CA1147505A - Wood preservative and method of use thereof - Google Patents
Wood preservative and method of use thereofInfo
- Publication number
- CA1147505A CA1147505A CA000360158A CA360158A CA1147505A CA 1147505 A CA1147505 A CA 1147505A CA 000360158 A CA000360158 A CA 000360158A CA 360158 A CA360158 A CA 360158A CA 1147505 A CA1147505 A CA 1147505A
- Authority
- CA
- Canada
- Prior art keywords
- preservative
- copper
- solution
- wood
- percent
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
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Classifications
-
- A—HUMAN NECESSITIES
- A01—AGRICULTURE; FORESTRY; ANIMAL HUSBANDRY; HUNTING; TRAPPING; FISHING
- A01N—PRESERVATION OF BODIES OF HUMANS OR ANIMALS OR PLANTS OR PARTS THEREOF; BIOCIDES, e.g. AS DISINFECTANTS, AS PESTICIDES OR AS HERBICIDES; PEST REPELLANTS OR ATTRACTANTS; PLANT GROWTH REGULATORS
- A01N59/00—Biocides, pest repellants or attractants, or plant growth regulators containing elements or inorganic compounds
- A01N59/16—Heavy metals; Compounds thereof
-
- A—HUMAN NECESSITIES
- A01—AGRICULTURE; FORESTRY; ANIMAL HUSBANDRY; HUNTING; TRAPPING; FISHING
- A01N—PRESERVATION OF BODIES OF HUMANS OR ANIMALS OR PLANTS OR PARTS THEREOF; BIOCIDES, e.g. AS DISINFECTANTS, AS PESTICIDES OR AS HERBICIDES; PEST REPELLANTS OR ATTRACTANTS; PLANT GROWTH REGULATORS
- A01N59/00—Biocides, pest repellants or attractants, or plant growth regulators containing elements or inorganic compounds
- A01N59/16—Heavy metals; Compounds thereof
- A01N59/20—Copper
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B27—WORKING OR PRESERVING WOOD OR SIMILAR MATERIAL; NAILING OR STAPLING MACHINES IN GENERAL
- B27K—PROCESSES, APPARATUS OR SELECTION OF SUBSTANCES FOR IMPREGNATING, STAINING, DYEING, BLEACHING OF WOOD OR SIMILAR MATERIALS, OR TREATING OF WOOD OR SIMILAR MATERIALS WITH PERMEANT LIQUIDS, NOT OTHERWISE PROVIDED FOR; CHEMICAL OR PHYSICAL TREATMENT OF CORK, CANE, REED, STRAW OR SIMILAR MATERIALS
- B27K3/00—Impregnating wood, e.g. impregnation pretreatment, for example puncturing; Wood impregnation aids not directly involved in the impregnation process
- B27K3/16—Inorganic impregnating agents
- B27K3/22—Compounds of zinc or copper
Landscapes
- Life Sciences & Earth Sciences (AREA)
- Chemical & Material Sciences (AREA)
- Agronomy & Crop Science (AREA)
- Inorganic Chemistry (AREA)
- Pest Control & Pesticides (AREA)
- Plant Pathology (AREA)
- Health & Medical Sciences (AREA)
- Engineering & Computer Science (AREA)
- Dentistry (AREA)
- General Health & Medical Sciences (AREA)
- Wood Science & Technology (AREA)
- Zoology (AREA)
- Environmental Sciences (AREA)
- Chemical And Physical Treatments For Wood And The Like (AREA)
- Agricultural Chemicals And Associated Chemicals (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
Novel preservative solutions are disclosed which are suitable for use in the treatment of wood.
The preservatives are comprised of aqueous solutions of copper and zinc salts of weak acids such as acetic acid, butyric acid, or propionic acid.
Novel preservative solutions are disclosed which are suitable for use in the treatment of wood.
The preservatives are comprised of aqueous solutions of copper and zinc salts of weak acids such as acetic acid, butyric acid, or propionic acid.
Description
~:147505 BACKGROUND OF THE INVENTION
The present invention deals with preserva-tives for wood and other organic materials such as paper products, textiles and leather.
The preservative of the present invention is based on the use of compounds of copper and zinc. The preservative is intended to provide a permanent protec-tion. It is therefore important that the protecting agents be resistant to and not converted by outside influences such as air, moisture and sunlight. In this respect copper and zinc are unsurpassed in contrast to organic compounds which initially can provide effective protection but are gradually converted to ineffective compounds.
Copper and zinc compounds have been used previously as preservatives. For example, copper sul-phate has been used in the preservation of wood poles. However, since copper sulphate rapidly attacks iron, it has not been possible to employ pressure treatment of wood in iron cylinders. Instead a simpler treating method, i.e., sap displacement, has been used for the introduction of the preservative into the wood. In spite of the fact that the copper sulphate is soluble and the wood is eventually in contact with the soil, effective preservation has been obtained since copper is an effective preservative and the soluble copper salt is not completely leached out from the wood but to a certain extent becomes fixed in the wood.
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,. .
11475~5 Zinc chloride has also been used previously.
In spite of its corrosiveness, it has been possible to treat wood with zinc chloride by pressure treatment in iron cylinders. The salt provides an effective allround protection when the wood is subjected to weak and not strong attack.
Zinc provides a less effective but perhaps a more allround protection than copper. Zinc chloride is also fixed to some extent in the wood but not to the same extent as copper.
DETAILED DESCRIPTION OF THE INVENl ION
The present invention is directed to the use of copper and zinc in a more effective way than before. This is made possible by combining the metals with a weak acid instead of a strong acid. Acetic acid or still weaker acids such as propionic or butyric acid can be used as can numerous other organic or inorganic acids having the same relative strength. A weak acid is an acid with about the same as or lower ionization constant than acetic acid (K =
1.75 x 10 5). It is advantageous to employ an acid which easily and readily evaporates. m e use of copper or zinc acetates or comparable copper or zinc compounds formed with other weak acids besides acetic acid enables an improved fixation to be obtained and enables the corrosion problems to be solved. Preservation treatments with such preservatives ~; gives a long-last:ing protection and causes few environmental problems.
According to the invention there is provided a preservative for wood or similar organic materia s consisting essentially of an aqueous solution of boric acid and a pre-` servative material selected from the group consisting of a copper or zinc salt acetate or mixtures thereof.
~475V5 Copper compounds can be used alone to provide againstmarine borers. A mixture of copper and zinc compounds can be used in ordinary aqueous preservative solutions, comprised, for instance, of a minor part copper and a major part zinc. The reason for this is that the zinc will provide the preservative with a more all-around preservative effect. Zinc salts may also be used to provide a colorless preservative.
me preservatives of the present invention can be mo-dified to enhance their effectiveness. For example, a minor amount of a strong acid in the form of a sulphate of a metal such as zinc or copper can be introduced. Generally, the amount of the sulphate which is employed will range from about 0.1 to 0.5 percent by weight based on the weight of the solution. mis means that the preservative solution willbe somewhat more acidic and thereby the evaporation of the acetic acid will be enhanced.
Boric acid is preferably used in an amount ranging from about 0.2 to about 0.6 percent by weight based on the solu-tion. The same effect is thus obtained to some degree as when a stronger acid is introduced. Boric acid is a weak acid but it remains in solution for a long period of time and will not eva-porate. The greatest advantage with respect to the introduction of boric acid is, however, to obtain an increased and still more all around effect of the preservative. After the wood has been dried for a period of time a certain fixation of the boric acid will take ~'.
E~' - 3--J~
.~
:
place. The use of boric acid is also advantageous since it is an excellent anti-corrosion agent.
In the preservative of the present invention it is also possible to emulgate one or more oils in order to obtain an increased protection against ~ois-ture. The amount of oil employed can be varied within wide ranges. Such oils, if employed, are generally present in a higher amount than the preservative. Such oils can, for instance, comprise from 5 to 10 or even up to 20 percent of the weight of the solution.
The oils to be emulgated can he of different kinds. If a simple water repellant effect is desired, a high boiling paraffin oil containing an amount of paraffin or wax may be used. If the preservative treatment is to be followed by a coloring of the wood, the emulsion must have another character. In this case it must not leave "undried" products which can "bleed"
through the color-layer. In such cases drying oils have to be introduced into the emulsion. Such an emul-sion can contain paraffin oil or other non-drying oils such as rape oil fish oil, together with an amount of a drying oi~ such as linseed oil. The amount of ~inseed oil or other drying oil can he increased to provide an adequate drying result. The amount of the drying oil employed may range up to about 100 percent.
It is possible to obtain good fi~ation results with the preservative of the present invention of such a kind that they can be easily utilized for practice. In order to demonstrate the advantages of 11~75~)5 the present invention a number of leachinq tests employing copper acetate are set forth below In the following tests 2 and 4 grams of saw dust derived from the sap wood of pine have been treated and penetrated with 4 milliliters of aqueous copper acetate solution of varying strengths. The treated saw dust was thereafter stored in different ways and then subjected to leaching to determine the relative fixation of the preservative in the wood. The amount of copper remaining after leaching was deter-mined by analysis.
RE~TS OF L~ING T~
Amount Cu in Solution 0.3 0.3 0.5 0.6 ].0 1.0 in percent by weight An~unt solution in mls 4 4 4 4 4 4 unt saw dust in gms 4 2 4 2 4 2 Remaining amount Cu in saw dust after leaching, in percent Storing, 2 hours 64 45 38.5 29 30 19 without drying Storing, 72 h~urs 71.553 49.5 32 34 19.5 without drying Storing, 72 hours 81.563 55 45.5 40 29.5 without drying and 264 hours with drying Storing, 72 hours 84.570 64 56.5 48 44 without drying and 1008 hours with drying 11~750S
It is highly unexpected to achieve such a high rate of fixation with an inexpensive salt such as copper acetate. No special solvents or fixing agents are required. The zinc in zinc salts such as zinc acetate is also fixed in the wood in a similar way as copper but generally not to the same extent.
The fixation of the copper in the wood seems to occur in the following way. The copper acetate, which by itself is a stable compound, converts in con-tact with the wood whereby a great amount of the coPper radical is fastly fixed. The fixation may thereafter be enhanced by storing the treated wood in an undried condition and may be still further increased if the wood is later dried. The fixation takes place as the wood dries. During the drying step acetic acid (or, correspondingly, any other weak acid which is used) evaporates from the wood and the unleached copper (or zinc) which remains in the wood is extremely hard fixed and can be cons~dered as unleachable.
It may be possible to further improve the fixation process by adding an active catalytic sub-stance to the preservative such as potassium iodide.
The addition of such a substance may as a rule not be done in the solid salt mixture but first in the preser-vative solution prior to the wood preservative treat-ment.
The results obtained in the above tests can be improved upon in actual practice since the storage time employed may be many times longer and will thus 1~475()5 increase the degree of ~ixation. The ]eaching of the metal compound will thus, as a rule, not be so severe.
It is also noted from the above examples that the degree of fixation substantially corresponds to the amount of preservative introduced per unit weight of wood. A small content of preservative is fixed to a higher degree than a preservative having a higher con-centration. Such a property is the opposite to the effect of the fixation of negative radicals as arsenic, fluorine and boron compounds. Surprisingly, the fixed amounts exceed the amounts needed to provide adequate preservative protection. In the examples a sPecific amount of preservative is introduced and distributed in a specific amount of saw dust. If the amount of pre-servative is high, a part of it remains leachable or soluble. In practice the soluble or leachable portion of the metal can diffuse to the inner region of the wood which contains less preservative. The distribu-tion obtained by a pressure treatment normally result-ing in a decreasing amount towards the inner region of the wood can thus be improved due to the properties of the preservative.
The corrosion question is of little conse-quence when zinc salts such as zinc acetate are used.
The situation differs if copper salts such as copper acetate are used. The presence of boric acid will, as a rule, control the corrosion problem. Diluted solu-tions of copper acetate are corrosive to some extent ~1~75()5 while more concentrated solutions are not so corro-sive. The corrosion can, however, be kept under con-trol quite easily. The addition of about 0.01 percent of sodium nitrite or about 0.03 percent ammonium ace-tate to a 1 percent solution of copper acetate thus overcomes the corrosion problem.
Such protection can also be obtained with other additives. It is interesting to note that the addition of a small surplus of acetic acid to the aque-ous copper acetate solution does not increase the cor-rosion. A surplus of about 0.05 percent acetic acid has even demonstrated a certain corrosion protective effect. If the excess amount of acetic acid is increased to about 0.10 percent, the corrosion will again increase. A surplus of acetic acid can be avoided by the addition of, for example, about 0.01 percent sodium nitrite to the solution.
In the full cell treatment of Swedish pine when, as a rule, 300 litres of preservative solution may be introduced per cubic meter of wood, the follow-ing concentrations of the preservative solut;on have been found to be suitable. If a copper salt is used alone the concentration thereof preferably is about 0.
percent and may range from about 0.3 to about 0.6 per-cent based on the copper. The concentration of zinc salt alone will be about 0.6 to 1.0 percent zinc based on the zinc. Generally the same concentrations can be used for mixtures of copper and zinc salts. A treat-ment solution comprising such a mixture can, for ,'~
1~75~5 example, contain about 0.12 to about 0.24 percent by weight copper and 0.36-0.60 percent by weight zinc based on the weight of the copper and zinc. These mixtures advantageously contain higher percentages of zinc than copper as previously stated.
~ ethods other than the full cell treatment can, of course, be used in the preservation of wood.
The strength of the solution must then be adapted in view of the amount of solution introduced into the wood by the different treatments so that the wood receives an adequate amount of preservative. The following guidelines can be generally followed. When treating wood according to the Lowry method, the woofl will receive about half the amount of solution as by fu11 cell treatment, e.g., about 1~0 instead of 300 litres per cubic meter of wood. In order to introduce the same amount of preservative into the wood, a double strength solution is used in the Lowry treatment as opposed to that employed in the full cell treatment.
In the diffusion treatment of wood employing strong solutions, the preservative of the present invention provides special advantages. The preserva-tive will diffuse into the wet (green~ wood whereupon a certain amount of the preservative is fixed and the rest further diffuses into the wood where it will be fixed upon drying.
The preservative has heen described ahove in form of water solutions. It is also use~ in this way.
_9_ The preservative is manufactured and distri-buted as a solid salt, which before use is dissolved to desired strength.
Examples of the preservative in form of solid salts are given in Table I. The figures are in percent by weight.
1147S~1S
~BIE I
ExemPlary I~redients of Preservative (% by wt of preservatives) Preser- ~
vative Cu/Acetate Zn Acetate Boric Acid NaNitrite ZnSulfate In order to be clear it may be said that copper acetate contains 35 percent copper and zinc acetate contains 35.6 percent zinc. This mean~ that a solution containing 0.3 percent copper is made up of 0.86 percent copper acetate. The specification dis-cusses percent copper or zinc as the metals are the protective agents. Boric acid is signified by H3BO3.
, ' ,
The present invention deals with preserva-tives for wood and other organic materials such as paper products, textiles and leather.
The preservative of the present invention is based on the use of compounds of copper and zinc. The preservative is intended to provide a permanent protec-tion. It is therefore important that the protecting agents be resistant to and not converted by outside influences such as air, moisture and sunlight. In this respect copper and zinc are unsurpassed in contrast to organic compounds which initially can provide effective protection but are gradually converted to ineffective compounds.
Copper and zinc compounds have been used previously as preservatives. For example, copper sul-phate has been used in the preservation of wood poles. However, since copper sulphate rapidly attacks iron, it has not been possible to employ pressure treatment of wood in iron cylinders. Instead a simpler treating method, i.e., sap displacement, has been used for the introduction of the preservative into the wood. In spite of the fact that the copper sulphate is soluble and the wood is eventually in contact with the soil, effective preservation has been obtained since copper is an effective preservative and the soluble copper salt is not completely leached out from the wood but to a certain extent becomes fixed in the wood.
qF
,. .
11475~5 Zinc chloride has also been used previously.
In spite of its corrosiveness, it has been possible to treat wood with zinc chloride by pressure treatment in iron cylinders. The salt provides an effective allround protection when the wood is subjected to weak and not strong attack.
Zinc provides a less effective but perhaps a more allround protection than copper. Zinc chloride is also fixed to some extent in the wood but not to the same extent as copper.
DETAILED DESCRIPTION OF THE INVENl ION
The present invention is directed to the use of copper and zinc in a more effective way than before. This is made possible by combining the metals with a weak acid instead of a strong acid. Acetic acid or still weaker acids such as propionic or butyric acid can be used as can numerous other organic or inorganic acids having the same relative strength. A weak acid is an acid with about the same as or lower ionization constant than acetic acid (K =
1.75 x 10 5). It is advantageous to employ an acid which easily and readily evaporates. m e use of copper or zinc acetates or comparable copper or zinc compounds formed with other weak acids besides acetic acid enables an improved fixation to be obtained and enables the corrosion problems to be solved. Preservation treatments with such preservatives ~; gives a long-last:ing protection and causes few environmental problems.
According to the invention there is provided a preservative for wood or similar organic materia s consisting essentially of an aqueous solution of boric acid and a pre-` servative material selected from the group consisting of a copper or zinc salt acetate or mixtures thereof.
~475V5 Copper compounds can be used alone to provide againstmarine borers. A mixture of copper and zinc compounds can be used in ordinary aqueous preservative solutions, comprised, for instance, of a minor part copper and a major part zinc. The reason for this is that the zinc will provide the preservative with a more all-around preservative effect. Zinc salts may also be used to provide a colorless preservative.
me preservatives of the present invention can be mo-dified to enhance their effectiveness. For example, a minor amount of a strong acid in the form of a sulphate of a metal such as zinc or copper can be introduced. Generally, the amount of the sulphate which is employed will range from about 0.1 to 0.5 percent by weight based on the weight of the solution. mis means that the preservative solution willbe somewhat more acidic and thereby the evaporation of the acetic acid will be enhanced.
Boric acid is preferably used in an amount ranging from about 0.2 to about 0.6 percent by weight based on the solu-tion. The same effect is thus obtained to some degree as when a stronger acid is introduced. Boric acid is a weak acid but it remains in solution for a long period of time and will not eva-porate. The greatest advantage with respect to the introduction of boric acid is, however, to obtain an increased and still more all around effect of the preservative. After the wood has been dried for a period of time a certain fixation of the boric acid will take ~'.
E~' - 3--J~
.~
:
place. The use of boric acid is also advantageous since it is an excellent anti-corrosion agent.
In the preservative of the present invention it is also possible to emulgate one or more oils in order to obtain an increased protection against ~ois-ture. The amount of oil employed can be varied within wide ranges. Such oils, if employed, are generally present in a higher amount than the preservative. Such oils can, for instance, comprise from 5 to 10 or even up to 20 percent of the weight of the solution.
The oils to be emulgated can he of different kinds. If a simple water repellant effect is desired, a high boiling paraffin oil containing an amount of paraffin or wax may be used. If the preservative treatment is to be followed by a coloring of the wood, the emulsion must have another character. In this case it must not leave "undried" products which can "bleed"
through the color-layer. In such cases drying oils have to be introduced into the emulsion. Such an emul-sion can contain paraffin oil or other non-drying oils such as rape oil fish oil, together with an amount of a drying oi~ such as linseed oil. The amount of ~inseed oil or other drying oil can he increased to provide an adequate drying result. The amount of the drying oil employed may range up to about 100 percent.
It is possible to obtain good fi~ation results with the preservative of the present invention of such a kind that they can be easily utilized for practice. In order to demonstrate the advantages of 11~75~)5 the present invention a number of leachinq tests employing copper acetate are set forth below In the following tests 2 and 4 grams of saw dust derived from the sap wood of pine have been treated and penetrated with 4 milliliters of aqueous copper acetate solution of varying strengths. The treated saw dust was thereafter stored in different ways and then subjected to leaching to determine the relative fixation of the preservative in the wood. The amount of copper remaining after leaching was deter-mined by analysis.
RE~TS OF L~ING T~
Amount Cu in Solution 0.3 0.3 0.5 0.6 ].0 1.0 in percent by weight An~unt solution in mls 4 4 4 4 4 4 unt saw dust in gms 4 2 4 2 4 2 Remaining amount Cu in saw dust after leaching, in percent Storing, 2 hours 64 45 38.5 29 30 19 without drying Storing, 72 h~urs 71.553 49.5 32 34 19.5 without drying Storing, 72 hours 81.563 55 45.5 40 29.5 without drying and 264 hours with drying Storing, 72 hours 84.570 64 56.5 48 44 without drying and 1008 hours with drying 11~750S
It is highly unexpected to achieve such a high rate of fixation with an inexpensive salt such as copper acetate. No special solvents or fixing agents are required. The zinc in zinc salts such as zinc acetate is also fixed in the wood in a similar way as copper but generally not to the same extent.
The fixation of the copper in the wood seems to occur in the following way. The copper acetate, which by itself is a stable compound, converts in con-tact with the wood whereby a great amount of the coPper radical is fastly fixed. The fixation may thereafter be enhanced by storing the treated wood in an undried condition and may be still further increased if the wood is later dried. The fixation takes place as the wood dries. During the drying step acetic acid (or, correspondingly, any other weak acid which is used) evaporates from the wood and the unleached copper (or zinc) which remains in the wood is extremely hard fixed and can be cons~dered as unleachable.
It may be possible to further improve the fixation process by adding an active catalytic sub-stance to the preservative such as potassium iodide.
The addition of such a substance may as a rule not be done in the solid salt mixture but first in the preser-vative solution prior to the wood preservative treat-ment.
The results obtained in the above tests can be improved upon in actual practice since the storage time employed may be many times longer and will thus 1~475()5 increase the degree of ~ixation. The ]eaching of the metal compound will thus, as a rule, not be so severe.
It is also noted from the above examples that the degree of fixation substantially corresponds to the amount of preservative introduced per unit weight of wood. A small content of preservative is fixed to a higher degree than a preservative having a higher con-centration. Such a property is the opposite to the effect of the fixation of negative radicals as arsenic, fluorine and boron compounds. Surprisingly, the fixed amounts exceed the amounts needed to provide adequate preservative protection. In the examples a sPecific amount of preservative is introduced and distributed in a specific amount of saw dust. If the amount of pre-servative is high, a part of it remains leachable or soluble. In practice the soluble or leachable portion of the metal can diffuse to the inner region of the wood which contains less preservative. The distribu-tion obtained by a pressure treatment normally result-ing in a decreasing amount towards the inner region of the wood can thus be improved due to the properties of the preservative.
The corrosion question is of little conse-quence when zinc salts such as zinc acetate are used.
The situation differs if copper salts such as copper acetate are used. The presence of boric acid will, as a rule, control the corrosion problem. Diluted solu-tions of copper acetate are corrosive to some extent ~1~75()5 while more concentrated solutions are not so corro-sive. The corrosion can, however, be kept under con-trol quite easily. The addition of about 0.01 percent of sodium nitrite or about 0.03 percent ammonium ace-tate to a 1 percent solution of copper acetate thus overcomes the corrosion problem.
Such protection can also be obtained with other additives. It is interesting to note that the addition of a small surplus of acetic acid to the aque-ous copper acetate solution does not increase the cor-rosion. A surplus of about 0.05 percent acetic acid has even demonstrated a certain corrosion protective effect. If the excess amount of acetic acid is increased to about 0.10 percent, the corrosion will again increase. A surplus of acetic acid can be avoided by the addition of, for example, about 0.01 percent sodium nitrite to the solution.
In the full cell treatment of Swedish pine when, as a rule, 300 litres of preservative solution may be introduced per cubic meter of wood, the follow-ing concentrations of the preservative solut;on have been found to be suitable. If a copper salt is used alone the concentration thereof preferably is about 0.
percent and may range from about 0.3 to about 0.6 per-cent based on the copper. The concentration of zinc salt alone will be about 0.6 to 1.0 percent zinc based on the zinc. Generally the same concentrations can be used for mixtures of copper and zinc salts. A treat-ment solution comprising such a mixture can, for ,'~
1~75~5 example, contain about 0.12 to about 0.24 percent by weight copper and 0.36-0.60 percent by weight zinc based on the weight of the copper and zinc. These mixtures advantageously contain higher percentages of zinc than copper as previously stated.
~ ethods other than the full cell treatment can, of course, be used in the preservation of wood.
The strength of the solution must then be adapted in view of the amount of solution introduced into the wood by the different treatments so that the wood receives an adequate amount of preservative. The following guidelines can be generally followed. When treating wood according to the Lowry method, the woofl will receive about half the amount of solution as by fu11 cell treatment, e.g., about 1~0 instead of 300 litres per cubic meter of wood. In order to introduce the same amount of preservative into the wood, a double strength solution is used in the Lowry treatment as opposed to that employed in the full cell treatment.
In the diffusion treatment of wood employing strong solutions, the preservative of the present invention provides special advantages. The preserva-tive will diffuse into the wet (green~ wood whereupon a certain amount of the preservative is fixed and the rest further diffuses into the wood where it will be fixed upon drying.
The preservative has heen described ahove in form of water solutions. It is also use~ in this way.
_9_ The preservative is manufactured and distri-buted as a solid salt, which before use is dissolved to desired strength.
Examples of the preservative in form of solid salts are given in Table I. The figures are in percent by weight.
1147S~1S
~BIE I
ExemPlary I~redients of Preservative (% by wt of preservatives) Preser- ~
vative Cu/Acetate Zn Acetate Boric Acid NaNitrite ZnSulfate In order to be clear it may be said that copper acetate contains 35 percent copper and zinc acetate contains 35.6 percent zinc. This mean~ that a solution containing 0.3 percent copper is made up of 0.86 percent copper acetate. The specification dis-cusses percent copper or zinc as the metals are the protective agents. Boric acid is signified by H3BO3.
, ' ,
Claims (11)
1. A preservative for wood or similar organic materials consisting essentially of an aqueous solution of boric acid and a preservative material selected from the group consisting of a copper or zinc acetate or mixtures thereof.
2. THe preservative of claim 1 wherein the preservative material is copper acetate.
3. The preservative of claim 1 wherein the preservative material is zinc acetate.
4. The preservative of claim 1 wherein the boric acid is present in an amount ranging from about 0.2 to 0.6 percent by weight based on the weight of the solution.
5. The preservative of claim 1 wherein the solution fur-ther includes a minor amount of a metal salt of a strong acid.
6. The preservative of claim 5 wherein said strong acid is sulphuric acid.
7. The preservative of claim 1 wherein said solution fur-ther includes an emulgated oil.
8. The preservative of claim 7 wherein said oil is pre-sent in an amount of about 5 to about 20 percent by weight of said solution.
9. The preservative of claim 1 wherein said solution further includes a soluble nitrite.
10. The preservative of claim 9 wherein said nitrite is present in an amount less than about 0.1 percent by weight based on said solution.
11. The preservative of claim 1 wherein said solution fur-ther contains a minor amount of an iodide.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB8027265A GB2082912A (en) | 1980-08-21 | 1980-08-21 | Wood preservative |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1147505A true CA1147505A (en) | 1983-06-07 |
Family
ID=10515595
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000360158A Expired CA1147505A (en) | 1980-08-21 | 1980-09-12 | Wood preservative and method of use thereof |
Country Status (5)
| Country | Link |
|---|---|
| AU (1) | AU560490B2 (en) |
| CA (1) | CA1147505A (en) |
| DE (1) | DE3032463A1 (en) |
| GB (1) | GB2082912A (en) |
| SE (1) | SE430865B (en) |
Families Citing this family (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| SE8600888L (en) * | 1986-02-27 | 1987-08-28 | Bror Olof Heger Hager Ab | ORGANIC MATERIALS CONSERVATOR |
| DE3764284D1 (en) * | 1986-03-19 | 1990-09-20 | Katayama Chemical Works Co | TREATMENT METHOD FOR WOOD PRESERVATION AND WOOD PRESERVATION AGENT FOR THE PROCESS. |
| DE3609544A1 (en) * | 1986-03-21 | 1987-09-24 | Wolman Gmbh Dr | WOOD PRESERVATIVES |
| DE3680112D1 (en) * | 1986-09-15 | 1991-08-08 | Desowag Materialschutz Gmbh | WOOD PRESERVATIVES. |
| NZ236976A (en) * | 1990-02-02 | 1991-11-26 | Hickson Int Plc | Aqueous preservative compositions containing a biocidal cation and nitrite ions with ph above 6.5 |
| US5207823A (en) * | 1990-04-03 | 1993-05-04 | Kabushiki Kaisha Koshii Preserving | Wood preservative composition and process for treating wood with the same |
| US6896908B2 (en) * | 2001-01-30 | 2005-05-24 | U.S. Borax Inc. | Wood preservative concentrate |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB596713A (en) * | 1945-07-31 | 1948-01-09 | Gascoignes Reading Ltd | Improvements in and relating to automatic milking systems |
| DE241707C (en) * | ||||
| FR973162A (en) * | 1941-07-02 | 1951-02-08 | Serpi Lab | Product for the protection of wood and its manufacturing process |
-
1979
- 1979-03-14 SE SE7902273A patent/SE430865B/en not_active IP Right Cessation
-
1980
- 1980-08-21 GB GB8027265A patent/GB2082912A/en not_active Withdrawn
- 1980-08-27 AU AU61808/80A patent/AU560490B2/en not_active Ceased
- 1980-08-28 DE DE19803032463 patent/DE3032463A1/en not_active Ceased
- 1980-09-12 CA CA000360158A patent/CA1147505A/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| SE430865B (en) | 1983-12-19 |
| DE3032463A1 (en) | 1982-04-01 |
| AU6180880A (en) | 1982-03-04 |
| AU560490B2 (en) | 1987-04-09 |
| SE7902273L (en) | 1980-09-15 |
| GB2082912A (en) | 1982-03-17 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |