JPH08144151A - Opaque polyester web - Google Patents

Abstract

PURPOSE: To obtain a polyester web having excellent opacity, excellent stain resistance, good whiteness and good abrasion resistance. CONSTITUTION: The opaque polyester web is produced from concentric sheath- core type polyester conjugate fibers wherein the core parts contain 6-20wt.% of titanium dioxide and the sheath parts contain <=0.5wt.% of the titanium oxide and 0.05-0.5wt.% of a benzoxazole fluorescent whitening agent.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyester cloth having excellent opacity, antifouling property, abrasion resistance and good whiteness.

[0002]

2. Description of the Related Art Synthetic fibers such as nylon and polyester are inherently transparent in polymers, so that a cloth for clothing using fibers composed only of the polymer has a drawback that the one worn underneath can be seen through. Have In order to prevent this see-through, generally inorganic white fine particles such as titanium oxide are added to the polymer to form fibers. However, when a large amount of white fine particles are added to obtain opacity, the amount of fine particles present on the yarn surface increases, and the yarn guides, rollers, reeds, and reeds in the false twisting process, twisting process, and weaving process of the yarn. There is a problem of causing wear of knitting needles and the like.

As a countermeasure, a method has been proposed in which a large amount of titanium oxide is added to the core portion and a small amount of titanium oxide is added to the sheath portion of a core-sheath type composite yarn (Japanese Patent Publication No. 63-17926). However, with this method, although the abrasion resistance was good, a whiteness of good was not obtained.

Further, synthetic fibers generally have various characteristics such as high strength, excellent dimensional stability, and good dyeing fastness, but they are hydrophobic in themselves. However, it has the drawback that dirt floating in the air during its handling tends to adhere, dirt due to contact during processing or wearing, and recontamination during washing. Among them, as a method for preventing the adhesion of dirt floating in the air, there are measures such as a method of weaving and knitting antistatic yarn or conductive yarn on a fabric, and a method of using an antistatic agent in the finishing agent together. It has been taken and is producing results.

On the other hand, regarding the method of preventing recontamination by washing, (1) after pretreatment with an alkali, a hydrophilic agent having a functional group for an epoxy group and a drug having two or more glycidyl groups Method (Japanese Patent Publication No. 50-13)
880), (2) A method of adding a special surfactant, acid, water-soluble salt, etc. to an aqueous dispersion of polyester polyether block copolymer and treating it in a treatment liquid within a specific set temperature ( (Japanese Patent Publication No. 53-46960), (3) A method of pre-hydrophilizing the fiber so that it can be easily removed even if it becomes dirty, (4) A fluorine-based water repellent is added to prevent dirt from getting on Many methods have been proposed, but none of them are sufficient. Regarding the former two (1) and (2), the processing is complicated, and the latter (3) hydrophilic treatment method and (4) fluorine-based water repellent antifouling treatment method Each has its own drawbacks, such as limited finishing methods and the difficulty of removing the stain once it begins to adhere.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned situation, and obtains a polyester cloth having excellent antifouling property, opacity, abrasion resistance, and good whiteness. That is the purpose.

[0007]

SUMMARY OF THE INVENTION The present invention achieves the above object and has the following configuration. That is, the present invention provides that "the core contains 6 to 20% by weight of titanium oxide, the sheath contains 0.5% by weight or less of titanium oxide, and the core and the sheath are arranged substantially concentrically. An opaque polyester comprising a core-sheath type polyester composite fiber, which is composed of a yarn containing a benzoxazole optical brightening agent in an amount of 0.05 to 0.5% by weight in a sheath portion. "Cloth" is the main point. Hereinafter, the present invention will be described in detail.

As the polymer used in the present invention, polyester represented by polyethylene terephthalate is mainly used, but cationic dye dyeable polyester obtained by copolymerizing sodium sulfoisophthalic acid may be used.

The fiber used in the present invention is a core-sheath type polyester composite fiber in which the core and the sheath of the cross section of the fiber are concentrically arranged. The two polymer compositions of the core and the sheath are
One core is an opaque polymer with increased opacity,
The other sheath is an opaque white polymer and is composed of these two types of opaque polymer layers.

First, the titanium oxide used in the present invention may be a conventionally known one. The amount of titanium oxide added to the core in the present invention is 6 to 20 to obtain opacity.
A blending amount of wt% is required. When the content of titanium oxide is less than 6% by weight, the effect of opacity is insufficient and unsuitable, and when it is 20% by weight or more, the opacity is good, but yarn breakage occurs during spinning. It is unsuitable because it makes the yarn formability difficult. It is preferably 8 to 15% by weight. To improve whiteness and opacity, a benzoxazole-based optical brightening agent may be added to the core, if necessary. It is necessary that the content of titanium oxide in the sheath is 0.5% by weight or less. It should be noted that if the blending amount is more than 0.5% by weight, there will be a problem in abrasion resistance.

Further, a benzoxazole-based optical brightening agent is blended in the sheath portion. As the benzoxazole-based optical brightening agent, any product may be used, but it is commercially available from Eastman Kodak Company. Yeast Bright OB-1 (trade name) is preferably used. The amount of the optical brightener added is required to be in the range of 0.05 to 0.5% by weight, preferably 0.1 to 0.4% by weight. If the amount of the fluorescent whitening agent added is less than 0.05% by weight, the effect of improving the whiteness of the fiber and the opacity effect may be insufficient, which is not suitable. When the amount added is more than 0.5% by weight, not only the whiteness improving effect is saturated but also the fiber tends to yellow, which is not preferable. Although the reason why the optical brightening agent is mixed with the polyester polymer is not clear, it has much less recontamination due to washing with water and has excellent antifouling property than the optical whitening fiber obtained by the usual dyeing method. It turned out that

In the core-sheath type composite fiber used in the present invention, the core portion and the sheath portion are arranged substantially concentrically, and the volume ratio of the core portion is 6
It is preferably 0 to 90%. If it exceeds 90%, the sheath part may be too thin to obtain the effect of the fluorescent whitening agent, and the effect of abrasion resistance may be reduced, and good whiteness and light resistance may not be obtained. It is not preferable. Also, if it is less than 60%, the opacity effect tends to decrease, which is not preferable. Further, a preferable core volume ratio is 60 to 80%. The complex form is
The core portion and the sheath portion need to be arranged substantially concentrically. This substantially concentric mentioned refers to the maximum value of the thickness of the sheath portion (L _A) and the minimum value ratio _{(L B) (L A /} L B) is 1.5 or less.

A knitted fabric is knitted and woven using the core-sheath composite yarn described above. When knitting a knit, the knitting structure may be any conventionally known knitting structure. Further, when a woven fabric is woven by using this yarn as either a warp or a weft, or both as a warp and a weft, the woven structure of the woven structure is any conventionally known woven structure. be able to. Since the obtained cloth has a good whiteness, scouring, drying, and heat setting are performed by a conventionally known method, and dyeing is unnecessary. However, you may print.

[0014]

[Function] Like the opaque polyester cloth of the present invention,
When the fiber core contains a high concentration of titanium oxide and the sheath contains a small amount of a low concentration of titanium oxide and a benzoxazole-based optical brightener, the whiteness of the sheath is insufficient due to the low concentration of titanium oxide. Is supplemented with a benzoxazole-based optical brightener, while the wear-resistant sheath due to the low concentration of titanium oxide protects the core with high wear resistance and poor wear resistance. The benzoxazole-based optical brightening agent kneaded into the sheath provides antifouling properties for unknown reasons, and therefore provides good whiteness, opacity, and abrasion resistance. Thus, it becomes possible to obtain an opaque polyester cloth having both the antifouling property and the antifouling property.

[0015]

EXAMPLES Next, the method for producing the polyester cloth of the present invention will be described in more detail with reference to Examples. The measurement and evaluation of the performance of the cloth in Examples were carried out by the following methods. (1) Opacity Magic ink (felt pen) in a grid pattern on a white mount
Draw a black line with a width of 5 mm with a dry measurement cloth or a wet measurement cloth containing 100% by weight of water and place it on the mount.
In the brightness of 00 lux, the transparency of the black line from the upper part of the measurement cloth was judged relative to the naked eye, and evaluated by the following four grades. ◎: Very good ○: Good △: Slightly bad
×: Bad

(2) Whiteness A sensory test was conducted to relatively evaluate the following four levels. ◎: Very good ○: Good △: Slightly bad
×: Poor (3) Abrasion resistance A copper plate having a thickness of 0.5 mm was run for 30 minutes at an angle of 90 ° between the copper plate and the yarn at a thread tension of 0.5 g / d and a running speed of 150 m / min. The depth of wear of the subsequent copper plate was measured with a microscope and evaluated relatively in the following four stages. ◎: Very good ○: Good △: Slightly bad
×: Bad

(4) Antifouling property A synthetic pollution source of 0.75 g, 5 g of sodium tripolyphosphate and 5 g of sodium laurylbenzenesulfonate mixed with the following oily and dry pollutants in a ratio of 3: 1 was made up to 1 liter with distilled water. Dispersion preparation was performed to prepare a recontamination liquid. [Oil-based pollutant] Stearic acid 12.5 wt% Oleic acid 12.5 〃 Hardened oil 12.5 〃 Olive oil 12.5 〃 Cetyl alcohol 8.5 〃 Solid paraffin 21.5 〃 Cholesterol 5.0 〃 Carbon black １. 0 total 100.0% by weight

[Dry Pollutant] Clay 55.0% by weight Portland cement 17.0 〃 ferric oxide 0.5 〃 γ-decane 8.75 〃 carbon black 1.75 〃 silica gel 17.0 〃 total 100 0.0% by weight

Next, using a rounder meter tester used for the wash fastness test method of JIS-L-0844, 200 ml of the recontamination liquid and 10 steel balls used for the wash fastness test method were put into a test bottle. , 5
Four pieces of a white cloth of a test piece cut into a size of 5 cm × 5 cm were put and hermetically sealed, and a treatment was performed at 40 ± 2 ° C. for 1 hour. After that, the test cloth is taken out, rinsed with running water, further washed with 100 ml of water at 40 ° C for 10 minutes with a rounder meter, then the test piece is taken out, rinsed with running water, and again rounded with 100 ml of water at 25 ° C. It was washed with a meter for 10 minutes, rinsed with running water twice, then dehydrated and dried with a tumbler. After drying, the grade was evaluated with a gray scale for contamination. Judgment is made in 5 steps, and 5
Grade 1 indicates that there is no recontamination and is good, and Grade 1 indicates that there is significant recontamination (darkening).

Example 1 An opaque polyester composition prepared by adding 6% by weight, 8% by weight, 13% by weight and 20% by weight of titanium oxide to polyethylene terephthalate was prepared for the core of concentric core-sheath composite fibers. . Next, for the sheath portion, a polyester composition prepared by adding 0.5% by weight of titanium oxide to polyethylene terephthalate was prepared.

These polyester compositions were used in a conventional sheath-core composite spinning apparatus to form a yeast polyester composition in the sheath portion during yeast spinning OB-1 (benzoxazole-based optical brightening agent, manufactured by Eastman Kodak Company). ) To 0.
The core-sheath composite yarn was melt-spun by adding 2% by weight and stretched by an ordinary method to obtain a 70-denier / 36 filament of a concentric core-sheath composite yarn having a core portion of 75% and a sheath portion of 25%.

Using this composite yarn, a warp density of 103 yarns /
Weaving a plain weave with a inch and a weft density of 80 threads / inch, followed by relaxing and scouring according to the usual method, then using a heat setter for 17
The fabric of the present invention was obtained by heat setting under the conditions of 0 ° C. for 30 seconds.

For comparison with the present invention, in this example, the amount of titanium oxide in the core of the core-sheath composite yarn was set to 5% by weight, the optical brightening agent in the sheath was omitted, and the amount of titanium oxide was adjusted to 0. A comparative fabric (Comparative Example 1) was obtained in the same manner as in this example except that the amount was 7% by weight.

Measuring the performance of the invention and comparative fabrics,
The results are evaluated and the results are shown together in Table 1.

[0025]

[Table 1]

As is clear from Table 1, the polyester fabric of the present invention is excellent in opacity, stain resistance, whiteness and abrasion resistance. In the comparative example in which the benzoxazole-based optical brightening agent was not used in the core and the amount of titanium oxide added was 5% by weight, the opacity and the antifouling property were poor.

Example 2 In Example 1, the amount of titanium oxide in the core was 8% by weight, and the amount of optical brightener was 0.05% by weight and 0.1% by weight, respectively.
Example 1 except that the weight%, 0.3 weight% and 0.5 weight% are used.
A polyester fabric of the present invention was obtained by the same method as above.

For comparison with the present invention, the amount of the optical brightening agent in the sheath portion of the composite yarn used in this example was 0.03 each.
A comparative fabric was obtained by the same method as that of this example except that the weight percentages (Comparative Example 2) and 0.6 wt% (Comparative Example 3) were used.

Measuring the performance of the fabrics of the invention and of the comparison,
The results are evaluated and the results are shown together in Table 2.

[0030]

[Table 2]

As is clear from Table 2, the polyester fabric of the present invention is excellent in opacity, stain resistance, whiteness and abrasion resistance. Also, it can be seen that when the amount of the fluorescent whitening agent added is increased to 0.6% by weight (Comparative Example 3), good whiteness cannot be obtained.

[0032]

EFFECTS OF THE INVENTION According to the present invention, by blending titanium oxide in the core and optical brightener and titanium oxide in the sheath to form a core-sheath type composite fiber, excellent opacity, antifouling property and good A polyester cloth having excellent whiteness and abrasion resistance can be obtained. The cloth of the present invention having such characteristics is a material suitable for sports clothing such as swimwear and tennis wear and various clothing applications.

Claims (1)

[Claims] 1. A core in which the core contains 6 to 20% by weight of titanium oxide, the sheath contains 0.5% by weight or less of titanium oxide, and the core and the sheath are arranged substantially concentrically. An opaque polyester fabric, which is a sheath-type polyester composite fiber and is composed of a yarn in which the sheath part contains 0.05 to 0.5% by weight of a benzoxazole-based optical brightening agent. .