Patent ID: 6083617
Filing Date: 2000-07-04
Classification: C08J,C08K,Y10S,Y10T

Abstract:
A polyester composition comprising particles of at least one kind, wherein 0.005 to 10% by weight of said polyester composition comprises substantially amorphous compound oxide particles having a volume average particle diameter of 0.005 to 2 .mu.m and composed mainly of silicon (Si), aluminum (Al) and at least one alkali metal (M), wherein the contents of said silicon, aluminum and alkali metal satisfy the following equations (1) to (3):10 wt. %.ltoreq.Si.ltoreq.45 wt. % (1),3 wt. %.ltoreq.Al.ltoreq.30 wt. % (2),0.5 wt. %.ltoreq.M.ltoreq.20 wt. % (3),and wherein the relative standard deviation "".sigma."" of the particle diameter of said compound oxide particles, as represented by the following equation (4), is not more than 0.3:.sigma.=[.SIGMA..sub.i=1.sup.n (Di-D).sup.2 /n].sup.(1/2) /D (4),D=.SIGMA..sub.i=1.sup.n Di/n (5),where.sigma. represents the relative standard deviation of particle diameter,D represents the number average diameter of particles (.mu.m),Di represents the particle diameter (.mu.m), andn represents the number of particles.