Fluorosilicone release coating composition and release liner

Abstract

Provided is a fluorosilicone release coating composition, which comprises: (A) a linear organopolysiloxane having at least two alkenyl groups and at least one fluoroalkyl group per molecule, and no silicon-bonded hydrogen atoms; (B) a branched organopolysiloxane having at least one fluoroalkyl group per molecule, and no silicon-bonded hydrogen atoms; (C) a linear organopolysiloxane having at least one fluoroalkyl group per molecule, and no aliphatic unsaturated groups or silicon-bonded hydrogen atoms; (D) an organohydrogenpolysiloxane having at least two silicon-bonded hydrogen atoms and at least one fluoroalkyl group per molecule; and (E) an effective amount of a hydrosilylation reaction catalyst.This composition can form a release coating that exhibits stable and low release force for silicone pressure-sensitive adhesives with low glass transition temperature.

Description

[Technical Field]

[0001] The present invention relates to a fluorosilicone release coating composition and a release liner employing the same. [Background technology]

[0002] Silicone pressure-sensitive adhesives (Si-PSA) are widely used in many applications, such as electronic devices, industrial processing, packaging, protective films, and vehicles, due to their excellent wettability, heat resistance, cold resistance, weather resistance, chemical resistance, and electrical insulation. Si-PSA is typically used in the form of single-sided or double-sided tape or Si-PSA film. To achieve easy release, a fluorosilicone (F-Si)-based release liner is commonly used to form a laminate with the tape or film. Therefore, the F-Si-based release liner can provide protection and easy release for the Si-PSA during use.

[0003] For example, Patent Document 1 discloses a curable silicone composition that includes (A) an organopolysiloxane having alkenyl groups and perfluoroalkenyl-substituted organic groups, an organohydrogenpolysiloxane, and a catalyst for an addition reaction, and that is capable of forming a cured coating that adheres firmly to a variety of substrates and has good release properties, stable release properties, water and oil repellency, and solvent resistance.

[0004] Patent Document 2 discloses a silicone composition comprising: (A) an organopolysiloxane having at least two alkenyl groups and at least one perfluoropolyether-substituted alkyl group per molecule, and having a fluorine content of 20 to 40% by weight; (B) an organohydrogenpolysiloxane having at least three silicon-bonded hydrogen atoms per molecule; (C) a linear perfluoropolyether antifoaming agent; and (D) a platinum group metal catalyst; the composition provides a cured coating that requires only a low peel force and causes little reduction in residual adhesion rate.

[0005] Patent Document 3 discloses a solventless release agent composition for use with silicone pressure-sensitive adhesives, comprising: (A) an organopolysiloxane having at least two alkenyl groups and at least one perfluoropolyether-substituted alkyl group per molecule, and having a fluorine content of 30 to 50% by weight of the molecule, and a viscosity at 25°C of 100 to 2000 mPa·s; (B) an organohydrogenpolysiloxane having at least three silicon-bonded hydrogen atoms per molecule; (C) a reaction modifier; and (D) a platinum group metal catalyst; the composition is coated on a substrate and cured to form a release liner for use with Si-PSAs.

[0006] Patent Document 4 discloses a silicone release coating composition for Si-PSA, which comprises: (A) an organopolysiloxane having at least two alkenyl groups per molecule and having a fluoroalkyl group and a fluoropolyether group; (B) an organohydrogenpolysiloxane having at least three silicon-bonded hydrogen atoms per molecule; and (C) a platinum group metal catalyst, and which is capable of forming a cured coating whose release force for Si-PSA can be controlled within a medium to strong range.

[0007] Patent Document 5 discloses a silicone release coating composition comprising: (A) a linear or branched organopolysiloxane having per molecule at least two alkenyl-containing organic groups and at least one aryl-containing organic group, and no fluorine-containing organic groups; (B) a linear or branched organopolysiloxane having per molecule at least one alkenyl-containing organic group and at least one fluorine-containing organic group; (C) an organohydrogenpolysiloxane having per molecule at least three silicon-bonded hydrogen atoms and no fluorine-containing organic groups; (D) a platinum group metal catalyst; and (E) an organohydrogenpolysiloxane having per molecule at least one silicon-bonded hydrogen atom and a fluorine-containing organic group, wherein this composition is capable of forming a release film having extremely low release force to Si-PSA and excellent residual adhesion after release.

[0008] In recent years, consumer electronics devices, such as smartphones, pads, and even foldable phones, have become increasingly popular. These applications, especially foldable optical clear adhesive (OCA) applications, require high-performance Si-PSA. Si-PSA for OCA is usually coated on an F-Si release liner and cured to form a film, and the other side of the film is laminated to another layer of F-Si release liner, thus forming a sandwich structure. Each F-Si release liner on both sides requires a sufficiently low release force (e.g., less than 10 gf / inch) on one side and a moderate release force (e.g., less than 40 gf / inch) on the other side. OCA films are required to exhibit high adhesion and a low glass transition temperature, and are also required to pass hundreds of thousands of folding tests. These high requirements for Si-PSA result in high requirements for F-Si release liners, resulting in F-Si release coating compositions.

[0009] However, the above compositions have problems in forming release liners that can be peeled from Si-PSAs with low peel force. That is, current F-Si release coatings have not been able to provide sufficient low release performance on both the light side with dry lamination and the tight side with wet coating. In particular, there are problems in forming release liners that can be peeled from Si-PSAs with low glass transition temperatures of 30°C or less, which are used as OCAs for dry lamination, with sufficiently low peel force, and at the same time, there are problems in forming release liners that can provide moderate peel force from Si-PSAs with low glass transition temperatures of 30°C or less, which are used as OCAs for direct coating.

[0010] Prior art documents Patent documents Patent Document 1: U.S. Patent No. 5,204,436(A) Patent Document 2: U.S. Patent Application Publication No. 2004 / 0186225(A1) Patent Document 3: U.S. Patent Application Publication No. 2011 / 0251339(A1) Patent Document 4: Japanese Patent Application Laid-Open No. 2017-165893(A) Patent Document 5: International Publication No. 2020 / 137835(A1) Summary of the Invention

[0011] technical issues An object of the present invention is to provide a fluorosilicone release coating composition capable of forming a release film having stable and low release force for silicone pressure-sensitive adhesives having low glass transition temperatures, and further to provide a release film having stable and low release force for silicone pressure-sensitive adhesives having low glass transition temperatures. [Means for solving the problem]

[0012] The fluorosilicone release coating composition of the present invention comprises: (A) a linear organopolysiloxane having at least two alkenyl groups and at least one fluoroalkyl group per molecule and having no silicon-bonded hydrogen atoms; (B) a branched organopolysiloxane having at least one fluoroalkyl group per molecule and no silicon-bonded hydrogen atoms; (C) a linear organopolysiloxane having at least one fluoroalkyl group per molecule and having neither an aliphatic unsaturated group nor a silicon-bonded hydrogen atom; (D) an organohydrogenpolysiloxane having at least two silicon-bonded hydrogen atoms and at least one fluoroalkyl group per molecule; (E) an effective amount of a hydrosilylation reaction catalyst; Based on the total mass of components (A) to (C), the content of component (A) is in the range of about 40 to about 90.5 mass%, the content of component (B) is in the range of about 9 to about 56 mass%, the content of component (C) is in the range of about 0.5 to about 4 mass%, and the content of component (D) is in the range of about 1 to about 15 mass parts per 100 mass parts of the total mass of components (A) to (C).

[0013] In various embodiments, component (A) has fluoroalkyl groups in an amount such that the content of fluorine atoms associated with the fluoroalkyl groups in one molecule is at least 30% by weight.

[0014] In various embodiments, component (A) has the general formula: R 1 3SiO 1 / 2 and M siloxane units represented by the general formula: R 1 2SiO 2 / 2 is an organopolysiloxane consisting essentially of D siloxane units represented by the formula: 1 are the same or different and are an alkyl group having 1 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, or a fluoroalkyl group having 1 to 12 carbon atoms, provided that at least two R1 is an alkenyl group, and at least one R 1 is a fluoroalkyl group.

[0015] In various embodiments, component (B) has fluoroalkyl groups in an amount such that the content of fluorine atoms associated with the fluoroalkyl groups per molecule is at least 15% by weight.

[0016] In various embodiments, component (B) has the general formula: R 2 3SiO 1 / 2 M siloxane units represented by the general formula: R 2 2SiO 2 / 2 D siloxane units represented by the general formula: SiO 4 / 2 wherein R 2 are the same or different and are an alkyl group having 1 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, or a fluoroalkyl group having 1 to 12 carbon atoms, provided that at least one R 2 is a fluoroalkyl group.

[0017] In various embodiments, component (C) has fluoroalkyl groups in an amount such that the content of fluorine atoms associated with the fluoroalkyl groups per molecule is at least 20% by weight.

[0018] In various embodiments, component (C) has the general formula: R 3 3SiO 1 / 2 and M siloxane units represented by the general formula: R 3 2SiO 2 / 2 is an organopolysiloxane consisting essentially of D siloxane units represented by the formula: 3are the same or different and are an alkyl group having 1 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, or a fluoroalkyl group having 1 to 12 carbon atoms, provided that at least one R 3 is a fluoroalkyl group.

[0019] In various embodiments, the fluorosilicone release coating composition further comprises (F) a hydrosilylation reaction inhibitor in an amount of about 0.01 to about 5 parts by weight, based on 100 parts by weight of the total weight of components (A) through (C).

[0020] In various embodiments, the fluorosilicone release coating composition further comprises (G) an optional amount of a solvent.

[0021] In various embodiments, the fluorosilicone release coating composition is used with a silicone pressure sensitive adhesive.

[0022] The release liner of the present invention is obtained by coating a substrate with the above-described fluorosilicone release coating composition.

[0023] In various embodiments, the substrate is a plastic film. [Effects of the Invention]

[0024] The fluorosilicone release coating compositions of the present invention can be cured to form release coatings that exhibit stable and low release forces from silicone pressure-sensitive adhesives that have low glass transition temperatures. In particular, the release liners of the present invention exhibit stable and low release forces from silicone pressure-sensitive adhesives that have low glass transition temperatures.

[0025] definition The term "comprising" or "comprise" is used in the broadest sense herein to mean and encompass "including," "consist(ing) essentially of," and "consist(ing) of." The use of "for example," "eg," "such as," and "including" to list examples does not limit the examples listed. Thus, "for example" or "such as" means "for example, but not limited to" or "such as, but not limited to," and encompasses other similar or equivalent examples. As used herein, the term "about" serves to reasonably encompass or account for slight variations in a numerical value as determined by instrumental analysis or as a result of sample handling. Such minor variations may be as little as ±0-25, ±0-10, ±0-5, or ±0-2.5% of the numerical value. Furthermore, when referring to a range of values, the term "about" applies to both numerical values. Furthermore, the term "about" may apply to multiple numerical values, even if not expressly stated. DETAILED DESCRIPTION OF THE INVENTION

[0026] <Fluorosilicone Release Coating Composition> First, the fluorosilicone release coating composition of the present invention will be described in detail.

[0027] <Component (A)> Component (A) is a linear organopolysiloxane having at least two alkenyl groups and at least one fluoroalkyl group per molecule, and no silicon-bonded hydrogen atoms. Examples of the alkenyl groups include alkenyl groups having 2 to 12 carbon atoms, such as vinyl, allyl, butenyl, pentenyl, hexenyl, heptenyl, octenyl, nonenyl, decenyl, undecenyl, and dodecenyl, with vinyl being preferred. Examples of fluoroalkyl groups include a 3,3,3-trifluoropropyl group, a 3,3,4,4,4-pentafluorobutyl group, a 3,3,4,4,5,5,5-heptafluoropentyl group, a 3,3,4,4,5,5,6,6,6-nonafluorohexyl group, a 3,3,4,4,5,5,6,6,7,7,7-undecafluoroheptyl group, a 3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluorooctyl group, and a 3,3,4,4,5,5,6,6,7 and fluoroalkyl groups having 1 to 12 carbon atoms, such as 3,3,4,4,5,5,5-heptafluoropentyl, 3,3,4,4,5,5,6,6,6-nonafluorohexyl, 3,3,4,4,5,5,6,6,7,7,7-undecafluoroheptyl, and 3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluorooctyl. Examples of silicon-bonded groups other than alkenyl and fluoroalkyl groups include alkyl groups having 1 to 12 carbon atoms, such as methyl, ethyl, propyl, butyl, and octyl. Examples include aryl groups having 6 to 12 carbon atoms, such as phenyl, tolyl, and xylyl; and aralkyl groups having 7 to 12 carbon atoms, such as benzyl and phenethyl. Among these, methyl is preferred. The content of fluorine atoms associated with fluoroalkyl groups per molecule is preferably at least 30%, or at least 35%, or at least 40% by weight, because when the content of fluorine atoms in component (A) is equal to or greater than the lower limit indicated above, the release coating obtained by crosslinking the composition exhibits good release strength against silicone pressure-sensitive adhesives.Although there is no particular upper limit to the content of fluorine atoms in component (A), if the content is too high, component (A) itself tends to be insoluble in the solvent, which reduces ease of handling. Therefore, the content is preferably at most 60% by mass or at most 50% by mass. A small amount of hydroxyl groups or alkoxy groups having 1 to 3 carbon atoms may be bonded to the silicon atoms in component (A) within a range that does not impair the object of the present invention.

[0028] Component (A) preferably has the general formula: R 1 3SiO 1 / 2 and M siloxane units represented by the general formula: R 1 2SiO 2 / 2 It is an organopolysiloxane consisting essentially of D siloxane units represented by the following formula:

[0029] In the formula, R 1 are the same or different and are an alkyl group having 1 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, or a fluoroalkyl group having 1 to 12 carbon atoms, examples of which are the same as those mentioned above. 1 is an alkenyl group, and at least one R 1 is a fluoroalkyl group.

[0030] The organopolysiloxane for component (A) may contain a small amount of other siloxane units, such as those represented by the general formula: (X)R 1 2SiO 1 / 2 The copolymer may contain M siloxane units represented by the formula: wherein X is a hydroxyl group or an alkoxy group having 1 to 3 carbon atoms.

[0031] <Component (B)> Component (B) is a branched organopolysiloxane containing at least one fluoroalkyl group per molecule and no silicon-bonded hydrogen atoms. Examples of fluoroalkyl groups include those described above, with 3,3,3-trifluoropropyl being preferred. Examples of silicon-bonded groups other than fluoroalkyl groups include alkyl groups having 1 to 12 carbon atoms, alkenyl groups having 2 to 12 carbon atoms, aryl groups having 6 to 12 carbon atoms, and aralkyl groups having 7 to 12 carbon atoms, with methyl and vinyl being preferred. The content of fluorine atoms associated with fluoroalkyl groups per molecule is preferably at least 15% by weight, or at least 20% by weight, or at least 25% by weight. This is because when the fluorine atom content in component (B) is equal to or greater than the lower limit described above, the release coating obtained by crosslinking this composition exhibits good release strength against silicone pressure-sensitive adhesives. Although there is no particular upper limit for the content of fluorine atoms in component (B), if the content is too high, component (B) itself tends to be insoluble in the solvent, which reduces ease of handling. Therefore, the content is preferably at most 60% by mass or at most 50% by mass. A small amount of hydroxyl or alkoxy groups may be bonded to the silicon atoms in component (B) within a range that does not impair the object of the present invention.

[0032] Component (B) preferably has the general formula: R 2 3SiO 1 / 2 M siloxane units represented by the general formula: R 2 2SiO 2 / 2 D siloxane units represented by the formula: SiO 4 / 2 The organopolysiloxane is essentially composed of Q siloxane units represented by the formula:

[0033] In the formula, R 2are the same or different and are an alkyl group having 1 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, or a fluoroalkyl group having 1 to 12 carbon atoms, examples of which are the same as those described above. 2 is a fluoroalkyl group.

[0034] The organopolysiloxane of component (B) may contain a small amount of other siloxane units, such as those represented by the general formula: (X)R 2 2SiO 1 / 2 M siloxane units represented by the general formula: R 2 SiO 3 / 2 The copolymer may contain T siloxane units represented by the formula: wherein X is a hydroxyl group or an alkoxy group having 1 to 3 carbon atoms.

[0035] The viscosity of component (B) at 25°C is not limited, but in various embodiments, it is in the range of about 100 mPa·s to about 100,000 mPa·s, or about 200 mPa·s to about 50,000 mPa·s, or about 300 mPa·s to about 50,000 mPa·s. This is because, when the viscosity of component (B) is at or above the lower limit of the above range, the resulting release coating has sufficient characteristics, while, when the viscosity is at or below the upper limit of the above range, the resulting composition has a viscosity suitable for processing and handling. In this specification, viscosity is measured at 23±2°C using a Brookfield viscometer in accordance with ASTM D 1084.

[0036] <Component (C)> Component (C) is a linear organopolysiloxane having at least one fluoroalkyl group per molecule and no aliphatic unsaturated groups or silicon-bonded hydrogen atoms. Examples of the fluoroalkyl group include those listed above, with 3,3,4,4,5,5,5-heptafluoropentyl, 3,3,4,4,5,5,6,6,6-nonafluorohexyl, 3,3,4,4,5,5,6,6,7,7,7-undecafluoroheptyl, and 3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluorooctyl being preferred. Examples of silicon-bonded groups other than fluoroalkyl groups include alkyl groups having 1 to 12 carbon atoms, aryl groups having 6 to 12 carbon atoms, and aralkyl groups having 7 to 12 carbon atoms. Examples of these groups are the same as those listed above, with methyl being preferred. The content of fluorine atoms associated with fluoroalkyl groups per molecule is preferably at least 20% by weight, or at least 25% by weight, or at least 30% by weight. This is because when the fluorine atom content in component (C) is equal to or greater than the above-mentioned lower limit, the release coating obtained by crosslinking the composition exhibits good release strength against silicone pressure-sensitive adhesives. While there is no particular upper limit for the fluorine atom content in component (C), if the content is too high, component (C) itself tends to be insoluble in solvents, thereby reducing ease of handling. Therefore, the content is preferably at most 60% by weight, or at most 50% by weight. A small number of hydroxyl groups or alkoxy groups having 1 to 3 carbon atoms may be bonded to the silicon atoms in component (C), provided that the objectives of the present invention are not impaired.

[0037] Component (C) preferably has the general formula: R 3 3SiO 1 / 2 and M siloxane units represented by the general formula: R 3 2SiO 2 / 2 It is an organopolysiloxane consisting essentially of D siloxane units represented by the following formula:

[0038] In the formula, R 3are the same or different and are an alkyl group having 1 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, or a fluoroalkyl group having 1 to 12 carbon atoms, examples of which are the same as those described above. 3 is a fluoroalkyl group.

[0039] The organopolysiloxane for component (C) may contain a small amount of other siloxane units, such as those represented by the general formula: (X)R 3 2SiO 1 / 2 The copolymer may contain M siloxane units represented by the formula: wherein X is a hydroxyl group or an alkoxy group having 1 to 3 carbon atoms.

[0040] The viscosity of component (C) at 25°C is not limited, but in various embodiments, it is in the range of about 1,000 mPa·s to about 100,000 mPa·s, alternatively about 2,000 mPa·s to about 100,000 mPa·s, or alternatively about 3,000 mPa·s to about 100,000 mPa·s. This is because when the viscosity of component (C) is at or above the lower limit of the above range, the resulting release coating has sufficient characteristics, while when the viscosity is at or below the upper limit of the above range, the resulting composition has a viscosity suitable for processing and handling. In this specification, viscosity is measured at 23±2°C using a Brookfield viscometer in accordance with ASTM D 1084.

[0041] Based on the total mass of components (A) to (C), the content of component (A) is in the range of 40 to 90.5 mass%, the content of component (B) is in the range of 9 to 56 mass%, and the content of component (C) is in the range of 0.5 to 4 mass%. Preferably, the content of component (A) is in the range of 40 to 85.5 mass%, the content of component (B) is in the range of 14 to 56 mass%, and the content of component (C) is in the range of 0.5 to 4 mass%, or the content of component (A) is in the range of 40 to 80.5 mass%, the content of component (B) is in the range of 19 to 56 mass%, and the content of component (C) is in the range of 0.5 to 4 mass%. This is because, when the content of component (A) is above the lower limit of the above range, the release force of the resulting release coating tends to be stable, while when the content is below the upper limit of the above range, the comparability of component (A) tends to be improved. On the other hand, when the content of component (B) is above the lower limit of the above range, the release force of the resulting release coating during wet coating tends to be good and the release force over time tends to be stable, while when it is below the upper limit of the above range, the comparability of component (B) tends to be improved. On the other hand, when the content of component (C) is above the lower limit of the above range, the release force of the resulting release coating tends to be stable, while when it is below the upper limit of the above range, the release force of the resulting release coating tends to be stable and the release force over time also tends to be stable.

[0042] <Component (D)> Component (D) is an organohydrogenpolysiloxane having at least two silicon-bonded hydrogen atoms per molecule. Examples of the groups bonded to silicon atoms in component (D) include alkyl groups having 1 to 12 carbon atoms, aryl groups having 6 to 12 carbon atoms, aralkyl groups having 7 to 12 carbon atoms, and fluoroalkyl groups having 1 to 12 carbon atoms. Examples of these groups are the same as those described above. Among these, methyl, 3,3,4,4,5,5,5-heptafluoropentyl, 3,3,4,4,5,5,6,6,6-nonafluorohexyl, 3,3,4,4,5,5,6,6,7,7,7-undecafluoroheptyl, and 3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluorooctyl are preferred. The content of fluorine atoms associated with fluoroalkyl groups per molecule is not particularly limited, but is preferably at least 20%, at least 25%, at least 30%, or at least 35% by weight. This is because a fluorine atom content in component (D) above the lower limit improves compatibility with components (A) to (C), and the release coating obtained by crosslinking the composition exhibits good release strength against silicone pressure-sensitive adhesives. While there is no particular upper limit for the fluorine atom content in component (D), if the content is too high, component (D) itself tends to be insoluble in solvents, reducing ease of handling. Therefore, the content is preferably at most 60% or at most 50% by weight. A small number of hydroxyl groups or alkoxy groups having 1 to 3 carbon atoms may be bonded to the silicon atoms in component (D), provided that the objectives of the present invention are not impaired.

[0043] The molecular structure of component (D) is not particularly limited, and may be, for example, linear, branched, partially branched linear, resinous, or cyclic, with linear or partially branched linear being preferred.

[0044] The content of component (D) is in the range of about 1 to about 15 parts by weight, preferably about 1 to about 13 parts by weight, alternatively about 2 to about 15 parts by weight, alternatively about 3 to about 15 parts by weight, alternatively about 2 to about 13 parts by weight, or alternatively about 3 to about 13 parts by weight, per 100 parts by weight of the total weight of components (A) to (C). This is because, when the content of component (D) is at or above the lower limit of the above range, crosslinking of the composition proceeds sufficiently, whereas, when the content is at or below the upper limit of the above range, the characteristics of the resulting release coating are stabilized.

[0045] <Component (E)> Component (E) is a hydrosilylation catalyst for accelerating the curing of the composition. Examples of such catalysts include platinum-based catalysts, rhodium-based catalysts, and palladium-based catalysts, with platinum-based catalysts being preferred. Examples of platinum-based catalysts include platinum fine powder, platinum black, platinum-supported silica fine powder, platinum-supported activated carbon, chloroplatinic acid, alcohol solutions of chloroplatinic acid, platinum-olefin complexes, and platinum-alkenylsiloxane complexes.

[0046] The content of component (E) is an amount effective to promote the curing of the composition, specifically, an amount such that the platinum atoms in the catalyst are in the range of about 0.1 to 1000 ppm by mass relative to the composition. This is because, if the content of component (E) is above the lower limit of the above range, the curing of the resulting composition proceeds, whereas, if the content is below the upper limit of the above range, the resulting cured product is less likely to discolor.

[0047] <Component (F)> The composition may also contain (F) a hydrosilylation reaction inhibitor to control the crosslinking reaction. Examples of component (F) include alkyne alcohols such as 1-ethynylcyclohexan-1-ol, 2-methyl-3-butyn-2-ol, 3,5-dimethyl-1-hexyn-3-ol, and 2-phenyl-3-butyn-2-ol; enyne compounds such as 3-methyl-3-penten-1-yne and 3,5-dimethyl-3-hexen-1-yne; methylalkenylsiloxane oligomers such as 1,3,5,7-tetramethyl-1,3,5,7-tetravinylcyclotetrasiloxane and 1,3,5,7-tetramethyl-1,3,5,7-tetrahexenylcyclotetrasiloxane; dimethylbis(3-methyl-1-butyn-3-oxy)silane and methylvinylbis(3-methyl-1-butyn-3-oxy)silane. alkyneoxysilanes such as methyltris(1-methyl-1-phenyl-propyneoxy)silane, dimethylbis(1-methyl-1-phenyl-propyneoxy)silane, methyltris(1,1-dimethyl-propyneoxy)silane, dimethylbis(1,1-dimethyl-propyneoxy)silane, and other alkeneoxysilane compounds; triazoles, phosphines, mercaptans, hydrazines, sulfoxides, phosphates, nitriles, hydroperoxides, amines, ethylenically unsaturated isocyanates, fumarates (e.g., dialkyl fumarates, dialkenyl fumarates, and / or dialkoxyalkyl fumarates), maleates (e.g., diallyl maleate), alkenes, and combinations thereof.

[0048] The content of component (F) is not limited, but from the viewpoint of imparting a sufficient pot life to the composition, it is preferably in the range of about 0.01 to about 5 parts by mass, or about 0.05 to about 5 parts by mass, or about 0.05 to about 3 parts by mass, per 100 parts by mass of the total mass of components (A) to (C). This is because, when the content of component (F) is at or above the lower limit of the above range, the pot life of the composition is sufficient for practical use, and, when it is at or below the upper limit of the above range, the curability of the composition is good for practical use.

[0049] <Component (G)> In addition, the present composition may contain a (G) solvent to reduce its viscosity and improve application workability and wetting. Examples of component (G) include aromatic hydrocarbon solvents such as toluene and xylene, aliphatic hydrocarbon solvents such as hexane, heptane, octane, isooctane, decane, cyclohexane, methylcyclohexane, and isoparaffin, hydrocarbon solvents such as industrial gasoline (e.g., rubber solvent), petroleum benzine, and solvent naphtha; ketone solvents such as acetone, methyl ethyl ketone, 2-pentanone, 3-pentanone, 2-hexanone, 2-heptanone, 4-heptanone, methyl isobutyl ketone, diisobutyl ketone, acetonylacetone, and cyclohexanone; ester solvents such as ethyl acetate, propyl acetate, isopropyl acetate, butyl acetate, and isobutyl acetate; diethyl ether, dipropyl ether, diisopropyl ether, and dibutyl ether. Examples of suitable solvents include ether-based solvents such as 2-methoxyethyl acetate, 2-ethoxyethyl acetate, propylene glycol monoether acetate, and 2-butoxyethyl acetate; solvents having ester and ether components such as hexamethyldisiloxane, octamethyltrisiloxane, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, tris(trimethylsiloxy)methylsilane, and tetrakis(trimethylsiloxy)silane; fluorine-based solvents such as trifluorotoluene, hexafluoroxylene, methyl nonafluorobutyl ether, and ethyl nonafluorobutyl ether; and mixed solvents of two or more of these.

[0050] The content of component (G) is optional and may be adjusted as needed, but the content is typically about 2,000 parts by mass or less per 100 parts by mass of the total mass of components (A) to (C).

[0051] The present composition may contain antioxidants, reactive diluents, leveling agents, fillers, antistatic agents, antifoaming agents, pigments, etc., within the scope of the present invention.

[0052] <Release liner> Next, the release liner of the present invention will be described in detail.

[0053] The release liner can be made by applying the composition to a substrate and allowing the composition to cure.

[0054] Examples of substrates include paper, plastic film, glass, and metal film. Examples of paper include fine paper, coated paper, art paper, glassine paper, polyethylene-laminated paper, and kraft paper. Examples of plastic films include polyethylene film, polypropylene film, polyester film, polyimide film, polyvinyl chloride film, polyvinylidene chloride film, polyvinyl alcohol film, polycarbonate film, polytetrafluoroethylene film, polystyrene film, ethylene-vinyl acetate copolymer film, ethylene-vinyl alcohol copolymer film, triacetyl cellulose film, polyether ether ketone film, and polyphenylene sulfide film. The thickness and type of glass are not particularly limited, and the glass may be chemically strengthened. In addition, glass fiber may be applied, or the glass fiber may be used alone or in combination with another resin. Examples of metals include aluminum foil, copper foil, gold foil, silver foil, and nickel foil. When used as a release film, polyester film is preferred.

[0055] The method for applying the composition to a substrate is not limited, and any known coating method can be used, including, for example, a wire bar coater, a comma coater, a lip coater, a roll coater, a die coater, a knife coater, a blade coater, a rod coater, a kiss coater, a gravure coater, a screen coater, a dip coater, and a cast coater.

[0056] The amount of the present composition to be applied to the substrate is not limited, but is preferably about 0.1 to about 2 g / m in terms of solid content. 2Within the range of about 0.2 to about 1.8 g / m 2 The curing conditions are not limited, but the composition is preferably heated within a range of about 80 to about 180°C or within a range of about 90 to about 160°C for about 10 to about 180 seconds or within a range of about 15 to about 150 seconds.

[0057] A silicone pressure-sensitive adhesive may be applied to the release liner thus produced. As the silicone pressure-sensitive adhesive composition, a commercially available composition may be used.

[0058] The method for applying the silicone pressure-sensitive adhesive composition can be any known coating method, examples of which include a comma coater, lip coater, roll coater, die coater, knife coater, blade coater, rod coater, kiss coater, gravure coater, screen coating, dip coating, cast coating, and the like.

[0059] The amount of silicone pressure-sensitive adhesive applied may be such that the thickness after curing is about 0.1 to about 300 μm, preferably about 0.5 to about 200 μm. In addition, in measuring the peel strength, the silicone pressure-sensitive adhesive composition may be cured at about 80 to about 150°C for about 10 seconds to about 10 minutes. [Example]

[0060] The fluorosilicone release coating composition and release liner of the present invention will be described in more detail below using examples and comparative examples, but the present invention is not limited to the following examples. In the formula, Me is methyl, Vi is a vinyl group, P is a methyl group, f1 is a 3,3,4,4,5,5,6,6,6-nonafluorohexyl group, P f2 is a 3,3,3-trifluoropropyl group. The viscosity of the organopolysiloxane was measured as follows.

[0061] <Viscosity> The viscosity was measured at 23±2° C. using a Brookfield HA or HB type rotational viscometer (using a spindle #52 at 5 rpm) in accordance with ASTM D 1084 "Standard Test Methods for Viscosity of Adhesives."

[0062] <Example 1 and Comparative Examples 1 to 3> The fluorosilicone release coating compositions shown in Table 1 were prepared using the following components. First, components (A), (B), (C), and (F) were mixed to homogeneity, and a suitable solvent (component (G)), such as isopropyl ether, heptane, a fluorinated solvent, or a mixture thereof, was added to adjust the nonvolatile content. Next, components (D) and (E) were added to produce the fluorosilicone release coating compositions. The nonvolatile content of each of the fluorosilicone release coating compositions was adjusted to 9% by weight. The compositions were coated onto PET substrates using a coater and then cured at 140°C for 30 seconds. The performance of the compositions is also shown in Table 2.

[0063] The following components were used as component (A): Component (a-1): Me2SiO 2 / 2 , MeR f1 SiO 2 / 2 , ViMeSiO 2 / 2 , and ViMe2SiO 1 / 2 units and having a vinyl group content of 0.16% by mass and a fluorine atom content of 42.1% by mass. Component (a-2): Me2SiO 2 / 2 , MeR f1 SiO 2 / 2 , ViMeSiO 2 / 2 , and MeSiO 1 / 2 units and having a vinyl group content of 0.20% by mass and a fluorine atom content of 41.9% by mass.

[0064] The following components were used as component (B): Constituent (b-1): SiO 4 / 2 , Me2SiO 2 / 2 , MeR f2 SiO 2 / 2 , Me3SiO 1 / 2 , and ViMe2SiO 1 / 2 units and having a viscosity of about 500 mPa·s, a vinyl group content of 0.44% by mass, and a fluorine atom content of 26% by mass.

[0065] The following components were used as component (C): Constituent (c-1): Me2SiO 2 / 2 , MeR f1 SiO 2 / 2 , and MeSiO 1 / 2 and having a viscosity of 66,000 mPa·s and a fluorine atom content of 32.4 mass%.

[0066] The following components were used as component (D): Component (d-1): MeHSiO 2 / 2 , MeR f1 SiO 2 / 2 , and MeSiO 1 / 2 and having a viscosity of 66,000 mPa·s, a fluorine atom content of 38 mass %, and a silicon atom-bonded hydrogen atom content of 0.50 mass %.

[0067] The following components were used as component (E): Component (e-1): 1.5 mass% Pt-1,3-divinyl-1,1,3,3-tetramethyldisiloxane complex in dimethylvinylsiloxy-terminated dimethylpolysiloxane with a viscosity of 450 mPa·s

[0068] The following components were used as component (F): Component (f-1): 3-methyl-1-butyn-2-ol Component (f-2): Diallyl maleate

[0069]

Table 1

[0070] <si-psa> The following silicone pressure sensitive adhesives were used to evaluate the fluorosilicone release coating compositions of the examples and comparative examples. Si-PSA 1: A silicone pressure sensitive adhesive with a glass transition temperature of -11°C. Si-PSA 2: A silicone pressure sensitive adhesive with a glass transition temperature of -18°C. Si-PSA 3: A silicone pressure sensitive adhesive with a glass transition temperature of 30°C.

[0071] <Measurement of peel force (a)> Dry Laminate: The cured Si-PSA1 or Si-PSA2 tape was laminated onto the coated release coating, and 20 g / cm was applied to the laminate sample. 2 The test piece was then placed under a weight of 100g and left at room temperature (RT) or 70°C for 20 hours or 3 days. After 20 hours or 3 days, the load was removed and the test piece was left for 30 minutes. The peel strength of the liner side was then tested using a ChemInstruments AR-1500. Refer to FINAT Test Method No. 10 (FINAT Technical Handbook 7th edition, 2005).

[0072] <Measurement of peel force (b)> Wet coating: Si-PSA was coated directly onto the coated release liner, cured, and blank PET was laminated onto the PSA surface and then cut to 1 inch width. 20 g / cm2 was applied to the laminated sample. 2 The test piece was then left at room temperature or 70°C for 20 hours or 3 days. After 20 hours or 3 days, the test piece was removed and left for 30 minutes. The peel strength of the liner side was then tested using a ChemInstruments AR-1500. Refer to FINAT Test Method No. 10 (FINAT Technical Handbook 7th edition, 2005).

[0073] [Table 2]

[0074] Industrial Applicability The fluorosilicone release coating composition of the present invention is capable of forming a release coating that exhibits low release force for Si-PSAs having low glass transition temperatures, and is therefore effective as an F-Si release coating composition for producing release liners for Si-PSAs for protecting OCAs. The present invention can provide the following aspects. [1] 1. A fluorosilicone release coating composition comprising: (A) a linear organopolysiloxane having at least two alkenyl groups and at least one fluoroalkyl group per molecule and having no silicon-bonded hydrogen atoms; (B) a branched organopolysiloxane having at least one fluoroalkyl group per molecule and no silicon-bonded hydrogen atoms; (C) a linear organopolysiloxane having at least one fluoroalkyl group per molecule and having neither an aliphatic unsaturated group nor a silicon-bonded hydrogen atom; (D) an organohydrogenpolysiloxane having at least two silicon-bonded hydrogen atoms and at least one fluoroalkyl group per molecule; (E) an effective amount of a hydrosilylation reaction catalyst; A fluorosilicone release coating composition, wherein, based on the total mass of components (A) to (C), the content of component (A) is in the range of about 40 to about 90.5 mass %, the content of component (B) is in the range of about 9 to about 56 mass %, the content of component (C) is in the range of about 0.5 to about 4 mass %, and the content of component (D) is in the range of about 1 to about 15 mass parts per 100 mass parts of the total mass of components (A) to (C). [2] Component (A) is a fluorosilicone release coating composition according to the above item [1], which contains the fluoroalkyl groups in an amount such that the content of fluorine atoms associated with the fluoroalkyl groups per molecule is at least 30% by weight. [3] Component (A) is a compound represented by the general formula: R 1 3 SiO 1 / 2 and M siloxane units represented by the general formula: R 1 2 SiO 2 / 2 is an organopolysiloxane consisting essentially of D siloxane units represented by the formula: 1 are the same or different and are an alkyl group having 1 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, or a fluoroalkyl group having 1 to 12 carbon atoms, provided that at least two R 1 is the alkenyl group, and at least one R 1 is the fluoroalkyl group. [4] Component (B) is a fluorosilicone release coating composition according to item [1] above, which contains fluoroalkyl groups in an amount such that the content of fluorine atoms associated with said fluoroalkyl groups per molecule is at least 15% by weight. [5] Component (B) is a compound represented by the general formula: R 2 3 SiO 1 / 2 M siloxane units represented by the general formula: R 2 2 SiO 2 / 2 D siloxane units represented by the general formula: SiO 4 / 2 wherein R 2 are the same or different and are an alkyl group having 1 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, or a fluoroalkyl group having 1 to 12 carbon atoms, provided that at least one R 2 is the fluoroalkyl group. [6] Component (C) is a fluorosilicone release coating composition according to item [1] above, wherein the fluoroalkyl groups are present in an amount such that the content of fluorine atoms associated with the fluoroalkyl groups per molecule is at least 20% by weight. [7] The component (C) is a compound represented by the general formula: R 3 3 SiO 1 / 2 and M siloxane units represented by the general formula: R 3 2 SiO 2 / 2 is an organopolysiloxane consisting essentially of D siloxane units represented by the formula: 3 are the same or different and are an alkyl group having 1 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, or a fluoroalkyl group having 1 to 12 carbon atoms, provided that at least one R 3 is the fluoroalkyl group. [8] The fluorosilicone release coating composition according to item [1] above, further comprising (F) a hydrosilylation reaction inhibitor in an amount of about 0.01 to about 5 parts by weight per 100 parts by weight of the total weight of components (A) to (C). [9] (G) The fluorosilicone release coating composition according to [1] above, further comprising an optional amount of a solvent.

[10] The fluorosilicone release coating composition according to [1] above, which is used for silicone pressure sensitive adhesives.

[11] A release liner obtained by coating a substrate with the fluorosilicone release coating composition according to any one of the above [1] to [9].

[12] The release liner according to

[11] above, wherein the substrate is a plastic film.

Claims

1. 1. A fluorosilicone release coating composition comprising: (A) a linear organopolysiloxane having at least two alkenyl groups and at least one fluoroalkyl group per molecule and having no silicon-bonded hydrogen atoms; (B) a branched organopolysiloxane having at least one fluoroalkyl group per molecule, having no silicon-bonded hydrogen atoms, and having, as a silicon-bonded group, an alkenyl group having from 2 to 12 carbon atoms; (C) a linear organopolysiloxane having at least one fluoroalkyl group per molecule and having neither an aliphatic unsaturated group nor a silicon-bonded hydrogen atom; (D) an organohydrogenpolysiloxane having at least two silicon-bonded hydrogen atoms and at least one fluoroalkyl group per molecule; (E) an effective amount of a hydrosilylation reaction catalyst; The content of component (A) is in the range of 40 to 90.5 mass%, the content of component (B) is in the range of 9 to 56 mass%, the content of component (C) is in the range of 0.5 to 4 mass%, and the content of component (D) is in the range of 1 to 15 parts by mass, based on the total mass of components (A) to (C), respectively; component (A) has the fluoroalkyl groups in an amount such that the content of fluorine atoms associated with the fluoroalkyl groups in one molecule is at least 30% by mass and at most 60% by mass; component (B) has the fluoroalkyl groups in an amount such that the content of fluorine atoms associated with the fluoroalkyl groups in one molecule is at least 15% by mass and at most 60% by mass; component (C) has the fluoroalkyl groups in an amount such that the content of fluorine atoms associated with the fluoroalkyl groups in one molecule is at least 20% by mass and at most 60% by mass; Component (D) is a fluorosilicone release coating composition having fluoroalkyl groups in an amount such that the content of fluorine atoms associated with said fluoroalkyl groups per molecule is at least 20% and at most 60% by weight.

2. The component (A) is a compound represented by the general formula: R １ ３ SiO １／２ and M siloxane units represented by the general formula: R １ ２ SiO ２／２ In the formula, R １ are the same or different and are an alkyl group having 1 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, or a fluoroalkyl group having 1 to 12 carbon atoms, provided that at least two R １ is the alkenyl group, and at least one R １ 10. The fluorosilicone release coating composition of claim 1, wherein is said fluoroalkyl group.

3. The component (B) is represented by the general formula: R ２ ３ SiO １／２ M siloxane units represented by the general formula: R ２ ２ SiO ２／２ D siloxane units represented by the general formula: SiO ４／２ In the formula, R ２ are the same or different and are an alkyl group having 1 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, or a fluoroalkyl group having 1 to 12 carbon atoms, provided that at least one R ２ 10. The fluorosilicone release coating composition of claim 1, wherein is said fluoroalkyl group.

4. The component (C) is a compound represented by the general formula: R ３ ３ SiO １／２ and M siloxane units represented by the general formula: R ３ ２ SiO ２／２ In the formula, R ３ are the same or different and are an alkyl group having 1 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, or a fluoroalkyl group having 1 to 12 carbon atoms, provided that at least one R ３ 10. The fluorosilicone release coating composition of claim 1, wherein is said fluoroalkyl group.

5. 10. The fluorosilicone release coating composition of claim 1, further comprising (F) a hydrosilylation reaction inhibitor in an amount of 0.01 to 5 parts by weight, based on 100 parts by weight of the total weight of components (A) through (C).

6. 10. The fluorosilicone release coating composition of claim 1 further comprising (G) an optional amount of a solvent.

7. 10. The fluorosilicone release coating composition of claim 1 used with a silicone pressure sensitive adhesive.

8. A release liner obtained by coating a substrate with the fluorosilicone release coating composition of any one of claims 1 to 6.

9. The release liner of claim 8 wherein the substrate is a plastic film.

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