JP2004218062A - Molded product, and method and device for injection molding - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a molded product with a surface thereof reformed so as to be applicable to, for example, electroless plating totally or selectively without roughening the surface during the injection molding, a method for manufacturing the same, a die used therefor, and an injection molding device. <P>SOLUTION: The mold product is formed of thermoplastic resin. Supercritical fluid of molten organic matters such as organometallic complex is introduced in a flow-front part of the thermoplastic resin, and injection-molded. The organometallic complex or metal particles with ligands thereof removed therefrom are segregated from a portion in a vicinity of the surface of the molding to the surface thereof. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention generally relates to an injection molded article made of a thermoplastic resin (or a molten resin), a method for producing the molded article using injection molding, a mold and an injection molding apparatus used for such injection molding, and in particular, And surface modification of molded articles using injection molding.
[0002]
[Prior art]
Although there are many plastic molded products produced by injection molding, the physical properties are determined by the resin material to be plasticized and melted. Further, depending on the use, the plastic molded product may be subjected to various printing and painting, formation of a conductor or a metal film, joining of the molded products, and other post-processing. When it is necessary to perform such post-processing, it is generally practiced to activate the surface of the plastic molded article to modify the surface in order to improve workability.
[0003]
On the other hand, electroless plating is widely used as a means for forming a metal conductive film on the surface of an electronic device made of a plastic molded product. The plastic electroless plating step is slightly different depending on the material and the like, but is generally performed according to the flow shown in FIG.
[0004]
First, the surface oil or the like is removed by “degreasing” the molded article, and then the surface is roughened by “etching”. A chromic acid solution or an alkali metal hydroxide solution is used for etching, but these etching solutions require post-treatment such as "neutralization", which is a factor in increasing the cost, and also requires the use of highly toxic etchants. There is a handling problem due to its use. Next, after improving wettability by "wetting" by treating with a surfactant aqueous solution, a catalyst is attached to the plastic surface by "catalyst (catalyst application)". In the "catalyst" process, for example, in the case of a palladium catalyst, the plastic is impregnated with an aqueous hydrochloric acid solution of tin chloride and palladium chloride. After the “catalyst”, the plating catalyst is activated by contacting with an acid such as sulfuric acid or hydrochloric acid by “accelerator (catalyst activation)”. After the above process, "electroless plating" can be performed for the first time.
[0005]
Several processes that do not require roughening by etching have been conventionally proposed (for example, Patent Documents 1 and 2). In these methods, a thin film containing a plating catalyst is formed on a plastic surface with an organic binder or an ultraviolet curable resin. Furthermore, a technique for irradiating a plastic surface with an ultraviolet laser in a gas atmosphere of an amine compound or the like to modify the surface has already been proposed (for example, Patent Document 3). Other than this, reforming techniques by corona discharge treatment, plasma treatment, ultraviolet treatment and the like have been conventionally known.
[0006]
On the other hand, a semi-additive method is known as a method of forming wiring on a circuit board by electroless plating or electrolytic plating. This flow is shown in FIG. In this method, first, a plating layer of 1 to 2 μm is formed on the entire substrate by “electroless plating” in the same process as described above. Next, after forming a "photosensitive film or resist", masking and "exposure and development" are performed to form a film or resist layer provided with a wiring pattern. Further, electrolytic plating is formed on the electroless plating layer exposed by the patterning by an “electrolytic plating” process. Next, after removing the film and the resist, the plated wiring is completed by removing the electroless plating layer other than the wiring portion by soft etching. In the case of copper plating, post-processing called "blackening treatment" for forming fine projections on (oxidized) copper to enhance the anchoring action with the resin is sometimes performed because of poor adhesion to the resin.
[0007]
A method of providing a three-dimensional circuit in a molded product has also been conventionally proposed (for example, Patent Documents 4 and 5). In such a method, first, a plastic of a three-dimensional circuit board is formed by resin molding. Next, after the surface is roughened and a catalyst is applied, electroless plating is formed on the entire surface, and a photoresist is applied on the entire surface. Then, after exposure with a photomask covered, development is performed to remove portions other than the circuit pattern forming portion. After electrolytic plating and electroless plating of Ni or Au are formed thereon, the photoresist is peeled off, and unnecessary portions of the electroless plating are removed by etching. It is difficult to form a uniform photoresist on the three-dimensional structure. Patent Document 4 proposes to use an electrodeposition resist, but such a resist has a drawback of low alkali resistance.
[0008]
As a circuit forming method using injection molding, the following method is disclosed (for example, Patent Document 6). According to Patent Document 6, first, a roughened surface of about Ra1 to 5 μm is provided on a circuit forming surface of a mold surface, and a catalyst core is attached to the entire surface of the mold before injection molding. The catalyst nuclei are entirely transferred by being formed by injection molding. Electroless plating is firmly adhered only on the roughened molding surface with strong adhesion of catalyst nuclei, and adhesion is weak on other non-roughened parts, so electroless plating other than circuits after electrolytic plating It can be removed together with the nuclear catalyst during the etching for removing the plating layer.
[0009]
[Patent Document 1]
JP-A-9-59778
[Patent Document 2]
JP 2001-303255 A
[Patent Document 3]
JP-A-6-87964
[Patent Document 4]
JP-A-4-76885
[Patent Document 5]
JP-A-1-206692
[Patent Document 6]
JP-A-6-196840
[0010]
[Problems to be solved by the invention]
However, there has not been proposed a technique having a wide range of applications that can simultaneously perform surface modification during molding of injection molding. In addition, the conventional plastic electroless plating process is complicated and expensive, and a large amount of harmful substances must be used. Furthermore, the conventional process that does not require surface roughening by etching is a process in which a molded article is manufactured and then processed in another step, and is not suitable for mass production. Further, the conventional method of forming plated wiring on a plastic molded product has complicated steps before and after electroless plating, requires the use of a large amount of highly toxic organic solvents, and furthermore, the plastic surface is roughened. There was a problem. Further, according to the method of Patent Document 6, the surface of plastic can be modified at the time of injection molding. However, a method of uniformly attaching the catalyst nuclei to the mold surface is not specifically described. In addition to the need for roughening on a mold, a step of etching after molding is required.
[0011]
Therefore, the present invention has been made in order to solve the above problems, and the surface can be entirely or selectively, without roughening the surface during injection molding, for example, as applicable to electroless plating. It is an exemplary object to provide a modified molded article, a method for producing the same, a mold used for the molded article, and an injection molding apparatus.
[0012]
[Means for Solving the Problems]
A molded article according to one aspect of the present invention is a molded article made of a thermoplastic resin, wherein the molded article contains an organic substance different from the thermoplastic resin, or a metal element therein, and the organic substance or the metal element Is characterized by being arranged from the vicinity of the surface of the molded article to the surface (that is, segregation, local existence). Since such a molded article contains an organic substance and the like inside and on the surface, it has high stability such as being less likely to be peeled off from the surface than formed by lithography or the like. The organic substance or the like may be formed over the entire surface or at a specific position. The range of “near the surface” can be appropriately selected depending on the purpose of the surface modification and the material used, but preferably refers to a range of 100 μm or less from the surface, more preferably 10 μm or less from the surface. Further, depending on the purpose of the surface modification and the material used, it is also possible to modify the nanoscale thickness from the surface.
[0013]
The molded article may further include a plating layer formed using the metal element as a nucleus. The plating layer may form an electric wiring pattern.
[0014]
The molded article may further have a foam inside the thermoplastic resin.
[0015]
For example, the organic substance is an organometallic complex. Further, the metal element may be metal particles or metal fine particles. Further, the metal element may be a metal element generated by removing some or all of the ligands of the organometallic complex. By arranging the organometallic complex or the metal element on the resin surface entirely or selectively, it is possible to impart conductivity entirely or locally or to enhance the magnetism. Using a resin, for example, the biochip can be easily sealed. That is, it is possible to easily seal the glass substrate and the plastic by bonding a plastic having fine irregularities serving as a fluid flow path to a glass substrate or the like and generating a magnetic force from the back surface of the glass substrate. Become. In addition, by segregating the metal element entirely or partially on the surface, it is possible to produce a molded article having different mechanical properties in that portion. The portion where the metal element is segregated has improved sliding resistance, hardness and the like as compared with other portions. Further, a magnetic circuit pattern can be formed using a metal having magnetism. If a fluorescent substance such as a rare earth complex is used as the metal complex, a molded article having a fluorescent pattern on the surface can be formed. This can be applied as a display element.
[0016]
The type of the metal complex is arbitrary, but a Pd complex, a Ni complex, a Co complex, a Pt complex and the like are desirable. More specifically, platinum dimethyl (cyclooctadiene), bis (cyclopentadienyl) nickel, bis (acetylacetonate) palladium and the like are desirable. The electroless plating apparatus may further include an electroless plating layer formed using the metal element as a nucleus. Thereby, the plating layer can be easily formed at the selected position. The plating layer forms, for example, an electric wiring pattern. That is, the molded article of the present invention can be used as an electric wiring board. Further, the plastic molded article may further have a foam cell. This makes it possible to reduce the weight of the plastic molded product, enhance the heat insulating effect, and increase the rigidity to weight ratio.
[0017]
Of course, the organic substance is not limited to the organometallic complex. By using polypropylene glycol as an organic substance, a hydrophobic plastic surface such as polyethylene terephthalate can be selectively hydrophilized. Similarly, by using a fluorine compound, selective water repellent treatment and reduction of the refractive index can be achieved.
[0018]
A manufacturing method as another aspect of the present invention is a method of manufacturing a molded product by injection molding a thermoplastic resin, wherein the thermoplastic resin in a mold, a supercritical fluid and the supercritical fluid A step of injecting the dissolved substance, wherein the surface of the molded article is modified. Since such a manufacturing method can use a supercritical fluid to infiltrate a substance into the surface and inside of a thermoplastic resin, as described above, it is more excellent in stability of the substance than formed on the surface by etching or the like. Molded articles can be manufactured.
[0019]
Available supercritical fluids are air, CO ₂ , Butane, pentane, methanol, etc. are optional, but have the same solubility as n-hexane, work as a plasticizer for certain thermoplastic resin materials, and have a proven track record in injection molding and extrusion molding. ₂ Is desirable. The substance to be dissolved in the supercritical fluid is not particularly limited, and examples thereof include metal complexes (platinum dimethyl (cyclooctadiene), bis (cyclopentadienyl) nickel, bis (acetylacetonate) palladium), Polypropylene glycol and the like. In particular, by using a metal complex, the adhesion of plastics to electroless plating can be selectively improved.
[0020]
Further, the thermoplastic resin is not particularly limited, polycarbonate, polymethyl methacrylate, polyether imide, polymethyl pentene, amorphous polyolefin, polytetrafluoroethylene, liquid crystal polymer, styrene resin, polymethyl pentene, Polyacetal or the like, a mixture thereof in a complex type, a polymer alloy containing these as a main component, or a mixture of these with various fillers can be used.
[0021]
The injecting step may include a step of introducing the supercritical fluid and the substance into a flow front as a flow front end of the thermoplastic resin during injection filling. According to such a method, the thermoplastic resin at the flow front portion forms a surface layer while being pulled by the mold surface due to the fountain flow phenomenon (fountain effect) of the flowing resin in the mold. The substance that has melted and penetrated the flow front in the resin is placed in a layer near the surface in contact with the mold. If the substance has a certain degree of solubility in the supercritical fluid, it can be uniformly dispersed only on the surface of the molded article. Therefore, application to various plastic surface modification technologies can be expected. CO as supercritical fluid ₂ As described above, it works as a plasticizer, so that the fluidity of the thermoplastic resin can be improved and the growth of the solidified layer on the surface in contact with the mold can be suppressed. In the injecting step, the supercritical fluid and the substance may be included in a filling start portion of the thermoplastic resin.
[0022]
In the pouring step, the supercritical fluid and the substance may be introduced into the mold at the time of injection filling as counter pressure for applying pressure opposite to the flow direction of the injected thermoplastic resin. By the counter pressure, the dissolved substance can be arranged near the surface of the molded article. The counter pressure is supercritical fluid CO as a foaming agent. ₂ And N ₂ When the gas is kneaded in the thermoplastic resin, the internal pressure of the thermoplastic resin is rapidly reduced in the mold during injection, the foam cell diameter is enlarged, and a pattern called a swirl mark is formed on the surface, deteriorating the surface properties Can be suppressed.
At the same time, as described above, the supercritical fluid and the dissolved substance can be arranged only on the surface by the fountain flow phenomenon.
[0023]
The injecting step is a step of introducing the supercritical fluid into which the substance does not dissolve into the thermoplastic resin except for the flow front as a flow front portion of the thermoplastic resin, and the step of using the supercritical fluid to form the gold. Forming a foam inside the thermoplastic resin injected into the mold. According to such a method, it is possible to lower the dielectric constant of the material by forming a fine foam cell inside while modifying the resin surface. It is suitable for a planar antenna such as a high-frequency electric circuit board, a MID (Mold Interconnect Device), and a millimeter-wave antenna.
[0024]
The injecting step may include a step of filling the mold with the thermoplastic resin, and a step of introducing the supercritical fluid and the substance into a specific position in the mold. By dispersing the substance near the specific position on the surface of the resin and in the vicinity thereof, the surface of the resin molded product can be locally modified. The method may further include disposing the substance on the thermoplastic resin at the specific position by adjusting a pressure and / or a temperature of the mold. Thereby, it is possible to partially modify the surface of the molded article without irregularities.
[0025]
The substance is, for example, an organic substance or a metal element. The organic substance is an organic metal complex, and the metal element is metal particles excluding a ligand of the organic metal complex. Since the metal complex is dissolved to some extent in the supercritical fluid, it can be disposed on the surface of the molded article without deteriorating the surface properties. Further, by removing the organic portion of the metal complex and precipitating the metal element, the metal complex can act as a catalyst nucleus for electroless plating, so that the plating adhesion on the resin surface is improved without any pretreatment.
[0026]
The substance may be a metal element excluding a ligand of an organometallic complex, and the method further includes a step of forming a pattern formed of a plating layer on a portion where the metal element is deposited by electroless plating. May have. A metal conductive film can be easily formed by electroless plating. The pattern may include irregularities, and may further include a step of removing a convex portion of the pattern after the forming step. Further, the portion may include irregularities, and may further include a step of removing a convex portion of the portion before the forming step. A desired pattern can be formed by either method.
[0027]
The method may further include, after the injecting step, a step of compressing the thermoplastic resin, and after the compressing step, a step of expanding the volume of the cavity of the mold to foam the thermoplastic resin. Good. According to such a method, it is possible to lower the dielectric constant of the material by forming fine foam cells inside while simultaneously performing the selective modification of the plastic surface. It is suitable for a planar antenna such as a high-frequency electric circuit board, a MID (Mold Interconnect Device), and a millimeter-wave antenna.
[0028]
In the injecting step, a predetermined pattern is formed on a first surface pressed against the filled thermoplastic resin, and pressed on the thermoplastic resin, and a second surface opposite to the first surface is formed on the first surface. A stamper provided with a hole communicating with the pattern at the specific position may be used. By making the pattern a stamper, the wiring circuit can be easily changed. In addition, a desired circuit pattern can be formed by forming a pattern at a specific position.
[0029]
A mold according to another aspect of the present invention is a mold used to manufacture a molded article by injection molding a thermoplastic resin, wherein a supercritical fluid and the supercritical fluid are contained in the mold. It has a feature of introducing a substance dissolved in a fluid as counter pressure. Since such a mold uses a supercritical fluid and a substance as counter pressure, it has the same effect as the above-described method.
[0030]
A mold according to another aspect of the present invention is a mold used for manufacturing a molded product by injection molding a thermoplastic resin, and a concave portion is formed at a specific position on a cavity forming surface of the mold. Alternatively, a convex part is formed, and the introduction part for injecting a supercritical fluid and a substance dissolved in the supercritical fluid from the outside is connected to the concave part or the convex part. The concave or convex shape can increase the local adhesion of the substance.
[0031]
Injection molding apparatus as another aspect of the present invention is a mold that forms a cavity for filling a thermoplastic resin, and a plasticizing cylinder for introducing the thermoplastic resin into the cavity of the mold. A mechanism for introducing a supercritical fluid and a substance dissolved in the supercritical fluid into the plasticizing cylinder, and including the supercritical fluid and the substance in a flow front as a flow front end of the thermoplastic resin. Such an injection molding apparatus has the same effect as the above-described method because the supercritical fluid and the substance are contained in the flow front of the resin.
[0032]
Injection molding apparatus as another aspect of the present invention is a mold that forms a cavity for filling a thermoplastic resin, and a plasticizing cylinder for introducing the thermoplastic resin into the cavity of the mold. And a mechanism for introducing a supercritical fluid into a portion other than the flow front as a flow front end portion of the thermoplastic resin in the plasticizing cylinder. Such an injection molding apparatus has the same effect as the above-described method since the supercritical fluid can be contained in a portion other than the flow front of the resin to obtain an effect such as an internal foam.
[0033]
Injection molding apparatus as another aspect of the present invention is a mold that forms a cavity for filling a thermoplastic resin, a supercritical fluid and a substance dissolved in the supercritical fluid as a counter pressure in the mold. And a mechanism for introducing. Such an injection molding apparatus uses a supercritical fluid and a substance as a counter pressure, and thus has the same effect as the above-described method.
[0034]
An injection molding apparatus as another aspect of the present invention forms a cavity filled with a thermoplastic resin, a mold having an introduction passage communicating with a specific position of the cavity, a supercritical fluid and the supercritical fluid. It is characterized by having a mechanism for introducing the dissolved substance into the cavity through the introduction path. Such an injection molding apparatus can locally modify the surface of a resin molded product by dispersing the substance in the vicinity of a specific position and the surface of the resin.
[0035]
An injection molding apparatus as another aspect of the present invention is a mold that forms a cavity for filling a thermoplastic resin, and is pressed by the thermoplastic resin filled in the cavity, and is pressed by the thermoplastic resin. A stamper having a predetermined pattern formed on one surface thereof and a hole provided at a specific position on a second surface facing the first surface and communicating with the pattern on the first surface; A mechanism for introducing an organic substance dissolved in a fluid into the cavity through the hole of the stamper. By making the pattern a stamper, the wiring circuit can be easily changed. In addition, a desired circuit pattern can be formed by forming a pattern at a specific position.
[0036]
Other objects and further features of the present invention will become apparent from the embodiments described below with reference to the accompanying drawings.
[0037]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 2 shows a flow of plastic electroless plating wiring as one embodiment of the present invention. According to the electroless plating method of the present embodiment, first, the surface of a molded article is entirely or selectively modified by injection molding (step 1100).
[0038]
In one embodiment, a mold is filled with a molten resin, a supercritical fluid, and a substance dissolved therein (organic substance or metal element, here, an organometallic complex) as a flow front as a flow front and a counter pressure. As the supercritical fluid and the substance. Here, the counter pressure is a gas to which a pressure is applied in the mold in a direction opposite to the flow direction of the injected molten resin.
[0039]
Due to the fountain flow phenomenon (fountain effect) of the flowing resin in the mold, the molten resin in the flow front portion forms a surface layer while being pulled by the mold surface. The material that has penetrated into the mold is placed in a layer near the surface in contact with the mold. If the substance has a certain degree of solubility in the supercritical fluid, it can be uniformly dispersed only on the surface of the molded article. Therefore, application to various plastic surface modification technologies can be expected.
[0040]
Thermoplastic resin is not particularly limited, polycarbonate, polymethyl methacrylate, polyether imide, polymethyl pentene, amorphous polyolefin, polytetrafluoroethylene, liquid crystal polymer, styrene resin, polymethyl pentene, polyacetal and the like A mixture of these compounds, a polymer alloy containing these as a main component, or a mixture of these with various fillers can be used.
[0041]
Available supercritical fluids are air, CO ₂ , Butane, pentane, methanol, etc. are optional, but have the same solubility as n-hexane, work as a plasticizer for certain thermoplastic resin materials, and have a proven track record in injection molding and extrusion molding. ₂ Is desirable.
[0042]
Next, the ligand of the organometallic complex disposed on the convex portion of the plastic molded product is removed by heating or a reduction reaction to precipitate metal fine particles (Step 1200). Thereafter, electroless plating is performed (step 1300), and electroless plating is formed only on the protrusions.
[0043]
In the electroless plating wiring of the present embodiment, after the injection molding, a post-treatment by a reduction reaction or heating may be necessary in order to break the bond between the organic portion and the metal portion of the metal complex. However, in the case of certain metal complexes, the bond is broken by the heat of the resin during the contact with the high-temperature molten resin, and metal particles of several nm to several tens μm are automatically deposited, so that post-treatment is not required. The type of the metal complex is arbitrary, but a Pd complex, a Ni complex, a Co complex, a Pt complex and the like are desirable. More specifically, platinum dimethyl (cyclooctadiene), bis (cyclopentadienyl) nickel, bis (acetylacetonate) palladium and the like are desirable. From the viewpoint of not requiring a reduction reaction, Pd complexes and Pt complexes are desirable. After depositing the metal fine particles on the surface of the injection-molded article, any known technique can be used for electroless plating (step 1300), and a detailed description thereof will be omitted. By using the electroless plating layer, for example, an electric wiring pattern can be formed.
[0044]
In the present embodiment, a fine wiring by electroless plating can be formed inexpensively and cleanly by applying a plastic surface modification technique in injection molding, and the flow is shown in FIG. The present invention is characterized by applying the above-described injection molding method, transferring irregularities for forming wiring on the surface of a molded product, and forming plated wiring using the irregularities. As shown in the above, two types of methods can be provided. These two types of methods will be further described with reference to FIGS.
[0045]
FIG. 8 shows a conceptual diagram of an example of the plating wiring method according to the present invention. According to this method, after the metal fine particles 104 serving as catalyst nuclei are deposited on the entire surface of the molded article 136 as shown in FIG. 8A, the electroless plating 138 is laminated on the surface of the molded article as shown in FIG. 8B. Then, as shown in FIG. 8C, by removing the electroless plated portion of the projection by polishing or the like, a wiring pattern in which the electroless plating remains only in the recess can be formed. The method for removing the pattern protrusions in the present invention is arbitrary, but can be removed by polishing or wrapping.
[0046]
FIG. 9 shows a conceptual diagram of another example of the plating wiring method according to the present invention. First, after the metal complex or metal fine particles are arranged in the vicinity of the surface by the above-described injection molding method and a molded product in which irregularities on the surface of the mold or the stamper are transferred is manufactured, in some cases, the organic substance of the metal complex is removed by heat treatment or reduction reaction. Remove completely. Further, after removing the projections on the surface of the molded article, as shown in FIG. 9 (b), the metal fine particles 104 serving as plating nuclei are arranged only in the recesses. By plating, the electroless plating 138 is selectively laminated as shown in FIG. By the methods shown in FIGS. 8 and 9, the object of forming fine wiring by electroless plating on the plastic surface at low cost can be achieved.
[0047]
Step 1100, in another embodiment, dissolves the supercritical fluid and material into the recesses of the mold after filling the mold with the molten resin. The viscosity of the resin in contact with the supercritical fluid decreases, and the organic matter dissolved in the supercritical fluid permeates from the resin surface.
[0048]
Thereafter, by increasing the internal pressure of the resin by holding pressure, mold clamping pressure, or the like, the resin spreads in the concave portion, and a convex portion on which the organic substance is arranged is formed on the surface of the molded body. According to such a method, an organic substance having a certain degree of solubility in a supercritical fluid can be uniformly dispersed and disposed only in the convex portions on the surface of the molded article. Therefore, application to various plastic surface modification technologies can be expected. CO in supercritical fluid ₂ As described above, it works as a plasticizer, so that fine transfer can be easily performed even if the pitch of the irregularities is as fine as submicron order.
[0049]
After injecting the supercritical fluid and the organometallic complex dissolved therein, at least one of the metal complex or the metal fine particles having the ligand of the metal complex removed from the surface of the molten resin is permeated through the concave portion of the mold. As a result, the metal complex or the metal fine particles are selectively arranged only at the portion filled in the concave portion in the mold, that is, only at the convex portion of the plastic molded product. According to this method, it is not necessary to roughen the mold surface, and a metal complex or the like can be selectively arranged in a fine region.
[0050]
Even if the resin does not have a polar group and it is difficult to form a strong electroless plating layer, metal fine particles that serve as catalyst nuclei can be easily embedded in the material. An excellent high-quality electroless plating film can be formed. The wiring process of the electroless plating according to the present embodiment is harmless compared to the conventional method, and the number of pretreatment steps is significantly reduced.
[0051]
The present invention is not limited to the electroless plating method. That is, the present invention can produce a sufficiently useful molded product only by the injection molding method (step 1100). For example, by arranging the metal fine particles on the plastic surface entirely or selectively, it is possible to impart conductivity entirely or locally or to improve the adhesion with a magnetic force. Using such a plastic, for example, a biochip can be easily sealed. That is, by bonding a plastic having fine irregularities serving as a fluid flow path to a glass substrate or the like and generating a magnetic force from the back surface of the glass substrate, the glass substrate and the plastic can be easily sealed.
[0052]
Of course, the organic substance used in the injection molding method (step 1100) of the present invention is not limited to the organometallic complex. For example, by using polypropylene glycol as the organic substance, the surface of a hydrophobic plastic such as polyethylene terephthalate can be selectively hydrophilized. The flow path surface in a biochip made of plastic can be made hydrophilic or water-repellent at the whole or at a local location to make the laminar flow state of the mixed fluid in the chip more efficient, or to remove proteins from the biochip. Analysis can be performed by trapping at a location. Similarly, by using a fluorine compound, a total or selective water-repellent treatment and a reduction in the refractive index can be achieved.
[0053]
Further, the present invention may further include a step of expanding the volume of the cavity and foaming the molten resin after compressing the molten resin by pressure holding and mold clamping. As a result, it is possible to lower the dielectric constant of the material by forming a fine foam cell inside while simultaneously performing the selective modification of the plastic surface. In this case, a foamed state in which the average cell diameter is 30 μm or less and the expansion ratio is 1.5 or more is desirable. This makes it possible to reduce the weight of the plastic molded product, enhance the heat insulating effect, and increase the rigidity-to-weight ratio. Such a molded product is suitable for a high-frequency electric circuit board, a flat antenna such as a MID (Mold Interconnect Device), or a millimeter-wave antenna.
[0054]
Hereinafter, examples of the present invention will be described.
[0055]
【Example】
Embodiment 1
FIG. 1 is a sectional view of a main part of a mold and an injection molding apparatus used in a first embodiment of the present invention. Although the supercritical fluid in the present invention is optional, in the present embodiment, CO 2 is used. ₂ Was used. In the present invention, the substance to be dissolved in the supercritical fluid is arbitrary, but in this embodiment, platinum dimethyl (cyclooctadiene) which is a Pt complex was used.
[0056]
The method of dissolving the substance in the supercritical fluid is arbitrary, but in this embodiment, CO 2 is used. ₂ CO supplied from cylinder 137 ₂ Was brought into a supercritical state by the supercritical fluid generator 101, and then a substance supplied from the storage vessel 102 was dissolved in the supercritical fluid in the mixing tank 103.
[0057]
In the present invention, the pressure and temperature of the supercritical fluid in which the substance is dissolved, and the method of introducing the molten resin into the flow front portion are arbitrary, but in this embodiment, the supercritical CO of 120 ° C. and 10 Mpa is used. ₂ Is introduced into the cavity together with the dissolved substance as a counter pressure for applying pressure opposite to the flow direction of the injected thermoplastic resin, and the flow front portion of the molten resin is impregnated in the plasticizing cylinder 140. The magnitude of the pressure of the counter pressure is lower than the resin pressure at the time of filling the resin entering from the spool. The resin pressure in this case means the actual resin pressure in the mold, but is not usually monitored. Usually, the resin pressure refers to the pressure of a molding machine that extrudes a screw. The latter has a force of about 100 to 200 MPa, which is much larger than the counter pressure, and the former has a force of about 20 MPa. Assuming that the pressure of the counter pressure is defined, it is sufficient that the pressure when the gas actually enters the mold is in a supercritical state (CO ₂ If so, about 7 MPa or more). In addition, the upper limit is lower than the pressure at which the resin can be filled, which depends on the material and the molding conditions. In the present invention, a method of introducing a supercritical fluid and a substance dissolved therein into the mold cavity 117 as a counter pressure is optional, but in this embodiment, the electromagnetic valve 111 is closed at the same time as the injection filling is started after the cavity 117 is closed. Was introduced from the mixing tank 103 through the channel 112.
[0058]
In the present invention, the method for infiltrating the supercritical fluid and the substance dissolved therein into the flow front portion of the molten resin after the plasticization measurement in the plasticizing cylinder 140 is optional, but the method in the present embodiment is shown in FIGS. This will be described with reference to FIG. The plasticization measurement is a process of plasticizing the resin pellets in a short time by rotating the screw, making the amount to be charged and injected in the next shot into a constant volume, and storing the amount before the screw.
[0059]
First, when the screw 107 rotates in the direction of the arrow in FIG. 7A in the plasticizing cylinder 140 whose temperature is controlled by the band heater 139, the thermoplastic resin pellet 135 is supplied from the hopper 121 and plasticized. While being pushed forward of the screw 107, the screw 107 retreats accordingly. When the screw 107 stops retreating at the measuring position, the molten resin 116 is plasticized and measured between the screw 107 and the shut-off nozzle 105. The shut-off nozzle 105 is a mechanism that opens and closes a flow path between the mold and the cylinder that prevents molten resin from entering the mold even when the internal pressure of the cylinder increases. The screw 107 has a function of plasticizing and melting the pellet and a function of injecting the pellet (also called an in-line screw). Then, after the plasticization measurement is completed, as shown in FIG. 7B, the screw 107 is retracted by suck-back to reduce the pressure of the front portion of the molten resin, and between the shut-off nozzle 105 and the screw 107. The supercritical fluid and its dissolved product were introduced by opening the electromagnetic valve 108 from the supply port 106 of the provided mixture. Further, after the solenoid valve was closed, the screw 107 was pressurized and advanced at a pressure of 10 Mpa, so that the supercritical fluid and the melt thereof permeated the flow front portion of the molten resin. Thereafter, injection filling was performed immediately.
[0060]
In the present invention, any thermoplastic resin can be used, but in this example, polyetherimide (Ultem 1010 manufactured by GE Plastics) having a glass transition temperature of about 230 ° C. was used. The temperature of the plasticizing cylinder was 380 ° C.
[0061]
In the injection molding method of the present invention, there is no restriction other than impregnating the supercritical fluid and its dissolved substance into the flow front as the flow front of the molten resin, but in the present embodiment, the cavity is filled at the time of filling. Injection compression molding in which mold compression is performed immediately after opening and filling was used. Then, a mold sealing mechanism in which the supercritical fluid does not leak even when the cavity is opened with the supercritical fluid introduced as a counter pressure was devised. Due to the molding method and the mold structure, fine transfer can be performed even for a difficult-to-form material or a thin-walled product in which a resin is difficult to flow with a high glass transition temperature.
[0062]
Next, the molding method in this embodiment will be described in detail with reference to FIGS. FIGS. 4 and 5 are enlarged views of a main part of the mold in the part A of FIG. In this embodiment, a plate-shaped product having a product shape of 50 mm long × 60 mm wide × 0.5 mm thick was formed by taking two pieces. The temperature of the fixed mold 143 and the movable mold 129 of the mold 142 is controlled by cooling water flowing through a temperature control circuit (not shown), but the temperature was controlled at 140 ° C. in the present embodiment.
[0063]
As shown in FIG. 1, each cavity 117 in the mold 142 is vertically divided around a spool 119, and a rectangular stamper 118 corresponding to each cavity 117 is provided on the fixed mold 143. The surface of the stamper 118 is provided with a line and space uneven pattern. The stamper was manufactured as follows. First, after forming concavities and convexities on a silicon substrate by photolithography using a resist, Ni having a thickness of 0.4 mm was formed on the resist pattern by electroless plating and electrolytic plating. Then, Ni was peeled off from the resist and processed into a stamper shape.
[0064]
As shown in FIG. 4, one side of the stamper 118 on the spool 119 side is mechanically fixed to a fixed mold 143 by a stamper holding claw 141, and the other three sides are fixed molds by vacuum suction from the vacuum groove 131. 143. On the stamper holding claw 141, a runner groove 130 connected to the spool 119 and through which the molten resin passes is provided. The movable mold 129 facing the runner groove 130 is provided with a protrusion 131 that fits inside the groove 130, so that even if the cavity 117 is opened to some extent, the filling resin does not protrude from the runner groove 130.
[0065]
On the movable mold 129 facing the stamper 118, an outer peripheral frame 123 for regulating the outer peripheral portion of the product is installed so as to be independently driven in the cavity opening and closing direction. The outer peripheral frame 123 is stepped, and the edge 123A regulates the outer peripheral portion of the product. On one side of the outer peripheral frame 123 on the spool side, which is the filling start direction, there is provided a groove 132 connected to the runner groove 130. After passing through the gate 144, the molten resin is filled into the cavity 117 through the groove 132.
[0066]
In this embodiment, the mold clamping pressure was controlled such that the cavity thickness T was 3.0 mm as shown in FIG. 5 when filling the molten resin, and the opening amount was constant during the filling. At the same time as the start of the filling, the supercritical fluid and its dissolved product were introduced into the mold and the cavity 117 from the flow channel 112 at the pressure indicated by an arrow 125 in FIG. At the same time, the solenoid valve 113 in FIG. 1 is opened, and only the supercritical fluid is introduced into the mold through the flow path 114. Was pressurized to bring the supercritical fluid pressures 125 and 126 into equilibrium. Since springs 128 and 127 are provided on the rear surfaces of the movable abutting ring 122 and the outer peripheral frame 123, the parts are abutted against the fixed mold 143 by the spring force. Since the sealing property is maintained even when the mold is opened by this mechanism, the high-pressure supercritical fluid does not leak from the mold, and the filled resin does not protrude from the outer peripheral frame 123 that regulates the outer periphery of the product.
[0067]
The supercritical fluid and its melt introduced at a pressure of 125 as counter pressure pass through the passage hole 124 in the outer peripheral frame 123 and the clearance t between the stamper 118 and the outer peripheral frame 123 and are filled in the cavity 117. In this embodiment, the clearance t was 10 μm.
[0068]
The molten resin having the flow front portion impregnated with the supercritical fluid and its melted material passes through the spool 119 as shown in FIG. 5 by the screw 107 being advanced immediately after the shut-off nozzle 105 is opened in FIG. 117 is filled. FIG. 6 schematically shows the state of the resin being filled. At the flow front 133 of the molten resin 116 flowing in the direction of the arrow 134, the supercritical fluid and the substance 115 dissolved therein due to the fountain flow phenomenon are stamped by the stamper 118 and the movable mold 129. On the wall. The dissolved substance of the supercritical fluid previously impregnated in the resin and the same substance introduced as a counter pressure are selectively disposed on the surface of the molded article with the same effect.
[0069]
When the supercritical fluid is infiltrated in the filling resin in advance, the supercritical fluid or pressurized CO ₂ By introducing as a counter pressure, the pressure reduction of the supercritical fluid inside the resin and the accompanying foaming can be suppressed. Therefore, even in the case where only the front portion of the molten resin is impregnated with the supercritical fluid and its dissolved substance at the time of plasticization, it is desirable to introduce the counter pressure of only the supercritical fluid into the cavity. In the case where the counter pressure is not used, heat insulation can also be achieved by forming a low heat conductive material such as polyimide on the mold surface or the release surface of the stamper, so that a rise in resin viscosity and a decrease in pressure of the supercritical fluid can be similarly suppressed. desirable.
[0070]
In addition, in this embodiment, the concavo-convex pattern of the stamper 118 schematically shown in FIG. 6 has a width W: 2 μm, W2: 5 μm, and a depth D: 30 μm. In the present embodiment, it is considered that a pattern having a high aspect ratio cannot be sufficiently transferred at the time of injection filling as shown in FIG. 6, but immediately after filling, the cavity opening amount T3.0 mm is reduced to a product thickness of 0.5 mm. By compressing with a mold clamping pressure of 40 tons, it was possible to transfer completely.
[0071]
In the molding method of the present embodiment, by opening the cavity at the time of filling, the flow resistance of the molten resin in the mold can be reduced, and the flow length in the cavity can be shortened. Further, by compressing the volume of the cavity immediately after the filling, the pressure of the supercritical fluid reduced during the injection filling can be increased again, and the surface viscosity of the resin can be kept low. Further, the supercritical fluid introduced by the counter pressure which easily remains in the fine pattern can be made to permeate into the molten resin. By these methods, fine transfer can be performed even on a difficult-to-mold material or a difficult-to-mold structure, and the pressure distribution in the cavity becomes uniform.
[0072]
In this embodiment, after the injection and compression, the solenoid valves 145 and 136 in FIG. ₂ Was leaked and the molten resin was solidified in the mold, and the mold was opened to take out the product. It was confirmed that on the surface of the molded article produced in this example, a Pt complex which was dissolved in a supercritical fluid and Pt fine particles from which an organic substance was removed from the complex were arranged. It was also confirmed that the melt was hardly contained in the center of the molded article.
[0073]
In the present invention, after disposing a supercritical fluid solution such as a metal complex on the surface of the molded article by the above method, post-treatment such as heating or reduction reaction may be performed, but in this embodiment, electroless plating is performed. No post-processing was performed by then.
[0074]
In this example, electroless copper plating was performed on the molded article produced by the above-mentioned injection molding method by the following method. First, it was placed in a container containing an aqueous solution for electroless copper plating ("OPC700A" manufactured by Okuno Pharmaceutical Industries, 100 ml / liter + "OPC700B" manufactured by Okuno Pharmaceutical Industries, 100 ml / liter) and stirred at room temperature for 60 minutes to perform copper plating. After further washing, an aqueous solution for electroless copper plating ("OPC Copper T1" manufactured by Okuno Pharmaceutical Co., Ltd. 60 ml / liter + "OPC Copper T2" manufactured by Okuno Pharmaceutical Co., Ltd. 12 ml / liter + "OPC Copper T3" manufactured by Okuno Pharmaceutical Co., Ltd. 100 ml) / Liter) and stirred at 60 ° C. for 120 minutes and air to perform copper plating. After ultrasonic cleaning with pure water and methanol, a 10 μm-thick copper plating film was formed on the entire surface of the molded product. In addition, it was confirmed that the plating film had a uniform thickness, had no blistering, and had a practically acceptable adhesion strength even in a peel test.
[0075]
Further, as shown in the schematic view of FIG. 8, the surface of the pattern-formed surface of the molded article shown in FIG. 8B is polished by 20 μm to remove the projections as shown in FIG. A remaining wiring pattern was formed. It was confirmed that in the molded article in this example, wiring of 2 μm in width of electroless copper plating was formed without loss. It was also confirmed that the insulation between adjacent wirings was good.
[0076]
Embodiment 2
The wiring by injection molding and electroless plating was performed in the same manner as in Example 1, except that the electroless plating after the production of the molded article was performed as shown in FIG. It was confirmed that in the molded article in this example, wiring of 2 μm in width of electroless copper plating was formed without loss. It was also confirmed that the insulation between adjacent wirings was good.
[0077]
Embodiment 3
Supercritical CO is added to the molten resin except at the flow front. ₂ And injection molding was performed in the same manner as in Example 1 except that the inside of the molded article was made into a foam. In this example, an internal foam was produced as follows.
[0078]
First, by opening the solenoid valve 110 from the supercritical fluid inlet 109 shown in FIG. ₂ Is introduced into the vent part 120 of the screw 107, and the supercritical CO in which the metal complex is not dissolved except for the front part is introduced. ₂ Was impregnated in the molten resin. The transfer by injection filling and injection compression was performed in the same manner as in Example 1, and then CO ₂ Was released to the atmosphere, the high-pressure mold clamping force was reduced to 5 tons, and the inside was foamed to obtain a molded product. The supercritical fluid introduced into the mold was released to the atmosphere by opening the solenoid valve 136 at the same time as foaming.
[0079]
In the molded article of the present example, the pressure distribution in the cavity was made uniform by the effect of the above-mentioned injection compression, so that a uniform fine foam was obtained over the entire surface. In addition, the molded article in this example was subjected to electroless plating in the same manner as in Example 1 to produce a wiring pattern, and it was confirmed that the wiring was formed without loss. It was also confirmed that the insulation between adjacent wirings was good.
(Comparative example)
Injection molding and electroless plating were performed in the same manner as in Example 1 except that the Pt complex, which was a dissolved material, was not dissolved in the supercritical fluid. In the molded article of this comparative example, electroless plating could not be performed.
[0080]
Embodiment 4
FIG. 10 shows a cross-sectional structural view of a main part of a mold and a molding apparatus used in this example. Although the supercritical fluid in the present invention is optional, in the present embodiment, CO 2 is used. ₂ Was used. In the present invention, the substance to be dissolved in the supercritical fluid is arbitrary, but in this example, bis (acetylacetonate) palladium which is a Pd complex was used.
[0081]
The method of dissolving the substance in the supercritical fluid is arbitrary, but in this embodiment, CO 2 is used. ₂ CO supplied from cylinder 201 ₂ Was brought into a supercritical state by the supercritical fluid generator 202, and then an organic substance to be dissolved in the supercritical fluid supplied from the storage container 204 was dissolved in the mixing tank 203 so as to have a predetermined concentration. In this example, the mixing tank 203 was maintained at 100 ° C. and 12 MPa atmosphere.
[0082]
In the present invention, the method of introducing the supercritical fluid in which the organic substance is dissolved into the inside of the mold is arbitrary, but in this embodiment, the fine flow in the fixed mold 214 through the flow path 216 by opening the electromagnetic valve 207 is performed. The fluid was injected into the cavity 205 formed by the fixed mold 214 and the movable mold 215 from the path 206. In the present embodiment, the diameter of the fine channel 206 in the fixed mold 214 was Φ0.3 mm.
[0083]
Next, the injection molding method in this embodiment will be described in detail with reference to FIGS. First, a known method is used for plasticization and filling. In FIG. 10, the resin pellets (not shown) filled in the plasticizing cylinder 220 from the hopper 217 via the band heater 218 by the rotation of the screw 219 are plasticized and melted and weighed in front of the screw 219. As the internal pressure in front of the screw 219 increases, the screw 219 retreats. At the time of injection, the molten resin measured by the advance of the screw 219 is filled into the cavity 205 of the mold. The cavity 205 is formed by a fixed mold 214 and a movable mold 215 whose temperature is controlled by a temperature control circuit (not shown), and the molten resin is filled through a nozzle 221 and a mold spool 222.
[0084]
In the present invention, any thermoplastic resin that can be used is arbitrary. In this embodiment, polyetherimide having a glass transition temperature of about 230 ° C. (Ultem 1010 manufactured by GE Plastics Co., Ltd.) was used. In this example, the temperature of the plasticizing cylinder was 380 ° C. The medium temperature in the temperature control circuit flowing through the mold was set to 125 ° C.
[0085]
The surface of the fixed mold 214 in this embodiment is provided with irregularities communicating with the flow path 206. In the present invention, the irregular shape of the mold surface and its pitch and depth are arbitrary, but in the present embodiment, a line and space groove pattern 209 having a constant depth and a random pitch and width is provided. The groove had a depth of 2 mm, a width of 0.9 mm, and a minimum pitch of 0.6 mm.
[0086]
FIG. 11 is an enlarged view of a portion C in FIG. 10 of the mold cavity 205 provided with the groove pattern 209. Hereinafter, a method of filling the groove 209 with resin will be described with reference to FIG. The space of the cavity 205 before filling in FIG. 11A is filled with the molten resin 212 as shown in FIG. 11B. At this time, since the internal pressure of the resin is not sufficiently high in the first filling, the inside of the groove 209 of the mold cannot be sufficiently filled, and the projection 210 is formed. In this unfilled state, the supercritical fluid 208 in which the organometallic complex was dissolved was injected into the groove 209. At this time, the supercritical fluid and its melt were controlled so as not to leak from the groove 209 by the resin internal pressure and the mold clamping pressure. Supercritical CO ₂ When the resin comes into contact with the molten resin, the convex portion 210 of the resin in the groove 209 is softened, so that the metal complex 213 easily permeates into the resin. Further, as shown in FIG. 11D, the resin is almost completely filled in the groove 209 by increasing the holding pressure and the mold clamping pressure. Thereby, the organometallic complex 213 is arranged only on the surface of the convex portion 210 of the molded body.
[0087]
In the present invention, after dissolving a supercritical fluid such as a metal complex on the surface of the molded article by the above method, post-treatment such as heating or reduction reaction may be performed. For 1 hour to completely remove the ligand of the organometallic complex. In this example, the molded article produced by the injection molding method was subjected to electroless copper plating by the following method. First, it was placed in a container containing an aqueous solution for electroless copper plating ("OPC700A" manufactured by Okuno Pharmaceutical Industries, 100 ml / liter + "OPC700B" manufactured by Okuno Pharmaceutical Industries, 100 ml / liter) and stirred at room temperature for 60 minutes to perform copper plating. After further washing, an aqueous solution for electroless copper plating ("OPC Copper T1" manufactured by Okuno Pharmaceutical Co., Ltd. 60 ml / liter + "OPC Copper T2" manufactured by Okuno Pharmaceutical Co., Ltd. 12 ml / liter + "OPC Copper T3" manufactured by Okuno Pharmaceutical Co., Ltd. 100 ml) / Liter) and stirred at 60 ° C. for 120 minutes and air to perform copper plating. After ultrasonic cleaning with pure water and methanol, a 10 μm-thick copper plating film was formed on the entire surface of the molded product. In addition, it was confirmed that the plating film had a uniform thickness, had no blistering, and had a practically acceptable adhesion strength even in a peel test. In addition, it was confirmed by a resistance measurement conducted to the wiring that a low-resistance wiring was formed without disconnection. It was confirmed that the insulation between adjacent wirings was also good.
[0088]
Embodiment 5
In this example, injection molding was performed using a molding apparatus similar to that of Example 4 except that the mold shown in FIG. 12 in which the concave and convex pattern in the mold was provided on a Ni stamper was used. The mold includes a fixed mold 214 and a movable mold 215, and a Ni stamper 228 is held on the movable mold 215 by a stamper holding frame 225. The stamper holding frame 225 has a frame shape, and is sealed by the fixed mold 214 and the mold to form a plate-like cavity 205.
[0089]
The supercritical fluid and the organic substance dissolved therein are introduced from the channel 216 to the surface of the stamper.
[0090]
Next, a stamper shape and a molding method according to the present embodiment will be described with reference to FIGS. 13A and 13B which are enlarged views of a portion D shown in FIG.
[0091]
The stamper 228 in this embodiment was manufactured as follows. First, patterning was performed on a resist provided on a silicon substrate by photolithography, and dry etching was performed using the resist as a mask to produce a silicon mold having unevenness with a high aspect ratio. Next, a Ni stamper 228 having a thickness T of 0.3 mm was manufactured by electroforming in the same manner as in the stamper manufacturing process of the optical disk. The pattern width L in the groove 209 of the stamper 228 was 0.05 mm, and the depth d was 0.1 mm. Then, a hole 226 having a diameter of 0.1 mm and a depth of 0.2 mm was formed at an appropriate position from the back surface of the stamper 228 by machining. The hole 226 is provided so as to communicate with an isolated portion of each groove 209. For example, in the groove group 229, each groove communicates with the same hole 226. The hole 226 can form a finer and deeper hole by laser processing, and can cope with miniaturization of a pattern. Even if the pattern width L is on the order of submicrons, the depth of the hole 226 is the same, and the diameter can be formed to Φ10 μm or less.
[0092]
The molding was performed as follows. After the injection in the same manner as in Example 4, a supercritical fluid in which the metal complex was dissolved was injected into the mold from the channel 216. As shown in FIG. 13B, the supercritical fluid pushes up the stamper 228 and the molten resin 212 having a high elasticity, creates a slight clearance 227 on the back surface of the stamper, and penetrates through the resin protrusion 210 through the hole 226. A fine slit may be formed on the die surface on the back surface of the stamper, and the slit may be used as a passage for the supercritical fluid. Thereafter, the pressure of the supercritical fluid was reduced to increase the holding pressure of the resin in the same manner as in Example 1, whereby the stamper 228 and the movable mold 215 were brought into close contact with each other, and the transfer at the projection 210 and the injection of the metal complex were completed.
[0093]
According to the forming method of the present embodiment, the wiring circuit can be easily changed by forming the wiring forming pattern into a stamper. Further, by reducing the thickness of the stamper, the curved surface portion of the mold can also hold the stamper, thereby facilitating the formation of a three-dimensional circuit. In addition, a fine patterning technique such as photolithography can be used for producing a stamper pattern, so that a fine pattern on the order of submicrons can be formed.
[0094]
Although the embodiments of the present invention have been described above, the present invention can be variously modified and changed within the scope of the gist. For example, in FIG. 11, the groove 209 is filled with a resin, and as a result, a protrusion is formed in the molded product, and the surface of the protrusion is modified, but as shown in FIG. The surface of the molded article without irregularities can be selectively modified. Here, FIG. 14 is a modification of the embodiment shown in FIG. In FIG. 14, a groove 209a of a mold including a fixed mold 214a and a movable mold 215a is arranged at a specific position of a flat molten resin (or molded product) 212a. By introducing a supercritical fluid in which the metal complex is dissolved as shown by the arrow of the groove 209a and adjusting (for example, lowering) the pressure and / or temperature during injection molding, the metal complex is locally applied to the surface of the molded article. Can be placed.
[0095]
【The invention's effect】
According to one aspect of the present invention, a plastic surface can be modified without roughening the surface of a molded product or a mold during injection molding. For example, the adhesion of electroless plating on the plastic surface during injection molding can be improved. Further, fine wiring can be formed on the plastic surface at low cost by electroless plating. Further, according to another aspect of the present invention, it is possible to provide a plastic molded article whose surface is selectively modified without roughening the surface during injection molding, and a method and an apparatus for manufacturing the same.
[Brief description of the drawings]
FIG. 1 is a sectional view of a main part of an injection molding apparatus according to an embodiment of the present invention.
FIG. 2 is a flowchart of a method for electroless plating a plastic surface according to the present invention.
FIG. 3 is a flowchart of a method of finely wiring a plastic surface in the method shown in FIG. 2;
FIG. 4 is an enlarged view of a portion A shown in FIG.
FIG. 5 is a sectional view for explaining the operation of the structure shown in FIG. 4;
FIG. 6 is an enlarged schematic diagram for explaining a state of a flow front at the time of injection filling of a portion B shown in FIG. 5;
FIG. 7 is an enlarged sectional view of an injection mechanism of the injection molding apparatus shown in FIG.
8 is a partially enlarged cross-sectional view of a mold for explaining an example of the electroless plating method shown in FIG.
FIG. 9 is a partially enlarged sectional view of a metal mold for explaining another example of the electroless plating method shown in FIG.
FIG. 10 is a sectional view of an injection molding apparatus according to another embodiment of the present invention.
11 is a partially enlarged sectional view of the injection molding apparatus shown in FIG.
FIG. 12 is a partial sectional view of an injection molding apparatus according to yet another embodiment of the present invention.
FIG. 13 is a partially enlarged sectional view of the injection molding apparatus shown in FIG.
FIG. 14 is a partial sectional view of a mold showing a modification of the embodiment shown in FIG. 11;
FIG. 15 is a flowchart showing a conventional electroless plating method.
FIG. 16 is a flowchart for explaining a conventional plating wiring method.
[Explanation of symbols]
101 Supercritical fluid generator
102 storage container
103 mixing tank
104 metal fine particles
105 Shut-off nozzle
112 channel
115 Supercritical fluid dissolved substance
117 cavity
133 Flow Front
138 Electroless plating layer
205 cavities
206 micro channel
208 Supercritical fluid
209 groove
210 convex part
212 molten resin
213 Organometallic complex
214 fixed mold
215 Movable mold
220 Plasticizing cylinder
226 holes
228 Stamper

Claims (27)

A molded article made of a thermoplastic resin,
The molded article contains an organic substance different from the thermoplastic resin inside,
The molded article, wherein the organic substance is disposed near and on the surface of the molded article. The molded article according to claim 1, wherein the organic substance is provided at a specific position on the surface. A molded article made of a thermoplastic resin, wherein the molded article includes a metal element therein,
The molded article, wherein the metal element is disposed near and on the surface of the molded article. The molded article according to claim 3, wherein the metal element is provided at a specific position on the surface. The molded article according to claim 3, further comprising a plating layer formed by using the metal element as a nucleus. The molded product according to claim 5, wherein the plating layer forms an electric wiring pattern. The molded article according to any one of claims 1 to 6, further comprising a foam inside the thermoplastic resin. A method for producing a molded article by injection molding a thermoplastic resin,
Injecting the thermoplastic resin, a supercritical fluid and a substance dissolved in the supercritical fluid into a mold, and modifying the surface of the molded article. 9. The method according to claim 8, wherein the injecting step includes introducing the supercritical fluid and the substance into a flow front as a flow front of the thermoplastic resin during injection filling. 9. The method as set forth in claim 8, wherein in the injection step, the supercritical fluid and the substance are introduced into the mold as a counter pressure for applying a pressure opposite to a flow direction of the injected thermoplastic resin. The described method. 9. The method according to claim 8, wherein the injecting step includes the step of injecting the thermoplastic resin into the thermoplastic resin at the time of plasticization and measurement for plasticizing and measuring the supercritical fluid and the substance. The injection step includes:
A step of introducing the supercritical fluid in which the substance does not dissolve into the thermoplastic resin except for the flow front as a flow front portion of the thermoplastic resin,
Forming a foam inside the thermoplastic resin injected into the mold using the supercritical fluid. The injection step includes:
Filling the mold with the thermoplastic resin,
Introducing the supercritical fluid and the substance to a specific location within the mold. 14. The method according to claim 13, further comprising the step of placing the substance in the thermoplastic resin at the specific location by adjusting the pressure and / or temperature of the mold. The method according to any one of claims 8 to 14, wherein the substance is an organometallic complex. The said substance is an organometallic complex, The said method further has the process of forming the plating layer in the site | part which modified the surface of the said molded article by electroless plating. The described method. The molded body includes an uneven portion on the surface,
17. The method according to claim 16, further comprising a step of removing the projection after the plating layer forming step. The molded body includes an uneven portion on the surface,
17. The method according to claim 16, further comprising a step of removing a convex portion of the portion before the step of forming the plating layer. The substance is an organometallic complex,
The method partially modifies the molded article surface,
The method according to claim 13, wherein the method further comprises a step of forming a pattern comprising a plating layer by providing a plating layer on a modified portion of the surface of the molded article by electroless plating. Compressing the thermoplastic resin after the injecting step,
The method according to claim 8, further comprising, after the compression step, increasing the volume of the cavity of the mold to expand the thermoplastic resin. The injection step is a step using a stamper pressed against the filled thermoplastic resin,
The stamper has a first surface pressed by the thermoplastic resin and a second surface facing the first surface, a predetermined pattern is formed on the first surface, and the second surface is identified. The method according to claim 13 or 14, wherein a hole communicating with the pattern on the first surface is provided at the position (1). A mold used to manufacture a molded article by injection molding a thermoplastic resin,
A mechanism for introducing a supercritical fluid and a substance dissolved in the supercritical fluid into the mold as a counter pressure for applying a pressure opposite to the flow direction of the thermoplastic resin injected into the mold. A mold characterized by having. A mold used to manufacture a molded article by injection molding a thermoplastic resin,
A concave or convex portion is formed at a specific position on the cavity forming surface of the mold,
A mold, characterized in that an injection passage for injecting a supercritical fluid and a substance dissolved in the supercritical fluid is connected to the concave portion or the convex portion. A mold for forming a cavity for filling a thermoplastic resin,
A plasticizing cylinder for introducing the thermoplastic resin into the cavity of the mold,
Injection having a mechanism for introducing a supercritical fluid and a substance dissolved in the supercritical fluid into the plasticizing cylinder and including the supercritical fluid and the substance at least in a flow front as a flow front end of the thermoplastic resin. Molding equipment. A mold for forming a cavity for filling a thermoplastic resin,
An injection molding apparatus comprising a supercritical fluid and a mechanism for introducing a substance dissolved in the supercritical fluid into the mold as counter pressure. Forming a cavity to be filled with a thermoplastic resin, a mold having an introduction path communicating with a specific position of the cavity,
An injection molding apparatus having a mechanism for introducing a supercritical fluid and a substance dissolved in the supercritical fluid into the cavity through the introduction path. A mold for forming a cavity for filling a thermoplastic resin,
A predetermined pattern is formed on a first surface pressed by the thermoplastic resin filled in the cavity, and a predetermined pattern is formed on a first surface pressed by the thermoplastic resin, and the pattern is formed on a second surface opposite to the first surface. A stamper provided with a communicating hole,
A mechanism for introducing an organic substance dissolved in a supercritical fluid into the cavity through the hole of the stamper.

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