High-impact-resistance and high-transparency polypropylene composite material and preparation method thereof

Abstract

The invention provides a high-impact-resistance and high-transparency polypropylene composite material. The high-impact-resistance and high-transparency polypropylene composite material is prepared from the following raw material components in percentage by weight: 69.9 to 94.97 percent of polypropylene base material, 5 to 30 percent of toughening agent and 0.03 to 0.1 percent of nucleating agent. The invention also provides a preparation method of the polypropylene composite material with high impact resistance and high transparency. According to the high-impact-resistance and high-transparency polypropylene composite material provided by the invention, all the raw material components are reasonably combined and proportioned, so that the problem that the impact performance and transparency of polypropylene cannot be synchronously improved is solved, and the high-impact-resistance and high-transparency polypropylene composite material with excellent performance can be obtained. The preparation method of the high-impact-resistance and high-transparency polypropylene composite material provided by the invention is simple and easy to implement, is suitable for large-scale production in thermal forming and blow molding factories, is suitable for packaging foods, medicines and daily necessities, can replace PET or PC, and has a wide market prospect in the fields of packaging materials and the like.

Description

Technical Field

[0001] The invention belongs to the technical field of polymer modified plastics, and in particular relates to a high-impact and high-transparency polypropylene composite material and a preparation method thereof. The high-impact and high-transparency polypropylene composite material has high impact resistance and excellent high transparency, and is particularly suitable for the production of transparent hollow blow molding products and thermoforming sheets. Background Art

[0002] Polypropylene resin has good heat resistance, processing performance and mechanical strength. It also has the characteristics of low density, easy recycling and recyclability. It is widely used in automobiles, electrical appliances, daily necessities, home furnishings and packaging. Transparent polypropylene is widely used in food packaging, medical products, media product packaging, storage boxes, beverage bottles, and milk bottles because of its transparent and beautiful appearance, good hygiene and heat resistance. It is precisely because of the many advantages of transparent polypropylene that it has been rapidly developed around the world since its advent in the early 1980s. In recent years, the consumption of transparent polypropylene in my country has also increased rapidly. In 2020, the annual demand for transparent polypropylene in my country will be about 2 million tons.

[0003] Traditional transparent polypropylene is usually obtained by adding a transparent agent to homopolymer or random copolymer polypropylene. The most prominent problem in current use is that the product has poor impact resistance in low-temperature environments and cannot meet the requirements of damage to refrigerator drawers when subjected to impact. Impact-resistant copolymer polypropylene has greatly improved its low-temperature impact resistance due to the introduction of a rubber phase into the polypropylene matrix. However, due to the large size of the rubber phase, the product has poor transparency and a haze of about 60%, which cannot meet the transparency requirements of many fields.

[0004] When both transparency and high impact resistance are required, the main method currently used is to blend random polypropylene with elastomers such as POP, POE, SEBS, etc. This method can improve the impact resistance of the product to a certain extent. However, on the other hand, this method requires secondary processing, which increases the cost of the product. At the same time, the increase in elastomers increases the haze of the product.

[0005] CN106554448A discloses a high-impact transparent polypropylene. By controlling the process parameters of the gas phase reaction, an ethylene-propylene copolymer with an ethylene content of 4.0-8.0 wt% is prepared, wherein 1-3 wt% participates in the random copolymerization of ethylene-propylene to form a random copolymerized polypropylene, and 3-5 wt% participates in the block copolymerization of ethylene-propylene to form an impact-resistant copolymerized polypropylene. By adding additives such as a transparent agent, the prepared product has good comprehensive transparency and impact resistance. However, the random copolymerized polypropylene and the impact-resistant copolymerized polypropylene formed are both generated in a gas phase reactor. In order to take into account the transparency of the product at the same time, the impact resistance at room temperature is good, but the impact resistance at low temperature (-20° C.) is only 1.2-1.5 kJ / m 2 .

[0006] CN107880402A discloses a high-transparency and high-impact polypropylene resin suitable for blow molding process. A random copolymer of propylene and ethylene with an ethylene content of 3-5wt% and a melt flow rate of 0.1-2.0g / 10min is mixed and extruded with auxiliary transparent nucleating agent, halogen absorber and antioxidant to obtain a product with good transparency and high normal and low temperature impact properties. The product is suitable for preparing central control blow molding products and vacuum forming plates and sheets. However, the prepared transparent impact-resistant product has a low melt flow rate and still low low-temperature impact properties, and cannot meet the higher requirements of daily necessities for low-temperature drop resistance. Summary of the invention

[0007] In order to solve the deficiencies of the prior art, one of the objects of the present invention is to provide a highly impact-resistant and highly transparent polypropylene composite material and a preparation method thereof.

[0008] To this end, the present invention provides a high-impact and high-transparency polypropylene composite material, the raw materials of which include the following components:

[0009] Polypropylene base material 69.9wt%~94.97wt%,

[0010] Toughening agent 5wt%~30wt%,

[0011] Nucleating agent 0.03wt%~0.1wt%.

[0012] As a specific embodiment of the present invention, preferably, the content of each component in the raw material is:

[0013] Polypropylene base material 72.5wt%~94.97wt%,

[0014] Toughening agent 5wt%~30wt%,

[0015] Nucleating agent 0.03wt%~0.1wt%.

[0016] As a specific embodiment of the present invention, preferably, the content of each component in the raw material is:

[0017] Polypropylene base material 81.5wt%~94.97wt%,

[0018] Toughening agent 5wt%~30wt%,

[0019] Nucleating agent 0.03wt%~0.1wt%.

[0020] As a specific embodiment of the present invention, preferably, the melt index of the polypropylene base material is 1.0 to 5.0 g / 10 min at 230° C. and 2.16 kg.

[0021] As a specific embodiment of the present invention, preferably, the polypropylene base material is one of homopolymer polypropylene or random copolymer polypropylene;

[0022] Further preferably, the homopolypropylene has a crystallinity of more than 70%, and / or an isotacticity of more than 98%, and / or a molecular weight distribution coefficient Mw / Mn of 4.0 to 7.0;

[0023] Further preferably, the comonomer of the random copolymer polypropylene is ethylene and / or butene; more preferably, the mass content of repeating units of ethylene and / or butene monomers is 0.5-5%; and / or, the molecular weight distribution coefficient of the random copolymer polypropylene is Mw / Mn=4.0-7.0.

[0024] As a specific embodiment of the present invention, preferably, the toughening agent is NX UltraClearMaxImpact.

[0025] As a specific embodiment of the present invention, preferably, the nucleating agent is 1,3:2,4-di(3,4-dimethyl)benzylidene sorbitol, and more preferably Irgaclear XT 386.

[0026] To this end, the present invention also provides a method for preparing the above-mentioned high-impact and high-transparency polypropylene composite material, comprising the following steps: mixing a polypropylene base material, a toughening agent and a nucleating agent, then melt-extruding, drawing, cooling, granulating, and drying to prepare the polypropylene composite material.

[0027] As a specific embodiment of the present invention, preferably, the mixing conditions include: low speed 0-600r / min, preferably 400-600r / min, mixing for 1-3 minutes, and high speed 800-2000r / min mixing for 1-2 minutes.

[0028] As a specific embodiment of the present invention, preferably, the melt extrusion is carried out in a twin-screw extruder. Further preferably, the rotation speed of the twin-screw extruder is 100-600r / min, and the temperature from feeding to the die is set to: 190℃-200℃, 195℃-205℃, 200℃-210℃, 205℃-215℃, 205-215℃, 200℃-210℃, 195℃-205℃, 190℃-200℃, 185℃-195℃.

[0029] The advantages of the present invention are:

[0030] (1) The high-impact and high-transparency polypropylene composite material provided by the present invention solves the problem that the impact performance and transparency of polypropylene cannot be improved simultaneously through reasonable combination and ratio of the raw material components, and can obtain a high-impact and high-transparency polypropylene composite material with excellent performance.

[0031] (2) The present invention uses a specific toughening agent NX UltraClear MaxImpact, which can be well mixed with polypropylene when the polymer system is extruded from a twin-screw extruder or an injection molding machine, and can effectively improve the impact resistance of the polypropylene composite material without reducing the transparency of the resin.

[0032] (3) The present invention uses a specific nucleating agent Irgaclear XT 386 to improve the transparency of the polypropylene composite material system. Compared with the conventional nucleating agent addition amount of 0.2% to 0.5%wt, it only needs to add 0.03wt% to 0.1wt% to achieve the purpose of improving the transparency of the polypropylene composite material system, which greatly reduces the cost.

[0033] (4) The preparation method of the high-impact and high-transparency polypropylene composite material provided by the present invention is simple and easy to implement, suitable for large-scale production in thermoforming and blow molding factories, suitable for packaging of food, medicine and daily necessities, and can replace PET or PC. It has broad market prospects in the fields of packaging materials. DETAILED DESCRIPTION

[0034] The embodiments of the present invention will be described in detail below in conjunction with the examples, but those skilled in the art will appreciate that the following examples are only used to illustrate the present invention and should not be considered to limit the scope of the present invention. If no specific conditions are specified in the examples, they are carried out according to normal conditions or the conditions recommended by the manufacturer. If the manufacturer is not specified for the reagents or instruments used, they are all conventional products that can be obtained commercially.

[0035] 1. Raw materials

[0036] Random copolymer polypropylene T5015 is a random copolymer polypropylene produced by Sinopec Tianjin Branch, with a trade name of T5015, a melt flow rate of 3 g / 10 min (test conditions: 230° C., 2.16 kg), a comonomer of ethylene, a repeating unit content of ethylene monomer of 1.5% wt, and a molecular weight distribution coefficient of the random copolymer polypropylene of Mw / Mn=5.5;

[0037] Homopolymer polypropylene PPH-E02 is a homopolymer polypropylene produced by Sinopec Tianjin Branch, with a trade name of PPH-E02, a melt flow rate of 1.8 g / 10 min (test conditions: 230° C., 2.16 kg) and a molecular weight distribution coefficient Mw / Mn=5.9;

[0038] Random copolymer polypropylene PPR-EH05 has a melt flow rate of 5.0 g / 10 min (test conditions: 230° C., 2.16 kg), a molecular weight distribution coefficient Mw / Mn=4.5, and a comonomer of ethylene, with a repeating unit content of ethylene monomer of 2.2%wt.

[0039] Homopolymer polypropylene T30S, with a melt flow rate of 3.0 g / 10 min (test conditions: 230° C., 2.16 kg), and a molecular weight distribution coefficient Mw / Mn=5.9;

[0040] The nucleating agent is Irgaclear XT 386 produced by BASF; the toughening agent is NXUltraClear MaxImpact produced by Milliken & Company; POE is a product of ExxonMobil; SEBS is a product of Baling Petrochemical, and the transparent nucleating agent NA-98 is a product of Guangzhou Chenghe.

[0041] (II) Test methods

[0042] Basic mechanical properties test: The simply supported beam notched impact strength is tested according to the national standard GB / T 1043.1-2008; the haze and light transmittance are tested according to the national standard GB / T 2410-2008.

[0043] Example 1

[0044] The raw material components of random copolymer polypropylene T5015, toughening agent NX UltraClear MaxImpact and nucleating agent Irgaclear XT 386 were weighed according to the weight ratio in Table 1, placed in a high-speed mixer, first mixed at a low speed of 600 r / min for 2 minutes, and then mixed at a high speed of 2000 r / min for 1 minute.

[0045] The uniformly mixed raw materials are added into a twin-screw extruder from a main feeding port, and after melt extrusion, drawing, cooling, and granulation, a high-impact and high-transparency composite material is prepared through drying. The speed of the extruder screw is 100-600r / min, and the temperature of the extruder from feeding to the die is set to: 190℃-200℃, 195℃-205℃, 200℃-210℃, 205℃-215℃, 205-215℃, 200℃-210℃, 195℃-205℃, 190℃-200℃, and 185℃-195℃.

[0046] Embodiment 2-9

[0047] The difference between Examples 2-9 and Example 1 is only the weight ratio of each component, see Table 1 for details.

[0048] Example 10

[0049] The raw material components of polypropylene PPH-E02, toughening agent NX UltraClear MaxImpact and nucleating agent Irgaclear XT 386 were weighed according to the weight ratio in Table 1, placed in a high-speed mixer, first mixed at a low speed of 600 r / min for 2 minutes, and then mixed at a high speed of 2000 r / min for 1 minute.

[0050] The uniformly mixed raw materials are added into a twin-screw extruder from a main feeding port, and after melt extrusion, drawing, cooling, and granulation, a high-impact and high-transparency composite material is prepared through drying. The speed of the extruder screw is 100-600r / min, and the temperature of the extruder from feeding to the die is set to: 190℃-200℃, 195℃-205℃, 200℃-210℃, 205℃-215℃, 205-215℃, 200℃-210℃, 195℃-205℃, 190℃-200℃, and 185℃-195℃.

[0051] Examples 11-18

[0052] The difference between Examples 11-18 and Example 10 is only the weight ratio of each component; the difference between Example 10 and Example 1 is that the random copolymer polypropylene T5015 is replaced by homopolymer polypropylene PPH-E02.

[0053] Comparative Example 1

[0054] The difference between Comparative Example 1 and Example 1 is that the raw material itself does not contain a toughening agent and a nucleating agent, and POE is added. The content of each component is shown in Table 1.

[0055] Comparative Example 2

[0056] The difference between Comparative Example 2 and Example 1 is that the raw material is homopolymer polypropylene PPH-E02, which is the same as Example 11 and does not contain toughening agent and nucleating agent. SEBS is added. The content of each component is shown in Table 1.

[0057] Comparative Example 3

[0058] The difference between Comparative Example 3 and Example 1 is that the raw material itself does not contain a toughening agent and a nucleating agent. The content of each component is shown in Table 1.

[0059] Comparative Example 4

[0060] The difference between Comparative Example 4 and Example 1 is that a nucleating agent NA-98 is added. The contents of each component are shown in Table 1.

[0061] Comparative Example 5

[0062] The difference between Comparative Example 5 and Example 1 is: the content of each component. The specific content of each component is shown in Table 1.

[0063] The components and contents of the raw materials used in each embodiment and comparative example are shown in Table 1. In Table 1, unless otherwise specified, the components in the embodiment are in mass percentage. The various properties of the high impact resistance and high transparency polypropylene composite materials prepared in each embodiment and comparative example are shown in Tables 2-4.

[0064] Table 1

[0065]

[0066]

[0067] Table 2

[0068]

[0069] Table 3

[0070]

[0071] Table 4

[0072]

[0073]

[0074] From the test data results of the embodiments and comparative examples in Tables 2-4, it can be found that by comparing embodiments 1-9 with comparative example 1, after adding a toughening agent to the random copolymer polypropylene, the low-temperature impact resistance (-30°C simply supported beam notched impact strength) of the polypropylene composite material can be increased from the original 1.3KJ / m 2 Increased to 7.9KJ / m 2 ; The room temperature impact resistance (23℃ simply supported beam notched impact strength) can be increased from the original 5.25KJ / m 2 Increased to 83.9KJ / m 2 ; Comparing Examples 10-18 with Comparative Example 2, after adding toughening agent to homopolymer polypropylene, the low-temperature impact resistance (-30℃ simply supported beam notched impact strength) of polypropylene composite material can be increased from the original 0.69KJ / m 2 Increased to 4.6KJ / m 2 ; The room temperature impact resistance (23℃ simply supported beam notched impact strength) can be increased from the original 4.83KJ / m 2 Increased to 64.5KJ / m 2. The conventional toughening agents added in Comparative Examples 1 and 2 also have certain toughening properties for polypropylene composites, but the toughening effect is quite different from that of the present invention. At the same addition amount, the toughening agent selected by the present invention is much more effective than the common toughening agent. In addition, by comparing Examples 1-18 with Comparative Examples 3 and 4, it can be found that after adding a nucleating agent (0.03wt% to 0.1wt%), the haze of the polypropylene composite material can be reduced from the original 16.1 to 9.0. The addition amount of the conventional nucleating agent is 0.2% to 0.5%wt, which cannot achieve the effect of the additive of the present invention at the same addition amount.

[0075] It can be seen from the above embodiments and comparative examples that the auxiliary agent formulation system provided by the present invention can not only improve the transparency of polypropylene resin, but also significantly improve the normal low temperature impact resistance of the resin, taking into account both high transparency and high toughness, and has a good effect on homopolymer polypropylene and random copolymer polypropylene.

[0076] In summary, the polypropylene composite material prepared by introducing nucleating agents and toughening agents into the polypropylene system has the characteristics of high impact resistance and good transparency, which can meet the high requirements for anti-drop performance of food and daily necessities packaging. In addition, the preparation method is simple, which is conducive to large-scale implementation and promotion by product manufacturers.

[0077] The above description of the embodiments is to facilitate the understanding and application of the present invention by those skilled in the art. It is obvious that those familiar with the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative work. Therefore, the present invention is not limited to the embodiments herein, and improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the present invention should be within the scope of protection of the present invention. For example, if other functional additives are added to the preparation components of the present invention to make the composite material have corresponding properties, it is also protected by the present invention.

Claims

1. A highly impact-resistant and highly transparent polypropylene composite material, characterized in that: Its raw materials include the following components: Polypropylene base material 69.9wt%~94.97wt%, Toughening agent 5wt%~30wt%, Nucleating agent 0.03wt%~0.1wt%.

2. The polypropylene composite material according to claim 1, characterized in that: The content of each component in the raw material is: Polypropylene base material 72.5wt%~94.97wt%, Toughening agent 5wt%~30wt%, Nucleating agent 0.03wt%~0.1wt%.

3. The polypropylene composite material according to claim 2, characterized in that: The content of each component in the raw material is: Polypropylene base material 81.5wt%~94.97wt%, Toughening agent 5wt%~30wt%, Nucleating agent 0.03wt%~0.1wt%.

4. The polypropylene composite material according to any one of claims 1 to 3, characterized in that The melt index of the polypropylene base material is 1.0 to 5.0 g / 10 min at 230° C. and 2.16 kg.

5. The polypropylene composite material according to any one of claims 1 to 4, characterized in that The polypropylene base material is one of homopolymer polypropylene or random copolymer polypropylene; Preferably, the homopolypropylene has a crystallinity of more than 70%, and / or an isotacticity of more than 98%, and / or a molecular weight distribution coefficient Mw / Mn of 4.0 to 7.0; Preferably, the comonomer of the random copolymer polypropylene is ethylene and / or butene; more preferably, the mass content of the repeating units of ethylene and / or butene monomers is 0.5-5%; and / or the molecular weight distribution coefficient Mw / Mn of the random copolymer polypropylene is 4.0-7.

0.

6. The polypropylene composite material according to any one of claims 1 to 5, characterized in that: The toughening agent is NXUltraClear MaxImpact.

7. The polypropylene composite material according to any one of claims 1 to 6, characterized in that: The nucleating agent is 1,3:2,4-di(3,4-dimethyl)benzylidene sorbitol, preferably Irgaclear XT 386.

8. A method for preparing the high impact resistance and high transparency polypropylene composite material according to any one of claims 1 to 7, characterized in that: The method comprises the following steps: mixing a polypropylene base material, a toughening agent and a nucleating agent, then melt-extruding, drawing, cooling, granulating, and drying to prepare the polypropylene composite material.

9. The preparation method according to claim 8, characterized in that: The mixing conditions include: mixing at a low speed of 0-600 r / min, preferably 400-600 r / min, for 1-3 minutes, and then mixing at a high speed of 800-2000 r / min for 1-2 minutes.

10. The preparation method according to claim 8 or 9, characterized in that: The melt extrusion is carried out in a twin-screw extruder. Preferably, the rotation speed of the twin-screw extruder is 100-600r / min, and the temperature from feeding to the die is set to: 190℃-200℃, 195℃-205℃, 200℃-210℃, 205℃-215℃, 205-215℃, 200℃-210℃, 195℃-205℃, 190℃-200℃, 185℃-195℃.

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