JP4713991B2 - Back print label paper - Google Patents

Description

  The present invention relates to label paper used for price display, bar code display, or on-demand applications for displaying variable information each time, and in particular, printed characters or The present invention relates to a label paper in which a symbol, a figure, or a combination thereof (hereinafter referred to as a character or the like) is not rubbed after being stuck and becomes unclear or is rewritten for improper purposes.

  Conventionally, various labels, stickers, or sheets for preventing replacement have been proposed. For example, in Patent Document 1, as a re-sticking label, a surface base material, a cohesive failure layer that is formed on the back surface of the base material and cohesively breaks when the base material is peeled off, and a back surface of the destruction layer are formed. An anti-replacement label including an adhesive layer has been proposed. Patent Document 2 proposes a brittle adhesive sheet using a resin composition containing a polyurethane resin and an inorganic filler.

  However, in the anti-replacement label proposed in Patent Document 1, it is necessary to increase the filler component in the cohesive failure layer formed of only the filler and the resin in order to make the peel strength suitable. Therefore, there has been a problem that paper powder is generated on the surface layer of the cohesive failure layer. In addition, since the cohesive failure layer is solidified solidly with solid content, a large amount of raw material is used, which increases the cost.

  Moreover, since the brittle adhesive sheet proposed in Patent Document 2 uses a polyurethane resin as a raw material, there is a problem that it has difficulty in weather resistance depending on applications.

  Further, the anti-replacement label proposed in Patent Document 1 is assumed to be used as a price tag label, and a high-quality paper having a concealing property is used for the base material, and the price of the product is displayed on the surface, for example. Printing for printing, printing, etc. are performed. However, the display of the price printed by the surface of the substrate rubbing may become unclear, and the price display may be intentionally cut and the price may be rewritten.

  It is also conceivable to cover the surface of the printed substrate with a transparent plastic film so that the price display of the printed product is not rubbed or scraped, so-called laminating. However, covering the substrate surface with a plastic film after printing is troublesome and costly, and the label becomes thick.

In addition, conventional anti-replacement labels and brittle adhesive sheets such as those proposed in Patent Documents 1 and 2 cannot be reattached after peeling because the cohesive failure layer is destroyed at the time of peeling, preventing unauthorized use. However, if the substrate side on which the price of the product or the like is printed is removed after the peeling, there is a problem that the price of the product before the peeling becomes unknown.
JP-A-8-30202 JP 2003-171478 A

  The present invention, once pasted and peeled, can not be re-adhered, not only improper use is prevented, the printed characters and the like are not rubbed and become unclear or scraped, Furthermore, it is an object of the present invention to provide a new label sheet in which characters and the like printed on the adherend side remain identifiable even after peeling.

  The structure of the present invention made for the purpose of solving the above problems is that a cohesive fracture layer having a porous structure is provided on one surface of a transparent substrate, and characters are printed on the surface of the fracture layer. In the label paper provided with the pressure-sensitive adhesive layer, printed characters and the like are viewed from the other side of the substrate.

According to the present invention, in the above configuration, printing is preferably performed using an ink having a solvent as a main component of any of methyl ethyl ketone, toluene, ethyl acetate, or a mixture of two or more thereof. Also, by using this ink, the ink receiving portion on which the cohesive failure layer is printed is dissolved or swollen by the solvent of the ink, the porous structure is crushed and densified, and a transparency phenomenon can occur. It becomes. Furthermore, the surface layer peel strength of the cohesive failure layer at the time of adhesion of the adhesive layer to the adherend is preferably 0.10 to 1.50 N / 25 mm.

  In the present invention, since the cohesive failure layer has a porous structure, if the cohesive failure layer is provided on one surface of a transparent substrate, and characters are printed on the surface of the disruptive layer, the ink becomes the cohesive failure layer. Since it was made a back-print type label paper, paying attention to the fact that it was accepted and permeated to the boundary surface with the base material, and printed characters could be seen from the other side of the base material, laminating processing was done as before Even if it is not applied, characters such as the price of the printed product are protected by a transparent base material, and the effect that the characters do not become blurred even if the surface of the label paper is rubbed or soiled after sticking is obtained. Moreover, since it is protected by the transparent base material, the effect that there is no possibility that the price display of the product printed intentionally may be cut off is obtained.

  Further, when printing is performed on the label paper of the present invention, if the printing is performed using an ink whose main component is a solvent consisting of methyl ethyl ketone, toluene, ethyl acetate, or a mixture of two or more thereof, the above-mentioned destruction layer is printed. Since the ink receiving portion is dissolved or swollen by the ink solvent and the porous structure is crushed and densified, even if the destruction layer is destroyed and the substrate side is taken away, it remains on the product side Since traces such as printed characters can be read from a part of the destructive layer on the pressure-sensitive adhesive layer, it is possible to confirm what is displayed on the peeled label paper. It is done.

  Next, an embodiment of the present invention will be described with reference to the drawings. 1 is a cross-sectional view of an example of a back-printed label paper to which the present invention is applied, FIG. 2 is a plan view in which the peeling surface on the adhesive layer side after peeling of the label paper of FIG. 1 is enlarged, and FIG. FIG. 4 is a perspective view showing a state where a part of the label paper of FIG. 3 is peeled off, and FIG. 4 is a cross-sectional view of an example of the back print label paper of the present invention in which the print label paper is printed.

  FIG. 1 shows a structure in a state where printing is not performed in order to explain that the back print label paper of the present invention is basically an anti-paste label. In FIG. The base material 2 is a cohesive failure layer provided on one surface of the base material 1, and 3 is an adhesive layer provided on the surface of the cohesive failure layer 2.

  The substrate 1 used in the present invention can be basically used as long as it is a transparent film or sheet and can be coated. The thickness of the substrate 1 is 10 to 400 μm, preferably 20 to 300 μm. As a film-like thing, a transparent plastic film is mentioned, for example. Examples of the plastic film include transparent films such as polyethylene terephthalate, polypropylene, polystyrene, polyvinyl chloride, polymethyl methacrylate, polyethylene, polycarbonate, and polylactic acid. Among them, a film of polyethylene terephthalate or polypropylene is preferably used from the viewpoint of obtaining rigidity suitable for a label and cost. In order to improve the adhesion between the surface of the substrate 1 and the cohesive failure layer 2 that becomes the ink receiving layer, an easy adhesion treatment layer may be applied, or corona discharge machining may be applied. Furthermore, in order to increase the adhesive strength between the base material 1 and the cohesive failure layer 2, an anchor coat layer and an intermediate layer may be provided to increase cushioning properties.

  Next, the cohesive failure layer 2 is provided by applying a coating solution containing a resin and a filler, a coating solution containing only a resin, or a coating solution obtained by blending resins on one surface of the substrate 1. As the coating method, for example, a wet coagulation method can be used. Here, the wet coagulation method is a solution obtained by adding a filler to a resin dissolved in an organic solvent to form a coating liquid, and after applying the coating liquid on a substrate, it has compatibility with the solvent. An organic solvent is substituted and gelled by passing it through a liquid that is a non-solvent for the resin, solidified, and dried to form a cohesive failure layer that is a coating layer. Further, the remaining two types of coating liquids can be used. Furthermore, generally known dry coating methods can also be used. However, in order to form the cohesive failure layer, it is advantageous to use a wet coagulation method having a large porosity.

  The formed cohesive failure layer (coating layer) is formed in a porous structure, but the mechanism is that when the organic solvent is solidified by passing through a liquid that is a non-solvent for the resin, the organic solvent escapes into the liquid. This is because the escape passage becomes a cavity and the cavity becomes a hole. The number of times this solution is passed is usually 2 times. The temperature of the solution is 15 to 40 ° C., preferably 20 to 30 ° C., preferably 60 to 100 ° C. for the second time. Preferably they are 80 degreeC or more and 95 degrees C or less. By adjusting the temperature in this way, the number and size of the holes can be adjusted, and by increasing the temperature, the holes can be enlarged.

  The number and diameter of the holes in the cohesive failure layer 2 are the solid content weight concentration of the coating liquid forming the fracture layer 2, the ratio of the filler solid content weight / resin solid content weight in the fracture layer 2, and the temperature of the coagulation liquid. Since it can adjust by changing, it can be set as peel strength according to a use. Specifically, if the solid content weight concentration is low and the ratio of filler solid weight / resin solid content weight is high, the number of pores increases, and if the solid content weight concentration is low and the temperature of the coagulating liquid is high, the pore diameter is increased. can do. In the present invention, the peel strength can be controlled by adjusting the holes. Here, the peel strength generally refers to a force [N] applied when peeling, but particularly in the present invention, it refers to a force applied when the cohesive failure layer 2 is torn while being broken. This strength can be controlled by the degree of porosity. That is, by increasing the number of holes and increasing the hole diameter, it is possible to reduce the peel strength (to facilitate breakage between the cohesive failure layers). The surface peel strength at the time of adhesion of the cohesive failure layer 2 in the present invention is preferably 0.10 to 0.90 N / 25 mm, but the peel strength that best reproduces the effect of the present invention is 0.200 to 0.800 [N / 25 mm]. It is.

  As back print label paper, for example, a label attached to an over-the-counter product such as a price tag label, a thing attached to a bicycle wheel cover, a thing attached to a car engine room, a thing used for a breath ticket, variable information There are various types, such as those used for on-demand printing, but it is necessary to adjust the peel strength of the cohesive failure layer 2 to suit each of them depending on the adherend. In the present invention, it is possible to adjust the peel strength depending on the degree of porosity, and it is possible to produce one according to the degree of adhesion between the laminate and the adherend.

  As the resin of the coating liquid, polyester resin, polyvinyl chloride resin, polystyrene resin, polymethyl methacrylate resin, polycarbonate resin, polyurethane resin, vinyl chloride-vinyl acetate copolymer resin, acrylic resin, acrylonitrile-styrene copolymer resin, Acrylonitrile-methyl acrylate copolymer resin, polyvinyl butyral resin, styrene-butadiene copolymer resin, methyl methacrylate-butadiene copolymer resin, vinyl chloride-acrylic copolymer resin, vinyl acetate-ethylene-acrylic copolymer resin, and vinyl chloride- What mixed acrylic copolymer resin or vinyl chloride-vinyl acetate copolymer resin, and saturated copolymerization polyester resin etc. are mentioned.

  As the filler of the coating solution, either an organic filler or an inorganic filler can be used and is not particularly limited. For example, polystyrene, polymethyl methacrylate, styrene-acrylic copolymer, synthetic silica, clay, talc, diatomaceous earth, calcium carbonate, calcined kaolin, titanium oxide, zinc oxide, satin white and the like can be used. Of these, calcium carbonate and titanium oxide are preferably used. By using this, the printability and whiteness are improved at low cost.

  The organic solvent used in the coating solution may be any solvent that dissolves the resin that forms the porous layer. Examples thereof include dimethylformamide (DMF), N-methylpyrrolidone, dimethyl sulfoxide, dimethylacetamide, tetrahydrofuran, γ-butyrolactone, and the like. Among these, DMF is preferably used from the viewpoint of processability, simplicity, and low cost of the porous membrane.

  Next, examples of the liquid that is a non-solvent for the resin in the wet coagulation method include water, ethanol, methanol, and the like. Among these, water is preferably used. This is because water is very easy to handle.

The cohesive failure layer 2 produced in this way has a density of 0.5 to 1.0 g / cm ³ . When produced by the wet coagulation method, the cohesive failure layer 2 (porous layer) has a higher degree of porosity than the dry method, and it is possible to produce a laminate having an appropriate peel strength as an anti-sticking laminate. Therefore, it is not necessary to add a large amount of filler as in the dry method, and generation of paper dust can be prevented. Here, the density is a numerical value based on JIS P-8118.

  Moreover, 5-60 wt% is preferable and, as for the solid content weight concentration of the coating liquid which forms the cohesive failure layer 2, More preferably, it is 10-50 wt%. In order to produce a laminate having good peel strength for preventing re-sticking, the concentration needs to be in this range. When the concentration is lower than 5 wt%, the peel strength is lowered, and it may be difficult to apply as an anti-sticking application. On the other hand, when the concentration is higher than 60 wt%, the peel strength is increased, and the cohesive failure layer is less likely to cause cohesive failure, which may also be difficult to use as an anti-sticking application. On the other hand, if the concentration is out of the above range, the coatability (wetting with the substrate) is deteriorated, the surface is uneven, the product suitability is deteriorated, and this is not preferable.

  Furthermore, the filler to resin weight ratio in the solid content of the coating liquid forming the cohesive failure layer 2 is preferably 0.5 to 6.0 filler, more preferably 2.0 to 5.0 with respect to the resin 1. If the weight ratio is less than 0.5, it is difficult to form pores, resulting in an increase in peel strength and difficulty in cohesive failure. If it exceeds 6.0, the filler is exposed on the surface and causes paper dust, which is not preferable.

  In addition, the cohesive failure layer 2 is formed into a porous structure by the wet coagulation method, and the porous structure is an arithmetic average roughness of the peeled surface on the pressure-sensitive adhesive layer side of the cohesive failure layer 2 destroyed by peeling. Ra is in the range of 0.4 to 1.0 μm. This arithmetic average roughness Ra is related to the content of the porous material. By being in the above range, it can be said that the arithmetic average roughness Ra has appropriate pores as a cohesive failure layer when considered as a label for preventing replacement. Here, the arithmetic average roughness Ra is extracted from the roughness curve by a reference length in the direction of the average line, and the absolute values of deviations from the average line of the extracted portion to the measurement curve are summed and averaged. Say.

  Next, as the pressure-sensitive adhesive forming the pressure-sensitive adhesive layer 3, general resins such as natural rubber, synthetic rubber, acrylic and urethane can be used, and among them, acrylic resin is preferably used.

  The back print label paper to which the present invention of the above configuration is applied is used by applying the adhesive layer 3 to the adherend 4 and sticking it. In addition, release paper is pasted on the adhesive layer 3 in advance, and the release paper is peeled off when using the label paper, or the label paper is peeled off from the release paper on which many label papers are stuck. There are usage forms such as using.

  As shown in FIG. 1, when the label attached to the adherend 4 is peeled off, the cohesive failure occurs in the cohesive failure layer 2, and the release surface 2 a on the pressure-sensitive adhesive layer 3 side and the release on the base material 1 side. Separated into surface 2b. For this reason, even if it peels off two labels from which price display etc. differ, and tries to replace them, it cannot paste well, and unauthorized use will be prevented. FIG. 2 is an enlarged plan view of the release surface on the pressure-sensitive adhesive layer side after the label paper of FIG. 1 is peeled off.

  Next, an example of the back print label paper of the present invention will be described with reference to FIGS. The same reference numerals as those shown in FIGS. 1 and 2 indicate the same members. FIG. 3 shows a state in which a cohesive failure layer 2 is provided on one surface of a transparent substrate 1, and then the surface of the cohesive failure layer 2 is printed with characters or the like “print”. It shows that the pressure-sensitive adhesive layer 2 is provided on the surface of the cohesive failure layer 2 on the side.

  Examples of the printing method include gravure printing, offset printing, silk printing, and ink jet printing. Among these, it is more preferable to use one of methyl ethyl ketone, toluene, ethyl acetate, or a mixture of two or more thereof as the solvent of the ink used for printing. Further, as the ink, a pigment-based ink is more preferable than a dye-based ink in terms of weather resistance.

  The printed “print” of the printed character is received by the cohesive failure layer 2 having a porous structure as shown in FIG. 3 and penetrates from the surface to the substrate 1 side to reach the boundary surface with the substrate 1. . As a result, the characters “print” can be viewed from the other side of the transparent substrate 1. At this time, since the porous structure of the ink receiving portion of the cohesive failure layer 2 is dissolved or swollen by the solvent of the ink received in the cohesive failure layer 2 and is crushed and densified, the label as shown in FIG. When the paper is peeled off, the densified portion of the cohesive failure layer 2 is also cohesive and remains on the cohesive failure layer 2 remaining on the pressure-sensitive adhesive layer 3 side. "Can be identified.

  Moreover, since the printed "print" of the character is displayed in the boundary part with the transparent base material 1 in the cohesive failure layer 2 as mentioned above, and is protected by the base material 1, the other surface of the base material 1 Even if the side is rubbed or soiled, the letters “print” will not be blurred if you wipe them clean. In addition, the characters “print” cannot be scraped off from the other side of the substrate 1.

  Further, the back print label paper of the present invention can be used like a tape by being rolled.

  Hereinafter, examples and effects of the back print label paper of the present invention will be described. In the following description, “parts” in the component display in each composition means “parts by weight”.

A coating liquid of the following composition-1 is applied to the surface of a 100 μm thick biaxially stretched polyester film (Merinex 545 Teijin DuPont Films Co., Ltd.) with an applicator, immersed in water at 20 ° C. for 1 minute, and further at 90 ° C. After dipping in hot water for 5 seconds and draining, an antistatic agent was applied and dried at 80 ° C. to form a white and porous cohesive failure layer of 20 μm. Then, “print” is printed on the cohesive failure layer with a commercially available gravure ink (using blue) using MEK / toluene / ethyl acetate as a mixed solvent, and an adhesive (acrylic resin) is printed. The back printed label paper as an example of the present invention was prepared by providing it on the cohesive failure layer. When viewed from the other side of the cohesive failure layer of the base material, the letters “print”, which is the printing portion, were clearly projected on the base material side. Next, this material is affixed to a stainless steel plate as an adherend, peeled off after 5 minutes, and then peeled off between the layers of the cohesive failure layer, and the letters “print” are clearly visible on the adherend side layer. It remained. Of course, since the pressure-sensitive adhesive layer remains on the adherend side, the peeled label cannot be applied again to another place. The surface peel strength of this product was 0.416 [N / 25 mm], and the arithmetic average roughness was 0.72 [μm]. Further, the density of the surface layer was 0.73 [g / cm ³ ].

[Composition-1]
Acrylonitrile-styrene copolymer resin
(Lightac 120PCF, manufactured by Nippon A & L, 100% solid content) 7 parts light calcium carbonate
(Light calcium carbonate, manufactured by Maruo Calcium Co., Ltd., 100% solid content) 27 parts Titanium oxide (Taipek R-820, manufactured by Ishihara Sangyo Co., Ltd., 100% solid content) 3 parts dimethylformamide (solid content 0%) 60 parts plasticizer ( Dioctyl adipate, solid content 100%) 3 parts

The following composition-2 was applied to the surface of a 50 μm-thick biaxially oriented polypropylene film (Sun Orient PB-260 manufactured by Phutamura Chemical Co., Ltd.) with a bar coater, and an anchor coat layer was provided. Apply the working solution with an applicator, soak in water at 20 ° C for 1 minute, and then soak in hot water at 90 ° C for 5 seconds to drain, apply an antistatic agent, dry at 80 ° C, and dry to 20 µm white. A porous cohesive failure layer was formed. Then, after printing the letters “print” on the printed cohesive failure layer in the same manner as in Example 1 using the same gravure ink as in Example 1, the cohesive failure layer printed with an adhesive (acrylic resin) was used. A back print label sheet according to another example of the present invention was prepared at the top. When viewed from the other side of the cohesive failure layer of the base material, the letters “print” as the printing portion were clearly projected on the base material side as in Example 1. Next, this material is affixed to an iron plate as an adherend and peeled off after 5 minutes. When peeled off between the layers of the cohesive failure layer, the letters “print” remain clearly distinguishable on the adherend side layer. It was. Of course, it is the same as the first embodiment that it is impossible to put this label on another place. The surface peel strength of this product was 0.250 [N / 25 mm], and the arithmetic average roughness was 0.63 [μm]. Further, the density of the surface layer was 0.58 [g / cm ³ ].

[Composition-2]
Water (solid content 0%) 59 parts Styrene-acrylic resin emulsion (Acronal YJ2721Dap, Shinyo Chemical Co., solid content 46.5%) 37 parts Silica (Mizukasil P-801, Mizusawa Chemical Co., Ltd. solid content 100%) 2 parts Wetting agent (SN Wet 366, Sannopco, solid content 70%) 1 part Thickener (Primal RM8W, Rohm and Haas Japan, solid content 30%) 1 part

[Composition-3]
Acrylonitrile-styrene copolymer resin (Lightac 120PCF, manufactured by Nippon A & L Co., Ltd., 100% solid content) 8 parts Light calcium carbonate (Light calcium carbonate, Maruo Calcium Co., Ltd., solid content 100%) 18 parts Titanium oxide (Typaque R-820, Ishihara Sangyo Co., Ltd., solid content 100%) 2 parts dimethylformamide (solid content 0%) 69 parts plasticizer (dioctyl adipate, solid content 100%) 3 parts

[Evaluation method]
Peel strength is evaluated by the adhesive strength test method (based on JIS Z-0237). The label paper was affixed to a SUS304 steel plate using a manual tape pressing roll, and the strength was measured with a tensile tester (Strograph V1-C manufactured by Toyo Seiki Co., Ltd.).
The arithmetic average roughness was measured using a laser displacement meter (manufactured by Keyence Corporation) in accordance with JIS B-0601-1994.
The density was measured according to JIS P-8118.

  The present invention is a back print label that corresponds to the strength of case-by-case, such as those that steal the eyes quickly, such as supermarket labels, and those that slowly peel off, such as labels for branded and genuine products. Paper can be provided. Further, the back print label paper of the present invention can be suitably used as a price tag label, for example, because it does not become blurred or scraped off without being laminated, etc. Since the traces of the letters etc. remain, it is possible to immediately confirm the price of the product before being peeled off.

Sectional drawing of an example of the back print label paper to which this invention is applied. 2 is an enlarged plan view of the release surface on the pressure-sensitive adhesive layer side after the label paper of FIG. 1 is peeled off. Sectional drawing of an example of the back print label paper of this invention which printed on the back print label paper of FIG. FIG. 4 is a perspective view illustrating a state where a part of the label sheet of FIG. 3 is peeled off.

DESCRIPTION OF SYMBOLS 1 Base material 2 Ink receiving layer 3 Adhesive layer 4 Substrate P Character, etc.

Claims (4)

  In a label paper in which a cohesive failure layer having a porous structure is provided on one surface of a transparent substrate, characters are printed on the surface of the cohesive failure layer, and an adhesive layer is provided on the surface, the printed characters, etc. A back printed label sheet characterized by being viewed from the other side of the substrate.   2. The back print label paper according to claim 1, wherein the printing is performed using an ink whose main component is a solvent of any one of methyl ethyl ketone, toluene, ethyl acetate, or a mixture of two or more thereof.   The back print label paper according to claim 1 or 2, wherein the ink receiving portion on which the cohesive failure layer is printed is dissolved or swollen by an ink solvent, and the porous structure is crushed and densified. 2. The back print label paper according to claim 1, wherein the surface layer peel strength of the cohesive failure layer upon adhesion of the adhesive layer to the adherend is 0.10 to 0.90 N / 25 mm.

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