Preparation method of polypropylene resin suitable for manufacturing medical infusion bottle by using injection stretch blow moulding process

Abstract

The invention relates to a preparation method of polypropylene resin suitable for manufacturing a medical infusion bottle by using an injection stretch blow moulding process, comprising the following steps of: evenly mixing polypropylene resin base material and additive and then melting, mixing and pelleting to obtain a polypropylene resin product, wherein the melting heating temperature is 190 to 250 DEG; the resin base material is propylene and ethylene random copolymer with the ethylene content of 0.5 to 4 percent by weight and the melting flow rate of 5.0 to 10.0g / 10min; the additive comprises an acid neutralizer, an antioxidant A and an antioxidant B, wherein the antioxidant A is selected from one of 1,3,5-trimethyl-2,4,6-tri(3,5-tertiary dibutyl-4 hydroxy benzyl) benzene, bi-(3,3-bi-(3-tertiary butyl-4-hydroxy phenyl)-butyrate) glycol ester and tetra(Beta-(3,5-tertiary dibutyl-4- hydroxy phenyl) propionic acid) pentaerythritol ester; and the antioxidant B is diphosphorous acid bi(2,4-teritiary dibutyl) pentaerythritol ester. The invention has the advantages that the thermal degradation resistance property of the prepared resin is greatly improved and is particularly suitable for an injection stretch blow moulding bottle-making process.

Description

technical field [0001] The invention relates to a preparation method of polypropylene resin, in particular to a preparation method of polypropylene resin specially used for manufacturing medical infusion bottles. Background technique [0002] At present, the raw materials for the manufacture of plastic medical infusion bottles basically use special polypropylene resin, which is a propylene-ethylene random copolymer with an ethylene content of less than 10 wt%. In terms of properties such as heat resistance, strength, toughness and transparency, it has obvious advantages compared with high polymer materials such as polyvinyl chloride used in the early stage, typically as described in US Patent US5,286,540 and Chinese Patent Application 200410017402.9 of. On the other hand, the bottle-making process of medical infusion bottles is mostly changed from the direct extrusion blow process to the injection stretch blow process, that is, the raw materials are first made into preforms...

AI Technical Summary

Problems solved by technology

In the prior art, the general polypropylene resin raw materials used to manufacture medical infusion bottles usually do not carry out targeted adjustments to antioxidant additives due to changes in the manufacturing process, so when used in the injection stretch blowing process, the anti-oxidant additives appear. Defects of unsatisfactory oxygen performance