Compatibilizers, thermoplastic elastomer compositions, thermoplastic elastomers, and methods of making and using the same

Abstract

This invention relates to the field of thermoplastic elastomer materials, and discloses a compatibilizer, an EPDM / PP thermoplastic elastomer composition, an EPDM / PP thermoplastic elastomer, its preparation method, and its applications. The compatibilizer of this invention contains a co-grafted compound of maleic anhydride with polypropylene and ethylene propylene diene monomer (PP-MAH-EPDM). By using a specific PP-MAH-EPDM compatibilizer, this invention improves the compatibility of EPDM / PP, resulting in a significant increase in the elongation at break and a substantial improvement in compression set of the prepared EPDM / PP TPV.

Description

Technical Field

[0001] This invention relates to the field of thermoplastic elastomer materials, specifically to a compatibilizer, an EPDM / PP thermoplastic elastomer composition, an EPDM / PP thermoplastic elastomer, its preparation method, and its application. Background Technology

[0002] EPDM / PP thermoplastic elastomers were among the first thermoplastic elastomers to enter the market. They possess excellent physical properties and can be processed using thermoplastic plastic processing equipment and techniques, making them widely used in industries such as household appliances, wires and cables, construction, and automobiles. With their expanding applications, EPDM / PP TPV, as "third-generation rubber," is gradually replacing traditional rubber. However, its relatively low tensile strength and high compression set limit its application range.

[0003] The literature (Zhu Xu et al., Effect of N,N'-m-phenyl bismaleimide on the properties of EPDM / polypropylene thermoplastic vulcanizate; Plastics Industry, 2017, Vol. 45, No. 8: 113-116) studied the effects of the addition of vulcanizing agent N,N'-m-phenyl bismaleimide (PDM) and initiator 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane on the vulcanization characteristics, tensile properties, compression set, gel content, and microstructure of TPV. The results showed that with the increase of vulcanizing agent dosage, the required vulcanization time of TPV compound was shortened, the vulcanization rate was accelerated, the compression set was reduced, and the gel content was increased, but its tensile strength was lower.

[0004] CN101597378A discloses a method for preparing thermoplastic dynamic vulcanized rubber. The specific operation steps are as follows: (1) Ethylene propylene diene monomer (EPDM) rubber, polypropylene, talc powder, and antioxidant 1010 are mixed evenly in a high-speed mixer and then melt-blended in a twin-screw extruder at 180°C, while simultaneously filling with naphthenic oil softener through a liquid filling port; (2) The product of (1), tert-octylphenolic resin vulcanizing agent, and stannous chloride are mixed evenly in a high-speed mixer and then dynamically vulcanized in a twin-screw extruder at 180°C, while simultaneously filling with naphthenic oil softener; (3) The product of (2) and black masterbatch are mixed evenly in a high-speed mixer and then melt-extruded in a twin-screw extruder at 180°C, while simultaneously filling with naphthenic oil softener. In this preparation method, the amount of tert-octylphenolic resin vulcanizing agent is as high as 7%. The dynamically vulcanized thermoplastic elastomer material prepared by this method has low elongation at break, rough surface, and poor processing performance. Summary of the Invention

[0005] The purpose of this invention is to overcome the problems in existing EPDM / PP TPV preparation technologies, such as poor EPDM / PP compatibility when the viscosity of EPDM and PP is relatively high, resulting in low elongation at break and high compression set of the prepared TPV material. This invention provides a compatibilizer, an EPDM / PP thermoplastic elastomer composition, an EPDM / PP thermoplastic elastomer, its preparation method, and its applications. By using a specific maleic anhydride co-grafted polypropylene and EPDM rubber (hereinafter also referred to as PP-MAH-EPDM) compatibilizer, the compatibility of EPDM / PP is improved, resulting in a significant increase in the elongation at break and a substantial improvement in compression set of the prepared EPDM / PP TPV.

[0006] To achieve the above objectives, a first aspect of the present invention provides a compatibilizer, wherein the compatibilizer contains a co-graft of maleic anhydride with polypropylene and ethylene propylene diene monomer (EPDM) rubber.

[0007] Preferably, the compatibilizer is a co-grafted compound of maleic anhydride with polypropylene and ethylene propylene diene monomer (EPDM) rubber.

[0008] Preferably, the maleic anhydride-polypropylene and EPDM co-grafted compound is obtained by subjecting maleic anhydride-grafted polypropylene to EPDM via a Diels-Alder reaction in the presence of a Lewis acid.

[0009] Preferably, the Lewis acid is one or more of stannous chloride, zinc chloride, and aluminum trichloride.

[0010] Preferably, the amount of Lewis acid used is 0.3-0.8 parts by weight per 100 parts by weight of EPDM.

[0011] Preferably, the amount of maleic anhydride-grafted polypropylene used is 0.5-1 parts by weight per 100 parts by weight of EPDM.

[0012] Preferably, the conditions for the Diels-Alder reaction include: a reaction temperature of 150-160°C and a reaction time of 3-5 min.

[0013] Preferably, the grafting rate of the maleic anhydride-grafted polypropylene is 0.6-1%.

[0014] According to a second aspect of the present invention, an EPDM / PP thermoplastic elastomer composition is provided, the composition comprising EPDM, PP, a compatibilizer, optionally a solvent oil, optionally an inorganic filler, a vulcanizing agent, and an antioxidant, wherein the compatibilizer is the compatibilizer described in the first aspect of the present invention.

[0015] Preferably, based on 100 parts by weight of the composition, the composition contains 20-60 parts by weight of EPDM, 10-50 parts by weight of PP, 0.9-3 parts by weight of compatibilizer, 0-40 parts by weight of solvent oil, 0-15 parts by weight of inorganic filler, 0.5-3 parts by weight of vulcanizing agent, and 0.2-0.6 parts by weight of antioxidant; more preferably, the composition contains 30-50 parts by weight of EPDM, 10-30 parts by weight of PP, 1-3 parts by weight of compatibilizer, 10-38 parts by weight of solvent oil, 1-12 parts by weight of inorganic filler, 0.5-2.5 parts by weight of vulcanizing agent, and 0.2-0.6 parts by weight of antioxidant. The composition contains 5 parts by weight of antioxidant; more preferably, the composition contains 35-40 parts by weight of EPDM, 10-20 parts by weight of PP, 1-2 parts by weight of compatibilizer, 20-35 parts by weight of solvent oil, 3-10 parts by weight of inorganic filler, 0.5-2 parts by weight of vulcanizing agent, and 0.2-0.4 parts by weight of antioxidant; more preferably, the composition contains 38-40 parts by weight of EPDM, 10-15 parts by weight of PP, 1.2-1.6 parts by weight of compatibilizer, 30-35 parts by weight of solvent oil, 5-10 parts by weight of inorganic filler, 0.7-1 parts by weight of vulcanizing agent, and 0.3-0.4 parts by weight of antioxidant.

[0016] Preferably, based on the total weight of the EPDM, the content of ethylene structural units in the EPDM is 40-70% by weight, and the content of the third monomer is 4-10% by weight.

[0017] Preferably, the third monomer is one or more of 1,4-hexadiene, dicyclopentadiene (DCPD), and 5-ethylidene-2-norbornene.

[0018] Preferably, the weight-average molecular weight of the EPDM is 100,000 to 400,000.

[0019] Preferably, the PP is homopolymer polypropylene and / or random copolymer polypropylene.

[0020] Preferably, the melt flow index of the PP at a temperature of 230°C and a load of 2.16 kg is 1-20 g / 10 min.

[0021] Preferably, the solvent oil is one or more of environmentally friendly paraffin oil, naphthenic oil, and environmentally friendly aromatic oil.

[0022] Preferably, the inorganic filler is one or more of silica, calcium carbonate and talc, and more preferably silica.

[0023] Preferably, the vulcanizing agent is a peroxide vulcanizing agent; more preferably, the vulcanizing agent is one or more of benzoyl peroxide, 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane and tert-butyl peroxyisopropyl carbonate, and even more preferably tert-butyl peroxyisopropyl carbonate.

[0024] Preferably, the antioxidant is one or more of amine antioxidants, quinoline antioxidants, and benzimidazole antioxidants.

[0025] Preferably, the composition further contains other components such as a release agent and / or an anti-UV agent.

[0026] Preferably, based on 100 parts by weight of the composition, the content of the other components is 0.3-0.4 parts by weight.

[0027] According to a third aspect of the present invention, an EPDM / PP thermoplastic elastomer is provided, which is formed from the EPDM / PP thermoplastic elastomer composition described in the second aspect of the present invention.

[0028] According to a fourth aspect of the present invention, a method for preparing an EPDM / PP thermoplastic elastomer is provided, wherein the method uses the EPDM / PP thermoplastic elastomer composition described in the second aspect of the present invention, and includes the following steps:

[0029] 1) The EPDM, PP, compatibilizer, optional solvent oil, optional inorganic filler and antioxidant are extruded and granulated to obtain rubber-plastic blend masterbatch;

[0030] 2) Dynamically vulcanize the rubber-plastic blend masterbatch obtained in step 1) with the vulcanizing agent.

[0031] Preferably, the dynamic vulcanization includes: feeding the rubber-plastic blend masterbatch and the vulcanizing agent into a twin-screw extruder for dynamic vulcanization, and then extruding and granulating them.

[0032] Preferably, the conditions for dynamic vulcanization include: a dynamic vulcanization temperature of 190-200℃, a dynamic vulcanization time of 2-2.5 min, and a rotation speed of 200-300 rpm.

[0033] According to a fifth aspect of the present invention, an EPDM / PP thermoplastic elastomer is provided, which is prepared by the preparation method of the EPDM / PP thermoplastic elastomer described in the fourth aspect of the present invention.

[0034] According to a sixth aspect of the present invention, the thermoplastic elastomer described in the third and fifth aspects of the present invention is provided for use in the manufacture of wires and cables, building materials, automotive seals and interior trim or household appliances.

[0035] Through the above technical solution, the present invention improves the compatibility of EPDM / PP by using a specific PP-MAH-EPDM compatibilizer, and the elongation at break of the prepared EPDM / PP TPV is greatly improved, and the compression set is greatly reduced. Detailed Implementation

[0036] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0037] According to a first aspect of the present invention, a compatibilizer is provided, wherein the compatibilizer contains PP-MAH-EPDM.

[0038] In this invention, PP-MAH-EPDM refers to maleic anhydride-grafted polypropylene grafted with ethylene propylene diene monomer (EPDM). Specifically, maleic anhydride is first grafted onto polypropylene to obtain maleic anhydride-grafted polypropylene (PP-g-MAH), and then EPDM is grafted with the PP-g-MAH to obtain maleic anhydride-grafted polypropylene grafted with EPDM.

[0039] The aforementioned maleic anhydride-grafted polypropylene can be commercially available or prepared using conventional synthetic methods in the art.

[0040] For example, polypropylene (PP), maleic anhydride (MAH), and dicumyl peroxide (DCP) can be added to a twin-screw extruder for melt extrusion while simultaneously grafting to obtain the PP-g-MAH.

[0041] In the above embodiments, based on 100 parts by weight of PP, the amount of maleic anhydride can be 2-4 parts by weight, and the amount of dicumyl peroxide can be 0.2-0.4 parts by weight.

[0042] Furthermore, after obtaining the PP-g-MAH through melt extrusion, it is preferable to granulate the melt-grafted PP-g-MAH to facilitate grafting onto the EPDM. Granulation can be carried out using methods commonly used in the art, such as underwater pelletizing.

[0043] According to the present invention, the grafting rate of the maleic anhydride-grafted polypropylene can be 0.6-1%, preferably 0.8-1%, and particularly preferably 1%.

[0044] According to the present invention, preferably, the PP-MAH-EPDM is obtained by subjecting maleic anhydride-grafted polypropylene to EPDM in the presence of a Lewis acid via a Diels-Alder reaction.

[0045] Preferably, the Lewis acid is one or more of stannous chloride, zinc chloride, and aluminum trichloride; more preferably, the Lewis acid is stannous chloride. Stannous chloride dihydrate can be used as an example of the stannous chloride.

[0046] Preferably, the amount of Lewis acid is 0.3-0.8 parts by weight per 100 parts by weight of EPDM; more preferably, the amount of Lewis acid is 0.4-0.6 parts by weight per 100 parts by weight of EPDM.

[0047] Preferably, the amount of maleic anhydride-grafted polypropylene used is 0.5-1 parts by weight per 100 parts by weight of EPDM; more preferably, the amount of maleic anhydride-grafted polypropylene used is 0.7-0.9 parts by weight per 100 parts by weight of EPDM.

[0048] Preferably, the conditions for the Diels-Alder reaction include: a reaction temperature of 150-160°C and a reaction time of 3-5 min.

[0049] According to a second aspect of the present invention, an EPDM / PP thermoplastic elastomer composition is provided, wherein the composition contains EPDM, PP, a compatibilizer, optionally a solvent oil, optionally an inorganic filler, a vulcanizing agent, and an antioxidant, wherein the compatibilizer is the compatibilizer of the first aspect of the present invention.

[0050] In this invention, the compatibilizer contains PP-MAH-EPDM. Although, in addition to containing PP-MAH-EPDM, the composition may also contain various compatibilizers commonly used in the art to promote the compatibility of PP and EPDM, without affecting the effectiveness of this invention, since the effect of using PP-MAH-EPDM is superior to other conventional compatibilizers, it is preferred in this invention that the higher the content of PP-MAH-EPDM as a compatibilizer, the better, and PP-MAH-EPDM is particularly preferred as the compatibilizer.

[0051] In this invention, based on 100 parts by weight of the composition, the composition contains 20-60 parts by weight of EPDM, 10-50 parts by weight of PP, 0.9-3 parts by weight of compatibilizer, 0-40 parts by weight of solvent oil, 0-15 parts by weight of inorganic filler, 0.5-3 parts by weight of vulcanizing agent, and 0.2-0.6 parts by weight of antioxidant; preferably, the composition contains 30-50 parts by weight of EPDM, 10-30 parts by weight of PP, 1-3 parts by weight of compatibilizer, 10-38 parts by weight of solvent oil, 1-12 parts by weight of inorganic filler, 0.5-2.5 parts by weight of vulcanizing agent, and 0.2-0.6 parts by weight of antioxidant. The composition contains 5 parts by weight of antioxidant; more preferably, the composition contains 35-40 parts by weight of EPDM, 10-20 parts by weight of PP, 1-2 parts by weight of compatibilizer, 20-35 parts by weight of solvent oil, 3-10 parts by weight of inorganic filler, 0.5-2 parts by weight of vulcanizing agent, and 0.2-0.4 parts by weight of antioxidant; more preferably, the composition contains 38-40 parts by weight of EPDM, 10-15 parts by weight of PP, 1.2-1.6 parts by weight of compatibilizer, 30-35 parts by weight of solvent oil, 5-10 parts by weight of inorganic filler, 0.7-1 parts by weight of vulcanizing agent, and 0.3-0.4 parts by weight of antioxidant.

[0052] Specific examples of the EPDM content include, for instance, 20 parts by weight, 21 parts by weight, 22 parts by weight, 23 parts by weight, 24 parts by weight, 25 parts by weight, 26 parts by weight, 27 parts by weight, 28 parts by weight, 29 parts by weight, 30 parts by weight, 31 parts by weight, 32 parts by weight, 33 parts by weight, 34 parts by weight, 35 parts by weight, 3 parts by weight, 37 parts by weight, 38 parts by weight, 39 parts by weight, 40 parts by weight, 41 parts by weight, 42 parts by weight, 43 parts by weight, 44 parts by weight, 45 parts by weight, 46 parts by weight, 47 parts by weight, 48 parts by weight, 49 parts by weight, 50 parts by weight, 51 parts by weight, 52 parts by weight, 53 parts by weight, 54 parts by weight, 55 parts by weight, 56 parts by weight, 57 parts by weight, 58 parts by weight, 59 parts by weight, 60 parts by weight, etc., and any range formed by any two of these values.

[0053] Specific examples of the PP content include, for instance, 10 parts by weight, 11 parts by weight, 12 parts by weight, 13 parts by weight, 14 parts by weight, 15 parts by weight, 16 parts by weight, 17 parts by weight, 18 parts by weight, 19 parts by weight, 20 parts by weight, 21 parts by weight, 22 parts by weight, 23 parts by weight, 24 parts by weight, 25 parts by weight, 26 parts by weight, 27 parts by weight, 28 parts by weight, 29 parts by weight, 30 parts by weight, 31 parts by weight, 32 parts by weight, 33 parts by weight, 34 parts by weight, 35 parts by weight, 3 parts by weight, 37 parts by weight, 38 parts by weight, 39 parts by weight, 40 parts by weight, 41 parts by weight, 42 parts by weight, 43 parts by weight, 44 parts by weight, 45 parts by weight, 46 parts by weight, 47 parts by weight, 48 parts by weight, 49 parts by weight, 50 parts by weight, etc., and any range formed by any two of these values.

[0054] Specific examples of the compatibilizer content include, for example, 0.9 parts by weight, 1 part by weight, 1.1 parts by weight, 1.2 parts by weight, 1.3 parts by weight, 1.4 parts by weight, 1.5 parts by weight, 1.6 parts by weight, 1.7 parts by weight, 1.8 parts by weight, 1.9 parts by weight, 2 parts by weight, 2.1 parts by weight, 2.2 parts by weight, 2.3 parts by weight, 2.4 parts by weight, 2.5 parts by weight, 2.6 parts by weight, 2.7 parts by weight, 2.8 parts by weight, 2.9 parts by weight, 3 parts by weight, etc., and any range of any two of these values.

[0055] Specific examples of the content of the solvent oil include, for example, 1 part by weight, 2 parts by weight, 3 parts by weight, 4 parts by weight, 5 parts by weight, 6 parts by weight, 7 parts by weight, 8 parts by weight, 9 parts by weight, 10 parts by weight, 11 parts by weight, 12 parts by weight, 13 parts by weight, 14 parts by weight, 15 parts by weight, 16 parts by weight, 17 parts by weight, 18 parts by weight, 19 parts by weight, 20 parts by weight, 21 parts by weight, 22 parts by weight, 23 parts by weight, 24 parts by weight, 25 parts by weight, 26 parts by weight, 27 parts by weight, 28 parts by weight, 29 parts by weight, 30 parts by weight, 31 parts by weight, 32 parts by weight, 33 parts by weight, 34 parts by weight, 35 parts by weight, 3 parts by weight, 37 parts by weight, 38 parts by weight, 39 parts by weight, 40 parts by weight, etc., and any range formed by any two of these values.

[0056] Specific examples of the content of the inorganic filler include, for example, 1 part by weight, 2 parts by weight, 3 parts by weight, 4 parts by weight, 5 parts by weight, 6 parts by weight, 7 parts by weight, 8 parts by weight, 9 parts by weight, 10 parts by weight, 11 parts by weight, 12 parts by weight, 13 parts by weight, 14 parts by weight, 15 parts by weight, etc., and any range of any two of these values.

[0057] Specific examples of the content of the vulcanizing agent include, for example, 0.5 parts by weight, 0.6 parts by weight, 0.7 parts by weight, 0.8 parts by weight, 0.9 parts by weight, 1 part by weight, 1.1 parts by weight, 1.2 parts by weight, 1.3 parts by weight, 1.4 parts by weight, 1.5 parts by weight, 1.6 parts by weight, 1.7 parts by weight, 1.8 parts by weight, 1.9 parts by weight, 2 parts by weight, 2.1 parts by weight, 2.2 parts by weight, 2.3 parts by weight, 2.4 parts by weight, 2.5 parts by weight, 2.6 parts by weight, 2.7 parts by weight, 2.8 parts by weight, 2.9 parts by weight, 3 parts by weight, etc., and any range of any two of these values.

[0058] Specific examples of the antioxidant content include: 0.2 parts by weight, 0.21 parts by weight, 0.22 parts by weight, 0.23 parts by weight, 0.24 parts by weight, 0.25 parts by weight, 0.26 parts by weight, 0.27 parts by weight, 0.28 parts by weight, 0.29 parts by weight, 0.3 parts by weight, 0.31 parts by weight, 0.32 parts by weight, 0.33 parts by weight, 0.34 parts by weight, 0.35 parts by weight, 0.36 parts by weight, 0.37 parts by weight, 0.38 parts by weight, 0.39 parts by weight, 0... 0.4 parts by weight, 0.41 parts by weight, 0.42 parts by weight, 0.43 parts by weight, 0.44 parts by weight, 0.45 parts by weight, 0.46 parts by weight, 0.47 parts by weight, 0.48 parts by weight, 0.49 parts by weight, 0.5 parts by weight, 0.51 parts by weight, 0.52 parts by weight, 0.53 parts by weight, 0.54 parts by weight, 0.55 parts by weight, 0.56 parts by weight, 0.57 parts by weight, 0.58 parts by weight, 0.59 parts by weight, 0.6 parts by weight, etc., and the range formed by any two of these values.

[0059] According to the present invention, the EPDM can be any of the EPDM commonly used in the art. For example, based on the total weight of the EPDM, the EPDM contains 50-70% by weight of ethylene structural units and 4-6% by weight of a third monomer. The weight-average molecular weight of the EPDM is 100,000-400,000. The third monomer can be any of the third monomers commonly used in the art, such as one or more of 1,4-hexadiene, dicyclopentadiene (DCPD), and 5-ethylidene-2-norbornene, preferably 5-ethylidene-2-norbornene (ENB).

[0060] According to the present invention, the PP is homopolymer polypropylene and / or random copolymer polypropylene, and the melt index of the PP at 230°C and under a load of 2.16 kg is 1-20 g / 10 min. To further improve the mechanical properties of the vulcanized rubber, preferably, the comonomer of the random copolymer polypropylene is ethylene.

[0061] According to the present invention, preferably, the solvent oil is one or more of environmentally friendly paraffin oil, naphthenic oil and environmentally friendly aromatic oil; preferably, the solvent oil is environmentally friendly paraffin oil.

[0062] According to the present invention, preferably, the inorganic filler can be one or more of silica, calcium carbonate and talc; more preferably, the inorganic filler is silica.

[0063] According to the present invention, preferably, the vulcanizing agent is a peroxide vulcanizing agent; more preferably, the vulcanizing agent is one or more of benzoyl peroxide, 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane and tert-butyl peroxyisopropyl carbonate; and even more preferably, the vulcanizing agent is tert-butyl peroxyisopropyl carbonate.

[0064] According to the present invention, the antioxidant can be one or more of amine antioxidants, quinoline antioxidants, and benzimidazole antioxidants. Specifically, the amine antioxidant is a naphthylamine antioxidant and / or a p-phenylenediamine antioxidant. More specifically, the naphthylamine antioxidant is naphthylamine and its derivatives; the p-phenylenediamine antioxidant is p-phenylenediamine and its derivatives; the quinoline antioxidant is quinoline and its derivatives, such as 2,2,4-trimethyl-1,2-dihydroquinoline; and the benzimidazole antioxidant is benzimidazole and its derivatives, such as 2-mercaptobenzimidazole. More preferably, the antioxidant is pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] (antioxidant 1010).

[0065] According to the present invention, without affecting the effects of the present invention, the composition of the present invention preferably also contains other components such as a release agent and / or an anti-ultraviolet agent.

[0066] The content of the other components can be the content commonly used in the art, for example, based on 100 parts by weight of the composition, the content of the other components is 0.3-0.4 parts by weight.

[0067] According to a third aspect of the present invention, an EPDM / PP thermoplastic elastomer is provided, which is formed from the EPDM / PP thermoplastic elastomer composition described in the second aspect of the present invention.

[0068] According to the present invention, the method for molding the EPDM / PP thermoplastic elastomer composition of the present invention into the EPDM / PP thermoplastic elastomer of the present invention is not particularly limited, and can be carried out using various molding equipment and molding conditions commonly used in the art.

[0069] According to a fourth aspect of the present invention, a method for preparing an EPDM / PP thermoplastic elastomer is provided, wherein the method uses the EPDM / PP thermoplastic elastomer composition described in the second aspect of the present invention, and includes the following steps:

[0070] 1) The EPDM, PP, compatibilizer, optional solvent oil, optional inorganic filler and antioxidant are extruded and granulated to obtain rubber-plastic blend masterbatch;

[0071] 2) Dynamically vulcanize the rubber-plastic blend masterbatch obtained in step 1) with the vulcanizing agent.

[0072] According to the present invention, preferably, in step 1), the EPDM, the PP, the compatibilizer, the optional solvent oil, the optional inorganic filler, and the antioxidant are fed into a twin-screw extruder for extrusion to obtain the rubber-plastic blend masterbatch. Here, the twin-screw extruder temperature can be 170-200°C, the speed can be 200-300 rpm, and the residence time can be 1-2 min.

[0073] According to the present invention, preferably, in step 2), the dynamic vulcanization includes: feeding the rubber-plastic blend masterbatch and the vulcanizing agent into a twin-screw extruder for dynamic vulcanization, and then extruding and granulating.

[0074] Preferably, the conditions for dynamic vulcanization include: a dynamic vulcanization temperature of 190-200℃, a dynamic vulcanization time of 2-2.5 min, and a rotation speed of 200-300 rpm.

[0075] In a particularly preferred embodiment of the present invention, the EPDM / PP thermoplastic elastomer is prepared according to the following method:

[0076] 1) The EPDM, PP, compatibilizer, optional solvent oil, optional inorganic filler and antioxidant are fed into a twin-screw extruder and extruded to obtain the rubber-plastic blend masterbatch, wherein the temperature of the twin-screw extruder is 170-200℃, the speed is 200-300rpm, and the residence time is 1-2min;

[0077] 2) The rubber-plastic blend masterbatch and the vulcanizing agent are fed into a twin-screw extruder for dynamic vulcanization and extrusion granulation; wherein, the dynamic vulcanization conditions include: twin-screw extruder ￠=35mm L / D=64; dynamic vulcanization temperature is 190-200℃; dynamic vulcanization time is 2-2.5min; and rotation speed is 200-300rpm.

[0078] According to a fifth aspect of the present invention, an EPDM / PP thermoplastic elastomer is provided, which is prepared by the preparation method of the EPDM / PP thermoplastic elastomer described in the fourth aspect of the present invention.

[0079] According to a sixth aspect of the present invention, the thermoplastic elastomer described in the third or fifth aspect of the present invention is provided for use in the manufacture of wires and cables, building materials, automotive seals and interior trim or household appliances.

[0080] The EPDM / PP thermoplastic elastomer of the present invention improves the interfacial compatibility of high viscosity ratio EPDM / PP by using PP-MAH-EPDM compatibilizer, resulting in a significant increase in the elongation at break and a substantial improvement in compression set of the prepared EPDM / PP TPV. This greatly expands the application range of EPDM / PP TPV materials, which can be widely used in industries such as automobiles, home appliances, wires and cables, and construction.

[0081] The present invention will be described in detail below through embodiments, but the present invention is not limited to the following embodiments.

[0082] Preparation Examples 1-5

[0083] Preparation Examples 1-5: PP-MAH-EPDM compatibilizers were prepared according to the following preparation methods and the amounts shown in Table 1.

[0084] 1) Polypropylene (PP, F401, Yangzi Petrochemical), maleic anhydride (MAH, chemically pure, Tianjin Damao Chemical Reagent Co., Ltd.), and dicumyl peroxide (DCP, commercially available) were added to a twin-screw extruder (STS35, Nanjing Koperon) according to the formula ratio for melt extrusion and grafting, resulting in PP-g-MAH (the grafting rate of maleic anhydride-grafted polypropylene is also shown in Table 1). Then, the melt-grafted PP-g-MAH was granulated using an underwater pelletizer.

[0085] 2) PP-g-MAH granules and EPDM (3092EPM, Mitsui Chemicals) were subjected to a Diels-Alder reaction in a twin-screw extruder under the catalysis of stannous chloride dihydrate (SnCl2·2H2O, commercially available) to generate PP-MAH-EPDM products, which were then extruded and granulated to obtain PP-MAH-EPDM compatibilizers A1-A5. The reaction temperature was 160℃, the reaction time was 5 min, and the twin-screw speed was 60 rpm.

[0086] Table 1

[0087]

[0088] Examples 1-12 and Comparative Examples 1-2

[0089] Examples 1-12 prepared EPDM / PP thermoplastic elastomers according to the following preparation method and the amounts shown in Table 2, and comparative examples 1-2 were also provided. Examples 1, 6, 11, and 12 used PP-MAH-EPDM compatibilizer A1; Examples 2 and 7 used PP-MAH-EPDM compatibilizer A2; Examples 3 and 8 used PP-MAH-EPDM compatibilizer A3; Examples 4 and 9 used PP-MAH-EPDM compatibilizer A4; and Examples 5 and 10 used PP-MAH-EPDM compatibilizer A5. The preparation method was as follows:

[0090] 1) EPDM, PP, compatibilizer PP-MAH-EPDM, environmentally friendly paraffin oil (Yongzhen Oil Products), inorganic filler (white carbon black, commercially available) and antioxidant (215, Yantai Xinxiu Chemical) are added to a twin-screw extruder in a certain proportion to extrude and obtain rubber-plastic blend masterbatch. The twin-screw extruder temperature is 180℃, the speed is 200rpm, and the residence time is 2min.

[0091] (4) The rubber and plastic masterbatch and vulcanizing agent (BIBP, Arkema) were added to a twin-screw extruder (STS35, Nanjing Koperon) in proportion for dynamic vulcanization, followed by extrusion granulation to obtain EPDM / PP TPV masterbatch. The dynamic vulcanization process conditions were: twin-screw extruder ￠=35mm L / D=56; dynamic vulcanization temperature 200℃; dynamic vulcanization time 2.5min; rotation speed 300rpm.

[0092] Table 2

[0093]

[0094] Test case

[0095] The following mechanical properties were determined using dynamically vulcanized EPDM / PP thermoplastic elastomer particles from Examples 1-12 and Comparative Examples 1-2, and the results are shown in Table 3.

[0096] (1) Elongation at break

[0097] According to ASTM D412 testing, the tensile rate is 500 mm / min.

[0098] (2) Compression permanent deformation

[0099] According to ASTM D395B testing, the test conditions were 70℃ × 22h, and the limiter height was 9.4mm.

[0100] Table 3

[0101]

[0102] As shown in Tables 1-3, the embodiments of the present invention improve the interfacial compatibility of high viscosity ratio EPDM / PP by using PP-MAH-EPDM compatibilizer. The elongation at break of the prepared EPDM / PP TPV is greatly improved, and the compression set is also greatly improved, thereby greatly expanding the application range of EPDM / PP TPV materials, which can be widely used in the automotive, home appliance, wire and cable, construction and other industries.

[0103] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A compatibilizer characterized by, The compatibilizer contains a co-graft of maleic anhydride with polypropylene and EPDM rubber.

2. The compatibilizer of claim 1, wherein, The compatibilizer is a co-grafted compound of maleic anhydride with polypropylene and ethylene propylene diene monomer (EPDM) rubber.

3. The compatibilizer according to claim 1 or 2, wherein The maleic anhydride-polypropylene and EPDM co-grafted compound is obtained by carrying out a Diels-Alder reaction of maleic anhydride-grafted polypropylene and EPDM in the presence of Lewis acid.

4. The compatibilizer of claim 3, wherein, The Lewis acid is one or more of stannous chloride, zinc chloride, and aluminum trichloride.

5. The compatibilizer of claim 3, wherein, The amount of Lewis acid used is 0.3-0.8 parts by weight per 100 parts by weight of EPDM.

6. The compatibilizer of claim 3, wherein, Based on 100 parts by weight of EPDM, the amount of maleic anhydride-grafted polypropylene used is 0.5-1 parts by weight.

7. The compatibilizer of claim 3, wherein, The conditions for the Diels-Alder reaction include: a reaction temperature of 150-160℃ and a reaction time of 3-5 min.

8. The compatibilizer of claim 3, wherein, The grafting rate of the maleic anhydride-grafted polypropylene is 0.6-1%.

9. An EPDM / PP thermoplastic elastomer composition, characterized in that, The composition contains EPDM, PP, a compatibilizer, optional solvent oil, optional inorganic filler, vulcanizing agent, and antioxidant, wherein the compatibilizer is the compatibilizer according to any one of claims 1-8.

10. The composition according to claim 9, wherein, Based on 100 parts by weight of the composition, the composition contains 20-60 parts by weight of EPDM, 10-50 parts by weight of PP, 0.9-3 parts by weight of compatibilizer, 0-40 parts by weight of solvent oil, 0-15 parts by weight of inorganic filler, 0.5-3 parts by weight of vulcanizing agent, and 0.2-0.6 parts by weight of antioxidant.

11. The composition according to claim 10, wherein, The composition contains 30-50 parts by weight of EPDM, 10-30 parts by weight of PP, 1-3 parts by weight of compatibilizer, 10-38 parts by weight of solvent oil, 1-12 parts by weight of inorganic filler, 0.5-2.5 parts by weight of vulcanizing agent, and 0.2-0.5 parts by weight of antioxidant.

12. The composition according to claim 11, wherein, The composition contains 35-40 parts by weight of EPDM, 10-20 parts by weight of PP, 1-2 parts by weight of compatibilizer, 20-35 parts by weight of solvent oil, 3-10 parts by weight of inorganic filler, 0.5-2 parts by weight of vulcanizing agent, and 0.2-0.4 parts by weight of antioxidant.

13. The composition according to claim 12, wherein, The composition contains 38-40 parts by weight of EPDM, 10-15 parts by weight of PP, 1.2-1.6 parts by weight of compatibilizer, 30-35 parts by weight of solvent oil, 5-10 parts by weight of inorganic filler, 0.7-1 parts by weight of vulcanizing agent, and 0.3-0.4 parts by weight of antioxidant.

14. The composition according to claim 9, wherein, Based on the total weight of the EPDM, the content of ethylene structural units in the EPDM is 40-70% by weight and the content of the third monomer is 4-10% by weight.

15. The composition according to claim 14, wherein, The third monomer is one or more of 1,4-hexadiene, dicyclopentadiene (DCPD), and 5-ethylidene-2-norbornene.

16. The composition according to claim 14, wherein, The weight-average molecular weight of the EPDM is 100,000 to 400,000.

17. The composition according to any one of claims 9-16, wherein, The PP is homopolymer polypropylene and / or random copolymer polypropylene.

18. The composition according to claim 17, wherein, The melt flow index of the PP at a temperature of 230℃ and a load of 2.16kg is 1-20g / 10min.

19. The composition according to any one of claims 9-16, wherein, The solvent oil is one or more of environmentally friendly paraffin oil, naphthenic oil, and environmentally friendly aromatic oil.

20. The composition according to any one of claims 9-16, wherein, The inorganic filler is one or more of silica, calcium carbonate, and talc.

21. The composition according to claim 20, wherein, The inorganic filler is silica.

22. The composition according to any one of claims 9-16, wherein, The vulcanizing agent is a peroxide vulcanizing agent.

23. The composition according to claim 22, wherein, The vulcanizing agent is one or more of benzoyl peroxide, 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane and tert-butyl peroxyisopropyl carbonate.

24. The composition according to claim 23, wherein, The vulcanizing agent is tert-butyl peroxide.

25. The composition according to any one of claims 9-16, wherein, The antioxidant is one or more of amine antioxidants, quinoline antioxidants, and benzimidazole antioxidants.

26. The composition according to any one of claims 9-16, wherein, The composition also contains other components such as a release agent and / or an anti-ultraviolet agent.

27. The composition according to claim 26, wherein, Based on 100 parts by weight of the composition, the content of the other components is 0.3-0.4 parts by weight.

28. An EPDM / PP thermoplastic elastomer, formed from the EPDM / PP thermoplastic elastomer composition according to any one of claims 9-27.

29. A method for preparing an EPDM / PP thermoplastic elastomer, characterized in that, This method uses the EPDM / PP thermoplastic elastomer composition according to any one of claims 9-27, and includes the following steps: 1) The EPDM, PP, compatibilizer, optional solvent oil, optional inorganic filler and antioxidant are extruded and granulated to obtain rubber-plastic blend masterbatch; 2) Dynamically vulcanize the rubber-plastic blend masterbatch obtained in step 1) with the vulcanizing agent.

30. The method according to claim 29, wherein, The dynamic vulcanization includes feeding the rubber-plastic blend masterbatch and the vulcanizing agent into a twin-screw extruder for dynamic vulcanization, followed by extrusion granulation.

31. The method according to claim 30, wherein, The conditions for dynamic vulcanization include: a temperature of 190-200℃, a vulcanization time of 2-2.5 min, and a rotation speed of 200-300 rpm.

32. An EPDM / PP thermoplastic elastomer, which is prepared by the preparation method of EPDM / PP thermoplastic elastomer according to any one of claims 29-31.

33. The use of the thermoplastic elastomer of claim 28 or 32 in the manufacture of wires and cables, building materials, automotive seals and interior trim or household appliances.

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