Method for Dyeing Aramid Fibers and Dyed Aramid Fibers

a technology of aramid fibers and dyeing methods, which is applied in the direction of dyeing process, fiber treatment, textiles and paper, etc., can solve the problems of insufficient colorfastness of the obtained dyed product, inability to obtain color depth, and limited hue of dope-dyed fibers, so as to improve dyeing quality and color depth, good colorfastness, and improve dyeing quality

Inactive Publication Date: 2014-01-23
TOKAI SENKO KK
View PDF9 Cites 4 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Benefits of technology

[0022]According to the present invention, the method can be applied to either of the para-type aramid fibers, the para-type copolymerized aramid fibers or the meta-type aramid fibers, and can dye these aramid fibers with a practical color depth. Also, according to the present invention, color unevenness or dimensional change, or lowering in physical properties is not markedly generated in the aramid fibers after the dyeing. Moreover, since a vat dye or a sulfur dye having good colorfastness, in particular, colorfastness to light is used, colorfastness, in particular, colorfastness to light of the dyed aramid fibers becomes good.
[0023]In addition, by changing a used concentration and hue of the vat dye or the sulfur dye to be used, a dyed product from a pale color to a dark color with various hues can be obtained. In particular, according to the present invention, the para-type aramid fibers or the para-type copolymerized aramid fibers can be dyed with a very dark color such as black and navy blue which had been deemed to be difficult.
[0024]Here, as one of the methods to evaluate a dark color such as black and navy blue, there is lightness (L* value) in a L*a*b* colorimetric system which had been standardized by International Commission on Illumination (CIE) in 1976, and in Japan, it had been adopted in JIS Z8729. This L* value is shown in the range of 100 (white) to 0 (black), and a smaller L* value can be evaluated to be a dark color.
[0025]For example, in the dope-dyed fibers of the commercially available meta-type aramid fibers or para-type copol

Problems solved by technology

These aramid fibers have rigid molecular structure and high crystallinity, and a practical color depth cannot be obtained by the same dyeing method as applied to the general fibers, and colorfastness of the obtained dyed product cannot be said to be practically sufficient.
Such dope-dyed fibers are limited in hue, so that there is the problem that they cannot sufficiently correspond to various hues required for developing new applications of various kinds of protective working clothes or aramid fibers.
Moreover, in the para-type aramid fibers or the para-type copolymerized aramid fibers, and also including the dope-dyed fibers, fibers having a pra

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Examples

Experimental program
Comparison scheme
Effect test

first embodiment

(1) First Embodiment

[0036]The dyeing method according to the first embodiment comprises a dye providing step in which a vat dye or a sulfur dye is provided to the aramid fibers, and a solvent treatment step in which the aramid fibers are treated by a treating solution containing a polar solvent. The order of these dye providing step and solvent treatment step is not particularly limited, and it is preferred to carry out the solvent treatment step after the dye providing step. In this first embodiment, the dye providing step in which the vat dye or the sulfur dye is provided to the aramid fibers in a non-reduced state is firstly carried out, subsequently the solvent treatment step in which the aramid fibers to which the vat dye or the sulfur dye had been provided are treated by a treating solution containing a polar solvent is carried out.

[0037]In this first embodiment, these series of steps are generically called as “dyeing operation 1”. Incidentally, this dyeing operation 1 (dye pr...

second embodiment

(2) Second Embodiment

[0062]The dyeing method according to this second embodiment comprises a dye providing step in which the vat dye or the sulfur dye is provided to the aramid fibers, a solvent treatment step in which the aramid fibers are treated by a treating solution containing a polar solvent, and a heat treatment step in which the aramid fibers after the solvent treatment step are subjected to the heat treatment. In this second embodiment, these series of the steps are generically called to as “dyeing operation 3”. Incidentally, the dyeing operation 3 (dye providing step→solvent treatment step→heat treatment step) may be carried out only once, or may be repeated a plural number of times, depending on necessity. By repeating this dyeing operation a plural number of times, aramid fibers with a denser color can be obtained.

A. Dye Providing Step

[0063]The dye providing step in this second embodiment is carried out the same operations as those of the dye providing step in the above-...

third embodiment

(3) Third Embodiment

[0074]The dyeing method according to this third embodiment has a pre-dyeing step which dyes the aramid fibers with a dye other than the vat dye and the sulfur dye before the dyeing operation 1 or the dyeing operation 3 explained in the above-mentioned first embodiment or the above-mentioned second embodiment. Incidentally, the above-mentioned dyeing operation 1 or the dyeing operation 3 carried out after the pre-dyeing step may be carried out once alone, or may be repeated a plural number of times, depending on necessity. By repeating the dyeing operation 1 or the dyeing operation 3 a plural number of times, aramid fibers with a denser color can be obtained.

D1. Pre-Dyeing Step

[0075]In the dyeing method according to this third embodiment, a pre-dyeing step is firstly carried out to the undying aramid fibers. In this pre-dyeing step, a dyeing solution containing a dye other than the vat dye and the sulfur dye is used. The dyeing method of the pre-dyeing step may be...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

PropertyMeasurementUnit
Pressureaaaaaaaaaa
Coloraaaaaaaaaa
Solubility parameteraaaaaaaaaa
Login to view more

Abstract

Methods for dyeing aramid fibers, and the dyed arimid fibers produced by these methods, which comprises a dye providing step in which a vat dye or a sulfur dye is provided to aramid fibers, a solvent treatment step in which the aramid fibers are treated by a treating solution containing a polar solvent, and after the solvent treatment step, a heat treatment step in which the aramid fibers are subjected to a heat treatment, if necessary, and having one or more dyeing operations comprising the combination of the respective steps dyeing operations. The dyeing methods can be applied to either of the para-type aramid fibers, the para-type copolymerized aramid fibers and the meta-type aramid fibers, which can be dyed to a practical color depth required for developing new applications of the aramid fibers. Colorfastness of the dyed product, in particular, colorfastness to light, is improved.

Description

TECHNICAL FIELD[0001]The present invention relates to a method for dyeing aramid fiber, in particular, to a method for dyeing which can dye the aramid fibers with a practical color depth. The present invention also relates to aramid fibers dyed by the method.BACKGROUND ART[0002]A wholly aromatic polyamide fiber is also called as an aramid fiber, which has high strength and high modulus of elasticity, and excellent heat resistance, dimensional stability, chemical resistance, etc., and has been used for wide uses as industrial use fibers. The aramid fibers can be roughly classified into three kinds of para-type aramid fibers (polyparaphenylene terephthalamide fiber, etc.), para-type copolymerized aramid fibers (copolymerized fibers with polyparaphenylene terephthalamide and 3,4′-oxydiphenyleneterephthalamide), and, meta-type aramid fibers (polymetaphenylene isophthalamide fibers or copolymerized fibers containing the same as a main component, etc.) depending on the position of an amid...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
IPC IPC(8): D06P5/22
CPCD06P5/22D06P1/22D06P1/30D06P3/243D06P5/001D06P5/02D06P3/24D06P5/04
Inventor OIWA, NORIHIROIMAI, KAZUKISAYAMA, SHOHEIITO, TAKAHIROYASUI, AKIRA
Owner TOKAI SENKO KK
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap