Release Film

Abstract

The present disclosure relates to a release film. The release film according to one aspect of the present disclosure can achieve a wide range of peeling forces and exhibit excellent stability over time.

Description

[Technical Field]

[0001] The present disclosure relates to release films. [Background technology]

[0002] A release film is usually coated with an adhesive and used as a protective film to protect the adhesive component from foreign matter in the atmosphere or unwanted adherends, and generally has a structure in which a release layer is provided on a polyester base film.

[0003] Release films are generally attached to adhesive films or tapes as protective films, preventing adhesion to unintended substrates and preventing contamination by dust and other foreign matter before the adhesive is applied. Other uses include preventing adhesion between molds and molded objects during heat and pressure molding processes, such as printed wiring boards and in-mold molding. They can also be used as intermediate materials for coating various resin materials, such as ceramic slurries, on the release surface of the release film. They can also be used as interleaving sheets to protect various resin layers coated on other substrates. In particular, release films are used as carrier films for thinly and uniformly applying ceramic slurries to green sheets that make up multi-layer ceramic capacitors (MLCCs). MLCCs are a type of capacitor used to store electricity and stabilize current. Due to their small size and large capacitance, they are widely used in portable electronic devices. Demand for them has increased significantly, particularly with the recent popularity of smartphones and tablet PCs. Such MLCCs are completed by alternately stacking tens or hundreds of layers of green sheets and internal metal electrodes, and then connecting external electrodes, and their sizes vary from less than 1 mm to several nm.

[0004] The green sheets used in MLCCs are formed by uniformly applying ceramic slurry to a carrier film support and then firing it. The carrier film used to form the green sheets is made from a biaxially oriented polyester film base, which has excellent mechanical strength, dimensional stability, heat resistance, and price competitiveness, and one side of which is covered with a release film coated with a polymer silicone release layer.

[0005] Recently, the trend toward smaller MLCCs and higher capacity has led to the need for thinner green sheets and more multi-layered ceramic slurries. However, if the peel strength of a release film used in MLCC manufacturing is too low, the ceramic slurry may peel off the release film first. Conversely, if the peel strength of a release film is too high, cracks or breaks may occur in the green sheet when the release film is removed from the ceramic green sheet. Therefore, the release film used in MLCCs must have physical properties that allow it to be peeled off with an appropriate peel force.

[0006] Furthermore, if the organic solvent used in producing the ceramic slurry does not volatilize sufficiently and remains on the release layer, orange peel-like stains will appear on the surface of the green sheet. This problem, in addition to being caused by roughness, occurs when the release layer has low solvent resistance and the ceramic slurry solvent remains in the release layer, and this problem required improvement. Preventing defects in the green sheet such as those mentioned above will lead to improved reliability of MLCCs, so the function of the release film can be said to be extremely important in MLCC production. Summary of the Invention [Problem to be solved by the invention]

[0007] The present disclosure provides a technology for a release film. The present disclosure aims to provide a release film that can achieve a wide range of peel forces and exhibit excellent stability over time.

[0008] The present disclosure aims to provide a release film that can be formed by low-temperature curing using a water-based system. [Means for solving the problem]

[0009] In one aspect, the present disclosure can provide a release film.

[0010] In one aspect, the release film includes a substrate film; and a release layer formed by applying a release coating composition to at least one surface of the substrate film; and in a depth profile measured using a time-of-flight secondary ion mass spectrometer (TOF-SIMS) from the surface of the release layer in a thickness direction, - NH in the ionic strength curve - The maximum count number of ions and NH - Ion count, NH at the boundary between the release layer and the base film - The number of ion counts is I NH_max , I NH_t , I NH_b When I NH_t / I NH_max The ratio is 0.9 0 Below, I NH_t >I NH_b It could be.

[0011] In one aspect, the NH - The ionic strength curve of may include an inflection point.

[0012] In one aspect, the NH - The ionic strength curve of may have a concave shape.

[0013] In one aspect, the release layer is Si - , S - , C7H5O2 - , and C3H5N5 - The compound may further comprise one or more of the ions.

[0014] In one aspect, the release layer is Si - ions and C7H5O2- ions, and in a depth profile measured by TOF-SIMS in a thickness direction from the surface of the release layer, - The ionic strength of C7H5O2 - The ionic strength of the Si in the release layer increases. - Ions and C7H5O2 - It may include points where the ionic strength of the ions is the same.

[0015] In one aspect, the release layer comprises S - ions, and in a depth profile measured by TOF-SIMS in a thickness direction from the surface of the release layer, S - The ionic strength curve of may include an inflection point.

[0016] In one aspect, the S - The ionic strength curve of may have a concave shape.

[0017] In one aspect, the release layer is - ions, and in a depth profile measured by TOF-SIMS in a thickness direction from the surface of the release layer, C3H5N5 - The ionic strength of the solution may be reduced.

[0018] In one aspect, the release film can exhibit a tape instant peel force of 5 to 32 gf / in.

[0019] In one aspect, the release film can exhibit a tape peel strength at room temperature after one day of 3 to 1000 gf / in.

[0020] In one aspect, the release film can exhibit a green sheet peel force of 1 to 3 gf / in.

[0021] In one aspect, the silicone content of the release layer, as measured using an X-ray fluorescence analyzer (XRF), is 0.001 to 0.2 g / m 2 It could be.

[0022] In one aspect, the surface energy of the release layer may be 19 to 30 dyne / cm.

[0023] In one aspect, the release film can be formed by curing the release coating composition at a temperature of 150° C. or less.

[0024] In one aspect, the release coating composition may be an aqueous release coating composition that includes: a silicone emulsion component (A) containing polydimethylsiloxane (PDMS) as a composition curable at a temperature of 150°C or less; a component (B) containing two or more functional groups in one molecule that can undergo a condensation reaction with the silicone emulsion component; and an acid catalyst. [Effects of the Invention]

[0025] The release film according to one aspect of the present disclosure can achieve a wide range of release forces during production into a release film and can exhibit excellent stability over time, and these effects are even better than those of release films produced using a silicone-based release coating composition.

[0026] Although the release film according to one aspect of the present disclosure is a silicone-based film, it can be formed by low-temperature curing using a water-based system, which is superior to conventional silicone-based films formed by high-temperature curing. [Brief explanation of the drawings]

[0027] [Figure 1] 1 shows the results of TOF-SIMS depth profile measurement of a release film according to an embodiment of the present invention.

[0028] [Figure 2] 1 is a schematic diagram showing a conventional silicone-based release film and a release film according to an embodiment of the present invention.

[0029] [Figure 3]1 is a graph showing the FT-IR spectrum measurement results of a release film according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0030] The various aspects or examples described in this document are provided for the purpose of clearly explaining the technical idea of ​​the present disclosure and are not intended to limit the technical idea to specific embodiments. The technical idea of ​​the present disclosure includes various modifications, equivalents, and alternatives of each aspect or example described in this document, as well as aspects or examples that are selectively combined in whole or in part. Furthermore, the scope of the technical idea of ​​the present disclosure is not limited to the various aspects or examples presented below and the specific description thereof.

[0031] Unless otherwise defined, terms used in this document, including technical and scientific terms, may have the meaning commonly understood by one of ordinary skill in the art to which this disclosure belongs.

[0032] 1.Release film

[0033] In one aspect of the present disclosure, a release film can include a substrate film; and a release layer formed by applying a release coating composition to at least one surface of the substrate film.

[0034] In one aspect, the release film is characterized in that, in a depth profile measured from the surface of the release layer in a thickness direction using a time-of-flight secondary ion mass spectrometer (TOF-SIMS), NH - NH in the ionic strength curve - The maximum count number of ions and NH - Ion count, NH at the boundary between the release layer and the base film - The number of ion counts is I NH_max , I NH_t , I NH_b When I NH_t / I NH_maxThe ratio is 0.9 0 Below, I NH_t >I NH_b It could be.

[0035] FIG. 1 shows the results of TOF-SIMS depth profile measurement of a release film according to one embodiment of the present invention.

[0036] Referring to Figure 1, I NH_t / I NH_max The ratio is 0.9 0 Below, I NH_t >I NH_b For example, I NH_t / I NH_max The ratio is 0.8 0 may be less than or equal to 0.7 0 may be less than or equal to 0.6 0 Can be less than or equal to 0.5 0 may be less than or equal to 0.4 0 may be less than or equal to 0.3 0 may be less than or equal to 0.2 0 Can be less than or equal to 0.1 0 It may be equal to or less than 0.05, or it may be equal to or greater than 0.07, or it may be equal to or greater than 0.09.

[0037] For example, I NH_t / I NH_max The ratio is 0.9 0 If the ratio is less than 1, a large amount of non-silicone components (e.g., melamine components) may be present as the main component on the surface of the release layer. NH_t / I NH_max The ratio is 0.5 0 If the thickness is less than 100 μm, non-silicone components (e.g., melamine components), surfactants, and other components (e.g., components that do not undergo sufficient phase separation from the melamine components) may be present on the surface of the release layer. NH_t / I NH_max The ratio is 0.1 0 If it is below this value, the surface of the release layer may contain a small amount of non-silicone components (for example, melamine components) and a large amount of other components (for example, components that undergo sufficient phase separation from the melamine component).

[0038] Referring to FIG. - The ionic strength curve of contains an inflection point, where the inflection point is NH - It means the point where the slope of the tangent line changes when the ionic strength of increases or decreases. NH_t and I NH_max Between the points that correspond to NH - The inflection point where the rate of increase in ionic strength decreases, and the I NH_max and I NH_b Between the points that correspond to NH - There may be one or more inflection points at which the degree of decrease in ionic strength of decreases.

[0039] For example, I in the ionic strength curve NH_t and I NH_max Between the points that correspond to NH - The inflection point at which the rate of increase in the ionic strength decreases may be the point at which the Si content in the release layer begins to decrease.

[0040] Referring to FIG. - The ionic strength curve of may have a concave shape.

[0041] NH - The concave shape of the ionic strength curve means that the distribution of the silicone component from the entire surface of the release film to the base film has a concave shape. In other words, it can mean that the proportion of the silicone component is high on the entire surface of the release film, the content of the silicone component is reduced in the middle part of the release film, and a non-silicone component (e.g., melamine component) is contained as the main component, and the base film is present underneath. In one aspect, the release layer is made of Si - , S - , C7H5O2 - , and C3H5N5 - The compound may further comprise one or more of the ions.

[0042] For example, the release layer is Si - , S -, C7H5O2 - , and C3H5N5 - The release layer may contain any combination of two or more of the ions. For example, the release layer may contain Si - , S - , C7H5O2 - , and C3H5N5 - It may contain ions.

[0043] Referring to FIG. 1, the release layer is made of Si - ions and C7H5O2 - ions, and in a depth profile measured by TOF-SIMS in a thickness direction from the surface of the release layer, - The ionic strength of C7H5O2 - The ionic strength of the Si in the release layer increases. - Ions and C7H5O2 - It may include points where the ionic strength of the ions is the same.

[0044] For example, the Si - Ions and C7H5O2 - The point at which the ionic strength of the ions is the same may be the point at which the region begins where non-silicone components (eg, melamine components) begin to be included significantly compared to silicone components.

[0045] For example, the Si - Ions and C7H5O2 - The point where the ionic strength of the ions is the same is I NH_b From the point corresponding to I NH_t It is also closer to the point where I NH_t From the point corresponding to I NH_max It may be closer to the point where

[0046] For example, the Si - Ions and C7H5O2 - The point where the ionic strength of the ions is the same may be the point where the non-silicone component region begins in a release film having a silicone component region-a non-silicone component (e.g., melamine component) region-substrate film structure. Such a point is INH_b From the point corresponding to I NH_t It is also closer to the point where I NH_t From the point corresponding to I NH_max This may be due to the manufacturing process in which the release coating composition containing the silicone component and the non-silicone component is coated once to form the release layer.

[0047] Referring to FIG. 1, the release layer is S - ions, and in a depth profile measured by TOF-SIMS in a thickness direction from the surface of the release layer, S - The ionic strength curve of may include an inflection point. NH_t and I NH_max Between the points corresponding to S - There is an inflection point where the rate of increase in ionic strength decreases, and the I NH_max and I NH_b Between the points corresponding to S - There may be an inflection point at which the degree of decrease in ionic strength decreases.

[0048] Referring to FIG. - The ionic strength curve of may have a concave shape.

[0049] Referring to FIG. 1, the release layer is made of C3H5N5 - ions, and in a depth profile measured by TOF-SIMS in a thickness direction from the surface of the release layer, C3H5N5 - The ionic strength of the solution may be reduced.

[0050] In one aspect of the present disclosure, a release film may be manufactured by applying a release coating composition to at least one surface of a substrate film to form a release layer, and the release film manufactured in this manner may have the following physical properties. The following physical properties may be measured by the methods described in the experimental examples.

[0051] In one aspect, the release film may exhibit a tape instant peel force of 5 to 32 gf / in, and may exhibit a peel force of a value between the upper and lower limits described above, for example, 7 gf / in or more, 9 gf / in or more, 11 gf / in or more, 13 gf / in or more, 15 gf / in or more, 17 gf / in or more, 19 gf / in or more, 21 gf / in or more, 23 gf / in or more, 25 gf / in or more. / in or more, 27 gf / in or more, 29 gf / in or more, or 31 gf / in or more, or 31 gf / in or less, 29 gf / in or less, 27 gf / in or less, 25 gf / in or less, 23 gf / in or less, 21 gf / in or less, 19 gf / in or less, 17 gf / in or less, 15 gf / in or less, 13 gf / in or less, 11 gf / in or less, 9 gf / in or less, or 7 gf / in or less.

[0052] In one aspect, the release film may exhibit a tape room temperature one-day peel strength of 3 to 1000 gf / in, and may exhibit a peel strength of a value between the upper and lower limits described above, for example, 10 gf / in or more, 50 gf / in or more, 100 gf / in or more, 200 gf / in or more, 300 gf / in or more, 400 gf / in or more, 500 gf / in or more, 600 gf / in or more. In, the release strength may be 700 gf / in or more, 800 gf / in or more, or 900 gf / in or more, or 900 gf / in or less, 800 gf / in or less, 700 gf / in or less, 600 gf / in or less, 500 gf / in or less, 400 gf / in or less, 300 gf / in or less, 200 gf / in or less, 100 gf / in or less, 50 gf / in or less, or 20 gf / in or less. Such a release film satisfies the release strength of a light release, heavy release, or ultra-heavy release film and can be used in a variety of fields requiring such a release strength. In one aspect, the release film exhibits a wide range of tape room temperature 1-day release strength, and this range corresponds to a physical property that cannot be achieved with conventional silicone release films.

[0053] In one aspect, the release film may exhibit a green sheet peel strength of 1 to 3 gf / in, or may exhibit a peel strength between the upper and lower limits described above. The green sheet peel strength may be measured by the method described in Experimental Example 1, and may indicate the peel strength for a 3 μm thick green sheet.

[0054] Therefore, the release film according to one aspect of the present disclosure has the advantage of being able to achieve a variety of tape room temperature one-day peel strength levels (grades) while at the same time achieving a certain range of light peel strength based on the tape immediate peel strength or green sheet peel strength. As a result, one release film can be used in various industrial fields that require high tape room temperature one-day peel strength for various purposes, and can also be used in industrial fields that require light peel strength based on the tape immediate peel strength or green sheet peel strength, and can be used for a variety of purposes.

[0055] In one aspect, the release film has a silicone content of about 0.001 to about 0.2 g / m2 as measured using an X-ray fluorescence analyzer. 2 It could be.

[0056] In one aspect, the release film may exhibit a residual adhesion rate of about 94%, about 95%, or about 96% or more, and the residual adhesion rate may be measured by the method described in Experimental Example 4. Generally, in the process of peeling off a release film, an adhesive such as a pressure-sensitive adhesive (PSA) or an optically clear adhesive (OCA) is applied to the release film, and then the release film is peeled off. However, during this peeling process, uncured components present on the release layer of the release film may transfer, which can cause problems with the adhesive properties of the adhesive. The release film of the present disclosure has a residual adhesion rate of about 95% or more, making it advantageous for use in fields requiring high standards.

[0057] In one aspect, the release film may have a surface energy of about 19 to about 30 dyne / cm or about 19.5 to about 27 dyne / cm, and may exhibit a surface energy value between the upper and lower limits described above. The surface energy of the release layer may be measured by the method described in Experimental Example 5.

[0058] In one aspect, the release film may have a residual amount of volatile organic compounds of about 5 ppm or less, which allows it to be used as an environmentally friendly material.

[0059] 2.Release film manufacturing method

[0060] In one aspect of the present disclosure, the method for producing a release film is not particularly limited as long as it forms a release layer using a release coating composition. For example, the release coating composition is applied to at least one surface of a substrate film, and then heated and dried to cure component (B) and the silicone emulsion component contained in the release coating composition, thereby forming a release layer, and thus a release film can be obtained.

[0061] In one aspect, the method for applying the release coating composition may be a known method widely used in the field of release films, such as, but not limited to, gravure coating, bar coating, spray coating, spin coating, knife coating, roll coating, die coating, in-line coating, and off-line coating.

[0062] In one aspect, the applied release coating composition can be thermally cured by heating and drying, and the heating temperature can be 110°C to 160°C, 120°C to 160°C, 130°C to 160°C, 140°C to 160°C, 150°C to 160°C, 145°C to 155°C, or 150°C to 155°C, and can be within the ranges described above. In one aspect, the heating time can be 5 seconds to 60 seconds, 10 seconds to 40 seconds, 15 seconds to 30 seconds, or 20 seconds to 25 seconds, and can be within the ranges described above.

[0063] In one aspect, a post-curing process may be included to cure any uncured components after the heat-drying of the release coating composition. For example, the post-curing process may involve rolling the release film produced by heat-drying into a roll and then treating it at 40°C to 60°C for 1 to 5 days. The treatment temperature may be 40°C to 60°C, 45°C to 55°C, 47°C to 53°C, 49°C to 53°C, 50°C to 53°C, or 50°C to 51°C, and the treatment time may be 1 to 5 days, 1.5 to 4.5 days, 2 to 4 days, 2.5 to 3.5 days, or 3 to 3.5 days. Performing a post-curing process may improve the stability over time of the physical properties (e.g., peel strength, residual adhesion, or rub-off characteristics) of the release film.

[0064] In one aspect, the release layer of the release film can be formed to a dry thickness of 0.01 to 2 μm, or 50 nm to 500 nm.

[0065] In one aspect, the release film may be used in pressure-sensitive adhesives, semi-curable adhesives, protective films, coating substrates, interleaf liner, ceramic sheets for multilayer ceramic capacitors, semi-curable resins for printed circuits, or prepregs. The present disclosure will be further clarified through the above-mentioned aspects and the following experimental examples and examples. Hereinafter, the present disclosure will be described in detail through examples described with reference to the accompanying tables so that those skilled in the art can easily understand and implement the present disclosure. However, these experimental examples and examples are intended to exemplify the present disclosure, and the scope of the present disclosure is not limited to these experimental examples and examples.

[0066] 3. Base film

[0067] In one aspect of the present disclosure, the base film constituting the release film can be any known film that has been widely used in the field of release films, and is not limited thereto.

[0068] In one aspect, the substrate film may be formed from a polyester-based polymer, but the substrate film to which the release coating composition is applied is not limited to a polyester-based film. Specifically, the polyester-based polymer may be, but is not limited to, a polyethylene terephthalate polymer, a polybutylene terephthalate polymer, a polyethylene naphthalate polymer, a polyphenylene sulfide polymer, a polyether ether ketone polymer, a polyphthalamide polymer, a polyimide polymer, a polysulfone polymer, a polyethersulfone polymer, a polyetherimide polymer, or a combination thereof.

[0069] In one aspect, the polyester polymer may be a polyester obtained by the condensation reaction of an aromatic dicarboxylic acid and an aliphatic glycol. In one aspect, the aromatic dicarboxylic acid may be, but is not limited to, isophthalic acid, phthalic acid, terephthalic acid, 2,6-naphthalenedicarboxylic acid, adipic acid, sebacic acid, an oxycarboxylic acid (e.g., p-oxybenzoic acid), or a combination thereof. In one aspect, the aliphatic glycol may be, but is not limited to, ethylene glycol, diethylene glycol, propylene glycol, butanediol, 1,4-cyclohexanedimethanol, neopentyl glycol, or a combination thereof.

[0070] In one aspect, the polyester polymer may be a combination of two or more of the aromatic dicarboxylic acids and aliphatic glycols, and a copolymer containing a third component may also be used, but in consideration of heat resistance, chemical resistance, mechanical strength, and economy, it may be desirable to use polyethylene terephthalate.In another aspect, it may be desirable to use a biaxially stretched polyethylene terephthalate film as the substrate film.

[0071] In one aspect, the substrate film may have a thickness of 10 to 200 μm, but is not limited to this.

[0072] In one aspect, the release coating composition can be applied to at least one side of a substrate film to form a release layer.

[0073] 4.Component (B)

[0074] The release coating composition according to one aspect of the present disclosure uses component (B) as a main chain component that forms the release layer after curing. When component (B) is used, a hard release layer coating can be obtained due to a high crosslink density, and a level of hardness that exceeds that of existing silicone-based release coating compositions can be achieved. This is because, in the case of release films used in the ceramic green sheet manufacturing process for manufacturing MLCCs, it is effective to harden the release layer coating in order to adjust the release force to a desired level.

[0075] Existing silicone-based release coating compositions generally contain only silicone-based materials, such as silicone emulsions. However, silicone emulsions are difficult to cure at low temperatures and cure well at temperatures above about 230°C, making it difficult to use compositions containing only silicone emulsions at temperatures of about 150°C. Figure 2 is a schematic diagram showing film formation by low-temperature curing at temperatures below 150°C for a conventional silicone-based release coating composition and a water-based release coating composition according to an embodiment of the present invention. Referring to Figure 2, it can be seen that when using a conventional silicone-based release coating composition at temperatures below 150°C, the bonding strength with the substrate film (e.g., PET film) is low (see the diagram on the left).

[0076] For example, the film manufacturing process can be divided into an offline process, in which the finished film fabric is unwound, coated, and then rewound to produce a film, and an inline process, in which the polymer is extruded into a sheet and then coated to produce a film. The drying temperature in the offline process is a maximum of about 150°C, while the inline process can have a drying temperature of about 210-240°C during the film stretching process. Therefore, the offline process has traditionally used only non-aqueous solvents (i.e., solvent-based solvents) for curing at temperatures below 150°C.

[0077] However, due to requirements such as environmental friendliness, when the solvent for the composition is aqueous, curing must be carried out at a temperature of about 150°C or lower (for example, about 130°C or lower), and emulsions are suitable formulations that can be used in aqueous systems, but as mentioned above, when silicone emulsions are used, there is the problem that curing at temperatures below 150°C is difficult. Furthermore, even after curing, there is the problem that the rub-off properties and substrate adhesion of the release film decrease, and when a surfactant is added to solve this problem, there is the problem that curing is inhibited.

[0078] As described above, the release coating composition according to one aspect of the present disclosure includes component (B) containing two or more functional groups capable of condensation reaction with the silicone emulsion component, thereby achieving a high degree of cure at temperatures of 150°C or less and achieving excellent physical properties such as rub-off characteristics. Therefore, it is possible to use aqueous emulsions in offline processes. Referring to Figure 2, it can be seen that by utilizing component (B) (e.g., a melamine component), a phase separation curing reaction is induced, resulting in a film with excellent adhesion and a high degree of cure (see the diagram on the right).

[0079] In one aspect, component (B) can form a Si-ORN bond structure (where R is an alkyl group having 1 to 4 carbon atoms) through a silicone emulsion component condensation reaction.

[0080] For example, R can be -CH2-, -CH2CH2-, -CH2CH2CH2-, or -CH2CH2CH2CH2-.

[0081] In one aspect, the functional group contained in component (B) can be an amine group or an amine-derived functional group.

[0082] In one aspect, component (B) is not particularly limited as long as it contains two or more functional groups in one molecule that can undergo a condensation reaction with the silicone emulsion component, but it can be a melamine component, and can generally be an alkyl etherified melamine compound produced by reacting melamine with formaldehyde, followed by reacting the methylol melamine thus produced with an alcohol having an appropriate carbon number under acid catalyst conditions.

[0083] In one aspect, component (B) may refer to a melamine compound having the structure of Formula 1 below, an oligomer thereof, a polymer thereof, and / or a combination thereof.

[0084] [Chemical formula 1]

[0085] [ka]

[0086] Here, X represents a hydrogen atom, -CH2OH, or -CH2-OR, and may be the same or different. R represents an alkyl group having 1 to 8 carbon atoms, and may be the same or different. At least one X may be -CH2-O-CH3.

[0087] In one aspect, each of the X's may be -CH2-O-CH3, and the melamine compound may be a full ether type methylated melamine, a melamine oligomer, and / or a melamine polymer.

[0088] In one aspect, component (B) can be any of a variety of commercially available and widely used products, including, but not limited to, Cymel 300, Cymel 301, Cymel 303LF, Cymel 350, and Cymel 370N (all Allnex products). Commercially available products can be used alone or in combination.

[0089] In one aspect, the content of component (B) may be about 0.2 to about 1.0 wt. % based on the total weight of the entire composition, specifically about 0.2 to about 0.8 wt. %, about 0.3 to about 0.7 wt. %, about 0.4 to about 0.6 wt. %, or about 0.5 to about 0.6 wt. If component (B) is used in an excessively small amount below the minimum value, the desired curing effect, i.e., the effect of maintaining the hardness of the release layer and reducing the green sheet peel strength of the release film, may be weakened, and the peel strength may not be adjusted as desired. Furthermore, if component (B) is not cured sufficiently, the stability of the release film over time may decrease. Therefore, it is recommended that the content of component (B) satisfy the content ratio with the acid catalyst described below.

[0090] In one aspect, the total acid number of component (B) may be 390 to 780 mg KOH / g, specifically 400 KOH / g or more, 450 KOH / g or more, 500 KOH / g or more, 550 KOH / g or more, 600 KOH / g or more, 650 KOH / g or more, 700 KOH / g or more, or 750 KOH / g or more, or 730 KOH / g or less, 680 KOH / g or less, 630 KOH / g or less, 580 KOH / g or less, 530 KOH / g or less, 480 KOH / g or less, or 430 KOH / g or less, but is not limited thereto.

[0091] 5. Silicone emulsion ingredients

[0092] In one aspect of the present disclosure, a silicone emulsion component can be used as a binder or release force modifier in a release coating composition. Because component (B) has a low molecular weight monomer, it forms a dense crosslinked structure after curing, resulting in a high crosslink density. This increases the hardness of the release layer during coating, but the higher the hardness of the release layer, the lower the release force of the green sheet. To address this issue, a silicone emulsion component containing a release functional group, such as Si-CH3, and having soft properties can be co-cured to reduce the hardness and increase the softness of the release layer. As described above, increasing the softness of the release layer increases the release force of the release film. The present disclosure achieves a wide range of release forces, particularly a wide range of tape release forces at room temperature after one day, by combining component (B) and the silicone emulsion component.

[0093] The silicone emulsion component can form an Si-ON bond structure through a condensation reaction with component (B), and the formed component (B)-silicone emulsion component copolymer and this structure can increase the softness of the release layer and improve its stability over time.

[0094] For example, the melamine component of Formula 1 may have a maximum of six functional groups. In this case, the NX2 group of the melamine component may form a Si-ON bond structure through a condensation reaction with the silicone emulsion component.

[0095] Typically, silicone-based release films increase their release strength by adding a silicone polymer component. However, if the content of the silicone polymer component exceeds 50 wt % based on the total weight of the entire composition, serious problems with stability over time occur. This is because the silicone polymer component, which should be present on the surface of the release layer, impregnates into the interior of the release layer over time. Unlike conventional silicone-based release films, the release coating composition of the present disclosure, as described above, forms a crosslinked network structure by copolymerizing component (B) and the silicone emulsion component. This allows the functional groups that exhibit releasability to remain on the surface of the release layer without impregnating the interior, thereby demonstrating excellent stability over time.

[0096] In one aspect, the silicone emulsion component is not limited as long as it can combine with component (B) to form a crosslinked network structure and impart softness. For example, the silicone emulsion component may not contain any side chains other than the main chain, although there is no particular limitation.

[0097] In one embodiment, the silicone emulsion component may be free of polyalkylene glycols (eg, polyethylene glycol, PEG).

[0098] In one embodiment, the silicone emulsion component may be free of hydroxyl groups, polyether groups, and polyester groups.

[0099] In one embodiment, the silicone emulsion component may be free of alkenyl groups.

[0100] When using a silicone emulsion containing a side chain, the release properties must be limited to heavy release (200 g or more based on TESA 7475 tape), and films using compositions containing this may be limited to use in heavy release areas such as MLCC. However, in the present disclosure, as described above, the silicone emulsion component does not contain side chains such as polyalkylene glycol, hydroxyl groups, polyether groups, polyester groups, or alkenyl groups other than the main chain. Therefore, even when cured with component (B), the surface of the release layer can be formed with the Si-CH3 component, just as when using existing silicone-based curing. Therefore, it can be used not only for heavy release applications such as MLCC, but also for a variety of applications such as light release areas.

[0101] For example, the silicone emulsion component can be, but is not limited to, polydimethylsiloxane (PDMS). For example, the silicone emulsion component can be, but is not limited to, branched polydimethylsiloxane.

[0102] In one embodiment, the ratio of Si-Vi to Si-H in the silicone emulsion components may be 1:1.5 to 1:2.5. For example, the ratio of Si-Vi to Si-H in the silicone emulsion components may be 1:1.6 to 1:2.3. Here, "Si-Vi" refers to a silicone-vinyl group bond, and "Si-H" refers to a silicone-hydrogen bond. If the ratio of Si-Vi:Si-Hi in the silicone emulsion components is less than 1:1.5, the composition may not cure sufficiently during curing, resulting in poor residual adhesion and poor substrate adhesion. If the ratio of Si-Vi:Si-Hi in the silicone emulsion components exceeds 1:2.5, resulting in an excessively high Si-H content, the Si-H may react with other components (e.g., hydroxyl groups), increasing the release force over time and reducing stability over time.

[0103] In one embodiment, the content of the silicone emulsion component may be 0.02 to 9 wt%, 0.02 to 8 wt%, 0.03 to 7 wt%, 0.04 to 6 wt%, or 0.05 to 6 wt%, based on the total weight of the entire composition. If the silicone emulsion component is used in an amount exceeding the maximum value, component (B) may not cure sufficiently, and uncured silicone emulsion component or component (B) may rise to the surface of the release layer, resulting in poor rub-off properties of the release film (i.e., the adhesive strength or cohesion of the release layer to the substrate film). If the silicone emulsion component is used too little, below the minimum value, the crosslinked network structure formed by the curing reaction may not be sufficiently formed, and the desired release strength or stability over time may not be achieved.

[0104] In one embodiment, the silicone emulsion component may further include a metal catalyst. For example, but not limited to, the metal catalyst may be an alkali metal catalyst, an alkaline earth metal catalyst, or a rare earth metal catalyst. For example, but not limited to, the metal catalyst may be a platinum catalyst.

[0105] In one aspect, the weight ratio of component (B) to the silicone emulsion may be 100:10 to 100:900 on a solids basis, and may be a weight ratio lying between the upper and lower limits described above.

[0106] 6. Acid catalyst

[0107] In one aspect, the acid catalyst is not limited as long as it is known to catalyze the crosslinking reaction of component (B) or the crosslinking reaction between component (B) and a silicone emulsion component, and can be appropriately selected and used. For example, the acid catalyst can be inorganic acids such as hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, etc.; oxalic acid, acetic acid, formic acid, methanesulfonic acid, trifluoromethanesulfonic acid, isoprene sulfonic acid, camphorsulfonic acid, hexanesulfonic acid, octanesulfonic acid, nonanesulfonic acid, decane sulfonic acid, hexadecanesulfonic acid, dinonylnaphthalenesulfonic acid, dinonylnaphthalenedisulfonic acid, benzenesulfonic acid, alkylbenzenesulfonic acid, paratoluenesulfonic acid, melamine zinc iodide (melamine ZnI), melamine trisulfonic acid (melamine trisulfonic acid), methyl ... acid;MTSA), cumenesulfonic acid, dodecylbenzenesulfonic acid, naphthalenesulfonic acid, nonylnaphthalenesulfonic acid, methyl acid phosphate, ethyl acid phosphate, propyl acid phosphate, isopropyl acid phosphate, butyl acid phosphate, butoxyethyl acid phosphate, octyl acid phosphate, 2-ethylhexyl acid phosphate, decyl acid phosphate, lauryl acid phosphate, stearyl acid phosphate, oleyl acid phosphate, behenyl acid phosphate, phenyl acid phosphate, nonylphenyl acid phosphate, cyclohexyl acid phosphate, phenoxyethyl Examples of suitable acid generators that can be used include, but are not limited to, organic acids such as bisphenol A acid phosphate, alkoxypolyethylene glycol acid phosphate, bisphenol A acid phosphate, dimethyl acid phosphate, diethyl acid phosphate, dipropyl acid phosphate, diisopropyl acid phosphate, dibutyl acid phosphate, dioctyl acid phosphate, di-2-ethylhexyl acid phosphate, dilauryl acid phosphate, distearyl acid phosphate, diphenyl acid phosphate, and bisnonylphenyl acid phosphate; and thermal acid generators such as sulfonium salts, benzothiazolium salts, ammonium salts, and phosphonium salts.The acid catalyst components can be used alone or in combination of two or more.

[0108] In one aspect, the weight ratio of component (B) to acid catalyst may be 100:5 to 100:30, 100:10 to 100:20, or 100:10 to 100:15, or any weight ratio between the upper and lower limits recited above. If the amount of acid catalyst used is too low below the minimum weight ratio, the curing reaction will not occur sufficiently. If the amount used exceeds the maximum weight ratio, over-curing will occur. In either case, poor stability over time may result. Therefore, to achieve excellent stability over time, it is recommended that the weight ratio of component (B) to acid catalyst satisfy the above range.

[0109] 7. Solvent

[0110] In one aspect, the release coating composition can be a water-based release coating composition. In one aspect, water-based can mean an aqueous solution or dispersion, and can mean a composition in which the solvent component is water alone or a combination of water and an organic solvent as described below.

[0111] In one aspect, because the aqueous release coating composition is water-based, it can drastically reduce the amount of volatile organic compounds (VOCs) emitted when forming a release layer, thereby satisfying the requirement of environmental friendliness. Furthermore, it can be easily used by mixing with aqueous additives such as aqueous antistatic agents, and has the advantage of being able to achieve both antistatic properties and releasability of the release film with a one-component formulation.

[0112] In one aspect, the release coating composition may further comprise an aqueous solvent, which may be water or a combination of water and an organic solvent, with the weight ratio of water to organic solvent being 50:50 or greater, 60:40 or greater, 70:30 or greater, 80:20 or greater, 85:15 or greater, 90:10 or greater, 95:5 or greater, or 99:1 or greater.

[0113] In one aspect, the organic solvent may be a known organic solvent widely used in the field of release films, and is not particularly limited as long as it is a solvent that is compatible with water. For example, the organic solvent may be one or more selected from the group consisting of isopropyl alcohol, isobutyl alcohol, hexane, acetone, ethyl acetate, ethylene glycol, propylene glycol, butyl glycol, dipropylene glycol, polyethylene glycol, gamma-butyrolactone, and combinations thereof, but is not limited thereto.

[0114] 8. Other ingredients

[0115] In one aspect, the release coating composition may further include one or more of an antistatic agent, a conductivity enhancer, a pH adjuster, a surfactant, and an antifouling agent, within limits that do not change the physical properties (e.g., frame) of the release layer to be achieved.

[0116] (1) Antistatic agents and conductivity improvers

[0117] In one aspect of the present disclosure, the antistatic agent not only imparts antistatic properties to the release layer but also prevents the adsorption of foreign matter. The ceramic green sheet manufacturing process includes a cutting and shredding process for the ceramic green sheet. Because the ceramic green sheet is composed of a collection of beads, the beads can fall off during the cutting process. Therefore, the antistatic property can prevent the beads from falling off due to static electricity during the cutting process of the release film together with the ceramic green sheet, thereby contributing to the processability of the ceramic green sheet manufacturing process.

[0118] In one aspect, the antistatic agent may be a known antistatic agent widely used in the field of release films, and is not particularly limited thereto. For example, the antistatic agent may be selected from the group consisting of PEDOT (Poly(3,4-ethylenedioxythiophene)), PEDOT:PSS (Poly(3,4-ethylenedioxythiophene) polystyrene sulfonate), polyaniline, polypyrrole, quaternary ammonium salts, sulfonates, and phosphates, but is not limited thereto.

[0119] In one aspect, the antistatic agent may be included in the release coating composition in the form of an aqueous solution containing the antistatic agent as a solid component (the solid content may be 1.0% to 2.0% or 1.5% to 2.0%). In this case, the content of the aqueous solution containing the antistatic agent may be about 0.1 to about 30 wt %, about 1 to about 25 wt %, or about 5 to about 20 wt %, based on the total weight of the entire composition, and may be a content between the upper and lower limits described above. If the content of the antistatic agent is used in an excessive amount exceeding the maximum value, defects may occur in the appearance of the release layer, and such defects may be seen as blue spots.

[0120] In one aspect, the antistatic agent is present in the release layer in the amount of about 10 4 ~10 10 It is possible to impart a surface resistance of ohm / sq.

[0121] In one aspect, the release coating composition may further include a conductivity enhancer to achieve a desired level of surface resistance, i.e., antistatic performance. Such a conductivity enhancer may serve to enhance the performance of the antistatic agent, and the use of a conductivity enhancer may allow a desired level of surface resistance of the release layer to be achieved even with a smaller amount of antistatic agent.

[0122] In one aspect, the content of the conductivity enhancer may be about 1 to 20 wt%, about 1 to 15 wt%, about 1 to 10 wt%, about 1 to 8 wt%, about 1.5 to 8 wt%, about 1.5 to 6 wt%, about 2 to 6 wt%, about 2.5 to 6 wt%, about 3 to 6 wt%, or about 4 to 6 wt%, based on the total weight of the entire composition. If the content of the conductivity enhancer is used in an excessive amount exceeding the maximum value, curing of the release layer may be hindered, and the appearance and rub-off properties of the release layer may not be achieved to the desired level. If the content of the conductivity enhancer is used too little, below the minimum value, the effect may be insufficient.

[0123] In one aspect, the conductivity enhancer may be a known conductivity enhancer that has been widely used in the field of release films, and is not particularly limited thereto. For example, the conductivity enhancer may be selected from the group consisting of ethylene glycol, dimethyl sulfoxide, N-methyl-2-pyrrolidone, propylene glycol, butyl glycol, dipropylene glycol dimethyl ether, gamma-butyrolactone, sulfolane, dimethyl carbonate, and sorbitol, but is not limited thereto.

[0124] (2) pH adjuster

[0125] In one aspect of the present disclosure, a pH adjuster can adjust the pH of the entire composition to a desired level. The release coating composition may contain an acidic antistatic agent. When the composition becomes acidic, neutral or basic components such as surfactants or silicone emulsion components may not function properly, making pH adjustment necessary. If the pH of the entire release coating composition is not adjusted, the stability of the composition itself may rapidly deteriorate over time, and the appearance of the release layer may deteriorate over time after preparation. For example, if a release coating composition is prepared and immediately applied to a substrate film to form a release layer, the appearance may be good. However, if the release layer is formed about four hours after preparation, the appearance of the release layer may become mottled.

[0126] In one aspect, the pH adjuster may be a known pH adjuster widely known in the field of release films, and is not particularly limited. For example, the pH adjuster may be one or more selected from the group consisting of sodium hydroxide, potassium hydroxide, calcium hydroxide, and aqueous ammonia, but is not limited thereto. The pH adjuster may be a basic pH adjuster.

[0127] In one aspect, the content of the pH adjuster may be 0.05 to 0.3 wt %, 0.1 to 0.3 wt %, or 0.15 to 0.25 wt % based on the total weight of the entire composition, and may be a content between the upper and lower limits described above. If the pH adjuster is used in an amount exceeding the maximum value, curing of the release layer may be hindered.

[0128] (3) Surfactants

[0129] In one aspect of the present disclosure, the surfactant can improve the wetting properties of the release coating composition or its applicability to a substrate film, and can improve the compatibility of component (B) with the silicone emulsion component. In one aspect, when water is used as the sole solvent in the aqueous release coating composition, two or more different surfactants can be used.

[0130] In one aspect, the surfactant may be a component capable of lowering surface tension as a known surfactant widely known in the field of release films, and is not particularly limited thereto. For example, the surfactant may be, but is not limited to, a cationic surfactant, an anionic surfactant, an amphoteric surfactant, a nonionic surfactant, a silicone surfactant, a modified silicone surfactant, a fluorine-containing surfactant, or a combination thereof.

[0131] In one aspect, the cationic surfactant can be, for example, but not limited to, an alkyltrimethylammonium salt, a dialkyldimethylammonium salt, or an alkylbenzyldimethylammonium salt.

[0132] In one aspect, the anionic surfactant may be, for example, but not limited to, a fatty acid salt, an alkyl benzene sulfonate, an alkyl sulfonate, an alkyl ether sulfonate ester salt, an alkyl polyoxyethylene sulfonate, or a monoalkyl phosphate.

[0133] In one aspect, the amphoteric surfactant can be, for example, but not limited to, alkyl dimethyl amine oxide or alkyl carboxy betaine.

[0134] In one aspect, the nonionic surfactant may be, for example, a fatty acid ethanolamide, a polyoxyethylene alkyl ether, a polyoxyethylene alkylphenyl ether, sorbitol, sorbitan, a sorbitan fatty acid ester, a polyoxyethylene sorbitan fatty acid ester, a polyoxyethylene fatty acid ester, a glycerin fatty acid ester, a propylene glycol fatty acid ester, or a polyoxyalkylene-modified silicone, but is not limited thereto.

[0135] In one aspect, the silicone surfactant may be, for example, but not limited to, polyether-modified silicone or polyglycerin-modified silicone. The structure of such modified silicone may be classified into a side chain modified type, a both-end modified type (ABA type), a one-end modified type (AB type), a both-end side chain modified type, a linear block type (ABn type), a branched type, etc., and modified silicones of any of these structures may be used.

[0136] In one aspect, the fluorine-based surfactant may be one or more selected from the group consisting of fluorine, a fluorine-containing silane-based compound, and a fluorine-containing organic compound, but is not limited thereto.

[0137] In one aspect, the content of the surfactant may be 0.05 to 0.2 wt %, 0.1 to 0.2 wt %, or 0.15 to 0.2 wt %, based on the total weight of the entire composition, and may be a content between the upper and lower limits described above.

[0138] (4) Antifouling agent

[0139] In one aspect of the present disclosure, the antifouling agent can adjust the surface energy of the release layer and impart antifouling properties. When the difference in surface energy between the substrate film and the release layer is small, the wettability and peelability of the release layer relative to the substrate film can be reduced. The antifouling agent can prevent this by lowering the surface energy of the release layer. Furthermore, since component (B) contained in the release coating composition of the present disclosure has almost no slip properties, the antifouling agent can impart slip properties to the release layer.

[0140] In one aspect, the antifouling agent may be one or more selected from the group consisting of fluorine, fluorine-containing silane compounds, and fluorine-containing organic compounds, but is not limited thereto.

[0141] For example, the antifouling agent may not contain a self-emulsifying silicone, which is not sufficiently soluble in water, making it difficult to use as a water-based solvent. Therefore, the release coating composition according to the present disclosure may contain a silicone emulsion component but may not contain a self-emulsifying silicone.

[0142] In one aspect, the content of the antifouling agent may be 0.1 to 0.3 wt %, 0.15 to 0.25 wt %, or 0.2 to 0.25 wt %, based on the total weight of the entire composition, and may be a content between the upper and lower limits described above. If the content of the antifouling agent is excessively less than the minimum value, problems such as stains remaining when the release film is peeled off may occur, and problems such as green sheet slurry particles remaining on the release layer after the release film is peeled off from the green sheet may occur.

[0143] [Example]

[0144] 1. Preparation of release coating composition

[0145] The following components were mixed to prepare release coating compositions, with the exception that the content of the silicone emulsion component was varied relative to 100 parts by weight of component (B) as shown in Table 1.

[0146] - Component (B) (melamine component) (manufacturer: SANWA CHEMICAL, product name: NIKALAC MW12LF) 0.1 to 3.0% by weight

[0147] - Silicone emulsion component (PDMS, manufacturer: DOW chemical, product name: Sol-off 7946 Emulsion) 0.01 to 26.4% by weight

[0148] - Acid catalyst (melamine catalyst) (manufacturer: Allnex, product name: Cymel (registered trademark) 4040 Catalyst) 0.1 to 3.0% by weight

[0149] - Platinum catalyst (manufacturer: DOW chemical, product name: Syl-off 7924) 0.01 to 24.0% by weight

[0150] - PEDOT aqueous solution (manufacturer: Heraus, product name: Clevios PT2) 0.5 to 20% by weight

[0151] - 9% ammonia water (manufacturer: Tokusan Pharmaceutical Co., Ltd.) 0.1 to 0.5% by weight

[0152] - Surfactant (manufacturer: BYK, product name: BYK348) 0.01 to 0.3% by weight

[0153] - Distilled water remaining

[0154] 2.Production of release film

[0155] The release coating composition thus produced was applied to at least one side of a 50 μm thick polyethylene terephthalate substrate film (manufacturer: Toray Advanced Materials, product name: XD500) using a bar coater, and then cured by heating and drying in a hot air dryer at a temperature of 150°C for 30 seconds to produce a release film with a release layer provided on the substrate.

[0156] [Comparative Example]

[0157] 1. Preparation of release coating composition

[0158] Release coating compositions were prepared in the same manner as in the Examples, except that the silicone emulsion component was omitted in Comparative Example 1, and Comparative Examples 2 to 5 contained the same silicone emulsion component as in Examples 1, 4, 6, and 7, respectively, but omitted the melamine component. Comparative Examples 6 and 7 contained, instead of the silicone emulsion component, a PEG-based silicone emulsion component (manufacturer: Silicone DNA, product name: SD-3667) in different amounts per 100 parts by weight of the melamine component, as shown in Table 1.

[0159] 2.Production of release film

[0160] A release film having a release layer was prepared using the release coating composition of the comparative example in the same manner as in the above example.

[0161] [Experimental Example 1] Measurement of green sheet peeling force and stability over time

[0162] 50 parts by mass of barium titanate (BaTiO3; manufactured by Sakai Chemical Industry Co., Ltd., product name: BT-03), 5 parts by mass of polyvinyl butyral (manufactured by Sekisui Chemical Co., Ltd., product name: S-LEC B·KBM-2), and 2 parts by mass of dioctyl phthalate (manufactured by Kanto Chemical Co., Ltd., product name: Dioctyl Phthalate Grade 1) were added to 69 parts by mass of toluene and 46 parts by mass of ethanol, and the mixture was mixed and dispersed in a ball mill to produce a ceramic slurry.

[0163] In the examples and comparative examples, the ceramic slurry was uniformly applied to the surface of the release layer of the release film, which had been stored at room temperature for 48 hours after production, using an applicator. The film was then dried in a dryer at 80°C for 1 minute. Finally, a ceramic green sheet with a thickness of 3 μm was obtained on the release film, and a release film with a ceramic green sheet attached was manufactured.

[0164] The release film with the ceramic green sheet attached was stored for 24 hours and 90 days under conditions of room temperature of 23°C and humidity of 50%. After that, acrylic adhesive tape (manufactured by Nitto Denko Corporation, product name: 31B tape) was adhered to the surface of the ceramic green sheet opposite to the release film, and in this state, it was cut into a 25 mm width to prepare a measurement sample.

[0165] The adhesive tape side of the measurement sample was fixed to a flat plate, and then the release film was peeled off from the ceramic green sheet at a peel angle of 90° and a peel rate of 500 mm / min using a tensile tester (AR-1000 from ChemInstrument), and the peel strength (gf / 25 mm) was measured. The average value of the five measurements is shown in Table 1.

[0166] [Experimental Example 2] Measurement of tape peeling force

[0167] The release strength of the release films prepared by applying the release coating compositions prepared in the Examples and Comparative Examples was evaluated using TESA 7475 tape (manufactured by TESA, Germany), a standard tape widely used in the technical field of the present disclosure.

[0168] A standard TESA7475 tape was applied to the release coating surface of the release layer using a 2 kg roller, and the peel force was measured after 20 minutes at room temperature or after 24 hours at room temperature. The peel force was measured five times using a ChemInstrument AR-1000 device at a 180° peel angle and a peel speed of 12 in / min, and the average value was calculated.

[0169] [Experimental Example 3] Measurement of silicone content

[0170] The silicone content in the release layer of the release films prepared in the examples and comparative examples was measured using an X-ray fluorescence analyzer (XRF) (manufactured by Oxford, product name: LAB X-3500).

[0171] [Experimental Example 4] Measurement of residual adhesion rate

[0172] The measurement samples of the release films prepared in the examples and comparative examples were stored at 25°C and 65% RH for 24 hours, and then Nitto 31B tape, a standard tape, was applied to the release coating surface. The samples were then heated at room temperature with a 20 g / cm 2 The tape was adhered to the release coated surface for 24 hours under a load of 1000 kJ / cm. After the tape was collected without contamination, it was adhered to a flat and clean polyethylene terephthalate (PET) film surface, and the tape was pressed back and forth once with a 2 kg tape roller, after which the peel force was measured.

[0173] For comparison, a Nitto 31B tape that had never been used was adhered to a flat, clean PET film surface, and then pressed back and forth once with a 2 kg tape roller, after which the peel force was measured.

[0174] The peel force was measured as follows, and the residual adhesion was calculated from it by Equation 1.

[0175] Measurement equipment: ChemInstrument AR-1000 equipment

[0176] Measurement method: 180° peel angle, peel speed 30mm / min

[0177] <Number 1>

[0178] Residual adhesion rate (%) = [peel strength of adhesive tape adhered to the surface of the release layer and then peeled off / peel strength of adhesive tape not brought into contact with the surface of the release layer] x 100

[0179] [Experimental Example 5] Measurement of surface energy

[0180] Distilled water and diiodomethane were dropped onto the release coating surface of the release films prepared in the examples and comparative examples using a contact angle tester (manufactured by KRUSS, product name: DSA-100) to measure the contact angle of each. The measured contact angle values ​​were then substituted into the Owens-Wendt model to calculate the surface energy.

[0181] [Experimental Example 6] Rub-off test

[0182] The release layer of each of the release films prepared in the Examples and Comparative Examples was rubbed with a thumb 10 times, and the degree of change in the surface of the release layer was observed with the naked eye. As a result, the rub-off properties were evaluated as follows:

[0183] ◎: No change after evaluation

[0184] ○: There is slight rubbing, but no problems with use

[0185] △: When the surface of the release layer turns white

[0186] X: When the release layer peels off

[0187] The results obtained from the above experimental examples are shown in Table 1 below.

[0188] [Table 1]

[0189] According to the results in Table 1, the release films obtained using the release coating composition according to one aspect of the present disclosure exhibited superior residual adhesion and rub-off properties compared to the comparative examples, while also achieving a wide range of room temperature 1-day tape peel strength. Therefore, they have the advantage of being useful in a variety of industrial fields. Furthermore, their excellent residual adhesion and rub-off properties confirm that low-temperature curing is possible. Comparative Examples 2 to 5, which are release films containing silicone-based release coating compositions conventionally used in the art, exhibited poor residual adhesion and surface energy, resulting in very poor rub-off properties. That is, silicone emulsions alone exhibited low residual adhesion and poor rub-off properties, making low-temperature curing difficult. Meanwhile, in the examples, the combination of a melamine component and a silicone emulsion component improves insufficient curing power while enhancing releasability through the silicone emulsion. This is because silicone emulsion has a large molecular weight and two to three reactive sites, one at each end of the molecule, making low-temperature curing difficult. On the other hand, melamine has a low molecular weight monomer and can have up to six reactive sites, making it highly reactive. This allows for excellent rub-off properties that were difficult to achieve with existing silicone-based release coating compositions.

[0190] In an example according to one aspect of the present disclosure, when the peel strength was measured on a green sheet 90 days after production, the green sheet peel strength was almost similar to that on the first day after production, demonstrating excellent stability over time.

[0191] It was also confirmed that the examples according to one aspect of the present disclosure exhibited a residual adhesion rate of at least 94% or more.

[0192] [Experimental Example 7] Measurement of FT-IR spectrum

[0193] FT-IR spectra were measured for the release layers prepared using the release coating composition of Example 1 and a conventional silicone-based release coating composition containing a self-emulsifying silicone. Specifically, using a Bruker VERTEX70 device, the release coating compositions of the examples and comparative examples were applied to glass plates and cured by heating and drying in a hot air oven at 150°C for 30 seconds. 0.1 g of the coating layer was then sampled with a ceramic knife and the spectrum was measured using the ATR method on the measuring device. The FT-IR spectrum results are shown in Figure 3.

[0194] According to FIG. 3, the release layer of the present disclosure has a thickness of about 1020 cm -1 , approx. 1090cm -1 The Si-O stretching absorption band at approximately 800 cm -1 It can be seen that the band in this region shows a high absorption peak intensity due to the influence of the Si-C stretching absorption band. This peak intensity can be interpreted as indicating that the release layer contains components derived from PDMS.

Claims

1. a base film; and a release layer formed by applying a release coating composition to at least one surface of the base film; the release coating composition comprises a melamine component and a silicone emulsion component, the silicone emulsion component does not comprise a side chain; In the depth profile measured from the surface of the release layer in the thickness direction using a time-of-flight secondary ion mass spectrometer (TOF-SIMS), － NH in the ionic strength curve － The maximum count number of ions and the NH － Ion count, NH at the boundary between the release layer and the base film － The number of ion counts is I ＮＨ＿ｍａｘ , I ＮＨ＿ｔ , I ＮＨ＿ｂ When I ＮＨ＿ｔ / I ＮＨ＿ｍａｘ The ratio of I is 0.90 or less, ＮＨ＿ｔ >I ＮＨ＿ｂ That is, release film.

2. Said NH － The release film according to claim 1 , wherein the ionic strength curve of

3. Said NH － 2. The release film of claim 1, wherein the ionic strength curve of has a concave shape.

4. The substrate film comprises a polyethylene terephthalate polymer, and the release layer comprises Si － , S － , C ７ H ５ O ２ － , and C ３ H ５ N ５ － The release film of claim 1 further comprising one or more of the following ions:

5. The release layer is made of Si － ions and C ７ H ５ O ２ － Contains ions, In a depth profile measured by TOF-SIMS from the surface of the release layer in the thickness direction, Si － The ionic strength of C decreases ７ H ５ O ２ － The ionic strength of increases, The release layer － Ion and C ７ H ５ O ２ － The release film according to claim 4 , wherein the ions have the same ionic strength at certain points.

6. The release layer is S － Contains ions, In a depth profile measured by TOF-SIMS from the surface of the release layer in the thickness direction, S － The release film according to claim 4 , wherein the ionic strength curve of formula (I) includes an inflection point.

7. The S － The release film according to claim 6 , wherein the ionic strength curve of

8. The release layer is ３ H ５ N ５ － Contains ions, In a depth profile measured using TOF-SIMS from the surface of the release layer in the thickness direction, C ３ H ５ N ５ － The release film of claim 4 , wherein the ionic strength of

9. 10. The release film of claim 1, which exhibits a tape instant peel force of 5 to 32 gf / in.

10. 2. The release film according to claim 1, which exhibits a tape peel strength at room temperature for one day of 3 to 1000 gf / in.

11. 2. The release film according to claim 1, which exhibits a green sheet peel force of 1 to 3 gf / in.

12. The silicone content of the release layer measured using an X-ray fluorescence analyzer (XRF) is 0.001 to 0.2 g / m ２ The release film according to claim 1 , wherein

13. 2. The release film according to claim 1, wherein the surface energy of the release layer is 19 to 30 dyne / cm.

14. 2. The release film according to claim 1, comprising a release layer formed by curing the release coating composition at a temperature of 150°C or less.

15. a silicone emulsion component (A) containing polydimethylsiloxane (PDMS); Component (B) containing, in one molecule, two or more functional groups capable of undergoing a condensation reaction with the silicone emulsion component; and 10. The release film of claim 1, which is a water-based release coating composition that includes an acid catalyst.

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