JPS6037840B2 - Adhesive coated product with excellent cutting suitability - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a pressure-sensitive adhesive coated product with excellent cutting suitability.

Adhesive-coated products include adhesive sheets, adhesive tapes, etc., and each is cut and processed to suit the application. For example, when manufacturing adhesive tapes, slitter processing is performed.
Adhesive sheets are processed by slitter cutting, guillotine cutting, die-cutting, etc. according to the purpose, and are also processed into various EO sheets and finished into sheet or roll-shaped adhesive labels, and are used for industrial and household purposes. It is used in a wide variety of applications, including packaging, display, advertising, teaching materials, and entertainment. For such adhesive-coated products, adhesive residue adheres to the slitter cutting blade, guillotine cutting blade, die-cut processing blade, etc. during the processing stage, which reduces the work efficiency of cutting processing and also causes residue to adhere to the blade. The adhesive residue transferred onto the sheet,
This lacks the ability to smoothly feed paper when printing on sheets or pasting labels, and this causes a significant drop in work efficiency. For this reason, in order to prevent adhesive residue from adhering to slitter blades, guillotine blades, die-cutting blades, etc., for example, there is a method of applying a mold release agent such as fatty acid, key oil, silicone oil, etc. to the processing blade. Methods such as Teflon coating on processing blades are currently being implemented, but in the former method,
It is essential to replenish the mold release agent to the processing blade. In the latter case, there is a problem in that since the machining blade is generally polished frequently, Teflon processing must be performed every time it is polished. Another method has been attempted in which a template agent is directly mixed with the adhesive component, but the adhesive performance is improved by mixing a release agent in an amount that can prevent the adhesive from adhering to the processing blade. There is a problem in that the amount of addition is within a range that does not reduce the adhesive performance, and a sufficient template effect cannot be obtained. Under these circumstances, there has been a desire for the development of adhesive-coated products with excellent cutting suitability.

The present inventors have developed an adhesive coated product that continuously forms a release agent film on processing blades such as slitter blades, guillotine blades, die-cutting blades, etc., and prevents adhesive residue from adhering to the processing blades during cutting. As a result of intensive research, the present invention was completed. The structure of the adhesive-coated product of the present invention, which has excellent cutting suitability, is that the adhesive-coated product contains microcapsules whose core material is a release agent to prevent the adhesive from adhering to the processing blade. It is characterized by being coated or contained.

In the above configuration, the adhesive is a commonly used and well-known adhesive, such as synthetic rubber,
The main component of the adhesive is a rubber material such as natural rubber, a polymer or a copolymer such as an acrylic acid alkyl ester, an acrylic acid alkyl ether, or a vinyl ether, and a tackifier, a plasticizer, anti-aging agent,
The target products include water-soluble, organic solvent solution, emulsion, and hot melt types, which are constructed by appropriately blending auxiliary agents such as fillers, thickeners, and antifoaming agents.

The microcapsules contained in such adhesive-coated products must contain a scale agent as a core material to prevent the adhesive from adhering to the processing blade. The template agents used to prevent the adhesive from adhering to the processed blade include higher fatty acids, higher fatty acid conductors, organopolysiloxane compounds, waxes, higher alcohols, tin oil, animal oils, vegetable oils, and silicone oils. etc.

Microcapsules containing such a mold release agent are not particularly limited, but it is desirable to use microcapsules that deform when exposed to external pressure.

The reason is that when the microcapsules are included in the adhesive layer, the microcapsules protrude from the surface of the adhesive layer,
Even if the surface of the adhesive layer becomes scum, the microcapsules deform due to the external pressure they receive when pasted on the adherend, and the extent to which the contact area between the adhesive and the adherend decreases is small. This is because the decrease in adhesive strength can also be reduced.
Preferred wall membrane materials for making such microcapsules include gelatin, casein, polypinyl alcohol, nylon, polyurea, epoxy resin, polyester, and polyurethane. Most mic. Of course, if the deformability of the capsule is not considered, the wall membrane material is not limited to the above-mentioned materials. Mycapsules containing the above-mentioned mold release agent as a core material can be prepared by, for example, ■ Phase separation method from an aqueous solution (
Interfacial polymerization method (which is the most commonly put into practical use and utilizes coacervation of a hydrophilic colloid sol)
Instead of using a completed polymer from the beginning as the wall material of the microcapsules, the monomer or initial condensate that is the first wall forming material is present in the oily liquid to be incorporated, and then the first wall forming material is formed. A second wall-forming substance that can react is dissolved in a polar solvent that is immiscible with the oily liquid, and the first wall-forming substance and a second wall-forming substance are formed at the interface between the oil droplets of the oily liquid and the polar solvent. The substance is polymerized to form a wall film.

) ■ Method by polymerization of monomers in oil droplets (compounds with double bonds such as acrylic compounds, styrene, vinyl acetate, etc. are dissolved in oil droplets, and radical polymerization is carried out using peroxide as a catalyst. Produces an oil-proof polymer.

) ■ Catalytic dispersion cooling method (A stable substance that is solid at room temperature and becomes liquid when heated is used as the capsule wall membrane. Wax or thermoplastic resin is used.) ■ Spray drying method (A method that applies the principle of spray drying) An emulsified dispersion of solid particles or liquid in a polymer solution is applied to a spray dryer, and the dispersion is repelled from the atomizer in the form of fine particles, at which point the internal substances are surrounded by the polymer. A compound of the same kind or a different kind that produces an oil-insoluble polymer substance is dissolved in an oily liquid in the presence of a low boiling point solvent or a polar liquid that forms a continuous phase and a polar solvent that has lacquer properties. After dispersing and emulsifying the magnetic liquid to be formed, the system is heated to move the wall film-forming substance to the oil-filled surface, and a polymer production reaction proceeds on the oil droplet surface to form a wall film. This applies to products made using microencapsulation technology. Dispersion forms of microcapsules produced by such a method in adhesive-coated products include: (1) a form in which a microcapsule layer is provided between the support and the adhesive layer, (2) a form in which microcapsules are dispersed in the adhesive layer. (1) A form in which microcapsules are dispersed and contained in a support (for example, paper) layer, (2) A form in which a microcapsule layer is provided on the opposite side of the adhesive layer through a support, (2) or an appropriate combination of the above forms. Possible forms are possible. Among the above configurations, the option (■) involves exploring a method in which microcapsules are mixed into the paper during the papermaking stage, but there are some that are washed away with the white water, making it unsatisfactory. However, this is difficult as a practical method.

Form (2) has a microcapsule layer on the surface of the support, so it is difficult to print and write on this surface. For this reason, the manufacturing and cost aspects of the product,
Considering the quality, etc., the distribution form of the microcapsules is practically the form of ■ and/or ■. The particle size of the microcapsules is not particularly determined, but when they are included in the adhesive layer, it is preferable that they do not protrude from the adhesive layer as much as possible. Even if protrusion does occur, if the extent is slight, it is possible to reduce the decrease in adhesive strength by using a capsule that deforms under external pressure, but use a capsule that does not protrude from the adhesive layer. It's not a big deal. The particle diameter is also relatively determined depending on the thickness of the adhesive layer.
Next, regarding the distribution amount of microcapsules,
There is no particular problem in the forms of ■ and ■, but in the form of (■) in which microcapsules are dispersed and contained in the adhesive layer, it is practical to use 0.1 to 50 parts by weight based on 10 parts by weight of the main adhesive component. and most preferably 1 to 30 parts by weight.

Incidentally, if it is less than 0.1 part by weight, the desired mold release effect cannot be obtained, and if it is more than 50 parts by weight, it is necessary for mold release in cutting processing parts such as slitter processing, guillotine processing, die cutting processing, etc. This is because an amount of the template agent exceeding the specified amount flows out of the capsule and permeates into the adhesive layer, gradually reducing the adhesive force of the adhesive. In addition, when microcapsules are contained solely for the purpose of being an extender for the adhesive, the present applicant's 1973
As in the case of the patent application filed May 1, 2013, the content ratio of microcapsules to adhesive can range from 1:99 to 80:20.

Therefore, the pressure-sensitive adhesive coated product according to the present invention can be processed by slitter cutting, guillotine cutting, etc. according to its use.
When cutting is performed, the microcapsules are destroyed in the cutting process, and the release agent contained in the microcapsules as a core material adheres to the processing blade, resulting in a constant release agent film. This has the effect of preventing the adhesive from sticking to the sheet, and there is no reduction in cutting efficiency, allowing for smooth paper feeding when printing on sheets or attaching labels.

Examples of the present invention will be described below.

Example 1 31 parts by weight of a 6% aqueous gelatin solution was emulsified with 10 parts by weight of silicone oil (trade name: Shin-Etsu Silicon KF-96 "manufactured by Shin-Etsu Chemical") to obtain an emulsion with an average particle size of 5.0 mm. After that, 190 parts by weight of 10% aqueous gum arabic solution and 10 parts by weight of water
Part by weight of the mother was added, and the pH of the system was adjusted to 4.2 with acetic acid.

Next, the temperature of the system was cooled to 10 qo, one box weight part of a 10% aqueous formalin solution was added, and the pH of the system was adjusted to 10.2 with a 5% aqueous sodium hydroxide solution to form a microcapsule dispersion containing a mold release agent. Obtained. This dispersion was applied to the uncoated side of cast-coated paper after 85 days of dry weight for 5 days of dry weight.
I applied it later and let it dry. On the other hand, a copolymer latex (aqueous emulsion with a solid content of 55%) consisting of 8 parts by weight of 2-ethylhexyl acrylate, 8 parts by weight of methyl acrylate, 10 parts by weight of vinyl acetate, and 2 parts by weight of acrylic acid was mixed with an alkali-swelled acrylic ester. Copolymer (
3 parts by weight of Primal ASE-60 (trade name, manufactured by Rohm and Haas) were added, and aqueous ammonia diluted to 10% was added while stirring with a propeller mixer so that the viscosity of the system was 500 ps.

The pressure-sensitive adhesive thus prepared was coated on polyethylene laminate release paper, which had been siliconized in advance and had a thickness of 90 degrees, using a reverse roll coater, and was dried at a rate of 25 degrees. The cast coated paper (microcapsule coated surface) was laminated to the adhesive coated surface under a pressure of 15.4 k9/c to produce a pressure sensitive adhesive sheet. In order to evaluate the suitability of finishing processing of this adhesive sheet, the adhesive sheet was
Cut into C pieces, stack 100 pieces and use a guillotine test machine (CM
The amount of adhesive residue adhering to the guillotine blade was measured after 20 consecutive cuttings in the width direction using a guillotine tester (Model 450, Rokugo Seisakusho), and the results were as described in the attached paper. The adhesive strength of this pressure-sensitive adhesive sheet was as shown in the attached table. Example 2 25 parts by weight of microcapsules prepared in the same manner as described in Example 1 were mixed with 80 parts by weight of 2 ethylhexyl acrylate.
8 parts by weight of methyl acrylate, 1 part by weight of vinyl acetate, and 2 parts by weight of acrylic acid. Add 3 parts by weight of acid ester copolymer (trade name: "Primal ASE-60" manufactured by Rohm and Haas) and dilute ammonia water to 10% while stirring with a propeller mixer until the viscosity of the system is 500 ps. Added so that

The adhesive thus prepared was coated on a 90 mm polyethylene laminate release paper which had been previously treated with silicone using a reverse roll coater at a thickness of 25 mm and dried. A pressure-sensitive adhesive sheet was produced by laminating cast-coated paper of 85 mm/mm on the adhesive-coated surface at a pressure of 15.4 k9/mm. Regarding this adhesive sheet, the suitability for cutting was evaluated in the same manner as in Example 1, and the adhesive strength of the adhesive sheet was measured, and the results were as shown in the attached sheet.

Example 3 A pressure-sensitive adhesive sheet was produced in the same manner as in Example 1 except that coconut oil was used as the mold release agent included as the core material of the microcapsules.

The suitability for cutting and adhesive strength of this pressure-sensitive adhesive sheet were measured in the same manner as in Example 1, and the results were as shown in the attached table. Example 4 A pressure-sensitive adhesive sheet was produced in the same manner as in Example 2 except that oleic acid was used as the core material of the microcapsules.

The suitability for cutting and adhesive strength of this pressure-sensitive adhesive sheet were measured in the same manner as in Example 1, and the results were as shown in the attached table.

Comparative Example 1 A pressure-sensitive adhesive sheet was produced in the same manner as in Example 1, except that microcapsules containing a release agent as a core material were not distributed at all.

The suitability for cutting and adhesive strength of this pressure-sensitive adhesive sheet were measured using the same machine as in Example 1, and the results were as shown in the attached table. Comparative Example 2 A pressure-sensitive adhesive sheet was produced in the same manner as in Example 2, except that 25 parts by weight of silicone oil was directly added and mixed as a release agent to parts by weight of the pressure-sensitive adhesive 10 described in Example 1.

The suitability for cutting and adhesion of this pressure-sensitive adhesive sheet were measured in the same manner as in Example 1, and the results were as shown in the attached sheet. Attached table (Note) Measurement of adhesive strength is based on JIS-Z-1538 (6.8
’) Based on the measurement of the normal adhesive strength specified.

Claims (1)

[Claims] 1. An adhesive coating with excellent cutting suitability, characterized in that a product coated with an adhesive is coated with or contains micropsel having a mold release agent as a core substance to prevent the adhesive from adhering to the processing blade. product.