TWI637032B - Coating composition and hard coating film using same - Google Patents

Abstract

The present invention provides a coating composition for a hard-coated film and a hard-coated film that are excellent in weather resistance while maintaining excellent scratch resistance and adhesion to a substrate. Furthermore, the present invention provides a coating composition for a hard-coated film and a hard-coated film which are excellent in adhesiveness of a substrate even after storage in a high-temperature and humid environment. A hard-coated film is prepared from a coating composition containing (A) an energy-ray curable material having a weight average molecular weight of 250 or more and 1,000 or less, an energy-ray curable functional group number of 2 or more and 9 or less, and a hydroxyl number of 1 or less. (Meth) acrylic acid ester monomer, (B) an ultraviolet ray absorbent containing an energy ray curable functional group, and (C) an energy ray curable oligomer having a weight average molecular weight of 1,500 to 20,000.

Description

Coating composition and hard coating film using same

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

Conventionally, in order to prevent the surface of glass and resin moldings from being damaged, a hard coating film is applied to the surface by coating a coating coating made of an energy ray-curable resin or the like, or a hard coating having a hard coating on a resin film is provided. A film is used by sticking to this glass or resin molding.

The above hard-coated film and hard-coated film are widely used for display screens, such as displays, touch panels, and mobile phones. In particular, mobile products such as mobile phones and smart phones are increasingly used outdoors. As a hard coating film for such outdoor use, it is necessary to prevent yellowing even when exposed to ultraviolet rays for a long time. Therefore, it is proposed to add an ultraviolet absorber and a light stabilizer to the hard coat layer for the purpose of imparting weather resistance (Patent Document 1).

Prior art literature

Patent literature

Patent Document 1: Japanese Patent Application Laid-Open No. 9-157315

However, the hard-coated film proposed in Patent Document 1 has the following problems: the addition of an ultraviolet absorber and a light stabilizer causes curing failure, coating film hardness, abrasion resistance, and dense substrate Connectivity drops. This problem is significant when a large amount of ultraviolet absorbers and light stabilizers are added in order to cope with a higher level of weather resistance.

In addition, in order to suppress the production cost of the above-mentioned mobile products, in most cases, the production location of each component and the assembly location of the mobile product are different. In consideration of the high temperature and humidity environment during the manufacture and transportation of various components, and the long-term preservation of the mobile product, it is necessary to The hard coating does not deteriorate (abrasion resistance) under high temperature and humidity conditions. Furthermore, it is necessary to have excellent substrate adhesion without peeling between the hard coat layer and the transparent support even in such an environment.

Therefore, an object of the present invention is to provide a coating composition for a hard-coated film and a hard-coated film which improve the above-mentioned disadvantages and maintain excellent scratch resistance and substrate adhesion while maintaining good weather resistance. Furthermore, an object of the present invention is to provide a coating composition for a hard coating film and a hard coating film which are excellent in adhesiveness of a substrate even after storage in a high temperature and humidity environment.

The present inventors conducted intensive studies in order to solve the above-mentioned problems, and as a result, found that by using 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, A coating composition of a specific molecular weight energy ray curable (meth) acrylate oligomer and a specific ultraviolet absorber can solve the above-mentioned problems and completed the present invention.

In addition, (meth) acrylate means an acrylate or a methacrylate.

That is, according to the present invention, there are provided a coating composition and a hard coating film having the following configurations.

The coating composition of the present invention is characterized by containing (A) an energy ray curable (meth) acrylate having a weight average molecular weight of 250 or more and 1000 or less, an energy ray curable functional group of 2 or more and 9 or less, and a hydroxyl number of 1 or less. Monomer, (B) Violet containing energy ray curable functional group External-ray absorbent, and (C) an energy-ray-curable oligomer having a weight average molecular weight of 1,500 to 20,000.

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

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

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

The hard-coated film of the present invention is characterized by having a hard-coat layer obtained from the coating composition on at least one side of a transparent support.

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

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

In addition, the hard-coated film of the present invention is preferably 90/100 based on JIS K5400 adhesion between the hard coat and the substrate of the transparent support after a humidity resistance test in an environment at a temperature of 60 ° C and a relative humidity of 90% RH for 550 hours the above.

In addition, the hard coating film of the present invention preferably has a yellowness (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 coating composition for a hard-coated film and a hard-coated film that are excellent in abrasion resistance, weather resistance, and adhesion to a substrate.

Hereinafter, embodiments of the present invention will be described in detail.

(1) Coating composition

The coating composition of the present invention is characterized by containing (A) an energy ray curable (meth) acrylate having a weight average molecular weight of 250 or more and 1000 or less, an energy ray curable functional group of 2 or more and 9 or less, and a hydroxyl number of 1 or less. Monomer, (B) an ultraviolet ray absorbent containing an energy ray-curable functional group, and (C) an energy ray-curable oligomer having a weight average molecular weight of 1,500 to 20,000.

Each component is explained below.

(A) Energy ray curable (meth) acrylate monomer

In the coating composition of the present invention, it is necessary to use an energy ray curable (meth) acrylate monomer having a weight average molecular weight of 250 or more and 1,000 or less, an energy ray curable functional group number of 2 or more and 9 or less, and a hydroxyl number of 1 or less. By using such a monomer, hardness, abrasion resistance, and adhesiveness of a substrate can be improved. In particular, it is possible to effectively improve the adhesion of the substrate in a high-temperature and humid environment.

By setting the weight-average molecular weight of the (meth) acrylate monomer to 250 or more, it is possible to have film properties when it is used as a hard coat layer. Therefore, it is possible to suppress a decrease in scratch resistance while improving the adhesiveness of the substrate. In addition, in the manufacturing process of the hard coat layer, it is possible to prevent the The reaction monomer was volatilized. On the other hand, by setting the weight-average molecular weight to 1,000 or less, the molecular weight is not too large, and therefore it is easy to arrange the component (A) in the molecular gap between the component (B) and the component (C) as described later. Therefore, it is possible to suppress the decrease in the scratch resistance due to the addition of the ultraviolet absorber while improving the crosslinking efficiency and the adhesiveness of the substrate. In addition, it is possible to prevent an increase in viscosity when the coating liquid for a hard coat layer is prepared. In addition, the weight average molecular weight of a (meth) acrylate monomer can be confirmed by gel permeation chromatography (GPC).

By setting the number of hydroxyl groups of the (meth) acrylic acid ester monomer to 1 or less, it is possible to suppress a decrease in the adhesiveness of the substrate in a high-temperature and humid environment. In the present invention, since the energy ray-curable monomer having a weight average molecular weight of 250 or more and 1,000 or less is used as described above, sufficient substrate adhesion can be obtained even without a hydroxyl group. When the (meth) acrylic acid ester monomer has one hydroxyl group, the reaction between the acidic functional group existing on the surface of the transparent support, that is, the glass and the resin substrate, and the hydroxyl group improves the adhesion, so the substrate can be further improved. Tightness.

When a monomer having a hydroxyl number of 2 or more is used, it is advantageous in terms of improving the bonding property by a reaction with a functional group on the surface of the transparent support. However, since unreacted hydroxyl groups are present in the hard coat layer, the influence of residual hydroxyl groups in a high-temperature and humid environment causes the adhesiveness of the substrate to decrease. In the present invention, since the number of hydroxyl groups of the (meth) acrylic acid ester monomer is set to 1 or less, unreacted hydroxyl groups hardly exist after the curing reaction, so it is possible to suppress the residual hydroxyl groups even in a high-temperature and humid environment. The adhesiveness of the substrate is reduced.

In addition, by setting the number of energy ray-curable functional groups of the (meth) acrylate monomer to 2 or more and 9 or less, a hard-coated film having high hardness, excellent abrasion resistance, and excellent substrate adhesion can be obtained. By using a (meth) acrylate monomer having an energy ray-curable functional group of 2 or more, a cross-linking reaction with the component (B) and the component (C) can be performed more effectively. It is possible to suppress the decrease in abrasion resistance due to the addition of the ultraviolet absorber while improving the adhesiveness of the substrate. 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-coated film having high hardness and excellent abrasion resistance. In addition, if such a (meth) acrylate monomer is used, the cross-linking reaction does not sufficiently proceed, so that the obtained hard coat film is liable to be deteriorated by ultraviolet rays, and it is difficult to obtain excellent weather resistance. Furthermore, since the crosslinking reaction does not sufficiently proceed, it is difficult to obtain excellent substrate adhesion.

On the other hand, if a (meth) acrylate monomer having an energy ray-curable functional group of 9 or less is used, it is easy to arrange the (A) component in the molecular gap between the (B) component and (C) component, and the crosslinking efficiency Since it also improves, the adhesiveness of a base material improves, and the fall of abrasion resistance by the addition of an ultraviolet absorber can be suppressed. When a (meth) acrylic acid monomer having an energy ray-curable functional group exceeding 9 is used, the (A) components are likely to undergo an excessive cross-linking reaction, so it is difficult to arrange the (A) components in the (B) components and (C). In the molecular gaps of the components, the crosslinking density is difficult to increase, so it is difficult to obtain a hard-coated film having excellent scratch resistance and substrate adhesion.

Examples of the (A) (meth) acrylate monomer include dipentaerythritol hexa (meth) acrylate, trimethylolpropane (meth) acrylate, pentaerythritol tri (meth) acrylate, and ethyl acetate. Diethylene glycol di (meth) acrylate, triethylene glycol divinyl ether, tetraethylene glycol (meth) acrylate, tripropylene glycol (meth) acrylate, 1,4-butanediol di (meth) acrylic acid Ester, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, trimethylolpropane trihydroxyethyl (meth) acrylate, tris (2-hydroxy) Ethyl) isocyanurate tri (meth) acrylate, dipentaerythritol polyacrylate, dipentaerythritol hexaacrylate, tricyclodecane dimethanol diacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, trihydroxy Methylpropane triacrylate, bis (trimethylol) propane tetraacrylate. Among these, dipentaerythritol hexaacrylate, pentaerythritol triacrylate, and pentaerythritol tetraacrylate are preferred in terms of good adhesion to the transparent support and high reactivity.

(B) Ultraviolet absorbent

The coating composition of the present invention includes an ultraviolet absorbent containing an energy ray-curable functional group. Generally, in order to obtain weather resistance of a hard coat layer and a hard coat film, an ultraviolet absorber is added to the coating composition. In the present invention, since the ultraviolet absorbent contains an energy ray-curable functional ultraviolet absorbent as the ultraviolet absorbent, the cross-linking reaction between the component (A) and the component (C) described later proceeds efficiently, so that the cross-linking density can be increased and the Suppression of the abrasion resistance caused by the addition of ultraviolet absorbers is suppressed. In addition, by introducing the ultraviolet absorber into the cross-linked structure by the cross-linking reaction, bleeding from the hard coat layer is suppressed, and a decrease in the adhesiveness of the substrate can be suppressed. In particular, when the coating composition of the present invention using an ultraviolet absorbent having an energy ray-curable functional group is used in a high-temperature and humid environment, the effect of suppressing a decrease in the adhesiveness of the substrate is significantly confirmed.

As such an ultraviolet ray absorbent containing an energy ray-curable functional group, benzotriazole-based and triazine-based ultraviolet absorbers can be used. Examples of the benzotriazole-based ultraviolet absorber (compound) include 2- (2'-hydroxy-5'-methylphenyl) benzotriazole and 2- (2'-hydroxy-5'-tertiary Butylphenyl) benzotriazole, 2- (2'-hydroxy-3'-tert-butyl-5'-methylphenyl) -5-chlorobenzotriazole, 2- (2'-hydroxy- 3 ', 5'-di-tert-butylphenyl) -5-chlorobenzotriazole, 2- (2'-hydroxy-3'-tert-butyl-5'-(2- (octyloxycarbonyl) Ethyl) phenyl) -5-chlorobenzotriazole, 2- (2'-hydroxy-3'-dodecyl-5'-methylphenyl) -5-chlorobenzotriazole, 2- (2'-hydroxy-3 ', 5'-di-tert-pentylphenyl) benzotriazole, 2- (2'-hydroxy-5'-tert-octylphenyl) benzotriazole, 2- ( 2'-hydroxy-3 ', 5' -Bis- (dimethylbenzyl) phenyl) benzotriazole, 2- (2'-hydroxy-4'-octyloxyphenyl) benzotriazole, 2,2'-methylene-bis (2- (2'-hydroxy-5'-tert-octylphenyl) benzotriazole) 2- (2'-hydroxy-3 '-(3,4,5,6-tetrahydrophthalimidine Compounds having a (meth) acrylfluorenyl group such as iminomethyl) -5'-methylbenzyl) phenyl) benzotriazole. Examples of the triazine-based ultraviolet absorber (compound) include 2- (4-hexyloxy-2-hydroxyphenyl) -4,6-diphenyl-1,3,5-triazine, 2 -(4-octyloxy-2-hydroxyphenyl) -4,6-bis (2,5-dimethylphenyl) -1,3,5-triazine, 2- (4-butoxy- 2-hydroxyphenyl) -4,6-bis (4-butoxyphenyl) -1,3,5-triazine, 2- (4-butoxy-2-hydroxyphenyl) -4,6 -Bis (2,4-dibutoxyphenyl) -1,3,5-triazine, 2- (4- (3- (2-ethylhexyloxy) -2-hydroxypropoxy)- 2-hydroxyphenyl) -4,6-bis (2,4-dimethylphenyl) -1,3,5-triazine, 2- (4- (3-dodecyloxy-2-hydroxy (Propoxy) -2-hydroxyphenyl) -4,6-bis (2,4-dimethylphenyl) -1,3,5-triazine, 2,4-bis (4-butoxy- 2-hydroxyphenyl) -6- (4-butoxyphenyl) -1,3,5-triazine, 2,4-bis (4-butoxy-2-hydroxyphenyl) -6- ( 2,4-dibutoxyphenyl) -1,3,5-triazine and other compounds having a (meth) acrylfluorenyl group. Among them, in terms of excellent ultraviolet absorption performance, ultraviolet absorbers having a maximum absorbance of 0.6 or more in a wavelength range of 280 nm to 370 nm dissolved in a 0.0619 mmol / l solution of dichloromethane are preferred. As such an ultraviolet absorber, 2- (2'-hydroxy-5'-methylphenyl) benzotriazole and a compound having a (meth) acrylfluorenyl group, and 2- (4-hexyloxy) are preferably used. 2-hydroxyphenyl) -4,6-diphenyl-1,3,5-triazine and compounds having a (meth) acrylfluorenyl group. The above-mentioned energy ray-curable functional group-containing ultraviolet absorbers may be used singly or in combination of two or more kinds.

The amount of the component (B) to be added varies depending on the desired weather resistance and the thickness of the hard coat layer. The lower limit is preferably 2 parts with respect to 100 parts by mass of the total of the component (A) and the component (C) described later. It is more preferably 2.5 parts by mass or more, and still more preferably 3 parts by mass or more. The upper limit is preferably 12 parts by mass or less, more preferably 10 parts by mass or less, and still more preferably 8 parts by mass or less. By setting the lower limit to 2 parts by mass or more, better weather resistance can be obtained, and by setting the upper limit to 12 parts by mass or less, excellent coating film hardness, scratch resistance, and substrate adhesion can be maintained.

(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 1,500 to 20,000. From the coating composition containing the oligomer, a hard coat layer and a hard coat film having good coating film hardness and abrasion 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. In addition, by setting the weight average molecular weight of the energy ray-curable oligomer to 20,000 or less, and preferably 10,000 or less, a hard coating film or a hard coating film having good coating film hardness and scratch resistance can be obtained.

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). When the ratio of the weight average molecular weight of the energy ray curable oligomer to the weight average molecular weight of the energy ray curable monomer is within the above range, the energy ray curable monomer easily enters the gap between the energy ray curable oligomers. By performing the crosslinking reaction in a more dense state, the crosslinking density increases, thereby effectively suppressing the decrease in hardness and scratch resistance caused by the addition of the ultraviolet absorber. In addition, here, the weight average molecular weight of an energy-ray-curable monomer and an energy-ray-curable oligomer is based on the gel Values obtained by permeation chromatography (GPC).

As the energy ray-curable oligomer, a (meth) acrylic oligomer having two or more (meth) acrylfluorene groups in one molecule and cross-linked and cured to form a three-dimensional mesh structure is particularly preferably used. Examples of such a (meth) acrylic oligomer include polyurethane (meth) acrylate, polyester (meth) acrylate, epoxy (meth) acrylate, and melamine (meth) acrylic acid. Esters, polyfluoroalkyl acrylates, silicone acrylates, and the like.

The energy ray-curable oligomer is preferably a polyfunctional polyurethane (meth) acrylate oligomer having an energy ray-curable functional group of 10 or more and 20 or less. By using such a polyfunctional urethane (meth) acrylate oligomer, a high crosslinking density can be achieved, and thus the hardness of the coating film 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 improved. As a result, abrasion resistance can be improved significantly. In addition, by setting the number of energy ray-curable functional groups to 20 or less, preferably 16 or less, steric hindrance due to high cross-link density can be suppressed, and a decrease in hardness due to curing failure can be prevented.

The content ratio of the (A) component (energy ray curable monomer) and (C) component (energy ray curable oligomer) in the coating composition of the present invention is preferably 3:97 to 50:50 in terms of mass ratio. , More preferably 5:95 to 30:70. When the mass ratio of the component (A) to the component (C) in the coating composition is in the above range, the adhesion of the substrate of the hard coat layer and the transparent support, particularly the adhesion of the substrate after the moisture resistance test can be made. Better.

(D) Light stabilizer

The coating composition of the present invention preferably contains a hindered amine-based light stabilizer as the (D) light stabilizer. By adding a hindered amine-based light stabilizer to the hard coat layer, it is possible to efficiently capture factors Free radicals generated by ultraviolet rays can further improve weather resistance. Examples of the (D) light stabilizer include 4-benzoyloxy-2,2,6,6-tetramethylpiperidine and 4-hexanoyloxy-2,2,6,6-tetramethyl Methylpiperidine, 4-octanoyloxy-2,2,6,6-tetramethylpiperidine, 4-stearoyloxy-2,2,6,6-tetramethylpiperidine, succinic acid -Bis (2,2,6,6-tetramethylpiperidine), sebacic acid-bis (2,2,6,6-tetramethylpiperidine), sebacic 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-piperidyl) pyrrolidine- 2,5-dione, N-acetyl-3-dodecyl-1- (2,2,6,6-tetramethyl-4-piperidinyl) pyrrolidine-2,5-dione, Phthalic acid-bis (1,2,2,6,6-pentamethyl-4-piperidine), trimesic acid-tris (2,2,6,6-tetramethyl-4-piperidinyl) ) Esters. They can be used alone or in combination of two or more.

The lower limit of the amount of the component (D) added to 100 parts by mass of the total of the components (A) and (C) is preferably 0.05 parts by mass or more, more preferably 0.5 parts by mass or more, and the upper limit is preferably 5 parts by mass. Parts or less, more preferably 3 parts by mass or less. When the addition amount of the (D) component is 0.05 parts by mass or more, better 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 preferably contains light having a maximum absorbance of 0.1% or more in a wavelength range of 340 to 400 nm of a 0.01% by mass solution obtained by dissolving (E1) in methanol or acetonitrile. The polymerization initiator, (E2) was dissolved in methanol or acetonitrile, and the 0.001% by mass solution had the highest absorbance in the wavelength range of 220nm to 280nm. Each of the photopolymerization initiators having a large value of 0.1 or more. When a cured coating film is formed by ultraviolet irradiation, by using these two types of photopolymerization initiators, it is possible to significantly suppress a decrease in the adhesiveness of the substrate in a high-temperature and humid environment, as compared with the case of using them separately.

〔(E1) component〕

The component (E1) used in the present invention is a photopolymerization initiator in which a 0.01% by mass solution obtained by dissolving in methanol or acetonitrile has a maximum absorbance of 0.1 or more in a wavelength range of 340 nm to 400 nm. Examples include 1-hydroxy-cyclohexyl-phenyl-one, 2,2-dimethoxy-1,2-diphenylethane-1-one, and bis (2,4,6-trimethyl Benzamidine) -phenylphosphine oxide, 2-benzyl-2-dimethylamino-1- (4-morpholinylphenyl) -1-butanone, bis (η5-2,4-cyclopentyl Dien-1-yl) -bis (2,6-difluoro-3- (1H-pyrrole-1-yl) -phenyl) titanium, 2-dimethylamino-2- (4-methylbenzyl ) -1- (4-morpholinylphenyl) butanone, diphenyl (2,4,6-trimethylbenzylidene) phosphine oxide, and the like. These components may be used alone or in combination of two or more.

(E1) As a component, a commercial item can be used, For example, Irgacure 651, 907, 819, 369, 379, 1800, 784, Darocur 4265, Lucirin TPO (The above is a product of BASF company), etc. are mentioned.

〔(E2) component〕

The (E2) component 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% by mass solution obtained by dissolving in methanol or acetonitrile. Examples include 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinylpropane-1-one, 2,2-dimethoxy-1,2-diphenyl Ethane-1-one, 1- [4- (2-hydroxyethoxy) -phenyl] -2-hydroxy-2-methyl-1-propane-1- Ketone, 2-hydroxy-2-methyl-1-phenyl-propane-1-one, methyl benzoate, oligo [2-hydroxy-2-methyl- [1- (4-methylethylene Group) phenyl] acetone and the like. These components may be used alone or in combination of two or more.

(E2) As a component, a commercially available product can be used, for example, Irgacure 184, 651, 500, 2959, 127, 754, 907, 1800, Darocur 1173, MBF (above, manufactured by BASF), Esacure KIP150, KIP100F, ONE (above) (Made by Lamberti).

From the viewpoint of suppressing a decrease in the adhesiveness of the substrate in a high-temperature and humid environment, the amount of the photopolymerization initiator added to the component (E1) is preferably smaller than the amount of the photopolymerization initiator added to the component (E2). Specifically, the addition ratio of the (E1) component and the (E2) component is preferably in a range of 3:97 to 45:55 in terms of mass ratio. In addition, when multiple (E1) component and / or (E2) component are included, it is preferable that the ratio of the total mass of each of (E1) component and (E2) component is the said range.

In addition, one of the photopolymerization initiators has a photopolymerization initiation wavelength region of the (E1) component and the (E2) component. In addition, the maximum absorbance of such a photopolymerization initiator, that is, a 0.01% by mass methanol solution or an acetonitrile solution in a wavelength range of 340nm to 400nm is 0.1 or more, and a 0.001% by mass methanol solution is 220nm to 280nm. A photopolymerization initiator having a maximum absorbance in a wavelength range of 0.1 or more is called a (E1, 2) component or a photopolymerization initiator of (E1, 2). However, even when one type of (E1, 2) photopolymerization initiator is used, the effect of using two types of (E1) photopolymerization initiator and (E2) photopolymerization initiator in combination cannot be obtained. On the other hand, when two or more kinds of (E1, 2) photopolymerization initiators are used, it is confirmed that the same effect is obtained when the (E1) photopolymerization initiator is used in combination with the (E2) photopolymerization initiator. In addition, even if (E1) is further added to the photopolymerization initiator of (E1, 2) In the case of the photopolymerization initiator (E2), the same effect can be obtained. In this case, particularly by adding the (E2) component, a more excellent effect can be obtained. In addition, the kind and quantity of the polymerization initiator which is preferable as an additive in manufacture are as small as possible. However, as long as it does not affect other physical properties of the hard coat layer or the hard coat film, the photopolymerization initiator of (E1) and (E2) may be added to the photopolymerization initiator of (E1, 2). Initiator.

In this application, "containing (E1) component and (E2) component" also includes a photopolymerization initiator containing two or more (E1, 2) and a photopolymerization initiator containing (E1, 2) and (E1) The constitution of a photopolymerization initiator and / or a photopolymerization initiator of (E2).

By containing two types of photopolymerization initiators in this manner, it is possible to improve the scratch resistance and substrate adhesion of conventional hard coating films and hard coating films obtained from energy-ray-curable coating compositions having ultraviolet absorption functions. . In particular, by using the above-mentioned two types of photopolymerization initiators, it is possible to obtain a coating film in which the adhesiveness of a substrate is significantly improved in a high-temperature and humid environment.

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

Further, in the coating composition of the present invention, other resins, solvents, and photopolymerization initiation aids, leveling agents, defoaming agents, antioxidants, polymerization inhibitors, crosslinking agents, pigments, antifouling agents, Particles, lubricants, fluorescent whitening agents, antistatic agents, flame retardants, Additives such as a bactericide, a mildew-proof agent, a plasticizer, a flow regulator, a dispersant, and a release agent, etc., can each provide a target function.

Examples of other resins include epoxy-based resins such as thermosetting resins, thermoplastic resins, bisphenol-based epoxy resins, novolac-type epoxy resins, alicyclic epoxy resins, and aliphatic epoxy resins, and vinyl ether-based resins. The photocationic polymerizable resin, such as a resin, may be included in the range which does not affect the effect of this invention.

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

The type of the organic solvent to be used is determined by considering the solubility or dispersibility of the above-mentioned (A) component, (B) component, (C) component and the like to be added at the same time. Since it is difficult for the solvent to remain in the hard coat layer after drying, organic solvents having a boiling point of 120 ° C. or lower, such as methyl ethyl ketone, methyl isobutyl ketone, and tetrahydrofuran, are preferred. These organic solvents may be used singly or in combination of two or more kinds. The amount of the solvent used is not particularly limited, and it is preferred to adjust the viscosity of the composition to a viscosity suitable for the coating method used. The amount used is preferably 5 to 90% by mass of the entire composition, more preferably 10 to 85% by mass, and even more preferably 20 to 80% by mass.

Examples of the photopolymerization initiation aid include amine compounds, carboxylic acid compounds, and polyfunctional thiol compounds. Examples of the leveling agent include acrylic compounds, high-boiling solvents, fluorine-based compounds, and silicon-based compounds. From the viewpoint of processing the surface into a mirror surface, among the above-mentioned leveling agents, fluorine-based compounds and silicon-based compounds are preferred. As an antioxidant, you can give Phenol-based compounds and so on. Examples of the polymerization inhibitor include hydroquinone monomethyl ether, methylhydroquinone, and hydroquinone. Examples of the crosslinking agent include isocyanates and melamine compounds. Examples of the fine particles include inorganic fine particles such as silicon dioxide and calcium carbonate, and organic fine particles such as polymethyl methacrylate and polystyrene. Examples of the antifouling agent include a fluorine-based compound, a silicon-based compound, or a mixture thereof. In terms of antifouling performance, a fluorine-based compound is preferred.

The coating composition of the present invention may be obtained by adding the components (A), (B), and (C) in any order, and further adding other resins, solvents, light stabilizers, and photopolymerization initiators as needed. Obtained by mixing.

The coating composition of the present invention thus obtained is a coating composition (hard coating) for coating and curing the surface of a glass or a resin material. Since the hard coat coating material of the present invention contains the above-mentioned components (A), (B), and (C), when glass and a resin material are used as the coating material, the adhesion between the coating material and the cured coating film is good. . In particular, it is possible to produce a cured coating film having excellent adhesion (substrate adhesion) to a coating object and a cured coating film in a high-temperature and humid environment.

(2) Hard coating film and hard coating film

The hard-coated film of the present invention can be obtained by dissolving or dispersing the above-mentioned (A) component, (B) component, and (C) component and other resins and additives added as necessary in a solvent (hard coating layer) The composition is coated on at least one side of a transparent support, and is dried by being irradiated with energy rays or being cured by natural light as needed. The coating can be performed by a known method such as a gravure coating method, a bar coating method, a blade coating method, a roll coating method, a doctor blade coating method, a die coating method, a spin coating method, a flow coating method, a dip coating method, a spray coating method, and a screen. Printing methods, brushing, etc. If the viscosity of the hard coating composition is higher than the viscosity suitable for coating, a solvent can be used Perform viscosity adjustment. The solvents that can be used are as described above.

As the transparent support, a transparent support such as glass or a resin substrate can be used. Examples of the resin constituting the resin substrate include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polyethylene, polypropylene, and cellophane. , Diethyl cellulose, triethyl cellulose, ethyl cellulose butyrate, polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, ethylene-vinyl acetate copolymer, polystyrene, Polycarbonate, polymethylpentene, polyfluorene, polyetheretherketone, polyetherfluorene, polyetherimine, polyimide, fluororesin, nylon, propylene, cycloolefin, norbornene compounds, and the like. Among these materials, a polyethylene terephthalate film subjected to a stretching process, particularly a biaxial stretching process, is preferably used because of its excellent mechanical strength and dimensional stability.

In order to improve the adhesion between the transparent support and the hard coating layer, the surface can be roughened by a sandblasting method, a solvent treatment method, or a corona discharge treatment, a chromic acid treatment, a flame treatment, a hot air treatment, Plasma treatment, ozone. Surface treatment such as ultraviolet irradiation treatment, formation of a primer easy-bonding layer, etc. In addition, before applying the composition for a hard coat layer on a transparent support, a pressure-sensitive adhesive layer is applied to one or both surfaces in advance, and printing and coating are performed to impart design properties. In addition, the transparent support may contain additives that can be used in the aforementioned coating composition, such as an ultraviolet absorber and a light stabilizer, as long as the effects of the present invention are not affected.

The thickness of the transparent support is not particularly limited as long as it is appropriately selected according to the application. In the case of glass, it is preferably 0.3 mm to 5 mm, and in the case of a resin substrate, it is preferably 25 μm to 500 μm, and more preferably 50 μm to 300 μm.

When a solvent is included in the composition for a hard coat layer, it is necessary to perform drying after coating. The drying temperature only needs to consider the length of the drying line, the line speed, the amount of coating, the amount of residual solvent, and the permeability. The type of support and the like can be determined. If the transparent support is a polyethylene terephthalate film, the drying temperature is generally 50 ° C to 150 ° C, and preferably 70 ° C to 130 ° C. When there are multiple dryers on one line, each dryer can be set to a different temperature and wind speed. In order to obtain a coating film having a good coating appearance, it is preferable to make the drying conditions on the inlet side mild.

As a method of hardening the composition for hard-coat layers, it can harden | cure by energy-beam irradiation or natural light as mentioned above. Considering the stability of the physical properties of the hard coat layer and the industrial workability, it is preferred to cure the hard coat layer by energy ray irradiation. Examples of energy rays include ultraviolet rays and electron rays. In the case of curing by 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 and the arrangement of the light source are adjusted as necessary. If a high pressure mercury lamp, preferably a lamp having a lamp 1 with respect to 80W / cm ² ~ 160W / cm ² of energy to 5m / min ~ 60m / cured per the conveying speed. When the electron beam is used for curing, an electron beam acceleration device having an energy of 100 eV to 500 eV is preferably used.

The thickness of the hard coat layer is not particularly limited, and it may be appropriately determined according to the intended use, required function, operability, productivity, and economy. In the case of use in a mobile product, the lower limit of the thickness is preferably 0.5 μm or more, more preferably 1 μm or more, and the upper limit is preferably 20 μm or less, further preferably 15 μm or less, and still more preferably 10 μm or less. By setting the thickness of the hard coat layer to be 0.5 μm or more, desired coating film hardness, abrasion 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 is preferably adjusted so that the pencil hardness prescribed by JIS K5400 is 2H or more, and more preferably 3H or more. A coating film whose pencil hardness is adjusted above the above value can effectively prevent surface damage of the hard coating layer.

In addition, the hard coating of the hard-coated film of the present invention is preferably adjusted to be obtained by wrapping steel wool of # 0000 with a 3 cm ² cylindrical jig, and reciprocating with a load of 500 g for more than 30 times, preferably for more than 50 times, more It is preferable that no damage occurs in the case of 70 or more round trips. By adjusting in this way, the required scratch resistance can be ensured, and the surface damage of the hard coating layer can be effectively prevented.

Moreover, it is preferable that the adhesiveness of the base material of the hard-coat film and transparent support body of the hard-coated film of this invention based on JIS K5400 is 90/100 or more. When the adhesiveness of the base material is within the above range, when it is used for a mobile product, the hard coating layer can be used without peeling off the transparent support.

Furthermore, the hard coat film of the present invention is preferably placed in an environment at a temperature of 60 ° C. and a relative humidity of 90% RH for 550 hours after a humidity resistance test. The adhesion between the hard coat layer and the transparent support based on JIS K5400 is 90/100. the above. By setting the adhesion of the substrate after the moisture resistance test to the above range, it is possible to produce a hard-coated film in which the adhesion of the substrate of the hard coat layer and the transparent support is maintained after the moisture resistance test. Furthermore, in consideration of the environment during transportation of the hard-coated film of the present invention, and the long-term storage stability of mobile products, the hard-coat can be used without deterioration in a high-temperature and humid environment. In addition, it is preferable to have abrasion resistance in the same steel wool test as described above after the moisture resistance test.

In addition, the hard coating film of the present invention preferably has a yellowing degree (Δb) after 12 cycles of the weather resistance test specified in ASTM G-154 of less than 1.0, and more preferably less than 0.5. By setting the degree of yellowing (Δb) to the above range, it is possible to produce a hard-coated film that is difficult to yellow and has poor coating film deterioration even in the case of a mobile product for outdoor use. In the present invention, the degree of yellowing (Δb) represents 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 the value, the worse the deterioration of the coating film.

The hard coat film having a hard coat layer on one surface of the transparent support has been described as one embodiment of the hard coat film of the present invention. The present invention is not limited to the above-mentioned configuration, and also includes a hard-coated film having a hard coating layer on both sides of the transparent support, and a hard layer having an adhesive layer, a printing layer, and an evaporation layer on the non-hard-coating surface of the transparent support. Coating film.

In the case where the hard-coated film of the present invention is used for display screens of mobile products such as mobile phones and smart phones for outdoor use, it also has no yellowing because it has sufficient weather resistance. In addition, since the base material is excellent in adhesion, it can be used without peeling between the hard coat layer and the transparent support. In particular, the hard-coated film of the present invention does not deteriorate the hard-coat layer under a high-temperature and high-humidity environment, and also has excellent substrate adhesion in such an environment. Therefore, for example, when the production location of each component of a mobile product is different from the assembly location of a mobile product, it can also be used in a high temperature and humidity environment during the manufacture and transportation of various components. Especially in recent years, in order to cope with a high level of weather resistance, a large amount of ultraviolet absorbers and light stabilizers are tended to be added to the hard coating layer, and various problems have occurred. As a hard coating film with weather resistance that solves the above problems, The technology of the present invention is useful.

Hereinafter, the present invention will be specifically described based on examples, but the present invention is not limited to these examples.

<Constituent components of coating composition>

The details of each constituent used in the following examples and comparative examples are given 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., number of energy ray curable functional groups: 6, number of hydroxyl groups: 0, weight average molecular weight 563, number of energy ray curable functional groups (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-propenyloxypropyl methacrylate monomer (trade name: NK ESTER 701A, manufactured by Shin Nakamura Chemical Industry Co., Ltd., number of energy ray curable functional groups (E): 2, hydroxyl group Number: 1, weight average molecular weight 214)

A'3: polyethylene glycol # 1000 diacrylate monomer (trade name: NK ESTER A-1000, manufactured by Shin Nakamura Chemical Industry Co., Ltd., number of energy ray curable functional groups (E): 2, number of hydroxyl groups: 0, weight (Average molecular weight 1108)

A'4: methoxypolyethylene glycol # 400 acrylate monomer (trade name: NK ESTER AM-90G, manufactured by Shin Nakamura Chemical Industry Co., Ltd., number of energy ray curable functional groups (E): 1, number of hydroxyl groups: 0 (Weight average molecular weight 454)

(B) Ultraviolet absorbent

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

B'1: Non-energy-ray-curable benzotriazole-based ultraviolet absorber (trade name: (TINUVIN 928, made by BASF)

B'2: Non-energy-ray-curable benzophenone-based ultraviolet absorber (trade name: LS-907, manufactured by Fangyishe Oil Industry Co., Ltd.)

(C) (meth) acrylate oligomer (energy ray curable oligomer)

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

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

(D) Light stabilizer

(D) Ingredient: Hindered amine light stabilizer (trade name: TINUVIN 765, manufactured by BASF)

(E) Photopolymerization initiator

E1-1: bis (2,4,6-trimethylbenzylidene) -phenylphosphine oxide (trade name: Irgacure 819, manufactured by BASF)

E1-1: 2-dimethylamino-2- (4-methyl-benzyl) -1- (4-morpholin-4-yl-phenyl) -butane-1-one (trade name: Irgacure (379, made by BASF)

E2: 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinylpropan-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. Production of coating composition and hard coating film

(A) (meth) acrylate monomers, (B) ultraviolet absorbers, and (C) (meth) acrylates shown in Tables 1 to 5 were weighed according to the solid content ratio (parts by mass) shown in Table 1. Oligomer. The details of each constituent are as described above. Further, (D) 1 part by mass of a light stabilizer and (E-1) bis (2,4,6-trimethylbenzyl) -phenylphosphine oxide (commercial product) as a (E) photopolymerization initiator Name: Irgacure 819, manufactured by BASF) and (E-2) 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinylpropane-1-one (trade name: Irgacure 907 3, 4 parts by mass, and manufactured by BASF). In addition, about Example 4 to Example 14 shown in Table 2, the photoinitiator described in Table 2 was added in the mass ratio shown in Table 2. The above components were mixed with 75 parts by mass of methyl ethyl ketone (MEK) and 75 parts by mass of propylene glycol monomethyl ether (PGM), respectively, and stirred to obtain coating compositions of the examples and comparative examples (solid content: 43%). . Next, as a transparent support, the coating compositions of the examples and comparative examples were coated by a bar coating method on one surface of a polyethylene terephthalate film (trade name: COMOSHINE A4300, manufactured by Toyobo Co., Ltd.) with a thickness of 188 μm. After drying at 80 ° C. for 2 minutes, a high-pressure mercury lamp was irradiated at 300 mJ / cm ² and cured to form a hard coating layer having a film thickness of 6 μm, and hard coating films of each example and comparative example were obtained.

2. Evaluation

The obtained hard-coated films of the examples and comparative examples were measured or evaluated for the four items of coating film hardness, abrasion resistance, weather resistance, and substrate adhesion by the following methods. 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. 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 film hardness]

The pencil hardness of the hard-coated films of Examples and Comparative Examples was measured using a pencil scratch tester in accordance with JIS K5400. In detail, with the hard-coated surface of the hard-coated film as the upper side, set the pencil at an angle of 45 degrees, and rub 5mm with a load of 1000g from above, and record the hardness of the pencil without damage 4 or more times.

〔Abrasion resistance〕

<Initial Scratch Resistance>

As a steel wool resistance test, a steel wool of # 0000 was wrapped and wound around a 3 cm ² cylindrical jig, and the resultant was placed on the hard coating of the hard-coated film of the examples and comparative examples, and the load was 500 g. The number of times before the first occurrence of scratches was recorded as the initial scratch resistance evaluation value.

<Scratch resistance after moisture resistance test>

The hard-coated films of the Examples and Comparative Examples after the moisture resistance test described later were measured in the same manner as the initial steel wool test, and the number of times before the first scratch was used as the evaluation of the scratch resistance after the moisture resistance test. Value is recorded.

〔Weather resistance (△ b)〕

As a weather resistance test, the hard-coated films of Examples and Comparative Examples were irradiated with UVA340 lamps at 60 ° C. for 8 hours based on ASTM G-154 using a QUV ultraviolet fluorescent accelerator (manufactured by Q-LAB). Then, it was left to stand in a condensing environment at a room temperature of 50 ° C. for 4 hours in a dark room to condense each hard-coated film. With this as one cycle, 12 cycles were performed. Using a spectrophotometer (trade name: CM-5, manufactured by KONICA MINOLTA SENSING), the yellowness (Δb) after 12 cycles was measured and recorded as an evaluation value of weather resistance.

[Substrate Adhesiveness]

<Initial substrate adhesion>

As a substrate adhesion test, 100 hard cuts were made on the hard coats of the hard-coated films of the Examples and Comparative Examples based on the checkerboard method of JIS K5400. 100 grids with a gap of 1 mm were cut and pasted as specified in JIS Z1522. After peeling the cellophane adhesive tape, the number of coating films remaining on the transparent support was counted with the naked eye, and recorded as the initial substrate adhesion evaluation value.

<Adhesion of substrate after weather resistance test>

The hard-coated film after the weather resistance test was measured in the same manner as in the initial substrate adhesion test, and recorded as the evaluation value of the substrate adhesion after the weather resistance test.

<Adhesion of substrate after moisture resistance test>

As a moisture resistance test, after standing in an environment at a temperature of 60 ° C. and a relative humidity of 90% RH for 550 hours, it was measured in the same manner as the initial substrate adhesion test. Make a record.

Table 1 shows various characteristics evaluation results of the hard-coated films of Examples 1 to 3 and Comparative Examples 1 to 7.

It was found that the hardness and scratch resistance of the hard-coated film obtained from the coating composition of Comparative Example 1 using a high-hardness monomer (A2) containing no oligomer component and three energy ray-curable functional groups were good. However, the curing shrinkage of the coating composition of Comparative Example 1 was large, and the hard coat layer had a large warpage. In addition, the hard-coated film of Comparative Example 1 had low initial substrate adhesion, and after the weather resistance test and after the moisture resistance test, it was confirmed that the substrate further decreased significantly, and was not suitable for practical use. ratio In Comparative Example 1, it is considered that the curing shrinkage is large because it does not have an oligomer. It should be noted that the same curing shrinkage was confirmed even when A2 was changed and A1 was used. In addition, it was confirmed that the weather resistance of the hard-coated film of Comparative Example 1 was also insufficient. The reason is considered to be that the number of hydroxyl groups of A2 is 1, but since Comparative Example 1 does not contain an oligomer, the amount of hydroxyl groups in the entire coating composition is large, so unreacted hydroxyl groups remain after curing.

Although not shown in the table, a hard-coated film obtained from a coating composition containing 100 parts by mass of C1 as an oligomer component without a monomer component was confirmed to have good pencil hardness and abrasion resistance, but it was not possible to obtain sufficient Adhesion to the substrate.

On the other hand, it can be seen that Example 1 containing monomer component A1 and oligomer component C1, Example 2 containing monomer component A2 and oligomer component C1, and implementation of monomer component A1 and oligomer component C2. In Example 3, a hard-coated film having excellent coating film hardness, abrasion resistance, weather resistance, and substrate adhesion was obtained.

On the other hand, Comparative Example 2 containing monomer component A'1 (weight average molecular weight: 332, hydroxyl group: 2 and number of energy ray curable functional groups) and oligomer component C1 (mass average molecular weight: 4900). The hardness and abrasion resistance of the hard coating film obtained from the coating composition were lower than those of Examples 1 to 3. Furthermore, it was confirmed that the weather resistance was decreased, yellowing occurred after ultraviolet irradiation, and the adhesion to the substrate was decreased after the weather resistance test and the humidity resistance test. Since A'1 has two hydroxyl groups, it is considered that the above-mentioned degradation of properties is due to the influence of residual hydroxyl groups and / or water adsorbed on the residual hydroxyl groups.

A coating composition of Comparative Example 3 containing monomer component A'2 (weight average molecular weight: 214, hydroxyl group: 1 and number of energy ray curable functional groups) and oligomer component C1 (weight average molecular weight: 4900) Compared with Examples 1 to 3, the obtained hard-coated films had reduced hardness and abrasion resistance. This is considered to be because the weight average molecular weight of A'2 was small and was 214. Furthermore, the hardness of Comparative Example 3 was confirmed. The weather resistance of the coating film is reduced, yellowing occurs after ultraviolet irradiation, and the adhesion to the substrate is decreased after the weather resistance test and the humidity resistance test. It is considered that the number of hydroxyl groups of A'2 is one, but the molecular weight is small. Therefore, the number of hydroxyl groups in the entire coating composition is large, and excess hydroxyl groups remain after curing. Therefore, residual hydroxyl groups and / or water adsorbed to the remaining hydroxyl groups The effect degrades this characteristic.

A 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) and oligomer component C1 (weight average molecular weight: 4900) Compared with Examples 1 to 3, the obtained hard-coated films had reduced hardness and abrasion resistance. It is considered that this is because the weight average molecular weight of A'3 is 1108, so that the monomer component A'3 does not enter the gap between the oligomer components, and the crosslinking density does not increase. Furthermore, it was confirmed that the hard-coated film of Comparative Example 4 had a reduced adhesion to the substrate after the weather resistance test and the moisture resistance test. In Comparative Example 4, since the molecular weight of the monomer component was large, the crosslinking density did not increase, and therefore it was difficult to bond to the surface of the substrate. Therefore, peeling easily occurred under the influence of ultraviolet radiation and humidity.

A 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) and oligomer component C1 (weight average molecular weight: 4900). Compared with Examples 1 to 3, the obtained hard-coated films had significantly lower hardness and abrasion resistance. This is considered to be because the number of the energy ray-curable functional groups of A'4 was one, and the crosslinking reaction did not sufficiently proceed. Furthermore, it was confirmed that the weather resistance of the hard-coated film of Comparative Example 5 and the initial substrate adhesion were low, and the adhesion to the substrate was further decreased 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, the crosslinking reaction does not sufficiently proceed, and the initial adhesiveness with the substrate is low. In addition, it is considered that the low crosslinking density is liable to cause deterioration in an ultraviolet ray irradiation and high humidity environment due to a decrease in weatherability and adhesion of the substrate after various tests.

B1, an ultraviolet absorbent that changes the energy ray curability, and Comparative Examples 6 and 7 that use non-energy ray curable ultraviolet absorbers. Compared with the examples, the hardness and abrasion resistance are lower. The weather resistance test and humidity resistance After the test, the adhesiveness of the substrate became low.

From the above results, it can be seen that an energy-ray-curable oligomer having a predetermined molecular weight, an energy-ray-curable oligomer having a predetermined molecular weight, and an energy-ray-curable functional group are included. The hard-coated film obtained from the coating composition of the present invention, which is an ultraviolet absorbent, can have excellent scratch resistance, weather resistance, and substrate adhesion.

Table 2 shows the evaluation results of the substrate adhesion of the hard-coated films of Examples 4 to 14.

In Examples 4 to 14, the types and blending amounts of (A) (meth) acrylate monomers, (B) ultraviolet absorbers, (C) acrylate oligomers, and (D) light stabilizers were as in Example 1. Similarly, the type and ratio of the (E) photopolymerizing agent are changed. In Example 4, as the photopolymerizing agent, only 7 parts by mass of E1 was added. In Example 9, only 7 parts by mass of E2 was added. In Examples 1 and 5 to 8, the ratio of E1 and E2 was changed, which was 7 as a whole. Added by mass. Here, it can be seen that, compared with Examples 4 and 9 containing either E1 and E2, the substrates of Examples 1, 5 to 8 containing E1 and E2 are in close contact with each other after the weather resistance test and after the humidity resistance test. Sexual improvement. In particular, in Examples 1, 5 to 6, the adhesiveness of the substrate after the humidity resistance test was greatly improved.

In addition, in Example 10, two types of the photopolymerization initiator E1 whose 0.01-mass% methanol solution or acetonitrile solution had a maximum absorbance of 0.1 or more in a wavelength range of 340 to 400 nm were added, but no image was confirmed and E1 was used in combination. The effect of reducing the adhesion of the substrate after the weather resistance test and after the humidity resistance test as in the above-mentioned Example of E2 is greatly suppressed. and then, In Example 11, the maximum absorbance of 0.01% by mass methanol solution or acetonitrile solution in the wavelength range of 340nm to 400nm is 0.1 or more, and the maximum absorbance of 0.001% by mass methanol solution in the wavelength range of 220nm to 280nm One type is added for a photopolymerization initiator of 0.1 or more. However, the effect of significantly reducing the decrease in the adhesion of the substrate after the weather resistance test and after the humidity resistance test as in the examples using E1 and E2 in combination was not obtained.

In addition, in Examples 12 to 14, the types and ratios of the photopolymerization initiators E1 and E2 (E1: E2 = 3: 4) were the same as in Example 1, and the total amount of the photopolymerization initiators E1 and E2 was changed. Quality ratio. The mass ratios of the total amounts of E1 and E2 of each of Example 12, Example 1, Example 13 and Example 14 were 3.5, 7, 10.5, and 14. In the examples, it was confirmed that excellent substrate adhesion was maintained even after the weather resistance test and after the moisture resistance test.

From the above results, it was confirmed that it is effective to use two types of photopolymerizing agents having a predetermined absorbance in a predetermined wavelength range to improve the adhesion to the substrate.

Table 3 shows various evaluation results of the hard-coated films of Examples 15-18.

In Examples 12 to 15, (A) (meth) acrylate monomer, (B) ultraviolet absorber, (C) (meth) acrylate oligomer, (D) light stabilizer, (E) light The types of recombination agents and the blending amounts of (B) ultraviolet absorber, (D) light stabilizer, and (E) light recombination agent are the same as in Example 1. (A) (meth) acrylate monomer and (C) The proportion of (meth) acrylate oligomer.

Here, because the monomer (A1) having a high hardness is used, as the amount of the monomer increases, pencil hardness and abrasion resistance increase. In addition, it was found that excellent weather resistance and substrate adhesion were obtained in any of the examples. In particular, Example 16, Example 1, and Example 17 in which the content ratio of the component (A) to the component (C) was in a range of 3:97 to 50:50 were confirmed. After the moisture resistance test, the adhesiveness of the substrate was greatly improved.

Table 4 shows various evaluation results of the hard-coated films of Examples 19-22.

In Examples 19 and 22, the thickness of the hard coat layer was changed as shown in Table 4, and a hard coat film was produced and evaluated in the same manner as in Example 1. By increasing the thickness of the hard coat layer by 3 μm, 6 μm, and 15 μm, it was confirmed that the scratch resistance was further improved. However, it was found that sufficient scratch resistance, substrate adhesion, and weather resistance were obtained in any of the examples.

In Examples 21 and 22, the addition amount of the ultraviolet absorber (B1) was changed as shown in Table 4, and a hard coat film was produced and evaluated in the same manner as in Example 1. It can be seen that in any of the examples, sufficient scratch resistance, substrate adhesion, and weather resistance were obtained.

Table 5 shows various evaluation results of the hard-coated films of Examples 23 to 25.

In Example 23 and Example 25, a hard coat film was produced and evaluated in the same manner as in Example 1 except that the light stabilizer (D) added to the coating composition was changed as shown in Table 5. It can be seen that sufficient abrasion resistance, weather resistance and Substrate adhesion.

Claims (8)

A coating composition comprising: (A) an energy ray curable (meth) acrylic acid having a weight average molecular weight of 250 or more and 1,000 or less, an energy ray curable functional group of 2 or more and 9 or less, and a hydroxyl number of 1 or less Ester monomers; (B) an ultraviolet ray absorbent containing an energy ray curable functional group; and (C) an energy ray curable oligomer having a weight average molecular weight of 1500 to 20,000, wherein the component (A) and the component (C) The mass ratio of the component ((A) component: (C) component) is 3:97 to 50:50. The coating composition according to item 1 of the scope of patent application, further comprising: (E1) 0.01% by mass of a photopolymerization initiator having a maximum absorbance of 0.1 or more in a wavelength range of 340nm to 400nm; and (E2) 0.001 A photopolymerization initiator having a maximum absorbance in a wavelength range of 220 nm to 280 nm of 0.1% by mass or more, wherein the photopolymerization initiator is methanol. The coating composition according to item 1 of the scope of patent application, further comprising: (E1) 0.01% by mass of a photopolymerization initiator having a maximum absorbance of 0.1 or more in a wavelength range of 340nm to 400nm; and (E2) 0.001 A mass polymerization initiator having a maximum absorbance in a wavelength range of 220 nm to 280 nm of 0.1 or more, wherein the photo polymerization initiator is acetonitrile. The coating composition according to items 1 to 3 of the scope of the patent application, wherein the maximum value of the absorbance of the dichloromethane solution of the component (B) 0.0619 mmol / l in the wavelength range of 280 nm to 370 nm is 0.6 or more Absorbent. A hard coating film characterized in that at least one side of a transparent support has a hard coating obtained from the coating composition described in any one of claims 1 to 3 of the scope of patent application, wherein the hard coating and The adhesiveness of the substrate of the transparent support is 90/100 or more based on JIS K5400. The hard coating film according to item 5 of the scope of patent application, wherein the thickness of the hard coating layer is 0.5 μm or more and 20 μm or less. The coating composition according to item 5 of the scope of patent application, wherein the hard coat layer and the transparent support body are subjected to a humidity resistance test after being left for 550 hours in an environment having a temperature of 60 ° C and a relative humidity of 90% RH. The adhesiveness of the substrate is 90/100 or more based on JIS K5400. The coating composition according to item 5 of the scope of patent application, wherein the yellowness (Δb) after 12 cycles of the weather resistance test specified in ASTM G-154 is less than 1.