CN118541457A - Pressure sensitive adhesive composition, method for its preparation and use in flexible organic light emitting diode applications - Google Patents

Abstract

A pressure-sensitive adhesive composition can be cured via hydrosilylation to form a pressure-sensitive adhesive. The pressure-sensitive adhesive composition can be coated on a substrate and cured to form a protective film. The protective film can be used in a flexible OLED device manufacturing process, for example, to protect a passivation layer and/or a thin film encapsulation layer.

Description

Pressure-sensitive adhesive composition, preparation method thereof, and use thereof in flexible organic light-emitting diode applications

CROSS-REFERENCE TO RELATED APPLICATIONS

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

Technical Field

The present invention relates to a pressure sensitive adhesive composition that can be used in a process for making flexible organic light emitting diode (OLED) displays. The pressure sensitive adhesive composition cures to form a pressure sensitive adhesive having low initial adhesion, high adhesion stability over time, low migration, scratch resistance and/or recoverability properties.

Background Art

In a typical process for manufacturing flexible OLED displays, the 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. The weak or brittle layer needs to be protected from damage (e.g., scratches or other impacts) during further processing.

In order to protect these layers during the manufacturing process, a protective film with low adhesion is desired to prevent fragile layers (e.g., passivation layers or thin film encapsulation layers) from being delaminated on the surface of the OLED module during release of the protective film after use. If adhesion control fails and adhesion increases over time (i.e., during the manufacturing process), the layer may be delaminated or damaged when the protective film is removed. Therefore, there is an industry need to provide a protective film with low adhesion and high adhesion stability (wherein adhesion does not increase to a degree that will cause delamination or damage during the time required for the manufacturing process).

It is also important that the surface of the layer remains clean so that additional films or layers can be laminated thereto after the protective film is removed. Therefore, there is a need in the industry to provide a protective film with low migration so that after the protective film is removed, no adhesive from the protective film or minimal adhesive from the protective film remains on the surface of the layer in the flexible OLED device.

Summary of the invention

The pressure-sensitive adhesive composition comprises an alkenyl-containing polydialkylsiloxane gum, an alkenyl-containing polydialkylsiloxane polymer, a polyalkyl hydrogensiloxane, a platinum group metal catalyst, an acetylene alcohol and an organic solvent.

Also disclosed are a method for preparing the pressure-sensitive adhesive composition, a method for forming a pressure-sensitive adhesive article using the pressure-sensitive adhesive composition, and a method for manufacturing a flexible organic light-emitting diode device using the pressure-sensitive adhesive article.

DETAILED DESCRIPTION

The pressure-sensitive adhesive composition described above comprises:

(A) a first alkenyl-containing polydialkylsiloxane gum, wherein the first alkenyl-containing polydialkylsiloxane gum has silicon-bonded alkyl groups having 1 to 10 carbon atoms and silicon-bonded alkenyl groups having 2 to 6 carbon atoms, and wherein vinyl functional groups (i.e., _CH2 =CH- in the silicon-bonded alkenyl groups) are present in an amount of 0.03 wt% to 0.11 wt% based on the weight of the first alkenyl-containing polydialkylsiloxane gum;

optionally (B) a second alkenyl-containing polydialkylsiloxane gum, wherein the second alkenyl-containing polydialkylsiloxane gum has silicon-bonded alkyl groups having from 1 to 10 carbon atoms and silicon-bonded alkenyl groups having from 2 to 6 carbon atoms, and wherein the vinyl functional groups are present in an amount of 0.3 wt % to 1.1 wt % based on the weight of the second alkenyl-containing polydialkylsiloxane gum;

wherein starting material (A) and starting material (B) are present in amounts sufficient to provide a weight ratio of 0 to 0.5 calculated by (B)/[(A)+(B)];

(C) an alkenyl-containing polydialkylsiloxane polymer, wherein the alkenyl-containing polydialkylsiloxane polymer has silicon-bonded alkyl groups having from 1 to 10 carbon atoms and silicon-bonded alkenyl groups having from 2 to 6 carbon atoms, and wherein the vinyl functional groups are present in an amount of 0.01 wt % to 2 wt % based on the weight of the alkenyl-containing polydialkylsiloxane polymer;

wherein starting material (A), starting material (B) and starting material (C) are present in amounts to provide a weight ratio of 0.5 to 2.5 calculated by [(A) + (B)]/(C);

(D) a polyalkylhydrogensiloxane having a silicon-bonded alkyl group having from 1 to 10 carbon atoms and at least three silicon-bonded hydrogen atoms per molecule and having an average of at least 1 weight percent silicon-bonded hydrogen atoms,

(E) a platinum group metal catalyst;

(F) acetylenic alcohol;

Optionally (G) an anchor additive; and

(H) an organic solvent;

Provided that all starting materials combined in the composition have a molar ratio of silicon-bonded hydrogen atoms (SiH) to silicon-bonded alkenyl groups (Vi) [SiH/Vi ratio] of 3.33 to 5.21.

(A) First (low) alkenyl-containing polydialkylsiloxane gum

The starting material (A) in the pressure-sensitive adhesive composition is a first alkenyl-containing polydialkylsiloxane gum. The first alkenyl-containing polydialkylsiloxane gum has a silicon-bonded alkyl group with 1 to 10 carbon atoms and a silicon-bonded alkenyl group with 2 to 6 carbon atoms. Based on the weight of the first alkenyl-containing polydialkylsiloxane gum, the vinyl (CH ₂ =CH-) functional group (for example, in the silicon-bonded alkenyl group) is present in an amount of 0.03 wt % to 0.11 wt %. Alternatively, (A) the first alkenyl-containing polydialkylsiloxane gum may have 0.05 wt % to 0.09 wt % of the vinyl functional group.

The starting material (A) first alkenyl-containing polydialkylsiloxane gum may have a unit formula (I): (R ¹ ₂ R ² SiO _1/2 ) _d (R ¹ ₃ SiO _1/2 ) _e (R ¹ R ² SiO _2/2 ) _f (R ¹ ₂ SiO _2/2 ) _g , wherein each R ¹ is independently an alkyl group of 1 to 10 carbon atoms; each R ² is independently an alkenyl group of 2 to 6 carbon atoms; subscripts d, e, f, and g represent the 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 the amount (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 from 6,000 to 8,000; alternatively 6,500 to 7,500.

In unit formula (I), each R ¹ is independently an alkyl group of 1 to 10 carbon atoms and each R ² 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., isopropyl and/or n-propyl), butyl (e.g., isobutyl, n-butyl, tert-butyl and/or sec-butyl), amyl (e.g., isopentyl, neopentyl and/or tert-amyl), hexyl, heptyl, octyl, nonyl and decyl and a branched saturated monovalent hydrocarbon group of 6 to 10 carbon atoms. Alternatively, each R ¹ can be selected from methyl, ethyl and isopropyl. Alternatively, each R ¹ can be methyl. Suitable alkenyl groups include branched or unbranched monovalent hydrocarbon groups with terminal double bonds (vinyl functional groups). Alkenyl groups are 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 straight chain groups of 6 carbon atoms. Alternatively, each R ² may have the formula CH ₂ =CH-(CH ₂ ) _s -, wherein the subscript s is 0 to 4 (i.e., vinyl when s=0, or vinyl terminated when s>0). Alternatively, each R ² may be vinyl, allyl, or hexenyl; alternatively, each R ² may be vinyl or hexenyl. Alternatively, each R ² may be vinyl.

The starting material (A) is exemplified by

i) a bisvinyldimethylsiloxy-terminated polydimethylsiloxane,

ii) bisvinyldimethylsiloxy-terminated poly(dimethylsiloxane/methylvinylsiloxane),

iii) bisvinyldimethylsiloxy-terminated polymethylvinylsiloxane,

iv) bistrimethylsiloxy-terminated poly(dimethylsiloxane/methylvinylsiloxane),

v) bistrimethylsiloxy-terminated polymethylvinylsiloxane,

vi) bis-hexenyldimethylsiloxy-terminated polydimethylsiloxane,

vii) bis-hexenyldimethylsiloxy-terminated poly(dimethylsiloxane/methylhexenylsiloxane),

viii) polymethylhexenylsiloxane terminated with bis-hexenyldimethylsiloxy groups,

ix) bistrimethylsiloxy-terminated poly(dimethylsiloxane/methylhexenylsiloxane),

x) bistrimethylsiloxy-terminated polymethylhexenylsiloxane,

xi) bis-hexenyldimethylsiloxy-terminated poly(dimethylsiloxane/methylvinylsiloxane),

xii) bisvinyldimethylsiloxy terminated poly(dimethylsiloxane/methylhexenylsiloxane),

xii) a combination of two or more of the following: i), ii), iii), iv), v), vi), vii), viiii), ix), x), xi), and xii).

Methods for preparing alkenyl-containing polydialkylsiloxanes suitable for use as starting material (A), such as hydrolysis and condensation of 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.

The amount of (A) the first alkenyl-containing polydialkylsiloxane gum depends on a variety of factors, such as the exact content of alkenyl groups in the starting material (A), whether the starting material (B) is present, and whether any other starting materials contain alkenyl groups (e.g., (C) alkenyl-containing polydialkylsiloxane polymer and/or platinum group metal catalyst). However, the amount of the starting material (A) can be at least 57 parts by weight, alternatively at least 60 parts by weight, alternatively at least 65 parts by weight, alternatively at least 70 parts by weight, and alternatively at least 71 parts by weight; while the amount of the starting material (A) can be at most 100 parts by weight, alternatively at most 90 parts by weight, alternatively at most 80 parts by weight, alternatively at most 75 parts by weight, and alternatively at most 71 parts by weight.

(B) Second (higher) alkenyl-containing polydialkylsiloxane gum

The starting material (B) in the pressure-sensitive adhesive composition is a second alkenyl-containing polydialkylsiloxane gum, and the difference between the second alkenyl-containing polydialkylsiloxane gum and the first alkenyl-containing polydiorganosiloxane gum is at least that it has a higher content of vinyl functional groups. The second alkenyl-containing polydialkylsiloxane gum has a silicon-bonded alkyl group with 1 to 10 carbon atoms and a silicon-bonded alkenyl group with 2 to 6 carbon atoms. Based on the weight of the second alkenyl-containing polydialkylsiloxane gum, the vinyl functional group exists in an amount of 0.3 wt % to 1.1 wt %. Alternatively, (B) the second alkenyl-containing polydialkylsiloxane gum can have a vinyl functional group of 0.5 wt % to 0.9 wt %.

The starting material (B) second alkenyl-containing polydialkylsiloxane gum may have a unit formula (II): (R ¹ ₂ R ² SiO _1/2 ) _h (R ¹ ₃ SiO _1/2 ) _i (R ¹ R ² SiO _2/2 ) _j (R ¹ ₂ SiO _2/2 ) _k , wherein each R ¹ is independently an alkyl group of 1 to 10 carbon atoms as described above; each R ² is independently an alkenyl group of 2 to 6 carbon atoms as described above; subscripts h, i, j and k represent the 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 the amount (h+i)=2. Alternatively, in formula (II), subscript j may be 50 to 150. Alternatively, subscript k may be 5,000 to 7,000.

The starting material (B) is exemplified by

i) a bisvinyldimethylsiloxy-terminated polydimethylsiloxane,

ii) bisvinyldimethylsiloxy-terminated poly(dimethylsiloxane/methylvinylsiloxane),

iii) bisvinyldimethylsiloxy-terminated polymethylvinylsiloxane,

iv) bistrimethylsiloxy-terminated poly(dimethylsiloxane/methylvinylsiloxane),

v) bistrimethylsiloxy-terminated polymethylvinylsiloxane,

vi) bis-hexenyldimethylsiloxy-terminated polydimethylsiloxane,

vii) bis-hexenyldimethylsiloxy-terminated poly(dimethylsiloxane/methylhexenylsiloxane),

viii) polymethylhexenylsiloxane terminated with bis-hexenyldimethylsiloxy groups,

ix) bistrimethylsiloxy-terminated poly(dimethylsiloxane/methylhexenylsiloxane),

x) bistrimethylsiloxy-terminated polymethylhexenylsiloxane,

xi) bis-hexenyldimethylsiloxy-terminated poly(dimethylsiloxane/methylvinylsiloxane),

xii) bisvinyldimethylsiloxy terminated poly(dimethylsiloxane/methylhexenylsiloxane),

xii) a combination of two or more of the following: i), ii), iii), iv), v), vi), vii), viiii), ix), x), xi), and xii).

Methods for preparing alkenyl-containing polydialkylsiloxanes suitable for use as starting material (B), such as hydrolysis and condensation of 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.

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

(C) Alkenyl-containing polydialkylsiloxane polymer

The starting material (C) in the pressure-sensitive adhesive composition is an alkenyl-containing polydialkylsiloxane polymer, which differs from the gum (A) and the gum (B) at least in that the average number of siloxane units per molecule is lower. The alkenyl-containing polydialkylsiloxane polymer has a silicon-bonded alkyl group with 1 to 10 carbon atoms and a silicon-bonded alkenyl group with 2 to 6 carbon atoms. The vinyl functional group is present in an amount of 0.01 wt % to 2 wt % based on the weight of the alkenyl-containing polydialkylsiloxane polymer.

The starting material (C) alkenyl-containing polydialkylsiloxane polymer may have a unit formula (III): (R ¹ ₂ R ² SiO _1/2 ) _r (R ¹ ₃ SiO _1/2 ) _m (R ¹ R ² SiO _2/2 ) _n (R ¹ ₂ SiO _2/2 ) _o , wherein each R ¹ is independently an alkyl group of 1 to 10 carbon atoms as described above; each R ² is independently an alkenyl group of 2 to 6 carbon atoms as described above; subscripts i, m, n, and o represent the 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 the amount (r + m) = 2. Alternatively, in the unit formula (III), the subscript r may be 2 and the subscript m may be 0. Alternatively, subscript o may be 400 to 1,000; alternatively 450 to 950. Alternatively, subscript n may be zero.

The starting material (C) is exemplified by

i) a bisvinyldimethylsiloxy-terminated polydimethylsiloxane,

ii) bisvinyldimethylsiloxy-terminated poly(dimethylsiloxane/methylvinylsiloxane),

iii) bisvinyldimethylsiloxy-terminated polymethylvinylsiloxane,

iv) bistrimethylsiloxy-terminated poly(dimethylsiloxane/methylvinylsiloxane),

v) bistrimethylsiloxy-terminated polymethylvinylsiloxane,

vi) bis-hexenyldimethylsiloxy-terminated polydimethylsiloxane,

vii) bis-hexenyldimethylsiloxy-terminated poly(dimethylsiloxane/methylhexenylsiloxane),

viii) polymethylhexenylsiloxane terminated with bis-hexenyldimethylsiloxy groups,

ix) bistrimethylsiloxy-terminated poly(dimethylsiloxane/methylhexenylsiloxane),

x) bistrimethylsiloxy-terminated polymethylhexenylsiloxane,

xi) bis-hexenyldimethylsiloxy-terminated poly(dimethylsiloxane/methylvinylsiloxane),

xii) bisvinyldimethylsiloxy terminated poly(dimethylsiloxane/methylhexenylsiloxane),

xii) a combination of two or more of the following: i), ii), iii), iv), v), vi), vii), viiii), ix), x), xi), and xii).

Methods for preparing alkenyl-containing polydialkylsiloxanes suitable for use as starting material (B), such as hydrolysis and condensation of 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.

The amount of (C) alkenyl-containing polydialkylsiloxane polymer depends on a variety of factors, such as the exact amount of alkenyl groups in the starting material (C), the amount and alkenyl content of the starting material (A) present, whether the starting material (B) is present, and whether any other starting materials contain alkenyl groups (e.g., platinum group metal catalysts). However, the amount of starting material (C) can be 0 (because starting material (C) is optional). Alternatively, when (C) is present, the amount of (C) can be >0 parts by weight, alternatively at least 75 parts by weight, alternatively at least 80 parts by weight, alternatively at least 81 parts by weight, alternatively at least 82 parts by weight, and alternatively at least 83 parts by weight; while the amount of starting material (C) can be up to 143 parts by weight, alternatively up to 140 parts by weight, alternatively up to 135 parts by weight, alternatively up to 130 parts by weight, and alternatively up to 125 parts by weight. The amounts of starting material (A), starting material (B) and starting material (C) may be such that the 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 the weight ratio calculated by [(A) + (B)] / (C) may be at most 2.5, alternatively at most 1.5 and alternatively at most 1.3.

(D) Polyalkyl hydrogen siloxane

The starting material (D) in the pressure-sensitive adhesive composition is a polyalkylhydrogensiloxane having a silicon-bonded alkyl group with 1 to 10 carbon atoms and at least three silicon-bonded hydrogen atoms per molecule and an average of at least 1 weight percent silicon-bonded hydrogen atoms.

The starting material (D) polyalkylhydrogensiloxane may have the unit formula (IV): (R ¹ ₃ SiO _1/2 ) ₃ (R ¹ ₂ SiO _2/2 ) _p (R ¹ HSiO _2/2 ) _q , wherein each R ¹ is independently an alkyl group of 1 to 10 carbon atoms as described above; the subscripts p and q represent the average number of difunctional units per unit formula, and have values such that 0≤p≤2,000 and 2≤q≤2000. Alternatively, the subscript p may be 0. Alternatively, the subscript q may be 15 to 50, alternatively 20 to 45, alternatively 25 to 40, and alternatively 30 to 35.

Examples of polyalkylhydrogensiloxanes used as the starting material (D) are:

a) bisdimethylhydrogensiloxy terminated poly(dimethylsiloxane/methylhydrogensiloxane),

b) bis(dimethylhydrogensiloxy)-terminated polymethylhydrogensiloxane,

c) bistrimethylsiloxy-terminated poly(dimethylsiloxane/methylhydrogensiloxane),

d) bistrimethylsiloxy-terminated polymethylhydrogensiloxane, and

e) A combination of two or more of the following: a), b), c) and d).

Methods for 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. Pat. No. 2,823,218 to Speier, U.S. Pat. No. 3,957,713 to Jeram et al., and U.S. Pat. No. 4,329,273 to Hardman et al.

The amount of (D) polyalkylhydrogensiloxane polymer depends on a variety of factors, such as the alkenyl content and amount of starting material (A), starting material (B), and starting material (C) present, and whether any other starting material contains an alkenyl group (e.g., a platinum group metal catalyst). However, the amount of starting material (D) can be sufficient to provide the silicone pressure sensitive adhesive composition with an overall SiH/Vi ratio, i.e., a starting material that provides a molar ratio of silicon-bonded hydrogen atoms (SiH)/silicon-bonded alkenyl groups (Vi) in the combined composition 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, the total 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 the total SiH/Vi ratio may be at most 5.21, alternatively at most 5.1, alternatively at most 5.0; alternatively at most 4.8; alternatively at most 4.5; and alternatively at most 4.3. Alternatively, the polyalkyl hydrogen siloxane may be present in the pressure sensitive adhesive composition in an amount of 4 to 10 parts by weight.

(E) Platinum group metal catalyst

The pressure-sensitive adhesive composition also includes 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 can be a compound of such metals, such as chloroplatinic acid, hexahydrate chloroplatinic acid, platinum dichloride and a complex of the compound and an alkenyl functional organopolysiloxane or a platinum compound microencapsulated in a matrix or a core/shell structure. Complexes of platinum and alkenyl functional organopolysiloxane include complexes of 1,3-divinyl-1,1,3,3-tetramethyldisiloxane and platinum. These complexes can be microencapsulated in a resin matrix. Exemplary hydrosilylation catalysts are described in the following patents: U.S. Pat. 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 EP 0 347 895 B. Microencapsulated hydrosilylation catalysts and methods of making them are known in the art, as exemplified in U.S. Pat. Nos. 4,766,176 and 5,017,654.

The catalyst is added to the pressure sensitive adhesive composition in an amount sufficient to catalyze the hydrosilylation reaction, typically sufficient to provide 10 ppm to 5,000 ppm of a platinum group metal by weight based on the combined weight of all starting materials (excluding solvent) in the pressure sensitive adhesive composition. Alternatively, when the platinum group metal catalyst comprises a compound or complex of platinum and an alkenyl functional organopolysiloxane, such as a complex of 1,3-divinyl-1,1,3,3-tetramethyldisiloxane and platinum, the amount may be 5 to 10 parts by weight, alternatively 6 to 7.5 parts by weight.

(F) acetylenic alcohol

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

The amount of acetylene alcohol added to the composition will depend on a variety of factors, including the desired pot life of the pressure sensitive adhesive composition, whether the composition is a one-part or multi-part composition, the specific acetylene alcohol used, and the choice and amount of polyalkylhydrogensiloxane. However, when present, the amount of starting material (F) can be from 0.01 parts by weight to 0.5 parts by weight.

(G) Fixing additives

The pressure-sensitive adhesive composition may optionally include a fixing additive. Without being bound by theory, it is believed that the fixing additive will facilitate the bonding of the pressure-sensitive adhesive prepared by curing the pressure-sensitive adhesive composition described herein to the substrate. However, the presence of the fixing additive will not adversely affect the desired peel force, thereby allowing the pressure-sensitive adhesive to be removed from an electronic device (such as a fragile layer in an OLED) without damaging the device or leaving significant residue.

Suitable anchor 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 the silane coupling agents. Alternatively, the anchor additive may be tetramethoxysilane, tetraethoxysilane, dimethyldimethoxysilane, methylphenyldimethoxysilane, methylphenyldiethoxysilane, phenyltrimethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, vinyltriethoxysilane, allyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, -(3,4-epoxycyclohexyl)ethyltrimethoxysilane or 3-methacryloxypropyltrimethoxysilane.

Alternatively, examples of anchor additives may be reaction products of alkenyl-functionalized alkoxysilanes (e.g., vinyl alkoxysilanes) and epoxy-functionalized alkoxysilanes; reaction products of alkenyl-functionalized acetoxysilanes (such as vinyl acetoxysilanes) and epoxy-functionalized alkoxysilanes; and combinations (e.g., physical blends and/or reaction products) of polyorganosiloxanes having at least one aliphatically unsaturated hydrocarbon group and at least one hydrolyzable group per molecule and epoxy-functionalized alkoxysilanes (e.g., a combination of hydroxy-terminated vinyl-functionalized polydimethylsiloxanes and glycidoxypropyltrimethoxysilane). Suitable anchor additives and methods for making them are disclosed, for example, in U.S. Pat. No. 9,562,149; U.S. Patent Application Publication Nos. 2003/0088042, 2004/0254274, 2005/0038188, paragraph [0091] of 2012/0328863, and U.S. Patent Publication No. 2017/0233612; and in EP 0 556 023.

The fixing additive is commercially available. For example, SYL-OFF ^TM 297, SYL-OFF ^TM 397 and SYL-OFF ^TM 9176 are available from Dow Silicones Corporation (Midland, Michigan, USA). Other exemplary fixing additives include (G-1) vinyl triacetoxysilane, (G-2) glycidyloxypropyl trimethoxysilane, (G-3) 2-(3,4-epoxycyclohexyl)ethyl trimethoxysilane, (G-4) (G-1), (G-2) and (G-3) two or more of the combination; and (G-5) (G-1), (G-2), (G-3) and/or (G-4) any one of the combination and hydroxyl groups, methoxy groups, or hydroxyl groups and methoxy groups The combination of both end-capped polydimethylsiloxane. Combinations (G-4) and (G-5) can be physical blends and/or reaction products.

The amount of the fixing additive depends on a variety of factors, including the type of substrate to which the composition will be applied and whether a primer or other surface treatment is used prior to applying the composition. However, the amount of the fixing additive may be from 0 to 5 parts by weight, alternatively from 1 to 5 parts by weight.

(H) Organic solvents

The pressure-sensitive adhesive composition also includes a solvent. The solvent may be an organic solvent. The organic solvent may be an alcohol such as methanol, ethanol, isopropanol, butanol or n-propanol; a ketone such as acetone, methyl ethyl 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 dichloromethane; chloroform; dimethyl sulfoxide; dimethylformamide, acetonitrile; tetrahydrofuran; white spirit; solvent oil; naphtha; N-methylpyrrolidone; 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.

The amount of solvent will depend on various factors, including the type of selected solvent and the amount and type of other starting materials selected for the pressure-sensitive adhesive composition. However, based on the combined weight of all starting materials in the pressure-sensitive adhesive composition, the amount of solvent can be in the range of 10% to 90%, alternatively 20% to 60%. The solvent can be added during the preparation of the pressure-sensitive adhesive composition, for example, to help mixing and delivery. All or part of the solvent can be added together with one of the other starting materials. For example, one or more of glue, polymer and catalyst can be dissolved in a solvent (such as aromatic hydrocarbons or alcohol) before combining with other starting materials in the composition. After the preparation of the pressure-sensitive adhesive composition, all or part of the solvent can be optionally removed.

When selecting starting materials for the above-mentioned pressure-sensitive adhesive composition, there may be overlap between the starting material types because some starting materials described herein may have more than one function. For example, some alkoxysilanes can be used as adhesion promoters and anchor additives. When additional starting materials are added to the composition, the additional starting materials are different from each other and different from the desired starting materials in the composition.

The pressure sensitive adhesive composition may be free of silicone resins, such as polyorganosilicate resins and/or silsesquioxane resins. As used herein, "free of silicone resins" means that the pressure sensitive adhesive composition contains an undetectable amount of silicone resin or an amount of silicone resin that does not change the properties measured according to Example 2 below compared to the same composition without the silicone resin.

The pressure-sensitive adhesive composition may contain no filler or only a limited amount of filler, such as 0% to 30% based on the combined weight of all starting materials in the composition. Without being bound by theory, it is believed that fillers may agglomerate or otherwise stick to the equipment used to apply or dispense the pressure-sensitive adhesive composition, and if optical transparency is desired, fillers may hinder the optical properties (e.g., transparency) of the pressure-sensitive adhesive composition and the silicone pressure-sensitive adhesive film formed therefrom. Fillers may also be detrimental to the adhesion of the silicone pressure-sensitive adhesive film to the substrate.

The pressure sensitive adhesive composition can be prepared by a process comprising mixing all the starting materials together by any convenient means, such as mixing at ambient temperature or elevated temperature. The acetylenic alcohol can be added prior to the platinum group metal catalyst, for example when the pressure sensitive adhesive composition is to be prepared at elevated temperature and/or when the pressure sensitive adhesive composition is to be prepared as a one-part composition.

Alternatively, the pressure-sensitive adhesive composition can be prepared as a multi-part composition, for example, when the composition will be stored for a long period of time before use. In the multi-part composition, the platinum group metal catalyst is stored in a portion separate from any starting material having silicon-bonded hydrogen atoms (e.g., polyalkyl hydrogen siloxane), and the portions are combined shortly before the pressure-sensitive adhesive composition is used. For example, a two-part composition can be prepared by combining starting materials including one or more of the following to form a base portion by any convenient means (such as mixing): a first alkenyl-containing polydialkylsiloxane gum, a second alkenyl-containing polydialkylsiloxane gum, and an alkenyl-containing polydialkylsiloxane polymer; polyalkyl hydrogen siloxane; and an organic solvent, and optionally one or more of the above-mentioned other additional starting materials. The curing agent can be prepared by combining the starting materials including one or more of the following in any convenient manner (such as mixing): a first alkenyl-containing polydialkylsiloxane gum, a second alkenyl-containing polydialkylsiloxane gum and an alkenyl-containing polydialkylsiloxane polymer; a platinum group metal catalyst; and an organic solvent, and optionally one or more other additional starting materials mentioned above. The starting materials can be combined at ambient temperature or elevated temperature. The acetylene alcohol can be included in one or more of the base material part, the curing agent part or an independent additional part. The fixing additive can be added to the base material part, or it can be added as a separate additional part. When a two-part composition is used, the weight ratio of the amount of the base material part to the amount of the curing agent part can be in the range of 1:1 to 10:1. The pressure-sensitive adhesive composition will be cured via a hydrosilylation reaction to form a pressure-sensitive adhesive.

The above method may also include one or more additional steps. The pressure-sensitive adhesive composition prepared as described above may be used to form an adhesive article on a substrate, for example, a pressure-sensitive adhesive (prepared by curing the above pressure-sensitive adhesive composition). Therefore, the above method may also include applying the pressure-sensitive adhesive composition to the substrate.

The pressure-sensitive adhesive curable composition can be applied to the substrate by any convenient means. For example, the pressure-sensitive adhesive curable composition can be applied to the substrate by a gravure coater, an offset coater, a photo-gravure coater, a roll coater, a reverse roll coater, an air knife coater, or a curtain coater.

The substrate can be any material that can withstand the curing conditions (described below) for curing the pressure-sensitive adhesive curable composition to form a 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 include plastic films, such as polyimide (PI), polyetheretherketone (PEEK), polyethylene naphthalate (PEN), liquid crystal polyarylate, polyamideimide (PAI), polyether sulfide (PES), or polyethylene terephthalate (PET), or PE (polyethylene), or PP (polypropylene). Alternatively, the substrate can be a metal foil, such as aluminum foil or copper foil. The thickness of the substrate is not important; however, the thickness can be in the range of 5 microns to 300 microns.

In order to improve the bonding of the pressure-sensitive adhesive to the substrate, the method may optionally further include treating the substrate before applying the pressure-sensitive adhesive composition. Treating the substrate may be carried out by any convenient means, such as applying a primer, or subjecting the substrate to corona discharge treatment, etching or plasma treatment before the pressure-sensitive adhesive composition is applied to the substrate.

Adhesive articles (such as protective films) can be prepared by applying the above-mentioned pressure-sensitive adhesive composition to the above-mentioned substrate. The method may also optionally include removing all or part of the solvent before and/or during curing. Removing the solvent can be carried out in any convenient manner, such as heating at a temperature that evaporates the solvent without fully curing the pressure-sensitive adhesive composition, for example, 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 part of the solvent (e.g., 30 seconds to 1 hour, alternatively 1 minute to 5 minutes).

Then, the method also includes curing the pressure-sensitive adhesive composition (when the drying step is carried out, it can remove some or all of the solvent) at 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 (for example, for 30 seconds to one hour, alternatively 1 minute to 5 minutes). This forms a pressure-sensitive adhesive film on the substrate. Drying and/or curing can be carried out 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 can be enough to make the thickness of the pressure-sensitive adhesive after curing can be 5 microns to 200 microns, and for protective films, the thickness can be 10 microns to 50 microns, alternatively 20 microns to 40 microns, and alternatively 30 microns.

The methods described herein may optionally further include applying a removable release liner to the surface of the pressure-sensitive adhesive film opposite the substrate, for example to protect the pressure-sensitive adhesive prior to use of the adhesive article.

The adhesive article (eg, protective film) prepared as described above is suitable for use in a flexible OLED device manufacturing process as a protective film having low adhesion, high adhesion stability, and/or low migration.

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

Example

These examples are intended to illustrate some embodiments of the invention and should not be construed as limiting the scope of the invention described in the claims.The 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

The general procedure for preparing the sample of pressure-sensitive adhesive composition is as follows: in order to prepare the sample marked as example 1, prepare solution by mixing the following starting material in a mixer: first, 100g starting material (A1) is dissolved in 330g toluene (H). Then, 83.3g starting material (C1), 4.17g starting material (D1), 0.07g starting material (F1) and starting material (G1) are added. After the above starting material is mixed, the solution obtained is further mixed with 6.25g starting material (E1). The above starting material is mixed with the above solution to produce silicone pressure-sensitive adhesive composition. This composition is used to make adhesive tape. Using the starting material and amount in the table, prepare comparative example 1 to comparative example 23 and example 2 to example 9 in the same manner.

Example 2 - Analysis of Pressure Sensitive Adhesives

In this example 2A, the measurement of adhesion is carried out as follows: the silicone pressure-sensitive adhesive composition prepared as described above is applied to a polyethylene terephthalate (PET, 75 μm) film, which has a thickness of 75 μm after curing to form a silicone pressure-sensitive adhesive layer. Silicone pressure-sensitive adhesive tape is produced by heating the film at 150 ° C for 2 minutes. The obtained pressure-sensitive adhesive tape is attached to a removable polyethylene terephthalate film by a laminator, and the resulting laminate is aged for 1 day at room temperature. The resulting sheet is cut into 2.54 cm (1 inch) wide tape strips, which are placed on a glass plate after removing the removable polyethylene terephthalate film, and bonded to it by moving a rubber-lined pressure roller with a weight of 2 kg back and forth twice on the strip. The assembly is kept at room temperature for 1 hour. Adhesion (gf/inch) is measured by pulling the tape off the glass plate at a speed of 2400 mm/min and an angle of 180 °. To investigate the adhesion build-up during storage, the assemblies prepared in the same manner as above were stored at room temperature for 3 days, and then the adhesion was measured in the same manner.

In this example 2B, residual adhesive-retention characteristics and silicone-transfer characteristics-residual adhesion rate (%) are assessed as follows: pressure-sensitive adhesive tape (prepared according to above-mentioned example 2A) is cut into 2.54cm (1 inch) wide tape strips, after removing removable polyethylene terephthalate film, these tape strips are placed on the glass plate, and bonded thereto by moving the pressure roller with rubber pad of twice 2kg weight back and forth on the strip. After sample was aged 3 days at 50 ℃, the gained tape was removed from the glass plate. And, TESA ^TM 7475 tapes are adhered to the position of removing this tape with 2kg rollers. After 30 minutes, TESA ^TM 7475 was pulled down from adherend with respect to the angle of 180 ° of adherend surface by using tensile tester at a constant speed of 300 mm/min to measure adhesion. As a reference, TESA ^TM 7475 tapes are adhered on the glass, and adhesion is measured by the same method. The degree of migration, called residual adhesion (%), was calculated as follows: Residual adhesion (%) = [adhesion of test sample, gf/inch]/[adhesion of reference sample, gf/inch].

In this Example 2C, the scratch resistance property was measured as follows: On the pressure-sensitive adhesive tape prepared by the same method as in Example 2A, surface scratch occurrence and scratch recovery were observed on the surface layer of the film using a copper brush. In Tables 2 to 7, "PASS" means that the sample was not scratched. NG means that the sample was scratched.

In this Example 2D, the recovery property is measured as follows: On a pressure-sensitive adhesive tape prepared by the same method as in the above Example 2A, an indentation mark is observed after writing with force on the surface layer of the film using a stylus pen. Pass means that no indentation mark is observed because the sample recovers immediately within 10 seconds. NG means that an indentation mark is observed because the sample does not recover.

Table 2 - Comparative Examples 1 to 5 and Example 1

Table 3 - Comparative Examples 6 to 11

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

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

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

Table 7 - Comparative Examples 22 to 23

Industrial Applicability

During the manufacture of OLED devices, protective films are used to protect weak or fragile layers from damage (e.g., scratches or other impacts). There is a need in the industry to provide protective films that have low adhesion and high adhesion stability (wherein the adhesion does not increase to a degree that would cause delamination or damage during the time required for the manufacturing process) when the protective film is removed after use.

It is also important that the surface of the layer remains clean so that additional films or layers can be laminated thereto after the protective film is removed. Therefore, there is a need in the industry to provide a protective film with low migration so that after the protective film is removed, no adhesive from the protective film or minimal adhesive from the protective film remains on the surface of the layer in the flexible OLED device.

When the protective film is exposed to various process conditions (pressure and temperature) during the manufacture of OLED devices, the protective film may be deformed and/or scratched due to mechanical stress. Therefore, it is also desirable that the protective film has scratch resistance and recoverability to such mechanical stress.

The pressure-sensitive adhesive composition described herein is cured to form a pressure-sensitive adhesive suitable for a protective film for an OLED device manufacturing process. The pressure-sensitive adhesive can exhibit 1) very low adhesion, 2) adhesion stability during aging, 3) low migration, 4) anti-scratch properties, and 5) recoverability, as evaluated according to the test method in Example 2. The above examples show that the pressure-sensitive adhesive prepared by curing the above-mentioned pressure-sensitive adhesive composition can 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 accumulation ≤6 gf/inch on glass (as tested according to Example 2A); low migration, as shown by residual adhesion>50% calculated as in Example 2B; anti-scratch properties that will pass when tested according to Example 2C; and recovery properties that will pass when tested according to Example 2D. Without being bound by theory, it is believed that these properties tested on glass will provide comparable results on weak or brittle substrates (such as fragile layers) used in OLED manufacturing processes, and it is expected that this combination of properties will allow the use of pressure sensitive adhesive films in protective films on fragile layers during the manufacture of flexible OLED devices.

Test Method

The alkenyl content of the alkenyl-containing siloxanes described herein, such as starting material (A), starting material (B), and starting material (C), can be calculated by calculating the total molecular weight of the siloxane, calculating the molecular weight of each unit containing an alkenyl group, and dividing the combined molecular weight of each unit containing an alkenyl group by the total molecular weight. For example, in the unit formula: ( ^{R12R2SiO1 /2} _{) d} ( _R13SiO1 ^/ 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, the siloxane is a dimethylvinylsiloxy-terminated poly(dimethylsiloxane/methylvinylsiloxane) copolymer ( ^{MVi2DVi11.3D4829} ) having a number average molecular weight (Mn) and alkenyl ⁽ _vinyl ) content calculated as _follows :

The number average molecular weight of the copolymer is 526,439 g/mol,

If Mw of M ^Vi = 93.20 g/mol, Mw of D = 74.15 g/mol and Mw of D ^Vi = 86.17 g/mol

→M ^Vi D ₇₀₈₄ D ^Vi _11.3 M ^Vi ’s Mn＝2*93.2+7084*74.15+11.3*86.17＝526,439g/mol

Vinyl content = 0.07%

If M ^Vi has Mw = 93.20 g/mol, D has Mw = 74.15 g/mol, D ^Vi has Mw = 86.17 g/mol and the vinyl group with Mw = 27 is

→M ^Vi D ₇₀₈₄ D ^Vi _11.3 M ^Vi ’s Mn=[(2*27)+(11.3*27)]/[(2*93.2+7084*74.15+11.3*86.17)]*100%=0.07%

The silicon-bonded hydrogen (SiH) content of the polyalkylhydrogensiloxanes described herein can be determined using quantitative infrared analysis according to ASTM E168.

When relying on a hydrosilylation reaction cure process, the ratio of silicon-bonded hydrogen to alkenyl (e.g., vinyl) groups (i.e., the SiH/Vi ratio) is important. Typically, this can be determined by calculating the total weight % of alkenyl groups in the composition, e.g., the total weight % of vinyl groups [Vi] and silicon-bonded hydrogen [SiH] in the composition, and assuming that the molecular weight of hydrogen is 1 and the molecular weight of vinyl ( _CH2 =CH-) is 27, then the molar ratio of silicon-bonded hydrogen to vinyl is 27*[SiH]/[Vi]. As described above, starting material (A), starting material (B), starting material (C), starting material (D), and any other starting materials described above containing SiH and/or vinyl content can be selected to provide a SiH/Vi ratio of 3.3 to 5.21.

Use of terminology

Unless otherwise specified in the context of this specification, all amounts, ratios and percentages are by weight. Unless otherwise specified in the context of this specification, the articles "a", "a kind of" and "the" each refer to one (a kind) or more (multiple). The disclosure of a range includes the range itself and any values and endpoints contained therein. For example, the disclosure of a range of 0.7 to 1.2 includes not only a range of 0.7 to 1.2, but also individually includes 0.7, 0.8, 0.85, 0.9, 1, 1.1 and 1.2, and any other numerical values contained in the range. In addition, for example, the disclosure of a range of 0.7 to 1.2 includes, for example, a subset of 0.7 to 0.85, 0.9 to 1.05 and 1.05 to 1.2, and any other subset contained in the range. Similarly, the disclosure of a Markush group includes the entire group and also includes any individual member and subgroup contained therein. For example, disclosure of the Markush group: vinyl, allyl, or hexenyl includes the individual member vinyl; the subgroups vinyl and hexenyl; and any other individual members and subgroups contained therein.

The abbreviations used herein have the meanings shown in Table 8 below.

Table 8 - Abbreviations

abbreviation definition ℃，deg C Celsius D Bifunctional siloxane unit of formula (Me ₂ SiO _2/2 ) D ^H Bifunctional siloxane unit of formula (MeHSiO _2/2 ) D ^Hex Bifunctional siloxane unit of formula (MeHexSiO _2/2 ) DP Degree of Polymerization D ^V Bifunctional siloxane unit of formula (MeViSiO _2/2 ) ETCH Ethynyl cyclohexanol GCMS Gas chromatography-mass spectrometry gf Gram GPC Gel Permeation Chromatography Hex Hexenyl hr Hour KG, kg kilogram kgf Kgf Me methyl min minute mPa·s Millipascal seconds ^M Monofunctional siloxane unit of formula (Me ₂ ViSiO _1/2 ) OLED Organic Light Emitting Diodes um Micrometer Vi Vinyl

Embodiments of the present invention

In a first embodiment, a method for manufacturing a flexible organic light emitting diode device includes:

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 the fragile layer in the device;

The pressure-sensitive adhesive composition comprises

(A) a first alkenyl-containing polydialkylsiloxane gum, wherein the first alkenyl-containing polydialkylsiloxane gum has silicon-bonded alkyl groups having from 1 to 10 carbon atoms and silicon-bonded alkenyl groups having from 2 to 6 carbon atoms, and wherein the vinyl functional groups are present in an amount of 0.03 wt % to 0.11 wt % based on the weight of the first alkenyl-containing polydialkylsiloxane gum,

optionally (B) a second alkenyl-containing polydialkylsiloxane gum, wherein the second alkenyl-containing polydialkylsiloxane gum has silicon-bonded alkyl groups having from 1 to 10 carbon atoms and silicon-bonded alkenyl groups having from 2 to 6 carbon atoms, and wherein the vinyl functional groups are present in an amount of 0.3 wt % to 1.1 wt % based on the weight of the second alkenyl-containing polydialkylsiloxane gum;

wherein starting material (A) and starting material (B) are present in amounts sufficient to provide a weight ratio of 0 to 0.5 calculated by (B)/[(A)+(B)];

(C) an alkenyl-containing polydialkylsiloxane polymer, wherein the alkenyl-containing polydialkylsiloxane polymer has silicon-bonded alkyl groups having from 1 to 10 carbon atoms and silicon-bonded alkenyl groups having from 2 to 6 carbon atoms, and wherein the vinyl functional groups are present in an amount of 0.01 wt % to 2 wt % based on the weight of the alkenyl-containing polydialkylsiloxane polymer;

wherein starting material (A), starting material (B) and starting material (C) are present in amounts to provide a weight ratio of 0.5 to 2.5 calculated by [(A) + (B)]/(C);

(D) a polyalkylhydrogensiloxane having a silicon-bonded alkyl group having from 1 to 10 carbon atoms and at least three silicon-bonded hydrogens per molecule and having an average of at least 1 weight percent silicon-bonded hydrogen atoms,

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

(F) an acetylenic alcohol, and

Optionally (G) an anchor additive;

10 wt % to 90 wt % of (H) an organic solvent, based on the combined weight of all starting materials in the composition; and

The proviso is that all starting materials combined in the composition have a molar ratio of silicon-bonded hydrogen atoms to silicon-bonded alkenyl groups (SiH/Vi ratio) of 3.33 to 5.21.

In a second embodiment, a method for manufacturing 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

(A) a first alkenyl-containing polydialkylsiloxane gum, wherein the first alkenyl-containing polydialkylsiloxane gum has silicon-bonded alkyl groups having from 1 to 10 carbon atoms and silicon-bonded alkenyl groups having from 2 to 6 carbon atoms, and wherein the vinyl functional groups are present in an amount of 0.03 wt % to 0.11 wt % based on the weight of the first alkenyl-containing polydialkylsiloxane gum,

optionally (B) a second alkenyl-containing polydialkylsiloxane gum, wherein the second alkenyl-containing polydialkylsiloxane gum has silicon-bonded alkyl groups having from 1 to 10 carbon atoms and silicon-bonded alkenyl groups having from 2 to 6 carbon atoms, and wherein the vinyl functional groups are present in an amount of 0.3 wt % to 1.1 wt % based on the weight of the second alkenyl-containing polydialkylsiloxane gum;

wherein starting material (A) and starting material (B) are present in amounts sufficient to provide a weight ratio of 0 to 0.5 calculated by (B)/[(A)+(B)];

(C) an alkenyl-containing polydialkylsiloxane polymer, wherein the alkenyl-containing polydialkylsiloxane polymer has silicon-bonded alkyl groups having from 1 to 10 carbon atoms and silicon-bonded alkenyl groups having from 2 to 6 carbon atoms, and wherein the vinyl functional groups are present in an amount of 0.01 wt % to 2 wt % based on the weight of the alkenyl-containing polydialkylsiloxane polymer;

wherein starting material (A), starting material (B) and starting material (C) are present in amounts to provide a weight ratio of 0.6 to 1.5 calculated by [(A) + (B)]/(C);

(D) a polyalkylhydrogensiloxane having a silicon-bonded alkyl group having from 1 to 10 carbon atoms and at least three silicon-bonded hydrogens per molecule and having an average of at least 1 weight percent silicon-bonded hydrogen atoms,

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

(F) an acetylenic alcohol, and

Optionally (G) an anchor additive;

10 wt % to 90 wt % of (H) an organic solvent, based on the combined weight of all starting materials in the composition; and

The proviso is that all starting materials combined in the composition have a molar ratio of silicon-bonded hydrogen atoms to silicon-bonded alkenyl groups (SiH/Vi ratio) of 3.33 to 5.21.

In a third embodiment, in the method according to the first embodiment or the second embodiment, (A) the first alkenyl-containing polydialkylsiloxane gum has a unit formula (I): (R ¹ ₂ R ² SiO _1/2 ) _d (R ¹ ₃ SiO _1/2 ) _e (R ¹ R ² SiO _2/2 ) _f (R ¹ ₂ SiO _2/2 ) _g , wherein each R ¹ is independently an alkyl group of 1 to 10 carbon atoms; each R ² is independently an alkenyl group of 2 to 6 carbon atoms; the subscripts d, e, f and g represent the 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 the amount (d+e)=2.

In a fourth embodiment, in the method according to the first embodiment or the second embodiment, (A) the first alkenyl-containing polydialkylsiloxane gum has 0.05 wt % to 0.09 wt % of vinyl functional groups.

In a fifth embodiment, in the method according to the first embodiment or the second embodiment, (B) the second alkenyl-containing polydialkylsiloxane gum is present, and the second alkenyl-containing polydialkylsiloxane gum has a unit formula (II): (R ¹ ₂ R ² SiO _1/2 ) _h (R ¹ ₃ SiO _1/2 ) _i (R ¹ R ² SiO _2/2 ) _j (R ¹ ₂ SiO _2/2 ) _k , wherein each R ¹ is independently an alkyl group of 1 to 10 carbon atoms; each R ² is independently an alkenyl group of 2 to 6 carbon atoms; the subscripts h, i, j and k represent the 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 the amount (h+i)=2.

In a sixth embodiment, in the method according to the first embodiment or the second embodiment, (B) the second alkenyl-containing polydialkylsiloxane gum is present and has 0.5 wt % to 0.9 wt % of vinyl functional groups.

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

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

In a ninth embodiment, in a method according to the first embodiment or the second embodiment, (C) the alkenyl-containing polydialkylsiloxane polymer has a unit formula (III): (R ¹ ₂ R ² SiO _1/2 ) _l (R ¹ ₃ SiO _1/2 ) _m (R ¹ R ² SiO _2/2 ) _n (R ¹ ₂ SiO _2/2 ) _o , wherein each R ¹ is independently an alkyl group of 1 to 10 carbon atoms; each R ² is independently an alkenyl group of 2 to 6 carbon atoms; the subscripts l, m, n and o represent the average number of each unit in the unit formula and have values such that 2≥l≥0, 2≥m≥0, 100≥n≥0, 1,000≥o≥10, and the amount (l+m)=2.

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

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

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

In a thirteenth embodiment, in the method according to the first embodiment or the second embodiment, the fragile layer is a passivation layer.

In a fourteenth embodiment, in the method according to the first embodiment or the second embodiment, the fragile layer is a thin film encapsulation layer.

Claims (15)

1. A pressure-sensitive adhesive composition, comprising: (A) a first alkenyl-containing polydialkylsiloxane gum, wherein the first alkenyl-containing polydialkylsiloxane gum has silicon-bonded alkyl groups having from 1 to 10 carbon atoms and silicon-bonded alkenyl groups having from 2 to 6 carbon atoms, and wherein the vinyl functional groups are present in an amount of 0.03 wt % to 0.11 wt % based on the weight of the first alkenyl-containing polydialkylsiloxane gum, optionally (B) a second alkenyl-containing polydialkylsiloxane gum, wherein the second alkenyl-containing polydialkylsiloxane gum has silicon-bonded alkyl groups having from 1 to 10 carbon atoms and silicon-bonded alkenyl groups having from 2 to 6 carbon atoms, and wherein the vinyl functional groups are present in an amount of 0.3 wt % to 1.1 wt % based on the weight of the second alkenyl-containing polydialkylsiloxane gum; wherein starting material (A) and starting material (B) are present in amounts sufficient to provide a weight ratio of 0 to 0.5 calculated by (B)/[(A)+(B)]; (C) an alkenyl-containing polydialkylsiloxane polymer, wherein the alkenyl-containing polydialkylsiloxane polymer has silicon-bonded alkyl groups having from 1 to 10 carbon atoms and silicon-bonded alkenyl groups having from 2 to 6 carbon atoms, and wherein the vinyl functional groups are present in an amount of 0.01 wt % to 2 wt % based on the weight of the alkenyl-containing polydialkylsiloxane polymer; wherein starting material (A), starting material (B) and starting material (C) are present in amounts to provide a weight ratio of 0.5 to 2.5 calculated by [(A) + (B)]/(C); (D) a polyalkylhydrogensiloxane having a silicon-bonded alkyl group having from 1 to 10 carbon atoms and at least three silicon-bonded hydrogens per molecule and having an average of at least 1 weight percent silicon-bonded hydrogen atoms, (E) a platinum group metal catalyst in an amount sufficient to provide a concentration of 10 ppm to 5000 ppm by weight of a Pt group metal in the composition, and (F) an acetylenic alcohol, and Optionally (G) an anchor additive; 10 wt % to 90 wt % of (H) an organic solvent, based on the combined weight of all starting materials in the composition; and The proviso is that all starting materials combined in the composition have a molar ratio of silicon-bonded hydrogen atoms to silicon-bonded alkenyl groups (SiH/Vi ratio) of 3.33 to 5.21. 2. The composition according to claim 1, wherein (A) the first alkenyl-containing polydialkylsiloxane gum has a unit formula (I): (R ¹ ₂ R ² SiO _1/2 ) _d (R ¹ ₃ SiO _1/2 ) _e (R ¹ R ² SiO _2/2 ) _f (R ¹ ₂ SiO _2/2 ) _g , wherein each R ¹ is independently an alkyl group of 1 to 10 carbon atoms; each R ² is independently an alkenyl group of 2 to 6 carbon atoms; the subscripts d, e, f and g represent the 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 the amount (d+e)=2. 3. The composition of claim 1 or claim 2, wherein (B) the second alkenyl-containing polydialkylsiloxane gum is present, and the second alkenyl-containing polydialkylsiloxane gum has a unit formula (II): (R ¹ ₂ R ² SiO _1/2 ) _h (R ¹ ₃ SiO _1/2 ) _i (R ¹ R ² SiO _2/2 ) _j (R ¹ ₂ SiO _2/2 ) _k , wherein each R ¹ is independently an alkyl group of 1 to 10 carbon atoms; each R ² is independently an alkenyl group of 2 to 6 carbon atoms; the subscripts h, i, j and k represent the 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 the quantity (h+i)=2. 4. The composition according to any one of claims 1 to 3, wherein (A) the first alkenyl-containing polydialkylsiloxane gum has 0.05 wt% to 0.09 wt% of vinyl functional groups. 5. The composition according to any one of claims 1 to 4, wherein (B) the second alkenyl-containing polydialkylsiloxane gum is present and has 0.5 wt% to 0.9 wt% of vinyl functional groups. 6. The composition according to any one of claims 1 to 5, wherein (C) the alkenyl-containing polydialkylsiloxane polymer has a unit formula (III): (R ¹ ₂ R ² SiO _1/2 ) _l (R ¹ ₃ SiO _1/2 ) _m (R ¹ R ² SiO _2/2 ) _n (R ¹ ₂ SiO _2/2 ) _o , wherein each R ¹ is independently an alkyl group of 1 to 10 carbon atoms; each R ² is independently an alkenyl group of 2 to 6 carbon atoms; the subscripts l, m, n and o represent the average number of each unit in the unit formula and have values such that 2≥l≥0, 2≥m≥0, 100≥n≥0, 1,000≥o≥10, and the amount (l+m)=2. 7. The composition according to any one of claims 1 to 6, wherein the weight ratio calculated by [(A)+(B)]/(C) is from 0.6 to 1.3. 8. The composition of any one of claims 1 to 7, wherein (D) the polyalkyl hydrogen siloxane has a unit formula (IV): (R ¹ ₃ SiO _1/2 ) ₃ (R ¹ ₂ SiO2/2) _p (R ¹ HSiO _2/2 ) _q , wherein each R ¹ is independently an alkyl group of 1 to 10 carbon atoms; the subscripts p and q represent the average number of difunctional units per unit formula and have values such that 0≤p≤2,000 and 2≤q≤2000. 9. The composition according to any one of claims 1 to 8, wherein (E) the catalyst comprises a complex of chloroplatinic acid and divinylsiloxane. 10. The composition according to any one of claims 1 to 9, wherein (F) the acetylene alcohol comprises ethynyl cyclohexanol. 11. The composition according to any one of claims 1 to 10, wherein the composition is a multi-part composition comprising a base part and a curing agent part, wherein the base part comprises a starting material (A) and a starting material (D); and the curing agent part comprises a starting material (A) and a starting material (E); and the composition further comprises a starting material (F) in one or more of the base part or a separate third part. 12. A method comprising Optionally 1) treating the surface of the substrate; 2) applying the 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 part of the solvent, and 4) curing the pressure-sensitive adhesive composition to form a pressure-sensitive adhesive film. 13. A method for manufacturing a flexible organic light emitting diode device, wherein the method comprises applying the pressure sensitive adhesive prepared in the method according to claim 12 to a passivation layer in the device. 14 . A pressure-sensitive adhesive film produced by the method according to claim 13 . 15. Use of the pressure-sensitive adhesive film according to claim 14 for protecting a passivation layer in a flexible organic light-emitting diode device.