an anhydride thereof. Specific examples include acrylic acid, methacrylic acid, ω-carboxy-polycaprolactone monoacrylate, monohydroxyethyl acrylate phthalate and the like, and acrylic acid and methacrylic acid are preferable. In addition, the compound which has a carboxyl group and a photopolymerizable group may be used independently, or 2 or more types may be used together. The carboxyl group possessed by these compounds reacts with the glycidyl group possessed by the polymer (I ′) to form an ester bond and generate a new hydroxyl group. At the same time, the photopolymerizable group can be introduced. Thereby, the (meth) acrylic-type polymer (A1) which has a photopolymerizable group and a hydroxyl group in a side chain is obtained.

  When a compound having a carboxyl group and a photopolymerizable group is added to the polymer (I ′) having a glycidyl group, the glycidyl group in the radical polymerizable monomer having a glycidyl group used for the production of the polymer (I ′) The molar ratio of the carboxyl group in the compound having a carboxyl group and a photopolymerizable group (number of moles of carboxyl group / number of moles of glycidyl group) is preferably 0.3 to 1.5, and preferably 0.5 to 1.2. Is more preferable, and 1.0 is particularly preferable. If the molar ratio is too low, the number of side chain photopolymerizable groups decreases, which may reduce the hardness of the hard coat layer. If the molar ratio is too high, unreacted acid remains, and the water resistance of the hard coat layer may be lowered. Further, as described above, the glycidyl group reacts with the carboxyl group to form an ester bond and generate a hydroxyl group. Therefore, the hydroxyl value of the (meth) acrylic polymer (A1) can be adjusted by adjusting the molar ratio.

  An example of a more specific production method for the production method (2) of the (meth) acrylic polymer (A2) will be described. Radical polymerization of a radically polymerizable monomer having a hydroxyl group and, if necessary, a monomer composition (II) containing an alkyl (meth) acrylate having no hydroxyl group in a reaction vessel in the presence of a radical polymerization initiator. Thus, a polymer (II ′) having a hydroxyl group is produced. Next, a compound having an isocyanate group and a photopolymerizable group and, if necessary, a catalyst are added to the reaction vessel. If necessary, a polymerization inhibitor such as p-methoxyphenol or hydroquinone (HQ) may be added to the reaction vessel. After that, while oxygen is blown into the reaction vessel as necessary, for example, the reaction solution is controlled to be 30 to 150 ° C., and is allowed to react for 6 to 12 hours, thereby photopolymerizing the side chain. A (meth) acrylic polymer (A2) having a functional group and a hydroxyl group can be produced.

  Examples of the radical polymerizable monomer having a hydroxyl group include alkyl (meth) acrylate having a hydroxyl group, acrylic acid N-hydroxymethylamide, methacrylic acid N-hydroxymethylamide, 4-hydroxymethylcyclohexyl (meth) acrylate, and the like. An alkyl (meth) acrylate having an alkyl group is preferred, and an alkyl (meth) acrylate having a hydroxyl group in the alkyl group is more preferred. Examples of the alkyl (meth) acrylate having a hydroxyl group include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 4 -Hydroxybutyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, 8-hydroxyoctyl (meth) acrylate, 10-hydroxydecyl (meth) acrylate, 12-hydroxylauryl (meth) acrylate and the like. In addition, the radically polymerizable monomer which has a hydroxyl group may be used independently, or 2 or more types may be used together.

  As the radical polymerizable monomer having a hydroxyl group, 2-hydroxyethyl (meth) acrylate is preferable, and 2-hydroxyethyl methacrylate (2-HEMA) is more preferable. By using a radically polymerizable monomer having a hydroxyl group, the hydroxyl value of the (meth) acrylic polymer (A2) can be easily adjusted.

  The content of the radical polymerizable monomer having a hydroxyl group in the monomer composition (II) is preferably 10 to 90% by weight, and more preferably 20 to 80% by weight. By setting the content of the radical polymerizable monomer having a hydroxyl group to the above lower limit value or more, a hard coat layer having a high crosslinking density and excellent hardness can be formed. Further, by setting the content of the radical polymerizable monomer having a hydroxyl group to the above lower limit value or more, the inorganic particles (B) and the organic particles (C) are highly dispersed, and thereby the transparency and printability of the hard coat layer. Can also be improved. On the other hand, by setting the content of the radical polymerizable monomer having a hydroxyl group to the upper limit value or less, it is possible to suppress a decrease in the transparency of the hard coat layer due to aggregation of the inorganic particles (B) and the organic particles (C). .

  The monomer composition (II) preferably further contains an alkyl (meth) acrylate having no hydroxyl group. Specific examples of the alkyl (meth) acrylate not having a hydroxyl group include the same alkyl (meth) acrylates having no glycidyl group in the method (1) described above. Of these, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, and butyl (meth) acrylate are preferable.

  10-90 weight% is preferable and, as for content of the alkyl (meth) acrylate which does not have a hydroxyl group in monomer composition (II), 20-80 weight% is more preferable. By suppressing the content of the alkyl (meth) acrylate having no hydroxyl group to the above lower limit or more, the decrease in the transparency of the hard coat layer due to the aggregation of the inorganic particles (B) and the organic particles (C) is suppressed. Can do. On the other hand, the inorganic particles (B) and the organic particles (C) are highly dispersed by setting the content of the alkyl (meth) acrylate having no hydroxyl group to the upper limit value or less, and the transparency of the hard coat layer can be increased. Printability can be improved. Further, by setting the content of alkyl (meth) acrylate having no hydroxyl group to the upper limit value or less, a hard coat layer having a high crosslinking density and excellent hardness can be formed.

  The monomer composition (II) may contain a (meth) acrylate having an alicyclic group. Specific examples of the (meth) acrylate having an alicyclic group include those similar to the (meth) acrylate having an alicyclic group in the method (1) described above.

  The content of the (meth) acrylate having an alicyclic group in the monomer composition (II) is preferably 80% by weight or less, and more preferably 60% by weight or less. By making content of (meth) acrylate which has an alicyclic group below the said upper limit, the fall of the molecular weight of (meth) acrylic-type polymer (A2) is suppressed, and, thereby, blocking resistance and transparency A hard coat layer having excellent properties can be formed.

  A compound having an isocyanate group and a photopolymerizable group is added to the polymer (II ′). By adding a compound having an isocyanate group and a photopolymerizable group to a part of the hydroxyl group of the polymer (II ′), the side chain has a hydroxyl group and a photopolymerizable group (meth) An acrylic polymer (A2) is obtained.

  Examples of the compound having an isocyanate group and a photopolymerizable group include 2-isocyanatoethyl methacrylate (for example, trade name “Karenz MOI” manufactured by Showa Denko KK), 1,1- (bisacryloyloxymethyl). Ethyl isocyanate (for example, trade name “Karenz BEI” manufactured by Showa Denko KK), 2-isocyanatoethyl acrylate (for example, trade name “Karenz AOI” manufactured by Showa Denko KK), (Meta) Examples include (meth) acryloyl isocyanate in which an acryloyl group is bonded to an isocyanate group via an alkylene group having 2 to 6 carbon atoms, and derivatives thereof. Examples of (meth) acryloyl isocyanate include 2-methacryloyloxyethyl isocyanate.

  Examples of the derivative include (meth) acrylate having an isocyanate group masked with a blocking agent. Specific examples include 2- (O- [1′-methylpropylideneamino] carboxyamino) ethyl methacrylate (for example, trade name “Karenz MOI-BM” manufactured by Showa Denko KK), 2-[( 3,5-dimethylpyrazolyl) carbonylamino] ethyl methacrylate (for example, trade name “Karenz MOI-BP” manufactured by Showa Denko KK) and the like. In addition, the compound which has an isocyanate group and a photopolymerizable group may be used independently, or 2 or more types may be used together. Of these, 2-isocyanatoethyl methacrylate is preferable.

  When adding a compound having an isocyanate group and a photopolymerizable group to the polymer (II ′) having a hydroxyl group, the hydroxyl group (—OH) in the radical polymerizable monomer having a hydroxyl group used in the production of the polymer (II ′) is used. ) The mole ratio of the isocyanate group (—NCO) to the mole number (—NCO / —OH) is preferably 0.05 to 0.9, more preferably 0.1 to 0.9. The hydroxyl value of the (meth) acrylic polymer (A2) can also be adjusted by adjusting the molar ratio.

  An example of a more specific production method for the production method (3) of the (meth) acrylic polymer (A3) will be described. A radical polymerizable monomer having a carboxyl group and, if necessary, a monomer composition (III) containing an alkyl (meth) acrylate having no carboxyl group in a reaction vessel in the presence of a radical polymerization initiator. Polymer (III ′) is produced by polymerization. Next, a compound having a glycidyl group and a photopolymerizable group and, if necessary, a catalyst are added to the reaction vessel. If necessary, a polymerization inhibitor such as p-methoxyphenol or hydroquinone (HQ) may be added to the reaction vessel. After that, while oxygen is blown into the reaction vessel as necessary, for example, the reaction solution is controlled to be 30 to 150 ° C., and is allowed to react for 6 to 12 hours, thereby photopolymerizing the side chain. A (meth) acrylic polymer (A3) having a functional group and a hydroxyl group can be produced.

  Examples of the radical polymerizable monomer having a carboxyl group used in the method (3) include an ethylenically unsaturated carboxylic acid or an anhydride thereof. Specifically, α, β-unsaturated carboxylic acids such as acrylic acid, methacrylic acid, itaconic acid, maleic acid, fumaric acid or salts thereof; ω-carboxy-polycaprolactone monoacrylate, phthalic acid monohydroxyethyl acrylate, etc. Acrylic acid and methacrylic acid are preferred. In addition, the radically polymerizable monomer which has a carboxyl group may be used independently, or 2 or more types may be used together.

  The content of the radically polymerizable monomer having a carboxyl group in the monomer composition (III) is preferably 10 to 90% by weight, and more preferably 20 to 80% by weight. By setting the content of the radical polymerizable monomer having a carboxyl group to the above lower limit value or more, a hard coat layer having a high crosslinking density and excellent hardness can be formed. Moreover, gelatinization at the time of the synthesis | combination of a (meth) acrylic-type polymer can be suppressed by making content of the radically polymerizable monomer which has a carboxyl group below into the said upper limit.

  The monomer composition (III) preferably further contains an alkyl (meth) acrylate having no carboxyl group. Specific examples of the alkyl (meth) acrylate having no carboxyl group include the same alkyl (meth) acrylates having no glycidyl group in the above-described method (1).

  The content of the alkyl (meth) acrylate having no carboxyl group in the monomer composition (III) is preferably 10 to 90% by weight, and more preferably 20 to 80% by weight. By making content of the alkyl (meth) acrylate which does not have a carboxyl group more than the said lower limit, gelatinization at the time of the synthesis | combination of a (meth) acrylic-type polymer can be suppressed. Moreover, by setting the content of the alkyl (meth) acrylate having no carboxyl group to the upper limit value or less, a hard coat layer having a high crosslinking density and excellent hardness can be formed.

The monomer composition (III) may contain an alkyl (meth) acrylate having a hydroxyl group. Specific examples of alkyl (meth) acrylates having a hydroxyl group include the same alkyl (meth) acrylates having a hydroxyl group in the method of the above (1). By using an alkyl (meth) acrylate having a hydroxyl group, the hydroxyl value of the (meth) acrylic polymer (A3) can be adjusted.

  The content of the alkyl (meth) acrylate having a hydroxyl group in the monomer composition (III) is preferably 90% by weight or less, more preferably 80% by weight or less, particularly preferably 10 to 90% by weight, and 20 to 80% by weight. Is most preferred. By setting the content of the alkyl (meth) acrylate having a hydroxyl group to the above lower limit or more, the inorganic particles (B) and the organic particles (C) are highly dispersed to improve the transparency and printability of the hard coat layer. be able to. On the other hand, by controlling the content of the alkyl (meth) acrylate having a hydroxyl group to be equal to or lower than the above upper limit value, it is possible to suppress a decrease in transparency of the hard coat layer due to aggregation of the inorganic particles (B) and the organic particles (C). it can.

  The monomer composition (III) may contain a (meth) acrylate having an alicyclic group. Specific examples of the (meth) acrylate having an alicyclic group include those similar to the (meth) acrylate having an alicyclic group in the method (1) described above.

  The content of the (meth) acrylate having an alicyclic group in the monomer composition (III) is preferably 80% by weight or less, and more preferably 60% by weight or less. By making content of (meth) acrylate which has an alicyclic group below the said upper limit, the fall of the molecular weight of (meth) acrylic-type polymer (A3) is suppressed, and, thereby, blocking resistance and transparency A hard coat layer having excellent properties can be formed.

  A compound having a glycidyl group and a photopolymerizable group is added to the polymer (III ′). The carboxyl group possessed by the polymer (III ′) reacts with the glycidyl group possessed by the compound, thereby forming an ester bond and generating a new hydroxyl group. At the same time, the photopolymerizable group can be introduced. As a result, a (meth) acrylic polymer (A3) having a photopolymerizable group such as a vinyl group and a hydroxyl group in the side chain is obtained.

  Specific examples of the compound having a glycidyl group and a photopolymerizable group include glycidyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate glycidyl ether, and allyl glycidyl ether. preferable. In addition, the compound which has a glycidyl group and a photopolymerizable group may be used independently, or 2 or more types may be used together.

  When a compound having a glycidyl group and a photopolymerizable group is added to the polymer (III ′) having a glycidyl group, the carboxyl group in the radical polymerizable monomer having a carboxyl group used for the production of the polymer (III ′) The molar ratio of glycidyl groups in the compound having a glycidyl group and a photopolymerizable group (number of moles of glycidyl group / number of moles of carboxyl group) is preferably 0.3 to 1.5, preferably 0.5 to 1.2. Is more preferable, and 1.0 is more preferable. As described above, the glycidyl group reacts with the carboxyl group to form an ester bond and generate a hydroxyl group. Therefore, the hydroxyl value of the (meth) acrylic polymer (A3) can be adjusted by adjusting the molar ratio.

  In the methods (1) to (3) described above, the monomer composition (I), (II) or (III) is radically polymerized in the presence of a radical polymerization initiator. As the radical polymerization initiator, those generally used in radical polymerization are used. Examples of radical polymerization initiators include organic peroxides such as benzoyl peroxide, lauroyl peroxide, caproyl peroxide, t-hexyl peroxyneodecanate, and t-butyl peroxybivalate; 2,2-azobis- Isobutyronitrile, 2,2-azobis-2,4-dimethylvaleronitrile, 2,2-azobis-4-methoxy-2,4-dimethylvaleronitrile, azobis-2-methylbutyronitrile (Nippon Hydrazine Industries ( An azo compound such as a trade name “ABN-E” manufactured by the company) is preferable, and an azo compound is preferable. In addition, a radical polymerization initiator may be used independently or 2 or more types may be used together.

  As each polymerization method of monomer composition (I), (II), and (III), although a general purpose method is used, emulsion polymerization (including suspension polymerization) and solution polymerization are preferable.

  In emulsion polymerization and solution polymerization, the monomer composition (I), (II) or (III) is polymerized in a solvent. The solvent is not particularly limited as long as it is stable with respect to each of the above-mentioned monomers. For example, petroleum hydrocarbon solvents such as hexane and mineral spirit; aromatic hydrocarbon solvents such as benzene, toluene and xylene; acetone, Ketone solvents such as methyl ethyl ketone, methyl isobutyl ketone, diisobutyl ketone, cyclohexanone; ester solvents such as methyl acetate, ethyl acetate, butyl acetate, γ-butyrolactone, propylene glycol monomethyl ether acetate; N, N-dimethylformamide, N, N -Aprotic polar solvents such as dimethylacetamide, dimethylsulfoxide, N-methylpyrrolidone, pyridine and the like. A solvent may be used independently and 2 or more types may be used together. The mixing ratio of the solvent is not particularly limited and is appropriately set according to the purpose and application.

  Moreover, a commercial item can also be used for a solvent. Specifically, examples of the petroleum hydrocarbon solvent include AF Solvents 4 to 7 manufactured by Nippon Oil Corporation. Examples of the aromatic hydrocarbon solvent include Ink Solvent No. 0 manufactured by Nippon Oil Corporation and Solvesso 100, 150, and 200 manufactured by Exxon Chemical.

  In the methods (1) to (3) described above, it is preferable to add a catalyst to each reactor. Examples of the catalyst include dibutyltin dilaurate, dioctyltin laurate, dioctyltin dilaurate, triphenylphosphine, and a bismuth catalyst.

  Although the hydroxyl value of (meth) acrylic-type polymer (A) is limited to 10-350 mgKOH / g, 30-330 mgKOH / g is preferable and 50-300 mgKOH / g is more preferable. According to the (meth) acrylic polymer (A) having a hydroxyl value equal to or higher than the above lower limit, excellent printability can be imparted to the hard coat layer. Furthermore, according to the (meth) acrylic polymer (A) having a hydroxyl value within the above range, the inorganic particles (B) and the organic particles (C) can be highly dispersed, whereby the inorganic particles (B) and A decrease in the transparency of the hard coat layer due to the addition of the organic particles (C) can be suppressed. In addition, the hydroxyl value of (meth) acrylic-type polymer (A) can be measured by the method as described in the Example mentioned later.

  The (meth) acrylic equivalent of the (meth) acrylic polymer (A) is limited to 100 to 800 g / eq, preferably 200 to 700 g / eq, and more preferably 300 to 600 g / eq. According to the (meth) acrylic polymer (A) whose (meth) acrylic equivalent is not more than the above upper limit value, a hard coat layer having high hardness can be formed. Furthermore, according to the (meth) acrylic polymer (A) having a (meth) acrylic equivalent within the above range, the inorganic particles (B) and the organic particles (C) can be highly dispersed. The decrease in the transparency of the hard coat layer due to the addition of B) or the organic particles (C) can be suppressed.

  The (meth) acrylic equivalent of (meth) acrylic polymer (A) is the (meth) acrylic polymer (A) per mole of (meth) acryloyl group possessed by (meth) acrylic polymer (A). Means the number of grams.

  The (meth) acryl equivalent of the (meth) acrylic polymer (A) can be calculated by the following formula (I) from the monomer composition that is the raw material of the (meth) acrylic polymer (A).

［式中、
（メタ）アクリル系ポリマー（Ａ）の原料に用いたモノマーの全使用量（ｇ）を「Ｗ」とし、
（メタ）アクリル系ポリマー（Ａ）の合成時において、最終的に得られる（メタ）アクリル系ポリマー（Ａ）の主鎖に側鎖として（メタ）アクリロイル基を導入するために用いられたモノマーのうちから、任意に選択されたモノマーのモル数（ｍｏｌ）を「Ｍ」とし、任意に選択された上記モノマー１分子あたりの（メタ）アクリロイル基の個数を「Ｎ」とし、
（メタ）アクリル系ポリマー（Ａ）の合成時において、最終的に得られる（メタ）アクリル系ポリマー（Ａ）の主鎖に側鎖として（メタ）アクリロイル基を導入するために用いられたモノマー種の数を「ｋ」とする。］

[Where:
The total amount (g) of monomers used as the raw material for the (meth) acrylic polymer (A) is “W”,
In the synthesis of the (meth) acrylic polymer (A), the monomer used to introduce the (meth) acryloyl group as a side chain into the main chain of the (meth) acrylic polymer (A) finally obtained Among them, the number of moles (mol) of an arbitrarily selected monomer is “M”, the number of (meth) acryloyl groups per one molecule of the arbitrarily selected monomer is “N”,
Monomer species used to introduce a (meth) acryloyl group as a side chain into the main chain of the (meth) acrylic polymer (A) finally obtained during the synthesis of the (meth) acrylic polymer (A) Is the number “k”. ]

  The weight average molecular weight of the (meth) acrylic polymer (A) is limited to 10,000 to 200,000, preferably 30,000 to 170,000, more preferably 50,000 to 150,000, 65 1 to 150,000 is particularly preferable. The (meth) acrylic polymer (A) having a weight average molecular weight within the above range can disperse the inorganic particles (B) and the organic particles (C) highly, and has excellent blocking resistance and transparency. A code layer can be formed.

  The weight average molecular weight of the (meth) acrylic polymer (A) can be measured by polystyrene conversion using a gel permeation chromatograph (GPC). Specifically, the measurement of the weight average molecular weight using GPC can be performed as follows. First, the molecular weight distribution of the (meth) acrylic polymer (A) is measured by a gel permeation chromatograph (GPC) equipped with a differential refractive index detector (RID) to obtain a chromatogram (chart). From this chromatogram, the weight average molecular weight of the (meth) acrylic polymer (A) can be calculated using standard polystyrene as a calibration curve. In addition, the weight average molecular weight of a (meth) acrylic-type polymer (A) can be measured by the method as described in the Example mentioned later.

  Although the glass transition point (Tg) of (meth) acrylic-type polymer (A) is limited to 50-110 degreeC, 55-107 degreeC is preferable and 60-105 degreeC is more preferable. According to the (meth) acrylic polymer (A) having a glass transition point equal to or higher than the above lower limit, a hard coat layer having high hardness and excellent scratch resistance and blocking resistance can be formed. Moreover, according to the (meth) acrylic polymer (A) having a glass transition point within the above range, the inorganic particles (B) and the organic particles (C) can be highly dispersed, and the blocking resistance and transparency can be improved. An excellent hard code layer can be formed. The glass transition point of the (meth) acrylic polymer (A) can be calculated by Fox's equation.

  The (meth) acrylic polymer (A) preferably contains 10 to 90% by weight of an alkyl (meth) acrylate component as a monomer component. Such a (meth) acrylic polymer (A) can be obtained by radical polymerization of a monomer composition containing 10 to 90% by weight of alkyl (meth) acrylate. According to the alkyl (meth) acrylate component, the organic particles (C) can be highly dispersed, whereby the transparency of the hard coat layer can be improved.

  The alkyl (meth) acrylate used as the monomer component preferably has no glycidyl group or hydroxyl group. Specific examples of the alkyl (meth) acrylate include ethyl (meth) acrylate, methyl (meth) acrylate, n-butyl (meth) acrylate, hexyl acrylate, 2-ethylbutyl (meth) acrylate, isooctyl (meth) acrylate, 2 -Ethylhexyl (meth) acrylate, decyl (meth) acrylate, dodecyl (meth) acrylate, etc. are mentioned. Of these, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, and butyl (meth) acrylate are preferable, and methyl (meth) acrylate is more preferable. According to methyl (meth) acrylate, not only can the organic particles (C) be highly dispersed, but also a hard coat layer having high hardness can be formed.

  The content of the alkyl (meth) acrylate component in the (meth) acrylic polymer (A) is preferably 10 to 90% by weight, more preferably 20 to 80% by weight, particularly preferably 30 to 80% by weight, and 40 to 40%. 70% by weight is most preferred. That is, the content of the alkyl (meth) acrylate in the monomer composition is preferably 10 to 90% by weight, more preferably 20 to 80% by weight, particularly preferably 30 to 80% by weight, most preferably 40 to 70% by weight. preferable. By setting the content of the alkyl (meth) acrylate component within the above range, a hard coat layer excellent in transparency and hardness can be formed.

  The content of the (meth) acrylic polymer (A) in the photocurable resin composition is (meth) acrylic polymer (A), inorganic particles (B), organic particles (C), and photopolymerizable multifunctional. Although limited to 10-40 weight% with respect to the total weight of a compound (D), 12-37 weight% is preferable and 15-35 weight% is more preferable. By making content of (meth) acrylic-type polymer (A) more than the said lower limit, an inorganic particle (B) and organic particle (C) can be disperse | distributed highly, and, thereby, it becomes blocking resistance and transparency. An excellent hard code layer can be formed. By setting the content of the (meth) acrylic polymer (A) to the upper limit value or less, high hardness of the hard coat layer can be ensured.

(Inorganic particles (B))
The photocurable resin composition of the present invention contains at least one kind of inorganic particles (B). According to the inorganic particles (B), a hard coat layer having high hardness and excellent scratch resistance and blocking resistance can be formed. Furthermore, polar groups such as hydroxyl groups are often present on the surface of the inorganic particles (B). The (meth) acrylic polymer (A) having a predetermined hydroxyl value described above also has a hydroxyl group in the side chain. Therefore, the inorganic particles (B) and the (meth) acrylic polymer (A) are close in polarity to each other, and electrostatic repulsion is suppressed. Therefore, the inorganic particles (B) can be highly dispersed by using the (meth) acrylic polymer (A), thereby suppressing the decrease in the transparency of the hard coat layer due to the addition of the inorganic particles (B). However, the scratch resistance and blocking resistance of the hard coat layer can be improved. In addition, the said mechanism is guessed by this inventor etc., Therefore, this invention is not limited to the said mechanism.

  Examples of the inorganic particles (B) include metal particles, metal oxide particles, metal sulfate particles, metal silicate particles, metal phosphate particles, metal carbonate particles, metal hydroxide particles, and fluorine compound particles. It is done. Among these, metal particles and metal oxide particles are preferable, and metal oxide particles are more preferable. The metal particles and the metal oxide particles are close in polarity to the (meth) acrylic polymer (A), and thus can be highly dispersed by the (meth) acrylic polymer (A). An inorganic particle (B) may be used individually by 1 type, and 2 or more types may be used together.

  Examples of the metal contained in the metal particles include Si, Ti, Mg, Ca, Zr, Sn, Sb, As, Zn, Nb, In, and Al. Examples of the metal oxide contained in the metal oxide particles include oxides of metals such as Si, Ti, Mg, Ca, Zr, Sn, Sb, As, Zn, Nb, In, and Al. Specific examples of the metal oxide particles include silicon oxide particles, titanium oxide particles, aluminum oxide particles, tin oxide particles, indium oxide particles, ITO particles, zinc oxide particles, zirconium oxide particles, and magnesium oxide particles. In addition, for example, fine particles of a different element doped metal oxide in which a different element such as Ab, Sn, F, P, Al or the like is doped into these metal oxide particles may be used.

  As the inorganic particles (B), silicon oxide particles, aluminum oxide particles, zirconium oxide particles, and titanium oxide particles are preferable, and silicon oxide particles are more preferable.

  As the inorganic particles (B), inorganic particles dispersed in a colloidal form can be used. The inorganic particles (B) may be surface-treated by a known method.

  The shape of the inorganic particles (B) is not particularly limited, and examples thereof include a lump shape, a spherical shape, a hollow shape, a porous shape, a rod shape, a plate shape, a fiber shape, and an indefinite shape. You may use combining the inorganic particle (B) of a different shape.

  Although the average particle diameter of an inorganic particle (B) is limited to 10 nm-500 nm, 10 nm-400 nm are preferable and 10 nm-200 nm are more preferable. In the inorganic particles (B) having an average particle size of less than the lower limit, it is difficult to achieve high dispersion, and the transparency and blocking resistance of the hard coat layer may be reduced. Moreover, in the inorganic particle (B) whose average particle diameter exceeds the above upper limit, there is a possibility that the transparency, hardness, blocking resistance and printability of the hard coat layer may be lowered. In the photocurable resin composition, the inorganic particles (B) exist as aggregated particles such as primary particles or secondary particles. Therefore, the average particle diameter of the inorganic particles (B) is a value measured by a measurement method described later.

In addition, the measurement of the average particle diameter of an inorganic particle (B) can be performed as follows. First, the photocurable resin composition is diluted with methyl isobutyl ketone to obtain a diluted solution. In addition, the density | concentration of the inorganic particle (B) in a dilution liquid shall be 0.1 to 1 weight%. Next, the volume particle size distribution of the inorganic particles (B) is measured using a diluted solution with a laser light diffraction / scattering particle size distribution measuring device (for example, Nanotrac UPA-EX150 manufactured by Nikkiso Co., Ltd.). The cumulative value of 50% can be calculated as the average particle diameter of the inorganic particles (B). Specific measurement conditions are as shown below. The measured value of the average particle diameter of the inorganic particles obtained under the following measurement conditions is defined as the average particle diameter of the inorganic particles (B).
Number of measurements: 1 Measurement time: 180 seconds Measurement temperature: 23 ° C
Measurement solvent: methyl isobutyl ketone CI value: 0.4 to 0.8
Particle permeability: Transmission Sensitivity: Standard Filter: Stand: Norm
Nano range correction: Invalid

  The content of inorganic particles (B) in the photocurable resin composition is (meth) acrylic polymer (A), inorganic particles (B), organic particles (C), and photopolymerizable polyfunctional compound (D). Although it is limited to 5 to 40% by weight, the amount is preferably 6 to 35% by weight and more preferably 7 to 30% by weight. If the content of the inorganic particles (B) is less than the above lower limit, there is a possibility that excellent blocking resistance cannot be imparted to the hard coat layer. Moreover, when content of an inorganic particle (B) exceeds the said upper limit, there exists a possibility that the transparency and printability of a hard-coat layer may fall. Furthermore, if the content of the inorganic particles (B) exceeds the above upper limit, the hard coat layer may become too hard and cracks may easily occur.

(Organic particles (C))
The photocurable resin composition of the present invention contains at least one kind of organic particles (C). In the present invention, the printability of the hard coat layer can be improved by using the inorganic particles (B) and the organic particles (C) in combination in the presence of the (meth) acrylic polymer (A). The mechanism for obtaining such an effect is not clear, but can be estimated as follows. In addition, the following mechanism is guessed by this inventor etc., Therefore, this invention is not limited to the following mechanism.

  As described above, the inorganic particles (B) can be highly dispersed by the hydroxyl groups of the (meth) acrylic polymer (A), but the presence of the inorganic particles (B) allows the hydroxyl groups of the (meth) acrylic polymer (A) to be dispersed. Many will exist toward the inside of the hard coat layer. The organic particles (C) have hydrophobicity, and the hydrophobicity of the organic particles (C) contributes to the dispersion of the inorganic particles (B) among the hydroxyl groups of the (meth) acrylic polymer (A). Unexposed hydroxyl groups can be present toward the outside of the hard coat layer. Therefore, by using the inorganic particles (B) and the organic particles (C) in combination in the presence of the (meth) acrylic polymer (A), the number of hydroxyl groups existing on the outer surface of the hard coat layer is increased. be able to. Since such a hard coat layer has a large number of hydroxyl groups on the surface thereof, the conformability to ink is improved, thereby enabling printing with high accuracy without repelling the ink.

  Examples of the organic particles (C) include particles containing a synthetic resin. Synthetic resins include polyamide resins, polyamideimide resins, polyacetal resins, (meth) acrylic resins, melamine resins, (meth) acrylic-styrene copolymers, polycarbonate resins, styrene resins, polyvinyl chloride resins. Examples include resins, benzoguanamine-melamine formaldehyde, silicone resins, fluorine resins, polyester resins, crosslinked (meth) acrylic resins, crosslinked polystyrene resins, crosslinked polyurethane resins, and epoxy resins. An organic particle (C) may be used individually by 1 type, and 2 or more types may be used together.

  Among these, as the organic particles (C), (meth) acrylic resin particles are preferable, and polyalkyl (meth) acrylate particles are more preferable. Since the (meth) acrylic resin particles have low polarity, many hydroxyl groups of the (meth) acrylic polymer (A) can be present on the hard coat layer surface. As polyalkyl (meth) acrylate particles, polymethyl (meth) acrylate particles, polyethyl (meth) acrylate particles, polypropyl (meth) acrylate particles, polybutyl (meth) acrylate particles, polypentyl (meth) acrylate particles, polyhexyl (meth) Acrylate particles, polyheptyl (meth) acrylate particles, polyoctyl (meth) acrylate particles, poly 2-ethylhexyl (meth) acrylate particles, polynonyl (meth) acrylate particles, polydecyl (meth) acrylate particles, polybenzyl (meth) acrylate particles, And polydicyclopentadienyl (meth) acrylate particles. Of these, polymethyl (meth) acrylate particles are preferable.

  Although the average particle diameter of organic particle | grains (C) is limited to 10 nm-500 nm, 10 nm-400 nm are preferable and 50 nm-300 nm are more preferable. The organic particles (C) having an average particle diameter within the above range are hardly dispersed in the hydroxyl groups of the (meth) acrylic polymer (A) that do not contribute to the dispersion of the inorganic particles (B). It can exist toward the outer side of a coating layer. Thereby, a hard coat layer having many hydroxyl groups on the surface can be formed. Further, the organic particles (C) having an average particle diameter exceeding the above upper limit may reduce the transparency and hardness of the hard coat layer.

  In addition, the measurement of the average particle diameter of an organic particle (C) can be performed in the same way as the measuring method of the average particle diameter of the inorganic particle (B) mentioned above. In the photocurable resin composition, the organic particles (C) are present as aggregated particles such as primary particles or secondary particles. Therefore, let the average particle diameter of organic particle (C) be the value measured by the same method as the measuring method of the average particle diameter of inorganic particle (B) mentioned above. In addition, the density | concentration of the organic particle (C) in a dilution liquid shall be 0.1 to 1 weight%.

  The content of the organic particles (C) in the photocurable resin composition is (meth) acrylic polymer (A), inorganic particles (B), organic particles (C), and photopolymerizable polyfunctional compound (D). Although it is limited to 0.5-10 weight% with respect to the total weight of, 0.7-9 weight% is preferable and 1-8 weight% is more preferable. By setting the content of the organic particles (C) to the above lower limit value or more, a hard coat layer excellent in blocking resistance and printability can be formed. Moreover, the outstanding transparency of a hard-coat layer is securable by making content of an organic particle (C) below into the said upper limit.

(Photopolymerizable polyfunctional compound (D))
The photocurable resin composition of the present invention contains at least one photopolymerizable polyfunctional compound (D) having two or more photopolymerizable groups in one molecule. The photopolymerizable polyfunctional compound (D) can be radically polymerized with the (meth) acrylic polymer (A). As a result, the photopolymerizable polyfunctional compound (D) can crosslink between the molecular chains of the (meth) acrylic polymer (A) to form a dense network structure. Inorganic particles (B) and organic particles (C) can be taken into such a dense network structure, whereby inorganic particles (B) and organic particles (C) are highly dispersed while suppressing their aggregation. A hard coat layer can be formed. Such a hard coat layer is excellent in transparency, blocking resistance, and printability because the inorganic particles (B) and the organic particles (C) are highly dispersed.

  The photopolymerizable group contained in the photopolymerizable polyfunctional compound (D) has an ethylenically unsaturated double bond capable of radical polymerization with the photopolymerizable group of the (meth) acrylic polymer (A). And an acryloyl group, a methacryloyl group, a styryl group, a vinyl group, an allyl group, etc. are mentioned, and an acrylolyl group and a methacryloyl group are preferable.

  Examples of the photopolymerizable polyfunctional compound (D) having two photopolymerizable groups in one molecule include ethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, and neopentyl glycol di (meth). Alkylene glycol di (meth) acrylate such as acrylate; polyalkylene glycol di (meth) acrylate such as diethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, tripropylene glycol di (meth) acrylate (Meth) acrylate; 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, 1,9-nonanediol di (meth) acrylate, dicyclopentadiene di (meth) Chryrate, neopentyl glycol adipate di (meth) acrylate, hydroxypivalic acid neopentyl glycol di (meth) acrylate, tricyclodecane dimethanol di (meth) acrylate, dicyclopentanyl di (meth) acrylate; pentaerythritol di (meta) ) Acrylate, bisphenol AEO addition diacrylate, caprolactone-modified dicyclopentenyl di (meth) acrylate, ethylene oxide-modified phosphoric acid di (meth) acrylate, allylated cyclohexyl di (meth) acrylate, isocyanurate di (meth) acrylate or alkylene thereof Modified oxide, divinylbenzene, butanediol-1,4-divinyl ether, cyclohexanedimethanol divinyl ether, diethyleneglycol Rudivinyl ether, dipropylene glycol divinyl ether, dipropylene glycol divinyl ether, hexanediol divinyl ether, triethylene glycol divinyl ether, phenylglycidyl ether acrylate hexamethylene diisocyanate urethane oligomer (trade name “AH-600” manufactured by Kyoeisha Chemical Co., Ltd.) And phenyl glycidyl ether acrylate toluene diisocyanate urethane oligomer (trade name “AT-600” manufactured by Kyoeisha Chemical Co., Ltd.). In addition, a photopolymerizable polyfunctional compound (D) may be used independently, or 2 or more types may be used together.

  Examples of the photopolymerizable polyfunctional compound (D) having three photopolymerizable groups in one molecule include trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, and dipentaerythritol tri (meta). ) Acrylate, tris (acryloxyethyl) isocyanurate, or their modified alkylene oxide, and isocyanuric acid alkylene oxide modified tri (meth) acrylate.

  Examples of the photopolymerizable polyfunctional compound (D) having four photopolymerizable groups in one molecule include ditrimethylolpropane tetra (meth) acrylate, pentaerythritol tetra (meth) acrylate, and their alkylene oxide modified products. Etc.

  Examples of the photopolymerizable polyfunctional compound (D) having five photopolymerizable groups in one molecule include dipentaerythritol penta (meth) acrylate or a modified alkylene oxide thereof.

  Examples of the photopolymerizable polyfunctional compound (D) having six photopolymerizable groups in one molecule include dipentaerythritol hexa (meth) acrylate, pentaerythritol triacrylate hexamethylene diisocyanate urethane oligomer (Kyoeisha Chemical Co., Ltd.) Trade name “UA-306H”), caprolactone-modified dipentaerythritol hexa (meth) acrylate, or an alkylene oxide-modified product thereof.

  As the photopolymerizable polyfunctional compound (D), an oligomer having two or more photopolymerizable groups in one molecule is preferable. Examples of the oligomer include urethane (meth) acrylate, polyester (meth) acrylate, and epoxy (meth) acrylate. Of these, urethane (meth) acrylate oligomers are more preferable. The urethane (meth) acrylate oligomer is obtained by reacting an isocyanate group-terminated urethane prepolymer obtained by reacting polyols and polyisocyanate with a (meth) acrylate monomer having at least one hydroxyl group in one molecule. .

  Examples of the urethane (meth) acrylate oligomer include phenyl glycidyl ether acrylate hexamethylene diisocyanate urethane oligomer, phenyl glycidyl ether acrylate toluene diisocyanate urethane oligomer, and pentaerythritol triacrylate hexamethylene diisocyanate urethane oligomer.

  The number of photopolymerizable groups that the photopolymerizable polyfunctional compound (D) has in one molecule is preferably 3 to 20, more preferably 4 to 20, and particularly preferably 5 to 15. According to the photopolymerizable polyfunctional compound (D) in which the number of photopolymerizable groups is within the above range, a dense cross-linked structure can be formed, thereby improving transparency, hardness, blocking resistance and printability. An excellent hard coat layer can be provided.

  The content of the photopolymerizable polyfunctional compound (D) in the photocurable resin composition is (meth) acrylic polymer (A), inorganic particles (B), organic particles (C), and photopolymerizable polyfunctional. Although it is limited to 20 to 70% by weight relative to the total weight of compound (D), it is preferably 23 to 65% by weight, and more preferably 25 to 60% by weight. By setting the content of the photopolymerizable polyfunctional compound (D) to the above lower limit value or more, excellent hardness of the hard coat layer can be ensured. Moreover, by making content of a photopolymerizable polyfunctional compound (D) below the said upper limit, an inorganic particle (B) and an organic particle (C) are highly dispersed, Thereby, transparency and blocking resistance In addition, a hard coat layer excellent in printability can be formed.

(Photopolymerization initiator)
It is preferable that the photocurable resin composition of the present invention further contains a photopolymerization initiator. Examples of photopolymerization initiators include benzoin ether photopolymerization initiators, benzophenone photopolymerization initiators, thioxanthone photopolymerization initiators, alkylphenone photopolymerization initiators, acylphosphine oxide photopolymerization initiators, and titanocenes. And photopolymerization initiators, oxime ester photopolymerization initiators, diazophenylamine photopolymerization initiators, naphthoquinone diazosulfonic acid photopolymerization initiators, and dimethylaminobenzoic acid photopolymerization initiators. In addition, a photoinitiator may be used independently or 2 or more types may be used together.

  Examples of the benzoin ether photopolymerization initiator include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, and benzoin isobutyl ether.

  Examples of the benzophenone photopolymerization initiator include benzophenone, methyl o-benzoylbenzoate, 4-phenylbenzophenone, 4-benzoyl-4′-methyl-diphenyl sulfide, and 2,4,6-trimethylbenzophenone.

  Examples of the thioxanthone photopolymerization initiator include 2-isopropylthioxanthone, 2,4-diethylthioxanthone, 2,4-dichlorothioxanthone, 1-chloro-4-propoxythioxanthone, and the like.

  Examples of the alkylphenone photopolymerization initiator include 2-hydroxy-2-methyl-1-phenyl-propan-1-one, 2,2-dimethoxy-1,2-diphenylethane-1-one, and 1-hydroxy. -Cyclohexyl-phenyl-ketone, 1- [4- (2-hydroxyethoxy) -phenyl] -2-hydroxy-2-methyl-1-propan-1-one, 2-hydroxy-1- {4- [4- (2-hydroxy-2-methyl-propionyl) -benzyl] phenyl} -2-methyl-propan-1-one, 2-methyl-1- (4-methylthiophenyl) -2-morpholinopropan-1-one, 2-Benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1,2- (dimethylamino) -2-[(4-methylphenyl) me Le] -1- [4- (4-morpholinyl) phenyl] -1-butanone and the like.

  Examples of the acylphosphine oxide photopolymerization initiator include 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, and the like.

  Examples of the titanocene-based photopolymerization initiator include bis (η5-2,4-cyclopentadien-1-yl) -bis (2,6-difluoro-3- (1H-pyrrol-1-yl) -phenyl) titanium. Etc.

  Examples of the oxime ester photopolymerization initiator include 1,2-octanedione-1- [4- (phenylthio) -2- (O-benzoyloxime)] and ethanone-1- [9-ethyl-6- ( 2-methylbenzoyl) -9H-carbazol-3-yl] -1- (O-acetyloxime), oxy-phenyl-acetic acid 2- [2-oxo-2-phenylacetoxyethoxy] ethyl ester, oxy-phenyl -Acetic acid 2- (2-hydroxyethoxy) ethyl ester etc. are mentioned.

  As for content of the photoinitiator in a photocurable resin composition, 0.1-20 weight part is preferable with respect to 100 weight part of (meth) acrylic-type polymers (A), 0.1-10 weight part Is more preferable, and 1 to 5 parts by weight is particularly preferable. By making content of a photoinitiator more than the said lower limit, photocuring of a photocurable resin composition can fully be advanced. Moreover, the fall of the hardness of the hard-coat layer by the decomposition product of a photoinitiator can be suppressed by making content of a photoinitiator below the said upper limit.

(Photopolymerizable monofunctional compound)
The photocurable resin composition of the present invention may contain a photopolymerizable monofunctional compound having one photopolymerizable group in one molecule. The photopolymerizable monofunctional compound is used for adjusting the viscosity of the photocurable resin composition and improving the drying property of the photocurable resin composition by increasing the solid content concentration.

  Examples of the photopolymerizable monofunctional compound include aliphatic (meth) acrylates, alicyclic (meth) acrylates, aromatic (meth) acrylates, ether (meth) acrylates, vinyl monomers, (meth) Examples include acrylamides. In the present invention, (meth) acrylamide means acrylamide or methacrylamide.

As the photopolymerizable monofunctional compounds, for example, 2-hydroxyethyl (meth) acrylate, 2-hydroxy-3-acryloyloxypropyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, cyclo hexyl ( (Meth) acrylate, isooctyl (meth) acrylate, isomyristyl (meth) acrylate, isostearyl (meth) acrylate, isobornyl (meth) acrylate, ethoxy-diethylene glycol (meth) acrylate, 2-ethylhexyl-carbitol (meth) acrylate, neo Pentyl glycol benzoate (meth) acrylate, nonylphenoxypolyethylene glycol (meth) acrylate, ECH modified phenoxy (meth) acrylate, phenoxyethyl ( Data) acrylate, p-cumylphenol ethylene oxide-modified (meth) acrylate, vinyl pyrrolidone, vinyl caprolactam, and the like acryloyl morpholine.

(Surfactant)
The photocurable resin composition of the present invention may contain a surfactant. By using the surfactant, the printability of the hard coat layer can be improved.

  Examples of the surfactant include an anionic surfactant, a cationic surfactant, a nonionic surfactant, and an amphoteric surfactant. It is preferable that the surfactant has a functional group having active hydrogen. Examples of the functional group having active hydrogen include a hydroxyl group, a carboxyl group, an amino group, and an amide group.

  Examples of the anionic surfactant include castor oil monosulfate, castor oil monophosphate, sorbitan fatty acid ester sulfate, sorbitan fatty acid ester phosphate, polyoxyalkylene glycerin ether monosulfate, polyoxyalkylene glycerin ether monophosphate, perfluoroalkyl ester. Examples include phosphate.

  Examples of the cationic surfactant include dialkanol amine salts, polyoxyalkylene alkyl amine ether salts, polyoxyalkylene alkyl ammonium salts, polyoxyalkylene dialkanol amine ether salts, and the like.

  Examples of nonionic surfactants include polyoxyethylene polyoxypropylene block polymers, sorbitan fatty acid esters, polyoxyalkylene sorbitan fatty acid esters, and polyglycerin fatty acid esters.

  Examples of amphoteric surfactants include N, N-di (β-hydroxyalkyl) N-hydroxyethyl-N-carboxyalkylammonium betaine, N, N-di (polyoxyethylene) -N-alkyl-N-sulfo. Examples include alkyl ammonium betaine and perfluoroalkyl betaine.

(Silane coupling agent)
The photocurable resin composition of the present invention may contain a silane coupling agent. By using a silane coupling agent, the printability of the hard coat layer can be improved.

  Examples of the silane coupling agent include epoxy group-containing silane coupling agents such as glycidoxypropyltrimethoxysilane and glycidoxypropyltriethoxysilane; aminopropyltrimethoxysilane, N-2- (aminoethyl) -3 -Amino group-containing silane coupling agents such as aminopropyltriethoxysilane and aminopropyltriethoxysilane; Mercapto group-containing silane coupling agents such as mercaptopropyltrimethoxysilane; Urethane group-containing silane couplings such as ureidopropyltriethoxysilane Agents; isocyanate group-containing silane coupling agents such as isocyanatepropyltriethoxysilane.

  The photocurable resin composition of the present invention may contain a solvent. By using the solvent, the viscosity of the photocurable resin composition can be adjusted, and thereby the handleability and coating properties of the photocurable resin composition can be improved. The solvent is not particularly limited, and examples thereof include the same solvents as those used for the polymerization of the monomer composition in the above-described emulsion polymerization and solution polymerization.

  In the photocurable resin composition of the present invention, other additives may be added as necessary within the range not impairing the physical properties. Examples of other additives include antioxidants, light stabilizers, heat stabilizers, antistatic agents, and antifoaming agents.

  The photocurable composition of the present invention is preferably used for forming a cured film on one surface of a substrate. A cured film obtained by curing the photocurable composition is excellent in transparency, hardness, scratch resistance, blocking resistance, and printability. Therefore, such a cured film can be used as a hard coat layer.

  As a method for forming a cured film of the photocurable resin composition, a step of applying the photocurable resin composition to at least one surface of the substrate and irradiating the applied photocurable resin composition with active energy rays And a step of photocuring to obtain a cured film. Examples of the active energy ray include ultraviolet rays, electron beams, α rays, β rays, and γ rays, and ultraviolet rays and electron beams are preferable. When irradiating an active energy ray to the photocurable resin composition which does not contain a photopolymerization initiator, an electron beam is preferably used as the active energy ray.

  Ultraviolet irradiation can be performed using an ultraviolet irradiation apparatus having a light source such as a xenon lamp, a high-pressure mercury lamp, and a metal halide lamp. When a high pressure mercury lamp is used as the light source, the substrate coated with the photocurable resin composition may be conveyed at a conveyance speed of 5 to 50 m / min with respect to one high pressure mercury lamp and irradiated with ultraviolet rays. preferable. At this time, the light quantity of the high pressure mercury lamp is preferably 80 to 160 W / cm.

  When an electron beam is used as the light source, the substrate coated with the photocurable resin composition is preferably conveyed at 5 to 50 m / min using an electron beam accelerator having an acceleration voltage of 10 to 300 kV. It is preferable that the electron beam is irradiated at a speed.

  The material of the substrate is not particularly limited, and examples thereof include polyester resins such as polyethylene terephthalate and polybutylene terephthalate, polycarbonate resins, polyacrylic resins, styrene resins, ABS resins, triacetyl cellulose, and olefin resins. And synthetic resins such as glass, inorganic materials such as glass, and metals such as stainless steel, steel, and aluminum.

  As a method for applying the photocurable resin composition to the substrate, for example, a coating method such as a dip coating method, a spray coating method, a roll coating method, a doctor blade method, a screen printing method, a bar coater, an applicator or the like is used. Casting that had been mentioned.

  Although the film thickness of the coating film after drying of the photocurable resin composition apply | coated on the base material is not specifically limited, 2-90 micrometers is preferable and 5-50 micrometers is more preferable.

  You may remove the solvent etc. which are contained in the photocurable resin composition by heating the applied photocurable resin composition before light irradiation.

  As described above, the cured film of the photocurable resin composition can be used in combination with inorganic particles (B) and organic particles (C), such as hardness, scratch resistance, blocking resistance, transparency, and printability. Physical properties have been improved. Originally, the inorganic particles and the organic particles have different refractive indexes, and when the inorganic particles and the organic particles are used in combination, the inorganic particles and the organic particles are likely to aggregate due to electrostatic repulsion between them. As a result, the combined use of inorganic particles and organic particles reduces the transparency of the cured film. However, in the present invention, the inorganic particles (B) and the organic particles (C) are used in combination by highly dispersing the inorganic particles (B) and the organic particles (C) using the (meth) acrylic polymer (A). It is possible to reduce the decrease in transparency of the cured film due to high.

  The cured film of the photocurable resin composition has excellent transparency. The haze of the cured film of the photocurable resin composition is preferably 1.0% or less, and more preferably 0.8% or less. The haze of the cured film is a value measured according to JIS K 7136 (2000).

  The cured film of the photocurable resin composition has excellent hardness. The hardness of the cured film of the photocurable resin composition is preferably H or higher, more preferably 2H or higher, as pencil hardness. In addition, pencil hardness says the value measured by the pencil hardness test based on JISK5600-5-4 (1999).

  The cured film of the photocurable resin composition has a low coefficient of dynamic friction and excellent blocking resistance. The dynamic friction coefficient of the cured film of the photocurable resin composition is preferably 0.6 N or less, and more preferably 0.5 N or less. The dynamic friction coefficient is a value measured in accordance with JIS K 7125 (1999).

  The cured film of the photocurable resin composition has excellent compatibility with ink, and printability is improved. 35 dyn / cm or more is preferable and, as for the wetting tension of the cured film surface of a photocurable resin composition, 40 dyn / cm or more is more preferable. In addition, let the wetting tension | tensile_strength of the cured film surface of a photocurable resin composition be a value measured based on JISK6768 (1999).

  The thickness of the cured film of the photocurable resin composition is preferably 2 to 90 μm, more preferably 5 to 50 μm, from the viewpoint of obtaining a cured film having excellent hardness, scratch resistance, blocking resistance, and printability.

  The cured film of the photocurable resin composition of the present invention is suitably used for protecting the substrate surface as a hard coat layer. It is preferable that functional layers other than the hard coat layer are laminated and integrated on the cured film. Since the cured film of the photocurable resin composition has excellent printability, a functional layer having a desired pattern shape and uniform thickness can be formed on the cured film.

  Examples of the functional layer include an electromagnetic wave shielding layer, a heat ray reflective layer, an ultraviolet ray shielding layer, a gas barrier layer, an antireflection layer, a conductive layer, a hard coat protective layer, an antiglare layer, an adhesive layer, and an antistatic layer. These functional layers can be formed by a known method.

  For example, a conductive laminated film in which a transparent conductive layer is laminated and integrated on a cured film of a photocurable resin composition is suitably used for a touch panel. Since the cured film of the photocurable resin composition of the present invention is excellent not only in printability but also in transparency, it has a fine pattern shape on such a cured film and has excellent transparency. The transparent conductive layer can be formed, thereby providing a conductive laminated film in which the transparent conductive layer is hardly visible and has high visible light transmittance.

  The conductive laminated film includes a transparent substrate, a cured film of a photocurable resin composition laminated and integrated on one surface of the transparent substrate, and a transparent conductive layer laminated and integrated on one surface of the cured film. Including.

  The transparent substrate contains a transparent synthetic resin. Transparent synthetic resins include polyester resins, acetate resins, polyethersulfone resins, polycarbonate resins, polyamide resins, polyimide resins, polyolefin resins, (meth) acrylic resins, polyvinyl chloride resins, poly Examples thereof include vinylidene chloride resins, polystyrene resins, polyvinyl alcohol resins, polyarylate resins, polyphenylene sulfide resins, and the like. The thickness of the transparent substrate is preferably 2 to 200 μm, more preferably 2 to 100 μm.

  The transparent conductive layer may be laminated and integrated on the cured film of the photocurable resin composition via an adhesive layer. The adhesive layer contains a known adhesive. As the adhesive, for example, an acrylic adhesive, a silicone adhesive, a polyester adhesive, or the like is used. By applying a composition containing an adhesive on the cured film, an adhesive layer having a uniform thickness can be formed.

  The constituent material of the transparent conductive layer is, for example, at least one selected from the group consisting of indium, tin, zinc, gallium, antimony, titanium, silicon, zirconium, magnesium, aluminum, gold, silver, copper, palladium, and tungsten. Examples include metal oxides. The transparent conductive layer has a pattern shape such as a stripe shape depending on the application in which the conductive laminated film is used.

  A known method is used as a method for forming the transparent conductive layer. For example, a method of printing a conductive paste is preferable. As described above, the cured film of the photocurable resin composition has high polarity due to the presence of many hydroxyl groups on the surface. Thereby, the cured film of a photocurable resin composition and a transparent conductive layer can be firmly laminated and integrated. Therefore, the method for forming the transparent conductive layer is not limited to the printing method, and an evaporation method, a sputtering method, and the like are also preferably used.

  The conductive laminated film is suitably used for a capacitive touch panel. The touch panel is not particularly limited, but is disposed on the front surface of the display panel of the information terminal device. Examples of the information terminal device include a mobile phone, a personal digital assistant (PDA), a portable game machine, a digital camera, a personal computer, and a television.

  Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited thereto.

(Example Synthesis Examples 1-9 and Comparative Synthesis Examples 1-8)
Synthesis of (meth) acrylic polymer In a reaction vessel, 400 parts by weight of methyl isobutyl ketone (MIBK) was supplied as a solvent and heated to 90 ° C. and maintained.

  Methyl methacrylate (MMA), isobornyl methacrylate (IBXMA), glycidyl methacrylate (GMA), 2-hydroxyethyl methacrylate (2-HEMA), butyl acrylate (BA), and azobis-2-methylbutyroyl as radical polymerization initiator Nitrile (ABN-E) was mixed in the blending amounts shown in Tables 1 and 2 to obtain a monomer composition.

  Next, the monomer composition is gradually dropped into the reaction vessel over 2 hours, mixed, allowed to stand for 4 hours, and then heated at 120 ° C. for 1 hour for radical polymerization. To obtain a polymer.

  Next, after the polymer was cooled to 60 ° C., acrylic acid (AA), 2-isocyanatoethyl methacrylate (MOI), paramethoxyphenol (MQ) as a polymerization inhibitor, and triphenylphosphine ( TPP) and dibutyltin dilaurate (DBTDL) were mixed in the blending amounts shown in Tables 1 and 2, respectively, to obtain a mixture. The mixture is then heated at 110 ° C. for 8 hours while oxygen is being blown into the reaction vessel to add acrylic acid (AA) or 2-isocyanatoethyl methacrylate (MOI) to the polymer. A (meth) acrylic polymer having a photopolymerizable group and a hydroxyl group in the chain was produced.

  The hydroxyl value, (meth) acryl equivalent, weight average molecular weight, and glass transition point of the obtained (meth) acrylic polymer were measured as follows. The results are shown in Tables 1 and 2.

(Hydroxyl value)
The hydroxyl value of the (meth) acrylic polymer is determined by the method of 4.2B of JIS K1557-1: 2007 (ISO 14900: 2001) “Plastics—Polyurethane raw material polyol test method—Part 1: Determination of hydroxyl value”. Measured in conformity. In addition, the hydroxyl value of a (meth) acrylic-type polymer means the hydroxyl value of solid content.

((Meth) acrylic equivalent)
The (meth) acrylic equivalent of the (meth) acrylic polymer was calculated by the above formula (I) from the monomer composition that is the raw material of the (meth) acrylic polymer.

(Weight average molecular weight)
A 0.2 mg sample was taken from a (meth) acrylic polymer, dissolved in 10 ml of tetrahydrofuran, and the molecular weight distribution of the sample was determined by gel permeation chromatography (GPC) equipped with a differential refractive index detector (RID). Measurement was performed to obtain a chromatogram (chart).

Next, the weight average molecular weight and number average molecular weight of the sample were calculated from the obtained chromatogram (chart) using standard polystyrene as a calibration curve. The measurement apparatus and measurement conditions are shown below.
Data processor: Product name HLC-8220GPC (manufactured by Tosoh Corporation)
Differential refractive index detector: Product name RI detector built in HLC-8220GPC Column: Product name TSKgel GMH _XL (manufactured by Tosoh Corporation) 3 Mobile phase: Tetrahydrofuran Column flow rate: 0.5 mL / min
Injection volume: 20 μL
Measurement temperature: 40 ° C
Standard polystyrene molecular weight: 1250, 3250, 9200, 28500, 68000, 165000, 475000, 950,000, 1900000

(Glass transition point)
The glass transition point of the (meth) acrylic polymer was calculated by Fox's formula.

(Examples 1 to 25 and Comparative Examples 1 to 20)
In the compounding amounts shown in Tables 3 to 7, as the inorganic particles (B), silicon oxide particles (B1) having an average particle size (MD) of 10 nm, silicon oxide particles (B2) having an average particle size of 100 nm, average Silicon oxide particles (B3) having a particle diameter of 400 nm, titanium oxide particles (B4) having an average particle diameter of 100 nm, zirconium oxide particles (B5) having an average particle diameter of 100 nm, silicon oxide having an average particle diameter of 1000 nm As particles (B6) and organic particles (C), polymethyl methacrylate (PMMA) particles (C1) having an average particle size of 20 nm, polymethyl methacrylate (PMMA) particles (C2) having an average particle size of 100 nm, average particles Polymethylmethacrylate (PMMA) particles (C3) having a diameter of 400 nm, styrene type having an average particle diameter of 100 nm Fatty particles (C4), melamine resin particles (C5) having an average particle size of 100 nm, polymethyl methacrylate (PMMA) particles (C6) having an average particle size of 1000 nm, and pentaerythritol as a photopolymerizable polyfunctional compound (D) Triacrylate hexamethylene diisocyanate urethane oligomer (trade name “UA-306H” of Kyoeisha Chemical Co., Ltd.) and methyl isobutyl ketone were uniformly mixed to prepare a premixed solution.

  In the premixed solution, the (meth) acrylic polymer produced in Examples Synthesis Examples 1 to 9 and Comparative Synthesis Examples 1 to 8 is 10 minutes so that the blending amounts shown in Tables 3 to 7 are obtained in terms of solid content. It was dripped gradually over the time. After completion of the dropping, the premixed solution was stirred at 30 ° C. for 30 to 60 minutes.

  Next, Tables 3 to 7 show 2-hydroxy-2-methyl-1-phenyl-propan-1-one (BASF product name “DAROCUR 1173”) as a photopolymerization initiator in the stirred premixed solution. A photo-curable resin composition was obtained by adding them in a blended amount and mixing them. In addition, when each average particle diameter of the inorganic particles (B1) to (B6) and the organic particles (C1) to (C6) in the obtained photocurable resin composition was measured by the measurement method described above, each average particle was measured. The measured value of the diameter was the same value as the above average particle diameter of the inorganic particles (B1) to (B6) and the organic particles (C1) to (C6) used for the preparation of the premixed liquid.

The photocurable resin composition was applied onto a polyethylene terephthalate (PET) film using a bar coater so that the dry film thickness was 5 μm. Thereafter, the photocurable resin composition was heated at 80 ° C. for 2 minutes to remove the solvent, and then the photocurable resin composition was integrated at 500 mJ / cm ² using a high-pressure mercury lamp (light quantity 120 W / cm). The photocurable resin composition was photocured by irradiating ultraviolet rays with a light amount to form a cured film (thickness 5 μm).

[Evaluation]
The appearance, pencil hardness, haze, blocking resistance, and printability of the cured film were evaluated according to the following procedures. The results are shown in Table 3-7.

(appearance)
The appearance of the cured film was evaluated according to the test method of 4.4 “Appearance of coating film” of JIS K 5600-1-1. In Tables 3 to 7, “excellent” and “inferior” are as shown below.
Excellent: The cured film was colorless and transparent, and no crack was generated.
Inferior: In the cured film, at least one of occurrence of white turbidity and occurrence of cracks occurred.

(Pencil hardness)
The pencil hardness of the cured film was measured by a pencil hardness test in accordance with JIS K 5600-5-4 (1999).

(Haze)
The haze (%) of the cured film was measured with a haze meter in accordance with JIS K 7136 (2000).

(Blocking resistance)
Two PET films on which a cured film was formed were prepared. These PET films were laminated so that the cured films faced to obtain a laminate. The laminated body was heated at 80 ° C. for 12 hours while applying a 5 kg load on the laminated body. Thereafter, one PET film was pulled in a direction parallel to the cured film surface at a tensile speed of 10 mm / min, and the dynamic friction coefficient (N) at this time was measured according to JIS K 7125 (1999).

(Printability)
The printability of the cured film was evaluated by measuring the wetting tension (dyn / cm) of the cured film surface in accordance with JIS K 6768 (1999).

  According to the present invention, there is provided a photocurable resin composition capable of forming a hard coat layer having improved blocking resistance without lowering transparency and also having excellent printability. can do.

Claims (6)

The hydroxyl value is 10 to 350 mg KOH / g, the (meth) acryl equivalent is 100 to 800 g / eq, the weight average molecular weight is 10,000 to 200,000, and the glass transition point is 50 to 110 ° C. (Meth) acrylic polymer (A) having a photopolymerizable group and a hydroxyl group in the side chain;
Inorganic particles (B) having an average particle diameter of 10 nm to 500 nm;
Organic particles (C) having an average particle diameter of 10 nm to 500 nm;
A photopolymerizable polyfunctional compound (D) having two or more photopolymerizable groups in one molecule;
And the total weight of the (meth) acrylic polymer (A), the inorganic particles (B), the organic particles (C), and the photopolymerizable polyfunctional compound (D),
The content of the (meth) acrylic polymer (A) is 10 to 40% by weight,
The content of the inorganic particles (B) is 5 to 40% by weight,
The content of the organic particles (C) is 0.5 to 10% by weight,
Content of the said photopolymerizable polyfunctional compound (D) is 20 to 70 weight%, The photocurable resin composition characterized by the above-mentioned.   The photocurable resin composition according to claim 1, wherein the (meth) acrylic polymer (A) contains 10 to 90% by weight of an alkyl (meth) acrylate component.   The photocurable resin composition according to claim 1, wherein the inorganic particles (B) are at least one of metal particles and metal oxide particles.   The photocurable resin composition according to claim 1, wherein the organic particles (C) are (meth) acrylic resin particles.   The photocurable resin composition according to claim 1, comprising a photopolymerization initiator.   A cured film obtained by curing the photocurable resin composition according to claim 1.