JP2009158694A - Noise suppressing sheet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve problems resulting from the combination of a noise suppressing sheet and other members (a surface protective PET film and an adhesive). <P>SOLUTION: A surface protective layer 2 is provided to at least a part of one surface of the noise suppressing sheet made of the mixed body 1 of flat type soft magnetic powder and a resin, and an adhesive layer 3 is provided to at least a part of the other surface. Surface protective films 2 are provided to at least a part of both the surfaces of the noise suppressing sheet, and an adhesive layer 3 is provided to the surface protective film on the one surface of the sheet. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a noise suppression sheet suitable for preventing electromagnetic interference caused by interference of unnecessary electromagnetic noise generated in an electronic device.

  A noise suppression sheet made of a mixture of a flat soft magnetic powder and a resin is used as a noise countermeasure for electronic devices including thin and light electronic devices in recent years, and is expanding on the market. In particular, recently, in order to respond to more detailed market requirements, there are many cases where supply is required with a configuration in which a transparent or colored PET film is bonded to protect the surface of the noise suppression sheet. In addition, there are various reasons for the market demand for bonding, but there are many problems related to bonding of PET materials in production.

  For example, there are problems such as appearance, strength (flexibility / easiness of sticking when held), addition of flame retardancy after enabling appearance. For strength (easiness of deflection / easiness of holding), there is a method that uses a weakly-adhesive PET film and removes only the weakly-adhesive PET film after positioning and application. The problem of becoming expensive is still left. Further, in pasting the noise suppression sheet and the PET film, an extra length for pasting is required for processing, and there is a problem of an increase in member cost. In addition, there are also problems such as being peeled off during processing because of being pasted, wrinkles occurring during sticking, or the possibility of foreign matters due to static electricity or the like being mixed.

  In addition, noise suppression sheets are generally thin with a thickness of about several tens of μm to 1.0 mm. Among them, those with a thickness of about 0.3 mm or less are not only thin and inconvenient to handle in the market, but also air bubbles when pasted. Entanglement is a big problem. Regarding bubble entrainment, as can be seen in Patent Document 1 and Patent Document 2, in the PET film market, some adhesive layers have convex portions. When the adhesive layer is formed on one side of the PET film, the recesses are processed into a lattice pattern on the peeling side (paper, plastic material, etc.), and the adhesive layer is applied to deal with the entrainment of bubbles with the PET film placed on the opposite side. There are also products.

However, the techniques disclosed in Patent Document 1 and Patent Document 2 are based on a PET film as a base material, and are only related to products for protection and labeling, and are peeled off to form a concave portion for forming a convex portion in an adhesive portion. A plastic film or the like as a mold is required, and a method of embossing or printing is also required for forming the recess.
In addition, the formation of the convex portion as an adhesive material (for example, double-sided tape) is uneasy about guaranteeing the convex portion in the roll form, and there is little merit because it is necessary to make the product form a sheet. In addition, Patent Document 1 and Patent Document 2 do not have any magnetic property (cannot be used as a noise suppression sheet), and require an adhesive layer composed of small convex portions.
Moreover, in patent document 1 or patent document 2, the convex part is formed on the adhesion surface, and the adhesive material exists in close contact with a smooth surface such as a PET film on the opposite surface.
Although it is necessary on the surface that is directly below the convex portion, the concave portion is unnecessary because it does not contact anywhere, and it is useless on the surface of the member.

Japanese Utility Model Publication No. 8-30 Japanese Utility Model Publication No.6-20043

  The subject of this invention is solving the problem which arises in the combination of a noise suppression sheet | seat and another member (surface protection PET film and adhesive material).

  The present invention provides a noise suppression sheet comprising a mixture of a flat soft magnetic powder and a resin, wherein one surface of the noise suppression sheet is provided with a surface protective layer on at least a part of the surface, The noise suppression sheet is characterized in that an adhesive layer is provided on at least a part of the surface.

  Further, the present invention provides a noise suppression sheet comprising a mixture of a flat soft magnetic powder and a resin, wherein the noise suppression sheet is provided with a surface protection film at least partially on both surfaces of the noise suppression sheet. It is a suppression sheet.

  Further, the present invention provides a noise suppression sheet comprising a mixture of a flat soft magnetic powder and a resin, and a surface protective film is provided at least partially on both surfaces of the noise suppression sheet, on one surface of the sheet The noise suppression sheet is characterized in that an adhesive layer is provided on the surface protective film.

  Moreover, this invention is a noise suppression sheet | seat characterized by the said adhesive layer being print-molded.

  Moreover, this invention is a noise suppression sheet | seat characterized by the said adhesive layer having a some convex part.

  Moreover, the present invention is the noise suppression sheet, wherein the adhesive layer is printed and formed into a predetermined shape with a predetermined interval in the row direction and / or the column direction.

  Moreover, this invention is a noise suppression sheet | seat characterized by the said surface protective film and / or the said adhesion layer being provided with the flame retardance.

The surface protective film in the present invention is preferably used alone or in combination with a resin having a general protective function, but depending on the use of the noise suppression sheet, it is formed with hardness considering the handling such as hardness and bendability. It is preferred that As the resin, it is particularly preferable to use urethane resin, epoxy resin, polyvinyl chloride or the like. However, the surface protective film is not limited to this. Furthermore, the adhesive layer is preferably formed by printing and forming an adhesive layer made of a resin having adhesive strength such as acrylic, rubber-based, or silicone-based.
Furthermore, the pressure-sensitive adhesive layer convex portion is preferably a square shape of 5 mm or more and 30 mm or less, or a circular shape of 5 φ or more and 30 φ or less, and the interval is printed so as to maintain an interval of 0.5 to 1.5 mm at the shortest point. It may be molded.

  According to the present invention, an extra length is not required when the surface-protecting PET film and the adhesive material are attached, and it is possible to prevent wrinkles at the time of sticking and mixing of foreign matters due to static electricity, and to eliminate anxiety factors related to peeling during processing. . In addition, the integrated adhesive layer is formed with convex portions having a predetermined interval at a necessary location, and air entrainment that may occur at the time of application can be reduced.

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

  FIG. 1 is a diagram showing a first embodiment of the present invention, and is configured such that a mixture 1 of flat soft magnetic powder and resin is sandwiched between a surface protective film 2 and an adhesive layer 3.

  FIG. 2 is a diagram showing a second embodiment of the present invention, in which the surface protective film 2 is configured so as to sandwich a mixture 1 of flat soft magnetic powder and resin.

  FIG. 3 is a diagram showing a third embodiment of the present invention, in which a surface protective film 2 is provided so as to sandwich a mixture 1 of flat soft magnetic powder and resin, and any one of the surface protective films 2 is provided. It becomes the structure provided with the adhesion layer 3 on the surface.

  FIG. 4 is a diagram showing a fourth embodiment of the present invention, in which the adhesive layer 3 is printed in a predetermined shape with a predetermined interval.

  FIG. 5 is a diagram showing a fifth embodiment of the present invention, in which the noise suppression sheet cut out in the final process includes at least one interval 5 between the protrusions of the adhesive layer 3 and the protrusions. is there. FIG. 5 (a) is an adhesive layer pattern diagram in which the adhesive layers are arranged in stripes, and the adhesive layer 3 has five convex portion intervals 5, and FIG. 5 (b) is an adhesive layer in which stripes are arranged in an adhesive. FIG. 5C is a pattern diagram in which the pressure-sensitive adhesive layers are arranged in a lattice pattern and the convex space 5 of the pressure-sensitive adhesive layer 3 is 10 in number.

  Next, the present invention will be described in more detail with reference to specific examples.

  As the noise suppression sheet, a mixture composed of a flat soft magnetic powder made of an Fe—Si—Al alloy having an average aspect ratio of 23 and an average particle diameter of 35 μm and a urethane resin as a binder was used. This mixture was kneaded with a biaxial kneader and then processed into a sheet having a thickness of 1 mm with a hot press molding machine. In order to improve the strength, the surface protective film material is based on urethane resin, which is the same kind of resin as the mixture, for easy coating and integration with the mixture. Used as a mixture. For the formation of the surface protective film, two methods of a doctor blade and a screen printer were used. The coating film was dried in an oven at 85 ° C. to obtain a surface protective film of about 35 μm. An acrylic resin was used for the adhesive layer, and an adhesive layer of about 15 μm was formed with a screen printer. The convex part was molded by using a template having an arrangement according to the final shape. The pressure-sensitive adhesive layer of the convex portion was 10 mm square in length and width, and the interval between the convex portions was 1 mm.

  Table 1 shows the evaluation results. In the evaluation, since it is essential that there is no deterioration in the magnetic permeability characteristics, the magnetic permeability was confirmed before and after the test. As a result, there was no deterioration. The test piece was produced by punching a test piece 30 mm long and 30 mm wide from the sheet with a punching die.

  Evaluation of workability was performed based on whether or not the surface protective material of the cross section was lifted by punching 2 mm in width. The evaluation of sticking property was evaluated by the presence or absence of the occurrence of bubble entrapment by intentionally placing the test piece lightly on the adherend and pressure-bonding it with a roller so that air entrapment was likely to occur.

  From the results of evaluation in Table 1, it was found that the inventive product was superior in both processability and sticking property compared to the comparative product.

  In addition, although the doctor blade and the printing machine were used for the molding of the surface protective film on the noise suppression sheet, it is considered necessary to select the equipment depending on the member to be used. There was no difference.

Sectional drawing which shows the 1st Embodiment of this invention. Sectional drawing which shows the 2nd Embodiment of this invention. Sectional drawing which shows the 3rd Embodiment of this invention. Sectional drawing which shows the 4th Embodiment of this invention. FIG. 5A is a diagram showing a fifth embodiment of the present invention, FIG. 5A is a pattern diagram in which the adhesive layer is striped and has five convex portions, and FIG. 5B is a pattern in which the adhesive layer is striped and convex. FIG. 5 (c) is a pattern diagram including three intervals, and FIG. 5 (c) is a pattern diagram in which the adhesive layer has a lattice shape and includes ten convex intervals.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Mixture of flat soft magnetic powder and resin 2 Surface protective film 3 Adhesive layer 4 Convex adhesive layer 5 Interval between convex adhesive layers

Claims (6)

  In the noise suppression sheet comprising a mixture of a flat soft magnetic powder and a resin, a surface protective layer is provided on at least a part of the surface of one side of the noise suppression sheet, and the surface is disposed on the other surface. The noise suppression sheet | seat characterized by the adhesive layer being provided in at least one part.   A noise suppression sheet comprising a mixture of flat soft magnetic powder and resin, wherein the noise suppression sheet is provided with a surface protective film on at least a part of both surfaces of the noise suppression sheet.   In the noise suppression sheet comprising a mixture of a flat soft magnetic powder and a resin, a surface protection film is provided on at least a part of both surfaces of the noise suppression sheet and adheres to the surface protection film on one surface of the sheet. A noise suppression sheet, wherein a layer is provided.   The noise suppression sheet according to claim 1, wherein the adhesive layer is formed by printing.   The noise suppression sheet according to claim 1, wherein the adhesive layer has a plurality of convex portions.   6. The noise suppression sheet according to claim 1, wherein the adhesive layer is printed and formed in a predetermined shape with a predetermined interval in a row direction and / or a column direction. .

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