Biodegradable fiber and biodegradable nonwoven fabric comprising same

Abstract

The present invention provides a biodegradable fiber and a biodegradable nonwoven fabric comprising same, the biodegradable fiber comprising: a core part comprising a biodegradable aliphatic polyester resin; and a sheath part comprising a biodegradable aliphatic-aromatic polyester resin and surrounding the outer circumferential surface of the core part, wherein the biodegradable aliphatic-aromatic polyester resin has a melt index of 25 g / 10 min to 40 g / 10 min as measured under conditions of 190°C and 2.16 kg.

Description

Biodegradable fibers and biodegradable nonwoven fabrics containing the same

[0001] The present invention relates to a biodegradable fiber and a biodegradable nonwoven fabric containing the same.

[0002] With the recent increase in concerns regarding environmental issues, there is a growing demand for solutions to the disposal problems of various household goods, particularly disposable products. Specifically, petroleum-based polymer materials are widely used in the manufacture of various products such as films, fibers, packaging materials, bottles, and containers due to their low cost and excellent processability. However, they have disadvantages: harmful substances are released during incineration when used products reach the end of their lifespan, and depending on the type, it takes hundreds of years for them to completely decompose naturally.

[0003] In order to overcome the limitations of these petroleum-based polymer materials, research on biodegradable resins that decompose within a relatively short period of time is actively underway. As biodegradable resins, polylactic acid (PLA), polybutylene adipate terephthalate (PBAT), and polybutylene succinate (PBS) are being introduced as alternatives.

[0004]

[0005] The present invention provides a biodegradable fiber having excellent biodegradability and enhanced mechanical properties, and a biodegradable nonwoven fabric containing the same.

[0006]

[0007] The biodegradable fiber according to the present invention comprises a core portion comprising a biodegradable aliphatic polyester resin and a sheath portion comprising a biodegradable aliphatic-aromatic polyester resin and surrounding the outer surface of the core portion, wherein the biodegradable aliphatic-aromatic polyester resin may have a melt index of 25 g / 10 min to 40 g / 10 min measured under conditions of 190 ℃ and 2.16 kg.

[0008] In one embodiment of the present invention, the biodegradable aliphatic polyester resin may have a melt index of 5 g / 10 min to 20 g / 10 min measured under the above conditions.

[0009] In one embodiment of the present invention, the degree of crystallization of the biodegradable aliphatic polyester resin measured by differential scanning calorimetry (DSC) may be greater than 30% and up to 60%.

[0010] In one embodiment of the present invention, the biodegradable aliphatic-aromatic polyester resin may have a degree of crystallization of 10% to 30% as measured by a differential scanning calorimeter.

[0011] In one embodiment of the present invention, the weight ratio of the biodegradable aliphatic polyester resin to the biodegradable aliphatic-aromatic polyester resin may be 20:80 to 60:40.

[0012] In one embodiment of the present invention, the tenacity of the biodegradable fiber may be 1.5 gf / d to 5.0 gf / d.

[0013] In one embodiment of the present invention, the average diameter of the biodegradable fiber may be 5 μm to 100 μm.

[0014] The biodegradable nonwoven fabric according to the present invention comprises biodegradable fibers, wherein the biodegradable fibers comprise a core portion and a sheath portion surrounding the outer surface of the core portion, wherein the core portion comprises a biodegradable aliphatic polyester resin, and the sheath portion comprises a biodegradable aliphatic-aromatic polyester resin, and wherein the biodegradable aliphatic-aromatic polyester resin may have a melt index of 25 g / 10 min to 40 g / 10 min when measured under conditions of 190 ℃ and 2.16 kg.

[0015] In one embodiment of the present invention, the biodegradable nonwoven fabric may satisfy all of the following conditions (1) to (3).

[0016] (1) The basis weight of the above biodegradable nonwoven fabric is 15 gsm (Grams per Square Meter) to 40 gsm

[0017] (2) The thickness of the above biodegradable nonwoven fabric is 0.05 mm or more

[0018] (3) The tensile strength of the above biodegradable nonwoven fabric in the MD (Machine Direction) direction is 14 N / 5cm to 50 N / 5cm, and the tensile strength in the CD (Cross Direction) direction is 8 N / 5cm to 30 N / 5cm

[0019] In one embodiment of the present invention, the elongation of the biodegradable nonwoven fabric in the MD direction may be 20% to 80%, and the elongation in the CD direction may be 40% to 90%.

[0020] In one embodiment of the present invention, the degree of stiffness of the biodegradable nonwoven fabric in the MD direction may be 60 mm or less, and the degree of stiffness in the CD direction may be 45 mm or less.

[0021] In one embodiment of the present invention, the biodegradable nonwoven fabric may be a spunbond nonwoven fabric.

[0022]

[0023] The biodegradable fiber according to the present invention comprises a biodegradable resin. Accordingly, the nonwoven fabric comprising the biodegradable fiber is capable of natural biodegradation, thereby having the effect of not requiring incineration or emitting harmful substances.

[0024] In addition, the biodegradable fiber and nonwoven fabric according to the present invention can have flexibility and improved strength by including a heterogeneous biodegradable resin in a core-sheath form.

[0025] In addition, the biodegradable fiber and nonwoven fabric according to the present invention include a core-sheath structure, and by controlling the melt index of the aliphatic-aromatic polyester resin disposed in the sheath portion, the tensile strength, elongation, and stiffness can be improved.

[0026] In addition, the biodegradable fibers and nonwoven fabrics according to the present invention can have a soft touch and can be applied to various molded products that can be used on the human body.

[0027]

[0028] FIG. 1 is a drawing illustrating a biodegradable fiber according to one embodiment of the present invention.

[0029] FIG. 2 is a cross-section of a biodegradable fiber according to one embodiment of the present invention.

[0030] FIG. 3 is a cross-sectional view of a biodegradable sanitary product according to one embodiment of the present invention.

[0031] FIG. 4 is a drawing showing the upper part of a biodegradable sanitary product according to one embodiment of the present invention.

[0032]

[0033] The structural or functional descriptions of the embodiments disclosed in this specification or application are merely illustrative for the purpose of explaining embodiments according to the technical concept of the present invention. Embodiments according to the technical concept of the present invention may be implemented in various forms other than those disclosed in this specification or application, and the technical concept of the present invention is not to be interpreted as being limited to the embodiments described in this specification or application.

[0034] Furthermore, when a component is described as "comprising" in this specification or application, this means that, unless specifically stated otherwise, it does not exclude other components but may include additional components. Additionally, all numerical ranges representing physical properties, dimensions, etc., of components described in this specification or application should be understood to be modified by the term "approximately" in all cases, unless otherwise specifically stated.

[0035] Additionally, 'ppm' in this specification or application refers to a weight basis.

[0036] Additionally, in this specification or application, 'origin' means a component, structure, or the substance itself derived from a certain substance.

[0037]

[0038] FIG. 1 is a drawing illustrating a biodegradable fiber according to one embodiment of the present invention. FIG. 2 is a drawing illustrating one cross-section of a biodegradable fiber according to one embodiment of the present invention.

[0039] Referring to FIGS. 1 and 2, the biodegradable fiber (10) according to the present invention may include a core portion (12) comprising a biodegradable aliphatic polyester resin. The biodegradable fiber (10) may include a sheath portion (13) that surrounds the outer surface of the core portion and comprises a biodegradable aliphatic-aromatic polyester resin.

[0040] The core portion (12) may have a shape that extends in one direction. The core portion (12) may have a cylindrical shape that extends continuously in the one direction.

[0041] The sheath portion (13) can be in close contact with the outer surface of the core portion (12). The sheath portion (13) can cover the entire outer surface of the core portion (12).

[0042] The diameter (D) of the core portion (12) may be about 1 μm to about 100 μm, about 1 μm to about 90 μm, about 1 μm to about 80 μm, or about 1 μm to about 50 μm.

[0043] The thickness (T) of the sheath portion (13) may be about 0.5 μm to about 100 μm, about 1 μm to about 100 μm, about 1 μm to about 80 μm, or about 1 μm to about 50 μm.

[0044] The above biodegradable aliphatic polyester resin and the above biodegradable aliphatic-aromatic polyester resin may have different physical properties. The above biodegradable aliphatic-aromatic polyester resin may have more tackiness than the above biodegradable aliphatic polyester resin. The above biodegradable aliphatic-aromatic polyester resin may be more flexible than the above biodegradable aliphatic polyester resin. The above biodegradable aliphatic-aromatic polyester resin may have lower crystallinity than the above biodegradable aliphatic polyester resin. The above biodegradable aliphatic polyester resin may have greater mechanical strength than the above biodegradable aliphatic-aromatic polyester resin.

[0045] Accordingly, the biodegradable fiber (10) can have flexibility and improved mechanical strength.

[0046] The above biodegradable aliphatic polyester resin may have a crystallization temperature measured by differential scanning calorimetry (DSC) of 100 ℃ to 150 ℃, 100 ℃ to 140 ℃, 100 ℃ to 130 ℃, or 100 ℃ to 110 ℃.

[0047] The above biodegradable aliphatic polyester resin may have a degree of crystallization measured by the above differential scanning calorimeter of more than 30% to 60%, 35% to 60%, 35% to 55%, or 40% to 55%.

[0048] The above biodegradable aliphatic polyester resin may have a glass transition temperature measured by the above differential scanning calorimeter of 50 ℃ to 70 ℃, 50 ℃ to 68 ℃, 52 ℃ to 68 ℃, or 55 ℃ to 68 ℃.

[0049] The above biodegradable aliphatic polyester resin may have a melting point measured by the above differential scanning calorimeter of 150 ℃ to 190 ℃, 150 ℃ to 185 ℃, 150 ℃ to 180 ℃, or 160 ℃ to 180 ℃.

[0050] The above biodegradable aliphatic polyester resin may have a melt index of 5 g / 10 min to 20 g / 10 min, 6 g / 10 min to 20 g / 10 min, 6 g / 10 min to 18 g / 10 min, or 6 g / 10 min to 15 g / 10 min when measured under conditions of 190 ℃ and 2.16 kg.

[0051] The above biodegradable aliphatic polyester resin may have a melt index of 10 g / 10min to 30 g / 10min, 15 g / 10min to 30 g / 10min, 20 g / 10min to 30 g / 10min, or 20 g / 10min to 25 g / 10min when measured under conditions of 210 ℃ and 2.16 kg.

[0052] If the above range is satisfied, the biodegradable aliphatic polyester resin can be easily spun and its mechanical strength can be improved.

[0053] The above biodegradable aliphatic polyester resin may contain polylactic acid. The above biodegradable aliphatic polyester resin may contain only polylactic acid.

[0054] The above polylactic acid may be a high-melting-point polylactic acid having stereocomplex crystals. Additionally, the above polylactic acid may be formed by solution mixing or melt mixing of poly L-lactic acid and poly D-lactic acid.

[0055] The above polylactic acid may include a unit represented by the following chemical formula 1.

[0056] [Chemical Formula 1]

[0057]

[0058] The above polylactic acid may be a polymer comprising L-lactic acid units and / or D-lactic acid units. The above polylactic acid may include poly L-lactic acid and / or poly D-lactic acid.

[0059] The above poly L-lactic acid may be a polymer mainly comprising L-lactic acid units. The above poly L-lactic acid may contain L-lactic acid units in an amount of about 90 mol% to about 100 mol%, about 95 mol% to about 100 mol%, or about 97 mol% to about 100 mol%. The above poly L-lactic acid may contain D-lactic acid units and / or units other than lactic acid. The above poly L-lactic acid may contain the D-lactic acid units and / or units other than lactic acid in an amount of about 0 mol% to about 10 mol%, about 0 mol% to about 5 mol%, or about 0 mol% to about 3 mol%.

[0060] The above poly D-lactic acid may be a polymer mainly comprising D-lactic acid units. The above poly D-lactic acid may contain the D-lactic acid units in an amount of about 90 mol% to about 100 mol%, about 95 mol% to about 100 mol%, or about 97 mol% to about 100 mol%. The above poly D-lactic acid may contain the L-lactic acid units and / or units other than lactic acid. The above poly D-lactic acid may contain the L-lactic acid units and / or units other than lactic acid in an amount of about 0 mol% to about 10 mol%, about 0 mol% to about 5 mol%, or about 0 mol% to about 3 mol%.

[0061] The unit other than the above lactic acid may be a unit derived from a dicarboxylic acid, polyhydric alcohol, hydroxycarboxylic acid, lactone, etc., having two or more functional groups capable of forming ester bonds, and a unit derived from various polyesters, various polyethers, various polycarbonates, etc. composed of these various components.

[0062] Examples of the above dicarboxylic acids include succinic acid, adipic acid, azelaic acid, sebacic acid, terephthalic acid, isophthalic acid, etc. Examples of the above polyhydric alcohols include aliphatic polyhydric alcohols such as ethylene glycol, propylene glycol, butanediol, pentanediol, hexanediol, octanediol, glycerin, sorbitan, neopentyl glycol, diethylene glycol, triethylene glycol, polyethylene glycol, and polypropylene glycol, or aromatic polyhydric alcohols such as bisphenol to which ethylene oxide has been added.

[0063] Examples of the above hydroxycarboxylic acids include glycolic acid, hydroxybutyric acid, etc. Examples of lactones include glycolide, ε-caprolactone glycolide, ε-caprolactone, β-propiolactone, δ-butyrolactone, β- or γ-butyrolactone, pivalolactone, δ-valerolactone, etc.

[0064] The above biodegradable aliphatic-aromatic polyester resin may include a diol-derived unit, an aromatic dicarboxylic acid-derived unit, and an aliphatic dicarboxylic acid-derived unit.

[0065] The above diol may be an aliphatic diol. The above diol may be a bio-derived diol. The above diols are ethanediol, 1,2-propanediol, 1,3-propanediol, 2-methyl-1,3-propanediol, 2,2-dimethyl-1,3-propanediol, 2,2-diethyl-1,3-propanediol, 2-ethyl-2-isobutyl-1,3-propanediol, 1,2-butanediol, 1,4-butanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 2,2,4-trimethyl-1,3-pentanediol, 1,6-hexanediol, 2-ethyl-1,3-hexanediol, 2,4-dimethyl-2-ethyl-1,3-hexanediol, 2,2,4-trimethyl-1,6-hexanediol, 2-methyl-1,8-octanediol, At least one may be selected from the group consisting of 1,9-nonanediol, 1,10-decanediol and 1,12-octadecanediol or derivatives thereof.

[0066] The above diol may be selected from at least one group consisting of 1,4-butanediol, 1,2-ethanediol, 1,3-propanediol, diethylene glycol, neopentyl glycol, or derivatives thereof.

[0067] The above diol may be selected from at least one group consisting of 1,4-butanediol, 1,2-ethanediol, 1,3-propanediol, or derivatives thereof.

[0068] The above diol may include 1,4-butanediol or a derivative thereof.

[0069] The above aliphatic dicarboxylic acid may be selected from at least one group consisting of oxalic acid, malonic acid, succinic acid, maleic acid, fumaric acid, glutaric acid, adipic acid, pimelodic acid, serve acid, azelaic acid, sebacic acid, dodecanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, or derivatives thereof.

[0070] The above aliphatic dicarboxylic acid may be selected from at least one of the group consisting of adipic acid, succinic acid, sebacic acid, or derivatives thereof.

[0071] The above aliphatic dicarboxylic acid may include adipic acid or a derivative thereof.

[0072] The above aromatic dicarboxylic acid may be selected from at least one group consisting of phthalic acid, terephthalic acid, isophthalic acid, 1,4-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 1,8-naphthalenedicarboxylic acid, 4,4'-diphenyldicarboxylic acid, 4,4'-diphenyletherdicarboxylic acid, anthracenedicarboxylic acid, phenanthrenedicarboxylic acid, or derivatives thereof.

[0073] The above aromatic dicarboxylic acid may be selected from at least one of the group consisting of terephthalic acid, dimethyl terephthalate, 2,6-naphthalene dicarboxylic acid, isophthalic acid, or derivatives thereof.

[0074] The above aromatic dicarboxylic acid may include terephthalic acid, dimethyl terephthalate, or derivatives thereof.

[0075] In the above biodegradable aliphatic-aromatic polyester resin, the molar ratio of the total diol-derived unit including the diol and the total dicarboxylic acid-derived unit including the aromatic dicarboxylic acid and the aliphatic dicarboxylic acid may be about 1:0.9 to about 1:1.1, or about 1:0.95 to about 1:1.05.

[0076] In the above biodegradable aliphatic-aromatic polyester resin, the molar ratio of the aromatic dicarboxylic acid-derived unit and the aliphatic dicarboxylic acid-derived unit may be about 1:1 to about 1.3:1, about 1:1 to about 1.25:1, about 1:1 to about 1.22:1, or about 1:1 to about 1.2:1.

[0077] The above biodegradable aliphatic-aromatic polyester resin may contain diol-derived units derived from 1,4-butanediol in an amount of about 90 mol% or more, about 95 mol% or more, or about 98 mol% or more based on the total diol.

[0078] The above biodegradable aliphatic-aromatic polyester resin may contain aromatic dicarboxylic acid-derived units derived from terephthalic acid or dimethyl terephthalate in an amount of about 30 mol% to about 70 mol%, about 35 mol% to about 65 mol%, about 40 mol% to about 60 mol%, or about 43 mol% to about 53 mol% based on the total dicarboxylic acid.

[0079] The above biodegradable aliphatic-aromatic polyester resin may contain aliphatic dicarboxylic acid-derived units derived from adipic acid in an amount of about 30 mol% to about 70 mol%, about 35 mol% to about 65 mol%, about 40 mol% to about 60 mol%, or about 47 mol% to about 57 mol% based on the total dicarboxylic acid.

[0080] The above-mentioned biodegradable aliphatic-aromatic polyester resin may comprise a first block and a second block. The above-mentioned biodegradable aliphatic-aromatic polyester resin may have a molecular structure in which the first block and the second block are alternately bonded.

[0081] The first block may include the diol-derived unit and the aromatic dicarboxylic acid-derived unit. The first block may be formed by an esterification reaction of the diol and the aromatic dicarboxylic acid. The first block may include only the diol-derived unit and the aromatic dicarboxylic acid-derived unit. The first block may include only repeating units formed by an esterification reaction of the diol and the aromatic dicarboxylic acid. The first block may refer to the sum of the repeating units of the diol and the aromatic dicarboxylic acid prior to the aliphatic dicarboxylic acid bonding.

[0082] The second block may include the diol-derived unit and the aliphatic dicarboxylic acid-derived unit. The second block may be formed by an esterification reaction of the diol and the aliphatic dicarboxylic acid. The second block may include only the diol-derived unit and the aliphatic dicarboxylic acid-derived unit. The second block may include only repeating units formed by an esterification reaction of the diol and the aliphatic dicarboxylic acid. The second block may refer to the sum of the repeating units of the diol and the aliphatic dicarboxylic acid prior to being bonded to the aromatic dicarboxylic acid.

[0083] In the above biodegradable aliphatic-aromatic polyester resin, the ratio (X / Y) of the number of the first block (X) and the number of the second block (Y) may be about 0.5 to about 1.5, about 0.6 to about 1.4, about 0.7 to about 1.3, about 0.75 to about 1.2, or about 0.8 to about 1. The number of the first block may be smaller than the number of the second block.

[0084] The number of the first blocks may be about 30 to about 300, about 40 to about 250, about 50 to about 220, about 60 to about 200, about 70 to about 200, or about 75 to about 200.

[0085] The number of the first blocks may vary depending on the content of the aromatic dicarboxylic acid, the number average molecular weight of the biodegradable aliphatic-aromatic polyester resin, and the degree of substitution described below.

[0086] The number of the second blocks may be about 30 to about 300, about 40 to about 250, about 50 to about 220, about 60 to about 200, about 70 to about 200, or about 75 to about 200.

[0087] The number of the second blocks may vary depending on the content of the aliphatic dicarboxylic acid, the molecular weight of the biodegradable aliphatic-aromatic polyester resin, and the degree of substitution described below.

[0088] When the above-mentioned biodegradable aliphatic-aromatic polyester resin comprises the first block and the second block within the above range, the biodegradable aliphatic-aromatic polyester resin comprising the above-mentioned biodegradable aliphatic-aromatic polyester resin may have appropriate biodegradability and improved mechanical properties.

[0089] The above biodegradable aliphatic-aromatic polyester resin may include the following bonding structures 1 to 3.

[0090] [Coupling Structure 1]

[0091] - Aromatic dicarboxylic acid - Diol - Aliphatic dicarboxylic acid -

[0092] [Combination Structure 2]

[0093] - Aromatic dicarboxylic acid - Diol - Aromatic dicarboxylic acid -

[0094] [Combination Structure 3]

[0095] - Aliphatic dicarboxylic acid - Diol - Aliphatic dicarboxylic acid -

[0096] The diol included in the above bonding structure 1 is bonded between the aromatic dicarboxylic acid and the aliphatic dicarboxylic acid, and to the aromatic dicarboxylic acid and the aliphatic dicarboxylic acid. The diol included in the above bonding structure 1 can be directly esterified bonded between the aromatic dicarboxylic acid and the aliphatic dicarboxylic acid, and to the aromatic dicarboxylic acid and the aliphatic dicarboxylic acid.

[0097] The diol included in the above bonding structure 2 is bonded between the aromatic dicarboxylic acid and the aromatic dicarboxylic acid, and to the aromatic dicarboxylic acid and the aromatic dicarboxylic acid. The diol included in the above bonding structure 2 can be directly esterified bonded between the aromatic dicarboxylic acid and the aromatic dicarboxylic acid, and to the aromatic dicarboxylic acid and the aromatic dicarboxylic acid.

[0098] The diol included in the above bonding structure 3 is bonded between the aliphatic dicarboxylic acid and the aliphatic dicarboxylic acid, and to the aliphatic dicarboxylic acid and the aliphatic dicarboxylic acid. The diol included in the above bonding structure 3 can be directly esterified bonded between the aliphatic dicarboxylic acid and the aliphatic dicarboxylic acid, and to the aliphatic dicarboxylic acid and the aliphatic dicarboxylic acid.

[0099] The above biodegradable aliphatic-aromatic polyester resin may have an alternating ratio.

[0100] The above replacement ratio is the ratio of the diol bonded between the aromatic dicarboxylic acid and the aliphatic dicarboxylic acid among the above diols. That is, the above replacement ratio may be the ratio of the diol included in the bonding structure 1 among the above diols. The above replacement ratio may be a value obtained by dividing the number of moles of the diol included in the bonding structure 1 by the sum of the number of moles of the diol included in the bonding structure 1, the number of moles of the diol included in the bonding structure 2, and the number of moles of the diol included in the bonding structure 3.

[0101] The above replacement ratio may be the ratio of the diol in which the heterocyclic acid is bonded between the diols among the total diols.

[0102] The above-mentioned alternation ratio can be calculated using the following formula 1.

[0103] [Formula 1]

[0104]

[0105] In the above formula 1, DM1 is the molar ratio of the diol included in the bonding structure 1, DM2 is the molar ratio of the diol included in the bonding structure 2, and DM3 is the molar ratio of the diol included in the bonding structure 3.

[0106] In the above biodegradable aliphatic-aromatic polyester resin, the replacement ratio may be about 0.3 to about 0.7, about 0.37 to about 0.59, about 0.4 to about 0.56, or about 0.45 to about 0.53.

[0107] The above-mentioned biodegradable aliphatic-aromatic polyester resin may include a hard segment ratio. The hard segment ratio is the ratio of the diol bonded between the aromatic dicarboxylic acid and the aromatic dicarboxylic acid among the diols.

[0108] The hard segment ratio may be the molar ratio of the diol included in the bonding structure 2 among the total diol. The hard segment ratio may be the value obtained by dividing the number of moles of the diol included in the bonding structure 2 by the sum of the number of moles of the diol included in the bonding structure 1, the number of moles of the diol included in the bonding structure 2, and the number of moles of the diol included in the bonding structure 3.

[0109] The above hard segment ratio can be expressed by the following formula 2.

[0110] [Equation 2]

[0111]

[0112] In the above formula 2, DM1 is the molar ratio of the diol included in the bonding structure 1, DM2 is the molar ratio of the diol included in the bonding structure 2, and DM3 is the molar ratio of the diol included in the bonding structure 3.

[0113] The above hard segment ratio may be about 0.15 to about 0.35, about 0.2 to about 0.3, about 0.21 to about 0.29, or about 0.22 to about 0.28.

[0114] The above biodegradable aliphatic-aromatic polyester resin may include soft segments.

[0115] The above soft segment ratio is the ratio of the aliphatic dicarboxylic acid and the diol bonded between the aliphatic dicarboxylic acid among the above diols.

[0116] The above soft segment ratio may be the molar ratio of the diol included in the bonding structure 3 among the total diol. The above soft segment ratio may be the value obtained by dividing the number of moles of the diol included in the bonding structure 3 by the sum of the number of moles of the diol included in the bonding structure 1, the number of moles of the diol included in the bonding structure 2, and the number of moles of the diol included in the bonding structure 3.

[0117] The above soft segment ratio can be expressed by the following formula 3.

[0118] [Equation 3]

[0119]

[0120] In the above formula 3, DM1 is the molar ratio of the diol included in the bonding structure 1, DM2 is the molar ratio of the diol included in the bonding structure 2, and DM3 is the molar ratio of the diol included in the bonding structure 3.

[0121] The above soft segment ratio may be about 0.16 to about 0.36, about 0.21 to about 0.31, about 0.22 to about 0.30, or about 0.23 to about 0.29.

[0122] The above soft segment ratio may be larger than the above hard segment ratio.

[0123] The ratio of the hard segment to the soft segment may be about 0.92 to about 0.99. That is, the value obtained by dividing the DM2 by the DM3 may be about 0.92 to about 0.99.

[0124] The above-mentioned replacement ratio, the above-mentioned hard segment ratio, and the above-mentioned soft segment ratio can be measured by nuclear magnetic resonance spectroscopy. The above-mentioned biodegradable aliphatic-aromatic polyester resin is dissolved in a solvent such as CDCl3, and at room temperature, by a nuclear magnetic resonance (NMR) device, 1 H-NMR and / or 13 It can be analyzed by C-NMR analysis.

[0125] When the above diol is 1,4-butanediol, the above aromatic dicarboxylic acid is terephthalic acid or dimethyl terephthalate, and the above aliphatic dicarboxylic acid is adipic acid, the analysis of the biodegradable aliphatic-aromatic polyester resin by nuclear magnetic resonance spectroscopy may include a first peak, a second peak, a third peak, a fourth peak, a fifth peak, a sixth peak, a seventh peak, an eighth peak, a ninth peak, a tenth peak, and an eleventh peak.

[0126] When the above diol is 1,4-butanediol, the above aromatic dicarboxylic acid is terephthalic acid or dimethyl terephthalate, and the above aliphatic dicarboxylic acid is adipic acid, the analysis of the above biodegradable aliphatic-aromatic polyester resin by nuclear magnetic resonance spectroscopy may include a peak derived from the diol of the above bonding structure 1, a peak derived from the diol of the above bonding structure 2, and a peak derived from the above bonding structure 3 at about 3.5 ppm to about 4.6 ppm.

[0127] In the range of about 3.5 ppm to about 4.6 ppm, the first peak, the second peak, the third peak, and the fourth peak may be defined in order from high ppm to low ppm. Additionally, based on the ppm of the ninth peak, in the range of about -3.4 ppm to about -4.3 ppm, the first peak, the second peak, the third peak, and the fourth peak may be defined in order from high ppm to low ppm.

[0128] The -ppm direction can be the upfield direction or the shielding direction. For example, -3.4 ppm may mean a location of 3.4 ppm in the upfield direction. For example, -3.4 ppm may mean a location of 3.4 ppm in the shielding direction.

[0129] Analysis of the biodegradable aliphatic-aromatic polyester resin by the above nuclear magnetic resonance spectroscopy may include peaks derived from the diol of the bonding structure 1, peaks derived from the diol of the bonding structure 2, and peaks derived from the bonding structure 3, even at about 1.0 ppm to about 2.5 ppm.

[0130] In the range of about 1.0 ppm to about 2.5 ppm, the 10th peak, the 5th peak, the 6th peak, the 7th peak, the 8th peak, and the 11th peak may be defined in order from high ppm to low ppm. Based on the ppm of the 9th peak, in the range of about -6.0 ppm to about -6.7 ppm, the 5th peak, the 6th peak, the 7th peak, the 8th peak, and the 11th peak may be defined in order from high ppm to low ppm.

[0131] The ninth peak may be formed in the range of about 7.5 ppm to about 8.5 ppm. The ninth peak may be derived from the aromatic dicarboxylic acid. The ninth peak may be derived from an aromatic ring contained in the aromatic dicarboxylic acid. The ninth peak may be derived from an aromatic ring contained in the terephthalic acid or dimethyl terephthalate.

[0132] The above 10th peak and the above 11th peak may be derived from the above aliphatic dicarboxylic acid. The above 10th peak and the above 11th peak may be derived from the above adipic acid.

[0133] The first peak may be located at approximately -3.6 ppm to approximately -3.68 ppm based on the ppm of the ninth peak. The second peak may be located at approximately -3.69 ppm to approximately -3.75 ppm based on the ppm of the ninth peak. The third peak may be located at approximately -3.9 ppm to approximately -3.97 ppm based on the ppm of the ninth peak. The fourth peak may be located at approximately -3.98 ppm to approximately -4.1 ppm based on the ppm of the ninth peak. The fifth peak may be located at approximately -6.0 ppm to approximately -6.19 ppm based on the ppm of the ninth peak. The sixth peak may be located at approximately -6.2 ppm to approximately -6.26 ppm based on the ppm of the ninth peak. The 7th peak may be located at approximately -6.27 ppm to approximately -6.34 ppm based on the ppm of the 9th peak. The 8th peak may be located at approximately -6.35 ppm to approximately -6.42 ppm based on the ppm of the 9th peak. The 10th peak may be located at approximately -5.6 ppm to approximately -5.8 ppm based on the ppm of the 9th peak. The 11th peak may be located at approximately -6.421 ppm to approximately -6.5 ppm based on the ppm of the 9th peak. The position based on the ppm of the 9th peak may be the position of each peak when the position of the 9th peak is 0 ppm.

[0134] The areas of the first peak, the second peak, the third peak, the fourth peak, the fifth peak, the sixth peak, the seventh peak, the eighth peak, the tenth peak, and the eleventh peak can be normalized based on the area of ​​the ninth peak. That is, when the area of ​​the ninth peak is 1, the areas of the first peak, the second peak, the third peak, the fourth peak, the fifth peak, the sixth peak, the seventh peak, the eighth peak, the tenth peak, and the eleventh peak can be determined relatively.

[0135] The above alternating ratio can be derived using the following Equation 4 or Equation 5.

[0136] [Equation 4]

[0137]

[0138] In the above formula 4, PA1 is the area of ​​the first peak, PA2 is the area of ​​the second peak, PA3 is the area of ​​the third peak, and PA4 is the area of ​​the fourth peak.

[0139] [Formula 5]

[0140]

[0141] In the above formula 5, PA5 is the area of ​​the fifth peak, PA6 is the area of ​​the sixth peak, PA7 is the area of ​​the seventh peak, and PA8 is the area of ​​the eighth peak.

[0142] The above hard segment ratio can be derived using the following formula 6 or the following formula 7.

[0143] [Equation 6]

[0144]

[0145] In the above formula 6, PA1 is the area of ​​the first peak, PA2 is the area of ​​the second peak, PA3 is the area of ​​the third peak, and PA4 is the area of ​​the fourth peak.

[0146] [Equation 7]

[0147]

[0148] In the above formula 7, PA5 is the area of ​​the fifth peak, PA6 is the area of ​​the sixth peak, PA7 is the area of ​​the seventh peak, and PA8 is the area of ​​the eighth peak.

[0149] The above soft segment ratio can be derived using the following formula 8 or formula 9.

[0150] [Equation 8]

[0151]

[0152] In the above formula 8, PA1 is the area of ​​the first peak, PA2 is the area of ​​the second peak, PA3 is the area of ​​the third peak, and PA4 is the area of ​​the fourth peak.

[0153] [Formula 9]

[0154]

[0155] In the above formula 9, PA5 is the area of ​​the fifth peak, PA6 is the area of ​​the sixth peak, PA7 is the area of ​​the seventh peak, and PA8 is the area of ​​the eighth peak.

[0156] The area of ​​the first peak may be about 0.35 to about 0.6, about 0.4 to about 0.55, about 0.43 to about 0.5, about 0.43 to about 0.52, or about 0.45 to about 0.49.

[0157] The area of ​​the second peak may be about 0.37 to about 0.57, about 0.41 to about 0.54, about 0.45 to about 0.53, about 0.45 to about 0.55, or about 0.47 to about 0.53.

[0158] The area of ​​the third peak may be about 0.37 to about 0.57, about 0.41 to about 0.54, about 0.45 to about 0.53, about 0.45 to about 0.55, or about 0.47 to about 0.53.

[0159] The area of ​​the fourth peak may be about 0.4 to about 0.7, about 0.45 to about 0.65, about 0.48 to about 0.6, about 0.48 to about 0.60, or about 0.50 to about 0.58.

[0160] The area of ​​the fifth peak above may be about 0.35 to about 0.6, about 0.4 to about 0.55, about 0.43 to about 0.53, about 0.43 to about 0.52, or about 0.45 to about 0.49.

[0161] The area of ​​the sixth peak may be about 0.35 to about 0.6, about 0.4 to about 0.55, about 0.43 to about 0.5, about 0.45 to about 0.55, or about 0.47 to about 0.53.

[0162] The area of ​​the seventh peak may be about 0.41 to about 0.71, about 0.45 to about 0.65, about 0.48 to about 0.6, about 0.45 to about 0.55, or about 0.47 to about 0.53.

[0163] The area of ​​the eighth peak may be about 0.4 to about 0.7, about 0.45 to about 0.65, about 0.48 to about 0.6, or about 0.50 to about 0.58.

[0164] The area of ​​the 10th peak may be about 0.7 to about 2.5, about 0.75 to about 2, about 0.8 to about 1.5, about 1.0 to about 1.15, or about 1.02 to about 1.13.

[0165] The area of ​​the 11th peak may be about 0.7 to about 3.5, about 0.7 to about 3, about 0.8 to about 2.5, about 1.0 to about 1.15, or about 1.02 to about 1.13.

[0166] The sum of the areas of the first peak, the second peak, the third peak, and the fourth peak may be about 1.49 to about 2.44, about 1.81 to about 2.16, about 1.9 to about 2.2, or about 1.95 to about 2.1. Here, the sum of the areas of the first peak, the second peak, the third peak, and the fourth peak may represent the sum of the total number of ester bonds based on the number of terephthalic acids.

[0167] The sum of the areas of the second peak and the third peak may be about 0.95 to about 1.10, or about 0.98 to about 1.07. Here, the sum of the areas of the first peak and the third peak may represent the degree of extension of the molecular bonds of the biodegradable aliphatic-aromatic polyester resin.

[0168] The ratio of the area of ​​the fourth peak to the area of ​​the first peak (area of ​​the fourth peak / area of ​​the first peak) may be about 1.1 to about 1.3, about 0.67 to about 2, about 0.96 to about 1.40, or about 1.15 to about 1.25. The ratio of the area of ​​the fourth peak to the area of ​​the first peak may refer to the ratio of the soft segment to the hard segment within the molecular structure of the biodegradable aliphatic-aromatic polyester resin. That is, the higher the ratio of the area of ​​the fourth peak to the area of ​​the first peak, the more the biodegradable aliphatic-aromatic polyester resin may have improved adhesive properties.

[0169] The ratio of the area of ​​the fourth peak to the area of ​​the third peak (area of ​​the fourth peak / area of ​​the third peak) may be about 0.7 to about 1.89, about 0.91 to about 1.33, about 1.0 to about 1.2, or about 1.01 to about 1.1.

[0170] The ratio of the area of ​​the first peak to the area of ​​the second peak (area of ​​the first peak / area of ​​the second peak) may be about 0.61 to about 1.62, about 0.81 to about 1.11, about 0.85 to about 0.95, or about 0.86 to about 0.94.

[0171] The ratio of the fifth peak area to the first peak area (area of ​​the fifth peak / area of ​​the first peak) may be about 0.61 to about 1.71, about 0.96 to about 1.40, about 0.8 to about 1.2, or about 0.9 to about 1.1.

[0172] The ratio of the area of ​​the sixth peak to the area of ​​the second peak (area of ​​the sixth peak / area of ​​the second peak) may be about 0.58 to about 1.71, about 0.86 to about 1.16, about 0.8 to about 1.2, or about 0.9 to about 1.1.

[0173] The ratio of the area of ​​the seventh peak to the area of ​​the third peak (area of ​​the seventh peak / area of ​​the third peak) may be about 0.72 to about 1.92, about 0.91 to about 1.33, about 0.8 to about 1.2, or about 0.9 to about 1.1.

[0174] The ratio of the area of ​​the eighth peak to the area of ​​the fourth peak (area of ​​the eighth peak / area of ​​the fourth peak) may be about 0.59 to about 1.75, about 0.80 to about 1.2, or about 0.9 to about 1.1.

[0175] The number average molecular weight of the above biodegradable aliphatic-aromatic polyester resin may be 20,000 g / mol to 100,000 g / mol, 20,000 g / mol to 90,000 g / mol, 20,000 g / mol to 80,000 g / mol, or 20,000 g / mol to 45,000 g / mol. When the above range is satisfied, the biodegradability is excellent, and changes in mechanical properties due to environmental changes can be minimized.

[0176] The above biodegradable aliphatic-aromatic polyester resin may have a crystallization temperature measured by differential scanning calorimetry (DSC) of 50 ℃ to 100 ℃, 60 ℃ to 100 ℃, 70 ℃ to 100 ℃, or 70 ℃ to 90 ℃.

[0177] The above biodegradable aliphatic-aromatic polyester resin may have a degree of crystallinity measured by the above differential scanning calorimeter of 10% to 30%, 10% to 25%, 12% to 25%, or 15% to 25%.

[0178] Specifically, the degree of crystallization is determined by placing about 5 mg to 10 mg of the sample to be analyzed into a differential scanning calorimeter pan, and then melting the sample at about 200 °C to 220 °C for about 5 minutes under an inert gas atmosphere to remove the thermal history. Afterward, the sample is cooled rapidly to a non-crystalline state, and then heated again at a heating rate of about 10 °C / min, and the degree of crystallization is calculated by the following equation based on the peak that appears.

[0179] [ceremony]

[0180] Degree of Crystallinity (%) = [(Enthalpy of melting of sample (J / g) - Enthalpy of cooling crystallization of sample (J / g)) / (Enthalpy of melting of 100% crystalline phase of sample (J / g))] X 100

[0181] The above biodegradable aliphatic-aromatic polyester resin may have a glass transition temperature measured by the above differential scanning calorimeter of -50 ℃ to 0 ℃, -40 ℃ to 0 ℃, -40 ℃ to -10 ℃, or -30 ℃ to -10 ℃.

[0182] The above biodegradable aliphatic-aromatic polyester resin may have a melting point measured by the differential scanning calorimeter of 80°C to 200°C, 100°C to 200°C, 100°C to 180°C, or 100°C to 160°C.

[0183] The above biodegradable aliphatic-aromatic polyester resin may have a melt index of 25 g / 10min to 40 g / 10min, 25 g / 10min to 38 g / 10min, 25 g / 10min to 35 g / 10min, or 28 g / 10min to 35 g / 10min when measured under conditions of 190 ℃ and 2.16 kg.

[0184] The above biodegradable aliphatic-aromatic polyester resin may have a melt index of 30 g / 10min to 70 g / 10min, 35 g / 10min to 70 g / 10min, 35 g / 10min to 65 g / 10min, or 40 g / 10min to 60 g / 10min when measured under conditions of 210 ℃ and 2.16 kg.

[0185] If the above range is satisfied, the biodegradable aliphatic-aromatic polyester resin can be easily spun. In addition, tensile strength, elongation, and stiffness can be improved, and the nonwoven fabric containing the biodegradable fiber can have a soft touch.

[0186] The weight ratio of the above biodegradable aliphatic polyester resin to the above biodegradable aliphatic-aromatic polyester resin may be 20:80 to 60:40, 30:70 to 60:40, 40:60 to 60:40, or 50:50 to 60:40. When the above range is satisfied, the tensile strength and elongation may be further improved.

[0187] The tenacity of the above biodegradable fiber (10) may be 1.5 gf / d to 5.0 gf / d, 1.5 gf / d to 4.8 gf / d, 1.5 gf / d to 4.6 gf / d, or 1.5 gf / d to 4.5 gf / d. The tenacity may be defined as g / d, which is the value obtained by dividing the load at which the biodegradable fiber is cut when the tensile fiber is cut after gripping the biodegradable fiber in a universal testing machine.

[0188] The diameter of the above biodegradable fiber (10) may be 5 μm to 100 μm, 25 μm to 100 μm, 35 μm to 100 μm, or 60 μm to 100 μm.

[0189]

[0190] The resin composition for biodegradable fibers according to the present invention comprises a biodegradable aliphatic-aromatic polyester resin comprising a diol-derived unit, an aromatic dicarboxylic acid-derived unit, and an aliphatic dicarboxylic acid-derived unit, and a nucleating agent, wherein the molar ratio of the aromatic dicarboxylic acid to the aliphatic dicarboxylic acid may be 1:1 to 1.3:1.

[0191] The above-mentioned biodegradable aliphatic-aromatic polyester resin may be the same as the aforementioned biodegradable aliphatic-aromatic polyester resin. The above-mentioned biodegradable fiber resin composition may be the same as the aforementioned biodegradable aliphatic-aromatic polyester resin.

[0192] The above-mentioned resin composition for biodegradable fibers may have a melt index of 25 g / 10min to 40 g / 10min, 25 g / 10min to 38 g / 10min, 25 g / 10min to 35 g / 10min, or 28 g / 10min to 35 g / 10min when measured under conditions of 190 ℃ and 2.16 kg.

[0193] The above melt index can be measured in accordance with ASTM D1238. Specifically, after a sample of the resin composition for biodegradable fibers is prepared, about 3 g to 8 g of the sample is introduced into the cylinder of a preheated melt indexer. Subsequently, the sample is pressurized by a piston to melt it at 190 ℃, and the preheating is maintained for about 5 to 7 minutes. Afterward, a standard load of 2.16 kg is placed on the piston to apply the load, and the molten material is collected at regular intervals, such as about 30 seconds or 1 minute, starting from the moment the load is applied. This process is repeated for a total of 10 minutes, and the total mass of the collected molten material is summed and divided by 10 to obtain a melt index (MI) value in units of 'g / 10min'.

[0194] The above nucleating agent may be a substance that forms a nucleus for the formation of a crystal nucleus.

[0195] When the above nucleating agent is included, the crystallization rate of the resin composition for biodegradable fibers can be improved. The crystallization temperature of the resin composition for biodegradable fibers can be controlled by the above nucleating agent.

[0196] The nucleating agent content may be 0.1 phr to 4 phr, 0.5 phr to 4 phr, 0.5 phr to 4 phr, or 0.5 phr to 3 phr relative to the biodegradable aliphatic-aromatic polyester resin. When the above range is satisfied, it can be uniformly dispersed in the biodegradable aliphatic-aromatic polyester resin, and the mechanical properties of the biodegradable fiber produced from the resin composition for biodegradable fibers can be improved.

[0197] The above nucleating agent may include nanocellulose and inorganic materials.

[0198] The above nanocellulose may be one or more selected from the group consisting of nanocrystalline cellulose, cellulose nanofiber, microfibrillated cellulose, hydroxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, hydroxypropylmethyl cellulose, cellulose acetate, methyl cellulose, ethyl cellulose, propyl cellulose, butyl cellulose, pentyl cellulose, hexyl cellulose, or cyclohexyl cellulose.

[0199] The above nanocellulose may include an ionically bonded metal. The above nanocrystalline cellulose may include an alkali metal. The above nanocellulose may include a sodium element. Additionally, the above nanocellulose may include a sulfate. The above nanocellulose may include a carboxylic acid salt. The above nanocellulose may be cellulose hydrogen sulfate sodium salt.

[0200] The above nanocellulose can be represented by the following chemical formula 2.

[0201] [Chemical Formula 2]

[0202]

[0203] Here, x may be 1 to 35 and y may be 1 to 10. x may be 15 to 35 and y may be 1 to 10.

[0204] The sulfur content of the nanocellulose may be about 0.1% to about 1.2% by weight, about 0.5% to about 1.2% by weight, or about 0.75% to about 1.1% by weight based on the total nanocellulose. The sulfur content of the nanocellulose may be measured according to ASTM D2622.

[0205] The above nanocellulose may include a surface treatment agent. The surface treatment agent may include at least one from the group consisting of sulfates or carboxylates. That is, the nanocellulose may be surface-treated by the sulfate or carboxylate.

[0206] The zeta potential of the above nanocellulose may be about -50 mV to about -25 mV, about -45 mV to about -30 mV, about -60 mV to about -25 mV, or about -55 mV to about -30 mV. The zeta potential of the above cellulose may be measured by a zeta potential meter (e.g., Zetasizer Nano ZS, Malvern).

[0207] Since the above nanocellulose has the above characteristics, it can be uniformly dispersed in the above biodegradable aliphatic-aromatic polyester resin, and the mechanical properties of the biodegradable fiber produced from the above biodegradable fiber resin composition can be improved.

[0208] The above inorganic material may include at least one of mica, talc, silica, titanium dioxide (TiO2), and calcium carbonate (CaCO3).

[0209] The above-mentioned resin composition for biodegradable fibers may include a melt strength enhancer.

[0210] Generally, biodegradable aliphatic-aromatic polyester resins containing diol-derived units, aliphatic dicarboxylic acid-derived units, and aromatic dicarboxylic acid-derived units exhibit characteristics of a low crystallization temperature and a slow crystallization rate. As a result, flow stability within the fiber is not ensured during the spinning process at temperatures above 200°C, leading to a problem where the fiber breaks.

[0211] To resolve the above-mentioned problems, a melt strength reinforcing agent capable of enhancing the flow stability within the fiber may be introduced. As a result, the elongation of the fiber during the spinning process can be improved, thereby suppressing the phenomenon of fiber breakage.

[0212] The above-mentioned melt strength reinforcing agent may have a weight-average molecular weight of 500 g / mol to 2,000 g / mol, 500 g / mol to 1,000 g / mol, 500 g / mol to 800 g / mol, or 500 g / mol to 600 g / mol. The above-mentioned melt strength reinforcing agent may have a melting point (Tm) of 140 ℃ to 147 ℃, 141 ℃ to 147 ℃, 142 ℃ to 147 ℃, or 145 ℃ to 147 ℃. The above-mentioned melt strength reinforcing agent may have a crystallization temperature (Tc) of 100 ℃ to 150 ℃, 110 ℃ to 150 ℃, 130 ℃ to 150 ℃, or 140 ℃ to 150 ℃.

[0213] The above-mentioned melt strength enhancer may have a thermal decomposition temperature of 200°C or higher when heated to 900°C at a rate of 20°C / min using a thermogravimetric analyzer (TGA), and a weight loss rate of 20% or less when heated isothermally for 360 minutes after heating to 240°C at a rate of 20°C / min. The above-mentioned melt strength enhancer may have a thermal decomposition temperature of 200°C or higher when heated to 900°C at a rate of 20°C / min using a thermogravimetric analyzer (TGA), and a weight loss rate of 18% or less when heated isothermally for 360 minutes after heating to 240°C at a rate of 20°C / min. The above-mentioned melt strength reinforcing agent may have a thermal decomposition temperature of 200°C or higher when heated to 900°C at a rate of 20°C / min in a nitrogen atmosphere using a thermogravimetric analyzer (TGA), and a weight loss rate of 16% or less when heated isothermally for 360 minutes after heating to 240°C at a rate of 20°C / min.

[0214] The above weight reduction rate can be calculated according to the following formula.

[0215] [ceremony]

[0216] Weight loss rate (%) = {1 - (TGA sample weight (g) / Initial sample weight (g))} × 100

[0217] In the above formula, the initial sample weight is the sample weight (g) at the initial room temperature of the TGA, and the TGA sample weight is the sample weight (g) at 900 ℃ after the TGA temperature is raised.

[0218] If the above range is satisfied, the physical properties of the melt strength reinforcing agent may be prevented from deteriorating during the high-temperature spinning process.

[0219] The above melt strength reinforcing agent may have a LogP (distribution coefficient) value of 10 to 20, 11 to 20, 11 to 19, or 11 to 18.

[0220] The above LogP value is the octanol / water partition coefficient (P ow It may represent the logarithmic value of ). The above LogP value may be a parameter value indicating the hydrophilicity / hydrophobicity of the compound. If the above range is satisfied, the dispersibility of the biodegradable aliphatic-aromatic polyester resin may be improved.

[0221] The above melt strength enhancing agent may include saturated fatty acid amides.

[0222] The above saturated fatty acid amide may have two or more amide groups per molecule.

[0223] The above saturated fatty acid amide may not contain an amide group at the molecular terminal.

[0224] The above-mentioned saturated fatty acid amide may be a compound in which the molecule forms a symmetric structure.

[0225] When the above-mentioned melt strength reinforcing agent includes a saturated fatty acid amide having the above characteristics, it may exhibit a polarity that facilitates reaction with the above-mentioned biodegradable aliphatic-aromatic polyester resin, and excessive polarization may be suppressed, thereby improving dispersibility with respect to the above-mentioned biodegradable aliphatic-aromatic polyester resin.

[0226] The above melt strength reinforcing agent may include one or more selected from the group consisting of Ethylenebis(stearamide), Ethylenebis-12-hydroxystearamide, and Stearyl Erucamide.

[0227] The above resin composition for biodegradable fibers may include an anti-sticking agent.

[0228] By the above anti-sticking agent, surface friction is reduced, and as the adhesive properties are degraded, the phenomenon of fibers being spliced ​​together during the spinning process can be suppressed.

[0229] The above anti-adhesion agent may have a weight-average molecular weight of 200 g / mol to 1,000 g / mol, 200 g / mol to 800 g / mol, 200 g / mol to 500 g / mol, or 300 g / mol to 400 g / mol. The above anti-adhesion agent may have a melting point (Tm) of 75 ℃ to 85 ℃, 77 ℃ to 85 ℃, 79 ℃ to 85 ℃, or 80 ℃ to 85 ℃. The above anti-adhesion agent may have a crystallization temperature (Tc) of 50 ℃ to 100 ℃, 60 ℃ to 100 ℃, 70 ℃ to 100 ℃, or 70 ℃ to 90 ℃.

[0230] The above anti-stick agent may have a LogP value of less than 5 to 10, less than 5.5 to 10, 5.5 to 9.5, or 6 to 9.5. When the above range is satisfied, the phenomenon of fibers being spliced ​​together during the spinning process can be suppressed more efficiently.

[0231] The above anti-adhesion agent may include an alkene. The above anti-adhesion agent may include an amide group at a molecular terminal. The above anti-adhesion agent may include an amide group at one of the molecular terminals. The above anti-adhesion agent may include a compound in a cis form. The above anti-adhesion agent may include an unsaturated fatty acid amide. The above anti-adhesion agent may include an unsaturated fatty acid amide in a cis form.

[0232] The anti-stick agent described above has a carbon-carbon double bond, which can increase the polarity of the molecule and improve the slip between the biodegradable aliphatic-aromatic polyester resins, thereby providing an anti-blocking function.

[0233] The above anti-stick agent may include one or more selected from the group consisting of Erucamide and Oleamide.

[0234] The solubility of the melt strength reinforcing agent in the above biodegradable aliphatic-aromatic polyester resin may be lower than the solubility of the anti-sticking agent in the above biodegradable aliphatic-aromatic polyester resin.

[0235] The above-degradable fiber resin composition includes a melt strength reinforcing agent with relatively low solubility in the biodegradable aliphatic-aromatic polyester resin, thereby enhancing flow stability within the fiber and improving the elongation of the fiber, which can suppress the phenomenon of fiber breakage during the spinning process.

[0236] In addition, the above-degradable fiber resin composition includes an anti-sticking agent with relatively high solubility in the biodegradable aliphatic-aromatic polyester resin, thereby enabling a relatively fast surface release rate of the fiber, which reduces surface friction of the fiber and lowers the adhesive properties between fibers, so that the phenomenon of fibers being spliced ​​together during the spinning process can be suppressed.

[0237] The total content of the melt strength enhancing agent and the anti-sticking agent may be 0.1 phr to 3 phr, 0.8 phr to 3 phr, 1 phr to 3 phr, or 1.5 phr to 3 phr relative to the biodegradable aliphatic-aromatic polyester resin. When the above range is satisfied, a smooth spinning process can be achieved without deterioration of the mechanical properties of the nonwoven fabric being manufactured.

[0238] The above-mentioned resin composition for biodegradable fibers may have a crystallization time at 90°C according to the following measurement method of 2 minutes (min) or less, 1.8 minutes or less, 1.6 minutes or less, 1.54 minutes or less, 1 minute or less, or 0.5 minutes to 1 minute.

[0239] [measurement method]

[0240] 1) The above-mentioned resin composition for biodegradable fibers is heated to 220°C at a heating rate of 10°C / min and then maintained for 5 minutes.

[0241] 2) The above-mentioned resin composition for biodegradable fibers is heated to 90°C at a heating rate of 100°C / min, and then maintained in an isothermal state for 60 minutes.

[0242] 3) Using Differential Scanning Calorimetry (DSC), the time at which the crystallization peak of the resin composition for biodegradable fibers becomes half the total area of ​​the crystallization peak of the resin composition for biodegradable fibers is measured.

[0243] The above crystallization time is to evaluate the time until crystallization after rapidly cooling the resin composition for biodegradable fibers in a molten state.

[0244] The short crystallization time mentioned above indicates that crystallization proceeds rapidly. Rapid crystallization may mean that molecular motion is inhibited in the early stages after cooling, and a crystalline region is formed.

[0245] The above crystallization time can be adjusted depending on the inclusion, content, etc. of the aforementioned melt strength enhancing agent, anti-sticking agent, and nucleating agent.

[0246] The fact that the above-mentioned resin composition for biodegradable fibers has a crystallization time according to the above-mentioned measurement method signifies a crystallization rate at which the above-mentioned resin composition for biodegradable fibers can be manufactured into a nonwoven fabric by a spinning process, and at the same time, it may serve as an indicator that the occurrence of fusion between fibers and the phenomenon of fiber breakage during the spinning process can be suppressed. When the crystallization time within the above range is satisfied, a smooth spinning process can be carried out without a decrease in the mechanical properties of the nonwoven fabric produced from the above-mentioned resin composition for biodegradable fibers.

[0247]

[0248] The biodegradable nonwoven fabric according to the present invention comprises biodegradable fibers, wherein the biodegradable fibers comprise a core portion and a sheath portion surrounding the outer surface of the core portion, wherein the core portion comprises a biodegradable aliphatic polyester resin, and the sheath portion comprises a biodegradable aliphatic-aromatic polyester resin, and wherein the biodegradable aliphatic-aromatic polyester resin may have a melt index of 25 g / 10 min to 40 g / 10 min when measured under conditions of 190 ℃ and 2.16 kg.

[0249] The above-mentioned biodegradable fiber may be the same as the aforementioned biodegradable fiber.

[0250] The above biodegradable nonwoven fabric can satisfy all of the following conditions (1) to (3).

[0251] (1) The basis weight of the above biodegradable nonwoven fabric is 15 gsm (Grams per Square Meter) to 40 gsm

[0252] (2) The thickness of the above biodegradable nonwoven fabric is 0.05 mm or more

[0253] (3) The tensile strength of the above biodegradable nonwoven fabric in the MD (Machine Direction) direction is 14 N / 5cm to 50 N / 5cm, and the tensile strength in the CD (Cross Direction) direction is 8 N / 5cm to 30 N / 5cm

[0254] If the above biodegradable nonwoven fabric satisfies all of the above conditions (1) to (3), a reduction in weight can be achieved without a decrease in mechanical properties.

[0255] Specifically, the basis weight of the biodegradable nonwoven fabric may be 15 gsm to 40 gsm, 15 gsm to 38 gsm, 15 gsm to 35 gsm, or 20 gsm to 35 gsm.

[0256] The thickness of the above nonwoven fabric may be 0.05 mm or more, 0.1 mm or more, 0.12 mm or more, 0.15 mm or more, or 0.1 mm or more to 1 mm or less.

[0257] The tensile strength of the above nonwoven fabric in the MD direction may be 14 N / 5cm to 50 N / 5cm, 20 N / 5cm to 50 N / 5cm, 22 N / 5cm to 50 N / 5cm, 25 N / 5cm to 50 N / 5cm, or 25 N / 5cm to 40 N / 5cm.

[0258] The tensile strength of the above nonwoven fabric in the CD direction may be 8 N / 5cm to 30 N / 5cm, 10 N / 5cm to 30 N / 5cm, 12 N / 5cm to 30 N / 5cm, 15 N / 5cm to 30 N / 5cm, or 18 N / 5cm to 25 N / 5cm.

[0259] The elongation of the biodegradable nonwoven fabric in the MD direction may be 20% to 80%, and the elongation in the CD direction may be 40% to 90%. The elongation of the biodegradable nonwoven fabric in the MD direction may be 20% to 50%, and the elongation in the CD direction may be 30% to 70%. The elongation of the biodegradable nonwoven fabric in the MD direction may be 25% to 50%, and the elongation in the CD direction may be 40% to 70%.

[0260] The softness of the above biodegradable nonwoven fabric in the MD direction may be 60 mm or less, and the softness in the CD direction may be 45 mm or less. The softness of the above biodegradable nonwoven fabric in the MD direction may be 58 mm or less, and the softness in the CD direction may be 48 mm or less. The softness of the above biodegradable nonwoven fabric in the MD direction may be 55 mm or less, and the softness in the CD direction may be 45 mm or less.

[0261] If the above range is satisfied, the biodegradable nonwoven fabric can have flexibility and simultaneously improve strength.

[0262] The above-mentioned biodegradable nonwoven fabric may be a spunbond nonwoven fabric, a meltblown nonwoven fabric, a needle-punched nonwoven fabric, a spunlace nonwoven fabric, a thermal bonded nonwoven fabric, a chemical bonded nonwoven fabric, or a dry-laid nonwoven fabric. Preferably, the above-mentioned biodegradable nonwoven fabric may be a spunbond nonwoven fabric.

[0263] The above biodegradable nonwoven fabric can be manufactured by the steps of melting the biodegradable aliphatic polyester resin and the aliphatic-aromatic polyester resin in separate extruders, introducing the molten biodegradable aliphatic polyester resin into the inner side of a distribution plate and introducing the molten biodegradable aliphatic-aromatic polyester resin into the outer side of a distribution plate, extruding core-sheath type fibers from a spinning block, compressing the fibers after lamination, and winding the bundled fibers.

[0264] A core portion of the fiber may be formed by the biodegradable aliphatic polyester resin introduced into the inner side of the distribution plate. A sheath portion surrounding the outer surface of the core portion may be formed by the biodegradable aliphatic-aromatic polyester resin introduced into the outer side of the distribution plate.

[0265]

[0266] FIG. 3 is a cross-sectional view of a biodegradable sanitary product according to one embodiment of the present invention. FIG. 4 is a top view of a biodegradable sanitary product according to one embodiment of the present invention.

[0267] Referring to FIGS. 3 and 4, a biodegradable sanitary product (100) according to the present invention comprises a waterproof layer (20), an absorbent layer (30) formed on the waterproof layer (20), a dispersion layer (40) formed on the absorbent layer (30), and a top sheet (50) formed on the dispersion layer (40). At least one of the waterproof layer (20), the absorbent layer (30), the dispersion layer (40), and the top sheet (50) comprises a biodegradable nonwoven fabric. The biodegradable nonwoven fabric comprises biodegradable fibers. The biodegradable fibers comprise a biodegradable aliphatic polyester resin and a biodegradable aliphatic-aromatic polyester resin. The biodegradable aliphatic-aromatic polyester resin may have a melt index of 25 g / 10 min to 40 g / 10 min when measured under conditions of 190 ℃ and 2.16 kg.

[0268] The above biodegradable fiber includes a core portion and a sheath portion surrounding the outer surface of the core portion, the core portion includes the biodegradable aliphatic polyester resin, and the sheath portion may include the biodegradable aliphatic-aromatic polyester resin.

[0269] The above-mentioned biodegradable fiber may be the same as the aforementioned biodegradable fiber.

[0270] The above biodegradable hygiene product (100) may be a wet wipe, diaper, sanitary pad, panty liner, or incontinence pad.

[0271] The above biodegradable sanitary product (100) may include a protective sheet (not shown) formed on the lower surface of the waterproof layer (20). The above biodegradable sanitary product (100) may include an adhesive layer to maintain adhesion between the waterproof layer (20) and the protective sheet.

[0272] The above biodegradable sanitary product (100) may include a side cover (60).

[0273] The side cover (60) may be spaced apart and disposed on both sides of the top sheet (50). The side cover (60) may include a pleated structure and / or an elastic band.

[0274] The phenomenon of secretions absorbed on the biodegradable sanitary product (100) spreading outward along both sides can be prevented by the above side cover (60).

[0275] The above side cover (60) may include the biodegradable nonwoven fabric.

[0276] The above side cover (60) may include a material selected from the group consisting of polyethylene film, polypropylene film, breathable waterproof film, synthetic fiber, and organic cotton.

[0277] The leakage of secretions absorbed by the waterproof layer (20) can be suppressed. Breathability can be provided by the waterproof layer (20). The overall shape of the biodegradable sanitary product (100) can be maintained by the waterproof layer (20).

[0278] The above waterproof layer (20) may include the above biodegradable nonwoven fabric.

[0279] The above waterproof layer (20) may include a biodegradable film selected from the group consisting of PLA, PBS, PBSA, PCL, PGA, and PHB.

[0280] The secretions that the biodegradable sanitary product (100) comes into contact with can be absorbed by the absorbent layer (30). The absorbed secretions are stored by the absorbent layer (30), and the diffusion of the secretions to the waterproof layer (20) can be suppressed.

[0281] The absorbent layer (30) may have a multilayer structure. The stored secretion can be evenly distributed by the absorbent layer (30) having a multilayer structure.

[0282] The secretion stored by the absorbent layer (30) can be prevented from being discharged back onto the user's skin. The user's skin can be kept wet or irritated by the absorbent layer (30).

[0283] The above absorbent layer (30) may include the above biodegradable nonwoven fabric.

[0284] The above absorption layer (30) may include wood-based pulp and / or super absorbent resin (SAP).

[0285] The absorbent layer (30) may include a biodegradable nonwoven fabric selected from the group consisting of PLA, PBS, PBSA, PCL, PGA, and PHB.

[0286] The secretion absorbed from the top sheet (50) by the dispersion layer (40) can be rapidly transferred to the absorption layer (30).

[0287] The secretion absorbed from the top sheet (50) by the dispersion layer (40) can be evenly distributed to the absorption layer (30).

[0288] The absorption rate of secretions can be improved by the dispersion layer (40), and the backflow or accumulation of secretions into the top sheet (50) can be prevented.

[0289] The dispersion layer (40) may include a porous structure. The dispersion layer (40) may include the biodegradable nonwoven fabric. The dispersion layer (40) may include a biodegradable nonwoven fabric selected from the group consisting of PLA, PBS, PBSA, PCL, PGA, and PHB.

[0290] The top sheet (50) is the upper layer of the biodegradable hygiene product (100) and may be an area that comes into direct contact with the user's skin.

[0291] The secretion can be rapidly absorbed by the top sheet (50) and delivered to the dispersion layer (40). Backflow of the secretion absorbed by the top sheet (50) can be suppressed.

[0292] The top sheet (50) may include the biodegradable nonwoven fabric.

[0293] The above-mentioned biodegradable nonwoven fabric may be a spunbond nonwoven fabric, a meltblown nonwoven fabric, a needle-punched nonwoven fabric, a spunlace nonwoven fabric, a thermal bonded nonwoven fabric, a chemical bonded nonwoven fabric, or a dry-laid nonwoven fabric. Preferably, the above-mentioned biodegradable nonwoven fabric may be a spunbond nonwoven fabric.

[0294] At least a portion of the surface of the above-mentioned biodegradable nonwoven fabric may be surface-treated with a hydrophilic agent.

[0295] The top sheet (50) may include the surface-treated biodegradable nonwoven fabric.

[0296] The hydrophilicity of the surface of the biodegradable nonwoven fabric can be improved by the above surface treatment. As a result, liquid on the biodegradable nonwoven fabric can be rapidly absorbed, and the surface tension of the liquid is reduced, allowing the liquid to be uniformly dispersed over a wide area of ​​the biodegradable nonwoven fabric. In addition, the balance between hydrophilicity and hydrophobicity of the biodegradable nonwoven fabric can be maintained, allowing the liquid to move in a specific direction.

[0297] The above hydrophilic agent may include a wax emulsion, a reactive softener, a silicone-based compound, a surfactant, or a combination thereof.

[0298] The above silicon-based compound may include an amino group-containing silicon, an oxyalkylene group-containing silicon, or a combination thereof.

[0299] The above surfactant is an anionic surfactant such as a carboxylate-type anionic surfactant, a sulfonate-type anionic surfactant, a sulfate ester-type anionic surfactant, or a phosphate ester-type anionic surfactant (especially an alkyl phosphate ester salt); Polyhydric alcohol monofatty acid esters such as sorbitan fatty acid esters, diethylene glycol monostearate, diethylene glycol monooleate, glyceryl monostearate, glyceryl monooleate, propylene glycol monostearate, etc., N-(3-oleyloxy-2-hydroxypropyl)diethanolamine, polyoxyethylene hydrogenated castor oil, polyoxyethylene sorbitol beeswax, polyoxyethylene sorbitan sesquistearate, polyoxyethylene monooleate, polyoxyethylene sorbitan sesquistearate, polyoxyethylene glyceryl monooleate, polyoxyethylene monostearate, polyoxyethylene monolaurate, polyoxyethylene monooleate, polyoxyethylene cetyl ether, polyoxyethylene lauryl ether, etc., nonionic surfactants; cationic surfactants such as quaternary ammonium salts, amine salts, or amines; It may include amphoteric surfactants such as aliphatic derivatives of secondary or tertiary amines containing carboxylates, sulfonates, or sulfates, or aliphatic derivatives of heterocyclic secondary or tertiary amines; or combinations thereof.

[0300] The above hydrophilic agent may include a nonionic hydrophilic agent. The above nonionic hydrophilic agent is a silicon-based compound such as an amino group-containing silicon or an oxyalkylene group-containing silicon; Polyhydric alcohol monofatty acid esters such as sorbitan fatty acid ester, diethylene glycol monostearate, diethylene glycol monooleate, glyceryl monostearate, glyceryl monooleate, propylene glycol monostearate, N-(3-oleyloxy-2-hydroxypropyl)diethanolamine, polyoxyethylene hydrogenated castor oil, polyoxyethylene sorbitol beeswax, polyoxyethylene sorbitan sesquistearate, polyoxyethylene monooleate, polyoxyethylene sorbitan sesquistearate, polyoxyethylene glyceryl monooleate, polyoxyethylene monostearate, polyoxyethylene monolaurate, polyoxyethylene monooleate, polyoxyethylene cetyl ether, polyoxyethylene lauryl ether, etc., may be included; or a combination thereof.

[0301] The hydrophilic agent impregnation amount (Oil Pick-Up, OPU) may be 0.5% to 1.5% by weight, 0.5% to 1.4% by weight, 0.6% to 1.4% by weight, or 0.7% to 1.3% by weight based on the total weight of the biodegradable nonwoven fabric. If the above range is satisfied, the leakage and rewetting properties of the biodegradable nonwoven fabric may be improved.

[0302] The above hydrophilic agent impregnation amount can be calculated according to the following formula.

[0303] [ceremony]

[0304] OPU(%) = (W1-W0) / W0 X 100

[0305] In the above formula, W0 is the weight of the biodegradable nonwoven fabric that does not contain the hydrophilic agent, and W1 is the weight of the biodegradable nonwoven fabric that contains the hydrophilic agent.

[0306]

[0307] The present invention will be described in more detail below based on examples and comparative examples. However, the following examples and comparative examples are merely illustrative for further explaining the present invention, and the present invention is not limited by the following examples and comparative examples.

[0308]

[0309] Preparation Example

[0310] Manufacturing of biodegradable aliphatic-aromatic polyester resin

[0311] Cellulose nanocrystals (Celluforce, NVC-100) in the form of dry powder having a particle size of about 1 μm to about 50 μm were dispersed in water at 1 wt%, and then a tip-type ultrasonic disperser was used to sonicate for 1 minute at an output of about 20,000 J / s to produce pretreated nanocellulose.

[0312] Polybutylene adipate terephthalate (PBAT) was prepared by mixing 1,4-butanediol (1,4-BDO):terephthalic acid (TPA):adipic acid (AA) in a molar ratio of 140 mol%:50 mol%:50 mol%, and containing about 0.9 wt% of the pretreated nanocellulose. A biodegradable aliphatic-aromatic polyester resin was prepared by mixing 1 part by weight of an anti-sticking agent (Erucamide, Mw 338 g / mol), 1 part by weight of a melt strength enhancer (Ethylenebis(stearamide), Mw 593 g / mol), and 0.6 parts by weight of a nucleating agent (TiO2, average particle size about 0.2 μm) relative to 100 parts by weight of the PBAT.

[0313] Physical properties of the manufactured biodegradable aliphatic-aromatic polyester resin

[0314] The melt index (MI) of the above-prepared biodegradable aliphatic-aromatic polyester resin was measured at a temperature of 190°C and 2.16 kg according to ASTM D1238. The MI of the resin was measured as 30 g / 10 min.

[0315] In addition, the resin was measured by Differential Scanning Calorimetry (DSC) to have a degree of crystallization of 19%, a crystallization temperature of 80 ℃, a glass transition temperature of -28 ℃, and a melting point of 120 ℃.

[0316]

[0317] Examples

[0318] Example 1

[0319] A biodegradable aliphatic polyester resin (PLA, MI 10 g / 10 min (based on 190 °C and 2.16 kg)) was melted in a first extruder at a temperature of approximately 240 °C and fed into the inner side of a distribution plate. The biodegradable aliphatic-aromatic polyester resin prepared above was melted in a second extruder at a temperature of approximately 240 °C and fed into the outer side of a distribution plate. Subsequently, a core-sheath type fiber in which the biodegradable aliphatic-aromatic polyester resin surrounds the biodegradable aliphatic polyester resin was extruded from a spinning block at a temperature of approximately 235 °C. At this time, the weight ratio of the biodegradable aliphatic polyester resin to the biodegradable aliphatic-aromatic polyester resin supplied to the spinning block was 60:40.

[0320] Subsequently, the fibers were stacked on a conveyor and compressed on a calender roll under conditions of 60 N / mm and 110 ℃. Afterwards, the bundled fibers were wound on a winder at a speed of about 110 m / min to produce a nonwoven fabric with a thickness of about 0.15 mm and a basis weight of about 35 gsm.

[0321]

[0322] Example 2

[0323] A nonwoven fabric was manufactured by the same process as in Example 1, except that instead of the weight ratio of the biodegradable aliphatic polyester resin to the biodegradable aliphatic-aromatic polyester resin being 60:40 in Example 1, the weight ratio of the biodegradable aliphatic polyester resin to the biodegradable aliphatic-aromatic polyester resin being 55:45.

[0324]

[0325] Example 3

[0326] A nonwoven fabric was manufactured by the same process as in Example 1, except that instead of the weight ratio of the biodegradable aliphatic polyester resin to the biodegradable aliphatic-aromatic polyester resin being 60:40 in Example 1, the weight ratio of the biodegradable aliphatic polyester resin to the biodegradable aliphatic-aromatic polyester resin being 50:50.

[0327]

[0328] Example 4

[0329] A nonwoven fabric was manufactured by the same process as in Example 1, except that instead of the weight ratio of the biodegradable aliphatic polyester resin to the biodegradable aliphatic-aromatic polyester resin being 60:40 in Example 1, the weight ratio of the biodegradable aliphatic polyester resin to the biodegradable aliphatic-aromatic polyester resin being 40:60.

[0330]

[0331] Comparative Example 1

[0332] Biodegradable aliphatic-aromatic polyester resin (PBAT, MI 15 g / 10 min (based on 190 °C and 2.16 kg)) was melted in an extruder at a temperature of about 240 °C. Subsequently, fibers having a single structure were extruded from a spinning block at a temperature of about 235 °C.

[0333] Subsequently, the fibers were stacked on a conveyor and compressed on a calender roll under conditions of 60 N / mm and 110 ℃. Afterwards, the bundled fibers were wound on a winder at a speed of about 100 m / min to produce a nonwoven fabric with a thickness of about 0.1 mm and a basis weight of about 35 gsm.

[0334]

[0335] Comparative Example 2

[0336] The biodegradable aliphatic polyester resin used in Example 1 above was melted in an extruder at a temperature of about 240°C. Subsequently, a fiber having a single structure was extruded from a spinning block at a temperature of about 235°C.

[0337] Subsequently, the fibers were stacked on a conveyor and compressed on a calender roll under conditions of 60 N / mm and 110 ℃. Afterwards, the bundled fibers were wound on a winder at a speed of about 110 m / min to produce a nonwoven fabric with a thickness of about 0.16 mm and a basis weight of about 25 gsm.

[0338]

[0339] Experimental Example

[0340] Experimental Example 1 - Tensile Strength

[0341] For each nonwoven fabric prepared in Examples 1 to 4 and Comparative Examples 1 to 2 above, an INSTRON tester was used according to Edana 20.2-89 to measure the tensile strength in the MD (Machine Direction) and CD (Cross Direction) directions. The results are shown in Table 1 below.

[0342]

[0343] Experimental Example 2 - Elongation

[0344] For each nonwoven fabric prepared in Examples 1 to 4 and Comparative Examples 1 to 2 above, an INSTRON tester was used according to Edana 20.2-89 to measure the elongation in the MD direction and CD direction. The results are shown in Table 1 below.

[0345]

[0346] Experimental Example 3 - Leanness

[0347] For each nonwoven fabric prepared in Examples 1 to 4 and Comparative Examples 1 to 2 above, a specimen with a width of 2.5 cm × a length of 15 cm was prepared. Subsequently, a stiffness measuring instrument was used on the specimen in accordance with KS K ISO 9073-7, and the distance traveled in the MD direction and CD direction until the specimen bent on an inclined surface was measured. The results are shown in Table 1 below.

[0348]

[0349] Experimental Example 4 - Biodegradability

[0350] For each nonwoven fabric prepared in Examples 1 to 4 and Comparative Examples 1 to 2 above, the biodegradability based on the amount of carbon dioxide generated was measured according to KS M3100-1. It was evaluated according to the following criteria, and the results are shown in Table 1 below.

[0351] - Excellent: 95% or higher

[0352] - Good: 60% to less than 95%

[0353] - Insufficient: Less than 60%

[0354]

[0355] Experimental Example 5 - Tactile Evaluation

[0356] For each nonwoven fabric prepared in Examples 1 to 4 and Comparative Examples 1 to 2 above, a tactile evaluation was conducted by the hands of 10 users. Each user assigned a score ranging from 1 to 10, with higher scores assigned for softer touch sensations. The results are shown in Table 1 below.

[0357]

[0358] Classification Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Comparative Example 2 Reference Example 1) Fiber form core-Cisco-Cisco-Cisco-Cisco single-core-Cisco MI 2) 30 g / 10min30 g / 10min30 g / 10min30 g / 10min15 g / 10min- 3) - 4) Basis Weight 35gsm 25gsm 20gsm Thickness 0.15mm 0.15mm 0.15mm 0.10mm 0.16mm 0.13mm Tensile Strength MD 37.1N / 5cm 32.4N / 5cm 31.4N / 5cm 25.4N / 5cm 16.0N / 5cm 36.0N / 5cm 38.0N / 5cm CD 25.0N / 5cm 22.8N / 5cm 22.0N / 5cm 18.5N / 5cm 9.0N / 5cm 20.0N / 5cm 16.0N / 5cm Elongation MD 29% 33% 30% 30% 44% 14% 90% CD 48% 52% 49% 49% 72% 15% 110 % Strength MD 51mm 49mm 47mm 45mm 10mm 61mm 45mm CD 41mm 39mm 37mm 35mm 5mm 42mm 35mm Biodegradability Excellent Excellent Excellent Excellent Excellent Good Not Soggy Tactile Evaluation 8.5 8.5 8.5 8.5 9 38.5 1) Reference Example: PE sheath-PP core composite fiber 2) MI: Biodegradable aliphatic-aromatic polyester melt index (based on 190 ℃ and 2.16 kg) 3), 4) -: Biodegradable aliphatic-aromatic polyester not included

[0359]

[0360] As can be seen in Table 1 above, it was confirmed that the biodegradable nonwoven fabrics of Examples 1 to 4 exhibited mechanical properties equivalent to those of the nonwoven fabric of the Reference Example, which is a conventional non-biodegradable material. In addition, it was confirmed that the tensile strength of the biodegradable nonwoven fabrics of Examples 1 to 4 was improved compared to the biodegradable nonwoven fabric of Comparative Example 1. Furthermore, it was confirmed that the elongation, stiffness, biodegradability, and tactile feel of the biodegradable nonwoven fabrics of Examples 1 to 4 were improved compared to the biodegradable nonwoven fabric of Comparative Example 2.

[0361] As such, the biodegradable nonwoven fabrics of Examples 1 to 4 are biodegradable and eco-friendly, and can have a soft touch, making them applicable to various molded products that can be used on the human body. In addition, by improving tensile strength, elongation, and stiffness, they can exhibit excellent mechanical properties while maintaining flexibility.

[0362]

[0363] The biodegradable fiber according to the example and the biodegradable nonwoven fabric containing the same have excellent biodegradability and can have improved mechanical properties.

Claims

1. A core portion comprising a biodegradable aliphatic polyester resin; and It comprises a biodegradable aliphatic-aromatic polyester resin and a sheath portion surrounding the outer surface of the core portion, The above biodegradable aliphatic-aromatic polyester resin is a biodegradable fiber having a melt index of 25 g / 10 min to 40 g / 10 min measured under conditions of 190 ℃ and 2.16 kg.

2. In Paragraph 1, The above biodegradable aliphatic polyester resin is a biodegradable fiber having a melt index of 5 g / 10 min to 20 g / 10 min measured under the above conditions.

3. In Paragraph 1, The above-mentioned biodegradable aliphatic polyester resin is a biodegradable fiber having a degree of crystallinity of more than 30% to 60% as measured by Differential Scanning Calorimetry (DSC).

4. In Paragraph 1, The above-mentioned biodegradable aliphatic-aromatic polyester resin is a biodegradable fiber having a degree of crystallinity of 10% to 30% as measured by differential scanning calorimetry.

5. In Paragraph 1, A biodegradable fiber having a weight ratio of the above biodegradable aliphatic polyester resin to the above biodegradable aliphatic-aromatic polyester resin of 20:80 to 60:

40.

6. In Paragraph 1, A biodegradable fiber having a tenacity of 1.5 gf / d to 5.0 gf / d.

7. In Paragraph 1, A biodegradable fiber having an average diameter of 5 μm to 100 μm.

8. Includes biodegradable fibers, The above biodegradable fiber includes a core portion and a sheath portion surrounding the outer surface of the core portion, and The above core portion comprises a biodegradable aliphatic polyester resin, and The above sheath comprises a biodegradable aliphatic-aromatic polyester resin, and The above biodegradable aliphatic-aromatic polyester resin is a biodegradable nonwoven fabric having a melt index of 25 g / 10 min to 40 g / 10 min measured under conditions of 190 ℃ and 2.16 kg.

9. In Paragraph 8, A biodegradable nonwoven fabric that satisfies all of the following conditions (1) to (3): (1) The basis weight of the above biodegradable nonwoven fabric is 15 gsm (Grams per Square Meter) to 40 gsm (2) The thickness of the above biodegradable nonwoven fabric is 0.05 mm or more (3) The tensile strength of the above biodegradable nonwoven fabric in the MD (Machine Direction) direction is 14 N / 5cm to 50 N / 5cm, and the tensile strength in the CD (Cross Direction) direction is 8 N / 5cm to 30 N / 5cm 10. In Paragraph 8, A biodegradable nonwoven fabric having an elongation of 20% to 80% in the MD direction and an elongation of 40% to 90% in the CD direction.

11. In Paragraph 8, A biodegradable nonwoven fabric having a stiffness of 60 mm or less in the MD direction and a stiffness of 45 mm or less in the CD direction.

12. In Paragraph 8, The above biodegradable nonwoven fabric is a spunbond nonwoven fabric.

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