Optical assembly and method of forming an optical assembly
View Patent ↗Optical assemblies comprising an optical device and a composition comprising a resin-linear organosiloxane block copolymer are disclosed. In some embodiments, the organosiloxane block copolymers has a weight average molecular weight of at least 20,000 g/mole and includes 40 to 90 mole percent disiloxy units of the formula [R 1 2SiO 2/2 ] arranged in linear blocks each having an average of from 10 to 400 disiloxy units [R 1 2SiO 2/2 ] per linear block, 10 to 60 mole percent trisiloxy units of the formula [R 2 —SiO 3/2 ] arranged in non-linear blocks each having a weight average molecular weight of at least 500 g/mol, and 0.5 to 25 mole percent silanol groups. R 1 is independently a C 1 to C 30 hydrocarbyl and R 2 is independently a C 1 to C 20 hydrocarbyl. At least 30% of the non-linear blocks are crosslinked with another non-linear block and aggregated in nano-domains. Each linear block is linked to at least one non-linear block.
1. A method of forming an optical assembly comprising an optical device and a composition comprising a resin-linear organosiloxane block copolymer, said method comprising the step of combining the optical device and the composition to form the optical assembly, wherein the resin-linear organosiloxane block copolymer has a weight average molecular weight of at least 20,000 g/mole and comprises:
40 to 90 mole percent disiloxy units of the formula [R 1 2 SiO 2/2 ] arranged in linear blocks each having an average of from 10 to 400 disiloxy units [R 1 2 SiO 2/2 ] per linear block;
10 to 60 mole percent trisiloxy units of the formula [R 2 SiO 3/2 ] arranged in non-linear blocks each having a weight average molecular weight of at least 500/mol; and
0.5 to 25 mole percent silanol groups;
wherein R 1 is independently a C 1 to C 30 hydrocarbyl and R 2 is independently a C 1 to C 20 hydrocarbyl,
wherein at least 30 weight percent of the non-linear blocks are crosslinked with another non-linear block and aggregated in nano-domains and
wherein each linear block is linked to at least one non-linear block.
2. The method of claim 1 , wherein the step of combining comprises melting the composition such that the composition is disposed on the optical device.
3. The method of claim 2 , wherein the composition is in direct contact with the optical device.
4. The method of claim 1 further comprising the step of providing a solution of the composition in a solvent and optionally removing the solvent to form the composition prior to the step of combining the optical device and the composition.
5. The method of claim 4 , further comprising the step of forming the composition into a sheet subsequent to the step of removing the solvent and prior to the step of combining the optical device and the composition.
6. The method of claim 1 , further comprising the step of further curing the composition.
7. An optical assembly comprising an optical device and a composition comprising a resin-linear organosiloxane block copolymer, wherein the resin-linear organosiloxane block copolymer has a weight average molecular weight of at least 20,000 g/mole and comprises:
40 to 90 mole percent disiloxy units of the formula [R 1 2 SiO 2/2 ] arranged in linear blocks each having an average of from 10 to 400 disiloxy units [R 1 2 SiO 2/2 ] per linear block;
10 to 60 mole percent trisiloxy units of the formula [R 2 SiO 3/2 ] arranged in non-linear blocks each having a weight average molecular weight of at least 500 g/mole; and
0.5 to 25 mole percent silanol groups;
wherein R 1 is independently a C 1 to C 30 hydrocarbyl and R 2 is independently a C 1 to C 20 hydrocarbyl,
wherein at least 30 weight percent of the non-linear blocks are crosslinked with another non-linear block and aggregated in nano-domains and
wherein each linear block is linked to at least one non-linear block.
8. The optical assembly of claim 7 , wherein the optical assembly comprises a solid state light.
9. The optical assembly of claim 7 , wherein the optical device comprises at least one coherent light source or incoherent/partially coherent light source.
10. The optical assembly of claim 7 , wherein the optical device comprises at least one coherent light source.
11. The optical assembly of claim 7 , wherein the optical device comprises at least one incoherent/partially coherent light source and the at least one incoherent/partially coherent light source comprises an LED.
12. The optical assembly of claim 7 , wherein the composition is in direct contact with the optical device.
13. The optical assembly of claim 7 , wherein the optical assembly comprises a phosphor.
14. The optical assembly of claim 7 , wherein the disiloxy units have the formula [(CH 3 )(C 6 H 5 )SiO 2/2 ].
15. The optical assembly of claim 7 , wherein the organosiloxane block copolymer comprises at least 30 weight percent disiloxy units.
16. The optical assembly of claim 7 , wherein R 2 is phenyl.
17. The optical assembly of claim 7 , wherein the composition has a melt flow temperature of from 25° C. to 200° C.
18. The optical assembly of claim 7 , wherein the composition has greater than 95% light transmittance as determined using ASTM D1003.
19. The optical assembly of claim 7 , wherein the composition has a refractive index greater than 1.4.