Vehicular low-emission polypropylene composition and preparation method thereof

Abstract

The invention discloses a vehicular low-emission polypropylene composition and a preparation method thereof. The vehicular low-emission polypropylene composition comprises the following components in weight percentage: 40-94% of polypropylene A, 2-20% of polypropylene B, 2-20% of elastomer, 1-2% of liquid extractant, 0-30% of talcum powder and 1-3% of auxiliary agent. The preparation method comprises the following steps: firstly, mixing the polypropylene A, the polypropylene B, the elastomer, the liquid extractant and the auxiliary agent for 1-2 minutes in a high-speed mixer; secondly, adding the talcum powder and mixing for 3-5 minutes to obtain a premix; and finally, melting and extruding the premix by a twin-screw extruder, and performing two-stage vacuum granulation to obtain a finished product. Emission of free organic matters in the vehicular polypropylene can be reduced by introducing the polypropylene with a high melt strength and the liquid extractant; two-stage vacuum devolatilization can prolong the effective acting time of the time in the system, so that the prepared composition has a lower emission characteristic; and the preparation method is simple in process, low in equipment requirement and high in product yield.

Description

technical field [0001] The invention relates to a polypropylene composition, in particular to a low emission polypropylene composition for vehicles and a preparation method thereof. Background technique [0002] Because the car compartment is often in a closed state, its interior products such as leather seat covers or cloth seat covers will produce free formaldehyde, alkanes, benzene, toluene and other organic compounds, which will have adverse effects on the human body. In order to reduce the content of emanating substances in the material, it is necessary to control the source of raw materials, processing technology, additives, etc., or add substances that can react with these small molecule volatile substances to form a material with a larger molecular weight and less volatile energy. Compounds that are not easily volatile, so as to achieve the purpose of reducing the emitted substances. [0003] At present, two methods are mainly adopted at home and abroad to prepare l...

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Problems solved by technology

[0004] However, the method of reducing emanating substances through chemical reactions often only targets one factor and cannot solve the emanating problems caused by various factors at the same time; physical adsorption does not have specific selectivity and can adsorb all small molecules produced, but Adding molecular sieves to prepare low-emission polypropylene materials has two disadvantages: one is that no oily substances can be added to the system. In the actual production process, it is generally necessary to add a certain amount of white oil or mineral oil to obtain a composition with uniform properties. The filler adheres to the surface of the resin material, and after adding molecular sieve, it is easy to absorb oily substances, which makes the adsorption effect worse; secondly, the substances adsorbed by molecular sieves still exist in the system, and there is a risk of re-release under long-term heat aging and photoaging

[0005] 2. Polymer devolatilization, mainly adopts special devolatilization equipment and technology to carry out devolatilization in the process of polypropylene polymerization or modification, and the limitation of high cost of equipment required for devolatilization in the polymerization process is not easy to be widely used; patent CN200810023327. 5 discloses a method of adding a low-molecular organic matter remover during the modification process and then using a three-stage vacuum to prepare special materials for low-emission automotive interiors; however, the remover added by this method is difficult to stably disperse in the polymer melt , and the three-stage vacuum reduces the effective action time of the removal agent in the system, and the devolatilization efficiency is not high

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