Polypropylene composite material with high flowability, high rigidity, high temperature resistance and excellent light diffusion performance as well as preparation method and application thereof

Abstract

The invention discloses a polypropylene composite material with high flowability, high rigidity, high temperature resistance and light diffusion performance as well as a preparation method and application thereof, the polypropylene composite material is prepared from the following component raw materials in parts by mass: 91.85-99.55 parts of polypropylene resin, 0.1-0.5 part of antioxidant, 0.1-0.5 part of nucleating agent and 0.1-0.5 part of light diffusant, and the component raw materials comprise 91.85-99.55 parts of polypropylene resin, 0.1-0.5 part of antioxidant, 0.1-0.5 part of nucleating agent and 0.1-0.5 part of light diffusant. 0.01 part to 0.05 part of an antioxidant; 0.04 to 0.1 part of a nucleating agent; 0.3 to 5 parts of a light diffusion agent; the light diffusion agent is an organic silicon resin spherical light diffusion agent. The high-flowability transparent polypropylene and the efficient light diffusion agent are selected to ensure that the prepared material has high light transmittance, high rigidity, high temperature resistance and light diffusion effect, the preparation process is simple, large-scale production of enterprises is facilitated, the cost is low, and the problem that a common light diffusion raw material is low in flowability is solved; and the LED lamp is suitable for being applied to the fields of LED lamps, light illumination and the like.

Description

Technical Field

[0001] The invention belongs to the technical field of polymer modified plastics, and relates to a polypropylene composite material with high fluidity, high rigidity, high temperature resistance and excellent light diffusion performance, and a preparation method and application thereof. Background Art

[0002] The introduction of LED lights is a revolution in the field of lighting. LED lights, also known as light-emitting diodes, can be used for lighting. They have low energy consumption and high brightness, but their light is strong and dazzling, making it difficult for people to look directly at them and unable to obtain a soft visual effect. The introduction of light diffusion products can solve these problems very well. Light diffusion materials refer to materials that can convert point light sources into line and surface light sources. Generally, light diffusion substances are added to the matrix. The light diffusion substances are spherical and evenly dispersed in the matrix to form a "sea-island structure". The matrix and the light diffusion substances have different refractive indexes, so the surface of the light diffusion substance can reflect light like a mirror, that is, after multiple light reflections, the matrix can achieve a light diffusion effect. Light diffusers are used in various lampshades to solve the problem of point light sources to surface light sources, with soft light and high brightness. The requirements for materials are mainly as follows: 1. High haze: light needs to avoid direct glare when passing through the material, and achieve a softer and more uniform illumination effect as much as possible; 2. High light transmittance: reduce energy consumption and improve the lighting effect of lamps; 3. High heat resistance: there will be conversion between light energy and heat energy, and the long-term use of the product will inevitably cause the temperature to rise, so it is necessary to ensure that the material will not deform or other defects when used for a long time under the working environment temperature, and the thermal deformation temperature of the material must be increased; 4. High weather resistance: the product is exposed to various light for a long time, and the material is easy to decompose, causing the product to turn yellow and affecting the service life, so light stabilizers and ultraviolet absorbers must be added. At present, light diffusion PC, PMMA and PS are commonly used, but the cost is relatively high.

[0003] Compared with PC and PMMA, polypropylene has lower cost and specific gravity. At the same time, some varieties have good light transmittance, chemical corrosion resistance, and convenient processing, making them suitable as light diffusion materials. At present, the main disadvantages of light diffusion PP on the market are as follows: 1. The haze and light transmittance cannot meet the requirements at the same time. After increasing the haze of the material, the light transmittance is significantly reduced, or after increasing the light transmittance of the material, the haze does not meet the requirements; 2. The rigidity cannot meet the requirements, and the parts are easily deformed due to gravity; 3. The heat resistance cannot meet the requirements, and the product softens and deforms after a period of use; 4. The processing fluidity cannot meet the requirements, and the production of large thin-walled products is difficult. Therefore, it is necessary to make further improvements. Summary of the invention

[0004] In order to overcome the shortcomings of the prior art, the object of the present invention is to provide a polypropylene composite material with high flowability, high rigidity, high temperature resistance and light diffusion performance and a preparation method thereof. The preparation method of the polypropylene composite material with high flowability, high rigidity, high temperature resistance and light diffusion performance provided by the present invention is relatively simple, has a low production cost, and is easy to mass produce.

[0005] On one hand, the present invention provides a polypropylene composite material, which is prepared from component raw materials containing a mass ratio, wherein the component raw materials include: 91.85 parts to 99.55 parts of polypropylene resin; 0.01 parts to 0.05 parts of antioxidant; 0.04 parts to 0.1 parts of nucleating agent; 0.3 parts to 5 parts of light diffuser; the light diffuser is a silicone resin spherical light diffuser.

[0006] The present invention ensures that all aspects of the material performance are significantly improved and the requirements for the manufactured parts are met through the selection of raw materials, various additives and the synergistic addition between the various components.

[0007] Optionally, the nucleating agent is HPN-900ei (a mixture of hydroxymagnesium p-tert-butylbenzoate and aluminum carboxylate). The polypropylene selected is transparent random copolymer polypropylene or homopolymer polypropylene. The material itself has good transparency. On this basis, the addition of the nucleating agent HPN-900ei can further refine the crystals of the crystallized part, thereby further increasing the transparency of the material, greatly improving the rigidity of the product, and increasing the heat resistance.

[0008] Optionally, the antioxidant may be any antioxidant deemed necessary by a person skilled in the art, preferably at least one of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate (antioxidant 1010), tris[2,4-di-tert-butylphenyl]phosphite (antioxidant 168), octadecyl thiodipropionate (antioxidant DSTP), and n-octadecyl β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate (antioxidant 1076).

[0009] Optionally, the light diffuser is a silicone resin spherical light diffuser. The light diffuser preferably has a light refractive index of 1.40 to 1.43. The light diffuser is a silicone light diffuser, which is a polymer microsphere connected by silicon oxygen bonds and has a three-dimensional structure. When added to polypropylene, it will be evenly dispersed in the matrix as a fine transparent glass sphere. Through the difference in refractive index with different substrates, the light source is refracted in a penetrating manner, changing the path of light, achieving the purpose of uniform light and light transmission, which not only greatly improves the haze value of the material, but also does not affect the light transmittance of the material.

[0010] Optionally, the melt index of the polypropylene resin is 20-100 g / 10 min. The polypropylene selected is high-fluidity polypropylene, which can meet the production needs of large, complex, and thin-walled products.

[0011] Optionally, the polypropylene resin is homopolymer polypropylene or random copolymer polypropylene. Optionally, the homopolymer polypropylene has a crystallinity of more than 70% and an isotacticity of more than 97.5%.

[0012] Optionally, the comonomer of the random copolymer polypropylene is ethylene and / or butene, and the mass content of the repeating units of the ethylene and / or butene monomers is 0.5-5%.

[0013] The component raw materials also contain an auxiliary agent; the auxiliary agent is selected from at least one of an odor adsorbent and a lipid lubricant; preferably, the mass fraction of the auxiliary agent is 0.1 to 3 parts. The auxiliary agent of the present invention is mainly a combination of one or more of various processing aids, odor adsorbents and various lipid lubricants that are considered necessary by those skilled in the art.

[0014] On the other hand, the present invention also provides a method for preparing any of the above-mentioned polypropylene composite materials, comprising: obtaining component raw materials containing polypropylene resin, antioxidant, nucleating agent and light diffusing agent, mixing the component raw materials to obtain a mixture; and melt-extruding, cooling and granulating the mixture to obtain the polypropylene composite material.

[0015] As a specific implementation, the method includes the following steps:

[0016] (1) The above-mentioned raw materials are weighed and mixed according to the mass ratio, and preferably the components such as polypropylene, nucleating agent, light diffusing agent, antioxidant and auxiliary agent are placed in a high-speed mixer and mixed evenly. The mixing conditions include: low speed 0 to 600 r / min, preferably 400 to 600 r / min, mixing for 1 to 3 minutes, and high speed 800 to 2000 r / min mixing for 1 to 2 minutes.

[0017] (2) The mixed material is added into a twin-screw extruder from a main feed port, and after melt extrusion, drawing, cooling, and granulation, the mixed material is subjected to a drying treatment to prepare a low-gloss, high-rigidity, high-impact, and low-shrinkage polypropylene composite material for automobiles, wherein the speed of the extruder screw is 60 to 600 r / min, and the temperature of the extruder from feeding to the die is set to: 190°C to 200°C, 195°C to 205°C, 200°C to 210°C, 205°C to 215°C, 205 to 215°C, 200°C to 210°C, 195°C to 205°C, 190°C to 200°C, and 185°C to 195°C.

[0018] In another aspect, the present invention provides use of the polypropylene composite material as a lighting material cover.

[0019] Optionally, the lighting material is an LED lamp.

[0020] The invention uses high-fluidity transparent polypropylene as the base material to ensure the transparency of the product, and at the same time uses a nucleating agent to modify it to ensure that the manufactured material has the effects of high light transmittance, high rigidity and high temperature resistance; the invention uses a high-efficiency light diffusing agent, and the light diffusing polypropylene manufactured thereby has good light transmittance and light diffusing effect; the invention has a simple preparation process, is conducive to large-scale production by enterprises, and has a cost much lower than that of light diffusing PC or light diffusing PMA, and at the same time solves the problems of low fluidity, insufficient rigidity and insufficient heat resistance of ordinary light diffusing raw materials, and is suitable for applications in the fields of LED lamps, lighting, etc. DETAILED DESCRIPTION

[0021] The present invention is further described in detail below in conjunction with the embodiments. The scope of the present invention is not limited by these embodiments, and the scope of the present invention is set forth in the claims.

[0022] In the composite material formula of the embodiment and the comparative example, the polypropylene used is homopolypropylene produced by Sinopec Tianjin Branch, with a trade name of PPH-M70, and a melt flow rate of 70g / 10min (test conditions: 230°C, 2.16kg); the nucleating agent used is Milliken's Hyperform HPN-900ei; the antioxidant is 1010 (tetrakis[B-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid] tetraethylene glycol ester / tris[2,4-di-tert-butylphenyl] phosphite (antioxidant 168) / DSTP (octadecyl thiodipropionate) in a mass ratio of 1:2:1 compound antioxidant with a refractive index of 1.43; the light diffuser used is a commercially available high-efficiency silicone resin light diffuser HY-690A from MSE of the United States; the additives used include various antistatic agents, flame retardants, various types or fatty acid lubricants, etc.

[0023] The present invention is described in detail below with reference to specific examples. Unless otherwise specified, all components in the examples are expressed in mass percentages, and the contents of the components in the examples and comparative examples of the present invention are shown in Table 1. Among them, the compounded antioxidant B215 is compounded by antioxidant 1010 (phenols) and auxiliary antioxidant 168 (phosphite) in a mass ratio of 1:2.

[0024] Example 1

[0025] Before use, weigh the component raw materials according to the weight ratio of Table 1, and mix the component raw materials such as polypropylene, nucleating agent, light diffuser, antioxidant additive in a high-speed mixer. The mixing conditions are: low speed 500r / min, mixing for 2 minutes, high speed 2000r / min mixing for 1 minute; add the above mixed raw materials from the main feeding port to the twin-screw extruder, melt extrusion, drawing, cooling, granulation, and then bake the material to prepare a polypropylene composite material with high flow, high rigidity, high temperature resistance and light diffusion performance, wherein the speed of the extruder screw is 600r / min, and the temperature of the extruder from feeding to the die is set to: 200℃, 205℃, 210℃, 215℃, 215℃, 210℃, 205℃, 200℃, 190℃.

[0026] Comparative Example 1

[0027] The difference between Comparative Example 1 and Example 1 is that the component raw materials do not contain light diffusers and nucleating agents. The contents of each component are shown in Table 1.

[0028] Comparative Example 2

[0029] The difference between Comparative Example 2 and Example 1 is that the component raw materials do not contain a nucleating agent, and the content of each component is shown in Table 1.

[0030] Comparative Example 3

[0031] The difference between Comparative Example 3 and Example 1 is that the component raw materials do not contain light diffusing agent, and the content of each component is shown in Table 1.

[0032] Comparative Example 4

[0033] The difference between Comparative Example 4 and Example 1 is that instead of adding a silicone resin type light diffuser, an inorganic light diffuser (nano barium sulfate) is added to the component raw materials. The content of each component is shown in Table 1.

[0034] Comparative Example 5

[0035] The only difference between Comparative Example 5 and Example 1 is that HPN-900ei is not added to the component raw materials, but a different nucleating agent - NAA325 (nucleating agent produced by Guangzhou Chenghe) is added. The specific content of each component is shown in Table 1.

[0036] Table 1 Content of each main component in the embodiments and comparative examples (mass percentage)

[0037]

[0038] Table 2 Material performance test results in the embodiments and comparative examples

[0039]

[0040] Basic mechanical properties test: flexural modulus is tested according to the national standard GB / T 9341-2008; haze and light transmittance are tested according to the national standard GB / T 2410-2008; heat deformation temperature is tested according to the national standard GB / T1634.2-2004.

[0041] From the test data results of the embodiments and comparative examples in Table 2, it can be found that from Examples 1-8 and Comparative Examples 1-5, it can be found that the light transmittance of the polypropylene composite material system prepared by the technical solution of adding a silicone resin type light diffusing agent in the present invention can be increased from 85% of the comparative example to about 91%, and the haze can be increased from the original 48% to about 93%; from the test results of the above embodiments 1-8 and Comparative Example 1, it can be found that the bending modulus of the polypropylene composite material system prepared by the technical solution of adding a nucleating agent in the present invention is increased from 1520MPa of the comparative example to 2326MPa; and the heat deformation temperature is increased from the original 80.3°C to 110.6°C.

[0042] In summary, the polypropylene composite material prepared by introducing silicone resin type light diffuser and nucleating agent into the polypropylene composite material system has high rigidity, high fluidity, good heat resistance, excellent light diffusion effect, and can meet the performance requirements of LED lamps, home appliances and other fields.

[0043] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. The present invention may be subject to various changes and improvements without departing from the spirit and scope of the present invention. These changes and improvements fall within the scope of the present invention. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A polypropylene composite material, characterized in that: It is prepared from component raw materials containing polypropylene resin, antioxidant, nucleating agent and light diffusing agent, and the mass fractions of the component raw materials are: 91.85 to 99.55 parts of polypropylene resin; Antioxidant 0.01 to 0.05 parts; Nucleating agent 0.04 to 0.1 parts; Light diffusing agent 0.3 to 5 parts; The light diffuser is a silicone resin spherical light diffuser.

2. The polypropylene composite material according to claim 1, characterized in that: The nucleating agent is HPN-900ei; And / or, the antioxidant is selected from at least one of antioxidant 1010, antioxidant 168, antioxidant DSTP, and antioxidant 1076.

3. The polypropylene composite material according to claim 1 or 2, characterized in that: The light refractive index of the light diffusing agent is 1.40 to 1.43; And / or, the melt index of the polypropylene resin is 20 to 100 g / 10 min.

4. The polypropylene composite material according to claim 1, 2 or 3, characterized in that: The polypropylene resin is homopolymer polypropylene or random copolymer polypropylene.

5. The polypropylene composite material according to claim 4, characterized in that: The homopolymer polypropylene has a crystallinity of more than 70% and an isotacticity of more than 97.5%; And / or, the comonomer of the random copolymer polypropylene is ethylene and / or butene, and the mass content of the repeating units of ethylene and / or butene monomers is 0.5-5%.

6. The polypropylene composite material according to any one of claims 1 to 5, characterized in that: The component raw materials also contain auxiliary agents; The auxiliary agent is selected from at least one of an odor adsorbent and a lipid lubricant; And / or, the mass fraction of the auxiliary agent is 0.1 to 3 parts.

7. The method for preparing the polypropylene composite material according to any one of claims 1 to 6, characterized in that: The preparation method comprises: obtaining component raw materials containing polypropylene resin, antioxidant, nucleating agent and light diffusing agent, mixing the component raw materials to obtain a mixture; and subjecting the mixture to melt extrusion, cooling and granulation to obtain the polypropylene composite material.

8. The preparation method according to claim 7, characterized in that: The temperature of the melt extrusion is 185°C to 215°C.

9. Use of the polypropylene composite material according to any one of claims 1 to 6 or the polypropylene composite material obtained by the preparation method according to claim 7 or 8 as a lighting material cover.

10. The use according to claim 9, characterized in that: The lighting material is an LED lamp.

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