JPH0615741B2 - Method for producing modified polyester fiber - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION a. Field of Application The present invention relates to a method for producing modified polyester fibers. More specifically, it is a method for producing a modified polyester fiber which can be dyed with a basic dye and is excellent in alkali resistance.

b. 2. Description of the Related Art Polyester is widely used as a fiber because it has many excellent properties, but it has low dyeability and is difficult to be dyed with dyes other than disperse dyes. Various proposals have been made to improve the dyeability, and one of them is a method of dyeing with a basic dye by copolymerizing an isophthalic acid component containing a metal sulfonate group in the polyester main chain. Are known.

On the other hand, in order to impart a silky soft and good feel to a woven or knitted fabric made of polyester fibers, a method of performing alkali weight loss treatment is known, and in this case, the weight loss is about 20% by weight.

By this method of alkali weight reduction treatment, in a woven or knitted fabric in which a regulatable polyester fiber and the basic dye dyeable polyester fiber are woven or knitted with the aim of producing a different color dyeing effect and marbling effect at the same time with a good texture, When the alkali weight reduction processing of about 20% by weight is performed, there is a drawback that the basic dye-dyeable polyester fiber is almost decomposed.

That is, the basic dye dyeable copolyester fiber,
When the alkali weight reduction treatment which is usually performed to improve the texture of the woven or knitted product is performed, the dissolution rate of the fibers by the alkali is extremely high, and the conditions usually used in industry (for example, 3% water at 100 ° C.) are used. Not only is it difficult to perform stable weight loss treatment with a sodium oxide solution),
Since the strength of the alkali-treated yarn is remarkably lowered, it is difficult to apply the alkali weight-reducing process.

Furthermore, in the case of the polyester copolymerized with the above-mentioned 5-metal sulfone sophthalic acid component, a polyester oligomer in which a large amount of 5-metal sulfoisophthalic acid component is copolymerized during the polycondensation reaction is unavoidable as a foreign substance. To live,
Compared to regular polyester, the amount of foreign matter in the polymer was large, and there were problems in production such as an increase in the packing pressure during spinning and a deterioration in the quality of the obtained yarn.

c. OBJECT OF THE INVENTION The inventors of the present invention have conducted extensive studies for the purpose of providing a polyester fiber which solves the above-mentioned problems, and as a result, one ester such as an m-metal sulfobenzoic acid compound was used as a basic dye dyeable agent. By using a sulfonate compound having a forming functional group, the polyester fiber finally obtained exhibits excellent basic dye dyeability, the alkali weight loss rate is remarkably reduced, and the yarn due to the alkali weight loss is produced. I found that the above problems can be solved by reducing the strength significantly, and I made a proposal earlier. The present invention has been further studied based on such findings, and as a result, instead of the above-mentioned benzene ring sulfonate compound having an ester-forming functional group, a naphthalene ring sulfonate compound having one ester-forming functional group or It has been found that by using a diphenyl ring sulfonate compound having one ester-forming functional group, the rate of alkali weight reduction is further reduced, and the decrease in yarn strength due to alkali weight reduction is further reduced. The present invention has been completed as a result of further studies based on such findings.

d. Structure of the Invention That is, the present invention provides the following general formula (I) and / or (II) A method for producing a modified polyester fiber, which comprises subjecting a fiber composed of polyester of which at least a part of the end is blocked with a compound represented by

The polyester referred to in the present invention is a polyester containing terephthalic acid as a main acid component and at least one glycol, preferably at least one alkylene glycol selected from ethylene glycol, trimethylene glycol and tetraethylene glycol as a main glycol component. Is the main target.

Further, it may be a polyester in which a part of the terephthalic acid component is replaced with another difunctional carboxylic acid component, and /
Alternatively, it may be a polyester in which a part of the glycol component is replaced with the above glycol other than the main component or another diol component.

Examples of the bifunctional carboxylic acid other than terephthalic acid used here include isophthalic acid, naphthalene dicarboxylic acid, diphenyldicarboxylic acid, diphenoxyethanedicarboxylic acid, β-hydroxyethoxybenzoic acid, p-oxybenzoic acid, Aromatic, aliphatic, and alicyclic bifunctional carboxylic acids such as adipic acid, sebacic acid, and 1,4-cyclohexanedicarboxylic acid can be mentioned. Further, isophthalic acid having a metal sulfonate group such as 5-sodium sulfone isophthalic acid may be used as a copolymerization component within a range in which the effect of the present invention is substantially exhibited.
It is desirable to limit the amount used to less than 1.8 mol% with respect to the terephthalic acid component.

Examples of diol compounds other than the above glycols include aliphatic, alicyclic and aromatic diol compounds such as cyclohexane-1,4-dimethanol, neopentyl glycol, bisphenol A and bisphenol S, and polyoxyalkylene glycol. Etc. can be given.

Further, polycarboxylic acids such as trimellitic acid and pyromellitic acid, and polyols such as glycerin, trimethylolpropane and pentaerythritol can be used in the range where the polyester is substantially linear.

Such polyester may be synthesized by any method. For example, polyethylene terephthalate will be described. Usually, terephthalic acid and ethylene glycol are directly esterified, or a lower alkyl ester of terephthalic acid such as dimethyl terephthalate is transesterified with ethylene glycol, or terephthalic acid and ethylene glycol are used. The first step reaction of reacting with oxide to form a glycol ester of terephthalic acid and / or its low polymer, and heating the reaction product of the first step under reduced pressure until a desired degree of polymerization is reached. It is produced by the second stage reaction of polycondensation reaction.

In the present invention, at least a part of the ends of the polymer chain made of the above polyester has the following general formula (I) and / or
Or (II) It must be blocked with a compound represented by.

In the above formulas (I) and (II), A ¹ , A ² and A ³ represent ester-forming functional groups, and specific examples thereof include (However, R'is a lower alkyl group or a phenyl group, j is an integer of 1 or more, and k is an integer of 2 or more) and the like. The A ¹ , A ² and A ³ may be the same or different. R ¹ , R ² and R ³ are a hydrogen atom, a hydroxyl group, an alkyl group or a halogen atom, and when being an alkyl group, they may be linear or have a branched side chain. The alkyl group preferably has 1 to 30 carbon atoms, and particularly preferably 1 to 4 carbon atoms. As a halogen atom
Cl and Br are preferred. It is particularly preferable that R ¹ , R ² and R ³ are hydrogen atoms or alkyl groups. This R ¹ , R ² and
Each R ³ may be the same or different intramolecularly or intermolecularly. M ¹ , M ² and M ³ are metals, and among them, alkali metals are preferable. Each of M ¹ , M ² and M ³ may be the same or different within a molecule or between molecules.

As a preferred specific example of such a compound, 6-sodium sulfo-1-naphthoic acid (or its methyl ester, β-
Hydroxyethyl ester or δ-hydroxybutyl ester), 5-sodium sulfo-1naphthoic acid (or its methyl ester, β-hydroxyethyl ester or δ-hydroxybutyl ester), 6-sodium sulfo-2-naphthoic acid (or its Methyl ester, β-hydroxyethyl ester or δ-hydroxybutyl ester), 7-sodium sulfo-2-
Naphthoic acid (or its methyl ester, β-hydroxyethyl ester or δ-hydroxybutyl ester), 6-lithium sulfo-1-naphthoic acid (or its methyl ester, β-hydroxyethyl ester or δ-hydroxybutyl ester), 6 -Potassium sulfo-1-naphthoic acid (or its methyl ester, β-hydroxyethyl ester, δ-hydroxybutyl ester), 3-sodium sulfodiphenyl-4'-carboxylic acid (or its methyl ester, β-hydroxyethyl ester) Or δ-hydroxybutyl ester), 4
-Sodium sulfodiphenyl-4'-carboxylic acid (or its methyl ester, β-hydroxyethyl ester or δ-hydroxybutyl ester), 4-sodium sulfodiphenyl-2'-carboxylic acid (or its methyl ester, β- Hydroxyethyl ester or δ-hydroxybutyl ester), 3-sodium sulfodiphenyl-2'-carboxylic acid (or its methyl ester, β-hydroxyethyl ester or δ-hydroxybutyl ester), 4-sodium sulfodiphenyl-4 Examples thereof include ′-(β-hydroxyethyl ester) and the like.

In order to block the end of the polyester chain with the above compound, the above compound is added at any stage before the completion of the above-mentioned polyester synthesis, preferably at any stage before the completion of the reaction in the first stage. Good. At this time, if the amount used is too small, the dyeing seat in the finally obtained polyester fiber will be insufficient, resulting in insufficient dyeability for basic dyes. Conversely, if it is too large, it will occur in the polycondensation reaction process. Since the degree of polymerization of the polyester reaches a ceiling at a level that is too low, yarn properties such as strength of the finally obtained polyester fiber are deteriorated. Amounts in the range of 5 to 5.0 mol% are preferred.

A large amount of ether bonds may be produced as a by-product when such a terminal-blocking compound is used, but this drawback is described in JP-A-48-66650.
It can be avoided by adding an alkali metal compound as disclosed in Japanese Patent Publication No. 53-28955.

In order to use the modified polyester dyeable with the basic dye thus obtained as a fiber, it is not necessary to employ a particular method, and a general melt-spinning method for polyester fiber is arbitrarily adopted. The fibers spun out here may be solid fibers having no hollow portion or hollow fibers having a hollow portion. The outer shape of the fiber to be spun in cross section and the shape of the hollow portion may be circular or irregular.

The modified polyester fiber thus obtained is subjected to a stretching heat treatment or a false twisting process, if necessary, or further made into a cloth, and then subjected to an alkali weight reduction treatment.

The alkali weight reduction treatment uses, for example, an alkaline compound such as sodium hydroxide or potassium hydroxide as an aqueous solution,
Well-known methods such as a pad method, a spray method, a method of attaching and then heating by a dipping method, a method of attaching and hanging in the atmosphere after the attachment are used. Alkali concentration is usually 1 to 30
The range of 0 g / is preferable, and the processing temperature is from room temperature to 100 ° C.
Is preferred. A carrier or the like may be added as an alkali treatment accelerator. Weight loss due to alkali is 5-4
About 0% is practical.

e. EFFECTS OF THE INVENTION As described above, in the present invention, since a terminal blocking agent having a specific metal sulfonate group is used as a modifier, a basic dye dyeing modification which is usually used industrially is used. When a 5-metal sulfoisophthalic acid compound, which is an agent, is used, the compound is copolymerized into the polyester main chain, whereas the modifier is introduced into the polyester chain terminal by a chemical bond. This difference appears as a remarkable difference in alkali decomposition resistance. Although the reason for this is not yet clear, in the conventional method, the hydrolysis of the main chain of the polyester is significantly reduced because the main chain of the polyester is cleaved by alkali hydrolysis, whereas in the method of the present invention, hydrolysis at the end of the polyester chain is caused. Therefore, there is practically no decrease in the degree of polymerization, and the naphthalene ring sulfonate compound or diphenyl ring sulfonate compound bonded to the polyester chain end acts as a so-called boat rope model boat, and the boat effect Is larger than that of the benzene ring sulfonate compound, so that it seems to be related to the formation of an extremely tight fiber structure during the melt spinning or drawing process.

Based on such characteristics, the present invention has the following effects.

(1) The modified polyester fiber obtained by the method of the present invention is dyeable with a basic dye and has excellent alkali resistance. Therefore, it is possible to apply a usual alkali weight reduction treatment for improving the texture of the woven or knitted fabric.

(2) Since the alkali weight loss rate comes close to that of the regular polyester fiber, the basic dye-dyeable polyester fiber and the regular polyester fiber obtained by the method of the present invention are woven or knitted into a woven or knitted product. By carrying out the alkali weight reduction treatment after that, a woven or knitted fabric having a silky soft and good texture and capable of expressing a high-level dyeing effect such as a different color dyeing effect and a marbling effect can be obtained.

(3) The modified polyester fiber obtained by the method of the present invention is resistant to high temperatures, and even in dyeing at 130 ° C., for example, strength reduction and shrinkage do not become a problem, and it is easy to get out.

(4) Further, according to the method of the present invention, the amount of foreign matter produced as a by-product during the polymerization is small, so that the effect of increasing the packing pressure during spinning and the deterioration of the obtained yarn quality is small.

In addition, the polyester fiber obtained by the method of the present invention may contain any additive such as a catalyst, an anti-coloring agent, a heat-resistant agent, a flame retardant, a brightening agent, a matting agent, and a coloring agent, if necessary. May be included.

f. [Examples] Examples will be further described below. Parts and% in the examples mean parts by weight and%.

Example 1 100 parts of dimethyl terephthalate, ethylene glycol 6
6 parts, methyl 6-sodium sulfonaphthalene-2-carboxylate in the amount described in Table 1 (varied amount in the range of 0 to 5.2 parts. This amount range was 0 with respect to dimethyl terephthalate. To 3.5 mol%), manganese acetate tetrahydrate 0.03 part (0.024 mol% with respect to dimethyl terephthalate) and sodium acetate trihydrate 0.112 as an ether formation inhibitor. Part (0.16 mol% with respect to dimethyl terephthalate) was charged into a transesterification can and heated from 140 ° C. to 230 in a nitrogen gas atmosphere for 4 hours.
The temperature was raised to 0 ° C. and the produced methanol was distilled out of the system to carry out a transesterification reaction. Subsequently, 0.03 parts of a 56% aqueous solution of orthophosphoric acid (0.033 mol% based on dimethyl terephthalate) and 0.04 part of ammotine trioxide (0.027 mol%) were added to the obtained product. And transferred to a polymerization can. Then reduce the pressure from 760 mmHg to 1 mmHg over 1 hour, and simultaneously 230 ° C to 280 ° C over 1 hour 30 minutes.
The temperature was raised to. Polymerization temperature of 280 ℃ under reduced pressure of less than 1mmHg
Polymerization was carried out until the intrinsic viscosity shown in Table 1 was reached. The intrinsic viscosity and softening point of the obtained polymer are shown in Table 1.

The obtained polymer was dried by a conventional method, and a spinneret having 36 circular spinning holes with a hole diameter of 0.3 mm was used for 290
It was melt-spun at 0 ° C. and then stretched according to a conventional method to obtain a yarn of 75 denier / 36 filament.

The obtained raw yarn was made into a plain woven fabric having a weaving density of 27 warps / cm and 25 wefts / cm, and the woven fabric was refined by a conventional method and then treated with a 1.5% sodium hydroxide aqueous solution at a boiling temperature. A fabric having a weight loss rate of 20% was obtained.

Cloth after this alkali treatment is Cathilon Blue CD-FRLH / C
athilon Blue CD-FBLH = 1/1 (Hodogaya Chemical Co., Ltd.)
After dyeing at 130 ° C. for 60 minutes in a dyeing bath containing 2 g of mirabilite and 3 g of Glauber's salt / acetic acid and 0.3 g / l of the salt, soaping was carried out according to a conventional method to obtain a blue cloth.

Table 1 shows the alkali weight reduction treatment time required to reach the weight reduction rate of 20% in the alkali weight reduction treatment, the dyeability of the basic dye (x: not dyeable, Δ: dyeable, but dye exhaustion rate <99. %, ◯: Dye exhaustion rate ≧ 99%) and yarn strength reduction rate.

Here, the yarn strength reduction rate was compared with the strength of the multifilament obtained by unwinding the woven fabric before the alkali reduction treatment and the multifilament obtained by unwinding the woven fabric after the dyeing treatment after the alkali treatment.

Example 2 2.52 parts of methyl 6-sodium sulfonaphthalene-1-carboxylate in place of the methyl 6-sodium sulfonaphthalene-2-carboxylate used in Example 1 (1.7 mol% based on dimethyl terephthalate) In the same manner as in Example 1 except that (1) was used, transesterification reaction, polycondensation reaction, spinning, drawing, weaving, refining, presetting, alkali reduction treatment, basic dyeing, and soaping were performed. The results are as shown in Table 1.

Example 3 4.21 parts of methyl 4-sodium sulfodiphenyl-4'-carboxylate in place of the methyl 6-sodium sulfonaphthalene-2-carboxylate used in Example 1 (2.6 relative to dimethyl terephthalate. The same procedure as in Example 1 was carried out except that (mol%) was used. The results are shown in Table 1.

Example 4 In place of the methyl 6-sodium sulfonaphthalene-2-carboxylate used in Example 1, 3.67 parts of 6-sodium sulfonaphthalene-2-carboxylic acid (2.6 mol% based on dimethyl terephthalate) Was used and the addition time was after completion of the transesterification reaction. The results are shown in Table 1.

Example 5 6-sodium sulfonaphthalene-2-carboxylic acid δ
-Modified polybutylene terephthalate having an intrinsic viscosity of 0.720 and a softening point of 223 [deg.] C copolymerized with 1.8 mol% of hydroxybutyl ester was spun at a spinning temperature of 255 [deg.] C, and the temperature was 68 [deg.] C.
Was drawn by using a heating roller of No. 1 to obtain a yarn of 75 denier / 36 filament. Using this raw yarn, the following Example 1
Weaving, refining, presetting, alkali weight reduction,
Dyeing with a basic dye was performed.

The results are as shown in Table 1.

Comparative Example 1 6-sodium sulfonaphthalene used in Example 1
An intrinsic viscosity of 0.485 was carried out in the same manner as in Example 1 except that 4 parts of dimethyl 5-sodium sulfoisophthalate (2.6 mol% based on terephthaldimethyl) was used in place of methyl 2-carboxylate. A modified polyester having a softening point of 257 ° C. was obtained. Thereafter, spinning, drawing, and
Weaving, refining, presetting, alkali reduction treatment, and dyeing with basic dyes were performed. The results are shown in Table 1.

Comparative Example 2 6-sodium phonaphthalene-2-used in Example 1
The same procedure as in Example 1 was carried out except that 3.19 parts of methyl m-sodium sulfobenzoate (2.6 mol% based on dimethyl terephthalate) was used instead of methyl carboxylate. The results are shown in Table 1.

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Claims (2)

[Claims] 1. The following general formula (I) and / or (II) A method for producing a modified polyester fiber, which comprises subjecting a fiber composed of a polyester, at least a part of which is blocked with a compound represented by, to alkali reduction treatment. 2. The modified polyester fiber according to claim 1, wherein the blocked ends are in the range of 0.5 to 5 mol% with respect to the bifunctional carboxylic acid component constituting the polyester. Law.