Release film, film laminate, and method for producing same

Abstract

The invention relates to a release film, a film laminate, and methods for producing the same. A novel release film, which has excellent light peelability that is easy to peel from a silicone adhesive layer and can further reduce the amount of fluorinated silicone used, is characterized in that: the release film is provided with a release layer on at least one surface of a base film; the mold release layer is formed by curing a mold release layer composition containing (A) a curable silicone having a fluorine substituent, (B) a curable silicone not containing a fluorine substituent, and (D) a curing catalyst, and fluorine atoms are unevenly distributed on the surface of the mold release layer in the concentration distribution of the fluorine atoms in the thickness direction in the mold release layer.

Description

[0001] This application is a divisional application of the Chinese Patent Application No. 202080041368.6, filed on April 14, 2020, entitled “Release Film, Film Laminated Body, Method for Manufacturing the Same, and Method for Using the Same”. TECHNICAL FIELD

[0002] The present application relates to a release film, a film laminated body using the same, a method for manufacturing the same, and a method for using the same. BACKGROUND

[0003] In recent years, the number of vehicles equipped with liquid crystal panels has increased. In such vehicle-mounted applications, there are many cases where the panel components are exposed to high temperatures and low temperatures for a long time, and the adhesives that bond the panel components are required to have high weather resistance and heat resistance. As adhesives that meet these requirements, silicone adhesives, which use silicone as the main component, have attracted attention.

[0004] Silicone adhesives have excellent heat resistance, chemical resistance, and transparency, and exhibit adhesive force to silicone rubber, fluororesin, metal, and the like, which are difficult to bond with general adhesives, and have excellent re-adhesion properties.

[0005] Silicone adhesives are used in the form of a tape (film) formed by a release film as the adhesive layer. Before use, the silicone adhesives are usually stored with one or both sides covered with a release film, and the release film is usually peeled off and used at the time of use.

[0006] As a release film used in such applications, a silicone release film in which a silicone release agent is applied to a base film is often used.

[0007] However, in the case of a silicone release film, when a silicone adhesive is covered with the release film, the release agent and the adhesive have similar chemical structures, and thus there is a tendency for the adhesive and the release film to be strongly bonded and become difficult to peel off. Therefore, in order to reduce the peel force value (light peelability) of the silicone adhesive, operations such as the introduction of fluorine into the silicone release agent are performed. For example, in order to exhibit peelability from a silicone adhesive, a fluorinated silicone material having a fluorine substituent is proposed in Patent Literature 1.

[0008] Prior Art Documents

[0009] Patent Literature

[0010] Patent Literature 1: Japanese Patent Application Publication No. 2011-201035 SUMMARY

[0011] Problems to be Solved by the Invention

[0012] The fluorine-substituted organosilicon (also referred to as "fluorinated organosilicon") disclosed in Patent Document 1 is high in chemical stability and is a substance low in toxicity. However, since the fluorinated organosilicon is expensive, it is required to reduce the amount of the fluorinated organosilicon. In addition, the release film coated with the fluorinated organosilicon release agent is difficult to be recycled, and thus it is also desired to reduce the amount of the fluorinated organosilicon from this point of view. In addition, the durability of the release layer is sometimes a problem.

[0013] Therefore, regarding the organosilicon release film formed with the fluorinated organosilicon, the present application provides a novel release film which has a slight release property with respect to the organosilicon adhesive layer and is also capable of reducing the amount of the fluorinated organosilicon, and a film laminate using the release film. In addition, a novel release film which can improve the durability of the release layer, and a film laminate using the release film are provided.

[0014] Solution to the problem

[0015] As a first release film having a release layer formed by curing a release layer composition containing (A) a curable organosilicon having a fluorine-substituting group, (B) a curable organosilicon not containing a fluorine-substituting group, and (D) a curing catalyst on at least one side of a base film, the present application proposes a release film characterized in that, in a concentration distribution of fluorine atoms in the thickness direction within the release layer, the fluorine atoms are biased toward the surface of the release layer, and the fluorine atom concentration at the surface of the release layer is 39.0 atomic concentration % or more.

[0016] As a second release film having a release layer formed by curing a release layer composition containing (A) a curable organosilicon having a fluorine-substituting group, (B) a curable organosilicon not containing a fluorine-substituting group, and (D) a curing catalyst on at least one side of a base film, the present application also proposes a release film characterized in that, using GC-IB (gas cluster ion beam) in XPS (X-ray photoelectron spectroscopy), a concentration distribution of fluorine atoms in the thickness direction within the aforementioned release layer is measured at a constant sputtering rate, the obtained fluorine atom concentration distribution (vertical axis: fluorine atom concentration (atomic %), horizontal axis: sputtering time (minutes)) is divided into nine equal parts with respect to the total sputtering time, and when the first measurement point (sputtering time 0), the second measurement point,... the tenth measurement point are determined,

[0017] The fluorine atom concentration (atomic %) in the second measurement point to the tenth measurement point is 80.0% or less of the fluorine atom concentration (atomic %) in the first measurement point (sputtering time 0), that is, when the fluorine atom concentration (atomic %) in the first measurement point (sputtering time 0) is taken as 100.0%, it is 80.0% or less thereof.

[0018] As a third release film having a release layer formed by curing a release layer composition containing (A) a curable organosilicon having a fluorine substituent, (B) a curable organosilicon not containing a fluorine substituent, and (D) a curing catalyst on at least one side of a base film, the present application also proposes a release film characterized in that, using GC-IB (gas cluster ion beam), the concentration distribution of fluorine atoms in the thickness direction of the aforementioned release layer is measured at a constant sputtering rate, the obtained fluorine atom concentration distribution (vertical axis: fluorine atom concentration (atom%), horizontal axis: sputtering time (minutes)) is divided into nine equal parts with respect to the total sputtering time, and the average fluorine atom concentration (atom%) in the 6th measurement point to the 10th measurement point is higher than the fluorine atom concentration (atom%) in the 1st measurement point (sputtering time 0) by 2.2%, that is, when the fluorine atom concentration (atom%) in the 1st measurement point (sputtering time 0) is taken as 100.0%, higher than this by 2.2%.

[0019] The average fluorine atom concentration (atom%) in the 6th measurement point to the 10th measurement point is higher than the fluorine atom concentration (atom%) in the 1st measurement point (sputtering time 0) by 2.2%, that is, when the fluorine atom concentration (atom%) in the 1st measurement point (sputtering time 0) is taken as 100.0%, higher than this by 2.2%.

[0020] The present application also proposes a method for producing a release film characterized in that, after mixing (A) a curable organosilicon having a fluorine substituent, (C) an organosilicon crosslinking agent, and (D) a curing catalyst, stirring and / or standing are performed (in the present application, this treatment is also referred to as "pre-treatment"), and then, mixing with (B) a curable organosilicon not having a fluorine substituent is performed, a release layer composition is prepared, and this release layer composition is applied to at least one side of a base film.

[0021] Effects of the Invention

[0022] For the 1st release film and the 2nd release film proposed by the present application, with respect to the release layer formed using a fluorinated organosilicon, by causing the fluorine to be biased to the surface of the release layer, the release layer has a slight peeling property with respect to the organosilicon adhesive layer, and the amount of fluorinated organosilicon can also be reduced.

[0023] In addition, for the 3rd release film proposed by the present application, with respect to the release layer formed using a fluorinated organosilicon, by causing the fluorine to exist inside the release layer, the durability of the release layer can be improved.

[0024] In addition, according to the method for producing a release film proposed by the present application, a release film such as this can be suitably produced. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1A graph showing atomic concentration distribution of carbon (C), oxygen (0), silicon (Si), and fluorine (F) (vertical axis: atomic concentration (atom %), horizontal axis: sputtering time (minute)) as measurement data of XPS (X-ray photoelectron spectroscopy) obtained in Example 1.

[0026] Figure 2 A graph showing atomic concentration distribution of carbon (C), oxygen (0), silicon (Si), and fluorine (F) (vertical axis: atomic concentration (atom %), horizontal axis: sputtering time (minute)) as measurement data of XPS (X-ray photoelectron spectroscopy) obtained in Example 2.

[0027] Figure 3 A graph showing atomic concentration distribution of carbon (C), oxygen (0), silicon (Si), and fluorine (F) (vertical axis: atomic concentration (atom %), horizontal axis: sputtering time (minute)) as measurement data of XPS (X-ray photoelectron spectroscopy) obtained in Example 5.

[0028] Figure 4 A graph showing atomic concentration distribution of carbon (C), oxygen (0), silicon (Si), and fluorine (F) (vertical axis: atomic concentration (atom %), horizontal axis: sputtering time (minute)) as measurement data of XPS (X-ray photoelectron spectroscopy) obtained in Comparative Example 1.

[0029] Figure 5 A graph showing atomic concentration distribution of carbon (C), oxygen (0), silicon (Si), and fluorine (F) (vertical axis: atomic concentration (atom %), horizontal axis: sputtering time (minute)) as measurement data of XPS (X-ray photoelectron spectroscopy) obtained in Comparative Example 2.

[0030] Figure 6 A graph showing atomic concentration distribution of carbon (C), oxygen (0), silicon (Si), and fluorine (F) (vertical axis: atomic concentration (atom %), horizontal axis: sputtering time (minute)) as measurement data of XPS (X-ray photoelectron spectroscopy) obtained in Comparative Example 3. DETAILED DESCRIPTION

[0031] Next, the present application is described based on the embodiment examples. However, the present application is not limited to the following described embodiments.

[0032] <<The Release Film>>

[0033] The release film (referred to as "the present release film") of one example of the embodiment of the present application is provided with a release layer (referred to as "the present release layer") of a release layer composition (referred to as "the present release layer composition") containing (A) a curable silicone having a fluorine substituent (also referred to as "fluorinated curable silicone"), (B) a curable silicone not containing a fluorine substituent (also referred to as "non-fluorinated curable silicone"), and (D) a curing catalyst, and, as necessary, (C) a silicone crosslinking agent, cured on one side or both sides of a base film (referred to as "the present base film").

[0034] <The present release layer>

[0035] The present release layer is a layer of the present release layer composition cured, and preferably, in the concentration distribution of fluorine atoms in the thickness direction within the release layer, fluorine is biased toward the surface of the release layer.

[0036] By thus biasing fluorine toward the surface of the release layer, excellent easy peeling property of the silicone adhesive layer can be achieved, and the amount of fluorinated silicone can be reduced.

[0037] For the present release layer, the concentration distribution (ratio) of fluorine (F) atoms in the thickness direction within the release layer is measured as an object under constant sputtering speed using GC-IB (gas cluster ion beam) by XPS (X-ray photoelectron spectroscopy), and the obtained fluorine atom concentration distribution (vertical axis: fluorine atom concentration (atom%), horizontal axis: sputtering time (minutes)) is divided into nine equal parts with respect to the total sputtering time, and the fluorine atom concentration (atom%, also referred to as atom concentration %) at the 1st measurement point (sputtering time 0), i.e., the surface of the release layer is 39.0% or more, further preferably 39.5% or more, and more preferably 40.0% or more. On the other hand, the upper limit is not limited, but is usually 60.0% or less, and more preferably 50.0% or less.

[0038] In addition, for the present release layer, when the fluorine atom concentration (atom%) at the 1st measurement point (sputtering time 0) is set to 100.0%, the fluorine atom concentration (atom%) at the 2nd measurement point to the 10th measurement point is preferably 80.0% or less thereof, further preferably 70.0% or less thereof, more preferably 60.0% or less thereof, and more preferably 40.0% or less thereof, and particularly preferably 30% or less thereof. The lower limit is not particularly limited, but is usually higher than 2.2%, and preferably 3.0% or more, more preferably 4.0% or more, and more preferably 5.0% or more.

[0039] Here, the sputtering time is correlated with the depth from the surface of the present release layer, and thus the aforementioned sputtering time can be replaced by an index of the depth from the surface of the present release layer.

[0040] In the present release layer, when fluorine is made to be concentrated on the surface of the release layer as described above, it is preferable, for example, to perform "preprocessing" as described later to prepare the present release layer composition. However, the method is not limited to this.

[0041] Further, when the concentration of fluorine atoms (atomic %) in the 1st measurement point (sputtering time 0) is taken as 100.0%, the average concentration of fluorine atoms (atomic %) in the 6th to 10th measurement points is preferably higher than 2.2%, further preferably 3.0% or more, 4.0% or more, 5.0% or more. However, if the viewpoint of making fluorine more concentrated on the surface of the release layer is taken into account, it is preferable that it be 30.0% or less, further preferably 20.0% or less, 10.0% or less.

[0042] By performing "preprocessing" as described later, fluorine is also more distributed in the interior of the present release layer (close to the substrate) compared to the case where preprocessing is not performed. The detailed mechanism is not clear, but it is presumed that fluorine originating from intermediates (crosslinking agents alone or in combination with fluorinated organosilicon resins, but not in a state where crosslinking reactions of fluorinated organosilicon resins with each other have been completed) and by-products as reaction products based on "preprocessing" is distributed.

[0043] When fluorine is thus made to be concentrated on the surface of the release layer and the interior of the present release layer also contains fluorine to some extent, it is preferable to more sufficiently perform "preprocessing" as described later. However, the method is not limited to this.

[0044] Note that, as described above, the sputtering time is related to the depth from the surface of the release layer, and therefore, the depth from the surface of the release layer can be used instead of the sputtering time described above to calculate the ratios described above. At this time, in the measurement of the concentration of fluorine atoms (atomic %), in the case where the film thickness fluctuation and the like at the time of preparing the measurement sample do not exactly divide the 9 intervals from the surface of the release layer to the base layer, i.e., the substrate film, the 9 intervals are recalculated using other parameters, and the concentration of fluorine atoms (atomic %) from the 1st to 10th measurement points can be calculated.

[0045] With respect to the content of fluorine atoms in the present release layer, it is preferable that it be 500 mass ppm or more, further preferably 1000 mass ppm or more, 3000 mass ppm or more, from the viewpoint that a stable and preferable easy release can be obtained with respect to the organosilicon adhesive. On the other hand, it is preferable that it be 800000 mass ppm or less, further preferably 700000 mass ppm or less, 500000 mass ppm or less, 300000 mass ppm or less, from the viewpoint of reducing the amount of fluorinated organosilicon and reducing the content of fluorine atoms.

[0046] <Release layer composition>

[0047] The present release layer composition is a composition comprising (A) a curable silicone having a fluorine substituent, (B) a curable silicone not containing a fluorine substituent, and (D) a curing catalyst, and, as necessary, (C) a silicone crosslinking agent.

[0048] ((A) Curable silicone having a fluorine substituent)

[0049] The curable silicone having a fluorine substituent can impart stable easy peelability to the silicone adhesive.

[0050] Note that "silicone" means a polymer in which a siloxane bond (≡Si-O-Si≡) formed of silicon and oxygen is a skeleton, and an organic group mainly comprising a methyl group (-CH3) is bonded to the silicon (Si).

[0051] "Curable silicone" means a silicone that can be cured by undergoing a crosslinking reaction through heating or light irradiation (ultraviolet rays).

[0052] The aforementioned "fluorine substituent" means a substituent containing a fluorine atom.

[0053] The substituent containing a fluorine atom (fluorine substituent) is not particularly limited as long as it contains a fluorine atom in the substituent. Specifically, a fluorine group, a trifluoromethyl group, a pentafluoroethyl group, a 2,2-trifluoroethyl group, a 1H, 1H-heptafluorobutyl group, a 2H-hexafluoroisopropyl group, a perfluoro-t-butyl group, a perfluoro-hexyl group, and the like can be given. However, the present application is not limited to these.

[0054] In addition, as the component having a fluorine substituent, a resin containing a fluorine substituent in a side chain portion of a resin skeleton can be given.

[0055] As specific examples of the curable silicone having a fluorine substituent, KP-911, X-70-201S, X-41-3035 manufactured by Shin-Etsu Chemical Co., Ltd., FS1265-300CS, FS1265-1000CS, FS1265-10000CS, BY24-900, BY24-903, 3062, Q2-7785, SYL-OFF 7792, SYL-OFF 7795, and the like manufactured by Dow Corning Toray Co., Ltd. can be given. However, the present application is not limited to these.

[0056] The curable silicone having a fluorine substituent can be solvent type, non-solvent type, or a mixture thereof.

[0057] The curable silicone having a fluorine substituent can be used alone or in a mixture of two or more.

[0058] Here, "solventless type curable silicone" means silicone that can be applied even without dilution with a solvent, and is a relatively low molecular weight silicone formed of a short polysiloxane chain.

[0059] The viscosity of the solventless type curable silicone is preferably 1000 mPa-s or less alone, and further preferably 50 mPa-s or more or 900 mPa-s or less, 80 mPa-s or more or 800 mPa-s or less. This is also true for (B) curable silicone not containing a fluorine-substituted group.

[0060] On the other hand, "solvent type curable silicone" means silicone having a viscosity as high as to be unable to be applied without dilution with a solvent, and is a relatively high molecular weight silicone. This is also true for (B) curable silicone not containing a fluorine-substituted group.

[0061] For the viscosity of the solvent type curable silicone, the viscosity when a 30% toluene solution is prepared is preferably 1000 mPa-s or more, and further preferably 2000 mPa-s or more or 20000 mPa-s or less, 3000 mPa-s or more or 18000 mPa-s or less. The solvent type curable silicone has a tendency to have improved adhesion to a base film by having a high viscosity. This is also true for (B) curable silicone not containing a fluorine-substituted group.

[0062] The fluorine atom content (atomic number fraction) of the curable silicone having a fluorine-substituted group is usually several thousand ppm (less than 1% of the total atomic number in the "curable silicone having a fluorine-substituted group") to several ten thousand ppm (several tens % of the total atomic number in the "curable silicone having a fluorine-substituted group").

[0063] ((B) curable silicone not containing a fluorine-substituted group)

[0064] The curable silicone not containing a fluorine-substituted group can be either solvent type or solventless type, or a mixture thereof. From the viewpoint of stably obtaining a light peeling property to an organic silicone adhesive, (B) curable silicone not containing a fluorine-substituted group is preferably a solvent type curable silicone.

[0065] As specific examples of the curable silicone not containing a fluorine substituent, for example, KNS-3051, KNS-320A, KNS-316, KNS-3002, KNS-3300, X-62-1387, KS-837, X-62-2829, KS-3650, KS-847, KS-847T, KS-776L, KS-776A, KS-774, KS-3703T, KS-3601, KS-830E, X-62-2825, X-62-9201-A, X-62-9201B, KM3951, KM-768, X-52-6015, KF-2005, X-62-7205, X-62-7028-A, X-62-7028-B, X-62-7052, X-62-7622, X-62-7660, X-62-7655 manufactured by Shin-Etsu Chemical Co., Ltd.; SP7017, SP7015, SP7025, SP7031, LTC1006L, LTC1063L, LTC1036M, LTC1056L, SRX357, SRX211, SRX345, SRX370, LTC300B, LTC310, LTC355A, LTC759, LTC755, LTC750A, LTC752, LTC761, LTC856, LTC851 manufactured by Dow Corning Toray Co., Ltd., and the like can be given. However, the present application is not limited to these.

[0066] In addition, a heavy release additive can be added to the aforementioned non-fluorinated curable silicone, and as examples thereof, KS-3800 manufactured by Shin-Etsu Chemical Co., Ltd.; SD7292, BY24-4980 manufactured by Dow Corning Toray Co., Ltd., and the like can be given.

[0067] The non-fluorinated curable silicone can be used alone, or two or more kinds of curable silicone having different reactive functional groups and viscosities can be mixed and used.

[0068] By mixing two or more kinds of non-fluorinated curable silicone, it is possible to adjust the curing reaction, or to adjust the viscosity of the coating liquid, and further, it is possible to improve the wettability and reactivity. At this time, it is possible to mix solventless silicone with each other, to mix solvent-containing silicone with each other, or to mix solventless silicone with solvent-containing silicone. In particular, in the case where the film thickness is thickened in order to obtain a release film with lighter release, there is a tendency that the solid content concentration of the coating liquid for forming the cured layer becomes high. Therefore, there is a possibility that the viscosity of the coating liquid increases, the coating appearance deteriorates, and the thickness unevenness becomes large. Therefore, by mixing solventless silicone with solvent-containing silicone, it is possible to reduce the viscosity of the coating liquid, and it is possible to form a cured layer having a good coating appearance and small thickness fluctuation.

[0069] Note that, as to the solvent type curable silicone and the non-solvent type curable silicone, as described above, the range of each preferable viscosity is also the same as the above range.

[0070] (Ratio of (A) to (B))

[0071] The mass ratio of (A) the aforementioned curable silicone having a fluorine substituent to (B) the aforementioned curable silicone not containing a fluorine substituent in the present release layer composition is preferably 1:50 to 10:1, further preferably 1:20 to 5:1, 1:10 to 2:1, or 1:5 to 1:1.

[0072] Note that, as described above, in the present application, the "curable silicone having a fluorine substituent" is particularly preferably a curable silicone cured by hydrosilylation addition reaction from the viewpoint of the availability of the material, and the like.

[0073] On the other hand, in the case of producing a "release film characterized in that, in the concentration distribution of fluorine atoms in the thickness direction of the release layer, the fluorine atom concentration at the surface of the release layer is higher than the fluorine atom concentration in the inside of the release layer" which is a feature of the present application, the curing method is not limited, and a curable silicone such as a condensation type or a UV curing type can be used.

[0074] ((C) Silicone Crosslinking Agent)

[0075] The "crosslinking agent" refers to a compound that links polymers to each other, such as a compound that can link two or more molecules by a chemical covalent bond.

[0076] As the silicone crosslinking agent, (C1) a silicone crosslinking agent not containing a fluorine substituent (also referred to as "non-fluorinated silicone crosslinking agent") and (C2) a silicone crosslinking agent containing a fluorine substituent (also referred to as "fluorinated silicone crosslinking agent") can be given.

[0077] Among them, from the viewpoint of making the effect of the pre-reaction described later more reliable, the bias of fluorine, that is, the effect of improving the easy peel property, and the effect of improving the residual adhesion rate, it is preferable to use (C1) a non-fluorinated silicone crosslinking agent. In addition, in the case of using a mixture of both, it is preferable to make the amount of (C1) more.

[0078] ((C1) Silicone Crosslinking Agent Not Containing a Fluorine Substituent)

[0079] As the "(C1) silicone crosslinking agent not containing a fluorine substituent", it is preferable to have at least two, preferably three or more (usually three to about 200), more preferably three to 100, particularly preferably three to 50 silicon atom-bonded hydrogen atoms (SiH group) in one molecule, as shown in the following general formula (1).

[0080] R b H c SiO (4-b-c) / 2 (1)

[0081] In formula (1), R is a monovalent hydrocarbon group having a carbon number of 1 to 10, which is unsubstituted or substituted. In addition, b is 0.7 to 2.1, particularly 0.8 to 2.0, c is 0.001 to 1.0, and b + c is a positive number satisfying 0.8 to 3.0, particularly 1.0 to 2.5.

[0082] Here, as R, the same groups as R in the organopolysiloxane containing an alkenyl group can be given, and it is preferable that R not have an aliphatic unsaturated bond such as an alkenyl group.

[0083] The silicon atom to which the hydrogen atom is bonded can be a silicon atom at the end of the molecular chain, a silicon atom in the middle of the molecular chain (non-end of the molecular chain), or both.

[0084] The molecular structure of the "(C1) organosilicon crosslinking agent not containing a fluorine substituent" can be linear, cyclic, branched, or three-dimensional network, and any of these is acceptable.

[0085] Further, the number of silicon atoms in one molecule (or the degree of polymerization) is preferably 2 to 1000, further preferably 3 or more and 500 or less, 3 or more and 300 or less, particularly 4 or more and 150 or less.

[0086] As the "(C1) organosilicon crosslinking agent not containing a fluorine substituent", the following can be given: tris(dimethylhydrogensiloxy)methylsilane, tris(dimethylhydrogensiloxy)phenylsilane, 1,1,3,3-tetramethyldisiloxane, 1,3,5,7-tetramethylcyclotetrasiloxane, methylhydrogencyclosiloxane, methylhydrogensiloxane / dimethylsiloxane cyclic copolymer, methylhydrogenpolysiloxane capped at both terminals with trimethylsiloxy groups, dimethylsiloxane / methylhydrogensiloxane copolymer capped at both terminals with trimethylsiloxy groups, dimethylpolysiloxane capped at both terminals with dimethylhydrogensiloxy groups, methylhydrogenpolysiloxane capped at both terminals with dimethylhydrogensiloxy groups, dimethylsiloxane / methylhydrogensiloxane copolymer capped at both terminals with dimethylhydrogensiloxy groups, methylhydrogensiloxane / diphenylsiloxane copolymer capped at both terminals with trimethylsiloxy groups, methylhydrogensiloxane / diphenylsiloxane / dimethylsiloxane copolymer capped at both terminals with trimethylsiloxy groups, (CH3)2HSiO 1 / 2 units, and SiO 4 / 2 units, (CH3)2HSiO 1 / 2 units, SiO 4 / 2 units, and (C6H5)SiO 3 / 2Examples of the copolymer or the like formed by the unit include those in which part or all of the methyl groups in the compound are replaced with ethyl groups, propyl groups, or other alkyl groups, phenyl groups, or aryl groups. However, the present application is not limited to these.

[0087] Note that two or more crosslinking agents are preferably used in combination.

[0088] The purpose of using in combination is to promote the crosslinking reaction.

[0089] The content (total content when multiple are used) of the "(C1) organosilicon crosslinking agent not containing a fluorine substituent" is preferably 0.1 to 50 parts by mass, and more preferably 0.3 parts by mass or more or 30 parts by mass or less, and 0.5 parts by mass or more or 20 parts by mass or less, relative to 100 parts by mass of the curable organosilicon ((A) + (B)).

[0090] In addition, the molar ratio of the silicon atom-bonded hydrogen atoms (SiH groups) in the (C) organosilicon crosslinking agent relative to the total amount of the silicon atom-bonded alkenyl groups in the (A) curable organosilicon having a fluorine substituent and the silicon atom-bonded alkenyl groups in the (B) curable organosilicon not containing a fluorine substituent is preferably 0.3 to 3.0, and more preferably 0.5 or more or 2.5 or less, and particularly 0.8 or more or 2.0 or less.

[0091] Specific examples of the "(C1) organosilicon crosslinking agent not containing a fluorine substituent" include 3062A, 3062B, 3062D, SP 7297, and the like manufactured by Dow Corning Toray Co., Ltd.

[0092] ((C2) organosilicon crosslinking agent containing a fluorine substituent)

[0093] On the other hand, as the (C2) organosilicon crosslinking agent containing a fluorine substituent, the aforementioned (1) in which R has a fluorine group can be given.

[0094] Specific examples include 3062C, Q2-7560, and the like manufactured by Dow Corning Toray Co., Ltd.

[0095] ((D) curing catalyst)

[0096] The "curing catalyst" is a catalyst for promoting the hydrosilylation addition reaction of the alkenyl group bonded to the silicon atom of the curable organosilicon with the hydrogen silane (SiH) group of the (C) organosilicon crosslinking agent.

[0097] As the curing catalyst, for example, platinum black, chloroplatinic acid, chloroplatinic acid with a monohydric alcohol, chloroplatinic acid with an olefin complex, platinum catalysts such as platinum diacetylacetate, palladium catalysts, rhodium catalysts, and platinum group metal catalysts can be given. However, the catalyst is not limited to these.

[0098] As the content of the curing catalyst in the present release layer composition or the present release layer, 0.5 to 500 mass ppm, further preferably 5 mass ppm or more and 500 mass ppm or less, and more preferably 10 mass ppm or more and 200 mass ppm or less, in terms of the metal content, relative to the total amount of the curable silicone ((A) + (B)) is preferable.

[0099] ((E) Reaction Control Agent)

[0100] The present release layer composition and the present release layer can contain a reaction control agent, as needed, in addition to the above-mentioned components.

[0101] As the (E) reaction control agent, an ethynyl alcohol represented by the following general formula (2) or the like can be used.

[0102] CH≡C-C(R2)(OH)R1(2)

[0103] In formula (2), R1is a linear or branched monovalent hydrocarbon group having 5 to 15 carbon atoms, and R2is a linear monovalent hydrocarbon group having 1 to 3 carbon atoms.

[0104] In the above formula (2), R1is preferably a linear or branched monovalent hydrocarbon group having 5 to 15 carbon atoms, and further preferably 6 to 14, and particularly preferably 8 to 12.

[0105] As specific examples of R1, alkyl groups such as pentyl, neopentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, and the like, alkenyl groups such as pentenyl, hexenyl, heptenyl, and the like can be given. However, the examples are not limited to these.

[0106] In the above formula (2), when the monovalent hydrocarbon group of R1has less than 5 carbon atoms, the control agent has high volatility, and the control effect is sometimes insufficient. On the other hand, when the number of carbon atoms is more than 15, the effective ingredient of the ethynyl alcohol per mol becomes less, and there is a tendency that the control effect becomes weak, and thus, there is a concern that a large amount of addition is necessary to obtain the desired control effect.

[0107] In the above formula (2), R2is a linear monovalent hydrocarbon group having 1 to 3 carbon atoms, and preferably 1 to 2. As specific examples of R2, alkyl groups such as methyl, ethyl, n-propyl, and the like, alkenyl groups such as vinyl, allyl, n-propenyl, and the like can be given. However, the examples are not limited to these. The smaller the number of carbon atoms of R2, the more the control effect of the silicone composition is exerted, and methyl can be preferable.

[0108] The reaction control agent can be one or two or more in combination as needed.

[0109] The content of the reaction control agent is preferably 0.001 to 5.0 parts by mass, further preferably 0.01 parts by mass or more and 1.0 parts by mass or less, 0.05 parts by mass or more and 0.5 parts by mass or less, per 100 parts by mass of the total amount of the present release layer composition.

[0110] (Other components)

[0111] The present release layer composition and the present release layer can further contain other components as needed in addition to the above components. For example, there can be mentioned silicone other than the curable silicone, silicone rubber, silicone resin, polyolefin resin, acrylic resin, urethane resin, epoxy resin, alkyd resin, cellulose and the like, copolymer and the like obtained by modifying these resins by graft polymerization or the like, various particles such as silica particles, alumina particles, silicone rubber particles, silicone resin particles, silicone rubber / resin composite particles, and silane coupling agent and the like. However, these are not limiting.

[0112] The present release layer composition and the present release layer can contain, as needed, for example, a light release agent, a heavy release agent, a crosslinking agent, an adhesion improver.

[0113] As specific examples of the light release agent, the heavy release agent, and the adhesion improver, there can be mentioned KS-3800, X-92-185 manufactured by Shin-Etsu Chemical Co., Ltd., BY24-850, SD7292, BY24-4980, SP7297, BY24-808, SD7200 manufactured by Dow Corning Toray Co., Ltd., and the like. However, these are not limiting.

[0114] (Solid component)

[0115] Note that the solid component concentration of the present release layer composition is preferably 0.1 to 100 mass%, further preferably 0.5 mass% or more and 50 mass% or less, 1.0 mass% or more and 20 mass% or less, 1.5 mass% or more and 10 mass% or less.

[0116] The alkylvinylpolysiloxane and the alkylhydrogenpolysiloxane are contained in the solid component of the present release layer composition. Of these, the amount of the alkylvinylpolysiloxane containing a vinyl group (an alkenyl group) is preferably 85.0 to 99.9 mass%, further preferably 90.0 mass% or more and 99.5 mass% or less, 92.0 mass% or more and 99.0 mass% or less, per 100 mass of the solid component.

[0117] (Film thickness of the present release layer)

[0118] The film thickness of the present release layer is not particularly limited. If the film thickness of the release layer is thick, there is a tendency to prefer that the influence of the substrate, such as the hardness of the substrate, is not transmitted to the release surface of the present release film, and it is preferably 0.01 μm or more, further preferably 0.05 μm or more, 0.10 μm or more. On the other hand, if the film thickness of the present release layer is too thick, it sometimes causes the occurrence of blocking, deterioration of the coating appearance, and the like, and thus it is preferably 10 μm or less, further preferably 5 μm or less, 1 μm or less, 0.5 μm or less, particularly preferably 0.25 μm or less.

[0119] <The substrate film>

[0120] The present substrate film is not particularly limited as long as it is in the form of a film. For example, it can be paper, resin, metal, or the like. Among them, from the viewpoint of mechanical strength and flexibility, it is preferably resin.

[0121] As the resin substrate film, for example, a film in which a polymer such as polyethylene, polypropylene, polyester, polystyrene, polycarbonate, polyethersulfone, polyamide, polyimide, or the like is formed into a film shape can be given. However, it is not limited thereto. In addition, as long as it can be filmized, it can be a mixture of these materials (polymer blend), and it can also be a composite structure unit (copolymer).

[0122] Among the above-described examples of the film, a polyester film is particularly preferred because of its excellent heat resistance, planarity, optical properties, strength, and the like.

[0123] The above-described polyester film can be a single layer, or a multilayer film (laminated film) having two or more layers with different properties.

[0124] In addition, the polyester film can be a non-stretched film (sheet), or a stretched film. Among them, a stretched film stretched in a uniaxial direction or a biaxial direction is preferred. Among them, a biaxially stretched film is more preferred from the viewpoint of the balance of mechanical properties and planarity.

[0125] The polyester as the main component resin of the above-described polyester film can be a homopolymer polyester, or a copolymer polyester.

[0126] Note that the main component resin refers to a resin having the largest mass ratio among the resins constituting the polyester film, and it is assumed to account for 50 mass% or more, or 75 mass% or more, or 90 mass% or more, or 100 mass% of the resins constituting the polyester film.

[0127] As the above homopolymer polyester, one in which an aromatic dicarboxylic acid is polycondensed with an aliphatic diol is preferable. As the aromatic dicarboxylic acid, terephthalic acid, 2,6-naphthalene dicarboxylic acid, etc. can be given, and as the aliphatic diol, ethylene glycol, diethylene glycol, 1,4-butanediol, 1,4-cyclohexane dimethanol, etc. can be given. However, these are not limiting.

[0128] As a representative homopolymer polyester, polyethylene terephthalate (PET), polybutylene terephthalate (PBT), etc. can be given.

[0129] On the other hand, in the case of the above polyester being a copolymer polyester, a copolymer containing 30 mol% or less of a third component is preferable.

[0130] As the dicarboxylic acid component of the copolymer polyester, one or two or more of isophthalic acid, phthalic acid, terephthalic acid, 2,6-naphthalene dicarboxylic acid, adipic acid, sebacic acid, etc. can be given, and as the diol component, one or two or more of ethylene glycol, diethylene glycol, propylene glycol, 1,4-butanediol, 1,4-cyclohexane dimethanol, neopentyl glycol, etc. can be given. However, these are not limiting.

[0131] Among these, as the main component resin of the base material film, polyethylene terephthalate in which 60 mol% or more, preferably 80 mol% or more is a polyethylene terephthalate unit is preferable.

[0132] The base material film can also contain particles for the main purpose of imparting easy sliding properties and preventing the occurrence of scratches in each process. In the case of containing particles, the kind of the contained particles is not particularly limited as long as it is a particle that imparts easy sliding properties, and as specific examples, for example, inorganic particles such as silicon dioxide, calcium carbonate, magnesium carbonate, barium carbonate, calcium sulfate, calcium phosphate, magnesium phosphate, kaolin, alumina, titanium oxide, etc., organic particles such as acrylic resin, styrene resin, urea resin, phenol resin, epoxy resin, benzoguanamine resin, etc. can be given. However, these are not limiting. Furthermore, precipitated particles obtained by precipitating and finely dispersing a part of a metal compound such as a catalyst in the manufacturing process of the polyester can also be used.

[0133] On the other hand, the shape of the particles used is also not particularly limited, and any of a spherical shape, a block shape, a rod shape, a flat shape, etc. can be used. In addition, the hardness, specific gravity, color, etc. are also not particularly limited. Two or more of these series of particles can be used in combination as needed.

[0134] The average particle diameter of the particles is preferably in the range of 5 μm or less, more preferably 0.1 μm or more and 3 μm or less. By using an average particle diameter in the above range, a moderate surface roughness can be provided to the film, and good sliding properties and smoothness can be ensured.

[0135] Note that the average particle diameter of the above-mentioned particles can be measured as follows.

[0136] The average particle diameter of the particles used as a raw material can be measured as the average particle diameter (D50) calculated from a volume-based particle size distribution measured by a dynamic light scattering method or the like.

[0137] The average particle diameter of the particles contained in the base film can be calculated as follows: the surface or cross section of the base film is observed using an optical microscope or a scanning electron microscope (SEM), the diameters of 10 or more particles are measured, and the average value thereof is calculated. In this case, when the cross-sectional shape is elliptical, the average of the longest diameter and the shortest diameter can be measured as the diameter of each particle.

[0138] Further, the content of the particles in the base film is preferably 5% by mass or less, and more preferably 0.0003% by mass or more or 3% by mass or less. When there are no particles or when the content of the particles is small, the transparency of the film becomes high, and a good film is obtained, but the sliding property is sometimes insufficient, and thus, it is sometimes necessary to improve the sliding property or the like by incorporating particles in the coating layer. When the content of the particles is too large, the transparency of the film is sometimes insufficient.

[0139] <Examples of the configuration of the release film>

[0140] The release film can be configured only with the release layer on one side or both sides of the base film, and thus, as described later, the base film and the release layer can be directly laminated on one side or both sides of the release film, or can be laminated on one side or both sides of the release film with the aid of other layers.

[0141] As the above-mentioned "other layer", for example, an anchor coat layer for improving the adhesion between the base film and the release layer, an oligomer encapsulation layer for preventing the bleed or plate out of a compounding material or an oligomer to the surface of the film, an antistatic layer having antistatic properties, and the like can be given. However, the present application is not limited to these.

[0142] As specific examples of the constitution of the present release film, the following can be given: the present base film / the present release layer, the present base film / anchor coat layer / the present release layer, the present base film / antistatic layer / the present release layer, the present base film / oligomer encapsulation layer / the present release layer, antistatic layer / the present base film / antistatic layer / the present release layer, oligomer encapsulation layer / the present base film / oligomer encapsulation layer / the present release layer, the present base film / antistatic layer / oligomer encapsulation layer / the present release layer, the present release layer / the present base film / the present release layer, the present release layer / anchor coat layer / the present base film / anchor coat layer / the present release layer, the present release layer / antistatic layer / the present base film / antistatic layer / the present release layer, the present release layer / oligomer encapsulation layer / the present base film / oligomer encapsulation layer / the present release layer, the present release layer / oligomer encapsulation layer / antistatic layer / the present base film / antistatic layer / oligomer encapsulation layer / the present release layer, and the like. However, the present application is not limited to these.

[0143] (anchor coat layer)

[0144] As the aforementioned anchor coat layer, for example, those made of polyethylene, polypropylene, styrene-based copolymer, polyester, polyurethane, polyvinyl alcohol, polyethylene imine, polyacrylate, polymethacrylate, modified products containing these, and the like high molecular materials can be given. However, the present application is not limited to these.

[0145] (oligomer encapsulation layer)

[0146] The aforementioned oligomer encapsulation layer can contain a hydrolyzable alkoxysilicate and / or a condensate thereof. As the hydrolyzable alkoxysilicate, those having a structure shown in the following general formula (3) can be given (R1 represents a hydrocarbon group having a carbon number of 1 to 10).

[0147] Si(OR 1 )4(3)

[0148] In formula (3), R 1 represents a hydrocarbon group having a carbon number of 1 to 10.

[0149] The aforementioned oligomer encapsulation layer can further contain inorganic particles, and as specific examples of the inorganic particles, silica, alumina, kaolin, calcium carbonate, titanium oxide, barium salt, and the like can be given. However, the present application is not limited to these.

[0150] In addition, the aforementioned oligomer encapsulation layer can contain a defoaming agent, a coating property modifier, a thickening agent, an organic lubricant, an organic high molecular particle, an antioxidant, an ultraviolet absorber, a foaming agent, a dye, and the like. However, the present application is not limited to these.

[0151] (antistatic layer)

[0152] From the viewpoint of imparting antistatic properties, the antistatic layer preferably contains an electroconductive polymer and a binder polymer.

[0153] Note that other components can be contained in the coating liquid within a range not impairing the gist of the present application.

[0154] The aforementioned electrically conductive polymer preferably contains, in particular, a polythiophene and derivatives thereof (I) represented by the following formula (4).

[0155] Formula (4)

[0156]

[0157] In the aforementioned formula (4), R1, R2 each independently represents a hydrogen element, an aliphatic hydrocarbon group having a carbon number of 1 to 12, an alicyclic hydrocarbon group, or an aromatic hydrocarbon group, for example, a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a cyclohexylidene group, a phenyl group, or the like. However, the present application is not limited to these.

[0158] Note that the aforementioned anchor coat layer, antistatic layer, oligomer encapsulation layer, and the like can be formed by any of an in-line coating method in which a substrate is formed into a film at the same time, and an off-line coating method in which a layer is formed in a process different from that in which the substrate film is formed. As a specific example of the in-line coating method, for example, a method in which coating is performed at any stage from the stage at which polyester is melt-extruded to be biaxially stretched and then heat-set to be wound up. Typically, a method in which coating is performed on any of an unstretched sheet obtained by melt / quenching in a substantially amorphous state, a uniaxially stretched film stretched in the length direction (longitudinal direction) after that, or a biaxially stretched film before heat-setting.

[0159] <<Method for manufacturing the present release film>>

[0160] Next, an example of a method for manufacturing the present release film will be described.

[0161] Generally, in a release film, as a countermeasure to reduce the amount of use of organosilicon having a fluorine substituent (fluorinated organosilicon), for example, a countermeasure such as reducing the content ratio of fluorinated organosilicon in the release layer or thinning the film thickness of the release layer is considered. However, in the former method, the easy peeling property as the original purpose is impaired, or in the latter method, there are problems such as the release layer cannot be formed uniformly or the stability of the peeling force is reduced.

[0162] In addition, it is considered that by using a combination of (A) a curable organosilicon having a fluorine substituent (referred to as "fluorinated curable organosilicon") and (B) a curable organosilicon not containing a fluorine substituent (also referred to as "non-fluorinated curable organosilicon"), the easy peeling property is maintained, and the amount of use of fluorinated organosilicon is reduced.

[0163] However, in the case where a solution in which (A) a fluorinated curable silicone and (B) a non-fluorinated curable silicone are mixed is applied to a film and dried, it is confirmed that (A) the fluorinated curable silicone, which is more highly hydrophobic, easily segregates on the surface (air interface) side. On the other hand, as for the silicone crosslinking agent and the catalyst used in combination, since they do not have a high hydrophobicity at a level equivalent to that of (A) the fluorinated curable silicone due to their molecular structures, they cannot be uniformly dispersed in the film, and it is confirmed that a release layer having a good cured state cannot be obtained, or (B) the non-fluorinated curable silicone cannot be mixed in a large amount, and the like.

[0164] Therefore, in the present application, in the formation of the release layer, first, a process of mixing (A) a curable silicone having a fluorine substituent, (C) a silicone crosslinking agent, and (D) a curing catalyst, and stirring and / or standing to allow them to react, that is, "preprocessing", is performed, and then (B) a curable silicone not having a fluorine substituent is mixed to prepare a release layer composition, so that even when (C1) a silicone crosslinking agent not having a fluorine substituent is used as the aforementioned (C) silicone crosslinking agent, uniform dispersion can be achieved, and a coating film that is more easily peeled from an organic adhesive (light peelability) can be formed.

[0165] That is, as an example of a preferred production method of the present release film, for example, a method in which "preprocessing" of mixing (A) a fluorinated curable silicone, (C) a silicone crosslinking agent, and (D) a curing catalyst, and then stirring and / or standing can be mentioned. Then, the preprocessing composition obtained in the preprocessing is mixed with (B) a non-fluorinated curable silicone to prepare the present release layer composition, and the present release layer composition is applied to at least one side of the present base film to produce the present release film. However, the production method is not limited to this.

[0166] In order to perform "preprocessing" of mixing (A) a fluorinated curable silicone, (C) a silicone crosslinking agent, and (D) a curing catalyst, and then stirring and / or standing, a slight time interval is provided, and thus crosslinking reaction (also referred to as "pre-crosslinking") can be performed in the aforementioned mixed solution at room temperature.

[0167] At this time, the aforementioned "stirring and / or standing", that is, "preprocessing", can be other means as long as crosslinking reaction can be performed, and the time is preferably 10 seconds or more, further preferably 1 minute or more, particularly preferably 3 minutes or more, 5 minutes or more, or 15 minutes or more. The upper limit of the preprocessing time is not particularly limited. From the viewpoints of solvent evaporation and workability, it is preferably 1 week or less, further preferably 3 days or less, and particularly preferably 1 day or less.

[0168] Note that if the cross-linking reaction is excessively advanced, there is a possibility that a liquid white turbidity or gelation will occur depending on the type of material. Therefore, it is preferable to add (or supplement) a reaction control (inhibitor) (acetylene alcohol derivative, etc.) after a prescribed pre-cross-linking time. The reaction control agent can be added to the non-fluorinated curable silicone (or a compounded liquid thereof) described later.

[0169] As the (C) silicone cross-linking agent, a silicone cross-linking agent not containing a fluorine substituent is preferably used as described above.

[0170] The pretreatment composition obtained in the above pretreatment is preferably mixed with the (B) non-fluorinated curable silicone, and then, if necessary, diluted with a solvent to prepare the present release layer composition.

[0171] As the solvent for dilution, either a polar solvent or a non-polar solvent can be used. Furthermore, two or more of the above solvents can be mixed and used.

[0172] As the aforementioned polar solvent, alcohols such as ethanol, (iso)propanol, esters such as methyl acetate, ethyl acetate, (iso)propyl acetate, (iso)butyl acetate, (iso)amyl acetate, ethyl lactate, ethyl benzoate, ketones such as methyl ethyl ketone, methyl isobutyl ketone, cyclopentanone, cyclohexanone, diacetone alcohol, diisobutyl ketone, glycols such as ethylene glycol, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, N-methyl-2-pyrrolidone, N,N-dimethylformamide, tetrahydrofuran, acetonitrile, and the like can be exemplified. However, the present application is not limited to these.

[0173] As the aforementioned non-polar solvent, aromatic hydrocarbons such as benzene, toluene, xylene, aliphatic hydrocarbons such as hexane, heptane, octane, hydrocarbons having a branched structure such as isohexane, isooctane, isononane, alicyclic hydrocarbons such as cyclohexane, cycloheptane, cyclooctane, ethers such as diisopropyl ether, dioxane, and the like can be exemplified. As the fluorine solvent, hydrofluoroethers, m-xylene hexafluoride, tridecafluorooctane, and the like can be exemplified. However, the present application is not limited to these.

[0174] As the method of applying the present release layer composition to the present base film, for example, the coating techniques described in "Kakuo-ho-shi" (Yuzi Harasaki, Shobido, published in 1979) can be used. For example, as the coating head, an air doctor coater, a blade coater, a bar coater, a knife coater, a press coater, a dip coater, a reverse roll coater, a transfer roll coater, a gravure coater, a roll kiss coater, a casting coater, a spray coater, a curtain coater, a calender coater, an extrusion coater, and the like can be exemplified. However, the present application is not limited to these.

[0175] (Method of forming other layers)

[0176] The present release film can be formed by coating the release layer composition and curing after forming the "other layer" such as an anchor coat layer, an antistatic layer, an oligomer encapsulation layer, and the like on one side or both sides of the base film as needed.

[0177] In the case where the "other layer" is formed as such, the release layer composition is coated and cured after forming the "other layer" such as an anchor coat layer, an antistatic layer, an oligomer encapsulation layer, and the like on at least one side of the base film wound out from the roll as needed, thereby forming the release layer.

[0178] <Properties of the present release film>

[0179] The present release film can have the following properties.

[0180] (Normal peel force)

[0181] The normal peel force of the present release layer is preferably 75 mN / cm or less, further preferably 60 mN / cm or less, particularly 50 mN / cm or less, and more particularly 40 mN / cm or less. The lower the normal peel force, the less force is required for peeling from the silicone adhesive, and the occurrence of defects such as failure of peeling and deformation of the adhesive layer in the production process can be suppressed. In addition, by using a release film having excellent light peeling properties, the phenomenon in which the release film on the unintended side is peeled off in a double-coated tape having release films on both sides of the adhesive sheet can be prevented.

[0182] On the other hand, there is no particular limitation on the lower limit. In terms of long-term storage of a laminate in which a release film and an adhesive are laminated, 1 mN / cm or more is preferable.

[0183] Note that the normal peel force can be measured by adhering a double-coated tape "Polyimide Tape No. 5413 with Silicone Adhesive (manufactured by 3M Company)" having a width of 5 cm, and measuring the peel force at 180° using a peel tester at a rate of 0.3 m / min in an environment at room temperature, i.e., 23°C.

[0184] (Heating peel force)

[0185] The heating peel force of the present release layer is preferably 100 mN / cm or less, further preferably 80 mN / cm or less, and particularly 60 mN / cm or less.

[0186] It is considered that the heating peel force is correlated with the amount of reactive groups (hydrogen silane groups (Si-H groups) and the like) remaining on the surface of the release layer after curing is formed on the film. It is shown that the closer the value to the normal peel force, the smaller the amount of reactive groups remaining on the surface.

[0187] Note that the heat release force is obtained as follows: after the adhesive tape is adhered to the polyimide tape "No. 5413 (manufactured by 3M Company) with a silicone adhesive", the sample is cut into a size of 50 mm x 300 mm, heat-treated at 100°C for 1 hour in a hot air oven, and then the sample is taken out, and the release force after 1 hour at room temperature is measured, whereby the heat release force is obtained. The release force at this time can be measured, for example, using "EZ Graph" manufactured by Shimadzu Corporation, under the conditions of a tensile speed of 0.3 (m / minute) and 180° peeling.

[0188] (Residual Adhesion Rate)

[0189] The residual adhesion rate of the present release layer is preferably 80% or more, and further preferably 90% or more, 95% or more.

[0190] By satisfying the above range, the transfer of the release layer component from the surface to the adherend surface of the object to be attached is reduced.

[0191] Note that the residual adhesion rate is an index for confirming the transfer of the release agent, and is a value expressed by the ratio of the adhesion after peeling to the initial adhesion at room temperature, i.e., 23°C, which is obtained by adhering the adhesive tape to the release agent coated surface or the like (JIS Z 0109:2015).

[0192] <<Present Film Laminated Body>>

[0193] As the film laminated body (referred to as "present film laminated body") related to an example of the embodiment of the present application, a configuration in which the above-described present release film is attached to a "laminated film having a functional layer" via a silicone adhesive layer can be cited.

[0194] <Layered Film (1)>

[0195] As the aforementioned "laminated film having a functional layer", for example, a laminated film (referred to as "layered film (1)") having a layer having a structure in which a crosslinked resin layer is formed on at least one side of a base film can be cited.

[0196] At this time, the aforementioned crosslinked resin layer can be exemplified by a crosslinked resin layer composition containing a conductive polymer and a binder polymer, and containing a crosslinking agent and a particle as necessary.

[0197] (Conductive Polymer)

[0198] As the aforementioned conductive polymer, a composition containing the aforementioned polythiophene and polyanion, or a composition containing the aforementioned polythiophene derivative and polyanion is preferable.

[0199] The aforementioned polyanion refers to "an acidic polymer in a free acid state", and is preferably a high-molecular carboxylic acid, or a high-molecular sulfonic acid, a polyvinyl sulfonic acid, or the like. As specific examples of the high-molecular carboxylic acid, polyacrylic acid, polymethacrylic acid, polymaleic acid are exemplified. As specific examples of the high-molecular sulfonic acid, polystyrene sulfonic acid is exemplified. Among these, polystyrene sulfonic acid is most preferable in terms of conductivity. Note that a salt in which a part of the free acid is neutralized can be used. It is considered that by using these polyanions at the time of polymerization, the polythiophene-based compound, which is originally insoluble in water, is easily water-dispersible or water-soluble, and the function as an acid also functions as the function of a dopant for the polythiophene-based compound.

[0200] In addition, the high-molecular carboxylic acid and the high-molecular sulfonic acid can also be used in a form copolymerized with other monomers copolymerizable therewith, such as an acrylate, a methacrylate, a styrene, or the like. The molecular weight of the high-molecular carboxylic acid and the high-molecular sulfonic acid used as the polyanion is not particularly limited, and in terms of stability of the coating agent and conductivity, the weight average molecular weight thereof is preferably from 1000 to 1,000,000, and more preferably from 5000 to 150,000. Within a range not impairing the characteristics of the present application, a part of a lithium salt, a sodium salt, or the like, an ammonium salt, or the like can be contained. In the case of a salt after neutralization, it is considered that polystyrene sulfonic acid and an ammonium salt, which function as a very strong acid, are shifted to the acidic side by the progress of the equilibrium reaction after neutralization, and thus it is considered that they function as a dopant.

[0201] In terms of conductivity, it is preferable that the polyanion be present in excess of the polythiophene or the polythiophene derivative in terms of solid content mass ratio, and the polyanion is preferably from 1 part by mass to 5 parts by mass, and more preferably from 1 part by mass to 3 parts by mass, relative to 1 part by mass of the polythiophene or the polythiophene derivative. As for the composition containing the aforementioned polythiophene or the polythiophene derivative and the polyanion, examples are described in Japanese Patent Application Publication No. H6-295016, Japanese Patent Application Publication No. H7-292081, Japanese Patent Application Publication No. H1-313521, Japanese Patent Application Publication No. 2000-6324, European Patent No. EP602731, U.S. Patent No. 5391472, and the like, but it can be a method other than these. If one example is cited, an alkali metal salt of 3,4-dihydroxythiophene-2,5-dicarboxylate is used as a starting material, 3,4-vinylenethiophene is obtained, and then potassium peroxydisulfate, iron sulfate, and the aforementioned obtained 3,4-vinylenethiophene are introduced into an aqueous solution of polystyrene sulfonic acid, and allowed to react, thereby obtaining a composition in which polystyrene sulfonic acid or the like is complexed in a polythiophene such as poly(3,4-vinylenethiophene).

[0202] For example, examples are also described in the latest trend of conductive polymers (Toray Research Center Co., Ltd. issued on June 1, 1999, 1st edition).

[0203] (binder polymer)

[0204] The binder polymer constituting the crosslinked resin layer composition is defined as a high molecular compound having a number average molecular weight (Mn) of 1000 or more measured based on gel permeation chromatography (GPC) and having film-forming properties according to the High Molecular Compound Safety Evaluation Procedure (November 1960, organized by the Chemical Substance Review Council).

[0205] As the binder polymer constituting the crosslinked resin layer composition, a thermosetting resin or a thermoplastic resin can be used as long as it is compatible or mixedly dispersed with the ionic polymer. For example, the following can be mentioned: polyesters such as polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, and the like; polyimides such as polyimide, polyamide-imide, and the like; polyamides such as polyamide 6, polyamide 6,6, polyamide 12, polyamide 11, and the like; fluororesins such as polyvinylidene fluoride, polyfluoroethylene, polytetrafluoroethylene, ethylene-tetrafluoroethylene copolymer, polychlorotrifluoroethylene, and the like; vinyl resins such as polyvinyl alcohol, polyvinyl ether, polyvinyl butyral, polyvinyl acetate, polyvinyl chloride, and the like; epoxy resins; oxetane resins; xylene resins; aromatic polyamide resins; polyimide silicone; polyurethane; polyurea; melamine resins; phenol resins; polyethers; acrylic resins; and copolymers thereof. One or two or more of them can be used in combination. However, the binder polymer is not limited to these.

[0206] The binder polymer as a raw material can be dissolved in an organic solvent, can be water-solubilized by imparting a functional group such as a hydroxyl group, a sulfo group, a carboxyl group, or the like, or can be water-dispersed by using a surfactant in combination. In addition, a curing agent such as a crosslinking agent, a polymerization initiator, a polymerization accelerator, a solvent, a viscosity modifier, or the like can be used in combination as needed in the binder polymer.

[0207] Of the aforementioned binder polymers, from the viewpoint of adhesion to the release layer, it is preferable to use any one or more selected from the group consisting of polyester resins, acrylic resins, polyurethane resins, and vinyl resins.

[0208] The content of the binder polymer in the crosslinked resin layer composition is preferably 5 to 90% by mass, more preferably 10 to 70% by mass, and further preferably 10 to 60% by mass, based on the solid content. If the content of the binder polymer is within the above range, the strength of the obtained crosslinked resin layer and the adhesion to the release layer can be sufficiently obtained.

[0209] (crosslinking agent)

[0210] A crosslinking agent can be included in the crosslinked resin layer composition as needed.

[0211] The cross-linking agent can improve the cohesiveness, surface hardness, scratch resistance, solvent resistance, water resistance, and the like of the cross-linked resin layer by cross-linking reactions with the functional groups contained in other resins or compounds, and self-cross-linking.

[0212] The cross-linking agent can be any kind. For example, melamine compounds, guanamine-based, alkylamide-based, and polyamide-based compounds, glyoxal-based, carbodiimide compounds, epoxy compounds, oxazoline compounds, aziridine compounds, isocyanate compounds, silane coupling agents, diol aluminate-based coupling agents, dialdehyde compounds, zirconium aluminate-based coupling agents, peroxides, heat- or light-reactive vinyl compounds, photosensitive resins, and the like are suitable for use. Among these, from the viewpoint of synergistically obtaining good adhesion to the release layer, cross-linking agents such as melamine compounds, epoxy compounds, and silane coupling agents are preferred.

[0213] In addition, among these cross-linking agents, there are also polymer-type cross-linking reactive compounds having reactive groups in other polymer skeletons, and one or two or more of these cross-linking agents can be used in combination in the present application.

[0214] The content of the cross-linking agent in the cross-linked resin layer composition is preferably 1 to 90% by mass, more preferably 3 to 50% by mass, and further preferably 5 to 40% by mass, based on the solid content. If the ratio of the cross-linking agent is within the above range, adhesion to the release layer based on synergistic effects with the binder polymer can be sufficiently obtained.

[0215] (Particulate)

[0216] To improve the cohesiveness and slidability of the cross-linked resin layer, the cross-linked resin layer can contain particulates.

[0217] The average particle diameter of the particulate is not particularly limited. For example, in the case of use in optical applications, from the viewpoint of the transparency of the film, it is preferably 1.0 μm or less, more preferably 0.5 μm or less, and further preferably 0.2 μm or less. Also, from the viewpoint of obtaining improvements in the cohesiveness and slidability of the cross-linked resin layer, it is preferably 0.01 μm or more.

[0218] Specific examples of the particulate include non-reactive inorganic particulates such as silica, alumina, calcium carbonate, and titanium dioxide, microparticles obtained from polystyrene-based resins, polyacrylic resins, and polyvinyl-based resins, and organic particulates represented by these cross-linking particulates, and the like.

[0219] Note that the average particle diameter of the above particulate can be measured as follows.

[0220] The average particle diameter of the particulate as a raw material can be measured as the average particle diameter (D50) obtained from the volume-based particle size distribution measured by dynamic light scattering or the like.

[0221] The average particle diameter of the particles contained in the crosslinked resin layer can be found by using an optical microscope, a scanning electron microscope (SEM), observing the surface or cross section of the crosslinked resin layer, measuring the diameters of 10 or more particles, and finding the average value thereof. In this case, when the cross-sectional shape is elliptical, the average value of the longest diameter and the shortest diameter can be measured as the diameter of each particle.

[0222] (Other)

[0223] The crosslinked resin layer can contain, as needed, a surfactant, an antifoaming agent, a coating property modifier, a release agent, a thickening agent, an organic lubricant, an antistatic agent, a conductive agent, a light absorber such as an ultraviolet absorber, an antioxidant, a foaming agent, a dye, a pigment, and the like.

[0224] The analysis of the components in the crosslinked resin layer can be performed by, for example, TOF-SIMS, ESCA, fluorescence X-ray, and the like.

[0225] (Formation method of crosslinked resin layer)

[0226] As for the formation method of the crosslinked resin layer, the following methods can be adopted: a method in which the surface of the film is treated in the stretching process of the polyester film, a method in which the film is coated by online coating, and a method in which the film is coated by offline coating. The film can be coated simultaneously with the film production, and thus, in terms of being able to inexpensively cope with the production and being able to change the thickness of the crosslinked resin layer according to the stretching ratio, it is preferable to use online coating.

[0227] As for the online coating, it is not limited to the following, and for example, the coating treatment can be performed before the transverse stretching, particularly, before the longitudinal stretching is completed, in the sequential biaxial stretching. In the case where the crosslinked resin layer is provided on the polyester film by online coating, the film can be coated simultaneously with the film production, and the crosslinked resin layer can be treated at a high temperature, and thus, a film suitable as a polyester film can be produced.

[0228] In the case where the crosslinked resin layer is provided by online coating, it is preferable to coat the coating liquid on the polyester film by the gist of producing an aqueous solution or an aqueous dispersion of a crosslinked resin layer composition containing the above-described series of compounds. In addition, within a range not impairing the gist of the present application, a small amount of an organic solvent can be contained in the coating liquid for the purpose of improving the dispersibility in water, improving the film production property, and the like. The organic solvent can be used alone or in combination with two or more kinds.

[0229] The content of the organic solvent in the coating liquid is preferably 10% by mass or less, further preferably 5% by mass or less. As specific examples of the organic solvent, aliphatic or alicyclic alcohols such as n-butanol, n-propanol, isopropanol, ethanol, and methanol; glycols such as propylene glycol, ethylene glycol, and diethylene glycol; glycol derivatives such as n-butyl cellosolve, ethyl cellosolve, methyl cellosolve, and propylene glycol monomethyl ether; ethers such as dioxane and tetrahydrofuran; esters such as ethyl acetate and amyl acetate; ketones such as methyl ethyl ketone and acetone; and amides such as N-methylpyrrolidone can be given.

[0230] In addition, either heat treatment or irradiation of active energy rays such as ultraviolet rays can be used in combination as needed, either offline or online.

[0231] As the method of forming the crosslinked resin layer, for example, gravure coating, reverse roll coating, die coating, air doctor coating, blade coating, rod coating, bar coating, curtain coating, knife coating, transfer roll coating, squeeze coating, curtain coating, impregnated coating, kiss coating, spray coating, calendar coating, extrusion coating, and the like, which are conventionally known coating methods, can be used.

[0232] (Thickness of the Crosslinked Resin Layer)

[0233] When considered as a final coating film, the thickness of the crosslinked resin layer is preferably 0.01 μm to 3 μm, further preferably 0.02 μm or more and 1 μm or less, or 0.03 μm or more and 0.3 μm or less, from the viewpoint of embodying various functional properties.

[0234] Note that the coating amount of the coating liquid containing the crosslinked resin layer composition is usually 0.01 to 3 g / m2, preferably 0.01 to 1 g / m2, further preferably 0.01 to 0.3 g / m2. 2 , preferably 0.01 to 1 g / m 2 , further preferably 0.01 to 0.3 g / m 2 If it is 0.01 g / m 2The above can achieve sufficient performance in terms of adhesion to the release layer (easy adhesion performance) and antistatic performance if the release layer has a thickness of 3 g / m 2 The following, the appearance / transparency of the crosslinked resin layer is good, and there is no concern about causing adhesion of the film, reduction in line speed, and reduction in productivity.

[0235] The coating amount in the present application can be calculated from the liquid mass (before drying) per unit time of coating, the concentration of non-volatile components of the coating liquid, the coating width, the stretching ratio, the line speed, and the like.

[0236] <Layered film (2)>

[0237] As the aforementioned "layered film having a functional layer", for example, a release film (referred to as "layered film (2)") having "another release layer" on one side of the base film can be cited.

[0238] As an example of the aforementioned "another release layer", a layer formed by sequentially having a first layer and a second layer can be cited, wherein the first layer is formed from a silicone composition containing (B) a cured-type silicone not containing a fluorine substituent as a main component, and the second layer contains a component having a fluorine substituent.

[0239] As another example of the aforementioned "another release layer", a layer formed from a silicone composition containing (A) a cured-type silicone containing a fluorine substituent as a main component can be cited.

[0240] Further as another example of the aforementioned "another release layer", a layer formed from a silicone composition containing (B) a cured-type silicone not containing a fluorine substituent as a main component can be cited.

[0241] The aforementioned "main component" means a component having the largest mass ratio among the components.

[0242] <Use of the present film layered body>

[0243] From the viewpoint that a silicone adhesive having good durability and transparency can be used, the present film layered body is preferably used for the attachment of a member for a vehicle.

[0244] <Method for using the present release film and the present film layered body>

[0245] The present release film has excellent release properties with respect to a silicone adhesive, and thus, as a light release film with respect to a silicone adhesive, can be used as follows.

[0246] That is, in a film laminate having a structure in which a release film (referred to as "light release film") is laminated on one side of a silicone adhesive layer formed of a silicone adhesive, and a release film (referred to as "heavy release film") having a higher release strength than the aforementioned release film is laminated on the other side of the silicone adhesive layer, after the aforementioned light release film is peeled off, the exposed surface of the silicone adhesive layer is attached to an "adherend", and after the silicone adhesive layer is cured, the aforementioned heavy release film can be peeled off and used. However, the use method is not limited to the aforementioned method.

[0247] As the aforementioned adherend, various process papers, backing papers, optical members, and the like can be given.

[0248] As the aforementioned optical member, a polarizing plate, a touch sensor, and the like can be given.

[0249] In addition, the silicone adhesive itself has heat resistance, cold resistance, weather resistance, and high transparency, and can be used for a touch panel mounted on a car, and the like.

[0250] (Silicone Adhesive)

[0251] The aforementioned silicone adhesive is an adhesive in which a silicone is a main component resin.

[0252] The "main component resin" refers to a resin having the largest ratio (mass) among resins constituting the adhesive.

[0253] The aforementioned silicone adhesive can be, for example, an addition reaction type, a peroxide curing type, or a condensation reaction type silicone adhesive. Among them, from the viewpoint that curing can be performed in a short time at a low temperature, an addition reaction type silicone adhesive is preferably used. Note that these addition reaction type silicone adhesives are cured when an adhesive layer is formed on a support.

[0254] In the case where an addition reaction type silicone adhesive is used as the aforementioned silicone adhesive, the aforementioned silicone adhesive can include a catalyst such as a platinum catalyst.

[0255] For example, for the aforementioned addition reaction type silicone adhesive, a catalyst such as a platinum catalyst can be added, an organic silicone resin solution diluted with a solvent such as toluene as needed is stirred to be uniform, and then applied to a support, and cured at 100 to 130°C for 1 to 5 minutes.

[0256] In addition, as needed, a crosslinking agent, an additive for controlling adhesion, or the like can be added to the aforementioned addition reaction type silicone adhesive, or a primer treatment can be performed on the aforementioned support before the aforementioned adhesive layer is formed.

[0257] As commercially available products of the silicone resin used in the aforementioned addition reaction type silicone adhesive, the following can be given: SD4580PSA, SD4584PSA, SD4585PSA, SD4587LPSA, SD4560PSA, SD4570PSA, SD4600FCPSA, SD4593PSA, DC7651ADHESIVE, DC7652ADHESIVE, LTC-755, LTC-310 (all of Dow Corning Toray Company), KR-3700, KR-3701, X-40-3237-1, X-40-3240, X-40-3291-1, X-40-3229, X-40-3323, X-40-3306, X-40-3270-1 (all of Shin-Etsu Chemical Co., Ltd.), AS-PSA001, AS-PSA002, AS-PSA003, AS-PSA004, AS-PSA005, AS-PSA012, AS-PSA014, PSA-7465 (all of Arakawa Chemical Industries, Ltd.), TSR1512, TSR1516, TSR1521 (all of Momentive Performance Materials Inc.), and the like. However, the present application is not limited to these.

[0258] (Polarizing plate)

[0259] The material and the constitution of the above-mentioned polarizing plate are arbitrary. For example, a stretched polyvinyl alcohol film using iodine as an orienting dye, on which a TAC (triacetyl cellulose) film as a protective film is laminated, is widely utilized as such a polarizing plate.

[0260] In addition, the polarizing plate can have a hard coat layer having substantially no phase difference on the surface, or can be constituted of a layer having a function of anti-glare, low reflection, anti-static electricity, and the like.

[0261] (Touch sensor)

[0262] The above-mentioned touch sensor is a member that grasps a touch point in response to a contact when a user touches an image displayed in a screen with a finger, a stylus, or the like, and according to sensor technology, methods such as an electrostatic capacity type, an impedance film type, a surface wave method using infrared rays or ultrasonic waves, and the like are exemplified.

[0263] Generally, a touch sensor is mounted on a display device such as a liquid crystal display panel, an organic EL, and the like.

[0264] In recent years, there is a tendency to use a base material film in place of a glass substrate, focusing on flexibility.

[0265] A touch sensor film generally has a patterned transparent conductive layer for performing a function of a sensing electrode.

[0266] <Explanation of terms, etc.>

[0267] Generally, "sheet" refers to a thin, flat product having a thickness that is small throughout the length and width, and generally, "film" refers to a thin, flat product having a thickness that is extremely small compared to the length and width, with the maximum thickness being arbitrarily limited, and generally refers to a product supplied in roll form (Japanese Industrial Standards; JIS K 6900). However, the boundary between sheet and film is not definite, and in the present application, the terms are not distinguished, and thus, in the present application, the case where "film" is referred to also includes "sheet", and the case where "sheet" is referred to also includes "film".

[0268] In the present application, in the case where "X to Y" (X, Y are arbitrary numbers) is written, unless otherwise specified, both the meaning of "X or more and Y or less" and the meaning of "preferably more than X" or "preferably less than Y" are included.

[0269] In addition, in the case where "X or more" (X is an arbitrary number) is written, unless otherwise specified, the meaning of "preferably more than X" is included, and in the case where "Y or less" (Y is an arbitrary number) is written, unless otherwise specified, the meaning of "preferably less than Y" is also included.

[0270] Examples

[0271] Hereinafter, the present application will be described more specifically using examples. However, the present application is not limited by the following examples.

[0272] <Method of evaluation>

[0273] (1) Normal peel strength

[0274] The adhesive tape "Polyimide Tape with Silicone Adhesive No. 5413 (manufactured by 3M Company)" was attached to the release surface of the sample film with a width of 5 cm, and the normal peel strength was measured using a peel tester at 180° peeling, 0.3 m / minute in an environment at room temperature (23°C).

[0275] (2) Heat peel strength

[0276] After the adhesive tape "Polyimide Tape with Silicone Adhesive No. 5413 (manufactured by 3M Company)" was adhered to the release surface of the sample film, it was cut to a size of 50 mm x 300 mm, and heat-treated at 100°C for 1 hour in a hot air oven. After that, the sample was taken out, and the peel strength after standing for 1 hour at room temperature (23°C) was measured.

[0277] The peel strength was measured using "EZ Graph" manufactured by Shimadzu Corporation at a tensile speed of 0.3 (m / minute) at room temperature (23°C) at 180° peeling.

[0278] The lower the value of the heat peel force, the better the peel characteristics can be evaluated.

[0279] (3) Residual Adhesion Rate (Evaluation of Transferability of Release Layer by Proxy)

[0280] After the tape with silicone adhesive (3M Company, "No. 5413") was adhered to the release surface of the sample film with a 2 kg rubber roll, it was cut into a 50 mm x 250 mm long state as a measurement sample for the residual adhesion rate. After 1 hour of heat treatment in an oven heated to 100°C, it was cut to 20 mm wide and left to stand for 1 hour under normal temperature and humidity. The adhesive tape peeled from the measurement sample was pressure-bonded to a stainless steel plate (60 mm x 150 mm) on which cleaning was completed with a rubber roll.

[0281] The peel force was measured using "EZ Graph" manufactured by Shimadzu Corporation, under the conditions of a tensile speed of 0.3 (m / minute) and at room temperature (23°C) for 180° peeling.

[0282] Then, the peel force of the evaluation film for which the residual adhesion rate was measured and the peel force of a reference film (a sample obtained by bonding No. 5413 tape to a Nafion tape instead of the sample film) were substituted into the following equation to calculate the residual adhesion rate (%).

[0283] Residual Adhesion Rate (%) = (Peel Force of Transferability Evaluation Film / Peel Force of Reference Film) x 100

[0284] (4) Fluorine Atom Concentration in the Thickness Direction in the Release Layer (Atom %)

[0285] The concentration distribution (ratio) of carbon (C), oxygen (O), silicon (Si), and fluorine (F) atoms in the thickness direction in the release layer of the sample film was measured using GC-IB (gas cluster ion beam) under constant sputtering speed (sputtering condition setting).

[0286] At this time, the setting conditions of XPS were as follows.

[0287] Apparatus: PHI5000 VersaProbe II manufactured by ULVAC PHI

[0288] = Analysis Conditions =

[0289] X-ray Intensity: AlKα / 15 kV · 25 W

[0290] Measurement Range:

[0291] Path Energy: 58.70 eV

[0292] Charging correction: 284.6 eV (C1s)

[0293] = Sputtering conditions =

[0294] Ar-GCIB

[0295] 10 kV, 60 minutes (3-minute intervals, 20 steps)

[0296] The obtained fluorine atom concentration profile (vertical axis: fluorine atom concentration (atom%), horizontal axis: sputtering time (minutes)) was divided into nine equal parts with respect to the total sputtering time, and the fluorine atom concentration (atom%) at each measurement point was determined from the 1st measurement point (sputtering time 0 seconds, release layer surface) to the 10th measurement point (substrate, reaching the base material PET film).

[0297] Then, the ratio (%) of the concentration of fluorine atoms (atom%) at the 2nd measurement point with respect to the concentration of fluorine atoms (atom%) at the 1st measurement point, and the ratio (%) of the average fluorine atom concentration (atom%) at the 6th to 10th measurement points with respect to the concentration of fluorine atoms (atom%) at the 1st measurement point were calculated, and are shown in Table 1.

[0298] <Example 1>

[0299] The following (A) curable organosilicon having a fluorine substituent, the following (C1) organosilicon crosslinking agent, and the following (D1) curing catalyst 1 were mixed to produce a solution a1. After stirring for 1 minute, the following solution b1 ((B) curable organosilicon not containing a fluorine substituent + (D2) curing catalyst 2) was mixed in such a manner that the mass ratio (solution a1 : solution b1) became 1 : 2, and a coating liquid A1 having a solid content concentration of 3.6 mass% was produced.

[0300] Then, the aforementioned coating liquid A1 was coated on one side of a base material film (PET film ("T100-38", thickness 38 μm) manufactured by Mitsubishi Chemical Corporation) using a No. 4 bar, and heat treatment was performed at 150°C for 15 seconds to cure it, and a release film provided with a release layer (sample film) was obtained.

[0301] (Release layer composition)

[0302] Solution a1:

[0303] (A) curable organosilicon having a fluorine substituent

[0304] (Dow Corning Toray Co., Ltd. "3062", 10 mass%, viscosity 10 mm 2 / s) 100 mass parts

[0305] (C1) organosilicon crosslinking agent not containing a fluorine substituent

[0306] (Dow Corning Toray Co., Ltd. "3062A") 0.50 parts by mass

[0307] (D1) Platinum catalyst 1

[0308] (Dow Corning Toray Co., Ltd. "FS XK-3077") 0.50 parts by mass

[0309] Diisopropyl ether / ethyl acetate (3:7)

[0310] Solution b1:

[0311] (B) Curing-type silicone not containing a fluorine-substituted group

[0312] (Kanehara Chemical Industries, Ltd. "KS-847H", solvent type, 30 mass%, containing a crosslinking agent / reaction controller, viscosity 11000 mPa-s (25°C)) 67 parts by mass

[0313] (D2) Platinum catalyst 2 (Kanehara Chemical Industries, Ltd. "CAT-PL-50T") 0.67 parts by mass Diisopropyl ether / ethyl acetate (3:7)

[0314] <Example 2> to <Example 5>

[0315] In Example 1, after solution al was prepared, stirring was performed for 1 minute, and further, a standing time was added so as to be as shown in the table, and otherwise, a release film (sample film) was produced in the same manner as in Example 1.

[0316] <Example 6>

[0317] In Example 1, after solution al was prepared at a solid content concentration of 10 mass%, stirring was performed for 1 minute, and further, a standing time of 15 minutes was added, and thereafter, dilution was performed with a solvent so as to be a solid content concentration of 3.6 mass%, and otherwise, a release film (sample film) was produced in the same manner as in Example 1.

[0318] <Comparative Example 1>

[0319] In Example 1, stirring was not performed at all, and otherwise, a release film (sample film) was produced in the same manner as in Example 1.

[0320] Note that "stirring was not performed at all" means that "after solution al was prepared by mixing (C1) silicone crosslinking agent and (D1) curing catalyst 1, solution bl was immediately mixed without stirring, and coating liquid Al was prepared".

[0321] <Comparative Example 2>

[0322] A release film (sample film) was produced in the same manner as in Example 1, except that (B) the curable silicone not containing a fluorine-substituted group and (D2) the curing catalyst 2 were not mixed in Example 1.

[0323] <Comparative Example 3>

[0324] A release film (sample film) was produced in the same manner as in Example 2, except that (C2) the crosslinking agent having a fluorine-substituted group (Dow Corning Toray Co., Ltd. "3062C") 0.5 parts by mass) was compounded instead of (C1) the silicone crosslinking agent not containing a fluorine-substituted group in Example 2.

[0325] <Comparative Example 4>

[0326] A release film (sample film) was produced in the same manner as in Example 1, except that (C2) the crosslinking agent having a fluorine-substituted group (Dow Corning Toray Co., Ltd. "3062C") 0.5 parts by mass) was compounded instead of (C1) the silicone crosslinking agent not containing a fluorine-substituted group in Comparative Example 2.

[0327] <Comparative Example 5>

[0328] For TPR6600 (manufactured by Momentive) as the curable silicone not containing a fluorine-substituted group (containing a crosslinking agent not containing a fluorine-substituted group): 100 parts by mass, LC600 (manufactured by Momentive) as the curing catalyst: 3 parts by mass were compounded and mixed to produce a solution b2.

[0329] For BY24-900 (manufactured by Dow Corning Toray Co., Ltd.) as the curable silicone having a fluorine-substituted group (including a crosslinking agent): 100 parts by mass, NC-25 (manufactured by Dow Corning Toray Co., Ltd.) as the curing catalyst: 0.5 parts by mass were compounded and mixed to produce a solution a2.

[0330] For the solution a2 containing the aforementioned curable silicone having a fluorine-substituted group: 100 parts by mass, the solution b2 containing the aforementioned curable silicone not containing a fluorine-substituted group: 100 parts by mass were compounded and mixed, and a solvent in which n-heptane and methyl isobutyl ketone were mixed at a weight ratio of 1:1 was added to dissolve the polymer components, to produce a coating liquid A2 having a solid content concentration of 3.0% by mass.

[0331] Note that the solution a2 and the solution b2 were not stirred at all before being mixed.

[0332] "Complete non-stirring" here means "immediately after solution a2 is prepared, solution b2 is mixed without stirring to prepare coating liquid A2".

[0333] Then, the aforementioned coating liquid A2 was coated on one side of a base film (PET film ("T100-38", thickness 38 μm) manufactured by Mitsubishi Chemical Corporation) using a No. 10 bar, and heat-treated at 120°C for 120 seconds to cure it, thereby obtaining a release film (sample film) provided with a release layer.

[0334] <Comparative Example 6>

[0335] BY24-900 (manufactured by Dow Corning Toray Co., Ltd.) as a curable organosilicon (including a cross-linking agent) having a fluorine substituent: 100 parts by mass, and NC-25 (manufactured by Dow Corning Toray Co., Ltd.) as a curing catalyst: 0.5 parts by mass were mixed to prepare solution a2.

[0336] A solvent in which n-heptane and methyl isobutyl ketone were mixed at a weight ratio of 1 : 1 was added to the aforementioned solution a2 to dissolve the polymer component, and coating liquid A3 having a solid content concentration of 3.6% by mass was prepared.

[0337] Then, the aforementioned coating liquid A3 was coated on one side of a base film (PET film ("T100-38", thickness 38 μm) manufactured by Mitsubishi Chemical Corporation) using a No. 4 bar, and heat-treated at 120°C for 120 seconds to cure it, thereby obtaining a release film (sample film) provided with a release layer.

[0338] [Table 1]

[0339]

[0340] [Table 2]

[0341]

[0342] <Investigation>

[0343] As is clear from the results of the above examples and the experiments conducted by the present inventors so far, when the release layer formed on at least one side of the base film is cured from a release layer composition containing (A) a curable organosilicon having a fluorine substituent, (B) a curable organosilicon not containing a fluorine substituent, and (D) a curing catalyst, it has excellent easy release properties in that it is easy to release from the organosilicon adhesive layer even if the amount of fluorinated organosilicon is reduced.

[0344] Moreover, if the common points of such a release layer are investigated, it can be found that the concentration distribution of fluorine atoms in the thickness direction in the release layer is characterized in that the fluorine is concentrated on the surface of the release layer.

[0345] More specifically, it can be found that, in the fluorine atom concentration distribution (vertical axis: fluorine atom concentration (atom%), horizontal axis: sputtering time (minutes)) obtained in the above-described example, when the total sputtering time is divided into nine equal parts, and the 1st measurement point (sputtering time 0), the 2nd measurement point,... the 10th measurement point are determined, the fluorine atom concentration (atom%) in the 2nd to 10th measurement points is 80.0% or less of the fluorine atom concentration (atom%) in the 1st measurement point (sputtering time 0).

[0346] Furthermore, it can be found that, if the average fluorine atom concentration (atom%) in the 6th to 10th measurement points is higher than 2.2% of the fluorine atom concentration (atom%) in the 1st measurement point (sputtering time 0), a further excellent effect, i.e., an excellent easy release property that the release layer is easily released from the silicone adhesive layer even if the amount of fluorinated silicone is reduced, can be obtained.

[0347] On the other hand, in the method of forming the above-described release layer, the following can be found.

[0348] It is confirmed that, in the case where a solution in which two kinds of (A) a curable silicone having a fluorine substituent and (B) a curable silicone not containing a fluorine substituent are mixed is applied to a film and dried, (A) a curable silicone having a fluorine substituent is easily segregated to the surface (air interface) side for higher hydrophobicity.

[0349] On the other hand, as for the silicone crosslinking agent and the catalyst used in combination, they do not have a high hydrophobicity equivalent to that of (A) a curable silicone having a fluorine substituent from their molecular structures. Therefore, they are not uniformly dispersed in the film, and a release layer having a good cured state cannot be obtained, or (B) a curable silicone not containing a fluorine substituent cannot be mixed in a large amount.

[0350] Therefore, in the present application, it can be found that, first, a "pre-treatment" in which (A) a curable silicone having a fluorine substituent, (C) a silicone crosslinking agent, and (D) a curing catalyst are mixed, stirred, and / or allowed to stand to react is performed, a pre-treatment composition obtained in the pre-treatment is mixed with (B) a curable silicone not having a fluorine substituent to prepare a release layer composition, and as a result, even if (C1) a silicone crosslinking agent not having a fluorine substituent is used, uniform dispersion can be achieved, and an easy release property that the release layer is easily released from a silicone adhesive can be achieved.

[0351] The mechanism is not clear in detail, but it is presumed that a moderate entanglement (pre-crosslinking) is induced in the compounded solution with the passage of time after the compounded solution is prepared. At the same time, it is presumed that (A) the curable silicone having a fluorine substituent is present more on the surface (air interface) side.

[0352] As a result, it is presumed that even after being applied to a film, the fluorine substituent is more biased toward the vicinity of the surface of the release layer, and thus a coating film having a light peeling property can be formed.

[0353] Further, more (B) curable silicone not containing a fluorine substituent can be mixed, and thus the total amount of the fluorine atom content in the coating film can be further reduced during the process of forming the release layer coating film, and the release property can be efficiently exhibited.

Claims

1. A release film characterized by comprising: A release film which is provided with a release layer on at least one side of a base film, the release layer being cured from a release layer composition containing (A) a curable organosilicon having a fluorine substituent, (B) a curable organosilicon not containing a fluorine substituent, (C1) an organosilicon crosslinking agent not containing a fluorine substituent, and (D) a curing catalyst, The mass ratio of (A) the curable organosilicon having a fluorine substituent to (B) the curable organosilicon not containing a fluorine substituent is 1:50 to 10:1, The content of (C1) the organosilicon crosslinking agent not containing a fluorine substituent is 0.1 to 50 parts by mass relative to 100 parts by mass of the total of (A) the curable organosilicon having a fluorine substituent and (B) the curable organosilicon not containing a fluorine substituent, In the concentration distribution of fluorine atoms in the thickness direction within the release layer, the fluorine atoms are biased toward the surface of the release layer, and the fluorine atom concentration at the surface of the release layer is 39.0 atomic concentration % or more.

2. The release film according to claim 1, wherein XPS, i.e., X-ray photoelectron spectroscopy, using GC-IB, i.e., gas cluster ion beam, measures the concentration distribution of fluorine atoms in the thickness direction within the release layer at a constant sputtering rate, divides the obtained fluorine atom concentration distribution into nine equal parts by total sputtering time, and determines the 1st measurement point, the 2nd measurement point,..., and the 10th measurement point, The fluorine atom concentration in atomic % in the 2nd measurement point to the 10th measurement point is 80.0% or less of the fluorine atom concentration in atomic % in the 1st measurement point, In the fluorine atom concentration distribution, the vertical axis is the fluorine atom concentration in atomic %, and the horizontal axis is the sputtering time in minutes, and the sputtering time of the 1st measurement point is 0.

3. The release film of claim 1, wherein XPS, i.e., X-ray photoelectron spectroscopy, using GC-IB, i.e., gas cluster ion beam, measures the concentration distribution of fluorine atoms in the thickness direction within the release layer at a constant sputtering rate, divides the obtained fluorine atom concentration distribution into nine equal parts by total sputtering time, and determines the 1st measurement point, the 2nd measurement point,..., and the 10th measurement point, The average fluorine atom concentration in atomic % in the 6th measurement point to the 10th measurement point is higher than the fluorine atom concentration in atomic % in the 1st measurement point by 2.2% or more, In the fluorine atom concentration distribution, the vertical axis is the fluorine atom concentration in atomic %, and the horizontal axis is the sputtering time in minutes, and the sputtering time of the 1st measurement point is 0.

4. The release film of claim 1, wherein, The fluorine atom content in the release layer is 500 parts by mass or more and 800,000 parts by mass or less.

5. The release film of claim 1, wherein, (B) The curable organosilicon not containing a fluorine substituent is a solvent-type curable organosilicon.

6. The release film of claim 1, wherein, The normal-state peeling force of the release layer is 75 mN / cm or less, and the residual adhesion rate is 80% or more.

7. The release film of claim 1, wherein, The heating peeling force of the release layer is 100 mN / cm or less.

8. A method of manufacturing a release film according to claim 1, characterized by, (A) The curable organosilicon having a fluorine substituent, (C1) the organosilicon crosslinking agent not containing a fluorine substituent, and (D) the curing catalyst are mixed, followed by stirring and / or standing, and then mixed with (B) the curable organosilicon not having a fluorine substituent to prepare a release layer composition, and the release layer composition is applied to at least one side of a base film.

9. A method of manufacturing the release film according to claim 1, characterized by, A release layer composition is prepared by mixing (A) a curable silicone having a fluorine substituent, (C1) a silicone crosslinking agent not containing a fluorine substituent, and (D) a curing catalyst, followed by stirring and / or standing for 1 minute or more, and then mixing with (B) a curable silicone not having a fluorine substituent, and the release layer composition is applied to at least one side of a base film.

10. A film laminate comprising: the release film according to any one of claims 1 to 7 attached to a laminate film having a functional layer via a silicone adhesive layer.

11. The film laminate according to claim 10, wherein The laminate film having a functional layer is a laminate film provided with a crosslinked resin layer on at least one side of a base film.

12. The film stack of claim 11, wherein, The crosslinked resin layer contains an electrically conductive polymer and a binder polymer.

13. The film stack of claim 10, wherein, The laminate film having a functional layer is a release film provided with another release layer on one side of a base film.

14. The film stack of claim 13, wherein, The other release layer comprises a structure provided with a first layer and a second layer in this order, the first layer is formed of a silicone composition containing (B) a curable silicone not containing a fluorine substituent as a main component, and the second layer contains a component having a fluorine substituent.

15. The film stack of claim 13, wherein, The other release layer is formed of a silicone composition containing (A) a curable silicone containing a fluorine substituent as a main component.

16. The film stack of claim 13, wherein, The other release layer is formed of a silicone composition containing (B) a curable silicone not containing a fluorine substituent as a main component.

17. The film laminate according to any one of claims 10 to 16, characterized in that, Attachment to a member for vehicle use.

18. A method of using a film laminate, characterized by, The film laminate comprises: a light release film according to any one of claims 1 to 7 laminated on one side of a silicone adhesive layer formed of a silicone adhesive, and a heavy release film having a higher release strength than the light release film laminated on the other side of the silicone adhesive layer, After the light release film is peeled off, the exposed surface of the silicone adhesive layer is attached to an adherend, and after the silicone adhesive layer is cured, the heavy release film is peeled off.

19. The method of using a thin film stack of claim 18, wherein, The adherend is an optical member.

20. The method of using a thin film stack of claim 19, wherein, The optical member is a polarizing plate or a touch sensor.

21. The method of using a thin film stack of claim 19 or 20, wherein, The optical member is an optical member for vehicle use.

Images