TW202307134A - Hydrosilylation curable polyorganosiloxane composition and methods for the preparation and use thereof in encapsulation films - Google Patents

Abstract

A hydrosilylation curable polyorganosiloxane composition can be heat cured to form a silicone encapsulation film. The silicone encapsulation film has Dk and modulus suitable for use in OLED displays. The silicone encapsulation film with a thickness of 1.8 mm to 2 mm may have a Dk < 2.8, a storage modulus < 1 MPa, and a Shore A 00 hardness > 12.

Description

Hydrosilylation curable polyorganosiloxane composition and preparation method and its use in encapsulation film

Cross-reference to related applications

This application claims priority to U.S. Provisional Patent Application Serial No. 63/229606 filed August 05, 2021 under 35 U.S.C. §119 (e). US Provisional Patent Application Serial No. 63/229606 is hereby incorporated by reference herein.

A hydrosilylation curable polyorganosiloxane composition can be cured to form a polysiloxane encapsulation film suitable for use in OLED displays. Provided are a method for preparing the composition and a method for using the composition to prepare a polysiloxane encapsulation film.

Encapsulation films are used in organic light emitting diode (OLED) displays to protect sensitive electronic components. Encapsulation films cover moisture-sensitive electronic components, such as organic light emitters, to prevent oxidation and physically protect the electronic components from damage caused by external forces.

The industry needs encapsulating films that have one or more of the following properties: optical transmission, fast cure, no or minimal outgas generation, and dimensional stability. The modulus affects the dimensional stability of the encapsulation film and also affects the ability to stack electronic components containing the encapsulation film. In addition, the dielectric constant (Dk) is a measure of the polarizability of a film. Encapsulation films with low Dk values can reduce parasitic capacitance, which is undesirable because parasitic capacitance increases power consumption. Therefore, the industry needs materials to make OLED encapsulation films with both low Dk and appropriate modulus values.

A method for forming a polysiloxane encapsulation film is provided. Polysiloxane encapsulation film is suitable for OLED displays. The method for forming a polysiloxane encapsulation film comprises: (1) Combining starting materials, these starting materials comprising: In the combined weight of starting materials (A), (B), (C), and (D) In total, 50% to 58.59% of (A) a polydiorganosiloxane polymer comprising a linear polymer having the unit formula (R ¹ ₂ R ² SiO _1/2 ) _a (R ¹ ₂ SiO _2/2 ) _b wherein R is an alkyl group having ¹ to 12 carbon atoms, ^R is an alkenyl group having 2 to 12 carbon atoms, and the subscripts a, b, and c represent the average number of units per molecule, and has the following values: a = 2, and 100 ≤ b ≤ 300; based on the combined weight of starting materials (A), (B), (C), and (D), 40% to 48.59% of (B) alkene A functional polyorganosilicate resin having the unit formula (R ¹ ₂ R ² SiO _1/2 ) _d (R ¹ ₃ SiO _2/2 ) _e (SiO _4/2 ) _f (HO _1/2 ) _g , Wherein R ¹ and R ² are as mentioned above, subscript e, f, g and h represent the mole fraction of each unit in the resin, and have the following values: d＞0, e≥0, f＞0, amount ( d + e + f) = 1, and the resin has a number average molecular weight of 1,500 g/mol to 15,000 g/mol, and the subscript g > 0, with the proviso that the subscript g has sufficient Values for resins with a hydroxyl content of 2% by weight; 1.4% to 2.5% by weight, based on the combined weight of the starting materials (A) to (D), of (C) a polyorganohydrogensiloxane having the unit formula ( R ¹ ₂ HSiO _1/2 ) _h (R ¹ ₃ SiO _1/2 ) _i (R ¹ ₂ SiO _2/2 ) _j (R ¹ HSiO _2/2 ) _k , wherein R ¹ is as above, subscript h, i, j, and k represent the average number of units per molecule, 0 ≤ h ≤ 2, 0 ≤ i ≤ 2, (h + i) = 2, 0 ≤ j < 10, 0 < k < 10, 0 < ( j + k) < 10, and 2 ≤ (h + k) ≤ 12; wherein (A) polydiorganosiloxane polymer, (B) alkenyl functional polyorganosilicate resin, and (C) polyorganosiloxane The amount of hydrosiloxane is sufficient to provide a weight ratio of silicon-bonded hydrogen atoms from (C) relative to alkenyl groups from the combination of (A) and (B) (SiH/Vi ratio) from 0.30 to 0.55; and Based on the combined weight of the starting materials (A) to (D), 0.01% to 0.02% by weight of (D) a hydrosilylation catalyst comprising platinum complexed with an alkenyl functional organosiloxane to form a hydrosilation compound Curing the polyorganosiloxane composition; (2) making the hydrosilylation curable polyorganosiloxane composition mold forming a film; and (3) curing the hydrosilylation curable polyorganosiloxane composition to form a polysiloxane encapsulating film.

The starting materials used in the above methods are described in detail below. (A) Polydiorganosiloxane polymer

The starting material (A) is a polydiorganosiloxane polymer. The polydiorganosiloxane polymer comprises (A-1) a linear polymer having the unit formula (R ¹ ₂ R ² SiO _1/2 ) _a (R ¹ ₂ SiO _2/2 ) _b , wherein R ¹ is a linear polymer having 1 An alkyl group having ² to 12 carbon atoms, R is an alkenyl group having 2 to 12 carbon atoms, the subscripts a, b, and c represent the number of units per molecule, the subscript a is 2, and the subscript b is 100 to 300.

Suitable alkyl groups for R ¹ may be linear, branched, cyclic, or a combination of two or more thereof. Alkyl groups are exemplified by: methyl, ethyl, propyl (including n-propyl and/or isopropyl), butyl (including n-butyl, tertiary butyl, secondary butyl, and/or isobutyl); pentyl, hexyl, heptyl, octyl, decyl, and dodecyl (and branched chain isomers with 5 to 12 carbon atoms), and the alkyl group is further modified by cycloalkyl , such as cyclopropyl, cyclobutyl, cyclopentyl, and cyclohexyl are exemplified. Alternatively, the alkyl group of ^R can be selected from the group consisting of: methyl, ethyl, propyl, and butyl; alternatively methyl, ethyl, and propyl; alternatively methyl and ethyl. Alternatively, the alkyl group of R ¹ may be methyl.

，其中下標y是0至10，替代地0至6，且*指示附著點（即，至矽原子）。替代地，各R ²可獨立地選自由乙烯基、烯丙基、及己烯基組成之群組。替代地，各R ²可獨立地選自由乙烯基及烯丙基組成之群組。替代地，各R ²可獨立地選自由乙烯基及己烯基組成之群組。替代地，各R ²可以是乙烯基。 The alkenyl group for ^R may have terminal alkenyl functionality, for example, ^R may have the formula

, where the subscript y is 0 to 10, alternatively 0 to 6, and * indicates the point of attachment (ie, to the silicon atom). Alternatively, each ^R2 can be independently selected from the group consisting of vinyl, allyl, and hexenyl. Alternatively, each ^R2 can be independently selected from the group consisting of vinyl and allyl. Alternatively, each ^R2 can be independently selected from the group consisting of vinyl and hexenyl. Alternatively, each ^R2 can be vinyl.

The starting material (A-1) may comprise an alkenyl functional polydiorganosiloxane, such as i) bis-dimethylvinylsiloxy terminated polydimethylsiloxane, ii) bis-dimethyl poly(dimethylvinylsiloxane/methylvinylsiloxane), iii) bis-dimethylvinylsiloxy terminated polymethylvinylsiloxane , iv) bis-trimethylsiloxy-terminated poly(dimethylsiloxane/methylvinylsiloxane), v) bis-trimethylsiloxy-terminated polymethylvinyl Siloxane, vi) bis-dimethylhexenylsiloxy terminated polydimethylsiloxane, vii) bis-dimethylhexenylsiloxy terminated poly(dimethylsiloxane Oxane/Methylhexenylsiloxane), viii) Bis-Dimethylhexenylsiloxane Terminated Polymethylhexenylsiloxane, ix) Bis-Trimethylsiloxane Poly(dimethylsiloxane/methylhexenylsiloxane), x) bis-trimethylsiloxy-terminated polymethylhexenylsiloxane, xi) bis-dimethicone Methylvinylsiloxy-terminated poly(dimethylsiloxane/methylhexenylsiloxane), xii) bis-dimethylhexenylsiloxy-terminated poly(dimethyl silicone/methylvinylsiloxane), and xiii) a combination of two or more of i) to xii). Alternatively, the starting material (A-1) may be selected from the group consisting of: i) bis-dimethylvinylsiloxy-terminated polydimethylsiloxane, vi) bis-dimethyl Hexenylsiloxy-terminated polydimethylsiloxanes, and combinations thereof. Alternatively, the starting material (A) may be bis-dimethylvinylsiloxy terminated polydimethylsiloxane.

Processes for the preparation of the abovementioned alkenyl-functional polydiorganosiloxanes as starting materials (A-1), such as hydrolysis and condensation of corresponding organohalosilanes and oligomers or equilibration of cyclic polydiorganosiloxanes, belong to the state of the art Known in the art, see, eg, US Patents 3,284,406; 4,772,515; 5,169,920; 5,317,072; and 6,956,087, which disclose the preparation of linear polydiorganosiloxanes having alkenyl groups. Examples of linear polydiorganosiloxanes having alkenyl groups are commercially available, for example, from Gelest Inc. of Morrisville, Pennsylvania, USA under the following trade names: DMS-V00, DMS-V03, DMS-V05, DMS-V21 , DMS-V6, DMS-V25, DMS-V-31, DMS-V33, DMS-V34, DMS-V35, DMS-V41, DMS-V42, DMS-V43, DMS-V46, DMS-V51, DMS-V52 .

The starting material (A) may optionally further comprise (A-2) a cyclic polymer having the unit formula (R ¹ R ² SiO _2/2 ) _c , wherein R ¹ and R ² are as described above, and the subscript c is 3 to 12. Those of ordinary skill in the art will recognize that cyclic polymers may be formed as by-products in the processes for making the linear alkenyl-functional polydiorganosiloxanes described above. Examples of cyclic alkenyl functional polydiorganosiloxanes include 2,4,6-trimethyl-2,4,6-trivinyl-cyclotrisiloxane, 2,4,6,8-tetramethyl 2,4,6,8-tetravinyl-cyclotetrasiloxane, 2,4,6,8,10-pentamethyl-2,4,6,8,10-pentaethenyl-cyclopentasiloxane Siloxane, and 2,4,6,8,10,12-hexamethyl-2,4,6,8,10,12-hexavinyl-cyclohexasiloxane. Such cyclic alkenyl functional polydiorganosiloxanes are known in the art and are commercially available, for example, from Sigma-Aldrich of St. Louis, Missouri, USA; Milliken of Spartanburg, South Carolina, USA; and other suppliers. The amount of starting material (A-2) may be 0 to 0.2% based on the combined weight of starting materials (A) to (D). The balance of the starting material (A) is the starting material (A-1) described above. (B) polyorganosilicate resin

The starting material (B) is a polyorganosilicate resin comprising monofunctional units of the formula ^RM ₃ SiO _1/2 and tetrafunctional units ("Q" units) of the formula SiO _4/2 , wherein each R ^M is an independently selected monovalent hydrocarbon group selected from ^R1 and ^R2 described above. Alternatively, each R ^M may be selected from methyl, vinyl, and phenyl. Alternatively, at least one-third, or at least two-thirds, of the groups of R ^M are methyl groups. Alternatively, the monofunctional unit can be exemplified by (Me ₃ SiO _1/2 ) and (Me ₂ ViSiO _1/2 ). Polyorganosilicate resins are soluble in solvents, such as liquid hydrocarbons, such as benzene, toluene, xylene, ethylbenzene, heptane, and combinations of two or more thereof; or in liquid organosilicon compounds, Such as low viscosity linear and cyclic polydiorganosiloxanes.

When prepared, the polyorganosilicate resin comprises the monofunctional and tetrafunctional units described above, and the polyorganosilicate resin further comprises units having silanol (silicon-bonded hydroxyl) groups, and may comprise the formula Si(OSiR ^M ₃ ) The neopentamer of ₄ , wherein R ^M is as described above. As in U.S. Patent No. 9,593,209, column 32, the Si ²⁹ nuclear magnetic resonance (Nuclear Magnetic Resonance, NMR) spectrometer described in Reference Example 2 can be used to measure the molar ratio of monofunctional units to tetrafunctional units, wherein the ratio is expressed as {M(resin)+(M(new pentamer)}/{Q(resin)+Q(new pentamer)}, and represent the resin part of the polyorganosilicate resin and the three parts of the new pentamer part The molar ratio of the total number of organosiloxy groups (M units) to the total number of silicate groups (Q units) in the resin fraction and neopentamer fraction.

The Mn of the polyorganosilicate resin depends on various factors including the type of hydrocarbyl represented by R ^M present. The Mn of polyorganosilicate resins refers to gel permeation chromatography (GPC) using gel permeation chromatography (GPC) according to the procedure in US Pat. The number average molecular weight measured at the peak. The Mn of the polyorganosilicate resin can be 1,500 or greater, alternatively greater than 3,000 g/mol, alternatively 1,500 g/mol to 15,000 g/mol, and alternatively 3,000 g/mol to 8,000 g/mol. Alternatively, the Mn of the polyorganosilicate resin may be 4,500 g/mol to 7,500 g/mol.

Polyorganosilicate resins can be prepared by any suitable method, such as cohydrolysis of corresponding silanes or by silica hydrosol capping methods. Polyorganosilicate resins can be prepared by silica hydrosol capping procedures such as Daudt et al., U.S. Patent No. 2,676,182; Rivers-Farrell et al., U.S. Patent No. 4,611,042; and Butler et al., U.S. Patent No. as disclosed in No. 4,774,310. The above-mentioned method of Daudt et al. involves reacting a silica hydrosol with a hydrolyzable triorganosilane (such as trimethylchlorosilane), a siloxane (such as hexamethyldisiloxane), or a mixture thereof under acidic conditions. reaction, and recovery of copolymers with monofunctional units and tetrafunctional units. The resulting copolymer generally contains 2 to 5 weight percent hydroxyl groups.

The intermediates used in the preparation of polyorganosilicate resins can be triorganosilanes and silanes with four hydrolyzable substituents or alkali metal silicates. Triorganosilanes may have the formula R ¹ ₃ SiX ¹ , wherein R ¹ is as described above and X ¹ represents a hydrolyzable substituent. A silane with four hydrolyzable substituents may have _the formula ^SiX24 , where each ^X2 is halogen, alkoxy, or hydroxyl. Suitable alkali metal silicates include sodium silicate.

Polyorganosilicate resins prepared as described above typically contain silicon-bonded hydroxyl groups, i.e., have the formula HOSi _3/2 and/or (HO) _x R ^M _(3-x) SiO _1/2 , where the subscript x is 1, 2 or 3. The concentration of silicon-bonded hydroxyl groups present in polyorganosilicate resins can be determined according to ASTM Standard E-168-16 (ASTM Standard E-168-16) using a Fourier Transform-Infra Red (FTIR) spectrometer . For certain applications, the amount of silicon-bonded hydroxyl groups may need to be less than 0.7%, alternatively less than 0.3%, alternatively less than 1%, and alternatively 0.3% to 0.8%. Silicon-bonded hydroxyl groups formed during the preparation of polyorganosilicate resins can be converted to trialkylsilanes by reacting the polysiloxane resin with silanes, disiloxanes, or disilazanes containing appropriate terminal groups. Oxyalkyl groups or different hydrolyzable groups. Silanes containing hydrolyzable groups can be added in molar excess in the amount required to react with the silicon-bonded hydroxyl groups on the polyorganosilicate resin.

Alternatively, the polyorganosilicate resin may have terminal aliphatic unsaturation (eg, alkenyl). Polyorganosilicate resins with terminal aliphatic unsaturation can be prepared by reacting the product of Daudt et al. with a capping agent containing unsaturated organic groups and without aliphatic unsaturation, The amount is sufficient to provide 3 to 30 mole percent unsaturated organic groups in the final product. Examples of capping agents include, but are not limited to, silazanes, siloxanes, and silanes. Suitable capping agents are known in the art and are exemplified in US Patent Nos. 4,584,355; 4,591,66; and 4,585,836. A single capping agent or a mixture of such agents can be used to prepare such resins.

The polyorganosilicate resin may have the unit formula (R ¹ ₂ R ² SiO _1/2 ) _d (R ¹ ₃ SiO _2/2 ) _e (SiO _4/2 ) _f (HO _1/2 ) _g , where R ¹ And R ² As mentioned above, the subscripts e, f, g, and h represent the mole fraction of each unit in the resin, and have the following values: d > 0, e > 0, f > 0, the amount (d + e + f) = 1, and the resin has a number average molecular weight of 1,500 g/mol to 15,000 g/mol, and the subscript g > 0, with the proviso that the subscript g has sufficient The value of the hydroxyl content of the resin. Polyorganosilicate resins are also commercially available, for example DOWSIL™ 6-3444 Int is available from DSC.

The amount of (B) polyorganosilicate resin in the hydrosilylation curable polyorganosiloxane composition depends on various factors, including the type and amount of (A) polydiorganosiloxane polymer, starting materials ( Alkenyl content of A) and (B), and silicon-bonded hydrogen content of starting material (C). However, the amount of (B) polyorganosilicate resin may be 40% to 48.59% based on the combined weight of the starting materials (A), (B), (C), and (D). (C) Polyorganohydrogensiloxane

The starting material (C) of the hydrosilylation-curable polyorganosiloxane composition is polyorganohydrogensiloxane. The polyorganohydrogensiloxane may have the unit formula (R ¹ ₂ HSiO _1/2 ) _h (R ¹ ₃ SiO _1/2 ) _i (R ¹ ₂ SiO _2/2 ) _j (R ¹ HSiO _2/2 ) _k , Wherein R ¹ is as above, subscript h, i, j, and k represent the average number of units per molecule, 0 ≤ h ≤ 2, 0 ≤ i ≤ 2, (h + i) = 2, 0 ≤ j < 10, 0 < k < 10, 0 < (j + k) < 10, and 2 ≤ (h + k) ≤ 12. Alternatively, h can be 0 and i can be 2. Alternatively, j may be 0 to 5, alternatively 1 to 4, alternatively 2 to 4, and alternatively 3 to 3.5. Alternatively, k may be 1 to 10, alternatively 2 to 9, alternatively 3 to 8, alternatively 4 to 7, and alternatively 5 to 6.

Polyorganohydrogensiloxanes suitable for use herein are exemplified by (i) bis-dimethylhydrogensiloxy terminated poly(dimethylsiloxane/methylhydrogensiloxane), ( ii) bis-dimethylhydrogensiloxy-terminated polymethylhydrogensiloxane, (iii) bis-trimethylsiloxy-terminated poly(dimethylsiloxane/methylhydrogensiloxane alkane), (iv) bis-trimethylsiloxy-terminated polymethylhydrogensiloxane, (v) α-dimethylhydrogensiloxy-ω-trimethylsiloxy-terminated polymethylhydrogensiloxane (dimethylsiloxane/methylhydrogensiloxane), (vi) α-dimethylhydrogensiloxy-ω-trimethylsiloxy-terminated polymethylhydrogensiloxane, and ( vii) A combination of two or more thereof.

Polyorganohydrogensiloxanes are also commercially available, such as those available from Gelest, Inc of Morrisville, Pennsylvania, USA, for example HMS-H271(i), HMS-071(iii), HMS-993(iv); HMS-301 and HMS-301 R (iii), HMS-031 (iii), HMS-991 (iv), HMS-992 (iv), HMS-993 (iv), HMS-082 (iii), HMS-151 (iii), HMS-013 (iii), HMS-053 (iii), HAM-301 (octyl functionality), and HMS-HM271 (v). Alternatively, the polyorganohydrogensiloxane used herein may be selected from the group consisting of (iii) bis-trimethylsiloxy terminated poly(dimethylsiloxane/methylhydrogensiloxane ), (iv) bis-trimethylsiloxy terminated polymethylhydrogensiloxane, and combinations thereof. Polyorganohydrogensiloxanes are also commercially available from DSC, such as DOWSIL™ 6-3570 polymer. Methods suitable herein for preparing polyorganohydrogensiloxanes, such as the hydrolysis and condensation of organohalosilanes, are well known in the art, as exemplified in U.S. Patent No. 2,87,218 to Speier et al; Patent No. 3,957,713; and US Patent No. 4,329,273 to Hardman et al.

The silicon-bonded hydrogen (Si-H) content of polyorganohydrogensiloxanes can be determined using quantitative infrared analysis according to ASTM E168. The silicon-bonded hydrogen to alkenyl (eg, vinyl) ratio (ie, SiH/Vi ratio) is important when relying on the hydrosilylation reaction curing process. Usually, this is determined by calculating the total weight % of alkenyl groups (such as vinyl [V]) in the composition and the total weight % of silicon-bonded hydrogen [H] in the composition, and since the molecular weight of hydrogen is 1 and the molecular weight of vinyl is 27, then the molar ratio [H]/[V] of silicon-bonded hydrogen to vinyl is 27. The aforementioned starting materials (A), (B), and (C) may be selected to provide a SiH/Vi ratio of 0.3 to 0.55, alternatively 0.31 to 0.53, alternatively 0.4 to 0.5, and alternatively 0.41 to 0.49. (D) Catalyst for hydrosilylation reaction

The starting material (D) in the hydrosilylation-curable polyorganosiloxane composition is a hydrosilylation reaction catalyst. This catalyst will facilitate the reaction between the alkenyl groups in the starting materials (A) and (B) and the silicon-bonded hydrogen atoms in the starting materials (C) and (B). The catalyst contains platinum group metals. The platinum group metal may be selected from the group consisting of platinum, rhodium, ruthenium, palladium, osmium, and iridium. Alternatively, the platinum group metal may be platinum. For example, the hydrosilylation catalyst may be selected from the group consisting of: the above-mentioned (D-1) platinum group metals; (D-2) compounds of such metals, such as chlorinated ginseng (triphenylphosphine) rhodium (I) (Wilkinson's Catalyst), rhodium diphosphine chelates such as [1,2-bis(diphenylphosphino)ethane] dirhodium dichloride or [1,2-bis(diethylphosphino) Phosphino)ethane]dichlorodirhodium, chloroplatinic acid (Speier's Catalyst), chloroplatinic acid hexahydrate, dichloroplatinum; (D-3) compound (D-2) and olefin complexes of functional organopolysiloxanes; (D-4) platinum group metal compounds microencapsulated in a matrix or coreshell (coreshell) type structure; or (D-5) complexes (D-3 ), which are microencapsulated in such matrix or core-shell structures. Complexes of platinum with alkenyl-functional organopolysiloxanes include 1,3-divinyl-1,1,3,3-tetramethyldisiloxane complexes with platinum (Castells Catalysts (Karstedt's Catalyst)) and Pt(0) complexes in tetramethyltetravinylcyclotetrasiloxane (Ashby's Catalyst). Specific examples of suitable platinum-containing catalysts for starting material (D) include chloroplatinic acid (in hexahydrate or anhydrous form) or platinum-containing catalysts obtained by combining chloroplatinic acid with an aliphatically unsaturated organosilicon compound (such as divinyltetramethyldisiloxane) or olefin-platinum-silicon-based complex reactions, as described in Roy's US Patent 6,605,734. Such olefin-platinum-silicon-based complexes can be prepared, for example, by mixing 0.015 moles of (COD)PtCl with _0.045 moles of COD and _0.0612 moles of HMeSiCl, where COD represents cyclooctadienyl and Me represents methyl. Other exemplary hydrosilation catalysts are described in U.S. Patents 2,87,218 to Speier; 3,159,601 to Ashby; 3,60,972 to Lamoreaux; 3,296,291 to Chalk et al; 3,928,629 to Chandra; 3,989,668 to Lee et al; 4,766,176 to Lee et al; 4,784,879 to Lee et al; 5,017,654 to Togashi; Suitable hydrosilylation catalysts for starting material (D) are commercially available, for example, DOWSIL™ 3-8015 Int (Platinum #2), SYL-OFF™ 4000 Catalyst, and SYL-OFF™ 2700 are available from DSC .

The starting material (D) may be one hydrosilylation catalyst or a combination of two or more of the above hydrosilylation catalysts. The amount of (D) hydrosilylation catalyst in the composition will depend on various factors, including the selection of starting materials (A), (B), and (C), and the presence of any optional additional starting materials and the content of the corresponding alkenyl and silicon-bonded hydrogen atoms, and whether a hydrosilylation inhibitor is present in the composition, however, the amount of catalyst is sufficient to catalyze the hydrosilylation reaction of SiH and alkenyl, alternatively the amount of catalyst Sufficient to provide at least 0.01 ppm, alternatively at least 0.05 ppm, alternatively at least 0.1 ppm, alternatively at least 0.5 ppm, and alternatively at least 1 ppm by mass of platinum group metals, starting materials (A), (B), (C), and (D) combination meter. At the same time, the amount of catalyst is sufficient to provide at most 800 ppm, alternatively at most 500 ppm, and alternatively at most 100 ppm by mass of platinum group metals, on the same basis. Alternatively, when (D) the hydrosilylation catalyst comprises platinum complexed with an alkenyl functional organosiloxane, the amount may be 0.01% to 0.02% by weight, based on the combination of starting materials (A) to (D) weighing scale. additional starting material

The hydrosilylation-curable polyorganosiloxane composition may optionally further comprise one or more additional starting materials. For example, additional starting materials may be selected from the group consisting of (E) hydrosilylation inhibitors, (F) adhesion promoters, (G) solvents, and (H) wetting agents, and (E) to ( H) A combination of two or more. (E) Hydrosilation reaction inhibitor

The starting material (E) is a hydrosilylation reaction inhibitor (inhibitor), which can be used to modify the rate of the hydrosilylation reaction, compared to a composition containing the same starting material but omitting the inhibitor. The starting material (E) may be selected from the group consisting of: (E1) acetylenic alcohols, (E2) silylated acetylenic alcohols, (E3) en-yne compounds, (E4) triazoles, (E5) phosphines, (E6) ) thiol, (E7) hydrazine, (E8) amine, (E9) fumarate, (E10) maleate, (E11) ether, (E12) carbon monoxide, (E13) an alkenyl functional siloxane oligomer, and (E14) a combination of two or more thereof. Alternatively, the hydrosilylation inhibitor may be selected from the group consisting of: (E1) acetylenic alcohols, (E2) silylated acetylenic alcohols, (E9) fumarate esters, (E10) maleate esters , (E13) carbon monoxide, (E14) a combination of two or more thereof.

Alkynyl alcohols are exemplified by: 3,5-dimethyl-1-hexyn-3-ol, 1-butyn-3-ol, 1-propyn-3-ol, methylbutynyl (such as 2 -methyl-3-butyn-2-ol and 3-methyl-1-butyn-3-ol), 3-methyl-1-pentyn-3-ol, 3-phenyl-1-but Alkyn-3-ol, 4-ethyl-1-octyn-3-ol, 3,5-dimethyl-1-hexyn-3-ol, and ethynylcyclohexanol (such as 1-ethynyl- 1-cyclohexanol), and combinations thereof. Acetynyl alcohols are known in the art and are commercially available from various sources, see eg US 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 a silylated acetylenic compound reduces the self-silylated Yellowing of reaction products prepared by hydrogenation reactions, such as those described above. Silylated acetylenic compounds are exemplified by: (3-methyl-1-butyne-3-oxy)trimethylsilane, ((1,1-dimethyl-2-propynyl)oxy) Trimethylsilane, bis(3-methyl-1-butyne-3-oxyl)dimethylsilane, bis(3-methyl-1-butyne-3-oxyl)silanemethylvinylsilane , bis((1,1-dimethyl-2-propynyl)oxy) dimethylsilane, methyl (reference (1,1-dimethyl-2-propynyloxy)) silane, Methyl (refer to (3-methyl-1-butyne-3-oxyl)) silane, (3-methyl-1-butyne-3-oxyl) dimethylphenylsilane, (3-methyl Base-1-butyne-3-oxyl)dimethylhexenylsilane, (3-methyl-1-butyne-3-oxyl)triethylsilane, bis(3-methyl-1- butyne-3-oxyl)methyltrifluoropropylsilane, (3,5-dimethyl-1-hexyne-3-oxyl)trimethylsilane, (3-phenyl-1-butyne -3-oxy)diphenylmethylsilane, (3-phenyl-1-butyne-3-oxyl)dimethylphenylsilane, (3-phenyl-1-butyne-3-oxy base) dimethylvinylsilane, (3-phenyl-1-butyne-3-oxyl)dimethylhexenylsilane, (cyclohexyl-1-ethynyl-1-oxyl)dimethylhexylsilane Alkenylsilane, (cyclohexyl-1-ethyn-1-oxyl)dimethylvinylsilane, (cyclohexyl-1-ethynyl-1-oxyl)diphenylmethylsilane, (cyclohexyl-1- Acetylene-1-oxy)trimethylsilane and combinations thereof. The 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. Chlorosilanes react to silylate acetylenic alcohols.

Alternatively, the inhibitor may be an en-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, such as benzotriazole. Alternatively, the inhibitor may comprise a phosphine. Alternatively, the inhibitor may comprise a thiol. Alternatively, the inhibitor may comprise hydrazine. Alternatively, inhibitors may comprise amines. Amino groups are exemplified by tetramethylethylenediamine, 3-dimethylamine-1-propyne, n-methylpropargylamine, propargylamine, 1-ethynylcyclohexylamine, or combinations thereof. Alternatively, the inhibitor may comprise a fumarate. Fumarates include dialkyl fumarates such as diethyl fumarate, dienyl fumarates such as diallyl fumarate, and trans Dialkoxyalkyl butenedioates (such as bis-(methoxymethyl)ethyl fumarate). Alternatively, the inhibitor may comprise maleate. Maleic esters include dialkyl maleates such as diethyl maleate, dienyl maleates such as diallyl maleate, and maleic acid Dialkoxyalkylbutenedioate (such as bis-(methoxymethyl)ethylmaleate). Alternatively, the inhibitor may comprise an ether.

Alternatively, the suppressant may comprise carbon monoxide. Alternatively, the inhibitor may comprise alkenyl functional siloxane oligomers, which may be cyclic or linear, such as methylvinylcyclosiloxane, e.g. 1,3,5,7-tetramethyl-1 ,3,5,7-tetravinylcyclotetrasiloxane, 1,3,5,7-tetramethyl-1,3,5,7-tetrahexenylcyclotetrasiloxane, 1,3- Divinyl-1,3-diphenyl-1,3-dimethyldisiloxane; 1,3-divinyl-1,1,3,3-tetramethyldisiloxane; and A combination of two or more. Compounds useful as such inhibitors are commercially available, eg, from Sigma-Aldrich Inc. or Gelest, Inc., and are known in the art, eg, see US Patent 3,989,667 to Lee, et al. Inhibitors suitable for use herein are exemplified by those described as Stabilizer E in paragraphs [0148] to [0165] of US Patent Application 20007/0099007.

The amount of inhibitor will depend on various factors including the desired pot life, whether the composition is a single composition or multiple compositions, the particular inhibitor used, and the choice and amount of the hydrosilylation catalyst. However, the amount of inhibitor may be 0% to 1%, alternatively 0% to 5%, based on the combined weight of the starting materials (A), (B), (C), and (D) in the composition , alternatively 0.001% to 1%, alternatively 0.01% to 0.5%, and alternatively 0.0025% to 0.025%. (F) Adhesion promoter

The starting material (F) is an adhesion promoter that may optionally be added to the hydrosilylation-curable polyorganosiloxane composition. Suitable adhesion promoters may include transition metal chelates, alkoxysilanes such as alkoxysilanes, combinations of alkoxysilanes and alkyl-functional polyorganosiloxanes, amino-functional silanes, or combinations thereof. Adhesion promoters are known in the art and may comprise silanes having the formula R ³ _r R ⁴ _s Si(OR ⁵ ) _{4-(r + s)} , wherein each R ³ independently has at least 3 carbons A monovalent organic group of atoms; ^R contains at least one SiC-bonded substituent with an adhesion-promoting group, such as an amine, epoxy, mercapto or acrylate group; the subscript r has a value from 0 to 2; The subscript s is 1 or 2; and the sum of (r + s) is not greater than 3. Each R ⁵ is independently a saturated hydrocarbon group. The saturated hydrocarbon group of R ⁵ may be, for example, an alkyl group having 1 to 4 carbon atoms, alternatively 1 to 2 carbon atoms. R ⁵ is exemplified by methyl, ethyl, propyl, and butyl. Alternatively, the adhesion promoter may include partial condensates of the aforementioned silanes. Alternatively, the adhesion promoter may include partial condensates of the aforementioned silanes. Alternatively, the adhesion promoter may comprise a combination of an alkoxysilane and a hydrocarbyl functional polyorganosiloxane.

Alternatively, the adhesion promoter may include unsaturated or epoxy functional compounds. Adhesion promoters may include unsaturated or epoxy functional alkoxysilanes. For example, a functional alkoxysilane may have the formula R ⁶ _t Si(OR ⁷ ) _(4-t) , where the subscript t is 1, 2, or 3, alternatively the subscript t is 1 . Each R ⁶ is independently a monovalent organic group, with the proviso that at least one R ⁶ is an unsaturated organic group or an epoxy-functional organic group. The epoxy-functional organic group of R ⁶ is exemplified by 3-glycidoxypropyl and (epoxycyclohexyl)ethyl. The unsaturated organic group ^of R is composed of 3-methacryloxypropyl, 3-acryloxypropyl, and unsaturated monovalent hydrocarbon groups (such as vinyl, allyl, hexenyl, undecyl alkenyl) for example. Each R ⁷ is independently a saturated hydrocarbon group having 1 to 4 carbon atoms, alternatively 1 to 2 carbon atoms. R ⁷ is exemplified by Me, ethyl, propyl, and butyl.

Examples of suitable epoxy-functional alkoxysilanes include 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, (epoxycyclohexyl)ethyl Dimethoxysilane, (epoxycyclohexyl)ethyldiethoxysilane, and combinations thereof. Examples of suitable unsaturated alkoxysilanes include vinyltrimethoxysilane, allyltrimethoxysilane, allyltriethoxysilane, hexenyltrimethoxysilane, undecenyltrimethoxysilane , 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, 3- Acryloxypropyltriethoxysilane, and combinations thereof.

Alternatively, the adhesion promoter may comprise an epoxy-functional silicone, such as the reaction product of a hydroxyl-terminated polyorganosiloxane with an epoxy-functional alkoxysilane (described above), or a hydroxyl-terminated polyorganosiloxane. A physical blend of organosiloxanes and epoxy functional alkoxysilanes. Adhesion promoters may comprise combinations of epoxy-functional alkoxysilanes and epoxy-functional siloxanes. Examples of adhesion promoters are, for example, 3-glycidoxypropyltrimethoxysilane and the reaction product of hydroxy-terminated methylvinylsiloxane with 3-glycidoxypropyltrimethoxysilane or a mixture of 3-glycidoxypropyltrimethoxysilane and hydroxyl-terminated methylvinylsiloxane, or a mixture of 3-glycidoxypropyltrimethoxysilane and hydroxyl-terminated A mixture of methylvinyl/dimethylsiloxane copolymers.

Alternatively, the adhesion promoter may comprise an amino-functional silane, such as an amino-functional alkoxysilane exemplified by: H ₂ N(CH ₂ ) ₂ Si(OCH ₃ ) ₃ , H ₂ N(CH ₂ ) ₂ Si(OCH ₂ CH ₃ ) ₃ , H ₂ N(CH ₂ ) ₃ Si(OCH ₃ ) ₃ , H ₂ N(CH ₂ ) ₃ Si(OCH ₂ CH ₃ ) ₃ , CH ₃ NH(CH ₂ ) ₃ Si(OCH ₃ ) ₃ , CH ₃ NH(CH ₂ ) ₃ Si(OCH ₂ CH ₃ ) ₃ , CH ₃ NH(CH ₂ ) ₅ Si(OCH ₃ ) ₃ , CH ₃ NH(CH ₂ ) ₅ Si(OCH ₂ CH ₃ ) ₃ , H ₂ N(CH ₂ ) ₂ NH(CH ₂ ) ₃ Si(OCH ₃ ) ₃ , H ₂ N(CH ₂ ) ₂ NH(CH ₂ ) ₃ Si(OCH ₂ CH ₃ ) ₃ , CH ₃ NH(CH ₂ ) ₂ NH(CH ₂ ) ₃ Si(OCH ₃ ) ₃ , CH ₃ NH(CH 2 ) ₂ NH(CH ₂ ) ₃ Si(OCH _{2 CH 3 ) 3} , C ₄ H ₉ NH( CH ₂ ) ₂ NH(CH ₂ ) ₃ Si(OCH ₃ ) ₃ , C ₄ H ₉ NH(CH ₂ ) ₂ NH(CH ₂ ) ₃ Si(OCH ₂ CH ₃ ) ₃ , H ₂ N(CH ₂ ) ₂ SiCH ₃ (OCH ₃ ) ₂ , H ₂ N(CH ₂ ) ₂ SiCH ₃ (OCH ₂ CH ₃ ) ₂ , H ₂ N(CH ₂ ) ₃ SiCH ₃ (OCH ₃ ) ₂ , H ₂ N(CH ₂ ) ₃ SiCH ₃ (OCH ₂ CH ₃ ) ₂ , CH ₃ NH(CH ₂ ) ₃ SiCH ₃ (OCH ₃ ) ₂ , CH ₃ NH(CH ₂ ) ₃ SiCH ₃ (OCH ₂ CH ₃ ) ₂ , CH ₃ NH(CH ₂ ) ₅ SiCH ₃ (OCH ₃ ) ₂ , CH ₃ NH(CH ₂ ) ₅ SiCH ₃ (OCH ₂ CH ₃ ) ₂ , H ₂ N(CH ₂ ) ₂ NH(CH ₂ ) ₃ SiCH ₃ (OCH ₃ ) ₂ , H ₂ N(CH ₂ ) ₂ NH(CH ₂ ) ₃ SiCH ₃ (OCH ₂ CH ₃ ) ₂ , CH ₃ NH(CH ₂ ) ₂ NH(CH ₂ ) ₃ Si CH ₃ (OCH ₃ ) ₂ , CH ₃ NH(CH ₂ ) ₂ NH(CH ₂ ) ₃ SiCH ₃ (OCH ₂ CH ₃ ) ₂ , C ₄ H ₉ NH(CH ₂ ) ₂ NH(CH ₂ ) ₃ SiCH ₃ (OCH ₃ ) ₂ , C ₄ H ₉ NH(CH ₂ ) ₂ NH(CH ₂ ) ₃ SiCH ₃ (OCH ₂ CH ₃ ) ₂ , and combinations thereof.

Alternatively, the adhesion promoter may comprise a transition metal chelate. Suitable transition metal chelates include titanates, zirconates such as zirconium acetylacetonate, aluminum chelates such as aluminum acetylacetonate, and combinations thereof. Alternatively, the adhesion promoter may comprise a combination of a transition metal chelate and an alkoxysilane, such as glycidoxypropyltrimethoxysilane in combination with an aluminum chelate or a zirconium chelate.

The amount of adhesion promoter depends on various factors, including the type of adhesion promoter selected and the end use of the composition and its cured product. However, based on the combined amount of starting materials (A), (B), (C), and (D), the amount of adhesion promoter can be > 0 to < 2%. (G) solvent

Starting material (G) is a solvent that may optionally be added to facilitate combination of one or more starting materials. For example, (B) alkenyl-functional polyorganosilicate resin and/or (D) hydrosilylation catalyst can be delivered in a solvent. The solvent may include hydrocarbons, halogenated hydrocarbons, or cyclic siloxanes (with an average degree of polymerization of 3 to 10), and/or halogenated hydrocarbons. Suitable hydrocarbons may be i) aromatic hydrocarbons, such as benzene, toluene, ethylbenzene, or xylene; ii) aliphatic hydrocarbons, such as hexane, heptane, octane, or iso-paraffin; or combination. Suitable halogenated hydrocarbons include trichloroethylene; perchloroethylene; trifluoromethylbenzene; 1,3-bis(trifluoromethyl)benzene; methylpentafluorobenzene; dichloromethane; - trichloroethane; and methylene chloride. Suitable cyclic siloxanes having a degree of polymerization of 3 to 10, alternatively 3 to 6 include hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, and/or decamethylcyclopentasiloxane . The exact amount of solvent can vary depending on the type and amount of starting materials to be combined and the type of solvent chosen, however, the amount of solvent can be chosen so that the composition forms a homogeneous mixture. The amount of solvent may be > 0% to < 100%, alternatively 10% to 90%, alternatively 5% based on the combined weight of the starting materials (A), (B), (C), and (D) to 80%. After preparing the composition, all or part of the solvent may optionally be removed. (H) Wetting agent

The hydrosilylation-curable polyorganosiloxane composition may optionally further comprise a wetting agent, which is a surface-active molecule that reduces the surface tension of the composition and facilitates adhesion of the composition in the mold or substrate. Uniform distribution to help fill gaps and/or form a uniform polysiloxane encapsulation film after curing. The humectant may be a non-functional polydiorganosiloxane, such as bis-trimethylsiloxy terminated polydimethylsiloxane, having a viscosity of 5 to 100 cP. Such wetting agents are known in the art and are commercially available, for example under the trade name DOWSIL™ 200 Fluids from DSC. The amount of wetting agent may be from 0 to 1% based on the combined weight of the starting materials (A), (B), (C), and (D).

The hydrosilylation-curable polyorganosiloxane composition may contain no filler or only a limited amount of filler, such as 0 to 30% by weight, based on the combined weight of all starting materials in the composition. Without wishing to be bound by theory, it is believed that fillers may agglomerate or otherwise adhere to the equipment used to apply or dispense the composition, and if optical clarity is desired, the filler may interfere with the composition and the polysiloxane formed therewith. Optical properties of oxygen-sealed films, such as transparency. Fillers may also be detrimental to the adhesion of the silicone encapsulation film to the substrate. method of making the composition

The above compositions can be prepared by any convenient means, such as mixing the starting materials at RT using conventional equipment such as stirred vessels or static mixers. When an inhibitor is used, the inhibitor can be added prior to the hydrosilylation catalyst, for example when the composition is prepared at elevated temperature and/or the composition is prepared as a single composition. For example, one or more starting materials, such as (B) polyorganosilicate resin and (D) hydrosilylation catalyst, can be delivered in a solvent when combined with one or more other starting materials in the composition. After mixing the starting materials, all or part of the solvent can be removed under conditions that do not cure the composition (eg, by reducing pressure or heating at a temperature sufficient to volatilize the solvent but not sufficient to cure the composition). Those of ordinary skill in the art will appreciate that the resulting composition is solvent-free or may contain traces of residual solvent from delivery of the starting materials, however, solvents (e.g., organic solvents such as toluene or non-functional polymers Diorganosiloxane) is added to the composition.

Alternatively, the composition may be prepared in multiple compositions, for example when the composition is to be stored for a long period of time before use, for example up to 6 hours before being dispensed onto a substrate or into a mold. In multiple compositions, the hydrosilylation catalyst is stored in a separate portion from any starting material having silicon-bonded hydrogen atoms (e.g., polyorganohydrogensiloxane) and assembled shortly before the composition is used The fractions (eg, by mixing at RT).

For example, multiple compositions may be prepared by combining starting materials comprising at least some of the following: (A) alkenyl-functional polydiorganic Silicone polymer, (C) polyorganohydrogensiloxane, and optionally one or more of the other additional starting materials described above. Curing agents may be prepared by combining starting materials comprising at least some of the following: (A) alkenyl-functional polydiorganosiloxane polymers, (D ) a hydrosilylation catalyst, and optionally one or more of the other additional starting materials described above. Starting materials can be combined at RT or at elevated temperature. A hydrosilylation inhibitor may be included in one or more of the substrate portion, the curing agent portion, or a separate additional portion. Adhesion promoters may be added to the base portion, or may be added as a separate extra portion. The starting material (B), an alkenyl functional polyorganosilicate resin, may be added to the base part or a separate additional part. When a two-part composition is used, the weight ratio of the amount of substrate part to curing agent part may range from 1:1 to 10:1. The composition will be cured through a hydrosilylation reaction to form a polysiloxane encapsulation film.

When a solvent is present, the method may optionally further comprise removing all or part of the solvent prior to and/or during curing. Removal of the solvent may be performed by any convenient means, such as heating at a temperature that will volatilize the solvent without fully curing the composition (e.g., at 70°C to 120°C, alternatively 50°C to 100°C, and alternatively 70° C. to 80° C.) for a period of time sufficient to remove all or part of the solvent (eg, 30 seconds to 1 hour, alternatively 1 minute to 5 minutes).

The pressure-sensitive adhesive composition may be cured by heating at a temperature of 80°C to 200°C, alternatively 90°C to 180°C, alternatively 100°C to 160°C, and alternatively 110°C to 150°C (eg, 30 seconds to one hour, alternatively 1 to 5 minutes) to cure the composition. If the cure rate needs to be increased or the process temperature decreased, the catalyst level can be increased and/or the inhibitor level can be decreased. This forms cured silicone. Curing can be performed by placing the composition (eg, in a mold or as a film coated on a substrate) in an oven. The amount of the composition depends on the particular application, however, the amount may be sufficient such that the thickness of the resulting cured polysiloxane after curing may be from 5 microns to 50 microns, and for protective films from 6 microns to 50 microns. microns, alternatively 8 microns to 40 microns, and alternatively 10 to 30 microns. Method for producing polysiloxane encapsulation film

The composition prepared as described above can be used in a method of forming a polysiloxane encapsulating film. This method contains: (1) A film-forming, hydrosilylation-curable polyorganosiloxane composition comprising (A) a polydiorganosiloxane polymer; (B) an alkenyl-functional polyorganosilicate resin; (C) Polyorganohydrogensiloxane; and (D) a hydrosilylation reaction catalyst, wherein the starting materials (A), (B), (C), and (D) and the method for preparing the composition are as described above; and (2) Curing the hydrosilation curable polyorganosiloxane composition to form a polysiloxane encapsulation film. Step (1) can be performed by any convenient means such as molding, for example, dispensing the hydrosilylation-curable polyorganosiloxane composition into a mold such as a steel frame, or printing on a substrate (such as , inkjet printing) hydrosilation curable polyorganosiloxane composition. After curing in step (2), an amount of hydrosilylation curable composition sufficient to provide a silicone encapsulating film having a thickness of up to 50 microns, alternatively 1 to 50 microns, may be used. Step (2) can be performed by heating at a temperature of 80° C. to 150° C. for 15 minutes to 1 hour, for example, by placing in an oven. Optionally, increased pressure may be applied in step (2). Method of using polysiloxane encapsulation film

The polysiloxane encapsulation film prepared as described above is suitable for use in OLED displays, for example to cover moisture-sensitive electronic components in OLED displays. For example, one method involves covering moisture-sensitive electronic components in an OLED display with the hydrosilylation-curable composition described above, and curing the composition to produce a polysiloxane encapsulation film, as described above.

Figure 1 shows a structural diagram for an assembly (100) of a transparent and rigid OLED with a glass substrate. The component (100) includes a dam (101) containing a color filter (102), a passivation layer (105), and a thin film transistor and white organic light emitting diode (104). The polysiloxane encapsulation film (103) prepared as described above surrounds the color filter (102), passivation layer (105), and thin film transistor and white organic light emitting diode (104), thereby protecting them from moisture and other damages. The assembly (100) is mounted to a glass substrate (106). example

These examples are intended to explain the present invention in more detail to those skilled in the art, but are not intended to limit the scope of the present invention presented in the appended claims. The starting materials used in these examples are described in Table 1 below. Table 1 - Starting Materials name structure source DOWSIL™ 6-3444 Int 62% to 75% polymethyl silicate resin, which has 1.935% solubility in xylene (6% to 32%), toluene (0.09% to 0.13%) and ethylbenzene (6% to 8% ) vinyl in BTEX solvent mixture. The solvent was then removed such that the amounts in Table 2 below represent resin solids. DSC DOWSIL™ 6-3570 Polymer Trimethylsiloxy-terminated poly(dimethyl/methylhydrogen)siloxane with a silicon-bonded hydrogen content of 0.776% DSC DOWSIL™ 1-687 2,4,6,8-Tetramethyl-2,4,6,8-tetravinylcyclotetrasiloxane, D ^Vi ₄ DSC Polymer 1 Bis-dimethylvinylsiloxy terminated polydimethylsiloxane having the unit formula M ^Vi D ₂₉₀ M ^Vi DSC DOWSIL™ 3-8015 Int (Platinum #2) Platinum, 1,3-diphenyl-1,1,3,3-tetramethyldisiloxane complex, dimethylvinylsiloxy-terminated dimethylsiloxane, and tetramethyldisiloxane Divinyldisiloxane mixture DSC

A hydrosilylation-curable polyorganosiloxane composition (sample) was prepared as follows. The starting materials as described in Table 1 were weighed in the amount (parts by weight) shown in Table 2 below into a container and mixed using a Thinky mixer at 1500 rpm for 2 minutes. Table 2. Hydrosilylation-curable polyorganosiloxane composition in weight % Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Example 8 6-3444 41.52 42.29 42.69 42.86 42.96 43.12 43.33 43.46 Polymer 1 52.84 53.82 54.34 54.54 54.67 54.88 55.15 55.31 6-3570 5.45 3.75 2.86 2.5 2.28 1.92 1.46 1.18 1-687 0.18 0.13 0.1 0.08 0.08 0.06 0.05 0.04 3-8015 0.013 0.013 0.01 0.01 0.01 0.01 0.014 0.014 total 100 100 100 100 100 100 100 100 SiH/Vi ratio 1.15 0.8 0.59 0.53 0.49 0.41 0.31 0.25

In Table 2, Example 1, Example 2, Example 3, and Example 8 are comparative. Example 1, Example 2, and Example 3 each had a polyorganohydrogensiloxane content > 2.5% and a SiH/Vi ratio > 0.55. Example 8 has a polyorganohydrogensiloxane content < 1.4% and a SiH/Vi ratio < 0.30.

To prepare silicone encapsulating films, 15 mL of each sample described in Table 2 was poured into a steel frame and pressed at 100° C. for 30 minutes using a hydraulic hot press. The resulting film has a thickness of 1.8 to 2 mm.

The modulus of each membrane was measured at RT using a Modulus Compact Rheometer (MCR, Anton Paar). The dielectric constant was measured by placing each film between two 38 mm diameter stainless steel electrodes of an impedance instrument (16451B dielectric text fixture, Keysight). A frequency of 100 kHz and a voltage of 1 V were applied at RT.

Hardness was measured using a Hildebrand hardness tester (Shore 00), Asker CLE-150LJ (Shore A). Test samples were prepared in 8 mm films and assembled with the instrument. Press the weight and measure the hardness value. The results are shown in Table 3 below. Table 3. Results unit/condition Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Storage modulus (G) MPa 3.08 1.48 1.07 0.78 0.25 0.14 0.06 Dielectric constant (Dk) 100kHz, RT 3.9 2.87 2.88 2.77 2.78 2.769 2.62 Hardness value Shaw A, 00 45.19 (A) 26.84 (A) 16.04 (A) 12 (A) 40.88 (00) 37.88 (00) not applicable (NA)

The data in Table 3 show that the content of cyclic siloxane (eg, DOWSIL™ 1-687) has a negligible effect on the properties of the cured film. Examples 1, 2, and 3 show that when the SiH/Vi ratio and polyorganohydrogensiloxane content of the composition are higher than those described in claim 1, the dielectric constant and modulus are too high. Example 8, which contained less polyorganohydrogensiloxane (crosslinker) than described in claim 1 below, was cured to form a gel state rather than a rigid film such that the Dk could not be measured. Examples 4 to 7 show that polysiloxane encapsulation films with hardness, dielectric constant, and storage modulus suitable for OLED displays can be prepared under the tested conditions. The curable polyorganosiloxane composition may be cured to form a polysiloxane encapsulating film, wherein 0.5≦G≦1 at RT; Dk<2.8, and a Shore A hardness of at least 12, alternatively 12 to 45. Industrial utilization

A silicone encapsulating film is prepared by curing a hydrosilylation curable polyorganosiloxane composition as described herein. The hydrosilylation curable composition can provide a polysiloxane encapsulating film having a storage modulus G, wherein the value is 0.05 MPa < G < 1 MPa at RT. Without wishing to be bound by theory, it is believed that a modulus in the above range will provide a silicone encapsulation film with a Dk < 2.8. Furthermore, without wishing to be bound by theory, it is believed that if the modulus is below 0.05 MPa, the polysiloxane encapsulating film may have insufficient rigidity or have a gel state, and the viscosity may increase to undesired levels, however, if the modulus If it is greater than 1 MPA, then Dk can be > 2.8. Definition and Usage of Terms

All amounts, concentrations, ratios, and percentages are by weight unless otherwise indicated. The Summary and Abstract of the Invention are incorporated herein by reference. The articles "a (a/an)" and "the" each mean one or more unless otherwise specified. The singular includes the plural unless otherwise specified. Abbreviations are defined in Table 4 below. Table 4. Abbreviations abbreviation definition ℃ Celsius CF color filter D. Difunctional siloxane units of formula (Me ₂ SiO _2/2 ) D ^Vi Difunctional siloxane unit of formula (MeViSiO _2/2 ) d Dielectric constant DSC Dow Silicones Corporation of Midland, Michigan, USA G storage modulus kHz kilohertz m Monofunctional siloxane units of the formula (Me ₃ SiO _1/2 ) M ^Vi Monofunctional siloxane units of the formula (Me ₂ ViSiO _1/2 ) Me methyl min minute mL or ml ml mm mm MPa MPa OLED organic light emitting diode RPM or rpm revolutions per minute RT Room temperature at 7 ± 2°C TFT TFT V volt Vi vinyl WOLED White Organic Light Emitting Diodes

100: components 101: Dam body 102: Color filter 103: Polysiloxane encapsulation film 104: Thin film transistor and white organic light emitting diode 105: Passivation layer 106: Glass substrate

[FIG. 1] is a structure scheme of a transparent and rigid OLED mounted to a glass substrate.

100: components

101: Dam body

102: Color filter

103: Polysiloxane encapsulation film

104: Thin film transistor and white organic light emitting diode

105: Passivation layer

106: Glass substrate

Claims (10)

A method for forming a polysiloxane encapsulation film, the method comprising: (1) forming a hydrosilylation curable composition into a film, wherein the composition comprises: starting materials (A), (B), ( Based on the combined weight of C), and (D), 50% to 58.59% of (A) polydiorganosiloxane polymer having the unit formula (R ¹ ₂ R ² SiO _1/2 ) _a (R ¹ ₂ SiO _2/2 ) _b , wherein R ¹ is an alkyl group having 1 to 12 carbon atoms, R ² is an alkenyl group having 2 to 12 carbon atoms, and the subscripts a, b, and c represent units per molecule and have the following values: a = 2, and 100 ≤ b ≤ 300; and based on the combined weight of starting materials (A), (B), (C), and (D), 40% to 48.59 % of (B) alkenyl functional polyorganosilicate resin having the unit formula (R ¹ ₂ R ² SiO _1/2 ) _d (R ¹ ₃ SiO _2/2 ) _e (SiO _4/2 ) _f (HO _1/2 ) _g , wherein R ¹ and R ² are as described above, subscripts e, f, g, and h represent the mole fraction of each unit in the resin, and have the following values: d > 0, e ≥ 0 , f > 0, the amount (d + e + f) = 1, and the resin has a number average molecular weight of 1,500 g/mol to 15,000 g/mol, and the subscript g > 0, provided that the subscript g has enough Values are provided for the resin having a hydroxyl content of 0 to 2% by weight based on the weight of the resin; 1.4% to 2.5% by weight of (C) polyorganic Hydrogensiloxanes having the unit formula (R ¹ ₂ HSiO _1/2 ) _h (R ¹ ₃ SiO _1/2 ) _i (R ¹ ₂ SiO _2/2 ) _j (R ¹ HSiO _2/2 ) _k , wherein R ¹ As mentioned above, the subscripts h, i, j, and k represent the average number of units per molecule, 0 ≤ h ≤ 2, 0 ≤ i ≤ 2, (h + i) = 2, 0 ≤ j < 10 , 0 < k < 10, 0 < (j + k) < 10, and 3 ≤ (h + k) ≤ 12; wherein (A) the polydiorganosiloxane polymer, (B) the alkenyl functional polymer The organosilicate resin, and (C) the polyorganohydrogensiloxane in an amount sufficient to provide a weight ratio of silicon-bonded hydrogen atoms from (C) relative to alkenyl groups from (A) and (B) combined ( SiH/Vi ratio) from 0.30 to 0.55; and from 0.01% to 0.02% by weight, based on the combined weight of the starting materials (A) to (D), of (D) a hydrosilylation catalyst comprising an alkenyl functional organic Silicone-complexed platinum to form hydrosilylation-curable polyorganosiloxane compositions; and (2) solid The hydrosilylation curable polyorganosiloxane composition is oxidized to form the polysiloxane encapsulation film. The method of claim 1, wherein each R ¹ is methyl and each R ² is vinyl. The method of claim 1 of claim 2, wherein the hydrosilylation curable polyorganosiloxane composition further comprises an additional starting material selected from the group consisting of (E) hydrosilylation A reaction inhibitor, (F) adhesion promoter, (G) wetting agent, and a combination of two or more of (E) to (G). The method of any one of claims 1 to 3, wherein the method further comprises combining the starting materials by mixing at ambient temperature and pressure to form the hydrosilylation curable polyorganosiloxane composition. The method according to any one of claims 1 to 4, wherein the forming in step (1) is by applying the hydrosilylation curable polysilane in an amount sufficient to provide the polysiloxane encapsulation film with a thickness of 1 mm to 5 mm The polyorganosiloxane composition is poured into a mold. The method according to any one of claims 1 to 5, wherein the curing in step (2) is carried out by heating at a temperature of 80° C. to 150° C. for 15 minutes to 1 hour. A use of the polysiloxane encapsulation film according to any one of claims 1 to 6 for covering moisture-sensitive electronic components in OLED displays. A method comprising covering moisture-sensitive electronic components in an OLED display with a polysiloxane encapsulation film prepared by the method according to any one of claims 1 to 6. A component of an OLED display, wherein the component comprises: a dam (dam) (101), wherein the dam (101) accommodates a color filter (102), a passivation layer (105), and a thin film transistor and A white organic light emitting diode (104), and the color filter (102), the passivation layer (105) is surrounded by a polysiloxane encapsulation film (103) prepared according to any one of claims 1 to 6 ), and the thin film transistor and white organic light emitting diode (104), so as to protect them from moisture and other damages. In a method of making an OLED display, improving comprises: (1) covering an electronic component of the OLED display with a hydrosilylation curable composition, and (2) curing the hydrosilylation curable composition to form a protective electronic component A polysiloxane encapsulating film; wherein the hydrosilylation reaction curable composition comprises: Based on the combined weight of the starting materials (A), (B), (C), and (D), 50% to 58.59% of (A) Polydiorganosiloxane polymers having the unit formula (R ¹ ₂ R ² SiO _1/2 ) _a (R ¹ ₂ SiO _2/2 ) _b , wherein R ¹ is An alkyl group, R ² is an alkenyl group with 2 to 12 carbon atoms, the subscripts a, b, and c represent the average number of units per molecule, and have the following values: a = 2, and 100 ≤ b ≤ 300; and based on the combined weight of the starting materials (A), (B), (C), and (D), 40% to 48.59% of (B) an alkenyl-functional polyorganosilicate resin having units Formula (R ¹ ₂ R ² SiO _1/2 ) _d (R ¹ ₃ SiO _2/2 ) _e (SiO _4/2 ) _f (HO _1/2 ) _g , wherein R ¹ and R ² are as above, subscript e, f, g, and h represent the mole fraction of each unit in the resin, and have the following values: d＞0, e≥0, f＞0, amount (d+e+f)=1, and the The resin has a number average molecular weight of 1,500 g/mol to 15,000 g/mol, and the subscript g > 0, with the proviso that the subscript g has sufficient to provide the resin with a hydroxyl content of 0 to 2% by weight, based on the weight of the resin 1.4% to 2.5% by weight of (C) polyorganohydrogensiloxane having the unit formula (R ¹ ₂ HSiO _1/2 ) based on the combined weight of the starting materials (A) to (D) _h (R ¹ ₃ SiO _1/2 ) _i (R ¹ ₂ SiO _2/2 ) _j (R ¹ HSiO _2/2 ) _k , wherein R ¹ is as described above, and the subscripts h, i, j, and k represent each The average number of units of the molecule, 0 ≤ h ≤ 2, 0 ≤ i ≤ 2, (h + i) = 2, 0 ≤ j < 10, 0 < k < 10, 0 < (j + k) < 10, and 2 ≤ (h + k) ≤ 12; wherein (A) the polydiorganosiloxane polymer, (B) the alkenyl functional polyorganosilicate resin, and (C) the polyorganohydrogensiloxane an amount sufficient to provide a weight ratio (SiH/Vi ratio) of silicon-bonded hydrogen atoms from (C) relative to alkenyl groups from (A) and (B) combined from 0.30 to 0.55; and starting material (A) To the combined weight of (D), 0.01% by weight to 0.01% by weight. 02% by weight of (D) a hydrosilylation catalyst comprising platinum complexed to an alkenyl functional organosiloxane.

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