JPS5963613A - Laminated conductor - 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 The present invention relates to a laminated conductor, and particularly to a planar conductor that has good resistance value stability in a high resistance region and less variation.

Various metals have been widely used as conductors for a long time, but with the advancement of science and technology in recent years, the demand for conductors with specific conductivity (electrical resistance) in the plane direction has increased, and the required characteristics have also increased. Metal materials are often required to have various properties in addition to their original conductivity, and metal materials often have disadvantages. For example, certain resistance elements, sheet heating elements, conductive substrates for electrostatic recording and electrophotography, etc.
They require a surface electrical resistance of 0.9 Ω/hole, and use conductors other than bulk metal materials. These conductors are (1) generally coated with a conductive organic polymer on an insulating substrate, and (2) methods such as vapor deposition, sputtering, ion plating, etc. of metal materials or conductive metal compounds on an insulating substrate. (3) conductive powder dispersed in an organic polymer binder, etc. However, these methods each have their own drawbacks as described below, and the reality is that they do not fully meet the demands. For example, in (1), the organic polymer is a polymer electrolyte such as quaternary ammonium or sodium sulfonate, and in short, it develops conductivity through moisture absorption, so the drawback is that the conductivity changes significantly with changes in humidity. It cannot be used stably. In the case of (2), since the conductive layer is not inherently tough and is a thin film with a thickness of at most 1 μm, it has drawbacks such as lack of wear resistance and poor durability, and it cannot be used in a shape that is exposed on the surface. I can not use it. (3
) requires a large amount of conductive powder when aiming for relatively low resistance, so it lacks toughness and flexibility; when aiming for relatively high resistance, extremely high-precision fine adjustment is required for the dispersion of the conductive powder. However, it is difficult to obtain a material with uniform resistance.

In this way, for example, in a region that requires a surface resistance of 10 to 109 Ω/hole, the resistance value is stable under environmental conditions, over time, and mechanically, and the surface shape has little variation in resistance value. The current state of conductors is still being developed, and therefore devices and methods of use must be devised to put them into practical use.

The purpose of the present invention is to overcome the drawbacks of conventionally known planar conductors, and to provide a planar conductor that has little variation in resistance value and is stable under environmental conditions, over time, and mechanically. There is a particular thing.

The object of the present invention is to provide a surface conductive material (A) consisting essentially of metals and/or semiconductors with an average particle diameter of 10 μm or less and a volume resistivity of 10 −6 to 10 8 Ω.
・0.05 to 1 cm of conductive powder in an insulating organic polymer
This is achieved by a laminate structure having a layer (B) added with 5 wt%.

In the present invention, if the planar conductive material (A) has strength retention power, it can be used alone as a constituent component, but if it is a foil or thin film, etc., it may be necessary to Depending on the situation, insulating substrates such as paper, plastic sheets, plastic films, glass, ceramics, cloth, etc.
It can also be used by laminating it on top of C). In this case, lamination with the insulating substrate may be carried out using adhesives or pressure-sensitive adhesives, or by methods such as plating, vacuum deposition, chemical vapor deposition, sputtering, ion blating, etc. on the surface of the insulating substrate without using adhesives or adhesives. It may be formed into a thin film. The material of the planar conductive substance (A) is selected from metals (including alloys) and semiconductors. For example, Al, Cu, Sn, Zn
, Pd, Ag, Au, Pt, Rh.

Fe, Co, Cr, Ni, stainless steel, brass, permalloy, and many other metals and alloys, Si, C, In
2O3, SnO2, CdO, CdS, In2O3-Sn
There are semiconductors such as 02, and these may be used alone, or two or more types may be stacked or mixed. The surface resistance of these planar conductive materials is 1
It is preferable that the resistance is 0.09 Ω/mouth or less. Surface resistance is 109Ω
If the resistivity exceeds 1/2, it will be difficult to obtain a structure having a surface resistance of 10 to 10<9 >Ω/0, which is the object of the present invention, and this is not preferred.

The average thickness of the planar conductive material (A) in the present invention is:
A range of 5 Å to 5 mm is preferred. If the average film thickness does not reach this J building wall, it will be difficult to obtain a surface resistance of 109Ω/hole or less.
On the other hand, if it exceeds 5 mm, it may be difficult to put it to practical use as a planar conductor, which is not preferable. Further, the shape is preferably planar or cylindrical from the viewpoint of practical use and manufacturing. Note that when the above average film thickness is 100 Å or less, it is not necessarily a continuous film and often exhibits an island-like structure, but the above thicknesses are based on the assumption that the film has a uniform thickness throughout. It is expressed as follows. The above-mentioned planar conductive materials (including ultrathin films exhibiting such island-like structures)
When the film thickness of A) is 10 μm or less, it is desirable from the viewpoint of strength that it be laminated on the insulating substrate (C) or a thicker conductive material. In particular, a thin film of 5 Å to 1 μm of metal and/or semiconductor formed on an insulating substrate is preferably used for practical purposes.

In the present invention, the conductive powder, which is an essential component constituting the layer (B) attached to the surface of the planar conductive material (A), must have a volume resistivity of 10-6 to 108 Ω·cm,
It is preferable that the resistance is 10-4 to 105 Ω·cm. If the volume resistivity exceeds the above range, it may be difficult to obtain a surface electrical resistivity of 10 to 109 Ωcm, which is the objective of the present invention, and it may be necessary to add a large amount of conductive powder, which is not preferable. If the volume resistivity does not reach the above range, the resulting surface electrical resistance will be poorly homogeneous, which is not preferable. Conductive powders useful in the present invention include metal powders including alloys such as Al, Cu, Ag, and Ni-Cr, SnO2, In2O3, ZnO, and TiO.
There are many types of powder such as metal compound powders such as x (x = 1 to 2) and semiconductor powders represented by Si and C, and these can be used alone or in combinations or mixtures of two or more types. May be used in combination. These powders must have an average particle diameter of 10μ or less, and the major diameter must also be 10μ or less.
It is preferably less than μ, particularly preferably less than 5 μ. If the particle size exceeds the above range, the homogeneity of the surface electrical resistance of the obtained product deteriorates, which is not preferable.

In the present invention, the insulating organic polymer, which is the other essential component constituting the layer (B), may include various well-known thermoplastic resins, such as polyvinyl acetate, polyvinyl chloride, polyacrylic acid ester, and polymethacrylic acid. Thermoplastic resins such as esters, polyvinylidene chloride, polyvinyl acetals and their copolymers, polyesters, polyamides, polyurethanes, cellulose derivatives, silicone resins, polyethers, polyesteramides, polyesterethers, polyamideimides, ketone resins, alkyd resins, etc. ,
Composed of thermoplastic resins such as epoxy resins, polyurethanes, unsaturated polyesters, polyimides, polyamides, and polyacrylic ester copolymers and polymethacrylic ester copolymers containing hydroxyl, carboxyl, and amino groups, and curing agents. There are thermosetting resins such as
These may be used alone or in the form of a copolymer or blend of two or more types. Of course, it is not limited to the above. Further, additives such as adhesion promoters, plasticizers, stabilizers, antioxidants, ultraviolet absorbers, thickeners, and antifoaming agents may be added as necessary.

The thickness of the layer (B) is appropriately selected depending on the purpose, but
It is in the range of 1μ to 100μ, more preferably 2μ to 20μ.

The above (B) may be composed of two or more types of layers having different compositions or component ratios.

The ratio of the conductive powder constituting the layer (B) is 0.05 to 1
It is necessary that the content is 5 wt%, and particularly preferably,
It is preferably 0.1 to 10 wt%. If the proportion of the conductive powder does not reach the above range, the conductivity necessary for the purpose of the present invention will not be achieved, which is not preferable.On the other hand, if the proportion exceeds the above range, the above (
It is not preferable because it has problems such as insufficient flexibility and insufficient surface smoothness as described in 3).

In the present invention, as a method of laminating (B) on the surface of (A), a mixture of the conductive powder and the organic polymer is applied to the surface of (A) using a solvent or a dispersion medium as necessary. Commonly used methods include brush coating, dip coating, knife coating, roll coating, spray coating, flow coating, rotation coating (spinner, whaler, etc.), extrusion coating (including extrusion lamination), and fountain coating. It can be used as appropriate. Alternatively, the sheet or film of (B) above may be prepared in advance and laminated on the surface of (A) above.

In this way, it is possible to obtain a planar conductor with good resistance value stability and little variation, especially in the high resistance region, but the laminated conductor of the present invention cannot be predicted from the effects of each layer constituting it alone. It shows an action and effect that cannot be achieved. That is, the surface resistance value of the laminated conductor of the present invention is higher than the surface resistance value of the layer (A) alone, and lower than the surface resistance value of the layer (B) alone, and there is little variation in the resistance value. Therefore, the amount of conductive powder added to (B) can be significantly lower than when (B) is used alone (case (2) above), resulting in improved toughness and flexibility. This is advantageous and does not require sophisticated control measures for the dispersion of the conductive powder. In general, the surface resistance of a laminated structure is determined by the surface electrical resistance of the surface layer (for example, when an insulator is laminated on the surface layer of a conductor, the (surface) electrical resistance of the insulator is the governing factor). However, when a conductive powder is mixed into an insulating organic polymer, O. For example, when a sheet with a thickness of about 10μ is made by adding 5wt%, the surface electrical resistance is 101
Even if it is substantially an insulator in both the plane direction and the thickness direction with a resistance of 6 Ω/hole or more, when this is used as the component (B) of the present invention, the resulting laminate will have a resistance of 10 3 Ω/hole or less. Indicates surface resistance. In extreme terms, this means that conductivity is developed by laminating an insulator on the surface of a conductor, and this is the gist of the present invention. It is not clear to the inventors why such an effect occurs, and it must be said that this is a new finding that cannot be theoretically explained at present regarding the surface electrical resistance and the homogeneity of that resistance in a laminated structure. I don't get it.

The effect of the present invention is that the planar conductive material (A) is formed on an insulating substrate (
C) This is particularly effective when a thin film with a thickness of 500 Å or less is laminated thereon. That is, the thickness is less than 1 μm, especially 5 μm.
Thin films with a thickness of 00 Å or less have many problems as mentioned in (2) above, and in particular, they must be flexible for practical purposes, and in cases where the insulating substrate (C) is a plastic sheet, or when other materials are always used. The above-mentioned problems were a major obstacle when used in contact with other objects, but with the present invention, it has been achieved all at once to maintain conductivity, stabilize conductivity, and improve abrasion resistance and chemical resistance. That means it's done.

In short, the present invention can overcome the drawbacks of each of the above-mentioned (2) and (3) when it is made into a laminated structure, and also exhibits surface electrical resistance and homogeneity of surface electrical resistance that cannot be expected from both. This is a major feature that greatly contributes to expanding the practical range of planar conductive materials and improving the reliability and lifespan of components and devices using them.

The present invention will be explained below based on Examples. However, the present invention is not limited to this example.

In addition, in the example, the surface resistance value is 3 when the load is 500 g.
The surface resistance value measured using a 5 mm square electrode is expressed as the surface resistance value.

Examples 1 to 6 Al was vacuum deposited on one side of a 100 μm thick biaxially stretched polyethylene terephthalate film (“Lumirror” manufactured by Toshi) to obtain a planar conductive material with a surface resistance value of 5 Ω/hole.

Next, 0.05, 0.1, 0.5, 1.0% of SnO2-based conductive powder having an average particle size of 0.1 μm or less and a volume resistivity of 1Ω·cm was added to 100 parts by weight of the solid acrylic resin.
Add 0.10.20 parts of heavy ant, toluene and butyl acetate (
(weight ratio 1:1) as a solvent, the total solid content was 20% by weight, each was mixed in a ball mill for 16 hours (mixtures 1 to 6, respectively), and after drying was applied to the surface of the planar conductive material. Laminated conductor Examples 1 to 6 were obtained by coating with a reverse roll coater to a thickness of 5 μm. These surface resistance values were as shown in Table 1. From Table 1, Sn0
The amount of the 2-type conductive powder added is 0.05 to 15% by weight based on 100 parts by weight of the acrylic resin solid content, which is particularly effective for multilayer molding in terms of the center value and variation characteristics of the surface resistance value. It is clear that it is a conductor.

Comparative Examples 1 to 6 The above mixed solutions 1 to 6 were placed on a 100 μm thick “Lumirror”
6 was coated using a reverse roll coater so that the thickness after drying was 10 μm. These are summarized in Table 1 as Comparative Examples 1 to 6, respectively. All of these surface resistance values were greater than 2×10 9 Ω/mouth.

Example 7 In203-Sn was placed on a 100μ thick “lumirror”
O2 was vacuum-deposited to obtain a planar conductive material with a surface resistance value of 5×10 3 Ω/hole. Next, the mixture 2 of Example 1 was coated on the surface of the planar conductive material using a reverse roll coater so that the thickness after drying was 10 μm to obtain a laminated conductor example. The surface resistance value of this Example 7 is the first
It was as shown in the table.

From Table 1, it is clear that the laminated conductor of the present invention is excellent in terms of surface resistance value and variation characteristics.

Comparative Example 7 Only the above acrylic resin was coated with a reverse roll coater so that the thickness after drying was 5 μm on the planar conductive material with a surface resistance value of 5 Ω/mouth obtained in Example 1. Comparative example 7
I got it. This surface resistance value was greater than 2×10 9 Ω/mouth.

From the above results, in this example, the surface resistance value was 5
The surface resistance value is 2X10 on the planar conductive material of Ω/mouth.
By laminating so-called insulating resin layers that are larger than 9Ω/mouth, the surface resistance value can be increased from 6X106 to 7X104Ω.
This means that a laminated conductor with a diameter of 1/2 mm was obtained.

Claims (1)

[Claims] A conductive powder with an average particle size of 10μ or less and a volume resistivity of 10-6 to 10-8 Ωcm is placed in an insulating organic polymer on the surface of a planar conductive material consisting essentially of metals and/or semiconductors. A conductor with a layer containing 0.05 to 15% by weight.