Composite foaming agent for rigid PVC foam material

Abstract

The invention discloses a composite foaming agent for a rigid PVC foam material. The foaming agent comprises the following raw materials, by weight: 5-10 parts of azodicarbonamide, 2-4 parts of diethyl azodicarboxylate, 2-3 parts of OBSH, 0.5-1.5 parts of lauryl sodium sulfate, 1-2 parts of sodium bicarbonate, 1-2 parts of zinc carbonate, 1-3 parts of urea, 0.5-0.8 part of lead stearate, 2-4 parts of citric acid, and 15-20 parts of glycol propyl ether. According to the invention, raw materials including urea, zinc carbonate, sodium bicarbonate, sodium dodecyl sulfate are adopted for modification of azodicarbonamide to prepare the composite foaming agent for rigid PVC foam material; and the composite foaming agent has advantages of decomposition temperature within the range of molding processing of rigid PVC foam material, basically balanced heat absorption-release, smooth decomposition rate, large deflating amount and no abruptness. The rigid PVC material prepared from the composite foaming agent has good mechanical properties, uniform and fine pores, thin pore wall, easily controlled processing conditions, and no emergence of burning.

Description

technical field [0001] The invention relates to a foaming agent, in particular to a composite foaming agent for rigid PVC foaming materials. Background technique [0002] Since the advent of rigid PVC foam, it not only has many advantages similar to natural wood, but also has the advantages of good flame retardancy, low moisture absorption, low thermal conductivity, good heat and sound insulation, and strong resistance to pests. Rigid PVC foam materials have successfully replaced natural wood in many fields, and at the same time have a very stable market in the world and the future development prospects are very promising. Azodicarbonamide is a commonly used organic foaming agent in the processing and molding of rigid PVC foaming materials. It has the advantages of small particles, low price, large outgassing capacity, non-toxicity, and good self-extinguishing property. However, the decomposition temperature of azodicarbonamide is high, which is beyond the temperature range...

AI Technical Summary

Problems solved by technology

However, the decomposition temperature of azodicarbonamide is high, which is beyond the temperature range of PVC resin molding processing, and azodicarbonamide is a strong exothermic foaming agent. When the decomposition speed is too fast, local overheating and foaming will occur. The sudden gas will not only cause uneven foaming, but also cause the decomposition of PVC resin, making the processing and molding conditions difficult to control

Therefore, it is difficult to use azodicarbonamide alone as a foaming agent to meet the requirements of the processing technology of rigid PVC foaming materials.

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