| Budget Amount *help |
¥6,500,000 (Direct Cost: ¥6,500,000)
Fiscal Year 1987: ¥1,200,000 (Direct Cost: ¥1,200,000)
Fiscal Year 1986: ¥1,900,000 (Direct Cost: ¥1,900,000)
Fiscal Year 1985: ¥3,400,000 (Direct Cost: ¥3,400,000)
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| Research Abstract |
Tannin type, non-formaldehyde type, adhesives have been debeloped utilizing the oxidative coupling reaction of phenolic compounds.
(1) Adhesives made from Spent Sulfite Liquor(SSL): The acidification of SSL by addition of acid of cation exchange gave water resistance to resins from SSL. The oxidizing agent works with acid with a multiplied effect, shift thr fromation tempeature of the insoluble products to the lower side of temperature, and also increase the formation ratio of the insoluble products. The curing reaction completed before the remperature reaches 130゜C. for the unterated SSL and the SSL acidified with sulburic acid, the amount of the OH group in the cured resin decreases to samll extent; in thr castion-exchaged SSL, however, the OH group decreases considerably to give greater water-resistance of the cured resin.
(2) Adesives made from Mimosa(Acacia Mollissima,Wattle) Tannin(MT): MT gave a cured resin having some appreciable water-resistrance by the reaction with an oxidizin
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g agent. The reaction between an oxidizing apent and the MT which is acidibied by addition of acid of trintorduction of surfonic acid gabve a resin with higher water-resistance. If the MT is fuether extracted with ethyl acetate,etc.to remove the impurities such as sugers, the water-resistance of the resion was somewhat someshat improced. Furghermore, the chlorinated proc udt of thispurified MT gabe a 100% insoluble resin, K_2Cr_2O_7, differnet from other oxidizing agents, gave a resin hivaing higher water-resistance in a neutral range of pH. If MT reacts with H_2O_2 after oexidation with alkali -O_2 or iodination, it also bage a resin having high water-resistance in the same range of pH as that of K_2Cr_2O_7.
(3) Adhesion test: Uinsg the abhesives which are composed od SSL or MT and adopt H_2O_2, particle boaros were produced. In the sace of acidified SSL; higher water-resistance than that of the ures resin adhesice was attained. In the case of MT, no acidification gacve adhesives having the water-resisting performance similat to that of uea resin, and scifdification gave adhesives having the performance superior to that of the phenol resin adhesive. the pretreatment of wood surface with oxidizing agents improved further the bonding strength of this tannin type adhesives. Less
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