US4847002A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Improved stabilization of wood preservative solutions and preservation of wood by such solutions
Assignee: Bell Canada Inc
•
Filing: 1987-08-14
•
Granted: 1989-07-11
•
Expires: 2007-08-14
Abstract
Abstract A wood preservative solution comprising water, hexavalent chromium, copper and arsenic can be stabilized against precipitation by the addition of fluorine ion, thereby enhancing the useful life and safety of the solution. Fluoride salts like cerium fluoride, sodium fluoride and calcium fluoride are suitable sources for fluorine ion in such a solution. Wood treated with the preservative solution displays increased penetration, distribution and retention of chromium, copper and arsenic.
Inventors
- 👤 William P. Trumble
- 👤 Cheryl M. Maritan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 03:15
CPC Classifications
B; B27; B27K; B27K3/00; B27K3/16; B27K3/32; B27K3/30; B27K3/52; Y; Y10; Y10S; Y10S428/00; Y10S428/907; Y10T; Y10T428/00; Y10T428/31504; Y10T428/31971; Y10T428/31989; Y10T428/4935; Y10T428/662
Claims Analysis
Total Claims: 57
Claim 1
Independent Claim
80 words
An aqueous wood preservative solution comprising a CCA-type formulation consisting essentially of 33% to 69.3% hexavalent chromium, calculated as Cr 2 O 3 ; 16% to 22% bivalent copper, calculated as CuO; and 14.7% to 48% pentavalent arsenic, calculated as As 2 O 5 ; diluted with water, and an amount of F - ion sufficient to stabilize said solution against precipitation of at least said chromium without retarding conversion of hexavalent chromium to trivalent chromium in a wood matrix.
Claim 2
Dependent Claim
80 words
An aqueous wood preservative solution comprising a CCA-type formulation consisting essentially of 33% to 69.3% hexavalent chromium, calculated as Cr 2 O 3 ; 16% to 22% bivalent copper, calculated as CuO; and 14.7% to 48% pentavalent arsenic, calculated as As 2 O 5 ; diluted with water, and an amount of F - ion sufficient to stabilize said solution against precipitation of at least said chromium without retarding conversion of hexavalent chromium to trivalent chromium in a wood matrix.
Claim 3
Dependent Claim
22 words
A wood preservative solution according to claim 1, wherein said fluorine ion is contributed by a fluoride salt added to said solution.
Claim 4
Dependent Claim
50 words
A wood preservative solution according to claim 2, wherein said preservative solution is the produce of a process comprising the step of diluting a Type C standard CCA solution, as specified in ASTM standard D1625-71, with water to form a 2 to 3% aqueous solution of said standard CCA solution.
Claim 5
Dependent Claim
35 words
A wood preservative solution according to claim 2, wherein said fluoride salt is at least one selected from the group consisting of a rare earth fluoride, an alkaline earth fluoride and an alkaline metal fluoride.
Claim 6
Dependent Claim
26 words
A wood preservative solution according to claim 4, wherein said fluoride salt is selected from the group consisting of cerium fluoride, sodium fluoride and calcium fluoride.
Claim 7
Dependent Claim
14 words
A wood preservative solution according to claim 1, further consisting essentially of polyethylene glycol.
Claim 8
Dependent Claim
25 words
A wood preservative solution according to claim 6, wherein said polyethylene glycol has a molecular weight in the range from about 100 to about 2,000.
Claim 9
Dependent Claim
24 words
A wood preservative solution according to claim 7, wherein said molecular weight range of said polyethylene glycol is from about 500 to about 2,000.
Claim 10
Dependent Claim
64 words
A wood preservative solution according to claim 6, wherein said preservative solution comprises (1) water, (2) about 2 to 3.0% concentration of chromium, copper and arsenic salts or oxides (3) about 0.5% to 10% concentration of a polyethylene glycol having a molecular weight of about 1,000, and (4) between about 0.001 and 0.4% of a fluoride salt contributing said fluorine ion to said solution.
Claim 11
Dependent Claim
25 words
A wood preservative solution according to claim 1, wherein said preservative solution has a pH below about 2.0 and a temperature below about 85° F.%.
Claim 12
Dependent Claim
29 words
A wood preservative solution according to claim 10, wherein said preservative solution has a pH between about 1.7 and 2.0 and a temperature between about 70° and 85° F.
Claim 13
Independent Claim
95 words
A method of treating wood, comprising the step of exposing wood to an aqueous wood preservative solution comprising a CCA-type formulation consisting essentially of 33% to 69.3% hexavalent chromium, calculated as Cr 2 O 3 ; 16% to 22% bivalent copper, calculated as CuO; and 14.7% to 48% pentavalent arsenic, calculated as As 2 O 5 ; diluted with water, and an amount of F - ion sufficient to stabilize said preservative solution against precipitation of at least said chromium and insufficient to retard the conversion of hexavalent chromium to trivalent chromiumin a wood matrix.
Claim 14
Independent Claim
95 words
A method of treating wood, comprising the step of exposing wood to an aqueous wood preservative solution comprising a CCA-type formulation consisting essentially of 33% to 69.3% hexavalent chromium, calculated as Cr 2 O 3 ; 16% to 22% bivalent copper, calculated as CuO; and 14.7% to 48% pentavalent arsenic, calculated as As 2 O 5 ; diluted with water, and an amount of F - ion sufficient to stabilize said preservative solution against precipitation of at least said chromium and insufficient to retard the conversion of hexavalent chromium to trivalent chromiumin a wood matrix.
Claim 15
Dependent Claim
20 words
A method according to claim 12, wherein said fluorine ion is contributed by a fluorine salt added to said solution.
Claim 16
Dependent Claim
49 words
A method according to claim 13, wherein said preservative solution is the product of a process comprising the step of diluting a Type C standard CCA solution, as a specified in ASTM standard D1625-71, with water to form a 2% to 3% aqueous solution of said standard CCA solution.
Claim 17
Dependent Claim
33 words
A method according to claim 13, wherein said fluoride salt is at least one selected from the group consisting of a rare earth fluoride, an alkaline earth fluoride and an alkaline metal fluoride.
Claim 18
Dependent Claim
24 words
A method according to claim 15, wherein said fluoride salt is selected from the group consisting of cerium fluoride, sodium fluoride and calcium fluoride.
Claim 19
Dependent Claim
16 words
A method according to claim 12, wherein said preservative solution further consists essentially of polyethylene glycol.
Claim 20
Dependent Claim
23 words
A method according to claim 17, wherein said polyethylene glycol has a molecular weight in the range from about 100 to about 2,000.
Claim 21
Dependent Claim
23 words
A method according to claim 18, wherein said preservative molecular weight range of said polyethylene glycol is from about 500 to about 2,000.
Claim 22
Dependent Claim
62 words
A method according to claim 17, wherein said preservative solution comprises (1) water, (2) about 2 to 3.0% concentration of chromium, copper and arsenic salts or oxides, (3) about 0.5% to 10% concentration of a polyethylene glycol having a molecular weight of about 1,000 and (4) between about 0.001 and 0.4% of a fluoride salt contributing said fluorine ion to said solution.
Claim 23
Dependent Claim
23 words
A method according to claim 12, wherein said preservative solution has a pH below about 2.0 and a temperature below about 85° F.
Claim 24
Dependent Claim
27 words
A method according to claim 21, wherein said preservative solution has a pH between about 1.7 and 2.0 and a temperature between about 70° and 85° F.
Claim 25
Dependent Claim
95 words
An article of manufacture produced by a process comprising the step of treating wood with a wood preservative solution comprising a CCA-type formulation consisting essentially of 33% to 69.3% hexavalent chromium, calculated as Cr 2 O 3 ; 16% to 22% bivalent copper, calculated as CuO; and 14.7% to 48% pentavalent arsenic, calculated as As 2 O 5 ; diluted with water, and an amount of F - ion sufficient to stabilize said preservative solution against precipitation of at least said chromium without retarding conversion of hexavalent chromium to trivalent chromium in a wood matrix.
Claim 26
Dependent Claim
95 words
An article of manufacture produced by a process comprising the step of treating wood with a wood preservative solution comprising a CCA-type formulation consisting essentially of 33% to 69.3% hexavalent chromium, calculated as Cr 2 O 3 ; 16% to 22% bivalent copper, calculated as CuO; and 14.7% to 48% pentavalent arsenic, calculated as As 2 O 5 ; diluted with water, and an amount of F - ion sufficient to stabilize said preservative solution against precipitation of at least said chromium without retarding conversion of hexavalent chromium to trivalent chromium in a wood matrix.
Claim 27
Dependent Claim
19 words
An article according to claim 23, wherein said wood comprises sapwood into which said preservative solution penetrates substantially completely.
Claim 28
Dependent Claim
21 words
An article according to claim 23, wherein said fluorine ion is contributed by a fluoride salt added to said preservative solution.
Claim 29
Dependent Claim
48 words
An article according to claim 25, wherein said preservative solution is the product of a process comprising the step of diluting a Type C standard CCA solution, as specified in ASTM standard D1625-71, with water to form a 2 to 3% aqueous solution of said standard CCA solution.
Claim 30
Dependent Claim
33 words
An article according to claim 25, wherein said fluoride salt is at least one selected from the group consisting of a rare earth fluoride, an alkaline earth fluoride and an alkaline metal fluoride.
Claim 31
Dependent Claim
24 words
An article according to claim 27, wherein said fluoride salt is selected from the group consisting of cerium fluoride, sodium fluoride and calcium fluoride.
Claim 32
Dependent Claim
16 words
An article according to claim 23, wherein said preservative solution further consists essentially of polyethylene glycol.
Claim 33
Dependent Claim
23 words
An article according to claim 29, wherein said polyethylene glycol has a molecular weight in the range from about 100 to about 2,000.
Claim 34
Dependent Claim
22 words
An article according to claim 30, wherein said molecular weight range of said polyethylene glycol is from about 500 to about 2,000.
Claim 35
Dependent Claim
62 words
An article according to claim 29, wherein said preservative solution comprises (1) water, (2) about 2 to 3.0% concentration of chromium, copper and arsenic salts or oxides, (3) about 0.5% to 10% concentration of a polyethylene glycol having a molecular weight of about 1,000, and (4) between about 0.001 and 0.4% of a fluoride salt contributing said fluorine ion to said solution.
Claim 36
Dependent Claim
23 words
An article according to claim 23 wherein said preservative solution has a pH below about 2.0 and a temperature below about 85° F.
Claim 37
Dependent Claim
27 words
An article according to claim 33, wherein said preservative solution has a pH between about 1.7 and 2.0 and a temperature between about 70° and 85° F.
Claim 38
Independent Claim
82 words
A method for stabilizing a wood preservative solution comprising a CCA-type formulation consisting essentially of 33% to 69.3% hexavalent chromium, calculated as Cr 2 O 3 ; 16% to 22% bivalent copper, calculated as CuO; and 14.7% to 48% pentavalent arsenic, calculated as As 2 O 5 ; diluted with water, comprising the step of adding a source of F - ion to said preservative solution in an amount sufficient to stabilize said preservative solution against precipitation of at least said chromium.
Claim 39
Independent Claim
82 words
A method for stabilizing a wood preservative solution comprising a CCA-type formulation consisting essentially of 33% to 69.3% hexavalent chromium, calculated as Cr 2 O 3 ; 16% to 22% bivalent copper, calculated as CuO; and 14.7% to 48% pentavalent arsenic, calculated as As 2 O 5 ; diluted with water, comprising the step of adding a source of F - ion to said preservative solution in an amount sufficient to stabilize said preservative solution against precipitation of at least said chromium.
Claim 40
Dependent Claim
17 words
A method as claimed in claim 35, wherein said source of fluoride ion comprises a flouride salt.
Claim 41
Dependent Claim
19 words
A method as claimed in claim 36, wherein said fluoride salt has a low solubility in said preservative solution.
Claim 42
Dependent Claim
33 words
A method as claimed in claim 37, wherein said fluoride salt is added to said preservative solution in an amount approximately equal to the solubility of said fluoride salt in said preservative solution.
Claim 43
Dependent Claim
34 words
A method as claimed in claim 36, wherein said fluoride salt is at least one selected from the group consisting of a rare earth fluoride, an alkaline earth fluoride and an alkaline metal fluoride.
Claim 44
Dependent Claim
25 words
A method as claimed in claim 39, wherein said fluoride salt is selected from the group consisting of cerium fluoride, sodium fluoride and calcium fluoride.
Claim 45
Dependent Claim
49 words
A method as claimed in claim 35, wherein said preservative solution is a product of a process comprising the step of diluting a Type C standard CCA solution, as specified in ASTM standard D1625-71, with water to form a 2 to 3% aqueous solution of said standard CCA solution.
Claim 46
Dependent Claim
17 words
A method as claimed in claim 35, wherein said preservative solution further consists essentially of polyethylene glycol.
Claim 47
Dependent Claim
25 words
A method as claimed in claim 42, wherein said polyethylene glycol has a molecular weight in the range of from about 100 to about 2000.
Claim 48
Dependent Claim
15 words
A method as claimed in claim 41, wherein said aqueous solution further comprises polyethylene glycol.
Claim 49
Dependent Claim
20 words
A method as claimed in claim 44, wherein said polyethylene glycol is present at a concentration between 0.5 and 10%.
Claim 50
Dependent Claim
17 words
A method as claimed in claim 41, wherein said source of fluoride ion comprises a fluoride salt.
Claim 51
Dependent Claim
34 words
A method as claimed in claim 46, wherein said fluoride salt is at least one selected from the group consisting of a rare earth fluoride, an alkaline earth fluoride and an alkaline metal fluoride.
Claim 52
Dependent Claim
27 words
A method as claimed in claim 47, wherein said fluoride salt is at least one from the group consisting of cerium fluoride, sodium fluoride and calcium fluoride.
Claim 53
Dependent Claim
23 words
A method as claimed in claim 48, wherein said fluoride salt is cerium fluoride which is present in concentration up to about 0.4%.
Claim 54
Dependent Claim
17 words
A method as claimed in claim 42, wherein said source of fluoride ion comprises a fluorine salt.
Claim 55
Dependent Claim
34 words
A method as claimed in claim 50, wherein said fluoride salt is at least one selected from the group consisting of a rare earth fluoride, an alkaline earth fluoride and an alkaline metal fluoride.
Claim 56
Dependent Claim
27 words
A method as claimed in claim 51, wherein said fluoride salt is at least one from the group consisting of cerium fluoride, sodium fluoride and calcium fluoride.
Claim 57
Dependent Claim
24 words
A method as claimed in claim 52, wherein said fluoride salt is cerium fluoride which is present in a concentration up to about 0.4%.
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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) | 1992-07-10 | 1993-01-09 | 1993-07-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-07-10 | 1997-01-09 | 1997-07-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-07-10 | 2001-01-09 | 2001-07-11 | $7700.00 | Window Closed / Lapsed |