JP2006272831A

JP2006272831A - Writing plate

Info

Publication number: JP2006272831A
Application number: JP2005097715A
Authority: JP
Inventors: Tatsuya Mizoguchi; 達也溝口
Original assignee: Mitsubishi Pencil Co Ltd
Current assignee: Mitsubishi Pencil Co Ltd
Priority date: 2005-03-30
Filing date: 2005-03-30
Publication date: 2006-10-12

Abstract

PROBLEM TO BE SOLVED: To provide a writing plate which solves the problem that an image acquired from a variation of light penetration, the concentration of a drawing line are small from the structure since a material which constitutes a sheet material is composed of an inorganic pigment and a bonding agent, and which is easy to erase and writable for a brush drawing line, produces no dregs, has light weight, and can also carry refractility. SOLUTION: In the writing plate which is made by sticking porosity sheet layers made of resin and opaque and colored layers at least, writing down on the porosity sheet layer surface made of the resin with a transparent ink including water or an organic solvent, thereby impregnating the transparent ink to the porosity sheet and raising the light transmittance of the porosity sheet and making the color of the layers opaque underlayer and colored through the part of the written drawing line; the porosity sheet layers made of the resin consists of the surface of a diameter r1 of average passage whose relation of the diameter of the passage is r1>r2 and the surface of the diameter r2 of the average passage. The problem is solved by turning and sticking the surface of the average passage r2 to the opaque and colored layers. COPYRIGHT: (C)2007,JPO&INPIT

Description

本発明は、筆記板に関し、特に水または有機溶剤を含む透明インキで筆記することにより、筆記板表面に文字が現れ、乾燥とともに文字が消失する筆記板、に関する。 The present invention relates to a writing board, and more particularly to a writing board in which characters appear on the surface of the writing plate by writing with a transparent ink containing water or an organic solvent, and the characters disappear upon drying.

従来、筆記板としては、チョークで筆記する黒板や、インキを収納した筆記具で筆記するホワイトボードなどがある。また、磁性体をボード内に含ませて、筆記板表面を磁気ペンでなぞって筆記するボード等もある。
しかしながら、これらの筆記板は、消去し難かったり、重量が大きかったり、消しカスが出たり、描線の濃度が小さかったり、毛筆描線が書けないなどの欠点があった。
また、水で濡らすと透過性が変化して貼り合わせた着色台紙の画像が浮き出る水像シートが提案されている（例えば、特許文献１参照）。
また、非粘着層側側面に低屈折率顔料をバインダー樹脂に分散状態に固着させた、非吸水状態では不透明であるが、吸水状態で透明化する多孔質層を設けたシート材の、背面に粘着層を設けた水変色性粘着シートも提案されている（例えば、特許文献２参照）。 Conventionally, as a writing board, there are a blackboard for writing with chalk and a white board for writing with a writing instrument containing ink. There is also a board that includes a magnetic material in the board and traces the surface of the writing board with a magnetic pen.
However, these writing boards have drawbacks such as being difficult to erase, heavy in weight, erasing residue, low density of drawn lines, and inability to write brushed lines.
Further, there has been proposed a water image sheet in which the permeability changes when wetted with water, and the image of the colored mount that is pasted together emerges (see, for example, Patent Document 1).
In addition, on the back side of the sheet material provided with a porous layer that is opaque in the non-water-absorbing state but is transparent in the water-absorbing state, in which the low refractive index pigment is fixed to the binder resin in a dispersed state on the side surface of the non-adhesive layer A water-coloring adhesive sheet provided with an adhesive layer has also been proposed (see, for example, Patent Document 2).

特許文献１は、屈折率が１．７以下の白色顔料を主体として含む吸水性の塗布層が、透明なフィルムの片側表面に形成された不透明なフィルムと、着色された面に画像を有する台紙とを貼り合わせ、さらに前記塗布層に表面画像を設けてなる水像シートであるが、シートは、透明なフィルムの片側表面に白色顔料を主体として含む吸水性の塗布層を形成したものであり、その構造上、光の透過性変化から得られる透視される画像の濃度が小さいという欠点があった。
また、特許文献２は、常態では潜像状態にある像を、水を媒体として顕出させて視覚判別させる水変色性粘着シートに関するものであるが、そのシートの構造は、片側に粘着層を設けたシート材の非粘着層側の表面に、低屈折率顔料をバインダー樹脂により分散状態にて固着させた、非吸水状態では不透明であるが、吸水状態で透明化する多孔質層を配設したもので、シート材表面と多孔質層との間に着色層が設けられていること、多孔質層の一部に内在し、共存状態で撥水性樹脂層が配設されてなり、該撥水性樹脂層上に着色層が設けられていることを要件としている。
しかしながら、このシートの構造もシート材の表面に低屈折率顔料をバインダー樹脂に分散固着させたものであるために、特許文献１と同様の欠点がある。
特公平５−１５３８９号（特許請求の範囲等）特開２００２−１２９１１７号（特許請求の範囲等） Patent Document 1 discloses an opaque film in which a water-absorbing coating layer mainly containing a white pigment having a refractive index of 1.7 or less is formed on one surface of a transparent film, and a mount having an image on a colored surface Is a water image sheet in which a surface image is provided on the coating layer, and the sheet is formed by forming a water-absorbing coating layer mainly containing a white pigment on one surface of a transparent film. However, due to its structure, there is a drawback that the density of a see-through image obtained from a change in light transmittance is small.
Further, Patent Document 2 relates to a water-color-changeable pressure-sensitive adhesive sheet that visually reveals an image that is in a latent image state by using water as a medium, but the structure of the sheet has a pressure-sensitive adhesive layer on one side. On the surface of the non-adhesive layer side of the provided sheet material, a porous layer that is opaque in the non-water-absorbing state but transparent in the water-absorbing state is provided with a low refractive index pigment fixed in a dispersed state with a binder resin. Therefore, a colored layer is provided between the surface of the sheet material and the porous layer, and a water-repellent resin layer is provided in a part of the porous layer in a coexisting state. The requirement is that a colored layer is provided on the aqueous resin layer.
However, since the structure of this sheet is obtained by dispersing and fixing a low refractive index pigment to a binder resin on the surface of the sheet material, it has the same defects as in Patent Document 1.
Japanese Patent Publication No. 5-15389 (claims, etc.) JP 2002-129117 (Claims etc.)

本発明は、シート材を構成する材料が、樹脂製多孔質シートにより構成されているために、その構造から、光の透過性変化から得られる画像、描線の濃度が小さいという問題を解決し、消去しやすく、毛筆描線も書け、カスも出ず、重量が軽く、屈折性も付与することができる筆記板を提供することを目的とする。 In the present invention, since the material constituting the sheet material is constituted by a resin porous sheet, the structure solves the problem that the image obtained from the light transmission change, the density of the drawn line is small, An object of the present invention is to provide a writing board that can be easily erased, can write brush strokes, has no residue, is light in weight, and can be provided with refraction.

本発明者らは、上記課題等に鑑み、これを解決しようとするものであり、樹脂製多孔質シート層の平均流路径を大小に変化させ、平均流路径の小さい方の面を不透明かつ有色の層に向けて貼り合わせることによって、本発明を完成するに至ったものである。
すなわち、本発明のインキ組成物は、以下の（１）〜（５）によって構成される。
（１）少なくとも樹脂製多孔質シート層と不透明かつ有色の層とを貼り合わせてなり、水または有機溶剤を含む透明インキで樹脂製多孔質シート層面に筆記することにより、多孔質シートに透明インキを含浸させて多孔質シートの光透過率を上げることで、筆記した描線の部分を通して下地の不透明かつ有色の層の色を視認可能とした筆記板において、該樹脂製多孔質シート層が平均流路径ｒ１の面と、平均流路径ｒ２の面からなり、流路径の関係がｒ１＞ｒ２であり、平均流路径ｒ２の面を不透明かつ有色の層に向けて貼り合わせてなることを特徴とする筆記板。
（２）樹脂製多孔質シート層が、平均流路径ｒ１と平均流路径ｒ２の２枚の樹脂製多孔質シートからなる（１）に記載の筆記板。
（３）樹脂製多孔質シート層が、シートの厚み方向の平均流路径がｒ１からｒ２へと連続的に変化する１枚の樹脂製多孔質シートである（１）に記載の筆記板。
（４）樹脂製多孔質シート層の材質の屈折率が１．２〜１．８である（１）〜（３）に記載の筆記板。
（５）樹脂製多孔質シート層の気孔率が４０％以上である（１）〜（４）に記載の筆記板。 In view of the above-mentioned problems, the present inventors have attempted to solve this problem, and changed the average flow path diameter of the resin porous sheet layer to be larger or smaller so that the surface with the smaller average flow path diameter is opaque and colored. The present invention has been completed by bonding to the layer.
That is, the ink composition of the present invention is constituted by the following (1) to (5).
(1) At least a resin porous sheet layer and an opaque and colored layer are bonded together, and a transparent ink is added to the porous sheet by writing on the surface of the resin porous sheet layer with a transparent ink containing water or an organic solvent. In a writing board in which the color of the underlying opaque and colored layer is visible through the portion of the drawn lines by impregnating the porous sheet, the resin porous sheet layer has an average flow. The surface is composed of a surface having a path diameter r1 and a surface having an average flow path diameter r2. The relationship between the flow path diameters is r1> r2, and the surface having the average flow path diameter r2 is bonded to an opaque and colored layer. Writing board.
(2) The writing board according to (1), wherein the resin porous sheet layer is composed of two resin porous sheets having an average flow path diameter r1 and an average flow path diameter r2.
(3) The writing board according to (1), wherein the resin porous sheet layer is one resin porous sheet in which an average channel diameter in the thickness direction of the sheet continuously changes from r1 to r2.
(4) The writing board as described in (1)-(3) whose refractive index of the material of the resin-made porous sheet layer is 1.2-1.8.
(5) The writing board according to any one of (1) to (4), wherein the porosity of the resin porous sheet layer is 40% or more.

本発明は、前記のように構成されており、水または有機溶剤を含む透明インキで樹脂製多孔質シート層に筆記することで、筆記部分の光透過率が上がり、下地の色が浮き出て、鮮明な文字、描画として視認することができる。
また、表面の平均流路径が有色層と接触している裏面の平均流路径よりも大きいので、裏面側の毛管力が強くなり、溶剤を浸透させる力がさらに発現し、結果として有色層の溶剤濡れが向上して、文字、描画を鮮明に視認することができる。
さらには、透明インキに種々の有機溶剤を用いることにより、乾燥速度のコントロールをすることができ、筆記板上の文字、描画の表示時間を調節できる。
また、水または有機溶剤を含む透明インキで樹脂製多孔質シート層に筆記するので、毛筆文字も書けるとともに筆記カスも出ない。 The present invention is configured as described above, and by writing on the resin porous sheet layer with a transparent ink containing water or an organic solvent, the light transmittance of the writing part is increased, and the color of the base comes out. Visible as clear characters and drawing.
Further, since the average channel diameter on the front surface is larger than the average channel diameter on the back surface in contact with the colored layer, the capillary force on the back surface side becomes stronger, and the force to penetrate the solvent further develops. As a result, the solvent of the colored layer Wetting is improved so that characters and drawings can be clearly seen.
Furthermore, by using various organic solvents for the transparent ink, the drying speed can be controlled, and the characters on the writing board and the display time for drawing can be adjusted.
In addition, since writing is performed on the resin porous sheet layer with a transparent ink containing water or an organic solvent, writing brush characters and writing residue are not generated.

以下に、本発明を実施するための最良の実施形態を図面により詳しく説明するが、本発
明の形態はこれに限定されるものではない。
図１は、本発明第一実施例の筆記板の断面図であり、保護層（Ａ層）、平均流路径ｒ１の樹脂製多孔質シート層（Ｂ１層）、平均流路径ｒ２の樹脂製多孔質シート層（Ｂ２層）、不透明かつ有色の層（Ｃ層）の４つの層から構成され、樹脂製多孔質シート層（Ｂ１層）の平均流路径ｒ１と樹脂製多孔質シート層（Ｂ２層）２の平均流路径ｒ２の流路径の関係は、ｒ１＞ｒ２である。 The best mode for carrying out the present invention will be described below in detail with reference to the drawings. However, the form of the present invention is not limited to this.
FIG. 1 is a cross-sectional view of the writing board according to the first embodiment of the present invention, and includes a protective layer (A layer), a resin porous sheet layer (B1 layer) having an average flow path diameter r1, and a resin porous sheet having an average flow path diameter r2. It is composed of four layers, a porous sheet layer (B2 layer) and an opaque and colored layer (C layer), and the average flow path diameter r1 of the resin porous sheet layer (B1 layer) and the resin porous sheet layer (B2 layer) ) The relationship between the channel diameters of the average channel diameter r2 of 2 is r1> r2.

図２は、本発明の他の実施例の筆記板の断面図であり、保護層（Ａ層）、保護層に接する面の平均流路径ｒ１から有色層に接する面の平均流路径ｒ２へと連続的に平均流路径が変化する１枚の樹脂製多孔質シート層（Ｂ層）、不透明かつ有色の層（Ｃ層）の３つの層から構成され、樹脂製多孔質シート層（Ｂ層）の平均流路径ｒ１と平均流路径ｒ２の流路径の関係は、ｒ１＞ｒ２となっている。 FIG. 2 is a cross-sectional view of a writing board of another embodiment of the present invention, from the protective layer (A layer), the average flow path diameter r1 of the surface in contact with the protective layer to the average flow path diameter r2 of the surface in contact with the colored layer. The resin porous sheet layer (B layer) is composed of three layers, one resin porous sheet layer (B layer) whose average flow path diameter changes continuously, and an opaque and colored layer (C layer). The relationship between the average channel diameter r1 and the average channel diameter r2 is r1> r2.

本発明では、種々の樹脂製多孔質シートを用いることができる。樹脂製多孔質シートは、シートの中に空気が内包されていれば材質は特に限定されるものではないが、非着色である白色材料が好ましい。具体的には、ポリエチレン、ポリプロピレン、ポリエチレンテレフタレート、ポリカーボネート、エポキシ樹脂、ポリアセタール、酢酸セルロース、硝酸セルロース、セルロース、ポリウレタン、ナイロン、フッ素ポリマー、ポリフッ化ビニリデン、フッ素ポリマー親水化処理品等があげられ、２種類以上混合したものも使用できるが、シートを構成する材料単体または複合体の屈折率は、１．２〜１．８が好ましい。屈折率が１．２未満であると、シートの隠蔽性が乏しく、溶剤含浸前の筆記板の有色層を十分に隠蔽することができず、好ましくない。また、１．８より大きくなると、溶剤を浸透させても十分にシートの光透過性が発現せず、結果として文字、描画が十分に認識できず、好ましくない。
樹脂製多孔質シートの一枚のシートの厚みは、１μｍ〜５ｍｍが特に好ましい。１μｍ以下であると透過性が発現し、溶剤含浸前の有色層の隠蔽性が不十分になり、また５ｍｍ以上であると溶剤の浸透が不十分となり、文字が不鮮明となり、好ましくない。
樹脂製多孔質シートの気孔率は、４０％であることが望ましい。４０％未満であると、溶剤を含浸しても光透過率の向上が不十分で、結果として文字、描画が十分に認識できず、好ましくない。
樹脂製多孔質シートの平均流路径のサイズとしては、０．０５〜１００μｍが好ましい。０．０５μｍ以下になると、温度変化等で目詰まりを起こし、また、１００μｍ以上になると、溶剤含浸前の有色層の隠蔽性が悪くなり、好ましくない。 In the present invention, various resin porous sheets can be used. The material of the resin porous sheet is not particularly limited as long as air is included in the sheet, but a non-colored white material is preferable. Specific examples include polyethylene, polypropylene, polyethylene terephthalate, polycarbonate, epoxy resin, polyacetal, cellulose acetate, cellulose nitrate, cellulose, polyurethane, nylon, fluoropolymer, polyvinylidene fluoride, and fluoropolymer hydrophilized products. Although a mixture of two or more types can be used, the refractive index of the material alone or the composite constituting the sheet is preferably 1.2 to 1.8. If the refractive index is less than 1.2, the sheet is not sufficiently concealed, and the colored layer of the writing board before impregnation with the solvent cannot be sufficiently concealed. On the other hand, if it exceeds 1.8, the light transmittance of the sheet is not sufficiently exhibited even if the solvent is infiltrated, and as a result, characters and drawing cannot be sufficiently recognized, which is not preferable.
The thickness of one sheet of the resin porous sheet is particularly preferably 1 μm to 5 mm. If the thickness is 1 μm or less, the transparency is exhibited, and the concealability of the colored layer before impregnation with the solvent becomes insufficient. If the thickness is 5 mm or more, the penetration of the solvent becomes insufficient, and the characters become unclear.
The porosity of the resin porous sheet is desirably 40%. If it is less than 40%, the light transmittance is not sufficiently improved even when impregnated with a solvent, and as a result, characters and drawing cannot be sufficiently recognized, which is not preferable.
The size of the average flow path diameter of the resin porous sheet is preferably 0.05 to 100 μm. If it is 0.05 μm or less, clogging occurs due to a temperature change or the like, and if it is 100 μm or more, the concealability of the colored layer before impregnation with the solvent is deteriorated, which is not preferable.

有色層は、色を認識できるように着色されていれば、特に限定されるものではない。材質は、木、プラスチック、無機物等を用いることができ、着色は黒、緑、青などがあげられる。薄いプラスチックシートを用いて、屈曲性を持たせることもできる。 The colored layer is not particularly limited as long as it is colored so that the color can be recognized. The material can be wood, plastic, inorganic material, etc., and the coloring is black, green, blue and the like. A thin plastic sheet can be used to provide flexibility.

本発明は、必要に応じて樹脂製多孔質シート層に保護層を設けることができる。この保護層は、筆記板表面の傷や汚れを防止するためのものである。更に、この保護層は透明インキを透過出来るように多孔質のシートであることが必要であり、その平均流路径をｒ３とするとｒ３＞ｒ１であることが望ましい。 In the present invention, a protective layer can be provided on the resinous porous sheet layer as necessary. This protective layer is for preventing scratches and dirt on the surface of the writing board. Furthermore, this protective layer needs to be a porous sheet so that transparent ink can permeate, and it is desirable that r3> r1 when the average channel diameter is r3.

また、本発明の筆記板は、有色層の裏面に粘着層や磁石シート層を設けることができる。これによって、筆記板を壁面や好みの箇所に貼り付けて使用することができる。 Moreover, the writing board of this invention can provide an adhesion layer and a magnet sheet layer in the back surface of a colored layer. Thereby, a writing board can be affixed and used for a wall surface or a favorite location.

さらに本発明は、この筆記板の付属品として、水または有機溶剤を含む透明インキを収納した筆記具、あるいは毛筆をセットにして用いることができる。 Furthermore, the present invention can be used as a set of a writing instrument or a brush that contains a transparent ink containing water or an organic solvent as an accessory of the writing board.

また、本発明による筆記板は、立て看板、毛筆練習シート、掲示板、メモ用シート等種々の応用展開が考えられ、その展開用途は特に限定されない。 In addition, the writing board according to the present invention can be applied in various applications such as a standing signboard, a brush writing practice sheet, a bulletin board, a memo sheet, and the use of the writing board is not particularly limited.

次に、本発明を具体的な実施例に基づき更に詳細に説明するが、本発明は下記実施例に限定されるものではない。 Next, the present invention will be described in more detail based on specific examples, but the present invention is not limited to the following examples.

（実施例１）
Ａ層：ポリカーボネイト多孔質シート（Ｗｈａｔｍａｎ社製）
（厚み：１０μｍ、平均流路径：３μｍ）
Ｂ１層：フッ素ポリマー親水化処理膜多孔質シート（日本ミリポア社製）
（厚み：３μｍ、平均流路径：２μｍ、気孔率：８０％、屈折率：１．４〜１．６）
Ｂ２層：フッ素ポリマー親水化処理膜多孔質シート（日本ミリポア社製）
（厚み：１μｍ、平均流路径：１μｍ、気孔率：８０％、屈折率：１．４〜１．６）
Ｃ層：不透明黒色アクリル板（アクリサンデー社製）
（厚み：２ｍｍ）
（実施例２）
Ａ層：ポリカーボネイト多孔質シート（Ｗｈａｔｍａｎ社製）
（厚み：１０μｍ、平均流路径：３μｍ）
Ｂ層：フッ素ポリマー親水化処理膜多孔質シート（日本ミリポア社製）
（厚み：１μｍ、平均流路径：１μｍ、気孔率：８０％、屈折率：１．４〜１．６）
Ｃ層：不透明黒色アクリル板（アクリサンデー社製）
（厚み：２ｍｍ）
（実施例３）
Ａ層：ポリカーボネイト多孔質シート（Ｗｈａｔｍａｎ社製）
（厚み：１０μｍ、平均流路径：３μｍ）
Ｂ層：ＰＥＴパウダー２５μｍ品（セイシン企業社製）
（厚み：５０μｍ、気孔率：５５％、屈折率：１．４〜１．６）
Ｃ層：不透明黒色アクリル板（アクリサンデー社製）
（厚み：２ｍｍ）
（実施例４）
Ａ層：ポリカーボネイト多孔質シート（Ｗｈａｔｍａｎ社製）
（厚み：１０μｍ、平均流路径：３μｍ）
Ｂ層：ポリオレフイン＋無機フイラー複合シート（日本無機社製）
（厚み：４０μｍ、平均流路径：０．２μｍ、気孔率：８０％、屈折率：１．４〜１．６）
Ｃ層：不透明黒色アクリル板（アクリサンデー社製）
（厚み：２ｍｍ）
（実施例５）
Ａ層：ポリカーボネイト多孔質シート（Ｗｈａｔｍａｎ社製）
（厚み：１０μｍ、平均流路径：３μｍ）
Ｂ層：エポキシ樹脂１０ｇとイソホロンジアミン１ｇとリモネン３ｇと０．１〜２μｍの粒径分布を有する塩化ナトリウム２ｇとをよく混ぜ合わせ、５０μｍの厚みになるようにフッ素コート板にコーティングした。これを硬化と粗大粒子の沈降を発現させるために２週間静置した後、フッ素コート板からはがして、エタノールでリモネンを、また水で塩化ナトリウムを洗い流した後、厚み３０μｍ、片面の流路径が０．１μｍ、もう片面の流路径が２μｍの連続的に流路径が変化する多孔質シートを得た。
Ｃ層：不透明黒色アクリル板（アクリサンデー社製）
（厚み：２ｍｍ） Example 1
A layer: Polycarbonate porous sheet (manufactured by Whatman)
(Thickness: 10 μm, average channel diameter: 3 μm)
B1 layer: Fluoropolymer hydrophilized membrane porous sheet (Nippon Millipore)
(Thickness: 3 μm, average channel diameter: 2 μm, porosity: 80%, refractive index: 1.4 to 1.6)
B2 layer: fluoropolymer hydrophilic treatment membrane porous sheet (manufactured by Nihon Millipore)
(Thickness: 1 μm, average channel diameter: 1 μm, porosity: 80%, refractive index: 1.4 to 1.6)
C layer: Opaque black acrylic board (Acrysande)
(Thickness: 2mm)
(Example 2)
A layer: Polycarbonate porous sheet (manufactured by Whatman)
(Thickness: 10 μm, average channel diameter: 3 μm)
B layer: Fluoropolymer hydrophilized membrane porous sheet (Nippon Millipore)
(Thickness: 1 μm, average channel diameter: 1 μm, porosity: 80%, refractive index: 1.4 to 1.6)
C layer: Opaque black acrylic board (Acrysande)
(Thickness: 2mm)
(Example 3)
A layer: Polycarbonate porous sheet (manufactured by Whatman)
(Thickness: 10 μm, average channel diameter: 3 μm)
B layer: PET powder 25 μm product (manufactured by Seishin Enterprise Co., Ltd.)
(Thickness: 50 μm, porosity: 55%, refractive index: 1.4 to 1.6)
C layer: Opaque black acrylic board (Acrysande)
(Thickness: 2mm)
Example 4
A layer: Polycarbonate porous sheet (manufactured by Whatman)
(Thickness: 10 μm, average channel diameter: 3 μm)
B layer: Polyolefin + inorganic filler composite sheet (Nippon Inorganic Co., Ltd.)
(Thickness: 40 μm, average channel diameter: 0.2 μm, porosity: 80%, refractive index: 1.4-1.6)
C layer: Opaque black acrylic board (Acrysande)
(Thickness: 2mm)
(Example 5)
A layer: Polycarbonate porous sheet (manufactured by Whatman)
(Thickness: 10 μm, average channel diameter: 3 μm)
Layer B: 10 g of epoxy resin, 1 g of isophoronediamine, 3 g of limonene and 2 g of sodium chloride having a particle size distribution of 0.1 to 2 μm were mixed well and coated on a fluorine-coated plate to a thickness of 50 μm. This was left to stand for 2 weeks in order to develop hardening and settling of coarse particles, then peeled off from the fluorine-coated plate, washed with limonene with ethanol and sodium chloride with water, and then the thickness of the channel on one side was 30 μm. A porous sheet having a continuous flow path diameter of 0.1 μm and a flow path diameter of 2 μm on the other side was obtained.
C layer: Opaque black acrylic board (Acrysande)
(Thickness: 2mm)

（比較例１）市販の黒板に市販のチョークにて筆記
（比較例２）市販のホーロー製ホワイトボードに市販のホワイトボード用マーカーにて筆記
（比較例３）市販の磁気ボードに付属の磁気ペンにて筆記 (Comparative Example 1) Writing with a commercially available chalk on a commercially available blackboard (Comparative Example 2) Writing with a commercially available whiteboard marker on a commercially available enamel whiteboard (Comparative Example 3) Magnetic pen attached to a commercially available magnetic board Written in

（試験例）
実施例にもとづいて作成した筆記板に、インキとしてプロピレングリコールモノメチルエーテル約４ｇを充填した中綿式サインペン（三菱鉛筆製：Ａ−５０Ｅ）にて筆記して、描線濃度、自然乾燥により描線が消去された時のカスの量を確認した。
比較例については、描線濃度、各筆記板に付属のイレーザーにて描線を消去した時のカスの量を確認した。
また、各筆記板を同じ大きさにした時の重量を比較し、結果を下記表１に示した。 (Test example)
The writing board created based on the example was written with a cotton pad sign pen (Mitsubishi Pencil Co., Ltd .: A-50E) filled with about 4 g of propylene glycol monomethyl ether as ink, and the drawing line was erased by drawing density and natural drying. The amount of waste was confirmed.
About the comparative example, the amount of dregs when the drawn line density and the drawn line were erased with the eraser attached to each writing board were confirmed.
Moreover, the weight when making each writing board into the same magnitude | size was compared, and the result was shown in following Table 1.

カスの量の評価基準：
○：まったく出ない。
△：少し出る。
×：多い。 Evaluation criteria for amount of waste:
○: Not at all.
Δ: Slightly appears.
X: Many.

描線濃度の評価基準：
○：濃い。
△：やや薄い。
×：著しく薄い。 Evaluation criteria for stroke density:
○: Dark.
Δ: Slightly thin
X: Remarkably thin.

３０ｃｍ×４５ｃｍ換算にした時の重量：
○：２００ｇ以下。
△：２００ｇ以上５００ｇ未満。
×：５００ｇ以上。 Weight when converted to 30cm x 45cm:
○: 200 g or less.
Δ: 200 g or more and less than 500 g.
X: 500 g or more.

実施例１〜５、及び比較例１〜３の調査結果より、本発明の実施例１〜５は、市販の筆記板１〜３に較べて、カスも全く出ず、描線濃度も濃く、しかも重量も軽いことが判明した。 From the investigation results of Examples 1 to 5 and Comparative Examples 1 to 3, Examples 1 to 5 of the present invention have no residue at all compared to the commercially available writing boards 1 to 3, and the drawn line density is high. It turned out to be light in weight.

本発明の筆記板第１実施例の断面図である。It is sectional drawing of the writing board 1st Example of this invention. 本発明の筆記板の他の実施例の断面図である。It is sectional drawing of the other Example of the writing board of this invention.

Explanation of symbols

Ａ：保護層
Ｂ：樹脂製多孔質シート層
Ｂ１：樹脂製多孔質シート層
Ｂ２：樹脂製多孔質シート層
Ｃ：有色層

A: Protective layer B: Resin porous sheet layer B1: Resin porous sheet layer B2: Resin porous sheet layer C: Colored layer

Claims

At least a resin porous sheet layer and an opaque and colored layer are bonded together, and the porous sheet is impregnated with a transparent ink by writing on the surface of the resin porous sheet layer with a transparent ink containing water or an organic solvent. By increasing the light transmittance of the porous sheet, it is possible to visually recognize the color of the underlying opaque and colored layer through the portion of the drawn line, and the porous sheet made of resin has an average flow path diameter r1 A writing board comprising a surface and a surface having an average channel diameter r2, wherein the relationship between the channel diameters is r1> r2, and the surface of the average channel r2 is bonded to an opaque and colored layer.

The writing board according to claim 1, wherein the resin porous sheet layer is composed of two resin porous sheets having an average flow path diameter r1 and an average flow path diameter r2.

2. The writing board according to claim 1, wherein the resin porous sheet layer is a single resin porous sheet whose average flow path diameter in the thickness direction of the sheet continuously changes from r 1 to r 2.

The writing board according to claim 1, wherein a refractive index of a material of the resin porous sheet layer is 1.2 to 1.8.

The writing board according to claim 1, wherein the porosity of the resin porous sheet layer is 40% or more.