WOOD PRESERVATIVES

Abstract

A method for preserving wood by contacting wood with a composition comprising a polyurethane polymer, non-aqueous solvents, and a wood preservative.

Claims

1. A method for preserving wood; said method comprising contacting wood with a wood treatment composition comprising: (a) a polyurethane polymer comprising a polyol and an isocyanate in a non-aqueous solvent; (b) at least one organic solvent; and (c) at least one wood preservative selected from among halogenated isothiazolinone biocides, halogenated carbamate fungicides and azole fungicides.

2. The method of claim 1 in which the wood preservative is 4,5-dichloro-2-n-octyl-4-isothiazolin-3-one.

3. The method of claim 1 wherein the organic solvent comprises diesel.

4. The method of claim 1 wherein the polyol composition is selected from the group consisting of 100% poly-1-butylene oxide, 6 to 99.99% poly-i-butylene oxide+0.01 to 94% p-propylene oxide, and 83 to 99.99% poly-i-butylene oxide+0.01-17% p-tetrahydrofuran.

5. The method of claim 1 wherein the polyurethane polymer is capped.

6. The method of claim 1 wherein the polyurethane polymer is capped with a monoamine or monoalcohol.

7. The method of claim 6 wherein the polyurethane polymer is capped with either butyl amine, octanol, or octyl amine.

8. The method of claim 1 wherein the isocyanate is isophorone diisocyanate.

9. The method of claim 1 wherein the isocyanate is polymeric methylene diphenyl diisocyanate.

10. A composition for preserving wood comprising: a) a polyurethane polymer comprising a polyol and an isocyanate in a non-aqueous solvent; (b) an organic solvent; and (c) at least one wood preservative selected from among halogenated isothiazolone biocides, halogenated carbamate fungicides and azole fungicides.

Description

EXAMPLES

Synthesis of Polyurethane Polymers:

[0015] Polyurethanes were synthesized from a bis hydroxy terminated polyalkoxide and a diisocyanate. 150 mL of anhydrous polyalkoxide solution in aromatic 200 (solvent, 10-30 wt % solution), diisocyanate (0.5 to 2 molar equivalents to of isocyanate to hydroxy group), was charged with 0.003% of a Tin catalyst (dibutyltin dilaurate) to the reactor. The reactor was heated to 90° C. with overhead stirring. The reaction mixture was held at 90° C. for 1 h.

[0016] In the examples where the polyurethane is capped, the residual isocyanate is measured using Surface SWYPEs™ test strips. The reaction product was cooled to room temperature and the capping reagent, mono amine (1 equivalent amine to unreacted isocyanate) was added to cap the remaining isocyanate groups in the reaction mixture. Alternatively, when mono alcohol (1 equivalent hydroxyl to unreacted isocyanate) was used as the capping reagent it was added at 90° C. and reacted for an additional 1 h at 90° C. The polymer solids of the PU solution was estimated from the conversion and the amount of reactants used for the reaction. The polymer solids are calculated as the sum of the reactive components in the synthesis of the polymer.

Procedure to Determine Diesel Compatibility:

[0017] In a clear, 1 oz vial, 0.1 gram of the polymer (on a 100% polymer solids basis) is diluted with 9.9 grams of diesel fuel (weight/weight) to a 1% solution of the polymer. The sample is maintained at room temperature for 24 hours. After 24 hours, the solution is checked for incompatibility, defined as phase separation, precipitation of the polymer as solids, and/or turbidity.

Wood Treatment Solution Preparation:

[0018] In a 4 liter vessel, 3 kilograms of wood treatment solution is prepared by adding diesel fuel, polymer solution, and DCOIT technical to obtain a final concentration of 2.5% DCOIT and 2.5% polymer solids. [0019] For polymers at 30% solids, this equates to 2675 grams of diesel, 75 grams of DCOIT, and 250 grams of polymer solution. [0020] For polymers at 10% solids, this equates to 2175 grams of diesel, 75 grams of DCOIT, and 750 grams of polymer solution.

Procedure to Treat Wood:

[0021] Three (27×9.0×1.9 cm) pieces of Southern Yellow Pine are loaded into a 6 L pressure vessel. The vessel is sealed and the pressure is reduced to 5 inches of Hg (17 kPa) and held for 5 minutes. The vacuum is turned off and sufficient treatment solution is drawn from a treatment solution container into the vessel through a fill valve to completely cover the wood. The vessel is pressurized to 100 psig (689 kPa) held for a minute, then to 150 psig (1136 kPa) for 1 minute. The pressure is released and the vessel is maintained at ambient pressure for 1 minute. The vessel is drained to the original treatment solution container via a dropout valve. The pressure cylinder is then placed under vacuum at >24 inches of Hg (>81 kPa) for forty five (45) minutes. The vessel is again drained to the original treatment solution container via a dropout valve. The pressure cylinder is then placed under vacuum at >24 inches of Hg (>81 kPa) for thirty (30) minutes. The vessel is again drained to the original treatment solution container via a dropout valve. The wood is removed, sticker stacked, and allowed to remain at room temperature until analysis.

Analysis of Treated Wood:

Dislodgeable Residue (DLR) Assay:

[0022] The dislodgeable residue assay was conducted by placing a piece of 4 inch square polyester fabric moistened with 2 ml of water on the wood. A piece of aluminum foil was placed over the cotton fabric and a 12.5 kg rolling pin was rolled back and forth over the foil covered wood twenty (20) times (10 up and back motions) being careful not to exert any downward nor upward pressure on the rolling pin during the rolling process. The fabric was removed and extracted with 15 milliliters of methanol in a sonication bath for 1 hour and then diluted with 5 milliliters of water. The methanol/water solution was analyzed by HPLC for DCOIT.

TABLE-US-00001 TABLE 1 Diesel Compatibility of Different Types of Polymer Diesel Compatibility Polymer # Trade Name Generic Composition Available From (1 wt %) 1 Rosin Rosin ChemicalStore.com No 2 Terol 1304 Aromatic polyester polyol Huntsman No 3 Isoexter 3061 Aromatic polyester polyol Huntsman No 4 Lignin Lignin Aldrich No 5 Polystyrene Polystyrene Aldrich No 6 Poly vinyl chloride Poly vinyl chloride Aldrich No 7 Laroflex MP45 Copolymer of vinyl chloride BASF No and vinyl isobutyl ether 8 Isoexter 4404 Aromatic polyester polyol Huntsman No 9 Ethocel 10FP Ethylcellulose polymer DOW No 10 Ethocel 45 Ethylcellulose polymer DOW No 11 Ethocel 100FP Ethylcellulose polymer DOW No 12 Isopar V Isoparaffinic fluid Exxon No 13 Pentalyn 755-M Phenolic modified rosin ester Eastman No 14 Polyvinylimidazole Polyvinylimidazole DOW No 15 Polyvinylpyridine Polyvinylpyridine Aldrich No 16 Polyvinylpyrrolidone Polyvinylpyrrolidone Aldrich/Acros No 17 Papi 27 Polymeric MDI (pMDI) DOW No (Polymeric Methylene Diphenyl Diisocyanate) 18 Paraloid A-10S Thermoplastic acrylic resin Rohm and Haas No 19 Paraloid UCD-685 Acrylic polyol resin Rohm and Haas No 20 Paraloid F-10 Resin Thermoplastic acrylic resin DOW No 21 Paraloid AT-9LO Thermoplastic acrylic resin Rohm and Haas No 22 Paraloid B-67MT Thermoplastic solution resin Rohm and Haas No 23 Paraloid AT-147 Thermoset acrylic resin Rohm and Haas No 24 Paraloid AT-410 Thermoset Acrylic Resin DOW No 25 Paraloid AT-148 Thermoset Acrylic Resin Rohm and Haas No 26 Paraloid UCD-750 Acrylic polyol resin Rohm and Haas No 27 Paraloid NAD-10-V Acrylic Non-Aqueous Rohm and Haas No Dispersion Resin 28 Paraloid AT-76 thermosetting acrylic Rohm and Haas No intermediate 29 Paraloid AT-63 thermosetting acrylic Rohm and Haas No intermediate 30 Slack Wax Paraffinic wax Lone Star No

TABLE-US-00002 TABLE 2 Diesel Compatibility of PU Polymers with 100% p-iBO Solids (NCO/OH Diesel Polymer Polyol Isocyanate Content molar compatibility # (bis OH) (Bis NCO) Cap (wt %) ratio) (1 wt. %) Ex-1 OSP 680 (p-iBO) IPDI Butyl 30 2 Yes Amine Ex-2 OSP 680 (p-iBO) IPDI Octyl 30 2 Yes Amine Ex-3 OSP 680 (p-iBO) IPDI Octanol 30 2 Yes Ex-4 OSP 680 (p-iBO) IPDI No 30 2 Yes Ex-5 OSP 680 (p-iBO) pMDI Butyl 10 1.09 Yes Amine Ex-6 OSP 680 (p-iBO) pMDI Butyl 30 0.5 Yes Amine Ex-7 OSP 680 (p-iBO) HMDI Butyl 30 2 Yes Amine Ex-8 OSP 680 (p-iBO).sup.1 pMDI Butyl 30 0.5 Yes Amine Ex-9 OSP 680 (p-iBO).sup.1 MDI Butyl 30 1.09 Yes Amine Comp. 1 OSP 680 (p-iBO) pMDI Butyl 10 2 No Amine Comp. 2 OSP 680 (p-iBO) IPDI Butyl 10 4 No Amine Comp. 3 OSP 680 (i-nBO) IPDI EO/PO 10 0.5 No Jeffamine Ex-10 OSP 320 (p-iBO) IPDI Butyl 30 2 Yes Amine Ex-11 OSP 320 (p-iBO) pMDI Butyl 30 1.09 Yes Amine Ex-12 OSP 320 (p-iBO).sup.1 pMDI Butyl 30 0.5 Yes Amine Ex-13 OSP 320 (p-iBO).sup.1 pMDI Butyl 30 1.09 Yes Amine Ex-14 OSP 320 (p-iBO).sup.1 IPDI Butyl 30 1.09 Yes Amine

TABLE-US-00003 TABLE 3 Diesel Compatibility of PU Polymers with ≥6% p-iBO + ≤94% iPO Solids (NCO/O Diesel Polymer Polyol Isocyanate Content H molar compatibility # (bis OH) (Bis NCO) Cap (wt. %) ratio) (1 wt. %) Ex-15 95 wt % IPDI Butyl 10 1.09 Yes OSP Amine 680 (p-iBO) + 5 wt % P4000 (iPO) Ex-16 94 wt % IPDI Butyl 10 2 Yes OSP Amine 680 (p-iBO) + 6 wt % P4000 (iPO) Ex-17 50 wt % IPDI Butyl 10 1.09 Yes OSP Amine 680 (p-iBO) + 50 wt % P4000 (iPO) Ex-18 6 wt % IPDI Butyl 10 2 Yes OSP amine 680 (p-iBO) + 94 wt % P4000 (p-iPO) Comp. 4 5 wt % IPDI Butyl 10 4 No OSP Amine 680 (p-iBO) + 95 wt % P4000 (iPO) Comp 5 P4000 IPDI Butyl 10 2 No (p-iPO) Amine

TABLE-US-00004 TABLE 4 Diesel Compatibility of PU Polymers with ≥83% p-iBO + ≤17% p-nBO Solids (NCO/OH Diesel Polymer Polyol Isocyanate Content molar compatibility # (bis OH) (Bis NCO) Cap (Wt. %) ratio) (1 wt. %) Ex-19 95 wt % OSP 680 (p-iBO) IPDI Butyl 10 2 Yes + 5 wt % p-THF (p-nBO) amine Ex-20 90 wt % OSP 680 (p-iBO) IPDI Butyl 10 2 Yes + l0 wt % p-THF (p-nBO) amine Ex-21 85 wt % OSP 680 (p-iBO) IPDI Butyl 10 2 Yes + 15 wt % p-THF (p-nBO) amine Ex-22 83 wt % OSP 680 (p-iBO) IPDI Butyl 10 2 Yes + 17 wt % p-THF (p-nBO) amine Comp. 6 50 wt % OSP 680 (p-iBO) IPDI Butyl 10 2 No + 50 wt % p-THF (p-nBO) amine Comp. 7 75 wt % OSP 680 (p-iBO) IPDI Butyl 10 2 No + 25wt % p-THF (p-nBO) amine Comp. 8 80 wt % OSP 680 (p-iBO) IPDI Butyl 10 2 No + 20 wt % p-THF (p-nBO) amine Comp. 9 82 wt % OSP 680 (p-iBO) IPDI Butyl 10 2 No + 18 wt % p-THF (p-nBO) amine Comp. 10 poly-THF (p-nBO) IPDI Butyl 10 2 No Amine

TABLE-US-00005 TABLE 7 DLR Test results for IPDI Isocyanate 24 hr 24 hr 24 hr Average DLR DLR DLR 24 hr Polymer % % (ug/cm2) (ug/cm2) (ug/cm2) DLR Treatment ID DCOIT Polymer Board A Board B Board C (ug/cm2) #1 None 2.5 0   0.72 1.32 0.51 0.85 #2 EX-2  2.5 2.5 0.46 0.58 0.55 0.53 #3 EX-10 2.5 2.5 0.57 0.50 0.37 0.48 #4 EX-14 2.5 2.5 0.55 0.50 0.43 0.49 7 day 7 day 7 day Average DLR DLR DLR 7 day Polymer % % (ug/cm2) (ug/cm2) (ug/cm2) DLR Treatment ID DCOIT Polymer Board A Board B Board C (ug/cm2) #1 None 2.5 0   0.36 1.00 0.75 0.70 #2 EX-2  2.5 2.5 0.32 0.52 0.61 0.48 #3 EX-10 2.5 2.5 0.28 0.44 0.55 0.42 #4 EX-14 2.5 2.5 0.37 0.47 0.63 0.49

TABLE-US-00006 TABLE 8 DLR Test results for IPDI/MDI Isocyanate 24 hr 24 hr 24 hr 24 hr Average DLR DLR DLR DLR 24 hr Polymer % % (ug/cm2) (ug/cm2) (ug/cm2) (ug/cm2) DLR Treatment ID DCOIT Polymer Board A Board B Board E Board F (ug/cm2) #5 None 2.5 2.5 0.72 1.32 0.89 0.59 1.17 #6 EX-12 2.5 2.5 1.96 1.01 0.47 0.41 1.28 #7 EX-11 2.5 2.5 Not Not 0.33 0.32 0.33 Measured Measured #8 EX-5  2.5 2.5 Not Not 0.47 0.33 0.40 Measured Measured #9 EX-6  2.5 2.5 1.80 0.94 0.88 0.53 1.38 #10  EX-13 2.5 2.5 1.92 0.69 1.64 0.68 1.64 7 day 7 day 7 day 7 day Average DLR DLR DLR DLR 7 day Polymer % % (ug/cm2) (ug/cm2) (ug/cm2) (ug/cm2) DLR Treatment ID DCOIT Polymer Board A Board B Board E Board F (ug/cm2) #5 None 2.5 2.5 0.36 1.00 0.86 0.40 0.87 #6 EX-12 2.5 2.5 0.53 0.42 0.43 0.45 0.61 #7 EX-11 2.5 2.5 Not Not 0.34 0.36 0.35 Measured Measured #8 EX-5  2.5 2.5 Not Not 0.37 0.29 0.33 Measured Measured #9 EX-6  2.5 2.5 0.62 0.45 0.53 0.35 0.65 #10  EX-13 2.5 2.5 0.58 0.40 0.80 0.42 0.73