JP2009215496A - Method of manufacturing composite material including resin molding - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of permeating and immobilizing a metal complex stably even in a low temperature processing in a batch processing method of a plating pretreatment which permeates the metal complex into a polymer using a high pressure carbon dioxide. <P>SOLUTION: A method of manufacturing a composite material including a resin molding 200 is provided, which method includes: bringing a reduction agent into contact with the resin molding to permeate the reduction agent into the resin molding 200 (S21); and contacting the resin molding 200 with the high pressure carbon dioxide dissolved with the organometal complex to immobilize the organometal complex into the resin molding 200 (S22). <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for producing a composite material including a resin molded body.

  Conventionally, an electroless plating method is known as a method for forming a metal film at low cost on a resin molded body such as a polymer member (polymer molded product). In the electroless plating method, the surface of the polymer member is etched as a pretreatment for electroless plating using an oxidizing agent such as hexavalent chromic acid or permanganic acid in order to ensure the adhesion of the plating film. It is necessary to roughen the surface of the member. However, oxidizing agents such as hexavalent chromic acid and permanganic acid have a large environmental load.

  In addition, polymers immersed in such an etching solution, that is, polymers to which electroless plating can be applied are limited to polymers of some materials such as ABS. This is because ABS contains a butadiene rubber component, and this component can be selectively immersed in an etching solution to form irregularities on the surface of the polymer member. This is because there are few components that are selectively oxidized by such an etchant and it is difficult to form irregularities on the surface. Therefore, polycarbonate and the like, which are polymers other than ABS, are commercially available as plating grades in which ABS and elastomer are mixed to enable electroless plating. However, in such plating-grade polymer materials, it is impossible to avoid deterioration of physical properties such as a decrease in heat resistance compared to the case of using only the main material, and molded products that require heat resistance. It was difficult to use with.

  As an alternative to such a chemical pretreatment method, a surface modification method using high-pressure carbon dioxide such as supercritical carbon dioxide has been proposed (for example, Patent Document 1). In Patent Document 1, in a batch processing (non-continuous processing in a high-pressure vessel) method, a metal complex is dissolved in high-pressure carbon dioxide, and the high-pressure carbon dioxide in which the metal complex is dissolved is brought into contact with a polymer member. As a result, the metal complex penetrates into the surface of the polymer member.

  Patent Document 2 discloses a technique in which a metal complex that has penetrated into the inside of the polymer is thermally reduced so that the metal complex is metalized and fixed inside the polymer, and this metal functions as a catalyst nucleus for plating.

  Furthermore, the present inventors use high pressure carbon dioxide to infiltrate the metal catalyst into the interior of the polymer, and then use an electroless plating solution in which high pressure carbon dioxide is mixed. A method of forming an electroless plating film is disclosed (Patent Document 3). This is a method in which a mixed solution of an electroless plating solution and high-pressure carbon dioxide is infiltrated into the polymer at a low temperature at which no plating reaction occurs, and then the temperature of the polymer is increased to a temperature at which plating reaction is possible. According to the study by the present inventors, the catalyst nucleus formed by thermally reducing the metal complex has penetrated into the polymer in advance, so that the electroless plating reaction grows from the inside of the polymer using this catalyst nucleus, It is considered that a plating film having adhesion strength equal to or higher than that of a conventional etching method can be obtained.

JP 2001-316832 A JP 2007-56287 A Japanese Patent No. 3926835

  As described above, in the conventional method of plating a resin molded body, it is necessary to perform pretreatment with a large environmental load, and the types of polymer materials that can be selected are also limited.

  In addition, when the polymer member surface modification method using high-pressure carbon dioxide such as supercritical fluid of Patent Document 1 is used to infiltrate the polymer member with metal fine particles as a plating catalyst by batch processing, By performing thermal reduction, a polymer member in which metal fine particles serving as a plating catalyst are present on the surface of the polymer member is obtained.

  By the way, the inventors' research has revealed that a fluorine-containing metal complex is effective as a metal complex dissolved in high-pressure carbon dioxide in the pretreatment method using high-pressure carbon dioxide in such a supercritical state. It has become. Since the fluorine-containing metal complex has high solubility in high-pressure carbon dioxide, the complex can be concentrated in a high-pressure vessel, and the permeation treatment time can be shortened by infiltrating the complex at a high concentration. . This will be described in detail below.

  For example, the solubility of acetylacetonato palladium (II) complex, which is a metal complex not containing fluorine, in high-pressure liquid carbon dioxide (temperature 40 ° C., pressure 15 MPa) is several tens mg / L, and the solubility is extremely low. Therefore, it took 30 minutes to 1 hour or more in order to allow the metal complex to penetrate into the polymer at a high concentration. In addition, since this metal complex has high thermal stability, it takes a long time for thermal reduction, and the thermal reduction temperature must be as high as 200 ° C. or higher.

  On the other hand, the hexafluoroacetylacetonato palladium (II) complex, which is a metal complex containing fluorine, has a solubility in the same high-pressure carbon dioxide of several tens of g / L, which is two orders of magnitude higher than that of the aforementioned metal complex. . Therefore, the concentration of the metal complex in the high-pressure vessel can be increased by several to several tens of minutes, and the permeation time can be shortened compared to the case of the metal complex described above.

  However, such fluorine-containing metal complexes have extremely high solubility in high-pressure carbon dioxide, but have a low affinity for polymer members. The metal complex that has penetrated into the polymer returns to the high-pressure carbon dioxide side. Therefore, it is not fixed as expected just by penetrating the inside of the polymer. It is difficult to increase the concentration of the metal complex inside the polymer.

  Therefore, the inventors have made it possible to increase the concentration of the metal complex inside the polymer by conducting a thermal reduction treatment in high-temperature high-pressure carbon dioxide immediately after penetrating the metal complex into the polymer, through independent research. did it. Since the metal complex containing fluorine has low thermal stability, it can be completely thermally decomposed and reduced at a temperature of about 150 ° C.

  However, if the thermal reduction is not performed in the high-pressure vessel used to penetrate the metal complex, the metal complex is difficult to be immobilized in the polymer. First, because the metal complex has a high affinity for carbon dioxide, if the carbon dioxide is exhausted before the reduction treatment, the metal complex that has penetrated into the polymer together with the exhausted carbon dioxide is also discharged. Second, if the metal complex is infiltrated with high-pressure carbon dioxide and then the polymer is taken out from the high-pressure vessel and subjected to thermal or chemical reduction treatment, the treatment is performed. This is because the metal complex has already escaped from the polymer.

  Further, as a result of intensive studies on the plating pretreatment by batch processing using this high-pressure vessel, the present inventors have revealed that the following problems become apparent.

  First, when a plurality of polymer molded bodies are processed in a single high-temperature container, the metal complex may be thermally decomposed before penetrating into the inside of the polymer. There were sometimes bad places and molded products. That is, the quality has varied.

  Second, if the metal complex and carbon dioxide are infiltrated into the polymer at a low temperature and then the temperature in the bath is raised to thermally decompose and reduce the metal complex inside the polymer, the above quality variation is suppressed. However, since the metal complex in the high-pressure vessel completely decomposes including the one that stays excessively without penetrating into the polymer molded body, the expensive metal complex cannot be recovered. Instead of increasing the temperature in the bath, it may be possible to introduce a reducing agent such as alcohol into the high-pressure vessel under high pressure, but in this case as well, the unpermeated excess metal complex cannot be recovered. . In this way, only a small portion of the metal complex charged in the high-pressure vessel penetrates into the polymer, but the conventional metal reduction cannot recover the surplus metal complex and thermally decomposes inside the vessel. Or it will be reduced, so it will be a big loss. Therefore, it became uneconomical and a major obstacle to industrialization.

  Thirdly, the following problems have been clarified when applied to the electroless plating method using high-pressure carbon dioxide in the plating pretreatment using high-pressure carbon dioxide in the supercritical state or the like. That is, in the case of the method in which the metal complex is infiltrated in the high-pressure vessel and then thermally reduced and metallized and immobilized, the metal complex is reduced and immobilized from the surface side of the resin molded body, so that FIG. ), The concentration of the metal fine particles or the metal complex increases as the surface layer of the resin molded body increases. For this reason, when a plating solution mixed with high-pressure carbon dioxide is allowed to penetrate inside the polymer and then subjected to a plating reaction from the inside of the polymer, the catalytic activity of this surface layer becomes high, and the plating is less likely to grow from inside the polymer. Then, as schematically shown in FIG. 4B, although the penetration depth of the plating film becomes shallow depending on the location of the molded product and high adhesion strength is obtained, the value may fluctuate.

  The present invention has been made to solve the above problems, and a first object of the present invention is to provide a low temperature treatment in a batch processing method of plating pretreatment in which a metal complex is infiltrated into a polymer using high-pressure carbon dioxide. It is also intended to provide a method for stably penetrating and immobilizing a metal complex into a polymer even in the above treatment, and to provide a pretreatment method capable of recovering excess metal complex from the inside of a high-pressure vessel. A second object of the present invention is to provide a technique for improving and stabilizing the adhesion strength more particularly in an electroless plating method in which a plating reaction is performed inside a polymer using high-pressure carbon dioxide.

  According to a first aspect of the present invention, there is provided a method for producing a composite material including a resin molded body, wherein a reducing agent is brought into contact with the resin molded body, and the reducing agent is permeated into the resin molded body. The resin molded body infiltrated with the reducing agent is contacted with high-pressure carbon dioxide in which the organometallic complex is dissolved, and the organometallic complex is immobilized in the resin molded body by the reducing agent. The manufacturing method of the composite material containing the resin molding to make is provided.

  According to this 1st aspect, the organometallic complex which osmose | permeates the resin molding body is fix | immobilized in the resin molding body by the reductive reaction with the reducing agent which osmose | permeated the resin molding body previously. Therefore, in order to fix the organometallic complex in the resin molded body, the temperature does not need to be higher than the thermal reduction temperature of the organometallic complex. That is, the high-pressure carbon dioxide in which the organometallic complex is dissolved may be brought into contact with the resin molded body in a temperature atmosphere lower than the thermal reduction temperature of the organometallic complex. On the other hand, when an organometallic complex is immobilized by a thermal reduction reaction, the resin molded body must be heated to a temperature at which it becomes a thermal reduction reaction, or cooled to room temperature, thereby pretreatment process. Throughput was limited. Also, for example, in resin molded bodies molded by injection, there is a difference in residual stress between the skin layer and the inside during molding, and when this is heated and cooled, it foams, the surface cracks, Internal cracks may occur. In the first aspect, these problems can be solved.

  In the first embodiment, the reducing agent may be any material having, for example, an OH group, and examples of such a reducing agent include alcohol and phenol. Moreover, a reducing agent may be dissolved in a solvent and may contact a resin molding. Such a solvent may be carbon dioxide, water or alcohol. When alcohol is used as a solvent, the reduction process is a wet process. And what is necessary is just to make it contact in the atmosphere of a high pressure carbon dioxide, or contact by the ultrasonic cleaning, for example, making the solvent containing a reducing agent contact the said resin molding.

  In addition, in the first aspect, the resin molded body infiltrated with the reducing agent is brought into contact with the high-pressure carbon dioxide in which the organometallic complex is dissolved after the reducing agent is removed from the surface layer. Also good. As a result, the reducing agent not only penetrates into the resin molded body but also penetrates in a state where it is removed from the surface layer of the resin molded body, so that the organometallic complex is deep inside the surface layer of the resin molded body. By the way, it is fixed. Therefore, the metal complex can be stably penetrated into the polymer and immobilized even at low temperature treatment.

  The surface layer means, for example, within a range of a depth of 50 nm or less from the surface of the resin molded body. In this range, the organometallic complex is contacted without removing the reducing agent, and further electroless plating is performed. As a result, a plating film is formed. This plating film has low overall adhesion to the resin molded body and a large variation in the degree of adhesion for each part.

  Further, in order to be said to have been removed from the surface layer of the molded resin body, at least the organometallic complex penetrating the surface layer may be reduced, but preferably, the number of remaining portions (concentration) of the surface layer is deeper than the surface layer. Organometallic that has penetrated the surface layer to such an extent that it becomes smaller than (concentration) or the number (concentration) of the organometallic complex at a given unit depth reaches the maximum (peak) at a site deeper than the surface layer. It is desirable to reduce the complex.

  That is, by reducing the reducing agent from the surface layer of the resin molding, the metal complex is selectively reduced and immobilized only within the resin molding. The metal complex is difficult to be reduced because the reducing agent concentration in the surface layer of the resin molding is low, but the metal complex is likely to be reduced inside the reducing agent concentration is high. As a result, the dispersion concentration of the internal metal complex is higher than the surface layer of the resin. Therefore, when a plating reaction is performed inside the resin by an electroless plating method using high-pressure carbon dioxide as will be described later, the plating film hardly grows on the surface layer of the resin, and the plating film easily grows reliably from the inside. For this reason, the adhesion and stability of the plating are enhanced.

  In addition, the process of removing the reducing agent from the surface layer of the resin molded body may be performed by, for example, washing the resin molded body infiltrated with the reducing agent with water within a predetermined time or supplying air to the resin molded body infiltrated with the reducing agent. What is necessary is just to spray within predetermined time. Thereby, a reducing agent can be removed from the surface layer of a resin molding. Part of the reducing agent that has permeated the resin molding can be removed. In particular, when the reducing agent is alcohol or the like, the alcohol or the like is easily volatilized, so that the reducing agent can be removed from the surface layer of the resin molded body by simply leaving it in the air within a predetermined time.

  In the first embodiment, a plating film may be further formed on the resin molded body on which the organometallic complex is fixed by an electroless plating method containing high-pressure carbon dioxide. In this case, plating can be grown from the organometallic complex fixed deep inside the surface layer of the resin molded body, and a plating film that adheres to the resin molded body with a high degree of adhesion can be formed. In addition, since there is no or little organometallic complex in the surface layer of the resin molding, the plating film does not grow from the surface layer, and the adhesion of the plating film is stabilized at a high value.

  On the other hand, for example, when a plating film is simply formed by electroless plating containing high-pressure carbon dioxide on a resin molded body provided with an organometallic complex, the temperature of the resin molded body As the temperature rises from the surface side with a temperature gradient from the inside to the inside, and since the organometallic complex is applied to the resin molding from the inside to the surface side, the plating film has a high concentration on the surface layer. Thus, the adhesion degree of the plating film to the resin molded body could not be increased. Also, in the surface layer, a place where the plating film grows from the surface side part and a part where the plating film grows from the inside part are mixed, and the adhesion degree of the plating film is low Moreover, this degree of adhesion becomes unstable.

  In addition, the first aspect further includes the step of fixing the resin molded body at a temperature higher than the thermal reduction temperature of the organometallic complex after immobilizing the organometallic complex and before forming the plating film. You may heat. After immobilizing the organometallic complex in a deep part inside the surface layer of the resin molded body in this way, when heated to a temperature higher than the thermal reduction temperature of the organometallic complex, the organometallic complex moves to the surface side, and the resin molded body It is possible to increase the concentration of the organometallic complex in a deep part inside the surface layer of the layer. Therefore, the amount of catalyst nuclei in the deep part inside the surface layer of the resin molded body is increased compared with the case of the immediately preceding paragraph where pretreatment by heating (annealing treatment) is not performed, and accordingly, the degree of adhesion of the plating film to the resin molded body. Can be further increased. In addition, since the organometallic complex is present at a high concentration at a predetermined depth, the plating film is stably grown from the predetermined depth, and the stability of the adhesion of the plating film is further enhanced. .

  Moreover, in this 1st aspect, the said organometallic complex is fixed to the said resin molding by being accommodated in a high-pressure container with the said resin molding, and the said resin molding is made of the said organometallic complex. The treatment for heating to a temperature higher than the thermal reduction temperature may be performed after the organometallic complex is recovered from the high-pressure vessel. As a result, the organometallic complex does not undergo a thermal reduction reaction when coming into contact with the resin molding, and can be separated and recovered from the high-pressure carbon dioxide after the contact treatment. The recovered organometallic complex can be reused.

  In the first aspect, the organometallic complex may contain fluorine. Since the organometallic complex containing fluorine dissolves well in carbon dioxide, it can be dissolved in high-pressure carbon dioxide at a high concentration and brought into contact with the resin molding. In addition, the organometallic complex containing fluorine has the property that it is difficult to enter the resin molding, but since the reducing agent has been previously infiltrated into the resin molding, a high concentration of the organometallic complex penetrates into the resin molding. Thus, the organometallic complex can be efficiently immobilized in the resin molded body.

  In the first aspect, the organometallic complex may contain at least one metal element of Pd, Pt, Ni, Cu, and Ag, which are metal elements that function as a plating catalyst. Thereby, the catalyst for plating can be fixed in the deep part inside the surface layer of the resin molding.

  In the first aspect, the high-pressure carbon dioxide may be in a supercritical state.

  By the way, although the kind of reducing agent which can be used for this invention is arbitrary, reducing agents, such as a dimethylamine borane, sodium borohydride, sodium hypophosphite, can be used, for example. In the case of such a solid reducing agent, a reducing agent can be infiltrated into the resin by preparing a solution dissolved in a solvent such as water or alcohol and immersing the thermoplastic resin in the solution. In order to increase the permeability to the thermoplastic resin, ultrasonic waves may be applied to the solution, the solution may be heated, or the pH may be adjusted depending on the type of the reducing agent. For example, when sodium borohydride is used, the solution is preferably adjusted to be alkaline, and when sodium hypophosphite is used, it is desirable to adjust from neutral to acidic. When an aqueous solution is used, a solvent having a low surface tension such as ethanol may be mixed or an additive such as sodium lauryl sulfate may be dissolved in order to reduce the surface tension and increase the penetrating power.

  Further, alcohol having a hydroxyl group having a reducing action, polyalkyl glycol, phenol and the like can be used as a reducing agent. In particular, ethanol is suitable because it has a low surface tension and easily penetrates into the resin. Although the kind of alcohol is arbitrary, methyl alcohol, ethyl alcohol, isopropyl alcohol, butanol, ethylene glycol, etc. can be used. By using a high molecular weight polyalkyl glycol such as polyethylene glycol, it is possible to prevent the reducing agent from being completely removed from the inside of the resin and the effect disappearing. Furthermore, these reducing agents may be used in combination of two or more.

  Moreover, in this invention, the permeability | transmittance of a reducing agent can be improved more by mixing the solution which these reducing agents and the reducing agent melt | dissolved with the high pressure fluid. In particular, by using high-pressure carbon dioxide or supercritical carbon dioxide (hereinafter referred to as supercritical carbon dioxide), the resin surface can be swollen and the reducing agent can penetrate deeply into the resin.

  In addition, the resin material that can be used in the present invention is not particularly limited, and a thermoplastic resin, a thermosetting resin, and a photocurable resin can be used. In the case of a thermoplastic resin, the kind is usually arbitrary regardless of whether it is amorphous or crystalline. Specifically, for example, polyolefins such as low density polyethylene, high density polyethylene, polypropylene, poly-4-methylpentene-1, polyvinyl chloride, polyvinyl alcohol, polyacrylonitrile and other polyvinyls, polyoxymethylene, polyethylene oxide, etc. Other polymer materials such as polyether, polyester, polyamide, polyimide, polymethyl methacrylate, polysulfone, polycarbonate, and polylactic acid can be used. Furthermore, aromatic polyesters such as polyethylene terephthalate, aromatic amides such as polyterephthalamide, and fluorine-based polymers such as polytetrafluoroethylene can be used. In the case of a thermosetting resin, epoxy resin, phenol resin, polyimide, polyurethane, silicone resin, or the like can be used. In the case of a photocurable resin, a photosensitive epoxy resin, a photosensitive acrylic resin, a photosensitive polyimide, or the like can be used. You may use for these resin materials what contained fillers, such as glass fiber, carbon fiber, an inorganic compound, and a ceramic.

  In addition, as the organometallic complex that can be used in the present embodiment, at least one of the metal elements Pd, Pt, Ni, Cu, and Ag that has a certain degree of solubility in high-pressure carbon dioxide and serves as a plating catalyst. The kind is preferably a contained material. For example, bis (cyclopentadienyl) nickel, bis (acetylacetonato) palladium (II), dimethyl (cyclooctadienyl) platinum (II), hexafluoroacetylacetonatopalladium (II), hexafluoroacetylacetonatohydrate Copper (II), hexafluoroacetylacetonatoplatinum (II), hexafluoroacetylacetonato (trimethylphosphine) silver (I), dimethyl (heptafluorooctaneconate) silver (AgFOD), or the like can be used. In particular, a metal complex having fluorine as a ligand is suitable because it is easily compatible with high-pressure carbon dioxide.

  In the present invention, first, in a batch treatment method of plating pretreatment in which a metal complex is infiltrated into a polymer using high-pressure carbon dioxide, the metal complex is stably infiltrated into and fixed to the polymer even in a low-temperature treatment. And surplus metal complex can be recovered from inside the high-pressure vessel. In the present invention, secondly, the adhesion strength of the plating film can be further improved and stabilized.

  Hereinafter, although the Example of the manufacturing method of the composite material containing the resin molding of this invention is described concretely, this invention is not limited to a following example.

  In this example, in the plating pretreatment, a predetermined high-pressure apparatus was used to dissolve the solvent containing the reducing agent and the organometallic complex in the high-pressure fluid and bring them into contact with the resin material. In this example, carbon dioxide was used as the high-pressure fluid. First, the high-pressure apparatus used in this example will be described.

  FIG. 1 is a schematic diagram illustrating a high-pressure apparatus 100 for performing plating pretreatment and electroless plating to which the present embodiment is applied. As shown in FIG. 1, the high-pressure apparatus 100 mainly includes a first high-pressure vessel 6 that contains a resin material (resin molded body) 200 and a liquid carbon dioxide cylinder that contains carbon dioxide supplied to the first high-pressure vessel 6. 1, a syringe pump 3 that pressurizes carbon dioxide, a second high-pressure vessel (high-pressure vessel) 13 that can be temperature-controlled by a cartridge heater (not shown), and that contains an organometallic complex, and an organometallic complex dissolved in high-pressure carbon dioxide And a separation / recovery machine 9 for separating and recovering the liquid, and a recovery tank 11 for storing the recovered organometallic complex. Moreover, between each component of the high pressure apparatus 100, as shown in FIG. 1, valves 2, 4, 5, 8, 10, 12, and 14 for controlling the pressure and flow of high pressure carbon dioxide, and a pressure gauge 15 and 16 are appropriately installed at predetermined positions.

  The first high-pressure vessel 6 can be cooled by cooling water that flows in a cooling circuit (not shown). The first high-pressure vessel 6 can be supplied with a mixed medium of a solvent containing a reducing agent and high-pressure carbon dioxide, and a mixed medium of an organometallic complex and high-pressure carbon dioxide. The first high pressure vessel 6 can be filled with an electroless plating solution.

  In this example, a mixed solvent of ethylene glycol and ethanol is used as a solvent containing a reducing agent, and the resin material 200 is polyamide 6 (PA6) mixed with 10% glass fiber, 70 mm long, 15 mm wide, and 1 mm thick. A substrate was used, and hexafluoroacetylacetonato palladium (II) containing a plating catalyst Pd was used as the organometallic complex. Further, as a plating film, a nickel phosphorous film was formed by electroless plating using high-pressure carbon dioxide, and a nickel film was further laminated thereon by electrolytic plating.

  In this example, a plating film was formed on the surface of the resin material 200 by the procedure shown in FIG.

  First, a mixed solution of 100 ml of ethanol and 100 ml of ethylene glycol was prepared, and this mixed solution was charged together with the resin material 200 into the first high pressure vessel 6 having an internal volume of 300 ml. The first high-pressure vessel 6 was temperature-controlled at 80 ° C. in a sealed state. Next, the liquid carbon dioxide supplied from the liquid carbon dioxide cylinder 1 was pressurized with a syringe pump (260D manufactured by ISCO), and the pressure gauge 15 was pressurized to 15 MPa to obtain supercritical carbon dioxide. Furthermore, the manual needle valve 5 was opened via the check valve 4, the inside of the first high-pressure vessel 6 was increased to 15 MPa, and supercritical carbon dioxide was filled. After the pressure increase, the manual needle valve 5 was closed. While maintaining the pressure inside the first high-pressure vessel 6 for 60 minutes, supercritical carbon dioxide was brought into contact with the resin material 200, and ethanol and ethylene glycol were permeated into the resin material 200 (step S21 in FIG. 2).

  In this embodiment, the step of applying the solvent containing the reducing agent to the resin material 200 is performed under supercritical conditions. However, the temperature and pressure of the first high-pressure vessel 6 in this step are not limited thereto. However, since the sealing of the first high-pressure vessel 6 becomes difficult, the temperature and pressure are preferably 200 ° C. or lower and 30 MPa or lower, respectively. In the present embodiment, stirring is not performed inside the first high-pressure vessel 6, but stirring may be performed using the stirrer 17 or the like. In the present embodiment, the pressure holding time of the first high-pressure vessel 6 is set to 60 minutes, but it is sufficient that the solvent containing the reducing agent penetrates into the resin material 200. The optimum time varies depending on the type, the temperature in the first high-pressure vessel 6 and the pressure.

  Next, the manual needle valve 7 was opened, the back pressure valve 8 was further opened, and the first high-pressure vessel 6 was opened to the atmosphere. Next, the resin material 200 and the mixed solution of ethanol and ethylene glycol are taken out from the first high-pressure vessel 6, the resin material 200 is washed with water, and the normal temperature is reached in the atmosphere until the ethanol and ethylene glycol on the surface of the resin material 200 evaporate. And dried. Thereby, among the reducing agents that have penetrated into the resin material 200, the reducing agent on the surface layer (outermost surface portion) of the resin material 200 can be removed from the resin material 200.

  Next, the dried resin material 200 was charged into the first high-pressure vessel 6 and sealed, and 100 mg of the organometallic complex was charged into the second high-pressure vessel 13 having an internal volume of 100 ml and sealed, and the temperature was adjusted to 50 ° C. . Next, the liquid carbon dioxide supplied from the liquid carbon dioxide cylinder 1 was pressurized with the syringe pump 3, and the pressure was increased so that the pressure gauge 15 became 15 MPa, thereby obtaining supercritical carbon dioxide. Next, the manual needle valve 14 was opened via the check valve 4, the inside of the second high-pressure vessel 13 was pressurized to 15 MPa, and the organometallic complex was dissolved in supercritical carbon dioxide. Next, the manual needle valve 15 was opened, supercritical carbon dioxide containing an organometallic complex was brought into contact with the resin material 200 for 45 minutes, and the organometallic complex was infiltrated into the resin material 200 (step S22 in FIG. 2).

  In the first high-pressure vessel 6, it is desirable that the high-pressure carbon dioxide and the organometallic complex are made into a uniform phase using a stirrer 17 or the like. Therefore, in this example, the mixed solvent in the first high-pressure vessel 6 was constantly stirred by the stirrer 17.

  Moreover, it is desirable that the temperature and pressure of the first high-pressure vessel 6 satisfy the supercritical conditions and are temperatures at which the organometallic complex is not thermally reduced. Thereby, in the supercritical state, the surface tension decreases, and the organometallic complex easily penetrates into the resin material 200. In addition, since the organometallic complex is in a temperature atmosphere that is not thermally reduced, the organometallic complex that does not penetrate into the resin material 200 and remains in the first high-pressure vessel 6 is not decomposed, and can be recovered and reused thereafter. It becomes. Further, the concentration of the organometallic complex and the reduced metal fine particles can be prevented only from increasing near the surface of the resin material 200 and can penetrate deeper than the conventional one. Improvement in adhesion can be expected. When carbon dioxide is used, the temperature and pressure, which are supercritical conditions, are 31 ° C. and 7.1 MPa or more, respectively. In order to ensure the airtightness of the first high-pressure vessel 6 by a seal (not shown), it is desirable that each be 200 ° C. and 30 MPa or less.

  In the present invention, the internal temperature of the first high-pressure vessel 6 in which the metal complex is dissolved in high-pressure carbon dioxide and brought into contact with the resin material 200 is determined by measuring the thermal decomposition temperature of the metal complex in advance with a differential scanning calorimeter (DSC). It is desirable to control the temperature to be 10 ° C. or more lower than the thermal decomposition start temperature of the metal complex in the air or nitrogen atmosphere. Even when the heat resistance temperature of the metal complex is high, it is desirable to perform the high-pressure treatment in a temperature atmosphere in which the reducing agent that has previously permeated the resin material 200 does not change, sublimate, boil, or the like. In this example, hexafluoroacetylacetonato palladium (II) is used as the organometallic complex, and the thermal decomposition start temperature in the nitrogen atmosphere of this complex is about 73 ° C. or higher, so the treatment temperature is 50 ° C. of 63 ° C. or lower. there were.

  In addition, the time during which the organometallic complex is dissolved in supercritical carbon dioxide and is in contact with the resin material 200 may be any time as long as the organometallic complex penetrates into the resin material 200. The optimum time varies depending on the temperature and pressure in the first high-pressure vessel 6.

  After infiltrating the organometallic complex into the resin material 200, the manual needle valve 7 was opened, the back pressure valve 8 was opened, the first high-pressure vessel 6 was opened to the atmosphere through the separation and recovery device 9, and the resin material 200 was taken out. In the recovery tank 11, the organometallic complex separated from carbon dioxide was recovered. The recovered amount of the metal complex is shown in Table 1 described later.

  By the way, in the plating pretreatment method of the resin material 200 of the present invention, when the organometallic complex is infiltrated into the resin material 200, the metal that becomes the catalyst core for plating by the solvent containing the reducing agent in the resin material 200. Reduced to fine particles. For this reason, in the present invention, after the treatment with high-pressure carbon dioxide, a reduction treatment or a heat treatment is preferably performed in order to further reduce the metal complex in the resin material 200 and segregate inside the surface. In fact, the present inventors have confirmed that the adhesion of the plating film is further improved when the resin material 200 taken out from the first high-pressure vessel 6 is heated after infiltrating the organometallic complex into the resin material 200. .

  The cause of the improvement in adhesion by this heat treatment is not clear, but is considered to be the following mechanism. In the case of plating in which an electroless plating film is grown from the inside of the resin 200 such as a thermoplastic resin using high-pressure carbon dioxide, the depth at which the plating penetrates into the resin 200 is suitably 50 to 200 nm or less, more preferably 50 It has been found to be about ˜100 nm. When the penetration depth of plating exceeds that, it is considered that the swelling and stress on the outermost surface of the resin 200 increase and the strength of the resin 200 deteriorates. Therefore, the depth of penetration of the metal complex and the metal fine particles is appropriately 50 to 200 nm from the surface of the resin 200. However, when the permeation treatment is actually performed, the metal complex and the metal fine particles may permeate to a depth of 1 μm or more.

  Then, by performing the heat treatment in such a situation, the metal fine particles that penetrate deeply into the resin 200 and are not compatible with the resin 200 are concentrated in an appropriate depth region in the vicinity of the surface of the resin 200, which is inside the resin 200. This is thought to contribute to improving the plating reactivity. Alternatively, it is considered that a metal complex that does not react with the reducing agent and is not exhausted by the surface when the high-pressure carbon dioxide is exhausted under reduced pressure and penetrates deeply into the resin 200 remains. In any case, it is considered that the metal fine particles concentrate in an appropriate depth region in the vicinity of the surface because these metal complexes try to bleed out to the surface by the thermal reduction treatment.

  For this reason, in this example, after the organometallic complex was infiltrated into the resin material 200, the thermoplastic resin 200 infiltrated with the catalyst was then heat-treated in an air atmosphere at a temperature of 150 ° C. for 1 hour. As described above, the plating pretreatment of the resin material 200 in this example was performed.

  Next, an electroless plating film was formed on the resin material 200 that had been subjected to the plating pretreatment (step S23 in FIG. 2). 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 for the electroless plating solution. In this example, water and alcohol were mixed in the electroless plating solution. The type of alcohol is arbitrary, and methanol, ethanol, n-propanol, isopropanol, butanol, heptanol, ethylene glycol, and the like can be used. In this example, ethanol was used.

  In the plating film forming step, first, the resin material 200 and the Ni—P electroless plating solution were charged into the first high-pressure vessel 6 of FIG. 1 and sealed. The temperature of the first high-pressure vessel 6 and the Ni—P electroless plating solution was adjusted to 50 ° C. which is lower than the plating reaction temperature (70 ° C. to 85 ° C.). Under this condition, since the resin material 200 is in contact with an electroless plating solution at a temperature lower than the plating reaction temperature (a temperature at which no plating reaction occurs), the plating film does not grow on the surface of the resin material 200.

  Next, high-pressure carbon dioxide was introduced into the first high-pressure vessel 6 that was temperature-controlled so that no plating reaction occurred. In this example, supercritical carbon dioxide was used as high-pressure carbon dioxide. Specifically, the liquid carbon dioxide supplied from the liquid carbon dioxide cylinder 1 was pressurized with a syringe pump (260D manufactured by ISCO), and the pressure gauge 15 was pressurized to 15 MPa to obtain supercritical carbon dioxide. Further, the manual needle valve 5 was opened through the check valve 4, the inside of the first high-pressure vessel 6 was pressurized to 15 MPa, the supercritical carbon dioxide was filled, and the supercritical carbon dioxide was brought into contact with the resin material 200.

  At this time, the surface of the resin material 200 swells due to the introduced supercritical carbon dioxide. In addition, since the plating solution mixed with supercritical carbon dioxide has a low surface tension, the electroless plating solution efficiently penetrates into the resin material 200 together with the supercritical carbon dioxide. As a result, the electroless plating solution reaches the metal fine particles existing inside the resin material 200. In this example, since the electroless plating solution contains alcohol, the surface tension of the electroless plating solution is further lowered, and the electroless plating solution is more easily penetrated into the resin material 200. . In this example, stirring was not performed after the introduction of supercritical carbon dioxide, but stirring may be performed with a stirrer 17 or the like in order to increase the compatibility between the supercritical carbon dioxide and the plating solution.

  Next, the temperature of the first high-pressure vessel 6 is raised to 85 ° C. Thereby, a plating reaction occurs in the first high-pressure vessel 6. An electroless plating reaction occurred on the surface of the resin material 200, and a plating film was formed. At this time, in the plating film forming method of this example, since the electroless plating solution penetrates to the metal fine particles existing inside the resin material 200 as described above, not only the surface of the resin material 200 but also the inside thereof. The plating film grew using the metal fine particles present in the catalyst as catalyst nuclei. That is, in the plating film forming method of this example, the plating film grows also in the free volume inside the resin material 200, and the plating film is formed with high adhesion in a state of biting into the resin material 200. .

  After the completion of plating, the manual needle valve 7 was opened, the back pressure valve 8 was further opened, and the carbon dioxide in the first high-pressure vessel 6 was exhausted. Next, the first high-pressure vessel 6 was opened, and the resin material 200 was taken out from the first high-pressure vessel 6. Next, in order to degas the carbon dioxide and the electroless plating solution from the inside of the resin material 200 taken out from the first high-pressure vessel 6, the resin material 200 was dried for a while.

  Next, electroless plating and electrolytic plating were performed on the resin material 200 at normal pressure (step S24 in FIG. 2). First, the oxidized plating film surface of the resin material 200 was activated with hydrochloric acid. Thereafter, electroless plating was performed at normal pressure using a conventional electroless nickel-phosphorous solution in the atmosphere, and a 1 μm thick plating film was laminated. Furthermore, a nickel film having a thickness of 40 μm was laminated in the atmosphere by a conventional electrolytic plating method using a plating film formed by an electroless plating method as an electrode. By the above method, the resin material 200 in which the entire surface was covered with the metal film was obtained.

Comparative Example 1
In this comparative example, a plating film was formed on the surface of the resin material 200 by the procedure shown in FIG. That is, in this comparative example, the step of bringing the solvent containing the reducing agent into contact with the resin material 200 and allowing it to permeate (step S21 in FIG. 2) was not performed. Otherwise, a plating film was formed on the surface of the resin material 200 in the same manner as in Example 1.

  However, almost no plating film was formed on the resin material 200 in the step of performing electroless plating under high-pressure carbon dioxide (step S32 in FIG. 3). This is presumably because the metal complex has low compatibility with the resin and once penetrated into the resin, but was discharged at the same time as the high-pressure carbon dioxide was exhausted, and hardly remained in the resin 200.

Comparative Example 2
In this comparative example, the temperature of the first high-pressure vessel 6 was made 150 ° C. when supercritical carbon dioxide in which an organometallic complex containing a plating catalyst was dissolved was brought into contact with and infiltrated with the resin material 200. Other than that, a plating film was formed on the surface of the resin material 200 by the same treatment as in Comparative Example 1. As a result, a resin material 200 whose entire surface was covered with a metal film was obtained.

  In the present example, a plating film was formed on the resin material 200 by the procedure shown in FIG. However, after the supercritical carbon dioxide in which the organometallic complex containing the plating catalyst is dissolved is brought into contact with the resin material 200 and infiltrated (step S22 in FIG. 2), heat treatment is performed as in the first embodiment. Without drying, it was dried at room temperature for 1 hour in the air. Thereafter, a plating film was formed (steps S23 to S24 in FIG. 2). As a result, a resin material 200 whose entire surface was covered with a metal film was obtained.

  In the present example, a plating film was formed on the resin material 200 by the procedure shown in FIG. However, the step of bringing the solvent containing the reducing agent into contact with the resin material and allowing the solvent to penetrate (step S21 in FIG. 2) was performed in the atmosphere without using the high-pressure apparatus shown in FIG. Specifically, the resin material 200 is put in a sealed container (not shown) containing a mixed solution of 100 ml of ethanol and 100 ml of ethylene glycol, subjected to ultrasonic waves at 80 ° C. for 60 minutes under normal pressure, and then taken out to remove ethanol on the surface. Dry until the ethylene glycol has evaporated. Other than that, the plating film was formed in the resin material 200 like Example 1 (process S22-S24 of FIG. 2). As a result, a resin material 200 whose entire surface was covered with a metal film was obtained.

  In this example, ultrasonic waves were applied for 60 minutes at 80 ° C. under normal pressure. However, the reducing agent only has to penetrate into the resin material 200, and the pressure, temperature, time, presence / absence of ultrasonic waves, etc. It is not limited.

  In this example, a plating film was formed on the surface of the resin material by the same method as in Example 3. However, instead of a mixed solution of 100 ml of ethanol and 100 ml of ethylene glycol, a solution in which 500 mg of sodium hypophosphite was dissolved in 100 ml of ethanol and 100 ml of water was used. As a result, a resin material 200 whose entire surface was covered with a metal film was obtained.

  In this example, a plating film was formed on the surface of the resin material 200 by the procedure shown in FIG. However, instead of a mixed solution of 100 ml of ethanol and 100 ml of ethylene glycol, a mixed solution of 90 ml of 2-methoxyethanol, 90 ml of water and 20 ml of hypophosphorous acid was used. Other than that was carried out similarly to Example 3, and obtained the resin material 200 with which the whole surface was covered with the metal film.

  In this example, a plating film was formed on the resin material 200 by the procedure shown in FIG. However, ethanol was used as the reducing agent in the step of bringing the solvent containing the reducing agent into contact with the resin material 200 and allowing it to penetrate (step S21 in FIG. 2). And 10 ml was put into the 2nd high pressure vessel 2 temperature-controlled at 80 degreeC, the manual needle valve 14 was opened with the manual needle valve 5 closed without opening, and it was set as the gas state which mixed supercritical carbon dioxide and ethanol. Thereafter, the manual needle valve 12 was opened, and the mixed gas was put into the first high-pressure vessel 6 containing the resin material 200 and brought into contact with the resin material 200. Other than that, the plating film was formed in the resin material 200 like Example 1 (process S22-S24 of FIG. 2). As a result, a resin material 200 whose entire surface was covered with a metal film was obtained.

  The quality of the plating films of Examples 1 to 6 and Comparative Examples 1 and 2 was evaluated. As a quality evaluation item, an environmental test and an adhesion evaluation were performed. The conditions of the environmental test were 10 sheets each for 100 hours at a temperature of 80 ° C. and a humidity of 80%. Further, the adhesion strength was evaluated by measuring the tensile strength of 10 sheets each using a tensile testing machine (AGS-J 100N manufactured by Shimadzu Corporation) (JIS 8630). In addition to these results, Table 1 shows the appearance evaluation of the plating film and the amount of the recovered organometallic complex. The tensile strength indicates the measured minimum, maximum, and average values of 10 sheets. In addition, the target value of the tensile strength of the plating using the ABS resin using the conventional etching method is 10 N / cm or more.

  From Table 1, it was found that the plating films formed in Examples 1 to 6 have sufficient adhesion without any problem in actual use. On the other hand, in Comparative Example 1 in which the step of allowing the solvent containing the reducing agent to come into contact with the resin material 200 (step S21 in FIG. 2) was not performed, the plating film was not successfully formed. Then, it can be seen that the organometallic complex is reduced and fixed in the resin material 200 to the metal fine particles serving as the catalyst core for plating by the reducing agent permeated into the resin material 200.

  Moreover, compared with the comparative example 2 which is a conventional method, the fluctuation | variation of tensile strength is smaller in Examples 1-6, and the average value is also high. Furthermore, in Comparative Example 2, the organometallic complex could not be recovered at all, but in Examples 1 to 6, the organometallic complex could be recovered.

  In Comparative Example 2, since the organometallic complex is infiltrated and fixed in the resin material 200 in the first high-pressure vessel 6 by thermal reduction, as shown in FIG. The concentration of the metal fine particles or the metal complex 51 is higher at the outermost surface of 200. For this reason, a plating solution mixed with high-pressure carbon dioxide is permeated into the resin material 200, and then the plating reaction is performed from the inside of the resin material 200. In this case, as shown in FIG. 4 (B), it is considered that the catalytic activity on the outermost surface is high, and the plating growth is difficult from the inside of the resin material 200. In FIG. 4, 51 is a metal fine particle or metal complex, and 52 is a plating film.

  On the other hand, in the case of Examples 1 to 6 of the present invention, the organometallic complex 51 is permeated into the resin material 200 in the first high-pressure vessel 6 at a temperature at which the organometallic complex 51 is not thermally reduced. As shown in FIG. 5 (B), the metal fine particles are deeper away from the surface than the conventional method because they are reduced and metalized and fixed by the reducing agent 61 previously permeated. Alternatively, the concentration of the metal complex 51 becomes high, and therefore, when a plating solution mixed with high-pressure carbon dioxide is permeated into the resin material 200 and then subjected to a plating reaction from the inside of the resin material 200, as shown in FIG. In addition, it is considered that the plating film 52 grows from the inside of the resin material 200 as compared with the conventional method, so that the adhesion strength is improved and the variation is reduced.

  Further, from Table 1, after the supercritical carbon dioxide in which the organometallic complex containing the plating catalyst is dissolved is brought into contact with the resin material 200 and infiltrated, 150 ° C. is performed in the atmosphere in Example 1. The thermoplastic resin infiltrated with the catalyst was subjected to heat treatment for 1 hour at a temperature of 5 ° C. On the other hand, in Example 2, the heat treatment was not performed, and the thermoplastic resin was dried in the atmosphere at room temperature for 1 hour. It can be seen that the adhesion is higher. From this, after the supercritical carbon dioxide in which the organometallic complex containing the catalyst for plating is dissolved is brought into contact with the resin material 200 and infiltrated, an additional reduction treatment (thermal reduction in Example 1) is performed. When it does, it turns out that there exists an effect of an adhesive force improvement.

  FIG. 6 is a distribution diagram qualitatively showing the concentration distribution of the metal fine particles in the resin material 200. FIG. 6A shows the concentration distribution of the metal fine particles in Comparative Example 2, and the concentration distribution of the metal fine particles is the maximum in the surface layer. In this case, the plating solution grows on the surface layer with high density and activated metal fine particles as catalyst nuclei, and a plating film as shown in FIG. 4B is formed. On the other hand, FIG. 6B shows the concentration distribution of the metal fine particles when the metal complex is added after removing the reducing agent from the surface layer, and the concentration distribution of the metal fine particles is maximized at a site deeper than the surface layer. ing. In this case, the plating solution penetrates from the surface layer and grows from the metal fine particles, and a plating film as shown in FIG. 5C is formed.

  FIG. 6C shows the concentration distribution of the metal fine particles when the metal complex is added after removing the reducing agent from the surface layer and further heat-treated, and is deeper than the surface layer as in FIG. 6B. The concentration distribution of the metal fine particles is maximized at the site. In addition, as compared with FIG. 6B, the metal fine particles in the deep portion are reduced, and the metal fine particles are increased in the depth portion where the maximum concentration is reached. For this reason, the plating film in FIG. 6C grows from more metal fine particles present at an appropriate depth than in the case of FIG. 6B, and the adhesion of the plating film increases. It will be.

  In the method for producing a composite material including the resin molded body of the present invention, a plating film having high adhesion and stable in the high adhesion can be formed on the resin molded body. Therefore, when a plating film using high-pressure carbon dioxide is formed by batch processing, it can be suitably used for production stability, improved plating quality, lower running costs, and the like.

FIG. 1 shows a schematic configuration of a high-pressure apparatus used in this embodiment. FIG. 2 shows a flowchart up to the formation of the plating film in the embodiment. FIG. 3 shows a flowchart up to the formation of the plating film in the comparative example. FIG. 4 shows the penetration state of the metal fine particles and the formation state of the plating film in the comparative example. FIG. 5 shows the penetration state of the metal fine particles and the formation state of the plating film in the example. FIG. 6 schematically shows the concentration distribution of the metal fine particles in the example and the comparative example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Carbon dioxide cylinder 3 Syringe pump 6 1st high pressure vessel 9 Separation recovery machine 11 Recovery tank 13 2nd high pressure vessel (high pressure vessel)
51 Metal Fine Particle 52 Plating Film 61 Reducing Agent 100 High Pressure Device 200 Resin Material (Resin Molded Body)

Claims (12)

A method for producing a composite material including a resin molded body,
Bringing a reducing agent into contact with the molded resin body and allowing the reducing agent to penetrate into the molded resin body;
The method comprises contacting the resin molded body in which the reducing agent has penetrated with high-pressure carbon dioxide in which an organometallic complex is dissolved, and immobilizing the organometallic complex in the resin molded body with the reducing agent. The manufacturing method of the composite material containing the resin molding to perform.   The composite material containing the resin molded body according to claim 1, wherein the resin molded body infiltrated with the reducing agent comes into contact with the high-pressure carbon dioxide in which the organometallic complex is dissolved after the reducing agent is removed from the surface layer. Manufacturing method.   The production of a composite material containing a resin molded body according to claim 1 or 2, wherein the high-pressure carbon dioxide in which the organometallic complex is dissolved is brought into contact with the resin molded body in a temperature atmosphere lower than a thermal reduction temperature of the organometallic complex. Method.   The resin according to any one of claims 1 to 3, further comprising: forming a plating film on the resin molded body on which the organometallic complex is fixed by an electroless plating method containing high-pressure carbon dioxide. A method for producing a composite material including a molded body.   5. The method according to claim 4, further comprising heating the resin molding after fixing the organometallic complex and before forming the plating film at a temperature higher than a thermal reduction temperature of the organometallic complex. A method for producing a composite material including a resin molded body.   The organometallic complex is fixed to the resin molded body by being housed in a high-pressure container together with the resin molded body, and the resin molded body is heated to a temperature higher than the thermal reduction temperature of the organometallic complex. 6. The method for producing a composite material including a resin molded body according to claim 5, wherein the treatment is performed after recovering the organometallic complex from the high-pressure vessel.   The said reducing agent is a manufacturing method of the composite material containing the resin molding of any one of Claims 1-6 which melt | dissolve in a solvent and contact the said resin molding.   The method for producing a composite material including a resin molded body according to claim 7, wherein the solvent is high-pressure carbon dioxide.   The said solvent is water or alcohol, The manufacturing method of the composite material containing the resin molding of Claim 7.   The said organometallic complex is a manufacturing method of the composite material containing the resin molding of any one of Claims 1-9 containing a fluorine.   The resin according to any one of claims 1 to 10, wherein the organometallic complex contains at least one metal element of Pd, Pt, Ni, Cu, and Ag, which are metal elements that function as a catalyst for plating. A method for producing a composite material including a molded body.   The method for producing a composite material including a resin molded body according to any one of claims 1 to 11, wherein the high-pressure carbon dioxide in which the organometallic complex is dissolved is in a supercritical state.

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