Biodegradable resin composition and biodegradable nonwoven fabric

Abstract

The invention relates to a biodegradable resin composition and a biodegradable non-woven fabric. The present invention provides a biodegradable resin composition including a biodegradable resin including a first repeating unit derived from a diol having 2 to 4 carbon atoms and a second repeating unit derived from an aliphatic dicarboxylic acid having 2 to 6 carbon atoms; and an inorganic nucleating agent, in which the biodegradable resin composition has a crystallinity of 15% to 50% as measured using differential scanning calorimetry.

Description

Technical Field

[0001] The present invention relates to a biodegradable resin composition and a biodegradable nonwoven fabric including the same. Background Art

[0002] Polyethylene, polypropylene, and polyethylene terephthalate have been used as materials for clothing fibers, nonwoven fabrics, and the like. In recent years, as concerns about environmental problems have been increasing day by day, there is a need for solutions to address the disposal problems of short-lived clothing fibers and disposable nonwoven fabrics.

[0003] To solve these problems, research on biodegradable resins is currently being actively conducted. Polylactic acid (PLA), polybutylene adipate terephthalate (PBAT), and polybutylene succinate (PBS) have been introduced as biodegradable resins.

[0004] However, compared with other materials, the spinning ability of biodegradable resins is poor, and thus they are limited in the manufacture of fibers or nonwoven fabrics.

[0005] In addition, in order to improve the spinning ability of biodegradable resins, various biodegradable resins are combined, but the miscibility between biodegradable resins with different properties is reduced, resulting in problems such as fiber-to-fiber fusion or fiber breakage after spinning. Summary of the Invention

[0006] Technical Problem

[0007] Therefore, the present invention has been made in view of the above problems, and an object of the present invention is to provide a biodegradable resin composition having excellent biodegradability and improved spinning ability, and a biodegradable nonwoven fabric including the same.

[0008] Technical Solution

[0009] According to one aspect of the present invention, the above and other objects can be achieved by providing a biodegradable resin composition including: a biodegradable resin including a first repeating unit derived from a diol having 2 to 4 carbon atoms and a second repeating unit derived from an aliphatic dicarboxylic acid having 2 to 6 carbon atoms; and an inorganic nucleating agent, wherein the biodegradable resin composition has a crystallinity measured by differential scanning calorimetry of 15% to 50%.

[0010] In an embodiment of the present invention, the molar ratio of the first repeating unit to the second repeating unit may be 4:1 to 1:1.

[0011] In an embodiment of the present invention, the biodegradable resin may further include a third repeating unit derived from an aromatic dicarboxylic acid.

[0012] In an embodiment of the present invention, the molar ratio of the first repeating unit to the third repeating unit may be from 10:3 to 10:7.

[0013] In an embodiment of the present invention, the molar ratio of the second repeating unit to the third repeating unit may be from 3:2 to 2:3.

[0014] In an embodiment of the present invention, based on the total weight of the biodegradable resin composition, an inorganic nucleating agent may be included in an amount of 10 ppm to 10,000 ppm.

[0015] In an embodiment of the present invention, the inorganic nucleating agent may include one or more selected from the group consisting of titanium dioxide, talc, kaolinite, montmorillonite, mica, clay, zeolite, silica, graphite, carbon black, mica, barium sulfate, calcium silicate, calcium carbonate, calcium sulfide, calcium titanate, zinc oxide, alumina, magnesia, neodymium oxide, and boron nitride.

[0016] In an embodiment of the present invention, the biodegradable resin composition may include nanocellulose having an average length of 10 nm to 300 nm.

[0017] In an embodiment of the present invention, based on the total weight of the biodegradable resin composition, nanocellulose may be included in an amount of 10 ppm to 500 ppm.

[0018] In an embodiment of the present invention, the biodegradable resin composition may include a branching agent including at least one of a trivalent or higher alcohol and a trivalent or higher carboxylic acid.

[0019] In an embodiment of the present invention, based on the total weight of the biodegradable resin composition, the content of the branching agent may be included in an amount of 500 ppm to 3,000 ppm.

[0020] In an embodiment of the present invention, the biodegradable resin composition may have a melt flow rate of 10 g / 10 min to 25 g / 10 min as measured at 190 °C and 2.16 kg.

[0021] In an embodiment of the present invention, according to the following Measuring Method 1, the biodegradable resin composition may have an adhesion strength of 5 kgf or less:

[0022] [Measuring Method 1]

[0023] 1) Compress the biodegradable resin composition at 210 °C under a pressure of 10 MPa for 3 minutes to produce a sheet having a width of 20 mm, a length of 100 mm, and a thickness of 0.3 mm;

[0024] 2) Place the two sheets with a length of 75 mm horizontally face to face, and then bond them at 90 °C under a pressure of 5 MPa for 10 minutes;

[0025] 3) To measure the bond strength of the two bonded sheets, conduct a 180° lap shear test at a tensile speed of 100 mm / min.

[0026] In an embodiment of the present invention, according to Measurement Method 2 below, the biodegradable resin composition may have an isothermal crystallization time of 10 seconds to 300 seconds at 70 °C:

[0027] [Measurement Method 2]

[0028] 1) Heat the biodegradable resin composition to 220 °C at a heating rate of 10 °C / min and then hold for 5 minutes;

[0029] 2) Then, cool the biodegradable resin composition to 70 °C at a cooling rate of 100 °C / min and then hold in an isothermal state for 100 minutes.

[0030] According to another aspect of the present invention, there is provided a biodegradable nonwoven fabric comprising a biodegradable resin composition, the biodegradable resin composition comprising: a biodegradable resin comprising a first repeating unit derived from a diol having 2 to 4 carbon atoms and a second repeating unit derived from an aliphatic dicarboxylic acid having 2 to 6 carbon atoms; and an inorganic nucleating agent, wherein the biodegradable resin composition has a crystallinity of 15% to 50% measured by differential scanning calorimetry.

[0031] Beneficial effects

[0032] By controlling the monomer type of the biodegradable resin and including an inorganic nucleating agent, the biodegradable resin composition according to the present invention may have a crystallinity in the range of 15% to 50%.

[0033] Therefore, the biodegradable resin composition has a melt flow rate, melting point, isothermal crystallization time, and bond strength that allow it to be made into a nonwoven fabric through a spinning process.

[0034] Thus, the biodegradable resin composition can inhibit the fiber breakage phenomenon during the spinning process.

[0035] In addition, even without rapid quenching after spinning, the biodegradable resin composition does not exhibit fiber-to-fiber fusion, thereby enabling control of the denier of the fiber.

[0036] In addition, fibers made from the biodegradable resin composition can exhibit appropriate drapability, thereby suppressing fiber breakage during the spinning process, and the resulting fibers can have an improved texture.

[0037] In addition, the biodegradable nonwoven fabric made from the biodegradable resin composition is naturally biodegradable at the end of its life, so there is no need to incinerate or emit harmful substances. Brief Description of the Drawings

[0038] Figure 1 Schematically illustrates an apparatus for preparing a biodegradable resin composition according to an embodiment. Detailed Description of the Invention

[0039] The description of the structure or function of the embodiments disclosed in this specification or this application is only shown for the purpose of explaining the embodiments according to the technical idea of the present invention. The embodiments according to the technical idea of the present invention can be implemented in various forms other than the embodiments disclosed in this specification or this application, and should not be construed as the technical idea of the present invention being limited to the embodiments described in this specification or this application.

[0040] In this specification or this application, when "comprising" a certain component, this means including only this component, or this component may further include other components, unless there is a different disclosure. In addition, it should be understood that, unless otherwise specified, in all cases, all numerical ranges representing physical property values, dimensions, etc. of the components described in this specification or this application are modified by the term "about".

[0041] In addition, in this specification or this application, "ppm" is based on weight.

[0042] In addition, in this specification or this application, "derived from" means a component, structure, or substance from the substance itself.

[0043] The following describes a biodegradable resin composition according to the present invention and a biodegradable nonwoven fabric including the same.

[0044] The biodegradable resin composition according to the present invention includes a biodegradable resin, the biodegradable resin including a first repeating unit derived from a diol having 2 to 4 carbon atoms and a second repeating unit derived from an aliphatic dicarboxylic acid having 2 to 6 carbon atoms, and an inorganic nucleating agent, and having a crystallinity of 15% to 50% measured by differential scanning calorimetry.

[0045] The biodegradable resin composition according to the present invention includes a first biodegradable resin. The biodegradable resin includes a first repeating unit derived from a diol having 2 to 4 carbon atoms and a second repeating unit derived from an aliphatic dicarboxylic acid having 2 to 6 carbon atoms.

[0046] The diol may be an aliphatic diol. The diol may be a bio-derived diol. The diol may be at least one selected from the group consisting of ethylene glycol, 1,2-propanediol, 1,3-propanediol, 2-methyl-1,3-propanediol, 1,2-butanediol, 1,4-butanediol, and derivatives thereof.

[0047] Preferably, the diol may include at least one of ethylene glycol and 1,4-butanediol.

[0048] The biodegradable resin including the first repeating unit derived from a diol having 2 to 4 carbon atoms may have appropriate melt flow rate, melting point, isothermal crystallization time, and bonding strength, and thus can be made into a nonwoven fabric by a spinning process.

[0049] The aliphatic dicarboxylic acid may be at least one selected from the group consisting of oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, suberic acid, and derivatives thereof.

[0050] Preferably, the aliphatic dicarboxylic acid may include at least one of succinic acid and adipic acid.

[0051] The biodegradable resin including the second repeating unit derived from an aliphatic dicarboxylic acid having 2 to 6 carbon atoms may have appropriate melt flow rate, melting point, isothermal crystallization time, and bonding strength, so that the fiber breakage phenomenon in the spinning process can be inhibited, and fiber-to-fiber fusion does not occur. Therefore, the denier of the fiber can be controlled.

[0052] The biodegradable resin may further include a third repeating unit derived from an aromatic dicarboxylic acid.

[0053] The aromatic dicarboxylic acid may be at least one selected from the 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'-biphenyldicarboxylic acid, 4,4'-biphenyletherdicarboxylic acid, anthracenedicarboxylic acid, phenanthrenedicarboxylic acid, and derivatives thereof.

[0054] The aromatic dicarboxylic acid may be at least one selected from the group consisting of terephthalic acid, dimethyl terephthalate, 2,6-naphthalenedicarboxylic acid, isophthalic acid, and derivatives thereof.

[0055] Preferably, the aromatic dicarboxylic acid may include terephthalic acid, dimethyl terephthalate, and derivatives thereof.

[0056] A biodegradable resin including a third repeating unit derived from an aromatic dicarboxylic acid may have improved tensile strength and elongation at break.

[0057] The molar ratio of the first repeating unit to the second repeating unit may be from 4:1 to 1:1. The molar ratio of the first repeating unit to the second repeating unit may be from 4:1.5 to 1:1. The molar ratio of the first repeating unit to the second repeating unit may be from 4:2 to 1:1. Preferably, the molar ratio of the first repeating unit to the second repeating unit may be from 4:2.12 to 1:1. When this range is satisfied, the biodegradable resin composition may have improved spinning ability.

[0058] The molar ratio of the first repeating unit to the second repeating unit refers to the molar ratio of the first repeating unit derived from a diol having 2 to 4 carbon atoms to the second repeating unit derived from an aliphatic dicarboxylic acid having 2 to 6 carbon atoms.

[0059] The molar ratio of the first repeating unit to the third repeating unit is from 10:3 to 10:7. The molar ratio of the first repeating unit to the third repeating unit may be from 10:3 to 10:6. The molar ratio of the first repeating unit to the third repeating unit may be from 10:4 to 10:6. Preferably, the molar ratio of the first repeating unit to the third repeating unit may be from 10:4 to 10:5. When this range is satisfied, the nonwoven fabric made from the biodegradable resin composition may have improved tensile strength and elongation at break.

[0060] The molar ratio of the first repeating unit to the third repeating unit refers to the molar ratio of the first repeating unit derived from a diol having 2 to 4 carbon atoms to the third repeating unit derived from an aromatic dicarboxylic acid.

[0061] The molar ratio of the second repeating unit to the third repeating unit may be from 3:2 to 2:3. The molar ratio of the second repeating unit to the third repeating unit may be from 3:2 to 2.5:3. The molar ratio of the second repeating unit to the third repeating unit may be from 3:2 to 3:3. Preferably, the molar ratio of the second repeating unit to the third repeating unit may be from 3:2 to 3:2.8. When this range is satisfied, the biodegradable resin composition may have improved spinning ability, and the nonwoven fabric made from the biodegradable resin composition may have improved tensile strength and elongation at break.

[0062] The molar ratio of the second repeating unit to the third repeating unit refers to the molar ratio of the second repeating unit derived from an aliphatic dicarboxylic acid having 2 to 6 carbon atoms to the third repeating unit derived from an aromatic dicarboxylic acid.

[0063] The biodegradable resin may be poly(butylene adipate terephthalate) (PBAT).

[0064] The biodegradable resin can be polybutylene succinate terephthalate (PBST).

[0065] The biodegradable resin can be polybutylene adipate succinate (PBAS).

[0066] The biodegradable resin can be polybutylene adipate succinate terephthalate (PBAST).

[0067] The biodegradable resin can be polyethylene adipate succinate terephthalate (PEAST).

[0068] The number-average molecular weight of the biodegradable resin can be 30,000 g / mol to 50,000 g / mol, 31,000 g / mol to 50,000 g / mol, 32,000 g / mol to 50,000 g / mol, 33,000 g / mol to 50,000 g / mol, 33,000 g / mol to 45,000 g / mol, 33,000 g / mol to 42,000 g / mol, or 33,000 g / mol to 40,000 g / mol.

[0069] The weight-average molecular weight of the biodegradable resin can be 60,000 g / mol to 100,000 g / mol, 60,000 g / mol to 95,000 g / mol, 60,000 g / mol to 93,000 g / mol, 63,000 g / mol to 93,000 g / mol, 65,000 g / mol to 93,000 g / mol, or 70,000 g / mol to 90,000 g / mol.

[0070] The polydispersity index of the biodegradable resin can be 1.5 to 3.0, 1.8 to 3.0, 2.0 to 2.8, 2.0 to 2.7, 2.0 to 2.6, or 2.0 to 2.5.

[0071] When the number-average molecular weight range, weight-average molecular weight range, and polydispersity index range are satisfied, excellent spinning ability can be provided and the tensile strength can be improved.

[0072] The number-average molecular weight, weight-average molecular weight, and polydispersity index of the biodegradable resin can be measured under the following conditions:

[0073] - Analytical instrument: Agilent 1260 Infinity

[0074] Detector: Agilent G1362ARI-detector

[0075] - Column type: Waters HR4THF 7.8X 300mm

[0076] - Solvent: THF

[0077] - Temperature: 40 °C.

[0078] - Flow rate: 1 mL / min

[0079] - Concentration: 4 mg / mL

[0080] The biodegradable resin composition according to the present invention includes an inorganic nucleating agent. The inorganic nucleating agent may refer to a nucleating agent composed of an inorganic compound. Since the biodegradable resin composition includes an inorganic nucleating agent, the crystallization rate can be improved so that fiber-to-fiber fusion can be suppressed during the spinning process, thereby enabling denier control. In addition, during the production of nonwoven fabrics, a uniform nano-scale fiber phase can be formed, and bead formation can be suppressed.

[0081] The inorganic nucleating agent may include one or more selected from the group consisting of: titanium dioxide, talc, kaolinite, montmorillonite, mica, clay, zeolite, silica, graphite, carbon black, mica, barium sulfate, calcium silicate, calcium carbonate, calcium sulfide, calcium titanate, zinc oxide, aluminum oxide, magnesium oxide, neodymium oxide, and boron nitride. Preferably, the inorganic nucleating agent may include titanium dioxide (TiO2). As the titanium dioxide, at least one of fully dull (FD) TiO2 having almost no gloss and semi-dull (SD) TiO2 having a slight gloss can be used.

[0082] Based on the total weight of the biodegradable resin composition, the content of the inorganic nucleating agent may be 10 ppm to 10,000 ppm, 100 ppm to 10,000 ppm, 300 ppm to 10,000 ppm, 500 ppm to 10,000 ppm, 500 ppm to 5,000 ppm, or 1,000 ppm to 3,000 ppm. When within this range, the crystallinity of the biodegradable resin composition can be adjusted within the range of 15% to 50%, thereby suppressing the fiber breakage phenomenon during the spinning process and enabling the spinning process to proceed smoothly.

[0083] The biodegradable resin composition may include nanocellulose having an average length of 10 nm to 300 nm, 10 nm to 200 nm, 20 nm to 200 nm, or 30 nm to 200 nm. Based on the total weight of the biodegradable resin composition, the content of the nanocellulose may be 10 ppm to 500 ppm, 50 ppm to 500 ppm, 50 ppm to 300 ppm, or 50 ppm to 200 ppm. When this range is satisfied, the crystallization rate can be increased so that fiber-to-fiber fusion can be suppressed during the spinning process, thereby enabling denier control.

[0084] The nanocellulose may be subjected to bead mill pretreatment or ultrasonic pretreatment. The nanocellulose may be subjected to bead mill pretreatment and ultrasonic pretreatment. The nanocellulose is preferably ultrasonically pretreated after bead mill pretreatment, which can prevent re-aggregation and thus improve dispersibility.

[0085] A vertical mill or a horizontal mill may be used as wet grinding equipment for bead mill pretreatment. The horizontal mill is preferred because it can fill a larger amount of beads inside the chamber, reduce uneven wear of the machine, reduce bead wear, and make maintenance easier, but the present invention is not limited thereto.

[0086] The bead mill pretreatment may be carried out using beads made of one or more selected from the group consisting of zircon, zirconia, quartz, and alumina.

[0087] The bead mill pretreatment may be carried out using beads having a diameter of about 0.3 mm to about 1 mm. For example, the diameter of the beads may be about 0.3 mm to about 0.9 mm, about 0.4 mm to about 0.8 mm, about 0.45 mm to about 0.7 mm, or about 0.45 mm to about 0.6 mm. When this range is satisfied, the nanocellulose may have improved dispersibility.

[0088] Ultrasonic pretreatment is a method of physically breaking or pulverizing nanoparticles by waves generated by emitting 20 kHz ultrasonic waves into a solution.

[0089] The ultrasonic pretreatment may be carried out for less than 30 minutes at an output of 30,000 J / s or less. For example, the ultrasonic pretreatment may be carried out for 25 minutes or less, 20 minutes or less, or 18 minutes or less at an output of 25,000 J / s or less or 22,000 J / s or less. When this range is satisfied, the ultrasonic pretreatment effect, i.e., the improvement in dispersibility, can be maximized.

[0090] The biodegradable resin composition may include a branching agent, which includes at least one of a trivalent or higher alcohol and a trivalent or higher carboxylic acid. The branching agent may react with a diol, an aliphatic dicarboxylic acid, and / or an aromatic dicarboxylic acid. The branching agent may be included as part of the molecular structure of the biodegradable resin.

[0091] The trivalent or higher alcohol may be at least one selected from the group consisting of glycerol, pentaerythritol, and trimethylolpropane.

[0092] The trivalent or higher carboxylic acid may be at least one selected from the group consisting of: methanetricarboxylic acid, ethanetricarboxylic acid, citric acid, benzene-1,3,5-tricarboxylic acid, 5-sulfo-1,2,4-benzenetricarboxylic acid, ethane-1,1,2,2-tetracarboxylic acid, propane-1,1,2,3-tetracarboxylic acid, butane-1,2,3,4-tetracarboxylic acid, cyclopentane-1,2,3,4-tetracarboxylic acid, and benzene-1,2,4,5-tetracarboxylic acid.

[0093] Preferably, the branching agent may include glycerol.

[0094] Based on the total weight of the biodegradable resin composition, the content of the branching agent may be 500 ppm to 3,000 ppm, 700 ppm to 3,000 ppm, 700 ppm to 2,500 ppm, or 1,000 ppm to 2,000 ppm. When this range is satisfied, the nonwoven fabric made from the biodegradable resin composition may have appropriate biodegradability and improved mechanical properties.

[0095] The biodegradable resin composition may include a heat stabilizer. The heat stabilizer may be at least one selected from the group consisting of: phosphorus / amine-based high-temperature heat stabilizers such as tetraethylenepentamine, triethyl phosphonoacetate, phosphoric acid, phosphorous acid, polyphosphoric acid, trimethyl phosphate (TMP), triethyl phosphate, trimethylphosphine, triphenylphosphine, etc.

[0096] Preferably, the heat stabilizer may include triethyl phosphonoacetate.

[0097] Based on the total weight of the biodegradable resin composition, the content of the heat stabilizer may be 10 ppm to 3,000 ppm, 20 ppm to 2,000 ppm, 20 ppm to 1,500 ppm, or 20 ppm to 1,000 ppm. When this range is satisfied, the polymer degradation caused by high temperature during the reaction can be controlled, thereby reducing the end groups of the polymer and improving the color.

[0098] The biodegradable resin composition may include a lubricant.

[0099] The lubricant may include at least one selected from the group consisting of: fatty acid-based lubricants, including stearic acid; fatty alcohol-based lubricants; fatty amide-based lubricants, including stearamide, n-butyl stearate, and methyl hydroxystearate; fatty ester-based lubricants, such as polyol fatty acid esters, saturated fatty acid esters, or ester-based waxes; and fatty acid metal soap-based lubricants.

[0100] Preferably, the lubricant may be a stearic acid-based lubricant and may include at least one selected from the group consisting of calcium stearate, zinc stearate, barium stearate, magnesium stearate, glycerol stearate, and butyl stearate.

[0101] Preferably, the lubricant may be a wax-based lubricant and may include N,N-ethylenebisstearamide.

[0102] The lubricant reduces the heat generated by friction during the mixing, melting, and processing of the raw materials, and has an excellent dispersion effect on biodegradable resins relative to its price, and has an excellent lubrication effect, thereby improving the manufacturing efficiency.

[0103] Based on the total weight of the biodegradable resin composition, the content of the stearic acid-based lubricant may be 1,000 ppm to 10,000 ppm, 1,000 ppm to 8,000 ppm, 3,000 ppm to 8,000 ppm, or 4,000 ppm to 6,000 ppm.

[0104] Based on the total weight of the biodegradable resin composition, the content of the wax-based lubricant may be 1,000 ppm to 10,000 ppm, 1,000 ppm to 8,000 ppm, 3,000 ppm to 8,000 ppm, or 4,000 ppm to 6,000 ppm.

[0105] When within this range, the polymer degradation caused by high temperature during the reaction process can be controlled, so that the end groups of the polymer can be reduced and the color can be improved.

[0106] The biodegradable resin composition may have a crystallinity of 15% to 50% measured by differential scanning calorimetry.

[0107] Preferably, the biodegradable resin composition may have a crystallinity of 15% to 50%, 15% to 40%, 15% to 30%, or 15% to 25%. When within this range, the phenomenon of fiber breakage in the spinning process can be suppressed, and fiber-to-fiber fusion does not occur, thereby enabling the control of the denier of the fiber.

[0108] The crystallinity can be calculated by the following calculation formula, in which the crystal melting energy value and crystal formation energy value measured by differential scanning calorimetry are used:

[0109] [Calculation formula]

[0110] Degree of crystallinity (%) = [(Energy required to melt 1 g of the biodegradable resin composition (crystal melting energy (J / g) - crystal formation energy (J / g))) / Energy required to melt 1 g of a biodegradable resin composition with 100% crystallinity (J / g)] × 100

[0111] When the biodegradable resin composition is within the crystallinity range according to the calculation method, this can mean that the biodegradable resin composition has such a crystallinity that it can be made into a nonwoven fabric by a spinning process and can simultaneously suppress fiber-to-fiber fusion and fiber breakage occurring in the spinning process.

[0112] The crystallinity of the biodegradable resin composition can be controlled according to the types and contents of the above-mentioned diols, aliphatic dicarboxylic acids, and aromatic dicarboxylic acids, and whether an inorganic nucleating agent is included.

[0113] As measured under the conditions of 190 °C and 2.16 kg, the biodegradable resin composition can have a melt flow rate of 10 g / 10 min to 25 g / 10 min, 10 g / 10 min to 20 g / 10 min, 10 g / 10 min to 15 g / 10 min, or 11 g / 10 min to 15 g / 10 min.

[0114] As measured under the conditions of 230 °C and 2.16 kg, the biodegradable resin composition can have a melt flow rate of 20 g / 10 min to 50 g / 10 min, 25 g / 10 min to 50 g / 10 min, 25 g / 10 min to 40 g / 10 min, or 29 g / 10 min to 39 g / 10 min.

[0115] When these ranges are met, the amount of the biodegradable resin composition discharged during the spinning process is uniform, so that excellent spinning ability can be achieved, the yarns of the biodegradable nonwoven fabric made from the biodegradable resin composition do not break, and the tensile strength and elongation can be improved.

[0116] According to the following Measuring Method 1, the biodegradable resin composition can have an adhesion strength of 5 kgf or less, 4.5 kgf or less, 4.4 kgf or less, or from 0.2 kgf or more to 4.4 kgf or less. When this range is met, the fibers made from the biodegradable resin composition do not fuse or break with each other after the spinning process.

[0117] [Measuring Method 1]

[0118] 1) Compress the biodegradable resin composition at a pressure of 10 MPa at 210 °C for 3 minutes to produce a sheet having a width of 20 mm, a length of 100 mm and a thickness of 0.3 mm;

[0119] 2) Place two sheets with a length of 75 mm horizontally face to face, and then bond them at a pressure of 5 MPa at 90 °C for 10 minutes;

[0120] 3) To measure the bond strength of the two bonded sheets, conduct a 180° lap shear test at a tensile speed of 100 mm / min.

[0121] The bond strength can be controlled according to the types and contents of the above-mentioned diol, aliphatic dicarboxylic acid and aromatic dicarboxylic acid, and whether an inorganic nucleating agent is included.

[0122] As measured by the following Measuring Method 2, the biodegradable resin composition can have an isothermal crystallization time of 10 seconds to 300 seconds, 50 seconds to 300 seconds, 100 seconds to 300 seconds, or 114 seconds to 186 seconds at 70 °C. When this range is satisfied, the fibers made of the biodegradable resin composition will not fuse or break with each other after the spinning process.

[0123] [Measuring Method 2]

[0124] 1) Heat the biodegradable resin composition to 220 °C at a heating rate of 10 °C / min, and then hold for 5 minutes;

[0125] 2) Then, cool the biodegradable resin composition to 70 °C at a cooling rate of 100 °C / min, and then hold in an isothermal state for 100 minutes;

[0126] 3) Measure the total area half-time of the crystallization peak of the biodegradable resin composition using differential scanning calorimetry.

[0127] The isothermal crystallization time refers to the time required to rapidly cool a polymer in a molten state and evaluate it until crystallization.

[0128] A short isothermal crystallization time indicates that crystallization proceeds quickly. Rapid crystallization can mean that molecular motion is inhibited and crystals are formed in a rapid stage after cooling.

[0129] The isothermal crystallization time can be controlled according to the types and contents of the above-mentioned diol, aliphatic dicarboxylic acid and aromatic dicarboxylic acid, and whether an inorganic nucleating agent is included.

[0130] The biodegradable resin composition may have a melting temperature. The melting temperature of the biodegradable resin composition may be 120°C to 200°C, 130°C to 200°C, 150°C to 200°C, or 150°C to 190°C. When within this range, the biodegradable nonwoven fabric made from the biodegradable resin composition may have improved tensile strength and elongation.

[0131] The maximum load of the biodegradable resin composition may be 2 kgf to 5 kgf, 2.5 kgf to 5 kgf, 3 kgf to 5 kgf, or 4 kgf to 4.8 kgf.

[0132] The yield strength of the biodegradable resin composition may be 0.5 Mpa to 8 Mpa, 0.5 Mpa to 7 Mpa, 1 Mpa to 7 Mpa, 1.2 Mpa to 7 Mpa, or 1.2 Mpa to 5.4 Mpa.

[0133] The elongation of the biodegradable resin composition may be 300% to 700%, 350% to 700%, 400% to 700%, 450% to 700%, or 500% to 700%.

[0134] The maximum load, yield strength, and elongation of the biodegradable resin composition may be indicators representing the bonding strength of the biodegradable resin composition. The maximum load, yield strength, and elongation of the biodegradable resin composition may depend on the content of the inorganic nucleating agent included in the biodegradable resin composition. When within this range, the bonding force of the spun biodegradable resin composition may be reduced, so that a uniform nano-sized fiber phase can be formed, and bead formation in the biodegradable nonwoven fabric can be inhibited.

[0135] The method for manufacturing a biodegradable nonwoven fabric according to the present invention may include: a step of spinning a biodegradable resin composition to manufacture a biodegradable yarn, a step of cooling the biodegradable yarn, and a step of combining the cooled biodegradable yarns to form a biodegradable yarn web.

[0136] Figure 1 Schematically shows an apparatus for preparing a biodegradable resin composition according to the first embodiment. Refer to Figure 1 , the apparatus may include a slurry stirrer 100, an esterification reaction section 200, a polycondensation reaction section 300, a post-treatment section 400, a first recovery section 510, and a second recovery section 520.

[0137] The step of preparing the biodegradable resin composition may include a step of preparing a first slurry including the above-mentioned diol and aromatic dicarboxylic acid.

[0138] The step of preparing the biodegradable resin composition may include the step of preparing a second slurry including the above-mentioned diol and aliphatic dicarboxylic acid.

[0139] In the step of preparing the first slurry, the diol and the aromatic dicarboxylic acid are fed into the slurry stirrer 100 and stirred to prepare the first slurry. By mixing and pre-treating the diol and the aromatic dicarboxylic acid to form a slurry, the diol and the aromatic dicarboxylic acid can react uniformly, and this can effectively and rapidly carry out the esterification reaction, thereby improving the reaction efficiency. In particular, when the aromatic dicarboxylic acid such as terephthalic acid has complete crystallinity and is in powder form, its solubility in the diol is extremely low, making it difficult to undergo a homogeneous reaction. Therefore, the pre-treatment process of pulping can play a very important role in achieving the excellent physical properties of the biodegradable nonwoven fabric according to the present invention.

[0140] When the aromatic dicarboxylic acid is terephthalic acid, terephthalic acid has perfect crystallinity and is a white crystal, which sublimes at about 300 °C under normal pressure without a melting point, so its solubility in the diol is extremely low, making it difficult to undergo a homogeneous reaction. Therefore, if a pre-treatment process is carried out before the first esterification reaction, a uniform reaction can be induced by increasing the surface area of reaction with the diol within the solid matrix of terephthalic acid.

[0141] When the aromatic dicarboxylic acid is dimethyl terephthalic acid, dimethyl terephthalic acid can react with the diol in a molten state at about 142 °C to 170 °C through the pre-treatment process. Therefore, the esterification reaction can proceed faster and more effectively.

[0142] In the pre-treatment step of preparing the first slurry, the structure and properties of the biodegradable resin composition can vary according to the particle size, particle size distribution, pre-treatment reaction conditions, etc. of the aromatic dicarboxylic acid.

[0143] The aromatic dicarboxylic acid may include terephthalic acid. In the particle size distribution (PSD), the average particle size (D50) of terephthalic acid may be 10 μm to 400 μm, measured by a particle size analyzer Microtrac S3500, and may have a standard deviation of 100 or less for the average particle size (D50). The standard deviation means the square root of the variance. The average particle size (D50) of terephthalic acid may be 20 μm to 200 μm, 30 μm to 180 μm, or 50 μm to 150 μm. When the average particle size (D50) of terephthalic acid satisfies these ranges, it may be more advantageous in terms of improving the solubility and reaction rate in the diol.

[0144] In the pre-treatment process, the diol and the aromatic dicarboxylic acid can be mixed and fed into the slurry stirrer (tank) 100.

[0145] The slurry stirrer 100 may have an anchor-shaped bottom and a height of 20 mm or more from the stirrer. In addition, the slurry stirrer 100 may be equipped with two or more rotating blades, which may be more advantageous in achieving an effective stirring effect.

[0146] The height from the slurry stirrer 100 may be 20 mm or more, that is, the supply pipeline and the bottom of the stirrer may be almost connected to each other. In this case, the slurry can be obtained without precipitation. If the shape, form, and rotating blades of the stirrer do not meet the above conditions, the aromatic dicarboxylic acid may deposit on the bottom when the diol and the aromatic dicarboxylic acid are initially mixed. In this case, phase separation may occur.

[0147] The pretreatment process for preparing the first slurry may include the following steps: mixing the diol and the aromatic dicarboxylic acid, and stirring at about 50 rpm to about 200 rpm for 10 minutes or more, or 10 minutes to 200 minutes at about 30 °C to about 100 °C.

[0148] The diol may have the above characteristics.

[0149] The diol may be added all at once or in portions. The diol may be added separately when mixing with the aromatic dicarboxylic acid and when mixing with the aliphatic dicarboxylic acid. The aromatic dicarboxylic acid may have the above characteristics.

[0150] In the step of preparing the second slurry, the aromatic dicarboxylic acid is not used.

[0151] The diol and the aliphatic dicarboxylic acid can be fed into the slurry stirrer 100 and stirred therein to produce the second slurry.

[0152] The pretreatment step for preparing the second slurry may include the following steps: mixing the diol and the aliphatic dicarboxylic acid and mixing them at about 50 rpm to about 200 rpm for 10 minutes or more, or 10 minutes to 200 minutes at about 30 °C to about 100 °C.

[0153] The diol may have the above characteristics.

[0154] The diol can be added in batches or portions. The diol can be added in portions when mixing with the aliphatic dicarboxylic acid. The aliphatic dicarboxylic acid may have the above characteristics.

[0155] This step may include the step of preparing a prepolymer after the esterification reaction. The step of preparing the prepolymer may be carried out in the esterification reaction section 200.

[0156] After adding an aliphatic dicarboxylic acid or a mixture of a diol and an aliphatic dicarboxylic acid to the first slurry or the second slurry, the esterification reaction can be carried out in batches. That is to say, the first slurry or the second slurry can be fed into an esterification reactor, and only the aliphatic dicarboxylic acid or the mixture of the aliphatic dicarboxylic acid and the diol can be fed into the esterification section 200 to carry out the esterification reaction.

[0157] The esterification reaction can be carried out at about 250 °C or lower for about 0.5 hour to about 5 hours.

[0158] The esterification reaction can be carried out at about 180 °C to about 250 °C, about 185 °C to about 240 °C or about 200 °C to about 240 °C under normal pressure or reduced pressure until the by-product water reaches 95% theoretically.

[0159] The esterification reaction can be carried out for 0.5 hour to 5.5 hours, 0.5 hour to 4.5 hours or 1 hour to 4 hours, but the present invention is not limited thereto.

[0160] The first slurry or the second slurry can be mixed with at least one of a polycarbonate diol and a polyether polyol, and then the first esterification reaction can be carried out. Alternatively, at least one of the polycarbonate diol and the polyether polyol can be added to the second esterification reaction.

[0161] After the first esterification reaction, the mixture of the aliphatic dicarboxylic acid and the diol can be fed into the esterification section 200 and can be subjected to a second esterification reaction together with the product of the first esterification reaction. In addition, at least one of the polycarbonate diol and the polyether polyol can be added during the second esterification reaction.

[0162] The first esterification reaction can be carried out at 250 °C or lower for 1.25 hours to 4 hours.

[0163] The first esterification reaction can be carried out at 180 °C to 250 °C, 185 °C to 240 °C or 200 °C to 240 °C under normal pressure or reduced pressure until the by-product water reaches 95% theoretically.

[0164] The first esterification reaction can be carried out for 1.25 hours to 4 hours, 1.25 hours to 3.5 hours or 2.5 hours to 3 hours, but the present invention is not limited thereto.

[0165] The second esterification reaction can be carried out at about 250 °C or lower for 0.25 hour to 3.5 hours. In particular, the second esterification reaction can be carried out at 180 °C to 250 °C, 185 °C to 240 °C or 200 °C to 240 °C under normal pressure or reduced pressure until the water as a by-product reaches 95% theoretically.

[0166] The second esterification reaction can be carried out for 0.5 hours to 3 hours, 1 hour to 2.5 hours, or 1.5 hours to 2.5 hours, but the present invention is not limited thereto.

[0167] When the esterification reaction is divided into a first esterification reaction and a second esterification reaction, the entire esterification reaction can be precisely controlled. When the esterification reaction is separated, the reaction stability and reaction uniformity of the esterification reaction can be improved.

[0168] Through the esterification reaction, a second prepolymer can be formed.

[0169] The number average molecular weight of the prepolymer can be about 500 g / mol to about 10,000 g / mol. The number average molecular weight of the prepolymer can be about 500 g / mol to about 8,500 g / mol, about 500 g / mol to about 8,000 g / mol, about 500 g / mol to about 7,000 g / mol, about 500 g / mol to about 5,000 g / mol, or about 800 g / mol to about 3,000 g / mol. When this range is satisfied, the molecular weight of the polymer can be effectively increased in the polycondensation reaction.

[0170] The number average molecular weight can be measured using gel permeation chromatography (GPC). In particular, the data obtained by gel permeation chromatography includes several items such as Mn, Mw, and Mp, but among them, the number average molecular weight (Mn) can be used as a standard to measure the molecular weight.

[0171] The above-mentioned branching agent can be fed into the esterification reaction section 200 during the esterification reaction.

[0172] In the esterification reaction, a titanium-based catalyst and / or a germanium-based catalyst can be used. In particular, the titanium-based catalyst and / or the germanium-based catalyst can be added to the first slurry or the second slurry, and the esterification reaction can be carried out.

[0173] Before the first esterification reaction, the titanium-based catalyst and / or the germanium-based catalyst can be added to the first slurry or the second slurry, and the titanium-based catalyst and / or the germanium-based catalyst can be further added to the product of the first esterification reaction.

[0174] Based on the total weight of the diol, aromatic dicarboxylic acid, and aliphatic dicarboxylic acid, the content of the catalyst can be about 100 ppm to 2,000 ppm. For example, the content of the included titanium-based catalyst or germanium-based catalyst can be about 100 ppm to about 1,600 ppm, about 150 ppm to about 1,400 ppm, about 200 ppm to about 1,200 ppm, or about 250 ppm to about 1,100 ppm. When the content of the catalyst satisfies this range, the performance can be further improved.

[0175] Before the esterification reaction, the above heat stabilizer can be added together with the slurry. The heat stabilizer can be fed into the esterification section 200 during the esterification reaction. After the esterification reaction, the heat stabilizer can be added to the product of the esterification reaction. In addition, the heat stabilizer can be added together with the aliphatic dicarboxylic acid. Further, after the first esterification reaction and before the second esterification reaction, the heat stabilizer can be fed into the esterification section 200.

[0176] The heat stabilizer can have the same characteristics as those described above.

[0177] After the completion of the esterification, one or more selected from the group consisting of additives such as silica, potassium or magnesium and color correctors such as cobalt acetate can be further added to the esterification product. That is, after the completion of the esterification, the additives and / or color correctors can be added and stabilized, and then the polycondensation reaction can be carried out. The additives and / or color correctors can be added after the completion of the esterification reaction and can be fed together with the prepolymer into the polycondensation section 300.

[0178] After the completion of the esterification reaction, the above inorganic nucleating agent can be added to the product of the esterification reaction. That is, after the completion of the esterification reaction, then the inorganic nucleating agent is added and stabilized, and the polycondensation reaction can be carried out. The inorganic nucleating agent has the same characteristics as those described above. The inorganic nucleating agent can be fed together with the prepolymer into the polycondensation section 300 and the polycondensation process can be carried out. Thus, the inorganic nucleating agent can be uniformly dispersed in the biodegradable resin.

[0179] The first recovery section 510 can recover by-products such as water from the esterification section 200. The first recovery section 510 can recover the by-products generated by the esterification by applying a vacuum pressure to the esterification section 200 or by performing reflux.

[0180] This step can include the step of polycondensing the prepolymer. The polycondensation reaction can be carried out as follows. The prepolymer can be fed into the polycondensation section 300. In addition, the heat stabilizer can be fed together with the prepolymer into the polycondensation section 300.

[0181] The polycondensation reaction can be carried out at about 180 °C to about 280 °C and at about 10 Torr or less for about 1 hour to about 5 hours. For example, the polycondensation reaction can be carried out at about 190 °C to about 270 °C, about 210 °C to about 260 °C or about 230 °C to about 255 °C, can be carried out at about 0.9 Torr or less, about 0.7 Torr or less, about 0.2 Torr to about 10 Torr, about 0.3 Torr to about 0.9 Torr or about 0.4 Torr to about 0.6 Torr, and can be carried out for about 1.5 hours to about 5 hours, about 2 hours to about 4.5 hours or about 2 hours to about 4 hours.

[0182] The polycondensation reaction can include a first polycondensation and a second polycondensation.

[0183] The first polycondensation can be carried out at about 260 °C or lower, about 250 °C or lower, about 215 °C to about 250 °C, about 215 °C to about 245 °C or about 230 °C to about 245 °C at about 1 Torr to about 200 Torr, about 2 Torr to about 100 Torr, about 4 Torr to about 50 Torr, about 5 Torr to about 45 Torr or about 8 Torr to about 32 Torr for about 0.5 hours to about 3.5 hours, about 0.5 hours to about 3.0 hours or about 0.5 hours to about 2.8 hours.

[0184] The second polycondensation can be carried out at about 220 °C to about 265 °C, about 230 °C to about 260 °C or about 235 °C to about 255 °C at about 1 Torr or less, about 0.8 Torr or less, about 0.6 Torr or less, about 0.1 Torr to about 1 Torr, about 0.3 Torr to about 0.8 Torr or about 0.4 Torr to about 0.6 Torr for about 0.5 hours to about 4 hours, about 1 hour to about 3.5 hours or about 1.5 hours to about 3.5 hours.

[0185] Before the polycondensation reaction, a titanium-based catalyst or a germanium-based catalyst can be further added to the prepolymer. In addition, before the polycondensation reaction, one or more selected from the group consisting of: additives such as silica, potassium or magnesium; phosphorus / amine stabilizers such as trimethyl phosphate, triphenyl phosphate, trimethylphosphine, phosphoric acid, phosphorous acid or tetraethylenepentamine; and polymerization catalysts such as antimony trioxide or tetrabutyl titanate can be further added to the prepolymer.

[0186] The number average molecular weight of the polymer can be about 40,000 g / mol or more. The number average molecular weight of the polymer can be about 43,000 g / mol or more, about 45,000 g / mol or more or about 50,000 g / mol to about 70,000 g / mol. When this range is satisfied, the physical properties, impact resistance, durability and formability can all be further improved.

[0187] The second recovery unit 520 can recover by-products such as water from the polycondensation reaction unit 300. The second recovery unit 520 can apply a vacuum pressure to the polycondensation reaction unit 300, and can recover the by-products generated in the polycondensation reaction.

[0188] The second recovery unit 520 can apply a vacuum pressure of about 0.1 Torr to about 1 Torr to the inside of the polycondensation reaction unit 300. The second recovery unit 520 can apply a vacuum pressure of about 0.1 Torr to about 0.9 Torr to the inside of the polycondensation reaction unit 300.

[0189] A chain extender can be added to the polymer. The polymer and the chain extender can be uniformly mixed and held at about 200 °C to about 260 °C for about 1 minute to about 15 minutes.

[0190] This step may include the step of manufacturing pellets from a polymer. In particular, the polymer can be cooled to about 15 °C or lower, about 10 °C or lower, or about 6 °C or lower, and then the cooled polymer can be cut and manufactured into pellets. The cutting step can be carried out using any pellet cutting machine used in the art without limitation, and the pellets can have various shapes. As a method of cutting pellets, an underwater cutting method or a strand cutting method can be used. The pellets can undergo an additional post-treatment process.

[0191] The pellets can be fed into the post-treatment section 400, and a post-treatment process can be carried out. The post-treatment process can be carried out in the post-treatment section 400. The pellets can be fed into the post-treatment section 400. Next, the post-treatment section 400 can melt the input pellets by frictional heat and re-extrude them. That is, the post-treatment section 400 can include an extruder such as a twin-screw extruder. The temperature of the post-treatment process can be about 230 °C to about 270 °C. The temperature of the post-treatment process can be about 230 °C to about 260 °C. The temperature of the post-treatment process can be about 240 °C to about 265 °C. The temperature of the post-treatment process can be about 240 °C to about 260 °C. The time of the post-treatment process can be about 30 seconds to about 3 minutes. The time of the post-treatment process can be about 50 seconds to about 2 minutes. The time of the post-treatment process can be about 1 minute to about 2 minutes. Next, the resin extruded from the extruder can be cooled, cut, and processed into post-treated pellets. That is, the resin extruded from the extruder can be reprocessed into pellets through the above cutting step.

[0192] The prepared biodegradable resin composition can be manufactured into biodegradable yarns through a spinning process.

[0193] The spinning process may include the process of melting the biodegradable resin composition and introducing it into a spinning assembly. In the spinning assembly, the molten biodegradable resin composition can be spun from the nozzles of the extruder. Through the spinning assembly, filaments of the biodegradable resin composition can be formed. The filaments can be cooled, solidified, and crystallized to produce unstretched biodegradable yarns.

[0194] Multiple nozzles can be provided. The number of nozzles can be 2 to 30, 10 to 30, or 18 to 30. Through the multiple nozzles, multiple filaments can be produced from the biodegradable resin composition. The pressure of the nozzles can be about 220 °C 80 kg / cm 2 to 120 kg / cm 2 、90 kg / cm 2 to 120 kg / cm 2 、90 kg / cm 2 to 110 kg / cm 2 or 95 kg / cm 2Up to 105 kg / cm 2 The spinning temperature in the spinning pack can be from 180°C to 250°C, from 190°C to 250°C, from 190°C to 240°C or from 190°C to 230°C.

[0195] The biodegradable resin composition in the spinning process can have a melt flow rate within a specific range.

[0196] As measured under the conditions of 190°C and 2.16 kg, the biodegradable resin composition can have a melt flow rate of 10 g / 10 min to 25 g / 10 min, 10 g / 10 min to 20 g / 10 min, 10 g / 10 min to 15 g / 10 min or 11 g / 10 min to 15 g / 10 min.

[0197] As measured under the conditions of 230°C and 2.16 kg, the biodegradable resin composition can have a melt flow rate of 20 g / 10 min to 50 g / 10 min, 25 g / 10 min to 50 g / 10 min, 25 g / 10 min to 40 g / 10 min or 29 g / 10 min to 39 g / 10 min.

[0198] When these ranges are met, the amount of the biodegradable resin composition discharged during the spinning process is uniform, so that excellent spinning ability can be provided. The yarns of the biodegradable nonwoven fabric made from the biodegradable resin composition can be unbroken, and the tensile strength and elongation can be improved.

[0199] This step can include the step of cooling the biodegradable yarn.

[0200] The biodegradable yarn can be an unstretched biodegradable yarn produced from the biodegradable resin composition.

[0201] The cooling can be carried out at about 1°C to 15°C, 1°C to 13°C, 2°C to 13°C or 5°C to 13°C. The cooling can be carried out in a quenching chamber. The length of the quenching chamber can be about 1 m to 5 m, about 1 m to 4 m, about 1 m to 3 m or about 1 m to 2 m.

[0202] When this range is met, the phenomenon that adjacent unstretched biodegradable yarns fuse together can be inhibited.

[0203] This step can include the step of stretching the cooled biodegradable yarn.

[0204] Through the stretching process, biodegradable yarns can be produced that are stretched 1.1 to 3 times, 1.2 to 3 times, 1.2 to 2.7 times, 1.2 to 2.6 times, or 1.2 to 2.5 times compared to the non-stretched biodegradable yarns.

[0205] If desired, the stretched biodegradable yarns can be heat-treated at an appropriate temperature.

[0206] The stretched biodegradable yarns can be wound. The stretched biodegradable yarns can be wound through a winder. The winding speed of the winder can be 300 m / min to 3,000 m / min, 300 m / min to 2,500 m / min, 400 m / min to 2,500 m / min, 500 m / min to 2,500 m / min, or 250 m / min to 2,000 m / min. When within this range, the phenomenon of the biodegradable yarns fusing with each other or breaking can be suppressed.

[0207] The tensile strength of the biodegradable yarns can be 0.5 g / de to 5.0 g / de, 0.5 g / de to 4.0 g / de, 1.0 g / de to 4.0 g / de, or 1.0 g / de to 3.0 g / de. The elongation at break of the biodegradable yarns can be 20% to 400%, 20% to 300%, 25% to 300%, 25% to 250%, 30% to 250%, or 35% to 200%. The tensile strength of the biodegradable yarns can be 1.0 g / de to 3.0 g / de, and its elongation at break can be 35% to 200%. When within this range, the biodegradable yarns are easily compressed together, so they can be easily applied to biodegradable nonwoven fabrics, and the mechanical strength of the biodegradable nonwoven fabrics can be improved.

[0208] The average diameter of the biodegradable yarns can be 1 μm to 500 μm, 1 μm to 400 μm, 1 μm to 300 μm, 1 μm to 200 μm, or 10 μm to 100 μm. When within this range, the biodegradable yarns can be easily pressed together and easily used as biodegradable nonwoven fabrics, and the mechanical strength of the biodegradable nonwoven fabrics can be improved.

[0209] This step can include the step of combining the cooled biodegradable yarns to form a biodegradable yarn web.

[0210] The method of combining the biodegradable yarns can be carding, air-laying, aqueous suspension, or spunbond process.

[0211] The carding process may refer to a process of stacking biodegradable yarns on a collector using a device including multiple gears to form a biodegradable yarn web.

[0212] The air-laying process may refer to a process of arranging biodegradable yarns on a collector using a device pushed by an air current to form a biodegradable yarn web.

[0213] The aqueous suspension process may refer to a process of dispersing biodegradable yarns in water, conveying them on a wire mesh sieve or a perforated drum, and then sucking, pressing, and drying the residual moisture of the transferred biodegradable yarns to form a biodegradable yarn web.

[0214] The spunbond process may refer to a process of forming a Venturiweb of biodegradable yarns on a collector and then forming a biodegradable yarn web.

[0215] This step may further include the step of combining the biodegradable yarn web by at least one process of needlepunching, hydroentangling, stitchbonding, calendering, and air-through bonding.

[0216] Through this process, the bonding force between the biodegradable yarn webs can be enhanced, the tensile strength and elongation can be improved, and the biodegradable nonwoven fabric can be prevented from fuzzing.

[0217] The needlepunching process may refer to a process in which needles penetrate the biodegradable yarn web and the biodegradable yarns are entangled with each other through the barbs of the needles.

[0218] The hydroentangling process may refer to a process of combining the biodegradable yarn web by spraying high-pressure water flow on one side and absorbing the high-pressure water flow on the other side.

[0219] The stitchbonding process may refer to a process of connecting the biodegradable yarn web by sewing threads and needles.

[0220] The calendering process may refer to a process of pressing the biodegradable yarn web and then thermally curing it.

[0221] The air-through bonding process may refer to a process of bonding the biodegradable yarn web by high-temperature hot air.

[0222] The biodegradable nonwoven fabric according to the present invention can be manufactured by these processes.

[0223] The biodegradable nonwoven fabric comprises a biodegradable resin composition which includes a first repeating unit derived from a diol having 2 to 4 carbon atoms and a second repeating unit derived from an aliphatic dicarboxylic acid having 2 to 6 carbon atoms, as well as an inorganic nucleating agent, and the biodegradable resin composition has a crystallinity of 15% to 50% measured by differential scanning calorimetry.

[0224] The biodegradable nonwoven fabric is lightweight and has excellent strength, a high surface area and porosity, so it can be applied to products requiring hygroscopicity.

[0225] The biodegradable nonwoven fabric may include yarns having an average diameter of 1 μm to 500 μm, 1 μm to 400 μm, 1 μm to 300 μm, 1 μm to 200 μm or 10 μm to 100 μm.

[0226] The biodegradable nonwoven fabric can be treated. The biodegradable nonwoven fabric can be treated with an antistatic agent to prevent static electricity. The biodegradable nonwoven fabric can be waterproofed with a hydrophobic material. The biodegradable nonwoven fabric can be antibacterial-treated with an antibacterial material.

[0227] The biodegradable nonwoven fabric can be embossed. The biodegradable nonwoven fabric can be printed. The biodegradable nonwoven fabric can be embossed or printed to a thickness and size suitable for the article to which it is applied.

[0228] Hereinafter, the present invention will be described in more detail based on the following examples and comparative examples. However, the examples and comparative examples are provided only as examples for more specifically explaining the present invention, and the present invention is not limited to the following examples and comparative examples.

[0229] Preparation Example - Preparation of Pretreated Nanocellulose

[0230] Cellulose nanocrystals (NVC-100, manufacturer: Celluforce) in the form of a dry powder with a particle size of about 1 μm to about 50 μm were dispersed in water at 1% by weight, and then ultrasonic treatment was performed for 2 minutes at an output of 20,000 J / s using a tip-type ultrasonic disperser to produce pretreated nanocellulose.

[0231] Example - Preparation of Biodegradable Resin Composition

[0232] Example 1

[0233] - First step: Obtain a prepolymer

[0234] 1,4-Butanediol (1,4-BDO), terephthalic acid (TPA), and a titanium-based catalyst tetrabutyl titanate (Dupont, manufactured by Tyzor TnBT) were added to a 5-kg esterification reactor equipped with a nitrogen inlet and a stirrer to prepare a slurry. Here, the molar ratio of 1,4-butanediol to terephthalic acid was 100:47. Then, the slurry was heated until 210 °C, and the esterification reaction was carried out until about 90% or more of the by-product water was discharged, thereby producing a first prepolymer.

[0235] Adipic acid (AA) was added to the first prepolymer. Here, the molar ratio of 1,4-butanediol to adipic acid was 100:53, and the molar ratio of terephthalic acid to adipic acid was 47:53.

[0236] Next, the pretreated nanocellulose according to the preparation example, triethyl phosphonoacetate (TEPA) as a heat stabilizer, glycerol (Gly) as a branching agent, and titanium dioxide (TiO2) as an inorganic nucleating agent were added to the first prepolymer, and then the esterification reaction was carried out until about 90% or more of the by-product water was discharged. Then, tetrabutyl titanate (Dupont, manufactured by Tyzor TnBT) as a titanium-based catalyst was added thereto, and then stirred for 10 minutes, thereby producing a second prepolymer.

[0237] - Second step: Polycondensation reaction

[0238] The second prepolymer produced in the reactor was transferred to a 5-kg size polycondensation reactor. Then, the temperature was slowly heated to 240 °C under a vacuum condition of about 1 torr or lower, and then the polycondensation reaction was carried out for about 200 minutes to obtain a biodegradable resin composition.

[0239] Examples 2 to 5 and Comparative Examples 1 to 4

[0240] A biodegradable resin composition was prepared in the same manner as in Example 1, except that the components and contents shown in Table 1 were used.

[0241] [Table 1]

[0242]

[0243] Experimental Example

[0244] Experimental Example 1 - Crystallinity

[0245] For each of the biodegradable resin compositions of Examples 1 to 5 and Comparative Examples 1 to 4, the crystallinity was calculated according to the following calculation formula using the crystal melting energy value and crystal formation energy value measured by a differential scanning calorimeter. The results are shown in Table 2 below.

[0246] [Calculation formula]

[0247] Degree of crystallinity (%) = [(Energy required to melt 1 g of the biodegradable resin composition (crystal melting energy (J / g) - crystal formation energy (J / g)) / Energy required to melt 1 g of the biodegradable resin composition with 100% crystallinity (J / g))] × 100

[0248] Experimental Example 2 - Melt flow rate

[0249] According to ASTM D1238, the biodegradable resin compositions of Examples 1 to 5 and Comparative Examples 1 to 4 were pressed using a 2.16 kg weight at each of 190 °C and 230 °C, and then the discharge amount for 10 minutes was measured. The results are shown in Table 2 below.

[0250] Experimental Example 3 - Isothermal crystallization time

[0251] The biodegradable resin compositions of Examples 1 to 5 and Comparative Examples 1 to 4 were heated at a heating rate of 10 °C / min until 220 °C, and then held for 5 minutes. Subsequently, the temperature was lowered at a cooling rate of 100 °C / min until 70 °C, and then held in an isothermal state for 100 minutes.

[0252] Next, the time when the total area of the crystallization peak measured by differential scanning calorimetry was halved was measured. The results are shown in Table 2 below.

[0253] Experimental Example 4 - Evaluation of spinning ability

[0254] Using a single-fiber spinning device, under the conditions of a spinning speed of 1,500 m / min, a melting temperature of 230 °C, a nozzle temperature of 250 °C, and a quenching air temperature of 20 °C, the spinning ability of the biodegradable resin compositions of Examples 1 to 5 and Comparative Examples 1 to 4 was evaluated according to the following criteria. The results are shown in Table 2 below.

[0255] - Excellent: During the spinning of single fibers, the nozzle discharge is smooth, no fiber-to-fiber fusion occurs after quenching, and the deviation between fiber deniers is 20% or less.

[0256] - Qualified: During the spinning of single fibers, the nozzle discharge is smooth, no fiber-to-fiber fusion occurs after quenching, and the deviation between fiber deniers is greater than 20% and 40% or less.

[0257] - Poor: During the spinning of single fibers, the nozzle cannot discharge, or fiber-to-fiber fusion occurs after quenching.

[0258] Experimental Example 5 - Bonding strength

[0259] The biodegradable resin compositions of each of Examples 1 to 5 and Comparative Examples 1 to 4 were pressed at 210 °C under a pressure of 10 MPa for 3 minutes to produce sheets having a width of 20 mm, a length of 100 mm, and a thickness of 0.3 mm. Two of the sheets having a length of 75 mm were placed horizontally face to face, and then bonded at 90 °C under a pressure of 5 MPa for 10 minutes.

[0260] Next, in order to measure the bond strength of the two bonded sheets, a 180° lap shear test was carried out at a tensile speed of 100 mm / min. The results are shown in Table 2 below.

[0261] Experimental Example 6 - Biodegradability

[0262] For the biodegradable resin compositions of each of Examples 1 to 5 and Comparative Examples 1 to 4, the aerobic biodegradability was measured for 6 months under composting conditions according to ISO 14855. The results are shown in Table 2 below.

[0263] [Table 2]

[0264]

[0265]

[0266] As shown in Tables 1 and 2, it was confirmed that the biodegradable resin compositions of Examples 1 to 5 exhibited biodegradability equal to or superior to that of the biodegradable resin compositions of Comparative Examples 1 to 4.

[0267] Furthermore, it was confirmed that the biodegradable resin compositions of Examples 1 to 5 exhibited melt flow rates, isothermal crystallization times, and bond strengths suitable for making nonwoven fabrics by a spinning process, but did not exhibit fiber-to-fiber fusion or fiber breakage after spinning, thereby enabling the control of the denier of the fibers.

[0268] Explanation of Reference Numerals

[0269] 100: Slurry stirrer

[0270] 200: Esterification reaction section

[0271] 300: Polycondensation reaction section

[0272] 400: Post-treatment section

[0273] 510: First recovery section

[0274] 520: Second recovery section.

Claims

1. A biodegradable resin composition comprising: A biodegradable resin comprising a first repeating unit derived from a diol having 2 to 4 carbon atoms and a second repeating unit derived from an aliphatic dicarboxylic acid having 2 to 6 carbon atoms; as well as Inorganic nucleating agents, The biodegradable resin composition has a crystallinity of 15% to 50% as measured using differential scanning calorimetry.

2. The biodegradable resin composition according to claim 1, wherein The molar ratio of the first repeating unit: the second repeating unit is 4:1 to 1:

1.

3. The biodegradable resin composition according to claim 1, wherein The biodegradable resin further includes a third repeating unit derived from an aromatic dicarboxylic acid.

4. The biodegradable resin composition according to claim 3, wherein The molar ratio of the first repeating unit: the third repeating unit is 10:3 to 10:

7.

5. The biodegradable resin composition according to claim 3, wherein: The molar ratio of the second repeating unit:the third repeating unit is 3:2 to 2:

3.

6. The biodegradable resin composition according to claim 1, wherein The biodegradable resin composition includes the inorganic nucleating agent in an amount of about 10 ppm to about 10,000 ppm based on the total weight of the biodegradable resin composition.

7. The biodegradable resin composition according to claim 1, wherein The biodegradable resin composition includes nanocellulose having an average length of 10 nm to 300 nm.

8. The biodegradable resin composition according to claim 1, wherein The biodegradable resin composition includes a branching agent including at least one of a trivalent or higher-valent alcohol and a trivalent or higher-valent carboxylic acid.

9. The biodegradable resin composition according to claim 8, wherein The biodegradable resin composition includes the branching agent in an amount of about 500 ppm to about 3,000 ppm based on the total weight of the biodegradable resin composition.

10. A biodegradable nonwoven fabric, comprising a biodegradable resin composition, wherein the biodegradable resin composition comprises: A biodegradable resin comprising a first repeating unit derived from a diol having 2 to 4 carbon atoms and a second repeating unit derived from an aliphatic dicarboxylic acid having 2 to 6 carbon atoms; as well as Inorganic nucleating agents, The biodegradable resin composition has a crystallinity of 15% to 50% as measured using differential scanning calorimetry.

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