JP2007191738A - Molded body having metal film and its production method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To directly deposit a metallic film on a base material composed of a hardly adhesive resin by vacuum deposition without applying a primer or the like, and to provide an electromagnetic wave shielding molded body or a brightened molded body at a low cost with high productivity. <P>SOLUTION: A base material composed of a polyamide resin, a polyphenylene sulfide resin, the one obtained by incorporating a glass fiber therein, a liquid crystal polymer or the like is subjected to blasting treatment, and thereafter, an electromagnetic wave shielding film or a brightened film is deposited on the surface of the base material subjected to the blasting treatment by vacuum deposition. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a molded body in which an electromagnetic wave shielding film and a brightening film are formed on a substrate, and a method for manufacturing the same.

  Engineering plastics are thermoplastic, lightweight, and have functions such as high heat resistance, high strength and chemical resistance that can be substituted for metal materials, and thus are used in many industrial fields.

  In order to impart electrical conductivity, further improve its characteristics, impart a lustrous appearance, etc., and to function as an antistatic or electromagnetic wave shield, in such engineering plastics as well as various resins and plastics The surface treatment is performed.

  For example, in an electronic device such as a mobile phone and an electric device such as a connector and a socket, an electromagnetic wave shielding process is applied to the inside of the casing in order to avoid malfunction of the device due to transmission and reception of radio waves. As a method of performing electromagnetic wave shielding treatment on such a case, a method of mixing a conductive metal in the base material, a method of applying a conductive paint to the surface of the base material, and a method of applying a conductive paint to the surface of the base material A method of forming a metal film as an electromagnetic shielding film by wet plating or vacuum deposition is known.

  In addition, when the various molded bodies are subjected to a brightening treatment and used for decorative purposes such as door knobs, a metal film is similarly formed as a brightening film on the surface of the base material.

  In recent years, due to demands for weight reduction and thinning of products, polyamide resins, polyphenylene sulfide (PPS) resins, and glass fibers made of these resins, as engineering materials, have high strength and rigidity even when they are thin. It is required to use what is included.

  However, when such surface treatment is intended, in general, the base material is limited to ABS resin, polycarbonate (PC) resin, or a mixed resin of ABS and polycarbonate. is there.

  For example, the electroless plating method is used in the film formation by the wet plating method. In this method, chromic acid etching or palladium catalyst addition is performed, so that the adhesion between the base material and the thin film becomes strong. However, when polyamide resin or polyphenylene sulfide resin is used as a base material, these materials themselves are resistant to organic solvents and chemicals, or these materials contain glass and various additives as composite materials. Therefore, the surface properties suitable for plating cannot be obtained. On the other hand, if processing is performed under conditions that provide surface properties suitable for plating, problems such as deformation of the base material occur. For this reason, a wet plating method for engineering plastics has not been established except for ABS resin and polycarbonate resin. The wet plating method also has a problem of waste liquid treatment, a problem of long treatment time, and a problem of plating on both surfaces of the substrate.

  On the other hand, in the film formation by vacuum deposition, a method of forming aluminum with a film thickness of 2 μm to 3 μm, or a method of forming nickel as a protective film with copper as the first layer is common. However, when polyamide resin or polyphenylene sulfide resin is used as the base material, these materials have poor adhesion to the metal film, so it is necessary to physically rough the base material surface or to apply a primer to the base material surface. Yes, except for ABS resin and polycarbonate resin, a metal film is not directly formed on an engineering plastic by vacuum deposition.

  For example, Japanese Patent Application Laid-Open No. 7-133361 describes an electromagnetic wave shielding plastic molding in which an aluminum film is formed on an ABS / PC base material by bombarding with high frequency excitation plasma. However, a base material made of a polyamide resin or the like cannot be applied because the surface is not modified by such a treatment and the adhesion to the film is weak.

  Japanese Patent Application Laid-Open No. 7-70345 describes an electromagnetic wave shielding plastic molded article obtained by forming a primer coat layer made of a water-soluble paint on a plastic molded article and forming an aluminum film or a copper film. However, as a plastic molding, only a polycarbonate (PC) / ABS resin is blended with a glass fiber blending material and a carbon fiber blending polycarbonate (PC) molding material, but not a polyamide resin. . This is because a base material made of polyamide resin or the like is not attacked by a normal water-soluble paint, and there is a problem that strong adhesion cannot be obtained between the base material and the primer.

  In JP-A-7-7283, JP-A-6-240034, JP-A-6-240027, JP-A-6-157797 and JP-A-6-145396, a substrate made of plastic is washed. In addition, a technique is described in which the surface is cleaned with high-frequency excitation plasma without applying a primer, and is brought into close contact with the film. These can be applied to ABS resins containing a large amount of surface functional groups and alloys thereof, but polyamide resins and polyphenylene sulfide resins having almost no surface functional groups do not sufficiently modify the surface, and the substrate and film There was a problem that did not adhere strongly.

  Techniques for forming an electromagnetic wave shielding film on nylon fibers and the like are described in JP-A No. 2001-32150, JP-A No. 10-46443, JP-A No. 10-8317 and JP-A No. 6-330677. . However, in these, there exists a problem that there is no adhesive force of the grade used for industrial uses, such as an electronic device, an electric device, and a decorative article.

JP-A-7-133361

JP-A-7-70345

Japanese Patent Laid-Open No. 7-7283

JP-A-6-240034

JP-A-6-240027

JP-A-6-157797

JP-A-6-145396

JP 2001-32150 A

Japanese Patent Laid-Open No. 10-46443

Japanese Patent Laid-Open No. 10-8317

JP-A-6-330677

  The present invention provides a method for forming a metal film by vacuum deposition on a base material that has high strength and rigidity, such as polyamide resin or polyphenylene sulfide resin, but is difficult to surface-treat without applying a primer or the like. The object is to provide a molded body in which an electromagnetic wave shielding film and a brightening film are directly formed on a substrate.

  The method for producing a molded body of the present invention is characterized in that a surface of a base material made of a hardly adhesive resin is subjected to blasting, and a metal film is formed on the surface subjected to the blasting by vacuum deposition. To do.

  Here, the hard-to-adhere resin is a resin whose surface is not easily affected by a solvent among engineering plastics. In addition, thermosetting resin is more difficult to adhere due to the difference in surface functional groups than thermoplastic resin. The resin has crystallinity and non-crystallinity, but the adhesion cannot be judged by itself. A plastic having a heat-resistant temperature of 150 ° C. or higher has poor adhesion. Except ABS resin, polyethylene terephthalate, polyurethane, syndiotactic polystyrene, polyamide, polyacetal for crystalline resin, polycarbonate for amorphous resin, polyphenylene sulfide, fluoro resin, polyether ketone for modified polyphenylene ether crystalline heat resistant super resin, Liquid crystal polymer, polyether nitrile. Non-crystalline heat resistant super resin refers to polysulfone, polyethersulfone, polyarylate, polyamideimide, polyetherimide, and thermoplastic polyimide.

Specifically, as the blasting treatment, glass beads or ceramic fine powder having a particle size of 50 μm to 500 μm are treated with air at a pressure of 0.196 MPa (2 kg / cm ² ) to 0.392 MPa (4 kg / cm ² ). Spray on the surface of the material. As the ceramic fine powder, alumina oxide, silicon carbide or the like can be used.

  By forming a copper film having a film thickness of 0.5 μm to 2 μm as an electromagnetic wave shielding film on the surface of the base material subjected to such blasting treatment, an electromagnetic wave shielding molded article can be obtained.

  A protective film made of nickel, nickel alloy, chromium, chromium alloy, Sn—Cu—Cr alloy, or Sn—Cu—Ni alloy having a thickness of 0.1 μm to 0.3 μm is formed on the copper film. It is preferable to form a film.

  In the case of a bright molded article, on the surface of the base material without forming an electromagnetic wave shielding film, nickel, a nickel alloy, chromium, a chromium alloy with a film thickness of 0.1 μm to 0.3 μm, A brightening film made of either Sn—Cu—Cr alloy or Sn—Cu—Ni alloy is formed.

  It is preferable to further apply clear coating on the protective film or the brightening film. For clear coating, acrylic resin, polyester resin, polyurethane resin or the like is used.

  By this method for producing a molded article, an electromagnetic wave shield molded article comprising a base material made of a hardly adhesive resin and an electromagnetic wave shielding film directly formed on the base material is obtained.

  In the present invention, the base material particularly has high strength and rigidity such as polyamide resin, polyamide resin containing glass fiber, polyphenylene sulfide resin, polyphenylene sulfide resin containing glass fiber, and liquid crystal polymer resin. The present invention can be applied to a substrate made of a material having it.

  According to the present invention, it becomes possible to directly form a metal film as an electromagnetic wave shielding film or a brightening film on a substrate that is difficult to be surface-treated, such as a polyamide resin, a polyphenylene sulfide resin, or a liquid crystal polymer resin. The brightened molded body can be provided with low cost and high productivity.

  The present invention is characterized in that a blast treatment is performed on a base material made of any one of a polyamide resin, a polyamide resin containing glass fibers, a polyphenylene sulfide resin, a polyphenylene sulfide resin containing glass fibers, and a liquid crystal polymer resin. There is.

The blasting, particle size using glass beads or ceramic powder of 50 microns and 500 microns, the fine powder, for example by an air gun, pressure ^{0.196MPa (2kg / cm 2) ~0.392MPa} (4kg / cm 2 ) To the surface of the substrate with air. As the material of the ceramic fine powder, alumina oxide, silicon carbide, or the like can be used.

  Generally, abrasives include resins, glass, plant species, metals, ceramics, etc. However, engineering plastics to which glass fibers have been added have high surface hardness, so resin or plant fines are reinforced with glass. You can't roughen the surface. In addition, since metal is severely chipped or worn, it is desirable to use fine powder with high hardness such as glass or ceramic.

  The size of the fine powder is desirably 50 μm to 500 μm. If it is less than 50 μm, the surface unevenness is not sufficiently formed, and strong adhesion cannot be obtained.

  On the other hand, if it exceeds 500 μm, the surface unevenness becomes large, and the glitter is lost, or the resistance value becomes high when a film is formed, which is not preferable.

Moreover, if the pressure at the time of spraying is less than 0.196 MPa (2 kg / cm ² ), there are few surface irregularities, and sufficient adhesion cannot be obtained. When it exceeds 0.392 MPa (4 kg / cm ² ), the base material is deformed, or a polishing agent is embedded in the base material, and foreign matter adheres to the surface.

  When a metal film is formed by vacuum deposition on the surface of the base material that has been subjected to the blasting process, high adhesion between the base material and the metal film can be obtained.

  For example, in order to obtain an electromagnetic wave shield molding, the surface of the substrate is blasted, and then a copper film having a film thickness of 0.5 μm to 2 μm is formed as the electromagnetic wave shielding film. A nickel, nickel alloy, chromium, chromium alloy, Sn—Cu—Cr alloy, or Sn—Cu—Ni alloy having a thickness of 0.1 to 0.3 μm is formed on the film as a protective film.

  The film formation is desirably performed by vacuum vapor deposition with excellent environmental properties so that the film formation is uniform. Specifically, it is desirable to use an ion gun that melts the high melting point target with an electron gun, evaporates the metal, and forms a film on the base material, or sputtering with an alloy component, so that the film thickness is uniform. .

  In addition, the film thickness of a copper film shall be a film thickness with which an electromagnetic wave shielding characteristic is acquired. If it is less than 0.5 μm, the resistance value is high and the electromagnetic wave shielding characteristics are low. On the other hand, when the thickness exceeds 2 μm, the film stress becomes strong, and the copper film may be peeled off from the substrate in a heat resistance test or the like. Further, even when the film is formed to exceed 2 μm, the resistance value does not decrease and the film formation time is extended, so that the manufacturing cost is also increased.

  Moreover, by applying a protective film, moisture resistance, acid resistance, etc. improve, and it can use it suitably for industrial uses, such as an electronic device and an electric equipment.

  Nickel, nickel alloy, chromium, or chromium alloy has high corrosion resistance, and Sn—Cu—Cr alloy or Sn—Cu—Ni alloy has a low melting point of Sn. If the film thickness is less than 0.1 μm, pinholes are generated in the film, and the film is further thinned on the standing surface of the product. If it exceeds 0.3 μm, there is almost no change in corrosion resistance, and the film stress increases, so that the film may crack and corrode copper.

  Furthermore, by applying clear coating on the metal film formed on the base material using acrylic resin, polyester resin, polyurethane resin, etc. excellent in weather resistance, the glitter feeling obtained by the protective film is maintained, A molded body having excellent environmental resistance can be provided.

  In addition, when using the molded object obtained by brightening for exterior components or a vehicle-mounted use, a copper film may be abbreviate | omitted, the said protective film may be formed as brightening, and clear coating may be given to this.

Example 1
A base material (Mitsubishi Engineering Plastics Co., Ltd., Reny (registered trademark) 1022H) containing 50% × 50 mm and a thickness of 2 mm was used, each containing 50% polyamide resin and glass fiber.

First, glass beads having a particle diameter of 100 μm as an abrasive were put into an air gun having a nozzle diameter of 2 mm and shot for 10 seconds at a pressure of 0.196 MPa (2 kg / cm ² ). After the treatment, the substrate was air blown to blow off the glass beads on the surface.

  Next, it was attached to an ion plating apparatus (AAIH-W36200SBT, manufactured by Shinko Seisakusho Co., Ltd.), a copper film was formed with a film thickness of 1 μm on the first layer, and a nickel film was formed with a film thickness of 0.2 μm on the second layer. .

  The electromagnetic shielding molded body obtained as described above was evaluated using the test items shown in Table 1. The results are shown in Table 1. In the cross-cut tape peeling test, the cross-cuts were 1 mm apart.

(Example 2)
Using a base material (Toyobo Co., Ltd., PPS resin (containing 40% glass), TS401) having a thickness of 50 mm × 50 mm and a thickness of 2 mm, copper was formed to a thickness of 1.5 μm in the first layer, and two layers were formed. An electromagnetic wave shielding molded article of Example 2 was obtained in the same manner as in Example 1 except that a Sn—Cu—Cr alloy film was formed to a thickness of 0.2 μm.

  The electromagnetic wave molded molded body obtained as described above was evaluated using the same test items as in Example 1. The results are shown in Table 2.

(Example 3)
An electromagnetic wave shielding molded article of Example 3 was obtained in the same manner as in Example 1 except that alumina oxide having a particle size of 100 μm was used as the abrasive.

  The electromagnetic wave molded molded body obtained as described above was evaluated using the same test items as in Example 1. The result was exactly the same as in Example 1.

Example 4
An electromagnetic wave shielding molded article of Example 4 was obtained in the same manner as in Example 1 except that 0.1 μm of Hastelloy G (registered trademark) was formed in the second layer.

  The electromagnetic wave molded molded body obtained as described above was evaluated using the same test items as in Example 1. The result was exactly the same as in Example 1.

(Example 5)
An electromagnetic wave shielding molded article of Example 5 was obtained in the same manner as Example 1 except that Sn—Cu—Ni was formed to a thickness of 0.2 μm as the second layer.

  The electromagnetic wave molded molded body obtained as described above was evaluated using the same test items as in Example 1. The result was exactly the same as in Example 1.

(Example 6)
A 50 mm × 50 mm base material (Mitsubishi Engineering Plastics Co., Ltd., Reny (registered trademark) 1022H) containing 50% by 50% each of polyamide resin and glass fiber was used.

First, glass beads having a particle diameter of 100 μm as an abrasive were put into an air gun having a nozzle diameter of 2 mm and shot for 10 seconds at a pressure of 0.196 MPa (2 kg / cm ² ). After the treatment, the substrate was blown with air to blow off the glass beads on the surface.

  Next, it is attached to an ion plating apparatus (AAIH-W36200SBT, manufactured by Shinko Seisakusho), a Sn—Cu—Cr alloy film is formed with a film thickness of 0.1 μm, and an acrylic top coat (manufactured by Fujikura Kasei, ET5406A) is 10 μm. It was spray coated and dried at 80 ° C. for 30 minutes. The appearance was chromium and had a reflectance of 58% (550 nm wavelength).

  The brightened molded body obtained as described above was evaluated using the test items shown in Table 3. The results are shown in Table 3. In the cross-cut tape peeling test, the cross-cuts were 1 mm apart.

(Example 7)
Except that a connector made of a liquid crystal resin (manufactured by DuPont, trade name: Zenite) was used as a base material, the same treatment as in Example 1 was performed to obtain an electromagnetic wave shielding molded body of Example 7.

  The electromagnetic wave molded molded body obtained as described above was evaluated using the same test items as in Example 1. The result was exactly the same as in Example 1.

(Comparative Example 1)
The same procedure as in Example 1 was performed except that an undercoat obtained by diluting the adhesive for nylon to 10% with MEK was used for the first layer without spraying, and spray coating was performed to a film thickness of 4.5 μm. Thus, an electromagnetic wave shield molding of Comparative Example 1 was obtained.

  Initial adhesion was greatly peeled at 50/100. The part to be peeled was between the undercoat and the metal film.

(Comparative Example 2)
Without blasting, a rubber-based adhesive (Konishi, Bond G103) that adheres well to an ABS or PC (polycarbonate) substrate in the first layer is diluted with MEK and used as an undercoat. An electromagnetic wave shielding molded article of Comparative Example 2 was obtained in the same manner as in Example 1 except that the spray coating was performed to 0.5 μm.

  The initial adhesion was greatly peeled at 80/100. The peel location was between the undercoat and the substrate.

(Comparative Example 3)
The same procedure as in Example 1 was performed except that an undercoat obtained by diluting the printing ink for nylon to 10% with MEK was used for the first layer without spraying, and spray coating was performed to a film thickness of 0.5 μm. Thus, an electromagnetic wave shield molding of Comparative Example 3 was obtained.

  The initial adhesion was greatly peeled off at 20/100. The part to be peeled was between the undercoat and the metal film.

(Comparative Example 4)
An electromagnetic wave shield molded article of Comparative Example 4 was obtained in the same manner as in Example 1 except that glass beads having a particle diameter of 700 μm were used as the abrasive.

  The surface resistance value of the electromagnetic wave shielding molded body obtained as described above was 0.6Ω, which was twice that of Example 1.

(Comparative Example 5)
An electromagnetic wave shielding molded article of Comparative Example 5 was obtained in the same manner as in Example 1 except that glass beads having a particle diameter of 20 μm were used as the abrasive.

  The initial adhesion was greatly peeled off at 30/100.

(Comparative Example 6)
A 50 mm × 50 mm base material (Mitsubishi Engineering Plastics Co., Ltd., Reny (registered trademark) 1022H) containing 50% by 50% each of polyamide resin and glass fiber was used.

  First, it was immersed for 60 seconds using chromic acid as an etching solution. Next, it was attached to an ion plating apparatus (AAIH-W36200SBT, manufactured by Shinko Seisakusho Co., Ltd.), a copper film was formed with a film thickness of 1 μm on the first layer, and a nickel film was formed with a film thickness of 0.2 μm on the second layer. .

  The initial adhesion was not peeled off, but the end of the substrate was lifted by about 1 mm and deformed.

Claims (18)

  A method for producing a molded body comprising subjecting a surface of a base material made of a hardly adhesive resin to blasting, and depositing a metal film on the surface subjected to blasting by vacuum deposition.   2. The molded body according to claim 1, wherein the blasting treatment is performed by spraying glass beads or ceramic fine powder having a particle diameter of 50 μm to 500 μm onto the surface of the substrate with air having a pressure of 0.196 MPa to 0.392 MPa. Production method.   The manufacturing method of the molded object of Claim 1 or 2 which obtains an electromagnetic wave shield molded object by forming into a film the film thickness of 0.5 micrometer-2 micrometers as said metal film.   A protective film made of nickel, nickel alloy, chromium, chromium alloy, Sn—Cu—Cr alloy, or Sn—Cu—Ni alloy having a thickness of 0.1 μm to 0.3 μm is formed on the copper film. The manufacturing method of the molding of Claim 3 which forms a film.   The manufacturing method of the molded object of Claim 4 which performs clear coating further on the said protective film.   As the metal film, a brightening film made of nickel, nickel alloy, chromium, chromium alloy, Sn—Cu—Cr alloy, or Sn—Cu—Ni alloy having a film thickness of 0.1 μm to 0.3 μm is formed. The method for producing a molded article according to claim 1 or 2, wherein a brightened molded article is obtained by forming a film.   The manufacturing method of the molded object of Claim 6 which further performs clear coating on the said brightening film.   An electromagnetic wave shield molded article comprising a base material made of a hardly adhesive resin and an electromagnetic wave shielding film directly formed on the base material.   The electromagnetic wave shielding molding according to claim 8, wherein the base material is made of any one of a polyamide resin, a polyamide resin containing glass fibers, a polyphenylene sulfide resin, a polyphenylene sulfide resin containing glass fibers, and a liquid crystal polymer resin. body.   The electromagnetic wave shielding molded body according to claim 8 or 9, wherein the electromagnetic wave shielding film is formed on a surface of the base material that has been previously blasted.   The electromagnetic wave shielding molded body according to claim 8, wherein the electromagnetic wave shielding film is made of a copper film having a film thickness of 0.5 μm to 2 μm.   A protective film made of nickel, nickel alloy, chromium, chromium alloy, Sn—Cu—Cr alloy, or Sn—Cu—Ni alloy having a thickness of 0.1 μm to 0.3 μm on the electromagnetic wave shielding film. The electromagnetic wave shield molded article according to claim 8, wherein:   The electromagnetic wave shielding molded product according to claim 12, wherein clear coating is further applied on the protective film.   A brightening molded body comprising a base material comprising a hardly adhesive resin and a brightening film formed directly on the base material.   The bright molding according to claim 14, wherein the base material is made of any one of a polyamide resin, a polyamide resin containing glass fibers, a polyphenylene sulfide resin, a polyphenylene sulfide resin containing glass fibers, and a liquid crystal polymer resin. body.   The brightening molded product according to claim 14 or 15, wherein the brightening film is formed on a surface of the base material that has been previously blasted.   The brightening film is made of nickel, nickel alloy, chromium, chromium alloy, Sn—Cu—Cr alloy, or Sn—Cu—Ni alloy having a thickness of 0.1 μm to 0.3 μm. 15. The brightened molded article according to any one of 15.   The bright molded article according to claim 17, wherein a clear coating is further applied on the bright film.