A high-strength and high-toughness polypropylene material for automobile cable ties and preparation method thereof

Abstract

The present invention belongs to the technical field of polypropylene, and specifically relates to a high-strength and high-toughness polypropylene material for automobile cable ties and a preparation method thereof. The material comprises raw materials of the following components: a first component polypropylene, a second component polypropylene, an antioxidant, and a black masterbatch, wherein the first component polypropylene is a modified polypropylene, and the second component polypropylene is a random copolymer polypropylene. The preparation method comprises the following steps: material preparation: weighing the raw materials; premixing: putting the first component polypropylene, the second component polypropylene, the antioxidant, and the black masterbatch into a mixer, mixing to obtain a premix; kneading: adding the premix into a twin-screw extruder, melt-extruded to obtain a molten material; granulation: drawing, cooling, and pelletizing the molten material to obtain a polypropylene material. The present invention can reduce the addition of additives, and the toughness and strength of the material are better.

Description

Technical Field

[0001] The invention belongs to the technical field of polypropylene, and in particular relates to a high-strength and high-toughness polypropylene material for automobile cable ties and a preparation method thereof. Background Art

[0002] The function of automotive cable ties is to fasten the wiring harness and fix it firmly and reliably in the holes, bolts, steel plates and other parts of the body sheet metal to prevent the wiring harness from vibrating, shifting or interfering with other parts and damaging the wiring harness. Automotive cable ties are usually nylon cable ties, which are generally made of polyamide and have the characteristics of high tensile strength, fatigue resistance, oil resistance and high temperature resistance. However, they are easy to become brittle under low temperature dry conditions and have poor chemical corrosion resistance. In addition, they need to be dried before production, which is a cumbersome process.

[0003] Polypropylene (PP) is a general-purpose plastic with low density, low cost and excellent comprehensive performance. It is one of the most promising thermoplastics. However, its practical application is limited due to its poor toughness, especially brittleness at low temperatures.

[0004] At present, nucleating agents are generally used for polypropylene modification. As auxiliary agents, nucleating agents can regulate the crystallization behavior of polymers and accelerate the crystallization rate. In polypropylene products, nucleating agents can be used to improve their optical properties, such as haze and surface gloss; they can also be used to improve their mechanical properties, but they are generally used to improve rigidity, and it is difficult to balance toughness and rigidity.

[0005] For example, referring to the patent publication number CN103333408B, a polypropylene composite material and its preparation method and application are disclosed, in which the polypropylene composite material replaces the nylon material, and the components of the polypropylene composite material include: polypropylene, metallocene polypropylene elastomer, heat stabilizer, and polypropylene special nucleating agent. The nucleating agent in the patent is also mainly used to improve its optical properties.

[0006] In polypropylene products, polypropylene and polyethylene are also blended to modify polypropylene. However, this type of modification method usually requires the use of more components to balance the system, which not only increases the difficulty of the process, but also requires consideration of multiple factors such as interface compatibility. Different polymer melts may also hinder and compete with each other during blending and crystallization, thereby inhibiting the formation of each other's crystal nuclei.

[0007] Therefore, based on the existing technology and the above-mentioned patents, we want to try to minimize the use of additives to modify the polypropylene material, reduce the difficulty of the process, and improve the toughness and strength of the polypropylene material. Summary of the invention

[0008] The first object of the present invention is to provide a high-strength and high-toughness polypropylene material for automobile cable ties and a preparation method thereof, which can reduce the addition of auxiliary agents and has better toughness and strength.

[0009] A high-strength and high-toughness polypropylene material for automobile cable ties, comprising the following raw materials:

[0010] The first component polypropylene, the second component polypropylene, antioxidant, black masterbatch,

[0011] The first component polypropylene is modified polypropylene, and the second component polypropylene is random copolymer polypropylene.

[0012] The above technical solution is adopted. Since polypropylene is easy to age, an antioxidant is added in the present application to improve the shortcomings of polypropylene. In addition, the present application adopts two kinds of polypropylene blends, and the antioxidant and the black masterbatch are used to modify the polypropylene material together to avoid the situation where different types of polymers hinder each other's nucleus formation during the blending crystallization. The present application selects two groups of polypropylenes with better interface compatibility, and does not need to add additional nucleating agents to force the change of crystallization behavior, which reduces the process difficulty. The addition of nucleating agents will also bring the risk of generating pores, which will reduce the performance of the final material.

[0013] Preferably, it is composed of the following ingredients in parts by weight:

[0014] The first component polypropylene is 60-80 parts, the second component polypropylene is 15-40 parts, the antioxidant is 0.1-0.3 parts, and the black masterbatch is 0.5-3 parts.

[0015] Preferably, the antioxidant includes at least one of a phenolic antioxidant, an amine antioxidant, and a phosphite antioxidant.

[0016] Preferably, the black masterbatch is a carbon black masterbatch.

[0017] Preferably, the modified polypropylene is HCPP.

[0018] By adopting the above technical solution, the modified polypropylene is a polypropylene with high crystallinity, high rigidity and high impact.

[0019] The second object of the present invention is to provide a method for preparing the high-strength and high-toughness polypropylene material for automobile cable ties, comprising the following steps:

[0020] S1. Prepare materials: weigh the raw materials;

[0021] S2, premixing: putting the first component polypropylene, the second component polypropylene, the antioxidant, and the black masterbatch into a mixer, mixing to obtain a premix;

[0022] S3, mixing: adding the premix into a twin-screw extruder, and melt-extrude to obtain a molten material;

[0023] S4, granulation: the molten material is stretched, cooled, and pelletized to obtain a polypropylene material.

[0024] Preferably, in step S2, mixing is performed for 8 to 15 minutes; in step S3, the temperature of each zone of the screw is 190° C. to 230° C., and the screw speed is 250 to 600 rpm.

[0025] The beneficial effects of the present invention are:

[0026] First, the present application has fewer additives. Specifically, the present application does not use conventional nucleating agents to modify polypropylene. The present application has fewer raw materials, including a first component polypropylene, a second component polypropylene, an antioxidant, and a black masterbatch. The present application melt-blends HCPP and random copolymer polypropylene. The HCPP has better fluidity, so that the mutual fusion degree is better during blending. The random copolymer polypropylene brings ethylene into the blend, and the ethylene molecules are randomly inserted into the propylene molecules of the blend, so that the final polypropylene material modification effect is better.

[0027] Second, the material of the present application has high strength and toughness and can replace PA66 in some non-high-heat environments.

[0028] Third, when processing the materials of the present application, no pre-treatment of the materials is required, the processing temperature is low, and the energy consumption is low.

[0029] Fourth, the preparation method of the present application has fewer steps, lower process difficulty, and lower professional requirements for operators. DETAILED DESCRIPTION

[0030] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0031] Unless otherwise specified, the equipment and materials used in the examples can be easily obtained from commercial companies, including HCPP: SABIC, CX03-82; random copolymer polypropylene: Yanshan Petrochemical B8101.

[0032] Example 1

[0033] A polypropylene material, the raw material formula is shown in the following Table 1:

[0034] Table 1

[0035] formula Weight parts Components The first component is polypropylene 83.8 HCPP The second component is polypropylene 15 Random Copolymer Polypropylene Antioxidants 0.2 Phenolic antioxidants Black Masterbatch 1 Carbon Black Masterbatch

[0036] Referring to Table 1 above, the preparation of the present application includes the following steps:

[0037] S1. Prepare materials: weigh the raw materials in Table 1;

[0038] S2, premixing: put the first component polypropylene, the second component polypropylene, the antioxidant, and the black masterbatch into a high-speed mixer and mix for 10 minutes to obtain a premix;

[0039] S3, mixing: adding the premix into a twin-screw extruder, and melt extruding, the temperature of each zone of the screw is 190°C to 230°C, and the screw speed is 250 to 600 rpm to obtain a molten material;

[0040] S4. Granulation: At a water temperature of 30-50°C, the molten material is drawn into strips, cooled, and pelletized to obtain a polypropylene material.

[0041] Example 2

[0042] A polypropylene material, the raw material formula is shown in the following Table 2:

[0043] Table 2

[0044] formula Weight parts Components The first component is polypropylene 78.8 HCPP The second component is polypropylene 20 Random Copolymer Polypropylene Antioxidants 0.2 Amine antioxidants Black Masterbatch 1 Carbon Black Masterbatch

[0045] Referring to Table 2 above, the preparation of the present application includes the following steps:

[0046] S1. Prepare materials: weigh the raw materials in Table 2;

[0047] S2, premixing: put the first component polypropylene, the second component polypropylene, the antioxidant, and the black masterbatch into a high-speed mixer and mix for 10 minutes to obtain a premix;

[0048] S3, mixing: adding the premix into a twin-screw extruder, and melt extruding, the temperature of each zone of the screw is 190°C to 230°C, and the screw speed is 250 to 600 rpm to obtain a molten material;

[0049] S4. Granulation: At a water temperature of 30-50°C, the molten material is drawn into strips, cooled, and pelletized to obtain a polypropylene material.

[0050] Example 3

[0051] A polypropylene material, the raw material formula is shown in the following Table 3:

[0052] Table 3

[0053]

[0054]

[0055] Referring to Table 3 above, the preparation of the present application includes the following steps:

[0056] S1. Prepare materials: weigh the raw materials in Table 3;

[0057] S2, premixing: put the first component polypropylene, the second component polypropylene, the antioxidant, and the black masterbatch into a high-speed mixer and mix for 10 minutes to obtain a premix;

[0058] S3, mixing: adding the premix into a twin-screw extruder, and melt extruding, the temperature of each zone of the screw is 190°C to 230°C, and the screw speed is 250 to 600 rpm to obtain a molten material;

[0059] S4. Granulation: At a water temperature of 30-50°C, the molten material is drawn into strips, cooled, and pelletized to obtain a polypropylene material.

[0060] Example 4

[0061] A polypropylene material, the raw material formula is shown in the following Table 4:

[0062] Table 4

[0063] formula Weight parts Components The first component is polypropylene 58.8 HCPP The second component is polypropylene 40 Random Copolymer Polypropylene Antioxidants 0.2 Phosphite antioxidants, amine antioxidants Black Masterbatch 1 Carbon Black Masterbatch

[0064] Referring to Table 4 above, the preparation of the present application includes the following steps:

[0065] S1. Prepare materials: weigh the raw materials in Table 4;

[0066] S2, premixing: put the first component polypropylene, the second component polypropylene, the antioxidant, and the black masterbatch into a high-speed mixer and mix for 10 minutes to obtain a premix;

[0067] S3, mixing: adding the premix into a twin-screw extruder, and melt extruding, the temperature of each zone of the screw is 190°C to 230°C, and the screw speed is 250 to 600 rpm to obtain a molten material;

[0068] S4. Granulation: At a water temperature of 30-50°C, the molten material is drawn into strips, cooled, and pelletized to obtain a polypropylene material.

[0069] Comparative Example 1

[0070] A polypropylene material, the raw material formula is shown in the following Table 5:

[0071]

[0072]

[0073] Referring to Table 5 above, the preparation includes the following steps:

[0074] S1. Prepare materials: weigh the raw materials in Table 5;

[0075] S2, premixing: put the first component polypropylene, homopolymer polypropylene, nucleating agent, antioxidant, and black masterbatch into a high-speed mixer and mix for 8 minutes to obtain a premix;

[0076] S3, mixing: adding the premix into a twin-screw extruder, and melt extruding, the temperature of each zone of the screw is 190°C to 230°C, and the screw speed is 250 to 600 rpm to obtain a molten material;

[0077] S4. Granulation: At a water temperature of 30-50°C, the molten material is drawn into strips, cooled, and pelletized to obtain a polypropylene material.

[0078] Comparative Example 2

[0079] A polypropylene material, the raw material formula is shown in the following Table 6:

[0080] formula Weight (%) Components The first component is polypropylene 78.8 HCPP Nylon 6 15 / First compatibilizer 1 POE-g-MAH Second compatibilizer 4 PP-g-MAH Black Masterbatch 1 Carbon Black Masterbatch Antioxidants 0.2 Phenolic antioxidants

[0081] Referring to Table 6 above, the preparation includes the following steps:

[0082] S1. Prepare materials: weigh the raw materials in Table 6;

[0083] S2, premixing: put the first component polypropylene, nylon 6, the first compatibilizer, the second compatibilizer, the antioxidant, and the black masterbatch into a high-speed mixer and mix for 8 minutes to obtain a premix;

[0084] S3, mixing: adding the premix into a twin-screw extruder, and melt extruding, the temperature of each zone of the screw is 190°C to 230°C, and the screw speed is 250 to 600 rpm to obtain a molten material;

[0085] S4. Granulation: At a water temperature of 30-50°C, the molten material is drawn into strips, cooled, and pelletized to obtain a polypropylene material.

[0086] Comparative Example 3

[0087] A polypropylene material, the raw material formula is shown in the following Table 7:

[0088] Table 7

[0089] formula Weight (%) Components The first component is polypropylene 78.8 HCPP The second component is polypropylene 0 Random Copolymer Polypropylene Homopolymer Polypropylene 20 / High Density Polyethylene 0 HDPE Antioxidants 0.2 Phosphite antioxidants Black Masterbatch 1 Carbon Black Masterbatch

[0090] Referring to Table 7 above, the preparation includes the following steps:

[0091] S1. Prepare materials: weigh the raw materials in Table 7;

[0092] S2, premixing: put the first component polypropylene, homopolymer polypropylene, antioxidant, and black masterbatch into a high-speed mixer and mix for 8 minutes to obtain a premix;

[0093] S3, mixing: adding the premix into a twin-screw extruder, and melt extruding, the temperature of each zone of the screw is 190°C to 230°C, and the screw speed is 250 to 600 rpm to obtain a molten material;

[0094] S4. Granulation: At a water temperature of 30-50°C, the molten material is drawn into strips, cooled, and pelletized to obtain a polypropylene material.

[0095] Comparative Example 4

[0096] A polypropylene material, the formula is shown in the following Table 8:

[0097] Table 8

[0098] formula Weight (%) Components The first component is polypropylene 0 HCPP The second component is polypropylene 0 Random Copolymer Polypropylene Homopolymer Polypropylene 58.8 / High Density Polyethylene 40 HDPE Antioxidants 0.2 Phosphite antioxidants Black Masterbatch 1 Carbon Black Masterbatch

[0099] Referring to Table 8 above, the preparation includes the following steps:

[0100] S1. Prepare materials: weigh the raw materials in Table 8;

[0101] S2, premixing: homopolymer polypropylene, high-density polyethylene, antioxidant, and black masterbatch are put into a high-speed mixer and mixed for 10 minutes to obtain a premix;

[0102] S3, mixing: adding the premix into a twin-screw extruder, and melt extruding, the temperature of each zone of the screw is 190°C to 230°C, and the screw speed is 250 to 600 rpm to obtain a molten material;

[0103] S4. Granulation: At a water temperature of 30-50°C, the molten material is drawn into strips, cooled, and pelletized to obtain a polypropylene material.

[0104] The polypropylene materials of Examples 1-4 and the polypropylene materials of Comparative Examples 1-2 were sampled and then subjected to comparative experiments. The test items and results are shown in Table 7 below:

[0105] Table 7

[0106]

[0107] Referring to the above Table 7, the results are analyzed:

[0108] (1) Melt index: Examples 1 to 4 and Comparative Examples 1 to 4 are all within the index range, and Example 4 has the highest melt index, indicating that the polypropylene material produced according to the raw material formula of Example 4 has the best fluidity.

[0109] (2) Tensile strength. Examples 1 to 4 and Comparative Examples 1 to 4 all meet the index, but Comparative Example 2 is the lowest and Comparative Example 3 is the highest. The difference between Example 1 and Comparative Example 3 of the present application is only 0.1 MPa, indicating that the polypropylene material produced by the raw material formula of Example 1 of the present application has a narrow molecular weight distribution, better tensile strength and better toughness. Compared with Comparative Example 1, although Comparative Example 1 adds a nucleating agent, the tensile strength is reduced. In Comparative Example 2, the present application uses nylon 6 to replace polypropylene and polyethylene, and an additional compatibilizer is required to make nylon 6 compatible with HCPP. From the results, it can be seen that the tensile strength of the composite material is not as high as that of the conventional single material, indicating that the compatibility of the two is general. Even if a compatibilizer is added, a better effect is not obtained. However, the present application does not require too much additives, and still can obtain better toughness, and the toughness is also improved. In addition, in Comparative Example 4, the mixing of high-density polyethylene makes it difficult to balance the system, which easily causes mutual obstruction between the two melts of polypropylene and polyethylene, affecting the final performance.

[0110] (3) Simple supported beam notched impact strength: only Examples 1 to 4 and Comparative Examples 1 to 2 meet the requirements, while Comparative Examples 3 to 4 do not meet the requirements. Comparative Example 2 has the best performance, indicating that the polypropylene material of the present application can absorb higher energy when destroyed and has better toughness. Although Comparative Example 3 also contains two types of polypropylene, the blending effect of the two types of polypropylene is not as good as that of the present application, and the interface compatibility is relatively general. When subjected to high-energy impact and with a notch, it is more likely to break. In Comparative Example 4, the mixing of high-density polyethylene makes it more difficult to balance the system, which easily causes mutual hindrance between the two melts of polypropylene and polyethylene, affecting the final performance.

[0111] (4) Simple supported beam unnotched impact strength: Examples 1 to 4 and Comparative Examples 1 to 4 all meet the requirements.

[0112] In summary, it is shown that the polypropylene material of the present application meets the various indicators described above, and different embodiments have reached higher or highest levels (compared in Examples 1 to 4 and Comparative Examples 1 to 4). The present application can select different raw material formulations according to actual needs, and the material strength and toughness are better, and the comprehensive performance is better than that of Comparative Examples 1 to 4. In addition, the present application does not need to add too many additional additives, such as nucleating agents and compatibilizers. Of course, additives may improve the performance of a certain item (such as Comparative Example 2), but the present application can achieve better comprehensive performance while reducing additives, and also reduces the difficulty of operation, is not restricted by additives, and does not need to add too many reagents to the mixture in order to enhance performance. Some additives may also affect the environment and are not conducive to environmental protection.

[0113] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention is described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A high-strength and high-toughness polypropylene material for automotive cable ties, characterized in that: The material consists of the following components in parts by weight: The first component polypropylene 60-80 parts, the second component polypropylene 15-40 parts, antioxidant 0.1-0.3 parts, black masterbatch 0.5-3 parts; The first component polypropylene is modified polypropylene, and the second component polypropylene is random copolymer polypropylene; The modified polypropylene is HCPP, and the HCPP is SABIC CX03-82; the random copolymer polypropylene is Yanshan Petrochemical B8101.

2. The high-strength and high-toughness polypropylene material for automobile cable ties according to claim 1, characterized in that: The antioxidant includes at least one of a phenolic antioxidant, an amine antioxidant, and a phosphite antioxidant.

3. The high-strength and high-toughness polypropylene material for automobile cable ties according to claim 1, characterized in that: The black masterbatch is a carbon black masterbatch.

4. A method for preparing the high-strength and high-toughness polypropylene material for automobile cable ties according to any one of claims 1 to 3, characterized in that: The following steps are involved: S1. Prepare materials: weigh the raw materials; S2, premixing: putting the first component polypropylene, the second component polypropylene, the antioxidant, and the black masterbatch into a mixer, mixing to obtain a premix; S3, mixing: adding the premix into a twin-screw extruder, and melt-extrude to obtain a molten material; S4, granulation: the molten material is stretched, cooled, and pelletized to obtain a polypropylene material.

5. The method for preparing the high-strength and high-toughness polypropylene material for automobile cable ties according to claim 4, characterized in that: In step S2, mixing is performed for 8 to 15 minutes; in step S3, the temperature of each zone of the screw is 190° C. to 230° C., and the screw speed is 250 to 600 rpm.

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