JP4092360B1 - Polymer member and manufacturing method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polymer member in which an electroless plating film having high adhesion strength is formed on a polymer substrate.
A polymer base material in which a first region from a surface to a predetermined depth is impregnated with metal fine particles, and a metal film formed on the surface of the polymer base material, and the predetermined surface from the surface of the polymer base material is provided. A polymer member is provided in which a part of the metal film penetrates into a second region having a depth shallower than the depth. Polymer substrate Since a part of the formed metal film penetrates into the polymer substrate, it is possible to provide a polymer member on which an electroless plating film having higher adhesion strength is formed.
[Selection] FIG.

Description

  The present invention relates to a polymer member in which a metal film is formed on a plastic polymer substrate and a method for producing the same.

  Conventionally, an electroless plating method is known as a method for forming a metal film on the surface of a polymer substrate (polymer molded product) at low cost. However, in the electroless plating method, in order to ensure the adhesion of the plating film, the surface of the polymer substrate is treated with an oxidant having a large environmental load such as hexavalent chromic acid or permanganic acid as a pretreatment for the electroless plating. Etching is required to roughen the surface of the polymer substrate. In addition, polymers immersed in such an etching solution, that is, polymers to which electroless plating can be applied are limited to polymers such as ABS. This is because ABS contains a butadiene rubber component, which is selectively immersed in an etching solution to form irregularities on the surface, whereas other polymers are selective for such an etching solution. This is because there are few components that are oxidized to the surface and it is difficult to form irregularities on the surface. Therefore, for a polycarbonate or the like which is a polymer other than ABS, a plating grade in which ABS or an elastomer is mixed to enable electroless plating is commercially available. However, with such plating grade polymers, deterioration of physical properties such as a decrease in heat resistance of the main material is inevitable, and it has been difficult to apply to molded products that require heat resistance.

  Conventionally, a technique for applying a surface modification method using high-pressure carbon dioxide such as supercritical carbon dioxide to plating pretreatment has been proposed. In the surface modification method using high-pressure carbon dioxide, the functional material is dissolved in the high-pressure carbon dioxide, and the high-pressure carbon dioxide in which the functional material is dissolved is brought into contact with the polymer base material. The polymer substrate surface is made highly functional (modified) by infiltrating the inside of the surface. For example, the present inventors have disclosed a method of performing a surface modification treatment using high-pressure carbon dioxide at the same time as injection molding to make the surface of a polymer molded product highly functional (for example, see Patent Document 1).

  Patent Document 1 discloses the following surface modification method. First, after plasticizing and weighing the resin in a heating (plasticizing) cylinder of an injection molding machine, the screw in the heating cylinder is sucked back and moved backward. Next, a functional organic material such as high pressure carbon dioxide in a supercritical state and a metal complex dissolved therein is applied to the front part (flow front part) of the molten resin that has become negative pressure (reduced pressure) due to the suck back of the screw. Introduce. By this operation, the high pressure carbon dioxide and the functional material can be infiltrated into the molten resin in the front portion of the screw. Next, the molten resin is injection-filled into a mold. At this time, the molten resin in the front portion of the screw infiltrated with the functional material is first injected into the mold, and then the molten resin in which the functional material is hardly infiltrated is injected and filled. When the molten resin in the front part of the screw infiltrated with the functional material is injected, the molten resin in the front part of the screw is pulled by the mold surface due to the fountain flow phenomenon (fountain effect) of the flowing resin in the mold. A surface layer (skin layer) is formed in contact with the mold. Therefore, in the surface modification method described in Patent Document 1, a polymer molded article in which a functional material is impregnated (surface-modified by the functional material) is produced inside the surface of the polymer molded article. When a metal complex containing metal fine particles as a plating catalyst is used as a functional material, a polymer molded product impregnated with the plating catalyst on the surface can be obtained, so that the surface is roughened with an etching solution as in the conventional plating pretreatment method. An injection-molded article that can be electrolessly plated can be obtained without the need to make it.

  Furthermore, conventionally, a method of performing electroless plating using an electroless plating solution containing supercritical carbon dioxide has been disclosed (for example, Patent Document 2 and Non-Patent Document 1). In these documents, an electroless plating solution and supercritical carbon dioxide are dissolved using a surfactant, and an emulsion (emulsion state) is formed by stirring to cause a plating reaction in the emulsion. A method is disclosed. Usually, in electroplating or electroless plating, hydrogen gas generated during the plating reaction stays on the surface of the object to be plated, causing pinholes in the plating film. However, when an electroless plating solution containing supercritical carbon dioxide is used as in the electroless plating method disclosed in the above-mentioned document, supercritical carbon dioxide dissolves hydrogen, so it is generated during the plating reaction. It is said that the hydrogen that is removed is removed, so that a pinhole is hardly generated and an electroless plating film having high hardness is obtained.

  In addition to the electroless plating method using supercritical carbon dioxide, an electroless plating method for an insulating material by a build-up method using a photocatalyst has been conventionally proposed (for example, see Non-Patent Document 2). In the technique proposed in Non-Patent Document 2, a plating film in which a copper plating film enters a modified layer (thickness of about 30 to 50 nm) formed on the surface of an epoxy resin insulating material is formed. Yes.

Japanese Patent No. 3696878 Japanese Patent No. 3571627 Surface technology Vol. 56, no. 2, page 83 (2005) Surface technology Vol. 57, no. 2, pp. 49-53 (2006)

  As described above, in the conventional polymer plating method, it is necessary to perform a pretreatment with a large environmental load, and the selectivity of the polymer material is narrow.

  In addition, when a plating film is formed on a polymer member obtained using the technique described in Patent Document 1, the surface of the polymer member is not roughened, so that it is difficult to obtain a physical anchor effect of the plating film. There was a problem that it was difficult to obtain strong adhesion of the molded product.

  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. Another object of the present invention is to provide a method for producing a polymer member that forms an electroless plating film having low adhesion and high adhesion strength on the surface of a polymer substrate.

According to the slave intends process to a first aspect of the present invention to be described later, a polymer member, the polymer substrate metal fine particles are impregnated in a first region to a predetermined depth from the surface, the above said polymer substrate A part of the metal film penetrates into a second region having a depth shallower than the predetermined depth from the surface of the polymer base material. polymer member is obtained, et al.

The “predetermined depth” impregnated with the metal fine particles in the polymer member means a depth of 1 μm or more. In addition, the “depth shallower than the predetermined depth” in which a part of the metal film penetrates is a depth of 100 nm or more from the surface of the polymer substrate and a position shallower than the predetermined depth impregnated with the metal fine particles. (Hereinafter, this depth is also referred to as the penetration depth of the metal film).

As described above, in the polymer member produced by the electroless plating method disclosed in Patent Document 2 and Non-Patent Document 1, as described later, metal fine particles existing on the outermost surface of the polymer substrate are used as catalyst nuclei. Since the metal film grows, the metal film hardly grows inside the polymer substrate (a part of the metal film hardly penetrates the polymer substrate). Moreover, in the polymer member produced by the electroless plating method disclosed in Non-Patent Document 2, the penetration depth of the metal film is about 30 to 80 nm. On the other hand, in the above polymer member , compared to Patent Document 2, Non-Patent Document 1, and Non-Patent Document 2, a part of the metal film continuously grows from the surface of the polymer substrate to a deeper position. That is, since a part of the metal film penetrates into a deeper position inside the polymer substrate, a larger anchor effect is obtained, and a polymer substrate provided with a metal film having higher adhesion strength is obtained. Note that the penetration depth and concentration distribution of the metal fine particles vary depending on the material of the polymer substrate, process conditions, and the like.

In the polymer member , particles of a substance that dissolves in the electroless plating solution are preferably present inside the polymer substrate, and in particular, the substance that dissolves in the electroless plating solution is preferably a water-soluble material.

  The substance that dissolves in the electroless plating solution (hereinafter also referred to as an elution substance) is arbitrary as long as it is a material that dissolves in the electroless plating liquid mainly composed of water or alcohol. Soluble low molecular weight materials are preferred. As the water-soluble substance, for example, mineral components such as calcium oxide and magnesium oxide, polyalkyl glycol and the like can be used. Moreover, as a soluble low molecular weight substance, polyalkyl glycols, such as epsilon caprolactam and polyethylene glycol, etc. can be used, for example. In addition, although the size of the particle | grains of the elution substance impregnated at the polymer base material can be suitably adjusted with the molecular weight of the substance melt | dissolved in an electroless-plating liquid, a preferable particle size is about 10 nm-1 micrometer. The reason for this is that when the particle size is smaller than 10 nm, the anchor effect of the plating film is not sufficiently obtained, and when the particle size is larger than 1 μm, the surface of the polymer member is excessively roughened, and the metallic luster is obtained in the plating film. This is because there is a risk of disappearing.

In the polymer member , it is preferable that voids exist inside the polymer base material. As used herein, “void” refers to a void having a size of about 10 nm to 100 μm. This can be formed, for example, by foaming high-pressure carbon dioxide that has penetrated the polymer substrate, as will be described later. If the gap is smaller than 10 nm, the cell (void) density is reduced and the anchor effect of the plating film is reduced. If the gap is larger than 100 μm, the mechanical properties and smoothness of the surface of the polymer member may be remarkably lowered. There is. The size of the gap can be appropriately adjusted by a method of changing the pressure when the molten resin is filled in the mold, the core back method of the mold, or the like when the polymer member is molded.

According to a first 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, wherein the surface is impregnated with metal particles and particles of a substance that dissolves in an electroless plating solution. Preparing a polymer substrate; contacting the polymer substrate with high pressure carbon dioxide to swell the vicinity of the surface of the polymer substrate; and swelling the vicinity of the surface of the polymer substrate. There is provided a manufacturing method comprising contacting an electroless plating solution containing carbon with the polymer substrate to form a plating film on the polymer substrate.

  The term “high-pressure carbon dioxide” as used herein means not only supercritical carbon dioxide but also high-pressure liquid carbon dioxide and high-pressure carbon dioxide gas. In addition, the high pressure as used in this specification means the pressure of 5 MPa or more. The “electroless plating method” as used herein refers to a method of depositing a metal film using a reducing agent on the surface of a substrate having catalytic activity without using an external power source.

  When the present inventors diligently examined the electroless plating method using the electroless plating solution containing supercritical carbon dioxide disclosed in Patent Document 2 and Non-Patent Document 1, etc., metal fine particles are formed inside the surface. Simply contacting the impregnated polymer substrate (polymer substrate containing metal fine particles in the vicinity of the surface) with an electroless plating solution containing high-pressure carbon dioxide (an electroless plating solution in a state in which a plating reaction occurs) causes the polymer Although an electroless plating film is formed on the surface of the substrate, it has been found that it is difficult to form a plating film having sufficient adhesion. According to the verification experiment of the present inventors, in this case, the plating film grows mainly using metal fine particles present on the outermost surface of the polymer substrate as a catalyst nucleus (the plating film is inside the polymer substrate). It has been found that the physical anchor effect of the plating film is difficult to obtain. Therefore, simply contacting an electroless plating film in a state where a plating reaction occurs with a polymer substrate together with high-pressure carbon dioxide did not provide a strong adhesion between the plating film and the polymer substrate. Seem.

On the other hand, in the method for producing a polymer member according to the first aspect of the present invention, first, the surface is dissolved in metal fine particles such as Pd, Ni, Pt, and Cu, which are plating catalyst nuclei, and the electroless plating solution. High pressure carbon dioxide is brought into contact with the polymer substrate impregnated with the substance (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 present 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 aspect of the present invention, the plating film grows using not only the surface of the polymer substrate but also the metal fine particles present inside as the catalyst nucleus. To the inside of the substrate (formed on the polymer substrate in a state where 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 aspect of the present invention, it is not necessary to roughen the surface of the polymer substrate by etching as in the conventional electroless plating method, and various types of polymer substrates can be formed. 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.

Moreover, in the method for producing a polymer member according to the first aspect 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 that of a 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) due to 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 aspect of the present invention, since the elution substance is impregnated inside the surface of the polymer substrate, the electroless plating solution containing high-pressure carbon dioxide is brought into contact with the polymer substrate. At this time, 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 region is caused by the electroless plating solution). Replaced). 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 for producing a polymer member according to the first 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. And forming a polymer base material impregnated with metal fine particles and a substance that dissolves in the electroless plating solution inside the surface.

  As a method of infiltrating the polymer substrate with the particles of the eluting substance and the metal fine particles derived from the metal complex using an injection molding machine, for example, using a technique as described in Patent Document 1, A method may be used in which the metal fine particles and the eluted substance are permeated into the part. This method is suitable because it can infiltrate metal fine particles and eluted substances only near the surface of the molded article (polymer base material) during injection molding, and can reduce various material loss and simultaneously modify various polymer materials. is there. In addition, when a plating film is grown on the surface of the molded article by electroless plating in the same mold after molding, a metal film with high adhesion can be formed simultaneously with injection molding, so a polymer member can be formed at low cost. Can be manufactured. Note that a sandwich molding method may be used as a method of infiltrating the metal base material and the eluted material particles into the polymer substrate using an injection molding machine.

  In addition, the method for infiltrating the metal fine particles and the eluent into the polymer base material is arbitrary. For example, a material obtained by blending the metal fine particles and the eluent and the resin is mixed by extrusion to produce a pellet. Also good. You may mix the resin melt | dissolved in the solvent with the casting method, metal microparticles | fine-particles, and an elution substance. Alternatively, the metal fine particles and the eluent may be dispersed in a varnish such as polyimide and applied to a substrate such as a polyimide sheet and cured.

According to a second 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 base material, the preparation of a polymer base material 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 swelled in the state where the vicinity of the surface of the polymer substrate is swollen. There is provided a manufacturing method comprising contacting a polymer substrate and forming a plating film on the polymer substrate.

In the method for producing a polymer member according to the second aspect of the present invention, as in the method for producing a polymer member according to the first aspect of the present invention, a part of the plating film can be infiltrated into the interior of the polymer substrate. 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 method for producing a polymer member according to the second aspect of the present invention, since voids exist inside the surface of the polymer substrate, when the electroless plating solution containing high-pressure carbon dioxide is brought into contact with the polymer substrate, An 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 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 metal is dissolved into the molten resin of the polymer substrate in the heating cylinder; and the molten resin in which high-pressure carbon dioxide in which the metal complex is dissolved is introduced into the mold It is preferable to include injecting the inside and foaming high-pressure carbon dioxide in the injected molten resin to form a void.

  In the method for producing a polymer member of the present invention, the electroless plating solution preferably contains alcohol.

  According to the study of the present inventor, in the electroless plating method using the electroless plating solution containing supercritical carbon dioxide disclosed in Patent Document 2 and Non-Patent Document 1, etc., the carbon dioxide and the aqueous solution are in a high pressure state. It has been found that the electroless plating solution is difficult to be compatible even if a surfactant is used, and it is necessary to increase the stirring effect. Specifically, it has been found that it is necessary to use a stirrer with high stirring torque or a high-pressure vessel with a shallow bottom. That is, in order to obtain a stable emulsion by uniformly mixing the electroless plating solution and high-pressure carbon dioxide, it has been found that there are large restrictions on the shape of the high-pressure vessel and the stirrer and the rotation speed of the stirrer.

  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, normally, when preparing an electroless plating solution, the stock solution containing metal ions, a reducing agent, etc. is diluted with water according to, for example, the component ratio recommended by the manufacturer, and the plating solution is bathed. In the method for producing a polymer member, 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 this invention is arbitrary, Methanol, ethanol, n-propanol, isopropanol, butanol, heptanol, ethylene glycol, etc. can be used.

  Further, in the method for producing a polymer member of the present invention, when alcohol is added to the electroless plating solution, the surface tension of the electroless plating solution to which alcohol is added is remarkably low because the alcohol has a lower surface tension than water. descend. 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 method for producing a polymer member of the present invention, 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.

  As the surfactant, it is desirable to select and use at least one of known nonionic, anionic, cationic and zwitterionic surfactants. In particular, it is desirable to use various surfactants that have been confirmed to be effective for forming an emulsion of supercritical carbon dioxide and water. For example, polyethylene oxide (PEO) -polypropylene oxide (PPO) block copolymer, ammonium carboxylate perfluoropolyether (PFPE), PEO-polybutylene oxide (PBO) block copolymer, octaethylene glycol monododecyl ether, etc. Can do.

  In the method for producing a polymer member of the present invention, 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 of the present invention, 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 thickness of the plating film, after forming the electroless plating film on the polymer substrate by the above method of the present invention, the conventional plating method (electroless plating method and (Or electroplating 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 method for producing a polymer member of the present invention, the pH of the electroless plating solution may be adjusted to be high in advance. 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 a polymer member of the present invention, Ni, Co, Pd, Cu, Ag, Au, Pt, Sn or the like can be used as the metal to be a plating film, and these are nickel sulfate in an electroless plating solution. , Supplied from metal salts such as palladium chloride 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.

  Various known additives may be added to the electroless plating solution. For example, a complexing agent such as citric acid, acetic acid, succinic acid, or lactic acid that forms a stable soluble complex with metal ions in the electroless plating solution may be added. Moreover, you may add sulfur compounds, such as thiourea, lead ion, a brightener, and a wetting agent (surfactant) as a stabilizer of an electroless plating solution.

  The material for forming the polymer substrate that can be used in the production method of the present invention 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.

  In the method for producing a polymer member of the present invention, the form and production method of the polymer base material are arbitrary. For example, a sheet or pipe produced by extrusion molding, a polymer molded article produced by ultraviolet curing or injection molding, and the like. Can be used. 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 polymer member of the present invention, since a part of the metal film formed on the polymer base material penetrates into the surface of the polymer base material, the polymer member having a metal film with more excellent adhesion is obtained. can get.

  According to the method for producing a polymer member of the present invention, since the electroless plating solution is allowed to penetrate into the inside of the polymer substrate to cause a plating reaction, it is not necessary to roughen the surface of the polymer substrate as in the past, A plating film having excellent adhesion can be formed on all types of polymer substrates.

  In addition, according to the method for producing a polymer member of the present invention, a plating film can be grown by infiltrating an electroless plating solution into a region occupied by an elution substance impregnated inside a polymer substrate or a void. Even when a material such as a crystalline material whose internal free volume is difficult to expand is used as a polymer substrate, a region (space) where an electroless plating film grows easily in the polymer substrate is secured. be able to.

  Furthermore, according to the method for producing a polymer member of the present invention, since a plating film grows in a region occupied by an elution substance impregnated inside the polymer base material or a void, plating with a complicated shape inside the polymer base material is performed. A film region can be formed, and a plating film having stronger adhesion can be formed.

  Hereinafter, although the Example of the manufacturing method of the polymer member of this invention is described concretely, referring drawings, the Example described below is a suitable specific example of this invention, and this invention is not limited to this.

  Example 1 describes a method of forming an electroless plating film on the surface of a polymer substrate by batch processing.

  In this embodiment, a camera lens module mount used in a mobile phone or a digital camera is used as the polymer base material. A schematic cross-sectional view of the polymer substrate of this example is shown in FIG. As shown in FIG. 2, the camera lens module 101 includes a mount 102 having an inner hole 108, a lens 104, and a lens holder 103 that fixes the lens 104. 2A is a diagram when the mount 102 and the lens holder 103 are disassembled, and FIG. 2B is a diagram when the mount 102 and the lens holder 103 are combined. As shown in FIG. 2A, the lens holder 103 is provided with an inner hole 107, and the lens 104 is fixed to the inner hole 107. An imaging element such as a C-MOS sensor (not shown) is fixed to the lower part of the camera module 101.

  As shown in FIG. 2A, a screw groove 105 is formed on the outer wall of the lens holder 103, and the upper end portion of the inner wall 108 of the mount 102 is fitted with the screw groove 105 of the lens holder 103. A thread groove 106 is formed. By fitting the screw groove 105 of the lens holder 103 with the screw groove 106 of the mount 102, the mount 102 and the lens holder 103 are combined as shown in FIG.

  In the camera lens module 101 used in a mobile phone, a digital camera, or the like, a subject image is formed on a sensor such as an image sensor such as a CCD or C-MOS by the lens 104, but due to electric signal noise from the mobile phone body. As a method for suppressing the adverse effect on the module, it is desirable to shield the mount 102 adjacent to the image sensor with an electromagnetic wave. However, when a plating film is formed on the entire mount 102, if the inner wall surface of the mount 102 is a metallic gloss film, light is reflected inside the mount 102, which causes ghost flare. Therefore, in the final step of the polymer member manufacturing method of this example, the surface of the mount 102 was subjected to black electroless plating.

  Further, in this example, reinforced polyphthalamide containing 65% glass fiber and mineral (Amodel AS-1566HS manufactured by Solvay Advanced Polymer) was used as a material for forming the polymer substrate 102 (mount).

[Plating equipment]
A schematic configuration diagram of the plating apparatus used in Example 1 is shown in FIG. As shown in FIG. 1, the plating apparatus 100 mainly includes a carbon dioxide cylinder 21, a filter 26, a high-pressure syringe pump 20, and a high-pressure container 1, and these components are connected by a pipe 27. As shown in FIG. 1, manual valves 22 to 24 for controlling the flow of high-pressure carbon dioxide are provided at predetermined positions on the piping 27 that connects the components.

  As shown in FIG. 1, the high-pressure container 1 (high-pressure container main body) includes a container main body 2 in which an electroless plating solution 8 and a polymer base material 102 (polymer) are accommodated, and a lid 3. The lid 3 is provided with a polyimide seal 4 containing a known spring, and the high pressure gas is sealed inside the high pressure vessel 1 by the polyimide seal 4. A holding member 5 that can suspend and hold a plurality of polymer base materials 102 in the electroless plating solution 8 is provided on the surface (lower surface) of the lid 3 on the plating solution 8 side. On the other hand, a magnetic stirrer 6 for stirring the electroless plating solution 8 is provided at the bottom of the container body 2. Further, the container body 2 has a temperature control flow path 7, and the temperature control water whose temperature is controlled by a temperature controller (not shown) is caused to flow into the temperature control flow path 7. The temperature is adjusted. In this example, the temperature can be adjusted at any temperature from 30 ° C. to 145 ° C. Further, as shown in FIG. 1, a high-pressure carbon dioxide inlet 25 is provided in the side wall of the container body 2.

  In this example, SUS316L was used as a material for forming the high-pressure vessel 1. This is for the following reason. In addition, as a forming material of the high-pressure vessel 1, it is desirable to use a material that is not easily corroded, and SUS316, SUS316L, Inconel, Hastelloy, titanium, or the like can be used.

  In this example, a film (hereinafter referred to as a non-plated growth film) made of DLC (diamond-like carbon) is formed on the inner wall surface of the high-pressure vessel 1 by CVD (Chemical Vapor Deposition). . This is due to the following reason.

  In a conventional electroless plating method, a resin container is generally used as a plating solution container. For example, high-pressure carbon dioxide as described in Patent Document 2 and Non-Patent Document 1 is included in the plating solution. In the method of plating, it is necessary to carry out the plating reaction in a high-pressure vessel, that is, a metal vessel that requires pressure resistance. However, according to the verification experiment of the present inventors, when a metal material such as SUS is used for the high-pressure vessel, a plating film grows on the surface of the high-pressure vessel that is not the object to be plated (polymer base material), and a plating bath is formed. As a result, it was found that it was difficult to grow a uniform metal film on the plating object. In addition, since the adhesion of the plating film grown on the container surface is poor, the plating film grown on the container surface peels off during plating, and there is a problem that the plating object (polymer substrate) is mixed as a foreign object. I found out that That is, in the method of plating by including high-pressure carbon dioxide in an electroless plating solution, when a metal high-pressure vessel is used as a container for the electroless plating solution, industrialization is difficult due to the problems described above. It has been found.

  In order to solve the above problem, in this embodiment, a non-plated growth film (DLC) is formed on the inner wall surface of the high-pressure vessel 1 so that the plating film does not grow on the inner wall of the vessel. The material for forming the non-plated growth film is arbitrary as long as the plating film does not grow on the surface. For example, a dense carbon film such as diamond-like carbon (hard carbon film) or a thin film of an organic substance such as PTFE (polytetrafluoroethylene) or PEEK (polyetheretherketone) that is not easily affected by supercritical carbon dioxide is used. it can. These thin films can be formed using high-frequency plasma CVD, sputtering, thermal spraying, painting, or the like. Alternatively, a stable metal film such as gold (Au) or titanium may be coated by plating or sputtering.

  In this example, nickel-phosphorus was used as the electroless plating solution 8. Note that nickel-boron, palladium, copper, silver, cobalt, or the like may be used as the electroless plating solution. The electroless plating solution 8 is preferably a solution that can be plated with a neutral or weakly alkaline to acidic bath. In the case of nickel-phosphorus, it can be used in a pH range of 4 to 6. Depending on the conditions of the electroless plating solution 8 before introducing high-pressure carbon dioxide, the pH of the electroless plating solution 8 is lowered by infiltrating (introducing) the high-pressure carbon dioxide into the electroless plating solution. Since the concentration may increase and the adverse effect such as a decrease in the deposition rate of the plating film may occur, the pH of the electroless plating solution 8 may be increased in advance.

  In this example, Nicolon DK manufactured by Okuno Pharmaceutical Co., Ltd. containing a metal salt of nickel sulfate, a reducing agent, and a complexing agent was used as a stock solution of the electroless plating solution 8. Further, alcohol was mixed with the electroless plating solution 8. The type of alcohol that can be used in this example is arbitrary, and methanol, ethanol, n-propanol, isopropanol, butanol, heptanol, ethylene glycol, and the like can be used. In this example, ethanol was used. More specifically, the ratio of each component in 1 l of the electroless plating solution is as follows: 150 ml of stock solution (Nicolon DK manufactured by Okuno Seiyaku Co., Ltd.) containing a metal salt of nickel sulfate and a reducing agent or complexing agent, 350 ml of water, And alcohol (ethanol) was made into 500 ml. That is, the proportion of alcohol in the electroless plating solution 8 was 50%. In addition, since nickel sulfate was insoluble in alcohol, it was found that when the amount of alcohol added exceeds 80%, a large amount of nickel sulfate precipitates, which makes it impossible to apply.

  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 alcohol is added to the plating solution. Therefore, it is more preferable. However, in the present invention, a surfactant may be added or the electroless plating solution may be stirred in order to further improve the compatibility (affinity) between the high pressure carbon dioxide and the electroless plating solution. In this example, as described later, a surfactant was added to the electroless plating solution, and the electroless plating solution was also stirred.

  In this example, 3 wt% of octaethylene glycol monododecyl ether as a surfactant was further added to the electroless plating solution 8.

  In the syringe pump 20 of the plating apparatus 100 used in this embodiment, when the pressure inside the high-pressure vessel 1 and the density of high-pressure carbon dioxide are changed by controlling the pressure constant with the manual valves 22 and 23 opened. In addition, the pressure fluctuation can be absorbed, whereby the pressure inside the high-pressure vessel 1 can be stably maintained.

[Method for producing polymer member]
First, a polymer substrate 102 (mount) in which metal fine particles penetrated into the surface was prepared (prepared) as follows. The polymer substrate 102 having a predetermined shape shown in FIG. 2 was molded by injection molding. Next, the polymer base material 102 and the metal complex after molding were mounted in a high-pressure vessel (not shown) of a surface modification device (not shown). At this time, the polymer substrate 102 is held in the high-pressure vessel so that the entire surface of the polymer substrate 102 is in contact with supercritical carbon dioxide (hereinafter referred to as supercritical carbon dioxide) that is introduced into the high-pressure vessel later. did. In this example, hexafluoroacetylacetonato palladium (II) was used as the metal complex.

  Next, 15 MPa of supercritical carbon dioxide was introduced into the high-pressure vessel. At this time, the metal complex charged in the high-pressure vessel is dissolved in supercritical carbon dioxide and penetrates into the entire surface of the polymer substrate 102 together with the supercritical carbon dioxide. Next, by maintaining the pressure in the high-pressure vessel at 120 ° C. for 30 minutes, a part of the metal complex that has permeated the entire surface of the polymer substrate 102 is reduced. In this example, the polymer base material 102 in which the metal fine particles penetrated into the inside of the surface was produced in this way (step S11 in FIG. 12). FIG. 3 shows this state, and the black circles in FIG. 3 are the metal fine particles penetrating the inside of the surface of the polymer substrate 102.

  Next, after attaching the polymer base material 102 manufactured as described above to the holding member 5 of the lid 5 of the high-pressure vessel 1 shown in FIG. 1, the polymer base material 102 is inserted into the container body 2. The lid 3 was closed and the high-pressure vessel 1 was sealed. The container main body 2 is filled with 70% of the inner volume of the container main body 2 in advance, and the container main body 2 is sealed with the lid 3 so as to contain the surfactant and alcohol. 8 is in a state where a plurality of polymer base materials 102 are suspended (state of FIG. 1, step S12 in FIG. 12). However, at this time, the temperature of the high-pressure vessel 1 and the electroless plating solution 8 is 50 or less than the plating reaction temperature (70 ° C. to 85 ° C.) due to the temperature adjustment water flowing through the temperature adjustment flow path 7 of the high-pressure vessel 1. Adjusted to ° C. Therefore, at this time, the polymer base material 102 is in contact with an electroless plating solution at a temperature lower than the plating reaction temperature (a temperature at which the plating reaction does not occur), and the plating film does not grow on the surface of the polymer base material 102. .

  Next, high-pressure carbon dioxide was introduced into the high-pressure vessel 1 that was temperature-controlled at a low temperature where no plating reaction occurred as follows. In this example, supercritical carbon dioxide was used as high-pressure carbon dioxide. First, liquid carbon dioxide taken out from the liquid carbon dioxide cylinder 21 was sucked up by the high-pressure syringe pump 20 through the filter 26, and then the pressure was increased to 15 MPa in the pump (supercritical carbon dioxide was generated). Next, the manual valves 22 and 23 were opened, 15 MPa of supercritical carbon dioxide was introduced into the high-pressure vessel 1 through the inlet 25, and contacted with the polymer substrate 102 (step S13 in FIG. 12). At this time, the surface of the polymer substrate 102 is swollen by the introduced supercritical carbon dioxide, and the surface tension of the plating solution mixed with the supercritical carbon dioxide is low. It penetrates into the polymer substrate 102 together with the critical carbon dioxide. As a result, the electroless plating solution 8 reaches the metal fine particles existing inside the polymer substrate 102. In this example, since the electroless plating solution 8 contains alcohol, the surface tension of the electroless plating solution 8 is further reduced, so that the electroless plating solution 8 is more easily penetrated into the polymer substrate 102. .

  In this example, after the introduction of supercritical carbon dioxide, the electroless plating solution 8 was agitated by rotating the magical stirrer 6 at a high speed. As described above, in this example, since the electroless plating solution contains alcohol, the phase between the supercritical carbon dioxide and the plating solution can be obtained without diffusing the electroless plating solution 8 by using the magical stirrer 6. Although sufficient solubility can be ensured, in this example, the electroless plating solution 8 was agitated with a magical stirrer 6 in order to increase the compatibility between the supercritical carbon dioxide and the plating solution.

  Next, the temperature of the high-pressure vessel 1 was raised to 85 ° C., and a plating reaction was caused in the high-pressure vessel 1 (electroless plating was performed) to form a plating film on the surface of the polymer substrate 102 (in FIG. 12). Step S14). At this time, in the manufacturing method of the polymer member of this example, since the electroless plating solution penetrates to the metal fine particles existing inside the polymer substrate 102 as described above, only the surface of the polymer substrate 102 is used. Instead, the plating film grows using the metal fine particles existing inside as catalyst nuclei. That is, in the polymer member manufacturing method of this example, the plating film grows also in the free volume inside the polymer base material 102, and a part of the plating film penetrates into the polymer base material 102 (the plating film is A plating film is formed on the polymer base material 102 in a state of being bitten into the polymer base material 102.

  After the end of plating, the magnetic stirrer 6 was stopped and allowed to stand for a while to separate the carbon dioxide and the plating solution into two phases in the high-pressure vessel 1. Thereafter, the manual valve 22 was closed, the manual valve 24 was opened, and the carbon dioxide in the high-pressure vessel 1 was exhausted. Next, the high-pressure vessel 1 was opened, and the polymer member 102 was taken out from the high-pressure vessel 1. When the taken-out polymer member 102 was visually confirmed, metallic luster was observed on the entire surface of the polymer substrate 102.

  Next, in order to degas the carbon dioxide and the electroless plating solution from the inside of the polymer substrate 102 taken out from the high-pressure vessel 1, the polymer substrate 102 was annealed at 150 ° C. for 1 hour. Next, the oxidized plating film surface was activated with hydrochloric acid. After that, electroless plating is performed at atmospheric pressure using a conventional electroless nickel-phosphorus solution in the atmosphere, a 500 nm plating film is laminated, and further, 1 μm of electroless copper plating is laminated thereon, and an electromagnetic wave shield. A membrane was applied. Next, black electroless plating was performed, and a black electroless nickel-phosphorous plating film was laminated on the electroless copper plating film. The blackening was performed by plating using a dedicated electroless nickel-phosphorous plating solution and then roughening the surface by etching. This is because the inner wall of the polymer substrate 102 (mount) is blackened to suppress ghost flare due to light reflection. In this example, as described above, a polymer member was obtained in which the entire surface of the polymer substrate 102 as shown in FIG. 4 was covered with a metal film (reference number 300 in FIG. 4).

[Evaluation of plating film]
A high temperature and high humidity test (conditions: temperature 80 ° C., humidity 90% Rh, standing time 500 hours) and heat cycle test (temperature between 80 ° C. and 150 ° C. are 15 times) When the peel test was carried out after performing (cycle), film peeling did not occur. Further, when the above process of this example was repeated, no growth of the plating film or corrosion of the inner wall of the container was observed inside the high pressure container 1.

  Moreover, the cross section of the surface vicinity of the polymer member produced in this example was observed with SEM (scanning electron microscope). The results are shown in FIG. A region 102a in FIG. 5 is a region of the polymer base material 102 where the plating film is not formed, and a region 102b is a layer (second region) in which a part of the plating film penetrates into the polymer base material 102. It is. A region 102c in FIG. 5 is a region of a metal film formed when electroless plating is performed at normal pressure using a conventional electroless nickel-phosphorus solution in the atmosphere. The region 102d is a region of the electroless copper plating film. Therefore, the vicinity of the boundary between the region 102 b and the region 102 c is the outermost surface of the polymer substrate 102. As is clear from the observation image of FIG. 5, it was confirmed that a layer in which a metal film was grown was formed inside the polymer substrate 102 (region 102b in FIG. 5). It was also found that part of the plating film penetrated from the surface of the polymer substrate 102 to a depth of about 1 μm. In addition, the penetration depth of the metal film can be appropriately changed depending on the material of the polymer substrate, the process conditions, and the like.

  In this example, when the component analysis of the metal which exists in the inside of the polymer base material 102 was further carried out by XRD (X-ray diffractometer), Ni, P, and Pd were detected. From this result, it was confirmed that Pd derived from the metal complex that penetrated into the polymer member 102 worked as a catalyst, and a Ni—P plating film was grown inside the polymer. In this example, Pd was detected at a position deeper than the penetration depth of the plating film of the polymer substrate 102. Specifically, Pd was detected in a region (first region) from the surface of the polymer substrate 102 to a depth position of about 500 μm.

  In Example 2, as in Example 1, a method of forming an electroless plating film on the surface of a polymer substrate by batch processing will be described. In this example, a high pressure vessel having a structure different from that of Example 1 was used as the high pressure vessel in the plating apparatus. The electroless plating solution used in this example was the same as in Example 1. In this example, similarly to Example 1, a metal film was formed on the surface of the camera lens module mount (mount 102 having the structure shown in FIG. 2). Further, supercritical carbon dioxide was used as high-pressure carbon dioxide introduced into the electroless plating solution.

[Plating equipment]
A schematic configuration diagram of the plating apparatus used in Example 2 is shown in FIG. As shown in FIG. 6, the plating apparatus 200 mainly includes a carbon dioxide cylinder 21, a filter 26, a high-pressure syringe pump 20, and a high-pressure vessel 1 ′, and these components are connected by a pipe 27. ing. In addition, as shown in FIG. 6, manual valves 22 to 24 for controlling the flow of supercritical carbon dioxide are provided at predetermined positions on the piping 27 that connects the components.

  As shown in FIG. 6, the high-pressure container 1 ′ includes a container main body 2, a lid 3, and an internal container 9 accommodated in the container main body 2. The lid 3 has the same structure as that of the first embodiment except that the lid 3 does not include a holding member that holds the polymer base material 102 as in the first embodiment. The container body 2 of this example has the same structure as that of Example 1 except that the non-plated growth film is not provided on the inner wall surface.

  In the plating apparatus 200 of this example, an inner container 9 made of PTFE (polytetrafluoroethylene) that can be accommodated inside the metal container body 2 is used, and the polymer base material 102 is electrolessly contained in the inner container 9. Plated. In this example, an inner container made of a material that does not grow a plating film is used, and electroless plating is performed in the inner container, so that the plating solution is less likely to come into direct contact with the inner wall of the high-pressure container that houses the inner container, and is stable. Plating. In this case, since it is not necessary to coat the inner wall of the high-pressure vessel, the device is inexpensive. In addition, since the diffusibility of the electroless plating solution in which high-pressure carbon dioxide is dispersed is low, the electroless plating solution hardly leaks out of the inner container. Moreover, as a forming material of the inner container, other than polytetrafluoroethylene (PTFE), a resin material such as polyether ether ketone (PEEK) and polyimide, and a material obtained by mixing an inorganic substance such as glass fiber in the resin material, In addition, as the metal material, a metal material such as titanium, hastelloy, or Inconel can be used.

  As shown in FIG. 6, the inner container 9 includes a container main body portion 9 a in which the electroless plating solution 8 and the polymer base material 102 are accommodated, and a lid portion 9 b. A holding member 5 that can suspend and hold a plurality of polymer base materials 102 in the electroless plating solution 8 is provided on the surface (lower surface) of the lid portion 9b on the electroless plating solution 8 side. The holding member 5 has the same structure as the holding member of the first embodiment. On the other hand, a magnetic stirrer 6 for stirring the electroless plating solution 8 is provided at the bottom of the container body 9a. In addition, a screw groove is formed on the outer wall near the upper end of the container main body 9a, and a screw groove that fits into a screw groove provided on the outer wall of the upper end of the container main body 9a is formed on the inner wall of the lid 9b. Yes. Then, the inner container 9 is closed by fitting the screw groove of the container main body portion 9a and the screw groove of the lid portion 9b.

[Method for producing polymer member]
First, in this example, in the same manner as in Example 1, a polymer base material 102 (mount 102 having the shape shown in FIG. 2) in which metal fine particles penetrated into the surface was prepared (prepared). In this example, hexafluoroacetylacetonato palladium (II) was used as the metal complex.

  Next, after the molded polymer base material 102 is attached to the holding member 5 of the lid portion 9b of the inner container 9 shown in FIG. 6, the polymer base material 102 is inserted into the container main body portion 9a, and the lid portion 9b is attached. Closed. At this time, as shown in FIG. 6, a plurality of polymer base materials 102 are suspended in the electroless plating solution 8 containing a surfactant and alcohol. And this state was hold | maintained at normal temperature. Therefore, at this time, since the temperature of the electroless plating solution 8 is equal to or lower than the plating reaction temperature (70 ° C. to 85 ° C.), the plating film does not grow on the surface of the polymer substrate 102.

  Next, the inner vessel 9 is inserted into the high-pressure vessel 1 ′ that has been temperature-controlled in advance at 90 ° C., the lid 3 is closed, and immediately after the supercritical carbon dioxide is introduced into the inlet 25 in the same manner as in Example 1. And introduced into the high-pressure vessel 1 ′. Thereafter, the electroless plating solution 8 was stirred with a magnetic stirrer 6. At this time, the container body portion 9a and the lid portion 9b of the inner container 9 are fitted with screws as described above. Even in this state, supercritical carbon dioxide has a low viscosity and a high diffusivity. The container 9 is sufficiently introduced into the inner container 9 through a slight gap in the portion engaged with the screw. Further, at this time, since the resin having low thermal conductivity is used for the inner container 9, the temperature in the inner container 9 does not increase rapidly, so that the temperature becomes lower than the temperature at which the plating reaction occurs. In addition, the plating film does not grow on the surface of the polymer substrate 102. Therefore, when the internal container 9 is inserted into the high-pressure container 1 ′ and the supercritical carbon dioxide is immediately introduced, the surface of the polymer substrate 102 swells as in Example 1, and the supercritical carbon dioxide Since the mixed plating solution has a low surface tension, the electroless plating solution penetrates into the inside of the polymer substrate 102 together with the supercritical carbon dioxide, and the electroless plating solution reaches the metal fine particles existing inside the polymer substrate 102. Reach.

  Thereafter, with the passage of time, the temperature in the inner container 9 rises, and finally the temperature of the electroless plating solution 8 etc. rises to the plating reaction temperature. At that time, a plating reaction occurs in the inner container 9 and a plating film grows on the surface of the polymer substrate 102. At this time, in the manufacturing method of the polymer member of this example, since the electroless plating solution penetrates to the metal fine particles existing inside the polymer substrate 102 as described above, only the surface of the polymer substrate 102 is used. Instead, the plating film grows using the metal fine particles existing inside as catalyst nuclei. That is, in the plating film forming method of this example, the plating film is formed on the polymer base material 102 with a part of the plating film penetrating into the polymer base material 102.

  Next, after the plating process described above (about 30 minutes after the insertion of the inner container 9), supercritical carbon dioxide was exhausted from the high-pressure container 1 ′, and the inner container 9 was kept at 90 ° C. as it was. By this process, a plating film was further grown at normal pressure on the plating film grown from the inside of the polymer substrate 102. Thereafter, the inner container 9 was taken out from the high-pressure vessel 1 ′, and then the polymer substrate 102 was taken out from the inner container 9. Next, the polymer base material 102 taken out from the inner container 9 was subjected to electroless copper plating and black electroless nickel-phosphorous plating in the same manner as in Example 1. In this example, as described above, a polymer member having the entire surface as shown in FIG. 4 covered with a metal film (reference number 300 in FIG. 4) was obtained.

[Evaluation of plating film]
When the environmental test (high temperature and high humidity test, heat cycle test) and the adhesion evaluation (peel test) were performed on the polymer member produced as described above in the same manner as in Example 1, the same as in Example 1. In addition, it was found that a plating film having high adhesion was formed on the polymer substrate 102.

  Further, no plating solution was confirmed inside the high-pressure vessel 1 ′ of this example. Therefore, when a resin-made inner container is used as in the present embodiment, the plating does not grow on the inner wall of the high-pressure container 1 ′ without coating the inside of the high-pressure container 1 ′. Plating can be performed. Moreover, since the corrosion of the surface of the high-pressure vessel 1 ′ can be suppressed, the plating apparatus is suitable as a plating film forming method using supercritical carbon dioxide.

  In Example 3, the same plating apparatus as in Example 2 was used except that the surfactant was not added to the electroless plating solution and that the electroless plating solution was not stirred by a magnetic stirrer. Then, a polymer member was produced by subjecting the polymer substrate to electroless plating by the same method.

  Moreover, when the environmental test (high temperature and humidity test, heat cycle test) and adhesion evaluation (peel test) were performed on the polymer member produced in this example in the same manner as in Example 2, Example 2 and Similarly, it was found that a plating film with high adhesion was formed on the polymer substrate. That is, according to the method for producing a polymer member of the present invention, using a surfactant or a magnetic stirrer, even if the affinity (compatibility) between the supercritical carbon dioxide and the electroless plating solution is not improved, It has been found that a plating film having good adhesion can be formed on a polymer substrate.

  In Example 4, the same plating apparatus as in Example 2 except that no alcohol was mixed with the electroless plating solution and that the pressure of supercritical carbon dioxide introduced into the electroless plating solution was increased to 20 MPa. The polymer base material was subjected to electroless plating by the same method to prepare a polymer member.

  Moreover, when the environmental test (high temperature and humidity test, heat cycle test) and adhesion evaluation (peel test) were performed on the polymer member produced in this example in the same manner as in Example 2, Example 2 and Similarly, it was found that a plating film with high adhesion was formed on the polymer substrate. That is, in the method for producing a polymer member of the present invention, the affinity between the aqueous solvent (electroless plating solution) and supercritical carbon dioxide can be increased by using a surfactant and mechanical stirring without using alcohol. I understood that I could do it.

  In Example 5, a polymer base material was applied by the same method as in Example 1 except that the inner wall of the high-pressure vessel of the plating apparatus was not coated with a non-plated growth film. An electroless plating process was performed to produce a polymer member.

  Further, for the polymer member produced in this example, an environmental test (high temperature and humidity test, heat cycle test) and adhesion evaluation (peel test) were conducted in the same manner as in Example 1. Similarly, it was found that a plating film with good adhesion was formed on the polymer substrate. However, in this example, since the non-plated growth film was not formed on the inner wall of the high-pressure vessel of the plating apparatus, the growth and corrosion of the plating film was confirmed on the inner wall of the high-pressure vessel.

[Comparative Example 1]
In Comparative Example 1, the polymer substrate was subjected to electroless plating in the same manner as in Example 4 (when alcohol was not mixed with the electroless plating solution) except that stirring was not performed in the inner container of the plating apparatus. A polymer member was prepared.

  Also, for the polymer member produced in this example, environmental tests (high temperature and humidity test, heat cycle test) and adhesion evaluation (peel test) were conducted in the same manner as in Example 1. The polymer member peeled off the electroless plating film. From this result, it was found that when the alcohol is not mixed with the electroless plating solution, the electroless plating solution needs to be stirred even if the surfactant is added to the electroless plating solution.

[Comparative Example 2]
In Comparative Example 2, a polymer base material into which the electroless plating solution and metal fine particles permeated the inside of the surface was inserted into the inner container of the plating apparatus, and then heated to 80 ° C. Next, in the same manner as in Example 3, the inner vessel was inserted into the high-pressure vessel, and supercritical carbon dioxide was introduced to perform electroless plating. That is, in Comparative Example 2, the temperature of the electroless plating solution brought into contact with the polymer substrate was made substantially constant before and after the introduction of supercritical carbon dioxide.

  Also, for the polymer member produced in this example, environmental tests (high temperature and humidity test, heat cycle test) and adhesion evaluation (peel test) were conducted in the same manner as in Example 1. The polymer member peeled off the electroless plating film. This is because the electroless plating solution was adjusted to the plating reaction temperature before introducing the supercritical carbon dioxide (before bringing the supercritical carbon dioxide into contact with the polymer substrate) in the method for forming the plating film of Comparative Example 2. The plating reaction and plating film are deposited on the surface of the polymer substrate before the electrolytic plating solution penetrates into the polymer substrate, and the electroless plating solution does not penetrate into the polymer substrate. This is probably because the growth of the plating film was hindered.

Table 1 summarizes the form of the high-pressure vessel, the conditions of the electroless plating solution, and the evaluation results in Examples 1 to 5 and Comparative Examples 1 and 2. In addition, the evaluation criteria of the adhesion of the plating film and the corrosivity of the high-pressure inner wall in Table 1 are as follows.
Plating film adhesion:
◎ When there is no problem in the peel test after the environmental test (high temperature and high humidity, heat cycle test) (when there is no peeling of the plating film or film swelling)
○ When there is no problem in the peel test before the environmental test × When peeled off during the peel test before the environmental test Corrosion of the inner wall of the container and growth of the plating film:
○ When there is no rust or plating film growth on the container inner wall × When rust or plating film growth occurs on the container inner wall

  In Example 6, a method of performing electroless plating in the same injection molding machine after injection molding of the polymer substrate using the injection molding machine will be described. In this example, an automobile headlight reflector was manufactured as a polymer member.

[Production equipment for polymer members]
FIG. 7 shows a schematic configuration of the polymer member manufacturing apparatus used in this example. As shown in FIG. 7, the manufacturing apparatus 500 of the present embodiment mainly supplies and discharges a vertical injection molding apparatus section 503 including a mold and an electroless plating solution including high-pressure carbon dioxide to the mold. The electroless plating apparatus section 501 for controlling the pressure and the surface modification apparatus section 502 for infiltrating the high-pressure carbon dioxide in which the metal complex is dissolved in the molten resin in the plasticizing cylinder of the injection molding apparatus section 503.

  As shown in FIG. 7, the vertical injection molding apparatus unit 503 mainly includes a plasticizing and melting apparatus 110 that plasticizes and melts a resin for forming a polymer base material, and a mold clamping apparatus 111 that opens and closes a mold. .

  The plasticizing and melting apparatus 110 mainly includes a plasticizing cylinder 52 with a built-in screw 51, a hopper 50, and a high-pressure carbon dioxide introduction valve 65 provided in the vicinity of a tip portion (flow front portion) in the plasticizing cylinder 52. It consists of. Further, a pressure sensor 40 for measuring the resin internal pressure was provided at a position facing the introduction valve 65 of the plasticizing cylinder 52. In addition, Poniphenylene sulfide (FZ-8600 Black manufactured by Dainippon Ink & Chemicals, Inc.) is used as a material (not shown) for the resin pellet (not shown) supplied from the hopper 50 to the plasticizing cylinder 52. It was.

  The mold clamping device 111 is mainly composed of a fixed mold 53 and a movable mold 54. The movable mold 54 is connected to a movable platen 56 and a hydraulic mold clamping mechanism (not shown) connected to the movable mold 54 in conjunction with the drive. It is structured to open and close between the tie bars 55 of the book. In addition, a plating solution introduction path 61 for supplying and discharging high-pressure carbon dioxide and electroless plating solution to and from a cavity 504 defined between the movable die 54 and the fixed die 53 is provided in the movable die 54. , 62 are formed. The plating solution introduction paths 61 and 62 are connected to a pipe 15 of an electroless plating apparatus unit 501 described later as shown in FIG. 7, and the high pressure carbon dioxide and the electroless plating solution are cavities 504 through the pipe 15. It is a structure that is introduced into. The cavity 504 is sealed by fitting the spring-incorporated seal 17 provided on the outer diameter portion of the fixed mold 53 and the movable mold 54.

  As shown in FIG. 7, the surface reformer unit 502 mainly dissolves the liquid carbon dioxide cylinder 21, the syringe pumps 20, 34, the filter 57, the back pressure valve 48, and the metal complex in high pressure carbon dioxide. It is comprised from the dissolution tank 35 and the piping 80 which connects these components. Further, as shown in FIG. 7, the pipe 80 of the surface reformer unit 502 is connected to the introduction valve 65 of the plasticizing cylinder 52, and the pressure sensor 47 is provided in the pipe 80 near the introduction valve 65. Yes. In this example, a metal complex (hexafluoroacetylacetona palladium (II)) was used as a raw material for the metal fine particles charged in the dissolution tank 35.

  As shown in FIG. 7, the electroless plating apparatus unit 501 mainly includes a liquid carbon dioxide cylinder 21, a pump 19, a buffer tank 36, and a high pressure container 10 that mixes an electroless plating solution and high pressure carbon dioxide, Circulation pump 90, plating tank 11 for replenishing electroless plating solution, syringe pump 33, recovery container 63 for recovering electroless plating solution, recovery tank 12, and piping 15 connecting these components Consists of Further, automatic valves 43 to 46 and 38 for controlling the flow of the high-pressure carbon dioxide and the electroless plating solution are provided at predetermined positions of the pipe 15. Further, as shown in FIG. 7, the pipe 15 is connected to plating solution introduction paths 61 and 62 of the movable mold 54. In this example, as the electroless plating solution, an electroless plating solution obtained by mixing the same alcohol and surfactant as in Example 1 was used, and the composition was the same as in Example 1.

[Method of forming polymer substrate]
Next, a method for forming a polymer base material in which metal fine particles are infiltrated into the surface will be described. In the present invention, the method for infiltrating the metal fine particles into the resin is arbitrary, but in this embodiment, the metal fine particles were dissolved in the tip portion (flow front portion) of the molten resin plasticized and measured in the plasticizing cylinder 52. High pressure carbon dioxide was introduced.

  First, the metal complex was dissolved in ethanol in the dissolution tank 35, and the ethanol in which the metal complex was dissolved was increased to 15 MPa in the syringe pump 34. On the other hand, the liquid carbon dioxide cylinder 21 was supplied to the syringe pump 20 via the filter 53, and the liquid carbon dioxide pressure was increased to 15 MPa in the syringe pump 20. And when supplying the produced | generated high pressure liquid carbon dioxide and the high pressure ethanol in which the metal complex melt | dissolved to the plasticization melting apparatus 110, control of each syringe pump 20 and 34 was switched from pressure control to flow control. At this time, high-pressure liquid carbon dioxide and high-pressure ethanol in which the metal complex is dissolved are fed while being mixed in the pipe 80 (hereinafter, the mixed fluid is referred to as a high-pressure mixed fluid). Note that when the high-pressure mixed fluid was supplied to the plasticizing and melting apparatus 110, the supply pressure of the high-pressure mixed fluid was controlled by the back pressure valve 48 so that the display of the pressure gauge 49 became 15 MPa. Furthermore, when supplying the high-pressure mixed fluid to the plasticizing and melting apparatus 110, the high-pressure mixed fluid was supplied to the plasticizing and melting apparatus 110 while controlling the temperature in the pipe 80 to 50 ° C. with a heater (not shown).

  Next, a procedure for introducing the high-pressure mixed fluid into the plasticizing and melting apparatus 110 will be described with reference to FIGS. 8A and 8B are enlarged cross-sectional views of the vicinity of the introduction valve 65 of the plasticizing and melting apparatus 110. FIG. First, while supplying resin pellets from the hopper 50, the screw 51 in the plasticizing cylinder 52 was rotated to measure plasticization of the resin. FIG. 8A shows a state in the vicinity of the introduction valve 65 when the plasticizing measurement is completed. At this time, as shown in FIG. 8A, the introduction pin 651 of the introduction valve 62 moves backward (moves to the left in FIG. 8A), so that the high-pressure mixed fluid 67 is introduced into the molten resin 66. Is being blocked.

  Next, the screw 51 is sucked back (retracted) to reduce the internal pressure of the molten resin 66, and at the same time, both syringe pumps 20, 34 are switched from pressure control to flow rate control, and ethanol and carbon dioxide in which the metal complex is dissolved. The high-pressure mixed fluid 67 was introduced into the molten resin 66 at the flow front portion in the plasticizing cylinder 52 through the introduction valve 65 (the state shown in FIG. 8B). ). A region 68 in FIG. 8B is a portion of the molten resin into which the high pressure mixed fluid 67 has penetrated.

  In the introduction valve 65 of the plasticizing cylinder 52 of this embodiment, when the pressure difference between the molten resin 66 and the high pressure mixed fluid 67 becomes 5 MPa or more, the high pressure mixed fluid 67 is melted in the plasticizing cylinder 52. The introduction principle of the high-pressure mixed fluid 67 by the introduction valve 65 is as follows. When the screw 51 is sucked back after the plasticization measurement is completed, the molten resin 66 is decompressed and the density is lowered. When the pressure difference between the molten resin 66 and the high pressure mixed fluid 67 becomes 5 MPa or more, the pressure of the high pressure mixed fluid 67 overcomes the return force (elastic force) of the spring 652 in the introduction valve 65, and the introduction pin 651 It advances to the molten resin 66 side, and the high-pressure mixed fluid 67 is introduced into the molten resin 66. The high-pressure mixed fluid 67 was introduced while monitoring the resin pressure and the pressure of the high-pressure mixed fluid 67 with the pressure sensors 40 and 47, respectively.

  Subsequently, both syringe pumps 20 and 34 were stopped, and liquid feeding of the high pressure mixed fluid 67 was stopped. At the same time, the screw 51 is advanced to increase the resin pressure again, and the introduction pin 64 is retracted (moved to the left in FIG. 8B). Thereby, the introduction of the high-pressure mixed fluid 67 was stopped, and the high-pressure mixed fluid 67 and the molten resin 66 were made compatible.

  Next, both syringe pumps 20 and 34 are closed with an automatic valve (not shown) in the pipe 80, and then the flow rate of the ethanol solution in which the high-pressure carbon dioxide and the metal complex are supplied to the plasticizing and melting apparatus 110 is changed to the syringe pump 20 and 34 was refilled. After that, the pressure control was switched to 15 MPa, and the system was kept waiting until the next shot was fed.

  Next, after introducing the high-pressure mixed fluid 67 into the molten resin 66 at the flow front portion in the plasticizing cylinder 52, the mold is clamped by a hydraulic clamping mechanism (not shown) of the clamping device 111, and a temperature control circuit (not shown). The molten resin was injected and filled into the cavity 504 defined in the mold whose temperature was controlled by the above method. Next, in order to suppress foaming of the molded product, a pressure was applied to the mold, and then the molded product was cooled and solidified (state of FIG. 9). When the molten resin is injection-molded into the mold, the molten resin 68 in the flow front portion that is injected first forms the skin of the injection-molded product by the fountain effect (fountain flow). That is, in this example, metal fine particles derived from the metal complex are dispersed in the vicinity of the flow front portion, and therefore, as shown in FIG. 9, the skin 505 (inside the surface) of the polymer substrate 507 is impregnated with the metal fine particles. A base material 507 is obtained (step S61 in FIG. 13). In this example, in this way, a metal base material 507 was obtained in which metal fine particles were dispersed in the skin layer 505 which is the epidermis and almost no metal fine particles were present in the core layer 506 which is the endothelium.

[Method of forming plating film]
The polymer base material 507 in which metal fine particles were dispersed inside the surface produced as described above was subjected to electroless plating treatment in a mold as follows. During the electroless plating process, the temperature inside the mold was adjusted to 80 ° C.

  First, as shown in FIG. 10, the movable platen 56 and the movable mold 54 are moved backward by retreating the hydraulic mold clamping mechanism (not shown) of the mold clamping device 111 (downward in FIG. 10), so that the fixed mold is fixed. A gap 508 (cavity 508) was provided between the mold 53 and the polymer substrate 507.

  Next, the carbon dioxide supplied from the carbon dioxide cylinder 21 of the electroless plating apparatus unit 501 was pressurized by the pump 19 and stored in the buffer tank 36. Next, the automatic valve 43 is opened, and the high-pressure carbon dioxide stored in the buffer tank 36 is introduced into the cavity 508 via the plating solution introduction path 61 to bring the high-pressure carbon dioxide into contact with the surface of the polymer substrate 507. (Step S62 in FIG. 13). At this time, since the cavity 508 is sealed by fitting the spring built-in seal 17 provided on the outer diameter portion of the fixed mold 13 and the movable mold 54, the introduced high-pressure carbon dioxide is introduced to the outside of the mold. There is no leakage. At this time, the pressure of the high-pressure carbon dioxide in the cavity 508 was set to 15 MPa. Thus, since the surface of the polymer substrate 507 swells when the high-pressure carbon dioxide is brought into contact with the surface of the polymer substrate 507, the polymer group of the mixed fluid of the high-pressure carbon dioxide and the electroless plating solution to be introduced next The effect that the penetration into the inside of the material 507 is performed more smoothly is obtained.

  Next, an electroless plating solution containing high-pressure carbon dioxide was introduced into the cavity 508 and brought into contact with the polymer substrate 507 as follows. First, an alcohol and surfactant-mixed electroless plating solution supplied from the plating tank 11 of the electroless plating apparatus unit 501 and a 15 MPa high-pressure carbon dioxide supplied from the buffer tank 36 in advance are stored in the high-pressure vessel 10. And mixed. The electroless plating solution of this example was prepared so that the ratio of each component contained therein was the same as in Example 1. At this time, the high-pressure carbon dioxide and the electroless plating solution were dissolved in the high-pressure vessel 10 by driving the stirrer 16 and rotating the magnetic stirrer 17 at high speed. Subsequently, the automatic valve 43 was closed and the automatic valves 44 and 45 were opened.

  Next, the circulation pump 9 is operated, and an electroless plating solution containing high-pressure carbon dioxide is circulated through a circulation flow path including the high-pressure vessel 10, the pipe 15, and the cavity 508, so that the electroless plating solution is formed on the surface of the polymer substrate 507. Was contacted to form a plating film (nickel-phosphorus film) (step S63 in FIG. 13). At this time, since the surface of the polymer molded product 507 is swollen, the electroless plating solution penetrates from the surface of the polymer base material 507 into the polymer base material 507 and the metal fine particles dispersed inside the polymer base material 507 are dispersed. A plating film grows as a catalyst nucleus. That is, the plating film grows in a state where a part of the plating film formed on the polymer base material 507 has permeated (a state in which the plating film formed on the polymer base material 507 bites into the polymer base material 507). Therefore, a plating film having excellent adhesion is formed. When the electroless plating solution containing high-pressure carbon dioxide is circulating, the pressures in the cavity 508 and the circulation line 15 are the same by the pressure sensors 58 and 59. Further, replenishment of the electroless plating solution was performed at any time by increasing the pressure of the plating solution supplied from the plating tank 11 with the syringe pump 33 and feeding it simultaneously with the opening of the automatic valve 46.

  Next, after forming a plating film on the polymer substrate 507 as described above, the electroless plating solution containing high-pressure carbon dioxide is recovered through the collection vessel 63 from the circulation path of the electroless plating solution containing high-pressure carbon dioxide. The tank 12 was evacuated. Specifically, the automatic valves 44 and 45 were closed, and then the automatic valve 38 was opened, whereby the electroless plating solution containing high-pressure carbon dioxide was discharged into the collection container 16. In the collection container 63, the electroless plating solution containing the collected high-pressure carbon dioxide is separated into an aqueous solution (plating solution) and a high-pressure gas (carbon dioxide) by the principle of centrifugation. The plating solution can be recovered in the recovery tank 12 and reused. The gasified carbon dioxide is discharged from the upper part of the recovery container 63 and recovered in an exhaust duct (not shown).

  Next, the automatic valve 43 is opened for a certain period of time, high-pressure carbon dioxide is introduced into the gap 508 (cavity 508) between the fixed mold 53 and the polymer substrate 507, and the plating solution residue remaining in the cavity 508 is pressurized. It was discharged out of the mold together with carbon dioxide. Next, when the internal pressure of the cavity 508 became zero as monitored by the pressure sensor 59, the mold was opened and the polymer substrate 507 was taken out.

  Next, the extracted polymer base material 507 was subjected to normal substitutional gold plating, and a gold plating film was laminated on the surface of the polymer base material 507. In this example, a polymer member having a plated film formed on a polymer substrate was obtained as described above.

  A schematic sectional view of a part of the polymer member produced in this example is shown in FIG. It was confirmed that metal fine particles 600 (black circles in FIG. 11) were dispersed inside the skin layer 505 of the polymer member produced in this example (in this example, this skin layer was impregnated with metal fine particles. It becomes the first area). Further, a nickel-phosphorous plating film 509 (metal film) grown in a mold is formed on one side of the polymer base 507, and the nickel-phosphorous plating film 509 grows from the inside of the polymer base 507. (The permeation layer 509a (second region) of the plating film 509 was formed). The penetration depth of the plated film of the polymer member produced in this example into the polymer substrate 507 is about 200 nm, and Pd (metal fine particles) 600 exists at a deeper position as shown in FIG. Was. Specifically, the depth of the skin layer (the first region impregnated with Pd) was about 100 μm. Further, a gold high reflection film 510 is formed on the nickel-phosphorus plating film 509.

  In addition, the adhesion evaluation of the metal film was also performed on the polymer member produced in this example in the same high temperature and high humidity environment test as in Example 1. A high temperature test was also conducted under conditions of a temperature of 150 ° C. and a standing time of 500 hours. As a result, the same results as in Example 1 were obtained, and no decrease in the adhesion of the metal film was observed. Furthermore, when the surface roughness Ra of the polymer member produced in this example was measured, Ra = 100 nm, which is equivalent to the surface roughness of the mold. That is, according to the method for producing a polymer member of this example, the plating process can be performed simultaneously with the injection molding, and not only the process can be simplified, but also a metal film having a high adhesion and a smooth heat resistance can be obtained. It was found that it can be formed into a high resin material.

  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. However, 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 in more detail. An electroless plating solution (first electroless plating solution) and a high-pressure carbon dioxide having 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 present invention is not limited to this. You may shape | mold the polymer base material in which the metal microparticles impregnated the inside of the surface 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 Example 7, a method of performing electroless plating in the same injection molding machine after injection molding of a polymer substrate using the same injection molding machine as in Example 6 will be described. In this example, as in Example 6, a reflector for an automobile headlight was produced as a polymer member, and Poniphenylene sulfide (FZ-8600 Black, manufactured by Dainippon Ink & Chemicals, Inc.) was used as the polymer base material. . In addition, a metal complex (hexafluoroacetylacetona palladium (II)) was used as a raw material for the metal fine particles.

  In this example, polyethylene glycol having an average molecular weight of 1000 (material dissolved in electroless plating solution: eluent), which is a water-soluble material, is melted by plasticizing and weighing in a plasticizing cylinder (heating cylinder). The tip of the resin (flow front part) was introduced and impregnated on the surface of the polymer substrate. Specifically, the metal complex and polyethylene glycol are dissolved in ethanol in the dissolution tank 35, and a mixed high-pressure fluid of ethanol in which the metal complex and polyethylene glycol are dissolved and high-pressure carbon dioxide is added to the tip of the molten resin (flow front). Part). Other than that was carried out similarly to Example 6, and produced the polymer member of a present Example.

  In this example, the metal complex and polyethylene glycol were introduced into the flow front portion of the molten resin in the plasticizing cylinder 52, and the polymer base material was injection molded, so the skin layer (inside the surface) of the polymer base material was A polymer base material that is impregnated with metal fine particles and polyethylene glycol and in which the metal fine particles and polyethylene glycol are hardly permeated is obtained (step S71 in FIG. 20). FIG. 14 shows this state, and FIG. 14 is a schematic cross-sectional view of the vicinity of the surface of the polymer substrate molded in this example (a part of the skin layer). In the vicinity of the surface of the polymer substrate immediately after molding in this example, metal fine particles 600 and polyethylene glycol 601 are dispersed as shown in FIG. In addition, when the particle size of the polyethylene glycol 601 impregnated inside the polymer substrate molded in this example was examined by EPMA (Electron Probe Micro Analyzer), it was about 50 nm.

  Next, in the same manner as in Example 6, the polymer base material in which the skin layer as shown in FIG. 14 is impregnated with the metal fine particles 600 and the polyethylene glycol 601 is brought into contact with an electroless plating solution containing high-pressure carbon dioxide. Thus, a plating film was formed on the polymer substrate (steps S62 and S63 in FIG. 20).

  When an electroless plating solution containing high-pressure carbon dioxide is brought into contact with the surface of the polymer substrate having a swollen surface, the electroless plating solution penetrates into the polymer substrate and reaches polyethylene glycol 601. At this time, since the polyethylene glycol 601 is a water-soluble substance, the polyethylene glycol 601 elutes in water and alcohol, which are the main components of the electroless plating solution, and the polyethylene glycol 601 does not occupy the area occupied (existing). The electrolytic plating solution enters (the region occupied by the polyethylene glycol 601 is replaced with the electroless plating solution). As a result, the electroless plating film grows even in the region occupied by the polyethylene glycol 601 (region replaced with the electroless plating solution). Thus, in this embodiment, since the plating film can be grown in the region where the polyethylene glycol 601 was present, a crystalline material in which the free volume inside the polymer is difficult to expand is used as the polymer substrate forming material. Even if it is used, it is possible to secure a region where the electroless plating film grows easily inside the polymer substrate.

  FIG. 15 shows the state of the interface between the polymer substrate and the plating film when the plating film is formed on the polymer substrate by the manufacturing method of this example. In this example, the plating film grows not only around the metal fine particles 600 impregnated in the polymer substrate but also in the region where the polyethylene glycol 601 was present (the region surrounded by the broken line 603 in FIG. 15). As shown in FIG. 15, the plating film 602 grows in a very complicated shape inside the polymer base material, and a continuous plating film from the inside of the polymer base material can be formed on the polymer base material. Therefore, a plating film having higher adhesion is formed. As shown in FIG. 15, in the region of polyethylene glycol 601 where the electroless plating solution has not reached, polyethylene glycol 601 does not elute and remains in the polymer substrate as it is.

  Also for the polymer member produced in this example, the adhesion evaluation of the metal film was performed in the same high temperature and high humidity environment test as in Example 1. A high temperature test was also conducted under conditions of a temperature of 150 ° C. and a standing time of 500 hours. As a result, the same results as in Example 1 were obtained, and no decrease in the adhesion of the metal film was observed. Furthermore, when the surface roughness Ra of the polymer member produced in this example was measured, Ra = 100 nm, which is equivalent to the surface roughness of the mold. That is, according to the plating film forming method of this example, the plating process can be performed simultaneously with the injection molding, and not only can the process be simplified, but also a metal film having high adhesion and smoothness can be made heat resistant. It was found that it can be formed into a high resin material.

  Further, in the polymer member produced in this example, the penetration depth of the plating film into the polymer substrate is about 200 nm, and the metal fine particles (Pd) are deeper than that, specifically, to a depth of about 100 μm. ) Existed.

  In this example, an example in which polyethylene glycol was used as a water-soluble substance in order to form a sufficient plating film growth region inside the polymer substrate was described, but the present invention is not 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.

  In Example 8, a method of performing electroless plating in the same injection molding machine after injection molding of a polymer substrate using the same injection molding machine as in Example 6 will be described. In Example 7, an example in which polyethylene glycol, which is a water-soluble substance, is infiltrated into the surface of the polymer substrate together with the metal fine particles to form a sufficient plating film growth region inside the polymer substrate. In Example 8, an example will be described in which a fine foamed cell (void) is formed inside a polymer substrate to form a sufficient plated film growth region inside the polymer substrate. A polymer substrate was formed in the same manner as in Example 7 except that fine foam cells were formed inside the polymer substrate, and a plating film was formed on the polymer substrate.

  In this example, as in Example 6, a reflector for an automobile headlight was prepared as a polymer substrate, and the material for forming the polymer substrate was Poniphenylene Sulfide (FZ-8600 Black, manufactured by Dainippon Ink & Chemicals, Inc.). Was used. In addition, a metal complex (hexafluoroacetylacetona palladium (II)) was used as a raw material for the metal fine particles.

  A method for forming fine foam cells inside the polymer substrate of this example will be described with reference to FIGS.

  First, in the same manner as in Example 7, high-pressure carbon dioxide in which a metal complex (metal fine particles) was dissolved was introduced into the tip portion (flow front portion) of the plasticized and measured molten resin in the plasticizing cylinder (in FIG. 22). Step S81A). Next, in the same manner as in Example 7, the molten resin was injected and filled into the cavity of the mold (step S81B in FIG. 22). FIGS. 16 to 18 show the situation at the time of injection filling of the molten resin.

  First, when the molten resin 701 (metal fine particles 705 and carbon dioxide are dispersed or dissolved) in the flow front portion is filled in the cavity, the molten resin 701 is made of gold by the fan unten flow effect (fountain effect). It is pulled by the mold wall surface 703 (behaves as indicated by an arrow 702 in FIG. 16), and forms a skin layer of the polymer substrate. Subsequently, a molten resin not containing metal fine particles 705 and carbon dioxide is filled to form a core layer of a polymer substrate.

  When the molten resin 701 in the flow front portion is filled, the carbon dioxide is depressurized inside the surface of the mold 703 to form a foam cell 704 as shown in FIG. As the filling further proceeds, carbon dioxide is easily discharged in the vicinity of the surface 706 of the filling resin in contact with the mold wall surface 703, so that clear foam cells are almost disappeared. As a result, as shown in FIG. 17, it is considered that the foam cell 704 remains in a region slightly inside the surface vicinity 706 of the polymer substrate. Next, after injection filling, the mold clamping pressure of the mold was reduced without applying holding pressure, and the filled resin internal pressure was rapidly reduced. As a result, as shown in FIG. 18, a finer foam cell 708 than the foam cell 704 in FIG. 17 is formed in a region slightly inside (inner side of the polymer base material) near the surface 706 of the polymer base material. (Step S81C in FIG. 22). Next, in the same manner as in Example 7, the polymer substrate was taken out from the mold. In this example, a polymer base material having fine foam cells formed therein was obtained as described above (step S81 in FIG. 21).

  Next, in the same manner as in Example 7, a mixed fluid of high-pressure carbon dioxide and electroless plating solution was brought into contact with the polymer substrate to form a plating film (Steps S82 and S83 in FIG. 21). At this time, the electroless plating solution penetrates into the foam cell 708 formed in the polymer substrate, and a plating film grows in the foam cell. As a result, as shown in FIG. 19, a plating film grows in a complicated shape deep inside the polymer substrate, and a continuous plating film 709 can be formed from inside the polymer substrate. Therefore, a plating film having higher adhesion is formed. In addition, as shown in FIG. 19, the foam cell 708 which the electroless plating solution did not reach remains in the polymer substrate as it is. In addition, when the size of the foam cell 708 present in the polymer base material molded in this example was examined by SEM (Scanning Electron Microscope), it was about 10 to 20 μm.

  Also for the polymer member produced in this example, the adhesion evaluation of the metal film was performed in the same high temperature and high humidity environment test as in Example 1. A high temperature test was also conducted under conditions of a temperature of 150 ° C. and a standing time of 500 hours. As a result, the same results as in Example 1 were obtained, and no decrease in the adhesion of the metal film was observed. That is, according to the plating film forming method of this example, the plating process can be performed simultaneously with the injection molding, and not only the process can be simplified, but also a metal film with high adhesion is made of a resin material with high heat resistance. It was found that it can be formed.

  Further, in the polymer member produced in this example, the penetration depth of the metal film into the polymer substrate is about 50 μm, and the metal fine particles (Pd) are deeper than that, specifically, to a depth position of about 100 μm. ) Existed.

  In Examples 1 to 8 described above, the example in which the crystal material is used as the forming material of the polymer base material (polymer molded product) has been described. However, the present invention is not limited to this, and the formation of the polymer base material (polymer molded product) is performed. The same effect can be obtained even when an amorphous material is used as the material.

  In the method for producing a polymer member of the present invention, a plated film continuously grown from the inside of the surface of the polymer substrate can be formed without roughening the surface of the polymer substrate. It is optimal as a method for forming a plating film having excellent adhesion to a material.

  Further, in the method for producing a polymer member of the present invention, when an electroless plating process is performed in an injection molding machine, a smooth metal film having high adhesion can be formed on a resin material having high heat resistance. It is suitable as a method for producing a reflector for an automotive headlight that requires heat resistance.

FIG. 1 is a schematic configuration diagram of a plating apparatus used in the first embodiment. 2 is a schematic cross-sectional view of the polymer substrate produced in Example 1, FIG. 2 (a) is a view when the mount and the lens holder are disassembled, and FIG. 2 (b) is a view showing the mount and the lens holder. It is a figure at the time of uniting. FIG. 3 is a schematic cross-sectional view of a polymer substrate after surface modification of the polymer substrate in the method for producing a polymer member of Example 1. FIG. 4 is a schematic cross-sectional view of the polymer member after a plating film is formed on the surface of the polymer substrate in the method for producing the polymer member of Example 1. FIG. 5 is an SEM image of the vicinity of the surface of the polymer member produced in Example 1. FIG. 6 is a schematic configuration diagram of the plating apparatus used in the second embodiment. FIG. 7 is a schematic configuration diagram of the manufacturing apparatus used in the sixth embodiment. FIG. 8 is a view showing a state when high-pressure carbon dioxide in which a metal complex is dissolved in a molten resin in a plasticizing cylinder is introduced, and FIG. 8 (a) shows a state when the plasticizing and lightening of the molten resin is completed. FIG. 8B is a diagram showing a state when high-pressure carbon dioxide is introduced. FIG. 9 is a view showing a state when the injection molding of the polymer molded product is completed in the method of manufacturing a polymer molded product of Example 6. FIG. 10 is a diagram illustrating a state where the polymer molded product is subjected to electroless plating in the method of manufacturing a polymer molded product of Example 6. FIG. 11 is a diagram schematically showing a cross-sectional structure of a polymer molded product produced in Example 6. FIG. 12 is a flowchart for explaining the procedure of the method of manufacturing the polymer member according to the first embodiment. FIG. 13 is a flowchart for explaining the procedure of the method of manufacturing the polymer member according to the sixth embodiment. FIG. 14 is a diagram schematically showing a cross-sectional structure in the vicinity of the surface of the polymer substrate produced in Example 7. FIG. 15 is a diagram schematically showing a cross-sectional structure in the vicinity of the boundary surface between the polymer base material and the plating film of the polymer member produced in Example 7. FIG. 16 is a view showing the flow of the molten resin in the mold during the injection molding of the polymer substrate of Example 8. FIG. 17 is a view showing the state of the molten resin in the mold when the injection molding of the polymer base material of Example 8 is completed. FIG. 18 is a view showing a state in Example 8 when the resin internal pressure is reduced and fine foam cells are formed inside the resin after injection molding. FIG. 19 is a diagram schematically showing a cross-sectional structure of the polymer member produced in Example 8. FIG. 20 is a flowchart for explaining the procedure of the method of manufacturing the polymer member according to the seventh embodiment. FIG. 21 is a flowchart for explaining the procedure of the method of manufacturing the polymer member according to the eighth embodiment. FIG. 22 is a flowchart for explaining an injection molding procedure in the polymer member manufacturing method according to the eighth embodiment.

Explanation of symbols

1, 1 ', 10 High-pressure vessel 8 Electroless plating solution 9 Inner vessel 21 Liquid carbon dioxide cylinder 20, 33, 34 Syringe pump 100, 200 Plating device 102 Polymer member (mount)
109,600 Metal fine particles 300,602,709 Electroless plating film 500 Manufacturing apparatus 501 Electroless plating apparatus section 502 Surface modification apparatus section 503 Injection molding apparatus section 504 Cavity 505 Skin layer (skin)
506 Core layer 507 Polymer molded product 509 Electroless nickel-phosphorus film 510 Gold plating film 601 Water-soluble substance 708 Foamed cell

Claims (9)

A method for producing a polymer member in which a plating film is formed on a polymer substrate,
  Preparing a polymer substrate impregnated with metal particles and particles of a substance that dissolves in the electroless plating solution inside the surface;
  Contacting the polymer substrate with high pressure carbon dioxide to swell the vicinity of the surface of the polymer substrate;
  A manufacturing method comprising: contacting an electroless plating solution containing high-pressure carbon dioxide with the polymer substrate in a state where the vicinity of the surface of the polymer substrate is swollen to form a plating film on the polymer substrate. It is possible to prepare a polymer base material impregnated with metal particles and particles of a substance that dissolves in the electroless plating solution inside the surface, and a substance that dissolves in the metal particles and electroless plating solution inside the surface in the mold of the injection molding machine The manufacturing method according to claim 1, comprising molding a polymer substrate impregnated with. The method according to claim 1 or 2, wherein the substance that dissolves in the electroless plating solution is a water-soluble substance. A method for producing a polymer member in which a plating film is formed on a polymer substrate,
  Preparing a polymer substrate having metal fine particles and voids inside the surface;
  Contacting the polymer substrate with high pressure carbon dioxide to swell the vicinity of the surface of the polymer substrate;
  A manufacturing method comprising: contacting an electroless plating solution containing high-pressure carbon dioxide with the polymer substrate in a state where the vicinity of the surface of the polymer substrate is swollen to form a plating film on the polymer substrate. Preparing a polymer base material having metal fine particles and voids inside the surface, using an injection molding machine equipped with a mold and a heating cylinder, the high pressure carbon dioxide in which the metal complex containing the metal fine particles is dissolved is used for the heating cylinder. Injecting into the molten resin of the polymer base material, injecting the molten resin into which the high-pressure carbon dioxide in which the metal complex is dissolved is introduced into the mold, and the high pressure in the injected molten resin The method according to claim 4, comprising foaming carbon dioxide to form voids . The said electroless-plating liquid contains alcohol, The manufacturing method as described in any one of Claims 1-5 characterized by the above-mentioned . The manufacturing method according to claim 1, wherein the electroless plating solution contains a surfactant . All of the said high pressure carbon dioxide is the carbon dioxide of the supercritical state which has a pressure of 7.38 Mpa or more and 20 Mpa or less, The manufacturing method as described in any one of Claims 1-7 characterized by the above-mentioned . The polymer member manufactured by the manufacturing method of the polymer member as described in any one of Claims 1-8.

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