JP2012227977A - Binding and shock absorbing adhesive sheet for wiring harness - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a binding adhesive sheet for a wiring harness, using a cross-linked foamed polyethylene embossed sheet solving a problem of a foamed polyurethane sheet to improve water resistance, excellent in tensile strength and compression strength, excellent in shock absorbing action against drop impact, and having resistance against an increase in atmospheric temperature.SOLUTION: A binding and shock absorbing adhesive sheet for a wiring harness, for binding a plurality of electric wire groups by being wound around the outer circumference thereof, includes a cross-linked foamed polyethylene as a sheet base material, and subjected to embossing.

Description

  The present invention relates to a wire harness, in particular, a wire harness for automobiles, and an adhesive sheet for buffering.

  For wire harnesses routed along the body of an automobile, polyurethane foam resin is known as a material mainly used conventionally. Since this is an open cell, there is no water resistance, and there is a problem that the frictional noise and the buffering noise between the wire harness and other members are large. Japanese Patent Application Laid-Open No. 2006-127022 provides a first resin layer with a non-foamed resin layer such as polyethylene and polyurethane, and a second resin layer with foamed urethane (referred to as soft urethane tape). As a typical structure, there is one in which electric wires are directly integrated with tape, but the cost is high due to the two-layer structure. Japanese Patent Application Laid-Open No. 2006-120415 describes an embossed tape made of polyethylene, nylon, or the like, but no consideration is given to an ambient temperature or a temperature increase due to overcurrent. JP 2002-78168 A tape body is provided with an adhesive surface and a number of irregularities are provided on the opposite surface. The material used is polyvinyl chloride or polyethylene, and the former vinyl chloride is good because it generates chlorine during combustion. The latter polyethylene is not preferable for maintaining the environment, and the latter polyethylene cannot exhibit its inherent performance when softened at ambient temperature or when an overcurrent flows through the wire. In the invention described in Japanese Patent No. 3087623, a large number of protrusions are provided on one side of the base material with gaps therebetween, but the description that the gaps have a heat dissipation and heat insulation effect and a buffering noise reduction function is described. Although there is a description that assumes that the material resin is vinyl chloride or urethane resin, there is no description of polyethylene.

JP 2006-127022 A JP 2006-120415 A Japanese Patent Laid-Open No. 2002-78168 Japanese Patent No. 3087623

  There are various types of prior art, but the most commonly used polyurethane foam has open cells and good shock absorption, but because it is continuous porous, it absorbs water such as condensed water. There are also demands for ease of use, large thickness, low tensile strength, and suppression of buffer noise due to friction.

  Further, a tape excellent in water resistance such as polyethylene has excellent mechanical strength such as tensile strength, but has a poor buffering effect. In addition, foamed non-crosslinked polyethylene is a closed cell, which is excellent in tensile strength, shock absorbing properties, and the effect of suppressing shock noise during friction, but because the atmosphere and environment are the engine. However, in the unlikely event that it is abnormally hot or the temperature rises due to overcurrent of the wire, it softens and damages its inherent properties.

  As a result of diligent studies to achieve the above object, the present inventor has improved a tape material having good workability for mounting on an electric wire. A wire harness bundling and cushioning adhesive sheet that improves the low heat resistance of conventional foamed polyethylene tape by cross-linking, not only the tape that has been made, but also has excellent tensile and compressive strength and less frictional noise. It is to provide.

  More specifically, the present invention is used for cushioning by winding around the outer periphery of a single electric wire or a plurality of electric wire groups or attaching them to an interior material surface or an outer plate surface where they hit each other. Wire harness bundling and cushioning sheet, comprising a cross-linked foamed polyethylene as a tape base material, and embossing is provided.

  Furthermore, the surface of the embossed concavo-convex pattern surface is the outer surface, and the back surface is the back surface. An adhesive layer is provided on the back surface of the sheet so that it can be fixed in close contact with the wire bundle. There is no gap between the two (claim 2).

  In addition to foaming the material, the embossing has a wire protection function as a cushioning material that relaxes contact with the wire by protruding parts coming into contact with burrs and edges. In addition, by being formed with an ellipse or rectangular fine bonding pattern, the preferable function is exhibited by fine irregularities while maintaining the performance as an adhesive sheet.

  That is, it provides a sound-proofing property while maintaining a preferable tensile strength and the like with a buffering property of a closed-cell foam and a buffering property of embossing, and provides an excellent cableability.

  In the present invention, the sheet includes a tape and a sheet whose shape such as width and length is difficult to say.

  In the production of the crosslinked foamed polyethylene sheet, the polyethylene sheet is usually heated to the decomposition temperature of the foaming agent and foamed to produce a fine closed cell foamed polyethylene sheet.

  In this case, when chemical crosslinking is performed, a peroxide or a silane crosslinking agent may be blended. However, in the case of electron beam irradiation, crosslinking can be performed without blending a peroxide or the like. The sheet may be produced by an extrusion method or a batch method.

  According to the present invention, since the sheet base material has water resistance, it is not affected at all by water such as condensation. In addition, it has excellent tensile strength and compressive strength, and when used for a wire harness, the cushioning sound is extremely low and the cost is low.For example, a wide sheet is prepared, and the sheet has several widths considering the frequency of use. By cutting and preparing, the material can be managed without waste.

  Since vinyl chloride and polyurethane foam generate harmful gas when burned, the appearance of other materials is awaited from the viewpoint of waste disposal as well as fire caused by automobile accidents.

  Note that it is not preferable to use EPDM instead of polyethylene because the material becomes expensive.

The surface view which shows an example of the wire harness binding and buffering adhesive sheet of this invention.

The partial surface view of the wire harness binding and buffering adhesive sheet of this invention.

Sectional drawing which shows an example of the wire harness binding and buffering adhesive sheet of this invention.

The explanatory diagram of the evaluation method of the drop impact sound and the friction sound in the case of the wire harness bundling and cushioning adhesive sheet of the present invention, that is, the crosslinked foamed polyethylene embossed sheet (crosslinked PE2t) and the foamed polyurethane (urethane 4t), and the corrugated pipe. Has been.

Wire harness bundling, shock-absorbing tape of the present invention, ie, a crossed foamed polyethylene embossed sheet (crosslinked PE2t) and foamed polyurethane (urethane 4t), and a corrugated pipe, a graph of drop impact sound and frictional sound, the horizontal axis is frequency Hz The scale strength dB is shown on the vertical axis.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a surface view of the cross-linked foamed polyethylene 11 embossed.

  FIG. 2 is a partially enlarged view of FIG. 1 and shows an embossed state so as to constitute the concave portion 12 and the convex portion 13. Are embossed so as to be continuous in the width direction and alternately in the vertical direction (length direction) to form a constant pattern.

  For example, in FIG. 2, the distance between the centers of adjacent ellipsoidal recesses is 2.3 mm, the minor axis of the ellipse is 0.3 mm, and the diameter of the circular recess at the center of the projection is 1.2 mm. The depth of the recesses can be any embossed pattern of 0.6 mm to 0.7 mm, but the embossed pattern is not limited to this.

  FIG. 3 is an example of a cross-sectional view of the wire harness bundling and cushioning adhesive sheet of the present invention, which is composed of a crosslinked foamed polyethylene sheet having recesses 12 and protrusions 13 formed thereon. A release sheet 15 is shown.

  The above-mentioned cross-linking foaming and embossing have an effect of absorbing an impact.

  The pressure-sensitive adhesive sheet of the present invention is used by being wound with the embossed surface on the surface side and the pressure-sensitive adhesive application surface on the inner surface.

  As the cross-linked foamed polyethylene sheet used in the present invention, for example, trade name Softlon manufactured by Sekisui Chemical Co., Ltd. is used. Moreover, for example, a two-component curable acrylic pressure-sensitive adhesive manufactured by Toyo Ink Manufacturing Co., Ltd. is used as the pressure-sensitive adhesive.

  In practicing the present invention, if a wide sheet material is cut into 25 mm width, 40 mm width, 75 mm width, and 150 mm width to make 20 m roll and 30 m roll, it is practically advantageous to use.

  When the wire harness bundling and cushioning adhesive sheet according to the present invention is used for a wire harness, the release sheet 15 may be peeled off and wound with the adhesive layer on the article side. Moreover, it can also affix on the interior material and outer-plate surface of the part which one electric wire or harness hits.

  Softlon S # 3002 manufactured by Sekisui Chemical Co., Ltd. is preferably used for the polyethylene substrate used here.

  And the air bubbles of the crosslinked foamed polyethylene sheet have an aspect ratio (average cell diameter of MD / average cell diameter of CD) of 0.25 to 1, and the flexibility and preferable tensile strength of the foam sheet are maintained. .

The degree of cross-linking is obtained by taking a test piece of about 100 mg from a sheet, weighting the test piece in Amg, immersing the test piece in 120 ° C. xylene, filtering for 24 hours and then filtering with a 200-mesh wire mesh, and vacuum-drying the insoluble part. When the obtained weight is Bmg, the degree of crosslinking is calculated as 100 × (B / A).
The degree of crosslinking is preferably about 10 to 40% by weight.

  As the pressure-sensitive adhesive, a pressure-sensitive adhesive having a main chain of a copolymer of butyl acrylate, ethyl acrylate, 2-ethylhexyl acrylate, and methyl methacrylate and an acrylic functional group component is used. As a representative example in the present invention, a two-component curable acrylic pressure-sensitive adhesive manufactured by Toyo Ink Co., Ltd. is preferably used.

  As the release sheet, a paper coated with a known silicon resin or fluororesin is used.

  Further, when the crosslinked foamed polyethylene sheet according to the present invention is compared with the uncrosslinked foamed polyethylene sheet, the former is preferable in an environment where the temperature of the engine rises because the use temperature rises to about 10 ° C.

  When the wire harness bundling and cushioning adhesive sheet material of the present invention is used, a plurality of electric wire groups can be bundled on the adhesive surface, and the burr of the vehicle and the edge of the embossing due to the fine foaming and embossing unevenness of the sheet itself Protects the wires from interference and prevents wear. In addition, the buffering function of the embossed space formed on the surface side of the sheet can reduce buffering noise caused by contact with other members.

  In addition, because the sheet is closed-celled, heat resistance is improved by cross-linking the base material without being affected by dew condensation. Can prevent the effects of.

  In order to confirm the effects of the present invention, comparative tests were conducted on the following examples and comparative examples.

  Table 1 shows the results of measuring the tensile strength, elongation, compressive strength, and bending rigidity of the cross-linked foamed polyethylene used in the present invention, the embossed tape of the present invention, and the urethane foam tape.

  However, the tensile strength and elongation were measured according to JISK-6767, and the adhesive strength was measured according to JIS-Z-0237. It can be seen that the product of the present invention is superior in tensile strength and compressive strength to the polyurethane foam H tape.

  Table 2 shows a characteristic comparison between the crosslinked foamed polyethylene and the non-crosslinked foamed polyethylene. According to this, it can be seen that the one having a cross-linked structure in terms of elongation and tear strength, maximum use temperature and appearance is superior.

  Further, when the crosslinked foamed polyethylene sheet according to the present invention is compared with the non-crosslinked foamed polyethylene sheet, the former can withstand a high temperature of about 10 ° C., which is preferable in an environment where the engine temperature rises. It can be understood from Table 2 that the tensile strength, elongation, and tear strength are preferably cross-linked, excellent in maximum use temperature, and good in appearance.

  Although the silencing evaluation of the product of the present invention and the comparative example was performed, as shown in the graphs measured for the SUS plate, PP plate, and SS plate of FIG. 4 below, the foamed polyurethane according to the present invention (described as foamed PE2t) It is understood that it is extremely superior.

  In order to measure the silencing effect, the rubbing sound was measured according to the following criteria.

  Drop impact sound and friction sound were evaluated.

  The samples are the following three types.

  1) A φ15 wire bundle (a bundle of 14 wires) placed in a corrugated tube.

2) In addition to 1) above, a single foamed urethane sheet (4t).
3) In addition to 1) above, a single layer of a crosslinked PE sheet (2t).
Test device Test piece: SUS, PP resin, PE resin 2 mm thickness According to the test method of FIG. 4 In FIG. 4, the urethane tape described in the test piece is a foamed polyurethane sheet, and the foamed PE emboss is foamed crosslinked polyethylene. Refers to an embossed sheet.

  The evaluation method of the drop impact sound in FIG. 4, that is, the test piece described in 1 was used for the evaluation by the drop impact sound evaluation method 2 in FIG. 4 and the friction sound evaluation method 3 in FIG.

The result is as shown in FIG. 5, and it can be seen that the foamed crosslinked polyethylene embossed sheet according to the present invention is excellent.
Incidentally, the test sample represents no cushioning material (corrugated) · urethane foam sheet (foam) 4t (sushi roll) and foamed PE emboss (both 200 mm long, t is thickness mm).

  Sound meter: Lion NA-27 type was used.

  The test plate was placed on a horizontal table, and a sound measuring device was installed so that sound measurement was possible at a position 10 mm away from the contact portion between the test tape and the test plate.

  In addition, the test method of the frictional sound measured the sound generated by manually pulling the test piece once about 30 mm and rubbing the test tape and the test plate at that time.

  The measurement results were graphed with the sound pressure (dB) on the vertical axis and the frequency (Hz) on the horizontal axis for each test sample and test plate.

  According to this, for each of the SUS plate, PP plate, and PE plate, the product of the present invention has a buffering performance equivalent to that of 4 mm of urethane foam with a thickness of 2 mm, and the rubbing sound is 20 to 30 dB lower than the others. was gotten.

  The result is as shown in FIG.

  The present invention can be widely used in the automobile industry and the aircraft industry.

11 Crosslinked foamed polyethylene 12 Concave part 13 Convex part 14 Adhesive layer 15 Release sheet In addition, foamed polyurethane generates harmful gas when it burns, so of course from the point of waste disposal as well as fire due to automobile accidents, The advent of other materials has been awaited, but the present invention solves this.

  Moreover, the used wire harness cannot be protected sufficiently from protection against impact and friction.

  In addition, it is not preferable to use EPDM instead of polyethylene because it increases costs.

  The wire harness bundling and cushioning sheet of the present invention shown above can be prepared as a tape winding cut for ease of use, if necessary.

  A preferable sheet has a cross-linking degree of 5 to 160% by weight, and a bubble aspect ratio (average bubble diameter of MD / average bubble diameter of CD) of 0.25 to 1.

  The cross-linked foamed polyethylene sheet of the present invention has a greater effect of reducing the rubbing sound than the urethane foam, as compared to a non-foamed polyethylene sheet. However, when using a foamed polyethylene sheet with a uniform fine concavo-convex pattern, it is easy to cut using the pattern, and it is easy to adapt to various sizes and shapes, so it is inexpensive and has a protective effect. Is obtained. In addition, as an effect of the pattern, it is difficult to generate wrinkles even when the foamed polyethylene sheet is bent, and thus there is an advantage that a preferable protective structure can be obtained.

  The crosslinked foamed polyethylene sheet for a wire harness of the present invention is used by being wound around a wire harness in the same manner as this conventional tape.

  In use, it can be wrapped directly around the wire or around the connector. When a corrugated tube is used, it can be wound around the periphery.

  Moreover, since the cross-linked foamed polyethylene sheet of the present invention uniformly provided with a fine concavo-convex pattern forms a fine pattern with concave portions and convex portions as shown in FIG. 1, it is the same in any part of the sheet. The thickness becomes constant as the pattern becomes finer. Moreover, since it is a sheet | seat, it can respond to any request | requirement of single winding and multiple winding.

  Further, the crosslinked foamed polyethylene sheet of the present invention is superior in tensile strength and compressive strength to those of conventionally used foamed polyurethane sheets as shown in Table 1, and is crosslinked with the crosslinked foamed polyethylene sheet of the present invention. As shown in Table 1, when the foamed polyethylene sheet and the corrugated sheet are compared, the tear strength becomes stronger and the maximum operating temperature is increased by about 10 ° C., so that it can withstand the increase in ambient temperature and the appearance of the embossed sheet is considered. The non-crosslinked product has large bubbles and rough irregularities, whereas the non-crosslinked product according to the present invention has a small surface and a smooth surface, and voids are generated in the portion to be wound, the lap winding portion, etc. It is possible to achieve effects such as less fear.

  Moreover, the crosslinked foamed polyethylene sheet used in the present invention has a feature that it is difficult to deteriorate.

More specifically, the present invention is used for cushioning by winding around the outer periphery of a single electric wire or a plurality of electric wire groups or attaching them to an interior material surface or an outer plate surface where they hit each other. Wire harness bundling and cushioning sheet, which is a wire harness bundling and buffering pressure-sensitive adhesive sheet characterized in that a cross-linked foamed polyethylene is used as a sheet base material and embossing is provided (Claim 1).

11 cross-linked polyethylene foam 12 recess 13 protrusion 14 adhesive layer 15 a release sheet

In addition, since polyurethane foam generates harmful gas when it burns, the appearance of other materials has been awaited from the viewpoint of waste disposal as well as fire due to automobile accidents. This is a solution.
Moreover, the used wire harness cannot be protected sufficiently from protection against impact and friction.

For wire harnesses routed along the body of an automobile, polyurethane foam resin is known as a material mainly used conventionally. Since this is an open cell, there is no water resistance, and there is a problem that the frictional noise and the buffering noise between the wire harness and other members are large. JP 200 8 -127 022 discloses a polyethylene in the first resin layer, a resin layer not expanded, such as polyurethane is provided, and provided with a urethane foam (it is said that soft urethane tape) to the second resin layer, the A typical structure is one in which electric wires are directly integrated with a tape, but the cost is high due to the two-layer structure. JP 200 8 -120 415 issue Publication polyethylene, those embossed tape such as nylon is described, and the ambient temperature, no consideration is made with respect to the temperature increase due to overcurrent. JP 2002-78168 A tape body is provided with an adhesive surface and a number of irregularities are provided on the opposite surface. The material used is polyvinyl chloride or polyethylene, and the former vinyl chloride is good because it generates chlorine during combustion. The latter polyethylene is not preferable for maintaining the environment, and the latter polyethylene cannot exhibit its inherent performance when softened at ambient temperature or when an overcurrent flows through the wire. In the invention described in Japanese Patent No. 3087623, a large number of protrusions are provided on one side of the base material with gaps therebetween, but the description that the gaps have a heat dissipation and heat insulation effect and a buffering noise reduction function is described. Although there is a description that assumes that the material resin is vinyl chloride or urethane resin, there is no description of polyethylene.

JP 2008-127022 A JP 2008-120415 A Japanese Patent Laid-Open No. 2002-78168 Japanese Patent No. 3087623

In addition to foaming the material, the embossing has a wire protection function as a cushioning material that relaxes the contact with the wire by contacting the burrs and edges, but the embossed shape is circular , long By being formed with a fine bonding pattern of circles, the preferable function is exhibited by the fine unevenness while maintaining the performance as an adhesive sheet (Claim 3).

Claims (3)

  Wire harness bundling and buffering adhesive sheet wound around the outer periphery of a plurality of electric wire groups, characterized by having a cross-linked foamed polyethylene as a base material and provided with embossing Adhesive sheet.   Wound around the outer periphery of a single electric wire or a group of multiple electric wires or attached to the interior material surface and outer plate surface where they hit, and bound together with wire harness bundling, buffer adhesive sheet used for buffering The wire harness binding and buffer according to claim 1, wherein an adhesive layer is provided on the back surface of the sheet having an embossed concavo-convex pattern processed surface on the outer surface and the back surface on the back surface. Adhesive sheet.   The wire harness binding and cushioning adhesive sheet according to claim 1 or 2, wherein the embossing is formed with a diamond, circle, oval, or rectangular coupling pattern.

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