US4478891A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of reducing the emission of formaldehyde from particle board bound with carbamide resin
Assignee: Statens Skogsindustrier AB
•
Filing: 1983-07-19
•
Granted: 1984-10-23
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Expires: 2003-07-19
Abstract
Abstract The emission of formaldehyde from particle board bound with carbamide resin is reduced by coating the boards, during their manufacture and subsequent to pressing the same, with at least one ammonium compound which decomposes thermally at the temperature of the boards during the conditioning period, whereafter the boards are stacked and stored for conditioning.
Inventors
- 👤 Anders W. Westling
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 22:56
CPC Classifications
B; B05; B05D; B05D7/00; B05D7/06
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
123 words
A method of reducing the emission of formaldehyde from particle board bound with carbamide resin, wherein subsequent to being pressed the boards are cooled to a temperature of 40°-70° C., then the boards are coated with a concentrated aqueous solution containing (a) at least one ammonium compound selected from the group consisting of ammonium carbonate and ammonium hydrogen carbonate, and (b) urea, and then immediately after coating the boards are stacked for at least one day for conditioning, the weight ratio of urea to said ammonium carbonate being from 1:2 to 1:10, the amount of the ammonia compound being at least 10 g per square meter of board and the amount of urea being at least 5 g per square meter of board.
Claim 2
Independent Claim
123 words
A method of reducing the emission of formaldehyde from particle board bound with carbamide resin, wherein subsequent to being pressed the boards are cooled to a temperature of 40°-70° C., then the boards are coated with a concentrated aqueous solution containing (a) at least one ammonium compound selected from the group consisting of ammonium carbonate and ammonium hydrogen carbonate, and (b) urea, and then immediately after coating the boards are stacked for at least one day for conditioning, the weight ratio of urea to said ammonium carbonate being from 1:2 to 1:10, the amount of the ammonia compound being at least 10 g per square meter of board and the amount of urea being at least 5 g per square meter of board.
Claim 3
Independent Claim
133 words
A method of reducing the emission of formaldehyde from particle board bound with carbamide resin, wherein subsequent to being pressed the boards are cooled to a temperature of 40°-70° C., then the boards are coated with a concentrated aqueous solution containing (a) at least one ammonium compound selected from the group consisting of ammonium carbonate and ammonium hydrogen carbonate, and (b) urea, and then immediately after coating the boards are stacked for at least one day for conditioning, the weight ratio of urea to said ammonium compound being from 1:2 to 1:10, said aqueous solution containing ammonium acetate for regulating the pH, the amount of the ammonia compound being at least 10 g per square meter of board and the amount of urea being at least 5 g per square meter of board.
Claim 4
Independent Claim
133 words
A method of reducing the emission of formaldehyde from particle board bound with carbamide resin, wherein subsequent to being pressed the boards are cooled to a temperature of 40°-70° C., then the boards are coated with a concentrated aqueous solution containing (a) at least one ammonium compound selected from the group consisting of ammonium carbonate and ammonium hydrogen carbonate, and (b) urea, and then immediately after coating the boards are stacked for at least one day for conditioning, the weight ratio of urea to said ammonium compound being from 1:2 to 1:10, said aqueous solution containing ammonium acetate for regulating the pH, the amount of the ammonia compound being at least 10 g per square meter of board and the amount of urea being at least 5 g per square meter of board.
Claim 5
Independent Claim
69 words
A method of reducing the emission of formaldehyde from particle board bound with carbamide resin which comprises the steps of (a) cooling the pressed particle boards to a temperature conventional in conditioning, (b) coating the particle boards with at least one ammonium compound selected from the group consisting of (1) ammonium carbonate, and (2) ammonium hydrogen carbonate, and (c) stacking the coated particle boards in a stack for conditioning.
Claim 6
Independent Claim
69 words
A method of reducing the emission of formaldehyde from particle board bound with carbamide resin which comprises the steps of (a) cooling the pressed particle boards to a temperature conventional in conditioning, (b) coating the particle boards with at least one ammonium compound selected from the group consisting of (1) ammonium carbonate, and (2) ammonium hydrogen carbonate, and (c) stacking the coated particle boards in a stack for conditioning.
Claim 7
Dependent Claim
19 words
A method according to claim 3 wherein the boards are treated with a concentrated solution of said ammonium compound.
Claim 8
Dependent Claim
13 words
A method according to claim 4 wherein the solution is an aqueous solution.
Claim 9
Dependent Claim
18 words
A method according to claim 5 wherein the aqueous solution also contains ammonium acetate for regulating the pH.
Claim 10
Dependent Claim
27 words
A method according to claim 3 wherein the boards are coated with a solution which, in addition to ammonium carbonate or ammonium hydrogen carbonate, also contains urea.
Claim 11
Dependent Claim
27 words
A method according to claim 4 wherein the boards are coated with a solution which, in addition to ammonium carbonate or ammonium hydrogen carbonate, also contains urea.
Claim 12
Dependent Claim
27 words
A method according to claim 5 wherein the boards are coated with a solution which, in addition to ammonium carbonate or ammonium hydrogen carbonate, also contains urea.
Claim 13
Dependent Claim
27 words
A method according to claim 6 wherein the boards are coated with a solution which, in addition to ammonium carbonate or ammonium hydrogen carbonate, also contains urea.
Claim 14
Dependent Claim
20 words
A method according to claim 7 wherein the weight ratio of urea to ammonium compound is from 1:2 to 1:10.
Claim 15
Dependent Claim
20 words
A method according to claim 8 wherein the weight ratio of urea to ammonium compound is from 1:2 to 1:10.
Claim 16
Dependent Claim
20 words
A method according to claim 9 wherein the weight ratio of urea to ammonium compound is from 1:2 to 1:10.
Claim 17
Dependent Claim
20 words
A method according to claim 10 wherein the weight ratio of urea to ammonium compound is from 1:2 to 1:10.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-10-23 | 1988-04-23 | 1988-10-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-10-23 | 1992-04-23 | 1992-10-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-10-23 | 1996-04-23 | 1996-10-23 | $7700.00 | Window Closed / Lapsed |