A polypropylene composition and its preparation method and application

Abstract

The present invention provides a polypropylene composition and its preparation method and application, belonging to the field of polymer material technology. The polypropylene composition of the present invention includes the following components in parts by weight: 33-72 parts of polypropylene, 8-32 parts of silicon-based thermoplastic elastomer, 5-15 parts of α-polyolefin, 5-15 parts of porous graphene, 5-25 parts of silicate filler, and 0.1-1 parts of auxiliary agent; wherein α-polyolefin is a copolymer of ethylene, propylene and 1-butene. The present invention adds silicon-based thermoplastic elastomer, α-polyolefin and porous graphene to the polypropylene composition, effectively improving the low-temperature toughness of the polypropylene composition, and reducing the volatile odor of the polypropylene composition.

Description

Technical Field

[0001] The present invention relates to the technical field of polymer materials, and in particular to a polypropylene composition, a preparation method and an application thereof. Background Art

[0002] Polypropylene, a plastic known for its ease of processing, excellent heat resistance, stability, and strength, is increasingly used in automotive interiors. However, as its use in automotive interiors increases, the odor emitted by polypropylene is increasingly impacting interior air quality. This odor directly impacts vehicle quality, human health, and the ecological environment. To ensure vehicle safety, the "Guidelines for Passenger Car Interior Air Quality Assessment" has become a mandatory standard, imposing strict requirements on interior air quality. Given the large volume and variety of polypropylene used in automotive interiors, the development of low-odor polypropylene suitable for automotive interiors is particularly important.

[0003] To reduce the odor of polypropylene, the main approach currently employed is to add porous materials with adsorption properties to polypropylene. These materials include activated carbon, silica gel, metal oxides, attapulgite, and molecular sieves. When these adsorption systems are distributed in a specific pattern within the resin matrix, they are capable of adsorbing odors or volatile small molecules produced by the resin. However, porous materials are only limited in their ability to adsorb the volatile components of volatile additives. Furthermore, excessive use of porous adsorbents, resulting in a high oil absorption value, can adsorb lubricating additives, thereby reducing lubrication and slip performance and leading to decreased mechanical properties of the polypropylene material.

[0004] Therefore, how to reduce the volatile odor of polypropylene while ensuring the performance of polypropylene materials is an urgent problem that needs to be solved. Summary of the Invention

[0005] The purpose of the present invention is to overcome the deficiencies of the prior art and provide a polypropylene composition and a preparation method and application thereof.

[0006] To achieve the above-mentioned objectives, the technical solution adopted by the present invention is as follows: in the first aspect, a polypropylene composition is provided, comprising the following components in parts by weight: 33-72 parts of polypropylene, 8-32 parts of a silicon-based thermoplastic elastomer, 5-15 parts of an α-polyolefin, 5-15 parts of porous graphene, 5-25 parts of a silicate filler, and 0.1-1 part of an additive; wherein the α-polyolefin is a copolymer of ethylene, propylene, and 1-butene.

[0007] In some embodiments, the silicone-based thermoplastic elastomer has a Shore hardness of 40-70A.

[0008] In some embodiments, the α-polyolefin has a tensile strength of 1.5-5 MPa.

[0009] In some embodiments, the silicate filler is at least one of talc, wollastonite, kaolin, and mica.

[0010] In some embodiments, the auxiliary agent is at least one of a lubricant, an antioxidant, and a light stabilizer.

[0011] In some embodiments, the lubricant is at least one of a low molecular weight lipid lubricant, a metal soap lubricant, a stearic acid complex ester lubricant, and an amide lubricant;

[0012] In some embodiments, the antioxidant is at least one of a phenolic antioxidant, a phosphite antioxidant, and a divalent sulfur antioxidant;

[0013] In some embodiments, the light stabilizer is a hindered amine light stabilizer.

[0014] In some embodiments, the polypropylene has a melt mass flow rate of 1 to 100 g / 10 min at 230° C. and a load of 2.16 kg.

[0015] In a second aspect, a method for preparing the polypropylene composition is provided, comprising the following steps:

[0016] After the components are mixed uniformly according to proportion, the obtained premix is ​​added into a screw extruder, melt-extruded and granulated to obtain a polypropylene composition.

[0017] In some embodiments, the temperature of the melt extrusion granulation is 200-220°C.

[0018] In a third aspect, a use of the polypropylene composition in preparing automotive interior trim parts is provided.

[0019] In a fourth aspect, an automobile interior is provided, wherein the automobile interior comprises the polypropylene composition.

[0020] Compared with the existing technology, the present invention has the following beneficial effects: the present invention adds a silicone-based thermoplastic elastomer, α-polyolefin, and porous graphene to a polypropylene composition, effectively improving the low-temperature toughness of the polypropylene composition and reducing the volatile odor of the polypropylene composition. The silicone-based thermoplastic elastomer is formed by uniformly dispersing vulcanized silicone rubber particles in a thermoplastic resin to form a unique sea-island structure, with the thermoplastic resin serving as the continuous phase and the silicone rubber serving as the dispersed phase. The porous structure formed by the silicone rubber particles can adsorb volatile organic compounds (VOCs) while simultaneously improving the low-temperature toughness of the polypropylene composition. α-Polyolefin is formed by polymerizing three monomers: ethylene, propylene, and 1-butene. α-Polyolefin can further enhance the compatibility and dispersion effect between the silicone-based thermoplastic elastomer and polypropylene, improving the low-temperature toughness of the polypropylene composition. The microporous structure of the porous graphene can further adsorb volatile organic compounds. DETAILED DESCRIPTION

[0021] To facilitate understanding of the present invention, the present invention will be described more fully below. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present invention more thorough and comprehensive.

[0022] As used herein:

[0023] "Prepared from" is synonymous with "comprising." As used herein, the terms "comprising," "including," "having," "containing," or any other variations thereof, are intended to cover a non-exclusive inclusion. For example, a composition, process, method, article, or apparatus that comprises the listed elements is not necessarily limited to only those elements but may include other elements not expressly listed or inherent to such composition, process, method, article, or apparatus.

[0024] The conjunction "consisting of" excludes any unspecified element, step, or component. If used in a claim, this phrase renders the claim closed, excluding materials other than those described, except for conventional impurities associated therewith. When the phrase "consisting of" appears in a clause of the body of a claim, rather than immediately following the subject matter, it limits only the elements described in that clause; other elements are not excluded from the claim as a whole.

[0025] When amount, concentration or other value or parameter are represented with range, preferred range or the range that a series of upper preferred value and lower preferred value limit are expressed, this should be understood as specifically disclosing all ranges formed by any pairing of any range upper limit or preferred value and any range lower limit or preferred value, and no matter whether this scope is disclosed separately.For example, when disclosing scope " 1-5 ", described scope should be interpreted as including scope " 1-4 ", " 1-3 ", " 1-2 ", " 1-2 and 4-5 ", " 1-3 and 5 " etc.When numerical range is described in this article, unless otherwise stated, otherwise this scope is intended to include its end value and all integers and fractions within this range.

[0026] In these examples, parts and percentages are by mass unless otherwise indicated.

[0027] "Parts by mass" refers to the basic unit of measurement used to express the mass ratio of multiple components. One part can represent any unit of mass, such as 1g or 2.689g. If we say that the mass of component A is a parts and the mass of component B is b parts, this means the ratio of the mass of component A to the mass of component B is a:b. Alternatively, we could say that the mass of component A is aK and the mass of component B is bK (K is an arbitrary number representing a multiplication factor). It's important to note that, unlike percentage by mass, the sum of the mass of all components is not limited to 100 parts.

[0028] "And / or" is used to indicate that one or both of the stated situations may occur, for example, A and / or B includes (A and B) and (A or B).

[0029] In order to solve the problems of low odor and poor low temperature toughness of polypropylene materials in the prior art.

[0030] In a first aspect, the present invention provides a polypropylene composition comprising the following components in parts by weight: 33-72 parts of polypropylene, 8-32 parts of a silicon-based thermoplastic elastomer, 5-15 parts of an α-polyolefin, 5-15 parts of porous graphene, 5-25 parts of a silicate filler, and 0.1-1 part of an additive; wherein the α-polyolefin is a copolymer of ethylene, propylene, and 1-butene.

[0031] For example, in different embodiments, the weight proportion of the polypropylene may be, but is not limited to, 35 parts, 40 parts, 45 parts, 50 parts, 55 parts, 60 parts, 65 parts, or 70 parts;

[0032] For example, in different embodiments, the weight proportion of the silicone-based thermoplastic elastomer may be, but is not limited to, 10 parts, 12 parts, 15 parts, 17 parts, 20 parts, 23 parts, 25 parts, 28 parts, or 30 parts;

[0033] For example, in different embodiments, the weight proportion of the α-polyolefin may be, but is not limited to, 5 parts, 6 parts, 7 parts, 8 parts, 9 parts, 10 parts, 11 parts, 12 parts, 13 parts, 14 parts, or 15 parts;

[0034] For example, in different embodiments, the weight of the porous graphene can be, but is not limited to, 5 parts, 6 parts, 8 parts, 10 parts, 12 parts, 14 parts, or 15 parts;

[0035] For example, in different embodiments, the weight of the silicate filler may be, but is not limited to, 5 parts, 7 parts, 10 parts, 13 parts, 15 parts, 17 parts, 19 parts, 21 parts, 23 parts, or 25 parts;

[0036] For example, in different embodiments, the weight portion of the auxiliary agent may be, but is not limited to, 0.1 part, 0.2 part, 0.4 part, 0.6 part, 0.8 part, or 1 part.

[0037] Specifically, in the polypropylene composition of the present invention, the mass percentage of polypropylene is not less than 35%.

[0038] Specifically, the polypropylene includes at least one of homopolymer polypropylene, random copolymer polypropylene, and block copolymer polypropylene.

[0039] The present invention incorporates a silicone-based thermoplastic elastomer, α-polyolefin, and porous graphene into a polypropylene composition, effectively improving the low-temperature toughness of the polypropylene composition and reducing its volatile odor. The silicone-based thermoplastic elastomer is a vulcanized silicone rubber particle with an average particle size of 2-3 μm uniformly dispersed in a thermoplastic resin, forming a unique sea-island structure. The thermoplastic resin serves as the continuous phase, and the silicone rubber serves as the dispersed phase. The porous structure formed by the silicone rubber particles can adsorb volatile organic compounds (TVOCs) while simultaneously improving the low-temperature toughness of the polypropylene composition. The α-polyolefin is a polymerized monomer composed of ethylene, propylene, and 1-butene. The α-polyolefin further enhances the compatibility and dispersion between the silicone-based thermoplastic elastomer and polypropylene, improving the low-temperature toughness of the polypropylene composition. The microporous structure of the porous graphene further adsorbs volatile organic compounds.

[0040] The thermoplastic resin matrix of the silicon-based thermoplastic elastomer in the present invention is one of polyolefin, polyurethane and nylon.

[0041] In some embodiments, the Shore hardness of the silicone-based thermoplastic elastomer is 40-70A, for example, but not limited to 45A, 47 A, 50 A, 53 A, 55A, 58 A, 60 A, 62 A, 65 A, 70A, and the test method is ISO 48-4:2018.

[0042] Silicone-based thermoplastic elastomer with a hardness of 40-65A can further improve the rigidity and low-temperature toughness of the polypropylene composition.

[0043] In some embodiments, the α-polyolefin is an amorphous α-polyolefin.

[0044] In some embodiments, the tensile strength of the α-polyolefin is 1.5-5 MPa, for example, but not limited to 1.5 MPa, 1.8 MPa, 2.0 MPa, 2.5 MPa, 3 MPa, 3.5 MPa, 4 MPa, 4.5 MPa, 5 MPa, and the test method is ISO527-3:2018.

[0045] The α-polyolefin having a tensile strength of 1.5-5 MPa can further improve the low-temperature toughness of the polypropylene composition.

[0046] In order to further improve the rigidity and low-temperature toughness of the polypropylene composition, the present invention preferably uses silane-modified α-polyolefin, and more preferably uses siloxane-grafted α-polyolefin.

[0047] In some embodiments, the silicate filler is at least one of talc, wollastonite, kaolin, and mica.

[0048] The above-mentioned silicate fillers can enhance the dispersion of silicon-based thermoplastic elastomers during the extrusion process, thereby better absorbing the chain breakage of alkane molecules generated during the extrusion and injection molding processes, so that the polypropylene composition can achieve a balance of rigidity and toughness while reducing volatile odor.

[0049] Specifically, the average particle size of the silicate filler is 1-50 μm, and the testing method is HS / T 49-2016.

[0050] In some embodiments, the auxiliary agent is at least one of a lubricant, an antioxidant, and a light stabilizer.

[0051] In some embodiments, the lubricant is at least one of a low molecular lipid lubricant, a metal soap lubricant, a stearic acid complex ester lubricant, and an amide lubricant; wherein the low molecular lipid lubricant can be selected from at least one of solid paraffin, liquid paraffin, and low molecular polyolefin wax; the metal soap lubricant can be selected from at least one of calcium stearate, magnesium stearate, zinc stearate, and barium stearate; the stearic acid complex ester lubricant can be selected from at least one of monoglyceride, ethylene glycol stearate, glyceryl stearate, and pentaerythritol stearate; the amide lubricant can be selected from at least one of oleamide, erucamide, methylene bisstearamide, and N,N-ethylene bisstearamide.

[0052] In some embodiments, the antioxidant is at least one of a phenolic antioxidant, a phosphite antioxidant, and a divalent sulfur antioxidant; the phenolic antioxidant may be selected from at least one of antioxidant 264, antioxidant 1010, antioxidant 1076, antioxidant SP, antioxidant 2246, antioxidant CA, antioxidant 330, Irganox 1890, and antioxidant 3114; the phosphite antioxidant may be selected from at least one of antioxidant TNP, antioxidant ODP, antioxidant 168, Irganox 1093, and Irganox 1222; the divalent sulfur antioxidant may be selected from at least one of dilauryl thiodipropionate (DLTP) and distearyl thiodipropionate (DSTP).

[0053] In some embodiments, the light stabilizer is a hindered amine light stabilizer, and the hindered amine light stabilizer can specifically be at least one of UV-3808, LA-402XP, and LA-402AF.

[0054] In some embodiments, the polypropylene has a melt mass flow rate at 230° C. and a load of 2.16 kg of 1-100 g / 10 min, for example, but not limited to, 1 g / 10 min, 10 g / 10 min, 20 g / 10 min, 30 g / 10 min, 50 g / 10 min, 70 g / 10 min, 80 g / 10 min, 90 g / 10 min, and 100 g / 10 min, and the test method is ISO 1133-1:2022.

[0055] In a second aspect, a method for preparing the polypropylene composition is provided, comprising the following steps:

[0056] After the components are mixed uniformly according to proportion, the obtained premix is ​​added into a screw extruder, melt-extruded and granulated to obtain a polypropylene composition.

[0057] In some embodiments, the temperature of the melt extrusion granulation is 200-220°C.

[0058] In some embodiments, the screw extruder has a screw speed of 350-450 rpm.

[0059] In a third aspect, the invention provides an application of the polypropylene composition in the preparation of automotive interior parts, such as dashboards, door panels, pillars and other interior parts.

[0060] The raw materials used in the examples and comparative examples are described below, but are not limited to these materials:

[0061] Polypropylene A: melt mass flow rate of 60 g / 10 min at 230°C and 2.16 kg load, PPM60RHC, Zhenhai Refining and Chemical;

[0062] Polypropylene B: melt mass flow rate of 100 g / 10 min at 230 °C and 2.16 kg load, PPBX3920, Sino-Korean Petrochemical;

[0063] Polypropylene C: melt mass flow rate of 1 g / 10 min at 230°C and 2.16 kg load, PP 3010, Formosa Plastics Corporation;

[0064] Silicone-based thermoplastic elastomer A: Silicone rubber particles dispersed in a TPU (polyurethane) matrix, Shore hardness 45A, Si-TPV 3100-45A, Chengdu Silike;

[0065] Silicone-based thermoplastic elastomer B: Silicone rubber particles dispersed in a TPU (polyurethane) matrix, Shore hardness 53A, Si-TPV 3100-55A, Chengdu Silike;

[0066] Silicone-based thermoplastic elastomer C: Silicone rubber particles dispersed in a TPU (polyurethane) matrix, Shore hardness 60A, Si-TPV 3100-60A, Chengdu Silike;

[0067] Silicone-based thermoplastic elastomer D: Silicone rubber particles dispersed in a TPU (polyurethane) matrix, Shore hardness 63A, Si-TPV 3100-65A, Chengdu Silike;

[0068] Silicone-based thermoplastic elastomer E: Silicone rubber particles dispersed in a TPO (polyolefin) matrix, Shore hardness 70A, Si-TPV2150-70A, Chengdu Silike;

[0069] α-Polyolefin A: copolymer of ethylene, propylene, and 1-butene, with a tensile strength of 1.5 MPa, VESTOPLAST 751, Evonik Technologies;

[0070] α-Polyolefin B: copolymer of ethylene, propylene, and 1-butene, with a tensile strength of 2.0 MPa, VESTOPLAST 891, Evonik Technologies;

[0071] α-Polyolefin C: copolymer of ethylene, propylene, and 1-butene, with a tensile strength of 2.5 MPa, VESTOPLAST 888, Evonik Technologies;

[0072] α-Polyolefin D: copolymer of ethylene, propylene, and 1-butene, tensile strength 5.0 MPa, VESTOPLAST 750, Evonik Technologies;

[0073] Silane-modified α-polyolefin: Siloxane-modified copolymer of ethylene, propylene, and 1-butene, with a tensile strength of 1.9 MPa, VESTOPLAST 206, Evonik Technologies;

[0074] Ethylene-octene copolymer: POE 8842, Dow Chemical;

[0075] Porous graphene: XF269, Xianfeng Nanotechnology;

[0076] Talc: TYT-777A, Beihai Group;

[0077] Wollastonite: TREMIN 939, HPF, Germany;

[0078] Mica powder: 60-D, Huajing Mica;

[0079] Barium sulfate: commercially available;

[0080] Antioxidant 1010: commercially available;

[0081] Antioxidant 168: Commercially available;

[0082] Light stabilizer: UV-3808PP5, cyanoteracem.

[0083] Examples and Comparative Examples

[0084] The components and weight proportions of the polypropylene compositions of the examples and comparative examples are shown in Tables 1 and 2. The preparation methods of the polypropylene compositions of the examples and comparative examples comprise the following steps:

[0085] After uniformly mixing the components according to Table 1 and Table 2, the resulting mixture was added to a twin-screw extruder for melt extrusion and granulation to obtain a polypropylene composition; wherein the twin-screw extruder has an aspect ratio of 40:1, a screw speed of 400 rpm, and an extrusion temperature of 200-220°C.

[0086] The polypropylene compositions obtained in the examples and comparative examples were subjected to performance tests, and the test methods were as follows:

[0087] (1) Flexural modulus: The polypropylene composition was injection molded into a 80 mm * 10 mm * 4 mm sample and tested according to ISO 178-2010. The test conditions were: 23 ° C, bending speed 2 mm / min;

[0088] (2) Izod notched impact strength: The polypropylene composition was injection molded into 80 mm * 10 mm * 4 mm specimens and tested according to ISO 180-2019. The test conditions were: A-notch, -30 °C, pendulum energy 4 J.

[0089] (3) TVOC: The polypropylene compositions of the examples and comparative examples were injection molded into 4 kg specimens at 230° C., and the TVOC (C6-C16) in the specimens was tested using a 2000 L sample bag according to the standard CVTC54072-2015.

[0090] The test results are shown in Tables 1 and 2.

[0091] Table 1

[0092]

[0093] Table 2

[0094]

[0095] From the experimental data in Table 1 and Table 2, it can be seen that the flexural modulus of the polypropylene composition of the present invention is ≥1700 MPa at 23°C and the notched Izod impact strength at -30°C is ≥6 kJ / m 2 , TVOC≤3000μg / m 3 , indicating that the polypropylene composition of the present invention has better low-temperature toughness and lower odor.

[0096] Comparative Examples 3-7 show that the polypropylene composition prepared from a silicone-based thermoplastic elastomer with a Shore hardness of 40-65A has a flexural modulus of ≥1750 MPa at 23°C and an Izod notched impact strength of ≥6 kJ / m at -30°C. 2 , TVOC≤2600μg / m 3 , indicating that when the Shore hardness of the silicone-based thermoplastic elastomer is 40-65A, the polypropylene composition has better low-temperature toughness and lower odor.

[0097] Comparison of Examples 4 and 8-10 shows that the polypropylene composition prepared from α-polyolefin with a tensile strength of 1.5-5 has a flexural modulus of ≥1700 MPa at 23°C and an Izod notched impact strength of ≥6.3 kJ / m at -30°C. 2 , TVOC≤2700μg / m 3 , indicating that when the tensile strength of α-polyolefin is 1.5-5, the polypropylene composition has better low-temperature toughness and lower odor.

[0098] Comparison of Example 4 and Example 11 shows that the polypropylene composition prepared by silane-modified α-polyolefin has a flexural modulus of ≥1800 MPa at 23°C and an Izod notched impact strength of ≥7 kJ / m at -30°C. 2 , TVOC≤2000μg / m 3 , indicating that when α-polyolefin is modified by silane, the polypropylene composition has better low-temperature toughness and lower odor.

[0099] Comparison of Example 4, Examples 12-13 and Comparative Example 6 shows that the filler is a silicate filler, and the obtained polypropylene composition has a 23°C flexural modulus ≥ 1700 MPa and a -30°C Izod notched impact strength ≥ 6 kJ / m 2 , TVOC≤3000μg / m 3 , indicating that when silicate filler is selected as filler, the rigidity of the polypropylene composition can be improved and the odor can be lowered.

[0100] Comparison of Example 4 and Comparative Examples 1-5 shows that the lack of at least one of the silicon-based thermoplastic elastomer, α-polyolefin, and porous graphene, or the use of other analogs to replace the silicon-based thermoplastic elastomer or α-polyolefin, the obtained polypropylene composition has a -30°C Izod notched impact strength of ≤5 kJ / m 2 , TVOC≥3500μg / m 3 , indicating that the lack of at least one of silicon-based thermoplastic elastomer, α-polyolefin, and porous graphene, or the use of other analogs to replace silicon-based thermoplastic elastomer or α-polyolefin, cannot make the polypropylene composition have good low-temperature toughness and low odor.

[0101] Finally, it should be noted that the above embodiments are used to illustrate the technical solutions of the present invention rather than to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A polypropylene composition, characterized in that The invention comprises the following components in parts by weight: 33-72 parts of polypropylene, 8-32 parts of silicon-based thermoplastic elastomer, 5-15 parts of α-polyolefin, 5-15 parts of porous graphene, 5-25 parts of silicate filler, and 0.1-1 part of additive; wherein the α-polyolefin is a copolymer of ethylene, propylene and 1-butene; The continuous phase of the silicon-based thermoplastic elastomer is thermoplastic resin, and the dispersed phase is silicone rubber.

2. The polypropylene composition according to claim 1, wherein The Shore hardness of the silicone-based thermoplastic elastomer is 40-70A.

3. The polypropylene composition according to claim 1, wherein The tensile strength of the α-polyolefin is 1.5-5 MPa.

4. The polypropylene composition according to claim 1, wherein The silicate filler is at least one of talc, wollastonite, kaolin and mica.

5. The polypropylene composition according to claim 1, wherein The auxiliary agent is at least one of a lubricant, an antioxidant, and a light stabilizer.

6. The polypropylene composition according to claim 5, wherein The lubricant is at least one of a low molecular weight lipid lubricant, a metal soap lubricant, a stearic acid complex ester lubricant, and an amide lubricant; And / or, the antioxidant is at least one of a phenolic antioxidant, a phosphite antioxidant, and a divalent sulfur antioxidant; And / or, the light stabilizer is a hindered amine light stabilizer.

7. The polypropylene composition according to claim 1, wherein The polypropylene has a melt mass flow rate of 1-100 g / 10 min at 230° C. and a load of 2.16 kg.

8. A method for preparing the polypropylene composition according to any one of claims 1 to 7, characterized in that: The following steps are involved: After the components are mixed uniformly according to proportion, the obtained premix is ​​added into a screw extruder, melt-extruded and granulated to obtain a polypropylene composition.

9. Use of the polypropylene composition according to any one of claims 1 to 7 in the preparation of automotive interior trim parts.

10. An automobile interior, characterized in that: The automotive interior comprises the polypropylene composition according to any one of claims 1 to 7.

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