A kind of polypropylene composite material and preparation method thereof

Abstract

The invention provides a low-dielectric polypropylene composite material, by adding a certain amount of nitrogen adsorption specific surface area ≥ 300m 2 / g of carbon black can reduce the amount of carbon black added, thereby improving the increase in dielectric constant and dielectric loss caused by excessive carbon black addition. It can be used in interior and exterior parts of automobiles that require dielectric properties.

Description

technical field [0001] The invention relates to the technical field of polymer materials, in particular to a low-dielectric polypropylene composite material and a preparation method thereof. Background technique [0002] As a cost-effective general-purpose plastic, polypropylene has the characteristics of high strength, high toughness, excellent mechanical properties, chemical resistance, and high heat resistance after modification. It is widely used in home appliances and automobile products, and polypropylene products used as decorative parts Color matching is required, and the color matching of automotive products is dominated by black, while the black tone of polypropylene is mainly achieved by adding carbon black, which also brings about the influence of carbon black dispersion on product blackness and gloss. . [0003] However, the dispersibility of carbon black is not good because it is easy to agglomerate during the melting and mixing process of polypropylene. Gener...

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Problems solved by technology

[0003] However, the dispersibility of carbon black is not good because it is easy to agglomerate during the melting and mixing process of polypropylene. Generally, those skilled in the art believe that carbon black with smaller fineness (larger specific surface area) is easier to agglomerate, so the carbon black used Often the range of nitrogen adsorption specific surface area is less than 250m 2 / g, resulting in the need to add an excessive amount of carbon black to the color matching of high-blackness products, which also introduces the problem of dispersion, affects the gloss of the material, and increases the dielectric constant and dielectric loss of the material.

[0004] Patent CN 101704974A discloses a preparation method of high-gloss polypropylene containing carbon black colorant, which uses carbon black and dispersant pre-dispersion method to improve the dispersibility of carbon black, and the selected carbon black particle size is 13 -70 microns, cannot achieve high black color matching, and is limited to ordinary products that do not require high blackness; in addition, CN 106854308 A discloses a preparation method of high-gloss black impact polypropylene, which also does not limit carbon black, According to the published L value data, it can be speculated that the nitrogen adsorption specific surface area range of the carbon black contained in the selected color masterbatch should fall within 200-250m 2 In the range of / g, at the same time, it can be seen from the examples that if the L value is lower than 25, the addition amount of the black masterbatch is as high as 3-4%, and the dispersion defect of carbon black is bound to be caused at such a high addition ratio. , at the same time, the addition of high content of color masterbatch will lead to the deterioration of the dielectric properties of polypropylene