JPH03253396A - Book-binding cover - Google Patents

Abstract

PURPOSE:To improve the durability of a cover and to enable a sure bookbinding in a short time by causing the title cover to have mutually connected front cover, reverse cover, and back sheet and a hot-melt type adhesive layer applied to the back sheet and by forming the adhesive layer into a multilayered structure and lowering the softening points of respective layers constituting the adhesive layer as they are distant from the back sheet. CONSTITUTION:The title cover has a front cover 1, reverse cover 2 and back sheet 3, which are mutually connected at ends, and an adhesive layer 4 applied to the back sheet 3. The front cover 1 and reverse cover 2 are respectively provided in the manner of being rotatable at connections 10, 11 relative to the back sheet 3. Such front cover 1, reverse cover 2 and back sheet 3 are formed when e.g. a sheet of thick paper is folded at the parts corresponding to the connections 10, 11. The adhesive layer 4 is constituted by lamination of a plurality of adhesive layers of different softening points. The softening points of respective adhesive layers constituting the adhesive layer 4 successively lower from the back sheet 3 side. For example, the adhesive layer 4 has the two-layer structure of a first adhesive layer 4a (sublayer) adhering to the inner surface of the back sheet 3 and a second adhesive layer 4b (top layer) to be adhering applied to the surface of the first layer and the second adhesive layer 4b has the softening point lower than that of the first adhesive layer 4a. As a result, the part of the adhesive layer 4 near the back sheet 3 is high in mechanical strength.

Description

[Detailed description of the invention]

[00013

[Industrial Application Field] The present invention relates to a bookbinding cover with adhesive used when documents produced by printing or copying are simply bound in an office or home. [0002] [Prior Art] This type of bookbinding cover is known, for example, from the Japanese Patent Publication Publication No. 61-4
In Publication No. 675, an adhesive layer is provided on the board, and an adhesive is provided on the inner surfaces of the front and back covers near the board to regulate the position of the pieces of paper to be bound and to provide reinforcing adhesive. There's something I'm trying to do. [0003] In addition, Japanese Utility Model Application Publication No. 59-17746 describes the structure of a resin sheet for bookbinding, in which a nonwoven fabric, paper, woven fabric, etc. is used as a base material, and this is impregnated with a so-called hot melt adhesive. , discloses a technology that aims to increase the strength and durability of the bookbinding part by providing an adhesive layer on the front and back sides and using such a sheet as an adhesive sheet for bookbinding. [0004] Further, in Japanese Utility Model Application Publication No. 61-50469, a capsule containing a liquid adhesive is provided on a tape-shaped base paper, and the capsule is destroyed by heat and pressure during bookbinding, thereby adhering the paper that becomes the page. It shows what you are trying to do. [0005] Furthermore, in Japanese Utility Model Application Publication No. 61-180752, cut grooves are provided in the longitudinal direction in the hot melt adhesive layer provided on the inner surface of the board, and adhesive bonding is performed in accordance with the amount (thickness) of paper to be bound. The design is such that the parts can be bent. [0006] Further, JP-A-48-53821 also discloses a cover with adhesive. [0007]

[Problem to be solved by the invention]

In these conventional examples, the arrangement, shape, etc. of the adhesive layer are described, but the adhesive performance of the adhesive is not described in any of them. [0008] In general, the adhesive layer of the plate portion undergoes repeated bending movements when the book is opened and closed, and requires considerable strength. [0009] On the other hand, from the point of view of ease and speed of adhesion, hot melt adhesives are effective, and it is advantageous that the softening temperature thereof is moderately low. In other words, hot-melt adhesives are suitable for simple bookbinding because they complete adhesion by melting by heating and solidifying by cooling.Furthermore, the lower the softening temperature, the less heat energy is required, so it is relatively easy to use. Since it softens at a low heating temperature, a short heating time is required to bring it into a bondable state. Moreover, the time required for cooling and solidifying to complete the adhesion is relatively short, which is another advantageous property. [00101 However, as a means to lower the softening temperature of hot melt adhesives, methods such as mixing components with a small molecular weight that reduce the molecular weight of the material are adopted, but these methods all affect the mechanical strength of the adhesive layer. This results in a decrease in the flexural strength of the plate, which is contrary to the requirements of this application, where the bending strength of the bonded portion of the plate is important. [0011] The present invention was made in view of the above-mentioned circumstances, and an object of the present invention is to provide a cover for bookbinding that has excellent durability and can be bound reliably in a short time. [0012]

[Means to solve the problem]

The bookbinding cover of the present invention has a front cover, a back cover, and a back plate that are connected to each other, and a heat-melting adhesive layer applied to the back plate, and the adhesive layer has a multilayer structure. It is characterized in that the softening point of each layer constituting the back plate decreases as the distance from the back plate increases. [0013] According to the present invention, it is possible to perform bookbinding with sufficient mechanical strength even with short-time heating. [0014] The present invention will be described below with reference to the drawings. [0015] As shown in FIG. 1, the bookbinding cover of the present invention includes a front cover 1, a back cover 2, and a back plate 3 that are connected to each other at their ends, and an adhesive layer 4 applied to the back plate 3. . Front cover 1 and back cover 2
are each rotatably provided with respect to the back plate 3 at connecting portions 10.11. The front cover 1, back cover 2, and back plate 3 are formed by, for example, folding two sheets of cardboard at the portions corresponding to the connecting portions 10.11. [0016] The adhesive layer 4 is made of a hot melt adhesive and is applied to the inner surface of the back plate 3 (the surface on which the pieces of paper that will become the pages of the book are placed). [0017] To bind a book using the bookbinding cover of the present invention,
As shown in FIG. 2, the adhesive layer 4 is heated and softened by heating from the front side of the back plate 3 for a predetermined period of time while pressing the end face of the paper strip bundle 6, in which the paper strips 6a forming each page of the book are stacked, against the adhesive layer 4. [0018] After heating, as the adhesive layer 4 cools, each piece of paper 6a is firmly adhered to the adhesive layer 4, and one book is produced. [0019] In the present invention, the adhesive layer 4 is constructed by laminating a plurality of adhesive layers having different softening points. The softening point of each adhesive layer constituting the adhesive layer 4 becomes lower in order from the back plate 3 side. In FIG. 1, the adhesive layer 4 is a first adhesive layer 4a that adheres to the inner surface of the back plate 3.
[0020] As described above, in the bookbinding cover of the present invention, the adhesive layer 4 has a plurality of layers. The adhesive layer 4 is constructed by laminating adhesive layers, and the portion of the adhesive layer 4 near the back plate 3 has a high softening point. For this reason, the adhesive layer 4
The portion near the back plate 3 has high mechanical strength, and even if the front cover 1 or the back cover 2 is repeatedly opened and closed, the piece of paper 6a will not fall off from the adhesive layer 4. [0021] On the other hand, since the portion of the adhesive layer 4 far from the back plate 3 has a low softening point, the adhesive layer is softened in a short time by heating at a relatively low temperature, and the paper strip bundle 6 can be quickly and reliably bonded with low energy. Adhesive layer 4
Can be glued to. In other words, the adhesive layer 4 in the present invention improves durability in the portion close to the back plate 3, and
The bundle of paper strips 6 is quickly and reliably bonded to the adhesive layer 4 with low energy at a portion far from the paper strips. The layer close to the surface of the adhesive layer 4 only needs to have sufficient strength to hold and fix the bundle of paper strips 6, and has the mechanical strength required after bookbinding.
It is not necessary to have characteristics such as flexibility. For this reason, when bonding, only this relatively thin layer (the thickness of the adhesive layer will be discussed later), which has a small heat capacity near the surface, needs to be softened, and coupled with its low softening point,
The thermal energy required for adhesion is small, and heating only takes a short time. Therefore, according to the bookbinding cover of the present invention, as already mentioned above, the time required for cooling and solidifying can be shortened, and the overall time required for solidification is extremely short.
Bookbinding becomes possible with energy savings. [0022] As shown in FIG. 1, in a bookbinding cover in which the adhesive layer 4 has a two-layer structure, the first adhesive layer 4a has a relatively high softening point and has sufficient strength to withstand mechanical destruction. The second adhesive layer 4b has a relatively low softening point and is thermally melted at a relatively low temperature for a relatively short period of time during adhesion to moderately wet the end surface of the paper strip bundle 6 and then undergo the next cooling process. This is to ensure complete adhesion without failure. [0023] The softening point of the adhesive layer 4 is 100' at the highest softening point.
C or higher is preferable. Practically 100°C to 200'C1
More preferably, the temperature is 120'C to 180C. Among the adhesive layers constituting the adhesive layer 4, the layer with a high softening point, that is, the adhesive layer close to the back plate 3, basically does not need to be thermally melted during bookbinding, so it mainly has a mechanical strength that can withstand practical use. The type, composition, and thickness of the material may be selected depending on whether flexibility can be obtained. [0024] Among the adhesive layers constituting the adhesive layer 4, the layer with a low softening point, that is, the adhesive layer far from the back plate 3, is better if the softening point is lower, considering the thermal energy during bookbinding. The softening point must be determined not only by thermal efficiency during bookbinding, but also by taking into full consideration the state of penetration of the adhesive layer into the paper pieces, mechanical strength, etc. That is, when attempting to lower the softening point of the adhesive layer, a material with a low molecular weight is used or a large amount of a material with a low molecular weight is contained in the adhesive layer. Therefore, an adhesive layer with a low softening point is likely to penetrate into the bundle of paper strips to be bonded, and if the penetration is severe enough, the adhesive layer that has penetrated may become stained. In addition, the adhesive force of an adhesive layer with a low molecular weight generally tends to be low, and this point also needs to be taken into consideration to ensure that it is sufficiently practical. Considering these, 50°C to 90'C1 at the lowest softening point part.
Furthermore, 60°C to 80'C is preferable. [0025] In the present invention, the softening point is determined according to the Japan Adhesive Industry Association standard "
This is a value measured according to the environmental law softening point measurement method specified in Hot Melt Adhesive Test Method JAI 7-198. [0026] The total thickness of the adhesive layer 4 is preferably 0.5 to 3.0 mm, more preferably 0.6 to 2.5 mm. The thickness of each adhesive layer constituting the adhesive layer 4 is 0.1 to 2.0 mm, more preferably 0.3 to 2.0 mm.
1.5 mm is preferred. Paper piece 6 without considering mechanical strength
If only a is bonded, the thickness of the adhesive layer can be made extremely thin. In other words, the thickness of the portion of the adhesive layer 4 (adhesive layer with a low softening point) where the ability to properly adhere the paper pieces 6a is required to be stronger than the mechanical strength can be made thinner. Therefore, the thickness of each adhesive layer constituting the adhesive layer 4 can be gradually reduced as the distance from the back plate 3 increases. If the adhesive layer 4 has a two-layer structure as shown in FIG.
The adhesive layer only needs to have a thickness that allows it to uniformly and sufficiently wet the end face of the bundle of paper strips to be bonded, and to maintain adhesion with the first adhesive layer while holding the bundle of paper strips after cooling. [0027] When forming the adhesive layer 4, a conventionally known hot melt adhesive can be used for each adhesive layer. That is, a hot melt resin having a desired softening point or a mixture of a hot melt resin with rosin, rosin inductive properties, and various plasticizers for the purpose of imparting tackiness or adjusting the softening point can be used as the adhesive layer. . Furthermore, for the purpose of adjusting viscosity or fluidity, a mixture of various waxes with a hot-melt resin or the above-mentioned mixture can be used as the adhesive layer. Further, in order to impart mechanical strength to the adhesive layer, an inorganic filler such as clay, talc, etc. may be appropriately contained in the adhesive layer. Further, the adhesive layer may contain an antioxidant and various pigments as required. [0028] As the above-mentioned hot-melt resin, one or more of, for example, ethylene-vinyl acetate copolymer, polyamide resin, polyolefin resin, polyester resin, etc. can be used. [0029] Examples of the above-mentioned waxes include vegetable waxes such as carnauba wax, candelilla wax, rice wax, and Japanese wax, and mineral waxes such as ceresine wax and montan wax. [0030] [0031] One or more types of polyethylene wax, Fischer-Tropsch wax, etc. can be used. [0032] The compounding ratio of the materials constituting the adhesive layer 4 is not particularly limited as long as a desired softening point can be obtained, but to give an example of a preferable compounding ratio, for example, each adhesive layer constituting the adhesive layer 4 30 to 70% by weight of hot-melt resin, 10 to 50% by weight of rosin, rosin derivatives or various plasticizers, 15 to 20% by weight of various waxes, and further antioxidants, fillers, and various other substances as necessary. It is preferable to contain a pigment or the like. [0033] The softening point of the adhesive layer is highly related to the molecular weight of the material used. That is, when the molecular weight is small, the softening temperature is low, and conversely, when the molecular weight is large, the softening point is high. Therefore, the softening point can be easily adjusted by adjusting the molecular weight of the material used. [0034] The adhesive layer 4 is preferably formed by applying a desired hot-melt adhesive to the inner surface of the back plate 3 using a coating means such as an applicator. [0035] That is, first, the first adhesive layer is applied using a coating machine that has a part that heats and melts the hot-melt adhesive and a part such as a nozzle or roller that applies the hot-melt adhesive to the inner surface of the back plate. death,
Once the first adhesive layer has solidified, apply a second adhesive layer thereon, and if there is a third adhesive layer, fourth adhesive layer, etc., repeat the above application for the number of adhesive layers, then apply the entire All you have to do is cool it down. [0036] In order to adhere the bundle of paper strips 6 to the bookbinding cover of the present invention thus created, as described above with reference to FIG.
A stack of paper strips 6 is inserted vertically into the adhesive layer, and while pressing the aligned edges of the paper onto the adhesive layer 4, the back plate is heated to a temperature of 120 to 130, for example, by heating means (for example, a hot plate).
Bookbinding can be carried out very easily by heating the sheet at C for about 20 to 40 seconds (the heating temperature and heating time are adjusted depending on the thickness of the back plate, etc.) and then leaving it to cool. There are currently many bookbinding machines on the market that can perform bookbinding by heating the back plate of the cover for bookbinding in this manner. [0037] The present invention exhibits excellent effects regardless of the type of paper strips 6a that will become the pages of a book, but it depends on how much the melted adhesive layer soaks into the paper strips 6a, or the difference between the paper strips 6a and the paper strips 6a. Depending on how much the melted adhesive layer gets in between, etc.
It is also true that the adhesiveness between the adhesive layer 4 and the paper strip 6a is somewhat dependent. Furthermore, if the melted adhesive layer soaks into the paper strips 6a more than necessary, or if it penetrates deeply between the paper strips 6a, the melted adhesive layer will stain, which is not practical. That is, in order to further improve the present invention, it is preferable to consider the physical properties of the paper strip 6a, especially the density and smoothness of the paper strip 6a. That is, the paper strip used for the bookbinding cover of the present invention preferably has a density of 0.750±0.150 g/cmS. In addition, the smoothness of the paper strip is 10 seconds to 100 seconds,
Furthermore, 15 seconds to 80 seconds is preferable. [0038] The present invention will be further explained below with reference to Examples. [0039]

[Example 1-5] In Fig. 1, the first layer 4 is ethylene vinyl acetate hot melt adhesive Bond BC603 (softening point 109°C) manufactured by Konishi Co., Ltd., and the second layer 5 is Asahi Kagakusei Co., Ltd. 2982 (softening point 81°C) was applied to ethylene vinyl acetate hot melt adhesive (softening point: 81°C) to a thickness of 1.0 mm and 0.5 mm, respectively, using a Nordson applicator to a thickness of 0.8 mm.
(a front cover, a back cover, and a back plate are connected to form one sheet) was coated on the back plate part of the paper (a front cover, a back cover, and a back plate are connected to form a single sheet) to create a bookbinding cover of the present invention for an A4 size book. [00403] A book was bound by adhering a stack of 50 sheets of paper shown in Table 1 to the adhesive layer of this cover for bookbinding. To bond the bundle of paper strips, place the bundle of paper strips on the adhesive layer and set the surface temperature to 130°.
The back plate was placed on the hot plate C for 20 seconds.・[0041] As a result, the bundle of paper sheets adhered to the adhesive layer with sufficient strength approximately 25 seconds after heating was completed, and the pages did not separate from the adhesive layer even when the pages were stretched by hand. Beige is torn) can now be handled. [0042]

[Outside]

No. table [0043]

[Example 6-101 The first layer 4 in FIG.
Softening point: 120'C) For the second layer, 0.7 mm and 0.3 mm of 2982 were added to the same adhesive as in Example 1, respectively.
With a thickness of A cover for bookbinding according to the present invention was prepared. [0044] Bookbinding was carried out by adhering a stack of 50 sheets of paper shown in Table 2 to the adhesive layer of this cover for bookbinding. To bond the bundle of paper strips, place the bundle of paper strips on the adhesive layer and set the surface temperature to 130'.
The back plate was placed on the hot plate C for 30 seconds. [0045] As a result, the bundle of paper strips adhered to the adhesive layer with sufficient strength in about 30 seconds after the completion of heating, and became handleable. [0046] [Table] Table [0047]

[Example 11] A three-layer adhesive layer was formed on the back plate of a 0.8 mm thick paper (front cover, back cover, and back plate are connected to form a single sheet), and an A4 size paper was formed. A cover for bookbinding of the present invention to be used as a book was prepared. The adhesive layer of the three-layer structure was prepared from the back plate side by adding 2982 to the adhesive used in Example 6, PES-120H, the hot melt adhesive bond BC603 used in Example 1, and 0 to 0 to the adhesive used in Example 1. .7mm, 0.5mm
and 0.3 mm thick were sequentially coated and formed. [0048] Bookbinding was carried out by adhering a stack of 50 sheets of the same paper as in Example 1 to the adhesive layer of this cover for bookbinding. The paper strip bundles were bonded in the same manner as in Example 1. [0049] As a result, the bundle of paper strips adhered to the adhesive layer with sufficient strength in about 25 seconds after the end of heating, and became handleable. [00501 [Comparative Example] The same hot melt adhesive bond BC603 as in Example 1 was applied to the back plate part of a 0.8 mm thick paper (front cover, back cover and back plate connected to form one sheet). It was applied to a thickness of 1.5 mm using an applicator to prepare a bookbinding cover for an A4 size book. [0051] A bundle of 50 sheets of the same paper as in Example 1 was adhered to the adhesive layer of this cover for bookbinding, thereby binding a book. The paper strip bundles were bonded in the same manner as in Example 1. [0052] As a result, it took about 45 seconds until the product could be handled after heating.

[Brief explanation of drawings]

[Figure 1] FIG. 1 is a plan view showing an example of a bookbinding cover of the present invention.

2 is a plan view showing a state in which a book is bound using the bookbinding cover shown in FIG. 1; FIG.

[Explanation of symbols]

3 Back plate 4 Adhesive layer 6. Bunch of paper strips

[Document color]

[Figure 1] drawing

[Figure 2] 6 〉

Claims (2)

[Claims] 1. A front cover, a back cover, and a back plate connected to each other, and a heat-melting adhesive layer applied to the back plate, the adhesive layer having a multilayer structure, and each layer constituting the adhesive layer. A cover for bookbinding, characterized in that the softening point of the cover decreases as the distance from the back plate increases. 2. The adhesive layer has a two-layer structure in which a first adhesive layer and a second adhesive layer are laminated in order from the back plate side.
cover for bookbinding.