Medical dressing and its preparation method

Abstract

The present invention provides a medical repair dressing, a preparation method thereof and a medical patch. The preparation method of the medical repair dressing includes: under a catalyst and a first inert atmosphere, heating and reacting 4,4'-bis(dimethylhydroxysilyl) diphenyl ether with hexamethylene-1,6-diisocyanate to obtain an isocyanate group-terminated polyurethane; under a second inert atmosphere, subjecting the isocyanate group-terminated polyurethane to a capping reaction with 3-aminopropylmorpholine to obtain a morpholine-capped organosilicon-modified polyurethane; after mixing the morpholine-capped organosilicon-modified polyurethane with an organic solvent, performing spinning, drawing, web-forming and hot rolling in sequence to obtain the medical repair dressing. Using it as the backing layer of the medical patch can greatly improve the air permeability and water resistance of the medical patch, thereby effectively improving the use effect of the medical patch and prolonging its service life.

Description

Technical Field

[0001] The present invention relates to the field of medical dressing manufacturing, and more particularly, to a medical dressing and a preparation method thereof. Background Art

[0002] Medical dressings are plasters improved based on traditional cold compress methods. Generally, a medical dressing consists of a backing layer, a gel layer, and a non-stick layer. The backing layer is a non-woven fabric that allows air circulation, enabling the gel layer to adhere to it, being breathable but not permeable to water, and supporting heat dissipation; the gel layer is a water-soluble polymer framework structure containing water molecules and drugs, having thermosensitive penetration, membrane-controlled release effects, and moderate adhesiveness; the non-stick layer is a surface polyester protective film embossed film layer, which is peeled off before use, and the embossed surface can form patterns on the gel surface, which can not only ensure the skin respiration and metabolism of the application site, but also increase the skin contact area, making the application more secure and the absorption more complete.

[0003] The principle of medical dressings is as follows: the heat can be taken away by the vaporization of the water and natural cooling components contained in the polymer gel, achieving local cooling; the drug components are combined with the hydrogel, and through the hydration effect, the drug components can quickly penetrate the fat layer, penetrate into the subcutaneous tissue, reach the lesion site, act on the affected area, and achieve the effects of cold compress for relieving pain, transdermal absorption, and sustained-release drug delivery.

[0004] Medical dressings can cause local capillary vasoconstriction, reduce local congestion, reduce the sensitivity of nerve endings to relieve pain, cool down and reduce fever, reduce local blood flow, and prevent the spread of inflammation and suppuration. They can conduct and dissipate the heat in the body, increase heat dissipation, and reduce body temperature. Cold compress is applicable to early local soft tissue injuries, high fever patients, heatstroke patients, toothache and other people who need cold compress.

[0005] The problems existing in the existing medical dressings are that the heat dissipation effect of the backing layer is not ideal, and the water evaporation rate in the gel layer is too fast in a heat-accumulating environment, resulting in problems such as poor use effect and short use time of the medical dressing. Summary of the Invention

[0006] The main object of the present invention is to provide a medical repair dressing, a preparation method thereof, and a medical dressing, so as to solve the problems that the heat dissipation effect of the backing layer in the medical dressing is not ideal, and the water evaporation rate in the gel layer is too fast in a heat-accumulating environment, resulting in problems such as poor use effect and short use time of the medical dressing.

[0007] To achieve the above object, on the one hand, the present invention provides a preparation method of a medical repair dressing, and the preparation method of the medical repair dressing includes: under a catalyst and a first inert atmosphere, heating and reacting 4,4'-bis(dimethylhydroxysilyl) diphenyl ether with hexamethylene-1,6-diisocyanate to obtain an isocyanate group-terminated polyurethane; under a second inert atmosphere, carrying out a capping reaction of the isocyanate group-terminated polyurethane with 3-aminopropylmorpholine to obtain a morpholine-capped organosilicon-modified polyurethane; after mixing the morpholine-capped organosilicon-modified polyurethane with an organic solvent, carrying out spinning, drawing, web-forming and hot rolling in sequence to obtain a medical repair dressing.

[0008] Further, before the heating reaction process, the preparation method of the medical repair dressing further includes: dehydrating 4,4'-bis(dimethylhydroxysilyl) diphenyl ether; preferably, the dehydration process is a vacuum dehydration process carried out under the conditions of 100-120 °C and a vacuum degree less than 0.1 MPa.

[0009] Further, the catalyst is selected from organotin catalysts and / or bis(acetonitrile)palladium(II) chloride; preferably, the organotin catalyst is selected from dibutyltin dilaurate and / or stannous octoate; preferably, based on the total weight of 4,4'-bis(dimethylhydroxysilyl) diphenyl ether and hexamethylene-1,6-diisocyanate, the addition amount of the catalyst is 0.7-0.8 wt%.

[0010] Further, the temperature of the heating reaction is 60-80 °C.

[0011] Further, the molar ratio of 4,4'-bis(dimethylhydroxysilyl) diphenyl ether, hexamethylene-1,6-diisocyanate and 3-aminopropylmorpholine is 1:2:2.

[0012] Further, the organic solvent is a mixed solution of N,N-dimethylformamide and cyclohexane, preferably, the volume ratio of N,N-dimethylformamide to cyclohexane is (5-10):1.

[0013] Further, the temperature of the spinning process is 250-280 °C, and the spinning speed is 800-1200 m / min; the drawing speed of the drawing process is 500-800 m / min, and the drawing temperature is 130-160 °C; the temperature of the hot rolling process is 130-160 °C, and the hot rolling pressure is 2-5 MPa.

[0014] On the second aspect of the present application, there is also provided a medical repair dressing, and the medical repair dressing is prepared by using the preparation method provided by the present application; preferably, the pore size of the medical repair dressing is 0.5-2 μm.

[0015] The third aspect of the present application further provides a medical dressing, which includes a backing layer, a gel layer, and a non-stick layer arranged in a stacked manner. The backing layer is the medical repair dressing provided by the present application.

[0016] Applying the technical solution of the present invention, compared with the above-mentioned existing polyurethanes, the morpholine-capped organosilicon-modified polyurethane prepared in the present application is capped with a morpholine group and has better water-blocking performance. At the same time, due to the micropores on the surface of the medical repair dressing made by the above process, these micropores can allow gas to pass through, but will prevent water molecules from passing through. Therefore, the medical repair dressing provided by the present application can have good air permeability and excellent water-blocking performance at the same time. During application, using it as the backing layer of a medical dressing can greatly improve the air permeability and water-blocking performance of the medical dressing, thereby effectively improving the use effect of the medical dressing and extending its service life. Specific Embodiments

[0017] It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the embodiments.

[0018] As described in the background art, the heat dissipation effect of the backing layer in the existing medical dressings is not ideal, and the water evaporation rate in the gel layer is too fast in a heat-accumulating environment, resulting in problems such as poor use effect and short use time of the medical dressings. To solve the above technical problems, the present application provides a preparation method for a medical repair dressing. The preparation method of the medical repair dressing includes: under a catalyst and a first inert atmosphere, heating and reacting 4,4′-bis(dimethylhydroxysilyl)diphenyl ether with hexamethylene-1,6-diisocyanate to obtain an isocyanate group-terminated polyurethane; under a second inert atmosphere, subjecting the isocyanate group-terminated polyurethane to a capping reaction with 3-aminopropylmorpholine to obtain a morpholine-capped organosilicon-modified polyurethane; after mixing the morpholine-capped organosilicon-modified polyurethane with an organic solvent, performing spinning, drawing, web-forming, and hot rolling in sequence to obtain a medical repair dressing.

[0019] In the heating reaction, under a catalyst and an inert atmosphere, 4,4′-bis(dimethylhydroxysilyl)diphenyl ether reacts with hexamethylene-1,6-diisocyanate to form a urethane group, obtaining an isocyanate group-terminated polyurethane; the isocyanate groups at both ends of the polyurethane molecule then react with the amino group in the 3-aminopropylmorpholine molecule to form a urea group, obtaining a morpholine-capped organosilicon-modified polyurethane. Finally, it is made into a medical repair dressing through a spinning process.

[0020] Most of the existing polyurethane used in the backing layer is made of diisocyanate and polyether polyol, or is capped with a silane coupling agent. Compared with the existing polyurethane above, the morpholine-capped organosilicon-modified polyurethane prepared in this application is capped with a morpholine group and has better water-blocking performance. At the same time, due to the micropores on the surface of the medical repair dressing made by the above process, the micropores can allow gas to pass through, but will prevent water molecules from passing through. Therefore, the medical repair dressing provided in this application can have good air permeability and excellent water-blocking performance at the same time. During the application process, using it as the backing layer of a medical dressing can greatly improve the air permeability and water-blocking performance of the medical dressing, thereby effectively improving the use effect of the medical dressing and extending its service life.

[0021] Since hexamethylene-1,6-diisocyanate is prone to react with water, preferably, before the heating reaction process, the preparation method of the medical repair dressing further includes: dehydrating 4,4′-bis(dimethylhydroxysilyl)diphenyl ether. To further improve the dehydration effect, more preferably, the dehydration process is a vacuum dehydration process carried out at 100-120°C and a vacuum degree less than 0.1 MPa;

[0022] During the heating reaction process, the addition of a catalyst is beneficial to improving the reaction rate of the two. In a preferred embodiment, the catalyst is selected from organotin catalysts and / or bis(acetonitrile)palladium(II) chloride. Compared with other catalysts, the use of the above two catalysts is beneficial to further improving the reaction rate of the heating reaction, and at the same time can reduce the amount of catalyst used and save costs. More preferably, when the above catalyst is an organotin catalyst, the organotin catalyst includes but is not limited to dibutyltin dilaurate and / or stannous octoate.

[0023] To further improve the reaction activity, preferably, based on the total weight of 4,4′-bis(dimethylhydroxysilyl)diphenyl ether and hexamethylene-1,6-diisocyanate, the addition amount of the catalyst is 0.7-0.8 wt%. In addition, since when using bis(acetonitrile)palladium(II) chloride as the catalyst under the same dosage, the reaction time of the heating reaction can be shortened by more than one-fourth, therefore, considering shortening the reaction cycle, under the same conditions, bis(acetonitrile)palladium(II) chloride is more preferably used as the catalyst.

[0024] The temperature of the heating reaction only needs to meet the condition that the catalyst can reduce the activation of the reaction raw materials, and the specific temperature range is not limited. In a preferred embodiment, the temperature of the heating reaction is 60-80 °C. Compared with other temperature ranges, limiting the heating temperature within the above range is beneficial to further improving the reaction activity and reaction rate; at the same time, it can also improve the degree of full reaction of the reaction raw materials, thereby increasing the yield of the isocyanate group-terminated polyurethane and the subsequent prepared medical repair dressing.

[0025] The heating reaction and the capping reaction are continuous reactions, so there is no need to separate the product of the heating reaction (isocyanate group-terminated polyurethane) first. In a preferred embodiment, the molar ratio of 4,4′-bis(dimethylhydroxysilyl)diphenyl ether, hexamethylene-1,6-diisocyanate and 3-aminopropylmorpholine is 1:2:2. The dosage ratio of the above three raw materials includes but is not limited to the above range, and limiting it within the above range is beneficial to improving the utilization rate of the three raw materials, while increasing the yield of the morpholine-capped organosilicon-modified polyurethane and reducing the impurity content, which is thus beneficial to further improving the comprehensive properties such as water resistance and air permeability of the subsequent prepared medical repair dressing.

[0026] During the spinning process, the solvent can be selected from the types commonly used in the art. In a preferred embodiment, the organic solvent is a mixed solution of N,N-dimethylformamide and cyclohexane. Compared with other solvents, using a mixed solution of N,N-dimethylformamide and cyclohexane as the spinning solvent is beneficial to further improving the solubility of the morpholine-capped organosilicon-modified polyurethane in the solvent. At the same time, the viscosity of the mixed solution formed by the above solvent and the morpholine-capped organosilicon-modified polyurethane is relatively low, with good rheological properties, which is beneficial to improving its spinnability and the formability of the spinneret, and is beneficial to further improving the air permeability and flatness of the prepared medical repair dressing. To further improve the comprehensive properties such as air permeability and flatness of the prepared medical repair dressing, more preferably, the volume ratio of N,N-dimethylformamide to cyclohexane is (5-10):1.

[0027] The specific process of the spinning process can adopt the steps commonly used in the art. In a preferred embodiment, the temperature of the spinning process is 250-280 °C, and the spinning speed is 800-1200 m / min. Limiting the temperature and spinning speed of the spinning process within the above range is beneficial to further improving the mechanical strength, uniformity and density of the spinning, thereby being able to increase the service life of the subsequent prepared medical repair dressing.

[0028] The drawing process is used for further processing the spun fibers to further improve their tensile properties (such as tensile strength and elongation at break, etc.). In a preferred embodiment, the drawing speed of the drawing process is 500 - 800 m / min, and the drawing temperature is 130 - 160 °C. The drawing speed and drawing temperature of the drawing process include but are not limited to the above ranges, and limiting them within the above ranges is beneficial to further improving the tensile properties and uniformity of the spun fibers obtained.

[0029] The hot rolling step is a process of melting and forming a web with high - heat fiber filaments, and there will be perforations on the surface of the hot - rolled medical repair dressing. To further improve the air permeability of the medical repair dressing, preferably, the temperature of the hot rolling process is 130 - 160 °C, and the hot rolling pressure is 2 - 5 MPa.

[0030] The second aspect of the present application also provides a medical repair dressing, which is prepared by using the above - mentioned preparation method provided by the present application.

[0031] Most of the existing backing layers use polyurethanes made of diisocyanates and polyether polyols, or are capped with silane coupling agents. Compared with the above - mentioned existing polyurethanes, the morpholine - capped organosilicon - modified polyurethane prepared in the present application is capped with morpholine groups and has better hydrophobicity. At the same time, due to the micropores on the surface of the medical repair dressing made by the above - mentioned process, these micropores can allow gas to pass through, but will prevent water molecules from passing through. Therefore, the medical repair dressing provided by the present application can have both good air permeability and excellent water - blocking performance.

[0032] To further improve the air permeability of the medical repair dressing, preferably, the pore diameter of the medical repair dressing is 0.5 - 2 μm.

[0033] The third aspect of the present application also provides a medical patch, which includes a backing layer, a gel layer, and a release liner arranged in a stacked manner, and the backing layer is the above - mentioned medical repair dressing provided by the present application.

[0034] Compared with the defect that the non - woven fabric material of the backing layer of the existing medical patch cannot have both air - permeability and water - blocking performance, since the medical repair dressing provided by the present application has good air permeability and excellent water - blocking effect, the medical patch made with it as the backing layer can prevent the moisture of the gel layer from volatilizing through the backing layer while ensuring the heat dissipation of the gel layer, thereby effectively improving the use effect of the medical patch and extending its service life.

[0035] The following further describes the present application in detail with specific embodiments, and these embodiments should not be construed as limiting the scope claimed by the present application.

[0036] Example 1

[0037] A preparation method of a medical repair dressing includes:

[0038] (1) First, 31.8 g of 4,4′-bis(dimethylhydroxysilyl)diphenyl ether (0.1 mol) is dehydrated under vacuum at a temperature of 115°C and a vacuum degree of 0.05 MPa for 3 h. After cooling, 33.6 g of hexamethylene-1,6-diisocyanate (0.2 mol) and 0.5 g of dibutyltin dilaurate (accounting for 0.76% of the total weight of the reaction raw materials) are added, and the mixture is heated to 70°C under nitrogen protection and reacted for 6 h to obtain an isocyanate group-terminated polyurethane prepolymer;

[0039] (2) 28.8 g of 3-aminopropylmorpholine (0.2 mol) is added to the polyurethane prepolymer prepared in step (1), and the reaction is carried out at 25°C for 2 h under nitrogen protection to obtain a morpholine-terminated organosilicon-modified polyurethane;

[0040] (3) The organosilicon-modified polyurethane prepared in step (2) is dissolved in a mixed solvent of N,N-dimethylformamide / cyclohexane with a volume ratio of 5:1 to obtain a spinning dope;

[0041] (4) The spinning dope prepared in step (3) is subjected to spinning, drawing, web-forming, and hot rolling. The spinning temperature is 280°C, the spinning speed is 1000 m / min, the drawing speed is 600 m / min, the drawing temperature is 130°C, the hot rolling temperature is 160°C, and the hot rolling pressure is 3.5 MPa to obtain a medical repair dressing with a pore size of 0.5 - 2 μm.

[0042] Example 2

[0043] A preparation method of a medical repair dressing includes:

[0044] (1) First, 31.8 g of 4,4′-bis(dimethylhydroxysilyl)diphenyl ether (0.1 mol) is dehydrated under vacuum at a temperature of 115°C and a vacuum degree of 0.05 MPa for 3 h. After cooling, 33.6 g of hexamethylene-1,6-diisocyanate (0.2 mol) and 0.5 g of dibutyltin dilaurate (accounting for 0.76% of the total weight of the reaction raw materials) are added, and the mixture is heated to 80°C under nitrogen protection and reacted for 6 h to obtain an isocyanate group-terminated polyurethane prepolymer;

[0045] (2) 28.8 g of 3-aminopropylmorpholine is added to the polyurethane prepolymer prepared in step (1), and the reaction is carried out at 25°C for 2 h under nitrogen protection to obtain a morpholine-terminated organosilicon-modified polyurethane;

[0046] (3) The organosilicon-modified polyurethane prepared in step (2) is dissolved in a mixed solvent of N,N-dimethylformamide / cyclohexane with a volume ratio of 5:1 to obtain a spinning dope;

[0047] (4) The spinning dope prepared in step (3) is subjected to spinning, drawing, web-forming, and hot rolling. The spinning temperature is 280 °C, the spinning speed is 1000 m / min, the drawing speed is 600 m / min, the drawing temperature is 130 °C, the hot rolling temperature is 160 °C, and the hot rolling pressure is 4.25 MPa, to obtain a medical repair dressing with pore sizes ranging from 0.5 to 2 μm.

[0048] Example 3

[0049] The difference from Example 2 is that the catalyst is replaced with an equal amount of bis(acetonitrile)palladium(II) chloride, and other preparation operations are the same as those in Example 2. Using bis(acetonitrile)palladium(II) chloride as the catalyst can shorten the reaction time from 6 h to 4 h.

[0050] Comparative Example 1

[0051] The difference from Example 2 is that 3-aminopropylmorpholine is not added for capping, and other preparation operations are the same as those in Example 2.

[0052] Comparative Example 2

[0053] The difference from Example 2 is that polyether diol N220 is used to replace 4,4′-bis(dimethylhydroxysilyl)diphenyl ether, and other preparation operations are the same as those in Example 2.

[0054] Structure characterization:

[0055] Infrared spectra of the organosilicon-modified polyurethane prepared in Examples 1 - 3: 1640 cm -1 Characteristic absorption peak of the carbonyl group, 1570 cm -1 Characteristic absorption peak of the amide group.

[0056] The air permeability and water resistance of the medical repair dressings prepared in the above Examples 1 to 3, Comparative Example 1, and Comparative Example 2 were tested, and the test methods and results are as follows:

[0057] Standard GB / T 24218.15 - 2018 "Textiles - Test methods for nonwovens - Part 15: Determination of air permeability";

[0058] Standard GB / T 24218.16 - 2018 "Textiles - Test methods for nonwovens - Part 16: Determination of water resistance to penetration (hydrostatic pressure method)". The test results of the air permeability and water resistance of the medical repair dressings are shown in Table 1.

[0059] Table 1

[0060] <![CDATA[Permeability L / (m 2 .s)]]> <![CDATA[Hydrostatic pressure value, mmHg 2 O]]> Example 1 13.95 3548 Example 2 13.46 3563 Example 3 13.10 3557 Comparative Example 1 10.02 2816 Comparative Example 2 5.58 1724

[0061] From the data in the above table, it can be seen that the silicone-modified polyurethane prepared by the present invention has both excellent air permeability and water resistance. On the one hand, it is conducive to the dissipation of the heat absorbed by the gel layer, and on the other hand, it prevents water molecules from volatilizing through the backing layer, thus ensuring the use effect of the medical dressing.

[0062] It should be noted that the terms "first", "second", etc. in the description and claims of this application are used to distinguish similar objects and do not necessarily have to be used to describe a specific order or sequence. It should be understood that such terms can be interchanged under appropriate circumstances so that the embodiments of the present application described herein can be implemented in an order other than those described herein.

[0063] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A preparation method of a medical repair dressing, characterized in that, the preparation method of the medical repair dressing includes: under a catalyst and a first inert atmosphere, heating and reacting 4,4'-bis(dimethylhydroxysilyl)diphenyl ether with hexamethylene-1,6-diisocyanate to obtain an isocyanate group-terminated polyurethane; under a second inert atmosphere, subjecting the isocyanate group-terminated polyurethane to a capping reaction with 3-aminopropylmorpholine to obtain a morpholine-capped organosilicon-modified polyurethane; after mixing the morpholine-capped organosilicon-modified polyurethane with an organic solvent, performing spinning, drawing, web forming and hot rolling in sequence to obtain the medical repair dressing.

2. The preparation method of the medical repair dressing according to claim 1, characterized in that, before the heating reaction process, the preparation method of the medical repair dressing further includes: dehydrating the 4,4'-bis(dimethylhydroxysilyl)diphenyl ether.

3. The preparation method of the medical repair dressing according to claim 2, characterized in that, the dehydration process is a vacuum dehydration process carried out under the conditions of 100-120°C and a vacuum degree less than 0.1 MPa.

4. The preparation method of the medical repair dressing according to claim 1, characterized in that, the catalyst is selected from organotin catalysts and / or bis(acetonitrile)palladium(II) chloride.

5. The preparation method of the medical repair dressing according to claim 4, characterized in that, the organotin catalyst is selected from dibutyltin dilaurate and / or stannous octoate.

6. The preparation method of the medical repair dressing according to claim 4, characterized in that, based on the total weight of the 4,4'-bis(dimethylhydroxysilyl)diphenyl ether and the hexamethylene-1,6-diisocyanate, the addition amount of the catalyst is 0.7-0.8 wt%.

7. The preparation method of the medical repair dressing according to claim 1, characterized in that, the temperature of the heating reaction is 60-80°C.

8. The preparation method of the medical repair dressing according to claim 1, characterized in that, the molar ratio of the 4,4'-bis(dimethylhydroxysilyl)diphenyl ether, the hexamethylene-1,6-diisocyanate and the 3-aminopropylmorpholine is 1:2:

2.

9. The preparation method of the medical repair dressing according to claim 1, characterized in that, the organic solvent is a mixed solution of N,N-dimethylformamide and cyclohexane.

10. The preparation method of the medical repair dressing according to claim 9, characterized in that, the volume ratio of the N,N-dimethylformamide to the cyclohexane is (5-10):

1.

11. The preparation method of the medical repair dressing according to claim 1, characterized in that, the temperature of the spinning process is 250-280°C, and the spinning speed is 800-1200 m / min; the drawing speed of the drawing process is 500-800 m / min, and the drawing temperature is 130-160°C; the temperature of the hot rolling process is 130-160°C, and the hot rolling pressure is 2-5 MPa.

12. A medical repair dressing, characterized in that, The medical repair dressing is prepared by the preparation method described in any one of claims 1 to 11.

13. The medical repair dressing according to claim 12, wherein, the pore size of the medical repair dressing is 0.5 to 2 μm.

14. A medical patch, comprising a backing layer, a gel layer and a release layer which are stacked, wherein, the backing layer is the medical repair dressing described in claim 12 or 13.