JPS59192724A - Preparation of synthetic yarn having light resistance - Google Patents

Abstract

PURPOSE:To obtain the titled yarn having improved light resistance simply, by attaching an aqueous dispersion of benzotriazole ultraviolet light absorber to undrawn yarn prepared by subjecting a thermoplastic resin to melt spinning, drawing it. CONSTITUTION:A thermoplastic resin preferably blended with a colorant is subjected to melt spinning, a preferable amount of 0.2-2% owf. of an aqueous dispersion of benzotriazole ultraviolet light absorber [preferably a compound shown by the formula (R1 and R2 are H, 1-5C alkyl, or alkoxy; X is H, or halogen)] having <=5mum adjusted particle diameter is attached to the prepared undrawn yarn, which is drawn, to give the desired yarn. EFFECT:The yield of ultraviolet light absorber is improved, and the interior of the surface part of yarn is provided with the absorber. USE:Yarn for interior automotive trim.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing thermoplastic synthetic fibers with excellent light resistance. Specifically, the present invention relates to a method for producing thermoplastic synthetic fibers with excellent light resistance. The present invention relates to a method for producing an excellent thermoplastic synthetic resin.

Although various methods for improving the sunlight fastness of dyed products have been proposed, very few have been put to practical use, and the reality is that dyes with excellent sunlight fastness are usually selected and used. However, in recent years, there has been a tendency for textile products to be used more and more for automobile interiors, and the required performance for light resistance in this case is not the level of blue scale grade 4 or higher for clothing, but for 800 hours at 88°C with a fade meter or 400 hours at 88°C. It is extremely severe, with a gray scale of grade 4 or above, which discolors and fades due to irradiation over time. However, there are very few dyes that can meet these standards, and although some methods have been used to dye polyamide fibers with highly light-fast metal-containing dyes, these dyes tend to cause streaks and There are problems such as a limitation in hue, making it difficult to obtain vivid colors, and the substrate being susceptible to yellowing due to heat or gas. Also, when polyester fibers are dyed with disperse dyes, depending on the dye, it is possible to give them considerable light resistance, but the internal temperature of a car left outdoors in the summer can reach around 100°C, and the dyeing of disperse dyes Problems include discoloration due to sublimation and sublimation contamination of other components.

Furthermore, as a method of improving the sunlight resistance of dyed polyester fibers or preventing deterioration due to sunlight irradiation, it is also known to add ultraviolet absorbers and antioxidants in the stage before spinning or in the post-treatment immediately before dyeing. Furthermore, a method has also been proposed in which a polyester resin containing an antioxidant is used for spinning before spinning, and then post-treatment is performed with an ultraviolet absorber (Japanese Patent Publication No. 51-27788, etc.). However, if UV absorbers are added to the polyester resin before spinning, they will sublimate during melt spinning, leading to problems such as worsening the working environment and yellowing of the fibers. In this method, the solubility of the UV absorber is low, which tends to result in poor dispersion (and its utilization rate is low, so a large amount of the UV absorber must be used, and as a result, the UV absorber does not reach the outer layer of the fiber). It tends to be deposited unevenly, especially when dyeing cotton or cheese, it adheres in the form of tar on the innermost or outermost layer, and when dyeing fabric, it forms streaks and does not achieve a uniform light resistance improvement effect. It is also possible to apply the UV absorber by dissolving it in a solvent, but with this method, it is not possible to perform the treatment at the same time as dyeing, and it also requires special adhesion equipment; There are some drawbacks, such as the fact that it is adsorbed to the fibers and reduces its fastness, so a solvent removal process is essential, and (2) the light stabilizer cannot be exhausted.

Under these circumstances, the inventors of the present invention have conducted intensive research in an attempt to establish a technique that allows ultraviolet absorbers to easily penetrate and fix into the surface layer of synthetic fibers such as polyester fibers. The present invention was completed as a result of such research, and has a structure in which an aqueous dispersion of a benzotriazole ultraviolet absorber is attached to an undrawn yarn obtained by melt-spinning a thermoplastic synthetic resin such as a polyester resin. The gist is that the film is stretched and then stretched.

That is, in the present invention, an aqueous dispersion of a specific ultraviolet absorber is applied to the undrawn yarn, which has a low degree of crystallinity and orientation after melt spinning and before stretching, to penetrate into the surface layer of the fiber, and then the yarn is stretched. By doing this, the UV absorber is fixed inside the surface layer of the fiber, and it can be easily attached to the fiber in the same way as a normal oiling treatment, and the UV absorber is evenly distributed inside the surface layer of the fiber. Moreover, it can be firmly attached, and the strength retention rate of the obtained fiber after irradiation with a fade meter or the like is greatly improved.

Moreover, even when dyeing is performed after stretching, the corrosion resistance of dyed products can be significantly improved, and even when applied to fibers that are melt-spun by blending coloring substances into synthetic resins, irradiation using a fade meter, etc. Subsequent discoloration and fading can be suppressed, and strength deterioration can be significantly suppressed.

The material of the thermoplastic synthetic fiber to which the present invention is applied is not particularly limited, and any type of thermoplastic synthetic resin that can be melt-spun may be used; however, in relation to the ultraviolet absorber used, The objects of the present invention are most effectively achieved by polyesters whose repeating units are mainly alkylene terephthalate, such as polyethylene terephthalate, polybutylene terephthalate, and cationically dyeable ethylene terephthalate copolyesters.

Next, the ultraviolet absorber used in the present invention is an aqueous dispersion of a benzotriazole compound, and among these compounds, the most preferable one is represented by the following general formula (wherein R1 and R2 are hydrogen atoms, and the number of carbon atoms is 1 to 1). 5 represents an alkyl group or an alkoxy group, and X is a hydrogen atom or a halogen atom) Among the compounds of the above general formula, particularly preferred are compounds in which R is a methyl group, R2 is a tertiary-butyl group, and X is a chlorine atom. , or a compound in which R1 is a methyl group and both R2 and
~296owf, Teal.

As mentioned above, the benzotriazole compound is attached to the undrawn yarn as an aqueous dispersion, but when preparing the aqueous dispersion, a surfactant may be used to form a dispersion with a particle size of approximately 5 μm or less. desired.

There are no particular restrictions on the means for producing such a fine dispersion, but it is preferable to grind the benzotriazole compound, surfactant, and water in a grinder such as a Sandominope ball mill or a colloid mill using steel balls, glass peas, etc. This is a wet grinding method in which the material is forcibly stirred with a porcelain ball or the like. At this time, if the grinding is insufficient and the particle size exceeds 5 μm, the stability of the dispersion liquid will be insufficient, and if left to stand, the benzotriazole compound will sediment and separate overnight, making redispersion difficult. Whether the ultraviolet absorber (aqueous dispersion) prepared as a result is attached to the undrawn yarn alone or mixed into the oil and attached together with the oil, the benzotriazole compound will be present at the bottom of the storage tank. It settles and it becomes impossible to secure the target amount of adhesion. On the other hand, in the case of an aqueous dispersion having a particle size of 5 μm or less, such a problem does not occur, and a predetermined amount of the benzotriazole compound can be uniformly adhered to the surface of the undrawn yarn. Examples of surfactants include polyethylene glycol alkyl ether, polyethylene glycol alkyl phenyl ether, polyethylene glycol/polypropylene glycol block copolymer and its ether or ester, polyethylene glycol fatty acid ester, sorbitan fatty acid estenope fatty acid monoglyceride, and ethylene oxide addition of alkylamine. Preferred are nonionic surfactants such as sulfates of polyalcohols, or anionic surfactants such as sulfates of higher alcohol sulfates, alkylbenzene sulfonates, soaps, and polyalkylene glycol phenyl ethers. Although these may be used alone, nonionic surfactants such as The highest dispersibility can be obtained by using an active agent and an anionic surfactant together. The amount used is 2 to 50% by weight based on the benzotriazole compound,
More preferably, it is 5 to 80% by weight.

Other preferred ingredients for the aqueous dispersion include formaldehyde condensates of aromatic sulfonic acids,
This component has the effect of increasing the stability of the aqueous dispersion and further increasing the light resistance of the fibers. Specific examples of such condensates include formaldehyde condensates of naphthalenesulfonic acid and formaldehyde condensates of phenolsulfonic acid, and the preferred amount thereof is usually 20 to 200% by weight, preferably 20 to 200% by weight based on the benzotriazole compound. is 50 to 150%. In addition, in order to further improve the dispersion stability of the benzotriazole compound, during or after dispersion, polymer adhesives such as carboxymethyl cellulose, polyvinyl alcohol, hydroxyproylcellulose, glycerin, diethylene glycol, polyethylene glycol, etc. It is also effective to incorporate a small amount of moisture absorbent. Particularly when dispersing a nonionic surfactant alone, it is desirable to use the above-mentioned polymer sizing agent in combination in order to improve dispersion stability.

In the present invention, a spinning oil such as a potassium salt of lauryl phosphate or an ethylene oxide adduct of lauryl alcohol is used in the same way as in normal spinning, but the ultraviolet absorber is added at an appropriate position before or after the spinning oil. The oil may be applied separately, or the ultraviolet absorber may be mixed with the spinning oil and applied simultaneously. In addition, for stretching after spinning, either a method of hot stretching on a heated stretching plate or a method of stretching in a heated water bath may be adopted, and in this case, between spinning and stretching, the temperature is (about 20-25℃) for 6 hours or more, preferably 12 hours.
It is better to leave it for more than 1 hour.

The present invention is roughly constructed as described above, in which an aqueous dispersion of a benzotriazole ultraviolet absorber is applied at a stage after melt spinning and before stretching to allow the ultraviolet absorber to penetrate into the surface layer of the fiber, and then stretched. By doing this, the ultraviolet absorber was fixed inside the surface layer, so that the yield of the ultraviolet absorber was improved and it was possible to apply it uniformly to the inside of the fiber surface layer. Furthermore, since the attachment can be carried out in the same manner as the usual oiling process, before or after it, the equipment and operation for the attachment are extremely simple. (As a result, the light resistance of the synthetic fiber itself can be greatly improved, and when applied to fibers containing colorants, discoloration and fading of the colorant can be greatly improved, improving light resistance and durability at high temperatures. It is possible to obtain outstanding synthetic fibers.

Next, Examples and Comparative Examples will be given to clarify the effects of the present invention.

Example 1 Polyethylene terephthalate with an intrinsic viscosity of 0.65 determined at 30°C in a mixed solvent of phenol/tetrachloroethane (6/4 weight ratio) was kneaded with the coloring materials shown in Table 1 using a master punch method and melt-spun. Immediately, 10% owf of an oil agent having the following component composition was applied. The obtained single fibers were bundled and put into a tow and left for 20 hours. Next, it was stretched approximately 8.5 times in a draw path at 70°C, dried, crimped using a crimper, and cut, and further heat-treated at 160°C x 2 m1n in a bundled state to set the crimp. of fiber was obtained. This was processed using a needle punch machine to create a needle punch cloth, and a light resistance test was conducted using a fade meter without banking. The results are also listed in Table 1.

The oil agent (5) contains a benzotriazole ultraviolet absorber (example), and the oil agent (5) does not contain the same ultraviolet absorber (comparative example).

Oil agent ■
) Ultraviolet absorber x (purity conversion) 5 - (15 mol) adduct of lauryl alcohol was added to Neugen EA (manufactured by Daiichi Kogyo Seiyaku Co., Ltd., nonionic activator)
Example 2 Aqueous dispersion (particle size of 1 μm or less) obtained by crushing and dispersing polyethylene terephthalate with carboxymethylcellulose Example 2 After melt-spinning polyethylene terephthalate with an intrinsic viscosity of 0.65, an oil agent having the same composition as in Example 1 was immediately applied. The undrawn yarn was wound around a pirn and heated at 20℃ for 2 hours.
After leaving it for 4 hours, it was hot stretched to 3.5 times (150 -4
3f). Knit this yarn into a tube and use the usual method to create soda ash 2
s in an aqueous solution containing 17/l and a nonionic activator 1y/l.
I refined o'cxao. Next, the dyes shown in Table 2 were dyed at 180°C for 30 minutes, and after reduction washing, they were thoroughly washed with water and heat set at 170°C for 20 seconds. This knitted fabric was subjected to a light resistance test using a fade meter, and the results shown in Table 2 were obtained.

In addition, the refined knitted fabric was de-knitted again and subjected to fade meter irradiation in the straight yarn state for 80 hours to examine the rate of decrease in strength and elongation due to irradiation, and it was found that the rate of decrease in strength and elongation was 10% for the fabric using oil agent (4). , the elongation reduction rate was 18%, whereas those using oil agent CB) had a strength reduction rate of 45% and an elongation reduction rate of 50%, both of which were extremely high.

Table 2 Example 8 Each of the various compounds listed in Table 8 was mixed and crushed with an activator prepared by mixing a formaldehyde condensate of sodium naphthalene sulfonate and polyethylene glycol lauryl ether at a ratio of 5=1 (weight ratio). A UV absorber with a diameter of 1 μm or less was obtained. This ultraviolet absorber is 2% o in terms of pure content.
The oil bath was adjusted so that the amount of lauryl phosphate potassium salt as a spinning oil was 0.2%owf, and this oil was mixed with 5-sodium sulfoisophthalic acid (2.5 mol 96% based on the total acid components). ) was applied immediately after melt-spinning of polyethylene terephthalate-based polyester. This undrawn yarn was once wound onto a pirn, left to stand at 25°C for 18 hours, and then hot-stretched to 3.5 times (150-4
3f). The obtained yarn was knitted into a tube, refined by a conventional method, and then dyed with a dye solution having the composition shown below.

Staining liquid composition Maxilon Blue GRL (Ciba” 0.296ow
f.

(manufactured by Geigy, cationic dye) Glauber's salt 8y/1 Acetic acid/Sodium acetate pH = 4.0 Bath ratio 1:20 Dyeing conditions = 120°C x 60 minutes The light resistance of the obtained tube knitted fabric is shown in Table 4.

Table 3 Table 4 Gray scale evaluation comparative example 1 After polyethylene terephthalate was spun and hot-stretched by a conventional method, the ultraviolet absorber [■] in Table 8 was added to the aqueous dispersion as in Example 8 to form a surface of the drawn yarn. (5% owf in terms of pure content), and then left at 25° C. for 24 hours, knitted into a tube, and refined in the same manner. After that, it was denited again and then irradiated with a fade meter at 63°C for 300 hours, and the strength retention rate before and after irradiation was examined, but no difference was observed compared to that without using the ultraviolet absorber CI). That is, even when a benzotriazole ultraviolet absorber is used, if it is applied after stretching, it cannot provide an effect of improving light resistance.

Claims (1)

[Claims] A light-resistant synthetic fiber characterized in that an aqueous dispersion of a benzotriazole ultraviolet absorber is applied to an undrawn yarn obtained by melt-spinning a fll thermoplastic synthetic resin, and then stretched. Production method. (2) The benzotriazole-based ultraviolet absorber is a compound represented by the following general formula (Claim 1) where the alkyl group or alkoxy group, X is a hydrogen atom or a halogen atom) (3) The undrawn yarn is thermoplastic synthetic 3. The method for producing a light-resistant synthetic fiber according to claim 1 or 2, which is obtained by melt-spinning a resin with a colorant added thereto.