KR20160040292A - Elastic monofilament - Google Patents

Abstract

The present invention provides an elastic monofilament excellent in creep resistance after being imparted with resistance to deflection in the bending direction, elasticity, and high temperature. The elastic monofilament of the present invention has a core-sheath composite structure having a diameter of 0.1 to 1.0 mm and a proportion of the core component of 2 to 40% by volume, wherein the core component has a thermoplastic polyester unit in a polymer of 95 to 100 mass Percent thermoplastic elastomer having a hard segment and a soft segment, and a tensile strength of 0.3 to 3.0 cN / dtex.

Description

[0001] ELASTIC MONOFILAMENT [0002]

An object of the present invention is to provide a tire having excellent fatigue resistance against repetitive deformation in the bending direction and being suitable for various industrial uses such as fishery materials, building materials, safety materials, clothing materials, civil engineering materials, agricultural materials, vehicle materials and sports materials, To an elastic monofilament suitable for use in a straight structure having the above structure.

The monofilament using the thermoplastic elastomer is known to have excellent rubber elasticity. The knitted fabric using such a monofilament made of a thermoplastic elastomer has excellent elasticity, and can be suitably used for a clothing material such as stockings, a medical material such as a supporter, Such as sports articles, bedding materials such as beds, and seated materials such as office chairs / car seats. For example, in Patent Documents 1 to 3, it is proposed that a knitted fabric using a thermoplastic elastomer can be suitably used for office chairs and automobile chair applications.

As a monofilament constituting a woven fabric to be applied to such a use, there is known a monofilament made of a thermoplastic elastomer whose main component is polyester or polyether. However, a monofilament made of a monofilament composed of a conventional thermoplastic elastomer, In order to obtain a knitted fabric excellent in mechanical properties and elastic recovery property at the time of repeated deformation, the elastic monofilament is preferably used as the elastic monofilament. (See Patent Documents 2 and 3).

Specifically, Patent Document 2 discloses a sheath (sheath of core-sheath structure) core (core-sheath structure) having an area ratio of the core portion occupying 50% or more in the fiber cross- , An elastic composite monofilament having a melting point of the core component of 150 ° C or more and less than 200 ° C and a melting point of the sheath component of 20 ° C or more and less than 50 ° C lower than the melting point of the core component is used, Melting point component is partially melted or fused to form a fusion point at the intersection of the knitting and weaving structure to improve the binding force so that the knitting structure is less changed at the time of repetitive deformation of the fabric and the long term durability is excellent .

Patent Document 3 discloses a mono-component monofilament using a polymer composed of specific components and having a creep ratio of 5% or less at 80 DEG C for 24 hours under a 15% elongation stress at room temperature, It has been proposed as a monofilament.

In these proposals, it is considered that it is necessary to develop a high rubber elasticity in the elastic monofilament. It is considered that a mono-component monofilament comprising a thermoplastic elastomer (see Patent Document 3) and a core-sheath composite mono-filament comprising two polymers In both of the filaments (see Patent Document 2), the monofilament (both the core and the sheath in the case of the core-sheath composite monofilament) is composed of a thermoplastic elastomer and is supposed to exhibit a rubber elasticity as high as possible.

Japanese Patent Publication No. 9-507782 Japanese Patent Application Laid-Open No. 11-152625 Japanese Patent Application Laid-Open No. 11-172532

However, in the proposals for improving the deflection of the elastic sheet and the like disclosed in the above Patent Documents 2 and 3, resistance to deflection during actual use was still insufficient.

Accordingly, an object of the present invention is to provide an elastic monofilament excellent in anti-sagging property when an elastic sheet or the like is actually used.

The inventors of the present invention have investigated the reason why desired warpage resistance can not be obtained in a knitted fabric obtained from a conventional monofilament. As a result, in the prior art, in order to improve the deflecting property of the knitted fabric, The fatigue resistance of the monofilament is improved and the fatigue resistance of the monofilament is improved by improving the fatigue resistance against repeated deformation of the monofilament in the bending direction under consideration that it is necessary to improve the fatigue resistance against repeated deformation in the monofilament bending direction The present inventors have found that, by adopting the following structure, the deflecting property of the woven fabric can be remarkably improved as compared with the conventional art.

The elastic monofilament of the present invention has a core-sheath composite structure having a diameter of 0.1 to 1.0 mm and a proportion of the core component of 2 to 40% by volume, wherein the core component has a thermoplastic polyester unit in a polymer of 95 to 100 mass %, And the sheath component is a copolymer thermoplastic elastomer having a hard segment and a soft segment, and has a tensile strength of 0.3 to 3.0 cN / dtex.

According to a preferred embodiment of the elastic monofilament of the present invention, the intrinsic viscosity (IV) of the thermoplastic polyester used for the core component is 0.7 or more.

According to a preferred embodiment of the elastic monofilament of the present invention, the hard segment has an aromatic polyester unit as a main constituent unit, the soft segment has an aliphatic polyether unit and / or an aliphatic polyester unit as main constituent units, The aromatic polyester unit is a polybutylene terephthalate unit, and the aliphatic polyether unit and / or aliphatic polyester unit is a poly (tetramethylene oxide) glycol unit.

According to a preferred embodiment of the elastic monofilament of the present invention, the ratio of the hard segment to the soft segment is from 35:65 to 75:25 (by mass ratio).

According to a preferred embodiment of the elastic monofilament of the present invention, the elastic monofilament of the present invention has a bending hardness of 2.0 to 10 cN and is heat-treated for 3 minutes under a temperature condition of 160 DEG C under a constant length, and then subjected to heat treatment under a tension of 0.1 cN / dtex The dimensional change rate when held for 12 hours is 0 to 5%.

According to the present invention, an elastic monofilament excellent in fatigue resistance in the bending direction is obtained. This makes it possible to remarkably improve the deflection resistance of a woven fabric represented by a trampoline, a supporter, a bed, a car seat, and an office chair when actually used.

The elastic monofilament of the present invention is different from the elastic monofilament using only the conventional thermoplastic elastomer in that the thermoplastic polyester having 95 to 100 mass% of the thermoplastic polyester unit in the polymer is disposed in the core component, The core component is burdened by a part of the stress which the filament receives when it is elongated and / or curved. As a result, the elastic monofilament of the present invention is liable to be inhibited from elongational deformation and plastic deformation of the thermoplastic elastomer component even when elongated and / or curved. That is, since the elastic monofilament of the present invention is difficult to sag even when subjected to elongation and / or bending deformation, even if it is used for a woven fabric represented by a trampoline, supporter, bed, car seat and office chair, It is possible to remarkably improve the deflection property.

1 is a schematic side view for explaining a method of measuring deflection amount in the present invention.

The elastic monofilament of the present invention has a core-sheath composite structure having a diameter of 0.1 to 1.0 mm and a proportion of the core component of 2 to 40% by volume, wherein the core component has a thermoplastic polyester unit in a polymer of 95 to 100 mass Percent thermoplastic elastomer having a hard segment and a soft segment, and a tensile strength of 0.3 to 3.0 cN / dtex.

That is, in the elastic monofilament of the present invention, by combining a thermoplastic elastomer having rubber elasticity and a specific thermoplastic polyester resin such as polyethylene terephthalate having no rubber elasticity in a specific configuration, it is possible to improve fatigue resistance against repeated deformation in the bending direction And that the rubber elasticity in the direction of the monofilament tensile direction, which was not intended to deteriorate in the prior art, is lowered to obtain a remarkable effect on deflection while maintaining the elasticity in the bending direction.

The reason why such a remarkable effect is obtained is presumed as follows.

As a typical example of the mode of use of the elastic monofilament of the present invention, an elastic fabric using an elastic monofilament as a weft yarn and a polyethylene terephthalate monofilament as a warp yarn is used as an office chair or a car seat. In this use form, the load at the time of sitting on the elastic fabric is imparted in a substantially vertical direction. At this time, paying attention to the deformation behavior of one elastic monofilament, the elastic monofilament in which the movement of the elastic fabric by the warp against the load in the vertical direction is suppressed is largely deformed in the bending direction. Also, microscopically attention is paid to the bending portion of the elastic monofilament, the elastic monofilament is compressed on the inner side of the bent portion, and the elastic monofilament is expanded on the outer side of the bent portion.

In such a place, in the elastic monofilament using only the conventional thermoplastic elastomer, since the elastic monofilament is largely elongated outside the bend, deformation more than the elastically deformable elongation inherent to the thermoplastic elastomer is generated to cause plastic deformation, It is believed that sagging occurs.

On the other hand, in the same case, in the core-sheath type composite monofilament in which the thermoplastic polyester such as polyethylene terephthalate is used as the core component and the thermoplastic elastomer is arranged in the specific constitution of the sheath component as in the present invention, The component undergoes a certain stress so that the elongational deformation and the plastic deformation of the thermoplastic elastomer component outside the bend are suppressed and the excellent stretchability of the thermoplastic elastomer placed in the sheath component is hardly damaged. Further, by arranging the thermoplastic polyester such as polyethylene terephthalate in the core component, the creep elongation when exposed to the bending deformation for a long time is also suppressed. Thus, it is considered that the knitted fabric using the elastic monofilament of the present invention is hard to sag over a long period of time, and can exhibit excellent elasticity continuously.

In the elastic monofilament of the present invention, it is necessary that the ratio of the core component is in the range of 2 to 40% by volume from the viewpoint of improving the heat-resistant creep property and ensuring the elasticity in the bending direction. When the ratio of the core component is less than 2 vol%, the over-deflection outside the bending due to the core component described above can not be suppressed. When the content of the core component exceeds 40 vol%, the thermoplastic elastomer component becomes too small Therefore, the intended elasticity is hardly expressed. In this respect, the core component is preferably in the range of 3 to 20% by volume, more preferably in the range of 3 to 13% by volume.

In addition, the cross-sectional shape of the elastic monofilament of the present invention may have an irregular cross-sectional shape such as an ellipse, a square, a polygon, and a multi-leaf cross section in addition to the round cross section.

The elastic monofilament of the present invention preferably has a diameter of 1.0 mm or less and 0.7 mm or less. When the diameter is excessively large, the absolute elongation amount outside the bending at the time of bending deformation increases, plastic deformation tends to occur, and it is likely to cause deflection when the woven fabric is made into a woven fabric. In order for the elastic monofilament to exhibit its function, although the lower limit value of the diameter is not originally, when the diameter is excessively fine, the diameter is 0.1 mm or more in that the form of the core-sheath complex form becomes difficult.

Here, the cross-sectional average diameter of the elastic monofilament is represented by L1, the cross-sectional average diameter of the core component is represented by L2, and the cross-sectional average diameter of the core component is calculated from the center of gravity of the cross- When the thickness is Lt, it is preferable that Lt corresponding to an arbitrary line t throughout the outer periphery of the elastic monofilament satisfies the following relationship.

-15 (%)? (Lt-LT) 100 / LT 15 (%)

Here, LT = (L1-L2) / 2.

The average diameters L 1 and L 2 of the cross section represent the diameter of the area equivalent circle. When the above relationship is satisfied, since the thickness of the sheath component maintains a constant thickness over the entire circumference of the elastic monofilament, a region where the amount of the sheath component is small partially occurs or an extremely large portion is not generated, It is difficult to cause problems such as cracking of the sheath component and unevenness of elastic recovery.

Examples of the thermoplastic polyester which can be used for the core component include polybutylene terephthalate, polyethylene terephthalate, polypropylene terephthalate, polyethylene naphthalate and aromatic polyester. From the viewpoint of versatility, heat resistance and high rigidity, Terephthalate is preferably used.

The intrinsic viscosity (IV) of the thermoplastic polyester used in the core component is preferably 0.7 or more, more preferably 1.0 or more. If the intrinsic viscosity (IV) is too low, the load per molecular chain when the core component is subjected to stress tends to increase, so that the possibility of forming the obtained elastic monofilament tends to increase. From the viewpoints of improving the creep property of the obtained elastic monofilament, improving the mechanical properties, and controlling the deformation at the time of bending, the intrinsic viscosity is not originally limited, but the intrinsic viscosity (IV) is preferably 1.4 or less from the viewpoint of melt processability.

In the present invention, the thermoplastic polyester used for the core component is a polymer having 95 to 100 mass% of a thermoplastic polyester unit. Here, the thermoplastic polyester unit refers to a component other than a component having a polyester skeleton and corresponding to a thermoplastic elastomer described later. As the component of the structure other than the thermoplastic polyester unit, if it is less than 5% by mass, a copolymer with a component copolymerizable with the thermoplastic polyester or other thermoplastic polymer capable of blending can be used.

On the other hand, when the amount of the thermoplastic polyester unit is less than 95% by mass, the mechanical properties of the thermoplastic polyester are impaired by copolymerization or blending, resulting in an elastic monofilament which is liable to cause deflection when formed into a woven fabric. Examples of the copolymerizable component include aliphatic dicarboxylic acids such as aromatic dicarboxylic acids such as isophthalic acid and naphthalene dicarboxylic acid, adipic acid, sebacic acid and azelaic acid, diols such as diethylene glycol and 1,4-butanediol A polyfunctional compound, a metal salt of 5-sulfoisophthalic acid, and a phosphorus-containing compound. In the present invention, the thermoplastic polyester constituting the core component contains substantially 100% by mass of a thermoplastic polyester unit , So-called homopolymers.

The thermoplastic polyester to be used for the core component should be in a range that does not impair the effect of the present invention, specifically 5% by mass or less, such as a gloss removing agent such as titanium oxide, calcium carbonate, kaolin and clay, An antioxidant, an anti-heat agent, an anti-oxidation agent, an anti-light agent, an ultraviolet absorber, an antistatic agent and a flame retardant. Among them, titanium oxide is preferably contained in an amount of 0.01 to 1% by mass from the viewpoint of improving the durability of the elastic monofilament.

The thermoplastic elastomer constituting the sheath component of the elastic monofilament of the present invention is required to be a thermoplastic elastomer having a hard segment and a soft segment such as a styrene elastomer, a polyester elastomer, a polyurethane elastomer and a polyamide elastomer . This is because the blend type thermoplastic elastomer typified by an olefin elastomer has insufficient heat resistance and has a problem of delamination at the interface of the sea-island component and the like. The thermoplastic elastomer used in the present invention preferably has a melting point of 150 ° C or higher, particularly 180 ° C or higher, in view of heat resistance and mechanical characteristics.

As the polyester-based elastomer used in the present invention, it is preferable that the hard segment is mainly composed of an aromatic dicarboxylic acid or an ester-forming derivative thereof and an aromatic polyester unit formed from a diol or an ester-forming derivative thereof It is a preferred form.

Specific examples of the aromatic dicarboxylic acid include terephthalic acid, isophthalic acid, phthalic acid, naphthalene-2,6-dicarboxylic acid, naphthalene-2,7-dicarboxylic acid, anthracene dicarboxylic acid, diphenyl- Dicarboxylic acid, diphenoxyethanedicarboxylic acid, 4,4'-diphenyl ether dicarboxylic acid, 5-sulfoisophthalic acid and 3-sulfoisophthalic acid sodium.

In the present invention, the aromatic dicarboxylic acid is mainly used, but if necessary, a part of the aromatic dicarboxylic acid may be substituted with 1,4-cyclohexane dicarboxylic acid, cyclopentane dicarboxylic acid, 4'-dicyclohexyldicarboxylic acid, and alicyclic dicarboxylic acids such as adipic acid, succinic acid, oxalic acid, sebacic acid, dodecanedioic acid and dimeric acid. Also, ester-forming derivatives of dicarboxylic acids, such as lower alkyl esters, aryl esters, carbonic acid esters and acid halides, can of course be used equivalently.

Specific examples of the diol include diols having a molecular weight of 400 or less such as 1,4-butanediol, ethylene glycol, trimethylene glycol, pentamethylene glycol, hexamethylene glycol, neopentyl glycol and decamethylene glycol Cyclohexanedimethanol, 1,4-dicyclohexanedimethanol, tricyclodecanedimethanol and like alicyclic diols, and xylylene glycol, bis (p-hydroxy) diphenyl, bis (p- Bis [4- (2-hydroxyethoxy) phenyl] sulfone, 1,1-bis [ Aromatic diols such as 4- (2-hydroxyethoxy) phenyl] cyclohexane, 4,4'-dihydroxy-p-terphenyl and 4,4'-dihydroxy- Such diols can also be used in the form of ester-forming derivatives, for example acetylenic or alkali metal salts.

These dicarboxylic acids, derivatives thereof, diol components and derivatives thereof may be used in combination of two or more.

Preferred examples of such rigid segments are polybutylene terephthalate units derived from terephthalic acid and / or dimethyl terephthalate and 1,4-butanediol. Also preferred are hard segments comprising polybutylene terephthalate units derived from terephthalic acid and / or dimethyl terephthalate and polybutylene isophthalate units derived from isophthalic acid and / or dimethyl isophthalate and 1,4-butanediol Is used.

The soft segment of the polyester-based elastomer used in the present invention is composed mainly of an aliphatic polyether unit and / or an aliphatic polyester unit. Examples of the aliphatic polyether include poly (ethylene oxide) glycol, poly (propylene oxide) glycol, poly (tetramethylene oxide) glycol, poly (hexamethylene oxide) glycol, copolymers of ethylene oxide and propylene oxide, Ethylene oxide addition polymers of poly (propylene oxide) glycol, and glycol glycols of ethylene oxide and tetrahydrofuran.

Further, examples of the aliphatic polyester include poly (? - caprolactone), polyanthrolactone, polycaprylolactone, polybutylene adipate, and polyethylene adipate. Among these aliphatic polyether and / or aliphatic polyester, the elastic properties of the obtained polyester elastomer include ethylene oxide adducts of poly (tetramethylene oxide) glycol, poly (propylene oxide) glycol, ethylene oxide and tetra Poly (ε-caprolactone), polybutylene adipate, polyethylene adipate, etc. Among these, poly (tetramethylene oxide) glycol is a preferred constituent unit . The number average molecular weight of these soft segments is preferably about 300 to 6000 in the copolymerized state.

In the elastic monofilament of the present invention, the ratio of the hard segment to the soft segment, that is, the copolymerization ratio is preferably in the range of 35:65 to 75:25 (mass ratio). By setting the ratio of the hard segment to the soft segment within the above range, it is possible not only to obtain a thermal property which is hardly pyrolyzed at the time of composite spinning but also to obtain an elastic monofilament excellent in stretchability because the sheath component has moderate elasticity.

Further, in the elastic monofilament of the present invention, if the effect of the present invention is not impaired, the third component may be added to the outside of the sheath component including the thermoplastic elastomer, or the thermoplastic polyester The core component can be placed on the inner side.

In the elastic monofilament of the present invention, the thermoplastic elastomer constituting the sheath component preferably has a Shore D hardness in the range of 30 to 65. [ By setting the Shore D hardness in the above-mentioned range, it is possible to suppress excessive stretching at the time of bending deformation while adjusting the amount of the hard segment which is likely to be plastically deformed.

The thermoplastic elastomer to be used for the sheath component is not particularly limited so long as it does not impair the effect of the present invention, specifically 5% by mass or less. The thermoplastic elastomer can be used as a degreasing agent such as titanium oxide, calcium carbonate, kaolin and clay, An antioxidant, an antistatic agent, an antistatic agent, an antistatic agent, an ultraviolet absorber, an antistatic agent, and a flame retardant agent.

The elastic monofilament of the present invention has a tensile strength in the range of 0.3 to 3.0 cN / dtex, preferably 0.3 to 2.94 cN / dtex, and more preferably 0.5 to 2.5 cN / dtex. When the tensile strength satisfies the above range, it is difficult to cause deterioration in processability due to single yarn or the like in a higher-order processing step such as a straight-line forming step, and the elastic monofilament becomes sufficiently elastic. Especially when the tensile strength exceeds 3.0 cN / dtex, the rigidity of the core-sheath composite monofilament is excessively high and the elasticity in the bending direction is impaired.

The elastic monofilament of the present invention preferably has a bending hardness of 2.0 to 10.0 cN, more preferably 2.5 to 8.0 cN. When the bending hardness is too low, there is a possibility that the elastic monofilament is stretched excessively at the outer side of the bending at the time of bending. On the other hand, when the bending hardness is excessively large, bending deformation hardly occurs, Occurs. From this viewpoint, in order to obtain a monofilament excellent in durability and excellent in elasticity, the bending hardness is preferably in the above range.

The elastic monofilament of the present invention preferably has a dimensional change rate of 0 to 5% when heat treatment is carried out for 3 minutes under a temperature condition of 160 캜 under a constant length and then for 12 hours under a tension of 0.1 cN / dtex. The heat treatment at a temperature of 160 캜 for 3 minutes is a heat treatment with elastic monofilaments as a knitted fabric. The heat treatment is carried out at a temperature of 160 캜 for 3 minutes and then a heat treatment at a rate of 0.1 cN / dtex When the dimensional change ratio when held for 12 hours under the tension satisfies the above range, it can not have an excessive elongation even after heat setting as a product such as a woven fabric, and can have excellent creep characteristics. A more preferable range of the dimensional change ratio when holding for 12 hours under a tension of 0.1 cN / dtex after heat treatment for 3 minutes under a temperature of 160 ° C under a constant length is 0 to 3%.

The elastic monofilament of the present invention preferably has a boiling water shrinkage rate of 3 to 10%. By setting the boiling water shrinkage ratio in the above range, it is possible to obtain a product having excellent dimensional stability at the time of heat application and excellent in durability, which is difficult to be wrinkled even when made into a woven fabric.

The elastic monofilament of the present invention may be used alone, or it may be used a plurality of the elastic monofilaments of the present invention, or the elastic monofilament of the present invention and the filaments of other materials may be used in tandem.

Next, the production method of the elastic monofilament of the present invention will be described in detail, but the production method of the elastic monofilament is not limited thereto.

The elastic monofilament of the present invention can be produced by a core-sheath complex spinning method using a known co-extrusion facility, so that it is possible to produce the elastic monofilament with high productivity and low cost.

That is, the thermoplastic polyester polymer constituting the core component of the core-sheath composite monofilament and the thermoplastic elastomer constituting the sheath component are melted in respective extruders, respectively, and metered by a gear pump and introduced into the composite pack. The two kinds of polymers, which are the core component and the sheath component, introduced into the composite pack are filtered in a pack with a metal nonwoven filter or a metal mesh, and then introduced into the composite detachment, and the core component is released in a form surrounded by the sheath component.

At this time, in order to suppress the hydrolysis of the thermoplastic elastomer and the thermoplastic polyester used for spinning in the spinneret, it is preferable that the water content of the polymer used for spinning is less than 200 ppm by using a vacuum drier or the like . When the moisture content satisfies the above range, complex anomalies are hard to occur and elastic monofilaments having excellent durability are easily obtained.

Further, in the case of imparting functions such as encapsulation, light resistance and antimicrobiality to the elastic monofilaments, a master chip containing a large amount of a desired pigment, an anti-light agent and an antibacterial agent is prepared, and a thermoplastic polyester resin and / or a thermoplastic elastomer They can be blended with the required amount of resin to spin.

Particularly, in the elastic monofilament of the present invention, it is a preferable form to add an anti-light agent to the thermoplastic elastomer resin for the purpose of reducing deterioration due to ultraviolet rays or the like in actual use. As a preferable light-absorbing agent-added master chip for imparting an anti-light agent to the elastic monofilament of the present invention, "HITELEL" (registered trademark) 21UV manufactured by Toray DuPont is exemplified.

The molten monofilament released from the composite detachment is a preferred form from the viewpoint of eliminating the deformation of the molecular structure occurring in the detoning hole by allowing the heating sleeve and / or the heat insulating sleeve disposed immediately below the composite detaching hole to remove the deformation of the molecular structure. It is preferable that the length of the heating cylinder and / or the heat insulating cylinder is in the range of 10 to 150 mm from the viewpoint of the reduction in unevenness in fineness in the longitudinal direction of the obtained elastic monofilament.

The molten monofilament that has passed through the heating cylinder and / or the heat insulating cylinder as needed is cooled in a cooling bath made of water, polyethylene glycol or the like, and then taken in a take-up roll rotating at a desired surface velocity. The temperature of the cooling bath can be changed while checking the roundness and unevenness of the obtained elastic monofilament. The cooling temperature for obtaining the elastic monofilament of the present invention may be in the range of 20 to 80 캜. In addition, the speed of drawing should be such that the cooling and solidification of the molten monofilament is completed in the cooling bath. In order to set the fiber structure of the unstretched fiber to a suitable range for obtaining the elastic monofilament of the present invention, Min. ≪ / RTI >

The unstretched monofilaments taken from the take-up roll are provided to the stretching process after once wound or once wound. In order to obtain the elastic monofilament of the present invention, it is preferable to adopt a multi-stage stretching method of two or more stages in the stretching step in the stretching step. Also, hot water, PEG bath, steam, and dry heat stretching machine can be used for the heating medium at the time of drawing.

With respect to the stretching temperature, in order to obtain the elastic monofilament of the present invention, it is preferable that the stretching temperature of the second stage is set at a melting point of -50 캜 to -10 캜 of the thermoplastic elastomer disposed in the sheath component. It is possible to obtain an elastic monofilament having excellent elasticity even when it is deformed in the bending direction by suppressing the excessive orientation of the thermoplastic elastomer in the stretching step by setting the stretching temperature of the second stage at the above range in which the molecular mobility of the thermoplastic elastomer is extremely high It becomes possible.

The stretched monofilament after stretching is subjected to a relaxation heat treatment. The relaxation magnification is preferably in the range of 0.99 to 0.85 from the viewpoint of securing the elastic restoration property when it is provided for the restraining of the vibration and the repeated bending deformation. The relaxation heat treatment temperature is preferably set to a melting point of -50 캜 to a melting point of -10 캜 of the thermoplastic elastomer disposed in the sheath component, more preferably a melting point of -40 캜 to -10 캜 of the thermoplastic elastomer have. By setting the relaxation heat treatment temperature in the above-mentioned range, the excessive orientation occurring in the sheath component in the stretching process is relaxed while suppressing the thermal fusion between the elastic monofilaments in the heat treatment step, so that even when deformed in the bending direction, Can be obtained.

In the core-sheath resin composition of the present invention, in order to satisfy the above-described tensile strength range of the present invention, it is preferable to set the total draw magnification obtained by multiplying the draw magnification by the relaxation magnification to less than 4.0 times, And may be less than 3.8 times.

The elastic monofilament after the relaxation treatment is wound by a winding machine, but at this time, the winding tension is preferably set to a range of 0.10 cN / dtex or less. By setting the winding tension within the above range, the load on the elastic monofilament upon winding is reduced, and as a result, an elastic monofilament having excellent durability can be obtained. The lower limit of the winding tension is preferably 0.02 cN / dtex or more in order to obtain a winding package applicable for practical use.

Thus, the elastic monofilament of the present invention can be obtained.

The elastic monofilament of the present invention is particularly advantageous in that the elastic monofilament of the present invention is excellent in creep resistance after in-plane deflection, elasticity, and high creep characteristics, particularly in the bending direction, And sports materials, as well as elastic straight structural bodies such as car seats and office chairs which are easily deformed in the bending direction in actual use.

Example

Next, the elastic monofilament of the present invention will be described in more detail by way of examples. The characteristics used in the examples are defined as follows. The number of measurement n was set to 1 when no particular description was made.

[diameter]

The outer diameter of the elastic monofilament was measured at 10 points in the longitudinal direction by using a laser outer diameter measuring instrument manufactured by Anritsu, and the average value of the obtained outer diameter was defined as the diameter.

[Finnish]

Measured according to JIS L1013: 2010 8.3.1 B method.

[Strength, elongation and tensile strength]

Using a Tensilon UTM-4-100 tensile tester manufactured by Orientech, tensile strength of the monofilament was measured at a constant tension clamp spacing of 25 cm in accordance with JIS L1013: 2010 8.5.1, and the number of times of execution Three times average strength and average elongation were determined. Regarding the strength, the average strength was divided by the fineness.

[Diameter of core component and ratio of core component]

The elastic monofilament was cut in the direction perpendicular to the fiber axis and the cut surface was observed with a digital microscope VHX-100F manufactured by Keith Corporation. The diameter of the core component was measured using a digital microscope length measuring tool and the area measurement tool was used (Volume%) of the core component from the cross-sectional area of the obtained elastic monofilament and the cross-sectional area of the core component.

[Melting point]

Using a differential scanning calorimeter type DSC-7 manufactured by Perkin Elmer, 10 mg of the sample was measured at a heating rate of 10 캜 / minute, and the temperature at which the extreme value of the melting endothermic curve obtained was regarded as the melting point.

[Bending hardness]

An elastic monofilament cut at a length of about 4 cm was set under two stainless steel bars having a diameter of 2 mm provided at intervals of 10 mm in the horizontal direction, and elastic monofilaments having a diameter of 1 mm were attached to the elastic monofilaments at the central portions of the two stainless bars, The stainless steel hook was pulled up at a speed of 50 mm / min using a TCM-200 type universal tensile / compression tester manufactured by Minebea Co., Ltd., and the maximum stress generated at this time was regarded as the bending hardness.

[Boiling water shrinkage (boiling))]

And measured according to JIS L1013: 2010 8.18.1 (Method B).

[Intrinsic Viscosity]

To 100 ml of orthochlorophenol in a flask was added 8 g of a sample pulverized in a Willy type pulverizer (filter pore diameter 1 mm) and heat-treated at a temperature of 160 캜 for 10 minutes. After the heat treatment, the flask was cooled in an oil bath for 15 minutes and then the relative viscosity? Of the obtained solution was measured at 25 占 폚 using an Ostwald viscometer. The viscosity was measured according to an approximate formula of intrinsic viscosity = (K1 占?) + K2 The intrinsic viscosity was determined. The constant K1 is 0.0242 and the constant K2 is 0.2634.

[Dimensional change rate after heat treatment]

A yarn sample (elastic monofilament) wound 10 times so that there is no loosening of yarn or gap between yarns was heat treated in a dry heating oven at a temperature of 160 DEG C for 3 minutes on a steel plate of 30 cm in length and then taken out from the dry heat oven, Respectively. Next, the elongation (E ₀ ) of the yarn sample subjected to the heat treatment when a load of 0.1 cN / dtex was applied after a filament length of 25 cm was set in a Tensilon UTM-4-100 type tensile tester manufactured by Orientek, And the elongation (E ₁₂ )% when the sample was allowed to stand for 12 hours under a load of 0.1 cN / dtex, and E ₁₂ -E ₀ was defined as the rate of dimensional change after heat treatment. Number of measurement n = 5, and the average value of these was adopted.

[Evaluation of elasticity]

The elastic monofilament was attached to the commercial badminton rackets with a load of 0.1 cN / dtex for both warp and weft. After the elastic monofilaments were laid, the subject was subjected to five repetitive load-motion exercises with the palm of the hand in the direction perpendicular to the batting face, and scored according to the following criteria. The number of subjects was 10, and the average of 10 scores was used as a result. 3 to 5 were accepted.

5 points: Excellent rubber elasticity

4 points: middle between 3 points and 5 points

3 points: Rubber elasticity

2 points: between 3 points and 1 point

1 point: Hard

[Sheep]

(Hard steel wire SWP-A) having a fixed diameter of 0.6 mm using a bending wear characteristics tester according to JIS L1095: 2008 (Method B), and the one end portion was held in advance, and the reciprocating stroke of the rubber The elastic monofilaments marked with an interval of 200 mm on the outside of the width were placed under two free rollers provided so that the elastic monofilaments were bent at an angle of 55 degrees to the left and right of the rubbing member, And a reciprocating stroke of 25 mm at a speed of 120 reciprocations / minute. The rubbing member was brought into reciprocating contact with the elastic monofilaments 250 times, and then subjected to a load of 24 hours Respectively.

After the treatment, the sample (elastic monofilament) was removed from the bending wear characteristics tester and immediately suspended in the vertical direction with a load (2) of 6 g / mm < 2 > The distance A (mm) of the waterline from the line a connecting the markings to the maximum deformation point was determined for each sample (elastic monofilament 1), and the average value of five measurements was defined as deflection amount.

[Production of copolymer thermoplastic elastomer (A-1)] [

51.9 parts by mass of terephthalic acid, 39.7 parts by mass of 1,4-butanediol, and 47.6 parts by mass of poly (tetramethylene oxide) glycol having a number average molecular weight of about 1,400 were mixed with 0.04 part by mass of titanium tetrabutoxide and mono-n-butyl-monohydroxy tin oxide And 0.02 parts by mass of the seed were charged into a reaction vessel equipped with a helical ribbon type stirring blade and gradually heated from a temperature of 190 캜 to a temperature of 225 캜 for 3 hours to carry out an esterification reaction while flowing out the reaction water out of the system Respectively. To the reaction mixture, 0.2 part by mass of tetra-n-butyl titanate was further added, and 0.05 parts by mass of "Irganox" (trade name) 1098 (hindered phenol-based antioxidant manufactured by Ciba-Geigy) And the pressure in the system was reduced to 27 Pa over 50 minutes, and polymerization was carried out for 1 hour and 50 minutes under the conditions. The resulting polymer was discharged into strands in water, and pellets of a copolymer thermoplastic elastomer (A-1) having a hard / soft ratio of 48/52 (by mass ratio) were obtained by cutting. The melting point of the obtained pellets was 200 占 폚, and Shore hardness D was 47. [

[Production of copolymer thermoplastic elastomer (A-2)] [

32.9 parts by mass of terephthalic acid, 9.6 parts by mass of isophthalic acid, 40.3 parts by mass of 1,4-butanediol and 46.7 parts by mass of poly (tetramethylene oxide) glycol having a number average molecular weight of about 1,400 were mixed with 0.04 parts by mass of titanium tetrabutoxide, And 0.02 parts by mass of butyl-monohydroxy tin oxide were all charged into a reaction vessel equipped with a helical ribbon type stirring vane, heated gradually from a temperature of 190 占 폚 to 225 占 폚 for 3 hours, And the esterification reaction was carried out. To the reaction mixture, 0.15 parts by mass of tetra-n-butyl titanate was further added, and 0.05 parts by mass of "Irganox" (trade name) 1098 (hindered phenol-based antioxidant manufactured by Ciba-Geigy) And the pressure in the system was reduced to 27 Pa over 50 minutes, and polymerization was carried out for 1 hour and 50 minutes under the conditions. The obtained polymer was discharged into strands in water and cut into pellets of a copolymer thermoplastic elastomer (A-2) having a hard / soft ratio of 49/51 (mass ratio). The melting point of the obtained pellets was 160 DEG C and the Shore hardness D was 40. [

(Examples 1 to 6, Comparative Example 2, and Comparative Example 4)

(T-701T manufactured by Toray Industries, Inc.) having a melting point of 257 DEG C, an intrinsic viscosity of 1.21 and a content of titanium oxide of 0.1% by mass as a polymer for core component, which was dried until the water content became less than 100 ppm, 30 mm extruder each having a set temperature of 295 DEG C and a set temperature of 245 DEG C using a copolymer thermoplastic elastomer (A-1) which was dried until the water content became less than 100 ppm as a sheath component polymer, (Diameter) and the core component ratio shown in Table 1 were measured using a gear pump kept at a temperature of 245 DEG C and 295 DEG C respectively, and the temperature was measured at a temperature of 290 DEG C Lt; RTI ID = 0.0 > radial < / RTI > pack. In the composite spin pack, each molten polymer was filtered through a 200-mesh mesh, and then discharged from a core-sheath composite detonator having a hole diameter of 1.5 mm and a number of holes of 10. The extruded filaments were passed through a heat insulating cylinder having a length of 30 mm provided immediately below the spinneret and then passed through a cooling water bath having a temperature of 25 DEG C provided with an air gap of 30 mm, And taken as an unstretched monofilament. The obtained unstretched monofilaments were subjected to stretching at a stretching magnification shown in Table 1 using a hot water bath which was not once wound and heated at a temperature of 90 DEG C, , The second stage stretching was carried out at the magnifications shown in Table 1. [ The monofilaments after stretching were subjected to relaxation heat treatment at the magnifications shown in Table 1, using a drying heat bath which was subsequently heated to the temperature described in Table 1, and wound up with the winding tension described in Table 1 to obtain an elastic monofilament. The properties of the obtained monofilaments are shown in Tables 1 and 2.

In Comparative Example 2, since the ratio of the core component was small, the excessive deflection outside the bending was not able to be suppressed, and the deflection amount was large. In Comparative Example 4, the tensile strength exceeded 3.05 cN / dtex and the elasticity in the bending direction was damaged.

(Example 7)

The same procedure as in Example 1 was carried out except that 97 mass% of the copolymer thermoplastic elastomer (A-1) and 3 mass% of "Hytrel" (registered trademark) 21UV were used as the sheath component polymer. The properties of the obtained monofilaments were as shown in Table 1.

(Example 8, Comparative Example 3, Comparative Example 5)

As in the case of Example 1, except that a polyethylene terephthalate polymer (T-301T manufactured by Toray Industries, Inc.) having a melting point of 257 ° C and an intrinsic viscosity of 0.71 and containing 0.1% by mass of titanium oxide was used as the core component polymer . The properties of the obtained monofilaments are shown in Tables 1 and 2.

In Comparative Example 3 and Comparative Example 5, the tensile strength exceeded 3.05 cN / dtex and the elasticity in the bending direction was damaged.

(Comparative Example 1)

The copolymer thermoplastic elastomer (A-1) was dried until the water content became less than 150 ppm as the polymer for the core component, and the copolymer thermoplastic elastomer (A-2), which was dried until the water content became less than 150 ppm, After melting in a? 30 mm extruder at a set temperature of 250 占 폚 and a? 40 mm extruder at a set temperature of 215 占 폚, a gear pump kept at a temperature of 245 占 폚 and 250 占 폚 was used to maintain the temperature at 250 占 폚 The same procedure as in Example 1 was carried out except that the composite spinning pack was used. Properties of the obtained elastic monofilaments were as shown in Table 2.

As shown in Tables 1 and 2, the elastic monofilament of the present invention was excellent in sag deflection in the bending direction, elasticity, and creep characteristics after application at high temperature.

1: elastic monofilament after bending wear characteristic test
2: Load
a: the line connecting markings
A: The distance (deflection amount) of the waterline from the line a connecting the markings to the maximum deformation point,

Claims (7)

A thermoplastic polyester having a core-sheath composite structure having a diameter of 0.1 to 1.0 mm and a core component ratio of 2 to 40% by volume, the core component being a thermoplastic polyester unit in a polymer of 95 to 100 mass% Wherein the component is a thermoplastic elastomer based on a copolymer having a hard segment and a soft segment and has a tensile strength of 0.3 to 3.0 cN / dtex. The elastic monofilament according to claim 1, wherein the thermoplastic polyester used in the core component has an intrinsic viscosity (IV) of 0.7 or more. The elastic monofilament according to claim 2, wherein the hard segment has an aromatic polyester unit as a main constituent unit and the soft segment has an aliphatic polyether unit and / or an aliphatic polyester unit as a main constituent unit. The elastic monofilament according to claim 3, wherein the aromatic polyester unit is a polybutylene terephthalate unit and the aliphatic polyether unit and / or aliphatic polyester unit is a poly (tetramethylene oxide) glycol unit. 5. The elastic monofilament of any one of claims 1 to 4, wherein the ratio of the hard segment to the soft segment is from 35:65 to 75:25 (by mass). 6. The elastic monofilament according to any one of claims 1 to 5, having a bending hardness of 2.0 to 10 cN. The method according to any one of claims 1 to 6, wherein the dimensional change ratio when held for a period of 12 hours under a tension of 0.1 cN / dtex after heat treatment for 3 minutes under a constant temperature of 160 캜 is 0 to 5% In elastic monofilament.

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