JPH05321162A - Meta-type aramid fiber dyed with cationic dye - Google Patents

Abstract

PURPOSE:To obtain the subject well-dyed fibrous product excellent in fastness by dyeing meta-type aramid fibers using a dyeing bath having a cationic dye- contg. dyeing solution incorporated with a substituted cinnamic acid. CONSTITUTION:The objective dyed product having the above-mentioned advantages can be obtained by dyeing (e.g. at 130-170 deg.C) meta-type aramid fibers (poly-m-phenylene isophthalamide-based ones) using a dyeing bath having a cationic dye-contg. dyeing solution incorporated with a substituted cinnamic acid (pref. p-methoxycinnamic acid).

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a cationic dyed meta-aramid fiber characterized by containing a cationic dye and a substituted cinnamic acid.

[0002]

2. Description of the Related Art Polymetaphenylene isophthalamide fiber (hereinafter abbreviated as meta type aramid fiber) has excellent heat resistance, flame resistance and chemical resistance, but its molecular chain is extremely small. Since it is rigid and has high crystallinity, dyeability was extremely difficult. The conventional method for dyeing meta-aramid fibers is (1) a method of using a large amount of a carrier such as acetophenone or paraphenylphenol and dyeing at high temperature and high pressure (for example, JP-A-58-87376). (2) A method of dyeing after pretreatment at room temperature with a solvent such as dimethylformaldehyde or dimethylsulfoxide (for example, JP-A-52-25178). (3) A method of heating and dyeing in a solvent such as dimethyl sulfoxide (for example, JP-A No. 62-268877).

However, since the method (1) uses a large amount of carrier, it is difficult to remove the carrier after dyeing, and the flameproofness is significantly adversely affected. In the method (2), ring dyeing is likely to occur, the original hue is not developed, and the light fastness is extremely poor. The method (3) cannot be produced at present because of the use of a large amount of flammable dangerous substances organic solvent, which requires a closed dyeing device.

Also, in these disclosed methods,
It tends to pollute the environment in terms of drainage, etc., which is not always sufficient from the standpoint of environmental protection.

[0005]

DISCLOSURE OF THE INVENTION An object of the present invention is to propose a meta type aramid fiber which is dyed in a dark color and with good light fastness by using an organic substance which easily diffuses a cationic dye into the fiber. It is a thing.

[0006]

The present invention is a "cationic dyeable meta-aramid fiber characterized by containing a cationic dye and a substituted cinnamic acid".

The meta-aramid fiber in the present invention is a fiber made of polymetaphenylene isophthalamide fiber or a copolymer containing it as a main component (for example, Conex registered trademark manufactured by Teijin Limited). Further, the fabric of the present invention, if necessary, in addition to the meta-aramid fiber, cotton,
It does not change even if it is used by blending with natural fibers such as wool, regenerated fibers such as rayon and acetate, and other synthetic fibers, mixed weaving, and knitting. The cationic dye is a dye that is soluble in water and used for synthetic fiber, and is often used for dyeing or coloring cationic dyeable polyester fiber or acrylic fiber.

It is roughly classified into two structural types. First, as a conjugated cationic dye, there are methine-based, polymethine-based, azamethine-based, azo-based, triazoleazo-based, thiazoleazo-based, benzothiazoleazo-based, triphenylmethane-based, etc. In the present invention, the dye base has a molecular weight of 250 to 500 or less. Further, the cation base of the cationic dye has only one positive ion. When the molecular weight of the dye base exceeds 500, it becomes poorly soluble in water and it becomes impossible to dye it evenly.

Further, the thermal decomposition resistance of the dye is 60 at 130 ° C.
It is preferable that the residual ratio of the dye after the treatment for at least 90% is required to be at least 90% or more. If the residual rate is less than 90%, the hue becomes unclear and the dyeing fastness is adversely affected.

Next, the dyeing temperature is required to be 110 ° C. or higher, preferably 130 ° C. or higher. If the dyeing temperature is less than 110 ° C, sufficient dyeing cannot be performed. The higher the dyeing temperature, the higher the dyeing property, but on the other hand, problems such as dye decomposition start to occur. Therefore, it is not always necessary to raise the temperature to 210 ° C. at the highest.

On the other hand, a substituted cinnamic acid is most suitable as a carrier as a dye diffusion agent. This substituted cinnamic acid has few ionic bonds with the cationic dye, and has good compatibility with the meta type aramid fiber, and facilitates diffusion and adsorption of the cationic dye into the fiber. Specific organic compounds include cinnamic acid, methoxycinnamic acid, alkylcinnamic acid,
There are halogenocinnamic acid. The position substituted on the benzene ring may be ortho, meta or para. In particular, the most preferred substituted cinnamic acid is paramethoxycinnamic acid.

The chemical formula is as shown in (I) below.

[0013]

[Chemical 1]

The residual amount of such an organic substance in the fiber is almost disappeared by reduction washing and heat treatment after dyeing, but the final amount is 50 mg / g (fiber weight) or less (measured by gas chromatograph).

[0015]

INDUSTRIAL APPLICABILITY The present invention comprises a meta-aramid fiber containing a cationic dye having a specific molecular weight and a trace amount of a substitution-type cinnamic acid, and can achieve an effect of high color development. This substitution-type cinnamic acid diffuses into the fine region inside the fiber with a small amount of addition to the dyeing bath, and at the same time, the dye is strongly dyed. When the dyeing is finished, the fine structure of the fiber returns to the original dense state, and the dyed dye does not easily fall off, and the fastness is high.

Next, the present invention will be described in detail with reference to examples. The evaluation methods referred to in the examples are as follows.

The evaluation of the cation dyeability is expressed by L * value, which is obtained from tristimulus values X, Y and Z obtained according to JIS Z8701 from diffuse reflectance, and the smaller the number, the deeper the dyeing. Indicates that

[0018]

Examples 1 and 2 Conex (registered trademark) having a spun yarn count of 40/2 obtained from 2 denier x 38 mm bias cut staple fibers was used as the meta-aramid fiber, and the warp density was 113 yarns / inch on a normal loom. Weft density 58 lines / inch 2
/ 1 twill was woven. The resulting fabric has a basis weight of 220 g
/ M ² . The fabric is then score rolled 90
0 (non-ionic activator, manufactured by Kao) 2 g / l and sodium carbonate 1 g / l.
After scouring for 30 minutes, heat treatment was performed at a temperature of 190 ° C. for 1 minute. The resulting fabric was dyed in the following dyebath at 130 ° C and 170 ° C for 60 minutes. Dye 6% owf Acetic acid 0.4 cc / liter Aromatic dicarboxylic acid ester 25 g / liter Bath ratio 1:30

The dyed fabric was subjected to reduction washing under the following conditions to remove the cationic dye adhering to the fiber surface. Caustic soda (flakes) 1 g / l Hydrosulfite 1 g / l Amylazine D (nonionic activator, Dai-ichi Kogyo Seiyaku) 1 g / l 80 ° C, 20 minutes Dye; Estrol Brill. Blue N-3RL Aromatic dicarboxylic acid ester; Paramethoxy Cinnamic acid After reduction cleaning, it was dried and heat-treated at 170 ° C. for 1 minute. The results are shown in Table 1.

[0020]

Comparative Example 1 The procedure of Example 1 was repeated except that paramethoxycinnamic acid was not added. The results are shown in Table 1.

[0021]

Comparative Example 2 The procedure of Example 1 was repeated except that acetophenone was used instead of paramethoxycinnamic acid of Example 1. The results are shown in Table 1.

[0022]

Comparative Example 3 Example 1 was repeated except that dichlorophenol was used in place of paramethoxycinnamic acid of Example 1.
It carried out similarly to. The results are shown in Table 1.

[0023]

[Table 1]

Claims (1)

[Claims] 1. A cationic dyed meta-aramid fiber comprising a cationic dye and a substituted cinnamic acid.