Biodegradable absorbent

Abstract

The present invention provides a biodegradable absorber comprising: a plurality of melt-blown layers; and an absorption layer disposed between the melt-blown layers, wherein the melt-blown layers comprise a first biodegradable resin composition, and the first biodegradable resin composition comprises a first biodegradable polyester resin containing a diol-derived unit, an aromatic dicarboxylic acid-derived unit, and an aliphatic dicarboxylic acid-derived unit.

Description

biodegradable absorbent

[0001] The present invention relates to a biodegradable absorbent.

[0002] Nonwoven webs manufactured using the Coform process are composite structures of meltblown fibers and absorbent materials. These nonwoven webs are used in a wide range of applications, including disposable tissues, sanitary absorbents, and medical blood pads.

[0003] Typically, meltblown fibers are formed from thermoplastic resins including polypropylene or propylene and olefin copolymers.

[0004] In the case of the above resin, due to the high crystallinity of about 60%, after melt-blown spinning, each filament of the fiber exhibited stiff characteristics, resulting in a problem of reduced touch sensation when in contact with the body.

[0005] In addition, due to the low tensile elongation characteristics, the resistance recovery characteristics due to external force were reduced, so the nonwoven web was easily broken, and there was a problem of the absorbent material placed between the meltblown layers being released to the outside.

[0006] In addition, the meltblown fibers above had the problem of causing environmental pollution after disposal due to their poor biodegradability.

[0007]

[0008] The present invention provides a biodegradable absorbent having excellent biodegradability and mechanical properties and improved touch.

[0009]

[0010] A biodegradable absorbent according to the present invention comprises a plurality of melt-blown layers and an absorbent layer disposed between the melt-blown layers, wherein the melt-blown layers comprise a first biodegradable resin composition, and the first biodegradable resin composition comprises a first biodegradable polyester resin comprising a diol-derived unit, an aromatic dicarboxylic acid-derived unit, and an aliphatic dicarboxylic acid-derived unit.

[0011] In one embodiment of the present invention, the first biodegradable resin composition may further include a nucleating agent.

[0012] In one embodiment of the present invention, the melt-blown layer further comprises a second biodegradable resin composition, wherein the second biodegradable resin composition comprises a second biodegradable polyester resin, and the second biodegradable polyester resin is selected from the group consisting of poly-3-hydroxybutyrate, poly-3-hydroxyvalerate, poly-3-hydroxyhexanoate, poly-3-hydroxyoctanoate, poly(3-hydroxybutyrate-co-3-hydroxyvalerate), poly(3-hydroxybutyrate-co-3-hydroxyhexanoate), poly(3-hydroxybutyrate-co-4-hydroxybutyrate), poly(3-hydroxybutyrate-co-3-valerate), poly(3-hydroxybutyrate-co-3-hydroxyundec-10-enoate), poly-3-hydroxyalkanoate). It may include at least one selected from the group consisting of polylactic acid, polybutylene succinate, polybutylene adipate, polybutylene succinate-adipate, polybutylene succinate-terephthalate, and polybutylene succinate adipate terephthalate.

[0013] In one embodiment of the present invention, the absorbent layer may include pulp fibers derived from non-wood biomass raw materials.

[0014] In one embodiment of the present invention, the pulp fiber may have a lignin content of 30 wt% or less.

[0015] In one embodiment of the present invention, the biodegradable absorbent may comprise 15 wt% to 99 wt% of the melt-blown layer and 1 wt% to 85 wt% of the absorbent layer.

[0016] In one embodiment of the present invention, the first biodegradable resin composition may have a melt index of 25 g / 10 min to 60 g / 10 min at 190°C.

[0017] In one embodiment of the present invention, the biodegradable absorbent may have a tensile elongation in the MD direction of 20% to 80% and a tensile elongation in the CD direction of 30% to 120% according to KSK ISO 9073-18.

[0018] In one embodiment of the present invention, the biodegradable absorbent may have a tensile strength in the MD direction of 0.50 kgf / 2.5 cm to 0.90 kgf / 2.5 cm and a tensile strength in the CD direction of 0.20 kgf / 2.5 cm to 0.60 kgf / 2.5 cm according to KSK ISO 9073-18.

[0019] In one embodiment of the present invention, the biodegradable absorbent may have a static friction coefficient of the melt-blown layer surface of 0.05 to 0.5 according to ASTM D 1894.

[0020] A biodegradable melt-blown resin composition according to the present invention comprises a first biodegradable polyester resin comprising a diol-derived unit, an aromatic dicarboxylic acid-derived unit, and an aliphatic dicarboxylic acid-derived unit.

[0021] In one embodiment of the present invention, the biodegradable melt-blown resin composition may further include a melt strength enhancer.

[0022] In one embodiment of the present invention, the biodegradable melt-blown resin composition may further include a nucleating agent.

[0023] In one embodiment of the present invention, the biodegradable melt-blown resin composition may further include a second biodegradable polyester resin, wherein the second biodegradable polyester resin is selected from the group consisting of poly-3-hydroxybutyrate, poly-3-hydroxyvalerate, poly-3-hydroxyhexanoate, poly-3-hydroxyoctanoate, poly(3-hydroxybutyrate-co-3-hydroxyvalerate), poly(3-hydroxybutyrate-co-3-hydroxyhexanoate), poly(3-hydroxybutyrate-co-4-hydroxybutyrate), poly(3-hydroxybutyrate-co-3-valerate), poly(3-hydroxybutyrate-co-3-hydroxyundec-10-enoate), poly-3-hydroxyalkanoate), polylactic acid, polybutylenesuccinate, It may include at least one selected from the group consisting of polybutylene adipate, polybutylene succinate-adipate, polybutylene succinate-terephthalate, and polybutylene succinate adipate terephthalate.

[0024]

[0025] The biodegradable absorbent according to the present invention has the effect of not causing environmental problems as biodegradation occurs after disposal by selecting a biodegradable polyester resin in the melt-blown layer.

[0026] In addition, the biodegradable absorbent includes pulp fibers derived from non-wood biomass raw materials in the absorbent layer, thereby having a CO2 emission reduction effect without deterioration of mechanical properties compared to wood biomass raw materials.

[0027] In addition, the biodegradable polyester resin is selected to include a diol-derived unit, an aromatic dicarboxylic acid-derived unit, and an aliphatic dicarboxylic acid-derived unit, so that it has excellent tensile elongation and elasticity properties, and thus the resistance recovery properties due to external force are improved, so that the absorbent material formed between the melt-blown layers does not cause a problem of flying outward.

[0028] In addition, by selecting a melt strength enhancer and improving the surface properties of the melt blown layer, the melt blown filament can exhibit soft properties and has the effect of improving the touch sensation when in contact with the body.

[0029]

[0030] Figure 1 is a schematic drawing showing a cross-section of a biodegradable absorbent according to an embodiment.

[0031] FIG. 2 is a schematic drawing of a filament including a core portion and a sheath portion according to an embodiment.

[0032] FIG. 3 is a schematic drawing showing a cross-section of a filament including a core portion and a sheath portion according to an embodiment.

[0033] Figure 4 is a schematic drawing of an apparatus for manufacturing a first biodegradable resin composition.

[0034]

[0035] 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 idea of ​​the present invention, and 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 application, and the technical idea of ​​the present invention is not construed as being limited to the embodiments described in this specification or application.

[0036] Additionally, when a component is referred to as "including" in this specification or application, unless otherwise specifically stated, this does not exclude other components, but rather implies the inclusion of additional components. Furthermore, all numerical ranges indicating physical property values, dimensions, etc. of the components described in this specification or application should be understood to be modified by the term "about" in all cases, unless otherwise specified.

[0037] Additionally, 'ppm' in this specification or application means weight basis.

[0038] Additionally, the term 'derived from' in this specification or application means a component, structure, or substance itself derived from a substance.

[0039]

[0040] Fig. 1 is a schematic drawing illustrating a cross-section of a biodegradable absorbent according to an embodiment. Referring to Fig. 1, a biodegradable absorbent (1) according to the present invention includes a plurality of melt-blown layers (10) and an absorbent layer (20) disposed between the melt-blown layers (10).

[0041] The above melt-blown layer (10) includes a first biodegradable resin composition, and the first biodegradable resin composition includes a first biodegradable polyester resin including a diol-derived unit, an aromatic dicarboxylic acid-derived unit, and an aliphatic dicarboxylic acid-derived unit.

[0042] The above diol may be an aliphatic diol. The above diol may be a biomass-derived diol. The biomass may refer to biological organisms such as plants, microorganisms, fungi, and animals that receive solar energy. For example, the biomass may include plant-derived environmentally circulating resources such as starch-based resources such as grains and potatoes, cellulosic resources such as herbs, timber, rice straw, and rice husks, carbohydrate-based resources such as sugarcane and sugar beets, animal-derived environmentally circulating resources such as livestock manure, carcasses, and microbial cells, as well as various organic wastes such as paper and food waste derived from these resources. The biomass-derived diol may refer to a diol or diacid obtained by physically, chemically, and / or biologically treating the raw material of the biomass.

[0043] 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.

[0044] The above diol may be selected from the group consisting of 1,4-butanediol, 1,2-ethanediol, 1,3-propanediol, diethylene glycol, neopentyl glycol or derivatives thereof.

[0045] The above diol may be selected from the group consisting of 1,4-butanediol, 1,2-ethanediol, 1,3-propanediol or derivatives thereof.

[0046] The above diol may include 1,4-butanediol or a derivative thereof.

[0047] The above 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'-diphenyldicarboxylic acid, 4,4'-diphenyletherdicarboxylic acid, anthracenedicarboxylic acid, phenanthrenedicarboxylic acid or derivatives thereof.

[0048] The above aromatic dicarboxylic acid may be selected from the group consisting of terephthalic acid, dimethyl terephthalate, 2,6-naphthalene dicarboxylic acid, isophthalic acid or derivatives thereof.

[0049] The above aromatic dicarboxylic acid may include terephthalic acid, dimethyl terephthalate or derivatives thereof.

[0050] The above aliphatic dicarboxylic acid may be selected from the group consisting of oxalic acid, malonic acid, succinic acid, maleic acid, fumaric acid, glutaric acid, adipic acid, pimelic acid, terbric acid, azelaic acid, sebacic acid, dodecanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid or derivatives thereof.

[0051] The above aliphatic dicarboxylic acid may be selected from the group consisting of adipic acid, succinic acid, sebacic acid or derivatives thereof.

[0052] The above aliphatic dicarboxylic acid may include adipic acid or a derivative thereof.

[0053] The first biodegradable polyester resin may include a first block and a second block. The first biodegradable polyester resin may have a molecular structure in which the first block and the second block are alternately bonded.

[0054] The first block may include the diol residue and the aromatic dicarboxylic acid residue. 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 residue and the aromatic dicarboxylic acid residue. 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 repeating units of the diol and the aromatic dicarboxylic acid before the aliphatic dicarboxylic acid is bonded.

[0055] The second block may include the diol residue and the aliphatic dicarboxylic acid residue. 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 residue and the aliphatic dicarboxylic acid residue. 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 repeating units of the diol and the aliphatic dicarboxylic acid before the aromatic dicarboxylic acid is bonded.

[0056] In the first biodegradable polyester resin, the ratio (X / Y) of the number (X) of the first block and the number (Y) of the second block may be from about 0.5 to about 1.5. In the first biodegradable polyester resin, the ratio (X / Y) of the number (X) of the first block and the number (Y) of the second block may be from about 0.6 to about 1.4. In the first biodegradable polyester resin, the ratio (X / Y) of the number (X) of the first block and the number (Y) of the second block may be from about 0.7 to about 1.3. In the first biodegradable polyester resin, the ratio (X / Y) of the number (X) of the first block and the number (Y) of the second block may be from about 0.75 to about 1.2. Additionally, in the first biodegradable polyester resin, the ratio (X / Y) of the number (X) of the first blocks and the number (Y) of the second blocks may be 0.8 to 1.1. The number of the first blocks may be smaller than the number of the second blocks.

[0057] The number of the first blocks may be about 30 to about 300. The number of the first blocks may be about 40 to about 250. The number of the first blocks may be about 50 to about 220. The number of the first blocks may be about 60 to about 200. The number of the first blocks may be about 70 to about 200. The number of the first blocks may be about 75 to about 200.

[0058] The number of the first blocks may vary depending on the content of the aromatic dicarboxylic acid, the molecular weight of the first biodegradable polyester resin, and the polymerization process described below. As the molar ratio of the aromatic dicarboxylic acid increases and the molecular weight of the first biodegradable polyester resin increases, the number of the first blocks may increase.

[0059] The number of the second blocks may be about 30 to about 300. The number of the second blocks may be about 40 to about 250. The number of the second blocks may be about 50 to about 220. The number of the second blocks may be about 60 to about 200. The number of the second blocks may be about 70 to about 200. The number of the second blocks may be about 75 to about 200.

[0060] The number of the second blocks may vary depending on the content of the aliphatic dicarboxylic acid, the molecular weight of the first biodegradable polyester resin, and the polymerization process described below. As the molar ratio of the aliphatic dicarboxylic acid increases and the molecular weight of the first biodegradable polyester resin increases, the number of the second blocks may increase.

[0061] When the first biodegradable polyester resin includes the first block and the second block in the above range, the tensile elongation and elasticity properties of the biodegradable absorbent are improved, and it can have an appropriate biodegradability.

[0062] The above first block can be represented by the following chemical formula 1.

[0063] [Chemical Formula 1]

[0064]

[0065] Here, R1 is a substituted or unsubstituted arylene group having 6 to 20 carbon atoms, R2 is a substituted or unsubstituted alkylene group having 1 to 20 carbon atoms, and m may be 1 to 20.

[0066] The above R1 may be a substituted or unsubstituted phenylene group, and the above R2 may be a butylene group.

[0067] The above second block can be represented by the following chemical formula 2.

[0068] [Chemical Formula 2]

[0069]

[0070] Here, R3 and R4 are each independently a substituted or unsubstituted alkylene group having 1 to 20 carbon atoms, and n may be 1 to 20.

[0071] The above R3 and the above R4 may be a butylene group.

[0072] The first biodegradable polyester resin may have a structure in which the first block and the second block are alternately bonded to each other. The first biodegradable polyester resin may be represented by the following chemical formula 3.

[0073] [Chemical Formula 3]

[0074]

[0075] Here, R1 is a substituted or unsubstituted arylene group having 6 to 20 carbon atoms, R2 is a substituted or unsubstituted alkylene group having 1 to 20 carbon atoms, and m may be 1 to 20. In addition, R3 and R4 are each independently a substituted or unsubstituted alkylene group having 1 to 20 carbon atoms, and n may be 1 to 20.

[0076] The above diol residue may include a residue of 1,4-butanediol or a derivative thereof, the above aromatic dicarboxylic acid residue may include a residue of terephthalic acid or a derivative thereof, and the above aliphatic dicarboxylic acid residue may include a residue of adipic acid or a derivative thereof.

[0077] The first biodegradable polyester resin may include a first block comprising a residue of 1,4-butanediol or a derivative thereof and a residue of terephthalic acid or a derivative thereof.

[0078] The first biodegradable polyester resin may include a first block comprising a residue of 1,4-butanediol or a derivative thereof and a residue of dimethyl terephthalate or a derivative thereof.

[0079] The first biodegradable polyester resin may include a second block comprising a residue of 1,4-butanediol or a derivative thereof and a residue of adipic acid or a derivative thereof.

[0080] Alternatively, the first biodegradable polyester resin may comprise a second block comprising a residue of 1,4-butanediol or a derivative thereof and a residue of succinic acid or a derivative thereof.

[0081] The first biodegradable polyester resin may include a first block comprising a residue of 1,4-butanediol or a derivative thereof and a residue of terephthalic acid or a derivative thereof; and a second block comprising a residue of 1,4-butanediol or a derivative thereof and a residue of adipic acid or a derivative thereof.

[0082] The first block may be represented by the following chemical formula 4, and the second block may be represented by the following chemical formula 5.

[0083] [Chemical Formula 4]

[0084]

[0085] Here, m can be 1 to 20.

[0086] [Chemical Formula 5]

[0087]

[0088] Here, n can be 1 to 20.

[0089] The above first biodegradable polyester resin can be represented by the following chemical formula 6.

[0090] [Chemical Formula 6]

[0091]

[0092] Here, m may be 1 to 20, and n may be 1 to 20.

[0093] When the first block and the second block satisfy the above configuration, it may be more advantageous to provide a biodegradable absorbent having excellent biodegradability and improved mechanical properties.

[0094] The first biodegradable polyester resin may further comprise a branching agent. The branching agent may comprise a trihydric or higher alcohol and / or a trihydric or higher carboxylic acid. The branching agent may react with the diol, the aromatic dicarboxylic acid, and the aliphatic dicarboxylic acid. Accordingly, the branching agent may be included as part of the molecular structure of the first biodegradable polyester resin.

[0095] The above three or more alcohols may be selected from the group consisting of glycerol, pentaerythritol, and trimethylolpropane.

[0096] The above three or more carboxylic acids are methane tricarboxylic 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, At least one may be selected from the group consisting of cyclopentane-1,2,3,4-tetracarboxylic acid or benzene-1,2,4,5-tetracarboxylic acid.

[0097] The content of the branching agent may be 0.1 wt% to 5 wt%, 0.1 wt% to 3 wt%, or 0.1 wt% to 1 wt% based on the total weight of the first biodegradable polyester resin.

[0098] When the above range is satisfied, the biodegradable absorbent can have appropriate mechanical properties and biodegradability.

[0099] The first biodegradable resin composition may further include a nucleating agent. The nucleating agent may be a substance that forms a nucleus for the formation of crystal nuclei. When the nucleating agent is included in the first biodegradable resin composition, the crystallization rate may be improved. In addition, the nucleating agent may control the crystallization temperature of the first biodegradable resin composition.

[0100] The nucleating agent may be a reinforcing agent that improves the mechanical properties of a biodegradable absorbent comprising the first biodegradable resin composition. The nucleating agent may control the deformation characteristics of the first biodegradable resin composition due to ultraviolet rays. The nucleating agent may control the hydrolysis characteristics of the first biodegradable resin composition. The nucleating agent may control the biodegradability of a biodegradable absorbent comprising the first biodegradable resin composition.

[0101] The nucleating agent may include an inorganic material. The inorganic material may include at least one of mica, talc, silica, titanium dioxide (TiO2), and calcium carbonate (CaCO3).

[0102] The nucleating agent may be a fiber derived from biomass. The nucleating agent may be a fiber composed of organic matter. The nucleating agent may be a fibrous nucleating agent. The fibrous nucleating agent may be nanocellulose.

[0103] The above nanocellulose may be at least one selected from the group consisting of nanocrystalline cellulose, cellulose nanofibers, microfibrillated cellulose, hydroxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, hydroxypropylmethyl cellulose, cellulose acetate, methyl cellulose, ethyl cellulose, propyl cellulose, butyl cellulose, pentyl cellulose, hexyl cellulose, and cyclohexyl cellulose.

[0104] The nanocellulose may contain an ionically bonded metal. The nanocrystalline cellulose may contain an alkali metal. The nanocellulose may contain elemental sodium. In addition, the nanocellulose may contain a sulfate. The nanocellulose may contain a carboxylic acid salt. The nanocellulose may be cellulose hydrogen sulfate sodium salt.

[0105] The above nanocellulose can be represented by the following chemical formula 7.

[0106] [Chemical Formula 7]

[0107]

[0108] 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.

[0109] The sulfur content of the nanocellulose may be about 0.1 wt% to about 1.2 wt%, about 0.5 wt% to about 1.2 wt%, or about 0.75 wt% to about 1.1 wt% based on the entire nanocellulose. The sulfur content of the nanocellulose may be measured by ASTM D2622.

[0110] The above nanocellulose may include a surface treatment agent. The surface treatment agent may include at least one selected from the group consisting of sulfates and carboxylates. That is, the nanocellulose may be surface treated with the sulfates or carboxylates.

[0111] The zeta potential of the 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 cellulose may be measured by a zeta potential meter (e.g., Zetasizer Nano ZS, Malvern).

[0112] The content of the nanocellulose may be about 0.01 parts by weight to about 2 parts by weight, about 0.03 parts by weight to about 1.5 parts by weight, about 0.04 parts by weight to about 1.2 parts by weight, or about 0.05 parts by weight to about 1 part by weight, based on 100 parts by weight of the first biodegradable polyester resin.

[0113] Since the above nanocellulose has the above-described characteristics, it can be uniformly dispersed in the first biodegradable resin composition and improve the mechanical properties of the first biodegradable resin composition.

[0114] The above nanocellulose can perform a crystal nucleating function, thereby improving the crystallization rate of the first biodegradable resin composition. As a result, the nanocellulose can increase the crystallization temperature of the first biodegradable resin composition.

[0115] Since the above nanocellulose has the above characteristics, the first biodegradable resin composition can have appropriate UV resistance properties, biodegradation rate, and hydrolysis rate.

[0116] The above first biodegradable resin composition may further include a metal salt.

[0117] The content of the metal salt may be about 0.1 ppm to about 1,000 ppm, about 1 ppm to about 500 ppm, about 1 ppm to about 100 ppm, or about 1 ppm to about 50 ppm based on the total weight of the first biodegradable resin composition.

[0118] The metal salt may be selected from the group consisting of nitrates, sulfates, hydrochlorides, and carboxylates. The metal salt may be selected from the group consisting of titanium salts, silicon salts, sodium salts, calcium salts, potassium salts, magnesium salts, copper salts, iron salts, aluminum salts, and silver salts. The metal salt may be selected from the group consisting of magnesium acetate, calcium acetate, potassium acetate, copper nitrate, silver nitrate, and sodium nitrate.

[0119] The above metal salt may include at least one selected from the group consisting of iron (Fe), magnesium (Mg), nickel (Ni), cobalt (Co), copper (Cu), palladium (Pd), zinc (Zn), vanadium (V), titanium (Ti), indium (In), manganese (Mn), silicon (Si), and tin (Sn).

[0120] The metal salt may be selected from the group consisting of acetate, nitrate, nitride, sulfide, sulfate, sulfoxide, hydroxide, hydrate, chloride, chlorinate, and bromide.

[0121] Since the first biodegradable resin composition contains the metal salt in the above content, the biodegradation rate can be appropriately controlled.

[0122] The above first biodegradable resin composition may further include a hydrolysis agent.

[0123] The above hydrolysis agent may be selected from at least one silicon-based compound such as silane, silazane or siloxane.

[0124] The above hydrolysis agent may include an alkoxy silane. The hydrolysis agent may include trimethoxy silane and / or triethoxy silane. The hydrolysis agent may include an alkoxy silane containing an epoxy group.

[0125] The above hydrolysis agent may include at least one selected from the group consisting of 2-(3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-glycidoxypropyl methyldimethoxysilane, 3-glycidoxypropyl trimethoxysilane, 3-glycidoxypropyl methyldiethoxysilane, and 3-glycidoxypropyl triethoxysilane.

[0126] The content of the above hydrolysis agent in the first biodegradable resin composition may be about 1 ppm to about 10,000 ppm, about 1 ppm to about 1,000 ppm, about 5 ppm to about 500 ppm, or about 1 ppm to 300 ppm.

[0127] The above hydrolysis-resistant agent can be bonded to the first biodegradable polyester resin. The hydrolysis-resistant agent can be chemically bonded to the first biodegradable polyester resin. The hydrolysis-resistant agent can be chemically bonded to a polymer included in the first biodegradable polyester resin. The hydrolysis-resistant agent can couple the polymers included in the first biodegradable polyester resin to each other.

[0128] Since the first biodegradable resin composition includes the hydrolysis-resistant agent in the above range, it can have appropriate hydrolysis-resistant properties.

[0129] The first biodegradable resin composition may further include a melt strength enhancer. The melt strength enhancer may reduce heat generation due to friction during mixing, melting, and processing of raw materials, and may have an excellent dispersing effect on the first biodegradable polyester resin. As a result, the surface properties of the melt-blown layer comprising the first biodegradable resin composition are improved, thereby enabling the melt-blown filament to exhibit soft characteristics and improve the touch sensation when in contact with the body.

[0130] The above melt strength enhancer may include one or more amide compounds.

[0131] The above amide compound may include a first amide compound having 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 first amide compound may have a melting point (Tm) of 140°C to 147°C, 141°C to 147°C, 142°C to 147°C, or 145°C to 147°C. The first amide compound may have a crystallization temperature (Tc) of 100°C to 150°C, 110°C to 150°C, 130°C to 150°C, or 140°C to 150°C. The first amide-based compound may have a thermal decomposition temperature of 200°C or higher, 260°C or higher, 300°C or higher, 400°C or higher, or 260°C to 450°C. The first amide-based compound may be a compound having two or more amide groups per molecule. The first amide-based compound may not include an amide group at a molecular terminal. The first amide-based compound may be a compound having a symmetrical molecule structure.

[0132] The first amide compound as described above exhibits a polarity that readily reacts with the first biodegradable polyester resin, and excessive polarization is suppressed, so that dispersibility for the first biodegradable polyester resin can be further improved.

[0133] The above amide compound may include a second amide compound having a weight average molecular weight of 300 g / mol to 1,000 g / mol, 300 g / mol to 800 g / mol, 300 g / mol to 500 g / mol, or 300 g / mol to 400 g / mol. The second amide compound may have a melting point (Tm) of 75°C to 85°C, 77°C to 85°C, 79°C to 85°C, or 80°C to 85°C. The second amide compound may have a crystallization temperature (Tc) of 50°C to 100°C, 60°C to 100°C, 70°C to 100°C, or 70°C to 90°C. The second amide-based compound may have a thermal decomposition temperature of 200° C. or higher, 280° C. or higher, 290° C. or higher, 300° C. or higher, or 280° C. to 350° C. The second amide-based compound may be a compound containing an alkene. The second amide-based compound may be a compound containing an amide group at a molecular terminal group. The second amide-based compound may be a compound containing an amide group at one of the molecular terminal groups. The second amide-based compound may be a compound in a cis form.

[0134] The second amide compound as described above can improve the slip properties between the first biodegradable polyester resin, can impart an anti-blocking function, and can further improve high-temperature stability.

[0135] The above amide-based compound may include the first amide-based compound and the second amide-based compound to improve the dispersibility of the first biodegradable polyester resin and the surface properties of the melt-blown layer.

[0136] The above amide compound may be at least one selected from the group consisting of N,N`-ethylenebis-12-hydroxystearamide, stearyl erucamide, stearyl stearamide, ethylene bis(stearamide), calcium stearate, stearamide, and erucamide.

[0137] The content of the above melt strength enhancer may be 0.1 phr (per hundred resin) to 4 phr, 0.1 phr to 4 phr, 0.1 phr to 4 phr, or 0.1 phr to 4 phr relative to the first biodegradable polyester resin. When the above range is satisfied, soft characteristics can be exhibited without deterioration of mechanical properties.

[0138] The first biodegradable resin composition may include a heat stabilizer. The heat stabilizer may be at least one selected from the group consisting of amine-based high-temperature heat stabilizers such as tetraethylenepentaamine, triethylphosphonoacetate, phosphoric acid, phosphorous acid, polyphosphric acid, trimethyl phosphate (TMP), triethyl phosphate, trimethyl phosphine, and triphenyl phosphine.

[0139] The above heat stabilizer may include triethylphosphonoacetate.

[0140] 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 based on the total weight of the first biodegradable resin composition. When the above range is satisfied, deterioration due to high temperature during the reaction process can be controlled, so that color can be improved.

[0141] The above first biodegradable resin composition may have an isothermal crystallization time at 90°C of 10 seconds to 900 seconds according to the following measurement method.

[0142] [measurement method]

[0143] 1) The first biodegradable resin composition is heated to 220°C at a heating rate of 10°C / min, and then maintained for 5 minutes.

[0144] 2) Afterwards, the first biodegradable resin composition is cooled to 90°C at a cooling rate of 100°C / min, and then maintained in an isothermal state for 100 minutes.

[0145] 3) Using differential scanning calorimetry, the time taken for the total area of ​​the crystallization peak of the first biodegradable resin composition to become half of the total area of ​​the crystallization peak of the first biodegradable resin composition is measured.

[0146] The above isothermal crystallization time is to rapidly cool the first biodegradable resin composition in a molten state and evaluate the time until crystallization.

[0147] A short isothermal crystallization time indicates rapid crystallization. Rapid crystallization may imply that molecular motion is suppressed and crystals are formed in the early stages after cooling.

[0148] The above isothermal crystallization time can be controlled depending on whether the aforementioned nucleating agent is included and its content.

[0149] The fact that the first biodegradable resin composition has an isothermal crystallization time according to the above measurement method means a crystallization speed at which the first biodegradable resin composition can be manufactured into a nonwoven fabric by a melt-blown process, and can also have meaning as an indicator that the phenomenon of fiber-to-fiber fusion and fiber breakage during a spinning process can be suppressed.

[0150] In addition, the fact that the first biodegradable resin composition has an isothermal crystallization time according to the measurement method may have meaning as an indicator that the mechanical properties of the biodegradable absorbent including the first biodegradable resin composition can be improved.

[0151] The first biodegradable resin composition may have an isothermal crystallization time at 90°C of 40 to 800 seconds according to the measurement method. Preferably, the first biodegradable resin composition may have an isothermal crystallization time at 90°C of 41 to 795 seconds, 40 to 790 seconds, 40 to 785 seconds, or 41 to 784 seconds according to the measurement method. When the above range is satisfied, the mechanical properties of the biodegradable absorbent comprising the first biodegradable resin composition may be improved.

[0152] The first biodegradable resin composition may have a crystallization temperature (Tc) measured using the differential scanning calorimeter of 35°C to 90°C, 40°C to 90°C, 45°C to 90°C, 45°C to 85°C, or 50°C to 83°C.

[0153] The first biodegradable resin composition may have a melting temperature (Tm). The melting temperature may be measured by the differential scanning calorimeter. The first biodegradable resin composition may have a melting temperature of 100°C to 180°C, 100°C to 150°C, 110°C to 130°C, or 119°C to 124°C.

[0154] The first biodegradable resin composition may have a glass transition temperature (Tg). The glass transition temperature may be measured by the differential scanning calorimeter. The first biodegradable resin composition may have a glass transition temperature of -50°C to 0°C, -40°C to 0°C, -40°C to -20°C, or -33°C to -28°C.

[0155] The first biodegradable resin composition may have a melt index of 25 g / 10 min to 60 g / 10 min, 25 g / 10 min to 55 g / 10 min, 25 g / 10 min to 50 g / 10 min, or 30 g / 10 min to 50 g / 10 min at 190° C.

[0156] When the above range is satisfied, the efficiency of the melt blown process using the first biodegradable resin composition can be improved.

[0157] The first biodegradable resin composition may have a first irreversible strain of less than 30% as measured by the following measurement method.

[0158] [measurement method]

[0159] 1) The first biodegradable resin composition is compressed at a temperature of 200° C. and a pressure of 20 Mpa while being placed between a pair of flat stainless steel molds, thereby producing a first biodegradable resin composition sheet having a thickness of 300 μm.

[0160] 2) The first biodegradable resin composition sheet is cut to produce a sample including a test section having a width of 3.18 mm and a length of 25 mm.

[0161] 3) The test section is pulled at a speed of 10 mm / min in the longitudinal direction at room temperature. At this time, the pull is increased by 40% compared to the total length of the test section.

[0162] 4) The above test section is recovered at room temperature for 5 minutes in the absence of external force.

[0163] 5) The first irreversible strain is derived by the following equation.

[0164] [ceremony]

[0165] 1st irreversible strain = (length of test section after recovery - 25 mm) / 25 mm

[0166] The length of the test section in the above formula refers to the length of the test section recovered after being pulled by 40% of the total length of the test section.

[0167] The first biodegradable resin composition may have a second irreversible strain of less than 20% as measured by the following measurement method.

[0168] [measurement method]

[0169] 1) The first biodegradable resin composition is compressed at a temperature of 200° C. and a pressure of 20 Mpa while being placed between a pair of flat stainless steel molds, thereby producing a first biodegradable resin composition sheet having a thickness of 300 μm.

[0170] 2) The first biodegradable resin composition sheet is cut to produce a sample including a test section having a width of 3.18 mm and a length of 25 mm.

[0171] 3) The above test section is pulled at a speed of 10 mm / min in the longitudinal direction at room temperature. At this time, the pull is increased by 30% compared to the total length of the above test section.

[0172] 4) The above test section is recovered at room temperature for 5 minutes in the absence of external force.

[0173] 5) The second irreversible strain is derived by the following equation.

[0174] [ceremony]

[0175] Second irreversible strain = (length of test section after recovery - 25 mm) / 25 mm

[0176] The length of the test section in the above formula refers to the length of the test section recovered after being pulled by 30% of the total length of the test section.

[0177] The first biodegradable resin composition may have a third irreversible strain of less than 10% as measured by the following measurement method.

[0178] [measurement method]

[0179] 1) The first biodegradable resin composition is compressed at a temperature of 200° C. and a pressure of 20 Mpa while being placed between a pair of flat stainless steel molds, thereby producing a first biodegradable resin composition sheet having a thickness of 300 μm.

[0180] 2) The first biodegradable resin composition sheet is cut to produce a sample including a test section having a width of 3.18 mm and a length of 25 mm.

[0181] 3) The above test section is pulled at a speed of 10 mm / min in the longitudinal direction at room temperature. At this time, the pull is increased by 20% compared to the total length of the above test section.

[0182] 4) The above test section is recovered at room temperature for 5 minutes in the absence of external force.

[0183] 5) The third irreversible strain is derived by the following equation.

[0184] [ceremony]

[0185] Third irreversible strain = (length of test section after recovery - 25 mm) / 25 mm

[0186] The length of the test section in the above formula refers to the length of the test section recovered after being pulled by 20% of the total length of the test section.

[0187] The first biodegradable resin composition may have a fourth irreversible strain of less than 5% as measured by the following measurement method.

[0188] [measurement method]

[0189] 1) The first biodegradable resin composition is compressed at a temperature of 200° C. and a pressure of 20 Mpa while being placed between a pair of flat stainless steel molds, thereby producing a first biodegradable resin composition sheet having a thickness of 300 μm.

[0190] 2) The first biodegradable resin composition sheet is cut to produce a sample including a test section having a width of 3.18 mm and a length of 25 mm.

[0191] 3) The above test section is pulled at a speed of 10 mm / min in the longitudinal direction at room temperature. At this time, the pull is increased by 10% compared to the total length of the above test section.

[0192] 4) The above test section is recovered at room temperature for 5 minutes in the absence of external force.

[0193] 5) The fourth irreversible strain is derived by the following equation.

[0194] [ceremony]

[0195] 4th irreversible strain = (length of test section after recovery - 25 mm) / 25 mm

[0196] The length of the test section in the above formula refers to the length of the test section recovered after being pulled by 10% of the total length of the test section.

[0197] The above irreversible strain may be an indicator of the elastic recovery and stretchability of the biodegradable absorbent in the absence of an external force. In addition, having an irreversible strain value below a specific range may be an indicator that the first biodegradable resin composition is manufactured into ultrafine fibers having a diameter of less than 3 μm by a melt-blown process, so that the manufactured biodegradable absorbent may have a soft touch. It may be an indicator that the manufactured biodegradable absorbent exhibits a soft touch and at the same time, elasticity may be imparted in a temperature range of about 15°C to 40°C, where nonwoven fabrics are generally used.

[0198] The above first biodegradable resin composition has a temperature of maximum loss tangent as determined by dynamic mechanical analysis of -40°C to 0°C, a minimum temperature of a rubber flat region of less than 30°C, the rubber flat region is greater than the temperature of maximum loss tangent, and a temperature range in which the loss tangent change rate is less than 0.025 / 10°C.

[0199] Specifically, the maximum loss tangent temperature and the minimum temperature of the rubber flat region can be derived by dynamic mechanical analysis under the following conditions.

[0200] - Measuring instrument: Dynamic Mechanical Analyzer (DMA) TA 2980 / Q800

[0201] - Heating temperature: -40℃ to 80℃

[0202] - Heating rate: 10 ℃ / min

[0203] The above loss tangent (tanδ) can be calculated by the equation tanδ=(G") / (G') after the storage modulus (G') and loss modulus (G") at a frequency of 1 Hz are measured by the above dynamic mechanical analysis.

[0204] The temperature of the above maximum loss tangent may mean the peak temperature confirmed by the spectrum of the loss tangent for the temperature range of -40 °C to 80 °C of the above dynamic mechanical analysis.

[0205] The above rubber plateau region is defined by the plateau modulus, and may refer to a region in which the storage modulus and the loss modulus remain substantially constant after the storage modulus and the loss modulus rapidly decrease in the glass transition region, and specifically, may refer to a temperature range in which the loss tangent change rate is less than 0.025 / 10°C. The minimum temperature of the rubber plateau region may refer to a minimum temperature value among the temperature ranges of the rubber plateau region.

[0206] The values ​​of the temperature range of the maximum loss tangent and the minimum temperature range of the rubber flat region may be indicators that the biodegradable absorbent can have elastic recovery in the temperature range in which it can be used, and thus, even if the biodegradable absorbent is stretched by an external force, it will not break and can be given elasticity that can recover to its original length.

[0207] The first biodegradable resin composition may have a temperature of maximum loss tangent measured by the following measuring method of -40°C to 0°C, and a minimum temperature of a rubber flat region may be less than 30°C.

[0208] [measurement method]

[0209] 1) The first biodegradable resin composition is compressed at a temperature of 200° C. and a pressure of 20 Mpa while being placed between a pair of flat stainless steel molds, thereby producing a first biodegradable resin composition sheet having a thickness of 300 μm.

[0210] 2) The first biodegradable resin composition sheet is cut to produce a sample including a test section having a width of 5 mm and a length of 12 mm.

[0211] 3) The above test section is subjected to dynamic mechanical analysis, and the loss tangent is measured according to temperature as the temperature increases from -40°C to 80°C.

[0212] 4) The temperature having the maximum value among the above loss tangents is derived as the temperature of the maximum loss tangent.

[0213] 5) The temperature range in which the loss tangent change rate is less than 0.025 / 10 ℃ is derived as the rubber flat region.

[0214] The first biodegradable resin composition may have a maximum loss tangent temperature of -40°C to -5°C as measured by the above measurement method, and a minimum temperature of a rubber flat region may be less than 28°C. The first biodegradable resin composition may have a maximum loss tangent temperature of -40°C to -10°C as measured by the above measurement method, and a minimum temperature of a rubber flat region may be less than 26°C. The first biodegradable resin composition may have a maximum loss tangent temperature of -40°C to -15°C as measured by the above measurement method 5, and a minimum temperature of a rubber flat region may be 15°C or more to 25°C or less. When the above ranges are satisfied, a biodegradable absorbent manufactured from the first biodegradable resin composition may have excellent elasticity and a soft touch.

[0215] The melt-blown layer (10) further comprises a second biodegradable resin composition, wherein the second biodegradable resin composition comprises a second biodegradable polyester resin, and the second biodegradable polyester resin is selected from the group consisting of poly-3-hydroxybutyrate, poly-3-hydroxyvalerate, poly-3-hydroxyhexanoate, poly-3-hydroxyoctanoate, poly(3-hydroxybutyrate-co-3-hydroxyvalerate), poly(3-hydroxybutyrate-co-3-hydroxyhexanoate), poly(3-hydroxybutyrate-co-4-hydroxybutyrate), poly(3-hydroxybutyrate-co-3-valerate), poly(3-hydroxybutyrate-co-3-hydroxyundec-10-enoate), poly-3-hydroxyalkanoate). It may include at least one selected from the group consisting of polylactic acid, polybutylene succinate, polybutylene adipate, polybutylene succinate-adipate, polybutylene succinate-terephthalate, and polybutylene succinate adipate terephthalate.

[0216] Preferably, the second biodegradable polyester resin may include polylactic acid.

[0217] The above polylactic acid may be a high-melting-point polylactic acid having a stereocomplex crystal structure. In addition, the polylactic acid may be formed by solution mixing or melt mixing of poly L-lactic acid and poly D-lactic acid.

[0218] The above polylactic acid may include a unit represented by the following chemical formula 8.

[0219] [Chemical Formula 8]

[0220]

[0221] The polylactic acid may be a polymer comprising L-lactic acid units and / or D-lactic acid units. The polylactic acid may comprise poly L-lactic acid and / or poly D-lactic acid.

[0222] The poly L-lactic acid may be a polymer mainly comprising L-lactic acid units. The poly L-lactic acid may comprise 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 poly L-lactic acid may comprise D-lactic acid units and / or units other than lactic acid. The poly L-lactic acid may comprise 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%.

[0223] The poly D-lactic acid may be a polymer mainly comprising D-lactic acid units. The poly D-lactic acid may comprise 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 poly D-lactic acid may comprise the L-lactic acid units and / or units other than lactic acid. The poly D-lactic acid may comprise 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%.

[0224] Units other than the above lactic acid may be units derived from dicarboxylic acids, polyhydric alcohols, hydroxycarboxylic acids, lactones, etc. having functional groups capable of forming two or more ester bonds, and units derived from various polyesters, various polyethers, various polycarbonates, etc. composed of various components of these.

[0225] Examples of the above dicarboxylic acids include succinic acid, adipic acid, azelaic acid, sebacic acid, terephthalic acid, and isophthalic acid. 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 with ethylene oxide added thereto.

[0226] Examples of the above hydroxycarboxylic acids include glycolic acid, hydroxybutyric acid, etc. Examples of the lactones include glycolide, ε-caprolactone glycolide, ε-caprolactone, β-propiolactone, δ-butyrolactone, β- or γ-butyrolactone, pivalolactone, δ-valerolactone, etc.

[0227] The polylactic acid may be commercially available from Biomer, Inc. under the name BIOMER® L9000. The polylactic acid may also be commercially available from Natureworks LLC (NATUREWORKS®) or Mitsui Chemical (LACEA®). The polylactic acid may also be described in U.S. Patent Nos. 4,797,468, 5,470,944, 5,770,682, 5,821,327, 5,880,254, and 6,326,458, the entire contents of which are incorporated herein by reference for all purposes.

[0228] The melting temperature (Tm) of the polylactic acid may be about 100°C to about 240°C. The melting temperature of the polylactic acid may be about 120°C to about 220°C. The melting temperature of the polylactic acid may be about 140°C to about 200°C. The melting temperature of the polylactic acid may be about 140°C to about 180°C.

[0229] The crystallization temperature (Tc) of the polylactic acid may be about 50°C to about 80°C. The crystallization temperature of the polylactic acid may be about 55°C to about 75°C.

[0230] The glass transition temperature (Tg) of the polylactic acid may be about 20° C. to about 80° C. The glass transition temperature of the polylactic acid may be about 30° C. to about 70° C. The glass transition temperature of the polylactic acid may be about 40° C. to about 65° C. The melting temperature and the glass transition temperature may be measured by differential scanning calorimetry (DSC) according to ASTM D-3417.

[0231] The above polylactic acid has a melting temperature and a glass transition temperature within the above range, so that the biodegradable absorbent produced can have improved mechanical properties.

[0232] Fig. 2 is a schematic drawing of a filament including a core portion and a sheath portion according to an embodiment. Fig. 3 is a schematic drawing of a cross-section of a filament including a core portion and a sheath portion according to an embodiment.

[0233] Referring to FIGS. 2 and 3, the melt-blown layer (10) includes a filament including a core portion (12) and a sheath portion (13), wherein the core portion (12) includes the second biodegradable resin composition and has an extended shape, and the sheath portion (13) includes the first biodegradable resin composition and may have a shape surrounding the outer circumference of the core portion.

[0234] The core portion (12) may have a shape extending in one direction. The core portion (12) may have a cylindrical shape that continuously extends in the one direction.

[0235] The above-mentioned systole (13) surrounds the core portion (12). The above-mentioned systole (13) can be arranged on the outer surface of the core portion (12). The above-mentioned systole (13) can be in close contact with the outer surface of the core portion (12). The above-mentioned systole (13) can cover the entire outer surface of the core portion (12).

[0236] The diameter (D) of the core portion (12) may be about 1 µm to about 100 µm, about 1 µm to about 50 µm, or about 5 µm to about 50 µm.

[0237] The thickness (T) of the above-mentioned systole (13) may be about 0.5 µm to about 50 µm, about 2.5 µm to about 50 µm, or about 2.5 µm to about 30 µm.

[0238] Differently from this, the filament included in the melt-blown layer (10) may not have the structure of the core portion (12) and the sheath portion (13). The filament may have a single structure. The filament may have a single wire structure without a boundary distinction. The filament may have no boundary between the central portion and the outer portion.

[0239] The core portion (12) may include the second biodegradable resin composition as a main component, and the sheath portion (13) may include the first biodegradable resin composition as a main component. The core portion (12) may be made of the second biodegradable resin composition, and the sheath portion (13) may be made of the first biodegradable resin composition.

[0240] The first biodegradable resin composition and the second biodegradable resin composition may have different physical properties. For example, the first biodegradable resin composition may have more tackiness than the second biodegradable resin composition. The second biodegradable resin composition may have greater mechanical strength than the first biodegradable resin composition. In addition, the first biodegradable resin composition may be more flexible than the second biodegradable resin composition. In addition, the first biodegradable resin composition may have lower crystallinity than the second biodegradable resin composition.

[0241] Accordingly, the filament can have improved mechanical strength while also having improved bondability. The filament can have improved flexibility while also having improved mechanical strength.

[0242] The melt-blown layer (10) may contain the second biodegradable resin composition in an amount of about 30 parts by weight to about 300 parts by weight, 40 parts by weight to about 300 parts by weight, 50 parts by weight to about 300 parts by weight, or 50 parts by weight to about 250 parts by weight, based on 100 parts by weight of the first biodegradable resin composition.

[0243] Figure 4 is a schematic drawing of an apparatus for manufacturing a first biodegradable resin composition.

[0244] Referring to FIG. 4, the device may include a slurry stirrer (100), an esterification reaction unit (200), a polycondensation reaction unit (300), a post-treatment unit (400), a first recovery unit (510), and a second recovery unit (520).

[0245] The step of preparing the first biodegradable resin composition may include a step of preparing a slurry comprising the diol and the aromatic dicarboxylic acid.

[0246] The above step may include a step of mixing and treating the diol and the aromatic dicarboxylic acid.

[0247] The above step is a pretreatment step prior to the esterification reaction, and may be a step of mixing the diol and the aromatic dicarboxylic acid and forming a slurry therefrom. At this time, the diol may include a biomass-based diol component.

[0248] The above diol and the aromatic dicarboxylic acid can be introduced into the slurry mixer (100) and stirred to produce the slurry. By mixing and pretreating the diol and the aromatic dicarboxylic acid to form a slurry, not only can the diol and the aromatic dicarboxylic acid react uniformly, but it is also effective in rapidly proceeding the esterification reaction, thereby increasing the reaction efficiency. In particular, when the aromatic dicarboxylic acid has complete crystallinity and is in a powder form, such as terephthalic acid, its solubility in the diol may be very low, making it difficult for a homogeneous reaction to occur. Therefore, the pretreatment process of forming the slurry can play a very important role in realizing the excellent physical properties of the biodegradable nonwoven fabric according to the present invention.

[0249] When the aromatic dicarboxylic acid is terephthalic acid, the terephthalic acid is a white crystal that has complete crystallinity and sublimates at around 300°C under normal pressure without a melting point. Since the solubility in the diol is very low, it may be difficult for a homogeneous reaction to occur. Therefore, if a pretreatment process is performed prior to the esterification reaction, the surface area for reacting with the diol within the solid matrix of terephthalic acid can be increased, thereby inducing a homogeneous reaction.

[0250] When the aromatic dicarboxylic acid is dimethyl terephthalic acid, the dimethyl terephthalic acid can be made into a molten state at about 142°C to 170°C through the pretreatment process and reacted with the diol, thereby allowing the esterification reaction to proceed more quickly and efficiently.

[0251] Meanwhile, in the pretreatment step of manufacturing the slurry, the structure and properties of the first biodegradable resin composition may vary depending on the particle size, particle size distribution, pretreatment reaction conditions, etc. of the aromatic dicarboxylic acid.

[0252] The above aromatic dicarboxylic acid may include terephthalic acid. The above terephthalic acid may have an average particle diameter (D) measured by a particle size analyzer Microtrac S3500 in the particle size distribution (PSD). 50 ) may be 10 ㎛ to 400 ㎛, and the average particle diameter (D 50 ) may be less than or equal to 100. The standard deviation means the square root of the variance. The average particle diameter (D) of the terephthalic acid 50 ) may be 20 ㎛ to 200 ㎛, 30 ㎛ to 180 ㎛, or 50 ㎛ to 150 ㎛. The average particle diameter (D of the terephthalic acid 50 ) If the above range is satisfied, it may be more advantageous in terms of improved solubility and reaction speed for diol.

[0253] In the above pretreatment process, the diol and the aromatic dicarboxylic acid can be mixed and injected into the slurry mixer (100) (tank).

[0254] The above slurry agitator (100) may have an anchor type lower portion and a height of 20 mm or more to the agitator. In addition, having two or more rotating blades may be more advantageous in achieving an efficient agitation effect.

[0255] The above slurry stirrer (100) may have a height of 20 mm or more up to the stirrer, i.e., the reactor and the lowest part of the stirrer may be almost in contact, in which case a slurry may be obtained without sedimentation. If the shape, form, and rotating blade of the stirrer do not satisfy the above conditions, the aromatic dicarboxylic acid may settle to the bottom when the diol and the aromatic dicarboxylic acid are initially mixed, and in this case, phase separation may occur.

[0256] The pretreatment process for preparing the above slurry may include a step of mixing the diol and the aromatic dicarboxylic acid and stirring at about 50 rpm to about 200 rpm at about 30°C to about 100°C for 10 minutes or more, or 10 minutes to 200 minutes.

[0257] The above Dior may have the characteristics described above.

[0258] The above diol can be injected all at once or in divided doses.

[0259] The above diol may be separately introduced when mixing with the aromatic dicarboxylic acid and when mixing with the aliphatic dicarboxylic acid. The aromatic dicarboxylic acid may have the characteristics described above. In the pretreatment step of preparing the slurry, the molar ratio of the diol and the aromatic dicarboxylic acid may be from about 0.8:1 to about 1.2:1. In the pretreatment step of preparing the slurry, the molar ratio of the diol and the aromatic dicarboxylic acid may be from about 0.9:1 to about 1.1:1. When the diol is introduced in a greater amount than the aromatic dicarboxylic acid, the aromatic dicarboxylic acid may be easily dispersed.

[0260] The above step may include a step of producing a prepolymer by subjecting the slurry and the aliphatic dicarboxylic acid to an esterification reaction. The slurry and the aliphatic dicarboxylic acid may be reacted in the esterification reaction unit (200). In the esterification reaction, the reaction time may be shortened by using the slurry.

[0261] The slurry obtained in the above pretreatment step can shorten the reaction time of the esterification reaction by at least 1.5 times. The esterification reaction can be performed at least twice. A prepolymer that is input into the polycondensation process can be formed through the esterification reaction.

[0262] For example, the esterification reaction may proceed at once after the aliphatic dicarboxylic acid, or diol, and the aliphatic dicarboxylic acid are introduced into the slurry. That is, the slurry may be introduced into the esterification reactor, and the aliphatic dicarboxylic acid alone or the aliphatic dicarboxylic acid and the diol may be introduced into the esterification reaction unit (200), and the esterification reaction may proceed.

[0263] The esterification reaction may be carried out at about 250°C or lower for about 0.5 to about 5 hours. Specifically, the esterification reaction may be carried out at normal pressure or reduced pressure at about 180°C to about 250°C, about 185°C to about 240°C, or about 200°C to about 240°C until the amount of water as a byproduct theoretically reaches 95%. For example, the esterification reaction may be carried out for, but is not limited to, 0.5 to 5.5 hours, 0.5 to 4.5 hours, or 1 to 4 hours.

[0264] At least one of a polycarbonate diol and a polyether polyol may be mixed in the above slurry to allow a first esterification reaction to proceed. Alternatively, at least one of the polycarbonate diol and the polyether polyol may be introduced into a second esterification reaction.

[0265] In addition, after the first ester reaction, a mixture of the aliphatic dicarboxylic acid and the diol may be introduced into the esterification reaction unit (200), and a second ester reaction may proceed together with the first ester reaction product. In addition, at least one of the polycarbonate diol and the polyether polyol may be introduced into the second esterification reaction.

[0266] The first esterification reaction may be performed at 250°C or lower for 1.25 to 4 hours. Specifically, the first esterification reaction may be performed at normal pressure or reduced pressure at 180°C to 250°C, 185°C to 240°C, or 200°C to 240°C until the amount of water as a byproduct theoretically reaches 95%. For example, the first esterification reaction may be performed for 1.25 to 4 hours, 1.25 to 3.5 hours, or 2.5 to 3 hours, but is not limited thereto.

[0267] The second esterification reaction may be carried out at about 250°C or less for 0.25 to 3.5 hours. Specifically, the second esterification reaction may be carried out at normal pressure or reduced pressure at 180°C to 250°C, 185°C to 240°C, or 200°C to 240°C until the amount of water as a byproduct theoretically reaches 95%. For example, the second esterification reaction may be carried out for 0.5 to 3 hours, 1 to 2.5 hours, or 1.5 to 2.5 hours, but is not limited thereto.

[0268] When the above ester reaction is divided into the first ester reaction and the second ester reaction, the overall ester reaction can be precisely controlled. Accordingly, when the ester reaction is divided and carried out, the reaction stability and reaction uniformity of the ester reaction can be improved.

[0269] By the above esterification reaction, a prepolymer can be formed.

[0270] The number average molecular weight of the prepolymer may be from about 500 g / mol to about 10,000 g / mol. For example, the number average molecular weight of the prepolymer may be from about 500 g / mol to about 8,500 g / mol, from about 500 g / mol to about 8,000 g / mol, from about 500 g / mol to about 7,000 g / mol, from about 500 g / mol to about 5,000 g / mol, or from about 800 g / mol to about 3,000 g / mol. When the number average molecular weight of the prepolymer satisfies the above range, the molecular weight of the polymer can be efficiently increased in the condensation polymerization reaction.

[0271] The above number average molecular weight can be measured using gel permeation chromatography (GPC). Specifically, the data obtained by gel permeation chromatography includes various items such as Mn, Mw, and Mp, but among these, the molecular weight can be measured based on the number average molecular weight (Mn).

[0272] The above nucleating agent may be added together with the slurry before the esterification reaction.

[0273] The above nucleating agent can be introduced into the esterification reaction unit (200) during the esterification reaction.

[0274] The above nucleating agent can be added to the esterification reaction product after the esterification reaction.

[0275] The above nucleating agent can be introduced together with the above aliphatic dicarboxylic acid.

[0276] The nucleating agent may be introduced into the esterification reaction unit (200) after the first ester reaction and before the second ester reaction. Since the nucleating agent is introduced into the esterification reaction, the nucleating agent may be uniformly dispersed within the first biodegradable polyester resin. The nucleating agent may have the characteristics described above.

[0277] A titanium-based catalyst and / or a germanium-based catalyst may be used in the above esterification reaction. Specifically, the titanium-based catalyst and / or the germanium-based catalyst may be added to the slurry, and the esterification reaction may proceed.

[0278] Before the first esterification reaction, the titanium-based catalyst and / or the germanium-based catalyst may be added to the slurry, and the titanium-based catalyst and / or the germanium-based catalyst may be further added to the product of the first esterification reaction.

[0279] The content of the catalyst may be about 100 ppm to 2,000 ppm based on the total weight of the diol, aromatic dicarboxylic acid, and aliphatic dicarboxylic acid. For example, the catalyst may include 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 of a titanium-based catalyst or a germanium-based catalyst. When the content of the catalyst satisfies the above range, the physical properties can be further improved.

[0280] The heat stabilizer may be introduced together with the slurry before the esterification reaction. The heat stabilizer may be introduced into the esterification reaction unit (200) during the esterification reaction. The heat stabilizer may be introduced into the esterification reaction product after the esterification reaction. In addition, the heat stabilizer may be introduced together with the aliphatic dicarboxylic acid. In addition, the heat stabilizer may be introduced into the esterification reaction unit (200) after the first esterification reaction and before the second esterification reaction.

[0281] The characteristics of the above heat stabilizer may be as described above.

[0282] The content of the heat stabilizer may be 3,000 ppm or less based on the total weight of the diol, the aromatic dicarboxylic acid, and the aliphatic dicarboxylic acid. Specifically, 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 based on the total weight of the diol, the aromatic dicarboxylic acid, and the aliphatic dicarboxylic acid. When the content of the heat stabilizer satisfies the above range, it is possible to control deterioration of the polymer due to high temperature during the reaction process, thereby reducing the terminal groups of the polymer and improving the color.

[0283] After the esterification reaction is completed, at least one selected from the group consisting of additives such as silica, potassium, or magnesium, and color correcting agents such as cobalt acetate may be further added to the esterification reaction product. That is, after the esterification reaction is completed, the additive and / or color correcting agent may be added, stabilized, and then a polycondensation reaction may proceed. The additive and / or color correcting agent may be added after the esterification reaction is completed and introduced into the polycondensation reaction unit (300) together with the prepolymer.

[0284] The first recovery unit (510) can recover reaction by-products such as water from the esterification reaction unit (200). The first recovery unit (510) can recover by-products generated in the esterification reaction by applying vacuum pressure to the esterification reaction unit (200) or performing reflux.

[0285] The above step may include a step of subjecting the prepolymer to a polycondensation reaction. The polycondensation reaction may proceed as follows. The prepolymer may be introduced into the polycondensation reaction unit (300).

[0286] Thereafter, the polycondensation reaction can be carried out at about 180° C. to about 280° C. and 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., and 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.

[0287] The above polycondensation reaction may include a first polycondensation reaction and a second polycondensation reaction.

[0288] For example, the first polycondensation can be performed at about 260°C or less, about 250°C or less, 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 hour to about 3.5 hours, about 0.5 hour to about 3.0 hours, or about 0.5 hour to about 2.8 hours.

[0289] The secondary polycondensation may be performed 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 hour to about 4 hours, about 1 hour to about 3.5 hours, or about 1.5 hour to about 3.5 hours.

[0290] Before the polycondensation reaction, a titanium-based catalyst or a germanium-based catalyst may be further added to the prepolymer. In addition, before the polycondensation reaction, at least one selected from the group consisting of an additive such as silica, potassium, or magnesium; an amine-based stabilizer such as trimethyl phosphate, triphenyl phosphate, trimethylphosphine, phosphoric acid, phosphorous acid, or tetraethylene pentamine; and a polymerization catalyst such as antimony trioxide, antimony trioxide, or tetrabutyl titanate may be additionally added to the prepolymer.

[0291] The number average molecular weight of the polymer may be about 30,000 g / mol or greater. For example, the number average molecular weight of the polymer may be about 30,000 g / mol or greater, about 40,000 g / mol or greater, about 43,000 g / mol or greater, about 45,000 g / mol or greater, or about 50,000 g / mol to about 70,000 g / mol. When the number average molecular weight of the polymer satisfies the above range, the physical properties, impact resistance, durability, and formability can be further improved.

[0292] The second recovery unit (520) can recover reaction byproducts such as water from the polycondensation reaction unit (300). The second recovery unit (520) can apply vacuum pressure to the polycondensation reaction unit (300) and recover byproducts generated in the polycondensation reaction.

[0293] 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).

[0294] The chain extender may be added to the polymer. The polymer and the chain extender may be uniformly mixed and maintained at a temperature of about 200°C to about 260°C for about 1 minute to about 15 minutes.

[0295] The above step may include a step of producing pellets from the polymer. Specifically, the polymer may be cooled to about 15°C or less, about 10°C or less, or about 6°C or less, and then the cooled polymer may be cut to produce pellets. The cutting step may be performed using any pellet cutting machine used in the art without limitation, and the pellets may have various shapes. The method for cutting the pellets may use an underwater cutting method or a strand cutting method. The pellets may undergo an additional post-processing process. The pellets may be fed into the post-processing unit (400), and the post-processing process may be performed. The post-processing process may be performed within the post-processing unit (400). The pellets may be fed into the post-processing unit (400). Thereafter, the post-processing unit (400) may melt the fed pellets by frictional heat and re-extrude them. That is, the post-processing unit (400) may include an extruder, such as a twin-screw extruder. The temperature of the post-processing process may be about 230°C to about 270°C. The temperature of the post-processing process may be about 230°C to about 260°C. The temperature of the post-processing process may be about 240°C to about 265°C. The temperature of the post-processing process may be about 240°C to about 260°C. The post-processing process time may be about 30 seconds to about 3 minutes. The post-processing process time may be about 50 seconds to about 2 minutes. The post-processing process time may be about 1 minute to about 2 minutes. Thereafter, the resin extruded by the extruder may be cooled, cut, and processed into post-processed pellets. That is, the resin extruded from the extruder may be reprocessed into pellets through the cutting step described above. The crystallinity of the above pellets can be improved in the above post-processing process.Additionally, the content of residues contained in the pellets can be controlled in the post-treatment process. In particular, the content of oligomers contained in the pellets can be controlled by the post-treatment process. The content of residual solvent contained in the pellets can be controlled by the post-treatment process.

[0296] The above post-treatment process can appropriately control the crystallinity and mechanical properties of the first biodegradable resin composition.

[0297] After the above pellets are manufactured, the first biodegradable resin composition can be compounded with the second biodegradable resin composition described above.

[0298] The above absorbent layer (20) may include pulp fibers derived from non-wood biomass raw materials. By including pulp fibers derived from non-wood biomass raw materials in the absorbent layer (20), there is a CO2 emission reduction effect without a decrease in mechanical properties compared to wood biomass raw materials.

[0299] The above non-wood biomass raw material may include at least one of kenaf, hemp, rice, bagasse, bamboo, seaweed, corn stalks, corn cores, rice straw, rice husk, wheat straw, and sugarcane stalk.

[0300] The pulp fibers above may have a lignin content of 30 wt% or less, 25 wt% or less, 20 wt% or less, 18 wt% or less, 16 wt% or less, or 5 wt% to 15 wt%. When the above ranges are satisfied, the absorption layer (20) maintains its properties such as moisture absorption rate, moisture retention capacity, elastic recovery, and tensile strength, while having a CO2 emission reduction effect.

[0301] The size of the pulp fibers may be 1 μm to 475 μm, 5 μm to 450 μm, 10 μm to 400 μm, 20 μm to 375 μm, or 25 μm to 100 μm.

[0302] The above absorbent layer (20) may further include a superabsorbent in the form of fibers, particles, gels, etc. in addition to the pulp fibers.

[0303] The above biodegradable absorbent (1) may contain 15 to 99 wt% of the melt-blown layer (10) and 1 to 85 wt% of the absorbent layer (20).

[0304] The above biodegradable absorbent (1) may contain 20 to 99 wt% of the melt-blown layer (10) and 1 to 80 wt% of the absorbent layer (20).

[0305] The above biodegradable absorbent (1) may contain 30 wt% to 99 wt% of the melt-blown layer (10) and 1 wt% to 70 wt% of the absorbent layer (20).

[0306] The above biodegradable absorbent (1) may contain 40 to 99 wt% of the melt-blown layer (10) and 1 to 60 wt% of the absorbent layer (20).

[0307] The biodegradable absorbent (1) may comprise 45 wt% to 99 wt% of the melt-blown layer (10) and 1 wt% to 55 wt% of the absorbent layer (20). The biodegradable absorbent (1) may comprise 50 wt% to 99 wt% of the melt-blown layer (10) and 1 wt% to 50 wt% of the absorbent layer (20). The biodegradable absorbent (1) may comprise 40 wt% to 99 wt% of the melt-blown layer (10) and 1 wt% to 60 wt% of the absorbent layer (20).

[0308] The biodegradable absorbent (1) above may have a tensile elongation in the MD (longitudinal) direction of 20% to 80% and a tensile elongation in the CD (transverse) direction of 30% to 120% according to KSK ISO 9073-18. The biodegradable absorbent (1) may have a tensile elongation in the MD (longitudinal) direction of 20% to 70% and a tensile elongation in the CD (transverse) direction of 40% to 120%. The biodegradable absorbent (1) may have a tensile elongation in the MD (longitudinal) direction of 20% to 60% and a tensile elongation in the CD (transverse) direction of 55% to 120%. The biodegradable absorbent (1) may have a tensile elongation in the MD direction of more than 20% to 60% and a tensile elongation in the CD direction of 55% to 100%. The above biodegradable absorbent (1) may have a tensile elongation in the MD direction of 24% to 42% and a tensile elongation in the CD direction of 55% to 95%.

[0309] The biodegradable absorbent (1) may have a tensile strength in the MD direction of 0.50 kgf / 2.5 cm to 0.90 kgf / 2.5 cm and a tensile strength in the CD direction of 0.20 kgf / 2.5 cm to 0.60 kgf / 2.5 cm, based on KSK ISO 9073-18. The biodegradable absorbent (1) may have a tensile strength in the MD direction of 0.70 kgf / 2.5 cm to 0.85 kgf / 2.5 cm and a tensile strength in the CD direction of 0.25 kgf / 2.5 cm to 0.50 kgf / 2.5 cm, based on KSK ISO 9073-18. The biodegradable absorbent (1) may have a tensile strength in the MD direction of 0.75 kgf / 2.5 cm to 0.85 kgf / 2.5 cm and a tensile strength in the CD direction of 0.25 kgf / 2.5 cm to 0.35 kgf / 2.5 cm, based on KSK ISO 9073-18. The biodegradable absorbent (1) may have a tensile strength in the MD direction of 0.75 kgf / 2.5 cm to 0.85 kgf / 2.5 cm and a tensile strength in the CD direction of 0.30 kgf / 2.5 cm to 0.35 kgf / 2.5 cm, based on KSK ISO 9073-18.

[0310] The biodegradable absorbent (1) may have a static friction coefficient of 0.05 to 0.5 on the surface of the melt-blown layer (10) according to ASTM D 1894. The biodegradable absorbent (1) may have a static friction coefficient of 0.1 to 0.5 on the surface of the melt-blown layer (10) according to ASTM D 1894. The biodegradable absorbent (1) may have a static friction coefficient of 0.2 to 0.4 on the surface of the melt-blown layer (10) according to ASTM D 1894. The biodegradable absorbent (1) may have a static friction coefficient of 0.2 to 0.35 on the surface of the melt-blown layer (10). The biodegradable absorbent (1) may have a static friction coefficient of 0.2 to 0.3 on the surface of the melt-blown layer (10).

[0311] When the above range is satisfied, the tensile elongation and elasticity properties are excellent, and the resistance recovery properties due to external force are improved, so that the absorbent material formed between the melt-blown layers does not cause the problem of flying out. In addition, it can exhibit soft properties and the touch feeling can be improved when in contact with the body.

[0312] A biodegradable melt-blown resin composition according to the present invention comprises a first biodegradable polyester resin comprising a diol-derived unit, an aromatic dicarboxylic acid-derived unit, and an aliphatic dicarboxylic acid-derived unit.

[0313] The above melt-blown layer can be manufactured from the above biodegradable melt-blown resin composition.

[0314] The biodegradable melt-blown resin composition may further comprise a melt strength enhancer. The biodegradable melt-blown resin composition may further comprise a nucleating agent.

[0315] The above biodegradable melt blown resin composition may further include a second biodegradable polyester resin, wherein the second biodegradable polyester resin is selected from the group consisting of poly-3-hydroxybutyrate, poly-3-hydroxyvalerate, poly-3-hydroxyhexanoate, poly-3-hydroxyoctanoate, poly(3-hydroxybutyrate-co-3-hydroxyvalerate), poly(3-hydroxybutyrate-co-3-hydroxyhexanoate), poly(3-hydroxybutyrate-co-4-hydroxybutyrate), poly(3-hydroxybutyrate-co-3-valerate), poly(3-hydroxybutyrate-co-3-hydroxyundec-10-enoate), poly-3-hydroxyalkanoate), polylactic acid, polybutylene succinate, polybutylene adipate, It may include at least one selected from the group consisting of polybutylene succinate-adipate, polybutylene succinate-terephthalate, and polybutylene succinate adipate terephthalate.

[0316] The first biodegradable polyester resin, the melt strength enhancer, the nucleating agent, and the second biodegradable polyester resin may be the same as the first biodegradable polyester resin, melt strength enhancer, nucleating agent, and second biodegradable polyester resin described above.

[0317]

[0318] Hereinafter, the present invention will be described in more detail based on examples and comparative examples. However, the following examples and comparative examples are merely illustrative examples for further explaining the present invention, and the present invention is not limited to the following examples and comparative examples.

[0319]

[0320] Manufacturing example

[0321] <Manufacturing of pretreated nanocellulose>

[0322] Cellulose nanocrystals (NVC-100, manufacturer: Celluforce) in the form of dry powder having a particle size of about 1 ㎛ to about 50 ㎛ were dispersed in water at 1 wt%, and then ultrasonicated for 2 minutes at an output of 20,000 J / s using a tip-type ultrasonic disperser to produce pretreated nanocellulose.

[0323]

[0324] <PBAT 수지 제조>

[0325] PBAT #1 manufacturing

[0326] -Step 1: Obtaining slurry

[0327] In the absence of a catalyst, the pretreated nanocellulose, 1,4-butanediol (1,4-BDO) and terephthalic acid (TPA) according to the above manufacturing example were mixed and placed in a slurry tank. At this time, the D of the terephthalic acid (TPA) 50 is 130㎛.

[0328] Afterwards, the mixture introduced into the slurry tank was pretreated by stirring at 100 rpm at 60°C for 1 hour, and a slurry was obtained without phase separation.

[0329] - Step 2: Obtaining a prepolymer

[0330] The slurry obtained in the first step was fed into a reactor through a supply line, and 250 ppm of tetrabutyl titanate (Dupont, Tyzor TnBT product), a titanium-based catalyst, was fed into the reactor based on the total weight of the slurry, and then the first esterification reaction was performed at 220°C and atmospheric pressure for about 1 hour and 30 minutes until 95% of the by-product water was discharged.

[0331] Thereafter, 50 mol% of 1,4-butanediol (1,4-BDO) based on the total mole number of diol components, 50 mol% of adipic acid (AA) based on the total mole number of dicarboxylic acid components, and 200 ppm of tetrabutyl titanate (Dupont, Tyzor TnBT product), a titanium-based catalyst, based on the total weight of the diol components and dicarboxylic acid components, were added to the first esterification reaction product.

[0332] Afterwards, a secondary esterification reaction was performed at 220°C and atmospheric pressure for approximately 2 hours and 30 minutes until 95% of the by-product water was discharged, thereby producing a prepolymer.

[0333] - Step 3: Polycondensation reaction step

[0334] Based on the total weight of the prepolymer manufactured in the second step, 150 ppm of a titanium-based catalyst, tetrabutyl titanate (Dupont, Tyzor TnBT product) and 500 ppm of a triethylene phosphate stabilizer were added, and then stabilized for about 10 minutes.

[0335] Afterwards, a polycondensation reaction was performed for about 4 hours while lowering the pressure to about 0.5 torr in a disc ring type reactor. Thereafter, the polymer was cooled to 5°C and cut with a pellet cutter to obtain PBAT #1 pellets.

[0336]

[0337] PBAT #2 manufacturing

[0338] The second step prepolymer was manufactured in the same manner as the above PBAT #1 manufacturing process.

[0339] Afterwards, 200 ppm of tetrabutyl titanate (Dupont, Tyzor TnBT product), a titanium catalyst, and 450 ppm of triethylene phosphate stabilizer were added based on the total weight of the prepolymer manufactured in the second step, and then stabilized for about 10 minutes.

[0340] Afterwards, the polycondensation reaction was performed for about 4 hours while lowering the pressure to about 0.5 torr in a disc ring type reactor.

[0341] Thereafter, the compounded composition was cooled to 5°C and cut using a pellet cutter to obtain PBAT #2 pellets.

[0342]

[0343] Example - Preparation of biodegradable absorbent

[0344] Example 1

[0345] The biodegradable absorbent was manufactured using the coform method. Specifically, the PBAT #1 was introduced into two melt-blown manufacturing devices, and melt-blown filaments were formed from each of the two melt-blown manufacturing devices.

[0346] Separately, pulp fibers manufactured from kenaf, a non-wood biomass raw material, are transported, and each melt-blown filament is converged on the pulp fibers and then manufactured into a biodegradable absorbent through a calendaring process. A specific example of the coform method is described in Korean Patent No. 10-1777433 B1.

[0347]

[0348] Example 2

[0349] In the above Example 1, a biodegradable absorbent was manufactured by the same process as Example 1, except that PBAT #2 was used instead of PBAT #1.

[0350]

[0351] Comparative Example 1

[0352] In the above Example 1, a biodegradable absorbent was manufactured by the same process as Example 1, except that polypropylene (Basell Polyolefins, Metocene™) was used instead of PBAT #1, and coniferous wood chips, a woody biomass raw material, was used instead of kenaf, a non-woody biomass raw material.

[0353]

[0354] Experimental example

[0355] Experimental Example 1 - Tensile strength and tensile elongation

[0356] For each biodegradable absorbent manufactured in Examples 1 to 2 and Comparative Example 1, the tensile strength and tensile elongation in MD (longitudinal direction) and CD (transverse direction) were measured in accordance with KSK ISO9073-18, and the results are shown in Table 1 below.

[0357]

[0358] Experimental Example 2 - Coefficient of Static Friction

[0359] For each biodegradable absorbent manufactured in Examples 1 to 2 and Comparative Example 1, the coefficient of static friction for each melt-blown surface layer was measured in accordance with ASTM D 1894, and the average value of the measurement results is shown in Table 1 below.

[0360]

[0361] Experimental Example 3 - Biodegradability

[0362] For each biodegradable absorbent manufactured in Examples 1 to 2 and Comparative Example 1, the biodegradability was measured by measuring the amount of carbon dioxide generated according to KS M3100-1. Specifically, an inoculum container containing only compost manufactured in a compost factory was prepared, and a test container was prepared in which 5 wt% of the dry weight of the compost-based biodegradable absorbent was added to the compost. Thereafter, the containers were cultured for 180 days under conditions of a temperature of approximately 58±2°C, a moisture content of 50%, and an oxygen concentration of 6% or more. The carbon dioxide generated in each test container was captured and titrated with an aqueous phenolphthalein solution, thereby measuring the amount of carbon dioxide generated in each test container. The biodegradability was calculated using the measured amount of carbon dioxide generated according to the following calculation formula, and the results are shown in Table 1 below.

[0363] [Calculation formula]

[0364]

[0365]

[0366] Experimental Example 4 - Product Reliability Evaluation

[0367] Each biodegradable absorbent manufactured in Examples 1 to 2 and Comparative Example 1 was evaluated by tactile and visual evaluations by 10 subjects according to the evaluation criteria below. The average values ​​of the evaluation results of the 10 subjects are shown in Table 1 below.

[0368] - 5 points: No dust and smooth to the touch.

[0369] - 3 points: Less dust and soft to the touch.

[0370] - 1 point: A lot of dust or stiff to the touch.

[0371]

[0372] Unit of classificationExample 1Example 2Comparative example 1Tensile strengthMDkgf / 2.5cm0.700.800.74CD0.250.300.29Tensile elongationMD%284220CD579551Coefficient of static friction-0.60.40.5Biodegradability%959463Product reliability-351However, Examples 1 to 2 and Comparative Example 1 are based on 70GSM (Gram per Square Meter) weight.

[0373]

[0374] As can be seen in Table 1 above, the biodegradable absorbents according to Examples 1 and 2 do not cause environmental problems as biodegradation occurs after disposal due to the selection of a biodegradable polyester resin in the melt-blown layer.

[0375] In addition, the biodegradable polyester resin included in the biodegradable absorbent according to Examples 1 and 2 is selected to include a diol-derived unit, an aromatic dicarboxylic acid-derived unit, and an aliphatic dicarboxylic acid-derived unit, so that the tensile elongation and elasticity properties are excellent, and thus the resistance recovery properties due to external force can be improved. In addition, by improving the surface properties of the melt-blown layer, the melt-blown filament can exhibit soft properties, and the touch sensation can be improved when in contact with the body.

[0376]

[0377] The embodiment can be applied to a biodegradable absorbent having excellent biodegradability and mechanical properties and improved touch.

Claims

1. Multiple melt-blown layers; and An absorption layer disposed between the above melt-blown layers, The melt-blown layer comprises a first biodegradable resin composition, A biodegradable absorbent comprising a first biodegradable polyester resin comprising a diol-derived unit, an aromatic dicarboxylic acid-derived unit, and an aliphatic dicarboxylic acid-derived unit, wherein the first biodegradable resin composition comprises a first biodegradable polyester resin comprising a diol-derived unit, an aromatic dicarboxylic acid-derived unit, and an aliphatic dicarboxylic acid-derived unit.

2. In paragraph 1, A biodegradable absorbent, wherein the first biodegradable resin composition further comprises a nucleating agent.

3. In paragraph 1, The melt-blown layer further comprises a second biodegradable resin composition, wherein the second biodegradable resin composition comprises a second biodegradable polyester resin, The second biodegradable polyester resin is poly-3-hydroxybutyrate, poly-3-hydroxyvalerate, poly-3-hydroxyhexanoate, poly-3-hydroxyoctanoate, poly(3-hydroxybutyrate-co-3-hydroxyvalerate), poly(3-hydroxybutyrate-co-3-hydroxyhexanoate), poly(3-hydroxybutyrate-co-4-hydroxybutyrate), poly(3-hydroxybutyrate-co-3-valerate), poly(3-hydroxybutyrate-co-3-hydroxyundec-10-enoate), poly-3-hydroxyalkanoate), polylactic acid, polybutylene succinate, polybutylene adipate, polybutylene succinate-adipate, polybutylene succinate-terephthalate, A biodegradable absorbent comprising at least one member selected from the group consisting of polybutylene succinate adipate terephthalate.

4. In paragraph 1, A biodegradable absorbent material wherein the absorbent layer comprises pulp fibers derived from non-wood biomass raw materials.

5. In paragraph 4, A biodegradable absorbent wherein the pulp fiber has a lignin content of 30 wt% or less.

6. In paragraph 1, A biodegradable absorbent comprising the melt-blown layer in an amount of 15 to 99 wt% and the absorbent layer in an amount of 1 to 85 wt%.

7. In paragraph 1, A biodegradable absorbent having a melt index of 25 g / 10 min to 60 g / 10 min at 190°C, wherein the first biodegradable resin composition has a melt index of 25 g / 10 min to 60 g / 10 min.

8. In paragraph 1, The above biodegradable absorbent is a biodegradable absorbent having a tensile elongation in the MD direction of 20% to 80% and a tensile elongation in the CD direction of 30% to 120% according to KSK ISO 9073-18.

9. In paragraph 1, The above biodegradable absorbent is a biodegradable absorbent having a tensile strength in the MD direction of 0.50 kgf / 2.5 cm to 0.90 kgf / 2.5 cm and a tensile strength in the CD direction of 0.20 kgf / 2.5 cm to 0.60 kgf / 2.5 cm according to KSK ISO 9073-18.

10. In paragraph 1, The above biodegradable absorbent is a biodegradable absorbent having a static friction coefficient of the melt-blown layer surface of 0.05 to 0.5 according to ASTM D 1894.

11. A biodegradable melt-blown resin composition comprising a first biodegradable polyester resin comprising a diol-derived unit, an aromatic dicarboxylic acid-derived unit, and an aliphatic dicarboxylic acid-derived unit.

12. In paragraph 11, A biodegradable melt-blown resin composition further comprising a melt strength enhancer.

13. In paragraph 11, A biodegradable melt-blown resin composition further comprising a nucleating agent.

14. In paragraph 11, The above biodegradable melt blown resin composition further comprises a second biodegradable polyester resin, The second biodegradable polyester resin is poly-3-hydroxybutyrate, poly-3-hydroxyvalerate, poly-3-hydroxyhexanoate, poly-3-hydroxyoctanoate, poly(3-hydroxybutyrate-co-3-hydroxyvalerate), poly(3-hydroxybutyrate-co-3-hydroxyhexanoate), poly(3-hydroxybutyrate-co-4-hydroxybutyrate), poly(3-hydroxybutyrate-co-3-valerate), poly(3-hydroxybutyrate-co-3-hydroxyundec-10-enoate), poly-3-hydroxyalkanoate), polylactic acid, polybutylene succinate, polybutylene adipate, polybutylene succinate-adipate, polybutylene succinate-terephthalate, A biodegradable melt-blown resin composition comprising at least one selected from the group consisting of polybutylene succinate adipate terephthalate.

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