|Budget Amount *help
¥6,400,000 (Direct Cost : ¥6,400,000)
Fiscal Year 1999 : ¥1,000,000 (Direct Cost : ¥1,000,000)
Fiscal Year 1998 : ¥3,500,000 (Direct Cost : ¥3,500,000)
Fiscal Year 1997 : ¥1,900,000 (Direct Cost : ¥1,900,000)
Retention ability of agent : WPG, which treated with low molecular - weight silicic acid - inorganic compound agent, was 17 - 22% in case of silicic acid - metal chloride compound agent and was about 15% in case of boric acid compound agent. The treated woods were offered in decay test using Fomitopsis palustris and Trametes versicolor. Ash of specimen after decay test was 16 - 17% in case of metal chloride compound agent and was 13.5 -14% in case of boric acid compound agent against about 0.3% (w/w) of untreated wood. In other words, it became clear that the leaching quantity of the metal chloride compound agent was larger than that of boric acid compound agent in moisture atmosphere in decay examination. In case of metal chloride compound agent, the reduction rate of metal was larger than that of silicon. There was not the differential in reduction rate of silicon and boron of boric acid compound agent before and after the decay test. In other words, boric acid, which can enter cryst
al lattice of high molecular weight silicic acid, is the best as a chemical compounding with low molecular weight silicic acid.
Preservation mechanism : F. palustris was standing cultured using the liquid medium, which mixed the wood powder treated with agent difference in combination rate of boric acid. Growth of mycelium with much quantity of boric acid was inhibited, and there was a little quantity of formed protein too. The activities of various enzyme in crude enzyme, which was prepared from the liquid medium were lower than that of control wood powder. The drop of pH of culture medium with much quantity of boric acid was restrained. In other words, growth and generation mechanism of oxalic acid of F. palustris were inhibited by addition of the compound that impregnated into the chain layer. However, the activity of enzymes as the mannase, which was initial enzyme of decay by F. palustris was not inhibited greatly.
Test of termite resistance ability : Termite resistance ability with many quantities of added boric acid is large, and the termite died by contact poison. When treated powder is bait, every termite dies in 1 -4 days, and the mass loss of specimen was restrained in 3 - 6% for 49% of control (this value includes weight too of the agent, which was leached in the test.)
Test of flameproofing : The compound wood, which the kind of low molecular weight silicic acid and the quantity of the boric acid were changed and prepared, was offered in the flammability test using a cone-calorimeter. When there is much rate of added acid, the time of firing and the appearance time to flash point are late, the quantity of emitting smoke and the rate of emitting fever rate decrease, and the degree of flameproofing improved. Less