Polyamide composite material as well as preparation method and application thereof

Abstract

The invention discloses a polyamide composite material which comprises the following components in parts by weight: 38-90 parts of polyamide resin; 5 to 40 parts of glass fiber; 5 to 25 parts of melamine cyanurate; and 0.4 to 2 parts of polyurethane. A certain amount of polyurethane is added into an MCA flame-retardant glass fiber reinforced polyamide material system, due to the strong polarity of a polyurethane molecular chain segment, the polyurethane molecular chain segment can serve as a'connecting bridge 'of polyamide resin and glass fibers, the interface bonding force between the glass fibers and the polyamide resin is improved, the candlewick effect of the glass fibers is effectively reduced, and the flame retardant property of the glass fibers is improved. The material has high glowing filament characteristics and excellent mechanical properties, can meet the use requirements of the current electronic and electric appliance field on the material, and is particularly suitable for the connector industry with higher requirements on the glowing filament characteristics and the mechanical properties.

Description

technical field [0001] The invention relates to the technical field of polymer materials, in particular to a polyamide composite material and its preparation method and application. Background technique [0002] Melamine cyanurate (MCA) is an important nitrogen-based flame retardant, which has the advantages of halogen-free, low toxicity, and low smoke, and is especially suitable for flame retardancy of polyamide materials. However, for glass fiber reinforced polyamide materials, due to the "candle wick effect" of glass fibers, the flame retardant effect of MCA will be greatly reduced, making it difficult for the material to obtain better flame retardant properties. [0003] In the field of electronic appliances, special attention is paid to the glow wire performance of materials, especially in some products used in extreme environments (such as miniature circuit breakers MCB or contactors, etc.), and it is proposed that materials should reach the glow wire test value (GWFI)...

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Problems solved by technology

Chinese patent application CN110317450A discloses that in the MCA flame-retardant polyamide material system, the glass fiber that has been calcined at a high temperature is used to make the glass fiber brittle, and it is easier to be ground to reduce the length size when sheared by the extruder screw. Thereby reducing the "wick effect" of the glass fiber and improving the glow wire performance of the material; however, this technology requires a long-term high-temperature calcination pre-treatment on the glass fiber, which greatly increases the processing procedure and processing time, and increases the material processing cost

Chinese patent application CN112745675A compounded by adding methyl triallyl isocyanurate and melamine cyanurate, the two have good compatibility, thereby improving the phase of melamine cyanurate in the matrix resin Capacitance, improve the glow wire performance of the material, and increase the crystallization temperature and crystallization speed of the material at the same time, so that the material has better injection molding performance; however, this method has limited effect on improving the glow wire performance of the material, and it is difficult to meet the needs of special electrical products. Material GWFI meets the high requirement of 960°C

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