Halogen-free flame-retardant polybutylece terephthalate/glass fiber composite and preparation method thereof

Abstract

The invention discloses a halogen-free flame-retardant polybutylece terephthalate / glass fiber composite which is blended by the following components by mass percentage: 45-65% of polybutylece terephthalate, 5-15% of organic hypophosphite flame retardant, 5-17% of synergistic flame retardant, and 20-30% of alkali-free glass fiber, wherein an oxygen index of the composite is 27.0-34.5%; a vertical combustion grade of a 3.2mm-thick sample UL-94 is V-0; a vertical combustion grade of a 1.6mm-thick sample UL-94 is V-0, and a vertical combustion grade of a 0.8mm-thick sample UL-94 is (V-1)-(V-0). The invention further discloses a preparation method of the composite. According to the composite and the preparation method, organic hypophosphite and inorganic hypophosphite or a melamine derivative synergistic flame retardant are adopted for compounding and flame retardance, the addition amount of the flame retardants is small, the flame-retardant efficiency is high, the price of adopted organic hypophosphite is lower than that of diethyl hypophosphite, the preparation technology is simple, and the popularization and use are facilitated.

Description

technical field [0001] The invention belongs to the field of halogen-free flame-retardant polybutylene terephthalate / glass fiber composite material and its preparation technology, and specifically relates to a compound nitrogen-containing or phosphorus-containing synergistic retarder mainly based on branched chain alkyl phosphinate. A high flame-retardant polybutylene terephthalate / glass fiber composite material obtained from a flame retardant and a preparation method thereof. Background technique [0002] Polybutylene terephthalate (PBT) is a milky white translucent to opaque, crystalline thermoplastic polyester. Although it has excellent properties such as high toughness, low water absorption, chemical resistance, and processability Well, it has been widely used in many fields such as automobiles, electronics and electrical appliances, but because of its low notched impact strength and large molding shrinkage, it is often modified by filling reinforcing fibers or alloying....

AI Technical Summary

Problems solved by technology

Although this class of flame retardants, including the main flame retardants disclosed in CN101525479A, CN102264816A, etc., has good flame retardant effect in PBT, the dialkylphosphinate used in it is mainly diethylphosphinic acid Salt, methyl ethyl phosphinate and other substituents are phosphinates of alkyl substituents with 1 to 2 carbons, and this type of flame retardant is as described in the synthetic method disclosed in CN1660857A, because It needs to involve complex devices and processes such as high-pressure reactors, which makes the cost higher. In addition, the flame retardant is exclusively sold by Klein Company in Germany. The price in the market is high and the application is difficult to promote. It is the current situation that the flame retardant of PBT in the Chinese market is still dominated by halogenated flame retardants.

And when the alkyl phosphinate flame retardant is used alone, the addition amount of flame retardant glass fiber reinforced PBT needs to be more than 20% to make the 3.2mm product pass the vertical burning UL-94 V-0 level, and it needs to be combined with other flame retardants Compounding can improve the flame retardant efficiency, but there are still great challenges to make 0.8mm products reach UL-94 V-0 level

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