JP2000185362A - Manufacture of metal element-containing thin film laminate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize high surface hardness and excellent adhesiveness with a transparent base material by electrically discharging a hard coat layer, then forming a surface roughness to specific times as much as that before treating, specifying a ratio of number of carbon elements originated from a carboxyl of a surface, and then laminating a metal element-containing thin film. SOLUTION: A hard coat layer is electrically discharged before a metal element-containing thin film is laminated. Then, a ratio of a surface roughness (Ra0) before the treating to a surface roughness (Ra1) after the treating is set to Ra0/Ra1 <= three times. Further, a ratio of number of carbon elements originated from a carboxyl occupying total number of carbon elements of a surface of the coat layer is set to 0.5 to 2.5%. As the discharging, a corona discharging, an atmospheric plasma discharging or the like is used. Then, a metal element- containing thin film is laminated on a surface of the discharged coat layer by sputtering or the like. Thus, a high surface hardness and excellent adhesiveness with a transparent base material can be realized.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing a metal element-containing thin film laminate.

[0002]

2. Description of the Related Art Conventionally, flat panel displays,
As for the CRT display, there is a problem that the surface is reflected by light from the outside, and the visual information inside is difficult to see. In order to solve such a problem, a method of preventing reflection by etching the surface has been devised. However, there is a problem that not only the quality is varied but also the transmitted image quality is deteriorated.

After that, there has been proposed a method of forming an antireflection film by a combination of a low refractive index layer and a high refractive index layer by a method such as coating, vapor deposition, sputtering, and plasma CVD. For the high and low refractive index materials used in the antireflection film, a metal oxide material is mainly used.In order to provide the antireflection function while maintaining the transmittance of the antireflection film, the A metal-containing thin film having a thickness of about 0.1 μm is laminated in a single layer or a plurality of layers.

[0004] However, the metal-containing thin film has poor scratch resistance and has a problem in surface hardness. Therefore, a technique of providing a layer having an acrylate-based functional group as a hard coat layer (cured coating layer) on a substrate and laminating a metal-containing thin film on the hard coat layer to improve the surface hardness is widely used. However, there is a defect in adhesion between the hard coat layer made of an organic material and the metal-containing thin film made of an inorganic material, and there has been a problem such as surface peeling.

[0005] As a measure for improving the adhesion between the hard coat layer and the metal-containing thin film, a highly polar functional group such as a carboxyl group is formed on the surface of the hard coat layer to form a hydrogen bond at the interface of the metal element-containing thin film. There are ways to increase power. However, even when a monomer having a polar group is mixed in the hard coat paint, there is a problem that a highly polar functional group is not exposed on the surface of the hard coat and its effect is not sufficiently exhibited.

A method has been proposed in which the surface of the hard coat is subjected to oxygen plasma treatment to activate the surface and improve the adhesion (Japanese Patent Laid-Open No. 2-87101). However, the surface activated by the generation of radicals and the like is quickly deactivated, and it is necessary to form a metal-containing thin film immediately after the treatment. Further, the activation treatment by plasma generally requires a long-term treatment of 1 minute or more. However, if the treatment energy is too high, the surface of the base material is greatly deteriorated, and conversely, the adhesion is reduced. There was a problem.

[0007]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems, and has a high surface hardness of a metal-containing thin film and an excellent adhesion to a transparent substrate, so that the reflection of flat panel displays, CRT displays and the like can be improved. An object of the present invention is to provide a method for producing a metal-containing thin film laminate that can be suitably used as a coating for prevention.

[0008]

According to the present invention, there is provided a thin film containing a metal element.
The method for producing a film laminate includes a hard coat layer on a transparent substrate.
Element-containing thin film laminated with metal element-containing thin film via
A method for manufacturing a laminate, wherein a discharge treatment is applied to the hard coat layer.
The surface roughness after treatment (Ra) ₁Process)
Surface roughness before (Ra₀3) or less and the surface after treatment
Element derived from carboxyl group in the total number of carbon elements
Metal-containing thin film after setting the ratio of numbers to 0.5-2.5%
Are laminated.

The transparent substrate used in the present invention includes:
There is no particular limitation as long as it is a transparent substrate. For example, polyethylene, polypropylene, polyester, regenerated cellulose, diacetyl cellulose, triacetyl cellulose, polyvinyl chloride, polyvinylidene chloride, polyvinyl alcohol, polystyrene, polyethylene terephthalate (PET) And films and sheets of polybutylene terephthalate, polycarbonate (PC) polyimide, nylon, thermosetting polyester and the like. Among them, films and sheets of triacetyl cellulose, PET, PC and the like are preferable because of their excellent transparency. It is.

The hard coat layer used in the present invention is not particularly limited, but is formed of, for example, a hard coat material. As the hard coat material, for example, a polyfunctional acrylate, urethane acrylate, a silicon-based compound, or the like alone or a mixture thereof is used.

Examples of the polyfunctional acrylate include pentaerythritol hexa (meth) acrylate, dipentaerythritol hexa (meth) acrylate, pentaerythritol penta (meth) acrylate, dipentaerythritol penta (meth) acrylate, and pentaerythritol (meth) acrylate. ) Tetraacrylate, dipentaerythritol (meth) tetraacrylate, pentaerythritol tri (meth) acrylate,
Dipentaerythritol tri (meth) acrylate, pentaerythritol glycidyl (meth) acrylate,
And trimethylolpropane tri (meth) acrylate, and derivatives and modified products thereof. These may be used alone or in combination of two or more.

Examples of commercially available polyfunctional acrylates include "EXF-37" manufactured by Dainichi Seika.

The above-mentioned silicon-based compound is preferably composed of at least one silicon-based compound selected from the group consisting of silica fine particles surface-coated with an organic substance, organopolysiloxane and silicone acrylate.

Examples of the silica fine particles surface-coated with an organic substance include those shown in FIG. 1 or FIG. Here, Co-Si represents colloidal silica, and R ¹ and R ² in FIG. 2 each represent an alkyl group. Note that R ¹ and R ² may be different from each other or may be the same.

Commercially available silica fine particles surface-treated with the above organic substances include, for example, "UVHC-1103" and "UVHC-1105" manufactured by Toshiba Silicone Co., Ltd.

As the organopolysiloxane, those having a structure represented by the following general formula (I), (II) or (III) are used.

[0017]

Embedded image

In the formulas (I), (II) and (III),
m and n are positive integers, respectively. When (m + n) is too small, the hardness of the obtained hard coat layer is lowered and the hard coat performance is inferior. Because of the problem, 100 ≧ (m
+ N) ≧ 10, more preferably 50 ≧ (m
+ N) ≧ 15.

The silicone acrylate is represented by the general formula (CH ₃ O) ₃ SiR ³ O—CO—CR ⁴ ＣＨCH ₂ , wherein R ³ and R ⁴ each represent an alkyl group. Note that R ³ and R ⁴ may be different from each other or may be the same.

The above urethane acrylate is produced by a known method using a polyol, diisocyanate and hydroxy (meth) acrylate. Examples of commercially available urethane acrylates include "EXS-07" manufactured by Dainichi Seika.

In the present invention, when forming the hard coat layer, a non-polymerizable diluting solvent may be used in order to adjust the viscosity of the hard coat material to be used. Examples of the non-polymerizable diluting solvent include, for example, toluene, xylene, ethyl acetate, butyl acetate, methyl cellosolve, ethyl cellosolve, ethyl cellosolve acetate, isopropyl alcohol, methyl ethyl ketone, and the like. Or two or more of them may be used in combination.

A hard coat layer can be formed by applying and hardening the above hard coat material on a transparent substrate.

As a method of applying the above-mentioned hard coat material on a transparent substrate, a known coating method such as spray coating, gravure coating, roll coating, bar coating and the like can be used. It is preferable to adjust in consideration of the physical properties and thickness of the hard coat layer to be formed.

The method of curing the hard coat material is not particularly limited as long as it initiates and accelerates the polymerization reaction of the acryloyl group, and known methods such as irradiation with ultraviolet light and heating can be employed.

Other components can be added to the hard coat material of the present invention as long as the performance is not impaired. For example, pigments, fillers, surfactants, dispersants, plasticizers, ultraviolet absorbers Agents, antioxidants and the like may be added.
These components may be used alone or in combination of two or more.

The thickness of the hard coat layer is preferably from 1 to 15 μm since the surface hardness decreases as the thickness decreases, and cracks occur in the hard coat layer itself and the adhesion with the metal-containing thin film decreases as the thickness increases. Preferably 2-8μ
m.

Before laminating a metal element-containing thin film on the hard coat layer, a discharge treatment is performed so as to satisfy the following two conditions.

First, in the discharge treatment, the ratio of the surface roughness (Ra ₀ ) before the treatment to the surface roughness (Ra ₁ ) after the treatment, Ra ₁
/ Ra ₀ ≦ 3 times. Ra ₁ / R
When the ratio of a ₀ exceeds three times, the surface of the hard coat layer is severely damaged by the discharge treatment, and a large amount of low molecular weight substances are generated on the surface, so that the adhesion to the metal element-containing thin film is reduced.

Second, the ratio of the number of carbon elements derived from carboxyl groups to the total number of carbon elements on the surface of the hard coat layer must be 0.5 to 2.5% by the discharge treatment. When the ratio of the number of carbon elements derived from the carboxyl group is less than 0.5%, sufficient adhesion to the metal element-containing thin film cannot be obtained, and when it exceeds 2.5%, the surface roughness is remarkable. Become larger.

The ratio of the number of carbon elements derived from a carboxyl group to the total number of carbon elements on the surface of the hard coat layer is ES
Determined by CA analysis. In the ESCA analysis, first, a carboxyl group is esterified by reacting with trifluoroethanol, and then the ratio X of trifluoromethyl (CF ₃ ) is determined by waveform separation of the C1s spectrum of ESCA.
%, And the ratio of the carboxyl group to the total number of carbon elements on the surface is calculated by the following equation. Carboxyl group ratio (%) = [X / (100−X)]
× 100

By forming the hard coat layer, a carboxyl group having a high polarity on the surface of the hard coat is strongly bonded to a metal-containing thin film laminated thereon via a hydrogen bond or the like. improves.

The discharge treatment includes corona discharge treatment,
Although a plasma discharge treatment and the like can be mentioned, a corona discharge treatment and a normal pressure plasma discharge treatment are preferable in view of the simplicity of the apparatus and the possibility of continuous treatment.

When the corona discharge treatment is performed, a general device including a high-frequency power supply device, a discharge electrode and a dielectric can be used as the device. Such a device can be used, for example, by Kasuga Electric Co., Ltd. Co., Ltd.). The processing conditions for corona discharge vary depending on the electrode structure, the distance between the electrodes, and the like. However, in order to suppress an increase in surface roughness, it is preferable to perform the processing for a short time with a relatively weak output of 0.1 to 0.8 kW.

As a device for performing the plasma discharge treatment, a general device including a power supply device, a discharge electrode, a gas introduction tube, a vacuum chamber, and a vacuum exhaust device can be used. ) Sold by Samco International Laboratories, Nanotech Co., Ltd.

Examples of the method of generating plasma include a method of applying a direct current, applying a high frequency, a method of plasma-decomposing a gas by microwave discharge, electron cyclotron resonance, a method of thermally decomposing by a hot filament, and a processing pressure of 1 ×. In addition to the method performed under a low pressure in the range of 10 ^{-4 to} 100 Torr, a voltage is applied between opposed metal electrodes having a solid dielectric disposed on at least one of the opposed surfaces under a pressure near atmospheric pressure. Then, a method of generating plasma is used. The electric field applied between the electrodes may be an AC waveform or a pulsed electric field.

The processing gas used in the plasma discharge processing is not particularly limited, and for example, argon, helium, nitrogen, air, an oxygen element-containing gas and the like can be used. These may be used alone or as a mixture. Examples of the oxygen element-containing gas include oxygen, ozone, water, carbon monoxide, carbon dioxide, nitric oxide, nitrogen dioxide, alcohols such as methanol and ethanol; ketones such as acetone and methyl ethyl ketone; formaldehyde; Examples include organic compounds containing an oxygen element such as aldehydes such as acetaldehyde, and these may be used alone or in combination of two or more.

The time for the plasma discharge treatment is appropriately determined in consideration of the processing gas and the applied voltage. However, in order to suppress an increase in the surface roughness, the time may be set to a relatively short range of 5 to 30 seconds. preferable.

Next, the hard disk having been subjected to the discharge treatment
A metal-containing thin film is laminated on the surface of the coating layer. Metal-containing thin film
As a method of laminating, for example, sputtering, steam
Metal-containing thin film by deposition, plasma CVD, coating, etc.
There is a method of forming a film. The film type of the metal-containing thin film and
Is not particularly limited._Two, SiO _Two,
MgF_TwoMetal compounds such as Au, Ag, Cu, Pt, etc.
Metals and the like can be mentioned. Especially the thickness of the metal-containing thin film
It is not limited and depends on the purpose.
When used, 100 to 3000 ° is preferable.

[0039]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in more detail by way of examples.

Example 1 A polyfunctional acrylate (“EXF-37” manufactured by Dainichi Seika Co., Ltd.) was used as a hard coat material.
An 80 μm-thick triacetate film (“KC-80UV” manufactured by Konica) was applied using a wire bar # 6 to prepare a film having a coating layer. After heating and drying the coating layer of the obtained film, the coating layer was coated with 300 mJ.
Irradiation with an ultraviolet lamp was carried out at / cm ² to produce a film having a hard coat layer. This hard coat layer surface,
Corona discharge treatment was performed by passing once through an electric field of 0.6 kW at a speed of 3 m / min. Then, a Ti target was sputtered on the surface of the hard coat layer under an electric field of 2 kW and 13.56 MHz under a condition of 0.1 Torr to form a metal-containing thin film having a thickness of 1000 mm.
A laminate in which the O ₂ film was laminated was obtained.

(Example 2) 0.3 kW, 13.56 MH
A laminated body in which a 1000 mm thick TiO ₂ film was laminated was obtained in the same manner as in Example 1 except that the corona discharge treatment was performed by passing once through the electric field of z at a speed of 3 m / min. .

(Embodiment 3) Instead of Ti target, Si
A laminate was obtained in the same manner as in Example 2 except that a metal-containing thin film made of SiO ₂ was laminated as a metal-containing thin film using a target.

(Example 4) 0.6 kW, 13.56 MH
The hard coat layer which has been subjected to corona discharge treatment by passing through the electric field of z at a speed of 3 m / min four times is coated with a metal-containing thin film of a TiO ₂ film having a thickness of 1000 mm and a SiO film having a thickness of 850 mm by a normal pressure plasma CVD method. _A laminated body was obtained in the same manner as in Example 1 except that _two films were laminated in this order.

(Example 5) Polyfunctional acrylate ("EXF-37" manufactured by Dainichi Seika Co., Ltd.) 100 was used as the hard coat material.
After a hard coat layer was formed using 10 parts by weight of a mixture of silicone acrylate and silica particles ("1103" manufactured by Toshiba Silicone Co., Ltd.), the surface of the hard coat layer was plasma-treated. In the same manner as in Example 1, a laminate in which metal-containing thin films were laminated was obtained. In the plasma processing, oxygen is used as a processing gas, and the pressure is 1 To.
The treatment was performed at rr for 15 seconds.

(Example 6) Polyfunctional acrylate (“EXF-37” manufactured by Dainichi Seika Co., Ltd.) 100 was used as the hard coat material.
Parts by weight, 10 parts by weight of a mixture of silicone acrylate and silica particles (“1103” manufactured by Toshiba Silicone Co., Ltd.), and urethane acrylate (“EXS-0” manufactured by Dainichi Seika Co., Ltd.)
7) A laminated body in which a metal-containing thin film was laminated in the same manner as in Example 1 except that a hard coat layer was provided using 10 parts by weight and then the surface of the hard coat layer was subjected to plasma treatment. In the plasma processing, Ar was used as a processing gas, a pulse electric field having a waveform having a voltage rise time of 5 μs, an applied voltage of 11 kV, a frequency of 6 kHz, and a pulse width of 100 μs was applied under a condition of a pressure of 760 Torr.
mm, using Al ₂ O ₃ as a solid dielectric,
The treatment was performed under the condition of a treatment time of 10 seconds.

Comparative Example 1 A laminate having a metal-containing thin film laminated thereon was obtained in the same manner as in Example 1 except that no corona discharge treatment was performed.

(Comparative Example 2) In an electric field of 0.1 kW, 3 m /
A laminate having the same metal-containing thin film as in Example 1 after the hard coat layer was formed in the same manner as in Example 1 except that the corona discharge treatment was performed by passing once at a speed of one minute. I got

(Comparative Example 3) In an electric field of 0.1 kW, 3 m /
A laminate in which a metal-containing thin film similar to that of Example 2 was formed after forming a hard coat layer in the same manner as in Example 2 except that corona discharge treatment was performed by passing 10 times at a speed of 1 minute. I got

With respect to the hard coat layer and the laminate obtained in the above Examples and Comparative Examples, the following items were evaluated for performance.
The results are shown in Table 1.

(1) Ratio of carbon element derived from carboxyl group in hard coat layer Carboxyl group is esterified by reacting with trifluoroethanol gas at 45 ° C. for 24 hours in the presence of pyridine and N, N′-dicyclohexylcarbodiimide. , ESC
The ratio X% of trifluoromethyl (CF ₃ ) was determined by waveform separation of the C1s spectrum of A, and the ratio of the number of carbon elements derived from carboxyl groups to the total number of carbon elements on the surface was calculated by the following equation. Ratio (%) of the number of carbon elements derived from carboxyl groups = [X /
(100-X)] × 100

(2) Method of Measuring Surface Roughness The surface condition was measured using an atomic force microscope, and a surface roughness of 5 μm square was obtained using analysis software.

(3) Pencil hardness test Pencil hardness was measured according to JIS K 6894.

(4) Adhesion Evaluation Test The surface of the metal-containing thin film after 10,000 hours under the conditions of 40 ° C. and 95% RH was subjected to an adhesive tape peeling test according to JIS D0202. Of the 100 cells provided on the metal-containing thin film, the number of cells not peeled off by the adhesive tape was counted.

[0054]

[Table 1]

[0055]

According to the method for producing a metal element-containing thin film laminate of the present invention, the metal element-containing thin film obtained has a high surface hardness and an excellent adhesion to a transparent base material.
It can be suitably used as an antireflection film for a flat panel display, a CRT display and the like.

[Brief description of the drawings]

FIG. 1 is a schematic view showing one example of silica fine particles coated with a surface treatment.

FIG. 1 is a schematic view showing another example of silica fine particles coated with a surface treatment.

Continued on front page F-term (reference) 4F100 AA20 AA21 AB01C AJ06 AK01B AK25 AR00A AS00B BA03 BA07 BA10A BA10C DD07B EH461 EH662 EJ421 EJ55B EJ861 GB41 JK06 JK12 JM02C JN01A YY00B 4K002 BA01 BA46 BA03 BA01 FA01 HA04 LA18

Claims (1)

[Claims] 1. A method for producing a metal element-containing thin film laminate in which a metal element-containing thin film is laminated on a transparent substrate via a hard coat layer, wherein the hard coat layer is subjected to a discharge treatment, The surface roughness (Ra ₁ ) after the treatment is not more than three times the surface roughness (Ra ₀ ) before the treatment, and the ratio of the number of carbon elements derived from the carboxyl group to the total number of carbon elements on the surface after the treatment is 0. A method for producing a metal element-containing thin film laminate, comprising laminating a metal-containing thin film after reducing the content to 5 to 2.5%.