| 摘要 |
PURPOSE:To obtain a laminated sheet of a uniform sheet thickness, by laminating impregnated papers prepared by impregnation with a specified tung oil- modified resol resin and molding the laminate under heat and pressure. CONSTITUTION:A laminate is formed by laminating impregnated papers (grease of 1-4%) obtained by impregnating paper with a tung oil-modified resol resin (content of unreacted phenol of 6-11wt%) obtained by reacting formaldehyde with a phenol-modified tung oil obtained by reacting tung oil with a phenol and having a number-average MW of 1,500-3,000 (the unreacted phenol is not counted) and a MW distribution of 2.5-8.0 (after unreacted phenol is removed). This laminate is molded under application of heat and pressure. In order for the phenol-modified tung oil to be effective as a reactive diluent, it is necessary that 1mol of tung oil is reacted with 2mol or above of a phenol and conditions including a reaction temperature of 50-100 deg.C, a reaction time of 30-240min, an amount of water or an alcohol used of 0.5-5.0wt%, and an amount of a catalyst of 0.1-0.5%.
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