A composite waterproof and breathable film for diapers

Abstract

The present invention provides a composite waterproof and breathable membrane for diapers, relating to the technical field of diaper materials. The composite waterproof and breathable membrane for diapers comprises, from top to bottom, a surface layer, a waterproof and breathable layer, and a bottom layer. 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 coated with nano-silver ions. The modified polyvinyl alcohol microporous membrane structure comprises PVA, polyethylene glycol, and nano-silicon dioxide, and is prepared using a phase separation method. By providing a waterproof and breathable layer with a modified polyvinyl alcohol microporous membrane structure, the present invention can effectively improve the waterproof and breathable properties of diapers.

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

[0006] 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.

[0007] (2) Technical solution

[0008] 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;

[0009] 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.

[0010] 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.

[0011] Preferably, the method for preparing the modified polyvinyl alcohol microporous membrane structure of the waterproof and breathable layer comprises the following steps:

[0012] Step 1: Prepare the mixture:

[0013] PVA and polyethylene glycol were mixed in a weight ratio of 7:3 to obtain a mixed solution;

[0014] Step 2: Prepare the mixture:

[0015] adding nano-silicon dioxide to the mixed solution to obtain a mixture;

[0016] Step 3: Separation and molding:

[0017] The modified polyvinyl alcohol microporous membrane with a pore size of 0.1-1 μm is prepared from the mixture by a phase separation method.

[0018] Preferably, the particle size of the nano-silicon dioxide is 20-30 nm, and the addition amount is 5-10 wt %.

[0019] Preferably, the porosity of the modified polyvinyl alcohol microporous membrane is 35-50%, and the thickness is 10-25 μm.

[0020] Preferably, the thickness of the bottom layer is 8-15 μm, the porosity is ≥80%, the coating amount of nano silver ions of the bottom layer is 0.5-2 mg / m², and the antibacterial rate against Escherichia coli and Staphylococcus aureus is ≥99%.

[0021] The present invention further discloses a method for preparing a composite waterproof breathable membrane for diapers, which comprises the following steps based on the composite waterproof breathable membrane for diapers described above:

[0022] Step 1: Primary processing:

[0023] Using polypropylene non-woven fabric as the surface material, a waterproof and breathable layer of modified polyvinyl alcohol microporous membrane structure is attached to the bottom of the surface layer by hot pressing or bonding;

[0024] Step 2: Reprocessing:

[0025] An antibacterial thermoplastic polyurethane film is used as the base material, and a nano-silver ion solution is evenly coated on its surface. After drying, the base layer is attached to the bottom of the waterproof and breathable layer by hot pressing or bonding.

[0026] Step 3: Detection:

[0027] Each layer is quality tested to ensure that the waterproof, breathable and wear-resistant properties of the composite waterproof and breathable membrane meet the design requirements, and finally the finished product is obtained.

[0028] The present invention further discloses a method for preparing a composite waterproof breathable membrane for diapers. Based on the composite waterproof breathable membrane for diapers as described above, specifically, the surface layer, the waterproof breathable layer and the bottom layer material are laminated and bonded by an ultrasonic composite process, and the ultrasonic embossing density is 20-40 lines / cm, wherein the frequency of the ultrasonic composite process is 20-40kHz, the amplitude is 30-60μm, and the pressing time is 0.1-0.3s.

[0029] (3) Beneficial effects

[0030] The present invention provides a composite waterproof and breathable membrane for diapers, which has the following beneficial effects:

[0031] 1. The waterproof and breathable layer, constructed with a modified polyvinyl alcohol microporous membrane structure, effectively enhances the waterproof and breathable properties of the diaper. The modified polyvinyl alcohol microporous membrane structure ensures excellent waterproofing while allowing air to circulate, effectively preventing the formation of a hot and humid environment inside the diaper, reducing the occurrence of skin problems like diaper rash, and improving user comfort and health.

[0032] 2. By setting the 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 structure on its surface can enhance the overall wear resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 This is a schematic flow chart of the method for preparing a waterproof and breathable layer of the present invention;

[0034] Figure 2 The figure is a schematic flow chart of the method for preparing the composite waterproof breathable membrane of the present invention. DETAILED DESCRIPTION

[0035] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0036] Example 1:

[0037] The embodiment of the present invention provides a composite waterproof and breathable membrane for diapers. The composite waterproof and breathable membrane comprises, from top to bottom, a surface layer, a waterproof and breathable layer, and a bottom layer. 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. The bottom layer is an antibacterial thermoplastic polyurethane membrane, and its surface is coated with nano-silver ions.

[0038] The modified polyvinyl alcohol microporous membrane structure comprises PVA, polyethylene glycol and nano-silica, and the modified polyvinyl alcohol microporous membrane is prepared by a phase separation method.

[0039] Secondly, the surface weight is 10g / m², and the micron-level bump structure on the surface has a height of 0.1mm and a diameter of 0.2mm, distributed in an array with a spacing of 1mm.

[0040] like Figure 1 As shown, the preparation method of the modified polyvinyl alcohol microporous membrane structure of the waterproof and breathable layer includes the following steps:

[0041] Step 1: Prepare the mixture:

[0042] PVA and polyethylene glycol were mixed in a weight ratio of 7:3 to obtain a mixed solution;

[0043] Step 2: Prepare the mixture:

[0044] Adding nano-silicon dioxide with a particle size of 20 nm and an addition amount of 5 wt % to the mixed solution to obtain a mixture;

[0045] Step 3: Separation and molding:

[0046] The mixture was subjected to a phase separation method 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 was 35%, and the thickness was 10 μm.

[0047] The thickness of the bottom layer is 8μm, the porosity is ≥80%, the nano silver ion coating amount of the bottom layer is 0.5mg / m², and the antibacterial rate against Escherichia coli and Staphylococcus aureus is ≥99%.

[0048] like Figure 2 As shown, an embodiment of the present invention further provides a method for preparing a composite waterproof breathable membrane for diapers, based on the above composite waterproof breathable membrane for diapers, comprising the following steps:

[0049] Step 1: Primary processing:

[0050] Using polypropylene non-woven fabric as the surface material, a waterproof and breathable layer of modified polyvinyl alcohol microporous membrane structure is attached to the bottom of the surface layer by hot pressing or bonding;

[0051] Step 2: Reprocessing:

[0052] An antibacterial thermoplastic polyurethane film is used as the base material, and a nano-silver ion solution is evenly coated on its surface. After drying, the base layer is attached to the bottom of the waterproof and breathable layer by hot pressing or bonding.

[0053] Step 3: Detection:

[0054] Each layer is quality tested to ensure that the waterproof, breathable and wear-resistant properties of the composite waterproof and breathable membrane meet the design requirements, and finally the finished product is obtained.

[0055] Example 2:

[0056] The embodiment of the present invention provides a composite waterproof and breathable membrane for diapers. The composite waterproof and breathable membrane comprises, from top to bottom, a surface layer, a waterproof and breathable layer, and a bottom layer. 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. The bottom layer is an antibacterial thermoplastic polyurethane membrane, and its surface is coated with nano-silver ions.

[0057] The modified polyvinyl alcohol microporous membrane structure comprises PVA, polyethylene glycol and nano-silica, and the modified polyvinyl alcohol microporous membrane is prepared by a phase separation method.

[0058] Secondly, the surface weight is 15g / m², and the micron-level bump structure on the surface has a height of 0.2mm and a diameter of 0.4mm, distributed in an array with a spacing of 2mm.

[0059] like Figure 1 As shown, the preparation method of the modified polyvinyl alcohol microporous membrane structure of the waterproof and breathable layer includes the following steps:

[0060] Step 1: Prepare the mixture:

[0061] PVA and polyethylene glycol were mixed in a weight ratio of 7:3 to obtain a mixed solution;

[0062] Step 2: Prepare the mixture:

[0063] Adding nano-silicon dioxide with a particle size of 25 nm and an addition amount of 8 wt % to the mixed solution to obtain a mixture;

[0064] Step 3: Separation and molding:

[0065] The mixture was subjected to a phase separation method to prepare a modified polyvinyl alcohol microporous membrane with a pore size of 0.5 μm. The porosity of the modified polyvinyl alcohol microporous membrane was 45%, and the thickness was 20 μm.

[0066] The thickness of the bottom layer is 10 μm, the porosity is ≥80%, the nano silver ion coating amount of the bottom layer is 1.5 mg / m², and the antibacterial rate against Escherichia coli and Staphylococcus aureus is ≥99%.

[0067] like Figure 2 As shown, an embodiment of the present invention further provides a method for preparing a composite waterproof breathable membrane for diapers, based on the above composite waterproof breathable membrane for diapers, comprising the following steps:

[0068] Step 1: Primary processing:

[0069] Using polypropylene non-woven fabric as the surface material, a waterproof and breathable layer of modified polyvinyl alcohol microporous membrane structure is attached to the bottom of the surface layer by hot pressing or bonding;

[0070] Step 2: Reprocessing:

[0071] An antibacterial thermoplastic polyurethane film is used as the base material, and a nano-silver ion solution is evenly coated on its surface. After drying, the base layer is attached to the bottom of the waterproof and breathable layer by hot pressing or bonding.

[0072] Step 3: Detection:

[0073] Each layer is quality tested to ensure that the waterproof, breathable and wear-resistant properties of the composite waterproof and breathable membrane meet the design requirements, and finally the finished product is obtained.

[0074] Example 3:

[0075] The embodiment of the present invention provides a composite waterproof and breathable membrane for diapers. The composite waterproof and breathable membrane comprises, from top to bottom, a surface layer, a waterproof and breathable layer, and a bottom layer. 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. The bottom layer is an antibacterial thermoplastic polyurethane membrane, and its surface is coated with nano-silver ions.

[0076] The modified polyvinyl alcohol microporous membrane structure comprises PVA, polyethylene glycol and nano-silica, and the modified polyvinyl alcohol microporous membrane is prepared by a phase separation method.

[0077] Secondly, the surface weight is 20g / m², and the micron-level bump structure on the surface has a height of 0.3mm and a diameter of 0.5mm, distributed in an array with a spacing of 3mm.

[0078] like Figure 1 As shown, the preparation method of the modified polyvinyl alcohol microporous membrane structure of the waterproof and breathable layer includes the following steps:

[0079] Step 1: Prepare the mixture:

[0080] PVA and polyethylene glycol were mixed in a weight ratio of 7:3 to obtain a mixed solution;

[0081] Step 2: Prepare the mixture:

[0082] Adding nano-silicon dioxide with a particle size of 30 nm and an addition amount of 10 wt % to the mixed solution to obtain a mixture;

[0083] Step 3: Separation and molding:

[0084] The mixture was subjected to a phase separation method to prepare a modified polyvinyl alcohol microporous membrane with a pore size of 1 μm. The porosity of the modified polyvinyl alcohol microporous membrane was 50%, and the thickness was 25 μm.

[0085] The thickness of the bottom layer is 15 μm, the porosity is ≥80%, the nano silver ion coating amount of the bottom layer is 2 mg / m², and the antibacterial rate against Escherichia coli and Staphylococcus aureus is ≥99%.

[0086] like Figure 2 As shown, an embodiment of the present invention further provides a method for preparing a composite waterproof breathable membrane for diapers, based on the above composite waterproof breathable membrane for diapers, comprising the following steps:

[0087] Step 1: Primary processing:

[0088] Using polypropylene non-woven fabric as the surface material, a waterproof and breathable layer of modified polyvinyl alcohol microporous membrane structure is attached to the bottom of the surface layer by hot pressing or bonding;

[0089] Step 2: Reprocessing:

[0090] An antibacterial thermoplastic polyurethane film is used as the base material, and a nano-silver ion solution is evenly coated on its surface. After drying, the base layer is attached to the bottom of the waterproof and breathable layer by hot pressing or bonding.

[0091] Step 3: Detection:

[0092] Each layer is quality tested to ensure that the waterproof, breathable and wear-resistant properties of the composite waterproof and breathable membrane meet the design requirements, and finally the finished product is obtained.

[0093] Example 4:

[0094] The difference between this embodiment and the first embodiment is that the present embodiment provides a method for preparing a composite waterproof and breathable film for diapers. Specifically, the surface layer, the waterproof and breathable layer, and the bottom layer material are laminated and bonded by an ultrasonic composite process. The ultrasonic embossing density is 30 lines / cm, wherein the frequency of the ultrasonic composite process is 30 kHz, the amplitude is 45 μm, and the lamination time is 0.2 s.

[0095] Comparative Example:

[0096] Ordinary waterproof breathable membrane commonly found on the market.

[0097] Experimental example:

[0098] The composite waterproof breathable membranes prepared in the above-mentioned Examples 1, 2, 3 and 4 were subjected to performance comparison tests with the ordinary waterproof breathable membrane of the comparative example. The test results are as follows:

[0099]

[0100] In summary, the composite waterproof breathable membrane prepared by the present invention significantly improves key performance indicators such as hydrostatic pressure resistance, air permeability, and abrasion resistance compared to conventional waterproof breathable membranes commonly found on the market. Specifically, the composite waterproof breathable membranes of the examples all achieved a hydrostatic pressure resistance exceeding 2000 mmH2O, an air permeability exceeding 0.61 cfm, and an abrasion resistance exceeding 550 times, far exceeding the conventional waterproof breathable membranes of the comparative examples, verifying the effectiveness and reliability of the present invention. Therefore, the composite waterproof breathable membrane for diapers provided by the present invention not only improves the waterproof and breathable properties of diapers, but also significantly enhances their durability and comfort, providing infants and young children with a healthier and more comfortable wearing experience.

[0101] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A composite waterproof breathable membrane for diapers, characterized by: The composite waterproof and breathable membrane comprises, 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, and its surface is treated with nano-silver ion coating; The modified polyvinyl alcohol microporous membrane structure comprises PVA, polyethylene glycol and nano-silica, and is prepared by a phase separation method. The preparation method of the modified polyvinyl alcohol microporous membrane structure of the waterproof and breathable layer comprises the following steps: Step 1: Prepare the mixture: PVA and polyethylene glycol were mixed in a weight ratio of 7:3 to obtain a mixed solution; Step 2: Prepare the mixture: adding nano-silicon dioxide to the mixed solution to obtain a mixture; Step 3: Separation and molding: The modified polyvinyl alcohol microporous membrane with a pore size of 0.1-1 μm is prepared from the mixture by a phase separation method.

2. The composite waterproof breathable membrane for diapers according to claim 1, characterized in that: 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.

3. The composite waterproof breathable membrane for diapers according to claim 1, characterized in that: The particle size of the nano-silicon dioxide is 20-30 nm, and the addition amount is 5-10 wt %.

4. The composite waterproof breathable membrane for diapers according to claim 1, characterized in that: The modified polyvinyl alcohol microporous membrane has a porosity of 35-50% and a thickness of 10-25 μm.

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

6. A method for preparing a composite waterproof breathable membrane for diapers, based on the composite waterproof breathable membrane for diapers according to any one of claims 1 to 5, characterized in that: The following steps are involved: Step 1: Primary processing: Using polypropylene non-woven fabric as the surface material, a waterproof and breathable layer of modified polyvinyl alcohol microporous membrane structure is attached to the bottom of the surface layer by hot pressing or bonding; Step 2: Reprocessing: An antibacterial thermoplastic polyurethane film is used as the base material, and a nano-silver ion solution is evenly coated on its surface. After drying, the base layer is attached to the bottom of the waterproof and breathable layer by hot pressing or bonding. Step 3: Detection: Each layer is quality tested to ensure that the waterproof, breathable and wear-resistant properties of the composite waterproof and breathable membrane meet the design requirements, and finally the finished product is obtained.

7. A method for preparing a composite waterproof breathable membrane for diapers, based on the composite waterproof breathable membrane for diapers according to any one of claims 1 to 5, characterized in that: The surface layer, the waterproof and breathable layer and the bottom layer material are laminated together through an ultrasonic composite process, and the ultrasonic embossing density is 20-40 lines / cm, wherein the frequency of the ultrasonic composite process is 20-40kHz, the amplitude is 30-60μm, and the lamination time is 0.1-0.3s.

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