Composite waterproof breathable film for paper diaper

Abstract

The invention provides a composite waterproof breathable film for paper diapers, and relates to the technical field of paper diaper materials. The composite waterproof breathable film for the paper diaper sequentially comprises a surface layer, a waterproof breathable layer and a bottom layer from top to bottom, the surface layer is a polypropylene non-woven fabric, the surface of the surface layer is provided with a micron-sized salient point structure, the waterproof breathable layer is of a modified polyvinyl alcohol microporous film structure, the bottom layer is an antibacterial thermoplastic polyurethane film, and the antibacterial thermoplastic polyurethane film is of a hollow structure. The surface of the modified polyvinyl alcohol microporous membrane is subjected to nano silver ion coating treatment, the modified polyvinyl alcohol microporous membrane structurally comprises PVA, polyethylene glycol and nano silicon dioxide, and the modified polyvinyl alcohol microporous membrane is prepared by adopting a phase separation method. By arranging the waterproof breathable layer with the modified polyvinyl alcohol microporous membrane structure, the waterproof performance and the breathable performance of the paper diaper can be effectively improved.

Description

Technical Field

[0001] The present invention relates to the technical field of diaper materials, in particular to a composite waterproof and breathable film for diapers. Background Art

[0002] In the field of diapers, waterproof and breathable membranes are an important component of diapers and play a key role in their performance. However, there are some problems that need to be solved in the waterproof and breathable membranes of diapers currently on the market.

[0003] On the one hand, existing waterproof and breathable membranes are often relatively thin, resulting in poor wear resistance. Infants and young children, due to their active nature, frequently move their bodies while wearing diapers, subjecting the membrane to constant friction and stretching. This repeated, significant deformation can easily lead to localized failure of existing membranes, leading to leakage and significantly reducing the performance and reliability of diapers.

[0004] On the other hand, existing waterproof and breathable membranes struggle to balance breathability and waterproofness. It's difficult to achieve both high waterproofness and good breathability simultaneously. This results in either poor waterproofing, which can easily lead to urine leakage, or insufficient breathability, which creates a hot and humid environment inside diapers. This not only causes discomfort but can also lead to skin problems like diaper rash, seriously impacting user health and comfort. Summary of the Invention

[0005] (1) Technical problems solved In view of the deficiencies in the prior art, the present invention provides a composite waterproof and breathable membrane for diapers, which solves the problems raised by the above-mentioned background technology.

[0006] (2) Technical solution To achieve the above objectives, the present invention is implemented through the following technical solutions: a composite waterproof and breathable membrane for diapers, the composite waterproof and breathable membrane comprising, from top to bottom, a surface layer, a waterproof and breathable layer, and a bottom layer, wherein the surface layer is a polypropylene non-woven fabric having a micron-scale convex structure on its surface, the waterproof and breathable layer is a modified polyvinyl alcohol microporous membrane structure, and the bottom layer is an antibacterial thermoplastic polyurethane membrane, the surface of which is coated with nano-silver ions; The modified polyvinyl alcohol microporous membrane structure comprises PVA, polyethylene glycol and nano-silicon dioxide, and the modified polyvinyl alcohol microporous membrane is prepared by a phase separation method.

[0007] Preferably, the surface layer has a gram weight of 10-20 g / m², and the micron-scale convex structure of the surface layer has a height of 0.1-0.3 mm and a diameter of 0.2-0.5 mm, and is distributed in an array with a spacing of 1-3 mm.

[0008] Preferably, the preparation method of the modified polyvinyl alcohol microporous membrane structure of the waterproof and breathable layer comprises the following steps: Step 1: Prepare a mixed solution: Blend PVA and polyethylene glycol at a weight ratio of 7:3 to obtain a mixed solution; Step 2: Prepare a mixture: Add nano-silica to the above mixed solution to obtain a mixture; Step 3: Separate and form: Use the phase separation method to prepare a modified polyvinyl alcohol microporous membrane with a pore size of 0.1 - 1 μm from the above mixture.

[0009] Preferably, the particle size of the nano-silica is 20 - 30 nm, and the addition amount is 5 - 10 wt%.

[0010] Preferably, the porosity of the modified polyvinyl alcohol microporous membrane is 35 - 50%, and the thickness is 10 - 25 μm.

[0011] Preferably, the thickness of the bottom layer is 8 - 15 μm, the porosity ≥ 80%, the coating amount of nano-silver ions on the bottom layer is 0.5 - 2 mg / m², and the antibacterial rate against Escherichia coli and Staphylococcus aureus ≥ 99%.

[0012] The present invention further discloses a preparation method of a composite waterproof and breathable membrane for diapers. Based on the above-mentioned composite waterproof and breathable membrane for diapers, it comprises the following steps: Step 1: Primary processing: Use polypropylene non-woven fabric as the surface layer material, and attach the waterproof and breathable layer with the modified polyvinyl alcohol microporous membrane structure below the surface layer by hot pressing or bonding; Step 2: Further processing: Use the antibacterial thermoplastic polyurethane membrane as the bottom layer material, uniformly coat the nano-silver ion solution on its surface, and after drying, attach the bottom layer below the waterproof and breathable layer by hot pressing or bonding; Step 3: Detection: Conduct quality inspection on each layer to ensure that the waterproof performance, breathable performance and wear resistance of the composite waterproof and breathable membrane meet the design requirements, and finally obtain the finished product.

[0013] The present invention further discloses a preparation method of a composite waterproof and breathable membrane for diapers. Based on the above-mentioned composite waterproof and breathable membrane for diapers, specifically, laminate and combine the surface layer, waterproof and breathable layer and bottom layer materials through an ultrasonic composite process. The ultrasonic embossing density is 20 - 40 lines / cm, wherein the frequency of the ultrasonic composite process is 20 - 40 kHz, the amplitude is 30 - 60 μm, and the pressing time is 0.1 - 0.3 s.

[0014] (III) Beneficial effects The present invention provides a composite waterproof and breathable film for diapers, having the following beneficial effects: 1. By providing a waterproof and breathable layer with a modified polyvinyl alcohol microporous membrane structure, the waterproof performance and breathable performance of the diaper can be effectively improved. The adoption of the modified polyvinyl alcohol microporous membrane structure enables the waterproof and breathable layer to allow air circulation while ensuring a good waterproof effect, effectively avoiding the formation of a humid and hot environment inside the diaper, reducing the occurrence of skin problems such as diaper rash, and improving the comfort and health level of the user.

[0015] 2. By providing a surface layer of polypropylene non-woven fabric, the softness and comfort of the diaper can be increased. At the same time, the micron-level convex point structure on its surface can enhance the overall wear resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is a schematic flow chart of the preparation method of the waterproof and breathable layer of the present invention; Figure 2 is a schematic flow chart of the preparation method of the composite waterproof and breathable film of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0017] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0018] Example 1: The embodiment of the present invention provides a composite waterproof and breathable film for diapers. The composite waterproof and breathable film sequentially includes a surface layer, a waterproof and breathable layer, and a bottom layer from top to bottom. Among them, the surface layer is polypropylene non-woven fabric, and its surface has a micron-level convex point structure. The waterproof and breathable layer is a modified polyvinyl alcohol microporous membrane structure, and the bottom layer is an antibacterial thermoplastic polyurethane membrane, and its surface is coated with nano silver ions; The modified polyvinyl alcohol microporous membrane structure includes PVA, polyethylene glycol, and nano-silica, and the modified polyvinyl alcohol microporous membrane is prepared by the phase separation method.

[0019] Secondly, the grammage of the surface layer is 10 g / m², the height of the micron-level convex point structure of the surface layer is 0.1 mm, the diameter is 0.2 mm, and it is distributed in an array, and the spacing is 1 mm.

[0020] As Figure 1 shown, the preparation method of the modified polyvinyl alcohol microporous membrane structure of the waterproof and breathable layer includes the following steps: Step 1: Prepare a mixed solution: Mix PVA and polyethylene glycol in a weight ratio of 7:3 to obtain a mixed solution; Step Two: Prepare the mixture: Add nano-silica to the above-mentioned mixed solution. The particle size of the nano-silica is 20 nm, and the addition amount is 5 wt%, to obtain a mixture; Step Three: Separation and forming: Use the phase separation method on the above-mentioned mixture to prepare a modified polyvinyl alcohol microporous membrane with a pore size of 0.1 μm. The porosity of the modified polyvinyl alcohol microporous membrane is 35%, and the thickness is 10 μm.

[0021] The thickness of the bottom layer is 8 μm, the porosity is ≥80%, the coating amount of nano-silver ions on the bottom layer is 0.5 mg / m², and the antibacterial rate against Escherichia coli and Staphylococcus aureus is ≥99%.

[0022] As Figure 2 shown, the embodiment of the present invention also provides a preparation method of a composite waterproof and breathable membrane for diapers. Based on the above-mentioned composite waterproof and breathable membrane for diapers, it includes the following steps: Step One: Preliminary processing: Use polypropylene non-woven fabric as the surface layer material, and attach the waterproof and breathable layer with a modified polyvinyl alcohol microporous membrane structure under the surface layer by hot pressing or bonding; Step Two: Further processing: Use the antibacterial thermoplastic polyurethane membrane as the bottom layer material, evenly coat the nano-silver ion solution on its surface, and after drying, attach the bottom layer under the waterproof and breathable layer by hot pressing or bonding; Step Three: Detection: Conduct quality inspection on each layer to ensure that the waterproof performance, breathable performance and wear resistance of the composite waterproof and breathable membrane meet the design requirements, and finally obtain the finished product.

[0023] Example Two: The embodiment of the present invention provides a composite waterproof and breathable membrane for diapers. The composite waterproof and breathable membrane sequentially includes a surface layer, a waterproof and breathable layer and a bottom layer from top to bottom. Among them, the surface layer is polypropylene non-woven fabric, and its surface has a micron-level bump structure. The waterproof and breathable layer is a modified polyvinyl alcohol microporous membrane structure, and the bottom layer is an antibacterial thermoplastic polyurethane membrane, and its surface is treated with nano-silver ion coating; The modified polyvinyl alcohol microporous membrane structure includes PVA, polyethylene glycol and nano-silica, and the modified polyvinyl alcohol microporous membrane is prepared by the phase separation method.

[0024] Secondly, the grammage of the surface layer is 15 g / m², the height of the micron-level bump structure on the surface layer is 0.2 mm, the diameter is 0.4 mm, and it is distributed in an array, and the spacing is 2 mm.

[0025] As Figure 1 shown, a preparation method of a modified polyvinyl alcohol microporous membrane structure of a waterproof and breathable layer includes the following steps: Step 1: Prepare a mixed solution: Blend PVA and polyethylene glycol in a weight ratio of 7:3 to obtain a mixed solution; Step 2: Prepare a mixture: Add nano-silica to the above mixed solution. The particle size of the nano-silica is 25 nm, and the addition amount is 8 wt%, to obtain a mixture; Step 3: Separation and forming: Use the phase separation method to prepare a modified polyvinyl alcohol microporous membrane with a pore size of 0.5 μm from the above mixture. The porosity of the modified polyvinyl alcohol microporous membrane is 45%, and the thickness is 20 μm.

[0026] The thickness of the bottom layer is 10 μm, the porosity ≥ 80%, the coating amount of nano-silver ions on the bottom layer is 1.5 mg / m², and the antibacterial rate against Escherichia coli and Staphylococcus aureus ≥ 99%.

[0027] As Figure 2 shown, an embodiment of the present invention also provides a preparation method of a composite waterproof and breathable membrane for diapers. Based on the above composite waterproof and breathable membrane for diapers, it includes the following steps: Step 1: Primary processing: Use polypropylene non-woven fabric as the surface layer material, and attach the waterproof and breathable layer of the modified polyvinyl alcohol microporous membrane structure under the surface layer by hot pressing or bonding; Step 2: Secondary processing: Use the antibacterial thermoplastic polyurethane membrane as the bottom layer material, uniformly coat the nano-silver ion solution on its surface, and after drying, attach the bottom layer under the waterproof and breathable layer by hot pressing or bonding; Step 3: Detection: Conduct quality inspection on each layer to ensure that the waterproof performance, breathable performance, and wear resistance of the composite waterproof and breathable membrane meet the design requirements, and finally obtain the finished product.

[0028] Example 3: An embodiment of the present invention provides a composite waterproof and breathable membrane for diapers. The composite waterproof and breathable membrane sequentially includes a surface layer, a waterproof and breathable layer, and a bottom layer from top to bottom. Among them, the surface layer is polypropylene non-woven fabric, and its surface has a micron-level bump structure. The waterproof and breathable layer is a modified polyvinyl alcohol microporous membrane structure, and the bottom layer is an antibacterial thermoplastic polyurethane membrane, and its surface is treated with nano-silver ion coating; The modified polyvinyl alcohol microporous membrane structure includes PVA, polyethylene glycol, and nano-silica, and the modified polyvinyl alcohol microporous membrane is prepared by the phase separation method.

[0029] Secondly, the grammage of the surface layer is 20 g / m². The height of the micro bump structure on the surface layer is 0.3 mm, the diameter is 0.5 mm, and it is distributed in an array with a spacing of 3 mm.

[0030] As Figure 1 shown, a preparation method for a modified polyvinyl alcohol microporous membrane structure of a waterproof and breathable layer includes the following steps: Step 1: Prepare a mixed solution: Blend PVA and polyethylene glycol at a weight ratio of 7:3 to obtain a mixed solution; Step 2: Prepare a mixture: Add nano-silica to the above mixed solution. The particle size of the nano-silica is 30 nm, and the addition amount is 10 wt%, to obtain a mixture; Step 3: Separation and forming: Use the phase separation method to prepare a modified polyvinyl alcohol microporous membrane with a pore size of 1 μm for the above mixture. The porosity of the modified polyvinyl alcohol microporous membrane is 50%, and the thickness is 25 μm.

[0031] The thickness of the bottom layer is 15 μm, the porosity ≥ 80%, the coating amount of nano-silver ions on the bottom layer is 2 mg / m², and the antibacterial rate against Escherichia coli and Staphylococcus aureus ≥ 99%.

[0032] As Figure 2 shown, an embodiment of the present invention also provides a preparation method for a composite waterproof and breathable membrane for diapers. Based on the above-mentioned composite waterproof and breathable membrane for diapers, it includes the following steps: Step 1: Primary processing: Use polypropylene non-woven fabric as the surface layer material, and bond the waterproof and breathable layer of the modified polyvinyl alcohol microporous membrane structure under the surface layer by hot pressing or gluing; Step 2: Secondary processing: Use the antibacterial thermoplastic polyurethane membrane as the bottom layer material, uniformly coat the nano-silver ion solution on its surface, and after drying, bond the bottom layer under the waterproof and breathable layer by hot pressing or gluing; Step 3: Detection: Conduct quality inspection on each layer to ensure that the waterproof performance, breathable performance, and wear resistance of the composite waterproof and breathable membrane meet the design requirements, and finally obtain the finished product.

[0033] Example 4: The difference between this example and Example 1 lies in a preparation method for a composite waterproof and breathable membrane for diapers. Specifically, the surface layer, waterproof and breathable layer, and bottom layer materials are laminated and combined through an ultrasonic composite process. The ultrasonic embossing density is 30 strips / cm. Among them, the frequency of the ultrasonic composite process is 30 kHz, the amplitude is 45 μm, and the pressing time is 0.2 s.

[0034] Comparative example: Common ordinary waterproof and breathable membranes on the market.

[0035] Experimental example: The composite waterproof and breathable membranes prepared in the above Example 1, Example 2, Example 3 and Example 4 were subjected to performance comparison tests with the ordinary waterproof and breathable membrane of the comparative example, and the test results are as follows: In summary, compared with the common ordinary waterproof and breathable membranes on the market, the composite waterproof and breathable membranes prepared by the present invention have significantly improved in key performance indicators such as hydrostatic pressure resistance, air permeability and abrasion resistance times. Specifically, the hydrostatic pressure resistance of the composite waterproof and breathable membranes in the examples all reached above 2000 mmH2O, the air permeability all reached above 0.61 cfm, and the abrasion resistance times were as high as above 550 times, far exceeding the ordinary waterproof and breathable membranes of the comparative example, verifying the effectiveness and reliability of the present invention. Therefore, the composite waterproof and breathable membrane for diapers provided by the present invention not only improves the waterproof and breathable properties of diapers, but also significantly improves their durability and comfort, providing a healthier and more comfortable wearing experience for infants.

[0036] Although the embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions and variations can be made in these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A composite waterproof and breathable film for disposable diapers, characterized in that: The composite waterproof and breathable membrane comprises a surface layer, a waterproof and breathable layer, and a bottom layer from top to bottom. Among them, the surface layer is a polypropylene non-woven fabric, and its surface has a micron-level bump structure. The waterproof and breathable layer is a modified polyvinyl alcohol microporous membrane structure, and the bottom layer is an antibacterial thermoplastic polyurethane membrane, and its surface is treated by nano-silver ion coating; The modified polyvinyl alcohol microporous membrane structure comprises PVA, polyethylene glycol, and nano-silica, and the modified polyvinyl alcohol microporous membrane is prepared by the phase separation method.

2. The composite waterproof and breathable film for disposable diapers according to claim 1, wherein: The grammage of the surface layer is 10-20 g / m². The height of the micron-level bump structure of the surface layer is 0.1-0.3 mm, the diameter is 0.2-0.5 mm, and it is distributed in an array, with a spacing of 1-3 mm.

3. The composite waterproof and breathable film for disposable diapers according to claim 1, characterized in that: The preparation method of the modified polyvinyl alcohol microporous membrane structure of the waterproof and breathable layer comprises the following steps: Step 1: Prepare a mixed solution: Blend PVA and polyethylene glycol in a weight ratio of 7:3 to obtain a mixed solution; Step 2: Prepare a mixture: Add nano-silica to the above mixed solution to obtain a mixture; Step 3: Separation and forming: Use the phase separation method to prepare a modified polyvinyl alcohol microporous membrane with a pore size of 0.1-1 μm from the above mixture.

4. The composite waterproof and breathable film for disposable diapers according to claim 3, wherein: The particle size of the nano-silica is 20-30 nm, and the addition amount is 5-10 wt%.

5. The composite waterproof and breathable film for disposable diapers according to claim 3, wherein: The porosity of the modified polyvinyl alcohol microporous membrane is 35-50%, and the thickness is 10-25 μm.

6. The composite waterproof and breathable film for disposable diapers according to claim 1, wherein: The thickness of the bottom layer is 8-15 μm, the porosity ≥ 80%. The nano-silver ion coating amount of the bottom layer is 0.5-2 mg / m², and the antibacterial rate against Escherichia coli and Staphylococcus aureus ≥ 99%.

7. A preparation method of a composite waterproof and breathable film for a disposable diaper, based on the composite waterproof and breathable film for a disposable diaper according to any one of claims 1-6, characterized in that: Comprises the following steps: Step 1: Primary processing: Use the polypropylene non-woven fabric as the surface layer material, and bond the waterproof and breathable layer of the modified polyvinyl alcohol microporous membrane structure below the surface layer by hot pressing or adhesion; Step 2: Secondary processing: Use the antibacterial thermoplastic polyurethane membrane as the bottom layer material, evenly coat the nano-silver ion solution on its surface, and after drying, bond the bottom layer below the waterproof and breathable layer by hot pressing or adhesion; Step 3: Detection: Conduct quality inspection on each layer to ensure that the waterproof performance, breathable performance, and wear resistance of the composite waterproof and breathable membrane meet the design requirements, and finally obtain the finished product.

8. A preparation method of a composite waterproof and breathable film for disposable diapers, based on the composite waterproof and breathable film for disposable diapers according to any one of claims 1-6, characterized in that: The surface layer, waterproof and breathable layer, and bottom layer materials are laminated and combined by ultrasonic composite technology. The ultrasonic embossing density is 20-40 lines / cm. Among them, the frequency of the ultrasonic composite technology is 20-40 kHz, the amplitude is 30-60 μm, and the pressing time is 0.1-0.3 s.

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