JPH09254293A - Seal material and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the generation of vapor of an org. solvent at a time of use while holding a shape by successively laminating a first foam layer, a reinforcing layer and a second foam layer and directly bonding the reinforcing layer to the first and second foam layers. SOLUTION: Release paper 5 is continuously supplied to an endless belt conveyor 2 and a soft polyurethane foam raw material is continuously emitted to the surface of the release paper 5 from an emitting port 4 to form a soft polyurethane foam raw material layer 12. Thereafter, a polyester film 11' is continuously supplied to the raw material layer 12 and the soft polyurethane foam raw material is continuously emitted to the surface of the film 11' from an emitting port 3' to form a soft polyurethane foam raw material layer 13. Thereafter, this three-layered laminate is heated to react and cure the soft polyurethane foam raw material to set the first raw material layer 12 and the second raw material layer 13 to first and second foam layers.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sealing material used as a gasket, packing, etc., and a manufacturing method thereof. INDUSTRIAL APPLICABILITY The sealing material of the present invention has excellent shape-retaining properties, is extremely easy to handle, and is suitable as a sealing material for electronic devices, precision devices and the like.

[0002]

2. Description of the Related Art Electronic equipment, precision equipment and the like are assembled with a gasket interposed between a main body and an upper lid.
In recent years, as the main body of electronic equipment, precision equipment and the like has become thinner and lighter, a gasket that is thin and soft has been required. As a material forming such a gasket, a foam having excellent flexibility has been conventionally used. In particular, polyurethane foam is widely used, which does not cause fatigue even after long-term use.

However, although the gasket made of a thin and soft polyurethane foam is excellent in sealing property, it is inferior in the property of retaining the shape. Therefore, it is reinforced with an adhesive tape for easy handling. Particularly, in the case of an adhesive tape using a strong base material such as a polyester film, the shape retention property is further enhanced. Further, in order to fix this gasket, which is inferior in shape retention property, to a predetermined position of the main body or top lid of an electronic device or the like, it may be temporarily fixed with an adhesive tape.

If the thin and soft gasket itself has a shape-retaining property, it is not necessary to strengthen it with an adhesive tape. As such a gasket, for example, one in which a layer made of polyurethane foam is joined to one side or both sides of a metal sheet has been proposed. Then, the metal sheet and the polyurethane foam are generally joined by a pressure sensitive adhesive or an adhesive or a pressure sensitive adhesive tape.

[0005]

However, in the case of using the gasket in which the metal and the foam are joined as described above, it may be due to the heat generation of electronic equipment, precision equipment, etc. Vapors of organic solvents may be generated. Then, this steam may cause troubles to internal parts. Most of the steam generated from this gasket is generated from a pressure-sensitive adhesive, an adhesive, or a pressure-sensitive adhesive tape that bonds metal and foam. Therefore, it is desired to develop a sealing material such as a gasket that has excellent shape-retaining characteristics and does not generate harmful vapor.

The present invention solves the above-mentioned problems, and since the sealing material itself has a shape-holding property and does not use adhesives, adhesive tapes, etc. An object of the present invention is to provide a sealing material that does not generate steam and a method for manufacturing the same.

[0007]

The sealing material of the first invention is
A first foam layer, a reinforcing layer and a second foam layer are laminated in this order, and the reinforcing layer is directly bonded to the first foam layer and the second foam layer. It is characterized by being. The sealing material of the second invention is characterized in that at least one of the first foam layer and the second foam layer is made of flexible polyurethane foam.

The method of manufacturing the sealing material of the third invention is
The first foaming raw material is supplied to one surface of the reinforcing material continuously supplied to form a first foaming raw material layer, which is reacted and cured to form a first foam layer, and at the same time, the above-mentioned reinforcing material One surface is joined to the first foam layer, then the two-layer laminate is continuously supplied, and the second foaming raw material is supplied to the other surface of the reinforcing material to form the second foaming material. A foaming raw material layer is formed, reacted and cured to form a second foam layer, and at the same time, the other surface of the reinforcing material and the second foam layer are bonded to each other to obtain a predetermined shape from a laminate of three layers obtained. Is obtained.

Further, according to the fourth aspect of the present invention, a sealing material is used.
It is a method of continuously producing layers. That is, the first foaming raw material is supplied to the surface of the mold release material that is continuously supplied to
The foaming raw material layer is formed, and then the reinforcing material is continuously supplied to bring it into contact with the first foaming raw material layer, and then the second foaming raw material is supplied to the other surface of the reinforcing material. Second foaming material layer is formed, and then the first and second foaming material layers are reacted and cured to form a foam layer, and at the same time, the reinforcing material, the first foam layer and the second foam layer are formed. It is characterized in that a sealing material having a predetermined shape is obtained from the three-layer laminate obtained by joining the foam material layer with each other.

Generally, the seal material is roughly classified into a gasket which is a fixed seal material and a packing which is a motion seal material. The "sealing material" of the present invention can be used as a gasket or a packing.
If a thin metal plate is used as the reinforcing material in the present invention, a product corresponding to a semi-metallic gasket can be obtained.

The above-mentioned "reinforcing layer" is preferably a thin layer so that the sealing material functions sufficiently and the excellent flexibility of the sealing material is not impaired. The thickness depends on the rigidity of the reinforcing material forming the reinforcing layer, but when the reinforcing material is a thin metal plate, it is several tens to 100 μm, particularly 10 to 7 μm.
About 0 μm is preferable. In addition, the reinforcing material is a resin film,
In the case of paper or the like, although depending on the kind, it is preferably several tens of μm to 500 μm, and particularly preferably about 100 to 250 μm.

As the "reinforcing material", metal foil such as stainless steel foil and aluminum foil can be used. Further, a film made of a general-purpose resin such as polyolefin, polyester, polyamide, or polyvinyl chloride can also be used. In addition, ordinary paper, paper reinforced with resin fibers and the like can be used, but metal foil or resin film excellent in durability and the like is preferable. These reinforcing materials are suitable for the continuous manufacturing method as in the third and fourth inventions.

The "first foam layer" and the "second foam layer" may be made of the same type of foam,
It may consist of different types of foam. Further, the type of foam may be appropriately selected depending on the type of seal material, the application, and the like. The foam layers may have the same thickness or different thicknesses, as long as the total thickness of the sealing material is about the same as that of a conventional product of this type.

The above "first foaming raw material" and the above "second foaming raw material" can be continuously supplied in a liquid state, and after being brought into contact with the reinforcing layer, they are appropriately heated if necessary. It is preferable to use a raw material that can be reacted and cured by, for example, a raw material of flexible polyurethane foam. In addition, the above-mentioned polyurethane foam raw material is particularly preferable in the point that a sealing material having more excellent adhesiveness and less settling can be obtained in applications such as the sealing material of the present invention in which the reinforcing material is laminated and bonded.

The polyurethane foam is obtained by mixing a polyol component containing a polyol, a foaming agent, a catalyst, a foam stabilizer and the like with an isocyanate component, reacting and curing the mixture.
As the polyol, a polyether polyol is usually used. Further, polyester polyol, polycarbonate polyol, polydiene-based polyol and the like can also be used. These polyols may be used alone or in combination of two or more.

As the isocyanate, those generally used in the production of polyurethane foam can be used without particular limitation. For example, TDI, MDI
Also, a mixture of TDI and MDI, or a modified product of MDI, TDI, or the like can be used.

As other raw material components, water is mainly used as a foaming agent in chemical foaming, but dichloromethane or the like can be used together for the purpose of suppressing heat generation. As the catalyst, organotin compounds such as stannas octoate, dibutyltin diacetate, dibutyltin dilaurate are mainly used. It is also possible to use a relatively small amount of an amine catalyst, especially a tertiary amine. Further, as the foam stabilizer, a block copolymer of dimethylpolysiloxane and polyether is usually used. In addition,
A colorant, a filler, and the like can be blended as necessary.

In the present invention, the flexible polyurethane foam constituting the foam layer can be produced by chemical foaming, foaming with a volatile solvent or the like. Alternatively, it may be generated by physical foaming, for example, a mechanical floss method in which an inert gas is mechanically mixed. In the present invention, the mechanical floss method is particularly preferable.

In the mechanical floss method, an inert gas is mixed in the foam raw material. Therefore, when the raw material is discharged onto the surface of the reinforcing material to form a raw material layer having a predetermined thickness and then reacted and cured, there is little change in thickness before and after the reaction and curing.
On the other hand, in the chemical foaming method, since the foaming agent is chemically generated during the reaction and curing, the change in thickness before and after the reaction and curing is large, and the accuracy of the thickness of the foam layer formed is reduced. In the foaming method in which the change in thickness is large as described above, it is particularly difficult to continuously form three layers as in the fourth invention.

The sealing material of the present invention is characterized in that the reinforcing layer and the foam layer formed on both surfaces thereof are directly bonded. This direct means that no layer such as a pressure-sensitive adhesive, an adhesive or a double-sided pressure-sensitive adhesive tape for joining both layers is interposed between the reinforcing layer and the foam layer. Therefore, in the sealing material of the present invention, unlike the conventional reinforced sealing material, there is no problem that vapor such as an organic solvent is generated from the adhesive, the adhesive or the like while being used as a gasket or the like. .

As described above, the sealing material of the present invention does not use any adhesive or the like. Therefore, it is not possible to bond the foam, which has been reacted and cured, to the reinforcing material. Therefore, it is necessary to bring the foam raw material into direct contact with the surface of the reinforcing material, and to react and cure in that state. Although various methods such as a compression molding method can be considered as such a method, a continuous method such as the third and fourth inventions is more preferable because the production efficiency is low in the batch method.

In the manufacturing method of the third invention, since a two-layer product is once molded and then the same operation is repeated to form a three-layer product, it is a continuous system, but the productivity is not so high. In addition, it is necessary to take care so that the foam layer formed earlier is not damaged in the subsequent process. However, the device is simple and easy to operate. On the other hand, in the manufacturing method of the fourth aspect of the present invention, a three-layer product is molded at one time, so the productivity is considerably high. However, the apparatus becomes complicated and the operation becomes complicated, and it is necessary to carefully manufacture the foam layer to obtain a foam layer having a predetermined thickness.

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION A weight ratio of 100 parts by weight of a polyether polyol (average molecular weight: 3000, hydroxyl value: 43), 0.1 part by weight of a metal catalyst (stannas octoate) and 3 parts by weight of a silicone foam stabilizer. So that the polyol component was continuously flowed into the mixing head. Further, the foaming agent (inert gas) was mixed into the polyol component immediately before flowing into the mixing head at a flow rate of 0.1 NL / min.

At the same time, polyisocyanate (crude MDI, NCO content; 31%) was flown into the mixing head so that the isocyanate index was 1.00. Then, the foaming raw material mixed in the mixing head was supplied to an oak mixer, a nozzle with a narrowed tip, and the like, and was discharged onto the surface of the reinforcing material or the release paper.

An embodiment of the present invention will be described below with reference to FIG. FIG. 1 is a schematic diagram showing a vertical cross section of an apparatus for manufacturing a sealing material by the manufacturing method of the third invention, and a step of forming a two-layer laminate of a reinforcing material and a first foaming raw material. In FIG. 1, 11 is a reinforcing layer made of a polyester film, 12 is a soft polyurethane foam raw material layer, and 11 'is a reinforcing material made of a polyester film. Further, 2 is an endless belt conveyor, 3 is an outlet of an Oaks mixer, and 4 is a doctor blade.

On the endless belt conveyor 2, a 125 μm-thick polyester film 11 ′ was continuously supplied in synchronization with the moving speed of the conveyor 2. Then, on the surface of the film 11 ', the above-mentioned flexible polyurethane foam raw material was continuously discharged from the discharge port 3 of the Oaks mixer, and the thickness of 0.8 mm was obtained by the doctor blade 4.
This was used as the flexible polyurethane foam raw material layer 12.

Thereafter, this polyester film 11 '
A two-layer laminate consisting of the raw material layer 12 and the raw material layer 12 is heated in a drying oven (not shown) at 160 ° C. for about 3 minutes to react and cure the flexible polyurethane foam raw material, and the reinforcing layer and the first foam layer. A two-layer laminate consisting of and was obtained.

Although the subsequent steps are not shown, the laminate obtained as described above is once wound on a drum,
Then, the two-layer laminate was fixed at the position where the polyester film was attached and continuously supplied. Then, the same operation as above was repeated to form a second flexible polyurethane foam raw material layer having a thickness of 0.8 mm on the other surface of the polyester film.

Thereafter, a three-layer laminate comprising the polyester film, the first foam layer and the second raw material layer is heated by the same apparatus and conditions to react and cure the second raw material layer. To give a second foam layer. There was no change in thickness between the raw material layer and the foam layer after reaction and curing. The three-layer laminate molded in this manner was punched into a predetermined shape to obtain a gasket.

Another embodiment of the present invention will be described below with reference to FIG.
It will be explained by. FIG. 2 is a schematic view showing a longitudinal section of an apparatus and a process when a sealing material is manufactured by the manufacturing method of the fourth invention. In FIG. 2, 1 is a sealing material, 11 is a reinforcing layer made of a polyester film, 12 and 13 are soft polyurethane foam raw material layers, 11 'is a reinforcing material made of a polyester film, and 5 is a release paper. Also, 2
Is an endless belt conveyor, 3 and 3'are outlets of an Oaks mixer, and 4 and 4'are doctor blades.

The release paper 5 is continuously supplied onto the endless belt conveyor 2 in synchronism with the moving speed of the conveyor 2. On the surface of the release paper 5, the above-mentioned soft polyurethane foam raw material is mixed with the Oaks mixer. It is continuously discharged from the discharge port 4 of, and the thickness is 0.8 m by the doctor blade 5.
m was used as the flexible polyurethane foam raw material layer 12. After that, on the raw material layer 12, the polyester film 1 having a thickness of 125 μm is also synchronized with the moving speed of the conveyor 2.
1'was fed continuously. And this film 11 '
Further, the above-mentioned flexible polyurethane foam raw material is continuously discharged onto the surface of
A 0.8 mm thick flexible polyurethane foam raw material layer 13 was formed by a doctor blade 4 '.

Thereafter, the three-layer laminate is heated in a drying oven (not shown) at 160 ° C. for about 3 minutes to react and cure the flexible polyurethane foam raw material, and the first raw material layer 12 and the second raw material layer 12 are mixed. The raw material layers 13 were the first and second foam layers, respectively. There was no change in the thickness between the raw material layer and the foam layer after reaction and curing. The three-layer laminate molded in this manner was punched into a predetermined shape to obtain a gasket.

[0033]

EFFECTS OF THE INVENTION In the sealing material of the first invention, even though the constituent material is thin and soft, the sealing material itself has a shape-retaining property, and the reinforcing layer and the foam layer do not use an adhesive agent or the like. Since it is directly bonded, vapor such as organic solvent is not generated during use. Further, according to the manufacturing method of the third invention and the fourth invention, the specific sealing material of the first invention can be easily and continuously manufactured by an apparatus and an operation usually used for manufacturing a laminate. .

[Brief description of drawings]

FIG. 1 is a schematic view showing an outline of a device and a process up to the middle of a process when the sealing material of the present invention is manufactured by the method of the third invention.

FIG. 2 is a schematic diagram showing an outline of an apparatus and a process when the sealing material of the present invention is manufactured by the method of the fourth invention.

[Explanation of symbols]

1; sealing material, 11; reinforcement layer made of polyester film, 11 '; reinforcement material made of polyester film,
12, 13; flexible polyurethane foam raw material layer, 2; endless belt conveyor, 3 and 3 ', outlet of Oaks mixer, 4 and 4', doctor blade, 5; release paper.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical display location B29L 31:36

Claims (4)

[Claims] 1. A first foam layer, a reinforcing layer and a second foam layer are laminated in this order, and the reinforcing layer, the first foam layer and the second foam layer. A sealing material characterized by being directly bonded to layers. 2. The sealing material according to claim 1, wherein at least one of the first foam layer and the second foam layer is made of flexible polyurethane foam. 3. One surface of the reinforcing material continuously supplied,
The first foaming raw material is supplied to form the first foaming raw material layer,
Then, the first foaming raw material is reacted and cured to form the first foaming raw material layer as a first foam layer, and at the same time, the one surface of the reinforcing material and the first foam layer are joined together. Then, a two-layer laminate consisting of the reinforcing material and the first foam layer is continuously supplied, and a second foaming raw material is supplied to the other surface of the reinforcing material to form a second foam. A raw material layer is formed, and then the second foaming raw material is reacted and cured to form the second foaming raw material.
The second foam layer is used as the foaming raw material layer, and at the same time, the other surface of the reinforcing material and the second foam layer are joined together to obtain 3
A method for producing a sealing material, comprising obtaining a sealing material having a predetermined shape from a laminated body of layers. 4. A first foaming raw material is supplied to form a first foaming raw material layer on a surface of a release material which is continuously supplied, and then a reinforcing material is continuously supplied to form a first foaming raw material layer. The surface is brought into contact with the first foaming raw material layer, then the second foaming raw material is supplied to the other surface of the reinforcing material to form a second foaming raw material layer, and then the first foaming raw material and The second foaming raw material layer is reacted and cured to form the first foaming raw material layer and the second foaming raw material layer as a first foam layer and a second foam layer, respectively, and at the same time, the reinforcing material. One surface is bonded to the first foam layer, and the other surface of the reinforcing material is bonded to the second foam layer, and a sealing material having a predetermined shape is obtained from the resulting three-layer laminate. And a method for manufacturing a sealing material.