Ultrathin polyethylene microporous breathable film

Abstract

The utility model discloses an ultrathin polyethylene microporous breathable film which is a composite film adopting a five-layer structure and comprises an inner layer, a secondary inner layer, a middle layer, a secondary outer layer and an outer layer, the gram weight ratio of the inner layer to the secondary inner layer to the middle layer to the secondary outer layer to the outer layer is 1: 1: 3-4: 1: 1. According to the ultrathin polyethylene microporous breathable film, the ultrathin polyethylene microporous breathable film is prepared by adopting a five-layer structure, so that the problem of leakage of filler in a stretching process can be effectively avoided, and calcium carbonate is more uniformly dispersed in the film.

Description

Technical Field

[0001] This utility model belongs to the field of polyethylene film technology, specifically relating to an ultra-thin polyethylene microporous breathable membrane. Background Technology

[0002] The structure of a microporous breathable membrane is formed by adding incompatible inorganic microparticle pore-forming agents to a polymer and then stretching it. Its structure contains numerous capillary-like micropores, creating channels for the sequential passage of gas. However, because the diameter of external liquid droplets is larger than the diameter of the micropores, they cannot pass through, thus providing breathable and waterproof properties. Microporous breathable membranes are currently mainly used in personal hygiene products and the medical field, such as sanitary napkins, panty liners, diapers, adult incontinence products, and disposable medical or surgical supplies.

[0003] Chinese patent CN111890767A discloses an ultra-thin polyethylene microporous breathable membrane and its preparation method, which includes an outer layer, a middle layer and an inner layer co-extruded by a blown film machine, and can be applied to infant diapers.

[0004] Chinese patent CN111875864B discloses a polyethylene (PE) microporous breathable membrane for medical protective clothing and its preparation method. The membrane is formed by three-layer co-extrusion blow molding of the outer, middle and inner layers using a blown film machine, and then subjected to an eight-roll online longitudinal MDO stretching process to obtain the PE microporous breathable membrane.

[0005] Chinese patent CN107283976B discloses a microporous polyethylene breathable film and its preparation method, including a printed layer, an intermediate layer and a heat-sealing layer, which is obtained by co-extrusion blow molding, providing a guarantee for lightweight and emission-reducing disposable hygiene products.

[0006] Chinese patent CN116278281A discloses a polyethylene microporous breathable membrane and its preparation method. It is made by compositing an inner membrane with two adjacent outer membranes. It has the advantages of not damaging the base membrane, good safety performance, simple operation, high porosity, and good control of membrane thickness and uniformity.

[0007] Chinese patent CN209141613U discloses a corona-coated heat-sealable cast polyethylene breathable membrane, comprising a heat-sealable layer, a core layer, and a corona-coated layer. The core layer is a modified polyethylene layer, specifically a blend of polyethylene layers of different densities. The breathable membrane is a porous breathable film with numerous micropores. This breathable membrane exhibits improved breathability.

[0008] However, current microporous polyethylene breathable films are all three-layer structures. But when the filler content in the microporous polyethylene breathable film is too high, agglomeration and precipitation occur. The three-layer structure of the breathable film cannot play a good barrier role. The precipitated filler will affect the breathability, tensile strength and other properties of the film, and the sensitization will be significantly increased. It is not suitable for personal hygiene and medical applications. Summary of the Invention

[0009] To address the aforementioned technical problems, this utility model provides an ultra-thin polyethylene microporous breathable membrane with a five-layer structure, which can reduce precipitation and increase moisture permeability.

[0010] To achieve the above objectives, this utility model provides an ultra-thin polyethylene microporous breathable membrane, wherein the breathable membrane is a five-layer composite membrane with a weight ratio of 1:1:3-4:1:1.

[0011] Preferably, the basis weight of the inner layer is 1.25-1.75 gsm; the basis weight of the second inner layer is 1.25-1.75 gsm; the basis weight of the middle layer is 5-7 gsm; the basis weight of the second outer layer is 1.25-1.75 gsm; and the basis weight of the outer layer is 1.25-1.75 gsm.

[0012] Preferably, the basis weight of the breathable membrane is 10-14 gsm.

[0013] Preferably, the inner layer, the second inner layer, the middle layer, the second outer layer, and the outer layer contain fillers.

[0014] More preferably, the filler is calcium carbonate or lipophilic calcium carbonate.

[0015] Preferably, the outer layer is a printing layer, and color graphic printing is completed by flexographic surface printing.

[0016] Preferably, the breathable membrane is obtained by blow molding five-layer co-extrusion, MDO stretching and corona treatment.

[0017] The beneficial effects of this invention are as follows: the use of a five-layer structure to prepare an ultra-thin polyethylene microporous breathable membrane can effectively avoid the problem of filler leakage during the stretching process, and make calcium carbonate more uniformly dispersed in the film, thereby reducing the precipitation of filler and improving the uniformity of the ultra-thin polyethylene microporous breathable membrane. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of the present invention. In the figure, 1 is the inner layer, 2 is the secondary inner layer, 3 is the middle layer, 4 is the secondary outer layer, 5 is the outer layer, and 6 is the filler. Detailed Implementation

[0019] The technical solution of this utility model will be further explained below with reference to the accompanying drawings and specific embodiments. It is worth noting that the following embodiments are only preferred embodiments of this utility model and should not be construed as limiting this utility model. The protection scope of this utility model should be determined by the content of the claims. Modifications or substitutions made by those skilled in the art to the technical solution of this utility model without creative effort all fall within the protection scope of this utility model.

[0020] Example 1

[0021] An ultra-thin polyethylene microporous breathable membrane is a five-layer composite membrane, comprising an inner layer 1, a second inner layer 2, a middle layer 3, a second outer layer 4, and an outer layer 5; the weight ratio of the inner layer 1, the second inner layer 2, the middle layer 3, the second outer layer 4, and the outer layer 5 is 1:1:3-4:1:1.

[0022] Preferably, the inner layer 1 has a basis weight of 1.25-1.75 gsm; the second inner layer 2 has a basis weight of 1.25-1.75 gsm; the middle layer 3 has a basis weight of 5-7 gsm; the second outer layer 4 has a basis weight of 1.25-1.75 gsm; and the outer layer 5 has a basis weight of 1.25-1.75 gsm.

[0023] Preferably, the basis weight of the breathable membrane is 10-14 gsm.

[0024] Preferably, the inner layer 1, the second inner layer 2, the middle layer 3, the second outer layer 4, and the outer layer 5 contain filler 6.

[0025] More preferably, the filler 6 is calcium carbonate or lipophilic calcium carbonate.

[0026] More preferably, the filler 6 has a content of 45-70% in each layer.

[0027] Preferably, the inner layer 1, the second inner layer 2, the middle layer 3, the second outer layer 4, and the outer layer 5 further contain polyethylene and / or copolymer polyethylene, as well as a lubricant.

[0028] More preferably, the content of polyethylene and / or copolymer polyethylene is 25-48%, and the content of lubricant is 1-3%.

[0029] Preferably, the outer layer 5 is a printing layer, which completes the color graphic printing through flexographic surface printing, thereby forming a colorful pattern that can be applied to diapers.

[0030] Preferably, the breathable membrane is obtained by blow molding five-layer co-extrusion, MDO stretching and corona treatment.

Claims

1. An ultra-thin polyethylene microporous breathable membrane, characterized in that: The breathable membrane is a five-layer composite membrane, including an inner layer (1), a secondary inner layer (2), a middle layer (3), a secondary outer layer (4), and an outer layer (5); the weight ratio of the inner layer (1), the secondary inner layer (2), the middle layer (3), the secondary outer layer (4), and the outer layer (5) is 1:1:3-4:1:

1.

2. The ultra-thin polyethylene microporous breathable membrane according to claim 1, characterized in that: The inner layer (1) has a basis weight of 1.25-1.75 gsm; the sub-inner layer (2) has a basis weight of 1.25-1.75 gsm; the middle layer (3) has a basis weight of 5-7 gsm; the sub-outer layer (4) has a basis weight of 1.25-1.75 gsm; and the outer layer (5) has a basis weight of 1.25-1.75 gsm.

3. The ultra-thin polyethylene microporous breathable membrane according to claim 1, characterized in that; The weight of the breathable membrane is 10-14 gsm.

4. The ultra-thin polyethylene microporous breathable membrane according to claim 1, characterized in that: The inner layer (1), the sub-inner layer (2), the middle layer (3), the sub-outer layer (4) and the outer layer (5) contain filler (6).

5. The ultra-thin polyethylene microporous breathable membrane according to claim 4, characterized in that: The filler (6) is calcium carbonate or lipophilic calcium carbonate.

6. The ultra-thin polyethylene microporous breathable membrane according to claim 1, characterized in that: The outer layer (5) is a printing layer, which completes the color graphic printing through flexographic printing.

7. The ultra-thin polyethylene microporous breathable membrane according to claim 1, characterized in that: The breathable membrane is obtained by blow molding, five-layer co-extrusion, MDO stretching, and corona treatment.

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