WO2025110382A1 - Polyester film and component comprising same - Google Patents

Abstract

Disclosed are a polyester film and a component comprising same. The polyester film comprises: a polyester substrate; and a cured layer of a silicone emulsion composition located on at least one surface of the polyester substrate, wherein the silicone emulsion composition comprises two or more types of silicone-based resins and a surfactant, the weight average molecular weight of at least one type of the silicone-based resins is 3000 to 7000 Dalton, and the surface energy of the cured layer may be 15 to 20 dyne/cm. Pin holes are substantially not generated within the polyester film, and the polyester film has low peel strength and improved residual adhesion while having excellent adhesive wettability.

Description

Polyester film and parts containing the same

The present disclosure relates to a polyester film and a component comprising the same.

A release film is a film that has a release property that does not adhere well to an adhesive component, and is used as a protective film for adhesive films or adhesive tapes. A release film is used to prevent an adhesive from unintentionally adhering to an adherend before use, or to prevent contamination by foreign substances, etc. A release film is also used to prevent a mold and a molded product from adhering to each other during a heating and pressurizing molding process, or as a carrier film for molding thin ceramic sheets such as dielectrics for multilayer ceramic capacitors.

Polyester film is mainly used as a substrate for the release film. Generally, a release layer is formed on a polyester substrate film using a silicone-based release composition containing a silicone-based resin, a curing agent, a catalyst, etc. The adhesive is directly applied to the polyester film coated with this silicone-based release composition for use. At this time, depending on the type of solvent used in the adhesive or the coating thickness, defects such as orange peel and pinholes may occur, which may lower the quality.

Therefore, there is still a need for polyester films and components comprising the same that have low pinholes, excellent adhesive wettability, low peel strength and improved residual adhesion.

One aspect is to provide a polyester film having excellent adhesive wettability, low peel strength and improved residual adhesion while having almost no pinholes.

Another aspect is to provide a component comprising the polyester film.

According to one aspect,

Polyester substrate; and

A cured layer of a silicone emulsion composition located on at least one side of the polyester substrate;

The above silicone emulsion composition comprises two or more silicone resins and a surfactant,

At least one of the above silicone resins has a weight average molecular weight of 3,000 to 7,000 daltons,

A polyester film is provided, wherein the surface energy of the cured layer is 15 dyne/cm to 20 dyne/cm.

The above silicone resin includes first particles and second particles, and the average particle diameter (D50) of the first particles and second particles may be from 0.1 nm to 300 nm.

The above silicone resin may be selected from polysiloxane containing an alkenyl group having 2 to 6 carbon atoms, polysiloxane containing an alkyl group having 1 to 10 carbon atoms, hydrogen polysiloxane, and combinations thereof.

The above silicone resin may include an alkenyl group-containing polysiloxane represented by the following chemical formula 1:

[Chemical Formula 1]

During the meal,

m and n can be integers from 10 to 500, respectively.

R ₁ , R ₂ , and R ₃ can independently be a C1 to C3 alkyl group, a C2 to C6 alkenyl group, or a combination thereof,

However, at least one of R ₁ , R ₂ , and R ₃ may be an alkenyl group having C2 to C6.

The above silicone resin may include an alkyl group-containing polysiloxane represented by the following chemical formula 2:

[Chemical formula 2]

During the meal,

a and b can each be integers from 1 to 100,

R ₄ , R ₅ , R _{6 ,} R _{7 ,} R _{8 ,} R _{9 ,} R _{10 ,} R _{11 ,} R _{12 ,} R ₁₃ can independently be a hydrogen atom, a C1 to C10 alkyl group, or a combination thereof,

However, at least one of R ₄ , R ₅ , R _{6 ,} R _{7 , R 8 ,} R 9 _{, R 10 ,} R _{11 ,} R _{12 , and} R ₁₃ may be a C1 to C10 alkyl group.

The solid content of the above silicone resin may be 0.1 to 9 parts by weight based on 100 parts by weight of the entire silicone emulsion composition.

The above surfactant may include a diol-based compound, a succinate-based compound, a salt thereof, or a combination thereof.

The above surfactant may include a diol compound represented by the following chemical formula 3:

[Chemical Formula 3]

During the meal,

p, q, r, s can be 0 to 20, respectively.

R ₁ , R ₄ are each independently a hydrogen atom, a halogen atom, a cyano group, an amino group, a hydroxy group, -C(=O), -C(=O)OR _a , -C(=O)OH, a substituted or unsubstituted C3 to C10 alkyl group, a substituted or unsubstituted C2 to C20 alkenyl group, a substituted or unsubstituted C3 to C20 alkynyl group, a substituted or unsubstituted C3 to C10 alkoxy group, a substituted or unsubstituted C6 to C30 aryl group, or a combination thereof, wherein R _a may be a C1 to C5 alkyl group,

R ₂ and R ₃ can independently be a hydrogen atom, a substituted or unsubstituted C1 to C5 alkyl group, or a combination thereof.

The surfactant may include sodium dioctyl 2-(sulfoethyl)succinate, sodium dioctyl 2-(phosphoethyl)succinate, dioctyl 2-(hydroxyethyl)succinate, or a combination thereof.

The content of the above surfactant may be 0.01 to 0.2 parts by weight based on 100 parts by weight of the entire silicone emulsion composition.

The above silicone emulsion composition may further include at least one of a silane coupling agent, a curing agent, and a catalyst.

The above silane coupling agent may include an alkoxy-based silane compound.

The above catalyst may include a metal catalyst.

The thickness of the above-mentioned hardened layer can be 0.01 ㎛ to 10 ㎛.

The above-mentioned material may be a biaxially oriented polyester film.

The thickness of the above-mentioned substrate may be from 10 ㎛ to 300 ㎛.

The above film may be a release film.

According to another aspect,

A component comprising the aforementioned polyester film is provided.

A polyester film according to one aspect comprises a polyester substrate and a cured layer of a silicone emulsion composition positioned on at least one surface of the polyester substrate, wherein the silicone emulsion composition comprises two or more silicone resins and a surfactant, wherein at least one of the silicone resins has a weight average molecular weight of 3000 to 7000 daltons, and the surface energy of the cured layer is 15 to 20 dyne/cm. The polyester film hardly generates pinholes, has excellent adhesive wettability, low peel strength, and improved residual adhesive ratio.

Figure 1 is a cross-sectional schematic diagram of a polyester film according to one embodiment.

Hereinafter, the polyester film and the component including the same will be described in detail with reference to the embodiments and drawings of the present invention. These embodiments are presented only as examples to more specifically explain the present invention, and it will be apparent to those skilled in the art that the scope of the present invention is not limited by these embodiments.

The term "including" in this specification means that, unless specifically stated to the contrary, it may include other components rather than excluding other components.

As used herein, the term "and/or" is meant to include any and all combinations of one or more of the items described herein. As used herein, the term "or" means "and/or." The expression "at least one" or "one or more" preceding an element in this specification may supplement the entire list of elements and not necessarily supplement individual elements of the description.

The term "combination of these" as used herein means a mixture or combination of one or more of the described components.

When an element is referred to herein as being "on" or "over" another element, the element may be directly on the other element, or there may be intervening elements between the elements. Conversely, when an element is referred to as being "directly on" or "directly over" another element, there may not be intervening elements.

In this specification, the terms “~-based resin”, “~-based polymer”, or/and “~-based copolymer” are broad concepts that include all of “~ resin”, “~ polymer”, “~ copolymer”, or/and “derivatives of ~ resin, polymer, or copolymer”.

In this specification, each component is a concept that includes both singular and plural.

Unless stated otherwise herein, all percentages, parts, ratios, etc. are by weight. Also, whenever an amount, concentration, or other value or parameter is given as a range, a preferred range, or a list of upper preferred values and lower preferred values, this should be understood to specifically disclose all ranges formed from any pair of any upper range limit or preferred value and any lower range limit or preferred value, regardless of whether ranges are separately disclosed. Whenever a range of numerical values is recited herein, unless stated otherwise, the range is intended to include the endpoints thereof and all integers and fractions therein. The scope of the invention is not intended to be limited to the specific values recited in defining a range.

Unless otherwise specified, the units “parts by weight” and “weight %” refer to the weight ratio between each component, and the units “parts by mass” and “mass %” refer to the weight ratio between each component converted into solid content.

As used herein, "about" means within an acceptable range of deviation for a particular value as determined by one of ordinary skill in the art, taking into account the error associated with the measurement and measurement of the particular quantity, including the stated value (i.e., the limits of the measurement system). For example, "about" can mean within one or more standard deviations, or within ±30%, 20%, 10%, or 5% of the stated value.

Throughout this specification, the terms “one embodiment,” “an embodiment,” and the like mean that a particular element described in connection with the embodiment is included in at least one embodiment described herein and may or may not be present in other embodiments. It should also be understood that the elements described may be combined in any suitable manner across the various embodiments.

Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. It will also be understood that terms defined in commonly used dictionaries, such as terms, should be interpreted as having a meaning consistent with their meaning in the relevant art and the meaning of this disclosure, and should not be interpreted as idealized. Or, they should not be interpreted in an overly formal sense.

Generally, a release film coated with a silicone-based release composition is used for bonding purposes. As mobile and IT devices become smaller, various types of tapes are being made thinner by directly applying a thin adhesive to the release film and transferring the formed adhesive layer to a substrate. At this time, depending on the surface characteristics of the release film, the adhesive may not be applied properly or the coating quality may deteriorate, such as pinholes or orange peel, after drying.

Taking these points into consideration, the inventors of the present invention propose an invention for the following polyester film.

Figure 1 is a cross-sectional schematic diagram of a polyester film according to one embodiment.

Referring to FIG. 1, a polyester film according to one embodiment has a substrate (20) and a curing layer (or a release layer) (10) disposed on both sides of the substrate (20). Alternatively, a polyester film according to one embodiment may have a substrate (20) and a curing layer (or a release layer) (10) disposed on one side of the substrate (20).

The substrate (20), curing layer (or release layer) (10), and components constituting the polyester film are specifically described as follows.

[Description (20)]

The substrate (20) used in the present invention may use a polyester film or sheet. For example, a polyester film may be used as the substrate (20).

For example, the polyester film may be a polyester film disclosed in Korean Patent Registration No. 10-1268584, Korean Patent Publication No. 2012-45213, and Korean Patent Publication No. 2012-99546.

However, in one embodiment of the present invention, in order to explain only the features of the present invention, a polyester film is described without limitation, but it should be understood that it includes technical features related to a known polyester film.

The polyester film may include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, or polycarbonate.

For example, the polyester film can be a polyethylene terephthalate (PET) film. The polyethylene terephthalate (PET) film has excellent physical stability over a wide temperature range from low to high temperatures, and has excellent chemical resistance, mechanical strength, and surface properties. In addition, the polyethylene terephthalate (PET) film has good thickness uniformity and excellent adaptability to process conditions for various applications.

The polyester resin forming the base film of the present invention may be a polyester obtained by polycondensing dicarboxylic acid and glycol.

Examples of dicarboxylic acids may include aromatic dicarboxylic acids such as isophthalic acid, phthalic acid, terephthalic acid, 2,6-naphthalenedicarboxylic acid, p-oxybenzoic acid, diphenylcarboxylic acid, diphenylsulfonic dicarboxylic acid, diphenoxyethanedicarboxylic acid, and 5-sodiumsulfonic dicarboxylic acid; aliphatic dicarboxylic acids such as succinic acid, adipic acid, sebacic acid, dimer acid, maleic acid, and fumaric acid; alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid; and oxycarboxylic acids such as p-hydroxybenzoic acid; etc.

Examples of glycols may include aliphatic glycols such as ethylene glycol, propanediol, diethylene glycol, propylene glycol, butanediol, pentanediol, hexanediol, and neopentyl glycol; polyalkylene glycols such as polydiethylene glycol, polyethylene glycol, and polypropylene glycol; alicyclic glycols such as cyclohexane dimethanol; and aromatic glycols such as bisphenol A and bisphenol S.

Polyester film can use a uniaxial or biaxially oriented film that has high transparency and excellent productivity and processability. For example, polyester film can use a biaxially oriented film.

Corona treatment, etc. can be performed on the surface of the substrate (20).

The surface tension of the substrate (20) may be 1.0 to 1.5 times that of the silicone emulsion composition. If the surface tension of the substrate (20) is less than 1.0 times, the adhesive wettability is reduced, making it impossible to obtain a uniform cured layer (10), and if the surface tension is more than 1.5 times, coagulation of the silicone emulsion composition may occur, resulting in appearance defects such as pinholes.

Optionally, the polyester film may contain particles to impart excellent roll-to-roll running properties; any particles added may be used without limitation as long as they exhibit excellent sliding properties.

Examples of such particles may include particles of silica, silicon oxide, calcium carbonate, calcium sulfate, calcium phosphate, magnesium carbonate, magnesium phosphate, barium carbonate, kaolin, aluminum oxide, titanium oxide, etc., and the shape of the particles used is not limited, but for example, any of spherical, block-shaped, rod-shaped, and plate-shaped particles may be used.

There are no restrictions on the hardness, specific gravity, and color of the particles, 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 ㎛, and for example, particles in the range of 0.1 to 2 ㎛ may be used. At this time, if the average particle diameter of the particles is less than 0.1 ㎛, agglomeration between particles may occur, resulting in poor dispersion, and if the average particle diameter of the particles exceeds 5 ㎛, the surface roughness characteristics of the film may deteriorate, resulting in poor coating during post-processing.

When particles are included in the polyester film, the content of the particles may be 0.01 to 5 wt% based on the total weight of the polyester film, for example, 0.01 to 3 wt%. When the content of the particles is less than 0.01 wt%, the slip properties of the polyester film may deteriorate, resulting in deteriorated running properties between rolls, and when the content of the particles exceeds 5 wt%, the surface smoothness of the film may deteriorate.

The thickness of the polyester film is not limited, but may be from 10 ㎛ to 300 ㎛.

If the polyester film is too thin, less than 10 ㎛, it may become deformed by heat treatment during processing, and is therefore not suitable as a carrier film. If it is too thick, exceeding 300 ㎛, heat may not be sufficiently transferred, which may cause problems with curing and reduce cost efficiency.

[Curing layer or heterogeneous layer (10)]

The cured layer or release layer (10) according to one embodiment may be a cured layer of a silicone emulsion composition. The silicone emulsion composition can be obtained by blending each component by a conventional method.

The silicone emulsion composition may contain two or more silicone resins and a surfactant.

The weight average molecular weight of at least one silicone resin may be from 3,000 to 7,000 daltons. If the weight average molecular weight of at least one silicone resin is within the above range, compatibility with various polar solvents of the adhesive applied on the cured layer (10) is high, so that adhesive wettability is excellent, and thus pinhole defects on the surface of the polyester film may hardly occur.

The silicone-based resin includes first particles and second particles, and the average particle diameter (D50) of the first particles and the second particles may be 0.1 nm to 300 nm. The first particles may be alkenyl group-containing polysiloxane particles represented by the chemical formula 1 described below, and the second particles may be alkyl group-containing polysiloxane particles represented by the chemical formula 2 described below. Alternatively, conversely, the first particles may be alkyl group-containing polysiloxane particles represented by the chemical formula 2 described below, and the second particles may be alkenyl group-containing polysiloxane particles represented by the chemical formula 1 described below. When the average particle diameter (D50) of the first particles and the second particles of the silicone-based resin is within the above range, compatibility with various polar solvents of the adhesive applied on the curing layer (10) is high, so that adhesive wettability is excellent, and thus pinhole defects on the surface of the polyester film may hardly occur.

The shape of the first particle and the second particle of the silicone resin is not limited, but may be, for example, spherical, elliptical, etc. The average particle diameter (D50) of the first particle and the second particle of the silicone resin refers to the particle size or median particle size corresponding to 50% in a distribution curve of particles accumulated in order of particle diameter from the smallest particle to the largest particle, where the total number of accumulated particles is 100%. The average particle diameter (D50) of the first particle and the second particle of the silicone resin can be measured by a method known to those skilled in the art, for example, using a laser diffraction particle-size analyzer. The median particle size can closely correspond to the arithmetic mean particle diameter calculated from an electron microscope image.

The silicone resin may be selected from polysiloxanes containing alkenyl groups having 2 to 6 carbon atoms, polysiloxanes containing alkyl groups having 1 to 10 carbon atoms, hydrogen polysiloxanes, and combinations thereof.

For example, the silicone resin may include an alkenyl group-containing polysiloxane represented by the following chemical formula 1:

[Chemical Formula 1]

During the meal,

m and n can be integers from 10 to 500, respectively.

R ₁ , R ₂ , and R ₃ can independently be a C1 to C3 alkyl group, a C2 to C6 alkenyl group, or a combination thereof,

However, at least one of R ₁ , R ₂ , and R ₃ may be an alkenyl group having C2 to C6.

Here, m and n do not mean block bonding, but mean that the sum of each structural unit is m and n. In chemical formula 1, each structural unit can be randomly bonded or block bonded. For example, two or more of R ₁ , R ₂ , and R ₃ can be alkenyl groups having C2 to C6.

For example, the silicone resin may include an alkyl group-containing polysiloxane represented by the following chemical formula 2:

[Chemical formula 2]

During the meal,

a and b can each be integers from 1 to 100,

R ₄ , R ₅ , R _{6 ,} R _{7 ,} R _{8 ,} R _{9 ,} R _{10 ,} R _{11 ,} R _{12 ,} R ₁₃ can independently be a hydrogen atom, a C1 to C10 alkyl group, or a combination thereof,

However, at least one of R ₄ , R ₅ , R _{6 ,} R _{7 , R 8 ,} R 9 _{, R 10 ,} R _{11 ,} R _{12 , and} R ₁₃ may be a C1 to C10 alkyl group.

Here, a and b do not mean block bonding, but rather that the sum of each structural unit is a and b. In chemical formula 2, each structural unit can be randomly bonded or block bonded.

The content of the alkyl group-containing polysiloxane represented by chemical formula 2 may be 2 to 10 parts by weight based on 100 parts by weight of the alkenyl group-containing polysiloxane represented by chemical formula 1. For example, the content of the alkyl group-containing polysiloxane represented by chemical formula 2 may be 4 to 6 parts by weight based on 100 parts by weight of the alkenyl group-containing polysiloxane represented by chemical formula 1. If the content of the alkyl group-containing polysiloxane represented by chemical formula 2 is less than 2 parts by weight, unreacted alkenyl group-containing polysiloxane represented by chemical formula 1 may be transferred to another layer, such as the back surface or the adhesive layer of the polyester film, which may cause process contamination. If the content of the alkyl group-containing polysiloxane represented by chemical formula 2 exceeds 10 parts by weight, unreacted polysiloxane may remain in the cured layer (10), which may increase the peeling strength, and the peeling strength may also increase over time, making it difficult to have stable release properties.

Here, the alkenyl group-containing polysiloxane represented by chemical formula 1 and the alkyl group-containing polysiloxane represented by chemical formula 2 may be at least one of linear, branched, radial and cyclic.

The solid content of the silicone resin may be 0.1 to 9 parts by weight based on 100 parts by weight of the entire silicone emulsion composition. If the solid content of the silicone resin is less than 0.1 parts by weight, the minimum release characteristics required for peeling after laminating with the substrate (20) are not implemented. If the solid content of the silicone resin is more than 9 parts by weight, the silicone component on the surface of the cured layer (10) is transferred to the other side, so a winding problem occurs due to the slippage of the back side, and the physical properties may be deteriorated due to the silicone component transferred to the substrate (20) after laminating with the substrate (20).

The surfactant may include a diol compound, a succinate compound, a salt thereof, or a combination thereof.

For example, the surfactant may include a diol compound represented by the following chemical formula 3:

[Chemical Formula 3]

During the meal,

p, q, r, s can be 0 to 20, respectively.

R ₁ , R ₄ are each independently a hydrogen atom, a halogen atom, a cyano group, an amino group, a hydroxy group, -C(=O), -C(=O)OR _a , -C(=O)OH, a substituted or unsubstituted C3 to C10 alkyl group, a substituted or unsubstituted C2 to C20 alkenyl group, a substituted or unsubstituted C3 to C20 alkynyl group, a substituted or unsubstituted C3 to C10 alkoxy group, a substituted or unsubstituted C6 to C30 aryl group, or a combination thereof, wherein R _a may be a C1 to C5 alkyl group,

R ₂ and R ₃ can independently be a hydrogen atom, a substituted or unsubstituted C1 to C5 alkyl group, or a combination thereof.

For example, the surfactant may include sodium dioctyl 2-(sulfoethyl)succinate, sodium dioctyl 2-(phosphoethyl)succinate, dioctyl 2-(hydroxyethyl)succinate, or a combination thereof.

The content of the surfactant may be 0.01 part by weight to 0.2 part by weight based on 100 parts by weight of the entire silicone emulsion composition. Alternatively, the content of the surfactant may be 0.01 part by weight to 5 parts by weight or 0.05 part by weight to 1 part by weight based on 100 parts by weight of the alkenyl group-containing polysiloxane represented by the chemical formula 1. If the content of the surfactant is less than 0.01 part by weight, the content as a surfactant is not sufficient, making it difficult to exhibit the effect of improving the appearance of the polyester film coating. If the content of the surfactant exceeds 5 parts by weight, the peeling strength may increase.

The silicone emulsion composition may further include at least one of a silane coupling agent, a curing agent, and a catalyst. The silane coupling agent may be used as an adhesion improver. The silane coupling agent is not limited, but may include an alkoxy silane compound. Examples of the alkoxy silane compound include [3-(2,3-epoxypropoxy)propyl]trimethoxysilane, but the present invention is not limited thereto, and all known alkoxy silane compounds may be used. The content of the silane coupling agent may be 0.1 to 30 parts by weight based on 100 parts by weight of the entire silicone emulsion composition. Accordingly, the aging stability of the cured layer (10) of the polyester film can be secured.

The hardener is a thermosetting hardener, and polyethylene glycol tridecyl ether and the like can be used, but is not limited thereto, and any known curable hardener in the relevant technical field can be used.

The catalyst may include a metal catalyst. The catalyst may use one or more metals or metalloids selected from elements in groups 4 to 14 of the periodic table, and for example, one or more selected from Rh, Pt, Sn, Ti, Pd, Ir, W, and Co. For example, the catalyst may use a platinum chelate catalyst.

The catalyst assists the addition reaction of the alkenyl group-containing polysiloxane represented by the chemical formula 1 and the alkyl group-containing polysiloxane represented by the chemical formula 2. The content of the catalyst may be 1 ppm to 500 ppm, or for example, 5 ppm to 500 ppm, based on the total weight of the cured layer (10). If the content of the catalyst is less than 1 ppm, the reaction of the alkenyl group-containing polysiloxane represented by the chemical formula 1 and the alkyl group-containing polysiloxane represented by the chemical formula 2 does not sufficiently proceed. If the content of the catalyst exceeds 500 ppm, the peeling strength may increase due to the residual catalyst remaining in the cured layer (10).

In some cases, the cured layer (10) may further include one or more of organic and inorganic particles, an antistatic agent, a conductivity improver, a pH regulator, and an antifouling agent.

The inorganic particles may be inorganic particles selected from natural minerals; oxides, hydroxides, sulfides, nitrides, or halides of elements of groups 1 to 4, 11 to 12, 14, and 16 to 18; carbonates, sulfates, acetates, phosphates, phosphites, carboxylates, silicates, titanates, borates, or hydrates thereof; and complex compounds thereof.

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

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

The average particle diameter (D50) of the organic and inorganic particles can be 1 ㎛ to 5 ㎛. For example, the average particle diameter (D50) of the organic and inorganic particles can be 3 ㎛ to 5 ㎛ or 1 ㎛ to 2 ㎛. If the average particle diameter (D50) of the organic and inorganic particles is less than 1 ㎛, sufficient surface roughness cannot be obtained, and thus the blocking phenomenon cannot be prevented. If the average particle diameter (D50) of the above-mentioned organic and inorganic particles exceeds 5 ㎛, it may act as a defect in the film.

The antistatic agent may be a known antistatic agent widely used in the field of the polyester film, but may be selected from, for example, PEDOT (Poly(3,4-ethylenedioxythiophene)), PEDOT:PSS (poly(3,4-ethylenedioxythiophene) polystyrene sulfonate), polyaniline, polypyrrole, quaternary ammonium salts, sulfonates, phosphates, and combinations thereof. The content of the antistatic agent may be 1 part by weight to 20 parts by weight based on 100 parts by weight of the entire silicone emulsion composition.

The conductivity improver may be a known conductivity improver widely used in the field of the polyester film, and may be selected from, for example, ethylene glycol, dimethyl sulfoxide, N-methyl-2-pyrrolidone, propylene glycol, butyl glycol, dipropylene glycol dimethyl ether, gamma-butyrolactone, sulfolane, dimethyl carbonate, sorbitol, and combinations thereof. The content of the conductivity improver may be 1 part by weight to 20 parts by weight based on 100 parts by weight of the entire silicone emulsion composition.

The pH regulator may be a known pH regulator widely used in the field of the polyester film, but may be selected from, for example, sodium hydroxide, potassium hydroxide, calcium hydroxide, ammonia water, and combinations thereof. The content of the conductivity improver may be 0.05 to 0.3 parts by weight based on 100 parts by weight of the entire silicone emulsion composition.

The antifouling agent may be a known antifouling agent widely used in the field of the polyester film, but may be selected from, for example, fluorine, a fluorine-containing silane compound, a fluorine-containing organic compound, self-emulsifying silicone, and combinations thereof. The content of the antifouling agent may be 0.1 to 0.3 parts by weight based on 100 parts by weight of the entire silicone emulsion composition.

The silicone emulsion composition is prepared with water at a solid content of 0.5 wt% to 15 wt%. The cured layer (10) of the polyester film can be formed by applying it to the substrate (20) at least once using a known method such as a bar coat method, a reverse roll coat method, or a gravure roll coat method. If the solid content of the silicone emulsion composition is less than 0.5 wt%, uniform coating is difficult and at the same time, peeling force may increase, and if it exceeds 15 wt%, the coating appearance may be poor and at the same time, adhesion between the cured layer (10) and the substrate (20) may decrease.

The silicone emulsion composition may further contain 0.01 wt% to 10 wt%, for example 0.01 wt% to 5 wt%, of an organic solvent based on the total weight of the silicone emulsion composition to improve applicability or transparency. If the content of the organic solvent exceeds 10 wt%, there is a risk of explosion during the drying, stretching, and heat treatment processes when using an inline coating method.

The organic solvent may be used without limitation as long as it can disperse the solid content of the silicone emulsion composition and apply it onto a substrate, and examples thereof include: aromatic hydrocarbon 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; ketone solvents such as acetone, methyl ethyl ketone, 2-pentanone, 3-pentanone, 2-hexanone, 2-heptanone, 4-heptanone, methyl isobutyl ketone, diisobutyl ketone, acetonylacetone, and cyclohexanone; ester solvents such as ethyl acetate, propyl acetate, isopropyl acetate, butyl acetate, and isobutyl acetate; Examples of solvents that can be used include ether solvents such as diethyl ether, dipropyl ether, diisopropyl ether, dibutyl ether, 1,2-dimethoxy ethane, 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, octamethyl cyclotetrasiloxane, decanemethyl cyclopentasiloxane, tris(trimethylsiloxy)methylsilane, and tetrakis(trimethylsiloxy)silane; fluorinated solvents such as trifluorotoluene, hexafluoroxylene, methyl nonafluorobutyl ether, and ethyl nonafluorobutyl ether; or mixed solvents thereof. For example, the solvent used in the silicone emulsion composition may include isopropyl alcohol, butyl cellosolve, acetone, methanol, or ethanol.

The surface energy of the cured layer (10) may be 15 dyne/cm to 20 dyne/cm. Within the above range of surface energy of the cured layer (10), pinholes are hardly generated, adhesive wettability is excellent, and low peel strength and improved residual adhesion rate are achieved.

The thickness of the hardened layer (10) may be 0.01 ㎛ to 10 ㎛. If the thickness of the hardened layer (10) is less than 0.01 ㎛, a uniform hardened layer (10) cannot be formed. If the thickness of the hardened layer (10) exceeds 10 ㎛, blocking may occur between one side and the back side of the substrate (20).

[Polyester film]

The polyester film according to one embodiment may be a release film.

A polyester film according to one embodiment may have a peel strength of 20 gf/cm or less at room temperature and a residual adhesion rate of 90% or more.

A polyester film according to one embodiment has almost no pinhole defects.

[part]

A component according to another embodiment of the present invention may include the polyester film described above. Examples of the component may include, but are not limited to, a mobile tape, a foam tape, or a window.

In this specification, the definitions of substituents (groups) used in the chemical formulas described above are as follows.

In the chemical formulas mentioned above, the "substituted" in the "substituted" of the alkyl group, alkoxy group, alkenyl group, alkynyl group, and aryl group means a halogen atom, a C1-C10 alkyl group substituted with a halogen atom (e.g., CCF ₃ , CHCF ₂ , CH ₂ F, CCl ₃ , etc.), a hydroxy group, a nitro group, a cyano group, an amino group, an amidino group, a hydrazine, a hydrazone, a carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid or a salt thereof, or a C1-C10 alkyl group, a C2-C10 alkenyl group, a C2-C10 alkynyl group, a C1-C20 heteroalkyl group, a C6-C20 aryl group, a C6-C20 arylalkyl group, a C6-C20 heteroaryl group, or a C6-C20 heteroarylalkyl group. It means that.

Specific examples of the C1-C10 alkyl group used in the chemical formula described above include methyl, ethyl, propyl, isobutyl, sec-butyl, ter-butyl, neo-butyl, iso-amyl, hexyl, etc., and one or more hydrogen atoms in the alkyl group can be substituted with a substituent as defined in the "substitution" described above.

Specific examples of the C1-C10 alkoxy group used in the chemical formula described above include methoxy, ethoxy, propoxy, etc., and at least one hydrogen atom in the alkoxy group can be substituted with a substituent as defined in the “substitution” described above.

Specific examples of the C2-C10 alkenyl group used in the chemical formula described above include vinylene, allylene, etc., and at least one hydrogen atom in the alkenyl group can be substituted with a substituent as defined in the “substitution” described above.

Specific examples of the C2-C10 alkynyl group used in the chemical formula described above include acetylene, and at least one hydrogen atom in the alkynyl group can be substituted with a substituent as defined in the “substitution” described above.

The C6-C20 aryl group used in the chemical formula described above is used alone or in combination to mean an aromatic system containing one or more rings, and examples thereof include phenyl, naphthyl, tetrahydronaphthyl, etc. In addition, one or more hydrogen atoms in the aryl group may be substituted with a substituent as defined in the "substitution" described above.

Hereinafter, the composition of the present invention and the effects thereof will be described in more detail through examples and comparative examples. However, it will be obvious that the present examples are intended to explain the present invention more specifically, and the scope of the present invention is not limited to these examples.

[Example]

Example 1: Polyester film

A 50 ㎛ thick polyethylene terephthalate (PET) film (Excell-50 ㎛, Toray Advanced Materials) that had been corona-treated was prepared as a substrate.

Separately, 100 parts by weight of alkenyl group-containing polysiloxane particles represented by the following chemical formula 1-1 (Wacker, Dow Corning, D(50): about 200 nm, Mw: about 5,000 Daltons), 5 parts by weight of alkyl group-containing polysiloxane particles represented by the following chemical formula 2-1 (Wacker, Dow Corning, D(50): about 200 nm, Mw: about 5,000 Daltons), 0.8 parts by weight of a diol-based compound surfactant represented by the following chemical formula 3-1, and the remainder of water were mixed to prepare a silicone emulsion composition. The prepared silicone emulsion composition was applied onto a polyethylene terephthalate base film using a bar coater, and hot air dried at a temperature of 180° C. for 50 seconds to form a cured layer to prepare a polyester film.

[Chemical Formula 1-1]

During the meal,

m and n are 60 each,

R ₁ , R ₂ , and R ₃ are each ethenyl groups.

[Chemical Formula 2-1]

During the meal,

a and b are each 50,

R ₄ , R ₅ , R _{7 ,} R _{8 ,} R _{9 ,} R _{10 ,} R _{11 ,} R _{12 ,} R ₁₃ are methyl groups, and R ₆ is a hydrogen atom.

[Chemical Formula 3-1]

During the meal,

p, q, r, and s are each 0,

R ₁ , R ₂ , R ₃ , and R ₄ are each hydrogen atoms.

Example 2: Polyester film

A polyester film was produced in the same manner as in Example 1, except that a silicone emulsion composition was produced using 0.8 parts by weight of sodium dioctyl 2-(sulfoethyl) succinate surfactant instead of the diol compound surfactant represented by the above chemical formula 3-1.

Example 3: Polyester film

A polyester film was produced in the same manner as in Example 1, except that a silicone emulsion composition was produced using 0.8 parts by weight of sodium dioctyl 2-(phosphoethyl) succinate surfactant instead of the diol compound surfactant represented by the above chemical formula 3-1.

Example 4: Polyester film

A polyester film was produced in the same manner as in Example 1, except that a silicone emulsion composition was produced using 0.8 parts by weight of dioctyl 2-(hydroxyethyl) succinate surfactant instead of the diol compound surfactant represented by the above chemical formula 3-1.

Example 5: Polyester film

A polyester film was manufactured in the same manner as in Example 1, except that a silicone emulsion composition was manufactured using 0.03 parts by weight instead of 0.8 parts by weight of the diol compound surfactant represented by the chemical formula 3-1.

Example 6: Polyester film

A polyester film was manufactured in the same manner as in Example 1, except that a silicone emulsion composition was manufactured using 3.0 parts by weight instead of 0.8 parts by weight of the diol compound surfactant represented by the chemical formula 3-1.

Comparative Example 1: Polyester Film

A polyester film was produced in the same manner as in Example 1, except that a silicone emulsion composition was produced using 100 parts by weight of alkenyl group-containing polysiloxane particles represented by the chemical formula 1-1 (Wacker, Dow Corning, D(50): about 400 nm, Mw: about 5,000 Daltons) and 5 parts by weight of alkyl group-containing polysiloxane particles represented by the chemical formula 2-1 (Wacker, Dow Corning, D(50): about 400 nm, Mw: about 5,000 Daltons).

Comparative Example 2: Polyester Film

A polyester film was produced in the same manner as in Example 1, except that a silicone emulsion composition was produced using 100 parts by weight of alkenyl group-containing polysiloxane particles represented by the chemical formula 1-1 (Wacker, Dow Corning, D(50): about 700 nm, Mw: about 10,000 Daltons, in chemical formula 1-1, m and n are 120) and 5 parts by weight of alkyl group-containing polysiloxane particles represented by the chemical formula 2-1 (Wacker, Dow Corning, D(50): about 700 nm, Mw: about 10,000 Daltons, in chemical formula 2-1, a and b are 100).

Comparative Example 3: Polyester Film

A polyester film was produced in the same manner as in Example 1, except that a silicone emulsion composition was produced using 100 parts by weight of alkenyl group-containing polysiloxane particles represented by the chemical formula 1-1 (Wacker, Dow Corning, D(50): about 100 nm, Mw: about 2,500 Daltons, in chemical formula 1-1, m and n are 30) and 5 parts by weight of alkyl group-containing polysiloxane particles represented by the chemical formula 2-1 (Wacker, Dow Corning, D(50): about 100 nm, Mw: about 2,500 Daltons, in chemical formula 2-1, a and b are 25).

Evaluation Example 1: Property Evaluation

The properties of the polyester films manufactured in Examples 1 to 6 and Comparative Examples 1 to 3 were evaluated by the following methods, and the results are shown in Table 1.

(1) Measurement of peeling force (gf/in)

Each polyester film was attached to a cold-rolled stainless steel plate with a double-sided adhesive tape so that the cured layer was on top. TESA7475 acrylic adhesive tape was attached on the cured layer, pressed with a 2 kg roller, and left at room temperature for 7 days, and then the peeling strength was measured. The peeling strength was measured 5 times using the following measuring device and measuring method, and the average value was used as the peeling strength.

Measuring instrument: AR-1000 (Chem-Instrument)

Measurement method: 180° peel angle, 0.3 m/min peel speed

(2) Residual adhesion rate (%)

Each polyester film was cut to a size of 50 mm x 250 mm to prepare a sample. The prepared sample was stored at 25°C, 65% RH for 24 hours. TESA7475 acrylic adhesive tape was attached to the surface of the cured layer and pressed at a load of 20 g/cm ² at room temperature for 24 hours. The TESA7475 acrylic adhesive tape attached to the surface of the cured layer was collected without contamination. The collected TESA7475 acrylic adhesive tape was attached to the surface of a flat and clean polyethylene terephthalate (PET) substrate film and pressed once with a 2 kg roller (ASTMD-1000-55T). The TESA7475 acrylic adhesive tape was peeled from the PET substrate film, and the peeling force was measured using the following measuring device and measuring method.

Separately, unused TESA7475 acrylic adhesive tape was attached to the surface of a polyethylene terephthalate (PET) substrate film with a flat and clean surface, and the tape was pressed once with a 2 kg roller (ASTMD-1000-55T) and the peel strength was measured using the following measuring device and method. Each measured peel strength was substituted into Equation 1 below to obtain the residual adhesion ratio (%).

Measuring instrument: AR-1000 (Chem-Instrument)

Measurement method: 180° peel angle, 0.3m/min peel speed

[Formula 1]

Residual adhesion rate (%) = [(Peel strength of acrylic adhesive tape peeled from the cured layer) / (Peel strength of unused acrylic adhesive tape) x 100]

(3) Surface energy (dyne/cm)

The surface tension and liquid penetration depth of water and diiodomethane were measured for the cured layer of each polyester film. These measured values were substituted into Equation 2 to calculate the surface energy using the Owens-Wendt model.

[Formula 2]

E _s = σ ₁ x ln(kxh)

During the meal,

E _s is the surface energy (J/m ² ), σ ₁ is the surface tension of the liquid (N/m), k is the penetration coefficient (dimensionless), and h is the liquid penetration depth (m).

(4) Number of pinholes (adhesive wetting)

Each polyester film was cut to a size of 10 cm x 10 cm to prepare a sample. An acrylic adhesive was applied to the surface of the cured layer of the prepared sample with a thickness of approximately 10 ㎛, and then the number of pinholes per unit area generated on the applied surface was observed with the naked eye.

Referring to Table 1, the polyester films manufactured by Examples 1 to 6 had almost no pinhole defects, excellent adhesive wetting properties, and exhibited a peel strength of 20 gf/cm or less and a residual adhesion rate of 93% or more. In comparison, the polyester film manufactured by Comparative Example 1 had a large average particle size (D50) of the silicone resin, so there was a problem with the compatibility of the acrylic adhesive with the polar solvent, which resulted in a rapid increase in the number of pinholes. The polyester films manufactured by Comparative Examples 2 and 3 had an excessively low or high weight average molecular weight (Mw) of the silicone resin, which resulted in an increase in the peel strength, and there was a problem with the compatibility of the acrylic adhesive with the polar solvent, which resulted in a rapid increase in the number of pinholes.

Claims (18)

Polyester substrate; and A cured layer of a silicone emulsion composition located on at least one side of the polyester substrate; The above silicone emulsion composition comprises two or more silicone resins and a surfactant, At least one of the above silicone resins has a weight average molecular weight of 3,000 to 7,000 daltons, A polyester film having a surface energy of the cured layer of 15 dyne/cm to 20 dyne/cm. In the first paragraph, A polyester film, wherein the silicone resin comprises first particles and second particles, and the average particle diameter (D50) of the first particles and the second particles is 0.1 nm to 300 nm. In the first paragraph, A polyester film, wherein the silicone resin is selected from an alkenyl group-containing polysiloxane having 2 to 6 carbon atoms, an alkyl group-containing polysiloxane having 1 to 10 carbon atoms, a hydrogen polysiloxane, and a combination thereof. In the first paragraph, A polyester film, wherein the silicone resin comprises an alkenyl group-containing polysiloxane represented by the following chemical formula 1: [Chemical Formula 1]

During the meal, m and n are integers from 10 to 500, respectively. R ₁ , R ₂ , R ₃ are independently a C1 to C3 alkyl group, a C2 to C6 alkenyl group, or a combination thereof, However, at least one of R ₁ , R ₂ , and R ₃ is an alkenyl group having C2 to C6. In the first paragraph, A polyester film, wherein the silicone resin comprises an alkyl group-containing polysiloxane represented by the following chemical formula 2: [Chemical formula 2]

During the meal, a and b are integers from 1 to 100, respectively. R ₄ , R ₅ , R _{6 ,} R _{7 ,} R _{8 ,} R _{9 ,} R _{10 ,} R _{11 ,} R _{12 ,} R ₁₃ are each independently a hydrogen atom, a C1 to C10 alkyl group, or a combination thereof, However, at least one of R ₄ , R ₅ , R _{6 ,} R _{7 , R 8 ,} R 9 _{, R 10 ,} R _{11 ,} R _{12 , and} R ₁₃ is a C1 to C10 alkyl group. In the first paragraph, A polyester film, wherein the solid content of the silicone resin is 0.1 to 9 parts by weight based on 100 parts by weight of the entire silicone emulsion composition. In the first paragraph, A polyester film, wherein the surfactant comprises a diol compound, a succinate compound, a salt thereof, or a combination thereof. In the first paragraph, A polyester film, wherein the surfactant comprises a diol compound represented by the following chemical formula 3: [Chemical Formula 3]

During the meal, p, q, r, and s are 0 to 20, respectively. R ₁ , R ₄ are each independently a hydrogen atom, a halogen atom, a cyano group, an amino group, a hydroxy group, -C(=O), -C(=O)OR _a , -C(=O)OH, a substituted or unsubstituted C3 to C10 alkyl group, a substituted or unsubstituted C2 to C20 alkenyl group, a substituted or unsubstituted C3 to C20 alkynyl group, a substituted or unsubstituted C3 to C10 alkoxy group, a substituted or unsubstituted C6 to C30 aryl group, or a combination thereof, wherein R _a is a C1 to C5 alkyl group, R ₂ and R ₃ are independently a hydrogen atom, a substituted or unsubstituted C1 to C5 alkyl group, or a combination thereof. In the first paragraph, A polyester film, wherein the surfactant comprises sodium dioctyl 2-(sulfoethyl)succinate, sodium dioctyl 2-(phosphoethyl)succinate, dioctyl 2-(hydroxyethyl)succinate, or a combination thereof. In the first paragraph, A polyester film, wherein the content of the surfactant is 0.01 to 0.2 parts by weight based on 100 parts by weight of the entire silicone emulsion composition. In the first paragraph, A polyester film, wherein the silicone emulsion composition further comprises at least one of a silane coupling agent, a curing agent, and a catalyst. In Article 11, A polyester film, wherein the silane coupling agent comprises an alkoxy-based silane compound. In Article 11, A polyester film, wherein the catalyst comprises a metal catalyst. In the first paragraph, A polyester film having a thickness of the cured layer of 0.01 ㎛ to 10 ㎛. In the first paragraph, A polyester film, wherein the above description is a biaxially oriented polyester film. In the first paragraph, A polyester film having a thickness of 10 ㎛ to 300 ㎛ as described above. In the first paragraph, A polyester film, wherein the above film is a release film. An article comprising a polyester film according to any one of claims 1 to 17.

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