Compositions comprising resin-linear organosiloxane block copolymers and organopolysiloxanes
View Patent ↗Resin-linear organosiloxane block copolymers combined with linear or resin organopolysiloxane components are disclosed. In some embodiments, the combination of resin-linear organosiloxane block copolymers with linear or resin organopolysiloxane components provides compositions having improved physical properties, such as improved toughness and flow behavior.
1. A composition comprising:
A) one or more resin-linear organosiloxane block copolymer compositions comprising:
40 to 90 mole percent disiloxy units of the formula [R 1 2 SiO 2/2 ],
10 to 60 mole percent trisiloxy units of the formula [R 2 SiO 3/2 ],
0.5 to 35 mole percent silanol groups [≡SiOH];
wherein:
each R 1 , at each occurrence, is independently a C 1 to C 30 hydrocarbyl,
R 2 , at each occurrence, is independently a C 1 to C 20 hydrocarbyl;
wherein:
the disiloxy units [R 1 2 SiO 2/2 ] are arranged in linear blocks having an average of from 10 to 400 disiloxy units [R 1 2 SiO 2/2 ] per linear block,
the trisiloxy units [R 2 SiO 3/2 ] are arranged in non-linear blocks having a molecular weight of at least 500 g/mole, and at least 30% of the non-linear blocks are crosslinked with each other, each linear block is linked to at least one non-linear block, and
the organosiloxane block copolymer has a weight average molecular weight (M w ) of at least 20,000 g/mole; and
B) at least one of a phenyl silsesquioxane resin and a polydiorganosiloxane;
wherein the weight ratio of component A) to component B) may vary from 99.5/0.5 to 10/90.
2. The composition of claim 1 , wherein the weight ratio of component A) to component B) is about 99.5/0.5.
3. The composition of claim 1 , wherein the phenyl silsesquioxane resin comprises at least 60 mole percent of (C 6 H 5 )SiO 3/2 siloxy units.
4. The composition of claim 1 , wherein the phenyl silsesquioxane resin consists essentially of (C 6 H 5 )SiO 3/2 siloxy units.
5. The composition of claim 1 , wherein the polydiorganosiloxane is polymethylphenylsiloxane.
6. The composition of claim 1 , wherein the polydiorganosiloxane has the formula
(CH 3 ) 3 SiO[(CH 3 ) 2 SiO] m Si(CH 3 ) 3
wherein m is ≧1.
7. The composition of claim 6 , wherein m is an integer from 1 to 200.
8. The composition of claim 1 , wherein the polydiorganosiloxane has the formula
(CH 3 ) 3 SiO[(C 6 H 5 )(CH 3 )SiO] m Si(CH 3 ) 3
wherein m is ≧1.
9. The composition of claim 1 , wherein the polydiorganosiloxane has the formula
(CH 3 )(C 6 H 5 ) 2 SiO[(C 6 H 5 )(CH 3 )SiO] m Si(C 6 H 5 ) 2 (CH 3 )
wherein m is ≧1.
10. The composition of claim 1 , wherein the polydiorganosiloxane has the formula
(CH 3 )(C 6 H 5 )(OH)SiO[(C 6 H 5 )(CH 3 )SiO] m Si(OH)(C 6 H 5 )(CH 3 )
wherein m is ≧1.
11. The composition of claim 1 , wherein the polydiorganosiloxane has the formula
(CH 3 ) 2 (OH)SiO[(C 6 H 5 )(CH 3 )SiO] m Si(OH)(CH 3 ) 2
wherein m is ≧1.
12. The composition of claim 1 , wherein A) and/or B) further comprises a solvent.
13. The composition of claim 1 , wherein B) the organopolysiloxane is a cyclic polydiorganosiloxane.
14. The composition of claim 13 , wherein the cyclic polydiorganosiloxane has the formula:
wherein each R 1 , at each occurrence, is independently a C 1 to C 30 hydrocarbyl.
15. The composition of claim 14 , wherein each R 1 , at each occurrence, is independently methyl or phenyl.
16. A solid film composition comprising a curable composition of claim 15 .
17. The cured product of composition of claim 16 .
18. The solid film compositions of claim 16 , wherein the solid composition has an optical transmittance of at least 95%.
19. The composition of claim 1 , wherein the composition is curable.
20. An LED encapsulant comprising the compositions of claim 1 .
21. A method for increasing the flexibility of a solid resin-linear organosiloxane block copolymer composition comprising combining one or more resin-linear organosiloxane block copolymer compositions and at least one of a phenyl silsesquioxane resin and a polydiorganosiloxane,
wherein the weight ratio of the organosiloxane block copolymer composition to the organopolysiloxane may vary from 90/10 to 10/90; and
wherein the one or more resin-linear organosiloxane block copolymer compositions comprise:
40 to 90 mole percent disiloxy units of the formula [R 1 2 SiO 2/2 ],
10 to 60 mole percent trisiloxy units of the formula [R 2 SiO 3/2 ],
0.5 to 35 mole percent silanol groups [≡SiOH];
wherein:
each R 1 , at each occurrence, is independently a C 1 to C 30 hydrocarbyl,
R 2 , at each occurrence, is independently a C 1 to C 20 hydrocarbyl;
wherein:
the disiloxy units [R 1 2 SiO 2/2 ] are arranged in linear blocks having an average of from 10 to 400 disiloxy units [R 1 2 SiO 2/2 ] per linear block,
the trisiloxy units [R 2 SiO 3/2 ] are arranged in non-linear blocks having a molecular weight of at least 500 g/mole, and at least 30% of the non-linear blocks are crosslinked with each other, each linear block is linked to at least one non-linear block, and
the organosiloxane block copolymer has a weight average molecular weight (M w ) of at least 20,000 g/mole.
22. A method for reducing the viscosity of a solid resin-linear organosiloxane block copolymer composition comprising combining one or more resin-linear organosiloxane block copolymer compositions and at least one of a phenyl silsesquioxane resin and a polydiorganosiloxane,
wherein the weight ratio of the organosiloxane block copolymer composition to the organopolysiloxane may vary from 90/10 to 10/90; and
wherein the one or more resin-linear organosiloxane block copolymer compositions comprise:
40 to 90 mole percent disiloxy units of the formula [R 1 2 SiO 2/2 ],
10 to 60 mole percent trisiloxy units of the formula [R 2 SiO 3/2 ],
0.5 to 35 mole percent silanol groups [≡SiOH];
wherein:
each R 1 , at each occurrence, is independently a C 1 to C 30 hydrocarbyl,
R 2 , at each occurrence, is independently a C 1 to C 20 hydrocarbyl;
wherein:
the disiloxy units [R 1 2 SiO 2/2 ] are arranged in linear blocks having an average of from 10 to 400 disiloxy units [R 1 2 SiO 2/2 ] per linear block,
the trisiloxy units [R 2 SiO 3/2 ] are arranged in non-linear blocks having a molecular weight of at least 500 g/mole, and at least 30% of the non-linear blocks are crosslinked with each other, each linear block is linked to at least one non-linear block, and
the organosiloxane block copolymer has a weight average molecular weight (M w ) of at least 20,000 g/mole.
23. A method for reducing the storage modulus of a solid resin-linear organosiloxane block copolymer composition comprising combining one or more resin-linear organosiloxane block copolymer compositions and at least one of a phenyl silsesquioxane resin and a polydiorganosiloxane,
wherein the weight ratio of the organosiloxane block copolymer composition to the organopolysiloxane may vary from 90/10 to 10/90; and
wherein the one or more resin-linear organosiloxane block copolymer compositions comprise:
40 to 90 mole percent disiloxy units of the formula [R 1 2 SiO 2/2],
10 to 60 mole percent trisiloxy units of the formula [R 2 SiO 3/2 ],
0.5 to 35 mole percent silanol groups [≡SiOH];
wherein:
each R 1 , at each occurrence, is independently a C 1 to C 30 hydrocarbyl,
R 2 , at each occurrence, is independently a C 1 to C 20 hydrocarbyl;
wherein:
the disiloxy units [R 1 2 SiO 2/2 ] are arranged in linear blocks having an average of from 10 to 400 disiloxy units [R 1 2 SiO 2/2 ] per linear block,
the trisiloxy units [R 2 SiO 3/2 ] are arranged in non-linear blocks having a molecular weight of at least 500 g/mole, and at least 30% of the non-linear blocks are crosslinked with each other, each linear block is linked to at least one non-linear block, and
the organosiloxane block copolymer has a weight average molecular weight (M w ) of at least 20,000 g/mole.
24. The method of claim 23 , wherein the storage modulus is reduced to a value ranging from about 0.5 to about 50 kPa.