JPH11172532A - Elastic filament excellent in durability and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an elastic filament excellent in physical characteristics and elastic recovery, most suitable as a nonconventional industrial fiber and further excellent in durability, and further to provide a method for producing the elastic fiber. SOLUTION: This elastic fiber consists essentially of a polyester-based elastomer and has >=80% elongation at break, >=0.5 g/de strength at break, >=90% elastic recovery at 80 deg.C after 30% elongation and <=5% creep ratio at 80 deg.C after 24 hr under an elongation stress of 15% elongation at a room temperature. The method for producing the elastic fiber comprises spinning and drawing a polymer in a specific composition to provide a filament, and heat-treating the obtained filament in a constant length or relax state.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to various industrial uses, such as marine products such as various high-elastic ropes, reinforcing materials and nets / nets for various membrane materials, office chairs and automobile chairs, or The present invention relates to an elastic filament excellent in mechanical strength, high elastic properties, and recovery properties, which can be used in the field of textiles and the like, and a method for producing the same.

[0002]

2. Description of the Related Art In recent years, ropes having excellent elastic recovery by utilizing the high elasticity property of an elastic yarn filament, or utilizing such properties as a component of a fabric, and having a moderate elasticity as a fabric, have been developed. Maintaining characteristics and design,
For example, a technology for providing an article having both cushioning properties and design properties as a skin material, which can replace conventional urethane foam in office chairs and automobile chairs, has been developed. . As an example of such a filament, it is known as a prior art that its main component is composed of an elastomer mainly composed of a thermoplastic polymer such as polyester or polyether, but for example, a conventional cushion material such as urethane when used as a fabric. As compared with, the decrease in elastic recovery during repeated deformation is a disadvantage. Such a drawback has made it difficult to fully deploy this material in various industrial applications premised on long-term use, particularly in fields such as automotive chair applications.

[0003]

SUMMARY OF THE INVENTION The present invention focuses on the problems of the prior art, and retains sufficient mechanical characteristics to constitute a fabric for supporting a static load, and is capable of repetitive deformation. An object of the present invention is to provide an elastic filament having excellent elastic recovery characteristics in which such deterioration in characteristics is extremely small.

[0004]

That is, the present invention provides a polyester elastomer having a breaking elongation of at least 80%, a breaking strength of at least 0.5 g / d, and a 30% elongation at 80.degree. An elastic filament having an elongation recovery rate of 90% or more, and a creep rate of 5% or less at 80 ° C. for 24 hours under a 15% elongation stress at room temperature of 5% or less.
This problem is solved by providing an elastic monofilament preferably having a fineness of 200 denier or more. Further, in the present invention, the main component of the fiber is a high melting polyester segment and a molecular weight of 400 to 6
000 is a copolymer consisting of low melting point polymer segments, the melting point of the high melting point polyester segment is 150 ° C or more, and the melting point or softening temperature of the low melting point polymer segment is 80 ° C or less. Wherein the content of the low melting point polymer segment is in the range of 20 to 55% by weight, more preferably the content of the low melting point polymer segment in the polymer is in the range of 40 to 55% by weight. An elastic filament characterized by the following. In the production method according to the present invention, the elastic filament having the above composition is spun, drawn, and then subjected to a fixed length or relaxation heat treatment. Preferably, the relaxation heat treatment is performed at an overfeed rate of 10% or more. Is what you do.

[0005] An object of the present invention is to use a filament, preferably a monofilament, provided as a linear material such as a rope, or an article such as a knitted fabric obtained by using the filament as a main constituent material to reduce a load applied thereto. While having sufficient mechanical strength to support, the above-mentioned excellent properties in the form of a sheet as a fabric obtained by using the elastic properties and its repeated durability not found in conventional polyester and polyamide fibers, and furthermore, using it. To provide cushioning properties. Hereinafter, the present invention will be described in detail.

The filament according to the present invention has a breaking elongation of at least 80%, a breaking strength of at least 0.5 g / d and a recovery rate of elongation at 80 ° C. after 30% elongation of 90%. % Or more, preferably a fineness of 200%.
It is an elastic monofilament having denier or more. That is, if the elongation at break is less than 80%, there arises a problem that proper elastomeric characteristics cannot be exhibited, and it is preferably 100% or more. Further, if the breaking strength is less than 0.5 g / d, there arises a problem that the formed fabric has insufficient strength and cannot withstand a static load. It is preferably 0.8 g / d or more, more preferably 1.5 g / d or more. However, when the fiber strength exceeds 4.0 g / d, the initial load gradient of the fabric rises, which is not preferable in fabric design. 3 at 80 ° C
The elongation recovery rate after 0% elongation is very important from the viewpoint of durability as an elastic material. If it is less than 90%, the elastic properties are reduced due to repeated use and the fabric is slackened, which is also preferable on products. Absent. From such a viewpoint, a preferable elastic recovery rate is 95% or more. 1 at room temperature
Creep rate of 5 hours at 80 ° C and 24 hours under 5% elongation stress is 5
%, The fabric or yarn is sagged with long-term use, the performance is deteriorated, and the quality is not preferable because the product is wrinkled.

In the present invention, the fineness of the fiber is 2
00 denier or more, preferably 4
It is more than 00 denier. If it is less than 200 denier, for example, when used as a sheet material, problems such as fluffing are likely to occur. There is no limit to the upper limit of the thickness, but if it exceeds 5,000 denier, it tends to be uneven in the cross-sectional direction, which is not preferable in terms of mechanical strength.

Here, the most important factor for obtaining the physical properties of the filament is the component of the polymer used. That is, the main component of the polymer constituting the filament of the present invention is a high melting polyester segment and a molecular weight of 4
A copolymer comprising a low-melting polymer segment having a melting point of from 100 to 6000, wherein the high-melting polyester segment has a melting point of 150 ° C. or more, and the low-melting polymer segment has a melting point or softening temperature of 80 ° C. or less. And the content of the low melting polymer segment is 20.
-55% by weight, more preferably 40-55% by weight
It is important that The temperature of the high melting point component is 150 ° C
If it is less than this, durability at high temperatures, in particular, elongation recovery during repeated deformation and creep performance will be poor. Preferably it is 170 degreeC or more. In addition to the high melting point component, the ratio of the low melting point component is important. That is, the molecular weight is 400 to 6000.
20% by weight of low melting point component composed of polymer segment
If it is less than 1, the elongation recovery at the time of repeated deformation is extremely reduced. For applications requiring durability under extremely severe conditions, such as car seats, the content is preferably 40% by weight or more. Further, the content of the low melting point component is preferably 55% by weight or less. If the content exceeds 55% by weight, the morphological stability decreases, and the creep characteristics at high temperatures are adversely affected, particularly. Also, the melting point or softening temperature of the components of the low-melting polyester segment is 80 ° C. or less. However, if this temperature exceeds 80 ° C., there arises a problem that the elastic properties near room temperature, especially its recoverability, decrease. It is.

The polyester block copolymer, which is the main raw material of the filament, is described in more detail. The high-melting-point hard polyester segment component includes, for example, terephthalic acid, isophthalic acid, 1,5-naphthalenedicarboxylic acid, 2,6- Naphthalenedicarboxylic acid, 4,4'-
An aromatic dicarboxylic acid such as diphenyldicarboxylic acid, bis (4-carboxyphenyl) methane, bis (4-carboxyphenyl) sulfone or an ester thereof;

[0010] Ethylene glycol, propylene glycol, tetramethylene glycol, pentamethylene glycol, 2,2-dimethyltrimethylene glycol, hexamethylene glycol, decamethylene glycol, p-
Xylylene glycol, polyester produced from a diol such as cyclohexane dimethanol, or a copolyester using two or more of these dicarboxylic acids or two or more diols,

Polyesters derived from oxy acids such as p- (β-hydroxyethoxy) benzoic acid and esters thereof, polylactones such as polypivalolactone, 1,2-bis (4,4′-dicarboxyphenoxy) Examples thereof include polyether esters produced from aromatic ether dicarboxylic acids such as ethane and the aforementioned diols, and copolyesters obtained by combining the above dicarboxylic acids, oxy acids, and diols.

Examples of the constituent components of the low melting polymer segment having a molecular weight of 400 to 6000 include polyalkylene ether glycols such as poly (ethylene oxide) glycol, poly (propylene oxide) glycol, poly (tetramethylene oxide) glycol, and mixtures thereof. Further, copolymerized polyether glycols obtained by copolymerizing these polyether glycol constituents can be shown. Polyesters prepared from aliphatic dicarboxylic acids having 2 to 12 carbon atoms and aliphatic glycols having 2 to 10 carbon atoms, for example, polyethylene nadipate, polytetramethylene adipate, polyethylene sebacate, polyneopentyl sebacate, poly Examples thereof include tetramethylene dodecane, polytetramethylene azelate, polyhexamethylene azelate, poly-ε-caprolactone, and the like. Further, a polyester polyether copolymer obtained by combining the above polyester and polyether can also be shown. In the polyester block copolymer, the proportion of the low-melting-point polymer component is 20 to 5
5% by weight is preferred.

As a result of further studies by the present inventors, when producing a filament using the above-specified polymer, the filament is spun and drawn appropriately, and then has a substantially low binding force, ie, a constant binding force. It has been found that by performing a heat treatment in a long or relaxed state, preferably by performing a treatment of shrinking by 10% or more from the length immediately after stretching, the elongation recovery during repeated deformation, particularly after repeated deformation, is significantly improved. . Although the reason is not clear, it is presumed that the basic structure of the elastomer formed at the optimum ratio of the low melting point component and the high melting point component is more stabilized by thermal deformation. The heat treatment referred to here may be performed by a device arranged continuously with the drawing, or may be subjected to a process of once winding or a process of forming a fabric or the like and then substantially shrinking the yarn in a fabric state. Is also good. The most important thing is to use a polymer that satisfies the structure specified in this patent.Other than that, uselessly causes a decrease in mechanical properties and not only does not lead to improvement in durability, Surprising is often worse.

[0014]

EXAMPLES The present invention will be described below with reference to examples. (Example) By adjusting the composition ratio of dimethyl terephthalate, 1,4-butanediol, and poly (tetramethylene oxide) of about 1000 as the low melting point component, each of the low melting point components was 15, 24, 35, 43 of the overall composition. , 5
A block copolymer elastomer resin polymerized so as to be 0.60% by weight was used. Therefore, the hard segment component, which is a high melting point component, is a polybutylene terephthalate (PBT) component, and the melting point of a single polymer is 232 ° C. 0.1 m for each polymer
After preliminary drying for 4 hours under an mHG vacuum degree and an atmosphere temperature of 80 ° C., a drying treatment was performed at 120 ° C. for 12 hours under the same vacuum conditions. The dried resin was adjusted to 22.2 g / min per hole of the nozzle by using a spinning machine having a screw-type melt extrusion device. The melting temperature of the extruder and the temperature of the nozzle were adopted based on the temperatures 30 ° C. and 20 ° C. higher than the melting temperatures of the respective copolymers. The state of the spun yarn was stable in all combinations. 50 polymer discharged
between a Nelson-type roller and a take-up roller, which are cooled by passing through a water bath at about 30 ° C., which is installed with an air gap of 20 mm / min. , And subsequently taken up by a Nelson roller set at a speed set by changing the relaxation ratio between slit-type heaters set to a length of 150 ° C., and immediately wound up. Under any conditions, the denier of the final yarn changes due to the difference in the relax ratio, but is about 200%.
A yarn near 0 denier was obtained. Table 1 shows the high elongation characteristics of the yarns obtained under each experimental condition. The durability of the yarn is 80 ℃, 3
The elongation recovery rate with respect to the initial length when 0% elongation deformation is repeated 10 times, and the creep elongation after 24 hours, excluding the initial elongation after applying a load of 15% elongation at 80 ° C., are evaluated. It was to be. It has been found that the filaments provided by the present invention exhibit sufficient durability in any of the measurement items, and that fibers subjected to an appropriate relaxation treatment exhibit more preferable physical properties.

[0015]

[Table 1]

[Evaluation Method] The evaluation method described in the specification and examples of the present invention will be described. (Strength elongation characteristic) Using a Tensilon TM measuring device manufactured by Orientec Co., Ltd., measured a sample length of 100 mm at a strain rate of 100% / min under an atmosphere of 25% temperature and 65% relative humidity, and obtained a strain / stress curve. The breaking strength and elongation were evaluated more. In each measurement, the average value of five measurements was used as the value.

(Elongation recovery rate) A heating tank adjusted to a temperature of 80 ° C. was set in the above-mentioned measuring apparatus, set to a sample length of 100 mm, heated for 2 minutes, and then strained at a strain rate of 100% / min.
% And immediately returned to 0% at the same rate.
Ten seconds after the deformation returned, elongation deformation of up to 30% was applied again at the same strain rate. After repeating this transformation 10 times,
From the series of strain / stress curves recorded, the amount of strain (x%) at which stress starts to be generated by the tenth elongation was determined, and the elongation recovery during repeated deformation was evaluated using the following equation. Elongation recovery rate (%) = 100-x

(Creep ratio) 100 filaments
cm in length, put a load of 1/100 gf of each fineness in a vertical heating type oven set at 80 ° C ± 2 ° C, and leave it for 10 minutes. An interval of 50 cm at the center was marked. Subsequently, the initial load of the fiber was removed, and a load previously calculated so that the fiber was stretched by 15% at room temperature was immediately applied, and the length between the markings immediately after that was measured (L1). After 24 hours with the oven maintained at the above temperature, the length was measured again (L2). The creep rate at a high temperature was determined by the following equation. Creep rate (%) = 100 * (L2-L1) / L1

(Melting Point, Softening Point) The hard segment and the soft segment are the melting point and the softening point when each is used alone. Specifically, it can be evaluated from an endothermic peak obtained at a temperature rising rate of 20 ° C./min using a DSCII type machine manufactured by Perkin Elmer.

From the above results, experiments 2, 3, 4 of the present invention were performed.
It was found that the monofilaments of Nos. 5 and 6 were all excellent in fatigue resistance such as excellent mechanical properties, elongation recovery and creep resistance.

[0021]

According to the present invention, it is possible to provide an elastic filament which has sufficient mechanical properties to support a static load, and has excellent elastic recovery properties with a very small decrease in properties due to repeated deformation. Made it possible.

Claims (5)

[Claims] 1. Elongation at break of at least 80%, elongation at break of at least 0.5 g / d, and elongation recovery after 30% elongation at 80 ° C. of at least 90%, based on a polyester elastomer as a main raw material. 80 at room temperature under 15% elongational stress
An elastic filament having excellent durability, which has a creep rate at 24 ° C. for 24 hours of 5% or less. 2. The durable elastic filament according to claim 1, wherein the filament is a monofilament having a fineness of 200 denier or more. 3. A high-melting polyester segment comprising a high-melting polyester segment and a low-melting polymer segment having a molecular weight of 400 to 6000, wherein the high-melting polyester segment has a melting point of 150 ° C. or higher. 2. The polymer according to claim 1, wherein the polymer segment has a melting point or softening temperature of 80 [deg.] C. or lower, and the content of the low-melting polymer segment is 20 to 55% by weight. Elastic filament. 4. A polymer whose main component is a copolymer comprising a high-melting-point polyester segment and a low-melting-point polymer segment having a molecular weight of 400 to 6000, wherein the high-melting-point polyester segment has a melting point of at least 150 ° C. Spinning and drawing a filament having a melting point or softening temperature of the polymer segment component of 80 ° C. or less and a content of the low-melting polymer segment of 20 to 55% by weight, followed by heat treatment with constant length or relaxation. A method for producing an elastic filament having excellent durability. 5. The filament is drawn by spinning, and then
5. The method for producing a durable elastic filament according to claim 4, wherein the relaxation heat treatment is carried out at an overfeed rate of at least 10%.