TWI735721B

An object of the present invention is to provide a polyester sheet having better light reflection performance than a conventional polyester sheet while maintaining the excellent properties, such as high mechanical strength, dimensional stability, and durability, inherent in polyester. The present invention relates to a polyester sheet including a polyester (A), a 4-methyl-1-pentene polymer (B) having a specific heat of fusion and a meso diad fraction (m) of 98.5 to 100%, 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 a constitutional unit derived from at least one α-olefin selected from ethylene and α-olefins having 3