JP2005263943A - Conductor composition and conductive article - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a conductor composition used for forming, in a substrate made of resins, a conductor section which has good adhesiveness, flexibility and plasticity and in which reduction of conductivity due to bending or creasing is suppressed, and to provide a conductive article. <P>SOLUTION: The conductor composition used for forming a conductor section in a substrate made of resins comprises a conductive material powder, the same type of resin as the resin composing the substrate made of resins and/or a cellulose-based resin, and a solvent. The conductive material powder is gold; the resin is a polyamide-based resin; and the cellulose-based resin is ethyl cellulose. The conductive article is obtained by arranging the conductor section resulting from the conductor composition in all or part of the region of the substrate made of resins. The substrate made of resins has the shape of a tube or a film. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a conductor composition, and more specifically, to form a conductor portion having good adhesion and flexibility and flexibility on a resin substrate such as a resin tube or a resin film. The present invention relates to a conductive composition used and a conductive article using the same.

2. Description of the Related Art Conventionally, formation of a conductive portion such as an electric lead on a resin substrate has been actively performed in the electronic industry and the like as represented by a printed wiring board.
In recent years, a conductive coating is applied to the outer periphery of a flexible resin tube as an internal insertion tool such as a catheter or medical tube, and this is removed by laser processing to form an electrical lead of a predetermined shape. Have been proposed (see, for example, Patent Document 1).
JP-A-8-131545

  However, in such a conventional technique, in various electronic boards such as a printed wiring board, the board itself usually cannot be required to have flexibility, and therefore, both flexibility and adhesion to the board are provided. No consideration has been given to a conductive film that can maintain conductivity without being peeled off by bending or bending the substrate.

On the other hand, in the in-vivo insertion portion as described above, a conductive film is coated by various vapor deposition methods, so that a large-scale device such as a vacuum vapor deposition device is required, and the vapor deposition operation is complicated.
Furthermore, the conductive film formed by vapor deposition and the electric lead formed therefrom are inferior in flexibility and flexibility, and therefore cannot follow the change of the resin tube having flexibility, and can be bent or bent from the outer peripheral surface of the resin tube. There was a problem that peeling or a decrease in conductivity could not be avoided.

  The present invention has been made in view of such problems of the prior art, and the object of the present invention is to have good adhesion, flexibility and flexibility, and conductivity by bending or bending. An object of the present invention is to provide a conductor composition used for forming a conductor portion in which deterioration in property is suppressed on a resin base material, and a conductive article using the same.

  As a result of intensive studies to solve the above problems, the present inventors have found that the above problems can be solved by using the same kind of resin as the resin constituting the substrate, and the present invention is completed. It came to.

  That is, the conductor composition of the present invention is a conductor composition used for forming a conductor portion on a resin base material, and is composed of a conductive material powder, the same type of resin as the constituent resin of the resin base material, and It is characterized by comprising a cellulose resin and / or a solvent.

  In a preferred embodiment of the conductor composition of the present invention, the conductive material powder is a powder of at least one material selected from the group consisting of gold, silver, copper and carbon, and the resin is a polyamide resin. The cellulosic resin is ethyl cellulose.

  Furthermore, in another preferred embodiment of the conductor composition of the present invention, the conductive material powder is gold, the resin is a polyamide resin, and the polyamide resin is 2 to 12 parts by weight with respect to 100 parts by weight of gold. It is characterized by comprising 0.5 to 2 parts by weight of ethyl cellulose.

On the other hand, the conductive article of the present invention is characterized in that the conductor portion resulting from the conductor composition as described above is disposed in the whole or a part of the resin base material.
Moreover, the suitable form of the electroconductive article of this invention is characterized by the shape of the said resin-made base materials being a tube form or a film form.

Furthermore, in another preferred embodiment of the conductive article of the present invention, the resin base material has a tubular shape, and the conductor portions are arranged at predetermined intervals in the circumferential direction of the tubular resin base material, It extends in the longitudinal direction.
Furthermore, in another preferred embodiment of the conductive article of the present invention, the conductive substrate is in the form of a film, and the conductor portion is formed in a desired pattern on the surface of the film-shaped conductive substrate by a screen printing method. It is formed.

  According to the present invention, since the same kind of resin as that constituting the base material is used, the adhesiveness is good, the flexibility and flexibility are provided, and the decrease in conductivity due to bending, bending, etc. is suppressed. In addition, a conductive composition used for forming a conductive portion on a resin base material, and a conductive article using the conductive composition can be provided.

Hereinafter, the conductor composition of the present invention will be described in detail. In the present specification, “%” represents a mass percentage unless otherwise specified.
As described above, the conductor composition of the present invention is used to form a conductor portion (typically a conductive film) on a resin substrate, and typically forms a paste. Moreover, it contains a conductive material powder, the same kind of resin as the constituent resin of the resin base material, a cellulose resin, or a mixture of both resins, and a solvent.

Here, the conductive material powder is not particularly limited as long as it is a powder of a conductive material. Noble metals such as gold (Au), silver (Ag), copper (Cu), and other metals And powders such as carbon can be exemplified, and these can be used alone or in any combination of two or more.
As such a conductive material powder, a powder having excellent oxidation resistance, hardly causing migration, and having a low resistance value (high electric conductivity) is preferable. From this viewpoint, Au and / or Ag powder is preferable. Can be used. Furthermore, from the viewpoint of use for catheters, medical tubes, and the like, Au powder is optimal in consideration of biological safety.
The particle diameter of the conductive material powder can be appropriately selected depending on the size and use of the resin base material, but is typically 0.05 to 2.0 μm by SEM (scanning electron microscope) observation. is there.

Also, among the resin components of this conductor composition, “same type” in the same type of resin as the constituent resin of the resin base material (hereinafter referred to as “base type resin”) means that the resin component is completely identical. For example, a polyamide resin should be selected for the base resin and a polyethylene base resin should be selected for the polyethylene resin (base material). This means that some modification is not required.
In the present invention, by employing such a base resin as a resin component, after the conductor composition is dried, the adhesive state between the conductive material powder and the resin base material can be kept in a good state. .

  As a typical resin combination example in the present invention, a combination of a polyamide-based resin base material and a polyamide-based resin base material resin can be given. The following formula (1)

(Wherein PA represents a polyamide residue, PE represents a polyether residue, and n represents a natural number).
In addition, this polyamide elastomer can be obtained as Pebax (ATOCHOM, Toray Industries, Inc .; registered trademark name).

  On the other hand, the cellulose resin in the resin component is not particularly limited, and examples thereof include ethyl cellulose, methyl cellulose, benzyl cellulose, trityl cellulose, cyanethyl cellulose, carboxymethyl cellulose, aminoethyl cellulose, and oxyethyl cellulose. In relation to the elastomer, it is desirable to mix ethyl cellulose. By adding this additive resin, the stability of the conductor composition paste can be improved, and the flexibility and flexibility of the resulting conductor film can be improved. The surface smoothness can also be improved.

  Moreover, as a solvent to be used, there is no adverse effect on the dispersibility of the above-mentioned conductive material powder, and it has the ability to slightly dissolve the base resin and / or the cellulose resin, and 70 ° C. in consideration of the use mode. Although it can be evaporated to a certain degree, typically, when Au, polyamide elastomer and ethyl cellulose are selected, 1-butanol (n-butyl alcohol) can be preferably used.

The blending ratio of the above components in the conductor composition of the present invention can be appropriately changed according to the type of the component used, the type of the resin base material, the type of the target conductive article (described later), and the like. Although it is not unambiguous, in the case where Au is selected as the conductive material powder, polyamide elastomer is selected as the base resin, ethyl cellulose is selected as the cellulose resin, and butanol is selected as the solvent, 2-12 wt. Parts, preferably 4 to 8 parts by weight, 0.5 to 2 parts by weight of ethyl cellulose, and 20 to 100 parts by weight of butanol.
The greater the amount of polyamide elastomer blended, the better the adhesion of the resulting conductive coating to the resin substrate, but the greater the electrical resistance. Therefore, the blending amount in the above range is usually appropriate.
In addition, as the amount of ethyl cellulose is increased, the stability of the paste, the flexibility of the conductive film and the surface smoothness can be improved, but the electrical resistance value is increased. The amount is appropriate.
Furthermore, the amount of butanol blended takes into account the application method of the conductor composition of the present invention, that is, the viscosity with good work efficiency according to the coating method and coating method, and the film thickness required for the specific application. Although it can be changed, the above range is usually appropriate.

Formation of the conductor part and the conductive film using the conductor composition of the present invention is typically performed by covering the necessary part of the resin base material with a paste-like conductor composition and drying at about 70 to 120 ° C. It can be done simply by curing.
Therefore, a conductor part and a conductive film can be formed easily and in a short time as compared with the conventional vapor deposition method.
In addition, as a coating method, conventionally well-known various methods can be employ | adopted, for example, the immersion method, the apply | coating method, the printing method, the transfer method, the dispensing method, the dotting method etc. can be performed. In addition, laser trimming, etching, sand blasting, cutting, and other methods can be employed as a method for processing the conductor portion into a desired shape.

The conductor part and conductive film formed by the conductor composition of the present invention as described above are excellent in adhesiveness, flexibility and flexibility to the resin base material, and can be used for shape deformation of the resin base material. It can be deformed following it, and even after such deformation is repeated, its conductivity hardly decreases.
For example, a conductor part formed on a resin tube or a resin film does not peel off from the tube surface or film surface even after the tube or film is folded in approximately two parts, and the conductivity is reduced. There is no.
Further, for example, if the deformation is curved by about 90 ° with respect to the tube axis direction or the film surface direction, peeling and conductivity reduction will not occur even if it is repeated about 100 times.

Next, the conductive article of the present invention will be described.
The conductive article of the present invention is the one in which the above-described conductor composition of the present invention is disposed so as to cover all or a part of the resin base material. In addition, it is required that it is a resin base material containing the same kind of resin as the base resin contained in the conductor composition.
In this case, the shape of the resin substrate is not particularly limited, but examples of suitable shapes include a tube shape and a film shape.

When the conductor part is formed on the tube-shaped resin base material, the above-mentioned catheter and medical tube can be used as the application. In this case, the outer shape of the tube is about 0.5 to 3 mm, and the inner diameter is about 0.3 mm. It is about 3 to 2 mm.
In addition, as the shape of the conductor, it is possible to adopt a shape (so-called strip shape) that is arranged at a predetermined interval in the circumferential direction of the tube and extends in the longitudinal direction (axial direction) of the tube, Such a conductor can function as electrical wiring in a catheter or endoscope having a resin tube.

The strip-shaped conductor portion is formed by applying the conductor composition of the present invention to the outer peripheral surface of a resin tube and drying and curing it to form a conductive film, and then excimer laser or other laser light is made of resin. It can be formed by repeatedly scanning in the longitudinal direction of the tube and partially removing the conductive coating.
At this time, thermal shock, expansion and contraction, and the like act on the conductive coating, but the conductive coating according to the present invention is extremely excellent in adhesion and flexibility to the resin base as described above. The adverse effects can be remarkably reduced by the laser processing as described above.
On the other hand, when the resin substrate is in the form of a film, the conductor portion can be easily formed by a known method such as a screen printing method.

  Hereinafter, the present invention will be described in more detail with reference to some examples and comparative examples, but the present invention is not limited to these examples.

(Examples 1-18, Comparative Example 1)
A spherical Au powder having a SEM particle size of 0.1 to 0.3 μm obtained by a wet reduction method and a vehicle in which a predetermined resin is heated, stirred and dissolved in butanol are prepared in a predetermined blending amount and stirred with a stirrer. And uniformly dispersed to obtain a conductor paste of each example. Table 1 shows the types of resin and the composition of Au powder and resin. In addition, the compounding quantity in Table 1 is shown by the weight part. The amount of butanol was adjusted so that the amount of Au powder in the paste was about 50 to 60%.

[Performance evaluation]
A tube made of modified polyamide resin having an outer diameter of 0.8 mm and a length of 10 cm is immersed in the paste of each example, and the paste of each example is dip coated on the outer periphery of this tube, and then dried at 120 ° C. for 1 hour. The conductive tube (sample) of each example was used.
The modified polyamide constituting the resin tube is the same as that used in Example 1 or the like.
(Resistivity)
The resistance value between the both ends of the conductive tube of each said example was measured, and the specific resistance was computed from the weight and length of the coating film by a conductor paste. The obtained results are also shown in Table 1.
Further, after bending the central portion of the conductive tube after measuring the resistance value by about 90 ° with respect to the axial direction, the resistance value was measured again to examine the change in the specific resistance. It can be said that the smaller this change, the better the flexibility and flexibility. The obtained results are also shown in Table 1.
(Adhesion strength)
The central portion of the conductive tube of each example was bent about 180 ° with respect to the axial direction, and the adhesion strength of the coating film was visually observed. If it is difficult to generate cracks in this performance evaluation, it can be said that the flexibility of the coating film is good and the workability of the conductive tube itself is also good. The obtained results are also shown in Table 1.
In addition, the meaning of the symbol in Table 1 is as follows.
○: No cracks Δ: Small cracks are generated when bent, but no marks are visible after restoration ×: Cracks remain or peeling occurs even after restoration (surface smoothness)
About the conductive tube of each example, the coating film surface after the said bending was observed with the microscope, and surface smoothness was evaluated from states, such as an unevenness | corrugation and glossiness. The obtained results are also shown in Table 1.
The meanings of symbols in Table 1 are as follows.
○: Glossy, no irregularity △: Glossy, but irregularity ×: No glossiness

From the results of Table 1, the basic adhesion strength is ensured by the blending of the modified polyamide and no peeling or the like occurs, but the resistance value change and the surface smoothness after bending become slightly insufficient (Examples 1 to 4). . On the other hand, when ethyl cellulose is mix | blended, it turns out that the resistance value change and surface smoothness after bending are improved (Examples 9-18).
Moreover, it turns out that adhesion | attachment intensity | strength tends to become inadequate only by mixing | blending ethylcellulose (Examples 5-8).

Claims (10)

  A conductive composition used for forming a conductor part on a resin base material, comprising a conductive material powder, a resin of the same type as the constituent resin of the resin base material and / or a cellulose resin, and a solvent. A conductor composition comprising the conductor composition.   2. The conductor composition according to claim 1, wherein the conductive material powder is a powder of at least one material selected from the group consisting of gold, silver, copper and carbon.   The conductor composition according to claim 1, wherein the resin is a polyamide-based resin.   The conductor composition according to any one of claims 1 to 3, wherein the cellulose resin is ethyl cellulose.   The conductive material powder is gold, the resin is a polyamide resin, and 2 to 12 parts by weight of a polyamide resin is blended with 100 parts by weight of gold. The conductor composition as described in one term.   6. The conductor composition according to claim 5, wherein the cellulosic resin is ethyl cellulose and is blended with 0.5 to 2 parts by weight of ethyl cellulose.   A conductive article comprising a conductor portion resulting from the conductor composition according to any one of claims 1 to 6 arranged in the whole or a part of a resin base material.   The conductive article according to claim 7, wherein the resin base material has a tube shape or a film shape.   The resin base material has a tubular shape, and the conductor portions are arranged at predetermined intervals in the circumferential direction of the tubular resin base material and extend in the longitudinal direction thereof. Item 9. A conductive article according to Item 8.   The conductive material according to claim 8, wherein the conductive substrate is formed in a film shape, and the conductor portion is formed in a desired pattern on the surface of the film-shaped conductive substrate by a screen printing method. Goods.