JP2001240832A - Pressure-sensitive adhesive composition and sheet for carrying information using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain both a pressure-sensitive adhesive composition having both a firm fixability on a paper and a high cohesive strength of an adhesive film without causing the wear or falling off of the adhesive during running through a printing machine, or a printer, etc., and a sheet for carrying information using the pressure-sensitive adhesive composition. SOLUTION: This pressure-sensitive adhesive composition is obtained by compounding 100 pts. mass of an adhesive base prepared by compounding 100 pts. mass of the solid content of a methyl methacrylate graft-copolymerized natural rubber-based adhesive with a polystyrene emulsion so as to provide 5-50 pts. mass of the solid content of the polystyrene emulsion with 100-250 pts. mass of a particulate filler exhibiting the nonaffinity for the adhesive base. The sheet for carrying the information is obtained by using the pressure-sensitive adhesive composition.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure-sensitive adhesive composition and an information-bearing sheet using the same, and more particularly, to a folded sheet having an information-bearing surface formed by folding or cutting. , An information transmission sheet having a confidentiality such as a superimposed sheet, an information transmission sheet such as an office sheet such as a scalable sheet and copy paper, and a pressure-sensitive adhesive composition used for the same Things.

[0002]

2. Description of the Related Art Conventionally, in an information carrying sheet for carrying information on a superposed surface, the superposed surfaces are usually arranged in a pattern such that they are brought into contact with each other so that the superposed surfaces are bonded to each other. An adhesive layer of a pressure-sensitive adhesive is provided on the entire surface, a specific portion, or linearly. This pressure-sensitive adhesive is also referred to as a self-adhesive pressure-sensitive adhesive, and is a type in which polymers are adhered to each other by self-diffusion by applying a high pressure while the adhesive layers are in contact with each other.
Depending on the type of the composition and the degree of the pressure, permanent adhesiveness and removable adhesiveness are realized.

Conventionally, the main component of the pressure-sensitive adhesive used in this type of information-carrying sheet is generally a methyl methacrylate graft copolymerized natural rubber-based adhesive or a methyl methacrylate-styrene graft copolymerized natural rubber-based adhesive. It contains an agent as a main component. However, pressure-sensitive adhesives containing methyl methacrylate graft copolymer natural rubber-based adhesive as the main component have poor fixability to paper and low cohesive strength of the adhesive film, so they adhere while running on printing machines and printers. There was a problem that the agent was worn and dropped off.

[0004]

SUMMARY OF THE INVENTION A first object of the present invention is to provide a pressure-sensitive adhesive composition containing a methyl methacrylate graft copolymerized natural rubber-based pressure-sensitive adhesive as a main component, which has solved the conventional problems. It is to provide a pressure-sensitive adhesive composition in which the adhesiveness to paper and the cohesive force of the adhesive film are both strong, and the adhesive is not worn or dropped off while running a printing machine or a printer, A second object of the present invention is to provide an information carrying sheet using such a pressure-sensitive adhesive composition.

[0005]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to solve the above-mentioned problems, and as a result, an adhesive base obtained by mixing a specific amount of a polystyrene emulsion with a methyl methacrylate graft copolymerized natural rubber-based adhesive. For the agent, found that the problem can be solved by using a pressure-sensitive adhesive composition in which a specific amount of a fine particulate filler showing incompatibility is blended,
The present invention has been completed.

That is, the pressure-sensitive adhesive composition according to the first aspect of the present invention is applied to a superposed surface of a sheet, and forms an adhesive layer which does not adhere in a normal state by a drying treatment. A pressure-sensitive adhesive that is brought into contact with and applied with a predetermined pressure so that the superposed surfaces can be peelably adhered to each other. The polystyrene is added to 100 parts by mass of a methyl methacrylate graft natural rubber-based pressure-sensitive adhesive solid content. With respect to 100 parts by mass of the adhesive base obtained by blending the emulsion so that the solid content is 5 to 50 parts by mass,
1 particulate filler showing non-affinity for this adhesive base
100 to 250 parts by mass.

According to the pressure-sensitive adhesive composition according to the first aspect of the present invention, the pressure-sensitive adhesive composition is prepared by adding a specific amount of a polystyrene emulsion to a methyl methacrylate graft copolymerized natural rubber-based pressure-sensitive adhesive. Since a pressure-sensitive adhesive composition containing a specific amount of a particulate filler exhibiting affinity was used, the composition was applied to the overlapping surface of the sheets, and an adhesive layer that did not adhere in a normal state was formed by a drying process. After strong pressure is applied and adhered to each other in a state where they are in contact with each other, they can be easily peeled off when necessary. And the pressure-sensitive adhesive composition according to claim 1 of the present invention has fixability to paper,
The cohesive force of the adhesive film is appropriately high, so that the adhesive does not wear out or fall off while running on a printing machine or a printer.

According to a second aspect of the present invention, there is provided an information carrying sheet having an adhesive layer of the pressure-sensitive adhesive composition according to the first aspect at a predetermined portion of a superposed surface of a base sheet. I do.

In the information-carrying sheet according to the second aspect of the present invention, a sufficient adhesive force can be obtained by applying a strong pressure while keeping the superposed surfaces in contact with each other to adhere them together. Can be easily peeled.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.
The pressure-sensitive adhesive composition of the present invention does not adhere in a normal state, adheres under pressure, and has an adhesive layer that can be peeled off when necessary, that is, has a transparency to form a so-called adhesive layer, As an adhesive base, a mixture prepared by mixing a polystyrene emulsion with a solid content of 5 to 50 parts by mass based on 100 parts by mass of a solid content of a methyl methacrylate graft copolymerized natural rubber-based pressure-sensitive adhesive was used. 100 to 250 parts by mass of a non-affinity fine particulate filler is mixed with 100 parts by mass of the adhesive base.

The methyl methacrylate graft copolymerized natural rubber-based pressure-sensitive adhesive used in the pressure-sensitive adhesive composition of the present invention is a natural rubber-based pressure-sensitive adhesive graft-copolymerized with methyl methacrylate (based on 100 parts by weight of natural rubber). Grafted with about 10 to 40 parts by mass of methyl methacrylate), and a natural rubber latex conventionally used as a base of a natural rubber-based pressure-sensitive adhesive can be used.

The polystyrene emulsion used in the pressure-sensitive adhesive composition of the present invention is a synthetic latex generally used as a component for impregnation, reinforcement of other latex, etc., and is an emulsion obtained by dispersing polystyrene in an aqueous solvent. It is. At this time, an emulsifier is required to stabilize the dispersion of the particles. As the emulsifier, rosin soap, naphthalene sulfonate,
Anionic surfactants such as fatty acid soaps and alkylbenzene sulfonates are used.

Specific examples of commercially available polystyrene emulsions used in the pressure-sensitive adhesive composition of the present invention include, for example, Nipol LX-303 (Zeon Corporation) and
Asahi Kasei Latex L-8801 (Asahi Kasei Corporation), C-
20 (Showa High Polymer Co., Ltd.).

If necessary, a synthetic resin emulsion can be mixed with a mixture of the methyl methacrylate graft copolymer natural rubber-based pressure-sensitive adhesive and the above-mentioned polystyrene emulsion. Examples of the synthetic resin emulsion include a polyvinyl acetate emulsion, a vinyl acetate-ethylene copolymer emulsion, a polyacrylate emulsion, and a polyvinyl chloride emulsion.
In order to stabilize the dispersion of these synthetic resin emulsions, the above-mentioned emulsifier can be used. This synthetic resin emulsion has a glass transition point of -20 ° C to 10 ° C.
° C is preferred.

The mixing ratio of the polystyrene emulsion is as follows:
The polystyrene emulsion is blended such that the solid content of the polystyrene emulsion is 5 to 50 parts by mass, preferably 10 to 50 parts by mass, based on 100 parts by mass of the solid content of the methyl methacrylate graft copolymerized natural rubber-based pressure-sensitive adhesive.

In the present invention, it is preferable to blend the polystyrene emulsion so that the total amount of the methyl methacrylate grafted on the natural rubber and the polystyrene emulsion is in the range of 20 to 60 parts by mass (solid content).

The mixing ratio of the methyl methacrylate graft copolymer natural rubber-based pressure-sensitive adhesive and the polystyrene emulsion depends on the adhesive strength of the adhesive layer, the fixability to a base sheet made of a material such as paper and synthetic paper, and the adhesive layer film. Since it affects the balance with cohesion, it is necessary to adjust it appropriately. If the solid content of the polystyrene emulsion is less than 5 parts by mass and the amount of the methyl methacrylate graft copolymerized natural rubber-based pressure-sensitive adhesive is excessive, the fixability of the adhesive layer to the base sheet surface is reduced and the abrasion resistance is poor. If the solids content of the polystyrene emulsion exceeds 50 parts by mass, the adhesive strength between the adhesive layers on the superposed surface is reduced, so that appropriate peeling performance cannot be obtained and wear resistance is poor. Therefore, the mixing ratio of the methyl methacrylate graft copolymer natural rubber-based pressure-sensitive adhesive and the polystyrene emulsion needs to be within the above range.

The thus obtained adhesive base comprising a mixture of a methyl methacrylate graft copolymerized natural rubber-based pressure-sensitive adhesive and a polystyrene emulsion may optionally contain additives commonly used for pressure-sensitive adhesives. For example, a tackifier, a viscosity modifier, an antioxidant, a stabilizer, a coloring agent, and the like can be added.

In the pressure-sensitive adhesive composition of the present invention, a fine particle filler having an incompatibility with the adhesive base is blended. As the fine particle filler, one having a small affinity for the adhesive base and having a regular particle shape is preferably used since it is necessary to prevent the adhesive layer from impairing the transparency. As such, for example, various starch-based, synthetic zeolite, fine spherical acrylic resin, fine spherical methacrylic resin, fine spherical polyethylene, spherical alumina,
Glass powder, shirasu balloon, activated clay and the like can be mentioned. These fine particle fillers may be used alone,
Two or more kinds may be used in combination. However, silica, titanium oxide, zinc oxide, etc., which have been conventionally used as a particulate filler for this kind of pressure-sensitive adhesive composition,
Since the particle shape is irregular, there is a fear that the irregular reflection of light is promoted in the adhesive layer, thereby impairing the transparency. Therefore, these should not be added, or even if they are added, the amount of addition should be 10% by mass or less. It is preferable that these fine particle fillers have an average particle diameter of 10 μm or less, preferably 0.5 μm. In particular, colloidal silica (silica gel) with an average particle size of 0.1 μm or less
The use of is advantageous because the fixability to UV ink can be improved.

Further, in the pressure-sensitive adhesive composition of the present invention, 100 to 250 parts by mass of a fine particle filler having an incompatibility with the adhesive base is added to 100 parts by mass of the adhesive base. Preferably it is compounded in the range of 130 to 250 parts by mass, more preferably 150 to 200 parts by mass. If the blending amount of the fine particle filler is too small at less than 100 parts by mass, the blocking resistance is reduced, or the adhesive strength is too strong to be easily peeled off. The force becomes too low and does not show sufficient tackiness.

The pressure-sensitive adhesive composition of the present invention is applied to a base sheet surface by a coating means such as a gravure coater, flexo, air knife coater, bar coater, etc., and is folded in two, three, folded or separated, or separated. It can be suitably used for postcards, spreadsheets, notices, various cards, etc., which have a double-sided surface that is temporarily adhered in various forms such as superposition, but can be easily peeled off as needed.

Next, as the base sheet on which the pressure-sensitive adhesive composition of the present invention is applied, in addition to ordinary paper, synthetic paper or a synthetic film of polyethylene, polyethylene terephthalate, polypropylene, vinyl chloride or the like is used. You can also. When using these synthetic films, the surface of the base sheet is preferably subjected to a surface treatment such as a mat treatment or a corona treatment. The coating amount of the pressure-sensitive adhesive composition to the substrate sheet surface, the adhesion of the adhesive layer, for the release of, or transparency maintained, 1 to 30 g / m ^2, preferably from 3 to 20 g / m ^2, More preferably, 5 to 15
g / m ² . Furthermore, by pressing the formed peelable adhesive layer with a pressure roller, the blocking resistance can be further improved.

Next, the configuration of the information carrying sheet of the present invention will be described in detail with reference to the accompanying drawings. Here, FIG.
FIG. 2 is a front view of the three-fold postcard of the present invention, FIG. 2 is a rear view of the postcard, FIG. 3 is a cross-sectional view taken along line XX of FIG.
FIG. 5 is an explanatory view of the state when the postcard of FIG. 1 is folded, FIG. 5 is a front view of the folded postcard of the present invention, FIG. 6 is a developed view of the back side of the postcard, and FIG. 8 and FIG. 8 are front development views of the partially folded postcard according to the present invention, FIG. 9 is a rear development view of the postcard, and FIG. 10 is a state explanatory view when the postcard of FIG. 8 is folded.

First, a three-fold postcard 1 shown in FIGS. 1 to 3 is composed of a base sheet 2 having a size three times the size of a standard postcard, and is divided into three regions by folding lines 3a and 3b. is there. On the front surface of the left section area A, print destination information such as a zip code, a destination name, and an address.
However, concealment information prints 5 are printed directly on the base sheet 2 on the front and back surfaces of the central partitioned area B and on the front face of the right partitioned area C. Further, the pressure-sensitive adhesive composition of the present invention is applied to the entire front surfaces of the divided regions B and C and the whole back surfaces of the divided regions A and B of the printed base sheet 2 by the adhesive layer 6 which can be peeled off. Is formed. As shown in FIG. 4, the tri-fold postcard 1 configured as described above folds the overlapping surface of each section into a Z-shape along the folding lines 3a and 3b to bring the adhesive layers into contact with each other. By pressing with a sealer, the adhesive layer 6 is activated and adhered.

Next, a two-fold postcard 11 shown in FIGS. 5 and 6 is composed of a base sheet 2 having a size twice as large as the standard postcard size, and is divided into two regions D and E by a folding line 3 at the center. It is what is divided. A destination information print 4 such as a postal code, a destination name and an address is printed on the front surface of the left section area D, and a concealment information print 5 is printed directly on the base sheet 2 on the back sides of the section areas D and E. . further,
The pressure-sensitive adhesive composition of the present invention is applied to the entire back surface of the divided areas D and E of the printed base sheet 2 to form a peelable adhesive layer 6. As shown in FIG. 7, the two-fold postcard 11 configured as described above is folded and pressed at the fold line 3 so that the adhesive layers on the right and left rear surfaces are in contact with each other, similarly to the above-described three-fold postcard. The adhesive layer 6 is activated and adhered.

8 and 9 is composed of a base sheet 2 having a size 1.5 times the size of a standard postcard. And G. The postal code, address,
A destination information print 4 such as an address, and a concealment information print 5 is printed directly on the base sheet 2 on the back surface of the right side divided area G. Further, the pressure-sensitive adhesive composition of the present invention is applied to the entire back surface of the partitioned area G of the printed base sheet 2 and a part of the back face of the partitioned area F which is overlapped when the partitioned area G is folded along the folding line 3. Adhesive layer 6 to which object is applied and which can be peeled off
Are formed. As shown in FIG. 10, the partially folded postcard 21 configured as described above is folded and pressed at the folding line 3 so that the adhesive layers on the back surfaces of the left and right sections are in contact with each other, similarly to the above-described two-fold postcard. Thereby, the adhesive layer 6 is activated and adhered.

Further, the peelable adhesive layer formed by the pressure-sensitive adhesive composition of the present invention itself also has a receptivity for printing ink and toner. Alternatively, additional information (not shown) can be printed by a non-impact printer.

[0028]

The present invention will be described in more detail with reference to the following Examples and Comparative Examples, but the present invention is not limited to these Examples. Example 1 Methyl methacrylate (MMA) graft copolymer natural rubber (NR) 100
MMA graft copolymerized natural rubber emulsion 1 obtained by mixing and mass-producing MMA and 10 parts by weight of MMA
A polystyrene emulsion (Nipol LX303, Nippon Zeon Co., Ltd.), Asahi Kasei Latex L-8801 (Asahi Kasei Corp.), or C-20 (Showa Kogaku Co., Ltd.) The pressure-sensitive adhesive composition of the present invention was prepared by blending 50 parts by mass of silica gel and 125 parts by mass of starch with respect to 100 parts by mass of the adhesive base blended to give 10 parts by mass. The pressure-sensitive adhesive composition of the present invention is applied to a coated paper having a continuous weight of 110 kg by a gravure offset method at a rate of 10 g / m ² to form an adhesive layer, and then heated at 120 ° C. for 30 seconds and dried. Processed. 90 ° peeling (T-peeling) adhesive strength immediately after the production of the information carrying sheet thus produced,
The blocking resistance and abrasion resistance were evaluated by the following methods, and the evaluation results are shown in Table 1.

(1) Method of measuring 90 ° peeling (T-shaped peeling) adhesive force: The obtained information carrying sheet was cut into a width of 25 mm and a length of 100 mm to prepare a sample. And a pressure of 9.8 Pa was applied and crimped. Adhesive peel adhesion test method JIS K68
According to No. 54, 90 ° peeling (T-peeling) adhesive strength is measured using an Autograph AGS50 (manufactured by Shimadzu Corporation). ◎: 100 to 150 (gf / 25 mm) ：: 150 to 200 (gf / 25 mm) or 50 to
100 (gf / 25 mm) Δ: 200 to 300 (gf / 25 mm) or 30 to
50 (gf / 25 mm) ×: 300 (gf / 25 mm) or more or 30 (gf / 25 mm)
/ 25mm) or less ◎: Excellent, ○: Good, △: Acceptable, ×: Not Acceptable

(2) Blocking resistance 500 g / c
After applying a pressure of m ² and leaving at 50 ° C. for 30 minutes, the peel strength was measured. Blocking resistance (peel strength) (g / c
m): 2 or less, ◎;
Those in the range of 5 to 10 were marked with Δ, those with 10 or more were marked with x. For the measurement of the peel strength, a tensile tester Autograph AGS50 manufactured by Shimadzu Corporation was used. ◎: Excellent, ○: Good, △: Acceptable, ×: Not Acceptable

(3) Abrasion Resistance Using a paperboard abrasion tester, the surface of the adhesive layer when worn 100 times was visually judged to determine the degree of wear. As a result, the ratio of the broken area of the tested area was 10% or less: 、, 30% or less: 、, 50% or less: Δ, 51% or more: ×. ◎: Excellent, ○: Good, △: Acceptable, ×: Not Acceptable

(Examples 2 to 8) A pressure-sensitive adhesive composition of the present invention was prepared in the same manner as in Example 1 except that the mixing ratio of each component shown in Table 1 was used. The 90 ° peeling (T-peeling) adhesive strength, blocking resistance, and abrasion resistance of the information carrying sheet obtained as described above were evaluated, and the evaluation results are shown in Table 1.

(Comparative Example 1) A comparison was made in the same manner as in Example 1 except that the blending amount of the fine particulate filler was larger than the upper limit of the range of the present invention and the blending ratio of each component shown in Table 2 was used. The pressure-sensitive adhesive composition was prepared, and the 90 ° peeling (T-peeling) adhesive force, blocking resistance, and abrasion resistance of the information carrying sheet obtained in the same manner as in Example 1 were evaluated. It is shown in Table 2.

(Comparative Example 2) A comparison was made in the same manner as in Example 1 except that the blending amount of the fine particulate filler was made smaller than the lower limit of the range of the present invention and the blending ratio of each component shown in Table 2 was used. The pressure-sensitive adhesive composition was prepared, and the 90 ° peeling (T-peeling) adhesive force, blocking resistance, and abrasion resistance of the information carrying sheet obtained in the same manner as in Example 1 were evaluated. It is shown in Table 2.

(Comparative Example 3) A comparison feeling was obtained in the same manner as in Example 1 except that the blending amount of the polystyrene emulsion was smaller than the lower limit of the range of the present invention and the blending ratio of each component shown in Table 2 was used. A pressure-sensitive adhesive composition was prepared, and an information carrying sheet obtained in the same manner as in Example 1 was peeled at 90 ° (T-peeling).
The adhesive strength, blocking resistance, and abrasion resistance were evaluated, and the evaluation results are shown in Table 2.

Comparative Example 4 A comparison was made in the same manner as in Example 1 except that the blending amount of the fine particulate filler was larger than the upper limit of the range of the present invention and the blending ratio of each component shown in Table 2 was used. The pressure-sensitive adhesive composition was prepared, and the 90 ° peeling (T-peeling) adhesive force, blocking resistance, and abrasion resistance of the information carrying sheet obtained in the same manner as in Example 1 were evaluated. It is shown in Table 2.

(Comparative Example 5) Comparative Example 5 was carried out in the same manner as in Example 1 except that the blending amount of the fine particulate filler was smaller than the lower limit of the range of the present invention and the blending ratio of each component shown in Table 2 was used. The pressure-sensitive adhesive composition was prepared, and the 90 ° peeling (T-peeling) adhesive force, blocking resistance, and abrasion resistance of the information carrying sheet obtained in the same manner as in Example 1 were evaluated. It is shown in Table 2.

(Comparative Example 6) A comparison feeling was obtained in the same manner as in Example 1 except that the blending amount of the polystyrene emulsion was larger than the upper limit of the range of the present invention and the blending ratio of each component shown in Table 2 was used. A pressure-sensitive adhesive composition was prepared, and the 90 ° -peeling (T-peeling) adhesive force, blocking resistance, and abrasion resistance of the information-carrying sheet obtained in the same manner as in Example 1 were evaluated. Shown in

[0039]

[Table 1]

[0040]

[Table 2]

From Tables 1 and 2, the pressure-sensitive adhesive compositions of the present invention of Examples 1 to 8 are all excellent in 90 ° peeling (T-peeling) adhesive strength, blocking resistance and abrasion resistance. However, it can be seen that the pressure-sensitive adhesive compositions of Comparative Examples 1 to 6 are inferior in any one or two or more of them.

[0042]

The pressure-sensitive adhesive composition according to claim 1 of the present invention is a pressure-sensitive adhesive composition containing a methyl methacrylate graft copolymerized natural rubber-based pressure-sensitive adhesive as a main component, Both the fixing property and the cohesive force of the adhesive film are appropriately strong,
The adhesive has a remarkable effect that the adhesive does not wear or fall off during running on a printing machine or a printer.

In the information-carrying sheet according to the second aspect of the present invention, when the superposed surfaces are brought into contact with each other and a strong pressure is applied to adhere them together, sufficient adhesion is obtained, and the sheet is peeled off as required. In such a case, there is an effect that it can be easily performed.

[Brief description of the drawings]

FIG. 1 is a surface development view of a three-fold postcard according to the present invention.

FIG. 2 is a developed rear view of the postcard of FIG. 1;

FIG. 3 is a sectional view taken along line XX of FIG. 1;

FIG. 4 is an explanatory view of the state when the postcard of FIG. 1 is folded.

FIG. 5 is a surface development view of the two-fold postcard of the present invention.

FIG. 6 is a developed rear view of the postcard of FIG. 5;

FIG. 7 is an explanatory diagram of a state when the postcard of FIG. 5 is folded.

FIG. 8 is a surface development view of a partially folded postcard according to the present invention.

FIG. 9 is a developed rear view of the postcard of FIG. 8;

FIG. 10 is an explanatory view of the state when the postcard of FIG. 8 is folded.

[Explanation of symbols]

 2, 12, 22 Base sheet 3, 3a, 3b Folding line 5 Concealment information printing 6 Peelable adhesive layer

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2C005 WA02 4J040 DA022 DB032 DC022 DE022 DE032 DF002 DL031 HA116 HA316 HA346 JA09 JB09 KA03 KA42 MA09 MB03 MB09 NA05

Claims (2)

[Claims] An adhesive layer which is applied to a superposed surface of a sheet and which does not adhere in a normal state by a drying process is formed, and the superposed surfaces are brought into contact with each other and a predetermined pressure is applied thereto, whereby the superposed surface is formed. A pressure-sensitive adhesive for releasably adhering each other, wherein a polystyrene emulsion is blended with 100 parts by mass of a solid component of a methyl methacrylate graft copolymerized natural rubber-based adhesive so that the solid content is 5 to 50 parts by mass. For 100 parts by mass of the resulting adhesive base,
1 particulate filler showing non-affinity for this adhesive base
A pressure-sensitive adhesive composition, which is contained in an amount of from 00 to 250 parts by mass. 2. An information carrying sheet having an adhesive layer of the pressure-sensitive adhesive composition according to claim 1 on a predetermined portion of a superposed surface of a base sheet.