One-way moisture-conducting and anti-adhesion dressing and preparation method and application thereof

Abstract

The present invention provides a unidirectional moisture-conducting and anti-adhesion dressing and its preparation method and application, which relate to the technical field of materials; the dressing comprises a hydrophilic layer and a hydrophobic pattern arrayed on the first surface of the hydrophilic layer and a hydrophilic pattern arrayed between the hydrophobic patterns and composed of the exposed hydrophilic layer and having a width of not less than 0.2 mm and not more than 5 mm; the structure of the hydrophobic pattern is that the surface of the hydrophobic pattern has a nanostructure / microstructure formed by a plurality of nano-protrusions / micro-protrusions in an array, and the surface of the hydrophobic pattern has a grease layer adsorbed; the volume proportion of the grease layer in the nanostructure / micro-structure is not less than 50% and not more than 125%. The unidirectional moisture-conducting and anti-adhesion dressing provided by the present application can improve the technical problem of poor anti-adhesion effect of unidirectional moisture-conducting dressings in the prior art.

Description

Technical Field

[0001] The present invention relates to the technical field of materials, and in particular to a unidirectional moisture-conducting and anti-adhesion dressing and a preparation method and application thereof. Background Art

[0002] In the process of treating open wounds, in order to reduce infection and promote drug absorption, dressings are usually used on the wound to achieve continuous drug action and cover to reduce bacteria and dust from entering the injured area. Since the performance of the dressing has a great influence on the healing progress of the wound and whether it causes infection, the choice of dressing has become an important medical tool for open wound healing.

[0003] According to the difference of dressing, including dry dressing and oily dressing. The dry dressing currently used, such as dressings such as cotton gauze, bandage, cotton cloth, after absorbing a large amount of wound exudate, may cause the interface of wound and dressing to dry and bring serious wound adhesion because these dressings do not have the ability to keep moisture. And oily dressing, by loading oily substances such as vaseline on dressing, can effectively reduce the adhesion of gauze fiber to wound, but this oily dressing does not have any ability to keep humidity and derive wound exudate, therefore in being applied to wound process, the problem of wound adhesion occurs easily. To this, the dressing of unilateral moisture conduction class is proposed in the prior art.

[0004] The existing one-way moisture-conducting dressings have the following main inner surface hydrophobic layers: one is a dressing that uses the capillary action of micron-level or even nano-level water-conducting channels to achieve rapid water conduction, such as covering the inner surface of the dressing with a porous hydrophobic layer. However, since the permeate discharged from the wound contains a large amount of body fluids, cell fluids, necrotic cells and other substances that easily block the water-conducting channels of the capillary action, it is difficult to maintain the water-conducting effect of the one-way moisture-conducting dressing, affecting the maintenance of its breathability, making the wound prone to slow healing due to over-wetting, and even causing infection problems; the second is to form a hydrophobic pattern on the inner surface of the dressing through a printing process or to form an uneven hydrophobic area by spraying a hydrophobic material. This method mostly uses a liquid hydrophobic composition as a raw material. Due to the diffusion of the liquid, the hydrophobic pattern and the hydrophilic pattern formed are difficult to control precisely, so the size, pattern, and area of ​​the hydrophobic area are difficult to control; and the hydrophobic pattern obtained by the glue printing method is often difficult to be compatible with the biocompatibility and bonding force of the glue used, which is not conducive to the use of the dressing. In addition, dressings can also be formed by electrospinning, but it not only has the problem of weak bonding, but also is greatly affected by electrospinning environmental factors, and has high requirements for production process parameters, which is not conducive to production and promotion. In addition, although unidirectional moisture-conducting dressings have improved the anti-adhesion of dressings to a certain extent, the improvement effect is not good and it is difficult to meet the requirements of dressings for open wounds. Summary of the invention

[0005] The purpose of the present application is to provide a unidirectional moisture-conducting and anti-adhesion dressing, so as to improve the technical problem of poor anti-adhesion effect of the unidirectional moisture-conducting dressing in the prior art.

[0006] Another object of the present application is to provide a method for preparing a unidirectional moisture-conducting and anti-adhesion dressing.

[0007] Another object of the present application is to provide an application of a unidirectional moisture-conducting and anti-adhesion dressing.

[0008] In the first aspect, based on the above technical problem, the present application provides a unidirectional moisture-conducting and anti-adhesion dressing, comprising a hydrophilic layer and a hydrophobic pattern arrayed on a first surface of the hydrophilic layer and a hydrophilic pattern arrayed between the hydrophobic patterns and composed of the exposed hydrophilic layer and having a width of not less than 0.2 mm and a thickness of not more than 5 mm;

[0009] The structure of the hydrophobic pattern is a porous structure and / or the surface of the hydrophobic pattern has a nanostructure / microstructure formed by a plurality of nanoprotrusions / microprotrusions in an array; a grease layer is adsorbed on the surface of the hydrophobic pattern;

[0010] The volume proportion of the grease layer in the nanostructure / microstructure is not less than 50% and not more than 125%; wherein the volume proportion of the grease layer in the nanostructure / microstructure is the percentage of the volume occupied by the grease layer in the pores in the nanostructure / microstructure to the total volume of the pores in the nanostructure / microstructure.

[0011] Further, in some embodiments of the present application, the 4-hour adhesion between the dressing and the skin tissue is not higher than 0.05N; wherein the 4-hour adhesion between the dressing and the skin tissue is detected by:

[0012] 1 mL of fresh sheep blood was dripped onto the surface of pig skin, and then the test dressing was covered on the sheep blood; it was placed at 25°C and 40% rh for 4 hours; the peeling adhesion test was performed using a dynamometer at a peeling speed of 30 cm / min and a peeling angle of 90°.

[0013] Furthermore, in some embodiments of the present application, the grease layer is continuously distributed in the porous structure of the hydrophobic pattern and / or the nanostructure / microstructure; the grease is at least one of lard, vaseline, silicone grease and paraffin.

[0014] Further, in some embodiments of the present application, the average pore size of the porous structure is 0.05 μm to 100 μm, and the porosity is 10% to 90%; and / or

[0015] The spacing between adjacent nano-protrusions / micro-protrusions is 0.05 μm-100 μm, and the height of the nano-protrusions / micro-protrusions is 0.1 μm-100 μm.

[0016] Furthermore, in some embodiments of the present application, the hydrophobic material is a lipophilic hydrophobic material having an adsorption effect on grease, the lipophilic hydrophobic material is a hydrophobic macromolecular polymer, and the adhesion performance of the hydrophobic macromolecular polymer to grease is greater than 100 kPa.

[0017] Further, in some embodiments of the present application, the area of ​​the hydrophobic pattern on the first surface accounts for no less than 44% or the area of ​​the hydrophilic pattern on the first surface accounts for no less than 44%.

[0018] The pattern does not exceed 78% of the area; and / or

[0019] The water contact angle of the hydrophobic material is 80° to 120°, and the oil contact angle of the hydrophobic material is not higher than 90°; and / or

[0020] The particle size of the powdered hydrophobic material is 50 mesh to 1000 mesh; and / or

[0021] The thickness of the hydrophobic pattern is 0.1 mm to 2 mm.

[0022] Furthermore, in some embodiments of the present application, part or all of the hydrophobic material is vertically immersed in the hydrophilic layer and forms an interlaced structure with the material of the hydrophilic layer; the thickness of the hydrophobic material vertically immersed in the hydrophilic layer is not less than 0.1 mm, and the width of the lateral diffusion on the hydrophilic layer is less than the thickness of the hydrophilic layer and is not greater than 0.2 mm.

[0023] Furthermore, in some embodiments of the present application, the spacing between adjacent hydrophobic patterns is not less than 1 mm or the spacing between adjacent hydrophilic patterns is not less than 1.5 mm.

[0024] Further, in some embodiments of the present application, the hydrophobic patterns constitute a hydrophobic region; the hydrophobic patterns constituting the hydrophobic region are distributed in isolation or in a continuous manner;

[0025] When the hydrophobic patterns are distributed in isolation, the spacing between adjacent hydrophobic patterns is not less than 1 mm;

[0026] When the hydrophobic patterns are distributed continuously, the distance between adjacent hydrophilic patterns is not less than 1.5 mm.

[0027] In a second aspect, the present application also provides a method for preparing a unidirectional moisture-conducting and anti-adhesion dressing, comprising:

[0028] Providing a hydrophilic layer and a hydrophobic material in powder form;

[0029] Using a mask having an array of hydrophobic patterns, an array of hydrophobic material patterns are formed on the first surface of the hydrophilic layer by an electrostatic powder spraying process; hot stamping the hydrophobic material pattern for 5 minutes to 15 minutes by a hot stamping process, and cooling to obtain a hydrophobic pattern;

[0030] Nano-protrusions / micro-protrusions are formed on the hydrophobic pattern by using an etching process, thereby obtaining a unidirectional moisture-conducting and anti-adhesion dressing.

[0031] Further, in some embodiments of the present application, in the hot stamping process, the hot stamping temperature is not lower than the glass transition temperature of the hydrophobic material and not higher than the direct ironing temperature of the hydrophilic layer; and / or

[0032] In the hot stamping process, the hot stamping pressure is 0.1 MPa to 0.5 MPa.

[0033] In a third aspect, the present application also provides a method for preparing a unidirectional moisture-conducting and anti-adhesion dressing, comprising:

[0034] providing a hydrophilic layer and a solution containing a hydrophobic material;

[0035] Using a mask plate with an array of hydrophobic patterns, a liquid film of an array of hydrophobic material patterns is formed on the first surface of the hydrophilic layer by a spray coating process;

[0036] The mask of the reticle is maintained to allow the hydrophobic material pattern liquid film to foam and solidify, thereby forming a hydrophobic material pattern with a porous structure, thereby obtaining a unidirectional moisture-conducting and anti-adhesion dressing.

[0037] In a fourth aspect, the present application further provides the use of the one-way moisture-conducting and anti-adhesion dressing described in the first aspect or the one-way moisture-conducting and anti-adhesion dressing prepared in the second aspect or the third aspect in the field of clothing.

[0038] The present application provides a unidirectional moisture-conducting and anti-adhesion dressing, which has a porous structure arrayed on one side of the hydrophilic layer or a plurality of microscopically raised hydrophobic patterns on the surface, and forms an extremely thin grease layer in the hydrophobic pattern, wherein the grease layer can not only provide partial hydrophobic performance for the hydrophobic pattern, but also reduce the adhesion of the hydrophobic pattern to the wound surface, thereby avoiding adhesion between the dressing and the wound; in addition, the presence of the grease layer can also keep the hydrophobic effect of the hydrophobic pattern stable, thereby keeping its unidirectional moisture-conducting effect stable; at the same time, the hydrophobic pattern array is on the hydrophilic layer, so that a millimeter-level unidirectional water-conducting channel is formed between the hydrophobic patterns on the hydrophilic layer, thereby avoiding the defect of easy blockage due to the small unidirectional water-conducting channel, and also avoiding the defect of easy adhesion to the wound due to the large area of ​​the unit hydrophilic pattern, thereby affecting the healing of the wound. The unidirectional water-conducting effect of the dressing provided by the present application can be maintained at more than 95% of the unidirectional water-conducting rate after continuous use for 4 hours in a high exudate environment, thereby achieving a long-term and stable unidirectional water-conducting function.

[0039] The present application also provides a method for preparing a unidirectional moisture-conducting and anti-adhesion dressing, which forms a hydrophobic pattern on the first surface of the hydrophilic layer through electrostatic powder spraying and hot stamping processes. The hydrophobic pattern has good consistency and uniform distribution, and its single pattern can be stable at the millimeter level; and the hydrophobic pattern has a strong binding force with the hydrophilic layer, and is not easy to fall off in a wet environment. After soaking in water for 4 hours, the peeling strength between the hydrophobic pattern and the hydrophilic layer can still reach more than 20N, which is conducive to the long-term and stable maintenance of the unidirectional water-conducting function, and also avoids the hydrophobic material from falling off into the wound and affecting wound healing; in addition, the dressing obtained by the preparation method has good consistency in unidirectional water-conducting performance, which is convenient for production and promotion. In addition, the preparation method provided by the present application can also be applied to long-term moisture-conducting fabrics for clothing, which are used to improve the problem that body fluids generated during human activities affect human comfort in a long-term manner.

[0040] The present application also provides a method for preparing a unidirectional moisture-conducting and anti-adhesion dressing. The preparation method uses a hydrophobic foaming liquid to foam at a limited position on a hydrophilic layer using a mask. The formed hydrophobic pattern has good consistency and uniform distribution. Moreover, since the hydrophobic pattern is obtained by foaming a foaming material, the hydrophobic material is partially embedded in the hydrophilic layer during the foaming process, so that the hydrophobic pattern has a strong bonding force with the hydrophilic layer and is not easy to fall off due to friction, which is beneficial to maintaining the stability of the unidirectional moisture-conducting function of the dressing.

[0041] The structure of the dressing provided in the present application can also form a one-way moisture-conducting fabric suitable for the clothing field by selecting a hydrophilic material suitable for clothing, which can achieve a long-lasting moisture-conducting effect and make the human body feel long-lasting comfort during exercise. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the specific implementation methods of the present application or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0043] Figure 1 This is a distribution diagram of the pore size in the horizontal direction and the pore size in the vertical direction of the unidirectional moisture-conducting and anti-adhesion dressing obtained in Example 1 of the present application;

[0044] Figure 2 This is a schematic structural diagram of the unidirectional moisture-conducting and anti-adhesion dressing obtained in Example 1 of the present application;

[0045] Figure 3 This is an enlarged view of part B of the unidirectional moisture-conducting and anti-adhesion dressing obtained in Example 1 of the present application;

[0046] Figure 4 Schematic diagrams of three typical structures obtained on the hydrophobic pattern of the unidirectional moisture-conducting and anti-adhesion dressing obtained in the present application;

[0047] Figure 5 The scanning electron microscope images of three typical structures obtained on the hydrophobic pattern of the unidirectional moisture-conducting and anti-adhesion dressing obtained in the present application;

[0048] Figure 6 The adhesion test results of the dressings of Examples 1 to 4, Comparative Example 1 and the reference example of the present application are shown in FIG.

[0049] Figure 7 A diagram showing the wound healing process of the dressing provided in Example 1 of the present application and the control dressing used on a rat wound;

[0050] Figure 8 A curve diagram showing changes in wound healing area when the dressing provided in Example 1 of the present application and the control dressing are used on rat wounds;

[0051] Fig. 9 The effect of the electrospinning time of the dressing provided in the present application on the peeling force between the hydrophobic material and the hydrophilic layer (A), and the effect of the hot stamping temperature and hot stamping time of the dressing provided in the present application on the peeling force between the hydrophobic material and the hydrophilic layer (B, C);

[0052] Fig.10 Schematic diagram of the test structure of the dressing obtained in the embodiment of the present application for a one-way water conduction speed experiment.

[0053] Among them, 10 is a hydrophilic layer; 11 is a hydrophobic pattern, 12 is a hydrophilic pattern; 20 is a hydrophobic material, 30 is a water droplet, and 40 is a syringe pump. DETAILED DESCRIPTION

[0054] The technical solution of the present application will be described clearly and completely below in conjunction with the embodiments. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0055] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are 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 ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0056] The disclosure below provides many different embodiments or examples to realize the different structures of the present application. In order to simplify the disclosure of the present application, the parts and settings of specific examples are described below. Of course, they are only examples, and the purpose is not to limit the present application. In addition, the present application can repeat reference numbers and / or reference letters in different examples, and this repetition is for the purpose of simplification and clarity, which itself does not indicate the relationship between the various embodiments and / or settings discussed. In addition, the examples of various specific materials provided by the present application, but those of ordinary skill in the art can be aware of the application of other processes and / or the use of other materials.

[0057] One-way water-conducting dressings for open wounds in the prior art usually form a porous hydrophobic layer with several micron-level or even submicron-level pores on the hydrophilic layer to achieve one-way water conduction and prevent wound exudate from accumulating at the wound, causing over-wetting of the wound and bacterial infection; at the same time, part of the exudate can also be retained in the hydrophilic layer to achieve wound moisturizing. However, since there are still some body cells and salts in the exudate from the wound, the dead cells and bacteria in the wound are easily retained in the porous hydrophobic layer, which will cause the one-way water-conducting effect of the one-way water-conducting dressing to quickly fail, which is not conducive to wound healing, and the improvement effect on wound adhesion is not obvious.

[0058] Therefore, based on the above problems, the inventor provides a unidirectional moisture-conducting and anti-adhesion dressing in the present application, see Figure 1~Figure 5 , comprising a hydrophilic layer 10 and an array, a hydrophobic pattern 11 and an array on a first surface of the hydrophilic layer 10, and a hydrophilic pattern 12 between the hydrophobic patterns 11 and consisting of the exposed hydrophilic layer 10 and having a width of not less than 0.1 mm and not more than 5 mm;

[0059] The structure of the hydrophobic pattern 11 is a porous structure and / or the surface of the hydrophobic pattern has a nanostructure / microstructure formed by a plurality of nanoprotrusions / microprotrusions in an array; and a grease layer is adsorbed on the surface of the hydrophobic pattern.

[0060] The structure on the hydrophobic pattern has an adsorption effect on grease, and can adsorb and retain an extremely thin (one monomolecular layer or multiple monomolecular layers) continuous grease layer within the range of the hydrophobic pattern on the surface of the hydrophobic pattern, so that some hydrophilic impurities are not easily attached to the hydrophobic pattern, and the defect of the hydrophobicity reduction on the surface of the hydrophobic pattern is slowed down, and the one-way water-conducting performance is maintained, and the problem of wound adhesion can be better reduced, and the biocompatibility of the dressing and the wound tissue can be improved, and the irritation of the dressing to the wound can be reduced; in addition, the medicine acting on the wound can also be better attached to the dressing to promote wound healing. It should be noted that the hydrophilic layer in the present application is a porous hydrophilic layer prepared by hydrophilic fiber material or other hydrophilic materials. The following is further explained by taking the hydrophilic layer prepared by hydrophilic fiber material as an example. Among them, the hydrophilic patterns prepared by hydrophilic fibers can be isolated from each other or interconnected, that is, there can be no connection between single hydrophilic patterns, or they can be connected through one end. When the hydrophilic patterns are isolated from each other, the "width" in this application refers to the minimum spacing between two adjacent hydrophilic patterns; when adjacent hydrophilic patterns are interconnected, the "width" in this application refers to the minimum spacing between the edge of the hydrophilic pattern and the nearest hydrophobic pattern, that is, the minimum spacing between non-continuous adjacent hydrophobic patterns.

[0061] In the present application, a single hydrophilic pattern and a single hydrophobic pattern can form a pattern unit, and the pattern units can be arranged in an array on the first surface of the dressing, and the minimum width of the one-way water-conducting channel formed by the hydrophilic pattern in each pattern unit is at least greater than 0.1 mm, so that the one-way water-conducting channel on the dressing can reach and stabilize at the micrometer level, avoiding the one-way water-conducting channel being too thin and easy to be blocked, and also avoiding the hydrophilic pattern being too wide and causing the hydrophilic fiber area to collapse, and obvious contact with the wound, resulting in local adhesion. Preferably, the width of the hydrophilic pattern is not less than 0.2 mm and not more than 2 mm; more preferably, the width is not less than 0.5 mm and not more than 1.5 mm.

[0062] In the present application, the hydrophobic pattern on the surface of the dressing is continuous, and the grease layer is also continuously distributed in the porous structure of the hydrophobic pattern and / or the nanostructure / microstructure, and the thickness of the grease layer is equal to or less than the thickness of the hydrophobic pattern. Specifically, the volume proportion of the grease layer in the nanostructure / microstructure is not less than 50% and not more than 125%; wherein, the volume proportion of the grease layer in the nanostructure / microstructure is the percentage of the volume occupied by the grease layer in the pores in the nanostructure / microstructure to the total volume of the pores in the nanostructure / microstructure.

[0063] Furthermore, in the present application, the thickness of the oil layer is extremely thin, and its thickness is preferably not less than the monomolecular layer of oil and not more than the thickness of the surface nanostructure / microstructure of the hydrophobic pattern. In other words, the oil layer is not formed on the surface of the hydrophobic pattern, but is embedded in the side of the hydrophobic pattern close to the human skin to be covered. It should be noted that in the present application, the continuous oil layer refers to continuous film formation in the area of ​​the hydrophobic pattern, rather than a complete continuous film formation on the surface of the dressing.

[0064] The porous structure of the hydrophobic material 20 used in the present application and / or the nanostructure / microstructure formed by the array of nano-protrusions / micro-protrusions on the surface of the hydrophobic pattern can have a significant retention effect on hydrophobic greases and achieve long-term unidirectional water conduction. Moreover, the hydrophobicity of the hydrophobic material itself will cause the hydrophobic greases to be preferentially adsorbed and retained on the surface of the hydrophobic pattern, and the surface will spontaneously polymerize to form a grease layer.

[0065] Wherein, the grease layer includes a number of grease molecules, and the grease molecules include at least one of lard, vaseline, silicone grease and paraffin. These selected grease molecules have strong biocompatibility. Further preferably, the grease in the grease layer provided in the present application not only maintains the hydrophobicity of the hydrophobic pattern and the grease layer, but also reduces the grease in the body fluid being adsorbed in the hydrophilic layer area, so that it maintains a long-term unidirectional water conduction. In addition, the grease molecules in the grease layer have a certain fluidity, which can move relatively freely in the grease layer, so that the grease molecules in the grease layer are evenly distributed, and the grease molecules and thickness in the grease layer are kept in dynamic balance. Moreover, due to the array of the hydrophobic pattern and the distribution of the hydrophilic area, the grease molecules are confined to the hydrophobic pattern area, which can further strengthen and stabilize the hydrophobic properties of the hydrophobic pattern.

[0066] Furthermore, the oil is preferably lard and vaseline, because lard is similar to the oil secreted by humans and has no skin irritation to the wound site; vaseline has strong hydrophobicity, and the self-pump dressing coated with vaseline has a high one-way fluid conduction rate, and currently vaseline-impregnated gauze dressings have been widely used in clinical wound treatment.

[0067] The unidirectional moisture-conducting and anti-adhesion dressing provided by the present application not only has a good and stable unidirectional moisture-conducting effect, and the moisture-conducting effect is extremely stable, but also can almost completely avoid adhesion to the wound after 4 hours of application, which is not only better than conventional unidirectional moisture-conducting dressings, but also better than conventional oily gauze specially used to overcome wound adhesion. The 4h adhesion between the dressing provided by the present application and the skin tissue can be controlled within the range of no more than 0.05N; wherein, the detection method of the 4h adhesion between the dressing and the skin tissue is:

[0068] 1 mL of fresh sheep blood was dripped onto the surface of pig skin, and then the test dressing was covered on the sheep blood; it was placed at 25°C and 40% rh for 4 hours; the peeling adhesion test was performed using a dynamometer at a peeling speed of 30 cm / min and a peeling angle of 90°.

[0069] It can be seen that the dressing provided in the present application is not only optimized in maintaining the unidirectional moisture conduction performance, but also has a significant improvement in improving wound adhesion, which is beneficial to wound healing.

[0070] In some embodiments, the hydrophobic material is a hydrophobic polymer. The adhesion performance of the hydrophobic polymer to oils and fats (such as lard, vaseline, silicone grease and paraffin) is greater than 100 kPa. The hydrophobic polymer is insoluble in water or nearly insoluble in water, and is difficult to form a suspension in water. At the same time, it also has a high adsorption performance for oils and fats, which is conducive to the oils and fats secreted by the body being adsorbed on the surface of the hydrophobic polymer.

[0071] Exemplarily, in the present application, the polymer selected for the hydrophobic material may be polypropylene, polyvinyl chloride, polyurethane (polyurethane), polyamide, polyacrylonitrile, etc., or other polymers that may be lipophilic and have a melting temperature below the direct ironing temperature of the fiber may be selected.

[0072] In some embodiments, the hydrophobic material is only any one or more of the above-mentioned polymers without adding other additives, so that the composition of the hydrophobic material is simple, the impact on the wound is reduced, and it is easy to produce and promote.

[0073] The hydrophobic pattern is a nano / micro structure with a plurality of nano-protrusions / micro-protrusions on the surface, the spacing between adjacent nano-protrusions / micro-protrusions is 0.05μm~100μm, and the height of the nano-protrusions / micro-protrusions is 0.1μm~100μm; preferably, the spacing between adjacent nano-protrusions / micro-protrusions is 10μm~100μm, and further preferably, the spacing between adjacent nano-protrusions / micro-protrusions is 50μm~100μm, preferably, the height of the nano-protrusions / micro-protrusions is 10μm~100μm, and further preferably, the height of the nano-protrusions / micro-protrusions is 30μm~100μm. While improving the hydrophobicity of the hydrophobic pattern, a microscopic structure that can absorb and retain grease can also be formed, so that a continuous grease layer is formed in the hydrophobic pattern area to maintain the hydrophobicity of the hydrophobic pattern.

[0074] The morphology of the nano-protrusions / micro-protrusions may be any morphology, for example, the nano-protrusions / micro-protrusions may be columnar protrusions, conical protrusions, spherical protrusions, and the like.

[0075] In addition, in other embodiments, the nanostructure / microstructure on the surface of the hydrophobic pattern can be provided by a porous structure of a hydrophobic material. When the hydrophobic pattern is a porous structure, the average pore size of the porous structure is 0.05μm~100μm and the porosity is 20μm~90%; preferably, the porous structure has an average pore size of 1μm~100μm and a porosity of 30μm~80%, and further preferably, the porous structure has an average pore size of 30μm~90μm and a porosity of 40μm~75%. It should be noted that the pores in the porous structure of the hydrophobic pattern in the present application can be interconnected so that the grease layer formed by it is continuous on the hydrophobic pattern to maintain the hydrophobicity of the hydrophobic pattern.

[0076] The grease molecules are adsorbed in the microstructure of the hydrophobic pattern and are evenly distributed in the hydrophobic pattern to form a continuous or discontinuous composite layer of grease molecules infiltrated with hydrophobic materials with a thickness of 0.1 μm to 100 μm. The grease molecules can move freely on the surface and / or porous structure of the hydrophobic material. In some embodiments, the thickness of the grease layer formed on the hydrophobic pattern is generally controlled to be within the range of 0.1 μm to 100 μm, or slightly higher than the height of the microstructure of the hydrophobic pattern. Exemplarily, the thickness of the composite layer of grease molecules infiltrated with hydrophobic materials can be 0.1 μm to 100 μm. It should be noted that the free movement of grease molecules described in this application means that the grease molecules can diffuse in the grease layer at a speed higher than the solid diffusion speed, so that the grease layer formed by it appears as a liquid film layer or close to a liquid film layer, and the distribution of grease molecules in the grease layer achieves dynamic equilibrium. In addition, the microstructure on the hydrophobic pattern can also be provided by the surface pores of the porous hydrophobic pattern and the connecting structure between the pores for supporting the formation of the pores, so as to increase the adsorption of oil on the surface of the hydrophobic pattern and stabilize the unidirectional water-conducting performance of the dressing.

[0077] In some embodiments, the height of the microstructure of the hydrophobic pattern surface is controlled to be 0.1~50μm, and even further controlled to be 0.1μm~10μm. At the same time, the grease layer is also controlled to be 0.05μm~60μm, and even further controlled to be 0.05μm~12μm. In some embodiments, the area proportion of the hydrophobic pattern on the first surface is not less than 44%, and the area proportion of the hydrophilic pattern is not more than 78%; preferably, the area proportion of the hydrophobic pattern is 44%~78%; more preferably, it is 50%~70%; the sum of the area proportion of the hydrophilic pattern and the area proportion of the hydrophobic pattern is equal to 100%.

[0078] In the present application, the area ratio of the hydrophobic pattern should not be too high or too low. This is because a too high hydrophobic area ratio means that the area ratio of the hydrophilic pattern is too small, and its one-way water guide channel is less, which is not conducive to one-way moisture conduction; if the area ratio of the hydrophobic pattern is too low, the hydrophilic pattern will be too large, which will easily cause the hydrophilic material to deform and adhere to the wound, affecting the adhesion of the wound, and also affecting the water conduction effect.

[0079] In some embodiments, the water contact angle of the hydrophobic material is 80°~120°, the oil contact angle of the hydrophobic material is not higher than 90°, preferably the water contact angle is 90°~110°, and the water contact angle of the hydrophilic layer is less than 20°, preferably 0°, so that the hydrophilic layer and the hydrophobic pattern form an obvious hydrophilic-hydrophobic gradient effect, thereby improving the unidirectional water guide effect.

[0080] In some embodiments, the thickness of the hydrophobic pattern is 0.1 mm to 0.5 mm, preferably 0.1 mm to 0.3 mm. The thickness of the hydrophobic pattern should not be too thick, especially not higher than 1 mm. An overly thick hydrophobic pattern will cause pressure on the wound and affect wound healing. If the structure of the dressing provided in this application is applied to clothing fabrics, the thickness of the hydrophobic pattern can be further increased to within 2 mm, preferably 0.5 μm to 1 mm, so as to form a certain space for air circulation between the skin and the hydrophilic layer, so as to make it more breathable.

[0081] Part or all of the hydrophobic material is immersed in the hydrophilic layer, and the thickness of the hydrophobic material vertically immersed in the hydrophilic layer is not less than 0.1 mm and less than the thickness of the hydrophilic layer, and the width of the lateral diffusion on the hydrophilic layer is not more than 0.2 mm.

[0082] It should be noted that the "immersion" described in this application refers to the flow of the hydrophobic material in a certain direction toward the hydrophilic layer in a liquid state, thereby expanding the coverage of the hydrophobic material. Among them, the thickness of the hydrophobic material vertically immersed in the hydrophilic layer is the distance that the hydrophobic material flows into the hydrophilic layer in a molten state. The thickness of the hydrophobic material vertically immersed in the hydrophilic layer should not be too high. When the hydrophobic material reaches the other side of the hydrophilic layer (the side corresponding to the first side), it will cause the hydrophilic layer to be hydrophobic on the other side, and it is difficult to achieve a fast unidirectional water guide effect. The width of the lateral diffusion of the hydrophobic material should not be too high, because if the lateral diffusion of the hydrophobic material is too large, it will cause the unidirectional water guide channel between adjacent hydrophobic patterns to be reduced, and the hydrophobic pattern will be deformed too much, affecting the efficiency and stability of the unidirectional water guide effect; if the adjacent hydrophobic patterns are connected or close to being connected, it will cause the first side to be completely hydrophobic or close to completely hydrophobic, so that its unidirectional water guide effect disappears or significantly decreases.

[0083] In the present application, the hydrophobic pattern can be a completely continuous pattern without micropores, or a pattern with a plurality of through holes inside, that is, in the present application, the micropores formed in the hydrophobic pattern during the melt stamping process do not affect the unidirectional water guide effect.

[0084] In some embodiments, the spacing between adjacent hydrophobic patterns is not less than 1 mm or the spacing between adjacent hydrophilic patterns is not less than 1.5 mm; preferably, the spacing between adjacent hydrophobic patterns is 1 mm to 3 mm or the spacing between adjacent hydrophilic patterns is 1.5 mm to 4 mm.

[0085] In the present application, since the hydrophobic pattern can be distributed continuously or in isolation, when the hydrophobic pattern is distributed in isolation, the spacing between adjacent hydrophobic patterns is not less than 1 mm; when the hydrophobic pattern is distributed continuously, the spacing between adjacent hydrophilic patterns is not less than 1.5 mm.

[0086] In some embodiments, when the hydrophobic pattern or the hydrophilic pattern is an isolated distributed pattern, the shape of the hydrophobic pattern or the hydrophilic pattern can be any regular or irregular shape, such as it can be circular, triangular, quadrilateral, semicircular, crescent, elliptical, cross, or hexagonal.

[0087] In addition, in order to facilitate those skilled in the art to understand the technical solution provided in the present application, a method for preparing a unidirectional moisture-conducting and anti-adhesion dressing is also provided in the present application, comprising:

[0088] Providing a hydrophilic layer and a hydrophobic material in powder form;

[0089] Using a mask having an array of hydrophobic patterns, an array of hydrophobic material patterns are formed on the first surface of the hydrophilic layer by an electrostatic powder spraying process; hot stamping the hydrophobic material pattern for 5 minutes to 15 minutes by a hot stamping process, and cooling to obtain a hydrophobic pattern;

[0090] Nano-protrusions / micro-protrusions are formed on the hydrophobic pattern by using an etching process, thereby obtaining a unidirectional moisture-conducting and anti-adhesion dressing.

[0091] The electrostatic powder spraying method is to spray powder coatings with an electrostatic powder spray gun, and make the powder particles negatively charged while dispersing. The charged powder particles are affected by airflow (or other effects such as centrifugal force) and electrostatic attraction, and are coated on the grounded object to be coated, and then heated, melted and solidified into a film. Among them, the powdered hydrophobic material used in this application can be made negatively charged by an electrostatic generator, which is specifically: the electrostatic generator releases high-voltage static electricity through the spray gun electrode needle, so that the mixture of the sprayed powder and compressed air is negatively charged; thus, an electric field is formed between the spray gun and the grounded workpiece. The powder reaches the surface of the workpiece under the dual push of the electric field force and the compressed air pressure, and forms a uniform coating on the surface of the workpiece by electrostatic attraction.

[0092] After the pattern is formed by spraying, the hydrophobic material is melted by hot stamping technology, partially immersed in the hydrophilic layer, and forms an interlaced structure with the hydrophilic material. After cooling and solidifying the hydrophobic material, a unidirectional moisture-conducting and anti-adhesion dressing is obtained. Among them, the dressing provided in the present application is used multiple times and washed. If there is a large loss, in addition to absorbing the sweat discharged by the human body to form a layer of grease, a layer of grease can also be quickly formed by spraying or automatic scraping to achieve the rapid repair of the unidirectional water-conducting performance of the fabric.

[0093] The preparation method is simple, has few process steps, uses relatively simple raw material components, has low precision requirements on processing parameters, is easy to operate, and is easy to promote and use.

[0094] In some embodiments, the material used for the hydrophilic layer can be any one or more of the commercially available hydrophilic materials that can be used for clothing, such as cotton, synthetic viscose fiber, silk, and linen.

[0095] In some embodiments, in the hot stamping process, the hot stamping temperature is not lower than the glass transition temperature of the hydrophobic material and not higher than the direct ironing temperature of the hydrophilic layer, so as to avoid damage to the hydrophilic layer due to excessively high hot stamping temperature. Exemplarily, when the hydrophobic material is polyurethane, the hot stamping temperature in the hot stamping process is 160°C to 180°C, and more preferably 170°C to 180°C.

[0096] In some embodiments, in the hot stamping process, the hot stamping time should not be too short. Too short a hot stamping temperature is not conducive to the hydrophobic material invading the hydrophilic layer, affecting the water-guiding ability. Exemplarily, when the hydrophobic material is polyurethane, the hot stamping time in the hot stamping process is 5 minutes to 15 minutes, and more preferably 10 minutes to 15 minutes.

[0097] In some embodiments, in the hot stamping process, the hot stamping pressure is 0.1MPa~0.5MPa, preferably 0.2MPa~0.4MPa. The hot stamping pressure should not be too high to avoid the molten hydrophobic material from penetrating into the other side of the hydrophilic layer at the same hot stamping temperature and time, affecting the unidirectional water conduction ability.

[0098] According to whether the hydrophobic pattern to be formed is isolated or continuous, the mask can be an insulating mask or a conductive mask, and the insulating mask is provided with a plurality of arrays of pattern holes. That is, when the hydrophobic pattern to be formed is an isolated pattern, the mask used is an insulating mask such as a polyimide plate. During the electrostatic spraying process, the hydrophilic layer is placed under the insulating mask, and the hydrophobic powder with static electricity will be concentrated in the pattern holes to form a hydrophobic material pattern; after the spraying is completed, the hydrophobic material in the pattern holes is stamped with a heating plate to melt it, and then cooled to obtain a fabric with an isolated hydrophobic pattern. During the stamping process, the insulating plate can be removed or not; when the insulating plate needs to be removed, the hydrophobic material in the pattern holes is first pressed with an unheated heating plate or other smooth plate to facilitate the removal of the insulating plate.

[0099] When the hydrophobic pattern to be formed is a continuous pattern, the mask used is a conductive mask such as an aluminum plate. During the electrostatic spraying process, the hydrophobic powder with static electricity will be concentrated and accumulated in the area between the pattern holes to form a hydrophobic material pattern; after the spraying is completed, the hydrophilic layer is covered on the top of the hydrophobic material pattern; then the conductive mask is energized to heat the hydrophobic material on the area between the hot stamping pattern holes to melt it, and then cooled to obtain a fabric with an isolated hydrophobic pattern.

[0100] Since the unidirectional water-conducting channel in the unidirectional moisture-conducting dressing substrate provided by the present application is a millimeter-level channel, it has high requirements for the dimensional accuracy of the hydrophobic pattern / hydrophilic pattern, and since conventional liquid spraying, printing and other processes are difficult to meet this technical effect, the inventor also uses electrostatic powder spraying to form a hydrophobic pattern on the hydrophilic layer, so that the pattern has good consistency, high precision, and the hydrophobic material is not easy to diffuse around. In addition, in order to further increase the bonding force between the hydrophobic material and the hydrophilic layer, the inventor uses a hot stamping process to fix the hydrophobic material on the hydrophilic layer, and solidifies the molten hydrophobic material to form an interlaced structure of the hydrophobic material and the hydrophilic material, so that the bonding force is strong and not easy to fall off, which is conducive to ensuring the stable unidirectional water-conducting ability of the fabric.

[0101] In the prior art, the main methods for arranging a hydrophobic pattern on one side of the hydrophilic layer of the fabric to achieve unidirectional moisture conduction of the dressing are: using a printing method or a liquid spraying method or a spraying method. Among them, the hydrophobic pattern obtained by the spraying method has poor consistency and insufficient stability of the unidirectional moisture conduction effect, which is difficult to promote and use. The existing printing method or spraying method both use a liquid spraying method, which makes it easy to control the size and shape of the printed pattern formed at the millimeter level due to the infiltration and diffusion of the liquid, especially the size of 1mm~3mm. During the printing process, it is very easy to cause the preset water guide channel to become smaller or even completely covered by the hydrophobic material due to the infiltration and diffusion of the liquid, resulting in the hydrophobic pattern actually being connected into one piece, affecting the unidirectional water conduction effect. Although the use of processes such as glue printing and electrostatic spinning can improve the infiltration and diffusion effects to a certain extent, the hydrophobic pattern formed has poor bonding with the hydrophilic layer, and it is easy to cause the hydrophobic pattern to fall off and wear due to friction, scraping, etc., which in turn affects the unidirectional water conduction effect. The glue printing also has the problem of high hardness of the hydrophobic pattern, which in turn affects people's touch.

[0102] In addition, the raw materials used in the printing process or the spraying, coating process and the electrostatic spinning process are relatively complex, and usually include additives such as solvents, fillers, flow agents, dispersants, defoamers, and even initiators, catalysts, and other ingredients. In order to better combine the hydrophobic material with the hydrophilic material, it may also be necessary to add a humidification process; and in order to clean the solvents and various additives used in the printing process or the spraying, coating process and the electrostatic spinning process to the human body, it is usually necessary to add cleaning, drying and other processes. It can be seen that the conventional printing process or the spraying, coating process and the electrostatic spinning process not only use complex hydrophobic materials, but also easily introduce components that affect the wound, and the process is complex and the consistency of the formed pattern is also poor.

[0103] In this regard, the inventor proposed a combined process of electrostatic powder spraying + hot stamping to obtain a unidirectional moisture-conducting fabric, and then etched the hydrophobic pattern surface of the unidirectional moisture-conducting dressing substrate to obtain a stable moisture-conducting unidirectional moisture-conducting dressing with a nano / micro structure with nano-protrusions / micro-protrusions on the surface. Since it uses hydrophobic polymer powder as a spraying raw material, it does not need to be configured into a composition, nor does it need to add solvents, flow agents, dispersants, defoaming agents and other additives. It has simple ingredients, few processing steps, and less impact on the body. It is especially suitable for wound dressings. In addition, it has high bonding strength and is not easy to fall off. There will be no obvious infiltration during the printing process, which affects the accuracy.

[0104] In some embodiments, the particle size of the powdered hydrophobic material is a powder that passes through a 50-mesh to 1000-mesh sieve, preferably a powder that passes through a 100-mesh to 1000-mesh sieve, so that the hydrophobic material formed can form a pattern with high precision under the action of static electricity, and can also melt quickly in the hot stamping process to increase the process speed.

[0105] In some embodiments, when the hydrophobic pattern is formed by electrostatic powder spraying and hot stamping processes, the molten hydrophobic material vertically penetrates into the hydrophilic layer and forms an interlaced structure with the material of the hydrophilic layer.

[0106] In a third aspect, the present application also provides the one-way moisture-conducting and anti-adhesion dressing described in the first aspect or the preparation method of the one-way moisture-conducting and anti-adhesion dressing described in the first aspect, and uses the one-way moisture-conducting and anti-adhesion dressing in the field of clothing.

[0107] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are 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 ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0108] Example 1

[0109] In this embodiment, polyurethane (TPU) with an average particle size of 500 mesh is used as the hydrophobic material (purchased from Covestro Bayer, Germany, model 150 / 225 polyurethane resin powder transparent raw material spray powder), which is (AB) n A block linear polymer, A is a polyester or polyether with a high molecular weight (1000-6000), B is a diol containing 2-12 straight-chain carbon atoms, the chemical structure between the AB segments is diisocyanate, the hydrophilic layer is pure cotton fabric (purchased from Xiyifang Company, the model is pure cotton white grey fabric), an aluminum plate with an array of circular holes with a diameter of 1.5 mm is used as a mask, and the spacing between the circular holes in the array is 1 mm. The specific preparation method is as follows:

[0110] S10, spreading the hydrophilic layer evenly on a grounded workbench, and pressing the mask onto the hydrophilic layer;

[0111] S20, using a sprayer (model Milepost series handheld electrostatic powder spraying system) to spray a hydrophobic material onto the mask, the spraying process parameters are: powder volume in the powder barrel: more than 50%; pressure of the powder barrel connecting pipe: 0.8MPa~1.0MPa; spraying powder volume pressure: 0.2MPa~0.25MPa; atomization pressure: 0.1MPa~0.15MPa; voltage: 68kV~70kV; spraying current: 25kV~30μA; distance between the spray gun and the workpiece: 15cm~20cm; spraying time: 5s~10s, to obtain a hydrophobic material pattern;

[0112] S30, taking a pressing plate with a smooth surface, pressing it on the mask, applying pressure so that the hydrophobic material in the hydrophobic material pattern is compressed, and then removing the pressing plate and the mask in sequence;

[0113] S40, pressing a heating plate of an external power supply onto the hydrophilic layer, turning on the power, controlling the heating temperature to 180° C. and the pressure to 0.35 MPa, heating for 15 minutes, turning off the power, and cooling;

[0114] S50 and DMF were used as etchants. The etchants were evenly applied on the hydrophobic pattern using a brush, and some honeycomb hydrophobic patterns were obtained by etching at 60°C for 10 minutes. After etching, the etchant DMF was washed off with ethanol, and then the dressing was placed at room temperature to dry for 24 hours, and finally a dressing substrate A was obtained;

[0115] An appropriate amount of vaseline was weighed and coated on the dressing substrate A so that the volume proportion of the oil layer in the dressing in the microstructure of the hydrophobic pattern surface was 100%, thereby obtaining dressing A.

[0116] Example 2

[0117] Compared with Example 1, the fat used in this example is lard to form a fat layer, and the remaining steps are the same as Example 1. The volume proportion of the fat layer in the microstructure of the hydrophobic pattern surface of the dressing is 100%, and dressing B is obtained.

[0118] Example 3

[0119] Compared with Example 1, the grease used in this embodiment is silicone grease to form a grease layer, and the remaining steps are the same as Example 1. The volume proportion of the grease layer in the microstructure of the hydrophobic pattern surface of the dressing is 100%, and dressing C is obtained.

[0120] Example 4

[0121] Compared with Example 1, the oil used in this example is paraffin wax to form an oil layer, so that the volume proportion of the oil layer in the microstructure of the hydrophobic pattern surface is 100%, thereby obtaining dressing D.

[0122] Example 5

[0123] Compared with Example 1, in this embodiment, an aluminum plate having an array of circular holes with a diameter of 1.5 mm is used as a mask, and the spacing between the circular holes in the array is 1.0 mm. The specific preparation method is as follows:

[0124] S10, place the workbench on which the aluminum plate is grounded;

[0125] S20, using a sprayer (model Milepost series handheld electrostatic powder spraying system) to spray a hydrophobic material onto the mask, the spraying process parameters are: powder volume in the powder barrel: more than 50%; pressure of the powder barrel connecting pipe: 0.8MPa~1.0MPa; spraying powder volume pressure: 0.2MPa~0.25MPa; atomization pressure: 0.1MPa~0.15MPa; voltage: 68kV~70kV; spraying current: 25μA~30μA; distance between the spray gun and the workpiece: 15cm~20cm; spraying time: 5s~10s, to obtain a hydrophobic material pattern;

[0126] S30, covering the surface of the aluminum plate with a hydrophilic layer, pressing a heating plate with an external power supply on the hydrophilic layer, turning on the power, controlling the heating temperature to 180° C. and the pressure to 0.35 MPa, heating for 5 minutes, turning off the power, and cooling;

[0127] S40 and DMF were used as etchants. The etchants were evenly applied on the hydrophobic pattern using a brush, and some honeycomb hydrophobic patterns were obtained by etching at 60°C for 10 minutes. After etching, the etchant DMF was washed off with ethanol, and then the dressing was placed at room temperature to dry for 24 hours, and finally the dressing substrate E was obtained;

[0128] The dressing substrate E is coated with vaseline to obtain a dressing E, in which the volume proportion of the oil layer in the microstructure of the hydrophobic pattern surface is 100%.

[0129] Example 6

[0130] Compared with Example 1, the diameter of the pattern holes of the mask used in this embodiment is 1.5 mm, and the spacing between the pattern holes is 2 mm; the remaining steps are the same as those in Example 1 to obtain a dressing substrate F;

[0131] The dressing substrate F is coated with vaseline to obtain a dressing F, in which the volume proportion of the oil layer in the microstructure of the hydrophobic pattern surface is 100%.

[0132] Example 7

[0133] Compared with Example 1, the hydrophobic material used in this example is a polypropylene powder with an average particle size of 500 mesh (purchased from Hengfa Plastic Chemical Co., Ltd., model number is high molecular weight PP polypropylene resin powder), which is a thermoplastic resin mainly prepared by polymerization of propylene CH2=CH-CH3. The remaining steps are the same as those in Example 1 to obtain a dressing substrate G;

[0134] The dressing substrate G is coated with vaseline to obtain a dressing G, in which the volume proportion of the oil layer in the microstructure of the hydrophobic pattern surface is 100%.

[0135] Example 8

[0136] Compared with Example 1, in S40 of this embodiment, the hot stamping temperature used is 160° C., the hot stamping time is 15 min, and the remaining steps are the same as those of Example 1, to obtain a dressing substrate H;

[0137] The dressing substrate H is coated with vaseline to obtain a dressing H, in which the volume proportion of the oil layer in the microstructure of the hydrophobic pattern surface is 100%.

[0138] Example 9

[0139] Compared with Example 1, in S40 of this embodiment, the hot stamping temperature used is 180° C., the hot stamping pressure is 0.60 MPa, the hot stamping time is 30 min, and the remaining steps are the same as those of Example 1, to obtain a dressing substrate I;

[0140] Vaseline is applied to the dressing substrate I to obtain a dressing I, in which the volume proportion of the oil layer in the microstructure of the hydrophobic pattern surface is 100%.

[0141] Comparative Example 1

[0142] Compared with Example 1, the step of forming a grease layer on the hydrophobic pattern was omitted in this comparative example, and the dressing substrate was used as a control sample.

[0143] Comparative Example 2

[0144] Compared with Example 1, the fat layer in this comparative example is formed by changing the weight of the applied vaseline to 150% so that the volume proportion of the fat layer in the microstructure of the hydrophobic pattern surface is 150%, thereby obtaining comparative dressing 2.

[0145] Comparative Example 3

[0146] Compared with Example 1, the fat layer in this comparative example is formed by changing the weight of the applied vaseline to 5% so that the volume proportion of the fat layer in the microstructure of the hydrophobic pattern surface is 5%, thereby obtaining comparative dressing 3.

[0147] Comparative Example 4

[0148] Compared with Example 1, the volume proportion of the oil layer in the microstructure of the hydrophobic pattern surface in the dressing in this comparative example is 25%, and the remaining steps are the same as in Example 1, comparative dressing 4.

[0149] Comparative Example 5

[0150] Compared with Example 1, step S50 is omitted in this comparative example (DMF is used as an etchant, and the etchant is evenly brushed on the hydrophobic pattern with a brush, and etching is performed at 60°C for 10 minutes to obtain some honeycomb structure hydrophobic patterns), and the remaining steps are the same as those in Example 1 to obtain a comparative dressing 5, in which the volume proportion of the oil layer in the microstructure of the hydrophobic pattern surface is 100%.

[0151] Comparative Example 6

[0152] Compared with Example 1, in this Example S40, the hot stamping temperature used is 140°C, the hot stamping time is 15 minutes, and the remaining steps are the same as Example 1, to obtain a comparative dressing 6, in which the volume proportion of the oil layer in the microstructure of the hydrophobic pattern surface is 100%.

[0153] Comparative Example 7

[0154] Compared with Example 1, in this Example S40, the hot stamping temperature used is 200° C., the hot stamping time is 15 minutes, and the remaining steps are the same as those in Example 1, to obtain a comparative dressing 7, in which the volume proportion of the oil layer in the microstructure of the hydrophobic pattern surface is 100%.

[0155] Comparative Example 8

[0156] Compared with Example 1, the hot stamping temperature used in this comparative example is 180°C, the hot stamping time is 30 minutes, the hot stamping pressure is 0.35 MPa, and the remaining steps are the same as those in Example 1, to obtain a comparative dressing 8, in which the volume proportion of the oil layer in the microstructure of the hydrophobic pattern surface is 100%.

[0157] Comparative Example 9

[0158] Compared with Example 1, this comparative example uses an aqueous solution of TPU as the hydrophobic coating, the concentration of TPU is 12.5%wt, and the solvent DMF is purchased from Inotech Company with a specification of ≥99.9%; and steps S30~S40 are omitted, and the remaining steps are the same as Example 1, to obtain a comparative dressing 9, in which the volume proportion of the oil layer in the microstructure of the hydrophobic pattern surface is 100%.

[0159] test:

[0160] (1) Dressing adhesion test

[0161] Take a number of ex vivo pig skins, drip 1 mL of fresh sheep blood on the surface of each pig skin, and then cover the sheep blood with the above-obtained dressings A to O respectively; place them at 25°C and 40% rh for 4 hours; use a dynamometer to perform peeling adhesion test at a peeling speed of 30 cm / min and a peeling angle of 90°, test each dressing three times, and take the average value.

[0162] (2) Peel strength test

[0163] The binding strength between the hydrophilic cotton layer and the hydrophobic polyurethane layer of the dressings A to O obtained above was tested respectively. The specific testing method was as follows: the polyurethane layer and the cotton layer were clamped by the upper and lower clamps of a tensile testing machine respectively, and then stretched at a rate of 5 cm / min, and then the maximum force value tested during the stretching process was recorded.

[0164] (3) Water contact angle test

[0165] The characterization was carried out using a contact angle tester, where a water droplet of about 5 μL was placed in contact with the hydrophilic pattern and the hydrophobic pattern side of the dressing from above, and the water contact angle when the droplet tended to be stable and no longer changed on the test surface was recorded as the static contact angle.

[0166] (4) One-way water conduction experiment

[0167] A water droplet 30 of about 40 μL is injected by a syringe pump 40 within 25 seconds to contact the hydrophobic pattern side of the dressing from below, and the absorption speed of the droplet is detected; the test structure is as follows Fig.10 shown.

[0168] After each unidirectional water conduction test, the dressing was fully dried, and then the next unidirectional water conduction test was carried out for 100 cycles. The unidirectional water conduction rate after 100 cycles was tested respectively. The unidirectional water conduction rate after 100 cycles was divided by the unidirectional water conduction rate measured in the first unidirectional water conduction test to obtain the unidirectional water conduction rate retention rate for 100 times.

[0169] The above-obtained dressings A to J, comparative dressings (hereinafter referred to as DB) 1 to 10, and commercially available oily dressings (control example) were tested for adhesion, peel strength, and unidirectional water conduction performance, respectively. The test results are shown in Table 1.

[0170] Table 1

[0171]

[0172] From Table 1, Figure 6It can be seen that the dressing provided in the present application forms a microstructure on the hydrophobic pattern and attaches a layer of grease, which can not only achieve unidirectional water conduction, but also has extremely low adhesion to the wound and high peel strength, which is conducive to accelerating the wound healing process. Compared with the dressings of Comparative Example 1, Comparative Example 4, and Control Example, the dressing obtained in Example 1 not only has lower adhesion, but also maintains better long-term unidirectional water conduction performance. It can be seen that the synergistic effect of the microstructure of the hydrophobic pattern and the grease layer in the dressing provided in the present application is more conducive to improving the performance of the dressing.

[0173] In addition, it can be seen from Table 1 that the unidirectional water conduction rate retention rate of the unidirectional dressing prepared by the electrostatic powder spraying combined with hot stamping method can still be maintained at more than 95% after 100 uses, while the unidirectional water conduction rate of the unidirectional dressing prepared by the electrostatic spinning method directly drops to 0 after 100 cycles. In fact, during the test, the unidirectional water conduction rate of the unidirectional dressing prepared by electrostatic spinning alone has dropped to an extremely low level in the third cycle, and dropped to 0 in the fourth cycle; and during its preparation, the temperature and pressure of hot stamping have a significant effect on the unidirectional water conduction performance and peel strength of the dressing. The unidirectional water conduction performance of the dressing without a grease layer has not decreased, but its stable water conduction performance has decreased to a certain extent during long-term use. Especially in the flowing wound exudate simulation liquid, the water conduction effect of the wound exudate simulation liquid of dressings with other structures and dressings with a low grease layer content is more significantly reduced, and it is difficult to maintain efficient unidirectional water conduction when the wound exudate continues to seep / flow. The reason may be that the wound exudate contains a large amount of salt, cell tissue, etc., which are easily blocked by the dressing after being absorbed by the dressing. In particular, the protein polymer in the wound exudate may have both hydrophilic and hydrophobic groups, which is more likely to cause the unidirectional water conduction ability of the existing dressing with micron-level unidirectional water conduction performance to decrease. The dressing provided by the present application pre-sets a layer of grease on the hydrophobic pattern, so that the wound exudate, whether it is hydrophilic or hydrophobic fluid, avoids the hydrophobic area and realizes unidirectional water conduction from the hydrophilic side. The spacing of the hydrophilic pattern is larger than the spacing of the existing hydrophilic pattern (usually micron-level), preferably about 2 mm, to avoid the decrease of unidirectional water conduction caused by its blockage.

[0174] In addition, the present application also discusses the effect of the dressing provided by the present application on promoting wound healing. The present application used Example 1 and commercially available oily gauze as dressings, respectively, to apply to circular full-thickness excision wounds on the body surface of adult mice, and observed the healing of the wounds for 11 days. The wound healing conditions and healing area were shown in Figure 1. Figure 7 , Figure 8 shown.

[0175] As can be seen from the figure, the dressing provided by the present application has a better effect on promoting wound healing, and the scar surface is smaller and less obvious after the wound heals. It can be seen that the dressing provided by the present application is more conducive to wound healing.

[0176] In addition, the inventors also studied the effects of different hot stamping temperatures (150°C, 160°C, 170°C, 180°C, and the rest of the preparation process is the same as in Example 1) and hot stamping times (2.5 min, 5 min, 7.5 min, 12.5 min, and the rest of the preparation process is the same as in Example 1) on the peeling force between the hydrophobic material layer and the hydrophilic layer on the dressing. The experimental results are as follows: Figure 8 As shown. As can be seen from Figure B, with the increase of hot stamping temperature, the binding force between the hydrophobic material layer and the hydrophilic layer gradually increases. At 180°C, the binding force between the hydrophobic material layer and the hydrophilic layer obtained by electrostatic powder spraying + hot stamping can reach 20N / cm; with the increase of hot stamping time, the binding force between the hydrophobic material layer and the hydrophilic layer also gradually increases. When the hot stamping time is 7.5min, the binding force between the hydrophobic material layer and the hydrophilic layer is higher than 15N / cm, and when the hot stamping time is 12.5min, the binding force between the hydrophobic material layer and the hydrophilic layer can reach more than 20N / cm. The inventor used electrospinning technology to prepare dressings at different spinning times (2.5min, 5min, 7.5min, 10min), as shown in FIG. Fig. 9 As shown in Figure A, the bonding force between the hydrophobic material layer and the hydrophilic layer is not only very small (less than 0.05 N / cm), but also does not increase significantly even if the spinning time increases.

[0177] In summary, the unidirectional moisture-conducting and anti-adhesion dressing provided in the present application and its preparation method and application can not only achieve excellent unidirectional liquid transport performance, but also ensure good unidirectional liquid transport performance when used for a long time.

[0178] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A one-way moisture-conducting and anti-adhesion dressing, characterized in that: A hydrophilic layer and a hydrophobic pattern arrayed on a first surface of the hydrophilic layer and a hydrophilic pattern arrayed between the hydrophobic patterns and consisting of the exposed hydrophilic layer and having a width of not less than 0.2 mm and a thickness of not more than 5 mm; The structure of the hydrophobic pattern is a nanostructure / microstructure formed by a plurality of nanoprotrusions / microprotrusions in an array on the surface of the hydrophobic pattern; a grease layer is adsorbed on the surface of the hydrophobic pattern; The volume proportion of the grease layer in the nanostructure / microstructure is not less than 50% and not more than 125%; wherein the volume proportion of the grease layer in the nanostructure / microstructure is the percentage of the volume occupied by the grease layer in the pores in the nanostructure / microstructure to the total volume of the pores in the nanostructure / microstructure.

2. The one-way moisture-conducting and anti-adhesion dressing according to claim 1, characterized in that: The 4h adhesion between the dressing and the skin tissue is not higher than 0.05N; wherein the detection method of the 4h adhesion between the dressing and the skin tissue is: 1 mL of fresh sheep blood was dripped onto the surface of pig skin, and then the test dressing was covered on the sheep blood; it was placed at 25°C and 40% rh for 4 hours; the peeling adhesion test was performed using a dynamometer at a peeling speed of 30 cm / min and a peeling angle of 90°.

3. The one-way moisture-conducting and anti-adhesion dressing according to claim 1, characterized in that: The spacing between adjacent nano-protrusions / micro-protrusions is 0.05 μm-100 μm, and the height of the nano-protrusions / micro-protrusions is 0.1 μm-100 μm.

4. The one-way moisture-conducting and anti-adhesion dressing according to claim 1, characterized in that: The hydrophobic pattern is a lipophilic hydrophobic material having an adsorption effect on grease. The lipophilic hydrophobic material is a hydrophobic macromolecular polymer. The adhesion performance of the hydrophobic macromolecular polymer to grease is greater than 100 kPa.

5. The one-way moisture-conducting and anti-adhesion dressing according to claim 1, characterized in that: The area ratio of the hydrophobic pattern on the first surface is not less than 44% or the area ratio of the hydrophilic pattern on the first surface is not more than 78%; and / or The hydrophobic pattern is a lipophilic hydrophobic material that has an adsorption effect on grease; the water contact angle of the hydrophobic material is 80° to 120°, and the oil contact angle of the hydrophobic material is not higher than 90°; and / or The hydrophobic pattern is a lipophilic hydrophobic material that has an adsorption effect on grease; the particle size of the powdered hydrophobic material is 50 mesh to 1000 mesh; and / or The thickness of the hydrophobic pattern is 0.1 mm to 2 mm.

6. The one-way moisture-conducting and anti-adhesion dressing according to claim 1, characterized in that: Part or all of the hydrophobic pattern is vertically immersed in the hydrophilic layer and forms an interlaced structure with the material of the hydrophilic layer; the hydrophobic pattern is an oleophilic hydrophobic material that has an adsorption effect on grease; the thickness of the hydrophobic material vertically immersed in the hydrophilic layer is not less than 0.1mm, and is lower than the thickness of the hydrophilic layer, and the width of the lateral diffusion on the hydrophilic layer is not more than 0.2mm.

7. The one-way moisture-conducting and anti-adhesion dressing according to claim 1, characterized in that: The distance between adjacent hydrophobic patterns is not less than 1 mm, or the distance between adjacent hydrophilic patterns is not less than 1.5 mm.

8. The method for preparing the unidirectional moisture-conducting and anti-adhesion dressing according to any one of claims 1 to 7, characterized in that: include: Providing a hydrophilic layer and a hydrophobic material in powder form; Using a mask having an array of hydrophobic patterns, an electrostatic powder spraying process is used to form an array of hydrophobic material patterns on the first surface of the hydrophilic layer; Using a hot stamping process to stamp the hydrophobic material pattern for 5 minutes to 15 minutes, cooling, and obtaining a hydrophobic pattern; Nano-protrusions / micro-protrusions are formed on the hydrophobic pattern by using an etching process, thereby obtaining a unidirectional moisture-conducting and anti-adhesion dressing.

9. The method for preparing the unidirectional moisture-conducting and anti-adhesion dressing according to any one of claims 1 to 7, characterized in that: include: providing a hydrophilic layer and a solution containing a hydrophobic material; Using a mask plate with an array of hydrophobic patterns, a liquid film of an array of hydrophobic material patterns is formed on the first surface of the hydrophilic layer by a spray coating process; The reticle mask is maintained to allow the material liquid film of the hydrophobic pattern to foam and solidify, thereby forming a hydrophobic material pattern with a porous structure, thereby obtaining a unidirectional moisture-conducting and anti-adhesion dressing.

10. The one-way moisture-conducting and anti-adhesion dressing according to any one of claims 1 to 7 or the one-way moisture-conducting and anti-adhesion dressing according to any one of claims 8 to 9 is prepared by using the one-way moisture-conducting and anti-adhesion dressing in the field of medical equipment or fabrics.

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