Heavy duty aqueous wood preservative
AssigneeCanadian Patents and Development Limited
InventorsMichael R. Clarke, Jaromir R. Rak
Life of this patent
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Abstract
An aqueous wood treating and/or preservative composition is provided. The composition has a pH of 9 or more. Of the ions present in the composition, the cations are copper ammonium and/or zinc ammonium ions, while the anions include arsenic or arsenious ions, as well as further anions of an acid ester of phosphoric acid or carbonate or bicarbonate or both such acid ester of phosphoric acid and a, which anions have a solubility of .gtoreq.0.2% in concentrated (28%) aqueous ammonia. The further anions are derived from components which are insoluble in water. Wood treating procedures and treated wood products so-provided are also provided.
Claims10
A wood treating composition comprising an aqueous solution containing:
- a. a normally water-insoluble compound selected from the group consisting of zinc arsenate, zinc arsenite, copper arsenate, and copper arsenite and mixtures thereof in an amount of about 0.1 to about 4% by weight (as Zn or Cu metal) of the total aqueous solution;
- b. about 0.15 to about 10% by weight of the total aqueous solution of a water-repellent component comprising one of
- i. a water-insoluble organic acidic compound having a solubility .gtoreq. about 0.2% and in concentrated aqueous ammonia, said water-insoluble organic acidic compound being selected from the group consisting of acid esters of phosphoric acid with monohydric alcohols and having an acid value between about 200 and about 500, and mixtures thereof, in an amount of about 0 to about 200% of the zinc or copper, or
- ii. a combination of said selected organic acidic compound and a carbonate or bicarbonate ion selected from the group consisting of zinc carbonate, zinc bicarbonate, copper carbonate and copper bicarbonate in an amount of about 0 to about 150% of the zinc or copper;
- and
- c. ammonia, in an amount of about 1 to about 28% by weight of the total aqueous solution;
- the ammonia being sufficient to solubilize said normally water-insoluble salt of zinc or copper and said normally water-insoluble water-repellent compound.
A concentrated aqueous solution comprising a saturated solution, in concentrated aqueous ammonia of about 28% concentration, of
- I.
- a. copper arsenate or
- b. copper arsenite, the copper being present in the amount of about 15 to about 25%;
- c. zinc arsenate or
- d. zinc arsenite, the zinc being present in the amount of about 25 to about 80%;
- e. a mixture of copper arsenate and zinc arsenate or copper arsenite and zinc arsenite, the zinc and copper in the mixture being present in the amount of about 25 to about 5%;
- and
- Ii. an organic acid component having a solubility .gtoreq. about 0.2% and in concentrated aqueous ammonia, said water-insoluble organic acidic compound being selected from the group consisting of acid esters of phosphoric acid with monohydric alcohols and having an acid value between about 200 and about 500, and mixtures thereof.
A concentrated aqueous solution comprising a saturated solution, in concentrated aqueous ammonia of about 28% concentration, of
- I.
- a. copper arsenate or
- b. copper arsenite, the copper being present in the amount of about 15 to about 25%;
- c. zinc arsenate or
- d. zinc arsenite, the zinc being present in the amount of about 25 to about 80%;
- e. a mixture of copper arsenate and zinc arsenate or copper arsenite and zinc arsenite, the zinc and copper in the mixture being present in the amount of about 25 to about 5%;
- Ii. an organic acidic component having a solubility .gtoreq. about 0.2% and in concentrated aqueous ammonia, said water-insoluble organic acidic compound being selected from the group consisting of acid esters of phosphoric acid with monohydric alcohols and having an acid value between about 200 and about 500, and mixtures thereof, and
- Iii. one or more of
- e. copper carbonate
- f. copper bicarbonate
- g. zinc carbonate or
- h. zinc bicarbonate.
Dependencies are inferred from the claim text.