Release film containing fluorine groups and its manufacturing method

Abstract

The fluorinated release film according to the present invention comprises: a base film; and a release layer located on at least one surface of the base film and formed by applying a release coating solution comprising a fluorinated organopolysiloxane (A) and a non-fluorinated organopolysiloxane (B) to at least one surface of the base film. Therefore, the coating solution can be diluted and coated without the use of fluorine-based solvents, which improves processability and results in less haze variation during routine abrasion tests due to improved crosslinking. A uniform coating can also be obtained, thereby improving peelability and peel force variation. Furthermore, the amount of expensive fluorinated organopolysiloxanes can be reduced, thus enabling the manufacture of products with excellent physical properties and high cost-effectiveness. When the fluorinated release film according to the present invention is applied to silicone-based adhesive processing, cost reduction and excellent physical properties can be achieved.

Description

Technical Field

[0001] This invention relates to release films, and more particularly to fluorinated release films and methods for manufacturing the same, wherein at least one surface of a polyester base film is coated with a release coating solution comprising an organopolysiloxane containing fluorinated groups and an organopolysiloxane without fluorinated groups, and has improved crosslinking and less haze variation. Background Technology

[0002] Silicone-based adhesives typically possess advantages such as heat resistance, abrasion resistance, and flexibility, and have therefore been widely used in flexible displays and other applications. Furthermore, silicone-based adhesives excel in electrical insulation, low toxicity, and cold resistance, making them suitable for a wide range of applications.

[0003] For the use of such silicone-based adhesives, a release film with excellent peelability is required. In the case of commonly known silicone-based release films, the release coating cannot be peeled off from the silicone-based adhesive layer when laminated together due to the good compatibility between the silicone of the release coating and the silicone-based adhesive layer. For this reason, films coated with a release agent containing a fluorine-based resin are often used as release films for silicone-based adhesives.

[0004] However, release agents containing fluorine-based resins have low surface energy and poor compatibility with common organic solvents, which can cause coating defects such as pinholes. Therefore, fluorine-based solvents are required when dissolving or applying the coating solution. Furthermore, due to the high volatility of such fluorine-based solvents, it is difficult to maintain a constant coating thickness during film coating. This can lead to pitting on the coating due to poor leveling and variations in peel force due to changes in coating thickness. Therefore, to address the problem that fluorine-based polymers cannot be dissolved in fluorine-free organic solvents, combinations of phenyl-containing silicone adhesives and addition-reactive silicone release agents have been proposed to enable peeling, but these combinations suffer from problems such as peel force increasing over time.

[0005] Furthermore, when the degree of crosslinking of release agents containing fluorine-based resins is evaluated by rub-off tests, changes in physical properties such as partial push-back and fogging occur.

[0006] Furthermore, in the case of fluorine-based solvents and release agents containing fluorine-based resins, they are dozens of times more expensive than general organic solvents and silicone-based release agents, thus being disadvantageous in terms of productivity. Although silicone-based adhesives have excellent properties, these disadvantages have prevented exponential growth in the use of release films. Summary of the Invention

[0007] Technical issues

[0008] The present invention was designed to solve the above problems and meet conventional requirements, and aims to provide a fluorinated release film and a method for manufacturing the same, wherein the fluorinated release film has excellent peelability due to improved coating properties, excellent appearance properties of its release layer, and small haze variation during conventional abrasion tests due to improved crosslinking.

[0009] The foregoing and other objects and advantages of the present invention will become apparent to those skilled in the art from the following description illustrating preferred embodiments of the invention.

[0010] Technical solution

[0011] The above objective is achieved by a release film containing fluorine groups, the release film comprising: a base film; and a release layer located on at least one surface of the base film and formed by applying a release coating solution containing an organopolysiloxane A containing fluorine groups and an organopolysiloxane B without fluorine groups to at least one surface of the base film.

[0012] Preferably, the haze change of the release film after the following test can be 5.0% or less: in the test, an abrasion-resistant nonwoven fabric without foreign matter is placed on the surface of the release layer and held under a load of 300 g, and then the abrasion-resistant nonwoven fabric is subjected to 5 reciprocating motions using a friction testing machine (CT-RB series).

[0013] Preferably, according to XPS (X-ray photoelectron spectroscopy) analysis, the fluorine (F) / silicon (Si) ratio on the surface of the release layer can be from 1.5 to 3.0, and according to XPS analysis, the F / Si ratio of the core of the release film adjacent to the base film can be from 0.2 to 0.8.

[0014] Preferably, the release layer may have a decreasing fluorine / silicon atom content ratio from the surface to the core.

[0015] Preferably, the residual adhesion rate of the fluorinated release film can be 85% or greater.

[0016] Preferably, the release film containing fluorinated groups has a peel strength of 10 gf / inch or less, which is measured by placing the release film at 25°C and 65% RH for 24 hours, and then adhering a silicone-based adhesive tape (MY2G, Taiwan) to the surface of the release layer, wherein the tape is subjected to a peel strength of 20 g / cm at 50°C. 2 The strip is pressed under a load for 24 hours, and then peeled off at a peeling angle of 180° and a peeling speed of 0.3 mpm.

[0017] Preferably, the fluorinated organopolysiloxane A may contain at least one fluorinated substituent selected from alkenyl groups having 2 to 10 carbon atoms, and fluoroalkyl or fluoroether groups in one molecule.

[0018] Preferably, the fluorine-free organopolysiloxane B may contain an alkenyl or alkyl group having 2 to 10 carbon atoms in one molecule.

[0019] Preferably, the content of organopolysiloxane A containing fluorine groups, based on 100 parts by weight, and organopolysiloxane B without fluorine groups, can be from 60 parts by weight to 300 parts by weight.

[0020] Preferably, the release coating solution may also contain hydrogen polysiloxane and platinum chelate catalyst.

[0021] Preferably, based on 100 parts by weight of fluorinated organopolysiloxane A, the content of hydrogen polysiloxane can be 3 to 4 parts by weight.

[0022] Preferably, the release coating solution may contain a platinum chelate catalyst in an amount of 410 ppm to 890 ppm.

[0023] Preferably, based on an alkenyl group of the organopolysiloxane A containing all fluorine groups and the organopolysiloxane B containing no fluorine groups, the hydrogen polysiloxane may have 1.0 to 3.0 hydrogen groups bonded to silicon atoms.

[0024] Preferably, the thickness of the release layer after drying can be from 0.03 µm to 2.0 µm.

[0025] Furthermore, the above objective is achieved by a method for manufacturing a release film containing fluorine groups, the method comprising: preparing a base film, and forming a release film by applying a release coating solution to at least one surface of the base film and drying the release coating solution, the release coating solution comprising a fluorine-containing organopolysiloxane A, a fluorine-free organopolysiloxane B, a hydrogen polysiloxane, and a platinum chelate catalyst, wherein the haze change is 5.0% or less after the following test: in the test, an abrasion-resistant nonwoven fabric free of foreign matter is placed on the surface of the release layer and held under a load of 300 g, and then the abrasion-resistant nonwoven fabric is subjected to reciprocating motion 5 times using a friction testing machine (CT-RB series).

[0026] Beneficial effects of the present invention

[0027] According to one embodiment of the invention, the fluorinated release film is not peeled off during abrasion testing and can improve common problems such as fogging due to improved crosslinking.

[0028] Furthermore, in the fluorinated release film according to one embodiment of the present invention, the amount of expensive fluorinated organopolysiloxanes used can be reduced and expensive fluorine-based solvents can be eliminated, thereby improving the cost-effectiveness of the product.

[0029] However, the effects of the present invention are not limited to those described above, and those skilled in the art will clearly understand from the following description other effects not mentioned. Attached Figure Description

[0030] Figure 1 This is a block diagram of a fluorine-containing release film according to one embodiment of the present invention. Detailed Implementation

[0031] The invention will now be described in detail with reference to examples and accompanying drawings. These examples are provided by way of illustration only for the purpose of more specifically describing the invention, and it will be apparent to those skilled in the art that the scope of the invention is not limited to these examples.

[0032] Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. In case of conflict, this specification (including definitions) shall prevail. Although similar or equivalent methods and materials to those described and used herein may be used in the practice or testing of this invention, suitable methods and materials are described herein.

[0033] As used herein, the terms “comprise,” “comprising,” “include,” “including,” “containing,” “characterized by,” “having,” or “owning,” or any other variation thereof, are intended to cover non-exclusive inclusion. For example, a process, method, article, or apparatus that includes a list of elements is not necessarily limited to those elements, but may include other elements not expressly listed or inherent to such a composition, process, method, article, or apparatus. Furthermore, unless expressly stated to the contrary, “or” means inclusive “or,” not exclusive “or.”

[0034] In describing and / or claiming protection of this invention, the term "copolymer" is used to refer to a polymer formed by the copolymerization of two or more monomers. Such copolymers include binary copolymers, ternary copolymers, or higher-order copolymers.

[0035] First, a block diagram of a fluorine-containing release film according to an embodiment of the present invention will be shown. Figure 1 A release film containing fluorine groups according to one embodiment of the present invention is described in detail.

[0036] Reference Figure 1 According to one embodiment of the invention, a fluorinated release film 100 includes a base film 10 and a release layer 20 located on at least one surface of the base film 10. The release layer 20 can be positioned by coating the base film 10 with a release coating solution comprising a fluorinated organopolysiloxane (A) and a fluorine-free organopolysiloxane (B), and further comprising a hydrogenated polysiloxane and a platinum chelate catalyst.

[0037] As a result of efforts to provide release films that can satisfy excellent release properties and appearance characteristics for silicone-based adhesives, the present invention aims to provide a release film with excellent and improved cost-effectiveness in terms of release properties and coating appearance characteristics by forming a release layer 20 by applying a release coating solution to at least one surface of a polyester base film 10, wherein the release coating solution comprises fluorinated organopolysiloxanes and fluorine-free organopolysiloxanes. The components will be described in detail below.

[0038] 1. Base membrane 10

[0039] The base film 10 is a polyester base film, and the polyester resin used therein can be a known base film commonly used in the field of conventional silicone release coatings. Specifically, the polyester base film described herein can be the polyester base film disclosed in Korean Patent Registration No. 10-1268584, which is prior art in this application. However, in embodiments of the present invention, the polyester base film is not specifically described in a limiting manner in order to illustrate only the technical features of the present invention, but it should be understood that technical features related to known polyester base films are included.

[0040] Specifically, the base film 10 will be described with an emphasis on polyester-based resins, such as polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate, but the base film of the silicone release coating solution is not limited to polyester sheets or polyester films. The polyester-based resin forming the base film can be a polyester obtained by polycondensation of an aromatic dicarboxylic acid and an aliphatic diol. Examples of aromatic dicarboxylic acids include isophthalic acid, phthalic acid, terephthalic acid, 2,6-naphthalenedicarboxylic acid, adipic acid, sebacic acid, and oxycarboxylic acid (e.g., p-hydroxybenzoic acid). Examples of aliphatic diols include ethylene glycol, diethylene glycol, propylene glycol, butanediol, 1,4-cyclohexanediol, and neopentyl glycol. As the polyester-based resin, the dicarboxylic acid component and the diol component can be used in combination of two or more types, or a copolymer containing a third component can be used.

[0041] Furthermore, the polyester base film according to one embodiment of the present invention can be a uniaxial or biaxially oriented film with high transparency and excellent productivity and processability. Representative polyester resins may include polyethylene terephthalate (PET), polyethylene 2,6-naphthalenedicarboxylate (PEN), etc.

[0042] Furthermore, the polyester base film 10 according to the invention may contain particles to impart excellent roll-to-roll running characteristics, and there are no particular restrictions on the type of particles added, as long as they can exhibit excellent sliding characteristics.

[0043] Specifically, the base membrane 10 may contain particles such as silica, silicon dioxide, calcium carbonate, calcium sulfate, calcium phosphate, magnesium carbonate, magnesium phosphate, barium carbonate, kaolin, alumina, and titanium dioxide. Although there are no particular restrictions on the shape of the particles used in the base membrane, they may preferably be any of the following: spherical, blocky, rod-shaped, plate-shaped, etc.

[0044] Furthermore, there are no particular limitations on the hardness, specific gravity, and color of the particles. If desired, these particles can be used in any combination of two or more types. The average diameter of the particles used is preferably in the range of 0.1 μm to 5 μm, more preferably 0.1 μm to 2 μm. If the average diameter of the particles is less than 0.1 μm, particle aggregation may occur, leading to insufficient dispersion. On the other hand, if the average diameter exceeds 5 μm, the surface roughness characteristics of the film decrease, resulting in coating defects during post-processing.

[0045] Furthermore, when the base film 10 of the polyester film contains particles, the particle content is preferably in the range of 0.01% to 5% by weight, more preferably in the range of 0.01% to 3% by weight. If the particle content is less than 0.01% by weight, the sliding characteristics of the polyester film decrease, leading to deterioration of the roll-to-roll running characteristics. If the particle content exceeds 5% by weight, the surface smoothness of the film may deteriorate.

[0046] There is no particular limitation on the thickness of the base film 10, but it is preferably in the range of 30 μm to 125 μm. If the thickness of the base film 10 is less than 30 μm, it is too thin and will deform due to heat treatment, while if the thickness exceeds 125 μm, it is too thick and heat cannot be transferred sufficiently, leading to problems with curing.

[0047] 2. Release layer 20

[0048] Release layer 20 is located on at least one surface of base film 10 and can be formed by coating at least one surface of base film 10 with a release coating solution comprising a fluorinated organopolysiloxane A and a fluorine-free organopolysiloxane B and also comprising a platinum chelate catalyst.

[0049] Organopolysiloxane A and organopolysiloxane B are the main components of the release coating solution of the present invention, and organopolysiloxane A and organopolysiloxane B can exist as individual molecules or can be linked as a copolymer. Furthermore, any of addition-reaction type siloxane resins, condensation-reaction type siloxane resins, and UV-curable type siloxane resins can be used, and there are no particular limitations on the type used.

[0050] In one embodiment, the fluorinated organopolysiloxane A preferably contains, in one molecule, at least one fluorinated substituent selected from an alkenyl group bonded to a silicon atom and having 2 to 10 carbon atoms, and a fluoroalkyl or fluoroether group bonded to a silicon atom.

[0051] Specifically, the fluorinated organopolysiloxane A preferably has a structure represented by Formula 1 shown below.

[0052] (Equation 1)

[0053]

[0054] In Formula 1, Ra is a monovalent hydrocarbon group with 1 to 10 carbon atoms other than an aliphatic unsaturated group, and specifically, it can be an alkyl group; an aryl group; and a group in which some or all of the hydrogen atoms of these groups are substituted with hydroxyl, cyano, etc., or substituted with alkenyl groups having 2 to 10 carbon atoms.

[0055] Rb is a monovalent hydrocarbon group with 1 to 10 carbon atoms other than an aliphatic unsaturated group, and specifically, it can be an alkyl group; an aryl group; and a group in which some or all of the hydrogen atoms of these groups are substituted with hydroxyl, cyano, etc., or substituted with alkenyl or hydrogen groups having 2 to 10 carbon atoms.

[0056] Rc has at least one fluorinated substituent selected from fluoroalkyl or fluoroether groups, and a monovalent hydrocarbon group having 1 to 10 carbon atoms other than an aliphatic unsaturated group, and specifically, it may be an alkyl group; an aryl group; and a group wherein some or all of the hydrogen atoms of these groups are substituted with at least one of a hydroxyl or cyano group in the hydrocarbon group, an alkenyl group having 2 to 10 carbon atoms, or a hydrogen group.

[0057] In addition, X, Y, and Z are each integers of 1 or greater.

[0058] Furthermore, in Formula 1, the fluoroalkyl group preferably has the structure of Formula 2 below.

[0059] (Equation 2)

[0060]

[0061] In Equation 2, n is an integer from 1 to 8, and m is an integer from 1 to 5.

[0062] Furthermore, in Formula 1, the fluoroether group preferably has the structure of Formula 3 below.

[0063] (Equation 3)

[0064]

[0065] In Equation 3, p is an integer from 1 to 5, q is an integer of 0 or 1, r is an integer from 0 to 2, m is an integer from 1 to 5, and X is an oxygen atom or a single bond.

[0066] In one embodiment, in a molecule of the fluorine-free organopolysiloxane B, alkenyl groups bonded to silicon atoms can be present in any part of the molecule, and preferably contain at least two or more alkenyl groups. Furthermore, the molecular structure is linear or branched, or a combination thereof.

[0067] Specifically, the organopolysiloxane B, which does not contain fluorine groups, preferably has a structure represented by Formula 4 shown below.

[0068] (Equation 4)

[0069]

[0070] In Formula 4, Ra is a monovalent hydrocarbon group with 1 to 10 carbon atoms, excluding aliphatic unsaturated groups, and specifically, it can be an alkyl group; an aryl group; or a group in which some or all of the hydrogen atoms of these groups are substituted with hydroxyl, cyano, etc., or substituted with an alkenyl group having 2 to 10 carbon atoms. Furthermore, Rb is a monovalent hydrocarbon group with 1 to 10 carbon atoms, excluding aliphatic unsaturated groups, and specifically, it can be an alkyl group; an aryl group; or a group in which some or all of the hydrogen atoms of these groups are substituted with hydroxyl, cyano, etc., or substituted with an alkenyl or hydrogen group having 2 to 10 carbon atoms. Additionally, X and Y are each an integer of 1 or greater.

[0071] In one embodiment, the content of organopolysiloxane A containing fluorine groups and organopolysiloxane B without fluorine groups is preferably 60 to 300 parts by weight, based on 100 parts by weight. In this case, if the amount is less than 60 parts by weight, the peel properties cannot be improved and the compatibility with non-fluorine-based solvents deteriorates, leading to problems with appearance properties during the coating process. If the amount exceeds 300 parts by weight, there are insufficient fluorine atoms on the surface of the release layer, making peeling impossible when laminated with silicone-based adhesives and release films.

[0072] In one embodiment, a hydrogenated polysiloxane is used as the curing agent for the release coating solution. Any of addition-reaction, condensation-reaction, and UV-curable hydrogenated polysiloxanes can be used, and there are no particular limitations on the type used. Furthermore, the hydrogenated polysiloxane has a linear, branched, or cyclic molecular structure, or a combination thereof. Its viscosity or molecular weight is not limited to a specific value, but it must be well-compatible with organopolysiloxane A and organopolysiloxane B. The hydrogenated polysiloxane may not have fluorine groups, but preferably has fluorine groups identical to those in organopolysiloxane A.

[0073] In one embodiment, based on 100 parts by weight of the fluorinated organopolysiloxane A, the content of hydrogen polysiloxane is preferably 3 to 4 parts by weight. If the amount of hydrogen polysiloxane content is less than 3 parts by weight, the residual adhesion rate decreases and defects may occur in the appearance, while if its amount exceeds 4 parts by weight, the peel force increases significantly. Therefore, its amount is preferably within the above range.

[0074] Furthermore, based on one alkenyl group of the organopolysiloxane A (containing all fluorine groups) and the organopolysiloxane B (containing no fluorine groups), the hydrogen polysiloxane preferably has 1.0 to 3.0 hydrogen groups bonded to silicon atoms. If the number of hydrogen groups bonded to the silicon atoms of the hydrogen polysiloxane is less than 1.0 based on one alkenyl group of the organopolysiloxane, problems may arise regarding curing. If the number exceeds 3.0, many hydrogen atoms remain in the cured coating, leading to problems such as changes in peel strength over time.

[0075] Furthermore, the release coating solution may contain a platinum chelate catalyst. In this case, the release coating solution preferably contains 410 ppm to 890 ppm of platinum chelate catalyst. If the amount of platinum chelate catalyst content is less than 410 ppm, the residual adhesion rate decreases and defects may occur in the appearance, while if its amount exceeds 890 ppm, the peeling force increases significantly. Therefore, its amount is preferably within the above range.

[0076] Furthermore, it is preferable to form the release film 20 by diluting the release coating solution in a solvent to contain a total solid content of 0.5% to 10% by weight, and then coating the release coating solution onto at least one surface of the base film 10. In this case, any type of solvent can be used as the solvent for the release coating solution without limitation, as long as it allows the solid content of the present invention to be dispersed therein and applied to the base film 10. If the total amount of solid content in the release coating solution is less than 0.5% by weight, a uniform release coating cannot be formed, which may lead to problems such as poor peeling between the silicone-based adhesive layer and the release film. If its total amount exceeds 10% by weight, the viscosity of the coating solution is high, which may cause uneven leveling of the coating, resulting in deterioration of the thickness uniformity of the release layer.

[0077] Furthermore, the release layer 20 formed by coating the base film 10 can be obtained by applying a release coating solution using conventional and known coating methods, such as bar coating, gravure coating, or die coating.

[0078] In one embodiment, the thickness of the release layer 20 after drying is preferably from 0.03 μm to 2.0 μm. If the thickness of the release layer 20 after drying is less than 0.03 μm, the coverage of the release layer 20 is poor, which may lead to problems with the release layer 20 not being able to peel off when laminated with a silicone-based adhesive. If the thickness of the release layer 20 after drying exceeds 2.0 μm, problems such as drying may occur, and the peeling characteristics cannot be improved, resulting in a deterioration in cost-effectiveness.

[0079] According to one embodiment of the invention, the haze change of the fluorinated release film 100 after the following test is preferably 5.0% or less: in which an abrasion-resistant nonwoven fabric free of foreign matter is placed on the surface of the release layer and held under a load of 300 g, and then the abrasion-resistant nonwoven fabric is subjected to reciprocating motion 5 times using a friction testing machine (CT-RB series). If the haze change after the friction test exceeds 5.0%, a pushback phenomenon may have occurred during the abrasion test.

[0080] According to one embodiment of the invention, the fluorine-containing release film 100 preferably has a decreasing fluorine / silicon atom content ratio from the surface to the core when the surface of the release layer 20 is analyzed with an XPS analyzer. As used herein, "core" means a point at which the surface of the release layer has 60% carbon atoms.

[0081] More specifically, according to XPS analysis, the fluorine (F) to silicon (Si) ratio on the surface of release layer 20 is preferably between 1.5 and 3.0. If the F / Si ratio on the surface of release layer 20 is less than 1.5, there may be a problem where release layer 20 cannot be peeled off when laminated with a silicone-based adhesive. If its F / Si ratio exceeds 3.0, the residual adhesion rate deteriorates and the haze change after the rubbing test exceeds 5%.

[0082] Furthermore, according to XPS analysis, the F / Si value of the core of the release layer 20 adjacent to the base film 10 is preferably 0.2 to 0.8. If the F / Si value of the core of the release layer 20 is less than 0.2, the fluorine group content is insufficient, which makes it difficult to peel off the release layer 20 when laminated with a silicone-based adhesive. If its F / Si value exceeds 0.8, the residual adhesion rate deteriorates and the haze change after the friction test exceeds 5%.

[0083] According to one embodiment of the invention, the residual adhesion rate of the fluorinated release film 100 is preferably 85% or greater. If the residual adhesion rate is less than 85%, the release layer 20 is not sufficiently cured, which may lead to problems such as the release agent potentially migrating to the laminated adhesive layer, and the adhesive properties of the adhesive may deteriorate.

[0084] According to one embodiment of the invention, the peel strength of the fluorinated release film 100 is preferably 10 gf / inch or less, which is measured by placing the release film 100 at 25°C and 65% RH for 24 hours, and then adhering a silicone-based adhesive tape (MY2G, Taiwan) to the surface of the release layer that is not in contact with the base film, with the tape holding at 20 g / cm. 2 The tape is pressed under load for 24 hours, then peeled off at a peel angle of 180° and a peel speed of 0.3 mpm. If the peel force exceeds 10 gf / inch, proper peeling from the silicone-based adhesive cannot be achieved, leading to problems in the process.

[0085] The configuration and effects of the present invention will be described in more detail below through embodiments and comparative examples. The following embodiments are provided to further illustrate the invention, but are not intended to limit the scope of the invention.

[0086] [Example]

[0087] [Example 1]

[0088] A release coating solution was prepared comprising 100 parts by weight of a fluorine-free organopolysiloxane B (manufactured by Dow Chemical Inc., LTC-750A), based on 100 parts by weight of a fluorinated organopolysiloxane A (manufactured by Dow Chemical Inc., Q2-7785), 4 parts by weight of a hydrogenated polysiloxane (manufactured by Dow Chemical Inc., Q2-7560), and 700 ppm of a platinum chelate catalyst (manufactured by Dow Chemical Inc., SYL-OFF 4000). The release coating solution was then diluted in heptane to obtain a total solid content of 6% by weight. The release coating solution was then applied to a polyester membrane (Toray Advanced Materials Korean Inc., XB-30, 50 μm). After application of the release coating solution, the polyester membrane was dried in a hot air dryer at 150°C for 50 seconds to produce a release film with a release layer of 0.5 μm.

[0089] [Example 2]

[0090] The release film was manufactured in the same manner as in Example 1, except that a release layer with a thickness of 2.0 μm was formed.

[0091] [Example 3]

[0092] The release film was manufactured in the same manner as in Example 1, except that 60 parts by weight of a fluorine-free organopolysiloxane B (manufactured by Dow Chemical Inc., LTC-750A) was used.

[0093] [Example 4]

[0094] The release film was manufactured in the same manner as in Example 1, except that 300 parts by weight of a fluorine-free organopolysiloxane B (manufactured by Dow Chemical Inc., LTC-750A) was used.

[0095] [Comparative Example]

[0096] [Comparative Example 1]

[0097] The release film was manufactured in the same manner as in Example 1, except that 300 parts by weight of fluorinated organopolysiloxane A (manufactured by Dow Chemical Inc., Q2-7785) was used.

[0098] [Comparative Example 2]

[0099] The release film was manufactured in the same manner as in Example 1, except that 30 parts by weight of fluorinated organopolysiloxane A (manufactured by Dow Chemical Inc., Q2-7785) was used.

[0100] [Comparative Example 3]

[0101] The release film was manufactured in the same manner as in Example 1, except that 5 parts by weight of hydrogen polysiloxane (manufactured by Dow Chemical Inc., Q2-7560) was used.

[0102] [Comparative Example 4]

[0103] The release film was manufactured in the same manner as in Example 1, except that 2 parts by weight of hydrogen polysiloxane (manufactured by Dow Chemical Inc., Q2-7560) was used.

[0104] [Comparative Example 5]

[0105] The release film was manufactured in the same manner as in Example 1, except that 900 ppm of platinum chelate catalyst (manufactured by Dow Chemical Inc., SYL-OFF 4000) was used.

[0106] [Comparative Example 6]

[0107] The release film was manufactured in the same manner as in Example 1, except that 400 ppm of platinum chelate catalyst (manufactured by Dow Chemical Inc., SYL-OFF 4000) was used.

[0108] [Comparative Example 7]

[0109] The release film was manufactured in the same manner as in Example 1, except that 310 parts by weight of a fluorine-free organopolysiloxane B (manufactured by Shin-Etsu Silicones, KS-847H) was used.

[0110] [Comparative Example 8]

[0111] The release film was manufactured in the same manner as in Example 1, except that 55 parts by weight of a fluorine-free organopolysiloxane B (manufactured by Shin-Etsu Silicones, KS-847H) was used.

[0112] [Comparative Example 9]

[0113] The release film was manufactured in the same manner as in Example 1, except that a release layer with a thickness of 2.1 μm was formed.

[0114] [Comparative Example 10]

[0115] The release film was manufactured in the same manner as in Example 1, except that a release layer with a thickness of 0.02 μm was formed.

[0116] The physical properties were measured using release films according to Examples 1 to 4 and Comparative Examples 1 to 10 through the following experimental examples, and the results are shown in Table 1 below.

[0117] [Experimental Example]

[0118] (1) XPS (X-ray photoelectron spectroscopy) analysis and evaluation of the release layer

[0119] 1-1. Surface Analysis of Release Layer

[0120] The atomic composition of the release layer surface of the release films manufactured according to the above examples and comparative examples was analyzed using an analytical XPS instrument (Thermo Fisher Scientific Inc.: product name: K-ALPHA) with a spot size of 400 μm. The results are shown in Table 1.

[0121] 1-2. Core Analysis of Release Layer

[0122] The release layer surface of the release films manufactured according to the examples and comparative examples was subjected to Ar plasma treatment at an ion energy of 3000 eV for 30 seconds and the release layer surface was etched. XPS analysis was performed under the same conditions as in "1-1. Release Layer Surface Analysis". The plasma treatment and XPS analysis were repeated until a layer with 80% or more carbon atoms was analyzed. The point at 60% carbon atoms from the surface of the release layer was called the core, and the XPS analysis results at the core are shown in Table 1 below.

[0123] 2. Measurement of the peel force of the release film

[0124] [Sample Preparation]

[0125] ① Place the release-coated sample at 25°C and 65% RH for 24 hours.

[0126] ② Adhere a silicone-based adhesive tape (MY2G, Taiwan) to the release-coated surface of the sample, and then incubate the tape at 50°C at 20 g / cm³. 2 The sample was pressed under a load for 24 hours, and then its physical properties were measured.

[0127] [Measuring Instruments]

[0128] Chemical Instrument AR-2000

[0129] [How to measure]

[0130] ① The peeling angle is 180°, and the peeling speed is 0.3 mpm.

[0131] ② The sample size is 500 mm × 1500 mm, and the size used to measure the peel force is 250 mm × 1500 mm.

[0132] [Measurement Data]

[0133] Peel force is expressed in gf / inch and the average value is calculated after five separate measurements of the peel force of the sample.

[0134] 3. Analysis of residual adhesion rate of release film

[0135] [Sample Preparation]

[0136] ① Place the release-coated sample at 25°C and 65% RH for 24 hours.

[0137] ② Adhere the standard adhesive tape (Nitto 31B) to the release-coated surface of the sample, and then heat the tape at room temperature at 20 g / cm. 2 Pressed under load for 24 hours.

[0138] ③ Remove the adhesive tape laminated on the silicone-coated surface without contamination, then adhere it to the smooth and clean PET film surface, and press it by reciprocating once with a 2 kg belt roller (ASTM D-1000-55T).

[0139] [Measuring Instruments]

[0140] Chemical Instrument AR-2000

[0141] [How to measure]

[0142] ① The peeling angle is 180°, and the peeling speed is 0.3 mpm.

[0143] ② The sample size is 500 mm × 1500 mm, and the size used to measure the peel force is 250 mm × 1500 mm.

[0144] [Measurement Data]

[0145]

[0146] 4. Measurement of haze change in release film

[0147] Release films manufactured according to the examples and comparative examples were prepared in A4 size. Using a friction testing machine (CT-RB series), abrasion-resistant nonwoven fabric free of foreign matter was placed on the surface to be rubbed and subjected to a load of 300 g for 5 cycles. Furthermore, haze was measured before and after the test using a haze meter (NDH-5000) to calculate the haze change.

[0148] 5. Appearance evaluation of release film

[0149] The appearance of the release layer surface of the implementation scheme that completed the friction test in Experimental Example 3 and the comparative example was evaluated, and the results are shown in Table 1.

[0150] ○: Good appearance (no cratering, or good film coating properties, or no scratches)

[0151] △: Partially defective appearance (1 to 3 pits, or partially poor film coating characteristics, or 1 to 3 scratches)

[0152] ×: Poor appearance (more than 3 pits, or coating defects, or more than 3 scratches)

[0153] [Table 1]

[0154]

[0155] As can be seen from Table 1, the fluorinated release films of Examples 1 to 4 of the present invention have excellent peelability to silicone-based adhesives and a small haze change of 5.0% or less, which prevents pushback during abrasion tests and results in excellent physical and appearance properties of the films.

[0156] On the other hand, it can be seen that when the composition of the organopolysiloxane in the release layer is unsuitable or the coating thickness of the release layer is not optimized, the appearance characteristics of the coating may deteriorate and the peeling characteristics may worsen.

[0157] More specifically, it can be seen that the release film according to Comparative Example 1 is unsuitable because of its high fluorine content and large haze difference.

[0158] Furthermore, it can be seen that although the haze difference of the release film according to Comparative Example 2 is good due to the lower fluorine content compared to Si, the release film is unsuitable because the F / Si value at the XPS surface is outside the preferred range, resulting in increased peel force.

[0159] Furthermore, it can be seen that in Comparative Example 3, an excessive amount of curing agent was contained, which resulted in the unreacted curing agent deteriorating the residual adhesion rate and causing an excessive increase in peel force.

[0160] Furthermore, it can be seen that in Comparative Example 4, the curing agent was included in a small amount, resulting in no curing and a poor appearance.

[0161] Furthermore, it can be seen that in Comparative Example 5, the peeling force is excessively high due to the excessive catalyst content.

[0162] Furthermore, it can be seen that in Comparative Example 6, the catalyst content is low, and as a result of the lack of curing, the residual adhesion rate is reduced and the appearance is poor.

[0163] Furthermore, it can be seen that the release film according to Comparative Example 7 is not suitable as a release film because it contains an excessive amount of organopolysiloxane B without fluorine groups, which leads to a decrease in the F / Si value of the XPS surface and an increase in the peel force.

[0164] Furthermore, it can be seen that the release film according to Comparative Example 8 is not suitable as a release film because less of the fluorine-free organopolysiloxane B is contained within it, which leads to an increase in the F / Si value of the XPS surface and an increase in haze variation, resulting in a poor appearance.

[0165] Furthermore, it can be seen that the release film according to Comparative Example 9 is unsuitable because the thickness of the release layer after drying is too large, resulting in poor appearance, increased haze difference, and increased peel force.

[0166] Furthermore, it can be seen that the release film according to Comparative Example 10 is unsuitable because the thickness of the release layer is too thin, resulting in a poor appearance and excessive increase in peel force.

[0167] As described above, the present invention provides a fluorinated release film comprising a release layer and having a haze variation of 0.5% or less under predetermined conditions. The release layer is formed by applying a release coating solution containing both a fluorinated organopolysiloxane and a non-fluorinated organopolysiloxane to at least one surface of a base film. Therefore, dilution and coating of the coating solution can be performed without using fluorine-based solvents, which improves processability and allows for a uniform coating, thereby improving peelability and peel force variation. Furthermore, the amount of expensive fluorinated organopolysiloxanes used can be reduced, enabling the manufacture of products with excellent physical properties and high cost-effectiveness. When the release film according to the present invention is applied to silicone-based adhesive processing, cost reduction and excellent physical properties can be achieved.

[0168] This specification shows only some examples of various embodiments implemented by the inventors; however, it should be noted that the technical scope of the invention is not limited thereto, and modifications and variations can certainly be made by those skilled in the art.

[0169] Figure Labels

[0170] 100: Release film containing fluorine groups

[0171] 10: Base membrane

[0172] 20: Release layer

Claims

1. A release film containing fluorine groups, comprising: Base membrane; and A release layer is located on at least one surface of the base film and is formed by applying a release coating solution comprising a fluorinated organopolysiloxane (A), a fluorine-free organopolysiloxane (B), a hydrogenated polysiloxane, and a platinum chelate catalyst to the at least one surface of the base film. The organopolysiloxane (A) containing fluorinated groups is based on 100 parts by weight, while the content of the organopolysiloxane (B) without fluorinated groups is from 60 parts by weight to 300 parts by weight. The organopolysiloxane (A) containing fluorinated groups is based on 100 parts by weight, and the content of the hydrogen polysiloxane is 3 to 4 parts by weight. The release coating solution contains the platinum chelate catalyst in an amount of 700 ppm to 890 ppm. The release layer, after drying, has a thickness of 0.5 µm to 2.0 µm. According to XPS (X-ray photoelectron spectroscopy) analysis, the fluorine (F) / silicon (Si) ratio on the surface of the release layer is 1.5 to 3.0, and according to the same XPS analysis, the F / Si ratio in the core of the release film adjacent to the base film is 0.7 to 0.

8. The haze change of the release film containing the fluorine group is 5.0% or less after the following test: in the test, an abrasion-resistant nonwoven fabric without foreign matter is placed on the surface of the release layer and held under a load of 300 g, and then the abrasion-resistant nonwoven fabric is reciprocated 5 times using a friction testing machine.

2. The fluorine-containing release film according to claim 1, wherein the release layer has a decreasing fluorine / silicon atom content ratio from the surface to the core.

3. The fluorine-containing release film according to claim 1, wherein the residual adhesion rate of the fluorine-containing release film is 85% or greater.

4. The fluorine-containing release film according to claim 1, having a peel strength of 10 gf / inch or less, said peel strength being measured by: placing the release film at 25°C and 65% RH for 24 hours, then adhering a silicone-based adhesive tape to the surface of the release layer, and subjecting the tape to a peel strength of 20 g / cm at 50°C. 2 The strip is pressed under a load for 24 hours, and then peeled off at a peeling angle of 180° and a peeling speed of 0.3 mpm.

5. The fluorinated release film according to claim 1, wherein the fluorinated organopolysiloxane (A) comprises, in one molecule, at least one fluorinated substituent selected from an alkenyl group having 2 to 10 carbon atoms, and a fluoroalkyl or fluoroether group.

6. The fluorinated release film according to claim 1, wherein the fluorine-free organopolysiloxane (B) contains an alkenyl or alkyl group having 2 to 10 carbon atoms in one molecule.

7. The release film containing fluorine groups according to claim 1, wherein the content of the organopolysiloxane (A) containing fluorine groups is 100 parts by weight based on 100 parts by weight of the organopolysiloxane (B) without fluorine groups.

8. The release film containing fluorine groups according to claim 1, wherein the hydrogen polysiloxane has 1.0 to 3.0 hydrogen groups bonded to silicon atoms, based on an alkenyl group of all of the fluorine-containing organopolysiloxane (A) and the fluorine-free organopolysiloxane (B).

9. The release film containing fluorinated groups according to claim 1, wherein the content of the hydrogen polysiloxane is 4 parts by weight, based on 100 parts by weight of the organopolysiloxane (A) containing fluorinated groups.

10. The fluorine-containing release film according to claim 1, wherein the release coating solution contains the platinum chelate catalyst in an amount of 700 ppm.

11. A method for manufacturing a release film containing fluorine groups, comprising: Prepare the base membrane; as well as A release layer is formed by applying a release coating solution to at least one surface of the base membrane and drying the release coating solution, wherein the release coating solution comprises a fluorinated organopolysiloxane (A), a fluorine-free organopolysiloxane (B), a hydrogenated polysiloxane, and a platinum chelate catalyst. The organopolysiloxane (A) containing fluorinated groups is based on 100 parts by weight, while the content of the organopolysiloxane (B) without fluorinated groups is from 60 parts by weight to 300 parts by weight. The organopolysiloxane (A) containing fluorinated groups is based on 100 parts by weight, and the content of the hydrogen polysiloxane is 3 to 4 parts by weight. The release coating solution contains the platinum chelate catalyst in an amount of 700 ppm to 890 ppm. The release layer, after drying, has a thickness of 0.5 µm to 2.0 µm. According to XPS (X-ray photoelectron spectroscopy) analysis, the fluorine (F) / silicon (Si) ratio on the surface of the release layer is 1.5 to 3.0, and according to the same XPS analysis, the F / Si ratio in the core of the release film adjacent to the base film is 0.7 to 0.

8. The haze change of the release film containing the fluorine group is 5.0% or less after the following test: in the test, an abrasion-resistant nonwoven fabric without foreign matter is placed on the surface of the release layer and held under a load of 300 g, and then the abrasion-resistant nonwoven fabric is reciprocated 5 times using a friction testing machine.

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