JP2012219398A - Polyester monofilament for core material for clothes, and manufacturing method for the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polyester monofilament for a core material for clothes, allowing the core material for clothes to have a favorable high Young's modulus and an excellent bending durability as a core material for clothes, and also have characteristics suitable for a molding process owing to a low heat shrinkage ratio.SOLUTION: There is provided a monofilament for a core material for clothes, that comprises a polyester resin composition comprising 5 to 40 wt% of polyethylene naphthalate and 60 to 95 wt% of polyethylene terephthalate, in which a Young's modulus, a dry heat shrinkage ratio at 140°C, and the number of reciprocating bending times required for breaking in MIT bending fatigue test of the monofilament each satisfy a specific number.

Description

  The present invention is a polyester monofilament for clothing core materials, which has a high Young's modulus, toughness, excellent bending durability, low heat shrinkage, and suitable for molding processing, which is not found in conventional polyester monofilaments, and its production It is about the method.

  Clothing such as brassiere, leotard, corset, etc. is designed on the premise that it is used in a form that is in close contact with the body from the viewpoint of beauty or medical treatment. For example, in the case of a brassiere, in order to make the breast look good and beautiful, a metal wire such as stainless steel is inserted as a core material (hereinafter referred to as cup wire) along the lower side of the cup part to make the cup rigid. The breast is fixed from the bottom and is well-shaped.

  In addition, orthodontic garments represented by corsets are formed by inserting a plurality of skeleton cores knitted with metal wires around the upper body with a very strong force.

  Metal cores are perfect in terms of rigidity and fixing power, but they are extremely heavy in clothes that use multiple metal cores like corsets, and they lack flexibility, so that the body shape varies depending on individual differences. It was difficult to deform in accordance with the difference, causing a burden on the body such as compression and tightening.

  Furthermore, there were many anxiety factors in terms of safety and hygiene, such as the risk of protruding from the sewing part and sticking to the body and the occurrence of rust when breakage during metal fatigue due to repeated washing occurred.

  Currently, many examples of using synthetic resin as a material to replace the metal core material have been proposed.

  Examples of the production method include a molded product obtained by melting a resin, pouring it into a mold, and press molding, or a stretch-oriented fibrous product obtained by melt spinning.

  Such a molded product can be manufactured with accurate dimensions and has a high degree of realization of a complicated shape.

  However, because of the non-oriented resin composition in which the resin is hardened, the stress to bending and tension is significantly lower than that of the metal wire. For example, when used as a brassiere cup wire, The current situation is that the rigidity necessary for shape retention is insufficient (see, for example, Patent Document 1).

  As means for solving such a problem, it has been proposed to use an aromatic polyetheretherketone resin having a high flexural rigidity or elastic modulus (see, for example, Patent Document 2). Although it has excellent performance as a resin, it is very expensive and disadvantageous in terms of cost.

  Furthermore, in a molded product, it is difficult to cope with a clothing product having a complicated structure in which the core material itself such as a corset may be woven into a bundle shape, and the range of use is limited.

  On the other hand, the properties of fibrous products obtained from melt spinning can be changed by stretching, heat setting, etc., and compared to molded products, products with higher bending and tensile stress can be realized, but the level is still satisfactory. The current situation is not reached.

  For example, a proposal has been made to use a polyester monofilament having shape memory performance for a brassiere cup wire (see, for example, Patent Document 3), but in this case, drying heat is required during washing in order to return to a reference shape. Moreover, since it is necessary to set a reference shape for each individual, it is difficult to realize industrially.

  As described above, various core materials for clothing using synthetic resins have been proposed as lightweight and safe materials without corrosion, but it is difficult to obtain rigidity and elasticity similar to metals, and there are few examples of adoption. Currently.

JP 2001-131806 A JP 2000-17506 A JP-A-6-173102

  An object of the present invention is a polyester monofilament for clothing core material, which has a high Young's modulus, toughness, excellent bending durability, and has a low heat shrinkage rate and is suitable for molding processing, which is not found in conventional polyester monofilaments. Is to provide.

In order to achieve the above object, according to the present invention, there is provided a polyester monofilament comprising a polyester resin composition comprising 5 to 40% by weight of polyethylene naphthalate and 60 to 95% by weight of polyethylene terephthalate, wherein the following (A) to (C ) Polyester monofilament for clothing core material is provided.
(A) Young's modulus measured in accordance with JIS L1013 is 12000 N / mm ² or more,
(B) Dry heat shrinkage at 140 ° C. is 5.0% or less,
(C) In the MIT bending fatigue test measured according to JIS P-8115, the number of reciprocal bendings until the monofilament is cut is 200 times or more.

  Further, the polyester monofilament for the core material of clothing has a specific heat of 0 ° C. of 0 ° C. when a polyester resin composition comprising 5 to 40% by weight of polyethylene naphthalate and 60 to 95% by weight of polyethylene terephthalate is melt-spun and stretched. .5 cal / g.degree. C. or higher liquid as a heat medium, stretched 5 to 10 times at a temperature in the range of 140 to 175.degree. C., and then stretched monofilament in a dry heat bath at a temperature in the range of 220 to 270.degree. A relaxation heat treatment of 0.80 to 0.98 times is performed.

  According to the present invention, as described below, it has high rigidity and bending durability required for clothing core materials such as brassiere cup wires, as well as use as a core material as a single unit, as well as multiple use. Clothes core material that has the characteristics that it can be easily processed into a knitted body and has a low thermal shrinkage rate, so it has extremely good thermal processing stability, little deformation due to press processing, etc., and also enables complex molding processing Polyester monofilament for use can be obtained.

  Hereinafter, the present invention will be described in more detail.

  The monofilament for clothing core material of the present invention is a polyester monofilament made of a polyester mixed resin composition comprising 5 to 40% by weight of polyethylene naphthalate and 60 to 95% by weight of polyethylene terephthalate.

  Here, polyethylene naphthalate is a polyester having an ethylene-2,6-naphthalate unit as a main repeating unit, and the polyethylene terephthalate is a polyester having an ethylene terephthalate unit as a main repeating unit.

  Part of the 2,6-naphthalenedicarboxylic acid component of the above polyethylene naphthalate is, for example, isophthalic acid, 1,4-cyclohexanedicarboxylic acid, adipic acid, sebacic acid, dimer acid, sulfonic acid metal salt-substituted isophthalic acid, etc. It may be replaced. In addition, a part of the ethylene glycol component is replaced with, for example, propylene glycol, tetramethylene glycol, 1,4-cyclohexanedimethanol, diethylene glycol, neopentyl glycol, 1,4-cyclohexanediol, polyalkylene glycol, and the like. There may be. Furthermore, a small amount of chain branching agents such as pentaerythritol, trimethylolpropane, trimellitic acid, trimesic acid and boric acid can be used in combination.

  On the other hand, the polyethylene terephthalate constituting the polyester resin composition of the present invention is preferably such that 90 mol% or more of the dicarboxylic acid component is composed of terephthalic acid and 90 mol% or more of the glycol component is composed of ethylene glycol.

  In addition, polyethylene terephthalate is obtained by replacing a part of the above terephthalic acid component with, for example, isophthalic acid, 1,4-cyclohexanedicarboxylic acid, adipic acid, sebacic acid, dimer acid, sulfonic acid metal salt-substituted isophthalic acid or the like. May be. In addition, a part of the ethylene glycol component is replaced with, for example, propylene glycol, tetramethylene glycol, 1,4-cyclohexanedimethanol, diethylene glycol, neopentyl glycol, 1,4-cyclohexanediol, polyalkylene glycol, and the like. There may be. Furthermore, a small amount of chain branching agents such as pentaerythritol, trimethylolpropane, trimellitic acid, trimesic acid and boric acid can be used in combination.

  In the present invention, in the range of 5 to 40% by weight of polyethylene naphthalate and 60 to 95% by weight of polyethylene terephthalate, and when the polyester resin composition is melt-spun, the polyester resin composition is supplied to a melt spinning machine, The unstretched yarn discharged from the die after melt-kneading is stretched 5 to 10 times at a temperature in the range of 140 to 175 ° C. using a liquid having a specific heat of 0 ° C. of 0.5 cal / g · ° C. or more as a heat medium, and A production method in which a relaxation heat treatment of 0.80 to 0.98 times is performed in a dry heat bath in a temperature range of 220 to 270 ° C. is employed.

When the polyethylene naphthalate is less than 5% by weight, that is, when the polyethylene terephthalate exceeds 95% by weight, the Young's modulus measured in accordance with JIS L1013-1999 cannot be 12000 N / mm ² or more. A monofilament with insufficient rigidity is not preferable.

  On the other hand, when the proportion of polyethylene naphthalate exceeds 40% by weight and polyethylene terephthalate is less than 60% by weight, the monofilament becomes too stiff, the durability against bending is remarkably lowered, and it becomes brittle. As a result, it becomes an unsuitable characteristic.

  In the case of a brassiere cup wire application that requires rigid and elastic properties, a more preferable result can be obtained when the proportion of polyethylene naphthalate is in the range of 10 to 30% by weight.

  In the present invention, an unprecedented monofilament for a clothing core material having characteristics of high Young's modulus and extremely low heat shrinkage can be obtained by employing the mixing ratio of the resin composition and specific production conditions. Hereinafter, the relationship between manufacturing conditions and quality characteristics will be described.

  Typical examples of the heat source for drawing the undrawn yarn include warm water or water vapor in which water is heated, and polyethylene glycol, glycerin, silicone, and the like, which are high-boiling heat media. The polyester monofilament for clothing core material of the present invention is premised on stretching at 5 to 10 times at a temperature in the range of 140 to 175 ° C. using a liquid having a specific heat of 0 ° C. of 0.5 cal / g · ° C. or more as a heat medium. And In order to satisfy the above-mentioned conditions of hot stretching, a high boiling point heating medium is essential, and polyethylene glycol is preferably used. When stretching is performed using a heat source other than liquid, such as a hot-air circulating furnace or a far-infrared heater furnace, the amount of heat with respect to the monofilament is insufficient, and the necking position called the stretching point becomes unstable, and stable quality can be obtained. It is not preferable because it cannot be done.

  In addition, a liquid having a specific heat of 0 ° C. of 0.5 cal / g · ° C. or more is used as a heating medium, and even if the heating medium temperature is less than 140 ° C. The above-described proper stretching temperature deviates from an industrially unfavorable problem such as troubles such as breakage of the monofilament.

  On the other hand, when the heat medium exceeds 175 ° C., the stretching characteristics of the monofilament are extremely activated, the position of the stretching point is unstable, and the stretching point appears in a place other than the heat medium, so that a stable stretching state is maintained. Is difficult from the industrial viewpoint.

  Under the production conditions in which the draw ratio exceeds 10 times, the polyester monofilament of the present invention deviates from the deformable deformation region regardless of the temperature of the heating medium, and there is no trouble that the monofilament breaks, and there is no trouble of breakage. However, the unreasonable stretching strain remains undesirably because the quality in the fiber axis direction becomes extremely unstable. Furthermore, when the draw ratio is less than 5 times, the Young's modulus cannot be sufficiently improved, and the rigidity as a core material for clothing is insufficient.

  In the heat setting step that passes after the stretching step, it is essential to perform a relaxation heat treatment of 0.80 to 0.98 times in a dry heat bath in a temperature range of 220 to 270 ° C. When the heat treatment temperature is less than 220 ° C., the amount of heat necessary for the relaxation treatment is insufficient and the shrinkage rate is increased, so that the thermal stability of the monofilament is lowered. The same applies when the relaxation magnification exceeds 0.98 times.

  On the other hand, when the heat treatment temperature exceeds 270 ° C., it is close to the melting point of the polyester, so that there is a high possibility that the monofilament is blown out, which is an unsuitable region for production.

  Furthermore, if the relaxation ratio is less than 0.80 times, the tendency to be flexible increases and a monofilament with a high Young's modulus cannot be obtained.

  On the other hand, when a heat source other than a dry heat bath is used in the relaxation heat treatment step, for example, a heat medium such as polyethylene glycol used in the stretching step, it is one of the features of the present invention no matter how the heat treatment temperature and magnification conditions are changed. It is not possible to achieve both high Young's modulus and low shrinkage.

  The polyester monofilament of the present invention preferably has a number of reciprocal bendings required for cutting of 200 or more, as measured with an MIT bending fatigue tester. Furthermore, if it is 5000 times or more, the core material for clothes which can be used for various clothes can be obtained.

  On the other hand, when the number of reciprocal bendings required for cutting is less than 200, it is not preferable to use it as a core material for clothing because the rigidity of the monofilament is remarkably reduced due to repeated deformation during wearing. For example, in the case of corrective clothing such as a corset, there arises a problem that the purpose of correcting the body shape cannot be achieved.

The polyester monofilament of the present invention preferably has a Young's modulus measured in accordance with JIS L1013 of 12000 N / mm ² or more, more preferably 15000 N / mm ² or more, and further preferably 20000 N / mm ² or more. If the Young's modulus is less than the above range, the core material for clothing is insufficient in rigidity, and the support performance along the body shape is insufficient.

  The polyester monofilament of the present invention has any shape such as a circular shape, an elliptical shape, a flat shape, a regular polygon shape, and a polygon shape including an irregular shape, in order to satisfy the use and characteristics of the polyester monofilament. Is also possible. In addition, the flat here means an ellipse or a rectangle, but includes an exact ellipse defined mathematically, an ellipse, a rectangle or a similar shape in addition to a rectangle, and a regular polygon is a mathematical In addition to regular polygons that are defined in general, shapes that are substantially similar to this are included.

  In addition, the diameter of the polyester monofilament of the present invention can be appropriately selected according to the intended use, but as a core material for clothing, it is usually within a range of about 0.8 mm to 2 mm for a round cross section, and an irregular cross section. For example, a rectangle or an ellipse having a maximum length of about 1.5 mm to 3 mm is preferably used.

  The feature of the present invention is that it is unprecedented by prescribing the polyethylene naphthalate content range and stretching and heat setting conditions in melt spinning. A polyester monofilament having excellent performance as a core material can be obtained. Specifically, when the resin composition is in the range of 5 to 40% by weight of polyethylene naphthalate and 60 to 95% by weight of polyethylene terephthalate, and the polyester resin composition is melt-spun, the polyester resin composition is melt-spun. The undrawn yarn discharged from the die after melt-kneading is supplied to a machine, and a liquid having a specific heat of 0 ° C. of 0.5 cal / g · ° C. or more is used as a heat medium at a temperature in the range of 140 to 175 ° C. A production method is used in which the film is stretched and further subjected to a relaxation heat treatment of 0.80 to 0.98 times in a dry heat bath in a temperature range of 220 to 270 ° C.

  Hereinafter, the polyester monofilament for clothing core material of the present invention will be described in detail with reference to examples, but the present invention is not limited to the following examples as long as the gist thereof is not exceeded.

  Further, in the polyester monofilament of the present invention described above and below, the evaluation of the bending fatigue property test, Young's modulus, yarn forming property, etc. of the polyester is measured and evaluated by the following methods.

(1) Flexural fatigue property test According to JIS P-8115, manufactured by Toyo Seiki Co., Ltd .: MIT load resistance tester, load 2.2 cN / dtex, number of bendings 175 times / minute, bending angle 270 degrees (left and right) The average number of times was determined by measuring the number of reciprocal bendings until 10 monofilaments were cut per sample at about 135 degrees.

(2) Young's modulus (N / mm ² )
The Young's modulus was calculated from the initial tensile resistance measured according to JIS2008 L1013 8.10.

(3) Dry heat shrinkage The polyester monofilament was cut into a length of 50 cm, and after heat treatment for 30 minutes in a hot air circulating dryer controlled at 140 ° C. for free, the dimensions were measured and the length contracted. Was expressed as a percentage of shrinkage.

(4) Spinnability (operability): Continuous spinning for 24 hours was performed, and stability in the drawing and relaxation treatment steps was determined according to the following criteria.
○ (Good): There is no thread breakage or loosening failure during yarn production.
X (Bad): The yarn cannot be produced, or the yarn breakage occurs during the yarn production.

[Examples 1-3, Comparative Examples 1-2]
Using two types of dry chips, Toyobo Co., Ltd. PN-640 as the polyethylene naphthalate (hereinafter referred to as PEN) component, and Toray Industries T701T as the polyethylene terephthalate (hereinafter referred to as PET) component, the final polyester resin is used. A polyester resin composition was prepared so that the composition ratio of the composition was a ratio of PEN component: PET component = 25: 75.

  Next, the polyester resin composition is supplied to an extruder spinning machine supply port, kneaded and melted at a spinning machine temperature of 295 ° C., and the molten polyester resin composition is extruded from a spinning nozzle and immediately in warm water at a temperature of 70 ° C. An undrawn yarn that had been cooled and solidified was obtained.

  Subsequently, the unstretched yarn was stretched 6.5 times in a polyethylene glycol (hereinafter referred to as PEG) liquid bath at 150 ° C., and then the PEG adhering to the monofilament surface was washed away in a water washing step. A relaxation heat treatment was performed 0.95 times in a hot air circulating dry heat furnace (hereinafter referred to as a dry heat furnace) at 0 ° C. to obtain a square cross-sectional polyester monofilament having a thickness of 1.6 mm and a width of 3.2 mm.

The obtained polyester monofilament achieved excellent quality characteristics and industrially stable productivity as a core material for clothing in terms of Young's modulus, dry heat shrinkage, and bending fatigue test breakage. The evaluation results are shown in Table 1.
In Examples 2-3 and Comparative Examples 1-2, polyester monofilaments were obtained in the same manner as in Example 1 except that the composition ratio of the final polyester resin composition was changed.

  In Examples 2 to 3, the Young's modulus and flexural fatigue change slightly depending on the increase or decrease of the PEN component, but the properties such as rigidity and bending durability as clothing core materials have sufficient performance as clothing core materials. Yes. On the other hand, in Comparative Example 1, the amount of PEN component is not sufficient, and the Young's modulus is remarkably lowered, resulting in insufficient rigidity, and is not suitable as a core material for clothing.

  Further, in Comparative Example 2, the PEN component is too much, so that the monofilament becomes too rigid, the bending fatigue characteristics are remarkably lowered, and the durability against bending is insufficient, so that it is not suitable as a core material for clothing.

[Example 4, Comparative Examples 3 to 4]
A polyester monofilament was produced in the same manner as in Example 1 except that the stretching temperature was changed as shown in Table 2. In Comparative Examples 3 to 4, the heating medium temperature was not suitable due to stretching, and troubles such as breakage occurred and a monofilament could not be obtained.

[Example 5, Comparative Examples 5-6]
A polyester monofilament was produced in the same manner as in Example 1 except that the draw ratio was changed as shown in Table 2. In Comparative Example 5, the target Young's modulus cannot be obtained because the draw ratio is insufficient. Further, in Comparative Example 6, the draw ratio condition exceeded the deformation region of the monofilament, and a breakage trouble occurred and the monofilament could not be obtained.

[Examples 6-7, Comparative Examples 7-8]
A polyester monofilament was produced in the same manner as in Example 1 except that the relaxation heat treatment temperature was changed as shown in Table 2. In Comparative Example 7, the shrinkage ratio was increased due to insufficient relaxation heat treatment temperature, and the monofilament was insufficient in thermal stability performance. In Comparative Example 8, there was a problem that the monofilament melted and fractured during the relaxation heat treatment, and the monofilament could not be obtained.

[Example 8, Comparative Examples 9 to 10]
A polyester monofilament was produced in the same manner as in Example 1 except that the relaxation heat treatment magnification was changed as shown in Table 2. In Comparative Example 9, since the monofilament tension at the time of relaxation heat treatment was insufficient, a trouble of sagging and breaking occurred, and the monofilament could not be obtained. In Comparative Example 10, since the relaxation ratio was too high, a monofilament having a high shrinkage due to insufficient relaxation treatment and insufficient thermal stability performance was obtained.

  As is clear from the results shown in Tables 1 and 2, the polyester monofilament for clothing core material of the present invention is both rigid and flexible in durability as compared with other assumed production methods (Comparative Examples 1 to 10). Excellent thermal stability and production stability.

  The polyester monofilament for clothing core material of the present invention has high rigidity and bending durability required for clothing core material such as brassiere cup wire, and is used as a core material as a single body and knitted using a plurality of pieces. It has the feature that it can be easily processed into a body. Furthermore, since the thermal shrinkage rate is low, the thermal processing stability is extremely good, the deformation due to press processing etc. is small, and high quality and processing stability are unprecedented for clothing core materials that can be processed even complicatedly. A polyester monofilament that is compatible.

  Compared to metal core materials that have been used as conventional clothing core materials, it achieves an appropriate rigidity and weight reduction, and is hygienic without worrying about rust. .

Claims (2)

A polyester monofilament comprising a polyester resin composition comprising 5 to 40% by weight of polyethylene naphthalate and 60 to 95% by weight of polyethylene terephthalate, wherein the clothes core satisfies the following requirements (A) to (C) Polyester monofilament for materials.
(A) Young's modulus measured in accordance with JIS L1013 is 12000 N / mm ² or more,
(B) Dry heat shrinkage at 140 ° C. is 5.0% or less,
(C) In the MIT bending fatigue test measured according to JIS P-8115, the number of reciprocal bendings until the monofilament is cut is 200 times or more. When melt spinning and stretching a polyester resin composition comprising 5 to 40% by weight of polyethylene naphthalate and 60 to 95% by weight of polyethylene terephthalate, a liquid having a specific heat of 0 ° C. of 0.5 cal / g · ° C. or more is used as a heat medium. Stretching 5 to 10 times at a temperature in the range of ˜175 ° C., and then subjecting the stretched monofilament to a relaxation heat treatment of 0.80 to 0.98 in a dry heat bath at a temperature in the range of 220 to 270 ° C. The manufacturing method of the polyester monofilament for clothing core materials of Claim 1 characterized by these.