JP4437442B2 - Release liner and double-sided pressure-sensitive adhesive tape or sheet using the release liner - Google Patents

Description

  The present invention relates to a release liner and a double-sided pressure-sensitive adhesive tape or sheet using the release liner.

  Conventionally, it is known to impart peelability to an adhesive substance on a base material by forming a cured film of the silicone composition on the surface of the base material such as various types of paper, processed paper, and synthetic film. At this time, as a method of forming a film with a silicone composition, an addition reaction between an organopolysiloxane having an aliphatic unsaturated bond-containing group (such as an alkenyl group) and an organohydrogenpolysiloxane using a platinum compound as a catalyst. There are known a method for forming a cured film, a method for forming a cured film by using an organic acid metal salt catalyst such as an organotin compound and a condensation reaction of organopolysiloxane. As the silicone composition used in these methods, a solvent type dissolved in an organic solvent, an emulsion type emulsified in water, a solventless type consisting only of the silicone composition, and the like are known. In particular, from the viewpoint of productivity, an addition reaction type silicone composition having a high curing rate is often used as a release agent, and a uniform cured film can be obtained. , Tend to be produced in a form dissolved in an organic solvent such as toluene.

  The cured film (release treatment layer) with a release agent such as a silicone composition can be classified according to the magnitude of the peel strength with respect to the pressure-sensitive adhesive layer. It can be classified into three types: “heavy peeling type”, “medium peeling type”, and “light peeling type”.

  Moreover, when the double-sided pressure-sensitive adhesive tape or sheet is protected by a single release liner (separator), the release liner usually has a high peel strength with respect to the pressure-sensitive adhesive surface on each surface of the substrate. The side mold release treatment layer (heavy surface side mold release treatment layer) and the side mold release treatment layer (light surface side mold release treatment layer) having a low peel strength with respect to the adhesive surface are formed. . That is, in a release liner whose both surfaces are release surfaces, one release surface (release treatment layer surface) is usually a release surface (heavy surface) on the side having a higher peel strength with respect to the adhesive surface, and the other The peeling surface is a peeling surface (light surface). Specifically, as shown in FIG. 1, a double-sided pressure-sensitive adhesive tape in which a pressure-sensitive adhesive layer is formed on both surfaces of a base material and wound in a roll is usually a release liner base material (separator base material). ) On each surface of the release liner having a structure in which a heavy-side release processing layer and a light-side release processing layer are formed, and one adhesive layer in a double-sided adhesive tape, And the other pressure-sensitive adhesive layer in the double-sided pressure-sensitive adhesive tape is in contact with the light-side release processing layer in the release liner and the light-side release processing layer is located on the outer surface side. It has a form wound in a roll shape. Therefore, when the double-sided pressure-sensitive adhesive tape wound in the form of a roll is rewound, it is usually peeled between the light-side release processing layer of the release liner and the pressure-sensitive adhesive layer. The outer surface of the pressure-sensitive adhesive tape wound around can be the surface of the release surface of the release side of the release liner.

  FIG. 1 is a schematic diagram showing a double-sided pressure-sensitive adhesive tape wound in a roll shape. In FIG. 1, 1 is a double-sided pressure-sensitive adhesive tape wound in a roll shape (double-sided pressure-sensitive adhesive tape roll), 2 is a double-sided pressure-sensitive adhesive tape, 2a is a pressure-sensitive adhesive layer, and 2b is a base material (base material for double-sided pressure-sensitive adhesive tape). ), 2c is a pressure-sensitive adhesive layer, 3 is a release liner, 3a is a light side release processing layer, 3b is a base material (base material for release liner), and 3c is a heavy side release processing layer. The double-sided pressure-sensitive adhesive tape 2 has a configuration in which a pressure-sensitive adhesive layer 2a is formed on one surface of a substrate 2b and a pressure-sensitive adhesive layer 2c is formed on the other surface. The release liner 3 has a configuration in which a light-side release processing layer 3a is formed on one surface of the substrate 3b, and a heavy-side release processing layer 3c is formed on the other surface. In the double-sided pressure-sensitive adhesive tape roll 1, the double-sided pressure-sensitive adhesive tape 2 is in contact with the release liner 3, and the pressure-sensitive adhesive layer 2 a on one side of the double-sided pressure-sensitive adhesive tape 2 is in contact with the release surface 3 c of the release surface 3. The sheet-like material bonded in this manner is wound in a roll shape so that the pressure-sensitive adhesive layer 2c is in contact with the light-side release processing layer 3a and the light-side release processing layer 3a is positioned outside. It has a rotated form.

  However, in particular, an addition reaction type silicone release agent having a peel strength of the cured film in the range of the intermediate peel type to the heavy peel type (addition reaction type capable of forming a cured film of the intermediate peel type to the heavy peel type) The silicone-based release agent has a problem that the peel strength is remarkably lowered with the passage of time from the formation of the cured film to the pasting of the adhesive substance. Therefore, when such a silicone-based release agent is used to form a heavy-side release layer in a release liner used for a double-sided pressure-sensitive adhesive tape, the release strength of the light-side release layer with time will increase. Phenomenon in which there is no significant difference, and when the double-sided pressure-sensitive adhesive tape wound in the form of a roll is rewound, it is peeled off between the heavy-side release layer and the pressure-sensitive adhesive layer (so-called “crying phenomenon”) May occur, which may lead to a serious problem that the adhesive tape cannot be used effectively.

For example, after the reaction curing of the silicone release agent by heat or ionizing radiation, a special treatment of irradiating ultraviolet rays with an integrated illuminance of 500 to 1200 (mJ / cm ² ) is applied to this problem. There has been proposed a method for preventing a decrease in the peel strength due to (see Patent Document 1). However, in this method, it is necessary to provide an ultraviolet irradiation device in an existing process, and in order to achieve an integrated illuminance that is effective in preventing a decrease in peel strength, a coating speed limit or a large scale is required. The problem that a suitable ultraviolet irradiation equipment becomes necessary arises.

Japanese Patent No. 3514582

  Therefore, the object of the present invention is to provide a peel strength with respect to the adhesive surface of the heavy-side release processing layer formed on one surface of the base material even if a special manufacturing apparatus is not provided during the manufacturing process. An object of the present invention is to provide a release liner capable of suppressing or preventing change with time, and a double-sided pressure-sensitive adhesive tape or sheet using the release liner.

  As a result of intensive studies to achieve the above object, the present inventors have not used an organohydrogenpolysiloxane, and have used an ionizing radiation-curable cationic curable silicone release agent, When the treatment layer is formed, it is possible to suppress or prevent a change with time in the peel strength of the heavy surface side release treatment layer, and the peel strength with respect to the adhesive surface of the heavy surface side release treatment layer is less than the light surface side release. It has been found that a state where the peel strength with respect to the adhesive surface of the mold treatment layer is larger can be effectively maintained, and the occurrence of the tearing phenomenon can be suppressed or prevented.

More specifically, a thermosetting silicone release agent has been conventionally used as a release agent for forming the heavy-side release layer, and this thermosetting silicone release agent is a heat addition type. The heavy-side release layer is an organohydrogen having a vinyl group (SiCH = CH ₂ group) bonded to a silicon atom and a hydrogen atom (SiH group) bonded to a silicon atom. Polysiloxane is thermally cured under a platinum catalyst to form a cured film. In this case, in order for the film to be sufficiently cured, it is important that the ratio of SiH groups to SiCH═CH ₂ groups is 1 to 1.2 and the SiH groups are excessive. SiH groups remain in the film. Since the remaining SiH groups act chemically or pseudochemically on the pressure-sensitive adhesive layer, the peel strength is affected by the remaining amount of SiH groups. Since this SiH group can be lost by reacting with water in the atmosphere or the like, the phenomenon that the amount of SiH group decreases and the peel strength decreases with time appears. Therefore, in the present invention, an ionizing radiation curable cationic curable silicone-based release agent that does not use an organohydrogenpolysiloxane having a SiH group is used as a release agent for forming the heavy surface side release treatment layer. By using it, the problem of decrease in peel strength over time can be solved, and a significant difference in peel strength between the light side release layer and the heavy side release layer can be effectively maintained, and the crying phenomenon It has been found that the occurrence of can be suppressed or prevented. The present invention has been completed based on these findings.

That is, the present invention is a release liner having a configuration in which a release treatment layer is formed on both surfaces of a substrate, and the release treatment layer on one side of the substrate is formed of a thermosetting silicone release agent. And the release treatment layer on the other surface side of the substrate is formed of an ultraviolet curable silicone release agent, and the release treatment layer formed of the thermosetting silicone release agent is peeled from the adhesive surface. Used as a release treatment layer on the side having a low strength, and a release treatment layer formed with an ultraviolet curable silicone release agent is used as a release treatment layer on the side having a high peel strength with respect to the adhesive surface. The release treatment layer formed with the silicone release agent has a peel strength (peel angle: 180 °, tensile speed: 300 mm / min, 23 ° C., 50% RH) with respect to the adhesive surface of 0.1 to 1.0 N / 50 mm. so And the reduction rate of the peel strength when left for 21 days in an environment of a temperature of 60 ° C. and a humidity of 90% RH is 50% or less, and is formed by a thermosetting silicone release agent. Peeling strength (peeling angle: 180 °, tensile speed: 300 mm / min, 23 ° C, 50% RH) with respect to the adhesive surface in the release treatment layer is 0.01 to 0.3 N / 50 mm. Provide a liner.

  The present invention is also a double-sided pressure-sensitive adhesive tape or sheet having a configuration in which the adhesive surfaces on both sides are protected by a single release liner, wherein the release liner is used as the release liner. It is the double-sided adhesive tape or sheet characterized.

  According to the release liner of the present invention, even if a special process requiring a special manufacturing apparatus is not performed, the release from the adhesive surface of the heavy-side release processing layer formed on one surface of the substrate is performed. It is possible to suppress or prevent the strength change with time. Therefore, the release liner of the present invention can be peeled off from the pressure-sensitive adhesive surface of the heavy-side release treatment layer formed on one surface of the base material even if a special treatment requiring a special manufacturing apparatus is not performed. It is possible to effectively maintain a state in which the strength is larger than the peel strength with respect to the adhesive surface of the light-side mold release treatment layer formed on the other surface of the substrate. Therefore, the double-sided pressure-sensitive adhesive tape or sheet prepared using the release liner of the present invention can be peeled between the light-side release processing layer and the pressure-sensitive adhesive layer when used, Generation | occurrence | production of the phenomenon (what is called "crying separation phenomenon") which peels between a mold release process layer and an adhesive layer can be prevented effectively.

[Release liner]
The release liner of the present invention has a release treatment layer (sometimes referred to as a “thermosetting silicone release treatment layer”) formed with a thermosetting silicone release agent on one surface of a substrate. And a release treatment layer (sometimes referred to as an “ionization radiation curable silicone release treatment layer”) formed of an ionizing radiation curable silicone release agent on the other surface of the substrate. is doing. Thus, the release liner has a release treatment layer formed on both sides of the substrate, and one of the release treatment layers on both sides is an ionizing radiation curable silicone release treatment. By using this ionizing radiation curable release layer as a heavy-side release layer (a release layer having a higher peel strength with respect to the adhesive surface), It is possible to suppress or prevent a change in peel strength with respect to the adhesive surface of the surface-side release treatment layer over time.

(Thermosetting silicone release agent)
The thermosetting silicone release agent is not particularly limited as long as it is a type of silicone release agent that is cured by heat, but is cured by addition reaction type crosslinking (curing reaction) by heat to form a peelable film. A type of heat addition reaction type silicone release agent can be suitably used. The thermosetting silicone release agent can be used alone or in combination of two or more.

  The heat addition reaction type silicone release agent includes a polysiloxane polymer having a group reactive to a group having a Si-H bond in the molecule, and a silicon atom in the molecule. A heat addition reaction type polysiloxane release agent containing a polysiloxane polymer having hydrogen atoms can be used. The “Si—H bond” means “a bond between a silicon atom (Si) and a hydrogen atom (H)”.

  In the polysiloxane polymer having a group reactive to a group having Si—H bond in the molecule, examples of the group having reactivity to the group having Si—H bond include vinyl. And alkenyl groups such as a hexenyl group and the like. The alkenyl group preferably has two or more in the molecule of the polysiloxane polymer having a group reactive to the group having a Si—H bond in the molecule. Further, in the polysiloxane polymer having hydrogen atoms bonded to silicon atoms in the molecule, it is preferable that the molecule has two or more hydrogen atoms bonded to silicon atoms. Therefore, as a heat addition reaction type polysiloxane release agent, a polysiloxane polymer having two or more alkenyl groups in the molecule and two or more hydrogen atoms bonded to silicon atoms in the molecule are used. A polysiloxane release agent containing the polysiloxane polymer is suitable.

  In a polysiloxane polymer having two or more alkenyl groups in the molecule, the alkenyl group is usually a silicon atom (for example, a terminal silicon atom, Directly bonded to the silicon atom in the main chain). Therefore, as the polysiloxane polymer having two or more alkenyl groups in the molecule, a polysiloxane polymer having two or more alkenyl groups directly bonded to silicon atoms in the molecule is suitable. Can be used. Examples of the polysiloxane polymers forming the main chain or the skeleton include polyalkylalkylsiloxane polymers such as polydimethylsiloxane polymers, polydiethylsiloxane polymers, and polymethylethylsiloxane polymers, and polyalkyl polymers. In addition to the arylsiloxane polymer, a copolymer [for example, poly (dimethylsiloxane-diethylsiloxane)] in which a plurality of silicon atom-containing monomer components are used may be used, and a polydimethylsiloxane polymer is preferable.

  On the other hand, in a polysiloxane polymer having two or more hydrogen atoms bonded to silicon atoms in the molecule, the silicon atoms bonded to hydrogen atoms are the silicon atoms in the main chain and the side chains. Any of silicon atoms may be used. As the polysiloxane polymer having two or more hydrogen atoms bonded to silicon atoms in the molecule, a polydimethylhydrogensiloxane polymer [eg, poly (dimethylsiloxane-methylsiloxane)] is preferable. is there. In the thermal addition reaction type polysiloxane release agent, a polysiloxane polymer having two or more hydrogen atoms bonded to silicon atoms in the molecule has a function as a crosslinking agent.

  The amount of the polysiloxane polymer having two or more hydrogen atoms bonded to silicon atoms in the molecule is not particularly limited, and should be appropriately selected according to the film curability, peel strength, and the like. Can do. Specifically, a polysiloxane polymer having two or more hydrogen atoms bonded to silicon atoms in the molecule is bonded to silicon atoms in the molecule in order to sufficiently cure the film. When the number of moles of silicon atoms to which hydrogen atoms are bonded in a polysiloxane polymer having two or more hydrogen atoms (that is, silicon atoms of Si—H bonds) is referred to as “number of moles (X)” And the number of moles of alkenyl groups in the polysiloxane polymer having two or more alkenyl groups in the molecule (sometimes referred to as “number of moles (Y)”) is the number of moles (X) > The number of moles (Y) is preferably used, and the number of moles (X) / number of moles (Y) is usually 1.0 to 2.0 (preferably 1.2 to 1.6). Used in

  A polysiloxane polymer having two or more alkenyl groups in the molecule is cured with a polysiloxane polymer (crosslinking agent) having two or more hydrogen atoms bonded to silicon atoms in the molecule. In this case, a catalyst can be used. As the catalyst, a platinum-based catalyst (for example, a platinum-based compound such as platinum fine particles, chloroplatinic acid or a derivative thereof) can be suitably used. The amount of the catalyst used is not particularly limited. For example, the catalyst may be selected from a range of 0.1 to 1000 ppm (preferably 1 to 100 ppm) based on a polysiloxane polymer having two or more alkenyl groups in the molecule. it can.

  The thermal addition reaction type polysiloxane release agent is composed of the above-described constituent components (for example, a polysiloxane polymer having two or more alkenyl groups in the molecule, and two hydrogen atoms bonded to silicon atoms in the molecule). The above-described polysiloxane polymer, and if necessary, a catalyst and various additives) can be prepared by mixing with an organic solvent as necessary. The heat addition reaction type polysiloxane release agent can be used in a state where a polymer component such as a polysiloxane polymer is dissolved in an organic solvent. The heat addition reaction type polysiloxane release agent has known or commonly used additives [for example, fillers, antistatic agents, antioxidants, ultraviolet absorbers, plasticizers, colorants (dyes, pigments, etc.)]. You may mix | blend suitably.

  As such a heat addition reaction type polysiloxane release agent, for example, trade name “KS-847T” (manufactured by Shin-Etsu Chemical Co., Ltd.), trade name “KS-774” (manufactured by Shin-Etsu Chemical Co., Ltd.), trade name “KS-” 841 "(manufactured by Shin-Etsu Chemical Co., Ltd.) is commercially available.

(Ionizing radiation curable silicone release agent)
The ionizing radiation curable silicone release agent is not particularly limited as long as it is a type of silicone release agent that is cured by ionizing radiation (α rays, β rays, γ rays, neutron rays, electron beams, ultraviolet rays, etc.). However, an ultraviolet curable silicone release agent of a type that is cured by crosslinking (curing reaction) by ultraviolet irradiation to form a peelable film can be suitably used. The ionizing radiation curable silicone release agent can be used alone or in combination of two or more.

  The ultraviolet curable silicone release agent is not particularly limited as long as it is a silicone release agent that can be cured by ultraviolet irradiation, and various curing types (curing mechanisms) can be used. Examples of such a curing type include a cationic polymerization type that cures by cationic polymerization, a radical polymerization type that cures by radical polymerization, a radical addition type that cures by radical addition polymerization, and a hydrosilylation reaction type that cures by hydrosilylation reaction. Can be mentioned. As the curing type of the ultraviolet curable silicone release agent, a cationic polymerization type is particularly suitable. That is, as the ultraviolet curable silicone release agent, a cationic polymerizable ultraviolet curable silicone release agent can be suitably used.

  In the cationic polymerizable ultraviolet curable silicone release agent, one or two epoxy functional silicone polymer components in which one or two or more epoxy functional organic groups are introduced into the polysiloxane component of the main chain are used. Used in combination with more than one species. The epoxy functional organic group may be directly bonded to the main chain or side chain silicon atom in the polysiloxane component and may be a divalent group (for example, a divalent organic group such as an alkylene group or an alkyleneoxy group). Etc.). It is important that at least two epoxy functional organic groups be introduced into the main chain polysiloxane component.

  Specifically, in the cationic polymerizable UV curable silicone release agent, the epoxy functional organic group includes glycidyl group, glycidoxy group (glycidyloxy group), 3,4-epoxycyclohexyl group, 2,3-epoxycyclopentyl. Groups and the like.

  The epoxy-functional silicone polymer component is obtained by, for example, adding olefinic epoxy monomers such as 4-vinylcyclohexene oxide, allyl glycidyl ether, and 7-epoxy-1-octene to platinum polymer polymethylhydrogensiloxane. It can be obtained by an addition reaction using a catalyst such as a compound. The epoxy functional silicone polymer component may have a linear or branched chain form, or a mixture thereof.

  In the cationic polymerizable ultraviolet curable silicone release agent, an onium salt ultraviolet cleavage initiator (onium salt photopolymerization initiator) can be used as an ultraviolet cleavage initiator (photopolymerization initiator). The onium salt-based ultraviolet-cleavable initiator can be used alone or in combination of two or more.

  Examples of the onium salt-based UV-cleavable initiator include onium salt photoinitiators described in JP-A-6-32873 and onium salt-based photoinitiators described in JP-A 2000-281965. Onium salt photoinitiators described in JP-A-11-228702 and onium salt photoinitiators described in JP-B-8-26120. Examples of such onium salt-based ultraviolet-cleavable initiators include diaryliodonium salts, triarylsulfonium salts, triarylselenonium salts, tetraarylphosphonium salts, aryldiazonium salts, and the like. As the onium salt-based ultraviolet cleavage type initiator, a diaryliodonium salt is suitable.

More specifically, for example, as diaryl iodonium salt, “Y ₂ I ⁺ X ⁻ (Y represents an aryl group which may have a substituent. X ⁻ represents a non-nucleophilic and non-nucleophilic group. It is a basic anion.) ”. Examples of non-nucleophilic and non-basic anions of X ⁻ include, for example, SbF ₆ ⁻ , SbCl ₆ ⁻ , BF ₄ ⁻ , [B (C ₆ H ₅ ) ₄ ] ⁻ , [B (C ₆ F ₅ ) ₄ ] ⁻ , [B (C ₆ H ₄ CF ₃ ) ₄ ] ⁻ , [(C ₆ F ₅ ) ₂ BF ₂ ] ⁻ , [C ₆ F ₅ BF ₃ ] ⁻ , [B (C ₆ H ₃ F ₂ ) ₄ ] ⁻ , AsF ₆ ⁻ , PF ₆ ⁻ , HSO ₄ ⁻ , ClO ₄ ^{− and the} like. As such anions, antimony anions and boron anions are suitable.

Examples of the triarylsulfonium salt, triarylselenonium salt, tetraarylphosphonium salt, and aryldiazonium salt include compounds corresponding to the diaryliodonium salt. Specifically, as the triarylsulfonium salt, triarylselenonium salt, tetraarylphosphonium salt, and aryldiazonium salt, “Y ₃ S ⁺ X ⁻ ”, “Y ₃ Se ⁺ X ⁻ ”, and “Y ₄ ”, respectively. P ⁺ X ⁻ ”and“ YN ₂ ⁺ X ⁻ ”(Y and X ⁻ are the same as described above) can be used.

  Onium salt-based UV-cleavable initiators include UV-cleavable initiators containing antimony atoms (antimony-based UV-cleavable initiators), UV-cleavable initiators containing boron atoms (boron-based UV-cleavable initiators) In particular, diaryl iodonium salt-based UV-cleaving initiators containing antimony atoms and diaryl iodonium salt-based UV-cleaving initiators containing boron atoms are preferred.

  Accordingly, examples of the cationic polymerizable UV curable silicone release agent include a polysiloxane component (epoxy functional silicone polymer component) having at least two epoxy functional organic groups in the molecule and an onium salt UV cleavage type. The thing containing at least an initiator etc. are mentioned. In the cationic polymerizable UV curable silicone release agent, the ratio of the onium salt UV cleavable initiator is not particularly limited as long as it is a catalytic amount. For example, for 100 parts by weight of the epoxy functional silicone polymer component It can be selected from the range of 0.1 to 8 parts by weight (preferably 0.3 to 5 parts by weight, more preferably 0.5 to 3 parts by weight).

  The cationic polymerizable UV curable silicone release agent is composed of the above-described constituents (epoxy functional silicone polymer component, onium salt UV-cleavable initiator and various additives as required), and an organic solvent as required. It can prepare by mixing using. The cationic polymerizable ultraviolet curable silicone release agent can be used in a state where a polymer component such as an epoxy functional silicone polymer component is dissolved in an organic solvent. The cationic polymerizable UV curable silicone release agent is appropriately blended with known or conventional additives [for example, fillers, antistatic agents, antioxidants, plasticizers, colorants (dyes, pigments, etc.)]. It may be.

  Examples of such a cationic polymerizable ultraviolet curable silicone release agent include trade name “X-62-7622” (manufactured by Shin-Etsu Chemical Co., Ltd.), trade name “X-62-7629” (manufactured by Shin-Etsu Chemical Co., Ltd.), The product name “X-62-7655” (manufactured by Shin-Etsu Chemical Co., Ltd.), the product name “X-62-7634” (manufactured by Shin-Etsu Chemical Co., Ltd.), the product name “X-62-7658” (manufactured by Shin-Etsu Chemical Co., Ltd.) and the like are commercially available. Has been.

(Base material)
In the release liner of the present invention, a base material (base material for release liner) is used. Such a release liner substrate is not particularly limited, and various substrates such as a plastic substrate, a paper substrate, and a fiber substrate can be used. The release liner substrate may have either a single layer or a laminate. In the release liner substrate, the plastic substrate can be appropriately selected from various plastic substrates, and examples thereof include polyolefin substrates (polyethylene substrates, polypropylene substrates, etc.), polyesters, and the like. Base materials (polyethylene terephthalate base materials, polyethylene naphthalate base materials, polybutylene terephthalate base materials, etc.), polyamide base materials (so-called “nylon” base materials), cellulose base materials (so-called “cellophane” base materials) Base material). Further, as the paper base material, it can be appropriately selected from various paper base materials, for example, Japanese paper, Western paper, high quality paper, glassine paper, kraft paper, Kurpac paper, crepe paper, clay coated paper, A top coat paper, a synthetic paper, etc. are mentioned.

  If necessary, the surface of the release liner substrate can be subjected to various surface treatments such as corona discharge treatment, and various surface treatments such as embossing.

  The thickness of the release liner base material is not particularly limited and can be appropriately selected depending on the application and the like, and can generally be selected from a range of 2 to 200 μm (preferably 25 to 150 μm).

  For the release liner, a thermosetting silicone release treatment layer is formed on one surface of the release liner substrate, and an ionizing radiation curable silicone release treatment layer is formed on the other surface of the release liner substrate. By doing so, it can be manufactured. Specifically, as a method for producing a release liner, a thermosetting silicone release agent is applied to one surface of a release liner substrate in a coating amount so that the thickness after drying or curing becomes a predetermined thickness. Then, after drying or curing by heating to form a thermosetting silicone release treatment layer, an ionizing radiation curable silicone release agent is applied to the other surface of the release liner substrate after drying or curing. After coating with a coating amount of a predetermined thickness and drying by heating as necessary, the film is cured by irradiation with ionizing radiation (such as ultraviolet rays) to form an ionizing radiation curable silicone-based release treatment layer. Examples of the method include forming a release liner.

  The method of heating when drying or curing the thermosetting silicone release agent is not particularly limited, and is a known heating method (for example, a heating method using an electric heater, heating using an electromagnetic wave such as infrared rays). The method can be appropriately selected and employed. Further, the method of irradiating ionizing radiation when curing the ionizing radiation curable silicone release agent is not particularly limited, and a known ionizing radiation irradiation method (for example, an electroded high-pressure mercury lamp, ozoneless) It is possible to appropriately select and employ a UV irradiation method using a known UV lamp such as a lamp, a metal halide lamp, and an electrodeless microwave lamp.

It is important to apply a release agent such as a thermosetting silicone release agent or an ionizing radiation curable silicone release agent on the substrate (release liner substrate) in an appropriate amount. If the amount of the release agent applied is too small, the peel strength (force required for peeling) will be larger than the desired peel strength, causing practical problems. On the other hand, if the amount is too large, the cost will be high and economical. It will be disadvantageous. Appropriate coating amount (solid content) of the release agent includes the type of pressure-sensitive adhesive used, the type of release liner substrate, the type of thermosetting silicone release agent, and the ionizing radiation curable silicone release agent. Although it can select suitably according to a kind etc., it is about 0.01-10 g / m < ² >, for example, Preferably it is 0.05-5 g / m < ² >.

  When applying a release agent (thermosetting silicone release agent, ionizing radiation curable silicone release agent) to the release liner substrate, for example, a direct gravure coater, an offset gravure coater, a roll coater, A known coating apparatus such as a bar coater or a die coater can be appropriately selected and used.

  In the release liner of the present invention, the release strength (release angle: 180 °, tensile speed: 300 mm / min, 23 ° C., 50% RH) with respect to the adhesive surface in each release treatment layer is not particularly limited, but is an ionizing radiation curable type. It is preferable that the silicone-based release treatment layer has a peel strength that can be effectively used as the heavy-side release treatment layer. Specifically, the peeling strength (peeling angle: 180 °, tensile speed: 300 mm / min, 23 ° C., 50% RH) with respect to the adhesive surface in the ionizing radiation curable silicone-based release treatment layer is, for example, 0. It can be appropriately selected from the range of 1 to 1.0 N / 50 mm (preferably 0.15 to 0.8 N / 50 mm, more preferably 0.2 to 0.6 N / 50 mm). At this time, the thermosetting silicone-based release treatment layer has a peel strength that can be effectively used as a light-side release treatment layer (that is, the ionizing radiation-curable silicone release treatment layer). It is important to have a peel strength smaller than the peel strength with respect to the adhesive surface. Examples of the peel strength (peeling angle: 180 °, tensile speed: 300 mm / min, 23 ° C, 50% RH) with respect to the adhesive surface in the thermosetting silicone-based release treatment layer include 0.01 to 0.3 N / 50 mm. It can be suitably selected from the range (preferably 0.03 to 0.2 N / 50 mm, more preferably 0.05 to 0.15 N / 50 mm). In addition, in this invention, the peeling strength with respect to the adhesion surface in each peeling process layer shall be a value measured using brand name "No.502" (Nitto Denko Corporation make; acrylic type double-sided adhesive tape).

  The peel strength with respect to the adhesive surface of each release treatment layer of the release liner is determined as follows. First, after peeling off the yellow release paper of the product name “No. 502” (manufactured by Nitto Denko Corporation; acrylic double-sided adhesive tape, width: 50 mm) to expose the adhesive surface, the adhesive surface was heated to 50 ° C. Bonding to the surface of a predetermined release treatment layer (ionizing radiation curable silicone release layer or thermosetting silicone release treatment layer) of a release liner left in an environment for 1 day using a hand roller Further, the laminate was allowed to stand under a condition of 1 kg under an environment of 100 ° C. for 1 hour and then left to stand for 1 hour in an environment of 23 ° C. and 50% RH. Using an auxiliary plate, the stress was measured when the release liner was peeled off by 50 mm at a tensile speed of 300 mm / min at an angle of 180 ° in an environment of 23 ° C. and 50% RH, and the maximum stress at that time Read value The maximum value of the stress is determined by a peel strength (N / 50mm).

  In particular, in the present invention, since the ionizing radiation curable silicone-based release treatment layer is formed of an ionizing radiation curable silicone-based release agent, the temporal stability of the peel strength with respect to the adhesive surface is excellent. Specifically, in the ionizing radiation curable silicone-based release treatment layer, the reduction rate of the peel strength when left in an environment of a temperature of 60 ° C. and a humidity of 90% RH for 21 days is, for example, 50% or less (0 ˜50%), and can be suitably selected, preferably 40% or less (more preferably 30% or less).

The rate of decrease in peel strength in the ionizing radiation curable silicone-based release treatment layer is determined as follows. First, a release liner left for 21 days in an environment of 60 ° C. and a humidity of 90% RH is used as an aged sample, and the release liner before being left as an initial sample. Next, after peeling off the yellow release paper of the trade name “No. 502” (manufactured by Nitto Denko Corporation; acrylic double-sided adhesive tape, width: 50 mm) to expose the adhesive surface, the adhesive surface is The sample is bonded to the surface of a predetermined release treatment layer (ionizing radiation curable silicone release layer or thermosetting silicone release treatment layer) using a hand roller, and further, in an environment of 50 ° C. 1 After being allowed to stand with a load of 1 kg applied under the conditions of time, and then allowed to stand in an environment of 23 ° C. and 50% RH for 1 hour, the tensile tester was used with an auxiliary plate at 23 ° C. In addition, in a 50% RH environment, the stress when the release liner was peeled off by 50 mm at a peeling angle of 180 ° at a pulling speed of 300 mm / min was measured, and the maximum value of the stress at that time was read. The initial sample Peel strength (W ₀₎ and (N / 50mm).

  In the same manner as described above, the yellow release paper having the trade name “No. 502” (manufactured by Nitto Denko Corporation; acrylic double-sided adhesive tape, width: 50 mm) was peeled off to expose the adhesive surface, and then the adhesive The surface is bonded to the surface of a predetermined release treatment layer (ionizing radiation curable silicone release treatment layer or thermosetting silicone release treatment layer) of the time-lapse sample using a hand roller, and further, 50 ° C. After being allowed to stand under the condition of 1 hour under the condition of 1 kg applied with a load of 1 kg, then left for 1 hour in an environment of 23 ° C. and 50% RH, and then using an auxiliary plate in a tensile tester Then, in an environment of 23 ° C. and 50% RH, the stress when the release liner was peeled off by 50 mm at a peeling angle of 180 ° and a tensile speed of 300 mm / min was measured, and the maximum value of the stress at that time was read, Maximum value of stress The peel strength over time sample (W) (N / 50mm).

Then, by using the peel strength (W ₀ ) of the initial sample and the peel strength (W) of the time-lapse sample, the reduction rate (%) of the peel strength is obtained by the following formula.
Decrease rate of peel strength (%) = [(W ₀ −W) / W ₀ ] × 100

[Double-sided adhesive tape or sheet]
The double-sided pressure-sensitive adhesive tape or sheet of the present invention uses each of the above-mentioned release liners, and each adhesive layer is treated with each release treatment layer (ionizing radiation-curable silicone-type release treatment layer or thermosetting silicone-type release treatment layer). The surface is protected. That is, the double-sided pressure-sensitive adhesive tape or sheet has a structure in which the double-sided pressure-sensitive adhesive surfaces are protected by a single release liner, and the release liner is used as the release liner.

  As long as the double-sided pressure-sensitive adhesive tape or sheet has the above-described configuration, the double-sided pressure-sensitive adhesive tape or sheet (double-sided pressure-sensitive adhesive tape or sheet with a base material) having a structure in which a pressure-sensitive adhesive layer is formed on both sides of the base material, only the pressure-sensitive adhesive layer Any of the double-sided pressure-sensitive adhesive tape or sheet (baseless double-sided pressure-sensitive adhesive tape or sheet) formed from

  Specifically, the double-sided pressure-sensitive adhesive tape or sheet is, for example, in a state where one pressure-sensitive adhesive surface is bonded to an ionizing radiation-curable silicone-based release treatment layer and the other pressure-sensitive adhesive surface is thermosetting silicone-based release treatment. Examples thereof include a double-sided pressure-sensitive adhesive tape wound body having a configuration in which the thermosetting silicone-based release treatment layer is in contact with the layer and wound in a roll shape in a form located on the outside.

(Adhesive layer)
In the double-sided pressure-sensitive adhesive tape or sheet of the present invention, the pressure-sensitive adhesive forming the pressure-sensitive adhesive layer can be appropriately selected from, for example, known pressure-sensitive adhesives. Examples of such adhesives include acrylic adhesives, rubber adhesives, silicone adhesives, vinyl alkyl ether adhesives, polyester adhesives, polyamide adhesives, urethane adhesives, and fluorine adhesives. And a creep property-improving pressure-sensitive adhesive prepared by blending these pressure-sensitive adhesives with a hot-melt resin having a melting point of about 200 ° C. or lower. An adhesive can be used individually or in combination of 2 or more types.

As the pressure-sensitive adhesive, an acrylic pressure-sensitive adhesive can be suitably used. As the acrylic pressure-sensitive adhesive, one or more of (meth) acrylic acid alkyl ester is used as a monomer main component, and a single amount capable of copolymerization with (meth) acrylic acid alkyl ester as required An acrylic pressure-sensitive adhesive having an acrylic polymer (homopolymer or copolymer) in which one or two or more bodies (copolymerizable monomers) are used as a base polymer or a polymer main component may be mentioned. Examples of the (meth) acrylic acid alkyl ester include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, (meth ) Isobutyl acrylate, s-butyl (meth) acrylate, t-butyl (meth) acrylate, pentyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, octyl (meth) acrylate , 2-ethylhexyl (meth) acrylate, isooctyl (meth) acrylate, nonyl (meth) acrylate, isononyl (meth) acrylate, decyl (meth) acrylate, isodecyl (meth) acrylate, (meth) acrylic acid Undecyl, dodecyl (meth) acrylate, tridecyl (meth) acrylate, Such as tetradecyl (meth) acrylate, pentadecyl (meth) acrylate, hexadecyl (meth) acrylate, heptadecyl (meth) acrylate, octadecyl (meth) acrylate, nonadecyl (meth) acrylate, eicosyl (meth) acrylate ( And (meth) acrylic acid alkyl ester [preferably (meth) acrylic acid C _4-12 alkyl ester].

  In the acrylic pressure-sensitive adhesive, the copolymerizable monomer is not particularly limited, and can be appropriately selected from known copolymerizable monomers. Examples of the copolymerizable monomer include carboxyl group-containing monomers such as (meth) acrylic acid, itaconic acid, maleic acid, fumaric acid, crotonic acid, and isocrotonic acid, or anhydrides thereof; vinyl esters such as vinyl acetate; Cyano group-containing monomers such as acrylonitrile and methacrylonitrile; aromatic vinyl compounds such as styrene and substituted styrene can be preferably used.

  In the acrylic polymer, the ratio of the (meth) acrylic acid alkyl ester is not particularly limited as long as the (meth) acrylic acid alkyl ester is used as the main monomer component, and various physical properties of the pressure-sensitive adhesive layer It can select suitably according to adhesiveness etc.

  For pressure-sensitive adhesives (particularly acrylic pressure-sensitive adhesives), if necessary, tackifiers (for example, petroleum-based resins, terpene-based resins, rosin-based resins, chromanindene-based resins, phenol-based resins, etc.), crosslinking agents ( For example, isocyanate crosslinking agents, epoxy crosslinking agents, metal chelate crosslinking agents, metal salt crosslinking agents, peroxide crosslinking agents, melamine crosslinking agents, amino crosslinking agents, coupling agent crosslinking agents), oxidation Various known additives such as an inhibitor, an ultraviolet absorber, an anti-aging agent, various stabilizers, a plasticizer, a softener, a filler, and a colorant may be added.

  It does not restrict | limit especially as thickness of an adhesive layer, It is preferable that it is 10-100 micrometers. The pressure-sensitive adhesive layer may have either a single layer form or a laminated form.

(Base material)
In the double-sided pressure-sensitive adhesive tape or sheet, the base material (double-sided pressure-sensitive adhesive tape or sheet base material) is not particularly limited, and is appropriately selected from known base materials as a base material for adhesive sheets such as pressure-sensitive adhesive tapes or sheets. be able to. Specifically, as the double-sided pressure-sensitive adhesive tape or sheet base material, for example, plastic base materials such as films and sheets made of various plastic materials (for example, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polyethylene, polypropylene, etc.) Fiber base materials (woven fabrics, nonwoven fabrics, felts, nets, etc.) made from various fibers such as Manila hemp, rayon fibers, polyester fibers and pulp fibers; paper base materials such as Japanese paper and synthetic paper; rubber sheets And rubber base materials such as foam sheets, metal base materials such as aluminum foil, and laminates thereof. The double-sided pressure-sensitive adhesive tape or sheet base material may have either a single layer form or a laminated form.

  As the double-sided pressure-sensitive adhesive tape or sheet base material, a plastic film and a nonwoven fabric are preferable from the viewpoints of strength, processability, dimensional stability, and the like.

  The thickness of the double-sided pressure-sensitive adhesive tape or sheet base material is not particularly limited and can be appropriately selected depending on the application and the like, and is generally about 2 to 200 μm.

  In addition, in the double-sided pressure-sensitive adhesive tape or sheet with a substrate, the pressure-sensitive adhesive layers formed on both surfaces of the double-sided pressure-sensitive adhesive tape or sheet base material may be formed of the same pressure-sensitive adhesive, or are formed of different pressure-sensitive adhesives. It may be. Moreover, the thickness of each adhesive layer may be the same, and may differ.

  The method for producing the double-sided pressure-sensitive adhesive tape or sheet is not particularly limited, and a known or commonly used method for producing a double-sided pressure-sensitive adhesive tape or sheet can be appropriately employed. Specifically, when the double-sided pressure-sensitive adhesive tape or sheet is, for example, a substrate-less double-sided pressure-sensitive adhesive tape or sheet wound in a roll shape, as a method for producing the double-sided pressure-sensitive adhesive tape or sheet, for example, a release liner As described above, a thermosetting silicone-based release treatment layer is formed on one surface of the release liner substrate, and an ionizing radiation-curable silicone release treatment layer is formed on the other surface. Using a release liner, an adhesive is applied on one release treatment layer of the release liner in a coating amount so that the thickness after drying or curing becomes a predetermined thickness, and dried or cured to form an adhesive layer. Thereafter, the exposed adhesive surface is brought into contact with the surface of the other release treatment layer and the thermosetting silicone release treatment layer is positioned on the outside, and the method is wound in a roll.

  On the other hand, when the double-sided pressure-sensitive adhesive tape or sheet is a double-sided pressure-sensitive adhesive tape or sheet with a substrate, as a method for producing the double-sided pressure-sensitive adhesive tape or sheet, for example, Is applied in a coating amount so that the thickness after drying or curing each becomes a predetermined thickness and dried or cured to form a pressure-sensitive adhesive layer, and then on one pressure-sensitive adhesive layer of the double-sided pressure-sensitive adhesive tape or sheet substrate, A thermosetting silicone release treatment layer is formed on one surface of the release liner substrate so that the pressure-sensitive adhesive layer and one release treatment layer of the release liner are in contact with each other, and on the other surface. A release liner having a configuration in which an ionizing radiation curable silicone-based release treatment layer is formed is bonded, and the exposed adhesive surface is in contact with the other release treatment layer surface and is thermosetting. Silicone release A method of winding in a roll shape so that the treatment layer is located on the outside, or a release liner, a thermosetting silicone release treatment layer is formed on one side of the release liner substrate, and the other side A release liner having a structure in which an ionizing radiation-curable silicone-based release treatment layer is formed on the adhesive layer, and the pressure-sensitive adhesive is dried or cured on one release treatment layer of the release liner. Is applied in a coating amount with a predetermined thickness and dried or cured to form an adhesive layer, and then a double-sided adhesive tape or a substrate for a sheet is laminated on the adhesive layer and laminated, and then On the double-sided pressure-sensitive adhesive tape or sheet substrate, the pressure-sensitive adhesive is applied in a coating amount so that the thickness after drying or curing becomes a predetermined thickness, dried or cured to form a pressure-sensitive adhesive layer, and then the pressure-sensitive adhesive exposed. The surface in contact with the surface of the other release layer One heat-curable silicone type releasably treated layer and a method of winding into a roll so as to be positioned on the outer side.

  In forming the pressure-sensitive adhesive layer, crosslinking treatment can be performed by heating or the like, or polymerization can be performed by irradiation with electromagnetic waves (such as ultraviolet rays) as necessary. The pressure-sensitive adhesive layer can also be formed using a melt extrusion method.

  Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited to these examples.

(Reference Example 1: Preparation Example 1 of a light-side release processing layer)
As a silicone release agent, trade name “KS-847T” (manufactured by Shin-Etsu Chemical Co., Ltd .; thermosetting polydimethylsiloxane): 100 parts by weight of platinum catalyst (trade name “CAT-PL-50T” Shin-Etsu Chemical) Incorporated 1 part by weight of Co., Ltd., adjusted to a solid content concentration of 1.0% by weight with heptane, and may be referred to as a thermosetting silicone release agent ("light side release agent A"). Prepared).

The light-side release agent A was applied to one surface of a 75 μm-thick polyethylene terephthalate film (trade name “Lumirror S-27” manufactured by Toray Industries, Inc.) using a Mayer bar (# 18), and then 130 Peeling with a release treatment layer formed on one side after drying or curing at 60 ° C. for 60 seconds to form a release treatment layer (sometimes referred to as “light-side release treatment layer A”) A liner was obtained. The application amount of the light-side release agent A was 1.0 g / m ² .

Example 1
As a silicone release agent, trade name “X-62-7622” (manufactured by Shin-Etsu Chemical Co., Ltd .; UV-curable polydimethylsiloxane): 100 parts by weight of UV-cleavable initiator (trade name “CAT7605” Shin-Etsu Chemical) Incorporated 1 part by weight of Co., Ltd., adjusted to a solid content concentration of 1.0% by weight with heptane, sometimes referred to as UV curable silicone release agent ("heavy surface release agent A") Prepared).

On the surface of the release liner obtained in Reference Example 1 on the side where the light side release layer A is not formed, the heavy surface side release agent A is applied with a Meyer bar (# 18), and then 120 Heptane was volatilized by drying at 90 ° C. for 90 seconds to obtain a release agent film. Next, using a high-pressure mercury lamp (illuminance 90 mW / cm ² ), the release agent film is exposed and cured so that the irradiation rate is 200 mJ / cm ² at a coating speed of 4 m / min. After forming a release treatment layer (sometimes referred to as “heavy surface side release treatment layer A”), it is further allowed to stand (age) for 1 day under an environment temperature of 50 ° C. to release the release treatment layer on both sides. A release liner in which was formed was obtained. In addition, the coating amount of the heavy surface side release agent A was 1.0 g / m ² .

(Example 2)
As a silicone release agent, trade name “X-62-7629” (manufactured by Shin-Etsu Chemical Co., Ltd .; UV-curable polydimethylsiloxane): 100 parts by weight of UV-cleavable initiator (trade name “CAT7605” Shin-Etsu Chemical) 1 part by weight of Co., Ltd. is blended, and the solid content concentration is adjusted to 1.0% by weight with heptane, which may be referred to as an ultraviolet curable silicone release agent ("heavy surface release agent B"). Prepared).

On the surface of the release liner obtained in Reference Example 1 where the light side release layer A is not formed, the heavy surface side release agent B is applied with a Mayer bar (# 18), and then 120 Heptane was volatilized by drying at 90 ° C. for 90 seconds to obtain a release agent film. Next, using a high-pressure mercury lamp (illuminance 90 mW / cm ² ), the release agent film is exposed and cured so that the irradiation rate is 200 mJ / cm ² at a coating speed of 4 m / min. After forming a release treatment layer (sometimes referred to as “heavy surface release treatment layer B”), the mold is left to stand (aging) for 1 day under an environment temperature of 50 ° C. A release liner in which was formed was obtained. In addition, the coating amount of the heavy surface side release agent B was 1.0 g / m ² .

(Example 3)
As a silicone release agent, trade name “X-62-7629” (manufactured by Shin-Etsu Chemical Co., Ltd .; UV-curable polydimethylsiloxane): 90 parts by weight, trade name “X-62-7655” (Shin-Etsu Chemical Co., Ltd.) Company: UV curable polydimethylsiloxane mixed with 10 parts by weight of UV curable polydimethylsiloxane: 100 parts by weight of UV cleavable initiator (trade name “CAT7605” manufactured by Shin-Etsu Chemical Co., Ltd.) ) In an amount of 1.0 part by weight, adjusted to a solid content concentration of 1.0% by weight with heptane, and an ultraviolet curable silicone release agent (sometimes referred to as “heavy surface side release agent C”). Prepared.

On the surface of the release liner obtained in Reference Example 1 where the light side release layer A is not formed, the heavy surface side release agent C is applied with a Mayer bar (# 18), and then 120 Heptane was volatilized by drying at 90 ° C. for 90 seconds to obtain a release agent film. Next, using a high-pressure mercury lamp (illuminance 90 mW / cm ² ), the release agent film is exposed and cured so that the irradiation rate is 200 mJ / cm ² at a coating speed of 4 m / min. After forming a release treatment layer (sometimes referred to as “heavy surface release treatment layer C”), it is further left to stand (aging) for 1 day under an environment temperature of 50 ° C., and the release treatment layer is formed on both sides. A release liner in which was formed was obtained. In addition, the coating amount of the heavy surface side release agent C was 1.0 g / m ² .

(Comparative Example 1)
As a silicone release agent, trade name “KS-774” (manufactured by Shin-Etsu Chemical Co., Ltd .; thermosetting polydimethylsiloxane): 100 parts by weight of platinum catalyst (trade name “CAT-PL-3”, Shin-Etsu Chemical) 0.7 parts by weight of Co., Ltd. is blended and adjusted with heptane to a solid content concentration of 1.0% by weight, and referred to as a thermosetting silicone release agent ("heavy surface release agent D"). Prepared).

After the heavy side release agent D was applied to the surface of the release liner obtained in Reference Example 1 on the side where the light side release layer A was not formed, using a Meyer bar (# 18), 130 After drying or curing at 60 ° C. for 60 seconds to form a heavy-surface-side release treatment layer (sometimes referred to as “heavy-surface-side release treatment layer D”), an environment temperature of 50 ° C. After leaving for 1 day (aging), a release liner having a release treatment layer formed on both sides was obtained. In addition, the coating amount of the heavy surface side release agent D was 1.0 g / m ² .

(Comparative Example 2)
As a silicone release agent, trade name “X-62-2087” (manufactured by Shin-Etsu Chemical Co., Ltd .; thermosetting polydimethylsiloxane): 100 parts by weight of platinum catalyst (trade name “CAT-PL-50T”) 1 part by weight of Shin-Etsu Chemical Co., Ltd. is blended and adjusted with heptane so that the solid content concentration becomes 1.0% by weight, and is called a thermosetting silicone release agent (“heavy surface release agent E”). Prepared).

After the heavy-side release agent E was applied to the surface of the release liner obtained in Reference Example 1 on the side where the light-side release processing layer A was not formed using a Mayer bar (# 18), 130 After drying or curing at 60 ° C. for 60 seconds to form a heavy-surface-side release treatment layer (sometimes referred to as “heavy-surface-side release treatment layer E”), an environment temperature of 50 ° C. After leaving for 1 day (aging), a release liner having a release treatment layer formed on both sides was obtained. In addition, the coating amount of the heavy surface side release agent E was 1.0 g / m ² .

(Comparative Example 3)
As a silicone release agent, trade name “KS-841” (manufactured by Shin-Etsu Chemical Co., Ltd .; thermosetting polydimethylsiloxane): 100 parts by weight of platinum-based catalyst (trade name “CAT-PL-50T” Shin-Etsu Chemical) 1 part by weight of Co., Ltd. is blended and adjusted to a solid content concentration of 1.0% by weight with heptane, sometimes referred to as a thermosetting silicone release agent (“heavy surface release agent F”). Prepared).

After the heavy surface side release agent F was applied by Meyer bar (# 18) to the surface of the release liner obtained in Reference Example 1 on which the light-side release layer A was not formed, 130 After drying or curing at 60 ° C. for 60 seconds to form a heavy-surface-side release treatment layer (sometimes referred to as “heavy-surface-side release treatment layer F”), it is further subjected to an environmental temperature of 50 ° C. After leaving for 1 day (aging), a release liner having a release treatment layer formed on both sides was obtained. In addition, the coating amount of the heavy surface side release agent F was 1.0 g / m ² .

(Comparative Example 4)
As a silicone release agent, trade name “KS-839L” (manufactured by Shin-Etsu Chemical Co., Ltd .; thermosetting polydimethylsiloxane): 100 parts by weight of platinum catalyst (trade name “CAT-PL-50T” Shin-Etsu Chemical) 1 part by weight of Co., Ltd. is blended and adjusted with heptane so that the solid content concentration is 1.0% by weight, and may be referred to as a thermosetting silicone release agent (“heavy surface release agent G”). Prepared).

After the heavy surface side release agent G was applied to the surface of the release liner obtained in Reference Example 1 on the side where the light surface side release treatment layer A was not formed with a Mayer bar (# 18), 130 After drying or curing at 60 ° C. for 60 seconds to form a heavy-surface-side release treatment layer (sometimes referred to as “heavy-surface-side release treatment layer G”), a further condition at an environmental temperature of 50 ° C. After leaving for 1 day (aging), a release liner having a release treatment layer formed on both sides was obtained. In addition, the coating amount of the heavy surface side release agent G was 1.0 g / m ² .

(Evaluation)
With respect to the release liners obtained in Examples 1 to 3, Comparative Examples 1 to 4, and Reference Example 1, the following measurement method or evaluation method was used to measure the peel strength against the adhesive surface in the release treatment layer and the reduction rate of the peel strength. The residual adhesive strength and the presence or absence of peeling abnormality were measured or evaluated. The evaluation results are shown in Table 1. The release liner obtained in Reference Example 1 was measured or evaluated after being allowed to stand (age) for 1 day under an environment temperature of 50 ° C.

(Measurement method 1 of peel strength)
First, a release liner left for 21 days (3 weeks) in an environment of 60 ° C. and a humidity of 90% RH is used as a time-lapse sample, and a release liner before the release (release liner after aging) is used as an initial sample.

Next, the product name “No. 502” (manufactured by Nitto Denko Corporation; acrylic double-sided adhesive tape, width: 50 mm; referred to as “adhesive tape A” in the table) is used as the adhesive tape, and the yellow release paper of the adhesive tape is used. Is peeled off to expose the pressure-sensitive adhesive surface, and then the pressure-sensitive adhesive surface is subjected to a predetermined release treatment layer of the initial sample or the time-lapse sample [for the release liners obtained in Examples 1 to 3 and Comparative Examples 1 to 4, About the release liner obtained by the heavy surface side mold release treatment layer (heavy surface mold release treatment layers A to G) and Reference Example 1, a hand roller is used on the surface of the light side mold release treatment layer A]. Bonding was further performed by allowing the substrate to stand under a load of 1 kg under an environment of 100 ° C. for 1 hour, and then standing for 1 hour in an environment of 23 ° C. and 50% RH. At 23 ° C with an auxiliary plate Measure the stress when the release liner was peeled 50 mm at a pulling speed of 300 mm / min at a peeling angle of 180 ° under an environment of 50% RH, and read the maximum value of the stress at that time. The peel strength (W ₀ ) (N / 50 mm) of the initial sample, or the peel strength (W) (N / 50 mm) of the sample over time.

(Measurement method 1 of peel rate reduction rate)
Using the peel strength (W ₀ ) of the initial sample measured by the peel strength measurement method and the peel strength (W) of the time-lapse sample, the reduction rate (%) of the peel strength is obtained by the following equation.
Decrease rate of peel strength (%) = [(W ₀ −W) / W ₀ ] × 100

(Measurement method of residual adhesive strength)
In the same manner as in the measurement method 1 of the peel strength, first, a release liner left for 21 days in an environment of 60 ° C. and a humidity of 90% RH is used as a time-lapse sample, and the release liner before being left (that is, after aging) The release liner is used as the initial sample. Next, the product name “No. 31B” (manufactured by Nitto Denko Corporation; pressure-sensitive adhesive tape having a polyester base material, width: 19 mm) is used as the initial sample or time-lapse sample, and the pressure-sensitive adhesive surface of the pressure-sensitive adhesive tape is the initial sample or time-lapse sample. A predetermined release treatment layer [for the release liners obtained in Examples 1 to 3 and Comparative Examples 1 to 4, heavy surface side release treatment layers (heavy surface release treatment layers A to G), Reference Example The release liner obtained in 1 was bonded using a hand roller in a form in contact with the surface of the light-side release processing layer A], and left for 1 day in a 50 ° C. environment. Thereafter, the adhesive tape (trade name “No. 31B”) was peeled off from the initial sample or the time-lapsed sample, and then the adhesive tape was bonded to a stainless steel plate using a hand roller, and further allowed to stand at room temperature for 30 minutes, and then pulled. Using an auxiliary plate, measure the stress when the adhesive tape was peeled off 50 mm at a tensile rate of 300 mm / min at an angle of 180 ° under an environment of 23 ° C. and 50% RH. The average value of the stress is read, and the average value of the stress is defined as the peel strength (F) (N / 50 mm).

Further, a trade name “No. 31B” (manufactured by Nitto Denko Corporation; adhesive tape having a polyester base material, width: 19 mm) was bonded to a stainless steel plate using a hand roller, and was further left at room temperature for 30 minutes. After that, using a tensile tester, the stress when the adhesive tape was peeled off by 50 mm at a tensile speed of 300 mm / min at an angle of 180 ° in an environment of 23 ° C. and 50% RH was measured using an auxiliary plate. Then, the average value of the stress at that time is read, and the average value of the stress is defined as the peel strength (F ₀ ) (N / 50 mm) of the blank.

Then, using the peel strength (F) and the blank peel strength (F ₀ ), the residual adhesive force (%) is calculated by the following equation.
Residual adhesive strength (%) = (F / F ₀ ) × 100

(Measurement method 2 of peel strength)
In the same manner as in the measurement method 1 of the peel strength, first, a release liner left for 21 days in an environment of 60 ° C. and a humidity of 90% RH is used as a time-lapse sample, and the release liner before being left (that is, after aging) The release liner is used as the initial sample.

Next, the product name “No. 5000NS” (manufactured by Nitto Denko Corporation; acrylic double-sided adhesive tape, width: 50 mm; referred to as “adhesive tape B” in the table) or the product name “KSR-532P” (Nitto) as the adhesive tape. Made by Denko Co., Ltd .; acrylic double-sided pressure-sensitive adhesive tape, width: 50 mm; referred to as “pressure-sensitive adhesive tape C” in the table), the release surface of the pressure-sensitive adhesive tape was peeled off to expose the pressure-sensitive adhesive surface. , A predetermined release treatment layer of an initial sample or a time-lapse sample [for the release liners obtained in Examples 1 to 3 and Comparative Examples 1 to 4, a double-side release treatment layer (multi-side release treatment layer A) G) and the release liner obtained in Reference Example 1 were bonded to the surface of the light-side release layer A] using a hand roller, and further 1 kg under the condition of 50 ° C. for 1 day. Apply a load of After being left to stand in a state of bonding, after being left for 1 hour in an environment of 23 ° C. and 50% RH, it was 180 ° in an environment of 23 ° C. and 50% RH using an auxiliary plate with a tensile tester. The stress when the release liner was peeled off by 50 mm at a peeling speed of 300 mm / min was measured, the maximum value of the stress at that time was read, and the maximum value of the stress was determined as the peel strength (W ₀ ) of the initial sample. (N / 50 mm) or the peel strength (W) of the sample over time (N / 50 mm).

(Measurement method 2 of decrease rate of peel strength)
Similar to the measurement method 1 of the peel strength reduction rate, using the peel strength (W ₀ ) of the initial sample measured by the peel strength measurement method 2 and the peel strength (W) of the sample over time, the following formula Thus, the reduction rate (%) of the peel strength is obtained.
Decrease rate of peel strength (%) = [(W ₀ −W) / W ₀ ] × 100

(Evaluation method for the presence or absence of peeling abnormality)
About the release liner obtained by Examples 1-3 and Comparative Examples 1-4, the presence or absence of peeling abnormality is evaluated. First, in the same manner as in peel strength measurement method 1 and the like, the release liner is left to stand for 21 days in an environment of 60 ° C. and humidity 90% RH to prepare a time-lapse sample. Moreover, as an adhesive tape, brand name “No. 502” (manufactured by Nitto Denko Corporation; acrylic double-sided adhesive tape, width: 50 mm; adhesive tape A), brand name “No. 5000 NS” (manufactured by Nitto Denko Corporation; acrylic) System double-sided adhesive tape, width: 50 mm; adhesive tape B), trade name “KSR-532P” (manufactured by Nitto Denko Corporation; acrylic double-sided adhesive tape, width: 50 mm; adhesive tape C) is used.

  After peeling off the release paper of the adhesive tape and pasting the heavy-side release layer (multi-side release layers A to G) on one adhesive surface of the adhesive tape, the other exposed adhesive surface Roll of adhesive tape in contact with the light side release layer (light side release layer A) and with the light side release layer positioned on the outside. A body (rolled body) is produced. This adhesive tape roll is stored at room temperature for 1 day and then unwound (peeled) to see if peeling occurs at the interface between the adhesive surface and the light-side release layer (ie, tearing phenomenon) If there is peeling at the interface between the pressure-sensitive adhesive surface and the light-side release layer (that is, if there is no crying separation phenomenon), The case where peeling occurred at the interface with the heavy surface side release treatment layer (that is, the case where a tearing phenomenon occurred) was evaluated as “x”. In addition, the winding number (length) of the roll body of an adhesive tape is 10 m, and roll width is 250 mm.

  As is clear from Table 1, the release liners according to Examples 1 to 3 have a good reduction in peel strength over time of the heavy-side release layer of 50% or less, and in addition, residual adhesive strength ( %) Was also confirmed to be good. Therefore, when the release liner according to Examples 1 to 3 is used as a release liner for a double-sided pressure-sensitive adhesive tape and wound into a roll, the occurrence of the tearing phenomenon can be suppressed or prevented. Moreover, regardless of the type of the double-sided pressure-sensitive adhesive tape, it is possible to suppress or prevent the occurrence of the tearing phenomenon. Therefore, even when a special production apparatus is not provided in the production process for producing the release liner, when the double-sided pressure-sensitive adhesive tape using the release liner is used, the occurrence of an abnormal release is effectively suppressed or Can be prevented.

FIG. 1 is a schematic diagram showing a double-sided pressure-sensitive adhesive tape wound in a roll shape.

Explanation of symbols

1 Double-sided adhesive tape in the form of a roll (double-sided adhesive tape roll)
2 Double-sided adhesive tape 2a Adhesive layer 2b Base material (Base material for double-sided adhesive tape)
2c Adhesive layer 3 Release liner 3a Light side release layer 3b Substrate (release liner substrate)
3c Heavy surface side release treatment layer

Claims (2)

A release liner having a configuration in which release treatment layers are formed on both surfaces of a substrate, wherein the release treatment layer on one surface side of the substrate is formed of a thermosetting silicone release agent, and The release treatment layer on the other surface side is formed of an ultraviolet curable silicone release agent , and the release treatment layer formed of the thermosetting silicone release agent has a release strength on the side having a low peel strength with respect to the adhesive surface. A mold release treatment layer used as a mold treatment layer and formed with an ultraviolet curable silicone release agent is used as a mold release treatment layer on the side having a high peel strength with respect to the adhesive surface, and is formed with an ultraviolet curable silicone release agent. The release treatment layer thus formed has a peel strength (peel angle: 180 °, tensile speed: 300 mm / min, 23 ° C., 50% RH) with respect to the adhesive surface of 0.1 to 1.0 N / 50 mm and a temperature of 60. ℃ In a release treatment layer formed of a thermosetting silicone release agent, the rate of decrease in peel strength when left for 21 days in an environment of 90% RH is 50% or less. A release liner having a peel strength (peeling angle: 180 °, tensile speed: 300 mm / min, 23 ° C, 50% RH) with respect to the adhesive surface of 0.01 to 0.3 N / 50 mm . A double-sided pressure-sensitive adhesive tape or sheet having a structure in which the double-sided adhesive surfaces are protected by a single release liner, wherein the release liner according to claim 1 is used as the release liner. Double-sided adhesive tape or sheet.

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