Pressure-sensitive adhesive layer, polyurethane dressing containing pressure-sensitive adhesive layer and preparation method of polyurethane dressing

Abstract

The invention discloses a pressure-sensitive adhesive layer, a polyurethane dressing containing the pressure-sensitive adhesive layer and a preparation method of the pressure-sensitive adhesive layer and belongs to the field of polyurethane dressings, and the overlook plan of the pressure-sensitive adhesive layer comprises a plurality of closed patterns; the edge of the closed pattern is coated with a pressure-sensitive adhesive, and the inner area of the closed pattern is not coated with the pressure-sensitive adhesive. Through the structural design of the pressure-sensitive adhesive layer, a plurality of microstructure units with independent closed patterns form a reasonably distributed non-adhesive area and an adhesive area. When the polyurethane breathable film is applied to the polyurethane dressing, the polyurethane breathable film has proper adhesive force, and meanwhile, the functions of preventing bacterial infection of a wound and reducing the influence of a pressure-sensitive adhesive layer on the breathability and moisture penetrability of the polyurethane breathable film on the whole polyurethane dressing can be remarkably improved, so that the wound rehabilitation rate and the use comfort of a patient are improved, and the application prospect is wide.

Description

Technical Field

[0001] This application belongs to the field of polyurethane dressings, specifically relating to a pressure-sensitive adhesive layer, a polyurethane dressing containing a pressure-sensitive adhesive layer, and a method for preparing the same. Background Technology

[0002] Polyurethane dressings are medical dressings composed of an extremely thin, elastic polyurethane film. Their main structure includes a polyurethane film layer, a pressure-sensitive adhesive layer, and a release paper layer. The polyurethane film layer is a porous polyurethane material that allows oxygen and moisture vapor to pass through while blocking liquid water and bacteria. Moisture permeability is a key indicator; high-quality polyurethane dressings have high moisture permeability, effectively preventing maceration of the skin around the wound. However, existing polyurethane dressings have insufficient flexibility, breathability, and moisture permeability, failing to meet the long-term use needs of patients. Summary of the Invention

[0003] This application aims to at least partially address one of the technical problems in related technologies. Therefore, the purpose of this application is to provide a pressure-sensitive adhesive layer, a polyurethane dressing containing the pressure-sensitive adhesive layer, and a method for preparing the same. Through the structural design of the pressure-sensitive adhesive layer, several independently closed microstructural units form rationally distributed adhesive-free and adhesive-containing areas. When applied to polyurethane dressings, it exhibits suitable adhesion and significantly improves the overall function of the polyurethane dressing in preventing bacterial infection of wounds and reducing the permeability and moisture permeability of the polyurethane breathable membrane caused by the pressure-sensitive adhesive layer. This enhances the patient's wound healing rate and comfort, and has broad application prospects.

[0004] The first aspect of this application discloses a pressure-sensitive adhesive layer. According to an embodiment of this application, the top view of the pressure-sensitive adhesive layer includes a plurality of closed patterns; The edges of the closed pattern are coated with pressure-sensitive adhesive, while the interior area of ​​the closed pattern is not coated with pressure-sensitive adhesive.

[0005] The pressure-sensitive adhesive layer of the above embodiments of this application, through its structural design, forms a rationally distributed distribution of adhesive-free and adhesive-containing areas by several independently closed microstructural units. When applied to polyurethane dressings, it exhibits suitable adhesion and significantly improves the overall function of the polyurethane dressing in preventing wound bacterial infection and reducing the permeability and moisture permeability of the polyurethane breathable membrane caused by the pressure-sensitive adhesive layer. This enhances the patient's wound healing rate and comfort, and has broad application prospects.

[0006] In addition, the pressure-sensitive adhesive layer according to the above embodiments of this application may also have the following additional technical features: In some embodiments of this application, the connecting area formed by the edges of adjacent closed patterns is coated with pressure-sensitive adhesive; Alternatively, the connecting area formed by the edges of adjacent closed patterns is not coated with pressure-sensitive adhesive.

[0007] In some embodiments of this application, the shape of the closed pattern includes at least one of polygons and circles, wherein the polygons include regular polygons, and the regular polygons include at least one of equilateral triangles, regular quadrilaterals, regular pentagons, regular hexagons, regular heptagons, regular octagons, regular nonagons, regular decagons, regular unequal sides, regular dodecagons, regular thirteen-sided polygons, and regular fourteen-sided polygons.

[0008] In some embodiments of this application, the outer diameter of the regular polygon is 3~10mm; And / or, the inner diameter of the regular polygon is 1~9mm.

[0009] In some embodiments of this application, the side width of the closed pattern is 0.5~6mm.

[0010] In some embodiments of this application, the thickness of the pressure-sensitive adhesive coating area is 5-50 micrometers; And / or, the type of pressure-sensitive adhesive includes at least one of rubber-type pressure-sensitive adhesive, acrylic-type pressure-sensitive adhesive, and silicone-type pressure-sensitive adhesive.

[0011] The second aspect of this application discloses a polyurethane dressing containing a pressure-sensitive adhesive layer. According to an embodiment of this application, the polyurethane dressing containing a pressure-sensitive adhesive layer comprises a polyurethane film layer, the pressure-sensitive adhesive layer described in the first aspect, and a release layer, sequentially stacked. Thus, the polyurethane dressing possesses excellent flexibility, breathability, and moisture permeability.

[0012] In addition, the polyurethane dressing containing a pressure-sensitive adhesive layer according to the above embodiments of this application may also have the following additional technical features: In some embodiments of this application, the physicochemical properties of the polyurethane film include: The thickness of the polyurethane film is 15~100 micrometers; And / or, the moisture permeability of the polyurethane membrane is ≥2000 g / m³. 2 / 24h; And / or, the elongation of the polyurethane film is 50-300%; And / or, the pore size of the polyurethane film is 0.01~10 micrometers; And / or, the polyurethane film is transparent or partially transparent.

[0013] A third aspect of this application discloses a method for preparing a polyurethane dressing containing a pressure-sensitive adhesive layer as described in the second aspect above. According to an embodiment of this application, the method for preparing the polyurethane dressing includes the following steps: According to the preset shape of the closed pattern, pressure-sensitive adhesive is applied to the surface of the isolation layer using a mold and then dried to form a pressure-sensitive adhesive layer; The polyurethane film and the pressure-sensitive adhesive layer are laminated to obtain the polyurethane dressing with the pressure-sensitive adhesive layer.

[0014] The preparation method of the polyurethane dressing in the above embodiment of the present application is simple in operation, does not require additional specific equipment, and is suitable for industrial mass production.

[0015] The additional aspects and advantages of the present application will be partially given in the following description, partially become obvious from the following description, or be understood through the practice of the present application. Description of the Drawings

[0016] The above and / or additional aspects and advantages of the present application will become obvious and easy to understand from the description of the embodiments in conjunction with the following drawings, in which: Figure 1 When the shape of the closed pattern is a regular octagon, the top view plane of the pressure-sensitive adhesive layer Figure 1 ; Figure 1 In the figure: 1 - Connection area not coated with pressure-sensitive adhesive.

[0017] Figure 2 When the shape of the closed pattern is a regular octagon, the top view plane of the pressure-sensitive adhesive layer Figure 2 ; Figure 2 In the figure: 2 - Connection area coated with pressure-sensitive adhesive.

[0018] Figure 3 When the shape of the closed pattern is a regular hexagon, the top view plane of the pressure-sensitive adhesive layer Figure 1 .

[0019] Figure 4 When the shape of the closed pattern is a regular hexagon, the top view plane of the pressure-sensitive adhesive layer Figure 2 .

[0020] Figure 5 When the shape of the closed pattern is a regular dodecagon, the top view plane of the pressure-sensitive adhesive layer Figure 1 .

[0021] Figure 6 When the shape of the closed pattern is a regular dodecagon, the top view plane of the pressure-sensitive adhesive layer Figure 2 .

[0022] Figure 7 When the shape of the closed pattern is a regular dodecagon, the top view plane of the pressure-sensitive adhesive layer Figure 3 .

[0023] Figure 8 When the shape of the closed pattern is a circle, the top view plan of the pressure-sensitive adhesive layer.

[0024] Figure 9 The top view plan of the pressure-sensitive adhesive layer when the pressure-sensitive adhesive layer is rhombus and the voids are small in Comparative Example 1.

[0025] Figure 10 This is a top view of the pressure-sensitive adhesive layer in Comparative Example 2, where the layer is rhomboid and has large gaps.

[0026] Figure 11 This is a schematic diagram of the structure of a polyurethane dressing. Detailed Implementation

[0027] The embodiments of this application are described in detail below, and the embodiments described below with reference to the accompanying drawings are merely exemplary and intended to explain this application, and should not be construed as limiting this application.

[0028] Currently, to mitigate the impact of pressure-sensitive adhesive layers on the moisture permeability of polyurethane film dressings, existing polyurethane dressings primarily employ designs such as dot or corrugated patterns for the pressure-sensitive adhesive layer, or reduce the layer thickness. Some products also improve moisture permeability by mechanically perforating existing materials. However, these large pores allow bacteria to pass through, reducing wound protection. Furthermore, dot or corrugated patterns in the pressure-sensitive adhesive layer increase the risk of bacterial infection when the adhesive layers come into contact with air, and insufficient adhesion can easily lead to adhesive residue.

[0029] To solve the above problems, the technical solution provided in this application is as follows: The first aspect of this application discloses a pressure-sensitive adhesive layer. According to an embodiment of this application, the top view of the pressure-sensitive adhesive layer includes a plurality of closed patterns; The edges of the closed pattern are coated with pressure-sensitive adhesive, while the interior area of ​​the closed pattern is not coated with pressure-sensitive adhesive.

[0030] The pressure-sensitive adhesive layer of the above embodiments of this application, through its structural design, forms rationally distributed adhesive-free and adhesive-containing areas by several independently closed microstructural units. When applied to polyurethane dressings, it exhibits suitable adhesion and significantly improves the overall function of the polyurethane dressing in preventing wound bacterial infection and reducing the permeability and moisture permeability of the polyurethane breathable membrane caused by the pressure-sensitive adhesive layer. This enhances the patient's wound healing rate and comfort, and has broad application prospects. Specifically: The microstructural unit design with independent, closed patterns gives the adhesive layer better overall flexibility, making it easier to adapt to irregular surfaces such as joint movements and skin folds. It does not restrict movement after application, providing a comfortable "second skin" experience, making it particularly suitable for patients requiring long-term application. It greatly reduces pain and fear when changing dressings, avoids secondary skin damage, and improves patient compliance.

[0031] The independent, closed-pattern microstructure unit design ensures that the wound has no unprotected direct channel to the outside world, reducing the risk of bacterial infection and promoting wound healing.

[0032] In addition, the pressure-sensitive adhesive layer according to the above embodiments of this application may also have the following additional technical features: In some embodiments of this application, the connecting area formed by the edges of adjacent closed patterns is coated with pressure-sensitive adhesive; or, the connecting area formed by the edges of adjacent closed patterns is not coated with pressure-sensitive adhesive. Figure 1 and Figure 2 As shown, when the closed pattern is a regular octagon, the connecting area formed by adjacent regular octagons can be coated with pressure-sensitive adhesive or not. To maintain the advantages of breathability and product adhesion, the adhesive area can be increased; no adhesive increases breathability, while adhesive increases product adhesion.

[0033] In some embodiments of this application, the shape of the closed pattern includes at least one of polygons and circles, wherein the polygons include regular polygons, and the regular polygons include at least one of equilateral triangles, regular squares, regular pentagons, regular hexagons, regular heptagons, regular octagons, regular nonagons, regular decagons, regular unequal sides, regular dodecagons, regular thirteen-sided polygons, and regular fourteen-sided polygons. Preferably, as Figure 3 (The connection area was not coated with pressure-sensitive adhesive) Figure 4 (The connection area is coated with pressure-sensitive adhesive) Figure 5 (The connection area was not coated with pressure-sensitive adhesive) Figure 6 (The connection area is coated with pressure-sensitive adhesive) Figure 7 (The connection area was not coated with pressure-sensitive adhesive) and Figure 8 (As shown in the diagram, where the bonding area is not coated with pressure-sensitive adhesive), this application employs an adhesive layer with regular polygonal patterns, such as regular octagons, and their combinations, creating a reasonable distribution of adhesive-free and adhesive surfaces. This reduces the impact on the porous polyurethane membrane, providing an unobstructed direct escape path for water vapor (sweat, wound exudate evaporation), improving the product's moisture permeability, significantly reducing the risk of skin maceration, maintaining the healthy state of the skin around the wound, promoting wound healing, and reducing bacterial infection. Simultaneously, it significantly improves the stability of the dressing on low-exudate wounds, extends the wearing time, and reduces the frequency of replacement. Its design provides a softer and more reliable adhesion, reducing the risk of curling. Furthermore, the stable structure of the regular polygonal patterns and their combinations makes it more robust than some finer microstructures during roll-to-roll (R2R) production, less prone to damage or deformation during lamination, thus ensuring high yield and production consistency, and increasing product yield.

[0034] In some embodiments of this application, the outer diameter of the regular polygon is 3-10 mm, for example, it can be 3 mm, 5 mm, 7 mm, 10 mm or any range between the above values; and / or, the inner diameter of the regular polygon is 1-9 mm, for example, it can be 1 mm, 2 mm, 5 mm, 9 mm or any range between the above values. By reasonably limiting the outer and inner diameters of the regular polygon, this application helps to improve the bonding stability of the pressure-sensitive adhesive layer, thereby improving the overall flexibility, breathability, and moisture permeability of the polyurethane dressing.

[0035] In some embodiments of this application, the edge width of the closed pattern is 0.5~6mm, for example, it can be 0.5mm, 1mm, 3mm, 6mm or any of the above values, which is beneficial to improving the flexibility of the pressure-sensitive adhesive layer.

[0036] In some embodiments of this application, the thickness of the area coated with pressure-sensitive adhesive is 5-50 micrometers, for example, it can be 5 micrometers, 10 micrometers, 15 micrometers, 30 micrometers, 50 micrometers or any range between the above values; and / or, the type of pressure-sensitive adhesive includes at least one of rubber-type pressure-sensitive adhesive, acrylic-type pressure-sensitive adhesive and silicone-type pressure-sensitive adhesive, specifically, commercially available pressure-sensitive adhesives such as 3M 4952VHB, 3M 9750, etc. can be directly used.

[0037] A second aspect of this application discloses a polyurethane dressing containing a pressure-sensitive adhesive layer. According to embodiments of this application, such as... Figure 11 As shown, the polyurethane dressing containing the pressure-sensitive adhesive layer comprises a polyurethane film layer, the pressure-sensitive adhesive layer described in the first aspect, and an isolation layer, which are stacked sequentially. Therefore, this application improves the stability, adhesion, and sealing properties of the adhesive layer by designing a specially patterned adhesive layer, thereby improving the moisture permeability of the polyurethane film, reducing the risk of bacterial infection in wounds, and enhancing the comfort and safety of the dressing. This results in a polyurethane dressing that combines excellent flexibility, breathability, and moisture permeability.

[0038] In addition, the polyurethane dressing containing a pressure-sensitive adhesive layer according to the above embodiments of this application may also have the following additional technical features: In some embodiments of this application, the physicochemical properties of the polyurethane membrane include: the thickness of the polyurethane membrane is 15-100 micrometers, for example, it can be 15 micrometers, 20 micrometers, 45 micrometers, 60 micrometers, 70 micrometers, 100 micrometers or any range between the above values; and / or, the moisture permeability of the polyurethane membrane is ≥2000 g / m³. 2 / 24h, for example, can be 2500g / m 2 / 24h, 3000g / m 2 / 24h, 4000g / m 2 / 24h or any of the above values; and / or, the elongation of the polyurethane film is 50-300%, for example, 50%, 80%, 100%, 150%, 200%, 300%, or any of the above values; and / or, the pore size of the polyurethane film is 0.01-10 micrometers, for example, 0.1, 0.5, 2, 3, 6, 8, 10 micrometers, or any of the above values; and / or, the polyurethane film is transparent or partially transparent. Apart from this, there are no other special limitations on the polyurethane film in this application; commercially available products can be used directly, or it can be made in-house using existing manufacturing processes.

[0039] A third aspect of this application discloses a method for preparing a polyurethane dressing containing a pressure-sensitive adhesive layer as described in the second aspect above. According to an embodiment of this application, the method for preparing the polyurethane dressing includes the following steps: According to the preset shape of the closed pattern, pressure-sensitive adhesive is applied to the surface of the isolation layer using a mold and then dried to form a pressure-sensitive adhesive layer; The polyurethane film and the pressure-sensitive adhesive layer are bonded together to obtain the polyurethane dressing containing the pressure-sensitive adhesive layer.

[0040] The method for preparing polyurethane dressings according to the above embodiments of this application is simple to operate, requires no additional specific equipment, and is suitable for industrial mass production. Specifically, the actual operation may include the following steps: 1) Using a mold, uniformly coat the side of the release layer coated with silicone oil with a coating liquid containing medical pressure-sensitive adhesive; 2) Feed the release paper with textured pressure-sensitive adhesive layer into the drying tunnel, and dry it at a high temperature of 50-150°C to evaporate and remove the solvent in the pressure-sensitive adhesive, or use UV curing to obtain a stable dry adhesive; 3) Lay the polyurethane film with the adhesive side of the release paper; 4) Cut the rolled-up product into the required size or shape according to product requirements.

[0041] The embodiments of this application are described in detail below. It should be noted that the embodiments described below are exemplary and are only used to explain this application, and should not be construed as limiting this application. In addition, unless otherwise specified, all reagents used in the following embodiments are commercially available or can be synthesized according to the methods described herein or known methods. For reaction conditions not listed, they are also readily available to those skilled in the art.

[0042] Example 1 This embodiment provides a pressure-sensitive adhesive layer and a polyurethane dressing containing the pressure-sensitive adhesive layer. The polyurethane dressing includes a polyurethane film layer, a pressure-sensitive adhesive layer, and a release layer stacked sequentially. The polyurethane membrane is selected from a polyurethane breathable membrane prepared by a wet process, and its physicochemical properties include: a thickness of 20 micrometers and a moisture permeability of 4700 g / m³.2 The elongation rate is 160% over 24 hours, and the pore size of the polyurethane film is 0.1 micrometers, making it transparent. The isolation layer is a release film, selected from commercially available glassine release paper, with a thickness of 110 micrometers; The pressure-sensitive adhesive layer is made of medical-grade acrylic pressure-sensitive adhesive APA-11 produced by Lucky; its top view includes several closed patterns, the edges of which are coated with pressure-sensitive adhesive, and the inner areas of which are not coated with pressure-sensitive adhesive, as shown in Figure 3; the outer diameter of the regular polygon is 8 mm, the inner diameter of the regular polygon is 5 mm, the coating edge width of the regular hexagon is 3 mm, the three-dimensional structure of the edge is a frustum, and the thickness of the area coated with pressure-sensitive adhesive is 22 micrometers.

[0043] The preparation method of the above-mentioned polyurethane dressing includes the following steps: According to the preset shape of the closed pattern, the pressure-sensitive adhesive coating liquid is evenly coated on the side of the isolation layer that is coated with silicone oil using a mold; then it is sent into the drying tunnel, dried and evaporated at 100°C to remove the solvent in the pressure-sensitive adhesive and form a pressure-sensitive adhesive layer. The polyurethane film is bonded to the adhesive side away from the insulating layer to obtain a polyurethane dressing.

[0044] Example 2 This embodiment provides a pressure-sensitive adhesive layer and a polyurethane dressing containing the pressure-sensitive adhesive layer, differing from Embodiment 1 only in that: (1) The joint area formed by the edges of adjacent closed patterns in the pressure-sensitive adhesive layer is further reinforced with pressure-sensitive adhesive to increase the bonding strength, such as... Figure 4 As shown.

[0045] Example 3 This embodiment provides a pressure-sensitive adhesive layer and a polyurethane dressing containing the pressure-sensitive adhesive layer, differing from Embodiment 1 only in that: (1) The closed pattern in the pressure-sensitive adhesive layer is a regular octagon and the connecting area formed by the edges of adjacent closed patterns is not coated with pressure-sensitive adhesive, such as... Figure 1 As shown.

[0046] Example 4 This embodiment provides a pressure-sensitive adhesive layer and a polyurethane dressing containing the pressure-sensitive adhesive layer, differing from Embodiment 1 only in that: (1) The closed pattern in the pressure-sensitive adhesive layer is a regular octagon, and the connecting area formed by the edges of adjacent closed patterns is coated with pressure-sensitive adhesive, such as... Figure 2 As shown.

[0047] Example 5 This embodiment provides a pressure-sensitive adhesive layer and a polyurethane dressing containing the pressure-sensitive adhesive layer, differing from Embodiment 1 only in that: (1) The closed pattern in the pressure-sensitive adhesive layer is a regular dodecagon and the connecting area formed by the edges of adjacent closed patterns is not coated with pressure-sensitive adhesive, such as Figure 5 As shown.

[0048] Example 6 This embodiment provides a pressure-sensitive adhesive layer and a polyurethane dressing containing the pressure-sensitive adhesive layer, differing from Embodiment 1 only in that: (1) The closed pattern in the pressure-sensitive adhesive layer is a regular dodecagon, and the connecting area formed by the edges of adjacent closed patterns is coated with pressure-sensitive adhesive, such as... Figure 6 As shown.

[0049] Example 7 This embodiment provides a pressure-sensitive adhesive layer and a polyurethane dressing containing the pressure-sensitive adhesive layer, differing from Embodiment 1 only in that: (1) The closed pattern in the pressure-sensitive adhesive layer is a regular dodecagon, and the connecting area formed by the edges of adjacent closed patterns is coated with pressure-sensitive adhesive, such as... Figure 7 As shown.

[0050] Example 8 This embodiment provides a pressure-sensitive adhesive layer and a polyurethane dressing containing the pressure-sensitive adhesive layer, differing from Embodiment 1 only in that: (1) The closed pattern in the pressure-sensitive adhesive layer is circular in shape, and the connecting area formed by the edges of adjacent closed patterns is not coated with pressure-sensitive adhesive, such as... Figure 8 As shown.

[0051] Comparative Example 1 This embodiment provides a pressure-sensitive adhesive layer and a polyurethane dressing containing the pressure-sensitive adhesive layer, differing from Embodiment 1 only in that: (1) The pressure-sensitive adhesive layer is formed using existing pattern design methods, such as... Figure 9 As shown.

[0052] Comparative Example 2 This embodiment provides a pressure-sensitive adhesive layer and a polyurethane dressing containing the pressure-sensitive adhesive layer, differing from Embodiment 1 only in that: (1) The pressure-sensitive adhesive layer is formed using existing pattern design methods, such as... Figure 10 As shown.

[0053] Test case This test example demonstrates the performance testing of the polyurethane dressings obtained in the above embodiments and comparative examples.

[0054] Test method: 1) Air permeability test: The air permeability of the membrane is tested using a Gurley MODEL4340 air permeability meter.

[0055] 2) Moisture permeability test: The MOCON AQUATRAN Model 2 moisture permeability meter is used to test the moisture permeability of the membrane.

[0056] 3) Adhesion test: Shimadzu EZ-LX electronic universal testing machine was used to test at 180°C. 。 Peeling force.

[0057] The test results are shown in Table 1.

[0058] Table 1

[0059] As shown in Table 1, compared to Comparative Example 1 and Comparative Example 2, the polyurethane dressing provided in this application has better air permeability and moisture permeability, and also has suitable adhesion. This indicates that the polyurethane dressing provided in this application, by designing a pressure-sensitive adhesive layer with a special structural pattern, can improve the wound healing rate and user comfort of patients.

[0060] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0061] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A pressure-sensitive adhesive layer, characterized in that, The top view of the pressure-sensitive adhesive layer includes several closed patterns; The edges of the closed pattern are coated with pressure-sensitive adhesive, while the interior area of ​​the closed pattern is not coated with pressure-sensitive adhesive.

2. The pressure-sensitive adhesive layer according to claim 1, characterized in that, The connecting area formed by the edges of adjacent closed patterns is coated with pressure-sensitive adhesive; Alternatively, the connecting area formed by the edges of adjacent closed patterns is not coated with pressure-sensitive adhesive.

3. The pressure-sensitive adhesive layer according to claim 1, characterized in that, The shape of the closed pattern includes at least one of polygons and circles, the polygons include regular polygons, and the regular polygons include at least one of equilateral triangles, regular quadrilaterals, regular pentagons, regular hexagons, regular heptagons, regular octagons, regular nonagons, regular decagons, regular unequal sides, regular dodecagons, regular thirteen-sided polygons and regular fourteen-sided polygons.

4. The pressure-sensitive adhesive layer according to claim 3, characterized in that, The outer diameter of the regular polygon is 3~10mm; And / or, the inner diameter of the regular polygon is 1~9mm.

5. The pressure-sensitive adhesive layer according to claim 1 or 4, characterized in that, The width of the closed pattern is 0.5~6mm.

6. The pressure-sensitive adhesive layer according to claim 1, characterized in that, The thickness of the area coated with pressure-sensitive adhesive is 5-50 micrometers; And / or, the type of pressure-sensitive adhesive includes at least one of rubber-type pressure-sensitive adhesive, acrylic-type pressure-sensitive adhesive, and silicone-type pressure-sensitive adhesive.

7. A polyurethane dressing containing a pressure-sensitive adhesive layer, characterized in that, It includes a polyurethane film layer, a pressure-sensitive adhesive layer as described in any one of claims 1 to 6, and an isolation layer, which are stacked in sequence.

8. The polyurethane dressing containing a pressure-sensitive adhesive layer according to claim 7, characterized in that, The physicochemical properties of the polyurethane film include: The thickness of the polyurethane film is 15~100 micrometers; And / or, the moisture permeability of the polyurethane membrane is ≥2000 g / m³. 2 / 24h; And / or, the elongation of the polyurethane film is 50-300%; And / or, the pore size of the polyurethane film is 0.01~10 micrometers; And / or, the polyurethane film is transparent or partially transparent.

9. The polyurethane dressing containing a pressure-sensitive adhesive layer according to claim 7, characterized in that, The release layer includes at least one of release paper and release film.

10. A method for preparing a polyurethane dressing containing a pressure-sensitive adhesive layer according to any one of claims 7 to 9, characterized in that, The preparation method of the polyurethane dressing includes the following steps: According to the preset shape of the closed pattern, pressure-sensitive adhesive is applied to the surface of the isolation layer using a mold and then dried to form a pressure-sensitive adhesive layer; The polyurethane film and the pressure-sensitive adhesive layer are bonded together to obtain the polyurethane dressing containing the pressure-sensitive adhesive layer.

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