JP2004308340A - Handle made of plastic and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a handle made of plastics capable of solving the problem that a crack of a plating layer accompanying chromium plating can cause a danger to avoid a fear of an injury due to the crack in a surface layer in use and having a surface strength more excellent than the chromium plating and having a surface with various colors excepting a glossy-chromium metallic color, in the handle made of plastics, in which the surface is decorated with a metal, such as the handle for an automobile door. <P>SOLUTION: A hard coating layer such as a silicone resin is formed on the surface of a plastic molded form having the shape of the handle, and a layer composed of a metal (Ti, TiAl, Cr or the like) is formed on the hard coating layer by a sputtering. An ion plating is conducted while supplying a nitrogen gas and an acetylene gas on a sputtering layer composed of the metal, and a layer consisting of a hard metallic compound having the color of the metal such as TiN, TiC, TiCN, CrN, ZrN or TiAlN is formed on the surface. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to various handles made of plastic and having a metal decoration, and a method of manufacturing the same. Here, the “metal decoration” refers to a metal compound having a glossy or matte metallic appearance, such as gold, silver, bronze, gray and brown, depending on the metal compound. The term "handle" refers to a variety of handles, such as a handle on the inside or outside of a car door, a handle on a house door, a drawer for home or office furniture, and a handle for kitchen furniture. The handle may be stick-shaped or sticky, and may include knob-shaped or ring-shaped handles.
[0002]
[Prior art]
For example, handles used to open and close car doors used to be made of chrome-plated steel.In recent years, chrome-plated plastics and other metals have been added to plastic moldings to reduce weight and reduce costs. Has been replaced by a plated one. As a plastic, ABS resin having high impact strength and relatively low price is mainly used, but recently, AES resin is becoming effective. The AES resin is a copolymer of EPDM, which is a rubber of polyethylene, and acrylonitrile, and has better weather resistance than the ABS resin.
[0003]
For chromium plating on plastic molded products, usually, electroless plating of copper (5 to 20 μm thick) is first performed to create a base for electrolytic plating, and nickel is electrolytically plated thereon (5 to 20 μm thick), Finally, a procedure of performing electrolytic plating of chromium (thickness: 0.1 to 0.3 μm) is performed. This technology is well-established and can achieve bright chrome plating at low cost.However, it is difficult to make the plating thickness uniform for three-dimensionally complex shapes. In the case of a shape such as a handle of an automobile door, which has a certain curve and a bent portion at the tip, there is a problem in manufacturing that the thickness distribution is largely disturbed depending on the location.
[0004]
A problem with plastic plated products is that the plating layer has sharp cracks in the copper-nickel layer when the plastic molded article breaks, often resulting in injury to the toucher. Cracks in the plating layer may occur when a large impact is applied from the outside, even if the plastic molded product is not damaged. Furthermore, if the adhesion of the plating layer to the surface of the underlying plastic is not good, the plating layer may be peeled off at the interface and cracked in the plating layer even if the plastic molded product is not damaged.
[0005]
It is considered that a major cause of such peeling of the plating layer from the plastic surface is repeated temperature changes. Of course, in the case of an automobile door handle, it is needless to say that the handle outside the door is subjected to more severe conditions than the handle inside the door. Comparing the coefficients of thermal expansion to see the state of expansion and contraction caused by repeated temperature changes, there is a large difference between plastic and metal as follows. It is natural that peeling easily occurs at the interface between the plastic and the metal layer.
Material Coefficient of linear expansion (10 ⁻⁶ / K)
ABS resin about 80
Hard coat resin approx. 65
Copper 6.5
Nickel 13.3
Chrome 17.0
[0006]
In fact, some customers have been injured by breaking the plating on the handle of an automobile door. As a countermeasure, attempts have been made to apply a plastic coating to the outside of the plating layer, which has a certain effect in preventing injuries caused by damage to the plating layer. Even if a good material is used, there is a problem that it deteriorates after long-term use, and this measure is not practical for products such as automobile door handles.
[0007]
The applicant has previously attempted to improve a plastic faucet fitting provided with a metal decoration, and realized a metal faucet coated with a ceramic compound instead of metal plating, which has already been proposed. (Japanese Patent Application No. 2002-308658). The faucet fitting part is formed by forming a hard coat layer on the surface of a molded plastic article with a polyurethane paint, acrylic paint or silicone paint, providing a metal layer by sputtering, and then forming a metal compound layer by ion plating. It was formed. The technology relating to this faucet fitting was welcomed in the art, and when it was applied to a handle of a car door or a handle of furniture, a good result was also obtained.
[0008]
[Problems to be solved by the invention]
An object of the present invention is to apply the above-mentioned technology relating to faucet fitting parts to various handles made of plastic and having a metallic luster on the surface, and when the plating layer is broken with the conventional chrome plating. Eliminates the danger that the surface layer is broken during use and does not cause any injuries, has a surface strength that surpasses chrome plating, and has a surface of various colors other than glossy chrome metal color. It is an object of the present invention to provide a plastic handle that can be provided and a method of manufacturing the same.
[0009]
[Means for Solving the Problems]
The plastic handle having the metal decoration of the present invention, which achieves the above object, was formed by forming a hard coat layer, a metal layer formed by sputtering, and ion plating on the surface of a plastic molded product having various handle shapes. A metal compound layer is sequentially provided.
[0010]
The method of the present invention for producing a plastic handle having a metal decoration comprises forming a hard coat layer on the surface of a plastic molded article having the shape of a handle, then providing a metal sputtering layer, and performing ion plating thereon. And providing a layer of a metal compound.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
As plastics constituting a molded article having a handle shape, various commonly used materials, namely, nylon, polycarbonate, polyethylene terephthalate, polybutylene terephthalate, polycarbonate-polyethylene terephthalate copolymer, polycarbonate-polyethylene terephthalate copolymer, Select and use any of polycarbonate-polybutylene terephthalate copolymer, ABS resin, polycarbonate-ABS resin copolymer, acrylic resin, polystyrene, polyethylene, polypropylene, ASA resin, PES resin, PEEK resin, AES resin, etc. can do. Polycarbonate, ABS resin and AES resin are optimal. The molding method can be arbitrarily selected, such as injection molding, press molding, or a combination of extrusion molding and post-processing, but injection molding is most suitable.
[0012]
As the hard coat layer, a paint that gives a coating film having relatively high hardness is used. As a result, even if the hardness of the base material is low, it is possible to obtain a product in which the surface of the final product is hardly damaged. A commonly used polyurethane paint or silicone paint can be suitably used, and a coating film having a pencil hardness of H to 5H can be obtained. The hard coat layer prevents the influence of irregularities generated during molding on the surface of the plastic handle, thereby providing a metal decoration with a smooth surface, excellent appearance, and adhesion. The thickness of this layer is suitably selected in the range of 5 to 30 μm, and usually a thickness of 15 μm or less and about 10 μm is sufficient.
[0013]
As the metal layer formed by sputtering, a layer of Ti, TiAl intermetallic compound or alloy, Cr or Zr is useful. Sputtering techniques using these metals or alloys as targets are known and the sputtering layer on the hard coat layer may be formed accordingly. Forming the metal layer by sputtering has the advantage of making the adhesion of the ion plating layer formed on the metal layer extremely high.
[0014]
The technique of ion plating is also known, and it is possible to form a desired metal compound layer on the sputtering layer by combining the use of the sputtering target described above with the supply of a selected gas. it can. The supply gas is preferably N ₂ gas for forming nitride, acetylene gas for forming carbide, and (N ₂ + acetylene) gas for forming carbonitride. The metal to be sputtered and the metal of the metal compound formed by ion plating may be the same or different. Taking the latter example, a combination of providing a CrN ion plating layer on a Ti sputtering layer is possible.
[0015]
It goes without saying that the metal compound layer to be formed preferably has a beautiful appearance by itself and has high hardness. Specific metal compounds are TiN, TiC, TiCN, CrN, CrC, CrCN, ZrN, ZrC, ZrCN, TiAlN, TiAlC and TiAlCN.
[0016]
Embodiment 1
A handle material inside the automobile door having the shape shown in FIG. 1 was formed by injection molding of ABS resin. This handle material has a length of about 120 mm, a width of up to 30 mm and a thickness of up to 25 mm. A silicone-based coating material “X-41-2415” (manufactured by Shin-Etsu Chemical Co., Ltd.) was applied to the surface and dried to form a hard coat layer having a hardness of 3H. The thickness of this hard coat layer is about 10 μm. Sputtering using a chromium target (degree of vacuum: 2.0 × 10 ⁻³ Torr) was performed to form a 0.1 μm-thick chromium layer on the surface of the handle material. Then, ion plating was performed by supplying a nitrogen gas (pressure 5.0 × 10 ⁻³ Torr) into the sputtering apparatus to form a 0.25 μm thick CrN layer. In this way, an inner handle of an automobile door having a beautiful silver gray metal decoration was obtained.
[0017]
The following tests were conducted on the above-mentioned plastic door and inner handle of the automobile door having a metal decoration, and the following results were obtained.
[0018]
[Surface hardness test] JIS A4420
Pencil hardness 3H or more (The CrN layer has a substantial hardness of 2000Hv, so it is not easily scratched.)
[Adhesion test] JIS K5400
Cellophane tape peeling test: No peeling of squares with a cutter knife.
[Cas test] JIS H8502
24 hours: corrosion is not a problem at all because there is no coating film of a dissimilar metal.
[Heat cycle test] JIS H8630
After repeating a cycle of 1 hour in an atmosphere of 90 ° C. → 1 hour in an atmosphere of −20 ° C. 10 times, the state of adhesion was confirmed, and there was no problem.
[0019]
[Ball test]
A steel ball weighing 500 g was dropped from a height of 20 cm onto the inner handle of a car door placed horizontally. A dent was formed in the portion hit by the steel ball, but the surface layer followed the deformation, and no obvious cracking or peeling was observed.
[Tensile test]
Both ends of the inner handle of the automobile door were fixed, a steel wire having a thickness of about 1 mm was hooked at the center, and a load of 20 kg was applied for 1 minute. Although the part hit by the steel wire was dented, no clear cracking or peeling was found in the surface decoration layer.
[0020]
Embodiment 2
A material for a handle attached to a drawer of a unit kitchen having a shape shown in FIG. 2 was manufactured by insert injection molding of AES resin. The material of this handle is about 160 mm in length and 10 mm in thickness. A silicone-based paint “C-1175” (manufactured by NRC) was applied to the surface and dried to form a hard coat layer having a hardness of 2H. The thickness of this hard coat layer is about 10 μm. A titanium layer having a thickness of 0.1 μm was formed on the surface of the material of the handle by sputtering using a titanium target (degree of vacuum: 2.0 × 10 ⁻³ Torr). After that, ion plating was performed by supplying nitrogen gas (pressure 5.0 × 10 ⁻³ Torr) into the sputtering apparatus to form a TiN layer having a thickness of 0.2 μm. In this way, a drawer handle for the unit kitchen with a beautifully colored gold metal decoration was obtained.
[0021]
【The invention's effect】
According to the present invention, on a surface of various plastic handles, a simple method of sequentially performing hard coat-sputtering-ion plating is used to form a decorative film that is in close contact with plastic, and a metal compound on the surface is formed. Metal decoration can be performed by the coating. Various colors such as gold (TiN, ZrN), silver (TiC), bronze (TiCN), silver gray (CrN), and brown (TiAlN) can be realized by selecting a metal compound to be formed.
[0022]
This coating is in close contact with the plastic molded product, is less likely to crack, and has high safety. Considering the reason, the thickness of each layer is thin, the adhesion between them is good, and the coating film is formed by lamination of particles. First, the hard coat layer is a synthetic resin, and when applied to a material of a plastic molded product, the surface of the material swells and adheres, so that the hard coat layer is well integrated. On top of this, there is a metal layer in which metal particles deposited by sputtering are stacked, and a metal compound layer is formed thereon by ion plating in a continuous form. Such a configuration has a function of absorbing or buffering expansion and contraction in the plane direction due to a temperature change.
[0023]
The metal decorative layer of the present invention has a thin metal layer formed by sputtering with a thickness of 0.1 μm or less, and a metal compound layer formed by ion plating has a thickness of about 0.2 μm. , It is much thinner than the thickness of the metal layer (10 to 40 μm in total) constituting the conventional bright chrome plating. It will be readily appreciated that when a plastic substrate expands and contracts due to temperature changes, a thinner (metal / metal compound) layer will follow more easily than a thicker metal layer.
[0024]
The chrome plating in the prior art is thick as described above, and forms a clear interface with the plastic layer of the base material and adheres to the chromium plating. Peel off at the interface or interface between the metal layer and the plastic. Since the plating is hard, the fractured surface tends to become an acute angle. On the other hand, the metal layer formed by sputtering according to the present invention is a so-called powdery separation even if the metal layer is separated from the plastic layer due to an external impact or the like because the particles are accumulated. Therefore, no sharp fracture surface is formed. For this reason, the plastic handle of the present invention is a component that is safe, has high durability, and can be provided at low cost.
[Brief description of the drawings]
FIG. 1 is a view showing the shape of an inner handle of an automobile door manufactured in Embodiment 1 of the present invention, wherein A is a plan view and B is a longitudinal sectional view.
FIG. 2 is a view showing a shape of a drawer handle of a unit kitchen manufactured in Example 2 of the present invention, wherein A is a plan view and B is a transverse sectional view.

Claims (6)

A plastic handle having a metal decoration, in which a hard coat layer, a metal layer formed by sputtering, and a metal compound layer formed by ion plating are sequentially provided on a surface of a plastic molded article having a handle shape. The plastic constituting the molded article having the handle shape is nylon, polycarbonate, polyethylene terephthalate, polybutylene terephthalate, polycarbonate-polyethylene terephthalate copolymer, polycarbonate-polybutylene terephthalate copolymer, ABS resin, polycarbonate-ABS resin copolymer The plastic handle according to claim 1, wherein the handle is selected from the group consisting of coalesced resin, acrylic resin, polystyrene, polyethylene, polypropylene, ASA resin, PES resin, PEEK resin and AES resin. The plastic handle according to claim 1, wherein a polyurethane coating, an acrylic coating, or a silicone coating is used as the hard coat layer. The plastic handle according to claim 1, wherein the metal layer formed by sputtering is a layer of Ti, TiAl alloy, Cr or Zr. The plastic handle of claim 1, wherein the metal compound layer is a layer of TiN, TiC, TiCN, CrN, CrC, CrCN, ZrN, ZrC, ZrCN, TiAlN, TiAlC or TiAlCN. Forming a hard coat layer on the surface of a plastic molded product having a handle shape, then providing a metal sputtering layer, and performing ion plating on the metal coating layer to provide a metal compound layer Manufacturing method of the handle.

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