EP0050167A1
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EP
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Process for making a chromatographic-column packing having a bonded organosiloxane coating, and process for making a chromatographic separation
Assignee: Dow Chemical Co
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Filing: 1980-10-20
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Granted: —
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Expires: 2000-10-20
Abstract
Abstract improved packings for columns useful in gas chromatography are made by a multistep process whereby polysiloxane molecules having various organic substituents are chemically bonded to the surface of a siliceous support. The process comprises one or more cycles of successive reactions with an activated support surface of silicon tetrachloride, an organic dichlorosilane, silicon tetrachloride a second time, a polysiloxane polyol, with intermediate hydrolyses where appropriate to provide reactive terminal silanol groups and a final capping reaction with an organic monochlorosilane. The packing as so prepared is further improved by coating with a conventional stationary phase.
Inventors
- 👤 Terry John Nestrick
- 👤 Rudolph Herman Stehl
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 04:56
CPC Classifications
B; B01; B01J; B01J20/00; B01J20/02; B01J20/10; B01J20/103; B01J20/14; B01J20/22; B01J20/26; B01J20/262; B01J20/28; B01J20/28002; B01J20/28004; B01J20/281; B01J20/286; B01J20/30; B01J20/3092; B01J20/32; B01J20/3202; B01J20/3204; B01J20/3214; B01J20/3225; B01J20/3227; B01J20/3231; B01J20/3242; B01J20/3244; B01J20/3246; B01J20/3268; B01J20/3272; B01J20/3278; C; C08; C08G; C08G83/00; C08G83/001; B01J2220/00; B01J2220/50; B01J2220/58
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
252 words
A process for making a chromatographic column packing by chemically bonding a siloxane polymer coating to the surface of a siliceous solid, comprising the steps of: (a) reacting by contacting an acid-activated siliceous surface with SiCl 4 , thereby causing substantial chlorosilylation of said surface, (b) reacting by contacting the chlorosilylated surface with water vapor until essentially all of the chlorosilyl groups have been hydrolyzed to hydroxysilyl groups, (c) reacting by contacting the hydrolyzed surface with excess dichlorosilane of the formula RR'SiCl 2 wherein R and R' each represent a methyl, ethyl, or vinyl radical for a time sufficient to react at least the major proportion of the hydroxysilyl groups to form corresponding disubstituted chlorosilyl groups, (d) reacting by contacting the reacted product of (c) with water vapor until essentially all of the disubstituted chlorosilyl groups have been hydrolyzed to corresponding disubstituted hydroxysilyl groups, (e) reacting by contacting the hydrolyzed product of (d) with SiCl 4 for a time sufficient to react substantially all of said disubstituted hydroxysilyl groups to form silyloxy chlorosilyl groups, and (f) reacting by contacting the chlorosilylated product of (e) with a molar excess over said silyloxy chlorosilyl groups of a siloxane polymer polyol in the liquid state, said polyol having a molecular weight of at least about 230 and having a molecular structure consisting essentially of repeating units of the formula thereby reacting essentially all of said silyloxy chlorosilyl groups with said polyol to form pendant polyol residues having at least one terminal hydroxyl group per residue.
Claim 2
Dependent Claim
252 words
A process for making a chromatographic column packing by chemically bonding a siloxane polymer coating to the surface of a siliceous solid, comprising the steps of: (a) reacting by contacting an acid-activated siliceous surface with SiCl 4 , thereby causing substantial chlorosilylation of said surface, (b) reacting by contacting the chlorosilylated surface with water vapor until essentially all of the chlorosilyl groups have been hydrolyzed to hydroxysilyl groups, (c) reacting by contacting the hydrolyzed surface with excess dichlorosilane of the formula RR'SiCl 2 wherein R and R' each represent a methyl, ethyl, or vinyl radical for a time sufficient to react at least the major proportion of the hydroxysilyl groups to form corresponding disubstituted chlorosilyl groups, (d) reacting by contacting the reacted product of (c) with water vapor until essentially all of the disubstituted chlorosilyl groups have been hydrolyzed to corresponding disubstituted hydroxysilyl groups, (e) reacting by contacting the hydrolyzed product of (d) with SiCl 4 for a time sufficient to react substantially all of said disubstituted hydroxysilyl groups to form silyloxy chlorosilyl groups, and (f) reacting by contacting the chlorosilylated product of (e) with a molar excess over said silyloxy chlorosilyl groups of a siloxane polymer polyol in the liquid state, said polyol having a molecular weight of at least about 230 and having a molecular structure consisting essentially of repeating units of the formula thereby reacting essentially all of said silyloxy chlorosilyl groups with said polyol to form pendant polyol residues having at least one terminal hydroxyl group per residue.
Claim 3
Dependent Claim
21 words
The process of Claim 1 wherein the sequence of steps (a) through (f) is repeated from one to about four times.
Claim 4
Dependent Claim
59 words
The process of Claim 2 wherein steps (a) and (e) are run using gaseous SiCl 4 at about 0°C-300°C, the hydrolyses in steps (b) and (d) are run with water vapor at about 0°C-250°C, the reaction with RR'SiCl2 in step (c) is run at about 0°C-250°C, and the polymer polyol reaction in step (f) is run at about 0°C-300°C.
Claim 5
Dependent Claim
48 words
The process of Claim 2 wherein following the final sequence of steps (a) through (f), the product of the final step (f) is reacted by contacting with a trimethylsilyl capping reagent, thereby etherifying essentially all of the terminal hydroxyl groups on the pendant polyol residues with trimethylsilyl groups.
Claim 6
Dependent Claim
85 words
The process of Claim 2 wherein the product of the final step (f) is reacted in any alternating order at least once with each of the chlorosilylation reagents SiCl 4 and RR"SiCl - where R" is R, phenyl, 2-cyanoethyl, 3-cyanopropyl, or 3,3,3-trifluoropropyl, each such chlorosilylation reaction followed by a hydrolysis step, said chlorosilylation reactions and said hydrolysis steps carried out as defined in steps (a), (c), and (b) respectively, and the final hydrolyzed product thereof is reacted at about 0-300°C with a trimethylsilyl capping reagent.
Claim 7
Dependent Claim
26 words
The process of Claim 5 wherein the capping reagent is gaseous (CH 3 ) 3 SiCl and the capping reaction is carried out at about 50°C-275°C.
Claim 8
Dependent Claim
15 words
The process of Claim 6 wherein R, R' and R" each represent a methyl group.
Claim 9
Dependent Claim
20 words
The process of Claim 6 wherein R and R' each represent a methyl group and R" is a 2-cyanoethyl group.
Claim 10
Dependent Claim
20 words
The process of Claim 6 wherein R and R' each represent a methyl group and R" is a vinyl group.
Claim 11
Dependent Claim
25 words
The process of Claim 4 wherein the trimethylsilyl-capped product is coated with about 0.1-5 percent by weight of at least one polymeric organic stationary phase.
Claim 12
Dependent Claim
31 words
The process of Claim 10 wherein the polymeric organic stationary phase is selected from a polyphenyl sulfone,-a polyphenyl ether, an organopolysiloxane, or a mixture of a polyphenyl sulfone and an organopolysiloxane.
Claim 13
Dependent Claim
63 words
A process for making a chromatographic separation of components contained in a sample which comprises: (a) mixing the vaporized sample with an inert carrier gas, and (b) contacting the sample-carrier gas mixture with the chromatographic column packing produced by the process of Claim 4, said packing being permeable by said mixture and comprising a silica support having a chemically bonded surface coating thereon.
References Cited (Backward Citations)
US3960521A
Cited
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