High-transmission high-haze polypropylene and method for preparing the same

Abstract

This invention discloses a high-transparency, high-haze polypropylene material and its preparation method. The material is prepared by mass ratios of 93.2-98 parts polypropylene, 1-4 parts light diffusing agent, 0.2-0.6 parts α-nucleating agent, 0.2-0.6 parts β-nucleating agent, 0.2-0.4 parts antioxidant, 0.2-0.6 parts dispersant, and 0.2-0.6 parts light stabilizer. The nucleating agent is a compound of α-nucleating agent and β-nucleating agent in a mass ratio of 2-5:2-6. By adding specific proportions of α-nucleating agent and β-nucleating agent, this invention induces the polypropylene molecular chains to arrange themselves in a specific manner, thereby forming different spherical (α-crystal form) and rod-shaped (β-crystal form) crystal structures. This causes optical fibers that pass through the material surface and into the matrix to undergo multiple refractions before penetrating the matrix, thus increasing the path length of light within the material and enabling the material to maintain high transparency while exhibiting higher haze.

Description

Technical Field

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

[0002] Polypropylene (PP) is a thermoplastic with excellent comprehensive mechanical properties, lightweight, easy processing, and chemical resistance, making it widely used in the automotive, home appliance, and packaging industries. However, in some specialized applications, such as lamp shades and automotive headlight housings, polypropylene requires high light transmittance to ensure sufficient light penetration for illumination. Simultaneously, while pursuing high light transmittance, the material also needs higher haze, meaning light is scattered as it passes through, blurring the light source and achieving a "see the light but not the source" effect.

[0003] Furthermore, with the rapid development of new energy vehicles, car designs are increasingly emphasizing aesthetics and personalization. Nowadays, traditional grilles have been removed from cars, replaced by ambient lighting bumpers that allow light to pass through. This places high demands on polypropylene materials in terms of light transmittance and low haze. Summary of the Invention

[0004] The purpose of this invention is to provide a high-transparency, high-haze polypropylene material and its preparation method, so as to solve the problems mentioned in the background art. Through the design of the formula, a modified polypropylene material with higher transparency and haze can be obtained.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] A high-transparency, high-haze polypropylene material is prepared from the following components in parts by weight: 93.2-98 parts polypropylene, 1-4 parts light diffusing agent, 0.6-1.1 parts nucleating agent, 0.2-0.4 parts antioxidant, 0.2-0.6 parts dispersant, and 0.2-0.6 parts light stabilizer;

[0007] The nucleating agent is composed of α-nucleating agent and β-nucleating agent in a mass ratio of 2-5:2-6.

[0008] In a further embodiment, the polypropylene is homopolymer polypropylene or random copolymer polypropylene.

[0009] In a further embodiment, the light diffusing agent is an organosilicon numerical spherical micronized light diffusing agent.

[0010] In a further embodiment, the α-nucleating agent is one of dimethicone (DBS) and its derivatives, aromatic phosphate salts, or substituted benzoates;

[0011] The β-nucleating agent is an aromatic amide compound.

[0012] In a further embodiment, the antioxidant is at least one of hindered phenolic antioxidants, phosphite antioxidants, and thioester antioxidants.

[0013] In a further embodiment, the dispersant is a silicone-based lubricant.

[0014] In a further embodiment, the light stabilizer is at least one selected from phenyl benzoate, 2-(2-hydroxy-5-methylphenyl)benzotriazole, 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-n-octyloxybenzophenone, 2-(2-hydroxy-3,5-di-tert-phenyl)-5-chlorobenzotriazole, and resorcinol monobenzoate.

[0015] The second objective of this invention is to provide a method for preparing the aforementioned high-transparency, high-haze polypropylene material, comprising the following steps:

[0016] Weigh out polypropylene, light diffusing agent, nucleating agent, antioxidant, dispersant, and light stabilizer according to the mass ratio, mix them evenly, and feed them into a twin-screw extruder through the main feed port; after mixing, extrusion, stranding, and pelletizing, high-transparency and high-haze polypropylene material is obtained.

[0017] In a further embodiment, the temperature of each zone of the twin-screw extruder is 180-240℃; the screw speed is 200-600 r / min.

[0018] The present invention has the following beneficial effects:

[0019] This invention uses homopolymer or random copolymer polypropylene as the base material to ensure excellent transparency of the modified material. Simultaneously, a specific ratio of α-nucleating agent and β-nucleating agent is added. These two nucleating agents play a crucial role in the polypropylene crystallization process, inducing the polypropylene molecular chains to arrange themselves in a specific manner, thereby forming different crystal forms. Specifically, the polypropylene base material alternately forms spherical (α-crystal form) and rod-shaped (β-crystal form) crystal forms. The alternation of these two crystal forms causes optical fibers that penetrate the material matrix through the material surface to undergo multiple refractions before passing through the matrix. This multiple refraction increases the path length of light within the material, resulting in higher haze. The α-nucleating agent and β-nucleating agent are both small in size and do not affect the material's transparency. Furthermore, by precisely controlling the mass ratio of α-nucleating agent to β-nucleating agent at 2-5:2-6, a good balance between transparency and haze can be achieved.

[0020] In addition, this application also incorporates an organosilicon numerical spherical micronized light diffusing agent (hereinafter referred to as organosilicon light diffusing agent). Its microsphere structure forms tiny unevenness in the PP base material, causing light to undergo multiple refractions and scatterings during the transmission process, thereby further improving the haze and uniformity of the PP material.

[0021] Therefore, this invention, through the action of nucleating agents and light diffusing agents, can prepare polypropylene materials with high transparency and high haze. This allows them to be used in packaging, lamp housings, and transparent bumpers, among other applications. Detailed Implementation

[0022] To facilitate understanding of the present invention, a more comprehensive description will be given below with reference to specific embodiments. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the disclosure of the present invention.

[0023] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

[0024] The specific information of the raw materials used in the following examples and comparative examples is as follows:

[0025] Random copolymer polypropylene, with Sinopec as the preferred manufacturer, grade PP F800E;

[0026] Homopolymer polypropylene, preferably manufactured by Shanghai SECCO, grade PP S2040;

[0027] The preferred manufacturer of the light diffusing agent is Shin-Etsu Chemical Silicon Numerical Spherical Micro Powder Light Diffusing Agent from Japan, with the brand name KMP-590.

[0028] The β-nucleating agent is an aromatic amide compound, and the preferred manufacturer is Shanxi Chemical Research Institute, with the brand name TMB-5.

[0029] Among the α-nucleating agents: aromatic phosphate salts include sodium 2,2'-methylene bis(4,6-di-tert-butylphenyl) phosphate (Japan Edico, brand name NA-11) and organophosphate polypropylene (Shanxi Chemical Research Institute, brand name NA-21). In the embodiments of this application, NA-21 is preferred.

[0030] Guangdong Weilinna New Material Technology Co., Ltd. is a preferred alternative to benzoates.

[0031] Dimethicone includes Gelaalld from Rika Co., Ltd., and Milliden 3905, Millid 3940, and Millid 3988 from Milliken, Inc., USA. In the embodiments of this application, Milliden 3905 from Milliken, Inc., is preferred.

[0032] The preferred hindered phenolic antioxidant is BASF's antioxidant 1010;

[0033] Phosphite antioxidants are preferably BASF's antioxidant 168;

[0034] Thioester antioxidants are preferably DSTDP (octadecyl thiodipropionate) from Yatefant & Kojuya.

[0035] The preferred dispersant is E525, manufactured by Evonik Degussa.

[0036] Light stabilizer 1 is 2-(2-hydroxy-5-methylphenyl)benzotriazole, manufactured by Solvay Chemicals Ltd.

[0037] Light stabilizer 2 is 2,4-dihydroxybenzophenone;

[0038] Light stabilizer 2 is phenyl o-hydroxybenzoate.

[0039] All of the above materials are commercially available standard products.

[0040] It is understood that the above-mentioned raw materials and reagents are merely examples of some specific embodiments of the present invention, making the technical solution of the present invention clearer, and do not mean that the present invention can only use the above-mentioned reagents. The specific scope shall be determined by the claims. In addition, unless otherwise specified, "parts" in the examples and comparative examples refer to parts by weight.

[0041] Any range described in this invention includes the endpoint, any value between the endpoints, and any subrange consisting of the endpoint or any value between the endpoints.

[0042] Example 1:

[0043] 95 parts of PP F800E, 3 parts of light diffusing agent KMP-590, 0.3 parts of α nucleating agent NA-21, 0.5 parts of β nucleating agent TMB-5, 0.3 parts of antioxidant 1010, 0.4 parts of dispersant E525, and 0.5 parts of light stabilizer 1 were mixed evenly and fed into a twin-screw extruder through the main feed port. After mixing, extrusion, stranding, and pelletizing, polypropylene composite material was obtained.

[0044] The process temperatures of the twin-screw extruder from the feed inlet to the die are as follows: Zone 1 190℃, Zone 2 200℃, Zone 3 200℃, Zone 4 210℃, Zone 5 210℃, Zone 6 220℃, Zone 7 220℃, Zone 8 220℃, and Zone 9 210℃. The side feed inlet is located in Zone 8, and the screw speed is 300 r / min.

[0045] Example 2:

[0046] 96 parts of PP F800E, 2 parts of light diffusing agent KMP-590, 0.4 parts of α nucleating agent NA-21, 0.3 parts of β nucleating agent TMB-5, 0.4 parts of antioxidant 1010, 0.5 parts of dispersant E525, and 0.4 parts of light stabilizer 1 were mixed evenly and fed into a twin-screw extruder through the main feed port. After mixing, extrusion, stranding, and pelletizing, polypropylene composite material was obtained.

[0047] The process temperatures of the twin-screw extruder from the feed inlet to the die are as follows: Zone 1 210℃, Zone 2 210℃, Zone 3 220℃, Zone 4 220℃, Zone 5 23℃, Zone 6 240℃, Zone 7 230℃, Zone 8 220℃, and Zone 9 210℃. The side feed inlet is located in Zone 8, and the screw speed is 400 r / min.

[0048] Example 3:

[0049] 94.9 parts of PP F800E, 3 parts of light diffusing agent KMP-590, 0.5 parts of α nucleating agent NA-21, 0.6 parts of β nucleating agent TMB-5, 0.3 parts of antioxidant 168, 0.3 parts of dispersant E525, and 0.4 parts of light stabilizer 2 were mixed evenly and fed into a twin-screw extruder through the main feed port. After mixing, extrusion, stranding, and pelletizing, polypropylene composite material was obtained.

[0050] The process temperatures of the twin-screw extruder from the feed inlet to the die are as follows: Zone 1 200℃, Zone 2 210℃, Zone 3 210℃, Zone 4 220℃, Zone 5 220℃, Zone 6 230℃, Zone 7 220℃, Zone 8 220℃, and Zone 9 210℃. The side feed inlet is located in Zone 8, and the screw speed is 500 r / min.

[0051] Example 4:

[0052] 7.8 parts of PP S20409, 1 part of light diffusing agent KMP-590, 0.4 parts of α-nucleating agent replacing benzoate, 0.2 parts of β-nucleating agent TMB-5, 0.2 parts of antioxidant DSTDP, 0.2 parts of dispersant E525, and 0.2 parts of light stabilizer 3 were mixed evenly and fed into a twin-screw extruder through the main feed port. After mixing, extrusion, stranding, and pelletizing, a high-transparency and high-haze polypropylene composite material was obtained.

[0053] The process temperatures of the twin-screw extruder from the feed inlet to the die are as follows: Zone 1 180℃, Zone 2 190℃, Zone 3 190℃, Zone 4 190℃, Zone 5 200℃, Zone 6 200℃, Zone 7 210℃, Zone 8 210℃, and Zone 9 210℃. The side feed inlet is located in Zone 8, and the screw speed is 200 r / min.

[0054] Example 5:

[0055] 93.8 parts of PP S2040, 4 parts of light diffusing agent KMP-590, 0.2 parts of α nucleating agent Millad3905, 0.4 parts of β nucleating agent TMB-5, 0.2 parts of antioxidant 168, 0.2 parts of antioxidant DSTDP, 0.6 parts of dispersant E525, 0.2 parts of light stabilizer 1, and 0.4 parts of light stabilizer 2 were mixed evenly and fed into a twin-screw extruder through the main feed port. After mixing, extrusion, stranding, and pelletizing, polypropylene composite material was obtained.

[0056] The process temperatures of the twin-screw extruder from the feed inlet to the die are as follows: Zone 1 220℃, Zone 2 220℃, Zone 3 220℃, Zone 4 230℃, Zone 5 230℃, Zone 6 240℃, Zone 7 220℃, Zone 8 220℃, and Zone 9 210℃. The side feed inlet is located in Zone 8, and the screw speed is 600 r / min.

[0057] Comparative Example 1:

[0058] Mix 95.8 parts of PP F800E, 3 parts of light diffusing agent KMP-590, 0.3 parts of antioxidant 1010, 0.4 parts of dispersant E525, and 0.5 parts of light stabilizer evenly, and feed the mixture into a twin-screw extruder through the main feed port; after mixing, extrusion, stranding, and pelletizing, the polypropylene composite material is obtained.

[0059] The process temperatures of the twin-screw extruder from the feed inlet to the die are as follows: Zone 1 190℃, Zone 2 200℃, Zone 3 200℃, Zone 4 210℃, Zone 5 210℃, Zone 6 220℃, Zone 7 220℃, Zone 8 220℃, and Zone 9 210℃. The side feed inlet is located in Zone 8, and the screw speed is 300 r / min.

[0060] Comparative Example 2:

[0061] Mix 95.3 parts of PP F800E, 3 parts of light diffusing agent KMP-590, 0.5 parts of β nucleating agent TMB-5, 0.3 parts of antioxidant 1010, 0.4 parts of dispersant E525, and 0.5 parts of light stabilizer 1 evenly, and feed the mixture into a twin-screw extruder through the main feed port; after mixing, extrusion, stranding, and pelletizing, the polypropylene composite material is obtained.

[0062] The process temperatures of the twin-screw extruder from the feed inlet to the die are as follows: Zone 1 190℃, Zone 2 200℃, Zone 3 200℃, Zone 4 210℃, Zone 5 210℃, Zone 6 220℃, Zone 7 220℃, Zone 8 220℃, and Zone 9 210℃. The side feed inlet is located in Zone 8, and the screw speed is 300 r / min.

[0063] Comparative Example 3:

[0064] 95.5 parts of PP F800E, 3 parts of light diffusing agent KMP-590, 0.3 parts of α nucleating agent NA-21, 0.3 parts of antioxidant 1010, 0.4 parts of dispersant E525, and 0.5 parts of light stabilizer 1 were mixed evenly and fed into a twin-screw extruder through the main feed port. After mixing, extrusion, stranding, and pelletizing, polypropylene composite material was obtained.

[0065] The process temperatures of the twin-screw extruder from the feed inlet to the die are as follows: Zone 1 190℃, Zone 2 200℃, Zone 3 200℃, Zone 4 210℃, Zone 5 210℃, Zone 6 220℃, Zone 7 220℃, Zone 8 220℃, and Zone 9 210℃. The side feed inlet is located in Zone 8, and the screw speed is 300 r / min.

[0066] Comparative Example 4:

[0067] Please provide a comparative example and test results without silicone light diffusing agent. Mix 98 parts of PP F800E, 0.3 parts of α-nucleating agent NA-21, 0.5 parts of β-nucleating agent TMB-5, 0.3 parts of antioxidant 1010, 0.4 parts of dispersant E525, and 0.5 parts of light stabilizer 1 evenly, and feed the mixture into a twin-screw extruder through the main feed port. After mixing, extrusion, stranding, and pelletizing, the polypropylene composite material is obtained.

[0068] The process temperatures of the twin-screw extruder from the feed inlet to the die are as follows: Zone 1 190℃, Zone 2 200℃, Zone 3 200℃, Zone 4 210℃, Zone 5 210℃, Zone 6 220℃, Zone 7 220℃, Zone 8 220℃, and Zone 9 210℃. The side feed inlet is located in Zone 8, and the screw speed is 300 r / min.

[0069] The polypropylene composite materials obtained in Examples 1-5 and Comparative Examples 1-3 were dried in an oven at 80°C for 2 hours, and then injection molded into 100*100*2.5mm thick color plates at 200°C. After conditioning at 23°C and 50%RH for 48 hours, the samples were tested. The transmittance and haze were tested according to ASTM D1003-13 standards using a haze / transmittance tester.

[0070] Table 1

[0071]

[0072] As can be seen from Table 1 above, the addition of both α-nucleating agent and β-nucleating agent in Examples 1-5 of the present invention can improve the transparency and haze of polypropylene materials; at the same time, the addition of organosilicon light diffusing agent in the present invention can further promote the improvement of the transparency and haze of polypropylene materials.

[0073] Although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

[0074] Therefore, the above description is only a preferred embodiment of this application and is not intended to limit the scope of this application; that is, all equivalent modifications made in accordance with the scope of the claims of this application shall be within the protection scope of the claims of this application.

Claims

1. A high-transparency, high-haze polypropylene material, characterized in that, It is prepared from the following components in parts by weight: 93.2-98 parts polypropylene, 1-4 parts light diffusing agent, 0.6-1.1 parts nucleating agent, 0.2-0.4 parts antioxidant, 0.2-0.6 parts dispersant, and 0.2-0.6 parts light stabilizer; The nucleating agent is composed of α-nucleating agent and β-nucleating agent in a mass ratio of 2-5:2-6.

2. The high-transparency, high-haze polypropylene material according to claim 1, characterized in that, The polypropylene is homopolymer polypropylene or random copolymer polypropylene.

3. The high-transparency, high-haze polypropylene material according to claim 1, characterized in that, The light diffusing agent is an organosilicon numerical spherical micronized light diffusing agent.

4. The high-transparency, high-haze polypropylene material according to claim 1, characterized in that, The α-nucleating agent is one of disorbitol and its derivatives, aromatic phosphate salts, and substituted benzoates; The β-nucleating agent is an aromatic amide compound.

5. The high-transparency, high-haze polypropylene material according to claim 1, characterized in that, The antioxidant is at least one of hindered phenolic antioxidants, phosphite antioxidants, and thioester antioxidants.

6. The high-transparency, high-haze polypropylene material according to claim 1, characterized in that, The dispersant is a silicone-based lubricant.

7. The high-transparency, high-haze polypropylene material according to claim 1, characterized in that, The light stabilizer is at least one selected from phenyl benzoate, 2-(2-hydroxy-5-methylphenyl)benzotriazole, 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-n-octyloxybenzophenone, 2-(2-hydroxy-3,5-di-tert-phenyl)-5-chlorobenzotriazole, and resorcinol monobenzoate.

8. A method for preparing a high-transparency, high-haze polypropylene material according to any one of claims 1-7, characterized in that, Includes the following steps: Weigh out polypropylene, light diffusing agent, nucleating agent, antioxidant, dispersant, and light stabilizer according to the mass ratio, mix them evenly, and feed them into a twin-screw extruder through the main feed port; after mixing, extrusion, stranding, and pelletizing, high-transparency and high-haze polypropylene material is obtained.

9. The preparation method according to claim 8, characterized in that, The temperature in each zone of the twin-screw extruder is 180-240℃; the screw speed is 200-600 r / min.

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