JP2001150602A - Laminated injection molded object and method of manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To further softly improve the touch of a surface rather hard in feel and relatively easy to slip while imparting anti-slip effect to this surface. SOLUTION: A laminated injection-molded object is constituted by laminating a laminated film 2, wherein a soft synthetic resin layer 21 and a hard synthetic resin layer 22 are strongly bonded, on the outer surface of an injection-molded resin layer 1 so that the soft synthetic resin layer 21 becomes a surface layer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminated injection molded article having a soft synthetic resin layer on the surface.

[0002]

2. Description of the Related Art In recent years, it has been demanded to improve the feel and the anti-slip effect by covering the outer surface of an injection-molded article such as a keyboard, a palm rest or a mouse of a personal computer with a soft synthetic resin layer. I have.

Further, a window is formed in an injection-molded article such as a control panel or a keyboard of an electric appliance, and the opening of the window is covered with a plastic film, and a switch operation is performed by pushing the plastic film with a finger. In some cases, there is a demand for improving the softness of the portion touched by a finger and improving the anti-slip effect.

[0004] On the other hand, conventionally, a plastic film is set in a molding die in advance, and a resin is injected into the molding die in this state, whereby the film is laminated on the surface of the obtained injection molded body. The so-called film insert molding is proposed, in which a base layer such as polyethylene terephthalate resin or polycarbonate resin is disposed on the front side and an adhesive layer is disposed on the back side. Injection molded articles have been proposed.

[0005]

However, in the above-mentioned conventional laminated injection-molded article, although the use of a film subjected to a printing treatment has the effect of giving an excellent surface appearance, the substrate appearing on the surface side Since the layer uses a hard resin such as polyethylene terephthalate resin or polycarbonate resin, it has a dislike that the touch is hard and relatively slippery, and it is desired to improve the touch of the surface more softly and to provide an anti-slip effect. I was

[0006]

Means for Solving the Problems The object of the present invention is to solve the above-mentioned problem by providing a laminated film formed by firmly bonding a soft synthetic resin layer and a hard synthetic resin layer to an outer surface of an injection molded resin layer. A laminated injection-molded article formed by laminating a soft synthetic resin layer on the surface, whereby an injection-molded resin layer having a soft touch on the surface and an excellent anti-slip effect can be obtained.

The present invention also provides a laminated film comprising a hard synthetic resin firmly adhered to one surface of a soft synthetic resin layer and a protective layer releasably laminated to the other surface of the soft synthetic resin layer. A method for manufacturing a laminated injection-molded article, comprising: setting a protective layer surface in an injection molding die toward a mold surface; and forming a synthetic resin layer by injection molding on a hard resin layer side of the laminated film. This makes it easy to handle the entire laminated film due to the rigidity of the hard synthetic resin layer, there is no risk of damaging the soft synthetic resin layer, the surface is soft to the touch, and the injection has excellent anti-slip effect. A molded resin layer can be obtained.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 1 is a schematic front sectional view showing an example of a laminated injection molded article of the present invention, and FIG. 2 is a schematic front sectional view for explaining an example of a method of manufacturing a laminated injection molded article of the present invention. .

According to the present invention, as shown in FIG. 1, a laminated film 2 formed by firmly bonding a soft synthetic resin layer 21 and a hard synthetic resin layer 22 to the outer surface of an injection-molded resin layer 1 is formed of a soft synthetic resin. It is a laminated injection-molded article formed by laminating the layers 21 so as to be on the surface.

In the present invention, the injection molded resin layer 1 is obtained by injection molding a resin such as a high impact polystyrene resin, an acrylonitrile-butadiene-styrene copolymer resin, or an acrylonitrile-styrene copolymer resin. .

In the present invention, the soft synthetic resin layer 21 may be any resin which has rubber elasticity and does not slip easily.
From the viewpoint of durability and appearance, silicone rubber is preferable as the material form. As the silicone rubber, a rubber such as an electron beam crosslinkable silicone rubber, a millable silicone rubber, and a liquid curable silicone rubber composed of a composition mainly composed of polydimethylsiloxane containing dimethylsiloxane as a main monomer component is preferable.

As other monomer components in polydimethylsiloxane containing dimethylsiloxane as a main monomer component, one or two methyl groups (one or three at the terminal) may be a vinyl group, a phenyl group,
Monomers substituted with (long chain) alkyl, fluoroalkyl, hydroxyl (= silanol), amino, glycidyl, alkoxy, chlorine, hydrogen, etc. can be used.

[0014] Characteristics that cannot be achieved with silicone alone, for example, a filler other than polydimethylsiloxane, a vulcanizing agent, and a property improvement for the purpose of assisting workability, heat resistance, mechanical properties, adhesion, flame retardancy, reliability, and the like. Components such as agents may be added.

As the filler, silica, diatomaceous earth, quartz powder, calcium carbonate, silicone resin, carbon and the like are used. Organic peroxides, modified silanes, modified siloxanes, alkoxysilanes, platinum compounds and the like are used as vulcanizing agents, and acetylene alcohol, cyclic methyl vinyl siloxane and the like are used as reaction inhibitors for adjusting curability. Examples of the property improver include a low-viscosity silicone oil / silicone resin containing a terminal silanol group or a terminal alkoxy group, a silane compound (the above processing aid),
Metal oxides such as iron and nickel, metal organic acid salts (above heat resistance improver), acid acceptors such as calcium oxide and barium oxide (above reversion inhibitor) platinum compounds, iron oxide, titanium oxide, carbon (more difficult) Flammability-imparting agents) silane coupling agents (above-mentioned adhesion improving agents) and the like are used.

The thickness of the soft synthetic resin layer 21 is as follows.
A thickness of 30 to 500 μm can be preferably used. If it is less than 30 μm, there is an anti-slip effect, but the softness is somewhat insufficient. If it exceeds 500 μm, there is a tendency to increase the material cost.

In the present invention, as the hard synthetic resin layer 22, polyethylene terephthalate, polypropylene,
A biaxially stretched film of polystyrene or the like can be used. Among them, a biaxially stretched film of polyethylene terephthalate is most preferable because it has high strength, high rigidity, and a rich clicking feeling and resilience when used for a switch.

In the present invention, as shown in FIG. 2, a hard synthetic resin layer 22 is firmly adhered to one surface of a soft synthetic resin layer 21 so that a protective layer 23 can be peeled off from the other surface of the soft synthetic resin layer 21. The laminated film 20 formed by laminating is set in the injection molding die 4 with the protective layer 23 surface of the laminated film 20 facing the mold surface 40 and injection molded on the hard synthetic resin layer 22 side of the laminated film 20. This is a method for producing a laminated injection-molded article, characterized in that an injection-molded resin layer 1 is formed.

In order to firmly adhere the hard synthetic resin layer 22 to one surface of the soft synthetic resin layer 21 and to laminate the protective layer 23 on the other surface in a releasable manner, for example, the hard synthetic resin layer 22 has a thickness of, for example, A 12 μm polyethylene terephthalate biaxially stretched film is coated with an adhesive primer having a polyurethane resin or an amorphous polyester resin as a main component and dried, and an uncrosslinked electron beam crosslinkable silicone resin is laminated thereon. Then, a protective layer 23 made of a biaxially stretched film of polyethylene terephthalate or the like is further pressed on the surface of the uncrosslinked silicone resin, and then the silicone resin is crosslinked and cured by irradiating with an electron beam to form a soft synthetic resin made of silicone rubber. A laminated film 20 having the layer 21 can be obtained.

It is sufficient that the protective layer 23 can be peeled off. A preferable peel strength is such that the protective layer 23 is fixed at a temperature of 20 ° C. and the protective layer 23 is perpendicular to the soft synthetic resin layer 21. When a so-called T-type peeling test was performed in which the film was peeled at a peeling speed of 300 mm / min in the direction, 30 to 500
gf / 50 mm width can be adopted.

The laminated film 20 thus obtained is set in the injection mold 4. At this time, the protective layer 23 of the laminated film 20 is set to face the mold surface 40 and the rigidity of the laminated film 20 is reduced. By forming the injection molded resin layer 1 by injection molding on the synthetic resin layer 22 side, the injection molded resin layer 1
Thus, a laminated injection-molded article firmly fused to No. 2 is obtained.

When the protective layer 23 located on the outermost surface of the obtained laminated injection molded article is peeled off, the soft synthetic resin layer 21
Are exposed, and a laminated injection-molded article having a soft touch to the surface and having an excellent anti-slip effect can be obtained.

Further, since the surface of the protective layer 23 is set to face the mold surface 40, there is an advantage that the soft synthetic resin layer 21 is protected and is not easily damaged.

At this time, a projection 42 for opening is formed on the injection side 41 of the injection mold 4 so that the injection-molded resin layer 1 does not contact the hard synthetic resin layer 22 at this portion. In the obtained laminated injection-molded article, an opening 10 is formed in the injection-molded resin layer 1, and the opening is formed in the laminated film 20.
Since it is molded in a closed state, it is possible to operate the switch by pushing the laminated film 20 from the surface, display by photoelectric, etc. Also, since the opening is sealed, water and dust do not enter. Because of its advantages, it can be used effectively for computer keyboards and home appliance operation boards.

In the present invention, as the protective layer 23, a biaxially stretched film made of a hard synthetic resin such as polyethylene terephthalate, polypropylene or polystyrene, a semi-rigid synthetic resin such as polyethylene or ethylene-vinyl acetate copolymer, or paper Silicone surface,
A material coated with a release material such as a fluorine-based material is used, but from the viewpoint of an appropriate peel strength for the soft synthetic resin layer, polyethylene terephthalate, polypropylene,
A biaxially stretched film made of a hard synthetic resin such as polystyrene is preferred, and a polyethylene terephthalate biaxially stretched film is particularly preferred.

[0026]

According to the present invention, the outer surface of the injection molded resin layer is
A laminated film formed by firmly bonding the soft synthetic resin layer and the hard synthetic resin layer, because it is a laminated injection molded body formed by laminating so that the soft synthetic resin layer is on the surface, the surface has a soft touch, Moreover, an injection-molded resin layer having an excellent anti-slip effect can be obtained.

Also, a laminated film formed by firmly bonding a hard synthetic resin to one surface of a soft synthetic resin layer and removably laminating a protective layer on the other surface of the soft synthetic resin layer is provided on the protective layer surface of the laminated film. Is set in the injection mold toward the mold surface, because it is a manufacturing method of a laminated injection molded body characterized by forming an injection molded resin layer by injection molding on the hard resin layer side of the laminated film, It is possible to obtain an injection-molded resin layer having a soft surface and a good anti-slip effect without fear of damaging the soft synthetic resin layer.

[0028]

The present invention will be described in detail below with reference to examples.

First, the hard synthetic resin layer 22 is prepared by applying a 12 μm-thick biaxially stretched polyethylene terephthalate film to an adhesive primer containing a polyurethane-based resin as a main component and drying it. As No. 23, an untreated biaxially stretched polyethylene terephthalate film having a thickness of 12 μm was prepared.

While sandwiching an uncrosslinked electron beam crosslinkable silicone resin between the two prepared films, the entire resin is sandwiched between a pair of rolling rolls so that the thickness of the silicone resin becomes 200 μm. Then, the silicone resin was cross-linked and cured by irradiation with an electron beam to obtain a laminated film 20 having a soft synthetic resin layer 21 made of silicone rubber.

Next, the obtained laminated film 20 was press-formed to form a predetermined shape having a small convex portion 201 and the like at a portion corresponding to a switch. At this time, despite being compressed by the press mold, the soft synthetic resin layer 21 is covered with the protective layer 23.
1 had the advantage that it was not damaged.

Further, the press-formed laminated film 20
In the injection mold 4 shown in FIG.
0, the injection side mold 41 is closed, and a molten acrylonitrile-styrene resin is injected through an injection hole 411 from an extruder (not shown), and injection molded on the hard synthetic resin layer 22 side of the laminated film 20. ,Cooling.

Then, the acrylonitrile-styrene resin is firmly fused to the hard synthetic resin layer 22 and is cooled and solidified to form the injection-molded resin layer 1, whereby a laminated injection-molded article is obtained.

Further, since the protective layer 23 is set with the surface of the protective layer 23 facing the mold surface 40, there is an advantage that the soft synthetic resin layer 21 is protected and hardly damaged in this injection molding step.

When the protective layer 23 located on the outermost surface of the obtained laminated injection molded article is peeled off, the soft synthetic resin layer 21
Is exposed, and as shown in FIG. 1, the laminated film 2 formed by firmly bonding the soft synthetic resin layer 21 and the hard synthetic resin layer 22 to the outer surface of the injection molded resin layer 1 is attached to the soft synthetic resin layer 21.
Can be obtained, and an injection-molded resin layer having a soft touch on the surface and an excellent anti-slip effect can be obtained.

At this time, the injection side 41 of the injection mold 4 is
If the injection-molded resin layer 1 is formed so as not to contact the hard synthetic resin layer 22 in this portion, the obtained laminated injection-molded article is formed in the injection-molded resin layer 1. The hole 10 is formed, but the opening is formed in a state of being closed by the laminated film 20, so that the laminated film 20 can be pushed in from the surface to operate a switch, display by a photoelectric signal or the like, and can be opened. Since the hole is sealed, there is an advantage that water and dust do not enter, so that the hole can be effectively used for a keyboard of a computer or an operation panel of a home appliance.

[Brief description of the drawings]

FIG. 1 is a schematic front sectional view showing an example of a laminated injection molded article of the present invention.

FIG. 2 is a schematic front sectional view for explaining an example of the method for producing a laminated injection molded article of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 injection molded resin layer 2 laminated film 20 laminated film 21 soft synthetic resin layer 22 hard synthetic resin layer 23 protective layer 4 injection mold 40 mold surface

Claims (2)

[Claims] 1. A laminated film formed by firmly bonding a soft synthetic resin layer and a hard synthetic resin layer on the outer surface of an injection-molded resin layer so that the soft synthetic resin layer faces the surface. Laminated injection molding. 2. A laminated film comprising a rigid synthetic resin firmly adhered to one surface of a soft synthetic resin layer and a protective layer releasably laminated to the other surface of the soft synthetic resin layer, wherein a protective layer surface of the laminated film is provided. Is set in an injection molding die toward a mold surface, and is injection-molded on the hard resin layer side of the laminated film to form a synthetic resin layer.