High-light-transmittance polypropylene composition with controllable light-transmittance color rendering and uniformity and preparation method of high-light-transmittance polypropylene composition

Abstract

The invention discloses a high-light-transmittance polypropylene composition with controllable light-transmittance color rendering and uniformity and a preparation method thereof. The high-light-transmittance polypropylene composition comprises the following raw materials in parts by weight: 50-90 parts of PP resin, 0-30 parts of reinforcing filler, 0-30 parts of a flexibilizer, 0-3 parts of a haze regulator, 0.05-0.5 part of a color regulator and 0-4 parts of an auxiliary agent, the PP resin is rigid-tough balanced resin, and the PP resin is a square plate with the thickness of 3.2 mm, and the light transmittance of the square plate is not lower than 65%. A conventional polypropylene talcum powder composite material system has low light transmission performance, the crystal whiskers and the hollow glass beads are added, the excellent light transmission effect of the material is guaranteed, meanwhile, the micro-nano coloring agent toner with the corresponding color is added, the light transmission color rendering property is controllable while light transmission is achieved, and the light transmission effect is good. And various light-transmitting tones can be displayed according to customer requirements. And the material has a great application prospect in automobile light-transmitting parts with high requirements on light-transmitting color rendering and uniformity of the material.

Description

Technical Field

[0001] The invention relates to a polypropylene composite material and a preparation method thereof. The obtained material has excellent light transmittance, and the light transmittance color rendering is controllable while transmitting light. Various light transmittance tones can be displayed according to customer needs, and the distribution is uniform. The invention belongs to the field of polymer material processing and modification. Background Art

[0002] As a cost-effective general-purpose plastic, polypropylene has excellent mechanical properties after blending and modification, and its molding process is relatively simple. Therefore, it is widely used in products such as home appliances and automobiles.

[0003] The exterior design of new energy vehicles shows more innovation and personalization in terms of lighting. Traditional fuel vehicles mainly focus on the design and function of headlight components, while new energy vehicles pay more attention to the overall sense of technology and future, and various details including lighting are given more creativity and functionality.

[0004] In terms of lighting design, in addition to the improvement of headlight components, the bumper has also become an important design element. By designing patterns or patterns on the bumper with a certain light transmittance and placing a backlight component on its back, the bumper can play an unprecedented decorative role. This design can not only increase the appearance of the vehicle, but also improve the safety and visibility of night driving.

[0005] Traditional polypropylene interior and exterior materials for automobiles are usually made by blending raw materials such as polypropylene, elastomers, and talc through processing equipment such as twin-screw extruders. However, this traditional solution will cause greater light reflection, light absorption, and light scattering problems. Therefore, the light transmittance of traditional modified PP materials is not high.

[0006] Common translucent materials often only focus on their transmittance to light, and rarely pay attention to the change in color after the light passes through the material. Usually, the light bulbs on cars are LED bulbs. There are differences in the cost of bulbs of different colors. The luminescent materials used in white light LED bulbs are usually blue light LED chips plus fluorescent powder, which are relatively low in cost. Colored LED bulbs require the use of different luminescent materials, such as red, green, and blue primary color LED chips, which will be relatively expensive, and directly using lampshades with colors can significantly reduce costs. And the haze and the concentration of color powder can be adjusted to make its light transmittance and color rendering controllable, and various light transmittance tones can be displayed according to customer needs. In addition, by adding a small amount of additives and improving the extrusion process, compared with the conventional translucent polypropylene materials currently on the market, the light transmittance uniformity is improved to a greater extent while ensuring high light transmittance.

[0007] Therefore, there is still a need in the art to develop a high-light-transmittance polypropylene composite material with simple preparation, low cost, controllable light transmittance and color rendering and uniformity, and a preparation method thereof. Summary of the invention

[0008] The object of the present invention is to provide a high-light-transmittance polypropylene composite material which is not available on the market and has controllable light-transmittance color rendering and uniformity, and a preparation method thereof.

[0009] To achieve the above object, the technical solution adopted by the present invention is:

[0010] A high-light-transmittance polypropylene composite material with controllable light-transmittance color rendering and uniformity comprises the following raw materials in parts by weight: 50-90 parts of PP resin, 0-30 parts of reinforcing filler, 0-30 parts of toughening agent, 0-3 parts of haze regulator, 0.05-0.5 parts of color regulator and 0-4 parts of auxiliary agent; the PP resin is a rigid-toughness balanced resin, and the light transmittance of a square plate with a thickness of 3.2 mm is not less than 65%; the light transmittance is tested according to GB / T 2410 standard.

[0011] The PP resin is a PP resin whose light transmittance of a square plate with a thickness of 3.2 mm is not less than 65% and whose bending modulus is not less than 1600 MPa.

[0012] The reinforcing filler is an inorganic whisker.

[0013] The filler is an inorganic whisker with an aspect ratio higher than 20:1 and a diameter lower than 2 μm. Since talcum powder is used as a two-dimensional filler, during the injection molding process, due to the orientation effect of the shear force field, it is easy to cause a large amount of talcum powder to be arranged in parallel with the injection molding square plate, and the reflection of light is very obvious, thereby causing a relatively large loss to the light transmittance of the product; the one-dimensional filler represented by whiskers has a weaker reflection effect on light, and causes less loss to the light transmittance of the product. In addition, a one-dimensional filler with a higher aspect ratio is selected. Because of its higher aspect ratio, the rigidity enhancement effect is significantly better than talcum powder. Only half of the filler dosage needs to be added to achieve similar mechanical properties, and the material density is significantly reduced. Therefore, the use of a one-dimensional filler with a high aspect ratio for rigidity enhancement can maintain the high light transmittance of the material while increasing rigidity.

[0014] The toughening agent is a styrene elastomer. Polyolefin elastomers have a certain difference in refractive index with PP, which causes a relatively large loss in the light transmittance of the product; the refractive index difference between styrene elastomers and PP is small, which causes a relatively small loss in the light transmittance of the product. Therefore, the use of styrene elastomers for toughening can effectively toughen and maintain the high light transmittance of the material.

[0015] The haze regulator is a hollow transparent microsphere.

[0016] The color regulator is a micro-nano colorant toner of a corresponding color.

[0017] The auxiliary agent is at least one of an antioxidant, a light stabilizer, a lubricant, and a hyperdispersant. The auxiliary agent in the present application can be specifically selected by those skilled in the art according to actual conditions.

[0018] At the same time, the present invention also provides a method for preparing the highly light-transmitting polypropylene composite material with controllable light-transmitting color rendering and uniformity, the steps of which are:

[0019] Add all ingredients to a high mixer and mix them evenly, then add the mixed raw materials to a twin-screw extruder for melt extrusion, granulation, drying, cooling, and packaging to obtain the high-transmittance polypropylene composition with controllable light transmittance and uniformity; wherein, the whiskers and hollow glass microspheres are fed by the side to prevent the whiskers and hollow glass microspheres from being sheared and damaged by the twin screws, and the other components are fed by the main feeding method. In particular, a reverse conveying module is added to the conventional screw combination. This screw combination can prevent the whiskers and hollow glass microspheres from being sheared and damaged by the twin screws, retain the whisker length to the maximum extent, ensure the excellent mechanical properties of the composite material, and make the materials mixed evenly in the extruder, ensuring the uniformity of the light transmittance of the composite material. The temperature of the twin-screw extruder is 170℃, 200℃, 200℃, 210℃, 210℃, 205℃, 205℃, 205℃, 200℃, and 200℃ from the feeding section to the die.

[0020] Furthermore, the present invention introduces a reverse shear module and weakens the shearing effect of the screw by adjusting the shear strength of the reverse shear module and the shear block of the feeding screw. The present invention adopts a combination of 30°, 45°, 60°, and 90° shear blocks, and compares the effects of different shear strengths on material properties to explore the appropriate shear strength.

[0021] The maintenance of high light transmittance and haze and high toner dispersion is achieved by changing the arrangement and combination of the extrusion screws. The present invention achieves the purpose of controlling the whiskers and glass microbeads to be fully melted and mixed with the PP resin by adjusting the shear strength of the shear and conveying section screws and the introduced reverse shear module in the twin-screw extruder, while reducing the two components in the composite material from being damaged by the screw shear. The specific combination is as follows:

[0022]

[0023]

[0024] The traditional shear module has a great damage to the hollow glass microspheres, and the retention degree of this component has a great influence on the light transmission performance and haze of this composite material. After comparison, it was found that the traditional shear module has a great damage to the glass microspheres, and the integrity of the hollow glass microspheres is only 50%, while after passing through the reverse transmission module, the integrity is as high as more than 70%. For whiskers, maintaining a high aspect ratio is the key to improving the mechanical properties of composite materials. The traditional shear module is easy to cause great damage to the whiskers due to its strong shearing ability, while the use of the directional transmission module will retain whiskers with a larger aspect ratio to the greatest extent.

[0025]

[0026] Compared with the prior art, the technical solution of the present invention has the following technical advantages:

[0027] (1) The light transmittance and color rendering properties are controllable, and various light transmittance tones can be displayed according to customer needs.

[0028] (2) By precisely controlling the material formula and preparation process, the components inside the material can be evenly distributed, ensuring that the light transmittance of the material as a whole is consistent while the light transmittance of each part remains consistent, thereby improving the stability and controllability of the material.

[0029] (3) The production process is simple and the formula cost is low. It has great application prospects in automotive translucent parts (such as bumpers, ambient lights, etc.) that have high requirements for material transmittance, color rendering and uniformity. DETAILED DESCRIPTION

[0030] Below in conjunction with specific embodiment, further elaborate content of the present invention.It should be emphasized that these embodiments are only used for further explanation of the present invention, and can not be interpreted as limiting the scope of protection of the present invention.In addition, it should be understood that after reading the content described in the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope limited by the appended claims of the application.

[0031] The main representative materials used in the embodiments and comparative examples are as follows:

[0032] PP-1: Brand EP548R, CNOOC Shell, 3.2mm square plate transmittance 65%, flexural modulus 1600MPa.

[0033] Styrene toughening agent: styrene-ethylene-butylene-styrene block copolymer, styrene content about 13%;

[0034] Whiskers: a commercially available product, with a diameter of about 1 μm and an average aspect ratio of about 25:1;

[0035] Hollow transparent microspheres: a commercially available product, borosilicate, average particle size 20 μm;

[0036] Masterbatch: a commercially available product;

[0037] The preparation method of the high light transmittance polypropylene composite material with controllable light transmittance, color rendering and uniformity is as follows:

[0038] Add all ingredients into a high-speed mixer and mix them evenly, then add the mixed raw materials into a twin-screw extruder for melt extrusion, granulation, drying, cooling, and packaging to obtain the high-transmittance polypropylene composition with controllable light transmittance, color rendering and uniformity; wherein, the whiskers and hollow glass microbeads are fed from the side, and a reverse conveying module is added at the same time, which not only prevents the whiskers and hollow glass microbeads from being sheared and damaged by the twin screws, but also makes the materials fully mixed evenly, so that there is no obvious accumulation of color powder on the appearance of the product, and the other components are fed in the main way. The temperature of the twin-screw extruder from the feeding section to the head is 170℃, 200℃, 200℃, 210℃, 210℃, 205℃, 205℃, 200℃, 200℃.

[0039] The screw / reverse conveying module combinations 1 to 8 are as shown in the product instructions.

[0040] Example 1

[0041] 63 parts of PP, antioxidant (antioxidant 1010, 168 0.2 parts respectively), 20 parts of toughening agent, 0.05 parts of ultramarine masterbatch and other additives were mixed evenly and added to the twin-screw extruder from the main feed port, 15 parts of whiskers were fed from the side feed port at a speed of 100rpm, and the combination of screw / reverse shear module 5-8 was extruded and granulated, and injection molded to prepare standard specimens. Among them, the extrusion melt blending temperature was 230℃, and the extrusion vacuum was opened and the vacuum degree was maintained at -0.08MPa.

[0042] Example 2

[0043] 63 parts of PP, antioxidant (antioxidant 1010, 168 0.2 parts respectively), 20 parts of toughening agent, 0.05 parts of ultramarine masterbatch and other additives were mixed evenly and added to the twin-screw extruder from the main feed port, 15 parts of whiskers and 1 part of hollow glass microspheres were fed from the side feed port at a speed of 100rpm, and the combination of screw / reverse shear module 5-8 was extruded for granulation and injection molding to prepare standard specimens. Among them, the extrusion melt blending temperature was 230℃, and the extrusion vacuum was opened and the vacuum degree was maintained at -0.08MPa.

[0044] Example 3

[0045] 63 parts of PP, antioxidant (antioxidant 1010, 168 0.2 parts respectively), 20 parts of toughening agent, 0.05 parts of ultramarine masterbatch and other additives were mixed evenly and added to the twin-screw extruder from the main feed port, 15 parts of whiskers and 2 parts of hollow glass microspheres were fed from the side feed port at a speed of 100rpm, and the combination of screw / reverse shear module 5-8 was extruded for granulation and injection molding to prepare standard specimens. Among them, the extrusion melt blending temperature was 230℃, and the extrusion vacuum was opened and the vacuum degree was maintained at -0.08MPa.

[0046] Example 4

[0047] 63 parts of PP, antioxidant (antioxidant 1010, 168 0.2 parts respectively), 20 parts of toughening agent, 0.05 parts of ultramarine masterbatch and other additives were mixed evenly and added to the twin-screw extruder from the main feed port, 15 parts of whiskers and 3 parts of hollow glass microspheres were fed from the side feed port at a speed of 100rpm, and the combination of screw / reverse shear module 5-8 was extruded for granulation and injection molding to prepare standard specimens. Among them, the extrusion melt blending temperature was 230℃, and the extrusion vacuum was opened and the vacuum degree was maintained at -0.08MPa.

[0048] Example 5

[0049] 63 parts of PP, antioxidant (antioxidant 1010, 168 0.2 parts respectively), 20 parts of toughening agent, 0.25 parts of ultramarine masterbatch and other additives were mixed evenly and added to the twin-screw extruder from the main feed port, 15 parts of whiskers and 3 parts of hollow glass microspheres were fed from the side feed port at a speed of 100rpm, and the combination of screw / reverse shear module 5-8 was extruded for granulation and injection molding to prepare standard specimens. Among them, the extrusion melt blending temperature was 230℃, and the extrusion vacuum was opened and the vacuum degree was maintained at -0.08MPa.

[0050] Example 6

[0051] 63 parts of PP, antioxidant (antioxidant 1010, 168 0.2 parts respectively), 20 parts of toughening agent, 0.5 parts of ultramarine masterbatch and other additives were mixed evenly and added to the twin-screw extruder from the main feed port, 15 parts of whiskers and 3 parts of hollow glass microspheres were fed from the side feed port at a speed of 100rpm, and the combination of screw / reverse shear module 5-8 was extruded for granulation and injection molding to prepare standard specimens. Among them, the extrusion melt blending temperature was 230℃, and the extrusion vacuum was opened and the vacuum degree was maintained at -0.08MPa.

[0052] Comparative Example 1

[0053] 63 parts of PP, antioxidant (antioxidant 1010, 168 0.2 parts respectively), 20 parts of toughening agent, 0.05 parts of ultramarine masterbatch and other additives were mixed evenly and added to the twin-screw extruder from the main feed port, 15 parts of whiskers were fed from the side feed port at a speed of 100rpm, and the combination of screw / reverse shear module 1 to 4 was extruded and granulated, and injection molded to prepare standard specimens. Among them, the extrusion melt blending temperature was 230°C, and the extrusion vacuum was opened and the vacuum degree was maintained at -0.08MPa.

[0054] Comparative Example 2

[0055] 63 parts of PP, antioxidant (antioxidant 1010, 168 0.2 parts respectively), 20 parts of toughening agent, 0.05 parts of ultramarine masterbatch and other additives were mixed evenly and added to the twin-screw extruder from the main feed port, 15 parts of whiskers and 1 part of hollow glass microspheres were fed from the side feed port at a speed of 100rpm, and the combination of screw / reverse shear module 1 to 4 was extruded and granulated, and injection molded to prepare standard specimens. Among them, the extrusion melt blending temperature was 230°C, and the extrusion vacuum was opened and the vacuum degree was maintained at -0.08MPa.

[0056] Comparative Example 3

[0057] 63 parts of PP, antioxidant (antioxidant 1010, 168 0.2 parts respectively), 20 parts of toughening agent, 0.05 parts of ultramarine masterbatch and other additives were mixed evenly and added to the twin-screw extruder from the main feed port, 15 parts of whiskers and 2 parts of hollow glass microspheres were fed from the side feed port at a speed of 100rpm, and the combination of screw / reverse shear module 1 to 4 was extruded and granulated, and injection molded to prepare standard specimens. Among them, the extrusion melt blending temperature was 230°C, and the extrusion vacuum was opened and the vacuum degree was maintained at -0.08MPa.

[0058] Comparative Example 4

[0059] 63 parts of PP, antioxidant (antioxidant 1010, 168 0.2 parts respectively), 20 parts of toughening agent, 0.05 parts of ultramarine masterbatch and other additives were mixed evenly and added to the twin-screw extruder from the main feed port, 15 parts of whiskers and 3 parts of hollow glass microspheres were fed from the side feed port at a speed of 100rpm, and the combination of screw / reverse shear module 1 to 4 was extruded and granulated, and injection molded to prepare standard specimens. Among them, the extrusion melt blending temperature was 230℃, and the extrusion vacuum was opened and the vacuum degree was maintained at -0.08MPa.

[0060] Comparative Example 5

[0061] 63 parts of PP, antioxidant (antioxidant 1010, 168 0.2 parts respectively), 20 parts of toughening agent, 0.25 parts of ultramarine masterbatch and other additives were mixed evenly and added to the twin-screw extruder from the main feed port, 15 parts of whiskers and 3 parts of hollow glass microspheres were fed from the side feed port at a speed of 100rpm, and the combination of screw / reverse shear module 1 to 4 was extruded and granulated, and injection molded to prepare standard specimens. Among them, the extrusion melt blending temperature was 230°C, and the extrusion vacuum was opened and the vacuum degree was maintained at -0.08MPa.

[0062] Comparative Example 6

[0063] 63 parts of PP, antioxidant (antioxidant 1010, 168 0.2 parts respectively), 20 parts of toughening agent, 0.5 parts of ultramarine masterbatch and other additives were mixed evenly and added to the twin-screw extruder from the main feed port, 15 parts of whiskers and 3 parts of hollow glass microspheres were fed from the side feed port at a speed of 100rpm, and the combination of screw / reverse shear module 1 to 4 was extruded and granulated, and injection molded to prepare standard specimens. Among them, the extrusion melt blending temperature was 230℃, and the extrusion vacuum was opened and the vacuum degree was maintained at -0.08MPa.

[0064] Performance Testing

[0065] In the above embodiments and comparative examples, the density is tested according to ISO 1183-1 standard; the tensile performance is tested according to ISO527-2 standard, and the tensile speed is 50mm / min; the flexural strength and flexural modulus are tested according to ISO 178 standard, and the bending speed is 2mm / min; the cantilever beam notched impact is tested according to ISO 180 standard; the color uniformity is visually judged; the light transmittance is tested according to GB / T 2410 standard: the method A haze meter method is selected to test the light transmittance of the injection molded square plate (size 150mm*100mm*3.2mm) of each sample. The number of color powder accumulation, the injection molded square plate (size 150mm*100mm*3.2mm) is observed under the light source.

[0066] Table 1 Performance evaluation of materials prepared in Examples 1-6 and Comparative Examples 1-6

[0067]

[0068]

[0069] Table 1 shows the performance evaluation results of the materials prepared in Examples 1-6 and Comparative Examples 1-6. The following conclusions are drawn from the analysis results: By analyzing the material properties of the screw / reverse shear module combinations 1-4 and 5-8 in the Examples and Comparative Examples, it is found that the introduction of the reverse conveying module helps to increase the integrity of the hollow glass microspheres, improve the light transmittance and haze of the material, and at the same time improve the dispersion and bonding problem between the masterbatch / polypropylene matrix, and the amount of color powder accumulation is significantly reduced without having a significant impact on the mechanical properties of the material.

[0070] From the performance data in Table 1, it can be seen that Examples 1 to 6 and Comparative Examples 1 to 6 have excellent mechanical properties. By adding whiskers and hollow glass microspheres, the excellent light transmission effect of the material is guaranteed. At the same time, styrene-based toughening agents are added for toughening, so that the composite material has good impact resistance. The corresponding color masterbatch is added, and the light transmission and color rendering are controllable while transmitting light, and various light transmission tones can be displayed according to customer needs. The production process of the patent of the present invention is simple. By adding a reverse conveying module, the materials are fully mixed and uniformly mixed, so that there is no obvious accumulation of color powder on the appearance of the product. It has great application prospects in automotive light-transmitting parts (such as bumpers, atmosphere lights, etc.) that have high requirements on the light transmission and color rendering and uniformity of the material.

[0071] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit the protection scope of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the essence and scope of the technical solution of the present invention.

Claims

1. A highly light-transmitting polypropylene composition with controllable light-transmitting color rendering and uniformity, characterized in that: The invention comprises the following raw materials in parts by weight: 50-90 parts of PP resin, 0-30 parts of reinforcing filler, 0-30 parts of toughening agent, 0-3 parts of haze regulator, 0.05-0.5 parts of color regulator and 0-4 parts of auxiliary agent; the PP resin is a rigid-toughness balanced resin, and the light transmittance of a square plate with a thickness of 3.2 mm is not less than 65%; the light transmittance is tested according to GB / T 2410 standard.

2. A highly light-transmitting polypropylene composition with controllable light-transmitting color rendering and uniformity according to claim 1, characterized in that: The PP resin is a PP resin whose light transmittance of a square plate with a thickness of 3.2 mm is not less than 65% and whose bending modulus is not less than 2000 MPa.

3. A highly light-transmitting polypropylene composition with controllable light-transmitting color rendering and uniformity according to claim 1, characterized in that: The reinforcing filler is an inorganic whisker.

4. A highly light-transmitting polypropylene composition with controllable light-transmitting color rendering and uniformity according to claim 1, characterized in that: The toughening agent is a styrene elastomer.

5. The high light transmittance polypropylene composition with controllable light transmittance color rendering and uniformity according to claim 1, characterized in that: The haze regulator is a hollow transparent microsphere.

6. The highly light-transmitting polypropylene composition with controllable light-transmitting color rendering and uniformity according to claim 1, characterized in that: The color regulator is a micro-nano colorant masterbatch of a corresponding color.

7. The high light transmittance polypropylene composition with controllable light transmittance color rendering and uniformity according to claim 1, characterized in that: The auxiliary agent is at least one of an antioxidant, a light stabilizer, a lubricant, and a hyperdispersant.

8. The highly light-transmitting polypropylene composition with controllable light-transmitting color rendering and uniformity and the preparation method thereof according to any one of claims 1 to 7, characterized in that: The method is: The components are added into a high-speed mixer and mixed evenly, and then the mixed raw materials are added into a twin-screw extruder for melt extrusion, granulation, drying, cooling and packaging to obtain the high-light-transmittance polypropylene composition with controllable light transmittance, color rendering and uniformity; wherein the whiskers and hollow glass microbeads are fed from the side, and a reverse conveying module is added to prevent the whiskers and hollow glass microbeads from being sheared and damaged by the twin-screw, and to fully mix the materials evenly, so that there is no obvious accumulation of toner on the appearance of the product, and the other components are fed mainly; the temperature of the twin-screw extruder is 170°C, 200°C, 200°C, 210°C, 210°C, 205°C, 205°C, 200°C, and 200°C from the feeding section to the die.

9. The method for preparing a highly light-transmitting polypropylene composition with controllable light-transmitting color rendering and uniformity as claimed in claim 8, characterized in that: Add all ingredients into a high mixer and mix at 250-350 rpm for 5-8 minutes.

10. The method for preparing a highly light-transmitting polypropylene composition with controllable light-transmitting color rendering and uniformity according to claim 8, characterized in that: Polypropylene raw materials, color powder and related antioxidant additives are fed into the twin-screw extruder through the main feeding port, and whiskers and hollow glass microspheres are directly fed into the extruder through the side feeding port.

11. The method for preparing a highly light-transmitting polypropylene composition with controllable light-transmitting color rendering and uniformity according to claim 8, characterized in that: The invention appropriately adjusts the shearing action of the screw and introduces a set of reverse shearing modules to increase the retention length of the whiskers in the modified material and the integrity of the hollow glass microspheres, while enabling the molten polypropylene resin to be fully and evenly mixed with the whiskers and the hollow glass microspheres.

12. The method for preparing a highly light-transmitting polypropylene composition with controllable light-transmitting color rendering and uniformity according to claim 8, characterized in that: The present invention adopts 30°, 45°, 60° and 90° shear block combinations respectively.

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