TW201930521A - Adhesive sheet with mold release film and method for producing same - Google Patents

Abstract

This adhesive sheet (1) with a mold release film is provided with: a photocurable adhesive sheet (50) which has a first main surface and a second main surface; and a first mold release film (10) which is provisionally bonded to the first main surface of the adhesive sheet. The first mold release film comprises a mold release layer (15) on a film substrate (11); and the mold release layer (15) is in contact with the adhesive sheet (50). The adhesive sheet (50) contains a photocurable acrylic polymer and an ultraviolet absorbent. The mold release layer (15) is a silicone-based mold release layer, and has an Si atom content of 0.02-0.07 g/m2.

Description

Adhesive sheet with release film and manufacturing method thereof

The present invention relates to an adhesive sheet in which a release film is temporarily adhered and a method of producing the same.

In a display device such as a display device such as a liquid crystal display or an organic EL display (Organic Electroluminescence Display) or a touch panel, a transparent adhesive sheet is used for bonding the optical members. A transparent adhesive sheet is provided as an adhesive sheet of an attached film having a release film on both sides. In the use of the adhesive sheet, first, a release film (light release film) is peeled off to expose one surface of the adhesive sheet to bond with the first adherend, and another release film (heavy release film) Peeling, bonding the second adherend to the other side of the adhesive sheet.

An optical member used for a display device or an input device has a requirement that ultraviolet cutoff is required from the viewpoint of suppressing deterioration of components due to ultraviolet rays. For example, in the organic EL display, since deterioration due to ultraviolet rays of organic molecules constituting the light-emitting layer or the like greatly affects display characteristics, an ultraviolet cutoff property which is high on the optical member disposed on the front surface of the element is required. Further, in order to prevent deterioration of a polarizing element (for example, fading of iodine) caused by ultraviolet rays, a polarizing plate used for a liquid crystal display or an organic EL display requires ultraviolet cutoff for an optical member disposed on the front surface of the polarizing element.

As a method of providing an ultraviolet ray blocking property to an adhesive sheet, a method of adding an ultraviolet absorber to an adhesive composition is known. For example, Patent Document 1 discloses that an adhesive composition obtained by adding an ultraviolet absorber to a thermal polymerization type acrylic pressure-sensitive adhesive solution is applied in a film form, and then dried by heating to obtain ultraviolet cutoff properties. Adhesive sheet. Patent Document 2 describes that a photocurable acrylic pressure-sensitive adhesive composition containing a photocurable acrylic composition, a photopolymerization initiator, and an ultraviolet absorber is applied to a release film substrate in a layered manner. On the other hand, the other release film is placed on the surface to block the contact with the air, and photohardening is performed in this state to obtain a photocurable adhesive sheet having ultraviolet cutoff properties.
[Previous Technical Literature]
[Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2013-75978
[Patent Document 2] Japanese Patent Laid-Open Publication No. 2016-155981

[The problem that the invention wants to solve]

As described in Patent Document 2, when a photocurable adhesive is used, the formation of the adhesive sheet is not essential, and the thickness of the adhesive sheet is easily increased. Moreover, it has the advantage that photohardening is performed in a state in which the release sheet and the sheet-like photocurable adhesive composition are in contact with each other, whereby the smoothness of the adhesive sheet can be improved.

However, according to the study by the present inventors, it has been found that when the photocurable adhesive composition containing the ultraviolet absorber is irradiated with ultraviolet rays for photohardening, the release film and the photohardening of the light-irradiated surface are present. The peeling force of the adhesive sheet after the adhesion is greatly increased, and peeling of the release film becomes difficult when it is bonded to the adherend. In view of the related problems, an object of the present invention is to provide an adhesive sheet of an detachable film which has ultraviolet cutoff properties and is excellent in peeling property from a release film.
[Technical means to solve the problem]

The adhesive sheet of the release film of the present invention comprises a photocurable adhesive sheet having a first main surface and a second main surface, and a first release film temporarily adhered to the first main surface of the adhesive sheet. The first release film has a release layer on the film substrate, and the release layer is in contact with the adhesive sheet. The adhesive sheet contains a photocurable acrylic polymer and an ultraviolet absorber. The adhesive sheet attached to the release film may have a second release film temporarily adhered to the second main surface of the adhesive sheet.

The first main surface of the adhesive sheet is a light-irradiated surface when the photocurable adhesive composition is photocured. That is, the photo-curable adhesive sheet is formed by interposing the first release film and irradiating the photocurable adhesive composition with light. As the first release film attached to the light-irradiating surface side of the photocurable adhesive composition, a release film having a specific anthrone-separating layer is used, whereby the adhesive contains an ultraviolet absorber. In the case, excessive increase in peeling force can also be suppressed. The ketone ketone release layer of the first release film preferably has a Si atom content of 0.02 to 0.07 g/m ² .

The light transmittance of the adhesive sheet at a wavelength of 380 nm is preferably 10% or less. The adhesive sheet preferably contains 0.1 to 10 parts by weight of the ultraviolet absorber based on 100 parts by weight of the acrylic polymer. As the ultraviolet absorber, for example, a triterpenoid ultraviolet absorber can be used. The acrylic polymer of the adhesive sheet may contain, as a monomer component, a polyfunctional monomer component having two or more polymerizable functional groups in one molecule.

And attaching the first release film to the first main surface of the photocurable adhesive composition layer, and irradiating the photocurable adhesive composition with light through the first release film, thereby obtaining Adhesive sheet with release film. The photocurable adhesive composition contains an acrylic material, an ultraviolet absorber, and a photopolymerization initiator. Examples of the acrylic material contained in the photocurable adhesive composition include an acrylic monomer and a partial polymer thereof. The acrylic material may contain both an acrylic monomer and a partial polymer of an acrylic monomer.

In one embodiment, the laminate in which the photocurable adhesive composition layer is sandwiched between the first release film and the second release film is irradiated with light from the first release film side, and the photocurable adhesive is applied to the photo-curable adhesive. The composition was subjected to photohardening, whereby an adhesive sheet having a release film temporarily adhered to both sides was obtained. In the adhesive sheet on which the release film is temporarily adhered on both sides, the peeling force of the first release film and the adhesive sheet may be greater than the peeling force of the second release film and the adhesive sheet.
[Effects of the Invention]

An adhesive sheet having a high visible light transmittance and having an ultraviolet cutoff property can be preferably used as an optical adhesive sheet for a display device requiring ultraviolet cutoff or an input device for display. The adhesive sheet of the release film of the present invention is suppressed by the excessive rise of the peeling force of the adhesive sheet and the first release film, so the release film of the release film from the adhesive sheet and the adhesion of the adhesive sheet and the adherend It is excellent in workability.

The adhesive sheet of the release film of the present invention has a release film temporarily adhered to at least one side of the adhesive sheet. "Temporary adhesion" means a state in which it can be peeled off. In the adhesive sheet with the release film, the release film can be temporarily adhered to both sides of the adhesive sheet.

Fig. 1 is a cross-sectional view showing the adhesive sheet 1 with the release film of the release film 10, 20 temporarily adhered to both sides of the adhesive sheet 50. The adhesive sheet 50 is an adhesive which forms a sheet. The adhesive sheet 50 is transparent, and the absorption of visible light is small. The total light transmittance of the adhesive sheet 50 is preferably 85% or more, more preferably 90% or more. The haze of the adhesive sheet is preferably 2% or less, more preferably 1% or less. The total light transmittance and haze were measured using a haze meter based on JIS K7136.

The adhesive sheet 50 is an acrylic adhesive containing a photocurable acrylic polymer, and contains an ultraviolet absorber in addition to the acrylic polymer. The acrylic adhesive sheet contains a photocurable adhesive which comprises a part of a polymer (prepolymer) containing an acrylic monomer and/or an acrylic polymer, a UV absorber, and photopolymerization. The photocurable adhesive composition of the initiator is applied in a layer form and photohardened. In the present specification, the term "photocurable" refers to an adhesive which contains a photopolymerizable functional group such as a vinyl group or a (meth)acryl fluorenyl group and which is photocurable. "Photocured" adhesive refers to an adhesive which is photohardened to a photocurable adhesive. Further, in the case where the photocurable adhesive is polymerized in a part where the photopolymerizable compound is not reacted and remains, the adhesive is photocured and photocurable (photocurable) ) situation.

[Photocurable Adhesive Composition]
The photocurable adhesive composition contains a photopolymerizable acrylic material, an ultraviolet absorber, and a photopolymerization initiator.

<Photopolymerizable acrylic material>
Examples of the photopolymerizable acrylic material contained in the photocurable adhesive composition include an acrylic monomer and a partial polymer (prepolymer).

(monomer component)
As the acrylic monomer, an alkyl (meth)acrylate having an alkyl group having 1 to 20 carbon atoms can be preferably used. The alkyl group of the alkyl (meth)acrylate may have a branch. The content of the alkyl (meth)acrylate is preferably 40% by weight or more, more preferably 50% by weight or more, and still more preferably 60% by weight or more based on the total amount of the monomer components of the acrylic material.

The monomer component may contain a highly polar monomer such as a hydroxyl group-containing monomer or a nitrogen-containing monomer in addition to the alkyl (meth)acrylate. Since the acrylic polymer contains a highly polar monomer unit, there is a tendency that the cohesive force of the adhesive is improved, the adhesion of the adhesive sheet to the adherend is improved, and the white turbidity of the adhesive under high temperature and high humidity is suppressed, and adhesion is adhered. The transparency of the sheet is improved.

Examples of the hydroxyl group-containing monomer include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, and 6-hydroxyl (meth)acrylate. Hexyl ester, 8-hydroxyoctyl (meth)acrylate, 10-hydroxydecyl (meth)acrylate, 12-hydroxylauryl (meth)acrylate or (4-hydroxymethylcyclohexyl)-methyl acrylate . The content of the hydroxyl group-containing monomer is preferably from 1 to 40% by weight, more preferably from 3 to 30% by weight, still more preferably from 5 to 20% by weight, based on the total amount of the monomer components.

Examples of the nitrogen-containing monomer include N-vinylpyrrolidone, methylvinylpyrrolidone, vinylpyridine, vinylpiperidone, vinylpyrimidine, vinylpiperidin, vinylpyridinium, and ethylene. a vinyl monomer such as a pyrrole, a vinyl imidazole, a vinyl carbazole, a vinyl porphyrin, a (meth) propylene porphyrin, an N-vinyl carbamide, or an N-vinyl caprolactam, A cyanoacrylate monomer such as acrylonitrile or methacrylonitrile. The nitrogen-containing monomer is preferably one having a cyclic structure containing a nitrogen atom, and among them, an internal guanamine-based vinyl monomer such as N-vinylpyrrolidone is preferred. The content of the nitrogen-containing monomer is preferably from 0.5 to 50% by weight, more preferably from 1 to 40% by weight, still more preferably from 3 to 30% by weight, based on the total amount of the monomer components.

The monomer component may also contain a monomer other than the above, such as a carboxyl group-containing monomer, a cyclic ether group-containing monomer, and a decane-based monomer.

The monomer component may include a polyfunctional polymerizable compound having two or more polymerizable functional groups in one molecule. Examples of the polyfunctional polymerizable compound include a compound having two or more C=C bonds in one molecule, one C=C bond, an epoxy group, an aziridine group, an oxazoline group, an anthracenyl group, and a hydroxy group. A compound such as a polymerizable functional group. Among them, a polyfunctional polymerizable compound having two or more C=C bonds in one molecule is preferred. The polyfunctional polymerizable compound may be present as a monomer or oligomer in the adhesive composition, or may be bonded to a functional group such as a hydroxyl group of the prepolymer component.

Examples of the polyfunctional polymerizable compound having two or more C=C bonds in one molecule include (poly)ethylene glycol di(meth)acrylate, (poly)propylene glycol di(meth)acrylate, and neopentane. Diol di(meth)acrylate, pentaerythritol di(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol hexa(meth)acrylate, 1,2-ethanediol di(methyl) Acrylate, 1,6-hexanediol di(meth)acrylate, 1,12-dodecanediol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, tetrahydroxyl a polyfunctional acrylate such as methyl methane tri(meth)acrylate (an ester compound of a polyhydric alcohol and a (meth)acrylic acid); stearyl (meth)acrylate, vinyl (meth)acrylate, divinylbenzene, Epoxy acrylate, polyester acrylate, urethane acrylate, butyl di(meth) acrylate, hexyl (meth) acrylate, and the like. Among these, a polyfunctional acrylate, trimethylolpropane tri(meth)acrylate, hexanediol di(meth)acrylate, dipentaerythritol hexa(meth)acrylate, etc. are preferable. Functional monomers are preferably used.

The amount of the polyfunctional monomer to be used varies depending on the molecular weight, the number of functional groups, and the like, and is preferably 5% by weight or less, more preferably 3% by weight or less, even more preferably 2% by weight or less based on the total amount of the monomer components. . The amount of the polyfunctional monomer to be used may be 0.001 part by weight or more, 0.01 part by weight or more, or 0.05 part by weight or more based on the total amount of the monomer component.

In the photocurable adhesive composition, the above monomer component may be present as a partial polymer (prepolymer). The prepolymer is obtained by partially polymerizing a monomer component. By the presence of a monomer component as a prepolymer, the viscosity of the photocurable adhesive composition can be adjusted to a range suitable for application to a support substrate.

The prepolymer can be produced, for example, by partially polymerizing a composition for prepolymer formation obtained by mixing a monomer component and a polymerization initiator. The composition for forming a prepolymer may contain all the monomer components constituting the acrylic polymer, or may contain only a part of the monomers constituting the acrylic polymer. When the monomer component constituting the acrylic polymer contains a monofunctional monomer and a polyfunctional monomer, the polyfunctional monomer can be prepared by adding a polyfunctional monomer to the prepolymer composition obtained by partially polymerizing the monofunctional monomer. Adhesive composition. By adding a polyfunctional monomer to the prepolymer composition obtained by partially polymerizing the monofunctional monomer to carry out post polymerization, the crosslinking point of the polyfunctional monomer can be uniformly introduced into the polymer. The prepolymer-forming composition may contain a part of the polyfunctional monomer component constituting the acrylic polymer, and after the prepolymer is polymerized, the remaining polyfunctional monomer component may be added to carry out post-polymerization.

The prepolymer can be prepared by polymerization of 2 stages or more or 3 stages or more. For example, after prepolymerizing a monofunctional monomer, a polyfunctional monomer may be added and partially polymerized to prepare a prepolymer composition, and if necessary, a monomer component or the like may be further added to carry out post polymerization.

The polymerization method of the prepolymer is not particularly limited. From the viewpoint of adjusting the reaction time and setting the molecular weight (polymerization ratio) of the prepolymer to a desired range, photopolymerization by irradiation with active light such as ultraviolet rays is preferred. In the case of photopolymerization, it is preferred that the prepolymer composition comprises a photopolymerization initiator. Specific examples of the photopolymerization initiator are described later.

The composition for forming a prepolymer may contain a chain transfer agent or the like as needed in addition to the monomer component and the polymerization initiator. The chain transfer agent has the effect of receiving free radicals from the growing polymer chain to stop the elongation of the polymer, and the radical transfer agent that receives the free radicals attacks the monomer and begins the polymerization again. By using a chain transfer agent, it is possible to suppress an excessive increase in molecular weight without lowering the radical concentration in the reaction system. As the chain transfer agent, α-thioglycerol, lauryl mercaptan, glycidyl mercaptan, mercaptoacetic acid, 2-mercaptoethanol, thioglycolic acid, 2-ethylhexyl thioglycolate, 2 can be preferably used. Mercaptans such as 3-dimercapto-1-propanol.

The polymerization rate of the prepolymer is not particularly limited, and is preferably from 3 to 50%, more preferably from 5 to 40%, from the viewpoint of viscosity suitable for application to a substrate. The polymerization rate of the prepolymer can be adjusted to a desired range by adjusting the kind of the photopolymerization initiator, the amount of use, the irradiation intensity of the active light such as ultraviolet rays, the irradiation time, and the like. The polymerization rate was calculated from the following formula by the weight of the prepolymer composition before and after heating (drying) at 130 ° C for 3 hours. Further, in the case of partial polymerization by solution polymerization, the amount of the solvent is subtracted from the total weight of the prepolymer composition, and the weight is calculated as the pre-heating weight in the following formula.
Polymerization rate of polymer (%) = 100 × (weight after heating / weight before heating)

<Preparation of Photocurable Adhesive Composition>

A photocurable adhesive can be obtained by mixing the remaining monomer component, the ultraviolet absorber, the photopolymerization initiator, and other additives in the photopolymerizable acrylic material (monomer and/or a part thereof) combination.

<UV absorber>
Examples of the ultraviolet absorber include a benzotriazole-based ultraviolet absorber, a benzophenone-based ultraviolet absorber, a triterpenoid ultraviolet absorber, a salicylate-based ultraviolet absorber, and a cyanoacrylate-based ultraviolet absorber. . A triterpenoid ultraviolet absorber is preferred from the viewpoint of an ultraviolet-ray absorbing property, an acrylic-based adhesive sheet which is excellent in compatibility with an acrylic polymer, and which is easy to obtain high transparency. A triterpenoid ultraviolet absorber containing a hydroxyl group is particularly preferably a hydroxyphenyl triterpenoid ultraviolet absorber. The number of hydroxyl groups of the triterpenoid ultraviolet absorber is preferably 2 or less.

A commercially available product can be used as the ultraviolet absorber. As a commercial item of a triterpenoid ultraviolet absorber, 2-(4,6-bis(2,4-dimethylphenyl)-1,3,5-trian-2-yl)-5 is mentioned. Reaction product of -hydroxyphenyl group with [(alkoxy)methyl]oxirane ("TINUVIN 400" manufactured by BASF), 2-(2,4-dihydroxyphenyl)-4,6-bis- Reaction product of (2,4-dimethylphenyl)-1,3,5-triazine and (2-ethylhexyl)-glycidyl ester ("TINUVIN 405" by BASF), (2, 4 -Bis[2-hydroxy-4-butoxyphenyl]-6-(2,4-dibutoxyphenyl)-1,3,5-triazine ("TINUVIN 460" by BASF), 2- (4,6-Diphenyl-1,3,5-triazin-2-yl)-5-[(hexyl)oxy]-phenol ("TINUVIN 577" manufactured by BASF), 2-(2-hydroxy- 4-[1-octyloxycarbonylethoxy]phenyl)-4,6-bis(4-phenylphenyl)-1,3,5-triazine ("TINUVIN 479" manufactured by BASF).

The content of the ultraviolet absorber in the photocurable adhesive composition is preferably 0.1 to 10 parts by weight, more preferably 0.3 to 7 parts by weight, still more preferably 0.5 to 5 parts by weight, per 100 parts by weight of the monomer component. By setting the content of the ultraviolet absorber to the above range, it is possible to suppress a decrease in transparency due to bleeding of the ultraviolet absorber or the like, and to improve the ultraviolet cutoff property of the adhesive sheet. Moreover, when the content of the ultraviolet absorber is within the above range, the decrease in the polymerization rate of the adhesive composition can be suppressed.

<Photopolymerization initiator>
The photocurable adhesive composition contains a photopolymerization initiator. The photopolymerization initiator is a photo radical generating agent which generates a radical by visible light or ultraviolet light having a wavelength shorter than 450 nm.

When the ultraviolet curable agent is contained in the photocurable adhesive composition, a part of the irradiation light for photocuring is partially absorbed by the ultraviolet absorber. From the viewpoint of promoting the formation of radicals by the cleavage of the photopolymerization initiator and increasing the polymerization rate, it is preferred to use a photopolymerization initiator which is sensitive to a wavelength region where the absorption of the ultraviolet absorber is small. Specifically, the photopolymerization initiator is preferably one that is sensitive to a wavelength longer than 380 nm, and more preferably to a wavelength longer than 400 nm. It is preferred to use a photopolymerization initiator having a light absorption coefficient of 405 nm of 1 × 10 ² [mLg ^-1 cm ^-1 ] or more. The photopolymerization initiator having a long wavelength of light sensitivity may have sensitivity to light having a wavelength of 400 nm or less.

Specific examples of the photopolymerization initiator having a light sensitivity of 400 nm or more include 2,4,6-trimethylbenzimidyldiphenylphosphine oxide ("Lucirin TPO" manufactured by BASF), and 2 , 4,6-trimethylbenzimidyl ethoxyethoxyphosphine oxide ("Lucirin TPO-L" manufactured by BASF) and other fluorenylphosphine oxides; 2-benzyl-2-dimethylamino-1- Amino ketones such as (4-morpholinylphenyl)butanone-1 ("Irgacure 369" manufactured by BASF); bis(2,4,6-trimethylbenzylidene)-phenylphosphine oxide (BASF) "Irgacure 819"), 2,2-dimethoxy-1,2-diphenylethane-1-one ("Irgacure 651" manufactured by BASF), bis(2,6-dimethoxybenzate) A mercapto) bis-indenylphosphine oxide such as -2,4,4-trimethylpentylphosphine oxide ("CGI403" manufactured by BASF).

As a photopolymerization initiator, those having long-wavelength light sensitivity and those having no long-wavelength light sensitivity (for example, those having an absorption coefficient of 405 nm of less than 1 × 10 ² [mLg ^-1 cm ^-1 ]) can be used together. use.

Examples of the photopolymerization initiator which does not have a long-wavelength light sensitivity include a benzoin ether photopolymerization initiator, an acetophenone photopolymerization initiator, an α-keto alcohol photopolymerization initiator, and photoactivity. Lanthanide photopolymerization initiator, benzoin photopolymerization initiator, benzoin photopolymerization initiator, benzophenone photopolymerization initiator, ketal photopolymerization initiator, 9- Oxysulfuron A photopolymerization initiator, a mercaptophosphine oxide photopolymerization initiator, a titanocene photopolymerization initiator, and the like.

The content of the photopolymerization initiator in the photocurable adhesive composition is preferably 0.02 to 10 parts by weight, more preferably 0.02 to 10 parts by weight, based on 100 parts by total of the monomer component and the prepolymer component constituting the acrylic polymer. 0.05 to 5 parts by weight. There is a case where the polymerization rate becomes insufficient when the photopolymerization initiator is too small, and there are cases where the molecular weight of the polymer is low and the adhesion force of the adhesive becomes insufficient when the photopolymerization initiator is excessive.

As described above, a photopolymerization initiator can also be used in the preparation (partial polymerization) of the prepolymer. The photopolymerization initiator used for the partial polymerization may be the same as or different from the photopolymerization initiator added to the photocurable adhesive composition. When the composition for forming a prepolymer does not contain an ultraviolet absorber, and when a UV absorber is added after partial polymerization, the photopolymerization initiator for partial polymerization may not have a light sensitivity of a long wavelength. The unreacted material for the partially polymerized photopolymerization initiator can be directly used as a photopolymerization initiator in the photopolymerizable adhesive composition.

From the viewpoint of the utilization efficiency of the irradiation light, etc., it is preferred that the composition for forming a prepolymer does not contain an ultraviolet absorber, and an ultraviolet absorber is added to the prepolymer composition after partial polymerization. For example, it is preferred to use a photopolymerization initiator which does not have a long-wavelength light sensitivity as a polymerization initiator to carry out partial polymerization, and to add a photopolymerization having a long-wavelength light sensitivity to the partially polymerized composition. The initiator is used as a UV absorber and a post-addition polymerization initiator to prepare a photocurable pressure-sensitive adhesive composition, and the photocurable pressure-sensitive adhesive composition is applied to the substrate in a layered manner, followed by post-polymerization.

<Other ingredients>
A chain transfer agent may be included in the photocurable adhesive composition. The chain transfer agent contained in the photocurable adhesive composition is not particularly limited, and for example, the above chain transfer agent can be used. In the adhesive composition, a decane coupling agent, a crosslinking agent, an adhesion-imparting agent, a plasticizer, a softener, or the like may be contained in order to adjust the adhesion or the like. Further, the adhesive composition may contain an additive such as an anti-deterioration agent, a filler, a colorant, an antioxidant, a surfactant, an antistatic agent, etc., within a range not impairing the characteristics of the adhesive.

The photocurable adhesive composition preferably has a viscosity suitable for application to a substrate (for example, about 5 to 100 poise). The viscosity of the adhesive composition can be adjusted by, for example, addition of various polymers such as a tackifier, a polyfunctional monomer, or the like, a polymerization ratio of the prepolymer, and the like. The content of the acrylic monomer component (partial polymer of the acrylic monomer and the acrylic monomer) of the photocurable adhesive composition is preferably 50% by weight or more, more preferably 70% by weight or more, and still more preferably 80% by weight or more.

[Formation of Adhesive Sheet]
The above-mentioned photocurable adhesive composition is applied onto a support substrate and photocured to obtain an adhesive sheet. Examples of the method of applying the adhesive composition to a substrate include roll coating, contact roll coating, gravure coating, reverse coating, roll coating, spray coating, and dip roller coating. , bar coating, blade coating, air knife coating, curtain coating, lip coating, die coating. Since photoradical polymerization is inhibited by oxygen in the air, it is preferred to provide a cover sheet on the coating layer of the photocurable adhesive composition to block oxygen. The adhesive composition can be applied by sandwiching two sheets (support substrate and cover sheet) with the photocurable adhesive composition.

The coating thickness of the photocurable adhesive composition (thickness of the adhesive sheet 50) is not particularly limited, and is, for example, about 10 to 500 μm. The thickness of the adhesive sheet is preferably 50 μm or more, more preferably 100 μm or more, and still more preferably 150 μm or more from the viewpoint of improving the ultraviolet absorbing property of the adhesive sheet. The light transmittance of the adhesive sheet 50 at a wavelength of 380 nm is preferably 10% or less, more preferably 5% or less, still more preferably 3% or less.

The laminated body of the photocurable acrylic pressure-sensitive adhesive composition layer on the support substrate is irradiated with ultraviolet light and/or short-wavelength visible light to perform photocuring, whereby an adhesive sheet can be obtained. When the layered body in which the photocurable adhesive composition layer is sandwiched between the support substrate and the cover sheet is subjected to light irradiation to be photo-cured, the substrate side and the cover sheet side can be self-supported. Light irradiation is performed on either side, and light irradiation can be performed from both sides. As described in detail later, in the present invention, as the support substrate or the cover sheet attached to the light-irradiating surface side of the adhesive sheet, the release film 10 having the specific release layer 15 is used.

The light irradiation intensity is preferably 5 mW/cm ² or more from the viewpoint of increasing the curing speed. The light irradiation intensity is preferably 20 mW/cm ² or less from the viewpoint of sufficiently increasing the molecular weight of the acrylic polymer after photocuring and ensuring the holding power at high temperatures.

The integrated light amount of the irradiation light is preferably about 100 to 5,000 mJ/cm ² . The light source for light irradiation is not particularly limited as long as it emits light having a sensitivity in the wavelength range of the photopolymerization initiator contained in the adhesive composition, and an LED (Light Emitting Diode) can be preferably used. Light-emitting diodes) light sources, high-pressure mercury lamps, ultra-high pressure mercury lamps, metal halide lamps, xenon lamps, and the like.

Most of the ultraviolet light irradiated to the photocurable adhesive composition containing the ultraviolet absorber is absorbed by the ultraviolet absorber. From the viewpoint of suppressing the low molecular weight due to an increase in temperature, and improving the utilization efficiency and curing rate of the irradiation light, it is preferred to irradiate the light in the wavelength region where the light absorption of the ultraviolet absorber is small. From the viewpoint of less heat generation from the light source and illumination of light having a small wavelength width, it is preferred to use an LED light source. In the case of using an LED light source, the peak wavelength of the light emission is preferably 350 nm or more, more preferably 380 nm or more, and further preferably 400 nm or more.

The final polymerization rate of the monomer component in the adhesive sheet after photocuring is preferably 90% or more, more preferably 95% or more, still more preferably 98% or more. The gel fraction of the adhesive sheet is preferably 50% or more, more preferably 75% or more, and still more preferably 85% or more.

[release film]
The cover sheet for applying the adhesive composition and the cover sheet attached to the surface of the coating layer of the adhesive composition can be preferably used for the contact surface with the coating layer (adhesive sheet). Release film of the release layer. In the present invention, in a state in which a release film (first release film) 11 having a specific anthrone-based release layer 15 is provided on the light-irradiated surface side of the photocurable adhesive composition layer 55, Perform photohardening.

<Substrate>
As the base materials 11, 21 of the release films 10, 20, various resin films having transparency can be used. Examples of the resin material include polyester resins such as polyethylene terephthalate and polyethylene naphthalate, acetate resins, polyether oxime resins, polycarbonate resins, and polyamines. Resin, polyimide resin, polyolefin resin, (meth)acrylic resin, polyvinyl chloride resin, polyvinylidene chloride resin, polystyrene resin, polyvinyl alcohol resin, poly An aryl ester resin, a polyphenylene sulfide resin, or the like. Among these, a polyester resin such as polyethylene terephthalate is particularly preferred. The thickness of the substrate 11, 21 is preferably from 10 to 200 μm, more preferably from 25 to 150 μm.

<release layer>
Examples of the material of the release layer include an anthrone-based release agent, a fluorine-based release agent, a long-chain alkyl release agent, a fatty amide-based release agent, and cerium oxide powder. The release film 20 can be preferably used on the surface of the film substrate 21 to have an anthrone-based release agent, from the viewpoint of the adhesion to the acrylic adhesive sheet and the releasability. The fluorenone is a release layer 25 .

The release film 10 attached to the light-irradiated surface side of the photocurable adhesive composition layer 55 is provided with an anthrone-based release layer 15. The content of Si atoms per unit area of the anthrone-based release layer 15 is 0.02 to 0.07 g/m ² . The content of Si atoms in the anthrone-type release layer 15 is preferably from 0.025 to 0.06 g/m ² , more preferably from 0.03 to 0.055 g/m ² .

The fluorenone release layer 15 of the release film 10 contains a hardening fluorenone resin. The fluorenone-based resin may be a type which is mainly composed of itself, or may be a fluorenone which is obtained by graft polymerization or the like into a cationic ketone in an organic resin such as a polyurethane resin, an epoxy resin or an alkyd resin. Resin. As the fluorenone resin, an oxime resin of various types of hardening reaction such as addition molding, condensation type, ultraviolet curing type, electron beam curing type, and solventless type can be used. In particular, it is preferably used for hardening by an addition reaction using heat from the viewpoint of excellent adhesion to a film substrate and an appropriate adhesion to the acrylic adhesive sheet and peelability. An anthrone resin of the type which forms a peelable film is formed.

Examples of the anthrone-based material which is hardened by an addition reaction include a polyorganosiloxane having a vinyl group or an alkenyl group in the molecule. Examples of the alkenyl group include 3-butenyl group, 4-pentenyl group, 5-hexenyl group, 6-heptenyl group, 7-octenyl group, 8-decenyl group, and 9-nonenyl group. , 10-undecenyl, 11-dodecenyl and the like. Examples of the polyorganosiloxane include polyalkylalkyl siloxane such as polydimethyl siloxane, polydiethyl decane, and polymethyl ethyl siloxane; polyalkyl aryl oxime A copolymer obtained by using a plurality of monomer components containing Si atoms, such as poly(dimethyloxane-diethyloxane). Among these, polydimethyl siloxane is preferred.

As the fluorenone resin, a commercially available composition containing a curable anthrone resin can be used. As a commercial product of the sclerosing fluorenone-based release agent, KS-774, KS-775, KS-778, KS-779H, KS-847H, KS-856, and X-62- manufactured by Shin-Etsu Chemical Co., Ltd. 2422, and X-62-2461; YSR-3022, TPR-6700, TPR-6720, and TPR-6721 made of Toshiba ketone; LTC300B, LTC303E, LTC310, LTC314, SRX357 by Dow Corning Toray , BY24-749, SD7333, BY24-179, BY24-840, BY24-842, BY24-850, SP7015, SP7259, SD7220, SD7226, and SD7229; DKQ3-202, DKQ3-203 made by Dow Corning Asia , DKQ3-204, DKQ3-205, DKQ3-210, etc.

The curable anthrone-based release agent composition may contain an additive (peeling control agent) for the purpose of adjusting the release property of the release layer or the like. The addition-type anthrone-based release agent composition may comprise a hardening catalyst. As the hardening catalyst, a platinum-based catalyst is preferred. Examples of the platinum-based catalyst include chloroplatinic acid, an olefin complex of platinum, and an olefin complex of chloroplatinic acid. The amount of the platinum-based catalyst used is about 10 to 1000 ppm in terms of platinum relative to the total solid content of the anthrone-based release agent composition.

The anthrone ketone release agent composition may comprise an organic solvent. Examples of the organic solvent include hydrocarbon solvents such as cyclohexane, n-hexane, and n-heptane; aromatic solvents such as toluene and xylene; ester solvents such as ethyl acetate and methyl acetate; and acetone. A ketone solvent such as a ketyl ketone; an alcohol solvent such as methanol, ethanol or butanol. The organic solvent may also be a mixed solvent. The amount of the organic solvent used is preferably from about 80 to 99.9% by mass in the anthrone-based release agent composition.

The anthrone-based release agent composition may contain various additives such as a filler, an antistatic agent, an antioxidant, a plasticizer, and a colorant, as needed.

The anthrone-based release agent composition is applied onto the substrate 11 and dried by heating to form an anthrone-based release layer. Examples of the coating method include roll coating, contact roll coating, gravure coating, reverse coating, roll coating, spray coating, dip roller coating, bar coating, blade coating, and gas coating. Knife coating, curtain coating, lip coating, and die coating. As a heat drying method, hot air drying is mentioned. The conditions for hot air drying vary depending on the heat resistance of the substrate, and are usually carried out at about 80 to 150 ° C for about 10 seconds to 10 minutes. If necessary, in order to promote the addition reaction of an anthrone, the active energy ray such as heat treatment or ultraviolet irradiation may be used in combination.

The coating amount of the anthrone-based release agent composition may be adjusted so that the amount of the anthrone resin is from about 0.03 to 1 g/m ² . The thickness of the anthrone-based release layer 15 is, for example, 10 to 500 nm. The coating amount of the fluorenone-based release agent composition and the thickness of the fluorenone-based release layer 15 may be adjusted such that the Si atom content of the fluorenone-based release layer 15 is in the above range.

[Releasability of release film and adhesive sheet]
In the adhesive sheet on which the release film of the release film is temporarily adhered on both sides of the adhesive sheet, generally the peeling force of the adhesive sheet and the release film is peeled off from the adhesive film and the release film. The force is relatively small. When the adhesive sheet is used, the release film (light release film) having a low peeling force is peeled off from the adhesive sheet, and is bonded to the first adherend, and thereafter, the release force is relatively large. The film (heavy release film) was peeled off and bonded to the second adherend. By setting the difference in peeling force to the release film temporarily adhered to the front and back surfaces of the adhesive sheet, the light release film can be selectively peeled off when bonded to the first adherend, thereby improving the fit. Workability.

In the photohardenable adhesive sheet, the adhesive force of the adhesive is different before the photohardening, and therefore, the adhesive sheet of the light release film and the heavy release film are considered in consideration of the adhesive properties of the adhesive sheet after photohardening. The adhesion (peelability) is adjusted. In the case where the adhesive composition does not contain the ultraviolet absorber, the magnitude of the peeling force of the release film and the other release film does not change after the photohardening. On the other hand, when the ultraviolet curable adhesive is contained in the photocurable adhesive composition, there is a tendency that the peeling force of the first release film on the light irradiation surface side is increased as compared with the surface disposed on the opposite side. The increase in the peeling force of the two release film is remarkably large.

Therefore, in the adhesive sheet of the release film of the present invention, it is preferable that the first release film 10 of the light irradiation surface is a heavy release film and the second release film 20 of the opposite surface is a light release film. That is, it is preferable that the peeling force of the first release film 10 and the adhesive sheet 50 is greater than the peeling force of the second release film 20 and the adhesive sheet 50.

If the peeling force of the first release film 10 (heavy release film) and the adhesive sheet 50 is too large, the first release film 10 is self-adhesively attached to the first adhesive body in a state where the adhesive sheet 50 is attached to the first adherend. When the surface of the material 50 is peeled off, there are cases where defects such as deformation of the adhesive sheet and peeling of the adhesive sheet from the adherend are caused. The peeling force of the adhesive sheet 50 after photohardening and the first release film 10 is preferably 0.1 to 1.1 N/50 mm, more preferably 0.2 to 0.8 N/50 mm, still more preferably 0.3 to 0.7 N/50. Mm. The peeling force of the release film and the adhesive sheet was measured using a 180 peel test at a tensile speed of 0.3 m/min. In the present invention, by setting the Si atom content of the release layer 15 of the first release film 10 to the above range, excessive increase in the peeling force of the adhesive sheet and the first release film after photocuring can be suppressed.

When the ultraviolet absorbing agent is contained in the photocurable adhesive composition, the reason why the peeling force of the first release film is increased, and the Si content of the release layer can be adjusted to suppress the light curing of the adhesive composition. Although the reason for the excessive rise in the peeling force is uncertain, it is presumed that the unreacted thermally reactive functional group in the release layer is related to the reaction of the compound in the adhesive composition.

As described above, most of the ultraviolet light irradiated to the photocurable adhesive composition containing the ultraviolet absorber is absorbed by the ultraviolet absorber. That is, when the sensitivity wavelength of the photopolymerization initiator and the wavelength of the irradiation light are transferred to the long wavelength side (for example, 400 nm or more), it is difficult to completely suppress the light absorption of the ultraviolet absorber. When the ultraviolet absorber absorbs light, the light energy is converted into heat energy and the temperature rises. In particular, in the vicinity of the interface between the release layer 15 on the light-irradiating surface side and the adhesive composition layer 55, the light absorption amount of the ultraviolet absorber is large, and therefore, the temperature is liable to rise. When the temperature rises under light irradiation, in addition to the photohardening reaction, the thermosetting reaction also becomes easy to proceed. Therefore, it is considered that the unreacted thermally reactive functional group (vinyl, alkenyl, alkoxyalkyl, stanol, hydroalkyl, etc.) in the release layer 15 and the adhesive in the adhesive composition The compound in the composition reacts and the force (peeling force) increases.

The amount of unreacted thermally reactive functional groups in the release layer 15 is lowered by reducing the Si atom content per unit area of the anthrone-keel release layer 15. Therefore, it is considered that in the present invention, the amount of residual reactive functional groups in the release layer 15 which is reactive with the compound in the adhesive composition layer 15 is small, and the adhesive sheet 50 after photohardening can be suppressed. The peeling force of the release film 10 is excessively increased.

As described above, the light irradiation to the adhesive composition can be performed from either the support substrate side and the cover sheet side, or light irradiation can be performed from both sides. In the case of performing light irradiation from the support substrate side, the release film 10 having the above-described anthrone-keel release layer 15 may be used as the support substrate to which the adhesive composition is applied. In the case of performing light irradiation from the side of the cover sheet, the release film 10 having the above-described anthrone-keel release layer 15 may be used as the cover sheet attached to the adhesive composition layer 55.

In the case where light is irradiated from both sides, the above-mentioned release film may be used for either the support substrate or the cover sheet. The release film described above can be used for both the support substrate or the cover sheet. As described in Japanese Laid-Open Patent Publication No. 2014-65754, it is preferable to use the above-mentioned release film on the surface on which the light is first irradiated when the transfer direction is reversed and the bypass is conveyed and light is irradiated on both surfaces.

[Use of adhesive sheet]
Since the photocurable adhesive sheet has a high visible light transmittance and an ultraviolet cut-off property, it can be preferably used as a display device requiring ultraviolet cutoff and an optical adhesive for an input device for a display. Examples of the display device include a liquid crystal display device, an organic EL (electroluminescence) display device, a PDP (Plasma Display Panel), and electronic paper. As the input device, a touch panel can be cited. Further, the photocurable adhesive sheet may be used for bonding a display device to an input device, a bonding to a transparent plate disposed on a surface of a display device or an input device, or the like.

When the adhesive sheet of the release film having the release film is temporarily adhered to both sides, the light release film (second release film 20) is first peeled off, and the second main surface of the adhesive sheet 50 is exposed. A glued fit. Thereafter, the heavy release film (first release film 10) is peeled off, and the first main surface of the adhesive sheet 50 is exposed to bond with the second adherend. The release film on both sides may be peeled off and bonded to the adherend. When the adhesive sheet is photocurable, the adhesive sheet adhered to the adherend can be further irradiated with light. There is a case where the adhesion to the adherend sheet is light-hardened by bonding to the adherend, and the reliability with the adherend can be improved.
[Examples]

Hereinafter, the examples and comparative examples will be further described, but the present invention is not limited by the examples.

[Preparation of photocurable adhesive composition]
<Adhesive Composition A>
Containing 2-ethylhexyl acrylate (2EHA): 78 parts by weight, N-vinyl-2-pyrrolidone (NVP): 18 parts by weight, and 2-hydroxyethyl acrylate (HEA): 4 parts by weight 1-hydroxycyclohexyl phenyl ketone ("Irgacure 184" manufactured by BASF) was added to the monomer mixture: 0.035 parts by weight, and 2,2-dimethoxy-1,2-diphenylethane-1-one ( "Irgacure 651" manufactured by BASF): 0.035 parts by weight as a photopolymerization initiator (first addition of a photopolymerization initiator). The composition was irradiated with ultraviolet rays, and prepolymerized until the viscosity at room temperature was about 20 Pa·s to obtain a prepolymer having a polymerization ratio of about 8%.

Hexanediol diacrylate (HDDA) was added to 100 parts by weight of the prepolymer: 0.15 parts by weight, decane coupling agent ("KBM-403" manufactured by Shin-Etsu Chemical Co., Ltd.): 0.3 parts by weight, ultraviolet absorber (2,4-) Bis-[{4-(4-ethylhexyloxy)-4-hydroxy}-phenyl]-6-(4-methoxyphenyl)-1,3,5-triazine; BASF "Tinosorb" S") 15% by weight butyl acrylate (BA) solution: 4.7 parts by weight (UV absorber: 0.7 parts by weight), and added bis(2,4,6-trimethylbenzylidene)-phenyl oxide Phosphine ("Irgacure 819" manufactured by BASF): 0.15 parts by weight as a post-addition polymerization initiator to obtain an ultraviolet curable acrylic pressure-sensitive adhesive composition A.

<Adhesive Composition B>
The adhesive composition B was obtained in the same manner as in the preparation of the adhesive composition 1, except that the amount of the polymerization initiator added was changed from 0.15 part by weight to 0.1 part by weight.

<Adhesive Composition C>
In the preparation of the prepolymer composition, the composition of the monomer mixture was changed to 2EHA: 30.5 parts by weight, isostearyl acrylate (ISTA): 30.5 parts by weight, isobornyl acrylate (IBXA): 19 parts by weight, and 4-hydroxybutyl acrylate (4HBA): 20 parts by weight, the amount of the photopolymerization initiator added is 1-hydroxycyclohexyl phenyl ketone: 0.05 parts by weight, and 2,2-dimethoxy-1, 2-Diphenylethane-1-one: 0.05 parts by weight. The adhesive composition C was obtained in the same manner as the preparation of the adhesive composition 1, except for the above-mentioned change points.

[Preparation of an anthrone-based release agent solution]
<release agent solution A>
The addition of a hexenyl group to an anthrone (a polyorganosiloxane having a hexenyl group in the molecule, and a polyorganooxyalkylene crosslinking agent having a hydroquinone in the molecule; 30% toluene solution ("LTC761" manufactured by Dow Corning Toray): 30 parts by weight of an anthrone dispersion ("BY 24-850" manufactured by Dow Corning Toray): 0.9 parts by weight And a platinum catalyst for ketone hardening ("SRX 212" manufactured by Dow Corning Toray): 2 parts by weight diluted with a mixed solvent of toluene and hexane in a volume ratio of 1:1 as shown in Table 1. The release agent solution A is prepared at a specific concentration.

<release agent solution B>
10 parts by weight of a 30% toluene solution of a vinyl group-containing fluorenone ("KS-847T" manufactured by Shin-Etsu Chemical Co., Ltd.) and 1 part by weight of a platinum catalyst ("CAT-PL-50T" manufactured by Shin-Etsu Chemical Co., Ltd.) for curing fluorenone The release agent solution B was prepared by diluting to a specific concentration shown in Table 1 by a mixed solvent of toluene and hexane in a volume ratio of 1:1.

[Example 1]
<Production of substrate release film>
One side of a biaxially stretched polyester film ("Lumirror XD500P" manufactured by Toray Advanced Materials Korea) having a thickness of 75 μm was coated with a wire bar coater (#15) to form a solid of anthrone. The release agent solution B prepared in such a manner that the composition was 1.25 wt% was heated by a hot air dryer at 130 ° C for 1 minute to form a release layer.

<Production of Covering Release Film>
One side of a biaxially stretched polyester film ("Lumirror XD500P" manufactured by Toray Advanced Materials Korea) having a thickness of 75 μm was coated with a wire bar coater (#9). The release agent solution A prepared in such a manner that the composition was 0.7% by weight was heated by a hot air dryer at 130 ° C for 1 minute to form a release layer.

<Production of Adhesive Sheet Attached to Release Film>
The adhesive composition A was applied to the release layer forming surface of the coated substrate release film in a thickness of 150 μm to form a coating layer, and the release film was bonded to the surface of the coating layer to obtain a laminate. The laminate was subjected to ultraviolet irradiation under the conditions of an illuminance of 6.5 mW/cm ² and an integrated light amount of 1,500 mJ/cm ^{2 to} cover the release film, and the coating layer was photocured to obtain a photocurable adhesive layer. An adhesive sheet having a release film on both sides.

[Examples 2 to 6 and Comparative Examples 1 to 3]
The type and concentration of the release agent solution at the time of production of the release film, the wire rod diameter (model) of the bar coater, and the type of the adhesive composition were changed as shown in Table 1. A photocurable pressure-sensitive adhesive sheet having a release film on both surfaces was produced in the same manner as in Example 1 except for the above-described changes.

[Evaluation]
<Si atom content of the release layer>
The amount of Si atoms per unit area (mg/m ² ) was calculated by fluorescent X-ray analysis (XRF) covering the surface of the release layer of the release film. In the XRF analysis, a scanning-type fluorescent X-ray analyzer ("SSX100e" manufactured by Rigaku) equipped with a vertical xenon tube as an X-ray source was used, and the analysis area was 30 mmf, the analysis element was Si, the spectroscopic crystal was RX4, and the output was 50. The measurement was carried out under the conditions of kV and 70 mA.

<release force of release film>
The adhesive sheet of the release film was cut into a width of 50 mm, and subjected to a 180° peel test at a tensile speed of 0.3 m/min using a tensile tester under an environment of 23 ° C to peel off the substrate from the self-adhesive sheet. The peeling force of each of the film and the release film was measured.

[Evaluation results]
The evaluation results of the composition of the release layer (type of release agent solution, concentration of oxime, thickness, and amount of Si), the type of adhesive, and the peeling force of the release layer in the release film of the examples and the comparative examples are shown in Table 1.

[Table 1]

In any of Examples 1 to 6 and Comparative Examples 1 to 3, the peeling force of the release film of the substrate was about 0.2 N/50 mm, and no particular difference was observed. In Comparative Example 3 in which the same release agent was used for the release film of the substrate and the release film, the peeling force of the adhesive film after the light curing of the adhesive film was 10 times or more of the peeling force of the release film of the substrate. Peeling is more difficult. In Comparative Example 1 in which the type of the ketone release agent covering the release film and the composition of the adhesive were changed, as in Comparative Example 3, the peeling force covering the release film was also greatly increased. From these results, it is understood that when the layered body of the photocurable adhesive sheet containing the ultraviolet absorber is sandwiched between two release films, the light is cured by light irradiation, and the release sheet of the light-irradiated surface is obtained. The peeling force of the material becomes larger.

In Comparative Example 2 in which the concentration of the release agent solution and the coating thickness at the time of covering the release film were increased in Comparative Example 1, the amount of Si per unit area of the release layer became large, and the adhesive sheet was photohardened. The peeling force of the release film was made larger than that of Comparative Example 1.

In the first, fourth, and fifth embodiments in which the amount of Si per unit area is reduced by adjusting the concentration and coating thickness of the release agent solution at the time of covering the release film, the adhesive sheet is cured by photohardening. The peeling force of the film is reduced to less than 1 N/50 mm, and defects such as deformation of the adhesive sheet at the time of peeling are hard to occur. From the results of Examples 1, 4, and 5 and Comparative Examples 1 and 2, it is understood that the peeling force of the release film covered by the photo-hardened adhesive sheet is reduced by reducing the amount of Si per unit area of the release layer. .

In Example 2 and Example 3 in which the release film was covered and the composition of the adhesive was changed as in Example 1, the peeling force covering the release film was also the same as in Example 1. In Example 6 in which the same adhesive sheet as in Example 2 was used, the peeling property of the release film after photohardening of the adhesive sheet was also good.

From the above results, it is understood that the release sheet having the release layer having a specific atomic range of Si atom per unit area is provided by the photocurable adhesive sheet containing the ultraviolet absorber, thereby suppressing the release of the adhesive sheet after photohardening. The peeling force of the film is excessively increased.

1‧‧‧Adhesive sheet with release film

5‧‧‧Layer

10‧‧‧ release film

11‧‧‧Substrate

15‧‧‧ release layer

20‧‧‧ release film

21‧‧‧Substrate

25‧‧‧ release layer

50‧‧‧Adhesive sheets

55‧‧‧Photohardenable adhesive composition layer

Fig. 1 is a cross-sectional view showing a laminated structure of an adhesive sheet of an attached film.

Claims (9)

An adhesive sheet with a release film, comprising a photo-curing adhesive sheet having a first main surface and a second main surface, and a first release type temporarily adhered to the first main surface of the adhesive sheet In the film, the first release film has a release layer on the film substrate, and the release layer is in contact with the adhesive sheet, and the adhesive sheet comprises a photocurable acrylic polymer and an ultraviolet absorber. The release layer is an anthrone-based release layer having a Si atom content of 0.02 to 0.07 g/m ² . The adhesive sheet of the release film of claim 1, further comprising a second release film temporarily adhered to the second main surface of the adhesive sheet. The adhesive sheet of the release film of claim 2, wherein the peeling force of the first release film and the adhesive sheet is greater than the peeling force of the second release film and the adhesive sheet. The adhesive sheet of the release film according to any one of claims 1 to 3, wherein the adhesive sheet has a light transmittance of 10% or less at a wavelength of 380 nm. The adhesive sheet of the release film according to any one of claims 1 to 3, wherein the acrylic polymer contains, as a monomer component, a polyfunctional monomer component having two or more polymerizable functional groups in one molecule. The adhesive sheet of the release film according to any one of claims 1 to 3, wherein the ultraviolet absorber is a triterpenoid ultraviolet absorber. The adhesive sheet of the release film according to any one of claims 1 to 3, wherein the adhesive sheet contains 0.1 to 10 parts by weight of the ultraviolet absorber with respect to 100 parts by weight of the acrylic polymer. A method for manufacturing an adhesive sheet with a release film, comprising: a photocurable adhesive sheet having a first main surface and a second main surface; and a first adhesively bonded to the first main surface of the adhesive sheet a method for producing an adhesive film of a release film and a release film which is temporarily adhered to a second release film of the second main surface of the adhesive sheet, and comprising: a step of preparing a laminate, the laminate system A photocurable adhesive composition containing a part of a polymer containing an acrylic monomer and/or an acrylic monomer, an ultraviolet absorber, and a photopolymerization initiator between a release film and a second release film a layer and a step of photocuring the photocurable adhesive composition by irradiating light from the first release film side to the laminated body, wherein the first release film is on the film substrate and the photocurable adhesive The surface on the contact side of the composition is provided with a release layer, and the release layer is an anthrone-based release layer having a Si atom content of 0.02 to 0.07 g/m ² . The method for producing an adhesive sheet of the release film according to claim 8, wherein the photopolymerization initiator has sensitivity to a wavelength longer than 400 nm.