The present invention provides a phenolic resin foamed plate having a thickness of 50 mm or more, in which when the phenolic resin foamed plate is sliced from one main surface of the phenolic resin foamed plate along the main surface in a thickness direction at 5 mm intervals to produce n pieces, which are designated as Q1 to Qn in order from the main surface side, where average densities of Q1 to Qn are dq1 to dqn, respectively, the ratio (dqmin/dqave) of a minimum value dqmin of dq2 to dq(n-1) to an average value dqave of dq2 to dq(n-1) is 0.91 ≤ dqmin/dqave ≤ 0.98, and when a density distribution line is obtained by calculating Di = (dq(i-1) + dqi + dq(i+1))/3 [where i is an integer of 2 to (n-1), and if i is 2 or (n-1), D2 = dq2 or D(n-1) = dq(n-1), respectively], plotting Di in order of numerical values of i (i on the axis of abscissas, Di on the axis of ordinates), and connecting the values of Di, there exists a straight line parallel with the axis of abscissas that intersects the density distribution line at four points.
The present invention provides a phenolic resin foamed plate exhibiting practically sufficient compressive strength and thermal conductivity even when the product thickness is increased.
本发明提供了一种厚度为 50 毫米或以上的
酚醛
树脂发泡板,当从
酚醛
树脂发泡板的一个主表面沿主表面的厚度方向以 5 毫米的间隔切成 n 片时,从主表面一侧依次记为 Q1 至 Qn,其中 Q1 至 Qn 的平均密度分别为 dq1 至 dqave、其中 Q1 至 Qn 的平均密度分别为 dq1 至 dqn,dq2 至 dq(n-1)的最小值 dqmin 与 dq2 至 dq(n-1)的平均值 dqave 之比(dqmin/dqave)为 0。91 ≤ dqmin/dqave ≤ 0.98,通过计算 Di = (dq(i-1) + dqi + dq(i+1))/3 得出密度分布线[其中 i 是 2 到 (n-1) 的整数,如果 i 是 2 或 (n-1),则 D2 = dq2 或 D(n-1) = dq(n-1)]、将 Di 按 i 的数值顺序绘制(i 在缺省轴上,Di 在序数轴上),并将 Di 的数值连接起来,存在一条与缺省轴平行的直线,该直线与密度分布线相交于四点。
本发明提供的
酚醛
树脂发泡板即使在产品厚度增加的情况下也能表现出足够的抗压强度和导热性。