WO2023146692A1

WO2023146692A1 - Pressure sensitive adhesive composition and methods for its preparation and use in flexible organic light emitting diode applications

Info

Publication number: WO2023146692A1
Application number: PCT/US2022/080096
Authority: WO
Inventors: Bona Kim; Juyoung YOOK
Original assignee: Dow Silicones Corporation
Priority date: 2022-01-26
Filing date: 2022-11-18
Publication date: 2023-08-03
Also published as: JP2025504394A; KR20240139602A; CN118541457A

Abstract

A pressure sensitive adhesive composition can cure via hydrosilylation to form a pressure sensitive adhesive. The pressure sensitive adhesive composition may be coated on a substrate and cured to form a protective film. The protective film is useful in flexible OLED device fabrication processes, e.g., for protection of passivation layers and/or thin film encapsulation layers.

Description

PRESSURE SENSITIVE ADHESIVE COMPOSITION AND METHODS FOR ITS

PREPARATION AND USE IN FLEXIBLE ORGANIC LIGHT EMITTING DIODE

APPLICATIONS

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Patent Application Serial No. 63/303,143 filed on 26 January 2022 under 35 U.S.C. §119 (e). U.S. Provisional Patent Application Serial No. 63/303,143 is hereby incorporated by reference.

TECHNICAL FIELD

[0002] This invention relates to a pressure sensitive adhesive composition that is useful in processes for fabricating flexible organic light emitting diode (OLED) displays. The pressure sensitive adhesive composition cures to form a pressure sensitive adhesive with low initial adhesion, high adhesion stability over time, low migration, anti-scratch, and/or restorability properties.

BACKGROUND

[0003] In a typical process for fabricating a flexible OLED display, an OLED is formed on a relatively rigid substrate (e.g., glass or glass coated with a polyimide varnish), and a passivation layer is formed on the surface of the OLED opposite the substrate. During further processing, the rigid substrate is removed. Weak or brittle layers need to be protected from damage (e.g. , scratches or other shocks) during the further processing.

[0004] To protect the layers during the fabrication process, a protective film with low adhesion is desired to prevent delamination of a fragile layer (e.g., passivation layer or thin film encapsulation layer) on a surface of an OLED module during releasing of the protective film after use. If adhesion control fails and adhesion increase with time (i.e., during the fabricating process), the layer may delaminate or be damaged when the protective film is removed. Therefore, there is an industry need to provide protective films with low adhesion and high adhesion stability (where adhesion does not increase during the time needed for the fabrication process to an extent that would cause delamination or damage).

[0005] It is also important that the surface of the layer remain clean such that additional films or layers can be laminated thereto after removal of the protective film. Therefore, there is an industry need to provide a protective film with low migration (such that no or minimal amounts of adhesive from the protective film remain on the surface of the layer in the flexible OLED device after the protective film is removed.

BRIEF SUMMARY OF THE INVENTION

[0006] A pressure sensitive adhesive composition comprises an alkenyl containing polydialkylsiloxane gum, an alkenyl containing polydialkylsiloxane polymer, a polyalkylhydrogensiloxane, a platinum group metal catalyst, an acetylenic alcohol, and an organic solvent.

[0007] A method for preparing the pressure sensitive adhesive composition, a method of using the pressure sensitive adhesive composition to form a pressure sensitive adhesive article, and a method for fabricating a flexible organic light emitting diode device using the pressure sensitive adhesive article are also disclosed.

DETAILED DESCRIPTION OF THE INVENTION

[0008] The pressure sensitive adhesive composition introduced above comprises:

(A) a first alkenyl containing polydialkylsiloxane gum, where the first alkenyl containing polydialkylsiloxane gum has silicon bonded alkyl groups with 1 to 10 carbon atoms and silicon bonded alkenyl groups with 2 to 6 carbon atoms, and where the vinyl functionalities (i.e., CH2=CH- in silicone bonded alkenyl groups) are present in an amount of 0.03 weight % to 0.11 weight % based on the weight of the first alkenyl containing polydialkylsiloxane gum; optionally (B) a second alkenyl containing polydialkylsiloxane gum, where the second alkenyl containing poly dialkylsiloxane gum has silicon bonded alkyl groups with 1 to 10 carbon atoms and silicon bonded alkenyl groups with 2 to 6 carbon atoms, and where the vinyl functionalities are present in an amount of 0.3 weight % to 1.1 weight % based on the weight of the second alkenyl containing polydialkylsiloxane gum; where starting materials (A) and (B) are present in amounts sufficient to provide a weight ratio calculated by (B)/[(A) + (B)] of 0 to 0.5;

(C) an alkenyl containing polydialkylsiloxane polymer, where the alkenyl containing polydialkylsiloxane polymer has silicon bonded alkyl groups with 1 to 10 carbon atoms and silicon bonded alkenyl groups with 2 to 6 carbon atoms, and where the vinyl functionalities are present in an amount of 0.01 weight % to 2 weight % based on the weight of the alkenyl containing polydialkylsiloxane polymer; where starting materials (A), (B), and (C) are present in amounts to provide a weight ratio calculated by [(A) + (B)]/(C) of 0.5 to 2.5;

(D) a polyalkylhydrogensiloxane having silicon bonded alkyl groups with 1 to 10 carbon atoms and having at least three silicon bonded hydrogen atoms per molecule, and having an average of at least 1 weight % silicon bonded hydrogen atoms,

(E) a platinum group metal catalyst;

(F) an acetylenic alcohol; optionally (G) an anchorage additive; and

(H) an organic solvent; with the proviso that all starting materials in the composition combined have a molar ratio of silicon bonded hydrogen atoms (SiH) I silicon bonded alkenyl groups (Vi) [SiH/Vi ratio] of 3.33 to 5.21.

(A) First (low) alkenyl containing polydialkylsiloxane gum

[0009] Starting material (A) in the pressure sensitive adhesive composition is a first alkenyl containing polydialkylsiloxane gum. The first alkenyl containing polydialkylsiloxane gum has silicon bonded alkyl groups with 1 to 10 carbon atoms and silicon bonded alkenyl groups with 2 to 6 carbon atoms. The vinyl (CH2=CH-) functionalities (e.g., in the silicon bonded alkenyl group) are present in an amount of 0.03 weight % to 0.11 weight % based on the weight of the first alkenyl containing polydialkylsiloxane gum. Alternatively, (A) the first alkenyl containing polydialkylsiloxane gum may have 0.05 weight % to 0.09 weight % vinyl functionalities.

[0010] Starting material (A), the first alkenyl containing polydialkylsiloxane gum, may have unit formula (I): (R¹2R²SiOi/2)d(R¹3SiOi/2)e(R¹R²SiO2/2)f(R¹2SiO2/2)g, where each R¹ is independently an alkyl group of 1 to 10 carbon atoms; each R² is independently an alkenyl group of 2 to 6 carbon atoms; subscripts d, e, f, and g represent average numbers of each unit in the unit formula and have values such that 2 > d > 0, 2 > e > 0, 20 > f > 5, 10,000 > g > 2,000, and a quantity (d + e) = 2. Alternatively, subscript d may be 2, and subscript e may be 0. Alternatively, subscript f may be 5 to 15. Alternatively, subscript g may be 6,000 to 8,000; alternatively 6,500 to 7,500.

[0011] In unit formula (I), each R¹ is independently an alkyl group of 1 to 10 carbon atoms and each R² is independently an alkenyl group of 2 to 6 carbon atoms. Suitable alkyl groups include branched or unbranched, saturated monovalent hydrocarbon groups. Alkyl is exemplified by, but not limited to, 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 saturated monovalent hydrocarbon groups of 6 to 10 carbon atoms. Alternatively, each R¹ may be selected from methyl, ethyl, and isopropyl. Alternatively, each R¹ may be methyl. Suitable alkenyl groups include branched or unbranched monovalent hydrocarbon groups having a terminal double bond (a vinyl functionality). Alkenyl is exemplified by, but not limited to, vinyl, allyl, butenyl (e.g., isobutenyl, n-butenyl, tert-butenyl and/or sec-butenyl), and hexenyl, including branched and linear groups of 6 carbon atoms. Alternatively, each R² may have formula CH2=CH-(CH2)_S-, where subscript s is 0 to 4 (i.e., either vinyl, when s = 0 or vinyl-terminated when s > 0). Alternatively, each R² may be vinyl, allyl, or hexenyl. Alternatively, each R² may be vinyl or hexenyl. Alternatively, each R² may be vinyl.

[0012] Starting material (A) is exemplified by i) bis-vinyldimethylsiloxy-terminated polydimethylsiloxane, ii) bis-vinyldimethylsiloxy-terminated poly(dimethylsiloxane/methylvinylsiloxane), iii) bis-vinyldimethylsiloxy-terminated polymethylvinylsiloxane, iv) bis-trimethylsiloxy-terminated poly(dimethylsiloxane/methylvinylsiloxane), v) bis-trimethylsiloxy-terminated polymethylvinylsiloxane, vi) bis-hexenyldimethylsiloxy-terminated polydimethylsiloxane, vii) bis-hexenyldimethylsiloxy-terminated poly (dimethylsiloxane/methylhexenylsiloxane) , viii) bis-hexenyldimethylsiloxy-terminated polymethylhexenylsiloxane, ix) bis-trimethylsiloxy-terminated poly(dimethylsiloxane/methylhexenylsiloxane), x) bis-trimethylsiloxy-terminated polymethylhexenylsiloxane, xi) bis-hexenyldimethyl-siloxy terminated poly(dimethylsiloxane/methylvinylsiloxane), xii) bis-vinyldimethylsiloxy-terminated poly(dimethylsiloxane/methylhexenylsiloxane) xii) a combination of two or more of i), ii), iii), iv), v), vi), vii), viii), ix), x), xi), and xii). [0013] Methods of preparing alkenyl-containing polydialkylsiloxanes suitable for use as starting material (A) such as hydrolysis and condensation of the corresponding organohalosilanes or equilibration of cyclic polydiorganosiloxanes, are well known in the art, see for example U.S. Patents 3,284,406; 4,772,515; 5,169,920; 5,317,072; and 6,956,087. [0014] The amount of (A) the first alkenyl containing polydialkylsiloxane gum depends on various factors such as the exact content of alkenyl groups in starting material (A), whether starting material (B) is present, and whether any other starting materials contain alkenyl groups (e.g., (C) the alkenyl containing poly dialkylsiloxane polymer and/or the platinum group metal catalyst). However, the amount of starting material (A) may be at least 57 weight parts, alternatively at least 60 weight parts, alternatively at least 65 weight parts, alternatively at least 70 weight parts, and alternatively at least 71 weight parts; while at the same time the amount of starting material (A) may be up to 100 weight parts, alternatively up to 90 weight parts, alternatively up to 80 weight parts, alternatively up to 75 weight parts, and alternatively up to 71 weight parts.

(B) Second (high) alkenyl containing poly dialkylsiloxane gum [0015] Starting material (B) in the pressure sensitive adhesive composition is a second alkenyl containing polydialkylsiloxane gum that differs from the first alkenyl containing polydiorganosiloxane gum at least in that it has a higher content of vinyl functionalities. The second alkenyl containing poly dialkylsiloxane gum has silicon bonded alkyl groups with 1 to 10 carbon atoms and silicon bonded alkenyl groups with 2 to 6 carbon atoms. The vinyl functionalities are present in an amount of 0.3 weight % to 1.1 weight % based on the weight of the second alkenyl containing polydialkylsiloxane gum. Alternatively, (B) the second alkenyl containing polydialkylsiloxane gum may have 0.5 weight % to 0.9 weight % vinyl functionality. [0016] Starting material (B), the second alkenyl containing poly dialkylsiloxane gum, may have unit formula (II): (R¹2R²SiOi/2)h(R¹3SiOi/2)i(R¹R²SiO2/2)j(R¹2SiO2/2)k, where each R¹ is independently an alkyl group of 1 to 10 carbon atoms as described above; each R² is independently an alkenyl group of 2 to 6 carbon atoms as described above; subscripts h, i, j, and k represent average numbers of each unit in the unit formula and have values such that 2 > h > 0, 2 > i > 0, 100 > j > 21, 10,000 > k > 2,000, and a quantity (h + i) = 2. Alternatively, in formula (II), subscript] may be 50 to 150. Alternatively, subscript k may be 5,000 to 7,000.

[0017] Starting material (B) is exemplified by i) bis-vinyldimethylsiloxy-terminated polydimethylsiloxane, ii) bis-vinyldimethylsiloxy-terminated poly(dimethylsiloxane/methylvinylsiloxane), iii) bis-vinyldimethylsiloxy-terminated polymethylvinylsiloxane, iv) bis-trimethylsiloxy-terminated poly(dimethylsiloxane/methylvinylsiloxane), v) bis-trimethylsiloxy-terminated polymethylvinylsiloxane, vi) bis-hexenyldimethylsiloxy-terminated polydimethylsiloxane, vii) bis-hexenyldimethylsiloxy-terminated poly (dimethylsiloxane/methylhexenylsiloxane) , viii) bis-hexenyldimethylsiloxy-terminated polymethylhexenylsiloxane, ix) bis-trimethylsiloxy-terminated poly(dimethylsiloxane/methylhexenylsiloxane), x) bis-trimethylsiloxy-terminated polymethylhexenylsiloxane, xi) bis-hexenyldimethyl-siloxy terminated poly(dimethylsiloxane/methylvinylsiloxane), xii) bis-vinyldimethylsiloxy-terminated poly(dimethylsiloxane/methylhexenylsiloxane) xii) a combination of two or more of i), ii), iii), iv), v), vi), vii), viii), ix), x), xi), and xii).

[0018] Methods of preparing alkenyl-containing polydialkylsiloxanes suitable for use as starting material (B) such as hydrolysis and condensation of the corresponding organohalosilanes or equilibration of cyclic polydiorganosiloxanes, are well known in the art, see for example U.S. Patents 3,284,406; 4,772,515; 5,169,920; 5,317,072; and 6,956,087.

[0019] The amount of (B) the second alkenyl containing polydialkylsiloxane gum depends on various factors such as the exact content of alkenyl groups in starting material (B), the amount and alkenyl content of starting material (A) present, and whether any other starting materials contain alkenyl groups (e.g., the platinum group metal catalyst). However, the amount of starting material (B) may be 0 (because starting material (B) is optional). Alternatively, when (B) is present, the amount of (B) may be at least 25 weight parts, alternatively at least 26 weight parts, alternatively at least 27 weight parts, alternatively at least 28 weight parts, and alternatively at least 29 weight parts; while at the same time the amount of starting material (A) may be up to 43 weight parts, alternatively up to 40 weight parts, alternatively up to 35 weight parts, alternatively up to 30 weight parts, and alternatively up to 29 weight parts. The amounts of starting materials (A) and (B) combined may total 100 weight parts in the pressure sensitive adhesive composition. Starting materials (A) and (B) are present in the pressure sensitive adhesive composition in amounts sufficient to provide a weight ratio calculated by (B)/[(A) + (B)] of 0 to 0.5, alternatively 0 to 0.43, alternatively > 0 to 0.5, alternatively > 0 to 0.43, alternatively 0.25 to 0.43. Alternatively, the weight ratio (B)/[(A) + (B)] may be at least 0.25, alternatively at least 0.28 while at the same time, the weight ratio (B)/[(A) + (B)] may be up to 0.5, alternatively up to 0.43, and alternatively up to 0.29.

(C) Alkenyl containing polydialkylsiloxane polymer

[0020] Starting material (C) in the pressure sensitive adhesive composition is an alkenyl containing polydialkylsiloxane polymer, which differs from the gums (A) and (B) at least in that the average number of siloxane units per molecule is lower. The alkenyl containing polydialkylsiloxane polymer has silicon bonded alkyl groups with 1 to 10 carbon atoms and silicon bonded alkenyl groups with 2 to 6 carbon atoms. The vinyl functionalities are present in an amount of 0.01 weight % to 2 weight % based on the weight of the alkenyl containing polydialkylsiloxane polymer.

[0021] Starting material (C), the alkenyl containing polydialkylsiloxane polymer, may have unit formula (III): (R¹2R²SiOi/2)r(R¹3SiOi/2)_m(R¹R²SiO2/2)n(R¹2SiO2/2)o, where each R¹ is independently an alkyl group of 1 to 10 carbon atoms as described above; each R² is independently an alkenyl group of 2 to 6 carbon atoms as described above; subscripts i, m, n, and o represent average number of each unit in the unit formula and have values such that 2 > r > 0, 2 > m > 0, 100 > n > 0, 1,000 > o > 10, and a quantity (r + m) = 2. Alternatively, in unit formula (III), subscript r may be 2 and subscript m may be 0. Alternatively, subscript o may be 400 to 1,000; alternatively 450 to 950. Alternatively, subscript n may be 0.

[0022] Starting material (C) is exemplified by i) bis-vinyldimethylsiloxy-terminated polydimethylsiloxane, ii) bis-vinyldimethylsiloxy-terminated poly(dimethylsiloxane/methylvinylsiloxane), iii) bis-vinyldimethylsiloxy-terminated polymethylvinylsiloxane, iv) bis-trimethylsiloxy-terminated poly(dimethylsiloxane/methylvinylsiloxane), v) bis-trimethylsiloxy-terminated polymethylvinylsiloxane, vi) bis-hexenyldimethylsiloxy-terminated polydimethylsiloxane, vii) bis-hexenyldimethylsiloxy-terminated poly (dimethylsiloxane/methylhexenylsiloxane) , viii) bis-hexenyldimethylsiloxy-terminated polymethylhexenylsiloxane, ix) bis-trimethylsiloxy-terminated poly(dimethylsiloxane/methylhexenylsiloxane), x) bis-trimethylsiloxy-terminated polymethylhexenylsiloxane, xi) bis-hexenyldimethyl-siloxy terminated poly(dimethylsiloxane/methylvinylsiloxane), xii) bis-vinyldimethylsiloxy-terminated poly(dimethylsiloxane/methylhexenylsiloxane) xii) a combination of two or more of i), ii), iii), iv), v), vi), vii), viii), ix), x), xi), and xii). [0023] Methods of preparing alkenyl-containing polydialkylsiloxanes suitable for use as starting material (B) such as hydrolysis and condensation of the corresponding organohalosilanes or equilibration of cyclic polydiorganosiloxanes, are well known in the art, see for example U.S. Patents 3,284,406; 4,772,515; 5,169,920; 5,317,072; and 6,956,087. [0024] The amount of (C) the alkenyl containing polydialkylsiloxane polymer depends on various factors such as the exact content of alkenyl groups in starting material (C), the amount and alkenyl content of starting material (A) present, whether starting material (B) is present, and whether any other starting materials contain alkenyl groups (e.g., the platinum group metal catalyst). However, the amount of starting material (C) may be 0 (because starting material (C) is optional). Alternatively, when (C) is present, the amount of (C) may be > 0 weight parts, alternatively at least 75 weight parts, alternatively at least 80 weight parts, alternatively at least 81 weight parts, alternatively at least 82 weight parts, and alternatively at least 83 weight parts; while at the same time the amount of starting material (C) may be up to 143 weight parts, alternatively up to 140 weight parts, alternatively up to 135 weight parts, alternatively up to 130 weight parts, and alternatively up to 125 weight parts. The amounts of starting materials (A), (B), and (C) may be such that a weight ratio calculated by [(A) + (B)]/(C) is at least 0.5, alternatively at least 0.6, alternatively at least 0.7, and alternatively at least 1.2, while at the same time the weight ratio calculated by [(A) + (B)]/(C) may be up to 2.5, alternatively up to 1.5, and alternatively up to 1.3.

(D) Polyalkylhydrogensiloxane

[0025] Starting material (D) in the pressure sensitive adhesive composition is a polyalkylhydrogensiloxane. The polyalkylhydrogensiloxane has silicon bonded alkyl groups with 1 to 10 carbon atoms and having at least three silicon bonded hydrogen atoms per molecule, and having an average of at least 1 weight % silicon bonded hydrogen atoms.

[0026] Starting material (D), the polyalkylhydrogensiloxane may have unit formula (IV): (R¹3SiOi/2)3(R¹2SiO2/2)p(R¹HSiO₂/2)q, where each R¹ is independently an alkyl group of 1 to 10 carbon atoms as described above; subscripts p and q represent average number of each difunctional unit in the unit formula and have values such that 0 < p < 2,000 and 2 < q < 2000. Alternatively, subscript p may be 0. Alternatively, subscript q may be 15 to 50, alternatively 20 to 45, alternatively 25 to 40, and alternatively 30 to 35.

[0027] Polyalkylhydrogensiloxanes for starting material (D) are exemplified by: a) bis-dimethylhydrogensiloxy-terminated poly(dimethylsiloxane/methylhydrogensiloxane), b) bis-dimethylhydrogensiloxy-terminated polymethylhydrogensiloxane, c) bis-trimethylsiloxy-terminated poly(dimethylsiloxane/methylhydrogensiloxane), d) bis-trimethylsiloxy-terminated polymethylhydrogensiloxane, and e) a combination of two or more of a), b), c), and d).

[0028] Methods of preparing linear, branched, and cyclic polyalkylhydrogensiloxanes suitable for use as starting material (D), such as hydrolysis and condensation of alkylhalosilanes, are well known in the art, as exemplified in U.S. Patent 2,823,218 to Speier, U.S. Patent 3,957,713 to Jeram et al. and U.S. Patent 4,329,273 to Hardman, et al.

[0029] The amount of (D) the polyalkylhydrogensiloxane polymer depends on various factors such as the alkenyl contents and amounts of starting materials (A), (B), and (C) present, and whether any other starting materials contain alkenyl groups (e.g., the platinum group metal catalyst). However, the amount of starting material (D) may be sufficient to the silicone pressure sensitive adhesive composition with an overall SiH/Vi ratio, i.e., provide starting materials in the composition that combined have a molar ratio of silicon bonded hydrogen atoms (SiH) I silicon bonded alkenyl groups (Vi), of 3.3 to 5.21; alternatively 3.8 to 5.1; alternatively 4.1 to 4.8; and alternatively 4.2 to 4.3. Alternatively overall SiH/Vi ratio may be at least 3.33, alternatively at least 3.8, alternatively at least 4.0; alternatively at least 4.1, and alternatively at least 4.2; while at the same time, overall SiH/Vi ratio may be up to 5.21, alternatively up to 5.1, alternatively up to 5.0; alternatively up to 4.8; alternatively up to 4.5; and alternatively up to 4.3. Alternatively, the polyalkylhydrogensiloxane may be present in the pressure sensitive adhesive composition in an amount of 4 weight parts to 10 weight parts.

(E) Platinum group metal catalyst

[0030] The pressure sensitive adhesive composition further comprises a platinum group metal catalyst capable of catalyzing hydrosilylation. Suitable platinum group metal catalysts are known in the art and are commercially available. The catalyst can be a platinum group metal selected from platinum, rhodium, ruthenium, palladium, osmium, and iridium. Alternatively, the catalyst may be a compound of such a metal, for example, chloroplatinic acid, chloroplatinic acid hexahydrate, platinum dichloride, and complexes of said compounds with alkenyl- functional organopolysiloxanes or platinum compounds microencapsulated in a matrix or core/shell type structure. Complexes of platinum with alkenyl-functional organopolysiloxanes include l,3-diethenyl-l,l,3,3 -tetramethyldisiloxane complexes with platinum. These complexes may be microencapsulated in a resin matrix. Exemplary hydrosilylation catalysts are described in U.S. Patents 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 EP 0 347 895 B. Microencapsulated hydrosilylation catalysts and methods of preparing them are known in the art, as exemplified in U.S. Patents 4,766,176 and 5,017,654.

[0031] The catalyst is added to the pressure sensitive adhesive composition in an amount sufficient to catalyze hydrosilylation reaction, typically an amount sufficient to provide 10 ppm to 5,000 ppm by weight of platinum group metal based on combined weights of all starting materials in the pressure sensitive adhesive composition, excluding solvent. Alternatively, when the platinum group metal catalyst comprises a compound or complex of platinum with an alkenyl-functional organopolysiloxane, e.g., 1,3-diethenyl-l, 1,3,3 -tetramethyldisiloxane complexes with platinum, the amount may be 5 weight parts to 10 weight parts, alternatively 6 weight parts to 7.5 weight parts.

(F) Acetylenic alcohol

[0032] The pressure sensitive adhesive composition further comprises an acetylenic alcohol. The acetylenic alcohol may be added as an inhibitor or stabilizer for the pressure sensitive adhesive composition. Suitable acetylenic alcohols are exemplified by methyl butynol, ethynyl cyclohexanol (ETCH), dimethyl hexynol, and 3,5-dimethyl-l-hexyn-3-ol, l-butyn-3-ol, 1- propyn-3-ol, 2-methyl-3-butyn-2-ol, 3-methyl-l-butyn-3-ol, 3 -methyl- l-pentyn-3-ol, 3-phenyl- l-butyn-3-ol, 4-ethyl-l-octyn-3-ol, 3,5-dimethyl-l-hexyn-3-ol, and 1 -ethynyl- 1 -cyclohexanol, and a combination thereof. Alternatively, starting material (F) may be selected from the group consisting of (F-l) 1 -ethynyl- 1 -cyclohexanol, (F-2) methyl butynol, (F-3) diallyl maleate, and (F-4) a combination of two or more of (F-l), (F-2) and (F-3). Alternatively, starting material (F) is exemplified by ETCH. Acetylenic alcohols are commercially available from various sources, such as Sigma- Aldrich, Inc. of St. Eouis, Missouri, USA.

[0033] The amount of acetylenic alcohol added to the composition will depend on various factors including the desired pot life of the pressure sensitive adhesive composition, whether the composition will be a one part composition or a multiple part composition, the particular acetylenic alcohol used, and the selection and amount of the polyalkylhydrogensiloxane. However, when present, the amount of starting material (F) may be 0.01 to 0.5 parts by weight.

(G) Anchorage additive

[0034] The pressure sensitive adhesive composition may optionally include an anchorage additive. Without wishing to be bound by theory, it is thought that the anchorage additive will facilitate bonding to a substrate by a pressure sensitive adhesive prepared by curing the pressure sensitive adhesive composition described herein. However, the presence of the anchorage additive will not detrimentally affect the desired peel force allowing the pressure sensitive adhesive to be removed from an electronic device, such as a fragile layer in an OEED, without damaging the device or leaving significant residue.

[0035] Suitable anchorage additives include silane coupling agents such as methyltrimethoxysilane, vinyltrimethoxysilane, allyltrimethoxysilane, 3- methacryloxypropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3- aminopropyltrimethoxysilane, bis(trimethoxysilyl)propane, and bis(trimethoxysilyl)hexane; and mixtures or reaction mixtures of said silane coupling agents. Alternatively, the anchorage additive may be tetramethoxysilane, tetraethoxysilane, dimethyldimethoxysilane, methylphenyldimethoxysilane, methylphenyldiethoxysilane, phenyltrimethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, vinyltriethoxysilane, allyltriethoxysilane, 3- glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, -(3,4- epoxycyclohexyl)ethyltrimethoxysilane or 3-methacryloxypropyl trimethoxysilane.

[0036] Alternatively, the anchorage additive may be exemplified by a reaction product of an alkenyl-functional alkoxysilane (e.g., a vinyl alkoxysilane) and an epoxy-functional alkoxysilane; a reaction product of an alkenyl-functional acetoxysilane (such as vinyl acetoxysilane) and epoxy-functional alkoxysilane; and a combination (e.g., physical blend and/or a reaction product) of a polyorganosiloxane having at least one aliphatically unsaturated hydrocarbon group and at least one hydrolyzable group per molecule and an epoxy-functional alkoxy silane (e.g., a combination of a hydroxy-terminated, vinyl functional poly dimethylsiloxane with glycidoxypropyl trimethoxy silane). Suitable anchorage additives and methods for their preparation are disclosed, for example, in U.S. Patent 9,562,149; U.S. Patent Application Publication Numbers 2003/0088042, 2004/0254274, 2005/0038188, 2012/0328863 at paragraph [0091], and U.S. Patent Publication 2017/0233612 at paragraph [0041]; and EP 0 556023.

[0037] Anchorage additives are commercially available. For example, SYL-OFF™ 297, SYU-OFF™ 397, and SYU-OFF™ 9176 are available from Dow Silicones Corporation of Midland, Michigan, USA. Other exemplary anchorage additives include (G-l) vinyltriacetoxysilane, (G-2) glycidoxypropyltrimethoxysilane, (G-3) 2-(3,4- epoxycyclohexyl)ethyltrimethoxysilane, (G-4) a combination of two or more of (G-l), (G-2) and (G-3); and (G-5) a combination of any of (G-l), (G-2), (G-3) and/or (G-4), and a polydimethylsiloxane terminated with hydroxyl groups, methoxy groups, or terminated with both a hydroxy group and a methoxy group. The combinations (G-4) and (G-5) may be physical blends and/or reaction products.

[0038] The amount of anchorage additive depends on various factors including the type of substrate to which the composition will be applied and whether a primer or other surface treatment will be used before application of the composition. However, the amount of anchorage additive may be 0 to 5 weight parts, alternatively 1 weight part to 5 weight parts.

(H) Organic Solvent [0039] The pressure sensitive adhesive composition further comprises a solvent. The solvent can be an organic solvent. The organic solvent can be an alcohol such as methanol, ethanol, isopropanol, butanol, or n-propanol; a ketone such as acetone, methylethyl ketone, or methyl isobutyl ketone; an aromatic hydrocarbon such as benzene, toluene, or xylene; an aliphatic hydrocarbon such as heptane, hexane, or octane; a glycol ether such as propylene glycol methyl ether, dipropylene glycol methyl ether, propylene glycol n-butyl ether, propylene glycol n- propyl ether, or ethylene glycol n-butyl ether, a halogenated hydrocarbon such as dichloromethane, 1,1,1 -trichloroethane or methylene chloride; chloroform; dimethyl sulfoxide; dimethyl formamide, acetonitrile; tetrahydrofuran; white spirits; mineral spirits; naphtha; n- methyl pyrrolidone; or a combination thereof. Alternatively, the solvent may be selected from the group consisting of benzene, toluene, heptane, ethylbenzene, xylene, and a combination of two or more thereof.

[0040] The amount of solvent will depend on various factors including the type of solvent selected and the amount and type of other starting materials selected for the pressure sensitive adhesive composition. However, the amount of solvent may range from 10 % to 90 %, alternatively 20% to 60 %, based on combined weights of all starting materials in the pressure sensitive adhesive composition. The solvent can be added during preparation of the pressure sensitive adhesive composition, for example, to aid mixing and delivery. All or a portion of the solvent may be added with one of the other starting materials. For example, one or more of the gum(s), the polymer, and the catalyst may be dissolved in a solvent, such as an aromatic hydrocarbon or an alcohol before combination with the other starting materials in the composition. All or a portion of the solvent may optionally be removed after the pressure sensitive adhesive composition is prepared.

[0041] When selecting starting materials for the pressure sensitive adhesive composition described above, there may be overlap between types of starting materials because certain starting materials described herein may have more than one function. For example, certain alkoxy silanes may be useful as adhesion promoters and anchorage additives. When adding additional starting materials to the composition, the additional starting materials are distinct from one another and from the required starting materials in the composition.

[0042] The pressure sensitive adhesive composition may be free of silicone resin, such as polyorganosilicate resin and/or silsesquioxane resin. “Free of silicone resin” as used herein means the pressure sensitive adhesive composition contains a non-detectable amount of silicone resin or an amount of silicone resin that does not change the properties measured according to Example 2 below as compared to the same composition but without the silicone resin therein. [0043] The pressure sensitive adhesive composition may be free of filler or contain only a limited amount of filler, such as 0 to 30 % based on combined weights of all starting materials in the composition. Without wishing to be bound by theory, it is thought that fillers can agglomerate or otherwise stick to the equipment used to apply or dispense the pressure sensitive adhesive composition, and fillers can hinder optical properties, for example transparency, of the pressure sensitive adhesive composition and of the silicone pressure sensitive adhesive film formed therewith, if optical transparency is desired. The fillers may also be prejudicial to the adherence of the silicone pressure sensitive adhesive film to substrates.

[0044] The pressure sensitive adhesive composition can be prepared by a method comprising combining all starting materials by any convenient means such as mixing at ambient or elevated temperature. The acetylenic alcohol may be added before the platinum group metal catalyst, for example, when the pressure sensitive adhesive composition will be prepared at elevated temperature and/or the pressure sensitive adhesive composition will be prepared as a one part composition.

[0045] Alternatively, the pressure sensitive composition may be prepared as a multiple part composition, for example, when the composition will be stored for a long period of time before use. In the multiple part composition, the platinum group metal catalyst is stored in a separate part from any starting material having a silicon bonded hydrogen atom, for example the polyalkylhydrogensiloxane, and the parts are combined shortly before use of the pressure sensitive adhesive composition. For example, a two part composition may be prepared by combining starting materials comprising one or more of the first alkenyl-containing polydialkylsiloxane gum, the second alkenyl-containing polydialkylsiloxane gum, and the alkenyl containing polydialkylsiloxane polymer; the polyalkylhydrogensiloxane; and the organic solvent, and optionally one or more other additional starting materials described above to form a base part, by any convenient means such as mixing. A curing agent may be prepared by combining starting materials comprising one or more of the first alkenyl-containing polydialkylsiloxane gum, the second alkenyl-containing polydialkylsiloxane gum, and the alkenyl containing polydialkylsiloxane polymer; the platinum group metal catalyst; and the organic solvent, and optionally one or more other additional starting materials described above by any convenient means such as mixing. The starting materials may be combined at ambient or elevated temperature. The acetylenic alcohol may be included in one or more of the base part, the curing agent part, or a separate additional part. The anchorage additive may be added to the base part or may be added as a separate additional part. When a two part composition is used, the weight ratio of amounts of base part to curing agent part may range from 1:1 to 10:1. The pressure sensitive adhesive composition will cure via hydrosilylation reaction to form a pressure sensitive adhesive. [0046] The method described above may further comprise one or more additional steps. The pressure sensitive adhesive composition prepared as described above may be used to form an adhesive article, e.g. , a pressure sensitive adhesive (prepared by curing the pressure sensitive adhesive composition described above) on a substrate. The method described above may, therefore, further comprise comprises applying the pressure sensitive adhesive composition to a substrate.

[0047] Applying the pressure sensitive adhesive curable composition to the substrate can be performed by any convenient means. For example, the pressure sensitive adhesive curable composition may be applied onto a substrate by gravure coater, offset coater, offset-gravure coater, roller coater, reverse-roller coater, air-knife coater, or curtain coater.

[0048] The substrate can be any material that can withstand the curing conditions (described below) used to cure the pressure sensitive adhesive curable composition to form the pressure sensitive adhesive on the substrate. For example, any substrate that can withstand heat treatment at a temperature equal to or greater than 120 °C, alternatively 150 °C is suitable. Examples of materials suitable for such substrates including plastic films such as polyimide (PI), poly etheretherketone (PEEK), polyethylene naphthalate (PEN), liquid-crystal polyarylate, polyamideimide (PAI), poly ether sulfide (PES), or polyethylene terephthalate (PET), or PE (polyethylene), or PP (polypropylene). Alternatively, the substrate may be a metal foil such as aluminum foil or copper foil. The thickness of the substrate is not critical; however, the thickness may range from 5 micrometers to 300 micrometers.

[0049] To improve bonding of the pressure sensitive adhesive to the substrate, the method may optionally further comprise treating the substrate before applying the pressure sensitive adhesive composition. Treating the substrate may be performed by any convenient means, such as applying a primer, or subjecting the substrate to corona-discharge treatment, etching, or plasma treatment before applying the pressure sensitive adhesive composition to the substrate. [0050] An adhesive article such as a protective film may be prepared by applying the pressure sensitive adhesive composition described above onto the substrate described above. The method may optionally further comprise removing all, or a portion, of the solvent before and/or during curing. Removing solvent may be performed by any convenient means, such as heating at a temperature that vaporizes the solvent without fully curing the pressure sensitive adhesive composition, e.g., heating at a temperature of 70 °C to 120 °C, alternatively 50 °C to 100 °C, and alternatively 70 °C to 80 °C for a time sufficient to remove all or a portion of the solvent (e.g., 30 seconds to 1 hour, alternatively 1 minute to 5 minutes).

[0051] The method then further comprises curing the pressure sensitive adhesive composition (which may have some or all of the solvent removed when the drying step is performed) room temperature or by heating at a temperature of 140 °C to 220 °C, alternatively 150 °C to 220 °C, alternatively 160 °C to 200 °C, and alternatively 165 °C to 180 °C for a time sufficient to cure the pressure sensitive adhesive curable composition (e.g., for 30 seconds to an hour, alternatively 1 to 5 minutes). This forms a pressure sensitive adhesive film on the substrate. Drying and/or curing may be performed by placing the substrate in an oven. The amount of the pressure sensitive adhesive composition to be applied to the substrate depends on the specific application, however, the amount may be sufficient such that after curing thickness of the pressure sensitive adhesive may be 5 micrometers to 200 micrometers, and for protective film the thickness may be 10 micrometers to 50 micrometers, alternatively 20 micrometers to 40 micrometers, and alternatively 30 micrometers.

[0052] The method described herein may optionally further comprise applying a removable release liner to a surface of the pressure sensitive adhesive film opposite the substrate, e.g., to protect the pressure sensitive adhesive before use of the adhesive article.

[0053] The adhesive article (e.g., protective film) prepared as described above is suitable for use in flexible OLED device fabrication processes as a protective film with low adhesion, high adhesion stability, and/or low migration.

[0054] For example, a method for fabricating a flexible OLED device may include forming an OLED module on a surface of a substrate, e.g., a fragile layer such as a thin film encapsulation layer or a passivation layer on a surface of the OLED module opposite the substrate, and applying a protective film prepared as described herein to a surface of the fragile layer opposite the OLED module.

EXAMPLES

[0055] These examples are intended to illustrate some embodiments of the invention and should not be interpreted as limiting the scope of the invention set forth in the claims. Starting materials used in these examples are described in Table 1.

Table 1 - Starting Materials Used in the Examples

Example 1 - Preparation of Pressure Sensitive Adhesive Composition Samples

[0056] The general procedure for preparing samples of pressure sensitive adhesive compositions was as follows: For preparing the sample labelled Ex. 1, a solution was prepared by mixing the following starting materials in a mixer: Firstly, 100 g of the starting material (Al) was dissolved in 330 g of toluene (H). Then, 83.3 g of starting material (Cl), 4.17 g of starting material (DI), 0.07 g of starting material (Fl), and starting material (Gl) were added. After mixing of above starting materials, the obtained solution was further mixed with 6.25 g of starting material (El). Mixing of the above starting materials with the aforementioned solution produced a silicone pressure sensitive adhesive composition. This composition was used for manufacturing an adhesive tape. Comparative Examples 1 - 23, and Examples 2 - 9 were prepared in the same manner using the starting materials and amounts in the tables.

Example 2 - Analysis of Pressure Sensitive Adhesives

[0057] In this Example 2A, Measurement of Adhesion Force was performed as follows: The silicone pressure sensitive adhesive composition prepared as described above was applied onto a polyethylene terephthalate (PET, 75 pm) film which, after curing to form a silicone pressure sensitive adhesive layer, had a thickness of 75 pm. A silicone pressure sensitive adhesive tape was produced by heating the film for 2 min at 150°C. The obtained pressure sensitive adhesive tape was pasted onto a peelable polyethylene terephthalate film by means of a laminator, and the resulting laminate was aged for 1 day at RT. The resulting sheet was cut into tape strips 2.54 cm (1 inch) wide, which were placed on a glass plate after the peelable polyethylene terephthalate film was removed, and bonded thereto by moving a rubber-lined pressure roller of 2 kg weight on the strip twice back and forth. The assembly was held at room temperature for 1 h. The adhesion force (gf/inch) was measured by peeling the tape off from the glass plate by pulling at a speed of 2400 mm/min and an angle of 180°. To investigate adhesion build-up during storage, an assembly that was prepared in the above same manner was stored at room temperature for 3 days, and then the adhesion force was measured in the same manner.

[0058] In this Example 2B, Residual Adhesive- Remaining Property and Silicone-Transfer Property - Residual Adhesion Rate (%) was evaluated as follows: The pressure sensitive adhesive tape (prepared according to above Example 2A) was cut into tape strips 2.54 cm (1 inch) wide, which were placed on a glass plate after the peelable polyethylene terephthalate film was removed, and bonded thereto by moving a rubber- lined pressure roller of 2 kg weight on the strip twice back and forth. After the samples were aged for 3 days at 50 °C, the resulting tapes were removed from the glass plate. And, TESA™ 7475 tape was adhered on the place that tape removed by 2 kg roller. After 30 minutes, the adhesion force was measured by pulling the TESA™ 7475 off from the adherend at an angle of 180° relative to the surface of the adherend with the use of a tensile tester at a constant speed of 300 mm/min. For a reference, TESA™ 7475 tape was adhered on a glass, and the adhesion force was measured by the same method. The degree of migration, called as Residual Adhesion Rate (%), was calculated from the formula; Residual Adhesion Rate (%) = [adhesion force of test sample, gf/inch] I [adhesion force of the reference sample, gf/inch].

[0059] In this Example 2C, Anti-scratch Property was measured as follows: On the pressure sensitive adhesive tape prepared by the above same method of Example 2A, surface scratch occurrence and scratch restoration were observed on the surface layer of the film using a copper brush. In Tables 2-7, PASS means that the sample was not scratched. NG means that it was scratched.

[0060] In this Example 2D, Restoration Property was measured as follows: On the pressure sensitive adhesive tape prepared by the above same method of Example 2A, indentation marks were observed after writing with a strong force on the surface layer of the film using a stylus pen. PASS means that no indentation mark was observed as the sample was instantly restored within 10 seconds. NG means that indentation mark was observed as it was not restored. Table 2 - Comparative Examples 1-5 and Example 1

Table 3 - Comparative Examples 6-11

Table 4 - Comparative Examples 12-14 and Examples 2-4

Table 5 - Comparative Examples 15-17 and Examples 5-7

Table 6 - Comparative Examples 18-21 and Examples 8-9

Table 7 - Comparative Examples 22-23

Industrial Applicability

[0061] During fabrication of an OLED device, weak or brittle layers need to be protected from damage (e.g., scratches or other shocks) using a protective film. There is an industry need to provide protective films with low adhesion and high adhesion stability (where adhesion does not increase during the time needed for the fabrication process to an extent that would cause delamination or damage) when the protective film is removed after use.

[0062] It is also important that the surface of the layer remain clean such that additional films or layers can be laminated thereto after removal of the protective film. Therefore, there is an industry need to provide a protective film with low migration (such that no or minimal amounts of adhesive from the protective film remain on the surface of the layer in the flexible OLED device after the protective film is removed.

[0063] As a protective film is exposed to various process condition (pressure and temperature) during OLED device fabrication, the protective film may be deformed and/or scratched by mechanical stress. Therefore, it is also desirable for the protective film to have anti-scratch and restorability against such mechanical stress.

[0064] The pressure sensitive adhesive composition described herein cures to form a pressure sensitive adhesive suitable for use in protective films for OLED device fabrication processes. The pressure sensitive adhesive can exhibit 1) very low adhesion, 2) adhesion stability during aging, 3) low migration, 4) anti-scratch property, and 5) restorability, as evaluated above according to the test methods in Example 2. The examples above show that the pressure sensitive adhesive prepared by curing the pressure sensitive adhesive composition described above may have very low adhesion as shown by adhesion force < 3 gf/ inch on glass (as tested according to Example 2A); good adhesion stability as shown by adhesion build up < 6 gf/ inch on glass (as tested according to Example 2A), low migration as shown by Residual Adhesion > 50% as calculated in Example 2B, Anti-scratch property that will PASS when tested according to Example 2C, and Restoration Property that will PASS when tested according to Example 2D. Without wishing to be bound by theory, it is thought that these properties as tested on glass will provide comparable results on weak or brittle substrates used in OLED fabrication processes, such as fragile layers, and it is expected that this combination of properties will allow a pressure sensitive adhesive film to be used in a protective film on a fragile layer during fabrication of a flexible OLED device.

Test Methods

[0065] The alkenyl content of alkenyl containing siloxanes described herein, e.g., starting materials (A), (B), and (C), may be calculated by calculating the total molecular weight of the siloxane, calculating the molecular weights of each unit containing an alkenyl group, and dividing the combined molecular weights of each unit containing an alkenyl group by the total molecular weight. For example, in the unit formula: (R¹2R²SiOi/2)d(R¹3SiOi/2)e(R¹R²SiO2/2)f(R¹2SiO2/2)_g, when R¹ is methyl and R² is vinyl, subscript d = 2, subscript e = 0, subscript f = 11.3, and subscript g = 7084, then the siloxane is a dimethylvinylsiloxy-terminated poly(dimethylsiloxane/methylvinylsiloxane) copolymer (M^Vi ₂D^Vin 3D4829) with number average molecular weight (Mn) and alkenyl (vinyl) content calculated as follows:

• Number average molecular weight of the copolymer is 526,439 g/mol,

If Mw of M^V1 = 93.20 g/mol, Mw of D = 74.15 g/mol and Mw of D^V| = 86.17 g/mol

526,439 g/mol

• The vinyl content = 0.07 %

If Mw of M^V1 = 93.20 g/mol, Mw of D = 74.15 g/mol, Mw of D^V1 = 86.17 g/mol, and Vinyl of Mw = 27 are,

-> Mn of M^ViD₇o84D^v'¹n.3M^Vi= [(2*27)+(l 1.3*27)]/[(2*93.2 + 7084*74.15 + 11.3*86.17)] * 100 % = 0.07 %

[0066] The silicon-bonded hydrogen (SiH) content of the polyalkylhydrogensiloxanes described herein can be determined using quantitative infra-red analysis in accordance with ASTM E168.

[0067] The silicon-bonded hydrogen to alkenyl (e.g., vinyl) ratio (i.e., SiH/Vi ratio) is important when relying on a hydrosilylation reaction cure process. Generally, this is determined by calculating the total weight % of alkenyl groups in the composition, e.g. vinyl [Vi] and the total weight % of silicon bonded hydrogen [SiH] in the composition and given the molecular weight of hydrogen is 1 and of vinyl (CH2=CH-) is 27 the molar ratio of silicon bonded hydrogen to vinyl is 27*[SiH]/[Vi]. Starting materials (A), (B), (C), (D), and any other starting materials that contain SiH and/or vinyl content, described above, may be selected so as to provide an SiH/Vi ratio of 3.3 to 5.21, as described above.

Usage of Terms

[0068] All amounts, ratios, and percentages are by weight unless otherwise indicated by the context of the specification. The articles ‘a’, ‘an’, and ‘the’ each refer to one or more, unless otherwise indicated by the context of the specification. The disclosure of ranges includes the range itself and also anything subsumed therein, as well as endpoints. For example, disclosure of a range of 0.7 to 1.2 includes not only the range of 0.7 to 1.2, but also 0.7, 0.8, 0.85, 0.9, 1, 1.1, and 1.2 individually, as well as any other number subsumed in the range. Furthermore, disclosure of a range of, for example, 0.7 to 1.2 includes the subsets of, for example, 0.7 to 0.85, 0.9 to 1.05, and 1.05 to 1.2 as well as any other subset subsumed in the range. Similarly, the disclosure of Markush groups includes the entire group and also any individual members and subgroups subsumed therein. For example, disclosure of the Markush group a vinyl, allyl or hexenyl includes the member vinyl individually; the subgroup vinyl and hexenyl; and any other individual member and subgroup subsumed therein.

[0069] Abbreviations used herein have the meanings shown below in Table 8.

Table 8 - Abbreviations

Embodiments of the Invention

[0070] In a first embodiment, a method for fabricating a flexible organic light emitting diode device comprises:

1) applying a pressure sensitive adhesive composition to a surface of a substrate,

2) curing the pressure sensitive adhesive composition to form a pressure sensitive adhesive film, and

3) applying the pressure sensitive adhesive film to a fragile layer in the device; wherein the pressure sensitive adhesive composition comprises

(A) a first alkenyl containing polydialkylsiloxane gum, where the first alkenyl containing polydialkylsiloxane gum has silicon bonded alkyl groups with 1 to 10 carbon atoms and silicon bonded alkenyl groups with 2 to 6 carbon atoms, and where the vinyl functionalities are present in an amount of 0.03 weight % to 0.11 weight % based on the weight of the first alkenyl containing polydialkylsiloxane gum, optionally (B) a second alkenyl containing polydialkylsiloxane gum, where the second alkenyl containing poly dialkylsiloxane gum has silicon bonded alkyl groups with 1 to 10 carbon atoms and silicon bonded alkenyl groups with 2 to 6 carbon atoms, and where the vinyl functionalities are present in an amount of 0.3 weight % to 1.1 weight % based on the weight of the second alkenyl containing polydialkylsiloxane gum; where starting materials (A) and (B) are present in amounts sufficient to provide a weight ratio calculated by (B)/[(A) + (B)] of 0 to 0.5;

(D) a polyalkylhydrogensiloxane having silicon bonded alkyl groups with 1 to 10 carbon atoms and having at least three silicon bonded hydrogen per molecule, and having an average of at least 1 weight % silicon bonded hydrogen atoms,

(E) a platinum group metal catalyst in an amount sufficient to provide 10 to 5000 ppm concentration of Pt group metal by weight in the composition, and

(F) an acetylenic alcohol, and optionally (G) an anchorage additive;

10 weight % to 90 weight % based on combined weights of all starting materials in the composition of (H) an organic solvent; and with the proviso that all starting materials in the composition combined have a molar ratio of silicon bonded hydrogen atoms I silicon bonded alkenyl groups (SiH/Vi ratio) of 3.33 to 5.21.

[0071] In a second embodiment, a method for fabricating a flexible organic light emitting diode device comprises: applying a pressure sensitive adhesive film to a fragile layer or a thin film encapsulation layer in the device; wherein the pressure sensitive adhesive film comprises a cured product of a pressure sensitive adhesive composition comprising

(C) an alkenyl containing polydialkylsiloxane polymer, where the alkenyl containing polydialkylsiloxane polymer has silicon bonded alkyl groups with 1 to 10 carbon atoms and silicon bonded alkenyl groups with 2 to 6 carbon atoms, and where the vinyl functionalities are present in an amount of 0.01 weight % to 2 weight % based on the weight of the alkenyl containing polydialkylsiloxane polymer; where starting materials (A), (B), and (C) are present in amounts to provide a weight ratio calculated by [(A) + (B)]/(C) of 0.6 to 1.5;

(F) an acetylenic alcohol, and optionally (G) an anchorage additive;

[0072] In a third embodiment, in the method of the first embodiment or the second embodiment, (A) the first alkenyl containing poly dialkylsiloxane gum has unit formula (I): (R¹2R²SiOi/2)d(R¹3SiOi/2)e(R¹R²SiO2/2)f(R¹2SiO2/2)_g, where each R¹ is independently an alkyl group of 1 to 10 carbon atoms; each R² is independently an alkenyl group of 2 to 6 carbon atoms; subscripts d, e, f, and g represent average number of each unit in the unit formula and have values such that 2 > d > 0, 2 > e > 0, 20 > f > 5, 10,000 > g > 2,000, and a quantity (d + e) = 2.

[0073] In a fourth embodiment, in the method of the first embodiment or the second embodiment, (A) the first alkenyl containing polydialkylsiloxane gum has 0.05 weight % to 0.09 weight % vinyl functionalities.

[0074] In a fifth embodiment, in the method of the first embodiment or the second embodiment, (B) the second alkenyl containing polydialkylsiloxane gum is present, and the second alkenyl containing poly dialkylsiloxane gum has unit formula (II): (R¹2R²SiOi/2)h(R¹3SiOi/2)i(R¹R²SiO2/2)j(R¹2SiO2/2)k, where each R¹ is independently an alkyl group of 1 to 10 carbon atoms; each R² is independently an alkenyl group of 2 to 6 carbon atoms; subscripts h, i, j, and k represent average number of each unit in the unit formula and have values such that 2 > h > 0, 2 > i > 0, 100 > j > 21, 10,000 > k > 2,000, and a quantity (h + i) = 2. [0075] In a sixth embodiment, in the method of the first embodiment or the second embodiment, (B) the second alkenyl containing polydialkylsiloxane gum is present and has 0.5 weight % to 0.9 weight % vinyl functionalities.

[0076] In a seventh embodiment, in the method of the first embodiment or the second embodiment, the weight ratio calculated by (B)/[(A) + (B)] is 0 to 0.43.

[0077] In an eighth embodiment, in the method of the first embodiment or the second embodiment, the weight ratio calculated by [(A) + (B)]/(C) is > 0 to 0.43.

[0078] In a ninth embodiment, in the method of the first embodiment or the second embodiment, the (C) the alkenyl containing poly dialkylsiloxane polymer has unit formula (III): (R¹2R²SiOi/2)i(R¹3SiOi/2)m(R¹R²SiO2/2)n(R¹2SiO₂/2)o, where each R¹ is independently an alkyl group of 1 to 10 carbon atoms; each R² is independently an alkenyl group of 2 to 6 carbon atoms; subscripts 1, m, n, and o represent average number of each unit in the unit formula and have values such that 2 > 1 > 0, 2 > m > 0, 100 > n > 0, 1,000 > o > 10, and a quantity (1 + m) = 2.

[0079] In a tenth embodiment, in the method of the first embodiment or the second embodiment, the weight ratio calculated by [(A) + (B)]/(C) is 0.6 to 1.5.

[0080] In an eleventh embodiment, in the method of the first embodiment or the second embodiment, the weight ratio calculated by [(A) + (B)]/(C) is 0.6 to 1.3.

[0081] In a twelfth embodiment, in the method of the first embodiment or the second embodiment, the weight ratio calculated by [(A) + (B)]/(C) is 0.7 to 1.2.

[0082] In a thirteenth embodiment, in the method of the first embodiment or the second embodiment, the fragile layer is a passivation layer.

[0083] In a fourteenth embodiment, in the method of the first embodiment or the second embodiment, the fragile layer is a thin film encapsulation layer.

Claims

Claims:

1. A pressure sensitive adhesive composition comprising:

(A) a first alkenyl containing polydialkylsiloxane gum, where the first alkenyl containing polydialkylsiloxane gum has silicon bonded alkyl groups with 1 to 10 carbon atoms and silicon bonded alkenyl groups with 2 to 6 carbon atoms, and where vinyl functionalities are present in an amount of 0.03 weight % to 0.11 weight % based on the weight of the first alkenyl containing polydialkylsiloxane gum, optionally (B) a second alkenyl containing polydialkylsiloxane gum, where the second alkenyl containing poly dialkylsiloxane gum has silicon bonded alkyl groups with 1 to 10 carbon atoms and silicon bonded alkenyl groups with 2 to 6 carbon atoms, and where vinyl functionalities are present in an amount of 0.3 weight % to 1.1 weight % based on the weight of the second alkenyl containing polydialkylsiloxane gum; where starting materials (A) and (B) are present in amounts sufficient to provide a weight ratio calculated by (B)/[(A) + (B)] of 0 to 0.5;

(C) an alkenyl containing polydialkylsiloxane polymer, where the alkenyl containing polydialkylsiloxane polymer has silicon bonded alkyl groups with 1 to 10 carbon atoms and silicon bonded alkenyl groups with 2 to 6 carbon atoms, and where vinyl functionalities are present in an amount of 0.01 weight % to 2 weight % based on the weight of the alkenyl containing polydialkylsiloxane polymer; where starting materials (A), (B), and (C) are present in amounts to provide a weight ratio calculated by [(A) + (B)]/(C) of 0.5 to 2.5;

(F) an acetylenic alcohol, and optionally (G) an anchorage additive;

2. The composition of claim 1, where (A) the first alkenyl containing poly dialkylsiloxane gum has unit formula (I): (R¹2R²SiOi/2)d(R¹3SiOi/2)_e(R¹R²SiO2/2)f(R¹2SiO2/2)g, where each R¹ is independently an alkyl group of 1 to 10 carbon atoms; each R² is independently an alkenyl group of 2 to 6 carbon atoms; subscripts d, e, f, and g represent average number of each unit in the unit formula and have values such that 2 > d > 0, 2 > e > 0, 20 > f > 5, 10,000 > g > 2,000, and a quantity (d + e) = 2.

3. The composition of claim 1 or claim 2, where (B) the second alkenyl containing polydialkylsiloxane gum is present, and the second alkenyl containing polydialkylsiloxane gum has unit formula (II): (R¹2R²SiOi/2)h(R¹3SiOi/2)i(R¹R²SiO2/2)j(R¹2SiO2/2)k, where each R¹ is independently an alkyl group of 1 to 10 carbon atoms; each R² is independently an alkenyl group of 2 to 6 carbon atoms; subscripts h, i, j, and k represent average number of each unit in the unit formula and have values such that 2 > h > 0, 2 > i > 0, 100 > j > 21, 10,000 > k > 2,000, and a quantity (h + i) = 2.

4. The composition of any one of claims 1 to 3, where (A) the first alkenyl containing polydialkylsiloxane gum has 0.05 weight % to 0.09 weight % vinyl functionalities.

5. The composition of any one of claims 1 to 4 where (B) the second alkenyl containing polydialkylsiloxane gum is present and has 0.5 weight % to 0.9 weight % vinyl functionalities.

6. The composition of any one of claims 1 to 5, where (C) the alkenyl containing poly dialkylsiloxane polymer has unit formula (III): (R¹ ₂R²SiOi/2)i(R¹3SiOi/2)m(R¹R²SiO2/2)n(R¹2SiO2/2)o, where each R¹ is independently an alkyl group of 1 to 10 carbon atoms; each R² is independently an alkenyl group of 2 to 6 carbon atoms; subscripts 1, m, n, and o represent average number of each unit in the unit formula and have values such that 2 > 1 > 0, 2 > m > 0, 100 > n > 0, 1,000 > o > 10, and a quantity (1 + m) = 2.

7. The composition of any one of claims 1 to 6, where the weight ratio calculated by [(A) + (B)]/(C) is 0.6 to 1.3.

8. The composition of any one of claims 1 to 7, where (D) the polyalkylhydrogensiloxane has unit formula (IV): (R¹3SiOi/2)3(R¹2SiO2/2)_p(R¹HSiO2/2)q, where each R¹ is independently an alkyl group of 1 to 10 carbon atoms; subscripts p and q represent average number of each difunctional unit in the unit formula and have values such that 0 < p < 2,000 and 2 < q < 2000.

9. The composition of any one of claims 1 to 8, where (E) the catalyst comprises a complex of chloroplatinic acid and a divinylsiloxane.

10. The composition of any one of claims 1 to 9, where (F) the acetylenic alcohol comprises ethynyl cyclohexanol.

11. The composition of any one of claims 1 to 10, where the composition is a multiple part composition comprising a base part and a curing agent part, where the base part comprises starting materials (A) and (D); and the curing agent part comprises starting materials (A) and (E); and the composition further comprises starting material (F) in one or more of the base part or a separate third part.

12. A method comprising optionally 1) treating a surface of a substrate,

2) applying a pressure sensitive adhesive composition according to any one of claims 1 to 10 to the substrate, and

3) drying the pressure sensitive adhesive composition to remove all or a portion of the solvent, and

4) curing the pressure sensitive adhesive composition to form a pressure sensitive adhesive film.

13. A method for fabricating a flexible organic light emitting diode device, where the method comprises: applying the pressure sensitive adhesive prepared in the method of claim 12 to a passivation layer in the device.

14. A pressure sensitive adhesive film prepared by the method of claim 13.

15. Use of the pressure sensitive adhesive film of claim 14 for protection of a passivation layer in a flexible organic light emitting diode device.