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| PDF : |  13010001.pdf |
| title(En) : | Studies on the Powdered-Dry Bonding Process in the Manufacture of Plywood. V. On the Effects of Hardner and Wood on the Exothermic Behaviour of Urea-Resin Adhesive |
| author(En) : | Atsuo Tanaka, Kiyomine Takashima |
| information : | Mokuzai Gakkaishi 13(1), 1-6 (1967) |
| assort : | Original Article |
| summary(En) : | The first results of the investigation presented in this paper are the effects of amount of ammonium chloride hardner and ammonium chloride with ammonia, and sorts of hardner on the exothermic behaviour of urea-resin adhesive in the curing process after mixing hardner. The sorts of hardner are ammonium sulphate, hydrochloric acid, oxalic acid, monochloracetic acid and aniline hydrochloride. The next result of those is the exothermic behaviour in the cases in which urea-resin adhesive is mixed with lauan wood flour. The results obtained are as follows; 1) In the reactant temperature-time curve, the first exothermic stage, the second exothermic stage and the final exothermic stage are found only in the case of ammonium chloride and ammonium sulphate hardner. It seems that this behaviour is affected by the change of the curing reaction rate with the pH change, owing to the ammonium chloride-formaldehyde or the ammonium sulphate-formaldehyde reaction. The reactant temperature of the first exothermic stage is further affected by the heat of dilution or the heat of reaction of additional agent. 2) In contact with wood, the exothermic behaviour is further affected by the heat of wetting for wood. But it seems that the exothermic behaviour in this case is not essentially different from that of urea-resin adhesive itself. |