JPH0689309B2 - Concealable adhesive tape or sheet - Google Patents

Description

TECHNICAL FIELD The present invention relates to a concealable pressure-sensitive adhesive tape or sheet. For more details, the fixed price displayed on the product, characters such as copy manuscripts,
The present invention relates to a concealable pressure-sensitive adhesive tape or a concealable pressure-sensitive adhesive sheet which can be pasted on the image to correct the image and conceal them to display a new fixed price or the like.

[Prior art and problems]

Adhesive tapes or sheets are used in a wide range of applications as labels, stickers, stickers and the like. In particular, price labels for products are used in supermarkets, chain stores, department stores, retail stores, pharmacies, etc. nationwide.
When the list price of a product is revised, it is generally done by overlaying a modified concealing adhesive tape or sheet. Conventionally used high-quality paper, fine-quality lightweight coated paper, medium-quality paper, medium-quality lightweight coated paper, etc. as the base material of the modified pressure-sensitive adhesive tape and the surface material of the pressure-sensitive adhesive sheet. is there.

Some of them have excellent concealing properties and use a composite sheet of paper and aluminum foil, or aluminum vapor-deposited paper, but their use is limited in terms of price. In addition, a colored adhesive tape or sheet in which a large amount of a coloring pigment is added to an adhesive to impart opacity is known, but it has a drawback that it is difficult to control the adhesive strength (Japanese Patent Publication No. 47-8720).

[Means for solving problems]

The present inventor has conducted extensive studies on the relationship between the limit of opacity and the concealing property that can be achieved with the same basis weight as that of fine paper lightweight coated paper, and as a result, the clay coated layer on the back surface of the lightweight coated paper, The opacity of the back side colored paper replaced with the colored layer is 95
It was found that a sufficient hiding property can be obtained by adjusting the content to be at least%.

Further, as a method of applying both front and back coating layers, an on-machine coater such as a gate roll coater is used, and coating liquids having different hues are simultaneously applied to the front and back of the base paper to form a concealable pressure-sensitive adhesive tape or sheet. The inventors have found that the production of a backside colored paper that can be used as a paper base material (front surface base material) can be made in-line, and reached the present invention.

[Structure and Action of Invention]

The present invention provides a pressure-sensitive adhesive tape composed of a paper base material, a pressure-sensitive adhesive layer and a back surface treatment agent layer or a surface paper base material, a pressure-sensitive adhesive sheet composed of a pressure-sensitive adhesive layer and release paper, wherein The material has a white hiding surface coating layer mainly composed of a white pigment and a film-forming polymer on the surface of the base paper, and one hue selected from blue, brown, purple and black on the back surface. A backside colored paper having a basis weight of 70 g / m ² or less having a colored concealing layer which is colored, the opacity measured by facing the light source to the surface coated layer surface is 97% or more, and the white surface. 82%
The present invention relates to the concealable pressure-sensitive adhesive tape or sheet, wherein the pressure-sensitive adhesive layer is formed on the back surface side of the paper base material or front surface paper base material.

Hereinafter, the configuration of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a cross-sectional view of a structural example of a concealable pressure-sensitive adhesive tape, FIG. 2 is a cross-sectional view of a structural example of a concealable pressure-sensitive adhesive sheet, and FIG. 3 is an explanatory diagram showing an arrangement state of gate roll coaters.

The concealable pressure-sensitive adhesive tape is composed of a paper substrate 1, a pressure-sensitive adhesive layer 6, and a back surface treatment agent layer 7. The concealable pressure-sensitive adhesive sheet is composed of a surface paper substrate 2, a pressure-sensitive adhesive layer 6, and a release paper 8.
The paper base material 1 and the front surface paper base material 2 have substantially the same action and effect with different sectional structures.

In FIG. 1, on the surface of the base paper 3, clay, kaolin,
A surface coating layer 4 is formed by applying a coating liquid containing a white pigment such as titanium dioxide and a binder as a solid content in an amount of 2 to 6 g / m ² . As the binder, a natural or synthetic film-forming polymer substance such as starch or polyvinyl alcohol is used. The colored layer 5a is formed by coating a coloring agent in the coating liquid for the surface coating layer. The high hiding power required by the present invention is understood as the sum of the opacity of these three-layer constituent components such as fiber and white pigment and the light absorptivity of the colorant. The present inventors have in the embodiment 1 described later, the surface coating layer and a coverage of from 3.5 g / m ^2, a coated amount of the coloring layers with dyes of violet and 3.5 g / m ² as a colorant The backside colored paper thus obtained had a basis weight of 69.0 g / m ² , an opacity of 98.7% and a whiteness of 86%. When the colored layer of this product was bleached and decolorized, the opacity was measured and found to be 92%. Since the opacity of the base paper was 87.1%, the above fact is the same as the fact that the increase in opacity due to the white pigment being coated on the front and back sides of the base paper at a total of 7 g / m ² is about 5%. As described above, the effect of further increasing the opacity by 6% or more was obtained by using a very small amount of dye of 0.02 g / m ² . Opacity requires that the value measured according to JIS P8138 with the surface of the surface coating layer facing the light source is 95% or higher. 97%
The above is preferable. In the present invention, the photovolt photoelectric reflectometer 67
Type 0 was used. By the way, when the measurement is performed with the colored layer surface facing the light source, the light absorption is unevenly performed, resulting in a large error. By selecting the hue of the colored layer, it is possible to obtain 100% that is comparable to the conventional product using aluminum foil, but 98% or more is often used. The hue of the colored layer is not limited, but when the present inventor prepared a backside colored paper using various dyes under constant conditions and measured the opacity, each of red, green, blue, brown, purple and black was obtained. The systematic colors were 95% or more, and in particular the blue, brown, purple, and black systematic colors were 99 to 100%. Dyes as colorants,
It does not matter whether the pigment is used or not, but it is preferable to use a dye from the viewpoint that broke and decolorization of broke generated in the paper manufacturing process can be recovered and used. The amount of colorant of the colored layer is carried out in the range of ^{0.01g / m 2 ~1.0g / m 2} , 0.01g / m 2 ~0 especially in the case of a dye.
A range of 05g / m ² is sufficient.

The whiteness of the surface coating layer is required to be 80% or more, particularly 82% or more in view of printability. The whiteness was measured using a Photovolt Photoelectric Reflectometer 670 type according to JIS P8123. When the colored layer is applied, the backing of the colored layer (show thr
ough), and whiteness is likely to be significantly reduced due to bleeding. As a means for preventing the decrease in whiteness, increasing the internal filler of the base paper, increasing the sizing degree, increasing the air permeability, and the like are conceivable. By using a gate roll type coater which can be applied with high viscosity, it is possible to substantially suppress the decrease in whiteness of the surface coating layer. The gate roll coater is composed of 6 rolls as illustrated in Fig. 3. Using the outer rolls 13 and 16 and the inner rolls 12 and 15 that rotate in the normal direction, the coating liquid is applied between the rolls while applying the nip pressure. It is a coater of the type that is transferred and coated on both sides of the base paper simultaneously with the applicator rolls 11 and 14 of the final roll, and is usually installed in the drying section of the paper machine.

In the practice of the present invention, the coating liquid for the surface coating layer is added between the nip between the rolls 12 and 13, and the coating liquid for the colored layer is added between the nip between the rolls 15 and 16.

It should be noted that FIG. 2b shows a coloring layer composed mainly of a natural or synthetic film-forming polymer substance and containing a coloring agent added to a clear coating liquid in which a white pigment is not substantially mixed. 5a can be replaced, and vice versa. The coating amount is 0.2 to 4 g / m ² . However, since the colorant is dispersed or adsorbed in the white pigment, the 5a is more preferable because it has an effect of suppressing back wandering, bleeding, and the like.

The backside colored paper thus produced is smoothed with a super calendar or the like, and then used as the paper base 1 of the concealable pressure-sensitive adhesive tape and the surface base 2 of the concealable pressure-sensitive adhesive sheet. A back surface treatment agent layer 7 is coated on the paper base material 1 in order to impart releasability.
As the back surface treating agent, for example, a commercially available silicone release agent having improved printability can be used.

Then, after coating the pressure-sensitive adhesive layer 6 on the back surface side of the paper substrate 1 using various known solution-type or emulsion-type pressure-sensitive adhesives such as rubber-based, acrylic-based, vinyl ether-based, etc. Can be finished. In the concealable pressure-sensitive adhesive sheet, the back side colored paper 2 is used as the front surface base material, and the release paper is attached to the back side via the pressure-sensitive adhesive layer 6. In addition, it is optional to apply a sealing material to the paper base material or the surface paper base material by a known technique, or to bond and reinforce the film.

[Example 1] In order to produce the concealable pressure-sensitive adhesive tape shown in Fig. 1, a backside colored paper having a purple backside was made by the following procedure.

90 parts of LBK, 10 parts of NBK mixed pulp was beaten to a beating degree of 60 ° SR, and calcium carbonate filler, sizing agent, and
A furnish was prepared by adding a paper strength enhancer and the like. The basis weight of the base paper obtained by adjusting the paper machine to the specified conditions and making it 61.9
5g / m ² , thickness 94.1μm, opacity 87.1%, whiteness 85.5%
Met. The base paper was coated on both sides with a gate roll coater installed in the drying section of the paper machine, and the coating solutions shown below were prepared.

Both the front and back coating solutions were diluted to a solids concentration of 58%, and the front and back coatings were applied simultaneously with a gate roll coater. Coating amount is about 3.5 g / m ²
Met. The amount of dye in the colored layer is calculated to be 0.02 g / m ² .
Basis weight of back side colored paper obtained by applying super calendar 69.0
g / m ² , thickness 80.0 μm, opacity 98.7%, whiteness 86%, surface smoothness 80 seconds / 10 ml. When the colored surface was superposed on the solid printed surface of the black ink and visually observed, the solid printed surface was completely hidden. The whiteness did not decrease and was at the same level as the base paper.

Using this as a paper base material, a backside treatment agent layer coated with a commercially available silicone release agent with improved printability at 5 g / m ² was provided, and an acrylic adhesive was applied to the backside to a thickness of 25 μm. The concealable pressure-sensitive adhesive tape obtained in this way could be used for the concealment of the fixed price of products.

[Example 2] In order to manufacture the concealable pressure-sensitive adhesive sheet shown in Fig. 2, a backside colored paper coated with a clear coating liquid containing a purple dye on the backside was prepared in the following order.

A furnish was prepared in the same manner as in Example 1. The basis weight of the set base paper is 60.38 g / m ² , the thickness is 91.7 μm, and the opacity is 85.4.
%, The whiteness was 85.5%. The same coating liquid as in Table 1 was used for the surface coating layer. The composition of the coating liquid for the surface coloring layer is as shown in Table 3.

The coating liquid for the front surface coating layer was diluted to a solid content concentration of 58%, and the coating liquid for the back surface coloring layer was adjusted to a concentration of 20%, and the front and back surfaces were coated simultaneously.

The front surface coating amount was 3.68 g / m ² and the back surface coating amount was 0.34 g / m ² . Then smooth with a super calendar and weigh 6
4.4g / m ² , thickness 78.4μm, opacity 98.4%, whiteness 85.0
%, Surface smoothness 83 seconds / 10 ml backside colored paper was manufactured. The amount of dye in the colored layer is calculated to be about 0.02 g / m ² . The whiteness did not decrease and was at the same level as the base paper. A commercially available release paper was coated with the pressure-sensitive adhesive used in Example 1, and this was bonded to the colored surface of the backside coloring paper to obtain a pressure-sensitive adhesive sheet excellent in concealing property.

〔The invention's effect〕

(1) The hiding effect of the present invention is due to the combined action of the opacity of the white pigment and the light absorptivity of the colorant. If the opacity is 95% or more, it can be used for the correction hiding of characters, images and the like.

(2) The coating of the colored layer tends to reduce the whiteness of the base paper, but by adjusting the raw materials and applying the gate roll, it is possible to prevent the deterioration of the whiteness and obtain the desired whiteness, so that the printability is excellent. There is.

(3) Since the paper base material or the surface paper base material is completed in the paper making process, the process can be performed in-line.

(4) The adhesive strength is not adversely affected as compared with the conventional colored adhesive tape in which the adhesive is mixed with a coloring pigment.

[Brief description of drawings]

FIG. 1 is a sectional view showing a structural example of the concealable pressure-sensitive adhesive tape of the present invention, FIG. 2 is a sectional view showing a structural example of the concealable pressure-sensitive adhesive sheet of the present invention, and FIG. 3 shows an arrangement state of gate roll coaters. FIG. 1 ... concealable adhesive tape paper substrate, 2 ... concealable adhesive sheet surface substrate, 3 ... base paper, 4 ... surface coating layer, 5a ...
... Coloring layer formed by adding colorant to white pigment, 5b ...
A coloring layer formed by adding a coloring agent to the clear coating liquid, 6 ...
… Adhesive layer, 7 …… Backside treatment layer, 8 …… Release paper, 11,
14 …… Applicator roll, 12,15 …… Inner roll, 13,16 …… Outer roll.

Continuation of front page Examiner Akiko Ishii (56) References JP 62-141087 (JP, A) Fukui Sho 60-19074 (JP, U)

Claims (2)

[Claims] 1. A pressure-sensitive adhesive tape comprising a paper substrate, a pressure-sensitive adhesive layer and a back surface treatment agent layer or a pressure-sensitive adhesive sheet comprising a surface paper substrate, a pressure-sensitive adhesive layer and a release paper, wherein the paper substrate or the surface paper. The substrate has a white hiding surface coating layer composed mainly of a white pigment and a film-forming polymeric substance on the surface of the base paper,
A backside colored paper having a basis weight of 70 g / m ² or less, which has a colored hiding layer colored in one hue selected from blue, brown, purple and black on the backside, wherein the surface coated layer surface is a light source. The opacity is 97% or more and the whiteness of the surface is 82%.
% Or more, and a concealable pressure-sensitive adhesive tape or sheet is characterized in that an adhesive material layer is formed on the back side of the paper base material or front surface paper base material. 2. The concealable pressure-sensitive adhesive tape or sheet according to claim 1, wherein the colored concealing layer is formed by adding a coloring agent to a paint mainly containing a white pigment and a film-forming polymer substance.