Resin composition and biodegradable resin product comprising same

Abstract

The present invention relates to a resin composition and a biodegradable resin product comprising same. The resin composition of the present invention can implement adhesion, mechanical properties and air permeability suitable for a packaging wrap use while maintaining the biodegradability of polybutylene adipate terephthalate.

Description

Resin composition and biodegradable resin molded article containing the same

[0001] Cross-citation with related application(s)

[0002] This application claims the benefit of priority to Korean Patent Application No. 10-2024-0070233, filed May 29, 2024, the entire contents of which are incorporated herein by reference.

[0003]

[0004] The present invention relates to a resin composition and a biodegradable resin molded product comprising the same.

[0005]

[0006] The recent frequency of natural disasters has highlighted the severity of environmental pollution and the resulting climate change as serious issues requiring urgent resolution. Reducing the use of single-use plastics is a practical, everyday action to improve environmental pollution, and many countries are implementing policies to address this issue. As part of these policies, the use of eco-friendly or biodegradable plastics is also being recommended, and research and development are underway on various plastics that can be biodegraded in soil or the ocean.

[0007]

[0008] Meanwhile, plastic films are mostly used in food packaging to prevent spoilage and ensure long-term preservation during distribution. Among these, polyvinyl chloride (PVC) wrap is commonly used in cling films and cling wraps due to its low price and excellent packaging properties. However, PVC has issues such as chlorine gas emissions during disposal / incineration and contamination during recycling. Furthermore, the government is strengthening regulations on the use of PVC wrap to reduce harmful gas emissions and improve the quality of recycled products.

[0009]

[0010] To replace these polyvinyl chloride (PVC) wraps, research is needed to develop functional, stable materials. To meet this demand, polyolefin (primarily LLDPE) wraps have been developed. However, achieving physical properties such as adhesiveness comparable to those of polyvinyl chloride (PVC) is difficult, and the multilayer design typically employed to achieve the required properties makes recycling difficult.

[0011]

[0012] Therefore, there is a need for research on materials that utilize biodegradable materials that can be naturally decomposed in soil or the ocean, and that have the gas barrier properties, mechanical properties, and chemical properties required for the aforementioned food packaging materials.

[0013]

[0014] The present invention aims to provide a resin composition having biodegradable properties while satisfying the adhesiveness, mechanical properties and breathability required of a wrap film.

[0015] In addition, the present invention seeks to provide a biodegradable resin molded product comprising the resin composition.

[0016]

[0017] In order to solve the above problem, the present invention provides a resin composition comprising polybutylene adipate terephthalate (PBAT) and triacetin, wherein the weight average molecular weight of the polybutylene adipate terephthalate is 100,000 to 200,000 g / mol, and wherein the resin composition comprises 1 to 25 parts by weight of triacetin based on 100 parts by weight of the total resin composition.

[0018]

[0019] In one example, the weight average molecular weight of the polybutylene adipate terephthalate may be 130,000 to 190,000 g / mol.

[0020]

[0021] In one example, the polydispersity index (PDI) of the polybutylene adipate terephthalate may be 2.5 or less.

[0022]

[0023] In one example, the melt index (measured at 190° C. under a 2.16 kg load according to ASTM D1238) of the polybutylene adipate terephthalate may be 2.0 to 6.0 g / 10 min.

[0024]

[0025] According to one example, triacetin may be included in an amount of 1 to 20 parts by weight based on 100 parts by weight of the total resin composition.

[0026]

[0027] In addition, the present invention provides a biodegradable resin molded product comprising the resin composition of the present invention.

[0028]

[0029] For example, the modulus value measured according to ASTM D882 may be 30 to 100 MPa.

[0030]

[0031] For example, the adhesion value measured according to ASTM D882 may be 5 to 20 N.

[0032]

[0033] According to an example, the oxygen permeability of the biodegradable resin molded product is 100 to 400 cc / m based on a sheet thickness of 500 to 600 ㎛. 2 ·day·atm may be.

[0034]

[0035] According to an example, the moisture permeability of the biodegradable resin molded product is 50 to 95 g / m based on a sheet thickness of 500 to 600 ㎛. 2 ·It could be day.

[0036]

[0037] The terminology used herein is for the purpose of describing exemplary embodiments only and is not intended to limit the invention.

[0038] Singular expressions include plural expressions unless the context clearly indicates otherwise.

[0039] In this specification, the terms “comprise,” “include,” or “have” are intended to describe a feature, number, step, component, or combination thereof implemented, but do not exclude the possibility of one or more other features, numbers, steps, components, combinations, or additions thereof.

[0040] The present invention is susceptible to various modifications and takes various forms. Specific embodiments are illustrated and described in detail below. However, this does not limit the invention to a specific disclosed form, but rather encompasses all modifications, equivalents, and alternatives falling within the spirit and technical scope of the present invention.

[0041]

[0042] Hereinafter, the present invention will be described in detail.

[0043]

[0044] The present invention provides a resin composition comprising polybutylene adipate terephthalate (PBAT) and triacetin, wherein the weight average molecular weight of the polybutylene adipate terephthalate is 100,000 to 200,000 g / mol, and wherein the resin composition comprises 1 to 25 parts by weight of triacetin based on 100 parts by weight of the total resin composition.

[0045]

[0046] Polyester resins possess superior mechanical and chemical properties and are used in a variety of industrial fields. Among them, polybutylene adipate terephthalate (PBAT), a soft polyester resin, is biodegradable and is attracting attention as a substitute for polyolefin polymers, which are primarily used in food packaging films. However, the adhesiveness and gas barrier properties of PBAT, which are somewhat inadequate for this purpose, pose a challenge for its use alone.

[0047]

[0048] The inventors of the present invention conducted blending research with various additives in order to use polybutylene adipate terephthalate (PBAT), a type of biodegradable resin, as a packaging material wrap, and were able to confirm that when triacetin was used among the additives, it had excellent miscibility with polybutylene adipate terephthalate.

[0049] Specifically, the inventors of the present invention selected a group of substances predicted to have high miscibility with polybutylene adipate terephthalate using the Hansen solubility parameters of polybutylene adipate terephthalate and additives, and then mixed them with polybutylene adipate terephthalate to prepare a resin composition and evaluated the migration of the additives. As a result, it was experimentally confirmed that triacetin had excellent miscibility with polybutylene adipate terephthalate.

[0050] The above triacetin is a compound represented by the following chemical formula 1 and is a triester of glycerol and acetic acid:

[0051] [Chemical Formula 1]

[0052] .

[0053]

[0054] In addition, when the weight average molecular weight of the polybutylene adipate terephthalate is 100,000 to 200,000 g / mol, the resin composition blending triacetin and the polybutylene adipate terephthalate has improved mechanical properties such as modulus, strength, and elongation, and when triacetin is included in an amount of 1 to 25 parts by weight based on a total of 100 parts by weight of the resin composition, the adhesiveness is improved and appropriate oxygen permeability and moisture permeability can be achieved, thereby completing the present invention.

[0055]

[0056] The resin composition of the present invention comprises polybutylene adipate terephthalate having a weight average molecular weight of 100,000 to 200,000 g / mol. When the weight average molecular weight of the polybutylene adipate terephthalate is less than 100,000, extrusion molding is difficult due to low melt viscosity, and when manufacturing a molded product, the modulus, strength, and elongation values ​​may be low, which may cause problems in realizing mechanical properties suitable for the intended use. In addition, when the weight average molecular weight of the polybutylene adipate terephthalate exceeds 200,000 g / mol, the modulus, strength, etc. may increase to a level that makes it inconvenient to use as a food packaging material. Preferably, the weight average molecular weight of the polybutylene adipate terephthalate may be 110,000 g / mol or more, 120,000 g / mol or more, or 130,000 g / mol or more, and 200,000 g / mol or less, or 190,000 g / mol or less.

[0057]

[0058] Meanwhile, the resin composition of the present invention may contain 1 to 25 parts by weight of triacetin based on 100 parts by weight of the total resin composition. If the resin composition contains less than 1 part by weight of triacetin based on 100 parts by weight of the total resin composition, the adhesive improvement effect due to the addition of triacetin may be insufficient, and thus the resin composition may not be suitable for the use of the present invention. In addition, if the resin composition contains more than 25 parts by weight of triacetin based on 100 parts by weight of the total resin composition, migration of triacetin may occur during the production of the blended resin composition due to the excessive use of triacetin. Preferably, the resin composition may contain 1 part by weight or more, 3 parts by weight or more, 5 parts by weight or more, 7 parts by weight or more, or 10 parts by weight or more, and 23 parts by weight or less, 22 parts by weight or less, or 20 parts by weight or less of triacetin based on 100 parts by weight of the total resin composition. For example, with respect to the total 100 parts by weight of the resin composition, triacetin may be included in an amount of 1 to 20 parts by weight, or 5 to 20 parts by weight, or 10 to 20 parts by weight.

[0059]

[0060] Additionally, in the present invention, the polydispersity index (PDI) of the polybutylene adipate terephthalate may be 2.5 or less.

[0061] Additionally, the melt index (measured at 190° C. under a load of 2.16 kg according to ASTM D123) of the polybutylene adipate terephthalate may be 2.0 to 6.0 g / 10 min.

[0062] When the polydispersity index and / or melt index of polybutylene adipate terephthalate satisfies the above range, the miscibility with triacetin is improved, so that a homogeneous resin composition can be manufactured, and when manufacturing a molded article including the resin composition, surface defects can be reduced while processability and productivity can be improved. Specifically, the melt index (measured at 190°C under a load of 2.16 kg according to ASTM D123) of the polybutylene adipate terephthalate may be 2.0 g / 10 min or more, 2.3 g / 10 min or more, or 2.5 g / 10 min or more, and 5.7 g / 10 min or less, 5.5 g / 10 min or less, 5.3 g / 10 min or less, or 5.0 g / 10 min or less.

[0063]

[0064] Meanwhile, the resin composition according to the present invention may only include polybutylene adipate terephthalate and triacetin as resin components. That is, it may be preferable that the resin composition according to one example of the present invention not include any other resin or polymer components other than polybutylene adipate terephthalate. For example, the resin composition according to the present invention may include 1 to 25 parts by weight of triacetin and the remainder of polybutylene adipate terephthalate based on 100 parts by weight of the total resin composition, but the present invention is not limited thereto.

[0065]

[0066] Meanwhile, the resin composition of the present invention may further include other additives, if necessary. These additives can be any additive commonly used in the molding of resin compositions within the technical field to which the present invention pertains, i.e., the thermoplastic polymer field, without particular limitation. These additives may include heat stabilizers, UV stabilizers, and the like.

[0067]

[0068] In addition, according to another aspect of the present invention, a biodegradable resin molded article comprising the above-described resin composition is provided. The biodegradable resin molded article may be a biodegradable film.

[0069]

[0070] According to one example of the invention, the biodegradable resin molded product may have a modulus value of 30 to 100 MPa as measured according to ASTM D882. If the modulus value is less than 30 MPa, it may be inconvenient to use as a packaging material wrap, and if it exceeds 100 MPa, the easy-cut characteristic may be reduced. Preferably, the modulus value may be 30 MPa or more, 31 MPa or more, 32 MPa or more, or 33 MPa or more, and 95 MPa or less, 90 MPa or less, or 85 MPa or less.

[0071]

[0072] According to one example of the invention, the biodegradable resin molded article may have an adhesive value of 5 to 20 N as measured according to ASTM D882 standards. When the adhesive value of the biodegradable resin molded article satisfies the above range, it is suitable for use as a food packaging material. Preferably, the adhesive value may be 5 N or more, and 19 N or less, 18 N or less, 17 N or less, or 16 N or less.

[0073]

[0074] According to one example of the invention, the oxygen permeability of the biodegradable resin molded product is 100 to 400 cc / m based on a sheet thickness of 500 to 600 ㎛. 2 ·day·atm. Preferably, the oxygen permeability is 150 cc / m 2 ·day·atm, 200 cc / m 2 ·day·atm, or 230 cc / m 2 ·day·atm or more, 370 cc / m 2 ·day·atm or less, 350 cc / m2 ·day·atm or less, 330 cc / m 2 ·day·atm or less, 300 cc / m 2 ·day·atm or less, or 270 cc / m 2 ·day·atm or less. The above oxygen permeability is measured at 23°C, RH 0%, and the specific measurement method can be specified in the examples described below.

[0075]

[0076] According to one example of the invention, the moisture permeability of the biodegradable resin molded product is 50 to 95 g / m based on a sheet thickness of 500 to 600 ㎛. 2 ·day. Preferably, the moisture permeability is 55 g / m 2 ·day or more, 60 g / m 2 ·day or more, 65 g / m 2 ·day or more, 70 g / m 2 ·day or more, 75 g / m 2 ·day or more, 80 g / m 2 ·day or more, or 85 g / m 2 ·day or more, 90 g / m 2 ·It may be less than day. The above moisture permeability is measured at 38℃, RH 90%, and the specific measurement method can be specified in the examples described below.

[0077]

[0078] A biodegradable resin molded product according to an example of the present invention can be used for purposes such as food packaging materials based on its excellent adhesiveness, mechanical properties, and gas permeability.

[0079]

[0080] As described above, the resin composition of the present invention can realize adhesiveness, mechanical properties, and breathability suitable for use as a packaging material wrap while maintaining the biodegradability of polybutylene adipate terephthalate.

[0081]

[0082] Hereinafter, preferred embodiments are presented to aid understanding of the invention. However, the following examples are intended only to illustrate the invention and are not intended to limit the invention to these embodiments.

[0083]

[0084] <Example>

[0085] Preparation of resin composition 1

[0086] A resin composition was prepared according to the composition in Table 1 below. Specifically, polybutylene adipate terephthalate was dried at 80°C. After the internal mixer (Brbender) was heated to 190°C, 83.3 parts by weight of the dried polybutylene adipate terephthalate and 16.7 parts by weight of the additives described in Table 1 below were added to a total of 100 parts by weight of the resin composition, and blended at 190°C for 6 minutes, thereby preparing a resin composition.

[0087] The above polybutylene adipate terephthalate used had a weight average molecular weight of 130,000 g / mol and a polydispersity index (PDI) of 2.5 (MI = 5.0 g / 10 min @ 190 ℃, 2.16 kg).

[0088]

[0089] Physical property evaluation

[0090] The melting temperature (Tm), tensile strength, elongation, and migration of the above-mentioned manufactured resin composition were evaluated, and are shown in Table 1 below.

[0091]

[0092] 1) Melting temperature (Tm)

[0093] - Use of Differential Scanning Calorimetry (DSC, TA DSC250) device

[0094] - Thermal characteristics analysis using Trios S / W at a temperature range of -60 to 200 ℃ and a heating rate of 10 ℃ / min

[0095] - Prepare about 5 to 10 mg of resin composition, press it into a pan, load it, and then measure it.

[0096]

[0097] 2) Tensile strength and elongation

[0098] - Use of Wabash Hot Press machine

[0099] - 190℃, 3 min press, then 30℃, 2 min press to produce 500~600um sheet

[0100] - Using ASTM D882 measurement standard and specimen, measuring speed 500 mm / min

[0101]

[0102] 3) Migration Evaluation

[0103] The above-mentioned resin composition was cooled to room temperature, and after one day from the cooling point, it was evaluated using tissue paper to see if the additive came out.

[0104]

[0105] PBAT content (weight part) Additive DSC, Tm (℃) Tensile strength (MPa) Tensile elongation (%) Migration Comparative example 1-1100-110.921.31,331-Comparative example 1-283.3 LG chem, GL500 1) 117.922.01,438OComparative Example 1-383.3Diisononyl adipate 117.923.91,410OComparative Example 1-483.3Acetyl tributyl citrate 113.920.41,413OComparative Example 1-583.3Epoxidized soybean oil 2) 118.423.11,256O Example 1-183.3Triacetin120.225.11,238X

[0106] 1) LG CHEM GL500 (1,4-Benzenedicarboxylic acid, mixed Bu and 2-ethylhexyl diesters)2) Epoxidized soybean oil (Product name: 412333, Manufacturer: Sigma Aldrich)

[0107]

[0108] Preparation of resin composition 2

[0109] A resin composition was prepared according to the composition shown in Table 2 below. Specifically, polybutylene adipate terephthalate was dried at 80°C, and then polybutylene adipate terephthalate and triacetin were uniformly mixed with the composition shown in Table 2 below for a total of 100 parts by weight of the resin composition. Thereafter, the resin composition was prepared by extruding it into a twin-screw extruder (twin-screw extruder, Korea EM Co., Φ= 32 mm, L / D= 40-44) heated to 170°C, and extruding it under the extrusion conditions of an extrusion temperature of 170°C, an extrusion speed of 10 kg / hr, and a screw rotation speed of 200 rpm.

[0110]

[0111] PBAT content (parts by weight)PBAT weight average molecular weight (g / mol)PBAT PDItriacetin content (parts by weight)DSC, Tm (℃)Comparative Example 2-1100130,0002.5-121.3Comparative Example 2-28550,0002.515110.3Example 2-199130,0002.51121.0Example 2-295130,0002.55119.6Example 2-385130,0002.515110.7Example 2-475130,0002.525106.6Example 2-585160,0002.515112.1Example 2-685190,0002.515112.5

[0112] Physical property evaluation

[0113] The above-mentioned manufactured resin composition, or sheet or film containing the same, was evaluated for modulus, strength, elongation, migration and adhesion, and the results are shown in Table 3 below.

[0114]

[0115] 1) Press specimen modulus, strength and elongation

[0116] - Use of Wabash Hot Press machine

[0117] - 190 ℃, 3 min press, then 30 ℃, 2 min press to produce 500~600 um sheet

[0118] - Using ASTM D882 measurement standard and specimen, measuring speed 500 mm / min

[0119]

[0120] 2) Film specimen modulus, strength and elongation

[0121] - Eurexma uses cast film equipment

[0122] - Production of films with a thickness of less than 100 um at an extrusion temperature of 150 to 170°C and an extrusion speed of 60 to 90 rpm.

[0123] - Using ASTM D882 measurement standard and specimen, measuring speed 500 mm / min

[0124]

[0125] 3) Migration

[0126] The above-mentioned resin composition was cooled to room temperature, and after one day from the cooling point, it was evaluated using tissue paper to see if the additive came out.

[0127]

[0128] 4) Adhesiveness

[0129] - Eurexma uses cast film equipment

[0130] - Production of films with a thickness of less than 100 um at an extrusion temperature of 150 to 170°C and an extrusion speed of 60 to 90 rpm.

[0131] - Cut the film into 13mm wide and 150mm long pieces and prepare two pieces. Place each piece 50mm in the middle and press 1kg for 3 minutes.

[0132] - Use of ZwickRoell tensile testing machine

[0133] - ASTM D882 measurement standard, measuring maximum N (Newton) value at a measurement speed of 50 mm / min

[0134]

[0135] Press specimenFilm specimenMigrationAdhesion(N)Modulus(MPa)Strength(MPa)Elongation(%)Modulus(MPa)Strength(MPa)Elongation(%)Comparative Example 2-185.825.11,23886.476.4236-< 5.0Comparative Example 2-215.412.565817.327.3172X (Excellent)14.3Example 2-180.525.31,32579.878.5256X (Excellent)5.1Example 2-270.125.21,35268.879.2264X (Excellent)6.5Example 2-341.525.91,55740.981.9274X (Excellent) 15.2 Example 2-433.519.31, 40534.279.4329△ (Slightly slippery) 6.2 Example 2-543.325.41, 32241.179.9285X (Excellent) 15.0 Example 2-640.625.81, 31042.380.5294X (Excellent) 15.1

[0136] As can be seen in Table 3 above, the resin composition according to the embodiment of the present invention exhibited easy-cut characteristics, with a similar tensile strength as that of Comparative Example 2-1, which did not contain triacetin, while the modulus decreased and the elongation increased. On the other hand, Comparative Example 2-2, in which the PBAT molecular weight was lower than that of the PBAT included in the resin composition of the present invention, exhibited very low tensile properties compared to the existing PBAT, making it unsuitable for use as a wrap.

[0137]

[0138] Blocking performance evaluation

[0139] A resin composition was prepared using the manufacturing method of the resin composition preparation 1 according to the composition shown in Table 4 below, and after being prepared into a sheet, the oxygen permeability and moisture permeability were measured, and the results are shown in Table 4 below.

[0140]

[0141] 1) Sheet manufacturing

[0142] - Use of Wabash Hot Press machine

[0143] - 190 ℃, 3 min press, then 30 ℃, 2 min press to produce 500~600 um sheet

[0144]

[0145] 2) Oxygen permeability

[0146] - Using Systech Illinois 8001 oxygen permeability meter

[0147] - 5 cm 2 Use circular sheets of the same size

[0148] - Oxygen (>99.9%) supply pressure 1.5 bar, relative humidity 0%, measurement temperature 23℃, measurement at 15-minute intervals for 48 hours

[0149]

[0150] 3) Moisture permeability

[0151] - Using Systech Illinois AquaSense 7101 moisture permeability meter

[0152] - 5 cm 2 Use circular sheets of the same size

[0153] - Nitrogen (Carrier gas) supply pressure 2 bar, relative humidity 90%, measurement temperature 23℃, measurement at 10-minute intervals for 48 hours

[0154]

[0155] Resin type and content (parts by weight) Resin weight average molecular weight (g / mol) Resin PDI Triacetin content (parts by weight) Oxygen permeability (cc / m 2 ·day·atm)Moisture permeability (g / m) 2 ·day)Comparative Example 3-1PBAT (100)130,0002.5-6754Comparative Example 3-2PVC 1) (100)150,0002.5-50024Comparative Example 3-3PBAT (66.7)130,0002.533.3885100Example 3-1PBAT (83.3)130,0002.516.724287Example 3-2PBAT (83.3)160,0002.516.724989

[0156] 1) PVC (Manufacturer: Power Lab Co., Ltd., Product Name: Cling Wrap)

[0157] As can be confirmed in Table 4 above, the resin composition according to the embodiment of the present invention was confirmed to have both oxygen permeability and moisture permeability increased simultaneously compared to Comparative Example 3-1 that did not contain triacetin, and compared to Comparative Example 3-3 that contained a high content of existing wrap PVC and triacetin, the oxygen permeability was decreased while the moisture permeability was increased, confirming that it has high potential for use as a breathable film.

Claims

Contains polybutylene adipate terephthalate (PBAT) and triacetin, The weight average molecular weight of the above polybutylene adipate terephthalate is 100,000 to 200,000 g / mol, With respect to the total 100 parts by weight of the resin composition, triacetin is included in an amount of 1 to 25 parts by weight. Resin composition. In the first paragraph, The weight average molecular weight of the above polybutylene adipate terephthalate is 130,000 to 190,000 g / mol. Resin composition. In the first paragraph, The polydispersity index (PDI) of the above polybutylene adipate terephthalate is 2.5 or less, Resin composition. In the first paragraph, The melt index of the above polybutylene adipate terephthalate (measured at 190°C under a load of 2.16 kg according to ASTM D1238) is 2.0 to 6.0 g / 10 min. Resin composition. In the first paragraph, With respect to the total 100 parts by weight of the resin composition, triacetin is included in an amount of 1 to 20 parts by weight. Resin composition. Comprising a resin composition according to any one of claims 1 to 5, Biodegradable resin molded products. In paragraph 6, A modulus value of 30 to 100 MPa measured according to ASTM D882 standard, Biodegradable resin molded products. In paragraph 6, Having an adhesion value of 5 to 20 N as measured according to ASTM D882 standard, Biodegradable resin molded products. In paragraph 6, The oxygen permeability of the above biodegradable resin molded product is 100 to 400 cc / m based on a sheet thickness of 500 to 600 ㎛. 2 ·day·atm, Biodegradable resin molded products. In paragraph 6, The moisture permeability of the above biodegradable resin molded product is 50 to 95 g / m based on a sheet thickness of 500 to 600 ㎛. 2 ·dayin, Biodegradable resin molded products.

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