Modified polytetrafluoroethylene fine powder and production of the same.

摘要

Modified PTFE fine powder which comprises primary particles having an average particle size of 0.1 to 0.6 mu m and contains 0.01 to 0.15 % by weight, based on the whole weight of the particles, of at least one olefinically unsaturated compound selected from the group consisting of a fluoroalkyl vinyl ether of the formula: X(CF2)nOCF=CF2 (I) wherein X is a hydrogen atom, a fluorine atom or a chlorine atom and n is an integer of 1 to 6, and a fluoroalkyl vinyl ether of the formula: C3F7(OCF2CF2CF2)m[OCF(CF3)CF2] l OCF=CF2 (II) wherein m is an integer of 0 to 2 and l is an integer of 0 to 2 mainly in core parts of the particles and 0.04 to 0.25 % by weight, based on the whole weight of the particles, of chlorotrifluoroethylene in shell parts, which has good paste extrudability and heat stability.