Transparent polypropylene material and preparation method thereof

Abstract

The invention discloses a transparent polypropylene material. The transparent polypropylene material comprises the following components: polypropylene, a two-component nucleating agent, an acid neutralizer, an antioxidant and a lubricant, wherein the two-component nucleating agent comprises a first nucleating agent and a second nucleating agent; the first nucleating agent is 1, 2, 3-trideoxy-4, 6: 5, 7-bis-O-[(4-propylphenyl) methylene]-nonanol (TBPMN), and the second nucleating agent is 1, 2, 3-trideoxy-4, 6: 5, 7-bis-O-[(4-propylphenyl) methylene]-nonanol (TBPMN); the second nucleating agent is an organic silicon reagent which can be hydrolyzed and self-polymerized to generate nanoparticles. The transparent polypropylene material provided by the invention can endow the polypropylene material with excellent physical and mechanical properties under the condition of remarkably reducing the haze of polypropylene.

Description

Technical Field

[0001] The present invention belongs to the technical field of polymer materials, and relates to a transparent polypropylene material and a preparation method thereof. Background Art

[0002] Polypropylene has the advantages of good mechanical properties, non-toxic and harmless, good chemical stability, good heat resistance, easy processing and molding, etc., and is widely used in the fields of automobile manufacturing, household appliances, daily necessities, packaging materials, etc., and has become the resin with the fastest growth rate and the most active new product research and development among the five general-purpose resins. Since polypropylene is a semi-crystalline polymer, directly processing and molding will form spherulites with sizes larger than the visible light wavelength (400 - 700 nm), resulting in scattering and refraction phenomena when incident light passes through the spherulites. At the same time, due to the different refractive indices of the crystalline region and the non-crystalline region to light, scattering and refraction phenomena will also occur when visible light passes through the interface between the two, significantly reducing the transparency of the material. Therefore, polypropylene products generally appear in a semi-transparent or opaque state, and their applications in the fields of transparent packaging and engineering materials are severely limited. Therefore, in order to improve the market value of polypropylene, it is necessary to carry out anti-clouding modification on it.

[0003] The nucleating agent anti-fogging method is currently the most economical and effective method. Among them, sorbitol compounds are the most widely used type of nucleating agent, almost occupying 80% of the nucleating agent market share, and can effectively improve the optical properties and other physical and mechanical properties of polypropylene. In the past half century, it has been widely researched and applied. Adding sorbitol compounds can greatly improve the optical properties and mechanical properties of polypropylene materials, and enhance the use value of polypropylene. However, when using sorbitol nucleating agents alone, there are disadvantages such as a large addition amount and limited anti-fogging efficiency. At the same time, sorbitol nucleating agents will assemble to form a three-dimensional network structure in the polypropylene melt, causing the gelation of the system and a sudden increase in the melt viscosity during the processing. This phenomenon will have a negative impact on the forming process of the material, especially restricting the increase of the orientation and draw ratio of the material during the melt spinning process. It is found that when modifying polypropylene by using polyhedral oligomeric silsesquioxane (POSS) in combination with sorbitol nucleating agents, the silanol groups on the surface of POSS can block the nanofiber network formed by the self-recognition of the head and tail of the nucleating agent molecules in the polypropylene melt, thereby inhibiting the gelation of sorbitol nucleating agents. However, this method cannot effectively reduce the haze of polypropylene, and POSS is expensive and not suitable for industrial applications. To address this problem, if sorbitol compounds are used as the first nucleating agent and nanoparticles that can induce the crystallization of polypropylene are introduced as the second nucleating agent, and the two nucleating agents are used in combination to anti-fog and modify polypropylene, on the one hand, the dosage of sorbitol compounds can be reduced and its gelation effect can be weakened, on the other hand, more nucleation sites can be provided for the crystallization of polypropylene, refining the crystal grains of polypropylene, and thereby improving its optical properties. In addition, when adding sorbitol nucleating agents alone to anti-fog and modify polypropylene, there is also a problem that the optical properties of products in different processing batches fluctuate. Reasonably selecting other processing aids can improve the processing fluidity of the polypropylene melt, improve the dispersibility of the nucleating agent in the polypropylene melt, solve the problem of unstable optical properties of polypropylene products, and further enhance the transparency of the product.

[0004] Chinese Patent CN201210559922.7 discloses a transparent polypropylene and its preparation method, which uses a phosphate nucleating agent and a sorbitol nucleating agent for compounding; however, the preparation method has cumbersome steps and high costs.

[0005] Chinese Patent CN202011170909.3 discloses a transparent polypropylene material and its preparation method, which selects polypropylene containing 1-5 wt% ethylene and adds a sorbitol nucleating agent; however, the preparation method has relatively high costs and requires difficult technology and high operation difficulty.

[0006] Chinese Patent CN201510998254.1 discloses a homopolymer transparent polypropylene composition, which is characterized in that the composition is prepared from raw materials including homopolymer polypropylene resin, transparent nucleating agent, hindered phenol antioxidant, phosphite antioxidant and acid neutralizer; however, this polypropylene composition uses a coal-based homopolymer polypropylene resin with a relatively wide molecular weight distribution range, so the impact strength and heat distortion temperature of this composition are relatively low, and its scope of use is limited.

[0007] Chinese Patent CN202111119547.X discloses a low-density, low-shrinkage and high-gloss polypropylene composite, which comprises the following components in parts by weight: 14-40% of homopolymer polypropylene, 15-40% of block copolymer polypropylene, 10-35% of toughening agent, and 5-45% of inorganic filler; however, the content of inorganic filler in this polypropylene composite is relatively high, so its light transmittance is poor and it is not suitable for the field of high-transparency materials. Summary of the Invention

[0008] Due to problems such as a large amount of sorbitol-based nucleating agent being required in the transparency-improving modification of polypropylene, limited transparency-improving efficiency, easy formation of gels in the polypropylene melt, and fluctuations in the optical properties of products in different processing batches, the present invention intends to use a two-component nucleating agent for the transparency-improving modification of polypropylene and add a lubricant to enhance the compatibility between the nucleating agent and the polypropylene matrix material. As the second nucleating agent, the silicone reagent can further improve the optical properties of the polypropylene material on the basis of the sorbitol-based compound as the first nucleating agent to improve the transparency of the product.

[0009] To achieve the above object, the present invention provides a transparent polypropylene material, which comprises the following components:

[0010] Polypropylene, two-component nucleating agent, acid neutralizer, antioxidant and lubricant;

[0011] Wherein, the two-component nucleating agent includes a first nucleating agent and a second nucleating agent; the first nucleating agent is 1,2,3-trideoxy-4,6:5,7-bis-O-[(4-propylphenyl)methylene]-nonanol (TBPMN); the second nucleating agent is a silicone reagent that can hydrolyze and self-polymerize to form nanoparticles.

[0012] The silicone reagent that can hydrolyze and self-polymerize to form nanoparticles in the present invention refers to a silicone reagent containing three alkoxy groups and one substituted alkyl group.

[0013] According to the specific embodiments of the present invention, the silicone reagent that can hydrolyze and self-polymerize to form nanoparticles is selected from one of γ-methacryloxypropyltrimethoxysilane and γ-glycidoxypropyltrimethoxysilane.

[0014] According to a specific embodiment of the present invention, based on 100 parts by weight of polypropylene, the addition amount of the first nucleating agent is 0.05 to 0.3 parts, and the addition amount of the second nucleating agent is 0.05 to 0.3 parts.

[0015] According to a specific embodiment of the present invention, the weight ratio of the first nucleating agent to the second nucleating agent is 3:1 to 1:2.

[0016] According to a specific embodiment of the present invention, based on 100 parts by weight of polypropylene, the addition amount of the acid neutralizer is 0.01 to 0.05 parts.

[0017] According to a specific embodiment of the present invention, based on 100 parts by weight of polypropylene, the addition amount of the antioxidant is 0.01 to 0.3 parts.

[0018] According to a specific embodiment of the present invention, based on 100 parts by weight of polypropylene, the addition amount of the lubricant is 0.8 to 1.3 parts.

[0019] According to a specific embodiment of the present invention, the acid neutralizer is one of zinc stearate, calcium stearate, and aluminum stearate.

[0020] According to a specific embodiment of the present invention, the lubricant is one of polypropylene wax and polyethylene wax, preferably polypropylene wax.

[0021] According to a specific embodiment of the present invention, the antioxidant is a compound of a primary antioxidant and a secondary antioxidant. The primary antioxidant is one of pentaerythritol tetra[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] and 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene. The secondary antioxidant is one of tris(2,4-di-tert-butylphenyl) phosphite and tetra(2,4-di-tert-butylphenyl)-4,4'-biphenyl bisphosphite.

[0022] According to a specific embodiment of the present invention, the weight ratio of the primary antioxidant to the secondary antioxidant is 0.1 to 1.0.

[0023] According to a specific embodiment of the present invention, the present invention does not particularly limit the preparation process of the double-component nucleating agent. Preferably, the preparation process of the double-component nucleating agent is as follows: Add 1,2,3-trideoxy-4,6:5,7-bis-O-[(4-propylphenyl)methylene]-nonitol (TBPMN) and a silicone reagent to an ethanol solution, keep the temperature constant, stir, add distilled water, and continue stirring. After the stirring is completed, remove ethanol and water with a rotary evaporator, and then dry in a vacuum drying oven; finally, grind the product with a mortar to obtain the double-component nucleating agent.

[0024] The present invention also provides a method for preparing a transparent polypropylene material, which comprises the following steps: uniformly mixing polypropylene, a first nucleating agent, a second nucleating agent, an antioxidant, an acid neutralizer and a lubricant, and then extruding and pelletizing, and injection molding to obtain the transparent polypropylene material.

[0025] According to a specific embodiment of the present invention, in the preparation method, extrusion granulation is carried out at barrel temperatures of 180°C, 190°C and 185°C in a twin-screw extruder, and injection molding is carried out at a barrel temperature of 190°C and a mold temperature of 60°C in an injection molding machine.

[0026] The present invention uses a two-component nucleating agent to synergistically enhance the transparency of polypropylene, which can greatly improve the transparency of the polypropylene material. The first nucleating agent, TBPMN, is melt-dispersed in the polypropylene melt and preferentially crystallizes and precipitates to form crystal nuclei with a fiber network structure during cooling, which provides nucleation sites for the crystallization of polypropylene. Using an organosilicon reagent as the second nucleating agent can introduce a large number of nano-scale small particles with spherical structures into the original fiber network structure of TBPMN. These nano-scale small particles can provide more crystal nuclei for the crystallization of polypropylene, further improving the nucleation efficiency of polypropylene, thereby increasing the crystallinity of polypropylene and reducing the grain size of spherulites.

[0027] The present invention adds low-molecular-weight wax as a lubricant to improve the processing fluidity of polypropylene. The addition of low-molecular-weight wax can effectively improve the processing fluidity of the polypropylene melt and the mechanical properties of the product, enable polypropylene to be processed and molded at a lower temperature, reduce the processing energy consumption in the actual production process, and also avoid micro-defects such as fisheyes during processing. Adding a lubricant during the processing process of the present invention can not only reduce the friction between molecular chains after melting, but also reduce the adhesion between the melt and the processing equipment, promote the flow of the melt, ensure the smooth progress of the processing process, improve the equipment utilization rate and the finished product rate, and enhance the gloss of the product surface. A large number of experiments of the present invention have proved that when using a two-component nucleating agent and a lubricant to modify polypropylene, the haze of polypropylene can be significantly reduced, and the optical properties of polypropylene products can be improved.

[0028] In summary, the transparent polypropylene material of the present invention can endow the polypropylene material with excellent physical and mechanical properties while significantly reducing the haze of polypropylene. Brief Description of the Drawings

[0029] Figure 1 It is a flowchart for the preparation of the transparent polypropylene material of the present invention. Detailed Description of the Embodiments

[0030] The following details the implementation process and the beneficial effects generated by the present invention through specific embodiments, aiming to help readers better understand the essence and characteristics of the present invention, and shall not be construed as a limitation on the scope of implementation of this case.

[0031] Example 1

[0032] Mix TBPMN, γ-methacryloyloxypropyltrimethoxysilane, polyethylene wax, pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], tris(2,4-di-tert-butylphenyl) phosphite, zinc stearate and polypropylene evenly according to the weight ratio of 0.05∶0.05∶1.1∶0.1∶0.2∶0.03∶100. Extrude and pelletize at the barrel temperatures of 180 °C, 190 °C and 185 °C, and injection mold into a spline at the barrel temperature of 190 °C and the mold temperature of 60 °C to obtain the transparent polypropylene material S1. Relevant characterizations show that the haze of the sample of the transparent polypropylene material is 27.8%, the light transmittance is 83.3%, the tensile strength is 27.5 Mpa, and the impact strength is 6.8 KJ / m 2 。

[0033] Example 2

[0034] Mix TBPMN, γ-methacryloyloxypropyltrimethoxysilane, polyethylene wax, pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], tris(2,4-di-tert-butylphenyl) phosphite, zinc stearate and polypropylene evenly according to the weight ratio of 0.1∶0.1∶1.1∶0.1∶0.2∶0.03∶100. Extrude and pelletize at the barrel temperatures of 180 °C, 190 °C and 185 °C, and injection mold into a spline at the barrel temperature of 190 °C and the mold temperature of 60 °C to obtain the transparent polypropylene material S2. Relevant characterizations show that the haze of the sample of the transparent polypropylene material is 13.2%, the light transmittance is 83.8%, the tensile strength is 32.8 Mpa, and the impact strength is 6.9 KJ / m 2 。

[0035] Example 3

[0036] Mix TBPMN, γ-glycidoxypropyltrimethoxysilane, polyethylene wax, 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene, tris(2,4-di-tert-butylphenyl) phosphite, zinc stearate and polypropylene evenly according to the weight ratio of 0.1∶0.1∶1.1∶0.1∶0.2∶0.02∶100. Extrude and pelletize at the barrel temperatures of 180 °C, 190 °C and 185 °C, and injection mold into a spline at the barrel temperature of 190 °C and the mold temperature of 60 °C to obtain the transparent polypropylene material S3. Relevant characterizations show that the haze of the sample of the transparent polypropylene material is 12.5%, the light transmittance is 83.4%, the tensile strength is 32.5 Mpa, and the impact strength is 6.5 KJ / m 2 。

[0037] Example 4

[0038] Mix TBPMN, γ-methacryloxypropyltrimethoxysilane, polyethylene wax, 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene, tris(2,4-di-tert-butylphenyl) phosphite, zinc stearate and polypropylene evenly according to the weight ratio of 0.2∶0.1∶1.1∶0.1∶0.2∶0.04∶100. Extrude and pelletize at barrel temperatures of 180 °C, 190 °C and 185 °C, and injection mold into a spline at a barrel temperature of 190 °C and a mold temperature of 60 °C to obtain a transparent polypropylene material S4. Relevant characterization shows that the haze of the transparent polypropylene material sample is 11.8%, the light transmittance is 82.6%, the tensile strength is 32.8 Mpa, and the impact strength is 6.8 KJ / m 2 。

[0039] Example 5

[0040] Mix TBPMN, γ-methacryloxypropyltrimethoxysilane, polypropylene wax, pentaerythritol tetra[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], tris(2,4-di-tert-butylphenyl) phosphite, calcium stearate and polypropylene evenly according to the weight ratio of 0.3∶0.1∶1.1∶0.1∶0.2∶0.03∶100. Extrude and pelletize at barrel temperatures of 180 °C, 190 °C and 185 °C, and injection mold into a spline at a barrel temperature of 190 °C and a mold temperature of 60 °C to obtain a transparent polypropylene material S5. Relevant characterization shows that the haze of the transparent polypropylene material sample is 11.5%, the light transmittance is 85.5%, the tensile strength is 33.9 Mpa, and the impact strength is 6.9 KJ / m 2 。

[0041] Example 6

[0042] Mix TBPMN, γ-methacryloxypropyltrimethoxysilane, polypropylene wax, pentaerythritol tetra[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], tetrakis(2,4-di-tert-butylphenyl)-4,4'-biphenyldiphosphite, calcium stearate and polypropylene evenly according to the weight ratio of 0.2∶0.3∶1.1∶0.05∶0.25∶0.03∶100. Extrude and pelletize at barrel temperatures of 180 °C, 190 °C and 185 °C, and injection mold into a spline at a barrel temperature of 190 °C and a mold temperature of 60 °C to obtain a transparent polypropylene material S6. Relevant characterization shows that the haze of the transparent polypropylene material sample is 9.6%, the light transmittance is 87.0%, the tensile strength is 36.1 Mpa, and the impact strength is 6.2 KJ / m 2 。

[0043] Example 7

[0044] Mix TBPMN, γ-glycidoxypropyltrimethoxysilane, polypropylene wax, pentaerythritol tetra[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], tetra(2,4-di-tert-butylphenyl)-4,4'-biphenyldiphosphite, zinc stearate and polypropylene evenly according to the weight ratio of 0.2∶0.2∶1.1∶0.03∶0.25∶0.03∶100. Extrude and pelletize at barrel temperatures of 180 °C, 190 °C and 185 °C, and injection mold into test specimens at a barrel temperature of 190 °C and a mold temperature of 60 °C to obtain the transparent polypropylene material S7. Relevant characterizations show that the haze of the specimen of the transparent polypropylene material is 10.1%, the light transmittance is 85.1%, the tensile strength is 35.9 Mpa, and the impact strength is 6.8 KJ / m 2 。

[0045] Example 8

[0046] Mix TBPMN, γ-methacryloxypropyltrimethoxysilane, polypropylene wax, pentaerythritol tetra[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], tris(2,4-di-tert-butylphenyl) phosphite, calcium stearate and polypropylene evenly according to the weight ratio of 0.3∶0.3∶1.1∶0.05∶0.2∶0.03∶100. Extrude and pelletize at barrel temperatures of 180 °C, 190 °C and 185 °C, and injection mold into test specimens at a barrel temperature of 190 °C and a mold temperature of 60 °C to obtain the transparent polypropylene material S8. Relevant characterizations show that the haze of the specimen of the transparent polypropylene material is 9.9%, the light transmittance is 85.6%, the tensile strength is 35.6 Mpa, and the impact strength is 6.9 KJ / m 2 。

[0047] Example 9

[0048] Mix TBPMN, γ-methacryloxypropyltrimethoxysilane, polypropylene wax, pentaerythritol tetra[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], tris(2,4-di-tert-butylphenyl) phosphite, zinc stearate and polypropylene evenly according to the weight ratio of 0.2∶0.2∶1.1∶0.05∶0.25∶0.01∶100. Extrude and pelletize at barrel temperatures of 180 °C, 190 °C and 185 °C, and injection mold into test specimens at a barrel temperature of 190 °C and a mold temperature of 60 °C to obtain the transparent polypropylene material S9. Relevant characterizations show that the haze of the specimen of the transparent polypropylene material is 9.7%, the light transmittance is 85.9%, the tensile strength is 36.5 Mpa, and the impact strength is 6.6 KJ / m 2 。

[0049] Example 10

[0050] Mix TBPMN, γ-methacryloxypropyltrimethoxysilane, polyethylene wax, pentaerythritol tetra[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], tris(2,4-di-tert-butylphenyl) phosphite, zinc stearate and polypropylene evenly according to the weight ratio of 0.2∶0.2∶0.9∶0.05∶0.25∶0.03∶100. Extrude and pelletize at barrel temperatures of 180 °C, 190 °C and 185 °C, and injection mold into a spline at a barrel temperature of 190 °C and a mold temperature of 60 °C to obtain a transparent polypropylene material S10. Relevant characterization shows that the haze of the sample of the transparent polypropylene material is 10.1%, the light transmittance is 85.2%, the tensile strength is 34.7 Mpa, and the impact strength is 6.9 KJ / m 2 .

[0051] Example 11

[0052] Mix TBPMN, γ-methacryloxypropyltrimethoxysilane, polyethylene wax, pentaerythritol tetra[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], tris(2,4-di-tert-butylphenyl) phosphite, zinc stearate and polypropylene evenly according to the weight ratio of 0.2∶0.2∶1.1∶0.05∶0.25∶0.05∶100. Extrude and pelletize at barrel temperatures of 180 °C, 190 °C and 185 °C, and injection mold into a spline at a barrel temperature of 190 °C and a mold temperature of 60 °C to obtain a transparent polypropylene material S11. Relevant characterization shows that the haze of the sample of the transparent polypropylene material is 10.2%, the light transmittance is 85.5%, the tensile strength is 34.2 Mpa, and the impact strength is 6.4 KJ / m 2 .

[0053] Example 12

[0054] Mix TBPMN, γ-methacryloxypropyltrimethoxysilane, polyethylene wax, pentaerythritol tetra[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], tris(2,4-di-tert-butylphenyl) phosphite, aluminum stearate and polypropylene evenly according to the weight ratio of 0.2∶0.2∶1.3∶0.1∶0.2∶0.03∶100. Extrude and pelletize at barrel temperatures of 180 °C, 190 °C and 185 °C, and injection mold into a spline at a barrel temperature of 190 °C and a mold temperature of 60 °C to obtain a transparent polypropylene material S12. Relevant characterization shows that the haze of the sample of the transparent polypropylene material is 10.0%, the light transmittance is 84.9%, the tensile strength is 33.9 Mpa, and the impact strength is 6.5 KJ / m 2 .

[0055] Example 13

[0056] Mix TBPMN, γ-methacryloyloxypropyltrimethoxysilane, polypropylene wax, pentaerythritol tetra[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], tris(2,4-di-tert-butylphenyl) phosphite, calcium stearate and polypropylene evenly according to the weight ratio of 0.2∶0.2∶0.9∶0.1∶0.2∶0.03∶100. Extrude and pelletize at barrel temperatures of 180 °C, 190 °C and 185 °C, and injection mold into a spline at a barrel temperature of 190 °C and a mold temperature of 60 °C to obtain a transparent polypropylene material S13. Relevant characterizations show that the specimen of the transparent polypropylene material has a haze of 9.0%, a light transmittance of 87.1%, a tensile strength of 36.9 Mpa, and an impact strength of 6.8 KJ / m 2 。

[0057] Example 14

[0058] Mix TBPMN, γ-methacryloyloxypropyltrimethoxysilane, polypropylene wax, pentaerythritol tetra[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], tris(2,4-di-tert-butylphenyl) phosphite, zinc stearate and polypropylene evenly according to the weight ratio of 0.2∶0.2∶1.1∶0.1∶0.2∶0.03∶100. Extrude and pelletize at barrel temperatures of 180 °C, 190 °C and 185 °C, and injection mold into a spline at a barrel temperature of 190 °C and a mold temperature of 60 °C to obtain a transparent polypropylene material S14. Relevant characterizations show that the specimen of the transparent polypropylene material has a haze of 8.9%, a light transmittance of 87.6%, a tensile strength of 36.8 Mpa, and an impact strength of 6.9 KJ / m 2 。

[0059] Example 15

[0060] Mix TBPMN, γ-methacryloyloxypropyltrimethoxysilane, polypropylene wax, pentaerythritol tetra[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], tris(2,4-di-tert-butylphenyl) phosphite, calcium stearate and polypropylene evenly according to the weight ratio of 0.2∶0.2∶1.3∶0.1∶0.2∶0.03∶100. Extrude and pelletize at barrel temperatures of 180 °C, 190 °C and 185 °C, and injection mold into a spline at a barrel temperature of 190 °C and a mold temperature of 60 °C to obtain a transparent polypropylene material S15. Relevant characterizations show that the specimen of the transparent polypropylene material has a haze of 9.5%, a light transmittance of 85.8%, a tensile strength of 36.6 Mpa, and an impact strength of 6.9 KJ / m 2 。

[0061] Comparative Example 1

[0062] The difference from Example 2 is that the second nucleating agent γ-methacryloxypropyltrimethoxysilane is not added, and the addition amount of TBPMN is increased to 0.2.

[0063] Mix TBPMN, polyethylene wax, pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], tris(2,4-di-tert-butylphenyl) phosphite, zinc stearate and polypropylene evenly according to the weight ratio of 0.2∶1.1∶0.1∶0.2∶0.03∶100. Extrude and pelletize at barrel temperatures of 180°C, 190°C and 185°C, and injection mold into a spline at a barrel temperature of 190°C and a mold temperature of 60°C to obtain a transparent polypropylene material D1. Relevant characterizations show that the haze of the sample of the transparent polypropylene material is 16.5%, the light transmittance is 83.5%, the tensile strength is 28.8 Mpa, and the impact strength is 6.1 KJ / m 2 .

[0064] Comparative Example 2

[0065] The difference from Example 2 is that the first nucleating agent TBPMN is not added, and the addition amount of γ-methacryloxypropyltrimethoxysilane is increased to 0.2.

[0066] Mix γ-methacryloxypropyltrimethoxysilane, polyethylene wax, pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], tris(2,4-di-tert-butylphenyl) phosphite, zinc stearate and polypropylene evenly according to the weight ratio of 0.2∶1.1∶0.1∶0.2∶0.03∶100. Extrude and pelletize at barrel temperatures of 180°C, 190°C and 185°C, and injection mold into a spline at a barrel temperature of 190°C and a mold temperature of 60°C to obtain a transparent polypropylene material D2. Relevant characterizations show that the haze of the sample of the transparent polypropylene material is 28.5%, the light transmittance is 82.3%, the tensile strength is 25.5 Mpa, and the impact strength is 5.4 KJ / m 2 .

[0067]

[0068] It can be seen from the results of Comparative Examples 1-2 that when the first nucleating agent and the second nucleating agent are used alone, the polypropylene material has a higher haze and a poorer light transmittance. It can be seen from the results of Example 2 that when the first nucleating agent and the second nucleating agent of the present invention are used in combination, the polypropylene material has a lower haze and a higher light transmittance. Thus, it can be proved that the first nucleating agent and the second nucleating agent play a synergistic role. It can be seen from the results of Examples 1-15 and Comparative Examples 1-2 that the combined use of the first nucleating agent and the second nucleating agent can significantly reduce the haze of polypropylene and improve the optical properties of polypropylene products.

[0069] Of course, the present invention may have many other embodiments. Without departing from the spirit and essence of the present invention, those skilled in the art can make various corresponding changes and modifications according to the present invention. However, these corresponding changes and modifications shall fall within the protection scope of the present invention.

Claims

1. A transparent polypropylene material, characterized in that, It comprises the following components: Polypropylene, a two-component nucleating agent, an acid neutralizer, an antioxidant and a lubricant; Among them, the two-component nucleating agent includes a first nucleating agent and a second nucleating agent; the first nucleating agent is 1,2,3-trideoxy-4,6:5,7-bis-O-[(4-propylphenyl)methylene]-nonanol (TBPMN); the second nucleating agent is an organosilicon reagent that can hydrolyze and self-polymerize to form nanoparticles.

2. The transparent polypropylene material according to claim 1, wherein The organosilicon reagent that can hydrolyze and self-polymerize to form nanoparticles is selected from one of γ-methacryloxypropyltrimethoxysilane and γ-glycidyletheroxypropyltrimethoxysilane.

3. The transparent polypropylene material according to claim 1, characterized in that, Based on 100 parts by weight of polypropylene, the addition amount of the first nucleating agent is 0.05 - 0.3 parts, and the addition amount of the second nucleating agent is 0.05 - 0.3 parts.

4. The transparent polypropylene material according to claim 1, characterized in that, The weight ratio of the first nucleating agent to the second nucleating agent is 3:1 to 1:

2.

5. The transparent polypropylene material according to claim 1, wherein Based on 100 parts by weight of polypropylene, the addition amount of the acid neutralizer is 0.01 - 0.05 parts.

6. The transparent polypropylene material according to claim 1, characterized in that, Based on 100 parts by weight of polypropylene, the addition amount of the antioxidant is 0.01 - 0.3 parts.

7. The transparent polypropylene material according to claim 1, characterized in that, Based on 100 parts by weight of polypropylene, the addition amount of the lubricant is 0.8 - 1.3 parts.

8. The transparent polypropylene material according to claim 1, characterized in that, The acid neutralizer is one of zinc stearate, calcium stearate and aluminum stearate.

9. The transparent polypropylene material according to claim 1, characterized in that, The lubricant is one of polypropylene wax and polyethylene wax.

10. The transparent polypropylene material according to claim 1, wherein The antioxidant is a compound of a primary antioxidant and a secondary antioxidant. The primary antioxidant is one of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] and 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene, and the secondary antioxidant is one of tris(2,4-di-tert-butylphenyl)phosphite and tetrakis(2,4-di-tert-butylphenyl)-4,4'-biphenyldiphosphite.

11. The transparent polypropylene material according to claim 10, wherein The weight ratio of the primary antioxidant to the secondary antioxidant is 0.1 - 1.

0.

12. A method for preparing a transparent polypropylene material according to any one of claims 1-11, characterized in that, It includes the following steps: After uniformly mixing polypropylene, the first nucleating agent, the second nucleating agent, the antioxidant, the acid neutralizer and the lubricant, extruding and pelletizing, and injection molding to obtain a transparent polypropylene material.

Images