Composite silicone membranes of high separation efficiency

1. A composite membrane, comprising: a separating membrane layer and a support membrane,

wherein the separating membrane layer comprises a cured mixture of silicone acrylates, the mixture comprising:

from 70 to 90% by weight of a component (A); and

from 10 to 30% by weight of a component (B);

wherein

component (A) is at least one silicone acrylate of Formula I, having a silicon content of on average greater than 29% by weight,

wherein,

a is from 25 to 500,

b is 0,

c is from 0 to 20, and

each R 2 =R 3 , and

component (B) is at least one silicone acrylate of Formula I, having a silicon content of less than 27.5% by weight, wherein,

a is from 1 to 24,

b is from 3 to 25,

c is from 0 to 20, and

each R 2 is R 1 or R 4 ,

each R 1 is independently an alkyl or aryl radical having from 1 to 30 carbon atoms, optionally comprising an ether group, an ester group, an epoxy group, an alcohol group, or a combination thereof,

each R 3 is independently an organic radical comprising one or more acrylate groups, and

each R 4 is independently a polyether radical.

2. The composite membrane of claim 1 ,

wherein R 3 is of Formula II or III:

d is from 0 to 12,

e is 0 or 1,

f is from 0 to 12,

g is from 0 to 2,

h is from 1 to 3,

g+h=3,

each R 6 is H or an alkyl or aryl radical having 1 to 30 carbon atoms,

each R 7 is a hydrocarbon radical.

3. The composite membrane of claim 1 ,

wherein each R 4 is independently of Formula IV:

—(CH 2 ) i —O—(CH 2 CH 2 O) j —(CH 2 CH(CH 3 )O) k —(CH 2 CHR 8 O) l —R 9   Formula IV,

i is from 0 to 12,

j is from 0 to 50,

k is from 0 to 50,

l is from 0 to 50,

each R 8 independently an alkyl or aryl radical having from 2 to 30 carbon atoms,

each R 9 is independently H, an alkanoyl radical, or an alkyl or aryl radical having from 2 to 30 carbon atoms.

4. The composite silicone membrane of claim 1 , wherein a mass ratio of (A) to (B) is from 10:1 to 1:10.

5. The composite membrane of claim 1 ,

wherein said curing is with a photo-initiator by electromagnetic radiation having a wavelength less than 800 nm, by an electron beam, or by both.

6. The composite membrane of claim 1 ,

wherein the support membrane is at least one solvent persistent porous three-dimensional support structure selected from the group consisting of a nonwoven membrane, a micro-filtration membrane, an ultrafiltration membrane, and a separator.

7. The composite membrane of claim 1 ,

wherein the support membrane comprises at least one porous support material selected from the group consisting of polyacrylonitrile (PAN); polyimide (PI); polyether ether ketone (PEEK); polyvinylidene fluoride (PVDF); polyamide (PA); polyamide-imide (PAI); polyethersulfone (PES); polybenzimidazole (PBI); sulphonated polyether ketone (SPEEK); polyethylen (PE); polypropylen (PP); an inorganic porous material, ceramic membrane, or polymer ceramic membrane obtained from aluminium oxide, titanium dioxide, zirconium dioxide, silicon oxide, titanium nitrite, or a combination thereof; and mixtures, modifications or composites thereof.

8. A process for retaining dissolved molecules, comprising:

retaining dissolved molecules having a molecular weight of less than 2000 g/mol with the composite membrane of claim 1 ,

wherein a retain fraction rate of the retaining is at least 90% by weight.

9. The process of claim 8 ,

wherein the dissolved molecules are a homogeneous catalyst system to be separated from a reaction mixture, a triglyceride to be separated from a solvent having a molecular weight of less than 200 g/mol, an oligomer to be separated from a monomer solution, or a pharmaceutical active ingredient or precursor thereof to be separated from a reaction mixture or solution.

10. The process of claim 9 ,

wherein the dissolved molecules are to be separated from a hydrocarbon with 1 to 8 carbon atoms, an isomer or mixture thereof, or else CO 2 .

11. The process of claim 8 ,

wherein the retaining comprises separating off a molecular weight fraction of less than 1000 g/mol from a solution in n-heptane at 30° C., 30 bar pressure.

12. A process for producing the composite membrane of claim 1 , comprising:

coating a support membrane with the mixture of silicone acrylates, to obtain a coated support membrane, and subsequently

curing the coated support membrane by electromagnetic radiation, electron beam radiation, or both.

13. The composite membrane of claim 2 ,

wherein an R 7 group is —CR 6 2 -.

14. The composite membrane of claim 13 ,

wherein an R 7 group is —CH 2 -.

15. The composite membrane of claim 3 , wherein i is from 3 to 7.

16. The process of claim 12 , wherein curing the coated support membrane comprises curing by electromagnetic radiation having a wavelength less than 800 nm.