Highly transparent and high gloss polypropylene material and its preparation method

Abstract

The application discloses a kind of high transparent high gloss polypropylene material and preparation method thereof, belong to high polymer material technical field.The high transparent high gloss polypropylene material includes the following weight parts of component: polypropylene powder 100 parts, nucleating agent 0.1-0.3 parts, graphene transmittance enhancer master batch 0.1-0.25 parts, antioxidant 0.05-0.2 parts, acid absorbent 0.01-0.05 parts;The nucleating agent is sorbitol class transparent agent.The application adopts sorbitol class transparent agent and graphene transmittance enhancer master batch compound, can effectively improve the gloss of product, while reducing the haze of product, to improve the transparency of product.

Description

Technical Field

[0001] This invention relates to the field of polymer materials technology, specifically to a high-transparency, high-gloss polypropylene material and its preparation method. Background Technology

[0002] Polypropylene is a semi-crystalline plastic prepared by polymerizing propylene. It is widely used due to its low density and low price. Random polypropylene is used in transparent parts because of its good transparency and toughness. Most existing transparent polypropylene plastics use random copolymer polypropylene as the base resin and add sorbitol-based transparent agents, but the transparency of the resulting products still needs improvement.

[0003] High-end transparent polypropylene from overseas mainly focuses on metallocene transparent random copolymer polypropylene, which has very little extractables and odor. Compared to random copolymer polypropylene manufactured using traditional Ziegler-Natta catalysts, its transparency is significantly improved, and its melt strength and ductility are also higher. Currently, metallocene transparent random copolymer polypropylene is mainly produced by international giants such as ExxonMobil, LyondellBasell, Total, and JPP. Domestically, Yanshan Petrochemical has officially put into production ultra-high melt index polypropylene using metallocene catalysts, establishing an industrial process. In the future, it will inevitably develop metallocene transparent random copolymer polypropylene, and its price will certainly be lower than imported products, which will put greater pressure on ordinary random transparent polypropylene. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a high-transparency, high-gloss polypropylene material and its preparation method. This material uses a compound of sorbitol-based transparent agents and graphene anti-reflection masterbatch, which can not only reduce the haze of the material but also improve its gloss.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows: a high-transparency, high-gloss polypropylene material, comprising the following components in parts by weight: 100 parts of polypropylene powder, 0.1-0.3 parts of nucleating agent, 0.1-0.25 parts of graphene anti-reflection masterbatch, 0.05-0.2 parts of antioxidant, and 0.01-0.05 parts of acid absorber; wherein the nucleating agent is a sorbitol-based transparent agent.

[0006] Preferably, the mass ratio of the graphene antireflection masterbatch to the nucleating agent is 0.2 to 1.25.

[0007] Preferably, the sorbitol-based transparent agent is at least one of 3,4-dimethylbenzylsorbitol and NX8000.

[0008] In the high-transparency, high-gloss polypropylene material of this invention, a sorbitol-based clearing agent and graphene anti-reflective masterbatch are added to the matrix polypropylene resin, which can effectively improve the gloss of the product while reducing its haze. The amount of graphene anti-reflective masterbatch added in this invention is relatively small compared to the overall product, therefore it has no effect on the product's rigidity and heat distortion properties. The mass ratio of sorbitol-based clearing agent to graphene anti-reflective masterbatch has a significant impact on the product. If the mass ratio is too small, the graphene anti-reflective masterbatch will be unevenly dispersed, leading to a decrease in the product's transparency; conversely, if the mass ratio is too large, the effect of the graphene anti-reflective masterbatch will be insignificant, resulting in no significant change in the product's transparency. Therefore, the inventors preferred a mass ratio of graphene antireflection masterbatch to nucleating agent of 0.2 to 1.25, and selected at least one of 3,4-dimethylbenzyl sorbitol and NX8000 as nucleating agent to improve the gloss of the product and reduce the haze of the product.

[0009] Preferably, the graphene antireflective masterbatch is prepared by loading graphene onto random copolymer polypropylene to obtain graphene antireflective masterbatch; the random copolymer polypropylene has a melt index of 40-100 g / 10 min at 230℃ and 2.16 kg load, and an ethylene content of 2.5-2.8 wt%.

[0010] Preferably, the polypropylene powder is random copolymer polypropylene, and the random copolymer polypropylene has a melt index of 15-30 g / 10 min at 230°C and 2.16 kg load, and an ethylene content of 2-2.8 wt%.

[0011] Using high-flowability random copolymer polypropylene resin as a carrier, graphene is loaded onto the random copolymer polypropylene resin. The resulting graphene antireflective masterbatch possesses the high flowability of random copolymer polypropylene resin, which not only helps disperse nucleating agents but also improves the dispersibility of graphene in the product. The graphene antireflective masterbatch interacts with the nucleating agent to improve the gloss of the product and reduce the haze of the product by 12-24%, thereby improving the transparency of the product.

[0012] The preparation method of graphene antireflective masterbatch is more specifically as follows: graphene oxide is placed in water and ultrasonically dispersed, then random copolymer polypropylene is added, stirred, and dried to obtain graphene antireflective masterbatch, wherein the graphene loading is 0.4-1 wt%.

[0013] The stirring can be any stirring operation of the prior art. Preferably, the stirring process parameters are: mechanical stirring for 1-2 hours at a speed of 200-500 rpm.

[0014] The drying process can be any drying operation in the prior art. Preferably, the drying process conditions are: drying at 80-120°C for 2-4 hours.

[0015] Preferably, the ultrasonic parameters of the present invention are: ultrasonic treatment for 0.5-1.5 hours under ultrasonic power of 200-500W.

[0016] Preferably, the antioxidant is composed of a primary antioxidant and a secondary antioxidant, wherein the mass ratio of the primary antioxidant to the secondary antioxidant is 1:2.

[0017] Preferably, the primary antioxidant is a hindered phenolic antioxidant; and the secondary antioxidant is a phosphite antioxidant.

[0018] Preferably, the acid absorbent is at least one of calcium stearate, sodium stearate, zinc stearate, and hydrotalcite.

[0019] The high-transparency, high-gloss polypropylene material described in this invention does not have any special requirements for its preparation method. It can be obtained by preparing the ingredients according to the composition provided in this invention and then processing it according to any existing polypropylene plastic processing method.

[0020] On the other hand, a method for preparing the high-transparency, high-gloss polypropylene material is provided, comprising the following steps: mixing polypropylene powder, nucleating agent, antioxidant, acid absorber and graphene anti-reflection masterbatch evenly, and then extruding and granulating the resulting mixture at 180-200°C to obtain the high-transparency, high-gloss polypropylene material.

[0021] More specifically, the process involves sequentially adding polypropylene powder, nucleating agent, antioxidant, acid absorber, and graphene permeability enhancer into a kneader, placing it in a high-speed mixer, stirring at 1000 rpm for 10–30 minutes, and then extruding and granulating the mixture at 180–200°C.

[0022] The extrusion described can be performed using a twin-screw extruder.

[0023] The extrusion can be any extrusion operation of the prior art. Preferably, the extrusion process conditions are as follows: the melt temperature of the extrusion granulation is 180-200℃, and the screw speed is 300-500 rpm; more specifically: 180℃ in zone 1, 190℃ in zone 2, 200℃ in zone 3, 200℃ in zone 4, 200℃ in zone 5, 200℃ at the die head, and the screw speed is 300-500 rpm.

[0024] Compared with the prior art, the beneficial effects of the present invention are as follows: The present invention uses a compound of sorbitol-based transparent agents and graphene anti-reflection masterbatch, which can effectively improve the gloss of the product and reduce the haze of the product, thereby improving the transparency of the product. Detailed Implementation

[0025] To better illustrate the purpose, technical solution, and advantages of this invention, the invention will be further described below with reference to specific embodiments and comparative examples. The purpose of this description is to provide a detailed understanding of the invention, not to limit its scope. All other embodiments obtained by those skilled in the art without inventive effort are within the protection scope of this invention. Unless otherwise specified, the experimental reagents and instruments involved in the implementation of this invention are commonly used reagents and instruments.

[0026] Examples 1-12 and Comparative Example 1

[0027] An embodiment of the high-transparency, high-gloss polypropylene material and its preparation method according to the present invention is shown in Table 1.

[0028] In Example 6, the nucleating agent was 3,4-dimethylbenzylsorbitol, while in the other examples and Comparative Example 1, the nucleating agent was NX8000.

[0029] The acid absorbent in Example 6 was sodium stearate, while the acid absorbent in the other examples and Comparative Example 1 was hydrotalcite.

[0030] The primary antioxidant is pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], and the secondary antioxidant is (2,4-di-tert-butylphenyl) phosphite triester;

[0031] The polypropylene powder is random copolymer polypropylene, which has a melt index of 20 g / 10 min at 230°C and 2.16 kg load, and an ethylene content of 2.5 wt%.

[0032] The preparation method of the graphene antireflective masterbatch is as follows: graphene oxide is placed in water and ultrasonically sonicated at 300W for 40 minutes. Then, random copolymer polypropylene is added and mechanically stirred at 200rpm for 1 hour. Finally, it is dried at 80℃ for 3 hours to obtain the graphene antireflective masterbatch. The random copolymer polypropylene has a melt index of 50g / 10min at 230℃ and 2.16kg load, an ethylene content of 2.5wt%, and a graphene loading of 0.6wt%.

[0033] The preparation method of the high-transparency, high-gloss polypropylene material includes the following steps: polypropylene powder, nucleating agent, antioxidant, acid absorber, and graphene anti-reflection masterbatch are sequentially added to a kneader, placed in a high-speed mixer, stirred at 1000 rpm for 20 minutes, and then the mixture is melt-extruded and granulated in a twin-screw extruder to obtain the high-transparency, high-gloss polypropylene material. The set temperatures of the twin-screw extruder from the feed port to the die head are as follows: Zone 1 temperature 180℃, Zone 2 temperature 190℃, Zone 3 temperature 200℃, Zone 4 temperature 200℃, Zone 5 temperature 200℃, and Die head temperature 200℃; the screw speed is 350 rpm.

[0034] Table 1. Composition (parts by weight) of the high-transparency, high-gloss polypropylene materials of Examples 1-12 and Comparative Example 1.

[0035]

[0036] Example 1

[0037] The products obtained from each embodiment and comparative example were subjected to light transmittance test, haze test and gloss test.

[0038] (1) Transmittance test and haze test: Each sample was injection molded into a square plate of 60*60*2mm, and the transmittance and haze of the material were tested according to GB / T2410-2008.

[0039] (2) Gloss test: Each sample was injection molded into a square plate of 60*60*2mm. The gloss of the sample was tested using ASTM D523-2014, and the measurement angle was 60°.

[0040] The test results are shown in Table 2.

[0041] Table 2

[0042] 2mm transmittance / % 2mm haze / % gloss Example 1 80.2 35.82 102.8 Example 2 79.8 30.1 105 Example 3 79.0 33.88 102.3 Example 4 77.9 34.6 102 Example 5 77.9 34.7 102 Example 6 77.6 34.2 103 Example 7 78.2 32.6 102 Example 8 77.6 34.6 103 Example 9 80.1 31.9 104 Example 10 76.2 35.4 101 Example 11 75.4 35.7 100 Example 12 77.6 35.9 101 Comparative Example 1 80.7 40.9 101

[0043] As can be seen from Table 1, the introduction of graphene antireflective masterbatch reduces the haze of the product by 12-24% and increases the gloss to 105, indicating that the polypropylene material obtained by this invention has high transparency and high gloss.

[0044] Experimental Example 1

[0045] To investigate the effect of the mass ratio of graphene antireflective masterbatch to nucleating agent on high-transparency, high-gloss polypropylene materials, experimental groups 1-5 were set up. The only difference between experimental groups 1-5 and Example 1 was the different mass ratio of graphene antireflective masterbatch to nucleating agent. The mass ratios of graphene antireflective masterbatch and nucleating agent in experimental groups 1-5 are shown in Table 3. High-transparency, high-gloss polypropylene materials of experimental groups 1-5 were prepared according to the preparation method of Example 1, and the transmittance, haze, and gloss of the obtained products were tested according to the test method of Effect Example 1. The test results are shown in Table 3.

[0046] Table 3

[0047]

[0048] As can be seen from Table 3, the mass ratio of sorbitol-based transparent agent to graphene antireflective masterbatch affects the transparency of polypropylene materials. When the mass ratio of sorbitol-based transparent agent to graphene antireflective masterbatch is too small, the graphene antireflective masterbatch will be unevenly dispersed, resulting in a decrease in product transparency. If the mass ratio of sorbitol-based transparent agent to graphene antireflective masterbatch is too large, the effect of graphene antireflective masterbatch is not obvious, and the change in product transparency is not significant.

[0049] Finally, it should be noted that the above embodiments are used to illustrate the technical solutions of the present invention and not to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A high-transparency, high-gloss polypropylene material, characterized in that, The product comprises the following components in parts by weight: 100 parts polypropylene powder, 0.2 parts nucleating agent, 0.067 parts graphene antireflective masterbatch, 0.15 parts antioxidant, and 0.025 parts acid absorber; wherein the nucleating agent is a sorbitol-based transparent agent. The preparation method of the graphene antireflection masterbatch is as follows: graphene oxide is placed in water and ultrasonically sonicated at 300W for 40 minutes. Then, random copolymer polypropylene is added and mechanically stirred at 200rpm for 1 hour. Finally, it is dried at 80℃ for 3 hours to obtain the graphene antireflection masterbatch. The random copolymer polypropylene has a melt index of 50g / 10min at 230℃ and 2.16kg load, and an ethylene content of 2.5wt%. The graphene loading is 0.6wt%.

2. The high-transparency, high-gloss polypropylene material as described in claim 1, characterized in that, The sorbitol-based transparent agent is at least one of 3,4-dimethylbenzylsorbitol and NX8000.

3. The high-transparency, high-gloss polypropylene material as described in claim 1, characterized in that, The polypropylene powder is random copolymer polypropylene, and the melt index of the random copolymer polypropylene at 230℃ and 2.16kg load is 15-30g / 10min, and the ethylene content is 2-2.8wt%.

4. The high-transparency, high-gloss polypropylene material as described in claim 1, characterized in that, The antioxidant is composed of a primary antioxidant and a secondary antioxidant, and the mass ratio of the primary antioxidant to the secondary antioxidant is 1:

2.

5. The high-transparency, high-gloss polypropylene material as described in claim 4, characterized in that, The primary antioxidant is a hindered phenolic antioxidant; the secondary antioxidant is a phosphite antioxidant.

6. The high-transparency, high-gloss polypropylene material as described in claim 1, characterized in that, The acid absorbent is at least one of calcium stearate, sodium stearate, zinc stearate, and hydrotalcite.

7. A method for preparing a high-transparency, high-gloss polypropylene material as described in any one of claims 1-6, characterized in that, The process includes the following steps: mixing polypropylene powder, nucleating agent, antioxidant, acid absorber and graphene anti-reflection masterbatch evenly, and then extruding and granulating the resulting mixture at 180-200℃ to obtain the high-transparency and high-gloss polypropylene material.

Images