JP2002001859A - Conductive plastic molding and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a conductive plastic molding and a method for manufacturing the same capable of recovering a plastic material in a high efficiency by easily separating the material from the other material at a recycling time of the plastic molding. SOLUTION: A resin shield 16 formed with a conductive layer 18 for giving conductivity is adhered to the plastic molding 12 of an electric non-conductor via an adhesion layer 14 for developing releasability by heating.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a conductive plastic molded article and a method for producing the same, and
TECHNICAL FIELD The present invention relates to a plastic molded product that can be easily separated from a member formed only of a plastic material constituting the molded product at the time of recycling to facilitate regeneration of each material, and a method of manufacturing the molded product.

[0002]

2. Description of the Related Art Various electronic devices such as a computer, a word processor, and a sequencer incorporating a microcomputer as a control element may malfunction due to disturbance such as electromagnetic waves entering the device from the outside. Are known. In addition, these electronic devices often emit electromagnetic waves to the outside of the device molded body during operation and become a harmful noise source in many cases. This type of electromagnetic interference (EMI),
In order to protect the electronic device from interference by lower frequency radio waves (RFI) and to prevent leakage of electromagnetic waves from the device to the outside, a so-called electromagnetic shield is generally applied to the molded article of the device. Is done.

As the shield, a metal plating layer is deposited by dry plating or wet plating on the entire or inner surface of a plastic electronic device molded article which is lightweight and can exhibit high design properties, or a conductive filler is applied. The formation of a conductive layer, for example, by applying a conductive paint contained therein, is generally performed. With these shields, as described above, external electromagnetic waves can be shielded to prevent intrusion into the device, and leakage of internal electromagnetic waves can be effectively prevented.

[0004]

[Problems to be Solved by the Invention] By the way, in April 2001
The “Home Appliance Recycling Law” is scheduled to go into effect this month,
From the viewpoint of efficient treatment of various industrial wastes and effective utilization of global resources, a method for efficiently regenerating all industrial products, particularly, material regeneration (material recycling) is being sought. For material recycling of a plastic member represented by the electronic device molded body, a method of pulverizing the plastic member, melting it by heating, and regenerating it into various products is generally adopted. However, in this material recycling, it is difficult to physically separate the conductive layer (metal component) formed in close contact with the plastic electronic device molded body. The conductive layer forming material intervenes as a contaminant in the product, which not only impairs physical properties such as mechanical strength of the obtained product and prevents effective regeneration, but also makes it impossible to effectively recover the metal. Shortcomings are noted.

[0005] Therefore, as another regenerating method, after the metal forming the conductive layer is dissolved and removed with a chemical agent such as an acid in advance,
A method of crushing the plastic member is considered,
In this case, a long time is required for dissolving the conductive layer, and a wastewater treatment of the dissolving solution is required, so that the regeneration cost is increased and the productivity is reduced. When recovering the metal, it is necessary to further perform a chemical or electrochemical reduction treatment.
In the case of treatment in a gasification melting furnace or a blast furnace, plastic can be effectively used as a heat source or a chemical component for reduction, and metal can be recovered.
Since it has only a very small thickness of about 3 μm, it has a disadvantage that the regeneration rate of the substance cannot be set sufficiently high as a whole.

[0006]

SUMMARY OF THE INVENTION The present invention has been proposed in view of the above-mentioned problems that appear when materially recovering constituent materials from the waste of conductive plastic molded articles, and to solve the problems appropriately. Accordingly, it is an object of the present invention to provide a conductive plastic molded article capable of easily separating a plastic material from other materials at the time of a regeneration treatment and recovering the plastic material with high efficiency, and a method of manufacturing the same.

[0007]

SUMMARY OF THE INVENTION In order to overcome the above-mentioned problems and achieve the intended object, a conductive plastic molded article of the present invention is a plastic molded article formed into a required shape from an electrically non-conductive plastic raw material. And, a conductive layer for imparting conductivity is formed, a resin shield body laminated on the plastic molded body, interposed between the plastic molded body and the resin shield body, both members (12, 16) It is characterized by comprising an adhesive layer that adheres and exhibits releasability when heated.

In order to overcome the above-mentioned problems and achieve the intended object, a method of manufacturing a conductive plastic molded article according to another invention of the present application is to produce a plastic molded article of a required shape from an electrically non-conductive plastic raw material. After forming a resin body that can be adhered to the plastic molded body by molding and forming a sheet-like material made of plastic raw material, a conductive layer is formed on a required surface of the resin body to be made conductive, and a resin shield is formed. A body is formed, and then an adhesive layer is formed by applying an adhesive that exhibits releasability by heating to a portion to be attached between the plastic molded body and the resin shield body, and the plastic molding is performed by the adhesive layer. The body and the resin shield body are bonded to each other.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, a conductive plastic molded article and a method for producing the same according to the present invention will be described below with reference to the accompanying drawings by way of preferred embodiments.

As shown in FIGS. 1 and 2, a conductive plastic molded article 10 according to a preferred embodiment of the present invention is formed of, for example, various thermoplastic resins which can be suitably used for a notebook personal computer. Plastic molded body 12 having the following strength, a resin shield body 16 laminated on the plastic molded body 12, and a plastic molded body 12 and a resin shield body interposed between the plastic molded body 12 and the resin shield body 16. And an adhesive layer 14 for adhering the body 16. The resin shield body 16 includes a resin body 15 serving as a base material thereof,
And a conductive layer 18 formed on a required surface of the substrate.

Further, as shown in FIG. 3, a method for manufacturing a conductive plastic molded product according to a preferred embodiment of the present invention includes a molded body manufacturing step S1, a resin shield body manufacturing step S2, an adhesive layer providing step S3, and an assembling step. It is largely divided into S4 and the final step S5.

The molded article producing step S1 is a step of producing a plastic molded article 12 having a required shape, and is generally known as injection molding, extrusion molding, blow molding, vacuum molding, press molding, transfer molding or other molding. Any of the methods can be adopted and is suitably selected as appropriate. In particular, in the case of the present invention, injection molding, which has high productivity and can cope with molding of a molded article or the like which requires high molding accuracy, is preferable.

As described above, the plastic molded body 12 has a precision moldability as a molded body for electronic equipment and an adhesive property with the adhesive layer 14, and has various heat properties which do not cause a physical property deterioration when melting in a recycling process. A plastic resin can be suitably used. For example, ABS resin, PC resin, PP
Polymer alloys such as O resin, PP resin, PS resin, PEI resin, PPS resin, PET resin, PBT resin, PES resin, PA resin, and PC / ABS resin. In addition, as a form of reuse, for example, if it is used as a filler after pulverization of waste, not only the above-mentioned thermoplastic resin but also various thermosetting resins can be adopted.

Various fillers may be mixed for the purpose of improving the mechanical strength of the plastic molded body 12 and imparting flame retardancy. Examples of the filler include aramid fiber, carbon fiber, glass fiber, calcium carbonate, silicon oxide, barium sulfate, aluminum hydroxide, and magnesium hydroxide.

The resin shield manufacturing step S2 is a step of manufacturing a resin shield 16 to be laminated on the plastic molded body 12 separately from the molded body manufacturing step S1. This step S2 includes the resin body molding step S21 and the conductive layer providing step S22.

The resin body molding step S21 is a step of molding a plastic material such as a predetermined thermoplastic resin capable of forming the conductive layer 18 in close contact with the inner surface of the plastic molded body 12 in a shape capable of being laminated. is there. The resin body 15 molded at this stage serves as a base material for forming the conductive layer 18 exhibiting an electromagnetic shielding effect, and unlike the plastic molded body 12, does not require mechanical strength. It is formed with a thickness of 20% or less of the body 12.

As a specific method for molding the resin body 15, as described above, since it is necessary to form a thin resin body 15 having a thickness of 20% or less of the plastic molded body 12, first, a suitable plastic raw material is formed to a required thickness. Forming a sheet,
Next, the sheet is formed into a shape that can be laminated inside the plastic molded body 12 by a method such as vacuum molding. In addition, depending on the shape, extrusion molding or injection molding with high mass productivity, ordinary press molding, or the like can be employed.

The plastic raw material suitably used for the production of the resin body 15 is substantially the same as the constituent material of the plastic molded body 12 described above. In particular, a resin which can be easily formed into a sheet-like material is employed. Also, a conductive layer providing step S2 described later.
2, when the conductive layer 18 is formed by electroless plating, in addition to the ease of molding, the surface is chemically roughened, that is, etching with chromic acid is easily performed.
BS or ABS alloy raw materials are preferred. In addition, other raw materials such as polycarbonate which can be etched with chromic acid by various pretreatments, nylon which can be etched with hydrochloric acid other than chromic acid, and the like can also be used.

The conductive layer providing step S22, which is performed subsequent to the resin body forming step S21, includes a step of forming a conductive layer 18 on the resin body 15 formed into a shape that can be laminated at a predetermined position on the plastic molded body 12. It is. The conductive layer 18 may be formed by wet plating such as electroless plating,
Chemical coating of conductive paint or metal, dry plating typified by physical vapor deposition, etc., as long as it imparts predetermined conductivity such as any one can be adopted, so below, The three methods will be described individually.

In the case where the conductive layer is formed by wet plating: (see FIG. 3) In the case where the conductive layer 18 is formed by wet plating such as electroless plating, this conductive layer applying step S 22 is performed on a required surface of the resin body 15. A pre-conductivity treatment step S2211 for performing pre-treatment required for conductivity, and a conductive layer 1 by wet plating.
And a conducting step S2212 for depositing the S.8. Examples of the pre-conductivity treatment step S2212 include the following three methods (1) to (3). (1) After the surface of the resin body 15 to be made conductive is chemically roughened, noble metal fine particles serving as a catalyst for the electroless plating reaction are adsorbed on the surface to be made conductive, and then the electroless plating selected as appropriate A method of forming a conductive layer 18 made of an electroless plated metal or the like having a predetermined thickness by dipping in a bath. (2) After applying a substance having the ability to precipitate electroless plating to the surface to be made conductive of the resin body 15 by adding it to a paint or the like, performing any necessary processing, and then appropriately performing the same processing as in (1). A method of forming a conductive layer 18 made of an electroless plating metal or the like having a predetermined thickness by dipping in a selected electroless plating bath. Here, the substance having the ability to precipitate electroless plating includes (A) fine particles of a noble metal serving as an electroless plating reaction catalyst or fine particles having the noble metal particles adhered to the surface, and (B) excellent ability to adsorb noble metal ions. And (C) metal powder which is electrochemically lower than the metal applied by electroless plating and generates a nucleus of the metal to be applied by a substitution reaction. (3) A method of performing a treatment such as chemical or physical roughening as necessary on the surface of the resin body 15 to be made conductive, and then forming the conductive layer 18 by electrolytic plating. For example, after performing chemical roughening with a chromic acid-sulfuric acid mixture or the like, a tin-palladium colloid is adsorbed at a high concentration to form a thin metal film and then deposited in an electrolytic plating solution containing a metal salt. (D-POP system; Ebara Age Light). In addition, as a substance other than the tin-palladium colloid, a method using an organic palladium colloid or an organic palladium complex, a method using a conductive polymer solution or a colloid, or a method using a carbon black or graphite powder dispersion liquid can also be used.

The pre-conductivity treatment step S2211 is one of pre-treatments for performing the later-described conductivity-conversion step S2213, and includes chemical or physical roughening and application of a substance or the like for depositing the conductive layer 18. Done. As the chemical roughening, any conventionally known method can be adopted depending on the material of the resin body 15. Generally, a mixture of chromic acid and sulfuric acid is suitably used for a raw material having an oxidized and easily meltable polymer component such as ABS as a dispersed phase, and a hydrochloric acid or the like is suitably used for a polyamide-based raw material. . As the physical roughening, a method using liquid honing or the like is generally used. Further, a surfactant or a paint may be applied to control the adsorption ability of the surface.

The substance which promotes the formation of the conductive layer 18 and its application are different for each of the above-mentioned methods (1) to (3). This will be described below.

In the case of (1): Conduction pre-treatment step S2211: The above-mentioned chemical roughening is performed on the resin body 15 serving as the base of the conductive layer 18, and then the catalyst activity is exhibited for electroless plating. A catalyst containing desired metal fine particles is adsorbed. Conducting step S2212: A conductive layer 18 made of a metal for electroless plating having a predetermined thickness is deposited on the catalyst by immersing it in a plating bath of an appropriately selected metal for electroless plating.

(2) will be described separately for each of the substances (A), (B) and (C) having the ability to deposit the electroless plating. Further, the conductive stage S2212 is the same as the above (1), and thus detailed description is omitted.

(A) As the pre-conductivity treatment step S2211, a desired metal fine particle exhibiting catalytic activity with respect to electroless plating or a polymer compound as a paint containing particles having the fine particles adhered to the surface is used. It is applied to the surface of the resin body 15 to be made conductive by means such as spraying. Next, the surface of the polymer compound is chemically roughened with an etching agent such as an acid or an alkali to expose the metal fine particles. Then, the conductive layer 18 is deposited in the conductive step S2212. As a specific example, there can be cited one in which silver metal fine particles precipitated on the surface of fine particles of silicon oxide or the like larger than these fine particles are dispersed in a synthetic resin as a paint.

(B) As the pre-conductivity treatment stage S2211,
A substance having an excellent ability to adsorb the fine particles as a catalyst described in (1) and (A) is applied to the conductive surface of the resin body 15 by means such as spraying. Next, it is immersed in a catalyst tank containing a desired metal fine particle catalyst exhibiting catalytic activity for electroless plating to adsorb fine particles as a catalyst. Then, the conductive layer 18 is deposited by performing the conductive step S2212. A specific example is a chelate resin containing a substance capable of adsorbing noble metal ions such as chitosan.

(C) As the pre-conductivity treatment step S2211, a predetermined amount of metal powder that is electrochemically lower than the metal applied by electroless plating and generates nuclei of the electroless plated metal by a substitution reaction is used. The polymer compound contained is applied to the conductive surface of the resin body 15 by spraying or the like. Next, the core is immersed in an aqueous solution containing the ionized electroless plating metal to generate nuclei of the electroless plating metal. Then, the conductive layer 18 is deposited in the conductive step S2212. As a specific example, a high adsorption ability such as a tin-palladium catalyst, a synthetic resin latex having a polar functional group,
Modified silicone resin or cyanoacrylate resin, or those containing nickel fine particles and capable of easily displacing and depositing copper in an acidic copper salt solution and depositing copper in electroless copper plating can be used.

In the case of (3): Conduction pretreatment step S2211:
A predetermined physical roughening such as liquid honing or a chemical roughening using an etching agent such as an acid or an alkali is performed. Next, a conductive substance such as a palladium-uzud colloid, an organic palladium, a conductive polymer or a carbon material colloid is adsorbed. Note that at this stage, a thin conductive layer may be formed using the conductive material as necessary. Conduction stage S221
2: A required surface made conductive by the conductive material is brought into contact with an electrode to form a negative electrode, a positive electrode is formed with a soluble or insoluble electrode, and a current is applied to these electrodes to form a conductive layer 18 by electrolytic plating.

In each of the methods (A) and (B) of the above (1) and (2), the fine particles exhibiting catalytic activity for electroless plating are, for example, gold, ruthenium, Noble metals such as rhodium, palladium, iridium, osmium or platinum are exemplified. As a method of adsorbing the noble metal fine particles on the non-plated surface, the following (a) to (d)
4 methods. (a) A method of sequentially immersing in two kinds of solutions of tin chloride and palladium chloride, reducing palladium with the tin, and applying metal palladium as a catalyst to the surface. (b) immersing in a complex chloride colloid solution of tin and palladium to adsorb the complex chloride, followed by washing with water to reduce the palladium to metal with tin and remove the tin oxide with sulfuric acid or the like; The palladium remaining on the surface as a catalyst. (c) A method of immersing in a palladium chloride solution and then immersing in a reducing agent solution and using palladium reduced to metal as a catalyst. (d) adding a surfactant to various catalyst noble metal salt solutions,
A method of immersing in a catalytic noble metal colloid solution obtained by adding a reducing agent while stirring. In this case, the colloid solution is obtained by dissolving a water-soluble salt of a compound of a catalytic noble metal, adding a surfactant, and adding a reducing agent while stirring vigorously. There are various surfactants,
Anionic or cationic surfactants are preferred,
For example, soap, higher alcohol sodium sulfate, sodium alkyl benzene sulfonate, sodium polyoxyethylene alkyl ether sulfate, lauryl trimethyl ammonium chloride, alkylbenzyl dimethyl ammonium chloride and the like are used.

The fine particles of the catalytic metal need not be formed as a continuous film, but may be adsorbed on the adhesive layer 14. If the catalyst metal particles are not adsorbed to a certain high concentration and the concentration is too low, the conductive layer 18 will not be formed.
Care must be taken because the adhesion between the conductive layer 5 and the conductive layer 18 or the like becomes weak.

The conduction stage S2212 by wet plating is as follows:
Forming the conductive layer 18 by applying the plating metal having excellent conductivity to the catalyst metal by electroless plating,
In this step, a resin shield body 16 is obtained from the resin body 15. Depending on the degree of corrosion resistance of the conductive layer 18 applied to the resin shield body 16 in the use environment, nickel or tin or another kind of metal may be continuously subjected to electroless plating or electrolytic plating as necessary. S2
214 may be performed. Here, the thickness of the conductive layer 18 applied by plating is preferably about 0.5 to 2 μm,
If the thickness is more than this, the manufacturing time and cost will increase.

As the metal for electroless plating employed in the conducting step S2212, electroless copper or electroless nickel-phosphorus alloy, which is relatively easy to manage a plating bath and is widely used in industry, is used. It is suitable. Other metals for electroless plating include electroless copper, nickel and phosphorus alloys,
Examples include electroless nickel-boron alloy, electroless cobalt-phosphorus alloy, electroless gold, electroless silver, and electroless palladium. When electrolytic plating is adopted, copper or nickel, which is widely used industrially, is suitable as the electrolytic plating metal. Other metals for electrolytic plating include alloys such as manganese, zinc, iron, tin, chromium, gold, silver, palladium, lead and nickel-manganese alloys.

As an example of the second conductive layer S2213 described above, copper having excellent conductivity is used for the first conductive layer, and nickel-phosphorus alloy having excellent corrosion resistance is used for the second conductive layer. If used, the conductive layer 18 having both excellent conductivity and corrosion resistance can be formed. This second conductive stage S2213
The electroless plating metal and the electroplating metal preferably used in the above are the same as those described in the above [0032].

In the case of forming a conductive layer with a conductive paint: (see FIG. 3) The conductive layer providing step S22 of forming the conductive layer 18 with the conductive paint is basically performed on a required surface of the resin body 15 by a conductive method. By applying and drying a polymer compound as a paint containing filler or various metals by means such as spray coating,
It consists only of a conducting step S2221 for forming the conducting layer 18.

The step S2221 for making the conductive material conductive is as follows.
It is carried out by applying a conductive paint in which a conductive filler imparting conductivity is dispersed in a polymer compound as a paint to a required surface of the resin body 15 by a method such as spray coating or brush coating. . The conductive paint applied to the surface is dried and fixed to form a conductive layer 18, and a resin shield 16 is obtained from the resin 15. Here, the thickness of the conductive layer 18 applied with the conductive paint is 20 to 100.
A thickness of about μm is preferred. If the thickness is too small, sufficient conductivity cannot be obtained, and if the thickness is too large, the production time and cost increase, and the fear of the coating film cracking during use and falling off increases.

As the conductive filler, a carbon material,
A metal powder, a metal fiber, a conductive ceramic, or a composite material obtained by depositing carbon on the surface of a potassium titanate whisker can be suitably used. Examples of the carbon material include graphite powder, carbon black and carbon fiber, and examples of the conductive ceramic include indium tin oxide and titanium nitride. Examples of the metal powder or various metals include aluminum, copper, nickel, silver, gold, platinum, palladium, and brass. Further, as the polymer compound as a paint containing the conductive filler or the like, a polyurethane resin, an epoxy resin, a polyester resin, a melamine resin, a phenol resin, a silicone resin, a styrene resin, a polyvinylidene fluoride resin or a paint such as an acrylic resin A high molecular compound that can be used as a polymer can be suitably used.

When the conductive layer is formed by dry plating: (see FIG. 3) When the conductive layer 18 is formed by dry plating such as evaporation, the conductive layer providing step S22 is basically performed by forming aluminum on the resin shield body 16 A conductive step S2231 for forming the conductive layer 18 by applying a metal such as
Consists only of

The conducting step S2231 by dry plating
Examples include Chemical Vapor Doposition (CVD) or Physical Vapor Deposition (physical vapor deposition). The CVD is for forming the conductive layer 18 through a chemical reaction from a gaseous raw material, and the PVD is for obtaining the conductive layer 18 required to undergo a physical process, such as vacuum deposition or splatter deposition. Taking a general chemical vapor deposition method as an example, a deposition auxiliary material such as a catalyst is applied to a required surface of the resin body 15 and placed in a predetermined reaction tube. Then, a source gas containing a metal to be deposited (such as alkylaluminum in the case of aluminum deposition) is introduced into the reaction tube. Next, the flowing source gas is excited by using an energy source such as heating, plasma, or light to cause a deposition reaction to proceed. At this time, various reactive substances may be contained in the raw material gas. As a metal to be used at this time, copper, nickel, cobalt, aluminum, titanium, gold, palladium, or the like is suitable, and these are used as a single layer or a laminate.

In the adhesive layer applying step S3, an adhesive is applied to each of the parts to be applied of the plastic molded body 12 and / or the resin shield body 16 by means of spray coating or the like, and dried to form the adhesive layer 14. This is the step of forming. The application of the adhesive layer is performed by, for example, spray coating or roller coating, which is most efficient for the physical properties such as the viscosity of the employed adhesive.

The adhesive exhibits excellent adhesiveness and adhesiveness at the time of bonding and during use, and loses adhesiveness and adhesiveness by reducing the viscosity by predetermined heating, and exhibits peelability. A substance containing a polymer compound as a main component such as a hot-melt type adhesive or an adhesive containing heat-expandable particles which expand by heating, the substance to be adhered by expansion of the particles under predetermined heating. It is preferable that the material exhibit releasability by remarkably reducing the contact area therebetween.

The thickness of the adhesive layer 14 is 5 to 50.
A thickness of about μm is preferable. If the thickness is too thin, the adhesive strength is reduced, and there is fear of peeling. If the thickness is too thick, wasteful production costs are required. The adhesive layer 14 is basically formed by disposing the conductive plastic molded product according to the present embodiment and disposing the plastic molded body 12 occupying most of the whole and the resin provided with the conductive layer 18 made of various metal materials and the like. Shield body 16
Are easily separated from each other, and each of them is generally a polymer viscous body having an appropriate viscosity. When the plastic molded body 12 and the resin shield body 16 are separated and discarded, the adhesive forming the adhesive layer 14 remains on the plastic molded body 12 and is taken in as an impurity when the plastic material is collected. But
The amount is as small as several tens g / m ^2, and hardly affects the recovery and regeneration of the plastic material. Further, as the adhesive, the plastic molding 1
Selection of a substance compatible with 2 can also address the above-mentioned problem.

If the adhesive contains heat-expandable particles that expand under heating, the adhesive is applied to the resin shield 16 and dried, and then the plastic molded body 12 is heated. Is assembled by pressing the adhesive applied surface. Therefore, the contact area between the adhesive layer and the resin shield body 16 is substantially equal to the adhesive application area on the resin shield body 16, while the contact area on the plastic molded body 12 is It is relatively small because it is only pressed. As a result, the plastic molding 12
Separation occurs from the non-contact portion between the adhesive and the adhesive due to the thermal expansion of the thermally expandable particles, and separation can be performed without leaving the adhesive on the plastic molded body 12 side.

The molded body manufacturing process S1 performed so far,
Resin shield body manufacturing step S2 and adhesive layer providing step S3
Accordingly, the plastic molded body 12 and the conductive layer 18 for manufacturing the conductive plastic molded body according to the present embodiment
Are formed, and all preparations for bonding and laminating and integrating them are completed. The next assembly step S4 is a step of laminating and integrating the plastic molded body 12 and the resin shield body 16 with the adhesive layer 14 interposed therebetween. In a final step S5, the conductive plastic molded product is subjected to washing and drying, processing, and inspection as necessary to complete the product.

[0044]

[Experimental Examples] A method of manufacturing a conductive plastic molded product according to the examples and experimental examples of the obtained conductive plastic molded product will be described below.

Molding step S1: PC / carbon containing 10% by weight of carbon fiber as a raw material of a plastic molding
By using an ASA material (trade name: FA420CA; manufactured by Mitsubishi Rayon Co., Ltd.), a box-shaped plastic molded body having a size of 210 × 260 × 20 and a thickness of 1.2 mm and opening upward was obtained by injection molding.

-Resin shield manufacturing step S2: In the molding step S21, ABS is used as a raw material for a plastic molded product.
Using a resin (trade name: Psycholux EPX; manufactured by Ube Sycon), a 0.2 mm seed-like material is first prepared, and then a box-shaped resin that is tightly laminated on the inner surface of the plastic molded body by vacuum molding. I got a body. Conductive layer providing step S22 (S221): Through the following steps, a resin shield body having a conductive layer formed on a required surface of the resin body was produced. In the pre-conductivity treatment step S2211,
Sodium sulfate 20 g / L and sodium phosphate 20
g / L in a degreasing solution at a temperature of 50 ° C. for 4 minutes to perform degreasing. Etching was performed by immersion at a temperature of 10 ° C. for 10 minutes. Then, after sufficient washing, 35
Neutralization was performed by immersion in a room temperature neutralizing solution of 50% hydrochloric acid / L for 1 minute. Then, wash with water and 180% of 35% hydrochloric acid.
After immersion in a 1 / L pre-dip tank, a palladium-tin catalyst (trade name: Catalyst C; manufactured by Okuno Pharmaceutical Co., Ltd.) was placed in a catalyst bath consisting of 30 ml / L and 35% hydrochloric acid 200 ml / L at a temperature of 35%. C. for 2 minutes. Then, it is washed with water, and a surface activator (trade name: Accelerator X; manufactured by Okuno Pharmaceutical Industries) 0.5 g / L and 98%
It was immersed in an accelerator bath composed of 100 ml / L of sulfuric acid to sufficiently apply palladium as a catalyst metal to the surface of the resin shield, and finally washed with water. In the conductive stage S2212, an electroless copper plating bath (trade name: TSP
-810 electroless copper standard recipe;
It was immersed at 30 ° C. for 30 minutes to deposit an electroless copper plating layer of about 2 μm. In the second conductive stage S2213, the substrate is immersed in an electroless nickel plating bath (trade name: TSP-48 nickel standard prescription; manufactured by Okuno Pharmaceutical Co., Ltd.) at a temperature of 50 ° C. for 10 minutes to obtain an electroless nickel plating of about 0.3 μm. The layers were deposited.

Adhesive layer applying step S3: 60 parts by weight of butyl acrylate as a polymer compound, 40 parts of ethyl acrylate
100 parts by weight of an acrylic copolymer composed of 5 parts by weight of acrylic acid and 5 parts by weight of acrylic acid are dissolved in toluene, and 5% by weight of a urethane-based crosslinking agent and heat-expandable microspheres (trade name: Matsumoto Fibers) as a heat-expanding substance Fair F-
50D (Matsumoto Yushi) was added as an adhesive. Then, the resin shield body was covered with a wooden jig having a required shape, and the adhesive was spray-coated only on an outer portion to be attached so as to have a dry thickness of 40 μm to form an adhesive layer.

Assembling step S4: The resin shield body on which the adhesive layer is formed in the adhesive layer applying step S3 and the plastic molded body are held in a laminated state and pressed down evenly by hand so that a load of about 100 N is applied. The operation was performed 10 times while changing the location, and the resin shield body and the plastic molded body were laminated and integrated.

Evaluation items, evaluation methods and results (physical properties) Adhesive strength between plastic molded article and resin shield: Evaluation method: length of conductive plastic molded article bonded and laminated with plastic molded article and resin shield 2
A test piece having a width of 10 mm and a width of 20 mm was prepared. Then, about 50 mm from the end of the resin shield body layer of the test piece was peeled off from the plastic molded body, and the molded body was fixed to an aluminum plate having a thickness of 0.5 mm with an instantaneous adhesive. The peeled end face was gripped by a tensile tester chuck, and the peel strength was measured by 90 degrees. At this time, referring to JIS Z 0237 "Testing method for pressure-sensitive adhesive tape / pressure-sensitive adhesive sheet", the 90-degree peeling jig and the measurement of the pressure-sensitive adhesive force were the same (adhesive layer (adhesive), width and assembly of the adhesive layer (adhesive)). The method of crimping is different). Table 1 below
As shown in the figure, sufficient adhesive strength was confirmed. Adhesion: Evaluated according to “Tape test method” in “Plating adhesion test” specified in JIS H8504. That is, the portions that were not peeled off after performing a predetermined treatment on 25 squares each having a side of 2 mm and separated by a notch penetrating the surface of the conductive layer were counted. As a result, as shown in Table 2 below, no peeling occurred even when a peeling test was performed on the cross-cut surface with the adhesive tape, and good adhesion was confirmed. EMI shielding performance: 150 mm from the prepared conductive plastic molded article to a KEC-compliant shielding effect measuring jig
A spectrum analyzer equipped with a tracking generator by cutting out and mounting a × 150 mm square test specimen
(Trade name: 8560A; manufactured by Hewlett-Packard) was used to measure the shielding characteristics of the electric wave and the magnetic wave in the frequency band of 1 MHz to 1 GHz, using the attenuation ratio of the intensity of the transmitted wave to the intensity of the incident wave as the shielding effect. For reference, a comparison table of the shielding effect and its quality is shown in Table 3 below. As a result of the evaluation, as shown in Table 4 below, 1 MHz to 1 GH
At z, a shielding effect that can be sufficiently used as an electronic device was confirmed.

Evaluation items, evaluation methods and results (recyclability) Recycling (recycling) rate after disposal: The obtained conductive plastic molded product was treated with a conductive plastic obtained in a hot air circulation type high temperature dryer at 150 ° C. The molded article was left for 10 minutes. As a result, the plastic molded article and the resin shield constituting the conductive plastic molded article could be easily separated by hand. The plastic molded body is crushable and re-moldable. A predetermined JIS test piece is formed from the crushed material, and various physical properties such as tensile strength, elongation at break and Izod impact strength are measured. Is within ± 10% of that of the JIS test piece molded from the virgin material of the plastic raw material, and it was confirmed that the recycled product had good physical properties. Also, the weight before processing (weight of the conductive plastic molded product) and the weight after processing
(Recycled molded article) The regeneration rate calculated from the weight was as good as about 83% by weight. Furthermore, the weights of various resin materials and metal materials contained in the resin shield body are 12% by weight and 2% by weight, respectively, and these can also be recycled by treatment in a gasification melting furnace or the like.

[0051]

As described above, according to the conductive plastic molded product according to the present invention, the conductive shield and the plastic material are largely formed by the adhesive layer formed from the adhesive which is peeled off by heating. , The plastic molded body occupying the same is easily separable, so that when the molded article is subjected to material recycling after disposal, there is an advantage that the plastic material constituting the conductive plastic molded article can be recovered at a high regeneration rate. . Further, the production method of the present invention is capable of producing the above-mentioned conductive plastic molded article suitably and efficiently.

[Brief description of the drawings]

FIG. 1 is a partially cutaway perspective view of a conductive plastic molded product according to the present invention.

FIG. 2 is an enlarged sectional view taken along line II-II in FIG.

FIG. 3 is a process chart showing a method for manufacturing a conductive plastic molded product according to a preferred embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 12 plastic molded body 14 adhesive layer 15 resin body 16 resin shield body 18 conductive layer

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H05K 9/00 H05K 9/00 X // B29K 701: 00 B29K 701: 00 B29L 9:00 B29L 9:00 F-term (reference) 4F100 AC01G AK01A AK01B AK01C AK25G AK51G AK74 AR00B AT00A BA03 BA07 BA10A BA10B CA21B CB05 CC00B DE04G EC182 EH361 EH462 EH661 EH711 EJ151 GB41 JA02G JB20G JD08 JG01 A03J02A01 TN53 TN58 TQ01 4K024 AA03 AA09 AB02 AB17 BA12 BB18 GA16 5E321 BB23 BB32 GG05

Claims (10)

[Claims] A plastic molded body (12) molded into a required shape from an electrically non-conductive plastic raw material and a conductive layer (18) for imparting conductivity are formed and laminated on the plastic molded body (12). Resin shield body (16), which is interposed between the plastic molded body (12) and the resin shield body (16), adheres both members (12, 16), and exhibits peelability by heating. A conductive plastic molded product comprising an adhesive layer (14). 2. The conductive plastic molded article according to claim 1, wherein said adhesive layer (14) is made of a hot-melt type adhesive which is melted by heating. 3. The conductive plastic molded article according to claim 1, wherein said adhesive layer (14) contains a heat-expandable substance expandable by heating. 4. The conductive plastic molded article according to claim 1, wherein the thickness of the resin shield body (16) is 20% or less of the thickness of the plastic molded body (12). 5. A plastic molded body (12) having a required shape is formed from an electrically non-conductive plastic raw material, and a sheet-like material made of the plastic raw material is molded to adhere to the plastic molded body (12). Resin body (1
After preparing 5), a conductive layer (18) is formed on a required surface of the resin body (15) to be made conductive, and a resin shield body (16) is manufactured.Then, the plastic molded body (12) and the resin shield are formed. Body (1
6), the adhesive layer (14) is formed by applying an adhesive which exhibits releasability by heating, and the plastic molded body (12) and the resin are formed by the adhesive layer (14). A method for producing a conductive plastic molded product, wherein a shield body (16) is bonded. 6. The method for producing a conductive plastic molded article according to claim 5, wherein the adhesive is a hot-melt adhesive which melts by heating. 7. The method for producing a conductive plastic molded product according to claim 5, wherein the adhesive contains a heat-expandable substance that can be expanded by heating. 8. The conductive layer (18) is provided with a substance such as a catalytic metal that exhibits a catalytic effect on a wet plating reaction such as electroless plating to the resin shield body (16). The method for producing a conductive plastic molded product according to any one of claims 5 to 7, wherein the molded product is formed by performing the following. 9. The conductive layer according to claim 5, wherein said conductive layer is formed by applying a conductive paint made of a polymer compound containing a conductive substance such as a conductive filler. Method for manufacturing conductive plastic molded products. 10. The method according to claim 5, wherein the conductive layer is formed by dry plating such as vacuum deposition.