TPEE composition for coating film containing recycled TPEE

Abstract

The technical gist of the present invention is that a TPEE composition for a coating film containing recycled TPEE comprises 40 to 60 parts by weight of TPEE (thermoplastic polyester elastomer); 40 parts by weight of recycled TPEE; and 10 to 20 parts by weight of a compatibilizer. By preparing a TPEE composition containing recycled TPEE, it is possible to prevent environmental pollution and reduce manufacturing costs, and by appropriately selecting a compatibilizer, a TPEE composition for a coating film containing recycled TPEE with excellent mechanical properties can be obtained.

Description

Technology Field

[0001] The present invention relates to a TPEE composition for a coating film containing recycled TPEE, and more specifically, to a TPEE composition for a coating film containing recycled TPEE that can prevent environmental pollution and reduce manufacturing costs by manufacturing a TPEE composition containing recycled TPEE, and can have excellent mechanical properties by appropriately selecting a compatibilizer. Background Technology

[0002] Thermoplastic elastomers (TPEs) are high-performance materials that combine the elasticity of rubber with the moldability of plastic. Particularly due to their light specific gravity, they are being utilized in a wide range of fields—including automobiles, home appliances, construction materials, and clothing—to replace culcanized rubber and polyvinyl chloride (PVC), making them one of the materials expected to see a further increase in demand. Furthermore, TPEs possess excellent recyclability, making them a suitable material for addressing carbon neutrality, a key issue recently in Europe and Korea. As such, they can be utilized in a broad range of sectors, including automobiles and everyday materials, by replacing culcanized rubber and PVC.

[0003] With global interest in the severity of environmental pollution and the development of eco-friendly industries, the necessity of a circular economy is being highlighted, along with the ease of recycling and eco-friendliness of non-crosslinked thermoplastic elastomers. Here, the circular economy refers to an economic system where materials introduced into the economy are not discarded but are repeatedly used as useful resources within the economy, rather than a linear flow of materials from 'consumption to disposal'. Therefore, among thermoplastic elastomers, thermoplastic polyester elastomers (TPEE) are attracting attention as materials applicable to this circular economy.

[0004] TPEE has the advantage of being recyclable both mechanically and chemically. In particular, its excellent processability makes simple mechanical recycling easy, which serves as a driving force for cost competitiveness in the process. Therefore, there is a need to develop high-performance TPEE materials containing a high content of recycled TPE to meet the environmental and human-friendly consumption trends. The problem to be solved

[0005] The present invention was devised to solve the above-mentioned problems, and aims to provide a TPEE composition for a coating film containing recycled TPEE that can prevent environmental pollution and reduce manufacturing costs by manufacturing a TPEE composition containing recycled TPEE, and can have excellent mechanical properties by appropriately selecting a compatibilizer. means of solving the problem

[0006] The above objective is achieved by a TPEE composition for a coating film containing recycled TPEE, characterized by comprising 40 to 60 parts by weight of TPEE (thermoplastic polyester elastomer); 40 parts by weight of recycled TPEE; and 10 to 20 parts by weight of a compatibilizer.

[0007] Here, the compatibilizer is preferably selected from the group consisting of anhydride modified ethylene copolymer, ethylene-methyl acrylate-glycidyl methacrylate copolymer, ethylene-butyl acrylate copolymer, 2,3-epoxypropyl methacrylate, ethylene-methyl acrylate-glycidyl methacrylate terpolymer, and mixtures thereof.

[0008] In addition, the above-mentioned compatibilizer is 0.95 g / cm³ 3 It is desirable to have a density of 130 to 133°C, a melting point of 130 to 133°C, and a melt flow rate (MRF) of 4.0 to 25.0 g / 10 min. Effects of the invention

[0009] As described above, according to the present invention, by manufacturing a TPEE composition containing recycled TPEE, it is possible to prevent environmental pollution and reduce manufacturing costs, and by appropriately selecting a compatibilizer, it is possible to obtain a TPEE composition for a coating film containing recycled TPEE that can have excellent mechanical properties. Brief explanation of the drawing

[0010] FIG. 1 is the FT-IR of TPEE and recycled TPEE according to an embodiment of the present invention, and Figure 2 is a graph of the tensile strength of TPEE and recycled TPEE, and Figure 3 is a graph of the melt index of TPEE and recycled TPEE, and Figure 4 is a photograph of the blending of a TPEE composition using a uniaxial compressor, and FIG. 5 is a photograph of a TPEE composition prepared according to an embodiment of the present invention, and Figure 6 is a hardness graph of a TPEE composition, and Figure 7 is a graph of the tensile strength of the TPEE composition, and FIG. 8 is a graph of the tensile strength and elongation of a TPEE composition, and Figure 9 is an XRD analysis graph of a TPEE composition, and Figure 10 is a TGA graph of a TPEE composition, and FIG. 11 is a DSC graph of a TPEE composition, and Figure 12 is a graph of the thermal decomposition temperature of a TPEE composition, and FIG. 13 is a graph of the weight loss rate of a TPEE composition, and FIG. 14 is a graph of the glass transition temperature of a TPEE composition, and Figure 15 is a graph of the degree of crystallization of the TPEE composition. Specific details for implementing the invention

[0011] Hereinafter, the technical concept of the present invention will be explained in more detail using the attached drawings. The attached drawings are merely examples illustrated to explain the technical concept of the present invention in more detail, and therefore the technical concept of the present invention is not limited to the form of the attached drawings.

[0013] Generally, thermoplastic polyester elastomer (TPEE) materials use polybutylene terephthalate (PBT), a high-melting-point and highly crystalline aromatic polyester, as the hard segment and polytetramethylene glycol (PTMG), a linear polymer with a low glass transition temperature, as the soft segment. Due to this structure, TPEE is an elastomer with excellent mechanical properties and heat resistance.

[0014] Separately, polymer recycling faces many practical challenges. Even within the same type of polymer, compatibility is low due to differences in molecular weight and structure. Furthermore, it is recognized as a problem that must be addressed not only regarding the characteristics of the polymers themselves but also the degradation of physical properties that may occur during polymer processing steps such as melt extrusion and spinning.

[0015] Accordingly, when recycled TPEE is mixed with conventional TPEE, interfacial separation may occur due to insufficient mutual bonding force, and as a result of this, the mechanical properties and characteristics of the TPEE composition containing recycled TPEE may be weaker compared to conventional TPEE. To improve this problem, the present invention applies a compatibilizer to obtain a TPEE composition in order to lower the interfacial barrier and improve the reaction and miscibility between the two different polymers.

[0017] A TPEE composition for a coating film containing recycled TPEE according to an embodiment of the present invention comprises TPEE, recycled TPEE, and a compatibilizer.

[0018] TPEE (thermoplastic polyester elastomer) is a polymer generally used when manufacturing coating films, and refers to TPEE polymer that has never undergone coating film processing and is not recycled. It is preferable to add 40 to 60 parts by weight of such TPEE; if less than 40 parts by weight of TPEE is added, the durability of the coating film finally manufactured through the TPEE composition may be reduced, and if more than 60 parts by weight of TPEE is added, it becomes difficult to reduce the manufacturing costs of the TPEE composition and the coating film.

[0019] Recycled TPEE refers to a polymer obtained by feeding waste TPEE into an extruder and extruding it at a temperature of 200°C or higher. Waste TPEE (thermoplastic polyester elastomer waste) discarded after use in various industries is collected and fed into an extruder at a temperature of 200°C or higher to undergo a recycling process and transform it into recycled TPEE that can be compressed into a film. If the temperature of the extruder is below 200°C, the waste TPEE may not melt completely, and proper extrusion may not occur.

[0020] It is preferable to add 40 parts by weight of such recycled TPEE. If less than 40 parts by weight of recycled TPEE is added, it is difficult to reduce the manufacturing cost of the coating film and also difficult to achieve the objective of environmental protection. If more than 40 parts by weight of recycled TPEE is added, there is a disadvantage that the durability of the coating film is reduced.

[0021] A compatibilizer is an additive that provides compatibility between different raw materials, and in the present invention, it is added to provide compatibility between TPEE and recycled TPEE. Unlike conventional additives, such a compatibilizer reduces interfacial tension and increases interfacial adhesion, and contributes to stabilizing the morphology and dispersibility of TPEE and recycled TPEE when mixed.

[0022] Generally, the compatibilizers mainly used in TPEE are reactive compatibilizers and non-reactive compatibilizers. Reactive compatibilizers promote a chemical reaction between two polymer components during the manufacturing process to directly bond them, while non-reactive compatibilizers improve mixing properties at the physical interface without a chemical reaction.

[0023] Reactive compatibilizers are compatibilizers having maleic anhydride or an epoxy group that react with polar polymers to form covalent bonds. Alternatively, compatibilizers that form direct bonds through radical reactions using peroxides also belong to the category of reactive compatibilizers. In contrast, non-reactive compatibilizers include block copolymers that have affinity for both polymers, or surfactant series that interact through non-covalent bonds such as hydrogen bonds or van der Waals bonds. Therefore, in the present invention, since there is no significant difference in polarity between recycled TPEE and TPEE, a reactive compatibilizer was applied to ensure interfacial miscibility.

[0024] The compatibilizer of the present invention is preferably selected from the group consisting of anhydride modified ethylene copolymer, ethylene-methyl acrylate-glycidyl methacrylate copolymer, ethylene-butyl acrylate copolymer, 2,3-epoxypropyl methacrylate, ethylene-methyl acrylate-glycidyl methacrylate terpolymer, and mixtures thereof.

[0025] In detail, it is preferable to use the commercialization agent shown in Table 1.

[0027] chemical name structure characteristic BASFJoncryl ADR 4468 2,3-epoxypropyl methacrylate - Composed of copolymers with epoxy functional groups - Improved compatibility with polyester - Excellent thermal stability and chemical resistance SK Chemicals LotaderAX 8900 ethylene-methyl acrylate-glycidyl methacrylate terpolymer - Ethylene-glycidyl methacrylate copolymer DupontFusabondN525 anhydride modified ethylene copolymer - Excellent compatibility in maleic anhydride-modified polyolefin compatibilizer-TPEE blends - Improved mechanical properties and processability TWO H ChemHFS2100P maleic anhydride grafted high density polyethylene - - Maleic anhydride-modified polyolefin compatibilizer TWO H ChemHFS0100 maleic anhydride grafted high density polyethylene - - Maleic anhydride-modified polyolefin compatibilizer TWO H ChemHFS2100 maleic anhydride grafted high density polyethylene - - Maleic anhydride-modified polyolefin compatibilizer

[0029] At this time, the compatibilizer is 0.95 g / cm² 3It is preferable to use one having a density of 130 to 133°C, a melting point of 4.0 to 25.0 g / 10 min, and a melt flow rate (MRF), but is not limited thereto.

[0030] In addition, it is preferable to add 10 to 20 parts by weight of a compatibilizer. If the amount of compatibilizer is less than 10 parts by weight, proper compatibilization between TPEE and recycled TPEE may not occur, and consequently, crosslinking performance may decrease. If the amount of compatibilizer exceeds 20 parts by weight, the crosslinking time becomes longer, and as the amount of compatibilizer increases, the ratio of TPEE to recycled TPEE decreases, which may lower the durability of the recycled film.

[0031] Embodiments of the present invention will be described in more detail below.

[0033] <Example>

[0034] To confirm the differences in chemical structure among TPEE raw materials, analysis was performed using FT-IR (JASCO, FT / IR-6200, Japan), and the analysis conditions were ATR method at 4000 to 400 cm⁻¹. -1 64 scans were performed within the range. As shown in Figure 1, the FT-IR analysis results for each TPEE raw material exhibited asymmetric and symmetric stretching peaks of the allylpatic CH2 group (2950–2850 cm⁻¹) generated by the aromatic structure of PBT. -1 ) appeared, and C=O stretching of the PTMG ester bond (1720 cm -1 ) and CO streching (1240~1270 cm -1 It can be confirmed that it is a polymer resin with a TPEE structure through the appearance of a peak, and it was found that there is no significant difference in structure between raw materials.

[0036] To verify the physical properties of each TPEE raw material, samples were prepared and their properties were compared. After drying TPEE pellets in a hot air dryer at 90°C for 24 hours, the extrusion temperature was set to 230°C, and tensile specimens of different ratios were prepared using a press extruder (Length / diameter: 40) to compare their physical properties. Tensile tests on the injection-molded specimens were conducted according to ASTM standards. The specimens used for measurement were manufactured in the shape of a size 3 dumbbell, and the tensile test was performed using a UTM at room temperature at a speed of 200 mm / min.

[0038] classification Tensile strength (kgf / mm²) 2 ) Elongation rate (%) TPEE (Company A) 1.15 1770.27 TPEE (Company B) 2.43 671.61 Recycled TPEE (Company B) 2.93 1303.67

[0040] As shown in Figure 2 and Table 2, the tensile strength analysis results confirmed that Company A’s product exhibited a higher elongation than Company B’s product, which previously had a lower elongation, thus demonstrating that the product properties appeared as intended. When comparing the properties of the TPEE raw materials, Company A’s product showed a tensile strength of 1.15, which is less than 50% of Company B’s product's 2.93, while the elongation increased by approximately 400% to 1770%. This phenomenon is analyzed to have occurred because tensile strength and elongation generally have an inverse relationship.

[0042] To analyze the melt index of the TPEE raw materials, the amount of resin falling for 1 minute with a load of 2.16 kg at 230°C was measured, and as shown in Figure 3, the analysis results confirmed that all samples showed numerical values ​​exceeding the measurement limit of 50 g / 10 min.

[0043] Based on these results, the tensile strength is 1.15 kgf / mm 2 , TPEE with an elongation of 177.027%, and a tensile strength of 2.93 kgf / mm 2 The test was conducted using recycled TPEE with an elongation of 1303.67%.

[0045] A(HFS2100P) B(HFS0100) C(HFS2100) Density (g / cm³) 3 ) 0.95 0.95 0.95 Melting point (°C) 130 133 130 Melt Index (MFR) (g / 10min) 25.0 4.0 20.0 MFR testing conditions 190℃ / 2.16kg 190℃ / 2.16kg 190℃ / 2.16kg

[0047] TPEE (parts by weight) Recycled TPEE (parts by weight) Commercialization agent A (weight part) Commercial Agent B (parts by weight) Commercialization agent C (weight part) Example 1 60 40 - - - Example 2 50 40 10 - - Example 3 40 40 20 - - Example 4 50 40 - 10 - Example 5 40 40 - 20 - Example 6 50 40 - - 10 Example 7 40 40 - - 20

[0049] Polymer blending was performed using the raw materials shown in Tables 3 and 4 through the uniaxial compressor shown in Fig. 4. For polymer blending, TPEE, recycled TPEE, and a compatibilizer were fed into the uniaxial compressor, and the hopper, nozzle, and mold parts were set to 220°C, 230°C, and 240°C, respectively, with a rotation speed of 90 rpm.

[0050] As a result of verifying the TPEE composition obtained using a compressor, as shown in Fig. 5, no phase separation or phenomenon of raw material remaining unmelted was observed in any of the embodiments, and it can be confirmed that the TPEE composition was successfully obtained.

[0052] To analyze the melt index of the TPEE composition, the amount of TPEE composition dropped for 1 minute under a load of 2.16 kg at 230°C was measured, and the results are shown in Table 5. Since the melt index affects the workability of the TPEE composition, an appropriate melt index is required depending on the manufacturing process. The viscosity of the sample mixed only with TPEE and recycled TPEE was too low to measure, and it was confirmed that the viscosity of TPEE was lowered due to the compatibilizer used to prevent phase separation and reduce viscosity. Furthermore, among the samples using compatibilizers, it was confirmed that samples using products A and C exhibited melt indices suitable for the quantitative target.

[0054] Melt index (230℃, 2.16kg,g / min) Example 1 50 or more Example 2 43.6 Example 3 43.7 Example 4 39.4 Example 5 38.7 Example 6 40.7 Example 7 40.8

[0056] To verify the changes in physical properties according to the TPEE composition, hardness was measured as shown in Table 6 and Figure 6. Hardness was calculated by analyzing three samples using a Shore D-type hardness tester and presenting the average. As a result, it was found that in all examples, hardness increased as the proportion of the compatibilizer increased, and in particular, it was confirmed that the hardness of the sample using compatibilizer C met the quantitative target.

[0058] Hardness (Shore D) Example 1 30 Example 2 31 Example 3 41 Example 4 36 Example 5 39 Example 6 52 Example 7 54

[0060] Pellet prepared using the TPEE composition was dried in a 90°C hot air dryer for 24 hours before use. Then, the TPEE pellets were extruded at an extrusion temperature of 230°C using a press extruder (Length / diameter: 40) to produce tensile specimens of different ratios, and their physical properties were compared. Tensile tests on the injection-molded specimens were conducted according to ASTM standards. The specimens used for measurement were manufactured in the shape of dumbbell size 3, and the tensile test was performed using a UTM at room temperature at a speed of 200 mm / min.

[0062] Tensile strength (kgf / mm²) 2 ) Elongation rate (%) Example 1 1.160 513.8 Example 2 1.194 416.1 Example 3 2.068 550.0 Example 4 1.259 226.3 Example 5 2.617 645.8 Example 6 2.610 622.3 Example 7 2.399 546.2

[0064] As shown in Table 7, Figure 7, and Figure 8, the tensile strength of the TPEE composition was measured three times for each sample, and the average of the tensile strength and elongation was presented. A total of seven samples were analyzed according to the type and ratio of the compatibilizer. Generally, tensile strength and elongation increased as the ratio of the compatibilizer increased. In particular, in the case of Example 6, although a small amount of compatibilizer C (10 parts by weight) was included, compared to Example 1 which did not contain a compatibilizer, the tensile strength increased by more than twofold and the elongation by 110%, confirming that the physical properties were significantly improved. These results suggest that the chemical bonding between TPEE and recycled TPEE caused by the reactive compatibilizer resulted in higher physical properties than before, while the phase separation between the release resins in Example 1 also had an effect that lowered the physical properties.

[0066] X-ray diffraction analysis was performed as shown in Fig. 9 to confirm structural changes in the semicrystalline or liquid crystal blocks of the TPEE composition. X-ray diffraction analysis was conducted using WAXD analysis (λ = 0.154 nm) at a rate of 5° / min within the range of 5 to 50°. The TPEE composition was found to exhibit a very weak diffraction peak at approximately 2θ = 15.9 in all examples. Additionally, diffraction peaks were observed at 2θ = 16.4°, 17.9°, 21.3°, and 22.5°, which correspond to the diffraction peaks of the PBT segment responsible for crystallinity within the TPEE composition. In particular, the diffraction peaks appeared clearly, indicating a high content of crystalline PBT; furthermore, it was confirmed that there was no significant difference in peak shift or intensity even when a compatibilizer was mixed. Accordingly, it was determined that the structure of the material itself does not change even when a compatibilizer is added.

[0068] To confirm the change in thermal properties of the TPEE composition according to the commercialization agent, TGA (Thermo Gravimetric Analysis) and DSC (Differential Scanning Calorimetry) analyses were performed. TGA (TA instruments Inc., Q-500, USA) and DSC (TA instruments Inc., Q-100, USA) were used for the analysis, and the analysis conditions were set at a rate of 10℃ / min in the range of 80 to 800℃ for TGA and 0 to 250℃ for DSC.

[0070] Pyrolysis temperature (°C) Mass loss (%) Glass transition temperature (°C) Example 1 420.8 7.09 - Example 2 419.8 15.03 127.1 Example 3 419.2 22.13 129.8 Example 4 416.7 16.99 125.8 Example 5 418.7 25.37 126.9 Example 6 417.3 14.83 126.9 Example 7 418.2 21.10 127.3

[0072] As shown in Figures 10 and 11, through TGA and DSC analysis, the pyrolysis temperature in Table 8 and Figure 12, the weight loss rate in Figure 13, the glass transition temperature in Figure 14, and the degree of crystallization in Figure 15 were confirmed, showing a trend of change depending on the content of the compatibilizer. The most significant change was that in Example 1, which did not contain a compatibilizer, no peaks due to crystallization were formed; however, as mentioned in Table 9, as the degree of crystallization increased due to the reaction of the compatibilizer, the degree of crystallization according to the ratio increased rapidly. In particular, it was confirmed that this effect was prominent in compatibilizer C, and the glass transition temperature (Tg) generally increased with increasing proportion of the compatibilizer, and the weight loss rate also increased.

[0074] Enthalpy of melting (J / g) Degree of crystallization (%) Example 1 - - Example 2 1.75 13 Example 3 2.35 17 Example 4 1.09 8 Example 5 2.07 15 Example 6 1.29 9 Example 7 2.51 18

[0076] Thermal decomposition temperature (°C) Mass loss (%) Tg(℃) Degree of crystallization (%) Tensile strength (kgf / mm²) 2 ) Elongation rate (%) hardness Example 1 420.8 7.09 - - 1.160 513.8 30 Example 2 419.8 15.03 127.1 13 1.194 416.1 31 Example 3 419.2 22.13 129.8 17 2.068 550.0 41 Example 4 416.7 16.99 125.8 8 1.259 226.3 36 Example 5 418.7 25.37 126.9 15 2.617 645.8 39 Example 6 417.3 14.83 126.9 9 2.61 622.3 52 Example 7 418.2 21.10 127.3 18 2.399 546.2 54

[0078] Table 10 summarizes the mechanical properties of the TPEE composition according to the embodiments of the present invention. To confirm the optimal mixing of the TPEE composition for coating films, Examples 1 to 7 were prepared such that the ratios of compatibilizers A, B, and C were 10 parts by weight and 20 parts by weight, and melt index, tensile strength, hardness, TGA, and DSC analysis were performed to confirm the properties of these samples. In the tensile strength analysis, it was confirmed that Example 6 showed a tensile strength more than twice and an elongation of 110% compared to Example 1.

[0079] Regarding hardness, it was confirmed that hardness tended to increase as the proportion of the compatibilizer increased, due to the property improvement effect resulting from the formation of interpolymer bonds by the reactive compatibilizer. In particular, compatibilizer C was found to exhibit the highest Shore D hardness value in the low 50s. Similarly, in the analysis of thermal properties, it was confirmed that the glass transition temperature, crystallinity, and thermal decomposition temperature increased due to interpolymer cross-linking; in particular, crystallinity was found to increase significantly as the proportion of the compatibilizer increased.

[0080] The present invention is not limited to the embodiments described above, and its scope of application is diverse. Furthermore, it is understood that various modifications are possible without departing from the essence of the invention as claimed in the claims.

Claims

Claim 1 A TPEE composition for a coating film containing recycled TPEE, characterized by comprising 40 to 60 parts by weight of TPEE (thermoplastic polyester elastomer); 40 parts by weight of recycled TPEE; and 10 to 20 parts by weight of a compatibilizer. Claim 2 A TPEE composition for a coating film containing recycled TPEE according to claim 1, wherein the compatibilizer is selected from the group consisting of anhydride modified ethylene copolymer, ethylene-methyl acrylate-glycidyl methacrylate copolymer, ethylene-butyl acrylate copolymer, 2,3-epoxypropyl methacrylate, ethylene-methyl acrylate-glycidyl methacrylate terpolymer, and mixtures thereof. Claim 3 In claim 1, the above compatibilizer is 0.95 g / cm² 3 A TPEE composition for a coating film containing recycled TPEE, characterized by having a density of 130 to 133°C, a melting point of 130 to 133°C, and a melt flow rate (MRF) of 4.0 to 25.0 g / 10 min.

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