Asymmetric polyolefin degassing membrane and preparation method thereof

Abstract

The invention provides an asymmetric polyolefin degassing membrane which is provided with a porous support layer and a compact separation layer, wherein the average pore diameter of the support layeris 100-5000 nm, and the average pore diameter of the separation layer is 0.1-10 nm; the thickness of the separation layer is 0.5-5 [mu]m, and the thickness ratio of the separation layer to the supportlayer is 1:80-1:200. according to the asymmetric polyolefin film provided by the invention, the separation layer thickness is large, and the more proper thickness ratio of the separation layer to thesupport layer is realized; the polyolefin degassing film has better tensile property and remarkable corrosion resistance, liquid with low surface tension is effectively prevented from breaking through the film material, especially when the polyolefin degassing film is used for ink degassing, the breaking time is far longer than that of other polyolefin degassing films obtained by using solvent systems, and the service life of the polyolefin degassing film is greatly prolonged.

Description

technical field [0001] The present application relates to the technical field of filter membrane materials, in particular to an asymmetric polyolefin degassing membrane and a preparation method thereof. Background technique [0002] Polyolefin membrane is a branch of membrane filtration industry, which can be used in gas-liquid separation, liquid-liquid separation, gas-gas separation and other environments. Generally speaking, polyolefin films have a certain degree of hydrophobicity, which is especially suitable for ink degassing, liquid degassing, pure water deoxygenation and other fields; at the same time, because some polyolefin materials have certain hydrophilic properties, or can be hydrophilic It can also be used in industries such as pure water filtration and separation. In particular, some polyolefin materials have certain gas selectivity, and can also be used in gas separation fields such as nitrogen and oxygen separation. [0003] In actual production, the proces...

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Problems solved by technology

[0005] The polyolefin film obtained by using the above method has the following problems in applications such as ink degassing: the stretching rate of the film material per unit area is not enough, resulting in the film material being easily stretched and deformed in a shaking environment, and problems such as liquid leakage are prone to occur; The thickness of the separation layer is very thin, and the uniformity of the pore structure distribution in the separation layer is not good, resulting in poor mechanical strength of the membrane material, and also reduces the corrosion resistance of the membrane, which cannot prevent the breakthrough of liquids with low surface tension such as ink Membrane material; Oxygen flux is too high, and the tolerance of the membrane is not good when used for deoxygenation

[0006] In the prior art, the attention to the thermal phase separation method mainly focuses on the type and proportion of the diluent, the improvement and adjustment of the heating or stretching temperature, such as CN104707490, CN104552969B, CN108568220A, CN109621747, etc., but none of them can solve the above problems. problem solution

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