US4374814A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for removal of gaseous formaldehyde from the atmosphere
Assignee: Pure Air Inc
•
Filing: 1981-04-28
•
Granted: 1983-02-22
•
Expires: 2001-04-28
Abstract
Abstract A method for purifying air by removing gaseous formaldehyde under ambient conditions, by bringing the air in contact with a solid shaped composition consisting essentially of one or more polyhydric water-soluble polymers and ambient moisture, in the absence and in the presence of a solid substrate.
Inventors
- 👤 Norman G. Gaylord
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 14:10
CPC Classifications
B; B01; B01D; B01D53/00; B01D53/34; B01D53/46; B01D53/72; B01D53/02
Claims Analysis
Total Claims: 29
Claim 1
Independent Claim
37 words
A method for purifying air by removal of gaseous formaldehyde which consists in permitting the air to come in contact with a solid shaped composition consisting essentially of one or more polyhydric water-soluble polymers and ambient moisture.
Claim 2
Independent Claim
37 words
A method for purifying air by removal of gaseous formaldehyde which consists in permitting the air to come in contact with a solid shaped composition consisting essentially of one or more polyhydric water-soluble polymers and ambient moisture.
Claim 3
Dependent Claim
27 words
The method according to claim 1 wherein said polyhydric water-soluble polymer is selected from the group consisting of polysaccharides, modified polysaccharides and hydroxyl-containing addition and condensation polymers.
Claim 4
Dependent Claim
23 words
The method according to claim 2 wherein said polysaccharide is selected from the group consisting of plant polysaccharides, and polysaccharides and microbial polysaccharides.
Claim 5
Dependent Claim
32 words
The method according to claim 1 wherein said modified polysaccharide is selected from the group consisting of cellulose ethers, starch ethers, cellulose esters, starch esters, cellulose graft copolymers and starch graft copolymers.
Claim 6
Dependent Claim
21 words
The method according to claim 4 wherein said cellulose ether is selected from the group consisting of alkylcelluloses, hydroxyalkylcelluloses and carboxyalkylcelluloses.
Claim 7
Dependent Claim
21 words
The method according to claim 5 wherein said hydroxyalkylcellulose is selected from the group consisting of hydroxyethylcellulose, hydroxypropylcellulose, hydroxypropylmethylcellulose and carboxymethylhydroxyethylcellulose.
Claim 8
Dependent Claim
11 words
The method according to claim 5 wherein said alkylcellulose is methylcellulose.
Claim 9
Dependent Claim
12 words
The method according to claim 3 wherein said plant polysaccharide is starch.
Claim 10
Dependent Claim
11 words
The method according to claim 5 wherein said carboxyalkylcellulose is carboxymethylcellulose.
Claim 11
Dependent Claim
32 words
The method according to claim 2 wherein said hydroxyl-containing addition polymer is selected from the group consisting of poly(vinyl alcohol), partially hydrolyzed poly(vinyl acetate), poly(hydroxyalkyl acrylates), poly(hydroxyalkyl methacrylates) and hydroxyalkylated poly(vinyl alcohol).
Claim 12
Dependent Claim
18 words
The method according to claim 4 wherein said cellulose and starch graft copolymers are acrylic acid graft copolymers.
Claim 13
Dependent Claim
18 words
The method according to claim 1 wherein said solid shaped composition contains 0-70% by weight of a plasticizer.
Claim 14
Dependent Claim
27 words
The method according to claim 12 wherein said plasticizer is a low molecular weight polyol selected from the group consisting of glycerol, glycols, polyalkylene glycols and alkanolamines.
Claim 15
Dependent Claim
18 words
The method according to claim 1 wherein said solid shaped composition contains 0-5% by weight of a catalyst.
Claim 16
Dependent Claim
14 words
The method according to claim 1 wherein said solid shaped composition is partially crosslinked.
Claim 17
Independent Claim
40 words
The method for purifying air by removal of gaseous formaldehyde which consists in permitting the air to come in contact with a solid substrate which contains a coating consisting essentially of one or more polyhydric water-soluble polymers and ambient moisture.
Claim 18
Independent Claim
40 words
The method for purifying air by removal of gaseous formaldehyde which consists in permitting the air to come in contact with a solid substrate which contains a coating consisting essentially of one or more polyhydric water-soluble polymers and ambient moisture.
Claim 19
Dependent Claim
28 words
The method according to claim 16 wherein said solid substrate is selected from the group consisting of particulate solids, foams, fibrous solids and woven and nonwoven fibrous webs.
Claim 20
Dependent Claim
27 words
The method according to claim 16 wherein said polyhydric water-soluble polymer is selected from the group consisting of polysaccharides, modified polysaccharides and hydroxyl-containing addition and condensation polymers.
Claim 21
Dependent Claim
12 words
The method according to claim 16 wherein said coating is partially crosslinked.
Claim 22
Dependent Claim
25 words
The method according to claim 1 wherein the air is permitted to come in contact with a solid shaped composition in an air recirculating system.
Claim 23
Dependent Claim
14 words
The method according to claim 20 wherein said solid shaped composition is partially crosslinked.
Claim 24
Independent Claim
44 words
A method for purifying air by removal of gaseous formaldehyde which consists in permitting the air to come in contact with a mixture of a solid absorbent and a solid shaped composition consisting essentially of one or more polyhydric water-soluble polymers and ambient moisture.
Claim 25
Independent Claim
44 words
A method for purifying air by removal of gaseous formaldehyde which consists in permitting the air to come in contact with a mixture of a solid absorbent and a solid shaped composition consisting essentially of one or more polyhydric water-soluble polymers and ambient moisture.
Claim 26
Dependent Claim
13 words
The method according to claim 22 wherein the solid absorbent is activated carbon.
Claim 27
Dependent Claim
27 words
The method according to claim 22 wherein the polyhydric water-soluble polymer is selected from the group consisting of polysaccharides, modified polysaccharides and hydroxyl-containing addition and condensation polymers.
Claim 28
Dependent Claim
14 words
The method according to claim 22 wherein said solid shaped composition is partially crosslinked.
Claim 29
Dependent Claim
27 words
The method according to claim 22 wherein said solid shaped composition consists of a solid substrate coated with one or more polyhydric water-soluble polymers and ambient moisture.
References Cited (Backward Citations)
US2049608A
Cited
US3898038A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-02-21 | 1986-08-23 | 1987-02-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-02-21 | 1990-08-23 | 1991-02-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-02-21 | 1994-08-23 | 1995-02-22 | $7700.00 | Window Closed / Lapsed |