JP3097967B2 - Titanium oxide-containing fiber having good light resistance and method for producing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an organic synthetic fiber comprising a thermoplastic resin containing a large amount of titanium oxide,
It relates to a fiber having extremely good light fastness.

[0002]

2. Description of the Related Art In recent years, it has been medically proven that skin cancer occurs when a human body is exposed to sunlight for a long time.
As a fiber used for clothes, curtains, hats, parasols and the like, a fiber added with a large amount of various pigments and imparted with a property of shielding sunlight has been demanded. Titanium oxide is the most common pigment used for this.

[0003]

However, when a large amount of titanium oxide is kneaded into a thermoplastic fiber constituting polymer and spun, the resulting fiber has light-fast discoloration resistance, that is, the fiber turns yellow when exposed to sunlight. At present, it is difficult to use it for applications requiring whiteness, for example, interiors such as curtains, shirts, golf wear, tennis wear, tennis pants, and clothing.

The present invention overcomes the above-mentioned problems of the prior art, that is, provides a fiber which contains a large amount of titanium oxide but is extremely excellent in light discoloration resistance. In other words, applications that require high light discoloration resistance, such as curtains, shirts, golf wear, tennis wear, tennis pants, hats, parasols, beachwear, etc. It is intended to provide.

[0005]

According to the present invention, there is provided a fluorescent compound [A] which is a fiber made of a thermoplastic resin containing 2% by weight or more of titanium oxide and has a reflective property represented by the following formula [I]. And a titanium oxide-containing organic synthetic fiber, wherein the non-fluorescent coloring compound [B] is provided in a quantitative ratio represented by the following formula [II]. λ _A + 15 ≧ λ _B ≧ λ _A -15 [I] However, λ _A is the color component only of the above compound [A].
When the fiber contained 2% by weight, the wavelength (nm) at the maximum reflectance determined from the reflection spectrum of the visible part when measured under white light illumination of a xenon light source, and λ _B was the above-mentioned coloring component. The wavelength (nm) obtained in the same manner as described above when only 0.4% by weight of the compound [B] is contained. The amount of _{^{5 × 10 -4 ≦ C B /}} C A ≦ 1 × 10 -2 ····· [II] However, C _A compound amount (wt%) of [A], C _B compound [B]
(% By weight). Also, the present invention relates to a method for preparing titanium oxide at 2% by weight.
A method for producing a titanium oxide-containing organic synthetic fiber, comprising treating a fiber comprising a thermoplastic resin containing the above with an aqueous solution containing the above compound [A] and compound [B] at the above quantitative ratio [II]. Is the way. In the above description of λ _A and λ _B ,
Titanium oxide is not included in the coloring components. Therefore, λ _A and λ _B are compounds that color the fiber of the present invention.
It means the maximum reflectance wavelength (nm) when one of [A] and [B] is colored.

When a fiber is dyed with a fluorescent dye, the molecules of the fluorescent dye (fluorescent compound) incorporated in the fiber highly express absorption and excitation in the near ultraviolet region to increase the reflectance in the visible region, As a result, it is known that the amount of light emission in the visible region is improved to make the fiber excellent in whiteness. However, in the case of a fiber containing a large amount of titanium oxide, the titanium oxide-containing thermoplastic resin constituting the fiber preferentially absorbs near-ultraviolet light. Also, since the fluorescent compound molecules are suppressed from exhibiting the above-described absorption excitation, the amount of light emission in the visible region decreases, and as a result, the function of the fluorescent compound is not exhibited.
As long as the function of the fluorescent compound is not exhibited, the light discoloration resistance of the fiber is hardly improved.

The present inventors have conducted intensive studies on these points, and have found a surprising fact. That is, in the fiber, the suppression of absorption excitation in the near ultraviolet of the fluorescent compound to be blended can be achieved by adding a specific compound, and at the same time, the light discoloration resistance of the fiber is significantly improved. It was found. The specific compound is a non-fluorescent and non-fluorescent colored compound that exhibits a maximum reflectance at substantially the same wavelength as the emission wavelength representing the maximum reflectance in the visible portion of the fluorescent compound described above, particularly a non-fluorescent dye molecule. That is, when this compound is blended, it has become possible to obtain a fiber having an extremely good light discoloration resistance, which is the object of the present invention.

[0008] The thermoplastic resin constituting the fiber of the present invention comprises:
Polyamides such as nylon 6, nylon 66, nylon 610, nylon 12, nylon 11, nylon 4, nylon 46, etc .; polyesters such as polyethylene terephthalate, polybutylene terephthalate and polyhexamethylene terephthalate; and polyolefins such as polyethylene and polypropylene. It is selected, especially in the case of polyethylene terephthalate, polyester-based polymer containing polybutylene terephthalate as a main component,
When a large amount of titanium oxide is added, yellowing due to light exposure is remarkable, and the light discoloration resistance obtained by the presence of the compounds [A] and [B] is also extremely large. . As these polyester-based polymers, those obtained by copolymerizing a small amount of a third component can be used. Describing the polyester-based polymer in more detail, polyester-based polymers include terephthalic acid, isophthalic acid, naphthalene-2,5-dicarboxylic acid, α, β- (4-carboxyphenoxy) ethane,
4,4'-dicarboxydiphenyl, bisphenol A
Alkylene oxide adduct, adipic acid, azelaic acid, sebacic acid, ethylene glycol, diethylene glycol, 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, cyclohexane-
Polyester polymers synthesized from aromatic, aliphatic, and alicyclic dicarboxylic acids and diols such as 1,4-dimethanol, polyethylene glycol, and polytetramethylene glycol, and oxycarboxylic acids. As described above, a polyester polymer in which at least 90 mol%, particularly at least 90 mol%, are ethylene terephthalate units or butylene terephthalate units is preferred.

[0009] Of course, in the present invention, the thermoplastic resin to which titanium oxide is added does not have fiber forming properties by itself, but can form fibers by compounding or mixed spinning with other fiber forming polymers. Any of these can be used in the present invention. Therefore, the fiber comprising a thermoplastic resin containing 2% by weight or more of titanium oxide as referred to in the present invention means all of a single spun fiber from the resin, a mixture of the resin with another resin, and a composite fiber. .
Of course, even when the thermoplastic resin containing 2% by weight or more of titanium oxide has a fiber forming property, a mixed spun fiber or a composite spun fiber obtained by using it as one component is included in the present invention. When the fiber of the present invention is a fiber obtained by mixed spinning or composite spinning, it is preferable that 10% by weight or more of the fiber constituent component is a thermoplastic resin containing 2% by weight or more of titanium oxide.

As described above, in the present invention, the thermoplastic resin containing 2% by weight or more of titanium oxide may be a resin having no fiber-forming ability by itself. In this case, a suitable fiber can be obtained by forming a core-sheath type composite fiber having the resin as a core component and another fiber-forming resin as a sheath component. In particular, when a thermoplastic elastomer is used as a resin constituting a thermoplastic resin containing 2% by weight or more of titanium oxide, spinnability is less likely to be impaired despite the large amount of titanium oxide added. As the plastic elastomer, a hydrogenated product of a block copolymer composed of an aromatic vinyl block and a conjugated diene block is more preferable because spinnability is not impaired even when a large amount of titanium oxide is added.

Preferable examples of such a block copolymer include, for example, a hydrogenated product of SBS (polystyrene-polybutanediene-polystyrene block copolymer) and SIS (polystyrene-polyisoprene-polystyrene block copolymer). A hydrogenated product of a polymer), a hydrogenated product of a SI (polystyrene-polyisoprene block copolymer), a hydrogenated product of a poly-α-methylstyrene-polyisoprene-polyα-methylstyrene block copolymer,
Hydrogenated block copolymer of poly α-methylstyrene-polybutadiene-poly α-methylstyrene, poly α
-Methylstyrene-polyisoprene hydrogenated product of a block copolymer, and the like. Particularly, a hydrogenated product of a triblock copolymer having a polyaromatic vinyl block at both terminal blocks is preferable. Hydrogenates are preferred.

In the block copolymer used in the present invention, it is necessary that 30% or more of the conjugated diene portion is hydrogenated. If the content is less than 30%, the block copolymer is melt-spun. Has the disadvantage of thermal decomposition. Note that the hydrogenation rate referred to here means the rate at which the carbon-carbon unsaturated double bond in the conjugated diene contained in the block copolymer is hydrogenated. The iodine value after addition is determined, and the latter is calculated by calculating the percentage of the latter relative to the former. More preferably, the hydrogenation rate is 50% or more.

The number average molecular weight of the block copolymer used in the present invention is preferably 30,000 or more and 150,000 or less, particularly preferably 40,000 or more and 100,000 or less. The number average molecular weight is determined by a conventional GP.
It is determined by the C method. The weight ratio of the aromatic vinyl block / conjugated diene block in the block copolymer is preferably in the range of 5/95 to 80/20, particularly preferably in the range of 10/90 to 70/30. Examples of the aromatic vinyl include styrene and methylstyrene, and examples of the conjugated diene include isoprene, butadiene, and piperine. The block copolymer used in the present invention is mainly composed of an aromatic vinyl block and a conjugated diene block, but has a functional group such as a carboxyl group, a hydroxyl group, or an acid anhydride at a molecular terminal in a molecular chain. You may.

Further, in the present invention, when a large amount of titanium oxide is present on the fiber surface, the surface of a drawing roller, a drawing plate, a guide, a traveler or the like may be scraped off and worn by the running fiber in a fiber drawing step or a heat treatment step. Becomes Therefore, in order to prevent such abrasion, a thermoplastic resin containing a large amount of titanium oxide in the core component, such as a polyester-based polymer, and a thermoplastic resin containing a small amount or no titanium oxide as the sheath component, such as a polyester-based polymer, are used. Wound core-sheath composite fibers are preferred. In particular, when the fiber is a long fiber (filament), such a composite fiber is preferable.

As a method for obtaining such a core-sheath type conjugate fiber, the above-mentioned sheath component polymer and core component polymer are heated and melted by separate molten yarns, and each is fed to a spinneret by an ordinary extrusion device. Immediately before the spinneret, both polymers are combined, for example, in a composite shape of a concentric core-sheath type, and are extruded. The obtained yarn is wound or temporarily stored in a can and then further subjected to a drawing heat treatment.

In the present invention, the content of titanium oxide in the above-mentioned thermoplastic resin varies depending on the target fiber, but the content of titanium oxide must be 2% by weight or more. When the content is less than 2% by weight, the problem to be solved by the present invention itself does not exist, and the solar light shielding property also decreases. However, when the content is 10% by weight or more, it is difficult to obtain a fiber having excellent whiteness and good light resistance, which is an object of the present invention. Here, titanium oxide refers to titanium dioxide, and the average particle size of titanium dioxide is preferably 5 μm or less, more preferably 1 μm or less. If the particle size is too large, problems such as clogging in a filter during spinning and yarn breakage occur, and further, yarn breakage occurs during stretching. Here, the average particle size is a value measured using a particle size distribution analyzer (CAPA-500) manufactured by Horiba, Ltd.

Further, in the present invention, in order to enhance the spinnability of a thermoplastic resin containing a large amount of titanium oxide, it is preferable to add a metal salt of stearic acid or a titanium-based coupling agent. Salts, calcium salts, zinc salts and the like are preferable, and among them, magnesium stearate is preferable. The addition amount of these compounds is 1 to 1 with respect to titanium dioxide.
0% by weight is preferred. Further, in order to enhance the kneading properties of the thermoplastic resin and titanium oxide, it is preferable that various dispersing aids are added.

The fluorescent compound [A], which is an important component for achieving the object of the present invention, is The So So.
Citey of Dysers and Colori
sts and American Association
of Textile Chemists and C
The color index is a colorant classified as a fluorescent dye in the color index of the co-editing of the olourists, and particularly includes stilbene-based, coumarin-based, and benzoxazole-based compounds. The amount is 0.1 to the weight of the fiber.
The range of from 0.5 to 0.5% by weight is preferred. The fluorescent compound [A] may be added to a thermoplastic resin containing 2% by weight or more of titanium oxide. In the case of a core-sheath type composite fiber having such a resin component as a core component, it is mainly used. It may be contained in the sheath component or may be focused on the surface of the sheath component.

However, such a fluorescent compound [A] alone cannot prevent photo discoloration (yellowing) of a thermoplastic resin containing a large amount of titanium oxide. In the present invention,
In order to solve this point, the above-mentioned non-fluorescent coloring compound [B] is added. Non-fluorescent colored compound [B] referred to here
Is a compound having the specific visible portion reflection characteristics as described above, and in particular, disperse dyes and acid dyes classified as dyes in the color index described above are preferable.
When a polyester-based polymer is used as the fiber-forming thermoplastic polymer, a disperse dye among the above compounds is particularly preferable.

[0020] As mentioned above, it satisfies the compound [A] with the compound [B] the visible portion maximum reflectance wavelength (nm) λ _A and lambda _B is _{λ A + 15 ≧ λ B ≧} λ A -15 of Is essential, and when a combination of the fluorescent compound [A] and the non-fluorescent colored compound [B] out of this range is used, a fiber excellent in light discoloration resistance (yellowing), which is the object of the present invention, is used. I can't get it. Further, the compounding ratio of the fluorescent compound [A] to the non-fluorescent light compound [B] is 5 × 10 ⁻⁴ or more and 1 × 10 ^−2.
The following are necessary, and if it is out of this range, the intended purpose will not be achieved. Similarly to the compound [A], the non-fluorescent coloring compound [B] may be added to a thermoplastic resin containing a large amount of titanium oxide, or may be added to another component. Good. Of course compound [A]
The component and the compound [B] component may be present in the same portion of the fiber or in separate portions, but are preferably present in the same portion.

Examples of the method of blending the fluorescent compound [A] and the non-fluorescent coloring compound [B] into the above-mentioned fibers include a kneading method during spinning during fiberization and a post-treatment method after fiberization. However, a post-treatment method is preferable in consideration of the processability in practical use, and more preferably, a fiber made of a thermoplastic resin containing a large amount of titanium oxide is prepared using the above-mentioned compound [A] and compound [B]. A method of immersing the fibers in an aqueous solution containing them in a quantitative ratio and heating, or a method of applying the aqueous solution to the fibers by a method such as padding, spraying, or showering, and performing heat treatment.

The fibers referred to herein include long fibers such as multifilaments, short fibers such as staples, filament yarns, spun yarns, fibers of the present invention and natural fibers, semi-synthetic fibers,
Other processed yarns such as a mixed fiber with other synthetic fibers, a mixed spun yarn, a plied yarn, an entangled yarn, a crimped yarn and the like may be used. Furthermore, the fiber product of the present invention may be any of fiber products such as knitted and woven fabrics, non-woven fabrics, final clothing, towels, curtains and the like formed by using these fibers or yarns as a part or all thereof.
The drawing shows an example of the cross-sectional shape of the fiber of the present invention. In the drawing, the hatched portion is a thermoplastic resin component containing a large amount of titanium oxide, and the non-hatched portion contains a small amount or no titanium oxide. There is no thermoplastic resin component. 1 shows a single-core sheath, FIG. 2 shows a three-core sheath, FIG. 3 shows a four-core composite fiber, and FIG. 4 shows a single spun fiber of a thermoplastic resin containing a large amount of titanium oxide.

[0023]

EXAMPLES The present invention will be described below in detail with reference to examples and the like, but the present invention is not limited thereto. Example 1 Polyethylene terephthalate (hereinafter abbreviated as PET) containing 5% by weight of titanium dioxide and 0.2% by weight of magnesium stearate was used as a core component, while PET containing 0.5% by weight of titanium dioxide was used. Each component is melted and extruded by a separate extruder so as to become a sheath component, and the two components are combined at a nozzle portion at a spinning temperature of 290 ° C., and the composite weight ratio of the core component and the sheath component is changed. The resulting mixture was wound into a desired shape at a spinning speed of 1000 m / min to obtain various spinning yarns having different contents of thermoplastic resins containing a large amount of titanium dioxide. The obtained spun yarn was stretched under the conditions of a hot roller of 80 ° C., a plate temperature of 135 ° C. and a draw ratio of 3.3 times to obtain a multifilament of 75 denier and 24 filaments. Using these drawn yarns, a warp density of 95 yarns /
A plain woven fabric is produced at a weave density of 60 wefts / inch and refined, and a fluorescent compound [ The immersion heat treatment was performed by changing the mixing ratio of the compound [A] and the non-fluorescent coloring compound [B], and the light resistance (fading) was evaluated according to JIS-L0842. <Liquid immersion heat treatment conditions> owf:% by weight based on fiber
Fluorescent compound [A]: Uvitet EBF (manufactured by Ciba Geigy) 1% owf <benzoxazole-based compound> Two types of non-fluorescent coloring compound [B] Abbreviations (B-1): Sumikaron UL Blue G
F y% owf (B-2): Sumikaron Violet E-
RL y% owf Dispersant: Irgasol NA 1 g / l Bath ratio 50: 1 Heating temperature 130 ° C Heating time 40 minutes How to determine the compounding ratio of compound [A] and compound [B] Soxhlet extraction of the treated fiber with dimethylformamide for 72 hours The extract was subjected to a spectrophotometer to determine the compounding ratio from the absorbance measurement. By this dyeing treatment, the dyeing amount of the fluorescent compound [A] to the fiber is 0.1.
It was 2% by weight.

In Examples 1 and 2, the fluorescent compound [A] and the non-fluorescent colored compound [B] satisfying the above formulas [I] and [II] are compounded to obtain an oxidation having good light resistance. It becomes a titanium-containing fiber. Comparative Example 1 is an example of a fiber having a low content of titanium oxide which does not require the subject of the present invention. Comparative Examples 2 to 4 are examples of fibers that need to solve the problem of the present invention, which do not satisfy the above-mentioned requirements. Comparative Examples 5 to 7 are examples in which the conditions of the above formulas [I] and [II] are deviated from the fibers which need to solve the problem of the present invention.

[0025]

[Table 1]

[Brief description of the drawings]

FIG. 1 is an example of a cross-sectional shape of a fiber of the present invention.

FIG. 2 is another example of the cross-sectional shape of the fiber of the present invention.

FIG. 3 is still another example of the cross-sectional shape of the fiber of the present invention.

FIG. 4 is another example of the cross-sectional shape of the fiber of the present invention.

[Explanation of symbols]

A component containing a small amount or no titanium oxide b) A component containing a large amount of titanium oxide

────────────────────────────────────────────────── (5) References JP-A-62-238825 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) D01F 1/00-8/16 D06M 13 / 00-15/72

Claims (2)

(57) [Claims] 1. A fluorescent compound [A] and a non-fluorescent colored compound [B], which are fibers made of a thermoplastic resin containing 2% by weight or more of titanium oxide and have reflection properties represented by the following formula [I]: Is provided in a quantitative ratio represented by the following formula [II]. λ _A + 15 ≧ λ _B ≧ λ _A− 15 [I] where λ _A is the color component and only the above compound [A].
The wavelength (nm) at the maximum reflectance determined from the reflection spectrum of the visible part when the fiber is contained under a white light illumination of a xenon light source when containing 2% by weight, and λ _B is The wavelength (nm) obtained in the same manner as described above when only 0.4% by weight of the compound [B] is contained. The amount of ^{_{5 × 10 -4 ≦ C B /}} C A ≦ 1 × 10 -2 ····· [II] However, C _A compound amount (wt%) of [A], C _B compound [B]
(% By weight). 2. A fiber comprising a thermoplastic resin containing 2% by weight or more of titanium oxide, wherein the compound [A] and the compound [B] according to claim 1 are contained in a quantitative ratio [II] according to claim 1. A method for producing an organic synthetic fiber containing titanium oxide, characterized by treating with an aqueous solution to be treated.