JP2005205725A - False adhesive paper - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a false adhesive paper excellent in a low cost and a masking nature. <P>SOLUTION: The false adhesive paper has a false adhesive layer which does not adhere under an ordinary condition and can releasably and falsely adhere when a specified condition is provided on at least one face of the surface and the back surface of a base paper. The base paper has a laminated structure with at least three layers of paper layers, and between the surface side paper layer positioned at the most surface side and the back surface side paper layer positioned at the most back surface side, an intermediate paper layer with a ground color different from a ground color of at least one paper layer of the surface side paper layer and the back surface side paper layer, is provided. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a pseudo-adhesive paper that has a function of temporarily adhering but easily peeling when necessary. More specifically, a pseudo-adhesive layer that is not bonded in a normal state but has an adhesive property by pressure or the like and can be re-peeled after bonding is provided on at least one side of the base paper. The present invention relates to a pseudo-adhesive paper suitable for folding pseudo-adhesive paper, superposed pseudo-adhesive paper, other confidential information hiding paper, confidential postcards, confidential envelopes, and the like.

  Folding a postcard with a reciprocal postcard with various information such as personal information folded on it, fusing the superimposed parts, concealing the information, mailing it, and the recipient peeling the pseudo-adhesive part Postcard systems that read concealment information are widespread. The postcard system is often used when a company communicates confidential information to an employee or a bank or credit company to a customer, and leakage prevention of confidential information is important.

  In such a postcard system, usually, temporary adhesive is applied by applying a predetermined pressure or the like by applying a pseudo-adhesive based on natural rubber or the like to at least one of the front and back surfaces of the base paper. In this case, pseudo-adhesive paper provided with a pseudo-adhesive layer that is bonded but easily peeled off when necessary is used.

Therefore, in this type of pseudo-adhesive paper, various improvements have been made in order to improve the leakage prevention property (concealment property) of the confidential information listed above. As the improvement, for example, a method of printing a complicated ground pattern on the front or back surface of the base paper that makes it difficult to visually recognize from the outside through concealment information printed on the surface folded inside, A method is employed in which a coating layer containing a large amount of pigment is formed on the front or back surface of a base paper.
JP 2003-105287 A JP2003-072265 JP2002-023643

  However, the former method of applying a complicated ground pattern to improve the concealment is expensive to print a complicated ground pattern. In addition, other information such as address information cannot be printed on the part where the ground pattern is applied, and the complicated operation such as printing the address print on a separate sheet and bonding the address description sheet to the base sheet. Is required. On the other hand, the latter method of providing the pigment layer can increase the concealing property if the coating thickness of the pigment layer is increased, but the surface strength decreases when the coating thickness is increased, so that re-peeling is necessary. The possibility that the pigment layer on the surface peels and it becomes difficult to read the concealment information increases.

  Accordingly, a main object of the present invention is to provide a pseudo-adhesive paper having a high surface strength and a high concealing property without printing a complicated character pattern.

The present invention that has solved the above problems is as follows.
<Invention of Claim 1>
A pseudo-adhesive paper having a pseudo-adhesive layer that pseudo-adhesively peels off when a predetermined condition is given without adhering to at least one side of the front and back surfaces of the base paper in a normal state,
The base paper has a laminated structure having three or more paper layers, and the front side paper is between a front side paper layer located on the most front side and a back side paper layer located on the back side. A pseudo-adhesive paper characterized in that an intermediate paper layer having a ground color different from the ground color of at least one of the paper layer and the back side paper layer is provided.

<Invention of Claim 2>
A pseudo-adhesive paper having a pseudo-adhesive layer that pseudo-adhesively peels off when a predetermined condition is given without adhering to at least one side of the front and back surfaces of the base paper in a normal state,
The base paper has a laminated structure having two or more paper layers, and the ground color of the top paper side layer located on the top surface side or the back side paper layer located on the back side is different from each other. A pseudo-adhesive paper characterized by that.

  According to the present invention, the base paper has a laminated structure having three or more paper layers, and the front side paper layer located on the most front side and the back side paper layer located on the most back side, Since an intermediate paper layer having a ground color different from the ground color of at least one of the front side paper layer and the back side paper layer is provided, the paper layer constituting the printing surface (the paper layer constituting the front side or the back side) Is a paper layer colored in a color that makes printing information conspicuous, or a non-colored or white paper layer that is excellent in printability, and any other intermediate paper layer is colored in the same color as the printing information or If the paper layer is colored in a color with increased opacity, the possibility that the concealment information can be seen through can be significantly reduced without making it difficult to see the concealment information.

  In the present invention, “coloring” means that a color is added to the entire paper layer by adding a colorant or the like in the manufacturing stage of the paper layer (a colored pattern is dispersed throughout the paper layer to give a pattern). ).

  Further, if the paper layer located on the most surface side and the paper layer located on the most back side among the paper layers are colored in different colors, it is easy to determine the front and back surfaces. In addition, for example, when a paper layer excellent in printing suitability on one side and a paper layer excellent in pseudo-adhesive coating suitability on the other side are provided, on either side when applying the pseudo adhesive It becomes possible to instantly determine whether or not the pseudo adhesive may be applied. If the paper layer on the printing surface is colored in a color where the printing information is conspicuous, for example, the color where the printing color and hue are located on the opposite side, and the paper layer on the opposite side to the printing surface is colored in the same color as the printing color, the concealment information will be You won't see through. In this case, it is more economical and easier to manufacture than, for example, color separation of the front and back surfaces by printing or background pattern printing.

Next, the best mode for carrying out the present invention will be described in detail below.
The present invention is a pseudo-adhesive paper having a pseudo-adhesive layer that is pseudo-adhesively peelable when a predetermined condition is given to at least one of the front and back surfaces of the base paper without being bonded in a normal state.

  The base paper has a laminated structure having three or more paper layers, and the front surface is located between the front side paper layer located on the most front side and the back side paper layer located on the back side. An intermediate paper layer having a ground color different from the ground color of at least one of the side paper layer and the back side paper layer is provided. Alternatively, the base paper has a laminated structure having two or more paper layers, and the surface paper side layer located on the most surface side or the ground color of the back side paper layer located on the most back side are different from each other. It is characterized by being a colored paper layer.

  In making the base paper into a laminated structure, a conventionally known manufacturing method by multilayer printing that obtains a laminated paper by pressing a colored or non-colored wet paper, or a conventionally known production in which a dried paper is bonded. It can be achieved by the method. In the case of multi-layer papermaking, a conventionally known multi-layer paper machine having a pressing unit that presses wet paper flowing from a plurality of wire portions in a stacked manner can be used. Other types of paper machines are not limited. Formats such as a long paper machine, a circular paper machine, a twin wire paper machine, and a combination machine can be used. In the case of bonding, a conventionally known bonding method using an adhesive can be used. The adhesive in this case is not a pseudo-adhesive but a non-peelable adhesive. As such an adhesive, an adhesive conventionally used for this kind of application can be used without any problem.

The number of paper layers is not limited as long as the base paper has two or three or more paper layers. The base weight of the base paper is changed as appropriate according to the intended use. When used for a postcard system that requires concealment, it is preferably about 50 to 150 g / m ² .

  In coloring the base paper, it can be colored by adding a dye to the pulp slurry as a raw material. Examples of such a dye include a direct dye, a basic dye, and an acid dye, and the direct dye is most used. From the chemical structure, it can be divided into azo, stilbene, thiazole, dioxane and the like. The addition amount and color of the dye are not particularly limited, but may be appropriately determined in consideration of the color and density of the ink used for information recording. The colored paper layer is preferably the same color as the ink used for printing the recorded information.

  On the other hand, in the present invention, the pseudo adhesive layer is not particularly limited, and may be formed by applying a conventionally known pseudo adhesive to at least one of the front and back surfaces of the base paper. As the pseudo-adhesive, a conventionally known pseudo-adhesive can be used. For example, a non-peelable adhesive (hereinafter referred to as an adhesive base) is mixed with a filler exhibiting non-affinity to provide pseudo-adhesive strength. A conventionally known pseudo-adhesive imparted with can be used. As the adhesive base, it can be arbitrarily selected from those conventionally used for usual adhesive bases such as latex, specifically natural rubber, synthetic rubber, etc. Sulfur-free vulcanized natural rubber latex mixed with methyl methacrylate, natural rubber latex obtained by graft copolymerization of methyl methacrylate with natural rubber, acrylic modified rubber latex, rubber latex and protective colloidal acrylic copolymer A mixture with a polymerized emulsion is preferred in terms of blocking resistance, resistance to deterioration over time, and the like.

  Examples of the filler added to the adhesive base include clay, calcite-based precipitated calcium carbonate forming primary or secondary aggregates, and aragonite-based precipitated carbonic acid forming secondary aggregates. Calcium, calcium carbonate, styrene beads, silica, synthetic fine-particle silica, amino surface-modified silica, wax surface-treated silica, spherical silica, ordinary calcium, and oxides and hydroxides of metals such as zinc, magnesium, aluminum or titanium , Carbonate, silicate, or a mixture thereof. Preferred are clay and calcium carbonate.

  What is necessary is just to apply the pseudo-adhesive to the base paper according to a conventionally known coating method. For example, off-machine coating may be performed with a coating machine such as a blade coater, curtain coater, rod coater or air knife coater, gate roll coater, bill blade coater, rod metering coater, 2 roll coater or spray coater. On-machine coating may be performed with a coating machine.

The application amount of the pseudo adhesive may be applied with reference to a conventionally known application amount. It is desirable to set to about ³ to 15 g / m ² . If it is less than 3 g / m ² , the desired adhesive strength cannot be obtained and unintended peeling tends to occur, and if it exceeds 15 g / m ² , the adhesive strength becomes too strong to be peeled off. Sometimes glue sticks to the coating roll, and operational and quality problems are likely to occur.

The thickness of the pseudo adhesive layer formed by such coating is preferably 5 to 20 μm. Further, in order to obtain a uniform pseudo-adhesive layer, it is preferable to press the surface of the pseudo-adhesive layer at about 1 to 10 kg / cm ² after coating to flatten excessive protrusion on the surface of the pseudo-adhesive layer. .

  In the present invention, it is not limited whether the pseudo adhesive layer or the other coating layer provided together with the pseudo adhesive layer on the base paper has a laminated structure or a single layer structure.

Pseudo-adhesive paper (Examples 1 and 2) having a laminated structure according to the present embodiment and having a colored paper layer and a single-layer base paper made of high-quality paper having a basis weight of 104 g / m ² ( Conventional example 1), pseudo-adhesive paper (conventional example 2) using coated paper obtained by applying a coating liquid containing a pigment as a main component and a binder on the high-quality paper as a base paper, and tint block printing on high-quality paper A comparative test was performed on the applied pseudo-adhesive paper (Conventional Example 3) in terms of concealability, peelability, printability, and cost.

(Base paper)
Example 1: Using a multilayer paper machine, a front paper layer and a back paper layer were formed from a bleach-free uncolored pulp slurry, and a black dye (Nippon Kayaku Co., Ltd .: Kayacel Black CN Liquid) was used. A base paper having a three-layer structure was used, which was added and made in gray so that an intermediate paper layer was formed from a colored pulp slurry. The basis weight of the papermaking raw material in each of the front paper layer, back paper layer, and intermediate paper layer was the same, and the rice paper weight after papermaking was 104 g / m ² .
Example 2: Using a multilayer paper machine, a surface paper layer is formed from a bleach-free uncolored pulp slurry, and a black dye (Nippon Kayaku Co., Ltd .: Kayacel Black CN Liquid) is added to make it gray. A base paper having a two-layer structure was used in which paper was made from a colored pulp slurry so that a back paper layer was formed. The basis weight of the papermaking raw material for the front paper layer and the back paper layer was the same, and the rice paper weight after papermaking was 104 g / m ² .
Conventional Example 1: A single-layer and uncolored high-quality paper having a weight of 104 g / m ² was used as a base paper.
Conventional Example 2: A coating layer was formed by coating 4 g / m ^{2 of a} coating liquid containing a pigment as a main component and a binder on a single-layer, uncolored high-quality paper having a weight of 104 g / m ² with a blade coater. Coated paper was used as the base paper.
Conventional Example 3: A single-layer high-quality paper having a basis weight of 104 g / m ² was used as a base paper, and after the next pseudo-adhesive paint layer was formed, a gray background pattern was printed on one side by an offset printer.

(Pseudo adhesive layer)
The pseudo-adhesive layer in each of the examples and the conventional examples includes a pseudo-adhesive paint containing 80 parts by weight of silica, 20 parts by weight of SBR latex, and 15 parts by weight of a water-soluble binder with respect to 100 parts by weight of natural rubber latex. It was formed by coating with a coater at a coating amount of 9 g / m ² . For Example 2, a coating layer was formed on the colored backside paper layer. For Conventional Example 2, a pseudo adhesive layer was formed on the coating layer forming surface.

Details of the tests performed on the examples and the conventional examples are as follows.
<Concealment test>
The test was performed by pseudo-bonding a sample printed with 5 characters arbitrarily with black ink and a non-printed sample using an inkjet printer (Pixus 850i: manufactured by Canon Inc.) from the opposite side of the print surface. It was determined whether the printed characters could be read visually. The evaluation was good (◯) when the characters could not be read by visual inspection, acceptable (Δ) when the characters were partially readable, and impossible (×) when all characters were readable.

<Peelability test>
A set of two sheets is used as one sample (width 50 mm × length 100 mm), and the pseudo adhesive layers are pressurized with a mail gaper (MS-900: manufactured by Dai Nippon Printing Co., Ltd.) with the setting of the roll gap 14. After pseudo-adhering and allowing to stand for 5 minutes, the peel strength was measured by peeling from the end in the length direction at 500 mm / min using a T-type peel tester. Ten sets of samples were prepared and tested for each example and each comparative example. Evaluation is good (◯) for optimal values of 150 g / 5 cm to 250 g / 5 cm, acceptable values of 100 g / 5 cm to 149 g / 5 cm and 251 g / 5 cm to 300 g / 5 cm are acceptable (Δ), and other than the above (impossible) X).

<Cost>
It was examined whether the raw material and the manufacturing cost were high or low compared with the conventional character pattern printing (Comparative Example 3). Evaluation was evaluated as good (◯) for those with a lower cost than conventional character pattern printing, acceptable (Δ) for those with almost the same cost, and impossible (×) for those with higher costs.

  As shown in Table 1, the test results for the examples of the present invention were evaluated as ○ or ◎ for all the test items. became. From this test result, it was shown that the pseudo-adhesive paper of the present invention is excellent in peelability and concealment and can be manufactured at a lower cost than the conventional example.

  The pseudo-adhesive paper of the present invention is used as a pseudo-adhesive paper suitable for a confidential postcard, a folding pseudo-adhesive paper, an overlay pseudo-adhesive paper, other confidential information-hiding paper, a confidential postcard, a confidential envelope, and the like. be able to.

Claims (2)

A pseudo-adhesive paper having a pseudo-adhesive layer that pseudo-adhesively peels off when a predetermined condition is given without adhering to at least one side of the front and back surfaces of the base paper in a normal state,
The base paper has a laminated structure having three or more paper layers, and the front side paper is between a front side paper layer located on the most front side and a back side paper layer located on the back side. A pseudo-adhesive paper characterized in that an intermediate paper layer having a ground color different from the ground color of at least one of the paper layer and the back side paper layer is provided. A pseudo-adhesive paper having a pseudo-adhesive layer that pseudo-adhesively peels off when a predetermined condition is given without adhering to at least one side of the front and back surfaces of the base paper in a normal state,
The base paper has a laminated structure having two or more paper layers, and the ground color of the top paper side layer located on the top surface side or the back side paper layer located on the back side is different from each other. A pseudo-adhesive paper characterized by that.