JP2003327870A - Coating for forming metal reflection film and metal reflection film using the coating and article having the film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a coating which is used for forming metal reflection films and can easily form the metal reflection films having excellent metal gloss at low costs, to provide the metal reflection film using the coating, and to provide an article having the metal reflection film. <P>SOLUTION: This coating for forming the metal reflection films is characterized by homogeneously dispersing metal fine particles having an average primary particle diameter of 1 to 50 nm and an average secondary particle diameter of 50 to 200 nm in a coating. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coating material for forming a metal reflection film, a metal reflection film using the same, and an article provided with the same. More specifically, the application of the coating to the surface of a substrate requires heating. Paint for forming a metal reflection film that can obtain a reflection film having excellent reflection efficiency without any use, a metal reflection film using this paint, a reflector provided with this metal reflection film, a reflection film, a semiconductor device, a semiconductor component, Various display devices such as plasma display panels (PDP) and liquid crystal displays (LCD), polarizing plates, reflective electrodes, light guide plates, optical disks,
The present invention relates to articles such as metallic luster-like ornaments and half mirror ornaments.

[0002]

2. Description of the Related Art Conventionally, metal reflective films have been used as metal films for semiconductor parts, reflective plates for reflective liquid crystal displays, reflective plates for projection displays, reflective films for optical disks, polarizing films and reflective electrodes for liquid crystal displays, and copying machines. It is used in a wide range of optical fields such as laser mirrors. As such a metal reflection film, generally, a vacuum deposition method,
Sputtering method, CVD (Chemical Vapor Depositio)
A metal thin film formed by a dry film forming technique such as the n) method is used. Further, in the transmissive / reflective liquid crystal display, a semi-transmissive reflective plate is used in the cell in order to project an image using both the backlight and the external light as a light source. A metal thin film formed by a dry film forming technique such as a vacuum deposition method or a sputtering method is generally used as the semi-transmissive reflector. This metal thin film can be obtained by a method other than the dry film forming technique. For example, a method of forming a metal thin film by coating a metal fine particle dispersion paste in which metal fine particles are dispersed and then drying and firing (see, for example, Patent Document 1), or a solution containing a metal organic compound is coated and dried. This is a method of forming a metal thin film.

[0003]

[Patent Document 1] Japanese Unexamined Patent Publication No. 3-281783

The metal reflective film as described above is widely used in the field of decoration as a metal glossy film by utilizing its metallic luster. For example, decorative caps for cosmetics,
It is used in the design of automobile bumpers, automobile interior and exterior decorations, audio decorations, refrigerators, televisions and other home appliances. In the decoration and design fields, a method for forming a metal reflection film (metal luster film) on the surface of plastics includes vapor deposition using aluminum, silver, etc. or film formation by sputtering, chromium, gold, silver, nickel, etc. There are electroless plating and plating treatment using electrolytic plating, metal foil transfer, etc., and by forming a metal film of aluminum, silver, etc. on the surface of plastic by these methods, a metallic luster is given to the surface. .

[0005]

By the way, since the metal reflective film using the dry film forming technique in the conventional optical field described above is generally formed under reduced pressure, the apparatus is more suitable than the object to be formed. It will be very large. Therefore, when the object to be formed becomes large, there is a problem that the size and cost of the device cannot be avoided. There are also problems in terms of productivity and equipment costs. Especially, in a transmissive / reflective liquid crystal display, when a metal is made into a thin film, there is a characteristic absorption of the metal, and depending on the type of metal material used, red, blue, purple or other transmitted colors may occur. There was a problem in terms of color purity.

On the other hand, a good metal reflection film has not been obtained by any method other than the conventional dry film forming technique. For example, according to the conventional method of applying a paste containing fine metal particles, a conductive film can be obtained, but an excellent metal reflective film having a metallic luster characteristic of metal has not been obtained.
A method of fusing the metal fine particles in the coating film by heating after applying the metal fine particle dispersion paste is also proposed, but in this case, since heating at 150 ° C. or higher is required, use The substrates to be processed are limited, and there is a problem in terms of productivity and manufacturing cost.

Further, in forming a metallic glossy film in the conventional decoration field, a vacuum device is required when applying a metallic glossy film by a vapor deposition method or a sputtering method, and therefore a large-scale apparatus compared with an object to be processed. Therefore, there have been various problems such that a large amount of cost is required for the initial capital investment, and it is difficult to apply the metallic luster film to a large area or a complicated molded body. Further, when it is attempted to apply a glossy film by a plating treatment technique such as electrolytic / electroless plating, the number of steps increases as well as the number of steps is increased due to the multi-step plating process, which may adversely affect the human body or the environment. Often uses a drug. Recently, manufacturers of industrial products have become more interested in environmental problems, and in fields that place importance on environmental problems, such as manufacturers of electric machinery, automobiles, and precision equipment, avoid chemicals that may adversely affect the environment as much as possible. Is starting to appear.

Further, when aluminum foil or silver foil is transferred onto the surface of plastic, for example, when the subject to be transferred is a flat plastic plate or film, a simple transfer tool such as a hot stamp is used. It can be transferred in the transfer step. However, when the subject has a complicated shape, it is necessary to transfer the metal foil by the in-mold process, which complicates the process and increases the number of processes. Further, for a subject whose size is large, there is a problem in cost because the molding die becomes expensive.

The present invention has been made in order to solve the above problems, and a coating material for forming a metal reflection film, which can easily and inexpensively form a metal reflection film having an excellent metallic luster. An object is to provide a metal reflective film using the same and an article provided with the same.

[0010]

Means for Solving the Problems As a result of diligent studies, the present inventors have paid attention to the primary particle diameter of metal fine particles and the secondary particle diameter in a state of being dispersed in a coating material, and by controlling these, The inventors have found a coating material for forming a metal reflection film that can form a metal reflection film having an excellent metallic luster.

That is, the coating material for forming a metal reflection film of the present invention is characterized in that fine metal particles having an average primary particle diameter of 1 to 50 nm and an average secondary particle diameter of 50 to 200 nm are dispersed. To do.

The fine metal particles include precious metals, copper (Cu),
A material containing one or more selected from nickel (Ni) and aluminum (Al) is preferable. The noble metal is gold (Au), silver (Ag), platinum (Pt), palladium (Pd), rhodium (Rh), ruthenium (R).
u), osmium (Os), and iridium (Ir) are preferably selected from one or more kinds.

The metal reflective film of the present invention is characterized in that it is formed on a substrate using the coating material for forming a metal reflective film of the present invention. The metal reflective film preferably has a reflectance of 20 to 99%. The thickness is preferably 0.01 to 3 μm.

The article of the present invention is characterized by comprising the metal reflective film of the present invention.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the coating material for forming a metal reflective film of the present invention, the metal reflective film using the same, and an article provided with the same will be described. It should be noted that the present embodiment is specifically described for better understanding of the gist of the invention, and does not limit the present invention unless otherwise specified.

The metal reflective film-forming coating material of the present embodiment has metal primary particles having an average primary particle diameter of 1 to 50 nm and an average secondary particle diameter of 50 to 200 nm, a solvent, and optionally a binder. And a fine metal particle having a controlled particle diameter, which is uniformly dispersed in the paint. The above-mentioned metal fine particles have a mean primary particle diameter of 1 to 1 by using a known liquid phase reduction method and controlling the reaction conditions.
It can be controlled to 50 nm.

In the coating material for forming a metal reflection film of the present embodiment, metal fine particles having an average primary particle diameter of 1 to 50 nm are dispersed in the coating material so that the average secondary particle diameter becomes 50 to 200 nm. It is possible to realize a metal reflective film having excellent metallic luster and high reflectance. The reason why the coating film formed by this metal reflection film forming coating has a metallic luster is
By moving the free electrons of the metal in the coating film within the film,
This is because it reflects light in the visible light region.

Next, the coating material for forming a metal reflection film of this embodiment will be described in detail. In this coating for forming a metal reflection film, by using extremely fine metal fine particles having an average primary particle diameter of 1 to 50 nm, the filling rate of the metal fine particles in the film when formed into a coating film can be increased. Further, by controlling the average secondary particle diameter in the paint of the metal fine particles having an average primary particle diameter of 1 to 50 nm to be 50 to 200 nm, a structure in which the metal fine particles themselves are continuously connected can be formed in the coating film. Thus, free electrons can move around freely in the film. Therefore, a coating film having excellent metallic luster and high reflectance can be realized.

Here, the reason why the average secondary particle diameter in the paint of the metal fine particles is limited to 50 to 200 nm is that when the average secondary particle diameter is smaller than 50 nm, the bond between the metal fine particles when applied is small. This is because the range in which free electrons can move becomes small, so that the reflectance of the coating film is low and no metallic luster can be obtained. Further, when it exceeds 200 nm, the dispersion stability of the metal fine particles in the coating is lowered. In addition, the surface roughness of the coating film formed when the coating material is applied is increased, so that the proportion of diffused reflection in the reflected light is increased and excellent metallic luster cannot be obtained.

The component of the metal fine particles is not particularly limited, but considering the stability of the particles, for example, a noble metal,
Copper (Cu), Nickel (Ni), Aluminum (Al)
An alloy containing any one of the above or two or more thereof is suitable. Gold (A
u), silver (Ag), platinum (Pt), palladium (P
d), rhodium (Rh), ruthenium (Ru), osmium (Os), and iridium (Ir), or any one of these, or a noble metal alloy containing two or more of these is preferable. In particular, gold (Au), which is a material with high reflectance
And / or silver (Ag) is preferably contained.

As a method for controlling the secondary particle diameter of the metal fine particles, for example, heat treatment, salting-out treatment, ultraviolet (UV) treatment, electron beam (EB) treatment, poor solvent treatment, ultrasonic treatment and the like are preferable. Used for. In the present embodiment, when the fine metal particles are dispersed in the paint, electrostatic repulsion is used,
By removing components other than the metal fine particles as much as possible (for example, without using a dispersant), the direct bond between the metal fine particles when forming the coating film is promoted to further enhance the metallic luster and reflectance. You can also

When a dispersant is used, its components are not particularly limited, but organic carboxylic acids, organic amines, etc. can be used. As the organic carboxylic acid, for example, acetic acid, oxalic acid, succinic acid, malonic acid, phthalic acid, isophthalic acid, terephthalic acid, maleic acid, citric acid, tartaric acid and the like, and metal salts thereof can be used. As the organic amines, for example, alkanolamines such as dimethylaminoethanol, diethanolamine, propanolamine, butanolamine and the like can be used.

For the purpose of controlling dispersibility, for example,
Water-soluble polymers such as polyvinyl alcohol, polyvinylpyrrolidone, polyethylene glycol, polypropylene glycol and polyacrylic acid can also be used as a dispersion aid.

As the solvent used for the paint, for example,
Water, alcohols such as methanol, ethanol and 2-propanol, ketones such as acetone, methyl ethyl ketone and methyl isobutyl ketone, methyl cellosolve (β-
Oxyethyl methyl ether), ethyl cellosolve (β
-Oxyethyl ether), butyl cellosolve (butyl-β-oxyethyl ether), etc., aromatic hydrocarbons such as benzene, toluene, xylene, ethyl acetate, butyl acetate, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl Esters such as ether acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, diethylene glycol monomethyl ether acetate, and diethylene glycol monobutyl ether acetate are preferably used.

Among the above solvents, the solvent having a particularly high boiling point remains in the film after coating, and therefore has a great influence on the binding of the metal fine particles. For example, when a high boiling point solvent having a low compatibility with the dispersant to be used is used, the aggregation of the metal fine particles is promoted during the drying, so that a metal film having a high reflectance cannot be obtained. Therefore, when a high boiling point solvent that remains in the film after coating is used, it is necessary to select a solvent and a dispersant that do not cause aggregation of the metal fine particles.

The metal reflection film-forming coating material of the present embodiment does not necessarily require a binder component, but in order to secure the adhesion of the metal reflection film on the substrate, the reflectance is not impaired. A binder component may be added as appropriate. The binder component may be any as long as it does not inhibit the dispersion of the metal fine particles in the paint, and examples thereof include acrylic resin, polyester resin, polyurethane resin, polyolefin resin, polystyrene resin, cellulose, polyvinylpyrrolidone, polyvinyl alcohol, polyethylene glycol, polypropylene. Glycol, butyral resin,
Thermosetting or thermoplastic organic polymer compound such as alkyd resin, vinyl chloride resin, ultraviolet (UV) curable organic polymer compound, electron beam (EB) curable organic polymer compound, inorganic polymer compound such as polysiloxane Can be used alone or in combination.

At this time, in order to improve the adhesion and flexibility of the film, a trace amount of additives such as a crosslinking agent and a plasticizer may be added as appropriate. The addition amount of this binder is preferably 50% by weight or less with respect to the metal fine particles in the paint. This is because if the addition amount exceeds 50% by weight, the binding of the metal fine particles to each other during film formation is likely to be hindered, and it becomes difficult to obtain a film with high brightness.

The coating material for forming a metal reflection film is applied to the surface of a base material and then dried at a temperature which does not affect the base material, such as 80 ° C. or less, to obtain the metal reflection film of this embodiment. be able to. The substrate is, for example, a glass plate, a metal plate, a metal film, a plastic plate, a plastic film, etc., but is not particularly limited,
The coating material for forming a metal reflection film is suitable for an organic resin such as a plastic plate or a plastic film, because a metal reflection film can be obtained without heating.

The organic resin is not particularly limited, but for example, acrylonitrile-butadiene-styrene (ABS) resin, acrylic resin, polycarbonate (P
C) resin, polyester (PE) resin, polyethylene terephthalate (PET) resin, triacetyl cellulose (TAC) resin, polyolefin resin and the like. As a coating method, a commonly used coating technique such as a spray coating method, a spin coating method, a bar coating method, a dip coating method, a roll coating method, a reverse coating method, a flow coating method and a gravure printing method can be used.

When the coating material for forming a metal reflection film of this embodiment is used, the average primary particle diameter of the metal fine particles is 1 to 50 nm, and the average secondary particle diameter in the coating material is controlled to 50 to 200 nm. Therefore, excellent metallic luster can be obtained without heating after coating and drying. Of course, the metallic luster and stability may be further increased by heating.

In the metal reflective film of this embodiment, the film thickness is 0.
It is possible to control the reflectance and the transmittance by controlling the thickness between 01 and 3 μm. Therefore, it is possible to easily fabricate a semi-reflective film whose reflectance is controlled to a desired value, a semi-transmissive film whose visible light transmittance is controlled to a desired value, and the like.

For example, when the binder component is not included,
By controlling the film thickness between 0.01 and 3 μm, 2
A metal reflective film having a reflectance in the range of 0 to 99% can be obtained. Especially when the film thickness is 0.1 μm or more, 8
A reflectance of 0% or more is obtained. At that time, the transmittance is 20%
Less than Further, if the film thickness is 0.3 μm or more,
A reflectance of 90% or more is obtained. In addition, the film thickness is 0.01
When controlled between ~ 0.1 μm, the reflectance is 20-80%
A metal reflective film of is obtained, in which case the transmittance is 80 to 20%.
Becomes By combining this reflectance and transmittance,
A half mirror whose reflectance (or transmittance) can be arbitrarily set within the above range can be obtained. This half mirror can be applied to, for example, a reflector or a reflective electrode of a liquid crystal display (LCD).

In the case of a semi-transmissive film, its transmission color can be freely controlled by combining the metal fine particles themselves or adding a coloring material such as a dye or a pigment. When the coloring agent is added, the addition amount thereof is preferably 30% by weight or less, and particularly preferably 10% by weight or less based on the content of the metal fine particles. The reason for this is that if the addition amount exceeds 30% by weight, the bonding between metals is hindered, so that the reflectance decreases, the strength of the coating film deteriorates, and the deterioration of the reflectance and the deterioration due to long-term use increase. This is because the reliability of the reflective film is reduced.

Examples of the above colorants include organic pigments such as phthalocyanine blue, phthalocyanine green, cyanine blue, indanthrene blue, dioxazine violet, quinacridone, diketobipyrrolopyrrole, azo pigments, aniline black and alkali blue toner. , Titanium oxide, Chromium oxide, Iron black, Cobalt blue, Cerulean blue, Zinc chromate, Ultramarine, Navy blue, Manganese violet, Cobalt violet, Carbon black and other inorganic pigments, Azo dyes, Anthraquinone dyes, Indigoid dyes, Phthalocyanine dyes, Carbonium Dyes such as quinone imine dyes, methine dyes, quinoline dyes, nitro dyes, nitroso dyes, benzoquinone dyes, naphthoquinone dyes, naphthalimide dyes and perinone dyes are preferably used. .

Further, in order to improve the reflectance of the metal reflection film, a reflection enhancing layer utilizing an interference effect may be provided on the metal reflection film. The structure of the increased reflection layer may be a normal structure of the increased reflection layer, and a combination of the low refractive index layer and the high refractive index layer can be appropriately selected. In order to secure the film strength of the metal reflective film, a hard coat layer may be provided below or above the metal reflective film. As the hard coat layer, a coating film made of an ultraviolet (UV) curable resin, an electron beam (EB) curable resin, a thermosetting resin, a thermoplastic resin, an inorganic polymer compound such as polysiloxane is preferably used.

Further, the transmission color can be controlled by adding the above-mentioned coloring material to the reflection enhancing layer and the hard coat layer. As described above, in the metal reflection film of the present embodiment, the color tone of the metal reflection film can be adjusted by adding the above-mentioned coloring material to the metal reflection film forming coating material, the reflection increasing layer or the hard coat layer. it can. Therefore, when a semi-transmissive metal reflective film, which has been a problem in the conventional technique, is formed by a vapor phase method such as vacuum deposition or sputtering, it is impossible to add a coloring agent such as a pigment or a dye, so that a metal is used. It is possible to eliminate the point of having a unique color appearance.

This metal reflection film is used as a reflection film, a semiconductor device, various display devices such as a plasma display panel (PDP) and a liquid crystal display (LCD), a polarizing plate, a reflective electrode, a light guide plate, an optical disk, and a reflection for a copying machine. Articles with a metal reflection film whose reflectance (or transmittance) can be changed over a wide range by applying it to articles such as films, laser light detection mirrors, rear-view mirrors for projection televisions, and mirrors for reflective liquid crystal displays. Can be provided. When a transparent base material is used as the base material for forming the metal reflection film, the metal reflection film is thinly adjusted to produce a molded body or film provided with a semi-transmissive / semi-reflection film, that is, a half mirror. It is also possible.

When this metal reflective film is applied to the decorative field, the color tone becomes very important as well as the excellent metallic luster. The metal reflection film formed simply by using the fine metal particles has an excellent metallic luster, but its color tone (bright color) is almost limited to the color tone (bright color) peculiar to the metal. For example, even when silver fine particles, which are expected to have the highest brightness, are used, the luster color becomes gold or slightly greenish gold because the silver fine particles have a property of plasmon absorption. In particular, for decorative applications, the appearance color of the coating film is very important, and in order to meet the needs of the market, it is of course necessary to bring it closer to the natural silver color required in the decoration field, and to change the bright color according to the needs. Need to be adjusted.

In the metal reflective film of the present embodiment, the metallic gloss color of the resulting coating film can be adjusted by adding a binder component to the metal reflective film forming coating material. The reason is considered that, when the above-mentioned coating material for forming a metal reflection film is applied, interaction occurs between the metal fine particles contained in the coating material and the binder, and the fine arrangement of the metal fine particles changes. The type of the binder component is not particularly limited as long as it does not cause the metal fine particles to aggregate or does not use a solvent that causes the metal fine particles to aggregate, but a water-soluble polymer, a water-soluble polymer emulsion, a water-soluble polymer Dispersion is desirable. The amount of the binder added is preferably 0.1 to 50% by weight, more preferably 1 to 30% by weight, based on the metal fine particles in the coating material.

The binder component is preferably an organic polymer compound, for example, acrylic resin, polyester resin, polyurethane resin, polyolefin resin, polystyrene resin, cellulose, polyvinylpyrrolidone, polyvinyl alcohol, polyethylene glycol, polypropylene glycol, butyral resin, alkyd. Water-soluble polymers such as resins, water-soluble polymer emulsions, water-soluble polymer dispersions and the like can be used alone or in combination. As the above water-soluble polymer emulsion, for example, polyurethane emulsion, polyester emulsion, acrylic resin emulsion and the like are preferable.

When this binder component is added to the above-mentioned coating for forming a metal reflection film, a trace amount of an additive such as a crosslinking agent or a plasticizer is appropriately added in order to improve the adhesion and flexibility of the film. It doesn't matter. As described above, by adding the binder component to the above-mentioned coating material for forming a metal reflection film, a metal gloss film having an adjusted gloss color can be obtained.

Further, in the case of decorative use, when the reflectance is too high, the reflection of light on the metallic glossy film may be felt too tight, or the decorative article may give a strong impression. is there. In this case, it is possible to form a matte type metallic luster film by appropriately adjusting the metallic luster. As a method for delustering the metallic glossy film, for example, the surface of the base material is subjected to an etching treatment to roughen the surface before applying the metal reflection film forming coating material of the present embodiment to the base material, or a mat type Of the metallic luster film formed on the surface by roughening the surface by applying the above paint, or by applying a matte type paint to the surface of the metallic luster film. Further, it is possible to add a matte property by adding acrylic beads or the like to the metal reflective film forming coating material of the present embodiment. In addition, in the case of decorative use, if necessary, a pattern, a pattern, etc. may be formed on the metallic luster film by various methods, or a pearl pigment may be added to the upper layer portion to further enhance the decorative property and the design property. It is possible.

The coating material for forming a metal reflection film of this embodiment can be applied to a stamping foil such as a metal transfer foil as an alternative to metal vapor deposition. In the case of a metal transfer foil, it is necessary to form various layers such as a release layer, a coloring functional layer, a metal vapor deposition layer, and an adhesive layer on the film which is a base material. When forming each of these layers, it is possible to use an apparatus common to wet coating methods such as a die coating method, a gravure coating method, and a roll coating method, except for forming a metal vapor deposition layer. The layer requires a separate large device, such as a vacuum device, to perform metal deposition in the vacuum chamber. When the coating material for forming a metal reflection film of the present embodiment is used, since the metal reflection layer can also be formed by a series of wet coating methods, it becomes possible to form all the films in-line, It is possible to shorten the process and reduce the manufacturing cost. Therefore, it is possible to significantly reduce the cost of the product.

[0044]

EXAMPLES The present invention will be specifically described below with reference to Examples 1 to 13 and Comparative Examples, but the present invention is not limited to these Examples. [Preparation of Dispersion Liquid] The silver fine particle dispersion liquid (A) used in Examples 1 to 13 and the comparative example, the silver fine particle dispersion liquid (B) in which secondary particles are grown, and the palladium fine particle dispersion liquid are respectively subjected to the following methods. It was produced by.

[Synthesis of Silver Fine Particle Dispersion (A)] 90 g of 30% sodium citrate dihydrate aqueous solution, 128 g of 20% ferrous sulfate heptahydrate aqueous solution, and ion-exchanged water 625
g was mixed to form a solution. While maintaining this solution at 10 ° C., 157 g of a 10% aqueous silver nitrate solution was added to obtain a reddish brown ultrafine silver particle sol. This ultrafine silver particle sol was washed with water by centrifugation to remove impurity ions, and then ion-exchanged water was added to obtain a 20% by weight silver fine particle dispersion (A).

The average primary particle diameter of this silver fine particle dispersion (A) was measured by a transmission electron microscope (TEM) and found to be 5 to 10 nm. The average secondary particle diameter measured by the laser Doppler method was 20 nm.

"Synthesis of Silver Fine Particle Dispersion Liquid (B) Having Secondary Particles Grown" To 100 g of the silver fine particle dispersion liquid (A) obtained above, 100 g of butyl cellosolve was added, and the mixture was stirred at 25 ° C. for 24 hours, The fine silver particles in the dispersion liquid (A) were grown. The average primary particle diameter of the silver fine particle dispersion liquid (B) thus produced was measured by a transmission electron microscope (TEM) and found to be 5 to 10 nm. The average secondary particle size was measured by the laser Doppler method to be 156.
was nm.

[Preparation of Palladium Fine Particle Dispersion] 9927 g of ion-exchanged water was added to 55 g of a 3% palladium chloride aqueous solution, and 18 g of 1 wt% sodium borohydride was further added.
Was added to prepare a blackish brown ultrafine palladium particle dispersion. Next, impurity ions were removed from this palladium ultrafine particle dispersion liquid using an ion exchange resin, and then concentrated using a rotary evaporator to obtain a 10 wt% palladium fine particle dispersion liquid.

The average primary particle diameter of this palladium fine particle dispersion was measured by a transmission electron microscope (TEM) and found to be 5 nm. The average secondary particle diameter measured by the laser Doppler method was 22 nm.

[Formation of Metal Reflective Film] Using the above dispersion liquid, metal reflective films of Examples 1 to 5 and Comparative Example were prepared. "Example 1" Silver fine particle dispersion liquid (B) in which secondary particles were grown 25 wt% 2-propanol 20 wt% Ethyl cellosolve 20 wt% Ethanol 35 wt% were mixed, and then uniformly dispersed by an ultrasonic disperser. A coating material A for forming a metal reflection film was obtained.

The average secondary particle diameter of the silver fine particles in the coating material A for forming a metal reflection film was 150 nm. This coating material A for forming a metal reflection film was applied onto a polyethylene terephthalate (PET) film using a coating machine (wire bar # 14), and then dried at 80 ° C. for 3 minutes to form a metal reflection film. The film thickness of this metal reflective film was 0.3 μm.

[Example 2] Silver fine particle dispersion liquid (B) on which secondary particles are grown 17 wt% 2-propanol 20 wt% Ethyl cellosolve 20 wt% Ethanol 43 wt% are mixed, and then uniformly dispersed by an ultrasonic disperser. By doing so, a coating material B for forming a metal reflection film was obtained.

The average secondary particle diameter of the silver fine particles in this coating material B for forming a metal reflection film was 150 nm. This coating material B for forming a metal reflection film was applied onto a polyethylene terephthalate (PET) film using a coating machine (wire bar # 14), and then dried at 80 ° C. for 3 minutes to form a metal reflection film. The film thickness of this metal reflective film was 0.1 μm.

[Example 3] Silver fine particle dispersion liquid (B) in which secondary particles were grown 12.5 wt% 2-propanol 20 wt% ethyl cellosolve 20 wt% ethanol 47.5 wt% were mixed, and then ultrasonic waves were applied. By uniformly dispersing with a disperser, a metal reflection film forming coating material C was obtained.

The average secondary particle diameter of the silver fine particles in this coating material C for forming a metal reflection film was 148 nm. This coating material C for forming a metal reflection film is applied onto a polyethylene film using a coating machine (wire bar # 14), and then at 80 ° C. for 1 hour.
It was dried for a minute to form a metal reflection film. The film thickness of this metal reflective film was 0.05 μm.

[Example 4] Silver fine particle dispersion liquid (B) on which secondary particles are grown 10 wt% Palladium ultrafine particle dispersion liquid 2.5 wt% 2-Propanol 20 wt% Ethyl cellosolve 20 wt% Ethanol 47.5 wt% Was mixed and then uniformly dispersed by an ultrasonic disperser to obtain a coating D for forming a metal reflection film.

The average secondary particle diameter containing the silver fine particles and the palladium fine particles in the coating material D for forming a metal reflection film is 13
It was 8 nm. This coating material D for forming a metal reflection film was applied onto a polyethylene terephthalate (PET) film using a coating machine (wire bar # 14), and then dried at 50 ° C. for 1 minute to form a metal reflection film. The film thickness of this metal reflective film was 0.04 μm.

[Example 5] Silver fine particle dispersion liquid (B) in which secondary particles are grown 10 wt% Phthalocyanine-based green pigment dispersion liquid 1 wt% 2-propanol 20 wt% Ethyl cellosolve 20 wt% Ethanol 49 wt% are mixed, and then mixed. By uniformly dispersing with an ultrasonic disperser, a metal reflection film forming coating material E was obtained.

The average secondary particle diameter of the fine silver particles in the coating material E for forming a metal reflection film was 187 nm. The coating material E for forming a metal reflection film was applied onto a polyethylene terephthalate (PET) film using a coating machine (wire bar # 14), and then dried at 50 ° C. for 1 minute to form a metal reflection film. The film thickness of this metal reflective film was 0.05 μm.

Comparative Example Silver fine particle dispersion liquid (A) 12.5 wt% 2-propanol 20 wt% Ethyl cellosolve 20 wt% Ethanol 35 wt% are mixed, and then uniformly dispersed by an ultrasonic disperser. A coating material F for forming a metal reflection film was obtained.

The average secondary particle diameter of the silver fine particles in this coating material F for forming a metal reflection film was 35 nm. This coating material F for forming a metal reflection film was applied onto a polyethylene terephthalate (PET) film using a coating machine (wire bar # 14) and then dried at 50 ° C. for 1 minute to form a metal reflection film. The film thickness of this metal reflective film was 0.04 μm.

"Evaluation" Examples 1 to 5 obtained by the above
And each evaluation item of the transmittance, visible light reflectance, and transmitted color of the metal reflection film of each of the comparative examples was evaluated using the following methods or devices. (Transmittance) Tokyo Denshoku "Automatic Haze Meter H III
The transmittance of the metal reflection film itself was measured using "DP".

(Visible light reflectance) The reflectance at a wavelength of 380 to 780 nm was measured using "a spectrophotometer U-3400" manufactured by Hitachi, Ltd. with an aluminum vapor deposition film as a control, and the average visible light reflectance was calculated. did.

(Transmission color) Hitachi spectrophotometer "Spectrophotometer U"
-3400 "was used to determine the coating film color value (CIE1976). (Colors a *, b * of transmitted colors in the visible light region
When the value of is close to 0, the transmitted color becomes blackish. In addition, when a * is in the negative region, the human eye has a bluish black color that most strongly feels the blackness, and the hue of the transmitted image becomes clear. ) Table 1 shows the evaluation results.

[0065]

[Table 1]

From the results of Table 1, it was confirmed that the metal reflective films of Examples 1 to 5 had a high visible light reflectance of 55 to 90% and an excellent metallic luster. . It was also confirmed that these metal reflective films were excellent in transmitted color. In particular, excellent transmission color was obtained by combining two kinds of metals in Example 3 and by combining pigments in Example 4. On the other hand, in the comparative example, the visible light reflectance was as low as 19%, and the function as a reflective film was deteriorated. Further, the gloss of the film was insufficient and far from the metallic gloss. In addition, the transmitted color becomes more bluish, and there is a problem in terms of color purity.

[Production of Article with Metallic Reflective Film] Using the above dispersions, articles with metallic reflective film of Examples 6 to 8 were produced. "Example 6" Silver fine particle dispersion liquid (B) in which secondary particles are grown 25 wt% 2-propanol 20 wt% 1-methoxy-2-propanol 20 wt% Polyester emulsion 1 wt% (Vylonal MD1100: manufactured by Toyobo Co., Ltd.) Ethanol 34 wt %, And then uniformly dispersed by an ultrasonic disperser to obtain a coating material G for forming a metal reflection film.

The average secondary particle diameter of the fine silver particles in this coating material G for forming a metal reflection film was 88 nm. The coating material G for forming a metal reflection film was applied onto an ABS resin molded body by a spray coating method, and then dried at 50 ° C. for 1 minute to obtain a metal reflection film. The film thickness of this metal reflective film was 0.3 μm. From the above, an ABS resin molded product with a metal reflective film having good metal glossiness was obtained.

[Example 7] PE having a release layer formed on the surface
A T film was prepared, and Example 6 was placed on this PET film.
Coating machine G for coating metal reflective film (of wire bar # 1
4) and then dried at 50 ° C. for 1 minute to form a metal reflective film having a thickness of 0.3 μm. Then
An adhesive layer was further formed on this coating film to obtain a transfer film. Next, this transfer film was transferred onto an acrylic plate to prepare an acrylic plate having a metal reflection film. As described above, by using the transfer film of Example 7, a metal reflection film having an excellent reflection function could be formed on the acrylic plate.

“Example 8” Silver fine particle dispersion liquid (B) having secondary particles grown thereon 10 wt% 2-propanol 20 wt% 1-methoxy-2-propanol 20 wt% Polyester emulsion 0.4 wt% (Vylonal MD1100: Toyobo) Pure water 15 wt% ethanol 34.6 wt% were mixed, and then uniformly dispersed by an ultrasonic disperser to obtain a metal reflection film forming coating material H.

The average secondary particle diameter of the silver fine particles in this coating material H for forming a metal reflection film was 75 nm. The coating material H for forming a metal reflection film was applied on an acrylic plate by a dip coating method and then dried at 50 ° C. for 1 minute to obtain a metal reflection film. The film thickness of this metal reflective film was 0.03 μm. As described above, an acrylic plate with a half mirror having a transmittance of 30% and a reflectance of 58% was obtained.

[Formation of metallic luster tone glitter film] Using the above dispersions, metallic luster tone glitter films (metal reflection films) of Examples 9 to 13 were formed. "Example 9" Silver fine particle dispersion liquid (B) in which secondary particles are grown 25 wt% Polyurethane emulsion 1 wt% (CG-5010: Dainippon Ink and Chemicals, Inc.) N-methyl-2-pyrrolidone 1 wt% 2-propanol 63 wt % Ethyl Cellosolve 10 wt% was mixed, and then uniformly dispersed by an ultrasonic disperser to obtain a coating material J for forming a metal reflection film.

The average secondary particle diameter of the silver fine particles in this coating material J for forming a metal reflection film was 85 nm. This coating material J for forming a metal reflection film is applied on a polyethylene terephthalate (PET) film by using a coating machine (wire bar # 14), and then dried at 50 ° C. for 1 minute to form a bright film having a metallic luster tone. did. The thickness of the metallic luster-like bright film was 0.35 μm.

[Example 10] Silver fine particle dispersion liquid (B) in which secondary particles are grown 25 wt% Polyester emulsion 1 wt% (KZA-0134: Unitika Ltd.) N-methyl-2-pyrrolidone 1 wt% 2-propanol 63 wt % Ethyl cellosolve 10 wt% was mixed, and then uniformly dispersed by an ultrasonic disperser to obtain a coating K for forming a metal reflective film.

The average secondary particle diameter of the silver fine particles in this coating material K for forming a metal reflection film was 125 nm. The coating material K for forming a metal reflection film is applied on a polyethylene terephthalate (PET) film by using a coating machine (wire bar # 14), and then dried at 50 ° C. for 1 minute to form a bright film having a metallic luster tone. did. The film thickness of this metallic luster-like bright film was 0.33 μm.

[Example 11] Silver fine particle dispersion liquid (B) in which secondary particles are grown 25 wt% Aqueous butyral resin 1 wt% (ESREC KX-5: Sekisui Chemical Co., Ltd.) N-methyl-2-pyrrolidone 1 wt% 2-Propanol 63 wt% Ethyl cellosolve 10 wt% was mixed, and then uniformly dispersed by an ultrasonic disperser to obtain a coating L for forming a metal reflective film.

The average secondary particle diameter of the silver fine particles in the coating material L for forming a metal reflection film was 95 nm. The coating material L for forming a metal reflection film is applied on a polyethylene (PE) film using a coating machine (wire bar # 14), and then 5
It was dried at 0 ° C. for 1 minute to obtain a metallic luster tone glittering film.
The film thickness of this metallic luster-like bright film was 0.32 μm.

Example 12 Silver fine particle dispersion liquid (B) in which secondary particles are grown 25 wt% Acrylic resin emulsion 1 wt% (Boncoat 550: Dainippon Ink and Chemicals, Inc.) N-methyl-2-pyrrolidone 1 wt% 2 -Propanol 63 wt% Ethyl cellosolve 10 wt% were mixed, and then uniformly dispersed by an ultrasonic disperser to obtain a coating M for forming a metal reflective film.

The average secondary particle diameter of the silver fine particles in this coating material M for forming a metal reflection film was 110 nm. The coating material M for forming a metal reflection film was applied onto a polyethylene (PE) film by using a coating machine (wire bar # 14), and then dried at 50 ° C. for 1 minute to obtain a bright film having a metallic luster tone. The thickness of the metallic luster-like bright film was 0.28 μm.

Example 13 Silver fine particle dispersion liquid (B) having secondary particles grown thereon 25 wt% Polyvinylpyrrolidone 1 wt% N-methyl-2-pyrrolidone 1 wt% 2-propanol 63 wt% Ethyl cellosolve 10 wt% were mixed, Then, the coating material N for forming a metal reflection film was obtained by uniformly dispersing it with an ultrasonic disperser.

The average secondary particle diameter of the silver fine particles in this coating material N for forming a metal reflection film was 105 nm. The coating material N for forming a metal reflection film was applied on a polyethylene (PE) film using a coating machine (wire bar # 14), and then dried at 50 ° C. for 1 minute to obtain a bright film having a metallic luster tone. The thickness of the metallic luster-like bright film was 0.25 μm.

"Evaluation" Examples 9 to 1 obtained by the above
Each of the evaluation items of the light brightness, the gloss color, and the adhesiveness of the metallic luster tone glittering film of No. 3 were evaluated using the following methods or devices. A. Light Luminance (Visual) Visual luminosity was judged. Here, when a fluorescent lamp was projected as a subject on the glitter film, it was judged as "○" when the fluorescent lamp image was clearly reflected, and "X" when the fluorescent lamp image was not reflected clearly. .

(Visible light reflectance) The reflectance at a wavelength of 380 to 780 nm was measured using "a spectrophotometer U-3400" manufactured by Hitachi, Ltd. with an aluminum vapor deposition film as a control, and the average visible light reflectance was calculated. did.

B. Gloss color (visual inspection) The gloss color was visually evaluated. (Color value) Using a color analyzer (TC-1800MKII: manufactured by Tokyo Denshoku Gijutsu Center Co., Ltd.), the color value of the reflected light was determined with a white plate as a control. The closer the a * and b * values are to 0,
It becomes a white or silvery glossy color, and when the a * value increases, it becomes a reddish glossy color, and when the b * value increases, it becomes a yellowish glossy color.

C. Adhesion cross-cut test (Japanese Industrial Standard "JIS K 540
Adhesion of each glittering film was evaluated according to “0”). Here, first, 100 grids were prepared by making 11 cuts in the length and width at 1 mm intervals on the formed glitter film, and then a commercially available cellophane tape was attached to the surface, and this cellophane tape was used. Rubbing with a plastic spatula, making sure it is in close contact, and then peeling off at once
The test was repeated once and again, and when 100 grids were not peeled at all, it was judged as "O", and when even one was peeled, it was judged as "X". The above evaluation results are shown in Table 2.

[0086]

[Table 2]

From the results shown in Table 2, it was found that the metallic luster tone glittering films of Examples 9 to 13 could be variously changed in color tone by selecting the binder component. Further, it was also found that since the visible light reflectance is 30 to 43%, the light intensity of the reflected light is weakened by the glitter film, and there is no fear that the reflection of the light on the glitter film is too tight.

[0088]

As described above, according to the coating material for forming a metal reflective film of the present invention, the average primary particle diameter is 1 to 50 nm.
Since the metal fine particles having an average secondary particle diameter of 50 to 200 nm are dispersed, an excellent metal can be obtained by controlling the primary particle diameter of the metal fine particles and the secondary particle diameter in a state of being dispersed in the coating material. It is possible to easily form a metallic reflective film having gloss at low cost.

According to the metal reflective film of the present invention,
Since it was formed using the metal reflective film forming coating material of the present invention,
The surface of the metal reflective film can have an excellent metallic luster,
The reflection characteristics of visible light can be improved.

According to the article of the present invention, since the article is provided with the metal reflection film of the present invention, it is possible to impart an excellent metallic luster to the article and improve the reflection characteristic of visible light.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Ken Uehara             28 Sumitomo Osaka, 6-6 Rokubancho, Chiyoda-ku, Tokyo             Inside Cement Co., Ltd. (72) Inventor Atsumi Wakabayashi             28 Sumitomo Osaka, 6-6 Rokubancho, Chiyoda-ku, Tokyo             Inside Cement Co., Ltd. F-term (reference) 4D075 BB92Z CB04 CB13 DA04                       DA06 DB01 DB13 DB33 DB35                       DB36 DB37 DB43 DB48 DC13                       DC18 DC21 DC24 DC27 DC38                       EA06 EA10 EB07 EB13 EB14                       EB15 EB22 EB35 EB37 EB38                       EC10 EC53                 4J038 AA011 HA061 KA20 MA06                       PB08 PB11

Claims (7)

[Claims] 1. An average primary particle diameter of 1 to 50 nm,
A coating material for forming a metal reflection film, characterized in that fine metal particles having an average secondary particle diameter of 50 to 200 nm are dispersed. 2. The coating material for forming a metal reflection film according to claim 1, wherein the metal fine particles contain one kind or two or more kinds selected from a noble metal, copper, nickel and aluminum. 3. The metal reflective film formation according to claim 2, wherein the noble metal is one or more selected from gold, silver, platinum, palladium, rhodium, ruthenium, osmium, and iridium. Paint. 4. A metal reflective film, which is formed on a base material by using the coating material for forming a metal reflective film according to claim 1, 2 or 3. 5. The metal reflective film according to claim 4, which has a reflectance of 20 to 99%. 6. The metal reflective film according to claim 4, which has a thickness of 0.01 to 3 μm. 7. An article comprising the metal reflection film according to claim 4, 5, or 6.