WO2002092329A1

WO2002092329A1 - Film adhering method

Info

Publication number: WO2002092329A1
Application number: PCT/JP2002/004064
Authority: WO
Inventors: Hideaki Takeda
Original assignee: Uchiya Thermostat Co., Ltd.
Priority date: 2001-05-11
Filing date: 2002-04-24
Publication date: 2002-11-21
Also published as: JP2002331587A

Abstract

A film adhering method capable of surely adhering a film with a melting temperature different from the melting temperature of a formed body with an adhered part of small area to the formed body without impairing the shape of the formed body, comprising the steps of placing a colorless transparent plastic film (6) on the thin-walled end face (5) of the formed body (1), placing a colorless transparent glass pane (7) on the plastic film, pressing the glass pane, and rotating the adhered part one turn while radiating laser beam (8) on the end face (5), whereby the end face (5) is molten at a radiated point (9) by the laser beam (8) transmitted through the glass pane (7) and the plastic film (6), and the plastic film (6) is adhered to the molten part.

Description

Description Bonding method Technical field

The present invention relates to a film bonding method, and more particularly to a bonding method for bonding a plastic film for the purpose of insulation or sealing to a plastic molded body such as an electric component.

Background art

Conventionally, when an insulating plastic film is bonded to a plastic molded body of a component body of an electric component or the like, a bonding method such as thermocompression bonding, ultrasonic welding, or bonding with an adhesive has been adopted.

In the bonding by thermocompression bonding, a plastic film generally called a heat seal film is used. This film is formed by laminating a thermoplastic resin having a melting temperature lower than that of the film body as an adhesive on the bonding surface. This is pressed while applying heat to the film bonding portion of the electrical component body, and the film body is bonded to the electrical component body.

Ultrasonic welding is a method in which the contact surface between the electrical component body and the film is melted by frictional heat generated by ultrasonic vibration to bond the two together. In addition, in the case of bonding with an adhesive, there are generally a method of bonding by a chemical reaction of the adhesive and a method of bonding by melting a bonded portion with a solvent.

However, the conventional film bonding method described above has some problems. For example, in the case of bonding by thermocompression bonding, 'If the surface wettability of the molded product is not good, the compatibility between the plastic molded product and the heat seal film is poor, and there is a problem that the adhesive strength is not obtained. In addition, thermocompression bonding is a method of melting and bonding not only by heating but also by applying a certain pressure.Therefore, in particular, plastic moldings with small shapes, In the case where the area of the bonding portion is small, as in the case of bonding, the deformation occurring in the bonding portion cannot be avoided. Therefore, when the area of the bonding portion is small, it is difficult to practically use the thermocompression bonding method. For thermocompression bonding, there is also a method in which both the plastic molded body and the film are melted and bonded.In this case, too, heating in one direction first melts the film that comes into contact with the heated body, and then contacts it. In this method, it is difficult to bond the two parts if the melting temperatures are not equal or close to each other. There was a problem that there was no degree of freedom in design due to severe restrictions on combinations. Also, in bonding by ultrasonic welding, this method melts the contact surface with the frictional heat of the contact surface, so if only one of them melts first, the frictional heat that melts the other will not be obtained and it will not be possible to bond Would. Therefore, also in this case, the two cannot be used unless the melting temperatures are the same. In addition, since friction heat is used, there is a problem that there is a restriction that a material having a small surface friction coefficient cannot be used.

As described above, in either case of thermocompression bonding or ultrasonic welding, if there is a large difference between the melting temperatures of the plastic molded body and the film, the bonding cannot be performed. In particular, in electrical parts, it is considered that one of the important properties is that the plastic molded body has heat resistance, so a combination of a molding material with a high melting temperature and a film with a similar or similar melting temperature is used. Finding was difficult. In addition, bonding with an adhesive is technically difficult when the plastic molded body is small or the area of the bonding portion is small, since an adhesive which is usually in a liquid state is applied to the bonding portion. In the case of an adhesive that causes a chemical reaction, there is a problem of gas generated during the reaction.In addition, in the case of an adhesive made of an organic solvent, it is difficult to set an appropriate coating amount that does not deform the bonded portion. is there.

In view of the above-described conventional circumstances, an object of the present invention is a combination of a plastic molded body and a plastic film made of materials having different melting temperatures, which has been difficult in the past, and a small area of the bonded portion on the plastic molded body side. Even in this case, it is an object of the present invention to provide a film bonding method for securely bonding without damaging the overall shape. Disclosure of the invention

The film bonding method of the first invention is a film bonding method for bonding a transparent or translucent plastic film to a plastic molded body, wherein the plastic film is placed on one surface of the plastic molded body, By irradiating the plastic molded body through the plastic film, the irradiated part of the plastic molded body by the laser beam is melted, and the plastic film is bonded by the fused part. You.

Then, for example, the plastic film is configured so that a portion of the plastic film that is in contact with the melted portion of the plastic molded body is melted together and bonded to the melted portion of the plastic molded body.

Next, a film bonding method according to a second invention is a film bonding method for bonding a transparent or translucent plastic film to a plastic molded body, wherein the plastic film is placed on one surface of the plastic molded body. Irradiating the plastic molded body with the laser light by passing through the plastic film, thereby heating a portion of the plastic molded body irradiated with the laser light; By melting the plastic film in contact with the portion, the plastic film is adhered to the plastic molded body.

And, for example, the plastic molded body is configured to be formed of a thermosetting resin.

In the film bonding method according to the first or second aspect, the laser beam has a wavelength in a range of, for example, 0.5 μπι to 1.5 Aim. In addition, the plastic molded body is configured to be formed of, for example, plastic whose melting temperature is higher than the melting temperature of the plastic film. In addition, the plastic film is printed, for example, on the outside of the bonding portion with the plastic molded body, after absorbing the laser light, and after the bonding with the plastic molded body, the printing is performed. By irradiating the laser beam to the part thus cut, the outside is cut off from the bonding part. In this case, the laser light is configured such that, for example, an output used at the time of bonding and an output used at the time of cutting are different.

Further, in the film bonding method of the first or second invention, for example, the plastic film is placed on the plastic molded body by placing a transparent plastic plate or a transparent glass plate on the plastic film. And the laser beam is transmitted through the transparent plastic plate or the transparent glass plate and the plastic film to irradiate the plastic molded body.

As described above, according to the present invention, a film having a different melting temperature from a transparent or translucent molded body is bonded to a highly heat-soluble molded body because the molded body is melted by transmitting the film using a laser beam. As a result, the degree of freedom in selecting the material of the molded body and the film is widened, and the design becomes easy and convenient.

In addition, since bonding can be performed using existing marking equipment, high speed and reproduction A good bonding process can be realized, improving production efficiency, and contributing to cost reduction.

In addition, since there is no occurrence of stress due to externally applied force or failure to spread the adhesive to unnecessary parts due to adhesion by laser beam irradiation, there is no possibility of deforming the molded body and breaking it, and therefore, The film can be easily bonded to small parts, which can contribute to expanding the use of small parts.

Also, by printing a pattern on the film using a color material that absorbs laser light, the film cutting process can be performed using the same marking device as the bonding process. This can contribute to improving productivity in this respect as well. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1A is a cross-sectional view showing a bonding state between a plastic molded body and a plastic film by a film bonding method according to an embodiment, and FIG. 1B is a plan view schematically showing the bonding state.

FIG. 2 is a diagram showing an example in which only a molded body is melted to form an adhesive portion. FIG. 3 is a diagram showing an example in which a bonded portion is formed by joining a molten portion of a molded body and a film melted by the heat of fusion to form a bonded body.

FIG. 4 is a diagram showing an example in which a colored film is used and the laser beam output is increased for irradiation. BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 (a) shows a plastic composition by a film bonding method according to one embodiment. It is sectional drawing which shows the adhesion | attachment process state of a form and a plastic film, and the same figure (b) is a top view which shows the adhesion state typically (the same figure (b) is the same thing as the same figure (a)). is not).

The plastic molded body 1 shown in FIG. 1A is, for example, a housing of a thermostat, in which a fixed contact 2 and a movable contact 3 of the thermostat which are opened and closed by using pie metal are housed. Indicates that the contact terminal 4 is drawn out. The overall size of the plastic molded body 1 is about 20 mm in length, 10 mm in width, and about 5 mm in height. .

In addition, as a material of such a plastic molded body 1, resin materials such as ABS, 66 nylon, PBT resin, PET resin, PPS resin, and liquid crystal polymer, which have relatively high melting temperatures, are suitable. Further, a thermosetting resin may be used, and in that case, a phenol resin, an epoxy resin, an unsaturated polyester resin, or the like may be used. Usually, these resin materials are formed into a desired shape by injection molding.

A plastic film 6 is placed on the thin end face 5 of the plastic molded body 1. As the material of the plastic film 6, a material that does not absorb laser light is selected. For example, colorless and transparent polyethylene, polystyrene, polypropylene, polyolefin, nylon, polyimide, vinyl chloride and the like can be mentioned. Of course, the material used is not limited to colorless and transparent as long as it does not absorb laser light, and may be colored and transparent or translucent.

It should be noted that although it is easier to work on the same plane where the films are bonded (hereinafter also referred to as welding), it is not necessary to limit the surfaces to the same plane as long as the film and the molded body can be brought into close contact with each other. In addition, when the bonding surfaces are the same as shown in FIGS. 3A and 3B, the plastic film 6 is prevented from drooping or falling out of the plastic molded body 1 and the plastic molded body is prevented from being deformed. (A) as shown in (a) of the figure, and place it on a plastic The glass plate 7 may be placed. Instead of the glass plate 7, a suitable non-colored and transparent plastic plate may be used.

In this state, the laser light 8 is irradiated vertically toward the end face 5. The irradiation light passes through the glass plate 7 and the plastic film 6 of the presser and is directly irradiated on the end face 5 of the plastic molded body 1. Then, the laser light 8 heats and melts the end face 5 at the irradiation point 9. In this way, while irradiating the irradiation point 9 of the end face 5, the irradiation point 9 is moved relatively to the end face 5, for example, to form a pattern 9 a set on the end face 5 as shown in FIG. Make a round along.

Thereby, the end face 5 of the plastic molded body 1 is melted according to the pattern 9a, fused to the plastic film 6, and solidified again. Thereby, the plastic film 6 is bonded to the plastic molded body 1. The width of the joint (adhesion) portion shown by the pattern 9a in FIG. 1B is extremely narrow, about 0.1 to 0.2 mm. Therefore, it is possible to adhere the plastic film 6 to a plastic molded body having a small joint area. Then, as described above, melting occurs on the climbing surface and bonding is performed by this melting, so that reliable bonding is performed.

In addition, an altered part 11 due to heating and melting is observed around the joint shown by the pattern 9a in FIG. 1 (b). This degree of alteration is observed in the plastic film 1 also in the plastic film. There is no adverse effect on 6. That is, there is almost no adverse effect such as deformation of the plastic molded body 1 or the plastic film 6 due to the adhesion.

In addition, since the width of the joining portion is as narrow as about 0.1 to 0.2 mm, the joining force may not be sufficiently strong as it is. If such higher strength or adhesive strength is required, the irradiation output is increased or the irradiation is performed by reciprocating movement at two or more places, preferably four places, in the entire circumference of the pattern, and the degree of melting is determined. To raise By doing so, it is possible to secure the mounting strength of the plastic film 6 film.

A marking device is used as the laser device used for irradiating the laser beam 8 described above. A laser device for marking (marking device) can be used with relatively low output when used for film bonding as described above. For example, when used for marking, the output is generally 1 OW (watt), but in this example, 1 W was sufficient when used for wearing. In addition, such a marking device can perform the bonding process in an extremely short time if the required bonding pattern (see pattern 9a in Fig. 1 (b)) is input as an operation parameter of the processing program. it can.

The laser beam 8 is preferably a laser beam having a property of transmitting a transparent material. According to experiments, the wavelength is 0.5 to 1.1 Aim, preferably 0.6 to 1.0 Aim. Laser light in the range of win is good. Such a laser beam is, for example, a YAG laser beam having a wavelength of 1.06 μπι.

In the example shown in the above-described bonding process of a plastic film (hereinafter simply referred to as a film), only a plastic molded body (hereinafter simply referred to as a molded body) is melted to form an adhesive portion. Depending on the melting temperature and the output intensity of the laser beam used, the film may melt and adhere. However, even when the film is melted in such a manner, the film is not melted by absorbing the laser light, but is heated and melted by the laser light, and the film is heated by the heat of the melted molded body. It melts.

In addition, when a film is continuously bonded to a plurality of molded bodies, it is necessary to sequentially cut the outer film after bonding, but such a work usually requires a troublesome and cumbersome process. By printing the pattern of the cut portion using a color that absorbs the laser beam in advance on the portion of the film to be cut, The film can be burned off simply by adjusting the output and irradiating according to the pattern. Hereinafter, what has been described above will be shown in the drawings.

FIG. 2 is a diagram showing an example in which only a molded body is melted to form an adhesive portion. The molded body 12 shown in the figure is a molded body of a liquid crystal polymer, and the film 13 placed on the upper surface thereof is a colorless and transparent polyethylene film. An example is shown in which a YAG laser having a wavelength of 1.06 / im is used and the irradiation point is moved from left to right as indicated by arrow A while irradiating in the vertical direction in the drawing.

As shown in the figure, melting marks 14 (14, 14a) of the molded body 12 due to the irradiation heat are observed. The slightly larger melting mark 14a near the irradiation start point is an excess melting mark formed by a short residence time from the start of irradiation to the start of movement. Altered portions 15 are observed around these melting marks 14 and 14a as in the case of Fig. 1 (b). In this state, the film 13 is bonded to the molded body 12 at the portion of the melting mark 14.

If a stronger bond strength is required, the moving speed is slowed down where necessary, and a surplus melt mark is formed as shown in 14a. can get.

FIG. 3 is a diagram showing an example in which a melted portion of a molded body and a film melted by the heat of fusion are bonded as a body. Also in this example, the molded product 16 is a molded product of a liquid crystal polymer, and the film 17 is a colorless and transparent polyethylene film. However, in this example, a polyethylene film whose melting temperature is slightly lower than that in the case of FIG. 2 is used. Also in this case, an example is shown in which a YAG laser having a wavelength of 1.06 μηι is used and the irradiation point is moved from left to right as indicated by arrow B while irradiating in the vertical direction in the drawing.

As shown in the figure, a melting mark 18 of the molded body 16 and a melting mark 19 of the film 17 melted and solidified by the heat of melting are observed. Pull this film 1 7 When peeled off, although not particularly shown, the molded body 16 and the film 17 are mutually melted and integrated at the molten trace 18 of the molded body 16.

FIG. 4 is a diagram showing an example in which a colored film is used and the output of the laser beam is increased for irradiation. The molded body 21 shown in the figure is also a molded body made of a liquid crystal polymer. Film 22 is a yellow transparent polyimide. Also in this case, a YAG laser having a wavelength of 1.06 / ini is used, and the irradiation point is moved from left to right as shown by arrow C while irradiating in the vertical direction in the drawing.

As shown in the figure, the irradiation mark 23 of the direct part a where the laser beam was directly irradiated on the molded body 21 was dissolved as a matter of course, but in the indirectly irradiated part b where the film 22 was superimposed, the molding was performed. Not only the body 21 but also the film 22 is melted and burned out, and the melted and deteriorated portions 24 on both sides of the irradiation mark 23 b are bonded to the formed body 21, respectively. In this way, instead of the transparent coloring, an opaque coloring that absorbs the laser light well is patterned on the outside of the welded portion and applied to the film, and the laser light is irradiated in accordance with this pattern. By baking off, unnecessary film outside the weld can be easily removed.

In FIGS. 2 to 4 described above, only one type of molded body (liquid crystal polymer) has been described for easy comparison of various changes. However, the molded body is not limited to the liquid crystal polymer, and is described above. ABS, 66 nylon, PBT resin, PET resin, PPS resin, etc. can be used. Further, the film is not limited to polyethylene or polyimide, but may be polystyrene, polypropylene, polypropylene, nylon, polyvinyl chloride, or the like, as described above. Further, the film is not necessarily transparent, and even if it is translucent, it is possible to obtain the function and effect of permeating the above-mentioned film and melting the molded body. Industrial applicability As described above, the film bonding method of the present invention is a film bonding method for bonding a plastic film for the purpose of insulation or sealing to a plastic molded body such as an electric component. It can be used in all industries where a plastic film is bonded to a molded product for insulation or sealing.

Claims

The scope of the claims

1. A film bonding method for bonding a transparent or translucent plastic film to a plastic molded body,

The plastic film is placed on one surface of the plastic molded body, and the plastic molded body is irradiated with laser light through the plastic film, thereby irradiating the plastic molded body with the laser beam. And fusing the plastic film with the melted part.

2. The film bonding method according to claim 1, wherein a portion of the plastic film that is in contact with the molten portion of the plastic molded body is melted together and bonded to the molten portion of the plastic molded body.

3. A film bonding method for bonding a transparent or translucent plastic film to a plastic molded body,

The plastic film is disposed on one surface of the plastic molded body, and the plastic molded body is irradiated with laser light through the plastic film to irradiate the plastic molded body with the laser light. A film bonding method, wherein the plastic film is bonded to the plastic molded body by heating and melting the plastic film in contact with the heating unit.

4. The film bonding method according to claim 3, wherein the plastic molded body is formed of a thermosetting resin.

5. The film bonding method according to claim 1, wherein the laser beam has a wavelength in a range of 0.5 μπι to 1.5 m.

6. The plastic molded body has a melting temperature of the plastic film 3. The film bonding method according to claim 1, wherein the film is formed of a plastic having a temperature higher than a temperature.

7. The plastic film is printed on the outside of the bonding portion with the plastic molded body so as to absorb the laser light, and after being bonded to the plastic molded body, the printed portion is formed. 3. The film bonding method according to claim 1, wherein an outer side is cut from the bonding portion by irradiating the laser beam.

8. The film bonding method according to claim 7, wherein an output of the laser beam used at the time of the bonding is different from an output used at the time of the cutting.

9. A transparent plastic plate or a transparent glass plate is placed on the plastic film so that the plastic film is fixed on the plastic molded body, and the laser beam is applied to the transparent plastic plate or the transparent glass. 3. The film bonding method according to claim 1, wherein the irradiation is performed on the plastic molded body through a plate and the plastic film.