WO2022186427A1 - Release film - Google Patents

Abstract

A release film, an optical film comprising same, and an electronic device are disclosed. The release film comprises a substrate and a release layer positioned on at least one surface of the substrate, wherein the release layer is a cured layer of a release-layer-forming composition comprising a blend of a fluorine-containing organopolysiloxane and a fluorine-free organopolysiloxane, the content ratio of fluorine atom/silicon atom decreases from the surface of the release layer to the center thereof, the reduced modulus of the release layer, measured by means of nanoindentation is 2-6 GPa, and the surface hardness of the release layer, measured by means of nanoindentation, can be 0.3-0.6 GPa.

Description

release film

It relates to a release film.

Recently, in industries such as displays, tapes, and labels, the use of carbide release films with low peeling force is increasing in order to improve processability and improve productivity.

Silicone-based release films used for general adhesives such as acrylic and epoxy are soft and thick due to low curing density, Young's modulus, reduced modulus, and hardness of the release layer. The more the peeling force is lowered. However, in the silicone-based release film, the lower the peeling force, the lower the residual adhesion rate and the adhesion to the substrate, as well as the low elastic modulus and hardness of the surface of the release layer, so blocking may occur during winding.

In addition, when the silicone-based release film uses a silicone-based adhesive, the silicone-based release film is completely laminated to the silicone-based adhesive and is not peeled off. For this reason, the silicone-based pressure-sensitive adhesive A film coated with a release agent including a fluorine-based resin is commonly used.

However, the release agent containing the fluorine-based resin has a low surface energy, so it is difficult to mix with a general organic solvent and may cause a coating defect, so a fluorine-based solvent should be used. Since the release agent containing the fluorine-based resin is several tens of times more expensive than the general silicone-based release agent, there is a problem in terms of productivity and economic efficiency.

Therefore, there is a need for a release film that can be used with both an acrylic pressure-sensitive adhesive and a silicone-based pressure-sensitive adhesive and has a high surface hardness and reduced modulus of the release layer, but a low peel force and a low rate of change in peel force.

One aspect is to provide a release film that can be used with both an acrylic pressure-sensitive adhesive and a silicone-based pressure-sensitive adhesive, and has a high surface hardness and a reduced modulus of a release layer, but has a low peel force and a low rate of change in peel force.

According to one aspect,

write; and a release layer located on at least one surface of the substrate;

The release layer is a cured layer of a composition for forming a release layer comprising a blend of a fluorinated organopolysiloxane and a fluorinated organopolysiloxane,

The release layer decreases the fluorine atom/silicon atom content ratio from the surface to the center,

The release layer has a reduced modulus measured by the nanoindentation method of 2 to 6 GPa,

The release layer has a surface hardness measured by the nanoindentation method of 0.3 to 0.6 GPa, the release film is provided.

The content (atomic%) ratio of fluorine atoms/silicon atoms by XPS analysis with respect to the surface of the release layer may be 1.5 to 4.5.

The surface energy of the release layer may be 10 dyne/cm to 16 dyne/cm.

The release film may have a peeling force of 0.5 gf/25mm to 10 gf/25mm at a peeling angle of 180° and a peeling rate of 0.3mpm for the acrylic pressure-sensitive adhesive and the silicone-based pressure-sensitive adhesive.

The release film may have a peel force change rate of 50% or less according to the following formula 2 for the acrylic pressure-sensitive adhesive and the silicone-based pressure-sensitive adhesive:

[Equation 2]

The residual adhesion rate of the release film may be 85% or more.

The release layer may have a thickness of 0.03 μm to 2.0 μm.

The fluorinated polysiloxane may include an organo polysiloxane represented by the following Chemical Formula 1:

[Formula 1]

[Formula 2]

[Formula 3]

In Formula 1,

R ₁ is a substituted or unsubstituted C1-C10 monovalent hydrocarbon group, or a substituted or unsubstituted C2-C10 alkenyl group;

R ₂ is a substituted or unsubstituted C1-C10 monovalent hydrocarbon group, a substituted or unsubstituted C2-C10 alkenyl group, or hydrogen;

R ₃ and R ₄ are each independently a fluorinated alkyl group represented by Formula 2, a fluorinated ether group represented by Formula 3, A substituted or unsubstituted C1~ C10 monovalent hydrocarbon group, a substituted or unsubstituted C2~ C10 alkenyl group, or hydrogen,

at least one of R ₃ and R ₄ is a fluorinated alkyl group represented by Formula 2, a fluorinated ether group represented by Formula 3, or a combination thereof;

n is an integer from 1 to 8, m is an integer from 1 to 5;

p is an integer from 1 to 5, q is 0 or 1, r is 0, 1 or 2, and v is an integer from 1 to 5;

A is an oxygen atom or a single bond;

x, y, and z are each an integer of 1 or more;

* is a binding site with a neighboring atom;

However, at least one of R ₁ and R ₂ may be a substituted or unsubstituted C2~C10 alkenyl group.

The content of the fluorinated organopolysiloxane may be 10 parts by weight to 300 parts by weight based on 100 parts by weight of the non-fluorinated organopolysiloxane.

The release layer may further include organic/inorganic particles.

The release layer may further include at least one of hydrogen polysiloxane and a catalyst.

A release film according to one aspect includes a release layer, which is a cured layer of a composition for forming a release layer including a blend of fluorinated organopolysiloxane and non-fluorinated organopolysiloxane. The release film has a low peel force and a low change rate of peel force for both the acrylic pressure-sensitive adhesive and the silicone-based pressure-sensitive adhesive, and has a high surface hardness and reduced modulus to prevent blocking during film winding.

1 is a schematic cross-sectional view of a release film according to an embodiment.

Hereinafter, the release film will be described in detail with reference to examples and drawings of the present invention. It will be apparent to those of ordinary skill in the art that these examples are only presented as examples to explain the present invention in more detail, and that the scope of the present invention is not limited by these examples. .

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. In case of conflict, the present specification, including definitions, will control.

Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention, suitable methods and materials are described herein.

In the present specification, the term "included" means that other components may be further included, rather than excluding other components, unless otherwise stated.

As used herein, the term “combination of these” means a mixture or combination with one or more of the described components.

As used herein, the term “and/or” is meant to include any and all combinations of one or more of the related listed items. As used herein, the term “or” means “and/or”. The expression “at least one” or “one or more” in front of components in the present specification does not imply that it may supplement the entire list of components and may supplement individual components of the description.

In the present specification, when it is stated that an element is disposed "on" or "above" another element, one element may be disposed directly on the other element, or the elements interposed between the elements are may exist. On the other hand, when an element is referred to as being disposed "directly on" or "directly on" another element, intervening elements may not be present.

As used herein, "~-based resin", "~-based polymer", or/and "~-based copolymer" means "~ resin", "~ polymer", "~ copolymer", or/and "~ resin, polymer, Or a derivative of a copolymer" is a broad concept including all.

As used herein, the term "polymer or copolymer crosslinked with these resins" means "polymer or copolymer crosslinked with the above-mentioned resins".

In the present specification, each component is a concept including both the singular and the plural.

Unless otherwise stated herein, all percentages, parts, ratios, etc. are by weight. Also, when an amount, concentration, or other value or parameter is given as any one of a range, a preferred range, or a list of upper and preferred upper limits and lower preferred limits, this means any upper range limit or preferred value and any lower limit, whether or not the range is separately disclosed. It is to be understood that all ranges formed from any pair of range limits or preferred values are specifically disclosed.

When a range of numerical values is recited herein, unless otherwise stated, the range is intended to include the endpoints and all integers and fractions within the range. It is intended that the scope of the invention not be limited to the particular values recited when defining the ranges.

A release film according to an embodiment includes a substrate; and a release layer located on at least one surface of the substrate, wherein the release layer is a cured layer of a composition for forming a release layer comprising a blend of a fluorinated organopolysiloxane and a fluorinated organopolysiloxane, and the release layer The fluorine atom/silicon atom content ratio decreases from the surface of the silver to the center direction, and the release layer has a reduced modulus measured by a nanoindentation method of 2 to 6 GPa, and the release layer has a nanoindentation method. The surface hardness measured by the tation method may be 0.3 to 0.6 GPa.

The release film according to an embodiment has low peel force and peel force change rate for both the acrylic pressure-sensitive adhesive and the silicone-based pressure-sensitive adhesive, and has high surface hardness and reduced modulus to prevent blocking during film winding.

The base material constituting the release film, the release layer, the release film, and the optical film and electronic device including the same will be described in detail as follows.

<Reference>

As the substrate used in the present invention, a known substrate film or sheet may be used as a substrate for a release film. For example, a polyester-based resin film may be used as the substrate. As the polyester-based resin, a known base film commonly used in the field of release film may be used. For example, the polyester-based base film may be a polyester-based base film disclosed in Korean Patent Registration No. 10-1268584, Korean Patent Publication No. 2012-45213, and No. 2012-99546. However, in one embodiment of the present invention, in order to describe only the features of the present invention, the polyester-based base film is described without limitation, but it should be understood as including the technical features of the known polyester-based base film. .

The polyester-based base film may include polyethylene terephthalate, polybutylene terephthalate, or polyethylene naphthalate.

The polyester-based resin forming the base film may be a polyester obtained by polycondensation of an aromatic dicarboxylic acid and an aliphatic glycol.

Examples of the aromatic dicarboxylic acid include isophthalic acid, phthalic acid, terephthalic acid, 2,6-naphthalenedicarboxylic acid, adipic acid, sebacic acid, and oxycarboxylic acid (eg, ρ-oxybenzoic acid, etc.). and examples of the aliphatic glycol include ethylene glycol, diethylene glycol, propylene glycol, butanediol, 1,4-cyclohexanedimethanol, neopentyl glycol, and the like. These polyester-based resins may use two or more of a dicarboxylic acid component and a glycol component in combination, and a copolymer containing a third component is also possible.

In addition, the polyester-based base film may use a uniaxial or biaxially oriented film having high transparency and excellent productivity and processability. As the polyester-based base film, polyethylene terephthalate (PET) or polyethylene-2,6-naphthalene dicarboxylate (PEN) may be used.

In addition, the polyester-based base film may contain particles in order to provide excellent running characteristics between rolls, and as long as the added particles can exhibit excellent sliding properties, they can be used without limitation.

Examples of such particles may include particles such as silica, silicon oxide, calcium carbonate, calcium sulfate, calcium phosphate, magnesium carbonate, magnesium phosphate, barium carbonate, kaolin, aluminum oxide, titanium oxide, and the like, and the shape of the particles used Although not limited to, for example, any of spherical, bulky, rod-shaped, plate-shaped particles may be used.

In addition, the hardness, specific gravity, and color of the particles are not limited, but two or more types may be used in parallel as needed, and the average particle diameter of the particles used may be 0.1 to 5 μm, for example, 0.1 to 2 μm in the range of can be used. At this time, if the average particle diameter of the particles is less than 0.1 μm, aggregation between particles may occur, resulting in poor dispersion. can occur.

In addition, when particles are included in the polyester-based base film, the content of the particles may be 0.01 to 5 wt%, for example, 0.01 to 3 wt%, based on the total weight of the polyester-based base film. If the content of the particles is less than 0.01% by weight, the sliding properties of the polyester film may deteriorate and the running characteristics between the rolls may deteriorate, and if the content of the particles exceeds 5% by weight, the surface smoothness of the film may deteriorate.

The thickness of the polyester-based base film is not limited, but may be 20 to 125 μm.

If the polyester-based base film is too thin at 20 um or less, there is a risk of deformation by heat treatment during processing, and if it is too thick over 125 um, heat may not be sufficiently transmitted and there may be a problem in curing.

<Release layer>

The release layer of the release film according to an exemplary embodiment may be a cured layer of a composition for forming a release layer including a blend of fluorinated organopolysiloxane and fluorinated organopolysiloxane.

In the release layer, the fluorine atom/silicon atom content ratio may decrease from the surface to the center. The release layer has a higher content of fluorine atoms compared to silicon atoms on its surface, so the peelability is excellent when laminated with a silicone pressure-sensitive adhesive. can have

The content (atomic%) ratio of fluorine atoms/silicon atoms by X-ray photoelectron spectroscopy (XPS) analysis on the surface of the release layer may be 1.5 to 4.5. If the content (atomic%) ratio of fluorine atoms/silicon atoms by XPS analysis with respect to the surface of the release layer is less than 1.5, it may not be peeled off during lamination with the silicone-based pressure-sensitive adhesive. If the content (atomic%) ratio of fluorine atoms/silicon atoms by XPS analysis with respect to the surface of the release layer exceeds 4.5, a large amount of heat is required to cure the fluorinated organopolysiloxane, so it may cause thermal deformation of the substrate and hardness Since it is high, the peeling force to the acrylic pressure-sensitive adhesive may increase.

In addition, when the surface of the release layer is etched by plasma treatment and the inside of the release layer is analyzed with an XPS analyzer, the depth of the release layer contains less than 80 atomic% of fluorine atoms based on 100 atomic% of silicon atoms. . In the present specification, "deep part" means the inside of the release layer etched by plasma on the surface of the release layer, and more specifically, when analyzed with an XPS analyzer, the atomic% of C (carbon) from the surface of the release layer is 60 atomic% Refers to a point inside the release layer. As the fluorine atoms of the release layer are positioned on the surface of the coating layer, the better the peeling force, so if the fluorine atoms in the release layer are 80 atomic% or more, the fluorine atom weight on the surface of the release layer decreases and the silicon atom content increases, so that peeling off when laminated with a silicone pressure-sensitive adhesive may not be

The fluorinated polysiloxane may include an organo polysiloxane represented by the following Chemical Formula 1:

[Formula 1]

[Formula 2]

[Formula 3]

In Formula 1,

R ₁ may be a substituted or unsubstituted C1~C10 monovalent hydrocarbon group, or a substituted or unsubstituted C2~C10 alkenyl group;

R ₂ may be a substituted or unsubstituted C1-C10 monovalent hydrocarbon group, a substituted or unsubstituted C2-C10 alkenyl group, or hydrogen;

R ₃ and R ₄ are each independently a fluorinated alkyl group represented by Formula 2, a fluorinated ether group represented by Formula 3, A substituted or unsubstituted C1~ C10 monovalent hydrocarbon group, a substituted or unsubstituted C2~ C10 alkenyl group, or hydrogen,

at least one of R ₃ and R ₄ is a fluorinated alkyl group represented by Formula 2, a fluorinated ether group represented by Formula 3, or a combination thereof;

n may be an integer from 1 to 8, m may be an integer from 1 to 5;

p may be an integer from 1 to 5, q may be 0 or 1, r may be 0, 1 or 2, v may be an integer from 1 to 5;

A may be an oxygen atom or a single bond;

x, y, z may each be an integer of 1 or more;

* may be a binding site with a neighboring atom;

However, at least one of R ₁ and R ₂ may be a substituted or unsubstituted C2~C10 alkenyl group.

The fluorine-free organo polysiloxane may be represented by the following Chemical Formula 4:

[Formula 4]

In Formula 4,

R _a may be a substituted or unsubstituted C1-C10 monovalent hydrocarbon group, or a substituted or unsubstituted C2-C10 alkenyl group;

R _b may be a substituted or unsubstituted C1-C10 monovalent hydrocarbon group, a substituted or unsubstituted C2-C10 alkenyl group, or hydrogen;

Each of x' and y' may be an integer of 1 or more.

In some cases, the fluorinated polysiloxane may be a blend of the organo polysiloxane represented by the formula (1) and the organo polysiloxane represented by the following formula (5), or the organo polysiloxane represented by the formula (1) and the organo polysiloxane represented by the formula (5) It may be a copolymer in which the organo polysiloxane is linked:

[Formula 5]

[Formula 6]

In Formula 5,

R′ ₁ may be a substituted or unsubstituted C1-C10 monovalent hydrocarbon group, or a substituted or unsubstituted C2-C10 alkenyl group;

R′ ₂ may be a fluorine-containing ether group represented by Formula 6;

n' may be an integer from 1 to 8, m' may be an integer from 3 to 17;

* may be a binding site with a neighboring atom.

For example, a weight ratio of the organopolysiloxane represented by Formula 1 to the organopolysiloxane represented by Formula 5 may be 10:1 to 1:10.

The content of the fluorinated organopolysiloxane may be 10 parts by weight to 300 parts by weight based on 100 parts by weight of the non-fluorinated organopolysiloxane. If the content of the fluorinated organopolysiloxane is less than 10 parts by weight based on 100 parts by weight of the non-fluorinated organopolysiloxane, the fluorine group on the surface of the release layer is not sufficiently cured to increase the surface energy, and the hardness is lowered due to blocking and penetration of the adhesive Significant changes over time may occur. For this reason, when the release layer and the silicone pressure-sensitive adhesive are laminated, it may not be peeled off. If the content of the fluorinated organopolysiloxane exceeds 300 parts by weight based on 100 parts by weight of the non-fluorinated organopolysiloxane, a lot of energy is required during curing of the fluorine-containing organopolysiloxane, and there is a fear that the substrate may be deformed.

The surface energy of the release layer may be 10 dyne/cm to 16 dyne/cm. If the surface energy of the release layer is less than 10 dyne/cm, the pressure-sensitive adhesive may not be applied due to the low surface energy. If the surface energy of the release layer is more than 16 dyne/cm, the fluorinated organopolysiloxane on the surface of the release layer may not be sufficiently cured, and the release layer and the silicone pressure-sensitive adhesive may not be peeled off.

The release layer may have a reduced modulus measured by a nanoindentation method of 2 to 6 GPa.

If the conversion modulus of elasticity of the release layer is less than 2 GPa, the release layer becomes soft and a blocking phenomenon may occur during winding. If the converted elastic modulus of the release layer is more than 6 GPa, the peeling force is increased by the hard release layer.

The release layer may have a surface hardness measured by a nanoindentation method of 0.3 to 0.6 GPa.

If the surface hardness of the release layer measured by the nanoindentation method is less than 0.3 GPa, the surface hardening degree is lowered, and thus, a large change over time may occur due to penetration of the pressure-sensitive adhesive. When the surface hardness of the release layer measured by the nanoindentation method is greater than 0.6 GPa, the peeling force may increase due to the high surface hardness.

The release layer may further include organic/inorganic particles.

The organic and inorganic particles are natural minerals; oxides, hydroxides, sulfides, nitrides, or halides of elements of Groups 1 to 4, 11 to 12, 14 and 16 to 18; carbonate, sulfate, acetate, phosphate, phosphite, carboxylate, silicate, titanate, borate, or hydrates thereof; and inorganic particles selected from these complex compounds.

The organic/inorganic particles may be organic particles selected from fluorine-based resins, melamine-based resins, styrene-based resins, acrylic resins, silicone-based resins, styrene-divinylbenzene-based copolymer resins, and polymers or copolymers crosslinked with these resins.

The shape of the organic/inorganic particles used is not particularly limited, and may be spherical, bulky, rod-shaped, or flat-shaped. In addition, the hardness, specific gravity, color, etc. of the organic/inorganic particles are not limited, and if necessary, these organic/inorganic particles may be used alone, or two or more kinds may be used.

The average particle diameter (D50) of the organic/inorganic particles may be 1 μm to 5 μm. For example, the average particle diameter (D50) of the organic-inorganic particles may be 3 μm to 5 μm or 1 μm to 2 μm. In the present specification, the term "average particle diameter (D50)" refers to 50% from the smallest particle when the total number of particles is 100% in the distribution curve accumulated in the order of the smallest particle to the largest particle. It means the value of the particle size. The D50 value can be measured by a method well known to those skilled in the art, for example, it can be measured with a particle size analyzer, or can be measured from a TEM photograph or an SEM photograph. As another method, it is measured using a measuring device using a dynamic light-scattering method, data analysis is performed, the number of particles is counted for each particle size range, and the D50 value is calculated therefrom. can be obtained easily.

If the average particle diameter (D50) of the organic-inorganic particles is less than 1 μm, the blocking phenomenon cannot be prevented because sufficient surface roughness cannot be obtained. If the average particle diameter (D50) of the organic-inorganic particles exceeds 5 μm, it may act as a defect of the film.

The release layer may further include at least one of hydrogen polysiloxane and a catalyst.

The hydrogen polysiloxane may include at least one of an addition reaction type siloxane resin, a condensation reaction type siloxane resin, and an ultraviolet curing type siloxane resin. The hydrogen polysiloxane may be in one of linear, branched, or cyclic form, and may be in the form of a mixture thereof. The hydrogen polysiloxane is not limited in viscosity or molecular weight, but compatibility with the aforementioned organo polysiloxane should be good, and the hydrogen polysiloxane may not contain a fluorine group. However, the hydrogen polysiloxane may include the same fluorine-containing alkyl group and/or fluorine-containing ether group as the aforementioned organo polysiloxane.

The content of the hydrogen polysiloxane may be 1.0 to 10.0 wt% based on the total weight of the composition for forming a release layer.

The catalyst may use one or more metals or amphoteric elements selected from Groups 4 to 14 elements, for example, one or more selected from Rh, Pt, Sn, Ti, Pd, Ir, W, and Co. can For example, the catalyst may comprise a platinum chelate catalyst.

In some cases, the release layer may further include additives for imparting various functions such as a reaction modifier and an antistatic agent.

The release layer may have a thickness of 0.03 to 2.0 μm. If the thickness of the release layer is less than 0.03 um, the release layer coverage may not be good and may not be peeled off during lamination with an acrylic pressure-sensitive adhesive or/and a silicone-based pressure-sensitive adhesive. If the thickness of the release layer exceeds 2.0 um, it may cause thermal deformation of the substrate because it requires a large amount of heat during curing, and the cost may increase because peelability is not improved.

The composition for forming a release layer for forming the release layer is prepared by containing a solvent with a solid content of 0.5 to 10% by weight. The solvent may be used without limitation as long as it can be applied on the substrate by dispersing the solid content, for example, aromatic hydrocarbon-based solvents such as toluene and xylene; aliphatic hydrocarbon solvents such as hexane, heptane, octane, isooctane, decane, cyclohexane, methyl cyclohexane and isoparaffin; Hydrocarbon solvents, such as industrial gasoline (rubber gasoline etc.), petroleum benzene, and solvent naphtha; Acetone, methyl ethyl ketone, 2-pentanone, 3-pentanone, 2-hexanone, 2-heptanone, 4-heptanone, methyl isobutyl ketone, diisobutyl ketone, acetonylacetone, cyclohexanone, etc. ketone solvents; ester solvents such as ethyl acetate, propyl acetate, isopropyl acetate, butyl acetate, and isobutyl acetate; ether solvents such as diethyl ether, dipropyl ether, diisopropyl ether, dibutyl ether, 1,2-dimethoxyethane, and 1,4-dioxane; solvents having ester and ether moieties such as 2-methoxyethyl acetate, 2-ethoxyethyl acetate, propylene glycol monomethyl ether acetate, and 2-butoxyethyl acetate; siloxane solvents such as hexamethyldisiloxane, octamethyltrisiloxane, octamethylcyclotetrasiloxane, decanemethylcyclopentasiloxane, tris(trimethylsiloxy)methylsilane, and tetrakis(trimethylsiloxy)silane; fluorine-based solvents such as trifluorotoluene, hexafluoroxylene, methyl nonafluorobutyl ether, and ethyl nonafluorobutyl ether; Or a mixed solvent thereof and the like may be used. For example, heptane may be used as a solvent used in the composition for forming the release layer.

If the solid content of the composition for forming a release layer is less than 0.5 wt %, a sufficient coating thickness may not be formed, so that the release property may not be expressed. If the solid content of the composition for forming the release layer exceeds 10% by weight, the viscosity of the composition for forming the release layer is high, so leveling unevenness may occur, and thus the thickness uniformity of the release layer may be deteriorated, and the coating thickness may be thickened and not cured it may not be

As a method of applying the composition for forming the release layer to one surface of the substrate, an offline coating method available in the art such as bar coating, gravure coating, die coating, etc. may be used. The energy source for curing the composition for forming the release layer is not particularly limited, but heat treatment, ultraviolet irradiation, or electron beam irradiation may be used, and these may be used alone or in combination, but heat treatment alone or combination treatment of heat and ultraviolet light may be used. can

<Release film>

1 is a schematic cross-sectional view of a release film 100 according to an embodiment.

Referring to FIG. 1 , a release film 120 according to an exemplary embodiment has a structure in which a substrate 100 and a release layer 110 are sequentially positioned.

The release film 120 according to an embodiment has a low peel force and a low peel force change rate for both the acrylic adhesive and the silicone adhesive, and has high surface hardness and reduced modulus to prevent blocking during film winding. have.

The release film 120 may have a peeling force of 0.5 gf/25mm to 10 gf/25mm at a peeling angle of 180° and a peeling rate of 0.3mpm for the acrylic adhesive and the silicone-based adhesive.

If the release film 120 has less than 0.5 gf/25mm at a peeling angle of 180 ° and a peeling rate of 0.3 mpm, the release film 120 has a peeling force for the acrylic pressure-sensitive adhesive and the silicone-based pressure-sensitive adhesive. The laminated interface may be lifted. If the release film 120 has more than 10 gf/25mm at a peeling angle of 180° and a peeling rate of 0.3 mpm, the peeling force for the acrylic pressure-sensitive adhesive and the silicone-based pressure-sensitive adhesive is not properly peeled from the acrylic pressure-sensitive adhesive or/and the silicone-based pressure-sensitive adhesive. Problems can arise.

The release film 120 may have a peel force change rate of 50% or less according to Equation 2 below for the acrylic pressure-sensitive adhesive and the silicone-based pressure-sensitive adhesive:

[Equation 2]

The release film 120 may implement a stable peeling force for the acrylic adhesive and the silicone adhesive without changing over time.

The residual adhesion rate of the release film 120 may be 85% or more.

If the residual adhesion rate of the release film 120 is less than 85%, the release agent may be transferred to the adhesion layer due to insufficient curing of the release layer 110, and the adhesion of the pressure-sensitive adhesive may be deteriorated.

As used herein, "substitution" is derived by exchanging one or more hydrogens with another atom or functional group in an unsubstituted mother group. Unless otherwise stated, when a functional group is considered to be “substituted,” it means that the functional group is an alkyl group having 1 to 40 carbon atoms, an alkenyl group having 2 to 40 carbon atoms, an alkynyl group having 2 to 40 carbon atoms, or a cyclo group having 3 to 40 carbon atoms. It means substituted with one or more substituents selected from an alkyl group, a cycloalkenyl group having 3 to 40 carbon atoms, and an aryl group having 7 to 40 carbon atoms. When a functional group is described as being “optionally substituted”, it is meant that the functional group may be substituted with the aforementioned substituents.

In the present specification, the C1-C10 monovalent hydrocarbon group includes, for example, a linear alkyl group such as a methyl group, an ethyl group, a hexyl group, an octyl group, and a decyl group; branched alkyl groups such as isopropyl group, tert-butyl group, neopentyl group and hexyl group; Cyclic alkyl groups, such as a cyclopentyl group and a cyclohexyl group, Aryl groups, such as a vinyl group, a henyl group, and a tolyl group, Arylalkyl groups, such as a benzyl group and a phenethyl group; means etc. Among them, it may be an alkyl group in consideration of the ease of procurement of raw materials, and may be a methyl group or an ethyl group in consideration of the usefulness of the product.

In the present specification, the C2-C10 alkenyl group refers to a branched or unbranched hydrocarbon having at least one carbon-carbon double bond. Non-limiting examples of alkenyl groups include vinyl, allyl, butenyl, isopropenyl, or isobutenyl.

Hereinafter, the configuration of the present invention and its effects will be described in more detail through Examples and Comparative Examples. However, it will be apparent that these examples are for illustrating the present invention in more detail, and the scope of the present invention is not limited to these examples.

[Example]

Example 1: Release film

A 50 μm thick polyester film (Toray Advanced Materials, XD500P) was prepared.

Separately, as the fluorinated organopolysiloxane, 100 parts by weight of an organopolysiloxane represented by the following Chemical Formula 1 including a fluorinated alkyl group represented by the following Chemical Formula 2 (Dow Chemical, Q2-7785), a fluorine-free containing a vinyl group and a methyl group 100 parts by weight of organopolysiloxane (Shin-Etsu, KS847H), 3 parts by weight of hydrogen polysiloxane (Q2-7560, Dow Chemical), and 0.1 parts by weight of a platinum chelate catalyst (manufactured by Dow Chemical, SYL-OFF 4000) are diluted in heptane solvent Thus, a composition for forming a release layer having a total solid content of 5% by weight was prepared.

A release film was prepared by coating the composition for forming a release layer on one surface of the polyester film and heat-treating it for 60 seconds in a hot air dryer at 150° C. to form a release layer with a thickness of 0.3 μm.

[Formula 1]

[Formula 2]

In Formula 1,

R ₁ is a vinyl group, R ₂ , R ₃ are each a methyl group, R ₄ is a fluoroalkyl group represented by Formula 2,

n is 4, m is 2, and * is a bonding site with a neighboring atom.

Example 2: Release film

In the same manner as in Example 1, except that 50 parts by weight of the organopolysiloxane represented by Formula 1 (Dow Chemical, Q2-7785) including the fluorinated alkyl group represented by Formula 2 was used as the fluorinated organopolysiloxane. A release film was prepared.

Example 3: Release film

As the fluorinated organopolysiloxane, 50 parts by weight of the organopolysiloxane represented by Formula 1 (Dow Chemical, Q2-7785) including a fluorinealkyl group represented by Formula 2 and a fluorine ether group represented by Formula 6 below A release film was prepared in the same manner as in Example 1, except that 50 parts by weight of the organopolysiloxane represented by 5 (Shin-Etsu Silicone, X-70-201S) was used:

[Formula 5]

[Formula 6]

In Formula 5,

R′ ₁ is a vinyl group, R′ ₂ is a fluorine ether group represented by Formula 6;

n' is 2, m' is 4, and x' is 1.

Example 4: Release film

Instead of 100 parts by weight of the fluorinated organopolysiloxane represented by Chemical Formula 4 (Shin-Etsu, KS847H), 50 parts by weight of the fluorinated organopolysiloxane represented by Chemical Formula 4 (Shin-Etsu, KS847H) and a fluorine-free organ containing a hexenyl group A release film was prepared in the same manner as in Example 1, except that 50 parts by weight of gano polysiloxane (manufactured by Dow Chemical, LTC750A) was used.

Example 5: Release film

Except that the release film was prepared by coating the composition for forming a release layer on one side of the polyester film and heat-treating it for 60 seconds in a hot air dryer at 150° C. to form a release layer with a thickness of 1 μm. A release film was prepared in the same manner.

Example 6: Release film

A release film was prepared in the same manner as in Example 1, except that a composition for forming a release layer was prepared by adding 1 wt% of silica particles having a particle diameter of 2 μm based on the total solid content.

Comparative Example 1: Release film

In the same manner as in Example 1, except that 5 parts by weight of the organopolysiloxane (Dow Chemical, Q2-7785) represented by Formula 1 including the fluorinated alkyl group represented by Formula 2 was used as the fluorinated organopolysiloxane. A release film was prepared.

Comparative Example 2: Release film

In the same manner as in Example 1, except that 500 parts by weight of the organopolysiloxane represented by Formula 1 (Q2-7785, manufactured by Dow Chemical) including a fluorinated alkyl group represented by Formula 2 was used as the fluorinated organopolysiloxane. A release film was prepared.

Comparative Example 3: Release film

Except that the release film was prepared by coating the composition for forming a release layer on one side of the polyester film and heat-treating it in a hot air dryer at 150° C. for 60 seconds to form a release layer having a thickness of 2.5 μm, and A release film was prepared in the same manner.

Comparative Example 4: Release film

Except that the release film was prepared by coating the composition for forming a release layer on one side of the polyester film and heat-treating it for 60 seconds in a hot air dryer at 150° C. to form a release layer having a thickness of 0.01 μm. A release film was prepared in the same manner.

Comparative Example 5: Release film

A release film was prepared in the same manner as in Example 1, except that fluorinated organopolysiloxane was not used.

Comparative Example 6: Release film

A release film was prepared in the same manner as in Example 1, except that the fluorinated organopolysiloxane represented by Chemical Formula 4 (Shin-Etsu, KS847H) was not used.

Evaluation Example 1: Physical property evaluation

The physical properties of the release films prepared in Examples 1 to 6 and Comparative Examples 1 to 6 were evaluated in the following manner, and the results are shown in Table 1.

(1) XPS analysis on the surface of the release layer

The atomic composition of silicon (Si), fluorine (F), carbon (C), and oxygen (O) was analyzed with an XPS analyzer for the surface of the release layer of each release film and expressed in atomic%. As the XPS analyzer, K-ALPHA from ThermoFisher was used, and the spot size was set to 400 μm. In addition, the content (atomic%) ratio of fluorine atoms/silicon atoms was calculated using the analyzed fluorine atoms and silicon atoms.

(2) Peel force of the release film (gf/25mm) and rate of change in peel force (%)

Each release film was cut into a size of 500 mm x 1500 mm to prepare a sample. The samples were stored at 25° C., 65% RH for 24 hours (initial peel force sample) and 7 days (7 days later peel force sample). After that, the silicone-based adhesive tape (SYMBIO, MY2G) and the acrylic adhesive tape (TESA, TESA7475) were respectively pressed at 50 °C and 20 g/cm ² under a load of 20 g/cm 2 for 24 hours on the release layer of the samples, and then the cheminstrument AR-1000 device was applied. The peel force of 250 mm x 1500 mm size was measured using 180 °, 0.3 mpm speed. At this time, the peel force was measured 5 times and then the average value was calculated to obtain the initial peel force and the peel force after 7 days, and the rate of change of the peel force was obtained by substituting the formula 2 below:

[Equation 2]

(3) Residual adhesion rate of release film (%)

Each release film was cut into a size of 500 mm x 1500 mm to prepare a sample. The samples were stored at 25° C., 65% RH for 24 hours. After pressing the adhesive tape (Nitto, 31B) on the release layer of the samples at room temperature and under a load of 20 g/cm ² for 24 hours, the adhesive tape adhered to the release layer was collected without contamination. The adhesive tape was adhered to the surface of the polyethylene terephthalate film having a flat and clean surface. The adhesive tape adhered to the surface of the polyethylene terephthalate film was reciprocally compressed once with a 2 kg tape roller (ASTMD-1000-55T). Then, with respect to the adhesive tape sample pressed onto the polyethylene terephthalate film surface, the peel force of the size of 250 mm x 1500 mm was measured at 180 ° and 0.3 mpm speed using a cheminstrument AR-1000 device, and substituted into Equation 3 below. Thus, a residual adhesion rate was obtained.

[Equation 3]

(4) Converted modulus of elasticity (GPa) and surface hardness (GPa) of the release layer

The reduced modulus and surface hardness were measured for the release layer of each release film using a nanoindenter analyzer (Hysitron, TI950 Triboindenter).

	Initial Peeling Force for Acrylic Adhesives (gf/ 25mm)	Peel force after 7 days for acrylic adhesive (gf/25mm)	Peel force change rate for acrylic adhesive (%)	Peeling force for silicone adhesive (gf/ 25mm)	Residual Adhesion (%)	fluoride content (atomic%)	Silicon content (atomic%)	Fluorine/ Silicon content ratio	conversion modulus of elasticity (GPa)	surface hardness (GPa)
Example 1	4.5	5.6	24.4	5.6	86	35	13	2.7	3.7	0.38
Example 2	4.6	6.2	34.7	7.1	86	34	14	2.4	3.3	0.32
Example 3	4.5	5.4	20	4.6	85	39	9	4.3	4.1	0.37
Example 4	4.5	6.1	35.5	6.8	92	34	12	2.8	3.4	0.34
Example 5	4.2	5.4	28.6	6.1	85	34	14	2.7	3.4	0.32
Example 6	4.5	5.5	22.2	7.2	87	33	15	2.2	3.5	0.37
Comparative Example 1	7.8	12.4	58.9	x	90	24	19	1.2	2.2	0.26
Comparative Example 2	6.1	13.7	124.5	8.9	80	34	17	2.0	3.8	0.34
Comparative Example 3	5.5	13.5	145.4	9.3	79	32	14	2.3	3.4	0.30
Comparative Example 4	38	73.8	94.2	29.8	91	33	12	2.7	-	-
Comparative Example 5	4.7	12.5	165.9	x	78	-	43	-	1.9	0.12
Comparative Example 6	12	13.2	10	7.8	86	30	15	2.0	4.6	0.42

Referring to Table 1, it can be seen that the release films prepared in Examples 1 to 6 have stable peeling force due to low peeling force with respect to the silicone-based adhesive, and the peeling force and peeling force change rate for the acrylic adhesive.

The release film prepared by Comparative Example 1 (when the fluorinated organopolysiloxane content is low) and Comparative Example 5 (when only the non-fluorinated organopolysiloxane is used alone) The release film was completely laminated to the silicone pressure-sensitive adhesive, so that it was not peeled off It can be seen that the conversion modulus of elasticity and the surface hardness of the release layer are low, so that the peel force change rate is as large as 50% or more. The release films prepared by Comparative Example 2 (when the content of fluorinated organopolysiloxane is high) and Comparative Example 3 (when the thickness of the release layer is thick) did not cure well, so the residual adhesion rate was reduced and the peel force change rate was also high that can be checked The release film prepared by Comparative Example 6 (when only fluorinated organopolysiloxane was used alone) showed light peeling properties with a peeling force of 10 gf/25mm or less with respect to the silicone adhesive, but the peeling force with respect to the acrylic adhesive was 10 gf/ Measured over 25mm. The release film prepared by Comparative Example 4 (when the thickness of the release layer was thin) had poor coverage of the release layer, so that the peeling force was high when laminating with the silicone pressure-sensitive adhesive and the acrylic pressure-sensitive adhesive. From this, it can be seen that since the release layer of the release film of the present invention has an appropriate converted modulus and surface hardness, the release film exhibits light peeling properties for both the acrylic pressure-sensitive adhesive and the silicone-based pressure-sensitive adhesive. In addition, it can be seen that the release film of the present invention has a high surface hardness compared to the silicone-based release film, so that the peel force change rate for the acrylic pressure-sensitive adhesive is low, and blocking is improved when the release film is wound.

Claims (11)

1. write; and a release layer located on at least one surface of the substrate;

   The release layer is a cured layer of a composition for forming a release layer comprising a blend of a fluorinated organopolysiloxane and a fluorinated organopolysiloxane,

   The release layer decreases the fluorine atom/silicon atom content ratio from the surface to the center,

   The release layer has a reduced modulus measured by the nanoindentation method of 2 to 6 GPa,

   The release layer has a surface hardness measured by the nanoindentation method of 0.3 to 0.6 GPa, the release film.
2. The method of claim 1,

   The content (atomic%) ratio of fluorine atoms / silicon atoms by XPS analysis on the surface of the release layer is 1.5 to 4.5, the release film.
3. According to claim 1,

   The surface energy of the release layer is 10 dyne / cm to 16 dyne / cm, the release film.
4. According to claim 1,

   The release film is a release film of 0.5 gf/25mm to 10 gf/25mm at a peeling angle of 180 ° and a peeling rate of 0.3 mpm, the peeling force for the acrylic pressure-sensitive adhesive and the silicone-based pressure-sensitive adhesive.
5. The method of claim 1,

   The release film is a release film having a peel force change rate of 50% or less according to the following formula 2 for an acrylic pressure-sensitive adhesive and a silicone-based pressure-sensitive adhesive:

   [Equation 2]

   
6. The method of claim 1,

   A release film having a residual adhesion rate of 85% or more of the release film.
7. According to claim 1,

   The release layer has a thickness of 0.03 μm to 2.0 μm, a release film.
8. The method of claim 1,

   A release film, wherein the fluorinated polysiloxane comprises an organo polysiloxane represented by the following formula (1):

   [Formula 1]

   

   [Formula 2]

   

   [Formula 3]

   

   In Formula 1,

   R ₁ is a substituted or unsubstituted C1-C10 monovalent hydrocarbon group, or a substituted or unsubstituted C2-C10 alkenyl group;

   R ₂ is a substituted or unsubstituted C1-C10 monovalent hydrocarbon group, a substituted or unsubstituted C2-C10 alkenyl group, or hydrogen;

   R ₃ and R ₄ are each independently a fluorinated alkyl group represented by Formula 2, a fluorinated ether group represented by Formula 3, A substituted or unsubstituted C1~ C10 monovalent hydrocarbon group, a substituted or unsubstituted C2~ C10 alkenyl group, or hydrogen,

   at least one of R ₃ and R ₄ is a fluorinated alkyl group represented by Formula 2, a fluorinated ether group represented by Formula 3, or a combination thereof;

   n is an integer from 1 to 8, m is an integer from 1 to 5;

   p is an integer from 1 to 5, q is 0 or 1, r is 0, 1 or 2, v is an integer from 1 to 5;

   A is an oxygen atom or a single bond;

   x, y, and z are each an integer of 1 or more;

   * is a binding site with a neighboring atom;

   However, at least one of R ₁ and R ₂ is a substituted or unsubstituted C2~C10 alkenyl group.
9. According to claim 1,

   The content of the fluorinated organopolysiloxane is 10 parts by weight to 300 parts by weight based on 100 parts by weight of the non-fluorinated organopolysiloxane, the release film.
10. According to claim 1,

    The release layer further comprises organic and inorganic particles, a release film.
11. According to claim 1,

    The release layer further comprises at least one of a hydrogen polysiloxane and a catalyst.

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