US4764498A — Silica-containing shaped articles and a process f…

Claim 1

Independent Claim 131 words

A process for preparing silica-containing shaped articles, comprising applying a mass selected from the group consisting of silica sol, a mixture containing water, silica sol and waterglass and a mixture containing water and waterglass to a base material while the temperature of the base material is, at the start of the application of the silica sol or of the mixture, below the softening point of the base material and, as the application of the silica sol or of the mixture proceeds, above the boiling temperature of water, and the silica sol or the mixture is added in such a way that the water evaporates rapidly and the water content of the base material is always less than 5% by weight, whereby to surround the base material with a porous silica-containing layer.

Claim 2

Dependent Claim 131 words

A process for preparing silica-containing shaped articles, comprising applying a mass selected from the group consisting of silica sol, a mixture containing water, silica sol and waterglass and a mixture containing water and waterglass to a base material while the temperature of the base material is, at the start of the application of the silica sol or of the mixture, below the softening point of the base material and, as the application of the silica sol or of the mixture proceeds, above the boiling temperature of water, and the silica sol or the mixture is added in such a way that the water evaporates rapidly and the water content of the base material is always less than 5% by weight, whereby to surround the base material with a porous silica-containing layer.

Claim 3

Dependent Claim 51 words

A process according to claim 1, wherein the base material is composed of an inorganic material and at least at the surface of the base material, has an absorbency of less than 10 g of water per 100 g and a BET surface area of less than 5 m 2 /g.

Claim 4

Dependent Claim 33 words

A process according to claim 2, wherein the temperature of the base material is within a range of 105° to 800° C. during the application of the silica sol or of the mixture.

Claim 5

Dependent Claim 86 words

A process according to claim 1, wherein the base material is composed of an organic material and the temperature of the base material at the start of the application of the silica sol or of the mixture is kept below its softening point, as the application of silica sol or mixture proceeds the process is carried out at temperatures within a range of 105° to 220° C., and the base material is then removed by heating to temperatures within the range of 200° to 1,300° C.

Claim 6

Dependent Claim 31 words

A process according to claim 1, wherein silica sol or a mixture is applied until a silica-containing layer having a thickness within a range of 10 to 3000 um has formed.

Claim 7

Dependent Claim 61 words

A process according to claim 1, wherein catalytically active substances or precursors thereof are applied together with silica sol or with the mixture containing silica or a mixture is first applied which produces a silica-containing layer free of catalytically active substances or precursors thereof and solutions or suspensions of catalytically active substances or precursors thereof are then introduced into the layer.

Claim 8

Dependent Claim 59 words

A silica-containing shaped article comprising a base material surrounded by a firmly adhering layer consisting essentially of porous silica and a catalytically active substance or precursor thereof, said base layer having an absorbency less than 10 g of water per 100 g, a BET surface area below 5 m 2 /g and a thickness of 10 to 3,000 μm.

Claim 9

Dependent Claim 59 words

A silica-containing shaped article comprising a base material surrounded by a firmly adhering layer consisting essentially of porous silica and a catalytically active substance or precursor thereof, said base layer having an absorbency less than 10 g of water per 100 g, a BET surface area below 5 m 2 /g and a thickness of 10 to 3,000 μm.

Claim 10

Dependent Claim 15 words

A silica-containing shaped article according to claim 7, wherein the base material comprises magnesium silicate.

Claim 11

Dependent Claim 23 words

A silica-containing shaped article according to claim 7, which further comprises a second layer disposed between the base material and said first layer.

Claim 12

Dependent Claim 44 words

A silica-containing shaped article according to claim 7, wherein the base material is a solid polymeric material selected from the group consisting of polystyrenes, polycarbonates, polyolefins, cellulose, cellulose derivatives, polyurethanes, polyacrylonitriles, acrylonitrilestyrene-butadiene copolymers, polyesters, polyvinyl chlorides, polyfluoroethylenes, polyfluoroethylene derivatives, polyamides, epoxy resins and polycondensates.

Claim 13

Dependent Claim 25 words

A silica-containing shaped article according to claim 7, wherein the base material has an absorbency of less than 5 g of water per 100 g.

Claim 14

Dependent Claim 19 words

A silica-containing shaped article according to claim 7, wherein the thickness of the layer is 20 to 2,000 μm.

Claim 15

Dependent Claim 19 words

A silica-containing shaped article according to claim 7, wherein the thickness of the layer is 1 to 100 μm.

Claim 16

Dependent Claim 21 words

A process according to claim 1, which further comprises applying finely pulverulent and/or water-insoluble silica with said silica sol and/or mixtures.

Claim 17

Dependent Claim 42 words

A process according to claim 1, wherein the base material is a solid polymeric material selected from the group consisting of polystyrenes, polycarbonates, polyolefins, cellulose, cellulose derivatives, polyurethanes, polyacrylonitriles, acrylonitrilestyrene-butadiene copolymers, polyesters, polyvinyl chlorides, polyfluoroethylenes, polyfluoroethylene derivatives, polyamides, epoxy resins and polycondensates.

Claim 18

Dependent Claim 51 words

A process according to claim 1, wherein said silica sol contains 15 to 45% by weight SiO 2 , below 0.5% by weight of Na 2 O, has a pH of 3.4 to 10, a density of 1.09 to 1.33 g/cm 3 and a particle size of 7 to 30 μm.

Claim 19

Dependent Claim 120 words

A process according to claim 1, wherein said mass is selected from the group consisting of (a) 10 to 80% by weight of silica sol and an amount to add up to 100% by weight of finely pulverulent, water-insoluble silica, (b) 10 to 60% by weight of waterglass and an amount to add up to 100% by weight of finely pulverulent, water-insoluble silica, and (c) 10 to 90% by weight of silica sol and waterglass, the waterglass content being at most 60% by weight of the mixture, and an amount to add up to 100% by weight of finely pulverulent, water-insoluble silica, in each of (a), (b), (c) the % by weight calculated and relative to anhydrous SiO 2 .

Claim 20

Dependent Claim 30 words

A process according to claim 1, wherein the mass is relative to all silica constituents therein and calculated as anhydrous SiO 2 , 30 to 95% by weight, of water.

Claim 21

Dependent Claim 22 words

A process according to claim 1, wherein said base material is an organic material and said temperature is 105° to 300° C.

Claim 22

Dependent Claim 48 words

A process according to claim 1, wherein said base material is an inorganic material charge and the base material is heated to 200° to 250° C. and then sprayed with said mass until the temperature of the charge falls to 105° to 150° C. and then sprayed again.

Claim 23

Dependent Claim 184 words

A silica-containing shaped article produced by a process comprising applying a mass selected from the group consisting of silica sol, a mixture containing water, silica sol and waterglass, a mixture containing water and waterglass and a mixture containing water and silica sol, said silica sol containing finely pulverulent water-insoluble silica having a primary particle size in a range of 1 to 200 nm and an agglomerate size withing a range of 0.5 to 100 μm, to a base material having an absorbency of less than 10 g of water per 100 g and a BET surface area of less than 5 m 2 /g, while the temperature of the base material is, at the start of the application of the silica sol or the mixtures, below the softening point of the base material and, as the application of the silica sol or of the mixtures proceed, above the boiling temperature of water, and adding the silica sol or the mixtures in such a way that the water evaporates rapidly and the water content of the base material is always less than 5% by weight.

Claim 24

Dependent Claim 184 words

A silica-containing shaped article produced by a process comprising applying a mass selected from the group consisting of silica sol, a mixture containing water, silica sol and waterglass, a mixture containing water and waterglass and a mixture containing water and silica sol, said silica sol containing finely pulverulent water-insoluble silica having a primary particle size in a range of 1 to 200 nm and an agglomerate size withing a range of 0.5 to 100 μm, to a base material having an absorbency of less than 10 g of water per 100 g and a BET surface area of less than 5 m 2 /g, while the temperature of the base material is, at the start of the application of the silica sol or the mixtures, below the softening point of the base material and, as the application of the silica sol or of the mixtures proceed, above the boiling temperature of water, and adding the silica sol or the mixtures in such a way that the water evaporates rapidly and the water content of the base material is always less than 5% by weight.

Claim 25

Dependent Claim 28 words

A process according to claim 14, wherein the silica has a primary particle size of 1 to 200 nm an an agglomerate size of 0.5 to 100 μm.

Claim 26

Dependent Claim 11 words

A process according to claim 14, wherein the silica is kieselguhr.

Claim 27

Dependent Claim 26 words

A process according to claim 1, wherein the silica sol or one of said mixtures is applied at a temperature above the boiling point of water.

Claim 28

Dependent Claim 92 words

A process according to claim 1, which further comprises applying a porosity-forming agent with said silica sol and/or mixtures, said porosity-forming agent selected from the group consisting of activated carbon, carbon black, graphite ammonium salts, aliphatic alcohols of the empirical formula C n H 2n+2 O, aliphatic dihydroxy, trihydroxy and polyhydroxy compounds, aliphatic carboxylic acids of the empirical formula C n H 2n O 2 , aliphatic dicarboxylic acids of the empirical formula C n H 2n-2 O 4 , higher aliphatic carboxylic acids and sugars and readily and completely decomposable polymers.

Claim 29

Dependent Claim 56 words

A process according to claim 25, wherein the porosity-forming agent is selected from the group consisting of ammonium carbonate, ammonium hydrogencarbonate, ammonium nitrate, ammonium acetate, ammonium formate, ammonium oxalate, ethylene glycol, glycerol, sugar alcohols, acetic acid, propionic acid, oxalic acid, sodium acetate, malonic acid, ascorbic acid, tartaric acid, citric acid, glucose, sucrose, starch, cellulose and polystyrene.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1991-08-16	1992-02-15	1992-08-16	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1995-08-16	1996-02-15	1996-08-16	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1999-08-16	2000-02-15	2000-08-16	$7700.00	Window Closed / Lapsed

Silica-containing shaped articles and a process for their preparation

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