PROCESS FOR TREATING CATALYST PRECURSORS
The invention relates to a process for treating a substantially water-containing amino-functional, polymeric catalyst precursor while retaining the inner porous structure thereof and the outer spherical form thereof to form a catalyst, in which the catalyst precursor is treated at mild temperatures and under reduced pressure to prepare a catalyst having a water content below 2.5% by weight. The process is preferably integrated into an industrial scale process for preparing dichlorosilane, monosilane, silane, or solar silicon or semiconductor silicon from silanes.
1 . A process for producing a catalyst, the process comprising:
treating a water-comprising, amino-functional, polymeric, organic catalyst precursor at a temperature below 200° C. and under reduced pressure, to obtain a catalyst having a water content below 2.5% by weight.
2 . The process of claim 1 , wherein the treating is carried out with a dried gas or gas mixture under reduced pressure.
3 . The process of claim 1 , wherein the catalyst precursor is substantially solvent-free.
4 . The process of claim 1 , further comprising, after the treating, increasing the pressure by breaking vacuum with at least one selected from the group consisting of an inert gas and air.
5 . The process of claim 1 , further comprising, during the treating, agitating at least one selected from the group consisting of the catalyst precursor and the catalyst.
6 . The process of claim 1 , wherein the catalyst precursor comprises a tert-amino-functional divinylbenzene-styrene copolymer or a quaternary-ammonium-functional divinylbenzene-styrene copolymer.
7 . The process of claim 1 , wherein the catalyst substantially retains at least one selected from the group consisting of an inner structure and an outer structure of the catalyst precursor.
8 . The process of claim 1 , further comprising, prior to the treating:
washing a crude catalyst with water, to form the catalyst precursor.
9 . The process of claim 1 , wherein the catalyst is suitable for dismutating at least one selected from the group consisting of HSiCl 3 , H 2 SiCl 2 , and H 3 SiCl.
10 . The process of claim 1 , the treating is effected in a temperature range from −196° C. to 175° C.
11 . The process of claim 1 , wherein the reduced pressure is in a range from 0.001 mbar to 1012 mbar.
12 . The process of claim 1 , the treating is effected in an apparatus comprising:
a vessel;
a first device for charging the apparatus;
optionally, a second device for emptying the apparatus, and
a third device for removing a liquid or a gaseous substance.
13 . The process according of claim 12 , wherein the vessel further comprises at least one selected from the group consisting of a heater and a cooler.
14 . The process of claim 10 , wherein the apparatus is suitable for operation under elevated pressure, standard pressure, and reduced pressure.
15 . The process of claim 10 , wherein the vessel further comprises a stirrer, the vessel is rotatable, or both.
16 . The process of claim 10 , the apparatus further comprises:
a paddle dryer, a filter dryer, or a stirred reactor comprising a vacuum system;
at least one selected from the group consisting of a heater, and a cooler; and
an inert gas supply.
17 . A process for producing a chlorosilane, the process comprising:
dismutating a chlorosilane with a catalyst prepared by the process of claim 1 , to obtain a dismutated silane.
18 . The process of claim 17 , wherein the dismutated silane is at least one selected from the group consisting of dichlorosilane, monochlorosilane, and monosilane, and the chlorosilane a trichlorosilane or silicon tetrachloride.
19 . The process of claim 8 , further comprising, after to the treating:
increasing the pressure by breaking vacuum with an inert gas.
20 . The process of claim 1 , wherein the treating is effected in a temperature range from 20° C. to 95° C.