JP4998647B2 - Active energy ray-curable resin composition, cured product and film thereof - Google Patents

Description

  The present invention particularly relates to an active energy ray-curable resin composition that can be preferably used to form a hard coat layer that protects the surface of a touch panel.

  In recent years, devices equipped with touch panel displays are increasing in mobile phones, game machines, car navigation systems, and the like. In touch panel displays that are operated by touching the screen directly with a finger, the fingerprint marks that adhere to the hard coat layer that protects the surface, in addition to the screen's clarity and surface hardness, are less likely to adhere. What is called fingerprint resistance, such as being difficult and easy to wipe off attached fingerprint marks, is required. However, the conventional hard coat layer, which emphasizes screen clarity and surface hardness, has a problem that fingerprints are easily attached because the surface is flat, and the attached fingerprints are conspicuous and difficult to wipe off. .

  Thus, as a composition for obtaining a hard coat layer in which fingerprint marks are not easily noticeable and attached fingerprint marks are easy to wipe off, for example, polypropylene glycol having a weight average molecular weight (Mw) of 2,000, isophorone diisocyanate, and penta A photo-curable resin composition containing urethane acrylate having one acryloyl group at one end, obtained by reacting 1 mol each of erythritol triacrylate, is known (for example, see Patent Document 1). However, although the coating film made of the photocurable composition disclosed in Patent Document 1 has a surface hardness equivalent to that of a normal hard coat, both the conspicuousness of fingerprints and the ease of wiping off attached fingerprint traces are obtained. Sufficient performance was not obtained. In particular, regarding the ease of wiping off fingerprints, when the photocurable resin composition is cured in an air atmosphere, it is affected by the inhibition of curing of the coating film surface by peroxy radicals generated from oxygen present in the air, and thus a nitrogen atmosphere. There was a problem that the ease of wiping off fingerprint marks was greatly reduced as compared with the case of curing underneath.

JP2008-255301 (2nd page)

  The problem to be solved by the present invention is that the cured coating film has a high level of fingerprint resistance and surface hardness, and even when the environment during curing is in an air atmosphere, the performance can be expressed. An active energy ray-curable resin composition, a cured product obtained by curing the composition, and a film having a cured layer of the composition are provided.

  As a result of intensive studies, the present inventors have found that polyalkylene glycol having a weight average molecular weight (Mw) in the range of 500 to 5,000 and a diol having an alkylene thioether structure in the molecular structure as essential raw material components. By using a resin composition containing urethane (meth) acrylate obtained by reaction, a hard coat layer is obtained in which fingerprint traces are not noticeable even when cured in an air atmosphere, and the attached fingerprints are easy to wipe off. In addition, the present inventors have found that a cured layer obtained by curing the composition exhibits high hardness and completed the present invention.

  That is, the present invention relates to a polyalkylene glycol (a1) having a weight average molecular weight (Mw) in the range of 500 to 5,000, a diol (a2) having an alkylene thioether structure in the molecular structure, and a molecular weight of 500 or less. The weight average molecular weight (Mw) obtained by reacting a certain diisocyanate (a3) with (meth) acrylate (a4) having one hydroxyl group in the molecular structure as an essential raw material component is 10,000 to 100,000. An active energy ray-curable resin composition characterized by containing a urethane (meth) acrylate (A) and a polyfunctional (meth) acrylate (B) in the above range.

  The present invention also provides a cured product obtained by curing the active energy ray-curable resin composition.

  Furthermore, this invention provides the film characterized by having the cured layer formed by hardening | curing the said active energy ray hardening-type resin composition on a film-form base material.

  By using the active energy ray-curable resin composition of the present invention, it is possible to form a hard coat layer having a high surface hardness, less noticeable fingerprint marks, and easy to wipe off the attached fingerprints. Therefore, the active energy ray-curable resin composition of the present invention is suitable as a composition for forming a hard coat layer of an article to which fingerprint marks such as a touch panel display are easily attached.

The present invention is described in detail below.
The urethane (meth) acrylate (A) used in the present invention includes a polyalkylene glycol (a1) having a weight average molecular weight (Mw) in the range of 500 to 5,000, and a diol (a2) having an alkylene thioether structure in the molecular structure. ), Diisocyanate (a3) having a molecular weight in the range of 100 to 500, and (meth) acrylate (a4) having one hydroxyl group in the molecular structure are reacted as essential raw material components. .

  Here, the polyalkylene glycol (a1) which is a raw material component of the urethane (meth) acrylate (A) has a weight average molecular weight (Mw) in the range of 500 to 5,000. When the weight average molecular weight (Mw) is less than 500, sufficient performance cannot be exhibited in terms of difficulty of conspicuous adhesion of the attached fingerprint, and when it exceeds 5,000, the attached fingerprint can be easily wiped off. Is not fully expressed. Among the polyalkylene glycols (a1), the compatibility with the fingerprint component is excellent, the compatibility with the polyfunctional (meth) acrylate (B) is good, and a coating film with higher hardness can be obtained. The weight average molecular weight (MW) is preferably in the range of 700 to 4,500, and the weight average molecular weight (Mw) is more preferably in the range of 1,000 to 4,000.

In the present invention, the weight average molecular weight (Mw) and the number average molecular weight (Mn) are values measured by gel permeation chromatography (GPC) under the following conditions.
Measuring device: HLC-8220GPC manufactured by Tosoh Corporation
Column: TSK-GUARDCOLUMN SuperHZ-L manufactured by Tosoh Corporation
+ Tosoh Corporation TSK-GEL SuperHZM-M x 4
Detector: RI (differential refractometer)
Data processing: Multi-station GPC-8020 model II manufactured by Tosoh Corporation
Measurement conditions: Column temperature 40 ° C
Solvent tetrahydrofuran
Flow rate: 0.35 ml / min standard; monodisperse polystyrene sample; 0.2 wt% tetrahydrofuran solution in terms of resin solids filtered through a microfilter (100 μl)

  The number of polyalkyleneoxy structural units derived from the polyalkylene glycol (a1) contained in the urethane (meth) acrylate (A) varies depending on the weight average molecular weight (Mw) of the polyalkylene glycol used, but it is easy to adapt to the fingerprint property. In addition, since a resin composition excellent in both the compatibility with the polyfunctional (meth) acrylate (B) and the surface hardness of the coating film is obtained, the range of 1 to 20 is preferable, and 2 to 10 A range is more preferred. In particular, when the weight average molecular weight (Mw) of the polyalkylene glycol (a1) is in the range of 1,000 to 4,000, it is preferably 2 to 6.

  Examples of the polyalkylene glycol (a1) include polyethylene glycol, polypropylene glycol, polytetramethylene glycol, polybutylene glycol, and poly-3-chloropropylene glycol. These may be used alone or in combination of two or more. Among these, polypropylene glycol and polybutylene glycol are preferable, and polypropylene glycol is more preferable because a hard coat layer in which fingerprint marks are hardly noticeable is obtained.

  In the present invention, as described above, by using the diol (a2) having an alkylene thioether structure in the molecular structure as a raw material component of the urethane (meth) acrylate (A), any curing condition in a nitrogen atmosphere or an air atmosphere is used. Even so, it is possible to obtain a cured coating film excellent in ease of fingerprint wiping.

  Examples of the diol (a2) having an alkylene thioether structure in the molecular structure used in the present invention include 2,2′-thiodiethanol, 3-thia-1,6-hexanediol, 1- (2-hydroxyethylthio)- 2-propanol, 4-methyl-2-thiapentane-1,5-diol, 1-chloro-3- (2-hydroxyethylthio) -2-propanol, 3,3′-thiobis (1-propanol), 2, 2′-thiobis (1-propanol), 1,1′-thiobis (2-propanol), 5-methyl-3-thiahexane-1,6-diol, 3-oxa-6-thiaoctane-1,8-diol, etc. A compound having one sulfur atom in its molecular structure;

  2,2 ′-(methylenebisthio) diethanol, 1,2-bis (2-hydroxyethylthio) ethane, 3,3′-dithiobis (1-propanol), 1,1′-dithiobis (2-propanol), Bis (2-hydroxy-1-methylethyl) persulfide, 2,2 ′-[oxybis (methylenethio)] bisethanol, 3,9-dithia-6-oxanonane-1,9-diol, 2,2 ′-( Trimethylenebisthio) diethanol, 2,2 ′-(tetramethylenebisthio) diethanol, 4,4′-dithiobis (1-butanol), 1,1 ′-(ethylenebisthio) bis (2-propanol), 3 -[2- (3-hydroxypropylsulfanyl) ethylsulfanyl] propan-1-ol, 2,2 '-[oxybis (ethylenethio)] di Tanol, 2,2 ′-[(2-methyl-1,4-butanediyl) bis (thio)] bisethanol, 2,2 ′-(pentamethylenebisthio) diethanol, 2,2 ′-(hexamethylenebisthio) ) Diethanol, 1,1 ′-(ethylenebisthio) bis (2-butanol), 3,3′-dithiobis (3-methyl-2-butanol), bis (5-hydroxypentyl) persulfide, 4,9- Dithiadecane-1,12-diol, 1- (2- [2- (2-hydroxypropylsulfanyl) ethoxy] ethylsulfanyl) propan-2-ol, 2,2 ′-[ethylenebis (oxyethylenethio)] diethanol, 2,2 ′-(oxyethylenethioethyleneoxyethylenethio) diethanol, 2,2 ′-(octamethylenebisthio) die Diol, 6,6′-dithiobis (1-hexanol), 4,11-dithiatetradecane-1,14-diol, bis [1- (hydroxymethyl) -1-ethylpropyl] persulfide, 2- [9- (2-hydroxyethylthio) nonylthio] a compound having two sulfur atoms in the molecular structure such as ethanol, thiadenol, 2,2 ′-(1,10-decandiylbisthio) diethanol;

  2,2 ′-[thiobis (ethylenethio)] diethanol, 2,2 ′-[thioethyleneoxyethylene (dithio)] diethanol, 1- (2- [2- (2-hydroxypropylsulfanyl) ethylsulfanyl] ethylsulfanyl) Propan-2-ol, 2- [2- [2- (2-hydroxyethylthio) propylthio] -1-methylethylthio] ethanol, 6-oxa-3,9,12-trithia-1,14-tetradecanediol 1- (2- [2- (2-hydroxypropylsulfanyl) propylsulfanyl] 1-methyl-ethylsulfanyl) propan-2-ol, 2,2 ′-[thiobis (ethyleneoxyethylenethio)] diethanol, 3, 12-dioxa-6,9,15-trithia-1,17-heptadecanediol and the like Compounds having three sulfur atoms in the molecular structure;

  2,2 ′-[1,2-ethanediylbis (dithio)] bisethanol, 2- [2- [2- (2-hydroxyethylthio) ethyldithio] ethylthio] ethanol, 3,6,9,12-tetrathiatetradecane Examples thereof include compounds having 4 sulfur atoms in the molecular structure such as -1,14-diol.

  Among these, the compound represented by the following general formula (1) or general formula (2) is preferable in that the balance between curability of the coating film in an air atmosphere and fingerprint resistance is excellent.

（式中Ｒ１、Ｒ２はそれぞれ炭素原子数が１〜４のアルキル基又はハロゲン化アルキル基である。）

(In the formula, R1 and R2 are each an alkyl group having 1 to 4 carbon atoms or a halogenated alkyl group.)

（式中ｌ、ｍ、ｎはそれぞれ０又は１であり、Ｒ１、Ｒ２、Ｒ３、Ｒ４、Ｒ５、Ｒ６はそれぞれ炭素原子数が１〜４のアルキル基又はハロゲン化アルキル基である。また、Ｘは硫黄原子又は酸素原子であり、化合物中に含まれるＸのうちの半数以上が硫黄原子である。）

(In the formula, l, m, and n are each 0 or 1, and R1, R2, R3, R4, R5, and R6 are each an alkyl group or halogenated alkyl group having 1 to 4 carbon atoms. Is a sulfur atom or an oxygen atom, and more than half of X contained in the compound is a sulfur atom.)

  Specific examples of the compound represented by the general formula (1) include, for example, 2,2′-thiodiethanol, 3-thia-1,6-hexanediol, 1- (2-hydroxyethylthio) -2-propanol 4-methyl-2-thiapentane-1,5-diol, 1-chloro-3- (2-hydroxyethylthio) -2-propanol, 3,3′-thiobis (1-propanol), 2,2′- Molecular structures such as thiobis (1-propanol), 1,1′-thiobis (2-propanol), 5-methyl-3-thiahexane-1,6-diol, 3-oxa-6-thiaoctane-1,8-diol Compound having one sulfur atom in it; 2,2 ′-(methylenebisthio) diethanol, 1,2-bis (2-hydroxyethylthio) ethane, 2,2 ′-[oxybis (methyl) Thio)] bisethanol, 2,2 ′-(trimethylenebisthio) diethanol, 2,2 ′-(tetramethylenebisthio) diethanol, 1,1 ′-(ethylenebisthio) bis (2-propanol), 3 -[2- (3-hydroxypropylsulfanyl) ethylsulfanyl] propan-1-ol, 2,2 '-[oxybis (ethylenethio)] diethanol, 1,1'-(ethylenebisthio) bis (2-butanol), 4,9-dithiadecane-1,12-diol, 1- (2- [2- (2-hydroxypropylsulfanyl) ethoxy] ethylsulfanyl) propan-2-ol, 2,2 ′-[ethylenebis (oxyethylenethio) )] Diethanol, 2,2 '-(oxyethylenethioethyleneoxyethylenethio) diethanol, etc. Compound having two sulfur atoms in the structure; 2,2 ′-[thiobis (ethylenethio)] diethanol, 1- (2- [2- (2-hydroxypropylsulfanyl) ethylsulfanyl] ethylsulfanyl) propan-2-ol 2- [2- [2- (2-hydroxyethylthio) propylthio] -1-methylethylthio] ethanol, 6-oxa-3,9,12-trithia-1,14-tetradecanediol, 1- (2 -[2- (2-hydroxypropylsulfanyl) propylsulfanyl] 1-methyl-ethylsulfanyl) propan-2-ol, 2,2 '-[thiobis (ethyleneoxyethylenethio)] diethanol, 3,12-dioxa-6 , 9,15-trithia-1,17-heptadecanediol, etc. Compounds having four sulfur atoms in the molecular structure such as 3,6,9,12-tetrathiatetradecane-1,14-diol.

  Furthermore, among the above compounds, 2,2′-thiobis (1-propanol) and 1,2-bis (2-hydroxy) are superior in terms of the balance between curability of the coating film in an air atmosphere and fingerprint resistance. Ethylthio) ethane, 2- [2- [2- (2-hydroxyethylthio) propylthio] -1-methylethylthio] ethanol, 1- (2- [2- (2-hydroxypropylsulfanyl) propylsulfanyl] 1 -Methyl-ethylsulfanyl) propan-2-ol is particularly preferred.

  The diisocyanate (a3) used in the present invention has a molecular weight of 500 or less. When the molecular weight exceeds 500, fingerprint resistance of the coating film is not sufficiently exhibited. Among these, those having a molecular weight in the range of 150 to 450 are more preferable in that the coating film has excellent fingerprint resistance. Examples of such diisocyanates include aromatic diisocyanates and aliphatic diisocyanates.

  Examples of the aromatic diisocyanate include tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), p-phenylene diisocyanate, naphthalene diisocyanate, xylylene diisocyanate (XDI), and tetramethylxylylene diisocyanate (TMXDI).

  The aliphatic diisocyanate is a chain diisocyanate such as hexamethylene diisocyanate (HMDI), 2,2,4-trimethylhexane diisocyanate and lysine diisocyanate; 1,4-cyclohexane diisocyanate (CDI), isophorone diisocyanate (IPDI), 4,4 '-Dicyclohexylmethane diisocyanate (hydrogenated MDI), methylcyclohexane diisocyanate, isopropylidene dicyclohexyl-4,4'-diisocyanate, 1,3-diisocyanatomethylcyclohexane (hydrogenated XDI), 4-methyl-1,3-cyclohexyl Examples thereof include cycloaliphatic diisocyanates such as silylene isocyanate (hydrogenated TDI) and norbornane diisocyanate.

  Each of the diisocyanates (a3) may be used alone or in combination of two or more. Among them, aromatic diisocyanate or alicyclic diisocyanate is preferable in that the obtained urethane (meth) acrylate (A) is a compound having excellent compatibility with the polyfunctional (meth) acrylate (B), tolylene diisocyanate, 4, 4'-dicyclohexylmethane diisocyanate and isophorone diisocyanate are more preferred.

  The (meth) acrylate (a4) having one hydroxyl group in the molecular structure used in the present invention is, for example, hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate, 2-hydroxy- Hydroxy (meth) acrylate having one (meth) acryloyl group such as 3-phenoxypropyl (meth) acrylate; glycerin di (meth) acrylate, pentaerythritol tri (meth) acrylate, ditrimethylolpropane tri (meth) acrylate, di Examples thereof include hydroxy (meth) acrylate having two or more (meth) acryloyl groups such as pentaerythritol penta (meth) acrylate and sorbitol penta (meth) acrylate. These may be used alone or in combination of two or more.

  Among these, hydroxy (meth) acrylate having one (meth) acryloyl group is preferable, since a hard coat layer in which the attached fingerprint trace is not noticeable and the attached fingerprint can be easily wiped off is preferable, and hydroxyethyl (meth) An acrylate and a hydroxypropyl (meth) acrylate are more preferable.

  The method for producing the urethane (meth) acrylate (A) used in the present invention includes, for example, a polyalkylene glycol (a1) having a weight average molecular weight in the range of 500 to 5,000 and the alkylene thioether structure in the molecular structure. In the step (Step 1) for producing an isocyanate group-containing urethane prepolymer obtained by reacting the diol (a2) having a diisocyanate (a3) with the urethane prepolymer and the molecular structure The method by the process (process 2) with which (meth) acrylate (a4) which has one hydroxyl group is made to react is mentioned.

  The production method of the isocyanate group-containing urethane prepolymer will be described in detail with respect to the step 1. For example, the polyalkylene glycol (a1), the diol (a2) having an alkylene thioether structure in the molecular structure, and the diisocyanate (a3) Can be reacted in the presence of 500 ppm of tin (II) octoate as a urethanization catalyst and 300 ppm of the polymerization inhibitor methoquinone at a temperature of 70 to 120 ° C.

  In the step 1, the molar ratio [(a1) / (a2)] of the polyalkylene glycol (a1) and the diol (a2) having an alkylene thioether structure in the molecular structure is cured in an air atmosphere. In this case, a hard coat layer that can easily wipe off the attached fingerprint is obtained, and therefore, it is preferably in the range of [1.0 / 0.2] to [1.0 / 5.0]. The range of 0 / 0.5] to [1.0 / 2.0] is more preferable.

In Step 1, the number of moles of hydroxyl groups in the polyalkylene glycol (a1) is F ₁ , the number of moles of hydroxyl groups in the diol (a2) having an alkylene thioether structure in the molecular structure is F ₂ , diisocyanate ( the number of moles of isocyanate groups in a3) and F _3, the ratio of the number of moles and the isocyanate groups of the hydroxyl groups contained in the system _{[(F 1 + F 2) /} F 3 ] is [1/1 .05] to [1/3], and more preferably [1 / 1.1] to [1/2].

  The step 2 will be described in detail. For example, the isocyanate group-containing urethane prepolymer and the (meth) acrylate (a4) having one hydroxyl group in the molecular structure are mixed with octoate tin (II) which is a urethanization catalyst. ) Is added in the range of 300 to 800 ppm, and methoquinone, which is a polymerization inhibitor, is added in the range of 100 to 500 ppm, and the reaction is performed at a temperature of 80 ° C.

In the first step 2, the ratio of the number of moles F _NCO of isocyanate groups in the isocyanate group-containing urethane prepolymer to the number of moles F _OH of hydroxyl groups in the (meth) acrylate having a hydroxyl group in the molecular structure [F _NCO / F _OH ] is preferably in the range of [1/1] to [1 / 1.2], and more preferably in the range of [1 / 1.01] to [1 / 1.05].

  The urethane (meth) acrylate (A) thus obtained is a resin excellent in all of compatibility with the fingerprint property, the hardness of the coating film, and the compatibility with the polyfunctional (meth) acrylate (B). Since the composition is obtained, the weight average molecular weight (Mw) is in the range of 10,000 to 100,000. Among these, the range of 20,000 to 80,000 is more preferable in that a coating film having an excellent balance between the performance of both the conspicuousness of attached fingerprints and the ease of wiping can be obtained.

The polyfunctional (meth) acrylate (B) used in the present invention includes a monomer-type polyfunctional (meth) acrylate (b1) having a molecular weight of less than 600, and an oligomer-type polyfunctional (meth) acrylate having a molecular weight in the range of 600 to 3,000. A functional (meth) acrylate (b2) is used in combination . Examples of monomer-type polyfunctional (meth) acrylate (b1) having a molecular weight of less than 600 include butanediol di (meth) acrylate, hexanediol di (meth) acrylate, ethoxylated hexanediol di (meth) acrylate, and propoxylation Hexanediol di (meth) acrylate, diethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, ethoxylated neopentyl glycol di (meth) acrylate Di (meth) acrylates such as hydroxypivalic acid neopentyl glycol di (meth) acrylate;

Trimethylolpropane tri (meth) acrylate, ethoxylated trimethylolpropane tri (meth) acrylate, propoxylated trimethylolpropane tri (meth) acrylate, tris 2-hydroxyethyl isocyanurate tri (meth) acrylate, glycerin tri (meth) acrylate Tri (meth) acrylates such as;

Pentaerythritol tri (meth) acrylate, dipentaerythritol tri (meth) acrylate, ditrimethylolpropane tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, dipentaerythritol tetra (meth) Tetrafunctional or higher functional (meth) acrylates such as acrylate, dipentaerythritol penta (meth) acrylate, ditrimethylolpropane penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, ditrimethylolpropane hexa (meth) acrylate;

And the (meth) acrylate etc. which substituted a part of above-mentioned various polyfunctional (meth) acrylate with the alkyl group and (epsilon) -caprolactone, etc. are mentioned.

  Among the monomer-type polyfunctional (meth) acrylates (b1), a coating film having higher hardness can be obtained, and therefore, a tetrafunctional or higher functional (meth) acrylate is preferable. Dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate Is more preferable. Furthermore, a mixture (b56) of dipentaerythritol pentaacrylate (b5) and dipentaerythritol hexaacrylate (b6) is particularly preferred from the viewpoint of excellent surface hardness and curl resistance of the coating film. The mass ratio [(b5) / (b6)] of erythritol pentaacrylate (b5) to dipentaerythritol hexaacrylate (b6) is preferably in the range of 3/7 to 7/3, and 4/6 to 5 /. A range of 5 is more preferable.

  The oligomer type polyfunctional (meth) acrylate (b2) has a weight average molecular weight (Mw) in the range of 600 to 3,000, so that a coating film having excellent surface hardness and curl resistance can be obtained. It is done. Examples of the oligomer type polyfunctional (meth) acrylate (b2) include polyester (meth) acrylate, urethane (meth) acrylate, epoxy (meth) acrylate, and acrylic (meth) acrylate. These polyfunctional (meth) acrylates (B) may be used alone or in combination of two or more. Among these, polyfunctional urethane (meth) acrylate (b4) is preferable in that a coating film having higher hardness can be obtained.

The polyfunctional urethane (meth) acrylate (b4) used as the oligomer type polyfunctional (meth) acrylate (b2) is, for example, a polyisocyanate and a polyfunctional (meth) acrylate having a hydroxyl group in the molecular structure. The ratio [F _NCO / F _OH ] of the number of moles F _NCO of isocyanate groups in the isocyanate to the number of moles F _OH of hydroxyl groups in the (meth) acrylate having a hydroxyl group in the molecular structure is [1/1] to [ It can be obtained by reacting to be in the range of [1 / 1.2].

  Examples of the polyisocyanate include various diisocyanates listed as the diisocyanate (a3). Examples of the polyfunctional (meth) acrylate having a hydroxyl group in the molecular structure include various (meth) acrylates listed as (meth) acrylate (a4) having one hydroxyl group in the molecular structure. . Among these, urethane (meth) acrylate obtained by reacting hexamethylene diisocyanate and pentaerythritol tri (meth) acrylate is preferable because a coating film having higher hardness can be obtained.

Among the polyfunctional (meth) acrylates (B) used in the present invention, dipentadiene is used as the monomer-type polyfunctional (meth) acrylate (b1) in that the coating film has excellent hardness, transparency, and curl resistance. It is preferable to use a urethane (meth) acrylate (b4) as the oligomer-type polyfunctional (meth) acrylate using a mixture (b56) of erythritol pentaacrylate (b5) and dipentaerythritol hexaacrylate (b6). The mass ratio [(b56) / (b4)] is preferably in the range of [1/2] to [2-1].

  In the present invention, the urethane (meth) acrylate (A) and the polyfunctional (meth) acrylate (B) have a mass ratio [(A) / (B)] of [0.1 / 99.9] to [15]. / 85] to be included. By using the urethane (meth) acrylate (A) in the above range, it is possible to obtain a hard coat layer in which the attached fingerprint trace is not noticeable without lowering the hardness of the hard coat layer and the attached fingerprint can be easily wiped off. It is done. Urethane (meth) acrylate (A) and polyfunctional (meth) acrylate (B) may be contained in a mass ratio [(A) / (B)] in the range of 0.1 / 99.9 to 10/90. Preferably, it is contained in the range of 0.1 / 99 to 5/95 by mass ratio [(A) / (B)].

  The active energy ray-curable resin composition of the present invention may be mixed with an organic solvent as long as the effects of the present invention are not impaired. As an organic solvent, those having a boiling point of 50 to 200 ° C. are usually used to obtain a resin composition for active energy ray-curable coatings and an active energy ray-curable paint that are excellent in workability during coating and drying before and after curing. For example, alcohol solvents such as methanol, isopropyl alcohol, n-butanol and isobutanol; methyl acetate, ethyl acetate, butyl acetate, ethylene glycol monoethyl ether, ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether Examples thereof include ester solvents such as acetate; ketone solvents such as acetone, methyl ethyl ketone, and methyl isobutyl ketone; aromatic solvents such as toluene and xylene, or mixtures thereof.

  When the active energy ray-curable resin composition obtained in the present invention contains an organic solvent, for example, the active energy ray-curable resin composition for coating is applied to a support and the active energy ray-curable resin composition is applied on the support. After forming the layer of the resin composition, it is preferable to remove the organic solvent before irradiating the layer with active energy rays. As a means for removing the organic solvent, for example, a hot air dryer or the like can be used. The amount of the organic solvent used is not particularly limited, but is usually in the range where the solid content concentration of the paint is 10 to 70% by weight.

  A photopolymerization initiator can be added to the active energy ray-curable resin composition of the present invention depending on the purpose. Various photopolymerization initiators can be used. Examples of the photoinitiator include compounds that generate radicals by hydrogen abstraction, such as benzophenone, benzyl, Michler ketone, thioxanthone, and anthraquinone. These compounds are generally used in combination with tertiary amines such as methylamine, diethanolamine, N-methyldiethanolamine, and tributylamine.

  Furthermore, examples of the photopolymerization initiator include compounds of a type that generates radicals by intramolecular cleavage. Specific examples include benzoin, dialkoxyacetophenone, acyloxime ester, benzyl ketal, hydroxyalkylphenone, halogenoketone and the like.

  Further, if necessary, a polymerization inhibitor such as hydroquinone, benzoquinone, tolhydronoquinone, paratertiary butylcatechol, etc. can be added in combination with a photopolymerization initiator.

  In addition, for the purpose of improving the smoothness of the coating film surface, various leveling agents such as fluorine, silicone and hydrocarbon are added in an amount that does not impair fingerprint resistance (0.005 to 1% by mass). Can be added. Furthermore, for the purpose of improving the coating film hardness, inorganic fine particles (particle size 5 to 100 nm) such as silica gel can be added in an addition amount (0.1 to 50% by mass) within a range not impairing transparency.

The cured product of the present invention is obtained by curing the energy beam curable resin composition. Examples of active energy rays include electron beams, ultraviolet rays, and gamma rays. Irradiation conditions are determined according to the composition of the active energy ray-curable coating material used to obtain the protective layer, but in the case of ultraviolet irradiation, irradiation is usually performed so that the integrated light amount is 10 to 5,000 mj / cm ^2. It is preferable to irradiate such that the integrated light quantity is 50 to 1,000 mj / cm ² . Moreover, when irradiating an electron beam, it is preferable that it is a 1-5 Mrad irradiation amount. Among these, ultraviolet curing is preferable because it is easy to handle.

  The film of the present invention has a cured layer formed by curing the active energy ray-curable resin composition on a film-like substrate.

  Examples of the film-like substrate include films made from polyethylene, polypropylene, triacetyl cellulose, polyethylene terephthalate, vinyl chloride, polycarbonate, and the like.

  Examples of the coating means for forming the layer of the active energy ray-curable resin composition on the film substrate include coating methods such as gravure coating, roll coating, spray coating, lip coating, and comma coating And printing methods such as gravure printing and screen printing. At the time of coating, it is preferable that the thickness of the cured protective layer is 0.1 to 400 μm, and it is more preferable that the thickness is 1 to 50 μm.

  When the active energy ray-curable resin composition containing an organic solvent is used, the organic solvent is usually removed after forming the active energy ray-curable resin composition layer on the substrate film. As a method for removing the organic solvent, it may be left as it is to evaporate, or may be dried using a dryer or the like, but the temperature at the time of removing the organic solvent is usually from 70 to The drying time at 130 ° C. is preferably in the range of 10 seconds to 10 minutes.

  After forming the active energy ray-curable coating layer by the above method or the like, the coating layer is irradiated with active energy rays to obtain the film of the present invention.

  Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples. In the following, all parts and% are based on mass unless otherwise specified.

  In Examples of the present invention, the weight average molecular weight (Mw) and the number average molecular weight (Mn) were measured using gel permeation chromatography (GPC) under the following conditions.

Measuring device: HLC-8220GPC manufactured by Tosoh Corporation
Column: TSK-GUARDCOLUMN SuperHZ-L manufactured by Tosoh Corporation
+ Tosoh Corporation TSK-GEL SuperHZM-M x 4
Detector: RI (differential refractometer)
Data processing: Multi-station GPC-8020 model II manufactured by Tosoh Corporation
Measurement conditions: Column temperature 40 ° C
Solvent tetrahydrofuran
Flow rate: 0.35 ml / min Standard: Monodispersed polystyrene sample: 0.2 wt% tetrahydrofuran solution in terms of resin solids filtered through a microfilter (100 μl)

Synthesis Example 1 [Synthesis of Urethane Acrylate (A)]
4,000 g (2 mol) of polypropylene glycol having a weight average molecular weight (Mw) of 2,000 and 182 g (1 mol) of 1,2-bis (2hydroxyethylthio) ethane were charged into a flask, and tin octoate as a catalyst. (II) and zinc octoate (II) are each 200 ppm, dibutylhydroxytoluene is 3,000 ppm, methoquinone is 300 ppm as a polymerization inhibitor, and normal butyl acetate is added as a solvent in an amount of 80% solid content and mixed well. The temperature in the system was adjusted to 50 ° C. Thereafter, 696 g ( 4 mol) of toluene diisocyanate was added in three portions while paying attention to heat generation, and the mixture was reacted at 80 ° C. for 1 hour. Furthermore, 260 g (2 mol) of hydroxypropyl acrylate was added, and the reaction was performed at 80 ° C. while blowing air, until the isocyanate group completely disappeared to obtain urethane acrylate (A1) having a weight average molecular weight (Mw) of 24,000.

Synthesis examples 2 to 7 (same as above)
Urethane acrylates (A2) to (A7) were obtained in the same manner as in Synthesis Example 1 except that the synthesis was performed using the raw materials and blending amounts shown in Table 1. The respective weight average molecular weight (Mw) values are shown in Table 1.

Footnotes in Table 1 Polyalkylene glycol 1: Polypropylene glycol having a weight average molecular weight of 2,000 Polyalkylene glycol 2: Polypropylene glycol having a weight average molecular weight of 1,000 Polyalkylene glycol 3: Polypropylene glycol having a weight average molecular weight of 4,000 Polyalkylene glycol 4: Polypropylene glycol having a weight average molecular weight of 700

Synthesis examples 8 to 10 [Synthesis of comparative urethane (meth) acrylate (a)]
Comparative comparative urethane acrylates (a1) to (a3) were obtained in the same manner as in Synthesis Example 1 except that the synthesis was performed using the raw materials and blending amounts shown in Table 2. The respective values of weight average molecular weight (Mw) and number average molecular weight (Mn) are shown in Table 2.

Footnotes in Table 2 Polyalkylene glycol 5: Polypropylene glycol having a weight average molecular weight of 400 Polyalkylene glycol 6: Polypropylene glycol having a weight average molecular weight of 8,000 Polyalkylene glycol 7: Polypropylene glycol having a weight average molecular weight of 2,000

Synthesis Example 11 [Synthesis of polyfunctional (meth) acrylate (B)]
A flask was charged with 535.5 g of a mixture of pentaerythritol triacrylate and pentaerythritol tetraacrylate (weight ratio 60/40). Add stannous octoate (II) and zinc octoate (II) as catalysts, dibutylhydroxytoluene (3,000 ppm) as an antioxidant, and methoquinone (300 ppm) as a polymerization inhibitor, and add normal butyl acetate as a solid. The mixture was mixed so that the content became 80%, and the temperature in the system was adjusted to 50 ° C.

  While blowing air into the system, 84 g of hexamethylene diisocyanate was added in three portions. The temperature in the system was raised to 80 ° C. and reacted at 80 ° C. until the isocyanate groups in the system disappeared completely to obtain urethane acrylate (B1). According to GPC analysis, the weight average molecular weight of urethane acrylate (B1) was 1,400. The acryloyl equivalent was 109 g / mol.

Example 1
Urethane acrylate (A1) 3 g, urethane acrylate (B1) 48.5 g, mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate (weight ratio 40/60) 48.5 g, 1-hydroxycyclohexyl phenyl ketone 4 g, butyl acetate 104 g was mixed to obtain an active energy ray-curable composition (1) having a solid content of 50% by mass. Using the composition (1), a hard coat layer was formed on the film under the following conditions, and the difficulty of conspicuous adhesion of the fingerprint trace and the ease of wiping off the fingerprint trace was evaluated according to the following criteria. The conspicuousness of the attached fingerprint trace and the ease of wiping off the attached fingerprint trace were evaluated in each of the initial stage in which the hard coat layer was formed and the stage after 20 times of attaching and removing the fingerprint trace. The removal of the attached fingerprint trace was performed by an evaluation method for ease of wiping off the fingerprint trace described later. The acryloyl equivalent of 48.5 g of urethane acrylate (B1) and 48.5 g of a mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate (weight ratio 40/60) was 104 g / mol.

<Method for forming hard coat layer>
Composition (1) A PET film (125 μm) was coated using a bar coater so that the dry film thickness was 5 μm. After the solvent was dried at 70 ° C. for 5 minutes, ultraviolet rays were irradiated with a high-pressure mercury lamp (80 W / cm) so that the irradiation amount was 500 mJ / cm ² to obtain a hard coat layer. The ultraviolet irradiation was performed in an air atmosphere or a nitrogen atmosphere.

<Evaluation of the difficulty of conspicuous fingerprint marks (quantitative evaluation)>
The inconspicuousness of fingerprint marks was quantitatively evaluated by the viewing angle. The viewing angle refers to an angle at which the fingerprint trace starts to be confirmed by gradually lowering the viewing angle with respect to the fingerprint trace attached to the hard coat layer from 90 degrees. The smaller the viewing angle, the better the fingerprint marks are less noticeable.

<Evaluation of ease of wiping off fingerprint marks (quantitative evaluation)>
The ease of wiping off the fingerprint marks was evaluated by the number of times of wiping when the fingerprint marks were removed from the hard coat layer. Specifically, the tissue paper was reciprocated at 1 Kg (per 5.7 square centimeters) on the fingerprint trace adhered to the hard coat layer, and quantitative evaluation was performed by the number of reciprocations until the adhered fingerprint trace was completely invisible. The smaller the number of reciprocations, the better the wiping of fingerprint marks.

<Evaluation of coating film hardness>
Pencil hardness was measured according to JIS K5600-5-4. The hardness was measured five times for each hardness, and the hardness that the cured coating film had was not damaged more than four times.

Examples 2-9 and Comparative Examples 1-3
Active energy ray-curable resin compositions 2 to 9 and comparative active energy ray-curable resin compositions 1 'to 3' were used in the same manner as in Example 1 except that the formulations shown in Tables 3 and 4 were used. Prepared. Evaluation similar to Example 1 was performed, and the results are shown in Tables 5-7.

Footnotes in Tables 3 and 4 Multifunctional acrylate (B2): Mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate (weight ratio 40/60)
The acryloyl group equivalent of the mixture of polyfunctional acrylate (B1) and polyfunctional acrylate (B2) is 104 g / mol.
Photoinitiator: 1-hydroxycyclohexyl phenyl ketone Diluent: normal butyl acetate

Claims (9)

A polyalkylene glycol (a1) having a weight average molecular weight (Mw) in the range of 500 to 5,000, a diol (a2) having an alkylene thioether structure in the molecular structure, a diisocyanate (a3) having a molecular weight of 500 or less, The urethane having a weight average molecular weight (Mw) in the range of 10,000 to 100,000 obtained by reacting (meth) acrylate (a4) having one hydroxyl group in the molecular structure as an essential raw material component ( It contains a (meth) acrylate (A) and a polyfunctional (meth) acrylate (B), and the mass ratio of the urethane (meth) acrylate (A) and the polyfunctional (meth) acrylate (B) [(A) / (B)] is in the range of 0.1 / 99.9 to 15/85, and the molecular weight is 60 as the polyfunctional (meth) acrylate (B). A is 4 or more functional groups of less than (meth) acrylate (b1) and oligomeric polyfunctional molecular weight in the range of 600～3,000 (meth) acrylate (b2) in combination with, these mass ratio [(b1) / (b2)] is an active energy ray curable resin composition, wherein the range der Rukoto of 1/2 to 2/1.   The active energy ray-curable resin composition according to claim 1, wherein the polyalkylene glycol (a1) is polypropylene glycol. The active energy ray-curable resin composition according to claim 1, wherein the diol (a2) having an alkylene thioether structure in the molecular structure is a compound represented by the following general formula (1) or general formula (2).

(In the formula, R1 and R2 are each an alkyl group having 1 to 4 carbon atoms or a halogenated alkyl group.)

(In the formula, l, m, and n are each 0 or 1, and R1, R2, R3, R4, R5, and R6 are each an alkyl group or halogenated alkyl group having 1 to 4 carbon atoms. Is a sulfur atom or an oxygen atom, and more than half of X contained in the compound is a sulfur atom.)   The diol (a2) having the alkylene thioether structure in the molecular structure is 2,2′-thiobis (1-propanol), 1,2-bis (2-hydroxyethylthio) ethane, 2- [2- [2- (2-hydroxyethylthio) propylthio] -1-methylethylthio] ethanol, 1- (2- [2- (2-hydroxypropylsulfanyl) propylsulfanyl] 1-methyl-ethylsulfanyl) propan-2-ol The active energy ray-curable resin composition according to claim 1, which is one or more compounds selected from the group.   The molar ratio [(a1) / (a2)] of the content of the polyalkylene glycol (a1) in the raw material of the urethane (meth) acrylate (A) and the diol (a2) having an alkylene thioether structure in the molecular structure is 2. The active energy ray-curable resin composition according to claim 1, which is in a range of 1 / 0.2 to 1/5.   The active energy ray curable type according to claim 1, wherein the (meth) acrylate (a4) having one hydroxyl group in the molecular structure is a monohydroxy mono (meth) acrylate having one methacryloyl group in the molecular structure. Resin composition. Oligomeric multifunctional (meth) acrylate (b2) polyfunctional urethane (meth) radiation-curable resin composition of claim 1 wherein the acrylate wherein the molecular weight is in the range of 600～3,000. Cured product, characterized in that formed by curing an active energy ray curable resin composition according to any one of claims 1-7. A film having a cured layer formed by curing the active energy ray-curable resin composition according to any one of claims 1 to 7 on a film-like substrate.