| 摘要 |
PROBLEM TO BE SOLVED: To provide a polyurethane foam having high thermal insulation performance.SOLUTION: There is provided a phenol resin having one or more kind bond of the general formulae (1), (2) or (3), where ortho/para bond ratio represented by the formula (4) is 3 or more, 50 mol% or more of a phenol component has a substituent and weight average molecular weight is 200 to 1200. Ortho/para bond ratio=[ortho positions+ortho position and para position×1/2]/[para positions+ortho position and para position×1/2] (4), where ortho positions means percentage of bonds represented by the general formula (1), ortho position and para position means percentage of bonds represented by the general formula (2) and para positions means percentage of bonds represented by the general formula (3) in the formula (4) and X is hydrogen or a substituent in the general formulae (1) to (3).SELECTED DRAWING: None |
