Polypropylene composite material with high fluidity and high impact resistance as well as preparation method and application of polypropylene composite material

Abstract

The invention relates to the technical field of polymer modification, and provides a polypropylene composite material with high fluidity and high impact resistance as well as a preparation method and application thereof. According to the polypropylene composite material, a degradation method is adopted, and the polypropylene composite material is prepared from the following raw materials in percentage by weight: 98.7 to 99.85 percent of a polypropylene resin base material, 0.05 to 0.3 percent of an anti-impact flow modification aid DeltaMax 5000a and 0.1 to 1 percent of a free radical type initiator. The polypropylene composite material with high flowability and high impact resistance, provided by the invention, is prepared by modifying the polypropylene resin base material by using the flexibilizer DeltaMax 5000a and the degradation agent in a matched manner, so that the polypropylene composite material has relatively good flowability and impact resistance at the same time; the high requirements of plastic parts of automobiles, household appliances and the like on anti-falling performance and processing fluidity can be met; the preparation method is simple and easy to operate, low in cost and easy to popularize and use on a large scale.

Description

Technical Field

[0001] The invention relates to the technical field of polymer modification, and more specifically to a polypropylene composite material with high fluidity and high impact resistance, and a preparation method and application thereof. Background Art

[0002] Polypropylene (PP) is a general-purpose plastic with excellent comprehensive properties. High-strength and high-toughness PP composite materials can be obtained through blending and compounding. Such composite materials are widely used in automobiles, home appliances, packaging and other fields. In the automotive field, high-impact PP composite materials have become the mainstream of automobile bumper materials. Toughening modification is one of the main research directions in PP blending modification. There have been many research reports in this area at home and abroad. The developed high-impact PP has been widely used as a special material for automobile bumpers. However, while improving the toughness of PP, how to improve its fluidity and rigidity to meet the requirements of large-scale and thin products is still the focus of current research.

[0003] High melt fluidity (MFR ≥ 90g / 10min) ensures the easy processing of polypropylene. During the product processing and production process, the processing temperature, injection pressure, clamping force, etc. can be reduced, thereby reducing energy consumption, shortening the product molding cycle, and increasing product output. High rigidity can reduce the thickness of the product while maintaining the same mechanical strength, and achieve thin-walled large products, which is of great significance to automobile weight reduction. Higher impact resistance means that less elastomer can be added, avoiding the cost increase and melt flow rate reduction caused by adding more elastomers. High-impact polypropylene resin with a high melt flow rate is widely used in the injection molding field because it has higher processing and molding efficiency than ordinary impact copolymers, and its market profit is also significantly higher than that of ordinary impact copolymers.

[0004] Most of the high-flow impact-resistant polypropylene currently on the market is produced by the hydrogen adjustment method. It has the characteristics of good flowability and high impact resistance, and is very popular among users. However, due to technical reasons of the equipment, some manufacturers are unable to use the hydrogen adjustment method to produce high-flow polypropylene, and can only use the organic peroxide initiator degradation method to produce such products. However, although the flowability of the impact-resistant polypropylene produced by the degradation method can meet the processing requirements of users, the impact performance is greatly reduced and cannot meet the use needs of customers. This has become a major problem that troubles raw material manufacturers. Summary of the invention

[0005] The purpose of the present invention is to provide a polypropylene composite material with high fluidity and high impact resistance and a preparation method thereof, so as to solve the technical problem that the high fluidity and impact resistance polypropylene produced by the degradation method in the prior art has poor impact strength.

[0006] To achieve the above object, the technical solution adopted by the present invention is:

[0007] In a first aspect, the present invention provides a polypropylene composite material with high fluidity and high impact resistance, which is prepared by a degradation method using raw materials including the following components in percentage by mass:

[0008] Polypropylene resin base material 98.7~99.85%;

[0009] Toughening agent DeltaMax 5000a 0.05~0.3%;

[0010] Free radical initiator 0.1%~1%.

[0011] DeltaMax 5000a is a performance modifier for polypropylene launched by Milliken & Company. It is mainly used to optimize the impact resistance of polypropylene resin without significantly weakening its rigidity. It can be used to improve the low-temperature toughness of hydrogen-adjusted impact-resistant polypropylene.

[0012] Using free radical initiators as degradation agents to modify polypropylene resin base materials can effectively improve the fluidity of polypropylene resin base materials, but at the same time it also has an adverse effect on the impact resistance of polypropylene resin base materials. In order to avoid a significant decrease in the impact resistance of polypropylene composite materials, it is necessary to add toughening agents for toughening modification. However, since free radical initiators will also affect the toughening agents, a larger amount of toughening agents will have a better toughening effect. Increasing the amount of toughening agents added will not only lead to a significant increase in product costs, but will also have an adverse effect on the fluidity of polypropylene composite materials. Therefore, it is difficult to use the degradation method to prepare polypropylene composite materials with ideal impact resistance and fluidity.

[0013] The inventor of the present application accidentally discovered during the research process that the use of DeltaMax5000a as a toughening agent is significantly less adversely affected by free radical initiators than other toughening agents, and a smaller addition amount can significantly improve the impact resistance of polypropylene composite materials. By applying it in the degradation method, a polypropylene composite material with both high fluidity and high impact resistance can be prepared.

[0014] In the present invention, the mass percentage of the toughening agent DeltaMax 5000a in the raw material can be 0.05%, 0.06%, 0.08%, 0.1%, 0.13%, 0.15%, 0.18%, 0.2%, 0.22%, 0.25%, 0.27%, 0.28%, 0.3%, etc.

[0015] According to some embodiments of the present invention, the toughening agent DeltaMax 5000a accounts for 0.08-0.27% by mass in the raw material.

[0016] In the present invention, the mass percentage of the free radical initiator in the raw material can be 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, etc.

[0017] According to some embodiments of the present invention, the free radical initiator accounts for 0.3-0.8% by mass in the raw material.

[0018] According to some embodiments of the present invention, the free radical initiator is an organic peroxide initiator. Specifically, the free radical initiator used in the present invention can be a common organic peroxide initiator.

[0019] According to some embodiments of the present invention, the organic peroxide initiator is diisopropyl di-tert-butyl peroxide.

[0020] The structure of diisopropylbenzene ditert-butylperoxide is shown below:

[0021]

[0022] In the polypropylene composite material with high fluidity and high impact resistance provided by the present invention, the use of di-tert-butyl diisopropylbenzene peroxide as a degradation agent has the advantages of low addition amount, low cost and low odor.

[0023] The polypropylene resin base material used in the present invention can be selected from various common brands of homopolymer polypropylene resin or block copolymer polypropylene resin.

[0024] According to some embodiments of the present invention, the polypropylene resin base material is block copolymer polypropylene.

[0025] According to some embodiments of the present invention, the comonomer of the block copolymerized polypropylene is ethylene.

[0026] According to some embodiments of the present invention, the mass content of ethylene repeating units is 5 to 25%.

[0027] According to some embodiments of the present invention, the polypropylene resin base material has a melt flow rate of 3.0 to 15.0 g / 10 min at 230° C. and 2.16 kg.

[0028] According to some embodiments of the present invention, the molecular weight distribution index of the polypropylene resin base material is Mw / Mn=4.0-7.0.

[0029] In a second aspect, the present invention provides a method for preparing the polypropylene composite material described in the first aspect, comprising: mixing a polypropylene resin base material, a toughening agent and a free radical initiator component, and then melt-extruding, drawing, cooling and granulating to obtain the polypropylene composite material.

[0030] According to some embodiments of the present invention, the mixing comprises mixing in a high-speed mixer for 1-5 min.

[0031] According to some embodiments of the present invention, the melt extrusion uses a twin-screw extruder.

[0032] According to some embodiments of the present invention, the screw speed of the twin-screw extruder is 100 to 600 r / min.

[0033] According to some embodiments of the present invention, the temperature settings of the twin-screw extruder from feeding to the die are: 190-200°C, 195-205°C, 200-210°C, 205-215°C, 205-215°C, 200-210°C, 195-205°C, 190-200°C, and 185-195°C.

[0034] In a third aspect, the present invention provides the use of the polypropylene composite material described in the first aspect and the polypropylene composite material prepared by the preparation method described in the second aspect in the field of automotive materials and household appliance materials, especially in automotive bumpers.

[0035] The beneficial effects of the present invention are at least:

[0036] (1) The polypropylene composite material with high fluidity and high impact resistance provided by the present invention is prepared by modifying a polypropylene resin base material using a toughening agent DeltaMax 5000a in combination with a degradation agent. It can have both good fluidity and impact resistance, and can meet the high requirements of plastic parts for automobiles, home appliances, etc. for drop resistance and processing fluidity.

[0037] (2) The polypropylene composite material with high fluidity and high impact resistance provided by the present invention is prepared by a degradation method, which is simple and easy to operate, has low cost, and is easy to promote and use on a large scale. DETAILED DESCRIPTION

[0038] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with specific embodiments. It should be understood that the specific embodiments described herein are only used to explain this patent in detail and do not limit the scope of protection of the present invention in any way.

[0039] Unless otherwise defined, the technical terms used in the following examples have the same meanings as those generally understood by those skilled in the art to which the present invention belongs. The reagents used in the following examples, unless otherwise specified, are all conventional biochemical reagents; the raw materials, instruments and equipment used in the following examples, etc., can all be purchased on the market or can be obtained by existing methods; the reagent amounts, unless otherwise specified, are the reagent amounts used in conventional experimental operations; the experimental methods, unless otherwise specified, are all conventional methods.

[0040] In each embodiment and comparative example of the present invention, each performance data is tested according to the following test method:

[0041] (1) Simply supported beam notched impact strength: tested in accordance with the national standard GB / T 1043.1-2008.

[0042] (2) Melt flow rate (MFR): measured in accordance with the national standard GBT 3682-2000 Determination of mass flow rate and volume flow rate of thermoplastic melts.

[0043] In various embodiments and comparative examples of the present invention, the materials used are as follows:

[0044] (1) Polypropylene resin base material: Ethylene block impact copolymer polypropylene EP5010C produced by Sinopec SABIC Petrochemical Company, with a melt flow rate of 10 g / 10 min (230° C., 2.16 kg), a molecular weight distribution index of 5.8, and an ethylene content of 6 wt%.

[0045] (2) Free radical initiator: diisopropyl di-tert-butyl peroxide.

[0046] (3) Toughener DeltaMax 5000a: Milliken & Company.

[0047] (4) Toughening agent POE8105: DOW Company.

[0048] (5) Toughening agent SEBS R-506A: Hunan Boraikang New Materials Co., Ltd.

[0049] The raw materials were weighed according to the components and weight ratios shown in Table 1, and the polypropylene resin base material, toughening agent and free radical initiator were placed in a high-speed mixer for mixing; the uniformly mixed raw materials were added to the twin-screw extruder from the main feeding port, and after melt extrusion, drawing, cooling and granulation, a high-impact and high-flow composite material was prepared through drying, wherein the mixing time, screw speed and extruder temperature settings are shown in Table 2.

[0050] Table 1

[0051]

[0052] Table 2

[0053]

[0054] The impact strength and melt flow rate of the polypropylene materials or polypropylene composite materials of Examples 1-7 and Comparative Examples 1-4 were tested. The results are shown in Table 3.

[0055] Table 3

[0056]

[0057] It can be seen from the above experimental results that the polypropylene composite material provided by the present invention uses DeltaMax 5000a as a toughening agent. Compared with the polypropylene composite material using other toughening agents, not only is the addition amount less, but also the high-flowability polypropylene that is degraded by the initiator has significantly better impact resistance.

[0058] It should be noted that the embodiments described above are only used to explain the present invention and do not constitute any limitation to the present invention. The present invention has been described with reference to typical embodiments, but it should be understood that the words used therein are descriptive and explanatory words, rather than restrictive words. The present invention may be modified as specified within the scope of the claims of the present invention, and the present invention may be revised without departing from the scope and spirit of the present invention. Although the present invention described therein relates to specific methods, materials and embodiments, it does not mean that the present invention is limited to the specific examples disclosed therein, on the contrary, the present invention can be extended to all other methods and applications with the same functions.

Claims

1. A polypropylene composite material with high fluidity and high impact resistance, characterized in that: The raw materials including the following components in mass percentage are prepared by degradation method: Polypropylene resin base material 98.7~99.85%; Toughening agent DeltaMax 5000a 0.05~0.3%; Free radical initiator 0.1%~1%.

2. The polypropylene composite material according to claim 1, characterized in that: The mass percentage of the toughening agent DeltaMax 5000a in the raw material is 0.08-0.27%; And / or, the mass percentage of the free radical initiator in the raw material is 0.3-0.8%.

3. The polypropylene composite material according to claim 1 or 2, characterized in that: The free radical initiator is an organic peroxide initiator; Preferably, the organic peroxide initiator is diisopropyl di-tert-butyl peroxide.

4. The polypropylene composite material according to any one of claims 1 to 3, characterized in that The polypropylene resin base material is block copolymer polypropylene; Preferably, the comonomer of the block copolymer polypropylene is ethylene; More preferably, the mass content of ethylene repeating units is 5 to 25%.

5. The polypropylene composite material according to any one of claims 1 to 4, characterized in that The melt flow rate of the polypropylene resin base material at 230° C. and 2.16 kg is 3.0 to 15.0 g / 10 min.

6. The polypropylene composite material according to any one of claims 1 to 5, characterized in that: The molecular weight distribution index of the polypropylene resin base material is Mw / Mn=4.0-7.

0.

7. The method for preparing the polypropylene composite material according to any one of claims 1 to 6, characterized in that: include: The polypropylene resin base material, toughening agent and free radical initiator components are mixed and then melt-extruded, drawn into strips, cooled and granulated to obtain the polypropylene composite material.

8. The method for preparing the polypropylene composite material according to claim 7, characterized in that: The mixing includes mixing in a high-speed mixer for 1-5 minutes; And / or, the melt extrusion adopts a twin-screw extruder.

9. The method for preparing the polypropylene composite material according to claim 8, characterized in that: The screw speed of the twin-screw extruder is 100-600 r / min; And / or, the temperature settings of the twin-screw extruder from feeding to the die are: 190-200°C, 195-205°C, 200-210°C, 205-215°C, 205-215°C, 200-210°C, 195-205°C, 190-200°C, 185-195°C.

10. Use of the polypropylene composite material according to any one of claims 1 to 6 and the polypropylene composite material prepared by the preparation method according to any one of claims 7 to 9 in the fields of automobile materials and household appliance materials, especially in automobile bumpers.

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