JP2503989B2 - Modified polyester fiber - Google Patents

Description

TECHNICAL FIELD The present invention relates to a modified polyester fiber which is dyeable with a cationic dye, has high yarn strength, is excellent in alkali resistance, and has good light fastness.

(Prior Art) Aromatic polyesters typified by polyethylene terephthalate are widely used as fibers, films, and other molded products because they have excellent mechanical performance, light resistance, heat resistance, chemical resistance, and the like. . However, aromatic polyesters can be dyed only with disperse dyes, and have the drawbacks that it is difficult to produce vivid colors and that there is migration staining depending on the application.

In order to eliminate these drawbacks, aromatic polyester has 5
A method for modifying a cationic dye dyeable polyester by copolymerizing a compound having an acidic group such as sodium sulfoisophthalic acid is known from Japanese Patent Publication No. 34-10497. However, according to this method, in order to obtain a practical level of dyeability, a large amount of the isophthalic acid component (S component) containing a metal sulfonate group must be copolymerized so as to be usually 2 mol or more. Since such a large amount of copolymerization of the S component increases the viscosity of the S component, it is melt-polymerized into a polymer having a degree of polymerization capable of showing sufficient strength as a fiber,
When spinning is attempted, the melt viscosity becomes too high, which makes polymerization and spinning difficult. Therefore, in order to carry out polymerization / spinning by a usual method, it is necessary to reduce the melt viscosity to a range where ordinary polymerization or spinning can be carried out, and the degree of polymer polymerization must be lowered. As a result, the tenacity of the obtained yarn is lowered, and its use is limited. Further, the copolymerization of a large amount of S component deteriorates the hydrolysis resistance of the product, which also limits its use. In particular,
Alkali weight loss treatment, which is widely performed on polyester filament products, shows a remarkably fast alkali weight loss rate, which is a major problem in process control and product quality.

While imparting dyeability to the cationic dye, the S component is added in an amount of 0.8 to 1.8 in order to suppress such defects due to the copolymerization of the S component as much as possible and maintain the original physical properties of the polyester fiber as much as possible.
It is limited to mol% in JP-A-58-126376,59-30903,5.
9-47485, 59-66580, 59-71487, 59-71488, 59-76987 and the like. However, if the S component is limited to 2 mol% or less, the dyeability is unavoidably deteriorated, and the use thereof is limited in terms of the dyeability such that a dark color cannot be obtained.

In order to improve the above-mentioned problems, a method is known in which the S component is decreased and an acid component such as isophthalic acid or adipic acid is copolymerized in order to make up for the deterioration of the dyeing property resulting therefrom (Japanese Patent Laid-Open No. 57-57242). -66119), the melting point of the obtained polyester is remarkably lowered and the heat resistance of the product is insufficient, which causes another problem. It is also known that copolymerizing a polyester with a high molecular weight polyoxyethylene glycol or a homologue thereof is effective for facilitating dyeing and does not significantly lower the melting point of the obtained polyester (JP-A-57- 63325), the biggest drawback of this modified polyester is that the dyestuff has very poor lightfastness. For this reason, JP-A-59-2652
In 1, the glycol component to be copolymerized is limited to 0.5 to 1.9% by weight. However, if the copolymerization amount of the easy-dyeing agent is limited to a certain amount or less, the dyeability cannot naturally be satisfied.

(Problems to be Solved by the Invention) The present invention has the above-mentioned conventional drawbacks in the cationic dye-dyeable polyester fiber, namely, low yarn strength, high hydrolysis property (fast weight loss rate, high weight loss rate) and poor light fastness. It is intended to provide a cationic dye-dyeable polyester fiber which solves the above problem and has a practical level of dyeability.

(Means for Solving Problems) The present invention has been achieved as a result of intensive research to solve the above problems. That is, the present invention is a polyester fiber containing ethylene terephthalate as a main component, and the physical properties of the raw yarn satisfy the following formula, The alkali weight loss rate of the raw yarn is in the range represented by the following formula, Moreover, the cationic dye dyeing ratio of the raw yarn is expressed by the following formula. It is a modified polyester fiber characterized by Here, the raw yarn means a fiber after spinning and drawing.

Specified in the present invention Is a numerical value generally referred to as "toughness" and indicates the substantial strength of the fiber.

If this value is 25 or less, the strength as a cloth for clothing such as work clothes and sports clothes to which excessive force is applied cannot be satisfied.

The alkali weight loss rate indicated by is a numerical value showing the ease of alkali hydrolysis of the fiber. If it is larger than the above, the weight loss rate difference with the regular polyester becomes large, and only the modified polyester is selectively reduced when the weight reduction treatment is performed by using it as a mixed product with the regular polyester. Also If it is larger than the above range, there is a drawback that the weight reduction rate is too fast and is easily affected by the variation in the alkali weight reduction treatment conditions.

In the present invention, the cationic dye dyeing ratio showing dyeability (easiness of dyeing) is Must be above. This is because if it is lower than this, sufficient dark color cannot be obtained.

80 mol% or more of the modified polyester of the present invention is terephthalic acid or its ester-forming derivative, and
0.75-1.2 mol% of dicarboxylic acid component consisting of 5-alkali metal sulfoisophthalic acid or its ester-forming derivative, 80 mol% or more and 99.1 mol% or less of glycol selected from ethylene glycol and tetramethylene glycol, and polyester produced 2.0 to 5.0% by weight
Which is a copolymerized polyester fiber obtained by melt-spinning a copolymerized polyester obtained from a glycol component consisting of a polyalkylene oxide-based glycol having a molecular weight of 200 to 400 and being stretched if necessary. Quality polyester fiber, and the glycol having a molecular weight of 200 to 400 is a glycol represented by the following general formula.

HOCH ₂ —CH ₂ —O _m R—O (CH ₂ —CH ₂ —O _n H (4) (wherein R is a divalent aliphatic or aromatic hydrocarbon group having 4 to 15 carbon atoms, m, n Are the same or different integers and have an average value of 1 ≦ m + n ≦ 6.5.) That is, when the S component is less than 0.75 mol%,
Since the dyeing seat itself for the cationic dye becomes thin, even if the copolymerization amount of the glycol component as an easy dyeing agent is increased, the dyeability satisfying the formula (3) cannot be obtained. On the other hand, when the S component exceeds 1.2 mol%, not only the fiber quality satisfying the formula (1) cannot be obtained at the polymerization degree of melt viscosity which can be spun by the usual method, but also the hydrolysis resistance is deteriorated. Therefore, the alkali weight loss characteristic satisfying the expression (2) cannot be satisfied. In addition, the copolymerization amount of polyalkylene oxide-based glycol as an easy dyeing agent is
If the amount is less than 2.0% by weight, sufficient dyeing effect cannot be obtained, and the formula (3) cannot be satisfied. If it exceeds 5.0% by weight, not only the light fastness is deteriorated but also the hydrolysis resistance is deteriorated, and the alkali weight loss property satisfying the formula (2) cannot be obtained.
Furthermore, when the molecular weight of this polyalkylene oxide-based glycol is less than 200, the amount of the glycol component distilled out of the system during the polymerization reaction increases due to its low boiling point, and the dyeing agent glycol The content ratio in the polyester with respect to the charged amount becomes low, and it is difficult to control the content. On the other hand, when the molecular weight exceeds 400, the influence on the light fastness becomes large, and 2% by weight or more of copolymerization for obtaining a sufficient dyeing effect cannot be performed. That is, a polyalkylene oxide-based glycol that is copolymerized as an easy dyeing agent has a molecular weight of 20.
Only when the copolymerization amount is limited to the range of 0 to 400 and the copolymerization amount of 2.0 to 5.0% by weight, it is possible to satisfy the practical balance of operability, dyeability and light fastness. Furthermore, it is preferable that the polyalkylene oxide-based glycol is a glycol represented by the general formula (4).
In the general formula (4), R is a divalent aliphatic or aromatic hydrocarbon group having 4 to 15 carbon atoms, and specific examples include (C
H ₂ ) ₄ , (CH ₂ ) ₆ and other linear aliphatic hydrocarbon groups, Aliphatic hydrocarbon group having a side chain, such as,, -CH ₂ - -
Examples thereof include hydrocarbon groups having an aliphatic ring such as CH ₂ — and aromatic hydrocarbon groups such as, among which aliphatic groups having a side chain are particularly preferable.

The glycol represented by the general formula (4) can be synthesized by adding ethylene oxide to the glycol represented by HO-R-OH by a conventional method. It should be noted that those to which other alkylene oxides such as propylene oxide are added may be used in combination as long as the effects of the present invention are not impaired.

HO-R-OH in which both m and n are O in the general formula (4)
In the case of a glycol or a modified glycol mixture in which the average value of m + n is less than 1, there are various drawbacks related to the above-mentioned distillation and the melting point of the obtained polyester is low, and m + n ≧ 1 is required. Is. On the other hand, m
When + n exceeds 6.5 as an average value, the polyester dyed product obtained is markedly deteriorated in light resistance and is not practical, which is not preferable.

The preferable range is 2 ≦ m + n ≦ 6, and more preferably 3 ≦ m + n ≦ 6. In addition, as long as the effect of the present invention is not impaired, a small amount of glycol represented by HO-R-OH or glycol of m + n> 10 in the general formula (I) may be contained, and the above HO-R- In addition to the glycol represented by OH, a small amount of ethylene glycol, triethylene glycol, propylene glycol, 1,4-bis (β-hydroxyethoxy) benzene, bisphenol A, diphenylsilanol, etc. may be used within a range that does not impair the effects of the present invention. Can be used. A branching agent such as pentaerythritol or pyromellitic acid may be copolymerized to such an extent that the moldability of polyester is not impaired.

The copolyester forming the fiber of the present invention is a normal polyester such as a method of transesterifying dicarboxylic acid ester and glycol and then polycondensation reaction, or a method of esterifying dicarboxylic acid and glycol and then polycondensation reaction. It is obtained according to the production method, but when a method of obtaining a polyester through an esterification reaction is adopted, it is possible to add a glycol represented by the general formula (4) between immediately before the end of the esterification reaction and before the start of the polycondensation reaction. It is particularly preferable in that the decomposition of ether bond is suppressed. When terephthalic acid or an ester-forming derivative thereof and 5-metal sulfoisophthalic acid or an ester-forming derivative thereof are used as the dicarboxylic acid, they may be simultaneously reacted, or these dicarboxylic acid components may be separately reacted. The two may be mixed in the polycondensation reaction step after reacting with the glycol component.

(Examples) The present invention will be specifically described below with reference to examples, but parts in the examples mean parts by weight. In addition, the measuring method of the characteristic value in an Example is as follows. (Determination of abundance of glycol component and S component represented by formula (4) in polymer) The glycol component was quantified by a method of quantifying H atom weight by NMR, and the S component was quantified by fluorescent X-ray.

DT and DE are the breaking strength (g / d) and breaking elongation (%) of the finished yarn measured by Tensilon, respectively.

(Alkali weight loss rate) The sample was treated with a 60g / l caustic soda solution at a bath ratio of 1:30
The weight loss rate (%) was measured after treatment at 0 ° C for 60 minutes.

(Dyeing rate) Sample is Estrol Blue N-3RL (Thion dye; manufactured by Sumitomo Chemical Co., Ltd.) 1.5% owf, acetic acid 0.2 g / l, sodium acetate 0.2 g
After dyeing at a bath ratio of 1:50 at a bath ratio of 1:50 at 130 ° C. for 60 minutes, hydrosulfite 2 g / l and caustic soda 2 g / l were subjected to reduction washing at 80 ° C. for 20 minutes, washed with water and dried.

After this, the dyed product is faded using an o-meter
Photobleaching was performed according to JIS L-1044, and the grade was determined based on the blue scale.

Examples 1-4, Comparative Examples 1-8 Dimethyl terephthalate (DMT) 1000 parts, 5-sodium sulfoisophthalic acid dimethyl ester (DSN: S component) predetermined amount, ethylene glycol (EG) 700 parts and general formula (4) R is a 2,2-dimethylpropylene group and a predetermined amount of glycol of m + n = 4 is placed in an ester exchange reactor, to which 0.38 part of zinc acetate dihydrate and 0.50 part of sodium acetate (however, when DSN is not added, 0 Part) and antimony trioxide (0.33 part),
The ester exchange reaction was carried out while elevating the temperature over 0 minutes and distilling off the by-product methanol. To this reaction system was added 17 parts of 22% titanium dioxide EG dispersion, and diethyl-2 was added.
1 by adding 0.8 parts of carboethoxyethylphosphonate
Hold for 0 minutes. The obtained product was transferred to a polycondensation can at 210 ° C., the internal temperature was raised to 210 to 275 ° C. in 80 minutes, the system was gradually depressurized, and then the polycondensation reaction was performed at 275 ° C. and 0.1 mmHg. About 40
By carrying out for a minute, a copolyester having a predetermined composition was obtained. This copolymerized polyester was spun by an extrusion type spinning machine at a spinning temperature of 290 ° C. and a winding speed of 900 m / min. The obtained unstretched yarn is stretched by a conventional method to obtain a stretched filament of 75 denier / 24 filament, knitted into an interlock having a basis weight of 200 g / m ² , and after refining, DT × DE by the above method, The alkali weight loss rate, dyeing rate and light fastness were measured. The results and the copolymerized polyester composition are shown in Table 1.

From the results in Table 1, it can be seen that the modified polyester fiber obtained by the method of the present invention has excellent mechanical properties and practical dyeing property, and at the same time has a mild alkali weight loss property and a good light fastness.

On the other hand, the comparative example No fiber satisfying all of the above conditions was obtained.

(Effect of the Invention) According to the present invention, there is provided a cationic dye-dyeable polyester fiber having excellent strength properties, alkaline hydrolysis property similar to regular polyester, and dyeing property.

Claims (1)

(57) [Claims] 1. A polyester fiber containing ethylene terephthalate as a main component, the physical properties of the raw yarn satisfying the following formula (1), The alkali weight loss rate of the raw yarn is in the range represented by the following formula (2). In addition, the dyeing ratio of the cationic dye of the raw yarn is represented by the following formula (3). A modified polyester fiber represented by
Dicarboxylic acid component consisting of mol% or more of terephthalic acid or its ester forming derivative and 0.75 to 1.2 mol% of 5-alkali metal sulfoisophthalic acid or its ester forming derivative, and 80 mol% or more and 99.1 mol% or less of ethylene glycol , A glycol selected from tetramethylene glycol, and 2.0 for the resulting polyester
It is obtained by melt-spinning a copolyester obtained from a glycol component consisting of a polyalkylene oxide-based glycol represented by the following general formula (4) having a molecular weight of from 200 to 5.0% by weight and having a molecular weight of 200 to 400 and, if necessary, stretching. A modified polyester fiber characterized in that _{HOCH 2 -CH 2 -O m R-} OCH 2 -CH 2 -O n H (4) ( wherein, R is a divalent aliphatic or aromatic hydrocarbon group having 4 to 15 carbon atoms, m, n Are the same or different integers and 1 ≦ m + n ≦ 6.5 as an average value.)