# US 2009/0280185 A1 · Particulate wood preservative and method for producing the same

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- Number: US 2009/0280185 A1
- Document ID: US20090280185A1
- Status: Published application
- Kind: A1
- Application number: 12/458,522
- Filed: 2009-07-15
- Published: 2009-11-12
- Earliest claimed: 2003-06-17
- Assignees: PhibroWood, LLC
- Inventors: H. Wayne Richardson; Robert L. Hodge
- Web page: https://patentgrep.com/patent/US20090280185A1

## CPC

- A01N 59/20: Copper
- A01N 25/12: Powders or granules (A01N25/26 takes precedence)
- A01N 25/26: in coated particulate form
- C09D 15/00: Woodstains
- B27K 3/005: {employing compositions comprising microparticles}
- B27K 3/007: {employing compositions comprising nanoparticles}
- B27K 3/22: Compounds of zinc or copper
- B27K 3/32: Mixtures of different inorganic impregnating agents
- B27K 3/52: Impregnating agents containing mixtures of inorganic and organic compounds
- A01N: PRESERVATION OF BODIES OF HUMANS OR ANIMALS OR PLANTS OR PARTS THEREOF (preservation of food or foodstuff A23); BIOCIDES, e.g. AS DISINFECTANTS, AS PESTICIDES OR AS HERBICIDES (preparations for medical, dental or toiletry purposes which kill or prevent the growth or proliferation of unwanted organisms A61K); PEST REPELLANTS OR ATTRACTANTS; PLANT GROWTH REGULATORS
- C09D: COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR (cosmetics A61K; processes for applying liquids or other fluent materials to surfaces, in general, B05D; staining wood B27K5/02; glazes or vitreous enamels C03C; natural resins, French polish, drying-oils, driers, turpentine, per se, C09F; polishing compositions other than French polish, ski waxes C09G; adhesives or use of materials as adhesives C09J; materials for sealing or packing joints or covers C09K3/10; materials for stopping leaks C09K3/12; processes for the electrolytic or electrophoretic production of coatings C25D)
- 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 (applying liquids or other fluent materials to surfaces in general B05; coating wood or similar material B44D); CHEMICAL OR PHYSICAL TREATMENT OF CORK, CANE, REED, STRAW OR SIMILAR MATERIALS

## Abstract

A wood preservative includes injectable particles comprising one or more sparingly soluble copper salts. The copper-based particles are sufficiently insoluble so as to not be easily removed by leaching but are sufficiently soluble to exhibit toxicity to primary organisms primarily responsible for the decay of the wood. Exemplary particles contain for example copper hydroxide, basic copper carbonate, copper carbonate, basic copper sulfates including particularly tribasic copper sulfate, basic copper nitrates, copper oxychlorides, copper borates, basic copper borates, and mixtures thereof. The particles typically have a size distribution in which at least 50% of particles have a diameter smaller than 0.25 μm, 0.2 μm, or 0.15 μm. At least about 20% and even more than 75% of the weight of the particles may be composed of the substantially crystalline copper salt. Wood or a wood product may be impregnated with copper based particles of the invention.

## Claims

### Claim 1

A method of preserving wood comprising: injecting a wood preservative composition suspended in a liquid carrier into a wood having open porosity therein, wherein the composition comprises a plurality of injectable particles comprising a substantially crystalline, sparingly soluble copper salt; and a corrosion inhibitor.

### Claim 2

A method of preserving wood comprising:
injecting a wood preservative composition suspended in a liquid carrier into a wood having open porosity therein,
wherein the composition comprises a plurality of injectable particles comprising a milled, sparingly soluble copper salt.

### Claim 3

A method of preserving wood comprising:
injecting a wood preservative composition suspended in a liquid carrier into a wood having open porosity therein,
wherein the composition comprises a plurality of particles comprising a solid, sparingly soluble copper salt,
wherein the particles comprise less than 25% by weight of a polymer, and
wherein at least 95% by weight of the particles have an average diameter of less than 1 micron.

### Claim 4

A method of preserving wood comprising:
injecting a wood preservative composition suspended in a liquid carrier into a wood having open porosity therein, wherein the composition comprises a plurality of particles comprising a substantially crystalline, sparingly-soluble copper salt,
wherein more than about 90% by weight of the particles is the copper salt; and
wherein the particles have an average diameter of less than 1 micron.

### Claim 5

A method of preserving wood comprising:
injecting a wood preservative composition suspended in a liquid carrier into a wood having open porosity therein, wherein the composition comprises a plurality of injectable particles comprising at least about 50% by weight of a substantially crystalline, sparingly soluble copper salt,
wherein substantially no injected particles have an average diameter greater than 1.5 microns, and
wherein at least 50% by weight of the particles have a diameter greater than 40 nanometers.

### Claim 6 (depends on 1, 2, 3, 4)

The method of claims 1, 2, 3, 4, or 5, wherein the composition further comprises a corrosion inhibitor.

### Claim 7 (depends on 1, 2, 3, 4)

The method of claims 1, 2, 3, 4, or 5, wherein the sparingly soluble copper salt further comprises zinc, with the proviso that the sparingly soluble copper salt is not copper hydroxide.

### Claim 8 (depends on 1, 2, 3, 4)

The method of claims 1, 2, 3, 4, or 5, wherein the wood preservative further comprises a plurality of other injectable particles, wherein the other injectable particles comprise at least 20% by weight of a sparingly soluble zinc salt.

### Claim 9 (depends on 1, 2, 3, 4)

The method of claims 1, 2, 3, 4, or 5, wherein at least 50% by weight of the particles have a diameter greater than 40 nanometers.

### Claim 10 (depends on 1, 2)

The method of claim 1 or claim 2, wherein at least 95% by weight of the particles have an average diameter of less than 1 micron.

### Claim 11 (depends on 1, 2, 3, 4)

The method of claims 1, 2, 3, 4, or 5, wherein the wood preservative composition further comprises at least one organic biocide.

### Claim 12 (depends on 11)

The method of claim 11 wherein the at least one organic biocide is a biocidal azole.

### Claim 13 (depends on 11)

The method of claim 11, wherein at least a portion of the organic biocide is coated on the injected particles such that the leach rate of the sparingly soluble copper salt as measured by the AWPA Standard Method E11-97 is less than the leach rate of similarly injected particles of sparingly soluble copper salt not having organic biocide coated thereon.

### Claim 14 (depends on 1, 2, 3, 4)

The method of claims 1, 2, 3, 4, or 5, wherein the liquid carrier comprises water and an amine, wherein the total amount of amine is less than 1 molecule per four atoms of total copper present in the composition.

### Claim 15 (depends on 1, 2, 3, 4)

The method of claims 1, 2, 3, 4, or 5, wherein the liquid carrier comprises water and at least one of an alkanolamine or ammonia, wherein the alkanolamine and ammonia are each present in an amount less than 1% by weight of the wood preservative composition and liquid carrier.

### Claim 16 (depends on 1, 2, 3, 4)

The method of claims 1, 2, 3, 4, or 5, wherein the sparingly soluble copper salt comprises basic copper carbonate.

### Claim 17 (depends on 1, 2, 3, 4)

The method of claims 1, 2, 3, 4, or 5, wherein the wood preservative composition further comprises a nitrite.

### Claim 18 (depends on 1, 3, 4)

The method of claims 1, 3 or 4, wherein the particles comprise at least about 75% by weight of a crystalline sparingly soluble copper salt.

### Claim 19 (depends on 1, 2, 3, 4)

The method of claims 1, 2, 3, 4, or 5, wherein the sparingly soluble copper salt is a sparingly soluble copper/zinc salt having a substantial amount of zinc, wherein zinc cations from the zinc salt are dispersed within the copper salt.

### Claim 20 (depends on 3)

The method of claim 3, wherein greater than 98% by weight of the particles have a particle size with diameter equal to or less than 0.5 microns as determined by the settling velocity of the particle in water.