Polyester sheet

A polyester sheet comprising a polyester (A), a 4-methyl-1-pentene polymer (B), and a compatibilizing agent (C), wherein content proportions of the (A), (B), and (C) are 60 to 98.9 parts by mass for (A), 1 to 25 parts by mass for (B), and 0.1 to 15 parts by mass for (C), when a total content of (A), (B), and (C) is set as 100 parts by mass, and wherein the (B) satisfies the following requirements (a) to (d):

• (a) an amount of a constitutional unit derived from 4-methyl-1-pentene is 100 to 90% by mol and a total amount of constitutional units derived from at least one α-olefin selected from ethylene and α-olefins having 3 to 20 carbon atoms (except for 4-methyl-1-pentene) is 0 to 10% by mol;
• (b) a heat of fusion ΔHm (units:
• J/g) and a melting point Tm (units:
• ° C.) measured by differential scanning calorimetry (DSC) satisfy the following requirements (1) and (2):
• ΔHm≥0.5×Tm−76 (1)
• Melting point Tm:
• 200 to 260° C.;
• (2)
• (c) a melt flow rate (MFR) measured under conditions of 260° C. and a 5 kg load in conformity to ASTM D1238 is 0.1 to 500 g/10 min;
• and
• (d) a meso diad fraction (m) measured by 13C-NMR is 98.5 to 100%.