Peeling glue and its manufacturing method

Abstract

To provide a peeling glue which, when peeling paper from a bound article, peels off together with the paper without leaving any glue fixing the peeled paper on the spine, and which can be stably glued without requiring the skill of an operator, and a method for manufacturing the same. The peeling adhesive of the present invention contains a thermoplastic resin and a wax, and the wax content is 55% by weight or more relative to the total weight. The thermoplastic resin is an ethylene-vinyl acetate copolymer. The wax is paraffin wax.

Description

[Technical Field]

[0001] The present invention relates to a peeling adhesive and a method for producing the same. [Background technology]

[0002] Top glue is a binding method widely used for binding booklets, forms, memo pads, etc. Top glue uses a water-based adhesive or hot melt adhesive (see Patent Documents 1 and 2) to glue and fix only the top edge (top) of a stack of paper.

[0003] Known water-based adhesives include funori and vinyl acetate resins, which are dispersed in a solvent such as water or alcohol and applied with a brush to the top (spine) of a vertically stacked stack of paper.

[0004] Hot melt adhesives are primarily made of thermoplastic resin and have the property of melting when heated and solidifying when cooled. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 58-27764 [Patent Document 1] Special Publication No. 2019-521219 Summary of the Invention [Problem to be solved by the invention]

[0006] Hot melt adhesives are highly viscous, so when used in applications where the paper needs to be peeled off one by one, the paper comes off and the glue remains as a lump on the spine, which creates an unsightly appearance.

[0007] Given this background, it is common practice in the printing industry to use water-based adhesives for pad binding, which involves peeling off each sheet of paper at a time.

[0008] However, bookbinding using a water-based adhesive has the problem that the bookbinding process takes time and requires the operator to be highly skilled.

[0009] The concentration of water-based adhesive changes over time as the solvent evaporates. Therefore, it is necessary to adjust the concentration by adding solvent. If this adjustment is neglected, the quality of the binding will be unstable. The concentration is checked by the operator by controlling the time it takes for the water-based adhesive to flow out of the funnel, but this control is difficult. Furthermore, applying glue with a brush is difficult to do thinly, and can only be done by hand by an experienced operator.

[0010] When using water-based adhesives in a machine, it is necessary to carefully adjust the amount of adhesive, adjust the drum height, and use mechanical know-how, as well as to carefully adjust the adhesive mixture. Furthermore, after each use, the water-based adhesive must be drained from the adhesive tank and time-consuming cleaning is required. Furthermore, the water-based adhesive splatters around, which also requires cleaning.

[0011] The present invention has been made in view of the above problems, and aims to provide a peel-off adhesive that, when paper is peeled off from a bound product, peels off together with the paper without leaving any glue that has fixed the peeled paper on the spine, and that can be stably glued without requiring the skill of an operator, and a method for manufacturing the same. [Means for solving the problem]

[0012] A first aspect of the present invention is A binding adhesive that is applied to the spine of a book and allows the paper to be peeled off one by one, and is 17% by weight or more and 20% by weight or less of the total weight. A thermoplastic resin, 55% by weight or more Wax and 21% by weight or more and 26% by weight or less of a tackifier; Including For bookbinding Provide peel adhesive.

[0013] Contains thermoplastic resins that melt when heated and solidify when cooled For bookbinding Because peel-off glue does not contain solvents, there is no need to adjust the concentration, and it can be applied mechanically. This allows for stable gluing without requiring operator skill, improving productivity. Furthermore, compared to binding using water-based adhesives, it also reduces the time required for drying the glue and cleaning the equipment.

[0014] By blending more than 55% wax by weight, adhesiveness is weakened and peeling is excellent. For bookbinding It becomes a peeling adhesive.

[0015] According to the second aspect of the present invention For bookbinding In the peeling adhesive according to the first aspect, the thermoplastic resin is an ethylene vinyl acetate copolymer.

[0016] According to the third aspect of the present invention For bookbinding In the peeling adhesive of the first or second embodiment, the wax is paraffin wax.

[0017] The present invention 1 According to the aspect of For bookbinding In the peeling adhesive, the content of the wax relative to the total weight is 60% by weight or less.

[0018] If the wax content is 60% or less, the bound paper will not come apart and the quality of the binding will be maintained.

[0019] A fourth aspect of the present invention is A method for manufacturing a binding peeling glue that is applied to the spine of a book and used by peeling off the paper one by one, with respect to the total weight: Thermoplastic resin 17% by weight or more and 20% by weight or less , wax The thermoplastic resin, the wax and the tackifier are mixed so that the content of the thermoplastic resin is 55% by weight or more and 60% by weight or less, and the content of the tackifier is 21% by weight or more and 26% by weight or less. The method includes the step of blending For bookbinding To provide a method for producing a peeling adhesive. [Effects of the Invention]

[0020] According to the present invention, when the paper is peeled off, the glue that has fixed the peeled paper does not remain on the spine but peels off together with the paper, and the peeling glue can be used stably without requiring the skill of an operator. [Brief explanation of the drawings]

[0021] [Figure 1] This is an illustration of what would happen if no glue remained on the spine of the bound book during the peel test. [Figure 2] This is an illustration of what happens when glue remains on the spine of a bound book during a peel test. [Figure 3] FIG. 1 is an image diagram showing the procedure of a drop test. DETAILED DESCRIPTION OF THE INVENTION

[0022] (Removal glue) The peel glue comprises a thermoplastic resin, a wax, and a tackifier.

[0023] The content of the thermoplastic resin in the peeling adhesive is 17% by weight or more and 20% by weight or less, and preferably 18% by weight or more and 19% by weight or less.

[0024] The wax content in the peeling adhesive is 55% by weight or more, preferably 56% by weight or more and 60% by weight or less.

[0025] The amount of tackifier in the peeling adhesive is 21% by weight or more and 26% by weight or less, and preferably 23% by weight or more and 25% by weight or less.

[0026] The viscosity (melt viscosity) of the peeling adhesive at 120°C is 100 mPa·s or more and 500 mPa·s or less, preferably 120 mPa·s or more and 420 mPa·s or less.

[0027] (Ingredients of peeling adhesive) The thermoplastic resin may be a polyester, a polyamide, an ethylene-vinyl acetate copolymer, a styrene block copolymer, or the like. The thermoplastic resin is preferably an ethylene-vinyl acetate copolymer. The ethylene-vinyl acetate copolymer is a synthetic resin produced by copolymerizing ethylene and vinyl acetate. The vinyl acetate content of the ethylene-vinyl acetate copolymer may be 25% by weight to 40% by weight.

[0028] Wax is a component that adjusts the melting point of the peel adhesive, reduces the melt viscosity, and provides fluidity. The wax may be natural or synthetic. Natural waxes include paraffin wax and microcrystalline wax. Synthetic waxes include Fischer-Tropsch wax, polyethylene wax, and polypropylene wax. These may be used alone or in combination.

[0029] The tackifier is a component for improving the adhesive strength and wettability of the peel adhesive. The tackifier may be a petroleum-based hydrocarbon resin or a natural resin. Petroleum-based hydrocarbon resins include aliphatic hydrocarbon resins, aromatic hydrocarbon resins, alicyclic hydrocarbon resins, and hydrogenated and modified versions thereof. Natural resins include terpene resins, terpene phenol resins, and rosin-based resins. These may be used alone or in combination of two or more.

[0030] The peeling adhesive may contain additives such as stabilizers, pigments, plasticizers, inorganic fillers, etc., as needed, within the scope of not impairing the object of the present invention.

[0031] (Method for manufacturing peeling glue) The peel adhesive of this embodiment is obtained by placing the measured components in a container, heating them at the melting temperature of the thermoplastic resin, stirring, and then cooling and solidifying the uniformly mixed mixture.

[0032] In the production of the peeling paste according to this embodiment, the wax is blended so that the wax content relative to the total weight of the peeling paste is 55% by weight or more, preferably 56% by weight or more and 60% by weight or less.

[0033] A commercially available hot melt adhesive may be used as the thermoplastic resin. In this case, the amount of wax to be added can be determined by taking into account the amount of wax contained in the commercially available hot melt adhesive.

[0034] The following describes the effects of the peeling adhesive according to this embodiment. The peel adhesive of this embodiment contains 55% or more by weight of wax, making it less sticky than conventional hot melt adhesives available on the market. This means that when the paper is peeled off one by one from the bound product, the adhesive peels off along with the paper, leaving no residue behind on the bound product.

[0035] If the wax content is 60% by weight or less, the bound paper will not come apart and the quality of the binding can be maintained.

[0036] The peel adhesive according to this embodiment contains a thermoplastic resin, so it can melt when heated and solidify when cooled. Because this peel adhesive does not contain a solvent like a water-based adhesive, there is no need to adjust the concentration or wait for the solvent to evaporate, and stable gluing is possible without requiring the operator's skill.

[0037] This peel-off adhesive can be used in general-purpose perfect binders, etc. Conventional top-glue binding using water-based adhesives can only be done manually by an operator, but by using the peel-off adhesive of this embodiment, it is possible to mechanize the production of bound books in which the pages can be peeled off one by one, thereby improving productivity.

[0038] Furthermore, with pad binding using the peel-off adhesive according to this embodiment instead of a water-based adhesive, daily cleaning of the manufacturing equipment is also easy.

[0039] By applying top glue to bundled signatures using the peeling glue according to this embodiment, it is possible to separate the signatures into separate volumes without using a paper knife.

[0040] The peel adhesive according to this embodiment is suitable for use in the pad binding of booklets, memo pads, report forms, slips, receipts, study textbooks, letter paper, and short notes.

[0041] [Example] (Glue manufacturing) An ethylene vinyl acetate copolymer hot melt adhesive (HM-401, manufactured by Horizon Co., Ltd.) and Paraffin Wax-140 (manufactured by Nippon Seiro Co., Ltd., melting point 61°C) were placed in a beaker, melted in an oven at 120°C, and mixed.

[0042] The hot melt adhesive contains ethylene vinyl acetate copolymer, tackifier, paraffin wax, and additives. Paraffin Wax-140 (additional paraffin wax) was added to the adhesive so that the total weight of the paraffin wax (total paraffin wax) was the amount shown in Table 1.

[0043] The viscosity (mPa·s) of the obtained paste at 120°C was measured using a Brookfield viscometer.

[0044] (Bookbinding) Using the adhesive prepared above, books were bound under the following conditions (Test Examples 1 to 6).

[0045] Paper: Copy paper (CF-C081, Canon) Bookbinding machine: Perfect binder (BQ-500, manufactured by Horizon Co., Ltd.) Binding size: 60mm x 100mm x 10mm thick (glue applied to the 60mm side) Grain: parallel to the spine Glue application temperature: 120°C (180°C in some test cases)

[0046] As comparative examples, bookbinding was also carried out using an aqueous adhesive (Sakuranoru, manufactured by Ishizuka Sangyo Co., Ltd.), hot melt adhesive 1 (manufactured by Horizon Co., Ltd.), and hot melt adhesive 2 (for top glue, manufactured by Horizon Co., Ltd.) instead of the peeling adhesive produced above. Bookbinding using hot melt adhesives 1 and 2 was carried out in the same manner as in Test Examples 1 to 6.

[0047] The water-based adhesive used was an emulsion solution of vinyl acetate resin dispersed in ethanol and water. In bookbinding using water-based adhesive, the operator applied glue with a brush to the spine of a neatly stacked stack of paper while controlling the concentration of the water-based adhesive. The glued area was then dried with a dryer.

[0048] (peel test) For each bound product, each sheet of paper in the stack was peeled off by hand. After peeling off several sheets, it was visually confirmed whether only a film of glue remained on the spine of the bound product where the paper had been peeled off. If the glue had torn off along with the peeled paper, glue 11 would be on the peeled paper 10 side, as shown in Figure 1, and no glue would remain on the peeled part of the spine 13 of bound product 12. If only the paper had peeled off, glue 11 would remain on the spine 13 of bound product 12 where the paper 10 had been peeled off, as shown in Figure 2. In Table 1, if no glue remained on the spine of the bound product, it was marked with a circle, and if it did, it was marked with an X.

[0049] (Drop test) As shown in Figure 3, each bound product 12 was allowed to drop from a height of 140 mm to check whether the bound paper would come apart. In Table 1, the product was tested multiple times and those that did not come apart even after being dropped several times were marked with a 〇, those that came apart after being dropped two or three times were marked with a △, and those that came apart after being dropped just once were marked with an ×.

[0050] (Productivity evaluation) In Table 1, productivity is indicated as "O" when it is judged to be high, and as "X" when it is judged to be low.

[0051] (result) Table 1 shows the adhesive formulation, viscosity (mPa·s, 120° C.), peel test, drop test and productivity evaluation results for Test Examples 1 to 6 and each Comparative Example.

[0052] [Table 1]

[0053] The viscosities of Hot Melt Adhesive 1 and Test Example 1 at 120°C were high, at 10,900 mPa·s and 5,762 mPa·s, respectively. Therefore, both were bound at 180°C. Test Examples 2 to 5 all had a viscosity of 1,000 mPa·s or less at 120°C, and could be applied to the spine of the paper stack without any problems. The viscosity of Test Example 6 at 120°C was impossible to measure.

[0054] According to Table 1, in the bound products of Test Examples 3 to 6, in which the aqueous adhesive and total paraffin wax content was 55% by weight or more, after the paper was peeled off one by one, no glue remained on the bound product, and the glue was peeled off along with the peeled paper.

[0055] On the other hand, in the case of the bound books made with hot melt adhesives 1 and 2 and test examples 1 and 2, in which the total paraffin wax content was 52% by weight or less, it was not possible to peel off a single sheet of paper with a moderate amount of force, or only the paper peeled off, with the adhesive remaining on the spine of the bound book.

[0056] These results suggest that for glue that does not contain solvents such as water or ethanol, the amount of wax can be made to exceed 52% by weight, preferably 55% by weight or more, and more preferably 56% by weight or more, relative to 100% by weight of glue, so that the glue can be peeled off along with the paper.

[0057] According to Table 1, the bound products of each comparative example and test examples 1 to 3 were subjected to multiple drop tests and the bundle did not come apart even after being dropped multiple times. In test example 4, the bundle came apart after being dropped two or three times. In test examples 5 and 6, the bundle came apart after being dropped just once.

[0058] These results confirmed that the quality of the bound product can be ensured by keeping the amount of wax to 62% by weight or less, preferably 60% by weight or less, relative to 100% by weight of glue.

[0059] Bookbinding using water-based adhesives is performed manually by an operator, resulting in lower productivity than the other comparative examples and test examples 1 to 6, which use a perfect binder. It is difficult to control the concentration of water-based adhesives, and it takes time for the glue to dry.

[0060] On the other hand, with the hot melt adhesives 1 and 2 and Test Examples 1 to 6, gluing was achieved by melting and solidifying, so that bookbinding could be completed in a shorter time than with water-based adhesives without the need for concentration control.

[0061] 10 Paper 11 Glue 12 Bound items 13 (Book) spine

Claims

1. A bookbinding peeling adhesive that is applied to the spine of a bound book and allows the pages to be peeled off one by one, The bookbinding peel adhesive contains, relative to the total weight, 17% by weight or more and 20% by weight or less of a thermoplastic resin, 55% by weight or more and 60% by weight or less of a wax, and 21% by weight or more and 26% by weight or less of a tackifier.

2. 2. The bookbinding peeling adhesive according to claim 1, wherein the thermoplastic resin is an ethylene-vinyl acetate copolymer.

3. 2. The bookbinding adhesive according to claim 1, wherein the wax is paraffin wax.

4. A method for manufacturing a peel-off adhesive for bookbinding, which is applied to the spine of a bookbinding material and is used by peeling off the paper one by one, comprising: A method for producing a bookbinding peel glue, comprising a step of blending a thermoplastic resin, a wax, and a tackifier so that the total weight of the thermoplastic resin is 17% by weight or more and 20% by weight or less, the wax is 55% by weight or more and 60% by weight or less, and the tackifier is 21% by weight or more and 26% by weight or less.

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