KR102407857B1 - Anti-static silicone release film with excellent release characteristic - Google Patents

Abstract

base layer; a release layer formed on one surface of the base layer and comprising a silicone resin; and an antistatic layer formed on the other surface of the base layer and comprising inert particles and a conductive polymer, a release film is provided.

Description

Antistatic silicone release film with excellent release properties {ANTI-STATIC SILICONE RELEASE FILM WITH EXCELLENT RELEASE CHARACTERISTIC}

The present invention relates to an antistatic silicone release film having excellent release properties. Specifically, the present invention relates to a silicone release film having light release properties, blocking resistance and antistatic properties.

The release film is coated with a release agent on one side or both sides of a substrate, and is mainly laminated on a sticky surface such as an adhesive to protect it and then easily release it. Release films, for example, are used to temporarily protect adhesive surfaces from dust, debris, moisture and other contaminants until optical adhesive products are used.

Recently, the use and varieties of optical adhesive products have been diversified and the production volume has increased, and the type has been changed to a form with various adhesive properties for reasons such as productivity improvement. Interest in the release film that can be used is increasing. Since the release film applied to the optical pressure-sensitive adhesive product is peeled off from the pressure-sensitive adhesive surface immediately before use of the product, it is required to have peelability with the pressure-sensitive adhesive surface while maintaining adhesion to the product before peeling.

A release film applied to an optical pressure-sensitive adhesive product generally includes a silicone release layer on a polyester film having good optical properties and processability. Silicone release film is a product used throughout the industry and is mainly applied as a base material for adhesive products or casting products, and in particular, it is used to protect the adhesive surface of various adhesive products used in the recently growing display field. Recently, as the size of TSP (Touch Screen Panel), OLED display, etc. increases, the area of the optical adhesive film for display increases, and the release rate of the release film is accelerated to improve productivity, and a silicone release having a lighter release force. Film is in demand.

Korean Patent No. 0646147

For the production of a release film having a light release force, it may be considered to form a thick silicone release layer, but such a thick release layer has a problem of causing a blocking phenomenon in the process of winding or laminating the film.

In order to solve this problem, a method of forming irregularities on the surface of the base film may be considered, but the quality of the release layer coated on the non-planar base film may be poor. In addition, when inorganic inert particles or non-reactive siloxane is added to the silicone release layer, a light release force can be realized without forming a thick release layer. There is a problem of impairing the quality of the adhesive surface.

Accordingly, an object of the present invention is to provide a release film capable of suppressing the generation of blocking and static electricity and maintaining the quality of the adhesive surface while securing light release peeling force.

According to one embodiment of the present invention, the base layer; a release layer formed on one surface of the base layer and comprising a silicone resin; and an antistatic layer formed on the other surface of the base layer and comprising inert particles and a conductive polymer, a release film is provided.

According to the above embodiment, by adding inert particles to the antistatic layer formed on the opposite side of the release layer to provide irregularities, blocking does not occur even when the release layer is thickly formed for light release characteristics, and the effect of static electricity during peeling can be minimized. Therefore, the release film according to the embodiment can be easily released while maintaining the quality of the adhesive surface by being applied to an optical adhesive product.

1 shows a cross-sectional view of a release film according to an embodiment.
2 is a cross-sectional view of a release film according to another embodiment.
3 is a cross-sectional view of a release film according to another embodiment.

In the description of the embodiments below, when one component is described as being formed on or below another component, one component is directly above or below another component, or another component is interposed It includes everything that is formed indirectly by

In addition, the reference for the upper / lower of each component will be described with reference to the drawings. The size of each component in the drawings may be exaggerated for explanation, and may be different from the size actually applied.

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

In addition, it should be understood that all numerical ranges indicating physical property values, dimensions, etc. of the components described in the present specification are modified by the term "about" in all cases unless otherwise specified.

In the present specification, unless otherwise specified, the expression "a" and "a" should be construed as meaning including the singular or the plural as interpreted in context.

Composition and properties of release film

Referring to FIG. 1 , the release film 10 according to an embodiment includes a base layer 100 ; a release layer 200 formed on one surface of the base layer 100 and comprising a silicone resin; and an antistatic layer 300 formed on the other surface of the base layer 100 and including inert particles 310 and a conductive polymer.

According to the above embodiment, by adding inert particles to the antistatic layer formed on the opposite side of the release layer to provide irregularities, blocking does not occur even when the release layer is thickly formed for light release characteristics, and the effect of static electricity during peeling can be minimized. Therefore, the release film according to the embodiment can be easily released while maintaining the quality of the adhesive surface by applying it to an optical adhesive product.

The release film according to the embodiment has a release peel force required to achieve a fast peel rate required in the recent display field. The release layer may have a release peel force of 4.0 gf/inch or less for the TESA 7475 tape. For example, the release peel force for the TESA 7475 tape of the release layer may be 4.0 gf / inch or less, 3.5 gf / inch or less, or 3.0 gf / inch or less, and also 0.1 gf / inch or more, 1.0 gf / inch or more, 2.0 gf/inch or greater, or 2.5 gf/inch or greater. As a specific example, the release layer may have a release peel force of 2.0 gf/inch to 4.0 gf/inch with respect to the TESA 7475 tape.

In addition, since the release film according to the above embodiment does not contain inert particles in the release layer, it is possible to prevent deterioration of the quality of the adhesive surface due to detachment or transfer of the inert particles when applied to the adhesive surface, and as a result, the release layer and The adhesive strength of the adhesive surface can be maintained even after peeling off.

Specifically, the release layer may have a residual adhesive rate of 90% or more according to the following formula:

Residual adhesion rate (%) = (Release peel force A / Release peel force B) X 100

Here, the release peel force A is the release peel force (gf/inch) measured by attaching the Nitto 31B tape to the release layer and then attaching it to a polyethylene terephthalate (PET) film, and the release peel force B is the Nitto 31B tape is the release peel force (gf/inch) measured by attaching and peeling off the Teflon film and attaching it to the PET film.

When the residual adhesive ratio is 90% or more, the adhesive strength of the adhesive surface is maintained even after peeling off the release film protecting the adhesive surface, and thus it can be applied to products such as displays. More specifically, the release layer may have a residual adhesive ratio of 95% or more according to the above formula.

In addition, the release film according to the embodiment has low adhesion between the coating surface and the back surface of the film in contact with each other when the roll is wound, so that the blocking resistance can be maintained even when the release layer is thickly formed.

In addition, the release film according to the embodiment may have a surface resistance of 10 ⁵ Ω/□ to 10 ⁹ Ω/□. Specifically, the surface of the antistatic layer of the release film may have a surface resistance of 10 ⁵ Ω/□ to 10 ⁹ Ω/□. Accordingly, the release film can maintain the quality of the adhesive surface by preventing static electricity that may occur during lamination and peeling of the adhesive surface. For example, the surface resistance may be 10 ⁵ Ω/□ or more, 10 ⁶ Ω/□ or more, or 10 ⁷ Ω/□ or more, and also 10 ⁹ Ω/□ or less, 10 ⁸ Ω/□ or less, or 10 ⁷ It can be less than Ω/□.

Hereinafter, the components of the release film will be described in detail.

base layer

The base layer acts as a base on which the release layer and the antistatic layer can be formed.

The material of the base layer is not limited as long as it is a material generally used for the base layer in the release film.

The base layer may be a polymer resin layer, for example, a polymer film having flexibility and transparency.

Specifically, the base layer may include a polyester resin, a polyvinyl chloride (PVC) resin, a polyethylene (PE) resin, a polypropylene (PP) resin, a polycarbonate (PC) resin, or a mixed resin thereof. The polyester resin may include an alkylene terephthalate unit or an alkylene naphthalate unit as a structural unit of the polymer. Specific examples of the polyester resin include polyethylene terephthalate (PET), polybutylene terephthalate (PBT), and polyethylene naphthalate (PEN).

As an example, the base layer may be a polyester film, specifically, a polyethylene terephthalate film.

The thickness of the base layer is not particularly limited, but may be, for example, 10 μm to 200 μm. When the thickness of the base layer is 10 μm or more, it is possible to reduce appearance problems that may occur during the thermal process and winding, and when it is 200 μm or less, flexibility may be increased, so that handling may be better. Specifically, the thickness of the base layer may be 10 μm or more, 25 μm or more, 50 μm or more, or 75 μm or more, and may be 200 μm or less, 150 μm or less, 125 μm or less, or 100 μm or less. As a specific example, the base layer may be a transparent polymer film having a thickness of 25 μm to 125 μm.

release layer

The release layer is formed on one surface of the base layer and includes a silicone resin.

The release layer provides a low release peeling force to the surface of the release film to allow easy separation after lamination with the adhesive surface.

The silicone resin included in the release layer may include polydimethylsiloxane having a vinyl group or a hexenyl group as a structural unit. For example, the polydimethylsiloxane may have a structure of Formula 1 below.

[Formula 1]

In Formula 1, X is a vinyl group or a hexenyl group, Me is a methyl group, n is an integer of 5 to 100, preferably an integer of 5 to 50, m+n is an integer of 2,000 to 10,000, preferably It is an integer from 3,000 to 10,000.

The polydimethylsiloxane may have a molecular weight of about 150,000 to 600,000.

In addition, the silicone resin included in the release layer may include hydrogen siloxane as a constituent unit. For example, the hydrogen siloxane may have a structure of Formula 2 below.

[Formula 2]

In Formula 2, Me is a methyl group, a is an integer of 1 or more, a+b is an integer of 2 to 100, and b ≤ a.

Examples of commercially available products of the hydrogen siloxane include X-92-122 (manufactured by Shin-Etsu Corporation), SYL-OFF 7028 (manufactured by Dow Corning Corporation), and the like. Sometimes there is.

As an example, the silicone resin included in the release layer may include polydimethylsiloxane having a vinyl group or a hexenyl group, and hydrogensiloxane as structural units.

In addition, the release layer may further include a catalyst for controlling the crosslinking density of the silicone resin. Examples of the catalyst include a platinum (Pt)-based catalyst, a ruthenium (Ru)-based catalyst, an osmium (Os)-based catalyst, an alloy-based catalyst thereof, and a mixture thereof. The release layer may include the catalyst in an amount of 0.1 to 5 parts by weight, specifically 0.5 to 2 parts by weight, based on 100 parts by weight of the polydimethylsiloxane.

Specifically, the release layer may include an addition reaction type silicone resin obtained by reacting polydimethylsiloxane having a vinyl group or a hexenyl group with hydrogensiloxane under a catalyst. During the addition reaction, the Si-H group of the hydrogensiloxane reacts with the vinyl group or the hexenyl group of the polydimethylsiloxane. More specifically, the release layer may be formed of an organic solvent-type addition reaction type silicone composition obtained by reacting polydimethylsiloxane having a vinyl group or a hexenyl group with hydrogensiloxane under a platinum-based catalyst.

The silicone resin may include 0.1 to 5 parts by weight of the hydrogen siloxane based on 100 parts by weight of the polydimethylsiloxane. When the content of the hydrogen siloxane is 0.1 parts by weight or more, migration of the silicone resin is suppressed when attached to the adhesive surface, so that the residual adhesive rate can be improved, and when the content is 5 parts by weight or less, the release force is constantly maintained even when stored for a long time. better to keep Specifically, the silicone resin may include 0.2 to 2 parts by weight of the hydrogen siloxane based on 100 parts by weight of the polydimethylsiloxane.

On the other hand, since the release film according to the above embodiment does not include inert particles in the release layer, it is possible to prevent deterioration of the quality of the adhesive surface due to detachment or transfer of the inert particles when applied to the adhesive surface. For example, the content of inorganic inert particles or organic inert particles (crosslinked silicone particles or non-reactive siloxane particles) in the release layer may be less than 0.1 wt%, less than 0.01 wt%, or 0.

The release layer may have a thickness of 0.05 μm to 3 μm. When the thickness of the release layer is 0.05 μm or more, it is advantageous to have a release force required for the release film, and when it is 3 μm or less, it is advantageous to improve the appearance and blocking resistance. For example, the thickness of the release layer may be 0.05 μm or more, 0.1 μm or more, or 0.5 μm or more, and may be 3 μm or less, 2 μm or less, 1.5 μm or less, or 1 μm or less. On the other hand, when the thickness of the release layer is 0.5 µm or more, it is more advantageous to secure a low release force, so the release layer may have a thickness of 0.5 µm to 3 µm.

In addition, the release film according to the embodiment may have excellent blocking resistance even if the release layer is thick due to the antistatic layer. Accordingly, the thickness of the release layer may be 0.5 μm or more, 1 μm or more, and specifically may be 1 μm to 3 μm.

antistatic layer

The antistatic layer is formed on the other surface of the base layer and includes inert particles and a conductive polymer.

The antistatic layer suppresses blocking even when the release layer on the opposite side is thickly formed by providing irregularities due to the inert particles contained therein, and also prevents static electricity that may occur during lamination and peeling with the adhesive surface due to the conductive polymer. maintain the quality of the cotton.

The particle diameter of the inert particles may be, for example, 2 μm to 10 μm. It is advantageous for the particle diameter of the inert particles to be 2 μm or more to form sufficient unevenness for exhibiting blocking resistance, and may be, for example, 2 μm or more, 3 μm or more, 4 μm or more, or 5 μm or more. In addition, it is advantageous for the inert particles to have a particle diameter of 10 μm or less to prevent the shape of irregularities from being transferred to the silicone release layer and the adhesive layer laminated thereto, for example, 10 μm or less, 9 μm or less, 8 μm or less, or 7 ㎛ or less. Specifically, the inert particles may be one or more organic or inorganic inert particles having a particle diameter of 2 μm to 10 μm.

The organic inert particles may be selected from the group consisting of cross-linked silicone particles, cross-linked polyethylene particles, cross-linked polystyrene particles, and cross-linked acrylic particles. The inorganic inert particles may be selected from the group consisting of silicon oxide particles, calcium carbonate particles, titanium oxide particles, and alumina particles.

The inert particles may be included in an amount of 10 to 30% by weight based on the weight of the antistatic layer. More specifically, the content of the inert particles may be 15 to 25% by weight, specifically 15 to 20% by weight based on the weight of the antistatic layer.

The conductive polymer may include polythiophene, polypyrrole, polyaniline, polyethylenedioxythiophene (PEDOT), or a mixture thereof. Specifically, the polymer resin of the antistatic layer may include polyethylenedioxythiophene (PEDOT). More specifically, the polymer resin of the antistatic layer may include polyethylenedioxythiophene polystyrenesulfonate (PEDOT:PSS).

In addition, the antistatic layer may further include a binder resin. For example, the binder resin may have one or more functional groups selected from the group consisting of an acryl group, a urethane group, an amide group, a hydroxyl group, and a silane group. Specifically, the binder resin may be at least one of a thermoplastic resin, a thermosetting resin, and a photocurable resin.

Specific examples of the thermoplastic resin and thermosetting resin include acrylic resin, urethane resin, epoxy resin, urethane acrylate resin, epoxy acrylate resin, cellulose resin, acetal resin, melamine resin, phenol resin, silicone resin , polyester resins, polycarbonate resins, polyethylene resins, polystyrene resins, polyamide resins, polyimide resins, and mixtures thereof.

A photopolymerizable prepolymer that is crosslinked and cured by UV light irradiation may be used as the UV curable resin, and examples of the photopolymerizable prepolymer include cationic polymerization type and radical polymerization type photopolymerizable prepolymer. Examples of the cationic polymerization type photopolymerizable prepolymer include an epoxy-based resin or a vinyl ester-based resin, and the epoxy-based resin includes a bisphenol-based epoxy resin, a novolak-type epoxy resin, an alicyclic epoxy resin, an aliphatic epoxy resin, and These mixtures etc. are mentioned.

The total content of the conductive polymer and the binder resin may be 40 to 80% by weight based on the weight of the antistatic layer. Specifically, the total content of the conductive polymer and the binder resin may be 50 to 70 wt%, more specifically 60 to 70 wt%, based on the weight of the antistatic layer.

In addition, the antistatic layer may further include a curing agent. Examples of the curing agent include an aziridine-based compound, an isocyanate-based compound, an epoxy-based compound, and a metal chelate-based compound, and at least one of these may be used. The content of the curing agent may be 10 to 30% by weight, specifically 15 to 25% by weight, and more specifically 15 to 20% by weight based on the weight of the antistatic layer.

In addition, the antistatic layer may further include other functional additives. For example, the antistatic layer may further include an antistatic agent, a water repellent agent, an antifouling agent, and the like. The content of the functional additive may be 0.1 to 10% by weight based on the weight of the antistatic layer.

The thickness of the antistatic layer may be, for example, 0.01 μm or more, 0.05 μm or more, 0.1 μm or more, or 0.2 μm or more, and 3 μm or less, 1 μm or less, 0.5 μm or less, or 0.3 μm or less. Specifically, the antistatic layer may have a thickness of 0.01 μm to 1 μm. Here, the thickness of the antistatic layer may mean the thickness of only the coating film excluding the inert particles.

In addition, the surface roughness (Ra) of the antistatic layer is 40 nm to 1000 nm is advantageous to minimize haze increase while having blocking resistance, as a specific example 60 nm to 500 nm, 60 nm to 200 nm, or 60 nm to 80 nm.

Relationship between layer thickness and particle size of inert particles

The release film according to the embodiment preferably satisfies a specific relationship between the thickness of each layer and the particle size of the inert particles in order to simultaneously exhibit excellent release properties, blocking resistance and antistatic properties.

As an example, the following equation may be satisfied between the particle size of the inert particles and the thickness of the release layer.

2 ≤ DI/TR ≤ 10 ... (1)

In the above formula, DI is the average particle diameter (μm) of the inert particles, and TR is the thickness (μm) of the release layer.

When it is within the range of the above formula (1), it can be prevented that the blocking resistance is lowered according to the increase in the thickness of the release layer. Specifically, in Formula (1), the DI/TR ratio may be 2 or more, 3 or more, 4 or more, or 5 or more, and may be 10 or less, 9 or less, 8 or less, or 7 or less, and more specifically 2 to 6 , or may be 6 to 10.

As another example, the following equation may be satisfied between the particle size of the inert particles and the thickness of the antistatic layer.

2 ≤ DI/TC ≤ 100 ... (2)

In the above formula, DI is the average particle diameter (μm) of the inert particles, and TC is the thickness (μm) of only the coating film excluding the inert particles in the antistatic layer.

When within the range of the formula (2), the inert particles may not fall off while ensuring blocking resistance. Specifically, in Formula (2), the DI/TC ratio may be 2 or more, 5 or more, 10 or more, or 15 or more, and may be 100 or less, 80 or less, 60 or less, or 40 or less, and more specifically 2 to 40 , or 10 to 60 days.

delete

additional coating layer

The release film may further include an additional coating layer formed between the base layer and the antistatic layer, between the base layer and the release layer, or on the surface of the antistatic layer.

Referring to FIG. 2 , according to another embodiment, the release film 10 may further include an additional coating layer 400 between the base layer 100 and the antistatic layer 300 .

Referring to FIG. 3 , according to another embodiment, the release film 10 may further include an additional coating layer 400 between the base layer 100 and the release layer 200 .

In addition, the release film may further include an additional coating layer formed on the surface of the antistatic layer.

The additional coating layer may be, for example, an antistatic layer, a primer layer, a barrier layer, a hard coating layer, an antifouling layer, a waterproof layer, and the like.

The additional coating layer may include, for example, a curable resin, and may further include other functional additives or fillers. The thickness of the additional coating layer is not particularly limited, but may be, for example, 0.05 μm to 10 μm, or 0.1 μm to 3 μm.

As a specific example, an additional coating layer may be further included between the base layer and the release layer, and the additional coating layer may include a conductive polymer and a thermosetting binder. For example, the additional coating layer may act as an additional antistatic layer by having a composition of a dry coating film excluding only inert particles from the composition of the antistatic layer described above.

Manufacturing method of release film

The method of manufacturing a release film according to the embodiment comprises the steps of: (a) forming a release layer comprising a silicone resin on one surface of a base layer; and (b) forming an antistatic layer comprising inert particles and a conductive polymer on the other surface of the base layer.

The steps (a) and (b) may be performed in their order or in the reverse order, or may be performed simultaneously.

The step (a) may include coating and drying the composition for preparing the release layer on one surface of the base layer.

The release layer composition may be obtained by mixing raw materials such as polydimethylsiloxane and hydrogensiloxane with a catalyst in an organic solvent. Specific types, structures, and usage of the polydimethylsiloxane, hydrogensiloxane, and catalyst are as exemplified above.

As an example, 0.1 to 5 parts by weight of the hydrogensiloxane and 0.01 to 5 parts by weight of the catalyst may be used based on 100 parts by weight of the polydimethylsiloxane. In addition, the organic solvent may be formulated so that the solid content of the release layer composition is 3 to 10% by weight.

The step (b) may include coating the composition for the preparation of the antistatic layer on the other surface of the base layer and drying. In addition, if necessary, a curing process by heating or UV irradiation may be further included.

The antistatic layer composition may be obtained by mixing inert particles, a conductive polymer, and a binder resin with a curing agent and other additives in an organic solvent. Specific types and amounts of the inert particles, the conductive polymer, the binder resin, the curing agent, and the additive are as exemplified above.

As an example, the inert particles may be blended in an amount of 0.001 to 0.1 wt %, specifically 0.005 to 0.05 wt %, based on the weight of the antistatic layer composition (ie, a composition blended with a solvent). In addition, the conductive polymer and the binder resin may be combined in an amount of 0.01 to 10% by weight, specifically 0.01 to 3% by weight, more specifically 0.01 to 1% by weight in total based on the weight of the antistatic layer composition. In addition, the curing agent may be formulated in an amount of 0.001 to 0.1 wt%, specifically 0.005 to 0.05 wt%, based on the weight of the antistatic layer composition. In addition, the organic solvent may be formulated so that the solid content in the antistatic layer composition is 0.01 to 10% by weight, specifically 0.01 to 1% by weight.

As a specific example, the antistatic layer composition may improve workability by using a mixture of a conductive polymer, a polyurethane aqueous dispersion resin, alcohol, and distilled water. In addition, the antistatic layer composition may include a water-soluble or organic solvent type binder resin.

Examples are described below, but the scope of implementation is not limited thereto.

Example 1

Step 1) For the preparation of the antistatic layer composition, based on 100% by weight of the total composition, a polymer resin (Echemtech, CX0003) having a solid content of 3.7% by weight in which a conductive polymer (PEDOT) and a thermosetting binder are mixed (Echemtech, CX0003) 1% by weight, aziridine-based 0.01% by weight of a curing agent (Magtech, CX100), 0.01% by weight of organic inert particles (crosslinked silicone particles) having an average particle diameter of 4 μm, and the remaining amount of a solvent (pure water and methanol) were blended. After applying the prepared antistatic layer composition to one side of a 50 μm thick PET film so that the dry coating film thickness becomes 0.2 μm, heat-drying at 150° C. for 30 seconds, and aging at 60° C. for 1 day for post-curing. An antistatic layer was formed.

Step 2) 5 wt% of polydimethylsiloxane having a hexenyl group (Dow Corning, LTC-750A), hydrogensiloxane (Dow Corning, 7028) based on 100 wt% of the total composition for preparing the release layer composition 0.2% by weight and 350 ppm of the platinum catalyst were blended, and the remaining amount of the solvent (toluene and methyl ethyl ketone) was blended. The release layer composition was coated on the other surface of the PET film coated with the antistatic layer to have a dry coating thickness of 1 μm, and dried by heating at 150° C. for 30 seconds to form a release layer, thereby preparing a release film having a three-layer structure.

Example 2

The same procedure as in Example 1 was followed, but in step 2, the release layer composition was applied to one surface of the PET film so that the dry film thickness was 0.5 μm, to prepare a release film having a three-layer structure.

Example 3

The same procedure as in Example 1 was performed, except that the content of the organic inert particles in the antistatic layer composition in step 1 was blended to 0.005% by weight to prepare a release film having a three-layer structure.

Comparative Example 1

The same procedure as in Example 1 was performed, except that in step 1, organic inert particles were not added to the antistatic layer composition, and a release film having a three-layer structure was prepared.

Comparative Example 2

The same procedure as in Example 2 was performed, except that in step 1, organic inert particles were not added to the antistatic layer composition, and a release film having a three-layer structure was prepared.

Comparative Example 3

The same procedure as in Comparative Example 1 was performed, except that 0.5 wt% of non-reactive siloxane (Wacker, AR200) was additionally added to the release layer composition in step 2 to prepare a release film having a three-layer structure.

test example

The release films of Examples and Comparative Examples were tested as follows.

(1) release layer thickness

The dry thickness of the release layer coated on the base layer was quantitatively measured using an X-ray fluorescence (XRF) measuring device.

(2) release peel force

The adhesive side of a standard adhesive tape (TESA7475) was laminated on the surface of the release layer of the release film, and left at room temperature for 30 minutes. Thereafter, a peel test was performed under the conditions of 180° and 0.3 m/min to measure the release peel force (gf/25mm).

(3) blocking evaluation

In a state in which the release film is wound on a roll or in a state in which the release films are laminated, the degree of adhesion between the films was checked and classified as follows.

Blocking evaluation: (low risk of occurrence) 0 - 1 - 2 - 3 - 4 - 5 (high risk of occurrence)

(4) Residual adhesion rate

a. The release layer of the release film was attached to the adhesive side of a standard tape (Nitto31B, 1 inch), and pressed once using a 2 kg rubber roll, and then at room temperature under a load of 20 g/cm 2 for 24 hours. aged. Then, the standard tape was removed from the release film and attached to the PET film, and then aged at room temperature under a load of 20 g/cm 2 for 30 minutes. The release peel force (A) of a standard tape from a standard substrate at 180° and 300 mm/min was measured using a peel tester.

b. Attach a Teflon film to the adhesive side of a standard tape (Nitto31B, 1 inch), press it once using a 2 kg rubber roll, and then apply a load of 20 g/cm2 at room temperature for 24 hours. aged for a while. Then, the standard tape was peeled off the Teflon film and attached to the PET film, and then aged at room temperature under a load of 20 g/cm 2 for 30 minutes. The release peel force (B) of the standard tape at 180° and 300 mm/min from the standard substrate was measured using a peel tester.

c. Residual adhesive force was calculated according to the following formula: Residual adhesive rate (%) = (Release peel force (A) / Release peel force (B)) X 100

(5) surface resistance

The surface resistance of the release film to the antistatic layer was measured at three points (Treck Inc., Treck 152-1) to obtain an average value.

division release layer antistatic layer Thickness (㎛) Additives (content ^* ) Additives (content ^* ) Example 1 1.012 - Inert particles (0.01% by weight) Example 2 0.520 - Inert particles (0.01% by weight) Example 3 1.033 - Inert particles (0.005% by weight) Comparative Example 1 1.006 - - Comparative Example 2 0.503 - - Comparative Example 3 0.529 unreacted siloxane (0.5 wt%) - * Additive content: The content of additives in the composition applied for the production of each layer

division release peel force
(gf/inch) blocking evaluation Residual adhesion rate
(%) surface resistance
(Ω/□) Example 1 2.8 One 93 10 ⁶ Example 2 3.8 0 96 10 ⁷ Example 3 3.0 2 92 10 ⁵ Comparative Example 1 2.9 5 93 10 ⁶ Comparative Example 2 4.2 4 94 10 ⁵ Comparative Example 3 3.5 3 83 10 ⁶

As shown in the table above, the release films of Examples 1 to 3 added inert particles to the antistatic layer, so that the release peeling force was 4.0 gf/inch or less, while the risk of blocking and surface resistance were low, and the residual adhesion rate was 90% was higher than In particular, the release films of Examples 1 and 2 had an appropriate content of inert particles in the antistatic layer, so that the risk of blocking was low even if the silicone release layer was thick, or the release peel force was 4.0 gf/inch or less even if the silicone release layer was thin. was maintained.

On the other hand, the release film of Comparative Examples 1 to 3 had reduced blocking resistance as a result of not adding inert particles to the antistatic layer, and in particular, the release film of Comparative Example 1 was evaluated to have significantly poor blocking resistance to the extent that it was impossible to apply the process. became On the other hand, in Comparative Examples 2 and 3, the blocking resistance was slightly improved by reducing the thickness of the silicone release layer. Meanwhile, in Comparative Example 3, a non-reactive siloxane was added to the silicone release layer to lower the release peeling force, but the non-reactive siloxane was transferred to the adhesive layer, so that the residual adhesive rate was low.

When non-reactive siloxane is added while making the silicone release layer thin as described above, the release peel force can be lowered, but it is expected that it will be difficult to apply to a process requiring excellent quality due to a low residual adhesion rate. On the other hand, when inert particles are added by forming a coating layer on the opposite side of the release layer, excellent release properties required in the recent processing process using an optical adhesive film can be realized even if the silicone release layer is thickened.

The release film according to the embodiment may be used to protect the adhesive surface of various adhesive products used in the recently growing display field. In particular, the release film is suitable as a silicone release film having a large area, a fast peeling rate, and light release characteristics required in fields such as TSP and OLED displays in recent years.

10: release film;
100: base layer, 200: release layer,
300: antistatic layer, 310: inert particles,
400: additional coating layer.

Claims (14)

base layer;
a release layer formed on one surface of the base layer and comprising a silicone resin; and
It is formed on the other surface of the base layer and includes an antistatic layer comprising inert particles and a conductive polymer,
A release film, wherein the release layer has a release peel force of 4.0 gf / inch or less with respect to the TESA 7475 tape, and the residual adhesive rate according to the following formula is measured to be 90% or more:
Residual adhesion rate (%) = (Release peel force A / Release peel force B) X 100
Here, the release peel force A is the release peel force (gf/inch) measured by attaching the Nitto 31B tape to the release layer and then attaching it to a polyethylene terephthalate (PET) film, and the release peel force B is the Nitto 31B tape is the release peel force (gf/inch) measured by attaching and peeling off the Teflon film and attaching it to the PET film.
The method of claim 1,
A release film, wherein the release layer has a thickness of 0.05 μm to 3 μm.
delete delete delete The method of claim 1,
The surface roughness (Ra) of the antistatic layer is 40 nm to 1000 nm, the release film.
The method of claim 1,
The release film has a surface resistance of 10 ⁵ Ω/□ to 10 ⁹ Ω/□.
The method of claim 1,
The release film, wherein the inert particles are one or more organic or inorganic inert particles having a particle diameter of 2 μm to 10 μm.
9. The method of claim 8,
The release film, wherein the inert particles are included in an amount of 10 to 30% by weight based on the weight of the antistatic layer.
The method of claim 1,
The base layer is a transparent polymer film having a thickness of 25 μm to 125 μm, a release film.
The method of claim 1,
The release film, wherein the release layer includes an addition reaction type silicone resin obtained by reacting polydimethylsiloxane having a vinyl group or a hexenyl group with hydrogen siloxane under a catalyst.
The method of claim 1,
The conductive polymer of the antistatic layer, the release film comprising polyethylenedioxythiophene polystyrene sulfonate (PEDOT: PSS).
The method of claim 1,
The antistatic layer having a thickness of 0.01 μm to 1 μm, a release film.
The method of claim 1,
The release film further includes an additional coating layer between the base layer and the release layer, wherein the additional coating layer includes a conductive polymer and a thermosetting binder.

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