JPH043449B2 - - Google Patents

Description

[Detailed description of the invention]

(a) Industrial Application Field The present invention relates to modified polyester fibers, and more particularly to modified polyester fibers with improved restaining properties during washing. (b) Prior Art Polyester fibers have traditionally been used in many fields because they have many excellent properties such as good dimensional stability, strength, and resistance to wrinkles. However, even with polyester fibers having such excellent properties, oil-based stains tend to adhere to polyester fibers more easily than hydrophilic fibers such as cotton and are difficult to remove due to the hydrophobic nature of polyester, and stains tend to re-adhere during washing. There are problems such as easy. This restaining property has always been a problem ever since polyester fibers were put into practical use, and many methods have been proposed to solve this problem. For example, a method of immersing a polyester molded product in a melt or dispersion of a copolymer of polyethylene glycol and a polyester resin (see Japanese Patent Publication No. 47-2512), and a method of dipping a polyester molded product in a melt or dispersion of a copolymer of polyethylene glycol and a polyester resin, A method of applying steam treatment after spraying or spraying (see Japanese Patent Publication No. 51-2559) or a method of low-temperature plasma treatment of a gas containing oxygen (“Polymer”)
August 1978 issue, pages 904-912), etc. However, all of these methods have been proposed as finishing treatments for polyester fiber products, and they have problems in terms of processing, such as complicated operations, the need for special equipment, and poor processing reproducibility. Furthermore, there is a problem that the initial effect gradually disappears as the number of washings increases for clothes that are washed frequently, such as underwear and white coats. There has been a strong desire for the emergence of polyester fibers (free from darkening caused by oxidation). (c) Purpose of the Invention As a result of intensive studies aimed at providing polyester fibers that are particularly resistant to darkening caused by washing and have excellent stain resistance, the inventors of the present invention discovered that polyoxyalkylene glycol with one end-capped polyoxyalkylene glycol was added to the end of the main chain. Perhaps because the polyoxyalkylene glycol copolymerized at the ends of the main chain acts specifically, polyesters copolymerized with polyoxyalkylene glycol that are not blocked at both ends are copolymerized into the polyester main chain, and polyesters that are copolymerized at both ends Compared to polyesters that have a blockaded polyoxyalkylene glycol or a polyoxyalkylene glycol that is insoluble in the polyester blended into a polyester matrix.
I first filed an application after learning that when made into fiber, it exhibits significantly improved stain resistance and washing durability. As a result of continuing intensive studies on ways to further improve stain resistance, we discovered that by mixing a specific stilbene-based optical brightener with a polyester copolymerized with the above-mentioned one-end-capped polyoxyalkylene glycol at the end of the main chain, we found that both of them could be improved. It has been discovered that these act synergistically to significantly improve stain resistance and washing durability. The present invention was completed as a result of further studies based on this knowledge. (d) Structure of the invention The present invention is based on the following general formula () R ¹ O (R ² O−) _o ... (1) [wherein, R ¹ is a hydrocarbon group, R ² is an alkylene group,
n is a positive integer indicating the degree of polymerization. ] The following general formula () is added to a copolymerized polyester in which at least some of the ends thereof are copolymerized with a polyoxyalkylene glycol component with one end blocked, represented by 0.001 to 2.0% by weight based on the copolymerized polyester. [In the formula, R ³ and R ⁴ represent a hydrogen atom, an alkyl group, an alkoxy group, an aryl group, or a halogen atom, and a and b are 1 or 2. ] This is a modified polyester fiber made of polyester containing a stilbene-based optical brightener. The polyester in the present invention has terephthalic acid as its main acid component and at least one type of alkylene glycol having 2 to 6 carbon atoms, namely ethylene glycol, trimethylene glycol, tetramethylene glycol, pentamethylene glycol and hexamethylene glycol. Targets polyesters whose main glycol component is glycol. In such a polyester, part of its acid component terephthalic acid may be replaced by another difunctional carboxylic acid. Such other carboxylic acids include, for example, isophthalic acid, 5-sodium sulfoisophthalic acid, naphthalene dicarboxylic acid, diphenyl dicarboxylic acid, diphenoxyethane dicarboxylic acid, β-oxyethoxybenzoic acid, and p-oxybenzoic acid. difunctional aromatic carboxylic acid,
Examples include difunctional fatty acid carboxylic acids such as sebacic acid, adipic acid, and oxalic acid, and difunctional alicyclic carboxylic acids such as 1,4-cyclohexanedicarboxylic acid. Further, a part of the glycol component of the polyester may be replaced with another glycol component, and such glycols include the above-mentioned glycols other than the main component and other diol compounds, such as cyclohexane-1,4-dimethanol, neopentyl glycol, Examples include aliphatic, alicyclic, and aromatic diol compounds such as bisphenol A and bisphenol S, and polyoxyalkylene glycols with both ends unblocked. Such polyesters can be produced by any method. For example, regarding polyethylene terephthalate, terephthalic acid and ethylene glycol may be directly esterified, a lower alkyl ester of terephthalic acid such as dimethyl terephthalate may be transesterified with ethylene glycol, or terephthalic acid and ethylene oxide may be transesterified. The first step is to react the glycol ester of terephthalic acid and/or its low polymer, and then the product is heated under reduced pressure to undergo a polycondensation reaction until the desired degree of polymerization is achieved. It is easily produced by a two-step reaction. In the present invention, polyoxyalkylene glycol with one end blocked and represented by the following general formula () R ¹ O (R ² O-) _o ... () is co-terminated at the end of at least a part of the main chain of the above-mentioned polyester. It is necessary that it be polymerized. In this formula, R ¹ represents a hydrocarbon group, preferably an alkyl group, a cycloalkyl group, an aryl group or an alkylaryl group. R ² is an alkylene group, preferably an alkylene group having 2 to 4 carbon atoms. Specific examples include ethylene group, propylene group, and tetramethylene group. It may also be a mixture of two or more types, for example a copolymer having an ethylene group and a propylene group. n is a positive integer indicating the degree of polymerization, and is preferably in the range of 30 to 140. Preferred specific examples of such one-end-blocked polyoxyalkylene glycol include polyoxyethylene glycol monomethyl ether, polyoxyethylene glycol monophenyl ether, polyoxyethylene glycol monooctylphenyl ether, and polyoxyethylene glycol monononyl phenyl ether. , polyoxyethylene glycol monocetyl ether, polyoxypropylene glycol monoethyl ether, polyoxypropylene glycol monophenyl ether, polyoxypropylene glycol monononyl phenyl ether, polyoxypropylene glycol monooctyl phenyl ether, polyoxytetramethylene glycol Examples include monomethyl ether, monomethyl ether of polyoxyethylene glycol/polyoxypropylene glycol copolymer, and ester-forming derivatives thereof. In order to copolymerize the above single end-capped polyoxyalkylene glycol at the end of a polyester chain,
At any stage before the synthesis of the polyester described above is completed, for example, before the start of the first stage reaction, during the reaction,
After the reaction is completed, it may be added at any stage such as the second stage reaction, and the production reaction may be completed after the addition. At this time, if the amount used is too small, the stain-proofing performance and washing durability of the final polyester fiber obtained will be insufficient, and on the other hand, if it is too large, the degree of polymerization of the polyester will be too low during the polycondensation reaction process. Since the level reaches a plateau and the yarn properties such as strength of the final polyester fiber deteriorate, it is recommended that the amount be in the range of 0.01 to 4.0 mol% based on the bifunctional carboxylic acid component that makes up the polyester. Preferably, the range of 0.1 to 3.0 mol% is particularly preferable. The polyester constituting the modified polyester fiber of the present invention is copolymerized with the above-mentioned end-capped polyoxyalkylene glycol and contains a specific amount of a specific stilbene-based optical brightener. Such a stilbene-based optical brightener is represented by the following general formula (). In the above formula, R ³ and R ⁴ are hydrogen atoms, alkyl groups,
It is an alkoxy group, an aryl group, or a halogen atom, and R ³ and R ⁴ may be the same or different. a and b are each 1 or 2. Particularly preferred examples of such stilbene-based optical brighteners include 4,4'-bis(benzoxazolyl)-stilbene, 4,4'-bis(5-methylbenzoxazolyl)-stilbene, 4-( benzoxazolyl)-4'-(5-methylbenzoxazolyl)-stilbene, 4,4'-bis(5,6-dimethylbenzoxazolyl)-stilbene, 4,
4'-bis(5-phenylbenzoxazolyl)-
Stilbene, 4,4'-bis(5-benzylbenzoxazolyl)-stilbene, 4,4'-bis(5
-chlorobenzoxazolyl)-stilbene, 4,
Examples include 4'-bis(5-bromobenzoxazolyl)-stilbene and 4,4'-bis(5-methoxybenzoxazolyl)-stilbene. These may be used alone or in combination of two or more. In order to incorporate the above-mentioned stilbene-based optical brightener into the modified polyester fiber of the present invention, it is possible to incorporate it at any stage before the production of the modified polyester fiber is completed, for example, before the start of the polyester synthesis reaction, during the reaction, or after the completion of the reaction. It may be added later, and it is particularly preferable to add it between the end of the polyester synthesis reaction and just before spinning, from the viewpoint of preventing thermal deterioration of the fluorescent agent. If the amount used is less than 0.001% by weight based on the polyester, the use of the stilbene-based optical brightener will not be sufficient to improve the antifouling performance of polyester fibers and the washing durability; If the amount exceeds 2% by weight, no improvement in antifouling performance will be observed, and on the contrary, spinning performance such as spinnability and drawability will deteriorate. Therefore, the amount used should be in the range of 0.001 to 2% by weight, based on the polyester, preferably in the range of 0.01 to 1% by weight. Fluorescent brighteners for raw materials other than the stilbene fluorescent brighteners represented by the above general formula (), such as triazinylstilbene compounds represented by the following formula: Although a fluorescent whitening effect was observed when using this method, no effect on improving stain resistance was observed. Although the reason for this is not clear, it is presumed that some kind of interaction occurs between the polyoxyalkylene glycol bonded to the end of the polyester chain and the benzoxazolylstilbene compound. To make the modified polyester obtained in this way into fibers, there is no need to employ any special method, and any ordinary melt-spinning method for polyester fibers may be employed. The fibers spun here may be solid fibers having no hollow portions or hollow fibers having hollow portions. Further, the outer shape and the shape of the hollow portion in the cross section of the fiber to be spun may be circular or irregular. (e) Effects of the Invention The polyester fiber of the present invention exhibits its characteristics particularly when used in frequently washed clothing such as underwear and white coats, and retains its stain-repellent properties no matter how many times it is washed. , no darkening caused by washing. Therefore, the stain-resistant polyester fiber of the present invention is particularly useful in the linen supply field. Further, as mentioned above, the stain-resistant polyester fiber of the present invention contains a stilbene-based fluorescent brightener, so it exhibits excellent whiteness even without fluorescent dyeing and has good light fastness. . The polyester fiber of the present invention may contain optional additives, such as catalysts, color inhibitors, heat resistant agents,
Flame retardants, antioxidants, matting agents, colorants, inorganic fine particles, etc. may be included. (f) Examples The following examples will be further explained. Parts and % in Examples indicate parts by weight and % by weight, respectively.
The intrinsic viscosity [η] of the polymer was determined from the value measured in an orthochlorophenol solution at 35°C, and the softening point (SP) was measured by the penetration method. The hue of the polymer was indicated by the L value and b value determined by a Hunter color difference meter. The larger the L value, the better the whiteness, and the higher the b value on the + side, the stronger the yellowness. Further, whether or not the polyoxyalkylene glycol component was copolymerized was determined by rapidly cooling the molten polymer to prepare a plate with a thickness of 2 mm, and checking the transparency of the plate. The greater the opacity, the less copolymerized the polyoxyalkylene glycol component is. <Production of master chip containing optical brightener> 3.5 parts of 4,4'-bis(benzoxazolyl)-stilbene powder, intrinsic viscosity 0.640, softening point 263°C
Dry chips of polyethylene terephthalate 96.5
The mixture was dry blended in a Nauta mixer for 5 minutes, then heated to 275°C using a twin-screw extruder.
The mixture was melt-mixed at a temperature of . The polymer was extruded into hestrands in a water bath and cool cut into chips (optical brightener content 3.5%). Examples 1 to 4 and Comparative Example 1 100 parts of dimethyl terephthalate, 60 parts of ethylene glycol, 0.06 part of calcium acetate monohydrate (0.066 mol% relative to dimethyl terephthalate), and 0.009 part of cobalt acetate tetrahydrate as a coloring agent. (0.007 mol% based on dimethyl terephthalate) was charged into a transesterification tank, and the transesterification was carried out for 4 hours under a nitrogen gas atmosphere.
The transesterification reaction was carried out while raising the temperature from 140°C to 220°C and distilling the generated methanol out of the system. After the transesterification reaction was completed, 0.058 part of trimethyl phosphate (0.080 mol % based on dimethyl terephthalate) was added as a stabilizer. Then, 10 minutes later, 0.04 part of antimony trioxide (0.027 mol % based on dimethyl terephthalate) was added, and at the same time, the temperature was raised to 240°C while expelling excess ethylene glycol, and the mixture was transferred to a polymerization vessel. After adding 4 parts of polyoxyethylene glycol monophenyl ether with an average molecular weight of 2000 (n=43) to the polymerization reactor, the temperature was increased from 760 mmHg to 1
Reduce the pressure to mmHg and at the same time raise the temperature to 240°C over 1 hour and 30 minutes.
The temperature was raised from 280℃ to 280℃. Under reduced pressure of 1 mmHg or less,
After further polymerization at a polymerization temperature of 280° C. for 2 hours, 0.4 part of Irganox 1010 (manufactured by Ciba Geigy) as an antioxidant was added under vacuum, and then polymerization was continued for another 30 minutes. Plates made from the resulting polymer had a transparent appearance, and the polyoxyethylene glycol monophenyl ether was copolymerized. Table 1 also shows the intrinsic viscosity [η], softening point, polymer hue L value, and b value of the obtained polymer. The polymer was made into chips according to a conventional method. After drying this chip and the master chip containing 3.5% 4,4'-bis(benzooxazolyl)-stilbene by a conventional method, the content of the fluorescent agent in the mixed chip was adjusted to the content listed in Table 1. and melt-spun at 285°C using a spinneret with 24 circular spinning holes with a hole diameter of 0.3 mm. Next, the obtained undrawn yarn was heat-treated by drawing using a heating roller at 84°C and a plate heater at 180°C at a drawing ratio such that the elongation of the drawn yarn finally obtained was 30% to obtain a 50 denier/24 A drawn filament yarn was obtained. A plain woven fabric was woven using the obtained polyester filament yarn (50 denier/24 filaments), and after scouring and heat treatment by a conventional method, the plain woven fabric was subjected to the following staining treatment. Contamination Treatment 300 cc of a washing liquid with the following composition was put into the pot of a Colorpet dyeing tester (manufactured by Nippon Senzo Kikai), and a 10 cm x 13 cm plain fabric sandwiched in a holder was immersed in the pot and stirred at 50°C for 100 minutes. Used motor oil 1% Sodium alkylbenzenesulfonate 0.02% Sodium sulfate 0.03% Sodium tripolyphosphate 0.02% After lightly washing with water, the sample was sandwiched between filter paper to remove excess contaminated liquid. Next, wash the contaminated sample in a home washing machine at 40°C with 2g/L of Marcel soap.
Washed in warm water for 10 minutes. It was then air-dried.
These staining and washing treatments constituted one cycle, and this cycle was repeated eight times. Next, the contamination rate of the fabric was determined by the following method, and the results were as shown in Table 1. <How to determine contamination rate> Using self-spectrophotometer RC-330 (Shimadzu)
The reflectance at a wavelength of 440 nm was determined. The contamination rate was calculated using the following formula. Contamination rate (%) = Reflectance before contamination - Reflectance after treatment / Reflectance before contamination x 100 In addition, the plain fabric before contamination treatment was exposed to light using a xenon tester to check the degree of discoloration (yellowing). The light fastness was evaluated as 1 to 5 grades by judging on a commercial blue scale, and grades 4 or above were considered to be passed. The results were as shown in Table 1. Example 5 In place of 4 parts of polyoxyethylene glycol monophenyl ether in which one end was blocked as polyoxyalkylene glycol in Example 1, 4 parts of polyoxyethylene glycol monomethyl ether having an average molecular weight of 3000 (n = 67) was used. The same procedure as in Example 1 was carried out except that . The results were as shown in Table 1. The plates made from the resulting polymer also had a transparent appearance. Example 6 4,4'-bis(benzoxazolyl) used as a stilbene optical brightener in Example 1
-4-(benzoxazolyl) in place of stilbene
Example 1 was carried out in the same manner as in Example 1, except that -4'-(5-methylbenzoxazolyl)-stilbene was used. The results were as shown in Table 1. Comparative Example 2 A triazinyl stilbene compound represented by the following formula was used in place of 4,4'-(benzoxazolyl)-stilbene used as a stilbene fluorescent brightener in Example 1. The same procedure as in Example 1 was carried out except that . The results were as shown in Table 1. Comparative Example 3 The same procedure as in Example 1 was carried out except that the single end-capped polyoxyalkylene glycol used in Example 1 was not used. The results are shown in Table 1.

【table】

[Table] Comparative Examples 4, 5 Polyoxyethylene glycol monophenyl ether used in Example 2 (average molecular weight
2000), polyoxyethylene glycol monophenyl ether (average molecular weight 8500, n =
191: Comparative Example 4) or polyethylene glycol with both ends unblocked (average molecular weight: 3000: Comparative Example 5) was used in the same manner as in Example 2. The results were as shown in Table 2. The plate made from the obtained polymer had a transparent appearance in Comparative Example 5, but had a significantly opaque appearance in Comparative Example 4, confirming that the polyether was not copolymerized.

【table】

Claims (1)

[Claims] 1 The following general formula () R ¹ O (R ² O−) _o ... (1) [In the formula, R ¹ is a hydrocarbon group, R ² is an alkylene group,
n is a positive integer indicating the degree of polymerization. ] The following general formula () is added to a copolymerized polyester in which at least some of the ends thereof are copolymerized with a polyoxyalkylene glycol component with one end blocked, represented by 0.001 to 2.0% by weight based on the copolymerized polyester. [In the formula, R ³ and R ⁴ represent a hydrogen atom, an alkyl group, an alkoxy group, an aryl group, or a halogen atom, and a and b are 1 or 2. ] A modified polyester fiber made of polyester containing a stilbene-based fluorescent whitening agent. 2. The modified polyester fiber according to claim 1, wherein the copolymerized amount of the polyoxyalkylene glycol with one end blocked is 0.01 to 4.0 mol% based on the bifunctional carboxylic acid component constituting the polyester. 3. The modified polyester fiber according to claim 1 or 2, wherein the polyoxyalkylene glycol with one end blocked has a degree of polymerization of 30 to 140. 4. The modified polyester fiber according to any one of claims 1 to 3, wherein the stilbene-based optical brightener is 4,4'-bis(benzoxazolyl)-stilbene.