Ammoniacal Borate And Zinc Compositions, And Methods For Treating Wood Products
AssigneesPQ Corporation, U.S. Borax Inc.
InventorsYatao Hu, Neil T. Miller, David M. Schubert
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Abstract
Compositions and methods are provided for treating wood products to provide leachresistant protection against fungal decay, termites and other wood destroying organisms. The preservative compositions provided include ammonia-stabilized solutions of zinc and boron, preferably in a molar ratio of Zn:B of between about 0.4:1 and 5:1, and are essentially copper free. The preservative may be applied by vacuum and/or pressure treatment or dip treatment under atmospheric pressure.
Claims24
An aqueous preservative composition comprising a source of zinc selected from the group consisting of zinc oxide and soluble zinc salts;
- a source of borate selected from the group consisting of zinc borate, boric acid, boric oxide and water soluble borate salts;
- a source of ammonia;
- and water;
- wherein the composition is essentially copper-free and comprises at least 50 wt % water.
An aqueous preservative composition consisting essentially of a source of zinc selected from the group consisting of zinc oxide and soluble zinc salts, a source of borate selected from the group consisting of zinc borate, boric acid, boric oxide and water soluble borate salts, a source of ammonia, and water, wherein the composition is essentially copper-free and comprises at least 50 wt % of water.
A method of making an aqueous preservative composition comprising the steps of:
- (a) dissolving a source of zinc in an aqueous ammonia-containing solution to produce an aqueous zinc solution;
- (b) adding to the zinc solution a source of borate selected from the group consisting of zinc borate, boric acid, boric oxide and water soluble borate salts to the aqueous zinc solution;
- and (c) mixing until essentially all solids are dissolved, the composition being essentially copper-free.
A method for preserving an article comprising wood fibers, the method comprising the steps of:
- (a) applying to the article an aqueous preservative composition prepared by combining ingredients comprising:
- i) a source of zinc selected from the group consisting of zinc oxide and soluble zinc salts;
- ii) a source of borate selected from the group consisting of zinc borate, boric acid, boric oxide and water soluble borate salts;
- iii) a source of ammonia;
- and
- iv) water;
- such that the aqueous composition penetrates into the wood fibers, wherein the composition is essentially copper-free and comprises at least 50 wt % of water;
- and
- (b) drying the wood fibers such that there is deposited therein a bioeffective amount of a residual component comprising zinc and boron.
A method of treating a substrate comprising wood fibers to provide resistance to flame spread, the method comprising the steps of:
- (a) applying to the article an aqueous preservative composition prepared by combining ingredients comprising:
- i) a source of zinc selected from the group consisting of zinc oxide and soluble zinc salts;
- ii) a source of borate selected from the group consisting of zinc borate, boric acid, boric oxide and water soluble borate salts;
- iii) a source of ammonia;
- and
- iv) water;
- such that the aqueous composition penetrates into the wood fibers, wherein the composition is essentially copper-free;
- and
- (b) drying the wood fibers such that there is deposited therein a flame retardant amount of a residual component comprising zinc and boron.
Dependencies are inferred from the claim text.