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AssigneeTeijin Limited
InventorsKotaro Takiue, Hiroshi Fujita
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Upon producing a meta-type wholly aromatic polyamide fiber by wet spinning a polymer solution containing a meta-type wholly aromatic polyamide containing a m-phenylenediamine isophthalamide skeleton as a major component, and an amide solvent containing a salt, (1) the polymer solution is ejected into a coagulation bath containing an amide solvent and water and containing a salt at a low concentration to coagulate as a porous thread body (fibrous material), (2) which is subsequently stretched in a plastic stretching bath containing an aqueous solution of an amide solvent, (3) is rinsed with water and then subjected to a heat treatment in a saturated steam atmosphere, and (4) is then subjected to a dry heat treatment, so as to produce a novel meta-type wholly aromatic polyamide fiber that contains an extremely small amount of a solvent remaining in the fibers, contains a small amount of a volatile substance harmful in a heat treatment step at a high temperature, is capable of suppressing coloration of a fiber product, and is capable of providing a product with high performance and high quality.
A meta-type wholly aromatic polyamide fiber excellent in high temperature processability, characterized in that an amount of a solvent remaining in the fiber is 0.8% by weight or less, a dry heat contraction rate at 300° C. is 3% or less, and a breaking strength of the fiber is 3.5 cN/dtex or more, wherein a monofilament of the fiber has a fineness of from 0.5 to 10.0 dtex, and wherein the fiber is produced by a process comprising wet spinning.
A method for producing a meta-type wholly aromatic polyamide fiber excellent in high temperature processability, characterized in that an amount of a solvent remaining in the fiber is 0.8% by weight or less, a dry heat contraction rate at 300° C. is 3% or less, and a breaking strength of the fiber is 3.5 cN/dtex or more,
The method for producing a meta-type wholly aromatic polyamide fiber as claimed in 5, wherein in the step (3), the fibrous material is subjected to the heat treatment at a stretching ratio of from 0.7 to 5.0 times in saturated steam of from 0.02 to 0.50 MPa.
The method for producing a meta-type wholly aromatic polyamide fiber as claimed in 6, wherein in the step (3), the fibrous material is subjected to the heat treatment at a stretching ratio of from 0.7 to 5.0 times in saturated steam of from 0.02 to 0.50 MPa.
The method for producing a meta-type wholly aromatic polyamide fiber as claimed in 5, wherein in the step (4), the fibrous material is subjected to the dry heat treatment at a stretching ratio of from 0.7 to 4.0 times at a temperature of from 250 to 400° C.
The method for producing a meta-type wholly aromatic polyamide fiber as claimed in 6, wherein in the step (4), the fibrous material is subjected to the dry heat treatment at a stretching ratio of from 0.7 to 4.0 times at a temperature of from 250 to 400° C.
The method for producing a meta-type wholly aromatic polyamide fiber as claimed in 7, wherein in the step (4), the fibrous material is subjected to the dry heat treatment at a stretching ratio of from 0.7 to 4.0 times at a temperature of from 250 to 400° C.
The method for producing a meta-type wholly aromatic polyamide fiber as claimed in 5, wherein as the polymer solution subjected to wet spinning, a meta-type wholly aromatic polyamide solution is used that contains calcium chloride and water formed through neutralization of hydrogen chloride by-produced after reacting an aromatic diamine and an aromatic dicarboxylic chloride in the presence of an amide solvent.
The method for producing a meta-type wholly aromatic polyamide fiber as claimed in 6, wherein as the polymer solution subjected to wet spinning, a meta-type wholly aromatic polyamide solution is used that contains calcium chloride and water formed through neutralization of hydrogen chloride by-produced after reacting an aromatic diamine and an aromatic dicarboxylic chloride in the presence of an amide solvent.
The method for producing a meta-type wholly aromatic polyamide fiber as claimed in 7, wherein as the polymer solution subjected to wet spinning, a meta-type wholly aromatic polyamide solution is used that contains calcium chloride and water formed through neutralization of hydrogen chloride by-produced after reacting an aromatic diamine and an aromatic dicarboxylic chloride in the presence of an amide solvent.
Dependencies are inferred from the claim text.