JP2008163517A - Copolyester fiber and textile product using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a copolyester fiber having fiber physical properties of practicality, significantly improved stain resistance and its fastness to washing, especially remarkably improved darkening by washing and a textile product. <P>SOLUTION: The polyester fiber comprises a copolyester copolymerized with a polyether component in the side chain and contains 0.001-2 wt.% of a fluorescent brightener based on the weight of the fiber. The textile product is obtained by using the copolyester fiber in at least a part thereof. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to copolymerized polyester fibers and textile products. More particularly, the present invention relates to a copolymer polyester fiber and a fiber product having improved antifouling property, particularly recontamination property during washing.

Conventionally, polyester fibers are used in many fields because they have many excellent characteristics such as good dimensional stability, strongness, and resistance to wrinkles.
However, since polyester is hydrophobic, there are problems such as that oily soil is more likely to adhere and difficult to remove than hydrophilic fibers such as cotton, and that soil is more likely to reattach during washing. This re-contamination property has always been a problem since the practical use of polyester fibers, and many methods have been proposed to solve this problem.

  For example, a method of immersing a polyester molding in a solution or dispersion of a copolymer of polyethylene glycol and polyester resin (Patent Document 1), after padding or spraying a hydrophilic vinyl compound such as dimethacrylate of polyethylene glycolate A heat treatment method (Patent Document 2), a method using a low-temperature plasma treatment of a gas containing oxygen (Non-Patent Document 1), and the like are known.

  However, all of these methods have been proposed as finishing processing of polyester fiber products, and there are problems in processing such as complicated operation, special equipment, poor processing reproducibility, etc. In addition, there is a problem that the initial effect gradually disappears as the number of washings is repeated for clothes such as underwear and lab coats that are frequently washed. On the other hand, as an antifouling polyester fiber obtained by modifying the raw yarn, an antifouling polyester fiber obtained by copolymerizing one end-capped polyoxyethylene glycol at the end of the polyester main chain has been proposed (Patent Documents 1 and 2). . However, since the above-mentioned one-end-closed polyoxyethylene glycol acts as a so-called terminal terminator in the polyester polycondensation reaction, the final copolymer is obtained as the copolymerization amount of the one-end-blocked polyoxyalkylene glycol is increased. The problem that the polymerization degree of the polymerized polyester is lowered becomes apparent. For this reason, it is extremely difficult to obtain sufficient antifouling properties while maintaining practical fiber properties in this system (Patent Documents 3 to 6).

  Furthermore, antifouling polyester fiber structures and fiber products obtained by applying antifouling treatment as described above to fiber structures and fiber products made of white original polyester fibers containing fluorescent whitening agents have been proposed. (Patent Documents 7 to 9). However, in this method, the object is mainly white goods and needs to be used in combination with the post-processing method, and there still remains a problem in the washing durability. Also known is an antifouling polyester fiber comprising a polyester obtained by copolymerizing the above-mentioned one-end-capped polyoxyethylene glycol at the end of the polyester main chain and containing a specific fluorescent whitening agent. It is difficult to obtain sufficient antifouling properties while maintaining the physical properties (Patent Document 10).

Japanese Patent Publication No. 47-2512 Japanese Patent Publication No.51-2559 JP-A-62-90312 JP-A-63-35824 JP 63-35825 A JP-A-63-50524 JP-A-62-90378 JP-A-5-311539 JP 2004-270058 A JP 63-12717 A “Polymer” August 1978, pages 904-912

  The present invention has been made in view of the above background, and its purpose is to have practical fiber properties, greatly improve antifouling properties and washing durability, and particularly improve darkness due to washing. Another object of the present invention is to provide a copolyester fiber and a fiber product using the same.

  As a result of studies conducted by the present inventors to achieve the above object, a modified polyester fiber produced by adding a specific amount of a fluorescent whitening agent to a copolyester fiber in which a polyether component is copolymerized in a side chain. However, not only darkening due to washing does not occur, but also the whiteness of the fabric itself increases by repeated washing, especially when drying after washing is done by sun drying, the oil stains remaining on the fabric disappear and remarkably It has been found that an increased whitening effect can be obtained.

（式中、Ｒ_１は炭化水素基、Ｒ_１’はアルキレン基、ｎ１は重合度を示す正の整数である）

（式中、Ｒ_２は炭化水素基、Ｒ_２’はアルキレン基、ｎ２は重合度を示す正の整数である）
４．ポリエーテル成分の共重合量が共重合ポリエステルに対して０．５〜１０重量％である、１〜３のいずれかに記載の共重合ポリエステル繊維。
５．蛍光増白剤がスチルベン系蛍光増白剤である１〜４のいずれかに記載の共重合ポリエステル繊維。
６．スチルベン系蛍光増白剤が４，４’−ビス（ベンゾオキサゾリル）−スチルベンである５に記載の共重合ポリエステル繊維。
７．１〜６のいずれかに記載の共重合ポリエステル繊維を少なくとも一部に用いた繊維製品。 That is, the present invention is as follows.
1. In the polyester fiber, the fiber is made of a copolyester having a polyether component copolymerized in a side chain, and contains 0.001 to 2% by weight of a fluorescent whitening agent based on the weight of the fiber. Copolyester fiber characterized by that.
2. 2. The copolyester fiber according to 1, wherein the polyether component is a polyoxyethylene polyether.
3. The copolyester fiber according to 1 or 2, wherein the copolyester is a polyester obtained by copolymerizing a diol compound represented by the following general formula (1) and / or an epoxy compound represented by the following general formula (2).

(In the formula, R ₁ is a hydrocarbon group, R ₁ ′ is an alkylene group, and n 1 is a positive integer indicating the degree of polymerization)

(Wherein R ₂ is a hydrocarbon group, R ₂ ′ is an alkylene group, and n2 is a positive integer indicating the degree of polymerization)
4). Copolymer polyester fiber in any one of 1-3 whose copolymerization amount of a polyether component is 0.5 to 10 weight% with respect to copolymer polyester.
5. The copolyester fiber according to any one of 1 to 4, wherein the optical brightener is a stilbene fluorescent brightener.
6). 6. The copolyester fiber according to 5, wherein the stilbene fluorescent whitening agent is 4,4′-bis (benzoxazolyl) -stilbene.
A fiber product using at least a part of the copolyester fiber according to any one of 7.1 to 6.

  The copolyester fiber of the present invention has practical fiber properties, greatly improves the antifouling property and its washing durability, and is particularly improved in darkening due to washing. For this reason, the above fibers are particularly effective in the field of linen supply such as rental uniforms, and the antifouling property is maintained regardless of how many times the washing is repeated, and the darkening due to washing does not occur, or the whitening is rather increased. It also has the characteristics. Furthermore, since the copolyester fiber of the present invention contains a fluorescent brightening agent, it exhibits excellent whiteness and good light fastness without fluorescent staining.

  In the present invention, the polyester constituting the copolymerized polyester fiber has terephthalic acid as the main bifunctional carboxylic acid component, and at least one alkylene glycol selected from at least one glycol, ethylene glycol, trimethylene glycol, and tetramethylene glycol. The main target is polyesters having a glycol component.

  Further, a polyester in which a part of the terephthalic acid component is replaced with another bifunctional carboxylic acid component may be used, and / or a part of the glycol component is replaced with the above-mentioned glycol or other diol component other than the main component. Polyester may be used.

  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, and adipic acid. And aromatic, aliphatic and alicyclic bifunctional carboxylic acids such as sebacic acid and 1,4-cyclohexanedicarboxylic acid.

  Examples of the diol compound other than the glycol include aliphatic, alicyclic, and aromatic diol compounds such as cyclohexane-1,4-dimethanol, neopentyl glycol, bisphenol A, and bisphenol S.

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

  Such polyester is synthesized by any method. For example, for polyethylene terephthalate, terephthalic acid and ethylene glycol are usually esterified directly, terephthalic acid lower alkyl ester such as dimethyl terephthalate is transesterified with ethylene glycol, or terephthalic acid and ethylene oxide. In the first stage to produce a glycol ester of terephthalic acid and / or its low polymer, and the reaction product in the first stage is heated under reduced pressure until the desired degree of polymerization is reached. It is produced by a second stage reaction that causes a condensation reaction.

  The polyester constituting the copolymerized polyester fiber of the present invention needs to be a copolymerized polyester in which a polyether component is copolymerized. The polyether component is preferably a polyoxyalkylene component, for example, a copolymer obtained by copolymerizing the base polyester with a diol compound represented by the following general formula (1) and / or an epoxy compound represented by the following general formula (2). Polyester can be given as a preferred specific example.

  In the present invention, the base polyester is preferably copolymerized with a diol compound represented by the following general formula (1) and / or an epoxy compound represented by the following general formula (2).

In these formulas, R ₁ and R ₂ represent a hydrocarbon group, preferably an alkyl group, a cycloalkyl group, an aryl group or an alkylaryl group. R ₁ ′ and R ₂ ′ are alkylene groups, preferably alkylene groups having 2 to 4 carbon atoms. Specific examples include an ethylene group, a propylene group, and a tetramethylene group. Further, it may be a random copolymer or block copolymer having two or more kinds of mixtures, for example, an ethylene group and a propylene group, or an ethylene group and a tetramethylene group. n1 and n2 are positive integers indicating the degree of polymerization, and are preferably in the range of 30 to 140. If the degree of polymerization is less than 30, the sufficient hygroscopicity, moisture permeability and the refreshing feeling and cooling feeling of natural fibers such as cotton and hemp are not exhibited, and the object of the present invention is not achieved. Further, when the degree of polymerization exceeds 140, copolymerization becomes difficult anymore, and sufficient hygroscopicity, moisture permeability, refreshing feeling and cooling feeling are not exhibited. In particular, the range of 40 to 100 is preferable because particularly excellent hygroscopicity and moisture permeability are exhibited and a refreshing feeling and a cool feeling are particularly remarkably exhibited. R ₁ and R ₂ , R ₁ ′ and R ₂ ′, n1 and n2 may be the same or different from each other.

  Preferable specific examples of such compounds include polyoxyethylene glycol methyl 1,2-dihydroxypropyl ether, polyoxyethylene glycol phenyl 1,2-dihydroxypropyl ether, polyoxyethylene glycol as the diol compound represented by the above formula (1). Isopropyl 1,2-dihydroxypropyl ether, polyoxyethylene glycol n-butyl 1,2-dihydroxypropyl ether, polyoxyethylene glycol octylphenyl 1,2-dihydroxypropyl ether, polyoxyethylene glycol nonylphenyl 1,2-dihydroxypropyl Ether, polyoxyethylene glycol cetyl 1,2-dihydroxypropyl ether, polyoxypropylene glycol methyl 1,2-dihydro Cypropyl ether, polyoxypropylene glycol phenyl 1,2-dihydroxypropyl ether, polyoxypropylene glycol n-butyl 1,2-dihydroxypropyl ether, polyoxypropylene glycol octylphenyl 1,2-dihydroxypropyl ether, polyoxypropylene glycol Nonylferni 1,2-dihydroxypropyl ether, polyoxytetramethylene glycol methyl 1,2-dihydroxypropyl ether, polyoxyethyl glycol / polyoxypropylene glycol copolymer methyl 1,2-dihydroxypropyl ether, etc. Of these, polyoxyethylene glycol derivatives are particularly preferred. The above diol compounds may be used alone or in combination of two or more.

  In addition, preferred specific examples of the epoxy compound represented by the above formula (2) include polyoxyethylene glycol methyl glycidyl ether, polyoxyethylene glycol phenyl glycidyl ether, polyoxyethylene glycol isopropyl glycidyl ether, polyoxyethylene glycol n- Butyl glycidyl ether, polyoxyethylene glycol octylphenyl glycidyl ether, polyoxyethylene glycol nonylphenyl glycidyl ether, polyoxyethylene glycol cetyl glycidyl ether, polyoxypropylene glycol methyl glycidyl ether, polyoxyethylene glycol phenyl glycidyl ether, polyoxyethylene glycol n-Butyl glycidyl ether, polyoxyethylene glycol Lumpur octylphenyl glycidyl ether, polyoxyethylene glycol nonylphenyl glycidyl ether, polyoxy tetramethylene glycol methyl glycidyl ether, may be mentioned methyl glycidyl ether of polyoxyethylene glycol / polyoxypropylene glycol copolymer. Of these, polyoxyethylene glycol derivatives are particularly preferred. The said epoxy compound may be used individually by 1 type, and may use 2 or more types together.

  In order to copolymerize the diol compound and / or epoxy compound with the base polyester, any stage until the synthesis of the polyester described above is completed, for example, before the start of the first stage reaction, during the reaction, after the completion of the reaction, It may be added at any stage such as during the second stage reaction, and the polycondensation reaction may be completed after the addition. In this case, if the amount used is too small, the final molded polyester product will have insufficient hygroscopicity, coolness, and coolness. The improvement in performance is not seen, but the physical properties of the molded product finally obtained, for example, the strength and elongation of the fiber are deteriorated, as well as the heat resistance and light resistance are lowered. In the range of 10 to 40% by weight, and preferably in the range of 15 to 30% by weight.

  In the production of the copolyester used in the present invention, the addition of a conventionally known hindered phenolic antioxidant or hindered amine light stabilizer as a stabilizer is caused by thermal degradation and oxidative degradation during use of the copolyester fiber. It is preferable because it not only has an effect of suppressing photodegradation but also an effect of suppressing a decrease in intrinsic viscosity of the polymer during melt spinning.

  In the present invention, the polyester constituting the copolymerized polyester fiber is a copolymerized polyester in which the polyether component is copolymerized in the side chain, and, as will be described later, It is important that a specific amount of optical brightener is contained. As a result of repeated studies by the present inventor, the above-described modified polyester fiber not only does not cause darkening due to washing, but rather increases the whiteness of the fabric by repeated washing, particularly drying after washing. When it was performed by drying, the oil stains remaining on the fabric disappeared, and it was found that a markedly increased whitening effect was obtained.

  Although this mechanism of action is not yet clarified, from the results of previous studies, this phenomenon is a phenomenon that occurs specifically in the above fibers, and is a polyether component copolymerized in the side chain, particularly a polyoxyethylene-based polymer. It is presumed that some kind of light-sensitive action acts between the ether and the optical brightener, so that oil stains are easily decomposed or dropped off.

  Examples of the optical brightener used in the present invention include pyrene series, oxazole series, coumarin series, thiazole series, imidazole series, imidazolone series, pyrazole series, benzidine series, diaminocarbazole series, diaminostilbene disulfonic acid series and the like. Of these, oxazole-based and coumarin-based fluorescent brighteners having excellent heat resistance at the polymerization temperature and melt spinning temperature of polyester are preferably used.

  Specific examples of such preferred optical brighteners include, for example, 4,4′-bis (benzoxazolyl) -stilbene, 4,4-bis (5-methylbenzoxazolyl) -stilbene, 4- (benzoxa Zolyl) -4 '-(5-methylbenzoxazolyl) -stilbene, 4,4'-bis (5,6-dimethylbenzoxazolyl) -stilbene, 4,4'-bis (5-phenylbenzo) Oxazolyl) -stilbene, 4,4′-bis (5-benzylbenzoxazolyl) -stilbene, 4,4′-bis (5-chlorobenzoxazolyl) -stilbene, 4,4′-bis Benzoxazolyl stilbene derivatives such as (5-bromobenzoxazolyl) -stilbene, 4,4′-bis (5-methoxybenzoxazolyl) -stilbene, 2,5-dibenzoo Xazolyl-thiophene, 2,5-di (methoxybenzoxazolyl) -thiophene, 2,5-di (methylbenzoxazolyl) -thiophene, 2,5-di (tobutylbenzoxazolyl) -thiophene, Benzoxazolylthiophene derivatives such as 2-benzoxazolyl-5-t-butylbenzoxazolyl-thiophene, 3-phenyl-7- (pyrazol-1-yl) coumarin, 3-phenyl-7- ( And coumarine derivatives such as 3-methyl-pyrazol-1-yl) -coumarin, 3-tolyl-7- (3-methyl-pyrazol-yl) -coumarin, and the like, among which benzoxazolyl Most preferred are stilbene derivatives.

  The content of these optical brighteners is in the range of 0.001 to 2% by weight based on the weight of the copolyester fiber. If the content is less than 0.001% by weight, the antifouling performance is insufficient, and if it exceeds 2% by weight, the fiber finally obtained is colored yellow and cannot be practically used. As said content, the range of 0.005-0.5 weight% is preferable, and the range of 0.01-0.1 weight% is more preferable.

  The fluorescent brightening agent may be added in any process from the polymerization step of the copolymerized polyester to spinning, and any method for producing the copolymerized polyester fiber by the polymerization addition method, masterbatch method, liquid method, etc. Applies to Among these, it is preferable to add after the completion of polymerization from the viewpoint of handling such as equipment contamination and control. Examples of the method to be added after the completion of the polymerization include a master batch method and a liquid method, but the master batch method is preferable from the viewpoint of stability during melt spinning and handling of colorants.

  Furthermore, when obtaining fibers by the masterbatch method, the timing of adding the optical brightener is measured and mixed at the raw material pellet stage, melt-spun, and separately melted polymer is measured and mixed and spun. However, you can use either method.

  As a method for producing the copolyester fiber, it is not necessary to adopt a special method, and a normal polyester fiber melt spinning method and a production method by the masterbatch method described above are arbitrarily applied. For example, it is manufactured by a method in which a copolymerized polyester and a master chip or liquid are melt-mixed, discharged from a spinneret, wound, and then subjected to stretching or heat treatment as necessary.

The copolyester fiber thus obtained may be a long fiber or a short fiber, and the fineness may be arbitrary. The cross-sectional shape of the fiber may be circular or irregular, and may be a hollow fiber or a solid fiber.
The copolyester fiber may contain optional additives such as an anti-coloring agent, a heat-resistant agent, a flame retardant, a matting agent, and inorganic fine particles as necessary.

  Furthermore, the copolymerized polyester fiber of the present invention is used for blending, interweaving and the like with natural fibers such as cotton and wool, regenerated fibers such as rayon and acetate, and synthetic fibers other than the polyester of the present invention, as necessary.

  The copolymer polyester fiber according to the present invention described above can be formed into a fiber product using at least a part of the copolymer polyester fiber in the form of yarn, woven or knitted fabric, nonwoven fabric or the like. Specific examples of such textile products include the following.

(1) Clothing use Shirts, blouses, pants, blousons, coats, Japanese clothing, etc. for fashion use, underwear, bras, girdles, body fur, camisole, shorts, pantyhose, stockings, socks, high socks, shorts for use as inner legs Game shirts and pants for sports use such as socks (tennis, basketball, table tennis, volleyball, track, golf, soccer, rugby, etc.), sweat suits, windbreakers, athletic wear, training wear, shorts, swimwear, swimming pool Side wear, underwear, tights, spats, leotards, leg clothing, wet suits, dry suits, white coats such as food white coats, uniforms such as ladies' blouses, nightwear Way, school clothes, hats, shawls and other clothing accessories, lining, cups, pads and other clothing materials, sports shoes, etc.

(2) Interior / bedding applications Curtains (draping curtains, lace curtains, shower curtains, roll curtains, blinds, etc.), carpets, tablecloths, chairs, partitions, wallpaper, bedding (bedclothes, mattresses, futon bedding, futons) Padding, blankets, blankets, towels, sheets, etc.), slippers, mats, etc.

(3) Automotive interior materials applications Car seats, car mats, ceiling materials, trims, etc.

(4) Industrial materials use Tents (for leisure, events, etc.)

  EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples and comparative examples, but the present invention is not limited by these. In addition, the part and% in an Example and a comparative example show a weight part and weight%, respectively.

(1) Intrinsic viscosity Measured with an orthochlorophenol solution at 35 ° C.

(2) Antifouling property and whiteness A plain fabric sample of 10 cm × 13 cm was loaded into a treatment pot containing a washing recontamination liquid having the following composition so that the bath ratio was 1: 260 (100% cotton scouring cloth) The mixture was adjusted at 50 ° C. and stirred for 60 minutes.
Artificial oil stain (motor oil 99.335% + heavy oil 0.634% + carbon black 0.031%): 1%
-Sodium alkylbenzene sulfonate: 0.02%
・ Sodium sulfate: 0.03%
・ Sodium tripolyphosphate: 0.02%

  After lightly washing with water, the sample was sandwiched between filter papers to remove excess contaminants. Next, the contaminated sample was washed in a household washing machine using the standard amount of synthetic detergent for washing, and the washing operation specified in JIS L 0217 Attached Table 1 No. 103 was defined as one cycle (one time). Repeated. The washing temperature was 40 ° C., and drying was performed in each of indoor natural drying and sun drying.

Furthermore, using a Minolta color difference meter CR-200 (manufactured by Minolta Camera Sales Co., Ltd.), L ^* , a ^* , b ^* of the CIE color system of the sample was measured by a conventional method, and antifouling property (ΔE *) And whiteness were determined.

［数２］
白度＝Ｌ^＊−ｂ^＊
上記式中、ΔＥ^＊は防汚性を示し、この値が小さいほど防汚性に優れることを示す。Ｌ₁、ａ₁、ｂ₁は汚染処理前の試料のＬ^＊、ａ^＊、ｂ^＊値を、Ｌ₂、ａ₂、ｂ₂は洗濯後の試料のＬ^＊、ａ^＊、ｂ^＊値をそれぞれ示す。

[Equation 2]
Whiteness = L ^* −b ^*
In the above formula, ΔE ^* indicates antifouling property, and the smaller the value, the better the antifouling property. L ₁ , a ₁ , b ₁ are the L ^* , a ^* , b ^* values of the sample before contamination treatment, and L ₂ , a ₂ , b ₂ are the L ^* , a ^* , b ^* values of the sample after washing. Each is shown.

[Examples 1 to 5 and Comparative Example 1]
(Manufacture of optical brightener-containing master chip)
After dry blending 3.5 parts of 4,4′-bis (benzoxazolyl) -stilbene powder and 96.5 parts of a dry chip of polyethylene terephthalate having an intrinsic viscosity of 0.640 for 5 minutes in a Nauta mixer, 2 Using an axial extruder, it was melt mixed at a temperature of 275 ° C. The melt-mixed polymer was extruded in a strand form into a water bath, and after cooling, this was cut to obtain a master chip having a fluorescent whitening agent content of 3.5%.

(Manufacture of copolyester chips)
100 parts of dimethyl terephthalate, 60 parts of ethylene glycol, 0.06 part of calcium acetate monohydrate (0.066 mol% with respect to dimethyl terephthalate) and 0.009 part of cobalt acetate tetrahydrate as a color adjuster (terephthalic acid) The transesterification can be carried out while distilling out the methanol produced by heating from 140 ° C to 220 ° C over 4 hours in a nitrogen gas atmosphere. went. After completion of the transesterification reaction, 0.058 parts of trimethyl phosphate (0.080 mol% with respect to dimethyl terephthalate) was added as a stabilizer. Then, 10 minutes later, 0.04 part of antimony trioxide (0.027 mol% with respect to dimethyl terephthalate) was added, and the temperature was raised to 240 ° C. while expelling excess ethylene glycol.

  After adding 4.12 parts of polyoxyethylene glycol methyl 1,2-dihydroxypropyl ether having an average molecular weight of 3000 (m = 66) (4% with respect to the copolymerized polyester) to the polymerization can, 760 Torr over 1 hour. The pressure was reduced from 1 to 1 Torr, and the temperature was raised from 240 ° C. to 280 ° C. over 1 hour 30 minutes. At the time of polymerization for 2 hours at a polymerization temperature of 280 ° C. under a reduced pressure of 1 Torr or less, 0.8 part of Irganox 1010 (manufactured by Ciba Specialty Chemicals) was added in vacuum as an antioxidant, and then polymerized for another 30 minutes. The obtained copolyester was chipped according to a conventional method. The intrinsic viscosity of this copolymer polyester chip was 0.685.

(Manufacture of fibers)
After drying the above-mentioned optical brightener-containing master chip and copolymer polyester chip by a conventional method, the content of the optical brightener in the mixed chip (that is, the content in the fiber) becomes the content shown in Table 1. Thus, melt spinning was performed at 285 ° C. using a spinneret having 24 circular spinning holes having a hole diameter of 0.3 mm. Subsequently, the obtained undrawn yarn was drawn and heat-treated using a heating roller at 84 ° C. and a plate heater at 180 ° C. at a draw ratio at which the elongation of the drawn yarn finally obtained was 30%, and was 55 decitex / 24. A filament drawn yarn was obtained. A plain woven fabric was woven using the obtained drawn yarn, and refined and heat-treated by a conventional method. Table 1 shows the results of evaluating the properties of the obtained plain fabric. The plain woven fabric had practical strength, maintained the same strength even after washing 25 times, and was excellent in practicality.

[Examples 6 to 8 and Comparative Examples 2 to 4]
Similar to Examples 1-5 and Comparative Example 1 except that the copolymerization amount of the copolymerized polyether used in Examples 1-5 and Comparative Example 1 and the content of the optical brightener were changed as shown in Table 1. Went to. The results are shown in Table 1.

[Example 9]
Instead of using the optical brightener 4,4′-bis (benzoxazolyl) -stilbene added by the masterbatch method in Example 2, instead, the coumarin-based optical brightener Hackol represented by the following general formula The same procedure as in Example 2 was conducted except that 0.036 parts of PSR (Hackol Chemical Co., Ltd.) (0.035% based on the copolyester) was added subsequently to antimony trioxide after completion of the transesterification reaction. The results are shown in Table 1.

[Comparative Example 5]
The same procedure as in Example 2 was performed except that polyoxyethylene glycol methyl 1,2-dihydroxypropyl ether, which is a copolymerized polyether, was not used. The results are shown in Table 1.

  The copolyester fiber of the present invention has practically improved fiber properties, and has significantly improved antifouling properties and washing durability as compared with the prior art, and particularly the darkness due to washing is greatly improved. Therefore, the fiber is particularly useful in the field of linen supply such as rental uniforms. Specifically, for example, when clothes such as underwear, white coats such as food white coats, uniforms such as blouse for ladies, linen materials such as table cloths, etc., the characteristics are exhibited, and washing is repeated many times. In addition, the antifouling property is maintained, and blackening due to washing does not occur, or rather, whitening occurs. Moreover, since the copolyester fiber of the present invention contains a fluorescent brightening agent, it exhibits excellent whiteness and good light fastness without being subjected to fluorescent dyeing.

Claims (7)

  In the polyester fiber, the fiber is made of a copolyester having a polyether component copolymerized in a side chain, and contains 0.001 to 2% by weight of a fluorescent whitening agent based on the weight of the fiber. Copolyester fiber characterized by that.   The copolymer polyester fiber according to claim 1, wherein the polyether component is a polyoxyethylene-based polyether. The copolyester fiber according to claim 1 or 2, wherein the copolyester is a polyester obtained by copolymerizing a diol compound represented by the following general formula (1) and / or an epoxy compound represented by the following general formula (2).

(In the formula, R ₁ is a hydrocarbon group, R ₁ ′ is an alkylene group, and n 1 is a positive integer indicating the degree of polymerization)

(Wherein R ₂ is a hydrocarbon group, R ₂ ′ is an alkylene group, and n2 is a positive integer indicating the degree of polymerization)   The copolymerized polyester fiber according to any one of claims 1 to 3, wherein a copolymerization amount of the polyether component is 0.5 to 10% by weight based on the copolymerized polyester.   The copolyester fiber according to any one of claims 1 to 4, wherein the fluorescent whitening agent is a stilbene fluorescent whitening agent.   6. The copolyester fiber according to claim 5, wherein the stilbene fluorescent whitening agent is 4,4'-bis (benzoxazolyl) -stilbene.   A fiber product using at least a part of the copolymerized polyester fiber according to claim 1.