WO2024024829A1 - 粘着シートの剥離方法 - Google Patents

粘着シートの剥離方法 Download PDF

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Publication number
WO2024024829A1
WO2024024829A1 PCT/JP2023/027352 JP2023027352W WO2024024829A1 WO 2024024829 A1 WO2024024829 A1 WO 2024024829A1 JP 2023027352 W JP2023027352 W JP 2023027352W WO 2024024829 A1 WO2024024829 A1 WO 2024024829A1
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WIPO (PCT)
Prior art keywords
adhesive
adherend
adhesive sheet
peeling
ethanol
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PCT/JP2023/027352
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English (en)
French (fr)
Japanese (ja)
Inventor
健太 熊倉
哲士 本田
廉人 太田
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Nitto Denko Corp
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Nitto Denko Corp
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Priority to JP2024537782A priority Critical patent/JPWO2024024829A1/ja
Priority to KR1020257006185A priority patent/KR20250043487A/ko
Publication of WO2024024829A1 publication Critical patent/WO2024024829A1/ja
Anticipated expiration legal-status Critical
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    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J5/00—Adhesive processes in general; Adhesive processes not provided for elsewhere, e.g. relating to primers
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
    • B65H—HANDLING THIN OR FILAMENTARY MATERIAL, e.g. SHEETS, WEBS, CABLES
    • B65H41/00—Machines for separating superposed webs

Definitions

  • the present invention relates to a method for peeling a pressure-sensitive adhesive sheet. Specifically, the present invention relates to a method for peeling a pressure-sensitive adhesive sheet, which includes applying an adhesive force reducing means.
  • This application claims priority based on Japanese Patent Application No. 2022-122052 filed on July 29, 2022, and the entire contents of that application are incorporated herein by reference.
  • adhesives also referred to as pressure-sensitive adhesives, hereinafter the same
  • adhesives are widely used in various fields in the form of adhesive sheets with a support, which have an adhesive layer on the support, or in the form of support-less adhesive sheets, which do not have a support. It's being used. Further, after use, the adhesive is peeled off from the adherend by appropriate means, if necessary.
  • Technical documents for peeling adhesives from adherends include Patent Documents 1 and 2.
  • display devices built into products with display functions such as smartphones, personal computers (desktops, notebooks, tablets, etc.), televisions, etc.
  • display devices built into products with display functions such as smartphones, personal computers (desktops, notebooks, tablets, etc.), televisions, etc.
  • organic EL (electroluminescence) display devices It has a multilayer structure including a plurality of different functional components, such as a PDP (plasma display panel), and each component contains a different material, so there is a great advantage in reusing it through recycling, reuse, etc.
  • surface protection sheets are adhered to the surfaces to protect them from damage and dirt. Such a surface protection sheet is removed from the adherend at an appropriate timing after the protection purpose is achieved.
  • an adhesive bonded to an adherend such as a member is usually peeled off from the adherend by utilizing the removability of the adhesive itself.
  • pressure-sensitive adhesives that are required to have high bonding reliability generally have high adhesion to adherends, and tend to have poor removability (re-peelability) from adherends.
  • the adherend may include a hard and brittle member such as glass or a thin member, and such an adherend may be damaged by the force applied when the adhesive is peeled off.
  • Patent Document 1 a technology that achieves both adhesion to adherends and removability, which can be easily peeled off using water, and We are proposing an adhesive sheet (water-releasable adhesive sheet) with improved water resistance reliability during bonding.
  • the water-releasable adhesive sheet proposed in Patent Document 1 is based on the premise that an aqueous liquid such as water is used to peel the adhesive sheet from the adherend. While it can be suitably applied to adherends with high peeling, it may not be suitably applied to adherends with low hydrophilicity.
  • a technology has been provided that achieves both adhesion and removability for adherends with relatively low hydrophilicity, such as metals and resins, in addition to highly hydrophilic adherends. This is advantageous because it broadens the range of applicable adherends.
  • the present invention was created in view of the above circumstances, and is a peeling method that can be applied even to adherends with relatively low hydrophilicity, and which improves adhesive strength and removability to the adherend.
  • An object of the present invention is to provide a method for peeling a pressure-sensitive adhesive sheet that achieves both of the following.
  • a method for peeling a pressure-sensitive adhesive sheet stuck to an adherend includes applying an adhesive force reducing means to the adhesive sheet.
  • the adhesive force reducing means includes supplying an alcohol liquid to an interface between the adherend and the adhesive sheet at a peeling front of the adhesive sheet from the adherend, and supplying the alcohol liquid to the interface. is present, the peeling front of the pressure-sensitive adhesive sheet is moved in the peeling advancing direction, and the alcohol liquid is allowed to enter the interface following the movement of the peeling front.
  • the adhesive force reducing means by applying the adhesive force reducing means, the adhesive force of the adhesive sheet can be reduced, so that the peelability (repeelability) from the adherend can be improved.
  • the adhesive strength reducing means disclosed herein uses an alcohol solution, it may be difficult to apply water to an adherend whose surface is made of a material with relatively low hydrophilicity such as metal or resin. Even when applied to adherends to which water removal is difficult, the releasability (re-peelability) from the adherend can be improved.
  • a water removal step such as drying or wiping the adherend is sometimes necessary.
  • an alcohol solution is used instead of water, the process of removing the liquid from the adherend after peeling tends to be shorter or simpler than before. Such a peeling method is also advantageous from the viewpoint of production efficiency.
  • the adhesive sheet is prepared by attaching the adhesive sheet to a stainless steel plate as an adherend and dropping 2 ⁇ L of ethanol onto the adherend one day after the adhesive sheet is attached to the adherend at room temperature. After entering one end of the interface with the adherend, according to JIS Z0237:2009 10.4.1 Method 1: 180° peeling adhesive force to the test plate, specifically, tensile at a test temperature of 23°C.
  • the ethanol peel force N1 SUS measured using a testing machine at a tensile speed of 300 mm/min and a peel angle of 180 degrees, is 0.5 N/20 mm or less.
  • a pressure-sensitive adhesive sheet having an ethanol peel force N1 SUS with respect to a stainless steel plate is equal to or lower than the above upper limit value
  • the adhesive force reduction effect due to alcohol peeling is likely to be suitably exhibited, and re-peelability from the adherend can be improved.
  • adherends having good wettability with ethanol include those having a contact angle with ethanol of 50 degrees or less.
  • the adherend include adherends whose adherend surfaces are made of a material such as glass, metal (eg, stainless steel, aluminum, etc.), resin (eg, PET, polyimide (PI), etc.).
  • the adhesive sheet is applied to a stainless steel plate as an adherend, and after one day at room temperature, the adhesive sheet cut into a rectangular shape with a width of 20 mm is attached to the adherend.
  • the adhesive force reduction distance R SUS is 30 mm or more, which is measured at a test temperature of 23° C. using a tensile tester at a tensile speed of 300 mm/min and a peel angle of 180 degrees.
  • alcohol liquid is supplied to the interface between the adhesive sheet and the adherend (for example, an adherend whose adherend surface is made of metal, resin, etc.).
  • the effects of the adhesive force reducing means, including the above, tend to continue without deterioration.
  • a pressure-sensitive adhesive sheet that maintains the effect of reducing adhesive force is preferable from the viewpoint of reducing the amount of alcohol used in the peeling process and working efficiency.
  • the adhesive sheet has an adhesive force N0 SUS of 3.0 N/20 mm or more after one day at room temperature after attaching the adhesive sheet to a stainless steel plate as an adherend. Since the above-mentioned adhesive sheet has an adhesion force N0 SUS to a stainless steel plate that is above the lower limit value, it has excellent adhesion reliability to adherends (for example, adherends whose adherend surface is made of metal, resin, etc.). There is a tendency to show that
  • Adhesive force reduction rate S SUS [%] (1 - (ethanol peeling force N1 SUS / adhesive force N0 SUS )) x 100; S SUS is 50% or more, and adhesive force reduction distance R SUS is 30 mm or more.
  • the adhesive sheet is attached to an alkali glass plate prepared by a float method as an adherend, and after one day at room temperature, 2 ⁇ L of ethanol is dropped onto the adherend.
  • 2 ⁇ L of ethanol is dropped onto the adherend.
  • Method 1 180° peeling adhesive force to the test plate, specifically, The ethanol peel force N1 GLA is 0.5 N/20 mm or less, which is measured at a test temperature of 23° C. using a tensile tester at a tensile speed of 300 mm/min and a peel angle of 180 degrees.
  • the adhesive sheet is attached to an alkali glass plate prepared by a float method as an adherend, and after one day at room temperature, the adhesive sheet cut into a rectangular shape with a width of 20 mm is attached.
  • JIS Z0237:2009 10.4.1 Method 1 180° pull on the test plate
  • the adhesive force reduction distance R GLA is 30 mm or more, which is measured at a test temperature of 23 ° C. using a tensile tester at a tensile speed of 300 mm/min and a peel angle of 180 degrees. .
  • an adhesive sheet whose adhesion force reduction distance R GLA to a glass plate is 30 mm or more, it is recommended to supply alcohol liquid to the interface between the adhesive sheet and the adherend (for example, an adherend whose adherend surface is made of glass).
  • the effect of the adhesive force reducing means included therein tends to be sustained without deterioration.
  • a pressure-sensitive adhesive sheet that maintains the effect of reducing adhesive force is preferable from the viewpoint of reducing the amount of alcohol used in the peeling process and working efficiency.
  • the adhesive sheet has an adhesive force N0 GLA of 3.0 N/20 mm or more after one day at room temperature after attaching the adhesive sheet to an alkali glass plate prepared by a float method as an adherend. . Since the above-mentioned adhesive sheet has an adhesion force N0 GLA to a glass plate of 3.0 N/20 mm or more, it has excellent adhesion reliability to an adherend (for example, an adherend whose surface is made of glass). There is a tendency to show
  • Adhesive force reduction rate S GLA [%] (1 - (ethanol peeling force N1 GLA / adhesive force N0 GLA )) x 100; S GLA is 50% or more, and adhesive force reduction distance R GLA is 30 mm or more.
  • FIG. 1 is a cross-sectional view schematically showing the configuration of a pressure-sensitive adhesive sheet according to an embodiment.
  • weight may be read as “mass”.
  • % by weight may be read as “% by mass”
  • parts by weight may be read as “parts by mass”.
  • a method for peeling a pressure-sensitive adhesive sheet stuck to an adherend is provided.
  • the above peeling method is characterized in that an adhesive force reducing means is applied to the adhesive sheet.
  • the adhesive force reducing means disclosed herein supplies an alcohol liquid to an interface between the adherend and the adhesive sheet at a peeling front of the adhesive sheet from the adherend, and the alcohol liquid is present at the surface.
  • the peeling front of the pressure-sensitive adhesive sheet is moved in the peeling advancing direction, and the alcohol liquid is allowed to enter the interface in accordance with the movement of the peeling front.
  • alcohol liquid is used instead of conventional water as the liquid supplied to reduce the adhesive force of the adhesive sheet to the adherend, so it is relatively hydrophilic, making it difficult to apply water peeling.
  • the effect of reducing adhesive strength tends to be preferably exhibited even for adherends with low adhesive strength.
  • the process of removing the alcohol solution from the adherend after stripping tends to be shorter or simpler.
  • alcohols or mixed solvents containing alcohols as a main component, containing small amounts of additives as necessary, can be used.
  • a monohydric lower alcohol having 1 to 4 carbon atoms it is preferable to use a monohydric lower alcohol having 1 to 4 carbon atoms as the alcohol, and methanol, ethanol, isopropyl alcohol, etc. are particularly preferable.
  • ethanol is preferred from the viewpoints of safety, versatility, etc.
  • the solvent other than alcohols constituting the above mixed solvent water, lower ketones (eg, acetone), etc. that can be uniformly mixed with alcohols may be used.
  • the additive known surfactants and the like can be used. From the viewpoint of avoiding contamination of the adherend, in some embodiments, an alcoholic liquid containing substantially no additives may be preferably used.
  • the content of alcohol in the alcohol solution is more than 50% by weight, may be 60% by weight or more, and 70% by weight. % or more, 80 weight % or more, 90 weight % or more, 95 weight % or more, or 98 weight % or more.
  • the alcohol peeling involves supplying an alcohol solution near the outer edge of the adhesive sheet attached to the adherend, and applying the alcohol liquid from the outer edge of the adhesive sheet to the adhesive sheet and the adherend. After the adhesive sheet enters the interface, the adhesive sheet is peeled off without supplying new alcohol (that is, using only the alcohol that was supplied to the adherend before the start of peeling). Can be done.
  • the alcohol liquid that follows the movement of the peeling front and enters the interface between the adhesive sheet and the adherend runs out during the alcohol peeling process, the alcohol liquid may be removed intermittently after the start of the alcohol peeling process. Alternatively, additional alcohol liquid may be continuously supplied.
  • the amount of alcohol liquid (for example, ethanol) supplied before the start of peeling is not particularly limited, as long as it can introduce the alcohol liquid to the interface between the adhesive sheet and the adherend from outside the area where the adhesive sheet is attached.
  • the amount of the alcohol solution may be, for example, 5 ⁇ L or more, suitably 10 ⁇ L or more, and may be 20 ⁇ L or more. Further, there is no particular restriction on the upper limit of the amount of the alcohol solution.
  • the amount of the alcoholic liquid may be, for example, 10 mL or less, 5 mL or less, 1 mL or less, 0.5 mL or less, 0.1 mL or less. It may be 0.05 mL or less.
  • the operation of injecting alcohol liquid into the interface between the adhesive sheet and the adherend from the outer edge of the adhesive sheet can be performed, for example, by inserting the tip of a jig such as a cutter knife or needle into the interface at the outer edge of the adhesive sheet. Insert the adhesive sheet, scratch the outer edge of the adhesive sheet with a hook or nail, etc., and lift it up, or attach a strong adhesive tape, suction cup, etc. to the back surface near the outer edge of the adherend and lift the edge of the adhesive sheet. It can be carried out.
  • a jig such as a cutter knife or needle
  • the alcohol peeling step can be preferably carried out in such a manner that the peeling front is moved at a speed of 10 mm/min or more.
  • Moving the peeling front at a speed of 10 mm/min or more corresponds to peeling the adhesive sheet at a tensile speed of 20 mm/min or more, for example, under the condition of a peeling angle of 180 degrees.
  • the speed at which the peeling front is moved may be, for example, 50 mm/min or more, 150 mm/min or more, 300 mm/min or more, or 500 mm/min or more.
  • the upper limit of the speed at which the peeling front is moved is not particularly limited.
  • the speed at which the peeling front is moved may be, for example, 1000 mm/min or less.
  • the alcohol peeling disclosed herein is carried out, for example, in such a manner that the peeled area of the adhesive sheet per 10 ⁇ L volume of the alcohol solution (e.g. ethanol) used in the method is, for example, 50 cm 2 or more, preferably 100 cm 2 or more. be able to.
  • the alcohol solution e.g. ethanol
  • the pressure-sensitive adhesive sheet used in the peeling method disclosed herein is not particularly limited as long as it can exhibit the effect of reducing adhesive force by alcohol peeling, and various types can be used.
  • the adhesive sheet has an ethanol peel force on a stainless steel plate (hereinafter referred to as "ethanol peel force on a stainless steel plate”) measured at a temperature of 23° C., a tensile speed of 300 mm/min, and a peel angle of 180 degrees.
  • force N1 SUS or simply "ethanol peeling force N1 SUS ”
  • adherends examples include adherends whose adherend surfaces are made of a material such as glass, metal (eg, stainless steel, aluminum, etc.), resin (eg, PET, PI, etc.).
  • adherends whose adherend surfaces are made of a material such as glass, metal (eg, stainless steel, aluminum, etc.), resin (eg, PET, PI, etc.).
  • adherends with relatively low hydrophilicity for example, adherends whose adherend surface is made of metal, resin, etc.).
  • the re-peelability from the adherend can be improved.
  • the ethanol peeling force N1 SUS of the pressure-sensitive adhesive sheet to the stainless steel plate is more preferably 0.48 N/20 mm or less, still more preferably 0.45 N/20 mm or less, particularly preferably 0.4 N/20 mm or less.
  • the ethanol peeling force N1 SUS of the pressure-sensitive adhesive sheet to the stainless steel plate may be 0.35 N/20 mm or less, or 0.3 N/20 mm or less.
  • the lower limit of the ethanol peeling force N1 SUS is not particularly limited. In principle, the ethanol peeling force N1 SUS is 0 N/20 mm or more.
  • the ethanol peeling force N1 SUS of the adhesive sheet to the stainless steel plate may be 0.05 N/20 mm or more, and 0.1 N/20 mm or more. But that's fine.
  • the ethanol peel force N1 SUS of the adhesive sheet to the stainless steel plate may be 0.2 N/20 mm or less, 0.1 N/20 mm or less, or 0.05 N/20 mm or less. It may be 0.03 N/20 mm or less.
  • the lower limit of the ethanol peeling force N1 SUS of the pressure-sensitive adhesive sheet to the stainless steel plate is not particularly limited. In principle, the ethanol peeling force N1 SUS is 0 N/20 mm or more.
  • the ethanol peeling force N1 SUS against a stainless steel plate is measured in detail by the following method. A similar measurement method is used in the examples described later.
  • a test piece is prepared by cutting the adhesive sheet to be measured into a rectangular shape with a width of 20 mm and a length of 120 mm.
  • An evaluation sample in which the adhesive side of the test piece was bonded to a stainless steel plate (SUS304BA plate) as an adherend using a hand roller was placed in an autoclave and treated for 15 minutes at a pressure of 5 atm and a temperature of 50°C. After holding the evaluation sample taken out from the autoclave in an environment of 23°C and 50% RH for one day, in the same environment, 2 ⁇ L of ethanol was applied to the surface of the adherend exposed from the end near one longitudinal end of the test piece. drip.
  • JIS Z0237:2009 10.4.1 Method 1 180° peeling adhesive force to the test plate Accordingly, specifically, the peel strength was measured using a tensile tester at a test temperature of 23° C. at a tensile speed of 300 mm/min and a peel angle of 180 degrees, and this was determined as the ethanol peel force against the stainless steel plate N1 SUS [N /20mm].
  • the contact angle of the surface of the stainless steel plate (SUS304BA plate) used as the adherend to which the adhesive sheet is bonded to ethanol is approximately 10 degrees, and the contact angle to distilled water is approximately 85 degrees.
  • the adhesive sheet has adhesive strength (hereinafter referred to as "stainless steel”) to a stainless steel plate measured at a temperature of 23° C., a tensile speed of 300 mm/min, and a peel angle of 180 degrees.
  • the adhesive force to the steel plate (also referred to as “adhesive force N0 SUS “ or simply “adhesive force N0 SUS ”) is 3.0 N/20 mm or more.
  • adherends for example, adherends whose adherend surface is made of metal, resin, etc.
  • the adhesive force N0 SUS of the adhesive sheet to the stainless steel plate is more preferably 3.5 N/20 mm or more, still more preferably 4.0 N/20 mm or more, particularly preferably 4.5 N/20 mm or more.
  • the upper limit of the adhesive force N0 SUS to the stainless steel plate is not particularly limited. From the viewpoint of balancing other adhesive properties, the adhesive force N0 SUS of the adhesive sheet to the stainless steel plate may be 15 N/20 mm or less, 10 N/20 mm or less, or 7 N/20 mm or less.
  • the adhesive force N0 SUS of the adhesive sheet to the stainless steel plate may be less than 3.0 N/20 mm, may be less than 2.5 N/20 mm, or may be less than 2.0 N/20 mm. , 1.0N/20mm or less.
  • the lower limit of the adhesive force N0 SUS of the adhesive sheet to the stainless steel plate is not particularly limited. In principle, the adhesive force N0 SUS is 0 N/20 mm or more, for example, it may be 0.1 N/20 mm or more, or it may be 0.2 N/20 mm or more.
  • the adhesive force N0 SUS to a stainless steel plate is measured by the following method. A similar measuring method is used in the examples described later.
  • a test piece is prepared by cutting the adhesive sheet to be measured into a rectangular shape with a width of 20 mm and a length of 120 mm.
  • An evaluation sample in which the adhesive side of the test piece was bonded to a stainless steel plate (SUS304BA plate) as an adherend using a hand roller was placed in an autoclave and treated at a pressure of 5 atm and a temperature of 50° C. for 15 minutes.
  • a cutter knife was inserted into the interface between the test piece and the adherend under the same environment to cut the longitudinal direction of the test piece.
  • the adhesive sheet has a rectangular adhesive sheet with a width of 20 mm, and is measured at a temperature of 23° C., at a tensile rate of 300 mm/min, and at a peel angle of 180 degrees, with respect to a stainless steel plate.
  • the adhesive force reduction distance (hereinafter also referred to as "adhesive force reduction distance R SUS to stainless steel plate” or simply “adhesive force reduction distance R SUS ”) is 30 mm or more.
  • an adhesive sheet whose adhesion force reduction distance R SUS to a stainless steel plate is 30 mm or more, alcohol liquid is supplied to the interface between the adhesive sheet and the adherend (for example, an adherend whose adherend surface is made of metal, resin, etc.).
  • the effects of the adhesive force reducing means tend to continue without deterioration.
  • a pressure-sensitive adhesive sheet that maintains the effect of reducing adhesive force is preferable from the viewpoint of reducing the amount of alcohol used in the peeling process and working efficiency.
  • the adhesive force reduction distance R SUS to a stainless steel plate is measured by the following method. A similar measuring method is used in the examples described later.
  • a test piece is prepared by cutting the adhesive sheet to be measured into a rectangular shape with a width of 20 mm and a length of 120 mm.
  • An evaluation sample in which the adhesive side of the test piece was bonded to a stainless steel plate (SUS304BA plate) as an adherend using a hand roller was placed in an autoclave and treated for 15 minutes at a pressure of 5 atm and a temperature of 50°C. After holding the evaluation sample taken out from the autoclave in an environment of 23°C and 50% RH for one day, in the same environment, 2 ⁇ L of ethanol was applied to the surface of the adherend exposed from the end near one longitudinal end of the test piece. drip.
  • JIS Z0237:2009 10.4.1 Method 1 180° peeling adhesive force to the test plate Accordingly, specifically, the peel strength is continuously measured at a test temperature of 23° C. using a tensile tester at a tensile speed of 300 mm/min and a peel angle of 180 degrees. At this time, the peel strength that is continuously measured starting from the point where ethanol is dropped on the interface is 0.5 ⁇ (adhesive force N0 SUS - ethanol peel force N1) than the ethanol peel force N1 SUS [N/20 mm]. Measure the moving distance of the peeling front of the adhesive sheet from the start point to the end point when the end point is the point where the area has increased by more than SUS ) [N/20 mm], and define this as the adhesive force reduction distance R SUS [mm].
  • an adherend for example, an adherend whose adherend surface is made of metal or resin
  • the adhesive strength reduction rate S SUS is suitably 70% or more, preferably 80% or more, more preferably more than 90%, and still more preferably 92% or more, For example, it may be 95% or more, or 97% or more.
  • the upper limit of the adhesive force reduction rate S SUS is 100% in principle, and is, for example, less than 100%.
  • the pressure-sensitive adhesive sheet has an ethanol peel force against a glass plate (hereinafter referred to as "ethanol peel force against a glass plate”) measured at a temperature of 23° C., a tensile speed of 300 mm/min, and a peel angle of 180 degrees. It is preferable that the pressure-sensitive adhesive sheet has a force N1 GLA or simply "ethanol peeling force N1 GLA " of 0.5 N/20 mm or less. If an adhesive sheet with an ethanol peeling force N1 GLA of 0.5 N/20 mm or less for the glass plate is used, re-peelability from the adherend can be improved even when the adherend surface is made of glass, for example. can be improved.
  • the ethanol peel force N1 GLA of the adhesive sheet to the glass plate is more preferably 0.45 N/20 mm or less (for example, 0.4 N/20 mm or less), and even more preferably 0.3 N/20 mm or less (for example, 0.25 N/20 mm or less). 20 mm or less), particularly preferably 0.2 N/20 mm or less.
  • the ethanol peel force N1 GLA of the adhesive sheet to the glass plate may be 0.15 N/20 mm or less, or 0.1 N/20 mm or less.
  • the lower limit of the ethanol peeling force N1 GLA is not particularly limited. In principle, the ethanol peeling force N1 GLA is 0 N/20 mm or more. From the viewpoint of balancing adhesive properties when bonding to an adherend, the ethanol peeling force N1 GLA of the adhesive sheet to the glass plate may be 0.05 N/20 mm or more, and 0.1 N/20 mm or more. But that's fine.
  • the ethanol peel force N1 GLA of the adhesive sheet to the glass plate may be 0.2 N/20 mm or less, 0.1 N/20 mm or less, or 0.05 N/20 mm or less. It may be 0.03 N/20 mm or less.
  • the lower limit of the ethanol peeling force N1 GLA of the pressure-sensitive adhesive sheet to the glass plate is not particularly limited. In principle, the ethanol peeling force N1 GLA is 0 N/20 mm or more.
  • the ethanol peeling force N1 GLA with respect to the glass plate is specifically measured by the following method. A similar measuring method is used in the examples described later.
  • a test piece is prepared by cutting the adhesive sheet to be measured into a rectangular shape with a width of 20 mm and a length of 120 mm.
  • An evaluation sample was prepared by pasting the adhesive side of the above test piece onto an alkali glass plate (manufactured by Matsunami Glass Industries Co., Ltd., manufactured by the float method, thickness 1.35 mm, blue plate edge polished) using a hand roller. The sample was placed in an autoclave and treated for 15 minutes at a pressure of 5 atm and a temperature of 50°C.
  • the contact angle of the surface of the alkali glass plate used as the adherend to which the adhesive sheet is bonded to ethanol is about 10 degrees, and the contact angle to distilled water is 8 degrees.
  • the adherends used for measuring the adhesive force N0 GLA to the glass plate and the adhesive force reduction distance R GLA to the glass plate below is the same applies.
  • the adhesive sheet has adhesive strength (hereinafter referred to as "glass adhesive strength”) to a glass plate measured at a temperature of 23° C., a tensile speed of 300 mm/min, and a peeling angle of 180 degrees.
  • the adhesive force to the plate also referred to as “adhesive force N0 GLA “ or simply “adhesive force N0 GLA ”
  • N0 GLA adhesive force to the plate
  • it has excellent adhesion reliability to the adherend before peeling (for example, an adherend whose adherend surface is made of glass). It tends to show gender.
  • the adhesive force N0 GLA of the adhesive sheet to the glass plate is more preferably 3.5 N/20 mm or more, still more preferably 4.0 N/20 mm or more, particularly preferably 4.5 N/20 mm or more.
  • the upper limit of the adhesive force N0 GLA to the glass plate is not particularly limited. From the viewpoint of balancing other adhesive properties, the adhesive force N0 GLA of the adhesive sheet to the glass plate may be 20 N/20 mm or less, 15 N/20 mm or less, 10 N/20 mm or less, 8 It may be .5N/20mm or less.
  • the adhesive force N0 GLA of the adhesive sheet to the glass plate may be less than 3.0 N/20 mm, may be less than 2.5 N/20 mm, or may be less than 2.0 N/20 mm. , 1.0N/20mm or less.
  • the lower limit value of the adhesive force N0 GLA of the adhesive sheet to the glass plate is not particularly limited. In principle, the adhesive force N0 GLA is 0 N/20 mm or more, for example, it may be 0.1 N/20 mm or more, or it may be 0.2 N/20 mm or more.
  • the adhesive force N0 GLA to the glass plate is measured by the following method. A similar measurement method is used in the examples described later.
  • a test piece is prepared by cutting the adhesive sheet to be measured into a rectangular shape with a width of 20 mm and a length of 120 mm.
  • An evaluation sample was prepared by pasting the adhesive side of the above test piece onto an alkali glass plate (manufactured by Matsunami Glass Industries Co., Ltd., manufactured by the float method, thickness 1.35 mm, blue plate edge polished) using a hand roller. The sample was placed in an autoclave and treated for 15 minutes at a pressure of 5 atm and a temperature of 50°C.
  • the adhesive sheet has a rectangular adhesive sheet with a width of 20 mm, and is measured at a temperature of 23° C., at a tensile rate of 300 mm/min, and at a peeling angle of 180 degrees with respect to a glass plate.
  • the adhesive force reduction distance (hereinafter also referred to as "adhesive force reduction distance RGLA “ or simply “adhesive force reduction distance RGLA ”) is 30 mm or more.
  • R GLA adhesion force reduction distance
  • R GLA adhesion force reduction distance
  • the effect of the adhesive force reducing means included therein tends to be sustained without deterioration.
  • a pressure-sensitive adhesive sheet that maintains the effect of reducing adhesive force is preferable from the viewpoint of reducing the amount of alcohol used in the peeling process and working efficiency.
  • the adhesive force reduction distance R GLA to the glass plate is specifically measured by the following method. A similar measuring method is used in the examples described later.
  • a test piece is prepared by cutting the adhesive sheet to be measured into a rectangular shape with a width of 20 mm and a length of 120 mm.
  • An evaluation sample was prepared by pasting the adhesive side of the above test piece onto an alkali glass plate (manufactured by Matsunami Glass Industries Co., Ltd., manufactured by the float method, thickness 1.35 mm, blue plate edge polished) using a hand roller. The sample was placed in an autoclave and treated for 15 minutes at a pressure of 5 atm and a temperature of 50°C.
  • the peel strength continuously measured starting from the point where ethanol was dropped on the above interface was 0.5 ⁇ (adhesive force N0 GLA - ethanol peel force N1) than the ethanol peel force N1 GLA [N/20 mm].
  • GLA ) [N/20 mm] or more is the end point, and the moving distance of the peeling front of the adhesive sheet from the start point to the end point is measured, and this is defined as the adhesive force reduction distance R GLA [mm].
  • Adhesive force reduction rate S GLA (Adhesive force reduction rate S GLA )
  • Adhesive sheets with a high adhesive strength reduction rate S GLA have sufficient adhesive strength when attached to an adherend (for example, an adherend whose surface is made of glass), but when peeled off and removed, adhesive sheets such as ethanol etc. By peeling using an alcohol solution, the load applied to the adherend during peeling can be significantly reduced.
  • the adhesive force reduction rate S GLA is suitably more than 70%, preferably 90% or more, for example, it may be 92% or more, it may be 95% or more, it may be 97% or more. But that's fine.
  • the upper limit of the adhesive force reduction rate S GLA is 100% in principle, and is, for example, less than 100%.
  • FIG. 1 shows an example of the configuration of the adhesive sheet disclosed herein.
  • This adhesive sheet 1 is a one-sided adhesive including an adhesive layer 10 whose one surface 10A is a surface to be attached to an adherend, and a support 20 laminated on the other surface 10B of the adhesive layer 10. It is constructed as a sticky adhesive sheet.
  • the adhesive layer 10 is fixedly bonded to one surface 20A of the support 20.
  • a plastic film such as a polyester film can be used.
  • the adhesive layer 10 has a single-layer structure. That is, the entire adhesive layer 10 is constituted by the A layer that constitutes one surface (adhesive surface) 10A of the adhesive layer 10.
  • the adhesive sheet 1 before use (before being attached to an adherend) is, for example, as shown in FIG. It may be in the form of an adhesive sheet 50 with a release liner, which is protected by a release liner.
  • the second surface 20B (the surface opposite to the first surface 20A, also referred to as the back surface) of the support 20 is a release surface, and the adhesive surface 10A is in contact with the second surface 10B.
  • the adhesive surface 10A may be protected by being wound or laminated.
  • the release liner is not particularly limited, and includes, for example, a release liner in which the surface of a liner base material such as a resin film or paper has been subjected to release treatment, a fluorine-based polymer (such as polytetrafluoroethylene), or a polyolefin-based resin (such as polyethylene, polypropylene, etc.). ) can be used, such as a release liner made of a low adhesive material.
  • a silicone-based, long-chain alkyl-based, or other release agent may be used for the above-mentioned peeling treatment.
  • a release-treated resin film may be preferably employed as the release liner.
  • the adhesive sheet in the technology disclosed herein has good reworkability because it can be easily peeled off from the adherend using an alcohol solution, and has excellent adhesion reliability with the adherend during bonding.
  • fixing, bonding, molding, decoration, protection, etc. of the members in the form of attaching them to the adherends for example, members constituting various mobile devices, automobiles, home appliances, etc. It can be used for purposes such as support.
  • the material constituting at least the surface of the above member includes, for example, glass such as an alkali glass plate or non-alkali glass; metal materials such as resin film, stainless steel (SUS), and aluminum; acrylic resin, ABS resin, polycarbonate resin, and polystyrene resin. resin materials such as; etc.
  • the adhesive sheet disclosed herein has a surface coated with a paint such as acrylic, polyester, alkyd, melamine, urethane, acid-epoxy crosslinked, or a composite of these (e.g., acrylic-melamine, alkyd-melamine). Alternatively, it may be attached to a plated surface such as a galvanized steel plate.
  • the adhesive sheet disclosed herein may be, for example, a component of a member with an adhesive sheet, in which such a member (adherent) is joined to the adhesive sheet.
  • the member with the adhesive sheet will also be referred to as a "joint body".
  • the adhesive sheet peeling method disclosed herein can also be understood as a method for separating a member (joined body) with an adhesive sheet as described above.
  • the surface of the member that comes into contact with the adhesive layer (that is, the surface of the adherend to which the adhesive sheet is attached, hereinafter also referred to as the "joining surface") is
  • the surface may have an affinity for ethanol such that the contact angle with respect to ethanol is, for example, 60 degrees or less, preferably 50 degrees or less.
  • the ethanol contact angle of the bonded surface is preferably 40 degrees or less, more preferably 30 degrees or less (for example, 25 degrees or less), still more preferably 20 degrees or less, and 15 degrees or less. The following may be used.
  • the ethanol contact angle of the bonding surface becomes smaller, the alcohol liquid tends to wet and spread along the bonding surface, and the alcohol removability of the pressure-sensitive adhesive sheet tends to improve. This is preferable from the viewpoint of improving re-peelability when producing a member with a pressure-sensitive adhesive sheet by bonding the pressure-sensitive adhesive sheet to the bonding surface.
  • the contact angle of the bonding surface is at least one of the angles mentioned above at the time when the adhesive sheets are bonded together (for example, 30 minutes before bonding), then the contact angle is less than the predetermined value. The effect of improving releasability can be exhibited.
  • the lower limit of the contact angle with respect to ethanol is 0 degrees in principle. In some embodiments, the ethanol contact angle of the bonded surface may be greater than 0 degrees, greater than or equal to 1 degree, greater than or equal to 3 degrees, or greater than or equal to 5 degrees.
  • the surface (bonding surface) of the member that comes into contact with the adhesive layer may be a surface that exhibits such low hydrophilicity that the contact angle with respect to distilled water is, for example, 30 degrees or more, preferably 35 degrees or more.
  • the contact angle of the bonded surface with distilled water may be 40 degrees or more, 45 degrees or more, 50 degrees or more, or 60 degrees or more (for example, more than 60 degrees).
  • the technology disclosed herein tends to be able to achieve both adhesion to adherends and removability even on surfaces with relatively low hydrophilicity. This is significant in that it can be preferably applied to adherends to which conventional water peeling techniques are difficult to apply.
  • the bonded surface may have such hydrophilicity that the contact angle with respect to distilled water is, for example, 60 degrees or less, preferably 50 degrees or less. In some embodiments, the contact angle of the bonded surface to distilled water may be, for example, 45 degrees or less, 40 degrees or less, 35 degrees or less, or 30 degrees or less.
  • the contact angle of the bonding surface becomes smaller, the alcohol liquid tends to wet and spread along the bonding surface, and the alcohol removability of the pressure-sensitive adhesive sheet tends to improve. This is preferable from the viewpoint of improving reworkability when producing a member with a pressure-sensitive adhesive sheet by bonding the pressure-sensitive adhesive sheet to the bonding surface.
  • the contact angle of the bonded surface with distilled water is within any of the above-mentioned angle ranges at least at the time when the adhesive sheets are bonded together (for example, 30 minutes before bonding), then the contact angle is within the predetermined range.
  • the effect of improving reworkability can be exhibited by this.
  • the lower limit of the contact angle is 0 degrees in principle.
  • the contact angle of the bonded surface with distilled water may be greater than 0 degrees, may be greater than 1 degree, may be greater than 3 degrees, or may be greater than 5 degrees.
  • the contact angle of the bonded surface with respect to ethanol and with respect to distilled water is measured as follows. That is, in a measurement atmosphere of 23°C and 50% RH, a contact angle meter (manufactured by Kyowa Interface Science Co., Ltd., trade name "DMo-501 type", a control box “DMC-2", and a control/analysis software "FAMAS") was used. Measurements are performed by the droplet method using version 5.0.30). The amount of ethanol dropped when measuring the contact angle for ethanol and the amount of distilled water dropped when measuring the contact angle for distilled water are each 2 ⁇ L, and the contact angle is calculated using the ⁇ /2 method from the image 5 seconds after dropping. (Implemented on N5).
  • An example of a preferred use is optical use. More specifically, for example, as a method for peeling an optical pressure-sensitive adhesive sheet used for bonding optical members (for bonding optical members) or for manufacturing products (optical products) in which the above-mentioned optical members are used, The peeling method disclosed herein can be preferably implemented.
  • the above-mentioned optical member refers to a member having optical properties (for example, polarization, light refraction, light scattering, light reflection, light transmission, light absorption, light diffraction, optical rotation, visibility, etc.). say.
  • the above-mentioned optical member is not particularly limited as long as it has optical properties, but for example, it may be a member constituting a device (optical device) such as a display device (image display device) or an input device, or a member used in these devices.
  • Members include, for example, polarizing plates, wavelength plates, retardation plates, optical compensation films, brightness enhancement films, light guide plates, reflective films, antireflection films, hard coat (HC) films, shock absorption films, antifouling films, Photochromic films, light control films, transparent conductive films (ITO films), design films, decorative films, surface protection plates, prisms, lenses, color filters, transparent substrates, and members on which these are laminated (collectively referred to as (sometimes referred to as "functional film”).
  • plate and “film” each include forms such as plate, film, and sheet.
  • polarizing film includes “polarizing plate”, “polarizing sheet”, etc. .
  • the above-mentioned display devices include liquid crystal display devices, organic EL display devices, PDPs, electronic paper, etc.
  • the disclosed technology is preferably applied.
  • the display device includes a display device that allows input, such as a touch panel. There is a strong demand for recycling, reuse, etc. of the display device, and it is particularly meaningful to apply the technology disclosed herein.
  • optical member is not particularly limited, but includes, for example, a member (for example, a sheet-like, film-like, or plate-like member) made of glass, acrylic resin, polycarbonate, polyethylene terephthalate, metal thin film, etc.
  • a member for example, a sheet-like, film-like, or plate-like member
  • acrylic resin for example, acrylic resin, polycarbonate, polyethylene terephthalate, metal thin film, etc.
  • optical member in this specification also includes members (design films, decorative films, surface protection films, etc.) that serve to decorate and protect while maintaining the visibility of display devices and input devices.
  • the bonded body disclosed herein and the products, devices, and structures that include the bonded body require high adhesion reliability using adhesive sheets when joining members, while repairing and repairing component parts. It can be a component of an electronic device (preferably a portable electronic device) that requires smooth removal during replacement, inspection, recycling, etc.
  • an electronic device preferably a portable electronic device
  • mobile phones, smartphones, tablet computers, notebook computers, various wearable devices e.g., wristwear type that is worn on the wrist like a wristwatch, modular type that is worn on a part of the body with a clip or strap, etc.
  • glasses type e.g., glasses types including monocular and binocular types, including head-mounted types, clothing types that are attached to shirts, socks, hats, etc.
  • the display device may be a component of an electronic device such as a desktop personal computer, a display, or a television (liquid crystal, plasma, organic EL, etc.).
  • "portable” does not mean that it is simply portable; it also means that it has a level of portability that allows an individual (standard adult) to carry it relatively easily. shall mean.
  • the peeling method disclosed herein can damage or damage the surfaces of glass, metals, organic materials (e.g., PET, PI, etc.) during processing, transportation, storage, etc. It can be preferably applied to a method for peeling off a surface protection sheet that is used by adhering to the surface for the purpose of preventing staining.
  • the above-mentioned surface protection sheet requires a certain degree of adhesion reliability in order to protect the surface of the adherend, but it also needs to be removed at an appropriate time after the protective purpose is achieved. It is desired that it can be easily peeled off and removed from the body.
  • adherends including adherends with low hydrophilicity to which conventional water peeling techniques are difficult to apply, and exhibits an excellent peeling force reduction effect. It is useful as a peeling method.
  • the shape of the adhesive in the adhesive sheet disclosed herein is not particularly limited, and may be a regular or random pattern such as dots or stripes, but typically it is continuously formed. It is in the form of a layered adhesive layer.
  • the adhesive sheet disclosed herein is, for example, configured as a support-less double-sided adhesive sheet consisting of an adhesive layer, or a single-sided adhesive in which an adhesive layer is arranged on one side of a support (substrate). It may be configured as a sheet (single-sided adhesive sheet), or it may be configured as a double-sided adhesive sheet (double-sided adhesive sheet) having an intermediate layer such as a base layer.
  • the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet is not limited to a single-layer structure, and may further include one or more pressure-sensitive adhesive layers having the same or different compositions.
  • the intermediate layer may be a pressure-sensitive adhesive layer, and in that case, the pressure-sensitive adhesive sheet includes first and second pressure-sensitive adhesive layers that constitute the surface of the pressure-sensitive adhesive sheet, and It may have at least three adhesive layers, including an adhesive layer as a layer.
  • the adhesive constituting the adhesive layer examples include acrylic adhesives, rubber adhesives (natural rubber, synthetic rubber, mixtures thereof, etc.), silicone adhesives, polyester adhesives, and urethane adhesives.
  • the adhesive may include one or more types of adhesives selected from various known adhesives, such as adhesives, polyether adhesives, polyamide adhesives, and fluorine adhesives.
  • the acrylic adhesive refers to an adhesive whose main component (base polymer) is an acrylic polymer. The same meaning applies to rubber adhesives and other adhesives.
  • the “base polymer” of the adhesive refers to the main component of the rubbery polymer contained in the adhesive, and is not interpreted in any limited manner other than this.
  • the above-mentioned rubbery polymer refers to a polymer that exhibits rubber elasticity in a temperature range around room temperature.
  • the term "main component” refers to the component contained in the largest proportion among the contained components on a weight basis. Therefore, for example, when the adhesive is composed of three or more components, the content of the main components in the adhesive may be 34% by weight or more.
  • the term "acrylic polymer” refers to a polymer derived from a monomer component containing more than 50% by weight of an acrylic monomer, and is also referred to as an acrylic polymer.
  • the above-mentioned acrylic monomer refers to a monomer derived from a monomer having at least one (meth)acryloyl group in one molecule.
  • (meth)acryloyl refers comprehensively to acryloyl and methacryloyl.
  • (meth)acrylate” comprehensively refers to acrylate and methacrylate
  • “(meth)acrylic” comprehensively refers to acrylic and methacrylic.
  • an acrylic adhesive may be preferably employed as a constituent material of the adhesive.
  • the adhesive disclosed herein may be an acrylic adhesive containing an acrylic polymer.
  • Acrylic adhesives tend to be superior in transparency, weather resistance, and design freedom.
  • Acrylic pressure-sensitive adhesives with high transparency are preferably used for optical applications and, ultimately, for bonding applications for display devices.
  • the adhesive disclosed herein includes, for example, a (meth)acrylic acid alkyl ester having a linear or branched alkyl group having 1 to 20 carbon atoms at the ester end in a proportion of 33% by weight or more.
  • the base polymer contains an acrylic polymer composed of monomer components.
  • a (meth)acrylic acid alkyl ester having an alkyl group having at least X and Y or less carbon atoms at the ester end may be referred to as "(meth)acrylic acid C XY alkyl ester.” Since it is easy to balance the properties, the proportion of (meth)acrylic acid C 1-20 alkyl ester in the total monomer components of the acrylic polymer according to some embodiments is, for example, 35% by weight or more, and 50% by weight. % or more is suitable, and may be 55% or more by weight.
  • the proportion of (meth)acrylic acid C 1-20 alkyl ester among the monomer components may be, for example, 99.9% by weight or less, 99% by weight or less, or 95% by weight or less.
  • the proportion of (meth)acrylic acid C 1-20 alkyl ester in the entire monomer component of the acrylic polymer according to some embodiments may be, for example, 85% by weight or less from the viewpoint of cohesive properties of the adhesive. , 75% by weight or less, or 65% by weight or less.
  • the (meth)acrylic acid C 1-20 alkyl esters can be used alone or in combination of two or more.
  • the monomer component includes at least one of n-butyl acrylate (BA) and 2-ethylhexyl acrylate (2EHA).
  • BA n-butyl acrylate
  • EHA 2-ethylhexyl acrylate
  • the (meth)acrylic acid C 10-14 alkyl ester include lauryl acrylate (LA).
  • (meth)acrylic acid C 10-14 alkyl ester one type can be used alone or two or more types can be used in combination. Furthermore, (meth)acrylic acid C 4-18 alkyl esters can be used alone or in combination of two or more.
  • the proportion of (meth)acrylic acid C 10-14 alkyl ester in the entire monomer component of the acrylic polymer is 3% by weight or more (for example, 5% by weight). or more), more preferably 10% by weight or more (for example, 20% by weight or more), still more preferably 25% by weight or more, 30% by weight or more, 40% by weight or more, 45% by weight or more. It may be at least 50% by weight, or at least 50% by weight.
  • the proportion of (meth)acrylic acid C 10-14 alkyl ester in the entire monomer component of the acrylic polymer may be 95% by weight or less, or may be 90% by weight or less. , 80% by weight or less, 75% by weight or less, 70% by weight or less, or 65% by weight or less.
  • the monomer components constituting the acrylic polymer may include a combination of (meth)acrylic acid C 4-9 alkyl ester and (meth)acrylic acid C 10-14 alkyl ester.
  • the ratio of (meth)acrylic acid C 10-14 alkyl ester to (meth)acrylic acid C 4-9 alkyl ester in the entire monomer component of the acrylic polymer is The weight-based content ratio is preferably 0.1 or more, more preferably 0.3 or more.
  • the weight-based content ratio of (meth)acrylic acid C 10-14 alkyl ester to (meth)acrylic acid C 4-9 alkyl ester in the entire monomer component of the acrylic polymer is 0. It may be 5 or more, 0.8 or more, 1.0 or more, 1.2 or more, 1.4 or more, 1.8 or more, or 2.0 or more. From the viewpoint of balancing adhesive performance, in some embodiments, the weight of (meth)acrylic acid C 10-14 alkyl ester relative to (meth)acrylic acid C 4-9 alkyl ester in the entire monomer component of the acrylic polymer
  • the standard content ratio is preferably 10 or less, more preferably 5.0 or less, may be 4.0 or less, or may be 3.0 or less.
  • the monomer components constituting the acrylic polymer include (meth)acrylic acid alkyl ester and, if necessary, other monomers (copolymerizable monomers) that can be copolymerized with (meth)acrylic acid alkyl ester. You can stay there.
  • the copolymerizable monomer monomers having polar groups (e.g., carboxyl group, hydroxyl group, nitrogen atom-containing ring, etc.) and monomers with a relatively high homopolymer glass transition temperature (e.g., 10° C. or higher) are preferably used. can do.
  • a monomer having a polar group can be useful for introducing crosslinking points into the acrylic polymer and increasing the cohesive force of the adhesive.
  • the copolymerizable monomers can be used alone or in combination of two or more.
  • Non-limiting examples of copolymerizable monomers include carboxy group-containing monomers, acid anhydride group-containing monomers, hydroxyl group-containing monomers, monomers containing sulfonic acid groups or phosphoric acid groups, epoxy group-containing monomers, and cyano group-containing monomers.
  • isocyanate group-containing monomer isocyanate group-containing monomer, amide group-containing monomer, amino group-containing monomer, monomer having a nitrogen atom-containing ring, monomer having a succinimide skeleton, maleimides, aminoalkyl (meth)acrylates, alkoxy group-containing monomer, alkoxysilyl group Containing monomers, vinyl esters, vinyl ethers, aromatic vinyl compounds, olefins, (meth)acrylic esters having an alicyclic hydrocarbon group, (meth)acrylic esters having an aromatic hydrocarbon group, others, ( Heterocycle-containing (meth)acrylates such as tetrahydrofurfuryl meth)acrylate, halogen atom-containing (meth)acrylates such as vinyl chloride and fluorine atom-containing (meth)acrylates, and silicon-containing (meth)acrylates such as silicone (meth)acrylates.
  • Examples include acrylates and (meth)acrylic acid esters obtained from terpene compound derivative alcohols.
  • carboxy group-containing monomers, hydroxyl group-containing monomers, monomers having a nitrogen atom-containing ring, and (meth)acrylic acid esters having an alicyclic hydrocarbon group are preferred.
  • carboxyl group-containing monomers examples include acrylic acid, methacrylic acid, carboxyethyl acrylate, carboxypentyl acrylate, itaconic acid, maleic acid, fumaric acid, crotonic acid, isocrotonic acid, and the like.
  • hydroxyl group-containing monomers examples include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, and ) 4-hydroxybutyl acrylate, 6-hydroxyhexyl (meth)acrylate, 8-hydroxyoctyl (meth)acrylate, 10-hydroxydecyl (meth)acrylate, 12-hydroxylauryl (meth)acrylate, (4)
  • Examples include hydroxyalkyl (meth)acrylates such as -hydroxymethylcyclohexyl)methyl (meth)acrylate.
  • Examples of the monomer having a nitrogen atom-containing ring include N-vinyl-2-pyrrolidone, N-methylvinylpyrrolidone, N-vinylpyridine, N-vinylpiperidone, N-vinylpyrimidine, N-vinylpiperazine, N-vinylpyrazine, N-vinylpyrrole, N-vinylimidazole, N-vinyloxazole, N-(meth)acryloyl-2-pyrrolidone, N-(meth)acryloylpiperidine, N-(meth)acryloylpyrrolidine, N-vinylmorpholine, N-vinyl -3-morpholinone, N-vinyl-2-caprolactam, N-vinyl-1,3-oxazin-2-one, N-vinyl-3,5-morpholinedione, N-vinylpyrazole, N-vinylisoxazole, N -vinylthiazole
  • (meth)acrylic esters having an alicyclic hydrocarbon group include cyclopentyl (meth)acrylate, cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, dicyclopentanyl (meth)acrylate, and adamantyl (meth)acrylate.
  • (meth)acrylic esters having an alicyclic hydrocarbon group include cyclopentyl (meth)acrylate, cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, dicyclopentanyl (meth)acrylate, and adamantyl (meth)acrylate.
  • the amount used is not particularly limited, and is preferably 0.01% by weight or more based on the total monomer components.
  • the amount of the copolymerizable monomer used may be 0.1% by weight or more, or 0.5% by weight or more based on the total monomer components.
  • the amount of the copolymerizable monomer used is 60% by weight or less of the entire monomer component, and it may be 50% by weight or less, and 40% by weight or less. It may be less than %.
  • the monomer component constituting the acrylic polymer may include a hydroxyl group-containing monomer.
  • the hydroxyl group-containing monomer By using the hydroxyl group-containing monomer, the cohesive force and degree of crosslinking (for example, crosslinking using an isocyanate crosslinking agent) of the adhesive can be suitably adjusted.
  • the hydroxyl group-containing monomer those exemplified above can be used, and for example, 2-hydroxyethyl acrylate (HEA) and 4-hydroxybutyl acrylate (4HBA) can be preferably employed.
  • the hydroxyl group-containing monomers can be used alone or in combination of two or more.
  • the amount used is not particularly limited, and in some preferred embodiments, the amount of the hydroxyl group-containing monomer used is 15% by weight or more, preferably 20% by weight or more of the entire monomer component. , preferably 25% by weight or more. Further, from the viewpoint of suppressing water absorption of the adhesive, in some embodiments, it is appropriate that the amount of the hydroxyl group-containing monomer used is, for example, 50% by weight or less (for example, 45% by weight or less) of the entire monomer component. , 40% by weight or less, 30% by weight or less, or 20% by weight or less.
  • the monomer component constituting the acrylic polymer may include an alicyclic hydrocarbon group-containing (meth)acrylate.
  • an alicyclic hydrocarbon group-containing (meth)acrylate thereby, the cohesive force of the adhesive can be increased.
  • the alicyclic hydrocarbon group-containing (meth)acrylate those exemplified above can be used, and for example, cyclohexyl acrylate (CHA) and isobornyl acrylate can be preferably employed.
  • the alicyclic hydrocarbon group-containing (meth)acrylates can be used singly or in combination of two or more.
  • the amount used is not particularly limited, and can be, for example, 1% by weight or more, or 5% by weight or more of the entire monomer component, and even 10% by weight or more. good.
  • the upper limit of the amount of the alicyclic hydrocarbon group-containing (meth)acrylate used is suitably about 40% by weight or less, and may be 25% by weight or less (for example, 15% by weight or less).
  • the monomer component constituting the acrylic polymer may include a monomer having a nitrogen atom.
  • the cohesive force of the adhesive can be increased.
  • the monomer having a nitrogen atom those exemplified above can be used.
  • Preferred examples of the monomer having a nitrogen atom include monomers having a nitrogen atom-containing ring.
  • N-vinyl cyclic amides can be mentioned, and among them, N-vinyl-2-pyrrolidone can be preferably employed.
  • Monomers having a nitrogen atom can be used alone or in combination of two or more.
  • the amount of the monomer having a nitrogen atom is not particularly limited, and may be, for example, 1% by weight or more, or 5% by weight or more of the entire monomer component, Furthermore, it can be 10% by weight or more. Further, the amount of the monomer having a nitrogen atom to be used is preferably, for example, 40% by weight or less of the entire monomer component, may be 30% by weight or less, or may be 15% by weight or less.
  • the monomer components constituting the acrylic polymer include a combination of a (meth)acrylic acid C 10-14 alkyl ester and a monomer having a nitrogen atom (preferably a monomer having a nitrogen atom-containing ring). obtain.
  • the content of (meth)acrylic acid C 10-14 alkyl ester based on the weight of the monomer having a nitrogen atom (preferably the monomer having a nitrogen atom-containing ring) in the entire monomer component of the acrylic polymer.
  • the ratio is preferably 1 or more (for example, 3 or more), may be 5 or more, or may be 10 or more.
  • the weight-based ratio of (meth)acrylic acid C 10-14 alkyl ester to the monomer having a nitrogen atom (preferably the monomer having a nitrogen atom-containing ring) in the entire monomer component of the acrylic polymer is The content ratio is preferably 10,000 or less, may be 5,000 or less, may be 3,000 or less, or may be 2,000 or less. In some embodiments, the content of (meth)acrylic acid C 10-14 alkyl ester based on the weight of the monomer having a nitrogen atom (preferably the monomer having a nitrogen atom-containing ring) in the entire monomer component of the acrylic polymer. The ratio may be 1000 or less, 500 or less, 200 or less, 80 or less, 40 or less, or 20 or less.
  • the entire monomer component constituting the acrylic polymer is
  • the total content of (meth)acrylic acid C 10-14 alkyl ester and a monomer having a nitrogen atom (preferably a monomer having a nitrogen atom-containing ring) may be 8% by weight or more (for example, 10% by weight or more). It is preferably 15% by weight or more (for example, 20% by weight or more), still more preferably 25% by weight or more, may be 30% by weight or more, or may be 35% by weight or more.
  • the total of (meth)acrylic acid C 10-14 alkyl ester and a monomer having a nitrogen atom (preferably a monomer having a nitrogen atom-containing ring) in the entire monomer components constituting the acrylic polymer The content may be 95% by weight or less, 90% by weight or less, 80% by weight or less, 70% by weight or less, 60% by weight or less, or 50% by weight or less.
  • the proportion of the carboxy group-containing monomer in the monomer components of the acrylic polymer may be, for example, less than 10% by weight, may be less than 3% by weight, and may be less than 1% by weight (for example, 0.1% by weight). (less than %). It is not necessary to substantially use a carboxy group-containing monomer as a monomer component of the acrylic polymer.
  • substantially not using a carboxy group-containing monomer means not using a carboxy group-containing monomer at least intentionally.
  • An acrylic polymer having such a composition can have metal corrosion inhibiting properties for adherends containing metal.
  • the composition of the monomer components constituting the acrylic polymer can be set so that the glass transition temperature Tg determined by the Fox equation is -75°C or more and 10°C or less based on the composition of the monomer components.
  • the above Tg is suitably 0°C or lower, preferably -10°C or lower, and -20°C or lower or -30°C or lower, from the viewpoint of adhesive strength or the like. Good too.
  • the Tg may be, for example, -60°C or higher, -50°C or higher, -45°C or higher, or -40°C or higher.
  • Tg is the glass transition temperature of the copolymer (unit: K)
  • Wi is the weight fraction of monomer i in the copolymer (copolymerization ratio on a weight basis)
  • Tgi is the weight fraction of monomer i in the copolymer.
  • the glass transition temperature of the homopolymer used to calculate Tg As the glass transition temperature of the homopolymer used to calculate Tg, the numerical value described in publicly known materials, specifically "Polymer Handbook” (3rd edition, John Wiley & Sons, Inc., 1989) shall be used. . If multiple types of values are listed in this document, the highest value is adopted.
  • thermal polymerization initiator In the polymerization, a known or commonly used thermal polymerization initiator or photopolymerization initiator may be used depending on the polymerization method, polymerization mode, etc.
  • the thermal polymerization initiator is not particularly limited, but includes, for example, an azo polymerization initiator, a peroxide initiator, a redox initiator based on a combination of a peroxide and a reducing agent, and a substituted ethane initiator. etc. can be used.
  • the photopolymerization initiator is not particularly limited, but includes, for example, a ketal photopolymerization initiator, an acetophenone photopolymerization initiator, a benzoin ether photopolymerization initiator, an acylphosphine oxide photopolymerization initiator, and an ⁇ - Ketol photoinitiator, aromatic sulfonyl chloride photoinitiator, photoactive oxime photoinitiator, benzoin photoinitiator, benzyl photoinitiator, benzophenone photoinitiator, thioxanthone photoinitiator A polymerization initiator or the like can be used.
  • the polymerization initiators can be used alone or in an appropriate combination of two or more.
  • the amount of such a thermal polymerization initiator or photopolymerization initiator to be used can be a normal amount depending on the polymerization method, polymerization mode, etc., and is not particularly limited.
  • approximately 0.001 to 5 parts by weight (typically approximately 0.01 to 2 parts by weight, for example approximately 0.01 to 1 part by weight) of a polymerization initiator may be used for 100 parts by weight of the monomer to be polymerized. Can be done.
  • chain transfer agents which can also be understood as molecular weight regulators or polymerization degree regulators
  • chain transfer agent mercaptans such as n-dodecylmercaptan, t-dodecylmercaptan, thioglycolic acid, and ⁇ -thioglycerol
  • a chain transfer agent that does not contain sulfur atoms non-sulfur chain transfer agent
  • One type of chain transfer agent can be used alone or two or more types can be used in combination.
  • the amount used can be, for example, approximately 0.01 to 1 part by weight per 100 parts by weight of the monomer component.
  • the technology disclosed herein can also be preferably practiced in an embodiment that does not use a chain transfer agent.
  • the molecular weight of the acrylic polymer obtained by appropriately employing the various polymerization methods described above is not particularly limited, and can be set within an appropriate range depending on the required performance.
  • the weight average molecular weight (Mw) of the acrylic polymer is, for example, approximately 10 ⁇ 10 4 or more, and from the viewpoint of achieving both cohesive force and adhesive force in a well-balanced manner, it is appropriate to set it to more than 30 ⁇ 10 4 .
  • the acrylic polymer according to some embodiments preferably has a Mw of about 50 ⁇ 10 4 or more.
  • the upper limit of Mw of the acrylic polymer may be approximately 500 ⁇ 10 4 or less (for example, approximately 150 ⁇ 10 4 or less).
  • the Mw may be approximately 75 ⁇ 10 4 or less.
  • Mw refers to a standard polystyrene equivalent value obtained by gel permeation chromatography (GPC).
  • GPC gel permeation chromatography
  • a model name "HLC-8320GPC” columnumn: TSKgelGMH-H(S), manufactured by Tosoh Corporation
  • TSKgelGMH-H(S) manufactured by Tosoh Corporation
  • the adhesive disclosed herein includes a monomer component having the composition described above in the form of a polymerized product, an unpolymerized product (that is, a form in which the polymerizable functional group is unreacted), or a mixture thereof.
  • the above adhesive compositions include water-dispersed adhesive compositions in which the adhesive (adhesive component) is dispersed in water, solvent-based adhesive compositions in which the adhesive is contained in an organic solvent, and UV and radiation resistant adhesive compositions.
  • An active energy ray-curable adhesive composition prepared to be cured by active energy rays to form an adhesive, and a hot melt adhesive composition that is applied in a heated molten state and forms an adhesive when cooled to around room temperature. It can be in various forms such as a composition.
  • the adhesive composition is a solvent-based adhesive composition or a solvent-free adhesive composition.
  • Solvent-free adhesive compositions include active energy ray-curable adhesive compositions and hot-melt adhesive compositions.
  • the alcohol peeling disclosed herein is a solvent-based adhesive formed from a solvent-based adhesive composition, and an active energy ray-curable adhesive composition formed from an active energy ray (typically ultraviolet curing) curable adhesive composition. Effective against adhesives (typically UV-curable adhesives).
  • the adhesive composition according to some embodiments may be an active energy ray-curable adhesive composition.
  • active energy rays refer to energy rays with energy capable of causing chemical reactions such as polymerization reactions, crosslinking reactions, and decomposition of initiators.
  • Examples of active energy rays herein include light such as ultraviolet rays, visible rays, and infrared rays, and radiation such as ⁇ rays, ⁇ rays, ⁇ rays, electron rays, neutron rays, and X rays.
  • a preferred example of the active energy ray-curable adhesive composition is a photocurable adhesive composition.
  • a photocurable pressure-sensitive adhesive composition has the advantage that even a thick pressure-sensitive adhesive layer can be easily formed. Among these, UV-curable pressure-sensitive adhesive compositions are preferred.
  • a photocurable pressure-sensitive adhesive composition typically contains at least a portion of the monomer components of the composition (which may be a portion of the type of monomer or a portion of the amount). Contains in the form of polymers.
  • the polymerization method used to form the above-mentioned polymer is not particularly limited, and various conventionally known polymerization methods can be employed as appropriate.
  • thermal polymerization such as solution polymerization, emulsion polymerization, and bulk polymerization (typically carried out in the presence of a thermal polymerization initiator); photopolymerization carried out by irradiating light such as ultraviolet rays (typically carried out in the presence of a thermal polymerization initiator); (Carried out in the presence of a photopolymerization initiator); Radiation polymerization carried out by irradiation with radiation such as ⁇ rays and ⁇ rays; etc. can be employed as appropriate. Among these, photopolymerization is preferred.
  • Photocurable pressure-sensitive adhesive compositions include a partial polymer of monomer components (for example, an acrylic partial polymer).
  • a partially polymerized product is typically a mixture of a polymer derived from a monomer component and an unreacted monomer, and preferably takes the form of a syrup (viscous liquid).
  • a partially polymerized product having such properties may be referred to as "monomer syrup” or simply “syrup.”
  • the polymerization method for partially polymerizing the monomer components is not particularly limited, and various polymerization methods such as those described above can be appropriately selected and used. From the viewpoint of efficiency and convenience, a photopolymerization method can be preferably employed. According to photopolymerization, the polymerization conversion rate (monomer conversion) of monomer components can be easily controlled by controlling the polymerization conditions such as the amount of light irradiation (light amount).
  • the polymerization conversion rate of the monomer mixture in the above partially polymerized product is not particularly limited.
  • the above polymerization conversion rate can be, for example, about 70% by weight or less, and from the viewpoint of ease of preparation and coatability of the adhesive composition containing the above partially polymerized product, it is suitably about 50% by weight or less. , preferably about 40% by weight or less.
  • the lower limit of the polymerization conversion rate is not particularly limited, it is typically about 1% by weight or more, and suitably about 5% by weight or more.
  • the adhesive composition containing the above partially polymerized product may contain other components used as necessary (for example, a photopolymerization initiator, a surfactant as described below, a crosslinking agent, a polyfunctional monomer, an acrylic oligomer, etc.). , tackifier resin, silane coupling agent, etc.) may be blended.
  • the method of blending such other components is not particularly limited, and for example, they may be included in the monomer mixture in advance, or may be added to the partially polymerized product.
  • the adhesive is an adhesive formed from a water-dispersed adhesive composition.
  • a typical example of a water-dispersed adhesive composition is an emulsion-type adhesive composition.
  • An emulsion type adhesive composition typically contains a polymer of monomer components and additives used as necessary. Emulsion polymerization of monomer components is usually carried out in the presence of an emulsifier. According to emulsion polymerization, a polymerization reaction solution in the form of an emulsion in which a polymer of monomer components is dispersed in water is obtained.
  • a water-dispersed adhesive composition used for forming an adhesive can be preferably manufactured using the above polymerization reaction liquid.
  • the emulsifier for emulsion polymerization is not particularly limited, and known anionic emulsifiers, nonionic emulsifiers, etc. can be used.
  • the emulsifiers can be used alone or in combination of two or more.
  • anionic emulsifiers include sodium lauryl sulfate, ammonium lauryl sulfate, sodium dodecylbenzenesulfonate, sodium polyoxyethylene lauryl sulfate, sodium polyoxyethylene alkyl ether sulfate, ammonium polyoxyethylene alkylphenyl ether sulfate, Examples include sodium ethylene alkyl phenyl ether sulfate and sodium polyoxyethylene alkyl sulfosuccinate.
  • Non-limiting examples of nonionic emulsifiers include polyoxyethylene alkyl ethers, polyoxyethylene alkyl phenyl ethers, polyoxyethylene fatty acid esters, polyoxyethylene polyoxypropylene block polymers, and the like.
  • An emulsifier having a reactive functional group may also be used.
  • the reactive emulsifier include radically polymerizable emulsifiers having a structure in which a radically polymerizable functional group such as a propenyl group or an allyl ether group is introduced into the above-mentioned anionic emulsifier or nonionic emulsifier.
  • the amount of emulsifier used in emulsion polymerization may be, for example, 0.2 parts by weight or more, 0.5 parts by weight or more, 1.0 parts by weight or more, based on 100 parts by weight of the monomer components.
  • the amount may be 5 parts by weight or more.
  • the amount of emulsifier used is 10 parts by weight or less per 100 parts by weight of the monomer component. , is preferably 5 parts by weight or less, and may be 3 parts by weight or less.
  • the emulsifier used in the emulsion polymerization here can also function as a surfactant, which will be described later.
  • the adhesive composition according to some embodiments may be a solvent-based adhesive composition.
  • a solvent-based adhesive composition typically contains a solution polymer of monomer components and additives used as necessary.
  • the solvent (polymerization solvent) used in solution polymerization can be appropriately selected from conventionally known organic solvents (for example, toluene, ethyl acetate, etc.).
  • a polymerization reaction solution is obtained in which a polymer of monomer components is dissolved in a polymerization solvent.
  • the solvent-based adhesive composition disclosed herein can be preferably manufactured using the above polymerization reaction solution.
  • the adhesive includes a surfactant.
  • a surfactant By incorporating a surfactant into the adhesive, it is possible to effectively reduce the peeling force using an alcohol solution, thereby improving the alcohol peelability.
  • the reason for this is not particularly limited, but in general, surfactants tend to be unevenly distributed on the surface of the adhesive because they have a hydrophilic region, thereby effectively increasing the water affinity of the surface of the adhesive. It is considered that this effect effectively reduces the peeling force when the adhesive comes into contact with an alcohol solution, and improves the alcohol peelability.
  • the above-mentioned surfactant is typically contained in the adhesive composition (and thus the adhesive) in a free form.
  • the surfactant one that is liquid at room temperature (about 25° C.) can be preferably used from the viewpoint of ease of preparing the adhesive composition.
  • One kind of surfactant can be used alone or two or more kinds can be used in combination.
  • nonionic surfactants known nonionic surfactants, anionic surfactants, cationic surfactants, etc. can be used. Among these, nonionic surfactants are preferred.
  • One kind of surfactant can be used alone or two or more kinds can be used in combination.
  • nonionic surfactants include polyoxyethylene alkyl ethers such as polyoxyethylene lauryl ether, polyoxyethylene cetyl ether, polyoxyethylene stearyl ether, and polyoxyethylene oleyl ether; polyoxyethylene octylphenyl ether, and polyoxyethylene alkyl ether; Polyoxyethylene alkylphenyl ethers such as oxyethylene nonylphenyl ether; Sorbitan fatty acid esters such as sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate, and sorbitan monooleate; polyoxyethylene sorbitan monolaurate, polyoxyethylene Polyoxyethylene sorbitans such as sorbitan monopalmitate, polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan tristearate, polyoxyethylene sorbitan triisostearate, polyoxyethylene sorbitan monooleate, polyoxyethylene sorbitan trioleate, etc.
  • anionic surfactants include alkyl sulfates such as lauryl sulfate and octadecyl sulfate; fatty acid salts; alkylbenzenesulfonates such as nonylbenzenesulfonate and dodecylbenzenesulfonate; dodecylnaphthalenesulfonate, etc.
  • alkyl diphenyl ether disulfonate such as dodecyl diphenyl ether disulfonate
  • polyoxyethylene alkyl ether sulfate such as polyoxyethylene octadecyl ether sulfate, polyoxyethylene lauryl ether sulfate; polyoxyethylene lauryl phenyl ether
  • Polyoxyethylene alkyl phenyl ether sulfates such as sulfates; polyoxyethylene styrenated phenyl ether sulfates; sulfosuccinates such as lauryl sulfosuccinate and polyoxyethylene lauryl sulfosuccinate; polyoxyethylene alkyl ether phosphates; Examples include polyoxyethylene alkyl ether acetate; and the like.
  • the salt may be, for example, a metal salt (preferably a monovalent metal salt) such as a sodium salt, a potassium salt, a calcium salt, a magnesium salt, an ammonium salt, an amine salt, etc. It can be.
  • a metal salt preferably a monovalent metal salt
  • anionic surfactants can be used alone or in combination of two or more.
  • the content of the surfactant in the adhesive is not particularly limited, and can be set so that the effect of using the surfactant is appropriately exhibited.
  • the content of the surfactant can be, for example, 0.001 parts by weight or more per 100 parts by weight of the polymer (for example, acrylic polymer) contained in the adhesive, and 0.01 parts by weight.
  • the amount is suitably at least 0.05 parts by weight, preferably at least 0.05 parts by weight, and more preferably at least 0.1 parts by weight.
  • the content of the surfactant may be, for example, 1.0 parts by weight or more, or 1.5 parts by weight or more, based on 100 parts by weight of the polymer contained in the adhesive.
  • the amount of the surfactant used can be about 3 parts by weight or less, preferably about 2 parts by weight or less, based on 100 parts by weight of the polymer, Preferably it is less than 1 part by weight, more preferably less than 0.5 part by weight. By limiting the amount of surfactant used, it tends to be easier to maintain adhesive strength.
  • polyfunctional monomer A polyfunctional monomer may be used in the adhesive composition (and thus the adhesive) as necessary. Multifunctional monomers can serve for purposes such as adjusting cohesion.
  • the polyfunctional monomer forms a crosslinked structure with appropriate flexibility by reacting the above ethylenically unsaturated groups with light (e.g. ultraviolet light) irradiation when forming the adhesive layer or after pasting it on the adherend. It is possible. Therefore, in this specification, the term "polyfunctional monomer” can be interpreted as a crosslinking agent.
  • polyfunctional monomers can be preferably used in adhesives formed from photocurable adhesive compositions.
  • a compound having two or more ethylenically unsaturated groups can be used.
  • One type of polyfunctional monomer can be used alone or two or more types can be used in combination.
  • Examples of ethylenically unsaturated groups possessed by the polyfunctional monomer include, but are not limited to, acryloyl groups, methacryloyl groups, vinyl groups, and allyl groups.
  • Preferred ethylenically unsaturated groups from the viewpoint of photoreactivity include acryloyl and methacryloyl groups. Among them, an acryloyl group is preferred.
  • polyfunctional monomers examples include ethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, and neopentyl glycol di(meth)acrylate.
  • the amount of the polyfunctional monomer used varies depending on its molecular weight, number of functional groups, etc.; ) Appropriately, the amount is in the range of about 0.01 parts by weight to 3.0 parts by weight per 100 parts by weight.
  • the adhesive composition disclosed herein may contain a crosslinking agent as necessary, mainly for the purpose of crosslinking within the adhesive (layer) or between the adhesive and its adjacent surface.
  • the type of crosslinking agent is not particularly limited, and may be selected from among conventionally known crosslinking agents so that the crosslinking agent exhibits an appropriate crosslinking function within the adhesive, depending on the composition of the adhesive composition, for example. Can be done.
  • crosslinking agents examples include isocyanate crosslinking agents, epoxy crosslinking agents, oxazoline crosslinking agents, aziridine crosslinking agents, carbodiimide crosslinking agents, melamine crosslinking agents, urea crosslinking agents, metal alkoxide crosslinking agents, and metals.
  • examples include chelate crosslinking agents, metal salt crosslinking agents, hydrazine crosslinking agents, and amine crosslinking agents. These can be used alone or in combination of two or more.
  • the content of the crosslinking agent (if two or more types of crosslinking agents are included, the total amount thereof) is not particularly limited. From the perspective of realizing a pressure-sensitive adhesive that exhibits adhesive properties such as adhesive strength and cohesive force in a well-balanced manner, the content of the crosslinking agent is determined by the amount of crosslinking agent contained in the pressure-sensitive adhesive. It is appropriate that the amount is approximately 5 parts by weight or less, preferably approximately 0.001 to 5 parts by weight, and approximately 0.001 to 4 parts by weight per 100 parts by weight of the monomer component of the polymer. More preferably, the amount is about 0.001 to 3 parts by weight. Alternatively, the pressure-sensitive adhesive composition may not contain a crosslinking agent as described above.
  • the adhesive composition may be substantially free of crosslinking agents such as isocyanate crosslinking agents.
  • crosslinking agent typically an isocyanate-based crosslinking agent
  • the amount of the crosslinking agent is less than 0.05 parts by weight (for example, 0.05 parts by weight) based on 100 parts by weight of the monomer components. 01 parts by weight).
  • a crosslinking catalyst may be used to advance the crosslinking reaction more effectively.
  • the adhesive composition used to form the adhesive may contain a crosslinking retarder (for example, a compound that causes keto-enol tautomerism), if desired.
  • the amounts of the crosslinking catalyst and crosslinking retarder to be used are not limited to a specific range, and are used in appropriate amounts depending on the purpose and the like.
  • the adhesive may contain a tackifying resin.
  • the tackifier resin include rosin-based tackifier resin, rosin derivative tackifier resin, petroleum-based tackifier resin, terpene-based tackifier resin, phenol-based tackifier resin, ketone-based tackifier resin, and the like. These can be used alone or in combination of two or more. Among these, one or more selected from rosin-based tackifier resins, rosin derivative tackifier resins, and terpene phenol resins can be preferably used.
  • a tackifying resin (preferably a rosin derivative tackifying resin) having a softening point of 80° C. or higher (for example, 120° C. or higher and 180° C. or lower) can be preferably used.
  • the amount of the tackifying resin to be used is preferably 1 part by weight or more per 100 parts by weight of the monomer component constituting the polymer contained in the adhesive, from the viewpoint of suitably exhibiting the effect of its use. It may be at least 10 parts by weight, at least 15 parts by weight, at least 20 parts by weight, or at least 25 parts by weight. Further, from the viewpoint of achieving both adhesion to the adherend and cohesiveness in a well-balanced manner, the amount of the tackifying resin used per 100 parts by weight of the monomer component may be, for example, 50 parts by weight or less, or 30 parts by weight or less. Alternatively, the content of the tackifying resin in the adhesive may be, for example, less than 1 part by weight per 100 parts by weight of the monomer component, and the adhesive may be substantially free of tackifying resin. It's okay.
  • the adhesive disclosed herein can contain an acrylic oligomer from the viewpoint of improving cohesive force and adhesion.
  • an acrylic oligomer it is preferable to use a polymer whose Tg is higher than that of the acrylic polymer.
  • acrylic oligomers are suitable because they are less likely to inhibit polymerization.
  • acrylic oligomers include dicyclopentanyl methacrylate (DCPMA), cyclohexyl methacrylate (CHMA), isobornyl methacrylate (IBXMA), isobornyl acrylate (IBXA), and dicyclopentanyl acrylate (DCPA). , 1-adamantyl methacrylate (ADMA), and 1-adamantyl acrylate (ADA), as well as copolymers of DCPMA and methyl methacrylate (MMA), copolymers of DCPMA and IBXMA, and copolymers of ADA and MMA.
  • DCPMA dicyclopentanyl methacrylate
  • CHMA cyclohexyl methacrylate
  • IBXMA isobornyl methacrylate
  • IBXA isobornyl acrylate
  • DCPA dicyclopentanyl acrylate
  • ADMA 1-adamantyl methacrylate
  • ADA 1-adamantyl acrylate
  • Polymers copolymers of CHMA and isobutyl methacrylate (IBMA), copolymers of CHMA and IBXMA, copolymers of CHMA and acryloylmorpholine (ACMO), copolymers of CHMA and diethylacrylamide (DEAA) , a copolymer of CHMA and AA, and the like.
  • Acrylic oligomers can be used alone or in combination of two or more.
  • the Mw of the acrylic oligomer is typically about 1,000 or more and less than about 30,000, preferably about 1,500 or more and less than about 10,000, and more preferably about 2,000 or more and less than about 5,000. When Mw is within the above range, the effect of improving cohesion and adhesion to adjacent surfaces is likely to be suitably exhibited.
  • the Mw of the acrylic oligomer can be measured by gel permeation chromatography (GPC) and determined as a value in terms of standard polystyrene. Specifically, the measurement is performed using HPLC8020 manufactured by Tosoh Corporation with two columns of TSKgelGMH-H (20) at a flow rate of about 0.5 mL/min using tetrahydrofuran solvent.
  • the content can be, for example, 0.01 part by weight or more based on 100 parts by weight of the base polymer (typically an acrylic polymer), and more From the viewpoint of obtaining high effects, the amount may be 0.05 part by weight or more, or may be 0.1 part by weight or more. Further, from the viewpoint of compatibility with the base polymer, the content of the acrylic oligomer is preferably less than 30 parts by weight, and may be, for example, 10 parts by weight or less, or 1 part by weight or less.
  • the adhesive disclosed herein may also include a silane coupling agent.
  • the silane coupling agent is preferably contained in the adhesive composition (and thus the adhesive) in a free form.
  • the adhesive strength of the adhesive to an adherend tends to increase.
  • a silane coupling agent a silicon compound having an epoxy structure such as 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane; Amino group-containing silicon compounds such as 3-aminopropyltrimethoxysilane, N-(2-aminoethyl)3-aminopropyltrimethoxysilane, N-(2-aminoethyl)3-aminopropylmethyldimethoxysilane; 3-chloro Propyltrimethoxysilane; acetoacetyl group-containing trimethoxysilane; (meth)acrylic group-containing silane coupling agents such as 3-acryloxypropyltrimethoxysilane and 3-methacryloxypropyltriethoxysilane; 3-isocyanatepropyltriethoxysilane
  • the amount of the silane coupling agent used can be set so as to obtain the desired effect of use, and is not particularly limited.
  • the amount of the silane coupling agent used may be, for example, 0.001 parts by weight or more based on 100 parts by weight of the monomer components constituting the polymer contained in the adhesive, to achieve a higher effect. From the viewpoint of obtaining, the amount may be 0.005 part by weight or more, 0.01 part by weight or more, or 0.015 part by weight or more. Further, in some embodiments, the amount of the silane coupling agent used may be, for example, 3 parts by weight or less, 1 part by weight or less, and 0.5 parts by weight or less, based on 100 parts by weight of the monomer components constituting the adhesive.
  • the technology disclosed herein can be implemented in an embodiment using an adhesive that does not substantially contain a silane coupling agent. By limiting the amount of the silane coupling agent used or not using the silane coupling agent, the releasability from the adherend tends to improve.
  • the adhesive disclosed herein may optionally contain a viscosity modifier (e.g., thickener), a pH adjuster, a leveling agent, a plasticizer, a filler, a coloring agent such as a pigment or dye, a stabilizer, and a preservative.
  • a viscosity modifier e.g., thickener
  • a pH adjuster e.g., a pH adjuster
  • a leveling agent e.g., a leveling agent
  • a plasticizer e.g., a leveling agent
  • a plasticizer e.g., ethylene glycol dimethacrylate, ethylene glycol dimethacrylate, ethylene glycol dimethacrylate, ethylene glycol dimethacrylate, ethylene glycol dimethacrylate, ethylene glycol dimethacrylate, ethylene glycol dimethacrylate, ethylene glycol dimethacrylate, ethylene glycol dimethacrylate, ethylene glycol dimethacrylate
  • the amount of components other than the base polymer (preferably acrylic polymer) in the adhesive may be limited.
  • the amount of components other than the base polymer in the adhesive is, for example, about 30% by weight or less, suitably about 15% by weight or less, preferably about 12% by weight or less ( For example, about 10% by weight or less).
  • a pressure-sensitive adhesive having such a composition easily satisfies predetermined optical properties (eg, transparency) and can be preferably used for optical applications.
  • the amount of components other than the base polymer in the adhesive may be about 5% by weight or less, about 3% by weight or less, about 1.5% by weight or less (e.g., about 1% by weight or less).
  • a composition in which the amount of components other than the base polymer (eg, acrylic polymer) is limited in this way can be preferably employed in a photocurable pressure-sensitive adhesive composition.
  • the adhesive layer may be a cured layer of the adhesive composition. That is, the adhesive layer can be formed by applying (for example, coating) an adhesive composition to a suitable surface and then appropriately performing a curing treatment. When performing two or more types of curing treatments (drying, crosslinking, polymerization, etc.), these can be performed simultaneously or in multiple stages. In pressure-sensitive adhesive compositions using partial polymers of monomer components (acrylic polymer syrup), a final copolymerization reaction is typically performed as the curing treatment. That is, the partially polymerized product is further subjected to a copolymerization reaction to form a complete polymerized product.
  • a photocurable adhesive composition for example, in the case of a photocurable adhesive composition, light irradiation is performed. Curing treatments such as crosslinking and drying may be performed as necessary. For example, if it is necessary to dry the photocurable adhesive composition (for example, in the case of a photocurable adhesive composition in which a partial polymer of a monomer component is dissolved in an organic solvent), dry the composition. It is preferable to perform photocuring after this. In an adhesive composition using a complete polymer, typically, as the curing treatment, treatments such as drying (heat drying) and crosslinking are performed as necessary.
  • An adhesive layer having a multilayer structure of two or more layers can be produced by bonding together adhesive layers formed in advance. Alternatively, a second adhesive layer may be formed by applying a pressure-sensitive adhesive composition onto a first pressure-sensitive adhesive layer formed in advance and curing the pressure-sensitive adhesive composition.
  • the adhesive composition can be applied using a conventional coater such as a gravure roll coater, a reverse roll coater, a kiss roll coater, a dip roll coater, a bar coater, a knife coater, and a spray coater.
  • a conventional coater such as a gravure roll coater, a reverse roll coater, a kiss roll coater, a dip roll coater, a bar coater, a knife coater, and a spray coater.
  • the thickness of the adhesive layer is not particularly limited, and may be, for example, about 3 ⁇ m to 2000 ⁇ m. In some embodiments, the thickness of the adhesive layer is suitably 3 ⁇ m or more, preferably 10 ⁇ m or more, and more preferably 15 ⁇ m or more, from the viewpoint of adhesion to the adherend such as step followability. The thickness is more preferably 20 ⁇ m or more. Further, from the viewpoint of preventing adhesive residue from occurring due to cohesive failure of the adhesive layer, in some embodiments, the thickness of the adhesive layer is usually 500 ⁇ m or less, preferably 200 ⁇ m or less, and more preferably 100 ⁇ m or less. The thickness may be 50 ⁇ m or less, or even 30 ⁇ m or less.
  • the adhesive is preferably an optical adhesive.
  • the optical adhesive may be one that does not impair optical properties.
  • the haze value of the adhesive (layer) and ultimately the adhesive sheet is not particularly limited, but in some embodiments, it is appropriate that the haze value is approximately 10% or less, and approximately 5% or less (for example, approximately 3% or less). It can be.
  • the haze value is preferably 1.0% or less. Adhesives with such high transparency are suitable for optical applications that require high light transmittance.
  • the haze value may be less than 1.0%, may be less than 0.7%, and may be 0.5% or less (for example, 0 to 0.5%).
  • the haze value can be adjusted, for example, by selecting the composition and thickness of the adhesive.
  • the "haze value” refers to the ratio of diffusely transmitted light to the total transmitted light when visible light is irradiated onto the measurement target. Also called cloudiness value.
  • the haze value is determined by pasting the adhesive side of the adhesive layer or adhesive sheet on one side of alkali glass with a haze value of 0.1% to form a laminate of the adhesive layer or adhesive sheet and alkali glass, and then using a haze meter (for example, Murakami).
  • the alkali glass to which the adhesive layer or adhesive sheet is attached is placed so that the adhesive layer or adhesive sheet faces the light source side. Since the haze value of alkali glass is 0.1%, the value obtained by subtracting 0.1% from the measured value is defined as the haze value [%] of the adhesive layer or adhesive sheet.
  • the adhesive sheet includes a base layer.
  • the base layer is a support (support layer) that supports the adhesive layer.
  • the base layer may be an intermediate layer disposed between the first and second adhesive layers that constitute the surface of the adhesive sheet.
  • Examples of the base layer disclosed herein include various resin films such as polyolefin film, polyester film, and polyvinyl chloride film; foam sheets made of foams such as polyurethane foam, polyethylene foam, and polychloroprene foam; Woven fabrics and non-woven fabrics made of fibrous materials (natural fibers such as hemp and cotton, synthetic fibers such as polyester and vinylon, semi-synthetic fibers such as acetate, etc.) alone or in combination; Japanese paper, high-quality paper, and crafts. Examples include papers such as paper and crepe paper; metal foils such as aluminum foil, copper foil, and stainless steel (SUS); and the like. A layered body having a composite structure of these may also be used.
  • base material layers with such composite structures include, for example, laminated base materials with a structure in which metal foil and the above-mentioned resin film are laminated (multilayer base materials), resin sheets reinforced with inorganic fibers such as glass cloth, etc. can be mentioned.
  • the material for the base layer a material containing a base film that can independently maintain its shape (self-supporting or independent) can be preferably used.
  • the term "resin film” refers to a resin film that has a non-porous structure and typically is substantially void-free. Therefore, the resin film is a concept that is distinguished from foam films and nonwoven fabrics.
  • the resin film may have a single-layer structure or a multi-layer structure of two or more layers (for example, a three-layer structure).
  • the resin film may be a transparent film. Transparent resin films are suitable for optical applications.
  • Suitable examples of the resin material constituting the resin film include polyester resin, polyphenylene sulfide (PPS) resin, polyolefin resin, and polyimide resin.
  • resin films that can be preferably used as the base layer include polyethylene terephthalate (PET) film, polyethylene naphthalate (PEN) film, PPS film, polyetheretherketone (PEEK) film, transparent polyimide (CPI) film, and polypropylene.
  • PET polyethylene terephthalate
  • PEN polyethylene naphthalate
  • PPS film polyetheretherketone
  • CPI transparent polyimide
  • TAC triacetyl cellulose
  • Preferred examples from the viewpoint of strength include PET film, PEN film, PPS film, PEEK film, and CPI film.
  • Preferred examples from the viewpoint of availability, dimensional stability, optical properties, etc. include PET film, CPI film, and TAC film.
  • additives such as light stabilizers, antioxidants, antistatic agents, colorants (dyes, pigments, etc.), fillers, slip agents, anti-blocking agents, etc. may be added to the resin film as necessary. Can be done.
  • the amount of additives to be blended is not particularly limited, and can be appropriately set depending on the application and the like.
  • the method for producing the resin film is not particularly limited.
  • conventionally known general resin film forming methods such as extrusion molding, inflation molding, T-die casting molding, and calender roll molding can be appropriately employed.
  • the base material layer may be substantially composed of such a resin film.
  • the base layer may include an auxiliary layer in addition to the resin film.
  • auxiliary layers include surface treatment layers such as undercoat layers and release layers.
  • the surface of the base material layer on the adhesive layer side may be treated with corona treatment, plasma treatment, ultraviolet irradiation treatment, acid treatment, alkali treatment, application of an undercoat (primer), antistatic treatment, peeling, etc., as necessary.
  • a conventionally known surface treatment such as a treatment may be applied.
  • the thickness of the base material layer is not particularly limited, and may be, for example, approximately 1000 ⁇ m or less, approximately 500 ⁇ m or less, and from the viewpoint of weight reduction and thinning, approximately 100 ⁇ m or less is appropriate, and may be 70 ⁇ m or less. Further, from the viewpoint of handleability, processability, etc., the thickness of the base material layer may be, for example, 1 ⁇ m or more, suitably about 20 ⁇ m or more, and preferably about 30 ⁇ m or more.
  • a method for peeling an adhesive sheet pasted on an adherend comprising: comprising applying an adhesive force reducing means to the adhesive sheet,
  • the adhesive force reducing means is supplying an alcohol solution to an interface between the adherend and the adhesive sheet at a peeling front of the adhesive sheet from the adherend;
  • a peeling method comprising moving a peeling front in a peeling advancing direction and allowing the alcohol solution to enter the interface following the movement of the peeling front.
  • the adhesive sheet is prepared by attaching the adhesive sheet to a stainless steel plate as an adherend, and after one day at room temperature, dropping 2 ⁇ L of ethanol onto the adherend, and applying the ethanol to the adhesive sheet and the adherend.
  • the adhesive sheet was prepared by pasting the adhesive sheet cut into a rectangular shape with a width of 20 mm on a stainless steel plate as an adherend, and after one day at room temperature, dropping 2 ⁇ L of ethanol onto the adherend.
  • Method 1 180° peeling adhesive force to the test plate, specifically, In (1) or (2) above, the adhesive strength reduction distance R SUS is 30 mm or more, measured at a test temperature of 23 ° C. using a tensile tester at a tensile speed of 300 mm/min and a peel angle of 180 degrees. Peeling method described.
  • the adhesive sheet described in (1) to (3) above has an adhesive force N0 SUS of 3.0 N/20 mm or more after one day at room temperature after pasting the adhesive sheet on a stainless steel plate as an adherend. The peeling method described in any of the above.
  • the adhesive sheet includes: After one day at room temperature after pasting the adhesive sheet on a stainless steel plate as an adherend, 2 ⁇ L of ethanol is dropped onto the adherend, and the ethanol is allowed to enter one end of the interface between the adhesive sheet and the adherend.
  • Method 1 180° peeling adhesive force to the test plate, specifically, at a test temperature of 23 ° C. Peeling according to any one of (1) to (4) above, wherein the adhesive force reduction distance R SUS is 30 mm or more, measured using a tensile tester at a tensile speed of 300 mm/min and a peel angle of 180 degrees. Method. (6) The adhesive sheet is prepared by attaching the adhesive sheet to an alkali glass plate prepared by the float method as an adherend, and after one day at room temperature, dropping 2 ⁇ L of ethanol onto the adherend, and adding the ethanol to the adherend.
  • Method 1 180° peeling adhesive force to the test plate, specifically, test temperature 23 (1) to (5) above, where the ethanol peel force N1 GLA is 0.5 N/20 mm or less, measured using a tensile tester at °C at a tensile speed of 300 mm/min and a peel angle of 180 degrees. The peeling method described in any of the above. (7) The adhesive sheet was cut into a rectangular shape with a width of 20 mm and was pasted on an alkali glass plate made by the float method as an adherend, and after one day at room temperature, 2 ⁇ L was applied to the adherend.
  • the adhesive sheet has an adhesive force N0 GLA of 3.0 N/20 mm or more after one day at room temperature after attaching the adhesive sheet to an alkali glass plate prepared by a float method as an adherend.
  • the adhesive sheet includes: The adhesive sheet was attached to an alkali glass plate prepared by the float method as an adherend, and after one day at room temperature, 2 ⁇ L of ethanol was dropped onto the adherend, and the ethanol was applied to the adhesive sheet and the adherend.
  • the adhesive sheet includes a base layer and an adhesive layer disposed on at least one surface of the base layer, The peeling method according to any one of (1) to (9) above, wherein the adhesive layer is an acrylic adhesive layer containing an acrylic polymer as a base polymer.
  • the adhesive layer is formed from a water-dispersed adhesive composition, a solvent-based adhesive composition, an active energy ray-curable adhesive composition, or a hot-melt adhesive composition.
  • (12) The peeling method according to (10) or (11) above, wherein the base layer is composed of a resin film.
  • the adherend has a contact angle with ethanol of 50 degrees or less, 30 degrees or less, 20 degrees or less, or 15 degrees or less on the surface of the adherend to which the pressure-sensitive adhesive sheet is attached, according to (1) above.
  • the adherend has a contact angle with respect to distilled water on the surface to which the adhesive sheet is attached, of 30 degrees or more, 35 degrees or more, 40 degrees or more, 45 degrees or more, 50 degrees or more, or 60 degrees or more.
  • the peeling method according to any one of (1) to (13) above, wherein the peeling method is at least 60 degrees or more than 60 degrees.
  • Adhesive composition S-1 Into a reaction vessel equipped with a cooling tube, a nitrogen introduction tube, a thermometer, and a stirring device, 38.5 parts of 2-ethylhexyl acrylate (2EHA), 60 parts of lauryl acrylate (LA), and 2.5 parts of n-butyl acrylate (BA) were added. , 8 parts of 4-hydroxybutyl acrylate (4HBA), 0.05 parts of N-vinyl-2-pyrrolidone (NVP), and 0.0 parts of 2,2'-azobisisobutyronitrile (AIBN) as a thermal polymerization initiator.
  • 2EHA 2-ethylhexyl acrylate
  • LA lauryl acrylate
  • BA n-butyl acrylate
  • 4HBA 4-hydroxybutyl acrylate
  • NDP N-vinyl-2-pyrrolidone
  • AIBN 2,2'-azobisisobutyronitrile
  • a solution containing acrylic polymer A with an Mw of 600,000 to 1,000,000 (solid content concentration 30%) was prepared by adding 2 parts of acrylic polymer A and ethyl acetate as a polymerization solvent and reacting at 60°C for 4 hours under a nitrogen gas stream. ) was obtained.
  • To 100 parts of the solid content of the solution containing acrylic polymer A 0.05 part of isocyanate crosslinking agent C1 (trade name "Takenate D101E", manufactured by Mitsui Chemicals) and 1.5 parts of acrylic oligomer A were added.
  • a solvent-based adhesive composition S-1 was prepared by uniformly stirring and mixing the following components.
  • Adhesive composition S-2 0.05 isocyanate crosslinking agent (trade name "Takenate D101E", manufactured by Mitsui Chemicals, Inc.) per 100 parts solid content of the solution containing acrylic polymer A obtained in the preparation of adhesive composition S-1. 1 part, 1.5 parts of acrylic oligomer A, and 0.5 part of nonionic surfactant A1 (polyoxyethylene lauryl ether, trade name "Emulgen 104P", manufactured by Kao Corporation) and stirred uniformly. By mixing, a solvent-based adhesive composition S-2 was prepared.
  • Adhesive composition S-3 0.1 isocyanate-based crosslinking agent (trade name "Takenate D101E", manufactured by Mitsui Chemicals, Inc.) per 100 parts of solid content of the solution containing acrylic polymer A obtained in the preparation of adhesive composition S-1. 1.5 parts of acrylic oligomer A, and 0.5 part of nonionic surfactant A2 (glycerol monooleate, trade name "Rheodol MO-60", manufactured by Kao Corporation) were mixed uniformly. By stirring and mixing, a solvent-based adhesive composition S-3 was prepared.
  • Adhesive composition S-4 0.1 isocyanate-based crosslinking agent (trade name "Takenate D101E", manufactured by Mitsui Chemicals, Inc.) per 100 parts of solid content of the solution containing acrylic polymer A obtained in the preparation of adhesive composition S-1. part, 1.5 parts of acrylic oligomer A, and 0.3 part of nonionic surfactant A4 (polyoxyethylene alkyl ether, trade name "NAROACTY ID-60", manufactured by Sanyo Chemical Co., Ltd.). , and were uniformly stirred and mixed to prepare a solvent-type adhesive composition S-4.
  • solvent-type adhesive composition S-4 0.1 isocyanate-based crosslinking agent (trade name "Takenate D101E”, manufactured by Mitsui Chemicals, Inc.) per 100 parts of solid content of the solution containing acrylic polymer A obtained in the preparation of adhesive composition S-1. part, 1.5 parts of acrylic oligomer A, and 0.3 part of nonionic surfactant A4 (polyoxyethylene alkyl ether, trade
  • Adhesive composition S-5 0.5 parts of an isocyanate-based crosslinking agent (trade name "Takenate D101E”, manufactured by Mitsui Chemicals, Inc.) per 100 parts of solid content of the solution containing acrylic polymer A obtained in the preparation of adhesive composition S-1. 1.5 parts of acrylic oligomer A, and 0.5 part of nonionic surfactant A3 (polyoxyethylene polyoxypropylene alkyl ether, trade name "Emulgen MS-110", manufactured by Kao Corporation). The mixture was stirred and mixed uniformly to prepare a solvent-based adhesive composition S-5.
  • an isocyanate-based crosslinking agent trade name "Takenate D101E”, manufactured by Mitsui Chemicals, Inc.
  • nonionic surfactant A3 polyoxyethylene polyoxypropylene alkyl ether, trade name "Emulgen MS-110", manufactured by Kao Corporation.
  • Adhesive composition U-1 Lauryl acrylate (LA), 2-ethylhexyl acrylate (2EHA), N-vinyl-2-pyrrolidone (NVP), 4-hydroxybutyl acrylate (4HBA), photoinitiator A1 (trade name “Irgacure 184", Ciba Specialty Chemicals) (manufactured by Ciba Specialty Chemicals) and photopolymerization initiator A2 (trade name "Irgacure 651", manufactured by Ciba Specialty Chemicals) in a weight ratio of 60/22/10/8/0.1/0.1.
  • the monomer mixture was placed in a flask and photopolymerized by irradiating it with ultraviolet rays under a nitrogen atmosphere until the viscosity (BH viscometer, No. 5 rotor, 10 rpm, measurement temperature 30°C) reached approximately 15 Pa ⁇ s.
  • a monomer syrup containing a partially polymerized product was prepared.
  • Adhesive composition U-2 Lauryl acrylate (LA), 2-ethylhexyl acrylate (2EHA), N-vinyl-2-pyrrolidone (NVP), 4-hydroxybutyl acrylate (4HBA), photoinitiator A1 (trade name “Irgacure 184", Ciba Specialty Chemicals) (manufactured by Ciba Specialty Chemicals) and photopolymerization initiator A2 (trade name "Irgacure 651", manufactured by Ciba Specialty Chemicals) in a weight ratio of 36.4/60/2.5/1/0.05/0.05.
  • Aligninitiator A1 (trade name "Irgacure 184", Ciba Specialty Chemicals) (manufactured by Ciba Specialty Chemicals) and photopolymerization initiator A2 (trade name "Irgacure 651", manufactured by Ciba Specialty Chemicals) in a weight ratio of 38.5/60/2.5/8/0.05/0.05.
  • Adhesive composition S-6 In a reaction vessel equipped with a cooling tube, a nitrogen inlet tube, a thermometer, and a stirring device, 63 parts of 2-ethylhexyl acrylate (2EHA), 9 parts of methyl methacrylate (MMA), 13 parts of 2-hydroxyethyl acrylate (HEA), and N- 15 parts of vinyl-2-pyrrolidone (NVP) was added together with 0.2 parts of 2,2'-azobisisobutyronitrile (AIBN) as a thermal polymerization initiator and ethyl acetate as a polymerization solvent, and a nitrogen gas stream was added. By reacting at 60° C.
  • 2EHA 2-ethylhexyl acrylate
  • MMA methyl methacrylate
  • HOA 2-hydroxyethyl acrylate
  • NDP vinyl-2-pyrrolidone
  • AIBN 2,2'-azobisisobutyronitrile
  • Adhesive composition S-7 In a reaction vessel equipped with a cooling tube, a nitrogen inlet tube, a thermometer, and a stirring device, 72 parts of 2-ethylhexyl acrylate (2EHA), 1 part of methyl methacrylate (MMA), 13 parts of 2-hydroxyethyl acrylate (HEA), and N- 14 parts of vinyl-2-pyrrolidone (NVP), 0.2 parts of 2,2'-azobisisobutyronitrile (AIBN) as a thermal polymerization initiator, and 0.2 parts of ⁇ -thioglycerol (TGR) as a chain transfer agent.
  • 2EHA 2-ethylhexyl acrylate
  • MMA methyl methacrylate
  • HOA 2-hydroxyethyl acrylate
  • NDP vinyl-2-pyrrolidone
  • AIBN 2,2'-azobisisobutyronitrile
  • TGR ⁇ -thioglycerol
  • a solution containing acrylic polymer F with an Mw of 600,000 to 1,000,000 (solid content concentration 30%) was prepared by adding 12 parts of acrylic polymer F and ethyl acetate as a polymerization solvent and reacting at 60°C for 4 hours under a nitrogen gas stream. ) was obtained.
  • Adhesive composition E-1 49 parts of 2-ethylhexyl acrylate (2EHA), 49 parts of n-butyl methacrylate (BMA), 2 parts of acrylic acid (AA), and 2 parts of an anionic emulsifier (manufactured by Daiichi Kogyo Seiyaku Co., Ltd., Aqualon BC2020) as an emulsifier were subjected to ion exchange.
  • An aqueous emulsion (monomer emulsion) of the monomer mixture was prepared by mixing and emulsifying in 100 parts of water.
  • the above monomer emulsion was placed in a reaction vessel equipped with a cooling tube, a nitrogen introduction tube, a thermometer, and a stirring device, and stirred at room temperature for over 1 hour while introducing nitrogen gas.
  • the temperature of the system was raised to 60°C, and 2,2'-azobis[N-(2-carboxyethyl)-2-methylpropionamidine] hydrate (manufactured by Wako Pure Chemical Industries, Ltd., VA-057) was added as a polymerization initiator. ) and reacted at 60° C. for 6 hours to obtain an aqueous dispersion of acrylic polymer G.
  • Adhesive composition U-4 n-butyl methacrylate (BA), cyclohexyl acrylate (CHA), 4-hydroxybutyl acrylate (4HBA), photoinitiator A1 (product name "Irgacure 184", manufactured by Ciba Specialty Chemicals), and photoinitiator A2 (product name A mixture of Irgacure 651 (manufactured by Ciba Specialty Chemicals) in a weight ratio of 67/14/19/0.09/0.09 was put into a four-necked flask, and the viscosity (BH viscosity A monomer syrup containing a partial polymer of the monomer mixture was prepared by photopolymerizing the mixture by irradiating it with ultraviolet rays until the temperature reached approximately 15 Pa ⁇ s.
  • BH viscosity A monomer syrup containing a partial polymer of the monomer mixture was prepared by photopolymerizing the mixture by irradiating it with ultraviolet rays until the
  • DPHA dipentaerythritol hexaacrylate
  • HOA 2-hydroxyethyl acrylate
  • 4HBA 4-hydroxybutyl acrylate
  • acrylic oligomer A and acrylic oligomer B used in the preparation of the above adhesive composition were synthesized by the following method.
  • This acrylic oligomer A had a Tg of 67° C. and a Mw of 3,500.
  • This acrylic oligomer B had a Tg of 144° C. and a Mw of 4,300.
  • Adhesive composition S-1 was applied to a 38 ⁇ m thick release film R1 (Mitsubishi Plastics Co., Ltd., MRF#38) with one side of the polyester film serving as a release surface, and dried at 130°C for 5 minutes to reduce the thickness. An adhesive layer having a thickness of 25 ⁇ m was formed.
  • a pressure-sensitive adhesive sheet according to this example was obtained by laminating a corona-treated polyethylene terephthalate (PET) film with a thickness of 50 ⁇ m to the pressure-sensitive adhesive layer on the release film R1.
  • PET polyethylene terephthalate
  • Example 2 A pressure-sensitive adhesive sheet according to this example was obtained in the same manner as in Example 1 except that pressure-sensitive adhesive composition S-2 was used instead of pressure-sensitive adhesive composition S-1.
  • Example 3 A pressure-sensitive adhesive sheet according to this example was obtained in the same manner as in Example 1 except that pressure-sensitive adhesive composition S-3 was used instead of pressure-sensitive adhesive composition S-1.
  • Example 4 A pressure-sensitive adhesive sheet according to this example was obtained in the same manner as in Example 1 except that pressure-sensitive adhesive composition S-4 was used instead of pressure-sensitive adhesive composition S-1.
  • Example 5 A pressure-sensitive adhesive sheet according to this example was obtained in the same manner as in Example 1 except that pressure-sensitive adhesive composition S-5 was used instead of pressure-sensitive adhesive composition S-1.
  • Adhesive composition U-1 was applied to a 38 ⁇ m thick release film R1 (manufactured by Mitsubishi Plastics Co., Ltd., product name “MRF#38”), with one side of the polyester film being the release surface, and one side of the polyester film was released.
  • a 38 ⁇ m thick release film R2 manufactured by Mitsubishi Plastics Co., Ltd., product name “MRE #38”
  • the 25 ⁇ m thick adhesive is released. formed a layer.
  • the ultraviolet rays were irradiated using a black light lamp at an illuminance of 4 mW/cm 2 (measured with an industrial UV checker (manufactured by Topcon, trade name "UVR-T1") with a peak sensitivity wavelength of approximately 350 nm) for 180 seconds. I went there.
  • the release film R2 covering the adhesive layer was peeled off, and a corona-treated PET film having a thickness of 50 ⁇ m was bonded to the adhesive sheet, thereby obtaining an adhesive sheet according to this example.
  • Example 7 A pressure-sensitive adhesive sheet according to this example was obtained in the same manner as in Example 6, except that pressure-sensitive adhesive composition U-2 was used instead of pressure-sensitive adhesive composition U-1.
  • Example 8 A pressure-sensitive adhesive sheet according to this example was obtained in the same manner as in Example 6, except that pressure-sensitive adhesive composition U-3 was used instead of pressure-sensitive adhesive composition U-1.
  • Example 9 A pressure-sensitive adhesive sheet according to this example was obtained in the same manner as in Example 1 except that pressure-sensitive adhesive composition S-6 was used instead of pressure-sensitive adhesive composition S-1.
  • Example 10 A pressure-sensitive adhesive sheet according to this example was obtained in the same manner as in Example 1 except that pressure-sensitive adhesive composition S-7 was used instead of pressure-sensitive adhesive composition S-1.
  • Adhesive composition E-1 was applied to release film R1 (Mitsubishi Plastics Co., Ltd., MRF #38) and dried at 120° C. for 3 minutes to form an adhesive layer with a thickness of 25 ⁇ m.
  • a pressure-sensitive adhesive sheet according to this example was obtained by laminating a corona-treated polyethylene terephthalate (PET) film with a thickness of 50 ⁇ m to the pressure-sensitive adhesive layer on the release film R1.
  • PET polyethylene terephthalate
  • Example 12 A pressure-sensitive adhesive sheet according to this example was obtained in the same manner as in Example 6, except that pressure-sensitive adhesive composition U-4 was used instead of pressure-sensitive adhesive composition U-1.
  • the adhesive force N0 SUS to the stainless steel plate, the ethanol peeling force N1 SUS , and the adhesive force reduction distance R SUS were measured based on the measurement method described above. Further, for each example of the adhesive sheet, the adhesive force N0 GLA to the glass plate, the ethanol peeling force N1 GLA , and the adhesive force reduction distance R GLA were measured based on the measurement method described above. If the obtained adhesive strength reduction distance R SUS is 30 mm or more, the persistence of adhesive strength reduction (vs. SUS): G (good), and if the adhesive strength reduction distance R SUS is less than 30 mm, the adhesive strength is Force reduction durability (vs. SUS): Rated P (poor).
  • the adhesive sheets of Examples 1 to 8 have an ethanol peel force N1 SUS of 0.5 N/20 mm or less, an adhesive force N0 SUS of 3.0 N/20 mm or more, and a long-lasting adhesive force reduction ( SUS) was good.
  • the adhesive sheets of Examples 1 to 8 have an ethanol peeling force N1 GLA of 0.5 N/20 mm or less, an adhesive force N0 GLA of 3.0 N/20 mm or more, and a long-lasting adhesive force reduction (toward glass). ) were good. It has been confirmed that when the peeling method disclosed herein is applied to the pressure-sensitive adhesive sheets of Examples 1 to 8, it is possible to particularly suitably achieve both adhesion to the adherend and removability.
  • Adhesive sheet 20 Support 30 Release liner 50 Adhesive sheet with release liner

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JP2004149559A (ja) * 2002-10-28 2004-05-27 Nakagawa Chem:Kk 粘着シートの剥離方法、粘着シート剥離液含浸シート及びこれに用いる粘着シート剥離液適用装置
JP2005089640A (ja) * 2003-09-18 2005-04-07 Unon Giken:Kk 再剥離性粘着シート及び粘着シートの剥離方法
WO2020116497A1 (ja) * 2018-12-04 2020-06-11 積水化学工業株式会社 粘着テープの剥離方法、粘着テープ及び電子部品
JP2021095449A (ja) * 2019-12-13 2021-06-24 日東電工株式会社 粘着シート剥離方法

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KR102500919B1 (ko) 2018-02-05 2023-02-16 닛토덴코 가부시키가이샤 점착 시트 및 점착 시트 박리 방법
CN116018384B (zh) 2020-08-18 2025-08-12 日东电工株式会社 接合体的分离方法

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2004149559A (ja) * 2002-10-28 2004-05-27 Nakagawa Chem:Kk 粘着シートの剥離方法、粘着シート剥離液含浸シート及びこれに用いる粘着シート剥離液適用装置
JP2005089640A (ja) * 2003-09-18 2005-04-07 Unon Giken:Kk 再剥離性粘着シート及び粘着シートの剥離方法
WO2020116497A1 (ja) * 2018-12-04 2020-06-11 積水化学工業株式会社 粘着テープの剥離方法、粘着テープ及び電子部品
JP2021095449A (ja) * 2019-12-13 2021-06-24 日東電工株式会社 粘着シート剥離方法

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