JP2015086372A - Coating composition nd hard coat film using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coating composition for a hard coat film and a hard coat film good in weather resistance while maintaining excellent excoriation resistance and substrate adhesiveness and further excellent in substrate adhesiveness after storage under high temperature and high humidity environment.SOLUTION: A hard coat film is manufactured from a coating composition containing (A) energy ray-curable (meth)acrylate monomer having a weight average molecular weight of 250 to 1000, the number of energy ray-curable functional groups of 2 to 9, and the number of hydroxyl groups of 1 or less, (B) energy ray-curable functional group-containing ultraviolet absorber and (C) an energy ray-curable oligomer having the weight average molecular weight of 1500 to 20000.

Description

  The present invention relates to a coating composition and a hard coat film using the same.

  Conventionally, in order to prevent the surfaces of glass and resin molded bodies from being damaged, a hard coating film is provided on these surfaces by applying a coating material made of energy ray curable resin or the like, or a hard coating layer is formed on the resin film. The hard coat film provided with is attached to the glass or resin molded body.

  The above hard coat film and hard coat film are widely used for display screens such as displays, touch panels, and mobile phones. Especially, mobile products such as mobile phones and smartphones have an opportunity to be used outdoors. It is increasing. As such a hard coat film for outdoor use, a film that does not yellow even when exposed to ultraviolet rays for a long time is required. For this reason, it has been proposed to add an ultraviolet absorber or a light stabilizer to the hard coat layer for the purpose of imparting weather resistance (Patent Document 1).

JP-A-9-157315

  However, in the hard coat film proposed in Patent Document 1, there is a problem that curing inhibition occurs by adding an ultraviolet absorber or a light stabilizer, and the coating film hardness, scratch resistance, and substrate adhesion decrease. Has occurred. This problem is remarkable when a large amount of an ultraviolet absorber or a light stabilizer is added to cope with a higher level of weather resistance.

  In addition, in order to reduce production costs, the production base of each component part and the assembly base of the mobile product are often different in the above mobile products. The production and transportation of various component parts are under high temperature and high humidity, and the mobile products are stored for a long time. In consideration of the properties, the hard coat layer must not deteriorate (scratch resistance) in a high temperature and high humidity environment. Furthermore, even in such an environment, it is necessary to have excellent substrate adhesion that does not cause peeling between the hard coat layer and the transparent support.

  Accordingly, an object of the present invention is to provide a hard coat film coating composition and a hard coat film that improve the above-mentioned drawbacks and have good weather resistance while maintaining excellent scratch resistance and substrate adhesion. . Furthermore, an object of the present invention is to provide a hard coat film coating composition and a hard coat film that are excellent in substrate adhesion even after storage in a high temperature and high humidity environment.

As a result of intensive studies to solve the above problems, the present inventors have determined that an energy ray curable (type) (meth) acrylate monomer having a specific molecular weight, a specific number of energy ray curable functional groups and a number of hydroxyl groups, The present inventors have found that the above problems can be solved by using a coating composition containing an energy ray-curable (meth) acrylate oligomer having a molecular weight and a specific ultraviolet absorber, and have completed the present invention.
(Meth) acrylate refers to acrylate or methacrylate.

  That is, according to this invention, the coating composition and hard coat film of the structure shown below are provided.

  The coating composition of the present invention comprises (A) an energy ray curable (meth) acrylate having a weight average molecular weight of 250 to 1,000, an energy ray curable functional group number of 2 to 9, and a hydroxyl group number of 1 or less. It contains a monomer, (B) an energy ray-curable functional group-containing ultraviolet absorber, and (C) an energy ray-curable oligomer having a weight average molecular weight of 1500 or more and 20000 or less.

  The coating composition of the present invention comprises (E1) a photopolymerization initiator having a maximum absorbance of 0.1 or more in a wavelength range of 340 nm to 400 nm of a 0.01 mass% methanol solution or acetonitrile solution, and (E2) It is preferable to further contain a photopolymerization initiator having a maximum absorbance of 0.1 or more in a wavelength range of 220 nm to 280 nm of a 0.001 mass% methanol solution or acetonitrile solution.

  In the coating composition of the present invention, the mass ratio of the component (A) to the component (C) (component (A): component (C)) is preferably 3:97 to 50:50.

  Further, in the coating composition of the present invention, the component (B) is preferably an ultraviolet absorber having a maximum absorbance of 0.6 or more in a wavelength range of 280 nm to 370 nm of a 0.0619 mmol / l dichloromethane solution.

  The hard coat film of the present invention has a hard coat layer obtained from the above coating composition on at least one surface of a transparent support.

  In the hard coat film of the present invention, the thickness of the hard coat layer is preferably 0.5 μm or more and 20 μm or less.

  In the hard coat film of the present invention, the substrate adhesion between the hard coat layer and the transparent support is preferably 90/100 or more based on JIS K5400.

  The hard coat film of the present invention has a temperature of 60 ° C. and a relative humidity of 90% R.D. H. It is preferable that the substrate adhesion between the hard coat layer and the transparent support after being subjected to the moisture resistance test to be left in the above environment for 550 hours is 90/100 or more based on JIS K5400.

  Further, the hard coat film of the present invention preferably has a yellowing degree (Δb) of less than 1 after 12 cycles of the weather resistance test specified in ASTM G-154.

  According to the present invention, it is possible to provide a hard coat film coating composition and a hard coat film which are excellent in scratch resistance, weather resistance and substrate adhesion.

Hereinafter, embodiments of the present invention will be described in detail.
(1) Coating composition The coating composition of the present invention comprises (A) an energy ray having a weight average molecular weight of 250 to 1,000, an energy ray-curable functional group number of 2 to 9, and a hydroxyl group number of 1 or less. It contains a curable (meth) acrylate monomer, (B) an energy ray-curable functional group-containing ultraviolet absorber, and (C) an energy ray-curable oligomer having a weight average molecular weight of 1500 to 20000.
Each component will be described below.

(A) Energy ray curable (meth) acrylate monomer The coating composition of the present invention has a weight average molecular weight of 250 or more and 1000 or less, an energy ray curable functional group number of 2 or more and 9 or less, and a hydroxyl group number of 1. It is essential to use the following energy ray-curable (meth) acrylate monomer. By using such a monomer, hardness, scratch resistance, and substrate adhesion can be improved. In particular, the substrate adhesion in a high temperature and high humidity environment can be effectively improved.

  By setting the weight average molecular weight of the (meth) acrylate monomer to 250 or more, it is possible to provide film properties when the hard coat layer is formed. For this reason, while being able to improve base-material adhesiveness, the fall of abrasion resistance can be suppressed. Moreover, volatilization of the unreacted monomer due to heating can be prevented in the manufacturing process of the hard coat layer. On the other hand, by setting the weight average molecular weight to 1000 or less, the molecular weight is not too large. Therefore, as will be described later, the component (A) is easily arranged in the gap between the molecules of the component (B) and the component (C). Therefore, the crosslinking efficiency is improved, the adhesion of the substrate is improved, and the deterioration of the scratch resistance due to the addition of the ultraviolet absorber can be suppressed. Moreover, when it is set as the coating liquid for hard-coat layers, it can prevent becoming high viscosity. In addition, the weight average molecular weight of a (meth) acrylate monomer can be confirmed by gel permeation chromatography (GPC).

By making the number of hydroxyl groups of the (meth) acrylate monomer 1 or less, it is possible to suppress a decrease in substrate adhesion in a high temperature and high humidity environment. In the present invention, as described above, since the energy ray-curable monomer having a weight average molecular weight of 250 or more and 1000 or less is used, sufficient substrate adhesion can be obtained without having a hydroxyl group. In the case where the (meth) acrylate monomer has one hydroxyl group, the adhesiveness is improved by the reaction between the above-mentioned transparent support, that is, the acidic functional group present on the surface of the glass or resin substrate and the hydroxyl group. Therefore, the substrate adhesion can be further improved.
Use of a monomer having 2 or more hydroxyl groups is advantageous in that the adhesion is improved by reaction with the functional group on the surface of the transparent support. However, since unreacted hydroxyl groups remain in the hard coat layer, the adhesiveness of the substrate is lowered under the influence of the remaining hydroxyl groups in a high temperature and high humidity environment. In the present invention, since the number of hydroxyl groups in the (meth) acrylate monomer is 1 or less, there is almost no unreacted hydroxyl group after the curing reaction, so that the substrate adhesion is reduced due to the remaining hydroxyl group even in a high temperature and high humidity environment. Can be suppressed.

Further, by setting the number of energy ray-curable functional groups of the (meth) acrylate monomer to 2 or more and 9 or less, it is possible to obtain a hard coat film having high hardness and excellent scratch resistance and substrate adhesion. By using a (meth) acrylate monomer having two or more energy ray-curable functional groups, the cross-linking reaction with the component (B) and the component (C) proceeds more effectively. Further, it is possible to suppress a decrease in scratch resistance due to the addition of the ultraviolet absorber. When the number of energy ray-curable functional groups of the (meth) acrylate monomer is 1 or less, it is difficult to obtain a hard coat film having high hardness and excellent scratch resistance. In addition, when such a (meth) acrylate monomer is used, the crosslinking reaction does not proceed sufficiently. Therefore, the obtained hard coat film is easily deteriorated by ultraviolet light, and it is difficult to obtain excellent weather resistance. Furthermore, since the crosslinking reaction does not proceed sufficiently, it is difficult to obtain excellent substrate adhesion.
On the other hand, when the (meth) acrylate monomer having 9 or less energy ray-curable functional groups is used, the (A) component is easily arranged in the gap between the molecules of the (B) component and the (C) component, and the crosslinking efficiency is also improved. In addition, the substrate adhesion is improved, and the deterioration of the scratch resistance due to the addition of the ultraviolet absorber can be suppressed. When a (meth) acrylate monomer having an energy ray-curable functional group number exceeding 9 is used, an excessive crosslinking reaction between the components (A) tends to proceed, so the component (A) is composed of the components (B) and (C). It is difficult to obtain a hard coat film having excellent scratch resistance and substrate adhesion because it is difficult to be disposed in the gap between molecules and the crosslinking density is difficult to increase.

  Examples of the (A) (meth) acrylate monomer as described above include dipentaerythritol hexa (meth) acrylate, trimethylolpropane (meth) acrylate, pentaerythritol tri (meth) acrylate, ethylene glycol di (meth) acrylate, Ethylene glycol divinyl ether, tetraethylene glycol (meth) acrylate, tripropylene glycol (meth) acrylate, 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di ( (Meth) acrylate, trimethylolpropane trioxyethyl (meth) acrylate, tris (2-hydroxyethyl) isocyanurate tri (meth) acrylate, dipentaerythritol poly Examples thereof include acrylate, dipentaerythritol hexaacrylate, tricyclodecane dimethanol diacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, trimethylolpropane triacrylate, ditrimethylolpropane tetraacrylate, and the like. Of these, dipentaerythritol hexaacrylate, pentaerythritol triacrylate, and pentaerythritol tetraacrylate are preferred because of good adhesion to the transparent support and high reactivity.

(B) Ultraviolet absorber The coating composition of this invention contains an energy ray-curable functional group containing ultraviolet absorber. Usually, in order to obtain the weather resistance of the hard coat layer and the hard coat film, an ultraviolet absorber is added to the coating composition. In this invention, since it has an energy-beam curable functional group containing ultraviolet absorber as a ultraviolet absorber, the crosslinking reaction between (A) component mentioned above and (C) component mentioned later progresses effectively. Therefore, the crosslink density is improved, and the deterioration of the scratch resistance due to the addition of the ultraviolet absorber can be suppressed. Moreover, by incorporating the ultraviolet absorber into the crosslinked structure by the crosslinking reaction, bleeding out from the hard coat layer is suppressed, and a decrease in substrate adhesion can be suppressed. In particular, when the coating composition of the present invention using an ultraviolet absorber having an energy ray-curable functional group is used in a high-temperature and high-humidity environment, the effect of suppressing the decrease in substrate adhesion is noticeable.

  As such energy ray-curable functional group-containing ultraviolet absorbers, benzotriazole-based and triazine-based ultraviolet absorbers can be used. Examples of the benzotriazole ultraviolet absorber (compound) include 2- (2′-hydroxy-5′-methylphenyl) benzotriazole, 2- (2′-hydroxy-5′-t-butylphenyl) benzotriazole, 2- (2′-hydroxy-3′-t-butyl-5′-methylphenyl) -5-chlorobenzotriazole, 2- (2′-hydroxy-3 ′, 5′-di-t-butylphenyl)- 5-chlorobenzotriazole, 2- (2′-hydroxy-3′-t-butyl-5 ′-(2- (octyloxycarbonyl) ethyl) phenyl) -5-chlorobenzotriazole, 2- (2′-hydroxy) -3'-dodecyl-5'-methylphenyl) -5-chlorobenzotriazole, 2- (2'-hydroxy-3 ', 5'-di-t-amylpheny ) Benzotriazole, 2- (2′-hydroxy-5′-t-octylphenyl) benzotriazole, 2- (2′-hydroxy-3 ′, 5′-di- (dimethylbenzyl) phenyl) benzotriazole, 2- (2′-hydroxy-4′-octyloxyphenyl) benzotriazole, 2,2′-methylene-bis (2- (2′-hydroxy-5′-t-octylphenyl) benzotriazole) 2- (2′- Examples include hydroxy-3 ′-(3,4,5,6-tetrahydrophthalimidylmethyl) -5′-methylbenzyl) phenyl) benzotriazole and the like and a compound having a (meth) acryloyl group. Further, as triazine-based ultraviolet absorbers (compounds), 2- (4-hexyloxy-2-hydroxyphenyl) -4,6-diphenyl-1,3,5-triazine, 2- (4-octyloxy-2-hydroxy) Phenyl) -4,6-di (2,5-dimethylphenyl) -1,3,5-triazine, 2- (4-butoxy-2-hydroxyphenyl) -4,6-di (4-butoxyphenyl)- 1,3,5-triazine, 2- (4-butoxy-2-hydroxyphenyl) -4,6-di (2,4-dibutoxyphenyl) -1,3,5-triazine, 2- (4- ( 3- (2-ethylhexyloxy) -2-hydroxypropoxy) -2-hydroxyphenyl) -4,6-di (2,4-dimethylphenyl) -1,3,5-triazine, 2- (4- ( 3-dodecyloxy 2-hydroxypropoxy) -2-hydroxyphenyl) -4,6-di (2,4-dimethylphenyl) -1,3,5-triazine, 2,4-di (4-butoxy-2-hydroxyphenyl)- 6- (4-Butoxyphenyl) -1,3,5-triazine, 2,4-di (4-butoxy-2-hydroxyphenyl) -6- (2,4-dibutoxyphenyl) -1,3,5 -The compound etc. which have triazine etc. and a (meth) acryloyl group can be mention | raise | lifted. Among these, an ultraviolet absorber having a maximum absorbance of 0.6 or more in a wavelength range of 280 nm to 370 nm of a 0.0619 mmol / l solution dissolved in dichloromethane is preferable in terms of excellent ultraviolet absorption performance. Examples of such ultraviolet absorbers include 2- (2′-hydroxy-5′-methylphenyl) benzotriazole and a compound having a (meth) acryloyl group, and 2- (4-hexyloxy-2-hydroxyphenyl) -4. , 6-Diphenyl-1,3,5-triazine and a compound having a (meth) acryloyl group are preferably used. The energy ray-curable functional group-containing ultraviolet absorber as described above may be used alone or in combination of two or more.

  The addition amount of the component (B) varies depending on the desired weather resistance performance and the thickness of the hard coat layer. It is preferable to set it as a mass part or more, Furthermore, it is 2.5 mass part or more, Furthermore, you may be 3 mass part or more. The upper limit is preferably 12 parts by mass or less, more preferably 10 parts by mass or less, and further preferably 8 parts by mass or less. More excellent weather resistance can be obtained by setting the lower limit to 2 parts by mass or more, and excellent coating film hardness, scratch resistance and substrate adhesion can be maintained by setting the upper limit to 12 parts by mass or less. Can do.

(C) (Meth) acrylate oligomer (energy ray curable oligomer)
The coating composition of the present invention contains an energy ray-curable oligomer having a weight average molecular weight of 1500 or more and 20000 or less. From the coating composition containing the oligomer, a hard coat layer and a hard coat film having good coating film hardness and scratch resistance can be obtained.

By setting the weight average molecular weight of the energy ray-curable oligomer to 1500 or more, a hard coat film and a hard coat film having good flexibility and substrate adhesion can be obtained. Moreover, the hard coat film | membrane or hard coat film with favorable coating-film hardness and abrasion resistance is obtained by making the weight average molecular weight of an energy-beam curable oligomer into 20000 or less, Preferably it is 10,000 or less.
Here, the weight average molecular weight of the energy ray curable oligomer is preferably 1.5 to 20 times the weight average molecular weight of the energy ray curable monomer ((meth) acrylate monomer). By making the ratio of the weight average molecular weight of the energy ray curable oligomer and the weight average molecular weight of the energy ray curable monomer within the above range, it becomes easier for the energy ray curable monomer to enter the gap between the energy ray curable oligomers. When the cross-linking reaction proceeds in a dense state and the cross-linking density is increased, the decrease in hardness and scratch resistance due to the addition of the ultraviolet absorber can be effectively suppressed. Here, the weight average molecular weights of the energy ray curable monomer and the energy ray curable oligomer are values obtained from a gel permeation chromatograph (GPC).

  As the energy ray curable oligomer, a (meth) acrylic oligomer having two or more (meth) acryloyl groups in one molecule and having a three-dimensional network structure by crosslinking and curing is particularly preferably used. Examples of such (meth) acrylic oligomers include urethane (meth) acrylate, polyester (meth) acrylate, epoxy (meth) acrylate, melamine (meth) acrylate, polyfluoroalkyl acrylate, and silicone acrylate.

  The energy ray curable oligomer is preferably a polyfunctional urethane (meth) acrylate oligomer having an energy ray curable functional group number of 10 or more and 20 or less. By using such a polyfunctional urethane (meth) acrylate oligomer, a high crosslinking density can be achieved, so that the coating film hardness and the scratch resistance can be further improved. By setting the number of energy ray-curable functional groups of the polyfunctional urethane (meth) acrylate oligomer to 10 or more, the crosslinking density can be sufficiently increased and the hardness can be increased. As a result, the scratch resistance can be greatly improved. Further, by setting the number of energy ray-curable functional groups to 20 or less, preferably 16 or less, it is possible to suppress steric hindrance due to high cross-linking density and to prevent a decrease in hardness due to inhibition of curing.

  The content ratio of the component (A) (energy beam curable monomer) and the component (C) (energy beam curable oligomer) in the coating composition of the present invention is preferably 3:97 to 50:50 in mass ratio. Furthermore, it is preferable to set it as 5: 95-30: 70. By making the mass ratio of the component (A) and the component (C) in the coating composition within the above range, the substrate adhesion between the hard coat layer and the transparent support, particularly the substrate adhesion after the moisture resistance test, is further improved. It can be good.

(D) Light stabilizer It is preferable that the coating composition of this invention contains a hindered amine light stabilizer as (D) light stabilizer. By adding a hindered amine light stabilizer to the hard coat layer, radicals generated by ultraviolet rays can be efficiently captured, so that the weather resistance can be further improved. (D) Examples of the light stabilizer include 4-pezoyloxy-2,2,6,6-tetramethylpiperidine, 4-hexanoyloxy-2,2,6,6-tetramethylpiperidine, 4-octanoyloxy. -2,2,6,6-tetramethylpiperidine, 4-stearoyloxy-2,2,6,6-tetramethylpiperidine, succinic acid-bis (2,2,6,6-tetramethylpiperidine), sabasinic acid -Bis (2,2,6,6-tetramethylpiperidine), sabacic acid-bis (1,2,2,6,6-pentamethyl-4-piperidine), 8-acetyl-3-dodecyl-7,7, 9,9-tetramethyl-1,3,8-triazaspiro [4,5] decane-2,4-dione, N-methyl-3-dodecyl-1- (2,2,6,6-tetramethyl-4 -Piperidini ) Pyrrolidine-2,5-dione, N-acetyl-3-dodecyl-1- (2,2,6,6-tetramethyl-4-piperidinyl) pyrrolidine-2,5-dione, phthalate-bis (1, 2,2,6,6-pentamethyl-4-piperidine), trimesic acid-tris (2,2,6,6-tetramethyl-4-piperidyl) and the like. These may be used alone or in combination of two or more.

  The amount of component (D) added is preferably 0.05 parts by mass or more, more preferably 0.5 parts by mass or more as the lower limit with respect to the total of 100 parts by mass of component (A) and component (C) described above. Is preferably 5 parts by mass or less, and more preferably 3 parts by mass or less. When the amount of component (D) is 0.05 parts by mass or more, good weather resistance can be obtained, and when it is 5 parts by mass or less, good scratch resistance can be maintained.

(E) Photopolymerization initiator The (E) photopolymerization initiator used in the coating composition of the present invention is (E1) in a wavelength range of 340 nm to 400 nm of a 0.01% by mass solution dissolved in methanol or acetonitrile. A photopolymerization initiator having a maximum absorbance of 0.1 or more and (E2) a maximum absorbance of 0.1 or more in a wavelength range of 220 nm to 280 nm of a 0.001 mass% solution dissolved in methanol or acetonitrile. It is preferable to contain one or more photopolymerization initiators. When forming a cured coating film by ultraviolet irradiation, by using these two types of photopolymerization initiators, the deterioration of the adhesion of the substrate in a high-temperature and high-humidity environment is greatly suppressed compared to the case where each is used alone. be able to.

[(E1) component]
The component (E1) used in the present invention is a photopolymerization initiator having a maximum absorbance of 0.1 or more in a wavelength range of 340 nm to 400 nm of a 0.01% by mass solution dissolved in methanol or acetonitrile. . For example, 1-hydroxy-cyclohexyl-phenyl-ketone, 2,2-dimethoxy-1,2-diphenylethane-1-one, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, 2-benzyl- 2-Dimethylamino-1- (4-morpholinophenyl) -butanone-1, bis (η5-2,4-cyclopentadien-1-yl) -bis (2,6-difluoro-3- (1H-pyrrole) 1-yl) -phenyl) titanium, 2-dimethylamino-2- (4-methylbenzyl) -1- (4-morpholinophenyl) butanone, diphenyl (2,4,6-trimethylbenzoyl) phosphine oxide and the like. be able to. The said component may be used individually by 1 type, and may use 2 or more types together.

  A commercially available product can be used as the component (E1), and examples thereof include Irgacure 651, 907, 819, 369, 379, 1800, 784, Darocur 4265, Lucillin TPO (above, manufactured by BASF).

[(E2) component]
The component (E2) used in the present invention is a photopolymerization initiator having a maximum absorbance of 0.1 or more in a wavelength range of 220 nm to 280 nm of a 0.001 mass% solution dissolved in methanol or acetonitrile. . For example, 2-methyl-1 [4- (methylthio) phenyl] -2-morpholinopropan-1-one 2,2-dimethoxy-1,2-diphenylethane-1-one, 1- [4- (2 -Hydroxyethoxy) -phenyl] -2-hydroxy-2-methyl-1-propan-1-one, 2-hydroxy-2-methyl-1-phenyl-propan-1-one, methyl oxophenylacetate, oligo [2 -Hydroxy-2-methyl- [1- (4-methylvinyl) phenyl] propanone and the like can be mentioned. The said component may be used individually by 1 type, and may use 2 or more types together.

  As the component (E2), a commercially available product can be used. (Above, manufactured by Lamberti).

From the viewpoint of suppressing a decrease in substrate adhesion in a high-temperature and high-humidity environment, the addition amount of the photopolymerization initiator as the component (E1) is made smaller than the addition amount of the photopolymerization initiator as the component (E2). It is preferable. Specifically, the addition ratio of the (E1) component and the (E2) component is preferably in the range of 3:97 to 45:55 by mass ratio. In addition, when it contains several (E1) component and / or (E2) component, it is preferable that ratio of the total mass of each of (E1) component and (E2) component becomes the said range.
Some photopolymerization initiators have a photopolymerization start wavelength region of (E1) and (E2) components. Hereinafter, the maximum value of the absorbance in the wavelength range of 340 nm to 400 nm of such a photopolymerization initiator, that is, a 0.01 mass% methanol solution or acetonitrile solution is 0.1 or more and 0.001 mass%. A photopolymerization initiator having a maximum absorbance in a wavelength range of 220 nm to 280 nm of a methanol solution or acetonitrile solution of 0.1 or more is referred to as (E1,2) component or (E1,2) photopolymerization initiator. However, even if one type of the photopolymerization initiator (E1, 2) is used, the same effect as when two types of photopolymerization initiator (E1) and (E2) are used together cannot be obtained. . On the other hand, when two or more types of photopolymerization initiators (E1, 2) are used, the same effect as when the photopolymerization initiator (E1) and the photopolymerization initiator (E2) are used in combination is recognized. . Moreover, the same effect is acquired also when the photoinitiator of (E1) or the photoinitiator of (E2) is further added to the photoinitiator of (E1,2). In this case, in particular, a more excellent effect can be obtained by adding the component (E2). In production, the kind and amount of the polymerization initiator as an additive are preferably as small as possible. However, within the range that does not affect other physical properties of the hard coat layer or hard coat film, the photopolymerization initiator of (E1, 2), the photopolymerization initiator of (E1) and the photopolymerization of (E2) An initiator can also be added.
In the present application, “containing (E1) component and (E2) component” includes a constitution containing two or more types of photopolymerization initiators (E1,2) and a photopolymerization initiator (E1,2) ( The structure containing the photoinitiator of E1) and / or the photoinitiator of (E2) shall also be included.
Thus, by containing two kinds of photopolymerization initiators, scratch resistance which has been a problem of hard coat films and hard coat films obtained from conventional energy ray curable coating compositions having ultraviolet absorption performance And base material adhesiveness can be improved. In particular, by using the two types of photopolymerization initiators, it is possible to obtain a coating film in which the substrate adhesion in a high temperature and high humidity environment is significantly improved.

  The content of the component (E) used in the hard coat paint of the present invention is 1 part by mass as the lower limit, and further 3 parts by mass with respect to a total of 100 parts by mass of the component (A) and the component (C). The upper limit is preferably 15 parts by mass or less, and more preferably 12 parts by mass or less. By setting it to 1 part by mass or more, the coating film hardness and the substrate adhesion can be made sufficient, and by setting it to 15 parts by mass or less, inhibition of curing due to recombination of the components (E) is prevented. Thus, the substrate adhesion can be made sufficient.

  Furthermore, the coating composition of the present invention may contain other resins, solvents, photopolymerization initiation aids, leveling agents, antifoaming agents, antioxidants, polymerization inhibitors, crosslinking agents, pigments, antifouling, if necessary. Add additives such as agents, fine particles, lubricants, fluorescent brighteners, antistatic agents, flame retardants, antibacterial agents, antifungal agents, plasticizers, flow regulators, dispersants, release agents, etc. It is also possible to give the function to do.

  Examples of other resins include photo-cationic polymerization such as thermosetting resins, thermoplastic resins, bisphenol epoxy resins, novolac epoxy resins, alicyclic epoxy resins, aliphatic epoxy resins, and other epoxy resins and vinyl ether resins. Resin etc. can be mention | raise | lifted and it can be made to contain in the range which does not inhibit the effect of this invention.

  Solvents include aromatic solvents such as toluene and xylene; ester solvents such as ethyl acetate, butyl acetate, methoxybutyl acetate, and methoxypropyl acetate; ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; diethyl ether, Ether-based solvents such as dibutyl ether, tetrahydrofuran, 1,3-dioxolane, 1,4-dioxane, propylene glycol monomethyl ether acetate, diethylene glycol dimethyl ether, diethylene glycol ethyl methyl ether, and other known organic solvents.

  The type of the organic solvent to be used is determined in consideration of solubility or dispersibility with the component (A), the component (B), the component (C) and the like which are added simultaneously. An organic solvent having a boiling point of 120 ° C. or lower, such as methyl ethyl ketone, methyl isobutyl ketone, and tetrahydrofuran, is preferable in that the solvent hardly remains in the hard coat layer after drying. The said organic solvent may be used individually by 1 type, and may use 2 or more types together. The amount of solvent used is not particularly limited, but it is preferable to adjust the viscosity so that the composition viscosity is suitable for the coating method employed. A preferable usage amount is 5 to 90% by mass of the total composition, more preferably 10 to 85% by mass, and still more preferably 20 to 80% by mass.

  Examples of the photopolymerization initiation assistant include amine compounds, carboxylic acid compounds, polyfunctional thiol compounds, and the like. Examples of the leveling agent include acrylic compounds, high boiling point solvents, fluorine compounds, silicone compounds, and the like. From the viewpoint of finishing the surface into a mirror surface, among the above leveling agents, fluorine compounds and silicone compounds are preferred. Examples of the antioxidant include phenolic compounds. Examples of the polymerization inhibitor include methoquinone, methylhydroquinone, hydroquinone and the like. Examples of the crosslinking agent include isocyanates and melamine compounds. Examples of the fine particles include inorganic fine particles such as silica and calcium carbonate, and organic fine particles such as polymethyl methacrylate and polystyrene. The antifouling agent can include a fluorine compound, a silicon compound, or a mixture thereof, and a fluorine compound is preferable in terms of antifouling performance.

  The coating composition of the present invention includes the components (A), (B), and (C) described above, and, if necessary, other resins, solvents, light stabilizers, photopolymerization initiators, and the like. It can be obtained by adding and mixing agents in any order.

  The coating composition of the present invention thus obtained is a coating composition (hard coat paint) for applying and curing on the surface of glass or resin material. Since the hard coat paint of the present invention contains the component (A), the component (B) and the component (C) described above, when the material to be coated is glass and a resin material, it is cured with the material to be coated. Adhesiveness with the coating film is good. In particular, in a high temperature and high humidity environment, a cured coating film having excellent adhesion (substrate adhesion) between an object to be coated and the cured coating film can be obtained.

(2) Hard coat film and hard coat film The hard coat film of the present invention contains the above-described components (A), (B) and (C), and other resins and additives as necessary. A coating composition (hard coat layer composition) dissolved or dispersed therein is applied to at least one surface of a transparent support, and after drying, it is obtained by curing with energy rays or natural light after drying. be able to. For coating, known methods such as gravure coating, bar coating, knife coating, roll coating, blade coating, die coating, spin coating, flow coating, dip coating, spray coating, and screen printing. Method, brushing, etc. can be used. If the viscosity of the hard coat layer composition is higher than the viscosity suitable for coating, the viscosity may be adjusted using a solvent. Solvents that can be used are as described above.

  As the transparent support, a highly transparent material such as glass or a resin base material can be used. Examples of the resin constituting the resin substrate include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polyethylene, polypropylene, cellophane, diacetyl cellulose, triacetyl cellulose, acetyl cellulose butyrate, polyvinyl chloride, polyvinylidene chloride, Polyvinyl alcohol, ethylene-vinyl acetate copolymer, polystyrene, polycarbonate, polymethylpentene, polysulfone, polyetheretherketone, polyethersulfone, polyetherimide, polyimide, fluorine resin, nylon, acrylic, cycloolefin, norbornene compound, etc. I can give you. Among these, a polyethylene terephthalate film that has been stretched, particularly biaxially stretched, is preferably used because of its excellent mechanical strength and dimensional stability.

  Such a transparent support is used for the purpose of improving the adhesion with the hard coat layer. Surface roughening treatment such as sandblasting or solvent treatment, corona discharge treatment, chromic acid treatment, flame treatment, hot air treatment, plasma Treatment, surface treatment such as ozone / ultraviolet irradiation treatment, formation of an easy-to-undercoat adhesive layer, and the like may be performed. Moreover, before applying the composition for hard-coat layers to the transparent support body, the adhesive layer and the printing and coating for designability provision may be previously provided to the single side | surface or both surfaces. In addition, the transparent support can contain additives that can be used in the above-described coating composition, such as an ultraviolet absorber and a light stabilizer, as long as the effects of the present invention are not impaired.

  The thickness of the transparent support is not particularly limited and may be appropriately selected depending on the application. In the case of glass, 0.3 mm to 5 mm is preferable, and in the case of a resin base material, 25 μm to 500 μm is preferable, and 50 μm to 300 μm is more preferable.

  When the hard coat layer composition contains a solvent, it must be dried after coating. The drying temperature may be determined in consideration of the length of the drying line, the line speed, the coating amount, the residual solvent amount, the type of the transparent support, and the like. If the transparent support is a polyethylene terephthalate film, the general drying temperature is 50 ° C to 150 ° C, preferably 70 ° C to 130 ° C. When there are a plurality of dryers in one line, each dryer may be set to a different temperature and wind speed. In order to obtain a coating film having a good coating appearance, it is preferable that the drying condition on the inlet side is mild.

As a method of curing the hard coat layer composition, it can be cured by irradiation with energy rays or natural light as described above. Considering the stability of the physical property values of the hard coat layer and industrial workability, it is preferable to cure by irradiation with energy rays. Examples of the energy rays include ultraviolet rays and electron beams. In the case of curing with ultraviolet rays, an ultraviolet irradiation device having a xenon lamp, a high-pressure mercury lamp, a metal halide lamp or the like is used as a light source, and the amount of light, the arrangement of the light source, etc. are adjusted as necessary. When using a high pressure mercury lamp preferably cured at a transport speed 5 m / min ～60M / min for one lamp having an energy of ^{80W / cm 2 ~160W / cm 2} . When curing with an electron beam, it is preferable to use an electron beam accelerator having an energy of 100 eV to 500 eV.

  The thickness of the hard coat layer is not particularly limited, and may be appropriately determined depending on the intended use, required performance, handleability, productivity, economy and the like. When used in mobile products, the thickness is preferably 0.5 μm or more, more preferably 1 μm or more as the lower limit, and the upper limit is preferably 20 μm or less, more preferably 15 μm or less, and further preferably 10 μm or less. By setting the thickness of the hard coat layer to 0.5 μm or more, necessary coating film hardness, scratch resistance, weather resistance, and substrate adhesion can be obtained. By setting the thickness of the hard coat layer to 20 μm or less, it is possible to suppress a decrease in productivity and economy.

  The hard coat layer of the hard coat film of the present invention preferably has a pencil hardness specified in JIS K5400 of 2H or higher, more preferably 3H or higher. In the coating film whose pencil hardness is adjusted to the above value or more, it is possible to effectively prevent the surface of the hard coat layer from being damaged.

In addition, the hard coat layer of the hard coat film of the present invention is obtained by covering a # 0000 steel wool on a 3 cm ² cylindrical jig and winding it with a load of 500 g for 30 times or more, preferably 50 times or more, more preferably Is preferably adjusted so as not to cause scratches when reciprocated 70 times or more. By adjusting in this way, the required scratch resistance can be ensured and the surface of the hard coat layer can be effectively prevented from being damaged.

  The hard coat film of the present invention preferably has a substrate adhesion of 90/100 or more based on JIS K5400 between the hard coat layer and the transparent support. By making the substrate adhesion within the above range, the hard coat layer can be used without being peeled off from the transparent support when used in a mobile product.

  Further, the hard coat film of the present invention has a temperature of 60 ° C. and a relative humidity of 90% R.D. H. It is preferable that the substrate adhesion based on JIS K5400 between the hard coat layer and the transparent support after the moisture resistance test which is allowed to stand in an environment of 550 hours is 90/100 or more. By setting the substrate adhesion after the moisture resistance test within the above range, a hard coat film in which the substrate adhesion between the hard coat layer and the transparent support is maintained even after the moisture resistance test can be obtained. Furthermore, even in consideration of the environment during transportation of the hard coat film of the present invention and the long-term storage stability of mobile products, the hard coat layer can be used in a high temperature and high humidity environment without deterioration. Moreover, it is preferable that the steel wool test has the scratch resistance after the moisture resistance test as described above.

  The hard coat film of the present invention preferably has a degree of yellowing (Δb) of less than 1.0, more preferably less than 0.5, after 12 cycles of the weather resistance test specified in ASTM G-154. By setting the degree of yellowing (Δb) in the above range, even when used in mobile products used outdoors, it is difficult to yellow and a hard coat film with low coating film deterioration can be obtained. In the present invention, the degree of yellowing (Δb) indicates a value obtained by subtracting the b value (b0) before the test from the b value (b1) after the weather resistance test. Therefore, the smaller this value is, the lower the coating film deterioration is.

  As described above, as an embodiment of the hard coat film of the present invention, the one having the hard coat layer on one surface of the transparent support has been described. The present invention is not limited to the above-described configuration, and has a hard coat layer on both sides of the transparent support, or a pressure-sensitive adhesive layer and a print on the side of the transparent support that does not have the hard coat layer. Those having a layer and a vapor deposition layer are also included.

  The hard coat film of the present invention as described above does not turn yellow because it has sufficient weather resistance even when used for display screens of mobile products such as mobile phones and smartphones used outdoors. Moreover, since the substrate adhesion is excellent, it can be used without causing peeling between the hard coat layer and the transparent support. In particular, the hard coat film of the present invention does not deteriorate the hard coat layer in a high-temperature and high-humidity environment, and is excellent in substrate adhesion even in such an environment. For this reason, for example, even when the production base of each component of the mobile product is different from the assembly base of the mobile product, it can be used in a high-temperature and high-humidity environment during manufacture and transportation of various components. In particular, in recent years, there has been a tendency to add a large amount of ultraviolet absorbers and light stabilizers to the hard coat layer in order to cope with a higher level of weather resistance, and various problems have arisen. The technique of the present invention is useful as a hard coat film.

  EXAMPLES Hereinafter, although this invention is demonstrated concretely based on an Example, this invention is not limited to these Examples.

<Constituent components of coating composition>
Details of each component used in the following Examples and Comparative Examples are shown below.
(A) (Meth) acrylate monomer (energy ray curable monomer)
A1: Dipentaerythritol hexaacrylate monomer (trade name: Light acrylate DPE-6A, manufactured by Kyoeisha Chemical Co., Ltd., energy ray curable functional group number: 6, hydroxyl group number: 0, weight average molecular weight 563, energy ray curable functional group number (E : 6)

  A2: Dipentaerythritol triacrylate monomer (trade name Light acrylate PE-3A, manufactured by Kyoeisha Chemical Co., Ltd., number of energy ray-curable functional groups (E): 3, number of hydroxyl groups: 1, weight average molecular weight 298)

  A'1: Epoxy acrylate monomer (trade name: Epoxy ester 200PA, manufactured by Kyoeisha Chemical Co., Ltd., number of energy ray-curable functional groups (E): 2, number of hydroxyl groups: 2, weight average molecular weight 332)

  A′2: 2-hydroxy-3-acryloyloxypropyl methacrylate monomer (trade name: NK ester 701A, manufactured by Shin-Nakamura Chemical Co., Ltd., number of energy ray-curable functional groups (E): 2, number of hydroxyl groups: 1, weight average Molecular weight 214)

A'3: Polyethylene glycol # 1000 diacrylate monomer (trade name: NK ester A-1000, manufactured by Shin-Nakamura Chemical Co., Ltd., number of energy ray-curable functional groups (E): 2, hydroxyl number: 0, weight average molecular weight 1108)
A′4: Methoxypolyethylene glycol # 400 acrylate monomer (trade name: NK ester AM-90G, manufactured by Shin-Nakamura Chemical Co., Ltd., number of energy ray-curable functional groups (E): 1, hydroxyl number: 0, weight average molecular weight 454)

(B) Ultraviolet absorber B: Energy ray curable benzotriazole ultraviolet absorber (trade name: RUVA-93, manufactured by Otsuka Chemical Co., Ltd., in a wavelength range of 280 nm to 370 nm in a 0.0619 mmol / l solution dissolved in dichloromethane (Maximum absorbance is 0.6 or more)

  B'1: Benzotriazole ultraviolet absorber that is not energy ray curable (trade name: Tinuvin 928, manufactured by BASF)

  B'2: Benzophenone-based ultraviolet absorber that is not energy ray curable (trade name: LS-907, manufactured by Yushi Kogyo Co., Ltd.)

(C) (Meth) acrylate oligomer (energy ray curable oligomer)
C1: Aliphatic urethane acrylate oligomer (trade name: Art Resin UN-904, manufactured by Negami Kogyo Co., Ltd., number of energy ray-curable functional groups: 10, weight average molecular weight 4900)

  C2: Aliphatic urethane acrylate oligomer (trade name: Art Resin UN-3320HS, manufactured by Negami Kogyo Co., Ltd., number of energy ray-curable functional groups: 15, weight average molecular weight 4900)

(D) Light stabilizer (D) Component: Hindered amine light stabilizer (trade name: Tinuvin 765, manufactured by BASF)

(E) Photopolymerization initiator E1-1: Bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide (trade name: Irgacure 819, manufactured by BASF)
E1-1: 2-dimethylamino-2- (4-methyl-benzyl) -1- (4-morpholin-4-yl-phenyl) -butan-1-one (trade name: Irgacure 379, manufactured by BASF)

E2: 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one (trade name: Irgacure 907, manufactured by BASF)
E1,2: 2,2-dimethoxy-1,2-diphenylethane-1-one (trade name: Irgacure 651, manufactured by BASF)

1. Preparation of Coating Composition and Hard Coat Film The solid contents shown in Tables 1 to 5 are (A) (meth) acrylate monomers, (B) ultraviolet absorbers and (C) (meth) acrylate oligomers shown in Tables 1 to 5. Weighed by ratio (parts by mass). Details of each component are as described above. Furthermore, (D) 1 part by weight of a light stabilizer, (E) bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide (trade name: Irgacure 819, BASF) as a photopolymerization initiator And (E-2) 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one (trade name: Irgacure 907, manufactured by BASF) 4 parts by mass were added. In addition, about Example 4 to Example 14 shown in Table 2, the photoinitiator described in Table 2 was added by the mass ratio shown in Table 2. The above components were mixed and stirred together with 75 parts by mass of methyl ethyl ketone (MEK) and 75 parts by mass of propylene glycol monomethyl ether (PGM) to obtain coating compositions (solid content 43%) of Examples and Comparative Examples. Next, as a transparent support, the coating compositions of Examples and Comparative Examples were applied to one surface of a polyethylene terephthalate film (trade name: Cosmo Shine A4300, manufactured by Toyobo Co., Ltd.) having a thickness of 188 μm by a bar coating method. After drying for 2 minutes, a hard coat layer having a film thickness of 6 μm was formed by irradiating with a high pressure mercury lamp at 300 mJ / cm ² and curing to obtain a hard coat film of each example and comparative example.

2. Evaluation Regarding the obtained hard coat films of Examples and Comparative Examples, the following methods were measured or evaluated for four items of coating film hardness (pencil hardness), scratch resistance, weather resistance, and substrate adhesion. The results of Examples 1 to 3 and Comparative Examples 1 to 7 are shown in Table 1, the results of Examples 4 to 14 are shown in Table 2, the results of Examples 15 to 18 are shown in Table 3, and The results of Examples 19 to 22 are shown in Table 4, and the results of Examples 23 to 25 are shown in Table 5.

[Coating hardness]
According to JIS K5400, the pencil hardness of the hard coat films of Examples and Comparative Examples was measured using a pencil scratch tester. Specifically, the surface of the hard coat film having the hard coat layer facing upward, the pencil set at an angle of 45 degrees, scratched 5 mm at a load of 1000 g from above, and the hardness of the pencil that was not damaged more than 4 times out of 5 times. Was recorded.

[Abrasion resistance]
<Initial scratch resistance>
As a steel wool resistance test, a steel wool of # 0000 covered with a 3 cm ² cylindrical jig was placed on the hard coat layer of the hard coat film of Examples and Comparative Examples and reciprocated at a load of 500 g. The number of times immediately before the scratch was first generated was recorded as an initial scratch resistance evaluation value.
<Abrasion resistance after moisture resistance test>
Using the hard coat films of Examples and Comparative Examples after the moisture resistance test described later, the measurement was performed in the same manner as in the initial steel wool resistance test, and the number of scratches immediately before the first occurrence of scratches was determined after the moisture resistance test. It was recorded as a sex evaluation value.

[Weather resistance (Δb)]
As a weather resistance test, according to ASTM G-154, using a QUV ultraviolet fluorescence accelerator (manufactured by Q-LAB), the hard coat films of the examples and comparative examples were UVA340 lamps for 8 hours in an environment of 60 ° C. After irradiating with ultraviolet rays, each hard coat film was allowed to condense in a dark room state and left in a condensation environment at room temperature of 50 ° C. for 4 hours. This was regarded as one cycle and carried out 12 cycles. The yellowing degree (Δb) after 12 cycles was measured using a spectrocolorimeter (trade name: CM-5, manufactured by Konica Minolta Sensing) and recorded as an evaluation value of weather resistance.

[Base material adhesion]
<Initial substrate adhesion>
As a base material adhesion test, according to the cross-cut tape method of JIS K5400, the hard coat layers of the hard coat films of Examples and Comparative Examples were cut so that 100 squares with a gap interval of 1 mm were formed, and JIS Z1522. After the cellophane pressure-sensitive adhesive tape specified in 1 was adhered and peeled off, the number of coating films remaining on the transparent support was visually counted and recorded as an initial evaluation value of substrate adhesion.

<Base material adhesion after weather resistance test>
Using the hard coat film after the weather resistance test, it was measured in the same manner as the initial substrate adhesion test, and recorded as an evaluation value of the substrate adhesion after the weather resistance test.

<Base material adhesion after moisture resistance test>
As a moisture resistance test, a temperature of 60 ° C. and a relative humidity of 90% R.D. H. After being left in this environment for 550 hours, the measurement was performed in the same manner as in the initial substrate adhesion test, and recorded as an evaluation value of the substrate adhesion after the moisture resistance test.

In Table 1, the various characteristic evaluation result of the hard coat film of Examples 1-3 and Comparative Examples 1-7 is shown.
The hard coat film obtained from the coating composition of Comparative Example 1 containing no oligomer component and using a high-hardness monomer (A2) having 3 energy ray-curable functional groups has good hardness and scratch resistance. I understood it. However, in the coating composition of Comparative Example 1, the curing shrinkage was large, and a large warp occurred in the hard coat layer. In addition, the hard coat film of Comparative Example 1 had low initial substrate adhesion, and after the weather resistance test and after the moisture resistance test, a further significant decrease was observed, confirming that it was not suitable for practical use. In Comparative Example 1, it is considered that the curing shrinkage was increased because no oligomer was present. Similar curing shrinkage was observed when A1 was used instead of A2. Moreover, in the hard coat film of the comparative example 1, it was confirmed that weather resistance is not enough. Although the number of hydroxyl groups in A2 is 1, in Comparative Example 1, since the oligomer is not included, the amount of hydroxyl groups in the entire coating composition is large, and thus it is considered that the unreacted hydroxyl groups remain after curing. It is done.
Although not described in the table, the hard coat film obtained from the coating composition containing 100 parts by mass of C1 which is an oligomer component without containing a monomer component has good pencil hardness and scratch resistance. It was confirmed that sufficient adhesion to the substrate could not be obtained.
In contrast, in Example 1 containing the monomer component A1 and the oligomer component C1, Example 2 containing the monomer component A2 and the oligomer component C1, and Example 3 containing the monomer component A1 and the oligomer component C2, all It was found that a hard coat film excellent in coating film hardness, scratch resistance, weather resistance and substrate adhesion was obtained.

On the other hand, from the coating composition of Comparative Example 2 containing monomer component A′1 (weight average molecular weight: 332, hydroxyl group: 2, energy beam curable functional group number 2) and oligomer component C1 (mass average molecular weight: 4900). In the obtained hard coat film, hardness and scratch resistance were reduced as compared with Examples 1 to 3. Further, it was confirmed that the weather resistance was lowered and yellowed after irradiation with ultraviolet rays, and the adhesion to the substrate was lowered after the weather resistance test and the moisture resistance test. Since A′1 has two hydroxyl groups, the decrease in the above characteristics is considered to be the effect of residual hydroxyl groups and / or water adsorbed on the residual hydroxyl groups.
It was obtained from the coating composition of Comparative Example 3 containing monomer component A′2 (weight average molecular weight: 214, hydroxyl group: 1, energy ray-curable functional group number 2) and oligomer component C1 (weight average molecular weight: 4900). Even in the hard coat film, the hardness and scratch resistance were reduced as compared with Examples 1 to 3. This is considered due to the fact that the weight average molecular weight of A′2 is as small as 214. Furthermore, in the hard coat film of Comparative Example 3, it was confirmed that the weather resistance was lowered and yellowed after the ultraviolet irradiation, and the adhesion to the substrate was lowered after the weather resistance test and the moisture resistance test. Although A′2 has one hydroxyl group, the molecular weight is small, so the number of hydroxyl groups in the entire coating composition is large, and excess hydroxyl groups remain even after curing. It is considered that such deterioration of properties occurs due to the influence of the water.

Obtained from the coating composition of Comparative Example 4 containing monomer component A′3 (weight average molecular weight: 1108, hydroxyl group: 0, number of energy ray-curable functional groups: 2) and oligomer component C1 (weight average molecular weight: 4900). Even in the hard coat film, the hardness and scratch resistance were reduced as compared with Examples 1 to 3. This is presumably because the monomer component A′3 could not enter the gap between the oligomer components because the weight average molecular weight of A′3 was as large as 1108, and the crosslinking density did not increase. Furthermore, in the hard coat film of Comparative Example 4, it was also confirmed that the adhesion with the substrate was lowered after the weather resistance test and the moisture resistance test. In Comparative Example 4, since the molecular weight of the monomer component is large, the crosslink density is not improved, so that it is difficult to form a bond with the surface of the base material.
Obtained from the coating composition of Comparative Example 5 containing monomer component A′4 (weight average molecular weight: 454, hydroxyl group: 0, number of energy ray-curable functional groups: 1) and oligomer component C1 (weight average molecular weight: 4900). Even with the hard coat film, the hardness and scratch resistance were significantly reduced as compared with Examples 1-3. This is considered to result from the fact that the number of energy ray-curable functional groups of A′4 is one and sufficient crosslinking reaction does not proceed. Furthermore, in the hard coat film of Comparative Example 5, the weather resistance and the initial base material adhesion were low, and it was also confirmed that the adhesion to the substrate was further lowered after the weather resistance test and after the moisture resistance test. As described above, in Comparative Example 5, since the number of energy ray-curable functional groups is small, sufficient crosslinking reaction does not proceed, and it is considered that the initial adhesion with the substrate is low. In addition, since it has a low crosslink density, it is considered that it is likely to deteriorate under ultraviolet irradiation or a high humidity environment, which is a cause of a decrease in weather resistance and substrate adhesion after various tests.

In Comparative Examples 6 and 7 using an ultraviolet absorber that is not energy ray curable in place of B1 that is an energy ray curable ultraviolet absorber, the hardness and scratch resistance are low compared to the Examples, and the weather resistance It was found that the adhesion to the substrate was lowered after the property test and after the moisture resistance test.
From the above results, a (meth) acrylate monomer having a predetermined molecular weight, the number of energy ray-curable functional groups and the number of hydroxyl groups, an energy ray-curable oligomer having a predetermined molecular weight, and an energy ray-curable functional group-containing ultraviolet absorber are contained. It was found that the hard coat film obtained from the coating composition of the present invention can provide excellent scratch resistance, weather resistance and substrate adhesion.

In Table 2, the base-material adhesiveness evaluation result of the hard coat film of Examples 4-14 is shown.
In Examples 4 to 14, the types and amounts of (A) (meth) acrylate monomer, (B) ultraviolet absorber, (C) acrylate oligomer, and (D) light stabilizer are the same as in Example 1 ( E) The kind and compounding ratio of the photopolymerizer are changed. In Example 4, 7 parts by mass of E1 alone is added as a photopolymerization agent, in Example 9, only 7 parts by mass of E2 is added, and in Examples 1 and 5-8, the blending ratio of E1 and E2 is changed. The total amount is 7 parts by mass. Here, compared to Examples 4 and 9 containing either E1 or E2, in Examples 1 and 5-8 containing E1 and E2, the substrate adhesion after the weather resistance test and after the moisture resistance test Was found to improve. In particular, in Examples 1 and 5 to 6, the substrate adhesion after the moisture resistance test is greatly improved.
In Example 10, two kinds of photopolymerization initiators E1 having a maximum absorbance of 0.1 or more in a wavelength range of 340 nm to 400 nm of a 0.01 mass% methanol solution or acetonitrile solution were added. As in the above example using both E2 and E2, the effect of greatly suppressing the decrease in substrate adhesion after the weather resistance test and after the moisture resistance test was not observed. Furthermore, in Example 11, the maximum value of the absorbance in the wavelength range of 340 nm to 400 nm of a 0.01 mass% methanol solution or acetonitrile solution is 0.1 or more, and 220 nm to 280 nm in a 0.001 mass% methanol solution. One photopolymerization initiator having a maximum absorbance of 0.1 or more in the wavelength range was added. However, as in the examples using both E1 and E2, the effect of greatly suppressing the decrease in substrate adhesion after the weather resistance test and after the moisture resistance test was not obtained.
In Examples 12 to 14, the types of photopolymerization initiators E1 and E2 and the ratio of both (E1: E2 = 3: 4) are the same as in Example 1, and are the total amount of photopolymerization initiators E1 and E2. The mass ratio is changed. The mass ratio of the total amount of E1 and E2 of Example 12, Example 1, Example 13, and Example 14 is 3.5, 7, 10.5, and 14, respectively. In any of the examples, it was confirmed that excellent substrate adhesion was maintained both after the weather resistance test and after the moisture resistance test.
From the above results, it was confirmed that the use of two kinds of photopolymerization agents having a predetermined absorbance in a predetermined wavelength range is effective for improving the adhesion of the substrate.

Table 3 shows various evaluation results of the hard coat films of Examples 15 to 18.
In Examples 12 to 15, (A) (meth) acrylate monomer, (B) ultraviolet absorber, (C) (meth) acrylate oligomer, (D) light stabilizer, (E) type of photopolymerizer, and (B The compounding amounts of (A) (meth) acrylate monomer and (C) (meth) acrylate oligomer are the same as in Example 1 for the blending amounts of UV absorber, (D) light stabilizer, and (E) photopolymerizer. Is changing.
Here, since the high-hardness monomer (A1) is used, the pencil hardness and scratch resistance are improved as the amount of the monomer is increased. Moreover, it turned out that the outstanding weather resistance and base-material adhesiveness are obtained also in any Example. Particularly, in Example 16, Example 1 and Example 17 in which the content ratio of the component (A) and the component (C) is in the range of 3:97 to 50:50 by mass ratio, the substrate adhesion after the moisture resistance test It was confirmed that the performance was greatly improved.

Table 4 shows various evaluation results of the hard coat films of Examples 19 to 22.
In Example 19 and Example 22, a hard coat film was produced and evaluated in the same manner as in Example 1 except that the thickness of the hard coat layer was changed as shown in Table 4. It was confirmed that the scratch resistance was further improved by increasing the thickness of the hard coat layer to 3 μm, 6 μm and 15 μm. However, it was found that sufficient scratch resistance, substrate adhesion and weather resistance were obtained in any of the examples.
In Example 21 and Example 22, a hard coat film was prepared and evaluated in the same manner as in Example 1 except that the addition amount of the ultraviolet absorber (B1) was changed as shown in Table 4. In any of the examples, it was found that sufficient scratch resistance, substrate adhesion and weather resistance were obtained.

Table 5 shows various evaluation results of the hard coat films of Examples 23 to 25.
In Example 23 and Example 25, a hard coat film was prepared and evaluated in the same manner as in Example 1 except that the amount of (D) light stabilizer added to the coating composition was changed as shown in Table 5. It was. In any of the examples, it was found that sufficient scratch resistance, weather resistance and substrate adhesion were obtained.

Claims (9)

  (A) an energy ray-curable (meth) acrylate monomer having a weight average molecular weight of 250 to 1,000, an energy ray-curable functional group number of 2 to 9, and a hydroxyl group number of 1 or less; A coating composition comprising a functional functional group-containing ultraviolet absorber and (C) an energy ray-curable oligomer having a weight average molecular weight of 1500 to 20000.   (E1) a photopolymerization initiator having a maximum absorbance of 0.1 or more in a wavelength range of 340 nm to 400 nm of a 0.01 mass% methanol solution or acetonitrile solution, and (E2) a 0.001 mass% methanol solution. The coating composition according to claim 1, further comprising a photopolymerization initiator having a maximum absorbance of 0.1 or more in a wavelength range of 220 nm to 280 nm of the acetonitrile solution.   The coating composition according to claim 1 or 2, wherein a mass ratio of the component (A) to the component (C) (component (A): component (C)) is 3:97 to 50:50. object.   The component (B) is an ultraviolet absorber having a maximum absorbance of 0.6 or more in a wavelength range of 280 nm to 370 nm in a 0.0619 mmol / l dichloromethane solution. The coating composition according to any one of the above.   A hard coat film comprising a hard coat layer obtained from the coating composition according to any one of claims 1 to 4 on at least one surface of a transparent support.   The hard coat film according to claim 5, wherein the hard coat layer has a thickness of 0.5 μm or more and 20 μm or less.   The hard coat film according to claim 5 or 6, wherein the substrate adhesion between the hard coat layer and the transparent support is 90/100 or more based on JIS K5400.   Temperature 60 ° C., relative humidity 90% H. The substrate adhesion between the hard coat layer and the transparent support after being subjected to a humidity resistance test that is allowed to stand in an environment of 550 hours is 90/100 or more based on JIS K5400. The hard coat film of any one.   The hard coat film according to any one of claims 5 to 8, wherein the yellowing degree (Δb) after 12 cycles of the weather resistance test specified in ASTM G-154 is less than 1.