Method for preparing a sol-gel resin
View Patent ↗Disclosed are processes for preparing sol-gel resins from phenolic compounds and aldehydes. The process includes reacting an hydroxylated benzene and a catalyst with an aldehyde to form a liquid storage stable intermediate. The storage stable intermediate may then be stored for a period of time before being utilized in a process to prepare the sol-gel resin, in either monolith or particle form, by subsequently reacting the intermediate with an hydroxylated benzene and a catalyst.
1. A method for preparing a sol-gel resin comprising:
introducing a first hydroxylated benzene and a first catalyst into a reaction vessel;
introducing an aldehyde into the reaction vessel to form a first liquid reaction mixture;
reacting the first liquid reaction mixture for a period of time sufficient to consume a portion of the first hydroxylated benzene;
adding a second catalyst the first liquid reaction mixture to form a liquid storage stable intermediate having a viscosity;
introducing a second hydroxylated benzene to the liquid storage stable intermediate to form a second liquid reaction mixture; and
transferring the second reaction mixture to a container and curing at a temperature of from 45 to 95° C. to form a sol-gel resin.
2. The method of claim 1 wherein the liquid storage stable intermediate is stable for at least 3 days at a temperature of between about 2° C. to about 25° C. while exhibiting a change in the viscosity of less than 100% as measured by Brookfield viscosity at 25° C.
3. The method of claim 1 wherein the first hydroxylated benzene comprises phenol and the second hydroxylated benzene comprises resorcinol.
4. The method of claim 3 wherein the first hydroxylated benzene consists essentially of phenol and the second hydroxylated benzene consists essentially of resorcinol.
5. The method of claim 3 wherein up to 85 mole % of a total amount of the first hydroxylated benzene and second hydroxylated benzene comprises phenol.
6. The method of claim 1 wherein the first catalyst is a basic catalyst.
7. The method of claim 1 wherein the second catalyst is an acid catalyst.
8. The method of claim 1 wherein the aldehyde is introduced to control a reaction exotherm over a period of time sufficient to consume from about 20% to about 75% of the aldehyde.
9. The method of claim 1 wherein the molar ratio of a total of the first and the second hydroxylated benzene to the aldehyde is about 0.20 to about 0.75.
10. The method of claim 1 wherein the sol-gel resin is cured at a temperature of from about 50° C. to about 100° C.
11. The method of claim 1 free of a step to isolate the sol-gel resin from a suspending liquid reaction media.
12. The method of claim 1 free of reaction phases that are immiscible or insoluble with each other.
13. A method for preparing a sol-gel resin comprising:
introducing a first hydroxylated benzene and a first catalyst into a reaction vessel;
introducing an aldehyde into the reaction vessel to form a first liquid reaction mixture;
reacting the first reaction mixture for a period of time sufficient to consume a portion of the first hydroxylated benzene;
adding a second catalyst to the first reaction mixture to form a liquid storage stable intermediate having a viscosity;
introducing a second hydroxylated benzene to the liquid storage stable intermediate to form a second liquid reaction mixture; and
agitating the second liquid reaction mixture for a period of time sufficient to form the sol-gel resin in a particulate form.
14. The method of claim 13 wherein the second liquid reaction mixture is agitated under conditions sufficient to produce the sol-gel resin having an average particle size of from about 0.5 mm to about 20 mm.
15. The method of claim 13 wherein the second liquid reaction mixture is agitated at a temperature between about 25° C. to about 120° C.
16. The method of claim 13 wherein the liquid storage stable intermediate is stable for at least 3 days at a temperature of between about 2° C. to about 25° C. while exhibiting a change in the viscosity of less than 100% as measured by Brookfield viscosity at 25° C.
17. The method of claim 13 wherein the first hydroxylated benzene comprises phenol and the second hydroxylated benzene comprises resorcinol.
18. The method of claim 17 wherein the first hydroxylated benzene consists essentially of phenol and the second hydroxylated benzene consists essentially of resorcinol.
19. The method of claim of claim 17 wherein up to 85 mole % of a total amount of the first hydroxylated benzene and second hydroxylated benzene comprises phenol.
20. The method of claim 13 wherein the first catalyst is a basic catalyst.
21. The method of claim 13 wherein the second catalyst is an acid catalyst.
22. The method of claim 13 wherein the aldehyde is introduced to control a reaction exotherm over a period of time sufficient to consume from about 20% to about 75% of the aldehyde.
23. The method of claim 13 wherein the molar ratio of a total of the first and the second hydroxylated benzene to the aldehyde is about 0.20 to about 0.75.
24. The method of claim 13 wherein the sol-gel resin is cured at a temperature of from about 50° C. to about 100° C.
25. The method of claim 13 free of a step to isolate the sol-gel resin from a suspending liquid reaction media.
26. The method of claim 13 free of reaction phases that are immiscible or insoluble with each other.