JP2008174840A5 - Polymer parts - Google Patents

Description

The present invention relates to a polymer member having a metal film formed on a plastic polymer substrate.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a polymer member in which an electroless plating film having high adhesion strength is formed on a polymer substrate .

According to the first embodiment of the present invention, there is provided a method for producing a polymer member in which a plating film is formed on a polymer substrate, wherein the surface is impregnated with metal fine particles and particles of a substance dissolved in an electroless plating solution. A high-pressure carbon dioxide in a state in which the vicinity of the surface of the polymer substrate is swollen by bringing high-pressure carbon dioxide into contact with the polymer substrate, and the vicinity of the surface of the polymer substrate is swollen. There is provided a production method comprising contacting an electroless plating solution containing carbon dioxide with the polymer substrate to form a plating film on the polymer substrate.

On the other hand, in the method for producing a polymer member according to the first reference embodiment of the present invention, first, it is dissolved in metal fine particles such as Pd, Ni, Pt, Cu and the like, which are plating catalyst nuclei, and electroless plating solution inside the surface. The high-pressure carbon dioxide is brought into contact with the polymer substrate impregnated with the substance to be dissolved (eluting substance). At this time, when the polymer substrate is formed of an amorphous material, the glass transition temperature is lowered and the vicinity of the surface is softened and swells. On the other hand, when the polymer substrate is formed of a crystalline material, the intermolecular distance expands near the surface and swells even if it is not softened.

Next, an electroless plating solution containing high-pressure carbon dioxide is brought into contact with the polymer substrate in such a surface state. At this time, since the electroless plating solution is brought into contact with the vicinity of the surface of the polymer substrate swollen, the electroless plating solution can penetrate into the polymer substrate together with the high-pressure carbon dioxide. At this time, since the electroless plating solution mixed with high-pressure carbon dioxide in a supercritical state has a low surface tension, the electroless plating solution is more easily penetrated into the polymer substrate. As a result, the electroless plating solution reaches the metal fine particles existing inside the polymer substrate, and the plating film grows using the metal fine particles as catalyst nuclei. That is, in the method for producing a polymer member according to the first reference embodiment of the present invention, the plating film grows using not only the surface of the polymer substrate but also the metal fine particles present therein as catalyst nuclei. It is continuously formed from the surface to the inside (formed on the polymer substrate in a state in which a part of the plating film is bitten into the interior of the polymer substrate). Therefore, in the method for producing a polymer member according to the first reference embodiment of the present invention, it is not necessary to roughen the surface of the polymer substrate by etching unlike the conventional electroless plating method, and various types of polymer substrates are used. In contrast, a plating film having excellent adhesion can be easily formed. Further, since the surface of the polymer member is not roughened unlike the conventional electroless plating method, a plating film having a very small surface roughness (nano order) can be formed.

Further, in the method for producing a polymer member according to the first reference embodiment of the present invention, when the electroless plating solution containing high-pressure carbon dioxide is brought into contact with the polymer substrate, the high-pressure carbon dioxide has a diffusibility similar to gas. The electroless plating solution can be penetrated to a deeper position inside the polymer substrate, and a plating film can be continuously formed from a deeper position. For example, a plating film can be continuously formed from a depth on the order of microns (part of the plating film can be penetrated to a depth on the order of microns). Although the electroless plating method disclosed in Non-Patent Document 2 can also form a plating film continuously from the inside of the polymer substrate, the method of Non-Patent Document 2 uses the most of the polymer substrate. Since the surface layer portion is hydrophilic (wetting) by the photocatalytic effect and the plating film is grown on the surface-modified outermost layer, the penetration depth of the plating film is about several tens of nm. As in the present invention, it is difficult to manufacture a polymer member in which a part of the plating film penetrates at a depth of micron order.

Furthermore, in the method for producing a polymer member according to the first reference embodiment of the present invention, since the elution substance is impregnated inside the surface of the polymer substrate, an electroless plating solution containing high-pressure carbon dioxide is brought into contact with the polymer substrate. In this case, the elution substance impregnated inside the polymer substrate is eluted into the electroless plating solution, and the electroless plating solution enters the area occupied by the elution substance (the elution substance impregnation area is the electroless plating solution). Replaced by As a result, the plating film also grows in the region where the electroless plating solution has entered (the region occupied by the eluted material). In this method, even when a material such as a crystalline material whose internal free volume is difficult to expand is used as the polymer substrate, a sufficient region (e.g., an electroless plating film grows easily inside the polymer substrate ( Space) can be secured. In addition, since the size of the area occupied by the elution substance can be controlled by the molecular weight of the elution substance, fine plating particles that grow in the area occupied by the elution substance (area replaced by the electroless plating solution) The size of can be arbitrarily controlled by the molecular weight of the eluted substance. For this reason, when an electroless plating film is formed on a polymer substrate that is impregnated with metal particles together with an elution substance, a complicated shape (capillary shape, ant nest) is formed inside the polymer substrate. In other words, a plating film having a stronger adhesion can be formed as compared with the case where the elution substance is not permeated.

In the method of manufacturing a polymer member according to the first reference aspect of the present invention, it is possible to prepare a polymer base material impregnated with metal fine particles and particles of a substance dissolved in an electroless plating solution inside the surface. It is preferable to include forming a polymer substrate impregnated with metal fine particles and a substance that dissolves in the electroless plating solution inside the surface.

According to the second reference aspect of the present invention, there is provided a method for producing a polymer member in which a plating film is formed on a polymer substrate, comprising preparing a polymer substrate having metal fine particles and voids inside the surface. The high pressure carbon dioxide is brought into contact with the polymer substrate to swell the vicinity of the surface of the polymer substrate, and the electroless plating solution containing high pressure carbon dioxide is swollen in the vicinity of the surface of the polymer substrate. There is provided a manufacturing method comprising contacting the polymer substrate and forming a plating film on the polymer substrate.

In the method for producing a polymer member according to the second reference aspect of the present invention, as in the method for producing a polymer member according to the first reference aspect of the present invention, a part of the plating film is allowed to permeate the inside of the polymer substrate. it can. Therefore, it is not necessary to roughen the surface of the polymer substrate by etching unlike the conventional electroless plating method, and a plating film having excellent adhesion can be easily formed on various types of polymer substrates. be able to. Further, since the surface of the polymer member is not roughened unlike the conventional electroless plating method, a plating film having a very small surface roughness (nano order) can be formed.

Furthermore, in the manufacturing method of the second polymer member according to Reference Aspect of the present invention, since there are voids inside the surface of the polymer substrate, the electroless plating solution containing pressurized carbon dioxide when in contact with the polymer substrate The electroless plating solution enters the gap, and a plating film grows in the gap. Therefore, even when a material such as a crystalline material whose internal free volume is difficult to expand is used as a polymer substrate, an area (space) where an electroless plating film easily grows inside the polymer substrate Can be secured.

In the method for producing a polymer member according to the second reference aspect of the present invention, the preparation of a polymer base material having metal fine particles and voids inside the surface is performed using an injection molding machine equipped with a mold and a heating cylinder. Introducing high-pressure carbon dioxide in which a metal complex containing fine particles is dissolved into the molten resin of the polymer substrate in the heating cylinder; and introducing the molten resin into which the high-pressure carbon dioxide in which the metal complex is dissolved is introduced into the gold It is preferable to include injection into the mold and foaming high-pressure carbon dioxide in the injected molten resin to form a void.

In the polymer member manufacturing method, the electroless plating solution preferably contains alcohol.

Therefore, as a result of repeated studies to solve this problem, the present inventors have found that the electroless plating solution is mainly composed of water, but further, by mixing alcohol with the electroless plating solution, It has been found that even if the plating solution and high-pressure carbon dioxide are not stirred, the high-pressure carbon dioxide and the plating solution can be mixed stably and easily. This is considered to be because alcohol is easily compatible with high-pressure carbon dioxide. Therefore, usually, in formulating the electroless plating solution, the containing stock solution of such as metal ions and a reducing agent, for example, according to the component ratio recommended by the manufacturer, although Ken'yoku the plating solution diluted with water, the polymer In the member manufacturing method, a stable electroless plating solution in which the electroless plating solution and high-pressure carbon dioxide are uniformly mixed can be prepared by further mixing alcohol with water at an arbitrary ratio. The volume ratio of water to alcohol (alcohol / water) is arbitrary, but is preferably in the range of 10 to 80%. When there is little alcohol, it will become difficult to obtain a stable liquid mixture. Moreover, when there are too many alcohol components, since organic solvents, such as ethanol, are insoluble in nickel sulfate used for nickel-phosphorus plating, for example, the bath may not be stable.

In addition, the kind of alcohol which can be used for the manufacturing method of the said polymer member is arbitrary, Methanol, ethanol, n-propanol, isopropanol, butanol, heptanol, ethylene glycol, etc. can be used.

In the method for manufacturing the polymer member, when added to the alcohol in the electroless plating solution, alcohol is because the surface tension is less than water, the surface tension of the electroless plating solution the alcohol added is significantly reduced . For this reason, the electroless plating solution is more likely to penetrate into the free volume (inside), the voids, the elution substance impregnation region, and the like of the polymer substrate.

In the polymer member manufacturing method, the electroless plating solution preferably contains a surfactant. Thereby, the compatibility (affinity) of the high pressure carbon dioxide such as supercritical carbon dioxide and the electroless plating solution that is an aqueous solution can be further improved, and the formation of the emulsion can be promoted. Also, the affinity of the plating solution for the polymer substrate can be improved.

In the method for producing the polymer member, the high-pressure carbon dioxide is preferably carbon dioxide in a supercritical state having a pressure of 7.38 MPa to 20 MPa. The critical pressure of carbon dioxide is 7.38 MPa, but a supercritical state higher than that is preferable because the density becomes high and it is easy to be compatible with the plating solution. On the other hand, when the pressure is increased to 30 MPa or more, problems such as excessive use of carbon dioxide and difficulty in sealing a high-pressure vessel are undesirable.

In the method for producing a polymer member, it is preferable that a minimum thin plating film is formed on the surface of the polymer substrate in a short time to ensure adhesion between the plating film and the polymer substrate. Thereby, it is possible to suppress the electroless plating solution from penetrating excessively into the polymer base material, and it is possible to suppress deformation and alteration of the polymer base material due to the electroless plating solution. When it is necessary to increase the film thickness of the plated film, after forming an electroless plating film by the upper Symbol method on a polymer substrate, the conventional plating method under normal pressure (electroless plating method and / or By performing the electrolytic plating method, a plating film having a desired film thickness can be laminated on the polymer substrate. According to this method, a plating film having both the reliability (adhesiveness) of the plating film and securing of physical properties such as conductivity can be obtained.

Further, according to the study of the present inventor, in the method of plating by adding high-pressure carbon dioxide as described in Patent Document 2 and Non-Patent Document 1 to the plating solution, when high-pressure carbon dioxide is mixed, It has been found that problems such as a decrease in the deposition rate of electroless plating occur depending on the mixing conditions. This is because the acidic high-pressure carbon dioxide is mixed with the electroless plating solution at a high density, so that the pH of the electroless plating solution is lowered, and the plating bath mixed with the high-pressure carbon dioxide is lower than the lower limit of the optimum pH range. It is thought that it is to become. Therefore, in the manufacturing method of the polymer member may be previously adjusted in advance increases the pH of the electroless plating solution. In this case, when an electroless plating solution containing high-density carbon dioxide is prepared, the pH of the electroless plating solution is lowered by mixing high-density carbon dioxide, and the plating bath can be brought to an optimum pH range. . Therefore, when this method is used, problems such as a decrease in the deposition rate of the plating film described above can be suppressed.

In the method for producing the polymer member, Ni, Co, Pd, Cu, Ag, Au, Pt, Sn, etc. can be used as the metal to be the plating film, and these are nickel sulfate, chloride in the electroless plating solution. Supplied from metal salts such as palladium and copper sulfate. As the reducing agent, dimethylamine borane, sodium hypophosphite (sodium phosphinate), hydrazine, formalin, sodium borohydride, potassium borohydride, titanium trichloride, or the like can be used.

The material for forming the polymer substrate that can be used in the production method is arbitrary, and a thermoplastic resin, a thermosetting resin, and an ultraviolet curable resin can be used. In particular, it is desirable to use a polymer substrate formed of a thermoplastic resin. The type of thermoplastic resin is arbitrary, and can be applied to either amorphous or crystalline. For example, synthetic fibers such as polyester, polypropylene, polyamide resin, polymethyl methacrylate, polycarbonate, amorphous polyolefin, polyetherimide, polyethylene terephthalate, liquid crystal polymer, ABS resin, polyamideimide, polyphthalamide, polyphenylene sulfide, polylactic acid Biodegradable plastics such as nylon resin, nylon resin and the like and composite materials thereof can be used. Further, a resin material in which various inorganic fillers such as glass fiber, carbon fiber, nanocarbon, and mineral are kneaded can also be used.

Moreover, in the manufacturing method of the said polymer member, the form of a polymer base material and a preparation method are arbitrary, For example, the sheet | seat and pipe produced by extrusion molding, the polymer molded article produced by ultraviolet curing and injection molding are used. Can do. In consideration of industrial properties, it is preferable to use a polymer molded product obtained by injection molding with high continuous productivity.

According to the above polymer member manufacturing method, the electroless plating solution penetrates into the inside of the polymer base material to cause a plating reaction, so that it is not necessary to roughen the surface of the polymer base material as in the prior art. A plating film having excellent adhesion to the polymer substrate can be formed.

According to the manufacturing method of the polymer member, the area occupied by the eluted material impregnated therein the polymer substrate, or, since infiltrated an electroless plating solution in the gap can be grown plating film, crystalline Even in the case where a material whose internal free volume is difficult to expand is used as a polymer substrate, such as a conductive material, it is possible to easily secure a region (space) in which the electroless plating film grows inside the polymer substrate. it can.

Furthermore, according to the above method for producing a polymer member, a plating film grows in an area occupied by the eluted substance impregnated inside the polymer base material or in a void, so that the plating film area of a complicated shape is formed inside the polymer base material. And a plating film having stronger adhesion can be formed.

According to the study by the present inventors, the electroless plating solution 8 is mainly composed of water, but it is understood that the high pressure carbon dioxide and the electroless plating solution are easily mixed stably by mixing alcohol. It was. This is considered due to the fact that alcohol and supercritical carbon dioxide are easily compatible. Therefore, when alcohol is mixed with the electroless plating solution as in this embodiment, it is not necessary to add a surfactant to the electroless plating solution or to stir the electroless plating solution. Furthermore, in order to cause the plating solution to penetrate into the polymer base material together with the high-pressure carbon dioxide to cause the plating reaction inside the polymer base material, the surface tension is lower than the water alone when the alcohol is added to the plating solution. Therefore, it is more preferable. However, in the method for producing a polymer member of the present invention , in order to further improve the compatibility (affinity) between the high pressure carbon dioxide and the electroless plating solution, a surfactant is added, or the electroless plating solution is stirred. You may do it. In this example, as described later, a surfactant was added to the electroless plating solution, and the electroless plating solution was also stirred.

In the electroless plating treatment of Example 6 above, first, only the high pressure carbon dioxide was brought into contact with the polymer substrate to swell the surface of the polymer substrate, and then the electroless plating solution was brought into contact with the polymer substrate. The method for producing the polymer member of the present invention is not limited to this. For example, a first electroless plating solution containing a high-pressure carbon dioxide in a polymer substrate and having a plating solution concentration that does not cause a plating reaction is contacted with the polymer substrate, and then plating containing a high-pressure carbon dioxide and causing a plating reaction A plating film may be formed by bringing a second electroless plating solution having a solution concentration into contact with the polymer substrate. Here, the plating solution concentration refers to the concentration of a reducing agent such as sodium hypophosphite that is a factor that determines the plating reaction in the plating solution. That is, the above method will be described more specifically. An electroless plating solution (first electroless plating solution) and a high-pressure carbon dioxide, which have a sufficiently small amount of reducing agent so as not to cause a plating reaction, are brought into contact with a polymer substrate. Then, the plating solution is infiltrated into the polymer substrate, and then the first electroless plating solution is replaced with an electroless plating solution (a second electroless plating solution containing a reducing agent enough to cause a plating reaction). ) May be substituted. Alternatively, a second electroless plating solution is formed by adding a solvent containing water or alcohol containing a reducing agent as a main component and high-pressure carbon dioxide to the first electroless plating solution having a small reducing agent. May be.

Further, in Example 6, during the injection molding of the polymer base material, an example in which a metal complex is introduced into the flow front portion of the molten resin to perform injection molding, and the metal fine particles penetrate into the surface of the polymer base material has been described. The manufacturing method of the polymer member of this invention is not limited to this. You may shape | mold the polymer base material which the metal microparticles impregnated to the surface inside by the sandwich molding method. Specifically, a molten resin containing metal fine particles may be injected from a heating cylinder, and then a molten resin not containing metal fine particles may be injected from another heating cylinder to be molded. In addition, as in Example 1, after forming a polymer base material that is not impregnated with metal fine particles on the surface, high-pressure carbon dioxide in which a metal complex is dissolved is brought into contact with the polymer base material so that the metal fine particles are formed on the polymer base material. It may penetrate into the surface.

In the present embodiment, in order to form a growth area of sufficient plating film in the interior of the polymer substrate has been described an example using polyethylene glycol as the water-soluble substance, method for producing a polymer member of the present invention Without being limited thereto, mineral components such as magnesium oxide and calcium carbonate, starch, sodium alginate, polyvinyl alcohol, polyvinyl methyl ether, acrylic acid and the like may be used. In addition, soluble low molecular weight materials such as polyethylene oxide, ε-caprolactam, alcohol (ethanol, propanol, butanol, etc.), ethylene glycol, polyacrylamide, polyvinyl pyrrolidone, ethyl cellulose, acetyl cellulose, etc. are used instead of water-soluble substances. Also good.