US4658000A — Polyacrylamide adhesive for fixing the sorbent la…

Claim 1

Independent Claim 187 words

A process for preparing a polyacrylamide adhesive having a density of 1.004 to 1.008 g/ml of and a relative viscosity of 2≦η≦20, suitable for the appropriate fixing of fine particle sorbent layers, based on organic or inorganic compounds, and supplied with a bound or unbound nonpolar phase, used in high pressure single layer and multilayer chromatographic procedures, which comprises the following steps: (a) polymerizing in an aqueous mixture, acrylamide and N,N-methylene-bis-acrylamide, in the presence of a catalyst, at 21° to 30° C., wherein the aqueous mixture contains 1.6 to 2.5% acrylamide and 0.6 to 1.0% N,N-methylene-bis-acrylamide repsectively to obtain a polyacrylamide gel; (b) homogenizing the polyacrylamide gel to obtain an opaline solution containing acrylamide-N,N-methylene-bis-acrylamide copolymer; (c) fractionally precipitating the acrylamide-N,N-methylene-bis-acrylamide copolymer from the opaline solution with a water-soluble solvent to obtain a curdy precipitate containing the desired fraction of the copolymer and a supernatant liquid containing undesired monomers and oligomers; (d) removing the curdy precipitate and pulpifying same by adding water to form again a homogeneous opaline solution; and (e) repeating steps (c) and (d) several times to obtain a homogenous opaline composition of the polyacrylamide adhesive.

Claim 2

Dependent Claim 187 words

A process for preparing a polyacrylamide adhesive having a density of 1.004 to 1.008 g/ml of and a relative viscosity of 2≦η≦20, suitable for the appropriate fixing of fine particle sorbent layers, based on organic or inorganic compounds, and supplied with a bound or unbound nonpolar phase, used in high pressure single layer and multilayer chromatographic procedures, which comprises the following steps: (a) polymerizing in an aqueous mixture, acrylamide and N,N-methylene-bis-acrylamide, in the presence of a catalyst, at 21° to 30° C., wherein the aqueous mixture contains 1.6 to 2.5% acrylamide and 0.6 to 1.0% N,N-methylene-bis-acrylamide repsectively to obtain a polyacrylamide gel; (b) homogenizing the polyacrylamide gel to obtain an opaline solution containing acrylamide-N,N-methylene-bis-acrylamide copolymer; (c) fractionally precipitating the acrylamide-N,N-methylene-bis-acrylamide copolymer from the opaline solution with a water-soluble solvent to obtain a curdy precipitate containing the desired fraction of the copolymer and a supernatant liquid containing undesired monomers and oligomers; (d) removing the curdy precipitate and pulpifying same by adding water to form again a homogeneous opaline solution; and (e) repeating steps (c) and (d) several times to obtain a homogenous opaline composition of the polyacrylamide adhesive.

Claim 3

Dependent Claim 26 words

A process as claimed in claim 1 which comprises using from 1.9 to 2.2% and from 0.8 to 1.0% aqueous solution of acrylamide and N,N'-methylene-bis-acrylamide, respectively.

Claim 4

Dependent Claim 23 words

A process as claimed in claim 1 which comprises using N,N,N',N'-tetramethylethylene diamine or 3-diethylamino propionitrile, each in combination with ammonium peroxydisulphate as catalyst.

Claim 5

Dependent Claim 17 words

A process as claimed in claim 1 which comprises starting the polymerization reaction preferably at 22 C°.

Claim 6

Dependent Claim 23 words

A process as claimed in claim 1 which comprises using ethanol, methanol or acetone for precipitating the desired fraction from the gel matrix.

Claim 7

Dependent Claim 185 words

A polyacrylamide adhesive having a density of 1.004 to 1.008 g/ml and a relative viscosity of 2≦η≦20, suitable for the appropriate fixing of fine particle sorbent layers, based on organic or inorganic compounds, and supplied with a bound or unbound nonpolar phase, used in high-pressure single layer and multilayer chromatographic procedures, prepared by a process which comprises the following steps: (a) polymerizing in an aqueous mixture, acrylamide and N,N-methylene-bis-acrylamide, in the presence of a catalyst, at 21° to 30° C., wherein the aqueous mixture contains 1.6 to 2.5% acrylamide and 0.6 to 1.0% N,N-methylene-bis-acrylamide respectively to obtain a polyacrylamide gel; (b) homogenizing the polyacrylamide gel to obtain an opaline solution containing acrylamide-N,N-methylene-bis-acrylamide copolymer; (c) fractionally precipitating the acryalmide-N,N'-methylene-bis-acrylamide copolymer from the opaline solution with a water-soluble solvent to obtain a curdy precipitate containing the desired fraction of the copolymer and a supernatant liquid containing undesired monomers and oligomers; (d) removing the curdy precipitate and pulpifying same by adding water to form again a homogeneous opaline solution; and (e) repeating steps (c) and (d) several times to obtain a homogenous opaline composition of the polyacrylamide adhesive.

Claim 8

Dependent Claim 185 words

A polyacrylamide adhesive having a density of 1.004 to 1.008 g/ml and a relative viscosity of 2≦η≦20, suitable for the appropriate fixing of fine particle sorbent layers, based on organic or inorganic compounds, and supplied with a bound or unbound nonpolar phase, used in high-pressure single layer and multilayer chromatographic procedures, prepared by a process which comprises the following steps: (a) polymerizing in an aqueous mixture, acrylamide and N,N-methylene-bis-acrylamide, in the presence of a catalyst, at 21° to 30° C., wherein the aqueous mixture contains 1.6 to 2.5% acrylamide and 0.6 to 1.0% N,N-methylene-bis-acrylamide respectively to obtain a polyacrylamide gel; (b) homogenizing the polyacrylamide gel to obtain an opaline solution containing acrylamide-N,N-methylene-bis-acrylamide copolymer; (c) fractionally precipitating the acryalmide-N,N'-methylene-bis-acrylamide copolymer from the opaline solution with a water-soluble solvent to obtain a curdy precipitate containing the desired fraction of the copolymer and a supernatant liquid containing undesired monomers and oligomers; (d) removing the curdy precipitate and pulpifying same by adding water to form again a homogeneous opaline solution; and (e) repeating steps (c) and (d) several times to obtain a homogenous opaline composition of the polyacrylamide adhesive.

Claim 9

Dependent Claim 24 words

The adhesive of claim 6 prepared by using from 1.9 to 2.2% and from 0.8 to 1.0% aqueous solution of acrylamide and N,N'-methylene-bis-acrylamide, respectively.

Claim 10

Dependent Claim 24 words

The adhesive as claimed in claim 6 prepared by using N,N,N',N'-tetramethyl ethylene diamine or 3-diethylamino propionitrile, each in combination with ammonium peroxydisulphate as catalyst.

Claim 11

Dependent Claim 17 words

The adhesive as claimed in claim 6 prepared by starting the polymerization reaction preferably at 22 C.°.

Claim 12

Dependent Claim 25 words

An adhesive as claimed in claim 6 prepared by using acetone, methanol or ethanol for the precipitating of the desired fraction from the gel matrix.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1990-04-13	1990-10-13	1991-04-14	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1994-04-13	1994-10-13	1995-04-14	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1998-04-13	1998-10-13	1999-04-14	$7700.00	Window Closed / Lapsed

Polyacrylamide adhesive for fixing the sorbent layers of overpressured, one-and multilayer-chromatographic plates and a process for the preparation thereof

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