CN116249734A

CN116249734A - Hydrosilylation reaction curable compositions forming silicone pressure sensitive adhesives adhered to optical silicone elastomers, methods of making and using the same in flexible display devices

Info

Publication number: CN116249734A
Application number: CN202180059882.7A
Authority: CN
Inventors: 曹青; 周彦; 许波驰
Original assignee: Dow Corning Corp
Current assignee: Dow Silicones Corp
Priority date: 2021-04-27
Filing date: 2021-04-27
Publication date: 2023-06-09
Also published as: KR20230020556A; KR102649396B1; WO2022226775A1; JP7359523B2; JP2023531148A

Abstract

The present invention provides a silicone pressure sensitive adhesive prepared by curing a hydrosilylation reaction curable composition. The composition comprises: (a) a polydiorganosiloxane gum component, (B) a polyorganosiloxane resin component, (C) a hydrosilylation reaction catalyst, (D) a polyorganosiloxane, (E) an alkyl borate, (F) a hydrosilylation reaction inhibitor, (G) a solvent, and (H) an anchoring additive. The silicone pressure sensitive adhesive adheres to optical silicone elastomers and is useful in preparing components of flexible display devices.

Description

Hydrosilylation reaction curable compositions forming silicone pressure sensitive adhesives adhered to optical silicone elastomers, methods of making and using the same in flexible display devices

Cross Reference to Related Applications

Without any means for

Technical Field

The present invention relates to a silicone pressure sensitive adhesive and methods of making and using the same. More particularly, the present invention relates to a hydrosilylation curable composition that cures to form a silicone pressure sensitive adhesive suitable for use in flexible display devices.

Background

Flexible display devices that can be deformed, for example, by bending, folding, winding, rolling, or stretching are being developed. The flexible display device may be deformed according to the needs of consumers or the situation in which the flexible display device is used. In general, various components of a display device are made of multiple layers, it is important that the layers adhere to each other and not suffer damage that leads to failure of the components when the flexible display device is deformed.

The optical silicone elastomer can be used to form a light transmissive (e.g., transparent or translucent) layer in a flexible display device. Optical silicone elastomers are known in the art and are commercially available. For example SILATIC ^TM MS-1001, MS-1002, MS-1003, MS-4001, MS-4002, and MS-4007 are moldable optical silicone elastomers, and SYLGARD ^TM 182. 184 and 186 are also optical silicone elastomers, all of which are commercially available from silicone company, midland, michigan, USA, dow Silicones Corporation.

However, optical silicone elastomers (such as those described above) may have the disadvantage of being difficult to adhere to other layers in flexible display devices. Accordingly, there is a need in the industry for a silicone pressure sensitive adhesive that can adhere to optical silicone elastomers and that does not cause failure of flexible display devices.

Disclosure of Invention

A hydrosilylation reaction curable composition is capable of forming a silicone pressure sensitive adhesive. A method for preparing the composition and a method for manufacturing an article using the composition are provided. The article may form part of a flexible display device.

Drawings

Fig. 1 shows a partial cross section of components of a flexible display device 100.

Reference numerals

100. Part of a flexible display device component

101. Substrate

101b surface of substrate 101

102. Silicone pressure sensitive adhesives

102a surface of a Silicone pressure sensitive adhesive 102

102b opposing surfaces of the silicone pressure sensitive adhesive 102

103. Optical silicone elastomer

103a surface of optical silicone elastomer 103

Detailed Description

A hydrosilylation reaction curable composition for forming a silicone pressure sensitive adhesive comprising:

(A) A polydiorganosiloxane gum component comprising

32.2 to 44.6% by weight of the unit formula (R) based on the combined weight of the starting materials (A) to (F) ^M ₂ R ^U SiO _1/2 ) ₂ (R ^M ₂ SiO _2/2 ) _a (A-1) aliphatically unsaturated polydiorganosiloxane gums, wherein each R ^M Is an independently selected monovalent hydrocarbon group of 1 to 30 carbon atoms free of aliphatic unsaturation; each R ^U A monovalent aliphatic unsaturated hydrocarbon group having 2 to 30 carbon atoms independently selected; and subscript a has a value sufficient to impart plasticity to the polydiorganosiloxane gum 50 to 200; and

0 wt% to<1.2% by weight of unit formula ((HO) R ^M ₂ SiO _1/2 ) ₂ (R ^M ₂ SiO _2/2 ) _a’ (A-2) hydroxyl-terminated polydiorganosiloxane gums, wherein each R ^M Is an independently selected monovalent hydrocarbon group of 1 to 30 carbon atoms free of aliphatic unsaturation; each subscript a' has a value sufficient to impart plasticity to the polydiorganosiloxane gum of from 20 mils (0.51 mm) to 80 mils (2.03 mm);

with the proviso that (A-1) the aliphatic unsaturated polydiorganosiloxane gum (A-2) the weight ratio of the hydroxyl terminated polydiorganosiloxane gum { (A-1): the (A-2) ratio } > 37.4:1;

(B) A polyorganosiloxane resin component comprising

44.8 to 58.9% by weight of the unit formula (R) based on the combined weight of the starting materials (A) to (F) ^M ₃ SiO _1/2 ) _z (SiO _4/2 ) _o Z _p Wherein Z is a hydrolyzable group, subscript p is 0 to a value sufficient to impart a hydrolyzable group content of up to 2% to said end-capped resin, and subscripts Z and o have values such that Z>4、o>1, and the amount (z+o) has a value sufficient to provide the end-capped resin with a number average molecular weight of 500g/mol to 2,700 g/mol; and

From 0 to 7% by weight, based on the combined weight of the starting materials (A) to (F), of the unit formula (R ^M ₃ SiO _1/2 ) _z’ (SiO _4/2 ) _o’ Z _p’ (B-2) an unblocked resin, wherein the subscript p' has a value sufficient to impart the unblocked resin>Values of 3% to 10% hydrolyzable group content, values of subscripts z ' and o ' are such that z '>4、o’>1, and the amount (z '+o') has a value sufficient to provide the unblocked resin with a number average molecular weight of 500g/mol to 5,000g/mol, wherein the blocked resin and the unblocked resin (B-1) are present in a combined amount of 44.8 to 65.8 weight percent based on the combined weight of the starting materials (a) to (F), provided that the unblocked resin (B-2) has a weight ratio { (B-2): (B-1) ratio } of 0.032:1 to 0.125:1;

wherein (A) the polydiorganosiloxane gum component and (B) the polyorganosiloxane resin component are present in a weight ratio (resin: gum ratio) of (B): A of less than or equal to 2.0:1;

0.01 to 5% by weight, based on the combined weight of the starting materials (a) to (F), of (C) a hydrosilylation catalyst;

(D) Unit type (R) ^M ₂ SiO _2/2 ) _e (HR ^M SiO _2/2 ) _f (R ^M ₂ HSiO _1/2 ) _g (R ^M ₃ SiO _1/2 ) _h Is a polyorganosiloxane; wherein subscript e is greater than or equal to 0, the followingThe index f is not less than 0, the quantity (e+f) is 4 to 500, the subscript g is 0, 1 or 2, the subscript h is 0, 1 or 2, the quantity (g+h) =2, and the quantity (f+g) is not less than 3; wherein (D) the polyorganosiloxane is present in an amount sufficient to provide a molar ratio { (D): ratio (A) of silicon-bonded hydrogen atoms to aliphatic unsaturated hydrocarbon groups of (A) the polydiorganosiloxane gum of from 20.8:1 to 57.7:1;

0.05 to 4.64% by weight, based on the combined weight of starting materials (a) to (F), of (E) a trialkyl borate;

0 to 5% by weight, based on the combined weight of the starting materials (a) to (F), of (F) a hydrosilylation reaction inhibitor; and

from >0 to 90 wt% of (G) solvent based on the combined weight of all starting materials in the composition; and

from 0 to 5% by weight, based on the combined weight of the starting materials (A) to (F), of (H) anchoring additives.

(A)Polydiorganosiloxane gum component

The hydrosilylation reaction curable composition comprises (a) a polydiorganosiloxane gum component. The polydiorganosiloxane gum component comprises: (A-1) an aliphatically unsaturated polydiorganosiloxane gum and (A-2) a hydroxy-terminated polydiorganosiloxane gum.

The starting material (A-1) aliphatically unsaturated polydiorganosiloxane gums have the unit formula (R ^M ₂ R ^U SiO _1/2 ) ₂ (R ^M ₂ SiO _2/2 ) _a Wherein each R is ^M Is an independently selected monovalent hydrocarbon group of 1 to 30 carbon atoms free of aliphatic unsaturation; each R ^U A monovalent aliphatic unsaturated hydrocarbon group having 2 to 30 carbon atoms independently selected; and subscript a has a value sufficient to impart to (A-1) the aliphatically unsaturated polydiorganosiloxane gum a plasticity of 20 mils (0.51 mm) to 80 mils (0.203 mm), alternatively 30 mils (0.76 mm) to 70 mils (1.78 mm), and alternatively 55 mils (1.40 mm) to 65 mils (1.65 mm), wherein plasticity is measured by applying a 1kg load at 25℃to a spherical sample weighing 4.2g for 3 minutes based on ASTM D926 and the results are measured in thousandths of an inch (mil), and The sequence is based on ASTM D926.

In the unit formula (A-1), each R ^M Is an independently selected monovalent hydrocarbon group of 1 to 30 carbon atoms free of aliphatic unsaturation. Alternatively, each R ^M May have 1 to 12 carbon atoms, alternatively 1 to 6 carbon atoms. R is R ^M Examples of suitable monovalent hydrocarbon groups of (a) are alkyl groups and aromatic groups, such as aryl groups and aralkyl groups. "alkyl" means a saturated monovalent hydrocarbon group that is cyclic, branched or unbranched. Examples of alkyl groups are, but are not limited to, methyl, ethyl, propyl (e.g., isopropyl and/or n-propyl), butyl (e.g., isobutyl, n-butyl, t-butyl, and/or sec-butyl), pentyl (e.g., isopentyl, neopentyl, and/or t-pentyl), hexyl, heptyl, octyl, nonyl, and decyl, and branched alkyl groups having 6 or more carbon atoms; and cycloalkyl groups such as cyclopentyl and cyclohexyl. "aryl" means a cyclic fully unsaturated hydrocarbon group. Examples of aryl groups are, but are not limited to, cyclopentadienyl, phenyl, anthracenyl and naphthyl. The monocyclic aryl group may have 5 to 9 carbon atoms, alternatively 6 to 7 carbon atoms, alternatively 5 to 6 carbon atoms. Polycyclic aryl groups may have from 10 to 17 carbon atoms, alternatively from 10 to 14 carbon atoms, and alternatively from 12 to 14 carbon atoms. "aralkyl" means an alkyl group having a pendant aryl group and/or a terminal aryl group or an aryl group having a pendant alkyl group. Exemplary aralkyl groups include tolyl, xylyl, benzyl, phenethyl, phenylpropyl, and phenylbutyl. Alternatively, each R ^M May be independently selected from the group consisting of alkyl and aryl. Alternatively, each R ^M Can be independently selected from methyl and phenyl. Alternatively, each R ^M May be an alkyl group. Alternatively, each R ^M May be methyl.

In the unit formula (A-1), each R ^U Are independently selected monovalent aliphatic unsaturated hydrocarbon groups having 2 to 30 carbon atoms. Alternatively, each R ^U May have 2 to 12 carbon atoms, alternatively 2 to 6 carbon atoms. Suitable monovalent aliphatic unsaturated hydrocarbon groups include alkenyl groups and alkynyl groups. "alkenyl" means havingBranched or unbranched monovalent hydrocarbon groups of one or more carbon-carbon double bonds. Examples of suitable alkenyl groups are vinyl, allyl, butenyl, pentenyl, hexenyl and heptenyl (including branched and straight chain isomers having 3 to 7 carbon atoms); cyclohexenyl. "alkynyl" means a branched or unbranched monovalent hydrocarbon group having one or more carbon-carbon triple bonds. Examples of suitable alkynyl groups are ethynyl, propynyl and butynyl (including branched and straight chain isomers having 2 to 4 carbon atoms). Alternatively, each R ^U May be alkenyl such as vinyl, allyl or hexenyl.

Polydiorganosiloxane gums are known in the art and can be prepared by methods such as hydrolysis and condensation of the corresponding organohalosilanes or equilibration of cyclic polydiorganosiloxanes. Examples of suitable polydiorganosiloxane gums for use in hydrosilylation reaction curable compositions are:

i) Dimethyl vinylsiloxy terminated polydimethyl siloxane,

ii) a dimethylvinylsiloxy terminated poly (dimethylsiloxane/methylphenyl) siloxane,

iii) Dimethyl vinylsiloxy terminated poly (dimethylsiloxane/diphenyl) siloxane,

iv) phenyl, methyl, vinyl-siloxy terminated polydimethylsiloxane,

v) a dimethylhexenyl siloxy terminated polydimethylsiloxane,

vi) a dimethylhexenyl-siloxy terminated poly (dimethylsiloxane/methylphenyl) siloxane,

vii) dimethylvinylsiloxy terminated poly (dimethylsiloxane/diphenyl) siloxane,

viii) combinations of two or more of i) to vii). Alternatively, the polydiorganosiloxane gum may be selected from the group consisting of: i) Dimethyl vinylsiloxy terminated polydimethyl siloxane,

v) a dimethylhexenyl siloxy terminated polydimethylsiloxane, and a combination of i) and v).

The starting material (a-1) aliphatically unsaturated polydiorganosiloxane gum is present in the hydrosilylation reaction curable composition in an amount of at least 32.2 wt.%, alternatively at least 34 wt.% and alternatively at least 34.2 wt.%, based on the combined weight of starting materials (a) through (F), while the amount can be up to 44.62 wt.%, alternatively up to 35 wt.% and alternatively up to 34.4 wt.%. Alternatively, the amount of (a-1) aliphatically unsaturated polydiorganosiloxane gum may be from 32.2 to 44.6, alternatively from 34 to 35, percent by weight based on the combined weight of starting materials (a) to (F).

In addition to the aliphatic unsaturated polydiorganosiloxane gum of (A-1), the starting material (A) polydiorganosiloxane component may optionally comprise units of formula (R ^M ₂ R ^U SiO _1/2 ) ₂ (R ^M ₂ SiO _2/2 ) _a’ (A-2) hydroxy-terminated polydiorganosiloxane gums, wherein R ^M And R is ^U As described above; and subscript a' has a value sufficient to impart to the (a-2) hydroxy-terminated polydiorganosiloxane gum a plasticity of 20 mils (0.51 mm) to 80 mils (2.03 mm), alternatively 30 mils (0.76 mm) to 70 mils (1.78 mm), and alternatively 45 mils (1.14 mm) to 65 mils (1.65 mm), wherein plasticity is measured by applying a 1kg load to a spherical sample having a weight of 4.2g at 25 ℃ for 3 minutes based on ASTM D926 and the results are measured in thousandths of an inch (mil), and the procedure is based on ASTM D926.

Hydroxyl-terminated polydiorganosiloxane gums suitable for use as starting material (a-2) are known in the art and can be prepared by methods such as hydrolysis and condensation of the corresponding organohalosilane or equilibration of cyclic polydiorganosiloxanes. Examples of suitable hydroxyl-terminated polydiorganosiloxane gums for use as starting material (a-2) in hydrosilylation reaction curable compositions are:

i) A bishydroxy-terminated polydimethylsiloxane,

ii) a bishydroxy-terminated poly (dimethylsiloxane/methylphenylsiloxane),

iii) A bishydroxy-terminated poly (dimethylsiloxane/diphenylsiloxane),

iv) phenyl, methyl, hydroxy-siloxy terminated polydimethylsiloxane,

v) a combination of two or more of i) to iv). Alternatively, the starting material (A-2) comprises a dihydroxy-terminated polydimethylsiloxane.

The starting material (a-2) hydroxyl-terminated polydiorganosiloxane gum is present in the hydrosilylation reaction curable composition in an amount of 0 wt% to <1.2 wt% based on the combined weight of starting materials (a) to (F). Alternatively, the (a-2) hydroxyl terminated polydiorganosiloxane gum can be present in an amount of at least 0.1 wt%, alternatively at least 0.13 wt%, while the amount can be up to 1.19%, alternatively up to 0.5%, on the same basis.

The starting materials (A-1) aliphatically unsaturated polydiorganosiloxane gums and (A-2) bishydroxy-terminated polydiorganosiloxanes can be present in amounts such that the weight ratio (A-1) to (A-2) can be greater than or equal to 37.4:1. Alternatively, the weight ratio (A-1): (A-2) may be at least 37.4:1, alternatively at least 50:1, alternatively at least 100:1, alternatively at least 150:1, alternatively at least 200:1, alternatively at least 250:1, and alternatively at least 270:1; meanwhile, when (A-2) a hydroxyl-terminated polydiorganosiloxane gum is present, the weight ratio (A-1): A-2 may be at most 350:1, alternatively at most 340:1, alternatively at most 325:1, alternatively at most 300:1, alternatively at most 275:1.

(B) Polyorganosilicate resin component

The hydrosilylation reaction curable composition further comprises a starting material (B) a polyorganosilicate resin component comprising (B-1) a blocked resin and (B-2) an unblocked resin. The polyorganosilicate resin comprises the formula R ^M ₃ SiO _1/2 Monofunctional units ("M" units) and of the formula SiO _4/2 Of (a "Q" unit), wherein R ^M As described above. Alternatively, at least one third, or at least two thirds, of R ^M The group is an alkyl group (e.g., a methyl group). Alternatively, an example of an M unit may be (Me ₃ SiO _1/2 ) And(Me ₂ PhSiO _1/2 ). The polyorganosiloxane resin is soluble in solvents such as those described below, exemplified by liquid hydrocarbons such as benzene, toluene, xylene, and heptane; or liquid organosilicon compounds such as low viscosity linear and cyclic polydiorganosiloxanes.

When prepared, the polyorganosiloxane resin comprises the M and Q units described above, and the polyorganosiloxane also comprises units having silicon-bonded hydroxyl groups and may comprise the formula Si (OsiR ^M ₃ ) ₄ Neoprene of (2), wherein R ^M As described above, the neoprene may be, for example, tetra (trimethylsiloxy) silane. ²⁹ Si NMR spectroscopy can be used to measure the hydroxyl content and molar ratio of M and Q units, where the ratio is expressed as { M (resin) }/{ Q (resin) }, excluding M and Q units from neoprene. The M: Q ratio represents the molar ratio of the total number of triorganosiloxy groups (M units) of the resin portion of the polyorganosiloxane resin to the total number of silicate groups (Q units) in the resin portion. The M to Q ratio may be 0.5:1 to 1.5:1.

Mn of the polyorganosiloxane resin depends on a variety of factors including the presence of the catalyst represented by R ^M The type of hydrocarbon group represented. When the peak representing the neoprene is excluded from the measurement results, mn of the polyorganosiloxane resin refers to the number average molecular weight measured using GPC. The Mn of the polyorganosiloxane resin is 500g/mol to 5,000g/mol, or 2,500g/mol to 5,000g/mol, or 2,700g/mol to 4,900g/mol, or 2,700g/mol to 4,700g/mol. GPC test methods suitable for measuring Mn are disclosed in reference example 1 at column 31 of U.S. Pat. No. 9,593,209.

U.S. patent 8,580,073, column 3, line 5 to column 4, line 31, and U.S. patent publication 2016/037682, paragraphs [0023] to [0026], hereby incorporated by reference, disclose MQ resins, which are suitable polyorganosiloxane resins for use in the hydrosilylation reaction curable compositions described herein. The polyorganosilicate resins can be prepared by any suitable method such as cohydrolysis of the corresponding silanes or by silica hydrosol capping methods. The polyorganosilicate resins may be prepared by silica hydrosol endcapping methods such as U.S. patent 2,676,182 to Daudt et al; U.S. Pat. No. 4,611,042 to river-Farrell et al; prepared by methods disclosed in U.S. patent 4,774,310 to Butler et al. The process of Daudt et al described above involves reacting a silica hydrosol under acidic conditions with a hydrolyzable triorganosilane such as trimethylchlorosilane, a siloxane such as hexamethyldisiloxane, or a mixture thereof, and recovering a copolymer having M units and Q units. The resulting copolymer typically contains from 2 to 5 weight percent hydroxyl groups.

Intermediates used in the preparation of the polyorganosilicate resins can be triorganosilanes and silanes having four hydrolyzable substituents or alkali metal silicates. The triorganosilane may have the formula R ^M ₃ SiX ¹ Wherein R is ^M As described above and X ¹ Represents a hydrolyzable substituent such as halogen, alkoxy, acyloxy, hydroxyl, oxime or ketoxime; alternatively, halogen, alkoxy or hydroxy. The silane having four hydrolyzable substituents may have the formula SiX ² ₄ Wherein each X ² Halogen, alkoxy or hydroxy. Suitable alkali metal silicates include sodium silicate.

The polyorganosiloxane resins prepared as described above are non-blocked resins which generally contain silicon-bonded hydroxyl groups, e.g., of the formula HOSi _3/2 And/or HOR ^M ₂ SiO _1/2 . The polyorganosilicate resin may comprise, as measured by NMR spectroscopy>3% to 10% of silicon-bonded hydroxyl groups. For some applications, it may be desirable to have an amount of silicon-bonded hydroxyl groups of 2% or less, alternatively 0.89% or less, alternatively<0.7%, alternatively less than 0.3%, alternatively less than 1% and alternatively 0.3% to 2%. The silicon-bonded hydroxyl groups formed during the preparation of the polyorganosiloxane resin can be converted to triorganosiloxane groups or to different hydrolyzable groups by reacting the silicone resin with a silane, disiloxane or disilazane containing the appropriate end groups in a process known as endcapping. The silane comprising hydrolyzable groups may be added in an excess molar amount of that required to react with silicon-bonded hydroxyl groups on the polyorganosiloxane resin.

When the polyorganosilicate resin is a blocked resin, the blocked resin may contain 2% or less, or 0.7% or less, or 0.3% to 0.8% of the formula HOSiO _3/2 And/or HOR ^M ₂ SiO _1/2 A unit of the representation, wherein R ^M As described above. The concentration of silanol groups present in the polyorganosiloxane can be determined using NMR spectroscopy as described above.

Thus, the polyorganosiloxane resin component comprises (B-1) the blocked resin as described above and (B-2) the unblocked resin as described above. The end-capping resin may have a unit type (R ^M ₃ SiO _1/2 ) _z (SiO _4/2 ) _o Z _p Wherein R is ^M As described above, and the values of subscripts z and o are such that o>1, and subscript z>4, the amount (o+z) has a value sufficient to impart the above Mn (e.g., 500g/mol to 5,000g/mol, or 1,000g/mol to 4,700g/mol, or 2,900g/mol to 4,100 g/mol) to the end-capping resin, and the subscript p has a value sufficient to impart the end-capping resin with the hydrolyzable group content (e.g., 0% to 2%, or 0% to 0.7%, or 0% to 0.3%) as described above. The starting material (B-2) non-blocked resin may have the unit formula (R) ^M ₃ SiO _1/2 ) _z’ (SiO _4/2 ) _o’ Z _p’ Wherein R is ^M As described above, and the subscripts z ' and o ' have values such that o '>1, and subscript z' >4, the amount (o ' +z ') has a value sufficient to impart the above Mn (e.g., 500g/mol to 5,000g/mol, or 1,000g/mol to 4,700g/mol, or 2,700g/mol to 4,300 g/mol) to the uncapped resin, and the subscript p ' has a value sufficient to impart the above hydrolyzable group content (e.g.,>3% to 10% a) value.

The hydrosilylation reaction curable composition comprises (B) a polyorganosilicate resin in an amount of 44.8 to 65.8 wt.%, alternatively 46.2 to 65.8 wt.%, and alternatively 61.5 to 62.6 wt.%, based on the combined weight of starting materials (a) to (F) (e.g., based on the combined weight of all starting materials in the hydrosilylation reaction curable composition, excluding solvent). The amount of blocked resin and unblocked resin in starting material (B) may be sufficient to provide an unblocked resin to blocked resin weight ratio (i.e., (B-2): (B-1) ratio) of 0.032:1 to 0.125:1, alternatively 0.118:1 to 0.124:1, and alternatively 0.123:1 to 0.124:1. Alternatively, the (B-2): (B-1) ratio may be at least 0.032, alternatively at least 0.11, and alternatively at least 0.118, while the (B-2): (B-1) ratio may be at most 0.125, alternatively at most 0.124, alternatively at most 0.12.

The starting material (A) polydiorganosiloxane gum component and starting material (B) the polyorganosiloxane resin component may be present in the hydrosilylation reaction curable composition in an amount sufficient to provide a weight ratio { i.e., (B): ratio } of (A) polydiorganosiloxane gum component of (B) polyorganosiloxane resin component of 2.0:1. Alternatively, the (B): a ratio may be at least 1.5:1, alternatively <1.8:1, while the (B): a ratio may be at most 2.0:1, alternatively at most 1.8:1. Alternatively, the ratio of (B): (A) may be 1.0:1 to 2.0:1, alternatively 1.8:1 to 1.9:1.

(C)Catalyst for hydrosilylation reaction

The starting material (C) in the hydrosilylation reaction curable composition is a hydrosilylation reaction catalyst. Hydrosilylation catalysts are known in the art and are commercially available. Hydrosilylation catalysts include platinum group metal catalysts. Such hydrosilylation reaction catalysts may be (C-1) metals selected from the following: platinum, rhodium, ruthenium, palladium, osmium, and iridium; alternatively platinum, ruthenium and iridium; and alternatively the metal may be platinum. Alternatively, the hydrosilylation catalyst may be a compound of (C-2) such a metal, for example tris (triphenylphosphine) rhodium (I) chloride (Wilkinson's catalyst)), rhodium biphosphine chelate such as [1, 2-bis (diphenylphosphine) ethane ]Rhodium dichloride or [1, 2-bis (diethylphosphine) ethane]Rhodium dichloride, chloroplatinic acid (Speier catalyst), chloroplatinic acid hexahydrate, or platinum dichloride. Alternatively, the hydrosilylation catalyst may be a complex of (C-3) a platinum group metal compound with an alkenyl-functional organopolysiloxane oligomer, or (C-4) a platinum group metal compound microencapsulated in a matrix or core-shell type structureAnd (3) an object. Complexes of platinum with alkenyl-functional organopolysiloxane oligomers include complexes of 1, 3-divinyl-1, 3-tetramethyldisiloxane with platinum (Karstedt catalyst). Alternatively, the hydrosilylation reaction catalyst may comprise a complex of (C-5) microencapsulated in a resin matrix. Exemplary hydrosilylation catalysts are described in U.S. patent 2,823,218 to Speier, U.S. patent 3,159,601 to Ashby, U.S. patent 3,220,972 to Lamoreaux, U.S. patent 3,296,291 to chank et al, U.S. patent 3,419,593 to Willing, U.S. patent 3,516,946 to Modic, U.S. patent 3,715,334 to Karstedt, U.S. patent 3,814,730 to Karstedt, U.S. patent 3,928,629 to Chandra, U.S. patent 3,989,668 to Lee et al, U.S. patent 4,766,176 to Lee et al, U.S. patent 4,784,879 to Togashi, U.S. patent 5,017,654 to Chung et al, U.S. patent 5,036,117 to Brow, U.S. patent 5,175,325 to Togashi et al, and EP 0 347 895A to Togashi et al. Hydrosilylation catalysts are commercially available, e.g. SYL-OFF ^TM 4000 catalyst and SYL-OFF ^TM 2700 is available from the dow silicone company (Dow Silicones Corporation).

The amount of hydrosilylation catalyst used herein will depend on a variety of factors including the choice of starting materials (D) polyorganosiloxane and (a) polydiorganosiloxane gum components, and the content of their respective silicon-bonded hydrogen atoms (SiH) and aliphatic unsaturated groups, and the content of platinum group metal in the catalyst selected, however, the amount of hydrosilylation catalyst is sufficient to catalyze the hydrosilylation reaction of SiH and aliphatic unsaturated groups, alternatively the amount of catalyst is sufficient to provide 1ppm to 6,000ppm of platinum group metal based on the combined weight of starting materials comprising silicon-bonded hydrogen atoms and aliphatic unsaturated hydrocarbon groups; alternatively, 1ppm to 1,000ppm, or 1ppm to 100ppm of the platinum group metal on the same basis. Alternatively, when the hydrosilylation reaction catalyst comprises a platinum-organosiloxane complex, the amount of hydrosilylation reaction catalyst can be from 0.01% to 5% based on the combined weight of starting materials (a) to (F) (e.g., the combined weight of all starting materials in the hydrosilylation reaction curable composition, excluding solvent).

(D) Polyorganosiloxane (I)

The starting material (D) in the hydrosilylation reaction curable composition is of the unit formula (R ^M ₂ SiO _2/2 ) _e (HR ^M SiO _2/2 ) _f ,(R ^M ₂ HSiO _1/2 ) _g (R ^M ₃ SiO _1/2 ) _h Is a polyorganosiloxane; wherein R is ^M As described above, subscript e.gtoreq.0, subscript f.gtoreq.0, amount (e+f) is from 4 to 500, subscript g is 0, 1 or 2, subscript h is 0, 1 or 2, amount (g+h) =2, and amount (f+g) is.gtoreq.3. Alternatively, the amount (f+g) may be sufficient to provide the polyorganosiloxane with a silicon-bonded hydrogen content of from 0.5% to 2%, alternatively from 0.6% to 1.5%, wherein the silicon-bonded hydrogen (Si-H) content of the polyorganosiloxane may be determined according to ASTM E168 using quantitative infrared analysis.

Examples of suitable polyorganohydrogen siloxanes are:

(D-1) bis-dimethylhydrosiloxy terminated poly (dimethyl/methylhydrogen) siloxane,

(D-2) bis-dimethylhydrosiloxy terminated polymethylhydrosiloxane,

(D-3) bis-trimethylsiloxy terminated poly (dimethyl/methylhydrogen) siloxane,

(D-4) bis-trimethylsiloxy terminated polymethylhydrosiloxane, and

(D-5) (D-1), (D-2), (D-3) and (D-4). Methods for preparing polyorganohydrosiloxanes, such as hydrolysis and condensation of organohydridosilanes, are well known in the art, see for example U.S. patent 3,957,713 to Jeram et al and U.S. patent 4,329,273 to Hardman et al. The polyorganohydrogen siloxanes can also be prepared as described, for example, in U.S. patent 2823218 to Speier et al, which discloses organohydrogen siloxane oligomers and linear polymers, such as 1, 3-pentamethyldisiloxane; bis-trimethylsiloxy terminated polymethylhydrosiloxane homopolymers; bis-trimethylsiloxy terminated poly (dimethyl/methylhydrogen) siloxane copolymers; cyclic polymethylhydrosiloxanes. The polyorganosiloxane is also commercially available, such as those available from Geles corporation (Gelest, inc., morrisville, pennsylvania, USA) of Morrisville, pa., such as HMS-H271, HMS-071, HMS-993, HMS-301R, HMS-031, HMS-991, HMS-992, HMS-993, HMS-082, HMS-151, HMS-013, HMS-053, HAM-301, HPM-502, and HMS-HMHM271.

The amount of polyorganosiloxane in the hydrosilylation reaction curable composition is from 0.1% to 5% based on the combined weight of starting materials (a) to (F). Alternatively, the amount of polyorganosiloxane in the hydrosilylation reaction curable composition can be at least 0.1%, alternatively at least 0.25%, alternatively at least 0.3%; meanwhile, the amount may be at most 5%, alternatively at most 2.5%, alternatively at most 1.5%, alternatively at most 1% on the same basis.

When relying on hydrosilylation curing processes, the ratio of silicon-bonded hydrogen to aliphatic unsaturation is important. Generally, this is determined by calculating the total weight percent of aliphatic unsaturation (e.g., vinyl) V in the composition and the total weight percent of silicon-bonded hydrogen H in the composition, and assuming a molecular weight of 1 for hydrogen and a molecular weight of 27 for vinyl, the molar ratio of silicon-bonded hydrogen to vinyl is 27H/V. The starting materials (A) polydiorganosiloxane gum component and (D) polyorganosiloxane may be present in the hydrosilylation reaction curable composition in amounts sufficient to provide a molar ratio { (D): (A) ratio } of silicon-bonded hydrogen atoms to aliphatic unsaturated hydrocarbon groups of at least 20.8:1, alternatively at least 28.7:1, while the ratio may be up to 57.7:1, alternatively up to 54.7:1. Alternatively, the (D): (A) ratio may be 20.8:1 to 57.7:1, alternatively 28.7:1 to 54.7:1, alternatively 20.8:1 to 28.8:1, alternatively 28.7:1 to 57.7:1.

(E) Trialkylborate esters

The starting material (E) in the hydrosilylation reaction curable composition is of the formula B (OR ^A ) ₃ Trialkyl borates of (1), wherein each R ^A Is independently selectedAn alkyl group having 1 to 30 carbon atoms, alternatively 1 to 12 carbon atoms, alternatively 1 to 6 carbon atoms. The alkyl group may be methyl, ethyl, propyl (e.g., isopropyl or n-propyl), butyl (e.g., isobutyl, n-butyl, tert-butyl or sec-butyl), pentyl (e.g., isopentyl, neopentyl or tert-pentyl), hexyl, branched or cyclic alkyl groups having 6 carbon atoms such as cyclopentyl or cyclohexyl. Examples of suitable trialkylborates include trimethyl borate, triethyl borate, tributyl borate, and combinations of two or more thereof. Alternatively, the trialkyl borate may be triethyl borate.

Trialkyl borates are known in the art and can be prepared by known methods such as those described in U.S. patent 3,020,308 to Stange. Trialkylborates are also commercially available, for example triethylborate is available from Shanghai Mieered chemical technology Co., ltd (Meryer (Shanghai) Chemical Technology Co., ltd.), and trialkylborate additives for silicone compositions are also known in the art, such as DOWSIL ^TM 7429PSA, which is available from the dow silicone company (Dow Silicones Corporation).

The amount of (E) trialkyl borate added to the hydrosilylation curable composition is from 0.05 to 4.64 weight percent based on the combined weight of starting materials (A) to (F). Alternatively, the amount of (E) trialkyl borate may be at least 0.05 wt%, alternatively at least 0.5 wt% and alternatively at least 0.8%; meanwhile, the amount may be at most 4.64 wt%, alternatively at most 4 wt%, alternatively at most 2 wt%, alternatively at most 1.5 wt%, alternatively at most 1.0 wt%, on the same basis. Alternatively, the amount of (E) trialkyl borate may be from 0.5 wt.% to 4.64 wt.% and alternatively from 0.8 wt.% to 4.64 wt.% on the same basis.

(F) Hydrosilylation reaction inhibitors

Starting material (F) is optionally a hydrosilylation reaction inhibitor (inhibitor) that can be used to alter the rate of the hydrosilylation reaction, as compared to a composition comprising the same starting material but omitting the inhibitor. The starting material (F) may be selected from the group consisting of: (F-1) alkynol, (F-2) silylated alkynol, (F-3) alkene-alkyne compound, (F-4) triazole, (F-5) phosphine, (F-6) thiol, (F-7) hydrazine, (F-8) amine, (F-9) fumarate, (F-10) maleate, (F-11) ether, (F-12) carbon monoxide, (F-13) alkenyl-functional siloxane oligomer, and (F-14) combinations of two or more thereof. Alternatively, the hydrosilylation reaction inhibitor may be selected from the group consisting of: (F-1) alkynols, (F-2) silylated alkynols, (F-9) fumarates, (F-10) maleates, (F-13) carbon monoxide, (F-14) combinations of two or more thereof.

Examples of alkynols are: 3, 5-dimethyl-1-hexyn-3-ol, 1-butyn-3-ol, 1-propyn-3-ol, 2-methyl-3-butyn-2-ol, 3-methyl-1-butyn-3-ol, 3-methyl-1-pentyn-3-ol, 3-phenyl-1-butyn-3-ol, 4-ethyl-1-octyn-3-ol, 3, 5-dimethyl-1-hexyn-3-ol, and 1-ethynyl-1-cyclohexanol, and combinations thereof. Alkynols are known in the art and are commercially available from a variety of sources, see for example U.S. patent 3,445,420 to Kookootsedes et al. Alternatively, the inhibitor may be a silylated acetylenic compound. Without wishing to be bound by theory, it is believed that the addition of the silylated acetylenic compound reduces yellowing of the reaction product produced by the hydrosilylation reaction compared to the reaction product resulting from hydrosilylation of starting materials that do not comprise the silylated acetylenic compound or comprise an organic acetylenic alcohol inhibitor such as those described above. Examples of silylated acetylenic compounds are (3-methyl-1-butyn-3-yloxy) trimethylsilane, ((1, 1-dimethyl-2-propynyl) oxy) trimethylsilane, bis (3-methyl-1-butyn-3-oxy) dimethylsilane, bis (3-methyl-1-butyn-3-oxy) silane methylvinylsilane, bis ((1, 1-dimethyl-2-propynyl) oxy) dimethylsilane, methyl (tris (1, 1-dimethyl-2-propynyloxy)) silane, methyl (tris (3-methyl-1-butyn-3-oxy)) silane, (3-methyl-1-butynyl-3-oxy) dimethylphenylsilane, (3-methyl-1-butyn-3-oxy) dimethylhexenylsilane, (3-methyl-1-butyn-3-oxy) triethylsilane, bis (3-methyl-1-but-3-oxy) methyltrifluoropropylsilane, (3, 5-dimethyl-3-butynyl-3-oxy) silane, methyl-1-butynyl-3-oxy) phenylsilane, (3-phenyl-1-butyn-3-oxy) dimethylphenylsilane, (3-phenyl-1-butyn-3-oxy) dimethylvinylsilane, (3-phenyl-1-butyn-3-oxy) dimethylhexenylsilane, (cyclohexyl-1-ethyne-1-oxy) dimethylvinylsilane, (cyclohexyl-1-ethyne-1-oxy) diphenylmethylsilane, (cyclohexyl-1-ethyne-1-oxy) trimethylsilane, and combinations thereof. Silylated acetylenic compounds useful herein as inhibitors can be prepared by methods known in the art, for example, U.S. patent 6,677,407 to Bilgrien et al discloses silylating alkynols by reacting the alkynols described above with chlorosilanes in the presence of acid acceptors.

Alternatively, the inhibitor may be an ene-yne compound, such as 3-methyl-3-penten-1-yne, 3, 5-dimethyl-3-hexen-1-yne; and combinations thereof. Alternatively, the inhibitor may comprise a triazole, exemplified by benzotriazole. Alternatively, the inhibitor may comprise a phosphine. Alternatively, the inhibitor may comprise a thiol. Alternatively, the inhibitor may comprise hydrazine. Alternatively, the inhibitor may comprise an amine. Examples of amines are tetramethyl ethylenediamine, 3-dimethylamino-1-propyne, N-methyl propargylamine, 1-ethynylcyclohexylamine, or combinations thereof. Alternatively, the inhibitor may comprise a fumarate. The fumarate includes dialkyl fumarates such as diethyl fumarate, dienyl fumarates such as diallyl fumarate, dialkoxyalkyl fumarates such as bis (methoxymethyl) ethyl fumarate. Alternatively, the inhibitor may comprise a maleate ester. The maleic acid esters include dialkyl maleates such as diethyl maleate, dienyl maleates such as diallyl maleate, and dialkoxyalkyl maleates such as bis (methoxymethyl) ethyl maleate. Alternatively, the inhibitor may comprise an ether.

Alternatively, the inhibitor may comprise carbon monoxide. Alternatively, the inhibitor may comprise an alkenyl-functional siloxane oligomer, which may be cyclic or linear, such as methyl vinyl cyclosiloxane, exemplified by 1,3,5, 7-tetramethyl-1, 3,5, 7-tetravinyl cyclotetrasiloxane, 1,3,5, 7-tetramethyl-1, 3,5, 7-tetrahexenyl cyclotetrasiloxane, 1, 3-divinyl-1, 3-diphenyl-1, 3-dimethyl disiloxane; 1, 3-divinyl-1, 3-tetramethyldisiloxane; and combinations of two or more thereof. Compounds useful as inhibitors as described above are commercially available, for example, from Sigma Aldrich inc or Gelest inc (Gelest, inc.) and are known in the art, see for example us patent 3,989,667 to Lee et al. Examples of inhibitors suitable for use herein are those described as stabilizer E in U.S. patent application publication 20007/0099007 paragraphs [0148] to [0165 ].

The amount of inhibitor will depend on a variety of factors including the desired pot life, whether the composition is a one-part or multi-part composition, the particular inhibitor used, and the choice and amount of (C) hydrosilylation catalyst. However, when present, the amount of the (F) inhibitor may be in the range of 0% to 5%, alternatively 0% to 1%, alternatively 0.001% to 1%, alternatively 0.01% to 0.5%, and alternatively 0.0025% to 0.025%, based on the combined weight of the starting materials (a) to (F) in the hydrosilylation reaction curable composition.

(G) Solvent(s)

The hydrosilylation reaction curable composition further comprises a starting material (G) solvent. The solvent may be an organic solvent such as a hydrocarbon, ketone, acetate, ether and/or cyclic siloxane having an average degree of polymerization of 3 to 10. Suitable hydrocarbons for the solvent may be (G-1) aromatic hydrocarbons such as benzene, toluene or xylene; (G-2) aliphatic hydrocarbons such as hexane, heptane, octane or isoparaffins; or (G-3) combinations thereof. Alternatively, the solvent may be a glycol ether such as propylene glycol methyl ether, dipropylene glycol methyl ether, propylene glycol n-butyl ether. Suitable ketones include acetone, methyl ethyl ketone or methyl isobutyl ketone. Suitable acetates include ethyl acetate or isobutyl acetate. Suitable ethers include diisopropyl ether or 1, 4-dioxolane. Suitable cyclic siloxanes having a degree of polymerization of from 3 to 10, alternatively 3 to 6, include hexamethylcyclotrisiloxane, octamethyltetrasiloxane and/or decamethylcyclopentasiloxane. Alternatively, the solvent may be selected from the group consisting of benzene, toluene, xylene, heptane, ethylbenzene, ethyl acetate, and combinations of two or more thereof.

The amount of solvent will depend on a variety of factors including the type of solvent selected and the amount and type of other starting materials selected for the hydrosilylation reaction curable composition. However, the amount of solvent may be in the range of >0% to 90%, alternatively 0% to 60%, alternatively 20% to 60%, alternatively 45% to 65%, and alternatively 50% to 60%, based on the combined weight of all starting materials in the hydrosilylation reaction curable composition. Solvents may be added during the preparation of the hydrosilylation reaction curable composition, for example to aid in mixing and delivery of one or more of the above-described starting materials. All or a portion of the solvent may be added together with one or more of the other starting materials. For example, the polyorganosilicate resin and/or the hydrosilylation reaction catalyst may be dissolved in a solvent prior to combination with other starting materials in the hydrosilylation reaction curable composition. All or a portion of the solvent may optionally be removed after the hydrosilylation reaction curable composition is prepared.

(H) Fixing additive

The starting material (H) in the hydrosilylation reaction curable composition is an anchoring additive. Without wishing to be bound by theory, it is believed that the anchoring additive will promote adhesion to the substrate by the silicone pressure sensitive adhesive prepared by curing the hydrosilylation reaction curable composition described herein.

Suitable anchoring additives for starting material (H) include silane coupling agents such as methyltrimethoxysilane, vinyltrimethoxysilane, allyltrimethoxysilane, 3-methacryloxypropyl trimethoxysilane, 3-aminopropyl trimethoxysilane, N- (2-aminoethyl) -3-aminopropyl trimethoxysilane, bis (trimethoxysilyl) propane and bis (trimethoxysilyl) hexane; and mixtures or reaction mixtures of the silane coupling agents. Alternatively, the anchoring additive may be tetramethoxysilane, tetraethoxysilane, dimethyldimethoxysilane, methylphenyl dimethoxysilane, methylphenyl diethoxysilane, phenyl trimethoxysilane, methyl triethoxysilane, vinyl triethoxysilane, allyl triethoxysilane, 3-glycidoxypropyl trimethoxysilane, 3-glycidoxypropyl triethoxysilane, or 3-methacryloxypropyl trimethoxysilane.

Examples of other suitable anchoring additives are the reaction products of vinyl alkoxysilanes with epoxy functional alkoxysilanes; reaction products of vinyl acetoxysilane with epoxy functional alkoxysilanes; and combinations of polyorganosiloxanes having at least one aliphatic unsaturated hydrocarbon group and at least one hydrolyzable group per molecule with epoxy-functional alkoxysilanes (e.g., physical blends and/or reaction products) (e.g., combinations of hydroxyl-terminated vinyl-functional polydimethylsiloxane with glycidoxypropyl trimethoxysilane).

Exemplary fixation additives are known in the art, such as U.S. patent 9562149, U.S. patent application publication No. 2003/0088042, U.S. patent application publication No. 2004/0254274, U.S. patent application publication No. 2005/0038188, U.S. patent publication No. 2012/0328863 [0091 ]]Paragraph and U.S. patent publication 2017/023612 [0041 ]]A segment; and in european patent 0 556 023. Fixing additives are commercially available. For example SYL-OFF ^TM 9250、SYL-OFF ^TM 9176、SYL-OFF ^TM 297 and SYL-OFF ^TM 397 is available from Midland ceramic silicone company (Dow Silicones Corporation, midland, michigan, USA). Other exemplary anchoring additives include (G-1) vinyltriacetoxy silane, (G-2) glycidoxypropyl trimethoxysilane, and (G-3) (G-1) and (G-2) in combination. Such a combination (G-3) may be a mixture and/or a reaction product.

The amount of the anchoring additive depends on a variety of factors, including the type of substrate to which the silicone pressure sensitive adhesive will adhere. However, when present, the amount of fixation additive may be from 0.5% to 5%, alternatively from 0.5% to 3%, and alternatively from 0.5% to 2.5%, based on the combined weight of all starting materials in the hydrosilylation reaction curable composition excluding solvent.

Method for preparing hydrosilylation reaction curable compositions

The hydrosilylation reaction curable composition can be prepared by a method comprising the following processes: all starting materials as described above are combined by any convenient means, such as mixing at room temperature or elevated temperature. For example, the hydrosilylation reaction inhibitor may be added prior to the hydrosilylation reaction catalyst when the hydrosilylation reaction curable composition is to be prepared at an elevated temperature and/or the hydrosilylation reaction curable composition is to be prepared as a one-part composition.

The method may further include delivering one or more starting materials (e.g., a hydrosilylation reaction catalyst and/or a polyorganosilicate resin) in a solvent that is soluble in the solvent when combined with one or more other starting materials in the hydrosilylation reaction curable composition. Those skilled in the art will appreciate that if it is desired that the resulting hydrosilylation reaction curable composition will be solvent-free (i.e., will contain no solvent or may contain trace amounts of residual solvent from the delivery of the starting materials), then the solvent may be removed after mixing two or more of the starting materials, and in such a case, no solvent is intentionally added to the hydrosilylation reaction curable composition.

Alternatively, the hydrosilylation-curable composition may be prepared as a multipart composition, for example, when the hydrosilylation-curable composition is to be stored for a longer period of time prior to use, for example up to 6 hours prior to application of the hydrosilylation-curable composition to an optical silicone elastomer or other substrate. In the multi-part composition, the hydrosilylation reaction catalyst is stored in a separate part from any starting material having silicon-bonded hydrogen atoms (e.g., a polyorganosiloxane) and the parts are combined immediately prior to use of the hydrosilylation reaction curable composition.

For example, the multipart composition may be prepared by the following process: the starting materials comprising the polydiorganosiloxane gum component, the polyorganosiloxane, and optionally at least some of one or more of the other starting materials described above (except for the hydrosilylation reaction catalyst) are combined by any convenient means, such as mixing, to form the base portion. The curing agent may be prepared by combining starting materials comprising at least some of the following materials in any convenient manner, such as mixing: polydiorganosiloxane gums, hydrosilylation catalysts, and optionally one or more of the other starting materials described above (in addition to the polyorganosiloxane). The starting materials may be mixed at ambient or elevated temperature. The hydrosilylation reaction inhibitor may be contained in one or more of the base portion, the curative portion, or a separate additional portion. The polyorganosiloxane resin may be added to the matrix part, the curing agent part or a separate additional part. Alternatively, a polyorganosilicate resin may be added to the base portion. A solvent may be added to the base portion. Alternatively, the starting materials including some or all of the polyorganosilicate resin and solvent may be added in a separate additional part. When a two-part composition is used, the weight ratio of the amount of the base part to the amount of the curative part may be in the range of 1:1 to 10:1. The hydrosilylation reaction curable composition will cure via a hydrosilylation reaction to form a silicone pressure sensitive adhesive.

Application method

The above method may further comprise one or more additional steps. The hydrosilylation reaction curable composition prepared as described above can be used to form an adhesive article, such as a silicone pressure sensitive adhesive, on a substrate (prepared by curing a hydrosilylation reaction curable composition as described above). Thus, the method may further comprise applying the hydrosilylation reaction curable composition to a substrate.

The hydrosilylation reaction curable composition can be applied to the substrate by any convenient means. For example, the hydrosilylation reaction curable composition is applied to the substrate by a gravure coater, comma coater, offset gravure coater, roll coater, reverse roll coater, air knife coater, curtain coater, or slot die.

The substrate may be any material that can withstand the curing conditions (described below) used to cure the hydrosilylation reaction curable composition to form a silicone pressure sensitive adhesive on the substrate. For example, any substrate that can withstand a heat treatment at a temperature equal to or greater than 120 ℃, alternatively 150 ℃, is suitable. Examples of materials suitable for such substrates include polymeric films such as Polyimide (PI), polyetheretherketone (PEEK), polyethylene naphthalate (PEN), liquid crystalline polyaramid, polyamideimide (PAI), polyether sulfide (PES), polyethylene terephthalate (PET), polycarbonate (PC), polymethyl methacrylate (PMMA), thermoplastic Polyurethane (TPU), polyethylene (PE), or polypropylene (PP). Alternatively, the substrate may be glass. Alternatively, the substrate may be a release liner, for example, when a silicone pressure sensitive adhesive is to be used in a dry casting process. The thickness of the substrate is not critical, however, the thickness may be 5 μm to 300 μm, alternatively 10 μm to 200 μm. Alternatively, the substrate may be selected from the group consisting of PI, PET, TPU, PMMA and optical silicone elastomers.

Optical silicone elastomers are known in the art and are described, for example, in U.S. patent 8,859,693 to Hasegawa et al and U.S. patent 8,853,332 to Akitomo et al. Optical silicone elastomers are commercially available. For example, an optical silicone elastomer SILATIC ^TM MS-1001, MS-1002, MS-1003, and MS-4002, and MS-4007 are moldable optical silicone elastomers, and SYLGARD ^TM 182. 184 and 186 are other optical silicone elastomers, all of which are commercially available from silicone company, midland, michigan, USA, dow Silicones Corporation.

To improve the bonding of the silicone pressure sensitive adhesive to the substrate, the method for forming the adhesive article may also optionally include treating the substrate prior to applying the hydrosilylation reaction curable composition. The treatment of 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 prior to applying the hydrosilylation reaction curable composition to the substrate.

The methods described herein can also optionally include applying a removable release liner to the silicone pressure sensitive adhesive opposite the substrate, for example, to protect the silicone pressure sensitive adhesive prior to use of the adhesive article. The release liner may be before, during, or after curing the hydrosilylation reaction curable composition; alternatively applied after curing. The adhesive article may be a component for a flexible display device, such as an optical component.

Use of silicone pressure sensitive adhesives in components of flexible display devices

Fig. 1 shows a partial cross section of a flexible display device component (100). The component (100) includes a silicone pressure sensitive adhesive (102) having a surface (102 a) and an opposing surface (102 b). The opposing surface (102 b) of the silicone pressure sensitive adhesive (102) adheres to the surface (103 a) of the optical silicone elastomer (103) with a peel adhesion of >500g/in, as measured by the test method described in the examples below. The silicone pressure sensitive adhesive (102) may have a thickness of 10 μm to 200 μm. The silicone pressure sensitive adhesive (102) adheres to a substrate (101) having a surface (101 a) and an opposing surface (101 b). A surface (102 a) of the silicone pressure sensitive adhesive (102) contacts an opposing surface (101 b) of the substrate (101). The substrate (101) may be selected from the group consisting of PI, PET, TPU, PMMA and an optical silicone rubber (which may be the same as or different from the optical silicone rubber (103)) and may have a thickness of 10 μm to 200 μm.

The hydrosilylation reaction curable compositions and methods described above can be used to manufacture flexible display device components (100) via wet casting. For example, the hydrosilylation reaction curable composition can be applied to the opposing surface (101 b) of the substrate (101) and cured to form the silicone pressure sensitive adhesive (102). Alternatively, the hydrosilylation reaction curable composition described herein can be applied to the surface (103 a) of the optical silicone elastomer (103) and cured to form the silicone pressure sensitive adhesive (102). Alternatively, the hydrosilylation reaction curable composition can be applied to the surface of a release liner and cured to form a silicone pressure sensitive adhesive (102). Thereafter, the optical silicone rubber (103) may be in contact with the opposite surface (102 b) of the silicone pressure sensitive adhesive (102), and the substrate (101) may be in contact with the surface (102 a) of the silicone pressure sensitive adhesive (102).

Examples

The following examples are presented to illustrate the invention to those skilled in the art and should not be construed as limiting the invention as set forth in the claims. The starting materials used herein are described in table 1.

TABLE 1 starting materials

/>

In Table 1, the trademark DOWSIL ^TM 、SILASTIC ^TM And SYL-OFF ^TM Is commercially available from the Dow organosilicon company (Dow Silicones Corporation).

In this reference example 1, samples of hydrosilylation reaction curable compositions were prepared as follows using the starting materials and amounts shown in table 2 below. Amounts are in parts by weight unless otherwise indicated. The starting material (a) polydiorganosiloxane gum component and starting material (B) polyorganosiloxane resin component are dissolved in the (G) solvent with mixing until the resulting mixture is homogeneous. The starting material (F) hydrosilylation reaction inhibitor is then thoroughly blended into the above mixture. And then the starting material (E) trialkyl borate is thoroughly blended into the above mixture. And then thoroughly blending the starting material (D) polyorganosiloxane into the above mixture. And optionally then thoroughly blending the starting material (H) anchoring additive (if used) into the above mixture. Finally, the starting material (C) hydrosilylation catalyst is added and mixed until homogeneous. All starting materials were mixed at RT. The starting materials and their amounts (by weight) are shown in table 2 below.

TABLE 2 hydrosilylationCurable composition

The hydrosilylation reaction curable compositions in table 2 contained a small amount of residual solvent 1 that was introduced with the starting material.

DOWSIL is applied to a substrate prior to applying the hydrosilylation reaction curable composition to the substrate ^TM 7499 The PSA primer was coated onto the substrate at a thickness sufficient to provide a dry coat weight of 0.20gsm after heating in an oven at 120 ℃ for 0.5 minutes. The primer layer on the substrate provides sufficient adhesion between the substrate and the cured silicone pressure sensitive adhesive. In this reference example 2, a hydrosilylation reaction curable composition was coated on a substrate and cured according to the following procedure. Each sample prepared as described above was applied to a 50 μm thick PET film of sufficient thickness to provide a dry coat weight of 50 μm after heating in an oven at 140 ℃ for 2 minutes. After curing, the tape samples were cut 1 inch wide for peel adhesion testing in the following steps.

The resulting tape sample is applied to a substrate such that the silicone pressure sensitive adhesive contacts the substrate. The substrates were SUS and Si rubber B, and the samples were held at RT for 20 minutes after the silicone pressure sensitive adhesive was contacted with the substrate, and then tested. The test was repeated but the samples were kept at 70 ℃ for 1 day before testing.

TABLE 3 calculated and measured values for hydrosilylation curable compositions

In this reference example 3, samples prepared as described in reference example 2 were tested as follows. Each tape sample prepared as described above was tested for adhesion to SUS and Si rubber B substrates by peeling each tape from the substrate and checking whether any silicone pressure sensitive adhesive was transferred from the PET film to the substrate. An adhesion/peel tester AR-1500 was used. The width of each PET sheet was 1 inch. The peel speed and peel angle were 0.3m/min and 180 °, respectively. Units are grams per inch. The results are shown in table 4 below.

The adhesion test method to SUS refers to test standard ASTM D3330. The stainless steel plate was cleaned with a solvent. A strip sample (1 inch wide) was applied to a stainless steel plate. The rolls were rolled twice in each direction at a speed of 10mm/s with a standard 2kg test roll. After 20 minutes dwell time, the samples were peeled from the steel plate at a rate of 300mm/min at a peel angle of 180℃using AR-1500.

The adhesion test method for silicone rubber B refers to test standard ASTM D3330. Cleaning the silicone rubber sheet with a solvent. Tape samples (1 inch, i.e., 25.4mm wide) were applied to silicone rubber sheets. The rolls were rolled twice in each direction at a speed of 10mm/s with a standard 2kg test roll. After 20 minutes dwell time, the sample was peeled from the silicone rubber sheet at a rate of 300mm/min using AR-1500 at a 180 peel angle.

Adhesion to silicone rubber (70-1D) test method refers to test standard ASTM D3330. Cleaning the silicone rubber sheet with a solvent. Tape samples (1 inch, i.e., 25.4mm wide) were applied to silicone rubber sheets. The rolls were rolled twice in each direction at a speed of 10mm/s with a standard 2kg test roll. After aging the sample at 70℃for one day (24 hours), the sample was peeled from the silicone rubber sheet at a rate of 300mm/min using AR-1500 at a peeling angle of 180 ℃.

Rheology data (Tg, -20 ℃, 25 ℃ and G' test method at 100 ℃) refer to test Standard ASTM D4440-15.

Cured, pure silicone pressure sensitive adhesive films (no substrate) each having a thickness of 0.5mm to 1.5mm were prepared for rheological performance testing on a rheometer TA DHR-2 or ARES-G2 on parallel plates 8mm in diameter. The loss modulus G 'and storage modulus G' at different temperatures (i.e., 200 ℃ to-80 ℃) were measured in an oscillating mode by a temperature ramp program at 1Hz with a cooling rate of 3 ℃/min and a strain of 0.25%. Tan delta was calculated by G "/G'. The glass transition temperature is defined as the temperature at the peak point of tan delta. The results are shown in table 4 below.

TABLE 4 results

Sample of	Comparative example 1	Comparative example 2	Comparative example 3	Working example 1	Working example 2	Working example 3	Working example 4
								SUS pair (RT-20 min)	2175.0	1362.9	1040.7	1510.0	883.7	1498.2	578.8
For Si rubber B (RT-20 min)	380.5	314.4	240.3	744.0	713.5	504.1	958.7
								For Si rubber B (70-1 d)	613.2	490.5	474.4	1238	1198	865	1500.8
Tg(℃)	9.9	-4.86	-8.80	-7.60	-8.14	-2.10	-62.20
								G’(-20℃)(kPa)	920.2	783.2	550.0	690.0	510.0	852.0	39.0
G’(25℃)(kPa)	51.04	37.4	29.5	35.1	32.8	42.5	31.0
								G’(100℃)(kPa)	20.1	21.5	22.3	25.6	22.13	21.1	28.6

Industrial application

The above examples demonstrate that hydrosilylation reaction curable compositions that cure to form silicone pressure sensitive adhesives having desirable adhesive properties can be prepared: adhesion to stainless steel >500 g/inch, adhesion to optical silicone elastomer at RT >500 g/inch, and adhesion to optical silicone elastomer after one day aging of silicone pressure sensitive adhesive on optical silicone rubber at 70 ℃ >800 g/inch. The high adhesion forces make the interface between the silicone pressure sensitive adhesive and the substrate (adherend) strong enough to resist delamination in repeated deformation tests (e.g., by folding, bending, rolling, or stretching tests) of the flexible display device. The silicone pressure sensitive adhesive may also have a Tg of less than or equal to 0 ℃, a G ' <1MPa at-20 ℃, a G ' <50kPa at 25 ℃, and a G ' <50kPa at 100 ℃. The low Tg and low G' at a wide temperature range makes silicone pressure sensitive adhesives suitable for use at a wide temperature range with lower stress applied to other layers during repeated deformation testing (e.g., by folding, bending, rolling, and stretching tests). This combination of properties makes silicone pressure sensitive adhesives suitable for use in flexible display devices, particularly optical components of flexible display devices. The combination of silicone pressure sensitive adhesives prepared as described herein with optical silicone elastomers results in articles for flexible display devices having excellent reliability tests when subjected to repeated deformation tests (e.g., fold, bend, roll, and stretch tests) due to the excellent properties of silicone elastomers to resist repeated folding, bending, rolling, and stretching.

Definition and use of terms

All amounts, ratios, and percentages herein are by weight unless otherwise indicated. The summary and abstract of the specification are hereby incorporated by reference. The articles "a," "an," and "the" all refer to one(s) or more, unless the context of the specification indicates otherwise. The transitional phrases "comprising," "consisting essentially of … (consisting essentially of)" and "consisting of … (consisiting of)" are used as described in chapter 2111.03i., chapters ii and III of revision 08.2017, last revised in month 1 of 2018, according to patent review program handbook ninth edition (Patent Examining Procedure Ninth Edition). The use of "e.g.", "such as" and "including" to list exemplary examples is not meant to be limited to only the examples listed. Thus, "for example" or "such as" means "for example, but not limited to," or "such as, but not limited to," and encompasses other similar or equivalent examples. Abbreviations used herein have the definitions in table 5.

TABLE 5 abbreviations

The invention has been described in an illustrative manner, and it is to be understood that the terminology which has been used is intended to be in the nature of words of description rather than of limitation. To the extent any markush group is relied upon herein to describe a particular feature or aspect, different, specific and/or unexpected results can be obtained from each member of the corresponding markush group independently of all other markush members. Each member of the markush group may be relied upon individually and/or in combination and provide adequate support for specific embodiments within the scope of the appended claims.

Furthermore, any ranges and subranges relied upon in describing the present invention independently and collectively fall within the scope of the appended claims, and are understood to describe and contemplate all ranges within which all and/or part of values are included, even if such values are not explicitly written herein. Those skilled in the art will readily recognize that the recited ranges and subranges fully describe and enable various embodiments of the invention, and that such ranges and subranges can be further delineated into relevant halves, thirds, quarters, fifths, and any other subranges included within the range. As just one example, the range of "0.05 to 4.64" for the amount of trialkyl borates may be further delineated into the lower third, i.e., "0.05 to 1.58", the middle third, i.e., "1.59 to 3.11", and the upper third, i.e., "3.12 to 4,64", and alternatively, the ranges "0.05 to 4.64" include the sub-ranges "0.05 to 0.98", "0.78 to 0.98", and "0.98 to 4.64", as well as the individual values 0.05, 0.78, 0.98, and 4.64, each individually and collectively within the scope of the appended claims, and may be relied upon individually and/or collectively and provide adequate support for specific embodiments within the scope of the appended claims. Furthermore, to the extent that such language is defined or modified, such as "at least," "greater than," "less than," "not exceeding," etc., it is understood that such language includes sub-ranges and/or upper or lower limits.

Claims

1. A hydrosilylation reaction curable composition for forming a silicone pressure sensitive adhesive, wherein the composition comprises:

(A) A polydiorganosiloxane gum component comprising

32.2 to 44.6% by weight of the unit formula (R) based on the combined weight of the starting materials (A) to (F) ^M ₂ R ^U SiO _1/2 ) ₂ (R ^M ₂ SiO _2/2 ) _a (A-1) aliphatically unsaturated polydiorganosiloxane gums, wherein each R ^M Is an independently selected monovalent hydrocarbon group of 1 to 30 carbon atoms free of aliphatic unsaturation; each R ^U A monovalent aliphatic unsaturated hydrocarbon group having 2 to 30 carbon atoms independently selected; and subscript a has a value sufficient to impart to the polydiorganosiloxane gum a plasticity of 20 mils (0.51 mm) to 80 mils (2.03 mm), wherein plasticity is measured based on ASTM D926 by applying a 1kg load to a spherical sample weighing 4.2g at 25 ℃ for 3 minutes, and the results are measured in thousandths of an inch (mil), and the procedure is performed based on ASTM D926, and

0 wt% to<1.2% by weight of unit formula ((HO) R ^M ₂ SiO _1/2 ) ₂ (R ^M ₂ SiO _2/2 ) _a’ (A-2) hydroxyl-terminated polydiorganosiloxane gums, wherein each R ^M Is an independently selected monovalent hydrocarbon group of 1 to 30 carbon atoms free of aliphatic unsaturation; each subscript a' has a value sufficient to impart plasticity to the polydiorganosiloxane gum of from 20 mils (0.51 mm) to 80 mils (2.03 mm); and is also provided with

(B) A polyorganosiloxane resin component comprising

44.8 to 58.9% by weight, based on the combined weight of starting materials (a) to (F), of the unit formula: (R) ^M ₃ SiO _1/2 ) _z (SiO _4/2 ) _o Z _p Wherein Z is a hydrolyzable group, subscript p is 0 to a value sufficient to impart a hydrolyzable group content of up to 2% to said end-capped resin, and subscripts Z and o have values such that Z>4、o>1, and the amount (z+o) has a value sufficient to provide the end-capped resin with a number average molecular weight of 500g/mol to 2,700 g/mol; and

(D) Unit type: (R) ^M ₂ SiO _2/2 ) _e (HR ^M SiO _2/2 ) _f (R ^M ₂ HSiO _1/2 ) _g (R ^M ₃ SiO _1/2 ) _h Is a polyorganosiloxane; wherein subscript e is greater than or equal to 0, subscript f is greater than or equal to 0, amount (e+f) is from 4 to 500, subscript g is 0, 1, or 2, subscript h is 0, 1, or 2, amount (g+h) =2, and amount (f+g) is greater than or equal to 3; wherein (D) the polyorganosiloxane is in an amount sufficient to provide a molar ratio of silicon-bonded hydrogen atoms of 20.8:1 to 57.7:1 to aliphatic unsaturated hydrocarbon groups of (A) the polydiorganosiloxane gum component { (D): ratio (A) }Presence;

0.05 to 4.64% by weight, based on the combined weight of starting materials (a) to (F), of (E) an alkyl borate;

0 to 5% by weight, based on the combined weight of the starting materials (a) to (F), of (F) a hydrosilylation reaction inhibitor;

2. The composition of claim 1 wherein in (a) the polydiorganosiloxane gum component, each R ^M An independently selected alkyl group having 1 to 6 carbon atoms; and is also provided with

Each R ^U Independently selected from the group consisting of vinyl, allyl, and hexenyl; and subscript a is sufficient to provide a plasticity number of from 30 mils (0.76 mm) to 70 mils (1.778 mm).

3. The composition of claim 1 wherein in (B) the polyorganosilicate resin component, each R ^M An independently selected alkyl group having 1 to 6 carbon atoms; each Z is OH; and the amount (z+o) has a value sufficient to provide the end-capped resin with a number average molecular weight of ∈2,700 g/mol.

4. The composition of claim 1, wherein (C) the hydrosilylation reaction catalyst comprises a Karstedt catalyst.

5. The composition of claim 1 wherein in (D) the polyorganosiloxane, each R ^M For independently selected alkyl groups having 1 to 6 carbon atoms, subscript g=0, and subscript h=2.

6. The composition of claim 1, wherein (E) the trialkyl borate comprises triethyl borate.

7. The composition according to any one of claims 1 to 6, wherein the composition is a multi-part composition comprising a base part and a hardener part, wherein the base part comprises starting materials a) and C); and the curative part comprises starting materials a) and D); and is also provided with

The composition further comprises starting materials B), E) and F) in one or more of the base part, the curative part or a separate additional part.

8. A wet casting process, the wet casting process comprising

1) Applying the composition according to any one of claims 1 to 6 to a substrate, and

2) Curing the composition to form the silicone pressure sensitive adhesive on the substrate.

9. A dry casting method includes

1) The composition according to any one of claims 1 to 6 is applied to a release liner,

2) Curing the composition to form the silicone pressure sensitive adhesive on the release liner, and

3) The silicone pressure sensitive adhesive is applied to a substrate.

10. The method of claim 8 or claim 9, wherein the substrate is an optical silicone elastomer.

11. The method of any one of claims 8 to 10, wherein the silicone pressure sensitive adhesive is optically clear.

12. An article prepared by the method of any one of claims 8 to 11.

13. The article of claim 12, wherein the article is part of a flexible display device.

14. A component of a flexible display device, the component comprising:

i) Optical silicone elastomer layer

II) a silicone pressure sensitive adhesive layer adhered to the optical silicone elastomer layer, wherein the silicone pressure sensitive adhesive layer is the product of the composition of any one of claims 1 to 5.