Process for the preparation of solid solventless MQ resins
View Patent ↗The present invention relates generally to a novel process for making a solid solventless MQ resin comprising the steps of (1)(A) feeding at least one MQ resin dispersed in a volatile solvent into an extrusion device, (2) removing the volatile solvent to form a solid solventless MQ resin; and (3) recovering the solid solventless MQ resin, provided steps (1) to (3) are completed without the addition of a linear silicone fluid.
1. A process for producing a solid solventless MQ resin comprising the steps of
(1)(A) feeding at least one MQ resin dispersed in a volatile solvent into an extrusion device, where each MQ resin has the general formula (I) R 1 n (R 2 O) b SiO (4-n-b/2) where each R 1 is monovalent and independently selected from hydrogen, alkyl, alkenyl, oximo, aryl, carbinol, anhydride, epoxy, carboxyl, ether, polyether, amide, and alkyl amino groups, which R 1 groups may be the same or different, with the proviso that at least sixty mole percent of R 1 groups are methyl, R 2 is hydrogen or a monovalent C1 to C4 alkyl group, on average n is from 1.1 to 1.6, and b is such that group (R 2 O) is 1 to 10 weight percent of the MQ resin, said MQ resins having a number average molecular weight (Mn) between 1,500 and 7,000;
(2) removing the volatile solvent to form a solid solventless MQ resin; and
(3) recovering the solid solventless MQ resin,
provided steps (1) to (3) are completed without the addition of a linear silicone fluid having a general formula (II): (R′ 3 SiO 1/2 ) x (R′ 2 SiO 2/2 ) y (R′SiO 3/2 ) z where x and y are positive numerical values and z is 0 or a positive numerical value with the provisos that x+y+z=1, y/(x+y+z)>0.8 and R′ is a functional or nonfunctional, substituted or unsubstituted organic radical, and the DP is greater than 10.
2. The process of claim 1 where on average n is from 1.1 to 1.5.
3. The process of claim 2 where the solid solventless MQ resin recovered from step (3) has a bulk density of 0.4 to 0.9 g/cm 3 .
4. The process of claim 3 further comprising (1)(B) co-feeding into the extrusion device 5 to 30 weight percent based on total resin solids content of at least one T based resin with the general formula R 3 n′ (R 2 O) b′ SiO (4-n′-b′/2) where R 3 is a C1 to C8 hydrocarbon group, on average n′ is from 0.8 to 1.2, and b′ is such that group (R 2 O) is 1 to 20 weight percent of the T based resin, said T based resin having a Mn between 1500 and 10,000.
5. The process of claim 1 where on average n is from 1.3 to 1.5.
6. The process of claim 5 where the solid solventless MQ resin recovered from step (3) has a bulk density of 0.55 to 0.75 g/cm 3 .
7. The process of claim 1 where the extrusion device is a single screw extruder, a twin screw extruder, or an injection molding devices.
8. The process of claim 1 where such process is a continuous process or a batch process.
9. A process for producing a solid solventless MQ resin comprising the steps of
(1)(A) feeding at least one MO resin dispersed in a volatile solvent into an extrusion device, where each MQ resin has the general formula (I) R 1 n (R 2 O) b SiO (4-n-b/2) where each R 1 is monovalent and independently selected from hydrogen, alkyl, alkenyl, oximo, aryl, carbinol, anhydride, epoxy, carboxyl, ether, polyether, amide, and alkyl amino groups, which R 1 groups may be the same or different, with the proviso that at least sixty mole percent of R 1 groups are methyl, R 2 is hydrogen or a monovalent C1 to C4 alkyl group, on average n is from 1.1 to 1.6, and b is such that group (R 2 O) is 1 to 10 weight percent of the MQ resin, said MQ resins having a number average molecular weight (Mn) between 1,500 and 7,000,
(1)(B) co-feeding into the extrusion device 0.1 to 50 weight percent based on total resin solids content of at least one T based resin with the general formula R 3 n′ (R 2 O) b′ SiO (4-n′-b′/2) where R 3 is a C1 to C8 hydrocarbon group, on average n′ is from 0.8 to 1.2, and b′ is such that group (R 2 0 ) is 1 to 20 weight percent of the T based resin, said T based resin having a Mn between 1500 and 10,000;
(2) removing the volatile solvent to form a solid solventless MQ resin; and
(3) recovering the solid solventless MQ resin, provided steps (1) to (3) are completed without the addition of a linear silicone fluid.
10. The process of claim 9 where R 3 is a propyl group.
11. The process of claim 10 where on average n′ is from 0.9 to 1.1.
12. The process of claim 9 where on average n is from 1.1 to 1.5.
13. The process of claim 12 where the solid solventless MQ resin recovered from step (3) has a bulk density of 0.4 to 0.9 g/cm 3 .
14. The process of claim 13 wherein (1)(B) comprises co-feeding into the extrusion device 5 to 30 weight percent based on total resin solids content of at least one T based resin with the general formula R 3 n′ (R 2 O) b′ SiO (4-n′-b/2) .
15. The process of claim 9 where on average n is from 1.3 to 1.5.
16. The process of claim 15 where the solid solventless MQ resin recovered from step (3) has a bulk density of 0.55 to 0.75 g/cm 3 .
17. The process of claim 16 wherein (1)(B) comprises co-feeding into the extrusion device 5 to 15 weight percent based on total resin solids content of at least one T based resin with the general formula R 3 n′ (R 2 O) b′ SiO (4-n′-b/2) .
18. The process of claim 9 where the solid solventless MQ resin recovered from step (3) has a bulk density greater than 0.35 g/cm 3 .
19. The process of claim 9 , where the linear silicone fluid has a general formula (II): (R′ 3 SiO ½ ) x (R′ 2 SiO 2/2 ) y (R′SiO 3/2 ) z where x and y are positive numerical values and z is 0 or a positive numerical value with the provisos that x+y+z=1, y/(x+y+z) >0.8 and R′ is a functional or nonfunctional, substituted or unsubstituted organic radical, and the DP is greater than 10.