KR102595592B1 - Biodegradable polyester resin composition, biodegradable polyester film comprising same and biodegradable mold product comprising same - Google Patents

Abstract

Examples provide a biodegradable polyester resin composition containing a polyester resin containing diol, aromatic dicarboxylic acid, and aliphatic dicarboxylic acid, and having a wet hardness reduction rate of 15% or less.

Description

Biodegradable polyester resin composition, biodegradable polyester film containing the same, and biodegradable molded article containing the same {BIODEGRADABLE POLYESTER RESIN COMPOSITION, BIODEGRADABLE POLYESTER FILM COMPRISING SAME AND BIODEGRADABLE MOLD PRODUCT COMPRISING SAME}

Examples relate to biodegradable polyester resin compositions, biodegradable polyester films, and biodegradable molded articles.

Recently, as concerns about environmental problems increase, solutions to the disposal problems of various household goods, especially disposable products, are required. Specifically, polymer materials are inexpensive and have excellent processability and other properties, so they are widely used to manufacture various products such as films, fibers, packaging materials, bottles, containers, etc. However, when the used products reach the end of their lifespan, they are harmful when incinerated. It has the disadvantage that it takes hundreds of years, depending on the type, for the material to be discharged and completely decomposed naturally.

In order to overcome these limitations of polymers, research on biodegradable polymers that decompose quickly is being actively conducted. As biodegradable polymers, polylactic acid (PLA), polybutylene adipate terephthalate (PBAT), and polybutylene succinate (PBS) are used.

Regarding such a biodegradable resin composition, it is disclosed in Korean Patent Publication No. 2012-0103158, etc.

Examples provide a biodegradable polyester resin composition that has improved moisture resistance and at the same time has a high degree of hydrolysis in water and high biodegradability when discarded, a biodegradable film containing the same, and a biodegradable molded article containing the same. I want to do it.

The biodegradable polyester resin composition according to the example includes a polyester resin containing diol, aromatic dicarboxylic acid, and aliphatic dicarboxylic acid, and has a wet hardness reduction rate of 15% or less, and the wet hardness reduction rate is as follows. It is measured by a measurement method.

[measurement method]

The biodegradable polyester resin composition is used to produce a polyester block having a thickness of 2.5 mm, the initial hardness of the polyester block and the wet hardness after the polyester block is immersed in water at 30° C. for 24 hours. is measured, and the wet hardness decline rate is the difference between the wet hardness and the initial hardness divided by the initial hardness.

In one embodiment, the initial hardness is Shore D hardness and may be 30 to 45, and the wet hardness may be Shore D hardness and may be 28 to 43.

In one embodiment, the wet hardness reduction rate may be 12% or less.

The biodegradable polyester resin composition according to one embodiment may include silicon element in an amount of about 0.1 ppm to about 1000 ppm.

In one embodiment, the water contact angle of the surface of the polyester block may be 45° to 85°.

In one embodiment, the difference between wet hardness after immersion in water at 30°C for 1 hour and wet hardness after immersion in water at 30°C for 24 hours may be 10% or less based on the initial hardness.

In one embodiment, the difference between wet hardness after immersion in water at 30°C for 24 hours and wet hardness after immersion in water at 70°C for 24 hours may be 10% or less based on the initial hardness.

The biodegradable polyester resin composition according to one embodiment may further include a metal.

In one embodiment, the metal includes an iron element, and the ratio of the iron element to the silicon element may be 0.1 to 0.7.

In the biodegradable polyester resin composition according to one embodiment, the degree of hydrolysis after 1 week is 35% to 60%, the degree of hydrolysis after 3 weeks is 85% or more, and the degree of hydrolysis after 1 week and the degree of hydrolysis after 3 weeks are Can be measured by the following measurement method.

[measurement method]

The degree of hydrolysis after 1 week is the rate of decrease in number average molecular weight of the biodegradable polyester resin composition compared to the initial stage when the biodegradable polyester resin composition is placed for 1 week under high temperature and high humidity conditions of 80° C. and 100% humidity. ,

The degree of hydrolysis after 3 weeks is the rate of decrease in number average molecular weight of the biodegradable polyester resin composition compared to the initial stage when the biodegradable polyester resin composition is placed for 3 weeks under high temperature and high humidity conditions of 80°C and 100% humidity. .

The biodegradable polyester film according to the example includes a polyester resin containing diol, aromatic dicarboxylic acid, and aliphatic dicarboxylic acid, and has a wet hardness reduction rate of 15% or less, and the wet hardness reduction rate is measured as follows. It is measured by method.

[measurement method]

The biodegradable polyester film is laminated to produce a polyester block with a thickness of 2.5 mm, and the initial hardness of the polyester block and the wet hardness after the polyester block is immersed in water at 30° C. for 24 hours are Measured, the wet hardness reduction rate is the difference between the wet hardness and the initial hardness divided by the initial hardness.

The molded article according to the example contains a polyester resin containing diol, aromatic dicarboxylic acid, and aliphatic dicarboxylic acid, and has a wet hardness reduction rate of 15% or less, and the wet hardness reduction rate is measured by the following measurement method. do.

[measurement method]

The biodegradable molded article is processed to produce a polyester block with a thickness of 2.5 mm, and the initial hardness of the polyester block and the wet hardness after the polyester block is immersed in water at 30° C. for 24 hours are measured. , the wet hardness reduction rate is the difference between the wet hardness and the initial hardness divided by the initial hardness.

In the biodegradable polyester resin composition according to the example, the wet hardness reduction rate is 15% or less. Accordingly, the biodegradable polyester resin composition according to the example may have high moisture resistance. The biodegradable polyester resin composition according to the example can maintain high mechanical properties even when exposed to water or in a high humidity environment.

Accordingly, the biodegradable polyester resin composition according to the example can reduce variation in mechanical properties when used for packaging moisture-rich foods, etc.

Additionally, the biodegradable polyester resin composition according to the example may have hydrophobic properties. Accordingly, the biodegradable polyester resin composition according to the example may absorb less moisture in the air. Accordingly, the biodegradable polyester resin composition according to the example may have improved storage stability.

The biodegradable polyester resin composition according to the example may include a silicone-based hydrolysis resistant agent. Accordingly, the biodegradable polyester resin composition according to the example may have improved hydrolysis resistance. In addition, the silicone-based hydrolysis resistant agent may function as a coupling agent to couple the polymer resin included in the condensation polymerization composition.

Accordingly, the silicone-based hydrolysis resistant agent can improve the degree of polymerization of the biodegradable polyester resin composition according to the example.

Accordingly, the biodegradable polyester resin composition according to the embodiment has improved mechanical and chemical properties during the actual use period, and can be easily biodegraded after use.

The biodegradable polyester resin composition according to the example can be efficiently applied to packaging films, etc. That is, the film made from the biodegradable polyester resin composition according to the example can be used for general purposes such as packaging. At this time, the biodegradable polyester resin composition according to the embodiment may initially have a low degree of hydrolysis, and the biodegradable polyester film may maintain mechanical and chemical properties above a certain level within a normal period of use by the user.

At the same time, because the biodegradable polyester resin composition according to the embodiment has a high biodegradability, the film manufactured by the biodegradable polyester resin composition according to the embodiment can be easily decomposed when discarded after use. there is.

Figure 1 is a schematic diagram showing an apparatus for manufacturing a polyester resin composition according to an example.
Figure 2 is a diagram showing an example of a biodegradable molded article formed by a polyester resin composition according to an example.

Hereinafter, the invention will be described in detail through implementation examples. The embodiment is not limited to the content disclosed below and may be modified into various forms as long as the gist of the invention is not changed.

In this specification, when a part “includes” a certain component, this means that it may further include other components rather than excluding other components, unless specifically stated to the contrary.

In addition, all numerical ranges representing physical property values, dimensions, etc. of components described in this specification should be understood as being modified by the term “about” in all cases unless otherwise specified.

In this specification, terms such as first, second, primary, and secondary are used to describe various components, and the components are not limited by the terms. The above terms are used only for the purpose of distinguishing one component from another.

The biodegradable polyester resin composition according to the example includes a biodegradable polyester resin. The biodegradable polyester resin composition according to the embodiment may include the biodegradable polyester resin alone or together with other resins or additives.

The biodegradable polyester resin includes diol, aromatic dicarboxylic acid, and aliphatic dicarboxylic acid. The biodegradable polyester resin includes a diol moiety, an aromatic dicarboxylic acid moiety, and an aliphatic dicarboxylic acid moiety. The diol moiety is derived from the diol, the aromatic dicarboxylic acid moiety is derived from the aromatic dicarboxylic acid, and the aliphatic dicarboxylic acid moiety is derived from the aliphatic dicarboxylic acid. The biodegradable polyester resin includes a diol component, an aromatic dicarboxylic acid component, and an aliphatic dicarboxylic acid component. Likewise, the diol component may be derived from the diol, the aromatic dicarboxylic acid component may be derived from the aromatic dicarboxylic acid, and the aliphatic dicarboxylic acid component may be derived from the aliphatic dicarboxylic acid.

In the description of the biodegradable polyester resin composition according to the embodiment, the diol residue may be expressed as diol. In the biodegradable polyester resin, the dicarboxylic acid residue may be expressed as dicarboxylic acid. Additionally, the residue can be expressed as the component.

The diol may be an aliphatic diol. The diol may be a bio-derived diol. The diol is 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, 1,9-nonanediol, 1,10-decanediol and 1,12-octadecane At least one diol may be selected from the group consisting of diols or their derivatives.

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

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

The diol may include 1,4-butanediol or a derivative thereof.

The aromatic dicarboxylic acids include phthalic acid, terephthalic acid, isophthalic acid, 1,4-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 1,8-naphthalenedicarboxylic acid, 4,4'- At least one may be selected from the group consisting of diphenyldicarboxylic acid, 4,4'-diphenyletherdicarboxylic acid, anthracenedicarboxylic acid, phenanthrenedicarboxylic acid, or derivatives thereof.

The 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 aromatic dicarboxylic acid may include terephthalic acid, dimethyl terephthalate, or derivatives thereof.

The aliphatic dicarboxylic acids include oxalic acid, malonic acid, succinic acid, maleic acid, fumaric acid, glutaric acid, adipic acid, pimelic acid, serveric acid, azelaic acid, sebacic acid, dodecanedicarboxylic acid, and 1,4-cyclohexanedidi. At least one may be selected from the group consisting of carboxylic acids or their derivatives.

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.

In the biodegradable 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 is about 1:0.9 to about 1: It could be 1.1. The molar ratio of total diol residues and total dicarboxylic acid residues may be from about 1:0.95 to about 1:1.05.

In the biodegradable polyester resin, the molar ratio of the aromatic dicarboxylic acid group and the aliphatic dicarboxylic acid residue may be about 3:7 to about 7:3. In the biodegradable polyester resin, the molar ratio of the aromatic dicarboxylic acid residue and the aliphatic dicarboxylic acid residue may be about 3.3:6.7 to about 6.7:3.3. In the biodegradable polyester resin, the molar ratio of the aromatic dicarboxylic acid residue and the aliphatic dicarboxylic acid residue may be about 4:6 to about 6:4.

In the biodegradable polyester resin, the molar ratio of the aromatic dicarboxylic acid residue and the aliphatic dicarboxylic acid residue may be about 4.2:5.8 to about 5:5.

The biodegradable polyester resin may contain a diol residue derived from 1,4-butanediol in an amount of about 90 mol% or more based on total diol. The biodegradable polyester resin may contain a diol residue derived from 1,4-butanediol in an amount of about 95 mol% or more based on total diol. The biodegradable polyester resin may contain a diol residue derived from 1,4-butanediol in an amount of about 98 mol% or more based on total diol.

The biodegradable polyester resin may include an aromatic dicarboxylic acid residue derived from terephthalic acid or dimethyl terephthalate in an amount of about 30 mol% to about 70 mol% based on the total dicarboxylic acid. The biodegradable polyester resin may include an aromatic dicarboxylic acid residue derived from terephthalic acid or dimethyl terephthalate in an amount of about 35 mol% to about 65 mol% based on the total dicarboxylic acid. The biodegradable polyester resin may include a dicarboxylic acid residue derived from terephthalic acid or dimethyl terephthalate in an amount of about 40 mol% to about 59 mol% based on the total dicarboxylic acid. The biodegradable polyester resin may include an aromatic dicarboxylic acid residue derived from terephthalic acid or dimethyl terephthalate in an amount of about 43 mol% to about 53 mol% based on the total dicarboxylic acid.

The biodegradable polyester resin may include an aliphatic dicarboxylic acid residue derived from adipic acid in an amount of about 30 mol% to about 70 mol% based on the total dicarboxylic acid. The biodegradable polyester resin may include an aliphatic dicarboxylic acid residue derived from adipic acid in an amount of about 35 mol% to about 65 mol% based on the total dicarboxylic acid. The biodegradable polyester resin may include an aliphatic dicarboxylic acid residue derived from adipic acid in an amount of about 41 mol% to about 60 mol% based on the total dicarboxylic acid. The biodegradable polyester resin may include an aliphatic dicarboxylic acid residue derived from adipic acid in an amount of about 47 mol% to about 57 mol% based on the total dicarboxylic acid.

Additionally, the biodegradable polyester resin may include a first block and a second block. The biodegradable polyester resin may have a molecular structure in which the first blocks and the second blocks are alternately bonded.

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 through an esterification reaction of the diol and the aromatic dicarboxylic acid. That is, the first block may mean the sum of repeating units of the diol and the aromatic dicarboxylic acid before being combined with the aliphatic dicarboxylic acid.

The second block may include the diol residue and the aliphatic dicarboxylic acid residue. The second block may be formed through 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 esterification of the diol and the aliphatic dicarboxylic acid. That is, the second block may mean the sum of repeating units of the diol and the aliphatic dicarboxylic acid before being combined with the aromatic dicarboxylic acid.

In the biodegradable polyester resin, the ratio (X/Y) of the number of first blocks (X) and the number of second blocks (Y) may be about 0.5 to about 1.5. In the biodegradable polyester resin, the ratio (X/Y) of the number of first blocks (X) and the number of second blocks (Y) may be about 0.6 to about 1.4. In the biodegradable polyester resin, the ratio (X/Y) of the number of first blocks (X) and the number of second blocks (Y) may be about 0.7 to about 1.3. In the biodegradable polyester resin, the ratio (X/Y) of the number of first blocks (X) and the number of second blocks (Y) may be about 0.75 to about 1.2. Additionally, in the biodegradable polyester resin, the ratio (X/Y) of the number of first blocks (X) and the number of second blocks (Y) may be 0.8 to 1. The number of first blocks may be smaller than the number of second blocks.

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

The number of first blocks may vary depending on the content of the aromatic dicarboxylic acid, the molecular weight of the biodegradable polyester resin, and the alternation ratio described later. That is, as the molar ratio of the aromatic dicarboxylic acid increases, the molecular weight of the biodegradable polyester resin increases, and the alternation ratio described later increases, the number of the first blocks may increase.

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

When the biodegradable polyester resin includes the first block and the second block within the above range, the biodegradable polyester resin composition according to the embodiment may have appropriate mechanical strength and appropriate biodegradability. In addition, when the biodegradable polyester resin includes the first block and the second block in the above range, the biodegradable polyester resin composition according to the embodiment may have improved flexibility and, at the same time, improved rigidity. there is. Accordingly, the biodegradable polyester resin composition according to the example can be easily used in injection molded products, etc. In addition, when the biodegradable polyester resin includes the first block and the second block in the above range, the biodegradable polyester resin composition according to the embodiment has appropriate durability against ultraviolet rays, etc., and at the same time has appropriate biodegradability. You can have it.

The first block may be represented by Chemical Formula 1 below.

[Formula 1]

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.

R1 may be a substituted or unsubstituted phenylene group, and R2 may be a butylene group.

The second block may be represented by Chemical Formula 2 below.

[Formula 2]

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 carbon atoms.

R3 and R4 may be butylene groups.

The biodegradable polyester resin may have a structure in which the first block and the second block are alternately combined with each other. The biodegradable polyester resin may be represented by Formula 3 below.

[Formula 3]

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 carbon atoms.

The diol moiety includes the moiety of 1,4-butanediol or a derivative thereof, the aromatic dicarboxylic acid moiety includes the moiety of terephthalic acid or a derivative thereof, and the aliphatic dicarboxylic acid moiety includes the moiety of adipic acid or a derivative thereof. It may include residues of

For example, the biodegradable polyester resin may include a first block containing a residue of 1,4-butanediol or a derivative thereof and a residue of terephthalic acid or a derivative thereof.

Alternatively, the biodegradable polyester resin may include a first block containing a residue of 1,4-butanediol or a derivative thereof and a residue of dimethyl terephthalate or a derivative thereof.

The biodegradable polyester resin may include a second block containing a residue of 1,4-butanediol or a derivative thereof and a residue of adipic acid or a derivative thereof.

Alternatively, the biodegradable polyester resin may include a second block containing a residue of 1,4-butanediol or a derivative thereof and a residue of succinic acid or a derivative thereof.

The biodegradable polyester resin according to an embodiment of the present invention includes a first block comprising residues of 1,4-butanediol or a derivative thereof and residues 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.

The first block may be represented by Formula 4 below, and the second block may be represented by Formula 5 below.

[Formula 4]

Here, m may be 1 to 20.

[Formula 5]

Here, n may be 1 to 20.

The biodegradable polyester resin may be represented by the following formula (6).

[Formula 6]

Here, m may be 1 to 20, and n may be 1 to 20.

When the first block and the second block satisfy the above configuration, it can be more advantageous to provide a biodegradable polyester sheet, film, or molded article with excellent biodegradability and water decomposability and improved physical properties.

Additionally, when the biodegradable polyester resin includes the first block and the second block within the above range, the biodegradable polyester resin composition according to the embodiment may have appropriate mechanical properties and appropriate UV resistance.

Since the first block and the second block have the above characteristics, the mechanical properties of the biodegradable polyester resin composition according to the embodiment can be improved.

Since the first block and the second block have the above characteristics, the biodegradable polyester resin composition according to the embodiment may have appropriate UV resistance properties.

Because the first block and the second block have the above characteristics, the biodegradable polyester resin composition according to the embodiment may have an appropriate biodegradation rate.

Because the first block and the second block have the above characteristics, the biodegradable polyester resin composition according to the embodiment may have an appropriate hydrolysis rate.

The biodegradable polyester resin may further include a branching agent. The branching agent may include at least one from the group consisting of a trivalent or higher alcohol, anhydride, or 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 biodegradable polyester resin.

The trihydric or higher alcohol may be selected from the group consisting of glycerol, pentaerythritol, or trimethylolpropane.

The above trivalent or higher carboxylic acids include methane tricarboxylic acid, ethanetricarboxylic acid, citric acid, and benzene-1,3,5-tricarboxylic acid. ,3,5-tricarboxylic acid) 5-sulfo-1,2,4-benzenetricarboxylic acid (5-sulfo-1,2,4-benzenetricarboxylic acid), ethane-1,1,2,2-tetracarboxylic acid Ethane-1,1,2,2-tetracarboxylic acid, propane-1,1,2,3-tetracarboxylic acid, butane-1, 2,3,4-tetracarboxylic acid (butane-1,2,3,4-tetracarboxylic acid), cyclopentane-1,2,3,4-tetracarboxylic acid (cyclopentane-1,2,3,4) -tetracarboxylic acid) or benzene-1,2,4,5-tetracarboxylic acid (benzene-1,2,4,5-tetracarboxylic acid).

The anhydrides include trimellitic anhydride, succinic anhydride, methylsuccinic anhydride, ethylsuccinic anhydride, 2,3-butanedicarboxylic acid anhydride, 2,4-pentanedicarboxylic acid anhydride, and 3,5-heptanedicarboxylic acid. It may include at least one from the group consisting of anhydride, 1,2,3,4-butanetetracarboxylic dianhydride, maleic anhydride, dodecylsuccinic anhydride, or pyromellitic anhydride.

The branching agent may be included in the biodegradable polyester resin in an amount of about 0.1 wt% to about 5 wt% based on the entire biodegradable polyester resin. The branching agent may be included in the biodegradable polyester resin in an amount of about 0.1 wt% to about 3 wt% based on the entire biodegradable polyester resin. The branching agent may be included in the biodegradable polyester resin in an amount of about 0.1 wt% to about 1 wt% based on the entire biodegradable polyester resin.

Since the biodegradable polyester resin includes the branching agent in the above range, the biodegradable polyester resin composition according to the embodiment may have appropriate mechanical properties and appropriate biodegradability.

The biodegradable polyester resin may further include polycarbonate diol. The polycarbonate diol may be included in a molecular structure bound to the biodegradable polyester resin.

The polycarbonate diol can be prepared by dehydration condensation reaction of carbonate and polyhydric alcohol. The carbonate may be at least one selected from the group consisting of dimethyl carbonate, diethyl carbonate, dibutyl carbonate, diphenyl carbonate, or ethylene carbonate. The polyhydric alcohol may be at least one selected from the group consisting of ethylene glycol, diethylene glycol, neopentyl glycol, 1,6-hexanediol, or 1,2-propanediol.

The weight average molecular weight of the polycarbonate diol may be about 500 to about 5000. The weight average molecular weight of the polycarbonate diol may be about 700 to about 4000. The weight average molecular weight of the polycarbonate diol may be about 800 to about 3500.

Additionally, the viscosity of the polycarbonate diol may be about 300 cps to about 20,000 cps. The viscosity of the polycarbonate diol may be about 400 cps to about 15,000 cps. The viscosity of the polycarbonate diol may be about 500 cps to about 14000 cps.

The OH value of the polycarbonate diol may be about 20 mgKOH/g to about 350 mgKOH/g. The OH value of the polycarbonate diol may be about 30 mgKOH/g to about 300 mgKOH/g.

The polycarbonate diol may be included in the biodegradable polyester resin in an amount of about 0.1 parts by weight to about 5 parts by weight based on 100 parts by weight of the biodegradable polyester resin. The polycarbonate diol may be included in the biodegradable polyester resin in an amount of about 0.5 parts by weight to about 3 parts by weight based on 100 parts by weight of the biodegradable polyester resin. The polycarbonate diol may be included in the biodegradable polyester resin in an amount of about 1 part by weight to about 3 parts by weight based on 100 parts by weight of the biodegradable polyester resin.

Since the polycarbonate diol has the above characteristics, the biodegradable polyester resin composition according to the embodiment may have appropriate wet hardness, appropriate mechanical properties, appropriate solvent resistance, appropriate degree of hydrolysis, and appropriate biodegradability.

The biodegradable polyester resin may further include polyether polyol. The polyether polyol may be included in a molecular structure bound to the biodegradable polyester resin.

The polyether polyol can be produced by adding propylene oxide (PO) or ethylene oxide (EO) to an initiator having two or more activated hydrogens (-OH or NH2). Examples of the polyether polyol include polypropylene glycol, polyethylene glycol, or polytetramethylene glycol.

The weight average molecular weight of the polyether polyol may be about 500 to about 5000. The weight average molecular weight of the polyether polyol may be about 700 to about 4000. The weight average molecular weight of the polyether polyol may be about 800 to about 3500.

Additionally, the viscosity of the polyether polyol may be about 300 cps to about 20,000 cps. The viscosity of the polyether polyol may be about 400 cps to about 15,000 cps. The viscosity of the polyether polyol may be about 500 cps to about 14000 cps.

The polyether polyol may be included in the biodegradable polyester resin in an amount of about 0.1 parts by weight to about 5 parts by weight based on 100 parts by weight of the biodegradable polyester resin. The polyether polyol may be included in the biodegradable polyester resin in an amount of about 0.5 parts by weight to about 3 parts by weight based on 100 parts by weight of the biodegradable polyester resin. The polyether polyol may be included in the biodegradable polyester resin in an amount of about 1 part by weight to about 3 parts by weight based on 100 parts by weight of the biodegradable polyester resin.

Since the polyether polyol has the above characteristics, the biodegradable polyester resin composition according to the embodiment may have appropriate wet hardness, appropriate mechanical properties, appropriate solvent resistance, appropriate degree of hydrolysis, and appropriate biodegradability.

The biodegradable polyester resin composition according to the embodiment may include the biodegradable resin in an amount of about 30 wt% or more based on the total weight of the composition. The biodegradable polyester resin composition according to the embodiment may include the biodegradable resin in an amount of about 50 wt% or more based on the total weight of the composition. The biodegradable polyester resin composition according to the embodiment may include the biodegradable resin in an amount of about 70 wt% or more based on the total weight of the composition. The biodegradable polyester resin composition according to the embodiment may include the biodegradable resin in an amount of about 80 wt% or more based on the total weight of the composition. The biodegradable polyester resin composition according to the embodiment may include the biodegradable resin in an amount of about 90 wt% or more based on the total weight of the composition. The biodegradable polyester resin composition according to the embodiment may include the biodegradable resin in an amount of about 95 wt% or more based on the total weight of the composition. The biodegradable polyester resin composition according to the embodiment may include the biodegradable resin in an amount of about 99 wt% or more based on the total weight of the composition. The maximum content of the biodegradable resin in the biodegradable polyester resin composition according to the embodiment may be about 100 wt% based on the total weight of the composition.

The biodegradable polyester resin composition according to the example may further include a reinforcing material. The reinforcing material can improve the mechanical properties of the biodegradable polyester resin composition according to the example and the film or molded product manufactured therefrom. In addition, the reinforcing material can control the deformation characteristics of the biodegradable polyester resin composition according to the example by ultraviolet rays. Additionally, the reinforcing material can control the hydrolysis characteristics of the biodegradable polyester resin composition according to the example. Additionally, the reinforcing material can control the biodegradability of the biodegradable polyester resin according to the embodiment.

The reinforcing material may be a fiber derived from biomass. The reinforcing material may be a fiber made of organic material. The reinforcing material may be nanocellulose.

The nanocellulose includes nanocrystalline cellulose, cellulose nanofibers, microfibrillated cellulose, hydroxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, hydroxypropylmethyl cellulose, cellulose acetate, methyl cellulose, ethyl cellulose, and propyl cellulose. , butyl cellulose, pentyl cellulose, hexyl cellulose, or cyclohexyl cellulose.

The nanocellulose may contain an ionic bonded metal. The nanocrystalline cellulose may contain elemental sodium. The nanocrystalline cellulose may contain a carboxylic acid salt. Additionally, the nanocrystalline cellulose may contain sulfate. The nanocrystalline cellulose may be cellulose hydrogen sulphate sodium salt.

The nanocellulose may be represented by Chemical Formula 7 below.

[Formula 7]

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.

The nanocellulose may have a specific surface area of about 200 m2/g to about 600 m2/g. The nanocellulose may have a specific surface area of about 250 m2/g to about 500 m2/g.

The weight average molecular weight of the nanocellulose may be about 10,000 g/mol to about 40,000 g/mol. The weight average molecular weight of the nanocrystalline cellulose may be about 11,000 g/mol to about 35,000 g/mol.

The moisture content of the nanocrystalline cellulose may be about 2wt% to about 8wt%. The water content of the nanocrystalline cellulose may be about 4wt% to about 6wt%.

The average diameter of the nanocellulose may be about 0.5 nm to about 10 nm. The average diameter of the nanocellulose may be about 1 nm to about 8 nm. The average diameter of the nanocellulose may be about 1.5 nm to about 7 nm.

The average length of the nanocellulose may be about 20 nm to about 300 nm. The average length of the nanocellulose may be about 30 nm to about 180 nm. The average length of the nanocellulose may be about 35 nm to about 150 nm.

When the diameter and length of the nanocellulose satisfies the above range, the biodegradability and physical properties of biodegradable polyester resin, or biodegradable polyester sheets, films, and molded products obtained using it, can be further improved.

The diameter and length of the nanocellulose can be measured by atomic force microscopy while dispersed in water.

The sulfur content of the nanocellulose may be about 0.1wt% to about 1.2wt% based on the entire nanocrystalline cellulose. The sulfur content of the nanocrystalline cellulose may be about 0.2wt% to about 1.1wt% based on the entire nanocellulose.

The pH of the nanocellulose may be 5 to 8. The pH of the nanocellulose may be 6 to 8.

The zeta potential of the nanocellulose may be about -25 mV to about -50 mV. The zeta potential of the nanocellulose may be about -30 mV to about -45 mV.

The nanocellulose may be included in the biodegradable polyester resin composition according to the embodiment in an amount of about 0.01 parts by weight to about 2 parts by weight based on 100 parts by weight of the biodegradable polyester resin. The nanocellulose may be included in the biodegradable polyester resin composition according to the embodiment in an amount of about 0.03 parts by weight to about 1.5 parts by weight based on 100 parts by weight of the biodegradable polyester resin. The nanocellulose may be included in the biodegradable polyester resin composition according to the embodiment in an amount of about 0.04 parts by weight to about 1.2 parts by weight based on 100 parts by weight of the biodegradable polyester resin. The nanocellulose may be included in the biodegradable polyester resin composition according to the embodiment in an amount of about 0.05 parts by weight to about 1 part by weight based on 100 parts by weight of the biodegradable polyester resin.

Because the nanocellulose has the above characteristics, it can be uniformly dispersed in the biodegradable polyester resin composition according to the embodiment.

Since the nanocellulose has the above characteristics, it can improve the mechanical properties of the biodegradable polyester resin composition according to the example.

In addition, the nanocellulose can function as a crystal nucleating agent and improve the crystallization rate of the biodegradable polyester resin composition according to the example. Accordingly, the nanocellulose can increase the crystallization temperature of the biodegradable polyester resin composition according to the example.

Since the nanocellulose has the above characteristics, the biodegradable polyester resin composition according to the embodiment may have appropriate UV resistance properties.

Since the nanocellulose has the above characteristics, the biodegradable polyester resin composition according to the embodiment can have an appropriate biodegradation rate.

Since the nanocellulose has the above characteristics, the biodegradable polyester resin composition according to the embodiment may have an appropriate hydrolysis rate.

The biodegradable polyester resin composition according to the example may include a metal salt.

The metal salt may be included in an amount of about 0.1 ppm to about 1000 ppm based on the total weight of the biodegradable polyester resin composition according to the embodiment. The metal salt may be included in an amount of about 1 ppm to about 500 ppm based on the total weight of the biodegradable polyester resin composition according to the embodiment. The metal salt may be included in an amount of about 1 ppm to about 100 ppm based on the total weight of the biodegradable polyester resin composition according to the embodiment. The metal salt may be included in an amount of about 1 ppm to about 50 ppm based on the total weight of the biodegradable polyester resin composition according to the embodiment.

The metal salt may be at least one selected from the group consisting of nitrate, sulfate, hydrochloride, or carboxylate. The metal salt may be at least one selected from the group consisting of titanium salt, silicon salt, sodium salt, calcium salt, potassium salt, magnesium salt, copper salt, iron salt, aluminum salt, or silver salt. The metal salt may be at least one selected from the group consisting of magnesium acetate, calcium acetate, potassium acetate, copper nitrate, silver nitrate, or sodium nitrate.

The metal salts include iron (Fe), magnesium (Mg), nickel (Ni), cobalt (Co), copper (Cu), palladium (Pd), zinc (Zn), vanadium (V), titanium, (Ti), and indium ( It may include one or more selected from the group consisting of In), manganese (Mn), silicon (Si), and tin (Sn).

In addition, the metal salt includes acetate, nitrate, nitride, sulfide, sulfate, sulfoxide, hydroxide, hydrate, It may be selected from the group consisting of chloride, chlorinate, and bromide.

Since the biodegradable polyester resin composition according to the embodiment includes the metal salt in the above content, the hydrolysis rate and biodegradation rate can be appropriately adjusted.

Since the biodegradable polyester resin composition according to the embodiment includes the metal salt in the above content, the hydrolysis rate and biodegradation rate can be appropriately adjusted.

The biodegradable polyester resin composition according to the example may further include a hydrolysis resistant agent.

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

The hydrolysis resistant agent may include an alkoxy silane. The hydrolysis resistant agent may include trimethoxy silane and/or triethoxy silane. The hydrolysis resistant agent may include an alkoxy silane containing an epoxy group. The hydrolysis resistant agent is 3-Glycidyloxypropyltriethoxysilane (γ-Glycidyloxypropyltriethoxysilane), 2-(3,4-epoxycyclohexyl) ethyltrimethoxysilane) , 3-Glycidoxypropyl methyldimethoxysilane, 3-Glycidoxypropyl trimethoxysilane, 3-Glycidoxypropyl methyldiethoxysilane ) or 3-Glycidoxypropyl triethoxysilane.

The hydrolysis resistant agent may be included in the biodegradable polyester resin composition according to the embodiment in an amount of about 1 ppm to about 10000 ppm. The hydrolysis resistant agent may be included in the biodegradable polyester resin composition according to the embodiment in an amount of about 1 ppm to about 1000 ppm. The hydrolysis resistant agent may be included in an amount of about 5ppm to 500ppm in the biodegradable polyester resin composition according to the example. The hydrolysis resistant agent may be included in an amount of about 10 ppm to 300 ppm in the biodegradable polyester resin composition according to the example.

The hydrolysis resistant agent may be bound to the biodegradable polyester resin. The hydrolysis-resistant agent may be chemically bonded to the biodegradable polyester resin. The hydrolysis-resistant agent may be chemically combined with the polymer contained in the biodegradable polyester resin. The hydrolysis-resistant agent can couple the polymers contained in the biodegradable polyester resin to each other.

Since the biodegradable polyester resin composition according to the embodiment contains the hydrolysis resistance agent in the above range, it may have appropriate hydrolysis resistance properties. In particular, since the biodegradable polyester resin according to the embodiment includes the hydrolysis resistance agent in the above range, it can have appropriate initial hydrolysis characteristics and improved biodegradability.

Accordingly, the biodegradable polyester resin composition according to the embodiment may contain a silicon element. The biodegradable polyester resin composition according to the embodiment may include silicon element in an amount of about 0.1 ppm to about 100 ppm. The biodegradable polyester resin composition according to the embodiment may include silicon element in an amount of about 0.1 ppm to about 50 ppm. The biodegradable polyester resin composition according to the embodiment may include silicon element in an amount of about 0.1 ppm to about 20 ppm.

Additionally, the hydrolysis resistant agent may react with terminal carboxyl groups or unreacted carboxyl groups. Accordingly, the biodegradable polyester resin composition according to the example may have a low acid value.

In addition, the hydrolysis-resistant agent couples the polymer contained in the biodegradable polyester resin, so that the biodegradable polyester resin composition according to the embodiment can increase the ratio of high molecular weight polymer. Accordingly, the mechanical properties of the biodegradable polyester resin composition according to the example may be improved.

The biodegradable polyester resin composition according to the example may further include a chain extender.

The chain extender may include isocyanate.

The chain extender may be at least one selected from the group consisting of monofunctional isocyanates or polyfunctional isocyanates.

The chain extender is tolylene 2,4-diisocyanate, tolylene 2,6-diisocyanate, diphenylmethane 4,4'-diisocyanate and 2,4'-diisocyanate, naphthalene 1,5-diisocyanate, At least one may be selected from the group consisting of xylylene diisocyanate, hexamethylene diisocyanate, pentamethylene diisocyanate, isophorone diisocyanate, and methylenebis(4-isocyanatocyclohexane).

The chain extender may include triisocyanate. The chain extender may include tri(4-isocyanatophenyl)methane.

The chain extender may include an acrylic polymer. The acrylic polymer may include an acrylic group. The acrylic group may be combined as a side chain to the main chain. The acrylic polymer may include an epoxy group. The epoxy group may be bonded to the main chain as a side chain.

The chain extender may include a styrene-based copolymer. The chain extender may include styrenic glycidyl acrylate.

The chain extender may be chemically bound to the biodegradable polyester resin. The chain extender may be chemically bonded to the polymer contained in the biodegradable polyester resin. The chain extender may be bound to the end of the polymer included in the biodegradable polyester resin. Additionally, the chain extender may be bound to the ends of the three polymers included in the biodegradable polyester resin.

The chain extender may be included in the biodegradable polyester resin composition according to the embodiment in an amount of about 0.1 wt% to about 10 wt% based on the total composition. The chain extender may be included in the biodegradable polyester resin composition according to the example in an amount of about 0.2 wt% to about 8 wt% based on the total composition. The chain extender may be included in the biodegradable polyester resin composition according to the embodiment in an amount of about 0.3 wt% to about 7 wt% based on the total composition.

When the biodegradable polyester resin composition according to the embodiment includes the chain extender in the above range, it may have appropriate hydrolysis resistance and appropriate biodegradability.

Additionally, the chain extender may react with terminal carboxyl groups or unreacted carboxyl groups. Accordingly, the biodegradable polyester resin composition according to the example may have a low acid value.

In addition, the chain extender couples the polymer contained in the biodegradable polyester resin, so that the biodegradable polyester resin composition according to the embodiment can increase the proportion of high molecular weight polymer. Accordingly, the mechanical properties of the biodegradable polyester resin composition according to the example may be improved.

The biodegradable polyester resin composition according to the example may include an oligomer. The molecular weight of the oligomer may be about 400 to about 1300.

The oligomer may be included in the biodegradable polyester resin composition according to the embodiment at about 3000 ppm to about 30000 ppm based on the total resin composition. The oligomer may be included in the biodegradable polyester resin composition according to the embodiment at about 5000 ppm to about 20000 ppm based on the total resin composition. The oligomer may be included in the biodegradable polyester resin composition according to the embodiment at about 5000 ppm to about 15000 ppm based on the total resin composition. The oligomer may be included in the biodegradable polyester resin composition according to the embodiment at about 7000 ppm to about 15000 ppm based on the total resin composition.

The oligomer may be a reaction product of at least two of the diol, the aromatic dicarboxylic acid, and the aliphatic dicarboxylic acid. The oligomer may be a reaction product of 1,4-butanediol, terephthalic acid, and adipic acid.

The oligomer may include an oligomer in which the molar ratio of the aliphatic dicarboxylic acid is higher than the molar ratio of the aromatic dicarboxylic acid. Among the oligomers, the ratio of oligomers containing relatively more aliphatic dicarboxylic acids may be higher than the ratio of oligomers containing relatively more aromatic dicarboxylic acids.

The oligomer can appropriately control the degree of hydrolysis of the biodegradable polyester resin composition according to the example. The oligomer may be a hydrolysis regulator that appropriately adjusts the degree of hydrolysis of the biodegradable polyester resin composition according to the example.

Additionally, the oligomer can appropriately control the biodegradability of the biodegradable polyester resin composition according to the example. The oligomer may be a biodegradation regulator that appropriately adjusts the biodegradability of the biodegradable polyester resin composition according to the example.

The biodegradable polyester resin composition according to the example may include a heat stabilizer. The heat stabilizer may be a phosphorus-based heat stabilizer.

The heat stabilizer includes amine-based high-temperature heat stabilizers such as tetraethylenepentamine, triethylphosphonoacetate, phosphoric acid, phosphorous acid, polyphosphric acid, trimethyl phosphate (TMP), At least one may be selected from the group consisting of triethyl phosphate, trimethyl phosphine, or triphenyl phosphine.

Additionally, the heat stabilizer may be an antioxidant that has an antioxidant function.

The content of the heat stabilizer may be about 3000 ppm or less based on the total weight of the biodegradable polyester resin. The content of the heat stabilizer may be, for example, 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 biodegradable polyester resin. When the content of the heat stabilizer satisfies the above range, the deterioration of the polymer due to high temperature during the reaction process can be controlled, the end groups of the polymer can be reduced, and the color can be improved. In addition, the heat stabilizer can control the reaction rate by suppressing the activation of titanium-based catalysts.

The biodegradable polyester resin composition according to the example may include an elongation improver. Examples of the elongation improver include oils such as paraffin oil, naphthenic oil, or aromatic oil, or adipates such as dibutyl adipate, diethylhexyl adipate, dioctyl adipate, or diisopropyl adipate.

The elongation improver may be included in the biodegradable polyester resin composition according to the embodiment in an amount of about 0.001 parts by weight to about 1 part by weight, based on 100 parts by weight of the biodegradable polyester resin. The elongation improver may be included in the biodegradable polyester resin composition according to the embodiment in an amount of about 0.01 parts by weight to about 1 part by weight, based on 100 parts by weight of the biodegradable polyester resin.

The biodegradable polyester resin composition according to the example may include an inorganic filler. The inorganic fillers include calcium sulfate, barium sulfate, talc, talcum powder, bentonite, kaolin, chalk powder, calcium carbonate, graphite, gypsum, electrically conductive carbon black, calcium chloride, iron oxide, aluminum oxide, potassium oxide, dolomite, silicon dioxide, and wollastonite. , titanium dioxide, silicate, mica, glass fiber, or mineral fiber.

For the inorganic filler, in the particle size distribution obtained by laser diffraction, the particle size (D ₅₀ ) of 50% of the cumulative volume basis is about 100 ㎛ or less, about 85 ㎛ or less, about 70 ㎛ or less, about 50 ㎛ or less, about 25 ㎛ or less. It may be ㎛ or less, about 10 ㎛ or less, about 5 ㎛ or less, about 3 ㎛ or less, or about 1 ㎛ or less.

Additionally, the specific surface area of the inorganic filler may be about 100 m ² /g or more. For example, the specific surface area of the inorganic filler may be about 100 m ² /g or more, about 105 m ² /g or more, or about 110 m ² /g or more.

The inorganic filler may be included in the biodegradable polyester resin composition according to the embodiment in an amount of about 3 parts by weight to about 50 parts by weight based on 100 parts by weight of the biodegradable polyester resin. The inorganic filler may be included in the biodegradable polyester resin composition according to the embodiment in an amount of about 5 parts by weight to about 30 parts by weight based on 100 parts by weight of the biodegradable polyester resin.

The inorganic filler may be included in an amount of about 3,000 ppm or less based on the total weight of the biodegradable polyester resin composition according to the example. For example, the content of the inorganic filler may be about 3,000 ppm or less, about 1,500 ppm or less, about 1,200 ppm or less, about 800 ppm or less, or about 600 ppm or less based on the total weight of the biodegradable polyester resin composition according to the embodiment. and may be about 50 ppm or more, about 100 ppm or more, about 130 ppm or more, about 150 ppm or more, or about 180 ppm or more.

Since the biodegradable polyester resin composition according to the embodiment includes the inorganic filler in the above content, the mechanical properties, appropriate UV resistance, appropriate biodegradation rate, and appropriate hydrolysis rate of the biodegradable polyester resin composition according to the example You can have

The biodegradable polyester resin composition according to the embodiment may further include a heterogeneous biodegradable resin. The biodegradable polyester resin composition according to the embodiment may be a composite resin composition containing two or more types of resins, fillers, and additives.

The heterogeneous biodegradable resins include polybutylene azelate terephthalate (PBAzT), polybutylene sebacate terephthalate (PBSeT), polybutylene succinate terephthalate (PBST), polyhydroxyalkanoate (PHA), or At least one may be selected from the group consisting of polylactic acid (PLA).

The heterogeneous biodegradable resin may be included in the biodegradable polyester resin composition according to the embodiment in an amount of about 10 parts by weight to about 100 parts by weight based on 100 parts by weight of the biodegradable polyester resin. The heterogeneous biodegradable resin may be included in the biodegradable polyester resin composition according to the embodiment in an amount of about 10 parts by weight to about 60 parts by weight based on 100 parts by weight of the biodegradable polyester resin. The heterogeneous biodegradable resin may be included in the biodegradable polyester resin composition according to the embodiment in an amount of about 20 parts by weight to about 50 parts by weight based on 100 parts by weight of the biodegradable polyester resin.

The heterogeneous biodegradable resin can complement the mechanical, optical and chemical properties of the biodegradable polyester polyester resin. Since the biodegradable polyester resin composition according to the embodiment includes the heterogeneous biodegradable resin in the above content, the biodegradable polyester resin composition according to the embodiment has mechanical properties, appropriate UV resistance, appropriate biodegradation rate, and appropriate It can have a hydrolysis rate.

Additionally, the number of carboxyl terminal groups in the biodegradable polyester resin composition according to the example may be about 50 eq/ton or less. For example, the number of carboxyl terminal groups of the biodegradable polyester resin according to the embodiment may be about 50 eq/ton or less, about 48 eq/ton or less, about 45 eq/ton or less, or about 42 eq/ton or less. By adjusting the number of carboxyl terminal groups within the above range, when the biodegradable polyester resin composition according to the embodiment is extruded to form a molded article, deterioration can be prevented and improved mechanical properties can be realized.

Additionally, the intrinsic viscosity (IV) of the biodegradable polyester resin composition according to the example may be about 0.9 dl/g or more. The intrinsic viscosity of the biodegradable polyester resin composition according to the embodiment may be about 0.95 dl/g or more, about 1.0 dl/g or more, about 1.1 dl/g or more, about 1.2 dl/g or more, or about 1.3 dl/g or more. . The intrinsic viscosity of the biodegradable polyester resin composition according to the example may be from about 0.95 dl/g to about 1.7 dl/g. The intrinsic viscosity of the biodegradable polyester resin composition according to the example may be about 1.3 dl/g to about 1.7 dl/g. The intrinsic viscosity of the biodegradable polyester resin composition according to the examples may be about 1.4 dl/g to about 1.7 dl/g.

The process of manufacturing the biodegradable polyester resin composition according to the example is as follows.

Referring to FIG. 1, the apparatus for producing the biodegradable polyester resin includes a slurry stirrer (100), an esterification reaction unit (200), a condensation polymerization reaction unit (300), a post-processing unit (400), and a first recovery unit (510). ) and a second recovery unit 520.

The method for producing the biodegradable polyester resin includes preparing a slurry containing the diol and the aromatic dicarboxylic acid.

Preparing the slurry includes mixing and treating the diol and the aromatic dicarboxylic acid. That is, the step of preparing the slurry is a pretreatment step before the esterification reaction, and may be a step of mixing the diol and the aromatic dicarboxylic acid and slurrying them. At this time, the diol may include a biomass-based diol component.

The temperature of the slurry of the diol and the aromatic dicarboxylic acid may be about 5°C to about 15°C higher than the melting point of the diol. For example, when the diol is 1,4-butanediol, the temperature of the slurry may be about 35°C to about 45°C.

The diol and the aromatic dicarboxylic acid are added to the slurry stirrer 100 and stirred to prepare the slurry.

By mixing and pretreating the diol and aromatic dicarboxylic acid to form a slurry, not only can the diol and aromatic dicarboxylic acid be reacted uniformly, but it is also effective in rapidly advancing the esterification reaction, thereby increasing reaction efficiency. there is.

In particular, when an aromatic dicarboxylic acid, such as terephthalic acid, has complete crystallinity and is in powder form, its solubility in the diol is very low, making it difficult for a homogeneous reaction to occur. Therefore, the slurry pretreatment process can play a very important role in providing biodegradable polyester resins, sheets, films, and molded products with excellent physical properties according to embodiments of the present invention and improving reaction efficiency.

When the aromatic dicarboxylic acid is terephthalic acid, the terephthalic acid has complete crystallinity and is a white crystal that sublimates at around 300°C at normal pressure without a melting point. Since the solubility in the diol is very low and a homogeneous reaction is difficult to occur, esterification If a pretreatment process is performed before the reaction, a uniform reaction can be induced by increasing the surface area for reaction with diol within the solid matrix of terephthalic acid.

In addition, when the aromatic dicarboxylic acid is dimethyl terephthalate, the dimethyl terephthalate can be made into a molten state at about 142°C to 170°C through the pretreatment process and reacted with the diol, making the esterification reaction faster and more efficient. You can proceed with .

Meanwhile, in the pretreatment step of preparing the slurry, the structure and physical properties of the biodegradable polyester resin may vary depending on the particle size, particle size distribution, pretreatment reaction conditions, etc. of the aromatic dicarboxylic acid.

For example, the aromatic dicarboxylic acid includes terephthalic acid, and the average particle diameter (D50) of the terephthalic acid in particle size distribution (PSD) measured by a particle size analyzer Microtrac S3500 is 10㎛ to 400㎛, and the average particle diameter (D50) The standard deviation for may be 100 or less. The standard deviation means the square root of the variance. The average particle diameter (D50) of the terephthalic acid may be, for example, 20 μm to 200 μm, for example, 30 μm to 180 μm, or for example, 100 μm to 160 μm. When the average particle diameter (D50) of terephthalic acid satisfies the above range, it can be more advantageous in terms of improved solubility in diol and reaction speed.

In the pretreatment process, the diol and the aromatic dicarboxylic acid can be mixed and introduced into the slurry stirrer 100 (tank).

The slurry agitator 100, for example, has an anchor type at the bottom, has a height of 20 mm or more to the agitator, and is provided with three or more rotary blades, which may be more advantageous in achieving an efficient stirring effect.

For example, the slurry stirrer 100 may have a height of 20 mm or more, that is, the distance between the reactor and the lowest part of the stirrer may be almost adjacent, and in this case, slurry can be obtained without precipitation. If the shape, form, and rotary blade of the stirrer do not satisfy the above conditions, the aromatic dicarboxylic acid may settle to the bottom when the diol and aromatic dicarboxylic acid are initially mixed, in which case phase separation may occur. there is.

The pretreatment process for preparing the slurry includes mixing the diol and the aromatic dicarboxylic acid and stirring at about 30° C. to about 100° C. at about 50 rpm to about 200 rpm for 10 minutes or more, such as 10 minutes to 200 minutes. can do.

The diol may have the characteristics described above.

The diol can be added all at once or in divided doses. For example, the diol can be added separately when mixed with aromatic dicarboxylic acid and when mixed with 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 about 0.8:1 to about 2:1. In the pretreatment step of preparing the slurry, the molar ratio of the diol and the aromatic dicarboxylic acid may be about 1.1:1 to about 1.5:1. In the pretreatment step of preparing the slurry, the molar ratio of the diol and the aromatic dicarboxylic acid may be about 1.2:1 to about 1.5:1.

If the diol is added in a larger amount than the aromatic dicarboxylic acid, the aromatic dicarboxylic acid can be easily dispersed.

Additionally, additives may be added to the slurry. The nanocellulose and/or the metal salt may be added to the slurry in the form of a dispersion or solution.

The method for producing the biodegradable polyester resin includes mixing diol and aromatic dicarboxylic acid and performing an esterification reaction using the slurry obtained by pretreatment to obtain a prepolymer, and subjecting the prepolymer to a condensation polymerization reaction. Embodiments of the present invention Accordingly, the structure and physical properties of the desired biodegradable polyester resin can be efficiently achieved.

The method for producing the biodegradable polyester resin includes producing a prepolymer by esterifying the slurry and the aliphatic dicarboxylic acid. The slurry and the aliphatic dicarboxylic acid may be reacted in the ester reaction unit.

In the esterification reaction, the reaction time can be shortened by using the slurry. For example, the slurry obtained in the pretreatment step can shorten the reaction time of the ester reaction by more than 1.5 times.

The esterification reaction may proceed at least twice. Through the esterification reaction, a prepolymer that is introduced into the condensation polymerization process can be formed.

In one embodiment, the esterification reaction may be performed at once after adding an aliphatic dicarboxylic acid, or a diol and an aliphatic dicarboxylic acid to the slurry. That is, the slurry is input into the esterification reactor, and the aliphatic dicarboxylic acid alone or the aliphatic dicarboxylic acid and the diol are input into the esterification reactor, and the esterification reaction can proceed.

The diol and the aliphatic dicarboxylic acid may be added to the slurry containing the aromatic dicarboxylic acid in the form of a slurry.

In the slurry of the diol and the aliphatic dicarboxylic acid, the average particle diameter (D50) of the aliphatic dicarboxylic acid may be about 50 μm to about 150 μm. In the slurry of the diol and the aliphatic dicarboxylic acid, the average particle diameter (D50) of the aliphatic dicarboxylic acid may be about 60 μm to about 120 μm.

In the esterification reaction, the total number of moles of diol added may be about 1.0 to about 1.8 compared to the total number of moles of the aromatic dicarboxylic acid and the aliphatic dicarboxylic acid. In the esterification reaction, the total number of moles of diol added may be about 1.1 to about 1.6 compared to the total number of moles of the aromatic dicarboxylic acid and the aliphatic dicarboxylic acid.

Additionally, the temperature of the slurry of the diol and the aliphatic dicarboxylic acid may be about 5°C to about 15°C higher than the melting point of the diol.

Additionally, various additives such as the nano cellulose may also be added to the slurry of the diol and the aliphatic dicarboxylic acid.

The esterification reaction may be performed at about 250°C or less for about 0.5 hours to about 5 hours. Specifically, the esterification reaction is carried out at normal 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 water as a by-product theoretically reaches 95%. It can be. For example, the esterification reaction may be performed for 0.5 hours to 5.5 hours, 0.5 hours to 4.5 hours, or 1 hour to 4 hours, but is not limited thereto.

In one embodiment, the polycarbonate diol and/or the polyether polyol may be mixed with the slurry, and a first esterification reaction may proceed. Alternatively, the polycarbonate diol and/or the polyether polyol may be added to the second esterification reaction.

Additionally, after the first ester reaction, a mixture of the aliphatic dicarboxylic acid and the diol may be added to the esterification reaction unit, and a second ester reaction may proceed together with the first ester reaction product. Additionally, the polycarbonate diol and/or the polyether polyol may be added to the second esterification reaction.

The first ester 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 or reduced pressure at 180°C to 250°C, 185°C to 240°C, or 200°C to 240°C until water as a by-product theoretically reaches 95%. For example, the first esterification reaction may be performed for 1.25 hours to 4 hours, 1.25 hours to 3.5 hours, or 2.5 hours to 3 hours, but is not limited thereto.

The second ester reaction may be performed at about 250°C or less for 0.25 to 3.5 hours. Specifically, the second esterification reaction may be performed at normal or reduced pressure at 180°C to 250°C, 185°C to 240°C, or 200°C to 240°C until water as a by-product theoretically reaches 95%. For example, the second esterification reaction may be performed for 0.5 hours to 3 hours, 1 hour to 2.5 hours, or 1.5 hours to 2.5 hours, but is not limited thereto.

In the first ester reaction and the second ester reaction, the reaction temperature, reaction time, and the contents of the diol, aromatic dicarboxylic acid, and aliphatic dicarboxylic acid added are respectively adjusted, so that the first block and the second block The number ratio, etc. can be adjusted. Additionally, when the ester reaction is divided into the first ester reaction and the second ester reaction, the entire ester reaction can be precisely controlled. Accordingly, when the ester reaction proceeds separately, the reaction stability and reaction uniformity of the ester reaction can be improved.

Additionally, in the second ester reaction, the branching agent may be additionally added. That is, the mixture of the aliphatic dicarboxylic acid, the diol, the branching agent, and the first ester reaction product may react to form the prepolymer. The characteristics and content of the branching agent may be the same as described above.

By the esterification reaction, a prepolymer can be formed.

The number average molecular weight of the prepolymer may be about 500 to about 10000 g/mol. For example, the number average molecular weight of the prepolymer is about 500 to about 8500 g/mol, about 500 to about 8000 g/mol, about 500 to about 7000 g/mol, about 500 g/mol to about 5000 g/mol, or about 800 g/mol. mol to about 4000 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.

The number average molecular weight can be measured using gel permeation chromatography (GPC). Specifically, the data produced by gel permeation chromatography includes several items such as Mn, Mw, and Mp, but the molecular weight can be measured based on the number average molecular weight (Mn).

The reinforcing material, the branching agent, the polycarbonate diol, the polyether polyol, or the metal salt may be added together with the slurry before the esterification reaction. The reinforcing material, the branching agent, the polycarbonate diol, the polyether polyol, and/or the metal salt may be added to the esterification reaction unit 200 in the middle of the esterification reaction. The reinforcing material, the branching agent, the polycarbonate diol, the polyether polyol, and/or the metal salt may be added to the ester reaction product after the esterification reaction. Additionally, the reinforcing material, the branching agent, the polycarbonate diol, the polyether polyol, and/or the metal salt may be added together with the aliphatic dicarboxylic acid. In addition, the reinforcing material, the branching agent, the polycarbonate diol, the polyether polyol, and/or the metal salt may be added to the esterification reaction unit 200 after the first ester reaction and before the second ester reaction. there is.

Since the reinforcing material and/or the metal salt are added to the esterification reaction, the reinforcing material and/or the metal salt may be uniformly dispersed in the biodegradable polyester resin.

The reinforcing material may have the characteristics described above. In particular, nanocellulose may be used as the reinforcing material.

The nanocellulose may be pretreated by a bead mill, ultrasonic waves, or high-speed dispersion at about 1000 rpm to about 1500 rpm before being added. Specifically, the nanocellulose may be water-dispersed nanocellulose that has been pretreated with a bead mill or pretreated with ultrasonic waves.

First, the bead mill pretreatment can be performed using a vertical mill or horizontal mill as a wet milling device. The horizontal mill is preferable because it allows for a larger amount of beads to be filled inside the chamber, reduces uneven wear of the machine, reduces bead wear, and makes maintenance easier, but is not limited to this.

The bead mill pretreatment may be performed using one or more beads selected from the group consisting of zirconium, zircon, zirconia, quartz, and aluminum oxide.

Specifically, the bead mill pretreatment may be performed using beads having a diameter of about 0.3 mm to about 1 mm. For example, the bead may have a diameter of about 0.3 mm to about 0.9 mm, about 0.4 mm to about 0.8 mm, about 0.45 mm to about 0.7 mm, or about 0.45 mm to about 0.6 mm.

If the diameter of the beads satisfies the above range, the dispersibility of nanocellulose can be further improved. If the diameter of the beads exceeds the above range, the average particle size and particle size deviation of nanocellulose may increase, resulting in lower dispersibility.

In addition, for the bead mill pretreatment, it is preferable to use beads with a specific gravity higher than that of nanocellulose because sufficient energy can be transferred. For example, the beads may be one or more selected from the group consisting of zirconium, zircon, zirconia, quartz, and aluminum oxide, which have a specific gravity higher than that of the water-dispersed nanocellulose, and have a specific gravity of more than 4 times that of the water-dispersed nanocellulose. High zirconium beads are preferred, but are not limited thereto.

In addition, the ultrasonic pretreatment is a method of physically breaking or pulverizing nanoparticles with waves generated by emitting 20 kHz ultrasound into a solution.

The ultrasonic pretreatment may be performed for less than 30 minutes at an output of 30,000 J/s or less. For example, the ultrasonic pretreatment may be performed for 25 minutes or less, 20 minutes or less, or 18 minutes or less at an output of 25,000 J/s or less or 22,000 J/s or less. When the output and execution time satisfy the above range, the effect of ultrasonic pretreatment, that is, the improvement in dispersibility, can be maximized. If the output exceeds the above range, the nanoparticles may re-agglomerate and the dispersibility may be lowered.

Nanocellulose according to embodiments may be bead mill pretreated or ultrasonic pretreated. Alternatively, the nanocellulose according to the embodiment may have been subjected to both bead mill pretreatment and ultrasonic pretreatment. At this time, it is preferable that ultrasonic pretreatment is performed after bead mill pretreatment in order to prevent re-agglomeration and improve dispersibility.

Nanocellulose according to embodiments may be bead mill pretreated or ultrasonic pretreated. Alternatively, the nanocellulose according to the embodiment may have been subjected to both bead mill pretreatment and ultrasonic pretreatment. At this time, it is preferable that ultrasonic pretreatment is performed after bead mill pretreatment in order to prevent re-agglomeration and improve dispersibility.

Because the nanocellulose contains ion-bonded metal, its dispersibility in water is very high. In addition, by the bead mill pretreatment and/or the ultrasonic pretreatment, an aqueous dispersion with a very high degree of dispersion of the nanocellulose can be obtained. In the nano-cellulose aqueous dispersion, the content of nano-cellulose may be about 1 wt% to about 50 wt%.

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

In addition, the titanium-based catalyst and/or the germanium-based catalyst are added to the slurry before the first esterification reaction, and the titanium-based catalyst and/or the germanium-based catalyst are further added to the product of the first esterification reaction. It can be.

The biodegradable polyester resin consists of titanium isopropoxide, antimony trioxide, dibutyltin oxide, tetrapropyl titanate, tetrabutyl titanate, tetraisopropyl titanate, antimony acetate, calcium acetate, and magnesium acetate. It may include one or more titanium-based catalysts selected from the group, or one or more germanium-based catalysts selected from the group consisting of germanium oxide, germanium methoxide, germanium ethoxide, tetramethyl germanium, tetraethyl germanium, and germanium sulfide.

Additionally, the content of the catalyst may be about 100 ppm to 2000 ppm based on the total weight of diol, aromatic dicarboxylic acid, and aliphatic dicarboxylic acid. For example, it may include about 100 ppm to about 1600 ppm, about 150 ppm to about 1400 ppm, about 200 ppm to about 1200 ppm, or about 250 ppm to about 1100 ppm of a titanium-based catalyst or a germanium-based catalyst. When the catalyst content satisfies the above range, the physical properties can be further improved.

Additionally, the heat stabilizer may be added together with the slurry before the esterification reaction. The heat stabilizer may be added to the esterification reaction unit 200 during the esterification reaction. The heat stabilizer may be added to the ester reaction product after the esterification reaction. Additionally, the heat stabilizer may be added together with the aliphatic dicarboxylic acid. Additionally, the heat stabilizer may be added to the esterification reaction unit 200 after the first ester reaction and before the second ester reaction.

The characteristics of the heat stabilizer may be the same as described above.

The content of the heat stabilizer may be 3,000 ppm or less based on the total weight of diol, aromatic dicarboxylic acid, and aliphatic dicarboxylic acid. Specifically, the content of the heat stabilizer is, for example, 10ppm to 3,000ppm, 20ppm to 2,000ppm, 20ppm to 1,500ppm, or 20ppm to 200ppm based on the total weight of diol, aromatic dicarboxylic acid, and aliphatic dicarboxylic acid. It can be. When the content of the heat stabilizer satisfies the above range, the deterioration of the polymer due to high temperature during the reaction process can be controlled, the end groups of the polymer can be reduced, and the color can be improved.

After completion of the esterification reaction, at least one selected from the group consisting of additives such as silica, potassium or magnesium, and color correctors 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 corrector is added and stabilized, and then the condensation polymerization reaction can proceed. The additive and/or the color corrector may be added after completion of the esterification reaction and introduced into the condensation polymerization reaction unit 300 together with the prepolymer. Accordingly, the additive and/or the color corrector may be uniformly dispersed in the biodegradable polyester resin.

Additionally, after completion of the esterification reaction, the inorganic filler may be added to the esterification reaction product. That is, after the esterification reaction is completed, the inorganic filler is added and stabilized, and then the condensation polymerization reaction can proceed. The characteristics of the inorganic filler are the same as described above. The inorganic filler is added to the condensation polymerization reaction unit 300 together with the prepolymer, and the condensation polymerization process may proceed. Accordingly, the inorganic filler can be uniformly dispersed in the biodegradable polyester resin.

Additionally, the first recovery unit 510 recovers reaction by-products such as water from the esterification reaction unit 200. The first recovery unit 510 may apply vacuum pressure to the esterification reaction unit 200 or perform reflux to recover by-products generated in the esterification reaction.

The method for producing the biodegradable polyester resin includes subjecting the prepolymer to a condensation polymerization reaction. The condensation polymerization reaction may proceed as follows.

The prepolymer is introduced into the condensation polymerization reaction unit 300. Additionally, at least one of the reinforcing material, the heat stabilizer, the color corrector, the inorganic filler, the metal salt, or other additives may be added to the condensation polymerization reaction unit 300 together with the prepolymer.

Thereafter, the condensation polymerization reaction may be performed 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 condensation polymerization reaction may be performed at about 190°C to about 270°C, about 210°C to about 260°C, or about 230°C to about 255°C, and at a temperature of about 0.9 torr or less, about 0.7 torr or less, or about 0.2 torr or less. It may be performed at about 10 torr to about 10 torr, about 0.2 torr to about 0.9 torr, or about 0.2 torr to about 0.6 torr, and about 1.5 hours to about 5 hours, about 2 hours to about 4.5 hours, or about 2 hours to about 4 hours. It can be performed during

Additionally, the condensation polymerization reaction may include primary condensation polymerization and secondary condensation polymerization.

For example, the primary condensation polymerization is 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, and about 1 torr to about 200 torr. torr, about 2 torr to about 100 torr, about 4 torr to about 50 torr, about 5 torr to about 45 torr, or about 8 torr to about 32 torr for about 0.5 hours to about 3.5 hours, about 0.5 hours to about 3.0 hours, or It may be performed for about 0.5 hours to about 2.8 hours.

In addition, the secondary condensation polymerization is 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 or less. torr to about 1 torr, about 0.2 torr to about 0.8 torr, or about 0.2 torr to about 0.6 torr, for about 0.5 hours to about 4 hours, about 1 hour to about 3.5 hours, or about 1.5 hours to about 3.5 hours. there is.

Additionally, a titanium-based catalyst or a germanium-based catalyst may be further added to the prepolymer before the condensation polymerization reaction. Additionally, before the condensation polymerization reaction, additives such as silica, potassium or magnesium may be added to the prepolymer; Amine-based stabilizers such as trimethyl phosphate, triphenyl phosphate, trimethyl phosphine, phosphoric acid, phosphorous acid, or tetraethylenepentamine; And one or more types selected from the group consisting of polymerization catalysts such as antimony trioxide, antimony trioxide, or tetrabutyl titanate may be additionally added.

The number average molecular weight of the polymer may be about 30000 g/mol or more. For example, the number average molecular weight of the polymer may be about 33,000 g/mol or more, about 35,000 g/mol or more, or about 40,000 g/mol to about 90,000 g/mol. When the number average molecular weight of the polymer satisfies the above range, physical properties, impact resistance, durability, and moldability can be further improved.

Additionally, the second recovery unit 520 recovers reaction by-products such as water from the condensation polymerization reaction unit 300. The second recovery unit 520 may apply vacuum pressure to the condensation polymerization reaction unit 300 and recover by-products generated in the condensation polymerization reaction.

The second recovery unit 520 may apply a vacuum pressure of about 0.1 torr to about 1 torr to the interior of the condensation polymerization reaction unit 300. The second recovery unit 520 may apply a vacuum pressure of about 0.1 torr to about 0.9 torr to the interior of the condensation polymerization reaction unit 300.

Thereafter, the hydrolysis resistant agent and/or the chain extender are added to the polymer. Thereafter, the polymer, the hydrolysis resistant agent and the chain extender are mixed uniformly and maintained at a temperature of about 200° C. to about 260° C. for about 1 minute to about 15 minutes. Accordingly, the polymer reacts with the hydrolysis resistant agent and/or the chain extender.

Alternatively, the hydrolysis resistant agent and/or the chain extender may be added to the condensation polymerization reaction unit 300 through a static mixer and reacted with the polymer. The reaction temperature of the hydrolysis resistant agent and/or the chain extender in the condensation polymerization reaction unit 300 may be about 200°C to about 260°C. Additionally, the reaction time of the hydrolysis resistant agent and/or the chain extender in the condensation reaction unit 300 may be about 1 minute to about 15 minutes.

The chain extender may have the characteristics described above.

Accordingly, the biodegradable polyester resin composition according to the example may have an appropriate degree of hydrolysis and a high degree of biodegradation.

Afterwards, pellets can be manufactured from the polymer.

Specifically, after cooling the polymer to about 15°C or lower, about 10°C or lower, or about 6°C or lower, the cooled polymer can be cut to produce pellets. Alternatively, the polymer can be cut at temperatures ranging from about 40°C to about 60°C.

The cutting step can be performed without limitation using any pellet cutting machine used in the industry, and the pellets can have various shapes. The pellet cutting method may include an underwater cutting method or a strand cutting method.

The pellets may undergo additional post-processing processes. The pellets are input into the post-processing unit 400, and the post-processing process may proceed.

The post-processing process may be performed within the post-processing unit 400. The pellets are introduced into the post-processing unit 400. Thereafter, the post-processing unit 400 can melt the input pellets by friction 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-treatment process may be about 230°C to about 270°C. The temperature of the post-treatment process may be about 230°C to about 260°C. The temperature of the post-treatment process may be about 240°C to about 265°C. The temperature of the post-treatment process may be about 240°C to about 260°C.

The post-treatment 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-treatment process time may be about 1 minute to about 2 minutes.

Thereafter, the resin extruded by the extruder can be cooled, cut, and processed into post-treated pellets. That is, the resin extruded from the extruder can be reprocessed into pellets through the cutting step described above.

The crystallinity of the pellet may be improved in the post-treatment process. Additionally, the content of residues contained in the pellets can be adjusted in the post-treatment process. In particular, the content of oligomers contained in the pellet can be adjusted by the post-treatment process. The content of residual solvent contained in the pellet can be adjusted by the post-treatment process.

Accordingly, the post-treatment process can appropriately adjust the mechanical properties, biodegradability, UV resistance, optical properties, or hydrolysis resistance of the biodegradable polyester resin.

After the pellets are manufactured, the biodegradable polyester resin can be compounded with the heterogeneous biodegradable resin. Additionally, at least one of the inorganic filler, the light stabilizer, the color corrector, or the other additives may be compounded with the biodegradable polyester resin and the heterogeneous biodegradable resin.

The compounding process may be as follows.

The biodegradable polyester resin and the heterogeneous biodegradable resin are mixed with at least one of the inorganic filler, the heat stabilizer, the color corrector, the metal salt, or the other additives, and are put into an extruder. The mixed biodegradable polyester resin composition is melted at a temperature of about 120°C to about 260°C in the extruder and mixed with each other. The melt-mixed biodegradable polyester resin composition is then extruded, cooled, cut, and re-palletized. Through this process, the biodegradable polyester resin composition according to the example can be manufactured by complexing with the heterogeneous biodegradable resin.

Alternatively, the inorganic filler, heat stabilizer, color corrector, metal salt, and other additives may be added during the process of polymerizing the biodegradable polyester resin.

A biodegradable polyester film can be produced using the biodegradable polyester resin according to the example.

The thickness of the biodegradable polyester film may be about 5㎛ to about 300㎛. For example, the thickness of the biodegradable polyester film is about 5㎛ to about 180㎛, about 5㎛ to about 160㎛, about 10㎛ to about 150㎛, about 15㎛ to about 130㎛, about 20㎛ to about 20㎛. It may be 100 μm, about 25 μm to about 80 μm, or about 25 μm to about 60 μm.

The biodegradable polyester film according to the embodiment may have substantially the same degree of hydrolysis and biodegradation as the biodegradable polyester resin composition described above.

Meanwhile, the biodegradable polyester film can be manufactured using the biodegradable polyester resin or biodegradable polyester resin pellets.

Specifically, the method for producing the biodegradable polyester film may include preparing a biodegradable resin composition according to an example and drying and melt-extruding the biodegradable resin composition.

In the step of drying and melt-extruding the biodegradable resin composition, the drying may be performed at about 60°C to about 100°C for about 2 hours to about 12 hours. Specifically, the drying may be performed at about 65°C to about 95°C, about 70°C to about 90°C, or about 75°C to about 85°C for about 3 hours to about 12 hours or about 4 hours to about 10 hours. . When the pellet drying process conditions satisfy the above range, the quality of the biodegradable polyester film or molded article manufactured can be further improved.

In the drying and melt extrusion steps, the melt extrusion may be performed at a temperature of about 270°C or lower. For example, the melt extrusion is performed at a temperature of about 265°C or less, about 260°C or less, about 255°C or less, about 150°C to about 270°C, about 150°C to about 255°C, or about 150°C to about 240°C. It can be. The melt extrusion may be performed by a blown film process. The melt extrusion can be carried out in a T-die.

Additionally, the film manufacturing process may be a calendering process.

Biodegradable polyester molded products

A biodegradable polyester molded article can be manufactured using the biodegradable polyester resin.

Specifically, the molded article may be manufactured by molding the biodegradable polyester resin composition by methods known in the art, such as extrusion and injection, and the molded article may be manufactured by injection molding, extrusion molding, thin film molding, or blow molding. Alternatively, it may be a blow molded product, 3D filament, architectural interior material, etc., but is not limited thereto.

For example, the molded product may be in the form of a film or sheet that can be used as an agricultural mulching film, disposable gloves, disposable film, disposable bag, food packaging material, volume-rate garbage bag, etc., and may be in the form of a fabric, knitted fabric, non-woven fabric, or rope. It may be in the form of a fiber that can be used as a rope, etc. Additionally, as shown in FIG. 2, the molded product may be in the form of a disposable container that can be used as a food packaging container, such as a lunch box. Additionally, the molded product may be of various shapes, such as a disposable straw, spoon, food plate, or fork.

In particular, the molded article can be formed from the biodegradable polyester resin, which can improve physical properties such as shock absorption energy and hardness, as well as impact resistance and durability, so it can be used as a packaging material for products stored and transported at low temperatures, and durability. It can demonstrate excellent properties when applied to automobile interior materials, garbage bags, mulching films, and disposable products.

The physical properties of the biodegradable film and the biodegradable molded article can be measured in a similar manner to the biodegradable polyester resin composition according to the example.

The biodegradable polyester resin composition according to the example may have a molecular weight reduction rate of about 80% or more. The biodegradable polyester resin composition according to the example may have a molecular weight reduction rate of about 85% or more. The biodegradable polyester resin composition according to the example may have a molecular weight reduction rate of about 90% or more. In order to measure the molecular weight reduction rate, the biodegradable polyester resin composition was mixed with compost, and an accelerated biodegradation test was conducted at a temperature of 60°C and a humidity of 90%. Gel permeation chromatography (GPC) was used to measure the number average molecular weight in the polyester resin compositions of Examples and Comparative Examples after 63 days. The molecular weight reduction rate was derived by dividing the difference between the initial number average molecular weight and the number average molecular weight after a certain period of time by the initial number average molecular weight.

The molecular weight reduction rate can be derived from Equation 1 below.

[Equation 1]

Here, the biodegradable polyester resin composition according to the example is mixed with compost and undergoes an accelerated biodegradation test at a temperature of 60°C and a humidity of 90% for about 63 days. The initial number average molecular weight of the biodegradable polyester resin composition before the accelerated biodegradation test was performed and the number average molecular weight after 63 days of the biodegradable polyester resin composition that underwent the accelerated biodegradation test for 63 days were determined by gel permeation chromatography (GPC). It is measured.

The molecular weight reduction rate was derived by dividing the difference between the initial number average molecular weight and the number average molecular weight after a certain period of time, for example, 63 days, by the initial number average molecular weight.

Additionally, the compost may include about 40 wt% of pig manure, about 15 wt% of chicken manure, about 37 wt% of sawdust, about 5 wt% of zeolite, and about 3 wt% of a microbial agent.

In addition, the manufacturer of the compost is Taeheung F&G, and the product name of the compost may be geosaengto (grade 1 compost by-product fertilizer).

In addition, when the molecular weight reduction rate was measured, the biodegradable polyester resin composition according to the example was manufactured into a sheet with a thickness of about 300㎛. Then, the prepared sheet was cut into a size of about 3cm x 3cm. , flakes are manufactured. The flakes are mixed with the compost, and the accelerated biodegradation test is performed.

The biodegradable polyester film according to the example may have the molecular weight reduction rate as described above. Likewise, the biodegradable polyester film according to the example is cut to a size of about 3 cm x 3 cm, and flakes are produced. The flakes may be mixed with the compost, and the accelerated biodegradation test may be performed.

The biodegradable polyester resin composition according to the example may have a biodegradability of about 80% or more. The biodegradable polyester resin composition according to the example may have a biodegradability of about 85% or more. The biodegradable polyester resin composition according to the example may have a biodegradability of about 90% or more. The biodegradability can be derived from Equation 2 below.

[Equation 2]

The biodegradability of the biodegradable polyester resin composition according to the example can be measured based on the amount of carbon dioxide generated according to KS M3100-1. Specifically, an inoculum container containing only compost produced in a compost factory is prepared, and a test container is prepared in which flakes of the biodegradable polyester resin composition of 5% by weight of the dry weight of the compost are added to the compost. Thereafter, the compost and the flakes are cultured for 180 days under conditions of a temperature of 58 ± 2°C, a moisture content of 50%, and an oxygen concentration of 6% or more, and carbon dioxide generated in each container is captured and generated in each container by titration of an aqueous phenolphthalein solution. The amount of carbon dioxide generated is measured. As shown in Equation 2 above, the biodegradability was derived as the ratio of carbon dioxide generated from the biodegradable polyester resin composition compared to the theoretical amount of carbon dioxide generated.

When the biodegradability is measured, flakes of the biodegradable polyester resin composition can be produced substantially the same as flakes when the molecular weight reduction rate is measured.

The biodegradable polyester film according to the embodiment may have the biodegradability as described above. Likewise, the biodegradable polyester film according to the example is cut to a size of about 3 cm x 3 cm, and flakes are produced. The flakes may be mixed with the compost, and the biodegradation test may be performed.

The degree of hydrolysis of the biodegradable polyester resin composition according to the example can be measured by the following method.

In order to measure the degree of hydrolysis, the biodegradable resin composition according to the above example is immersed in water (100% RH) at 80°C, and then an accelerated degree of hydrolysis test is performed. After a certain period of time, gel permeation chromatography (GPC) was used to measure the number average molecular weight of the biodegradable polyester resin composition according to the example. The degree of hydrolysis was derived as the difference between the initial number average molecular weight and the number average molecular weight after hydrolysis for a certain period of time divided by the initial number average molecular weight.

The degree of hydrolysis can be expressed by Equation 3 below.

[Formula 3]

Here, the biodegradable polyester resin composition according to the example is immersed in water at 80°C and then subjected to an accelerated hydrolysis test for a certain period of time. The initial number average molecular weight of the biodegradable polyester resin composition before the accelerated hydrolysis test was performed and the number average molecular weight after hydrolysis of the biodegradable polyester resin composition that underwent the accelerated hydrolysis test for a certain period of time were determined by gel permeation chromatography (GPC). It is measured by

The degree of hydrolysis was derived as the difference between the initial number average molecular weight and the number average molecular weight after hydrolysis for a certain period of time divided by the initial number average molecular weight.

In addition, when the degree of hydrolysis is measured, the biodegradable polyester resin composition according to the example is manufactured into a sheet with a thickness of about 300㎛. Afterwards, the prepared sheet is cut into a size of about 3cm x 3cm. , flakes are manufactured. The flakes may be immersed in the hot water to perform the accelerated hydrolysis test.

In the biodegradable polyester resin composition according to the example, the degree of hydrolysis after one week may be about 40% to about 65%. In the biodegradable polyester resin composition according to the example, the degree of hydrolysis after one week may be about 45% to about 63%.

In the biodegradable polyester resin composition according to the example, the degree of hydrolysis after 2 weeks may be about 80% to about 93%. In the biodegradable polyester resin composition according to the example, the degree of hydrolysis after 2 weeks may be about 85% to about 92%.

In the biodegradable polyester resin composition according to the example, the degree of hydrolysis after 3 weeks may be about 90% to about 97%. In the biodegradable polyester resin composition according to the example, the degree of hydrolysis after 3 weeks may be about 91% to about 96%.

In the biodegradable polyester resin composition according to the example, the degree of hydrolysis after 4 weeks may be about 92% to about 99%. In the biodegradable polyester resin composition according to the example, the degree of hydrolysis after 4 weeks may be about 93% to about 97%.

In the biodegradable polyester resin composition according to the example, the degree of hydrolysis after 6 weeks may be about 94% or more. In the biodegradable polyester resin composition according to the example, the degree of hydrolysis after 6 weeks may be about 95% or more.

In the biodegradable polyester resin composition according to the example, the degree of hydrolysis after 9 weeks may be about 95% or more. In the biodegradable polyester resin composition according to the example, the degree of hydrolysis after 9 weeks may be about 96% or more.

The biodegradable polyester resin composition according to the example may have a reduction rate in wet hardness. The wet hardness reduction rate is obtained by dividing the difference between the initial hardness before immersion and the wet hardness after immersion by the initial hardness after the biodegradable polyester resin composition is immersed in water at a certain temperature for a certain period of time.

The wet hardness reduction rate can be derived from Equation 4 below.

[Formula 4]

In the biodegradable polyester resin composition according to the example, the wet hardness reduction rate after immersion at a temperature of about 30° C. for about 24 hours may be about 16% or less. After immersion at the temperature of 30°C for about 24 hours, the rate of decline in wet hardness may be about 15% or less. After immersion for 24 hours at a temperature of 30° C., the rate of decline in wet hardness may be about 14% or less. After immersion at the temperature of 30°C for 24 hours, the rate of decline in wet hardness may be about 13% or less. After immersion at the temperature of 30°C for 24 hours, the rate of decline in wet hardness may be about 12% or less. The minimum rate of decline in wet hardness after immersion at a temperature of 30° C. for 24 hours may be about 1%, about 3%, about 5%, or about 6%.

The rate of decline in wet hardness after immersion at a temperature of 30° C. for 24 hours can be measured by the following measurement method. First, the biodegradable polyester resin composition is processed to produce a polyester block with a thickness of about 2.5 mm. The initial hardness of the polyester block is measured before immersion, and the wet hardness of the polyester block is measured immediately after the polyester block is immersed in water at about 30° C. for about 24 hours. Thereafter, the rate of decline in wet hardness after immersion at a temperature of 30° C. for 24 hours can be derived according to Equation 4 above.

The biodegradable polyester resin composition is dried to a moisture content of about 500 ppm at a temperature of about 80°C for about 20 minutes, placed in a stainless steel mold, and incubated at a temperature of about 210°C and a pressure of about 10 MPa for about 5 minutes. When compressed, a polyester block with a thickness of approximately 2.5 mm can be produced.

The initial hardness may be about 30 to about 45 Shore D hardness. The initial hardness may be about 33 to about 43 in Shore D hardness. The initial hardness may be about 35 to about 41 Shore D hardness.

The wet hardness after immersion at a temperature of 30° C. for 24 hours may be about 28 to about 43 in Shore D hardness. The wet hardness after immersion at a temperature of 30° C. for 24 hours may be about 29 to about 41 in Shore D hardness. After immersion for 1 hour at a temperature of 30° C., wet hardness may be about 30 to about 38 in Shore D hardness.

After immersion for 0.5 hours at a temperature of 30°C, the rate of decline in wet hardness may be about 16% or less. After immersion for 0.5 hours at a temperature of 30° C., the rate of decline in wet hardness may be about 15% or less. After immersion for 0.5 hours at a temperature of 30° C., the rate of decline in wet hardness may be about 14% or less. After immersion for 0.5 hours at a temperature of 30° C., the rate of decline in wet hardness may be about 13% or less. After immersion for 0.5 hours at a temperature of 30° C., the rate of decline in wet hardness may be about 12% or less. The minimum rate of decline in wet hardness after immersion at a temperature of 30° C. for 0.5 hours may be about 1%, about 3%, about 5%, or about 6%.

After immersion for 0.5 hours at a temperature of 30° C., wet hardness may be about 28 to about 43 in Shore D hardness. After immersion for 0.5 hours at a temperature of 30° C., wet hardness may be about 29 to about 41 in Shore D hardness. The wet hardness after immersion for 0.5 hours at a temperature of 30° C. may be about 30 to about 39 in Shore D hardness.

The deviation of the wet hardness reduction rate after immersion at a temperature of 30°C for 24 hours and the wet hardness reduction rate after immersion at a temperature of 30°C for 0.5 hours may be about 10% or less. The deviation of the wet hardness reduction rate after immersion at a temperature of 30°C for 24 hours and the wet hardness reduction rate after immersion at a temperature of 30°C for 0.5 hours is the wet hardness after immersion at a temperature of 30°C for 24 hours and 0.5 at a temperature of 30°C. It is the absolute value of the difference in wet hardness after immersion for a period of time divided by the initial hardness. The deviation of the wet hardness reduction rate after immersion at a temperature of 30°C for 24 hours and the wet hardness reduction rate after immersion at a temperature of 30°C for 0.5 hours may be about 7% or less. The deviation of the wet hardness reduction rate after immersion at a temperature of 30°C for 24 hours and the wet hardness reduction rate after immersion at a temperature of 30°C for 0.5 hours may be about 5% or less.

After immersion for 1 hour at a temperature of 30°C, the rate of decline in wet hardness may be about 16% or less. After immersion for 1 hour at a temperature of 30° C., the rate of decline in wet hardness may be about 15% or less. After immersion for 24 hours at a temperature of 30° C., the rate of decline in wet hardness may be about 14% or less. After immersion at the temperature of 30°C for 24 hours, the rate of decline in wet hardness may be about 13% or less. After immersion at the temperature of 30°C for 24 hours, the rate of decline in wet hardness may be about 12% or less. The minimum rate of decline in wet hardness after immersion at a temperature of 30° C. for 1 hour may be about 1%, about 3%, about 5%, or about 6%.

After immersion for 1 hour at a temperature of 30° C., wet hardness may be about 28 to about 43 in Shore D hardness. After immersion for 1 hour at a temperature of 30° C., wet hardness may be about 29 to about 41 in Shore D hardness. After immersion for 1 hour at a temperature of 30° C., wet hardness may be about 30 to about 39 in Shore D hardness.

The deviation of the wet hardness reduction rate after immersion at a temperature of 30°C for 1 hour and the wet hardness reduction rate after immersion at a temperature of 30°C for 24 hours may be about 10% or less. The deviation of the wet hardness reduction rate after immersion at a temperature of 30°C for 1 hour and the wet hardness reduction rate after immersion at a temperature of 30°C for 24 hours may be about 7% or less. The deviation of the wet hardness reduction rate after immersion at a temperature of 30°C for 1 hour and the wet hardness reduction rate after immersion at a temperature of 30°C for 24 hours may be about 5% or less.

After immersion at a temperature of 30°C for 18 hours, the rate of decline in wet hardness may be about 16% or less. After immersion at the temperature of 30°C for 18 hours, the rate of decline in wet hardness may be about 15% or less. After immersion at the temperature of 30°C for 18 hours, the rate of decline in wet hardness may be about 14% or less. After immersion for 18 hours at a temperature of 30° C., the rate of decline in wet hardness may be about 13% or less. After immersion at the temperature of 30°C for 18 hours, the rate of decline in wet hardness may be about 12% or less. The minimum rate of decline in wet hardness after immersion at a temperature of 30° C. for 18 hours may be about 1%, about 3%, about 5%, or about 6%.

After immersion for 18 hours at a temperature of 30° C., wet hardness may be about 28 to about 43 in Shore D hardness. The wet hardness after immersion at a temperature of 30° C. for 18 hours may be about 29 to about 41 in Shore D hardness. The wet hardness after immersion at a temperature of 30° C. for 18 hours may be about 30 to about 39 in Shore D hardness.

The deviation of the wet hardness reduction rate after immersion at a temperature of 30°C for 24 hours and the wet hardness reduction rate after immersion at a temperature of 30°C for 18 hours may be about 10% or less. The deviation of the wet hardness reduction rate after immersion at a temperature of 30°C for 24 hours and the wet hardness reduction rate after immersion at a temperature of 30°C for 18 hours may be about 7% or less. The deviation of the wet hardness reduction rate after immersion at a temperature of 30°C for 24 hours and the wet hardness reduction rate after immersion at a temperature of 30°C for 18 hours may be about 5% or less.

After immersion at a temperature of about 50°C for 24 hours, the rate of decline in wet hardness may be about 16% or less. After immersion at the temperature of 50°C for 24 hours, the rate of decline in wet hardness may be about 15% or less. After immersion at the temperature of 50°C for 24 hours, the rate of decline in wet hardness may be about 14% or less. After immersion at the temperature of 50°C for 24 hours, the rate of decline in wet hardness may be about 13% or less. After immersion at the temperature of 50°C for 24 hours, the rate of decline in wet hardness may be about 12% or less. The minimum rate of decline in wet hardness after immersion at a temperature of 50° C. for 24 hours may be about 1%, about 3%, about 5%, or about 6%.

The wet hardness after immersion at a temperature of 50° C. for 24 hours may be about 28 to about 43 in Shore D hardness. The wet hardness after immersion at a temperature of 50° C. for 24 hours may be about 29 to about 41 in Shore D hardness. The wet hardness after immersion at a temperature of 50° C. for 24 hours may be about 30 to about 39 in Shore D hardness.

The deviation of the wet hardness reduction rate after immersion at a temperature of 30°C for 24 hours and the wet hardness reduction rate after immersion at a temperature of 50°C for 24 hours may be about 10% or less. The deviation of the wet hardness reduction rate after immersion at a temperature of 30°C for 24 hours and the wet hardness reduction rate after immersion at a temperature of 50°C for 24 hours may be about 7% or less. The deviation of the wet hardness reduction rate after immersion at a temperature of 30°C for 24 hours and the wet hardness reduction rate after immersion at a temperature of 50°C for 24 hours may be about 5% or less.

After immersion at a temperature of 70°C for 24 hours, the rate of decline in wet hardness may be about 16% or less. After immersion at the temperature of 70°C for 24 hours, the rate of decline in wet hardness may be about 15%. After immersion at the temperature of 70°C for 24 hours, the rate of decline in wet hardness may be about 14% or less. After immersion at a temperature of 70° C. for 24 hours, the rate of decline in wet hardness may be about 13% or less. After immersion at the temperature of 50°C for 24 hours, the rate of decline in wet hardness may be about 12% or less. The minimum rate of decline in wet hardness after immersion at a temperature of 50° C. for 24 hours may be about 1%, about 3%, about 5%, or about 6%.

The wet hardness after immersion at a temperature of 70° C. for 24 hours may be about 28 to about 43 in Shore D hardness. The wet hardness after immersion at a temperature of 70° C. for 24 hours may be about 29 to about 41 in Shore D hardness. The wet hardness after immersion at a temperature of 70° C. for 1 hour may be about 30 to about 39 in Shore D hardness.

The deviation of the wet hardness reduction rate after immersion at a temperature of 30°C for 24 hours and the wet hardness reduction rate after immersion at a temperature of 70°C for 24 hours may be about 10% or less. The deviation of the wet hardness reduction rate after immersion at a temperature of 30°C for 24 hours and the wet hardness reduction rate after immersion at a temperature of 70°C for 24 hours may be about 7% or less. The deviation of the wet hardness reduction rate after immersion at a temperature of 30°C for 24 hours and the wet hardness reduction rate after immersion at a temperature of 70°C for 24 hours may be about 5% or less.

Additionally, the acid value of the biodegradable polyester resin composition according to the example may be about 0.01 mg KOH/g to about 3 mg KOH/g. The acid value of the biodegradable polyester resin composition according to the embodiment may be about 0.1 mg KOH/g to about 2.5 mg KOH/g. The acid value of the biodegradable polyester resin composition according to the example may be about 0.1 mg KOH/g to about 2.3 mg KOH/g.

Since the biodegradable polyester resin composition according to the embodiment has an acid value within the above range, it may have the same hydrolysis properties and biodegradability properties as above.

Additionally, the biodegradable polyester resin composition according to the example may contain silicon element. The silicon element may be derived from the hydrolysis resistant agent, etc. The content of the silicon element may be about 0.1 ppm to about 1000 ppm based on the biodegradable polyester resin composition according to the example. The content of the silicon element may be about 0.5 ppm to about 500 ppm based on the biodegradable polyester resin composition according to the example. The content of the silicon element may be about 1 ppm to about 100 ppm based on the biodegradable polyester resin composition according to the example. The content of the silicon element may be about 1ppm to about 50ppm based on the biodegradable polyester resin composition according to the example.

Additionally, the biodegradable polyester resin composition according to the example may contain a metal element. The metal element may be derived from the metal salt. The content of the metal element may be about 0.1 ppm to about 200 ppm based on the biodegradable polyester resin composition according to the example. The content of the metal element may be about 0.5 ppm to about 150 ppm based on the biodegradable polyester resin composition according to the example. The content of the metal element may be about 1ppm to about 100ppm based on the biodegradable polyester resin composition according to the example. The content of the metal element may be about 1 ppm to about 50 ppm based on the biodegradable polyester resin composition according to the example.

Additionally, the biodegradable polyester resin composition according to the example may contain iron element. The elemental iron may be derived from the metal salt. The content of the iron element may be about 0.1 ppm to about 200 ppm based on the biodegradable polyester resin composition according to the example. The content of the iron element may be about 0.5ppm to about 150ppm based on the biodegradable polyester resin composition according to the example. The content of the iron element may be about 1 ppm to about 100 ppm based on the biodegradable polyester resin composition according to the example. The content of the iron element may be about 1ppm to about 50ppm based on the biodegradable polyester resin composition according to the example.

In addition, the content ratio of the iron element to the content of the silicon element (ppm content of iron element / ppm content of silicon element) may be about 0.1 to about 0.8. The content ratio of the iron element to the content of the silicon element (ppm content of iron element / ppm content of silicon element) may be about 0.1 to about 0.7. The content ratio of the iron element to the content of the silicon element (ppm content of iron element / ppm content of silicon element) may be about 0.3 to about 0.7. The content ratio of the iron element to the content of the silicon element (ppm content of iron element / ppm content of silicon element) may be about 0.35 to about 0.65.

Since the biodegradable polyester resin composition according to the embodiment contains the silicon element and the iron element in the above range, it may have an appropriate degree of hydrolysis and an appropriate degree of biodegradation. In particular, the degree of hydrolysis can be appropriately adjusted depending on the content of the silicon element, and the degree of biodegradation can be appropriately adjusted depending on the content of the iron element.

The content of the silicon element and the metal can be measured by Inductively Coupled Plasma Optical Emission Spectroscopy.

In the biodegradable polyester resin composition according to the example, the wet hardness reduction rate is 15% or less. Accordingly, the biodegradable polyester resin composition according to the example may have high moisture resistance. The biodegradable polyester resin composition according to the example can maintain high mechanical properties even when exposed to water or in a high humidity environment.

Accordingly, the biodegradable polyester resin composition according to the example can minimize variation in mechanical properties when used for packaging moisture-rich foods, etc.

Additionally, the biodegradable polyester resin composition according to the example may have hydrophobic properties. Accordingly, the biodegradable polyester resin composition according to the example may absorb less moisture in the air. Accordingly, the biodegradable polyester resin composition according to the example may have improved storage stability.

The biodegradable polyester resin composition according to the example may include a silicone-based hydrolysis resistant agent. Accordingly, the biodegradable polyester resin composition according to the example may have improved hydrolysis resistance. In addition, the silicone-based hydrolysis resistant agent may function as a coupling agent to couple the polymer resin included in the condensation polymerization composition.

Accordingly, the silicone-based hydrolysis resistant agent can improve the degree of polymerization of the biodegradable polyester resin composition according to the example.

Accordingly, the biodegradable polyester resin composition according to the example has improved physical properties during the actual use period and can be easily biodegraded after use.

The biodegradable polyester resin composition according to the example can be efficiently applied to packaging films, etc. That is, the film made from the biodegradable polyester resin composition according to the example can be used for general purposes such as packaging. At this time, the biodegradable polyester resin composition according to the embodiment may initially have a low degree of hydrolysis, and the biodegradable polyester film may maintain mechanical and chemical properties above a certain level within a normal period of use by the user.

At the same time, because the biodegradable polyester resin composition according to the embodiment has a high biodegradability, the film manufactured by the biodegradable polyester resin composition according to the embodiment can be easily decomposed when discarded after use. there is.

The above will be explained in more detail by the following examples. However, the following examples are only for illustrating the present invention, and the scope of the examples is not limited to these only.

<Manufacturing example>

Preparation of pretreated cellulose nanocrystals

Cellulose nanocrystals (NVC-100, manufacturer: Celluforce) in the form of dry powder having a particle size of about 1 ㎛ to about 50 ㎛ are dispersed in water at 1% by weight, and then subjected to tip-type ultrasonic waves. Pretreated nanocellulose was prepared by sonicating for 1 minute at an output of 20000 J/s using a disperser.

Hydrolysis resistant agent: 3-Glycidyloxypropyltriethoxysilane

Metal salt: iron(II) acetate

Polycarbonate diol (RAVECARB 106, Caffaro Industrie)

<Example>

Example 1

Manufacturing of biodegradable polyester resin

Step 1: Obtaining slurry by pretreatment

As shown in Table 1, pretreated nanocellulose, iron(II) acetate, 1,4-butanediol (1,4-BDO), and terephthalic acid (TPA) were mixed at a molar ratio (1,4-BDO:TPA) of 1.2:1. It was mixed and placed in a slurry tank (the lowest part of the slurry tank is an anchor type, the height to the agitator is 40 mm, and it is equipped with three rotary blades) in a non-catalyst state. At this time, the D50 of the terephthalic acid (TPA) was 130㎛, and the standard deviation (SD) of the D50 of the terephthalic acid (TPA) was 3.0.

At this time, the contents of the nanocellulose and the iron (II) acetate were as shown in Table 1 below, based on the total weight of terephthalic acid, 1,4-butanediol, and adipic acid added.

Next, the mixture was pretreated by stirring at 60°C and 100rpm for 1 hour, and a slurry was obtained without phase separation.

Step 2: Obtaining the prepolymer

The slurry obtained in the first step is introduced into the reactor through the supply line, and 250 ppm of tetrabutyl titanate (Dupont, Tyzor TnBT product), a titanium-based catalyst, is added thereto, and then 95% of the water as a by-product is dissolved at 220°C and normal pressure. The first esterification reaction was carried out for about 1 hour and 30 minutes until discharge.

The reaction product contains 53 mol% of 1,4-butanediol (1,4-BDO) based on the total moles of diol components, 53 mol% of adipic acid (AA) based on the total moles of dicarboxylic acid components, and polycarbonate diol. And after adding 200 ppm of tetrabutyl titanate (Dupont, Tyzor TnBT product), a titanium catalyst, based on the total weight of diol, aromatic dicarboxylic acid, and aliphatic dicarboxylic acid, water as a by-product was dissolved at 210°C and normal pressure. A secondary esterification reaction was performed for about 2 hours and 30 minutes until 95% was discharged to prepare a prepolymer with a number average molecular weight of 1500 g/mol. The content of the polycarbonate diol was as shown in Table 1 below, based on 100 parts by weight of the total terephthalic acid, 1,4-butanediol, and adipic acid added.

Step 3: Condensation polymerization reaction

Based on the total weight of the prepolymer, 400 ppm of a titanium catalyst, tetrabutyl titanate (Dupont, Tyzor TnBT product) and 500 ppm of a triethylene phosphate stabilizer were added and stabilized for about 10 minutes. Thereafter, the reaction mixture was heated to 250°C, and a condensation polymerization reaction was performed at 0.5 torr for 4 hours to prepare a polymer having a number average molecular weight of 55,000 g/mol.

Thereafter, about 1 part by weight of a hydrolysis-resistant agent was added to the polymer based on 100 parts by weight of the polymer. Afterwards, the polymer underwent an end group extension reaction at a temperature of about 240°C for about 10 minutes. Afterwards, it was cooled to 5°C and cut with a pellet cutting machine to obtain biodegradable polyester resin pellets.

Examples 2 to 6 and Comparative Examples 1 to 2

As shown in Table 1 below, the contents of adipic acid, terephthalic acid, cellulose nanocrystals, and hydrolysis resistant agent vary. Except for the above content and the above process, the remaining processes were carried out with substantial reference to Example 1.

Manufacturing of biodegradable polyester sheets

After preparing two Teflon sheets, place a stainless steel (SUS) mold (area 12cm It was covered with another Teflon sheet and placed in the center of a hot press (Hot Press, manufacturer: With Lab, model name: WL 1600SA) with a surface size of approximately 25cmX25cm. This was maintained at about 210°C for about 3 minutes under a pressure of about 10Mpa, then detached and immediately cooled in water at about 20°C for about 30 seconds, and then formed into biodegradable polyester with an area of about 10cmX10cm and a thickness of about 300㎛. A sheet was manufactured.

Manufacturing of biodegradable polyester film

The biodegradable polyester resin pellets were dried at 80°C for 5 hours, then melt-extruded at 160°C using a blown film extrusion line (manufacturer: Eugene Engineering) to produce biodegradable polyester with a thickness of 50㎛. A film was prepared.

division 1,4-BDO
(mol%) TPA
(mol%) AA
(mol%) CNC
(ppm) metal salt
(ppm) polycarbonate diol
(part by weight) hydrolyzing agent
(part by weight) Example 1 120 47 53 100 0.1 Example 2 120 50 50 700 One Example 3 120 48 52 100 Example 4 120 45 55 700 3 Example 5 120 55 45 100 0.5 Example 6 120 49 51 100 3 Example 7 120 60 40 Comparative example 120 40 60

Evaluation example

Evaluation Example 1: Average particle size (D50) and standard deviation

<Average particle size (D50) and standard deviation of aromatic dicarboxylic acid>

From particle size distribution (PSD), the average particle size (D50) and standard deviation (SD) of aromatic dicarboxylic acid (TPA or DMT) were obtained using a particle size analyzer Microtrac S3500 (Microtrac Inc) under the following conditions:

Usage environment

- Temperature: 10 to 35℃, Humidity: 90% RH, non-condensing maximum

- D50 and SD, the average particle size distribution for each section, were measured.

The standard deviation means the square root of the variance, and can be calculated using software.

<Particle size of nanocellulose>

For nanocellulose, particle size and particle size deviation were measured using the principle of dynamic light scattering (DLS) at a temperature of 25°C and a measurement angle of 175° using Zetasizer Nano ZS (manufacturer: Marven). At this time, the peak value derived through the polydispersity index (PdI) in the confidence interval of 05 was measured as the particle size.

Evaluation Example 2: Degree of hydrolysis

The biodegradable polyester resin prepared in Examples and Comparative Examples was immersed in water (100% RH) at 80°C, and then an accelerated water solubility test was performed.

Specifically, 5 g of the polyester resin of Examples and Comparative Examples was added to 500 mL of deionized water (DI Water), then blocked with a stopper to prevent water from evaporating, and an accelerated water decomposition test was performed in a convection (hot air) oven at 80°C. The humidity environment of the biodegradable polyester sheet is the same as operating at 100% RH because it is immersed in water.

The following gel permeation chromatography (GPC) was used to measure the number average molecular weight of the polyester resins of Examples and Comparative Examples after a certain period of time had elapsed. The degree of hydrolysis was derived by dividing the difference between the initial number average molecular weight and the number average molecular weight after a certain period of time by the initial number average molecular weight.

GPC equipment and measurement conditions are as follows.

Sample preparation: Dissolve 0.035 mg of PBAT chip in 1.5 ml of THF.

Measuring device: waters e2695

Flow rate: 1ml/min in THF

Injection volume: 50 μl

Column Temp: 40℃

Detector: ELSD

Column: Styragel Column HR 5E, HR4, HR2

Evaluation Example 3: Biodegradability

The biodegradable polyester resin prepared in Examples and Comparative Examples was mixed with the following compost, and an accelerated biodegradation test was performed at a temperature of 60°C and a humidity of 90%.

The gel permeation chromatography (GPC) was used to measure the number average molecular weight of the polyester resins of Examples and Comparative Examples after a certain period of time. The biodegradability was derived by dividing the difference between the initial number average molecular weight and the number average molecular weight after a certain period of time by the initial number average molecular weight.

compost

Manufacturer: Taeheung F&G

Product name: Geosangsoil (grade 1 compost by-product fertilizer)

Compost ingredients: 40wt% pork manure, 15wt% chicken manure, 37wt% sawdust, 5wt% zeolite, 3wt% microbial agent.

Evaluation Example 4 Shore D hardness

The hardness of the polyester block was measured by a Shore hardness measuring instrument (SAUTER® Digital Professional Shore Hardness Tester). Thereafter, the polyethylene block is cut to a size of about 3 cm After immersion for about 24 hours, the water of the sample was removed, and the wet hardness was immediately measured using the Shore hardness measuring instrument.

Evaluation Example 5: Water contact angle and polarity

On the surface of the biodegradable polyester sheets prepared in Examples and Comparative Examples, water contact angle and polarity were measured under the following conditions.

Surface Tension: Wet Tension Test Mixture No. 40~64

Manufacturer: Waco

Ingredients: Ethylene glycol, monoethyl ether

Surface energy meter: MSA One-Click SFE (product name) / KRUSS (manufacturer)

Evaluation Example 6: Iron and silicon content

The biodegradable polyester pellets prepared in Examples and Comparative Examples were dissolved in strong acid, and the iron and silicon contents were measured by ICP OES.

Device: Agilent 5110 SVDV

Measuring conditions

RF power:1.2 KW

Nebulizer flow: 0.7 L/min

Plasma flow: 12 L/min

Aux flow :1L/min

Read time: 5 s

As shown in Table 2 below, the degree of hydrolysis was measured.

division 7-day molecular weight reduction rate (%) 14-day molecular weight reduction rate (%) 21-day molecular weight reduction rate (%) 28-day molecular weight reduction rate (%) 42-day molecular weight reduction rate (%) 63-day molecular weight reduction rate (%) Example 1 45 86 94 95 97 97 Example 2 57 89 94 96 97 97 Example 3 52 86 94 96 97 97 Example 4 48 87 94 95 96 97 Example 5 43 86 94 96 97 97 Example 6 58 89 94 96 97 97 Example 7 45 86 93 95 96 96 Comparative example 62 90 95 97 97 97

As shown in Table 3 below, the molecular weight reduction rate and biodegradability were derived.

division Molecular weight reduction rate (%) Biodegradability (%) Example 1 90 90 Example 2 91 91 Example 3 91 90 Example 4 90 90 Example 5 91 90 Example 6 90 90 Example 7 92 91 Comparative example 82 84

As shown in Table 4 below, the content of iron element and silicon element content were measured.

division iron content
(ppm) silicone content
(ppm) Example 1 37 95 Example 2 Not detected Not detected Example 3 36 Not detected Example 4 Not detected Not detected Example 5 39 412 Example 6 38 Not detected Example 7 Not detected Not detected Comparative example Not detected Not detected

As shown in Tables 5 to 7 below, the initial hardness and wet hardness were measured for each temperature and each immersion time.

division initial hardness
(Shore D) 30℃
0.5 hours
wet hardness
(Shore D) 30℃
1 hours
wet hardness
(Shore D) 30℃
18 hours
wet hardness
(Shore D) 30℃
24 hours
wet hardness
(Shore D) Example 1 37.2 33.9 33.6 34.1 33.2 Example 2 36.6 33.3 33.6 33.7 33.5 Example 3 36.8 33.4 33.1 33.9 33.5 Example 4 36.1 32.6 32.8 32.9 32.8 Example 5 37.9 33.1 33.1 33.2 33.0 Example 6 36.4 33.6 33.0 33.2 33.0 Example 7 40.2 38.2 38.1 38.2 37.9 Comparative example 38.1 27.4 27.2 27.9 27.3

division initial hardness
(Shore D) 50℃
0.5 hours
wet hardness
(Shore D) 50℃
1 hours
wet hardness
(Shore D) 50℃
18 hours
wet hardness
(Shore D) 50℃
24 hours
wet hardness
(Shore D) Example 1 37.2 34.0 33.8 34.0 33.5 Example 2 36.6 33.3 33.7 33.9 33.2 Example 3 36.8 33.1 33.9 33.7 33.5 Example 4 36.1 32.7 32.9 32.7 33.0 Example 5 37.9 32.6 32.7 33.3 32.6 Example 6 36.4 32.9 32.5 33.0 33.7 Example 7 40.2 38.1 38.3 37.7 37.8 Comparative example 38.1 27.6 27.4 28.0 27.5

division initial hardness
(Shore D) 70℃
0.5 hours
wet hardness
(Shore D) 70℃
1 hours
wet hardness
(Shore D) 70℃
18 hours
wet hardness
(Shore D) 70℃
24 hours
wet hardness
(Shore D) Example 1 37.2 33.9 33.8 33.7 33.8 Example 2 36.6 33.5 33.7 33.6 33.3 Example 3 36.8 33.3 32.8 34 33.4 Example 4 36.1 32.6 32.7 32.8 33.0 Example 5 38.4 32.7 32.4 33.1 33.6 Example 6 36.4 32.6 32.3 32.8 32.1 Example 7 40.2 37.8 37.9 37.6 38.0 Comparative example 38.1 27.5 27.4 28.1 28.0

As shown in Table 8 below, the surface properties of the biodegradable polyester sheets prepared by Examples and Comparative Examples were derived.

division surface tension
(dyne) water contact angle
(˚) Diiodomethane contact angle
(˚) surface free energy
(mN/m) dispersion
(mN/m) polarity
(mN/m) Example 1 39 81.11 36.15 47.34 41.87 4.69 Example 2 40 82.15 33.44 48.3 42.9 4.63 Example 3 39 78.16 34.63 47.3 42.6 4.94 Example 4 41 82.46 33.3 45.2 41.1 4.63 Example 5 40 77.91 34.13 48.1 42.7 4.77 Example 6 39 83.53 32.8 46.5 41.3 4.59 Example 7 39 91.5 41.5 45.3 40.3 4.31 Comparative example 38 69.5 22.3 55.3 49.5 6.18

As shown in Tables 2 to 8, it was found that the biodegradable resin compositions according to the examples had appropriate degrees of hydrolysis and biodegradability.

In addition, as shown in Tables 2 to 8, it was found that the biodegradable resin compositions according to the examples had an appropriate wet hardness change rate and appropriate surface properties.

Slurry Agitator 100
Esterification reaction unit 200
Condensation polymerization reaction unit 300
Post processing unit 400
1st recovery unit 510
2nd recovery unit 520

Claims (12)

Contains a polyester resin containing diol, aromatic dicarboxylic acid and aliphatic dicarboxylic acid,
The wet hardness reduction rate is 15% or less,
The water contact angle of the surface of the polyester block below is 45° to 85°,
Contains iron element in a content of 1 ppm to 100 ppm,
The biodegradable polyester resin composition wherein the wet hardness reduction rate is measured by the following measurement method.
[measurement method]
The biodegradable polyester resin composition is used to produce a polyester block having a thickness of 2.5 mm, the initial hardness of the polyester block and the wet hardness after the polyester block is immersed in water at 30° C. for 24 hours. is measured, and the wet hardness decline rate is the difference between the wet hardness and the initial hardness divided by the initial hardness. The method of claim 1, wherein the initial hardness is Shore D hardness and is 30 to 45,
The wet hardness is Shore D hardness, and is a biodegradable polyester resin composition of 28 to 43. The biodegradable polyester resin composition according to claim 1, wherein the wet hardness reduction rate is 12% or less. The biodegradable polyester resin composition according to claim 1, wherein the silicon element content is 0.1 ppm to 1000 ppm. delete The biodegradable polyester resin composition of claim 1, wherein the difference between the wet hardness after immersion in water at 30°C for 1 hour and the wet hardness after immersion in water at 30°C for 24 hours is 10% or less based on the initial hardness. . The biodegradable polyester resin composition of claim 1, wherein the difference between wet hardness after immersion in water at 30°C for 24 hours and wet hardness after immersion in water at 70°C for 24 hours is 10% or less based on the initial hardness. . delete delete The method of claim 1, wherein the degree of hydrolysis is 35% to 60% after 1 week,
After 3 weeks, the degree of hydrolysis is more than 85%,
A biodegradable polyester resin composition in which the degree of hydrolysis after 1 week and the degree of hydrolysis after 3 weeks are measured by the following measurement method.
[measurement method]
The degree of hydrolysis after 1 week is the rate of decrease in number average molecular weight of the biodegradable polyester resin composition compared to the initial stage when the biodegradable polyester resin composition is placed for 1 week under high temperature and high humidity conditions of 80° C. and 100% humidity. ,
The degree of hydrolysis after 3 weeks is the rate of decrease in number average molecular weight of the biodegradable polyester resin composition compared to the initial stage when the biodegradable polyester resin composition is placed for 3 weeks under high temperature and high humidity conditions of 80°C and 100% humidity. . Contains a polyester resin containing diol, aromatic dicarboxylic acid and aliphatic dicarboxylic acid,
The wet hardness reduction rate is 15% or less,
The water contact angle of the surface of the polyester block below is 45° to 85°,
Contains iron element in a content of 1 ppm to 100 ppm,
The biodegradable polyester film wherein the wet hardness reduction rate is measured by the following measurement method.
[measurement method]
The biodegradable polyester film is laminated to produce a polyester block with a thickness of 2.5 mm, and the initial hardness of the polyester block and the wet hardness after the polyester block is immersed in water at 30° C. for 24 hours are Measured, the wet hardness reduction rate is the difference between the wet hardness and the initial hardness divided by the initial hardness. Contains a polyester resin containing diol, aromatic dicarboxylic acid and aliphatic dicarboxylic acid,
The wet hardness reduction rate is 15% or less,
The water contact angle of the surface of the polyester block below is 45° to 85°,
Contains iron element in a content of 1 ppm to 100 ppm,
A biodegradable molded product in which the wet hardness reduction rate is measured by the following measurement method.
[measurement method]
The biodegradable molded article is processed to produce a polyester block with a thickness of 2.5 mm, and the initial hardness of the polyester block and the wet hardness after the polyester block is immersed in water at 30° C. for 24 hours are measured. , the wet hardness reduction rate is the difference between the wet hardness and the initial hardness divided by the initial hardness.