Thermoplastic elastomer material, process for its preparation and use

Abstract

This invention relates to a thermoplastic elastomer material, its preparation method, and its applications, belonging to the technical field of polymer compound compositions. The thermoplastic elastomer material of this invention, by weight, comprises the following components: 28-42 parts PBAT resin, 20-30 parts TPEE resin, 20-30 parts SEBS elastomer, 10-20 parts naphthenic oil, 10-20 parts biodegradable filler, 3-8 parts compatibilizer, and 1.8-5.2 parts degradation control agent; the biodegradable filler has a particle size D50 of 10 μm to 20 μm; the degradation control agent is a mixture of photosensitizer, chitin, and polycarbodiimide. This thermoplastic elastomer material possesses excellent mechanical properties, adhesive bonding properties, and biodegradability.

Description

Technical Field

[0001] This invention relates to the field of polymer compound composition technology, specifically to a thermoplastic elastomer material, its preparation method, and its application. Background Technology

[0002] PBAT (polybutylene adipate / terephthalate) is a biodegradable polyester that degrades rapidly in industrial composting environments and is widely used in packaging films, tableware, and other fields. However, PBAT products are typically hard and have a cold feel, requiring overlay with soft TPE materials to improve feel, slip resistance, and aesthetics. However, traditional TPE materials have poor compatibility with PBAT, easily leading to insufficient adhesive strength; moreover, conventional TPE materials are not biodegradable, preventing the overlaid PBAT products from degrading simultaneously after disposal, causing recycling difficulties. Therefore, there is an urgent need to develop a thermoplastic elastomer material that firmly bonds to PBAT products and can rapidly degrade simultaneously after disposal. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings of the prior art and provide a thermoplastic elastomer material, its preparation method, and its application.

[0004] To achieve the above objectives, the technical solution adopted by the present invention is as follows: In a first aspect, the present invention provides a thermoplastic elastomer material comprising, by weight, the following components: 28-42 parts of PBAT resin, 20-30 parts of TPEE resin, 20-30 parts of SEBS elastomer, 10-20 parts of naphthenic oil, 10-20 parts of biodegradable filler, 3-8 parts of compatibilizer, and 1.8-5.2 parts of degradation control agent; The particle size D50 of the biodegradable filler is 10 μm to 20 μm; The degradation control agent is a mixture of photosensitizer, chitin, and polycarbodiimide.

[0005] This invention uses a combination of PBAT resin and TPEE resin as the matrix resin. This not only enhances the resilience of the overcoating layer to improve the feel and anti-slip properties of the PBAT substrate surface, but also promotes interfacial diffusion and entanglement during the molten coating of the thermoplastic elastomer material onto the PBAT substrate, thereby improving the coating adhesion. The SEBS elastomer combined with naphthenic oil not only promotes the wetting and encapsulation of the molten thermoplastic elastomer material on the PBAT substrate surface, improving the adhesion during overcoating, but also forms a "hard-soft" composite system with TPEE and PBAT resins. This composite system, combined with biodegradable fillers that increase degradation sites, effectively improves stress transfer to maintain good mechanical properties. A degradation regulator composed of photosensitizers, chitin, and polycarbodiimide ensures the stable use of the thermoplastic elastomer material during its service life and accelerates its degradation synchronously with the PBAT substrate after disposal, thus improving the recycling of PBAT-coated products.

[0006] It should also be noted that PBAT resin and TPEE resin in the thermoplastic elastomer material are used together as matrix resins, and the mass percentage of the matrix resin in the thermoplastic elastomer material is ≥35%, preferably ≥45%.

[0007] In some embodiments, the weight parts of PBAT resin in the thermoplastic elastomer material may be, but are not limited to, any one or any two of the following values: 28 parts, 29 parts, 30 parts, 31 parts, 32 parts, 33 parts, 34 parts, 35 parts, 36 parts, 37 parts, 38 parts, 39 parts, 40 parts, 41 parts, and 42 parts.

[0008] In some embodiments, the weight parts of TPEE resin in the thermoplastic elastomer material may be, but are not limited to, any one or any two of the following values: 20 parts, 21 parts, 22 parts, 23 parts, 24 parts, 25 parts, 26 parts, 27 parts, 28 parts, 29 parts, and 30 parts.

[0009] In some embodiments, the weight percentage of SEBS elastomer in the thermoplastic elastomer material may be, but is not limited to, any one or both of the following ranges: 20 parts, 21 parts, 22 parts, 23 parts, 24 parts, 25 parts, 26 parts, 27 parts, 28 parts, 29 parts, and 30 parts.

[0010] In some embodiments, the weight parts of naphthenic oil in the thermoplastic elastomer material may be, but are not limited to, any one or both of the following ranges: 10 parts, 11 parts, 12 parts, 13 parts, 14 parts, 15 parts, 16 parts, 17 parts, 18 parts, 19 parts, and 20 parts.

[0011] In some embodiments, the weight percentage of biodegradable filler in the thermoplastic elastomer material may be, but is not limited to, any one or both of the following ranges: 10 parts, 11 parts, 12 parts, 13 parts, 14 parts, 15 parts, 16 parts, 17 parts, 18 parts, 19 parts, and 20 parts.

[0012] In some embodiments, the weight parts of the compatibilizer in the thermoplastic elastomer material may be, but are not limited to, any one or any two of the following values: 3 parts, 3.2 parts, 3.4 parts, 3.6 parts, 3.8 parts, 4 parts, 4.2 parts, 4.4 parts, 4.6 parts, 4.8 parts, 5 parts, 5.2 parts, 5.4 parts, 5.6 parts, 5.8 parts, 6 parts, 6.2 parts, 6.4 parts, 6.6 parts, 6.8 parts, 7 parts, 7.2 parts, 7.4 parts, 7.6 parts, 7.8 parts, and 8 parts.

[0013] In some embodiments, the weight parts of the degradation control agent in the thermoplastic elastomer material may be, but are not limited to, any one or any two of the following: 1.8 parts, 2 parts, 2.2 parts, 2.4 parts, 2.6 parts, 2.8 parts, 3 parts, 3.2 parts, 3.4 parts, 3.6 parts, 3.8 parts, 4 parts, 4.2 parts, 4.4 parts, 4.6 parts, 4.8 parts, 5 parts, and 5.2 parts.

[0014] In some embodiments, the particle size D50 of the biodegradable filler may be, but is not limited to, a range of any or both of 10 μm, 11 μm, 12 μm, 13 μm, 14 μm, 15 μm, 16 μm, 17 μm, 18 μm, 19 μm, and 20 μm.

[0015] In a preferred embodiment of the thermoplastic elastomer material of the present invention, the mass ratio of the photosensitizer, chitin and polycarbodiimide is (0.5~1.5):(0.5~1.5):(0.5~1.5), preferably (0.8~1.2):(0.8~1.2):(0.8~1.2), and more preferably 1:1:1.

[0016] Polycarbodiimide can inhibit the hydrolysis of thermoplastic elastomers during use to ensure the stability of mechanical properties. In the post-disposal degradation process, photosensitizers can promote photo-oxidation to generate microcracks, exposing chitin to attract microbial attachment and degradation. When the mass ratio of the three is within the above range, it is more conducive to achieving controllable degradation of thermoplastic elastomers.

[0017] In some embodiments, the photosensitizer in the degradation control agent, by weight, may specifically be, but is not limited to, any one or any two of the following ranges: 0.5 parts, 0.6 parts, 0.7 parts, 0.8 parts, 0.9 parts, 1 part, 1.1 parts, 1.2 parts, 1.3 parts, 1.4 parts, and 1.5 parts.

[0018] In some embodiments, the chitin in the degradation control agent, by weight, may specifically be, but is not limited to, any one or both of the following ranges: 0.5 parts, 0.6 parts, 0.7 parts, 0.8 parts, 0.9 parts, 1 part, 1.1 parts, 1.2 parts, 1.3 parts, 1.4 parts, and 1.5 parts.

[0019] In some embodiments, the polycarbodiimide in the degradation control agent, by weight, may specifically be, but is not limited to, any one or both of the following ranges: 0.5 parts, 0.6 parts, 0.7 parts, 0.8 parts, 0.9 parts, 1 part, 1.1 parts, 1.2 parts, 1.3 parts, 1.4 parts, and 1.5 parts.

[0020] As a preferred embodiment of the thermoplastic elastomer material of the present invention, the PBAT resin has a melt mass flow rate of 2 g / 10 min to 10 g / 10 min at 190°C and 2.16 kg (standard ISO 1133-1-2011), for example, but not limited to any one or any two of the following values: 2 g / 10 min, 2.5 g / 10 min, 3 g / 10 min, 3.5 g / 10 min, 4 g / 10 min, 4.5 g / 10 min, 5 g / 10 min, 5.5 g / 10 min, 6 g / 10 min, 6.5 g / 10 min, 7 g / 10 min, 7.5 g / 10 min, 8 g / 10 min, 8.5 g / 10 min, 9 g / 10 min, 9.5 g / 10 min, and 10 g / 10 min.

[0021] When the melt flow rate of PBAT resin is within the above range, it can better balance the mechanical properties, overmolding adhesion properties and biodegradability of thermoplastic elastomer materials.

[0022] As a preferred embodiment of the thermoplastic elastomer material of the present invention, the TPEE resin has a melt mass flow rate of 10 g / 10 min to 40 g / 10 min under the conditions of 230°C and 2.16 kg (standard ISO 1133-1-2011), for example, but not limited to any one or any two of the following values: 10 g / 10 min, 12 g / 10 min, 14 g / 10 min, 16 g / 10 min, 18 g / 10 min, 20 g / 10 min, 22 g / 10 min, 24 g / 10 min, 26 g / 10 min, 28 g / 10 min, 30 g / 10 min, 32 g / 10 min, 34 g / 10 min, 36 g / 10 min, 38 g / 10 min, and 40 g / 10 min.

[0023] When the melt flow rate of TPEE resin is within the above-mentioned range, it is more conducive to the thermoplastic elastomer material covering the PBAT substrate surface better during overmolding to form a dense and uniform overmolding layer, and to better promote the diffusion of molecular chains at the interface between the thermoplastic elastomer material and the PBAT substrate to improve the interfacial bonding strength. On the other hand, it is also conducive to optimizing the morphology of the blended phase, forming a more uniform island or co-continuous structure in synergy with the compatibilizer in the PBA-TPEE-SEBS multiphase system, so as to promote the dispersion and transmission of stress and achieve better mechanical properties.

[0024] As a preferred embodiment of the thermoplastic elastomer material of the present invention, the Shore hardness of the TPEE resin is 20D to 40D, for example, but not limited to any one or any two of 20D, 21D, 22D, 23D, 24D, 25D, 26D, 27D, 28D, 29D, 30D, 31D, 32D, 33D, 34D, 35D, 36D, 37D, 38D, 39D, and 40D.

[0025] The Shore hardness of TPEE resin is within the above range, which can better promote the matching between thermoplastic elastomer materials and PBAT substrate, reduce stress concentration at the interface between the overlay layer and PBAT substrate, and improve the adhesion durability of the overlay layer, while also taking into account the surface feel of the overlay layer.

[0026] As a preferred embodiment of the thermoplastic elastomer material of the present invention, at least a portion of the surface of the biodegradable filler is coated with a surface modifier, the surface modifier including at least one of silane coupling agents and titanate coupling agents.

[0027] In some embodiments, the surface modifier has a mass fraction of 1% to 3% relative to the biodegradable filler, preferably 1.5% to 2.5%, and more preferably 2%.

[0028] As a preferred embodiment of the thermoplastic elastomer material of the present invention, the thermoplastic elastomer material further includes 1 to 3 parts by weight of processing aids, for example, but not limited to any one or any two of the following: 1 part, 1.2 parts, 1.4 parts, 1.6 parts, 1.8 parts, 2 parts, 2.2 parts, 2.4 parts, 2.6 parts, 2.8 parts, and 3 parts.

[0029] In some embodiments, the processing aid may include, but is not limited to, at least one of lubricants and release agents; exemplary, including but not limited to erucamide, oleamide, silicone, etc.

[0030] As a preferred embodiment of the thermoplastic elastomer material of the present invention, at least one of the following conditions is met: (1) The biodegradable filler is at least one of starch and wood flour; preferably, the starch may include, but is not limited to, at least one of corn starch, potato starch, rice starch and cassava starch; (2) The compatibilizer is at least one of maleic anhydride-grafted SEBS and maleic anhydride-grafted POE; (3) The photosensitizer includes at least one of benzophenone, copolymer of ketene, and transition metal compound.

[0031] Secondly, the present invention provides a method for preparing the above-mentioned thermoplastic elastomer material, comprising the following steps: mixing the components uniformly and melting and extruding to obtain the thermoplastic elastomer material.

[0032] Optionally, the above preparation method can be carried out by melt extrusion using a twin-screw extruder, with a melt extrusion temperature of 160°C to 200°C and a screw speed of 200 rpm to 400 rpm.

[0033] Thirdly, the present invention provides an application of the above-mentioned thermoplastic elastomer material in the preparation of overmolding materials.

[0034] Fourthly, the present invention provides an overmolding material or component comprising the aforementioned thermoplastic elastomer material.

[0035] In some embodiments, the aforementioned overmolded component includes a PBAT substrate and an overmolding layer located on the PBAT substrate, the overmolding layer comprising the aforementioned thermoplastic elastomer material or being made directly from the aforementioned thermoplastic elastomer material.

[0036] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention uses a combination of PBAT resin and TPEE resin as the matrix resin. This not only enhances the resilience of the overcoating layer to improve the feel and anti-slip properties of the PBAT substrate surface, but also promotes interfacial diffusion and entanglement during the molten coating of the thermoplastic elastomer material onto the PBAT substrate, thereby improving the coating adhesion. The SEBS elastomer combined with naphthenic oil not only promotes the wetting and encapsulation of the molten thermoplastic elastomer material on the PBAT substrate surface, improving the adhesion during overcoating, but also forms a "hard-soft" composite system with TPEE and PBAT resins. This composite system, combined with biodegradable fillers that increase degradation sites, effectively improves stress transfer to maintain good mechanical properties. A degradation regulator composed of photosensitizers, chitin, and polycarbodiimide ensures the stable use of the thermoplastic elastomer material during its service life and accelerates its degradation synchronously with the PBAT substrate after disposal, thus improving the recycling of PBAT-coated products. Detailed Implementation

[0037] To better illustrate the purpose, technical solution, and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments.

[0038] Unless otherwise specified, all other materials, reagents, etc. used in the examples and comparative examples are commercially available.

[0039] 1. Raw materials and reagents 1) PBAT resin PBAT-1, melt flow rate of 4 g / 10 min, grade TH801T, manufacturer: Xinjiang Lanshan Tunhe; PBAT-2, melt flow rate of 3g / 10min, grade KHB21, manufacturer Kanghui New Materials.

[0040] 2) TPEE resin TPEE-1, Shore hardness 28D, melt flow rate 35g / 10min, grade H28DFE, manufacturer Jiangyin Hechuang; TPEE-2, Shore hardness 40D, melt flow rate 13g / 10min, grade H40DMG, manufacturer Jiangyin Hechuang.

[0041] 3) SEBS elastomer SEBS-1, brand name GLOBALPRENE 7551, manufacturer: Li Changrong; SEBS-2, grade GLOBALPRENE 7554, manufacturer: Li Changrong.

[0042] 4) Naphthenic oils and paraffin oils Naphthenic oil 1, grade KN4010, manufacturer: Karamay, Xinjiang; Naphthenic oil 2, grade KN4006, manufacturer: Karamay, Xinjiang; Paraffin oil, grade 500N, manufactured by CNOOC.

[0043] 5) Biodegradable fillers Biodegradable filler 1 has a particle size D50 of 12 μm; Biodegradable filler 2 has a particle size D50 of 18 μm; Biodegradable filler 3 has a particle size D50 of 10 μm; Biodegradable filler 4 has a particle size D50 of 12 μm; Biodegradable filler 5 has a particle size D50 of 25 μm; Biodegradable filler 6 has a particle size D50 of 5 μm; The above-mentioned biodegradable fillers 1, 2, 3, 5 and 6 are obtained by surface treatment of starch (corn starch, commercially available) with different particle sizes using silane coupling agent (KH-550, commercially available). Specifically, the following steps are included: diluting the silane coupling agent with ethanol at a mass ratio of 1:3 and then adding it to the starch and mixing evenly. The mass ratio of silane coupling agent to starch is 2:100.

[0044] The above-mentioned biodegradable filler 4 is obtained by surface treatment of wood flour (commercially available) with titanate coupling agent (TC201). Specifically, it includes the following steps: diluting titanate coupling agent and ethanol at a mass ratio of 1:3 and then adding them to the wood flour and mixing them evenly. The mass ratio of titanate coupling agent to wood flour is 2:100.

[0045] 6) Compatibilizer Compatibilizer 1 is SEBS-g-MAH, with a maleic anhydride grafting rate of 1.4% to 2.0%, brand name FG1901 GT, manufacturer: KETEN; Compatibilizer 2 is POE-g-MAH, with a maleic anhydride grafting rate of 0.8% to 1.2%, brand name PC-28, manufacturer: Nanhai Baichen.

[0046] 7) Degradation control agent Degradation control agent 1 is composed of photosensitizer 1, chitin and polycarbodiimide 1 in a mass ratio of 1:1:1; The degradation control agent 2 is composed of photosensitizer 1, chitin and polycarbodiimide 1 in a mass ratio of 0.5:0.5:1.5; The degradation control agent 3 is composed of photosensitizer 1, chitin and polycarbodiimide 1 in a mass ratio of 1.5:1.5:0.5; Degradation control agent 4 is composed of photosensitizer 2, chitin and polycarbodiimide 2 in a mass ratio of 1:1:1; Degradation control agent 5 is composed of photosensitizer 1 and polycarbodiimide 1 in a mass ratio of 1:1; Degradation control agent 6 is composed of chitin and polycarbodiimide in a mass ratio of 1:1. Degradation control agent 7 is composed of photosensitizer 1 and chitin in a mass ratio of 1:1; Photosensitizer 1 is benzophenone, industrial grade, manufactured by Hubei Weishi Chemical. Photosensitizer 2 is ferric acetylacetonate, industrial grade, manufactured by Yuanfeng Chemical. Chitosan, industrial grade, manufactured by Yanhao Biotechnology; Polycarbodiimide 1, brand name HyMax 213, manufacturer: Langyi Technology; Polycarbodiimide 2, brand name Hydrostab 3, manufactured by Schäfer Additive Systems GmbH, Germany.

[0047] 8) The processing aid is silicone, brand name GW-6200P, manufactured by Zhejiang Jiahua.

[0048] 2. Preparation method of the thermoplastic elastomer material of the present invention According to the formula, the components are mixed and then added to a twin-screw extruder for melt extrusion to obtain a thermoplastic elastomer material. The temperature settings of the twin-screw extruder are: zone 1 185℃, zone 2 195℃, zone 3 200℃, zone 4 205℃, zone 5 205℃, zone 6 210℃, and die head 210℃, and the screw speed is 300 rpm.

[0049] 3. Performance Testing 1) Tensile strength: Tested according to ISO 37:2024 standard, the specimen type is Type 1 (dumbbell type), the tensile rate is 500mm / min; the tensile specimen is placed at room temperature for 180 days and then the tensile strength is tested.

[0050] 2) Peel Strength: Peel tests were conducted according to VDI 2019 standards. The specific process was as follows: First, a 150mm × 40mm rectangular plate was cut from a metal sheet. Then, the rectangular plate was placed in a coating mold, and thermoplastic elastomer material was bonded to the surface of the metal sheet using an injection molding process at a temperature of 210℃. A multi-testing machine was used to peel the thermoplastic elastomer material from the coating test plate (90° peel). The force during the peeling process was measured and recorded. The higher the value, the greater the peel strength, indicating better coating adhesion.

[0051] 3) Degradation performance: Industrial composting tests were conducted according to EN13432:2000 standard. The biodegradation rate was tested for 180 days in a composting environment with a temperature of 60℃ and a humidity of 70%.

[0052] Table 1 shows the weight percentages and properties of each component in the thermoplastic elastomer materials of Examples 1 to 6. Table 2 shows the weight percentages and properties of each component in the thermoplastic elastomer materials of Examples 7 to 11. Table 3 shows the weight percentages and properties of each component in the thermoplastic elastomer materials of Examples 12 to 14. Table 4 shows the weight percentages and properties of each component in the thermoplastic elastomer materials of Comparative Examples 1 to 6. In Tables 1, 2, 3, and 4, " / " indicates that there are no relevant parameters.

[0053] According to the data in Tables 1 to 4, the tensile strength of the thermoplastic elastomer materials in Examples 1 to 14 is ≥7.0 MPa, the peel strength of the overmolding is ≥6.5 N / mm, and the biodegradability is ≥90%, indicating that the thermoplastic elastomer materials of the present invention have good mechanical properties, overmolding adhesion properties, and biodegradability. According to Example 1 and Comparative Example 1, replacing naphthenic oil with paraffin oil not only reduces the mechanical properties and overmolding adhesion properties of the thermoplastic elastomer materials but also deteriorates their biodegradability. According to Comparative Examples 2 and 3, it can be found that both excessively large and excessively small particle sizes of the biodegradable filler are detrimental to improving the mechanical properties and overmolding adhesion properties of the thermoplastic elastomer materials. According to Comparative Examples 4, 5, and 6, it can also be found that only by combining photosensitizer, chitin, and polycarbodiimide as degradation control agents can the mechanical properties, overmolding adhesion properties, and biodegradability properties of the thermoplastic elastomer materials be effectively improved.

[0054] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A thermoplastic elastomer material, characterized in that, By weight, it includes the following components: 28-42 parts PBAT resin, 20-30 parts TPEE resin, 20-30 parts SEBS elastomer, 10-20 parts naphthenic oil, 10-20 parts biodegradable filler, 3-8 parts compatibilizer, and 1.8-5.2 parts degradation control agent; The particle size D50 of the biodegradable filler is 10 μm to 20 μm; The degradation control agent is a mixture of photosensitizer, chitin, and polycarbodiimide.

2. The thermoplastic elastomer material as described in claim 1, characterized in that, The mass ratio of the photosensitizer, chitin, and polycarbodiimide is (0.5~1.5):(0.5~1.5):(0.5~1.5).

3. The thermoplastic elastomer material as described in claim 1, characterized in that, The PBAT resin has a melt flow rate of 2 g / 10 min to 10 g / 10 min at 190 °C and 2.16 kg.

4. The thermoplastic elastomer material as described in claim 1, characterized in that, The melt flow rate of the TPEE resin at 230°C and 2.16 kg is 10 g / 10 min to 40 g / 10 min.

5. The thermoplastic elastomer material as described in claim 4, characterized in that, The Shore hardness of the TPEE resin is 20D to 40D.

6. The thermoplastic elastomer material as described in claim 1, characterized in that, The thermoplastic elastomer material also includes 1 to 3 parts by weight of processing aids.

7. The thermoplastic elastomer material according to any one of claims 1 to 6, characterized in that, At least one of the following conditions must be met: (1) The biodegradable filler is at least one of starch and wood flour; (2) The compatibilizer is at least one of maleic anhydride-grafted SEBS and maleic anhydride-grafted POE; (3) The photosensitizer includes at least one of benzophenone, copolymer of ketene, and transition metal compound.

8. A method for preparing the thermoplastic elastomer material according to any one of claims 1 to 7, characterized in that, Includes the following steps: The components are mixed evenly, melted, and extruded to obtain a thermoplastic elastomer material.

9. The use of the thermoplastic elastomer material according to any one of claims 1 to 7 in the preparation of overmolding materials.

10. A coating material or component, characterized in that, Includes the thermoplastic elastomer material as described in any one of claims 1 to 7.

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