A TPEE composite material, its preparation method and application

Abstract

This invention discloses a TPEE composite material, comprising the following components by weight: 73-92 parts TPEE resin; 8-27 parts PET resin; wherein the sum of the weight parts of TPEE and PET is 100 parts; the melting point range of PET is 100-180℃; TPEE is a terephthalic acid-1,4-butanediol-polytetrahydrofuran ether glycol copolymer, and by weight percentage of total TPEE, TPEE is derived from 42-60% polytetrahydrofuran ether glycol, 18-33% terephthalic acid, and 15-25% 1,4-butanediol. This invention mainly utilizes low-melting-point PET and a specific repeating unit ratio of TPEE to significantly improve the melt flow and molding performance of the material in thin-wall injection molding, meeting the filling requirements of complex molds; furthermore, the selection of a composite stabilizer can effectively inhibit the performance degradation and UV weather resistance of the material during high-temperature processing.

Description

Technical Field

[0001] This invention relates to the field of polymer materials technology, and in particular to a TPEE composite material, its preparation method, and its application. Background Technology

[0002] Thermoplastic polyester elastomers (TPEEs) combine the elasticity of rubber with the processability of thermoplastic materials, and are widely used in the automotive, electronics, and home appliance industries. As automotive manufacturing moves towards lightweighting and integration, higher demands are being placed on the injection molding of large-size, thin-walled structural parts. Materials need to have higher melt flowability and good weather resistance to withstand long-term outdoor use.

[0003] Existing technologies generally use TPEE as an auxiliary material, either in the form of filaments or films. For example, Chinese patent CN117924785A discloses a supercritical extrusion TPEE-modified PET foam and its preparation process, in which TPEE is an auxiliary material, mainly comprising 70-80 parts PET, 5-15 parts TPEE, 7-9 parts chain extender composite particles, 5-6 parts nucleating agent composite ions, and 1-2 parts antioxidant composite particles. Chinese patent CN119505489A discloses a TPEE film, mainly containing 100 parts TPEE resin masterbatch, 0.5-2.0 parts crosslinking agent, 1.5-2.5 parts antioxidant, 0.5-1.0 parts tackifier, and 15-18 parts diatomaceous earth-supported nano-titanium dioxide. Chinese patent CN119956524A discloses a synthetic brush bristle comprising 55-75 parts TPEE resin, 25-45 parts polyester resin (PET or PBT), 5-10 parts compatibilizer, 8-16 parts modified polysiloxane, 12-24 parts plasticizer, 1-3 parts lubricant, 0.3-1 part antioxidant, and 0.6-1.2 parts stabilizer (phosphate ester stabilizer).

[0004] Currently, TPEE is commonly used as an auxiliary material in injection molding, but due to limitations in melt flow rate, it presents problems such as difficulty in mold filling and obvious weld lines in the molding of thin-walled parts. Furthermore, for light-colored parts, decorative parts, and other exposed surface materials, its resistance to ultraviolet radiation and yellowing is poor, leading to increased color difference after long-term use and affecting the appearance quality. Therefore, using TPEE in extrusion injection molding products presents insurmountable technical difficulties. Summary of the Invention

[0005] The purpose of this invention is to overcome the above-mentioned technical defects and provide a TPEE composite material with good thin-wall performance, high weld line strength, and good UV resistance, as well as its preparation method and application.

[0006] This invention is achieved through the following technical solution: A TPEE composite material, by weight, comprises the following components: 73-92 parts of TPEE resin; 8-27 parts of PET resin; The total weight of TPEE and PET is 100 parts. The melting point range of PET is 100-180℃; TPEE is a copolymer of terephthalic acid-1,4-butanediol-polytetrahydrofuran ether diol. By weight percentage, TPEE is derived from 42-60% polytetrahydrofuran ether diol, 18-33% terephthalic acid, and 15-25% 1,4-butanediol.

[0007] In the TPEE composite material of the present invention, the content of TPEE resin can be 73 parts, 74 parts, 75 parts, 76 parts, 77 parts, 78 parts, 79 parts, 80 parts, 81 parts, 82 parts, 83 parts, 84 parts, 85 parts, 86 parts, 87 parts, 88 parts, 89 parts, 90 parts, 92 parts, etc., and the content of PET resin can be 8 parts, 9 parts, 10 parts, 11 parts, 12 parts, 13 parts, 14 parts, 15 parts, 16 parts, 17 parts, 18 parts, 19 parts, 20 parts, 21 parts, 22 parts, 23 parts, 24 parts, 25 parts, 26 parts, 27 parts, etc.

[0008] In TPEE, the weight percentage derived from polytetrahydrofuran ether diol can be 42%, 43%, 44%, 45%, 46%, 47%, 48%, 49%, 50%, 51%, 52%, 53%, 54%, 55%, 56%, 57%, 58%, 59%, 60%, etc.; the weight percentage derived from terephthalic acid can be 18%, 19%, 20%, 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 29%, 30%, 31%, 32%, 33%, etc.; and the weight percentage derived from 1,4-butanediol can be 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24%, 25%, etc.

[0009] Preferably, based on the total weight percentage of TPEE, TPEE is derived from 48-55% polytetrahydrofuran ether diol, 27-30% terephthalic acid, and 15-25% 1,4-butanediol. The weight percentage content of each monomer is determined by proton nuclear magnetic resonance spectroscopy.

[0010] This invention does not limit the source of TPEE; it can be a commercially available product or obtained by self-production. A self-production method can be as follows: Terephthalic acid, polytetrahydrofuran ether, 1,4-butanediol, and a catalyst (the amount of catalyst added is 300-600 ppm based on the total weight of the monomers, which can be a titanate catalyst such as tetrabutyl titanate or isopropyl titanate) are added to a reaction vessel according to the specified ratio. After reacting at 190-230℃ for 2-4 hours, the temperature is raised to 235-255℃, and the system pressure is reduced to below 100 Pa within 0.5-1 hour. The reaction continues for another 2-4 hours. Stirring is stopped, nitrogen gas is introduced into the system, and the material is extruded from the die. After water cooling and pelletizing, TPEE resin is obtained.

[0011] PET is an abbreviation for polyethylene terephthalate. Preferably, the melting point of PET is in the range of 100-135℃, and the melting point is determined according to ISO 11357-3:2018 standard, with a heating rate of 10℃ / 10min.

[0012] The TPEE has a melt flow index of 100-300 g / 10 min, and the test conditions are 230℃ / 2.16 kg. The melt flow index is tested according to ISO 1133-1:2022 standard. Preferably, it is 150-250 g / 10 min.

[0013] To further improve performance degradation and UV weather resistance during high-temperature processing, 0-1 parts by weight of a composite stabilizer can be added. The composite stabilizer is selected from a combination of hindered amine light stabilizers, triazine UV absorbers, and triazole UV absorbers, preferably in a weight ratio of 1:(0.5-1):(0.5-1). The content of the composite stabilizer can be 0 parts, 0.1 parts, 0.2 parts, 0.3 parts, 0.4 parts, 0.5 parts, 0.6 parts, 0.7 parts, 0.8 parts, 0.9 parts, 1.0 parts, etc.

[0014] The hindered amine light stabilizer may be one or more of the following: UV-622, UV-3529, UV-770, UV-944, 783, 791, 3853, and 292. The triazine ultraviolet light absorber stabilizer is one or more of UV-1600, UV-1164, UV-1577, or UV-2373; The triazole UV absorber stabilizer is one or more of UV-234, UV-236, UV-P, UV-928, UV-627, UV-571, UV-360, UV-329, and UV-328.

[0015] Those skilled in the art can choose whether to add 0-2 parts of an additive according to actual needs. The additive is selected from at least one of antioxidants and lubricants.

[0016] Antioxidants can be tris(2,4-di-tert-butylphenyl) phosphite; 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene; 2,5-di-tert-butyl-4-hydroxybenzyl dimethylamine; diethyl-3,5-di-tert-butyl-4-hydroxybenzyl phosphate; stearyl-3,5-di-tert-butyl-4-hydroxybenzyl phosphate; 3,5-di-tert-butyl-4-hydroxyphenyl-3,5-distearate-thiotriazolylamine; 2,6-di-tert-butyl-4-hydroxymethylphenol; 2,4-di-(n-octylthio)-6-(4-hydroxy-3,5-di-tert-butylglycerol allyl ether)-1,3,5-triazine; N,N'-Hexamethylene di(3,5-di-tert-butyl-4-hydroxy-hydrogenated cinnamamide); N,N'-bis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl)hexamethylenediamine; β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate n-octadecyl ester; triethylene glycol di[3-(3,5-dimethyl-4-hydroxyphenyl)propionate]; triethylene glycol di[β-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionate]; 2,2'-thiodiethyl-di[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate; tetra[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] pentaerythritol ester; etc.

[0017] The lubricant may be at least one of stearate lubricants, fatty acid lubricants, and stearate ester lubricants; the stearate lubricant is selected from at least one of calcium stearate, magnesium stearate, and zinc stearate; the fatty acid lubricant is selected from at least one of fatty acids, fatty acid derivatives, and fatty acid esters; and the stearate ester lubricant is selected from pentaerythritol stearate.

[0018] Those skilled in the art can also modify the TPEE composite material of the present invention, such as by reinforcement modification (adding reinforcing fillers) or impact modification (adding toughening agents) to form a TPEE composition comprising TPEE composite material, toughening agent and / or filler.

[0019] Reinforcing fillers can include: talc, kaolin, silica, etc.

[0020] Toughening agents can be: maleic anhydride grafted POE (POE-g-MAH), maleic anhydride grafted SEBS (SEBS-g-MAH), or maleic anhydride grafted EPDM (EPDM-g-MAH), etc.

[0021] The preparation method of the TPEE composite material of the present invention includes the following steps: mixing the components evenly according to the formula, and granulating by extrusion through a twin-screw extruder to obtain the TPEE composite material. The length-to-diameter ratio of the screw of the extruder is (44~52):1. The mixed material is extruded in the twin-screw extruder at a processing temperature of 170~210℃ and a screw speed of 250~350 r / min.

[0022] The application of the TPEE composite material of the present invention is for the preparation of automotive interior parts.

[0023] The present invention has the following beneficial effects: This invention primarily utilizes low-melting-point PET blended with a specific repeating unit ratio of TPEE to significantly improve the material's fluidity and low-temperature molding performance. This results in good melt flow during thin-wall injection molding and the ability to mold at lower temperatures, meeting the filling requirements of complex molds. Simultaneously, it also exhibits good high-temperature resistance and xenon lamp aging resistance.

[0024] Furthermore, the use of composite stabilizers can further inhibit the performance degradation and UV weather resistance of materials during high-temperature processing. Detailed Implementation

[0025] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention. These all fall within the scope of protection of the present invention.

[0026] The raw materials used in this invention are sourced from the following sources: TPEE Resin-1: Feed composition: 42wt% polytetrahydrofuran ether glycol, 33wt% terephthalic acid, 25wt% 1,4-butanediol; melt index: 230g / 10min; test conditions: 230℃ / 2.16kg; self-made. The self-made method is as follows: According to the formula, terephthalic acid, polytetrahydrofuran ether, 1,4-butanediol, and tetrabutyl titanate catalyst (catalyst addition amount: 400ppm based on total monomer weight) are added to a reactor. After reacting at 210℃ for 3 hours, the temperature is raised to 245℃, and the system pressure is reduced to below 100Pa within 0.5-1 hour. The reaction continues for 3 hours. Stirring is stopped, nitrogen gas is introduced into the system, and the material is extruded from the die. After water cooling and pelletizing, TPEE resin is obtained. TPEE Resin-2: Feeding amount: 55wt% polytetrahydrofuran ether diol, 30wt% terephthalic acid, 15wt% 1,4-butanediol, melt index of 210g / 10min, test conditions of 230℃ / 2.16kg, prepared according to the method of TPEE Resin-1; TPEE Resin-3: Feeding amount: polytetrahydrofuran ether diol content 48wt%, terephthalic acid 27wt%, 1,4-butanediol 25wt%, melt index 200g / 10min, test conditions 230℃ / 2.16kg, prepared according to the method of TPEE Resin-1; TPEE Resin-4: Feeding amount: 60wt% polytetrahydrofuran ether diol, 18wt% terephthalic acid, 22wt% 1,4-butanediol, melt index of 205g / 10min, test conditions of 230℃ / 2.16kg, prepared according to the method of TPEE Resin-1; TPEE Resin-5: Feeding amount: polytetrahydrofuran ether diol content 39wt%, terephthalic acid 35wt%, 1,4-butanediol 26wt%, melt index 185g / 10min, test conditions 230℃ / 2.16kg, prepared according to the method of TPEE Resin-1; TPEE Resin-6: Feeding amount: 63wt% polytetrahydrofuran ether diol, 15wt% terephthalic acid, 22wt% 1,4-butanediol, melt index of 160g / 10min, test conditions of 230℃ / 2.16kg, prepared according to the method of TPEE Resin-1; PET-1: Melting point 110℃, LM501, Yizheng Chemical Fiber Company; PET-2: Melting point 130℃, WK-LMPET-130, Wankai New Materials; PET-3: Melting point 165℃, LM502, Yizheng Chemical Fiber Company; PET-4: Melting point 229℃, LM503, Yizheng Chemical Fiber Company; PET-5: Melting point 245℃, LM530, Yizheng Chemical Fiber Company; PET-6: Melting point is 253℃, PET FG600, Yizheng Chemical Fiber Company; Hindered amine light stabilizers: UV-622, commercially available; Triazine UV absorbers: The light stabilizer is UV-1577, which is commercially available. Triazole UV absorbers: The light stabilizer is UV-234, which is commercially available. Preparation method of TPEE composite material in examples and comparative examples: The components were mixed uniformly according to the specified ratio, and then extruded and granulated using a twin-screw extruder to obtain the TPEE composite material. The screw length-to-diameter ratio of the extruder was 48:1. The mixed material was extruded in the twin-screw extruder, with processing temperatures in each zone of the barrel at 170℃ / 180℃ / 190℃ / 200℃ / 210℃, and a screw speed of 300 r / min.

[0027] Test methods: (1) Formability of thin-walled parts: Injection at 230℃, with a thickness of 0.8mm, a width of 100mm, and a length of 1000mm, using a thin-walled mold, with an injection pressure of 50% and an injection speed of 50%, test the degree of completion of the thin-walled mold. The longer the spiral length, the better.

[0028] (2) Spiral length: The length of the spiral is tested by injection molding at 230℃, using a spiral mold, with an injection pressure of 75% and an injection speed of 70%.

[0029] (3) High temperature resistance: TPEE composite material was injection molded into a textured plate (texture number BYDG-1024) at 200℃, and then dried at 120℃ for 48 hours. The change in gloss of the material before and after the test was recorded. The gloss test was conducted according to ISO 2813-1994, and the test angle was 60°.

[0030] (4) Xenon lamp aging test: TPEE composite material was injection molded into a textured plate (texture number BYDG-1024) at 200℃. Then, according to ISO4892-2-2013 standard, the test duration was 1250 hours, and the color difference △E was tested after the test.

[0031] Table 1: Weight parts and test results of each component of TPEE composite materials in Examples 1-7 TPEE resin grade -1 -1 -1 -2 -3 -4 -1 TPEE resin content 80 75 90 80 80 80 80 PET label -1 -1 -1 -1 -1 -1 -2 PET content 20 25 10 20 20 20 20 antioxidants 0.3 / 0.3 0.3 0.3 0.3 0.3 thin-walled part formability excellent excellent excellent excellent excellent excellent excellent Helix length (mm) 965 992 943 985 972 958 952 Surface gloss change value 0.4 0.3 0.2 0.3 0.3 0.5 0.5 △E 4.0 4.1 3.9 3.5 3.6 3.8 4.2 As can be seen from Examples 1 / 4 / 5 / 6, the preferred embodiment of the repeating unit TPEE has a longer spiral length, better high-temperature resistance, and better resistance to xenon lamp aging.

[0032] Table 2: Weight parts of each component and test results of TPEE composite materials in Examples 8-10 and Comparative Examples 1-2 TPEE resin grade -1 -1 -1 -5 -6 TPEE resin content 80 80 80 80 80 PET label -3 -1 -1 -1 -1 PET content 20 20 20 20 20 antioxidants 0.3 0.3 0.3 0.3 0.3 Hindered amine light stabilizers 0.3 0.2 Triazine UV absorbers 0.15 0.2 Triazole UV absorbers 0.15 0.2 thin-walled part formability excellent excellent excellent good Difference Helix length (mm) 941 968 973 671 619 Surface gloss change value 0.7 0.2 0.2 1.0 0.9 △E 4.5 1.5 1.5 5.8 5.1 As can be seen from Examples 1 / 7 / 8, the preferred examples of PET with a longer spiral length, better high-temperature resistance, and better resistance to xenon lamp aging are achieved.

[0033] As can be seen from Examples 1 / 9 / 10, adding the composite stabilizer of this application can not only further improve the xenon lamp aging resistance, but also increase the spiral length and significantly improve the heat aging resistance.

[0034] As can be seen from Comparative Example 1 / 2, when the repeating unit of TPEE is not within the scope of this invention, the thin-wall formability is insufficient, the high-temperature resistance is insufficient, and the resistance to xenon lamp aging decreases.

[0035] Table 3: Weight parts of each component and test results of TPEE composite materials in Comparative Examples 3-7 TPEE resin grade -1 -1 -1 -1 -1 TPEE resin content 80 80 80 70 95 PET label -4 -5 -6 -1 -1 PET content 20 20 20 30 5 antioxidants 0.3 0.3 0.3 0.3 0.3 thin-walled part formability Difference Difference Difference excellent good Helix length (mm) 585 582 574 1020 923 Surface gloss change value 0.8 0.9 1.2 1.0 1.3 △E 4.8 4.6 4.8 5.8 6.3 As can be seen from Comparative Examples 3-6, when the melting point of PET is too high, the thin-walled formability is poor and the high-temperature resistance is insufficient.

[0036] As shown in Comparative Example 7, when the PET content is too high, although the spiral length is longer, the high temperature resistance and xenon lamp aging resistance are significantly reduced.

[0037] As shown in Comparative Example 8, when the PET content is too low, the thin-walled formability decreases, and the high-temperature resistance and xenon lamp aging resistance are insufficient.

Claims

1. A TPEE composite material, characterized in that, By weight, it includes the following components: 73-92 parts of TPEE resin; 8-27 parts of PET resin; The total weight of TPEE and PET is 100 parts. The melting point range of PET is 100-180℃; TPEE is a copolymer of terephthalic acid-1,4-butanediol-polytetrahydrofuran ether diol. By weight percentage, TPEE is derived from 42-60% polytetrahydrofuran ether diol, 18-33% terephthalic acid, and 15-25% 1,4-butanediol.

2. The TPEE composite material according to claim 1, characterized in that, Based on the total weight percentage of TPEE, TPEE is derived from 48-55% polytetrahydrofuran ether diol, 27-30% terephthalic acid, and 15-25% 1,4-butanediol.

3. The TPEE composite material according to claim 1, characterized in that, The melting point range of PET is 100-135℃.

4. The TPEE composite material according to claim 1, characterized in that, The TPEE has a melt index of 100-300 g / 10 min and is tested at 230℃ / 2.16 kg.

5. The TPEE composite material according to claim 1, characterized in that, Based on parts by weight, it also includes 0-1 parts of a composite stabilizer, wherein the composite stabilizer is selected from a combination of hindered amine light stabilizers, triazine UV absorbers, and triazole UV absorbers.

6. The TPEE composite material according to claim 5, characterized in that, The weight ratio of hindered amine light stabilizer / triazine UV absorber / triazole UV absorber is 1:(0.5-1):(0.5-1).

7. The TPEE composite material according to claim 1, characterized in that, The product also includes 0-2 parts by weight of additives, wherein the additives are selected from at least one of antioxidants and lubricants.

8. A method for preparing the TPEE composite material according to any one of claims 1-7, characterized in that, The process includes the following steps: mixing the components evenly according to the formula, and extruding and granulating them through a twin-screw extruder to obtain TPEE composite material.

9. The application of the TPEE composite material according to any one of claims 1-7, characterized in that, Used to manufacture automotive interior parts.