Radiation curable silicone – (METH)acrylate composition and methods for the preparation and use thereof

Abstract

A radiation curable, silicone – (meth)acrylate composition includes a bis-hydroxyl-terminated polydiorganosiloxane, a silsesquioxane resin, a hydroxyl-functional (meth)acrylate monomer, an alkyl (meth)acrylate monomer, a multifunctional (meth)acrylate crosslinker, and a photoradical initiator. The composition has a low viscosity, and the composition may be used in inkjet printing processes and equipment. The composition is curable to form a low modulus optically clear adhesive.

Description

RADIATION CURABLE SILICONE - (METH)ACRYLATE COMPOSITION ANDMETHODS FOR THE PREPARATION AND USE THEREOFCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Patent Application Serial No. 63 / 566,431 filed on 18 March 2024 under 35 U.S.C. §119 (e). U.S. Provisional Patent Application Serial No. 63 / 566,431 is hereby incorporated by reference.TECHNICAL FIELD

[0002] This invention relates to a radiation curable, silicone - (meth)acrylate composition and methods for the preparation and use thereof. More particularly, the radiation curable, silicone - (meth) aery late composition may be suitable for use in inkjet printing processes and equipment, and the radiation curable, silicone - (meth)acrylate composition may cure to form an optically clear adhesive.INTRODUCTION

[0003] To fabricate optoelectronic devices such as liquid crystal displays (LCDs) and organic light emitting devices (OLEDs), various types of adhesives haven been used to attach two different layers or display parts for optical bonding applications. In this field, a dry lamination method using pressure sensitive adhesive sheets has been widely applied. In addition, a dispensing method by using liquid curable adhesives is also common technology to form a layer on a target substrate. However, these methods have limitations to fabricating thinner optoelectronic devices because of difficulties in achieving layers less than 50 pm thick, as well as difficulties in forming specific shapes or patterns on substrates.

[0004] The inkjet printing process has many advantages such as formation of thin layers and fine patterns, e.g., with ability to control thickness under 50 pm, and drawing on a curved surface portion. Recently, inkjet printing technology is considered as an attractive method to directly deposit thin film layers in the fabrication of optoelectronic devices such as OLEDs. Therefore, there is an industry need for compositions suitable to form thin adhesive layers with fine patterns.SUMMARY

[0005] A radiation curable, silicone - (meth)acrylate curable composition (composition) comprises (A) a bis-hydroxyl-terminated polydiorganosiloxane, (B) an aryl-functional silsesquioxane resin, (C) a monofunctional (meth)acrylate containing a hydroxyl group, (D) a monofunctional (meth)acrylate containing an alkyl group and that is free of hydroxyl groups; (E) a multifunctional (meth)acrylate; and (F) is a photoradical initiator. The composition is useful in a process for adhering a first object and a second object.DETAILED DESCRIPTION

[0006] More particularly, the radiation curable, silicone - (meth)acrylate curable composition introduced above comprises starting materials (A), (B), (C), (D), (E), and (F), wherein: starting material (A) is a bis-hydroxyl-terminated polydiorganosiloxane comprising unit formula (I): (R12(OH)SiOi / 2)m(R1R2(OH)SiOi / 2)n(R12SiO2 / 2)o(R1R2SiO2 / 2)P, wherein each OH is a silicon-bonded hydroxyl group; each R1is independently selected from an alkyl group or an aryl group; each R2is an independently selected alkenyl group; subscripts m, n, o and p represent average numbers of each unit in the unit formula (I) and have values such that m > 0, n > 0, a quantity (m + n) > 2; o > 0, p > 0,0 < (p / (o + p)) < 1 ; and a quantity (o + p) is 1 to 1,000; starting material (B) is an aryl- functional silsesquioxane resin comprising at least 60 mole-percent trifunctional siloxane units of formula (R'SiCLc) wherein R1is as described above, and in the trifunctional siloxy units said resin has a molar ratio of alkyl groups to aryl groups (alkyl / aryl ratio) of 0 / 15 to 4 / 1; wherein starting materials (A) and (B) combined are present in an amount of 100 weight parts, and a mass ratio of starting material (A) to starting material (B) (i.e., the (A) / (B) ratio) is 0.1 / 1 to 15 / 1; starting material (C) is a monofunctional (meth) acrylate containing a hydroxyl group, wherein starting material (C) is present in an amount of 10 to 200 weight parts, per 100 weight parts of starting materials (A) and (B) combined; starting material (D) is a monofunctional (meth)acrylate containing an alkyl group and that is free of hydroxyl groups; wherein starting material (D) is present in an amount of 20 to 800 weight parts, per 100 weight parts of starting materials (A) and (B) combined; wherein starting materials (C) and (D) combined are present in an amount of 40 to 900 weight parts, per 100 weight parts of starting materials (A) and (B) combined; starting material (E) is a multifunctional (meth)acrylate; wherein starting material (E) is present in an amount of 0. 1 to 7 weight parts, per100 weight parts of starting materials (A) and (B) combined; starting material (F) is a photoradical initiator; wherein starting material (F) is present in an amount of 0.1 to 7 weight parts, per 100 weight parts of starting materials (A) and (B) combined.(A) Bis-hydroxyl-terminated polydiorganosiloxane

[0007] Starting material (A) in the composition is the bis-hydroxyl-terminated polydiorganosiloxane. Starting material (A) comprises unit formula (I): (R12(OH)SiOi / 2)m(R1R2(OH)SiOi / 2)n(R12SiO2 / 2)o(R1R2SiO2 / 2)p, wherein each OH is a silicon- bonded hydroxyl group; each R1is independently selected from an alkyl group or an aryl group; each R2is an independently selected alkenyl group; subscripts m, n, o, and p represent average numbers of each unit in the unit formula (I) and have values such that m > 0, n > 0, a quantity (m + n) > 2; o > 0, p > 0, 0 < (p / (o + p)) < 1 ; and a quantity (o + p) is 1 to 1 ,000.

[0008] In unit formula (I), suitable aryl groups for R1may be monocyclic or polycyclic and are exemplified by phenyl, naphthyl, and anthryl. Alternatively, the aryl group for R1may be phenyl. Suitable alkyl groups for R1are exemplified by methyl, ethyl, propyl (including n-propyl and isopropyl), butyl (including n-butyl, t-butyl, sec-butyl, and isobutyl), and pentyl, hexyl, heptyl, octyl, nonyl, and decyl (including branched and linear alkyl groups of 5 to 10 carbon atoms). Alternatively, the alkyl group for R1may be selected from the group consisting of methyl, propyl, and octyl; alternatively methyl, n-propyl, and n-octyl.

[0009] In unit formula (I), R2is an alkenyl group. Suitable alkenyl groups may have terminal aliphatic unsaturation. The alkenyl group for R2is exemplified by vinyl, allyl, and hexenyl; alternatively vinyl.

[0010] In unit formula (I), subscripts m and n represent numbers of terminal siloxane units. Subscripts m and n have values such that m > 0, n > 0, a quantity (m + n) > 2. One skilled in the art would recognize that starting material (A) is substantially linear or linear. For example, starting material (A) may comprise the units shown in unit formula (I) and may further comprise a small amount of T units and / or Q units, if starting material (A) has any branching.Alternatively, the quantity (m + n) = 2, when the polydiorganosiloxane is linear.

[0011] In unit formula (I), subscripts o and p represent average numbers of difunctional siloxy units per molecule. Subscripts o and p have values such that o > 0, p > 0, 0 < (p / (o + p)) < 1 , and the quantity (o + p) is 1 to 1,000. Alternatively, the quantity (o + p) may be up to 1,000, alternatively up to 500, alternatively up to 400, alternatively up to 300, alternatively up to 200, alternatively up to 100, alternatively up to 50, alternatively up to 20, and alternatively up to 10; while at the same time the quantity (o + p) is at least 1 , alternatively at least 2, alternatively at least 3, alternatively at least 4, alternatively at least 5, alternatively at least 6, alternatively atleast 7, and alternatively at least 8. The expression p / (o + p) may be equal to or above 0 and is less than 1. Alternatively, the expression p / (o + p) may be less than 0.9, alternatively, less than 0.7, alternatively, less than 0.5, and alternatively less than 0.4; while at the same time the expression p / (o + p) is greater than or equal to 0, alternatively greater than 0.35, alternatively greater than 0.2, and alternatively greater than 0.1. Alternatively, the expression p / (o + p) may be equal to 0. Without wishing to be bound by theory, it is thought that if the expression (p / (o + p)) is within the range described above, a cured product obtained by curing the composition will be suitable for use as an optically clear adhesive, i.e., said cured product will have transparency (at least 98%) with peel adhesion force > 100 gf / inch, when tested according to the test methods described below. Without wishing to be bound by theory, it is thought that if the expression (p / (o + p)) is equal to 1, a cured product obtained by curing the composition may have lower transparency and adhesion force than desirable for the present application.

[0012] Molecular weight of starting material (A) is not limited, however, molecular weight may be < 10,000 g / mol, alternatively < 5,000 g / mol. Viscosity of starting material (A) is not limited, however, it may have a viscosity < 1,000 mPa s, alternatively < 800 mPa s, or alternatively < 600 mPa s, where viscosity is measured using a type B viscometer according to ASTM D 1084 at 23 + 2 °C. Refractive index of starting material (A) is not specifically restricted, however, to prepare an optically clear adhesive by curing the composition, refractive index of starting material may be greater than or equal to 1.4.

[0013] Starting material (A) may comprise a hydroxyl-functional polydiorganosiloxane such as a-i) bis-hydroxyl-terminated poly(dimethylsiloxane), a-ii) bis-hydroxyl-terminated poly(methylphenylsiloxane), a-iii) bis-hydroxyl-terminated poly(dimethylsiloxane / diphenylsiloxane) copolymer, a-iv) bis-hydroxyl-terminated poly(dimethylsiloxane / methylphenylsiloxane) copolymer, a-v) bis-hydroxyl-terminated poly(diphenylsiloxane), a-vii) bis-hydroxyl-terminated poly(dimethylsiloxane / methylvinylsiloxane) copolymer, and a-viii) a combination of two or more of a-i) to a-vi). Alternatively, starting material (A) may be selected from the group consisting of a-i), a-ii), a-iii), a-iv), a-v), and a combination of two or more thereof.Alternatively, starting material (A) may be selected from the group consisting of a-ii), a-iii), a- iv), a-v), and a combination of two or more thereof.

[0014] Bis-hydroxyl-terminated polydiorganosiloxanes are known in the art and may be made by known methods, such as those disclosed in US Patent 2779776 to Hyde et al. Suitable, nonlimiting, commercially available bis-hydroxyl-terminated polydiorganosiloxanes useful as starting material (A) include: DMS-S14, DMS-S15, DMS-S21, DMS-S27, DMS-S31, DMS- S32, DMS-S33, DMS-S35, DMS-S42, DMS-S45, DMS-S51, PDS-0338, PDS-9931, PDS-1615,VDS-1013 (all from Gelest Inc. of Morrisville, Pennsylvania, USA).(B) Silsesquioxane Resin

[0015] Starting Material (B) in the composition is an aryl-functional silsesquioxane resin. The aryl-functional silsesquioxane resin comprises at least 60 mol % of T units of formula (R'SiChc), wherein each R1is independently selected from an alkyl group or an aryl group as described and exemplified above, with the proviso that in unit formula (II) at least one instance of R1is an aryl group (i.e., such that the silsesquioxane resin is aryl-functional). Starting material (B) has a molar ratio of alkyl groups to aryl groups (alkyl / aryl ratio) of R1in the T units of at least 0.15 / 1, alternatively at least 0.2 / 1, alternatively at least 0.25 / 1, alternatively at least 0.3 / 1, alternatively at least 0.35 / 1, and alternatively at least 0.4 / 1; while at the same time the alkyl / aryl ratio may be up to 4 / 1 , alternatively up to 3 / 1 , alternatively up to 2 / 1 . Alternatively, the alkyl / aryl ratio may be 0.15 / 1 to 4 / 1, alternatively 0.2 / 1 to 2 / 1, and alternatively 0.4 / 1 to 2 / 1.

[0016] Starting Material (B) is semisolid or solid at room temperature. Weight average molecular weight (Mw) of starting material (B) is not specifically limited. However, starting material (B) may have a Mw of 1,000 g / mol to 10,000 g / mol, or alternatively 1,500 g / mol to 8,000 g / mol, measured by GPC, using the test method described below.

[0017] One skilled in the art recognizes that silsesquioxane resins containing such high amounts of (R'SiOv:) siloxy units as described above will inherently have a certain concentration of hydrolyzable groups of formula (ZO1 / 2) where Z may be hydrogen (i.e., wherein ZO 1 / 2 represents a silanol group) or an alkyl group (so that ZO1 / 2 is a silicon bonded alkoxy group) as described above. The (ZO1 / 2) content as a mole percentage of all siloxy groups present on the organosiloxane resin may be readily determined by29Si NMR. The concentration of the (ZO1 / 2) groups present on (B) the silsesquioxane resin will vary, as dependent on the mode of preparation, and subsequent treatment of (B) the silsesquioxane resin. Typically, (B) the silsesquioxane resin suitable for use herein will have a silanol content of at least 0.1 mole %, alternatively of at least 1 mole %, alternatively at least 5 mole %, alternatively up to 10 mole %, or alternatively at least 20 mole %. Alternatively, the silsesquioxane resin may have a silanol weight % of at least 0.1 %, alternatively of at least 1 %, alternatively 5 %, alternatively 10 %, or alternatively at least 20 %.

[0018] Alternatively, starting material (B) may comprise average unit formula (II): MaDbTcQd(ZOi / 2)e, wherein M represents a monofunctional siloxane unit of formula (R SiOifi); D represents a difunctional siloxane unit of formula (R^SiChc); T represents a trifunctional siloxane unit of formula (R Si O3 / 2): wherein R1is as described above; Q represents a quadrifunctional siloxane unit of formula (SiOd / ); subscript a is a molar ratio of M siloxane units relative to moles of all siloxane units per molecule and has an average value of zero to0.35; subscript b is a molar ratio of D siloxane units relative to moles of all siloxane units per molecule and has an average value of zero to 0.35; subscript c is a molar ratio of T siloxane units relative to moles of all siloxane units per molecule and has an average value of 0.60 to 1.00; subscript d is a molar ratio of Q siloxane units relative to moles of all siloxane units per molecule and has an average value of zero to 0.50; a quantity (a+b+c+d) is equal to 1.00; a ratio of subscripts a / c is zero to 0.5; a ratio of subscripts b / c is zero to 0.5; a ratio of subscript d / c is zero to 0.8; each Z is independently selected from H and an alkyl group; subscript e is a molar amount of silicon bonded hydrolyzable groups of formula ZO1 / 2 in starting material (B), and subscript e has a value sufficient to provide a concentration of the hydrolyzable groups of zero to 100 mole-percent based on moles of starting material (B). Alternatively each Z may be selected from H and methyl. Alternatively, each Z may be H. Alternatively, subscript a may have an average value of 0 or more, alternatively 0.10 or more, alternatively 0.15 or more, alternatively 0.20 or more, and alternatively 0.25 or more, while at the same time subscript a may have an average value of 0.35 or less, and alternatively 0.30 or less, alternatively 0.28 or less, alternatively 0.25 or less, alternatively 0.20 or less, and alternatively 0.15 or less. Alternatively, subscript b may have an average value of 0 or more, alternatively 0.10 or more, alternatively 0.15 or more, alternatively 0.20 or more, and alternatively 0.25 or more, while at the same time subscript b may have an average value of 0.35 or less, alternatively 0.30 or less, alternatively 0.25 or less, alternatively 0.20 or less, and alternatively 0.15 or less. Alternatively, subscript c may have a value of 0.60 or more, alternatively 0.70 or more, alternatively 0.80 or more, alternatively 0.90 or more, and alternatively 0.95 or more, while at the same time subscript c may have a value of 1.00 or less, alternatively 0.95 or less, alternatively 0.90 or less, alternatively 0.80 or less, and alternatively 0.70 or less. Alternatively, subscript d may have a value of zero or more, alternatively 0.10 or more, alternatively 0.15 or more, alternatively 0.20 or more, alternatively 0.25 or more, alternatively 0.30 or more, and alternatively 0.35 or more while at the same time subscript d may have an average value of 0.50 or less, alternatively 0.40 or less, alternatively 0.30 or less, alternatively 0.25 or less, alternatively 0.20 or less, and alternatively 0.15 or less.

[0019] Examples of unit formulas for starting material (B) include: i) TPho.7TPro.3(HOi / 2)o.36 (which has an Alkyl / Aryl ratio in the T units = 0.43 / 1 and Mw = 2,900 g / mol); ii) DMe2o.29TMeo.32TPho.39(HOi / 2)o.2 (which has T unit mole% = 71 %, Alkyl / Aryl ratio in the T units = 0.82 / 1, and Mw = 3,000 g / mol); iii) DMe2o.i5TMeo.4oTPho.45(HOi / 2)o,38 (which has T unit mole % = 85 %, Alkyl / Aryl ratio in the T units = 0.89 / 1, and Mw = 3,055 g / mol);iv) DMe2o.o5TMeo.47TPho.48(HOi / 2)o.4 (which has T unit mole% = 95 %, Alkyl I Aryl ratio in the T units = 0.98 / 1, and Mw = 4,300 g / mol); and v) DPhMeo.osDPh2o.ioTMeo.45TPho.4o(HO 1 / 2)0.46 (which has T unit mole% = 85 %, Alkyl I Aryl ratio in the T units = 1.13 / 1, and Mw = 2,500 g / mol).Alternatively, starting material (B) may have unit formula i), above.

[0020] Silsesquioxane resins containing at least 60 mol % of (R'SiCh / ?) siloxy units, and methods for preparing them, are known in the art. They are typically prepared by hydrolyzing an organosilane with substituents such as a halogen or alkoxy group in an organic solvent. A representative example for the preparation of a silsesquioxane resin may be found in US Patent 5075103. Furthermore, many silsesquioxane resins are available commercially and sold either as a solid (flake or powder), or dissolved in an organic solvent. Suitable, non-limiting, commercially available silsesquioxane resins useful as starting material (B) include DOWSIL™ RSN-0233 Flake Resin, RSN-0249 Flake Resin, RSN-0255 Flake Resin, RSN-6018 Resin Intermediate, all of which are available from The Dow Chemical Company of Midland, Michigan, USA; and SILRES™ SY 300, REN 168, and 604, which are available from Wacker. Additional silsesquioxane resins suitable for use herein are disclosed in PCT Patent Publication WO2024039544.

[0021] The weight ratio of starting material (A) I starting materials (B) (i.e., the (A) / (B) ratio) may be 0.1 / 1 to 15 / 1. Alternatively, (A) / (B) ratio may be 0.2 / 1 to 14 / 1, alternatively, 0.3 / 1 to 13 / 1. Without wishing to be bound by theory, it is thought that when the weight ratio of starting material (A) I starting material (B) is less than or equal to the lower limit of the range described above, a cured product of the composition may have undesirably high modulus at low temperature (e.g., modulus over 5 MPa at -20 °C), however, when the (A) / (B) ratio is higher than the upper limit of the range described above, the cured product of the composition may not have proper adhesion force to be useful as an adhesive.(C) Monofunctional (meth)acrylate containing a hydroxyl group

[0022] Starting material (C) in the composition is a monofunctional (meth)acrylate containing a hydroxyl group. Starting material (C) may be a hydroxy- substituted alkyl (meth)acrylate monomer. Starting material (C) may have formulawherein R3is H or a methyl group, and D1is an alkane-diyl group. When R3is H, starting material (C) is an acrylate. When R3is methyl, starting material (C) is a methacrylate.Alternatively, each R3may be H. D1may have 2 to 6, alternatively 2 to 4 carbon atoms. Suitable monofunctional (meth) acrylates that contain a hydroxyl group are known in the art and are commercially available. For example, hydroxyethyl acrylate (CAS# 818-61-1), hydroxypropyl acrylate (CAS# 25584-83-2), and hydroxybutyl acrylate (CAS# 2478-10-6) are each available from Sigma Aldrich Inc. of St. Louis, Missouri, USA. Alternatively, starting material (C) may comprise hydroxypropyl acrylate. Alternatively, starting material (C) may be hydroxypropyl acrylate. Starting material (C) is used in the composition in an amount of 10 parts to 200 parts, per 100 parts of starting materials (A) and (B) combined. Alternatively, the amount of starting material (C) may be at least 15 parts, alternatively at least 20 parts, alternatively at least 23 parts, alternatively at least 30 parts, alternatively at least 33 parts, alternatively at least 35 parts, alternatively at least 37 parts, and alternatively at least 40 parts; while at the same time the amount of starting material (C) may be up to 200 parts, alternatively up to 190 parts, alternatively up to 180 parts, alternatively up to 175 parts, alternatively up to 167 parts, and alternatively up to 150 parts, on the same basis. Alternatively, the composition may contain 15 parts to 190 parts, alternatively 20 parts to 180 parts, of starting material (C) on the same basis.(D) Monofunctional (meth)acrylate free of hydroxyl groups

[0023] Starting material (D) in the composition is a monofunctional (meth)acrylate containing an alkyl group and that is free of hydroxyl groups. Starting material (D) may have formula (IV):, wherein R is H or methyl as described above, and R4is an alkyl group with 3 to 30 carbon atoms. Suitable alkyl groups for R4may have at least 3, alternatively at least 4, carbon atoms, and may have up to 30, alternatively up to 20, and alternatively up to 16, carbon atoms. Examples of monofunctional (meth)acrylates suitable for use herein include butyl acrylate (CAS# 141-32-2), isobutyl acrylate (CAS# 106-63-8), n-hexyl acrylate (CAS# 2499-95-8), 2-ethylhexyl acrylate (CAS# 103-11-7), n-heptyl acrylate (CAS# 2499-95-8), 2- methylheptylacrylate (CAS# 29590-42-9), octyl acrylate (CAS# 2499-59-4), isooctyl acrylate (CAS# 29590-42-9), nonyl acrylate (CAS# 2664-55-3), nonyl methacrylate (CAS# 2696-43-7), isononyl acrylate (CAS# 51952-49-9), decyl acrylate (CAS# 2156-96-9), laurayl acrylate (CAS# 2156-97-0), tetradecyl acrylate (CAS# 21643-42-5), cetyl acrylate (CAS# 13402-02-3, 4813-57- 4), stearyl acrylate (CAS# 4813-57-4), and isostearyl acrylate (CAS# 93841-48-6). Starting material (D) is used in the composition in an amount of 20 parts to 800 parts of starting material(D), per 100 parts starting materials (A) and (B) combined. Alternatively, the composition may comprise at least 25 parts, alternatively at least 29 parts, alternatively 50 parts, alternatively at least 100 parts, alternatively at least 110 parts of starting material (D); while at the same time the composition may comprise up to 750 parts, alternatively up to 740 parts, alternatively up to 700 parts, alternatively up to 650 parts, alternatively up to 600 parts, alternatively up to 550 parts of starting material (D) on the same basis. Alternatively, the composition may comprise 22 parts to 770 parts, alternatively 25 parts to 750 parts, of starting material (D) on the same basis.

[0024] The composition comprises starting materials (C) and (D) combined in an amount of 40 parts to 900 parts per 100 parts of starting materials (A) and (B) combined. Alternatively starting materials (C) and (D) may be used in a combined amount of 45 parts to 895 parts, and alternatively 50 parts to 890 parts on the same basis. Without wishing to be bound by theory, it is thought that when the content of starting materials (C) and (D) combined is greater than the upper limit of the range described above, viscosity may be too low and the composition may not be suitable for use in an inkjet printing process, however, when the content of starting materials (C) and (D) combined is less than the lower limit of the range described above, viscosity of the composition could be too high, and the composition may be unsuitable for use in an inkjet process.(E) Multifunctional (meth)acrylate crosslinker

[0025] Starting material (E) is a multifunctional (meth)acrylate, which may serve as a crosslinker in the composition. Starting material (E) has at least two (meth)acryl-functional groups per molecule, alternatively two to three (meth)acryl-functional groups per molecule. Without wishing to be bound by theory, it is thought that starting material (E) will impart high temperature stability to the cured product of the composition via crosslinking the composition. Suitable difunctional (meth)acrylates for use herein may have formula (V):, wherein each R3is independently selected from H and methyl, and D2is an alkane-diyl group of 2 to 30 carbon atoms. Alternatively, each R3in formula (V) may be H. Alternatively, D2may have 4 to 20, alternatively 6 to 10 carbon atoms. Examples of the multifunctional (meth)acrylate crosslinker include 1 ,6-hexanediol diacrylate (CAS# 13048-33-4), 1 ,9-nonanediol diacrylate (CAS# 107481-28-7), 1,10-decanediol diacrylate (CAS# 13048-34-5), trimethylolpropane triacrylate (CAS# 15625-89-5), propoxylated trimethylolpropane triacrylate (CAS# 53879-54-2), and a combination of two or more thereof.Suitable multifunctional (meth) acrylate crosslinkers are known in the art and are commercially available from various sources including Sigma Aldrich, Inc. and BOC Sciences.

[0026] The composition comprises starting material (E) in an amount of 0.1 part to 7 parts, per 100 parts of starting materials (A) and (B) combined. Without wishing to be bound by theory, it is thought that if the amount of starting material (E) is above 7 parts (on the same basis), then the cured product of the composition may be undesirably brittle, however, if the amount of starting material (E) is less than 0.1 part (on the same basis above) then the cured product of the composition may have insufficient high temperature stability. Alternatively, starting material (E) may be used in an amount of at least 0.1 part, alternatively at least 0.2 part, alternatively at least 0.3 part, alternatively at least 0.5 part, alternatively at least 0.75 part, alternatively at least 1 part, alternatively at least 1.25 parts of starting material (E), while at the same time the amount may be up to 7 parts, alternatively up to 6 parts, alternatively up to 5 parts, alternatively up to 4 parts, alternatively up to 3.5 parts, and alternatively up to 3.33 parts of starting material (E) on the same basis. Alternatively, the composition may comprise 0.2 part to 6 parts of starting material (E), and alternatively 0.5 part to 5 parts, on the same basis.(F) Photoradical initiator

[0027] Starting material (F) in the composition is a photoradical initiator. Suitable photoradical initiators include ultraviolet (UV) initiators such 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- azido benzylidene)cyclohexanone; 2,6-bis(4-azido benzylidene)-4-methylcyclohexanone; 1- hydroxy-cyclohexyl-phenyl-ketone (CAS# 947-19-3, available under the name OMNIRAD™ 184); 2-methyl-l-[4-(methylthio)phenyl]-2-morpholinopropane-l-one (CAS# 718-10-5, available under the name OMNIRAD™ 907); 2-hydroxy-2-methyl-l-phenyl-propane-l-one (CAS# 7473-98-5, available under the name OMNIRAD™ 1173); a mixed initiator of 50% benzophenone (CAS# 119-61-9) and 50% of OMNIRAD™ 184C (the mixed initiator available under the name OMNIRAD™ 500); a mixed initiator of 20% of OMNIRAD™ 184C and 80% of OMNIRAD™ 1173 (the mixed initiator available under the name OMNIRAD™ 1000); l-[4- (2-hydroxyethoxyl)-phenyl]-2-hydroxy-2-methylpropanone (CAS# 106797-53-9 available under the name OMNIRAD™ 2959); methylbenzoylformate (CAS# 152-55-0, available under the name OMNIRAD™ MBF); 2,2-dimethoxy-2-phenylacetophenone (CAS# 24650-42-8, available under the name OMNIRAD™ BDK); 2-benzyl-2-(dimethylamino)-4’- morpholinobutyrophenone (CAS# 119313-12-1 available under the name OMNIRAD™ 369); diphenyl (2,4,6-trimethylbenzoyl)phosphine oxide (CAS# 75980-60-8, available under the name OMNIRAD™ TPO); ethyl (2,4,6-trimethylbenzoyl) phenyl phosphinate (CAS# 84434-11-7,available under the name OMNIRAD™ TPO-L); and a combination of two or more thereof. The photoradical initiators with the OMNIRAD™ brands are commercially available from IGM Resins B.V., Netherland. Other photoradical initiators are commercially available from other sources, and are as described, for example in PCT Patent Publication WO2024039544 and US Patent 11827799.

[0028] The amount of photoradical initiator in the composition will depend on various factors including the desired reaction rate, the photoradical initiator used, and the selections and amounts of starting material (A) to (E), however, the amount of photoradical initiator may be 0.1 part to 7 parts, per 100 parts of starting materials (A) and (B) combined. Alternatively, the amount of the photoradical initiator may be at least 0.05 part, alternatively at least 0.1 part, and alternatively at least 0.4 parts on the same basis; while at the same time, the amount of photoradical initiator may be up to 7 parts, alternatively up to 5 parts, alternatively up to 1 parts, alternatively up to 0.7 parts, on the same basis. Alternatively, starting material (F) may be used in an amount of at least 0. 1 part, alternatively at least 0.2 part, alternatively at least 0.3 part, alternatively at least 0.5 part, alternatively at least 0.75 part, alternatively at least 1 part, alternatively at least 1.24 parts of starting material (F), while at the same time the amount may be up to 7 parts, alternatively up to 6 parts, alternatively up to 5 parts, alternatively up to 4 parts, alternatively up to 3.5 parts, and alternatively up to 3.33 parts of starting material (F) on the same basis.

[0029] The composition described herein may optionally further comprise an additional starting material. For example, the composition may further comprise a radical scavenger. Radical scavengers can be desirable to extend the storage stability of the composition by inhibiting curing until intentionally exposing the composition to UV light. Radical scavengers include phenolic compounds such as any one or any combination of more than one of 4- methoxyphenol (MEHQ, methyl ether of hydroquinone), hydroquinone, 2-methylhydroquinone, 2-t-butylhydroquinone, t-butyl catechol, butylated hydroxy toluene, and butylated hydroxy anisole. Other types of radical scavengers include phenothiazine and anaerobic inhibitors such as NPAL type inhibitors (tris-(N-nitroso-N-phenylhydroxylamine) aluminum salt) available from Albemarle Corporation. Alternatively, the radical scavenger may comprise a manganese ion source and a phenolic compound, e.g., particularly if the composition and / or any of starting materials (C), (D), and / or (E) will be heated under anaerobic conditions (i.e., under an atmosphere containing < 2% oxygen). 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 (11) perchlorate, hydrates thereof (e.g., manganese (II) tetrahydrate) and combinations thereof. Alternatively, the manganese ion source may comprise manganese (II) acetate or manganese (II) tetrahydrate, or a combination thereof. Suitable manganese ion sources are commercially available from Millipore Sigma of St. Louis, Missouri, USA, Fisher Scientific of Waltham, Massachusetts, USA, and City Chemical LLC of Connecticut, USA. The amount of manganese ion source depends on various factors including the selections and amounts of starting materials used in the composition, whether one or more of starting materials (C), (D) and / or (E) will be heated under anaerobic conditions, and the time and temperature for heating. However the amount of manganese ion source may be 0.1 ppm to 5,000 ppm, alternatively 0.1 ppm to 1,000 ppm, based on combined weights of all starting materials used in the composition described herein, excluding solvent, if used. Alternatively, the amount of the manganese ion source may 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 at the same time, the amount of manganese ion source may 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, on the same basis.

[0030] The phenolic compound used herein has one or more phenolic groups per molecule. Suitable phenolic compounds include hydroquinone (HQ), dihydroxybenzene (catechol), resorcinol, dihydroxyxylene, methoxyphenols such as guaiacol, p-methoxyphenol (also called methyl ether of hydroquinone or MeHQ), tert-butyl hydroquinone (tBuHQ), pyrogallol, methylpyrogallol, cresol, phenol, xylenols, and combinations thereof. Alternatively, the phenolic compound may be selected from the group consisting of HQ, MeHQ, tBuHQ, and a combination of two or more thereof. Suitable phenolic compounds are commercially available, e.g., from Millipore Sigma of St. Louis, Missouri, USA. The amount of phenolic compound source depends on various factors including the selections and amounts of other starting materials used in the composition, however the amount may be 5 ppm to 5,000 ppm based on combined weights of all starting materials used in the composition, excluding solvent, if used. Alternatively, the amount of the phenolic compound 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 compound may be up to 500 ppm, alternatively up to 400 ppm, alternatively up to 350 ppm, and alternatively up to 320 ppm, on the same basis. Alternatively, the total amount of the radical scavenger present in the composition may be at a concentration of zero mass% or more, 0.001 mass% or more, 0.01 mass% or more, even 0.5 mass% or more while at the same time is typically present at a concentration of 1.0 mass% or less and can bepresent at a concentration of 0.5 mass% or less, even 0.1 mass% or less where mass% is based on based on the combined mass of starting materials (A), (B), (C), (D), and (E).

[0031] The composition can comprise, or be free of, another optional additional additive including those selected from the group consisting of UV absorbers, antioxidants, sensitizers (for example, anthracene derivatives and acridine derivatives), and chain transfer agents. These other optional additional additives can be present at a combined concentration of zero % or more, 0.001 % or more, 0.01 % or more, even 0.5 % or more while at the same time the optional additional additive may be present at a combined concentration of 1.0 % or less, alternatively 0.5 % or less, and alternatively 0.1 % or less where this concentration is based on weights of starting materials (A), (B), (C), (D), and (E) combined.

[0032] The composition described herein can comprise or be free of plasticizers. Plasticizers are non-reactive components that lower the viscosity of the composition when added to the composition. Alternatively, the composition may be free of plasticizers. The composition may also be free of (meth)acryl-functional organosilicon compounds, such as (meth)acryloxyalkyl- terminated polyorganosiloxanes. Without wishing to be bound by theory, it is thought that the presence of (meth)acryloxyalkyl-terminated polyorganosiloxanes in the composition may result in the cured product of the composition having insufficient peel adhesion strength to be useful as an adhesive, as described herein. Alternatively, the composition described above may consist essentially of starting materials (A), (B), (C), (D), (E), and (F), as described above. Alternatively, the composition may consist of starting materials (A), (B), (C), (D), (E), and (F), as described above.Method of Making

[0033] The composition described above may be prepared by any convenient means in any convenient equipment. For example, a batch mixer equipped with an agitator and / or a baffle, and optionally with a jacket for heating and / or cooling may be used. The starting materials described above may be added in any order and mixed, optionally under anaerobic conditions and optionally with heating. Alternatively, starting material (B) the silsesquioxane resin may optionally be dissolved in one or more of starting materials (C), (D), and / or (E) before any other starting materials (e.g., starting materials (A) and (F)) are added and mixed. If starting material (B) is delivered in a solvent, such as toluene and / or xylene, the solvent may be removed (e.g., by stripping and / or distillation, optionally with reduced pressure) and the solvent may be replaced with one or more of starting materials (C), (D), and / or (E).

[0034] The composition prepared as described above may have a viscosity of 3 mPa s to 50 mPa s at 25 °C, measured according to the viscosity test method described below, even without the addition of organic solvent.Method of Use

[0035] The composition described above is curable to form an adhesive, which may be an optically clear adhesive. Therefore, this invention further comprises a process comprising: 1) applying the composition described above onto a first object, and 2) applying a second object to the composition so as to sandwich the composition between and in contact with the first and second objects. The composition described herein is UV curable. Therefore, the process described above may further comprise: 3) curing the composition between the first object and the second object by exposing the composition to ultraviolet radiation.

[0036] In step 1), the composition may be applied to the first object by any means. For example, the following devices are suitable for applying the composition onto the first object: gravure coater, offset coater, offset gravure coater, roller coater, reverse-roller coater and printing processes such as screen printing, pin transfer, stencil printing and inkjet printing. Alternatively, step 1) may comprise inkjet printing the composition onto the first object in a desirable pattern using an inkjet printer. The composition described herein may be suitable for use in inkjet printing processes and equipment.

[0037] The first object and / or second object may transmit optical light, and can be optically transparent. Desirably, at least one of the first object and the second object transmits UV radiation, and curing of the composition after applying the second object occurs by exposing the composition to UV radiation through at least one of the first object and the second object. Alternatively, the composition may be cured (or partially cured) after application to the first object in step 1) and before step 2), e.g., in a dry lamination process as described above.

[0038] Exposing the composition to UV radiation may comprise using a wavelength selected from 365 nm, 385 nm, 395 nm, 405 nm, or a combination of two or more thereof. Without wishing to be bound by theory, it is thought that using a UV light emitting diode (LED) lamp may facilitate control of the UV exposure. The UV radiation exposure dosage may be 0.1 Joules per square centimeter (J / cm2) or more, alternatively 1.0 J / cm2or more, while at the same time, exposure dosage may be 200 J / cm2or less, and alternatively 100 J / cm2or less. UV exposure of the composition to cure the composition can occur in air. However, oxygen can inhibit curing so UV exposure may alternatively occur under anaerobic conditions, e.g., under an inert gas such as nitrogen or carbon dioxide, in which no more than 2% oxygen is present.

[0039] The composition described herein may be used, for example, instead of the curable compositions described in US Patent 8174000; US Patent Publication US20190292394; European Patent Publication EP39O4411(A1); and PCT Patent Publications W02020066602, WO2022137064, and WO2024039544.EXAMPLES

[0040] The following examples are provided to illustrate the invention to one skilled in the art and are not to be construed as limiting the scope of the invention set forth in the claims. Starting materials used in the examples are described below in Table 1.Table 1 - Starting Materials

[0041] In this Reference Example 1, comparative starting material A’ -8 described above in Table 1 was prepared as follows: A 200 mL four- necked flask was equipped with a mechanical stirrer and thermometer. To the flask was added 40.7 g of 2-propenoic acid, 2-methyl-3-(l, 1,3,3- tetramethyldisiloxanyl)propylester (CAS#96474-12-3, from Dow Silicones Corporation of Midland, Michigan, USA), and 59.3 g divinyl-terminated polydimethylsiloxane (A’ -5) as described above in Table 1. While stirring the mixture in the flask, 0.01 g of a catalyst (platinum, l,3-diethenyl-l,l,3,3-tetramethyldisiloxane complexes) was slowly added. The resulting mixture was stirred for 2 hours at 80 °C and then cooled down, and the resulting product was amethacryloxypropyl-terminated polydimethylsiloxane (A’-8).

[0042] In this Reference Example 2, samples of curable compositions were prepared as follows: Starting material (B) may be solid or dissolved in solvents such as toluene and xylene due to high viscosity. (If the starting material (B) was provided as a solid, it was directly dissolved in starting material (C) and / or (D) to prepare a solventless composition. If starting material (B) was provided dissolved in a solvent, the solvent was evaporated and replaced with the starting material (C) and / or (D). For example, to prepare Exp. 1, firstly, 62.50 g of starting material (B-l) was dissolved in 110 g of starting material (D-l) by shaking for 1 day. Then, 37.50 g of starting material (A-l), 37.50 g of starting material (C- 1 ), 1.25 g of starting material (E-l), and 1.24 g of starting material (F-l) were added to the above mixture, and the mixture was mixed by an agitator for 10 minutes at RT. Additional samples were prepared in this manner by combining starting materials (A) to (F) in the amounts shown below in Tables 2 to 4. The samples were then evaluated according to the test methods described below.Table 2 - Comparative Examples 1 to 6Table 3 - Comparative Examples 7 to 11Table 4 - Working Examples 1 to 8

[0043] Comp. 1 did not contain starting material (A), and this resulted in a high modulus value (over 5 MPa at -20 °C) under the conditions tested. Comp. 1 and Exp. 1 show that adding starting material (A) (in Exp. 1 ) provided a benefit to reducing modulus to a desired value in the cured product of the composition, over the comparative composition (Comp. 1) as described in PCT Patent Publication WO2024039544.

[0044] Comp. 2 did not contain starting material (B), and this resulted in a low adhesion value (under 100 gf / inch) under the conditions tested. Comp. 2 and Exp. 1 showed that adding starting material (B) improved peel adhesion under the conditions tested.

[0045] Comp. 1, 2, 3, and 4 (compared to Exp. 1, 6, and 7) showed the effects of varying the weight ratio of starting material (A) to starting material (B) (i.e., the (A) / (B) ratio). In Comp. 1, with no starting material (A), the (A) / (B) ratio was 0 / 1. In Comp. 3 the (A) / (B) ratio was 0.05 / 1. The cured products formed from Comp. 1 and Comp. 3 both had overly high modulus (over 5MPa) at -20 °C. In Comp. 2, the (A) / (B) ratio was 1 / 0, and the cured product had poor adhesion force (under 100 gf / in). Without wishing to be bound by theory, it is thought that starting material (B) caused high viscosity and low adhesion values, which can be detrimental to the use of the composition in inkjet printing applications and use of the composition to form an adhesive. Accordingly, the (A) / (B) ratio is 0.1 / 1 to 15 / 1, as shown in Exp. 1 - 8 to achieve the desired combination of properties to make an inkjet printable composition capable of forming an adhesive.

[0046] Comp. 5 did not contain starting material (E), and Comp. 5 was unable to be cured.

[0047] Comp. 6 contained comparative starting material (A’ -8) instead of starting material (A) as defined for the present invention, and Comp. 6 was unable to achieve adhesion strength over 100 gf / in. In contrast, the composition of the present invention (e.g., as shown in Exp. 1) had peel adhesion of 1000 gf / in under the conditions tested. Comp. 6 showed that a composition containing an organopolysiloxane having an acryloyl group according to US Patent 11827799 produced a reaction product that had insufficient peel adhesion for the present application.Therefore, the (uncured) radiation curable, silicone - (meth) acrylate composition described herein may be free of organopolysiloxanes having silicon bonded acryloyl-functional groups.

[0048] Comp. 7 contained comparative starting material (A’ -4), which had the expression (p / (o + p)) = 1 , and this resulted in a low transmittance value in the cured product. In contrast, Exp. 4 contained starting material (A-2) according to the present invention, and starting material (A-2) had the expression (p / (o + p)) = 0.36. Comp. 7 and Exp. 4 showed that starting material (A) with the expression (p / (o + p)) < 1 is desirable to produce an optically clear adhesive product from the composition.

[0049] Comp. 8 contained comparative starting material (A’-5) instead of starting material (A) as defined for the present invention, and the resulting cured product had a low transmittance value compared to Exp. 1.

[0050] Comp. 9 contained comparative starting material (A’ -6) instead of starting material (A) as defined for the present invention, and the composition had high viscosity, which was undesirable for inkjet printing. In contrast, the composition of Exp. 1 had a viscosity suitable for inkjet printing.

[0051] Comp. 10 contained comparative starting material (A’ -7) instead of starting material (A) as defined for the present invention, and the cured product of Comp. 10 had low modulus and low adhesion values.

[0052] Comp. 11 did not contain starting material (C), and the cured product had a low adhesion value.Test Methods

[0053] Curing (appearance after cure) was evaluated as follows: After UV irradiation, a cured sample was observed by a finger. A value of ‘O’ in the tables above indicated that when the sample was pressed by a finger and detached, uncured liquid did not appear on a finger from the cured sample.

[0054] Viscosity of the compositions prepared herein was measured as follows: Viscosity was measured by AR-G2 Rheometer using a 40 mm diameter 2° cone and plate measuring system. The viscosity was measured at shear rate = 10 1 / s for 1 minutes and the temperature was controlled by a Peltier plate. The latest data was collected after measurement was completed.

[0055] Storage modulus of the cured products of the compositions described herein was evaluated as follows: Each composition was poured into a mold (thickness = 1 mm) and sandwiched between releasable films. The assembled samples were cured by using 365 nm LED lamp (FireJet™ FJ100), and the total UV dosage was 6 J / cm2. After the releasable films were removed, the sample was mounted onto a parallel-plate geometry (25 mm) of a rheometer (AtonParr™ MCR-502). Then, the shear storage modulus (G') was collected at a fixed frequency of 1 Hz with a strain of 1.0 % and a normal force of 0.5 N at -20 °C.

[0056] Transmittance of the cured products of the compositions described herein was evaluated as follows: Each composition was poured into a mold (thickness = 50 um) and sandwiched between microslide glasses (Matsunami Glass Co., Ltd, Product#9213). The assembled samples were cured in the above same manner as described above. The transmittance at 550 nm was measured by the method specified in ASTM D 1003 (UV- Visible Spectrophotometer, Konica Minolta CM-3600A, Reference material = Deionized Water).

[0057] Peel adhesion strength of the cured products of the compositions described herein was evaluated as follows: Each composition was applied as a film on a glass plate. A pre-cured adhesive layer was produced by UV irradiating, thereby forming the layer with a thickness of 40 pm. The conditions for UV irradiating from the top surface of the film were 1.5 J / cm2by 365 nm LED lamp (FireJet™ FJ100). A strip of corona- treated polyethylene terephthalate (PET) film was placed on the obtained layer and bonded thereto by moving a rubber-lined pressure roller of 2 kg weight on the strip twice back and forth. The resulting laminate was fully cured by additional UV irradiation (5 J / cm2), and aged for 1 day at RT. A layer of PET film was cut into tape strips 2.54 cm (1 inch) wide, and then the adhesion force (g / inch) required to peel the tape off from the glass plate by pulling at a speed of 5.0 mm / s and an angle of 180° was measured. The data was collected by Texture analyzer.Industrial Applicability

[0058] The radiation curable silicone - (meth)acrylate composition described herein may be suitable for inkjet printing, e.g., said composition may have a viscosity of 3 mPa s to 50 mPa sat 25 °C measured according to the test method described in the examples, above. Furthermore, the composition is curable via exposure to UV radiation to form an adhesive with an optical transmittance of 98% to 100% at 500 nm through a 1 mm thick film of the cured product of the composition, a shear storage modulus at -20 °C of greater than 0.001 MPa to less than 5 MPa at one hertz and 1% shear rate over 25 to 80 °C, and a peel adhesion > 100 gf / inch (> 38.6 N / m) from PET, when evaluated by the test methods described above.Definitions and Usage of Terms

[0059] All amounts, ratios, and percentages are by weight unless otherwise indicated by the context of the specification. The articles ‘a’, ‘an’, and ‘the’ each refer to one or more, unless otherwise indicated by the context of specification. The singular includes the plural unless otherwise indicated by the context of the specification. The SUMMARY and ABSTRACT are hereby incorporated by reference. The amounts of all starting materials in a composition total 100%. The transitional phrases “comprising”, “consisting essentially of’, and “consisting of’ are used as described in the Manual of Patent Examining Procedure Ninth Edition, Revision 08.2017, Last Revised January 2018 at section §2111.03 I., II., and III. The use of “for example,” “e.g.,” “such as,” and “including” to list illustrative examples does not limit to only the listed examples. Thus, “for example” or “such as” means “for example, but not limited to” or “such as, but not limited to” and encompasses other similar or equivalent examples. The disclosure of ranges includes the range itself and also anything subsumed therein, as well as endpoints. Similarly, the disclosure of Markush groups includes the entire group and also any individual members and subgroups subsumed therein. For example, disclosure of the Markush group a hydrogen atom, an alkyl group, an alkenyl group, or an aryl group, includes the member alkyl individually; the subgroup alkyd and aryl; and any other individual member and subgroup subsumed therein. Any feature or aspect of the invention may be used in combination with any other feature or aspect recited herein. Abbreviations are as defined below in Table 5.Table 5 - Abbreviations

[0060] Mw may be measured by GPC using a Waters 2695 Separation Module with a Waters 2487 ultraviolet (UV) detector, and using as columns three STYRAGEL™ HR columns (7.8 by 300 millimeters with a molecular weight separation range of 100 to 4,000,000) and a STYRAGEL™ protection column with THF (7.8 by 200 millimeters). STYRAGEL is a trademark of Millipore Corporation. Samples are prepared as a 0.5 mass-percent (mass%) solution in toluene and filtered through a 0.45 micrometer polytetrafluoroethylene syringe filter. This method uses a flow rate of one milliliter per minute, column and detector temperatures of 35 °C, injector volume of 100 microliters, and a running time of 60 minutes. The Mw may becalculated relative to linear polystyrene standards covering the molecular weight range of 580 g / mol to 2,610,000 g / mol.Embodiments of the Invention

[0061] In a first embodiment, a process for preparing an adhesive comprises:1) applying a radiation curable, silicone - (meth) aery late curable composition onto a first object, wherein the radiation curable, silicone - (meth) aery late curable composition comprises starting materials (A), (B), (C), (D), (E), and (F), wherein starting material (A) is a bis-hydroxyl terminated polydiorganosiloxane comprising unit formula (I) (R12(0H)Si0i / 2)m(R1R2(0H)Si0i / 2)n(R12Si02 / 2)o(R1R2Si02 / 2)p, wherein each OH is a silicon-bonded hydroxyl group; each R1is independently selected from an alkyl group or an aryl group; each R2is an independently selected alkenyl group: subscripts m, n, o and p represent average numbers of each unit in the unit formula (I) and have values such that m > 0, n > 0, a quantity (m + n) > 2; o > 0,P > 0,0 < (p / (o + p)) < 1; and a quantity (o + p) is 1 to 1,000: starting material (B) is an aryl- functional silsesquioxane resin comprising at least 60 mole-percent trifunctional siloxane units of formula (R'SiCHc) wherein R1is as described above, and in the trifunctional siloxy units said resin has a molar ratio of alkyl groups to aryl groups ) in the trifunctional siloxane units (alkyl / aryl ratio) of 0 / 15 to 4 / 1; wherein starting materials (A) and (B) combined are present in an amount of 100 weight parts, and a mass ratio of starting material (A) to starting material (B) ((A) / (B) ratio) is 0.1 / 1 to 15 / 1: starting material (C) is a monofunctional (meth)acrylate containing a hydroxyl group, wherein starting material (C) is present in an amount of 10 to 200 weightparts, per 100 weight parts of starting materials (A) and (B) combined; starting material (D) is a monofunctional (meth)acrylate containing alkyl groups that is free of hydroxyl groups; wherein starting material (D) is present in an amount of 20 to 800 weight parts, per 100 weight parts of starting materials (A) and (B) combined; wherein starting materials (C) and (D) combined are present in an amount of 40 to 900 weight parts, per 100 weight parts of starting materials (a) and (b) combined; starting material (E) is a multifunctional (meth)acrylate; wherein starting material (E) is present in an amount of 0.1 to 7 weight parts, per 100 weight parts of starting materials (A) and (B) combined; starting material (F) is a photoradical initiator; wherein starting material (F) is present in an amount of 0. 1 to 7 weight parts, per 100 weight parts of starting materials (A) and (B) combined; and2) applying a second object to the radiation curable, silicone - (meth)acrylate curable composition, so as to sandwich the radiation curable, silicone - (meth) acrylate curable composition between and in contact with the first object and the second object.

[0062] In a second embodiment, the process of the first embodiment further comprises: curing the radiation curable, silicone - (meth)acrylate curable composition by exposing the radiation curable, silicone - (meth) acrylate curable composition to ultraviolet radiation.

[0063] In a third embodiment, the process of the first embodiment or the second embodiment further comprises pre-curing the radiation curable, silicone - (meth)acrylate curable composition by exposing the radiation curable, silicone - (meth) acrylate curable composition to ultraviolet radiation after applying the radiation curable, silicone - (meth) acrylate curable composition to the first surface of the first object and before applying the second surface of the second object to the radiation curable, silicone - (meth)acrylate curable composition.

[0064] In a fourth embodiment, in any one of the first to third embodiments, step 1) is performed via inkjet printing.

[0065] In a fifth embodiment, in any one of the first to fourth embodiment, the process further comprises preparing the radiation curable, silicone - (meth)acrylate curable composition by a process comprises: optionally dissolving starting material (B) in one or more of starting materials (C), (D), and (E); andmixing starting materials comprising (A), (B), (C), (D), (E), and (F).

[0066] In a sixth embodiment, in the process of any one of the first to fourth embodiments, starting material (A) is selected from the group consisting of bis-hydroxyl-terminated poly (dimethylsiloxane), bis-hydroxyl-terminated poly(methylphenylsiloxane), bis-hydroxyl- terminated poly(dimethylsiloxane / diphenylsiloxane) copolymer, and bis-hydroxyl-terminated poly(dimethylsiloxane / methylvinylsiloxane) copolymer.

[0067] In a seventh embodiment, in the process of any one of the first to sixth embodiments, starting material (B) comprises an average unit formula (II):MaDbTcQd(ZOi / 2)e (II) whereinM represents a monofunctional siloxane unit of formula (R' / SiOi / z): D represents a difunctional siloxane unit of formula (R^SiOz / z);T represents a trifunctional siloxane unit of formula (R'SiO z): wherein R1is as described above;Q represents a quadrifunctional siloxane unit of formula (SiOj / z): subscript a is a molar ratio of M siloxane units relative to moles of all siloxane units per molecule and has an average value of zero to 0.35; subscript b is a molar ratio of D siloxane units relative to moles of all siloxane units per molecule and has an average value of zero to 0.35; subscript c is a molar ratio of T siloxane units relative to moles of all siloxane units per molecule and has an average value of 0.60 to 1.00; subscript d is a molar ratio of Q siloxane units relative to moles of all siloxane units per molecule and has an average value of zero to 0.50; a quantity (a+b+c+d) is equal to 1.00; a ratio of subscripts a / c is zero to 0.5, a ratio of subscripts b / c is zero to 0.5; a ratio of subscript d / c is zero to 0.8; each Z is independently selected from H and an alkyl group; subscript e is a molar amount of hydrolyzable groups of formula ZO1 / 2, and subscript e has a value sufficient to provide a concentration of hydrolyzable groups of zero to 50 mole-percent based on moles of starting material (B).

[0068] In an eighth embodiment, in the process of any one of the first to seventh embodiments, starting material (B) comprises unit formula TPho.7TPro.3(HO 1 / 2)0.05, wherein TPhrepresents a unit of formula (C / .HdSi O3 / 2, and TP1represents a unit of formula (C3H7 )Si O3 / 2.

[0069] In a ninth embodiment, in the process of any one of the first to eighth embodiments,starting material (C) has formula, wherein R3is H or a methyl group, and D1is an alkane-diyl group

[0070] In a tenth embodiment, in the process of any one of the first to eighth embodiments, starting material (C) is selected from the group consisting of hydroxy ethyl acrylate, hydroxypropyl acrylate, hydroxybutyl acrylate, and a combination of two or more thereof.

[0071] In an eleventh embodiment, in the process of any one of the first to tenth embodiments, starting material (D) has formula, wherein R3is H or methyl, and R4is an alkyl group with 3 to 30 carbon atoms.

[0072] In a twelfth embodiment, in the process of any one of the first to tenth embodiments, starting material (D) is selected from the group consisting of butyl acrylate, isobutyl acrylate, n- hexyl acrylate, 2-ethylhexyl acrylate, n-heptyl acrylate, 2-methylheptylacrylate, octyl acrylate, isooctyl acrylate, nonyl acrylate, nonyl methacrylate, isononyl acrylate, laurayl acrylate, tetradecyl acrylate, cetyl acrylate, stearyl acrylate, isostearyl acrylate, and a combination of two or more thereof.

[0073] In a thirteenth embodiment, in the process of any one of the first to twelfth embodiments, starting material (E) has formula (V):, wherein each R3is independently selected from H and methyl, and D2is an alkane-diyl group of 2 to 30 carbon atoms.

[0074] In a fourteenth embodiment, in the process of any one of the first to thirteenth embodiments, starting material (E) is selected from the group consisting of: 1,6-hexanediol diacrylate; 1 ,9-nonanediol diacrylate; 1,10-decanediol diacrylate; trimethylolpropane triacrylate; propoxylated trimethylolpropane triacrylate; and a combination of two or more thereof

[0075] In a fifteenth embodiment, in the process of any one of the first to fourteenth embodiments, the radiation curable, silicone - (meth)acrylate curable composition furthercomprises a radical scavenger.

[0076] In a sixteenth embodiment, in the process of any one of the first to fifteenth embodiments, the radiation curable, silicone - (meth)acrylate curable composition further comprises an additional additive selected from the group consisting of a UV absorber, an antioxidant, a sensitizer, and a chain transfer agent.

[0077] In a seventeenth embodiment, in the process of any one of the first to sixteenth embodiments, the radiation curable, silicone - (meth) acrylate curable composition is free of (meth)acryloxyalkyl-terminated polyorganosiloxanes.

Claims

CLAIMS:

1. A radiation curable, silicone - (meth) acrylate curable composition, wherein the composition comprises starting materials (A), (B), (C), (D), (E), and (F), wherein: starting material (A) is a bis-hydroxyl terminated polydiorganosiloxane comprising unit formula (I) (R12(0H)Si0i / 2)m(R1R2(0H)Si0i / 2)n(R12Si02 / 2)o(R1R2Si02c)P(I), wherein each OH is a silicon-bonded hydroxyl group; each R1is independently selected from an alkyl group or an aryl group; each R2is an independently selected alkenyl group; subscripts m, n, o and p represent average numbers of each unit in the unit formula (I) and have values such that m > 0, n > 0, a quantity (m + n) > 2; o > 0,P > 0,0 < (p / (o + p)) < 1; and a quantity (o + p) is 1 to 1,000; starting material (B) is an aryl- functional silsesquioxane resin comprising at least 60 mole-percent trifunctional siloxane units of formula (R]SiO3 / 2) wherein R1is as described above, and in the trifunctional siloxy units said resin has a molar ratio of alkyl groups to aryl groups in the trifunctional siloxane units (alkyl / aryl ratio) of 0 / 15 to 4 / 1; wherein starting materials (A) and (B) combined are present in an amount of 100 weight parts, and a mass ratio of starting material (A) to starting material (B) ((A) / (B) ratio) is 0.1 / 1 to 15 / 1; starting material (C) is a monofunctional (meth)acrylate containing a hydroxyl group, wherein starting material (C) is present in an amount of 10 to 200 weight parts, per 100 weight parts of starting materials (A) and (B) combined; starting material (D) is a monofunctional (meth)acrylate containing alkyl groups that is free of hydroxyl groups; wherein starting material (D) is present in an amount of 20 to 800 weight parts, per 100 weight parts of starting materials (A) and (B) combined; wherein starting materials (C) and (D) combined are present in an amount of 40 to 900 weight parts, per 100 weight parts of starting materials (a) and (b) combined;starting material (E) is a multifunctional (meth)acrylate; wherein starting material (E) is present in an amount of 0.1 to 7 weight parts, per 100 weight parts of starting materials (A) and (B) combined; starting material (F) is a photoradical initiator; wherein starting material (F) is present in an amount of 0. 1 to 7 weight parts, per 100 weight parts of starting materials (A) and (B) combined.

2. The composition of claim 1, wherein starting material (A) is selected from the group consisting of bis-hydroxyl-terminated poly(dimethylsiloxane), bis-hydroxyl-terminated poly(methylphenylsiloxane), bis-hydroxyl-terminated poly(dimethylsiloxane / diphenylsiloxane) copolymer, and bis-hydroxyl-terminated poly(dimethylsiloxane / methylvinylsiloxane) copolymer.

3. The composition of claim 1 or claim 2, wherein starting material (B) comprises an average unit formula (II):MaDbTcQd(ZOi / 2)e(II) whereinM represents a monofunctional siloxane unit of formula (R^SiOic);D represents a difunctional siloxane unit of formula (R’ SiChc);T represents a trifunctional siloxane unit of formula (R Si 6)3 / 2); wherein R1is as described above;Q represents a quadrifunctional siloxane unit of formula (SiO4 / 2); subscript a is a molar ratio of M siloxane units relative to moles of all siloxane units per molecule and has an average value of zero to 0.35; subscript b is a molar ratio of D siloxane units relative to moles of all siloxane units per molecule and has an average value of zero to 0.35; subscript c is a molar ratio of T siloxane units relative to moles of all siloxane units per molecule and has an average value of 0.60 to 1.00; subscript d is a molar ratio of Q siloxane units relative to moles of all siloxane units per molecule and has an average value of zero to 0.50; a quantity (a+b+c+d) is equal to 1.00; a ratio of subscripts a / c is zero to 0.5, a ratio of subscripts b / c is zero to 0.5; a ratio of subscript d / c is zero to 0.8; each Z is independently selected from H and an alkyl group;subscript e is a molar amount of hydrolyzable groups of formula ZO1 / 2, and subscript e has a value sufficient to provide a concentration of hydrolyzable groups of zero to 50 mole-percent based on moles of starting material (B).

4. The composition of any one of claims 1 to 3, wherein starting material (B) comprises unit formula TPho7TPro3(HOi / 2)oo5, wherein TPhrepresents a unit of formula (CVHdSiCh , and TP|represents a unit of formula (C3H7)SiO3 / 2.

5. The composition of any one of claims 1 to 4, wherein starting material (C) has formula (III):, wherein R3is H or a methyl group, and D1is an alkane-diyl group6. The composition of claim 5, wherein starting material (C) is selected from the group consisting of hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxybutyl acrylate, and a combination of two or more thereof.

7. The composition of any one of claims 1 to 6, wherein starting material (D) has formula (IV):, wherein R3is H or methyl, and R4is an alkyl group with 3 to 30 carbon atoms.

8. The composition of claim 7, wherein starting material (D) is selected from the group consisting of butyl acrylate, isobutyl acrylate, n-hexyl acrylate, 2-ethylhexyl acrylate, n-heptyl acrylate, 2-methylheptylacrylate, octyl acrylate, isooctyl acrylate, nonyl acrylate, nonyl methacrylate, isononyl acrylate, laurayl acrylate, tetradecyl acrylate, cetyl acrylate, stearyl acrylate, isostearyl acrylate, and a combination of two or more thereof.

9. The composition of any one of claims 1 to 8, wherein starting material (E) has formula (V):, wherein each R3is independently selected from H and methyl, and D2is an alkane-diyl group of 2 to 30 carbon atoms.

10. The composition of any one of claims 1 to 8, wherein starting material (E) is selected from the group consisting of: 1,6-hexanediol diacrylate; 1 ,9-nonanediol diacrylate; 1,10-decanediol diacrylate; trimethylolpropane triacrylate; propoxylated trimethylolpropane triacrylate; and a combination of two or more thereof11. A process for preparing an adhesive, wherein the process comprises:1) applying the composition of any one of claims 1 to 10 onto a first object, and2) applying a second object to the composition, so as to sandwich the composition between and in contact with the first object and the second object.

12. The process of claim 11, further comprising curing the composition by exposing the composition to ultraviolet radiation.

13. The process of claim 11 or claim 12, further comprising pre-curing the composition by exposing the composition to ultraviolet radiation after applying the composition to the first surface of the first object and before applying the second surface of the second object to the composition.

14. The process of any one of claims 11 to 13, wherein step 1) is performed via inkjet printing.

15. A process for preparing the composition of any one of claims 1 to 10, wherein the process comprises: optionally dissolving starting material (B) in one or more of starting materials (C), (D), and (E); and mixing starting materials comprising (A), (B), (C), (D), (E), and (F).

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