JPH01314790A - Dyeing of polyester fiber - Google Patents

Abstract

PURPOSE:To perform exhaustion dyeing of a polyester fiber with disperse dye in an alkaline solution in high reproducibility by adding an amino acid to the dyeing both. CONSTITUTION:A polyester fiber is dyed by exhaustion dyeing with a disperse dye in an aqueous medium of an alkaline state (especially, e.g., a one-bath scouring and dyeing process for scouring as well as dyeing), by adding an amino acid (preferably glycine, glutamic acid, etc.) to the dyeing bath in an amount of 0.02-0.4g/l and dyeing under high pressure by conventional method. The decomposition of the disperse dye is prevented by the addition of the amino acid to obtain a dyed fiber having excellent reproducibility.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for dyeing polyester fibers, and more particularly, to a method for dyeing polyester fibers in an alkaline region in an aqueous medium using a disperse dye. This invention relates to a dyeing method that prevents the decomposition of disperse dyes and performs dyeing with good reproducibility.

[Conventional technology]

Normally, when dyeing polyester fibers, spinning and
In order to eliminate harmful effects on the dyeing process caused by oils, glues, etc. used in spinning, weaving, etc. processes, oils, glues, etc. are removed from the fibers using a scouring device as a pre-process of the dyeing process. Generally, a scouring process is performed.

However, with the pursuit of energy and labor saving in recent years, various dyeing factories are considering bath scouring and dyeing, in which scouring and dyeing are carried out simultaneously as one of the rational dyeing methods.

Among these, if the target material is a polyester knitted fabric, only an oil agent is used and no glue agent is used, so it is only necessary to consider removing the oil agent, so it is recommended to consider it first. It is quite effective in processing, and although it is imperfect in some aspects, it is actually being processed in some areas.

However, for polyester fabrics, in addition to oil agents, glue agents (polyacrylic acid ester type) are used.

Since a large amount of polyvinyl alcohol (such as polyvinyl alcohol) is attached, it is necessary to remove the sizing agent at the same time as the oil agent, and surfactants that can remove both the sizing agent and the oil agent are being considered, but no effective one has been confirmed. Not yet.

On the other hand, normal scouring treatment uses a large amount of alkali,
It is indispensable for removing glue, but - bath scouring and
When alkali and disperse dye are used in the same bath during dyeing, if the temperature of the dye bath is raised to the dyeing condition after scouring, the high temperature will cause decomposition of the disperse dye due to the action of the alkali, making it difficult to put it to practical use as it is. It is. As a way to avoid this, we use chemicals that generate acidic substances when heated, treat with alkalinity during scouring, and increase the temperature of the dye bath during dyeing to slide the pH of the dye bath toward acidity.
Methods and agents have been proposed for dyeing disperse dyes without decomposing them under dyeing conditions. (For example, JP-A-Sho-Otsu 0-2
However, slight differences in the field conditions of the above-mentioned PH slide method affect the decomposition rate of the acid generator, and the reproducibility of the dyeing and scouring effects is affected. However, it has not been put into practical use because it is defective.

[Problem to be solved by the invention]

In view of the above-mentioned circumstances, the present inventors have developed a dyeing method that prevents the decomposition of the disperse dye when exhaust dyeing polyester fibers in an alkaline region in an aqueous medium using a disperse dye, and dyes polyester fibers with good reproducibility. As a result of extensive research, it was discovered that good results could be obtained by allowing amino acids to exist in the dye bath.

[Failure to solve the problem]

The gist of the present invention resides in a method for dyeing polyester fibers, which is characterized in that an amino acid is present in the dye bath when polyester fibers are exhaust dyed in an alkaline region in an aqueous medium using a disperse dye.

The present invention will be explained in more detail below.

Disperse dyes used in the present invention are not particularly limited, but include azo disperse dyes such as monoazo and disazo that are particularly susceptible to decomposition by the action of alkali, and substitutions in the dye structure that are susceptible to hydrolysis in an alkaline atmosphere. Dispersion of anthraquinone, phthalocyanine, copper formasan, etc. having groups such as an acetylamino group, a cyan group substituted on an aromatic ring, and an -OCO-R group (where R is an alkyl group of 01 to 3 or a phenyl group). Examples include dyes, and azo dyes are particularly advantageously used.

Examples of such dyes include dyes having the following structure.

The dyeing method is an exhaust dyeing method from an aqueous medium, and the present invention is based on the premise that the pH of the dyeing bath is in the alkaline range, and the suitable pH condition is in the range of g to /θ. stutter. That is, -5 = It is common knowledge that dyeing methods using ordinary disperse dyes are carried out in a weakly acidic region, but the present invention is directed only to dyeing in an alkaline region. As the pH adjuster, alkali metal compounds such as sodium hydroxide, potassium hydroxide, sodium carbonate, and sodium bicarbonate can usually be used, but sodium hydroxide is preferably used.

In the present invention, when exhaust dyeing polyester fibers in such an alkaline region, it is essential that amino acids be present in the dye bath. Types of amino acids include neutral amino acids, such as glycine, alanine, aminobutyric acid, aminocaproic acid, etc., acidic amino acids, such as aspartic acid, glutamic acid, etc., and basic amino acids, such as lysine, arginine, etc. Among them, glycine and glutamic acid are preferred. The amount of amino acid used is usually θ, 02~o
,ql! /l, preferably o, o s −o, λg/
The range is 1.

Fibers targeted by the dyeing method of the present invention include polyester fibers,
It can also be applied to woven, knitted or non-woven fabrics, threads, etc. made of polyester fibers and other fibers.

As the dyeing conditions, as mentioned above, the alkaline range, preferably PHg to 10, under pressure normally applied to dyeing polyester fibers, temperature /J, 0 to //IO°C can be adopted.

In addition, in the dyeing method of the present invention, post-processing treatments such as antistatic treatment and softening treatment, which are generally performed on fibers after dyeing according to ordinary dyeing methods, can also be carried out according to conventional methods. be.

According to the present invention, polyester fibers can be dyed well without being dyed.

Although the effects of such amino acids have not been fully analyzed,
At present, it is assumed that this is due to the dye decomposition prevention effect due to the buffering and chelating effects of amino acid compounds.

〔Example〕

EXAMPLES Hereinafter, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited in any way by the following description.

Examples/~S and Comparative Examples/A disperse dye mixture (plaque product) obtained by mixing disperse dyes represented by the following CA:], CB) and [C] in a ratio of Z:2:<Z (weight ratio) was used as an object to be dyed. The leveling agent DiaserVer L is used as a dyeing aid.
R-PSL (Mitsubishi Kasei Co., Ltd., product name) o, s g/l'
Amino acids were used as additives in the amounts listed in Table 1, and the pH of the dyebath was adjusted to 9. Polyester fabric Tropical (manufactured by Toshi Co., Ltd., trade name) was dyed at a bath ratio/near 0 and a dyeing temperature of 730° C. for 10 minutes.

In addition, the dye bath was carried out in the same manner as above, except that amino acids were not used as the criteria for evaluating dyed fabrics, and the pH was adjusted to 5.0 (weakly acidic) with acetic acid and sodium acetate, which is generally adopted for dyeing polyester fibers. Adjusted and stained (
Reference example).

The dyeing results of each dyed fabric were evaluated based on the dyed fabric obtained in the reference example, and are shown in Table 1.

The method for evaluating the dyed fabric is as follows.

(A) r [B] [C] <Evaluation method> Surface concentration - reflectance of dyed cloth was measured using a Macbeth spectrophotometer M
The K/S value was calculated using S-20-0, and expressed as a relative value when the value in the reference example was set as 100.

Color tone difference - reflectance of dyed cloth measured using Macbeth spectrophotometer MS
The hue difference ΔE for the dyed fabric obtained in the reference example was determined from CIEL*a*b*. The larger the value of ΔE, the more different the colors are, and as a guide for the difference in color of a dyed product, if ΔE is 7.0 or less, it is problematic.

As is clear from Table 7, compared to the case of dyeing at pHs, o, which is the usual dyeing condition for polyester fibers (reference example), the surface density was lower in the comparative example dyed at pH 9,5, and the color tone difference It can be seen that there is almost no change in the degree of largeness, and the difference in color tone is also small.

〔Effect of the invention〕

According to the present invention, the presence of amino acids in the dyeing bath prevents the decomposition of disperse dyes and allows dyeing of polyester fibers, which was conventionally carried out in a weakly acidic region, with good reproducibility in an alkaline region. is possible. Therefore, it not only becomes possible to perform one-bath scouring and dyeing of polyester fabrics, which was difficult with conventional techniques, but it will also be extremely important in pursuing rationalization studies such as process-saving, labor-saving, and resource-saving in the future.

In addition, when dyeing with alkaline conditions, the polynistyl oligomers that precipitate from inside the fiber into the dye bath under the dyeing conditions dissolve in the dye bath, so problems caused by the precipitated oligomers that were observed when dyeing with acidic conditions may occur. (tarling, dusting, etc.) can be prevented.

Applicant: Mitsubishi Kasei Corporation Representative Patent Attorney Naga Kagawa - (7 others)

Claims (1)

[Claims] (1) A method for dyeing polyester fibers, which is characterized by the presence of amino acids in the dye bath when exhaust dyeing polyester fibers in an alkaline region in an aqueous medium using a disperse dye.