Polyester film and assembly comprising the same

Abstract

The invention discloses a polyester film and an assembly comprising the same. The polyester film comprises: a polyester substrate; and a cured layer of a silicone emulsion composition on at least one side of the polyester substrate wherein the silicone emulsion composition comprises two or more silicone-based resins and a surfactant, at least one of the silicone-based resins having a weight average molecular weight of 3,000 Daltons to 7,000 Daltons, and at least one of the silicone-based resins having a weight average molecular weight of 3,000 Daltons to 7,000 Daltons, and at least one of the silicone-based resins having a weight average molecular weight of 3,000 Daltons to 7,000 Daltons. And the surface energy of the cured layer can be 15 dynes / cm to 20 dynes / cm. The present invention relates to a polyester film having substantially no pinholes generated therein, and having low peel strength and improved residual adhesion while having excellent adhesive wettability.

Description

Technical Field

[0001] The present disclosure relates to a polyester film and a component including the polyester film. Background Art

[0002] A release film is a film with a releasable property that prevents it from adhering well to an adhesive substance and is used as a protective film for adhesive films or tapes. Before applying an adhesive, a release film is used to prevent inadvertent adhesion to an adherend or contamination by foreign matter. Release films can also be used to prevent molds and molded parts from sticking during thermoforming and compression molding processes and as a carrier film for forming thin ceramic sheets, such as the dielectric material of laminated ceramic capacitors.

[0003] Release films primarily use polyester film as a backing. Typically, a silicone-based release composition, including a silicone-based resin, a curing agent, a catalyst, and the like, is applied to the polyester backing film to form a release layer. Adhesive is then applied directly to the polyester film coated with the silicone-based release composition. However, depending on the solvent used in the adhesive and the coating thickness, defects such as orange peel and pinholes may occur, resulting in poor quality.

[0004] Thus, there remains a need for a polyester film, and an assembly comprising a polyester film, having low peel strength and improved residual adhesion with minimal pinhole formation and good adhesive wetting. Summary of the Invention

[0005] Technical objectives of the present invention

[0006] One aspect provides a polyester film having low peel strength and improved residual adhesion with minimal pinhole formation and good adhesive wetting.

[0007] Another aspect provides an assembly comprising a polyester film.

[0008] The means used to achieve technical goals

[0009] According to one aspect, there is provided a polyester film, comprising:

[0010] polyester backing; and

[0011] a solidified layer of a silicone emulsion composition, the solidified layer being located on at least one side of the polyester substrate,

[0012] wherein the silicone emulsion composition comprises at least two silicone-based resins and a surfactant,

[0013] At least one of the silicon-based resins has a weight average molecular weight of 3,000 to 7,000 Daltons, and

[0014] The surface energy of the solidified layer is 15 dyne / cm to 20 dyne / cm.

[0015] The silicon-based resin includes first particles and second particles, wherein an average particle diameter D50 of the first particles and the second particles may be 0.1 nm to 300 nm.

[0016] The silicon-based resin may be selected from polysiloxane including a C2-C6 alkenyl group, polysiloxane including a C1-C10 alkyl group, hydrogen polysiloxane, and combinations thereof.

[0017] The silicon-based resin may include a polysiloxane represented by Formula 1 and including an alkenyl group:

[0018] [Formula 1]

[0019]

[0020] Wherein in the formula,

[0021] m and n may each be an integer from 10 to 500, and

[0022] R1, R2 and R3 can each independently be a C1-C3 alkyl, a C2-C6 alkenyl or a combination thereof, wherein

[0023] At least one of R1, R2, and R3 may be a C2-C6 alkenyl group.

[0024] The silicon-based resin may include a polysiloxane represented by Formula 2 and including an alkyl group:

[0025] [Formula 2]

[0026]

[0027] Wherein in the formula,

[0028] a and b may each be an integer from 1 to 100, and

[0029] R4, R5, R6, R7, R8, R9, R 10 、R 11 、R 12 and R 13 can be independently a hydrogen atom, a C1-C10 alkyl group or a combination thereof, wherein

[0030] R4, R5, R6, R7, R8, R9, R 10 、R 11 、R 12 and R 13 At least one of them may be a C1-C10 alkyl group.

[0031] The solid content of the silicon-based resin may be 0.1 parts by weight to 9 parts by weight based on 100 parts by weight of the total content of the silicon emulsion composition.

[0032] The surfactant may include a glycol-based compound, a succinate-based compound, a salt of a compound, or a combination thereof.

[0033] The surfactant may include a compound represented by Formula 3:

[0034] [Formula 3]

[0035]

[0036] Wherein in the formula,

[0037] p, q, r and s can each be 0 to 20,

[0038] R1 and R4 can each independently be a hydrogen atom, a halogen atom, a cyano group, an amino group, a hydroxyl group, -C(=O), -C(=O)OR a , -C(=O)OH, substituted or unsubstituted C3-C10 alkyl, substituted or unsubstituted C2-C20 alkenyl, substituted or unsubstituted C3-C20 alkynyl, substituted or unsubstituted C3-C10 alkoxy, substituted or unsubstituted C6-C30 aryl, or a combination thereof, wherein R a is a C1-C5 alkyl group, and

[0039] R2 and R3 may each independently be a hydrogen atom, a substituted or unsubstituted C1-C5 alkyl group, or a combination thereof.

[0040] The surfactant may include dioctyl 2-(sulfonatoethyl)succinate sodium salt, dioctyl 2-(phosphoethyl)succinate sodium salt, dioctyl 2-(hydroxyethyl)succinate sodium salt, or a combination thereof.

[0041] The surfactant may be included in an amount of 0.01 to 0.2 parts by weight based on 100 parts by weight of the total content of the silicone emulsion composition.

[0042] The silicone emulsion composition may further include at least one of a silane coupling agent, a curing agent, and a catalyst.

[0043] The silane coupling agent may include an alkoxy-based silane compound.

[0044] The catalyst may include a metal catalyst.

[0045] The solidified layer may have a thickness of 0.01 μm to 10 μm.

[0046] The substrate may be a biaxially oriented polyester film.

[0047] The thickness of the substrate may be 10 μm to 300 μm.

[0048] The film may be a release film.

[0049] According to another aspect,

[0050] An assembly comprising a polyester film is provided.

[0051] Advantageous Effects of the Invention

[0052] According to one aspect, a polyester film includes: a polyester substrate; and a cured layer of a silicone emulsion composition, the cured layer being located on at least one side of the polyester substrate. The silicone emulsion composition includes at least two silicone-based resins and a surfactant, at least one of the silicone-based resins having a weight-average molecular weight of 3,000 to 7,000 daltons, and the cured layer having a surface energy of 15 to 20 dynes / cm. The polyester film has low peel strength, improved residual adhesion, minimal pinhole formation, and excellent adhesive wetting. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Figure 1 is a schematic cross-sectional view of a polyester film according to an embodiment. DETAILED DESCRIPTION

[0054] Mode of the Invention

[0055] Hereinafter, the polyester film and the components including the polyester film will be described in detail with reference to the embodiments and drawings of the present disclosure. These examples are presented only by way of example to explain the present disclosure in more detail, and it will be apparent to those skilled in the art that the scope of the present disclosure is not limited by these examples.

[0056] Unless otherwise described, the term "comprising" used in the description of the present invention does not exclude other elements and means that other elements may be further included.

[0057] As used herein, the term "and / or" is intended to include any and all combinations of one or more of the listed items associated therewith. As used herein, the term "or" means "and / or". The expressions "at least one" or "one or more" used before an element in the present specification are intended to supplement the list of all elements and are not intended to supplement individual elements in the specification.

[0058] As used herein, the term "combination thereof" means a mixture or combination of one or more of the aforementioned elements.

[0059] In the present specification, when an element is described as being disposed “on” or “over” another element, the element may be disposed directly on the other element, or intervening elements may be present between the elements. On the other hand, when an element is described as being disposed “directly on” or “directly over” another element, there may be no intervening elements.

[0060] In the present specification, the term "based-resin", "based-polymer" or / and "based-copolymer" is a broad concept, which includes all "-resins", "-polymers", "-copolymers" or / and "derivatives of -resins, -polymers or -copolymers".

[0061] In the specification of the present invention, each element is described as a concept including both the singular and the plural.

[0062] Unless otherwise stated in the present invention specification, all percentages, parts, ratios etc. are all by weight. In addition, when providing amount, concentration or other value or parameter in a scope, preferred range or preferred upper limit or preferred lower limit list, it should be understood that no matter whether described scope is disclosed separately, all scopes formed by any upper limit range or preferred value and any lower limit range or any pair of preferred values ​​should be specifically disclosed. When stating numerical range in the present invention specification, unless otherwise stated, described scope is intended to include its endpoints, and all integers and fractions in the described scope. The scope of the present disclosure is intended to be not limited by the specific value quoted when defining the scope.

[0063] Unless otherwise specified, the unit "parts by weight" or "wt%" means the weight ratio between each component, and the unit "parts by mass" or "mass%" means the value obtained by converting the weight ratio between each component into solid content.

[0064] The expression "about" as used in the present specification includes the values ​​recited herein and also includes values ​​within an acceptable deviation range of the particular value determined by one skilled in the art to take into account the errors associated with the corresponding measurement results and the measurement results of the particular quantity (i.e., the limits of the measurement system). For example, the expression "about" can include values ​​within one or more standard deviations, or ±30%, ±20%, ±10%, or ±5% of the specified value.

[0065] Throughout the present specification, the term "embodiment" or the like means that a particular component described in conjunction with the embodiment is included in at least one embodiment described herein, and that the particular component may or may not be present in other embodiments. In addition, the components described herein should be interpreted as being combinable in any suitable manner in various embodiments.

[0066] Unless otherwise defined, all terms (including technical and scientific terms) used in the present specification have the same meaning as those commonly understood by those skilled in the art to which the present disclosure belongs. In addition, terms defined in commonly used dictionaries should be interpreted as having a meaning consistent with that in the relevant art and the present disclosure, and should not be interpreted as idealized. Alternatively, the terms should not be interpreted in an overly formal sense.

[0067] Typically, release films coated with silicone-based release compositions are used for lamination purposes. As mobile devices and IT equipment become increasingly smaller, various types of adhesive tapes are being manufactured into thin films by applying pressure-sensitive adhesives directly to release films and transferring the resulting pressure-sensitive adhesive layer to a substrate. However, depending on the surface properties of the release film, the adhesive may not be applied properly, or after drying, the coating quality may be degraded by pinholes or orange peel.

[0068] In consideration of these problems, the inventors of the present disclosure have proposed an invention for the following polyester film.

[0069] Figure 1 is a schematic cross-sectional view of a polyester film according to an embodiment.

[0070] refer to Figure 1 The polyester film 10 according to the embodiment includes a substrate 20 and a solidified layer 10 (or release layer) on both sides of the substrate 20. Alternatively, the polyester film 10 according to the embodiment may include a substrate 20 and a solidified layer 10 (or release layer) on one side of the substrate 20.

[0071] The substrate 20 and the curing layer (or release layer) 10 constituting the polyester film and assembly are described in detail below.

[0072] [Substrate 20]

[0073] In order to be used as the substrate 20 in the present disclosure, a polyester film or a polyester sheet can be used. For example, in order to be used as the substrate 20, a polyester film can be used.

[0074] For example, such a polyester film may be the polyester films disclosed in KR 10-1268584, KR 2012-45213, and KR 2012-99546.

[0075] However, in order to describe only the features of the present disclosure, the polyester film is described in the embodiments of the present disclosure, but is not limited thereto, but it should be understood that the embodiments include technical features related to polyester films known in the art.

[0076] The polyester film may include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polycarbonate, or the like.

[0077] For example, the polyester film may be a polyethylene terephthalate (PET) film. PET films have excellent physical stability over a wide temperature range, from low to high temperatures, and possess excellent chemical resistance, mechanical strength, and surface properties. Furthermore, PET films have good uniformity in thickness and are well adapted to the process conditions of various applications.

[0078] To be used as the polyester resin forming the substrate film of the present disclosure, polyester obtained by polycondensation of dicarboxylic acid and diol may be used.

[0079] Examples of dicarboxylic acids may include: aromatic dicarboxylic acids, such as isophthalic acid, phthalic acid, terephthalic acid, 2,6-naphthalene dicarboxylic acid, p-oxybenzoic acid, diphenylcarboxylic acid, diphenylsulfone dicarboxylic acid, diphenoxyethane dicarboxylic acid, 5-sodiumsulfone dicarboxylic acid, etc.; aliphatic dicarboxylic acids, such as succinic acid, adipic acid, sebacic acid, dimer acid, maleic acid, fumaric acid, etc.; alicyclic dicarboxylic acids, such as cyclohexane dicarboxylic acid, etc.; and oxycarbonic acids, such as p-oxybenzoic acid, etc.; and the like.

[0080] Examples of diols may include: aliphatic diols such as ethylene glycol, propanediol, diethylene glycol, propylene glycol, butanediol, pentanediol, hexanediol, neopentyl glycol, etc.; polyalkylene glycols such as polyethylene glycol, polyethylene glycol, polypropylene glycol, etc.; alicyclic diols such as cyclohexanedimethanol, etc.; and aromatic diols such as bisphenol A, bisphenol S, etc.; and the like.

[0081] The polyester film may be a uniaxially or biaxially oriented film having high transparency while providing excellent productivity and processability while being usable. For example, the polyester film may be a biaxially oriented film.

[0082] The surface of the substrate 20 may be subjected to corona treatment or the like.

[0083] The surface tension of the substrate 20 may be 1.0 to 1.5 times the surface tension of the silicone emulsion composition. When 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 when the surface tension is greater than 1.5 times, the silicone emulsion composition may agglomerate, resulting in defects such as pinholes in appearance.

[0084] Optionally, the polyester film may contain particles that impart good roll-to-roll running characteristics, and the use of such particles is not limited as long as the particles added thereto can exhibit good sliding characteristics.

[0085] Examples of the particles may include particles of silica, silicon dioxide, calcium carbonate, calcium sulfate, calcium phosphate, magnesium carbonate, magnesium phosphate, barium carbonate, kaolin, aluminum oxide, titanium dioxide, etc. The shape of the particles used is not limited, and any of the following particles such as spherical, ball-like, spherical-like, rod-like, and plate-like particles may be used.

[0086] The hardness, specific gravity, and color of the particles are not limited, but two or more types may be used in combination as needed, and the average particle size of the particles used may be 0.1 μm to 5 μm, for example, 0.1 μm to 2 μm. Here, when the average particle size of the particles is less than 0.1 μm, agglomeration may occur between the particles, resulting in poor dispersion, and when the average particle size of the particles is greater than 5 μm, the surface roughness of the film may deteriorate, resulting in poor coating during post-processing.

[0087] When the polyester film includes particles, the content of the particles may be 0.01 wt% to 5 wt%, for example, 0.01 wt% to 3 wt%, based on the total weight of the polyester film. When the content of the particles is less than 0.01 wt%, the sliding properties of the polyester film may be poor, resulting in poor roll-to-roll running properties, and when the content of the particles is greater than 5 wt%, the surface smoothness of the film may be poor.

[0088] The thickness of the polyester film is not limited but may be 10 μm to 300 μm.

[0089] When the polyester film is too thin, wherein the thickness is less than 10 μm, the polyester film is not suitable as a carrier film because it may be deformed by heat treatment during processing, and when the polyester film is too thick, wherein the thickness is greater than 300 μm, curing problems may occur due to insufficient heat transfer and reduced economic performance.

[0090] [Cured layer 10 (release layer)]

[0091] The cured layer 10 (or release layer) according to the embodiment may be a cured layer of a silicone emulsion composition. The silicone emulsion composition may be obtained by blending each component in a conventional manner.

[0092] The silicone emulsion composition may include at least two silicone-based resins and a surfactant.

[0093] The weight average molecular weight of at least one of the silicon-based resins may be 3,000 to 7,000 Daltons. When the weight average molecular weight of at least one of the silicon-based resins is within the above range, the adhesive solution applied to the solidified layer 10 may contain various polar solvents and have high compatibility, thereby resulting in excellent adhesive wettability, so that pinhole defects are rarely generated on the surface of the polyester film.

[0094] The silicon-based resin may include first particles and second particles, wherein the average particle size D50 of the first particles and the second particles may be 0.1 nm to 300 nm. The first particles may be polysiloxane particles represented by Formula 1 and including alkenyl groups, and the second particles may be polysiloxane particles represented by Formula 2 and including alkyl groups. Alternatively, on the other hand, the first particles may be polysiloxane particles represented by Formula 2 and including alkyl groups, and the second particles may be polysiloxane particles represented by Formula 1 and including alkenyl groups. When the average particle size D50 of the first particles and the second particles is within the above range, the adhesive solution applied to the solidified layer 10 may contain various polar solvents and have high compatibility, thereby producing excellent adhesive wettability, so that pinhole defects rarely occur on the surface of the polyester film.

[0095] The shape of the first particles and the second particles included in the silicon-based resin is not particularly limited, but may be, for example, spherical, elliptical, etc. The average particle size D50 of the first particles and the second particles included in the silicon-based resin refers to the particle size or median particle size corresponding to 50% of the distribution curve of the particles accumulated in order of particle diameter from the smallest particle to the largest particle relative to 100% of the total number of accumulated particles. The average particle size D50 of the first particles and the second particles included in the silicon-based resin can be measured by a person of ordinary skill in the art using a known method such as laser diffraction particle size analysis. The median particle size may closely correspond to the arithmetic mean particle size calculated from an electron microscope image.

[0096] The silicon-based resin may be selected from polysiloxane including a C2-C6 alkenyl group, polysiloxane including a C1-C10 alkyl group, hydrogen polysiloxane, and combinations thereof.

[0097] For example, the silicon-based resin may include a polysiloxane represented by Formula 1 and including an alkenyl group:

[0098] [Formula 1]

[0099]

[0100] Wherein in the formula,

[0101] m and n may each be an integer from 10 to 500, and

[0102] R1, R2 and R3 can each independently be a C1-C3 alkyl, a C2-C6 alkenyl or a combination thereof, wherein

[0103] At least one of R1, R2, and R3 may be a C2-C6 alkenyl group.

[0104] Here, m and n do not refer to a closed bond, and the sum of each structural unit refers to m and n. In Formula 1, each structural unit can be a random bond or a closed bond. For example, at least two of R1, R2, and R3 can be a C2-C6 alkenyl group.

[0105] For example, the silicon-based resin may include a polysiloxane represented by Formula 2 and including an alkyl group:

[0106] [Formula 2]

[0107]

[0108] Wherein in the formula,

[0109] a and b may each be an integer from 1 to 100, and

[0110] R4, R5, R6, R7, R8, R9, R 10 、R 11 、R 12 and R 13 can be independently a hydrogen atom, a C1-C10 alkyl group or a combination thereof, wherein

[0111] R4, R5, R6, R7, R8, R9, R 10 、R 11 、R 12 and R 13 At least one of them may be a C1-C10 alkyl group.

[0112] Here, a and b do not refer to a closed bond, and the sum of each structural unit refers to a and b. In Formula 2, each structural unit may be a random bond or a closed bond.

[0113] Based on 100 parts by weight of the polysiloxane represented by Formula 1 and including an alkenyl group, the content of the polysiloxane represented by Formula 2 and including an alkyl group can be 2 parts by weight to 10 parts by weight. For example, based on 100 parts by weight of the polysiloxane represented by Formula 1 and including an alkenyl group, the content of the polysiloxane represented by Formula 2 and including an alkyl group can be 4 parts by weight to 6 parts by weight. When the content of the polysiloxane represented by Formula 2 and including an alkyl group is less than 2 parts by weight, the unreacted polysiloxane represented by Formula 1 and including an alkenyl group can be transferred to other layers of the polyester film, such as the back or adhesive layer, thereby causing process contamination. When the content of the polysiloxane represented by Formula 2 and including an alkyl group is greater than 10 parts by weight, the unreacted polysiloxane may remain on the cured layer 10, which may cause the peel strength to increase and the peel strength to increase over time, thereby making it difficult to have stable release properties.

[0114] Here, the polysiloxane represented by Formula 1 and including an alkenyl group and the polysiloxane represented by Formula 2 and including an alkyl group may be at least one of a linear chain, a branched chain, a radial chain, and a cyclic chain.

[0115] The solid content of the silicone-based resin may be 0.1 to 9 parts by weight based on 100 parts by weight of the total content of the silicone emulsion composition. When the solid content of the silicone-based resin is less than 0.1 parts by weight, the minimum release characteristics required for peeling after lamination with the substrate 20 cannot be achieved. When the solid content of the silicone-based resin is greater than 9 parts by weight, the silicone component on the surface of the cured layer 10 may be transferred to another surface, which may cause a winding problem due to the slippage of the back surface, and the physical characteristics may be deteriorated due to the silicone component transferred to the substrate 20 after lamination with the substrate 20.

[0116] The surfactant may include a glycol-based compound, a succinate-based compound, a salt of a compound, or a combination thereof.

[0117] For example, the surfactant may include a diol-based compound represented by Formula 3:

[0118] [Formula 3]

[0119]

[0120] Wherein in the formula,

[0121] p, q, r and s can each be 0 to 20,

[0122] R1 and R4 can each independently be a hydrogen atom, a halogen atom, a cyano group, an amino group, a hydroxyl group, -C(=O), -C(=O)OR a , -C(=O)OH, substituted or unsubstituted C3-C10 alkyl, substituted or unsubstituted C2-C20 alkenyl, substituted or unsubstituted C3-C20 alkynyl, substituted or unsubstituted C3-C10 alkoxy, substituted or unsubstituted C6-C30 aryl, or a combination thereof, wherein R a is a C1-C5 alkyl group, and

[0123] R2 and R3 may each independently be a hydrogen atom, a substituted or unsubstituted C1-C5 alkyl group, or a combination thereof.

[0124] For example, the surfactant may include dioctyl 2-(sulfonatoethyl)succinate sodium salt, dioctyl 2-(phosphoethyl)succinate sodium salt, dioctyl 2-(hydroxyethyl)succinate, or a combination thereof.

[0125] Based on 100 parts by weight of the total content of the silicon emulsion composition, the content of the surfactant may be 0.01 to 0.2 parts by weight. Alternatively, based on 100 parts by weight of the polysiloxane represented by Formula 1 and including an alkenyl group, the content of the surfactant may be 0.01 to 5 parts by weight or 0.05 to 1 part by weight. When the content of the surfactant is less than 0.01 parts by weight, the content is insufficient for the surfactant and the effect of improving the coating appearance of the polyester film cannot be achieved. When the content of the surfactant is greater than 5 parts by weight, the peel strength may be increased.

[0126] The silicone emulsion composition may further include at least one of a silane coupling agent, a curing agent, and a catalyst. In order to be used as a silane coupling agent, a pressure-sensitive tackifier may be used. The silane coupling agent is not limited, but may include an alkoxy-based silane compound. Examples of alkoxy-based silane compounds may include [3-(2,3-epoxypropoxy)propyl]trimethoxysilane, etc. Without being limited thereto, all known alkoxy-based silane compounds known in the art may be used. Based on 100 parts by weight of the total content of the silicone emulsion composition, the content of the silane coupling agent may be 0.1 parts by weight to 30 parts by weight. Therefore, the time stability of the cured layer 10 of the polyester film can be ensured.

[0127] As a curing agent, polyethylene glycol tridecyl ether or the like can be used as a thermosetting curing agent. Without being limited thereto, a hardening curing agent known in the art can be used.

[0128] The catalyst may include a metal catalyst. The catalyst may use at least one metal or metalloid selected from Groups 4 to 14 of the periodic table, and for example, may include at least one selected from Rh, Pt, Sn, Ti, Pd, Ir, W, and Co. For example, the catalyst may use a platinum chelate catalyst.

[0129] The catalyst may be used to assist the addition reaction of the polysiloxane represented by Formula 1 and including an alkenyl group and the polysiloxane represented by Formula 2 and including an alkyl group. The content of the catalyst may be 1 ppm to 500 ppm, for example, 5 ppm to 500 pppm, based on the total weight of the solidified layer 10. When the content of the catalyst is less than 1 ppm, the reaction of the polysiloxane represented by Formula 1 and including an alkenyl group and the polysiloxane represented by Formula 2 and including an alkyl group may not proceed sufficiently. When the content of the catalyst is greater than 500 ppm, the peel strength may increase due to the residual catalyst remaining on the solidified layer 10.

[0130] In some cases, the solidified layer 10 may further include at least one of organic / inorganic particles, an antistatic agent, a conductivity improver, a pH adjuster, and an antifouling agent.

[0131] The organic / inorganic particles may include inorganic particles selected from the group consisting of: natural minerals; oxides, hydroxides, sulfides, nitrides or halides of elements from Groups 1 to 4, Groups 11 and 12, Groups 14 and Groups 16 to 18; carbonates, sulfates, acetates, phosphates, phosphites, carboxylates, silicates, titanates, borates and hydrates thereof; and complexes thereof.

[0132] The organic / inorganic particles may include organic particles selected from fluorine-based resins, melamine-based resins, styrene-based resins, acrylic-based resins, silicon-based resins, styrene-divinylbenzene-based copolymer resins, and polymers or copolymers cross-linked with these resins.

[0133] The shape of the organic / inorganic particles is not particularly limited and may be spherical, ball-like, rod-like or plate-like particles. Furthermore, the hardness, specific gravity, color, etc. of the organic / inorganic particles are not limited, and these organic / inorganic particles may be used alone or in combination of two or more as needed.

[0134] The average particle size D50 of the organic / inorganic particles may be 1 μm to 5 μm. For example, the average particle size D50 of the organic / inorganic particles may be 3 μm to 5 μm or 1 μm to 2 μm. When the average particle size D50 of the organic / inorganic particles is less than 1 μm, clogging cannot be prevented due to insufficient surface roughness. When the average particle size D50 of the organic / inorganic particles is greater than 5 μm, film defects may result.

[0135] For use as an antistatic agent, known antistatic agents widely used in the field of polyester films can be used, and for example, the antistatic agent can be selected from poly (3, 4-ethylenedioxythiophene) (PEDOT), poly (3, 4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS), polyaniline, polypyrrole, quaternary ammonium salt, sulfonate, phosphate, and combinations thereof. The content of the antistatic agent can be 1 to 20 parts by weight based on 100 parts by weight of the total content of the silicone emulsion composition.

[0136] For use as a conductivity improver, known conductivity improvers well known in the field of polyester films can be used, and for example, the conductivity improver can be selected from ethylene glycol, dimethyl sulfoxide, N-methyl-2-pyrrolidone, propylene glycol, butylene glycol, dipropylene glycol dimethyl ether, γ-butyrolactone, cyclopentane, dimethyl carbonate, sorbitol, and combinations thereof. The content of the conductivity improver can be 1 to 20 parts by weight based on 100 parts by weight of the total content of the silicone emulsion composition.

[0137] For use as a pH adjuster, a known pH adjuster well known in the field of polyester films can be used, and for example, the pH adjuster can be selected from sodium hydroxide, potassium hydroxide, calcium hydroxide, ammonia water, and a combination thereof. The content of the conductive improver can be 0.05 to 0.3 parts by weight based on 100 parts by weight of the total content of the silicone emulsion composition.

[0138] For use as an antifouling agent, known antifouling agents well known in the field of polyester films can be used, and for example, the antifouling agent can be selected from fluorine, fluorine-containing silane-based compounds, fluorine-containing organic compounds, self-emulsifying silicon, and combinations thereof. The content of the antifouling agent can be 0.01 to 0.3 parts by weight based on 100 parts by weight of the total content of the silicone emulsion composition.

[0139] The silicone emulsion composition can be 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 coating the substrate 10 at least once using a known method (such as a rod coating method, a reverse roll coating method, a gravure roll coating method, etc.). When the solid content of the silicone emulsion composition is less than 0.5 wt %, uniform coating is difficult and the peel strength may increase. When the solid content of the silicone emulsion composition is greater than 15 wt %, the coating appearance may be poor and the adhesion between the cured layer 10 and the substrate 20 may be reduced.

[0140] The silicone emulsion composition may further include an organic solvent in an amount of 0.01 to 10 wt % (e.g., 0.01 to 5 wt %) based on the total weight of the silicone emulsion composition to improve applicability or transparency. When the organic solvent content is greater than 10 wt %, there is a risk of explosion during the drying, stretching, and heat treatment processes when using an inline coating method.

[0141] For use as an organic solvent, any material capable of dispersing and applying the solids of the silicone emulsion composition may be used, but is not limited thereto, and for example, the organic solvent may be: a hydrocarbon-based aromatic solvent such as toluene, xylene, etc.; a hydrocarbon-based aliphatic solvent such as hexane, heptane, octane, isooctane, decane, cyclohexane, methylcyclohexane, isoparaffin, etc.; a hydrocarbon-based solvent such as industrial gasoline (rubber gasoline, etc.), petroleum benzene, solvent naphtha, etc.; a ketone-based solvent such as acetone, methyl ethyl ketone, 2-pentanone, 3-pentanone, 2-hexanone, 2-heptanone, 4-heptanone, methyl isobutyl ketone, diisobutyl ketone, acetonyl acetone, cyclohexanone, etc.; an ester-based solvent such as ethyl acetate, propyl acetate, isopropyl acetate, etc. Ester, butyl acetate, isobutyl acetate, etc.; ether-based solvents such as diethyl ether, dipropyl ether, diisopropyl ether, dibutyl ether, 1,2-dimethoxyethane, 1,4-dioxane, etc.; solvents having an ester portion and an ether portion such as 2-methoxyethyl acetate, 2-ethoxyethyl acetate, propylene glycol monomethyl ether acetate, 2-butoxyethyl acetate, etc.; siloxane-based solvents such as hexamethyldisiloxane, octamethyltrisiloxane, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, tris(trimethylsiloxy)methylsilane, tetrakis(trimethylsiloxy)silane, etc.; fluorine-based solvents such as trifluorotoluene, hexafluoroxylene, methyl nonafluorobutyl ether, ethyl nonafluorobutyl ether, etc.; or mixed solvents thereof. For example, the solvent for the silicone emulsion composition may include isopropyl alcohol, butyl cellosolve, acetone, methanol, ethanol, etc.

[0142] The surface energy of the cured layer 10 may be 15 to 20 dynes / cm. When the surface energy of the cured layer 10 is within the above range, the polyester film has low peel strength and improved residual adhesion with minimal pinhole occurrence and excellent adhesive wettability.

[0143] The thickness of the solidified layer 10 may be 0.01 μm to 10 μm. When the thickness of the solidified layer 10 is less than 0.01 μm, the solidified layer 10 may not be uniformly formed. When the thickness of the solidified layer 10 is greater than 10 μm, obstruction may occur between one side and the back side of the substrate 20.

[0144] [Polyester film]

[0145] The polyester film according to an embodiment may be a release film.

[0146] The polyester film according to the embodiment may have a peel strength of 20 gf / cm or less and a residual adhesion rate of 90% or more at room temperature.

[0147] The polyester film according to the embodiment may have minimal pinhole defects.

[0148] [Components]

[0149] The component according to another embodiment may include a polyester film. Examples of the component may include, but are not limited to, tapes for mobile devices, foam tapes, windows, and the like.

[0150] In the present specification, the substituents (substituents) used in the above formulae can be defined as follows.

[0151] As described in conjunction with the above formula, the “substituted” in which an alkyl, alkoxy, alkenyl, alkynyl or aryl group is “substituted” refers to substitution with a halogen atom, a C1-C10 alkyl group substituted with a halogen atom (e.g., CCF3, CHCF2, CH2F, CCl3, etc.), a hydroxyl group, a nitro group, a cyano group, an amino group, an amidine group, a hydrazine group, a hydrazone group, a carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, 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.

[0152] Detailed examples of the C1-C10 alkyl group used in the above formula may include methyl, ethyl, propyl, isobutyl, sec-butyl, tert-butyl, neobutyl, isopentyl, hexyl, and the like, and at least one hydrogen atom in the alkyl group may be substituted with a substituent as defined in conjunction with “substituted”.

[0153] Detailed examples of the C1-C10 alkoxy group used in the above formula may include a methoxy group, an ethoxy group, a propoxy group, and the like, and at least one hydrogen atom in the alkoxy group may be substituted with a substituent as defined in conjunction with “substituted”.

[0154] Detailed examples of the C2-C10 alkenyl group used in the above formula may include vinylene, allylene, and the like, and at least one hydrogen atom in the alkenyl group may be substituted with a substituent as defined in conjunction with “substituted”.

[0155] Detailed examples of the C2-C10 alkynyl group used in the above formula may include acetylene and the like, and at least one hydrogen atom in the alkynyl group may be substituted with a substituent as defined in connection with “substituted”.

[0156] The C6-C20 aryl group used in the above formula may be used alone or in combination to mean an aromatic system including one or more rings, and examples thereof may include phenyl, naphthyl, tetrahydronaphthyl, etc. In addition, at least one hydrogen atom in the aryl group may be substituted with a substituent as defined in conjunction with “substituted”.

[0157] Hereinafter, the composition of the present disclosure and its effects will be described in more detail through examples and comparative examples. However, it will be apparent that the examples described herein are intended to explain the present disclosure more specifically, and the scope of the present disclosure is not limited to these examples.

[0158] [Example]

[0159] Example 1: Polyester film

[0160] To serve as a substrate, a corona-treated 50 μm thick polyethylene terephthalate (PET) film (Excell-50 μm, Toray advanced materials) was prepared.

[0161] Separately, a silicone emulsion composition was prepared by mixing 100 parts by weight of particles of a polysiloxane represented by Formula 1-1 and including an alkenyl group (Wacker, Dow Corning, D(50): about 200 nm, Mw: about 5,000 Dalton), 5 parts by weight of particles of a polysiloxane represented by Formula 2-1 and including an alkyl group (Wacker, Dow Corning, D(50): about 200 nm, Mw: about 5,000 Dalton), 0.8 parts by weight of a glycol-based compound surfactant represented by Formula 3-1, and the remainder of water. The silicone emulsion composition thus prepared was applied to a polyethylene terephthalate substrate film using a bar coater and dried with hot air at a temperature of 180° C. for 50 seconds to form a cured layer, thereby manufacturing a polyester film.

[0162] [Formula 1-1]

[0163]

[0164] Wherein in the formula,

[0165] m and n are each 60, and

[0166] R1, R2 and R3 are each a vinyl group.

[0167] [Formula 2-1]

[0168]

[0169] Wherein in the formula,

[0170] a and b are each 50, and

[0171] R4, R5, R7, R8, R9, R 10 、R 11 、R 12 and R 13 is a methyl group, and R6 is a hydrogen atom.

[0172] [Formula 3-1]

[0173]

[0174] Wherein in the formula,

[0175] p, q, r, and s are each 0, and

[0176] R1, R2, R3 and R4 are each independently a hydrogen atom.

[0177] Example 2: Polyester film

[0178] In preparing the silicone emulsion composition, a polyester film was manufactured in the same manner as in Example 1 except that 0.8 parts by weight of dioctyl 2-(sulfonatoethyl)succinate sodium salt surfactant was used instead of the diol-based compound surfactant represented by Formula 3-1.

[0179] Example 3: Polyester film

[0180] In preparing the silicone emulsion composition, a polyester film was manufactured in the same manner as in Example 1 except that 0.8 parts by weight of dioctyl 2-(phosphoethyl)succinate sodium salt surfactant was used instead of the diol-based compound surfactant represented by Formula 3-1.

[0181] Example 4: Polyester film

[0182] In preparing the silicone emulsion composition, a polyester film was manufactured in the same manner as in Example 1 except that 0.8 parts by weight of dioctyl 2-(hydroxyethyl)succinate surfactant was used instead of the diol-based compound surfactant represented by Formula 3-1.

[0183] Example 5: Polyester film

[0184] In preparing the silicone emulsion composition, a polyester film was manufactured in the same manner as in Example 1, except that 0.03 parts by weight of the diol-based compound surfactant represented by Formula 3-1 was used instead of 0.8 parts by weight.

[0185] Example 6: Polyester film

[0186] In preparing the silicone emulsion composition, a polyester film was manufactured in the same manner as in Example 1, except that 3.0 parts by weight of the diol-based compound surfactant represented by Formula 3-1 was used instead of 0.8 parts by weight.

[0187] Comparative Example 1: Polyester film

[0188] In preparing the silicone emulsion composition, a polyester film was manufactured in the same manner as in Example 1, except that 100 parts by weight of particles of a polysiloxane represented by Formula 1-1 and including an alkenyl group (Wacker, Dow Corning Corporation, D(50): about 400 nm, Mw: about 5,000 Dalton) and 5 parts by weight of particles of a polysiloxane represented by Formula 2-1 and including an alkyl group (Wacker, Dow Corning Corporation, D(50): about 400 nm, Mw: about 5,000 Dalton) were used.

[0189] Comparative Example 2: Polyester film

[0190] In preparing the silicone emulsion composition, a polyester film was manufactured in the same manner as in Example 1, except that 100 parts by weight of particles of a polysiloxane represented by Formula 1-1 and including an alkenyl group (Wacker, Dow Corning Corporation, D(50): about 700 nm, Mw: about 10,000 Daltons, m and n in Formula 1-1 are 120) and 5 parts by weight of particles of a polysiloxane represented by Formula 2-1 and including an alkyl group (Wacker, Dow Corning Corporation, D(50): about 700 nm, Mw: about 10,000 Daltons, a and b in Formula 2-1 are 100) were used.

[0191] Comparative Example 3: Polyester film

[0192] In preparing the silicone emulsion composition, a polyester film was manufactured in the same manner as in Example 1, except that 100 parts by weight of particles of a polysiloxane represented by Formula 1-1 and including an alkenyl group (Wacker, Dow Corning Corporation, D(50): about 100 nm, Mw: about 2,500 Daltons, m and n in Formula 1-1 are 30) and 5 parts by weight of particles of a polysiloxane represented by Formula 2-1 and including an alkyl group (Wacker, Dow Corning Corporation, D(50): about 100 nm, Mw: about 2,500 Daltons, a and b in Formula 2-1 are 25) were used.

[0193] Evaluation Example 1: Evaluation of Physical Properties

[0194] Physical properties of the polyester films prepared 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.

[0195] (1) Measurement of peel strength (gf / in)

[0196] Each polyester film was attached to a cold-rolled stainless steel plate with a cured layer on top using double-sided tape. TESA7475 acrylic tape was attached to the cured layer, pressed with a 2 kg roller, and left at room temperature for 7 days before the peel strength was measured. The peel strength was measured five times using the following measuring device and method, and the average of the measured values ​​was used as the peel strength.

[0197] Measuring device: AR-1000 (chemical instrument)

[0198] Measurement method: peeling angle 180°, peeling rate 0.3m / min

[0199] (2) Residual adhesion rate (%)

[0200] Each polyester film was cut into a size of 50 mm x 250 mm to prepare a sample. The sample thus prepared was stored under conditions of 25°C and 65% RH for 24 hours. TESA7475 acrylic-based tape was attached to the surface of the cured layer and was applied at room temperature at 20 g / cm 2 The adhesive tape was pressed under a load of 1000 nm for 24 hours. Then, the TESA7475 acrylic-based adhesive tape attached to the surface of the cured layer was collected without contamination. The collected TESA7475 acrylic-based adhesive tape was adhered to the flat and clean surface of the PET substrate film and pressed back and forth once with a 2 kg roller (ASTM D-1000-55T). The TESA7475 acrylic-based adhesive tape was then peeled off from the PET substrate film and the peel strength was measured by using the following measuring device and measuring method.

[0201] Separately, an unused TESA7475 acrylic-based tape was attached to a flat and clean surface of a PET substrate film and pressed back and forth once with a 2 kg roller (ASTM D-1000-55T), and the peel strength was measured using the following measuring device and measuring method. Each peel strength was substituted into Equation 1 to obtain the residual adhesion rate (%).

[0202] Measuring device: AR-1000 (chemical instrument)

[0203] Measurement method: peeling angle 180°, peeling rate 0.3m / min

[0204] [Equation 1]

[0205] Residual adhesion rate (%) = [(peel strength of acrylic-based tape peeled from cured layer) / (peel strength of unused acrylic-based tape) x 100]

[0206] (3) Surface energy (dynes / cm)

[0207] The surface tension and liquid penetration depth of the cured layer of each polyester film in water and diiodomethane were measured. These measured values ​​were then substituted into Equation 2 to calculate the surface energy by using the Owens-Wendt model.

[0208] [Equation 2]

[0209] E s =σ1xln(kxh)

[0210] Wherein in the formula,

[0211] E s Expresses surface energy (J / m 2 ), σ1 represents the surface tension of the liquid (N / m), k represents the (dimensionless) wetting coefficient, and h represents the wetting depth of the liquid (m).

[0212] (4) Number of pinholes (adhesive wettability)

[0213] Each polyester film was cut into a size of 10 mm x 10 mm to prepare a sample. An acrylic-based adhesive was applied to the surface of the cured layer of the prepared sample to a thickness of about 10 μm, and the number of pinholes per unit area on the coated surface was then observed with the naked eye.

[0214] Table 1

[0215]

[0216] Referring to Table 1, the polyester films produced in Examples 1 to 6 exhibited minimal pinhole defects, excellent adhesive wettability, peel strengths of 20 gf / cm or less, and residual adhesion rates of 93% or greater. In contrast, the polyester film produced in Comparative Example 1, due to the larger average particle size D50 of the silicone-based resin, experienced compatibility issues with the polar solvent of the acrylic-based adhesive solution, leading to a rapid increase in pinholes. The polyester films produced in Comparative Examples 2 and 3, due to the silicone-based resin having an excessively low or high weight-average molecular weight (Mw), exhibited increased peel strength and experienced compatibility issues with the acrylic-based adhesive solution, leading to a rapid increase in pinholes.

Claims

1. A polyester film comprising: polyester backing; and a solidified layer of a silicone emulsion composition, the solidified layer being located on at least one side of the polyester substrate, wherein the silicone emulsion composition comprises at least two silicone-based resins and a surfactant, At least one of the silicon-based resins has a weight average molecular weight of 3,000 to 7,000 Daltons, and The surface energy of the solidified layer is 15 dyne / cm to 20 dyne / cm. 2 . The polyester film according to claim 1 , wherein the silicon-based resin comprises first particles and second particles, and an average particle diameter D50 of the first particles and the second particles is 0.1 nm to 300 nm. 3 . The polyester film according to claim 1 , wherein the silicon-based resin is selected from the group consisting of polysiloxanes including C2-C6 alkenyl groups, polysiloxanes including C1-C10 alkyl groups, hydrogen polysiloxanes, and combinations thereof.

4. The polyester film according to claim 1, wherein the silicon-based resin comprises a polysiloxane represented by Formula 1 and including an alkenyl group: [Formula 1] Wherein in the formula, m and n are each an integer from 10 to 500, and R1, R2 and R3 are each independently C1-C3 alkyl, C2-C6 alkenyl or a combination thereof, wherein At least one of R1, R2 and R3 is a C2-C6 alkenyl group.

5. The polyester film according to claim 1, wherein the silicon-based resin comprises a polysiloxane represented by Formula 2 and including an alkyl group: [Formula 2] Wherein in the formula, a and b are each an integer from 1 to 100, and R4, R5, R6, R7, R8, R9, R 10 、R 11 、R 12 and R 13 are each independently a hydrogen atom, a C1-C10 alkyl group or a combination thereof, wherein R4, R5, R6, R7, R8, R9, R 10 、R 11 、R 12 and R 13 At least one of them is a C1-C10 alkyl group. The polyester film according to claim 1 , wherein a solid content of the silicon-based resin is 0.1 to 9 parts by weight based on 100 parts by weight of the total content of the silicon emulsion composition. 7 . The polyester film according to claim 1 , wherein the surfactant comprises a glycol-based compound, a succinate-based compound, a salt thereof, or a combination thereof.

8. The polyester film according to claim 1, wherein the surfactant comprises a diol-based compound represented by Formula 3: [Formula 3] Wherein in the formula, p, q, r and s are each 0 to 20, R1 and R4 are each independently a hydrogen atom, a halogen atom, a cyano group, an amino group, a hydroxyl group, -C(=O), -C(=O)OR a , -C(=O)OH, substituted or unsubstituted C3-C10 alkyl, substituted or unsubstituted C2-C20 alkenyl, substituted or unsubstituted C3-C20 alkynyl, substituted or unsubstituted C3-C10 alkoxy, substituted or unsubstituted C6-C30 aryl, or a combination thereof, wherein R a is a C1-C5 alkyl group, and R2 and R3 are each independently a hydrogen atom, a substituted or unsubstituted C1-C5 alkyl group, or a combination thereof. 9 . The polyester film of claim 1 , wherein the surfactant comprises dioctyl 2-(sulfonatoethyl)succinate sodium salt, dioctyl 2-(phosphoethyl)succinate sodium salt, dioctyl 2-(hydroxyethyl)succinate, or a combination thereof. 10 . The polyester film according to claim 1 , wherein the surfactant is included in an amount of 0.01 to 0.2 parts by weight based on 100 parts by weight of the total content of the silicone emulsion composition. 11 . The polyester film according to claim 1 , wherein the silicone emulsion composition further comprises at least one of a silane coupling agent, a curing agent, and a catalyst. 12 . The polyester film according to claim 11 , wherein the silane coupling agent comprises an alkoxy-based silane compound.

13. The polyester film of claim 11, wherein the catalyst comprises a metal catalyst. The polyester film according to claim 1 , wherein the cured layer has a thickness of 0.01 μm to 10 μm.

15. The polyester film of claim 1, wherein the substrate is a biaxially oriented polyester film. The polyester film according to claim 1 , wherein the substrate has a thickness of 10 μm to 300 μm. The polyester film according to claim 1 , wherein the film is a release film.

18. A component comprising the polyester film according to any one of claims 1 to 17.

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