JP5935133B2 - Hard coat film - Google Patents

Description

The present invention relates to a hard coat film, which has antibacterial properties, high transparency, and excellent weather resistance.

In recent years, membrane switches, touch panels, and the like are generally used as input devices such as information terminals, and hard coat films are used as surface members of such input devices. In many cases, a hard coat film is attached to the outermost surface of a mobile device such as a mobile phone or a smartphone through an adhesive layer or an adsorption layer for the purpose of preventing scratches.
Such a hard coat film is used for a part directly touched by an operator, but if bacteria or the like are propagated on the surface thereof, there is a risk of being infected with a disease. In recent years, nosocomial infections due to MRSA and the like have become a problem, and in order to reduce the risk of disease infection by such bacteria, it is required to prevent the growth of bacteria on the surface of the input device.

Therefore, conventionally, a resin in which an antibacterial agent is mixed and formed into a film (Patent Document 1) has been proposed.

However, when it is used as the surface of an input device that is used by various unspecified human beings in various ways, a resin molded with an antibacterial agent is molded into a film and has poor scratch resistance and easily scratches. There was a drawback that the surface appearance was impaired. In addition, when the antibacterial agent is uniformly present throughout the film, the antibacterial agent present inside the film does not act effectively, so that the desired antibacterial effect cannot be obtained unless the content is increased.
In addition, (Patent Document 2) proposes a hard coat film provided with a curable resin layer containing an antibacterial agent.
However, in the case of a hard coat film containing a large antibacterial fine particle having a particle size of 1 μm or more as an antibacterial agent in the curable resin layer, not only the transparency is deteriorated but also the hard coat layer is deteriorated in weather resistance. There was a problem that the adhesiveness between the substrate and the substrate was lowered.
In particular, in a hard coat film in which inorganic oxide particles or resin particles are added to the hard coat layer in order to impart antiglare properties, the adhesion to the base film is often low, due to a decrease in weather resistance. The decrease in the adhesion between the hard coat layer and the substrate was a particular problem.

ACT 7-9952 JP-A-9-1111020

Therefore, the problem to be solved by the present invention is to provide a hard coat film having antibacterial properties, high transparency and excellent weather resistance.

1st invention of this invention is the hard coat film which provided the hard-coat layer in the at least one surface of the base material, The said hard-coat layer contains the compound (b) antibacterial component which polymerizes by (a) ionizing radiation after particle size was coated and dried on a substrate a coating liquid containing at least an antimicrobial particles of 0.005Myuemu～0.8Myuemu, Ri hard coat layer der obtained by curing by irradiation of ionizing radiation, wherein ( b) The antibacterial fine particles are inorganic oxide fine particles covered with a coating layer containing an antibacterial metal component in silica-alumina composite oxide, and the content of the (b) antibacterial fine particles is in the solid content of the hard coat layer. a 0.04 weight% of a hard coat film the hard coat layer is characterized that you containing 10 to 20 wt% of silica particles in the hard coat layer solids.
A second invention is the hard coat film according to the first invention, wherein the average particle diameter of the antibacterial fine particles (b) is 0.005 μm to 0.05 μm.

As in the first invention, the hard coat layer contains a compound that is polymerized by ionizing radiation, and antibacterial fine particles having an average particle diameter of 0.005 μm to 0.8 μm containing an antibacterial component. A hard coat film excellent in durability against a decrease in adhesion strength, that is, weather resistance and antibacterial properties can be obtained.

The base material of the hard coat film used in the present invention is not particularly limited as long as it is a film made of various plastics. Examples include films made of polyolefin, polyester, polyamide, polycarbonate, fluororesin, polyphenylene oxide, polyimide, polyamideimide, acrylic resin, polyvinyl chloride, polyvinylidene chloride, polyacrylonitrile, cellulose resin, etc. It is not limited to. A polyester film is preferably used from the viewpoints of handleability, improvement of adhesive strength with the adhesive layer, and cost. The thickness of the substrate may be appropriately selected according to the use, but usually a thickness in the range of 4 to 400 μm is used.

The coating liquid for forming the hard coat layer of the present invention contains a compound that is polymerized by ionizing radiation. The compound that is polymerized by ionizing radiation is preferably a compound having a (meth) acryloyl group that forms a radical polymerization reaction or a compound that forms a cationic polymerization reaction. The compound having a (meth) acryloyl group means a compound having one or more (meth) acryloyl groups in the molecule, and may be a monomer, an oligomer, or both.

In the present invention, the acryloyl group and the methacryloyl group are collectively referred to as a (meth) acryloyl group. That is, the compound having a (meth) acryloyl group may be a compound having only an acryloyl group, or a compound having only a methacryloyl group, and having both an acryloyl group and a methacryloyl group. It may be. The same applies to (meth) acrylates and (meth) acrylic esters described below.

Examples of the compound having a (meth) acryloyl group according to the present invention include monomers or oligomers of polyfunctional (meth) acrylates and monofunctional (meth) acrylates described below.

Multifunctional (meth) acrylates include trimethylolpropane tri (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) Acrylate, dipentaerythritol hexa (meth) acrylate, glycerin tri (meth) acrylate, tris (2-hydroxyethyl) isocyanurate tri (meth) acrylate, ethylene glycol di (meth) acrylate, 1,3-butanediol di ( (Meth) acrylate, 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, die Renglycol di (meth) acrylate, triethylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, bis (2-hydroxyethyl) isocyanurate di (meth) acrylate, and ethylene oxide to these starting alcohols Or propylene oxide adduct poly (meth) acrylates, oligoester (meth) acrylates having two or more (meth) acryloyl groups in the molecule, oligoether (meth) acrylates, oligourethane (meth) acrylates, And oligoepoxy (meth) acrylates.

Monofunctional (meth) acrylates include methyl (meth) acrylate, ethyl (meth) acrylate, acrylonitrile, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 3-chloro-2-hydroxypropyl (meth) acrylate, glycerin mono (meth) acrylate, glycidyl (meth) acrylate, lauryl (meth) acrylate, cyclohexyl (meth) acrylate, isobornyl (meth) acrylate, tricyclodecanyl (meth) ) Acrylate, dicyclopentenyl (meth) acrylate, n-butyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, octyl (meth) acrylate, (Meth) acrylate, decyl (meth) acrylate, isodecyl (meth) acrylate, dodecyl (meth) acrylate, n-stearyl (meth) acrylate, benzyl (meth) acrylate, phenol ethylene oxide modified (n = 2) (meth) Half of phthalic acid derivatives such as acrylate, nonylphenol propylene oxide modified (n = 2.5) (meth) acrylate, 2- (meth) acryloyloxyethyl acid phosphate, 2- (meth) acryloyloxy-2-hydroxypropyl phthalate ( (Meth) acrylate, furfuryl (meth) acrylate, carbitol (meth) acrylate, benzyl (meth) acrylate, butoxyethyl (meth) acrylate, allyl (meth) acrylate 2-acryloyl Carboxymethyl ethyl acid phosphate monoesters, cyclohexanedimethanol monoacrylate, 4-hydroxybutyl acrylate, 4-glycidyloxy-butyl acrylate, diacetone acrylamide, N- vinylformamide, acryloyl morpholine, phenoxy group-containing acrylate.

These compounds having a (meth) acryloyl group may be used alone or in combination of two or more.

On the other hand, an epoxy resin is usually used as a compound that forms cationic polymerization. Examples of the epoxy resins include compounds obtained by epoxidizing polyphenols such as bisphenol resins and novolac resins with epichlorohydrin, etc., and compounds obtained by oxidizing a linear olefin compound or a cyclic olefin compound with a peroxide or the like. Etc.

Examples of the photopolymerization initiator used in the ionizing radiation polymerization reaction include radical polymerization type compounds such as benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin-n-butyl ether, benzoin isobutyl ether, and acetophenone. Dimethylaminoacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-hydroxycyclohexyl phenyl ketone 2-methyl-1- [4- (methylthio) phenyl] -2-morpholino-propan-1-one, 4- (2-hydroxyethoxy) phenyl-2 (hydroxy-2-propyl) ketone, benzophenone, p- Phenylbenzophenone, 4,4′-diethylaminobenzophenone, dichlorobenzophenone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-tert-butylanthraquinone, 2-aminoanthraquinone, 2-methylthioxanthone, 2-ethylthioxanthone, 2-chlorothioxanthone 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, benzyl dimethyl ketal, acetophenone dimethyl ketal, p-dimethylamine benzoate, and the like. Examples of photopolymerization initiators for cationic polymerization type compounds include oniums such as aromatic sulfonium ions, aromatic oxosulfonium ions, aromatic iodonium ions, tetrafluoroborate, hexafluorophosphate, hexafluoroantimonate, hexa The compound which consists of anions, such as fluoroarsenate, is mentioned. These may be used alone or in combination of two or more, and the blending amount is usually selected in the range of 0.2 to 10 parts by mass with respect to 100 parts by mass of the polymerizable compound. It is.

In addition to the ionizing radiation curable compound, a thermoplastic polymer can be added as long as the hard coat property is not significantly impaired. Examples of the thermoplastic polymer include acrylic resins, vinyl acetate resins, epoxy resins, polyester resins, polycarbonate resins, butyral resins, gelatin, cellulose resins, polyamide resins, vinyl chloride resins, urethane resins. Examples thereof include resins.

In addition, antifoaming agents, coating properties improvers, thickeners, surfactants, organic lubricants, antioxidants, UV absorbers, foaming agents, dyes, pigments, antistatic agents, etc. You may do it.

When the antiglare property is imparted to the hard coat film itself, organic fine particles or inorganic fine particles may be contained. These may be used alone or in combination of two or more. Here, as the inorganic fine particles for imparting antiglare properties, silica particles are suitable because high antiglare properties can be obtained at low cost. The content of silica particles is preferably 5% by weight to 30% by weight, and more preferably 10% by weight to 20% by weight in the hard coat solid content. If the content of silica particles is less than 5% by weight in the solid content of the hard coat, it is difficult to obtain sufficient antiglare properties, and if it is more than 30% by weight, the adhesion with the base film may be inferior, It is not preferable.

The coating liquid for forming the hard coat layer of the present invention contains antibacterial fine particles having an average particle diameter of 0.005 μm to 0.8 μm containing an antibacterial component. Thereby, a hard coat film excellent in weather resistance and antibacterial properties can be obtained in the hard coat layer.

This is because when the average particle diameter of the antibacterial fine particles is less than 0.005 μm, the formation of a coating layer containing an antibacterial metal component on the surface of the antibacterial fine particles becomes insufficient, and sufficient antibacterial properties cannot be obtained.
On the other hand, when the average particle diameter of the antibacterial fine particles is larger than 0.8 μm, not only the transparency of the obtained hard coat film is inferior, but also the hard coat layer and the substrate are deteriorated due to the deterioration of the weather resistance of the hard coat layer. This is not preferable because the adhesion to the resin is lowered. In addition, since the hard coat film excellent in the weather resistance is obtained if the average particle diameter of the antibacterial fine particles is 0.05 μm or less, it is particularly preferable.

The antibacterial fine particles of the present invention are desirably inorganic oxide fine particles containing an antibacterial metal component. When antibacterial fine particles containing organic antibacterial components as an antibacterial component or organic antibacterial components themselves are directly included in the hard coat layer, the organic antibacterial component bleeds out and exhibits antibacterial performance. This is because the component is not preferable because it has a problem of reducing the adhesion between the base material and the hard coat layer. Furthermore, when an organic antibacterial component is contained, it itself is deteriorated by light, and the weather resistance may be lowered.

Various inorganic oxides can be used as the inorganic oxide fine particles, such as TiO ₂ , ZrO ₂ , SiO ₂ , Al ₂ O ₃ , Fe ₂ O ₃ , Sb ₂ O ₃ , WO ₃ and CeO ₂ . Single inorganic oxide, SiO ₂ · Al ₂ O ₃ , SiO ₂ · TiO ₂ , SiO ₂ · ZrO ₂ , Al ₂ O ₃ · TiO ₂ , Al ₂ O ₃ · CeO ₂ , TiO ₂ · CeO ₂ , A composite oxide such as TiO ₂ · ZrO ₂ , SiO ₂ · TiO ₂ · ZrO ₂ , SiO ₂ · TiO ₂ · CeO ₂ can be given. In particular, TiO _2, SiO _2, and Al ₂ O ₃ is preferably used.

As the antibacterial inorganic oxide fine particles containing an antibacterial metal component in the present invention, inorganic oxide fine particles covered with a coating layer containing an antibacterial metal component on a silica-alumina composite oxide are suitable.

Moreover, as a compound which forms the coating layer containing the antibacterial metal component which coat | covers the surface of the above-mentioned inorganic oxide fine particle, the inorganic compound which has a negative charge is used. Examples of the inorganic compound include silica-alumina, titania-silica, and the like. In particular, since the silica-alumina composite oxide can contain a large amount of antibacterial metal components, the antibacterial agent can be used with a smaller amount of antibacterial agent. Since performance is obtained, it is particularly preferable for maintaining weather resistance and transparency.

As the antibacterial metal component in the present invention, an antibacterial metal component usually used as an inorganic antibacterial agent is suitable, and specifically, silver, copper, zinc, lead, tin, bismuth, cadmium, chromium, mercury , Nickel, cobalt and the like. In particular, at least one metal component selected from silver, copper, and zinc also has anti-odor, anti-bacterial, and anti-algal properties in addition to antibacterial properties, and is preferable from the viewpoint of discoloration and safety to the human body .

The content of the antibacterial fine particles contained in the hard coat layer is preferably 0.04 wt% to 1 wt% with respect to the hard coat layer. Less than 0.04% by weight is not preferable because sufficient antibacterial performance may not be obtained. On the other hand, if it exceeds 1% by weight, not only is the weather resistance lowered and sufficient adhesion between the substrate and the hard coat layer cannot be obtained, but the transparency may be lowered, which is not preferable.

The thickness of the hard coat layer is 0.5 μm or more and 20 μm or less, preferably 1 μm or more and 10 μm or less. If it is less than 0.5 μm, sufficient hard coat properties cannot be obtained, and the coating film is easily damaged. On the other hand, if it exceeds 20 μm, the cost will increase. Moreover, when a hard coat is applied on both sides, it is preferable to suppress the difference in film thickness between the two layers within 30%. If this range is exceeded, the curl of the hard coat film becomes large, which may adversely affect the handleability of the next process transfer and may adversely affect the touch panel function when the touch panel is assembled.

The present invention will be described more specifically with reference to the following examples. In addition, this invention is not limited by these Examples.

[Method for producing antibacterial fine particles A]
First, a caustic soda aqueous solution is added to a colloidal solution of silica-alumina composite oxide fine particles to adjust the pH to a range of 10 to 11, and then heated to a temperature of 60 to 98 ° C. Next, a predetermined amount of sodium aluminate aqueous solution and a predetermined amount of water glass aqueous solution are simultaneously added to the colloidal solution while stirring and heated and aged for 5 hours at a temperature of 60 to 98 ° C. Silica-alumina hydrate is deposited on the substrate. Thereafter, the alkali was removed by performing a dealkalization treatment using a cation exchange resin to obtain a colloidal solution of inorganic oxide fine particles coated with a silica-alumina composite oxide.
On the other hand, 0.08 g of silver oxide (special grade reagent) is suspended in about 20 g of water, then 15% by weight of ammonia water is added until the silver oxide is dissolved, and the total concentration of silver is 0.5% by weight. In this manner, water was added to prepare an aqueous silver ammine complex salt solution.

This silver ammine complex salt aqueous solution was added to the colloidal solution and stirred sufficiently to prepare a silica / alumina composite oxide colloidal solution covered with a coating layer containing an antibacterial metal component of silver. Next, this colloidal solution was concentrated with an ultrafiltration membrane, and further substituted with isopropanol to prepare a dispersion of 1.5% by weight of antibacterial fine particles A. When the obtained antibacterial fine particles A were observed with a scanning electron microscope, the average particle diameter of the antibacterial fine particles was 0.015 μm.

Example 1
A hard coat resin solution was prepared by dissolving 29% by weight of dipentaerythritol hexaacrylate and 1% by weight of 1-hydroxycyclohexyl phenyl ketone in 70% by weight of methyl ethyl ketone. Next, a silica dispersion having a solid content of 30% by weight in which silica having an average particle diameter of 2 μm is dispersed in methyl ethyl ketone is mixed so as to be 14% by weight of the hard coat solid content. The dispersion was mixed so that the solid content ratio of the hard coat layer was 0.2% to obtain a hard coat coating solution.
The hard coat coating solution prepared above is applied to and dried on one side of 100 μm thick optical PET, and then irradiated with ultraviolet light with an integrated light quantity of 500 mJ / cm ² to cure the coating film to form a hard coat layer with a thickness of 2 μm. Thus, a hard coat film of Example 1 was produced.

(Examples 2 to 6)
Examples 2 to 6 were prepared in the same manner as in Example 1 except that the mixing ratio of the dispersion of antibacterial fine particles A in Example 1 was set to each weight% shown in Table 1 as the solid content mixing ratio of the hard coat layer. A hard coat film was prepared.

(Example 7)
A hard coat film was produced in the same manner as in Example 1 except that antibacterial fine particles in which silver was supported on zinc calcium phosphate having an average particle diameter of 0.8 μm were used as the antibacterial agent.

(Example 8)
A hard coat film was produced in the same manner as in Example 1 except that the silica dispersion was not mixed.

(Comparative Example 1)
A hard coat film of Comparative Example 1 was produced in the same manner as in Example 1 except that the antibacterial agent was not mixed.

(Comparative Example 2)
A hard coat film was produced in the same manner as in Example 7 except that antibacterial fine particles in which silver was supported on zinc calcium phosphate having an average particle diameter of 1.0 μm were used as the antibacterial agent.

(Comparative Example 3)
A hard coat film was produced in the same manner as in Example 7 except that antibacterial fine particles in which silver was supported on zeolite having an average particle diameter of 1.0 μm were used as the antibacterial agent.

(Comparative Example 4)
A hard coat film was prepared in the same manner as in Example 7, except that a quaternary ammonium salt organic compound (Amorden PPC manufactured by Daiwa Chemical) was used as the antibacterial agent.

The following evaluation was performed about the hard coat film produced as mentioned above. Evaluation items and evaluation criteria are as follows.

1. Among antibacterial tests based on JIS-Z2801: 2010, according to the film adhesion method, a specimen sample (50x50mm) and a medium (1/500 times nutrient) are prepared, and Escherichia coli IFO 3972 and yellow are used as test bacteria. Staphylococcus aureuse IFO 12732 was used. For the test, inoculate 0.4 mL of the bacterial suspension on the specimen sample, cover it with a coating film, cover it, leave it at 35 ± 1 ° C and relative humidity of 90% or more for 24 hours, and then count the number of viable bacteria. Was measured. 24 hours after the viable cell count of logarithm of not containing an antibacterial agent antibacterial no unprocessed test piece (U _t), and 24 hours after the viable cell count of the logarithm of the test sample (A _t) Measure and
Antibacterial activity value R = Log. Evaluation was performed by U _t -LogA _t .

2. Total light transmittance It measured based on JIS-K7361-1: 1997 using Nippon Denshoku Industries haze meter NDH2000. In addition, light was incident from the hard coat layer surface side and measured.

3. Haze It measured based on JIS-K7105: 1981 using Nippon Denshoku Industries haze meter NDH2000. In addition, light was incident from the hard coat layer surface side and measured.

3. Weather resistance After irradiating light with a carbon arc fade meter manufactured by Suga Test Instruments Co., Ltd. for 300 hours, the adhesion of the hard coat layer to the substrate was measured according to the cross-cut method of JIS-K5600.
○: Hard coat layer is not peeled off and adhesion is good. ×: Hard coat layer is peeled off, resulting in poor adhesion.

4). Scratch-resistant steel wool (# 0000) was subjected to a load of 500 gf / cm ² , and the hard coat layer was reciprocated 10 times in 14 seconds at a stroke width of 30 mm, and then the hard coat layer was evaluated for scratches. did. The evaluation criteria are as follows.
○: Scars are not visible at all ×: Scars are clearly visible

The measurement results and evaluation results are summarized in Table 1.

A：シリカ‐アルミナ複合酸化物に銀成分を含有する被覆層で覆われた無機酸化物微粒子
B：リン酸亜鉛カルシウムの銀担持物 平均粒径０．８μm
C：リン酸亜鉛カルシウムの銀担持物 平均粒径１．０μm
D：ゼオライトの銀担持物 平均粒径１．０μm
E：４級アンモニウム塩有機化合物 アモルデンPPC

A: Inorganic oxide fine particles covered with a coating layer containing a silver component in silica-alumina composite oxide
B: Silver carrier of zinc calcium phosphate Average particle size 0.8μm
C: Silver supported material of zinc calcium phosphate Average particle size: 1.0 μm
D: Silver support of zeolite Average particle size 1.0 μm
E: Quaternary ammonium salt organic compound Amorden PPC

Claims (2)

In the hard coat film provided with a hard coat layer on at least one surface of the substrate, the hard coat layer (a) a compound polymerized by ionizing radiation (b) an average particle size containing an antibacterial component is 0.005 μm to 0 after the coating liquid was coated and dried on a substrate containing at least an antimicrobial particles of .8Myuemu, Ri hard coat layer der obtained by curing by irradiation of ionizing radiation, wherein (b) antimicrobial particles silica - Inorganic oxide fine particles covered with a coating layer containing an antibacterial metal component in an alumina composite oxide, and the content of (b) antibacterial fine particles is 0.04 to 1% by weight in the solid content of the hard coat layer , and the hard coat film the hard coat layer is characterized that you containing 10 to 20 wt% of silica particles in the hard coat layer solids. The average particle diameter of said (b) antibacterial microparticles | fine-particles is 0.005 micrometer-0.05 micrometer, The hard coat film of Claim 1 characterized by the above-mentioned.