Patent ID: 6887527

Claim:
A method for preparing modified wood comprising treating wood with an aqueous water repellent [I] and treating the same with an emulsion water repellent [II], said aqueous water repellent [I] comprising a product obtained through co-hydrolytic condensation of (A) 100 parts by weight of an organosilicon compound of the general formula (1): (R 1 ) a (OR 2 ) b SiO (4âˆ’aâˆ’b)/2 (1) wherein R 1 is a C 1-6 alkyl group, R 2 is a C 1-4 alkyl group, a is a positive number of 0.75 to 1.5, b is a positive number of 0.2 to 3, satisfying 0.9<a+bâ‰¦4, and (B) 0.5 to 49 parts by weight of an amino-containing alkoxysilane of the general formula (2): R 3 R 4 NR 5 â€”SiR 6 n (OR 2 ) 3-n (2) wherein R 2 is as defined above, R 3 and R 4 are each independently hydrogen or a C 1-15 alkyl or aminoalkyl group, R 5 is a divalent C 1-18 hydrocarbon group, R 6 is a C 1-4 alkyl group, and n is 0 or 1, or a partial hydrolyzate thereof, in the presence of an organic or inorganic acid, said emulsion water repellent [II] being a trialkylsiloxysilicate emulsion water repellent obtained by polymerizing (C) an organodisiloxane of the general formula (3): R 7 3 Siâ€”Oâ€”SiR 7 3 (3) wherein R 7 is each independently a C 1-10 alkyl group, and (D) at least one of a tetraalkoxysilane of the general formula (4): Si(OR 7 ) 4 (4) wherein R 7 is each independently a C 1-10 alkyl group, and a partial hydrolytic condensate thereof, in such a proportion that the molar ratio of trialkylsiloxy units: R 7 3 SiO 0.5 in component (C) to tetrafunctional units: SiO 4/2 in component (D) may fall in a range of 0.5 to 2.0, in an aqueous solution containing (E) a surfactant and (F) water at a temperature of 30 to 90Â° C.