KR102271294B1 - Thermal bonding fiber and thermal bonding fiber composite - Google Patents

Abstract

The present invention has excellent mechanical properties such as strength, elasticity, elongation, etc., can increase process efficiency while preventing fiber damage by lowering the thermal bonding temperature, and is a technology for securing excellent durability by improving adhesive strength, Shore D a core comprising a thermoplastic polyester elastomer resin having a hardness of 55D to 90D; and a sheath formed on the core and comprising a thermoplastic polyester elastomer resin having a Shore D hardness of 20D to 50D and a copolyester resin having a melting temperature of 80°C to 150°C. It relates to fiber composites.

Description

Thermo-adhesive fiber and heat-adhesive fiber composite {THERMAL BONDING FIBER AND THERMAL BONDING FIBER COMPOSITE}

The present invention relates to heat-adhesive fibers and heat-adhesive fiber composites. More specifically, it has excellent mechanical properties such as strength, elasticity, elongation, etc., can increase process efficiency while preventing fiber damage by lowering the thermal bonding temperature, and heat-adhesive fiber and heat-adhesive fiber having excellent durability due to improved adhesive strength It relates to an adhesive fiber composite.

In general, polyester copolymer elastomers prepared by reacting a polyol mixture such as alkylene glycol and polyalkylene glycol oxide with aromatic dicarboxylic acid have excellent physical and chemical properties, flexibility, strength, and electrical insulation properties. It is widely applied to various moldings and wire covering materials.

Recently, research on thermo-adhesive composite fibers that produce monofilaments through thermal bonding, which includes polyester copolymer elastomer as the main components of the core and sheath, and then undergoes a solidification process by melting and cooling by heat, is actively being studied. have.

However, since the polyester copolymer elastomer itself has a high melting temperature exceeding 150 ° C., in order to proceed with thermal bonding between the polyester copolymer elastomers, heat treatment at a high temperature higher than the melting temperature of the polyester copolymer elastomer is essential. There were limits.

Accordingly, there is a demand for the development of a new heat bonding fiber capable of lowering the heat bonding temperature when manufacturing the heat bonding fiber while maintaining the excellent mechanical properties of the existing polyester copolymer elastomer at the same level or higher.

An object of the present invention is to provide a heat-adhesive fiber having improved mechanical properties, such as strength, elasticity, and elongation, and capable of increasing process efficiency while preventing fiber damage by lowering the heat-bonding temperature.

In addition, the present invention is to provide a heat-adhesive fiber composite comprising the heat-adhesive fiber.

In the present specification, a core comprising a thermoplastic polyester elastomer resin having a Shore D hardness of 55D to 90D; and a sheath formed on the core and comprising a thermoplastic polyester elastomer resin having a Shore D hardness of 20D to 50D and a copolyester resin having a melting temperature of 80°C to 150°C.

In the present specification, there is also provided a heat-adhesive fiber composite comprising a heat-adhesive fiber.

Hereinafter, heat-adhesive fibers and heat-adhesive fiber composites according to specific embodiments of the present invention will be described in more detail.

In the present specification, when a part "includes" a certain component, it means that other components may be further included rather than excluding other components unless otherwise stated.

In the present specification, "*" means a bonding point, and specifically, it may be a bonding point between the repeating unit represented by Formula 1 or Formula 2 and another repeating unit.

In this specification, the weight average molecular weight means the weight average molecular weight in terms of polystyrene measured by the GPC method. In the process of measuring the weight average molecular weight in terms of polystyrene measured by the GPC method, a commonly known analyzer and a detector such as a differential refraction detector and a column for analysis may be used, and the temperature generally applied Conditions, solvents, and flow rates can be applied. Specific examples of the measurement conditions include a temperature of 30° C., a chloroform solvent (Chloroform), and a flow rate of 1 mL/min.

In the present specification, the core (Core), the sheath (Sheath) may refer to a sheath-shaped structure that surrounds the core located therein from the outside.

In the present specification, examples of the method for measuring the Shore D (Shore D) hardness are not particularly limited, but may be measured based on the method specified in ASTM D 2240.

In the present specification, examples of the method for measuring the melting temperature, the glass transition temperature, and the crystallization temperature are not particularly limited, but using a DSC measuring device (manufacturer: Mettler Toledo, device name: DSC1, star system), hold at 300 ℃ for 5 minutes and, after cooling to room temperature slowly, a method of measuring by scanning again at a temperature increase rate of 10 °C/min can be used.

In the present specification, the example of the method for measuring the intrinsic viscosity is not particularly limited, for example, after dissolving the measurement target at a concentration of 0.12% in orthochlorophenol (OCP) at 150 ° C., in a constant temperature bath at 35 ° C. A method of measuring using a viscometer can be used.

In the present specification, when a specific compound participates in a chemical reaction, the term 'residue' is included in the result of the chemical reaction and means a certain part or unit derived from the specific compound. For example, each of the 'residue' of the dicarboxylic acid component or the 'residue' of the diol component is derived from a dicarboxylic acid component or a moiety derived from a diol component in a polyester formed by an esterification reaction or a polycondensation reaction. It means the derived part.

According to one embodiment of the invention, a core comprising a thermoplastic polyester elastomer resin having a Shore D hardness of 55D to 90D; and a sheath formed on the core and comprising a thermoplastic polyester elastomer resin having a Shore D hardness of 20D to 50D and a copolyester resin having a melting temperature of 80°C to 150°C may be provided. .

The present inventors use a thermo-adhesive fiber obtained by mixing a copolyester resin having a melting temperature of 80 ° C to 150 ° C with a thermoplastic polyester elastomer resin having a sheath D hardness of 20D to 50D as in the embodiment above, By lowering the melting temperature of the sheath, it was confirmed that thermal bonding between the core and the sheath proceeded at a lower temperature, and the invention was completed.

In particular, the copolyester resin having a melting temperature of 80°C to 150°C can improve initial adhesion with the core while lowering the melting temperature of the sheath through a low melting temperature, as well as excellent hydrolysis resistance Therefore, the durability of the heat-adhesive fiber can be secured because there is little change in adhesive strength even during long-term storage.

In addition, the copolyester resin having a melting temperature of 80 ℃ to 150 ℃ has excellent compatibility with the thermoplastic polyester elastomer resin, so that the mechanical properties of the thermoplastic polyester elastomer when mixed are realized at the same level or higher, while the copolyester resin It is possible to realize the effect of improving durability by

Hereinafter, each component of the heat-adhesive fiber of the embodiment will be described in detail.

core

The core may include a thermoplastic polyester elastomer resin having a Shore D hardness of 55D to 90D. That is, the thermoplastic polyester elastomer resin included in the core may have a relatively higher hardness than the thermoplastic polyester elastomer resin included in the sheath, and thus, the finally manufactured heat-adhesive fiber may have high strength.

The thermoplastic polyester elastomer resin having the Shore D hardness of 55D to 90D may include a repeating unit represented by the following Chemical Formula 1 and a repeating unit represented by the following Chemical Formula 2, respectively.

[Formula 1]

In Formula 1, m is 2 to 6, X is an integer of 1 or more,

[Formula 2]

In Formula 2, n is 2 to 6, p is 10 to 30, and Y is an integer of 1 or more.

Specifically, the repeating unit represented by Formula 1 is an ester repeating unit obtained through an esterification reaction between an aromatic dicarboxylic acid or a derivative thereof and an aliphatic diol, and the repeating unit represented by Formula 2 is an aromatic dicarboxylic acid or a derivative thereof and a polyether It corresponds to an ester repeating unit obtained through an esterification reaction between diols.

Examples of the aromatic dicarboxylic acid or its derivatives include dimethyl terephthalate, dimethyl isophthalate, terephthalic acid, isophthalic acid, and 2,6-naphthadicarboxylic acid. Examples of the aliphatic diol include butanediol or hexanediol. and examples of the polyetherdiol include polyalkylene ether glycol having a weight average molecular weight of 500 g/mol to 2000 g/mol.

Preferably, in Formula 1, m is 4, X is an integer of 1 or more, in Formula 2, n is 4, p is 10 to 30, and Y is an integer of 1 or more.

More specifically, the thermoplastic polyester elastomer resin having the Shore D hardness of 55D to 90D contains less than 12 mol% of the repeating unit represented by Formula 2 based on the entire resin, or 0.1 mol% or more and less than 12 mol%, or 1 It may contain more than 12 mol% by mole%.

That is, based on 100 moles of the thermoplastic polyester elastomer resin having the Shore D hardness of 55D to 90D, the repeating unit represented by Formula 2 is less than 12 moles, or 0.1 moles or more and less than 12 moles, or 1 moles or more and less than 12 moles. can be included as As such, the thermoplastic polyester elastomer resin having the Shore D hardness of 55D to 90D may satisfy high hardness due to a relatively low soft segment ratio derived from polyetherdiol as in the repeating unit represented by Formula 2 above.

sheath

The sheath may include a thermoplastic polyester elastomer resin having a Shore D hardness of 20D to 50D and a copolyester resin having a melting temperature of 80°C to 150°C.

First, the sheath may include a thermoplastic polyester elastomer resin having a Shore D hardness of 20D to 50D. That is, the thermoplastic polyester elastomer resin included in the sheath may have a relatively low hardness compared to the thermoplastic polyester elastomer resin included in the core, and may have a low melting temperature as well as thermal adhesion between the sheath and the core. city efficiency can be improved.

The thermoplastic polyester elastomer resin having the Shore D hardness of 20D to 50D may include a repeating unit represented by the following Chemical Formula 1 and a repeating unit represented by the following Chemical Formula 2, respectively.

[Formula 1]

In Formula 1, m is 2 to 6, X is an integer of 1 or more,

[Formula 2]

In Formula 2, n is 2 to 6, p is 10 to 30, and Y is an integer of 1 or more.

The description of Chemical Formulas 1 and 2 includes the above-described content for the core.

The thermoplastic polyester elastomer resin having the Shore D hardness of 20D to 50D may include 12 mol% or more, or 12 to 30 mol% of the repeating unit represented by Chemical Formula 2 relative to the entire resin.

That is, based on 100 moles of the thermoplastic polyester elastomer resin having the Shore D hardness of 20D to 50D, the repeating unit represented by Formula 2 may be included in an amount of 12 moles or more, or 12 moles to 30 moles. As such, the thermoplastic polyester elastomer resin having the Shore D hardness of 20D to 50D has a relatively high soft segment ratio derived from polyetherdiol as in the repeating unit represented by the formula (2), thereby satisfying low hardness and low melting temperature. .

In addition, the sheath may include a copolyester resin having a melting temperature of 80 °C to 150 °C. As such, when using a heat-adhesive fiber in which a copolyester resin having a melting temperature of 80°C to 150°C is mixed with the aforementioned thermoplastic polyester elastomer resin having a Shore D hardness of 20D to 50D in the sheath, the melting temperature of the sheath is reduced By lowering it, not only can the thermal bonding between the sheaths proceed at a lower temperature, but also the initial adhesive strength with the core can be improved, so that the change in adhesive strength is small even during long-term storage, so that the durability of the heat-adhesive fiber can be secured.

Specifically, the melting temperature of the sheath may be 130 ℃ to 150 ℃. Considering that the melting temperature of the thermoplastic polyester elastomer resin having the Shore D hardness of 20D to 50D is measured to be 155 to 200 °C, only the thermoplastic polyester elastomer resin having the Shore D hardness of 20D to 50D is present in the sheath. In this case, the melting temperature of the sheath is inevitably higher than 155 ℃. However, through blending with the thermoplastic polyester elastomer resin having the Shore D hardness of 20D to 50D and the copolyester resin having a melting temperature of 80 ° C to 150 ° C with excellent compatibility, the melting temperature of the sheath can be lowered to 150 ° C or less. be able to

The copolyester resin having a melting temperature of 80°C to 150°C may include a residue of a diol component including an alicyclic diol or an aliphatic diol; and a residue of a dicarboxylic acid component including an aliphatic dicarboxylic acid or a derivative thereof, an alicyclic dicarboxylic acid or a derivative thereof, an aromatic dicarboxylic acid or a derivative thereof.

Based on the total weight of the copolyester resin, 5 wt% to 40 wt% of the alicyclic diol, 10 wt% to 45 wt% of an aliphatic diol, 5 wt% to 40 wt% of an alicyclic dicarboxylic acid or derivative thereof and an aromatic diol 10% to 45% by weight of carboxylic acid or a derivative thereof.

When the content of the alicyclic dicarboxylic acid or its derivative is less than 5% by weight based on the total weight of the copolyester resin, there is a problem in that sufficient flexibility cannot be secured while replacing the aliphatic acid, and on the contrary, it is more than 40% by weight. In this case, the crystallinity is lowered, and there is a risk that the properties of the original crystalline hot melt resin cannot be exhibited.

When the content of the aromatic dicarboxylic acid or its derivative is less than 10% by weight based on the total weight of the copolyester resin, there is a problem in that crystallinity is lowered, and when it exceeds 45% by weight, there is a problem in that sufficient flexibility cannot be secured. .

If the content of the alicyclic diol is less than 5% by weight based on the total weight of the copolyester resin, there is a risk that hydrolysis resistance may be lowered, and if it exceeds 40% by weight, there is a problem in that flexibility cannot be secured.

If the content of the aliphatic diol is less than 10% by weight based on the total weight of the copolyester resin, there is a problem in that flexibility cannot be secured, and if it is more than 45% by weight, there is a concern that hydrolysis resistance may be lowered.

In addition, based on the total weight of the copolyester resin, 30 wt% to 70 wt% of the aliphatic diol, 5 wt% to 40 wt% of an aliphatic dicarboxylic acid or derivative thereof, and 20 wt% of an aromatic dicarboxylic acid or derivative thereof to 60% by weight.

In the present specification, a derivative refers to a compound in which the structure and properties of the parent, such as introduction of a functional group, oxidation, reduction, substitution of atoms, etc., are changed to the extent that the structure and properties of the parent are not significantly changed using the compound as a parent, specifically, the aliphatic dicarboxylic acid, Examples of derivatives of dicarboxylic acid compounds such as alicyclic dicarboxylic acids or aromatic dicarboxylic acids include dicarboxylic acid ester compounds.

Examples of the aliphatic dicarboxylic acid or a derivative thereof include a linear or branched alkane dicarboxylic acid having 2 to 20 carbon atoms; or a derivative thereof, and specific examples of the linear or branched alkane dicarboxylic acid having 2 to 20 carbon atoms include succinic acid, glutaric acid, adipic acid, pimelic acid, etc., among which adipic acid It is preferable to use

Examples of the alicyclic dicarboxylic acid or its derivative include cycloalkane dicarboxylic acid having 5 to 30 carbon atoms; or a derivative thereof, and as the derivative of the cycloalkane dicarboxylic acid having 5 to 30 carbon atoms, a dialkyl cycloalkane dicarboxylic acid ester having 5 to 30 carbon atoms may be used.

Specific examples of the cycloalkane dicarboxylic acid having 5 to 30 carbon atoms include 1,4-cyclohexanedicarboxylic acid, 1,1-cyclopropanedicarboxylic acid, and 1,2-cyclopentanedicarboxylic acid. Specific examples of the dialkyl cycloalkane dicarboxylic acid ester having 5 to 30 carbon atoms include dimethyl-1,4-cyclohexanedicarboxylate, and among them, dimethyl-1 for economical efficiency and flexibility. Most preferably, ,4-cyclohexanedicarboxylate is used.

Examples of the aromatic dicarboxylic acid or its derivative include arene dicarboxylic acid having 8 to 30 carbon atoms; or a derivative thereof. As the derivative of the arene dicarboxylic acid having 8 to 30 carbon atoms, a dialkyl arene dicarboxylic acid ester having 8 to 30 carbon atoms may be used.

Specific examples of the arene dicarboxylic acid having 8 to 30 carbon atoms include terephthalic acid, isophthalic acid, and 2,6-naphthalenedicarboxylic acid. Specific examples include dimethyl terephthalate and dimethyl isophthalate, of which dimethyl terephthalate or dimethyl isophthalate is preferably used in terms of reaction rate and suppression of side reactions.

Examples of the alicyclic diol include cycloalkane diol having 3 to 20 carbon atoms, and specific examples of the cycloalkane diol having 3 to 20 carbon atoms include 1,4-cyclohexanedimethanol, tricyclodecanedimethanol etc. may be used, and 1,4-cyclohexanedimethanol is preferable in terms of double flexibility.

Examples of the aliphatic diol include a linear or branched alkane diol having 1 to 20 carbon atoms, and specific examples of the linear or branched chain alkane diol having 1 to 20 carbon atoms include butanediol and hexanediol, Double butanediol is most preferred.

The copolyester resin having a melting temperature of 80° C. to 150° C. may have an intrinsic viscosity of 0.2 dl/g to 0.9 dl/g.

In addition, the copolyester resin having a melting temperature of 80 ℃ to 150 ℃ has a glass transition temperature (measured by DSC) of -30 ℃ to 10 ℃, and a crystallization temperature (measured by DSC) is 50 ℃ to 80 ℃ can

An example of a method for producing a copolyester resin having a melting temperature of 80° C. to 150° C. is not particularly limited, and for example, the following method may be used. Alicyclic dicarboxylic acid or derivatives thereof, aromatic dicarboxylic acids or derivatives thereof, cycloaliphatic diols, and aliphatic diols are added as reactants to a reactor in which a column and a condenser are installed, or aliphatic diols or aliphatic dicarboxylic acids as reactants Or a derivative thereof, and an aromatic dicarboxylic acid or derivative thereof, and then gradually increase the temperature of the reactor to reach 130 to 150 ° C., the reaction catalyst is added, and then the reactor temperature is increased to 200 to 270 ° C. The temperature of the column is maintained at 100° C. so that the reactants undergoing the esterification reaction by increasing the temperature do not evaporate or sublimate, so that only the reaction by-products such as water and methanol come out.

When the esterification reaction is carried out for about 1 to 10 hours, the reaction is completed and reaction by-products such as water and methanol are no longer produced, and the reactant in a white slurry state becomes a pale yellow transparent oligomer. The temperature of the oligomer obtained in the esterification reaction is raised to 220 to 300° C., and the pressure is gradually reduced while taking care not to scatter the reactants so that the degree of vacuum becomes 0.01 to 5 torr. In this process, the reaction proceeds for about 30 minutes to 10 hours while removing the diol component flowing out as a reaction by-product.

On the other hand, for example, the mixing ratio between the thermoplastic polyester elastomer resin having a Shore D hardness of 20D to 50D and the copolyester resin having a melting temperature of 80°C to 150°C contained in the sheath, the Shore D hardness is 20D to 50D Based on 100 parts by weight of the thermoplastic polyester elastomer resin, the content of the copolyester resin having a melting temperature of 80° C. to 150° C. may be 10 parts by weight to 50 parts by weight, or 20 parts by weight to 40 parts by weight.

When the content of the copolyester resin having the melting temperature of 80 ℃ to 150 ℃ is excessively reduced, it is difficult to sufficiently realize the effect of reducing the melting temperature and improving the durability by the copolyester resin, and the melting temperature is from 80 ℃ to When the content of the copolyester resin at 150° C. is excessively increased, the tensile properties and elastic properties of the thermoplastic polyester elastomer resin may decrease, thereby reducing mechanical properties of the heat-adhesive fiber.

heat adhesion fiber

The heat-adhesive fiber may include a core including a thermoplastic polyester elastomer resin having a Shore D hardness of 55D to 90D; and a sheath formed on the core and including a thermoplastic polyester elastomer resin having a Shore D hardness of 20D to 50D and a copolyester resin having a melting temperature of 80°C to 150°C. While the sheath is formed on the core, it may adhere to the core to form a fiber having a core-sheath dual structure.

The heat-adhesive fiber may have an average cross-sectional diameter of 100 μm to 500 μm, and the length is not particularly limited. The cross-sectional diameter means the maximum diameter of the cross-sectional shape of the heat-adhesive fiber. In this case, the core may have an average cross-sectional diameter of 80 μm to 400 μm, and the sheath may have an average cross-sectional diameter of 20 μm to 100 μm. The average cross-sectional diameter of the sheath may be obtained by subtracting the average cross-sectional diameter of the core from the average cross-sectional diameter of the entire heat-adhesive fiber.

On the other hand, with respect to 100 parts by weight of the thermoplastic polyester elastomer resin having the Shore D hardness of 55D to 90D, the content of the thermoplastic polyester elastomer resin having the Shore D hardness of 20D to 50D is 1 part by weight to 50 parts by weight, or 10 parts by weight parts to 30 parts by weight. When the content of the thermoplastic polyester elastomer resin having the Shore D hardness of 20D to 50D is excessively increased with respect to 100 parts by weight of the thermoplastic polyester elastomer resin having the Shore D hardness of 55D to 90D, the mechanical properties of the heat-adhesive fiber are can decrease.

The heat-adhesive fiber may be used as a material for chairs, sneakers, curtains, and car mats. More specifically, it can be applied as a mesh material of a mesh chair, an outer skin of a lightweight sports shoe, a curtain material, and the like.

Various additives may be added to the core or sheath of the heat-adhesive fiber to improve physical properties, if necessary. The type of additive, the input method, and the input time are not significantly limited, and various known contents can be applied without limitation, and specific examples of the additive include, impact modifier, antioxidant, compatibilizer, hydrolysis stabilizer, ultraviolet stabilizer, heat stabilizers, color additives and fixatives, flame retardants, or electrically conductive materials for the loss of static electricity, and the like.

Examples of the method for manufacturing the heat-adhesive fiber are not particularly limited, for example, a composite spinning method of various known methods may be used without limitation.

On the other hand, according to another embodiment of the invention, a heat-adhesive fiber composite including the heat-adhesive fiber of the embodiment may be provided.

The content of the heat-adhesive fiber includes all of the content described above in the one embodiment.

The heat-adhesive fiber composite may include a cross-section of heat-adhesive fibers of a porous mesh structure. The heat-adhesive fiber crossover may form a porous mesh structure through crossover between a plurality of heat-adhesive fibers. Specifically, the heat-adhesive fiber crossover may have a mesh diameter of 0.5 mm to 5 mm.

More specifically, in the heat-adhesive fiber intersection, the heat-adhesive fiber may be fused at each intersection. The intersection point means a point where two or more heat-adhesive fibers intersect each other, and as the heat-adhesive fibers are fused at the intersection point, the intersecting heat-adhesive fibers can be adhered to each other.

More specifically, it may be fused to a depth of within 20 μm from the outermost surface of the heat-adhesive fiber. That is, when fusion between the heat-adhesive fibers at the above-mentioned intersection point, each heat-adhesive fiber can form an adhesion through melting and solidification only within 20 μm from the outermost surface.

Considering that the heat-adhesive fiber includes a core and a sheath formed on the core, during fusion between the heat-adhesive fibers at the intersection point, only a portion of the sheath is melted and solidified to form mutual adhesion.

According to the present invention, it has excellent mechanical properties such as strength, elasticity, elongation, etc., can increase process efficiency while preventing fiber damage by lowering the thermal bonding temperature, and heat-adhesive fiber and heat-adhesive fiber having excellent durability due to improved adhesive strength An adhesive fiber composite may be provided.

The invention is described in more detail in the following examples. However, the following examples only illustrate the present invention, and the content of the present invention is not limited by the following examples.

<Preparation Examples 1 to 2: Preparation of thermoplastic polyester elastomer resin>

Preparation Example 1: Polyester Elastomer-I, Shore D Hardness 63D

33 parts by weight of dimethyl terephthalate, 21 parts by weight of 1,4-butanediol, molecular weight in a 75 L pilot polyester polymerization facility equipped with an appropriate stirring device and a facility capable of providing high vacuum to produce polyester with a sufficiently high degree of polymerization After adding an acid component and an alcohol component to a composition of 13 parts by weight of 1000 polytetramethylene ether glycol, 0.12 parts by weight of tetrabutoxytitanium as a condensation polymerization catalyst, and gradually raising the temperature from room temperature to 200 ° C. 0.1 parts by weight of N,N'-hexane-1,3-diylbis-(3-(3,5-di-t-butyl-4-hydroxyphenylpropionamide) as a heat stabilizer, tetrakis[methane-3- (Laurylthio)propionate] After adding 0.1 parts by weight of methane, the temperature was raised to 250 ℃ and vacuum reaction was carried out for several hours.

The thermoplastic polyester elastomer resin obtained in Preparation Example 1 had an intrinsic viscosity of 1.25 dL/g, a glass transition temperature (Tg) of -25 °C, a melting temperature (Tm) of 212 °C, a tensile strength of 440 kg/cm2, an elongation of 500%, and a flexure. The strength was 3,200 kg/cm 2 , and the flame retardancy was UL 94 HB (all specimens burned in the vertical combustion test).

Preparation Example 2: Polyester Elastomer-II, Shore D Hardness 40D

33 parts by weight of dimethyl terephthalate, 8 parts by weight of dimethyl isophthalate, 25 parts by weight of 1,4-butanediol, and 34 parts by weight of polytetramethylene ether glycol having a molecular weight of 1000 were added as ester-forming raw materials. It was carried out under the same conditions as when the polyester elastomer-I was prepared.

The thermoplastic polyester elastomer resin obtained in Preparation Example 2 has an intrinsic viscosity of 1.5 dL/g, a glass transition temperature (Tg) of -30°C, a melting temperature (Tm) of 157°C, a tensile strength of 240 kg/cm2, an elongation of 750%, and a flexure. The strength was 645 kg/cm 2 , and the flame retardancy was UL 94 HB (all specimens burned in the vertical combustion test).

<Preparation Examples 3 to 4: Preparation of copolyester resin>

Preparation Example 3: Copolyester-I

100 g of dimethyl terephthalate, 120 g of dimethyl-1,4-cyclohexanedicarboxylate, 40 g of 1,4-cyclohexanedimethanol, 1,4-butanediol in a reactor equipped with a temperature-controlled column and condenser After adding 120 g, the internal temperature of the reactor was gradually increased to 150° C. while stirring. Then, 0.1 g of tetrabutyl titanate as a catalyst was added thereto, and the temperature was raised to 235° C. while stirring again, and the esterification reaction was continued at this temperature. When methanol started to flow out as a reaction by-product during the reaction, the temperature of the column was maintained at 100° C. so that dicarboxylic acid or dihydric alcohol component did not sublimate or evaporate. When the reaction was continued for about 5 hours, it was confirmed that water and methanol were no longer leaked, and the reaction product was also white and opaque, and a pale yellow transparent oligomer was generated, thereby completing the esterification reaction.

After adding 0.3 g of antimony oxide as a catalyst again to the reactant in the oligomeric state, a vacuum is gradually applied and the temperature is raised, taking care not to scatter the reactant, so that the pressure inside the reactor is maintained at 1 torr, and the temperature of the reactant is 250 ° C. The copolyester resin of Preparation Example 3 was prepared by allowing the reaction to proceed for 2 hours. At this time, 1,4-butanediol, the dihydric alcohol component introduced above, was discharged as a reaction by-product. The copolyester resin thus obtained had an intrinsic viscosity of 0.70 dl/g measured at 30 °C using an Ostwald viscometer, and a glass transition temperature (Tg) measured using a differential scanning calorimeter was 5 °C, and the crystallization temperature ( Tc) was 75 °C, and the melting temperature (Tm) was 125 °C.

Preparation Example 4: Copolyester-II

50 g of dimethyl terephthalate, 30 g of dimethyl isophthalate, 20 g of adipic acid, and 100 g of 1,4-butanediol were added to a reactor equipped with a temperature-controllable column and condenser, and then the internal temperature of the reactor was lowered to 150 while stirring. The temperature was gradually raised to °C.

Hereinafter, the copolyester resin of Preparation Example 4 was prepared by the same method as Preparation Example 3, and the copolyester resin thus obtained had an intrinsic viscosity of 0.73 dl/g measured at 30° C. using an Ostwald viscometer The glass transition temperature (Tg) measured using a differential scanning calorimeter was 0 °C, the crystallization temperature (Tc) was 70 °C, and the melting temperature (Tm) was 115 °C.

<Examples 1 to 2: Preparation of heat-adhesive fiber and heat-adhesive fiber composite>

Example 1

(1) Preparation of heat-adhesive fibers

By using 80 g of the polyester elastomer-I of Preparation Example 1 as a core component, 15 g of the polyester elastomer-II of Preparation Example 2 and 5 g of the copolyester-I of Preparation Example 3 as a cis component, composite spinning Using a spinneret, spinning at a spinning temperature of 275° C. and a winding speed of 1,000 m/min, and stretching 3.3 times at 77° C., and final heat treatment at the heat bonding temperature of Table 1 below to obtain heat-adhesive fibers. The cross-sectional area ratio of the core to the sheath was 80:20 in the finally prepared heat-adhesive fiber, and the cross-sectional diameter was found to be 500 μm.

(2) Preparation of heat-adhesive fiber composites

The heat-adhesive fibers obtained above were arranged to cross each other, and through surface heat bonding between the sheath parts, a porous mesh-structured heat-adhesive fiber composite including a plurality of openings was prepared. At the time of surface thermal bonding, based on a single thermally adhesive fiber, it was fused to a depth within about 20 μm from the surface.

Example 2

The reaction was carried out in the same manner as in Example 1, except that copolyester-II of Preparation Example 4 was used instead of the copolyester-I of Preparation Example 3 as the sheath component, and the heat-adhesive fiber and heat bonding A sex fiber composite was prepared.

<Comparative Example: Preparation of heat-adhesive fiber and heat-adhesive fiber composite>

Comparative Example 1

The reaction was carried out in the same manner as in Example 1, except that 80 g of Polyester Elastomer-I of Preparation Example 1 was used as a core component and 20 g of Polyester Elastomer-II of Preparation Example 2 was used as a sheath component. , to prepare a heat-adhesive fiber and a heat-adhesive fiber composite.

<Experimental Example: Measurement of physical properties of heat-adhesive fibers obtained in Examples and Comparative Examples>

The physical properties of the heat-adhesive fibers obtained in Examples and Comparative Examples were measured in the following manner, and the results are shown in Table 1.

Experimental Example 1: Adhesive strength measurement

According to ASTM D 1876 using the heat-adhesive fibers prepared in Examples and Comparative Examples, a specimen for measurement was made to a width of 15 mm and adhesive strength (Universal Testing Machine, Zwick Roe 11 Z010) using T-peel strength) was measured, and the results are shown in Table 1 below.

Experimental Example Results of Examples and Comparative Examples division core sheath Thermal bonding temperature (℃) Adhesive strength
(g/15mm) Example 1 Preparation Example 1 Preparation Example 2, Preparation Example 3 140 750 Example 2 Preparation Example 1 Preparation Example 2, Preparation Example 4 135 800 Comparative Example 1 Preparation Example 1 Preparation Example 2 155 550

As shown in Table 1, the heat-adhesive fibers prepared in Examples were heat-bonded at a low temperature of 150° C. or less, and the adhesive strength at that time was as high as 700 g/15 mm or more. On the other hand, it can be seen that the heat-adhesive fiber prepared in Comparative Example has a high heat-bonding temperature of 155° C. and a low adhesive strength of 550 g/15 mm.

Therefore, as in the example, when the copolyester is included as the sheath component together with the polyester elastomer, it can be confirmed that the thermal bonding temperature between the core and the sheath is decreased and the adhesive strength is increased at the same time.

Claims (18)

a core comprising a thermoplastic polyester elastomer resin having a Shore D hardness of 55D to 90D; and
It is formed on the core and comprises a sheath including a thermoplastic polyester elastomer resin having a Shore D hardness of 20D to 50D and a copolyester resin having a melting temperature of 80°C to 150°C,
The Shore D hardness of the thermoplastic polyester elastomer resin having a hardness of 20D to 50D is a heat-adhesive fiber having a melting temperature of 155 °C to 200 °C.
According to claim 1,
In the sheath, with respect to 100 parts by weight of the thermoplastic polyester elastomer resin having a Shore D hardness of 20D to 50D, the content of the copolyester resin having a melting temperature of 80°C to 150°C is 10 parts by weight to 50 parts by weight, thermal adhesiveness fiber.
According to claim 1,
The melting temperature of the sheath is 130 ℃ to 150 ℃, heat-adhesive fiber.
According to claim 1,
The copolyester resin having a melting temperature of 80° C. to 150° C. may include a residue of a diol component including an alicyclic diol or an aliphatic diol; and a residue of a dicarboxylic acid component comprising an aliphatic dicarboxylic acid or a derivative thereof, an alicyclic dicarboxylic acid or a derivative thereof, or an aromatic dicarboxylic acid or a derivative thereof.
5. The method of claim 4,
Based on the total weight of the copolyester resin, 5% to 40% by weight of the alicyclic diol, 10% to 45% by weight of an aliphatic diol, 5% to 40% by weight of an alicyclic dicarboxylic acid or a derivative thereof, and an aromatic diol A heat-adhesive fiber comprising 10% to 45% by weight of a carboxylic acid or a derivative thereof.
5. The method of claim 4,
Based on the total weight of the copolyester resin, 30 wt% to 70 wt% of the aliphatic diol, 5 wt% to 40 wt% of an aliphatic dicarboxylic acid or derivative thereof, and 20 wt% to 60 wt% of an aromatic dicarboxylic acid or derivative thereof % by weight of heat-adhesive fibers.
According to claim 1,
The thermoplastic polyester elastomer resin having a Shore D hardness of 55D to 90D and the thermoplastic polyester elastomer resin having a Shore D hardness of 20D to 50D include a repeating unit represented by the following Chemical Formula 1 and a repeating unit represented by the following Chemical Formula 2, respectively made, heat-adhesive fibers:
[Formula 1]

In Formula 1, m is 2 to 6, X is an integer of 1 or more,
[Formula 2]

In Formula 2, n is 2 to 6, p is 10 to 30, and Y is an integer of 1 or more.
8. The method of claim 7,
The thermoplastic polyester elastomer resin having the Shore D hardness of 55D to 90D comprises less than 12 mol% of the repeating unit represented by Formula 2 relative to the total resin, heat-adhesive fiber.
8. The method of claim 7,
The thermoplastic polyester elastomer resin having the Shore D hardness of 20D to 50D is a heat-adhesive fiber comprising 12 mol% or more of the repeating unit represented by Formula 2 relative to the total resin.
According to claim 1,
With respect to 100 parts by weight of the thermoplastic polyester elastomer resin having the Shore D hardness of 55D to 90D, the content of the thermoplastic polyester elastomer resin having the Shore D hardness of 20D to 50D is 1 part by weight to 50 parts by weight, The heat-adhesive fiber.
According to claim 1,
The heat-adhesive fiber, wherein the core has an average cross-sectional diameter of 80 μm to 400 μm, and the sheath has an average cross-sectional diameter of 20 μm to 100 μm.
According to claim 1,
The copolyester resin having a melting temperature of 80 ℃ to 150 ℃ has an intrinsic viscosity of 0.2 dl/g to 0.9 dl/g, heat-adhesive fiber.
According to claim 1,
The copolyester resin having a melting temperature of 80 °C to 150 °C has a glass transition temperature (measured by DSC) of -30 °C to 10 °C, and a crystallization temperature (measured by DSC) of 50 °C to 80 °C, heat adhesive fibers.
According to claim 1,
A heat-adhesive fiber used as a material for chairs, sneakers, curtains, and car mats.
A heat-adhesive fiber composite comprising the heat-adhesive fiber of claim 1 .
16. The method of claim 15,
The heat-adhesive fiber composite comprising a porous mesh structure of heat-adhesive fiber crossover, heat-adhesive fiber composite.
17. The method of claim 16,
In the heat-adhesive fiber crossover, the heat-adhesive fiber is fusion-bonded at each intersection.
18. The method of claim 17,
A heat-adhesive fiber composite, fused to a depth of within 20 μm from the outermost surface of the heat-adhesive fiber.