JP6326789B2 - Release film and adhesive film structure using the same - Google Patents

Description

  The present invention relates to a release film obtained by coating and curing a release agent composition, and further to an adhesive film structure using the release film.

  In recent years, in the display device field such as a touch panel, between members for improving visibility, for example, between a touch sensor and a front glass plate, is filled with resin to suppress light scattering and irregular reflection. With regard to the resin to be filled, after the ultraviolet curable resin composition is dispensed on one side of the member, the other base material is pasted together, and then the ultraviolet ray is irradiated and cured, but the unexposed part is reliably cured. It is difficult to control the accuracy of the bonding position. On the other hand, in order to avoid this problem, bonding a sheet-like film obtained by punching a pressure-sensitive adhesive film to an appropriate size on each member is becoming a mainstream technology in order to achieve both productivity improvement and bonding accuracy. is there.

  The pressure-sensitive adhesive is mainly applied to a release liner formed by coating and curing a silicone-based release material on a polyethylene terephthalate film (hereinafter referred to as PET film) having good optical properties, and applying it to an electron beam. What is made into a structure as a double-sided tape by curing with is the mainstream.

  The silicone release material is often used as a release liner by applying a polydimethylsiloxane derivative to a PET film, thermosetting with a platinum catalyst, and anchoring on the PET film. However, the wettability of the silicone release material on the surface of the PET film and the reactivity is so low that the main curing reaction requires aging, and the anchoring property to the PET film may be insufficient. Occasionally, the release material moves to the adhesive material interface, and after the adhesive material is attached to the adherend, a point-like peeling generally called a bubble occurs, and the visibility as a display device may be significantly impaired. It is a problem.

JP 2000-303018 A JP 2000-095929 A

As described above, in the field of display devices including a touch panel and precision electronic devices, the transfer of a release layer to the surface of a member used for them causes serious problems such as bubbles and peeling. Solving this problem by using a release film having low transferability while maintaining the release force is considered to be an effective technique.
An object of the present invention is to provide a release film having low transferability while maintaining a release force, and an adhesive film structure using the release film.

The present invention relates to a release film obtained by coating and curing a release agent composition, and further to a film structure using the release film.
The present invention relates to a release film having a substrate (also referred to as a substrate film) and a release layer formed on the surface of the substrate, wherein the release layer comprises (A) a silicone-modified polyester resin and (B) a nitrogen-containing material. The present invention relates to a release film obtained by curing a release agent composition containing an organic compound having an aromatic skeleton.
Moreover, this invention relates to the said peeling film whose organic compound which has a component (B) nitrogen-containing aromatic frame | skeleton is a reactive triazole derivative.
Moreover, this invention relates to the said peeling film whose peeling layer thickness is 100-3000 nm.
Moreover, this invention relates to the said peeling film in which a peeling layer structural component shows a different component ratio in a base-material interface, 5 nm in depth from an air surface, an air surface, and 10 nm in depth from an air surface.
Further, according to the present invention, the nitrogen / silicon element mass abundance ratio at the air surface, the depth from the air surface is 5 nm, the depth from the air surface is 10 nm, and the base material interface is 1 to 5% / 6 to 10%, 3 to 3, respectively. It is related with the said peeling film which is 7% / 1-6%, 3-6% / 0.5-5%, 3-10% / 0.5-5%.
Moreover, this invention relates to the said peeling film whose hardening method of a peeling layer is thermosetting.
Moreover, this invention relates to the said peeling film which is a peeling liner for adhesive films.
The present invention also relates to an adhesive film structure having an electron beam curable adhesive layer and the release film having the adhesive layer formed on the surface thereof.

According to the present invention, it is possible to provide a release film having a low transferability while maintaining a release force, and an adhesive film structure using the release film.
In the present invention, (A) a silicone-modified polyester resin is used as a main component, and (B) a compound having a nitrogen-containing aromatic skeleton is added thereto, whereby the silicone-derived skeleton component (A) that contributes to the peeling of the peeling layer is added to the air. (B) A compound having a nitrogen-containing aromatic skeleton that contributes to improving the adhesion to the substrate and the coating property to the substrate is localized in the release layer in the release layer, and then cured and configured. By maintaining the above, the base coatability of the release agent, the non-migration from the base film and the light peelability can be made compatible.
Thus, when used as a release liner for an adhesive film typified by OCA, the reliability of the adhesive layer related to peeling or bubbles from the touch panel constituent member is improved.

When the adhesive layer applied to a release film (also referred to as a release liner), commonly called a release liner, is soft and dull or exhibits high adhesive strength, It is necessary to make the peeling force very light.
A release film made by coating and curing an organopolysiloxane on a polyethylene terephthalate (PET) film used in the case of this case is a derivative containing polydimethylsiloxane as a main component in order to express its light release force. A technique of thermosetting with a catalyst such as platinum and fixing to a PET film substrate is used.
However, in order to satisfy the peeling force with respect to the adhesive layer, it is necessary to increase the concentration of the organopolysiloxane derivative and to cure and fix to the PET film over a long period of time at a low temperature. However, the migration of the adhesive layer of the release layer is still often a problem.

  Also, release agents for light release release liners often have poor coating properties on the substrate film, reducing the air surface release force of the release layer of the release liner and wetting the substrate surface. It has been difficult to achieve both compatibility and adhesion.

In view of the above-mentioned facts, the present inventors have devised the present invention to realize the base coatability of the release agent to the base film, the non-migration from the base film, and the light release of the adhesive layer.
That is, (A) a silicone-modified polyester resin as a main ingredient, and (B) a compound having a nitrogen-containing aromatic skeleton added to this, the silicone-derived skeleton component of (A) contributing to peeling of the peeling layer is added to the air surface. (B) A compound having a nitrogen-containing aromatic skeleton that contributes to improving the adhesion to the base material and the coating property to the base material is localized in the release layer on the base material surface, and then cured to form a structure. By maintaining the above, it is possible to achieve both the base coatability of the release agent and the non-migration and light release properties of the base film (hereinafter “in-layer localization” Write).

Among the components (A), an alkyd resin is used as the polyester resin, and an amino resin is used as the compound (B) having a nitrogen-containing aromatic skeleton. Japanese Patent Application Laid-Open No. 2000-303018 (Patent Document) It is known as a method described in 1) and JP 2000-095929 A (Patent Document 2).
However, in this method, it is difficult to reach the light release force of a general silicone release liner composed of an organopolysiloxane derivative, and the adhesive layer applied to the release film is soft and has no waist. In some cases or when high adhesive strength is exhibited, the peel strength of the adhesive layer is often heavy and insufficient.
This is still insufficient to localize the silicone-derived skeletal component of the release agent layer to the air surface and the component that contributes to improving the adhesion to the substrate and the coating property to the substrate to the substrate surface in the release layer. This is presumed to be due to this.

(B) Nitrogen-containing aromatic compounds containing nitrogen are effective in promoting the above-mentioned localization within the layer, but it goes without saying that this is due to the combination of (A) and (B).
In the method of the above-mentioned reference publication, an amino resin is taken up as the nitrogen-containing aromatic compound (B). Amino resins are used as curing components by acid-amino curing with alkyd resins.
The inventors of the present invention have intensively studied what is the method for further promoting localization in the release layer, and as a result, the combined use of methylated melamine resin and a benzotriazole derivative is effective for promoting the localization in the layer. I found it.
In particular, the addition of benzotriazole derivatives was confirmed to be a very effective technique for localization in the layer with a small amount of addition compared to other nitrogen-containing compounds such as polyisocyanates having a cyanurate ring, melamine, and benzoguanamine. .
From the viewpoint of the wettability of the release agent to a substrate such as a PET film, it was also confirmed that the wettability was further improved and the coatability was improved.

In the combined use of the methylated melamine resin and the triazole derivative, the triazole derivative is desirably reactive during the curing reaction. That is, when the triazole derivative exudes from the release layer of the release liner (bleed out) or the like, there is a concern that the adhesion of the release layer to the substrate may be lowered or the adhesive layer may be transferred.
As a result of studying compounds taking into account the reactivity in an acid-amino curing system, the present inventors have also confirmed that the allyl group-containing benzotriazole derivative exhibits the most excellent characteristics. This seems to be due to the strong formation of the localized structure in the layer by the reaction of the allyl group in the acid-amino curing system.

The X-ray photoelectron spectrometer (XPS) shows the element distribution in the release layer of the release liner formed by coating and curing a release agent composed of such a compound, etching from the air surface by argon plasma irradiation and the element composition ratio. As a result of analysis by X-ray photoelectron spectroscopy, it was detected that the carbon / silicon / nitrogen ratio in the vicinity of the air surface and the ratio of the inside of the layer and the substrate interface differed greatly as the inventors intended.
In particular, the difference in the elemental composition ratio from the air surface to 10 nm is large, and this is considered to explain that light peeling of the peeling force has been realized.

  The amino curing system using p-toluenesulfonic acid as the acid catalyst is most desirable to maximize the effect of using the methylated melamine resin and the allyl group-containing benzotriazole derivative in this method. This is because the reaction of the allyl group by acid and rapid curing (within 30 seconds of heating) are expected. When other nitrogen-containing aromatic compounds are used, curing is not completed immediately after coating drying, This is because, when the film is wound after coating and drying, it may be problematic that curing is required after drying in order to transfer to the back surface of the base material or to reduce it.

The use in which the release liner obtained in the present invention is most desired is a transparent elastomer pressure-sensitive adhesive film that is used for improving the visibility of touch panels and reducing the drop impact. This adhesive film is generally called an optically transparent adhesive film (hereinafter referred to as OCA: Optical Clear Adhesive). Of the properties required for the adhesive film, optical properties such as transparency relating to visibility, embedding property for embedding a frame and wiring, and reliability that does not cause peeling or bubbles during use are particularly important.
Among the above problems, the transparency and embedding can be improved by the resin composition, etc., but among the peeling and bubble problems, the cause is the transfer of the release component from the release liner to the adhesive layer Cannot be solved by improving the adhesive layer alone.
Furthermore, since the adhesive layer has been improved in the direction of softer and less elastic to improve embedding, the repelling force of the adhesive layer when peeling the release liner from the adhesive layer is small, and there is a problem that the release liner cannot be peeled off. It is increasing.

  The release property of the release liner can be reduced by reducing the surface energy with organopolysiloxane, but the adhesive force of the adhesive layer partially decreases due to the transfer of the release layer to the adhesive layer, which causes peeling and bubbles. It cannot be solved.

The present inventors applied a release liner prepared using the present technology as a base material, coated with an electron beam curable transparent adhesive layer, and then laminated a release liner using the present technology, which is a light release 3 The OCA structure was formed by preparing a film having a layer structure and performing electron beam curing thereon.
The release liner on the light release side was peeled off from the OCA film structure, laminated on the polarizing plate, and then the release liner on the heavy release side was peeled off and laminated on the stepped glass to prepare a sample for evaluation.
This was left under high temperature and high humidity, and the number of OCA peeling and bubbles was measured. Moreover, the adhesive force of OCA with each member (polarizing plate, glass) was also measured. As a result, no bubbles were generated and the adhesive force with each member was about 20% stronger than that of the conventional silicone release liner.
Further, silicon was detected in the vicinity of the bubble generation site, suggesting that the transfer of the release component of the silicone release liner to the adhesive layer reduced the reliability and the adhesive strength.
From this examination result, it was found that the release liner obtained in the present invention improves the reliability of an adhesive film such as OCA.

Hereinafter, embodiments of the present invention will be described in detail.
The release film of this embodiment is coated and cured with a release agent composition containing both (A) a silicone-modified polyester resin and (B) an organic compound having a nitrogen-containing aromatic skeleton on a substrate. This is a release film.

The (A) silicone-modified polyester resin in the present invention is preferably a resin obtained by modifying a polyester resin with a reactive silicone derivative. The polyester resin refers to a resin synthesized by a dehydration condensation reaction between a polybasic acid and a polyhydric alcohol.
The reactive silicone derivative may be a derivative that reacts with a carboxylic acid or alcohol at the end of the polyester resin such as a vinyl group or a glycidyl group, or has an active hydrogen such as an amino group or a hydroxyl group. It may react with a functional isocyanate or the like and can react with and modify the polyester.
Furthermore, the main chain of the silicone-modified component is preferably an organopolysiloxane, more preferably a polydimethylsiloxane skeleton or a polymethylphenylsiloxane skeleton, and the polydimethylsiloxane skeleton is used for light release and localization in the layer. Is optimal, but not limited thereto.
As the material used for the silicone modification, one-end-type modified polydimethylsiloxane or side-chain-type modified polydimethylsiloxane is suitable, for example, one-end-type epoxy-modified polydimethylsiloxane (trade name: X-22 manufactured by Shin-Etsu Silicone Co., Ltd.). -173DX, etc.), single-ended carbinol-modified polydimethylsiloxane (trade name: X-22-170DX, etc.), single-ended diol-modified polydimethylsiloxane (trade name: X-22-176DX, etc., manufactured by Shin-Etsu Silicone Co., Ltd.), single piece Terminal-type carboxyl-modified polydimethylsiloxane (trade name: X-22-3710 manufactured by Shin-Etsu Silicone Co., Ltd.), side-chain epoxy-modified polydimethylsiloxane (trade name: KF-1001 manufactured by Shin-Etsu Silicone Co., Ltd.), side-chain amine-modified Polydimethylsiloxane (trade name: Shin-Etsu Silico) KF-864, etc., manufactured by Co., Ltd.), side chain carbinol-modified polydimethylsiloxane (trade name: X-22-4015, manufactured by Shin-Etsu Silicone Co., Ltd.), side chain-type carboxyl-modified polydimethylsiloxane (trade name, Shin-Etsu Silicone Co., Ltd.) X-22-3701E, etc., manufactured by the company, and the like, but are not limited thereto.
The polydimethylsiloxane chain length of the silicone is preferably 1000 to 30000 as the number average molecular weight, and more preferably 3000 to 15000 as the number average molecular weight from the viewpoint of coexistence of modification efficiency and peeling force.

Examples of the compound (B) having a nitrogen-containing aromatic skeleton in the present invention include amino resins, melamine, benzoguanamine, triazole derivatives, and polyisocyanates having a cyanurate ring.
The amino resin refers to a resin obtained by condensing an amino group-containing aromatic compound with an aldehyde, and examples thereof include, but are not limited to, a methylated melamine resin and a butylated melamine resin. As the methylated melamine resin, Melan 523 manufactured by Hitachi Chemical Co., Ltd. is available, and as the butylated melamine resin, Melan 2000 manufactured by Hitachi Chemical Co., Ltd. is available.
Melamine is available from Nissan Chemical Co., Ltd., and benzoguanamine is available from Nippon Shokubai Co., Ltd.
As the triazole derivative, benzotriazole and its derivatives are preferable from the viewpoint of availability. Examples of the benzotriazole derivatives include 1- [N, N-bis (2-ethylhexyl) aminomethyl] -4-methylbenzotriazole and 1- [N, N-bis (2-ethylhexyl) aminomethyl] -5-methylbenzo. A mixture of triazoles (trade name: OA386 manufactured by Daiwa Kasei Co., Ltd.), 2- [2,4-hydroxyphenyl] -2H-benzotriazole (trade name: T-0 manufactured by Daiwa Kasei Co., Ltd.), 2- [2-hydroxy-4 -Octyloxyphenyl] -2H-benzotriazole (trade name, Daiwa Kasei Co., Ltd. T-7), 2- [4-benzoyloxy-2-hydroxyphenyl] -2H-benzotriazole (trade name, Daiwa Kasei Co., Ltd.) T-8), 2- [4-Ethoxy-2-hydroxyphenyl] -2H-benzotriazole (trade name: Large T-52), 2- [4-butoxy-2-hydroxyphenyl] -2H-benzotriazole (trade name T-53, manufactured by Daiwa Kasei Co., Ltd.), 2- [4-allyloxy-2-hydroxyphenyl] ] -2H-benzotriazole (trade name: T-84, manufactured by Daiwa Kasei Co., Ltd.) and the like, but are not limited to the above as long as the compound has a triazole skeleton.
As the polyisocyanate having a cyanurate ring, an isocyanurate type trimer of diisocyanate is desirable because of its availability. An isocyanurate-type trimer of hexamethylene diisocyanate (trade name: Duranate TPA-100 manufactured by Asahi Kasei Chemicals Co., Ltd., “Duranate” is a registered trademark) and the like are suitable, but are not limited thereto.
Of these nitrogen-containing compounds, from the viewpoint of rapid curability and peeling layer localization during coating, in combination with methylated melamine resins and allyl-modified benzotriazole derivatives, acid in the presence of an acid catalyst - amino curing It is most desirable to adjust.

  Moreover, the mixture of (B) the component whose compound is an amino resin among the organic compounds which have a nitrogen-containing aromatic skeleton, and (A) silicone modified polyester resin can be obtained from a market. As an example, the Tes Fine series manufactured by Hitachi Chemical Polymer Co., Ltd. and its peripheral products are suitable, and Tes Fine 319, TA31-300A, TA31-209E (“Tesfine” is a registered trademark) and the like can be used. The desired release film can be obtained by blending, coating and curing an organic compound having a nitrogen-containing aromatic skeleton other than amino resin in this product.

  The concept of the present invention is to localize the components in the release layer as described above in order to balance the peel force and the substrate adhesion force (non-migration). In order to achieve this, the thickness of the release layer to be applied is also important. The thickness of the release layer is preferably 100 to 3000 nm, and more preferably 200 to 1000 nm. When the release layer thickness is less than 100 nm, the adhesive strength of the release layer to the base film becomes smaller than the adhesive force of the adhesive, and when the release film is peeled off from the adhesive layer, the release layer is partially transferred to the adhesive layer. Problems may occur. In addition, when the thickness of the release layer is greater than 3000 nm, the balance between the localization within the layer and the curability may be lost, resulting in heavy release or peeling of the release layer from the substrate.

Verification of the intra-layer localization phenomenon was difficult because the thickness of the release layer was very thin. The inventors etched the release layer with argon plasma from the air surface of the release film, and successively tracked the element abundance ratio at the etching depth using XPS. The localization phenomenon was demonstrated.
In this measurement result, the element abundance ratio in the release layer has a high abundance ratio of silicon element on the air surface of the release layer and the lowest abundance ratio of nitrogen element, and the presence of silicon element at a depth of about 5 nm from the air surface. The ratio decreased rapidly and the abundance ratio of nitrogen element became the highest. Further, when the element abundance ratio was observed with respect to the depth direction, the abundance ratio of silicon element became almost constant and saturated in a portion deep from 10 nm from the air surface. The abundance ratio of nitrogen element also showed the abundance behavior similar to that of silicon element from a depth of 10 nm. Further observation of the depth direction showed that the nitrogen element abundance ratio increased again at the substrate interface.
This observed phenomenon is caused by localization of a component (a substance containing silicon element) that exhibits peelability within a range of several nm from the air surface due to localization within the layer, and promotes its localization at a depth of about 10 nm. It can be interpreted that the abundance ratio (nitrogen element ratio) of the compound having a nitrogen-containing aromatic skeleton is the highest abundance ratio in the layer as a result. In addition, the presence ratio of each element is only a few percent of the allyl-modified benzotriazole derivative, showing a large difference in the abundance ratio of the elements, indicating that this substance promotes localization in the layer. It is enough to make it easy to guess.

The element mass abundance ratio in this method is 5 nm deep from the air surface, air surface, 10 nm deep from the air surface, and nitrogen / silicon element mass abundance ratio at the substrate interface is nitrogen / silicon = 1-5% / 6-10%, nitrogen / silicon = 3-7% / 1-6% at a depth of 5 nm from the air surface, nitrogen / silicon = 3-6% / 0 at a depth of 10 nm from the air surface 0.5 to 5%, and nitrogen / silicon = 3 to 10% / 0.5 to 5% is preferable at the substrate interface.
When the nitrogen abundance ratio on the air surface is larger than 5% and / or when the silicon abundance ratio is smaller than 6%, the peeling force becomes heavy. If the nitrogen abundance ratio is less than 3% and / or the silicon element abundance ratio is greater than 6% at a depth of 5 nm from the air surface, the release layer may shift to the adhesive layer. If the nitrogen abundance ratio is less than 3% and / or the silicon abundance ratio is greater than 5% at a depth of 10 nm from the air surface, the release layer may shift to the adhesive layer. When the nitrogen abundance ratio is less than 3% and / or the silicon abundance ratio is more than 5% at the substrate interface, the peeling layer may fall off from the substrate surface or float.

  Various curing systems effective for the intra-layer localization are conceivable, but thermal curing is desirable for ease of manufacture and simultaneous reaction. In addition, in the reaction typified by urethane curing with a polyvalent isocyanate and the addition reaction expected to fix the vinyl group to the substrate, the curing reaction takes time, and therefore an acid-amino curing system using an acid catalyst is more desirable. As the acid catalyst, an acid catalyst generally used for acid-amino curing such as para-toluenesulfonic acid, sulfuric acid, hydrochloric acid and the like can be used. Paratoluenesulfonic acid is preferred because it is difficult for the catalyst to desorb and float from the release layer.

When the release film obtained in the present invention is used as a release liner, it is an adhesive double-sided tape that is most effective in terms of light release force and release component non-migration. Among these adhesive tapes, application to an optical member for a display represented by OCA is considered to be most effective in the industry.
The current mainstream OCA is a light release liner after applying a solvent-free acrylic syrup to a heavy release liner, which is composed of an acrylic resin as a main material and an electron beam curable oligomer or electron beam curable monomer. Is laminated and then irradiated with an electron beam to polymerize an acrylic syrup. The electron beam includes ultraviolet curing, and the current mainstream effect method is ultraviolet curing.
Although this acrylic syrup is solvent-free, the electron beam curable oligomers and monomers contained therein are more likely to penetrate into the release layer than the solvent in some cases, and may deteriorate the release layer. . This phenomenon is likely to occur with conventional silicone release liners, and the transfer of the release component to the OCA layer is likely to occur. The shift of the peeling component to OCA may cause peeling or bubble defects at the OCA interface with a member such as a polarizing plate, a touch sensor, or a cover glass after the touch panel is assembled.

  When the release liner obtained in the present invention is used in this field, defects such as peeling and bubbles are not detected, and the adhesion to various members is higher than when a general-purpose silicone release liner is used. It was. Further, OCA in the vicinity of the bubbles of the general-purpose silicone release liner was suctioned by a manipulator, and as a result of elemental analysis by X-ray, silicon element was detected from the OCA layer using the general-purpose silicone release liner. From the above fact, it can be easily considered that the transfer from the release layer of the general-purpose silicone release liner to the OCA layer has occurred.

  From the above facts, it was found that the OCA structure using the release liner obtained in the present invention has high reliability and high adhesion to various members. The present invention is considered to be particularly useful for improving the reliability in the above fields.

The release film of the present invention is useful as a release liner for adhesive films.
The pressure-sensitive adhesive film structure of the present invention (also referred to as a three-layer pressure-sensitive adhesive film) has an electron beam curable pressure-sensitive adhesive layer and the release film of the present invention on which the pressure-sensitive adhesive layer is formed. As a method for forming the adhesive layer, the adhesive layer may be applied to the release layer surface of the release film of the present invention and then cured by electron beam curing. Alternatively, the pressure-sensitive adhesive layer surface of the pressure-sensitive adhesive tape (film) may be pressure-bonded to the surface of the release layer of the release film of the present invention with a roller or the like to produce the pressure-sensitive adhesive film structure of the present invention.

EXAMPLES Hereinafter, although the suitable Example of this invention is described, this invention is not limited to these Examples. “%” Represents “% by mass”.
Example 1
Weigh 5 g of 2- [4-allyloxy-2-hydroxyphenyl] -2H-benzotriazole (hereinafter referred to as All-BTA; manufactured by Daiwa Kasei Co., Ltd .; trade name: Dainsorb T-84) into a 200 mL Erlenmeyer flask and add toluene. To 100 g, and a 5% All-BTA solution was prepared. 0.5g of 5% All-BTA solution was added to 9.95g (solid content 50%) of thermosetting release agent (trade name: TA31-300A, manufactured by Hitachi Chemical Co., Ltd.), and the release agent solution was sufficiently stirred. Obtained. After adding 4 g of toluene and 4 g of isopropanol to 2 g of this stripping solution, 0.05 g of 50% paratoluenesulfonic acid toluene solution (manufactured by Hitachi Chemical Co., Ltd .; trade name: dryer # 900) as a curing catalyst was added and stirred. The release agent solution for coating was obtained (All-BTA solid content ratio 0.5%).

  The obtained stripper solution was used as a bar coater no. 4 (manufactured by Daiichi Rika Co., Ltd.) and 100 μm thick transparent PET film (manufactured by Toray Industries, Inc .; trade name: Lumirror T60 # 100, “Lumirror” is a registered trademark), and immediately circulated dryer at 120 ° C. For 30 seconds, and immediately after that, it was placed in a circulation dryer at 150 ° C. for 30 seconds to dry the solvent and cure the release layer to obtain a release film.

(Peeling force)
The peel strength of the obtained release film was measured as the peel strength of the adhesive tape. That is, a polyester pressure-sensitive adhesive tape (manufactured by Nitto Denko Corporation; product name: No. 31B), which was subjected to one reciprocating press with a 2 kg roller, was left for 30 minutes and then cut into a strip with a substrate width of 25 mm. Then, a 180 ° peel test was performed at a speed of 300 mm / min using a tensile tester.

(Residual adhesion rate)
The residual adhesion rate of the obtained release film was measured. No. peeled off for measurement in the previous section. The 31B tape test piece was once again reciprocated to the stainless steel plate with a 2 kg roller and pulled at 180 ° at a speed of 300 mm / min as in the previous section, and the peel force W (N / 25 mm) was measured. On the other hand, no. Paste 31B tape to a stainless steel plate, which measures the force _W 0 required to peel from the stainless steel plate (N / 25 mm) under the same conditions, the ratio (W _{/ W} 0) of W to the _{W 0} (percentage ) Was determined as the residual adhesion rate.

(Adhesive layer peeling force)
A 250 μm PET film spacer is provided on both sides on a heavy release film (manufactured by Teijin DuPont Co., Ltd .; trade name: Purex A31, 125 μm thick, “Purex” is a registered trademark), and the above is obtained above. The composition was made so as to overlap the peeled film. Thereafter, a glass rod was placed in the upper back portion of the obtained release film, and it was folded back and prepared so as to wrap the glass rod. An ultraviolet curable acrylic pressure-sensitive adhesive (manufactured by Hitachi Chemical Co., Ltd .; trade name: Hitaroid 7924-7, “Hitaroid” is a registered trademark) is placed between the spacers in front of the folded portion to prevent bubbles from entering, and a glass rod Was moved in the forward direction through the release film to prepare a three-layer structure film of heavy release film / 250 μm adhesive layer / release film. This film was irradiated with an integrated light amount of 1500 mJ / cm ² from the side of the heavy release film with an ultraviolet irradiation device (metal halide lamp manufactured by GS Yuasa Co., Ltd.) to cure the adhesive layer.
The obtained three-layer structure adhesive film was cut into a width of 25 mm, and the release film was pulled at 90 ° at a speed of 300 mm / min using a tensile tester to measure the adhesive layer peeling force.

(Adhesive layer adhesive strength)
The three-layer structure adhesive film obtained above was cut to a width of 25 mm, the release film of the cut film was removed, and a 500 g roller was moved in one direction to the same size glass plate and pressure bonded. Thereafter, the heavy release film was removed, and an easy-adhesive PET film (made by Unitika Co., Ltd .: trade name; Emblet S38, “Embret” is a registered trademark) cut into a width of 25 mm was moved and pressure-bonded by moving a 500 g roller in one direction. It was. Thereafter, the easy-adhesive film was sandwiched between chucks, and pulled at 180 ° at a speed of 300 mm / min, and the adhesive strength of the adhesive layer was measured.

(Reliability evaluation)
The three-layer structure adhesive film obtained above was cut into 8 × 11 mm, the release film of the cut film was removed, and a 500 g roller was moved in one direction on the same size glass plate and pressure bonded. After that, the heavy release film is removed, and a glass plate of the same size or a glass plate with a frame (width 3 mm step 35 μm) is pasted on it with a laminating device (device name LAMIN Model No. MP94 manufactured by Taiwan Thingming Co., Ltd.) A three-layer structure was created.
This structure was allowed to stand at 65 ° C. and 90% RH for 1000 hours, and the state of peeling or bubbles was confirmed.

(Element ratio)
The element abundance ratio of the release film obtained above was measured using XPS (scanning X-ray photoelectron spectrometer AXIS-165 type manufactured by Shimadzu / Kratos). This measurement result was used as the element abundance ratio of the air surface, and an argon gun was used on this surface, and etching was sequentially performed from the air surface toward the inner surface of the release layer at a constant speed at an acceleration voltage of 3.5 kV and a current value of 20 mA. The element abundance ratio in the depth direction was measured. The base material (PET) interface data is obtained by sequentially performing argon etching to obtain the element abundance data, and the data before the acquired data becomes the same as the element abundance ratio of the untreated PET. It was.

(Example 2)
Similarly to Example 1, 1.0 g of 5% All-BTA solution was sufficiently added to 9.90 g (solid content 50%) of a thermosetting release agent (manufactured by Hitachi Chemical Polymer Co., Ltd .; trade name: TA31-300A). The mixture was stirred to obtain a release agent solution. After adding 4 g of toluene and 4 g of isopropanol to 2 g of this stripping solution, 0.05 g of 50% paratoluenesulfonic acid toluene solution (manufactured by Hitachi Chemical Co., Ltd .; trade name: dryer # 900) as a curing catalyst was added and stirred. A release agent solution for coating was obtained (All-BTA solid content ratio 1%).

  The obtained stripper solution was used as a bar coater no. 4 (manufactured by Daiichi Rika Co., Ltd.) and coated on a 100 μm-thick transparent PET film (manufactured by Toray Industries, Inc .; trade name: Lumirror T60 # 100), immediately put into a circulating dryer at 120 ° C. for 30 seconds, and immediately thereafter The film was put in a circulation dryer at 150 ° C. for 30 seconds to dry the solvent and harden the release layer to obtain a release film. The properties of this release film were obtained according to Example 1.

(Example 3)
As in Example 1, 2.0 g of 5% All-BTA solution was sufficiently added to 9.80 g (solid content 50%) of thermosetting release agent (manufactured by Hitachi Chemical Polymer Co., Ltd .; trade name: TA31-300A). Stirring to obtain a release agent solution. After adding 4 g of toluene and 4 g of isopropanol to 2 g of this stripping solution, 0.05 g of 50% paratoluenesulfonic acid toluene solution (manufactured by Hitachi Chemical Co., Ltd .; trade name: dryer # 900) as a curing catalyst was added and stirred. The release agent solution for coating was obtained (All-BTA solid content ratio 2%).

  The obtained stripper solution was used as a bar coater no. 4 (manufactured by Daiichi Rika Co., Ltd.) and coated on a 100 μm-thick transparent PET film (manufactured by Toray Industries, Inc .; trade name: Lumirror T60 # 100), immediately put into a circulating dryer at 120 ° C. for 30 seconds, and immediately thereafter The film was put in a circulation dryer at 150 ° C. for 30 seconds to dry the solvent and harden the release layer to obtain a release film. The properties of this release film were obtained according to Example 1.

Example 4
As in Example 1, 3.0 g of 5% All-BTA solution was sufficiently added to 9.70 g (solid content 50%) of thermosetting release agent (manufactured by Hitachi Chemical Polymer Co., Ltd .; trade name: TA31-300A). The mixture was stirred to obtain a release agent solution. After adding 4 g of toluene and 4 g of isopropanol to 2 g of this stripping solution, 0.05 g of 50% paratoluenesulfonic acid toluene solution (manufactured by Hitachi Chemical Co., Ltd .; trade name: dryer # 900) as a curing catalyst was added and stirred. The release agent solution for coating was obtained (All-BTA solid content ratio 3%).

  The obtained stripper solution was used as a bar coater no. 4 (manufactured by Daiichi Rika Co., Ltd.) and coated on a 100 μm-thick transparent PET film (manufactured by Toray Industries, Inc .; trade name: Lumirror T60 # 100), immediately put into a circulating dryer at 120 ° C. for 30 seconds, and immediately thereafter The film was put in a circulation dryer at 150 ° C. for 30 seconds to dry the solvent and harden the release layer to obtain a release film. The properties of this release film were obtained according to Example 1.

(Example 5)
Similarly to Example 1, 0.5 g of 5% All-BTA solution was sufficiently added to 9.95 g (solid content 50%) of a thermosetting release agent (manufactured by Hitachi Chemical Polymer Co., Ltd .; trade name: TA31-209E). The mixture was stirred to obtain a release agent solution. After adding 4 g of toluene and 4 g of isopropanol to 2 g of this stripping solution, 0.05 g of 50% paratoluenesulfonic acid toluene solution (manufactured by Hitachi Chemical Co., Ltd .; trade name: dryer # 900) as a curing catalyst was added and stirred. The release agent solution for coating was obtained (All-BTA solid content ratio 0.5%).

  The obtained stripper solution was used as a bar coater no. 4 (manufactured by Daiichi Rika Co., Ltd.) and coated on a 100 μm-thick transparent PET film (manufactured by Toray Industries, Inc .; trade name: Lumirror T60 # 100), immediately put into a circulating dryer at 120 ° C. for 30 seconds, and immediately thereafter The film was put in a circulation dryer at 150 ° C. for 30 seconds to dry the solvent and harden the release layer to obtain a release film. The properties of this release film were obtained according to Example 1.

(Example 6)
Similarly to Example 1, 1.0 g of 5% All-BTA solution was sufficiently added to 9.90 g (solid content 50%) of thermosetting release agent (manufactured by Hitachi Chemical Polymer Co., Ltd .; trade name: TA31-209E). Stirring to obtain a release agent solution. After adding and stirring 4 g of toluene and 4 g of isopropanol to 2 g of this peeling solution, 0.05 g of 50% paratoluenesulfonic acid toluene solution (manufactured by Hitachi Chemical Co., Ltd .; trade name: dryer # 900) as a curing catalyst was added and stirred. A release agent solution for coating was obtained (All-BTA solid content ratio 1%).

  The obtained stripper solution was used as a bar coater no. 4 (manufactured by Daiichi Rika Co., Ltd.) 100 μm thick transparent PET film (manufactured by Toray Industries, Inc .; trade name: Lumirror T60 # 100), immediately put into a 120 ° C. circulation dryer for 30 seconds, and then immediately 150 The film was put in a circulation dryer at 0 ° C. for 30 seconds to dry the solvent and harden the release layer to obtain a release film. The properties of this release film were obtained according to Example 1.

(Example 7)
Similarly to Example 1, 2.0 g of 5% All-BTA solution was sufficiently added to 9.80 g (solid content 50%) of a thermosetting release agent (manufactured by Hitachi Chemical Polymer Co., Ltd .; trade name: TA31-209E). Stirring to obtain a release agent solution. After adding 4 g of toluene and 4 g of isopropanol to 2 g of this stripping solution, 0.05 g of 50% paratoluenesulfonic acid toluene solution (manufactured by Hitachi Chemical Co., Ltd .; trade name: dryer # 900) as a curing catalyst was added and stirred. The release agent solution for coating was obtained (All-BTA solid content ratio 2%).

  The obtained stripper solution was used as a bar coater no. 4 (manufactured by Daiichi Rika Co., Ltd.) and coated on a 100 μm-thick transparent PET film (manufactured by Toray Industries, Inc .; trade name: Lumirror T60 # 100), immediately put into a circulating dryer at 120 ° C. for 30 seconds, and immediately thereafter The film was put in a circulation dryer at 150 ° C. for 30 seconds to dry the solvent and harden the release layer to obtain a release film. The properties of this release film were obtained according to Example 1.

(Example 8)
As in Example 1, 3.0 g of 5% All-BTA solution was sufficiently added to 9.70 g (solid content 50%) of a thermosetting release agent (manufactured by Hitachi Chemical Co., Ltd .; trade name: TA31-209E). The mixture was stirred to obtain a release agent solution. After adding 4 g of toluene and 4 g of isopropanol to 2 g of this stripping solution, 0.05 g of 50% paratoluenesulfonic acid toluene solution (manufactured by Hitachi Chemical Co., Ltd .; trade name: dryer # 900) as a curing catalyst was added and stirred. The release agent solution for coating was obtained (All-BTA solid content ratio 3%).

  The obtained stripper solution was used as a bar coater no. 4 (manufactured by Daiichi Rika Co., Ltd.) and coated on a 100 μm-thick transparent PET film (manufactured by Toray Industries, Inc .; trade name: Lumirror T60 # 100), immediately put into a circulating dryer at 120 ° C. for 30 seconds, and immediately thereafter The film was put in a circulation dryer at 150 ° C. for 30 seconds to dry the solvent and harden the release layer to obtain a release film. The properties of this release film were obtained according to Example 1.

(Comparative Example 1)
4 g of toluene and 4 g of isopropanol were added to 2 g (solid content 50%) of thermosetting release agent (manufactured by Hitachi Chemical Polymer Co., Ltd .; trade name: TA31-300A), and stirred, and then a 50% paratoluenesulfonic acid toluene solution as a curing catalyst. 0.05 g (trade name: dryer # 900, manufactured by Hitachi Chemical Polymer Co., Ltd.) was added and stirred to obtain a release agent solution for coating.

  The obtained stripper solution was used as a bar coater no. 4 (manufactured by Daiichi Rika Co., Ltd.) and coated on a 100 μm-thick transparent PET film (manufactured by Toray Industries, Inc .; trade name: Lumirror T60 # 100), immediately put into a circulating dryer at 120 ° C. for 30 seconds, and immediately thereafter The film was put in a circulation dryer at 150 ° C. for 30 seconds to dry the solvent and harden the release layer to obtain a release film. The properties of this release film were obtained according to Example 1.

(Comparative Example 2)
4g of toluene and 4g of isopropanol were added to 2g (solid content 50%) of thermosetting release agent (manufactured by Hitachi Chemical Co., Ltd .; trade name: TA31-209E), and stirred, and then 50% paratoluenesulfonic acid toluene solution as a curing catalyst. 0.05 g (trade name: dryer # 900, manufactured by Hitachi Chemical Polymer Co., Ltd.) was added and stirred to obtain a release agent solution for coating.

  The obtained stripper solution was used as a bar coater no. 4 (manufactured by Daiichi Rika Co., Ltd.) and coated on a 100 μm-thick transparent PET film (manufactured by Toray Industries, Inc .; trade name: Lumirror T60 # 100), immediately put into a circulating dryer at 120 ° C. for 30 seconds, and immediately thereafter The film was put in a circulation dryer at 150 ° C. for 30 seconds to dry the solvent and harden the release layer to obtain a release film. The properties of this release film were obtained according to Example 1.

(Comparative Example 3)
The characteristics of a commercially available silicone release film (manufactured by Fujimori Kogyo Co., Ltd .; trade name: film binder BD-50) were obtained according to Example 1.

(Comparative Example 4)
The characteristics of a commercially available silicone release film (manufactured by Nippa Corporation; trade name: PET100X1-KX8) were obtained according to Example 1.

  The evaluation results of Examples 1 to 8 and Comparative Examples 1 to 4 are shown in Table 1.

  Examples 1-8 compared with Comparative Examples 1-4, while realizing light peeling of peeling force, a residual adhesive force hardly changes, and with respect to the glass of the three-layer structure adhesive film produced in the present Example The adhesive strength was improved by 20-30%. Further, the reliability of peeling and bubbles was improved in Examples 1 to 8 as compared with Comparative Examples 3 to 4, and it can be said that the effectiveness of the present invention was proved.

  In Examples 1 to 4, compared with Comparative Example 1, the localization in the layer has progressed from the result of XPS, and the improvement in characteristics was recognized as shown in Table 1, so that the present invention was added. It is considered that an organic compound having a nitrogen-containing aromatic skeleton, especially a reactive triazole derivative, exhibited an effect.

Claims (7)

In a release film having a substrate and a release layer formed on the substrate surface, the release layer contains (A) a silicone-modified polyester resin and (B) an organic compound having a nitrogen-containing aromatic skeleton. der those obtained by curing a release agent composition comprising is,
The release film in which the organic compound having the component (B) nitrogen-containing aromatic skeleton contains a reactive triazole derivative and an amino resin . The release film according to claim 1, wherein the release layer has a thickness of 100 to 3000 nm. The release film according to claim 1 or 2 , wherein the release layer constituent components have different component ratios at an air surface, a depth of 5 nm from the air surface, a depth of 10 nm from the air surface, and a substrate interface. The nitrogen / silicon element mass abundance ratios at the air surface, the depth from the air surface to 5 nm, the depth from the air surface to 10 nm, and the substrate interface are 1 to 5% / 6 to 10% and 3 to 7% / 1 to 6, respectively. release film% 3-6% / 0.5% to 5%, according to claim 3, wherein from 3 to 10% / 0.5% to 5%. The release film according to any one of claims 1-4 cure method of the release layer is a thermosetting. It is a release liner for adhesive films, The release film in any one of Claims 1-5 . An adhesive film structure comprising an electron beam curable adhesive layer and the release film according to any one of claims 1 to 5 , wherein the adhesive layer is formed on a surface.