JPH08176924A - Untransparent nylon fabric - Google Patents

Abstract

PURPOSE: To obtain a nylon fabric, having yellowing preventing properties even for packaging paper materials and gases and further excellent untransparency and a good whiteness degree and excellent in light fastness. CONSTITUTION: This untransparent nylon fabric is composed of a yarn which is a core-sheath type nylon conjugated fiber, containing 6-20wt.% titanium oxide in a core part and <=0.5wt.% titanium oxide and 0.005-0.2wt.% benzoxazole-based fluorescent brightener in a sheath part. In the conjugated fiber, the core and sheath parts are substantially concentrically arranged. Furthermore, a polyamide having >=10g equiv./10<6> g content of amino terminal groups is used in the sheath part of the yarn.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a nylon cloth having excellent opacity, anti-yellowing property, good whiteness and excellent light resistance.

[0002]

2. Description of the Related Art Synthetic fibers such as nylon and polyester are originally transparent in polymers, so that clothing cloths made of fibers made of only those polymers can be seen through. It has the drawback of 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, the cloth obtained by this method does not satisfy the opacity because the hiding effect of white is insufficient.

Polyamide fibers are, by nature, excellent in chemical
Although it has mechanical properties and is widely used as a fiber for clothing and industrial materials, ordinary polyamide fibers have a problem that the whiteness is not sufficient for applications where whiteness is required. In order to solve this problem, a method of adding a fluorescent whitening agent to the production of polyamide fibers has been proposed. For example, JP-A-64-20321 discloses a benzoxazole-based fluorescent whitening agent. , A white-dyed polyamide fiber containing a white inorganic compound and a dispersant is disclosed. However, in the case of this method, since the amount of the white inorganic compound added is small, the hiding effect due to the white color is insufficient, and there is a drawback that the wrapping paper material causes yellowing.

On the other hand, the polyamide fiber has an advantage that it can be easily dyed with an acid dye because it has an amino terminal group, but on the other hand, it has a problem that it is easily yellowed by light or gas, or yellowed by a packaging material. are doing. As a method for preventing the yellowing of the polyamide fiber, especially the yellowing due to the wrapping paper material, there is no effective method for modifying the polyamide fiber, and various methods for modifying the wrapping paper material have been proposed.
For example, a method of applying or impregnating a solution of a specific compound on the inner liner of a wrapping paper material or a corrugated cardboard container has been proposed (Japanese Patent Publication No. 56-48640, No. 60-7759, etc.). For example, although it was possible to prevent yellowing due to the wrapping paper material, it was not possible to prevent yellowing due to gas.

As a method of preventing yellowing due to gas,
A method for reducing the amount of amino terminal groups of fibers has been proposed. For example, in Japanese Patent Laid-Open No. 1-229810, an acid or acid anhydride is added and reacted during melt spinning of a polyamide so that the amount of terminal amino groups is 10%. Disclosed is a method of -30 g equivalent / 10 ⁶ g. This method can prevent the yellowing due to gas, but it cannot prevent the yellowing due to the wrapping paper material.

Yellowing is particularly problematic in the above-mentioned products requiring particularly whiteness, and polyamide fibers having high whiteness and not yellowing have not been developed even to this day. There wasn't.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of such a situation as described above, and has a yellowing preventive property with respect to both wrapping paper material and gas and has excellent opacity. ，
The purpose of the present invention is to obtain a nylon cloth having good whiteness and excellent light resistance.

[0008]

SUMMARY OF THE INVENTION The present invention achieves the above object and has the following configuration. That is, the present invention "contains 6 to 20% by weight of titanium oxide in the core, 0.5% by weight or less of titanium oxide in the sheath, and 0.005 to 0.2% by weight of a benzoxazole-based optical brightener. % Contained,
A core-sheath type nylon composite fiber in which a core portion and a sheath portion are arranged substantially concentrically, and a yarn in which polyamide with an amino terminal group amount of 10 g equivalent / 10 ⁶ g or less is used for the sheath portion The essence is "opaque nylon cloth characterized in that it is characterized". Hereinafter, the present invention will be described in detail.

The fiber used in the present invention is a core-sheath type nylon composite fiber in which the core and the sheath of the cross section of the fiber are concentrically arranged, and two kinds of polymer compositions of the core and the sheath are: One core is an opaque polymer with increased opacity, and the other sheath is an opaque white polymer, which 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. In addition, the nylon cloth of the present invention is also known as nylon 6, nylon 66, which has been conventionally known.
Polyamides such as can be used.

The amount of titanium oxide added to the core of the nylon fiber used in the present invention is required to be 6 to 20% by weight in order to obtain opacity. 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 substance such as a light-proofing agent, a fluorescent whitening agent, and a dye may be added to the core, if necessary. The amount of titanium oxide in the sheath is 0.5
It is necessary to keep the content 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.

In order to obtain a polyamide having an amino terminal group amount of 10 g equivalent / 10 ⁶ g or less as the polymer of the sheath portion, when the polyamide is produced by the melt spinning method,
Triaryloxy-S-triazine was added in an amount of 0.7 to 2.5 times mol% of the amount of amino end groups of polyamide, and the reaction was carried out to adjust the polyamide to have an amount of amino end groups of 10 g equivalent / 10 ⁶ g or less. can do. The triaryloxy-S-triazine used here includes:
As described in JP-B-46-5068, triphenyl-S-cyanurate, tris (p-methyl-phenyl) -S-cyanurate, tris (pt-butyl-phenyl) -S-cyanurate, etc. Can be mentioned.

The amount of triaryloxy-S-triazine added is, as described above, 0.
A suitable amount is 7 to 2.5 times mol%, preferably 0.9 to 2.3 times mol%, and the amount of amino terminal groups of the polyamide is 10 g equivalent / 10 without impairing the spinnability at the addition amount within this range. ⁶
It can be less than or equal to g. The amount of this amino terminal group is 10
If it is not more than g equivalent / 10 ⁶ g, yellowing of the polyamide fiber cannot be prevented.

Further, a benzoxazole-based optical brightening agent is blended in the sheath, and any product may be used as the benzoxazole-based optical brightening agent, 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 0.005 to 0.2% by weight, and preferably 0.01 to 0.1% by weight. If the amount of the fluorescent whitening agent added is less than 0.005% by weight, the effect of improving the whiteness of the fiber and the opacity effect are insufficient, and the light resistance may be poor. is there. If the addition amount is more than 0.2% by weight, not only the whiteness improving effect is saturated but also the fiber tends to yellow, which is not preferable.

In the core-sheath type composite fiber used in the present invention, the core portion and the sheath portion are arranged in a substantially concentric shape, and the volume ratio of the core portion is 6%.
It is preferably 0 to 90%. If it exceeds 90%, the sheath portion may be too thin, and the effect of the fluorescent whitening agent may be difficult to obtain, and good whiteness and light resistance may be difficult to obtain, which is not preferable. Further, if it is less than 60%, the opacity effect tends to decrease, which is not preferable. Furthermore, the preferred core volume ratio is 70-80%
Is. The composite form requires the core and the sheath to be arranged substantially concentrically. The term substantially maximum value of the thickness of the sheath portion are concentric (L _A) and the minimum value (L _B)
The ratio (L _A / L _B ) is less than or equal to 1.5.

A knitted fabric is knitted and woven using the above-mentioned core-sheath composite yarn. 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.

[0017]

When the opaque nylon cloth of the present invention is made to contain a high concentration of titanium oxide in the core portion of the fiber and a polyamide having an amino terminal group amount of 10 g equivalent / 10 ⁶ g or less is arranged in the sheath portion, the core portion is Is protected by the yellowing-preventing polymer resulting from the small amount of amino terminal groups in the sheath while maintaining the whiteness, so that the fiber itself has an effect of preventing yellowing. Moreover, when a small amount of titanium oxide and a benzoxazole-based optical brightening agent are contained in the sheath as in the present invention, the insufficient whiteness of the sheath due to the low concentration of titanium oxide causes a benzoxazole-based optical brightener. To obtain an opaque nylon fabric that has good whiteness, opacity, and light resistance, and also has the above-mentioned anti-yellowing property, by using a benzoxazole-based optical brightener that is kneaded into the sheath. Will be able to.

[0018]

EXAMPLES Next, the method for producing the fabric of the present invention will be described in more detail with reference to the examples. The measurement and evaluation of the performance of the fabrics in the 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) Light resistance In accordance with JIS L-0842, measurement was carried out with a carbon arc fade meter, and the evaluation was relatively made with the naked eye in the following four grades. ◎: Very good ○: Good △: Slightly bad
X: Poor (3) Whiteness The sensory test was used to evaluate the following four levels. ◎: Very good ○: Good △: Slightly bad
×: Poor (4) Yellowing resistance Yellowing due to nitric oxide gas Nitrogen oxide gas fastness was measured according to JIS L-0855, and visually evaluated relative to the following four grades. ◎: Very good ○: Good △: Slightly bad
×: Bad Yellowing due to wrapping paper material A sample was cut into a size of 6 cm × 6 cm, wrapped with commercial foil that was cut into the same size, and wrapped in aluminum foil.
After leaving it at 100 ° C. for 100 hours, a sensory test was conducted to evaluate the following four grades. ◎: Very good ○: Good △: Slightly bad
×: Bad

Example 1 As cores of concentric core-sheath composite fibers, 6% by weight, 8% by weight and 1% of titanium oxide were added to ε-caprolactam, respectively.
3% by weight and 20% by weight were added and the mixture was polymerized by a usual method to obtain an opaque nylon composition having a relative viscosity of sulfuric acid of 2.60. Next, titanium oxide was added to ε-caprolactam for the sheath part 0.4.
% By weight, and using a conventionally known core-sheath composite spinning device, the sheath nylon composition has a relative viscosity of 2.60 and a terminal amino group amount of 62 g equivalent / 10 ⁶ g ε during spinning.
-Caprolactam, triphenyl-S-cyanurate 1.5 wt% and yeast bright OB-1 (benzoxazole-based optical brightener, Eastman Kodak Company)
The core-sheath composite yarn was melt-spun by adding 0.1% by weight and stretched by a usual 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 an inch and a weft density of 81 threads / inch, followed by relaxing and scouring by 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 the purpose of comparison with the present invention, a fabric for comparison (in the same manner as in the present example) except that the amount of titanium oxide in the core portion of the core-sheath composite yarn is 5% by weight in this example ( Comparative example 1) was obtained. Further, 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 8% by weight, the amount of titanium oxide in the sheath was set to 0.4% by weight, and triphenyl- A comparative fabric (Comparative Example 2) was obtained in exactly the same manner as in this Example except that the addition of S-cyanurate was omitted.

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

[0024]

[Table 1]

As is clear from Table 1, the fabric of the present invention is
It can be seen that it has excellent yellowing resistance to both nitric oxide gas and wrapping paper, has excellent opacity, whiteness and light resistance. Further, Comparative Example 1 in which the amount of titanium oxide added to the core was 5% by weight lacked opacity, and Comparative Example 2 in which the addition of triphenyl-S-cyanurate was omitted had no yellowing resistance effect. I understand.

Example 2 In Example 1, the amount of titanium oxide in the core portion was 8% by weight, and the amount of optical brightener in the sheath portion was 0.005% by weight, 0.01% by weight, and 0.00% by weight, respectively. A fabric of the present invention was obtained by the same method as in Example 1 except that the content was 1% by weight and 0.2% by weight.

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% by weight (Comparative Example 3), 0.003% by weight (Comparative Example 4), A comparative fabric was obtained in the same manner as in this example except that the content was 0.3% by weight (Comparative Example 5).

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.

[0029]

[Table 2]

As is clear from Table 2, the fabric of the present invention has excellent yellowing resistance against both nitric oxide gas and wrapping paper material, and has excellent opacity, whiteness and light resistance. It turns out that is also good. Further, it can be seen that when the amount of the optical brightener added is reduced to 0.003% by weight (Comparative Example 4), the whiteness and the light resistance are poor, and the opacity is lacking unless the optical brightener is used.

[0031]

EFFECTS OF THE INVENTION According to the present invention, it has an anti-yellowing property against both wrapping paper material and gas, has excellent opacity and good whiteness, and has excellent light resistance. A nylon fabric 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 portion contains 6 to 20% by weight of titanium oxide, a sheath portion contains 0.5% by weight or less of titanium oxide, and a benzoxazole-based optical brightener contains 0.005 to 0.2% by weight. A core-sheath type nylon composite fiber in which a core part and a sheath part are arranged substantially concentrically, and a polyamide having an amino end group content of 10 g equivalent / 10 ⁶ g or less is used for the sheath part. An opaque nylon fabric characterized by being composed of: