Production method of polyarylene sulfide, cyclic polyarylene sulfide pellet and production method thereof

摘要

A production method includes a process (I) of heating a cyclic polyarylene sulfide composition under reduced pressure and a process (II) of heating and polymerizing a cyclic polyarylene sulfide composition. This simple method allows for production of a polyarylene sulfide of the higher molecular weight and can produce a polyarylene sulfide having a narrow molecular weight distribution, low gas generation and high industrial usability. Additionally, pelletization after the process (I) can produce a cyclic polyarylene sulfide pellet having ease of conveyance, excellent molding processability, less gas generation amount and high industrial usability.

主权项

1. A method of producing polyarylene sulfide from a cyclic polyarylene sulfide composition (a) which comprises not less than 50% by weight of a cyclic polyarylene sulfide expressed by Formula (1):(where Ar represents an arylene group and m is an integral number of 4 to 50, wherein the cyclic polyarylene sulfide may be a mixture of plural different cyclic polyarylene sulfides having different numbers m),
the method comprising: a process (I) of heating, under reduced pressure, the cyclic polyarylene sulfide composition (a) having not less than 1.0% of a weight reduction ratio ΔWr(a) under heating according to Equation (2) to obtain a cyclic polyarylene sulfide composition (b) which has less than 50% of a reduction ratio of the cyclic polyarylene sulfide to the cyclic polyarylene sulfide composition (a) and has less than 1.0% of a weight reduction ratio ΔWr(b) under heating according to Equation (2),
ΔWr(x)=(W1−W2)/W1×100%  (2)(where ΔWr(x) denotes a weight reduction ratio (%) of a material (x) and is obtained from a sample weight (W2) at temperature reaching 330° C. relative to a sample weight (W1) at temperature reaching 200° C. in thermogravimetric analysis in a non-oxidizing atmosphere under ordinary pressure with increasing temperature from 50° C. to any temperature of not lower than 330° C. at a temperature rise rate of 20° C./minute); and
a process (II) of heating the cyclic polyarylene sulfide composition (b) to obtain a polyarylene sulfide (c) which has not less than 50% of the reduction ratio of the cyclic polyarylene sulfide to the cyclic polyarylene sulfide composition (a) and has a weight-average molecular weight of not less than 10,000.