A TPEE composite material, its preparation method and application

Abstract

The present application discloses a TPEE composite material, a preparation method thereof and an application thereof, belonging to the field of polymer materials. The TPEE composite material of the present application is prepared by adding a chain extender and a specific fluorine-containing prepolymer to the TPEE resin, so that the fluorine-containing prepolymer reacts with the TPEE resin under the action of the chain extender, introducing fluoride into the TPEE molecular chain, and enabling the fluoride to have good dispersibility in the TPEE resin, thereby making the obtained composite material have good appearance, better wear resistance and more excellent mechanical properties, such as high tensile strength, and is suitable as a material for sealing rings of kitchen utensils such as ovens and dishwashers.

Description

Technical Field

[0001] This application relates to the field of polymer materials, and particularly to a TPEE composite material, a preparation method thereof, and an application thereof. Background Art

[0002] Thermoplastic polyester elastomer (TPEE) is often used in high-temperature oil-containing environments due to its excellent elasticity, high-temperature resistance, and solvent resistance. The operating environments of sealing systems for kitchen utensils such as ovens and dishwashers are often accompanied by high temperature, high humidity, and oil, and the kitchen utensils need to be frequently opened and closed, so the requirement for the wear resistance of the material is relatively high. Conventional TPV sealing rings have poor wear resistance and oil resistance is not as good as that of TPEE, so they are not suitable for the above-mentioned kitchen utensil sealing systems. For conventional wear-resistant modified TPEE materials, due to the poor dispersion of fillers and wear-resistant improvers in extrusion-grade TPEE, serious pitting problems occur during extrusion.

[0003] Therefore, it is necessary to develop a wear-resistant TPEE material with good appearance. Summary of the Invention

[0004] Based on the defects existing in the prior art, the purpose of this application is to provide a TPEE composite material, a preparation method thereof, and an application thereof. The obtained TPEE composite material not only has good appearance, but also has good wear resistance and excellent mechanical properties, such as high tensile strength.

[0005] To achieve the above purpose, in the first aspect, this application provides a TPEE composite material, which comprises the following components in parts by weight:

[0006] TPEE resin 89 - 99 parts;

[0007] Chain extender 0.5 - 2 parts;

[0008] Fluorine-containing prepolymer 1 - 5 parts;

[0009] The fluorine-containing prepolymer comprises at least one of the compounds of formula I,

[0010]

[0011] wherein, a is an integer from 2 to 8, b is an integer from 3 to 5, c is an integer from 2 to 4, and n is an integer from 60 to 90.

[0012] a is an integer from 2 to 8, such as 2, 3, 4, 5, 6, 7 or 8.

[0013] b is an integer from 3 to 5, such as 3, 4 or 5.

[0014] c is an integer from 2 to 4, such as 2, 3 or 4.

[0015] n is an integer from 60 to 90, such as 60, 65, 70, 75, 80, 85 or 90.

[0016] In traditional methods, fluoride abrasion resistant agents such as fluorine-containing elastomers and polytetrafluoroethylene are added to TPEE resin to improve abrasion resistance. However, these abrasion resistant agents have poor dispersibility in TPEE resin and are prone to producing pitting. In this application, a chain extender and a specific fluorine-containing prepolymer are added to TPEE resin, so that the fluorine-containing prepolymer reacts with TPEE resin under the action of the chain extender. For example, the carboxyl group of the fluorine-containing prepolymer reacts with the terminal hydroxyl group of TPEE resin, and the fluorine-containing prepolymer and TPEE resin also undergo transesterification reactions, etc., introducing fluoride into the TPEE molecular chain, making the fluoride have good dispersibility in TPEE resin, so that the obtained composite material has good appearance and significantly reduced pitting number. At the same time, it also enables the fluoride to better exert its efficacy, making the obtained composite material have better abrasion resistance and more excellent mechanical properties, such as high tensile strength.

[0017] Preferably, the fluorine-containing prepolymer includes at least one of the following compounds:

[0018] Perfluorobutylene glycol terephthalate, perfluoropentylene glycol terephthalate, perfluorodecylene glycol terephthalate, difluorobutylene glycol terephthalate, difluoropentylene glycol terephthalate.

[0019] When the fluorine-containing prepolymer includes at least one of the above compounds, the obtained material has better abrasion resistance and more excellent mechanical properties, such as high tensile strength.

[0020] Exemplarily, the preparation method of the fluorine-containing prepolymer includes the following steps: mixing fluorine-containing terephthalic acid, fluorine-containing diol, fluorine-containing carboxylic acid, a titanium-based catalyst and a solvent, heating to 240 - 260 °C under closed conditions and reacting at a constant temperature for 3 - 4 hours, then exhausting the gas in the system to atmospheric pressure, and continuing to react at 250 - 260 °C for 2 - 3 hours, cooling, and pulverizing to obtain the fluorine-containing prepolymer, wherein the weight ratio of fluorine-containing terephthalic acid, fluorine-containing diol, fluorine-containing carboxylic acid, tetrabutyl titanate and deionized water is (40 - 45):(38 - 43):(1 - 3):(0.5 - 1.5)):(5 - 10).

[0021] Exemplarily, the fluorine-containing terephthalic acid includes at least one of tetrafluoroterephthalic acid and 2,5-difluoroterephthalic acid; the fluorine-containing diol includes at least one of tetrafluoro-1,4-butanediol, perfluoro-1,10-decanediol, and hexafluoro-1,5-pentanediol; the fluorine-containing carboxylic acid includes at least one of perfluorohexanoic acid and perfluorobutyric acid; the titanium-based catalyst includes at least one of tetrabutyl titanate and tetraethyl titanate; the solvent includes at least one of deionized water and chloroform.

[0022] Preferably, the average particle size of the fluorine-containing prepolymer is less than 3 mm. For example, the average particle size of the fluorine-containing prepolymer is 2.8 mm, 2 mm, 1 mm, 0.5 mm, 0.1 mm, 0.05 mm, 0.01 mm, 5 μm, 1 μm, 0.5 μm, 0.1 μm, etc.

[0023] The average particle size of the fluorine-containing prepolymer can be measured by a laser particle size analyzer (Dv50).

[0024] The weight ratio of the TPEE resin to the fluorine-containing prepolymer is (17.8 - 99):1, such as 17.8:1, 18:1, 20:1, 30:1, 40:1, 50:1, 60:1, 70:1, 80:1, 90:1, 92:1, 95:1, 97:1, 99:1, etc. Preferably, the weight ratio of the TPEE resin to the fluorine-containing prepolymer is (30 - 72):1 to make the tensile strength, wear resistance and appearance balance of the composite material better.

[0025] Preferably, the chain extender includes at least one of pyromellitic dianhydride and diisocyanate. Exemplarily, the diisocyanate includes at least one of toluene diisocyanate, isophorone diisocyanate, diphenylmethane diisocyanate, and hexamethylene diisocyanate.

[0026] Preferably, the melt index of the TPEE resin under the conditions of 230 °C and 2.16 kg is 2 - 10 g / 10 min. The melt index of the TPEE resin under the conditions of 230 °C and 2.16 kg can be selected as 2 g / 10 min, 4 g / 10 min, 6 g / 10 min, 8 g / 10 min, or 10 g / 10 min, etc.

[0027] The melt index of the TPEE resin can be measured according to the ISO 1133-1-2011 standard.

[0028] Preferably, the weight percentage content of the TPEE resin in the TPEE composite material is above 91.7%, such as 91.7%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 98.5%.

[0029] Preferably, the TPEE resin is an extrusion-grade TPEE resin.

[0030] Preferably, it further includes the following components in parts by weight:

[0031] Antioxidant 0.2 - 0.5 parts,

[0032] Light stabilizer 0.3 - 0.6 parts.

[0033] Exemplarily, the antioxidant includes at least one of antioxidant 1010, antioxidant 1076, antioxidant 1790, antioxidant 168, antioxidant DLTP, and antioxidant 626.

[0034] Preferably, the light stabilizer includes at least one of hindered amine light stabilizers and triazine light stabilizers. More preferably, the light stabilizer includes hindered amine light stabilizers and triazine light stabilizers, and the weight ratio of the hindered amine light stabilizers to the triazine light stabilizers is 3:2. Exemplarily, the hindered amine light stabilizers include at least one of light stabilizer 622, light stabilizer 944, light stabilizer 783, light stabilizer 3853, light stabilizer 292, and light stabilizer 123; the triazine light stabilizers include at least one of UV-234, UV-236, and UV-237.

[0035] The TPEE composite material of the present application may contain common additives such as color powder, hydrolysis-resistant agents (such as carbodiimide, etc.), antistatic agents (such as polyether amide, polyether olefin, etc.) without compromising the effects of the present application.

[0036] In a second aspect, the present application provides a method for preparing the TPEE composite material, including the following steps:

[0037] Mix and disperse all raw materials, melt extrude, and granulate to obtain the TPEE composite material.

[0038] Preferably, the melt extrusion is carried out in a twin-screw extruder.

[0039] Preferably, the length-diameter ratio of the screw of the twin-screw extruder is ≥56:1. More preferably, the length-diameter ratio of the screw is 60:1.

[0040] Preferably, the screw rotation speed of the twin-screw extruder is 350 - 450 r / min, and the melt mixing temperature is 120 - 180 °C.

[0041] In a third aspect, the present application provides the application of the TPEE composite material in a kitchenware sealing system. Exemplarily, the TPEE composite material can be used to prepare sealing rings for ovens, dishwashers, etc.

[0042] Compared with the prior art, the beneficial effects of the present application are as follows: By adding a chain extender and a specific fluorine-containing prepolymer to the TPEE resin in the present application, the fluorine-containing prepolymer reacts with the TPEE resin under the action of the chain extender, introducing fluoride into the TPEE molecular chain, so that the fluoride has good dispersibility in the TPEE resin, thereby making the obtained composite material have good appearance, better wear resistance, and more excellent mechanical properties, such as high tensile strength, and is suitable as a material for sealing rings of kitchenware such as ovens and dishwashers. Specific embodiments

[0043] To better illustrate the purpose, technical solution and advantages of the present application, the present application will be further described below in conjunction with specific examples and comparative examples. The purpose is to understand the content of the present application in detail, rather than a limitation to the present application. All other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the protection scope of the present application. The experimental reagents and instruments involved in the implementation of the present application are all common ordinary reagents and instruments unless otherwise specified. In the present application, among the technically characterized described in an open-ended manner, it includes a closed technical solution composed of the listed features, and also includes an open-ended technical solution containing the listed features.

[0044] The raw material information used in the following examples and comparative examples is as shown below, and all are commercially available raw materials unless otherwise specified. In addition, the component raw materials used in each parallel experiment are the same.

[0045] TPEE Resin 1: Extrusion grade, the melt index measured according to the ISO 1133-1-2011 standard is 4 g / 10 min under the conditions of 230 °C and 2.16 kg, H45DBG, Jiangyin Hechuang;

[0046] TPEE Resin 2: Extrusion grade, the melt index measured according to the ISO 1133-1-2011 standard is 2 g / 10 min under the conditions of 230 °C and 2.16 kg, L4501, Keyilai;

[0047] TPEE Resin 3: Extrusion grade, the melt index measured according to the ISO 1133-1-2011 standard is 10 g / 10 min under the conditions of 230 °C and 2.16 kg, H45DMG, Jiangyin Hechuang;

[0048] Fluorine-containing prepolymer 1: Poly(tetrafluoroterephthaloyl perfluorobutanediol), a = 2, b = 4, c = 4, n = 80. The preparation method is as follows: Add fluorine-containing terephthalic acid, fluorine-containing diol, fluorine-containing carboxylic acid, tetrabutyl titanate and deionized water into the reaction kettle. Among them, the fluorine-containing terephthalic acid is tetrafluoroterephthalic acid, the fluorine-containing diol is tetrafluoro-1,4-butanediol, the fluorine-containing carboxylic acid is perfluorohexanoic acid, and the weight ratio of fluorine-containing terephthalic acid, fluorine-containing diol, fluorine-containing carboxylic acid, tetrabutyl titanate and deionized water is 40:38:2:1:10. After closing the kettle body, heat it to 250 °C and react for 3 hours. Then open the air release valve to remove water vapor and by-products to normal pressure, and then continue to react at 250 °C for 2 h. After the reaction is completed, cool it to room temperature, take out the product and crush it to obtain fluorine-containing prepolymer 1;

[0049] Fluorine-containing prepolymer 2: Poly(tetrafluoroterephthaloyl perfluoropentanediol), a = 3, b = 4, c = 4, n = 80. The difference in the preparation method from fluorine-containing prepolymer 1 is that the fluorine-containing diol is replaced by hexafluoro-1,5-pentanediol;

[0050] Fluorinated prepolymer 3: Poly(tetrafluoroterephthaloyl perfluorodecanediol), a = 8, b = 4, c = 4, n = 80. The preparation method is different from that of fluorinated prepolymer 1 in that the fluorinated diol is replaced with perfluoro-1,10-decanediol;

[0051] Fluorinated prepolymer 4: Poly(difluoroterephthaloyl perfluorobutanediol), a = 2, b = 4, c = 4, n = 60. The preparation method is different from that of fluorinated prepolymer 1 in that the weight ratio of fluorinated terephthalic acid, fluorinated diol, fluorinated carboxylic acid, tetrabutyl titanate and deionized water is adjusted to 40:37:3:1:10;

[0052] Fluorinated prepolymer 5: Poly(difluoroterephthaloyl perfluoropentanediol), a = 2, b = 4, c = 4, n = 90. The preparation method is different from that of fluorinated prepolymer 1 in that the weight ratio of fluorinated terephthalic acid, fluorinated diol, fluorinated carboxylic acid, tetrabutyl titanate and deionized water is adjusted to 40:39:1:1:10;

[0053] Polytetrafluoroethylene: FX-5911, 3M Company;

[0054] Chain extender 1: Pyromellitic dianhydride, Jisheng Chemical Industry;

[0055] Chain extender 2: Diphenylmethane diisocyanate, Shanghai Aladdin Biochemical Technology Co., Ltd.;

[0056] Antioxidant: Antioxidant 1076, commercially available;

[0057] Light stabilizer: A mixture of light stabilizer 944 and light stabilizer UV-234, the weight ratio of the two is 3:2, both are commercially available.

[0058] The following examples and comparative examples all provide a TPEE composite material, including the following steps: Mix and disperse all raw materials and then feed them into a twin-screw extruder for granulation to obtain the TPEE composite material;

[0059] Add a vacuum device in the tenth and thirteenth sections, and the vacuum degree is 0.8 MPa;

[0060] The length-diameter ratio of the screw of the twin-screw extruder is 60:1, the screw speed is 350 r / min, and the melting and mixing temperature is 200 °C.

[0061] The formulations of these TPEE composite materials in the examples and comparative examples are shown in Table 1 and Table 2, and the following performance tests are carried out on these TPEE composite materials:

[0062] Tensile strength: Test the tensile properties of the material according to ISO 527-2012 "Determination of Tensile Properties of Plastics" at 23 °C and a tensile rate of 50 mm / min;

[0063] Abrasion test: The wear and abrasion of the material are tested in accordance with ISO 4649:2017;

[0064] Extrusion appearance evaluation: Using a screw extruder, evaluate the appearance state of the extruded material. According to the number of pits larger than 0.5 mm in 10 cm 2 It is divided into the following four grades: severe (≥10), more (5 - 10), less (3 - 5), and few (<3).

[0065] Table 1

[0066]

[0067]

[0068] Table 2

[0069]

[0070] It can be seen from the above data that the materials of each example simultaneously have good appearance, excellent wear resistance and tensile strength. For example, the appearance pit grade is few or less, the abrasion is below 19%, and the tensile strength is above 40 MPa, which is suitable as a material for sealing rings of kitchen utensils such as ovens and dishwashers.

[0071] In Comparative Example 1, due to the lack of wear-resistant agent, the wear resistance is poor; in Comparative Example 2, a chain extender is added, but the fluorine-containing prepolymer is not added, and the wear resistance is poor; in Comparative Example 3, a fluorine-containing prepolymer is added, but the chain extender is not added. The reaction between the fluorine-containing prepolymer and TPEE is weak, and the fluoride cannot be effectively introduced into the TPEE molecular chain, resulting in poor dispersion of the fluorine-containing prepolymer in TPEE, more appearance pits, and poor wear resistance and tensile strength; in Comparative Example 4, a conventional fluoride wear-resistant agent, polytetrafluoroethylene, is added, and its dispersion in TPEE is poor, resulting in more appearance pits, and poor wear resistance and tensile strength.

[0072] Comparing Examples 1 - 5, it can be seen that when the weight ratio of TPEE resin to fluorine-containing prepolymer is in the range of (30 - 72):1, the wear resistance, tensile strength and appearance balance are better, which is more conducive to the preparation of kitchen utensil sealing rings.

[0073] Finally, it should be noted that the above examples are only used to illustrate the technical solutions of the present application rather than to limit the protection scope of the present application. Although the present application has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present application can be modified or equivalently replaced without departing from the essence and scope of the technical solutions of the present application.

Claims

1. A TPEE composite material, characterized in that: It comprises the following components in parts by weight: TPEE resin 89-99 parts; Chain extender 0.5-2 parts; 1 to 5 parts of fluorine-containing prepolymer; The fluorine-containing prepolymer comprises at least one of the compounds of formula I, Here, a is an integer of 2 to 8, b is an integer of 3 to 5, c is an integer of 2 to 4, and n is an integer of 60 to 90.

2. The TPEE composite material according to claim 1, characterized in that: The fluorine-containing prepolymer comprises at least one of the following compounds: Perfluorobutylene glycol polytetrafluoroterephthalate, perfluoropentane glycol polytetrafluoroterephthalate, perfluorodecane glycol polytetrafluoroterephthalate, perfluorobutylene glycol polydifluoroterephthalate, perfluoropentane glycol polydifluoroterephthalate.

3. The TPEE composite material according to claim 1, characterized in that: The weight ratio of the TPEE resin to the fluorine-containing prepolymer is (30-72):

1.

4. The TPEE composite material according to claim 1, characterized in that: The chain extender includes at least one of pyromellitic anhydride and diisocyanate.

5. The TPEE composite material according to claim 1, characterized in that: The TPEE resin has a melt index of 2 to 10 g / 10 min at 230° C. and 2.16 kg.

6. The TPEE composite material according to claim 1, characterized in that: The TPEE resin is an extrusion grade TPEE resin.

7. The TPEE composite material according to claim 1, characterized in that: Also includes the following components by weight: 0.2-0.5 parts of antioxidant, Light stabilizer 0.3-0.6 parts.

8. The method for preparing the TPEE composite material according to any one of claims 1 to 7, characterized in that: The following steps are involved: All raw materials are mixed and dispersed, melt-extruded, and granulated to obtain a TPEE composite material.

9. The method for preparing the TPEE composite material according to claim 8, characterized in that: The melt extrusion is carried out in a twin-screw extruder, the screw aspect ratio is (56-60):1, the screw speed is 350-450r / min, and the melt mixing temperature is 120-180°C.

10. Use of the TPEE composite material according to any one of claims 1 to 7 in a kitchenware sealing system.

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