US4090000A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for treating cellulosic material
Assignee: Individual
•
Filing: 1976-01-15
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Granted: 1978-05-16
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Expires: 1996-01-15
Abstract
Abstract A technique is provided for employing an aqueous solution to treat a cellulosic or other substrate with a water-insoluble preservative such as a polychlorophenol and the like. The treatment solution is formed of water, a soluble polychlorophenate, and a suitable acid-former which, after a predetermined delay interval sufficient to allow adequate treatment with the polychlorophenate, progressively effects in in situ precipitation of the insoluble polychlorophenol on the substrate to be protected. The extent of the delay interval, as well as the extent of the precipitation time, may be regulated as a function of temperature, the excess alkalinity of the treatment solution, and the particular acid-former employed.
Inventors
- 👤 David B. Hatcher
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 19:12
CPC Classifications
C; C09; C09D; C09D5/00; C09D5/14; A; A01; A01N; A01N31/00; A01N31/08; A01N31/10; B; B27; B27K; B27K3/00; B27K3/02; B27K3/0278; B27K3/34; B27K3/38; B27K3/40; B27K3/50
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
138 words
A method of treating wood with a polyhalophenol of the class consisting of polybromophenols and polychlorophenols by means of an aqueous solution, comprising the steps of preparing an aqueous solution of a water-soluble alkaline salt of the polyhalophenol, said solution containing an acid-former which undergoes a reaction in such solution to liberate an acidic substance which displaces the polyhalophenol from said salt, said reaction being on which proceeds only gradually at ordinary temperatures, impregnating wood, with said solution while said salt is still in solution, and then maintaining the wood under conditions at which said reaction proceeds to liberate a sufficient amount of said acidic substance to cause the polyhalophenol to precipitate, the proportion of said acid-former being sufficient so that said reaction causes precipitation of at least a substantial proportion of the polyhalophenol contained in said salt.
Claim 2
Independent Claim
138 words
A method of treating wood with a polyhalophenol of the class consisting of polybromophenols and polychlorophenols by means of an aqueous solution, comprising the steps of preparing an aqueous solution of a water-soluble alkaline salt of the polyhalophenol, said solution containing an acid-former which undergoes a reaction in such solution to liberate an acidic substance which displaces the polyhalophenol from said salt, said reaction being on which proceeds only gradually at ordinary temperatures, impregnating wood, with said solution while said salt is still in solution, and then maintaining the wood under conditions at which said reaction proceeds to liberate a sufficient amount of said acidic substance to cause the polyhalophenol to precipitate, the proportion of said acid-former being sufficient so that said reaction causes precipitation of at least a substantial proportion of the polyhalophenol contained in said salt.
Claim 3
Dependent Claim
45 words
A method according to claim 1 wherein the aqueous solution of a water-soluble alkaline salt of a polyhalophenol also contains a sufficient excess of a base to neutralize an initial portion of the liberated acidic substance, so as to delay the precipitation of the polyhalophenol.
Claim 4
Dependent Claim
16 words
A method according to claim 1 wherein the water-soluble alkaline salt is a salt of pentachlorophenol.
Claim 5
Dependent Claim
31 words
A method according to claim 1 wherein the wood is maintained at an elevated temperature after being impregnated with the aqueous solution, to accelerate the reaction which liberates an acidic substance.
Claim 6
Dependent Claim
24 words
A method according to claim 1 wherein the molar ratio of the acid-former to the alkaline salt in the solution is greater than 1:1.
References Cited (Backward Citations)
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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) | 1981-05-15 | 1981-11-14 | 1982-05-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-05-15 | 1985-11-14 | 1986-05-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-05-15 | 1989-11-14 | 1990-05-16 | $7700.00 | Window Closed / Lapsed |