UV curable silicone composition and an encapsulant or a sheet film thereof

Abstract

A UV curable silicone composition has exceptional curability by ultraviolet irradiation. The UV curable silicone composition includes (A) an organopolysiloxane composition selected from the following: (A-1) an organopolysiloxane composition comprising a linear organopolysiloxane in which both ends of the molecular chain are capped with alkenyl groups and/or a branched organopolysiloxane containing at least 2 alkenyl groups at the ends of the molecular chain, and an organopolysiloxane containing at least 2 thiol groups in side-chains of the molecular chain, wherein the thiol group content is 1% by mass or more per molecule, (A-2) an organopolysiloxane composition comprising a linear organopolysiloxane in which both ends of the molecular chain are capped with thiol groups, wherein the thiol group content is 1% by mass or more per molecule, and an organopolysiloxane containing at least 2 alkenyl groups in side-chains of the molecular chain and/or a resinous organopolysiloxane containing at least 2 alkenyl groups at the ends of the molecular chain, or (A-3) an organopolysiloxane composition comprising an alkenyl group- and aryl group-containing organopolysiloxane and a multifunctional thiol compound, but furthermore comprising an alkenyl group-containing resinous organopolysiloxane when the multifunctional thiol compound contains only a bifunctional thiol compound, and (B) a silicone-compatible photo-initiator comprising a compound selected from the following: (B-1) an alpha-hydroxyacetophenone, (B-2) a combination of an alpha-hydroxyacetophenone and an alpha-aminoalkylphenone, or (B-3) a combination of an alpha-hydroxyacetophenone and a mono-acylphosphine oxide, wherein the ratio between the thiol groups and alkenyl groups (SH/Vi ratio) included in the organopolysiloxane composition is 0.6 or more.

Claims

1. An encapsulant for an optical semiconductor that is a cured product of curable silicone composition comprising: (A) an organopolysiloxane composition selected from the following; (A-1) an organopolysiloxane composition comprising a linear organopolysiloxane in which both ends of the molecular chain are capped with alkenyl groups and/or a branched organopolysiloxane containing at least 2 alkenyl groups at the ends of the molecular chain, and an organopolysiloxane containing at least 2 thiol groups in side-chains of the molecular chain, wherein the thiol group content is 1% by mass or more per molecule, (A-2) an organopolysiloxane composition comprising a linear organopolysiloxane in which both ends of the molecular chain are capped with thiol groups, wherein the thiol group content is 1% by mass or more per molecule, and an organopolysiloxane containing at least 2 alkenyl groups in side-chains of the molecular chain and/or a resinous organopolysiloxane containing at least 2 alkenyl groups at the ends of the molecular chain, or (A-3) an organopolysiloxane composition comprising an alkenyl group- and aryl group-containing organopolysiloxane and a multifunctional thiol compound, provided that component (A-3) comprises an alkenyl group-containing resinous organopolysiloxane when the multifunctional thiol compound contains only a bifunctional thiol compound, and (B) a silicone-miscible photo-initiator comprising a compound selected from the following: (B-1) an alpha-hydroxyacetophenone, (B-2) a combination of an alpha-hydroxyacetophenone and an alpha-aminoalkylphenone, or (B-3) a combination of an alpha-hydroxyacetophenone and a mono-acylphosphine oxide, wherein the mole ratio between the thiol groups (—SH) and alkenyl groups (—SH/Vi ratio) included in the organopolysiloxane composition is 0.6 or more.

2. An adhesive sheet film that is a cured product of curable silicone composition comprising: (A) an organopolysiloxane composition selected from the following; (A-1) an organopolysiloxane composition comprising a linear organopolysiloxane in which both ends of the molecular chain are capped with alkenyl groups and/or a branched organopolysiloxane containing at least 2 alkenyl groups at the ends of the molecular chain, and an organopolysiloxane containing at least 2 thiol groups in side-chains of the molecular chain, wherein the thiol group content is 1% by mass or more per molecule, (A-2) an organopolysiloxane composition comprising a linear organopolysiloxane in which both ends of the molecular chain are capped with thiol groups, wherein the thiol group content is 1% by mass or more per molecule, and an organopolysiloxane containing at least 2 alkenyl groups in side-chains of the molecular chain and/or a resinous organopolysiloxane containing at least 2 alkenyl groups at the ends of the molecular chain, or (A-3) an organopolysiloxane composition comprising an alkenyl group- and aryl group-containing organopolysiloxane and a multifunctional thiol compound, provided that component (A-3) comprises an alkenyl group-containing resinous organopolysiloxane when the multifunctional thiol compound contains only a bifunctional thiol compound, and (B) a silicone-miscible photo-initiator comprising a compound selected from the following: (B-1) an alpha-hydroxy acetophenone, (B-2) a combination of an alpha-hydroxyacetophenone and an alpha-aminoalkylphenone, or (B-3) a combination of an alpha-hydroxyacetophenone and a mono-acylphosphine oxide, wherein the mole ratio between the thiol groups (—SH) and alkenyl groups (—SH/Vi ratio) included in the organopolysiloxane composition is 0.6 or more.

3. An encapsulant for optical semiconductor as claimed in claim 1, wherein the organopolysiloxane containing at least 2 thiol groups in side-chains of the molecular chain in component (A-1) is a cyclic structure.

4. An encapsulant for optical semiconductor as claimed in claim 1, wherein the organopolysiloxane containing at least 2 thiol alkenyl groups in side-chains of the molecular chain in component (A-2) is a linear structure.

5. An encapsulant for optical semiconductor as claimed in claim 1, wherein the photo-initiator of (B-1) further comprises a compound having an acetophenone structure other than alpha-hydroxyacetophenone.

6. An encapsulant for optical semiconductor as claimed in claim 1, wherein the content of component (B) is 0.001% by mass to 5% by mass based on the total mass of the UV curable silicone composition.

7. An adhesive sheet film as claimed in claim 2, wherein the organopolysiloxane containing at least 2 thiol groups in side-chains of the molecular chain in component (A-1) is a cyclic structure.

8. An adhesive sheet film as claimed in claim 2, wherein the organopolysiloxane containing at least 2 alkenyl groups in side-chains of the molecular chain in component (A-2) is a linear structure.

9. An adhesive sheet film as claimed in claim 2, wherein the photo-initiator of (B-1) further comprises a compound having an acetophenone structure other than alpha-hydroxyacetophenone.

10. An adhesive sheet film as claimed in claim 2, wherein the content of component (B) is 0.001% by mass to 5% by mass based on the total mass of the UV curable silicone composition.

Description

EXAMPLES

(1) The UV curable silicone composition of the present disclosure is described in greater detail by means of the following examples and comparative examples.

(2) The starting material components shown below were used in the following examples and comparative examples. Below, Me represents a methyl group, Vi represents a vinyl group, and Ph represents a phenyl group. Component a-1-1: Linear organopolysiloxane in which both ends of the molecular chain are capped with vinyl groups, which is represented by general formula ViMe.sub.2 SiO(Me.sub.2SiO).sub.310SiMe.sub.2Vi Component a-1-2: Linear organopolysiloxane in which both ends of the molecular chain are capped with vinyl groups, which is represented by general formula ViMe.sub.2 SiO(Me.sub.2SiO).sub.150SiMe.sub.2Vi Component a-1-3: Linear organopolysiloxane in which both ends of the molecular chain are capped with vinyl groups, which is represented by general formula ViMe.sub.2 SiO(Me.sub.2SiO).sub.530SiMe.sub.2Vi Component a-1-4: Linear organopolysiloxane in which both ends of the molecular chain are capped with vinyl groups, which is represented by general formula ViMe.sub.2 SiO(Me.sub.2SiO).sub.770SiMe.sub.2Vi Component a-1-5: Linear organopolysiloxane in which both ends of the molecular chain are capped with vinyl groups, which is represented by general formula ViMe.sub.2SiO(Me.sub.2SiO).sub.nSiMe.sub.2Vi, wherein the viscosity is 60 mPas, and the vinyl group content is 1.5 mol % Component a-2-1: Linear organopolysiloxane having a vinyl group in a side-chain of the molecular chain, which is represented by unit formula Me.sub.3SiO(MeViSiO).sub.n(Me.sub.2SiO).sub.mSiMe.sub.3, wherein the viscosity is 35000 mPas, and the alkenyl group content is 0.5 wt % Component a-2-2: Linear organopolysiloxane having a vinyl group in a side-chain of the molecular chain, which is represented by unit formula Me.sub.3SiO(MeViSiO).sub.n(Me.sub.2SiO).sub.mSiMe.sub.3, wherein the viscosity is 8000 mPas, and the vinyl group content is 0.3 wt % Component a-2-3: Linear organopolysiloxane having vinyl groups at the ends of, and in a side-chain of, the molecular chain, which is represented by unit formula ViMe.sub.2SiO(MeViSiO).sub.n(Me.sub.2SiO).sub.mSiMe.sub.2Vi, wherein the viscosity is 370 cSt, and the vinyl group content is 1.1 wt % Component a-2-4: 1,3,5,7-tetramethyl-1,3,5,7-tetravinylcyclotetrasiloxane Component a-2-5: Branched alkenyl group-containing organopolysiloxane represented by (ViMe.sub.2SiO).sub.3(PhSiO.sub.3/2) Component a-3-1: Organopolysiloxane containing a thiol group in a side-chain of the molecular chain, which is represented by unit formula (Me.sub.2SiO).sub.n(HSMeSiO).sub.m, wherein the viscosity is 100 mPas, and the thiol group content is 3.6 wt % Component a-3-2: Organopolysiloxane containing a thiol group in a side-chain of the molecular chain, which is represented by unit formula (Me.sub.2SiO).sub.n(HSMeSiO).sub.m, wherein the viscosity is 150 mPas, and the thiol group content is 4.6 wt % Component a-3-3: Organopolysiloxane containing a thiol group in a side-chain of the molecular chain, which is represented by unit formula (Me.sub.2SiO).sub.n(HSMeSiO).sub.m, wherein the viscosity is 150 mPas, and the thiol group content is 1.5 wt % Component a-3-4: Organopolysiloxane containing a thiol group in a side-chain of the molecular chain, which is represented by unit formula (HSMeSiO).sub.n, wherein the viscosity is 100 mPas, and the thiol group content is 23 wt % Component a-3-5: Organopolysiloxane containing a thiol group in a side-chain of the molecular chain, which is represented by unit formula (Me.sub.2SiO).sub.n(HSMeSiO).sub.m, wherein the viscosity is 150 mPas, and the thiol group content is 0.8 wt % Component a-4-1: Linear organopolysiloxane in which both ends of the molecular chain are capped with thiol groups, which is represented by unit formula HSMe.sub.2SiO(Me.sub.2SiO).sub.nSiMe.sub.2SH, wherein the viscosity is 90 mPas, and the thiol group content is 1.4 wt % Component a-4-2: Linear organopolysiloxane in which both ends of the molecular chain are capped with thiol groups, which is represented by unit formula HSMe.sub.2SiO(Me.sub.2SiO).sub.nSiMe.sub.2SH, wherein the viscosity is 55 mPas, and the thiol group content is 2.0 wt % Component a-5-1: Phenyl group-containing linear organopolysiloxane in which both ends of the molecular chain are capped with vinyl groups, which is represented by general formula ViMe.sub.2 SiO(PhMeSiO).sub.20SiMe.sub.2Vi Component a-5-2: Phenyl group-containing linear organopolysiloxane in which both ends of the molecular chain are capped with vinyl groups, which is represented by general formula ViMe.sub.2 SiO(Me.sub.2 SiO).sub.200(Ph.sub.2SiO).sub.50SiMe.sub.2Vi Component a-5-3: Phenyl group-containing linear organopolysiloxane in which both ends of the molecular chain are capped with vinyl groups, which is represented by general formula ViMe.sub.2 SiO(Me.sub.2 SiO).sub.60(Ph.sub.2SiO).sub.30SiMe.sub.2Vi Component a-6-1: Resinous vinyl group-containing organopolysiloxane represented by unit formula (ViMe.sub.2SiO.sub.1/2).sub.4(Me.sub.3SiO.sub.1/2).sub.40(SiO.sub.4/2).sub.56 Component a-6-2: Resinous vinyl group-containing organopolysiloxane represented by unit formula (ViMe.sub.2SiO.sub.1/2).sub.11(Me.sub.3SiO.sub.1/2).sub.34(SiO.sub.4/2).sub.55 Component a-6-3: Resinous vinyl group-containing organopolysiloxane represented by unit formula (ViMe.sub.2SiO.sub.1/2).sub.15(Me.sub.3SiO.sub.1/2).sub.45(SiO.sub.4/2).sub.40 Component a-6-4: Resinous vinyl group-containing organopolysiloxane represented by unit formula (ViMe.sub.2SiO.sub.1/2).sub.10(Me.sub.3SiO.sub.1/2).sub.40(SiO.sub.4/2).sub.50 Component a-6-5: Resinous vinyl group- and phenyl group-containing organopolysiloxane represented by unit formula (ViMe.sub.2SiO.sub.1/2).sub.25(PhSiO.sub.3/2).sub.75 Component a-6-6: Resinous vinyl group- and phenyl group-containing organopolysiloxane represented by unit formula (ViMe.sub.2SiO.sub.1/2).sub.15(Me.sub.2SiO.sub.2/2).sub.35(PhSiO.sub.3/2).sub.50 Component a-6-7: Resinous vinyl group- and phenyl group-containing organopolysiloxane represented by unit formula (ViMeSiO.sub.2/2).sub.25(Ph.sub.2SiO.sub.2/2).sub.35(PhSiO.sub.3/2).sub.45 Component a-7-1: Trifunctional secondary thiol compound represented by compositional formula C.sub.18H.sub.32O.sub.6S.sub.3 trimethylolpropane tris (3-mercaptobutyrate) Component a-7-2: Bifunctional primary thiol compound represented by compositional formula HSCH.sub.2CH.sub.2OCH.sub.2CH.sub.2OCH.sub.2CH.sub.2SH 2,2′-(ethylenedioxy) diethanethiol. Component a-7-3: Bifunctional primary thiol compound represented by compositional formula (HSCH.sub.2COOCH.sub.2).sub.2 ethylene glycol bismercaptoacetate Component a-7-4: Trifunctional primary thiol compound represented by composition formula (HSCH.sub.2CH.sub.2CO.sub.2CH.sub.2).sub.3CC.sub.2H.sub.5 trimethylolpropane tris (3-mercaptopropionate) Component a-7-5: Tetrafunctional primary thiol compound represented by composition formula (HSCH.sub.2CH.sub.2COOCH.sub.2).sub.4C pentaerythritol tetrakis (3-mercaptopropionate) Component a-7-6: Bifunctional secondary thiol compound represented by compositional formula C.sub.12H.sub.22O.sub.4S.sub.2 1,4-bis (3-mercaptobutyryloxy) butane Component a-7-7: Trifunctional primary thiol compound represented by compositional formula C.sub.18H.sub.27N.sub.3O.sub.9S.sub.3 tris [2-(3-mercaptopropionyloxy)ethyl]isocyanurate Component a-7-8: Trifunctional secondary thiol compound represented by compositional formula C.sub.21H.sub.33O.sub.9N.sub.3S.sub.3 1,3,5-tris (2-(3-sulfanylbutanoyloxy) ethyl)-1,3,5-triazinane-2,4,6-trione Component a-7-9: Tetrafunctional secondary thiol compound represented by compositional formula C.sub.21H.sub.36O.sub.8S.sub.4 pentaerythritol tetrakis (3-mercaptobutyrate) Component b-1: 2-hydroxy-2-methyl-1-phenyl-1-propanone (by IGM Resins B. V.; brand name: Omnirad 1173) Component b-2: 1,1′-(methylene-di-4,1-phenylene) bis [2-hydroxy-2-methyl-1-propanone] (by IGM Resins B. V.; brand name: Omnirad 127D) Component b-3: 1-hydroxycyclohexyl-phenylketone (by IGM Resins B. V.; brand name: Omnirad 184) Component b-4: 2-methyl-1-[4-(methylthio)phenyl]-2-(4-morpholinyl)-propan-1-one (by IGM Resins B. V.; brand name: Omnirad 907) Component b-5: 2-dimethylamino-2-(4-methylbenzyl)-1-(4-morpholin-4-yl-phenyl)-butan-1-one (by IGM Resins B. V.; brand name: Omnirad 379EG) Component b-6: Phenyl-(2,4,6-trimethylbenzoyl)-phosphinate ethyl ester (by IGM Resins B. V.; brand name: Omnirad TPO-L). Component b-7: 2,4,6-trimethylbenzoyl)-diphenyl-phosphine oxide (by IGM Resins B. V.; brand name: Omnirad TPO-H). Component b-8: 2-benzyl-2-(dimethylamino)-4′-morpholinobutyrophenone (by IGM Resins B. V.; brand name: Omnirad 369) Component b′-1: Methyl benzoylformate (by IGM Resins B. V.; brand name: Omnirad MBF) Component b′-2: 2,4-diethylthioxanthen-9-one (DETX) Component b′-3: phenyl bis (2,4,6-trimethylbenzoyl)-phosphine oxide (by IGM Resins B. V.; brand name: Omnirad 819) Component b′-4: Ethyl 4-(dimethylamino)benzoate (by IGM Resins B. V.; brand name: Omnirad EDB) Component b′-5: 1,1′-(oxybis(4,1-phenylene))bis (2-hydroxy-2-methylpropan-1-one (by LEHVOSS; brand name: Esacure KIP160) Component b′-6: 1-[4-(4-benzoylphenylsulfanyl)phenyl]-2-methyl-2-(4-methylphenylsulfonyl)propan-1-one (by LEHVOSS; brand name: Esacure E1001M) Component b′-7: Thioxanthone-based photo-initiator (by LEHVOSS; brand name: Esacure One) Component b′-8: (4,4′-bis(diethylamino)benzophenone (by IGM Resins B. V.; brand name: Omnirad EMK) Component b′-9: Polybutylene glycol bis(4-benzoylphenoxy)acetate (by IGM Resins B. V.; brand name: Omnipol BP) Component b′-10: 2,2-dimethoxy-2-phenylacetophenone (by IGM Resins B.I.V.; brand name: Omnirad 651) Component c: Photo-sensitizer Anthracure (registered trademark) UVS-1331 (by Kawasaki Kasei Chemicals Ltd.)

Examples 1-53 and Comparative Examples 1-34

(3) UV silicone compositions were prepared by mixing the respective components in the proportions (% by mass) shown in Tables 1 through 9. The “SH/Vi ratio” in the tables indicates the molar ratio between the thiol groups and vinyl groups in the organopolysiloxane components.

EVALUATION

(4) The curability of the compositions in the examples and comparative examples was determined as shown below, and the results are shown in Tables 1 through 9.

(5) The resulting compositions were applied with the use of a blade coater to a thickness of 10 m on PET films. Films were obtained by curing the compositions via ultraviolet light irradiation as described in (1) through (3) below using a metal halide lamp. (1) Wavelength 254 nm; 5.4 mJ/cm.sup.2 (irradiation for 1 min) (2) Wavelength 365 nm; 12.3 J/cm.sup.2 (irradiation for 1 min) (3) Wavelength 405 nm; 69.3 J/cm.sup.2 (irradiation for 1 min)

(6) The resulting films were cut to a size of 5×5 cm.sup.2, the resulting cut samples were dipped in 50 mL of toluene, washed for 30 minutes, and then dried for 90 minutes at 120° C., and the residual weight was determined. The residual weight values that were determined are shown in Tables 1 through 5 below. Compositions having a residual weight of 50% or more can be assessed as having exceptional curability. “Not mixed” indicates compositions in which components (A) and (B) could not be mixed, and “not cured” indicates compositions that could not be cured.

(7) TABLE-US-00001 TABLE 1 Example Example Example Example Example Example Example Example Example Example Component 1 2 3 4 5 6 7 8 9 10 a-1-1 90.7 90.7 90.7 90.7 90.7 90.7 90.7 90.7 42 28.8 a-2-1 — — — — — — — — — — a-3-1 8.3 8.3 8.3 8.3 8.3 8.3 8.3 8.3 24 46 a-6-1 — — — — — — — — 33 22.7 b-1 1 0.875 0.67 0.66 0.91 0.5 0.8 0.91 1 2.5 b-2 — 0.125 — — — — — — — — b-3 — — 0.33 — — — — — — — b-4 — — — 0.33 — — — — — — b-5 — — — — 0.09 — — — — — b-6 — — — — — 0.5 — — — — b-7 — — — — — — 0.2 — — — b-8 — — — — — — — 0.09 — — Total 100 100 100 100 100 100 100 100 100 100 SH/Vi 1.2 1.2 1.2 1.2 1.2 1.2 1.2 1.2 0.9 2.54 ratio Evaluation Residual 50 51 55 55 60 55 66 60 60 80 weight (%)

(8) TABLE-US-00002 TABLE 2 Example Example Example Example Example Example Example Example Example Example Example Component 11 12 13 14 15 16 17 18 19 20 21 a-1-1 — — 46.5 — — — 8.4 23.2 90.7 42 81.5 a-1-2 84 — — — — — — — — — — a-1-3 — 93.8 — — 41.3 — — — — — — a-1-4 — — 46.5 — — 30 66 20 — — — a-1-5 — — — 60 — — — — — — — a-3-1 15 5.2 6.0 39 33.4 43 — — — — — a-3-2 — — — — — — — — 8.3 24 — a-3-3 — — — — — — — — — — 17.5 a-4-1 — — — — — — 18 37.5 — — — a-6-1 — — — — — — 6.6 18.3 — 33 — a-6-2 — — — — 24.3 — — — — — — a-6-3 — — — — — 26 — — — — — b-1 1 1 1 1 1 1 1 1 1 1 1 Total 100 100 100 100 100 100 100 100 100 100 100 SH/Vi 1.2 1.2 1.2 1.2 0.9 0.9 1.0 1.0 1.5 1.1 1.2 ratio Evaluation Residual 55 50 50 83 75 55 50 54 90 95 50 weight (%)

(9) TABLE-US-00003 TABLE 3 Example Example Example Example Example Example Example Example Example Example Component 22 23 24 25 26 27 28 29 30 31 a-1-1 97.6 — — — — — — — — — a-1-2 — — — — — — — — 13.1 — a-1-3 — 41.4 — — — — — 14.6 — — a-1-5 — — — — — — 10.2 — — — a-3-1 — — — — — — 49 44 45.5 — a-3-3 — 30 — — — — — — — — a-3-4 1.4 3.2 — — — — — — — — a-5-1 — — — — — — — — — 90.5 a-5-2 — — 97.6 — — 71 — — — — a-5-3 — — — 96 94.9 — — — — — a-6-2 — 24.3 — — — — — — — — a-6-3 — — — — — 19 — — — — a-6-4 — — — — — 1 39.8 40.4 40.4 — a-7-1 — — 1.4 — — 8 — — — — a-7-4 — — — — — — — — — 8.5 a-7-8 — — — — 4.1 — — — — — a-7-9 — — — 3 — — — — — — b-1 1 1 1 1 1 1 1 1 1 1 Total 100 100 100 100 100 100 100 100 100 100 SH/Vi 1.2 1.2 1.2 1.2 1.2 1.3 1.0 0.9 0.9 1.2 ratio Evaluation Residual 50 77 60 65 60 61 72 72 70 60 weight (%)

(10) TABLE-US-00004 TABLE 4 Example Example Example Example Example Example Example Example Example Example Component 32 33 34 35 36 37 38 39 40 41 a-1-1 — — — — 29.7 26.3 — — — — a-1-4 — — — — — 10 — — — — a-2-4 — 20 — — — — — — — — a-2-5 — — — 41 — — — — — — a-4-1 — — — — 46 42 — — — — a-5-1 90.5 34 62.5 15 — — 93 62.5 62.5 62.5 a-6-1 — — — — 23.3 20.7 — — — — a-6-5 — — 22.5 — — — — 22.5 — — a-6-6 — — — — — — — — 22.5 — a-6-7 — — — — — — — — — 22.5 a-7-1 — 45 14 43 — — 6 — 14 14 a-7-2 — — — — — — — 14 — — a-7-5 8.5 — — — — — — — — — b-1 1 1 1 1 1 1 1 1 1 1 Total 100 100 100 100 100 100 100 100 100 100 SH/Vi 1.2 1.2 1.2 1.0 0.9 1.0 0.8 1.2 1.5 1.3 ratio Evaluation Residual 65 88 68 84 54 59 60 60 71 59 weight (%)

(11) TABLE-US-00005 TABLE 5 Exam- Exam- Exam- Exam- Exam- Exam- Exam- Exam- Exam- Exam- Exam- Exam- ple ple ple ple ple ple ple ple ple ple ple ple Component 42 43 44 45 46 47 48 49 50 51 52 53 a-1-1 42 28.8 42 28.8 — — — — — — — — a-2-1 — — — — 65 — — 71 — — — — a-2-2 — — — — — 75 — — — — — — a-2-3 — — — — — — 47 — — — — — a-3-1 24 46 24 46 — — — — — — — — a-4-1 — — — — 34 24 52 — — — — — a-4-2 — — — — — — — 28 — — — — a-5-1 — — — — — — — — 90.5 90.5 90.5 90.5 a-6-1 33 22.7 33 22.7 — — — — — — — — a-7-1 — — — — — — — — 8.5 8.5 8.5 8.5 b-1 0.91 2.27 0.8 2 1 1 1 1 1 0.66 0.91 0.8 b-4 — — — — — — — — — 0.33 — — b-5 0.09 0.23 — — — — — — — — 0.09 — b-7 — — 0.2 0.5 — — — — — — — 0.2 Total 100 100 100 100 — — — — — — — — SH/Vi 0.9 2.54 0.9 2.54 1.2 1.2 1.2 1.2 1.2 1.2 1.2 1.2 ratio Evaluation Residual 70 95 67 85 65 55 72 61 67 66 66 65 weight (%)

(12) TABLE-US-00006 TABLE 6 Comparative Comparative Comparative Comparative Comparative Comparative Comparative Comparative Comparative Example Example Example Example Example Example Example Example Example Component 1 2 3 4 5 6 7 8 9 a-1-1 90.7 90.7 90.7 90.7 90.7 90.7 95 90 — a-3-1 8.3 8.3 8.3 8.3 8.3 8.3 4 — — a-3-3 — — — — — — — 9 — a-5-1 — — — — — — — — 95 a-7-1 — — — — — — — — 4 b-1 — — 0.5 — 0.75 — 1 1 1 b-7 1 — — — — — — — — b′-1 — 1 0.5 0.99 — 0.91 — — — b′-2 — — — — 0.25 — — — — b′-3 — — — — — 0.09 — — — c — — — 0.01 — — — — — Total 100 100 100 100 100 100 100 100 100 SH/Vi 1.2 1.2 1.2 1.2 1.2 1.2 0.55 0.55 0.55 ratio Evaluation Residual 40 20 20 20 20 40 40 30 20 weight (%)

(13) TABLE-US-00007 TABLE 7 Comparative Comparative Comparative Comparative Comparative Comparative Comparative Comparative Example Example Example Example Example Example Example Example Component 10 11 12 13 14 15 16 17 a-1-1 90.7 90.7 90.7 90.7 90.7 90.7 90.7 90.7 a-3-1 8.3 8.3 8.3 8.3 8.3 8.3 8.3 8.3 b-1 — — 0.91 — — — — — b-7 — — — — — — — 1 b′-4 1 — — — — — — — b′-5 — 1 — — — — — — b′-6 — — 0.09 — — — — — b′-7 — — — 1 — — — — b′-8 — — — — 1 — — — b′-9 — — — — — 1 — — b′-10 — — — — — — 1 — Total 100 100 100 100 100 100 100 100 SH/Vi 1.2 1.2 1.2 1.2 1.2 1.2 1.2 1.2 ratio Evaluation State Not Not Not Not Not Not Not Not mixed mixed mixed mixed mixed mixed mixed mixed

(14) TABLE-US-00008 TABLE 8 Compar- Compar- Compar- Compar- Compar- Compar- Compar- Compar- Compar- Compar- Compar- Compar- ative ative ative ative ative ative ative ative ative ative ative ative Compo- Exam- Exam- Exam- Exam- Exam- Exam- Exam- Exam- Exam- Exam- Exam- Exam- nent ple 18 ple 19 ple 20 ple 21 ple 22 ple 23 ple 24 ple 25 ple 26 ple 27 ple 28 ple 29 a-5-1 90.5 90.5 90.5 90.5 90.5 96 90.5 90.5 90.5 90.5 90.5 90.5 a-7-1 8.5 8.5 8.5 8.5 8.5 3 — — — — — — a-7-6 — — — — — — 8.5 8.5 8.5 27 — — a-7-7 — — — — — — — — — — — 8.5 a-7-8 — — — — — — — — — 8.5 — — a-7-9 — — — — — — — — — — 8.5 — b-1 — 0.91 — — — — 1 — — — — — b-6 — — — — — — — 1 — — — — b-7 — — — — 1 1 — — — — — — b′-1 — — — — — — — — 0.91 — — — b′-3 — — — — — — — — 0.09 — — — b′-5 1 — — — — — — — — — — — b′-6 — 0.09 — — — — — — — — — — b′-7 — — 1 — — — — — — — — — b′-8 — — — 1 — — — — — — — — Total 100 100 100 100 100 100 100 100 100 100 100 100 SH/Vi 1.2 1.2 1.2 1.2 1.2 0.4 1.2 1.2 1.2 1.2 1.2 1.2 ratio Evaluation State Not Not Not Not Not Not Not Not Not Not Not Not mixed mixed mixed mixed mixed cured cured cured cured mixed mixed mixed

(15) TABLE-US-00009 TABLE 9 Comp- Comp- Comp- Comp- Comp- arative arative arative arative arative Example Example Example Example Example Component 30 31 32 33 34 a-1-1 — — 69 — — a′-3-5 — — 30 — — a-5-1 90.5 90.5 — 90.5 90.5 a-7-1 — — — 8.5 8.5 a-7-2 8.5 — — — — a-7-3 — 8.5 — — — b-1 1 1 1 — — b′-9 — — — 1 — b′-10 — — — — 1 Total 100 100 100 100 100 SH/Vi 1.2 1.2 1.2 1.2 1.2 ratio Evaluation Residual Not Not 30 Not Not weight cured cured mixed mixed (%)

(16) The above results show that the UV curable silicone compositions of Examples 1 through 53 of the present disclosure had exceptional UV irradiation curability. The UV curable silicone compositions of the present disclosure thus

INDUSTRIAL APPLICABILITY

(17) The UV curable silicone composition of the present disclosure is particularly useful in providing encapsulants for electronic devices, particularly optical semiconductor devices such as light emitting diodes (LEDs), semiconductor lasers, photodiodes, phototransistors, solid-state imaging, and light emitters and light receivers for photocouplers, as well as adhesive sheet films for mass transfer.