Release Film and Method for Producing the Same

Abstract

To provide a release film showing small peel force, which can be used stably in a manufacturing process.SOLUTION: A release film has a release layer on at least one face of a substrate film, wherein a modulus of elasticity (E) of the release film measured from the release layer face side by using an atomic force microscope is 0.1 MPa or over and under 1.5 MPa.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a release film and a method for manufacturing the same.

Background Art

[0002] In order to protect the surface that comes into contact with the adherend of the adhesive sheet, a release film having a release layer provided on the surface of a base film is used.

[0003] Examples of release films are disclosed in Patent Documents 1 to 3.

[0004] The release film disclosed in Patent Document 1 is a release film including an antistatic layer containing a binder and an antistatic agent, and it is disclosed that the release layer is a silicone release layer.

[0005] Further, the release film disclosed in Patent Document 2 is a release film including a crosslinked resin layer formed from a crosslinked thermoplastic resin. When the melting point of the uncrosslinked thermoplastic resin is Tm (°C), the ratio of the storage elastic modulus of the release film at Tm + 20 (°C) to the storage elastic modulus of the release film at Tm (°C) is 50% or more. A release film is disclosed.

[0006] Further, Patent Document 3 discloses a release sheet including a base material and a release agent layer provided on at least one surface side of the base material. The base material is composed of a plastic film, and the release agent layer is formed from a release agent composition containing a polyorganosiloxane having a weight average molecular weight of 5000 or more and 100000 or less. The thickness of the release agent layer is 0.3 μm or more and 1.0 μm or less. Using an atomic force microscope, the elastic modulus of the release sheet measured from the surface side opposite to the base material in the release agent layer is 1.5 MPa or more and 5.0 MPa or less. A release sheet is disclosed.

Prior Art Documents

Patent Documents

[0007]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0008] However, in recent years, the thinning of liquid crystal TVs, smartphones, tablets, etc. has further advanced, and it has become necessary to thin various electronic components that make up these liquid crystal TVs, smartphones, and tablets. The thinning of the polarizing plate, which is one of the above-mentioned electronic components, has also been progressing rapidly. In the manufacture of liquid crystal TVs and the like using a polarizing plate, there is a step of laminating a protective film, a polarizing plate, an adhesive, and the release surface of a release film on the adhesive surface of the adhesive, and then peeling the release layer of the release film from the adhesive surface. Until now, when the polarizing plate was thick, the peeling between the adhesive surface and the release layer was performed well. However, when trying to reduce the thickness of the polarizing plate, since there is no resistance in the polarizing plate, when peeling the release film from the adhesive surface, there is a problem that the protective film and the polarizing plate are also peeled off.

[0009] Conventional release films disclosed in Patent Documents 1 to 3 do not exhibit a small enough peeling force to cope with the above situation, and are not release films that can be stably used in the above process.

[0010] An object of the present invention is to provide a release film that exhibits a small peeling force and can be stably used in the manufacturing process in order to solve the above problems.

Means for Solving the Problems

[0011] In order to solve the above problems, the present invention has the following configuration. That is, (1) A release film having a release layer on at least one surface of a base film, wherein the elastic modulus (E) of the release film measured from the side of the release layer surface using an atomic force microscope is 0.1 MPa or more and less than 1.5 MPa. (2) The release film according to (1) above, wherein the release layer is composed of a plurality of layers, and the total thickness (A) of the release layer is 0.05 μm or more and 2.0 μm or less. (3) The release film according to (2) above, wherein the ratio (B / A) of the thickness (B) of the surface layer on the side opposite to the base material among the plurality of layers to the total thickness (A) of the release layer is 0.01 or more and 0.9 or less. (4) The release film according to (2) or (3) above, wherein the carbon atom concentration of the surface layer on the side opposite to the base material among the plurality of layers is higher than the carbon atom concentration of the layer on the base material side among the plurality of layers, the oxygen atom concentration of the surface layer on the side opposite to the base material is lower than the oxygen atom concentration of the layer on the base material side, and the silicon atom concentration of the surface layer on the side opposite to the base material is higher than the silicon atom concentration of the layer on the base material side. (5) The release film according to any one of (2) to (4) above, wherein the carbon atom concentration of the surface layer on the side opposite to the base material among the plurality of layers is 40 atm% or more and 60 atm% or less, the oxygen atom concentration is 15 atm% or more and 30 atm% or less, and the silicon atom concentration is 20 atm% or more and 40 atm% or less. (6) The release film according to any one of (2) to (5) above, wherein the carbon atom concentration of the layer on the base material side among the plurality of layers is 30 atm% or more and 60 atm% or less, the oxygen atom concentration is 25 atm% or more and 40 atm% or less, and the silicon atom concentration is 15 atm% or more and 35 atm% or less. (7) The release film according to any one of (1) to (6) above, wherein an adhesive tape is adhered to the release layer, and after leaving it at 23 °C for 24 hours, the peeling force between the release film and the adhesive tape when the tape is peeled at a peeling speed of 300 mm / min and a peeling angle of 180° is 5 mN / 50 mm or more and 80 mN / 50 mm or less. (8) The release film according to any one of (1) to (7) above, wherein the surface roughness (Sa) of the release layer is 5 nm or more and 50 nm or less. (9) The release film according to any one of (1) to (8) above, wherein the ratio (E / Sa) of the elastic modulus (E) to the surface roughness (Sa) of the release layer is 0.002 MPa / nm or more and less than 0.3 MPa / nm. (10) A method for manufacturing a release film having a release layer on at least one surface of a base film, the method including a step of applying a release agent to the base film and a step of curing the applied release agent, wherein at least one of the release agents has absorptions of at least νC-H, νSi-H, δSi-CH3, and νSi-O-Si in the spectrum measured by IR measurement, and the following formula (1) is detected by pyrolysis gas chromatography mass spectrometry, and pyrolysis products of the following general formula (2) and the following general formula (3) are detected. 1 A method for manufacturing a release film, wherein the molar ratios of the substituents Si-CH3, Si-H, Si-CH=CH2, Si-Ph, and Si-OCH3 calculated from the 1H NMR spectrum are 93.0 or more and 99.0 or less, 0.3 or more and 3.0 or less, 0.1 or more and 2.0 or less, 0.1 or more and 1.5 or less, and 0.05 or more and 1.0 or less, respectively.

[0012]

Chemical formula

[0013]

Chemical formula

[0014] (n represents an integer from 1 to 20)

[0015]

Chemical formula

[0016] (m represents an integer from 1 to 10)

Advantages of the Invention

[0017] The release film of the present invention exhibits a small release force that can be stably used in the manufacturing process.

Brief Description of the Drawings

[0018]

Figure 1

Embodiments for Carrying Out the Invention

[0019] The release film of the present invention is a release film having a release layer on at least one surface of a base film, and the elastic modulus (E) of the release film measured from the release layer side using an atomic force microscope is 0.1 MPa or more and less than 1.5 MPa.

[0020] The base film in the present invention is composed of a plastic film. Examples of such plastic films include polyesters such as polyethylene terephthalate and polyethylene naphthalate, polyolefins such as polypropylene and polymethylpentene, polycarbonate, and polyvinyl acetate. These plastic films may be single-layer or multi-layer of two or more layers of the same or different types. Among these, polyester films are preferred, and polyethylene terephthalate films are particularly preferred. Polyethylene terephthalate films are less likely to generate dust during processing, use, etc., and can effectively prevent, for example, coating defects due to dust.

[0021] Also, if desired, surface treatment such as oxidation method or roughening method, or primer treatment can be performed on the surface or both surfaces of the base film where the release layer is laminated. By performing such treatment, the adhesion between the base film and the release layer is likely to be improved. Examples of the oxidation method include corona discharge treatment, plasma discharge treatment, chromium oxidation treatment (wet), flame treatment, hot air treatment, ozone treatment, ultraviolet irradiation treatment, etc. Examples of the roughening method include sandblasting method, thermal spraying treatment method, etc. These surface treatment methods are appropriately selected according to the type of the base film. From the viewpoints of effect and operability, the corona discharge treatment method is preferred.

[0022] The thickness of the base film is preferably 10 μm or more, particularly preferably 15 μm or more, and even more preferably 20 μm or more. Also, the thickness is preferably 300 μm or less, particularly preferably 200 μm or less, and even more preferably 125 μm or less. By setting the thickness of the base film to 10 μm or more, wrinkles are less likely to occur when heat is applied during conveyance or in subsequent processes, so workability is likely to improve. Also, by setting the thickness of the base film to 300 μm or less, the firmness of the film does not become too strong, and workability is likely to improve.

[0023] In the release film of the present invention, the elastic modulus (E) of the release film measured from the release layer side using an atomic force microscope is 0.1 MPa or more and less than 1.5 MPa. The elastic modulus (E) of the release film is preferably 1.0 MPa or more and 1.4 MPa or less. When the elastic modulus (E) of the release film is less than 0.1 MPa, blocking occurs and workability deteriorates, and when it is 1.5 MPa or more, the peeling force becomes heavy and workability deteriorates. In the present invention, the elastic modulus (E) of the release film is measured by the method described later. In the present invention, as a method of setting the elastic modulus (E) of the release film within the above range, for example, a method of adjusting the crosslink density of the resin forming the release layer, a method of containing a low molecular weight resin in the release layer coating liquid, a method of adjusting the total thickness (A) of the release layer, etc. can be mentioned.

[0024] The release film of the present invention has a release layer on at least one surface of a base film. Examples of materials for forming the release layer include copolymer resin-based release agents such as alkyd resin-based release agents, polyolefin-based release agents, long-chain alkyl group-containing resin-based release agents, fluorine-based release agents, silicone-based release agents, and acrylic-silicone-based graft copolymers. Among these, silicone-based release agents are preferred because they exhibit excellent releasability and heat resistance. Silicone-based release agents can be classified into heat-curing types such as addition reaction types and condensation reaction types, ultraviolet curing types, electron beam curing types, and combined heat and ultraviolet curing types according to the reaction form, and any silicone-based release agent can be used.

[0025] The acrylic-silicone-based graft copolymer used in the present invention is a copolymer of an organopolysiloxane compound having an acrylic group and / or a methacrylic group (hereinafter also referred to as a (meth)acrylic group) and a radical polymerizable monomer having one radical polymerizable group in one molecule.

[0026] The weight average molecular weight of the acrylic-silicone-based graft copolymer is not particularly limited, but it is 100 to 100,000 in terms of polystyrene conversion based on the measurement results of gel permeation chromatography (hereinafter abbreviated as "GPC") using toluene as the developing solvent, preferably 1,000 to 50,000, and more preferably 2,000 to 30,000. If the weight average molecular weight is less than 100, the residual adhesion rate decreases, and if it exceeds 100,000, the dispersibility in the organopolysiloxane composition decreases.

[0027] In the present invention, the release layer preferably consists of a plurality of layers. The release layer consisting of a plurality of layers may be a release layer formed by applying different types of release agents two or more times, or a release layer formed by applying one type of release agent once and separated into a plurality of layers.

[0028] The release film of the present invention may have a primer layer between the release layer and the base film. By selecting the type of the primer layer, it is possible to prevent the release layer from peeling off from the base film, improve the adhesion between the release layer and the base film, and prevent deposits such as oligomers from the base film from depositing on the surface of the release layer.

[0029] Examples of the primer layer include polyester resins, urethane resins, acrylic resins, oxazoline group-containing resins, carbodiimide group-containing resins, epoxy group-containing resins, isocyanate-containing resins, copolymers thereof, and coating agents mainly composed of natural rubber or synthetic rubber. These resins may be contained singly or in combination of two different types. When forming a release layer on the base film, the primer layer may be applied once or multiple times.

[0030] In the release film of the present invention, a schematic cross-sectional view of an example when the release layer is composed of a plurality of layers is shown in FIG. 1. In the release film 5 of FIG. 1, a release layer 4 is provided on one surface of the base film 3, and the release layer 4 includes a layer 2 on the base material side and a surface layer 1 on the side opposite to the base material.

[0031] In the release film of the present invention, the total thickness (A) of the release layer is preferably 0.05 μm or more and 2.0 μm or less. In the present invention, the total thickness (A) of the release layer means the thickness of a single release layer when the release layer consists of only one layer. When the release layer is composed of a plurality of layers, it means the total thickness of all the layers included in the release layer. The total thickness (A) of the release layer is more preferably 0.1 μm or more and 1.0 μm or less. When the total thickness (A) of the release layer is 0.05 μm or more, the peeling force is likely to be reduced and the workability is improved. When it is 2.0 μm or less, the release layer is less likely to crack during peeling.

[0032] When the release layer of the release film of the present invention is composed of a plurality of layers, the ratio (B / A) of the thickness (B) of the surface layer on the side opposite to the base material among the plurality of layers to the total thickness (A) of the release layer is preferably 0.01 or more and 0.9 or less, and more preferably 0.02 or more and 0.8 or less. When the B / A is 0.01 or more or 0.9 or less, the elastic modulus (E) of the release film is likely to fall within the above range. In the present invention, the surface layer on the side opposite to the base material refers to the outermost layer among the layers in the release layer that is farthest from the base film when the release layer is composed of a plurality of layers. In the present invention, as a method for setting the B / A within the above range, for example, adjusting the content of the low-molecular components in the release layer coating liquid can be mentioned.

[0033] In the release film of the present invention, the carbon atom concentration of the surface layer on the side opposite to the base material among the plurality of layers is higher than the carbon atom concentration of the layer on the base material side among the plurality of layers, the oxygen atom concentration of the surface layer on the side opposite to the base material is lower than the oxygen atom concentration of the layer on the base material side, and the silicon atom concentration of the surface layer on the side opposite to the base material is preferably higher than the silicon atom carbon concentration of the layer on the base material side. By setting the carbon atom concentration, oxygen atom concentration, and silicon atom concentration of the surface layer on the side opposite to the base material and the layer on the base material side in the above relationship, it becomes easier to adjust the elastic modulus (E) of the release film within the above range. As a result, it becomes easier to set the peeling force between the release film and the adhesive tape described later within the target range. In the present invention, the layer on the base material side refers to the layers other than the outermost layer among the plurality of layers that is farthest from the base film when the release layer is composed of a plurality of layers. That is, the layer on the base material side refers to the layers other than the surface layer on the side opposite to the base material among the plurality of layers when the release layer is composed of a plurality of layers. In the present invention, as a method for setting each atomic concentration in the above relationship, for example, adjusting the content ratio of the low-molecular weight components and high-molecular weight components in the release layer coating liquid can be mentioned.

[0034] In the release film of the present invention, it is preferable that the carbon atom concentration of the surface layer on the side opposite to the base material among the plurality of layers is 40 atm% or more and 60 atm% or less, the oxygen atom concentration is 15 atm% or more and 30 atm% or less, and the silicon atom concentration is 20 atm% or more and 40 atm% or less. By setting the carbon atom concentration, oxygen atom concentration, and silicon atom concentration of the surface layer on the side opposite to the base material within the above ranges, it becomes easier to adjust the elastic modulus (E) of the release film within the above ranges. As a result, it becomes easier to set the peel strength between the release film and the adhesive tape, which will be described later, within the target range. In the present invention, as a method for setting each atom concentration within the above ranges, for example, adjusting the content ratio of the low molecular weight component and the high molecular weight component in the release layer coating liquid can be mentioned.

[0035] In the release film of the present invention, it is preferable that the carbon atom concentration of the layer on the base material side among the plurality of layers is 30 atm% or more and 60 atm% or less, the oxygen atom concentration is 25 atm% or more and 40 atm% or less, and the silicon atom concentration is 15 atm% or more and 35 atm% or less. By setting the carbon atom concentration, oxygen atom concentration, and silicon atom concentration of the layer on the base material side within the above ranges, it becomes easier to adjust the elastic modulus (E) of the release film within the above ranges. As a result, it becomes easier to set the peel strength between the release film and the adhesive tape, which will be described later, within the target range. In the present invention, the carbon atom concentration, oxygen atom concentration, and silicon atom concentration are measured by the method described later. In the present invention, as a method for setting each atom concentration within the above ranges, for example, adjusting the content ratio of the low molecular weight component and the high molecular weight component in the release layer coating liquid can be mentioned.

[0036] In the present invention, it is preferable that an adhesive tape is laminated on the release layer, and after leaving it at 23°C for 24 hours, when the tape is peeled at a peeling speed of 300 mm / min and a peeling angle of 180°, the peeling force between the release film and the adhesive tape is 5 mN / 50 mm or more and 80 mN / 50 mm or less. More preferably, the peeling force is 5 mN / 50 mm or more and 60 mN / 50 mm or less. When the peeling force is less than 5 mN / 50 mm, the release film is likely to peel off during conveyance. Also, when the peeling force exceeds 80 mN / 50 mm, the workability tends to deteriorate. In the present invention, the peeling force is measured by the method described below.

[0037] In the present invention, it is preferable that the surface roughness (Sa) of the release layer is 5 nm or more and 50 nm or less. More preferably, it is 10 nm or more and 40 nm or less. By setting it to 5 nm or more, charging is less likely to occur during conveyance and when the product is in a rolled state, so the workability is likely to be improved. Also, by setting it to 50 nm or less, it is less likely to leave indentations on the adhesive, so appearance defects are less likely to occur. In the present invention, the surface roughness of the release layer is measured by the method described below. In the present invention, as a method for setting the surface roughness (Sa) of the release layer within the above range, for example, adjusting the particle size and the addition amount added for the slipperiness and antiblocking of the base film can be mentioned.

[0038] In the present invention, it is preferable that the ratio (E / Sa) of the elastic modulus (E) to the surface roughness (Sa) of the release layer is 0.002 MPa / nm or more and less than 0.3 MPa / nm. More preferably, the E / Sa is 0.005 MPa / nm or more and 0.2 MPa / nm or less. When the E / Sa is 0.002 MPa / nm or more, the occurrence of blocking is likely to be suppressed, and when it is less than 0.3 MPa / nm, the occurrence of indentations in the rolled state is likely to be suppressed. In the present invention, as a method for setting the E / Sa within the above range, for example, adjusting the crosslink density of the resin forming the release layer and the content of the low molecular resin, and adjusting the particle size and the addition amount added for the slipperiness and antiblocking of the base film can be mentioned.

[0039] The method for producing a release film of the present invention is a method for producing a release film having a release layer on at least one surface of a base film, including a step of applying a release agent to the base film and a step of curing the applied release agent. At least one of the release agents has absorptions of at least νC-H, νSi-H, δSi-CH3, and νSi-O-Si in the spectrum measured by IR measurement, and the following formula (1) is detected by pyrolysis gas chromatography-mass spectrometry, and pyrolyzates of the following general formula (2) and the following general formula (3) are detected. 1 The molar ratios of the substituents Si-CH3, Si-H, Si-CH=CH2, Si-Ph, and Si-OCH3 calculated from the 1H NMR spectrum are respectively 93.0 or more and 99.0 or less, 0.3 or more and 3.0 or less, 0.1 or more and 2.0 or less, 0.1 or more and 1.5 or less, and 0.05 or more and 1.0 or less. In the present invention, as a method for making the measurement results of IR measurement, pyrolysis gas chromatography-mass spectrometry (hereinafter sometimes referred to as pyrolysis GC / MS measurement), and 1 1H NMR spectrum as described above, for example, adjusting the main skeleton of the resin forming the release layer or adjusting the content of the low molecular resin can be mentioned.

[0040]

Chemical formula

[0041]

Chemical formula

[0042] (n represents an integer from 1 to 20)

[0043]

Chemical formula

[0044] (m represents an integer from 1 to 10) The method for producing a release film of the present invention includes a step of applying a release agent to a base film and a step of curing the applied release agent.

[0045] In the method for producing a release film of the present invention, as the step of applying a release agent to a base film, a general coating method can be used. For example, coating methods such as gravure coating, gravure reverse coating, lip coating, die coating, microgravure coating, Mayer bar coating, and multi-stage reverse coating can be used.

[0046] In the method for producing a release film of the present invention, the step of curing the applied release agent is not particularly limited, but heat treatment is preferably performed at 60 to 200°C for 3 to 40 seconds, preferably at 80 to 180°C for 3 to 40 seconds. Further, if necessary, heat treatment and irradiation with active energy rays such as ultraviolet irradiation may be used in combination.

[0047] In the method for producing a release film of the present invention, at least one of the release agents has absorptions of at least νC-H, νSi-H, δSi-CH3, and νSi-O-Si in the spectrum measured by IR measurement. The absorption of νC-H in the spectrum measured by IR measurement means the absorption around 2963 cm -1 in the vicinity, the absorption of νSi-H means the absorption around 2168 cm -1 in the vicinity, the absorption of δSi-CH3 means the absorption around 1411 cm -1 in the vicinity, and the absorption of νSi-O-Si means the absorption around 1096 cm -1 in the vicinity. In the present invention, IR measurement refers to infrared spectroscopy and is measured by the method described below.

[0048] In the method for producing a release film of the present invention, pyrolysis GC / MS measurement is measured by the method described below.

[0049] In the method for producing a release film of the present invention, 1The molar ratios of the substituents Si-CH3, Si-H, Si-CH=CH2, Si-Ph, and Si-OCH3 calculated from the 1H NMR spectrum are preferably 93.0 or more and 99.0 or less, 0.3 or more and 3.0 or less, 0.1 or more and 2.0 or less, 0.1 or more and 1.5 or less, and 0.05 or more and 1.0 or less, respectively. 1 The peak of the substituent Si-CH3 calculated from the 1H NMR spectrum is around -0.2 to 0.4 ppm, the peak of Si-H is around 4.6 to 4.9 ppm, the peak of Si-CH=CH2 is around 5.6 to 6.2 ppm, the peak of Si-Ph is around 7.2 to 7.7 ppm, and the peak of Si-OCH3 is around 3.4 to 3.5 ppm. In the present invention, 1 The 1H NMR spectrum is measured by the method described below.

[0050] For at least one mold release agent forming the mold release layer, the absorption of the spectrum measured by IR measurement, the detected substances in pyrolysis GC / MS measurement, 1 By forming the mold release layer using a mold release agent in which the molar ratio of the substituent calculated from the 1H NMR spectrum is in the above state and range, using an atomic force microscope, which is the object of the present invention, the elastic modulus (E) of the mold release film measured from the mold release layer side can be made to be in the range of the object of the present invention, and a mold release film can be manufactured.

Examples

[0051] Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to the following examples.

[0052] The measurement methods used in the present invention are as follows. [Measurement Methods] (1) Measurement of the elastic modulus (E) of the mold release film by an atomic force microscope The surface on the base film side of the release films produced in the examples and comparative examples was bonded to a stainless-steel sample stage using double-sided adhesive tape. Subsequently, using a probe microscope (manufactured by Shimadzu Corporation, product name "SPM-9700") equipped with a silicone probe (manufactured by Team nanotec, product name "LRCH", radius of curvature: 250 nm, spring constant: 0.2 N / m), tapping was performed on the surface on the release layer side of the release film at a speed of 600 nm / s to obtain a force curve. From the shape of the obtained force curve, the elastic modulus (E) (MPa) of the release film was calculated by the JKR two-point method.

[0053] (2) Total thickness (A) of the release layer and thickness (B) of the surface layer on the side opposite to the base material After embedding the release film in resin, a small piece for a transmission electron microscope was taken out in the cross-sectional direction by the FIB method, and using a transmission electron microscope (TEM, manufacturer: JEOL Ltd., type name: JEM-F200, acceleration voltage 200 V, magnification 200,000 times), the total thickness of the release layer and the thickness of the surface layer on the side opposite to the base material of the cross-section of the small piece were measured at three locations, and the average value of the obtained values was taken as each thickness.

[0054] (3) Carbon atom concentration, oxygen atom concentration, and silicon atom concentration of the surface layer on the side opposite to the base material and the layer on the base material side In the same manner as in (2) above, the cross-section of the release film was observed, and the carbon, oxygen, and silicon atom concentrations of each layer were measured three points each for the surface layer on the side opposite to the base material and the layer on the base material side using a scanning transmission electron microscope, and the average value was taken as the atomic concentration of each atom.

[0055] (4) Peel strength between the release film and the adhesive tape A polyester adhesive tape (Nitto Denko Corporation No. 31B tape, 50 mm width) was bonded as an adhesive tape to the surface on the release layer side of the release film while pressing with a 5 kg roller, left standing at 23 °C for 24 hours, and then the peel strength when the tape was peeled off at a peel speed of 300 mm / min and a peel angle of 180° using a tensile testing machine was measured.

[0056] (5) Surface roughness (Sa) The surface on the release layer side and the surface on the non-release layer side were set to a measurement area of 1 mm square using a 50x objective lens of the non-contact surface / layer cross-sectional shape measurement system VertScan R5300GL-Lite-AC manufactured by the Rhombus System, and measured in accordance with ISO 25178-3.2 (2010).

[0057] (6) Absorption of the spectrum measured by IR measurement of the release agent The release agent was measured with an IR measuring device (iS5 manufactured by Thermo Fisher SCIENTIFIC Co., Ltd., sample scan count 64 times, background scan count 64 times, resolution 8.0), and the absorption of the obtained spectrum was as follows. When all of the following absorptions were confirmed, it was marked as 〇, and when even one was not confirmed, it was marked as ×.

[0058] Absorption of νC-H: around 2963 cm-1 Absorption of νSi-H: around 2168 cm-1 Absorption of δSi-CH3: around 1411 cm-1 Absorption of νSi-O-Si: absorption around 1096 cm-1 (7) Detected substances in the thermal decomposition GC / MS measurement of the release agent The release agent was measured and analyzed using a gas chromatograph 7890A manufactured by Agliment Technologies (conditions Column: “Ultra Alloy” (registered trademark)-5 (MS / HT), Column temperature: 40 °C (3 minutes)-320 °C (18 minutes) (Rate 20 °C / min), Injection temperature: 300 °C), a mass spectrometer JMS-Q1050GC manufactured by JEOL Ltd. (conditions Ionization Mode: EI+, Scan Range: m / z 10.0-800.0, Scan Rate: 05 seconds / scan), and a thermal decomposition comprehensive analysis system (Pyrolyzer PY-2020iD manufactured by Frontier Lab Co., Ltd., temperature 600 °C). When all of the following formulas (1), general formula (2), and general formula (3) were detected, it was marked as 〇, and when even one was not detected, it was marked as ×.

[0059]

Chemical formula

[0060]

Chem.

[0061] (n represents an integer from 1 to 20)

[0062]

Chem.

[0063] (m represents an integer from 1 to 10) (8) 1 Substituents calculated from the 1H NMR spectrum Regarding the release agent, using an NMR measuring device (ECA - 400 manufactured by JEOL RESONANCE Co., Ltd.), 1 the 1H NMR spectrum was measured, and the molar ratios of the substituents Si - CH3, Si - H, Si - CH=CH2, Si - Ph, and Si - OCH3 were calculated.

[0064] (9) Blocking evaluation The release films prepared in the examples and comparative examples were stacked 10 sheets so that the substrate side and the release layer side were in contact, and then cut into 5 cm × 5 cm. Subsequently, while applying a pressure of 1.5 kgf / cm 2 in the stacking direction, it was allowed to stand at 23°C for 24 hours. Then, the occurrence of blocking in this laminate was visually observed and evaluated according to the criteria shown below.

[0065] ○: No blocking occurred at all.

[0066] ×: Blocking occurred partially or entirely.

[0067] 〔Example 1〕 3 parts by weight of BY24-846B, which is 3-glycidoxypropyltrimethoxysilane (manufactured by Toray Dow Corning Co., Ltd., content 98% by weight), 1 part by weight of BY24-846C, which is 3-methacryloxypropyltrimethoxysilane (manufactured by Toray Dow Corning Co., Ltd., content 99% by weight), and 2 parts by weight of BY24-846E, which is bis(ethylacetoacetate)(2,4-pentanedionate)aluminum (manufactured by Toray Dow Corning Co., Ltd., content 38% by weight) were mixed with 50 parts by weight of toluene and 50 parts by weight of isopropyl alcohol (IPA) to prepare a primer coating solution.

[0068] 8 parts by weight of X62-2888, an addition reaction type curable silicone resin (manufactured by Shin-Etsu Chemical Co., Ltd.), and 0.08 parts by weight of PL-50T, a platinum-based catalyst as a curing agent (manufactured by Shin-Etsu Chemical Co., Ltd.) were mixed with 28 parts by weight of toluene and 64 parts by weight of n-heptane to prepare a release layer coating solution 1.

[0069] A primer coating solution was applied to a polyethylene terephthalate film with a thickness of 38 μm (manufactured by Toray Industries, Inc., "Lumirror" (registered trademark) XF60R) using a Meyer bar No. 3 so that the coating thickness after drying was 0.05 μm, and dried and cured at 100°C for 5 seconds. Then, the release layer coating solution 1 was continuously applied using a Meyer bar No. 10 so that the release layer thickness was 0.21 μm, and dried and cured at 160°C for 20 seconds to obtain a release film with a total release layer thickness of 0.26 μm. The elastic modulus, total release layer thickness, peel force, surface roughness, etc. were measured, and the results are shown in Table 1-1, Table 1-2, and Table 2. A release film with good transportability and workability was obtained. 〔Example 2〕 A release film was obtained in the same manner as in Example 1 except that the total thickness of the release layer was changed. The elastic modulus, total release layer thickness, peel force, surface roughness, etc. were measured, and the results are shown in Table 1-1, Table 1-2, and Table 2. A release film with good transportability and workability was obtained.

[0070] 〔Examples 3 and 4〕 Except for changing the total thickness of the release layer and using a polyethylene terephthalate film with a thickness of 38 μm (“Lumirror” (registered trademark) S28 manufactured by Toray Industries, Inc.), a release film was obtained in the same manner as in Example 1. The elastic modulus, the total thickness of the release layer, the peel force, the surface roughness, etc. were measured, and the results are shown in Table 1-1, Table 1-2, and Table 2. A release film with good transportability and workability was obtained.

[0071] [Comparative Example 1] In Example 1, instead of the release layer coating liquid 1, a release layer coating liquid 2 prepared by mixing 1 part by mass of a melamine compound (RP-50 manufactured by Mihaba Research Institute Co., Ltd., solid content 50% by mass), which is a thermosetting resin, and 9 parts by mass of a mixed liquid of toluene, anon, and methanol (4.5 / 3.6 / 0.9) was used. A release film was obtained in the same manner as in Example 1, except that a polyethylene terephthalate film with a thickness of 50 μm (“Lumirror” (registered trademark) U483 manufactured by Toray Industries, Inc.) was used.

[0072] The elastic modulus, the total thickness of the release layer, the peel force, the surface roughness, etc. were measured, and the results are shown in Table 1-1, Table 1-2, and Table 2. As a result, the elastic modulus, the peel force, and the workability were poor.

[0073] [Comparative Example 2] A release film was obtained in the same manner as in Example 1, except that the total thickness of the release layer was changed. The elastic modulus, the total thickness of the release layer, the peel force, the surface roughness, etc. were measured, and the results are shown in Table 1-1, Table 1-2, and Table 2. As a result, when the elastic modulus was high, the peel force was heavy and the result was poor.

[0074] [Comparative Example 3] A release film was obtained in the same manner as in Comparative Example 1, except that a polyethylene terephthalate film with a thickness of 38 μm (“Lumirror” (registered trademark) XF60R manufactured by Toray Industries, Inc.) was used. The elastic modulus, the total thickness of the release layer, the peel force, the surface roughness, etc. were measured, and the results are shown in Table 1-1, Table 1-2, and Table 2. As a result, when the elastic modulus was high, the peel force was heavy and the result was poor.

[0075] [Comparative Example 4] A release film was obtained in the same manner as in Example 1, except that the total thickness of the release layer was changed. The elastic modulus, the total thickness of the release layer, the peel force, the surface roughness, etc. were measured, and the results are shown in Table 1-1, Table 1-2, and Table 2. The elastic modulus was low and the peel force was also light, but the release layer cracked during peeling, resulting in poor workability.

[0076]

Table 1-1

[0077]

Table 1-2

[0078]

Table 2

[0079] As shown in Table 2, the release film according to the example had a very small peel force compared with the release film according to the comparative example. Furthermore, it was found that blocking was less likely to occur in the release film according to the example.

Industrial Applicability

[0080] Since the release film of the present invention has a small peel force that can be stably used in the process, it can be suitably used for the production of various thin-film electronic components that make up liquid crystal televisions, smartphones, and tablets that are becoming thinner.

Explanation of Signs

[0081] 1 Surface layer on the side opposite to the base material 2 Layer on the base material side 3 Base material film 4 Release layer 5 Release film

Claims

1. A release film having a release layer on at least one surface of a base film, wherein the elastic modulus (E) of the release film measured from the release layer side using an atomic force microscope is 0.1 MPa or more and less than 1.5 MPa, The release layer is composed of a plurality of layers, and the total thickness (A) of the release layer is 0.05 μm or more and 2.0 μm or less.

2. The release film according to claim 1, wherein the ratio (B / A) of the thickness (B) of the surface layer on the side opposite to the base material among the plurality of layers to the total thickness (A) of the release layer is 0.01 or more and 0.9 or less.

3. The carbon atom concentration of the surface layer on the side opposite to the base material among the plurality of layers is higher than the carbon atom concentration of the layer on the base material side among the plurality of layers, the oxygen atom concentration of the surface layer on the side opposite to the base material is lower than the oxygen atom concentration of the layer on the base material side, and the silicon atom concentration of the surface layer on the side opposite to the base material is higher than the silicon atom carbon concentration of the layer on the base material side. The release film according to claim 1 or 2.

4. The release film according to any one of claims 1 to 3, wherein the carbon atom concentration of the surface layer on the side opposite to the base material among the plurality of layers is 40 atm% or more and 60 atm% or less, the oxygen atom concentration is 15 atm% or more and 30 atm% or less, and the silicon atom concentration is 20 atm% or more and 40 atm% or less.

5. The release film according to any one of claims 1 to 4, wherein the carbon atom concentration of the layer on the base material side among the plurality of layers is 30 atm% or more and 60 atm% or less, the oxygen atom concentration is 25 atm% or more and 40 atm% or less, and the silicon atom concentration is 15 atm% or more and 35 atm% or less.

6. A release film having a release layer on at least one surface of a base film, wherein the elastic modulus (E) of the release film measured from the release layer side using an atomic force microscope is 0.1 MPa or more and less than 1.5 MPa, The release film, wherein an adhesive tape is bonded to the release layer, and after leaving it at 23°C for 24 hours, the peeling force between the release film and the adhesive tape when the tape is peeled at a peeling speed of 300 mm / min and a peeling angle of 180° is 5 mN / 50 mm or more and 80 mN / 50 mm or less.

7. A release film having a release layer on at least one surface of a base film, wherein the elastic modulus (E) of the release film measured from the release layer side using an atomic force microscope is 0.1 MPa or more and less than 1.5 MPa, A release film in which the surface roughness (Sa) of the release layer is 5 nm or more and 50 nm or less. **Claim 8**: A release film having a release layer on at least one surface of a base film, wherein the elastic modulus (E) of the release film measured from the release layer side using an atomic force microscope is 0.1 MPa or more and less than 1.5 MPa, and the ratio (E / Sa) of the elastic modulus (E) to the surface roughness (Sa) of the release layer is 0.002 MPa / nm or more and less than 0.3 MPa / nm. **Claim 9** A method for manufacturing a release film having a release layer on at least one surface of a base film, the method including a step of applying a release agent to the base film and a step of curing the applied release agent, wherein at least one of the release agents has, in a spectrum measured by IR measurement, at least νC-H, νSi-H, δSi-CH ３ and absorptions of νSi-O-Si are present, and in thermogravimetric gas chromatography-mass spectrometry, the following formula (1) is detected and pyrolysis products of the following general formula (2) and the following general formula (3) are detected, １ Substituent Si-CH calculated from the H NMR spectrum ３ , Si-H, Si-CH=CH ２ , Si-Ph, Si-OCH ３ The molar ratios of are 93.0 or more and 99.0 or less, 0.3 or more and 3.0 or less, 0.1 or more and 2.0 or less, 0.1 or more and 1.5 or less, and 0.05 or more and 1.0 or less, respectively. A method for manufacturing a release film. 【Chemical Formula 1】 [Chemical 2] (n represents an integer from 1 to 20) [Chemical Formula 3] (m represents an integer from 1 to 10)

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