JP4884755B2 - Gasket, manufacturing method thereof and construction method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a gasket which has excellent productivity and excellent workability when installing it in sealed part and makes up loss of material used as little as possible and realizes low cost. <P>SOLUTION: The gasket 20 includes a resin film 3 and an elastic body 4 formed to fuse on one side of the resin film 3. It is characterized in that the resin film 3 is punched along shape of the elastic body 4 or that of outside the elastic body 4. Method is capable of attaching the gasket 20 on attached surface while easily maintaining shape by the resin film 3. <P>COPYRIGHT: (C)2006,JPO&amp;NCIPI

Description

  The present invention relates to a gasket, a manufacturing method thereof, and a construction method thereof. In particular, gaskets for sealing between the lid and main body of hard disk (HDD) devices, gaskets for sealing between separators of fuel cells, gaskets for sealing communication devices such as mobile phones and OA devices, and other sealing purposes The present invention relates to a gasket, its manufacturing method and its enforcement method.

  In recent years, with the demand for downsizing and high performance of electronic devices, there is a demand for thinner components. In order to meet such demands, the casing body and lid of the electronic device are also made thinner, and as a result, the rigidity of each component tends to decrease. In order to cope with such a decrease in rigidity, a gasket for sealing purposes is also required to be thin, thin and soft.

  Since gaskets used in electronic devices are as thin as rubber bands, if a softer one is required, the handleability of the device becomes poor. For example, when a gasket is affixed to the lid of the HDD, positioning is difficult and workability is extremely poor. Several improvements for these are known as follows.

  Patent Document 1 states that “a central layer composed of a film or sheet of a rigidity-imparting resin layer, and a low-rigidity non-foamed rubber or non-foaming elastic plastic that is integrated on one surface of the central layer and has a lower hardness. It consists of an adhesive layer made of a film or sheet and an elastic layer made of rubber or elastic plastic foam that is integrated with the other surface of the central layer and has a lower hardness than the adhesive layer, and is punched out in a ring shape for packing. The “material” configuration is disclosed.

  Patent Document 2 describes a configuration in which “a sheet-like material is provided on one side of a gasket substrate formed of an elastic body, and the gasket substrate side is attached to a sealed portion with the gasket substrate side as an attachment surface, and then the sheet-like material is peeled” A sheet material is disclosed.

Japanese Patent Laid-Open No. 9-189362 JP 2003-120816 A

  However, the techniques disclosed in Patent Documents 1 and 2 have the following drawbacks.

  In Patent Document 1, the attachment property to the sealed portion is improved to some extent, but since it is punched from the laminated product, a loss occurs and dust increases. Loss cannot be regenerated and must be incinerated. In addition, a complicated production process is required to manufacture the laminated structure, and there is a disadvantage that the price is high.

  Moreover, in patent document 2, in order to make a sheet-like thing peelable from a gasket base material, a mold release process is needed for a film. When applied to an HDD gasket, cleanliness of the gasket is required, and silicone treatment cannot be performed as a peeling treatment, so a special and expensive film such as a fluororesin is required. Furthermore, since a laminated sheet composed of a sheet-like material and a gasket substrate is produced and punched into a predetermined shape, punching loss occurs. In addition, a gasket having a dome shape or the like cannot be produced, and only a quadrangular shape can be produced. Therefore, the hardness of the gasket cannot be reduced by adjusting the cross-sectional shape to reduce the compression area. Therefore, in Patent Document 2, it is unavoidable to cope with the problem by reducing the hardness of the material itself, and the degree of difficulty in reducing the hardness is high. As described above, the gasket material disclosed in Patent Document 2 has improved the mountability of the sealed portion to some extent, while realizing the reduction of the material used and the simplification of the manufacturing process while maintaining the performance. Challenges still remain.

  In addition, the packing material of Patent Document 1 and the gasket of Patent Document 2 are stamped products of different materials, and each gasket must be manufactured individually, and it is difficult to automate conveyance and assembly, so that it is easy to automate. A product form was desired.

  Accordingly, the present invention has been made to solve the above-mentioned problems, and (1) to provide a gasket that can be produced by an injection molding method with good productivity and also has good take-out properties from a mold, (2) Providing a gasket with good workability when applied to a sealed part, (3) Providing a gasket that uses a very general and inexpensive material, reduces loss as much as possible, and realizes low cost. (4 ) Even when the gasket is made of a soft foam, provide a gasket with good removability after injection molding, (5) Rational construction method when installing the gasket on the sealed part And (6) providing a gasket that can automate the production, transportation, and assembly of the gasket.

  The gasket of the present invention is a gasket having a resin film and an elastic body formed by fusion-bonding to one side of the resin film, along the shape of the elastic body or the outer shape of the elastic body. The resin film is cut.

  The elastic body is preferably made of a thermoplastic elastomer molded by injection molding. The injection molding may be insert injection molding. Insert injection molding refers to a molding method in which a resin is molded and fixed on one side of a film.

  An olefin resin film may be used for the resin film, and an olefin elastomer or a styrene elastomer may be used for the elastic body.

  A plurality of holes may be formed in the resin film.

  The gasket manufacturing method of the present invention is a method in which a roll-shaped or single-wafer resin film is continuously supplied to an injection mold, and an elastic body is continuously formed on the resin film by injection molding. The resin film is cut along a shape or a shape outside the elastic body.

  The elastic body is preferably made of a thermoplastic elastomer.

  An olefin resin film may be used for the resin film, and an olefin elastomer or a styrene elastomer may be used for the elastic body.

  Further, the gasket construction method of the present invention is a gasket having a resin film and an elastic body formed by fusing to one side of the resin film, the shape of the elastic body or the outside of the elastic body. The adhesive is applied to at least the entire circumference along the elastic body of the resin film surface of the gasket in which the resin film is cut along the shape, and is attached to the work surface.

  Further, the gasket construction method of the present invention is a method of continuously supplying a roll-shaped or single-wafer resin film to an injection mold, continuously forming an elastic body on the resin film by injection molding, The resin film is cut along a shape or an outer shape of the elastic body, an adhesive is applied to at least the entire circumference of the resin film surface along the elastic body, and the adhesive film is pasted on a construction surface. And

  As the adhesive, an olefin-based adhesive may be used.

  The adhesive may be an olefinic urethane reactive adhesive.

  Further, the gasket construction method of the present invention is a gasket having a resin film and an elastic body formed by fusing to one side of the resin film, the shape of the elastic body or the outside of the elastic body. The resin film of the gasket in which the resin film is cut along the shape is brought into contact with the work surface and heated.

  Further, the gasket construction method of the present invention is a method of continuously supplying a roll-shaped or single-wafer resin film to an injection mold, continuously forming an elastic body on the resin film by injection molding, The resin film is cut along a shape or a shape outside the elastic body, the resin film is brought into contact with a work surface, and heated.

  According to the present invention, since the gasket provided with the resin film as an integral body is provided, there is no deformation of the gasket at the time of construction, and workability is good, so that the construction cost can be kept low.

  Further, according to the present invention, it is possible to produce a gasket that is integrally provided with a resin film by injection molding, and it is possible to provide a gasket that has excellent mold release properties and extremely good productivity.

  Further, according to the present invention, a resin film can be continuously supplied and a gasket can be continuously manufactured, and an unmanned operation of the line can be realized, which is extremely efficient.

  In addition, according to the present invention, since the resin film surface of the gasket provided integrally with the resin film is bonded to the site to be sealed, extremely good sealing performance can be realized.

  In the present invention, an inexpensive resin film such as an olefin film can be used as the resin film, which is economical and the resin film and the elastic gasket are the same kind of resin. In addition, no harmful gases are generated when incinerated after disposal.

  In addition, according to the present invention, the fact that the resin film is a thermoplastic resin can be applied by thermal fusion, it is not necessary to use an adhesive, the productivity is high, and there is a concern about gas generation such as organic solvents. There can be provided a clean gasket.

  In addition, according to the present invention, since a plurality of holes are formed in the resin film, it is easy to transport the gasket using the holes, and positioning can be performed reliably when the gasket is attached to the work surface. As well as being able to automate the assembly.

  First, refer to FIG. FIG. 1 shows an injection molding apparatus 100 for producing the gasket according to the present embodiment of the present invention.

  The manufacturing method of the gasket of this Embodiment is as follows. First, a thermoplastic resin film 3 prepared in advance is placed in a mold composed of a fixed mold 1 and a movable mold 2. Subsequently, the thermoplastic elastomer of the elastic body, which is the raw material of the elastic body 4, is fused on one side of the resin film 3 by the injection molding machine 100 and insert-molded. After molding, the resin film integrated gasket 20 in which the elastic body 4 is formed on the resin film 3 from the molds 1 and 2 is removed. Here, the injection-molded elastic body may be referred to as a gasket.

  The elastic body 4 and the film 3 are fused by setting the mold in contact with the film 3 at a relatively high temperature so that the resin film is melted by the molten thermoplastic elastomer resin. For example, when polypropylene is used as the film 3, the mold temperature is preferably about 40 ° C. or higher, and the thermoplastic elastomer is preferably 180 to 230 ° C. at the cylinder temperature.

  For the film 3 placed in the mold, two to four or more than two gaskets can be taken.

  Further, when the elastic body 4 is formed by injection molding, it is preferable to devise air venting such as a gas vent so that a weld line is not easily generated.

  In order to mold a foam by injection molding, it is necessary to select a composition and a foaming agent suitable for foaming depending on the thickness of the product. In general, when the thickness is reduced to about 1 mm, it is better to use a nitrogen-based foaming agent, and when it is thicker, a carbon dioxide-based foaming agent can be applied. Further, a foam having a thick skin can be produced by slowing the injection speed during injection molding or lowering the mold temperature. After injecting the thermoplastic elastomer resin into the mold, it is preferable to reduce the mold clamping pressure or widen the clearance of the mold cavity after or during the injection as a method for promoting foaming.

  Reference is now made to FIG. In FIG. 2, the elastic body 4 is continuously formed on the continuous film 3 by using a continuous injection molding apparatus 101 capable of continuously injection-molding the elastic body 4 into the roll-shaped film 30. A continuously forming gasket continuous forming system is shown. According to this continuous molding system, the elastic body 4 can be produced in large quantities. Further, the elastic body 4 can be stored in a roll 31 as shown in FIG. The roll winding 31 in which the elastic body 4 is continuously formed on the continuous film 3 as shown in FIG. 4 can continuously form the elastic body 4 in a large amount at a high speed, and is very convenient for transportation and storage.

  FIGS. 3A and 3B respectively show an injection part of the continuous injection molding apparatus 101 of the gasket continuous molding system, a diagram viewed from the side of the molds 1 and 2, and a diagram viewed from the top. . The molds 1 and 2 are combined through four spacers 5 arranged at the four corners. The spacer 5 is substantially the same as the thickness of the film 3. In the gasket manufacturing method of this embodiment shown in FIGS. 2, 3-1, and 3-2, four elastic bodies 4 are formed on the film 3 at a time by injection molding. In addition, the number of the elastic bodies 4 formed at a time can be changed in a timely manner by changing the design of the molds 1 and 2.

  Reference is now made to FIG. FIG. 5 shows an example in which a film cutting device 102 is provided in the gasket continuous molding system shown in FIG. As shown in FIG. 5, after the elastic body 4 is continuously formed on the roll-wrapped film 30, the film 3 may be cut into a predetermined size without being wound up. In this case, wrinkling of the continuous film can be prevented.

  Further, the roll-wrapped resin film 30 is cut into a predetermined size in advance, and each cut film is supplied to the continuous injection molding machine 101 one after another, and the elastic body 4 is formed on each film one after another by insert molding. Thus, a single-wafer type continuous gasket forming system can be realized.

  A gasket continuous forming system using the roll-shaped resin film 30 and the single-wafer film makes it possible to manufacture a gasket with extremely high productivity.

  Next, the type of the resin film 3 will be described. The film used in the present embodiment is made of a thermoplastic resin, and examples thereof include polyolefin-based, polystyrene-based, polyester-based, polyamide-based, thermoplastic elastomer-based, polycarbonate-based, and polyimide-based materials. Select with. In order to prevent deformation of the film at the time of injection molding, the melting point or softening point of the film 3 is preferably 100 ° C. or higher.

  The adhesive force between the film 3 and the elastic body 4 can be controlled by appropriately selecting the type of film, the compatibility of the thermoplastic elastomer, and the injection conditions. For example, when the raw material of the elastic body 4 is an olefin elastomer or a styrene elastomer, an olefin film is preferably selected for the film 3. In particular, when a polypropylene, polyethylene, or polymethylpentene resin is selected as the resin having a melting point of 100 ° C. or higher, an appropriate adhesive force can be controlled in a wide range of conditions for injection molding.

  What is necessary is just to select the thickness of the resin film 3 including the rigidity, workability | operativity, and cost suitably, and about 50-200 micrometers is the most preferable.

  In order to control the fusion property and rigidity of the resin film 3, the resin film 3 may be composed of two or more layers, and the surface of the resin film 3 may be subjected to a treatment for adjusting the peeling force such as coating. These conditions are not essential. Further, the surface of the resin film 3 may be subjected to surface treatment such as corona discharge treatment or ultraviolet irradiation treatment.

  Next, the kind of thermoplastic elastomer which is a raw material of the elastic body 4 will be described. In this embodiment, an olefin elastomer, styrene elastomer, urethane elastomer, ester elastomer, polyamide elastomer, or fluororubber elastomer is used as the thermoplastic elastomer. Among these thermoplastic elastomers, olefin-based elastomers and styrene-based elastomers are preferred due to low moisture permeability, acid / alkali resistance, and low liquid permeability.

  Olefin-based thermoplastic elastomers have low moisture permeability, and are mostly resins made of olefinic hydrocarbons in the molecule, which can be obtained by kneading reaction of olefinic copolymer rubber and crystalline olefinic plastics, or olefinic monomers. The thing obtained by a synthetic reaction can be illustrated. As the olefin copolymer rubber, for example, a copolymer of propylene as ethylene and α-olefin, or a copolymer obtained by copolymerizing a non-conjugated diene component is preferably used. As the crystalline olefin plastic, a polymer or / and copolymer of α-olefin such as propylene is used. The kneading reaction can also be performed in the presence of a crosslinking agent or a crosslinking aid. The olefin-based olefin-based thermoplastic elastomer has a low moisture permeability and an excellent resilience, has a good moldability by injection molding, and is suitable as a material for the elastic body 4.

  The styrene thermoplastic elastomer is a resin obtained by kneading or kneading a hydrogenated styrene-butadiene copolymer or styrene-isoprene copolymer with an olefin resin. Examples of the styrene-butadiene or styrene-isoprene copolymer include those commercially available as so-called SBS or SIS block copolymers.

  Olefin-based thermoplastic elastomers are excellent in resilience at high temperatures, and styrene-based thermoplastic elastomers are excellent in resilience near room temperature, so these may be used in combination.

  When the elastomer material used in the present invention is a material that generates a large amount of gas, a baking process (a heat treatment process at a high temperature) may be provided to scatter the generated gas. This baking step may be performed at the raw material stage or after the elastic body 4 is molded. In addition, you may perform a baking process using a vacuum state together.

  Next, the construction of the gasket of the present invention in this embodiment will be described. In order to construct the gasket provided with the obtained resin film on the site to be sealed, the gasket is cut for each resin film (punched and processed), and an adhesive is applied and pasted to the resin film surface.

Reference is made to FIGS. In these FIGS. 6-1 to 6-4, the cutting process of the resin film according to the formation of the gasket of the present invention in the present embodiment is shown. In the present embodiment, the resin film 3 is cut (punched or processed) along the shape of the elastic body 4. Here, the cutting of the resin film 3 along the shape of the elastic body 4 is not limited to the case of cutting the resin film 3 without any difference from the shape of the elastic body 4, and the shape of the elastic body 4 is constant. This includes the case where the resin film 3 is cut with a margin added. The cutting of the resin film 3 includes punching with a mold, cutting with a knife or scissors, cutting with a water jet and other methods of cutting the resin film. FIG. 6A shows a state in which the elastic body 4 is formed on the resin film 3 . Here, the resin film 3 is cut (punched and processed) along the shape of the elastic body 4, the unnecessary resin film 3 is cut off as shown in FIG. 6-2, and the resin film 3 is cut off as shown in FIG. 6-3. The gasket 20 in which the elastic body 4 is integrated is completed. FIG. 6-4 is a cross-sectional view taken along line xx ′ in FIG. 6-3.

  Next, the gasket 20 is fixed to the work surface. Please refer to FIG. As shown in FIG. 7, an adhesive is applied to at least the entire circumference along the elastic body 4 of the surface of the resin film 3 of the gasket 20 of the present invention, and brought into contact with the work surface (sealed portion) 200 for fixing. Let This construction surface is, for example, the inner surface portion of the lid of the HDD. Since the gasket 20 of the present invention is a part of the resin film 3 and the entire periphery along the elastic body 4 and the work surface are in contact with each other through an adhesive, the sealing performance is very good.

  The type of adhesive is selected according to the type of resin film 3, but when an olefin-based film is used as the resin film 3, it is preferable to use an olefin-based adhesive. As such an example, a resin in which polypropylene, polyethylene, polyvinyl acetate is modified with a polar group such as acid modification such as maleic anhydride, epoxy modification or hydroxyl group modification is preferable. Among olefinic adhesives, olefinic urethane adhesives in which olefinic polyols, such as hydrogenated butadiene and hydrogenated isoprene-based polyols, are polymerized with diisocyanate, and olefinic polyols are oligomerized with diisocyanate and terminated. It is also preferred to use an olefinic urethane reactive adhesive that is isocyanate and hardened with moisture. A cyanoacrylate-based reactive adhesive can also be used. Among them, a reactive adhesive such as an olefinic urethane reactive adhesive is preferable as the solventless type. Olefinic films are inherently poor in adhesiveness. However, for example, when the gasket of the present invention is used for a lid of a HDD or a fuel cell, it is not necessary to have high adhesive strength because it is fixed with screws or the like after bonding. It is preferable that the resin film is firmly attached to the gasket and that the adhesive force is moderate because it is easy to peel off after use.

  In addition, it is preferable to use the fusion | bonding by the heat to a to-be-processed surface instead of an adhesive agent for adhesion | attachment with the resin film 3 and a to-be-processed surface (sealed part). This utilizes the fact that the resin film 3 is a thermoplastic resin, and bonds the resin film 3 and the work surface. In order to bond by the fusion method, the sealed portion may be heated, or the surface of the resin film 3 of the gasket 20 of the present invention may be heated. According to this fusing method, it is possible to provide a clean gasket 20 that does not require the use of an adhesive, is simple, and does not worry about gas generation.

  As described above, according to the gasket of the present invention in the present embodiment, since the gasket provided integrally with the resin film is provided, there is no deformation of the gasket at the time of construction, and workability is good, so the construction cost can be kept low. . Further, according to the gasket of the present invention in the present embodiment, a gasket integrally provided with a resin film can be produced by injection molding, and it is possible to provide a gasket with excellent mold release properties and extremely good productivity. In addition, since the gasket of the present invention is provided with a film, it is easy to handle and can be housed in a roll or cut into a predetermined size. Moreover, when the several hole is formed in the resin film, it can make it easy to automate conveyance of a gasket, and the assembly | attachment to a to-be-processed surface.

  According to the gasket manufacturing method of the present invention in this embodiment, it is possible to continuously supply a resin film and continuously manufacture the gasket, to realize an unmanned operation of the line, which is extremely efficient. Furthermore, it is extremely efficient in that the conveyance and assembly can be automated. Moreover, according to the construction method of the present invention in this embodiment, since the resin film surface of the gasket provided integrally with the resin film is bonded to the site to be sealed, extremely good sealing performance can be realized. In the present invention, an inexpensive resin film such as an olefin film can be used as the resin film, which is economical and the resin film and the elastic gasket are the same kind of resin. In addition, no harmful gases are generated when incinerated after disposal. Further, according to the construction method of the present invention, the fact that the resin film is a thermoplastic resin can be used for the construction by heat fusion, no adhesive is used, the productivity is high, and the organic solvent and the like are generated. A clean gasket free from gas concerns can be provided.

  Furthermore, the gasket according to the present invention can be automated by assembling a hole in a surface of a resin film corresponding to a bolt hole of an HDD cover, for example, an HDD cover. The punching of the resin film can be performed simultaneously with the punching of the resin film and the molding of the elastic body on the resin film by providing a punching die in the injection mold. This greatly streamlines the gasket assembly process and eliminates variations in gasket installation positions. In addition, the position which opens a hole in a resin film can use not only a bolt position but a filter hole. Such a hole making step may be performed in a resin film cutting step. Of course, applicable products include not only HDD gaskets but also fuel cells and mobile phones.

  Further, the gasket according to the present invention can be obtained by injection molding in the form of a continuous roll or in the form of a strip having a predetermined length. Next, the gasket is transported to the next process, such as the cleaning process and the bonding process. However, since the elastic body is molded and integrated into the resin film, it is unwinded and transported for roll products, and is adsorbed in vacuum for strip products. It is easy to automate the transfer of gasket products.

  Furthermore, since the gasket according to the present invention is formed by integrating an elastic body on a resin film, the resin film surface is adsorbed in a vacuum, for example, when applying an adhesive in the bonding process or at the time of thermal fusion. Is easy to fix, positioning becomes accurate and easy, and subsequent automatic assembly of the HDD cover is facilitated.

  Embodiments of the present invention will be described below in detail with reference to the drawings. In addition, the Example shown below is only the illustration which illustrates this invention suitably, and does not limit this invention at all.

In this embodiment, an example of manufacturing the gasket of the present invention will be described.
Please refer to FIG. FIG. 8 shows a cross-sectional configuration of the mold used in this example. The molds 1 and 2 are combined through four spacers 5 arranged at the four corners. The spacer 5 is substantially the same as the thickness of the film. Reference numeral 6 denotes a cavity. 7 is a space | gap, and the space | gap 7 plays the role of the resin film insertion port. The cavity 6 is an injection part of the elastic body 4. The gasket 20 according to the present invention includes a resin film 3 and an elastic body 4.

  The one shown in FIG. 8 was used as the mold of the continuous injection molding system shown in FIG. Molding could be performed continuously in a very short cycle. The resin used in this example is an olefin-based thermoplastic elastomer (MFR: ASTM 1238, 190 ° C., 2.16 kg load) 10 g / 10 min), at a cylinder set temperature of 200 ° C., fixed side and movable side molds. Was injection-molded into a clamped mold (injection conditions were injection speed: 200 mm / s, mold temperature: 40 ° C.). When the molded product was taken out from the mold, it was easy to remove the mold, and it was possible to produce a gasket molded product with a good molded state in which the thermoplastic elastomer was fused to the PP film. The gasket 20 including the molded resin film 3 can be wound into a roll as it is, or can be cut to a predetermined length by a film cutting device as shown in FIG.

  Next, in order to apply the gasket 20 provided with the obtained resin film 3 to the sealed portion, the gasket is cut (punched) for each resin film, and an adhesive is applied and pasted to the resin film surface.

  Refer to FIGS. 9-1 to 9-4. In these FIGS. 9-1 to 9-4, the cutting process of the resin film relating to the formation of the gasket of the present invention in this example is shown. In the present embodiment, the resin film 3 is cut along the outer shape of the elastic body 4. Here, cutting the resin film 3 along the shape of the outer side of the elastic body 4 is not only the case of cutting the resin film 3 without any difference from the shape of the outer side of the elastic body 4, but also of the elastic body 4. This includes the case where the resin film 3 is cut by adding a certain margin to the outer shape. The cutting of the resin film 3 includes punching with a mold, cutting with a knife or scissors, cutting with a water jet and other methods of cutting the resin film. FIG. 9A shows a state in which the elastic body 4 is formed on the resin film 4. Here, the resin film 3 is cut (punched and processed) along the outer shape of the elastic body 4, and unnecessary resin film 3 is cut off as shown in FIG. 9-2, and the film as shown in FIG. 9-3. The gasket 20 in which the elastic body 4 and the elastic body 4 are integrated is completed. 9-4 is a cross-sectional view taken along line xx ′ in FIG. 9-3.

  Next, the gasket is fixed to the work surface. Please refer to FIG. As shown in FIG. 10, an adhesive is applied to at least the entire circumference along the elastic body 4 of the surface of the resin film 3 of the gasket 20 of the present invention, and brought into contact with the work surface (sealed portion) 200 for fixing. Let In the present embodiment, this work surface is the inner surface of the lid of the HDD. The gasket 20 of the present invention has a very good sealing property because at least a portion of the entire circumference along the elastic body 4 of the surface of the resin film 3 and the surface to be processed are in contact with each other through an adhesive. .

  In this embodiment, the resin film 3 was cut along the outer shape of the elastic body 4, and a gasket in which the film 3 and the elastic body 4 were integrated was used. As a result, the loss of the resin film can be reduced, the internal sound of the HDD is hardly leaked to the outside, and a soundproofing effect is obtained.

  In this embodiment, the manufacturing process of the foam gasket will be described.

  A foam can be manufactured by mix | blending with a thermoplastic elastomer the thermal decomposition type foaming agent which thermally decomposes and generate | occur | produces gas. Specific examples of such a foaming agent include azodicarbonamide (ADCA), diethylazocarboxylate, barium azodicarboxylate, 4,4-oxybis (benzenesulfonylhydrazide), and 3,3-disulfonehydraside phenylsulfone. Examples thereof include organic foaming agents such as acid, N, N′-dinitrosopentatetramine, p-toluenesulfonyl hydrazide, and trihydrazinotriazine, and inorganic foaming agents such as sodium bicarbonate, ammonium bicarbonate, and ammonium carbonate. In particular, azodicarbonamide (ADCA), N, N'-dinitrosopentatetramine, and trihydrazinotriazine are preferable as the organic foaming agent, and sodium hydrogen carbonate is preferable as the inorganic foaming agent. Further, sodium bicarbonate and citric acid, monosodium citrate and sodium bicarbonate, monosodium citrate and glycerin fatty acid ester may be mixed and used. These foaming agents can be used singly or in combination, or in combination with a so-called decomposition aid.

  In the present invention, instead of foaming with a pyrolytic foaming agent, the resin can be foamed with butanes, pentanes, water or the like as a volatile solvent. Further, the gas itself can be dispersed or impregnated in the foamed resin base material, and in this case, carbon dioxide gas or nitrogen gas can be used as the foaming agent.

  Carbon dioxide gas generated by the reaction between sodium hydrogen carbonate and an acid, or carbon dioxide gas generated by an isocyanate compound and water can also be used. There is also a method in which moisture at a high temperature of a hydrate salt such as calcium sulfate or aluminum hydroxide is used as a foaming agent.

  The use of carbon dioxide gas, or foaming agents that release carbon dioxide through reaction or decomposition tend to form thicker skins, while nitrogen-based foaming agents tend not to form skins easily. Depending on the desired expansion ratio and composition, it can be used properly.

  In this example, a master batch was prepared by kneading 4 parts by weight of an inorganic foaming agent into TPO: olefin-based thermoplastic elastomer (MFR: ASTM 1238, 190 ° C., 2.16 kg load) 10 g / 10 min). This was injected into a mold in which a PP film was inserted into the mold at a cylinder set temperature of 200 ° C. and the fixed side and movable side molds were clamped (injection conditions were: injection speed: 200 mm / s, Mold temperature: 40 ° C.). When the foamed molded product was taken out from the mold, a foamed gasket molded product (foaming ratio: 1.5 times) that was easy to be removed and integrated into the PP film in an integrated state was produced.

  In this embodiment, a process of applying the gasket of the present invention to the HDD lid will be described.

  The film-integrated gasket produced in the above-described embodiment, Example 1 or Example 2 is punched into a gasket shape with a Thomson blade, and an olefinic urethane reactive adhesive is applied to the film surface of the product. It was adhered and fixed to the inner surface of the lid. This gasket was reacted and solidified with moisture in the air, and since it was a solvent-free type, it had a high degree of cleanliness and a very good sealing property.

  In this example, after setting the film-integrated gasket produced in the above-described embodiment, Example 1 or Example 2 on a gasket fixing jig, the PP film was heated on the surface of the HDD lid with an electric heater. The gasket fixed to the fixing jig was brought into contact with the lid of the heated HDD and fixed by heat sealing. The sealing property of the HDD lid equipped with the obtained gasket was good.

  In this example, a gasket 20 </ b> A having holes 40 at the diagonal corners of the gasket 20 provided with the resin film 3 manufactured in Example 1 was obtained. 11 and 12 are a perspective view and a plan view showing the gasket 20A, respectively. In addition, punching of the resin film 3 was performed simultaneously with the punching of the resin film 3 and molding of the elastic body 4 on the resin film 3 by providing a punching die in the injection mold.

  FIG. 13 is a schematic perspective view showing a state in which the HDD lid member 50 is assembled to the gasket 20A. In order to attach the lid member 50 to the gasket 20A, pins (not shown) corresponding to bolts were set up at four corners of a jig (not shown) for fixing the lid member 50. Next, the hole 51 of the lid member 50 is set to the pin of the jig, and further, the gasket 20A in a state where the hot melt adhesive is applied to the surface of the resin film 3 of the gasket 20A is set. The gasket 20A was assembled to the above. In the assembly to the lid member 50, the hole 40 of the resin film 3 played a role of alignment, and the positioning could be performed accurately, and there was no error. In addition, the productivity was very high due to good workability.

Note that four holes 40 in the resin film 3 and four holes 51 in the lid member 50 are provided, but six or more holes may be provided. Further, the position, shape and size of the holes 40 and 51 can be changed as appropriate.
For example, as shown in FIG. 14, in the gasket 20 </ b> B, the resin film 3 is also provided at the outer corners of the four corners of the elastic body 4, and holes 40 are formed in the resin film 3 at the outer corners. Also when the gasket 20B is assembled to the lid member 50, the hole 40 of the resin film 3 plays a role of alignment as in the above, and positioning can be performed accurately and workability is good. In FIG. 14, the resin film 3 is not provided on the inner periphery of the elastic body 4, but the resin film 3 may be provided on the inner periphery of the elastic body 4.

  In the above-described embodiment and Examples 1 to 5, the example in which the gasket of the present invention is applied to the lid of the HDD has been described. However, the gasket of the present invention and the method of applying the gasket are not limited thereto, and the lamp Packing for automobile lamps, gaskets for display portions of mobile phones, gaskets for liquid crystal displays of personal computers and mobile phones, gaskets for fuel cells, and other gaskets used for sealing purposes. Moreover, the gasket and its construction method of the present invention can also be used for an automobile air conditioner damper.

  As described in detail above, the gasket of the present invention, its manufacturing method and construction method can be produced by (1) a high-productivity injection molding method and can provide a gasket with good removal from a mold. (2) It is possible to provide a gasket with good workability when applied to the sealed part. (3) A gasket that realizes low cost by using as much general-purpose and inexpensive material as possible with as little loss as possible. (4) Even when the gasket is made of a soft foam, it is possible to provide a gasket with good removability after molding by injection molding, and (5) the gasket is sealed. Providing a reasonable construction method when installing and installing (6) providing a gasket that can automate the production, transportation and assembly of the gasket, It is very useful in industry in which basket.

It is a figure which shows one Embodiment of the injection molding apparatus 100 which manufactures the gasket of this invention. It is a figure which shows one Embodiment of the manufacturing method of the gasket of this invention. It is a figure which shows one Embodiment of the manufacturing method of the gasket of this invention. It is a figure which shows one Embodiment of the manufacturing method of the gasket of this invention. It is a figure which shows the roll winding of the gasket obtained by the manufacturing method of the gasket of this invention. It is a figure which shows one Embodiment of the manufacturing method of the gasket of this invention. It is the figure which showed the mode of the punching process of the resin film which concerns on manufacture of the gasket of this invention. It is the figure which showed the mode of the punching process of the resin film which concerns on manufacture of the gasket of this invention. It is the figure which showed the mode of the punching process of the resin film which concerns on manufacture of the gasket of this invention. It is the figure which showed the mode of the punching process of the resin film which concerns on manufacture of the gasket of this invention. It is the figure which showed the mode of construction to the lid | cover of HDD of the gasket of this invention. It is sectional drawing of the metal mold | die in one Example of the manufacturing method of the gasket of this invention. It is the figure which showed the mode of the punching process of the resin film of one Example which concerns on manufacture of the gasket of this invention. It is the figure which showed the mode of the punching process of the resin film of one Example which concerns on manufacture of the gasket of this invention. It is the figure which showed the mode of the punching process of the resin film of one Example which concerns on manufacture of the gasket of this invention. It is the figure which showed the mode of the punching process of the resin film of one Example which concerns on manufacture of the gasket of this invention. It is the figure which showed the mode of one Example of construction to the lid | cover of HDD of the gasket of this invention. It is a perspective view which shows the gasket which provided the hole of this invention. It is a top view which shows the gasket which provided the hole of this invention. It is a schematic perspective view which shows the state which attaches the cover member for HDD to a gasket. It is a top view which shows the gasket which provided the hole of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Fixed side metal mold | die 2 Movable side metal mold 3 Resin film 4 Elastic body 5 Spacer 6 Cavity 7 Space | gap 20, 20A, 20B Gasket 30 Roll wound resin film 31 Roll roll 40, 51 hole 50 Lid member 100 Injection molding machine 101 Continuous Injection molding apparatus 102 Film cutting apparatus 200 HDD lid

Claims (6)

A gasket in which an elastic body made of an olefin-based elastomer or a styrene-based elastomer is molded by injection molding at the same time as the other surface of the olefin-based resin film which is a surface to be bonded to the work surface. Because
The resin film is a continuous film from the outer periphery toward the center, and the outer periphery of the elastic body is cut along the outer shape of the elastic body and covered with the elastic body of the resin film. A gasket characterized in that a plurality of holes for positioning with respect to a work surface to which the gasket is assembled are formed in an unbroken portion. A method for manufacturing a gasket for obtaining the gasket according to claim 1,
Rolled or single-wafer olefin resin film is continuously supplied to the injection mold,
An elastic body made of an olefin-based elastomer or a styrene-based elastomer is continuously formed on the resin film by injection molding, and at the same time, the position of the resin film that is not covered with the elastic body is aligned with the work surface on which the gasket is assembled. Punching and forming multiple holes for
A method for manufacturing a gasket, comprising cutting the resin film along a shape outside the elastic body. A gasket construction method for attaching the gasket according to claim 1 to a construction surface,
Wherein an adhesive is applied to the entire periphery along at least the elastic body of the piece surface of the resin film, the construction surface the gasket with a plurality of holes formed in the resin film of the gasket of the gasket A gasket construction method characterized in that the gasket is aligned and attached to the construction surface.   The said adhesive agent is an olefin type adhesive agent, The construction method of the gasket of Claim 3 characterized by the above-mentioned.   The gasket construction method according to claim 3, wherein the adhesive is an olefin-based urethane reactive adhesive. A gasket construction method for attaching the gasket according to claim 1 to a construction surface,
The gasket is aligned with the work surface using a plurality of holes formed in the resin film of the gasket, the one surface of the resin film is brought into contact with the work surface, and heated to the work surface. A gasket construction method characterized by being bonded by fusing.

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