HOLDER FOR KEEPING PURPOSE AND REPLENISHING SHEET-FORM MATTER

Abstract: A holder for keeping purpose capable of holding a sheet-form matter to be kept in such a manner that the edge of said sheet-form matter may be removably fixed to the inner surface at the back of the holder without requiring punching or any other attaching means, in which soft polyurethane elastomer continuously high in viscosity at room temperature and contamination-free is attached to the inner surface at the back of the holder and the edge of the sheet-form matter is stuck to and held by said polyurethane elastomer; and a replenishing sheet-form matter to be used in said holder.

Description: TECHNICAL FIELD This invention relates to a filing device comprising a front cover, a spine, and a rear cover, for detachably securing documents, documents pouches, photo-mounting sheets, postcards and all other types of sheet-like materials at their edges to the inner side of the spine, and also relates to supplemental sheet-like materials to be used with said filing device. BACKGROUND ART As filing devices to file and store sheet-like materials such as documents, there have been generally used such binders that sheet-like materials having punching holes are pierced by binding elements or binding pipes provided at a filing attachment secured to the inner side of a rear cover and fixed by a fixing element having receiving holes for binding elements or by a fixing element secured to the inner side of a front cover and provided with insertion pipes to be inserted in the binding pipes. The above mentioned binders do not slip the documents filed therein and they are convenient for storage. However, they have the drawbacks that there is the necessity of going to the trouble of forming punching holes every time the document is filed, and that documents which can not accept the punching holes can not be filed. In addition, since free space is required for punching the holes, documents having no such free space had to be photocopied to create such free space. Further, when documents are removed from the middle of the binder, and are then re-inserted, the documents located in front of the documents being removed also have to be removed and re-inserted every time, making removal and re-insertion of documents difficult. DISCLOSURE OF INVENTION It is therefore an object of the present invention to provide a filing device which can detachably secure sheet-like materials to be filed at their edges to the inner side of a spine with a reliable securing and filing manner without forming punching holes, and also to provide supplemental sheet-like materials to be used with said filing device. One filing method which requires no punching holes is attained by using adhesives or pressure-sensitive adhesives, and there has been proposed a filing device for securing sheet-like materials such as postcards by adhering front or rear edges or side edges thereof by using adhesives or pressure-sensitive adhesives. However, once attached, they cannot be removed, and if they are forcibly removed, the bonded area peels off and remains on the adhesives, and they can not be readhered or re-filed. There is also the problem that the adhesive power diminishes due to gradual hardening of the adhesive substance or the adhesion of dust. EP-A-246852 discloses a thin flexible sheet for binding loose pages together having a band of pressure sensitive adhesive coated along one longitudinal edge and protected by a release liner. Accordingly, in the present invention, conventional adhesives or pressure-sensitive adhesives were put aside and a search was made for an adherent substance which has a high adhesion property sufficient to secure sheet-like materials at their edges, and which does not peel the edges of the sheet-like materials and which is not transferred to the edges of the sheet-like materials when the sheet-like materials are detached therefrom in resistance to the adhesion power. As a result, it has been found that polyurethane elastomer has the adaptability to that purpose and the present invention has been accomplished. Polyurethane elastomer is very versatile in its properties. Selected in the present invention is a soft polyurethane elastomer having continuous high adhesion at room temperature, non-staining property, which means that the adhesion is not spoiled by dust because dust adhered thereto can be easily removed by wiping off with a wet cloth, and relative pliability, and consequently it is found that said polyurethane elastomer is the best adherent substance which can detachably secure sheet-like materials such as documents at their edges. A preferred adhesive strength for such a polyurethane elastomer used for this purpose would be 450 g/cm for 180° peeling force, and 115 g/cm for a 90° peeling force. The pliability is preferred to be less than 10° in hardness. The adhesion of polyurethane elastomer varies depending on the proportion of polyol and isocyanate. It is advisable to select the components and proportions thereof from reactive mixtures with excess polyol in order to obtain the desired adhesion suitable for the purpose of this invention. Selection shall be made from the view points of not only adhesion, but also other factors such as non-likelihood of causing paper smears, transparency, non-yellowing, durability and so forth. In the formation of polyurethane elastomer, the reaction may be accelerated by using curing agents and cross-linking agents and either one-shot method or pre-polymer method may be adopted. The filing device provided by this invention is constructed by securing the above polyurethane elastomer to the inner side of a spine. The present invention provides a filing device comprising a front cover, a spine, a rear cover and a non-staining soft polyurethane elastomer having continuous high adhesion at room temperature, the adhesive strength thereof being at least 450g/cm for a 180° peeling force and at least 115g/cm for a 90° peeling force, wherein the elastomer is secured to the inner side of the spine so that sheet-like materials such as documents may be detachably secured and held at their edges. In order to secure the soft polyurethane elastomer to the inner side of the spine, polyurethane elastomer liquid may be directly applied to and hardened on the inner side of the spine so that the polyurethane elastomer is secured firmly to and integrated with the inner side of the spine. Polyurethane elastomer liquid may be also applied to and hardened on a carrying sheet to prepare the polyurethane elastomer with a carrying sheet. In this case said carrying sheet is secured to the inner side of the spine. Further polyurethane elastomer liquid may be formed into a sheet which is secured to the inner side of the spine as it is. When the polyurethane elastomer liquid is directly applied to and hardened on the inner side of the spine so as to be integrated therewith, it is preferred that a securing surface at the inner side of the spine is warped so that the polyurethane elastomer adhered thereto is also warped, because the adhesive area of the edges of the sheet-like materials increases. An increase in the adhesive area can also be achieved if the securing surface of the spine is formed irregularly with parallel grooves extending in the lengthwise direction of the spine so that the polyurethane elastomer is also formed irregularly. The securing surface of the polyurethane elastomer may be either the inner side itself of the spine or a surface of another element secured to the inner side of the spine. The carrier for the polyurethane elastomer may be a sheet-like material made of various materials including cloth, paper, non-woven fabric, or a foamed substance and plastics may be used. Polyurethane elastomer liquid is applied to the carrier by impregnating, coating, pouring, etc., and is hardened so as to be integrated therewith. Polyurethane elastomer firmly bonds integrally with the carrier through its own adhesion. An adhesive agent may be used for adhesion between the carrier and the inner side of the spine, but when the carrier is impregnated with polyurethane elastomer, or when polyurethane elastomer is applied to both sides of the carrier, the carrier can be affixed through the adhesiveness of the polyurethane elastomer without using another adhesive agent. Supplementary affixing means may be adopted. For example, approximately U-shaped clasps may be used to clamp the upper and lower ends of the carrier and flat portions of said clasps are secured to the spine by means of rivets. When polyurethane elastomer liquid is directly applied to the inner side of the spine and is hardened to be integrated with the spine, supplementary affixing means are scarcely needed because firm adhesion is obtained with the inner side of the spine. Where polyurethane elastomer is formed into a sheet and then secured to the inner side of the spine, it can be firmly affixed to the inner side of the spine through the strong adhesiveness of the polyurethane elastomer. Needless to say, supplementary affixing means may be adopted. Where the filing device is formed with a polyolefin resin such as polypropylene or polyethylene which is inferior in adhesion to polyurethane elastomer, a polyurethane elastomer sheet can not be firmly secured to the inner side of the spine and it is also the same when the polyurethane elastomer with a carrier is secured thereto by means of the adhesion of the polyurethane elastomer applied to the carrier. Therefore, when a number of sheet-like materials are attached and stored, there is a possibility that the polyurethane elastomer sheet or the polyurethane elastomer with a carrier might peel off and drop from the spine. However, it was found that if the surface of the inner side of the spine is coated with metal foil, pigment foil or silk printing ink, or is surface-treated using photogravure or offset lithography, strong adhesion with the polyurethane elastomer is obtained. Therefore, where polyurethane elastomer is affixed directly to the inner side of the spine, or when polyurethane elastomer with a carrier is affixed thereto via polyurethane elastomer, it is desired that the surface of the inner side of the spine be coated with metal foil, pigment foil or silk printing ink, or be surface-treated using photogravure or offset lithography. If the plastic material such as polypropylene constituting the spine is processed with corona discharge, then the metal foil, pigment foil or silk printing ink can be strongly coated and the surface treating by photogravure or offset lithography can be also accomplished strongly. As these surface processing materials and polyurethane elastomer strongly adhere to each other, even when a number of sheet-like materials are attached and stored, the polyurethane elastomer sheet or the polyurethane elastomer with a carrier does not peel off and fall out of the spine. A filing device having the polyurethane elastomer secured to the inner side of the spine as mentioned above can secure and hold the sheet-like materials such as documents firmly without causing easy separation and without forming punching holes to the materials by virtue of the firm adhesion of the edges of the materials pressed against the polyurethane elastomer. Unlike the case where conventional adhesives or pressure-sensitive adhesives are used, the sheet-like materials can be easily detached as the need arises. Where polyurethane elastomer liquid is applied to the inner side of the spine and hardened thereon, when the inner side is warped or is formed irregularly with parallel grooves extending in the lengthwise direction of the spine, the surface of the polyurethane elastomer also becomes warped or irregular and thereby the adhesive area is increased, so that the sheet-like materials can be hold in a good condition. Further, where polyurethane elastomer is carried on a sheet of cloth, paper, non-woven fabric or a foamed substance, firmness can be given to the polyurethane elastomer and a decorative effect can be expected because the pattern or the like of the carrier can be seen. Moreover, in the case of a foamed substance, when the sheet-like material is pressed and inserted into the polyurethane elastomer until the edge reaches a carrier sheet, the elasticity of the foamed substance allows good contact of the edge with the substance, so that the adhesive holding power is increased. Where a carrier is used, if a plastic sheet with innumerable spike-like protrusions formed on its surface is used as a carrier onto which polyurethane elastomer liquid is applied and hardened, sheet-like materials can be more securely held by both the adhesiveness of the polyurethane elastomer and the frictional grip between the spike-like protrusions. Further, if a plastic sheet with innumerable three-dimensional protrusions in the shape of circular cones, trapezoidal circular cones, pyramids or trapezoidal pyramides formed in the lengthwise and widthwise direction is used to carry the polyurethane elastomer around and on the protrusions, the sheet-like material inserted between the protrusions adheres to the polyurethane elastomer between the protrusions at the edge, and also adheres to the polyurethane elastomer carried around the protrusions at a slightly inward portion from the edge. Therefore, it can be said that adhesion is made not only at the edge of the sheet-like material but is made almost at a plane surface of the material, which makes the adhesion extremely strong. In the alignment of the innumerable protrusions in the lengthwise direction of the plastic sheet, if adjacent protrusions are slightly shifted in the widthwise direction of the sheet, the number of protrusions contacting with a slightly inward portion of the sheet-like material is increased and thereby the adhesive holding becomes more effective. There are no specific limits to the shape of the protrusions. However, if the base is made larger, enough strength can be given to the protrusions so they are not bent, and besides the slightly inward portion of the sheet-like material can be adhered to the protrusions more easily. Further, if the protrusions are of a three-dimensional shape which tapers toward the top, insertion of sheet-like materials become easy. Where the carrier is not used and the polyurethane elastomer sheet is directly affixed to the inner side of the spine, it is preferable to form protrusions on its surface. Such polyurethane elastomer sheets with protrusions can be easily obtained, for example, by pouring and forming polyurethane elastomer liquid in a silicone mold. In this case, it is preferable that the protrusions are formed like a trapezoidal pyramid or trapezoidal circular cone having the tops of slightly large dimension, because there is a possibility of the protrusion top bending if they are too small. In addition to the above filing device wherein the sheet-like material is inserted and held by adhesion, the present invention provides another type of filing device wherein another type of sheet-like materials such as photo-mounting sheets, document pouches or the like are affixed to the polyurethane elastomer secured to the spine in advance. In this case, it is preferable that the edges of these sheet-like materials are coated with metal foil, pigment foil or silk printing ink, or surface-treated using photogravure or offset lithography, because strong adhesion is required in this type of filing device. In addition, such a filing device is usually provided with additional sheet-like materials for supplementary use. If such additional sheet-like materials are also coated with metal foil, pigment foil or silk printing ink or surface-treated using photogravure or offset lithography on the filing edge, firm adhesion is obtained. In either case, the length of polyurethane elastomer at the inner side of the spine need not cover the whole length of the spine. Various forms may be adopted, including coverage of the center only or both ends only. BRIEF DESCRIPTION OF DRAWINGS Fig. 1 is a sectional view of a filing device constructed in accordance with the present invention; Fig. 2 is a sectional view of another embodiment in which the adhesion surface is warped; Fig. 3 is a sectional view of yet another embodiment in which the adhesion surface is irregular; Figs. 4 through 6 are sectional views of an embodiment in which a polyurethane elastomer with a carrier is employed; Fig. 7 is a sectional view of an embodiment in which a carrier with innumerable spike-like protrusions is employed; Fig. 8 is a sectional view of an embodiment in which synthetic resin sheets which work as guides for filing the sheet-like materials are provided; Fig. 9 is an enlarged sectional partial view of an embodiment in which a plastic sheet with protrusions is used as a carrier; Fig. 10 is a sectional view of an embodiment showing a different manner of adhesion to the spine; Fig. 11 is a schematic plan view showing representative examples of the alignment of protrusions as (A), (B) and (C); Fig. 12 is a sectional view of another filing device employing a plastic sheet with protrusions as a carrier; Fig. 13 is a sectional view of an embodiment employing a polyurethane elastomer sheet with protrusions. BEST MODE FOR CARRYING OUT THE INVENTION Fig. 1 is a sectional view of a filing device constructed in accordance with the present invention and shows a binder-type filing device comprising a front cover 1, spine 2 and rear cover 3. 4 denotes a polyurethane elastomer secured to the inner side of the spine 2 and is a soft polyurethane elastomer having continuous high adhesive strength at room temperature, which is non-staining and relatively pliable. The polyurethane elastomer 4 may have an adhesive strength of more than 450 g/cm for 180° peeling force and more than 115 g/cm for 90 ° peeling force, and preferably a hardness of less than 10°. In the case where the peeling force is weaker than the above, the adhesive holding strength of the sheet-like materials is inferior and when the hardness is higher than the above, the adhesive strength of the edges of the sheet-like materials becomes weak. Figs. 2 and 3 show embodiments in which the securing surface of the polyurethane elastomer 4 is not flat. Fig. 2 shows an embodiment with a warped surface, while Fig. 3 shows an embodiment with an irregular surface having parallel grooves extending in the lengthwise direction of the spine 2. In these embodiments, a polyurethane elastomer liquid was directly poured and hardened in a mold which was set on the securing surface of the spine. However,a polyurethane elastomer may be formed into a sheet and then secured by its own adhesiveness in the embodiments in Figs. 2 and 3. Figs. 4 through 6 show embodiments in which a polyurethane elastomer 4 is carried on a sheet-like material 5 made of cloth, paper, non-woven fabric or a foamed substance. Fig. 4 shows the impregnated embodiment and Fig. 5 shows the embodiment in which both sides of the material 5 are coated. In either embodiment, the adhesiveness of the polyurethane elastomer is utilized to secure the sheet-like material 5. Fig. 6 is an embodiment where the polyurethane elastomer is applied to the front surface of the sheet-like material 5 which is secured to the inner side of the spine 2 by adhesive agent 6. Fig. 7 is an embodiment where the polyurethane elastomer 4 is carried by a synthetic resin sheet 8 having innumerable spike-like protrusions 7. Fig. 8 shows an embodiment where synthetic resin sheets 9 which work as guides for filing the sheet-like materials are provided between the spine and the front and rear covers. 10 indicates hinges formed between the spine and the front and rear covers. Fig. 9 shows yet another embodiment. 11 is a plastic sheet secured to the inner side of the spine 2, which has innumerable protrusions 12 of a three-dimensional circular conical shape in the lengthwise and widthwise direction thereof. As shown in Fig. 11, said innumerable protrusions 12 are slightly shifted in the widthwise direction of the sheet in the alignment of the protrusions in the lengthwise direction of the sheet. Namely, in the alignment (A) of Fig. 11, three or four protrusions 12 are aligned widthwise, and adjacent lengthwise protrusions are slightly shifted in the widthwise direction of the sheet. In the alignment (B), four or five protrusions 12 have a bias alignment in the widthwise direction and adjacent lengthwise protrusions are also slightly shifted in the widthwise direction of the sheet. In the alignment (C), four or five protrusions 12 aligned widthwise in a zigzag fashion are slightly shifted in the widthwise direction relative to adjacent lengthwise protrusions. These alignment of protrusions are only examples. Any alignment may provide good adhesion as long as the innumerable protrusions aligned lengthwise and widthwise are slightly shifted in the widthwise direction of the sheet relative to adjacent lengthwise protrusions and a slightly inward portion from the edge of the sheet-like material contacts with the protrusions when the sheet-like material is inserted therebetween. In Fig. 9, 13 is a polyurethane elastomer carried on the protrusions of the above plastic sheet 11. Said polyurethane elastomer 13 is, as shown in the drawing, carried on the protrusions 12 of the plastic sheet 11 and the surface forming the protrusions. When the sheet-like material 14 is inserted between the protrusions 12, its edge is secured to the polyurethane elastomer between the protrusions and at the same time the portion slightly inward from the edge is also secured to the polyurethane elastomer carried on the protrusions. Therefore, the adhesion is made not only at the edge of the sheet-like material but is made almost at a plane surface of the material, so that the securing condition is extremely strong. Fig. 10 shows another embodiment of a filing device in accordance with the present invention. Polyurethane elastomer 13 is applied not only to the protrusion surface of plastic sheet 11 but also to its back side, so that the plastic sheet 11 carrying the polyurethane elastomer may be secured to the inner side of the spine 2 with said polyurethane elastomer. In this embodiment, in order to secure the plastic sheet 11 strongly, gold foil is deposited at the inner side of the plastic spine 2 as a metal foil 15, and transparent plastic sheet 11 is secured to the metal foil 15 with the polyurethane elastomer. Thus, using the property of the metal foil which strongly adheres to the spine 2 and the polyurethane elastomer, the plastic sheet 11 is strongly secured to the spine 2. In this way, even if a number of sheet-like materials are fixed and held, an adhesion which can sufficiently handle their weight can be obtained, and there can be provided a filing device in which there is no possibility of documents coming out with the plastic sheet when it is carried around. Further, as the glow of the gold foil can be seen through the transparent plastic sheet 11, the securing portion appears attractive. In order to secure the polyurethane elastomer to the plastic sheet, the polyurethane elastomer liquid is poured in the cavity of a silicone mold having holes slightly larger than the protrusions of the plastic sheet and is hardened after the plastic sheet is set. In order to secure the polyurethane elastomer to the back side of the plastic sheet, the polyurethane elastomer liquid may be poured over the sheet again and hardened. Fig, 12 shows yet another embodiment. This embodiment shows a filing device in which a sheet-like material 16 in the shape of a document pouch is secured to the polyurethane elastomer 13 of the plastic sheet 11 in advance. In this case, in order to obtain strong adhesion to the polyurethane elastomer, the sheet-like material 16 is coated with a metal foil 17 at its edge, as in the above embodiment, so that even if a number of documents are stored in the sheet-like pouch, there is no possibility that the sheet-like material will come off the polyurethane elastomer. 18 indicates an adhesive agent. Fig. 13 shows yet another embodiment where the polyurethane elastomer is formed into a sheet 19 and is secured to the inner side of the spine 2. This polyurethane elastomer sheet 19 has innumerable protrusions 20 of a three-dimensional trapezoidal pyramid shape in the lengthwise and widthwise directions of the sheet. As in Fig. 11, the innumerable protrusions 20 are so aligned that adjacent lengthwise protrusions are slightly shifted in the widthwise direction. The shape of the protrusions is a three-dimensional trapezoidal pyramid in order to prevent, to the extent possible, bending of the tops. Various other shapes may be adopted, including trapezoidal circular cones. This polyurethane elastomer sheet 19 is formed by pouring polyurethane elastomer liquid into a silicone mold. In this case as well, when sheet-like materials 14 are inserted between protrusions 20, the sheet edge is secured to the polyurethane elastomer between the protrusions and at the same time the slightly inward portion from the edge is also secured to the protrusions. Therefore, the adhesion is made not only at the edge of the sheet-like material but is made almost at a plane surface of the material, so that the securing condition is extremely strong. 21 indicates metal foil deposited onto the inner side of the plastic spine 2. The structure shown in the above embodiments are only examples of filing devices provided by this invention, which naturally are not limited to these. INDUSTRIAL APPLICABILITY As described above, this invention provides a filing device which can secure and hold various sheet-like materials including documents, document pouches, photo-mounting sheets and postcards, without forming punch holes, by pressing their edges onto the polyurethane elastomer on the spine, and allows easy removal of documents by pulling them as the need arises. Thus, the present invention provides a filing device which allows easy securing and holding and easy detaching of the sheet-like materials. This invention also offers the benefit that when a sheet-like material held in the middle is removed and re-inserted, the sheet-like material to be removed can be directly removed and re-inserted. Further, when the polyurethane elastomer is used, the dust on its surface can be easily wiped off with a wet cloth, and the original adhesiveness is recovered when dry so that the polyurethane elastomer does not lose its adhesive strength. Thus, the filing device of the present invention has wide applicability.

Claims: A filing device comprising a front cover (1), a spine (2), a rear cover (3) and a non-staining soft polyurethane elastomer (4) having continuous high adhesion at room temperature, the adhesive strength thereof being at least 450g/cm for a 180° peeling force and at least 115g/cm for a 90° peeling force, wherein the elastomer is secured to the inner side of the spine (2) so that sheet-like materials such as documents may be detachably secured and held at their edges. A filing device as claimed in claim 1, wherein a securing surface for the polyurethane elastomer (4) at the inner side of the spine (2) is warped. A filing device as claimed in claim 1, wherein a securing surface for the polyurethane elastomer (4) is formed irregularly with parallel grooves extending in the lengthwise direction of the spine (2). A filing device as claimed in claim 1, wherein a polyurethane elastomer (4) with a carrier is secured to the securing surface of the spine (2), said polyurethane elastomer (4) with a carrier being obtained by impregnating or coating a polyurethane elastomer liquid on a sheet (5) of cloth, paper, non-woven fabric or a foamed substance. A filing device as claimed in claim 4, wherein the polyurethane elastomer (4) with a carrier is secured to the inner side of the spine (2) by polyurethane elastomer (4) affixed to the back side of the sheet and the inner side of the plastic spine (2) is coated with metal foil, pigment foil or silk printing ink or is surface-treated using photogravure or offset lithography. A filing device as claimed in claim 1, wherein the polyurethane elastomer (13) is carried on a plastic sheet (11) having innumerable protrusions (12) in the lengthwise and widthwise direction of the sheet (11) and is secured to the inner side of the spine (2) with said plastic sheet. A filing device as claimed in claim 6, wherein the plastic sheet (11) carrying the polyurethane elastomer (13) is secured to the inner side of the spine (2) with the polyurethane elastomer (13) affixed to the back side of the plastic sheet (11) and the inner side of the plastic spine (2) is coated with metal foil (15), pigment foil or silk printing ink or is surface-treated using photogravure or offset lithography. A filing device as claimed in claim 7, wherein the plastic sheet (11) is transparent or semi-transparent. A filing device as claimed in claim 1, wherein a polyurethane elastomer sheet (19) having innumerable protrusions (20) in the lengthwise and widthwise direction is secured to the inner side of the spine (2). A filing device as claimed in claim 9, wherein the inner side of the spine (2) is coated with metal foil (21), pigment foil or silk printing ink or surface-treated using photogravure or offset lithography. A filing device as claimed in claim 1, wherein such sheet-like materials (16) as document pouches and photo-mounting sheets coated with metal foil (17), pigment foil or silk printing ink or surface-treated using photogravure or offset lithography at the edge thereof are secured to the polyurethane elastomer (13) on the spine (2) in advance. Supplemental sheet-like materials (16) such as document pouches and photo-mounting sheets to be used in the filing device claimed in any of the above claims, wherein the edge of said material (16) is coated with metal foil (17), pigment foil or silk printing ink or is surface-treated using photogravure or offset lithography.

Inventors: NISHIKAWA KENJIRO, NISHIKAWA, KENJIRO, NISHIKAWA, Kenjiro, c/o MARUNI KASEI K.K.
Applicants: MARUNI KASEI KK, MARUNI KASEI KABUSHIKIGAISHA
Application year: 1991
Main classification: B42F7
IPC codes: B42D3, B42D1, B42F7, B42F21