Polysiloxane controlled release additive, method for preparing same, and release coating composition

Abstract

The polysiloxane is prepared by the hydrosilylation reaction of a polyorganosilicate resin with a SiH-terminated polydiorganosiloxane. When incorporated into a release coating composition, the polysiloxane acts as a controlled release additive. The release coating composition can be coated onto the surface of a substrate and cured to form a release liner.

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority under 35 U.S.C. §119(e) to U.S. Provisional Application No. 62 / 848,822, filed May 16, 2019. U.S. Provisional Application No. 62 / 84882 is incorporated herein by reference.

[0002] The polysiloxanes are useful as controlled release additives for release coating compositions that contain the polysiloxanes and can be coated on a substrate and cured to form a release liner with improved properties. [Background technology]

[0003] Silicone release coating compositions can be used to form release liners that can release adhesives.For example, silicone release coating compositions can be used to coat various substrates, such as paper or plastic films, to obtain release liners (e.g., labels or tapes) for laminating pressure-sensitive adhesives.Many silicone release coating compositions are hydrosilylation reaction curable. Summary of the Invention [Problem to be solved by the invention]

[0004] Conventional release liners can be formed by hydrosilylation reaction of release coating compositions containing polyorganosiloxanes and polyorganohydrogensiloxanes with aliphatic unsaturated hydrocarbon groups in the presence of a hydrosilylation reaction catalyst.However, the release force of conventional release liners is often undesirably low.For example, in hand peel applications, low release force often leads to undesirable label dispensing.

[0005] Polysiloxanes and methods for preparing the same are disclosed. The polysiloxanes are useful as controlled release additives. Release coating compositions containing the polysiloxanes are useful for forming release liners. The release liners include release coatings prepared by curing the release coating composition on the surface of a substrate. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0006] Polysiloxane Polysiloxanes are M, Q, and M U , and D L Contains siloxane units. In polysiloxanes: M is the formula [ka] represents the unit of Q is the formula [ka] represents the unit of M U is the formula [ka] represents the unit of D L is the formula [ka] The polysiloxane may optionally further comprise D units and / or silanol-functional units. D is the formula [ka] The silanol functional unit is represented by M OH and / or T OH It can be a unit. M OH is the formula [ka] represents the unit of T OH is the formula [ka] Alternatively, polysiloxanes may be represented by the units M, Q, M U , D L and D units, optionally OH and / or T OH Alternatively, the polysiloxane may include M, Q, M U , D L and D units, optionally OH and / or T OH The polysiloxane contains sufficient M to provide a polysiloxane having a silanol content of 1.7% or less, alternatively 0.3% to 1.7%. OH and T OH It may have units.

[0007] In the above units, each R M is an independently selected monovalent hydrocarbon radical of 1 to 30 carbon atoms free of aliphatic unsaturation. Alternatively, each R M R may have 1 to 12 carbon atoms, alternatively 1 to 6 carbon atoms. M Suitable monovalent hydrocarbon groups for are exemplified by alkyl groups such as methyl, ethyl, propyl (e.g., iso-propyl and / or n-propyl), butyl (e.g., isobutyl, n-butyl, tert-butyl, and / or sec-butyl), pentyl (e.g., isopentyl, neopentyl, and / or tert-pentyl), hexyl, heptyl, octyl, nonyl, and decyl, as well as branched alkyl groups of six or more carbon atoms, cyclopentyl and cyclohexyl; aryl groups such as phenyl, tolyl, xylyl, and naphthyl; aralkyl groups such as benzyl and phenethyl. Alternatively, each R M may be alkyl or aryl. Alternatively, each R M may be alkyl. Alternatively, each R M may be methyl.

[0008] Each R U is an independently selected monovalent aliphatic unsaturated hydrocarbon group having 2 to 30 carbon atoms. Alternatively, each R U may have 2 to 12 carbon atoms, alternatively 2 to 6 carbon atoms. Suitable monovalent aliphatic unsaturated hydrocarbon groups include alkenyl and alkynyl groups. "Alkenyl" refers to a branched or unbranched monovalent hydrocarbon group having one or more carbon-carbon double bonds. Suitable alkenyl groups are exemplified by vinyl; allyl; propenyl (e.g., isopropenyl, and / or n-propenyl), as well as butenyl, pentenyl, hexenyl, and heptenyl (including branched and linear isomers of 4 to 7 carbon atoms); and cyclohexenyl. "Alkynyl" refers to a branched or unbranched monovalent hydrocarbon group having one or more carbon-carbon triple bonds. Suitable alkynyl groups are exemplified by ethynyl, propynyl, and butynyl (including branched and linear isomers of 2 to 4 carbon atoms). Alternatively, each R U may be an alkenyl such as vinyl, allyl, or hexenyl.

[0009] Each R D is an independently selected divalent hydrocarbon radical of 2 to 30 carbon atoms. Alternatively, each R D R may have 2 to 18 carbon atoms, alternatively 2 to 12 carbon atoms, alternatively 2 to 6 carbon atoms. D Suitable divalent hydrocarbon groups for are alkylene groups such as, for example, -(CH3)CH-, -CH2-CH2- (ethylene), propylene (including isopropylene and n-propylene), and butylene (including n-butylene, t-butylene, and isobutylene); and pentylene, hexylene, heptylene, and octylene, including branched and linear isomers of 5 to 8 carbon atoms; arylene groups such as phenylene, e.g., orthophenylene; and [ka] and the like. Alternatively, each divalent hydrocarbon group can be ethylene, propylene, butylene, or hexylene. Alternatively, each divalent hydrocarbon group can be ethylene or propylene.

[0010] Polysiloxanes have the formula M a Q b M U c D L d D e M OH q T OH r [In the formula, m, Q, M U , D L , D., M. OH , and T OH is as above, subscript a is ≧30, subscript b is ≧40, subscript c is ≧1, subscript d is ≧1, the number (c+d) is ≧1, subscript e is 0 to 20, subscript q is ≧0, and subscript r is ≧0, with the proviso that the number (q+r) is sufficient to provide a polysiloxane having a silanol content of 0 to 1.7%, alternatively 0.3% to 1.7%. Alternatively, subscript a may be 30 to 90, alternatively 35 to 90, alternatively 40 to 90. Alternatively, subscript b may be 40 to 120, alternatively 50 to 120. Alternatively, the number (c+d) may be 1 to 8, alternatively 3 to 16. Alternatively, subscript e may be 2 to 20, alternatively 2 to 18. Alternatively, the polysiloxane may have a unit formula M a Q b M U c D L d D e M OH q T OH r Alternatively, the polysiloxane may consist essentially of a unit of formula M a Q b M U c D L d D e M OH q TOH r It consists of:

[0011] Method for making polysiloxane The polysiloxane is 1) i) Unit formula (R M 3SiO 1 / 2 ) f (SiO 4 / 2 ) g (R U R M 2SiO 1 / 2 ) h wherein f≧30, subscript g≧40, and subscript h≧1; ii) Equation [ka] where the subscript i has a value of 0≦i≦20. and a SiH-terminated polydiorganosiloxane of iii) a hydrosilylation reaction catalyst, and optionally iv) combining starting materials comprising a solvent; combining starting materials ii) and i) in amounts sufficient to provide a molar ratio of SiH groups to silicon-bonded aliphatically unsaturated hydrocarbon groups (SiH:Vi ratio) of 0.2:1 to 0.7:1; The starting materials can be combined by any convenient means, such as mixing. One or more of the starting materials, e.g., i) the polyorganosilicate resin, iii) the hydrosilylation reaction catalyst, or both, can be dissolved in iv) a solvent to facilitate mixing. Starting materials i), iii) and iv) can be combined and heated, e.g., at 25°C to 150°C, and then starting material ii) can be added, e.g., by metering to control the exothermic reaction.

[0012] Starting Materials i) Polyorganosilicate Resins The polyorganosilicate resin used as starting material i) in the process for preparing the polysiloxane has the unit formula: f Q g M U h [Wherein, M, Q, and M U The units are as above, including subscript f≧30, subscript g≧40, and subscript h≧1. Alternatively, subscript f can be 30-45, alternatively 35-45, alternatively 35-40, alternatively 40-45. Alternatively, subscript g can be 40-60, alternatively 50-60, alternatively 55-60. Alternatively, subscript h can be 1-11, alternatively 1-8, alternatively 3-8, alternatively 4-6. The polyorganosilicate resin comprises an amount of M sufficient to provide no more than 2%, alternatively no more than 1.7%, alternatively no more than 1.3%, alternatively 0.3%-1.7% silanol groups. OH and / or T OH It may further include units, M OH and T OH The units are as above. The concentration of silanol groups present in the polyorganosiloxane can be measured using FTIR spectroscopy according to ASTM standard E-168-16. Suitable polyorganosilicate resins for use as starting material i) and their preparation methods are known in the art, for example in U.S. Pat. No. 9,732,191. Suitable polyorganosilicate resins for starting material i) are commercially available, such as DOWSIL™ 6-3444 INT from Dow Silicones Corporation (Midland, Michigan, USA).

[0013] Starting Material ii) SiH-Terminated Polydiorganosiloxane The starting material ii) is a compound of formula [ka] [In the formula, the group R Mis as above, with the subscript i being 0-20, alternatively 0-18, alternatively 2-18. Examples of suitable SiH-terminated polydiorganosiloxanes include SiH-terminated polydimethylsiloxanes, SiH-terminated poly(dimethyl / methylphenyl)siloxanes, SiH-terminated polymethylphenylsiloxanes, and combinations thereof. SiH-terminated polydiorganosiloxanes are commercially available, for example, hydride-terminated polydimethylsiloxanes, such as DMS-H03 and DMS-H05, from Gelest Inc., Morrisville, Pennsylvania, USA. SiH-terminated polymethylphenylsiloxanes, such as PMS-H03, are also commercially available from Gelest. 1,1,3,3-tetramethyldisiloxane is commercially available as DOWSIL™ 3-7010 INTERMEDIATE from Dow Silicones Corporation. DOWSIL™ Q2-5057S is a SiH-terminated polydimethylsiloxane also commercially available from Dow Silicones Corporation. Starting materials i) and ii) may be present in amounts sufficient to provide a SiH:Vi ratio of 0.2:1 to 0.7:1, alternatively 0.2:1 to 0.5:1.

[0014] Starting material (iii) hydrosilylation catalyst Hydrosilylation catalysts are known in the art and are commercially available. Hydrosilylation catalysts include platinum group metal catalysts. Such hydrosilylation catalysts can be metals selected from platinum, rhodium, ruthenium, palladium, osmium, and iridium. Alternatively, hydrosilylation catalysts can be compounds of such metals, such as chloride tris(triphenylphosphane)rhodium(I) (Wilkinson's catalyst), rhodium diphosphine chelates, such as [1,2-bis(diphenylphosphino)ethane]dichlorodirhodium or [1,2-bis(diethylphosphino)ethane]dichlorodirhodium, chloroplatinic acid (Speier's catalyst), chloroplatinic acid hexahydrate, platinum dichloride, and complexes of such compounds with low molecular weight organopolysiloxanes or platinum compounds, microencapsulated in matrix or core-shell structure. Complexes of platinum with low molecular weight organopolysiloxanes include platinum complexes of 1,3-diethenyl-1,1,3,3-tetramethyldisiloxane (Karstedt's catalyst). These complexes may be microencapsulated in a resin matrix. Alternatively, the hydrosilylation reaction catalyst may include platinum complexes of 1,3-diethenyl-1,1,3,3-tetramethyldisiloxane. Exemplary hydrosilylation catalysts are described in U.S. Patent Nos. 3,159,601, 3,220,972, 3,296,291, 3,419,593, 3,516,946, 3,814,730, 3,989,668, 4,784,879, 5,036,117, and 5,175,325, and in European Patent No. 0347895(B). Microencapsulated hydrosilylation catalysts and methods for their preparation are known in the art, as exemplified in U.S. Patent Nos. 4,766,176 and 5,017,654. Hydrosilylation reaction catalysts are commercially available, for example, SYL-OFF™ 4000 Catalyst and SYL-OFF™ 2700 are available from Dow Silicones Corporation.

[0015] The amount of hydrosilylation reaction catalyst used herein will vary depending on a variety of factors, including the selection of starting materials i) and ii) and their respective contents of silicon-bonded hydrogen atoms and aliphatically unsaturated groups, and the content of platinum group metal in the catalyst selected as starting material iii), but the amount of hydrosilylation reaction catalyst is sufficient to catalyze the hydrosilylation reaction of SiH with aliphatically unsaturated groups, or the amount of catalyst is sufficient to provide from 1 ppm to 1000 ppm of platinum group metal, based on the combined weight of starting materials i), ii), and iii), or sufficient to provide from 1 ppm to 100 ppm of platinum group metal under the same basis.

[0016] Starting material iv) Solvent Starting material iv) is a solvent. Suitable solvents include organic liquids exemplified by, but not limited to, aromatic hydrocarbons, aliphatic hydrocarbons, alcohols, aldehydes, ketones, amines, esters, ethers, glycols, glycol ethers, alkyl halides, and aromatic halides. Hydrocarbons include benzene, toluene, xylene, hexane, heptane, octane, isododecane, isohexadecane, Isopar L (C11-C13), Isopar H (C11-C12), hydrogenated polydecene. Suitable alcohols include, but are not limited to, methanol, ethanol, isopropanol, butanol, or n-propanol. Suitable ketones include, but are not limited to, acetone, methyl ethyl ketone, or methyl isobutyl ketone. The ethers and esters include isodecyl neopentanoate, neopentyl glycol heptanoate, glycol distearate, dicaprylyl carbonate, diethylhexyl carbonate, propylene glycol n-propyl ether, propylene glycol-n-butyl ether, ethyl-3 ethoxypropionate, propylene glycol methyl ether acetate, tridecyl neopentanoate, propylene glycol methyl ether acetate (PGMEA), propylene glycol methyl ether (PGME), dipropylene glycol methyl ether, or ethylene glycol n-butyl ether, octyldodecyl neopentanoate, diisobutyl adipate, diisopropyl adipate, propylene glycol dicaprylate / dicaprate, octyl ether, and octyl palmitate. Alternatively, the solvent may be selected from polyalkylsiloxanes, alcohols, ketones, glycol ethers, tetrahydrofuran, mineral spirits, naphtha, tetrahydrofuran, mineral spirits, naphtha, or combinations thereof.Polyalkylsiloxanes having suitable vapor pressures can be used as solvents, including hexamethyldisiloxane, octamethyltrisiloxane, hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, dodecamethylcyclohexasiloxane, octamethyltrisiloxane, decamethyltetrasiloxane, dodecamethylpentasiloxane, tetradecamethylhexasiloxane, hexadecamethylheptasiloxane, heptamethyl-3-{(trimethylsilyl)oxy}trisiloxane, hexamethyl-3,3,bis{(trimethylsilyl)oxy}trisiloxane pentamethyl{(trimethylsilyl)oxy}cyclotrisiloxane, and combinations thereof. Low molecular weight polyalkylsiloxanes, such as 0.5 to 1.5 cSt polydimethylsiloxanes, are known in the art and are commercially available as DOWSIL™ 200 Fluids and DOWSIL™ OS FLUIDS, available from Dow Silicones Corporation.

[0017] However, the amount of solvent will vary depending on various factors, such as the type of solvent selected, as well as the amount and type of other starting materials selected. The amount of solvent can be 0% to 99% by weight, alternatively 0% to 98% by weight, alternatively 0% to 70% by weight, alternatively 2% to 50% by weight, based on the weight of all starting materials used in the method of preparing the polysiloxane. Solvents can be added during the preparation of the polysiloxane, for example, to aid in mixing and delivery. Certain starting materials, such as i) the polyorganosilicate resin and / or iii) the hydrosilylation reaction catalyst, can be delivered in a solvent.

[0018] Release Coating Composition The above polysiloxanes are useful in release coating compositions. The release coating compositions include (A) the polysiloxane described above; (B) a polyorganohydrogensiloxane having at least two silicon-bonded hydrogen atoms per molecule; and (C) a hydrosilylation reaction catalyst; (D) a polyorganosiloxane having at least two silicon-bonded aliphatic unsaturated groups per molecule; Includes.

[0019] The release coating may optionally further comprise one or more additional starting materials, which may be selected from the group consisting of (E) a solvent, (F) a hydrosilylation reaction inhibitor, (G) an anchor additive, (H) an anti-mist additive, and (I) two or more of (E), (F), (G), and (H).

[0020] Starting material (B) The starting material (B) in the release coating composition is a polyorganohydrogensiloxane having an average of at least two silicon-bonded hydrogen atoms per molecule. Alternatively, the polyorganohydrogensiloxane may have at least three silicon-bonded hydrogen atoms per molecule. The silicon-bonded hydrogen atoms may be present at terminal, pendant, or both terminal and pendant positions on the polyorganohydrogensiloxane. The polyorganohydrogensiloxane may contain the following siloxy units containing silicon-bonded hydrogen atoms: (R 5 2HSiO 1 / 2 ), (R 5 H2SiO 1 / 2 ), (HSiO 1 / 2 ), (R 5 HSiO 2 / 2 ), (HSiO 2 / 2 ), and / or (HSiO 3 / 2 )(In the formula, each R 5 are independently a monovalent hydrocarbon group or a monovalent halogenated hydrocarbon group), optionally in combination with siloxy units that do not contain any silicon-bonded hydrogen atoms.

[0021] Each R 5are independently selected monovalent hydrocarbon or monovalent halogenated hydrocarbon groups, as described above, which may be linear, branched, cyclic, or combinations thereof. Cyclic hydrocarbon groups include aryl groups, as well as saturated or non-conjugated cyclic groups. Aryl groups may be monocyclic or polycyclic. Linear and branched hydrocarbon groups may be independently saturated or unsaturated. Suitable monovalent hydrocarbon groups are those represented by R M and R U As described above for R, R may be exemplified by alkyl, alkenyl, alkynyl, aryl, and aralkyl groups. Suitable monovalent halogenated hydrocarbon groups are exemplified by halogenated alkyl groups such as 3-chloropropyl, 2-bromoethyl, fluoromethyl, 2-fluoropropyl, and 3,3,3-trifluoropropyl, 4,4,4-trifluorobutyl, 4,4,4,3,3-pentafluorobutyl, 5,5,5,4,4,3,3-heptafluoropentyl, 6,6,6,5,5,4,4,3,3-nonafluorohexyl, and 8,8,8,7,7-pentafluorooctyl, 2,2-difluorocyclopropyl, 2,3-difluorocyclobutyl, 3,4-difluorocyclohexyl, and 3,4-difluoro-5-methylcycloheptyl, chloromethyl, 2-dichlorocyclopropyl, and 2,3-dichlorocyclopentyl. 5 Halogenated aryl groups for are exemplified by, but not limited to, chlorobenzyl and fluorobenzyl. 5 can be an independently selected monovalent hydrocarbon group.

[0022] Alternatively, the polyorganohydrogensiloxane may have the average formula: (R 6 3SiO 1 / 2 ) hh (R 5 2SiO 2 / 2 ) ii (R5HSiO 2 / 2 ) jj [In the formula, each R 6 are independently hydrogen or R 5 And each R 5are as above, with subscript hh≧2, subscript ii≧0, and subscript jj≧2. Alternatively, subscript hh is 2 to 10, alternatively 2 to 8, alternatively 2 to 6. Alternatively, subscript ii is 0 to 1,000, alternatively 1 to 500, alternatively 1 to 200. Alternatively, subscript jj is 2 to 500, alternatively 2 to 200, alternatively 2 to 100. Alternatively, each R 6 is R 5 It is.

[0023] Alternatively, the polyorganohydrogensiloxane is (R 6 3SiO 1 / 2 ) hh (R 5 2SiO 2 / 2 ) ii (R 5 HSiO 2 / 2 ) jj (R 5 SiO 3 / 2 ) kk , (R 6 3SiO 1 / 2 ) hh (R 5 2SiO 2 / 2 ) ii (R 5 HSiO 2 / 2 ) jj (SiO 4 / 2 ) mm , (R 6 3SiO 1 / 2 ) hh (R 5 2SiO 2 / 2 ) ii (R 5 HSiO 2 / 2 ) jj (SiO 4 / 2 ) mm (R 5 SiO 3 / 2 ) kk and combinations of two or more thereof, wherein each R 6 , R 5and subscripts hh, ii, and jj are as defined above, and subscript kk is ≧0 and subscript mm is ≧0. Alternatively, 1≧kk≧0, and 1≧mm≧0.

[0024] Alternatively, the polyorganohydrogensiloxane can be linear and contain pendant silicon-bonded hydrogen atoms. The polyorganohydrogensiloxane has the average formula: (CH3)3SiO[(CH3)2SiO] ii [(CH3)HSiO] jj Si(CH3)3 wherein the subscripts ii and jj are defined above.

[0025] Alternatively, the polyorganohydrogensiloxane can be linear and contain terminal silicon-bonded hydrogen atoms. The polyorganohydrogensiloxane has the average formula: H(CH3)2SiO[(CH3)2SiO] ii Si(CH3)2H The organohydrogensiloxane may be a SiH-terminated dimethylpolysiloxane having the formula: where subscript ii is as defined above. The SiH-terminated dimethylpolysiloxane may be used alone or in combination with the dimethyl, methyl-hydrogenpolysiloxanes disclosed above. When mixtures are used, the relative amounts of each organohydrogensiloxane in the mixture may vary.

[0026] Alternatively, the polyorganohydrogensiloxane may contain both pendant and terminal silicon-bonded hydrogen atoms. Alternatively, the polyorganohydrogensiloxane may generally be represented by the formula (R 6 2SiO) nn (R 5 HSiO) oo [In the formula, R 6 and R 5where n is as defined above, the subscript nn is an integer from 0 to 7, and the subscript oo is an integer from 3 to 10. Specific examples of suitable organohydrogensiloxanes of this type include (OSiMeH)4, (OSiMeH)3(OSiMeCH 13 ), (OSiMeH)2(OSiMeC6H 13 )2, and (OSiMeH)(OSiMeC6H 13 )3 [wherein Me represents methyl (-CH3)].

[0027] Other examples of suitable polyorganohydrogensiloxanes are those having at least two SiH containing cyclosiloxane rings in one molecule. Such organohydrogensiloxanes may be any organopolysiloxane having at least two cyclosiloxane rings with at least one silicon-bonded hydrogen (SiH) atom on each siloxane ring. The cyclosiloxane rings contain at least three siloxy units (which are the minimum units required to form a siloxane ring) and can be any combination of mono-, di-, tri-, and tetra-functional siloxy units forming a cyclic structure, provided that at least one of the cyclic siloxy units of each siloxane ring contains one SiH unit and can be a mono-, di-, and / or trifunctional siloxy unit. These siloxy units can be, for example, (MeHSiO 2 ) or (MeHSiO 3 ) when the non-hydrogen substituent is methyl, respectively. 1 / 2 ), (MeHSiO 2 / 2 ), and (HSiO 3 / 2 ) siloxy units.

[0028] Alternatively, starting material (B) may be a crosslinker having an average of at least three silicon-bonded hydrogen atoms per molecule, and the curable composition may be a release coating composition. The crosslinker may be present in an amount sufficient to provide a molar ratio of silicon-bonded hydrogen atoms to aliphatically unsaturated groups (SiH:Vi ratio) of >1:1 to 5:1, alternatively 1.2:1 to 2:1, in the release coating composition. The crosslinker may be represented by the unit formula (BI):(R 5 3SiO 1 / 2 )2(R 5 2SiO 2 / 2 ) pp (R5HSiO 2 / 2 ) qq [In the formula, R 5 where the subscript pp is ≧0, the subscript qq is >0, and the number (pp+qq) is 8 to 400. The subscripts pp and qq can have values ​​selected such that the polyorganohydrogensiloxane crosslinker has a viscosity at 25° C. of 5 to 1000 mPa s, alternatively 10 to 350 mPa s.

[0029] Polyorganohydrogensiloxanes having an average of at least 3 silicon-bonded hydrogen atoms per molecule for starting material (B) are exemplified by the following: B-1) Trimethylsiloxy-terminated poly(dimethyl / methylhydrogen)siloxane, B-2) Trimethylsiloxy-terminated polymethylhydrogensiloxane, B-3) Dimethylhydrogensiloxy-terminated poly(dimethyl / methylhydrogen)siloxane, B-4) Dimethylhydrogensiloxy-terminated polymethylhydrogensiloxane, and B-5) A combination of two or more of B-1) to B-4). The crosslinker may be one polyorganohydrogensiloxane crosslinker or a combination of two or more crosslinkers that differ in one or more properties selected from molecular weight, structure, siloxane unit, and sequence.

[0030] Alternatively, the starting material (B) in the release coating composition may comprise a clustered functional polyorganohydrogensiloxane. The clustered functional polyorganohydrogensiloxane has the unit formula: (R 5 2HSiO 1 / 2 ) aa (R 5 HSiO 2 / 2 ) bb (R 5 2SiO 2 / 2 ) cc (R 5 SiO 3 / 2 ) dd (SiO 4 / 2 ) ee ((R 5 ff )O (3-ff) / 2 SiD 1 SiR 5 ff O (3-ff) / 2 ) gg has.

[0031] In this formula, R 5 is as above, and each D 1 D independently represents a divalent hydrocarbon group of 2 to 18 carbon atoms. 1 Suitable divalent hydrocarbon groups for R D are exemplified by the groups described above for.

[0032] In the above formula, the subscript aa is ≧0, the subscript bb is ≧0, the number (aa+bb) is ≧4, the subscript cc is >0, the subscript dd is ≧0, the subscript ee is ≧0, the subscript ff is 0, 1, or 2, and the subscript gg is ≧2. Alternatively, the number (aa+bb) can be ≧6. Alternatively, the number (aa+bb) can be ≧8. The term "clustered functional polyorganohydrogensiloxane" means that the compound has a linear or branched siloxane backbone structure and that there are silicon-bonded hydrogen atoms in spatial proximity to each other at the terminal and / or pendant positions of the clustered functional polyorganohydrogensiloxane. Clustered functional polyorganohydrogensiloxanes can have a total of at least four silicon-bonded hydrogen atoms per molecule, with at least two of them in close proximity to each other, i.e., they are "clustered."

[0033] Alternatively, the clustered functional polyorganohydrogensiloxane has the following formula: [ka] , [In the formula, R 5 and D. 1 is as defined above. The subscript j is 0 to 2,000,000 and each subscript k is independently 1 to 12 (i.e., whereby each ring has 4 to 15 silicon atoms). Alternatively, the subscript j is 5 to 500,000, alternatively 5 to 100,000, alternatively 5 to 50,000, alternatively 10 to 50,000, alternatively 10 to 10,000, alternatively 10 to 5,000, alternatively 20 to 2,000. Alternatively, the subscript k is 1 to 8, alternatively 1 to 6, alternatively 1 to 4, alternatively 1 to 2, and alternatively k=1. Alternatively, B) the clustered functional polyorganohydrogensiloxane has the formula: [ka] [In the formula, R 5 , D 1 , and subscripts j and k are as above.

[0034] As used herein, the clustered functional polyorganohydrogensiloxane comprises: a) a polyorganosiloxane having an average of at least two silicon-bonded aliphatically unsaturated groups per molecule; b) an organohydrogensiloxane having an average of 4 to 15 silicon atoms per molecule and having silicon-bonded hydrogen atoms; and wherein the molar ratio of aliphatically unsaturated groups in starting material a) to silicon-bonded hydrogen atoms in starting material b) is from 1 to 3 to 1 to 20. Clustered functional polyorganohydrogensiloxanes and methods for preparing them are disclosed in U.S. Patent Application Publication No. 2016 / 0009865, U.S. Patent No. 7,378,482, U.S. Patent No. 7,429,636, U.S. Patent No. 7,432,338, U.S. Patent No. 7,449,536, and U.S. Patent No. 7,906,605.

[0035] The starting material (B) can include a combination or two or more different polyorganohydrogensiloxanes that differ in at least one property, such as structure, molecular weight, monovalent groups bonded to silicon atoms, and SiH content. Consider this broad description of crosslinkers for release coating compositions.

[0036] Starting material (C) The starting material (C) in the release coating composition is a hydrosilylation reaction catalyst. Suitable hydrosilylation reaction catalysts for starting material (C) are as described above for starting material iii). The hydrosilylation reaction catalyst for the release coating composition can be the same as that used as starting material iii). Alternatively, a different hydrosilylation reaction catalyst may be used in the release coating composition.

[0037] Starting material (D) The starting material (D) in the release coating composition is a polyorganosiloxane containing at least two silicon-bonded aliphatic unsaturated groups per molecule, or a polyorganosiloxane having an average of at least two silicon-bonded groups per molecule with terminal aliphatic unsaturation. This polyorganosiloxane may be linear, branched, partially branched, cyclic, resinous (i.e., having a three-dimensional network), or may include a combination of different structures. The polyorganosiloxane has an average formula R 4 s SiO (4-s) / 2 [wherein each R 4 is independently selected from a monovalent hydrocarbon group or a monovalent halogenated hydrocarbon group, provided that in each molecule, at least two of the R 4 contain terminal aliphatic unsaturation, and the subscript s is selected such that 0 < s ≦ 3.2]. Alternatively, the above average formula for the polyorganosiloxane is (R 4 3SiO 1 / 2 ) t (R 4 2SiO 2 / 2 ) u (R 4 SiO 3 / 2 ) v (SiO 4 / 2 ) w [wherein the subscripts t, u, v, and w are mole fractions and are each independently values of ≧ 0 to ≦ 1, provided that the numerical value (t + u + v + w) = 1]. Those skilled in the art will understand such units and how their mole fractions affect the subscript s in the above average formula. The trifunctional units (represented by the subscript v), the tetrafunctional units (represented by the subscript w), or both are typically present in the polyorganosiloxane resin, while the bifunctional units represented by the subscript u are typically present in the polydiorganosiloxane polymer (and may also be present in the polyorganosiloxane resin).

[0038] Each R 4are independently selected and may be linear, branched, cyclic, or combinations thereof, as described above. Cyclic hydrocarbon groups include aryl groups, and saturated or non-conjugated cyclic groups. Aryl groups may be monocyclic or polycyclic. Linear and branched hydrocarbon groups may be independently saturated or unsaturated.

[0039] A halogenated hydrocarbon group is a hydrocarbon group in which one or more hydrogen atoms have been replaced (i.e., substituted) with a halogen atom, such as chlorine, fluorine, bromine, or iodine. R 4 Suitable monovalent hydrocarbon groups and monovalent halogenated hydrocarbon groups for R 5 As described above.

[0040] (D) In ​​each molecule of polyorganosiloxane, R 4 At least two of R contain aliphatic unsaturation. 4 R may be independently selected from alkenyl and alkynyl groups. 4 Alkenyl groups for are exemplified by, but are not limited to, vinyl, allyl, and hexenyl. The alkenyl groups may have 2 to 30 carbon atoms, alternatively 2 to 24 carbon atoms, alternatively 2 to 20 carbon atoms, alternatively 2 to 12 carbon atoms, alternatively 2 to 10 carbon atoms, alternatively 2 to 6 carbon atoms. Alkynyl is exemplified by, but is not limited to, ethynyl, propynyl, and butynyl. The alkynyl groups may have 2 to 30 carbon atoms, alternatively 2 to 24 carbon atoms, alternatively 2 to 20 carbon atoms, alternatively 2 to 12 carbon atoms, alternatively 2 to 10 carbon atoms, alternatively 2 to 6 carbon atoms. Alternatively, (D) polyorganosiloxane may contain at least two silicon-bonded alkenyl groups per molecule and may contain zero silicon-bonded alkynyl groups.

[0041] Alternatively, the (D) polyorganosiloxane may be substantially linear or may be linear. The substantially linear polyorganosiloxane has the average formula R 4 s’ SiO(4-s’) / 2 [In the formula, each R 4 is as defined above, and the subscript s' is selected such that 1.9≦s'≦2.2.

[0042] At RT, the substantially linear polyorganosiloxane may be a flowable liquid or may have the form of an uncured rubber. The substantially linear polyorganosiloxane may have a viscosity at 25° C. of from 10 mPa·s to 30,000,000 mPa·s, alternatively from 10 mPa·s to 10,000 mPa·s, alternatively from 100 mPa·s to 1,000,000 mPa·s, alternatively from 100 mPa·s to 100,000 mPa·s. Viscosity may be measured according to ASTM standard D4287 using a Brookfield LV DV-E viscometer.

[0043] Alternatively, when the (D) polyorganosiloxane is substantially linear or linear, the polyorganosiloxane has the average formula: (R 4” 3SiO 1 / 2 ) m (R 4” 2SiO 2 / 2 ) n (R 4’ R 4” SiO 2 / 2 ) o (R 4” 2R 4’ SiO 1 / 2 ) p [In the formula, R 4 As defined above, each R 4” is independently selected from a monovalent hydrocarbon group free of aliphatic unsaturation or a monovalent halogenated hydrocarbon group free of aliphatic unsaturation; each R 4’are independently selected from a monovalent aliphatic unsaturated hydrocarbon group or a monovalent halogenated aliphatic unsaturated hydrocarbon group, subscript m is ≧0, subscript n is ≧0, subscript o is ≧2, and subscript p is ≧0, with the proviso that the number (m+p) is ≧2. Alternatively, m is 0-10, alternatively 2-10, alternatively 2-8, alternatively 2-6. Alternatively, subscript n is 0-1,000, alternatively 1-500, alternatively 1-200. Alternatively, subscript o is 2-500, alternatively 2-200, alternatively 2-100. Alternatively, p is 0-10, alternatively 2-10, alternatively 2-8, alternatively 2-6.

[0044] (D) The polyorganosiloxane is substantially linear, or if linear, the at least two aliphatically unsaturated groups may be bonded to silicon atoms at pendant positions, terminal positions, or both pendant and terminal positions. As specific examples of polyorganosiloxanes having pendant silicon-bonded aliphatically unsaturated groups, the starting material D) may have the average unit formula: [(CH3)3SiO]2[(CH3)2SiO] n [(CH3)ViSiO] o where the subscripts n and o are defined above. With respect to this average formula, any of the methyl groups may be replaced with a different monovalent hydrocarbon group, such as an alkyl or aryl, and any of the vinyl groups may be replaced with a different aliphatically unsaturated monovalent hydrocarbon group, such as an allyl or hexenyl. Alternatively, as a specific example of (D), the polyorganosiloxane having terminal silicon-bonded aliphatic unsaturated groups, starting material (D) may have the average formula: Vi(CH3)2SiO[(CH3)2SiO] nSi(CH3)2Vi, where the subscript n is defined above. The silicon-bonded vinyl terminated dimethylpolysiloxanes can be used alone or in combination with the dimethyl,methyl-vinylpolysiloxanes disclosed above. With respect to this average formula, any of the methyl groups can be replaced with a different monovalent hydrocarbon group, and any of the vinyl groups can be replaced with any aliphatically unsaturated monovalent hydrocarbon group. Since at least two of the silicon-bonded aliphatically unsaturated groups can be both pendant and terminal, the (D) polyorganosiloxane can alternatively have the average unit formula: [Vi(CH3)2SiO]2[(CH3)2SiO] n [(CH3)ViSiO] o SiVi, where the subscripts n and o are defined above.

[0045] The substantially linear polyorganosiloxane is, for example, a dimethylpolysiloxane having both molecular chain terminals blocked by dimethylvinylsiloxy groups, a methylphenylpolysiloxane having both molecular chain terminals blocked by dimethylvinylsiloxy groups, a methylphenylsiloxane-dimethylsiloxane copolymer having both molecular chain terminals blocked by dimethylvinylsiloxy groups, a methylvinylsiloxane-methylphenylsiloxane copolymer having both molecular chain terminals blocked by dimethylvinylsiloxy groups, or a methylvinylsiloxane-diphenylsiloxane copolymer having both molecular chain terminals blocked by dimethylvinylsiloxy groups. mer, methylvinylsiloxane-methylphenylsiloxane-dimethylsiloxane copolymers capped at both molecular chain terminals with dimethylvinylsiloxy groups, methylvinylsiloxane-methylphenylsiloxane copolymers capped at both molecular chain terminals with trimethylsiloxy groups, methylvinylsiloxane-diphenylsiloxane copolymers capped at both molecular chain terminals with trimethylsiloxy groups, and methylvinylsiloxane-methylphenylsiloxane-dimethylsiloxane copolymers capped at both molecular chain terminals with trimethylsiloxy groups.

[0046] The starting materials (A), (B), (C), and (D) may be added in an amount sufficient to render the release coating composition curable to form a release coating. The release coating composition may include the (A) controlled release additive in an amount of 1% to 75%, alternatively 5% to 25%, by weight, based on the combined weight of the starting materials (A), (B), (C), and (D). The starting material (B) polyorganohydrogensiloxane may be present in an amount of 0.1% to 5%, alternatively 0.2% to 5%, by weight, based on the combined weight of the starting materials (A), (B), (C), and (D). The starting material (C) hydrosilylation reaction catalyst is present in a catalytically effective amount. A catalytically effective amount is sufficient to catalyze the hydrosilylation reaction and may be an amount sufficient to provide from 5 ppm to 300 ppm, alternatively from 5 ppm to 100 ppm of platinum group metal, based on the combined weight of starting materials (A), (B), (C), and (D). The organopolysiloxane having at least two silicon-bonded aliphatically unsaturated groups per molecule of starting material (D) may be present in an amount of from 20% to 98%, alternatively from 75% to 90%, by weight, based on the combined weight of starting materials (A), (B), (C), and (D). The starting materials may be added in an amount sufficient to provide a molar ratio of silicon-bonded hydrogen atoms to silicon-bonded aliphatically unsaturated groups of from 1:1 to 2.5:1, alternatively from 1.3:1 to 1.5:1 (overall SiH:Vi ratio) in the combined starting materials (A), (B), (C), and (D).

[0047] Starting material (E) Solvent Starting material (E) is a solvent as described above for starting material v). The polysiloxane may be prepared in a solvent for starting material v) and delivered to the release coating composition in solution using that solvent. The solvent used in the release coating composition starting material (E) may be the same as the solvent selected for starting material v). Alternatively, the solvent may be a different solvent than that described above in the preparation of the polysiloxane and may be in addition to the solvent for starting material v). The amount of solvent in the release coating composition will vary depending on a variety of factors, including the type and amount of starting materials (A)-(D) selected, whether any additional starting materials are added to the composition, and the amount of starting material v) used to deliver starting material (A), but the amount of solvent may be up to 99% by weight, alternatively 20% to 99% by weight, alternatively 50% to 95% by weight, alternatively 70% to 90% by weight, alternatively 80% to 90% by weight, based on the total weight of starting materials (A)-(E) in the release coating composition.

[0048] Starting Material F) Hydrosilylation Reaction Inhibitors Starting material (F) is a hydrosilylation reaction inhibitor (inhibitor) that may optionally be used to modify the rate of reaction of silicon-bonded hydrogen atoms of starting material (B) with aliphatically unsaturated hydrocarbon groups of starting material (A) compared to the reaction rate with the same starting materials but omitting the inhibitor. Inhibitors include acetylenic alcohols such as methylbutynol, ethynylcyclohexanol, dimethylhexynol, and 3,5-dimethyl-1-hexyn-3-ol, 1-butyn-3-ol, 1-propyn-3-ol, 2-methyl-3-butyn-2-ol, 3-methyl-1-butyn-3-ol, 3-methyl-1-pentyn-3-ol, 3-phenyl-1-butyn-3-ol, 4-ethyl-1-octyn-3-ol, 3,5-dimethyl-1-hexyn-3-ol, and 1-ethynyl-1-cyclohexanol, and combinations thereof; cycloalkenyl siloxanes such as methylvinylcyclosiloxanes exemplified by 1,3,5,7-tetramethyl-1,3,5,7-tetravinylcyclotetrasiloxane, 1,3,5,7-tetramethyl-1,3,5,7-tetrahexenylcyclotetrasiloxane, and combinations thereof. amines such as tetramethylethylenediamine, 3-dimethylamino-1-propyne, n-methylpropargylamine, propargylamine, and 1-ethynylcyclohexylamine; dialkyl fumarates such as diethyl fumarate, dialkenyl fumarates such as diallyl fumarate, dialkoxyalkyl fumarates, maleic esters such as diallyl maleate and diethyl maleate; nitriles; ethers; carbon monoxide; alkenes such as cyclooctadiene, divinyltetramethyldisiloxane; alcohols such as benzyl alcohol; and combinations thereof.

[0049] Alternatively, starting material (iv) can be a silylated acetylenic compound. Without wishing to be bound by theory, it is believed that the addition of the silylated acetylenic compound reduces the yellowing of the reaction product prepared from the hydrosilylation reaction as compared to reaction products from the hydrosilylation of starting materials that do not contain a silylated acetylenic compound or that contain an organic acetylenic alcohol inhibitor such as those described above.

[0050] The silylated acetylene compounds are (3-methyl-1-butyne-3-oxy)trimethylsilane, ((1,1-dimethyl-2-propynyl)oxy)trimethylsilane, bis(3-methyl-1-butyne-3-oxy)dimethylsilane, bis(3-methyl-1-butyne-3-oxy)silanemethylvinylsilane, bis((1,1-dimethyl-2-propynyl)oxy)dimethylsilane, methyl(tris(1,1-dimethyl-2-propynyloxy))silane, methyl(tris(3-methyl-1-butyne-3-oxy))silane, (3-methyl-1-butyne-3-oxy)dimethylphenylsilane, (3-methyl-1-butyne-3-oxy)dimethylhexenylsilane, (3-methyl-1-butyne-3-oxy)triethylsilane, bis(3-methyl-1- silane, (3,5-dimethyl-1-hexyne-3-oxy)trimethylsilane, (3-phenyl-1-butyne-3-oxy)diphenylmethylsilane, (3-phenyl-1-butyne-3-oxy)dimethylphenylsilane, (3-phenyl-1-butyne-3-oxy)dimethylvinylsilane, (3-phenyl-1-butyne-3-oxy)dimethylhexenylsilane, (cyclohexyl-1-ethyne-1-oxy)dimethylhexenylsilane, (cyclohexyl-1-ethyne-1-oxy)dimethylvinylsilane, (cyclohexyl-1-ethyne-1-oxy)diphenylmethylsilane, (cyclohexyl-1-ethyne-1-oxy)trimethylsilane, and combinations thereof. Alternatively, the silylated acetylenic compound is exemplified by methyl(tris(1,1-dimethyl-2-propynyloxy))silane, ((1,1-dimethyl-2-propynyl)oxy)trimethylsilane, or combinations thereof. The silylated acetylenic compounds useful as inhibitors herein may be prepared by methods known in the art. For example, U.S. Pat. No. 6,677,740 discloses the silylation of the above acetylenic alcohols by reaction with chlorosilanes in the presence of an acid acceptor.

[0051] The amount of inhibitor added herein will vary depending on a variety of factors, including the desired reaction rate, the particular inhibitor used, and the selection and amount of starting materials (A) and (B). However, if present, the amount of inhibitor may range from >0% to 1%, alternatively >0% to 5%, alternatively 0.001% to 1%, alternatively 0.01% to 0.5%, alternatively 0.002% to 0.15%, alternatively 0.0025% to 0.025% by weight, based on the combined weight of all starting materials used to prepare the polysiloxane.

[0052] Starting material (G) Anchor additive Starting material (G) is an anchor additive that can be added to the release coating composition optionally.Suitable anchor additives are exemplified by the reaction product of vinylalkoxysilane and epoxy-functional alkoxysilane; the reaction product of vinylalkoxysilane and epoxy-functional alkoxysilane; and the combination (e.g., physical blend and / or reaction product) of polyorganosiloxane having at least one aliphatically unsaturated hydrocarbon group and at least one hydrolyzable group per molecule with epoxy-functional alkoxysilane (e.g., the combination of hydroxy-terminated vinyl-functional polydimethylsiloxane and glycidoxypropyltrimethoxysilane).Suitable anchor additives and their preparation methods are disclosed, for example, in U.S. Pat. No. 9,562,149, U.S. Patent Application Publication Nos. 2003 / 0088042, 2004 / 0254274, and 2005 / 0038188, and European Patent No. 0556023. Although the exact amount of anchor additive will vary depending on a variety of factors, such as the type of substrate and whether a primer is used, the amount of anchor additive in the release coating composition may be from 0 to 2 parts by weight per 100 parts by weight of starting material (D). Alternatively, the amount of anchor additive may be from 0.01 to 2 parts by weight per 100 parts by weight of starting material (D).

[0053] Starting material (H) Mist prevention additive The starting material (H) is an anti-mist additive that can be added to the release coating composition to reduce or inhibit silicone mist formation during the coating process, especially in high speed coating equipment. The anti-mist additive can be a reaction product of an organohydrogensilicon compound, an oxyalkylene compound, or an organoalkenylsiloxane having at least three silicon-bonded alkenyl groups in one molecule, and a suitable catalyst. Suitable anti-mist additives are disclosed, for example, in U.S. Patent Application Publication No. 2011 / 0287267, U.S. Patent No. 8,722,153, U.S. Patent No. 6,586,535, and U.S. Patent No. 5,625,023. The amount of the anti-mist additive will vary depending on a variety of factors, including the amount and type of other starting materials selected for the release coating composition. However, the amount of the anti-mist additive can be 0% to 10% by weight, alternatively 0.1% to 3% by weight, based on the weight of all starting materials in the release coating composition.

[0054] The release coating composition may further include one or more optional additives such as colorants, dyes, pigments, fillers, e.g., silica, quartz or chalk, reactive diluents, preservatives, and / or fragrances. Alternatively, the release coating may be free of particulates (e.g., fillers) or contain only limited amounts of particulates, e.g., 0-30% by weight of the release coating composition. Without wishing to be bound by theory, it is believed that fillers may agglomerate or otherwise stick to the coater equipment used to apply the release coating. These may interfere with the optical properties, e.g., transparency, of the release coating and release liner formed therewith, when optical clarity is desired. Particulates may be detrimental to the adhesion of the adherend (e.g., adhesive tape or label).

[0055] In selecting starting materials for the release coating composition, certain starting materials described herein may have more than one function, so there may be overlap in the types of starting materials. Certain particulates, such as carbon black, may be useful as fillers, pigments, and even flame retardants. If additional starting materials are added to the composition, the additional starting materials are different from starting materials (A)-(D) and different from each other. Alternatively, the release coating composition may consist only of starting materials (A)-(D), or only of starting materials (A)-(E), or only of starting materials (A)-(F). Alternatively, the release coating composition may consist only of starting materials (A)-(D) and one or both of (G) and / or (H). Alternatively, the release coating composition may consist only of starting materials (A)-(E) and one or both of (G) and / or (H). Alternatively, the release coating composition may consist only of starting materials (A)-(F) and one or both of (G) and / or (H).

[0056] The release coating composition may be free of fluoroorganosilicone compounds. It is believed that during curing, due to its low surface tension, the fluoro compound quickly migrates to the interface between the coating composition and the substrate, e.g., the polyorganosiloxane release coating composition / PET film interface, forming a fluorine-containing barrier, thereby preventing adhesion of the release coating (prepared by curing the release coating composition) to the substrate. By forming a barrier, the fluoro compound prevents any of the components from reacting at the interface. Furthermore, fluorosilicone compounds are usually expensive.

[0057] Preparation of the Release Coating Composition The release coating composition can be prepared by combining the starting materials including (A), (B), (C) and (D) with any optional additional starting materials, such as (E), (F), (G) and / or (H), in any order of addition, optionally via master batches, and optionally under shear. The release coating composition can be prepared by mixing the starting materials together to prepare, for example, a single-part composition. However, it may be desirable to prepare the release coating composition as a multi-part composition in which the starting materials (e.g., starting materials (B) and (C)) are stored in separate parts until the parts are combined at the time of use (e.g., immediately prior to application to a substrate).

[0058] For example, a multi-part composition may include: Part (A), i.e., a base part comprising: (D) at least a portion of a polyorganosiloxane having an average of at least two silicon-bonded hydrocarbon groups per molecule having aliphatic unsaturation; (C) a hydrosilylation reaction catalyst; and, if present, one or more of (E) a solvent, (F) an inhibitor, (G) an anchor additive, and (H) an anti-mist additive; Part (B), i.e., (D) at least a portion of a polyorganosiloxane having an average of at least two silicon-bonded hydrocarbon groups per molecule having aliphatic unsaturation, (B) a polyorganohydrogensiloxane, and, if present, (F) an inhibitor, (G) an anchor additive, (E) a solvent, or two or more of (E), (F), and (G).

[0059] The starting material (A), the controlled release additive, can be added to either part (A), part (B), or both. Part (A) and part (B) can be combined in a weight ratio of 1:1 to 10:1, alternatively 1:1 to 5:1, alternatively 1:1 to 2:1. Part (A) and part (B) can be provided in a kit, along with instructions, for example, on how to combine the parts to prepare the release coating composition, how to apply the release coating composition to a substrate, and how to cure the release coating composition.

[0060] Alternatively, if an anchor additive is present, it can be incorporated in either part (A) or part (B), or it can be added to a separate (third) part.

[0061] The present invention also provides a process for preparing a release liner using the release coating composition. The method of the present invention includes applying the release coating composition onto a surface of a substrate. The method of the present invention further includes curing the release coating composition to form a release coating on the surface of the substrate.

[0062] The method of the present invention for preparing a release liner may further comprise treating the surface of the substrate before providing the release coating composition on the surface of the substrate. The treatment of the substrate may be carried out by any convenient means, such as plasma treatment or corona discharge treatment. Alternatively, the substrate may be treated by applying a primer. In certain cases, the anchorage of the release coating may be improved if the substrate is treated before coating.

[0063] The method for forming the release liner can further include removing the solvent, which can be carried out by any conventional means, such as heating at 50°C to 100°C after applying the release coating composition to the surface of the substrate, and before and / or during curing the release coating composition, for a time sufficient to remove all or a portion of the solvent. The method of the present invention further includes curing the release coating composition to form a release coating on the surface of the substrate. Curing can be carried out by heating at an elevated temperature, for example, 50°C to 200°C, alternatively 50°C to 180°C, alternatively 50°C to 120°C, alternatively 50°C to 90°C, to obtain the release liner. Those skilled in the art can select the appropriate temperature depending on various factors, such as the selection of the optional starting materials in the release coating composition and the substrate material of the structure. Alternatively, curing can be carried out by heating at 100°C to 200°C.

[0064] Under production coater conditions, curing can be accomplished with air temperatures of 120° C. to 150° C. and residence times of 1 to 6 seconds, alternatively 1.5 to 3 seconds. Heating for the solvent removal and curing steps can be carried out in an oven, such as an air circulating oven or tunnel furnace, or by passing the coated substrate around a heated cylinder.

[0065] The release coating composition can be applied (placed or distributed) on the surface of the substrate in any suitable manner. Typically, the release coating composition is applied in wet form by a wet coating technique. Alternatively, the release coating composition can be applied by i) spin coating; ii) brush coating; iii) drop coating; iv) spray coating; v) dip coating; vi) roll coating; vii) flow coating; viii) slot coating; ix) gravure coating; x) Mayer bar coating; or xi) any combination of i)-x). Alternatively, the release coating composition can be applied to the surface of the substrate by a means selected from the group consisting of spraying, doctor blade, dipping, screen printing, or by a roll coater, such as an offset web coater, kiss coater, or etched cylinder coater.

[0066] The substrate is not limited and can be any substrate suitable for forming a release liner. The release coating (formed by curing the release coating composition) can be physically and / or chemically bonded to the substrate, depending on the selection. The substrate can be subjected to an integrated hot plate or an integrated or stand-alone oven for curing the deposit. The substrate can optionally have a continuous or non-continuous shape, size, dimension, surface roughness, and other characteristics. Alternatively, the substrate can have an elevated softening point temperature. However, the release coating composition and method are not so limited.

[0067] The substrate may comprise a plastic, which may be thermoset and / or thermoplastic, but may alternatively be glass, metal, paper, cardboard, paperboard, silicone, or a polymeric material, or a combination thereof.

[0068] Specific examples of suitable substrates include paper substrates such as kraft paper and polyethylene-coated kraft paper (PEK-coated paper); polymer substrates such as polyamide (PA); polyesters such as polyethylene terephthalate (PET), polybutylene terephthalate (PET), polytrimethylene terephthalate (PTT), polyethylene naphthalate (PEN), and liquid crystal polyester; polyolefins such as polyethylene (PE), polypropylene (PP), and polybutylene; styrene resins; polyoxymethylene (POM); polycarbonate (PC); polymethylene methacrylate (PMMA); polyvinyl chloride (PVC); polyphenylene sulfide (PPS); polyphenylene ether (PPE); polyimide (PI); and polyamide imide. Examples of the release coating composition include polyetherimide (PAI); polyetherimide (PEI); polysulfone (PSU); polyethersulfone; polyketone (PK); polyetherketone; polyvinyl alcohol (PVA); polyetheretherketone (PEEK); polyetherketoneketone (PEKK); polyarylate (PAR); polyethernitrile; phenolic resin; phenoxy resin; cellulose such as triacetyl cellulose, diacetyl cellulose, cellophane; fluorinated resin such as polytetrafluoroethylene; thermoplastic elastomers such as polystyrene type, polyolefin type, polyurethane type, polyester type, polyamide type, polybutadiene type, polyisoprene type, fluoro type; and copolymers, modifications, and combinations thereof. Alternatively, the substrate may comprise a polymer film substrate selected from the group consisting of polyester, particularly polyethylene terephthalate (PET), polyethylene, polypropylene, or polystyrene films, or the substrate may comprise a paper substrate, including plastic-coated paper, such as polyethylene-coated paper, glassine, supercalendered paper, or clay-coated kraft. The release coating composition may alternatively be applied to a metal foil substrate, such as aluminum foil. Alternatively, the substrate may be PET.

[0069] The release coating composition, or wet deposit on the substrate, can be cured at elevated temperature for a period of time. The period is typically sufficient to effect cure of the release coating composition. Alternatively, the period is from greater than 0 to 8 hours, alternatively from greater than 0 to 2 hours, alternatively from greater than 0 to 1 hour, alternatively from greater than 0 to 30 minutes, alternatively from greater than 0 to 15 minutes, alternatively from greater than 0 to 10 minutes, alternatively from greater than 0 to 5 minutes, alternatively from greater than 0 to 2 minutes. The period of time will vary depending on a variety of factors, such as the presence of the elevated temperature used, the temperature selected, the desired film thickness, the absence of any water or carrier vehicle in the curable composition, etc.

[0070] The step of curing the release coating composition typically has a residence time of 0.1 seconds to 50 seconds, alternatively 1 second to 10 seconds, alternatively 0.5 seconds to 30 seconds. The residence time selected may vary depending on the choice of substrate, the temperature selected, and the line speed. As used herein, residence time refers to the time that the release coating composition or wet deposit is exposed to an elevated temperature. Residence time is distinct from cure time, since there may be ongoing curing even after the release coating composition, wet deposit, or partially cured reaction intermediate thereof is no longer exposed to the elevated temperatures that typically initiate curing. Alternatively, the coated substrate is prepared on a conveyor belt in an oven, and the residence time can be calculated (e.g., meters / second) by dividing the length of the oven (e.g., in meters) by the line speed of the conveyor belt.

[0071] The time can be subdivided into iterations of cure, e.g., a first cure and a post cure, e.g., 1 hour for the first cure and 3 hours for the post cure. The elevated temperature can be independently selected in such iterations from any temperature above room temperature and can be the same in each iteration.

[0072] Depending on the thickness and other dimensions of the film of release coating composition and the coated substrate, the coated substrate can be formed through an iterative process. For example, a first deposit can be formed and exposed to a first elevated temperature for a first time to obtain a partially cured deposit. A second deposit can then be placed on the partially cured deposit and exposed to a second elevated temperature for a second time to obtain a second partially cured deposit. This partially cured deposit also further cures while exposed to the second elevated temperature for a second time. A third deposit can be placed on the second partially cured deposit and exposed to a third elevated temperature for a third time to obtain a third partially cured deposit. The second partially cured deposit also further cures while exposed to the second elevated temperature for a second time. This process can be repeated, for example, 1 to 50 times, to build up the coated article as desired. The composite of partially cured layers is subjected to a final post-cure, for example, exposed to the elevated temperatures and times described above. Each elevated temperature and time may be independently selected and may be the same or different from one another. When the article is formed via an iterative process, each deposit may also be independently selected and may differ in the starting materials selected in the curable composition, their amounts, or both. Alternatively or further, each repeating layer may be fully cured, rather than only partially cured, in such an iterative process.

[0073] Alternatively, the deposit comprises a wet film. The iterative process may be wet-on-wet, depending on the curing state of the partially cured layer. Alternatively, the iterative process may be wet-on-dry.

[0074] The release liner, including the release coating formed from curing the release coating composition on the surface of the substrate, can have a variety of dimensions, including the relative thickness of the release coating and the substrate. The release coating has a thickness that can vary depending on its end use application. The release coating can have a thickness of from greater than 0 to 4,000 μm, alternatively from greater than 0 to 3,000 μm, alternatively from greater than 0 to 2,000 μm, alternatively from greater than 0 to 1,000 μm, alternatively from greater than 0 to 500 μm, alternatively from greater than 0 to 250 μm. However, other thicknesses are contemplated, for example, from 0.1 μm to 200 μm. For example, the thickness of the release coating may be any one of 0.2 μm to 175 μm; alternatively 0.5 μm to 150 μm; alternatively 0.75 to 100 μm; alternatively 1 to 75 μm; alternatively 2 to 60 μm; alternatively 3 to 50 μm; alternatively 4 μm to 40 μm; alternatively 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, 20, 25, 30, 35, 40, 45, 50, 60, 70, 75, 80, 90, 100, 150, 175, and 200 μm. When the substrate is plastic, the release coating may have a thickness of greater than 0 to 200 μm, alternatively greater than 0 to 150 μm, or alternatively greater than 0 to 100 μm.

[0075] The release liners prepared as described above are useful for tapes or adhesives, such as any pressure sensitive adhesive, such as acrylic, rubber, and silicone type pressure sensitive adhesives, as well as acrylic, synthetic rubber, silicone, epoxy, and polyurethane type adhesives. Each major surface of the substrate may have a release coating disposed thereon for a double-sided tape or adhesive. EXAMPLES

[0076] These examples are intended to illustrate the invention to one of ordinary skill in the art and should not be construed as limiting the scope of the invention as set forth in the claims. The materials in Table 1 were used in these examples. [Table 1]

[0077] DOWSIL™ and SYSYL OFF™ materials are available from Dow Silicones Corporation.

[0078] Reference Example 1 Preparation of polysiloxane The following starting materials were used to form the mixture: 100 parts MQM Vi The resin, 5 parts solvent 1, and sufficient catalyst 1 to provide 1-2 ppm platinum group metal in the mixture were combined. The resulting reaction mixture was heated to 80° C. A sufficient amount of SiH terminated oligomer or SiH terminated PDMS to provide a SiH / Vi ratio of >0.2-0.3 was metered into the mixture over a period of 1 hour. The samples prepared are summarized in Table 2 below. The amount of each starting material is in weight %. [Table 2]

[0079] The resulting sample was polysiloxane dissolved in the solvent.

[0080] Reference Example 2 Preparation of Release Coating Composition Release coating compositions were prepared. Comparative bath 1, as a control, had no controlled release additive. Comparative baths 2 and 3 contained a polyorganosilicate resin as a comparative controlled release additive. Baths 4-11 contained a polysiloxane from Table 2 used as a controlled release additive (CRA). Release coating compositions were prepared by mixing the controlled release additive (if present), 1 base polymer, 1 inhibitor, 1 crosslinker, and 1 catalyst in the amounts shown in Tables 3 (comparative) and 4 (working) below. The amount of each starting material was in parts by weight. Each bath had a SiH / Vi ratio of 1.5:1. [Table 3] [Table 4]

[0081] Reference Example 3 Preparation and testing of release liners The release coating compositions of Tables 3 and 4 were coated onto a PET substrate using a Mayer bar #5. The resulting coated substrate was heated at 130°C for 10 seconds to remove the solvent and cure the release coating composition, thereby forming a release liner with a release coating on the surface of the PET substrate. The sample was aged. Then, 1 inch TESA™ 7475 tape was applied to the release coating. The sample was aged and then the release force was measured using a 180 degree peel test by peeling at 0.3 m / min using an AR-1000 from Cheminstrument Company. In Table 5 below, 1R-1R indicates that the sample was aged at RT for 1 day after coating and then the peel force was measured after 1 day at RT using TESA 7475 tape, 1R-1H indicates that the sample was left at RT for 1 day after coating and then the peel force was measured after 1 day at elevated temperature (50°C) using TESA 7475 tape, 34R-1R indicates that the sample was aged at RT for 34 days after coating and then the peel force was measured after 1 day at room temperature using TESA 7475 tape, and 34R-1H indicates that the sample was left at RT for 34 days after coating and then the peel force was measured after 1 day at elevated temperature (50°C) using TESA 7475 tape. Each sample was tested 3 times and the results were averaged. The averages are shown in Table 5. [Table 5]

[0082] A comparison of the release force results for Bath #2 (which contained 2 parts of a vinyl-functional polyorganosilicate resin described as an example of starting material i) instead of a polysiloxane prepared as described herein) with Baths #4, 6, 8, and 10, which contained 2 parts of a polysiloxane prepared as described herein, showed that each release liner containing a release coating prepared from Baths #4, 6, 8, and 10 on PET had a higher release force when tested after the same aging conditions than the comparative release coating that did not contain a polysiloxane prepared as described herein. Furthermore, a comparison of the release force results for Bath #3 (which contained 4 parts of a vinyl-functional polyorganosilicate resin described as an example of starting material i) instead of a polysiloxane prepared as described herein) with Baths #5, 7, 8, and 11, which contained 4 parts of a polysiloxane prepared as described herein, showed that each release liner containing a release coating prepared from Baths #5, 7, 8, and 11 on PET had a higher release force when tested after the same aging conditions than the comparative release coating that did not contain a polysiloxane prepared as described herein.

[0083] Comparative Example 4 Polyorganosiloxane is MQM Vi The comparative polysiloxanes were prepared by the condensation reaction method of U.S. Patent No. 8,933,177 using as starting materials a resin and a hydroxyl-terminated polydimethylsiloxane having a DP > 100. The comparative polysiloxanes were formulated into release coating compositions summarized below in Table 5. Each bath had a SiH / Vi ratio of 1.5:1. [Table 6]

[0084] Release liners were prepared and tested according to the method of Reference Example 3, but using the comparative release coating compositions of Table 5. The results are shown in Table 6 below. [Table 7]

[0085] "NA" means that results from these studies were not available.

[0086] Reference Example 5 Migration and hardening The release coating prepared as above was evaluated for sustained adhesive strength (SAS). SAS was evaluated by rubbing a finger on the release coating and determining the amount of release coating that was smeared and rubbed off from the substrate. The results are shown in Table 7 below. [Table 8]

[0087] A comparison of the SAS values ​​of release coatings prepared from Comparative Bath 12 with release coatings prepared from Baths 4, 6, 8, and 10 showed that Baths 4, 6, 8, and 10 each produced release coatings with better (higher) SAS values ​​than Comparative Bath 12. A comparison of the SAS values ​​of release coatings prepared from Comparative Bath 13 with release coatings prepared from Baths 5, 7, 9, and 11 showed that Baths 5, 7, 9, and 11 each produced release coatings with better SAS values ​​than Comparative Bath 13.

[0088] Industrial Applicability The above examples and comparative examples have shown that release coating compositions containing the novel polysiloxanes described herein as controlled release additives produce release coatings on PET with higher release forces after aging at both room temperature and elevated temperatures under the conditions of Reference Example 3 than the control (Bath #1) that does not contain the controlled release additive and the comparisons (Baths #2 and 3) that contain different amounts of vinyl-functional MQ resins. Furthermore, after aging for 34 days, the release coatings prepared from the release coating compositions containing the novel controlled release additives also had higher release forces than the comparative examples. The release coatings prepared from the release coating compositions containing the novel controlled release additives described herein produced release coatings with better sustained adhesive strength than the comparative release coatings containing the comparative controlled release additives disclosed in U.S. Pat. No. 8,933,177. Without wishing to be bound by theory, it is believed that for certain applications, release coatings with higher sustained adhesive strength (SAS) values ​​are desired. The present invention provides the benefit of being able to achieve release coatings with SAS of ≧94%, alternatively ≧95%, or alternatively ≧96%, while maintaining a desirable release force, even after aging.

[0089] Definitions and usage of terms All amounts, ratios, and percentages are by weight unless otherwise indicated. The Summary and Abstract of the Invention are incorporated herein by reference. The terms "comprising" or "comprise" are used herein in their broadest sense to mean and encompass the terms "including," "include," "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. Abbreviations used herein have the definitions in Table 6. [Table 9]

[0090] The present invention has been described in an illustrative manner, and it is to be understood that the terminology used is intended to be in the nature of words of description rather than for purposes of limitation. With respect to any Markush group on which a description of a specific feature or aspect is relied upon herein, different, unusual and / or unexpected results may result from each element of the respective Markush group, independent of all other elements of the Markush group. Each element of the Markush group may be relied upon individually and / or in combination to provide appropriate support for a particular embodiment within the scope of the appended claims.

[0091] Moreover, any ranges and subranges relied upon in describing the present invention are understood to be independently and inclusively within the scope of the appended claims and to describe and contemplate the entire range encompassing all values ​​therein, even if all and / or any values ​​therein are not expressly set forth herein. Those skilled in the art will readily recognize that the recited ranges and subranges fully describe and enable various embodiments of the present invention, and that such ranges and subranges may be further delineated into relevant halves, thirds, fourths, fifths, etc. By way of example only, the range "2-20" may be further detailed as the lower two-thirds, i.e., 2-8, the middle third, i.e., 8-14, and the upper third, i.e., 14-20, which are individually and collectively within the scope of the appended claims, and which may be relied upon and provide appropriate justification for specific embodiments within the scope of the appended claims, individually and / or collectively. Furthermore, with respect to words defining or modifying a range, such as "at least," "greater than," "less than," "less than," etc., such words should be understood to include subranges and / or upper or lower limits.

[0092] EMBODIMENTS OF THE PRESENT DISCLOSURE In embodiment 1, the release coating composition comprises: (A) Unit: M a Q b M U c D L de M OH q T OH r wherein subscript a is ≧30, subscript b is ≧40, subscript c is ≧1, subscript d is ≧1, the number (c+d) is ≧1, subscript e is 0 to 20, subscript q is ≧0, and subscript r is ≧0, with the proviso that the number (q+r) is sufficient to provide a polysiloxane having a silanol content of from 0 to 1.7%, M is the formula [ka] represents the unit of Q is the formula [ka] represents the unit of M U is the formula [ka] represents the unit of D L is the formula [ka] represents the unit of D is the formula [ka] represents the unit of M OH is the formula [ka] represents the unit of T OH is the formula [ka] represents the unit of Each R M is an independently selected monovalent hydrocarbon radical of 1 to 30 carbon atoms free of aliphatic unsaturation, and each R U is an independently selected monovalent aliphatic unsaturated hydrocarbon radical of 2 to 30 carbon atoms, and each R D is an independently selected divalent hydrocarbon radical of 2 to 30 carbon atoms; (B) a polyorganohydrogensiloxane having at least two silicon-bonded hydrogen atoms per molecule; and (C) a hydrosilylation reaction catalyst; and (D) a polyorganosiloxane having at least two silicon-bonded aliphatic unsaturated groups per molecule; (E) a solvent; (F) a hydrosilylation reaction inhibitor; and Includes.

[0093] In the second embodiment, in the (A) polysiloxane, each R M is an alkyl group of 1 to 6 carbon atoms, and each R U is an alkenyl group of 2 to 6 carbon atoms, and each R D is an alkylene group of 2 to 6 carbon atoms and the subscripts have values ​​of 30≧a≧90, 40≧b≧120, 16≧(c+d)≧1, and 18≧e≧2.

[0094] In a third embodiment, the hydrosilylation reaction inhibitor comprises an acetylenic alcohol, for example, methylbutynol.

[0095] In a fourth embodiment, the solvent comprises an aromatic hydrocarbon, an aliphatic hydrocarbon, or a combination thereof.

[0096] In a fifth embodiment, the polyorganohydrogensiloxane having at least two silicon-bonded hydrogen atoms per molecule has the average formula (R 6 3SiO 1 / 2 ) hh (R 5 2SiO 2 / 2 ) ii (R5HSiO 2 / 2 ) jj [In the formula, each R 5 are independently selected monovalent hydrocarbon or monovalent halogenated hydrocarbon groups, and each R 6 are independently hydrogen or R 5 and the subscript hh is from 2 to 10 (alternatively 2), the subscript ii is from 0 to 1000 (alternatively 0), and the subscript jj is from 2 to 500 (alternatively 2 to 100).

[0097] In a sixth embodiment, the hydrosilylation reaction catalyst comprises a complex of platinum and an organopolysiloxane.

[0098] In a seventh embodiment, the polyorganosiloxane having at least two silicon-bonded aliphatically unsaturated groups per molecule has the average formula: 4” 3SiO1 / 2 ) m (R 4” 2SiO 2 / 2 ) n (R 4’ R 4” SiO 2 / 2 ) o (R 4” 2R 4’ SiO 1 / 2 ) p [In the formula, R 4 As defined above, each R 4” is independently selected from a monovalent hydrocarbon group free of aliphatic unsaturation or a monovalent halogenated hydrocarbon group free of aliphatic unsaturation; each R 4’ are independently selected from a monovalent aliphatic unsaturated hydrocarbon group or a monovalent halogenated aliphatic unsaturated hydrocarbon group, the subscript m is 0 to 10 (alternatively 0), the subscript n is 0 to 1,000, the subscript o is 2 to 500, and the subscript p is 2 to 10 (alternatively 2), with the proviso that the number (m+p) is ≧2.

[0099] In an eighth embodiment, the release coating composition of one of the embodiments further comprises: (G) an anchor additive, (H) an anti-mist additive, and (I) an additional starting material selected from the group consisting of both (G) and (H).

[0100] In a ninth embodiment, the release coating composition of any one of the first through eighth embodiments has, based on the combined weight of the starting materials (A), (B), (C), (D), (E), and (F), respectively, from 1% to 75% by weight of (A) a polysiloxane, from 0.1% to 5% by weight of (B) a polyorganohydrogensiloxane, from 5 ppmw to 300 ppmw of a platinum group metal to the release coating composition, from 20% to 98% by weight of (D) an organopolysiloxane having at least two silicon-bonded aliphatically unsaturated groups per molecule, from 0 to 70% by weight of (E) a solvent, and from 0.002% to 0.15% by weight of (F) a hydrosilylation reaction inhibitor.

[0101] In a tenth embodiment, a method for forming a release liner includes: 1) applying a release coating composition according to any one of embodiments 1 to 9 onto a surface of a substrate, and optionally 2) treating the substrate prior to applying the release coating composition, and, optionally, 3) removing all or a portion of the solvent; and 4) curing the release coating composition to form a release coating on the substrate.

[0102] In an eleventh embodiment, the release liner is prepared by the method described in the tenth embodiment.

[0103] In an eleventh embodiment, the release liner substrate comprises PET.

Claims

1. (A) Unit Formula: 【Chemistry 1】 [In the formula, Each R Ｍ is an independently selected monovalent hydrocarbon group of 1 to 30 carbon atoms free of aliphatic unsaturation, Each R Ｕ is an independently selected monovalent aliphatic unsaturated hydrocarbon group of 2 to 30 carbon atoms; Each R Ｄ is an independently selected divalent hydrocarbon radical of 2 to 30 carbon atoms; The subscript a is 90≧a≧30; The subscript b is 120≧b≧40; Subscript c≧1, Subscript d≧1, The numerical value (c+d) is 16≧(c+d)≧2, Subscript e≦20, Subscript q > 0, Subscript r >= 0; The values ​​(q+r) are sufficient to provide polysiloxanes with a silanol content of up to 1.7% by weight. A polysiloxane comprising: (B) a polyorganohydrogensiloxane having at least two silicon-bonded hydrogen atoms per molecule; (C) a hydrosilylation reaction catalyst; and (D) a polyorganosiloxane having at least two silicon-bonded aliphatically unsaturated groups per molecule; (E) optionally a solvent; (F) a hydrosilylation reaction inhibitor; and A release coating composition comprising: based on the combined weight of starting materials (A), (B), (C), (D), (E), and (F), respectively. (A) the polysiloxane is present in an amount of from 1% to 75% by weight; (B) the polyorganohydrogensiloxane is present in an amount of 0.1% to 5% by weight; (C) the hydrosilylation reaction catalyst is present in a catalytically effective amount sufficient to catalyze a hydrosilylation reaction; (D) the polyorganosiloxane having at least two silicon-bonded aliphatically unsaturated groups per molecule is present in an amount of from 20% to 98% by weight; (E) the solvent is present in an amount of 0 to 98% by weight; (F) the hydrosilylation reaction inhibitor is present in an amount of 0.002% to 0.15% by weight; Release coating composition.

2. Each R Ｍ is an alkyl group of 1 to 6 carbon atoms, and each R Ｕ is an alkenyl group of 2 to 6 carbon atoms, and each R Ｄ 2. The release coating composition of claim 1, wherein is an alkylene group of 2 to 6 carbon atoms and the subscripts have values ​​of 90≧a≧30, 120≧b≧40, 16≧(c+d)≧3, and 18≧e≧2.

3. 10. The release coating composition of claim 1, wherein the hydrosilylation reaction inhibitor comprises an acetylenic alcohol.

4. The polyorganohydrogensiloxane having at least two silicon-bonded hydrogen atoms per molecule has the average formula (R ６ ３ SiO １／２ ) ｈｈ (R ５ ２ SiO ２／２ ) ｉｉ (R ５ HSiO ２／２ ) ｊｊ [In the formula, each R ５ are independently selected monovalent hydrocarbon or monovalent halogenated hydrocarbon groups, and each R ６ are independently hydrogen or R ５ and subscript hh is from 2 to 10, subscript ii is from 0 to 1000, and subscript jj is from 2 to 500.

5. 10. The release coating composition of claim 1 further comprising an additional starting material selected from the group consisting of: (G) an anchor additive; (H) an anti-mist additive; and (I) both (G) and (H).

6. 6. The release coating composition of claim 5, wherein the solvent comprises an aromatic hydrocarbon, an aliphatic hydrocarbon, or a combination thereof.

7. 7. The release coating composition of any one of claims 1 to 6, wherein the molar ratio of silicon-bonded hydrogen atoms to silicon-bonded aliphatically unsaturated groups of the combined starting materials (A), (B), (C), and (D) is from 1:1 to 2.5:

1.

8. 1. A method for forming a release liner, comprising: 1) applying a release coating composition according to any one of claims 1 to 7 onto a surface of a substrate, and optionally 2) treating the substrate prior to applying the release coating composition; 3) removing all or a portion of the solvent; and 4) heating the release coating composition, thereby curing the release coating composition to form a release coating on the substrate; and A method comprising:

9. A release liner prepared by the method of claim 8.

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