WO2017150421A1

WO2017150421A1 - Laminated film

Info

Publication number: WO2017150421A1
Application number: PCT/JP2017/007379
Authority: WO
Inventors: 祐七島; 達矢泉; 幹広樫尾; 宮田　壮
Original assignee: リンテック株式会社
Priority date: 2016-03-02
Filing date: 2017-02-27
Publication date: 2017-09-08
Also published as: KR20180120189A; JP6937739B2; TW201803944A; CN108778732A; JPWO2017150421A1; CN108778732B; KR102618670B1; TWI730055B

Abstract

The laminated film according to the present invention has a base layer and a hard coat layer, and is characterized in that the hard coat layer is formed using a hard coat agent containing components (A), (B), and (C), namely, (A) an organic silicon compound having a reactive functional group and a hydrolyzable group, (B) a polythiol compound, and (C) an inorganic filler having a reactive functional group, and that the measurement of the Young's modulus of the surface of the hard coat layer using an atomic-force microscope shows that regions where the Young's modulus is 1-5 GPa constitute a continuous structure, and regions where the Young's modulus is 6-10 GPa are isolated and distributed. The laminated film according to the present invention has a hard coat layer which has high hardness and excellent scratch resistance and flex resistance.

Description

Laminated film

The present invention relates to a laminated film having a hard coat layer having high hardness and excellent scratch resistance and flex resistance.

In recent years, display devices such as various displays have a touch panel and are increasingly used as data input devices.
When using such a touch panel, a pen or a finger is usually brought into contact with the surface of the touch panel. Therefore, the surface of the touch panel is required not to be damaged even if contact with a pen or a finger is repeated.
For this reason, conventionally, providing the hard-coat layer in the resin film which comprises a touchscreen has been performed.

For example, Patent Document 1 describes a resin composition for forming a transparent coating layer containing an organosilicon compound having a reactive functional group and a polythiol compound, and a method for forming a transparent coating using this resin composition. Has been. This document also describes that a transparent film formed using the resin composition is excellent in flexibility, hardness, scratch resistance, and wear resistance.

International Publication No. 2010/103944 Pamphlet

As described above, Patent Document 1 describes that the transparent film is excellent in flexibility, hardness, scratch resistance, wear resistance, and the like.
However, in order to form such a transparent film, it is necessary to sufficiently cure the resin composition, and depending on the curing conditions, it may not be possible to form a transparent film having the desired performance.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a laminated film having a hard coat layer having high hardness and excellent scratch resistance and flex resistance.

In order to solve the above-mentioned problems, the present inventors diligently studied the hard coat layer. As a result, by using a hard coat agent containing an organic silicon compound having a reactive functional group and a hydrolyzable group, a polythiol compound, and an inorganic filler having a reactive functional group, the hardness is high and the scratch resistance is high. It was found that a hard coat layer having excellent resistance can be efficiently formed. Furthermore, when an inorganic filler is added to the hard coat layer, the bend resistance of the hard coat layer may be reduced. However, by controlling the dispersion state of the inorganic filler in the hard coat layer, the decrease in the bend resistance is suppressed. I knew it could be.
The present invention has been made based on these findings.

Thus, according to the present invention, the following laminated film (1) is provided.
(1) A laminated film having a base material layer and a hard coat layer,
The hard coat layer is formed using a hard coat agent containing the following component (A), component (B), and component (C), and the hard coat layer is formed using an atomic force microscope. When the Young's modulus of the surface is measured, a region having a Young's modulus of 1 to 5 GPa constitutes a continuous structure, and a region having a Young's modulus of 6 to 10 GPa is isolated and dispersed.
(A) Component: Organosilicon compound having reactive functional group and hydrolyzable group (B) Component: Polythiol compound (C) Component: Inorganic filler having reactive functional group

According to the present invention, a laminated film having a hard coat layer having high hardness and excellent scratch resistance and flex resistance is provided.

2 is a Young's modulus mapping image of the laminated film (1) obtained in Example 1. It is a Young's modulus mapping image of the laminated film (2) obtained in Comparative Example 1. It is a Young's modulus mapping image of the laminated film (3) obtained in Comparative Example 2. It is a Young's modulus mapping image of the laminated film (4) obtained in Comparative Example 3. It is a Young's modulus mapping image of the laminated film (5) obtained in Comparative Example 4.

The laminated film of the present invention is a laminated film having a base layer and a hard coat layer, and the hard coat layer contains the following (A) component, (B) component, and (C) component. When the Young's modulus of the surface of the hard coat layer is measured using an atomic force microscope, a region having a Young's modulus of 1 to 5 GPa constitutes a continuous structure. A region having a Young's modulus of 6 to 10 GPa is isolated and dispersed.
(A) Component: Organosilicon compound having reactive functional group and hydrolyzable group (B) Component: Polythiol compound (C) Component: Inorganic filler having reactive functional group

The base material layer which comprises the laminated | multilayer film of this invention is used in order to hold | maintain a hard-coat layer.
The kind of base material layer is not specifically limited. For example, a synthetic resin film can be used as the base material layer.
Examples of synthetic resin films include polyethylene, polypropylene, polyvinyl chloride, polyvinylidene chloride, ethylene-vinyl acetate copolymer, ethylene-vinyl alcohol copolymer, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polymethacrylic acid. Examples of the film include methyl, polymethyl acrylate, polyethyl methacrylate, polystyrene, cellulose triacetate, cellophane, and polycarbonate.

In the present invention, a primer layer may be provided on at least one surface of the base material layer. The primer layer is not particularly limited as long as it has good adhesion to the hard coat layer provided thereon and adhesion to the base material layer. As the primer layer, conventionally known primer layers such as an acrylic primer layer, a polyester primer layer, a polyurethane primer layer, a silicone primer layer, and a rubber primer layer can be used.

The thickness of a base material layer (synthetic resin film) is not specifically limited, It can determine suitably according to the use etc. of a laminated film.
The thickness of the base material layer is usually 10 to 500 μm, preferably 20 to 200 μm.

The hard coat layer constituting the laminated film of the present invention is a hard coat agent containing the following component (A), component (B) and component (C) (hereinafter referred to as “hard coat agent (α)”). Is).

The hard coat agent (α) contains an organosilicon compound having a reactive functional group and a hydrolyzable group (hereinafter sometimes referred to as “organosilicon compound (A)”) as the component (A).

The reactive functional group in the organosilicon compound (A) refers to a group that can react with the mercapto group of the component (B) to form a chemical bond.
Examples of the reactive functional group include a group having a carbon-carbon unsaturated bond such as a vinyl group, an allyl group, a styryl group, and a (meth) acryloyloxy group; an epoxy group; an isocyanate group; a mercapto group; Among these, a group having a carbon-carbon unsaturated bond is preferable, and a vinyl group is more preferable.

The hydrolyzable group in the organosilicon compound (A) refers to a group that can form a siloxane bond (Si—O—Si bond) by hydrolysis reaction.
Examples of the hydrolyzable group include alkoxy groups having 1 to 10, preferably 1 to 5 carbon atoms such as methoxy group, ethoxy group, and n-propoxy group; 6 to 15 carbon atoms such as phenoxy group, preferably 6 to 10 carbon atoms. An acyloxy group having 1 to 10 carbon atoms, preferably 1 to 5 carbon atoms such as a formyloxy group, an acetoxy group, or a propionyloxy group; a halogen atom such as a chlorine atom or a bromine atom; Among these, an alkoxy group having 1 to 10 carbon atoms or an acyloxy group having 1 to 10 carbon atoms is preferable, and an acyloxy group having 1 to 10 carbon atoms is more preferable.

Examples of the organosilicon compound (A) include compounds represented by the following formula (I).

In the formula (I), R ¹ represents a group having a reactive functional group, R ² represents a hydrolyzable group, and R ³ represents a non-hydrolyzable group having no reactive functional group.
x is 1, 2 or 3, y is 1, 2 or 3, z is 0, 1 or 2, and the sum of x, y and z is 4.
When x, y, or z is 2 or more, the plurality of R ¹ , R ^2, or R ³ may be the same or different from each other.

Examples of R ¹ include a reactive functional group and a group having a reactive functional group. Specific examples thereof include a group having a vinyl group such as a vinyl group and a vinyloxymethyl group; a group having an allyl group such as an allyl group and an allyloxymethyl group; a group having a styryl group such as a styryl group and a styrylmethyl group. Groups having (meth) acryloyl groups such as (meth) acryloyl groups and 3- (meth) acryloyloxypropyl groups; groups having epoxy groups such as epoxy groups, glycidyl groups and 3-glycidyloxypropyl groups; isocyanate groups; And groups having an isocyanate group such as 3-isocyanatopropyl group; groups having a mercapto group such as mercapto group and 3-mercaptopropyl group; Among these, a group having a carbon-carbon unsaturated bond is preferable, and a vinyl group is more preferable.
R ¹ preferably has 2 to 20 carbon atoms, more preferably 2 to 10 carbon atoms.

Examples of R ² include the hydrolyzable group.
R ² preferably has 0 to 15 carbon atoms, more preferably 0 to 10 carbon atoms.

R ³ is an alkyl group having 1 to 20 carbon atoms, preferably 1 to 15 carbon atoms such as a methyl group, an ethyl group, an n-propyl group, or an isopropyl group; 6 to 20 carbon atoms such as a phenyl group or a 1-naphthyl group; Preferred examples include 6 to 15 aryl groups.

As the organosilicon compound (A), vinyl group-containing silane compounds such as vinyltrimethoxysilane, vinyltriethoxysilane, vinyltriacetoxysilane, vinyltrichlorosilane, and vinyltribromosilane; allyltrimethoxysilane, allyltriethoxysilane, Allyl group-containing silane compounds such as allyltriacetoxysilane, allyltrichlorosilane, allyltribromosilane; γ-acryloxypropyltrimethoxysilane, γ-acryloxypropyltriethoxysilane, γ-acryloxypropyltrichlorosilane, γ-acrylic Γ-acryloxyalkyl group-containing silane compounds such as loxypropyltribromosilane; γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropyltriethoxysilane, γ-methacryloxy Γ-methacryloxyalkyl group-containing silane compounds such as propyltrichlorosilane and γ-methacryloxypropyltribromosilane; α-glycidoxyethyltrimethoxysilane, α-glycidoxyethyltriethoxysilane, β-glycidoxyethyl Trimethoxysilane, β-glycidoxyethyltriethoxysilane, α-glycidoxyethyltrichlorosilane, α-glycidoxyethyltribromosilane, β-glycidoxyethyltrichlorosilane, β-glycidoxyethyltribromo And epoxy group-containing silane compounds such as silane;
Among these, as the organosilicon compound (A), a vinyl group-containing silane compound is preferable, and vinyltriacetoxysilane is more preferable.
An organosilicon compound (A) can be used individually by 1 type or in combination of 2 or more types.

The hard coat agent (α) contains a polythiol compound as the component (B).
By using a hard coat agent containing a polythiol compound in addition to the organosilicon compound, a hard coat layer having excellent transparency, high pencil hardness, and excellent bending resistance can be formed.

The polythiol compound is a compound having two or more mercapto groups in the molecule.
Examples of polythiol compounds include compounds having 2 mercapto groups such as ethylene bis (mercaptoacetate) and ethylene bis (3-mercaptopropionate); trimethylol ethane tris (mercapto acetate), trimethylol ethane tris (3-mercaptopropio Compound) such as pentaerythritol tetrakis (mercaptoacetate), pentaerythritol tetrakis (3-mercaptopropio) ), Dipentaerythritol hexakis (mercaptoacetate), dipentaerythritol hexakis (3-mercaptopropionate) and the like. And the like are; compound.

Among these, as the polythiol compound, a compound having 3 mercapto groups or a compound having 4 or more mercapto groups is preferable, and trimethylolpropane tris (mercaptopropionate) is more preferable.
A polythiol compound can be used individually by 1 type or in combination of 2 or more types.

The content of the polythiol compound is not particularly limited. The content of the polythiol compound is usually 50 to 120% by mass, preferably 60 to 100% by mass, and more preferably 60 to 90% by mass with respect to the component (A).
If a hard coat layer is formed using a hard coat agent with too little polythiol compound content, curling may occur in the laminated film. On the other hand, if a hard coat agent containing too much polythiol compound is used, it may be difficult to form a hard coat layer having high hardness.

The hard coating agent (α) is an inorganic filler having a reactive functional group as the component (C) (an inorganic filler having a reactive functional group introduced on the surface by a modification treatment. (Sometimes referred to as “inorganic filler (C)”).
By using a hard coat agent containing an inorganic filler (C) in addition to the organosilicon compound and the polythiol compound, the hard coat layer has excellent transparency, high pencil hardness, and excellent flex resistance and scratch resistance. Can be formed.

The reactive functional group contained in the inorganic filler (C) refers to a group capable of forming a chemical bond by reacting with the mercapto group of the component (B). Examples of the reactive functional group include the same functional groups as those shown as the reactive functional group of the organosilicon compound (A). Of these, a group having a carbon-carbon unsaturated bond is preferable, and a (meth) acryloyloxy group is more preferable.

Examples of the inorganic component constituting the inorganic filler (C) (component of the inorganic filler before the modification treatment) include metal oxides, metal hydroxides, and metal salts.

Examples of the metal oxide include silica, titanium oxide, alumina, boehmite, chromium oxide, nickel oxide, copper oxide, titanium oxide, zirconium oxide, indium oxide, and zinc oxide.
Examples of the metal hydroxide include aluminum hydroxide.
Examples of the metal salt include metal carbonates such as calcium carbonate and magnesium carbonate; metal sulfates such as calcium sulfate and barium sulfate; metal silicates such as aluminum silicate, calcium silicate and magnesium silicate;
Among these, as an inorganic component which comprises an inorganic filler (C), a metal oxide is preferable and a silica is more preferable.

The shape of the inorganic filler (C) may be any of a spherical shape, a chain shape, a needle shape, a plate shape, a piece shape, a rod shape, a fiber shape, etc., but a spherical shape is preferable. Here, the spherical shape means a substantially spherical shape including a polyhedral shape that can be approximated to a sphere, such as a spheroid, oval, scallop, and eyebrows, in addition to a true sphere.

The magnitude | size of an inorganic filler (C) is not specifically limited. The average particle size of the inorganic filler (C) is usually 5 to 1000 nm, preferably 10 to 500 nm, more preferably 20 to 100 nm.
When the average particle diameter of the inorganic filler (C) is within the above range, a hard coat layer having excellent transparency and scratch resistance can be efficiently formed.
The average particle diameter of the inorganic filler (C) can be calculated using the specific surface area obtained by the BET method.
An inorganic filler (C) can be used individually by 1 type or in combination of 2 or more types.

The content of the inorganic filler (C) is not particularly limited. The content of the inorganic filler (C) is usually 30 to 130% by mass, preferably 60 to 125% by mass, more preferably 90 to 125% by mass with respect to the component (A).
When a hard coat agent having an inorganic filler (C) content of 90 to 125% by mass with respect to the component (A) is used, a hard coat layer having high hardness can be easily formed.
Further, when a hard coat agent having an inorganic filler (C) content of 90 to 125% by mass with respect to the component (A) is used, it becomes easy to form a hard coat layer having excellent scratch resistance.

The hard coat agent (α) may contain other components in addition to the component (A), the component (B), and the component (C) as long as the effects of the present invention are not impaired. Examples of other components include a solvent and a photopolymerization initiator.

Since the hard coat agent containing a solvent is excellent in coatability, a thin hard coat layer can be efficiently formed by using a hard coat agent containing a solvent.
Solvents include aliphatic hydrocarbon solvents such as hexane, heptane and cyclohexane; aromatic hydrocarbon solvents such as toluene and xylene; halogenated hydrocarbon solvents such as methylene chloride and ethylene chloride; methanol, ethanol, propanol, Alcohol solvents such as butanol and 1-methoxy-2-propanol; ketone solvents such as acetone, methyl ethyl ketone, 2-pentanone, methyl isobutyl ketone and isophorone; ester solvents such as ethyl acetate and butyl acetate; cellosolve such as ethyl cellosolve System solvents; and the like.
A solvent can be used individually by 1 type or in combination of 2 or more types.

When the hard coating agent (α) contains a solvent, the content of the solvent is preferably such that the solid content concentration of the hard coating agent (α) is 30 to 95% by mass or more, and 35 to 90% by mass. Is more preferable, and an amount of 40 to 85% by mass is even more preferable.

By using a hard coating agent containing a photopolymerization initiator, the resulting coating film can be efficiently cured after coating the hard coating agent.
Examples of the photopolymerization initiator include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin-n-butyl ether, benzoin isobutyl ether, 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'-diethylaminobenzo Phenone, 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-dimethylaminobenzoate, and the like.
A photoinitiator can be used individually by 1 type or in combination of 2 or more types.

When the hard coating agent (α) contains a photopolymerization initiator, the content of the photopolymerization initiator is usually 0.01 to 10% by mass, preferably based on the total solid content of the hard coating agent (α). Is 0.5 to 10% by mass.

The thickness of the hard coat layer constituting the laminate film of the present invention is usually 0.1 to 50 μm, preferably 0.5 to 20 μm.

When the Young's modulus of the surface of the hard coat layer constituting the laminate film of the present invention is measured using an atomic force microscope, the region having a Young's modulus of 1 to 5 GPa constitutes a continuous structure, and the Young A region having a rate of 6 to 10 GPa is isolated and dispersed.

“A region having a Young's modulus of 1 to 5 GPa constitutes a continuous structure” means that a region having a Young's modulus of 1 to 5 GPa continuously forms one large phase (the structure of the sea part in the so-called sea-island structure). The same thing is formed).
“A region with a Young's modulus of 6 to 10 GPa is isolated and dispersed” means that a region with a Young's modulus of 6 to 10 GPa is dispersed in the whole (the same structure as the island portion in the so-called sea-island structure is formed). That).
A hard coat layer in which a region having a Young's modulus of 1 to 5 GPa constitutes a continuous structure can relieve stress during bending efficiently and has excellent bending resistance. On the other hand, the region having a Young's modulus of 6 to 10 GPa is isolated and dispersed, so that the hard coat layer has sufficient hardness for contact with a millimeter-scale material such as a pencil tip.

The Young's modulus of the hard coat layer surface can be measured according to the method described in the examples.

Each region with a Young's modulus of 6-10 GPa is preferably nano-sized. For example, when a square or rectangle in which the region is inscribed is drawn, the length of the side is preferably 10 to 100 nm, more preferably 40 to 60 nm.

As described below, the hard coat layer having these structures is efficiently prepared by adjusting the amounts of the components (A), (B), and (C) contained in the hard coat agent (α). Can be formed.

First, the reactive functional group contained in the component (A) or the component (C) constituting the hard coat agent (α) can react with the mercapto group of the component (B), and these reactive functional groups. Even groups can react.
If the reaction between the reactive groups of the component (C) mainly proceeds, the component (C) aggregates in part and a hard coat layer having the desired structure cannot be formed.
Therefore, by using the component (B) in such an amount that the reaction between the mercapto group contained in the component (B) and the reactive functional group contained in the component (A) or the component (C) sufficiently proceeds, (C) The dispersibility of the components can be increased.

Further, the reaction between these reactive functional groups and mercapto groups is an addition reaction, and even if this reaction occurs, the hard coat layer is unlikely to shrink. On the other hand, if the reaction between the reactive functional groups occurs more than necessary, local curing shrinkage may occur, and optical characteristics may be deteriorated or curling may occur.
In this respect, when the reactive functional groups are reacted with each other, it is usually necessary to irradiate or heat active energy rays such as ultraviolet rays or electron beams, and thus the reactive functional groups and mercapto groups are required. Reaction proceeds faster than the reaction between reactive functional groups. Therefore, if necessary, a hard coat layer having the desired characteristics can be efficiently formed by examining the stage of irradiating or heating active energy rays such as ultraviolet rays and electron beams.

Thus, depending on the amount of the reactive functional group contained in the component (A) or the component (C) to be used, an appropriate amount of the component (B) is used to sufficiently react the reactive functional group with the mercapto group. By carrying out, it is possible to form a hard coat layer having the above-described structure, excellent optical characteristics and flex resistance, and hardly causing curling.

The laminated film of the present invention is produced, for example, by applying a hard coating agent (α) directly or via another layer on a synthetic resin film serving as a base material layer and curing the obtained coating film. can do.

The method for applying the hard coating agent on the synthetic resin film is not particularly limited, and a known method can be employed. For example, roll coating method, curtain flow coating method, Mayer bar coating method, reverse coating method, gravure coating method, gravure reverse coating method, air knife coating method, kiss coating method, blade coating method, smooth coating method, roll knife coating method, etc. Is mentioned.

The method for curing the coating film is not particularly limited. For example, the coating film can be cured by irradiating the coating film with active energy rays such as ultraviolet rays and electron beams.
Ultraviolet irradiation can be performed by a high-pressure mercury lamp, a fusion H lamp, a xenon lamp, or the like. The irradiation amount of ultraviolet rays is preferably about 50 to 1000 mW / cm ² in illuminance and about 50 to 1000 mJ / cm ^{2 in} light quantity. On the other hand, the electron beam irradiation can be performed by an electron beam accelerator or the like. The irradiation amount of the electron beam is preferably about 10 to 1000 krad.

When forming a hard-coat layer, you may perform a drying process before hardening of a coating film or after hardening of a coating film as needed.
Drying process conditions are not particularly limited. The drying temperature is, for example, 40 to 150 ° C., preferably 60 to 140 ° C., and the drying time is, for example, 30 seconds to 1 hour, preferably 1 to 30 minutes.

The hard coat layer has high hardness and excellent scratch resistance.
The hard coat layer constituting the laminated film of the present invention usually exhibits a hardness of F or higher and preferably H or higher when a pencil scratch hardness test is performed according to the method described in the examples.
When the hard coat layer constituting the laminated film of the present invention is evaluated for scratch resistance according to the method described in the examples, scratches are usually not observed.

The laminated film of the present invention is preferably excellent in transparency. 89% or more is preferable and 90% or more is more preferable when the laminated film of this invention measures a total light transmittance. Although there is no upper limit in particular, it is usually 95% or less.
The laminated film of the present invention preferably has excellent bending resistance. When the laminated film of the present invention is subjected to a mandrel bending test according to JIS K5600-5-1, it is preferably 4 mmΦ or less, more preferably 2 mmΦ or less.
The laminated film of the present invention is preferably one having little warpage. When the curl property of the laminated film of the present invention is evaluated according to the method described in Examples, it is usually 75 mm or less, preferably 50 mm or less. Although there is no lower limit in particular, it is usually 3.5 mm or more.

The laminated film of the present invention has a hard coat layer with high hardness and excellent scratch resistance and flex resistance, and is suitably used as a touch panel manufacturing material.

Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to the following examples.
Unless otherwise indicated, the part and% in each example are based on mass.

The compounds used in Examples and Comparative Examples are shown below.
Solution (A1) of organosilicon compound (vinyltriacetoxysilane) (manufactured by Sakai Chemical Co., Ltd., trade name: SHC-001B, concentration 90%)
Solution (B1) of polythiol compound [trimethylolpropane tris (3-mercaptopropionate)] (manufactured by Sakai Chemical Co., Ltd., trade name: SHC-001A, concentration 60%)
Inorganic filler (silica nanofiller having acryloyloxy group) dispersion (C1) (manufactured by Nissan Chemical Industries, trade name: AC-4130Y, concentration 30%, average particle size 40-50n)

[Example 1]
110 parts of the organosilicon compound solution (A1), 150 parts of the polythiol compound solution (B1) and 398 parts of the inorganic filler dispersion (C1) were mixed, and the resulting mixture was diluted with methyl ethyl ketone to obtain a concentration of 45%. A hard coat agent (1) was prepared.
Apply a hard coat agent (1) to a polyethylene terephthalate film with a single-sided primer layer (manufactured by Toyobo Co., Ltd., trade name: PET50A4100, thickness 50 μm) using a Mayer bar # 10 so that the film thickness after curing is 5 μm. The coated film was cured by irradiating with ultraviolet rays (light quantity: 500 mJ / cm ² ). Next, the cured coating film was dried at 120 ^° C. for 20 minutes to form a hard coat layer to obtain a laminated film (1).

[Comparative Example 1]
110 parts of the organosilicon compound solution (A1) and 100 parts of the polythiol compound solution (B1) were mixed, and the resulting mixture was diluted with methyl ethyl ketone to prepare a hard coat agent (2) having a concentration of 50%.
Instead of using the hard coating agent (1) in Example 1, a laminated film (2) was obtained in the same manner as in Example 1 except that the hard coating agent (2) was used.

[Comparative Example 2]
110 parts of the organosilicon compound solution (A1), 100 parts of the polythiol compound solution (B1) and 278 parts of the inorganic filler dispersion (C1) were mixed, and the resulting mixture was diluted with methyl ethyl ketone to give a concentration of 50%. A hard coat agent (3) was prepared.
Instead of using the hard coat agent (1) in Example 1, a laminated film (3) was obtained in the same manner as in Example 1 except that the hard coat agent (3) was used.

[Comparative Example 3]
110 parts of the organosilicon compound solution (A1), 100 parts of the polythiol compound solution (B1) and 333 parts of the inorganic filler dispersion (C1) were mixed, and the resulting mixture was diluted with methyl ethyl ketone to obtain a concentration of 50%. A hard coat agent (4) was prepared.
Instead of using the hard coating agent (1) in Example 1, a laminated film (4) was obtained in the same manner as in Example 1 except that the hard coating agent (4) was used.

[Comparative Example 4]
A mixture of organically modified silica fine particles and polyfunctional acrylate (manufactured by JSR, trade name: Opster Z7530, concentration 73%, with photopolymerization initiator, inorganic filler content 60%) is diluted with propylene glycol monomethyl ether to obtain a concentration of 40 % Hard coating agent (5) was prepared.
Apply a hard coat agent (5) to a polyethylene terephthalate film with a single-sided primer layer (manufactured by Toyobo Co., Ltd., trade name: PET50A4100, thickness 50 μm) using a Mayer bar # 10 so that the film thickness after curing is 5 μm. The obtained coating film was dried at 100 ° C. for 1 minute. Subsequently, this coating film was irradiated with ultraviolet rays (light amount: 500 mJ / cm ² ) to cure the coating film, thereby forming a hard coat layer to obtain a laminated film (5).

The following evaluation was performed on the laminated films (1) to (5) obtained in Example 1 and Comparative Examples 1 to 4. The results are shown in Table 1.

[Thickness evaluation]
The thickness of the hard coat layer was measured using a thickness meter (trade name: MH-15, manufactured by Nikon Corporation) according to JIS K 7130 (1999).

[Total light transmittance]
The total light transmittance of the laminated film was measured according to JIS K 7361-1 (1997) using a haze meter (trade name: N-DH-2000, manufactured by Nippon Denshoku Co., Ltd.).

[Pencil hardness]
Using a pencil scratch hardness tester (manufactured by Yasuda Seiki Seisakusho Co., Ltd., trade name: No. 553-M) according to JIS K5600-5-4 (1999), a pencil with a load of 750 g and a scratching speed of 0.5 mm / sec. A scratch hardness test was conducted.

[Abrasion resistance evaluation]
The hard coat layer of the laminated film is rubbed 10 times in a 50 mm length range with a load of 250 g / cm ² using steel wool # 0000, and then visually checked for the presence or absence of scratches. Evaluated.
○: There is no scratch.
X: There are scratches.

[Bend resistance evaluation]
In accordance with JIS K5600-5-1 (1999), a mandrel bending test was performed to evaluate the bending resistance of the laminated film.

[Curl evaluation]
The laminated film was cut into a 10 cm side square and used as a test piece. The test piece was placed on a horizontal table, and the floating (mm) at the four corners at this time was measured, and the total value was calculated.

[Young's modulus measurement]
Force curve measurement was performed using an atomic force microscope (AFM), and the local Young's modulus of the hard coat layer surface was calculated by the following method.
The AFM is a MultiMode 8 AFM manufactured by Bruker AXS, and the cantilever is an OMCL-AC160TS-C2 manufactured by Olympus (spring constant (nominal value 42 N / m, measured value by thermal fluctuation method 32.7 N / m), probe Needle tip radius 15 nm] was used.
First, a graph representing the relationship between the amount of warpage of the cantilever and the amount of displacement of the piezo scanner when the cantilever is pushed into the hard coat layer and when the cantilever is pulled away from the hard coat layer is obtained by force curve measurement. By converting this, a graph (F-δ curve) representing the relationship between the load and the amount of deformation of the sample is obtained.
The local Young's modulus E in the sample can be obtained by performing curve fitting using the DMT theoretical formula by Derjaguim, Muller, Toporov et al. For the indentation process in the obtained F-δ curve.
In this measurement, force curve measurement and Young's modulus E were calculated for 128 × 128 points (16384 points in total) in the 1 μm × 1 μm plane of each sample.
The measurement results are shown in FIGS.

1 to 5 and Table 1 show the following.
In the hard coat layer of the laminated film (1) obtained in Example 1, the region having a Young's modulus of 1 to 5 GPa forms a continuous structure as shown in FIG. 1, and the region having a Young's modulus of 6 to 10 GPa. Are isolated and dispersed. The laminated film (1) has excellent transparency, high hardness, and excellent scratch resistance and flex resistance.
As shown in FIG. 2, the hard coat layer of the laminated film (2) obtained in Comparative Example 1 has a region where the Young's modulus is 1 to 5 GPa. The laminated film (2) is excellent in flex resistance but low in hardness and inferior in scratch resistance.
The hard coat layers of the laminated films (3) and (4) obtained in Comparative Examples 2 and 3 are not isolated in the region where the Young's modulus is 6 to 10 GPa as shown in FIGS. A continuous structure is also formed in the region where the rate is 6 to 10 GPa. The laminated films (3) and (4) having the hard coat layer having such a structure are inferior in bending resistance even if the inorganic filler content is the same or small.
The hard coat layer of the laminated film (5) obtained in Comparative Example 4 has a high Young's modulus as a whole as shown in FIG. The laminated film (5) has high hardness and excellent scratch resistance but is inferior in flex resistance.

Claims

A laminated film having a base material layer and a hard coat layer,
The hard coat layer is formed using a hard coat agent containing the following component (A), component (B), and component (C):
When the Young's modulus of the surface of the hard coat layer was measured using an atomic force microscope, a region having a Young's modulus of 1 to 5 GPa constituted a continuous structure, and a region having a Young's modulus of 6 to 10 GPa was isolated and dispersed. A laminated film characterized by being made.
(A) Component: Organosilicon compound having reactive functional group and hydrolyzable group (B) Component: Polythiol compound (C) Component: Inorganic filler having reactive functional group