JPH07197343A - Polyamide sewing yarn and its production - Google Patents

Abstract

PURPOSE:To obtain polyamide sewing yarns hard to yellowing due to ultraviolet radiation inherent in sunlight and fluorescent lamps, NOx gases in automobile exhaust gases, etc., and lignin and vanillin present in corrugated boards, etc. CONSTITUTION:This polyamide sewing yarn <=0.01mmol/g in the concentration of the amino terminal groups of a polyamide such as nylon 6 or nylon 66 with part of the original amino terminal groups blocked by a triazine derivative. Another version of this polyamide sewing yarn also contains a benzoxazole- based compound.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyamide sewing thread which is resistant to yellowing.

[0002]

2. Description of the Related Art It is well known that, in general, polyamide sewing threads are more likely to cause yellowing than other synthetic fiber sewing threads. The cause of the yellowing is very complicated strictly,
Broadly speaking, yellowing due to sunlight or ultraviolet rays from fluorescent lamps, yellowing due to nitric oxide gas represented by automobile exhaust gas, phenolic antioxidants, especially lignin and vanillin contained in corrugated paper for packaging materials. Yellowing due to

As a method for preventing such yellowing, a method of adding titanium oxide also as a matting agent at the stage of polymerization of polyamide, or a method of dyeing or resin coating as a post-processing has been conventionally performed. However, with the method of adding titanium oxide, the amount of addition is limited, so it is not possible to obtain a satisfactory yellowing prevention effect. Even if dyeing, the effect changes depending on the hue and dye exhaustion amount, and the resin coating is used for sewing thread. Some pigments or fluorescent bleaching agents are applied to the surface of the resin together with the resin, but there are problems that the texture becomes hard and it is difficult to maintain durability due to cracks in the surface resin.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned factors of yellowing and the present situation of countermeasures, and is a polyamide sewing thread capable of preventing yellowing due to factors such as ultraviolet rays, nitric oxide gas and vanillin. And a method for manufacturing the same.

[0005]

Means for Solving the Problems The present invention achieves the above-mentioned object, and provides a polyamide sewing thread characterized by comprising a polyamide having an amino end group end-capped with a triazine derivative. Also, a polyamide sewing thread characterized in that a polyamide chip is dispersed and mixed with 0.5 to 2.5 times mole of a triazine derivative with respect to the amino terminal group concentration of polyamide, melt-spun and drawn, and processed into a thread. The method is the gist.

The present invention will be described in detail below. The polyamide in the present invention refers to one having an amide bond such as nylon 6, nylon 66, nylon 46, etc., and having an amino group and a carboxyl group at the terminal groups, and for example, ring-opening polymerization reaction such as ε-caprolactam or hexa- It is obtained by a polycondensation reaction of a diamine with a dibasic acid such as methylenediamine and adipic acid. In the present invention, examples of the triazine derivative that blocks the amino terminal group of the polyamide include the triazine derivatives represented by the following chemical formulas 1, 2 and 3.

[0007]

[Chemical 1]

[0008]

[Chemical 2]

[0009]

[Chemical 3]

In the above chemical formula, R is hydrogen, halogen or an aliphatic saturated hydrocarbon group, R ₁ , R ₂ and R ₃ are each independently hydrogen or an aliphatic saturated hydrocarbon group, and X ₁ is a hydrogen group or a hydrocarbon. Group, X ₂ is the same as the following chemical formula 4 or X ₁ , R ₄ is a monovalent aromatic nucleus group, R ₅ is an (n + 1) -valent aromatic nucleus group, R ₆ is OH, OR ₄ , XR ₅ (SO ₃・ 1 / mM) _n, alkylamino group _, arylamino group or monovalent hydrocarbon group, n is an integer of 2 to 3, X is O, S, NH, NR ₇ (R ₇ is a monovalent aliphatic group M is an alkali metal, an alkaline earth metal or hydrogen, and m is 1 when M is an alkali metal or hydrogen and 2 when M is an alkaline earth metal.

[0011]

[Chemical 4]

In the polyamide sewing thread of the present invention, the amino end group is blocked with a triazine derivative so that the amino end group has a molecular weight of 0.
It is preferably composed of a polyamide of not more than 01 mmol / g. Even if the amino terminal group is blocked with a triazine derivative, if the amino terminal group exceeds 0.01 mmol / g, a sufficient yellowing preventing effect cannot be obtained.

As a method of blocking the amino terminal group of the polyamide with the triazine derivative, the triazine derivative is made into a powder and is supplied to an extruder together with the chips of the polyamide and dispersed in the molten polyamide for reaction. For example, when powder of triphenylcyanurate, which is one of the triazine derivatives, and nylon 6 chips are supplied to an extruder and melted, triphenylcyanurate reacts with the amino terminal group of nylon 6 to dephenolize it. To block the amino end groups. This method is preferable because it can use ordinary spinning technology and can be added at the time of spinning, not at the polymerization stage, so that a smaller lot can be produced, and cleaning of the polymerization kettle is unnecessary, leading to cost reduction.

The triazine derivative is preferably used in a molar amount of 0.5 to 2.5 times the amino terminal concentration of the polyamide. More preferably, it is 0.7 to 2.0 times mol. When the amount of the triazine derivative used is less than 0.5 times the molar amount of the amino terminal group of the polyamide, the amino terminal blocking is not sufficient and the effect of preventing yellowing is not obtained, which is not preferable. On the other hand, if it exceeds 2.5 times by mole, the amino terminal is sufficiently blocked and a remarkable yellowing preventing effect can be obtained, but the spinning drawability is deteriorated and the strength of the sewing thread is lowered, which is not preferable.

In the present invention, it is preferable to block the amino terminal group with a triazine derivative and to contain a benzoxazole compound in the polyamide. As the benzoxazole-based compound contained in the polyamide, 4-4′-bis (2-benzoxazolyl) stilbene represented by the following chemical formula 5 and 2-5-bis (5-tertiarybutylbenzo represented by the following chemical formula 6) Examples thereof include compounds such as oxazolyl (2)) thiophene. The benzoxazole-based compound may be supplied to the extruder together with the above-mentioned triazine derivative and dispersed in the polyamide chip.

[0016]

[Chemical 5]

[0017]

[Chemical 6]

The content of the benzoxazole compound is
It is preferably 0.01 to 0.10% by weight with respect to the polyamide. More preferably 0.01 to 0.03% by weight
Is. If this content is less than 0.01%, the effect of improving the fluorescent whiteness, which is a characteristic of the benzoxazole-based compound, cannot be sufficiently exerted, and the synergistic effect of improving the whiteness is achieved only by the yellowing prevention effect of the triazine derivative. I can't get it.

To obtain the polyamide sewing thread of the present invention, the triazine derivative is supplied to the extruder together with the polyamide chips by the usual melt spinning drawing method, or when the benzoxazole compound is used in combination, the triazine derivative and the benzo compound are used. The oxazole-based compound is supplied to an extruder together with a polyamide chip, spun and stretched to obtain a polyamide fiber, and then a normal twisted yarn, false twist crimping process, or fluid treatment process may be performed alone or in combination to process a thread. ， The processing method may be selected according to the application of the sewing thread.

[0020]

When the amino end group of the polyamide is blocked by the triazine derivative as in the present invention, a chemically strong bond is formed and the amino end group of the yellowing factor such as ultraviolet rays, nitric oxide gas or vanillin is converted. Prevent the attack of
A yellowing prevention effect can be obtained. In addition, when a benzoxazole-based compound is used in combination, it absorbs ultraviolet rays from sunlight and fluorescent lamps and radiates visible light to the contrary to exhibit whiteness. Can be demonstrated.

[0021]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to Examples. Evaluation of each performance in Examples was carried out by the following methods.

(1) Amino End Group Concentration After weighing 0.5 g of polyamide fiber, the polyamide end fiber was dissolved in 20 ml of m-cresol and titrated with paratoluenesulfonic acid using thymol blue as an indicator to determine the amino end group. It was measured. The end point of the titration was the time when the color changed from yellow to red.

(2) Fineness, Tensile Strength, Elongation Ratio, Elongation Elasticity Ratio, Hot Water Shrinkage Ratio of Sewing Threads were measured according to JIS L1090. The elongation rate and the elongation elastic modulus were measured by Method A, respectively.

(3) Light discoloration According to JIS L0842, discoloration before and after exposure to a 63 ° C. carbon arc lamp for 20 hours was evaluated. (4) Nitrogen oxide gas discoloration It was evaluated according to the method of 8.2 strong test of JIS L0855.

(5) Vanillin discoloration A sewing thread is circularly knitted and cut into a size of 100 × 100 mm, and 2
Place it on a glass plate with a size of 00 × 300 mm, and overlay a corrugated liner (basis weight 300 g / m ² ) according to JIS P3902 with a size of 150 × 250 mm on it, and a size of 200 × 300 mm on it. Glass plates are stacked and a 5 kg weight is placed on top of them, and the temperature is 40 ° C and the humidity is 80
% Thermostatic chamber for 200 hours, and the discoloration before and after that was evaluated according to JISL0801 10 criteria.

EXAMPLE 1 Relative viscosity 2.7 (viscosity measured by Ubbelohde viscometer when 1 g of chips was dissolved in 100 ml of 96% sulfuric acid), 0.30% by weight of titanium oxide having amino end groups of 0.030 mmol / g. 15 parts by weight of 2-methyl-4,6-diphenoxy-S-triazine as a triazine derivative (1.8 times the molar amount of the amino end groups of nylon 6 chips) was mixed and dispersed in 1000 parts by weight of nylon 6 chips and extruded. It is supplied to a ruder and melted, and is spun and drawn at a spinning speed of 800 m / min, a drawing speed of 500 M / min and a draw ratio of 4.0.
A denier 24 filament polyamide fiber was obtained. The obtained polyamide fiber was used with a # 336B high-speed false twisting machine manufactured by Murata Machinery Co., Ltd., false twisting speed was 500 m / min, and false twisting number was 3700.
T / m, false twisting temperature is 192 ° C, false twisting in both twisting directions S and Z is performed, and then false twisting yarns in both twisting directions S and Z are twisted in the twisting direction Z with a twist number of 120 T / m. This was made into a loom by a conventional leaving machine, subjected to boiling water treatment at a bath ratio of 1:20 for 30 minutes, dehydrated and then dried at 60 ° C. for 1 hour to obtain a polyamide sewing thread of the present invention.

Example 2 In Example 1, the amount of 2-methyl-4,6-diphenoxy-S-triazine used as a triazine derivative was 3 parts by weight (0.36 times the amount of amino end groups of nylon 6 chips). A polyamide sewing thread of the present invention was obtained in the same manner as in Example 1 except that the molar amount was changed.

Example 3 Relative viscosity 2.7 (viscosity measured by Ubbelohde viscometer when 1 g of chips was dissolved in 100 ml of 96% sulfuric acid), 0.30% by weight of titanium oxide having 0.030 mmol / g of amino end groups was contained. 15 parts by weight of 2-methyl-4,6-diphenoxy-S-triazine as a triazine derivative in 1000 parts by weight of nylon 6 chip (1.8 times the molar amount relative to the amino end group of nylon 6 chip) and a benzoxazole compound As 4-4'-bis (2-benzoxazolyl)
0.2 parts by weight of stilbene (0.02% by weight with respect to 6 chips of nylon) is mixed and dispersed, supplied to an extruder and melted, spinning speed 800 m / min, drawing speed 50
Spin-drawing was carried out at 0 M / min and a draw ratio of 4.0 to obtain 110 denier 24 filament polyamide fiber. Using a # 336B high-speed false twisting machine manufactured by Murata Kikai Co., Ltd., the obtained polyamide fiber was used for false twisting speed of 500 m / min and false twisting number of 3700 T /
m, false twisting temperature 192 ° C., false twisting in both twisting directions S and Z, and then false twisting yarns in both twisting directions S and Z are twisted in the twisting direction Z with a twist number of 120 T / m. Then, this was made into a loom with a normal leaving machine, subjected to boiling water treatment at a bath ratio of 1:20 for 30 minutes, dehydrated and then dried at 60 ° C. for 1 hour to obtain a polyamide sewing thread of the present invention.

Example 4 Triphenyl cyanurate 15 as a triazine derivative
Parts by weight (1.
4-fold molar amount), 2- as a benzoxazole-based compound
The present invention was carried out in the same manner as in Example 2 except that 0.15 parts by weight of 5-bis (5-tert-butylbenzoxazolyl (2)) thiophene (0.015% by weight with respect to nylon 6 chips) was used. The polyamide sewing thread of was obtained.

Comparative Example 1 In Example 3, 2-methyl-4,6-diphenoxy-S-triazine as a triazine derivative and 4-4'-bis (2-benzoxazolyl) stilbene as a benzoxazole-based compound. A polyamide sewing thread as a comparative example was obtained in the same manner as in Example 3 except that was not used.

Comparative Example 2 A polyamide sewing thread as a comparative example was obtained in the same manner as in Example 3 except that 2-methyl-4,6-diphenoxy-S-triazine as a triazine derivative was not used. . The obtained Examples 1 to 4 and Comparative Examples 1 to 1
Table 1 also shows the properties of the polyamide sewing thread of No. 2.

[0032]

[Table 1]

As is clear from Table 1, the polyamide sewing thread of Example 1 in which the amino terminal group is blocked with a triazine derivative is less discolored by ultraviolet rays, nitric oxide gas or vanillin, and has an excellent effect of preventing yellowing. In Example 2 in which the amount of the triazine derivative used was small, the number of amino terminal groups which were not end-capped was larger than that in Example 1, and therefore the yellowing improvement effect tended to be small. Further, in Examples 3 to 4 in which the triazine derivative and the benzoxazole-based compound were used in combination, a more stable yellowing preventing effect was obtained. Normal Nylon 6 (Comparative Example 1), in which neither the triazine derivative nor the benzoxazole-based compound was used, was liable to yellow.
Comparative Example 2 using only the benzoxazole-based compound had a low degree of yellowing improvement.

[0034]

EFFECT OF THE INVENTION Since the polyamide sewing thread of the present invention blocks the amino terminal group of polyamide with a triazine derivative, it is possible to improve the effect of preventing yellowing and wear resistance even when sewing a material that does not easily yellow. It can be used by taking advantage of the characteristics of polyamide such as elasticity and elasticity. In addition, a more stable yellowing prevention effect can be obtained by using a benzoxazole compound in combination with the triazine derivative.

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Claims (5)

[Claims] 1. A polyamide sewing thread comprising a polyamide having an amino end group end-capped with a triazine derivative. 2. A polyamide sewing thread comprising an end-capped amino terminal group with a triazine derivative and comprising a polyamide having an amino end group concentration of 0.01 mmol / g or less. 3. A polyamide sewing thread, characterized in that a polyamide chip is dispersed and mixed with a triazine derivative in an amount of 0.5 to 2.5 times the polyamide amino terminal group concentration, melt-spun and stretched, and then processed into a thread. Production method. 4. A polyamide having amino end groups endcapped with a triazine derivative, an amino end group concentration of 0.01 mmol / g or less, and containing 0.01 to 0.10% by weight of a benzoxazole compound. Polyamide sewing thread characterized by being 5. A polyamide chip with 0.5 to 2.5 moles of a triazine derivative based on the amino terminal group concentration of the polyamide, and 0.01 to 0.10% by weight of the benzoxazole compound based on the polyamide. A method for producing a polyamide sewing thread, which comprises mixing and dispersing, melt-spinning, and processing the thread.