KR20240005214A - Layered film, release film, and layered body - Google Patents

Abstract

A laminated film having excellent peelability for adhesive layers having strong adhesive properties such as silicone adhesives is provided. The laminated film is a laminated film in which an A layer and a B layer are laminated on at least one side of a polymer film in this order, wherein both the A layer and the B layer contain fluorine atoms, and the B layer contains a fluorine atom content ratio. It is characterized by a higher fluorine atom content than the A layer.

Description

Laminated film, release film and laminate {LAYERED FILM, RELEASE FILM, AND LAYERED BODY}

The present invention relates to a laminated film, and particularly to a laminated film having release properties.

Recently, the number of cars equipped with liquid crystal panels is increasing. In such vehicle-mounted applications, the adhesive is often exposed to high or low temperatures for long periods of time, and the adhesive for bonding the panel constituent members is also required to have high weather resistance and heat resistance. As a suitable adhesive for this purpose, highly adhesive silicone adhesives are attracting attention.

Silicone adhesives are used in the form of a tape (film) as an adhesive layer, but are usually stored with one or both sides covered with a release film before use, and are used by peeling off the release film at the time of use. However, the highly adhesive silicone adhesive (adhesive layer) adheres strongly to the widely used organosilicone-coated release film, which poses a problem in that it becomes difficult to peel off the release film during use.

A fluorinated silicone material having a fluorine substituent has been proposed as a method for demonstrating peelability from a molded product made by molding a mold resin such as a silicone resin composition (Patent Document 1).

Japanese Patent Laid-Open No. 2011-201035

However, when a fluorinated silicone material is used as the release layer, the adhesion between the polymer film and the release layer becomes insufficient, causing interlayer peeling, or the release layer is not formed uniformly, resulting in deterioration of the peelability to the adherend. I was able to see an example of this happening.

The present invention was made in consideration of the above-mentioned circumstances, and its object is to provide a release film having excellent peelability for an adhesive layer having strong adhesiveness such as a silicone adhesive.

In order to solve the above problems, the present inventors have conducted intensive studies and found that, in addition to containing fluorine atoms in each layer of a laminated film in which the A layer and the B layer are laminated in this order on at least one side of the polymer film, It was discovered that the above problem could be solved by controlling the fluorine atom content ratio of both layers, and the present invention was completed.

That is, the gist of the present invention is a laminated film in which an A layer and a B layer are laminated in this order on at least one side of a polymer film, wherein both the A layer and the B layer contain fluorine atoms, and the B layer It is a laminated film characterized in that the fluorine atom content rate is greater than the fluorine atom content rate of the A layer.

Furthermore, the gist of the present invention is a laminated film in which an A layer and a B layer are laminated in this order on at least one side of a polymer film, wherein the B layer contains a fluorine atom and is in the state when measured by the following method. It is a laminated film characterized by a peeling force of 100 mN/cm or less.

<Measurement of state peeling force>

A tape with a silicone adhesive (made by 3M Japan, No 5413 tape, 50 mm wide) was bonded to the surface of layer B of the laminated film, and a 180° peel test was performed under the condition that the peel speed was 0.3 m/min.

According to the present invention, it is possible to obtain a laminated film having excellent peelability against an adhesive layer having strong adhesiveness such as a silicone adhesive.

1 is a schematic diagram of the laminated film of the present invention.
Figure 2 is a schematic diagram showing the peeling state of the silicone adhesive layer in the laminated films of the prior art (a) and the present invention (b).

Hereinafter, embodiments of the laminated film of the present invention will be described in more detail.

As illustrated in FIG. 1, the laminated film of the present invention is a laminated film in which a layer A (undercoat layer) and a layer B (release layer) are laminated in this order on at least one side of a polymer film.

The laminated film of the present invention is described below in the following order: polymer film, A layer (undercoat layer), and B layer (release layer).

1. Polymer film

As a polymer film that serves as a base material for the laminated film of the present invention, a film formed of polymers such as polyethylene, polypropylene, polyester, polystyrene, polycarbonate, polyethersulfone, polyamide, and polyimide in the form of a film. I can hear it. Additionally, as long as film formation is possible, it may be a mixture of these materials (polymer blend) or a composite of structural units (copolymer).

In addition, the polymer film is not particularly limited as long as it is formed into a film. It may be an unstretched film or a stretched film, but it is preferable that it is a stretched film stretched in a uniaxial direction or a biaxial direction. Among them, biaxially stretched films are more preferable from the viewpoint of balance of mechanical properties and planarity.

The thickness of the polymer film constituting the laminated film in the present invention is not particularly limited as long as it is within the range that can be formed as a film, but is preferably 5 μm or more and 1000 μm or less, and more preferably 10 μm or more or 500 μm or less, 15㎛ or more or 200㎛ or less is more preferable.

Among the films exemplified above, polyester films are preferable because they are excellent in physical properties such as heat resistance, planarity, optical properties, and strength, and among them, biaxially oriented polyester films are particularly preferable.

The polyester film may be a single layer or a multilayer film (laminated film) having two or more layers with different properties.

In the present invention, the polyester used for the polyester film may be homopolyester or copolyester. As homopolyester, one obtained by polycondensing aromatic dicarboxylic acid and 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. You can.

Representative homopolyesters include polyethylene terephthalate (PET), polyethylene naphthalate (PEN), and polybutylene terephthalate (PBT). On the other hand, examples of the dicarboxylic acid component of the copolyester include one or two or more of isophthalic acid, phthalic acid, terephthalic acid, 2,6-naphthalenedicarboxylic acid, adipic acid, and sebacic acid, and as a glycol component, , ethylene glycol, diethylene glycol, propylene glycol, 1,4-butanediol, 1,4-cyclohexanedimethanol, and neopentyl glycol.

Among them, in the present invention, polyethylene terephthalate is preferred, wherein usually 60 mol% or more, preferably 80 mol% or more, is ethylene terephthalate unit.

In the present invention, the surface of the polymer film is provided with antistatic properties, sealing properties against exudation (bleed, plate out) of compounds or oligomers on the film surface, and the light transmittance of the film or A as described later. In order to improve adhesion to the layer (undercoat layer), an undercoating layer (base coating layer) may be provided.

The undercoat layer may be formed by either an in-line coating method in which the undercoat layer is formed simultaneously with the formation of the polymer film, or an offline coating method in which a separate undercoat layer is formed on the film after film formation.

When providing the undercoat layer, it may be formed on at least one side of the polymer film. When forming on both sides, the same undercoat layer may be formed on both sides, or a different undercoat layer may be formed on each side. The undercoating layer may be any of a layer made of an organic material, a layer made of an inorganic film, or a layer made of a mixture of an organic material and an inorganic material.

2. A layer (undercoating layer)

In the present invention, an A layer (undercoating layer) is provided on at least one side of the polymer film.

<Configuration of A-floor>

The A layer usually contains fluorine atoms. Accordingly, not only does it have adhesion between the A layer and the B layer described later, but when used as a release film, light peelability between the B layer and the adhesive layer that is the adherend is exhibited, making it easy to peel off the adherend.

There is no limitation on the method of containing a fluorine atom in the A layer, and at least a compound containing a fluorine atom may be contained in the A layer. Specifically, low molecular weight compounds containing a fluorine atom, resins containing a fluorine atom, etc. can be mentioned. Among these, it is preferable to use a resin containing a fluorine atom, and it is especially preferable that the resin is curable.

Additionally, when used as a release film, by laminating the B layer on the A layer, the peeling force against the adherend is reduced and easy peelability can be achieved. According to the present inventor, when the layer A is not laminated on the laminated film, the adherend (adhesive) also follows the direction of peeling when the laminated film is peeled, so a greater force is required to peel from the adherend, and peeling occurs. It was assumed that it was difficult to do (medium peeling) (Figure 2(a)). On the other hand, as in the present invention, when the A layer containing fluorine atoms is laminated on the laminated film, because the A layer is relatively flexible, the A layer acts like a cushion when peeled, preventing deformation of the adherend. Because it is suppressed, it is assumed that peeling from the adherend can be done with less force, making peeling easier (light peeling) (Figure 2(b)).

<Fluorine atom content ratio in A layer>

The A layer contains a material containing a fluorine atom, and the fluorine atom content ratio (atomic number fraction) for the entire A layer is preferably 50 ppm or more, more preferably 500 ppm or more, from the viewpoint of adhesion and easy peelability. , 1,000 ppm or more is more preferable, and 50,000 ppm or more is particularly preferable. On the other hand, the upper limit is not particularly limited, but is preferably less than 900,000 ppm, more preferably 800,000 ppm or less, and still more preferably 700,000 ppm or less.

The fluorine atom content ratio of the A layer can be confirmed, for example, by performing depth direction analysis by spectro etching in the vicinity of the polymer film in the undercoat layer constituting the laminated film using X-ray photoelectron spectroscopy (XPS method). . The fluorine atom content ratio of the A layer can also be quantified by using as a reference a material (such as fluorinated silicon) whose fluorine atom content ratio is previously known. In addition, when confirming by the XPS method, the ratio of fluorine to all elements except hydrogen and helium was referred to as the fluorine atom content ratio.

By keeping the fluorine atom content ratio of the A layer within the above range, the B layer (release layer), which also contains fluorine atoms, can be uniformly applied when preparing it on the A layer by a coating method, and the Adhesion between the A layer and the B layer can also be increased.

In addition, if the above-mentioned fluorine atom content ratio is achieved in the entire A layer, the resin used in the A layer may be used alone as a resin containing a fluorine atom, or may be used in combination with a resin that does not contain a fluorine atom (non-fluorinated resin).

Additionally, the A layer may have a composition in which the fluorine atom content ratio is inclined in the thickness direction. The same applies to the B layer, which will be described later.

<Resin containing fluorine atoms>

Examples of the resin containing a fluorine atom used in the present invention include a resin containing a fluorine atom in the side chain portion of the resin skeleton. Specific examples of the resin containing a fluorine atom include, in addition to fluorinated silicone resins, fluorinated hydrocarbon resins such as polytetrafluoroethylene, and various other fluorinated resins. Among these, fluorinated silicone resins are preferred from the viewpoint of peelability. is desirable.

As the fluorinated silicone resin, both curable and non-curable resins can be used without particular limitation. Among them, curable fluorinated silicone resin is preferable because it forms a stronger layer. Additionally, the fluorinated silicone resin may be of a solvent type, a non-solvent type, or a mixture of these. A curable fluorinated silicone resin usually has a functional group bonded thereto, such as an alkenyl group or a hydrosilyl group, that can form a crosslinked structure by reacting (curing).

Examples of the curable fluorinated silicone resin include KP-911 and X-70-201S manufactured by Shin-Etsu Chemical Co., Ltd.; Examples include FS1265-300CS, FS1265-1000CS, FS1265-10000CS, BY24-900, BY24-903, Syl-off 3062, and Q2-7785 manufactured by Toray Dow Corning Co., Ltd.

Additionally, the fluorine atom content ratio (atomic number fraction) of the fluorinated silicone resin is generally on the order of several thousand ppm to several tens of percent.

<Resin not containing fluorine atoms>

Resins (non-fluorinated resins) that do not contain fluorine atoms used in the present invention include silicone resins, polyolefin resins, and acrylic resins. Among these, resins containing fluorine atoms are compatible with fluorinated silicone resins, in particular. From this point of view, silicone resins are preferable (in the present invention, silicone resins that do not contain fluorine atoms are sometimes referred to as “non-fluorinated silicone resins”). In addition, the non-fluorinated resin may be either curable or non-curable, or a mixture of both may be used. Like curable fluorinated silicone resins, non-curable fluorinated silicone resins also usually contain functional groups such as alkenyl groups and hydrosilyl groups that can form a crosslinked structure by reacting (curing).

hardenability Non-fluoridated silicone resin

The curable non-fluorinated silicone resin may be of a solvent type or a non-solvent type.

Specific examples of curable non-fluorinated silicone resins include KNS-3051, KNS-320A, KNS-316, KNS-3002, KNS-3300, 837, 62-2825, X-62-9201-A, X-62-9201B, KM3951, KM-768, 62-7028-B, X-62-7052, X-62-7622, X-62-7660, X-62-7655; Toray Dow Corning Co., Ltd. SP7017, SP7015, SP7025, SP7031, LTC1006L, LTC1063L, LTC1036M, LTC1056L, SRX357, SRX211, SRX345, SRX370, LTC300B, LTC310, LTC355A, LTC759, L TC755, LTC750A, LTC752, LTC761, LTC856 , LTC851, etc.

Additionally, a heavy release additive may be added to the curable non-fluorinated silicone resin, examples of which include KS-3800 manufactured by Shin-Etsu Chemical Co., Ltd.; Examples include SD7292 and BY24-4980 manufactured by Toray Dow Corning Co., Ltd.

In addition, the above curable non-fluorinated silicone may be used alone, or two or more different types may be mixed and used. By mixing two or more types of curable non-fluorinated silicones, the curing reaction can be adjusted, the coating liquid viscosity of the A layer can be adjusted, and the wettability and reactivity of the B layer can be further increased. At that time, non-solvent type silicones may be mixed, solvent type silicones may be mixed, or solvent free type silicones and solvent type silicones may be mixed. In particular, when the film thickness of the A layer is increased in order to obtain a release film that is more easily peeled, the solid content concentration of the coating liquid forming the A layer tends to increase. For this reason, the viscosity of the coating liquid increases, and problems such as deterioration of the coating appearance or increased thickness unevenness may occur. Therefore, by mixing non-solvent type silicone and solvent type silicone, the viscosity of the coating liquid can be reduced and an A layer with a good coating appearance and small thickness unevenness can be formed.

Here, “solvent-free silicone” is a silicone with a viscosity that can be coated even without diluting with a solvent, and is made up of short polysiloxane chains and has a relatively low molecular weight.

The viscosity of the non-solvent type silicone at 100% concentration is preferably less than 1000 mPa·s, especially 50 mPa·s or more or 900 mPa·s or less, and especially 80 mPa·s or more or 800 mPa. ·s or less is more preferable.

On the other hand, “solvent-type silicone” is a silicone that has a viscosity so high that it cannot be coated unless diluted with a solvent, and is a silicone that has a relatively high molecular weight.

The viscosity of the solvent-type silicone when used as a 30% toluene solution is preferably 1000 mPa·s or more, especially 2000 mPa·s or more or 20000 mPa·s or less, and especially 3000 mPa·s or more or 18000 mPa·s or less. desirable.

Non-hardening Non-fluoridated silicone resin

By including a non-curable non-fluorinated silicone resin in the A layer, the controllability of the curing reaction can be improved, and sufficient flexibility is provided to the A layer, and the storage stability of the laminate laminated with the laminated film and the adhesive layer is also improved. It gets better. As the non-curable non-fluorinated silicone resin, the non-fluorinated silicone resins listed above that do not have a reactive functional group can be used without particular limitation. Specifically, organopolysiloxane represented by the following general formula (I) is preferable.

R ₃ SiO(R ₂ SiO) _m SiR ₃ … … (I)

(In the formula, R represents the same or different monovalent hydrocarbon group without an aliphatic unsaturated bond, and m represents a positive integer.)

The mass mixing ratio of the curable silicone resin (total of fluorinated and non-fluorinated) and the non-curable non-fluorinated silicone resin is preferably within the range of 1:1000 to 1000:1, and more preferably within the range of 1:100 to 100:1. It is preferable, and it is more preferable that it is within the range of 1:50 to 50:1. Particularly preferable is the range of 1:20 to 20:1, with 1:1 to 20:1 being particularly preferable.

The film thickness of layer A is preferably 10 nm or more and 100 μm or less, more preferably 20 nm or more and 10 μm or less, and still more preferably 50 nm or more and 1 μm or less. A particularly preferable range is 80 nm or more and 800 nm or less.

When this film thickness is excessively thin, such as less than 10 nm, not only the adhesion between the A layer and the B layer deteriorates, but also the peelability between the silicone adhesive layer and the B layer of the laminated film tends to deteriorate. On the other hand, when the film thickness of the A layer is too thick, the amount of material used increases, and it is difficult to obtain an increase in effect commensurate with the increase in the amount used.

3. B layer (release layer)

<Configuration of B-floor>

As a material for forming the B layer (release layer), a resin containing the same fluorine atoms as the base material for the above-described A layer (undercoat layer) can be similarly used. Among them, from the viewpoint of release properties from the adherend, fluorinated silicone resin is preferable, and curable fluorinated silicone resin is especially preferable. By using a curable fluorinated silicone resin for the B layer (release layer), a release film with stable peelability from the silicone adhesive layer can be obtained.

The B layer may be formed of the curable fluorinated silicone resin alone, or may be formed of a mixture of a plurality of materials, such as mixed with a curable non-fluorinated silicone resin.

It is particularly preferable that the coating liquid for forming the B layer contains a fluorine-based solvent containing a fluorine atom for the purpose of increasing wettability to the A layer.

If the film thickness of the B layer is too thin, it may be difficult to obtain the effect of the present invention, and on the other hand, if it is too thick, it may be difficult to obtain an increase in effect commensurate with the increase in the amount of material used.

The lower limit of the film thickness of layer B is preferably 5 nm or more, more preferably 10 nm or more, and particularly preferably 20 nm or more. Moreover, the upper limit is preferably 50 μm or less, more preferably 1 μm or less, and especially preferably 500 nm or less.

<Fluorine atom content ratio in B layer>

In the laminated film of the present invention, a B layer (release layer) is formed on the A layer (undercoat layer). Preferred materials for this B layer are the same as those described in the description of the A layer above, but from the viewpoint of adhesion and easy peelability, the B layer has a higher fluorine atom content per unit volume than the A layer. need.

In the present invention, the lower limit of the fluorine atom content ratio (atomic number fraction) contained in the B layer measured by SIMS method or the like is preferably 3,000 ppm or more, more preferably 5,000 ppm or more, and even more preferably 10,000 ppm or more. And, 20,000 ppm or more is particularly preferable. Meanwhile, the upper limit is not particularly limited, but is preferably 900,000 ppm or less, more preferably 800,000 ppm or less, and especially preferably 700,000 ppm or less.

The fluorine atom content ratio of the B layer can be confirmed, for example, by secondary ion mass spectrometry (SIMS method) or X-ray photoelectron spectroscopy (XPS method) on the surface of the release layer of the laminated film. The fluorine atom content ratio of the B layer can also be quantified by using as a reference a material (such as fluorinated silicon) whose fluorine atom content ratio is known in advance. In addition, when confirming by the XPS method, the ratio of fluorine to all elements except hydrogen and helium was referred to as the fluorine atom content ratio.

Above, the case where layers A and B with different fluorine atom content ratios are sequentially laminated has been described. However, in one lamination process, the fluorine atom content ratio in the layer has an inclined structure in the thickness direction (inclined composition). By devising as much as possible, there are cases where a structure substantially equivalent to the above-described lamination structure of the A layer and the B layer can be obtained. For example, a resin containing a fluorine atom and a resin not containing a fluorine atom are diluted in a solvent to form a coating solution, and the coating solution is applied to at least one side of a polymer film and dried to form a resin containing a fluorine atom. A method of forming a layer by concentrating it on the surface of the layer and having an inclined structure in the thickness direction is an example. When such a stacking process can be used, it is not necessarily limited to a means of sequentially stacking the A layer and the B layer in stages, and the interface between the two layers does not necessarily have to be clear, and the surface side of one layer is the B layer. , if the polymer film side is the A layer and has substantially the same structure, it is included in the present invention.

By making the A layer and the B layer into an inclined structure in this way, it can be expected to substantially improve the adhesion of the interface between the A layer and the polymer film or the interface between the A layer and the B layer. Furthermore, since the fluorine atom content ratio of the B layer surface can be increased, light peelability may be further improved while suppressing the content of the resin containing fluorine atoms in the entire laminated film to a low level.

4. Fluorine atom content ratio

In the present invention, from the viewpoint of adhesion and easy peelability, in addition to the fact that both layers A and B contain fluorine atoms, the content ratio is methylsiloxane ion (CH ₃ SiO) of the silicone resin that serves as the base material of each layer. _2- ⁾ It is desirable to have a specific relationship with the content ratio.

That is, the ratio between the fluorine ion content ratio and the methylsiloxane ion content ratio calculated by the SIMS method, etc. ([F ^- ]/[CH ₃ SiO ₂ ^- ]) (hereinafter referred to as the "fluorine atom content ratio") (abbreviated) is preferably larger than the fluorine atom content ratio of the A layer.

In addition, the fluorine atom content ratio of each of the A layer and the B layer is preferably 1 or more and 1,000 or less in the A layer, and 3 or more and 5,000 or less in the B layer.

The lower limit of the more preferable fluorine atom content ratio of the B layer is preferably 5 or more, more preferably 10 or more, and still more preferably 20 or more. Additionally, the upper limit is preferably 3,000 or less, and a more preferable upper limit is 1,000 or less.

The fluorine atom content ratio of the B layer is preferably 1.1 times or more, more preferably 1.5 times or more, and still more preferably 2 times or more than the fluorine atom content ratio of the A layer from the viewpoint of easy peelability with the silicone adhesive layer. , 3 times or more is particularly preferable, and 5 times or more is most preferable. On the other hand, the upper limit is not particularly limited, but from the viewpoint of adhesion between the A layer and the B layer, 1000 times or less is preferable, and 100 times or less is more preferable.

In the present invention, the fluorine atom content ratio (atomic number fraction) in the B layer is preferably 1.1 times or more than the fluorine atom content ratio (atomic number fraction) in the A layer from the viewpoint of easy peelability with the silicone adhesive layer, 1.5 times or more is more preferable, 2 times or more is more preferable, 3 times or more is particularly preferable, and 5 times or more is most preferable. On the other hand, the upper limit is not particularly limited, but from the viewpoint of adhesion between the A layer and the B layer, 1000 times or less is preferable, and 100 times or less is more preferable.

Here, “fluorine atom content ratio (atomic number fraction)” means the ratio of fluorine atoms to the layer. In the case where both the A layer and the B layer are substantially composed of silicone resin (including fluorinated, non-fluorinated, curable, and non-curable), the above "fluorine atom content ratio" and "fluorine atom content ratio ( Regarding the atomic number fraction), the ratio between the A layer and the B layer is the same value.

By setting the fluorine atom content ratio of the B layer within the above range, sufficient adhesion can be obtained between the A layer and the B layer, and good peelability between the B layer and the silicone adhesive layer can be achieved.

In addition, since the fluorine atom content ratio and/or the fluorine atom content ratio of the B layer is higher than that of the A layer, sufficient adhesion between the A layer and the B layer is obtained, and good peelability between the B layer and the silicone adhesive layer is stably exhibited. can do.

In addition, the fluorine atom content ratio or the fluorine atom content ratio of the A layer and the B layer can be calculated by analyzing the structure of the coating agent using nuclear magnetic resonance spectroscopy (NMR), or even after layer formation, secondary ion mass spectrometry ( It can be quantified by SIMS method) or X-ray electron spectroscopy (XPS method).

In measurements by the SIMS method or the

In cases where fluorine atoms do not exist uniformly in each of layer A and layer B (for example, in the case of the above-described inclined structure), the total amount of fluorine atoms contained in each layer measured by the SIMS method, etc. The fluorine atom content ratio per unit volume divided by the volume can be defined as the fluorine atom content ratio of each layer A and B.

<Other mixing agents>

Regarding the A layer and the B layer, it is preferable that the coating liquid containing the curable non-fluorinated silicone resin and the curable fluorinated silicone resin contains a crosslinking agent, a catalyst, and a reaction initiator (reaction accelerator). Additionally, commercially available paints containing curable silicone resins may initially contain a crosslinking agent or catalyst.

When forming the A layer and the B layer, it is preferable that a crosslinking agent is included in order to form a crosslinked structure by reacting with the reactive functional group contained in the resin. Examples of the crosslinking agent include vinylsiloxane and organosiloxane having a hydrosiloxane moiety. Specific examples of the crosslinking agent include SP7297, 7560, 3062A, 3062B, 3062C, and 3062D manufactured by Toray Dow Corning Co., Ltd.

Additionally, the crosslinking agent may contain a portion having a fluorine substituent, or a silane coupling agent having a fluorinated substituent, etc. may be used.

In addition, when forming the A layer and the B layer, it is preferable that a catalyst that promotes the addition reaction is contained, and it is especially preferable that a platinum catalyst is contained. Examples of the platinum catalyst include platinum-based compounds such as chloroplatinic acid, alcohol solution of chloroplatinic acid, complex of chloroplatinic acid and olefin, complex of chloroplatinic acid and alkenylsiloxane, platinum black, platinum-supported silica, and platinum-supported activated carbon. The platinum catalyst may be used alone or in combination of two or more types.

Specific examples of the catalyst include CAT PL-50T manufactured by Shin-Etsu Chemical Co., Ltd., SRX212, SRX212P, NC-25, and FS XK-3077 manufactured by Toray Dow Corning Co., Ltd.

Other additives that can be mixed in the A layer and the B layer include (meth)acrylic acid alkyl esters having 1 to 20 carbon atoms in the ester group, acrylic resins, and olefin resins. Among them, a silane coupling agent having a fluorinated substituent is preferable.

5. Physical properties of the laminated film of the present invention

<State peeling force>

It is preferable that the normal peeling force of the laminated film of the present invention is 100 mN/cm or less.

When using a laminated film as a release film, the lower the normal peeling force, the less force required to peel off the adhesive layer. For this reason, problems such as peeling failure and deformation of the adhesive layer in the production process of peeling the release film from the laminate on which the adhesive layer is laminated and attaching the adhesive layer to various members can be suppressed. . Among them, even if the laminated film of the present invention is an adhesive layer having strong adhesive properties such as a silicone adhesive, the above problems are suppressed and the laminated film can have low peelability. In addition, as a release film, in a laminate provided with a release film on both sides of an adhesive layer, it is possible to prevent the phenomenon of the release film being peeled off on an unintended side.

From this point of view, the normal peeling force is preferably 70 mN/cm or less, more preferably 40 mN/cm or less, particularly preferably 35 mN/cm or less, and most preferably 30 mN/cm or less. On the other hand, the lower limit is not particularly limited, but from the viewpoint of storage stability of the laminate in which the laminated film and the adhesive layer are laminated, 1 mN/cm or more is preferable, and 3 mN/cm or more is more preferable.

Methods for lowering the normal peeling force include adjusting the fluorine atom content ratio of the A layer or B layer. In addition, the normal peeling force is measured by the method described in the Examples described later.

6. Laminated construction

The laminated film of the present invention may have a structure in which a layer A is provided on one side or both sides of the polymer film, and a layer B is provided on the layer A. Additionally, if necessary, another layer may be interposed between the polymer film and the A layer or between the A layer and the B layer.

Other layers include an antistatic layer with antistatic properties and an oligomer sealing layer that seals exudation (bleed, plate out) of the compound or oligomer onto the film surface.

In addition, the layers such as the antistatic layer and the oligomer encapsulation layer can be formed by either an in-line coating method that is formed at the same time as the polymer film is formed, or an offline coating method that is formed in a separate process on the polymer film that has been formed. It may be possible.

The thickness of the entire laminated film in the present invention is preferably 5 μm or more and 1250 μm or less, more preferably 10 μm or more and 500 μm or less, and still more preferably 10 to 200 μm or less.

7. Method for producing the laminated film of the present invention

<Manufacturing method>

(1) Polymer film

As the polymer film that serves as the base of the laminated film of the present invention, a film formed of polyethylene, polypropylene, polyester, polystyrene, polycarbonate, and other polymer materials into a film shape is used, as described above.

Hereinafter, a method for producing a polyester film will be described using an example.

As a method for producing the polyester film used in the present invention, a method of using polyester raw materials such as the above-mentioned polyethylene terephthalate and cooling and solidifying the molten sheet extruded from the die with a cooling roll to obtain an unstretched sheet is preferable. At this time, in order to improve the flatness of the sheet, it is desirable to increase the adhesion between the sheet and the rotary cooling drum by electrostatic application adhesion method and/or liquid application adhesion method.

Although the obtained unstretched sheet can be used as is, it is preferable to stretch it at least uniaxially, and more preferably, stretch it biaxially. When the polyester film is stretched uniaxially or more, good mechanical strength and dimensional stability are obtained. Additionally, when used as a release film, when laminating adherends (adhesion layers) to produce an adhesive sheet having a laminated film, the occurrence of problems during bonding can be suppressed.

Stretching conditions are also not particularly limited. For example, an unstretched sheet is stretched 2 to 6 times in the longitudinal direction (machine direction) at 70 to 145°C by a roll stretching method to obtain a uniaxially stretched polyester film, and then A biaxially stretched film is obtained by stretching 2 to 6 times at 80 to 160°C in a direction perpendicular to the previous stretching direction (width direction) using a tenter, and then heat treating the film at 150 to 250°C for 1 to 600 seconds. .

At this time, in the heat treatment zone and/or the cooling zone at the heat treatment outlet, a method of relaxing 0.1 to 20% in the longitudinal direction and/or the width direction is more preferable.

(2) Formation of A layer (undercoating layer) and B layer (release layer)

The method of forming the A layer and the B layer is not limited, and may be formed by a coextrusion method or the like, but a coating method is preferable.

The number of applications of the A layer and the B layer may be one or two or more times. When forming the A layer and the B layer by applying two or more times, different coating liquids may be applied. However, it is necessary that at least any coating liquid contains a fluorine atom.

The application method may be in-line coating or offline coating, and for example, an application technique as shown in “Coating Method” (written by Yuji Harazaki, Maki Shoten, published in 1979) can be used.

For example, coating heads include air duct coaters, blade coaters, rod coaters, knife coaters, squeeze coaters, impregnation coaters, reverse roll coaters, transfer roll coaters, gravure coaters, kiss roll coaters, cast coaters, spray coaters, curtain coaters, Examples include a calendar coater and an extrusion coater.

The solid mass concentration of the coating liquid forming the A layer and the B layer is preferably 0.01 mass% or more, more preferably 0.05 mass% or more, and still more preferably 0.1 mass% or more. On the other hand, as an upper limit, 90 mass% or less is preferable, 50 mass% or less is more preferable, and 20 mass% or less is especially preferable.

The solvent for dilution may be a polar solvent or a non-polar solvent. Additionally, a fluorine solvent having a fluorine atom may be used. Additionally, two or more types of the above solvents may be mixed and used. In particular, it is preferable that the coating liquid forming the B layer contains a fluorine solvent having a fluorine atom for the purpose of increasing wettability to the A layer.

Polar solvents include alcohols such as ethanol and (iso)propyl alcohol; esters such as methyl acetate, ethyl acetate, (iso)propyl acetate, (iso)butyl acetate, (iso)pentyl acetate, ethyl lactate, and ethyl benzoate; Ketones such as methyl ethyl ketone, methyl isobutyl ketone, cyclopentanone, cyclohexanone, diacetone alcohol, diisobutyl ketone, ethylene glycol, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, propylene glycol monomethyl ether acetate , glycols such as propylene glycol monomethyl ether, N-methyl-2-pyrrolidone, N,N-dimethylformamide, tetrahydrofuran, and acetonitrile.

Nonpolar solvents include aromatic hydrocarbons such as benzene, toluene, and xylene, aliphatic hydrocarbons such as hexane, heptane, and octane, hydrocarbons with branched structures such as isohexane, isooctane, and isononane, cyclohexane, and cycloheptane. , alicyclic hydrocarbons such as cyclooctane, and dioxane. Examples of fluorine solvents include hydrofluoroethers, metaxylenehexafluoride, and tridecafluorooctane.

An example of a method for forming such a layer is to prepare in advance a coating liquid that has a fluorine atom content ratio corresponding to each layer after application and drying, and then use this.

In addition, a curable non-fluorinated silicone resin is used, and a predetermined amount of fluorinated material is mixed with the curable liquid to prepare a coating liquid with a composition corresponding to the A layer/B layer, and then applied and dried to form A containing the desired fluorine atom. layer and/or B layer. This method is preferable because it can more simply produce a release film having an A layer/B layer with a predetermined fluorine atom content ratio.

In addition, these A layers and B layers can be formed by applying and drying the A layer and then applying and drying the B layer. However, in the present invention, the B layer is applied following the application of the A layer, and then dried. It is possible to form it by the wet coating method, which can be expected to shorten the production process and improve energy efficiency.

As another method, the A layer is formed by applying a mixture of a curable fluorinated silicone resin and a curable non-fluorinated silicone resin, and then the B layer is formed by applying a solution containing a curable fluorinated silicone resin as a main component, This method is more preferable because it can stably produce a release film.

As another method, a non-fluorinated resin may be formed in advance by coating, and then a fluorinated layer may be created through a dry process such as carbon tetrafluoride (CF ₄ ) plasma treatment. However, this method requires the provision of a chamber for plasma processing, so it can be said to be suitable for large-scale production.

As a method for producing a laminated film of the present invention, when using so-called in-line coating, which is coating within the process of manufacturing a polymer film, both the A layer and the B layer may be in-line coated, or only the A layer may be in-line coated, Layer B may be coated offline.

When preparing both the A layer and the B layer by offline coating, they may be formed continuously in one “base film unwinding-winding process” or may be formed sequentially through multiple “base film unwinding-winding processes.” , the former is a particularly preferable method because the manufacturing process is simple and can be manufactured at a lower cost.

In addition, by lowering the amount of heat applied to the film when forming the A layer than the amount of heat applied when forming the B layer, deterioration of the film planarity during the formation of the B layer can be suppressed, and the occurrence of uneven application of the B layer can also be effectively prevented. This is desirable because it can be prevented.

8. How to use laminated film

Since the laminated film of the present invention has excellent release properties, it can be provided, for example, as an adhesive sheet having a laminated film having a structure in which the laminated film and the adhesive layer are laminated. In particular, since the laminated film of the present invention has excellent release properties even for silicone adhesives having strong adhesiveness, for example, an adhesive having a laminated film having a structure in which the above-described laminated film and an adhesive layer made of a silicone adhesive are laminated. It can be provided as a sheet.

However, the method of using the laminated film is not limited to these methods. For example, since the laminated film contains fluorine atoms, it is excellent in water resistance, water repellency, oil resistance, oil repellency, anti-fog property, anti-fouling property, chemical resistance, corrosion resistance, etc., so it is used for printed boards, optical member protective films, and building materials films. , agricultural films, high water-repellent films, packaging films, cosmetic films, surface protection films, etc. In the case of applications in which the B layer surface is used as the outermost surface, an adhesive layer, an adhesive layer, a heat seal layer, etc. may be formed on the side of the polymer film opposite to the side having the A layer and the B layer.

<Silicone adhesive>

Examples of the silicone adhesive include addition reaction type, peroxide curing type, or condensation reaction type silicone adhesive. Among them, an addition reaction type silicone adhesive is preferably used from the viewpoint of being able to be cured at a low temperature and in a short time. In addition, this addition reaction type silicone adhesive is cured upon forming the 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, if necessary, a silicone resin solution diluted with a solvent such as toluene, added with a catalyst such as a platinum catalyst, stirred to become uniform, and then applied on a support to obtain a solution of 100%. It can be cured at ~130℃/1~5 minutes.

Additionally, 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 primer treatment before forming the adhesive layer.

Commercially available silicone resins used in the addition reaction type silicone adhesive include SD4580PSA, SD4584PSA, SD4585PSA, SD4587LPSA, SD4560PSA, SD4570PSA, SD4600FCPSA, SD4593PSA, DC7651ADHESIVE, DC7652ADHESIVE, LTC-755, and LTC-310 (all Toray ·Made by Dow Corning), KR-3700, KR-3701, X-40-3237-1, X-40-3240, X-40-3291-1, X-40-3229, 40-3270-1 (all manufactured by Shin-Etsu Chemical Co., Ltd.), AS-PSA001, AS-PSA002, AS-PSA003, AS-PSA004, AS-PSA005, AS-PSA012, AS-PSA014, PSA-7465 (all manufactured by Arakawa Chemical Industry Co., Ltd. ), TSR1512, TSR1516, TSR1521 (all manufactured by Momentive Performance Materials), etc.

Example

Hereinafter, the present invention will be described in more detail using examples, but the present invention is not limited to the following examples. In addition, in the examples below, all raw materials described as “additional type” mean “curable.”

(1) Evaluation method

(1-1) State peeling force

In an environment of 23°C, a tape with a silicone adhesive (No5413 tape, 50 mm wide, manufactured by 3M Japan) was bonded to the surface of the B layer (release layer) of the laminated film, and set in a peel tester. The normal peeling force was measured under the conditions of a peeling speed of 0.3 m/min and a peeling angle of 180°.

(1-2) Fluorine atom content ratio, fluorine atom content ratio

The fluorine atom content ratio in the A layer and the B layer was evaluated using TOF-SIMS (TRIF V, manufactured by Ulbak-Pi Corporation).

Au ³⁺ was used as the primary ion, and ^the acceleration voltage was 30 kV.

To evaluate the fluorine atom content per unit volume, etching with Ar gas (voltage: 5 kV, current: 2 nA, etching speed: 20 nm/min (PET film equivalent)) was performed for 0 min, 1 min, 2 min, and 3 min, respectively. The average of the ratio of the number of counts of anions (“F ^- ” and “CH ₃ SiO ₂ ^- ”) detected at the etching time is calculated as the fluorine atom content ratio per unit volume (“F ^- ”/“CH ₃ SiO ₂ ^- 」).

In addition, the value of [Fluorine atom content ratio of B layer]/[Fluorine atom content ratio of A layer] was taken as the ratio of fluorine atom content ratio. This value has the same meaning as the result of measuring the fluorine atom content ratio (atomic number fraction) of each of the A and B layers using XPS and calculating the ratio of the values for each layer.

[Example 1]

(Coating solution 1)

The following composition was mixed and diluted using a mixed solvent of isopropyl ether and ethyl acetate (mass ratio = 1:1) so that the solid content concentration was 4% by mass, to prepare “Coating Liquid 1.”

<Composition of coating solution 1>

Addition-type organosilicon (KS-847, manufactured by Shin-Etsu Chemical Co., Ltd.): 67 parts by mass

Platinum catalyst (manufactured by Shin-Etsu Chemical Co., Ltd., CAT-PL-50T): 0.7 parts by mass

Addition-type fluorinated silicon (Toray-Dow Corning, Syl-off 3062): 100 parts by mass

Cross-linking agent (manufactured by Toray/Dow Corning, Syl-off 3062A): 0.5 parts by mass

Platinum catalyst (Toray/Dow Corning, FSXK-3077): 0.5 parts by mass

(Coating liquid 2)

The following compositions were mixed and diluted so that the solid content concentration was 0.5% by mass using a mixed solvent of FS thinner (manufactured by Shin-Etsu Chemical Co., Ltd.)/ethyl acetate = 1:1 (mass ratio) to prepare “Coating Liquid 2.”

<Composition of coating solution 2>

Addition type fluorinated silicone (manufactured by Shin-Etsu Chemical, X-70-201S): 100 parts by mass

Platinum catalyst (manufactured by Shin-Etsu Chemical Co., Ltd., CAT-PL-50T): 0.5 parts by mass

(Creation of laminated film)

Using a PET film (“T100-38” manufactured by Mitsubishi Chemical Corporation, thickness 38 μm) as a polymer film, the above-mentioned coating solution 1 was applied on the polymer film using a bar coater (No4 bar) and incubated in an oven at 150°C for 30 seconds. By drying, the resin of the A layer was cured, and a polymer film having an A layer (undercoat layer) was created.

On top of the A layer of the polymer film having the A layer (undercoating layer), the above coating liquid 2 is further applied using a bar coater (No4 bar) and dried in an oven at 150° C. for 30 seconds to cure the resin of the B layer. By doing so, a laminated film was produced in which layer B (release layer) was provided on layer A (undercoat layer).

[Example 2]

A laminated film was produced in the same manner as in Example 1, except that the solid content concentration of the coating liquid 2 was 4% by mass.

Additionally, since Coating Liquid 2 is applied using the same bar coater as Example 1, the thickness of layer B increases compared to Example 1 by increasing the solid content concentration.

[Comparative Example 1]

In the same manner as in Example 1, except that the A layer (undercoating layer) was not formed on the polymer film and only the above coating solution 2 was applied using a bar coater (No4 bar), the polymer film and the B layer (release layer) were substantially formed. ) A laminated film consisting of only was produced.

[Comparative Example 2]

A laminated film was produced in the same manner as in Comparative Example 1, except that the solid content concentration of the coating liquid 2 was set to 4% by mass.

In addition, since Coating Liquid 2 is applied using the same bar coater as Comparative Example 1, the thickness of layer B increases compared to Comparative Example 1 by increasing the solid content concentration.

[Comparative Example 3]

On top of the A layer (undercoat layer), the application liquid 2 was not applied and the B layer (release layer) was not formed in the same manner as in Example 1, and substantially only the polymer film and the A layer (undercoat layer) were used. A laminated film was produced.

[Comparative Example 4]

(Coating solution 3)

Coating liquid 3 was prepared with the following composition.

<Composition of coating solution 3>

Addition-type organosilicon (manufactured by Shin-Etsu Chemical Co., Ltd., KS-847H): 67 parts by mass

Platinum catalyst (manufactured by Shin-Etsu Chemical Co., Ltd., CAT-PL-50T): 0.7 parts by mass

The composition was diluted with a mixed solvent of n-hexane and MEK (mass ratio = 1:1) so that the solid content concentration was 4% by mass.

(Creation of laminated film)

On top of the polymer film, the coating liquid 3 was applied using a bar coater (No4 bar) and dried in an oven at 150°C for 30 seconds to prepare A layer (undercoat layer).

Next, the coating liquid 2 was attempted to be applied onto the A layer (undercoat layer) using a bar coater (No4 bar). However, since the coating liquid 2 was not uniformly applied on the A layer (undercoating layer) and a dot-shaped or linear (mesh-shaped) phenomenon (cissing) occurred, the B layer (release layer) could not be formed.

[Comparative Example 5]

For the B layer (release layer), a laminated film was attempted to be produced in the same manner as in Comparative Example 4, except that the solid content concentration of the coating liquid 2 was set to 4% by mass. However, since “Coating Liquid 2” was not uniformly applied on the A layer (undercoating layer) and a dot-shaped or linear (mesh-shaped) phenomenon (seeding) occurred, the B layer (release layer) was used. could not be formed.

[Example 3]

(Coating solution 4)

The following composition was mixed and diluted using a mixed solvent of isopropyl ether and ethyl acetate (mass ratio = 1:1) so that the solid content concentration was 4% by mass, to prepare “Coating Liquid 4.”

<Composition of coating solution 4>

Addition-type organosilicon (manufactured by Shin-Etsu Chemical, KS-847): 133 parts by mass

Platinum catalyst (manufactured by Shin-Etsu Chemical Co., Ltd., CAT-PL-50T): 1.3 parts by mass

Addition-type fluorinated silicon (Toray-Dow Corning, Syl-off 3062): 100 parts by mass

Cross-linking agent (manufactured by Toray/Dow Corning, Syl-off 3062A): 0.5 parts by mass

Platinum catalyst (Toray/Dow Corning, FSXK-3077): 0.5 parts by mass

(Creation of laminated film)

On top of the polymer film, the above-mentioned coating solution 4 was applied instead of the above-mentioned coating solution 1, except that the above-mentioned coating solution 2 diluted to a solid content concentration of 2% by mass was applied on the cured A layer (undercoat layer). In the same manner as in Example 1, a laminated film was produced.

[Example 4]

(Coating solution 5)

The following composition was mixed and diluted using a mixed solvent of isopropyl ether and ethyl acetate (mass ratio = 1:1) so that the solid content concentration was 4% by mass, to prepare “Coating Liquid 5.”

<Composition of coating solution 5>

Addition-type organosilicon (manufactured by Shin-Etsu Chemical, KS-847): 200 parts by mass

Platinum catalyst (manufactured by Shin-Etsu Chemical Co., Ltd., CAT-PL-50T): 2.0 parts by mass

Addition-type fluorinated silicon (Toray-Dow Corning, Syl-off 3062): 100 parts by mass

Cross-linking agent (manufactured by Toray/Dow Corning, Syl-off 3062A): 0.5 parts by mass

Platinum catalyst (Toray/Dow Corning, FSXK-3077): 0.5 parts by mass

(Creation of laminated film)

A laminated film was produced in the same manner as in Example 3, except that the coating solution 5 was applied on the polymer film instead of the coating solution 4 to form an A layer (undercoat layer).

[Example 5]

(Coating solution 6)

The following composition was mixed and diluted using a mixed solvent of isopropyl ether and ethyl acetate (mass ratio = 1:1) so that the solid content concentration was 4% by mass, to prepare “Coating Liquid 6.”

<Composition of coating solution 6>

Addition-type organosilicon (manufactured by Shin-Etsu Chemical, KS-847): 267 parts by mass

Platinum catalyst (manufactured by Shin-Etsu Chemical Co., Ltd., CAT-PL-50T): 2.0 parts by mass

Addition-type fluorinated silicon (Toray-Dow Corning, Syl-off 3062): 100 parts by mass

Cross-linking agent (manufactured by Toray/Dow Corning, Syl-off 3062A): 0.5 parts by mass

Platinum catalyst (Toray/Dow Corning, FSXK-3077): 0.5 parts by mass

(Creation of laminated film)

A laminated film was produced in the same manner as in Example 3, except that the coating solution 6 was applied on the polymer film instead of the coating solution 4 to form an A layer (undercoat layer).

(3) Evaluation of results

For the obtained laminated film, the fluorine atom content ratio of the A layer (undercoat layer) and B layer (release layer) and the normal peeling force using a silicone adhesive tape were measured. The results are shown in Table 1 below.

In Examples 1 and 2, the A layer (undercoating layer) and B layer (release layer) specified in the present invention were formed on the PET film, so in Comparative Examples 1 and 2 using a film of only the B layer (release layer) In comparison, it was found that good peelability was obtained.

In particular, the laminated film of Example 1 had a thinner B layer (release layer) than Example 1, despite the fact that the thickness of the B layer (release layer) was thin (the concentration of coating liquid 2 was "0.5% by mass"). ), the same level of peelability as the thick release film of Example 2 (concentration of coating liquid 2 was "4% by mass") was obtained. From this point of view, it was found that it was possible to produce a release film with excellent peelability for silicone adhesives using a smaller amount of fluorine-based material.

In addition, the release films of Examples 3 to 5, in which the fluorine atom content of the A layer (undercoat layer) is smaller than that of Example 1, also achieved the same level of peelability as the release film of Example 1, and the silicone adhesive It was found that it was possible to produce a release film with excellent peelability using a smaller amount of fluorine-based material.

In addition, in order to evaluate the fluorine atom content ratio of each layer, the fluorine atom content ratio was measured by TOF-SIMS for the samples of Comparative Example 3 (A layer only) and Comparative Example 2 (B layer only), respectively, for A layer and It was said to be the value of the B floor. As a result, it was confirmed that the B layer had a higher fluorine atom content per unit volume compared to the A layer.

In addition, since the composition of the coating liquid was the same, this value was used as the value of the fluorine atom content ratio of each layer in Examples 1 and 2 and Comparative Example 1. In addition, the fluorine atom content ratio of the A layer in Examples 3 to 5 was calculated and obtained from the raw material composition ratio based on the value of the fluorine atom content ratio in Example 1.

In addition, the fluorine atom content of the A layer is highest on the surface (etching time of 0 minutes in TOF-SIMS), and decreases as the etching time becomes longer (i.e., towards the base PET film side), and the fluorine atom content on the surface side decreases. It is thought that it has an inclined structure in which the fluorine atom content increases. The values shown in Table 1 are average values in the thickness direction.

1 polymer film
2 A layer (undercoating layer)
3 B layer (different layer)
4 Silicone adhesive layer

Claims (12)

A laminated film in which an A layer and a B layer are laminated in this order on at least one side of a polymer film,
A laminated film characterized in that both layers of the A layer and the B layer contain fluorine atoms, and the fluorine atom content of the B layer is greater than the fluorine atom content of the A layer. According to claim 1,
A laminated film wherein the content of fluorine atoms in the B layer is 1.1 times or more than the content of fluorine atoms in the A layer. A laminated film in which an A layer and a B layer are laminated in this order on at least one side of a polymer film,
A laminated film, wherein the B layer contains a fluorine atom and has a normal peeling force of 100 mN/cm or less as measured by the method below.
<Measurement of state peeling force>
A tape with a silicone adhesive (No5413 tape, 50 mm wide, manufactured by 3M Japan) was bonded to the surface of layer B of the laminated film, and a 180° peel test was performed under the condition of a peel speed of 0.3 m/min. According to claim 1 or 3,
A laminated film wherein the polymer film is a biaxially oriented polyester film. According to claim 1 or 3,
A laminated film containing a fluorinated silicone resin in the A layer and the B layer. According to claim 1 or 3,
The layer A is a laminated film containing a non-fluorinated silicone resin and a fluorinated silicone resin. According to claim 1 or 3,
A laminated film wherein the A layer and the B layer are layers formed by curing a curable fluorinated silicone resin. According to claim 5,
The ratio of the fluorine ion (F ^- ) content and the methylsiloxane ion (CH ₃ SiO ₂ ^- ) content as measured using a time-of-flight secondary ion mass spectrometer (TOF-SIMS) ([F ^- ]/[ CH ₃ SiO ₂ ^- ]) is 1 to 1,000 in the A layer and 3 to 5,000 in the B layer. According to claim 1 or 3,
A laminated film in which the fluorine atom content ratio (atomic number fraction) of the A layer is 50 ppm or more and less than 900,000 ppm, and the fluorine atom content ratio (atomic number fraction) of the B layer is 3,000 ppm or more and 900,000 ppm or less. A release film using the laminated film according to claim 1 or 3. A laminate obtained by laminating the release film according to claim 10 and an adhesive layer. According to claim 11,
A laminate in which an adhesive layer is provided on the side of the B layer that is not in contact with the A layer.