Polylactic acid resin vaporation accelerator and composition containing same

Abstract

Embodiments of the present invention relate to: a composition containing at least 10 wt% and less than 100 wt% of a polylactic acid (PLA) resin, based on the total weight of the composition, and a polylactic acid (PLA) resin vaporization accelerator for promoting vaporization of a polylactic acid (PLA) resin, and the degree of vaporization (V10w) obtained by measuring the cumulative amount of carbon dioxide (CO2) generated after 10 weeks at 30 DEG C is 50% or more. The polylactic acid (PLA) resin vaporization accelerator can significantly accelerate the vaporization of a polylactic acid (PLA) resin having a low vaporization degree at a room temperature of 30 DEG C, thereby improving the biodegradation of the polylactic acid (PLA). Therefore, the composition containing the polylactic acid (PLA) resin vaporization accelerator can be used in various fields, and shows excellent physical properties while effectively protecting the environment.

Description

Technical Field

[0001] The present invention relates to a vaporization accelerator and a composition containing the vaporization accelerator. The vaporization accelerator accelerates the vaporization of polylactic acid resin. Background Art

[0002] Currently commercialized general-purpose plastics have excellent physical properties and are experiencing increasing demand due to stable supply and prices. However, the problem of handling waste plastics runs through the entire life cycle. Since they do not decompose under natural conditions such as oceans and soil, they are becoming a factor causing serious environmental pollution problems.

[0003] In order to solve these environmental pollution problems, people have actively carried out research on biodegradable plastics in recent years.

[0004] Biodegradable plastics refer to materials that are decomposed into low molecular weight substances by microorganisms existing in nature and ultimately decomposed into water and carbon dioxide, or water and methane gas.

[0005] Polylactic acid resin (commonly used as such biodegradable plastic) is a biodegradable thermoplastic polyester that has great potential to replace traditional petrochemical polymers. It is by far the most studied recyclable polymer material, and its uses are being actively developed.

[0006] Although polylactic acid resin has the characteristics of being able to quickly decompose and regenerate carbon dioxide (CO2) under specific composting conditions, the specific composting conditions required for the decomposition of polylactic acid resin and the generation of carbon dioxide are very strict.

[0007] Specifically, polylactic acid resin decomposes naturally in the soil under high temperature of 50°C or higher and high humidity of about 40% in the soil with numerous microorganisms, and finally generates carbon dioxide. The problem is that it is difficult to biodegrade at room temperature and takes a long time to decompose under natural conditions such as the ocean or soil.

[0008] To solve this problem, artificial biodegradation environments can be created; however, maintaining specific composting (biodegradation) conditions requires high costs and sufficient oxygen supply. Therefore, there are still great limitations in improving the decomposition rate of polylactic acid resin.

[0009] [Prior art literature]

[0010] [Patent Document]

[0011] (Patent Document 1) Korean Patent Publication No. 2014-0112200. Summary of the invention

[0012] Technical issues

[0013] The present invention is intended to solve the problems of the prior art discussed above.

[0014] The present invention aims to provide a vaporization accelerator for polylactic acid (PLA) resin and a composition comprising the vaporization accelerator, wherein the vaporization accelerator increases the vaporization degree of polylactic acid (PLA) resin having a low vaporization degree at room temperature of 30° C., thereby accelerating the biodegradation effect (speed) of the polylactic acid (PLA) resin even at room temperature.

[0015] Solution to the problem

[0016] According to one aspect of the present invention, there is provided a composition comprising a polylactic acid (PLA) resin in a range of 10 wt % to less than 100 wt % based on the total weight of the composition, wherein when the cumulative amount of carbon dioxide (CO2) generated within 10 weeks at 30° C. is measured according to ISO 14855, the vaporization degree (V) represented by the following equation 1 is 10w ) is 50% or more:

[0017] [Equation 1]

[0018]

[0019] In equation 1, (CO2) S is the cumulative amount (g) of carbon dioxide (CO2) produced in the test container containing the compost and the sample, the amount of the sample being 14.3% by weight based on the total dry weight of the sample and the compost, (CO2) B is the cumulative amount of carbon dioxide (CO2) produced in the inoculated container containing only compost (g), (CO2) THV is the theoretical cumulative amount of carbon dioxide (CO2) produced in the test container and is expressed by the following equation 2,

[0020] [Equation 2]

[0021]

[0022] In Equation 2, Cw is the mass (g) of organic carbon contained in the sample.

[0023] In one embodiment, the composition may further include a vaporization accelerator for the polylactic acid (PLA) resin.

[0024] In another embodiment, a weight ratio of the polylactic acid (PLA) resin to the vaporization accelerator for the polylactic acid (PLA) resin may be 10:90 to 90:10.

[0025] In another embodiment, the degree of improvement in vaporization promotion (ΔVID) of the composition represented by the following equation 3 10W) can be 1% or greater:

[0026] [Equation 3]

[0027] ΔVID 10W (%) = V 10w –V THV10w

[0028] In Equation 3, V 10w As defined above, V THV10w It is expressed by the following equation 4,

[0029] [Equation 4]

[0030]

[0031] In Equation 4, x is the weight percentage of the polylactic acid (PLA) resin contained in the composition based on the total weight of the composition.

[0032] In another embodiment, the vaporization accelerator for polylactic acid (PLA) resin may satisfy at least one of the following characteristics: a glass transition temperature (Tg) of -45°C to 80°C, a crystallization temperature (Tc) of 60°C to 120°C, and a melting temperature (Tm) of 100°C to 170°C.

[0033] In another embodiment, a vaporization accelerator for a polylactic acid (PLA) resin may include a resin including a repeating unit derived from a 3-hydroxybutyrate (3-HB) monomer and a repeating unit derived from a 4-hydroxybutyrate (4-HB) monomer.

[0034] In another embodiment, the vaporization accelerator for the polylactic acid (PLA) resin may include repeating units derived from 4-hydroxybutyrate (4-HB) monomers in an amount ranging from 1 mol % to 80 mol %, based on the total moles of repeating units derived from 3-hydroxybutyrate (3-HB) monomers and repeating units derived from 4-hydroxybutyrate (4-HB) monomers.

[0035] According to another aspect of the present invention, a vaporization accelerator for polylactic acid (PLA) resin is provided, comprising the following resin: the resin comprises repeating units derived from 3-hydroxybutyrate (3-HB) monomers and repeating units derived from 4-hydroxybutyrate (4-HB) monomers.

[0036] In one embodiment, the molar ratio of the repeating units derived from the 3-hydroxybutyrate (3-HB) monomer to the repeating units derived from the 4-hydroxybutyrate (4-HB) monomer may be 40:60 to 99:1.

[0037] Advantageous Effects of the Invention

[0038] The composition according to an embodiment of the present invention includes a polylactic acid (PLA) resin having a low degree of vaporization at room temperature of 30° C., wherein the degree of vaporization is high (at a specific level or higher) when the cumulative amount of carbon dioxide (CO 2 ) generated within 10 weeks is measured, thereby achieving excellent biodegradation effect at room temperature.

[0039] In addition, the vaporization accelerator for polylactic acid (PLA) resin can significantly accelerate the vaporization of polylactic acid (PLA) resin (the vaporization degree of which is low at room temperature of 30° C.).

[0040] Therefore, the composition and the vaporization accelerator for polylactic acid (PLA) resin can be used in various fields to effectively protect the environment and have excellent physical properties. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 To show the vaporization degree (V 10w ) over time. DETAILED DESCRIPTION

[0042] Best Mode for Carrying Out the Invention

[0043] Hereinafter, the present invention will be described in detail with reference to the embodiments. Herein, the embodiments are not limited to those described below. On the contrary, they can be modified into various forms as long as the gist of the invention is not changed.

[0044] Throughout the present specification, when a part is referred to as “comprising” an element, it should be understood that other elements may be included, rather than being excluded, unless explicitly stated otherwise.

[0045] Furthermore, unless otherwise indicated, all numbers expressing physical properties, dimensions, and so forth, of elements used herein are to be understood as being modified by the term "about."

[0046] The present invention relates to a composition (a vaporizable composition or a biodegradable composition) and a vaporization accelerator for polylactic acid resin contained in the composition, wherein the vaporization degree (V) calculated by applying the cumulative amount of carbon dioxide (CO2) generated under aerobic composting conditions is 10w ) is controlled within a specific range or higher, so that even if the composition contains a polylactic acid (PLA) resin that is difficult to biodegrade at room temperature (e.g., 25±5°C), it can be easily biodegraded at room temperature (e.g., 25±5°C), which will be described in detail as follows.

[0047] [Composition]

[0048] The composition according to an embodiment of the present invention comprises a polylactic acid (PLA) resin in a range of 10 wt % to less than 100 wt % based on the total weight of the composition, wherein when the cumulative amount of carbon dioxide (CO2) generated within 10 weeks at 30° C. is measured according to ISO 14855, the vaporization degree (V) represented by the following equation 1 is 10w ) is 50% or more:

[0049] [Equation 1]

[0050]

[0051] In equation 1, (CO2) S is the cumulative amount (g) of carbon dioxide (CO2) produced in a test container containing compost and a sample (composition sample), the amount of the sample being 14.3% by weight based on the total dry weight of the sample and compost, (CO2) B is the cumulative amount of carbon dioxide (CO2) produced in the inoculated container containing only compost (g), (CO2) THV is the theoretical cumulative amount of carbon dioxide (CO2) produced in the test container (a+b containing compost (a) and sample (b), wherein the amount of sample (b) is 14.3 wt% of the total dry weight of the sample and the compost) and is represented by the following equation 2,

[0052] [Equation 2]

[0053]

[0054] In Equation 2, Cw is the mass (g) of organic carbon (carbon element) contained in the sample (the amount of the sample is 14.3% by weight of the total weight (x+y) of the dry weight of the sample (x) and the dry weight of the compost (y)). Specifically, Cw refers to the content (g) of carbon element measured when the sample is subjected to elemental analysis.

[0055] For measuring (CO2) S and (CO2) B The weight of the compost can be the same. In addition, the dry weight of the compost can be calculated by loss on drying (LOD), which is a thermogravimetric measurement of moisture. That is, the difference in weight loss is measured as the compost dries, and the dry weight can be calculated by moisture analysis using a drying oven or a halogen moisture analyzer (HMA).

[0056] Vaporization degree (V 10w ) is the value measured when the composition is decomposed into low molecular weight substances and finally completely decomposed into carbon dioxide and vaporized, rather than the degree of biodegradation of the composition into small pieces or small molecules (biodegradation effect).

[0057] Specifically, the vaporization degree (V10w ) is a value obtained by measuring the cumulative amount of carbon dioxide (CO2) generated, which is a final decomposition product of the composition, according to ISO 14855 notification regulations (specifically, aerobic biodegradability evaluation method of ISO14855-1), and applying the measured cumulative amount of carbon dioxide (CO2) to equations 1 and 2, which can be used as an indicator of the degree of biodegradation of the composition at room temperature of 30°C.

[0058] The composition according to the embodiment of the present invention may further include a vaporization accelerator for polylactic acid (PLA) resin. Specifically, the vaporization degree (V) of the composition further including the vaporization accelerator for polylactic acid (PLA) resin represented by equation 1 is 10w ) may be 50% or more. More specifically, the vaporization degree (V 10w ) can be used as an indicator of the biodegradation degree of a composition comprising a polylactic acid (PLA) resin and a vaporization accelerator for the polylactic acid (PLA) resin.

[0059] That is, the vaporization degree (V 10w ) may be a value obtained by the following procedure: as an evaluation group, a composition sample comprising a polylactic acid (PLA) resin and a vaporization accelerator for a polylactic acid (PLA) resin at a specific content ratio is mixed with compost and placed in a test container, and then the cumulative amount (g) of carbon dioxide (CO2) generated by the composition sample is measured under aerobic composting conditions at 30°C for 10 weeks using a measuring and evaluating device (respirometer equipment of ECHO) S ); as a control group, under the same conditions as the evaluation group, the cumulative amount of carbon dioxide (CO2) produced in the inoculated container containing only compost and no composition sample (g) ((CO2) B ); Measurement (CO2) S and (CO2) B (the cumulative amount (g) of carbon dioxide (CO2) produced by the evaluation group and the control group, respectively); then divided by the theoretical cumulative amount (g) of carbon dioxide (CO2) produced expressed by equation 2 ((CO2) THV ) and convert it into a percentage.

[0060] The composition according to an embodiment of the present invention includes a polylactic acid (PLA) resin and has a vaporization degree (V) of a specific level or higher when measuring the cumulative amount of carbon dioxide (CO2) generated within 10 weeks. 10w ); therefore, even if it contains a polylactic acid (PLA) resin having a low vaporization degree, it can produce an excellent biodegradation effect under aerobic composting conditions at room temperature of 30° C. The pressure condition in the aerobic composting condition may be normal pressure.

[0061] Specifically, the vaporization degree (V 10w ) can be, for example, 50.1% or more, 50.2% or more, 50.4% or more, 55% or more, 60% or more, 63% or more, 65% or more, 70% or more, 72% or more, or 75% or more.

[0062] At the same time, (CO2) in Equation 1 S It may be, for example, 35 g or more, 40 g or more, 45 g or more, 50 g or more, 55 g or more, or 60 g or more.

[0063] In equation 1 (CO2) S and (CO2) B The difference between refers to the actual cumulative amount of carbon dioxide (CO2) produced by the sample (composition sample) itself and can be, for example, 5g or more, 10g or more, 10g to 60g, 15g to 50g, or 15g to 40g.

[0064] (CO2) in Equation 1 THV It refers to the theoretical maximum cumulative amount (g) of carbon dioxide (CO2) generated when the sample (composition sample) is completely oxidized in a test container containing compost and the sample (when 100% of the organic carbon contained in the sample is converted into carbon dioxide (CO2)), which can be expressed by Equation 2. That is, (CO2) THV It can be the product of the mass of organic carbon (carbon atoms) contained in the sample (Cw) and the ratio (44 / 12) of the molecular weight of carbon dioxide (44) and the atomic weight of carbon atoms (12). (CO2) THV It may be, for example, 10 g or more, 15 g or more, 20 g or more, 20 g to 60 g, 25 g to 50 g, or 30 g to 45 g.

[0065] Meanwhile, the degree of improvement in vaporization promotion (ΔVID 10W ) can be 1% or greater:

[0066] [Equation 3]

[0067] ΔVID 10W (%) = V 10w –V THV10w

[0068] In Equation 3, V 10w As defined above, V THV10w It is expressed by the following equation 4,

[0069] [Equation 4]

[0070]

[0071] In Equation 4, x is the weight percentage of the polylactic acid (PLA) resin contained in the composition based on the total weight of the composition.

[0072] In equation 4, 3.6% refers to the cumulative amount of carbon dioxide (CO2) generated at 30°C for 10 weeks according to ISO 14855 for a composition consisting of 100 wt% of a polylactic acid (PLA) resin (composition having only a PLA resin), and the vaporization degree (V 10w ), 9.5% refers to the cumulative amount of carbon dioxide (CO2) generated at 30°C for 10 weeks according to ISO14855 for a composition consisting of 100% by weight of a vaporization accelerator for a polylactic acid (PLA) resin (a composition having only a vaporization accelerator for a polylactic acid (PLA) resin), and the vaporization degree (V) calculated by equation 1 10w ).

[0073] The improvement in vaporization promotion (ΔVID 10W ) is the vaporization degree (V 10w ) minus the theoretical vaporization degree (V THV10w )The value obtained (V 10w –V THV10w ), which can be used as an indicator of the degree to which the vaporization of the polylactic acid (PLA) resin is promoted by the vaporization accelerator for the polylactic acid (PLA) resin.

[0074] The improvement in vaporization promotion (ΔVID 10W ) can be, for example, 2% or greater, 3% or greater, 5% or greater, 10% or greater, 15% or greater, 20% or greater, 22% or greater, 23% or greater, 24% or greater, 25% or greater, 26% or greater, 28% or greater, or 30% or greater.

[0075] This improvement in vaporization promotion (ΔVID 10W ) can vary according to the content or physical properties of the polylactic acid (PLA) resin contained in the composition, and can also vary according to the content, components or physical properties of the vaporization accelerator for the polylactic acid (PLA) resin contained in the composition.

[0076] Specifically, when the content ratio (weight ratio) of the polylactic acid (PLA) resin and the vaporization accelerator for the polylactic acid (PLA) resin contained in the composition according to an embodiment of the present invention is 50:50, the degree of improvement in vaporization promotion (ΔVID 10W) can be, for example, 25% or greater, 26% or greater, 27% or greater, or 28% or greater.

[0077] In addition, when the content ratio (weight ratio) of the polylactic acid (PLA) resin to the vaporization accelerator for the polylactic acid (PLA) resin is 75:25, the degree of improvement in vaporization accelerator (ΔVID 10W ) can be, for example, 20% or greater, 22% or greater, 23% or greater, or 24% or greater.

[0078] Meanwhile, in Equation 3, the theoretical vaporization degree (V THV10w ) can vary according to the content (weight) of the polylactic acid (PLA) resin and the vaporization accelerator for the polylactic acid (PLA) resin contained in the composition. Specifically, the vaporization degree (V THV10w ) can be, for example, 10% or more, 15% or more, 20% or more, 20% to 60%, 25% to 55%, or 25% to 50%.

[0079] More specifically, when the content ratio (weight ratio) of the polylactic acid (PLA) resin and the vaporization accelerator for the polylactic acid (PLA) resin contained in the composition according to an embodiment of the present invention is 50:50, the vaporization degree (V THV10w ) can be, for example, 20% or more, 30% or more, 40% or more, 20% to 60%, 30% to 55%, or 35% to 55%.

[0080] In addition, when the content ratio (weight ratio) of the polylactic acid (PLA) resin to the vaporization accelerator for the polylactic acid (PLA) resin is 75:25, the vaporization degree (V THV10w ) can be, for example, 10% or more, 15% or more, 20% or more, 20% to 60%, 20% to 50%, or 20% to 40%.

[0081] When the composition according to the present invention is compared with cellulose (a representative standard biodegradable material) in terms of vaporization degree, its vaporization degree (V 10w ) can be equal to or higher than the vaporization degree of cellulose.

[0082] Specifically, the composition according to an embodiment of the present invention includes a polylactic acid (PLA) resin having a low vaporization degree at room temperature of 30° C., wherein the vaporization degree (V 10w ) is higher than a certain level or higher (e.g., 50% or higher), thereby producing an excellent biodegradation effect at room temperature.

[0083] Therefore, the composition according to an embodiment of the present invention can be used in various fields to effectively protect the environment and has excellent physical properties.

[0084] Hereinafter, each component of the composition according to an embodiment of the present invention will be described in detail.

[0085] Polylactic acid (PLA) resin

[0086] The composition according to an embodiment of the present invention may include 10 wt % to less than 100 wt % of a polylactic acid (PLA) resin based on the total weight of the composition.

[0087] Since polylactic acid (PLA) resin is biomass-based, unlike petroleum-based resins, it can be used as a recyclable resource and can be degraded by moisture and microorganisms when landfilled, having environmentally friendly characteristics.

[0088] The polylactic acid (PLA) resin may be obtained from L-lactic acid, D-lactic acid, D,L-lactic acid or a combination thereof. Specifically, the polylactic acid (PLA) resin may be a random copolymer of L-lactic acid and D-lactic acid.

[0089] The weight average molecular weight (Mw) of the polylactic acid (PLA) resin may be 10,000 g / mol to 1,000,000 g / mol, 30,000 g / mol to 500,000 g / mol, 100,000 g / mol to 300,000 g / mol, or 100,000 g / mol to 200,000 g / mol. The weight average molecular weight (Mw) may be measured by gel permeation chromatography (GPC).

[0090] The melting temperature (Tm) of the polylactic acid (PLA) resin may be 100°C to 300°C, 110°C to 280°C, 120°C to 250°C, or 120°C to 200°C.

[0091] The glass transition temperature (Tg) of the polylactic acid (PLA) resin may be 30°C to 100°C, 30°C to 80°C, 40°C to 80°C, or 45°C to 70°C.

[0092] With the gross weight of composition, the composition according to an embodiment of the present invention can include 10 % by weight to be less than 100 % by weight polylactic acid (PLA) resin. Specifically, with the gross weight of composition, it is 10 % by weight or more, 20 % by weight or more, 30 % by weight or more, 50 % by weight or more or 70 % by weight or more that the composition can include an amount, and it is less than 100 % by weight, 98 % by weight or less, 95 % by weight or less, 90 % by weight or less, 85 % by weight or less, 80 % by weight or less polylactic acid (PLA) resin. For example, with the gross weight of composition, it is 10 % by weight to be less than 100 % by weight, 10 % by weight to 95 % by weight, 30 % by weight to 95 % by weight, 40 % by weight to 90 % by weight or 50 % by weight to 80 % by weight polylactic acid (PLA) resin that the composition can include an amount.

[0093] If the content of the polylactic acid (PLA) resin contained in the composition according to the embodiment of the invention is 100 wt %, the vaporization degree at room temperature of 30° C. is very low; therefore, it may be difficult to achieve the desired biodegradation effect. Specifically, when the cumulative amount of carbon dioxide (CO2) generated by the composition composed of 100 wt % of the polylactic acid (PLA) resin at 30° C. for 10 weeks is measured according to the ISO 14855 standard, the vaporization degree (V) calculated by Equation 1 is 10w ) can be, for example, 5% or less, 4.5% or less, 4.0% or less, 3.6% or less, 3.0% or less, or 2.7% or less, thereby producing a significantly minimum biodegradation effect at room temperature.

[0094] Therefore, the composition according to an embodiment of the present invention further includes a vaporization accelerator for polylactic acid (PLA) resin described below to accelerate the vaporization of polylactic acid (PLA) resin having a low vaporization degree at room temperature, thereby further enhancing the biodegradation effect.

[0095] Vaporization accelerator for polylactic acid (PLA) resin

[0096] The composition according to an embodiment of the present invention may further include a vaporization accelerator for the polylactic acid (PLA) resin.

[0097] The vaporization accelerator for polylactic acid (PLA) resin may be used as an accelerator for accelerating the vaporization of polylactic acid (PLA) resin having a low vaporization degree at room temperature of 30°C.

[0098] With the gross weight of composition, the composition according to the embodiment of the present invention can include amount to be greater than 0 % by weight, 5 % by weight or more, 10 % by weight or more, 15 % by weight or more, 20 % by weight or more, 30 % by weight or more, or 40 % by weight or more, and less than 100 % by weight, 90 % by weight or less, 80 % by weight or less, 70 % by weight or less, 60 % by weight or less, or 50 % by weight or less vaporization accelerator for polylactic acid (PLA) resin.For example, with the gross weight of composition, composition can include amount to be greater than 0 % by weight to less than 100 % by weight, greater than 0 % by weight to 90 % by weight, greater than 0 % by weight to 70 % by weight, 5 % by weight to 90 % by weight, 5 % by weight to 80 % by weight, 10 % by weight to 70 % by weight, 20 % by weight to 60 % by weight, 25 % by weight to 60 % by weight, or 30 % by weight to 50 % by weight vaporization accelerator for polylactic acid (PLA) resin.

[0099] When the content of the vaporization accelerator for the polylactic acid (PLA) resin satisfies the above range, the vaporization of the polylactic acid (PLA) resin is effectively accelerated, and thus the composition according to an embodiment of the present invention can produce an excellent biodegradation effect at a room temperature of 30° C. even if it contains 10 wt % or more, 30 wt % or more, 50 wt % or more, or 70 wt % or more of the polylactic acid (PLA) resin.

[0100] The vaporization accelerator for polylactic acid (PLA) resin may include polyhydroxyalkanoate (hereinafter referred to as "PHA") resin. Since PHA resin has specific physical properties (e.g., specific crystal structure, components derived from specific monomers, etc.), it can effectively promote the vaporization of polylactic acid (PLA) resin.

[0101] PHA resins have similar physical properties to petroleum-based synthetic resins such as polybutylene adipate / terephthalate (PBAT), polybutylene succinate (PBS), polybutylene succinate terephthalate (PBST), and polybutylene succinate adipate (PBSA), and are fully biodegradable and have excellent biocompatibility.

[0102] Specifically, PHA resin is a natural thermoplastic polyester polymer that accumulates in microbial cells. Because it is biodegradable, it can be composted and eventually decomposed into carbon dioxide, water, and organic waste without generating toxic waste. In particular, PHA resin is biodegradable in soil and oceans. Therefore, when a composition according to an embodiment of the present invention includes a PHA resin, it is biodegradable under any environmental conditions such as soil and oceans, and is environmentally friendly. For example, when the cumulative amount of carbon dioxide (CO2) generated by a composition consisting of 100 wt.% of a PHA resin at 30°C for 10 weeks is measured according to the ISO 14855 standard, the vaporization degree (V) calculated by equation 1 is 10w ) may be, for example, 90% or more, 91% or more, 91.5% or more, or 92% or more, thereby producing a remarkably excellent biodegradation effect at room temperature.

[0103] PHA resins can be formed by enzyme-catalyzed polymerization of one or more monomers in living cells.

[0104] Specifically, the PHA resin can be a copolymerized polyhydroxyalkanoate resin (hereinafter referred to as "PHA copolymer"), more specifically, a copolymer in which repeating units derived from two or more different monomers are randomly distributed in the polymer chain. In addition, the PHA resin can also include isomers. For example, the PHA resin can include structural isomers, enantiomers, or geometric isomers. Specifically, the PHA resin can include structural isomers.

[0105] Examples of monomers that can be used to prepare PHA specifically include: 2-hydroxybutyrate, lactic acid, glycolic acid, 3-hydroxybutyrate (hereinafter referred to as "3-HB"), 3-hydroxypropionate (hereinafter referred to as "3-HP"), 3-hydroxyvalerate (hereinafter referred to as "3-HV"), 3-hydroxyhexanoate (hereinafter referred to as "3-HH"), 3-hydroxyheptanoate (hereinafter referred to as "3-HHep"), 3-hydroxyoctanoate (hereinafter referred to as "3-HO"), 3-hydroxynonanoate (hereinafter referred to as "3-HN"), 3-hydroxydecanoate (hereinafter referred to as "3-HD"), 3-hydroxydodecanoate (hereinafter referred to as "3-HDd"), 4-hydroxybutyrate (hereinafter referred to as "4-HB"), 4-hydroxyvalerate (hereinafter referred to as "4-HV"), 5-hydroxyvalerate (hereinafter referred to as "5-HV"), and 6-hydroxyhexanoate (hereinafter referred to as "6-HH"). The PHA resin may include repeating units derived from one or more monomers selected from the above monomers.

[0106] Specifically, the PHA resin may include repeating units (at least one repeating unit) derived from one or more monomers selected from 3-HB, 4-HB, 3-HP, 3-HV, 3-HH, 4-HV, 5-HV, and 6-HH.

[0107] More specifically, the PHA resin may include repeating units derived from 4-HB monomers. That is, the PHA resin may be a PHA copolymer including repeating units derived from 4-HB monomers. The PHA resin may be a PHA copolymer including repeating units derived from 4-HB monomers and further including repeating units derived from monomers other than the 4-HB monomer, or further including repeating units derived from two, three, four, five, six or more monomers different from each other (2 or more repeating units different from each other).

[0108] The vaporization promoter for polylactic acid (PLA) resin according to an embodiment of the present invention may include the following resin (PHA copolymer): the resin (PHA copolymer) includes a repeating unit derived from a 4-HB monomer, and at the same time includes a repeating unit (at least one repeating unit) derived from at least one monomer selected from 3-HB monomer, 3-HP monomer, 3-HV monomer, 3-HH monomer, 4-HV monomer, 5-HV monomer and 6-HH monomer. More specifically, the vaporization promoter for polylactic acid (PLA) resin may include the following resin (PHA copolymer): the resin (PHA copolymer) includes a repeating unit derived from a 3-HB monomer (hereinafter referred to as "3-HB repeating unit") and a repeating unit derived from a 4-HB monomer (hereinafter referred to as "4-HB repeating unit"). For example, it may include a poly-3-hydroxybutyrate-to-4-hydroxybutyrate (hereinafter referred to as "P3-HB-to-4-HB") copolymer.

[0109] According to an embodiment of the present invention, in order to promote vaporization of polylactic acid (PLA) resin while improving biodegradability of the composition in soil and ocean, it may be important to control the content ratio of 3-HB repeating units and 4-HB repeating units contained in the PHA resin.

[0110] For example, in the PHA resin including 3-HB repeating units and 4-HB repeating units, the molar ratio of the 3-HB repeating unit to the 4-HB repeating unit may be 20:80 to 99:1, 30:70 to 99:1, 40:60 to 99:1, 50:50 to 95:5, 50:50 to 94:6, 50:50 to 92:8, 55:45 to 92:8, or 55:45 to 90: 10. When the molar ratio of the 3-HB repeating unit to the 4-HB repeating unit satisfies the above range, it may be more conducive to achieving the desired biodegradation effect of the present invention.

[0111] Specifically, based on the total moles (mole number) of 3-HB repeating units and 4-HB repeating units, the content of 4-HB repeating units can be 1 mol% to 80 mol%, 2 mol% to 70 mol%, 3 mol% to 60 mol%, 5 mol% to 50 mol%, 8 mol% to 45 mol%, or 10 mol% to 45 mol%.

[0112] In addition, in a PHA resin including at least one 4-HB repeating unit, the crystallinity of the PHA resin can be adjusted according to the content of the 4-HB repeating unit. That is, the PHA resin can be a PHA copolymer with controllable crystallinity. Specifically, according to the content of the 4-HB repeating unit, the PHA resin can be divided into a semi-crystalline PHA (scPHA) copolymer or an amorphous PHA (aPHA) copolymer.

[0113] The PHA resin with adjusted crystallinity may be a resin with adjusted crystallinity and amorphism as the irregularity of its molecular structure increases. Specifically, the crystallinity and amorphism may be determined by the type of monomer, the ratio of repeating units derived from the monomer, or the type and / or content of isomers.

[0114] Specifically, the PHA resin may be an amorphous PHA (aPHA) copolymer including a 4-HB repeating unit. Since the vaporization accelerator for the polylactic acid (PLA) resin includes such an amorphous PHA (aPHA) copolymer, the vaporization of the polylactic acid (PLA) resin may be more effectively promoted.

[0115] Meanwhile, the glass transition temperature (Tg) of the PHA resin may be, for example, -45°C to 80°C, -35°C to 80°C, -30°C to 80°C, -25°C to 75°C, -20°C to 70°C, -35°C to 5°C, -25°C to 5°C, -35°C to 0°C, -25°C to 0°C, -30°C to -10°C, -35°C to -15°C, -35°C to -20°C, -20°C to 0°C, -15°C to 0°C, or -15°C to -5°C.

[0116] For example, the crystallization temperature (Tc) of the PHA resin may not be measured, or the crystallization temperature (Tc) of the PHA resin may be, for example, 60°C to 120°C, 70°C to 120°C, 75°C to 120°C, 75°C to 115°C, 75°C to 110°C, or 90°C to 110°C.

[0117] For example, the melting temperature (Tm) of the PHA resin may not be measured, or the melting temperature (Tm) of the PHA resin may be, for example, 100°C to 170°C, 105°C to 160°C, 110°C to 150°C, 115°C to 155°C, or 120°C to 140°C.

[0118] The weight average molecular weight (Mw) of the PHA resin may be, for example, 10,000 g / mol to 1,200,000 g / mol. Specifically, the weight average molecular weight of the PHA resin may be 50,000 g / mol to 1,200,000 g / mol, 100,000 g / mol to 1,200,000 g / mol, 50,000 g / mol to 1,000,000 g / mol, 100,000 g / mol to 1,000,000 g / mol, 200,000 g / mol to 1,200,000 g / mol, 250,000 g / mol to 1,150,000 g / mol, 300,000 g / mol to 1,100,000 g / mol, 350,000 g / mol to 1,000,000 g / mol, 350,000 g / mol to 950,000 g / mol, 100,000 g / mol to 900,000 g / mol. , 200,000 g / mol to 800,000 g / mol, 200,000 g / mol to 700,000 g / mol, 250,000 g / mol to 650,000 g / mol, 200,000 g / mol to 400,000 g / mol, 300,000 g / mol to 800,000 g / mol, 300,000 g / mol to 600 ,000 g / mole, 500,000 g / mole to 1,200,000 g / mole, 500,000 g / mole to 1,000,000 g / mole, 550,000 g / mole to 1,050,000 g / mole, 550,000 g / mole to 900,000 g / mole, or 600,000 g / mole to 900,000 g / mole.

[0119] Meanwhile, the composition according to the embodiment of the invention may include polylactic acid (PLA) resin and a vaporization promoter for polylactic acid (PLA) resin in a specific content ratio. Specifically, the content ratio (weight ratio) of polylactic acid (PLA) resin to the vaporization promoter for polylactic acid (PLA) resin may be, for example, 10:90 to 90:10, 15:85 to 90:10, 20:80 to 90:10, 25:75 to 90:10, 30:70 to 90:10, 40:60 to 90:10, 45:55 to 85:15, 50:50 to 85:15, 50:50 to 80:20, 50:50 to 75:25, or 50:50 to 70:30. When the content ratio (weight ratio) of the polylactic acid (PLA) resin to the vaporization accelerator for the polylactic acid (PLA) resin satisfies the above range, vaporization of the polylactic acid (PLA) resin can be significantly accelerated.

[0120] additive

[0121] The composition according to an embodiment of the present invention may further include at least one additive selected from the group consisting of an antioxidant, a compatibilizer, a weighting agent, a nucleating agent, a melt strength enhancer, and a slip agent.

[0122] The content of the additive can be adjusted according to the expected effect and purpose of the composition. Based on the gross weight of the composition, the content of the additive can be 0.1 wt % or more, 0.5 wt % or more, 1 wt % or more, 1.5 wt % or more, or 2 wt % or more, and 30 wt % or less, 28 wt % or less, 25 wt % or less, 20 wt % or less, 15 wt % or less, 10 wt % or less, 8 wt % or less, or 5 wt % or less.

[0123] The additives may be conventionally known additives depending on the desired effects and uses.

[0124] Mode for Carrying Out the Invention

[0125] Hereinafter, the present invention will be described in more detail with reference to the following examples. However, the following examples are intended to illustrate the present invention, and the scope of the embodiments of the present invention is not limited thereto.

[0126] <Example>

[0127] Example 1

[0128] As shown in Table 1 below, polylactic acid (PLA) resin (NatureWorks, 4032D) and polyhydroxyalkanoate (PHA) resin (P3-HB-co-4-HB, aPHA) (CJ CheilJedang, South Korea) as a vaporization accelerator for polylactic acid (PLA) resin were mixed in a weight ratio of 50:50 to prepare a composition.

[0129] Example 2

[0130] As shown in Table 1 below, polylactic acid (PLA) resin (NatureWorks, 4032D) and polyhydroxyalkanoate (PHA) resin (P3-HB-co-4-HB, aPHA) (CJ CheilJedang, South Korea) as a vaporization accelerator for polylactic acid (PLA) resin were mixed in a weight ratio of 75:25 to prepare a composition.

[0131] Example 3

[0132] As shown in Table 1 below, polylactic acid (PLA) resin (Nature Works, 2003D) and polyhydroxyalkanoate (PHA) resin (P3-HB-co-4-HB, aPHA) (CJ Cheil Jedang, South Korea) as a vaporization accelerator for polylactic acid (PLA) resin were mixed in a weight ratio of 50:50 to prepare a composition.

[0133] Example 4

[0134] As shown in Table 1 below, polylactic acid (PLA) resin (Nature Works, 2003D) and polyhydroxyalkanoate (PHA) resin (P3-HB-co-4-HB, aPHA) (CJ Cheil Jedang, South Korea) as a vaporization accelerator for polylactic acid (PLA) resin were mixed in a weight ratio of 70:30 to prepare a composition.

[0135] Example 5

[0136] As shown in Table 1 below, polylactic acid (PLA) resin (Nature Works, 2003D) and polyhydroxyalkanoate (PHA) resin (P3-HB-co-4-HB, aPHA) (CJ Cheil Jedang, South Korea) to be used as a vaporization accelerator for polylactic acid (PLA) resin were mixed in a weight ratio of 60:40 to prepare a composition.

[0137] Comparative Example 1

[0138] As shown in Table 1 below, a composition consisting of 100 wt % of a polylactic acid (PLA) resin (NatureWorks, 4032D) was prepared.

[0139] Comparative Example 2

[0140] As shown in Table 1 below, a composition consisting of 100 wt % of a polyhydroxyalkanoate (PHA) resin (P3-HB-co-4-HB, scPHA) (CJ Cheil Jedang, Korea) as a vaporization accelerator for a polylactic acid (PLA) resin was prepared.

[0141] Comparative Example 3

[0142] As shown in Table 1 below, polylactic acid (PLA) resin (NatureWorks, 4032D) and poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) (Tianan, China) as a vaporization accelerator for the polylactic acid (PLA) resin were mixed in a weight ratio of 50:50 to prepare a composition.

[0143] Comparative Example 1

[0144] Uses cellulose, a standard biodegradable material.

[0145] The contents and physical properties of the compositions respectively obtained in Examples and Comparative Examples are summarized in the following Table 1. Here, in the following Table 1, Tg and Tm of Comparative Example 1 are Tg and Tm values ​​measured for the PLA resin used in Comparative Example 1.

[0146] [Table 1]

[0147]

[0148] Evaluation example

[0149] Evaluation Example 1: Vaporization Degree

[0150] According to ISO 14855, the cumulative amount of carbon dioxide produced under aerobic composting conditions is measured to calculate the degree of vaporization (V 10w ).

[0151] Specifically, as an evaluation group, each composition sample of the embodiment and the comparative example was extracted at 14.3% by weight of the total dry weight of the composition sample and the compost, and a test container containing a mixture obtained by mixing the composition sample with the compost (Abnexo Co., Ltd.) was prepared. In this case, the initial moisture content of the compost was determined by the LOD moisture measurement method using HMA or a drying oven. Additional moisture was added to adjust the final moisture content to 50% to adjust the dry weight. In addition, according to the ISO 14855 notification, a mixture was prepared by uniformly mixing 20g of a dried composition sample (0% moisture content) with 240g of a compost (dry weight: 120g) having a moisture content of 50%, and adjusting the ratio of the sample to the compost to 1:6.

[0152] In addition, as a control group, an inoculated container containing only compost and no composition sample was prepared.

[0153] Then, after 10 weeks at 30°C under normal pressure and aerobic conditions, the carbon dioxide produced in each container was collected using ECHO's respirometer equipment and titrated with an NIR (near infrared sensor) through a system within the device to measure the cumulative amount of carbon dioxide produced in each container.

[0154] The measured cumulative amount of generated carbon dioxide is used to calculate the vaporization degree (V 10w ):

[0155] [Equation 1]

[0156]

[0157] In equation 1, (CO2)S is the cumulative amount (g) of carbon dioxide (CO2) produced in the test container containing the compost and the sample, the amount of the sample being 14.3% by weight based on the total dry weight of the sample and the compost, (CO2) B is the cumulative amount of carbon dioxide (CO2) produced in the inoculated container containing only compost (g), (CO2) THV is the theoretical cumulative amount of carbon dioxide (CO2) produced in the test container and is expressed by the following equation 2:

[0158] [Equation 2]

[0159]

[0160] In Equation 2, Cw is the mass (g) of organic carbon contained in the sample. Specifically, Cw is the content (g) of carbon element contained in the sample.

[0161] Evaluation Example 2: Degree of improvement in vaporization promotion

[0162] In order to measure the degree to which the vaporization accelerator for polylactic acid (PLA) resin promotes the vaporization of polylactic acid (PLA) resin, the improvement degree in vaporization promotion (ΔVID 10W ) were evaluated.

[0163] Specifically, using the vaporization degree (V 10w ) and the theoretical vaporization degree (V THV10w ) to calculate the improvement in vaporization promotion (ΔVID 10W The theoretical vaporization degree (V) is calculated by the following equation 4: THV10w ):

[0164] [Equation 4]

[0165]

[0166] In Equation 4, x is the weight percentage of the polylactic acid (PLA) resin contained in the composition based on the total weight of the composition.

[0167] Tables 2 and 3 below and Figure 1 The results obtained in Evaluation Examples 1 and 2 are summarized.

[0168] [Table 2]

[0169]

[0170] [Table 3]

[0171]

[0172] From the above table 3 and Figure 1It can be seen that when measuring the cumulative amount of carbon dioxide (CO2) generated at 30°C for 10 weeks, the vaporization degree (V 10w ) were all 50% or higher, indicating that they all reached the vaporization level of cellulose, a representative standard biodegradable material. Specifically, compared with the vaporization degree (V ) of 3.6% of Comparative Example 1 using a composition composed of 100 wt % of polylactic acid (PLA) resin, 10w ), the compositions of Examples 1 to 5 have significantly improved vaporization degrees (V 10w ).

[0173] In particular, the vaporization degree (V 10w ), in Examples 1 to 5 using the composition comprising a polylactic acid (PLA) resin and a vaporization accelerator for a polylactic acid (PLA) resin, the degree of improvement in vaporization accelerator (ΔVID 10W ) is significantly increased by 5% or more, specifically 20% or more.

[0174] In particular, in the composition of Example 1 (in which the polylactic acid (PLA) resin and the vaporization accelerator for the polylactic acid (PLA) resin are used in a weight ratio of 50:50), when fully oxidized (100% conversion), the theoretical cumulative amount of carbon dioxide (CO2) generated ((CO2) THV ) is 38.8g. When assuming that the polylactic acid (PLA) resin does not vaporize at room temperature, the cumulative amount of carbon dioxide (CO2) generated by the polylactic acid (PLA) resin is predicted to be 19.4g, which is the above (CO2) THV However, after 10 weeks, the actual amount of carbon dioxide (CO2) produced ((CO2) S –(CO2) B ) is 29.7 g, indicating that the vaporization promoter for polylactic acid (PLA) resin promotes the vaporization of polylactic acid (PLA) resin, that is, produces a vaporization promoting effect. That is, the excess amount of about 10 g (the amount of carbon dioxide (CO2) actually generated ((CO2) S –(CO2) B ) and (CO2) THV The difference between the half of the predicted value) is predicted as the amount of carbon dioxide (CO2) generated from the polylactic acid (PLA) resin whose vaporization is promoted by the vaporization accelerator for the polylactic acid (PLA) resin.

[0175] The above results confirm that the vaporization accelerator used for polylactic acid (PLA) resin not only has a high vaporization degree, but also can significantly accelerate the vaporization of polylactic acid (PLA) resin.

[0176] Meanwhile, in the composition of Comparative Example 3 (in which PHBV as a vaporization promoter for polylactic acid (PLA) resin was mixed with polylactic acid (PLA) resin at a weight ratio of 50:50), no vaporization promoting effect was produced. Therefore, it was confirmed that the PHA resin of the present invention having specific physical properties can particularly promote the vaporization of polylactic acid (PLA) resin.

Claims

1. A composition comprising 10 wt % to less than 100 wt % of a polylactic acid (PLA) resin, based on the total weight of the composition, wherein: When the cumulative amount of carbon dioxide (CO2) generated at 30°C for 10 weeks is measured according to ISO 14855, the vaporization degree (V 10w ) is 50% or higher: [Equation 1] In Equation 1, (CO2) S is the cumulative amount (g) of carbon dioxide (CO2) produced in the test container containing the compost and the sample, the amount of the sample being 14.3% by weight based on the total dry weight of the sample and the compost, (CO2) B is the cumulative amount of carbon dioxide (CO2) produced in the inoculated container containing only compost (g), (CO2) THV is the theoretical cumulative amount of carbon dioxide (CO2) produced in the test container and is expressed by the following equation 2, [Equation 2] In Equation 2, Cw is the mass (g) of organic carbon contained in the sample.

2. The composition according to claim 1, further comprising a vaporization accelerator for polylactic acid (PLA) resin.

3. The composition according to claim 2, wherein The weight ratio of the polylactic acid (PLA) resin to the vaporization accelerator for the polylactic acid (PLA) resin is 10:90 to 90:

10.

4. The composition according to claim 2, wherein The degree of improvement in vaporization promotion (ΔVID) is expressed by the following equation 3. 10W ) is 1% or greater: [Equation 3] ΔVID 10W (%)=V 10w –V THV10w In Equation 3, V 10w As defined in claim 1, V THV10w It is expressed by the following equation 4, [Equation 4] In Equation 4, x is the weight percentage of the polylactic acid (PLA) resin contained in the composition based on the total weight of the composition.

5. The composition according to claim 2, wherein The vaporization accelerator for polylactic acid (PLA) resin satisfies at least one of the following characteristics: The glass transition temperature (Tg) is -45°C to 80°C. a crystallization temperature (Tc) of 60°C to 120°C, and The melting temperature (Tm) is 100°C to 170°C.

6. The composition according to claim 2, wherein The vaporization accelerator for polylactic acid (PLA) resin includes the following resin: the resin includes repeating units derived from 4-hydroxybutyrate (4-HB) monomer; and repeating units derived from at least one monomer selected from 3-hydroxybutyrate (3-HB), 3-hydroxypropionate (3-HP), 3-hydroxyvalerate (3-HV), 3-hydroxyhexanoate (3-HH), 4-hydroxyvalerate (4-HV), 5-hydroxyvalerate (5-HV) and 6-hydroxyhexanoate (6-HH).

7. The composition according to claim 6, wherein A vaporization accelerator for a polylactic acid (PLA) resin includes a resin including a repeating unit derived from a 3-hydroxybutyrate (3-HB) monomer and a repeating unit derived from a 4-hydroxybutyrate (4-HB) monomer.

8. The composition according to claim 7, wherein The vaporization accelerator for the polylactic acid (PLA) resin includes repeating units derived from 4-hydroxybutyrate (4-HB) monomers in an amount ranging from 1 mol % to 80 mol %, based on the total moles of repeating units derived from 3-hydroxybutyrate (3-HB) monomers and repeating units derived from 4-hydroxybutyrate (4-HB) monomers.

9. A vaporization accelerator for polylactic acid (PLA) resin, comprising the following resin: The resin includes repeating units derived from 3-hydroxybutyrate (3-HB) monomers and repeating units derived from 4-hydroxybutyrate (4-HB) monomers.

10. The vaporization accelerator for polylactic acid (PLA) resin according to claim 9, wherein The molar ratio of the repeating units derived from the 3-hydroxybutyrate (3-HB) monomer to the repeating units derived from the 4-hydroxybutyrate (4-HB) monomer is 40:60 to 99:1.

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