JPH0151512B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to an adhesive sheet for title display labels. In particular, recording of video cassettes, audio cassettes, floppy disks, etc.
The purpose is to provide an adhesive sheet for title display labels that has characteristics such as water resistance, weather resistance, concealability, writability, and printability required for title display labels for recording, writing, etc. be. In recent years, with the spread of VTRs, the development of audio equipment, and the shift to OA for office processing, the production volume of video cassettes, audio cassettes, and floppy disks has reached a considerable amount, and is expected to increase further in the future. ing. Title display labels are attached to these video cassettes and the like to display the contents of recordings, audio recordings, writings, etc. A spare title display label is prepared so that the title display label can be replaced whenever the content of recording, audio recording, writing, etc. changes. However, video cassettes etc.
Not only for general households but also for outdoor use by news organizations,
In order to be used under harsh conditions such as in stores and in cars, title display labels have many properties such as water resistance, weather resistance, concealability, writability, printability, and ease of handling when repositioning. are required to do so. Conventionally, title display labels for video cassettes, etc. have been made using adhesive sheets whose surface base is made of plastic film such as polyester film, vinyl chloride resin film, synthetic paper, etc., or adhesive sheets whose surface base is paper impregnated with synthetic resin. It is provided. In addition, as a general-purpose type, adhesive sheets whose surface base material is paper such as high-quality paper or art coated paper are available. However, adhesive sheets whose surface is made of plastic film or the like have disadvantages in that they have poor writing properties with writing instruments such as pencils, fountain pens, and ballpoint pens, and are expensive due to high material costs. This problem is also seen in pressure-sensitive adhesive sheets that use resin-impregnated paper as a surface base material, and they have the same disadvantage of being expensive due to poor productivity. Adhesive sheets whose surface material is paper such as high-quality paper or art-coated paper can be obtained at low cost, but they have poor water resistance, especially when exposed to low temperatures, high humidity, or high humidity. , has serious drawbacks such as lifting, wrinkling, tearing, and peeling. Additionally, because the paper is weak, it may tear when reattached when changing the content, and adhesive residue may remain. Therefore, there is a need on the market for adhesive sheets whose surface is paper and which simultaneously has many of the characteristics required for title display labels such as video cassettes, such as water resistance, weather resistance, concealability, writability, and printability. Although this has been requested, the reality is that there is still nothing that satisfies it. In order to solve the problems of the conventional pressure-sensitive adhesive sheets described above, the present invention has been made through intensive research, and the present invention has been completed by successfully obtaining a satisfactory pressure-sensitive adhesive sheet using paper as the surface base material. That is, the present invention provides an undercoat layer that is formed by coating the surface of a base paper with excellent water resistance, interlayer strength, and flexibility with a water-based pigment paint containing a carboxy-modified latex and a water-resistant agent and having a high adhesive composition ratio. A title display label characterized in that a removable adhesive layer is provided on the back side of a surface base material that is coated with a water-based pigment paint containing pigment and adhesive as main components and provided with an overcoat layer. It is an adhesive sheet. Hereinafter, technical matters of the present invention will be explained in detail. Currently, the suitability of adhesive sheets for use as title display labels for video cassettes and the like is determined by pasting title display labels on video cassette frames and cassette cases, and performing the following cycle test.
In other words, "-20℃ x 4 hours → 40℃ x 95% RH x
A cycle test of 4 hours → 70℃ x 40 hours was repeated 5 times. When an adhesive sheet whose surface is made of paper such as high-quality paper or art-coated paper is applied to a video cassette frame or video cassette case and subjected to a cycle test, the adhesive sheet that was initially adhered normally may lift or wrinkle. , peeling, etc. occur, and as a result, the surface base paper is torn during re-adhesion, so it has the disadvantage that it cannot be used at all for title display labels. Therefore, the present invention succeeded in solving the problems of the pressure-sensitive adhesive sheet for title display labels by adding innovation to the surface base material. First, since it is not possible to obtain satisfactory results with the various types of base paper and high-quality paper that are normally made, in the present invention, the base paper used as the surface base material is water resistant and has strong interlaminar strength. It has weather resistance that can withstand the usage environment, excellent dimensional stability, and appropriate flexibility for the purpose. In other words, when making base paper, we take into account the combination of water-resistant agents and paper strength agents, and size-press treatment using water-soluble resin from the viewpoint of suitability for coating and pasting with water-based pigment paints in the subsequent process. We also try to provide flexibility. As the paper strength enhancer used in the base paper, corn starch, cationically modified starch, modified polyacrylamide, etc. can be used. Water-resistant agents include urea formalin resin, melamine formalin resin, polyamine,
Epoxy resin, dialdehyde starch, etc.
Further, as the size press liquid for imparting flexibility, a water-soluble resin solution such as a water-soluble acrylic resin or polyacrylamide is used. The base paper produced in this way has the water resistance, weather resistance, and
A pigment coating layer is provided to obtain hiding properties, writability, printability, etc. At that time, since these characteristics cannot be obtained with a single coating, a water-based pigment coating that provides hiding properties, writability, and printability is provided by interposing a water-resistant undercoat layer. We are trying to get all the characteristics. That is, an undercoat layer is provided on the base paper by coating it with a water-based pigment paint containing a carboxy-modified latex and a waterproofing agent and having a high blending ratio of adhesive. Water resistance is imparted to the undercoat layer by the crosslinking reaction between the carboxy-modified latex and the water-resistant agent and by the high blending ratio of the adhesive. Water-based pigment paints with a high blending ratio of adhesive that provide water-resistant effects have a ratio of 25 parts of adhesive to 100 parts of pigment.
~100 parts, preferably 30 to 80 parts. In the adhesive having a high blending ratio, the carboxy-modified latex is blended in an amount of 5 to 80 parts, preferably 10 to 70 parts. Other adhesives that can be used include oxidized starch, casein, SBR, MBR, NBR, acrylic, and other latexes used for coating paper. The waterproofing agent is blended in an amount of 1 to 30 parts, preferably 2 to 25 parts, per 100 parts of the pigment, and may be one that is used in making base paper. As the pigment, those used for paper coating such as kaolin, aluminum hydroxide, and sachin white can be used. The top coat layer, which is provided through a water-resistant undercoat layer, is coated with a water-based pigment paint whose main components are pigments and adhesives in order to provide weather resistance, concealability, writability, printability, etc. It will be done. The pigments used in the overcoat layer are mainly calcium carbonate and titanium oxide, and other pigments used in paper coatings, such as kaolin, aluminum hydroxide, and satin white, can be used. As the adhesive, water-soluble resins such as starch, casein, polyvinyl alcohol, and various latexes can be used. Next, the surface base material obtained in this way has strong adhesive strength on its back side to prevent it from lifting, wrinkling, tearing, or peeling even after cycling tests at low temperatures, high temperatures, and high humidity. The adhesive sheet for title display labels of the present invention is provided with a removable adhesive layer that does not leave adhesive residue, tear the surface substrate, or contaminate the surface of the adherend when removed. It will be done. The adhesive strength is between 500 and 2000g/25mm, and removable adhesives that can achieve this kind of adhesive strength are:
Acrylic adhesive can be selectively used.
The removable adhesive layer is protected by appropriately disposing a release paper as necessary. The pressure-sensitive adhesive sheet for title display labels of the present invention obtained in this way has the necessary characteristics by being devised so that each part constituting the base paper, undercoat layer, topcoat layer, and surface base material is provided with various necessary characteristics. It can have all the characteristics.
In other words, a base paper with excellent water resistance, interlayer strength, and flexibility is used, and a surface base material is provided with a water-resistant undercoat layer and a topcoat layer with weather resistance, concealability, writability, and printability. By processing it with a releasable adhesive, it was possible to obtain an adhesive sheet for title display labels that had all the necessary properties, and succeeded in eliminating all the drawbacks of conventional products. Further, the present invention will be explained by examples. Example 1 Base paper composition Parts by weight LBKP 90 NBKP 10 Filler 15 Paper strength agent 1.5 Water resistance agent 3 Sizing agent 0.7 Band PH4.5 A base paper with a basis weight of 60 g/m ² was made with the above base paper composition, and polyacrylamide 7 % solution was used for size press treatment. The base paper thus obtained was coated with an aqueous pigment paint having the composition shown below to provide an undercoat layer and a topcoat layer to obtain a surface base material. Composition for undercoat layer Parts by weight Kaolin 100 Sodium tripolyphosphate 0.3 Oxidized starch 5 Carboxy-modified SBR latex 30 Melamine-formalin resin 3 Solid content 40% Coating amount 10g/m ² Composition for topcoat layer Parts by weight Kaolin 50 Calcium carbonate 20 Rutile Type titanium oxide 30 Sodium tripolyphosphate 0.3 Casein 10 SBR latex 14 Solid content 40% Coating amount 15g ^/ m Agent 3
A pressure-sensitive adhesive sheet for a title display label of the present invention was obtained by applying 25 g/m ² of the adhesive layer and disposing a release paper. Example 2 Base paper composition Parts by weight LBKP 90 NBKP 10 Filler 0 Paper strength agent 1.5 Water resistance agent 3 Sizing agent 0.7 Band PH4.5 A base paper was obtained in the same manner as in Example 1 with the above base paper composition. This base paper was coated with an aqueous pigment paint having the following composition to form an undercoat layer and a topcoat layer, thereby obtaining a surface base material. Composition for undercoat layer Parts by weight Kaolin 100 Sodium tripolyphosphate 0.3 Oxidized starch 10 Carboxy-modified SBR latex 70 Melamine-formalin resin 8 Solid content 43% Coating amount 15g/m Composition for ^second topcoat layer Parts by weight Kaolin 30 Calcium carbonate 30 Rutile Type titanium oxide 40 Sodium tripolyphosphate 0.3 Casein 5 SBR latex 17 Solid content 40% Coating amount 10 g/m ² On the back side of the front base material, acrylic two-component adhesive (Toyo Ink adhesive Olivine 100 parts + hardened) Agent 3
A pressure-sensitive adhesive sheet for a title display label of the present invention was obtained by applying 30 g/m ² of 30 parts + 30 parts of toluene to form an adhesive layer and disposing a release paper. Comparative Example 1 Base paper composition Parts by weight LBKP 90 NBKP 10 Filler 0 Paper strength agent 0.1 Water resistance agent 1 Sizing agent 0.7 Band PH4.5 A base paper with a basis weight of 60 g/m ² was made with the above base paper composition, and polyacrylamide 3 % solution was used for size press treatment. The base paper thus obtained was coated with an aqueous pigment paint having the following composition to form a pigment layer, thereby obtaining a surface base material for comparison. Composition Parts by weight Kaolin 100 Sodium tripolyphosphate 0.3 Casein 7 SBR latex 13 Solid content 40 Coating amount 20 g/m ² An adhesive layer was provided on the back side of this comparison surface base material in the same manner as in Example 1 and peeled off. A comparative adhesive sheet was obtained by disposing paper. Comparative Example 2 Base paper composition Parts by weight LBKP 90 NBKP 10 Filler 0 Paper strength enhancer 0.1 Sizing agent 0.7 Band PH4.5 A base paper of 60 g/m ² was made with the above base paper composition,
Size press treatment was performed using a 3% polyacrylamide solution. Comparative Example 1 was used for the base paper thus obtained.
In the same manner as above, a 25 g/m ² coated pigment layer was provided to obtain a surface base material for comparison. A pressure-sensitive adhesive layer was provided on the back side of this comparative front base material in the same manner as in Example 2, and a release paper was disposed thereon to obtain a comparative pressure-sensitive adhesive sheet. Comparative Example 3 The base paper obtained in Comparative Example 1 was coated with 20 g/m ² of an aqueous pigment paint having the composition for the undercoat layer of Example 1 to form a pigment layer, thereby obtaining a surface base material for comparison. A pressure-sensitive adhesive layer was provided on the back side of this comparative surface base material in the same manner as in Example 1 to obtain a comparative pressure-sensitive adhesive sheet. A quality test was conducted on the pressure-sensitive adhesive sheets for title display labels obtained in each Example and Comparative Example.
The results of the quality tests are shown in the table below, and the adhesive sheet for title display labels of the present invention has sufficient suitability for title display labels even when paper is used as the surface base material, and is satisfactory. It turns out that you are getting something.

[Table] ◎: Excellent ○: Good △: Possible ×: Not possible

Claims (1)

[Claims] 1 The surface of base paper with excellent water resistance, interlayer strength, and flexibility is coated with a water-based pigment paint that contains carboxy-modified latex and a water-resistant agent and has a high adhesive composition ratio. A pressure-sensitive adhesive sheet for a title display label, characterized in that a removable adhesive layer is provided on the back side of a surface base material formed by coating a water-based pigment paint containing an adhesive as a main component and providing an overcoat layer.