JP2009073994A - Inorganic material extracting method in inorganic material dispersed polymer, manufacturing method of composite, molded body of polymer and reflector plate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve such problems that, in forming a film by electroless plating on a polymer surface, in order to assure the adhesion of the plating film, roughing the surface is needed through, for example, a pretreatment heavy in the environmental load, such as etching using an oxidizing agent, and processes such as degreasing and cleaning become necessary to result in affecting the production time and the cost. <P>SOLUTION: By putting a fluid containing a high-pressure carbon dioxide into contact with a polymer in which an acid-soluble inorganic material is dispersed, the inorganic material is extracted from the polymer surface and many anchor-like apertures are formed near the polymer surface. Since the plating metal bites into these anchor-like apertures to adhere fast and thereby the contact area of the interface of the polymer and the plating increases, the plating surface good in adhesion is obtained. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for extracting an inorganic material dispersed on a polymer surface, a method for producing a composite including the method, a polymer molded body molded by the method, and a reflector.

  Conventionally, an electroless plating method is known as a method for forming a metal film on the surface of a polymer member (polymer molded product) at low cost. In the electroless plating method, in order to ensure the adhesion of the plating film, the polymer member surface is etched using an oxidizing agent such as hexavalent chromic acid or permanganic acid as a pretreatment of the electroless plating, and the polymer member Roughen the surface.

  For example, in Patent Document 1, calcium carbonate particles having a size of 10 μm or less are mixed and molded, and calcium carbonate particles in the vicinity of the polymer surface are subjected to chromic acid etching treatment, which is a normal wet plating process, to select calcium carbonate. A method for forming an electroless plating film having a high adhesion by etching to provide an anchor effect is disclosed.

  In addition, polymers that are eroded by such an etchant, 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, and this component is selectively eroded by the etching solution to form irregularities (anchors) on the surface, whereas other polymers have such an etching solution. This is because there are few components that are selectively oxidized and it is difficult to form irregularities on the surface. Therefore, polycarbonate and the like, which are polymers other than ABS, are alloyed by mixing ABS and elastomer in order to enable electroless plating, and some are commercially available as plating grades. 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.

  On the other hand, for example, Patent Document 2 and Patent Document 3 disclose a resin foam as a reflector having a high reflectivity in the visible region to the ultraviolet region, which is used in electrical and electronic parts such as LEDs, or illumination. Some products have been commercialized. In addition, there are reports on several foam moldings for the purpose of increasing the expansion ratio, producing heat-resistant foamed molded articles, and stably supplying fine foams on the order of submicrons.

JP-A-5-59587 JP 2006-146123 A JP 2003-145657 A

  However, in the method of forming an electroless plating film described in Patent Document 1, it is necessary to perform a pretreatment with a large environmental load in order to selectively etch the calcium carbonate particles. Moreover, since steps such as degreasing and washing are required, production time and cost are also affected.

  In Europe, the RoHS (the restriction of the use of ceramics, hazardous materials and electrical equipment) directive that regulates specific hazardous substances contained in electrical and electronic products has been established. For this reason, materials and parts suppliers must ensure that new electrical and electronic equipment that will be introduced to the European market after July 1, 2006 does not contain hexavalent chromium.

  The present invention has been made in view of such a situation. For a polymer in which an inorganic material filler is dispersed, the surface smoothness of the polymer surface is not impaired by a method of short time, low cost, and low environmental load. It aims at providing the method of extracting an inorganic material. High reflectivity is achieved by diffusely reflecting light (mainly in the visible light region of 400 to 700 nm) using holes formed by extracting inorganic materials from foamed cells formed from conventional foamed molded products. An object of the present invention is to provide a reflector having high heat resistance.

  According to the first aspect of the present invention, the inorganic material in the polymer is characterized in that a fluid containing high-pressure carbon dioxide is brought into contact with a polymer in which an inorganic material dissolved in an acid is dispersed, and the inorganic material is extracted from the polymer surface. A material extraction method is provided.

  In the present specification, “high-pressure carbon dioxide” means not only supercritical carbon dioxide but also high-pressure liquid carbon dioxide and high-pressure carbon dioxide gas.

  In general, in polymer materials, various filler materials are used for the purpose of obtaining high mechanical properties that cannot be obtained by a polymer alone, such as strength reinforcement, or for imparting various functions not found in polymers, depending on the application. Added to the polymer and used. In the present invention, an inorganic material that is generally used as a filler material and can be easily dissolved in an acidic liquid, such as calcium carbonate, calcium fluoride, calcium chloride, calcium oxide, calcium hydroxide, metasilicic acid. Calcium, potassium carbonate, potassium bicarbonate, potassium fluoride, potassium chloride, potassium hydroxide, potassium metasilicate, magnesium carbonate, magnesium fluoride, magnesium chloride, magnesium oxide, sodium bicarbonate, sodium fluoride, sodium chloride, metasilicate Sodium, nickel carbonate, nickel hydroxide, nickel oxide, zinc carbonate, zinc fluoride, zinc chloride, zinc oxide, zinc hydroxide, aluminum oxide, aluminum hydroxide, iron fluoride, iron chloride, iron oxide, iron hydroxide, Copper fluoride, copper chloride, copper oxide, water Copper, manganese fluoride, manganese chloride, manganese hydroxide, manganese carbonate, manganese oxide, potassium, calcium, sodium, magnesium, aluminum, zinc, iron, nickel, be used minerals such as copper desirable. That is, an inorganic material that dissolves in high-pressure carbon dioxide is desirable.

  Mineral components unevenly distributed in the vicinity of the surface of the polymer are dissolved in a liquid showing acidity, and a large number of anchor-like holes are opened in the vicinity of the polymer surface. In the subsequent plating process, the plating metal penetrates and adheres firmly to the numerous anchor holes formed on the surface of the polymer, and the contact surface area between the polymer and the plating interface increases. Is obtained.

  In the extraction method of the present invention, first, a polymer material in which the inorganic material is dispersed is prepared by injection molding or the like. It is desirable that the inorganic material has particles of at least 1 μm or less, more desirably particles of 100 nm or less, uniformly dispersed in the vicinity of the polymer surface. By extracting the inorganic material, micropores having a size corresponding to the inorganic material are formed. That is, fine irregularities (anchors) of submicron order size or nano order size can be formed near the surface of the plastic. Therefore, a smooth metal film can be formed on the surface of the polymer from which the inorganic material has been extracted according to the present invention.

  Here, as a method of dispersing the nano-order size inorganic material in the vicinity of the polymer surface, a method by physical mixing and a method by chemical reaction are considered. However, in the method using physical mixing, secondary aggregation of the inorganic material is inevitable. For example, as described in JP-A-2004-27171, the inorganic material is nanocomposited into a polymer by a chemical reaction. The method is preferred.

  When a metal film is formed on the polymer surface obtained by the inorganic material extraction method of the present invention by electroless plating or the like, the anchor effect in the innumerable fine irregularities formed on the polymer surface and the adhesion surface area increase thereby, the adhesion A metal film having excellent properties can be formed. In addition, since the anchor-like pores formed on the surface of the polymer by the inorganic material extraction method of the present invention have a size of sub-micron order to nano-order as described above, the polymer obtained by the extraction method of the present invention When a metal film is formed on the surface of the metal film, it is possible to form a metal film having very excellent smoothness (surface roughness is suppressed).

  In the method for extracting an inorganic material in a polymer of the present invention, an aqueous solution having a low environmental load can be used as an extraction fluid instead of using an oxidant having a high environmental load such as hexavalent chromic acid and permanganic acid as in the past. The extraction fluid contains high pressure carbon dioxide.

  As a result of intensive studies by the present inventors, high-pressure carbon dioxide becomes a highly permeable acidic solvent when the pressure is high and the density is high, and the ability to dissolve and extract an inorganic material that dissolves in an acid dispersed in the polymer in advance. It was found to have In order to maintain the extraction capability, the pressure of the high-pressure carbon dioxide is desirably 3 MPa or more, and because the burden on the high-pressure vessel is increased, it is desirably 25 MPa or less. The temperature of the high-pressure carbon dioxide is preferably lower from the viewpoint of becoming closer to the liquid when the density is higher, but from the viewpoint of activating the molecular motion of the solvent mixed with the high-pressure carbon dioxide such as water, aqueous solvent, alcohol, etc. Higher is desirable. Desirably, the temperature ranges from 10 ° C to 150 ° C. From the viewpoint of low surface tension and high density, supercritical carbon dioxide having a temperature of 31 ° C. or higher and a pressure of 7.38 MPa or higher is more desirable.

  Furthermore, according to the study by the present inventors, it has been found that by combining water and high-pressure carbon dioxide, particularly supercritical carbon dioxide, stronger oxidizing power, that is, solubility to dissolve inorganic materials can be obtained. Yes. It has been found that when a mixed solution of supercritical carbon dioxide and water is used as the extraction fluid, the inorganic material in the vicinity of the polymer surface is further dissolved and easily extracted.

  Moreover, it is preferable that alcohol is further included as an extraction fluid. Originally, carbon dioxide is non-polar and water is polar, so high-pressure carbon dioxide and water are hardly compatible. On the other hand, since alcohol is easily compatible with high-pressure carbon dioxide and water, the extraction effect of the inorganic material is further enhanced.

  In addition, although 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, However, Ethanol was used in this experiment. In addition, when the extraction temperature is high, it is desirable to use alcohol having a high boiling point because the alcohol may boil when the pressure is returned to normal pressure and the mixed solvent may not be stable.

  In addition, since alcohol has a smaller surface tension than water, the surface tension of the extraction fluid to which alcohol is added is significantly reduced. For this reason, it is conceivable that the extraction fluid more easily penetrates into the free volume (inside) of the polymer member, and the extraction capability is improved.

  The extraction fluid of the present invention may contain a surfactant. Thereby, the compatibility between the high-pressure carbon dioxide and the aqueous solution can be improved, and the formation of the emulsion can be promoted. Further, since the surfactant has a function of lowering the surface tension, the extraction fluid can easily penetrate into the polymer member, and the extraction ability is 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 present invention, the inorganic material extraction fluid may contain a plating solution. When a neutral to acidic plating solution is mixed with high-pressure carbon dioxide, the pH is further lowered. And by making it contact with a polymer, the high-pressure fluid with high oxidizing power and permeability easily extracts an acid-soluble inorganic material from the polymer surface. The type of the plating solution used in the present invention is arbitrary as long as it is not an alkaline and stable solution, but a nickel-phosphorus electroless plating solution that can be used in a pH range of 3 to 6 is desirable. This is because, as will be described later, after the inorganic material is extracted from the polymer surface, an electroless plating film can be subsequently formed in the micropores formed by the extraction. In order to enhance compatibility with high-pressure carbon dioxide, it is desirable that the electroless plating solution contains at least one of a surfactant and alcohol.

  According to the present invention, in the polymer material in which the inorganic material is extracted and only the surface is made porous, a metal film can be formed on the porous surface by electroless plating, electrolytic plating, vapor deposition, sputtering, or the like. Since the metal film reflecting the irregularities due to the fine holes on the polymer surface is formed, high adhesion between the polymer and the metal film can be obtained by the physical anchor effect. As a method for forming the metal film, an electroless plating method is desirable because the metal film can be formed in a complicated shape inside the porous polymer portion by being immersed in an aqueous solution. In the present invention, the electroless plating method is arbitrary, but for example, a method after the etching process in the conventional method can be used. An electroless plating film made of Cu, Pd, Ni—P, Ag, Au, or the like can be formed by applying a catalyst and a catalyst activity.

  In the case where a plating solution is included in the inorganic material extraction fluid, in the polymer in which the inorganic material dissolved in the acid is dispersed, metal fine particles functioning as a catalyst core for electroless plating are dispersed in the vicinity of the surface. It is advantageous. As a result, when the inorganic material is extracted and removed from the polymer surface by the above method, the segregated metal fine particles are exposed and come into contact with the plating solution, so that an electroless plating film can be formed directly. The segregation method near the surface of the metal fine particles is arbitrary. For example, a fountain at the time of injection filling can be performed by bringing high-pressure carbon dioxide in which metal fine particles are dissolved into contact with the flow front portion of the molten resin in injection molding. Due to the flow effect, metal fine particles can be segregated in the vicinity of the surface.

  In the present invention, it is desirable that the polymer in which metal fine particles serving as catalyst cores for electroless plating are dispersed has a low electroless plating catalytic activity on the outermost surface. If the concentration of the metal fine particles on the outermost surface is sufficient for the plating to react, the plating reaction is concentrated on the outermost surface of the polymer. For this reason, it is difficult for the plating to grow in the porous portion formed inside the polymer, and the adhesion between the electroless plating film and the polymer may be lowered. In particular, when an inorganic material is extracted from the polymer surface using a high-pressure carbon dioxide fluid containing a plating solution, it is preferable for the following reason that the concentration of metal fine particles on the outermost surface is low. If the concentration of metal fine particles on the outermost surface is low, when the polymer surface is contacted with a mixed fluid of electroless plating solution and high-pressure carbon dioxide at the temperature at which plating reacts, the dissolution and extraction reaction of inorganic materials is performed as the first step. Get up. Next, the plating solution penetrates into the polymer and comes into contact with a sufficient amount of metal fine particle catalyst for the plating reaction. Therefore, as a second step, plating growth occurs from inside the polymer. That is, the inorganic material can be dissolved and extracted from the polymer surface and the plating reaction can be simultaneously performed in one operation.

  In the present invention, a method for forming a polymer having a low concentration on the surface and in which metal fine particles have permeated is arbitrary. For example, metal fine particles such as a metal complex dissolved in high-pressure carbon dioxide in a flow front part of a molding machine. It can be obtained by lengthening the residence time after impregnating. As a result, the metal complex is thermally decomposed inside the thermoplastic cylinder to agglomerate into metal fine particles insoluble in carbon dioxide, and the specific gravity of the metal fine particles becomes heavy. Therefore, segregation occurs on the outermost surface due to the fountain flow phenomenon during injection filling. It becomes difficult to do.

  In the present invention, the kind of the polymer in which the inorganic material dissolved in the acid is dispersed 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 member 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.

  In the present invention, it is desirable to use polyphenylene sulfide as the polymer. Polyphenylene sulfide is a super engineering plastic having a heat resistant temperature of 200 ° C. or higher. Despite being a crystalline material, it has excellent dimensional accuracy in injection molding. It is a material suitable for electric circuit parts of electronic equipment because of its high strength and excellent electrical characteristics, but it is difficult to etch with chemicals because of its excellent chemical resistance. Therefore, in the conventional method, it is difficult to form an electroless plating film. According to the present invention, since the fine holes can be formed by a method having a low environmental load without greatly roughening the surface of the material, it is easy to form a smooth electroless plating film. Therefore, it can be applied to a molded body having a metal film that requires smoothness and heat resistance, such as a headlight reflector of an automobile.

  In the present invention, by dissolving and extracting an inorganic material that dissolves in an acid by the above method, voids having an average pore diameter of at least 50 μm or less, preferably 10 μm or less are formed near the surface of the molded article, A porous body having a porosity of 50% or more and 99% or less when observed is formed. As a result, it is possible to obtain a polymer molded body having excellent surface reflectivity due to irregular reflection in terms of optical characteristics and a low dielectric constant in terms of electrical characteristics. In particular, by making only the vicinity of the surface porous, it is possible to improve the function while maintaining the macro mechanical strength of the molded product.

  In the present invention, in order to obtain a polymer molded body having a large surface porosity and fine pores, it is desirable to use a molded body having a foam in the vicinity of the surface. In particular, it is desirable to obtain a foam on the surface by a foam molding method using a high-pressure fluid such as high-pressure carbon dioxide as a physical foaming agent.

  As a method of forming a foam only in the vicinity of the surface, for example, a step of allowing a high pressure fluid such as liquid carbon dioxide or supercritical nitrogen to permeate the flow front part of the molding machine to a high temperature and high pressure, then a molten polymer and supercritical dioxide. It is possible to adopt an injection molding method in which a high-pressure fluid such as carbon is maintained in a high-pressure state to be compatible, and further, a step of injecting and filling into a mold at a high injection speed.

  Thereby, nitrogen and carbon dioxide, which are compatible with the resin, are gasified and form foamed cells due to rapid decompression in the mold. At the same time, since the polymer is cooled and solidified, fine foam cells can be obtained only in the vicinity of the surface. Further, the formation of the foam may be promoted by further reducing the internal pressure of the polymer by a method of opening the mold immediately after injection filling before cooling (core back).

  Further, in order to maintain the smoothness of the surface of the molded body, a gas such as carbon dioxide may be introduced as a counter pressure into the mold before injection filling.

  In the present invention, an auxiliary agent for forming foam nuclei for growing foam cells can be dissolved in high-pressure carbon dioxide and permeated into the flow front part. By infiltrating metal fine particles or the like, which are foam nuclei, into the polymer in the vicinity of the surface, the number of foam cells is increased and the size is reduced.

  It is possible to increase the number of micropores by extracting an inorganic material after injection molding of a molded body in which a foam is formed in the vicinity of the surface, thereby forming a connected porous body.

  According to the method for extracting an inorganic material in a polymer of the present invention, an inorganic material can be extracted without impairing the surface smoothness of the polymer surface by a low environmental load method. Thereby, fine holes can be formed at a high density on the polymer surface, and a plating film having high adhesion can be formed using the fine holes as anchors.

  Examples of the present invention and comparative examples will be described below.

  In this example, a mixed liquid of supercritical carbon dioxide and water was used as an extraction fluid, and an inorganic material unevenly distributed in the vicinity of the polymer member surface was extracted by batch processing.

  The polymer member of this example is a polyphenylene sulfide (PPS) in which a calcium carbonate filler, which is a mineral, is dispersed as an inorganic material that dissolves in an acid (length 30 mm × width 70 mm × thickness 2 mm, manufactured by Dainippon Ink & Chemicals, Inc. )It was used. The particle size of calcium carbonate was about 1 to 3 μm as a result of analysis by cross-sectional SEM.

  A schematic configuration of the extraction apparatus used in the present embodiment will be described with reference to FIG. The extraction 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. In addition, as shown in FIG. 1, main 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 includes a container main body 2, a lid 3, and an internal container 9 accommodated in the container main body 2. 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. On the other hand, a magnetic stirrer 6 for stirring the extraction fluid 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 of the container body 2 was controlled to an arbitrary temperature in the range of 30 ° C to 150 ° 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 the extraction device 100 of this example, an internal container 9 made of PTFE (polytetrafluoroethylene) that can be accommodated in the metal container body 2 is used, and in the inner container 9, in the vicinity of the surface of the polymer member 102. The ubiquitous inorganic material was extracted.

  As shown in FIG. 1, the inner container 9 includes a container main body portion 9 a in which the extraction fluid 8 and the polymer member 102 are accommodated, and a lid portion 9 b. A holding member 5 is installed on the container main body 9 a, and the polymer member 102 is suspended and fixed to the holding member 5 in a state of being completely immersed in the extraction fluid 8. A magnetic stirrer 6 for stirring the extraction fluid 8 is provided at the bottom of the container main 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.

  In this example, SUS316L was used as a material for forming the high-pressure vessel 1. As a material for forming the high-pressure vessel 1, it is desirable to use a material that is not easily corroded, and other materials such as SUS316, SUS304, Inconel, Hastelloy, and titanium can be used. In this example, 50% nitric acid is immersed in the high-pressure vessel 1 to passivate (passivate), and then a PTFE (polytetrafluoroethylene) film is formed on the inner wall surface as a corrosion prevention film. did. Note that PEEK (polyethyl ether ketone) or the like can also be used as the non-plated growth film.

  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, pressure fluctuations can be absorbed, whereby the pressure inside the high-pressure vessel 1 can be stably maintained.

  Next, an inorganic material extraction method will be described. In this example, extraction fluid 8 was prepared by mixing supercritical carbon dioxide with 100 ml of water. After attaching the polymer member 102 to the holding member 5 shown in FIG. 1, the polymer member 102 was inserted into the container main body portion 9a, and the lid portion 9b was closed. At this time, as shown in FIG. 1, the polymer member 102 is suspended in a state of being completely immersed in 100 ml of water. And this state was hold | maintained at normal temperature (step S11 in FIG. 3).

  Next, the inner container 9 was inserted into the high-pressure container 1 that had been previously adjusted to 80 ° C., and the lid 3 was closed (step S12 in FIG. 3). Immediately, supercritical carbon dioxide was introduced into the high-pressure vessel 1 through the inlet 25 as follows. First, the 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 increased to 15 MPa in the pump. The temperature was 10 ° C. and liquid carbon dioxide. Next, the manual valves 22 and 23 were opened, and 15 MPa of liquid carbon dioxide was introduced into the high-pressure vessel 1 through the inlet 25. The liquid carbon dioxide was changed to a supercritical carbon dioxide by contacting with a high temperature container.

  At this time, the container body 9a and the lid 9b of the inner container 9 are fitted with screws as described above. Even in this state, supercritical carbon dioxide has low viscosity and high diffusivity. 9 is sufficiently introduced into the inside of the inner container 9 through a slight gap in the portion engaged with the screw 9. Then, by stirring with the magnetic stirrer 6, water and supercritical carbon dioxide were mixed and it was set as the extraction fluid 8, and the extraction fluid 8 was made to contact the polymer member 102 (step S13 in FIG. 3). This state was maintained for 30 minutes.

  At this time, the surface of the polymer member 102 is swollen by the introduced supercritical carbon dioxide, and the extraction fluid 8 which is a mixture of supercritical carbon dioxide and water shows acidity and has a low surface tension. Therefore, the calcium carbonate which permeate | transmitted the inside of a polymer and was unevenly distributed in the polymer surface vicinity was extracted (step S14 in FIG. 3). A schematic cross-sectional view of a part of the polymer molded article 102 is shown in FIG. It was confirmed that calcium carbonate 103 was unevenly distributed in the polymer (polyphenylene sulfide) 102, and a continuous void 104 was formed from the surface by extracting calcium carbonate 103 in the vicinity of the surface 102a. In FIG. 2, in order to explain how calcium carbonate 103 is extracted from the surface vicinity 102a of the polymer, the cross section of the polymer is expressed by distinguishing between the surface vicinity 102a and the inside 102b for convenience. The polymer 102 is not divided into three layers.

  Next, after the above-described extraction treatment, supercritical carbon dioxide was exhausted from the high-pressure vessel 1, the inner vessel 9 was taken out from the high-pressure vessel 1, and then the polymer member 102 was taken out from the inner vessel 9.

  Next, the polymer surface state of the polymer member 102 after extraction was confirmed by optical microscope observation (magnification 1000 times). Further, the surface state and surface roughness were confirmed by an atomic force microscope (AFM). As a result, extraction of the polymer surface was confirmed from the optical microscope image and the AFM image, and the surface roughness was confirmed to be Ra = 70 nm from Ra = 30 nm before extraction. When the cross section was cut with FIB and observed with SEM, it was confirmed that a hole was also formed inside.

  In this example, a supercritical carbon dioxide, water and alcohol mixture was used as the extraction fluid 8 and the inorganic material of the polymer member was extracted in a batch process.

  In this example, calcium carbonate was extracted in the same polymer member, apparatus, and method as in Example 1 except that a mixed solution of supercritical carbon dioxide, water, and alcohol was used as the extraction fluid 8. 50 ml each of water and alcohol (ethanol) were used. That is, the volume ratio of water and alcohol was 1: 1.

  Next, as in Example 1, optical microscope observation and atomic force microscope (AFM) measurement were performed. As a result, extraction was confirmed by an optical microscope and AFM, and the surface roughness of the polymer was confirmed to be Ra = 100 nm from Ra = 30 nm before extraction. As in Example 1, formation of holes was confirmed inside.

  In the present example, a mixed liquid of supercritical carbon dioxide, water, alcohol, and a surfactant was used as the extraction fluid 8, and calcium carbonate of the polymer member was extracted by batch processing.

  In addition, ethanol was used as the alcohol and octaethylene glycol monododecyl ether was used as the surfactant. The total mixture of water, alcohol, and surfactant before mixing the supercritical carbon dioxide was 100 ml. Of these, 50 ml of alcohol (ethanol) was used, the surfactant was used in an amount of 3 wt% of the whole, and the remainder was water.

  According to the study by the present inventors, it has been confirmed that in a mixed solution of only water and alcohol, when the alcohol ratio is 30% or less, a stable emulsion is not formed, and the extraction ability becomes extremely small. It has been confirmed that by adding 3 wt% of a surfactant, an emulsion is formed even when the alcohol ratio is 20%, and the extraction ability is further improved.

  In this example, calcium carbonate was extracted by the same polymer member, apparatus and method as in Example 1 except that a mixed solution of water, alcohol and surfactant was used as the extraction fluid 8.

  Next, as in Example 1, optical microscope observation and atomic force microscope (AFM) measurement were performed. As a result, extraction was confirmed by an optical microscope and AFM, and the surface roughness of the polymer was confirmed to be Ra = 110 nm from Ra = 30 nm before extraction.

  In this example, a mixed liquid of supercritical carbon dioxide, water, alcohol, and plating solution was used as the extraction fluid 8, and the inorganic material of the polymer member was extracted by batch processing.

  In addition, ethanol was used as the alcohol, and electroless nickel-phosphorous plating solution (Nicolon DK manufactured by Okuno Pharmaceutical Co., Ltd.) was used as the plating solution. The mixture of water, alcohol, and plating solution before mixing with supercritical carbon dioxide was 100 ml in total, 20 ml of plating solution, 50 ml of alcohol (ethanol), and 30 ml of water. Further, the pH of the extraction fluid was measured and found to be pH = 4.5.

  In this example, calcium carbonate was extracted by the same polymer member, apparatus and method as in Example 1 except that a mixed solution of water, alcohol and plating solution was used as the extraction fluid 8.

  Next, as in Example 1, optical microscope observation and atomic force microscope (AFM) measurement were performed. As a result, extraction was confirmed by an optical microscope and AFM, and the surface roughness of the polymer was confirmed to be Ra = 150 nm from Ra = 30 nm before extraction. In this example, it was confirmed that a three-dimensional hole was well formed inside by using a plating solution which is acidic and mixed with alcohol because it is mixed with supercritical carbon dioxide. It was.

  In this example, only the supercritical carbon dioxide was used as the extraction fluid 8, that is, no liquid that was compatible with the supercritical carbon dioxide was used, and the inorganic material of the polymer member was extracted by batch processing.

  Next, an inorganic material extraction method will be described. In this example, calcium carbonate was extracted by the same polymer member, apparatus, and method as in Example 1 except that extraction was performed only with supercritical carbon dioxide. The treatment time was 2 hours.

  Next, as in Example 1, optical microscope observation and atomic force microscope (AFM) measurement were performed. As a result, the extraction was confirmed by an optical microscope and AFM, and the surface roughness of the polymer was confirmed to be Ra = 70 nm from Ra = 30 nm before extraction.

  In the present example, a mixed liquid of supercritical carbon dioxide, water, and alcohol was used as the extraction fluid 8, and the inorganic material of the polymer member was extracted in batch processing.

  For the polymer member of this example, polyphenylene sulfide (PPS) (length 30 mm × width 70 mm × thickness 2 mm) in which metal aluminum powder having a particle diameter of 1 to 3 μm was dispersed was used as an inorganic material dissolved in acid.

  In this example, the same solution as in Example 2 was used as the mixed solution before mixing the supercritical carbon dioxide, and aluminum powder was used as the inorganic material dispersed in the polymer. The aluminum powder was extracted using the apparatus and method described above.

  Next, as in Example 1, optical microscope observation and atomic force microscope (AFM) measurement were performed. As a result, extraction was confirmed by an optical microscope and AFM, and the surface roughness of the polymer was confirmed to be Ra = 80 nm from Ra = 30 nm before extraction. As in Example 1, formation of holes was confirmed inside.

[Comparative Example 1]
In this example, a mixed liquid of supercritical carbon dioxide, water, alcohol, and plating solution was used as the extraction fluid 8, and the inorganic material of the polymer member was extracted by batch processing.

  The polymer member of this example used polyphenylene sulfide (PPS) (length 30 mm × width 70 mm × thickness 2 mm) in which quartz glass powder having a particle diameter of 1 to 3 μm was dispersed as an inorganic material dissolved in acid.

  In this example, quartz glass was used in the same apparatus and method as in Example 1 except that the same solution as in Example 4 was used as the extraction fluid 8 and quartz glass filler was used as the inorganic material dispersed in the polymer. Powder extraction was performed.

  Next, as in Example 1, optical microscope observation and atomic force microscope (AFM) measurement were performed. As a result, extraction was not confirmed by an optical microscope or AFM, and it was confirmed that the surface roughness of the polymer remained at Ra = 30 nm before extraction. In addition, although the treatment time was increased to 2 hours and further 5 hours, no extraction was confirmed by an optical microscope, and no change in surface roughness was confirmed from AFM.

Table 1 shows a table summarizing the extraction fluid composition in Examples 1 to 6 and Comparative Example 1, the optical microscope after extraction, the extraction confirmation result by AFM, and the average roughness of the polymer surface. In addition, the evaluation criteria of the extraction confirmation result by the optical microscope in Table 1 and the extraction confirmation result by AFM are as follows.
○ Extraction can be confirmed × Extraction cannot be confirmed

  From these results, it was found that extraction of inorganic material was performed efficiently for Examples 1 to 6. Further, as factors for efficient extraction, (i) using a mixture of high-pressure carbon dioxide and at least water, and (ii) reducing the surface tension of the extraction fluid to facilitate penetration into the polymer, (iii) For example, water and high-pressure carbon dioxide are compatible with each other, and (iv) an acidic material is blended. Moreover, although extraction is possible only with high-pressure carbon dioxide as in Example 5, the treatment time is longer. However, if the particle size of the inorganic material segregated on the surface is made fine, the depth at which the inorganic material segregates from the polymer surface becomes shallow, and it is expected that extraction can be performed in a short time.

  In this example, electroless plating was formed by a batch method on a polymer member from which an inorganic material was extracted. In addition, in metal catalyst nucleus provision and electroless nickel plating, high pressure carbon dioxide was used in order to improve adhesion strength.

  In this example, the polyphenylene sulfide substrate from which calcium carbonate in the vicinity of the polymer surface was extracted in Example 2 was used.

  In addition, as the electroless nickel plating solution 8 'used in this example, Nicolon DK manufactured by Okuno Pharmaceutical Co., Ltd. containing nickel sulfate (metal salt), sodium hypophosphite (reducing agent) and the like was used. More specifically, the ratio of each component in 100 ml of the extraction fluid was 20 ml of electroless nickel solution, 50 ml of alcohol (ethanol), and the remaining water. The pH was about 4.5.

  Next, a method for forming a plating film will be described. First, a polymer member 102 'from which an inorganic material (calcium carbonate) was extracted was prepared by the method of Example 2 (Step S21 in FIG. 4). Next, the polymer member 102 and the powdered metal complex were mounted in a high-pressure vessel (not shown) of a surface modification device (not shown). At this time, the polymer member 102 ′ is held in the high-pressure vessel so that the entire surface of the polymer member 102 ′ is in contact with carbon dioxide in a supercritical state (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 permeates into the polymer together with the supercritical carbon dioxide from the surface of the polymer member 102 ′ and the inorganic material extraction part. Next, by maintaining the pressure in the high-pressure vessel at 150 ° C. for 30 minutes, a part of the metal complex that has permeated the entire surface of the polymer member 102 ′ is reduced. In this example, a polymer member 102 ′ in which metal fine particles that act as catalyst nuclei in the electroless plating penetrated into the inside by the above-described process was produced (step S 22 in FIG. 4). This is shown in FIG. The black circles in FIG. 5 indicate the metal fine particles 105 penetrating into the polymer member 102 '. In FIG. 5, in order to explain the state in which the metal fine particles 105 permeate the inside 102b of the polymer, the cross section of the polymer is expressed by distinguishing between the surface vicinity 102a and the inside 102b for convenience. It is not divided into three layers.

  Next, after attaching the polymer member 102 ′ manufactured as described above to the holding member 5 of the inner container 9 a of the high-pressure container 1 shown in FIG. 1, the lid portion 9 b of the inner container was closed. The inner container 9 is filled with 70% of the inner volume of the container body 2 in advance with the electroless plating solution 8 ′, and the polymer member 102 ′ is suspended so as to be completely immersed in the electroless plating solution 8 ′. It becomes a state. And this state was hold | maintained at 60 degreeC. 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 90 ° C.), the plating film does not grow on the surface of the polymer member 102 ′.

  Next, the inner container 9 is inserted into the high-pressure container 1 ′ which has been temperature-controlled in advance at 90 ° C., the lid 3 is closed, and immediately after the introduction of the inlet 25 with supercritical carbon dioxide of 15 MPa in the same manner as in Example 1. And introduced into the high-pressure vessel 1 through contact with the polymer member 102 '. Thereafter, the electroless plating solution 8 ′ was stirred with a magnetic stirrer 6.

  Since a resin having low thermal conductivity is used for the inner container 9, the temperature in the inner container 9 does not rise abruptly. Therefore, at this point, the temperature is lower than the temperature at which the plating reaction occurs, and the plating film does not grow on the surface of the polymer member 102 '. Therefore, when the polymer comes into contact with supercritical carbon dioxide, the surface of the polymer member 102 'swells as in the first embodiment. In addition, since the plating solution mixed with supercritical carbon dioxide has a low surface tension, the electroless plating solution penetrates into the polymer member 102 ′ together with the supercritical carbon dioxide from the polymer surface or from the calcium carbonate extraction hole. Then, the electroless plating solution reaches the fine metal particles present inside the polymer member 102 ′ (step S23 in FIG. 4).

  Thereafter, as time elapses, the temperature in the inner container 9 rises, and finally the temperature of the electroless plating solution 8 rises to the plating reaction temperature. At that time, a plating reaction occurs in the inner container 9, and a plating film 106 grows on the surface of the polymer member 102 '(step S24 in FIG. 4). At this time, in the plating film forming method of the present embodiment, since the electroless plating solution penetrates to the metal fine particles existing inside the polymer member 102 ′ as described above, only the surface of the polymer member 102 ′. Instead, the plating film 106 grows using the metal fine particles present therein as catalyst nuclei. That is, in the plating film forming method of this embodiment, the plating film 106 also grows in the inorganic material extraction part (anchor part) of the polymer member 102 ′ and the free volume inside the polymer, and bites into the polymer member 102 ′. It is formed on the polymer in a slender state and has strong adhesion strength. FIG. 6 shows a schematic diagram thereof. In FIG. 6, as in FIG. 5, the cross section of the polymer is represented by three layers of the vicinity of the surface and the intermediate portion for the sake of convenience, but it is not actually divided into three layers.

  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, a metallic luster of the plating film was uniformly observed on the entire surface of the polymer member 102 ′.

  Next, electrolytic nickel plating, which is a known technique, was applied to deposit 50 μm of electrolytic nickel plating on the surface of the polymer molded article 102 ′. In this example, as described above, a polymer molded product 102 ′ ′ in which a plating film was formed on the polymer was obtained.

  Next, a peel test using a tape (cross-cut tape test) was performed on the polymer molded product 102 ′ ′ having a plating film formed on the polymer. A tape manufactured by Nichiban Co., Ltd., which conforms to the JIS standard, was used. As a result, peeling of the plating film or the like was not confirmed.

Further, the adhesion evaluation of the metal film was also performed on the polymer molded product 102 ′ ′ produced in this example in a high temperature and high humidity environment test of 1000 hr at 85 ° C. and 85% RH. Further, a high temperature test and 10 cycles of a heat cycle test of −40 ° C. to 85 ° C. were performed under conditions of a temperature of 150 ° C. and a standing time of 500 hours. As a result, no decrease in the adhesion of the metal film was observed in all tests. Further, when the peel test was performed again, no peeling or the like occurred. Furthermore, the polymer molded article 102 ′ produced in this example
When the surface roughness Ra of 'was measured, it was Ra = 30 nm equivalent to that of the polymer member before extraction of the inorganic material. That is, according to the plating film forming method of this example, it was found that not only the process can be simplified by a simple method, but also a metal film having high adhesion and smoothness can be formed on the polymer member.

  In this example, 1 μm of a known electroless nickel plating under normal pressure environment was laminated on a polymer provided with inorganic material extraction and plating catalyst nuclei in the same manner as in Example 7. For electroless nickel plating, the proportion of each component in 100 ml is 15 ml of electroless nickel-phosphorous plating solution (Nicolon DK manufactured by Okuno Pharmaceutical Co., Ltd.) similar to that in Example 7, and 85 ml of water. Electroless nickel plating was performed.

  Next, electrolytic nickel plating, which is an existing technique, was applied to the polymer molded article 102 ′ taken out, and 50 μm of electrolytic nickel plating was laminated on the surface of the polymer molded article 102 ′. In this example, a polymer molded product 507 (see FIG. 9) in which a plating film was formed on the polymer as described above was obtained. When the molded product in this example was evaluated for adhesion of the plating film in the same manner as in Example 7, it was similarly good.

  In this example, first, polyphenylene sulfide in which Pd fine particles and calcium carbonate fine particles were mixed was molded using an injection molding machine. Thereafter, extraction of calcium carbonate and electroless plating were simultaneously performed in the same injection molding machine using a mixed solution of supercritical carbon dioxide and a plating solution, and a headlight reflector (reflector) for automobiles was produced.

  A schematic configuration of the apparatus for producing a polymer molded product used in this example will be described with reference to FIG. As shown in FIG. 7, the manufacturing apparatus 500 according to the present embodiment mainly supplies a vertical injection molding apparatus unit 503 including a mold, distilled water containing high-pressure carbon dioxide, and electroless plating molds. Calcium carbonate extraction and electroless plating unit 501 for controlling discharge, and surface reforming unit 502 for infiltrating high-pressure carbon dioxide in which the metal complex 200 is dissolved into the molten resin in the plasticizing cylinder of the injection molding unit 503. It consists of.

  As shown in FIG. 7, the vertical injection molding apparatus unit 503 mainly includes a plasticizing and melting apparatus 110 that plastically melts a forming resin of a polymer molded product, 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, as a material for resin pellets (not shown) supplied from the hopper 50 into the plasticizing cylinder 52, polyphenylene sulfide containing calcium carbonate filler having a particle diameter of 500 nm to 1 μm was used.

  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. The movable mold 54 has a plating solution introduction path 61 for supplying and discharging a high-pressure carbon dioxide electroless plating solution to and from a cavity 504 defined between the movable mold 54 and the fixed mold 53. 62 is 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 200 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 palladium metal complex (hexafluoroacetylacetona palladium (II)) was used as a raw material for the fine metal 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, a nickel-phosphorus electroless plating solution containing 15 vol% of the stock solution and 50 vol% of alcohol (ethanol) was used.

  Next, a method for forming a polymer molded product in which metal fine particles are permeated 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 200 was dissolved in ethanol in the dissolution tank 35, and the ethanol in which the metal complex 200 was dissolved was pressurized 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. The pressurized carbon dioxide and ethanol in which the metal complex 200 was dissolved were mixed in the pipe 80 (a high-pressure mixed fluid was generated). 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. Further, the feeding of the high-pressure mixed fluid of ethanol solution and high-pressure carbon dioxide from both syringe pumps 20 and 34 was performed by switching the control of each syringe pump 20 and 34 from pressure control to flow rate control. 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 65 moves backward (moves to the left side 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 lower the internal pressure of the molten resin 66, and at the same time, both syringe pumps 20 and 34 are switched from pressure control to flow rate control. The high-pressure mixed fluid 67 was introduced into the molten resin 66 at the flow front portion in the plasticizing cylinder 52 via the introduction valve 65 while the flow rate of carbon was 1:10 by the above-described method (see FIG. 8B). Status). 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 was advanced to increase the resin pressure again to 20 MPa, and the introduction pin 64 was 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.

  Subsequently, after closing both automatic pumps 20 and 34 in the piping 80 and the automatic valves (not shown) in the pipe 80, the flow rate of the ethanol solution in which the high-pressure carbon dioxide and the metal complex 200 supplied to the plasticizing and melting apparatus 110 are dissolved is the syringe pump 20. , 34 was replenished. 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, the molded product was cooled and solidified (state shown in 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, the metal fine particles derived from the metal complex 200 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 molded product 507 is impregnated with the metal fine particles. A polymer molded product 507 is obtained (step S61 in FIG. 11). In this example, in this way, the metal fine particles were dispersed in the skin layer 505 as the epidermis, and the polymer molded product 507 having almost no metal fine particles in the core layer 506 as the endothelium was obtained.

  In this example, the resin pressure of the flow front portion in the plasticizing cylinder 52 was kept at 20 MPa to sufficiently infiltrate the metal fine particles into the resin, and then the internal pressure of the resin was reduced to 1 MPa. By this operation, the metal complex 200 is thermally decomposed under high temperature and high pressure to form a cluster, and changes into metal fine particles having a specific gravity heavier than the metal complex that is an organic substance. In addition, since carbon dioxide becomes a low-pressure gas, metal fine particles and carbon dioxide gas are less likely to come out on the surface during injection filling. Thereafter, in this example, the injection speed until injection filling was set to a low speed of 100 m / s, and a molded product in which Pd as metal fine particles was not sufficiently segregated on the outermost surface was injection molded. That is, although the metal fine particles are dispersed in the skin layer 505, the outermost surface has a surface state in which the amount contributing to the catalyst nucleus is insufficient. The reaction temperature of the plating solution used in this example is 60 to 90 ° C. It was confirmed in advance that plating did not grow on the surface even when the molded article of this example was immersed for 10 minutes in a plating solution at 70 ° C. at atmospheric pressure.

  Next, a method for forming a plating film will be described. The polymer molded product 507 in which metal fine particles were dispersed inside the surface produced as described above was subjected to electroless plating 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 molded product 507.

  Next, an electroless plating solution containing high-pressure carbon dioxide was introduced into the cavity 508 as described below and brought into contact with the polymer molded product 507. First, an alcohol electroless plating solution supplied from the plating tank 11 of the electroless plating apparatus unit 501 and a high-pressure carbon dioxide of 15 MPa supplied from the buffer tank 36 in the high-pressure vessel 10 in advance 7: 3. The ratio was mixed. In the present invention, it is desirable that the mixing ratio of the plating solution and the high-pressure carbon dioxide is in the range of 9: 1 to 5: 5, and the amount of the plating solution is large. At this time, the high-pressure carbon dioxide and the electroless plating solution were mixed 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 90 is operated, and an electroless plating solution containing high-pressure carbon dioxide is circulated through the circulation flow path including the high-pressure vessel 10, the pipe 15, and the cavity 508, so that the surface of the polymer molded product 507 is temporarily removed. The electrolytic plating solution was retained and contacted to form a plating film (nickel phosphorus film) (step S63 in FIG. 11). At this time, the plating reaction does not occur on the outermost surface of the polymer molded product, and the electroless plating solution quickly penetrates from the surface of the polymer 507 while dissolving the calcium carbonate inside the polymer, and is dispersed inside the polymer molded product 507. A plated film grows using metal fine particles as catalyst nuclei. That is, the plating film formed on the polymer molded product 507 grows in a state of being bitten into the polymer molded product 507, so that a plating film having excellent adhesion was 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 molded product 507 as described above, the electroless plating solution containing high-pressure carbon dioxide is recovered through the recovery container 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 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 molded product 507, and the plating solution residue remaining in the cavity 508 is high-pressured. It was discharged out of the mold together with carbon dioxide. When the internal pressure of the cavity 508 became zero as monitored by the pressure sensor 59, the mold was opened and the polymer molded product 507 was taken out.

  Next, the polymer molded product 507 taken out was subjected to normal silver plating after annealing, and a silver plating film was laminated on the surface of the polymer molded product 507. In this example, a polymer molded product 507 having a plating film formed on the surface as described above was obtained.

  FIG. 12 shows a schematic cross-sectional view of a part of the polymer molded product 507 produced in this example. It was confirmed that the metal fine particles 600 were dispersed inside the skin layer 505 of the polymer molded product 507 produced in this example. Further, a nickel-phosphorus metal film 509 grown in the mold is formed on one side of the polymer molded article 507, and the nickel-phosphorus metal film 509 grew from the inside of the polymer molded article 507. (The permeation layer of the metal film 509 was formed). Further, a silver highly reflective film 510 is formed on the nickel-phosphorus metal film 509.

  Moreover, the adhesion evaluation of the metal film was also performed on the polymer molded product 507 produced in this example in a high-temperature and high-humidity environment test at 85 ° C. and 85% RH for 1000 hours. Further, a high temperature test and a heat shock test 20 cycles of −30 ° C. to 150 ° C. were performed under conditions of a temperature of 150 ° C. and a standing time of 500 hours. As a result, no decrease in the adhesion of the metal film was observed in all tests. Furthermore, when the surface roughness Ra of the polymer molded product 507 produced in this example was measured, Ra = 50 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, so that not only the process can be simplified, but also a metal film having high adhesion and smoothness is heat resistant. It was found that it can be formed into a high resin material.

  In this example, after a polyphenylene sulfide foam mixed with calcium carbonate fine particles was molded using an injection molding machine, calcium carbonate was extracted with a mixed solution of supercritical carbon dioxide, water, and alcohol in a batch mode. In this example, a visible light region reflector for an electric / electronic component such as an LED was produced.

  In this example, polyphenylene sulfide in which 60% of calcium carbonate having a particle size of about 3 to 6 μm was mixed was used. In this example, a horizontal injection molding machine 107 whose main part is shown in FIG. 13 is used, and a nickel metal complex 201 is dissolved as a foam nucleating agent serving as a base point of foaming, and a metal complex is dissolved in high-pressure carbon dioxide 203 together with alcohol 202. It was dissolved in the tank 235 and permeated into the flow front part of the molding machine in the same manner as in Example 9.

  In this example, a metal complex was used as a material that became nanoscale fine particles inside the molten resin and functions as a foaming nucleus when injection-filled into a mold. The flow front part was infiltrated in the same manner as in Example 9 except that a nickel complex (hexafluoroacetylacetonato nickel) was used as the metal complex. That is, a mixed fluid of liquid carbon dioxide and ethanol in which a metal complex having a pressure of 15 MPa is dissolved is introduced into the flow front portion after plasticization measurement, and then the internal pressure of the resin is increased to 20 MPa to make the high-pressure fluid compatible with the resin. It was.

  Further, in this example, injection molding was performed in the mold at a high injection speed of 1000 mm / s from a state in which the resin internal pressure was maintained at 20 MPa. Immediately after injection filling, the mold was opened 500 μm. As a result, a molded body having foamed cells having a foamed cell diameter of 6 to 10 μm in the vicinity of the surface of the molded product and a porosity of 15% was obtained. Foamed cells were not confirmed at the center of the molded body. Foamed cells were observed from the surface on both sides to a depth of 300 μm with respect to the thickness of the molded product of 2 mm.

  Next, extraction of calcium carbonate was performed in a batch system with the same extraction fluid composition (water, mixed solvent of ethanol and supercritical carbon dioxide) as in Example 2. Since calcium carbonate was precipitated in the vicinity of the surface of the molded body at high density, in the extraction, the previously formed foamed cells and the respective extraction pits overlapped to form a connected porous body 108 as shown in FIG. all right. The foam cell diameter on the outermost surface was 8 to 10 μm, and the porosity in the vicinity of the surface 607a was 80%.

  Further, when a spectral spectrum in the visible region (400 to 700 nm) of this resin molded product 607 was measured, it had a substantially uniform reflectance at each wavelength, and averaged 90%. As described above, according to the method of this example, it was possible to produce a reflector having a good reflectance in the visible light region using a resin material having high heat resistance.

  In the embodiments described above, the types and concentrations of the alcohol, surfactant, plating solution and the like used are merely examples, and are not limited to these types and numerical values. In the above-described embodiments, the present invention has been described with respect to an example in which the present invention is applied to the production of a headlight reflector for an automobile and the production of a visible light region reflector for an electric / electronic component such as an LED. It can be applied to the production of an arbitrary reflector that requires high heat resistance and high reflectance.

  In the method for extracting an inorganic material in a polymer of the present invention, a simple and environmentally friendly method can be used to create a hole in the vicinity of the polymer surface and use it as an anchor to form a plating film having high adhesion. Therefore, it is optimal as a plating pretreatment method for forming a plating film having excellent adhesion to various types of polymers. Furthermore, by providing fine holes with high density near the surface and forming a plating film on the inner wall of the holes, it is optimal as a method for forming a polymer plate with good reflectivity in the visible light region.

  In addition, in the method for forming a plating film 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. Therefore, it is suitable as a method for producing a reflector for an automobile headlight or a reflector for an electric / electronic component such as an LED.

1 is a schematic configuration diagram of an extraction device used in Example 1. FIG. It is a partial cross section figure of the polymer molded product from which the calcium carbonate unevenly distributed in the surface vicinity was extracted. It is a flowchart which shows the procedure which extracts an inorganic material from the polymer surface vicinity of this invention. It is a flowchart which shows the procedure which forms an electroless plating film | membrane in the polymer from which the inorganic material of this invention was extracted. It is a partial cross section figure of the polymer member which the metal microparticles permeate | transmitted inside. FIG. 6 is a partial cross-sectional view of a polymer member showing a state in which a plating film has grown using metal fine particles as catalyst nuclei. 10 is a schematic configuration diagram of a polymer molded product manufacturing apparatus used in Example 9. FIG. (A) And (b) is an expanded sectional view of the introduction valve vicinity of the plasticization melting apparatus in the manufacturing apparatus of FIG. It is a figure which shows the state which injected and filled the molten resin in the metal mold | die in the manufacturing apparatus of FIG. 7, and was solidified by cooling. It is a figure which shows the state in which the clearance gap was made between the fixed metal mold | die and the polymer molded product in the manufacturing apparatus of FIG. 10 is a flowchart showing a procedure for forming an electroless plating film in Example 9. 10 is a partial cross-sectional view of a polymer molded product produced in Example 9. FIG. FIG. 10 is a configuration diagram showing a main part of a horizontal injection molding machine used in Example 10. FIG. 6 is a partial cross-sectional view of a polymer molded product produced in Example 10.

Explanation of symbols

  8 Extraction fluid 11 Plating tank 21 Liquid carbon dioxide cylinder 100 Extraction device 102 Polymer member 103 Calcium carbonate 104 Void 105 Metal fine particle 106 Plating film 200 Metal complex 500 Polymer molded product manufacturing device 507 Polymer molded product

Claims (20)

  A method for extracting an inorganic material in a polymer, comprising bringing a fluid containing high-pressure carbon dioxide into contact with a polymer in which an inorganic material dissolved in an acid is dispersed, and extracting the inorganic material from the polymer surface.   The method for extracting an inorganic material in a polymer according to claim 1, wherein the fluid containing the high-pressure carbon dioxide contains water.   The said inorganic material is a mineral, The inorganic material extraction method in the polymer of Claim 1 or 2 characterized by the above-mentioned.   The method for extracting an inorganic material in a polymer according to any one of claims 1 to 3, wherein the fluid containing high-pressure carbon dioxide contains alcohol.   The method for extracting an inorganic material in a polymer according to any one of claims 1 to 4, wherein the fluid containing the high-pressure carbon dioxide contains a surfactant.   The method for extracting an inorganic material in a polymer according to any one of claims 1 to 5, wherein the fluid containing high-pressure carbon dioxide contains an electroless plating solution.   The method for extracting an inorganic material in a polymer according to any one of claims 1 to 6, wherein the high-pressure carbon dioxide is supercritical carbon dioxide having a pressure of 7.38 MPa to 25 MPa.   The method for extracting an inorganic material in a polymer according to any one of claims 1 to 7, wherein the polymer is subjected to electroless plating after the inorganic material is extracted from the polymer surface.   The method for extracting an inorganic material in a polymer according to any one of claims 1 to 8, wherein the polymer is polyphenylene sulfide (PPS).   The method for extracting an inorganic material in a polymer according to any one of claims 1 to 9, wherein the polymer in which the inorganic material dissolved in the acid is dispersed has a foam cell.   A polymer molded body in which an inorganic material that dissolves with an acid is dispersed, wherein voids are formed in the vicinity of the surface, and metal fine particles are dispersed.   The polymer molded body according to claim 11, wherein the concentration of the inorganic material is low in the vicinity of the surface.   The polymer molded body according to claim 11 or 12, wherein the polymer molded body is polyphenylene sulfide.   A polymer molded body in which an inorganic material that dissolves with an acid is dispersed, wherein a metal film is formed on the surface, and metal fine particles are dispersed in the vicinity of the surface.   The polymer molded body according to claim 14, wherein the concentration of the inorganic material is low in the vicinity of the surface.   The polymer molded body according to claim 14 or 15, wherein the polymer molded body is polyphenylene sulfide.   The reflector which is a polymer molded object as described in any one of Claims 11-13.   The reflector which is a polymer molded object as described in any one of Claims 14-16. Extracting the inorganic material from the polymer by the inorganic material extracting method in the polymer according to any one of claims 1 to 7,
Applying the electroless plating to the polymer from which the inorganic material has been extracted.   The method for producing a composite according to claim 19, further comprising electroless plating after performing electroless plating on the polymer from which the inorganic material has been extracted.

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