Radiation curable polyorganosiloxane resin-linear copolymer compositions and methods of making and using the same

Abstract

Radiation curable polyorganosiloxane resin-linear copolymer compositions include (A) an alkenyl, aryl functional resin linear polyorganosiloxane block copolymer, (B) a mercapto functional crosslinker, and (C) a photoradical initiator. The compositions can also include (D) a stabilizer, (E) an adhesion promoter, or both. The compositions can be used to encapsulate (opto)electronic devices, such as light emitting diodes.

Description

Cross-reference to related applications

[0001] This application claims the benefit of U.S. Provisional Patent Application Serial No. 63 / 567485, filed March 20, 2024, pursuant to 35 USC §119(e). U.S. Provisional Patent Application Serial No. 63 / 567485 is incorporated herein by reference. Technical Field

[0002] This invention relates to radiation-curable polyorganosiloxane resin-linear copolymer compositions and methods for preparing and using the compositions. More specifically, the compositions can be used in low-temperature processes to encapsulate (opto)electronic devices such as miniature LED arrays and micro-LED arrays. Background Technology

[0003] The market for miniature and micro-sized light-emitting diodes (LEDs) is growing rapidly, partly due to their use in displays and automotive applications. Miniature LED arrays are used as backlight panels for standard LCD displays, improving brightness, contrast, and black levels. Micro-sized LEDs refer to tiny LEDs used directly as pixels in a display, specifically combinations of red, green, and blue LED dots. Both technologies require sealants to protect the fragile LEDs and improve light extraction by replacing air with silicone interlayers.

[0004] Historically, encapsulation compositions have been applied to LED components via liquid injection molding. Recently, hot melt systems have become more popular due to their advantages over liquid injection molding systems. These advantages include ease of covering large areas, simplified processing (because no dam is needed to prevent overflow), and increased productivity and reprocessability.

[0005] However, some hot melt film technologies employing hydrosilanization curing may require high temperatures (≥80°C) for a thermal triggering mechanism to make the material flowable, and after activation of the platinum catalyst by UV irradiation, the material may require even higher temperatures (100°C) and longer curing times (typically ≥1 hour). Unfortunately, some display designs incorporate temperature-sensitive materials that cannot be exposed to high temperatures for extended periods without compromising their functionality. Therefore, to protect temperature-sensitive materials and improve manufacturing efficiency to meet the growing demand for (opto)electronic devices such as miniature and micro-LED devices, there is an industrial need to identify an encapsulation technology that does not require the temperature or time of a hydrosilanization curing system. Summary of the Invention

[0006] The radiation-curable polyorganosiloxane resin-linear copolymer composition comprises: (A) an alkenyl, aryl-functionalized polyorganosiloxane resin-linear block copolymer; (B) an organic thiol-functionalized crosslinking agent; and (C) a photoinitiator. Methods for preparing and using the composition for encapsulation are provided. Encapsulated articles can be prepared from this composition. Attached Figure Description

[0007] Figure 1 An exemplary encapsulation process using a radiation-curable polyorganosiloxane resin-linear copolymer composition (the composition) is described. In step 1), the composition (in the form of a solid film, 101) is placed on a substrate 102 having features (such as LEDs) on its surface. In step 2), the composition 101 is formed on at least a portion of the substrate 102 while the composition 101 is made flowable by heating (optionally by vacuum lamination), thereby encapsulating the features. In step 3), the composition 101 is cured by a technique including exposure to ultraviolet radiation to form an encapsulant 103 on the substrate 102. Detailed Implementation

[0008] The radiation-curable polyorganosiloxane resin-linear copolymer composition (the composition) described above comprises: (A) an alkenyl or aryl functional polyorganosiloxane resin-linear block copolymer; (B) an organic thiol functional crosslinking agent; and (C) a photoinitiator. The composition may also optionally contain additional starting materials selected from the group consisting of: (D) stabilizers, (E) adhesion promoters, (F) solvents, and combinations of two or more of these.

[0009] (A) Alkenyl and aryl functionalized polyorganosiloxane resins-linear block copolymers

[0010] The alkenyl and aryl functional resin-linear polyorganosiloxane block copolymers described above comprise linear and nonlinear blocks. Each linear block contains 10 to 500 units of the formula (R... 2 R 3 SiO 2 / 2 The dimethylsilyloxy unit of ) wherein each R 2 and each R 3The nonlinear block is a monovalent hydrocarbon group of 1 to 30 carbon atoms, chosen independently. Each nonlinear block has a molecular weight of at least 500 g / mol. The nonlinear block contains a trimethylsiloxy unit and a hydrolyzable group; and the nonlinear block also contains an alkenyl group and an aryl group bonded to a silicon atom. At least 30 mol% of the nonlinear blocks can be crosslinked with each other, and each linear block is connected to at least one nonlinear block. The copolymer can have a molecular weight (Mw) of at least 20,000 g / mol as measured by GPC according to the following test method. Samples for GPC analysis are prepared at a concentration of 1% in qualified ACS grade toluene, filtered through a 0.45 μm PTFE syringe filter, and analyzed relative to polystyrene standards. The relative calibration (3rd order fit) for molecular weight determination is based on 12 polystyrene standards with molecular weights ranging from 580 Daltons to 906,600 Daltons. The chromatographic equipment used was a Viscotek GPC Max equipped with a vacuum degasser, a Viscotek VE3580 RI detector, and two (300 mm × 7.5 mm) Polymer Laboratories Mixed C columns (molecular weight separation range 200 to 3,000,000) with guard columns. Separation was performed using qualified-grade THF flowing at 1.0 mL / min, with an injection volume of 100 μL and the column and detector heated to 35 °C. Data collection lasted 45 minutes. Malvern OMNISEC 5.02 was used for data collection, and Malvern OMNISEC 5.12 was used for data reduction. Routine molecular weight calibration was performed using a total of 17 narrow molecular weight PS linear standards from Agilent with Mp values ​​ranging from 4,000 kg / mol to 0.58 kg / mol. Calibration curve fitting was performed using a third-order polynomial. Therefore, all molecular weight averages, distributions, and molecular weight references provided in this report are PS equivalents, and only RI values ​​were used for molecular weight calculations.

[0011] "Linear" polyorganosiloxanes typically contain primarily D units, resulting in polydiorganosiloxanes that function as fluids with varying viscosities, depending on the DP indicated by the number of D units in the polydiorganosiloxane. Linear polydiorganosiloxanes typically have a Tg below 25°C, alternatively below 0°C, and alternatively below -20°C.

[0012] When the majority of silanoxy units are T, Q, or both, a "resin" polysiloxane is obtained. When T silanoxy units are dominant, the resulting polysiloxane can be called a "sesquioxane resin." When Q units are dominant, the resulting polysiloxane can be called a silicate. Increasing the amount of T and / or Q silanoxy units (relative to the amount of M and / or D units) generally results in the polysiloxane having increased hardness and / or glass-like properties. Therefore, "resin" polysiloxanes have higher Tg values ​​than linear polydiorganosiloxanes; for example, resin polysiloxanes typically have Tg values ​​greater than 30°C, alternatively greater than 40°C, and alternatively greater than 50°C. Alternatively, up to 100°C, alternatively up to 80°C, alternatively up to 70°C, and alternatively from 50°C to 100°C.

[0013] As used herein, “resin-linear polyorganosiloxane block copolymer” refers to a polyorganosiloxane containing polydiorganosiloxane blocks, comprising, alternatively substantially consisting of, or alternatively consisting of: a combination of D units and resin blocks containing T units. Resin-linear polyorganosiloxane block copolymers are block copolymers (not random copolymers). The D units are bonded together to form polymeric polydiorganosiloxane chains having 10 to 500 D units, referred to herein as linear blocks. The T units are primarily bonded to each other to form branched polymer chains, and these are included in the nonlinear blocks. When alkenyl or aryl functional resin-linear polyorganosiloxane block copolymers are provided in solid form, a large number of these nonlinear blocks can aggregate to form “nanodomains.” The formula (R...) arranged in linear blocks... 2 R 3 SiO 2 / 2 Each linear block of the dimethoxyloxy unit has an average of 10 to 500 formulas (R). 2 R 3 SiO 2 / 2 The linear block may have an average of at least 10, alternatively at least 50, alternatively at least 100, alternatively at least 150, and alternatively at least 200 dimethoxy units; while each linear block may have at most 500, alternatively at most 400, alternatively at most 300, and alternatively at most 200 dimethoxy units. Alternatively, each linear block may have 100 to 150 dimethoxy units, alternatively 115 to 125 dimethoxy units, and alternatively 90 to 170 dimethoxy units. The linear block is covalently bonded to the nonlinear block.

[0014] The trimethylsiloxy units are arranged in nonlinear blocks. Each nonlinear block has a molecular weight of at least 500 g / mol, alternatively from 500 g / mol to 4,000 g / mol. Alternatively, each nonlinear block may have at least 500 g / mol, alternatively at least 1,000 g / mol, alternatively at least 1,500 g / mol of Mn; while each nonlinear block may have at most 4,000 g / mol, alternatively at most 3,000 g / mol of Mn; alternatively at most 2,500 g / mol; alternatively at most 2,000 g / mol; and alternatively at most 1,500 g / mol.

[0015] Alkenyl and aryl functional resins-linear polyorganosiloxane block copolymers may also contain hydrolyzable groups located in the nonlinear blocks. The hydrolyzable groups may have the formula (ZO... 1 / 2 Each Z is independently selected from H or a monovalent hydrocarbon group having 1 to 30 carbon atoms. Alternatively, the monovalent hydrocarbon group of Z can be an alkyl group, such as an alkyl group having 1 to 6 carbon atoms, alternatively 1 to 4 carbon atoms, alternatively 1 to 2 carbon atoms, and alternatively methyl. Alternatively, each Z can be H. The alkenyl, aryl functional resin-linear polyorganosiloxane block copolymer may contain up to 50 mol% of hydrolyzable groups, alternatively at least 0.5 mol%, alternatively at least 1 mol%, alternatively at least 5 mol%, alternatively at least 10 mol%, and alternatively at least 15 mol%; while the alkenyl, aryl functional resin-linear polyorganosiloxane block copolymer may contain up to 50 mol%, alternatively at least 35 mol%, alternatively at least 30 mol%, alternatively at least 25 mol%, and alternatively at least 20 mol% of hydrolyzable groups.

[0016] Hydrolyzable groups allow for further reaction, curing, or crosslinking of alkenyl, aryl functional resin-linear polyorganosiloxane block copolymers. Crosslinking of nonlinear blocks can be achieved through various chemical mechanisms and / or partially. For example, crosslinking of nonlinear blocks within alkenyl, aryl functional resin-linear polyorganosiloxane block copolymers can result from the condensation of residual silanols and / or alkoxy groups present in the nonlinear blocks. At least 30% of the nonlinear blocks in the alkenyl, aryl functional resin-linear polyorganosiloxane block copolymers can be crosslinked with each other, alternatively at least 40%, alternatively at least 50%, alternatively at least 60%, alternatively at least 70%, and alternatively at least 80% can be crosslinked with each other. Alternatively, 30% to 80% of the nonlinear blocks may cross-link with each other, and alternatively 30% to 70%, alternatively 30% to 60%, alternatively 30% to 40%, and alternatively 30% to 40% of the nonlinear blocks may cross-link with each other.

[0017] The alkenyl and aryl functional resin-linear polyorganosiloxane block copolymer can have a Mw of 20,000 g / mol to 500,000 g / mol. Alternatively, the alkenyl and aryl functional resin-linear polyorganosiloxane block copolymer can have a Mw of at least 20,000 g / mol, alternatively at least 40,000 g / mol, alternatively at least 50,000 g / mol, alternatively at least 60,000 g / mol, alternatively at least 70,000 g / mol, and alternatively at least 80,000 g / mol; while the Mw can be at most 500,000 g / mol. 0 g / mol, alternatively up to 450,000 g / mol, alternatively up to 400,000 g / mol, alternatively up to 350,000 g / mol, alternatively up to 300,000 g / mol; alternatively up to 250,000 g / mol; alternatively up to 200,000 g / mol; alternatively up to 150,000 g / mol and alternatively up to 100,000 g / mol. Alternatively, the alkenyl, aryl functional resin-linear polyorganosiloxane block copolymer may have Mn from 15,000 g / mol to 50,000 g / mol. Alternatively, the alkenyl, aryl functional resin-linear polyorganosiloxane block copolymer may have a Mw of 25,000 g / mol to 400,000 g / mol, alternatively 30,000 g / mol to 300,000 g / mol, alternatively 35,000 g / mol to 200,000 g / mol, alternatively 40,000 g / mol to 100,000 g / mol, alternatively 45,000 g / mol to 75,000 g / mol, and alternatively 49,000 g / mol to 74,000 g / mol. Alternatively, the alkenyl or aryl functional resin-linear polyorganosiloxane block copolymer may have a Mn content of at least 15,000 g / mol, or alternatively at least 20,000 g / mol; while the Mn content may be at most 50,000 g / mol, or alternatively at most 30,000 g / mol, or alternatively at most 25,000 g / mol. Mw and Mn can be measured by GPC using the test methods provided above.

[0018] Alkenyl, aryl functional resin-linear polyorganosiloxane block copolymers can be separated into solids, for example, by casting a film of the copolymer in an organic solvent (e.g., benzene, toluene, xylene, or combinations thereof) and evaporating the solvent. The alkenyl, aryl functional resin-linear polyorganosiloxane block copolymer can be provided in solution in an amount of 50% to 80%, alternatively 60% to 80%, of the copolymer solids in the organic solvent, with the remainder being the organic solvent in solution. The solution can be cast as a film and then dried to remove the solvent and form a solid, and the nonlinear blocks can be further aggregated together to form nanodomains. As used herein, “major aggregation” means that the majority of the nonlinear blocks are present in certain regions of the solid composition (referred to herein as “nanodomains”). A nanodomain refers to a phase-separated phase region within a solid alkenyl or aryl functional resin-linear polyorganosiloxane block copolymer, having at least one dimension with a size of 1 nm to 100 nm. The nanodomain can vary in shape, provided that at least one dimension of the nanodomain has a size of 1 nm to 100 nm. The nanodomain can be regular or irregular in shape, alternatively earth-shaped, tubular, or layered. Alternatively, the solid alkenyl or aryl functional resin-linear polyorganosiloxane block copolymer may contain a first phase and an incompatible second phase, the first phase primarily containing linear blocks and the second phase primarily containing nonlinear blocks, the nonlinear blocks being sufficiently aggregated into nanodomains incompatible with the first phase.

[0019] Each molecule of an alkenyl or aryl functional resin-linear polyorganosiloxane block copolymer may have at least one alkenyl group (R... 1 As described and exemplified below, each alkenyl group is covalently bonded to a silicon atom. The alkenyl, aryl functional resin-linear polyorganosiloxane block copolymer may have an alkenyl group content of 0.5 mol% to 5 mol%, alternatively 0.5 mol% to 4.5 mol%, alternatively 0.8 mol% to 4 mol%, alternatively 1 mol% to 4 mol%, alternatively 1 mol% to 3 mol%, and alternatively 2 mol% to 3 mol%.

[0020] The alkenyl group (R) mentioned in this article 1 The alkenyl group may have 2 to 20 carbon atoms, alternatively 2 to 12 carbon atoms, alternatively 2 to 10 carbon atoms, alternatively 2 to 8 carbon atoms, and alternatively 2 to 6 carbon atoms. The alkenyl group may have a terminal alkenyl functional group, for example, R... 1 It can have a formula Where the subscript y ranges from 0 to 18. Alternatively, for each R 1 It can be independently selected from the group consisting of vinyl, allyl, and hexenyl. Alternatively, each R 1It can be independently selected from the group consisting of vinyl and allyl groups. Alternatively, each R 1 It can be independently selected from the group consisting of vinyl and hexenyl groups. Alternatively, each R 1 It can be vinyl.

[0021] In addition to the alkenyl group, the monovalent hydrocarbon groups (e.g., R) in alkenyl and aryl functionalized polyorganosiloxane resins-linear block copolymers 2 and R 3 The alkyl group can be selected from alkyl groups and aryl groups. Suitable alkyl groups can be straight-chain, branched, cyclic, or a combination of two or more of these. The alkyl group can have 1 to 30 carbon atoms, alternatively 1 to 20 carbon atoms, alternatively 1 to 10 carbon atoms, alternatively 1 to 6 carbon atoms, and alternatively 1 to 4 carbon atoms. Examples of alkyl groups include methyl, ethyl, propyl (including n-propyl and / or isopropyl), butyl (including n-butyl, tert-butyl, sec-butyl, and / or isobutyl); pentyl, hexyl, heptyl, octyl, decyl, dodecyl, undecyl, and octadecyl (and branched isomers having 5 to 30 carbon atoms), and examples of alkyl groups also include cycloalkyl groups, such as cyclopropyl, cyclobutyl, cyclopentyl, and cyclohexyl. Alternatively, the alkyl group may be selected from the group consisting of: methyl, ethyl, propyl, and butyl; alternatively, methyl, ethyl, and propyl; alternatively, methyl and ethyl. Alternatively, each alkyl group may be methyl. Alternatively, in the inclusion formula (R... 2 R 3 SiO 2 / 2 In the linear block of the unit, each R 2 and each R 3 It can be an alkyl group, and alternatively each R 2 and each R 3 It can be methyl.

[0022] Suitable aryl groups can have 6 to 30 carbon atoms, alternatively 6 to 20 carbon atoms, or alternatively 6 to 12 carbon atoms. The aryl group can be monocyclic or polycyclic and can have side hydrocarbon groups. For example, aryl groups include phenyl, tolyl, xylyl, and naphthyl, and also include aralkyl groups such as benzyl, 1-phenylethyl, and 2-phenylethyl. Alternatively, the aryl group can be monocyclic, such as phenyl, tolyl, or benzyl; and alternatively, each aryl group can be phenyl.

[0023] Examples of alkenyl and aryl functionalized polyorganosiloxane resin-linear block copolymers are known in the art and can be prepared by known methods, such as those disclosed in U.S. Patent 9,765,192 to Horstman et al. and U.S. Patent 10,793,681 to Swier et al., both of which are hereby incorporated by reference.

[0024] Alternatively, the alkenyl and aryl functionalized polyorganosiloxane resin-linear block copolymers used herein may comprise at least one of the units of formula (I) and formula (II), wherein formula (I) is And equation (II) is , where R 1 It is an alkenyl group as described above, R 4 It is an aryl group as described above, and R 2 and R 3 Each is independently a selected alkyl group as described above. In formula (II), R 5 and R 6 This represents a monovalent hydrocarbon group with 1 to 30 carbon atoms, which can be an alkyl group, alkenyl group, or aryl group as described above. Alternatively, R 5 It can be an alkyl group. Alternatively, R 6 It can be an alkenyl group or an aryl group, alternatively an aryl group. Alternatively, in formulas (I) and (II), each R 1 It can be vinyl, each R 2 It can be methyl, each R 3 It can be methyl, each R 4 It can be phenyl, each R 5 It can be methyl, and each R 6 It can be vinyl or phenyl, alternatively phenyl. Alternatively, the alkenyl, aryl functionalized polyorganosiloxane resin-linear block copolymer can have units of formula (I) that connect linear and nonlinear blocks.

[0025] Alternatively, the alkenyl, aryl functionalized polyorganosiloxane resin-linear block copolymer containing units of formula (I) and / or formula (II) may contain 20 mol% to 60 mol% of formula (R) 4 SiO 3 / 2 ) of T 芳基 Unit, where R 4 It is an aryl group as described above; optionally at least 25 mol% and optionally at least 28 mol% of the above-mentioned T 芳基 Unit; alternatively, not exceeding 55 mol% or 52 mol% of the above-mentioned T 芳基 unit.

[0026] Alternatively, the alkenyl, aryl functionalized polyorganosiloxane resin-linear block copolymer comprising units of formula (I) and / or formula (II) may comprise 0.5 mol% to 4.5 mol% of formula (R) 1 SiO 3 / 2 ) of T 烯基Unit; alternatively at least 0.8 mol% and alternatively at least 1.0 mol% of the above-mentioned T 烯基 Unit; additionally, not exceeding 4 mol%, not exceeding 3 mol%, and not exceeding 2.5 mol% of the above-mentioned T 烯基 Unit. Alternatively, the alkenyl, aryl functionalized polyorganosiloxane resin-linear block copolymer comprising units of formula (I) and / or formula (II) may comprise 40 mol% to 80 mol% of formula (R). 2 R 3 SiO 2 / 2 The difunctional siloxy group of the unit; alternatively at least 45 mol% or at least 48 mol% of the above-mentioned difunctional siloxy group; alternatively not more than 75 wt% or at least 72 wt% of the above-mentioned difunctional siloxy group. Alternatively, T 芳基 The units are arranged in a nonlinear block configuration, each nonlinear block having a molecular weight of at least 500 g / mol. Alternatively, the alkenyl or aryl functionalized polysiloxane resin-linear block copolymer has a weight-average molecular weight of at least 20,000 g / mol. Alternatively, at least 50 mol% of units having alkenyl groups are present as T units, and alternatively at least 60 mol%, alternatively at least 70 mol%, alternatively at least 80 mol%, and alternatively at least 90 mol% of units having alkenyl groups are present as T units.

[0027] Structural analysis, for example, can be used to determine the average number of bifunctional siloxane units in the aforementioned alkenyl and aryl functionalized polyorganosiloxane resin-linear block copolymers. 29 Si NMR was performed as follows: 5 g of the alkenyl and aryl functionalized resin-linear polyorganosiloxane block copolymer as described above was mixed with 1 ml of D6-benzene for NMR characterization. The NMR values ​​of each product were collected using a Bruker 600MHz NMR instrument. 29 Si NMR spectrum (NS=256, d1=60).

[0028] Based on the combined weight of all starting materials in the composition (excluding solvents, if used), the amount of starting material (A) in the composition may be from 85% to 99%. Alternatively, on the same basis, the amount of starting material (A) may be at least 85%, alternatively at least 86%, alternatively at least 87%, alternatively at least 88%, alternatively at least 89%, and alternatively at least 90%; while simultaneously, the amount of starting material (A) may be at most 99%, alternatively at most 98%, alternatively at most 97.5%, alternatively at most 97%, and alternatively at most 96%.

[0029] (B) Organic thiol functional crosslinking agents

[0030] The starting material (B) is an organic thiol-functionalized crosslinking agent having at least two, alternatively two to four thiol functional groups per molecule. The organic thiol-functionalized crosslinking agent may be selected from compounds having formula (BI), compounds having formula (B-II), and combinations thereof, wherein: formula (BI) is R' m CX (4-m) In this context, each R' is an independently chosen alkyl group with 1 to 20 carbon atoms, the subscript m is an integer with a value of 2, 3, or 4, and each X is independently a formula... The thiol functional group, where the subscript p is an integer with a value of 0 or 1; and formula (B-II) is X'-R''-X', where R'' is an alkylene group with 1 to 20 carbon atoms, and X' is a group having a thiol functional group selected from... or The formula (BI) contains a thiol functional group, where the subscript p is an integer with a value of 0 or 1. Alternatively, in formula (BI), R' can be methyl, ethyl, propyl, or butyl; or methyl or ethyl. Alternatively, in formula (BI), the subscript m can be 3 or 4. Examples of compounds of formula (BI) include trimethylolpropane tris(3-mercaptopropionate) (CAS#33007-83-92) and pentaerythritol tetra(3-mercaptopropionate) (CAS#7575-23-7), both of which are commercially available from TCI America. Alternatively, in formula (B-II), R'' can be an alkylene group with 2 to 16 carbon atoms, alternatively 4 to 14 carbon atoms, alternatively 6 to 12 carbon atoms, and alternatively 8 to 10 carbon atoms. Examples of compounds of formula (B-II) include 3,6-dioxa-1,8-octanedithiol (CAS#14970-87-7), ethylene glycol bis(thioglycolic acid) (CAS#123-81-9); 1,4-butanediol bis(thioglycolic acid) (CAS#10193-95-0), hexanediol bis(thioglycolic acid), ethylene glycol bis(3-mercaptopropionic acid) (CAS#22504-50-3), and 1,4-butanediol bis(3-mercaptopropionic acid) (CAS#92140-97-1), which are also available from TCI America or Alpha Chemical. Other examples of organic thiol-functionalized crosslinking agents for starting material (B) are disclosed, for example, in column 5, lines 13 to 22 of U.S. Patent 10,604,653, and include o-xylene dithiol, m-xylene dithiol, or p-xylene dithiol.

[0031] The amount of (B) organic thiol-functionalized crosslinking agent in the composition depends on various factors, including the amount and selection of starting materials (A) and (C), and the presence of any additional starting materials (D), (E), and / or (F); however, the amount of (B) organic thiol-functionalized crosslinking agent can be from 0.5% to 14.9%. Alternatively, based on the combined weight of all starting materials in the composition (excluding solvents (if used)), the amount of starting material (B) can be at least 1%, alternatively at least 1.5%, alternatively at least 2%, alternatively at least 3%, alternatively at least 4%, and alternatively at least 5%; while the amount of starting material (B) can be at most 14.9%, alternatively at most 14%, alternatively at most 13%, alternatively at most 12%, alternatively at most 11%, and alternatively at most 10.5%.

[0032] (C) Photoradical initiators

[0033] The starting material (C) in this composition is a photoradical initiator. Suitable photoradical initiators include ultraviolet (UV) initiators, such as benzophenone and benzophenone derivatives, acetophenone and acetophenone derivatives, benzoin and its alkyl esters and phosphine oxide derivatives. Suitable commercially available photoinitiators include 2,6-bis(4-azidobenzyl)cyclohexanone; 2,6-bis(4-azidobenzyl)-4-methylcyclohexanone; 1-hydroxy-cyclohexyl-phenyl-one (CAS# 947-19-3, also known as OMNIRAD). ™ 184 obtained); 2-Methyl-1-[4-(methylthio)phenyl]-2-morpholinylpropane-1-one (CAS# 718-10-5, can be named OMNIRAD) ™ 907 obtained); 2-hydroxy-2-methyl-1-phenyl-propane-1-one (CAS# 7473-98-5, can be named OMNIRAD) ™ 1173 obtained); 50% benzophenone (CAS# 119-61-9) and 50% OMNIRAD ™ 184C mixed initiator (this mixed initiator can be named OMNIRAD) ™ 500 obtained); 20% OMNIRAD ™ 184C and 80% OMNIRAD ™ 1173 mixed initiator (this mixed initiator can be named OMNIRAD) ™ 1000 obtained); 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methylpropanone (CAS# 106797-53-9, can be named OMNIRAD) ™2959 obtained); methyl benzoylformate (CAS# 152-55-0, also known as OMNIRAD) ™ MBF is available); 2,2-Dimethoxy-2-phenylacetophenone (CAS# 24650-42-8, also known as OMNIRAD) ™ (obtained by BDK); 2-benzyl-2-(dimethylamino)-4'-morpholinobutyroylbenzene (CAS# 119313-12-1, can be named OMNIRAD) ™ 369 obtained); diphenyl (2,4,6-trimethylbenzoyl)phosphine oxide (CAS# 75980-60-8, can be named OMNIRAD) ™ TPO obtained); (2,4,6-trimethylbenzoyl)phenylphosphine ethyl ester (CAS# 84434-11-7, can be named OMNIRAD) ™ TPO-L (obtained), and combinations of two or more of them. OMNIRAD ™ The branded photoradical initiator is commercially available from IGM Resins BV, Netherlands. Other photoradical initiators are commercially available from other sources, and are described, for example, as in PCT Patent Publication WO2024039544 and U.S. Patent 11,827,799.

[0034] The amount of photoradical initiator (C) in the composition depends on various factors, including the type and amount of starting materials (A) and (B) and the presence of any additional starting materials (D) and / or (E). However, based on the combined weight of all starting materials in the composition (excluding solvents, if used), the amount of starting material (C) can be from 0.1% to 10%. Alternatively, on the same basis, the amount of starting material (C) can be at least 0.1%, alternatively at least 0.2%, alternatively at least 0.3%, alternatively at least 0.4%, and alternatively at least 0.5%; while simultaneously, the amount of starting material (C) can be at most 10%, alternatively at most 7.5%, alternatively at most 5%, alternatively at most 2.5%, alternatively at most 1%, and alternatively at most 5%.

[0035] (D) Stabilizer

[0036] Optionally, the composition may further comprise (D) a UV stabilizer. UV stabilizers are free radical scavengers that can extend the storage stability of the composition by inhibiting curing until the composition is intentionally exposed to UV radiation. UV stabilizers include phenolic compounds such as 4-methoxyphenol (MEHQ, a methyl ether of hydroquinone), hydroquinone, 2-methylhydroquinone, 2-tert-butylhydroquinone, tert-butylcatechol, butylated hydroxytoluene, and butylated hydroxyanisole. Other types of UV stabilizers include phenothiazines and anaerobic inhibitors, such as NPAL-type inhibitors (tris(N-nitroso-N-phenylhydroxylamine) aluminum salt) available from Albemarle Corporation.

[0037] Alternatively, the stabilizer used herein may be an inhibitor comprising a manganese ion source and a phenolic compound. The manganese ion source used herein may be a manganese(III) compound or a manganese(II) compound. Alternatively, the manganese ion source may be a manganese(II) compound. Suitable manganese compounds include manganese(II) acetate, manganese(II) nitrite, manganese(II) propionate, manganese(II) oxide, manganese(II) hydroxide, manganese(II) chloride, manganese(II) phosphate, manganese(II) perchlorate, their hydrates (e.g., manganese(II) tetrahydrate), and combinations thereof. Alternatively, the manganese ion source may comprise manganese(II) acetate or manganese(II) tetrahydrate, or combinations thereof. Suitable manganese ion sources are commercially available from Millipore Sigma of St. Louis, Missouri, USA, Fisher Scientific of Waltham, Massachusetts, USA, and Chemical LLC of Connecticut, USA. The amount of manganese ion source depends on various factors, including the choice and amount of the starting material used herein, as well as the heating time and temperature. However, based on the combined weight of all starting materials in the composition (excluding solvents, if used), the amount of manganese ion source can be from 0.1 ppm to 5,000 ppm, alternatively from 0.1 ppm to 1,000 ppm. Alternatively, on the same basis, the amount of manganese ion source can be >0 ppm, alternatively at least 0.1 ppm, alternatively at least 0.5 ppm, alternatively at least 1 ppm, alternatively at least 1.5 ppm; while the amount of manganese ion source can be up to 5,000 ppm, alternatively up to 1,000 ppm, alternatively up to 100 ppm, alternatively up to 10 ppm, alternatively up to 5 ppm, alternatively up to 4 ppm, and alternatively up to 3 ppm and alternatively up to 2 ppm.

[0038] The phenolic compounds used in this invention have one or more phenolic groups per molecule. Suitable phenolic compounds include hydroquinone (HQ), dihydroxybenzene (catechol), resorcinol, dihydroxyxylene, methoxyphenol (such as guaiacol, p-methoxyphenol (also known as the methyl ether of hydroquinone or MeHQ)), tert-butylhydroquinone (tBuHQ), pyrogallol, methylpyrogallol, cresol, phenol, xylenol, and combinations thereof. Alternatively, the phenolic compound may be selected from the group consisting of HQ, MeHQ, tBuHQ, and combinations of two or more thereof. Suitable phenolic compounds are commercially available, for example, from Millipore Sigma of St. Louis, Missouri, USA. The amount of phenolic compound source depends on various factors, including the selection and amount of starting materials used in the composition; however, based on the combined weight of all starting materials in the composition (excluding solvents, if used), the amount can be from 5 ppm to 5,000 ppm. Alternatively, on the same basis, the amount of phenolic compounds may be at least 5 ppm, alternatively at least 50 ppm, alternatively at least 100 ppm, alternatively at least 150 ppm; while at the same time, the amount of phenolic compounds may be at most 500 ppm, alternatively at most 400 ppm, alternatively at most 350 ppm and alternatively at most 320 ppm.

[0039] Alternatively, the amount of UV stabilizer in the composition may be 0% or more, alternatively 0.1% or more, alternatively 0.5% or more, alternatively 1.0% or more and alternatively 1.5% or more; while the amount of stabilizer may be 2.0% or less, alternatively 1.5% or less, alternatively 1.0% or less and alternatively 0.5% or less, each based on the combined weight of all starting materials in the composition.

[0040] (E) Adhesion promoter

[0041] Optionally, the composition may also contain (E) an adhesion promoter. Suitable adhesion promoters include organosilicon compounds having at least one silicon-bonded alkoxy group per molecule. Examples of the alkoxy group are methoxy, ethoxy, propoxy, butoxy, or methoxyethoxy groups. Alternatively, the alkoxy group may be a methoxy group. In addition, examples of silicon-bonded groups in organosilicon compounds, other than alkoxy groups, include halogenated or unsubstituted monovalent hydrocarbon groups, such as alkyl groups, alkenyl groups, aryl groups, aralkyl groups, haloalkyl groups, haloaryl groups, and haloaralkyl groups; epoxy functional groups, such as glycidoxyalkyl groups, such as 3-glycidoxypropyl groups and 4-glycidoxybutyl groups; epoxycyclohexylalkyl groups, such as 2-(3,4-epoxycyclohexyl)ethyl groups and 3-(3,4-epoxycyclohexyl)propyl groups; and epoxyalkyl groups, such as 3,4-epoxybutyl groups and 7,8-epoxyoctyl groups; monovalent organic groups containing (meth)acrylic acid groups, such as 3-methacryloyloxypropyl groups; and hydrogen atoms. Adhesion promoters may contain groups that can react with the alkenyl groups of the starting material (A). For example, adhesion promoters may contain silicon-bonded hydrogen atoms. Furthermore, adhesion promoters can possess at least one epoxy functional group per molecule because they can impart good adhesion to various types of substrates. Examples of this type of adhesion promoter are organosilane compounds, organosiloxane oligomers, and alkyl silicate esters. Examples of molecular structures for organosiloxane oligomers or alkyl silicate esters include straight-chain, partially branched straight-chain, branched, cyclic, and network structures. Straight-chain, branched, and network structures are particularly preferred. Examples of adhesion promoters are silane compounds, such as 3-glycidoxypropyltrimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, and 3-methacryloyloxypropyltrimethoxysilane; siloxane compounds having at least one silicon-bonded alkenyl group or each of a silicon-bonded hydrogen atom and a silicon-bonded alkoxy group in the molecule; silane compounds having at least one silicon-bonded alkoxy group or mixtures of siloxane compounds having at least one silicon-bonded hydroxyl group and at least one silicon-bonded alkenyl group in the molecule; and methyl polysilicates, ethyl polysilicates, and ethyl polysilicates containing epoxy groups. Adhesion promoters can be low-viscosity liquids, and their viscosity is not particularly limited, but can be from 1 millipascal (mPa) to 500 mPa at 25°C.

[0042] The amount of adhesion promoter (E) in the composition may be 0% or more, alternatively 0.1%, alternatively 0.5% or more, alternatively 1.0% or more and alternatively 1.5% or more; while the amount of adhesion promoter may be 2.0% or less, alternatively 1.5% or less, alternatively 1.0% or less and alternatively 0.5% or less, each based on the combined weight of all starting materials in the composition.

[0043] (F) Solvent

[0044] Optionally, the composition may also include solvent (F). Suitable solvents are those capable of dissolving starting materials (A), (B), and / or (C). Typically, starting material (A) can be prepared in a solvent such as aromatic hydrocarbons, examples of which are benzene, toluene, xylene, or combinations thereof; aliphatic hydrocarbons, such as hexane, heptane, octane, or combinations thereof; or a combination of aromatic and aliphatic hydrocarbons. The solvent can be used to facilitate the mixing of the aforementioned starting materials and can optionally be removed from the composition after mixing. For example, the composition can be prepared by a method comprising mixing starting materials (A), (B), (C), and (D), (E), and (F) in their presence at room temperature or under heating. Alternatively, one or more of starting materials (A), (B), (C), (D), and / or (E) can be dissolved in solvent (F) before being mixed with other starting materials. For example, the starting material (A) can be dissolved in solvent (F) before mixing the alkenyl or aryl functionalized polyorganosiloxane resin-linear block copolymer with starting materials (B) and (C), and, where present, starting materials (D) and (E). The method for preparing the composition may also include removing all or part of solvent (F) after mixing, thereby rendering the composition non-flowable at 25°C.

[0045] It is worth noting that the compositions of the present invention may be free of hydrogenation silylation reaction catalysts, such as platinum catalysts. Therefore, the compositions may be platinum-free, which is desirable for avoiding yellowing of the compositions and / or the cured products of the compositions, and for keeping costs lower than systems requiring platinum catalysts.

[0046] The composition of this invention can be non-flowable at 25°C and can have a viscosity of 5000 Pa·s or less, and alternatively 1000 Pa·s or less, at 120°C. For the purposes of this application, "non-flowable" means a state in which it does not flow when no load is applied, and refers to a condition below the softening point measured by the ring and ball method of hot melt adhesives as specified in JIS K 6863-1994 "Method for Testing the Softening Point of Hot Melt Adhesives". That is, in order to be non-flowable at 25°C, the softening point of the composition needs to be higher than 25°C. This is because if the composition is non-flowable at 25°C, excellent shape retention properties are achieved at that temperature. In addition, if the melt viscosity at 120°C is 5000 Pa·s or less, it is easy to process into various forms. Since this composition is non-flowable at 25°C, it can be processed into various forms and, for example, can be made into films with a thickness of 5 μm to 5 mm. Examples of radiation used to cure the composition include ultraviolet light, but electron beams and / or radiation may also be used alternatively. Examples of devices emitting ultraviolet radiation include high-pressure mercury lamps, medium-pressure mercury lamps, and ultraviolet LEDs.

[0047] The cured product of the present invention is obtained by irradiating the above-described composition. If irradiation is performed at a temperature at which the composition of the present invention does not exhibit flowability, a cured product having the form of the composition before curing can be obtained. The form of the cured product is not limited; however, the form can be a film.

[0048] Methods for producing membranes

[0049] The method for producing the film according to the present invention may include: sandwiching the above composition between two peelable transparent films, forming the composition to a fixed thickness, and then irradiating the composition.

[0050] The composition can be sandwiched between the membranes by any convenient means, such as depositing the composition on the surface of the first membrane, removing (F) solvent (if present), and then placing the second membrane on the surface of the composition opposite the surface of the first membrane. Alternatively, the composition (solvent-free) can be placed between the membranes and then formed to a fixed thickness by thermal compression or heated rollers.

[0051] Irradiation can be performed through a transparent film, or the composition can be directly irradiated after removing one or both of the aforementioned transparent films. Peelable transparent films that can be used in this method include transparent films that inherently exhibit peelability and transparent films obtained by adding or applying a release agent to a transparent film with low peelability. Examples of peelable transparent films include silicone-grafted polyacrylate resin films or polyolefin resin films, as well as fluorinated polyolefin resin films. Examples of transparent films with added or applied release agents include polyester resin films, polyolefin resin films, and polyethylene terephthalate films.

[0052] The present invention further relates to a method for using the composition described herein as a curable coating on a substrate. The method includes the steps of softening the composition by heating, thereby forming a softened composition, and forming the softened composition on at least a portion of the substrate. It can be formed by any convenient method such as vacuum lamination. The method may also include exposing the composition to ultraviolet radiation to cure the composition.

[0053] Alternatively, the composition can be used to form an encapsulant for light-emitting diodes (LEDs). In such applications, the method is as described above, and a substrate on which the composition is formed comprises an LED. The composition covers the LEDs, thereby encapsulating them, and the composition is then cured by exposure to UV radiation.

[0054] The present invention also includes an article comprising a composition (or a cured product thereof forming an encapsulant) covering at least a portion of a substrate surface. Desiredly, and most desirously, the substrate portion covered by the composition (or encapsulant) may include a light-emitting diode.

[0055] Example

[0056] The following embodiments are provided to illustrate the invention to those skilled in the art, and these embodiments should not be construed as limiting the scope of the invention as set forth in the claims. The starting materials used in these embodiments are summarized in Table 1 below.

[0057] Table 1—Starting Materials

[0058]

[0059] In Table 1, 3,6-dioxa-1,8-octanedithiol (X-connector 1) has the formula: Trimethylolpropane tris(3-mercaptopropionate) (X-connector 2) has the formula: Furthermore, pentaerythritol tetra(3-mercaptopropionate) (X-connector 3) has the formula: .

[0060] As used in the following examples, ETFE film refers to Chemours Tefzel. ™ ETFE membrane.

[0061] In this synthetic example 1, silanol-terminated PDMS with DP=80 was prepared as follows: 1,500.0 g of starting material XIAMETER was used. ™ PMX-0156 was added to a 2L 3-necked round-bottom flask equipped with a PTFE stirrer and thermocouple, with one neck kept open, while purging with nitrogen at a flow rate of 1.5 standard cubic feet per hour. 0.515 g of a 3% potassium hydroxide solution was added to the flask at 90°C. After 3 hours and 50 minutes at 90°C, 1.62 g of a 2.5% phosphoric acid aqueous solution was added. The solution was cooled to 25°C and purged with nitrogen overnight to remove water. The resulting material was filtered through a 0.45 μm nylon filter to obtain PDMS1 (bissilanol-terminated polydimethylsiloxane). 29 Si NMR confirmed that PDMS 1 has a DP of 80.

[0062] In this synthetic example 2, the alkenyl, aryl functional resin-linear polyorganosiloxane block copolymer RL1 was prepared as follows: 217 flakes (90.0 g), toluene (240.8 g), and an amount of toluene equal to the volume of the Dean Stark apparatus were loaded into a 1 L four-necked round-bottom flask equipped with a thermocouple, a Teflon stirrer, and a water-cooled condenser. An inert gas covering was then applied. The mixture was refluxed for 30 minutes to remove any water present in the mixture.

[0063] Meanwhile, vinyltriacetoxysilane (VTA, 8.50 g) and XIAMETER were added to a 500 ml round-bottom flask. ™ OFS-1579 (3.45 g) was added to a mixture of toluene (59.2 g) and disilanol-terminated PDMS (110.0 g, dp=63) to prepare diacetoxysilane-terminated PDMS. The mixture was stirred at room temperature for 1 hour. The diacetoxysilane-terminated PDMS was then rapidly added to a flask containing 217 film at 106 °C. The reaction mixture was then refluxed for 2 hours. The reaction mixture was then cooled to 106 °C and XIAMETER was added. ™OFS-1579 (6.14 g). After reflux for 1 hour, the reaction temperature was cooled to 90°C and deionized water (28.2 g) was added. Water and acetic acid byproducts were removed by azeotropic distillation. The steps of adding and removing water were repeated once more. Then, volatiles were removed to prepare a concentrated solution (100.0 g of volatiles removed). The steps of adding and removing water were repeated three times. A semi-transparent solution was obtained after filtration. The sample contained an alkenyl, aryl functional resin-linear polyorganosiloxane block copolymer labeled RL1.

[0064] In this synthetic example 3, the alkenyl, aryl functional resin-linear polyorganosiloxane block copolymer RL2 was prepared as follows: 217 flakes (270.0 g), toluene (722.3 g), and an amount of toluene equal to the volume of the Dean Stark apparatus were loaded into a 3L four-necked round-bottom flask equipped with a thermocouple, a Teflon stirrer, and a water-cooled condenser. An inert gas covering was then applied. The mixture was refluxed for 30 minutes to remove any water present in the mixture.

[0065] Meanwhile, vinyltriacetoxysilane (VTA, 25.50 g) and XIAMETER were added to a 500 ml round-bottom flask. ™ OFS-1579 (10.36 g) was added to a mixture of toluene (177.7 g) and bissilanol-terminated PDMS (330.0 g, dp=63) to prepare diacetoxysilane-terminated PDMS. The mixture was then stirred at room temperature for 1 hour. The diacetoxysilane-terminated PDMS was prepared and rapidly added to a flask containing 217 flakes at 106 °C. The reaction mixture was then refluxed for 2 hours. After cooling the reaction mixture to 90 °C, deionized water (56.0 g) was added. Water and acetic acid byproducts were removed by azeotropic distillation. The steps of adding and removing water were repeated once more. Then, volatiles were removed to prepare a concentrated solution (300.0 g of volatiles were removed). The steps of adding and removing water were repeated three times. A semi-transparent solution was obtained after filtration. The sample contained an alkenyl, aryl functional resin-linear polyorganosiloxane block copolymer labeled RL2.

[0066] In this synthetic example 4, the alkenyl, aryl functional resin-linear polyorganosiloxane block copolymer RL3 was prepared as follows: 217 flakes (90.0 g), toluene (240.8 g), and an amount of toluene equal to the volume of the Dean Stark apparatus were loaded into a 1 L four-necked round-bottom flask equipped with a thermocouple, a Teflon stirrer, and a water-cooled condenser. An inert gas covering was then applied. The mixture was refluxed for 30 minutes to remove any water present in the mixture.

[0067] Meanwhile, diacetyloxysilane-terminated PDMS was prepared by adding vinyltriacetyloxysilane (VTA, 9.44 g) to a mixture of toluene (59.2 g) and PDMS 1 (prepared as described in Synthesis Example 1 above) (110.0 g, DP=80) in a 500 ml round-bottom flask. The mixture was then stirred at room temperature for 1 hour. The diacetyloxysilane-terminated PDMS was prepared and rapidly added to a flask containing 217 flakes at 106 °C. The reaction mixture was then refluxed for 2 hours. After cooling the reaction mixture to 106 °C, XIAMETER was added. ™ OFS-1579 (4.60 g). The mixture was then refluxed for 1 hour. The reaction mixture was cooled to room temperature and deionized water (21.8 g) was added. Water and acetic acid byproducts were removed by azeotropic distillation. The water addition and dehydration steps were repeated. Then, volatiles (100 g) were removed to prepare a concentrated solution. The water addition and dehydration steps were repeated three times. A translucent solution was obtained after filtration. The sample contained an alkenyl, aryl functional resin-linear polyorganosiloxane block copolymer labeled RL3.

[0068] In this synthetic example 5, the resin-linear polyorganosiloxane block copolymer (without alkenyl groups) RL4 was synthesized as follows (comparative):

[0069] 217 flakes (90.0 g), toluene (240.8 g), and an amount of toluene equal to the volume of the Dean Stark apparatus were loaded into a 1 L four-necked round-bottom flask equipped with a thermocouple, a Teflon stirrer, and a water-cooled condenser. An inert gas covering was then applied. The mixture was refluxed for 30 minutes to remove any water present.

[0070] Meanwhile, by adding XIAMETER to a 500ml round-bottom flask ™ OFS-1579 (11.78 g) was added to a mixture of toluene (59.3 g) and bissilanol-terminated PDMS (110.0 g, dp=63) to prepare diacetoxysilane-terminated PDMS. The mixture was then stirred at room temperature for 1 hour. The prepared diacetoxysilane-terminated PDMS was rapidly added to a flask containing 217 flakes at 106 °C. The reaction mixture was then refluxed for 2 hours. The reaction mixture was cooled to room temperature and deionized water (18.7 g) was added. Water and acetic acid byproducts were removed by azeotropic distillation. The steps of adding and removing water were repeated. Then, volatiles were removed to prepare a concentrated solution. The steps of adding and removing water were repeated three times. A clear solution was obtained after filtration. The sample contained a resin-linear polyorganosiloxane block copolymer labeled RL4.

[0071] The resin-linear polyorganosiloxane block copolymers prepared as described above are summarized in Table 2 below.

[0072] Table 2—Ph T-PDMS RL copolymers used in this invention and related information

[0073]

[0074] The samples RL1, RL2, RL3, and RL4 (toluene solution of resin-linear polyorganosiloxane block copolymer) prepared as described above were used to prepare curable compositions and their films (SHF): The toluene solution of resin-linear polyorganosiloxane block copolymer, an organic thiol functional crosslinking agent, and a photoradical initiator were placed in a dental cup and uniformly mixed in a dental mixer. The prepared compositions were coated onto an ETFE film to prepare a 200 mm thick film and dried at 70°C for 1 hour. The starting materials and amounts in each composition are shown in Tables 3 and 4 below.

[0075] The viscoelastic properties of the uncured composition were evaluated as follows: Viscoelastic properties of the uncured SHF, such as complex viscosity, storage modulus, and Tan(δ), were determined using a rotational rheometer (ARES-G2 from TA Instruments). Viscoelastic profiles were obtained using a 1 mm thick sample and a 25 mm parallel plate. After loading the sample onto the parallel plate, the sample was equilibrated at 20 °C for 5 minutes. The temperature was then increased to 120 °C at a rate of 3 °C / min.

[0076] The curing procedure for the membrane was as follows: UV irradiation at 365 nm using Raven via UVitron SkyRay. After preparing the SHF on the ETFE membrane, another ETFE membrane was placed on top of the SHF. The SHF sandwiched between the ETFE membranes was placed in a UV chamber. Then, it was irradiated with UV rays at 365 nm (250 mW, for 16 seconds). After flipping, another UV irradiation was performed. The total dose was 8 J / cm². 2 (4J / cm per side) 2 ).

[0077] The gel percentage of the cured film was determined as follows. First, a known amount of cured SHF sample (1.0 g) was placed in a 40 ml toothed cup. Next, 15.0 g of toluene was added to the cup containing the SHF sample, and the cup was shaken for 1 hour. After decanting the toluene solution from the toothed cup, the undissolved sample was transferred to an aluminum tray. The sample was dried at 120°C for 2 hours. The dried sample was then weighed. "Cureability" was determined by the gel percentage experiment described below. "Good curability" means that the cured percentage after UV irradiation is ≥50%.

[0078] The determination of total transmittance (T%) is evaluated as follows: T% was obtained using the ASTM D1003 method via Haze Gard Plus.

[0079] The test results for each sample are shown in Tables 3 and 4 below.

[0080] Table 3—Comparative Examples

[0081]

[0082] In Table 3, ND indicates not detected. The data in Table 3 show that when the resin-linear polyorganosiloxane block copolymer does not have alkenyl groups (Comparative Example 1, CE.1), the composition does not cure under the test conditions. When the photoradical initiator is omitted (in CE.2), the composition also does not cure under the test conditions. When the crosslinking agent is omitted or contains insufficient thiol functional groups (CE.3 and CE.4), the composition also does not cure under the test conditions. CE.5 shows that when a polydiorganosiloxane resin is used instead of an alkenyl or aryl functional resin-linear polyorganosiloxane block copolymer, the composition is flowable at 25°C and has insufficient complex viscosity characteristics for the purposes of this application. CE.6 shows that when too much crosslinking agent is used, the composition is flowable at 25°C and has insufficient complex viscosity characteristics for the purposes of this application.

[0083] Table 4—Work Examples

[0084]

[0085] The data in Table 4 show that the non-flowing state at 25°C and the complex viscosity ratio (η*) at 25°C and 120°C are... 在25℃ / η* 在120℃ Curable silicone compositions with a curable density of ≥20, or alternatively ≥100, can be prepared using alkenyl and aryl functional resin-linear polyorganosiloxane block copolymers from the compositions described herein. Furthermore, these radiation-curable polyorganosiloxane resin-linear copolymer compositions possess a storage modulus of >0.01 MPa, or alternatively >0.1 MPa, at 25°C, and a tan(δ) of <5.0, or alternatively <2.0, at 25°C, as measured using the above-described test methods. These curable silicone compositions can be cured to form cured products that can be used as encapsulants, exhibiting good optical transparency (>94%, or alternatively >95%, up to 100%) and good curability (gel % >67%) as measured using the above-described test methods. Examples 1, 2, and 3 show that different thiol-functionalized crosslinking agents can be used. Example 4 shows that the compositions described herein are curable even under low photoradical initiator loadings. Examples 5 and 6 show that various amounts of crosslinking agents can be used in the compositions described herein.

[0086] Due to the robust solid properties of SHF prepared from alkenyl and aryl functional resins-linear polyorganosiloxane block copolymers at room temperature, the inventors were concerned that the effectiveness of UV curing would be limited by a slow diffusion rate. However, the inventors surprisingly discovered that UV irradiation for less than 1 minute at 25°C or less provided a cured film.

[0087] Industrial applicability

[0088] In the optoelectronics industry, there is a need for encapsulants that can be made from curable compositions that cure at ≤25°C for a short time (i.e., less than 5 minutes, and alternatively less than 1 minute of UV irradiation) to improve productivity and protect fragile optoelectronic display components. Silicone curing techniques are typically based on hydrosilanization curing, which requires high temperatures and / or long curing times. Therefore, the radiation-curable polysiloxane resin-linear copolymer composition of the present invention (which can cure at ≤25°C for a short curing time) is desired to meet this need. The radiation-curable polysiloxane resin-linear copolymer composition of the present invention can be non-flowable at 25°C. The radiation-curable polysiloxane resin-linear copolymer composition can have a complex viscosity of 5000 Pa·s or less at 120°C, wherein the ratio (η*) of the complex viscosity at 25°C to the complex viscosity at 120°C is... 在25℃ / η* 在120℃ The radiation-curable polyorganosiloxane resin-linear copolymer composition may also have a storage modulus of >0.01 MPa, or alternatively >0.1 MPa, at 25°C, as measured by the above-described test method, and a Tan(δ) of <5.0, or alternatively <2.0, and alternatively <1.0 at 25°C.

[0089] Definition and use of terms

[0090] Unless the context otherwise indicates, all quantities, ratios, and percentages are by weight. Unless the context otherwise indicates, the articles “an,” “a,” and “described” each mean one (an) or more (a plurality of). Unless the context otherwise indicates, the singular form also includes the plural form. The summary of the invention and the abstract of the specification are incorporated herein by reference. The total amount of all starting materials in the composition is 100%. The transitional phrases “comprising,” “consistently consisting of,” and “composed of” are used as described in Chapters 2111.03 I, II, and III of the Patent Examining Procedure Ninth Edition, last revised January 2018, Amendment 08.2017. The use of “for example,” “for instance,” “such as,” and “comprising” to list exemplary examples does not imply limitation to the listed examples. Thus, “for example” or “such as” means “for example, but not limited to” or “such as, but not limited to” and covers other similar or equivalent examples. The scope of the disclosure includes the scope itself and any values ​​and endpoints contained therein. Similarly, the disclosure of the Markush group includes the entire group and also includes any individual members and subgroups contained therein. For example, the disclosure of hydrogen atoms, alkyl groups, alkenyl groups, or aryl groups in the Markush group includes the individual member alkyl; alkyl and aryl subgroups; and any other individual members and subgroups contained therein. Any feature or aspect of the invention may be used in combination with any other feature or aspect described herein. Abbreviations are defined in Table 7 below.

[0091] Table 7 – Abbreviations

[0092]

[0093]

[0094] Embodiments of the present invention

[0095] In a first embodiment of the present invention, an encapsulation method includes:

[0096] 1) A heat- and radiation-curable polyorganosiloxane resin-linear copolymer composition, wherein

[0097] The radiation-curable polyorganosiloxane resin-linear copolymer composition comprises

[0098] 85 to 99 parts by weight of (A) alkenyl, aryl functionalized polyorganosiloxane resin-linear block copolymer, wherein

[0099] The alkenyl and aryl functionalized polyorganosiloxane resin-linear block copolymer comprises linear and nonlinear blocks, wherein...

[0100] Each linear block independently contains 10 to 500 formulas (R). 2 R 3 SiO 2 / 2 The dimethylsilyloxy unit of ) wherein each R 2 and each R 3 It is a monovalent hydrocarbon group consisting of 1 to 30 carbon atoms, chosen independently;

[0101] Each nonlinear block has a number-average molecular weight of at least 500 g / mol, the nonlinear block comprising a trimethylsilyloxy unit and a hydrolyzable group, and wherein the nonlinear block further comprises an alkenyl group bonded to a silicon atom and an aryl group bonded to a silicon atom.

[0102] At least 30 mol% of the nonlinear blocks are cross-linked with each other;

[0103] Each linear segment is connected to at least one nonlinear segment, and

[0104] The copolymer has a weight-average molecular weight of at least 20,000 g / mol as measured by gel permeation chromatography.

[0105] 0.5 to 14.9 parts by weight of an (B) organic thiol-functionalized crosslinking agent having at least two thiol functional groups per molecule; and

[0106] 0.1 to 10 parts by weight of (C) photoinitiator, thereby forming a flowable composition;

[0107] 2) Forming the flowable composition on a substrate, and

[0108] 3) Irradiate the composition with ultraviolet radiation, thereby curing the composition to form an encapsulant on the substrate.

[0109] In a second embodiment, the method according to the first embodiment further includes producing a solid film of a radiation-curable polyorganosiloxane resin-linear copolymer composition prior to step 1).

[0110] In the third embodiment, in the method according to the first or second embodiment, step 2) includes vacuum lamination.

[0111] In the fourth embodiment, in the method according to any one of the first to third embodiments, a plurality of features are located on the substrate, and the features are encapsulated in step 3).

[0112] In a fifth embodiment, in the method according to the fourth embodiment, the feature includes a light-emitting diode.

[0113] In the sixth embodiment, in the method according to any one of the first to fifth embodiments, all steps of the method are performed at a temperature ≤80°C.

[0114] In the seventh embodiment, in the method according to any one of the first to sixth embodiments, the radiation-curable polyorganosiloxane resin-linear copolymer composition further comprises additional starting materials selected from the group consisting of: (D) stabilizers, (E) adhesion promoters, (F) solvents, and combinations of two or more of them.

[0115] In the eighth embodiment, the method according to the seventh embodiment further includes dissolving the alkenyl, aryl functional polyorganosiloxane resin-linear block copolymer of (A) in the solvent of (F), mixing the starting materials (A), (B), (C), (F) and optionally one or both of (D) and (E), and then removing the solvent of (F), thereby forming the radiation-curable polyorganosiloxane resin-linear copolymer composition prior to step 1).

[0116] In the ninth embodiment, in the method according to any one of the first to eighth embodiments, in the alkenyl, aryl functionalized polyorganosiloxane resin-linear copolymer of (A), each linear block is via formula A portion of it is connected to at least one nonlinear block, where each dashed line represents a covalent bond with another silicon atom in the molecule; R 1 It is an alkenyl group with 2 to 20 carbon atoms, each R 2 It is an alkyl group with 1 to 20 carbon atoms, each R 3 It is an alkyl group with 1 to 20 carbon atoms, chosen independently, and R 4 It is an aryl group with 6 to 20 carbon atoms.

[0117] In the tenth embodiment, in the method according to the ninth embodiment, in the alkenyl, aryl functionalized polyorganosiloxane resin-linear copolymer of (A), each R 1 It is vinyl, each R 2 It is methyl, each R 3 It is methyl, and each R 4 It is a phenyl group.

[0118] In the eleventh embodiment, in the method according to any one of the first to tenth embodiments, the alkenyl, aryl functional resin-linear polyorganosiloxane block copolymer (A) has a Mw of 20,000 g / mol to 500,000 g / mol and an alkenyl content of 0.5 mol% to 5 mol%.

[0119] In the twelfth embodiment, in the method according to any one of the first to eleventh embodiments, in the alkenyl, aryl functional resin-linear polyorganosiloxane block copolymer of (A), each nonlinear block has a number average molecular weight of 500 g / mol to 4,000 g / mol.

[0120] In the thirteenth embodiment, in the method according to any one of the first to twelfth embodiments, the organic thiol-functionalized crosslinking agent (B) is selected from compounds having formula (BI), compounds having formula (B-II), and combinations thereof, wherein:

[0121] Formula (BI) is R' m CX (4-m) ,in

[0122] The subscript m is an integer with a value of 2, 3, or 4;

[0123] Each R' is an independently chosen alkyl group having 1 to 20 carbon atoms.

[0124] Each X' is an expression The thiol functional group,

[0125] Where the subscript p is an integer with a value of 0 or 1; and

[0126] Equation (B-II) is X'-R''-X', where

[0127] R'' is an alkylene group having 1 to 20 carbon atoms, and

[0128] Each X' is selected from... or The thiol functional group of the formula

[0129] The subscript p is an integer with a value of 0 or 1.

[0130] In the fourteenth embodiment, in the method according to any one of the first to thirteenth embodiments, the organic thiol functional crosslinking agent (B) is selected from the group consisting of: 3,6-dioxa-1,8-octanedithiol; trimethylolpropane tris(3-mercaptopropionate); pentaerythritol tetra(3-mercaptopropionate); and combinations of two or more of them.

[0131] In the fifteenth embodiment, in the method according to any one of the first to fourteenth embodiments, the photoradical initiator of (C) is selected from the group consisting of: 2,4,6-trimethylbenzoyl-diphenylphosphine oxide; ethyl (2,4,6-trimethylbenzoyl)phenylphosphine ester; and combinations thereof.

[0132] In the sixteenth embodiment, an article is prepared by a method according to any one of the first to fourteenth embodiments.

[0133] In the seventeenth embodiment, the article of manufacture according to the sixteenth embodiment includes an encapsulant covering an LED on a substrate.

Claims

1. A radiation-curable polyorganosiloxane resin-linear copolymer composition, said composition comprising: 85 to 99 parts by weight of (A) alkenyl, aryl functionalized polyorganosiloxane resin-linear block copolymer, wherein The alkenyl and aryl functionalized polyorganosiloxane resin-linear block copolymer comprises linear and nonlinear blocks, wherein... Each linear block independently contains 10 to 500 formulas (R). 2 R 3 SiO 2 / 2 The dimethylsilyloxy unit of ) wherein each R 2 and each R 3 It is a monovalent hydrocarbon group consisting of 1 to 30 carbon atoms, chosen independently; Each nonlinear block has a number-average molecular weight of at least 500 g / mol, the nonlinear block comprising a trimethylsilyloxy unit and a hydrolyzable group, and wherein the nonlinear block further comprises an alkenyl group bonded to a silicon atom and an aryl group bonded to a silicon atom. At least 30 mol% of the nonlinear blocks are cross-linked with each other; Each linear segment is connected to at least one nonlinear segment, and The copolymer has a weight-average molecular weight of at least 20,000 g / mol as measured by gel permeation chromatography. 0.5 to 14.9 parts by weight of an (B) organic thiol-functionalized crosslinking agent having at least two thiol functional groups per molecule; and 0.1 to 10 parts by weight of (C) photoinitiator.

2. The composition according to claim 1, further comprising additional starting materials selected from the group consisting of: (D) stabilizers, (E) adhesion promoters, (F) solvents, and combinations of two or more thereof.

3. The composition according to claim 1 or claim 2, wherein each linear segment is transmitted via formula Partially connected to at least one nonlinear block in the alkenyl, aryl-functionalized polyorganosiloxane resin-linear block copolymer of (A), wherein each dashed line represents a covalent bond with another silicon atom in the molecule; R 1 It is an alkenyl group with 2 to 20 carbon atoms, each R 2 It is an alkyl group with 1 to 20 carbon atoms, each R 3 It is an alkyl group with 1 to 20 carbon atoms, chosen independently, and R 4 It is an aryl group with 6 to 20 carbon atoms.

4. The composition according to any one of claims 1 to 3, wherein the alkenyl, aryl functional resin-linear polyorganosiloxane block copolymer of (A) has a Mw of 20,000 g / mol to 500,000 g / mol and an alkenyl content of 0.5 mol% to 5 mol%; and in the alkenyl, aryl functional resin-linear polyorganosiloxane block copolymer of (A), each nonlinear block has a number average molecular weight of 500 g / mol to 4,000 g / mol.

5. The composition according to claim 3, wherein each R 1 It is vinyl, each R 2 It is methyl, each R 3 It is methyl, and each R 4 It is a phenyl group.

6. The composition according to any one of claims 1 to 5, wherein the organic thiol-functionalized crosslinking agent (B) is selected from compounds having formula (BI), compounds having formula (B-II), and combinations thereof, wherein: Formula (BI) is R' m CX (4-m) ,in The subscript m is an integer with a value of 2, 3, or 4; Each R' is an independently chosen alkyl group having 1 to 20 carbon atoms. Each X' is an expression The thiol functional group, Where the subscript p is an integer with a value of 0 or 1; and Equation (B-II) is X'-R''-X', where R'' is an alkylene group having 1 to 20 carbon atoms, and Each X' is selected from... or The thiol functional group of the formula The subscript p is an integer with a value of 0 or 1.

7. The composition according to claim 6, wherein the organic thiol functional crosslinker (B) is selected from the group consisting of: 3,6-dioxa-1,8-octanedithiol; trimethylolpropane tris(3-mercaptopropionate); pentaerythritol tetra(3-mercaptopropionate); and combinations of two or more thereof.

8. The composition according to any one of claims 1 to 7, wherein the photoradical initiator of (C) is selected from the group consisting of: 2,4,6-trimethylbenzoyl-diphenylphosphine oxide; ethyl (2,4,6-trimethylbenzoyl)phenylphosphine ester; and combinations thereof.

9. A packaging method, wherein the method includes: 1) Heating the composition according to any one of claims 1 to 8, thereby forming a flowable composition. 2) Forming the flowable composition on a substrate, and 3) Irradiate the composition with ultraviolet radiation, thereby curing the composition to form an encapsulant on the substrate.

10. The method of claim 9, further comprising producing a film of the composition prior to step 1).

11. The method according to claim 9 or claim 10, wherein step 2) comprises vacuum lamination.

12. The method according to any one of claims 9 to 11, wherein the substrate comprises a light-emitting diode.

13. The method according to any one of claims 9 to 12, wherein all steps of the method are performed at a temperature ≤ 80°C.

14. An article of manufacture prepared by the method according to any one of claims 9 to 13.

15. An article comprising at least a portion of an encapsulation substrate of the composition according to any one of claims 1 to 8.

Images