Three-layer coextrusion film for infusion and preparation method of three-layer coextrusion film

Abstract

The invention relates to a three-layer coextrusion film for medical infusion, which is low in cost, nontoxic, good in bonding property, air barrier property, flexibility and weatherability, high in heat-seal strength and transparency and easy to process, and comprises an inner layer A, a bonding layer B and an outer layer C, wherein the inner layer A is made from polypropylene random copolymer that is good in heat sealability and flexibility and high in transparency; the bonding layer B is made from ethylene-vinyl acetate copolymer containing 10%-40% of vinyl acetate; the outer layer C is a weather-proof layer and is made from PVC (polyvinyl chloride) resin that is low in cost, weather-proof, transparent and soft; and the mass of a plasticizer accounts for 30%-60% of that of the outer layer C. A three-layer coextrusion casting unit is the main production equipment of the film, the interface instability due to unmatched rheology in multilayer coextrusion is effectively avoided by controlling the processing temperature and processing flowability of all layers of resin materials, and the production efficiency and product quality are greatly improved.

Description

technical field [0001] The invention relates to a functional film, in particular to a multi-layer co-extruded film material used in medicine for packaging transfusion. Background technique [0002] As a traditional infusion method, glass infusion bottles have good transparency, compatibility, and water-gas barrier properties, but they also have disadvantages such as easy damage and inconvenient transportation. In recent years, the development of PVC as a medical infusion bag, blood bag, and infusion tube has become increasingly rapid. PVC has been widely recognized for its low cost, transparency, and flexibility in medical equipment, but PVC still exists as a medical infusion packaging material. Fatal flaws: [0003] (1) In order to make PVC more flexible, at least 30% plasticizers need to be added during PVC processing. Commonly used plasticizers are phthalate plasticizers, which can be dissolved in liquid medicine , bringing hidden dangers to the health of patients. [...

AI Technical Summary

Problems solved by technology

[0003] (1) In order to make PVC more flexible, at least 30% plasticizers need to be added during PVC processing. Commonly used plasticizers are phthalate plasticizers, which can be dissolved in liquid medicine , pose a threat to the health of the patient

[0004] (2) A small amount of vinyl chloride monomer remains in PVC resin, and vinyl chloride monomer is poisonous. Excessive content of vinyl chloride monomer will bring certain harm to people's health

[0005] (3) There are particles falling off in the PVC material, which affects the clarity of the drug and causes harm to the human body

[0006] (4) During the storage of PVC infusion bags, some liquid medicine will react with PVC, causing the liquid medicine to deteriorate

[0007] (5) PVC itself has a certain degree of air permeability and permeability, and long-term storage will affect the quality of the liquid medicine

[0010] Patents for multi-layer co-extruded infusion films have been published, most of which are polyolefin multi-layer co-extruded infusion films. Although polyolefin multi-layer co-extruded films have excellent mechanical properties, optical properties, weather resistance, and are non-toxic and environmentally friendly, they are relatively Compared with traditional PVC infusion soft bags, the cost is higher and the processing technology is more complicated

Some patents use PET as the outer material of the infusion multilayer material. PET has the advantages of good mechanical properties, excellent high temperature resistance, low temperature performance, surface gloss, etc., but the flexibility of PET is poor, and compared with polyolefin resin, PET’s The large difference in processing temperature and fluidity is prone to interface instability, which seriously affects the transparency, interface adhesion, edge properties, etc. of the product, and brings great difficulties to the processing technology.

There are also some patents that use polyamide as a barrier layer to prepare a multilayer film for medical infusion, which greatly improves the barrier performance of the multilayer infusion film, but some fibers will be produced during the production process, and the infusion process will enter the blood of the human body along with the liquid medicine. , causing harm to people's health

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