JP2008090010A - Sheet for sensing wetting - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sheet for sensing wetting, which immediately reacts to the wetting of electronic equipment or the like, and permits to visually discriminate the degree of wetting easily and exactly, and also maintains the state in continuous manner. <P>SOLUTION: On the surface of a water-absorbing base material sheet 1 made of paper, a colorant layer 2, composed of powder dyeing material particles 2-1, is formed by an adhesive layer 3. The dyeing material particles are fixed on the surface of the water-absorbing base material via the adhesive existing among the dyeing material particles, and the colorant layer is constituted. A separate paper 4 is stuck on the back of the water-absorbing base material sheet via the adhesive layer. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention is affixed to various electronic devices such as mobile phones, which often cause failures due to getting wet with water, in order to determine the cause of failure by sensing the wetness during use. It relates to a sheet for wetness detection that functions effectively.

  Electronic devices such as video cameras and mobile phones, as well as various precision devices, are products that are unavoidable due to moisture permeating into the device due to rain or intense sweating, which can cause malfunctions. Therefore, water resistance measures to a considerable extent are taken. However, if it is accidentally dropped into a water reservoir or dropped in a water-filled wash basin, even the internal electronic circuit is immersed in water, which fundamentally impairs its function as an electrical product, and replaces equipment. Full-scale repairs are required, but in the case of such a case, the responsibility is usually passed on to the general consumer who is the user and is subject to repair for a fee. However, it is not easy to determine whether the failure is caused by inadvertent submergence or during normal use. It was the actual situation that caused this. In order to eliminate such troubles, water-soluble coloring resin in which coloring material consisting of dye or pigment is mixed in water-soluble resin is directly applied to the surface of the base sheet. A water-wetting detection identification label on which a colored layer is formed is pasted inside the product in advance through an adhesive layer such as a pressure-sensitive adhesive. It is an example of a conventional general measure to determine the cause of a failure based on the degree of bleeding or discoloration.

  However, in the conventional identification label, when the colored layer is dissolved by getting wet with water, the water-soluble dye penetrates into the inside of the paper forming the base sheet, resulting in a delay in the decoloration speed. Since the eluted colorant penetrates into the inside of the base material sheet and colors it, there is a problem that it is impossible to clearly determine the color loss, and in order to avoid this problem, cobalt-based or amine-based When using ink mixed with the above dye as a colorant, it can be determined that the cause of submergence is due to the discoloration of the ink, but when it dries it returns to its original state, leaving the problem of being indistinguishable. It had been.

In order to solve such problems, the conventional water-wetting sensing sheet shown in FIG. 2 is water-soluble in a water-soluble binder on the surface of a water-soluble substrate sheet 10 made of water-soluble paper such as fine paper. Oil-soluble coloring obtained by mixing a dye or pigment as the coloring material 40 in the oil-soluble resin binder or the water-soluble coloring layer 30 obtained by mixing the coloring dye or pigment as the coloring material 40 Any one of the layers 30 is formed by the adhesive layer 50, and a separate sheet 70 is temporarily attached to the back surface of the water-soluble substrate sheet 10 via the adhesive layer 50 to form a water wetness detection sheet. The thing is proposed (for example, refer patent document 1).
In the case of this water wetness detection sheet, when attaching to an adherend such as the surface of an electronic component, the separation sheet 70 is peeled off, and then attached by no heating or heating pressing depending on the components of the adhesive layer 50. If the product is wet, dipped, submerged, etc., the outer part of the product comes into direct contact with water, or if water enters the product and gets wet, the sensing sheet will be discolored and dried. It has been reported that since the color loss state is maintained even after, objective judgment on whether or not the product is wetted can be made continuously.

On the other hand, in contrast to the detection of water wetting by the color loss of the water wetting detection sheet as described above, a method for confirming water wetting by discoloration of the sheet has also been proposed. As an example, paper that is difficult to repel water is proposed. In addition, a printing material for water wetness detection is obtained by printing a printing ink for waterless flat plate containing a water-soluble dye, and the printed material is adhered to the inside of a device that dislikes water wetting, so that the water inside the device is not wetted. Means for visual confirmation has also been proposed (see, for example, Patent Document 2). In this type of water-sensitive print, the water-soluble dye contained in the printing ink elutes from the printed part by touching water and oozes out to the non-printed part of the paper, and that part conforms to the color of the dye. By changing the color, water wetness is detected by visual recognition, and an excellent characteristic as a water wetted print is disclosed.
Japanese Patent Laid-Open No. 7-334082 JP-A-10-2893

  However, this type of conventional wetness-detecting sheet including the above-described prior art is such that the colored layer formed by printing or coating on the base sheet is water-soluble or oily. Since it is usually formed by mixing in a soluble solvent in a dispersed state, when water enters the colored layer, the intruded water immediately comes into contact with individual coloring materials mixed in the solvent in a dispersed state. However, it gradually penetrates into the solvent and comes into contact with the colorant, causing it to lose color and lead to loss of color, or the colorant is spread to the unprinted sheet surface. However, until the color was changed, a considerable time lag could not be avoided. In addition, the coloring material dispersed in the solvent may be seen through the surface of the water-soluble base sheet made of high-quality, colorless thin paper. There was also a problem of becoming.

  The present invention has been made to solve such problems of the prior art, reacts immediately to water wetting of electronic devices and the like, and can easily and accurately determine the degree of water wetting by visual recognition, It is an object of the present invention to provide a water wetness detection sheet that maintains its state continuously.

The water wetting detection sheet according to the present invention has a colorant layer made of powdered dye material particles formed on the surface of a paper-made water-absorbing substrate sheet, and further has an adhesive layer on the colorant layer. The separator and the paper are detachably attached to each other, and the coloring material layer is configured such that the coloring material particles are fixed to the surface of the water-absorbing substrate sheet via the adhesive present between the coloring material particles. It is characterized by this.
In addition, the water wetness detection sheet is preferably a paper-absorbing base material sheet that has been treated so that the colorant layer is hardly visible through the surface side. As such a water-absorbing substrate sheet, for example, a sheet in which a thickener is impregnated can be adopted.

The water wetting detection sheet of the present invention configured as described above has almost no colorant layer that can be seen through the surface of the water-absorbent base material sheet. There is no ambiguity in sync. In the case of the water wetness detection sheet of the present invention, the powdery colorant is directly fixed to the water-absorbent substrate sheet surface via an adhesive present between the dye particles constituting the colorant layer. Therefore, when the surface of the water-absorbent substrate sheet is wetted, the moisture that permeates due to the capillary phenomenon of the substrate sheet directly contacts the dye particles forming the colorant layer, and the dye is It can be exuded and discolored on the surface of the base material sheet, and water wetting can be confirmed quickly and accurately by visual observation. Moreover, since the state is maintained with persistence even after drying, it can be used as an effective means for detecting wetness.
In addition, when using the water wetness detection sheet of the present invention, the separation paper that is detachably attached to the back surface of the paper-made water-absorbing substrate sheet is peeled off, and the predetermined inside of the target device is removed. Affix to the position.

  FIG. 1 is a schematic enlarged cross-sectional view for explaining a water wetting detection sheet according to an embodiment of the present invention, wherein 1 is a paper water-absorbing base material sheet, and 2 is a powdery colorant layer. Reference numeral 2-1 denotes dye particles, 3 denotes an adhesive layer, and 4 denotes a separate paper.

  That is, the water-wetting detection sheet according to the present invention has a colorant layer 2 composed of powdery dye particles 2-1 formed on the surface of a paper-made water-absorbing substrate sheet 1 by an adhesive layer 3, A separate paper 4 is detachably attached to the back surface of the water-absorbent substrate sheet 1 via the adhesive layer 3. Here, the coloring material layer is configured such that the coloring material particles 2-1 are directly fixed on the water-absorbent substrate sheet 1 via the adhesive 3 existing between the powdery coloring material particles 2-1. ing.

  In addition, when using the water wetness detection sheet | seat of the said structure, the separate paper 4 stuck on the back surface of the base material sheet 1 via the adhesive bond layer 3 is peeled, and it sticks inside the apparatus.

  Here, as a material for forming the water-absorbent base sheet 1, there is no particular problem as long as it is a commercially available printing / information paper having water absorption, art paper, high-quality / medium-quality coated paper, Water-soluble synthetic resins and papers synthesized from these are used, and high-quality paper having water absorbability is preferably used. Needless to say, as the water-absorbent base sheet 1 made of paper, the colorant layer 2 is hardly visible through the surface side. As such a base material sheet, for example, a paper having various water-absorbing papers that has been treated so that the colorant layer 2 is hardly visible through the surface side is used. As such paper, for example, a paper in which a thickener is impregnated can be used. Moreover, as a color material which forms the color material layer 2, it arbitrarily selects from the color material which consists of various dyes, an organic pigment, an inorganic pigment, and those mixed compositions, and is employ | adopted. The coloring material can be dispersed on the base sheet 1 by means such as spraying.

  The water-wetting detection sheet of the present invention having the above-described configuration is attached to a predetermined position in various electronic devices that do not like water wetting, and when the water-absorbing substrate sheet 1 is wetted, The water that permeates through the capillary action of the sheet comes into direct contact with the dye particles 2-1 that form the colorant layer 2, and the dye is exuded and discolored on the surface of the base sheet 1, so that the water is wet by visual inspection. Can be quickly and easily confirmed. Further, even after the water wetness detection sheet is dried, the state is maintained with persistence, so that it can be utilized as an effective means for determining water wetness.

  The water wetness detection sheet of the present invention is applied to a predetermined position in various electronic devices that do not like water wettability, and when water wettability occurs on the surface of the base material sheet, it is caused by the capillary phenomenon of the water absorbent base material sheet. The infiltrated water is in direct contact with the dye particles forming the colorant layer, and the dye is exuded and discolored on the surface of the base material sheet to quickly and easily confirm the water wetting visually. Therefore, it is extremely practical as a label or sheet for detecting water wetting of electronic devices and the like. Further, in the case of the water wetness detection sheet of the present invention, since the state is maintained with persistence even after the sheet is dried, it can be used as an effective means for determining water wetness. Is possible.

It is a typical expanded sectional view for explaining the sheet for wetness detection by one example concerning the present invention. It is an expanded sectional view showing typically an example of the conventional water wetness detection sheet.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Paper-made water-absorbing base material sheet 2 Coloring material layer 2-1 Dyeing material particle 3 Adhesive layer 4 Separate paper

Claims (3)

On the surface of the water-absorbent base sheet made of paper, a colorant layer composed of powdered dyeing material particles is formed, and a separate paper is further detachably attached to the colorant layer via an adhesive layer. The water color sensing sheet is characterized in that the coloring material layer is constituted by fixing the coloring material particles to the surface of the water-absorbing substrate sheet via the adhesive present between the coloring material particles. 2. The water wetness sensing sheet according to claim 1, wherein the paper-made water-absorbing base sheet is treated so that the colorant layer is hardly seen through the surface side. . The water-absorbing sheet according to claim 1, wherein the water-absorbent base sheet made of paper is impregnated with a thickener.