JP2008265071A - Method for jointing sheet material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for jointing sheet materials which keep a jointing position hard to shift, jointing strength high, and heat resistance of jointing part good. <P>SOLUTION: In the method for jointing the sheet materials in which end parts of two sheets of the sheet materials 11 and 21 consisting of a foamed body 11A and a coating material 11B and having flexibility are piled and joined, after the end parts 12 and 22 of two sheets of the sheet materials 11 and 21 are piled up through a tacky adhesive 31 with tacky adhesiveness, by compressing, heating and jointing the end parts 12 and 22 of the sheet materials, positional shift of the sheet materials 11 and 21 is prevented with the tacky adhesiveness of the tacky adhesive 31 during heating and compressing the end parts 12 and 22 of the sheet materials so as to be able to correctly compressing and heating the end parts 12 and 22, and to make jointing of the end parts 12 and 22 good. The tacky adhesive 31 has a higher heat resistance than the heat resistance of the sheet materials 11 and 21 to make the heat resistance of the sheet materials after jointing good. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method for overlapping and joining the end portions of two sheet materials.

  Conventionally, as a method of overlapping and joining the end portions of two sheet materials, a method of superposing and thermoforming them with a hot melt nonwoven fabric, or an end portion of two sheet materials made of polyurethane foam, an adhesive There is a method in which heating and pressurization are performed without interposing them. Especially, since the sheet material with a thinner product thickness is desired to be supplied in a longer length, a product form capable of continuous supply via bonding is desired. In particular, in a sheet material for a long tape for covering a bundle of a plurality of core wires such as optical fiber cables, it is preferable to use urethane foam as a constituent material of the sheet material because flexibility is required. Yes.

  However, since the bonding method using hot melt nonwoven fabric does not have adhesiveness at room temperature, there is a problem that the position is easily shifted when the end portions of the sheet material are stacked through the hot melt nonwoven fabric, and it is difficult to bond correctly. is there. Furthermore, in the joining method using a hot melt nonwoven fabric, it is necessary to heat the end of the sheet material to a temperature equal to or higher than the melting point of the hot melt agent. A hot melt agent having a melting point lower than the heat resistance temperature must be selected. Therefore, the edge part of the joined sheet | seat material will be joined by the adhesive agent with low heat resistance, and depending on a use, the heat resistance of a junction part may be insufficient and there exists a possibility of peeling.

  On the other hand, it is difficult to say that the bonding strength is sufficient in the bonding method in which the end portions of the sheet material made of two urethane foams are stacked and heated and pressed without using an adhesive, and depending on the application, the bonding strength is insufficient. And may peel off.

JP 2001-328172 A JP 2001-171006 A

  The present invention has been made in view of the above-described points, and an object of the present invention is to provide a sheet material bonding method in which the bonding position is difficult to shift, the bonding strength is high, and the heat resistance at the bonded portion can be improved.

  The invention according to claim 1 is a method for joining sheet materials in which end portions of two flexible sheet materials are overlapped and joined to each other, and an end portion of the two sheet materials via an adhesive having adhesive properties. After stacking, the end is compressed and heated.

  The invention of claim 2 is characterized in that, in claim 1, the pressure-sensitive adhesive has a heat resistance higher than the heat resistance of the sheet material.

  In the invention of claim 1, since the compression and heating are performed after the end portions of the two sheet materials are overlapped via the adhesive having adhesiveness, the end portions of the two sheet materials are displaced after being overlapped. It is difficult and can be joined accurately.

  In the invention of claim 2, since the adhesive provided between the end portions of the sheet material has higher heat resistance than the sheet material, the joint portion of the sheet material can have high heat resistance.

  Hereinafter, embodiments of the present invention will be described in detail. In the present invention, after the end portions of two sheet materials are stacked via an adhesive having adhesiveness, the end portions of the sheet materials are compressed and heated to join the sheet materials. In the example, the method includes a step of providing an adhesive on the end of the sheet material, a step of overlapping the end of the sheet material via the adhesive, and a step of compressing and heating the end of the sheet material.

  Hereinafter, the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view of a state in which an adhesive is provided on one sheet material in one embodiment of the present invention, and FIG. 2 is a cross-sectional view of the state in which the end portions of the sheet material are overlapped with the adhesive in the same embodiment. 3 is a cross-sectional view of the end portion of the sheet material in a compressed and heated state in the same embodiment, and FIG. 4 is a schematic cross-sectional view showing a state after joining in the same embodiment.

  The two sheet materials 11 and 21 used are made of a flexible material. Each sheet material 11 and 21 may be a single layer or multiple layers as long as it has flexibility. For example, a single-layer product such as a foam or a non-woven fabric, or a multi-layer product composed of foams 11A and 21A and covering materials 11B and 21B, such as sheet materials 11 and 21 shown in FIG. But you can. Examples of the foam of the sheet material 11 made of a single-layer product or a multilayer product include suitable foams such as polyurethane foam, polyolefin foam, rubber foam, and silicone foam. In addition, examples of the covering materials 11B and 21B in the sheet material made of a multilayer product include a nonwoven fabric and a tricot. One of the two sheet materials 11 and 21 to be joined may be a single layer made of only a foam or the like, and the other may be a multilayer of a foam layer and a covering layer.

  It is preferable that the pressure-sensitive adhesive 31 is composed only of a pressure-sensitive adhesive having no base material because it is difficult to impair flexibility at the joining end portion of the sheet material. When the pressure-sensitive adhesive 31 is a double-sided adhesive tape having layers of pressure-sensitive adhesive on both sides of the base material, the base material of the pressure-sensitive adhesive is interposed between the joint ends of the sheet material, and the joint end of the sheet material is flexible. It comes to lose. The pressure-sensitive adhesive 31 is preferably one having adhesiveness at room temperature, such as an acrylic pressure-sensitive adhesive. By having adhesiveness at room temperature, after being provided at the end 12 of at least one sheet material 11, the pressure-sensitive adhesive 31 and the sheet material are not compressed until the sheet material ends 12 and 22 are compressed and heated, or during compression and heating. The end portions 12 and 22 of the sheet material can be correctly joined without causing positional deviation at the end portions. Further, the pressure-sensitive adhesive 31 preferably has higher heat resistance than the heat resistance of the sheet materials 11 and 21. By doing in this way, the joining edge part of a sheet | seat material can be made hard to peel in the use temperature range of a sheet | seat material. The heat resistance varies depending on whether the material is thermoplastic or thermosetting, but is defined by the melting point, softening temperature, decomposition temperature, alteration temperature, moldable temperature, etc. of the material. The property is defined by a decomposition temperature and an alteration temperature at which tackiness cannot be maintained. On the other hand, when the sheet material is a thermoplastic resin (polyethylene, polypropylene, polyester, etc.), the heat resistance of the sheet material 11, 21 generally refers to the melting point of the thermosetting resin (polyurethane, acrylic, etc.). In this case, it means the lowest temperature among decomposition temperature, alteration temperature and moldable temperature. Examples of the pressure-sensitive adhesive 31 include an acrylic type and a rubber type.

  In the step of providing the pressure-sensitive adhesive at the end portion of the sheet material, the pressure-sensitive adhesive 31 is provided at the end portion 12 of at least one sheet material 11 of the two sheet materials 11 and 21 as shown in FIG. The thickness of the pressure-sensitive adhesive 31 is appropriately determined, but is preferably about 0.03 to 0.5 mm in order to reduce the level difference after bonding and to prevent a decrease in flexibility. As the pressure-sensitive adhesive 31, it is easy to use a tape-like one in which the surface of the pressure-sensitive adhesive 31 is covered with a release paper, by peeling the release paper. Although the width | variety of the said adhesive 31 is determined suitably, an example is about 5.0-15.0 mm.

  In the step of stacking the end portions of the sheet material via the adhesive, as shown in FIG. 2, the end portions 12 of the sheet materials 11, 21 are provided via the adhesive 31 provided on the end portion 12 of at least one of the sheet materials 11. , 22 are stacked.

  In the step of compressing and heating the end portions of the sheet material, as shown in FIG. 3, the end portions 12 and 22 of the sheet materials 11 and 22 stacked via the adhesive 31 are compressed by a compression heating device 41 and heated. To do. At the time of the compression, since the positions of the end portions of the sheet materials 11 and 21 are difficult to shift due to the adhesiveness of the adhesive 31, the end portions of the sheet materials 11 and 21 can be correctly compressed and heated to be joined. The degree of compression of the end portions of the sheet materials 11 and 21 is set as appropriate. As an example, a case where the compression is 10% to 90% with respect to the original thickness of one sheet material is given. The heating temperature is appropriately adjusted depending on the material of the sheet materials 11 and 21, but is preferably set to −10 ° C. to + 30 ° C. with respect to the heat resistance temperature of the flexible sheet materials 11 and 21. If the heating temperature is too low, bonding strength can be obtained to some extent by compression. However, since the recovery of the flexible sheet materials 11 and 21 becomes remarkable, the bonding portion becomes a convex step, and a long product is rolled. When the product is used, defects such as winding and peeling are likely to occur. On the other hand, if the heating temperature is too high, the sheet materials 11 and 21 are deteriorated, and sufficient bonding strength cannot be obtained or discolored. The compression heating device 41 includes a clamping unit that can clamp the sheet material end, and a known device that can be heated to a desired temperature by a heater or the like can be used. When the compression and heating are performed on the end portions 12 and 22 of the sheet materials 11 and 21, and then the compression and heating are released, a bonded sheet material is obtained as shown in FIG.

The sheet materials were joined by the method of the present invention using the sheet materials A to C and the adhesives A and B shown in Table 1 (Examples 1 to 5). The sheet material A is a polyurethane foam (manufactured by Inoac Corporation, product number: SL-86N, heat resistance: about 200 ° C.) and a polyester nonwoven fabric (manufactured by Asahi Kasei Co., Ltd., product number: E05030, heat resistance: about 220 ° C., Two-layer product with a basis weight of 30 g / m ² ), sheet material B is a single-layer product, sheet material of polyurethane foam (manufactured by INOAC CORPORATION, product number: SL-86N, heat resistance: about 200 ° C.) C is a single-layer product of a polyethylene foam (manufactured by Inoac Corporation, product number: B-200, heat resistance: about 120 ° C.). The width of the sheet material is 70 mm. In addition, the thickness (mm) of the sheet | seat material column in each Example shows the thickness of a foam. Adhesive A is an acrylic adhesive (manufactured by Nitto Denko Corporation, product number: No. 5919, heat resistance: about 240 ° C.), and adhesive B is an acrylic adhesive (manufactured by Nitto Denko Corporation, product number: No. 5). 591, heat resistance: about 240 ° C.). The width of the adhesive is 5 mm. For compression heating, it is possible to adjust the temperature of the upper and lower compression discs, and those that can be released in a specified time can be used. For example, Shiga Packing Machine Co., Ltd. product number: Soft Sealer 200ENW can be used. The compression heating conditions were a compression width of 8 mm, a heating compression time: 45 seconds, and the degree of compression was 20% with respect to the original thickness of one sheet material.

  In Table 1, Examples 1 and 2 are examples of different sheet materials, Examples 2 and 3 are examples of different thicknesses of sheets, Examples 2 and 4 are examples of different adhesives, Examples 2 and 5 are examples in which the sheet material of the single-layer product is made different and the heating temperature is also made different.

  For comparison, the sheet materials were joined as shown in Table 2 (Comparative Examples 1 to 7). In Table 2, the hot melt adhesive A is a polyamide system (manufactured by Kureha Tech Co., Ltd., product number: LNS2020, melting point: 115 ° C.), and the hot melt adhesive B is a polyester system (manufactured by Kureha Tech Co., Ltd., product number: G5025, melting point). : 150 ° C.).

  In Table 2, Comparative Examples 1 and 2 are examples in which hot melt adhesives A and B are used instead of the adhesive A in Example 1, and Comparative Example 3 is a sheet material without using the adhesive A in Example 1. In Comparative Example 4, the end portions of the sheet material were stacked and heat sealed at 190 ° C. without using the adhesive B in Example 3. In Comparative Example 5, the end of the sheet material is compressed only in Example 1 without heating. In Comparative Examples 6 and 7, a hot melt adhesive A was used in place of the pressure-sensitive adhesive in Example 5, and the heating temperature was varied.

  The bonding strength at normal temperature (normal temperature), 150 ° C. (5 minutes standing), and 100 ° C. (5 minutes standing) was measured for each example and each comparative example, and the heat resistance, appearance and finish were judged. The results are as shown at the bottom of Tables 1 and 2.

  The bond strength was measured by using a strip-shaped test piece having a thickness of 25 × 150 mm after bonding, a distance between chucks of 100 mm, and a tensile speed of 100 mm / min. Was defined as the bonding strength. As for heat resistance, even in the measurement of bonding strength under various temperature atmospheres, material destruction at the foam part was obtained, and as a result of judging the presence or absence of discoloration and alteration by visual observation, those with good condition without discoloration and alteration It was. On the other hand, in the bonding strength measurement at the time of heating, the case where interfacial peeling was confirmed at the joint, or the case where discoloration or alteration was confirmed by visual judgment was marked with x. Appearance finish is judged by visual inspection, where the step of the joint is thinner than the thickness of the sheet material and a uniform joint is confirmed ○, when the joint is larger than the thickness of the sheet material, or discoloration, alteration, or shrinkage X was confirmed as x. In addition, when a remarkable hollow appeared, it was set as (concave).

  As can be understood from Tables 1 and 2, Examples 1 to 5 had high bonding strength when heated (150 ° C., 100 ° C.), good heat resistance, and good appearance of the joint. . On the other hand, Comparative Example 1 using hot melt adhesive A (melting point 115 ° C.) has a low bonding strength in the heated state, while Comparative Example 2 using hot melt adhesive B (melting point 150 ° C.) is endless. At the time of compression / heating of the part, the sheet material was denatured at the joint part and contraction occurred. Since Comparative Example 3 and 4 are joining by the conventional heat seal, a remarkable recessed part generate | occur | produces in a joined part, and since it becomes line joining, in Comparative Example 3, compared with Example 1, joining strength becomes low, In Comparative Example 4 in which the thickness of the foam was increased, it was confirmed that partial peeling occurred at the joint due to restoration of the foam after joining, and the sheet product was not established. In addition, since heat sealing is joining by thermal adhesion without using an adhesive medium, the joining strength is not obtained for a sheet material having no heat fusion property or low, and the sheet materials that can be joined are limited. Since the comparative example 5 was joined only by the compression which does not heat using an adhesive, joining strength was low. In Comparative Examples 6 and 7, hot-melt adhesive A (melting point: 115 ° C.) was used, and the heating temperature was lower than those in Comparative Examples 1 and 2. In this case, the adhesive strength was insufficient and peeling occurred at room temperature. (Comparative Example 6) or could not be joined (Comparative Example 7).

It is sectional drawing of the state which provided the adhesive in one sheet material in one Example of this invention. It is sectional drawing of the state which accumulated the sheet | seat material edge part through the adhesive in the Example. It is sectional drawing of the compression and heating state of a sheet | seat material edge part in the Example. It is a schematic sectional drawing which shows the state after joining in the Example. It is an expanded sectional view of the state which provided the adhesive to the sheet material of other examples.

Explanation of symbols

11, 21 Sheet material 12, 22 Edge of sheet material

Claims (2)

In the joining method of the sheet material that overlaps and joins the end portions of the two sheet materials having flexibility,
A method for joining sheet materials, comprising: stacking end portions of the two sheet materials through an adhesive having adhesiveness, and then compressing and heating the end portions.   The method for joining sheet materials according to claim 1, wherein the pressure-sensitive adhesive has heat resistance higher than that of the sheet material.

Images