JP2021008585A - Method for producing self-adhesive film - Google Patents

Abstract

To provide a method for producing a self-adhesive film, the method allowing for preferred production of a self-adhesive film which can be easily determined whether it is peeled and whether it is forged, with simple constitution.SOLUTION: A method for producing a self-adhesive film includes: a laminate preparation step of preparing a laminate in which a substrate not substantially transmitting UV-C wave, a self-adhesive agent layer cured by the UV-C wave and a peeling liner are overlapped in this order, the peeling liner having a liner body transmitting the UV-C wave and having a printing layer not substantially transmitting the UV-C wave; and a curing step of partially curing the self-adhesive agent layer by irradiating the laminate with light beam including the UV-C wave from the peeling liner side.SELECTED DRAWING: None

Description

The present invention relates to a method for producing an adhesive film.

A tamper-proof label may be affixed to the sealing port so that the fact of opening can be easily recognized when the sealing body is provided by storing and sealing the contents. This is, for example, to prevent the stored object of the sealed body from being tampered with or misused by being opened and taken out at an unintended timing or by an unintended person. In addition, a tamper-proof label may be affixed to the product to ensure that it is genuine. As the tamper-proof label, when it is removed from the attached adherend (the above-mentioned sealing body, product, etc.), the base material of the tamper-proof label is easily destroyed, so that it is easy to remove. (See, for example, Patent Document 1).

However, even if the tamper-proof label is easily destroyed when it is removed, it can be applied to both the tamper-proof label and the adherend by carefully handling it with a glue remover or heating. It can be peeled off (removed) without leaving any trace of destruction or damage. Therefore, the removed tamper-proof label can be reused by reapplying an adhesive on the sticking surface, and it is difficult to notice the fact of reuse unless it is carefully observed. There was a point.

As a falsification prevention label that is difficult to reuse or forge, a label having a complicated structure using a easily destructible hologram, RFID (radio frequency identifier), or the like has been proposed. However, these labels themselves are expensive, and it is not realistic to use them in general-purpose products that are distributed in large quantities.

Japanese Unexamined Patent Publication No. 10-116031

An object of the present invention is to provide a method for producing an adhesive film, which can suitably produce an adhesive film capable of easily determining the presence or absence of peeling and counterfeiting with a simple structure.

Such an object is achieved by the present invention described in the following (1) to (10).
(1) A base material that does not substantially transmit ultraviolet C waves, an adhesive layer that is cured by the ultraviolet C waves, a liner body that transmits the ultraviolet C waves, and a printing layer that does not substantially transmit the ultraviolet C waves. A laminate preparation step of preparing a laminate in which the release liners having the above are laminated in this order, and
A method for producing an adhesive film, which comprises a curing step of partially curing the pressure-sensitive adhesive layer by irradiating the laminate with a light ray containing the ultraviolet C wave from the release liner side.

(2) The method for producing an adhesive film according to (1) above, wherein the base material contains polyethylene terephthalate.

(3) The laminate preparation step is
A pressure-sensitive adhesive layer forming step of applying an ultraviolet C-wave curable pressure-sensitive adhesive composition that is cured by the ultraviolet-C wave onto one surface side of the base material to form the pressure-sensitive adhesive layer.
A bonding step of bonding the liner body onto the pressure-sensitive adhesive layer,
The method for producing an adhesive film according to (1) or (2) above, wherein the liner body has a printing step of forming the printing layer on the surface opposite to the surface facing the adhesive layer.

(4) The laminate preparation step is
An adhesive layer forming step of applying an ultraviolet C wave curable pressure-sensitive adhesive composition cured by the ultraviolet C wave to one surface side of the liner body to form the pressure-sensitive adhesive layer.
A bonding step of bonding the base material on the pressure-sensitive adhesive layer and
The method for producing an adhesive film according to (1) or (2) above, wherein the liner body has a printing step of forming the printing layer on the surface opposite to the surface facing the adhesive layer.

(5) The ultraviolet C-wave curable pressure-sensitive adhesive composition contains, in addition to a polymer exhibiting adhesiveness, a low-molecular-weight compound having an ultraviolet C-wave reactive group that contributes to a cross-linking reaction by irradiation with the ultraviolet C-wave. The method for producing an adhesive film according to (3) or (4) above.

(6) Any of the above (3) to (5), wherein the ultraviolet C wave curable pressure-sensitive adhesive composition contains a polymer having an ultraviolet C wave reactive group that contributes to a cross-linking reaction by irradiation with the ultraviolet C wave. The method for producing an adhesive film described in Crab.

(7) The method for producing an adhesive film according to (5) or (6) above, wherein the ultraviolet C-wave reactive group is a functional group having a benzophenone structure.

(8) The method for producing an adhesive film according to any one of (3) to (7) above, wherein the ultraviolet C wave curable pressure-sensitive adhesive composition contains an acrylic polymer.

(9) The method for producing an adhesive film according to any one of (3) to (8) above, wherein the ultraviolet C wave curable pressure-sensitive adhesive composition is an ultraviolet C wave curable hot melt adhesive composition.

(10) The method for producing an adhesive film according to any one of (1) to (9) above, wherein the printing layer is formed by halftone dot printing.

According to the present invention, it is possible to provide a method for producing an adhesive film, which can suitably produce an adhesive film capable of easily determining the presence or absence of peeling and counterfeiting with a simple structure.

It is a schematic vertical sectional view which shows the preferable embodiment of the manufacturing method of the adhesive film of this invention. It is a schematic vertical sectional view which shows the preferable embodiment of the manufacturing method of the adhesive film of this invention. It is a schematic vertical sectional view which shows the preferable embodiment of the manufacturing method of the adhesive film of this invention. It is a schematic plan view which enlarges and shows the vicinity of the pattern part of a print layer. It is a schematic vertical sectional view which shows an example of the state in which the adhesive film produced by the method of this invention is attached to an adherend. It is a schematic vertical sectional view which shows an example of the state which is about to peel off the adhesive film shown in FIG. 5 from an adherend. FIG. 5 is a schematic vertical sectional view showing an example of a state in which the adhesive film shown in FIG. 5 is peeled off from an adherend.

Hereinafter, preferred embodiments of the present invention will be described in detail.
[Manufacturing method of adhesive film]
The method for producing the adhesive film of the present invention will be described.

1 to 3 are schematic vertical sectional views showing a preferred embodiment of the method for producing an adhesive film of the present invention. Further, FIG. 4 is a schematic plan view showing an enlarged vicinity of the pattern portion of the print layer.

The method for producing the adhesive film 1 of the present invention includes a base material 10 that does not substantially transmit ultraviolet C waves (UVC), an adhesive layer 20 that is cured by ultraviolet C waves, a liner body 31 that transmits ultraviolet C waves, and a liner body 31 that transmits ultraviolet C waves. A laminate preparation step (see FIG. 1) in which a release liner 30 having a printing layer 32 that does not substantially transmit ultraviolet C waves is superposed in this order, and an ultraviolet C wave for the laminate 50. It has a curing step (FIG. 2) in which the pressure-sensitive adhesive layer 20 is partially cured by irradiating a light beam containing ultraviolet rays from the release liner 30 side.

As described above, the method for producing the pressure-sensitive adhesive film 1 of the present invention is characterized in that light rays containing ultraviolet C waves are used for the curing reaction (crosslinking reaction) of the pressure-sensitive adhesive layer 20.

In particular, in the present invention, by irradiating the pressure-sensitive adhesive layer 20 with light rays including ultraviolet C waves from the release liner 30 side, ultraviolet rays are selectively applied to a portion of the pressure-sensitive adhesive layer 20 where the printing layer 32 is not provided. A C wave is incident, and a cured portion (crosslinked portion) 21 is formed in the pressure-sensitive adhesive layer 20 with a pattern (inverted pattern of the printed layer 32) corresponding to a portion where the printed layer 32 is not provided, and other portions. Is the uncured portion (non-crosslinked portion) 22 (see FIG. 3).

In the present specification, the ultraviolet C wave is an ultraviolet ray having a wavelength region of 200 nm or more and less than 280 nm. Ultraviolet C waves are contained in the sun's rays, but are absorbed by the ozone layer, so they are not substantially contained in the sun's rays that reach the surface of the earth.

In the present invention, by using ultraviolet C waves to cure the pressure-sensitive adhesive layer 20, a pattern consisting of a cured portion (crosslinked portion) 21 and a non-cured portion (non-crosslinked portion) 22 is suitably formed on the pressure-sensitive adhesive layer 20. be able to. Further, since the ultraviolet C wave has a short wavelength and high energy, the pressure-sensitive adhesive layer 20 can be cured (formation of the cured portion 21) more efficiently and in a short time.

Further, since the ultraviolet C wave is not substantially contained in the sunlight on the ground, the adhesive layer 20 is particularly non-existent when the laminate 50 or the adhesive film 1 is stored or the adhesive film 1 is used. It is possible to effectively prevent the cured portion 22 (non-crosslinked portion) from undergoing an unintentional curing (crosslinking) reaction.

According to the present invention, it is possible to provide a manufacturing method capable of suitably manufacturing the pressure-sensitive adhesive film 1 capable of easily determining the presence or absence of peeling and counterfeiting with a simple structure. The presence or absence of peeling and counterfeiting of the adhesive film according to the present invention can be easily determined, and the mechanism for obtaining such an excellent effect will be described in detail later.

Hereinafter, each step will be described.
≪Laminated body preparation process≫
In the laminate preparation step, as shown in FIG. 1, the base material 10 that does not substantially transmit the ultraviolet C wave, and the adhesive layer 20 that is provided on one surface side of the base material 10 and is cured by the ultraviolet C wave. , A laminate 50 having a release liner 30 in contact with the pressure-sensitive adhesive layer 20 is prepared. The peeling liner 30 has a liner main body 31 that transmits ultraviolet C waves and a printing layer 32 that does not substantially transmit ultraviolet C waves.

In the laminate preparation step, the laminate 50 as described above may be prepared. For example, an ultraviolet C wave curable pressure-sensitive adhesive composition that is cured by an ultraviolet C wave is applied to one surface side of the base material 10. A pressure-sensitive adhesive layer forming step of forming the pressure-sensitive adhesive layer 20 and a bonding step of bonding a release liner 30 (a liner body 31 without a printing layer 32) on the pressure-sensitive adhesive layer 20 and a release liner 30. A printing step of forming the printing layer 32 may be provided on the surface side opposite to the surface facing the pressure-sensitive adhesive layer 20.

As a result, the laminated body 50 can be obtained more efficiently, and the productivity of the adhesive film 1 can be made more excellent. In particular, the productivity of the adhesive film 1 can be further improved by storing the laminated body in which the print layer 32 is not provided. Further, by storing the laminated body in which the print layer 32 is not provided, for example, the print layer 32 having a pattern that meets the needs of the customer can be suitably formed. Further, it is possible to suitably cope with the formation of print layers 32 having different patterns.

The print layer 32 may be formed on the liner main body 31 before being bonded to the pressure-sensitive adhesive layer 20. Further, the pressure-sensitive adhesive layer 20 may be formed on the release liner 30 and then bonded to the base material 10. Further, in the illustrated configuration, the print layer 32 is provided on the outer surface of the release liner 30 (the surface opposite to the surface facing the adhesive layer 20) in the laminate 50, but at least a part thereof is provided. It may be provided inside the liner body 31 (for example, impregnated inside the liner body 31), or may be provided on the surface side of the release liner 30 facing the adhesive layer 20 in the laminate 50. It may have been printed.

The ultraviolet C-wave curable pressure-sensitive adhesive composition may have the property of being cured by irradiation with ultraviolet C-waves, but is preferably a hot-melt pressure-sensitive adhesive composition.

As a result, the pressure-sensitive adhesive layer 20 having excellent adhesion to the base material 10 can be more preferably formed.

Here, the hot-melt adhesive composition refers to a type of adhesive composition that melts by heating and can be spread and coated, and exhibits adhesiveness and cohesive force by cooling.

<Adhesive layer forming process>
In the pressure-sensitive adhesive layer forming step, the UV-C wave-curable pressure-sensitive adhesive composition is applied to one surface side of the base material 10 to form the pressure-sensitive adhesive layer 20.

(Base material)
The base material 10 serves as a support for supporting the pressure-sensitive adhesive layer 20.
The base material 10 is substantially impermeable to ultraviolet C waves.

In the present specification, "substantially not transmitting ultraviolet C waves" means that the transmittance of ultraviolet C waves having a wavelength of 200 nm or more and less than 280 nm is 3% or less, and in particular, the ultraviolet C waves. The transmittance is preferably 1% or less, more preferably 0.5% or less.

Further, the base material 10 may be one that does not substantially transmit the ultraviolet C wave in the thickness direction as a whole. For example, the ultraviolet C wave irradiated from one surface side of the base material 10 may be transmitted. Any material may be used as long as it is reflected or absorbed by a part or the whole of the base material 10 so as not to be transmitted to the other surface side. The base material 10 may be made of a material that is partially transparent to ultraviolet C waves in the thickness direction.

Examples of the constituent material of the base material 10 include paper, plastic, metal, and the like, and one or a combination of two or more selected from these can be used.

In particular, the base material 10 is preferably made of a material containing polyethylene terephthalate (PET).

As a result, the transmittance of the ultraviolet C wave for the base material 10 can be made lower, and the transparency of the base material 10 can be increased. Therefore, the aesthetic appearance of the adhesive film 1 when the printing layer is provided on the base material 10 can be made more excellent. Further, the adhesion between the base material 10 and the printing layer provided on the base material 10 (particularly, the printing layer formed by using the ultraviolet curable ink) can be made more excellent. In addition, adhesive films 1 having various appearances can be suitably manufactured. Further, the adhesion between the base material 10 and the pressure-sensitive adhesive layer 20 can be made more excellent.

When the base material 10 is made of a material containing polyethylene terephthalate, the content of polyethylene terephthalate in the base material is preferably 50% by mass or more, more preferably 80% by mass or more. It is more preferably 90% by mass or more.
As a result, the above-mentioned effect is more prominently exhibited.

The base material 10 may have a single-layer structure or a multi-layer structure in which a plurality of layers are laminated. Further, the composition of the base material 10 may be constant in the thickness direction, or may have an inclined structure that gradually changes.

When the base material 10 has a multi-layer structure, for example, at least one layer may be made of a material that does not substantially transmit ultraviolet C waves. More specifically, for example, even when the base material body is made of a material that transmits ultraviolet C waves, the base material 10 is made impermeable to ultraviolet C waves by depositing a metal on at least one surface thereof. (Reflectivity) can be imparted. Examples of the metal material include aluminum and the like.

Further, for example, even if the main component of the base material 10 transmits ultraviolet C waves, the base material 10 is imparted with ultraviolet C wave impermeableness by adding an ultraviolet absorber that absorbs ultraviolet C waves. can do.

When the adhesive film 1 is stored or used, the base material 10 side is usually exposed to the surface. Although the ultraviolet C wave is hardly contained in the sunlight on the ground, the base material 10 does not substantially transmit the ultraviolet C wave, so that the base material 10 is transmitted during storage and use. It is possible to effectively prevent the non-cured portion 22 (non-crosslinked portion) of the pressure-sensitive adhesive layer 20 from being unintentionally cured (crosslinked) by the light reaching the pressure-sensitive adhesive layer 20.

Further, as will be described later, when a print layer is formed on the base material 10 using an ultraviolet curable ink (for example, when the adhesive film 1 is used as a label), the print layer (for example, when the adhesive film 1 is used as a label) is formed after the adhesive layer 20 is formed. Even if the base material 10) is formed, the ultraviolet C wave contained in the ultraviolet rays used for curing the ultraviolet curable ink is preferably prevented from being transmitted by the base material 10, so that the pressure-sensitive adhesive layer 20 is intended. It is possible to effectively prevent the ink from hardening (crosslinking).

The base material 10 may be, for example, colorless and transparent, or may be colored.
When the base material 10 is colored, for example, when the base material 10 is provided with the print layer, the visibility of the print layer can be improved regardless of the conditions of the adherend 100. Further, as described above, the printing layer provided on the base material 10 is formed by forming an aluminum vapor deposition film on the surface of the base material 10, for example, the surface of the base material 10 on the side where the pressure-sensitive adhesive layer 20 is arranged. Visibility can be further improved.

Further, as will be described in detail later, since the base material 10 is colored, the cured portion 21 and the non-cured portion 22 of the pressure-sensitive adhesive layer 20 when the pressure-sensitive adhesive film 1 is peeled off from the adherend 100. The difference in contrast can be made larger, and the distinguishability of the pattern formed by the cured portion 21 and the non-cured portion 22 can be further improved.

In particular, when the pattern formed by the cured portion 21 and the non-cured portion 22 is a fine pattern such as a barcode or a QR code (registered trademark), visibility and reading accuracy can be improved more preferably. ..

The thickness of the base material 10 is not particularly limited, but is preferably 15 μm or more and 300 μm or less, and more preferably 30 μm or more and 200 μm or less.

A printing layer (not shown) may be provided on the base material 10. Thereby, for example, the adhesive film 1 can be suitably used as a label.

The pattern of the printing layer formed on the base material 10 is not particularly limited, and includes, for example, various characters, symbols, symbols, dots, lines, figures, or a combination of two or more thereof, and is arbitrary. Can be content. Further, for example, a printing layer having the same pattern may be provided on a plurality of adhesive films 1 (labels) (for example, adhesive films 1 as a plurality of labels attached to different adherends 100). However, printing layers having different patterns (for example, serial numbers, product information, etc., which are individually different for individual identification) may be provided. Further, the printing layer formed on the base material 10 may be a one-dimensional bar code, a two-dimensional code such as a QR code (registered trademark), or the like.

The printing layer formed on the base material 10 is formed by various printing methods such as flexo printing, offset printing, gravure printing, screen printing, inkjet printing, laser beam dry electrophotographic printing, fusion type or sublimation type thermal transfer printing, and the like. be able to.

The ink used to form the print layer on the base material 10 is not particularly limited, and for example, oil-based ink, water-based ink, photocurable ink (ultraviolet curable ink, electron beam curable ink) and the like can be used. However, from the viewpoint of environment and energy, photocurable ink, particularly ultraviolet curable ink, is preferable.

Examples of the ultraviolet curable ink include oligomers such as epoxy acrylate, urethane acrylate and polyester acrylate, colorants such as ultraviolet polymerization initiators and pigments, dispersants, additives, monofunctional or polyfunctional monomers and the like. Examples include those that have been used. When the print layer is formed of an ultraviolet curable ink, after printing with the ink, it is cured by irradiating UV with an ultraviolet (UV) lamp. By using a photocurable ink as the ink, the manufacturing process can be made solvent-free, and the adhesive film 1 can be manufactured at a lower cost and with higher production efficiency while paying attention to the environment.

When a printing layer is formed on the base material 10 using an ultraviolet curable ink in a state where the pressure-sensitive adhesive layer 20 is laminated on the base material 10, usually, printing is performed on the base material 10 using the ultraviolet curable ink. , The ink is cured by irradiating ultraviolet rays from the surface side of the base material 10 to which the ink is applied. Here, when the ultraviolet C wave contained in the ultraviolet rays reaches the pressure-sensitive adhesive layer 20, the pressure-sensitive adhesive layer 20 is unintentionally cured, but the base material 10 does not substantially transmit the ultraviolet C wave. Therefore, it is possible to effectively prevent the occurrence of the above-mentioned problems.

When the printing layer is provided on the base material 10, the formation timing thereof is not particularly limited, and may be, for example, before the curing step described later or after the curing step. Further, a printing layer may be formed on the base material 10 before the pressure-sensitive adhesive layer 20 is formed on the base material 10.

(Adhesive layer)
The pressure-sensitive adhesive layer 20 is a portion that comes into contact with and joins the adherend 100 when the pressure-sensitive adhesive film 1 is attached to the adherend 100.

The pressure-sensitive adhesive layer 20 is formed by using an ultraviolet C-wave curable pressure-sensitive adhesive composition that can undergo a curing reaction by irradiation with ultraviolet C-waves.

As such an ultraviolet C-wave curable pressure-sensitive adhesive composition, for example, one containing a polymer having an ultraviolet C-wave reactive group that contributes to a cross-linking reaction by irradiation with ultraviolet C-wave can be used.

Further, the ultraviolet C-wave curable pressure-sensitive adhesive composition contains, for example, a low-molecular-weight compound having an ultraviolet C-wave reactive group that contributes to a cross-linking reaction by irradiation with ultraviolet C-wave, in addition to a polymer exhibiting adhesiveness. Can be used.

The ultraviolet C-wave reactive group is excited by irradiation with ultraviolet C-waves to generate radicals that trigger a curing reaction (crosslinking reaction).

Examples of the ultraviolet C-wave reactive group include a functional group having a benzophenone structure, a functional group having a benzyl structure, a functional group having an o-benzoylbenzoic acid ester structure, a functional group having a thioxanthone structure, and a 3-ketocoumarin structure. Examples thereof include a functional group, a functional group having a 2-ethylanthraquinone structure, a functional group having a camphorquinone structure, and the like, and a functional group having a benzophenone structure is preferable.

Thereby, the reactivity to the ultraviolet C wave can be made more excellent, and the stability to the stimulus other than the ultraviolet C wave can be made more excellent.

From the viewpoint of transparency, the ultraviolet C wave curable pressure-sensitive adhesive composition preferably contains an acrylic polymer as a polymer having adhesiveness.

The acrylic polymer is a polymer or copolymer of an acrylic monomer.
Examples of the acrylic monomer include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, sec-butyl (meth) acrylate, and the like. n-hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, isooctyl (meth) acrylate, n-nonyl (meth) acrylate, isononyl (meth) acrylate, n-decyl (meth) Examples thereof include alkyl (meth) acrylates such as acrylates and lauryl (meth) acrylates. In particular, acrylic polymers contain alkyl (meth) acrylates having an alkyl group having 1 or more and 8 or less carbon atoms as an acrylic monomer. Is preferable. Among the alkyl (meth) acrylates having an alkyl group having 1 or more and 8 or less carbon atoms, 2-ethylhexyl (meth) acrylate, methyl (meth) acrylate and butyl (meth) acrylate are particularly preferable.

When the polymer contained in the ultraviolet C-wave curable pressure-sensitive adhesive composition has an ultraviolet C-wave reactive group, the ultraviolet C-wave reactive group is usually introduced into the side chain of the polymer.

In particular, when the acrylic polymer has an ultraviolet C-wave reactive group, the ratio of the ultraviolet C-wave reactive group to the entire acrylic polymer is 0.1% by mass or more and 5.0% by mass or less. It is preferably 0.2% by mass or more and 3.0% by mass or less.

As a result, the pot life of the ultraviolet C-wave curable pressure-sensitive adhesive composition can be extended, and the adhesiveness of the pressure-sensitive adhesive layer 20 can be made more excellent.

As an acrylic polymer exhibiting such an ultraviolet C-wave reactive group, for example, the trade name "acResin (registered trademark) UV" is commercially available from BASF. Examples of "acResin (registered trademark) UV" include "acResin (registered trademark) A250 UV", "acResin (registered trademark) A260 UV", "acResin (registered trademark) A204 UV", and "acResin (registered trademark) UV 3532". Can be mentioned.

When a UV C-wave curable pressure-sensitive adhesive composition containing a low-molecular-weight compound having a UV-C-wave reactive group in addition to a polymer exhibiting tackiness is used, the low-molecular-weight compound is contained as a cross-linking agent. be able to.

Examples of the cross-linking agent include a monomer having a benzophenone structure, a monomer having a benzyl structure, a monomer having an o-benzoyl benzoic acid ester structure, a monomer having a thioxanthone structure, a monomer having a 3-ketocoumarin structure, and a 2-ethylanthraquinone structure. Examples thereof include a monomer having a benzene structure and a monomer having a benzoyl quinone structure.

The content of the cross-linking agent in the ultraviolet C-wave curable pressure-sensitive adhesive composition is preferably 5 parts by mass or more and 25 parts by mass or less, and 6 parts by mass or more and 23 parts by mass or less with respect to 100 parts by mass of the polymer. Is more preferable.

In addition to the above-mentioned components, the ultraviolet C-wave curable pressure-sensitive adhesive composition includes a dispersant, a pressure-imparting agent, an antioxidant, a polymerization initiator, an ultraviolet absorber, a light stabilizer, a heat stabilizer, and a softening agent, if necessary. Other ingredients such as agents, silane coupling agents, fillers, colorants and antioxidants may be blended. One of these may be used alone, or two or more thereof may be mixed and used.

The method for forming the pressure-sensitive adhesive layer 20 is not particularly limited, but when the ultraviolet C-wave curable pressure-sensitive adhesive composition is an ultraviolet-C-wave-curable hot-melt pressure-sensitive adhesive composition, a melt extrusion method can be preferably adopted. .. More specifically, the pressure-sensitive adhesive layer 20 can be suitably formed by supplying the melted ultraviolet C-wave curable pressure-sensitive adhesive composition onto the base material 10 from a T-die or the like using an extruder. ..

When the ultraviolet C wave curable pressure-sensitive adhesive composition is an ultraviolet C wave curable hot-melt pressure-sensitive adhesive composition, when the pressure-sensitive adhesive layer 20 is formed (the ultraviolet C wave-curable pressure-sensitive adhesive composition is supplied onto the substrate). The ultraviolet C-wave curable pressure-sensitive adhesive composition may be heated so as to be melted, but the temperature (coating temperature) of the ultraviolet-C-wave-curable pressure-sensitive adhesive composition is 120 ° C. or higher and 210 ° C. The temperature is preferably 130 ° C. or higher and 190 ° C. or lower.

As the ultraviolet C-wave curable hot melt adhesive composition, for example, a benzophenone group-containing acrylic hot melt adhesive composition is commercially available from BASF under the trade name "acResinUV". In addition, an acrylic hot melt adhesive composition is commercially available from Henkel under the trade name "LOCTITE DURO-TAK (registered trademark) UV 4606".

When the ultraviolet C wave curable pressure-sensitive adhesive composition is an ultraviolet C wave curable hot melt adhesive composition, the softening point of the ultraviolet C wave curable pressure-sensitive adhesive composition is preferably 90 ° C. or higher and 150 ° C. or lower. , 100 ° C. or higher and 150 ° C. or lower is more preferable.

When the ultraviolet C wave curable pressure-sensitive adhesive composition is an ultraviolet C wave curable hot melt adhesive composition, the melt viscosity of the ultraviolet C wave curable pressure-sensitive adhesive composition at 160 ° C. is 2000 mPa · s or more and 13000 mPa ·. It is preferably s or less, and more preferably 4000 mPa · s or more and 12000 mPa · s or less.

The melt viscosity of the ultraviolet C-wave curable pressure-sensitive adhesive composition can be determined by measurement according to JIS K6862: 1984.

The thickness of the pressure-sensitive adhesive layer 20 is preferably 5 μm or more and 100 μm or less, and more preferably 10 μm or more and 50 μm or less.

As a result, the workability when the adhesive film 1 is attached to the adherend 100 becomes more excellent, and when the adhesive film 1 attached to the adherend 100 is peeled off from the adherend 100. In addition, the traces of peeling can be more preferably identified.

<Lasting process>
In the bonding step, the liner body 31 that transmits ultraviolet C waves is bonded onto the pressure-sensitive adhesive layer 20 formed on the base material 10.

The liner main body 31 forms most of the main part of the release liner 30, and has peelability with respect to the pressure-sensitive adhesive layer 20. The release liner 30 has a function of protecting the pressure-sensitive adhesive layer 20 at least during the production of the pressure-sensitive adhesive film 1. The release liner 30 may have a function of protecting the pressure-sensitive adhesive layer 20 at least during storage of the pressure-sensitive adhesive film 1. When the pressure-sensitive adhesive film 1 is attached to the adherend 100, the release liner 30 is in a state of being peeled off from the pressure-sensitive adhesive layer 20.

In the present specification, "transmitting ultraviolet C wave" or "having ultraviolet C wave transmittance" means that the transmittance of ultraviolet C wave is 30% or more.

By using the liner main body 31 having ultraviolet C wave transmission, the adhesive layer 20 can be cured by irradiating the adhesive layer 20 with ultraviolet C waves via the release liner 30 having the liner main body 31. At this time, since oxygen is blocked, there is an advantage that the curing speed of the adhesive is increased.

The transmittance of the ultraviolet C wave for the liner body 31 may be 30% or more, preferably 50% or more, and more preferably 70% or more.

As a result, the curing reaction (crosslinking reaction) of the pressure-sensitive adhesive layer 20 can proceed more preferably.

Examples of the constituent material of the liner main body 31 include polyethylene, polypropylene and the like.

The liner body 31 may be peeled off. Examples of the peeling treatment agent used in the peeling treatment include silicone, olefin resin, isoprene resin, butadiene resin, long chain alkyl resin, alkyd resin and the like.

The thickness of the liner main body 31 is not particularly limited, but is preferably 10 μm or more and 150 μm or less, and more preferably 20 μm or more and 130 μm or less.

<Printing process>
In the printing step, a printing layer 32 that does not substantially transmit ultraviolet C waves is formed on the surface side of the liner main body 31 that is opposite to the surface facing the adhesive layer 20.

The ink is not particularly limited as long as it can form a print layer 32 that does not substantially transmit the ultraviolet C wave, but usually the ink itself does not substantially transmit the ultraviolet C wave.

As the ink, for example, oil-based ink, water-based ink, ultraviolet curable ink and the like can be used. For example, when an ultraviolet curable ink is used, the print layer 32 may be in an uncured state at a stage prior to the curing step of partially curing the pressure-sensitive adhesive layer 20.

The method for forming the print layer 32 (printing method) is not particularly limited, and examples thereof include flexo printing, offset printing, gravure printing, screen printing, inkjet printing, laser beam dry electrophotographic printing, fusion type or sublimation type thermal transfer printing, and the like. Various printing methods can be mentioned.

The print content (print pattern) of the print layer 32 is not particularly limited, and examples thereof include various characters, symbols, codes, dots, lines, and figures, and two or more types selected from these may be combined. .. Further, for example, a printing layer 32 having the same pattern for a portion to be a plurality of adhesive films 1 (labels) (for example, an adhesive film 1 as a plurality of labels attached to different adherends 100). Or a printing layer 32 having a different pattern (for example, serial number, product information, etc., which is different for individual identification) may be provided. Further, the print content (print pattern) of the print layer 32 may be, for example, a one-dimensional bar code, a two-dimensional code such as a QR code (registered trademark), or the like.

FIG. 4 is a schematic plan view showing the vicinity of the pattern portion of the print layer in an enlarged manner.
As shown in FIG. 4, the print pattern on the print layer 32 is formed as an aggregate of dots and small circles (dots 321), and gaps are provided between the dots 321 so-called halftone dot printing. It is preferably formed by (dot printing, halftone).

As a result, the following effects can be obtained. That is, in the curing step described in detail later, when the pressure-sensitive adhesive layer 20 is crosslinked by irradiation with ultraviolet C waves, the uncured portion 22 (non-crosslinked portion) corresponds to the dot 321 in the region overlapping the pattern portion of the print layer 32. It is formed as a collection of dots. In other words, a large number of non-cured portions 22 (non-crosslinked portions) are microscopically dispersed in the cured portion 21 (crosslinked portions) in the pressure-sensitive adhesive layer 20 so as to correspond to the arrangement of the dots 321. It is formed. Thereby, the adhesive force of the pressure-sensitive adhesive layer 20 as a whole to the adherend 100 can be suitably adjusted. Further, when the adhesive film 1 is once attached to the adherend 100 and then peeled off, the adhesive force of the adhesive layer 20 as a whole to the adherend 100 is appropriately reduced, so that the adhesive layer 20 is attached to the adherend 100. While effectively suppressing the generation of adhesive residue, the portion corresponding to the print pattern in the print layer 32 of the adhesive layer 20 (that is, the pattern portion of the print layer 32 when viewed in a plan view from the incident direction of the ultraviolet C wave). The surface of the overlapping portion) can be made rough as compared with the other portions of the pressure-sensitive adhesive layer 20. A pattern corresponding to the pattern portion of the print layer 32 can be made to appear on the pressure-sensitive adhesive layer 20 in a form that is easier to see.

The print duty ratio in the pattern portion is preferably 25% or more and 40% or less.

As a result, the degree of curing of the uncured portion 22 of the pressure-sensitive adhesive layer 20 as a whole can be adjusted more preferably, and the above-mentioned effect is more remarkablely exhibited.

The "print duty ratio" is the area ratio of the ink-applied portion (dot portion) in the pattern portion, which is "0%" when not printed and "0%" in the case of solid printing on the entire surface. It will be "100%".

The size of each dot 321 is not particularly limited, but is preferably 10 μm or more and 150 μm or less.

As a result, the print duty ratio of the pattern portion of the print layer 32, and by extension, the degree of curing of the entire portion of the pressure-sensitive adhesive layer 20 corresponding to the pattern portion, that is, the balance between the cured portion and the non-cured portion in the uncured portion 22. Can be adjusted more preferably, and the above-mentioned effects are more prominently exhibited.

As the density of the dots 321 is preferably 3 or / mm ² or more to 50 / mm ² or less.

As a result, the print duty ratio of the pattern portion of the print layer 32, and by extension, the degree of curing of the entire portion of the pressure-sensitive adhesive layer 20 corresponding to the pattern portion, that is, the balance between the cured portion and the non-cured portion in the uncured portion 22. Can be adjusted more preferably, and the above-mentioned effects are more prominently exhibited.

The thickness of the print layer 32 is not particularly limited as long as it does not substantially transmit ultraviolet C waves, but is preferably 0.5 μm or more and 50 μm or less, and more preferably 1.0 μm or more and 30 μm or less. It is more preferably 0.0 μm or more and 20 μm or less.

≪Curing process≫
In the curing step, as shown in FIG. 2, the pressure-sensitive adhesive layer 20 is partially cured by irradiating the pressure-sensitive adhesive layer 20 with light rays including ultraviolet C waves from the release liner 30 side.

Curing of the pressure-sensitive adhesive layer 20 is performed by irradiating a light ray containing an ultraviolet C wave from an ultraviolet C wave light source (ultraviolet C wave irradiating device) 200.

Examples of the ultraviolet C-wave light source 200 include a high-pressure mercury UV lamp, a low-pressure mercury UV lamp, a metal halide UV lamp, an excimer lamp, and a light emitting diode (LED). Of these, high-pressure mercury UV lamps and metal halide UV lamps are preferable.

When the pressure-sensitive adhesive layer 20 is irradiated with a light beam containing an ultraviolet C wave from the release liner 30 side, the printed layer 32 becomes a mask for the ultraviolet C wave irradiated to the pattern portion of the print layer 32 among the ultraviolet C waves. It is reflected or absorbed by the ink and does not reach the pressure-sensitive adhesive layer 20. On the other hand, the ultraviolet C wave irradiated to the portion (void portion) where the pattern of the print layer 32 is not formed passes through the liner main body 31 having the ultraviolet C wave transmission and reaches the adhesive layer 20.

In the pressure-sensitive adhesive layer 20, a cross-linking reaction is triggered in the portion irradiated with the ultraviolet C wave and the pressure-sensitive adhesive composition is cured, but the cross-linking reaction is not triggered in the portion not irradiated with the ultraviolet C wave and the pressure-sensitive adhesive composition is uncured. And remains soft. In this way, a cured portion 21 (crosslinked portion) and a non-cured portion 22 (non-crosslinked portion) are formed in the pressure-sensitive adhesive layer 20 corresponding to the pattern of the print layer 32 (see FIG. 3). In particular, the uncured portion 22 forms a pattern representing a predetermined content.

When the pattern of the print layer 32 is formed as an aggregate of dots or small circles (dots 321), in the pattern portion, the uncured portion 22 (non-crosslinked portion) is formed as an aggregate of dots corresponding to the dots 321. It is formed.

By using ultraviolet C waves to cure the pressure-sensitive adhesive layer 20, a pattern consisting of a cured portion (crosslinked portion) 21 and a non-cured portion (non-crosslinked portion) 22 can be suitably formed on the pressure-sensitive adhesive layer 20. Further, since the ultraviolet C wave has a short wavelength and high energy, the pressure-sensitive adhesive layer 20 can be cured (formation of the cured portion 21) more efficiently and in a short time.

Further, since the ultraviolet C wave is hardly contained in the sunlight on the ground, the adhesive layer 20 is particularly uncured portion when the laminated body 50 or the adhesive film 1 is stored or the adhesive film 1 is used. It is possible to effectively prevent 22 (non-crosslinked portion) from unintentionally curing (crosslinking).

The pressure-sensitive adhesive film 1 produced as described above may be shipped as it is (a state in which the pressure-sensitive adhesive layer 20 is coated with the release liner 30), but the release liner 30 may be peeled off, for example. The pressure-sensitive adhesive layer 20 is protected by another release liner (a release liner not provided with a printing layer corresponding to the pattern of the non-cured portion 22 (non-crosslinked portion) and the non-cured portion 22 (non-crosslinked portion)). May be good.

Further, when the adhesive film 1 has a long shape, after the release liner 30 is peeled from the adhesive layer 20, the adhesive film 1 is wound in a spiral shape, for example, with the exposed adhesive layer 20 side inside. It may be stored and transported as a tape body. In this case, the surface of the base material 10 opposite to the surface facing the pressure-sensitive adhesive layer 20 has peelability.

[Adhesive film]
Next, the pressure-sensitive adhesive film produced by the production method of the present invention will be described.

FIG. 5 is a schematic vertical cross-sectional view showing an example of a state in which the adhesive film produced by the method of the present invention is attached to an adherend. FIG. 6 is a schematic vertical sectional view showing an example of a state in which the adhesive film shown in FIG. 5 is about to be peeled from the adherend. FIG. 7 is a schematic vertical sectional view showing an example of a state in which the adhesive film shown in FIG. 5 is peeled off from the adherend.

The pressure-sensitive adhesive film 1 produced as described above can be used as, for example, a label, a tape, or the like. Then, as shown in FIG. 5, the pressure-sensitive adhesive film 1 is used by adhering the pressure-sensitive adhesive layer 20 to the adherend 100 with the pressure-sensitive adhesive layers 20 facing each other.

At this time, the cured portion 21 (crosslinked portion) and the non-cured portion 22 (non-crosslinked portion) are arranged in a predetermined pattern on the pressure-sensitive adhesive layer 20, whereby a predetermined pattern is formed.

When the adhesive film 1 is stored or when the adhesive film 1 is attached to the adherend 100, it is usually difficult to distinguish between the cured portion 21 and the non-cured portion 22.

As shown in FIGS. 6 and 7, once the pressure-sensitive adhesive film 1 attached to the adherend 100 is peeled off, the cured portion 21 (crosslinked portion) of the pressure-sensitive adhesive layer 20 is peeled off cleanly from the adherend 100. , Its surface is almost flat. Further, there is substantially no residue (glue residue) on the adherend 100 side.

On the other hand, the uncured portion 22 (non-crosslinked portion) is soft and causes stringing or cohesive failure in the adhesive layer 20 due to stress at the time of peeling, and a part of the adhesive is placed on the adherend 100 side. Remaining, so-called adhesive residue 23 is likely to occur (see FIGS. 6 and 7). In such a case, usually, not only a part of the uncured portion 22 (non-crosslinked portion) remains on the adherend 100 side, but also the uncured portion 22 (non-crosslinked portion) remaining on the adherend 100 side remains. The surface is in a rough state.

Therefore, it is easy that a part of the pressure-sensitive adhesive layer 20 remains on the adherend 100 (in particular, the pressure-sensitive adhesive layer 20 remains in a pattern corresponding to the uncured portion 22 (non-crosslinked portion)). Can be visually recognized.

Further, the trace of peeling from the adherend 100 can be easily confirmed by observing not only the adherend 100 side but also the adhesive film 1 side peeled from the adherend 100. More specifically, in the adhesive film 1 peeled off from the adherend 100, the cured portion 21 (crosslinked portion) maintains a smooth surface, whereas the non-cured portion 22 (non-crosslinked portion) remains smooth. ) Has a rough surface. Therefore, after the adhesive film 1 is peeled from the adherend 100, the cured portion 21 (crosslinked portion) and the non-cured portion 22 (non-crosslinked portion) are observed by observing the adhesive film 1 peeled from the adherend 100. The pattern of and can be easily recognized.

Further, in the configurations shown in FIGS. 6 and 7, the adhesive residue 23 is generated in the adherend 100, but even when the adhesive residue 23 is not generated, the adherend 100 is peeled off in the same manner as described above. By observing the adhesive film 1 side, traces of peeling from the adherend 100 can be easily confirmed.

As described above, the pattern portion (non-curing portion 22) of the pressure-sensitive adhesive layer 20 is preferably formed as an aggregate of dots or small circles (dots).

The adhesive film 1 preferably satisfies the following conditions. That is, the release liner 30 is removed from the adhesive film 1, the exposed adhesive layer 20 is opposed to the glass plate as the adherend 100, and the adherend 100 is reciprocated once with a 2 kg roll to apply a load. After that, when the adhesive film 1 was carefully peeled from the adherend 100, the cured portion (crosslinked) of the adhesive layer 20 of the peeled adhesive film 1 was allowed to stand in an environment of 23 ° C. A predetermined pattern (arrangement pattern of the cured portion (crosslinked portion) 21 and the non-cured portion 22 (non-crosslinked portion)) due to the difference in the surface roughness state between the portion) 21 and the non-cured portion (non-crosslinked portion) 22. ) Can be recognized.

Thereby, for various adherends, it is possible to more easily determine whether or not the adhesive film 1 is peeled off from the adherend 100, counterfeiting, and the like. That is, the effect of the present invention is more prominently exhibited.

According to the adhesive film 1 according to the present invention, the following effects can be obtained. That is, for example, a product manager and a consumer can easily identify the opened or unopened state of a product simply by looking at the adhesive film 1 (label) attached to the product when purchasing the product. it can. Therefore, even if the adhesive film 1 is peeled off and the product is cheated, the adhesive film 1 once peeled off is attached to the product again to eliminate the evidence that the adhesive film 1 is peeled off. When the pressure-sensitive adhesive film 1 produced by the method of the present invention is used, evidence of peeling remains clearly on the pressure-sensitive adhesive film 1, which can be easily recognized by the manager and the consumer. Therefore, when the adhesive film 1 according to the present invention is used, falsification or fraud can be prevented by attaching the adhesive film 1 to a product. Therefore, the adhesive film 1 according to the present invention is useful as a sealing label, particularly as a sealing label for products such as pharmaceuticals and foodstuffs. It is also useful as a tamper-proof label on which product information such as serial numbers of electronic devices and electrical products is written. When the adhesive film 1 (regular label) according to the present invention is once attached to the adherend 100 and then peeled off, at least the surface of the adhesive layer 20 is roughened to display a certain pattern.

Although preferred embodiments of the present invention have been described above, the present invention is not limited thereto.

For example, the pressure-sensitive adhesive film according to the present invention may further include a configuration other than those described above. For example, the pressure-sensitive adhesive film according to the present invention may include a coat layer (for example, a coat layer for printing) and an intermediate layer.

Further, the method for producing an adhesive film of the present invention may include a laminate preparation step and a curing step, and may further include other steps.

Further, in the above-described embodiment, the case where the pressure-sensitive adhesive layer forming step, the bonding step, and the printing step are performed in this order in the laminate preparation step has been mainly described, but the order of these steps is changed. You may go.

For example, a printing layer may be formed on the liner body before joining the liner body (release liner) via the pressure-sensitive adhesive layer to the base material.

Further, in the above-described embodiment, the case where the pressure-sensitive adhesive composition is applied to one surface side of the base material to form the pressure-sensitive adhesive layer on the base material has been mainly described, but the pressure-sensitive adhesive layer is the liner main body. The liner body formed on one surface side and then provided with the adhesive layer may be bonded to the base material.

Further, in the above-described embodiment, a case where a hot-melt type pressure-sensitive adhesive composition is used for forming the pressure-sensitive adhesive layer and the pressure-sensitive adhesive composition is heated and melted for coating has been mainly described. The material is not particularly limited as long as it is made of a material that is cured by irradiation with ultraviolet C waves, and may be, for example, a solution-type pressure-sensitive adhesive composition containing a solvent.

Hereinafter, the present invention will be described in detail based on specific examples, but the present invention is not limited thereto. The treatments and measurements in the following examples, which did not indicate the temperature conditions, were carried out at room temperature (23 ° C.).

[Manufacturing of adhesive film]
(Example 1)
First, as a base material, a film having a thickness of 50 μm made of polyethylene terephthalate (manufactured by Toyobo Co., Ltd., trade name “Cosmo Shine A4300”) was prepared. The transmittance of ultraviolet C waves for the substrate was 0.5% or less.

An ultraviolet C wave curing type hot melt adhesive composition is applied to one surface side of this base material by a hot melt coating machine to form a pressure-sensitive adhesive layer having a thickness of 25 μm, and the base material with the pressure-sensitive adhesive layer is formed. Obtained. Further, as the ultraviolet C wave curable hot melt adhesive composition, a trade name "acResin (registered trademark) UV" manufactured by BASF, which is a benzophenone group-containing acrylic hot melt adhesive composition, was used.

Next, the liner body was bonded onto the pressure-sensitive adhesive layer of the base material with the pressure-sensitive adhesive layer. As the liner body, a polypropylene film (thickness 38 μm) having a peeling treatment on the surface in contact with the adhesive layer was used. The transmittance of the ultraviolet C wave for the liner body was 70% or more.

Next, a print layer was formed on the outer surface (the surface opposite to the surface facing the adhesive layer) of the liner body in a predetermined pattern, and a release liner provided with the print layer on the liner body was obtained. A laminate in which the release liner, the pressure-sensitive adhesive layer, and the base material were laminated in this order was obtained. The print layer was formed by using Flexiproof 100 manufactured by RK Print Coat Instruments Co., Ltd. and UV161 ink manufactured by T & K TOKA Co., Ltd. as the ink.

Next, a high-pressure mercury lamp (Eye Graphics Co., eye Gran stage ECS-4011GX) as ultraviolet irradiation apparatus using a from the release liner side of the laminate, irradiation intensity 48 mW / cm ^2, accumulated light quantity 60 mJ / cm ² A pressure-sensitive adhesive film was obtained by irradiating a light beam containing an ultraviolet C wave under the above conditions to cure the printed layer and partially curing the pressure-sensitive adhesive layer. At this time, in the pressure-sensitive adhesive layer, a uncured portion was formed as an aggregate of dots corresponding to the pattern of the printed layer. A cured portion was formed in the other portion. The transmittance of the ultraviolet C wave for the print layer was 0.5% or less. The thickness of the print layer was 2 μm.

[Evaluation]
First, the release liner was peeled off from the adhesive film produced in the above example. The pressure-sensitive adhesive layer was substantially transparent in both the cured portion and the non-cured portion, and could not be visually distinguished.

Next, the exposed adhesive layer was made to face the glass plate as an adherend, and was attached to the adherend by reciprocating once with a 2 kg roll and applying a load, and was attached to the adherend for 1 hour in an environment of 23 ° C. It was left still.

Then, the adhesive film was carefully peeled off from the adherend.
When the pressure-sensitive adhesive layer of the peeled adhesive film was observed, the surface of the cured portion of the pressure-sensitive adhesive layer was almost flat, whereas the surface of the non-cured portion was significantly roughened. The transparency was maintained in the cured portion, but the non-cured portion appeared opaque (white turbid) due to diffuse reflection of light on the surface. For this reason, a pattern corresponding to the printing layer of the release liner has also appeared on the pressure-sensitive adhesive layer side of the pressure-sensitive adhesive film.

Further, when observing the adherend after the adhesive film was peeled off, adhesive residue was generated in a pattern corresponding to the uncured portion of the adhesive layer.

From the above, in each of the above-described embodiments, when the film is once attached to the adherend and then peeled off from the adherend, the adherend can be observed or the adhesive film peeled off from the adherend can be observed. , The history of peeling could be easily identified.

Further, an adhesive film is applied in the same manner as in each of the above-described embodiments, except that a print layer is formed on the outer surface (the surface opposite to the surface facing the adhesive layer) of the liner body in a predetermined pattern by halftone dot printing. It was manufactured and evaluated in the same manner as described above. As a result, when the pressure-sensitive adhesive layer of the peeled adhesive film was observed, the surface of the cured portion of the pressure-sensitive adhesive layer was almost flat in all the pressure-sensitive adhesive films, whereas the surface of the non-cured portion was the surface. Was very rough. The transparency was maintained in the cured portion, but the non-cured portion appeared opaque (white turbid) due to diffuse reflection of light on the surface. For this reason, a pattern corresponding to the printing layer of the release liner also appears on the pressure-sensitive adhesive layer side of the pressure-sensitive adhesive film, and the peeling history can be easily identified. On the other hand, when observing the adherend after the adhesive film was peeled off, no adhesive residue was generated in the adhesive layer. In forming the print layer, the number of printing dots was 5 × 7 dots (dpi), and the printing duty ratio was 32%.

Further, after obtaining the laminated body, ultraviolet curable ink is applied to the outer surface of the base material, and then a high-pressure mercury lamp (manufactured by Eye Graphics Co., Ltd., Eye Grantage ECS) is applied from the base material side of the laminated body. An adhesive film was produced in the same manner as in each of the above-described embodiments except that a printed layer was formed on the base material by irradiating ultraviolet rays including ultraviolet C waves using -4011GX), and the same evaluation as described above was performed. It was. As a result, despite the fact that ultraviolet rays containing ultraviolet C waves were used to form the printing layer on the base material, the adhesive layer was prevented from being adversely affected by the irradiation of the ultraviolet rays, and the adhesive layer was peeled off in the same manner as described above. I was able to easily identify the history of. Then, these adhesive films were able to suitably exhibit the function as a label.

As a laminated body, an ultraviolet C wave curable hot melt adhesive composition is applied to one surface side of the liner body to form an adhesive layer, and then a base material is attached onto the adhesive layer, and then An adhesive film was produced in the same manner as above except that the one produced by forming a printing layer on the outer surface side of the liner body was used, and the evaluation was performed in the same manner as described above. As a result, the same result as described above was obtained. Obtained.

1 ... Adhesive film 10 ... Base material 20 ... Adhesive layer 21 ... Cured part (crosslinked part)
22 ... Non-cured portion (non-crosslinked portion)
23 ... Glue residue 30 ... Peeling liner 31 ... Liner body 32 ... Printing layer 321 ... Dots 50 ... Laminated body 100 ... Adhesive body 200 ... Light source

Claims (10)

Peeling having a base material that does not substantially transmit ultraviolet C waves, an adhesive layer that is cured by the ultraviolet C waves, a liner body that transmits the ultraviolet C waves, and a printing layer that does not substantially transmit the ultraviolet C waves. A laminate preparation step for preparing a laminate in which liners are laminated in this order,
A method for producing an adhesive film, which comprises a curing step of partially curing the pressure-sensitive adhesive layer by irradiating the laminate with a light ray containing the ultraviolet C wave from the release liner side. The method for producing an adhesive film according to claim 1, wherein the base material contains polyethylene terephthalate. The laminate preparation step is
A pressure-sensitive adhesive layer forming step of applying an ultraviolet C-wave curable pressure-sensitive adhesive composition that is cured by the ultraviolet-C wave onto one surface side of the base material to form the pressure-sensitive adhesive layer.
A bonding step of bonding the liner body onto the pressure-sensitive adhesive layer,
The method for producing an adhesive film according to claim 1 or 2, further comprising a printing step of forming the printing layer on the surface of the liner body opposite to the surface facing the adhesive layer. The laminate preparation step is
An adhesive layer forming step of applying an ultraviolet C wave curable pressure-sensitive adhesive composition cured by the ultraviolet C wave to one surface side of the liner body to form the pressure-sensitive adhesive layer.
A bonding step of bonding the base material on the pressure-sensitive adhesive layer and
The method for producing an adhesive film according to claim 1 or 2, further comprising a printing step of forming the printing layer on the surface of the liner body opposite to the surface facing the adhesive layer. The ultraviolet C-wave curable pressure-sensitive adhesive composition comprises a low-molecular-weight compound having an ultraviolet C-wave reactive group that contributes to a cross-linking reaction by irradiation with the ultraviolet C-wave, in addition to a polymer exhibiting adhesiveness. The method for producing an adhesive film according to 3 or 4. The ultraviolet C wave curable pressure-sensitive adhesive composition according to any one of claims 3 to 5, wherein the ultraviolet C wave curable pressure-sensitive adhesive composition contains a polymer having an ultraviolet C wave reactive group that contributes to a cross-linking reaction by irradiation with the ultraviolet C wave. Method of manufacturing adhesive film. The method for producing an adhesive film according to claim 5 or 6, wherein the ultraviolet C-wave reactive group is a functional group having a benzophenone structure. The method for producing an adhesive film according to any one of claims 3 to 7, wherein the ultraviolet C wave curable pressure-sensitive adhesive composition contains an acrylic polymer. The method for producing an adhesive film according to any one of claims 3 to 8, wherein the ultraviolet C wave curable pressure-sensitive adhesive composition is an ultraviolet C wave curable hot melt adhesive composition. The method for producing an adhesive film according to any one of claims 1 to 9, wherein the printing layer is formed by halftone dot printing.

Images