Humidity-sensitive deformation sheet, humidity-sensitive deformation sheet manufacturing method and diaper surface layer structure

Abstract

The invention is suitable for the technical field of hygienic products, and provides a humidity-sensitive deformation sheet, a humidity-sensitive deformation sheet manufacturing method and a diaper surface layer structure. The humidity-sensitive deformation sheet comprises a flexible substrate and a hydrogel structure. The surface layer structure comprises a top sheet and the humidity-sensitive deformation sheet. Compared with the prior art in which the convex structure is directly processed on the surface layer of the diaper, the problem that the wearing comfort is reduced due to the fact that the height of the convex structure is reduced after the diaper is permeated by urine is solved to a certain extent. After urine permeates into the diaper, the protruding height of the protruding structure can still be kept. In addition, the absorption speed of the urine can be increased, and a bulge structure formed after the hydrogel structure absorbs water can guide the urine and store the baby excrement. Therefore, the wet and cold feeling of the baby skin is reduced, the baby skin is kept dry and breathable, and the wearing comfort of the diaper is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of sanitary products, and in particular relates to a moisture-sensitive deformable sheet, a method for manufacturing the moisture-sensitive deformable sheet, and a diaper surface structure. Background Art

[0002] Diapers are important sanitary products for infants during their growth stage. Each infant uses about 5 to 8 diapers every day, so the comfort of wearing diapers is closely related to the growth of infants. Among them, the contact area between the skin and the diaper surface is an important factor in the comfort of wearing diapers. By reducing the contact area between the skin and the diaper surface, the air circulation between the skin and the fabric can be improved, the moisture content on the diaper surface can be reduced, and the baby's skin can be kept warm, thereby increasing the wearing comfort. However, after the baby urinates, the contact area between the diaper surface and the skin of the diaper in the prior art will increase, resulting in the problem of poor wearing comfort of the diaper. Summary of the invention

[0003] The object of the present invention is to provide a moisture-sensitive deformable sheet, a method for manufacturing the moisture-sensitive deformable sheet and a diaper surface structure, aiming to solve the technical problem of poor wearing comfort of diapers in the prior art.

[0004] The present invention is implemented as follows. In a first aspect, a moisture-sensitive deformable sheet is provided, comprising a flexible substrate and a hydrogel structure arranged on the flexible substrate, wherein the hydrogel structure is arranged on the flexible substrate to form an embossed pattern, and the hydrogel structure is used to absorb water and swell so that the embossed pattern protrudes from the surface of the flexible substrate.

[0005] In an alternative embodiment,

[0006] The hydrogel structure comprises a plurality of protrusions spaced and distributed on the flexible substrate;

[0007] Alternatively, the hydrogel structure includes a plurality of mutually spaced transverse strips and a plurality of mutually spaced longitudinal strips, and the transverse strips and the longitudinal strips intersect with each other to form a grid-like structure.

[0008] In a second aspect, a method for manufacturing a humidity-sensitive deformable sheet is provided, comprising the following steps:

[0009] providing a flexible substrate, a mold, and a hydrogel solution;

[0010] Using a mold to apply the hydrogel solution to a preset area of ​​the flexible substrate;

[0011] The hydrogel solution is solidified to obtain a hydrogel structure and a moisture-sensitive deformation sheet.

[0012] In an optional embodiment, the mold includes a base plate and a cover plate, the base plate is provided with a molding groove, the cover plate is placed in the molding groove, a through groove structure is provided on the cover plate, the through groove structure is connected with the molding groove, and the position of the through groove structure corresponds to the position of the preset area.

[0013] In an optional embodiment, the step of applying the hydrogel solution to a preset area of ​​the flexible substrate using a mold further comprises the following steps:

[0014] placing the flexible substrate in the molding groove;

[0015] The cover plate is arranged above the flexible substrate, and a hydrogel solution is added into the through-groove structure so that the hydrogel solution flows through the through-groove structure onto the flexible substrate.

[0016] In an optional embodiment, in the step of curing the hydrogel solution, the hydrogel structure is cured by ultraviolet irradiation.

[0017] In an optional embodiment, the preparation of the hydrogel solution comprises the following steps:

[0018] Adding sodium hydroxide solution to excess acrylic acid to obtain acrylic acid-sodium acrylate solution;

[0019] An acrylic acid-sodium acrylate solution is added with a crosslinking agent to carry out a crosslinking reaction, and a photoinitiator is added to the obtained system to obtain a hydrogel solution.

[0020] In an alternative embodiment,

[0021] The weight of the crosslinking agent is 0.2-0.4% of the weight of the acrylic acid-sodium acrylate solution, the weight of the photoinitiator is 0.18-0.3% of the weight of the acrylic acid-sodium acrylate solution, the temperature of the crosslinking reaction is 43-48° C., and the reaction time of the crosslinking reaction is 2-3 hours.

[0022] In an optional embodiment, the photoinitiator is 2-hydroxy-2-methylacetone, and the cross-linking agent is N-N'methylenebisacrylamide.

[0023] In a third aspect, a surface structure is provided, comprising a top sheet and the moisture-sensitive deformable sheet as described in any one of the above items, wherein the top sheet and the moisture-sensitive deformable sheet are stacked and the top sheet is located on the side of the hydrogel structure away from the flexible substrate.

[0024] The first aspect of the present invention has the following technical effects relative to the prior art: the moisture-sensitive deformable sheet is arranged as the surface structure of the diaper at a position close to the baby's skin. After the diaper is penetrated by urine, the part of the flexible substrate where the hydrogel structure is arranged will expand after absorbing water, thereby forming a convex structure consistent with the embossed pattern on the flexible substrate. At this time, only the convex structure on the surface of the diaper is in contact with the baby's skin, reducing the contact area between the diaper surface and the baby's skin. Compared with the method of directly processing the convex structure on the surface of the diaper in the prior art, the present invention avoids the problem of the convex structure height reduction after the diaper is penetrated by urine, resulting in a decrease in wearing comfort. The convex height of the convex structure can still be maintained after the diaper is penetrated by urine. In addition, the presence of the hydrogel structure may also increase the absorption rate of urine, and the convex structure formed after the hydrogel structure absorbs water can also divert urine and store baby's feces. Thereby reducing the damp and cold feeling of the baby's skin, keeping the baby's skin dry and breathable, and improving the comfort of the diaper when wearing.

[0025] It can be understood that the beneficial effects of the second to fourth aspects mentioned above can be found in the relevant description of the first aspect mentioned above, and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments of the present invention or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0027] Figure 1 is a schematic structural diagram of a humidity-sensitive deformable sheet provided by an embodiment of the present invention;

[0028] Figure 2 It is a structural schematic diagram of a mold bottom plate provided by an embodiment of the present invention;

[0029] Figure 3 It is a structural schematic diagram of a mold cover plate provided by one embodiment of the present invention;

[0030] Figure 4 It is a schematic structural diagram of a surface structure provided by an embodiment of the present invention;

[0031] Figure 5 is a structural schematic diagram of a humidity-sensitive deformable sheet provided by another embodiment of the present invention;

[0032] Figure 6 is a structural schematic diagram of a mold cover plate provided by another embodiment of the present invention;

[0033] Figure 7is a partial cross-sectional structural schematic diagram of a mold cover plate provided by another embodiment of the present invention;

[0034] Figure 8 is a schematic structural diagram of a surface structure provided by another embodiment of the present invention;

[0035] Fig. 9 is a comparison diagram of peak heat flux at different infiltration times provided by an embodiment of the present invention;

[0036] Fig.10 is a comparison diagram of thermal conductivity at different infiltration times provided by an embodiment of the present invention;

[0037] Fig.11 It is a comparison chart of thermal resistance under different wetting times provided by an embodiment of the present invention.

[0038] Description of reference numerals:

[0039] 1. Humidity-sensitive deformable sheet; 11. Flexible substrate; 12. Hydrogel structure; 2. Top sheet; 3. Mold; 31. Bottom plate; 32. Cover plate; 33. Molding groove; 34. Through-groove structure. DETAILED DESCRIPTION

[0040] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0041] In the description of the present invention, it should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0042] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0043] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0044] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments.

[0045] Please refer to Figure 1 and Figure 5 As shown, in the first aspect, a moisture-sensitive deformation sheet 1 is provided, comprising a flexible substrate 11 and a hydrogel structure 12 arranged on the flexible substrate 11, the hydrogel structure 12 being arranged on the flexible substrate 11 to form an embossed pattern, and the hydrogel structure 12 being used to absorb water and swell so that the embossed pattern protrudes from the surface of the flexible substrate 11. Specifically, the flexible substrate 11 refers to a sheet-like component with a certain degree of softness, and the flexible substrate 11 can be an elastic material or a non-elastic material. The hydrogel structure 12 refers to a structure with a certain volume formed by hydrogel on the flexible substrate 11 by cross-linking or other means, and the shape of the hydrogel structure 12 can be any one of block, strip or wavy.

[0046] The embossed pattern refers to a pattern with a certain arrangement regularity distributed on the flexible substrate 11. The embossed pattern can be a dot matrix pattern composed of multiple blocks, strips or waves arranged at intervals from each other; or it can be a grid pattern composed of multiple strips, short strips or waves connected and crossed with each other.

[0047] The moisture-sensitive deformation sheet 1 provided in this embodiment uses hydrogel to form a hydrogel structure 12 on a flexible substrate 11, and the hydrogel structure 12 forms an embossed pattern. The moisture-sensitive deformation sheet 1 is set in the surface structure of the diaper. After the diaper is penetrated by urine, the part of the flexible substrate 11 where the hydrogel structure 12 is set will expand after absorbing water, and a convex structure consistent with the embossed pattern is formed on the flexible substrate 11. Only the convex structure on the surface of the diaper is in contact with the baby's skin, reducing the contact area between the diaper surface and the baby's skin. Compared with the method of directly processing the convex structure on the surface of the diaper in the prior art, the problem of the height of the convex structure decreasing after the diaper is penetrated by urine, which leads to a decrease in the wearing comfort of the diaper, is avoided to a certain extent. The convex height of the convex structure can still be maintained after the diaper is penetrated by urine. Thereby reducing the damp and cold feeling of the baby's skin, keeping the baby's skin dry and breathable, and improving the comfort of the diaper when wearing.

[0048] In one embodiment, Figure 1 As shown, the hydrogel structure 12 includes a plurality of raised blocks spaced apart on the flexible substrate 11. Specifically, the raised block refers to a block-shaped component having a certain volume, and the raised block may be any of a hemispherical, strip-shaped or other components having a certain volume. A plurality of hydrogel structures 12 are spaced apart on the flexible substrate 11 and are distributed in a lattice shape. After the hydrogel structure 12 absorbs water and swells, it can form interconnected flow channels on the surface of the flexible substrate 11, and urine can be diverted through the flow channels after the baby urinates, thereby avoiding the accumulation of urine to a certain extent and keeping the baby's skin dry and breathable. The flow channels formed on the surface of the flexible substrate 11 after the hydrogel structure 12 absorbs water and bulges can also form a storage space for storing baby feces when the diaper is lifted, thereby avoiding feces from flowing out of the diaper to a certain extent.

[0049] In one embodiment, Figure 1 As shown, the shape of the protrusion is hemispherical. Specifically, the protrusion is hemispherical, which can make the top surface of the formed hydrogel structure 12 smoother, so that the hydrogel structure 12 is more comfortable in contact with the skin after absorbing water, and the comfort of wearing the diaper can be further improved.

[0050] Based on the above-mentioned characteristic protrusions, the ratio of the maximum diameter of the protrusion to the distance between two adjacent protrusions is 1:10 to 3:5. Specifically, the hydrogel structure 12 is arranged on the flexible substrate with such a size ratio, so as to minimize the area occupied by the hydrogel structure 12 while avoiding the poor flow guiding effect caused by the flow channel size being too large on the surface of the flexible substrate 11, thereby reducing the manufacturing cost.

[0051] In a specific embodiment, a plurality of hemispherical hydrogel structures 12 are arranged in a transverse row on the flexible substrate 11. There are a plurality of the above-mentioned transverse rows on the flexible substrate 11, and two adjacent transverse rows are arranged at intervals from each other, and the hydrogel structures 12 in two adjacent transverse rows are arranged staggered from each other. The hydrogel structure 12 is hemispherical and has a maximum diameter of 5 mm. The spacing between two adjacent hydrogel structures 12 in the same transverse row is 8 mm, and the spacing between two adjacent transverse rows is 10 mm.

[0052] In another embodiment, Figure 5As shown, the hydrogel structure 12 includes a plurality of mutually spaced transverse strips and a plurality of mutually spaced longitudinal strips, and the transverse strips and the longitudinal strips are intersected to form a grid. Specifically, the transverse strips and the longitudinal strips refer to continuous strip-shaped components with a certain length, and the cross-sectional shapes of the transverse strips and the longitudinal strips can be any one of semicircular, elliptical or rectangular, and the cross-sectional shapes of the transverse strips and the longitudinal strips can be the same or different. The hydrogel structure 12 adopts a grid structure formed by the intersection of the transverse strips and the longitudinal strips, so that all the hydrogel structures 12 are connected together, ensuring the overall structural strength of the hydrogel structure 12. At the same time, the hydrogel structure 12 is connected in a grid shape, and a plurality of closed receiving grooves can be formed on the surface of the diaper after the hydrogel structure 12 absorbs water and expands, forming a receiving space for storing baby feces when the diaper is lifted, and to a certain extent, preventing feces from flowing out of the diaper.

[0053] In an optional embodiment, if Figure 5 As shown, the ratio of the width of the transverse strip to the distance between two adjacent transverse strips is 1:4 to 1:6, and the ratio of the width of the longitudinal strip to the distance between two adjacent longitudinal strips is also 1:4 to 1:6. Specifically, by arranging the hydrogel structure 12 on the flexible substrate with such a size ratio, the area occupied by the hydrogel structure 12 can be minimized while ensuring the supporting strength of the hydrogel structure 12 itself, thereby reducing the production cost of the diaper.

[0054] In a specific embodiment, the cross-sections of the transverse strips and the longitudinal strips are both rectangular, and the widths of the transverse strips and the longitudinal strips are both 2 mm. The spacing between two adjacent transverse strips is 10 mm, and the spacing between two adjacent longitudinal strips is also 10 mm, which can make the layout of the hydrogel structure 12 more reasonable.

[0055] In one embodiment, Figure 1 and Figure 5 As shown, the flexible substrate 11 is a non-woven fabric. Specifically, non-woven fabric refers to a fabric that does not require spinning and weaving. It is formed by directional or random arrangement of textile short fibers or filaments to form a fiber mesh structure, and then reinforced by mechanical, thermal bonding or chemical methods. The flexible substrate 11 is a hydrophilic non-woven fabric, which ensures the strength of the flexible substrate 11 while making the flexible substrate 11 more absorbent, and can also make the cross-linking fixation of the hydrogel structure 12 and the flexible substrate 11 more firmly.

[0056] In an optional embodiment, if Figure 1 and Figure 5 As shown, the mass of the nonwoven fabric is 15-20 g / m2, which can ensure the strength of the flexible substrate 11 while making the moisture-sensitive deformable sheet 1 lighter.

[0057] Second, as Figures 1 to 8As shown, the present invention also provides a method for manufacturing a humidity-sensitive deformable sheet 1, comprising the following steps:

[0058] providing a flexible substrate, a mold, and a hydrogel solution;

[0059] S1 . Use the mold 3 to cover the hydrogel solution in a preset area on the flexible substrate 11 .

[0060] Specifically, the preset area refers to the area where the embossed pattern is located on the flexible substrate 11. The mold 3 is used to control the shape of the hydrogel on the flexible substrate 11, and the mold 3 has a molding cavity that matches the shape of the hydrogel structure 12. The multiple molding cavities can be connected or disconnected. After the flexible substrate 11 is placed in the mold 3, the shape of the hydrogel can be controlled by the molding cavity, so that the hydrogel solution forms a hydrogel structure 12 of a specific shape on the flexible substrate 11.

[0061] S2, curing the hydrogel solution to obtain the hydrogel structure 12 and the moisture-sensitive deformable sheet 1.

[0062] Specifically, the hydrogel structure 12 on the flexible substrate 11 is solidified so that the hydrogel structure 12 is cross-linked on the flexible substrate 11 , thereby manufacturing the humidity-sensitive deformable sheet 1 .

[0063] In one embodiment, Figure 2 , Figure 3 and Figure 6 As shown, the mold 3 includes a base plate 31 and a cover plate 32, a molding groove 33 is provided on the base plate 31, the cover plate 32 is placed in the molding groove 33, and a through groove structure 34 is provided on the cover plate 32. The through groove structure 34 is connected to the molding groove 33, and the position of the through groove structure 34 corresponds to the position of the preset area on the flexible substrate 11. Specifically, the base plate 31 and the cover plate 32 both refer to plate-like components with a certain thickness. The molding groove 33 refers to a groove with a certain depth dimension concavely arranged on the base plate 31, and the shape of the molding groove 33 needs to match the shape of the flexible substrate 11 for accommodating the flexible substrate 11. The through groove structure 34 refers to a plurality of through grooves arranged on the cover plate 32 and arranged according to a certain rule, and the through grooves are arranged throughout the entire cover plate 32 in the depth direction, and the overall shape of the through groove structure 34 matches the embossed pattern.

[0064] In one embodiment, Figure 6 and Figure 7As shown, the through groove structure 34 is a plurality of pits arranged on the cover plate 32, and the plurality of pits are arranged in an array on the cover plate 32. A bottom opening is also provided at the bottom of the through groove structure 34. The provision of the bottom opening allows the hydrogel solution to enter the through groove structure 34 from the bottom opening when the cover plate 32 is pressed on the flexible substrate 11. The through groove structure 34 can form a hydrogel structure 12 arranged in a dot matrix on the flexible substrate 11, which can further save the amount of hydrogel.

[0065] In an optional embodiment, if Figure 7 As shown, the shape of the pit is any one of a hemispherical shape, an ellipsoid shape or other shapes with a certain curvature on the bottom surface, which can make the top surface of the formed hydrogel structure 12 smoother, so that the hydrogel structure 12 can be more comfortable in contact with the skin after absorbing water.

[0066] On the basis of the above-mentioned characteristic through groove structure 34, as Figure 7 As shown, the diameter of the main opening of the through-groove structure 34 is 5 mm, and the diameter of the bottom opening of the through-groove structure 34 is 3 mm.

[0067] In another optional embodiment, Figure 6 As shown, a plurality of pits are arranged in a transverse row, the distance between two adjacent pits in the same transverse row is 8 mm, the distance between two adjacent transverse rows is 10 mm, and the pits in two adjacent transverse rows are staggered.

[0068] In one embodiment, Figure 3 As shown, the cover plate 32 includes a plurality of connection blocks, and the plurality of connection blocks are arranged in an array. Two adjacent connection blocks are connected by a connection rod so that the plurality of connection blocks are connected into a whole cover plate 32, and the two adjacent connection blocks are arranged at intervals from each other. Specifically, the connection block refers to a block-shaped component with a certain volume, and the cross-sectional shape of the connection block can be any one of a square, a rectangle or a parallelogram. The connection rod refers to a rod-shaped component with a certain length, and the connection rod is usually a thinner rod to avoid taking up too much space. The gaps between the connection blocks are interconnected to form a grid-like through-groove structure 34, so that the hydrogel structure 12 formed on the flexible substrate 11 is also grid-like.

[0069] Based on the above-mentioned characteristic cover plate 32, as Figure 3 As shown, the cross section of the connecting block is a square, the length of the square is 10 mm, and the spacing between two adjacent connecting blocks is 2 mm.

[0070] In one embodiment, the step of providing a flexible substrate and a mold, and applying the hydrogel solution to a preset area of ​​the flexible substrate using the mold further comprises the following steps:

[0071] S11, placing the flexible substrate 11 in the molding groove 33;

[0072] S12, covering the cover plate 32 on the flexible substrate 11, adding the hydrogel solution into the through groove structure 34, so that the hydrogel solution flows through the through groove structure 34 to the flexible substrate.

[0073] Specifically, when the mold 3 is used, the flexible substrate 11 is placed in the molding groove 33, and the cover plate 32 is also placed in the molding groove 33 and pressed on the flexible substrate 11, and the cover plate 32 will occupy most of the space of the molding groove 33. At this time, the hydrogel solution can be poured into the molding groove 33 through the through groove structure 34, and the hydrogel solution will enter the through groove structure 34 on the cover plate 32 after soaking the flexible substrate 11. After the hydrogel solution is irradiated with ultraviolet rays, it will cross-link and solidify to form a hydrogel structure 12 on the flexible substrate 11, and the shape of the hydrogel structure 12 is also consistent with the shape of the through groove structure 34.

[0074] In one embodiment, in the step of curing the hydrogel structure, the hydrogel structure is cured by ultraviolet irradiation. The ultraviolet irradiation can make the photoinitiator in the hydrogel solution absorb the energy in the ultraviolet light, so that the hydrogel solution is polymerized and cross-linked and cured on the flexible substrate 11.

[0075] In an optional embodiment, when the hydrogel structure is irradiated with ultraviolet light, the irradiation time is 2 to 3 minutes. Specifically, the irradiation time is 2 to 3 minutes, which can ensure that the hydrogel solution is fully polymerized.

[0076] In one embodiment, the step of curing the hydrogel solution to obtain the hydrogel structure 12 and the moisture-sensitive deformable sheet 1 further includes the following steps:

[0077] S21. After the hydrogel solution is solidified on the flexible substrate, the flexible substrate is washed, and after washing, the flexible substrate and the hydrogel structure cross-linked on the flexible substrate are dried.

[0078] After being irradiated with ultraviolet rays, the flexible substrate 11 is taken out from the mold 3. The uncross-linked residual hydrogel solution on the flexible substrate 11 can be removed by washing, and then the volume of the hydrogel structure 12 can be reduced by drying, so that the surface of the flexible substrate 11 can be restored to a flat state, making it easier to wear the diaper.

[0079] In an optional embodiment, the washing liquid used in the washing step is an ethanol solution; the hydrogel that has not undergone cross-linking is easily soluble in ethanol, and washing with ethanol can clean the flexible substrate 11 more cleanly.

[0080] In one embodiment, Figure 1 As shown, the preparation of the hydrogel solution includes the following steps:

[0081] S3, adding sodium hydroxide solution to excess acrylic acid to obtain acrylic acid-sodium acrylate solution;

[0082] S4, adding a crosslinking agent to an acrylic acid-sodium acrylate solution to carry out a crosslinking reaction, and adding a photoinitiator to the obtained system to obtain a hydrogel solution.

[0083] Specifically, a 20 wt% sodium hydroxide solution is generally used, and the sodium hydroxide solution reacts with acrylic acid to obtain an acrylic acid-sodium acrylate solution with a neutralization degree of 60% to 90%. A crosslinking agent and a photoinitiator are added to the obtained acrylic acid-sodium acrylate solution, and when the hydrogel solution is irradiated with light of a certain wavelength, the hydrogel solution is polymerized and crosslinked and cured. The light of a certain wavelength can be ultraviolet light.

[0084] In one embodiment, the weight of the crosslinking agent is 0.2-0.4% of the weight of the acrylic acid-sodium acrylate solution, the weight of the photoinitiator is 0.18-0.3% of the weight of the acrylic acid-sodium acrylate solution, and the temperature of the crosslinking reaction is 43-48° C. and the reaction time is 2-3 hours. This can ensure the full crosslinking reaction and increase the reaction speed.

[0085] In one embodiment, the photoinitiator is 2-hydroxy-2-methyl acetone, and the crosslinker is N-N'methylene bisacrylamide. When preparing the hydrogel solution, the photoinitiator can be 2-hydroxy-2-methyl acetone, and the type of the crosslinker is not limited; the crosslinker can also be N-N'methylene bisacrylamide, but the type of the photoinitiator is not limited; 2-hydroxy-2-methyl acetone added to the sodium acrylate solution can also be used as the photoinitiator, and N-N'methylene bisacrylamide can be added as the crosslinker.

[0086] In one embodiment, in the step of preparing the sodium acrylate solution, the reaction temperature is 0-4°C and the reaction time is greater than or equal to 30 minutes. Specifically, the reaction temperature of 0-4°C can be achieved by placing the reaction in an ice bath environment. And the reaction time is greater than or equal to 30 minutes to ensure sufficient reaction.

[0087] Thirdly, Figure 4 and Figure 8As shown, a surface structure is provided, including a top sheet 2, and also including any of the above-mentioned moisture-sensitive deformable sheets 1, and the top sheet 2 and the moisture-sensitive deformable sheet 1 are stacked. And the top sheet 2 is located on the side of the hydrogel structure 12 away from the flexible substrate 11. Specifically, the top sheet 2 refers to a sheet-like component with a certain degree of softness. By stacking the top sheet 2 and the moisture-sensitive deformable sheet 1 to form a surface structure, the moisture-sensitive deformable sheet 1 can be prevented from directly contacting the baby's skin. The top sheet 2 can be connected to the moisture-sensitive deformable sheet 1 by any of the methods such as hot melt adhesive, sewing or hot pressing.

[0088] In an optional embodiment, if Figure 4 and Figure 8 As shown, the top sheet 2 is a hydrophilic non-woven fabric, which can be an elastic or non-elastic non-woven fabric, wherein the mass of the non-woven fabric is 20 to 40 g / m 2 .

[0089] It can be understood that the beneficial effects of the second to third aspects mentioned above can be found in the relevant description of the first aspect mentioned above, and will not be repeated here.

[0090] Embodiment 1

[0091] A 20 wt% sodium hydroxide solution is prepared, and the sodium hydroxide solution is added to excess acrylic acid-acrylic acid in an ice water bath, and reacted for 30 minutes to prepare a sodium acrylate solution with a neutralization degree of 70%;

[0092] Add 0.2 wt % of N-N'methylenebisacrylamide to the acrylic acid-sodium acrylate solution, stir at 45° C. for 2 h, and then add 0.18 wt % of 2-hydroxy-2-methylacetone to prepare a hydrogel solution;

[0093] The non-woven fabric (18g / m 2 ) is placed into the molding groove on the bottom plate, the cover plate (the through groove structure is a grid shape) is placed in the molding groove and covered on the non-woven fabric, an appropriate amount of hydrogel solution is added to the molding groove, and it is placed under ultraviolet light for 2 minutes.

[0094] The nonwoven fabric was taken out and the uncrosslinked solution was washed away with ethanol, and the moisture-sensitive deformable sheet was obtained after drying.

[0095] Use non-elastic non-woven fabric (20g / m 2 ) as the top sheet, the top sheet and the moisture-sensitive deformation sheet are combined by a hot-melt adhesive to prepare a sample, and the sample is marked as E1.

[0096] Embodiment 2

[0097] A 20 wt% sodium hydroxide solution is prepared, and the sodium hydroxide solution is added to excess acrylic acid in an ice water bath, and reacted for 30 minutes to prepare an acrylic acid-sodium acrylate solution with a neutralization degree of 90%;

[0098] Add 0.35 wt % of N-N'-methylenebisacrylamide to the acrylic acid-sodium acrylate solution, stir at 45° C. for 2 h, and then add 0.25 wt % of 2-hydroxy-2-methylacetone to prepare a hydrogel solution;

[0099] The non-woven fabric (18g / m 2 ) is laid flat on the bottom surface of the molding groove on the base plate, a cover plate (the through groove structure is a dot matrix composed of hemispherical shapes) is placed in the molding groove and covered on top of the non-woven fabric, an appropriate amount of hydrogel solution is added to the molding groove, and the entire mold is placed under ultraviolet light for 2 minutes.

[0100] The nonwoven fabric was taken out and the uncrosslinked solution was washed away with ethanol, and the moisture-sensitive deformable sheet was obtained after drying.

[0101] Use non-elastic non-woven fabric (20g / m 2 ) is used as the top sheet, and the top sheet and the moisture-sensitive deformation sheet are combined by sewing to obtain a sample, and the sample is marked as E2.

[0102] Embodiment 3

[0103] A 20 wt% sodium hydroxide solution is prepared, and the sodium hydroxide solution is added to excess acrylic acid in an ice water bath, and reacted for 40 minutes to prepare an acrylic acid-sodium acrylate solution with a neutralization degree of 60%;

[0104] Add 0.4 wt % of N-N'methylenebisacrylamide to the acrylic acid-sodium acrylate solution, stir at 48° C. for 3 h, and then add 0.3 wt % of 2-hydroxy-2-methylacetone to prepare a hydrogel solution;

[0105] The non-woven fabric (15g / m 2 ) is laid flat on the bottom surface of the molding groove on the base plate, a cover plate (the through groove structure is a dot matrix composed of multiple hemispherical shapes) is placed in the molding groove and covered on top of the non-woven fabric, an appropriate amount of hydrogel solution is added to the molding groove, and the entire mold is placed under ultraviolet light for 3 minutes.

[0106] The nonwoven fabric was taken out and the uncrosslinked solution was washed away with ethanol, and the moisture-sensitive deformable sheet was obtained after drying.

[0107] Use non-elastic non-woven fabric (30g / m 2 ) is used as the top sheet, and the top sheet and the moisture-sensitive deformation sheet are combined by sewing to obtain a sample.

[0108] Embodiment 4

[0109] A 20 wt% sodium hydroxide solution is prepared, and the sodium hydroxide solution is added to excess acrylic acid in an ice water bath, and reacted for 30 minutes to prepare an acrylic acid-sodium acrylate solution with a neutralization degree of 70%;

[0110] Add 0.4 wt % of N-N'methylenebisacrylamide to the acrylic acid-sodium acrylate solution, stir at 43° C. for 3 h, and then add 0.3 wt % of 2-hydroxy-2-methylacetone to prepare a hydrogel solution;

[0111] The non-woven fabric (20g / m 2 ) is laid flat on the bottom surface of the molding groove on the base plate, a cover plate (the through groove structure is hemispherical) is placed in the molding groove and covered on top of the non-woven fabric, an appropriate amount of hydrogel solution is added to the molding groove, and the entire mold is placed under ultraviolet light for 3 minutes.

[0112] The nonwoven fabric was taken out and the uncrosslinked solution was washed away with ethanol, and the moisture-sensitive deformable sheet was obtained after drying.

[0113] Use non-elastic non-woven fabric (40g / m 2 ) is used as the top sheet, and the top sheet and the moisture-sensitive deformation sheet are combined by hot pressing to obtain a sample.

[0114] The peak heat flux (q) of sample E1, sample E2 and the traditional diaper surface layer (marked as TSL) under different humid conditions was measured by contact warm and cold tester. max ), thermal conductivity (k) and thermal resistance (R ct ) were measured and compared, where the characteristics of the test samples are shown in Table 1:

[0115] Table 1

[0116]

[0117] in Fig. 9 The peak heat flux (q) of sample E1, sample E2 and sample TSL in dry state, after 1 min of soaking, after 5 min of soaking and after 10 min of soaking respectively. max ) comparison chart. Figure 6 The comparison results show that in the wet state after infiltration, the (q max ) value is 3 to 9 times lower than the sample TSL. The peak heat flux (q max) The larger the value, the more heat loss from the skin surface and the lower the skin temperature, making the skin feel colder. Compared with the traditional diaper surface TSL, the hydrogel structure on the surface of samples E1 and E2 can significantly reduce the heat loss of the skin after being soaked in urine, making the skin feel warmer after the diaper is soaked in urine.

[0118] Fig.10 The thermal conductivity (k) comparison diagram of sample E1, sample E2 and sample TSL in dry state, after 1 minute of immersion, after 5 minutes of immersion and after 10 minutes of immersion respectively. Figure 7 It can be seen that in the wet state, the thermal conductivity of sample E1 is the lowest, the thermal conductivity of sample E2 is the second lowest, and the thermal conductivity of sample TSL is the highest. Therefore, compared with sample TSL, the hydrogel structure on the surface of sample E1 and sample E2 can effectively reduce the thermal conductivity of the diaper after it is soaked in urine.

[0119] Fig.11 The thermal resistance (R) of sample E1, sample E2 and sample TSL in dry state, after 1 min of soaking, after 5 min of soaking and after 10 min of soaking respectively. ct ) value comparison chart. Figure 8 It can be seen that in a wet state, the thermal resistance value of sample E1 is the lowest, the thermal resistance value of sample E2 is the second lowest, and the thermal resistance of sample TSL is the lowest. Therefore, compared with sample TSL, the hydrogel structure on the surface of sample E1 and sample E2 can effectively increase the thermal resistance value after the diaper is soaked in urine.

[0120] Therefore, it can be concluded that the surface structure and diaper provided by the present invention can reduce the contact area between the baby's skin and the diaper surface when the diaper is soaked with urine without affecting other properties of the diaper, solve the problem of the cold and wet feeling of the baby when wearing the diaper for a long time, and make the diaper more comfortable to wear.

[0121] The above are only preferred embodiments of the present invention, and only specifically describe the technical principles of the present invention. These descriptions are only for explaining the principles of the present invention and cannot be interpreted as limiting the scope of protection of the present invention in any way. Based on the explanations here, any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention, and other specific implementations of the present invention that can be associated with by technicians in this field without creative labor, should be included in the scope of protection of the present invention.

Claims

1. A humidity-sensitive deformable sheet, characterized in that: The invention comprises a flexible substrate and a hydrogel structure arranged on the flexible substrate. The hydrogel structure is arranged on the flexible substrate to form an embossed pattern. The hydrogel structure is used for absorbing water and swelling so that the embossed pattern protrudes from the surface of the flexible substrate.

2. The humidity-sensitive deformable sheet according to claim 1, characterized in that: The hydrogel structure comprises a plurality of protrusions spaced apart and distributed on the flexible substrate; Alternatively, the hydrogel structure includes a plurality of transverse strips spaced apart from each other, and a plurality of longitudinal strips spaced apart from each other, and the transverse strips and the longitudinal strips intersect with each other to form a grid-like structure.

3. A method for manufacturing a humidity-sensitive deformable sheet, characterized in that: The steps include: providing a flexible substrate, a mold, and a hydrogel solution; Using a mold to apply the hydrogel solution to a preset area of ​​the flexible substrate; The hydrogel solution is solidified to obtain a hydrogel structure and a moisture-sensitive deformation sheet.

4. The method for manufacturing a humidity-sensitive deformable sheet according to claim 3, characterized in that: The mold includes a base plate and a cover plate, the base plate is provided with a molding groove, the cover plate is placed in the molding groove, the cover plate is provided with a through groove structure, the through groove structure is connected with the molding groove, and the position of the through groove structure corresponds to the position of the preset area.

5. The method for manufacturing a humidity-sensitive deformable sheet according to claim 4, wherein: The step of applying the hydrogel solution to a preset area of ​​the flexible substrate using a mold further includes the following steps: placing the flexible substrate in the molding groove; The cover plate is arranged above the flexible substrate, and a hydrogel solution is added into the through-groove structure so that the hydrogel solution flows through the through-groove structure to the flexible substrate.

6. The method for manufacturing a humidity-sensitive deformable sheet according to claim 3, wherein: In the step of curing the hydrogel solution, the hydrogel structure is cured by ultraviolet irradiation.

7. The method for manufacturing a humidity-sensitive deformable sheet according to claim 3, characterized in that: The preparation of the hydrogel solution comprises the following steps: Take an excess amount of sodium hydroxide solution and add it to acrylic acid to obtain acrylic acid-sodium acrylate solution; An acrylic acid-sodium acrylate solution is added with a crosslinking agent to carry out a crosslinking reaction, and a photoinitiator is added to the obtained system to obtain a hydrogel solution.

8. The method for manufacturing a humidity-sensitive deformable sheet according to claim 7, wherein: The weight of the crosslinking agent is 0.2-0.4% of the weight of the acrylic acid-sodium acrylate solution, the weight of the photoinitiator is 0.18-0.3% of the weight of the acrylic acid-sodium acrylate solution, the temperature of the crosslinking reaction is 43-48° C., and the reaction time of the crosslinking reaction is 2-3 hours.

9. The method for manufacturing a humidity-sensitive deformable sheet according to claim 7, wherein: The photoinitiator is 2-hydroxy-2-methylacetone, and the cross-linking agent is N-N'methylenebisacrylamide.

10. A surface structure, characterized in that: It comprises a top sheet and also comprises the moisture-sensitive deformable sheet as claimed in claim 1 or 2, wherein the top sheet and the moisture-sensitive deformable sheet are stacked and the top sheet is located on a side of the hydrogel structure away from the flexible substrate.

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