Biodegradable resin composition for injection molding and paint container comprising same

Abstract

The present invention provides a biodegradable resin composition for injection and a paint container comprising same, the biodegradable resin composition comprising: a biodegradable resin including an aliphatic-aromatic polyester resin and an aliphatic polyester resin; an inorganic filler including calcium carbonate; a plasticizer; and a heat stabilizer, wherein the biodegradable resin composition has a melt index of greater than 24 g / 10 min, as measured at 190°C and 2.16 kg according to ASTM D1238.

Description

Biodegradable resin composition for injection molding and paint container containing the same

[0001] The present invention relates to a biodegradable resin composition for injection and a paint container comprising the same.

[0002]

[0003] With growing concerns about environmental issues, solutions are being sought for the disposal of various household goods, especially disposable products. Specifically, petroleum-based polymer materials are widely used in the manufacture of various products such as films, fibers, packaging materials, bottles, and containers due to their low cost and excellent processability. However, when incinerated at the end of their useful life, they emit hazardous substances, and depending on the type, they can take hundreds of years to completely decompose naturally.

[0004] To overcome the limitations of these petroleum-based polymer materials, active research is being conducted on biodegradable resins that decompose in a relatively short period of time. Biodegradable resins such as polylactic acid (PLA), polybutyleneadipate terephthalate (PBAT), and polybutylene succinate (PBS) are being introduced as alternatives.

[0005] However, PLA has limited flexibility, and PBAT has poor mechanical properties, limiting its use. In particular, when the biodegradable resin is used as a paint container, there was a problem that it was difficult to demonstrate functionality as a paint container due to poor mechanical strength compared to conventional plastic materials. In addition, due to the nature of the biodegradable resin, it was vulnerable to heat, and there was a problem with high-temperature stability, such as color change due to deterioration. In addition, although paint containers can generally be manufactured by an injection molding process, there were limitations in ensuring injection molding processability due to the chemical and physical properties of the biodegradable resin.

[0006]

[0007] The present invention provides a biodegradable resin composition for injection molding, which is suitable for an injection molding process and has excellent mechanical properties and high-temperature stability, and a paint container comprising the same.

[0008]

[0009] The biodegradable resin composition for injection molding according to the present invention comprises a biodegradable resin including an aliphatic-aromatic polyester resin and an aliphatic polyester resin, an inorganic filler including calcium carbonate, a plasticizer, and a heat stabilizer, and has a melt index of more than 24 g / 10 min at 190°C and 2.16 kg according to ASTM D1238.

[0010] In one embodiment of the present invention, the aliphatic-aromatic polyester resin may have a melt index at 190° C. and 2.16 kg of more than 20 g / 10 min and less than 50 g / 10 min according to ASTM D1238.

[0011] In one embodiment of the present invention, the content of the aliphatic polyester resin may be more than 20 wt % and less than 40 wt % based on the total weight of the biodegradable resin composition for injection.

[0012] In one embodiment of the present invention, the content of the inorganic filler may be more than 20 wt % and less than 30 wt % based on the total weight of the biodegradable resin composition for injection.

[0013] In one embodiment of the present invention, the content of the plasticizer may be more than 0 wt % and less than 2 wt % based on the total weight of the biodegradable resin composition for injection.

[0014] In one embodiment of the present invention, the biodegradable resin composition for injection may include a phosphate ester-based antioxidant.

[0015] In one embodiment of the present invention, the biodegradable resin composition for injection may include an active agent including calcium.

[0016] In one embodiment of the present invention, the biodegradable resin composition for injection molding may have a weight change rate at 200°C of less than 1.8% compared to the initial weight according to thermogravimetric analysis (TGA).

[0017] A paint container according to the present invention comprises an injection-molded biodegradable resin composition comprising an aliphatic-aromatic polyester resin and a biodegradable resin including an aliphatic polyester resin, an inorganic filler including calcium carbonate, a plasticizer, and a heat stabilizer, wherein the injection-molded biodegradable resin composition has a melt index of more than 24 g / 10 min at 190° C. and 2.16 kg according to ASTM D1238.

[0018] In one embodiment of the present invention, the paint container may have an Izod impact strength of more than 8 kgf·cm / cm and less than 30 kgf·cm / cm according to ASTM D256.

[0019] In one embodiment of the present invention, the paint container has a tensile strength of 200 kgf / cm according to ASTM D638. 2 Exceeding 250 kgf / cm 2 It may be less than.

[0020] In one embodiment of the present invention, the paint container has a flexural strength of 220 kgf / cm according to ASTM D790. 2 Exceeding 350 kgf / cm 2 It may be less than.

[0021] In one embodiment of the present invention, the paint container has a flexural modulus of 9,100 kgf / cm according to ASTM D790. 2 Exceeding 12,000 kgf / cm 2 It may be less than.

[0022]

[0023] The resin composition according to the present invention comprises a biodegradable resin. Therefore, paint containers manufactured from the resin composition can be easily decomposed after disposal. Furthermore, the biodegradable resin comprises an aliphatic-aromatic polyester resin and an aliphatic polyester resin, which have complementary properties. Therefore, the mechanical properties of the paint container, such as flexural modulus, flexural strength, tensile strength, and impact strength, can be improved following an injection molding process.

[0024] The resin composition according to the present invention includes an inorganic filler including calcium carbonate. This improves the flowability of the biodegradable resin without degrading the mechanical properties of the paint container during the injection molding process, thereby enabling injection molding processability, such as injection temperature, injection pressure, and cooling conditions, to be achieved when manufacturing an injection molded product.

[0025] The resin composition according to the present invention includes a heat stabilizer. This improves high-temperature stability, thereby minimizing color and weight changes due to deterioration of the biodegradable resin.

[0026] The resin composition according to the present invention includes a plasticizer and has a melt index controlled within a specific range. This prevents the mechanical properties of the paint container from being degraded during the injection molding process, while also allowing for the smooth discharge of impurities such as gas from within the mold during the injection molding process, thereby improving the stability of the injection molding process.

[0027]

[0028] 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.

[0029] 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 properties, dimensions, etc. of the components described in this specification or application are to be understood as being modified by the term "about" in all cases, unless otherwise specified.

[0030] 'ppm' in this specification or application means weight basis.

[0031] The description of “A and / or B” in this specification or application means “A, B, or A and B.”

[0032]

[0033] The biodegradable resin composition for injection according to the present invention comprises a biodegradable resin including an aliphatic-aromatic polyester resin and an aliphatic polyester resin.

[0034] The above aliphatic-aromatic polyester resin may include a diol-derived unit, an aliphatic dicarboxylic acid-derived unit, and an aromatic dicarboxylic acid-derived unit.

[0035] The above diol may be an aliphatic diol. The above diol may be a bio-derived diol. The above diols are ethanediol, 1,2-propanediol, 1,3-propanediol, 2-methyl-1,3-propanediol, 2,2-dimethyl-1,3-propanediol, 2,2-diethyl-1,3-propanediol, 2-ethyl-2-isobutyl-1,3-propanediol, 1,2-butanediol, 1,4-butanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 2,2,4-trimethyl-1,3-pentanediol, 1,6-hexanediol, 2-ethyl-1,3-hexanediol, 2,4-dimethyl-2-ethyl-1,3-hexanediol, 2,2,4-trimethyl-1,6-hexanediol, 2-methyl-1,8-octanediol, At least one may be selected from the group consisting of 1,9-nonanediol, 1,10-decanediol and 1,12-octadecanediol or derivatives thereof.

[0036] 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. The above diol may be selected from the group consisting of 1,4-butanediol, 1,2-ethanediol, 1,3-propanediol or derivatives thereof. The above diol may include 1,4-butanediol or a derivative thereof.

[0037] The aliphatic dicarboxylic acid may be at least one selected from the group consisting of oxalic acid, malonic acid, succinic acid, maleic acid, fumaric acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, dodecanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid or derivatives thereof. The aliphatic dicarboxylic acid may be at least one selected from the group consisting of adipic acid, succinic acid, sebacic acid or derivatives thereof. The aliphatic dicarboxylic acid may include adipic acid or a derivative thereof.

[0038] 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. The above aromatic dicarboxylic acid may be at least one selected from the group consisting of terephthalic acid, dimethyl terephthalate, 2,6-naphthalene dicarboxylic acid, isophthalic acid, or derivatives thereof. The above aromatic dicarboxylic acid may include terephthalic acid, dimethyl terephthalate, or derivatives thereof.

[0039] In the above aliphatic-aromatic polyester resin, the molar ratio of the total diol residues including the diol and the total dicarboxylic acid residues including the aromatic dicarboxylic acid and the aliphatic dicarboxylic acid may be from about 1:0.9 to about 1:1.1, or from about 1:0.95 to about 1:1.05.

[0040] In the above aliphatic-aromatic polyester resin, the molar ratio of the aromatic dicarboxylic acid residue and the aliphatic dicarboxylic acid residue may be from about 3:7 to about 7:3, from about 3.3:6.7 to about 6.7:3.3, from about 4:6 to about 6:4, or from about 4.2:5.8 to about 5:5.

[0041] The above aliphatic-aromatic polyester resin may include a diol residue derived from 1,4-butanediol in an amount of about 90 mol% or more, about 95 mol% or more, or about 98 mol% or more based on the total diol.

[0042] The above aliphatic-aromatic polyester resin may include aromatic dicarboxylic acid residues derived from terephthalic acid or dimethyl terephthalate in an amount of about 30 mol% to about 70 mol%, about 35 mol% to about 65 mol%, about 40 mol% to about 60 mol%, or about 43 mol% to about 53 mol% based on the total dicarboxylic acid.

[0043] The above aliphatic-aromatic polyester resin may include an aliphatic dicarboxylic acid residue derived from adipic acid in an amount of about 30 mol% to about 70 mol%, about 35 mol% to about 65 mol%, about 40 mol% to about 60 mol%, or about 47 mol% to about 57 mol% based on the total dicarboxylic acid.

[0044] The aliphatic-aromatic polyester resin may include a first block and a second block. The aliphatic-aromatic polyester resin may have a molecular structure in which the first block and the second block are alternately bonded.

[0045] 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.

[0046] 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.

[0047] In the aliphatic-aromatic polyester resin, the ratio (X / Y) of the number of the first blocks (X) to the number of the second blocks (Y) may be about 0.5 to about 1.5, about 0.6 to about 1.4, about 0.7 to about 1.3, about 0.75 to about 1.2, or about 0.8 to about 1. The number of the first blocks may be smaller than the number of the second blocks. The number of the first blocks may be about 30 to about 300, about 40 to about 250, about 50 to about 220, about 60 to about 200, about 70 to about 200, or about 75 to about 200. The number of the first blocks may vary depending on the content of the aromatic dicarboxylic acid, the molecular weight of the aliphatic-aromatic polyester resin, and the degree of alternation described below. That is, as the molar ratio of the aromatic dicarboxylic acid increases, as the molecular weight of the aliphatic-aromatic polyester resin increases, and as the degree of alternation described below increases, the number of the first blocks may increase.

[0048] The number of the second blocks may be about 30 to about 300, about 40 to about 250, about 50 to about 220, about 60 to about 200, about 70 to about 200, or about 75 to about 200. The number of the second blocks may vary depending on the content of the aliphatic dicarboxylic acid, the molecular weight of the aliphatic-aromatic polyester resin, and the degree of alternation described below.

[0049] When the aliphatic-aromatic polyester resin includes the first block and the second block in the above range, a paint container including the aliphatic-aromatic polyester resin can have improved biodegradability while having appropriate mechanical strength.

[0050] The above aliphatic-aromatic polyester resin may include the following bonding structures 1 to 3.

[0051] [Combination Structure 1]

[0052] - Aromatic dicarboxylic acids - Diols - Aliphatic dicarboxylic acids -

[0053] [Combination Structure 2]

[0054] - Aromatic dicarboxylic acid - Diol - Aromatic dicarboxylic acid -

[0055] [Combination Structure 3]

[0056] - Aliphatic dicarboxylic acid - Diol - Aliphatic dicarboxylic acid -

[0057] The diol included in the above bonding structure 1 is bonded between the aromatic dicarboxylic acid and the aliphatic dicarboxylic acid, and to the aromatic dicarboxylic acid and the aliphatic dicarboxylic acid. The diol included in the above bonding structure 1 can be directly esterified between the aromatic dicarboxylic acid and the aliphatic dicarboxylic acid, and to the aromatic dicarboxylic acid and the aliphatic dicarboxylic acid.

[0058] The diol included in the above bonding structure 2 is bonded between the aromatic dicarboxylic acid and the aromatic dicarboxylic acid, and to the aromatic dicarboxylic acid and the aromatic dicarboxylic acid. The diol included in the above bonding structure 2 can be directly esterified between the aromatic dicarboxylic acid and the aromatic dicarboxylic acid, and to the aromatic dicarboxylic acid and the aromatic dicarboxylic acid.

[0059] The diol included in the above bonding structure 3 is bonded between the aliphatic dicarboxylic acid and the aliphatic dicarboxylic acid, and to the aliphatic dicarboxylic acid and the aliphatic dicarboxylic acid. The diol included in the above bonding structure 3 can be directly esterified between the aliphatic dicarboxylic acid and the aliphatic dicarboxylic acid and the aliphatic dicarboxylic acid.

[0060] The above aliphatic-aromatic polyester resin may have an alternating ratio. The alternating ratio is the ratio of the diol bonded between the aromatic dicarboxylic acid and the aliphatic dicarboxylic acid among the diols. That is, the alternating ratio may be the ratio of the diol included in the bonding structure 1 among the diols. The alternating ratio may be a value obtained by dividing the number of moles of the diol included in the bonding structure 1 by the sum of the number of moles of the diol included in the bonding structure 1, the number of moles of the diol included in the bonding structure 2, and the number of moles of the diol included in the bonding structure 3.

[0061] The above-mentioned exchange ratio may be the ratio of diols bonded between heterodicarboxylic acids among the total diols.

[0062] The above exchange ratio can be calculated using the following formula 1.

[0063] [Formula 1]

[0064]

[0065] In the above formula 1, DM1 is the molar ratio of the diol included in the bonding structure 1, DM2 is the molar ratio of the diol included in the bonding structure 2, and DM3 is the molar ratio of the diol included in the bonding structure 3.

[0066] In the above aliphatic-aromatic polyester resin, the alternation ratio may be about 0.3 to about 0.7, about 0.37 to about 0.59, about 0.4 to about 0.56, or about 0.45 to about 0.53.

[0067] The above aliphatic-aromatic polyester resin may include a hard segment. The hard segment ratio is the ratio of the diol bonded between the aromatic dicarboxylic acid and the aromatic dicarboxylic acid among the diols.

[0068] The above hard segment ratio may be the molar ratio of the diol included in the bonding structure 2 among the total diols. The above hard segment ratio may be a value obtained by dividing the number of moles of the diol included in the bonding structure 2 by the sum of the number of moles of the diol included in the bonding structure 1, the number of moles of the diol included in the bonding structure 2, and the number of moles of the diol included in the bonding structure 3.

[0069] The above hard segment ratio can be expressed by the following equation 2.

[0070] [Formula 2]

[0071]

[0072] In the above formula 2, DM1 is the molar ratio of the diol included in the bonding structure 1, DM2 is the molar ratio of the diol included in the bonding structure 2, and DM3 is the molar ratio of the diol included in the bonding structure 3.

[0073] The hard segment ratio may be from about 0.15 to about 0.35, from about 0.2 to about 0.3, from about 0.21 to about 0.29, or from about 0.22 to about 0.28.

[0074] The above aliphatic-aromatic polyester resin may include a soft segment.

[0075] The above soft segment ratio is the ratio of the diol bonded between the aliphatic dicarboxylic acid and the aliphatic dicarboxylic acid among the diols.

[0076] The above soft segment ratio may be the molar ratio of the diol included in the bonding structure 3 among the total diols. The above soft segment ratio may be a value obtained by dividing the number of moles of the diol included in the bonding structure 3 by the sum of the number of moles of the diol included in the bonding structure 1, the number of moles of the diol included in the bonding structure 2, and the number of moles of the diol included in the bonding structure 3.

[0077] The above soft segment ratio can be expressed by the following equation 3.

[0078] [Formula 3]

[0079]

[0080] In the above formula 3, DM1 is the molar ratio of the diol included in the bonding structure 1, DM2 is the molar ratio of the diol included in the bonding structure 2, and DM3 is the molar ratio of the diol included in the bonding structure 3.

[0081] The soft segment ratio may be from about 0.16 to about 0.36, from about 0.21 to about 0.31, from about 0.22 to about 0.30, or from about 0.23 to about 0.29.

[0082] The above soft segment ratio may be greater than the above hard segment ratio.

[0083] The ratio of the hard segment to the soft segment may be about 0.92 to about 0.99. That is, the value obtained by dividing the DM2 by the DM3 may be about 0.92 to about 0.99.

[0084] The above-mentioned alternation ratio, the hard segment ratio, and the soft segment ratio can be measured by nuclear magnetic resonance spectroscopy. The aliphatic-aromatic polyester resin is dissolved in a solvent such as CDCl3, and at room temperature, by a nuclear magnetic resonance (NMR) device, 1 H-NMR and / or 13 It can be analyzed by C-NMR analysis.

[0085] When the diol is 1,4-butanediol, the aromatic dicarboxylic acid is terephthalic acid or dimethyl terephthalate, and the aliphatic dicarboxylic acid is adipic acid, the analysis of the aliphatic-aromatic polyester resin by nuclear magnetic resonance spectroscopy may include a first peak, a second peak, a third peak, a fourth peak, a fifth peak, a sixth peak, a seventh peak, an eighth peak, a ninth peak, a tenth peak, and an eleventh peak.

[0086] When the diol is 1,4-butanediol, the aromatic dicarboxylic acid is terephthalic acid or dimethyl terephthalate, and the aliphatic dicarboxylic acid is adipic acid, analysis of the aliphatic-aromatic polyester resin by nuclear magnetic resonance spectroscopy may include a peak derived from the diol of the bonding structure 1, a peak derived from the diol of the bonding structure 2, and a peak derived from the bonding structure 3 at about 3.5 ppm to about 4.6 ppm.

[0087] In the range of about 3.5 ppm to about 4.6 ppm, the first peak, the second peak, the third peak, and the fourth peak may be defined in order from high ppm to low ppm. In addition, based on the ppm of the ninth peak, the first peak, the second peak, the third peak, and the fourth peak may be defined in order from high ppm to low ppm in the range of about -3.4 ppm to about -4.3 ppm.

[0088] -ppm direction can be upfield or shielded. For example, -3.4 ppm can mean 3.4 ppm upfield. For example, -3.4 ppm can mean 3.4 ppm shielded.

[0089] Analysis of the aliphatic-aromatic polyester resin by the nuclear magnetic resonance spectroscopy may include a peak derived from the diol of the bonding structure 1, a peak derived from the diol of the bonding structure 2, and a peak derived from the bonding structure 3 at about 1.0 ppm to about 2.5 ppm.

[0090] In the range of about 1.0 ppm to about 2.5 ppm, the tenth peak, the fifth peak, the sixth peak, the seventh peak, the eighth peak, and the eleventh peak may be defined in order from high ppm to low ppm. In the range of about -6.0 ppm to about -6.7 ppm based on the ppm of the ninth peak, the fifth peak, the sixth peak, the seventh peak, the eighth peak, and the eleventh peak may be defined in order from high ppm to low ppm.

[0091] In the range of about 7.5 ppm to about 8.5 ppm, the ninth peak may be formed. The ninth peak may be derived from the aromatic dicarboxylic acid. The ninth peak may be derived from an aromatic ring included in the aromatic dicarboxylic acid. The ninth peak may be derived from an aromatic ring included in the terephthalic acid or dimethyl terephthalate.

[0092] The above tenth peak and the above eleventh peak may be derived from the aliphatic dicarboxylic acid. The above tenth peak and the above eleventh peak may be derived from the adipic acid.

[0093] The first peak may be located at about -3.6 ppm to about -3.68 ppm based on the ppm of the ninth peak. The second peak may be located at about -3.69 ppm to about -3.75 ppm based on the ppm of the ninth peak. The third peak may be located at about -3.9 ppm to about -3.97 ppm based on the ppm of the ninth peak. The fourth peak may be located at about -3.98 ppm to about -4.1 ppm based on the ppm of the ninth peak. The fifth peak may be located at about -6.0 ppm to about -6.19 ppm based on the ppm of the ninth peak. The sixth peak may be located at about -6.2 ppm to about -6.26 ppm based on the ppm of the ninth peak. The seventh peak may be located at about -6.27 ppm to about -6.34 ppm based on the ppm of the ninth peak. The eighth peak may be located at about -6.35 ppm to about -6.42 ppm based on the ppm of the ninth peak. The tenth peak may be located at about -5.6 ppm to about -5.8 ppm based on the ppm of the ninth peak. The eleventh peak may be located at about -6.421 ppm to about -6.5 ppm based on the ppm of the ninth peak. The positions based on the ppm of the ninth peak may be the positions of each peak when the position of the ninth peak is 0 ppm.

[0094] The areas of the first peak, the second peak, the third peak, the fourth peak, the fifth peak, the sixth peak, the seventh peak, the eighth peak, the tenth peak, and the eleventh peak can be normalized based on the area of ​​the ninth peak. That is, when the area of ​​the ninth peak is 1, the areas of the first peak, the second peak, the third peak, the fourth peak, the fifth peak, the sixth peak, the seventh peak, the eighth peak, the tenth peak, and the eleventh peak can be relatively determined.

[0095] The above exchange ratio can be derived from the following equation 4 or equation 5.

[0096] [Formula 4]

[0097]

[0098] In the above formula 4, the PA1 is the area of ​​the first peak, the PA2 is the area of ​​the second peak, the PA3 is the area of ​​the third peak, and the PA4 is the area of ​​the fourth peak.

[0099] [Formula 5]

[0100]

[0101] In the above formula 5, the PA5 is the area of ​​the fifth peak, the PA6 is the area of ​​the sixth peak, the PA7 is the area of ​​the seventh peak, and the PA8 is the area of ​​the eighth peak.

[0102] The above hard segment ratio can be derived from the following equation 6 or equation 7.

[0103] [Formula 6]

[0104]

[0105] In the above formula 6, the PA1 is the area of ​​the first peak, the PA2 is the area of ​​the second peak, the PA3 is the area of ​​the third peak, and the PA4 is the area of ​​the fourth peak.

[0106] [Formula 7]

[0107]

[0108] In the above formula 7, the PA5 is the area of ​​the fifth peak, the PA6 is the area of ​​the sixth peak, the PA7 is the area of ​​the seventh peak, and the PA8 is the area of ​​the eighth peak.

[0109] The above soft segment ratio can be derived using Equation 8 or Equation 9 below.

[0110] [Formula 8]

[0111]

[0112] In the above formula 8, the PA1 is the area of ​​the first peak, the PA2 is the area of ​​the second peak, the PA3 is the area of ​​the third peak, and the PA4 is the area of ​​the fourth peak.

[0113] [Formula 9]

[0114]

[0115] In the above formula 9, the PA5 is the area of ​​the fifth peak, the PA6 is the area of ​​the sixth peak, the PA7 is the area of ​​the seventh peak, and the PA8 is the area of ​​the eighth peak.

[0116] The area of ​​the first peak may be about 0.35 to about 0.6, about 0.4 to about 0.55, about 0.43 to about 0.5, about 0.43 to about 0.52, or about 0.45 to about 0.49. The area of ​​the second peak may be about 0.37 to about 0.57, about 0.41 to about 0.54, about 0.45 to about 0.53, about 0.45 to about 0.55, or about 0.47 to about 0.53. The area of ​​the third peak may be about 0.37 to about 0.57, about 0.41 to about 0.54, about 0.45 to about 0.53, about 0.45 to about 0.55, or about 0.47 to about 0.53. The area of ​​the fourth peak may be about 0.4 to about 0.7, about 0.45 to about 0.65, about 0.48 to about 0.6, about 0.48 to about 0.60, or about 0.50 to about 0.58. The area of ​​the fifth peak may be about 0.35 to about 0.6, about 0.4 to about 0.55, about 0.43 to about 0.53, about 0.43 to about 0.52, or about 0.45 to about 0.49. The area of ​​the sixth peak may be about 0.35 to about 0.6, about 0.4 to about 0.55, about 0.43 to about 0.5, about 0.45 to about 0.55, or about 0.47 to about 0.53. The area of ​​the seventh peak may be about 0.41 to about 0.71, about 0.45 to about 0.65, about 0.48 to about 0.6, about 0.45 to about 0.55, or about 0.47 to about 0.53. The area of ​​the eighth peak may be about 0.4 to about 0.7, about 0.45 to about 0.65, about 0.48 to about 0.6, or about 0.50 to about 0.58. The area of ​​the tenth peak may be about 0.7 to about 2.5, about 0.75 to about 2, about 0.8 to about 1.5, about 1.0 to about 1.15, or about 1.02 to about 1.13. The area of ​​the eleventh peak may be about 0.It may be from about 7 to about 3.5, from about 0.7 to about 3, from about 0.8 to about 2.5, from about 1.0 to about 1.15, or from about 1.02 to about 1.13.

[0117] The sum of the area of ​​the first peak, the area of ​​the second peak, the area of ​​the third peak, and the area of ​​the fourth peak may be from about 1.49 to about 2.44, from about 1.81 to about 2.16, from about 1.9 to about 2.2, or from about 1.95 to about 2.1. Here, the sum of the area of ​​the first peak, the area of ​​the second peak, the area of ​​the third peak, and the area of ​​the fourth peak may refer to the sum of the total number of ester bonds based on the number of terephthalic acids. The sum of the area of ​​the second peak and the area of ​​the third peak may be from about 0.95 to about 1.10, or from about 0.98 to about 1.07. Here, the sum of the area of ​​the first peak and the area of ​​the third peak may refer to the extent of extension of the molecular bond of the aliphatic-aromatic polyester resin. The ratio of the area of ​​the fourth peak to the area of ​​the first peak (area of ​​the fourth peak / area of ​​the first peak) may be from about 1.1 to about 1.3, from about 0.67 to about 2, from about 0.96 to about 1.40, or from about 1.15 to about 1.25. The ratio of the area of ​​the fourth peak to the area of ​​the first peak may refer to the ratio of the soft segment to the hard segment within the molecular structure of the aliphatic-aromatic polyester resin. That is, the higher the ratio of the area of ​​the fourth peak to the area of ​​the first peak, the more the aliphatic-aromatic polyester resin may have improved adhesive properties. The ratio of the area of ​​the fourth peak to the area of ​​the third peak (area of ​​the fourth peak / area of ​​the third peak) may be from about 0.7 to about 1.89, from about 0.91 to about 1.33, from about 1.0 to about 1.2, or from about 1.01 to about 1.1. The ratio of the area of ​​the first peak to the area of ​​the second peak (area of ​​the first peak / area of ​​the second peak) may be from about 0.61 to about 1.62, from about 0.81 to about 1.11, from about 0.85 to about 0.95, or from about 0.86 to about 0.It may be 94. The ratio of the area of ​​the fifth peak to the area of ​​the first peak (area of ​​the fifth peak / area of ​​the first peak) may be about 0.61 to about 1.71, about 0.96 to about 1.40, about 0.8 to about 1.2, or about 0.9 to about 1.1. The ratio of the area of ​​the sixth peak to the area of ​​the second peak (area of ​​the sixth peak / area of ​​the second peak) may be about 0.58 to about 1.71, about 0.86 to about 1.16, about 0.8 to about 1.2, or about 0.9 to about 1.1. The ratio of the area of ​​the seventh peak to the area of ​​the third peak (area of ​​the seventh peak / area of ​​the third peak) may be about 0.72 to about 1.92, about 0.91 to about 1.33, about 0.8 to about 1.2, or about 0.9 to about 1.1. The ratio of the area of ​​the eighth peak to the area of ​​the fourth peak (area of ​​the eighth peak / area of ​​the fourth peak) may be about 0.59 to about 1.75, about 0.80 to about 1.2, or about 0.9 to about 1.1.

[0118] The number average molecular weight of the above aliphatic-aromatic polyester resin may be 20,000 g / mol to 100,000 g / mol, 20,000 g / mol to 80,000 g / mol, 20,000 g / mol to 70,000 g / mol, or 30,000 g / mol to 62,000 g / mol. When the above range is satisfied, injection processability may be improved while having appropriate biodegradability. The number average molecular weight may be measured using gel permeation chromatography (GPC).

[0119] The crystallinity of the above aliphatic-aromatic polyester resin may be 10% to 30%, 10% to less than 30%, 12% to less than 30%, 12% to 28%, or 15% to 25%. When the above range is satisfied, the release property may be improved during the injection molding process.

[0120] The above crystallinity is measured by melting enthalpy (ΔH) using differential scanning calorimetry (DSC) according to ASTM D-3417. m ) is the melting enthalpy (ΔH) at 100% determination c ) can be calculated as a percentage of the value divided by .

[0121] Specifically, it can be calculated according to the following calculation formula.

[0122] [Calculation formula]

[0123] Crystallinity (%) = [Energy required to melt 1g of aliphatic-aromatic polyester resin (crystal melting energy (J / g) - crystal formation energy (J / g)) / Energy required to melt 1g of aliphatic-aromatic polyester resin with 100% crystallinity (J / g)] × 100

[0124] The above aliphatic-aromatic polyester resin may have a melt index at 190° C. and 2.16 kg according to ASTM D1238 of more than 20 g / 10 min and less than 50 g / 10 min, 22 g / 10 min to 45 g / 10 min, 25 g / 10 min to 45 g / 10 min, or 25 g / 10 min to 35 g / 10 min. When the above range is satisfied, the injection processability can be improved, and the mechanical properties of the paint container being manufactured can be secured.

[0125] The content of the aliphatic-aromatic polyester resin may be 20 wt% to 50 wt%, 25 wt% to 50 wt%, 25 wt% to 45 wt%, or 30 wt% to 45 wt% based on the total weight of the biodegradable resin composition for injection. When the above range is satisfied, the injection processability can be improved, and the mechanical properties that can be imparted with functionality as a paint container can be satisfied.

[0126] The aliphatic polyester resin may have a glass transition temperature (Tg) of 50°C or higher. The glass transition temperature of the aliphatic polyester resin may be 50°C or higher, 50°C to 80°C, 50°C to 75°C, 50°C to 70°C, 55°C to 70°C, or 55°C to 65°C. When the above range is satisfied, the chain fluidity of the polymer may be reduced in the process of cooling the biodegradable resin composition for injection molding, so that the change in volume may be minimized in the process of injection molding the biodegradable resin composition for injection molding.

[0127] The content of the aliphatic polyester resin may be from more than 20 wt% to less than 40 wt%, from 25 wt% to less than 40 wt%, from 28 wt% to less than 40 wt%, or from 30 wt% to less than 40 wt%, based on the total weight of the biodegradable resin composition for injection. When the above range is satisfied, the melt index of the biodegradable resin composition for injection can be improved, so that the injection processability can be improved, and the flexural strength, flexural modulus, and brittleness can be improved.

[0128] The above aliphatic polyester resin may include polylactic acid.

[0129] The above polylactic acid may include a unit represented by the following chemical formula 1.

[0130] [Chemical Formula 1]

[0131]

[0132] The above polylactic acid may be a high-melting-point polylactic acid having a stereocomplex crystal. In addition, the polylactic acid may be formed by solution mixing or melt mixing of L-lactic acid and D-lactic acid.

[0133] The polylactic acid may be a polymer comprising L-lactic acid and / or D-lactic acid. The polylactic acid may comprise L-lactic acid and / or D-lactic acid.

[0134] Preferably, the polylactic acid comprises D-lactic acid, and the D-lactic acid may be present in an amount of 1 wt% to 5 wt%, 2 wt% to 5 wt%, 3 wt% to 5 wt%, or 4 wt% to 5 wt% based on the total weight of the polylactic acid. When the above range is satisfied, the injection processability and heat resistance properties of the paint container can be improved.

[0135] The above biodegradable resin composition for injection molding may have a different molecular weight depending on the content ratio of the aliphatic-aromatic polyester resin and the aliphatic polyester resin. In addition, the melt index of the above biodegradable resin composition for injection molding may vary depending on the molecular weight and / or the degree of bonding between the aliphatic-aromatic polyester resin and the aliphatic polyester resin.

[0136] The above aliphatic polyester resin can be modified by a surface treatment agent.

[0137] The surface of the above-mentioned aliphatic polyester resin can be modified by the above-mentioned surface treatment agent. By including the aliphatic polyester resin modified by the surface treatment agent, the biodegradable resin composition for injection can have improved compatibility with the aliphatic-aromatic polyester resin, and the bleeding phenomenon in which the aliphatic polyester resin flows out onto the surface of the paint container product can be suppressed.

[0138] The surface treatment agent may contain an amide group. The surface treatment agent may contain a fatty acid amide. The surface treatment agent containing the amide group can easily bond with the functional group of the aliphatic polyester resin, so that the surface of the aliphatic polyester resin can be more easily modified, thereby improving compatibility with the aliphatic-aromatic polyester resin and further suppressing the bleeding phenomenon.

[0139] The above surface-modified aliphatic polyester resin can be manufactured by the following method.

[0140] A surface treatment agent is added to the above aliphatic polyester resin, and the aliphatic polyester resin and the surface treatment agent are stirred so that the surface treatment agent can be bonded to the surface of the aliphatic polyester resin.

[0141] The stirring temperature may be from the melting point of the surface treatment agent to the melting point of the surface treatment agent + 50°C. The amount of the surface treatment agent added may be 0.1 parts by weight to 5 parts by weight, 0.1 parts by weight to 4 parts by weight, 0.1 parts by weight to 3 parts by weight, or 0.5 parts by weight to 3 parts by weight relative to 100 parts by weight of the aliphatic polyester resin.

[0142] The stirring time may be from about 1 minute to about 60 minutes, from about 1 minute to about 50 minutes, from about 5 minutes to about 50 minutes, or from about 5 minutes to about 40 minutes.

[0143] The biodegradable resin may further include a reinforcing material. The reinforcing material may be a fiber derived from biomass. The reinforcing material may include nanocellulose. The nanocellulose may be a natural material in the form of a gel or dry powder, and the dispersion stability, strength, and processability of the biodegradable resin including the nanocellulose may all be improved.

[0144] The diameter of the nanocellulose may be 1 nm to 100 nm, 1 nm to 95 nm, 5 nm to 90 nm, 10 nm to 80 nm, 5 nm to 60 nm, or 15 nm to 60 nm. The length of the nanocellulose may be 5 nm to 5 ㎛, 5 nm to 1 ㎛, 10 nm to 700 nm, 20 nm to 500 nm, 60 nm to 300 nm, 80 nm to 200 nm, or 100 nm to 250 nm. When the above ranges are satisfied, the strength and tear strength of the biodegradable resin composition for injection molding may be further improved.

[0145] The nanocellulose may be in the form of a dry powder or gel having aggregated secondary particles rather than single particles, and the size of the secondary particles may be 1 μm to 50 μm, 2 μm to 45 μm, or 5 μm to 50 μm. The nanocellulose may be in the form of a freeze-dried powder to reduce the volume for easy storage and transportation.

[0146] The average particle size of the above nanocellulose may be 200 nm or less, 190 nm or less, or 185 nm or less, and the particle size deviation may be 20% or less, 18% or less, or 16% or less. When the above ranges are satisfied, the dispersibility and durability of the nanocellulose may be improved.

[0147] The above nanocellulose can function as a crystal nucleating agent, thereby improving the crystallization speed of the biodegradable resin composition and increasing the crystallization temperature of the biodegradable resin composition for injection molding. The nanocellulose can be at least one selected from the group consisting of cellulose nanocrystals, cellulose nanofibers, and microfibrillated cellulose. In terms of strength and thermal properties, the nanocellulose can be preferably the cellulose nanocrystals or the cellulose nanofibers.

[0148] The above nanocellulose can perform UV resistance function, thereby providing the biodegradable resin with appropriate UV resistance properties, biodegradation rate, and hydrolysis rate. The above nanocellulose may be at least one selected from the group consisting of 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.

[0149] The above nanocellulose may be bead mill pretreated or ultrasonically pretreated. The above nanocellulose may be water-dispersed nanocellulose that has been bead mill pretreated or ultrasonically pretreated.

[0150] The above nanocellulose may be obtained by dispersing cellulose nanocrystals in a dry powder or gel form having a particle size of 1 μm to 50 μm in water and then pretreating them with a bead mill or ultrasonic pretreatment. If the above nanocellulose dispersed in water is pretreated with a bead mill or ultrasonic pretreatment, the number of nanocellulose particles may increase and dispersibility may be maximized.

[0151] The above nanocellulose may be pretreated with a silane coupling agent in an amount of 0.01 to 10 wt%, 0.05 to 8 wt%, 0.1 to 8 wt%, 0.5 to 6 wt%, or 0.7 to 6 wt% based on the total weight of the nanocellulose. When the above range is satisfied, interfacial adhesion, dispersibility, and compatibility can be maximized, and thus the mechanical properties and durability of the injection-molded biodegradable resin composition containing the same can be further improved.

[0152] The biodegradable resin may contain the nanocellulose in an amount of 0.01 to 3 wt%, 0.01 to 2.5 wt%, 0.05 to 2 wt%, 0.07 to 1.8 wt%, 0.1 to 1.2 wt%, 0.1 to 1 wt%, or 0.15 to 0.7 wt% based on the total weight of the biodegradable resin. When the above range is satisfied, the biodegradability and mechanical strength of the biodegradable resin composition for injection molding can be further improved.

[0153] The biodegradable resin composition for injection according to the present invention comprises an inorganic filler including calcium carbonate.

[0154] The above-mentioned inorganic filler can be used as a support for the aliphatic-aromatic polyester resin, the aliphatic polyester resin, or the aliphatic-aromatic polyester resin and the aliphatic polyester resin included in the above-mentioned biodegradable resin composition for injection, so that dimensional stability in the injection process can be improved.

[0155] The content of the inorganic filler may be from more than 20 wt % to less than 30 wt %, from 22 wt % to less than 30 wt %, from 23 wt % to less than 30 wt %, or from 23 wt % to 28 wt % based on the total weight of the biodegradable resin composition for injection. When the above range is satisfied, the flowability of the biodegradable resin can be improved without deteriorating the mechanical properties of the paint container according to the injection process, so that injection processability such as injection temperature, injection pressure, and cooling conditions can be implemented when manufacturing an injection-molded product. In addition, dimensional stability is improved, so that changes in the volume of the paint container according to changes over time after the injection process can be minimized. In addition, the gloss of the surface of the paint container can be increased, so that the appearance quality can be improved.

[0156] The above-mentioned inorganic filler may include heavy calcium carbonate having an average particle size of 0.1 μm to 5 μm, 0.1 μm to 4 μm, 0.1 μm to 3 μm, or 0.1 μm to 2 μm. The above-mentioned average particle size may be calculated from the measurement results of the specific surface area by the air permeation method using a specific surface area measuring device. The above-mentioned heavy calcium carbonate is obtained by mechanically crushing natural calcium carbonate, and may be distinguished from light calcium carbonate produced through a chemical precipitation reaction.

[0157] When the inorganic filler comprises heavy calcium carbonate having the above-described average particle size range, the dispersibility in the biodegradable resin composition for injection molding can be improved, and excessive viscosity increase of the biodegradable resin composition for injection molding can be suppressed. In addition, the tensile strength can be increased compared to light calcium carbonate, so that the mechanical properties of the biodegradable resin composition for injection molding can be improved. In addition, the inorganic filler can be suppressed from protruding or falling off onto the surface of the paint container due to the injection process, thereby damaging the surface properties and mechanical strength of the paint container. In addition, the acid component that may be generated during the biodegradation of the paint container can react with the heavy calcium carbonate to generate CO2 and H2O, so that the biodegradation rate of the paint container at the molecular level can be further improved. In addition, the heavy calcium carbonate can neutralize the acid component, thereby reducing environmental load and preventing acidification of the soil.

[0158] The specific surface area of ​​the above heavy calcium carbonate is 0.1 m 2 / g to 10.0 m 2 / g, 0.1 m 2 / g to 9.0 m 2 / g, 0.1 m 2 / g to 8.0 m 2 / g, 0.1 m 2 / g to 7.0 m 2 / g, 0.1 m 2 / g to 6.0 m2 / g, 0.1 m 2 / g to 5.0 m 2 / g, 0.1 m 2 / g to 4.0 m 2 / g, or 0.1 m 2 / g to 3.0 m 2 / g. The above specific surface area can be measured by a nitrogen gas adsorption method. When the above range is satisfied, it can be easily dispersed in a biodegradable resin, thereby promoting biodegradability.

[0159] The sphericity of the above-mentioned heavy calcium carbonate may be 0.30 to 0.95, 0.30 to 0.93, 0.30 to 0.90, 0.50 to 0.95, 0.50 to 0.93, 0.50 to 0.90, 0.60 to 0.95, 0.60 to 0.93, or 0.60 to 0.90. When the above range is satisfied, a large number of fine pores generated at the interface of the biodegradable resin and the inorganic filler may be included, thereby improving biodegradability.

[0160] The above heavy calcium carbonate may be surface-treated with an organic acid. By surface-treating the heavy calcium carbonate with the organic acid, the dispersibility within the biodegradable resin composition for injection molding may be increased, and the reactivity with the biodegradable resin may be improved. The surface treatment may be performed by a physical method such as plasma treatment or corona treatment, or a chemical method such as a silane coupling agent, a titanium coupling agent, or a surfactant. The organic acid may include a higher fatty acid, a higher fatty acid ester, a higher fatty acid amide, a higher fatty acid, and the like, and may be, for example, calcium stearate.

[0161] The above surface-treated heavy calcium carbonate can be manufactured by the following method.

[0162] First, calcium carbonate powder can be produced through a grinding process. Thereafter, the calcium carbonate powder can be classified to obtain calcium carbonate having a desired particle size.

[0163] Thereafter, the calcium carbonate can be heat treated at about 200°C to about 800°C by a heating device selected from a kiln, an electric furnace, or a microwave. The heat treatment time can be about 5 minutes to about 30 minutes, about 7 minutes to about 15 minutes, or about 7 minutes to about 14 minutes. The heat treatment temperature can be about 250°C to about 700°C or about 300°C to about 600°C. By heat treating the calcium carbonate under the above conditions, moisture within the calcium carbonate can be easily removed, the organic acid can be easily bound to the surface of the calcium carbonate, and agglomeration of the calcium carbonate can be minimized.

[0164] Thereafter, an organic acid may be added to the heat-treated calcium carbonate to perform a process of treating the surface of the calcium carbonate. The process temperature may be 70°C to about 130°C. The amount of the organic acid added may be about 0.5 parts by weight to about 5 parts by weight, about 0.5 parts by weight to about 4 parts by weight, about 0.5 parts by weight to about 3 parts by weight, about 0.5 parts by weight to about 2 parts by weight, about 0.6 parts by weight to about 5 parts by weight, about 0.6 parts by weight to about 4 parts by weight, about 0.6 parts by weight to about 3 parts by weight, about 0.6 parts by weight to about 2 parts by weight, about 0.7 parts by weight to about 5 parts by weight, about 0.7 parts by weight to about 4 parts by weight, about 0.7 parts by weight to about 3 parts by weight, or about 0.7 parts by weight to about 2 parts by weight, based on 100 parts by weight of the calcium carbonate. The process time may be from about 1 minute to about 60 minutes, from about 10 minutes to about 30 minutes, or from about 5 minutes to about 20 minutes.

[0165] Thereafter, the surface-treated calcium carbonate may undergo an additional process of crushing and classifying the aggregates aggregated in the surface treatment process. In the surface-treated calcium carbonate, the content of the organic acid may be about 0.1 wt% to about 3 wt%, about 0.1 wt% to about 2 wt%, about 0.1 wt% to about 1 wt%, about 0.2 wt% to about 3 wt%, about 0.2 wt% to about 2 wt%, about 0.2 wt% to about 1 wt%, about 0.3 wt% to about 3 wt%, about 0.3 wt% to about 2 wt%, or about 0.3 wt% to about 1 wt%, based on the total weight.

[0166] The above-mentioned calcium carbonate surface-treated with an organic acid may be partially oxidized. The above-mentioned surface-treated calcium carbonate may partially include calcium oxide (CaO). The proportion of the calcium oxide may be 5% by volume or less, 4% by volume or less, 3% by volume or less, 2% by volume or less, 1% by volume or less, 0.01% by volume or more to 5% by volume or less, 0.01% by volume or more to 4% by volume or less, 0.01% by volume or more to 3% by volume or less, 0.01% by volume or more to 2% by volume or less, or 0.01% by volume or more to 1% by volume, based on 100% by volume of the surface-treated calcium carbonate particles. The proportion of the calcium oxide may be measured by the EDTA (Ethylene diamine tetra acetic acid) titration method according to JIS R 9011. When the above range is satisfied, the uniformity of the surface of the calcium carbonate can be improved, and the phenomenon of organic acid being eluted from the surface of the calcium carbonate can be minimized, so that the water resistance can be improved.

[0167] The biodegradable resin composition for injection according to the present invention includes a heat stabilizer.

[0168] Previously, there were problems such as color changes or significant weight changes due to deterioration of biodegradable resins under high-temperature conditions during the injection process. Furthermore, there was a problem that the fluidity of biodegradable resins decreased under high-temperature conditions, thereby reducing the injection processability. The present inventors confirmed that when a heat stabilizer is included in a biodegradable resin composition for injection, high-temperature stability is improved, thereby improving the fluidity of the biodegradable resin, and color is maintained stably and weight changes are minimized without being affected by the residence time of the biodegradable resin during the injection process.

[0169] The above heat stabilizer may be selected from the group consisting of metal salt stabilizers, organotin stabilizers, phosphate esters, phenolic antioxidants, phosphoric stabilizers, polymeric stabilizers, and basic magnesium oxide.

[0170] Preferably, the heat stabilizer may include the phosphoric acid ester system.

[0171] The above-mentioned phosphoric acid ester system has excellent thermal stability, so that discoloration of biodegradable resins can be minimized at high temperatures. In addition, it has excellent compatibility with the above-mentioned biodegradable resins, does not easily evaporate under high-temperature conditions, is environmentally friendly, and can have improved plasticization properties. Specifically, the above-mentioned phosphoric acid ester system may be phosphoric acid octadecyl ester.

[0172] The content of the heat stabilizer may be 0.1 wt % to 3 wt %, 0.1 wt % to 2 wt %, 0.1 wt % to 1 wt %, or 0.1 wt % to 0.5 wt % based on the total weight of the biodegradable resin composition for injection. When the above range is satisfied, deterioration of the biodegradable resin under high temperature conditions can be controlled, so that the color can be stably maintained and weight change can be minimized.

[0173] The biodegradable resin composition for injection according to the present invention includes a plasticizer and has a melt index of more than 24 g / 10 min at 190°C and 2.16 kg according to ASTM D1238.

[0174] The biodegradable resin composition for injection molding contains a plasticizer, and the melt index is adjusted within the above range, so that the mechanical properties of the paint container are not deteriorated according to the injection process, and impurities such as gas within the mold are smoothly discharged during the injection process, thereby improving the stability of the injection process.

[0175] The plasticizer may be glycerol, acrylate, glycerin, glycerol monostearate (GMS), sorbitol or a mixture thereof.

[0176] The plasticizer may include polyethylene glycol having a number average molecular weight of 5,000 g / mol to 10,000 g / mol in terms of compatibility with the biodegradable resin and viscosity control of the biodegradable resin for injection.

[0177] The content of the plasticizer may be from more than 0 wt % to less than 2 wt %, from 0.1 wt % to less than 2 wt %, from 0.5 wt % to less than 2 wt %, or from 0.8 wt % to less than 2 wt %, based on the total weight of the biodegradable resin composition for injection. When the above range is satisfied, the mechanical properties of the paint container according to the injection process are not deteriorated, and the stability of the injection process can be improved.

[0178] The above biodegradable resin composition for injection molding may have a melt index at 190° C. and 2.16 kg of more than 24 g / 10 min, more than 25 g / 10 min, more than 28 g / 10 min, or more than 24 g / 10 min and less than 40 g / 10 min according to ASTM D1238. The melt index may be adjusted depending on the content of the aliphatic-aromatic polyester resin, the melt index of the aliphatic-aromatic polyester resin, the content of the aliphatic polyester resin, the melt index of the aliphatic polyester resin, the content of the inorganic filler, the content of the plasticizer, and / or the content of the heat stabilizer. When the above ranges are satisfied, the mechanical properties and injection molding processability of the paint container to be manufactured may be improved.

[0179] The above biodegradable resin composition for injection may include an antioxidant. The antioxidant may include at least one selected from the group consisting of a phosphorus-based antioxidant, a phenol-based antioxidant, and a pentaerythritol-based antioxidant.

[0180] The above phenolic antioxidants are α-tocopherol, butylhydroxytoluene, sinapyl alcohol, vitamin E, n-octadecyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate, 2-t-butyl-6-(3'-t-butyl-5'-methyl-2'-hydroxybenzyl)-4-methylphenyl acrylate, 2,6-di-t-butyl-4-(N,N-dimethylaminomethyl)phenol, 3,5-di-t-butyl-4-hydroxybenzyl phosphonate diethyl ester, 2,2-bis(((3-(3,5-di-tert-butyl-4-hydroxyphenyl)propanoyl)oxy)methyl)propane-1,3-diyl It may be at least one selected from the group consisting of bis(3-(3,5-di-tert)-butyl-4-hydroxyphenyl)propanoate), pentaerythritol tetrakis(3,5-di-tert-butyl-4-hydroxyhydrocinnamate), pentaerythritol tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], and tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyloxymethyl]methane.

[0181] The above antioxidant may further include at least one selected from the group consisting of BHT, ascorbic acid, catechin, quercetin, dodecyl gallate, TBHQ, Ralox, Irganox 1135, Irganox 1076, nordihydroguaiaretic acid, epicatechin gallate, epigallocatechin gallate, epigallocatein, propyl gallate, 2,3,5-trihydroxybutyrophenone, butylated hydroxyanisole, 4-hydroxymethyl-2,6-di-tert-butylphenol, α-tocopherol, resveratrol, rutin, astaxanthin, lycopene, beta-carotene, and melatonin.

[0182] Preferably, the biodegradable resin composition for injection molding may include a phosphate ester-based antioxidant. The phosphate ester-based antioxidant has excellent high-temperature stability and superior radical scavenging and peroxide decomposition performance, thereby improving the heat stability, color stability, and long-term storage stability of paint containers manufactured by the injection molding process.

[0183] The content of the antioxidant may be 5 wt% or less, 4 wt% or less, 3 wt% or less, 2 wt% or less, 1.5 wt% or less, 1 wt% or less, 0.5 wt% or less, 0.3 wt% or less, more than 0 wt% to 5 wt%, 0.01 wt% to 4 wt%, 0.1 wt% to 3 wt%, 1 wt% to 3 wt%, 1 wt% to 2 wt%, 0.01 wt% to 0.3 wt%, 0.05 wt% to 0.3 wt%, 0.15 wt% to 0.3 wt%, or 0.2 wt% to 0.3 wt%, based on the total weight of the biodegradable resin composition for injection.

[0184] The above biodegradable resin composition for injection may further include an activator.

[0185] The above-mentioned lubricant may include at least one selected from the group consisting of a fatty acid-based lubricant including stearic acid, an aliphatic alcohol-based lubricant, an aliphatic amide-based lubricant including stearamide, an aliphatic ester-based lubricant such as n-butyl stearate, methyl hydroxystearate, a polyhydric alcohol fatty acid ester, a saturated fatty acid ester, an ester-based wax, and a fatty acid metal soap-based lubricant. Specifically, the above-mentioned lubricant may be a stearate-based lubricant.

[0186] Preferably, the biodegradable resin composition for injection molding may further comprise a calcium-containing lubricant. Specifically, the lubricant may be calcium stearate. The calcium stearate-based lubricant has the same calcium component as the calcium carbonate, thereby exhibiting excellent compatibility, reducing heat generation due to friction during raw material mixing, melting, and processing, exhibiting an excellent dispersion effect for the biodegradable resin relative to its price, and having an excellent lubricating effect, thereby improving manufacturing efficiency.

[0187] More preferably, the biodegradable resin composition for injection molding may further include a calcium-containing lubricant and a stearyl stearate-based lubricant. The weight ratio of the calcium-containing lubricant: the stearyl stearate-based lubricant may be 1:3 to 3:1, 1:2.5 to 2.5:1, 1:2 to 2:1, or 1:1.5 to 1.5:1. When the above range is satisfied, the compatibility between the calcium-containing lubricant and the calcium carbonate is improved, and due to the excellent lubricity of the stearyl stearate-based lubricant, friction is minimized in the injection molding process, and the production speed of the paint container according to the injection molding process can be improved.

[0188] The content of the above-mentioned active agent may be 0.1 wt % to 5 wt %, 0.1 wt % to 4 wt %, 0.1 wt % to 3 wt %, or 0.1 wt % to 2 wt % based on the total weight of the biodegradable resin composition. When the above range is satisfied, the manufacturing efficiency can be improved without deteriorating the mechanical properties of the biodegradable resin composition for injection.

[0189] The above biodegradable resin composition for injection molding may include a flame retardant. The flame retardant may include at least one selected from the group consisting of halogen-based flame retardants, phosphorus-based flame retardants, and non-phosphorus halogen-based flame retardants such as metal hydrates.

[0190] The above halogen-based flame retardant may include at least one selected from the group consisting of halogenated bisphenol-based compounds such as halogenated bisphenyl alkanes, halogenated bisphenyl ethers, halogenated bisphenyl thioethers, and halogenated bisphenyl sulfones, and bisphenol-bis(alkylether)-based compounds such as brominated bisphenol A, brominated bisphenol S, chlorinated bisphenol A, and chlorinated bisphenol S.

[0191] The above-mentioned phosphorus flame retardant may include at least one selected from the group consisting of tris(diethyl phosphinic acid)aluminum, bisphenol A bis(diphenyl phosphate), triaryl isopropyl phosphate, cresyl di-2,6-xylenyl phosphate, and aromatic condensed phosphate esters.

[0192] The metal hydrate may include aluminum trihydrate, magnesium dihydrate, or a combination thereof.

[0193] The above flame retardant may include at least one selected from the group consisting of antimony oxide, such as antimony trioxide or antimony pentoxide, zinc oxide, iron oxide, aluminum oxide, molybdenum oxide, titanium oxide, calcium oxide, and magnesium oxide, as a flame retardant additive to improve the flame retardant effect.

[0194] The biodegradable resin composition for injection molding may include a dispersant. The dispersant may improve the dispersibility of solvents and solutes. The dispersant may include at least one selected from the group consisting of aliphatic polyester, polylactic acid, polyglycolic acid, polycaprolactone, and polyhydroxyalkanoate.

[0195] The dispersant may be included in an amount of 1 to 20 wt%, 1 to 15 wt%, 1 to 13 wt%, 1 to 11 wt%, 2 to 10 wt%, 5 to 15 wt%, 7 to 12 wt%, 2 to 8 wt%, 5 to 8 wt%, or 2 to 5 wt% based on the total weight of the biodegradable resin composition for injection.

[0196] The above biodegradable resin composition for injection molding may include a chain extender. The chain extender may include at least one selected from the group consisting of aromatic diisocyanates, aliphatic diisocyanates, isocyanurates, bisoxazolines, carboxylic anhydrides, and epoxides.

[0197] The above aromatic diisocyanate may include at least one selected from the group consisting of tolylene 2,4-diisocyanate, tolylene 2,6-diisocyanate, 2,2'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, 4,4'-diphenylmethane diisocyanate, naphthylene 1,5-diisocyanate, and xylylene diisocyanate.

[0198] The above aliphatic diisocyanate may include at least one selected from the group consisting of 1,6-hexamethylene diisocyanate, isophorone diisocyanate, and methylenebis(4-isocyanatocyclohexane).

[0199] The above isocyanurate may include isophorone diisocyanate or methylenebis(4-isocyanatocyclohexane).

[0200] The above bisoxazoline may include at least one selected from the group consisting of 2,2'-bis(2-oxazoline), bis(2-oxazolinyl)methane, 1,2-bis(2-oxazolinyl)ethane, 1,3-bis(2-oxazolinyl)propane, and 1,4-bis(2-oxazolinyl)butane.

[0201] The above epoxide means an epoxy-containing copolymer based on at least one of styrene, acrylic acid ester and methacrylic acid ester, and a copolymer having a copolymer content of more than 20, more than 30, or more than 50 wt% having glycidyl (meth)acrylate is preferred.

[0202] The chain extender may be 1.5 wt% or less, 1.4 wt% or less, 1.3 wt% or less, 1.2 wt% or less, 1.1 wt% or less, 1 wt% or less, 0.9 wt% or less, 0.8 wt% or less, 0.7 wt% or less, 0.6 wt% or less, 0.5 wt% or less, 0.4 wt% or less, 0.3 wt% or less, based on the total weight of the biodegradable resin composition for injection, and may be 0 wt% to 1.5 wt%, 0.01 wt% to 1.5 wt%, 0.1 wt% to 1.5 wt%, 0.1 wt% to 1.0 wt%, 0.1 wt% to 0.9 wt%, 0.1 wt% to 0.8 wt%, 0.1 wt% to 0.7 wt%, 0.1 wt% to 0.6 wt%, or 0.1 wt% to It can be 0.5 wt%.

[0203] The biodegradable resin composition for injection molding may include a hydrolysis inhibitor. When the weight average molecular weight (Mw) of the hydrolysis inhibitor is large, volatility may be low and hydrolysis resistance may be improved. When the weight average molecular weight (Mw) of the hydrolysis inhibitor is small, compatibility with the biodegradable resin may be increased.

[0204] The above hydrolysis inhibitor may be two types of hydrolysis inhibitors having different weight average molecular weights. In order to increase compatibility with a biodegradable resin, one type of hydrolysis inhibitor having a weight average molecular weight (Mw) of 10,000 g / mol or less, 9,000 g / mol or less, 8,000 g / mol or less, 7,000 g / mol or less, 6,000 g / mol or less, or 5,000 g / mol or less may be used, and in order to lower volatility and improve hydrolysis resistance, one type of hydrolysis inhibitor having a weight average molecular weight of 10,000 g / mol or more, 20,000 g / mol or more, 30,000 g / mol or more, 40,000 g / mol or more, or 50,000 g / mol or more may be used. The above weight average molecular weight can be measured as a relative value to a standard PS (standard polystyrene) sample through GPC using THF as an eluent. When the above range is satisfied, the mechanical properties and water resistance of the biodegradable resin composition for injection can be improved.

[0205] The above hydrolysis inhibitor may include a carbodiimide-based compound. The carbodiimide-based compound may react with moisture and acid to convert into a urea structure, thereby reducing the reactivity between moisture and acid and the ester group contained in the biodegradable resin. As a result, the phenomenon of the biodegradable resin being hydrolyzed by moisture and acid may be reduced, and consequently, the hydrolysis resistance of the biodegradable resin composition for injection molding may be improved.

[0206] The above carbodiimide compound may include a compound represented by the following chemical formula 2.

[0207] [Chemical Formula 2]

[0208]

[0209] In the above chemical formula 2, n is an integer from 1 to 20.

[0210] The above carbodiimide compounds are N,N'-di-o-tolylcarbodiimide, N,N'-diphenylcarbodiimide, N,N'-dioctyldecylcarbodiimide, N,N'-di-2,6-diketylphenylcarbodiimide, N-tolyl-N'cyclohexylcarbodiimide, N,N'-di-2,6-diisopropylphenylcarbodiimide, N,N'-di-2,6-di-tert-butylphenylcarbodiimide, N-tolyl-N'-phenylcarbodiimide, N,N'-di-p-nitrophenylcarbodiimide, N,N'-di-p-aminophenylcarbodiimide, N,N'-di-p-hydroxyphenylcarbodiimide, N,N'-di-cyclohexylcarbodiimide, It may be at least one selected from the group consisting of N,N'-di-p-tolylcarbodiimide, p-phenylene-bis-di-o-tolylcarbodiimide, p-phenylene-bisdicyclohexylcarbodiimide, hexamethylene-bisdicyclohexylcarbodiimide, ethylene-bisdiphenylcarbodiimide, and copolymers of benzene-2,4-diisocyanato-1,3,5-tris(1-methylethyl) homopolymer, 2,4-diisocyanato-1,3,5-tris(1-methylethyl) and 2,6-diisopropyl diisocyanate.

[0211] The weight average molecular weight (Mw) of the above carbodiimide compound may be 500 g / mol to 100,000 g / mol, 600 g / mol to 100,000 g / mol, 700 g / mol to 100,000 g / mol, 800 g / mol to 90,000 g / mol, 900 g / mol to 80,000 g / mol, 1,000 g / mol to 70,000 g / mol, 1,000 g / mol to 60,000 g / mol, or 1,000 g / mol to 50,000 g / mol.

[0212] In the above carbodiimide-based compound, the content of the NCN group may be 1 wt% to 20 wt%, 1 wt% to 19 wt%, 1 wt% to 18 wt%, 1 wt% to 17 wt%, 1 wt% to 16 wt%, 1 wt% to 15 wt%, 2 wt% to 15 wt%, 3 wt% to 15 wt%, 4 wt% to 15 wt%, 5 wt% to 15 wt%, or 6 wt% to 15 wt%. The content of the NCN group in the carbodiimide-based compound can be measured by titration with oxalic acid. When the above range is satisfied, compatibility with a biodegradable resin is not reduced, and the water resistance of the biodegradable resin composition for injection molding can be improved.

[0213] The content of the hydrolysis inhibitor may be 0.1 wt% to 5.0 wt%, 0.1 wt% to 4.0 wt%, 0.1 wt% to 3.0 wt%, 0.1 wt% to 2.0 wt%, 0.1 wt% to 1.5 wt%, or 0.1 wt% to 1.0 wt% based on the total weight of the biodegradable resin composition for injection molding. When the above range is satisfied, the water resistance and odor reduction effect of the biodegradable resin composition for injection molding can be improved.

[0214] The biodegradable resin composition for injection molding may contain a compound containing a urea group in an amount of 0.01 wt% to 10.00 wt%, 0.01 wt% to 9.00 wt%, 0.01 wt% to 8.00 wt%, 0.01 wt% to 7.00 wt%, 0.01 wt% to 6.00 wt%, 0.01 wt% to 5.00 wt%, 0.01 wt% to 4.00 wt%, or 0.01 wt% to 3.00 wt%, based on the total weight of the biodegradable resin composition for injection molding. When the above range is satisfied, the proportion of the ester group contained in the biodegradable resin that can react with moisture or acid is reduced, so that water resistance can be improved.

[0215] The biodegradable resin composition for injection molding may have a weight change rate at 200°C of less than 1.8%, less than 1%, less than 0.8%, or 0.1% to 0.7% relative to the initial weight as determined by thermogravimetric analysis (TGA). The weight change rate may be a change rate of a weight reduction relative to the initial weight as determined by TGA under isothermal conditions for 60 minutes.

[0216] A paint container according to the present invention comprises an injection-molded biodegradable resin composition comprising an aliphatic-aromatic polyester resin and a biodegradable resin including an aliphatic polyester resin, an inorganic filler including calcium carbonate, a plasticizer, and a heat stabilizer, wherein the injection-molded biodegradable resin composition has a melt index of more than 24 g / 10 min at 190° C. and 2.16 kg according to ASTM D1238.

[0217] The biodegradable resin composition for injection molding may be the same as the biodegradable resin composition for injection molding described above.

[0218] The paint container may have an Izod impact strength of more than 8 kgf·cm / cm and less than 30 kgf·cm / cm, more than 8 kgf·cm / cm and 25 kgf·cm / cm, more than 8 kgf·cm / cm and 22 kgf·cm / cm, or 10 kgf·cm / cm and 20 kgf·cm / cm, according to ASTM D256.

[0219] The above paint container has a tensile strength of 200 kgf / cm according to ASTM D638. 2 Exceeding 250 kgf / cm 2 Less than 205 kgf / cm 2 Up to 250 kgf / cm 2 Less than 210 kgf / cm 2 Up to 250 kgf / cm 2 less than or equal to 215 kgf / cm 2 Exceeding 240 kgf / cm2 It could be.

[0220] The paint container may have an elongation of 20% to 100%, 40% to 90%, 40% to 80%, or 40% to 60% as determined by ASTM D638.

[0221] When the above range is satisfied, it can have mechanical strength that can be given functionality as a paint container.

[0222] The above paint container has a flexural strength of 220 kgf / cm according to ASTM D790. 2 Exceeding 350 kgf / cm 2 Less than 250 kgf / cm 2 Up to 350 kgf / cm 2 Less than 260 kgf / cm 2 Up to 350 kgf / cm 2 Less than or equal to 270 kgf / cm 2 Up to 330 kgf / cm 2 It could be.

[0223] The above paint container has a flexural modulus of 9,100 kgf / cm according to ASTM D790. 2 Exceeding 12,000 kgf / cm 2 Less than 9,500 kgf / cm 2 Up to 12,000 kgf / cm 2 Less than 10,000 kgf / cm 2 Up to 12,000 kgf / cm 2 Less than or equal to 10,500 kgf / cm 2 Up to 11,000 kgf / cm 2 It could be.

[0224] When the above range is satisfied, it can have strength and elasticity to provide injection processability and functionality as a paint container.

[0225] The above paint container has a specific gravity of 1.3 g / cm3 1.6 g / cm 3 , 1.35 g / cm 3 1.6 g / cm 3 , 1.38 g / cm 3 1.6 g / cm 3 , 1.38 g / cm 3 1.55 g / cm 3 , or 1.38 g / cm 3 1.5 g / cm 3 If the above range is satisfied, it can be more suitably used in paint containers that require durability.

[0226] The paint container may have a biodegradability of 90% to 100%, 91% to 100%, 91% to 99%, or 92% to 99% according to the evaluation method below. When the above ranges are satisfied, the paint container can be easily decomposed after being discarded.

[0227] [Biodegradability Evaluation Method]

[0228] 1) A sample is prepared by crushing a biodegradable resin composition for injection.

[0229] 2) Prepare an inoculum container containing only compost (Manufacturer: Taeheung F&G, Product Name: Jisengto (Grade 1 Compost, By-product Fertilizer)). Separately, prepare a test container containing a 6:1 weight ratio of compost to sample, based on the dry weight of the compost.

[0230] 3) The above inoculum container and test container are cultured for 180 days under conditions of temperature 58±2℃, pH 8±1, moisture content 50%, and oxygen concentration 6% or higher.

[0231] 4) After capturing the CO2 generated from each container, measure the amount of CO2 generated from each container by titration with an aqueous phenolphthalein solution. The biodegradability of the reference (cellulose), which serves as the basis for evaluating biodegradability, is calculated according to the following formula. The biodegradability of the above samples is calculated according to the following formula, and then calculated as a relative biodegradability value based on the biodegradability of 100% of the above reference.

[0232] [ceremony]

[0233] Biodegradability (%) = [(CO2 generation in test vessel) - (CO2 generation in inoculation vessel)] / (theoretical CO2 generation in test vessel) × 100

[0234]

[0235] 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.

[0236]

[0237] Example

[0238] - Aliphatic-aromatic polyester resin: PBAT (SK Livio, MI 30 g / 10 min (190℃, 2.16kg))

[0239] - Aliphatic polyester resin #1: PLA (Nature Works 3251D, MI 30 g / 10min (190℃, 2.16kg))

[0240] - Aliphatic polyester resin #2: PLA (Kingfa, MI 55 g / 10min (190℃, 2.16kg))

[0241] - Inorganic filler: Calcium carbonate (AMC, NSS-500C)

[0242] - Plasticizer: Hanong Chemical Co., Ltd., PEG-6000

[0243] - Heat stabilizer: Adeka, AX-71

[0244] - Active ingredient #1: Calcium stearate

[0245] - Active ingredient #2: Stearyl stearate

[0246] - Antioxidant #1: Phenolic antioxidant (Adeka, AO-80)

[0247] - Antioxidant #2: Phosphate ester antioxidant (Adeka, PEP-36)

[0248]

[0249] Example 1

[0250] A resin composition containing 37.4 wt% of aliphatic-aromatic polyester resin, 35 wt% of aliphatic polyester resin #1, 25 wt% of inorganic filler, 1 wt% of plasticizer, 0.3 wt% of heat stabilizer, 0.5 wt% of lubricant #1, 0.5 wt% of lubricant #2, 0.15 wt% of antioxidant #1, and 0.15 wt% of antioxidant #2 was kneaded at a temperature of 175°C, and the kneaded product was extruded for about 3 minutes by an extruder equipped with a twin-screw.

[0251] Thereafter, the extruded resin composition was cut and cooled using a hot-cut pellet cutter to produce a pelletized resin composition.

[0252]

[0253] Examples 2 to 4 and Comparative Examples 1 to 3

[0254] A resin composition was prepared by the same process as Example 1, except that the composition and contents described in Table 1 below were applied.

[0255]

[0256] ClassificationExample 1Example 2Example 3Example 4Comparative Example 1Comparative Example 2Comparative Example 3Aliphatic-aromatic polyester resin37.4 wt%37.4 wt%37.6 wt%37.4 wt%37.7 wt%40.7 wt%36.7 wt%Aliphatic polyester resin #135 wt%-35 wt%-35 wt%38 wt%35 wt%Aliphatic polyester resin #2-35 wt%-35 wt%--Inorganic filler25 wt%25 wt%25 wt%25 wt%25 wt%20 wt%25 wt%Plasticizer1 wt%1 wt%0.8 wt%1.2 wt%1 wt%-2 wt%Heat stabilizer0.3 wt%0.3 wt%0.3 wt%0.3 wt%---Lubricant #10.5 wt% 0.5 wt% 0.5 wt% 0.5 wt% 0.5 wt% 0.5 wt% 0.5 wt% 0.5 wt% Lubricant #20.5 wt% 0.5 wt% 0.5 wt% 0.5 wt% 0.5 wt% 0.5 wt% 0.5 wt% Antioxidant #10.15 wt% 0.15 wt% 0.15 wt% 0.15 wt% 0.15 wt% 0.15 wt% 0.15 wt% Antioxidant #20.15 wt% 0.15 wt% 0.15 wt% 0.15 wt% 0.15 wt% 0.15 wt%

[0257]

[0258] Experimental example

[0259] Each of the pelletized resin compositions manufactured in Examples 1 to 4 and Comparative Examples 1 to 3 was used to manufacture a paint container under injection conditions of a temperature of about 190°C, an injection pressure of about 70 bar, a maximum holding pressure of about 75 bar, and cooling for about 20 seconds.

[0260]

[0261] Experimental Example 1 - Melt Index

[0262] The melt index at 190°C and 2.16 kg was measured for the resin compositions used in Examples 1 to 4 and Comparative Examples 1 to 3 according to ASTM D1238, and the results are shown in Table 2 below.

[0263]

[0264] Experimental Example 2 - Measuring b* values

[0265] For the resin compositions of Examples 1 to 4 and Comparative Examples 1 to 3, pelletized resin compositions were prepared by varying the residence time in the extrusion molding machine, and then sheet samples with an average thickness of 0.9 mm were prepared under conditions of 180°C and 20 MPa of pressure. Thereafter, five points were set among each sample, and the b* values ​​were measured using a colorimeter, and the results of the average value of the five b* values ​​are shown in Table 2 below.

[0266]

[0267] Experimental Example 3 - Thermogravimetric Analysis

[0268] For the resin compositions used in Examples 1 to 4 and Comparative Examples 1 to 3, the weight change rate at 200°C compared to the initial weight was measured for 60 minutes in an isothermal and oxygen atmosphere using a thermogravimetric analyzer, and the results are shown in Table 2 below.

[0269]

[0270] Experimental Example 4 - Specific Gravity

[0271] For the paint containers or separate samples manufactured in Examples 1 to 4 and Comparative Examples 1 to 3, the specific gravity was measured according to ASTM D792, and the results are shown in Table 2 below.

[0272]

[0273] Experimental Example 5 - Tensile strength and elongation

[0274] For the paint containers or separate samples manufactured in Examples 1 to 4 and Comparative Examples 1 to 3, tensile strength and elongation were measured according to ASTM D638, and the results are shown in Table 2 below.

[0275]

[0276] Experimental Example 6 - Flexural Strength and Flexural Modulus

[0277] For the paint containers or separate samples manufactured in Examples 1 to 4 and Comparative Examples 1 to 3, the flexural strength and flexural modulus were measured according to ASTM D790, and the results are shown in Table 2 below.

[0278]

[0279] Experimental Example 7 - Izod Impact Strength

[0280] For the paint containers or separate samples manufactured in Examples 1 to 4 and Comparative Examples 1 to 3, the Izod impact strength was measured according to ASTM D256, and the results are shown in Table 2 below.

[0281]

[0282] Experimental Example 8 - Fairness Evaluation

[0283] In the injection process of the paint containers of Examples 1 to 4 and Comparative Examples 1 to 3, the fairness was evaluated according to the following criteria, and the results are shown in Table 2 below.

[0284] - Good: Impurities are discharged from the mold during the injection process.

[0285] - Defect: Impurities are not discharged from the mold during the injection process.

[0286]

[0287] Classification Example 1 Example 2 Example 3 Example 4 Comparative Example 1 Comparative Example 2 Comparative Example 3 Melt Index 30g / 10min 28g / 10min 29g / 10min 27g / 10min 24g / 10min 21g / 10min 25g / 10min b* (no retention time) 0.06 0.05 0.07 0.06 1.04 1.44 1.05 b* (retention time 3 minutes) 0.06 0.05 0.06 0.05 1.42 1.68 1.38 b* (retention time) 10 minutes)0.020.030.030.021.431.751.42Thermogravimetric analysis0.638wt%0.616wt%0.622wt%0.645wt%1.811wt%1.915wt%1.818wt%Specific gravity1.4g / cm 3 1.42g / cm 3 1.4g / cm3 1.43g / cm 3 1.42g / cm 3 1.35g / cm 3 1.4g / cm 3 Tensile strength 224 kgf / cm 2 229kgf / cm 2 225kgf / cm 2 228kgf / cm 2 208kgf / cm 2 205kgf / cm 2 190kgf / cm 2 Elongation 40% 35% 40% 36% 40% 45% 50% Flexural strength 310 kgf / cm 2 317kgf / cm 2 305kgf / cm 2 315Kgf / cm 2 260kgf / cm 2 250kgf / cm 2 194kgf / cm 2 Flexural modulus: 10,610 kgf / cm 2 11,363 kgf / cm 2 10,625 kgf / cm 2 11,214 kgf / cm 2 9,450 kgf / cm 2 10,520 kgf / cm 2 8,423 kgf / cm 2 Izod impact strength 19kgf·cm / cm15kgf·cm / cm20kgf·cm / cm15kgf·cm / cm8kgf·cm / cm9kgf·cm / cm9kgf·cm / cmFairness evaluation Good Good Good Good Good Poor Good

[0288]

[0289] As can be confirmed in Tables 1 and 2 above, the biodegradable resin compositions for injection molding used in Examples 1 to 4 and the paint containers manufactured therefrom were confirmed to have improved injection processability compared to Comparative Examples 1 to 3, and to have minimized color and weight changes due to deterioration of the biodegradable resin. In addition, it was confirmed to have improved mechanical properties such as flexural modulus, flexural strength, tensile strength, and impact strength.

[0290]

[0291] The embodiment can be applied to a biodegradable resin composition for injection and a paint container comprising the same.

Claims

1. Biodegradable resin comprising aliphatic-aromatic polyester resin and aliphatic polyester resin; Inorganic filler containing calcium carbonate; plasticizer; and Contains heat stabilizers, A biodegradable resin composition for injection molding having a melt index of more than 24 g / 10 min at 190°C and 2.16 kg according to ASTM D1238.

2. In paragraph 1, The above aliphatic-aromatic polyester resin is a biodegradable resin composition for injection molding having a melt index at 190°C and 2.16 kg of more than 20 g / 10 min and less than 50 g / 10 min according to ASTM D1238.

3. In paragraph 1, A biodegradable resin composition for injection molding, wherein the content of the aliphatic polyester resin is more than 20% by weight and less than 40% by weight based on the total weight of the biodegradable resin composition for injection molding.

4. In paragraph 1, A biodegradable resin composition for injection molding, wherein the content of the inorganic filler is more than 20% by weight and less than 30% by weight based on the total weight of the biodegradable resin composition for injection molding.

5. In paragraph 1, A biodegradable resin composition for injection molding, wherein the content of the plasticizer is more than 0 wt % and less than 2 wt % based on the total weight of the biodegradable resin composition for injection molding.

6. In paragraph 1, The above biodegradable resin composition for injection molding comprises a phosphate ester-based antioxidant.

7. In paragraph 1, The above biodegradable resin composition for injection molding comprises an active agent including calcium.

8. In paragraph 1, The above biodegradable resin composition for injection molding is a biodegradable resin composition for injection molding having a weight change rate at 200°C of less than 1.8% compared to the initial weight according to thermogravimetric analysis (TGA).

9. Biodegradable resins including aliphatic-aromatic polyester resins and aliphatic polyester resins; Inorganic filler containing calcium carbonate; plasticizer; and Comprising a biodegradable resin composition for injection molding containing a heat stabilizer, A paint container having a melt index of more than 24 g / 10 min at 190° C. and 2.16 kg according to ASTM D1238 of the biodegradable resin composition for injection molding.

10. In paragraph 9, The above paint container is a paint container having an Izod impact strength of more than 8 kgf·cm / cm and less than 30 kgf·cm / cm according to ASTM D256.

11. In paragraph 9, The above paint container has a tensile strength of 200 kgf / cm according to ASTM D638. 2 Exceeding 250 kgf / cm 2 A paint container that is less than .

12. In paragraph 9, The above paint container has a flexural strength of 220 kgf / cm according to ASTM D790. 2 Exceeding 350 kgf / cm 2 A paint container that is less than .

13. In paragraph 9, The above paint container has a flexural modulus of 9,100 kgf / cm according to ASTM D790. 2 Exceeding 12,000 kgf / cm 2 A paint container that is less than .

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