Polyamide composite material and preparation method thereof

Abstract

The invention discloses a polyamide composite material which comprises the following components in parts by weight: A) 20-80 parts of a compound of at least one polyamide E and at least one of polyamide I, polyamide II and polyamide III, wherein the content of amino terminal group in the polyamide E, the polyamide I, the polyamide II and the polyamide III is greater than the content of terminal carboxyl; and B) 0-35 parts of a filler. The polyamide composite material disclosed by the invention has the advantages of good laser welding effect and the like.

Description

technical field [0001] The invention relates to the technical field of polymer materials, in particular to a polyamide composite material and a preparation method thereof. Background technique [0002] Due to its excellent mechanical properties, chemical resistance, ease of processing, and fatigue creep resistance, polyamide materials are often used in electronic appliances, electric tools, and motor vehicles that have strict requirements on the working environment. In the automotive industry, polyamide materials are also widely used in interior and exterior trim, functional parts, and structural parts. Lightweight is the development trend of automobile materials, and more and more plastic parts appear in the parts under the hood of automobiles. In order to obtain auto parts with high structural strength, laser welding is mostly used for polyamide composite materials for cars, and the obtained parts have small joints, high strength and long service life. Laser welding part...

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Problems solved by technology

[0003] However, the choice of resin will also have varying degrees of impact on the laser welding effect

According to the welding effect, the defects of laser welding include: 1) weak welding strength; 2) unsatisfactory appearance

The reasons for the weakening of the welding strength are: the thickness of the part through the laser is too high or the laser transmittance is not good, so that the laser energy cannot fully reach the welding interface; there is a resin interface that is not fully melted and connected at the joint to generate heat. Mass conduction, or there is a gas cavity formed by the decomposition of laser ablation at the junction

Moreover, through laser welding, flashing will also occur: there are several reasons for flashing: 1. The fluidity of the material is too high, and the melting point or plasticizing temperature is low, that is, it is easy to overflow; 2. The gas generated by the decomposition of the material promotes melting Partial overflow; 3. High transmittance or high input laser power of the equipment, which promotes the occurrence of points 1 and 2

[0004] DuPont and BASF are looking for ways to improve laser welding from the aspect of pigments. For example, CN01804783 and WO2017EP052758 disclose the use of 2:1 type azo metal complexes, which do not solve the impact of components other than pigments on laser welding, and it is possible to add other pigments It will lead to an increase in cost, a decrease in some performance and a decrease in durability

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