JP2024006000A - Release layer composition, release film and method for producing them, and film laminate and method for using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a novel release film that facilitates detachment from a silicone adhesive layer, exhibits superior light detachability, and also demonstrates less tendency of migration.

SOLUTION: A release layer composition comprises (A) a crosslinkable fluorine-containing polymer, (E) a polymer free of fluorine substituents, and (X) a fluorine segregation promoter.

SELECTED DRAWING: None

COPYRIGHT: (C)2024,JPO&INPIT

Description

The present invention relates to a release layer composition, a release film, a method for producing these, and a film laminate and a method for using the same.

In recent years, more and more cars are equipped with liquid crystal panels. In such in-vehicle applications, panels are often exposed to high or low temperatures for long periods of time, and the adhesives that bond panel components together are also required to have a high degree of weather resistance and heat resistance. As a pressure-sensitive adhesive suitable for this purpose, silicone pressure-sensitive adhesives mainly composed of silicone are attracting attention.

Silicone adhesives have excellent heat resistance, chemical resistance, and transparency, and exhibit adhesion to silicone rubber, fluororesins, metals, etc. that are difficult to adhere to with regular adhesives, and also have excellent re-adhesion properties. It has characteristics such as:
Silicone adhesives are used in tape (film) form as an adhesive layer, and are usually stored with one or both sides covered with a release film before use. It is common to use it by peeling off the mold film.

As a release film used for this type of application, a silicone release film formed by coating a base film with a silicone release agent is often used.
However, when such a silicone release film is coated with a silicone adhesive, the chemical structure of the release agent and the adhesive is similar, so the adhesive and release film strongly adhere to each other and cannot be peeled off. It tended to be difficult. Therefore, for the purpose of lowering the peeling force value for silicone adhesives (improving easy peelability), efforts have been made to introduce fluorine into silicone release agents. For example, Patent Document 1 proposes a fluorinated silicone material having a fluorine-containing organic group for the purpose of exhibiting releasability to a silicone adhesive.

Japanese Patent Application Publication No. 2011-201035

A crosslinkable fluorosilicone polymer as disclosed in Patent Document 1 is a substance with high chemical stability and low toxicity. However, in order to easily release a release film coated with a crosslinkable fluorosilicone polymer, it is often necessary to increase the coating thickness, which is disadvantageous in terms of cost. Furthermore, silicone release agents that use fluorosilicone polymers may migrate to adhesives, causing a decrease in the adhesive strength of the adhesive or contaminating the adherend to which the adhesive is attached. Ta.

Therefore, the present invention relates to a silicone release film formed using fluorinated silicone, and relates to a new release layer composition that provides easy release properties to a silicone adhesive layer and has low migration properties. It is an object of the present invention to provide a mold film, a method for producing these, a film laminate including the release film, and a method for using the same.

As a result of intensive studies, the inventors of the present invention found that the above-mentioned problems can be solved by using a release layer composition and a release film having a specific configuration, and completed the present invention as described below.
That is, the present invention provides the following [1] to [24].
[1] A release layer composition comprising (A) a crosslinkable fluorine-containing polymer, (E) a polymer containing no fluorine substituents, and (X) a fluorine segregation promoter.
[2] The separating agent according to [1] above, wherein the (X) fluorine segregation promoter is a pre-treated composition in which a crosslinking reaction has been carried out in advance in a compounded solution containing (A) a crosslinkable fluorine-containing polymer. Mold layer composition.
[3] A release film comprising a base film and a release layer provided on at least one side of the base film, wherein the release layer is cured with the release layer composition according to [1] above. A release film made of
[4] The release film according to the above [3], wherein the fluorine atom content in the release layer is from 3,000 mol ppm to 900,000 mol ppm.
[5] [3] above, wherein the fluorine atom concentration distribution ratio t _d (t1 [75%]/t2 [50%]) calculated by the following method in the thickness direction of the release layer is 1 to 24%. The release film described in .
Calculation method of fluorine atomic concentration distribution ratio: Based on the fluorine atomic ratio at the outermost surface (sputtering time 0), the sputtering time (t1 [75%]) required for the fluorine atomic ratio to decrease to 75% of the outermost surface, The ratio t _d (t1 [75%]/t2 [50%]) to the sputtering time (t2 [50%]) at which the fluorine atomic ratio decreases to 50% of the outermost surface is calculated in percentage (%).
[6] The release film according to [3] above, wherein the release layer has a heat peeling force of 65 mN/cm or less and a residual adhesion rate of 85% or more.
[7] The method for producing a release layer composition according to [1] above, wherein (A) a crosslinkable fluorine-containing polymer, (E) a polymer not containing a fluorine substituent, and (X) a fluorine segregation promoter are mixed. .
[8] The (X) fluorine segregation promoter is obtained by mixing (A) a crosslinkable fluorine-containing polymer, (B) a silicone crosslinking agent, and (C) a curing catalyst, and then stirring and/or allowing it to stand still. The method for producing the release layer composition according to [7] above.
[9] The method for producing a release layer composition according to the above [8], wherein the stirring and/or standing is performed for 10 seconds or more.
[10] The method for producing a release layer composition according to [8] above, wherein a silicone crosslinking agent containing no fluorine substituents is used as the silicone crosslinking agent (B).
[11] A release film in which a release layer composition obtained by the method for producing a release layer composition according to any one of [7] to [10] above is applied to at least one side of a base film. manufacturing method.
[12] The release film according to any one of [3] to [6] above, a silicone adhesive layer, and a laminate film having a functional layer, the release film and the laminate film having a functional layer. A film laminate made of films bonded together via a silicone adhesive layer.
[13] The film laminate according to [12] above, wherein the laminate film having a functional layer includes a base film and a crosslinked resin layer provided on at least one side of the base film.
[14] The film laminate according to [13] above, wherein the crosslinked resin layer is formed from a crosslinked resin layer composition containing a conductive polymer and a binder polymer.
[15] The film laminate according to the above [13], wherein the crosslinked resin layer is an easily adhesive layer to the silicone adhesive layer.
[16] The laminated film having a functional layer includes a base film and another release layer provided on one side of the base film, according to any one of [12] to [15] above. Film laminate.
[17] The other release layer includes (E) a first layer formed from a silicone composition containing as a main component a polymer not containing a fluorine substituent, and a second layer containing a component having a fluorine substituent. The film laminate according to [16] above, which has a structure including layers in sequence.
[18] The film laminate according to [16] above, wherein the other release layer is formed from a silicone composition containing (A) a crosslinkable fluorine-containing polymer as a main component.
[19] The film laminate according to [16] above, wherein the other release layer is formed from a silicone composition containing as a main component (E) a polymer that does not contain fluorine substituents.
[20] The release film according to any one of [3] to [6] above, a silicone adhesive layer, and a resin film; A film laminate made by directly bonding resin films.
[21] The release film according to any one of [3] to [6] above, a silicone adhesive layer, and a heavy release film, the release film being placed on one side of the silicone adhesive layer. and a method of using a film laminate in which the heavy release film is laminated on the other side of the silicone adhesive layer, the heavy release film having a higher peel strength than the release film, A method for using a film laminate, which comprises peeling off a mold film, adhering the exposed surface of the silicone adhesive layer to an adherend, and then peeling off the heavy release film.
[22] The method of using the film laminate according to [21] above, wherein the adherend is an optical member.
[23] The method of using the film laminate according to [22] above, wherein the optical member is a polarizing plate or a touch sensor.
[24] The method of using the film laminate according to [22] above, wherein the optical member is an in-vehicle optical member.

The release layer composition and release film proposed by the present invention include (A) a crosslinkable fluorine-containing polymer, (E) a polymer that does not contain a fluorine substituent, and (X) promoting fluorine segregation for forming the release layer. By including the agent, easy releasability and low migration properties can be imparted to the silicone adhesive layer. Moreover, according to the method for producing a release film proposed by the present invention, such a release layer composition and release film can be efficiently produced.

2 is a profile showing the F concentration in the release layer of the release film of Example 1. 3 is a profile showing the F concentration in the release layer of the release film of Example 5. 3 is a profile showing the F concentration in the release layer of the release film of Example 6. 2 is a profile showing the F concentration in the release layer of the release film of Comparative Example 1. 3 is a profile showing the F concentration in the release layer of the release film of Comparative Example 2. 3 is a profile showing the F concentration in the release layer of the release film of Comparative Example 3.

Next, the present invention will be described based on embodiments. However, the present invention is not limited to the embodiment described below.

<Release layer composition>
The composition of the present invention is a composition for forming a release layer (hereinafter referred to as "release layer composition"), and includes at least (A) a crosslinkable fluorine-containing polymer.

((A) Crosslinkable fluorine-containing polymer)
By containing (A) a crosslinkable fluorine-containing polymer, the release layer composition of the present invention can impart stable and easy releasability to silicone adhesives.
(A) The crosslinkable fluorine-containing polymer is not particularly limited as long as it contains fluorine, but among them, (A') crosslinkable fluorine-containing silicone polymer is preferred.
In addition, "Silicone" has a skeleton (siloxane skeleton) of a siloxane bond (≡Si-O-Si≡) consisting of silicon and oxygen, and has methyl (-CH ₃ ) as its main component in the silicon (Si). It is a polyorganosiloxane with organic groups bonded to it.
Moreover, "crosslinkable fluorine-containing silicone polymer" is a silicone that can be cured by crosslinking reaction by heating or light irradiation (ultraviolet rays).

The above-mentioned "fluorine-containing silicone polymer" refers to a silicone polymer having a substituent containing a fluorine atom (hereinafter sometimes referred to as "fluorine substituent").
The substituent containing a fluorine atom (fluorine substituent) is not particularly limited as long as the substituent contains a fluorine atom. Specifically, fluorine group (fluorine atom), trifluoromethyl group, pentafluoroethyl group, 2,2-trifluoroethyl group, 1H,1H-heptafluorobutyl group, 2H-hexafluoroisopropyl group, perfluoro- Examples include t-butyl group and perfluorohexyl group. Further, it may be a monovalent hydrocarbon group having an ether bond and a fluorine atom, and may be a fluorine substituent having a fluorine-containing polyalkylene oxide structure such as a fluorine-containing polypropylene oxide structure. However, it is not limited to these.
Moreover, as a component having a fluorine substituent, a polyorganosiloxane containing a fluorine substituent in the side chain portion of the polymer skeleton can be mentioned.
Among the functional groups directly bonded to Si constituting the siloxane skeleton (hereinafter sometimes referred to as "R"), the ratio of fluorine substituents is, for example, 5 to 35 mol%, preferably 10 to 30 mol%. It is.

In the crosslinkable fluorine-containing silicone polymer (A'), examples of R directly bonded to Si include unsubstituted or substituted monovalent hydrocarbon groups. The monovalent hydrocarbon group may be a monovalent hydrocarbon group substituted with a fluorine atom (ie, a fluorine substituent), or may have an ether bond. Further, as described above, the fluorine substituent may have an ether bond. Furthermore, as described later, it may be a monovalent hydrocarbon group having an alkenyl group. The monovalent hydrocarbon group has, for example, 1 to 15 carbon atoms, preferably 1 to 10 carbon atoms.

In the present invention, it is preferable to use a curable silicone that is cured by a hydrosilylation addition reaction, especially in "(A') crosslinkable fluorine-containing silicone polymer" from the viewpoint of material availability.
Therefore, the crosslinkable fluorine-containing silicone polymer (A') preferably has at least two alkenyl groups, and is preferably crosslinked by the alkenyl groups. Here, examples of the alkenyl group include vinyl group (ethenyl group), allyl group (2-propenyl group), butenyl group, pentenyl group, hexenyl group, heptenyl group, octenyl group, decenyl group, etc. Among these, a vinyl group is preferred. These alkenyl groups are preferably silicon-bonded alkenyl groups that directly bond to Si constituting the siloxane skeleton.
Among the functional groups directly bonded to Si constituting the siloxane skeleton, the ratio of alkenyl groups is, for example, 0.2 to 10 mol%, preferably 0.5 to 5 mol%.

Moreover, examples of the monovalent hydrocarbon group for R include an alkyl group, an aryl group, and the like, in addition to the above-mentioned alkenyl group and fluorine substituent. Examples of the alkyl group include alkyl groups such as methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, t-butyl group, isobutyl group, and sec-butyl group. Furthermore, examples of the aryl group include a phenyl group and a tolyl group.
Further, as mentioned above, it is preferable that the main group is a methyl group, for example, 50 mol% or more of R is a methyl group, preferably 55 to 94 mol%, more preferably 65 to 89 mol%.

(A') Specific examples of crosslinkable fluorine-containing silicone polymers include KP-911, X-70-201S, and X-41-3035 manufactured by Shin-Etsu Chemical Co., Ltd.; FS1265 manufactured by Dow Corning Toray Co., Ltd. -300CS, FS1265-1000CS, FS1265-10000CS, BY24-900, BY24-903, 3062, Q2-7785, SYL-OFF 7792, SYL-OFF 7795 and the like. However, it is not limited to these.

(A') The crosslinkable fluorine-containing silicone polymer may be of a solvent type or a non-solvent type, or may be a mixture thereof. (A') Two or more types of crosslinkable fluorine-containing silicone polymers may be used in combination for easy release.

Here, "solvent-free curable silicone" refers to a silicone with a viscosity that allows it to be coated without diluting it with a solvent, and is composed of short polysiloxane chains and has a relatively low molecular weight.
The viscosity of the solvent-free curable silicone is preferably such that the kinematic viscosity at 25° C. when made into an 85% by mass n-heptane solution is 30,000 mm ² /s or less, particularly 20,000 mm ² /s or less. More preferably, it is 10,000 mm ² /s or less. Further, the speed is preferably 100 mm ² /s or more, and more preferably 500 mm ² /s or more.

On the other hand, "solvent-curable silicone" refers to a silicone with a relatively high molecular weight and has such a high viscosity that it cannot be coated without being diluted with a solvent. Therefore, solvent-curable silicones generally have a higher weight average molecular weight or viscosity than solvent-free cure silicones. The viscosity here refers to the viscosity measured under the same conditions, for example, the viscosity at 25° C. when dissolved in an organic solvent such as n-heptane or diisopropyl ether at the same concentration.

The viscosity of the solvent-curable silicone at 25° C. is preferably 0.1 mm ² /s or more, more preferably 0.5 mm ² /s or more, especially 1. It is more preferably 0 mm ² /s or more, more preferably 300 mm ² /s or less, even more preferably 200 mm ² /s or less, even more preferably 100 mm ² /s or less. When the solvent-curable silicone has a high viscosity, its adhesion to the base film tends to increase.
As mentioned above, "solvent-free curable silicone" is a general term for silicones with low viscosity, and does not necessarily have to be solvent-free, but can be diluted with a solvent and added to the release layer composition. You may. Similarly, "solvent-curable silicone" does not necessarily need to be diluted with a solvent and added to the composition.

(A') The fluorine atom content (atomic fraction) of the crosslinkable fluorine-containing silicone polymer is generally several thousand ppm (less than 1% of the total number of atoms in the "crosslinkable fluorine-containing silicone polymer") to several thousand ppm. It is about 100,000 ppm (several tens of percent of the total number of atoms in the "crosslinkable fluorine-containing silicone polymer").

The release layer composition of the present invention contains (A) a crosslinkable fluorine-containing polymer, (E) a polymer that does not contain a fluorine substituent, and (X) a fluorine segregation promoter, so that it is light to the silicone adhesive layer. It has releasability and can realize low migration properties, and for example, can increase the residual adhesive strength of the adhesive after peeling off the release sheet.
Although the principle is not clear, (A) the crosslinkable fluorine-containing polymer contains (X) the fluorine segregation promoter, so that the polymer component containing fluorine atoms is unevenly distributed, and the highly hydrophobic component is concentrated near the surface. It is presumed that this is because it tends to be unevenly distributed, and that unevenly distributed state is stably maintained by appropriate crosslinking or the like.

Furthermore, it is preferable to use a combination of at least two or more crosslinkable fluorine-containing polymers (A) that differ in at least one of the ratio of fluorine substituents, the structure of fluorine substituents, and viscosity or weight average molecular weight. In this way, by combining crosslinkable fluorine-containing polymers with different structures or physical properties, components with different releasability and crosslinkability are mixed in the composition, making it easier to ensure easy releasability and low migration.

((E) Polymer containing no fluorine substituents)
The release layer composition contains (E) a polymer that does not contain fluorine substituents. In the present invention, among these, (E') a silicone polymer that does not contain a fluorine substituent is preferred.
(E') The silicone polymer containing no fluorine substituents preferably has a polyorganosiloxane structure, and the functional group R directly bonded to Si constituting the siloxane skeleton is a monovalent hydrocarbon group. Examples of the monovalent hydrocarbon group include an alkyl group, an aryl group, and an alkenyl group. Examples of the alkyl group include alkyl groups such as methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, t-butyl group, isobutyl group, and sec-butyl group. Furthermore, examples of the aryl group include a phenyl group and a tolyl group. R is preferably mainly composed of methyl groups, for example, 50 mol% or more of R is preferably methyl groups, preferably 55 to 94 mol%, more preferably 65 to 89 mol%.
(E') The silicone polymer that does not contain a fluorine substituent may or may not have crosslinking properties, and if it has crosslinking properties, it may have two or more alkenyl groups as the functional group R. You may do so. Further, it may have the same structure as the crosslinkable fluorine-containing silicone polymer (A') except that it does not contain fluorine.
Furthermore, (E') the silicone polymer not containing a fluorine substituent may be of a solvent type or a non-solvent type, or may be a mixture thereof. Among these, from the viewpoint of stably obtaining easy releasability to a silicone pressure-sensitive adhesive, the silicone polymer (E') not containing a fluorine substituent is preferably a solvent-curable silicone.
Here, "not containing fluorine substituents" means that the amount of fluorine substituents is not large enough to clearly show easy releasability to silicone adhesives, and (A') crosslinkable fluorine-containing silicone The amount of fluorine substituents may be one-half or less of that of the polymer.

(E') Specific examples of silicone polymers that do not contain fluorine substituents include KNS-3051, KNS-320A, KNS-316, KNS-3002, KNS-3300, and X-62 manufactured by Shin-Etsu Chemical Co., Ltd. -1387, KS-837, -62-2825, X-62-9201-A, X-62-9201B, KM3951, KM-768, X-52-6015, KF-2005, -62-7028-B, X-62-7052, X-62-7622, X-62-7660, LTC1063L, LTC1036M, LTC1056L, SRX357, SRX211, SRX345, SRX370, LTC300B, LTC310, LTC355A, LTC759, LTC755, LTC750A, LTC752, LTC761, LTC856, LT Examples include C851. However, it is not limited to these.

Further, a heavy release additive may be added to the silicone polymer (E') that does not contain a fluorine substituent; examples thereof include KS-3800 manufactured by Shin-Etsu Chemical Co., Ltd.; manufactured by Dow Corning Toray Co., Ltd. Examples include SD7292 and BY24-4980.

(E') The silicone polymer containing no fluorine substituents may be used alone, or two or more types having different reactive functional groups and viscosities may be used as a mixture.
By mixing two or more types of silicone polymers that do not contain fluorine substituents, it is possible to adjust the curing reaction, adjust the viscosity of the coating solution, and further improve the wettability and reactivity. At that time, solvent-free silicones may be mixed together, solvent-based silicones may be mixed together, or solvent-free silicones and solvent-based silicones may be mixed together.
Note that the solvent-based curable silicone and the solvent-free curable silicone are as described above except that they do not contain fluorine substituents, and the preferred viscosity range of each is also the same as the above-mentioned range.
Further, the weight average molecular weight of the silicone polymer (E') not containing a fluorine substituent is preferably in the range of 10,000 to 10,000,000, more preferably 50,000 to 5,000,000, More preferably, it is 100,000 to 2,000,000. By using a curable silicone with a weight average molecular weight in the above range, the segregation of (A') the crosslinkable fluorine-containing silicone polymer and (X) the fluorine segregation promoter to the surface of the release layer is promoted, and the Easy releasability can be stably obtained.

The content of the (E) fluorine substituent-free polymer in the present mold release layer composition is not particularly limited as long as it does not impair the effects of the present invention, but per 100 parts by mass of the present mold release layer composition, for example, The amount may be 99 parts by weight or less, preferably 10 to 80 parts by weight.

((X) Fluorine segregation accelerator)
(X) Fluorine segregation promoter comprises (A) a crosslinkable fluorine-containing polymer, (B) a silicone crosslinking agent described below, and (C) a curing catalyst described below.
The preparation method involves mixing (A) a crosslinkable fluorine-containing polymer, (B) a silicone crosslinking agent, and (C) a curing catalyst, and then stirring and/or allowing it to stand (that is, leaving it for a while). "Processing" is carried out. In this way, (X) the fluorine segregation promoter can be produced by allowing the crosslinking reaction (also referred to as "pre-crosslinking") to proceed in the mixed solution at room temperature. That is, (X) the fluorine segregation promoter is a composition (pretreatment composition) containing (A) a crosslinked product of a crosslinkable fluorine-containing polymer, preferably a crosslinked product crosslinked with (B) a silicone crosslinking agent. .
At this time, the above-mentioned "stirring and/or standing", that is, "pretreatment" may be any method that involves the passage of time to allow the crosslinking reaction to proceed, and may be other means such as shaking. Further, the pretreatment time such as stirring and/or standing still is preferably performed for 10 seconds or more, more preferably 1 minute or more, especially 3 minutes or more, especially 5 minutes or more, and especially 15 minutes or more. is particularly preferred. There is no particular limit to the upper limit of the pre-processing time. From the viewpoint of solvent volatilization and workability, it is preferably within one week, more preferably within three days, and particularly preferably within one day.
Further, the temperature of the liquid mixture in the pretreatment is not particularly limited, but is, for example, about 5 to 50°C, preferably about 10 to 30°C.

By using (X) a fluorine segregation promoter in a state in which pre-crosslinking has progressed appropriately through pre-treatment, the crosslinkable fluorine-containing polymer (A) becomes the component (A) after being applied to the base film. The fluorine substituents are likely to be unevenly distributed on the surface of the release layer, ensuring easy releasability. Further, crosslinking becomes sufficiently easy to proceed, the fluorine substituents of component (A) unevenly distributed on the surface are stably retained, and low migration properties are also easily ensured.
The pretreatment may be performed with the pretreatment composition diluted with an organic solvent, or may not be diluted with an organic solvent. The solid content concentration of the pretreatment composition is, for example, 1 to 100% by weight, preferably about 3 to 50% by weight, and more preferably about 5 to 20% by weight.
In addition, in the preparation of (X) the fluorine segregation promoter, it is preferable to use (A') a crosslinkable fluorine-containing silicone polymer as the (A) crosslinkable fluorine-containing polymer, since the effects of the present invention are achieved.

(Blending ratio)
In the release layer composition, the mass ratio of (A) the crosslinkable fluorine-containing polymer and (X) the fluorine segregation promoter is preferably 1:50 to 1000:1, particularly 1:20 to 200:1. The ratio is more preferably 1:10 to 50:1, and even more preferably 1:5 to 20:1.
Note that, although not particularly limited, a solvent-curable silicone is used as the (A) component (first (A) component) used to obtain the (A) component (second (A) component). As component (A), a solvent-free curable silicone may be used.
Further, the ratio of fluorine substituents in component (X) is preferably higher than, for example, the ratio of fluorine substituents in component (A) (second component (A)). In that case, the difference in ratio may be, for example, about 1 to 15 mol%, preferably about 2 to 12 mol%, and more preferably about 4 to 10 mol%.
In addition, when preparing component (X), if component (A) (first component (A)) is a solvent-curable silicone or the ratio of fluorine substituents is increased, component (A) becomes crosslinked. However, by pre-crosslinking through pre-treatment, it is properly crosslinked, and by using the component (X), it becomes easier to achieve both low releasability and low migration properties of the release layer composition.

((B) Silicone crosslinking agent)
The release layer composition preferably contains (B) a silicone crosslinking agent in addition to the above-mentioned (A) crosslinkable fluorine-containing polymer. Note that component (B) may be added directly to the release layer composition, or may be added to the release layer composition as a component constituting the (X) fluorine segregation promoter, and it may be added by both methods. may be done.
Here, the "crosslinking agent" is a compound that connects polymers such as (A) crosslinkable fluorine-containing polymer, and is, for example, a compound that can connect two or more molecules through a chemical covalent bond. In addition, when (A') a crosslinkable fluorine-containing silicone polymer is used as the crosslinkable fluorine-containing polymer (A), it is a compound that connects silicone polymers together.

As the silicone crosslinking agent, (B1) a silicone crosslinking agent that does not contain a fluorine substituent (also referred to as a "non-fluorinated silicone crosslinking agent"), (B2) a silicone crosslinking agent that contains a fluorine substituent (a "fluorinated silicone crosslinking agent") ).
In the present invention, there is no particular restriction as to whether to use (B1) a non-fluorinated silicone crosslinking agent or (B2) a fluorinated silicone crosslinking agent. It is particularly preferable to use (B1) a non-fluorinated silicone crosslinking agent from the viewpoint of increasing uneven distribution, increasing easy releasability, and ensuring the effect of increasing residual adhesive strength. (B1) The non-fluorinated silicone crosslinking agent may be used alone, or may be used in combination with (B2) the fluorinated silicone crosslinking agent.

((B1) Non-fluorinated silicone crosslinking agent)
(B1) The non-fluorinated silicone crosslinking agent is preferably a crosslinking agent having a siloxane skeleton, and has a silicon-bonded hydrogen atom (SiH group) in the side chain and/or terminal of the main chain consisting of a siloxane bond. Preferably. More specifically, it is represented by the following general formula (1), and there are at least 2, preferably 3 or more (usually about 3 to 200), more preferably 3 to 100, in one molecule, especially Those having 3 to 50 silicon-bonded hydrogen atoms (SiH groups) are preferred.

R _b H _c SiO _(4-b-c)/2 (1)

In formula (1), R (a functional group directly bonding to Si constituting the siloxane skeleton) is an unsubstituted or substituted monovalent hydrocarbon group having 1 to 15 carbon atoms, preferably 1 to 10 carbon atoms. Further, b is 0.7 to 2.1, preferably 0.8 to 2.0, c is 0.001 to 1.0, and b+c is 0.8 to 3.0, preferably 1.0 to It is a positive number satisfying 2.5.

Here, examples of R include the same groups as R in the crosslinkable fluorine-containing silicone polymer (A), but preferably those having no aliphatic unsaturated bonds such as alkenyl groups are preferred. Preferred specific examples include alkyl groups and aryl groups. Details of the alkyl group and aryl group are as described above.

The silicon-bonded hydrogen atoms (SiH groups) mentioned above may be bonded to the silicon atom at the end of the molecular chain or in the middle of the molecular chain (non-terminal of the molecular chain). It may be a combination of both.

(B1) The molecular structure of the non-fluorinated silicone crosslinking agent may be linear, cyclic, branched, or three-dimensional network structure.
Furthermore, the number of silicon atoms (or degree of polymerization) in one molecule is preferably 2 to 3,000, more preferably 3 or more, especially 4 or more, and more preferably 2000 or less, among which It is more preferably 1000 or less, and particularly preferably 500 or less.

(B1) Non-fluorinated silicone crosslinking agents include tris(dimethylhydrogensiloxy)methylsilane, tris(dimethylhydrogensiloxy)phenylsilane, 1,1,3,3-tetramethyldisiloxane, 1,3,5, 7-tetramethylcyclotetrasiloxane, methylhydrogencyclopolysiloxane, methylhydrogensiloxane/dimethylsiloxane cyclic copolymer, methylhydrogenpolysiloxane with trimethylsiloxy groups blocked at both ends, dimethylsiloxane/methylhydro blocked with trimethylsiloxy groups at both ends Gensiloxane copolymer, dimethylpolysiloxane with dimethylhydrogensiloxy groups blocked at both ends, methylhydrogenpolysiloxane blocked with dimethylhydrogensiloxy groups at both ends, dimethylsiloxane/methylhydrogensiloxane copolymer blocked with dimethylhydrogensiloxy groups at both ends , Methylhydrogensiloxane/diphenylsiloxane copolymer with both ends blocked by trimethylsiloxy groups, Methylhydrogensiloxane/diphenylsiloxane/dimethylsiloxane copolymer with both ends blocked with trimethylsiloxy groups, (CH ₃ ) ₂ HSiO _1/2 unit and SiO _4/2 units, copolymers consisting of (CH ₃ ) ₂ HSiO _1/2 units, SiO _4/2 units and (C ₆ H ₅ )SiO _3/2 units, etc. Examples of the compounds include those in which part or all of the methyl group is substituted with another alkyl group such as an ethyl group or a propyl group, or an aryl group such as a phenyl group. However, it is not limited to these.
Note that it is preferable to use two or more types of crosslinking agents in combination. The purpose of the combined use is also to expect the effect of promoting the crosslinking reaction.

(B1) The content of the non-fluorinated silicone crosslinking agent (if multiple types are used, the total amount) is 0.05 to 25 parts by weight based on 100 parts by weight of the crosslinkable fluorine-containing polymer (A). is preferred, more preferably 0.1 parts by mass or more, even more preferably 0.2 parts by mass or less, more preferably 20 parts by mass or less, even more preferably 10 parts by mass, and even more preferably 5 parts by mass. The following are even more preferred.

(B1) Specific examples of the non-fluorinated silicone crosslinking agent include 3062A, 3062B, 3062D, and SP 7297 manufactured by Dow Corning Toray Industries, Inc.

((B2) Fluorinated silicone crosslinking agent)
On the other hand, examples of the fluorinated silicone crosslinking agent (B2) include those in the formula (1) above, in which at least a portion of R is a group having a fluoro group. Examples of the group having a fluoro group include the above-mentioned fluorine substituents. The other structure of the (B2) fluorinated silicone crosslinking agent is as explained in (B1) the non-fluorinated silicone crosslinking agent, except that at least a part of R is a group having a fluoro group. is omitted.
Specific examples of the fluorinated silicone crosslinking agent include 3062C and Q2-7560 manufactured by Dow Corning Toray Industries, Inc.

(B2) The content of the fluorinated silicone crosslinking agent is preferably 0.1 to 50 parts by weight, more preferably 0.3 parts by weight or more, based on 100 parts by weight of the crosslinkable fluorine-containing polymer (A). Among them, 0.5 parts by mass or more is more preferable, and 30 parts by mass or less is more preferable, even more preferably 20 parts by weight or less, and even more preferably 10 parts by weight or less.

Furthermore, the molar ratio of silicon-bonded hydrogen atoms (SiH groups) in the silicone crosslinking agent (B) to the total amount of silicon-bonded alkenyl groups in the crosslinkable fluorine-containing polymer (A) is 0.3 to 20. It is preferably at least 0.5, more preferably at least 0.8, even more preferably at most 10, even more preferably at most 5.0.

((C) Curing catalyst)
More preferably, the release layer composition further contains (C) a curing catalyst in addition to (B) a silicone crosslinking agent. Note that component (C) may be added directly to the release layer composition, or may be added to the release layer composition as a component constituting the fluorine segregation promoter (X), and in both methods. May be added.
"Curing catalyst" is a catalyst for promoting the hydrosilylation addition reaction between the silicon atom-bonded alkenyl group of (A') the crosslinkable fluorine-containing silicone polymer and the hydrogen silane (SiH) group of (B) the silicone crosslinking agent. It is.
Examples of curing catalysts include platinum black, platinum chloride, chloroplatinic acid, reaction products of chloroplatinic acid and monohydric alcohols, complexes of chloroplatinic acid and olefins, platinum-based catalysts such as platinum bisacetoacetate, Examples include platinum group metal catalysts such as palladium catalysts and rhodium catalysts. However, it is not limited to these.

The content of the curing catalyst in the present release layer composition is preferably 0.5 to 500 ppm by mass as a metal equivalent to the total amount of (A) crosslinkable fluorine-containing polymer, and in particular, 5 to 500 ppm by mass. It is more preferably at least 10 ppm by mass, even more preferably at least 10 ppm by mass, more preferably at most 500 ppm by mass, even more preferably at most 200 ppm by mass.

(Method for preparing release layer composition)
As mentioned above, the fluorine segregation promoter can be prepared by mixing (A) a crosslinkable fluorine-containing polymer, (B) a silicone crosslinking agent, and (C) a curing catalyst, and then performing "pretreatment".
Note that the step of mixing components (A), (B), and (C) before the pretreatment is also referred to as the first step, and after the pretreatment, another (A) crosslinkable fluorine-containing polymer (second (A) The step of mixing component) and (E) a polymer containing no fluorine substituents is also referred to as a subsequent step.

As the silicone crosslinking agent (B) mixed in the first step, it is preferable to use the non-fluorinated silicone crosslinking agent (B1), as described above. In this case, the (B) silicone crosslinking agent used in the first step may be used alone (B1) non-fluorinated silicone crosslinking agent, or (B1) non-fluorinated silicone crosslinking agent and (B2) fluorinated silicone crosslinking agent. It may be used in combination with a silicone crosslinking agent. Further, as the first component (A) used in the first step, a solvent-curable silicone may be used.
Furthermore, in the first step, components other than components (A), (B), and (C) may be mixed. For example, the reaction control agent (D) described later and the compounds listed in other components may be mixed as appropriate. You may. Further, the mixing of each component in the first step is preferably carried out by stirring until each component is dissolved or substantially uniformly dispersed in the composition.

In the latter step, (A) a crosslinkable fluorine-containing polymer, (E) a polymer that does not contain fluorine substituents, and (X) a fluorine segregation promoter are mixed with the (A) component, as described above. (A') that is different from the crosslinkable fluorine-containing silicone polymer (first (A) component) used in the preparation of component (X) in at least any of the ratio, the structure of the fluorine substituent, and the viscosity or weight average molecular weight. It may also be a crosslinkable fluorine-containing silicone polymer.
Here, the blending ratio of component (X) and component (A) (second component (A)) will be detailed later. In addition, the (A) component mixed in the latter step is not particularly limited, but when used alone as a release layer, it should release more easily from the silicone adhesive than when the (X) component is used. is preferred. Specifically, it is preferable to use a crosslinkable fluorosilicone having a fluorine-containing substituent that is longer than the component (X) or having a branched structure.

In addition, in the latter step, in addition to (A) the crosslinkable fluorine-containing polymer, other components than (A) may be mixed with (X) the fluorine segregation promoter, such as (B) the silicone crosslinking agent. , (C) a curing catalyst, etc. may be further mixed. The (B) silicone crosslinking agent mixed in the latter step may be used alone as (B1) non-fluorinated silicone crosslinking agent or (B2) fluorinated silicone crosslinking agent alone, or (B1) non-fluorinated silicone crosslinking agent. Although the agent and (B2) the fluorinated silicone crosslinking agent may be used together, it is preferable that at least one type of (B2) fluorinated silicone crosslinking agent is included. When component (B2) is included, the degree of segregation on the surface of the release layer increases due to the effect of the fluorine segregation promoter (X), making it easier to obtain excellent curability and easy peelability.
The amount of the silicone crosslinking agent (B) mixed in the latter step is not particularly limited, but the ratio to the amount of the silicone crosslinking agent (B) mixed in the earlier step is, for example, 0.1 to 100 on a mass basis. , preferably 0.25 to 70, more preferably 0.5 to 50.

Further, in this method, after a predetermined pre-crosslinking time has elapsed, (D) a reaction control agent such as acetylene alcohol, which will be described later, may be added or added. If the crosslinking reaction progresses too much, cloudiness or gelation of the liquid may occur depending on the material type, but the crosslinking reaction can be moderately suppressed by adding or adding a reaction control agent.
(D) The reaction control agent may be added in advance to (A) the crosslinkable fluorine-containing polymer (component (A)) to be mixed with (X) the fluorine segregation promoter.

((D) Reaction control agent)
The release layer composition and the present release layer may contain a reaction control agent in addition to the above components, if necessary.
(D) As the reaction control agent, acetylene alcohol represented by the following general formula (2), etc. can be used.

CH≡CC(R ₂ )(OH)R ₁ (2)

In formula (2), R ₁ is a linear or branched monovalent hydrocarbon group having 5 to 15 carbon atoms, and R ₂ is a linear monovalent hydrocarbon group having 1 to 3 carbon atoms. It is.
In the above formula (2), R ₁ is preferably a monovalent hydrocarbon group having 6 to 14 carbon atoms, particularly preferably a monovalent hydrocarbon group having 8 to 12 carbon atoms. .
Specific examples of _R1 include alkyl groups such as a pentyl group, neopentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group, and dodecyl group, and alkenyl groups such as a pentenyl group, hexenyl group, and heptenyl group. Examples include groups. However, it is not limited to these.
In the above formula (2), when the number of carbon atoms in the monovalent hydrocarbon group of R ₁ is 5 or more, the volatility of the reaction control agent becomes low and a sufficient control effect can be obtained. On the other hand, when the number of carbon atoms is 15 or less, it is possible to prevent the control effect from becoming weak due to a decrease in the active ingredient of acetylene alcohol per mol, and it is not necessary to add a large amount to obtain the desired reaction control effect.

In the above formula (2), R ₂ is a linear monovalent hydrocarbon group having 1 to 3 carbon atoms, preferably a hydrocarbon group having 1 to 2 carbon atoms. Specific examples of R ₂ include alkyl groups such as a methyl group, ethyl group and n-propyl group, and alkenyl groups such as a vinyl group, allyl group and n-propenyl group. However, it is not limited to these. The smaller the number of carbon atoms in R ₂ , the better the effect of controlling the reaction of the silicone composition, and a methyl group is preferable.

One type of reaction control agent may be used, or two or more types may be used in combination, if necessary.
The content of the reaction control agent is preferably 0.001 to 5.0 parts by mass, more preferably 0.01 parts by mass or more, and 0.05 parts by mass or more per 100 parts by mass of the release layer composition. It is more preferably at least 1.0 parts by mass, even more preferably at most 0.5 parts by mass. Note that "100 parts by mass of the release layer composition" means 100 parts by mass of solid content in the release layer composition excluding volatile components (solvent), and the same applies below.

(Other ingredients)
In addition to the above-mentioned components, the release layer composition may contain other components as necessary. For example, resins other than the above (A) to (E) and (X) such as non-curing silicone, silicone rubber, silicone resin, polyolefin resin, acrylic resin, urethane resin, epoxy resin, alkyd resin, cellulose, etc. Various particles such as silica particles, alumina particles, silicone rubber particles, silicone resin particles, and silicone rubber/resin composite particles; silane coupling agents, etc. . However, it is not limited to these.

The release layer composition may contain additives such as a light release agent, a heavy release agent, and an adhesion improver, if necessary.
Specific examples of light release agents, heavy release agents, and adhesion improvers include KS-3800 and X-92-185 manufactured by Shin-Etsu Chemical Co., Ltd.; BY24- manufactured by Dow Corning Toray Co., Ltd. 850, SD7292, BY24-4980, SP7297, BY24-808, SD7200, etc. However, it is not limited to these.

(solid content)
The release layer composition may be diluted with a diluting solvent such as an organic solvent, as described below. The solid content concentration of the release layer composition is preferably 0.1% by mass to 100% by mass, more preferably 0.5% by mass or more, even more preferably 1.0% by mass or more, among which It is even more preferably 1.5% by mass or more, more preferably 50% by mass or less, even more preferably 20% by mass or less, even more preferably 10% by mass or less.

The solid content of the release layer composition preferably contains alkyl vinyl polysiloxane and alkyl hydrogen polysiloxane as described above. Among them, the preferred amount of alkylvinylpolyloxane containing an alkenyl group such as a vinyl group is 85.0 to 99.9% by mass, and more preferably 90.0% by mass or more, based on the solid mass. Among them, the content is more preferably 92.0% by mass or more, more preferably 99.5% by mass or less, and even more preferably 99.0% by mass or less.

<<Release film>>
A release film according to an example of an embodiment of the present invention includes a base film and a release layer on one or both sides of the base film.

<Release layer>
The release layer in the release film is a layer obtained by curing the above-mentioned release layer composition.
In the concentration distribution of fluorine atoms in the thickness direction within the release layer, it is preferable that fluorine is unevenly distributed on the surface of the release layer.
It is presumed that by unevenly distributing fluorine on the surface of the release layer in this way, it is possible to realize excellent easy release properties and low migration properties that are easy to release from the silicone pressure-sensitive adhesive layer.
In the present invention, as described above, by including (A) a crosslinkable fluorine-containing polymer, (E) a polymer not containing a fluorine substituent, and (X) a fluorine segregation promoter, fluorine can be unevenly distributed on the surface of the release layer. Can be done. In particular, by including (A') a crosslinkable fluorine-containing silicone polymer, (E') a silicone polymer containing no fluorine substituents, and (X) a fluorine segregation promoter, fluorine can be unevenly distributed more effectively.

Note that when (X) a fluorine segregation promoter is used, fluorine can be more unevenly distributed on the surface than when (X) a fluorine segregation promoter is not used together. That is, by having the above configuration, it is possible to improve easy releasability, low migration properties, and adhesion to the base material compared to the case where (X) fluorine segregation promoter is not used together. . Although the detailed mechanism is not clear, the "pre-treated" (X) fluorine segregation promoter undergoes a reaction in the liquid and increases in molecular weight. As a result, (X) the fluorine segregation promoter becomes more likely to segregate to the surface of the release layer. (X) Fluorine segregation accelerator has a high affinity with (A') crosslinkable fluorine-containing silicone polymer and its crosslinking agent, so the crosslinkable fluorine-containing silicone polymer is also "pulled" and does not segregate on the surface of the release layer. It is presumed that this promotes easy peelability.
In order to make fluorine unevenly distributed on the surface of the release layer in this way, it is preferable to use (X) a fluorine segregation promoter in combination. However, the method is not limited to this method.

The fluorine atom content in the release layer is preferably 3000 mol ppm or more, particularly 10,000 mol ppm or more, from the viewpoint of being able to stably obtain preferable easy releasability from silicone adhesives. Among these, it is more preferably 50,000 mol ppm or more. On the other hand, the upper limit is not particularly limited, but is preferably 900,000 mol ppm or less, preferably 800,000 mol ppm or less, and more preferably 700,000 mol ppm or less.

The fluorine atomic ratio on the surface of the release layer is preferably 20% or more and 80% or less. When the fluorine atomic ratio is within the above range, it becomes easy to achieve both easy releasability and low migration properties. The fluorine atomic ratio is more preferably 25% or more and 60% or less, and even more preferably 30% or more and 50% or less.
The fluorine atomic ratio is determined by measuring carbon (C), oxygen (O), silicon (Si), and fluorine (F) atoms using XPS (X-ray photoelectron spectroscopy) and GC-IB (gas cluster ion beam). It can be measured by determining the ratio of fluorine atoms.

Further, the release layer preferably has a fluorine concentration distribution ratio t _d (t1 [75%]/t2 [50%]) in the thickness direction of 1 to 70%. Note that the F concentration distribution ratio t _d (t1 [75%]/t2 [50%]) in the thickness direction is measured by the following method.
That is, using GC-IB for XPS, carbon (C), oxygen (O), silicon (Si), and fluorine ( Measure the concentration distribution (ratio) of atoms of F). In the obtained fluorine atom concentration distribution, when the fluorine atomic ratio at the outermost surface (sputtering time 0) is taken as a reference, the sputtering time (t1 [75%]) required for the fluorine atomic ratio to decrease to 75% of the outermost surface The ratio t _d (t1 [75%]/t2 [50%]) of the time (t2 [50%]) for the fluorine atom ratio to decrease to 50% of the outermost surface is calculated in percentage (%).

The smaller the value of the ratio t _d (t1 [75%]/t2 [50%]), the more unevenly fluorine is distributed on the surface side of the release layer. Therefore, when the ratio t _d (t1 [75%]/t2 [50%]) is as low as 70% or less as described above, easy releasability can be easily achieved. From such a viewpoint, the ratio t _d (t1 [75%]/t2 [50%]) is more preferably 60% or less, further preferably 55% or less, and even more preferably 50% or less.
In addition, the larger the value of the ratio t _d (t1 [75%]/t2 [50%]), the more stable the fluorine atoms on the surface of the release layer are because a certain amount of fluorine atoms are dispersed to the inside of the release layer. It is possible to prevent the release agent component from migrating to the silicone adhesive layer. From such a viewpoint, the ratio t _d (t1[75%]/t2[50%]) is preferably 1% or more as described above, more preferably 4% or more, and still more preferably 7% or more. , particularly preferably 10% or more.

(Thickness of release layer)
The thickness of the release layer is not particularly limited. The thicker the release layer is, the more difficult it is to transmit the influence of the base material, such as the influence of the hardness of the base material, to the release surface of the release film, which is preferable. In view of the above, the thickness of the release layer is preferably 0.01 μm or more, particularly 0.05 μm or more, and even more preferably 0.10 μm or more. On the other hand, if the thickness of the release layer is kept below a certain level, it is possible to prevent the occurrence of blocking and deterioration of the coat appearance, so it is preferably 10 μm or less, especially 5 μm or less, especially 3 μm or less, and 1 μm or less. It is more preferable that the thickness is 0.5 μm or less, and particularly preferably 0.5 μm or less.

<Base film>
The material for the base film of the release film is not particularly limited as long as it has a film shape. For example, it may be made of paper, resin, metal, etc. Among these, resin is preferred from the viewpoint of mechanical strength and flexibility.

Examples of the resin base film (resin film) include films made of polymers such as polyethylene, polypropylene, polyester, polystyrene, polycarbonate, polyethersulfone, polyamide, and polyimide. However, it is not limited to these. Further, as long as it can be made into a film, it may be a mixture of these materials (polymer blend) or a composite of structural units (copolymer).

Among the films exemplified above, polyester films are particularly preferred because they have excellent physical properties such as heat resistance, flatness, optical properties, and strength.
The polyester film may be a single layer or a multilayer film (laminated film) having two or more layers with different properties.
Further, the polyester film may be a non-stretched film (sheet) or a stretched film. Among these, a stretched film stretched uniaxially or biaxially is preferred. Among these, biaxially stretched films are more preferable from the viewpoint of balance of mechanical properties and flatness.

The polyester that is the main component resin of the polyester film may be a homopolyester or a copolyester.
In addition, the main component resin means the resin with the largest mass percentage among the resins constituting the present polyester film, and is 50% by mass or more, or 75% by mass or more, or 90% by mass or more of the resin constituting the present polyester film. It is assumed that it accounts for 100% by mass or more.

As the above-mentioned homopolyester, one obtained by polycondensing an aromatic dicarboxylic acid and an aliphatic glycol is preferable. Examples of aromatic dicarboxylic acids include terephthalic acid and 2,6-naphthalene dicarboxylic acid, and examples of aliphatic glycols include ethylene glycol, diethylene glycol, 1,4-butanediol, and 1,4-cyclohexanedimethanol. can be mentioned. However, it is not limited to these.
Typical homopolyesters include polyethylene terephthalate (PET) and polybutylene terephthalate (PBT).

On the other hand, when the polyester is a copolymerized polyester, it is preferably a copolymer containing 30 mol% or less of a third component.
The dicarboxylic acid component of the copolymerized polyester includes one or more of isophthalic acid, phthalic acid, terephthalic acid, 2,6-naphthalenedicarboxylic acid, adipic acid, and sebacic acid, and the glycol component includes ethylene glycol, Examples include one or more of diethylene glycol, propylene glycol, 1,4-butanediol, 1,4-cyclohexanedimethanol, neopentyl glycol, and the like. However, it is not limited to these.

Among these, polyethylene terephthalate, in which 60 mol% or more, preferably 80 mol% or more, is ethylene terephthalate units is preferred as the main component resin of the base film.

The base film can also contain particles for the main purpose of imparting slipperiness and preventing scratches in each step. When particles are contained, the types of particles contained are not particularly limited as long as they can impart slipperiness; specific examples include silica, calcium carbonate, magnesium carbonate, barium carbonate, sulfuric acid. Examples include inorganic particles such as calcium, calcium phosphate, magnesium phosphate, kaolin, aluminum oxide, and titanium oxide, and organic particles such as acrylic resin, styrene resin, urea resin, phenol resin, epoxy resin, and benzoguanamine resin. However, it is not limited to these. Furthermore, precipitated particles in which a part of a metal compound such as a catalyst is precipitated and finely dispersed during the polyester manufacturing process can also be used.

On the other hand, the shape of the particles to be used is not particularly limited, and any shape such as spherical, lumpy, rod-like, flat, etc. may be used. Furthermore, there are no particular limitations on its hardness, specific gravity, color, etc. Two or more types of these series of particles may be used in combination as necessary.

The average particle diameter of the particles is preferably 5 μm or less, more preferably 0.1 μm or more and 3 μm or less. By using the average particle size within the above range, it is possible to give the film an appropriate surface roughness and ensure good slipperiness and smoothness.
Note that the average particle diameter of the above particles can be measured as follows.
The average particle size of the particles as a raw material can be measured as the average particle size (D50) determined from the volume-based particle size distribution measured by a dynamic light scattering method or the like.
The average particle size of the particles contained in the base film can be determined by observing the surface or cross section of the base film using an optical microscope or scanning electron microscope (SEM), and determining the diameter of 10 or more particles. It can be measured and found as the average value. At this time, 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.

Further, the particle content in the base film is preferably 5% by mass or less, more preferably 0.0003% by mass or more and 3% by mass or less. Sliding properties can be ensured by making the particle content equal to or higher than these lower limits. Moreover, when there are no particles or when there are only a few particles, the transparency of the film becomes high, resulting in a good film. However, since the slip properties may be insufficient, it may be necessary to take measures such as incorporating particles into the coating layer to improve the slip properties.

Further, in a multilayer film, it is preferable to have a surface layer constituting the surface of the base film and a core layer, and it is preferable that the surface layer has the above-mentioned particles. When the surface layer contains the above particles, the content of the particles in the surface layer is preferably within the above range.
The multilayer film may have a two-layer structure including a surface layer and a core layer, or may have a three-layer structure including a surface layer, a core layer, and a surface layer. Moreover, the core layer may consist of two or more layers, and may have a layered structure of four or more layers.

<Example of configuration of release film>
The release film may have a structure in which a release layer is provided on one side or both sides of the base film, and as described later, the base film and the release layer are provided on one or both sides of the release film. may be directly laminated or may be laminated via other layers.

The "other layers" include, for example, an anchor coat layer for increasing the adhesion between the base film and the release layer, and a sealing layer to prevent exudation (bleeding, plate-out) of compounds and oligomers on the film surface. Examples include an oligomer sealing layer with antistatic properties and an antistatic layer with antistatic properties. However, it is not limited to these.

Specific configuration examples of the release film include base film/release layer, base film/anchor coat layer/release layer, base film/antistatic layer/release layer, base film/oligomer sealing. Layer/release layer, antistatic layer/base film/antistatic layer/release layer, oligomer sealing layer/base film/oligomer sealing layer/release layer, base film/antistatic layer/oligomer seal Stop layer/release layer, release layer/base film/release layer, release layer/anchor coat layer/base film/anchor coat layer/release layer, release layer/antistatic layer/base film / Antistatic layer / Release layer, release layer / Oligomer sealing layer / Base film / Oligomer sealing layer / Release layer, release layer / Oligomer sealing layer / Antistatic layer / Base film / Antistatic Examples include layer/oligomer sealing layer/release layer. However, it is not limited to these.

(Anchor coat layer)
Examples of the anchor coat layer include those containing polymeric materials such as polyethylene, polypropylene, styrene copolymers, polyester, polyurethane, polyvinyl alcohol, polyethyleneimine, polyacrylate, polymethacrylate, and modified products thereof. Can be done. However, it is not limited to these.

(oligomer sealing layer)
The oligomer sealing layer may contain a hydrolyzable alkoxysilicate and/or a polycondensate thereof. Examples of the hydrolyzable alkoxysilicate include a structure represented by the following general formula (3) (R ¹ represents a hydrocarbon group having 1 to 10 carbon atoms).

Si(OR ¹ ) ₄ (3)

In formula (3), R ¹ represents a hydrocarbon group having 1 to 10 carbon atoms.

The oligomer sealing layer may further contain inorganic particles, and specific examples of the inorganic particles include silica, alumina, kaolin, calcium carbonate, titanium oxide, barium salt, and the like. However, it is not limited to these.
In addition, the oligomer sealing layer contains antifoaming agents, coating properties improvers, thickeners, organic lubricants, organic polymer particles, antioxidants, ultraviolet absorbers, foaming agents, dyes, etc. You can. However, it is not limited to these.

(Antistatic layer)
The antistatic layer preferably contains a conductive polymer and a binder polymer from the viewpoint of imparting antistatic properties.
Note that the coating liquid may contain other components as long as the gist of the present invention is not impaired.

Specifically, the conductive polymer preferably contains a polythiophene having a repeating unit represented by the following formula (4) and its derivative (I).

In the above formula (4), R ₁ and R ₂ each independently represent a hydrogen atom, an aliphatic hydrocarbon group having 1 to 12 carbon atoms, an alicyclic hydrocarbon group, or an aromatic hydrocarbon group, for example, Examples include methyl group, ethyl group, propyl group, isopropyl group, butyl group, cyclohexylene group, and benzene group. However, it is not limited to these.

Note that the above-mentioned layers such as the anchor coat layer, antistatic layer, and oligomer sealing layer can be formed at the same time as the film-form base material is formed using an in-line coating method, or they can be formed in a separate process on the base film that has already been formed. It can be formed using either of the offline coating methods. A specific example of the in-line coating method is a method in which coating is performed at any stage from melt extrusion of polyester to biaxial stretching, heat setting, and winding. Usually, the coating is applied to either a substantially amorphous unstretched sheet obtained by melting and quenching, a uniaxially stretched film that is then stretched in the longitudinal direction (longitudinal direction), or a biaxially stretched film before heat setting. This is the way to do it.

<<Release layer composition and method for producing release film>>
Next, an example of a method for producing a release layer composition and a release film will be described. As an example of a preferred method for producing the release layer composition of the present invention, at least one crosslinkable fluorine-containing polymer (A) is subjected to a crosslinking reaction in advance in a blended solution, and then at least another ( A) A crosslinkable fluorine-containing polymer is mixed and prepared.
More specifically, after mixing (A) a crosslinkable fluorine-containing polymer (first (A) component), (B) a silicone crosslinking agent, and (C) a curing catalyst, the mixture is stirred and/or left to stand. "Pre-treatment" is carried out to obtain a pre-treatment composition ((X) fluorine segregation promoter). Next, the pre-treatment composition ((X) fluorine segregation promoter) is mixed with (A) a crosslinkable fluorine-containing polymer (second (A) component) that is different from the first (A) component. A method for preparing a release layer composition can be mentioned.
The obtained release layer composition is preferably used to produce a release film by applying the release layer composition to at least one side of a base film.

In general, measures to reduce the amount of crosslinkable fluorosilicone polymer (fluorinated silicone) used in release films include, for example, reducing the content of fluorinated silicone in the release layer, or Possible measures include reducing the thickness. However, with the former method, the original objective of easy peelability is lost, and with the latter method, there are problems such as an inability to form a uniform release layer and a decrease in stability of peeling force. be.
In contrast, in the present invention, as described above, by including (A) a crosslinkable fluorine-containing polymer, (E) a polymer that does not contain a fluorine substituent, and (X) a fluorine segregation promoter (pretreatment composition), Easy removability can be maintained. In particular, by containing (A') a crosslinkable fluorine-containing silicone polymer, (E') a silicone polymer containing no fluorine substituents, and (X) a fluorine segregation promoter (pretreatment composition), extremely suitable easy peelability can be achieved. can be maintained.
Usually, when a solution of (A') a crosslinkable fluorine-containing silicone polymer mixed with (E') a silicone polymer that does not contain a fluorine substituent in a large amount (e.g. twice the solid weight) is coated on a film and dried. , (A') Segregation of the crosslinkable fluorine-containing silicone polymer onto the surface of the release layer may not occur sufficiently, making it difficult to obtain desired easy release properties.
Therefore, in the present invention, in forming the release layer, first, a "pre-treated" (X) fluorine segregation promoter is prepared, and then (A) a crosslinkable fluorine-containing polymer, and (E) a fluorine substituent. By preparing a release layer composition by mixing a polymer that does not contain (A), the crosslinkable fluorine-containing polymer (A) can be sufficiently segregated on the surface of the release layer, and is more resistant to silicone adhesives. It is possible to form a coating film that is easy to peel off (lightly peelable).

After mixing (X) the fluorine segregation promoter obtained in the above pretreatment and (A) the crosslinkable fluorine-containing polymer, it is preferable to dilute with a solvent as necessary to prepare a release layer composition. .
The solvent for dilution may be a polar solvent or a non-polar solvent. Furthermore, two or more of the above solvents may be used in combination.
Examples of the polar solvents include alcohols such as ethanol, (iso)propyl alcohol, methyl acetate, ethyl acetate, (iso)propyl acetate, (iso)butyl acetate, (iso)pentyl acetate, ethyl lactate, and ethyl benzoate. esters, methyl ethyl ketone, methyl isobutyl ketone, cyclopentanone, cyclohexanone, diacetone alcohol, ketones such as diisobutyl ketone, ethylene glycol, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, propylene glycol monomethyl ether acetate, propylene glycol monomethyl Examples include glycols such as ether, N-methyl-2-pyrrolidone, N,N-dimethylformamide, tetrahydrofuran, and acetonitrile. However, it is not limited to these.

Examples of the non-polar solvent include aromatic hydrocarbons such as benzene, toluene, and xylene, aliphatic hydrocarbons such as hexane, heptane, and octane, hydrocarbons having a branched structure such as isohexane, isooctane, and isononane, and cyclohexane. , alicyclic hydrocarbons such as cycloheptane and cyclooctane, ethers such as diisopropyl ether, and dioxane.
Fluorine solvents may be used as non-polar solvents. Examples of the fluorine solvent include hydrofluoroethers, metaxylene hexafluoride, tridecafluorooctane, and the like. Furthermore, as the fluorine solvent, commercially available products such as "FS Thinner" (manufactured by Shin-Etsu Chemical Co., Ltd.) may be used. However, it is not limited to these.

As a method for applying the release layer composition to the base film, a coating technique such as that described in "Coating Method" (written by Yuji Harasaki, published by Maki Shoten, 1979) can be used, for example. For example, coating heads include air doctor coater, blade coater, rod coater, knife coater, squeeze coater, impregnation coater, reverse roll coater, transfer roll coater, gravure coater, kiss roll coater, cast coater, spray coater, curtain coater, and calendar coater. , extrusion coater, etc. However, it is not limited to these.

Note that the method for preparing the release layer composition is not limited to the above-mentioned method, and other methods may be used, for example, the above-mentioned pretreatment may not be performed. That is, after mixing component (X), component (B), and component (C), the resulting composition is immediately mixed with (A) crosslinkable fluorine-containing polymer (component (A)) and separated. A mold layer composition may be prepared.
Further, the release layer composition may be prepared by any other method as long as it is obtained by mixing the components constituting the composition, and the components may be mixed in a different order from the above.
Furthermore, when the release layer composition contains the above-described component (E) and other components, these components may be blended at any stage.

(Method of forming other layers)
As mentioned above, a release film is produced by forming "other layers" such as an anchor coat layer, an antistatic layer, an oligomer sealing layer, etc. on one or both sides of a base film as necessary, and then applying a release layer. The composition can be applied and cured to form the composition.
When forming "other layers" in this way, an anchor coat layer, an antistatic layer, an oligomer sealing layer, etc. may be added on at least one side of the base film unwound from the roll state, as necessary. After forming the "other layer", a release layer composition is applied and cured to form a release layer.

<Physical properties of release film>
The release film can have the following physical properties.

(Heating peeling force)
The heat peeling force of the release layer is preferably 65 mN/cm or less, more preferably 60 mN/cm or less, especially 40 mN/cm or less, especially 30 mN/cm or less, and especially 20 mN/cm. It is more preferable that it is as follows. The lower the heating peeling force is, the less force is required for peeling from the silicone adhesive, and problems such as poor peeling and deformation of the adhesive layer in the production process can be suppressed. Furthermore, by using a release film with excellent easy releasability, it is possible to prevent the release film from peeling off on an unintended side in a double-sided pressure-sensitive adhesive tape having release films on both sides of the pressure-sensitive adhesive sheet.
On the other hand, the lower limit is not particularly limited, but is preferably 1 mN/cm or more in view of long-term storage of a laminate in which a release film and an adhesive are laminated.
In addition, evaluation of heat peeling force can be implemented by the method described later.

(Adhesive peeling force)
The adhesive peeling force of the release layer is preferably 750 mN/cm or less, especially 600 mN/cm or less, especially 500 mN/cm or less, and even more preferably 400 mN/cm or less. The lower the adhesive peeling force is, the less force is required to peel off the silicone adhesive, and it is possible to suppress problems such as poor peeling and deformation of the adhesive layer in the production process. Furthermore, by using a release film with excellent easy releasability, it is possible to prevent the release film from peeling off on an unintended side in a double-sided pressure-sensitive adhesive tape having release films on both sides of the pressure-sensitive adhesive sheet.
On the other hand, the lower limit of the adhesive peeling force is not particularly limited, but is preferably 1 mN/cm or more in view of long-term storage of a laminate in which a release film and an adhesive are laminated.
Note that the adhesive peeling force can be evaluated by the method described below.

(Residual adhesion rate)
The residual adhesion rate of the release layer is preferably 85% or more, preferably 90% or more, and more preferably 95% or more.
By satisfying the above range, the transfer of the release layer components to the surface of the other adherend with which the surface of the release layer comes into contact is reduced.
The residual adhesion rate is an index for checking the transfer of the release agent, and is usually expressed as a relative ratio to the blank after adhesive tape is applied to a surface coated with the release agent and removed. value (see JIS Z 0109:2015).
In this application, the residual adhesion rate will be evaluated by the method described below.

<<Film laminate>>
The above-mentioned release film (hereinafter sometimes referred to as "the release film of the present invention") can be used in various film laminates.
A film laminate according to an embodiment of the present invention includes the release film of the present invention, a silicone adhesive layer, and a laminate film having a functional layer. Examples include a laminated film having a silicone adhesive layer interposed therebetween. In each film laminate, the release film of the present invention is arranged at a position where the release layer contacts the silicone adhesive layer.

<Laminated film (1)>
The above-mentioned "laminated film having a functional layer" is, for example, a laminated film (" Laminated film (1)") can be mentioned. Note that the base film is the same as that described above as <base film>. In addition, in the following description, the base film of the laminated film (1) may be referred to as the base film (1).

In the laminated film (1), the crosslinked resin layer may be formed from a crosslinked resin layer composition containing a conductive polymer, a binder polymer, and optionally a crosslinking agent and particles. . Such a crosslinked resin layer may be provided, for example, on the surface of the base film (1) opposite to the surface to be adhered to the silicone adhesive layer.

(conductive polymer)
It is preferable that the conductive polymer contains a composition consisting of a polythiophene compound and a polyanion.

The polyanion refers to an "acidic polymer in a free acid state", and is preferably a polymeric carboxylic acid, a polymeric sulfonic acid, a polyvinylsulfonic acid, or the like. Specific examples of polymeric carboxylic acids include polyacrylic acid, polymethacrylic acid, and polymaleic acid. A specific example of the polymeric sulfonic acid is polystyrene sulfonic acid. Among these, polystyrene sulfonic acid is most preferred in terms of electrical conductivity. Note that the free acid may be in the form of a salt in which part of it is neutralized. It is thought that by using these polyanions during polymerization, polythiophene compounds, which are originally insoluble in water, can be easily dispersed or made aqueous, and their acid function also serves as a doping agent for polythiophene compounds. .

Furthermore, the polymeric carboxylic acid and polymeric sulfonic acid can also be used in a form copolymerized with other copolymerizable monomers, such as acrylic esters, methacrylic esters, styrene, and the like. The molecular weight of the polymeric carboxylic acid or polymeric sulfonic acid used as the polyanion is not particularly limited, but in terms of stability and conductivity of the coating material, the mass average molecular weight is preferably 1,000 to 1,000,000, more preferably 5,000. ~150,000. It may also contain a portion of alkali salts such as lithium salts and sodium salts, ammonium salts, etc., as long as the characteristics of the present invention are not impaired. Even in the case of neutralized salts, it is known that polystyrene sulfonic acid and ammonium salts, which function as very strong acids, shift their equilibrium toward the acidic side due to the progress of the equilibrium reaction after neutralization. It is thought that it works.

Examples of polythiophene compounds include polythiophene or derivatives thereof. The polythiophene or its derivative is as described above. It is preferable for the polyanion to be present in excess of the solid content mass ratio relative to the polythiophene compound in terms of conductivity, and the polyanion is present in an amount of 1 to 5 parts by mass per 1 part by mass of the polythiophene compound. Parts by mass are preferred, and 1 to 3 parts by mass are more preferred. Regarding compositions comprising the above-mentioned polythiophene compound and polyanion, for example, JP-A-6-295016, JP-A-7-292081, JP-A-1-313521, JP-A-2000-6324, European patents. Examples are described in EP602731, US Patent US5391472, etc., but methods other than these may also be used. For example, after obtaining 3,4-ethylenedioxythiophene using an alkali metal salt of 3,4-dihydroxythiophene-2,5-dicarboxyester as a starting material, potassium peroxodisulfate was added to an aqueous polystyrene sulfonic acid solution. , iron sulfate, and the previously obtained 3,4-ethylenedioxythiophene are introduced and reacted to form polyanions such as polystyrene sulfonic acid into polythiophene compounds such as poly(3,4-ethylenedioxythiophene). There is a method for obtaining a composition in which
For example, there is also a description in Latest Trends in Conductive Polymer Technology (published by Toray Research Center, Inc., June 1, 1999, 1st printing).

(binder polymer)
The binder polymer constituting the crosslinked resin layer composition is determined by the number average value determined by gel permeation chromatography (GPC) measurement in accordance with the Flow Scheme for Safety Evaluation of Polymer Compounds (sponsored by the Chemical Substances Council, November 1985). It is defined as a polymer compound having a molecular weight (Mn) of 1000 or more and having film-forming properties.

The binder polymer constituting the crosslinked resin layer composition may be a thermosetting resin or a thermoplastic resin as long as it is compatible with or can be mixed and dispersed with the ionic polymer. For example, polyesters such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate; polyimides such as polyimide and polyamideimide; polyamides such as polyamide 6, polyamide 6,6, polyamide 12, and polyamide 11; polyvinylidene fluoride, polyvinyl fluoride, and Fluororesins such as tetrafluoroethylene, ethylenetetrafluoroethylene copolymer, polychlorotrifluoroethylene; vinyl resins such as polyvinyl alcohol, polyvinyl ether, polyvinyl butyral, polyvinyl acetate, polyvinyl chloride; epoxy resins; oxetane resins; xylene resins; Examples include aramid resins; polyimide silicones; polyurethanes; polyureas; melamine resins; phenolic resins; polyethers; acrylic resins and copolymers thereof. These may be used alone or in combination of two or more. However, it is not limited to these.

The binder polymer may be dissolved in an organic solvent as a raw material, or it may be added with a functional group such as a hydroxyl group, a sulfo group, or a carboxy group and made into an aqueous solution, or it may be made into an aqueous dispersion using a surfactant. You can. Further, the binder polymer may be used in combination with a crosslinking agent, a curing agent such as a polymerization initiator, a polymerization accelerator, a solvent, a viscosity modifier, etc., if necessary.

Among the binder polymers, from the viewpoint of adhesion to the release layer, it is preferable to use one or more selected from polyester resins, acrylic resins, urethane resins, and vinyl resins.

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 even more preferably 10 to 60% by mass in solid content mass ratio. be. When the content of the binder polymer is within the above range, the resulting crosslinked resin layer can have sufficient strength and adhesion to the release layer.

(Crosslinking agent)
The crosslinked resin layer composition may contain a crosslinking agent if necessary.
Crosslinking agents mainly improve the cohesiveness, surface hardness, scratch resistance, solvent resistance, water resistance, etc. of the crosslinked resin layer through crosslinking reactions with functional groups contained in other resins and compounds, and self-crosslinking. be able to.

Any type of crosslinking agent can be used. 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, dialcohol aluminate-based coupling agents, Aldehyde compounds, zircoaluminate coupling agents, peroxides, thermally or photoreactive vinyl compounds, photosensitive resins, and the like are preferably used. Among these, from the viewpoint of synergistically obtaining good adhesion to the mold release layer, it is preferable to use a crosslinking agent such as a melamine compound or an epoxy compound, or a silane coupling agent.
In addition, these crosslinking agents also include polymer-type crosslinking reactive compounds in which other polymer skeletons have reactive groups, and in the present invention, one or more of these crosslinking agents are used in combination. You may.

The content of the crosslinking agent in the crosslinked resin layer composition is preferably 1 to 90% by mass, more preferably 3 to 50% by mass, and even more preferably 5% to 40% by mass in solid content. be. If the ratio of the crosslinking agent is within the above range, sufficient adhesion to the release layer can be obtained due to the synergistic effect with the binder polymer.

(particle)
The crosslinked resin layer may contain particles for the purpose of improving the adhesion and slipperiness of the crosslinked resin layer.
There is no particular restriction on the average particle size of the particles. For example, when used for optical purposes, from the viewpoint of film transparency, the thickness is preferably 1.0 μm or less, more preferably 0.5 μm or less, and even more preferably 0.2 μm or less. Further, from the viewpoint of improving the adhesion and slipperiness of the crosslinked resin layer, the thickness is preferably 0.01 μm or more.
Specific examples of particles include inert inorganic particles such as silica, alumina, calcium carbonate, and titanium dioxide, fine particles obtained from polystyrene resins, polyacrylic resins, and polyvinyl resins, and organic particles represented by crosslinked particles of these. can be mentioned.

Note that the average particle diameter of the above particles can be measured as follows.
The average particle size of the particles as a raw material can be measured as the average particle size (D50) determined from the volume-based particle size distribution measured by a dynamic light scattering method or the like.
The average particle diameter of the particles contained in the crosslinked resin layer can be determined by observing the surface or cross section of the crosslinked resin layer using an optical microscope or scanning electron microscope (SEM), and determining the diameter of 10 or more particles. It can be measured and found as the average value. At this time, 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.

In another embodiment, the crosslinked resin layer may be an easily adhesive layer formed from a composition containing a binder polymer, a crosslinking agent, a silane coupling agent, particles, and the like. The easily adhesive layer is an easily adhesive layer for the silicone adhesive layer, and is preferably provided on the side of the base film (1) that is adhered to the silicone adhesive layer. The binder polymer, crosslinker, and particles are as described above.

(others)
The crosslinked resin layer may contain surfactants, antifoaming agents, coating properties improvers, mold release agents, thickeners, organic lubricants, antistatic agents, conductive agents, light absorbers such as ultraviolet rays, and antioxidants as necessary. A foaming agent, a blowing agent, a dye, a pigment, etc. may also be contained.

The components in the crosslinked resin layer can be analyzed by, for example, TOF-SIMS, ESCA, fluorescent X-ray analysis, or the like.
Further, in the laminated film (1), a crosslinked resin layer formed from a crosslinked resin layer composition containing a conductive polymer and a binder polymer is provided on one side of the base film (1), and a crosslinked resin layer formed from a crosslinked resin layer composition containing a conductive polymer and a binder polymer is provided on the other side. An easily adhesive layer may be provided.

(Method for forming crosslinked resin layer)
Regarding the method of forming the crosslinked resin layer, it may be provided by in-line coating, in which the film surface is treated on the production line of the base film (1), such as during the stretching process of a stretched film such as a polyester film, or once produced. Off-line coating, which is applied onto the base film (1) outside the production line, may also be employed. In-line coating is preferably used because it can be applied at the same time as the film is formed, so it can be manufactured at low cost, and the thickness of the crosslinked resin layer can be changed depending on the stretching ratio.

Regarding in-line coating, although it is not limited to the following, for example, in sequential biaxial stretching, coating treatment can be performed particularly before the transverse stretching after the longitudinal stretching is completed. When a cross-linked resin layer is provided on a base film (1) such as a polyester film by in-line coating, coating can be performed simultaneously with film formation, and the cross-linked resin layer can be treated at high temperatures, and the laminated film ( A polyester film suitable for 1) can be produced.

When a crosslinked resin layer is provided by in-line coating, a coating liquid in the form of an aqueous solution or an aqueous dispersion of a crosslinked resin layer composition containing the above-mentioned series of compounds is applied onto a base film (1) such as a polyester film. It is preferable to carry out at Further, within a range that does not impair the gist of the present invention, the coating solution may contain a small amount of an organic solvent for the purpose of improving dispersibility in water, improving film-forming properties, etc. The organic solvents can be used alone or in combination of two or more.

The content of the organic solvent in the coating liquid is preferably 10% by mass or less, more preferably 5% by mass or less. Specific examples of organic solvents include aliphatic alcohols such as n-butyl alcohol, n-propyl alcohol, isopropyl alcohol, ethyl alcohol, and methyl alcohol, or alicyclic alcohols such as cyclohexanol, propylene glycol, ethylene glycol, Glycols such as diethylene glycol, glycol derivatives such as n-butyl cellosolve, ethyl cellosolve, methyl cellosolve, 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. , N-methylpyrrolidone and other amides.

Moreover, regardless of offline coating or in-line coating, in order to crosslink the crosslinked resin layer composition, heat treatment and active energy ray irradiation such as ultraviolet ray irradiation may be used in combination as necessary.

Examples of methods for forming the crosslinked resin layer include 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, Conventionally known coating methods such as impregnation coating, kiss coating, spray coating, calendar coating, and extrusion coating can be used.

(Thickness of crosslinked resin layer)
The thickness of the crosslinked resin layer is preferably 0.01 μm to 3 μm, more preferably 0.02 μm or more, from the viewpoint of exhibiting various functionalities when viewed as a final coating, and among these, 0.01 μm to 3 μm, more preferably 0.02 μm or more. The thickness is more preferably 0.03 μm or more, more preferably 1 μm or less, and even more preferably 0.3 μm or less.
The coating amount of the coating liquid containing the crosslinked resin layer composition is usually 0.01 to 3 g/m ² , preferably 0.01 to 1 g/m ² , more preferably 0.01 to 0.3 g in terms of solid content. / ^m2 . If it is 0.01 g/m ² or more, sufficient performance can be obtained in terms of antistatic performance or adhesion to the silicone pressure-sensitive adhesive layer (that is, easy adhesion performance). Further, if it is 3 g/m ² or less, the crosslinked resin layer has good appearance and transparency, and there is no risk of film blocking or a decrease in productivity due to a decrease in line speed.
In the present invention, the coating amount can be calculated from the liquid mass per coating time (before drying), coating liquid nonvolatile content concentration, coating width, stretching ratio, line speed, etc.

<Laminated film (2)>
The above-mentioned "laminated film having a functional layer" includes, for example, a release film comprising a base film and another release layer provided on one side of the base film (referred to as "laminated film (2)"). ). Another release layer is preferably provided on the silicone adhesive layer side, and the laminated film (2) is adhered to the silicone adhesive layer via the other release layer. Note that the other release layer may be a release layer other than the above-described release layer, and may be a release layer formed from a silicone release agent, for example. Note that the base film is the same as that described above as <base film>. In addition, in the following description, the base film of the laminated film (2) may be referred to as the base film (2).

As an example of the other release layer, (E') a first layer formed from a silicone composition containing as a main component a silicone polymer containing no fluorine substituent, and a second layer containing a component having a fluorine substituent. Mention may be made of structures comprising successive layers. In this configuration, the second layer is preferably a layer that contacts the silicone adhesive layer. Examples of the second layer include a layer formed from a silicone composition containing (A') a crosslinkable fluorine-containing silicone polymer as a main component.

Another example of the "other release layer" is a layer formed from a silicone composition containing (A') a crosslinkable fluorine-containing silicone polymer as a main component.

Further, as another example of the above-mentioned "other release layer", there can be mentioned a layer formed from a silicone composition containing as a main component (E') a silicone polymer that does not contain a fluorine substituent.

The above-mentioned "main component" means the component having the largest mass ratio among the constituent components.
In addition, (A') a crosslinkable fluorine-containing silicone polymer and (E') a silicone polymer not containing a fluorine substituent are as explained above, but in other release layers, (A') a crosslinkable fluorine-containing silicone polymer is used. It is not always necessary to use two or more types of silicone polymers.
Further, in the laminated film (2), another release layer is provided on one side of the base film (2), and a crosslinked resin layer composition containing a conductive polymer and a binder polymer is formed on the other side. A crosslinked resin layer may be provided.

<Resin film>
A film laminate according to another embodiment of the present invention includes the release film of the present invention described above, a silicone adhesive layer, and a resin film, and the release film of the present invention has a silicone adhesive layer. Examples include those having a structure in which resin films are directly bonded together via layers. Note that directly bonding means that the resin film itself is bonded to the silicone adhesive layer without intervening another layer such as the above-mentioned crosslinked resin layer.
As the resin film, conventionally known films such as polyester film, polyimide film, polyolefin film, etc. can be used depending on the purpose.

<Applications of film laminate>
The film laminate is preferably used for laminating vehicle-mounted members from the viewpoint that a silicone adhesive having good durability and transparency can be used.

<How to use the release film and film laminate>
Since the release film of the present invention has excellent release properties against silicone adhesives, it can be used as a light release film for silicone adhesives in the following manner.
That is, the release film of the present invention (referred to as "light release film") includes the light release film, a silicone adhesive layer, and a heavy release film, and the light release film is attached to one side of the silicone adhesive layer. A film laminate in which a heavy release film is laminated on the other side of the silicone adhesive layer, and the heavy release film has a higher peel strength (e.g., the normal peel strength described above) than the light release film. It can be used in In this film laminate, after peeling off the light release film, the exposed surface of the silicone adhesive layer is adhered to an "adherent", and if necessary, after curing the silicone adhesive layer, It can be used by peeling off the release film. That is, the film laminate having the above-mentioned laminate film (2) can be suitably used in such usage methods. However, the method of use is not limited to this method.

Examples of adherends to which the silicone adhesive layer of each film laminate is attached include various process papers, interleaf papers, and optical members. Examples of the optical member include a polarizing plate or a touch sensor. In addition, by taking advantage of the heat resistance, cold resistance, weather resistance, and high transparency of the silicone adhesive itself, it can be used for automotive applications such as touch panels installed in automobiles. is preferred.

(Silicone adhesive)
Each of the silicone adhesive layers described above is made of a silicone adhesive. The silicone adhesive may be any adhesive whose main component is silicone. The "main component resin" refers to the resin with the largest content (mass) among the resins constituting the adhesive.
Examples of the silicone adhesive include addition reaction type, peroxide curing type, and condensation reaction type silicone adhesives. Among these, addition reaction type silicone pressure-sensitive adhesives are preferably used from the viewpoint of being curable at low temperatures and in a short time. Note that these addition reaction type silicone pressure-sensitive adhesives are cured when forming the pressure-sensitive adhesive layer on the support.
When an addition reaction type silicone adhesive is used as the silicone adhesive, the silicone adhesive may contain a catalyst such as a platinum catalyst.
For example, the addition reaction type silicone adhesive is prepared by adding a catalyst such as a platinum catalyst to a silicone resin solution diluted with a solvent such as toluene as needed and stirring the mixture to make it uniform, and then applying the solution onto a support. It can be cured by heating at 100 to 130°C for 1 to 5 minutes.
Further, if necessary, a crosslinking agent and an additive for controlling adhesive strength may be added to the addition reaction type silicone adhesive, or the support may be subjected to a primer treatment before forming the adhesive layer. Good too.

Commercially available silicone resins used in the addition reaction type silicone adhesive include SD4580PSA, SD4584PSA, SD4585PSA, SD4587LPSA, SD4560PSA, SD4570PSA, SD4600FCPSA, SD4593PSA, DC7651ADHESIVE, and DC76. 52ADHESIVE, LTC-755, LTC-310 (all Toray Dow Corning), 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 manufactured by Shin-Etsu Chemical), AS-PSA001, AS-PSA002, AS-PSA003, AS-PSA004, AS-PSA005, AS-PSA012, AS-PSA014, PSA-7465 (all manufactured by Arakawa Chemical Industries, Ltd.), TSR1512, TSR1516, and TSR1521 (all manufactured by Momentive Performance Materials). However, it is not limited to these.

(Polarizer)
The material and structure of the polarizing plate are arbitrary. For example, a TAC (triacetyl cellulose) film laminated as a protective film on a stretched polyvinyl alcohol film using iodine as an alignment dye has been widely put into practical use as this type of polarizing plate.
Further, the polarizing plate may have a layer structure on its surface having functions such as a hard coat having substantially no retardation, anti-glare, low reflection, and antistatic properties.

(Touch sensor)
The above-mentioned touch sensor is a component that reacts to the touch and determines the touch point when the user touches the image displayed on the screen with a finger or touch pen. Examples include methods such as a surface wave method using infrared rays or ultrasonic waves.
Generally, a touch sensor is installed in a display device such as a liquid crystal display panel or an organic EL display.
Moreover, in recent years, there has been a trend to use a base film as a substitute for a glass substrate, focusing on flexibility, and it is preferable to use a touch sensor film.
Touch sensor films are commonly provided with a patterned transparent conductive layer to perform the function of sensing electrodes.

<Explanation of words, etc.>
In general, a "sheet" is defined by JIS as a flat product that is thin and has a small thickness relative to its length and width, and a "film" generally refers to a product that is thin and flat compared to its length and width. A thin, flat product with extremely small thickness and arbitrarily limited maximum thickness, usually supplied in roll form (Japanese Industrial Standard; JIS K6900). However, the boundary between a sheet and a film is unclear, and there is no need to distinguish between the two in terms of the wording in the present invention. Therefore, in the present invention, even when the term ``film'' is used, the term ``sheet'' is included, and the term ``sheet'' is used. "film" shall be included even if

In the present invention, when "X to Y" (X and Y are arbitrary numbers) means "more than or equal to It also includes the meaning of "less than".
In addition, when it is written as "more than or equal to X" (X is any number), it includes the meaning of "preferably greater than X" unless otherwise specified, and it is written as "less than or equal to Y" (where Y is any number). In this case, unless otherwise specified, it also includes the meaning of "preferably smaller than Y".

Hereinafter, the present invention will be explained more specifically using Examples. However, the present invention is not limited to the following examples.

<Evaluation method>
(1) Heating peeling force (No. 5413 Si adhesive tape evaluation)
One side of a silicone adhesive tape (No. 5413, manufactured by 3M) was pasted on the surface of the release layer of the sample film, cut into a size of 50 mm x 300 mm, and heated in a hot air oven at 100°C ( After heating and holding for 1 hour at 23°C and 50% RH, using a tensile tester (Shimadzu Corporation "EZ graph"), the test was conducted at a tensile speed of 300 mm/min. The 180° peel force was measured under these conditions.

(2) Adhesive peeling force (SD4580 Si adhesive evaluation)
100 parts by mass of silicone adhesive "SD4580" manufactured by Dow-Toray Co., Ltd., 50 parts by mass of toluene, and 0.9 parts by mass of platinum catalyst "NC-25" manufactured by Dow-Toray Co., Ltd. were mixed, and silicone An adhesive liquid was created. In order to stabilize the adhesive strength, coating was carried out 5 hours after the solution was prepared.
The silicone adhesive liquid was coated on a 100 μm thick PET film "T100-100" manufactured by Mitsubishi Chemical Corporation with an applicator to a coating thickness of 0.3 mm, and cured at 100° C. for 3 minutes.
After attaching the release layer side of the release film to the silicone adhesive side using a rubber roller, store it at room temperature (23°C) for 24 hours and cut it out into 2.5cm width x 15cm length. A measurement sample was obtained. Place the PET film on a SUS plate, fix the lower side with a chuck of a peel tester and the upper side with a rubber band, and apply the release film to the silicone adhesive layer using a peel tester at 180° and 0.3 m/min. The release force of the release film against the silicone adhesive was measured.

(3) Residual adhesion rate (migration performance substitute evaluation of release layer, No. 5413 Si adhesive tape evaluation)
A tape with silicone adhesive (No. 5413, manufactured by 3M Company) was pasted on the release surface of the sample film using a 2 kg rubber roller, and then cut out to a length of 50 mm x 250 mm, which was used as a sample for measuring the residual adhesion rate. . After heat treatment for 1 hour in an oven heated to 100°C, the pieces were cut into 20 mm width pieces and left at room temperature and humidity for 1 hour. The adhesive tape peeled off from the measurement sample was pressed onto a cleaned stainless steel plate (60 mm x 150 mm) using a rubber roller.
For the peeling force, 180° peeling was performed at room temperature (23° C.) at a tensile speed of 0.3 (m/min) using “EZ Graph” manufactured by Shimadzu Corporation. Then, by substituting the peeling force of the evaluation film for the measured residual adhesion rate and the peeling force of the reference film (sample made by laminating No. 5413 tape to NAFLON tape instead of the sample film) into the following equation, the residual adhesion rate ( %) was calculated.
Residual adhesion rate (%) = Peeling force of migration evaluation film / Peeling force of reference film x 100

(4) Fluorine atom concentration in the thickness direction in the release layer (atom%)
Using GC-IB (gas cluster ion beam) for XPS (X-ray photoelectron spectroscopy), carbon (C) and oxygen were detected in the thickness direction of the release layer of the sample film under a constant sputtering speed (sputtering condition settings). The concentration distribution (ratio) of (O), silicon (Si), and fluorine (F) atoms was measured.
In the fluorine atom concentration distribution, when the fluorine atomic ratio at the outermost surface (sputtering time 0) is taken as a reference, the sputtering time (t1 [75%]) required for the fluorine atomic ratio to decrease to 75% of the outermost surface, and the fluorine atomic ratio The ratio t _d (t1 [75%]/t2 [50%]) to the time for the atomic ratio to decrease to 50% of the outermost surface (t2 [50%]) was calculated in percentage (%).
In addition, the atomic ratio (atom%) of fluorine (F) on the surface of the release layer was determined. Note that the fluorine (F) atomic ratio is the ratio (atom%) of the amount of fluorine (F) atoms to the total amount of carbon (C), oxygen (O), silicon (Si), and fluorine (F) atoms. .

At this time, the XPS setting conditions are as follows.
Equipment: Shimadzu KRATOS ULTRA2
=Analysis conditions=
X-ray intensity: AlKα/15kV/375W
Measurement range: 110μΦ
Pass energy: 40eV
Charge correction: 284.6eV (C1s)
= Sputtering conditions =
Ar-GCIB
Ar3000+
5kV, 70 minutes (2 minute intervals, 35 levels)

<Example 1>
(X) As a fluorine segregation promoter, mix the following (A1) crosslinkable fluorine-containing silicone polymer, the following (B1) silicone crosslinking agent that does not contain fluorine substituents, the following (C1) curing catalyst (platinum catalyst 1) and diluent solvent. A solution a1 was prepared. The solution a1 was stirred for 1 minute so as to be uniform, and left to stand for 45 minutes to sufficiently perform a preliminary reaction in the liquid (pretreatment). Thereafter, the following solution b1 ((A2) crosslinkable fluorine-containing silicone polymer + (C2) curing catalyst (platinum catalyst 2)) and the following solution c1 ((E1) curable silicone not containing fluorine substituents + (C2) curing catalyst (Platinum catalyst 2)) were mixed so that the mass ratio (solution a1: solution b1: solution c1) was 0.9:0.1:2, and coating liquid A1 with a solid content concentration of 3.6% by mass was prepared. Created. Then, the coating liquid A1 was applied to one side of the base film (PET film manufactured by Mitsubishi Chemical Corporation ("T100-38", thickness 38 μm)). 4 bar, and was cured by heat treatment at 150° C. for 15 seconds to obtain a release film (sample film) provided with a release layer. The results evaluated using the above method are shown in Table 1 and FIG. 1.
(Release layer composition)
Solution a1:
(A1) 100 parts by mass of crosslinkable fluorine-containing silicone polymer (Dow-Toray Co., Ltd. "3062", 10% by mass) (B1) Silicone cross-linking agent that does not contain fluorine substituents (Toray-Dow Corning Co., Ltd. "3062A") ) 0.50 parts by mass (C1) Platinum catalyst 1
(Dow Corning Toray Co., Ltd. "FS
Solution b1:
(A2) 100 parts by mass of crosslinkable fluorine-containing silicone polymer (“X-70-201S” manufactured by Shin-Etsu Chemical Co., Ltd., 15% by mass, containing a silicone crosslinking agent containing a fluorine substituent) (C2) Platinum catalyst 2 (Shin-Etsu Chemical Co., Ltd.) Co., Ltd. "CAT-PL-50T") 0.5 parts by mass Diluent: diisopropyl ether/ethyl acetate/cyclohexanone (6:4:0.2)
Solution c1:
(E1) 100 parts by mass of curable silicone that does not contain fluorine substituents ("KS-847H" manufactured by Shin-Etsu Chemical Co., Ltd., solvent type, 30% by mass, contains crosslinking agent/reaction control agent) (C2) Platinum catalyst 2 ( "CAT-PL-50T" manufactured by Shin-Etsu Chemical Co., Ltd.) 0.5 parts by mass Diluent: diisopropyl ether/ethyl acetate/cyclohexanone (6:4:0.2)

<Examples 2 to 6>
A release film (sample film) was obtained in the same manner as in Example 1 except that the mixing ratio of solution a1 and solution b1 was changed. Table 1 shows the results of evaluation using the above method. Further, the fluorine atom concentration distribution profiles in the thickness direction in the release layer in the release films of Examples 5 and 6 are shown in FIGS. 2 and 3.

<Comparative example 1>
A release film (sample film) was obtained in the same manner as in Example 1, except that solution a1 and solution c1 were mixed at a mass ratio of 1:2. The results evaluated using the above method are shown in Table 1 and FIG. 4.

<Comparative example 2>
A release film (sample film) was obtained in the same manner as in Example 1, except that solution b1 and solution c1 were mixed at a mass ratio of 1:2. The results evaluated using the above method are shown in Table 1 and FIG. 5.

<Comparative example 3>
A release film (sample film) was obtained in the same manner as in Example 1 except that solution b1 was used alone. The results evaluated using the above method are shown in Table 1 and FIG. 6.

<Consideration>
From the test results of the above examples and comparative examples, it is clear that the release layer formed on at least one side of the base film is (A') a crosslinkable fluorine-containing silicone polymer, (E') a silicone polymer that does not contain a fluorine substituent, and (X) A release film having a release layer formed by curing a release layer composition containing a fluorine segregation promoter has excellent light releasability that is easy to peel off from a silicone adhesive layer, and low migration properties. It was found that it has.
Moreover, when we investigate the common features of such release layers, we find that in the concentration distribution of fluorine atoms in the thickness direction within the release layer, we find that fluorine is efficiently unevenly distributed on the surface side of the release layer. did it.
From the fluorine atom concentration distribution profiles (Figures 1, 2, and 3) in the release films of Examples 1, 5, and 6 above, it can be seen that at appropriate blending ratios (conditions), the release films of Examples can release fluorine. It can be seen that it is unevenly distributed on the surface side of the mold layer. On the other hand, the fluorine atom concentration distribution profile (FIG. 5) in the release film of Comparative Example 2 demonstrated that the degree of uneven distribution of fluorine was low.
Also, when the fluorine atomic ratio on the outermost surface (sputtering time 0) is taken as a reference, the sputtering time (t1 [75%]) required for the fluorine atomic ratio to decrease to 75% of the outermost surface and the maximum fluorine atomic ratio The ratio (t1 [75%]/t2 [50%]) to the time required for the surface to decrease to 50% (t2 [50%]) is smaller in the release layer made of a mixture of two types of crosslinkable fluorine-containing silicone polymers. Ta. In other words, the fluorine atom concentration decreases quickly in the initial stage of etching. On the other hand, in the release layer made of only one type of crosslinkable fluorine-containing silicone polymer, the ratio (t1 [75%]/t2 [50%]) was large. That is, the difference in fluorine atom concentration between the surface of the mold release layer and the inside of the mold release layer, which does not contribute to easy releasability, became smaller.

On the other hand, the following was found in the above method for forming a release layer.
When a release layer composition containing (A') a crosslinkable fluorine-containing silicone polymer, (E') a silicone polymer containing no fluorine substituents, and (X) a fluorine segregation promoter is coated on a film and dried, It is inferred that the hydrophobic fluorine substituents tend to segregate toward the surface (air interface) side.
In the present invention, first, (A') a crosslinkable fluorine-containing silicone polymer, (B) a silicone crosslinking agent, and (C) a curing catalyst are mixed and reacted by stirring and/or standing. , the pretreatment composition obtained in the pretreatment, so-called "fluorine segregation promoter", and (A') a crosslinkable fluorine-containing silicone polymer (E') a curable silicone polymer that does not contain fluorine substituents are mixed. When a release layer composition was prepared, it exhibited light releasability that made it easier to peel off from silicone adhesives. However, it was found that it was possible to form a coating film with low migration properties.
Although the details of this mechanism are unknown, it is presumed that moderate entanglement (pre-crosslinking) occurs in the blended solution over time after the preparation of the blended solution of component (X). Accordingly, component (X) is more strongly segregated on the surface of the release layer. In addition, since the component (X) has a high affinity with the crosslinkable fluorine-containing silicone polymer (A'), even if the component (A') is a crosslinkable fluorine-containing silicone polymer, the segregation on the surface of the release layer is weak. It is surmised that more of it tends to exist on the surface of the release layer (air interface) together with the other components.
Furthermore, (E') a curable silicone that does not contain a fluorine substituent has excellent flexibility related to easy releasability, compared to a curable silicone that has a fluorine substituent (A'). It is presumed that for the above reasons, it became possible to form a coating film with a release layer having excellent easy releasability with respect to silicone adhesives.

Claims (24)

A release layer composition comprising (A) a crosslinkable fluorine-containing polymer, (E) a polymer containing no fluorine substituents, and (X) a fluorine segregation promoter. The release layer composition according to claim 1, wherein the (X) fluorine segregation promoter is a pre-treated composition in which a crosslinking reaction has been performed in advance in a compounded solution containing (A) a crosslinkable fluorine-containing polymer. . A release film comprising a base film and a release layer provided on at least one side of the base film, wherein the release layer is a release layer obtained by curing the release layer composition according to claim 1. type film. The release film according to claim 3, wherein the fluorine atom content in the release layer is from 3,000 mol ppm to 900,000 mol ppm. The release layer according to claim 3, wherein the fluorine atom concentration distribution ratio t _d (t1 [75%]/t2 [50%]) calculated by the following method in the thickness direction of the release layer is 1 to 70%. type film.
Calculation method of fluorine atomic concentration distribution ratio: Based on the fluorine atomic ratio at the outermost surface (sputtering time 0), the sputtering time (t1 [75%]) required for the fluorine atomic ratio to decrease to 75% of the outermost surface, The ratio t _d (t1 [75%]/t2 [50%]) to the sputtering time (t2 [50%]) at which the fluorine atomic ratio decreases to 50% of the outermost surface is calculated in percentage (%). The release film according to claim 3, wherein the release layer has a heat peeling force of 65 mN/cm or less and a residual adhesion rate of 85% or more. 2. The method for producing a release layer composition according to claim 1, wherein (X) a fluorine segregation promoter is mixed with (A) a crosslinkable fluorine-containing polymer and (E) a polymer containing no fluorine substituents. The (X) fluorine segregation promoter is obtained by stirring and/or standing still after mixing (A) a crosslinkable fluorine-containing polymer, (B) a silicone crosslinking agent, and (C) a curing catalyst. A method for producing a release layer composition according to claim 7. 9. The method for producing a release layer composition according to claim 8, wherein the stirring and/or standing is performed for 10 seconds or more. 9. The method for producing a release layer composition according to claim 8, wherein a silicone crosslinking agent containing no fluorine substituents is used as the silicone crosslinking agent (B). A method for producing a release film, comprising applying a release layer composition obtained by the method for producing a release layer composition according to any one of claims 7 to 10 on at least one side of a base film. The release film according to any one of claims 3 to 6, a silicone adhesive layer, and a laminated film having a functional layer, wherein the release film and the laminated film having the functional layer are made of a silicone adhesive. A film laminate made by bonding layers together. The film laminate according to claim 12, wherein the laminate film having a functional layer includes a base film and a crosslinked resin layer provided on at least one side of the base film. The film laminate according to claim 13, wherein the crosslinked resin layer is formed from a crosslinked resin layer composition containing a conductive polymer and a binder polymer. The film laminate according to claim 13, wherein the crosslinked resin layer is an easily adhesive layer to the silicone adhesive layer. The film laminate according to claim 12, wherein the laminate film having a functional layer includes a base film and another release layer provided on one side of the base film. The other release layer comprises (E) a first layer formed from a silicone composition containing as a main component a polymer not containing a fluorine substituent, and a second layer containing a component having a fluorine substituent, sequentially. The film laminate according to claim 16, comprising the following configuration. The film laminate according to claim 16, wherein the other release layer is formed from a silicone composition containing (A') a crosslinkable fluorine-containing silicone polymer as a main component. 17. The film laminate according to claim 16, wherein the other release layer is formed from a silicone composition containing as a main component a silicone polymer that does not contain (E') fluorine substituents. The release film according to any one of claims 3 to 6, a silicone adhesive layer, and a resin film are provided, and the resin film is directly bonded to the release film via the silicone adhesive layer. film laminate. The release film according to any one of claims 3 to 6, a silicone adhesive layer, and a heavy release film, the release film being placed on one side of the silicone adhesive layer, and the heavy release film is laminated on the other side of the silicone adhesive layer, and the heavy release film has a higher peel strength than the release film, and the method includes: after the release film is peeled off. . A method of using a film laminate, which comprises adhering the exposed surface of the silicone adhesive layer to an adherend, and then peeling off the heavy release film. The method of using a film laminate according to claim 21, wherein the adherend is an optical member. The method of using a film laminate according to claim 22, wherein the optical member is a polarizing plate or a touch sensor. 23. The method of using a film laminate according to claim 22, wherein the optical member is an in-vehicle optical member.