TPEE composite material and preparation method and application thereof

Abstract

The invention discloses a TPEE composite material as well as a preparation method and application thereof, and belongs to the field of high polymer materials. According to the TPEE composite material disclosed by the invention, the chain extender and the specific fluorine-containing prepolymer are added into the TPEE resin, so that the fluorine-containing prepolymer and the TPEE resin react under the action of the chain extender, and fluoride is introduced into a TPEE molecular chain, so that the dispersity of the fluoride in the TPEE resin is good, and the obtained composite material is good in appearance, better in wear resistance and more excellent in mechanical property; the material is suitable for being used as a material for sealing rings of kitchenware such as ovens and dishwashers.

Description

Technical Field

[0001] The present application relates to the field of polymer materials, and specifically to a TPEE composite material and a preparation method and application thereof. Background Art

[0002] Thermoplastic polyester elastomer (TPEE) is often used in high-temperature oily environments because of its excellent elasticity, high temperature resistance and solvent resistance. The use environment of kitchenware sealing systems such as ovens and dishwashers is often accompanied by high temperature, high humidity, oil, etc., and the kitchenware needs to be opened and closed frequently, which requires high wear resistance of the material. Conventional TPV sealing rings have poor wear resistance and oil resistance, which is not as good as TPEE, and are not suitable for the above-mentioned kitchenware sealing systems. Conventional wear-resistant modified TPEE materials are accompanied by serious pitting problems during extrusion due to the poor dispersion of fillers and wear-resistant improvers in extrusion-grade TPEE.

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

[0004] Based on the defects of the prior art, the purpose of this application is to provide a TPEE composite material and its preparation method and application. 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] In order to achieve the above objectives, in a first aspect, the present application provides a TPEE composite material comprising the following components in parts by weight:

[0006] TPEE resin 89-99 parts;

[0007] Chain extender 0.5-2 parts;

[0008] 1 to 5 parts of fluorine-containing prepolymer;

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

[0010]

[0011] 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.

[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] The traditional method improves the wear resistance by adding fluorinated elastomers, polytetrafluoroethylene and other fluorinated wear resistant agents to TPEE resin, but these wear resistant agents have poor dispersibility in TPEE resin and are prone to pitting. The present application adds a chain extender and a specific fluorinated prepolymer to the TPEE resin so that the fluorinated prepolymer reacts with the TPEE resin under the action of the chain extender, such as the carboxyl group of the fluorinated prepolymer reacts with the terminal hydroxyl group of the TPEE resin, and the fluorinated prepolymer and the TPEE resin also undergo an ester exchange reaction, etc., to introduce fluoride into the TPEE molecular chain, so that the fluoride has good dispersibility in the TPEE resin, so that the resulting composite material has a good appearance and the number of pitting is significantly reduced, and at the same time, the fluoride can better exert its effect, so that the resulting composite material has better wear resistance and better mechanical properties, such as high tensile strength.

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

[0018] Perfluorobutylene glycol polytetrafluoroterephthalate, perfluoropentane glycol polytetrafluoroterephthalate, perfluorodecane glycol polytetrafluoroterephthalate, perfluorobutylene glycol polydifluoroterephthalate, perfluoropentane glycol polydifluoroterephthalate.

[0019] When the fluorine-containing prepolymer includes at least one of the above compounds, the obtained material has better wear 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 venting the gas in the system to normal pressure, continuing to react at 250-260°C for 2-3 hours, cooling, and crushing to obtain the fluorine-containing prepolymer, wherein the weight ratio of fluorine-containing terephthalic acid, fluorine-containing diol, fluorine-containing carboxylic acid, butyl titanate and deionized water is (40-45):(38-43):(1-3):(0.5-1.5)):(5-10).

[0021] Exemplarily, the fluorinated terephthalic acid includes at least one of tetrafluoroterephthalic acid and 2,5-difluoroterephthalic acid; the fluorinated diol includes at least one of tetrafluoro-1,4-butanediol, perfluoro-1,10-decanediol, and hexafluoro-1,5-pentanediol; the fluorinated carboxylic acid includes at least one of perfluorohexanoic acid and perfluorobutyric acid; the titanium-based catalyst includes at least one of butyl titanate and ethyl titanate; and 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 or 0.1 μm.

[0023] The average particle size of the fluorine-containing prepolymer can be measured using a laser particle size tester (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, so that the tensile strength, wear resistance and appearance of the composite material are better balanced.

[0025] Preferably, the chain extender includes at least one of pyromellitic anhydride 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 at 230°C and 2.16kg is 2 to 10g / 10min. The melt index of the TPEE resin at 230°C and 2.16kg can be 2g / 10min, 4g / 10min, 6g / 10min, 8g / 10min or 10g / 10min, etc.

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

[0028] Preferably, the weight percentage 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 extrusion grade TPEE resin.

[0030] Preferably, the following components in parts by weight are also included:

[0031] 0.2-0.5 parts of antioxidant,

[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 a hindered amine light stabilizer and a triazine light stabilizer. More preferably, the light stabilizer includes a hindered amine light stabilizer and a triazine light stabilizer, and the weight ratio of the hindered amine light stabilizer to the triazine light stabilizer is 3:2. Exemplarily, the hindered amine light stabilizer includes 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 stabilizer includes at least one of UV-234, UV-236, and UV-237.

[0035] The TPEE composite material described in the present application may contain common additives such as color powder, anti-hydrolysis agent (such as carbodiimide, etc.), antistatic agent (such as polyether amide, polyether olefin, etc.) without damaging the effect of the present application.

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

[0037] All raw materials are mixed and dispersed, melt-extruded, and granulated to obtain a TPEE composite material.

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

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

[0040] Preferably, the screw 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 an application of the TPEE composite material in a kitchenware sealing system. For example, the TPEE composite material can be used to prepare sealing rings for ovens, dishwashers, and the like.

[0042] Compared with the prior art, the beneficial effect of the present application is that: the present application adds 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, introduces fluoride into the TPEE molecular chain, and makes the fluoride well dispersed in the TPEE resin, so that the obtained composite material has good appearance, better wear resistance, and better mechanical properties, such as high tensile strength, and is suitable as a material for sealing rings of kitchen utensils such as ovens and dishwashers. DETAILED DESCRIPTION

[0043] In order to better illustrate the purpose, technical scheme and advantages of the present application, the present application will be further described below in conjunction with specific embodiments and comparative examples, the purpose of which is to understand the content of the present application in detail, rather than to limit the present application. All other embodiments obtained by ordinary technicians in the field without making creative work are within the scope of protection of the present application. The experimental reagents and instruments involved in the implementation of this application are all commonly used ordinary reagents and instruments unless otherwise specified. In the present application, the technical features described in an open manner include closed technical schemes composed of the listed features, and also include open technical schemes containing the listed features.

[0044] The raw materials used in the following examples and comparative examples are as follows, and unless otherwise specified, they are all commercially available raw materials. In addition, the component raw materials used in each parallel experiment are all of the same kind.

[0045] TPEE resin 1: extrusion grade, melt index measured according to ISO 1133-1-2011 standard is 4g / 10min at 230℃ and 2.16kg, H45DBG, Jiangyin Hechuang;

[0046] TPEE resin 2: extrusion grade, melt index measured according to ISO 1133-1-2011 standard is 2g / 10min at 230℃ and 2.16kg, L4501, Keyile;

[0047] TPEE resin 3: extrusion grade, melt index measured according to ISO 1133-1-2011 standard is 10g / 10min at 230℃ and 2.16kg, H45DMG, Jiangyin Hechuang;

[0048] Fluorine-containing prepolymer 1: polytetrafluoroterephthalate perfluorobutylene glycol ester, 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, butyl titanate and deionized water into a reaction kettle, wherein 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, butyl titanate and deionized water is 40:38:2:1:10, after sealing the kettle body, heating to 250°C, reacting for 3 hours, then opening the vent valve to exhaust water and by-products to normal pressure, and then continuing to react at 250°C for 2 hours, cooling to room temperature after the reaction is completed, taking out the product, and crushing it to obtain fluorine-containing prepolymer 1;

[0049] Fluorinated prepolymer 2: polytetrafluoropentanediol terephthalate, a=3, b=4, c=4, n=80, the preparation method is different from that of fluorinated prepolymer 1 in that the fluorinated diol is replaced by hexafluoro-1,5-pentanediol;

[0050] Fluorinated prepolymer 3: polytetrafluoroterephthalate perfluorodecanediol ester, 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 by perfluoro-1,10-decanediol;

[0051] Fluorinated prepolymer 4: poly(difluorobutylene terephthalate), 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, butyl titanate and deionized water is adjusted to 40:37:3:1:10;

[0052] Fluorinated prepolymer 5: polydifluoropentanediol terephthalate, 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, butyl titanate and deionized water is adjusted to 40:39:1:1:10;

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

[0054] Chain extender 1: pyromellitic anhydride, Jisheng Chemical;

[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, with a weight ratio of 3:2, both of which are commercially available.

[0058] Each of the following embodiments and comparative examples provides a TPEE composite material, comprising the following steps: mixing and dispersing all raw materials and feeding them into a twin-screw extruder for granulation to obtain a TPEE composite material;

[0059] Add vacuum devices in the tenth and thirteenth sections, with a vacuum degree of 0.8MPa;

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

[0061] The formulas of the TPEE composite materials of these embodiments and comparative examples are shown in Tables 1 and 2, and the following performance tests are performed on these TPEE composite materials:

[0062] Tensile strength: The tensile properties of the material are tested according to ISO 527-2012 "Determination of tensile properties of plastics", 23°C, and the tensile rate is 50 mm / min;

[0063] Abrasion test: Test material wear and tear according to ISO 4649:2017;

[0064] Extrusion appearance evaluation: Use a screw extruder to evaluate the appearance of the extruded material, based on a 10cm 2 The number of pits larger than 0.5 mm is divided into the following four levels: severe (≥10), more (5-10), less (3-5), and fewer (<3).

[0065] Table 1

[0066]

[0067]

[0068] Table 2

[0069]

[0070] It can be seen from the above data that the materials of each embodiment have good appearance, excellent wear resistance and tensile strength, such as the appearance pitting level is few or less, the wear is below 19%, and the tensile strength is above 40MPa. It is suitable as a material for kitchenware sealing rings such as ovens and dishwashers.

[0071] Comparative Example 1 has a deviation in wear resistance because no anti-wear agent is added; Comparative Example 2 adds a chain extender but no fluorinated prepolymer is added, so the wear resistance is deviated; Comparative Example 3 adds a fluorinated prepolymer but no chain extender, and the reaction between the fluorinated prepolymer and TPEE is weak, and the fluoride cannot be effectively introduced into the TPEE molecular chain, resulting in poor dispersion of the fluorinated prepolymer in TPEE, more pitting on the appearance, and deviations in wear resistance and tensile strength; Comparative Example 4 adds a conventional fluoride wear-resistant agent, polytetrafluoroethylene, which has poor dispersion in TPEE, resulting in more pitting on the appearance, and deviations in wear resistance and tensile strength.

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

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