JP2000144066A - Release paper and pressure sensitive adhesive sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a release paper excellent in smoothness of the surface of a label and in printed finish and regenerable to be reused by forming a varnish layer comprising a paper base material and a varnish layer formed by coating a varnish thereon and a release agent layer formed by coating a releasing agent on the varnish layer. SOLUTION: A release paper comprises a paper base material such as a woodfree paper or the like, a varnish layer formed by coating 0.3-15 g/m2 of a varnish or a gloss varnish and a releasing agent layer formed by coating 0.2-5.0 g/m2 of a releasing agent on the varnish layer. This release paper is employed to obtain an adhesive sheet by laminating a pressure sensitive adhesive and a surface base material on the releasing agent layer. As the releasing agent, there can be exemplified silicone resins, fluororesins, amino alkyd resins, polyester resins and the like, which are coated as an emulsion or as a solvent- containing or solvent-free coating liquid. As the surface base material are employed papers such as coat papers, art papers or the like; films such as polyolefins, polyesters or the like; metal foils; laminated base materials; metalized sheets obtained by metalizing aluminum or the like on these base materials; or the like.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a release paper.
The present invention also relates to an adhesive sheet using a transparent film as a surface substrate.

[0002]

2. Description of the Related Art Conventionally, pressure-sensitive adhesive labels, pressure-sensitive adhesive seals, pressure-sensitive adhesive tapes and the like (hereinafter collectively referred to as pressure-sensitive adhesive sheets).
As the release paper used for the above, a laminate base material (for example, polyethylene laminate paper) obtained by laminating a polyolefin or the like on paper, or a paper base material such as glassine paper formed with a release agent layer is used. Further, as a release paper in the case of an adhesive sheet using a plastic film as a surface base material, a release paper layer formed of a polyolefin laminated substrate or a plastic film is used.

[0003]

However, in the case of a release paper using a laminated base material, the resin such as polyethylene forms a strong continuous film, and since it is insoluble in water, the base material is recovered again. However, it cannot be recycled in the papermaking process, which is a major problem in industrial waste treatment today. On the other hand, release paper using a plastic film as a base material is generally expensive and has a problem that a special technique is required for controlling tension during the production of the pressure-sensitive adhesive sheet. A release paper using a paper base is preferable because it can be recycled. However, when a plastic film is used as the surface base, the conventional release paper has a surface roughness of the release paper (plastic film). ), Which impairs the smoothness of the label surface and the finish of printing.

[0004]

Means for Solving the Problems The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, have adopted a configuration in which a varnish layer and a release agent layer are provided on one side of a paper base material. It has been found that a highly smooth release paper can be obtained, and that even when a plastic film is used as the surface base material, a release paper which is excellent in the smoothness of the label surface and the finished print and which can be recycled can be obtained. The present invention is a release paper characterized in that a paper substrate is provided with a varnish layer coated with a varnish, and a release agent layer coated with a release agent on the varnish layer.

Further, they have found that when a transparent film is used as a surface substrate, a high gloss adhesive sheet can be obtained by combining it with a glossy varnish. The present invention provides a paper substrate, a varnish layer coated with a gloss varnish, a release paper provided with a release agent layer coated with a release agent on the varnish layer, a release agent layer on the release paper, an adhesive layer, It is an adhesive sheet characterized by laminating a transparent film.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Examples of the paper substrate include high-quality paper containing cellulose pulp as a main component, coated paper, art paper, cast coated paper, glassine paper and the like. In order to smooth the surface of the paper base material, a smoothing treatment can be performed using a super calender or the like.

As the varnish applied on the paper substrate, varnish used for printing can be used. In particular, glossy varnish (glossy varnish) not only provides a pressure-sensitive adhesive sheet having a smooth surface substrate, but also a highly glossy release paper that has never been obtained before. The coating amount of the varnish is 0.3 to 15 g / m ^2.
Is preferred, and 3 to 12 g / m ² is more preferred. If the amount is less than 0.3 g / m ² , sufficient gloss cannot be obtained, and in some cases, it is not possible to prevent the release agent from seeping into the paper base material, which may impair the function of the release agent layer. 15g /
If such exceeding m ^2, cost is increased.

The release agent applied on the varnish layer includes a silicone resin, a fluorine resin, an aminoalkyd resin, a polyester resin and the like, and is formed as an emulsion or a solvent-type or non-solvent-type coating liquid. In addition, a release agent can be selected from a light release type, a medium release type, a heavy release type and the like according to the purpose of the final adhesive label. The coating amount of the release agent is 0.2 to 5.0 g / m.
^{About 2} . When it is less than 0.2 g / m ² , the function as a release agent layer cannot be sufficiently obtained, and when it exceeds 5.0 g / m ² , the cost becomes high.

As a method of applying the varnish layer and the release agent layer, known coating apparatuses such as a gravure coater, a bar coater, an air knife coater, and a multi-stage roll coater can be appropriately used.

The release paper thus obtained can be used as an adhesive sheet by laminating an adhesive and a surface substrate on a release agent layer. For example, it can be manufactured by a method of applying a pressure-sensitive adhesive layer on a release agent layer of a release paper and then laminating a surface base material, or a method of applying an adhesive layer to the surface base material and thereafter bonding a release agent layer of release paper.

As the pressure-sensitive adhesive constituting the pressure-sensitive adhesive sheet, a known pressure-sensitive adhesive such as an acrylic pressure-sensitive adhesive or a rubber-based pressure-sensitive adhesive can be used. The adhesive strength of the adhesive is preferably selected according to the intended use.

As the surface substrate, papers such as high quality paper, coated paper, art paper, cast coated paper, polyolefin,
Films such as polyester or synthetic papers, metal foil,
A laminated substrate obtained by appropriately laminating these substrates, a metal-deposited sheet obtained by vapor-depositing aluminum or the like on these substrates, and a recording layer such as a heat-sensitive recording layer, a thermal transfer recording receiving layer, and an ink jet recording layer were formed on these substrates. A recording sheet or the like can be used as appropriate.

In particular, since the release paper of the present invention can form a highly smooth release agent layer surface, cast coated paper, films, etc.
Synthetic papers and metal-deposited sheets are preferable because the smoothness and glossiness of the surface do not decrease even when subjected to adhesive processing. Further, even if the recording sheet is subjected to an adhesive process, it is preferable because there is no influence on the recording layer such as a roughened surface.

When a transparent film is used as the surface substrate, the high gloss of the release paper appears through the surface substrate to the surface of the pressure-sensitive adhesive sheet, so that an unprecedented high-gloss pressure-sensitive adhesive sheet can be obtained. In this case, the pressure-sensitive adhesive layer is preferably a colorless and nearly transparent pressure-sensitive adhesive, and more preferably a colorless and transparent pressure-sensitive adhesive. In addition, the use of an acrylic pressure-sensitive adhesive is more preferable because the rubber-based pressure-sensitive adhesive may cause discoloration.

[0015]

The present invention will be described in more detail with reference to the following examples, but the scope of the present invention is not limited by these examples. Unless otherwise specified, “parts” and “%” in the examples indicate “parts by weight” and “% by weight”, respectively.

Example 1 (Formation of varnish layer) A glossy varnish (trade name: FDPCA80) was coated on one side of a coated paper having a basis weight of 127.9 g / m ² (trade name: OK Topcoat N, manufactured by Oji Paper Co., Ltd.). Varnish, manufactured by Toyo Ink Mfg. Co., Ltd.) was applied using a gravure coater so that the weight after drying was 12 g / m ² to form a varnish layer. (Manufacture of release paper) Addition-reaction type solvent-free silicone (trade name: KNS-320, manufactured by Shin-Etsu Chemical Co., Ltd.) 1 on the varnish layer
A coating liquid containing 00 parts and 2 parts of a platinum catalyst (trade name: PL-56, manufactured by Shin-Etsu Chemical Co., Ltd.) is applied by a gravure coater so as to have a coating weight of 1.0 g / m ² and cured with hot air to obtain a release paper. Was.

Example 2 (Formation of varnish layer) A gloss varnish (trade name: AQUAACE BMOP varnish reinforced) on one side of an art paper (trade name: Kanto, manufactured by Oji Paper Co., Ltd.) having a basis weight of 84.9 g / m ² , Manufactured by Toyo Ink Mfg. Co., Ltd.) with a gravure coater so that the weight after drying was 8 g / m ² to form a varnish layer. (Production of Release Paper) A release agent layer was formed on the varnish layer in the same manner as in Example 1 to obtain a release paper.

Example 3 (Formation of varnish layer) Glossy varnish (trade name: FDPCA197S varnish, manufactured by Toyo Ink Mfg. Co., Ltd.) was dried on a gravure coater over the entire area of one side of glassine paper having a basis weight of 74 g / m ² . Was applied to 3 g / m ² to form a varnish layer. (Production of Release Paper) A release agent layer was formed on the varnish layer in the same manner as in Example 1 to obtain a release paper.

Comparative Example 1 In Example 1, a release agent layer was formed directly on coated paper without forming a varnish layer to obtain a release paper.

Comparative Example 2 In Example 2, a release agent layer was formed directly on art paper without forming a varnish layer to obtain a release paper.

Comparative Example 3 In Example 3, a release agent layer was formed directly on glassine paper without forming a varnish layer to obtain a release paper.

[Evaluation] Regarding the obtained release paper, the glossiness (75 ° reflection value) and the smoothness (JAPAN) of the release agent layer surface were measured.
TAPPI paper pulp test method No. Oken type smoothness described in No. 5) was measured. The peelability, defibration property and smoothness of the label surface were evaluated according to the following criteria. The results are shown in Table 1.

"Releasability" An acrylic emulsion pressure-sensitive adhesive (trade name: Nicazole L-145, manufactured by Nippon Carbide) was applied on the above-mentioned release paper with a reverse roll coater so that the dry weight became 25 g / m ² , Drying was performed with a hot air dryer, and high-quality paper having a basis weight of 64 g / m ² was attached to obtain an adhesive paper. Then, the ease of peeling off the high-quality paper was evaluated according to the following criteria. ◎: Peeled smoothly ○: Peeled but slightly heavy △: Peeled but resistant ×: Paper tear

"Disintegration property" The disintegration property of the release paper was evaluated by observing the dispersion state of the sample components together with the disintegration treatment using a standard disintegrator. The coated paper level was evaluated as ○.

"Smoothness of label surface" Acrylic emulsion adhesive (trade name: Nicazole L-1) on the release paper
45, manufactured by Nippon Carbide Co.) with a reverse roll coater so that the dry weight becomes 25 g / m ² ,
And a 50 μm thick PET film (trade name: PET S50, manufactured by Teijin) was adhered to obtain an adhesive sheet. The smoothness of the PET film surface was observed and evaluated according to the following criteria. ：: Smooth surface △: Slight unevenness (bumpiness) of release paper slightly appeared on surface ×: Slight unevenness (bumpy) of release paper remarkably appeared on surface

[0026]

[Table 1]

Comparing Example 1 with Comparative Example 1, Example 2 with Comparative Example 2, and Example 3 with Comparative Example 3, the smoothness and glossiness of each example are dramatically improved. Although the release paper using the glassine paper of Example 3 has a low gloss value due to the low opacity of the glassine paper, it is visually similar to the other examples. I have. As for the releasability, it is understood that the release paper of each example is excellent because the varnish layer prevents the release agent from seeping into the paper. As for the disintegration, since lamination of polyethylene or the like is not performed, any of them is possible, and even if it is mixed with general waste paper, it can be recycled. It can be seen that the smoothness of the label surface is excellent when the release paper of each embodiment is used, since unevenness or the like does not appear on the surface.

[0028]

The release paper of the present invention is an extremely practical release paper that can be sufficiently reused as recycled pulp. Moreover, it is an unprecedented release paper and an adhesive sheet having a high gloss.

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Hakuhide Kazama 291 Kunimoto, Fukuroi City, Shizuoka Prefecture Inside Shinomura Chemical Industry Co., Ltd. (72) Inventor Nobuo Nishizawa 12-7 Nihonbashi Kabutocho, Chuo-ku, Tokyo Inside Shinomra Chemical Industry Co., Ltd. 4J004 AA05 AA10 AB01 CA02 CA04 CA06 CA08 CB02 CC02 CD01 DA01 DA02 DA03 DA04 DB02 DB04 FA01

Claims (2)

[Claims] A release paper comprising a paper substrate and a varnish layer coated with a varnish, and a release agent layer coated with a release agent on the varnish layer. 2. A release paper having a varnish layer coated with a glossy varnish on a paper substrate, a release agent layer coated with a release agent on the varnish layer, and an adhesive layer on the release agent layer of the release paper. And a pressure-sensitive adhesive sheet obtained by laminating a transparent film.