JPS62176840A - Transparent conductive film - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an easily slippery transparent conductive film.

[Conventional technology]

Conventionally, transparent conductive films have been produced by coating a base film with antimony or other conductive inorganic particles using acrylic or other bangs, or by kneading conductive fibers such as copper or carbon fiber into the film. There have been known methods of manufacturing such as by coating a resin or laminating a film on a non-woven fabric that is conductive, and by forming a thin metal film on the surface of the film using methods such as vapor deposition or sputtering.

[Problem that the invention seeks to solve]

However, when applying conductive inorganic particles, the coating must be at least 3 μm, preferably 5 μm or more, in order to provide sufficient conductivity, making it quite expensive and significantly thicker, making it compact. There are disadvantages such as not being able to

Furthermore, when conductive fibers or nonwoven fabrics are used, there is a drawback that variations in conductivity inevitably increase if transparency is to be maintained. On the other hand, when a metal thin film is formed on the surface by a method such as vapor deposition or sputtering, it becomes expensive and has the disadvantage of lacking slipperiness.

An object of the present invention is to provide a transparent conductive film that does not have the above-mentioned drawbacks, that is, has excellent slipperiness.

, [Means for Solving the Problems] The transparent conductive film of the present invention comprises a swellable inorganic layered silicate (A) coated with a conductive metal on at least one surface of a plastic film, and a water-soluble resin (B). ) weight ratio (A/B
) A layer obtained from a mixture of 1/100 to 2/1 is provided.

As the base material of the plastic film in the present invention,
Any known appropriate plastic film may be used, regardless of whether it is a single film, a composite film, stretched or unstretched. Typical examples include polyolefin film, polystyrene film, polyester film, polycarbonate film, triacetyl cellulose film, cellophane film, polyamide film, polyimide film, polyphenylene sulfide film, polyetherimide film, and polyether sulfone film. , Holly Sulfone Film, and Holly Acrylic. Among these, polyester film (%Kffi elongation, TAFILM), polyethylene film, polypropylene film, or nylon film alone or in composites are preferable because they have small thermal dimensional changes, high rigidity, and low cost. be. The thickness of the plastic film is not particularly limited, but it is usually 0.5 μm or more and 500 μm or less,
From the viewpoint of coating properties, a thickness of 2 μm or more and 250 Pn or less is particularly preferable. When using a composite film, the number of layers or the method is not particularly limited, but usually a composite extrusion method, an extrusion lamination method on a base film,
Alternatively, a lamination method using various adhesives may be used, and if stretching is required, the composite may be performed before or after stretching.

Furthermore, when the base material is a plastic film mixed with commonly used antistatic agents such as glycol ether, alkyl amine, or alkyl betaine, or a composite of a film mixed with these and a film without these mixed, Furthermore, since the conductivity is improved, it is more suitable.

The essence of the present invention is to provide on such a plastic film a layer obtained from a mixture of a swellable I-form inorganic silicate coated with a conductive metal and a water-soluble resin. Here, the term "swellable inorganic layered silicate" refers to an inorganic layered silicate that has the property of "swelling" by coordinating water between the layers, and this swelling property is utilized in the coating layer of the conductive film of the present invention. Its essence is that it exists in the form of fine particles formed at least partially by interlayer separation.

Structurally, the swellable inorganic layered silicate used in the present invention is a 5 kOa tetrahedral phyllosilicate with a theoretical Si to O ratio of 2:5, and has a crystal structure in which the crystal unit cell is repeated in the thickness direction. A typical example thereof can be expressed as a chemical formula as follows.

W(1,3-1,I X1s-az (S i a, s
~ts 01 o ) Z IJ#L2 where W: is a glabellar ion and is one or more cationic ions.

X: ion at octahedral position, Mg2+ or Mg2
+ part of Li”, Fe2+, Ni”, Mn”, At3
An ion substituted with at least one ion selected from the group consisting of + and F.

O: Oxygen Z: F″″ or 0) (1 building or 2s selected from -
ion.

In addition, in the present invention, Sl at the above-mentioned tetrahedral position is Ge
Alternatively, a part of these may be replaced with At % Fe1B or the like, and the swellable inorganic layered silicate referred to in the present invention also includes these.

Specific examples of these include clay-based and mica-based minerals, such as natural products such as montmorillonite and vermiculite, and synthetic products such as tetrasilicic mica, taeniolite, and hectorite, which are synthesized by melting or hydrothermally and having the general formula above. There is.

Among these, synthetic materials are particularly preferred because they contain few impurities and have a uniform composition, resulting in uniform crystals.Among them, W is preferred because it has excellent crystal flatness and a large crystal size. >c-o, t-x+oIMg 1B -? 3.2-X
L i x (S i s, 5-tooto) F
t, s-t.

or Wx-0,1-X+Q, I Mg 1g -X-a
, z -XL iX (S i s, b-co Oto
) (OH) 1.8-40 (x = 0.8
~+1.2) is preferred.

Further, the interlayer ions W are not particularly limited as long as they are one or more cationic ions, but since a stable sol is obtained, 50% or more of the total number of interlayer ions is preferably 8
0% or more, more preferably 95% or more is R-NH3+
(However, R represents an alkyl group, preferably an alkyl group having 7 or less carbon atoms) or one or more ions selected from Li+ and Na+.

The size of the swellable inorganic layered silicate used in the present invention is not particularly limited, but the average particle size measured by a sedimentation method is 0.05/jm to 15 μm, preferably 0.05/jm to 15 μm.
1 pIn ~8 μm, more preferably 0.15 μm ~
A thickness in the range of 3 μm is preferable because a uniform layer can be obtained. In addition, when the thickness of all particles is 50 cm, preferably 80 cm, more preferably 90% of the thickness is 800 λ or less, preferably 40 o'i or less, and even more preferably 100 λ or less, the coating layer surface is smooth and the product is more compact. It is preferable to become.

In the present invention, particles obtained from such a swellable inorganic layered silicate are used in a state coated (plated) with a conductive metal. In this case, 60% or more of the surface area of the silicate particles,
Preferably 80% or more, more preferably 90% or more, of the conductive metal is required to be coated. Covered J! 1
This is because if the thickness is 2λ8 or more, transparency cannot be ensured.

Examples of the conductive metal include, but are not limited to, nickel, chromium, copper, gold, silver, and palladium.

As the coating method, that is, the plating force method, electrolytic plating, chemical plating, vapor deposition, sputtering, etc. can be used, but the chemical plating method is particularly preferable because it allows plating in a state in which the particles are suspended.

Chemical plating can be performed by known methods such as electroless nickel plating and electroless chrome plating.

The water-soluble resin as used in the present invention is essentially any resin that exhibits water solubility when forming a coating liquid and is a polymer (crosslinked polymer or non-crosslinked polymer) in the coating layer of the final coating film. Either is fine. In terms of structure, organic polymers or polymer-forming substances having one or more highly hydrophilic polar groups as shown below are preferable.

Nonionic: -OH, -0-1-CN, -CONH
z Typical water-soluble resins include silane coupling agents,
Examples include titanium coupling agents, resins such as water-soluble acrylic, water-soluble polyester, water-soluble polyamide, polyvinyl alcohol, polyacrylamide, polyethylene oxide, vinyl acetate copolymer, polyvinylpyrrolidone, and mixtures thereof.

The water-soluble resin used in the present invention has a softening temperature after dehydration and drying of at least 50°C, preferably at least 80°C, more preferably at least 120°C, at least 50% by weight, preferably at least 80°C.
It is preferable that it accounts for 90% by weight or more, more preferably 90% by weight or more. It goes without saying that curable resins are preferably used. These resins are preferably selected depending on the base film used. For example, when polyester is used as the base material, silane coupling agents, titanium coupling agents, water-soluble acrylic, and water-soluble polyester are suitable from the viewpoint of adhesive properties. When polyolefin is used as the base material, titanium coupling agents, silane coupling agents, and water-bath acrylics are suitable from the viewpoint of adhesive properties.

When the base material is polyphenylene sulfide, polyether ether ketone, polysulfone, polyether sulfone, or polyimide, silane coupling agents and titanium coupling agents are suitable.

Typical examples of silane coupling agents include amine-based silane coupling agents, vinyl-based or methacryloxy-based silane coupling agents, epoxy-based silane coupling agents, methyl-based silane coupling agents, chloro-based silane coupling agents, and anilino-based silanes. Examples include coupling agents and mercapto-based silane coupling agents. The silane coupling agent may be appropriately selected depending on the type of base material, and examples include polyethylene terephthalate,
When applying to a polyester base material such as polycarbonate, an epoxy-based silane coupling agent with a structure similar to It is particularly suitable from the viewpoint of adhesiveness.

[However, m=ot or engineering, n=an integer from 1 to 10, R'
= Hydrocarbon residue selected from alkyl groups having 1 to 10 carbon atoms, phenyl groups, and cyclohexyl groups, R'' = = Hydrocarbon residue selected from hydrogen or alkyl groups having 1 to 10 carbon atoms] .

Furthermore, when a polyolefin resin is used as the base material, an epoxy silane coupling agent having the same structure as shown above is suitable.

A typical example of a water-soluble polyester is a polyester containing at least 2 polyethylene glycols with a degree of polymerization of 2 to 10.
A copolymer of about 8 mole or more of a sulfonic acid metal salt compound having 0 mole and an ester-forming bifunctional group, or the molar ratio of the aromatic dicarboxylic acid component and the aliphatic dicarboxylic acid component is 10/1 to 1/10. In a polyester copolymer consisting of a dicarboxylic acid and/or its ester-forming derivative and glycol, A: 3 to 10 mol of an ester-forming sulfonic acid alkali metal salt compound to the total acid component; B: 1.4-bis of the glycol component; (Hydroxyalkoxy)benzene component in a composition ratio of 5 to 60 molar or aromatic dicarboxylic acid component and saturated linear aliphatic dicarboxylic acid component having 4 to 8 methylene groups in a molar ratio of 10/1 to 10.
/7.5 in a polyester copolymer consisting of dicarboxylic If and/or its ester-forming derivative and glycol, A, the ester-forming sulfonic acid alkali metal salt compound is 3.5 to 7.5 to the total acid component. Morti B contains 30% diethylene glycol among the glycol components.
Examples include those having a composition ratio of 20 to 10,001) m as the amount of phosphorus in the phosphorus compound relative to the polyester.

When polyester is used as a base material, from the viewpoint of coating properties and adhesive properties, a dicarboxylic acid in which the molar ratio of aromatic dicarboxylic acid, "Jb, and aliphatic dicarboxylic acid component is 10/1 to 1/10. and/or in a polyester copolymer consisting of its ester-forming dicenter and glycol, A: 3 to 10 mol of the ester-forming alkali metal sulfonic acid salt compound to the total acid component; B: 1,4-bis( (hydroxyalkoxy)benzene component in a composition ratio of 5 to 60 molar, or the molar ratio of an aromatic dicarboxylic acid component and a saturated linear aliphatic dicarboxylic acid component having 4 to 8 methylene groups to be 10/1 to 10.
/7.5 in a polyester copolymer consisting of dicarboxylic acid and/or its ester-forming derivative and glycol. B. Of the glycol components, diethylene glycol is 30%
It is preferable that the polyester has a composition ratio of 20 to 11,000 ppm as the amount of phosphorus in the phosphorus compound based on the polyester.

In the present invention, a metal-coated inorganic layered silicate (
4) and water-soluble resin (B) at a weight ratio (A/B) of 1/1.
It is necessary to mix at a ratio of 00 to 2/1. This is 1/100
If it is too small, the conductivity will be poor, which is undesirable, and if it is larger than 2/1, it will be undesirable because folds will form relatively easily between the layers.

The layer consisting of a mixture of a metal-coated inorganic layered silicate and a water-soluble resin may contain other components within the range that does not impair the properties of these essential components, but usually the above components are 60% by weight.
or more, preferably 80% by weight or more, more preferably 90% by weight or more
It is used so that the weight is - or more.

In the present invention, the inorganic coating layer is coated on one or both sides of the plastic film, either entirely, in stripes, or partially.

The thickness of the inorganic coating layer in the present invention is not particularly limited, but is usually 3 μm or less, preferably 2 μm or less,
More preferably 1 μ [n or less, particularly preferably 0.5 μ
“N or less is 0.01 μm or more.

Next, a typical method for manufacturing the transparent conductive film of the present invention will be described, but the method is not limited thereto.

First, prepare a plastic film as a base material. This film may be subjected to corona discharge treatment in air or other various atmospheres, if necessary. Anchor treatment may be performed using a known anchor treatment agent such as urethane resin or epoxy resin, but this is usually not necessary.

On the other hand, a swellable inorganic layered silicate is added to a suitable solvent (dispersion medium) such as water or alcohol to obtain a non-agglomerated dispersion which is finely divided by utilizing its swelling property, and then as described above. Metal plating treatment and addition of water-soluble resin. The coating liquid thus obtained is coated using a conventional method such as gravure coating, reverse coating, or spray coating, and then dried at 60° C. to 250° C. for about 1 sec to 15 minutes. The solvent is not particularly limited, but water or alcohol is usually used as described above. Of course, a mixed solvent of water and alcohol may also be used. Although the coating layer may be separately formed and laminated later, it is preferable to coat the inorganic coating layer of the present invention directly onto the base film since the inorganic coating layer of the present invention is somewhat insufficient in strength.

[Action/effect of the invention]

In the present invention, since a swellable inorganic layered silicate is used, a conductive film of good quality can be obtained by simply providing an extremely thin layer.

More specifically, it is possible to obtain stable conductivity that does not change with time or humidity, has excellent transparency, and also has excellent slipperiness and antistatic properties.

In terms of slipperiness, the static friction coefficient of the coating surface is 0.5.
Below, in particular, those below 0.45 can be easily obtained. As for antistatic properties, the surface resistivity is 10 regardless of whether it is dry or not.
A resistance of 7 Ω or less, particularly 10 6 or less, and even 10 5 or less can be easily obtained.

In order to exhibit such excellent properties, the film of the present invention has I
It is suitable for use in C packages, labels, etc.

[Characteristics measurement method and wear evaluation criteria]

In addition, the measuring method and evaluation criteria of the characteristics in the present invention are as follows.

(1) Surface specific resistance: A sample left in a room at 20°C and 65% RH for 8 hours (shown as room temperature) and a sample dried in a 1201 vacuum dryer (shown as after drying) using a super megohmmeter. It was measured using

(2) Haze: Measured according to ASTM-D-1003-61.

(3) Peel the coating layer mainly composed of adhesive inorganic layered silicate onto a commercially available cellophane adhesive tape (manufactured by Chiban Co., Ltd.) for 90', and after peeling, the adhesion area of the inorganic coating layer on the cellophane tape is 40%. If the adhesion strength to the base material is less than 40 inches, the adhesive strength to the base material is "○", and if it is 40 inches or more, it is "○".
×”.

(4) Static friction coefficient μs: ASTM-D-1894B
-63, it was measured using a slip tester.

〔Example〕

Next, embodiments of the present invention will be described based on Examples.

(Plating treatment of layered silicate) 2 w%v% 1i! Suspension of silicates (below) 50
0d, palladium chloride 1'WAI% solution 50-total 50
- Allowed to react for 10 minutes. Thereafter, the solution was heated to 90° C., nickel sulfate 5 Q w%v % solution 100Ω was added thereto, stirred and reacted, and nickel plated.

Examples 1-3. Comparative Examples 1 and 2 A protective layer having the following composition was applied on one side of a polyethylene terephthalate biaxially stretched film with a thickness of 12 μm to a thickness of 0 after drying.
．． After coating in a 5% by weight sol state to a thickness of 3 μm, 1
Dry in hot air at 65°C for 2 minutes. These samples and base films were evaluated and the results shown in the table were obtained.

(Protective layer composition) Layered silicate (A): NaMg2Li (S i<
Ole )F is abbreviated as Na-TN. This nickel plated product was used.

Water-soluble resin (B): A water-soluble copolyester containing 80 moles of terephthalic acid and 15 moles of 5-sulfondium isophthalic acid as the acid component, and ethylene glycol as the glycol component.

However, the composition ratio is shown in the table.

As shown in the table, if the amount of layered silicate is too small, both surface resistivity and antistatic properties will be insufficient, which is not preferable. On the other hand, if the amount is too large, the adhesive strength will be poor and practicality will be lacking, which is not preferable.

Only within the range of the present invention will a film with well-balanced thickness be obtained.

Example 4. Comparative Example 3 Evaluation was conducted under the same conditions as in Example 1, except that the water-soluble resin was changed to . At the same time, only the base film was evaluated. As shown in the table, it is possible to obtain good results within the range of the present invention. On the other hand, only the base film can provide completely insufficient quality.

Claims (1)

[Claims] (1) Weight ratio (A/B) of swellable inorganic layered silicate (A) coated with conductive metal on at least one surface of plastic film and water-soluble resin (B) 1/100 to 2/1 A transparent conductive film comprising a layer obtained from a mixture of.