A highly breathable and moisture-permeable medical pad and its preparation process

Abstract

The application relates to the technical field of medical nursing products, in particular to a high-air-permeability and high-moisture-permeability medical pad and a preparation process thereof. The non-woven fabric is immersed in a tannic acid solution to obtain a hydrophilic non-woven fabric; the non-woven fabric is sequentially immersed in a dopamine buffer solution and a mercaptopropyl methyl dimethoxysilane to obtain a modified super-hydrophilic non-woven fabric. A high-water-absorption resin is obtained by adding acrylic acid, a sodium hydroxide solution, trimethylolpropane triacrylate, propylene-modified chitosan antibacterial material, potassium persulfate, sodium bisulfite and sodium dodecyl sulfate; and the high-water-absorption resin is laid and formed to obtain an absorption layer. The absorption layer, the modified super-hydrophilic non-woven fabric and the hydrophilic non-woven fabric are sequentially covered on a barrier layer, and are bonded by hot-melt glue hot pressing to obtain a high-air-permeability and high-moisture-permeability medical pad. The medical pad prepared by the application has high air permeability and moisture permeability and good antibacterial performance, and therefore has a wide application prospect in the technical field of medical nursing products.

Description

Technical Field

[0001] The present invention relates to the technical field of medical care products, in particular to a highly air-permeable and moisture-permeable medical pad and a preparation process thereof. Background Art

[0002] In modern healthcare, medical drapes are playing an irreplaceable and important role, demonstrating multi-dimensional modern value. From a patient experience perspective, medical drapes keep the skin dry and effectively reduce the incidence of skin diseases such as bedsores and eczema. This is undoubtedly a key factor in improving the quality of life, especially for patients who are bedridden for a long time. In medical care, drapes reduce the workload of medical staff, allowing them to devote more time and energy to direct patient care. At the same time, drapes effectively prevent liquid penetration, avoiding contamination of the bed and surrounding environment, reducing the risk of cross-infection, and creating a safer and more hygienic treatment environment for patients.

[0003] However, traditional medical sheeting has poor breathability, making patients prone to feeling stuffy and humid after prolonged use. This not only reduces patient comfort but can also lead to a range of skin problems. For example, a humid environment can soften the skin's stratum corneum, reducing its resistance and increasing the risk of skin conditions such as bedsores and eczema. Sheets with excellent breathability and moisture permeability can effectively drain sweat and moisture from the body, keeping the skin dry and comfortable, effectively reducing these problems and making treatment more comfortable for patients, facilitating recovery. Furthermore, hospitals are places where various pathogens are concentrated, making medical sheeting susceptible to contamination by microorganisms such as bacteria and fungi. If sheeting lacks effective antimicrobial properties, these microorganisms can flourish, increasing the risk of infection for patients. Antimicrobial sheeting, on the other hand, can inhibit the growth of bacteria and fungi, reducing the risk of cross-infection and providing a safer treatment environment for patients, playing a crucial role in controlling hospital-acquired infections.

[0004] In order to overcome the defects of the prior art, the present invention provides a highly breathable and moisture-permeable medical pad and a preparation process thereof. Summary of the Invention

[0005] The purpose of the present invention is to provide a highly breathable and moisture-permeable medical pad and a preparation process thereof, so as to solve the problems in the prior art.

[0006] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0007] A process for preparing a highly breathable and moisture-permeable medical pad comprises the following steps:

[0008] Step 1: adding tris(hydroxymethyl)aminomethane, 0.10-0.12 mol / L hydrochloric acid, and deionized water to obtain a buffer solution with a pH of 7.8-8.0; then adding tannic acid to the buffer solution to obtain a tannic acid solution; immersing the non-woven fabric in the tannic acid solution for 15-20 hours to obtain a hydrophilic non-woven fabric;

[0009] Step 2: dissolving dopamine in deionized water, then adding tris(hydroxymethylaminomethane) and tris(hydroxymethylaminomethane) hydrochloride to obtain a dopamine buffer solution with a pH of 8.5-8.7; immersing the non-woven fabric in the dopamine buffer solution for 10-15 hours to obtain a super-hydrophilic non-woven fabric; then immersing the super-hydrophilic non-woven fabric in mercaptopropylmethyldimethoxysilane, reacting at 90-95° C. for 50-70 minutes to obtain a modified super-hydrophilic non-woven fabric;

[0010] Step 3: acrylic acid and deionized water are mixed, and after thorough stirring, 48-50 wt% sodium hydroxide solution is added dropwise. After neutralization, trimethylolpropane triacrylate, propylene-modified chitosan antibacterial material, potassium persulfate, sodium bisulfite, and sodium lauryl sulfate are added. After stirring evenly, the temperature is raised to 50-60° C. and the reaction is carried out for 3-5 hours. After the reaction is completed, the colloid is crushed, dried, crushed, and sieved to obtain a super absorbent resin; the super absorbent resin is then laid out to form an absorption layer;

[0011] Step 4: Cover the absorbent layer, modified super-hydrophilic non-woven fabric, and hydrophilic non-woven fabric on the anti-seepage layer in sequence, and bond them with hot melt adhesive by hot pressing to obtain a highly breathable and moisture permeable medical pad.

[0012] More optimally, in step 1, in the tannic acid solution, the reaction mass ratio of tris(hydroxymethyl)aminomethane to tannic acid is 12:(5-6).

[0013] More optimally, in step 2, the mass volume ratio of dopamine and deionized water is (0.004-0.005):2.

[0014] More optimally, in step three, the contents of each component of the super absorbent resin are: by mass, 350-400 parts of acrylic acid, 470-500 parts of deionized water, 240-270 parts of sodium hydroxide solution, 3.5-4.0 parts of trimethylolpropane triacrylate, 3-5 parts of propylene-modified chitosan antibacterial material, 0.7-1.0 parts of potassium persulfate, 0.4-0.6 parts of sodium bisulfite, and 0.2-0.3 parts of sodium lauryl sulfate.

[0015] More optimally, the preparation process of propenyl-modified chitosan antibacterial material is as follows: chitosan and 5-chlorosalicylaldehyde are dissolved in dimethyl sulfoxide, and then 4A molecular sieves are added, stirred and reacted at 60-65°C for 10-15 hours. After the reaction is completed, the Schiff-alkalized chitosan is obtained by precipitation separation, washing, and freeze-drying; then the Schiff-alkalized chitosan, inhibitor methylhydroquinone, triethylamine and tetrahydrofuran are mixed, stirred at 65-75°C until dissolved, and then a tetrahydrofuran solution of acryloyl chloride is added dropwise, and the stirring reaction is continued for 12-14 hours. After the reaction is completed, the liquid is separated, washed, filtered, rotary evaporated, and recrystallized to obtain the propenyl-modified chitosan antibacterial material.

[0016] More optimally, when preparing Schiff-base chitosan, the reaction mass ratio of chitosan, 5-chlorosalicylaldehyde and 4A molecular sieve is 3:(1.7-2.0):0.7.

[0017] More optimally, when preparing the propylene-modified chitosan antibacterial material, the reaction mass ratio of Schiff-alkalized chitosan and acryloyl chloride is 1:(1.0-1.2).

[0018] More optimally, in step three, the laying and molding process parameters are: temperature of 25-35°C, pressure of 0.3-0.5MPa, and speed of 5-7m / min.

[0019] More optimally, in step 4, the hot pressing pressure is 2-3 kgf / m 2 The hot pressing temperature is divided into two stages: the first stage is heating at 60-70°C for 1-2 hours, and the second stage is heating at 100-150°C for 2-3 minutes; the anti-seepage layer is a breathable SMS non-woven fabric.

[0020] Beneficial effects of the present invention:

[0021] The application is characterized in that, in step one, the non-woven fabric is immersed in a tannic acid solution to obtain a hydrophilic non-woven fabric; in step two, the non-woven fabric is sequentially immersed in a dopamine buffer solution and a mercaptopropyl methyl dimethoxysilane to obtain a modified super-hydrophilic non-woven fabric; and the medical pad is designed to have the hydrophilic non-woven fabric as the uppermost layer, the modified super-hydrophilic non-woven fabric as the next layer, and an absorbent layer and a barrier layer as the lower layers. The design purpose of the structure is that when liquid contacts the pad, the hydrophilic layer on the surface can quickly capture the liquid, spread the liquid rapidly and adhere the liquid to the surface, and preliminarily guide the liquid into the inside of the nursing pad. Further, the super-hydrophilic layer in the inside has stronger hydrophilicity and can absorb the liquid transmitted from the hydrophilic layer at a faster speed. The strong capillary action of the super-hydrophilic layer can promote the liquid to spread rapidly in all directions, so that the absorbent material in the inside of the pad can be used more fully, the liquid is prevented from accumulating in a local area, and the overall absorption capacity is improved. In addition, since the liquid can quickly pass through the hydrophilic layer into the super-hydrophilic layer and spread out, the surface layer of the pad can recover to a dry state more quickly, the contact time of the liquid with the skin of a user is reduced, the risk of discomfort and infection caused by skin wetting is reduced, and the comfort of the user is improved.

[0022] The application is characterized in that, in step three, the Schiff base chitosan is obtained by adding chitosan, 5-chlorosalicylaldehyde and 4A molecular sieves; and the acryl-modified chitosan antibacterial material is prepared by using the Schiff base chitosan and acryloyl chloride as main raw materials. In the preparation process of the acryl-modified chitosan, the Schiff base chitosan is first formed, the C=N double bond in the Schiff base structure has a certain polarity, can interact with the components on the surface of the bacterial cell membrane, destroy the integrity of the cell membrane, cause the leakage of intracellular substances, affect the physiological functions of bacteria, and then play an antibacterial role. In addition, the introduction of the acryl group enhances the lipophilicity of the chitosan, the enhanced lipophilicity makes the modified chitosan more easily interact with the bacterial cell membrane, increases the affinity and penetration ability of the modified chitosan to the cell membrane, more effectively destroys the bacterial cell membrane, and improves the antibacterial effect. When the modified chitosan penetrates the cell membrane and enters the bacterial cells, the modified chitosan binds with biological macromolecules such as nucleic acids, interferes with the process of genetic information transmission and replication of bacteria, and may also bind with enzymes in the bacterial body, change the structure of the active center of the enzymes, affect the metabolic pathways of bacteria, and inhibit the growth and reproduction of bacteria.

[0023] A super absorbent resin is obtained by adding acrylic acid, deionized water, sodium hydroxide solution, trimethylolpropane triacrylate, propylene-modified chitosan antibacterial material, potassium persulfate, sodium bisulfite, and sodium lauryl sulfate. The super absorbent resin is laid and formed to form an absorption layer. The super absorbent resin prepared by the present invention has a network structure formed by the polymerization of acrylic acid, which can accommodate a large amount of water, allowing the medical pad to quickly absorb and lock in liquid several times its own weight, preventing it from leaking onto bed sheets or clothing, and keeping the patient's body and the surrounding environment dry. Secondly, by adding the propylene-modified chitosan antibacterial material, the super absorbent resin of the present invention also has good antibacterial properties.

[0024] Furthermore, the present invention adds excessive acrylic acid when preparing the super absorbent resin, so a certain amount of acrylic acid remains in the prepared absorption layer. The unreacted acrylic acid remaining in the absorption layer and the modified super hydrophilic nonwoven fabric contact each other during the first-stage hot pressing reaction, causing a mercapto-alkene initiation reaction, resulting in a multilayer structure with good crosslinking. In this step, a chemical reaction occurs between the absorption layer and the modified super hydrophilic nonwoven fabric, forming a chemical bond or a strong intermolecular force at the interface of the absorption layer and the modified super hydrophilic nonwoven fabric, causing the two layers of material to be tightly combined and difficult to separate or produce relative displacement, thereby improving the structural stability and durability of the entire medical pad. Moreover, the absorption layer and the modified super hydrophilic nonwoven fabric originally have certain water absorption capacity, and the chemical reaction can form a more abundant pore structure between the two, thereby improving the absorption rate and absorption capacity of liquids. Finally, the absorption layer, the modified super hydrophilic nonwoven fabric, and the hydrophilic nonwoven fabric are sequentially covered on the impermeable layer and bonded with hot melt adhesive under hot pressing to obtain a highly breathable and moisture permeable medical pad. The medical pad prepared by the present invention has high air and moisture permeability and good antibacterial properties, and therefore has broad application prospects in the technical field of medical care products. DETAILED DESCRIPTION

[0025] The following will provide a clear and complete description of the technical solutions of the present invention in conjunction with the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of them. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0026] Source of raw materials:

[0027] Chitosan, provided by Qingdao Bozhihuili Biotechnology Co., Ltd., with a deacetylation degree ≥90% and industrial grade specifications; 4A molecular sieve, provided by Sinopharm Chemical Reagent Co., Ltd., with a specification of 0.8mm; breathable SMS non-woven fabric, provided by Shandong Xingdi New Materials Co., Ltd., with PP as the main raw material and a gram weight of 30g; in terms of mass, one portion is 1g.

[0028] Example 1: Step one: a buffer solution with pH = 8 is prepared by adding trimethylolamine, 0.1 mol / L hydrochloric acid, and deionized water; then tannic acid is added to the buffer solution to obtain a tannic acid solution; non-woven fabric is immersed in the tannic acid solution for 20 h, and a hydrophilic non-woven fabric is obtained after the immersion; in the tannic acid solution, the mass ratio of trimethylolamine to tannic acid is 12:5.5;

[0029] Step two: dopamine is dissolved in deionized water, and then trimethylolamine and trimethylolamine hydrochloride are added to obtain a dopamine buffer solution with pH = 8.5; non-woven fabric is immersed in the dopamine buffer solution for 15 h to obtain super-hydrophilic non-woven fabric; the super-hydrophilic non-woven fabric is then immersed in mercaptopropyl methyl dimethoxy silane and reacted at 95°C for 70 min to obtain modified super-hydrophilic non-woven fabric; the mass-volume ratio of dopamine to deionized water is 0.005:2;

[0030] Step three: chitosan and 5-chlorosalicylaldehyde are dissolved in dimethyl sulfoxide, and then 4A molecular sieves are added; the mixture is stirred at 65°C for 15 h; after the reaction, the product is separated by precipitation, washed, and freeze-dried to obtain Schiff base chitosan; then Schiff base chitosan, polymerization inhibitor methylhydroquinone, triethylamine, and tetrahydrofuran are mixed and stirred at 75°C until dissolved; acryloyl chloride in tetrahydrofuran is then added dropwise, and the mixture is continuously stirred for 14 h; after the reaction, the product is separated by liquid-liquid extraction, washed, filtered, rotary evaporated, and recrystallized to obtain acryl-modified chitosan antibacterial material; in the preparation of Schiff base chitosan, the mass ratio of chitosan, 5-chlorosalicylaldehyde, and 4A molecular sieves is 3:1.8:0.7; in the preparation of acryl-modified chitosan antibacterial material, the mass ratio of Schiff base chitosan to acryloyl chloride is 1:1.1;

[0031] 350 g of acrylic acid and 470 g of deionized water are mixed, and after thorough stirring, 240 g of 50 wt% sodium hydroxide solution is added dropwise; after neutralization, 3.5 g of trimethylolpropane triacrylate, 5 g of acryl-modified chitosan antibacterial material, 0.7 g of potassium persulfate, 0.4 g of sodium bisulfite, and 0.2 g of sodium dodecyl sulfate are added; the mixture is stirred uniformly and then heated to 60°C for 5 h; after the reaction, the product is broken by colloid, dried, crushed, and sieved to obtain a superabsorbent resin; the superabsorbent resin is then laid and shaped to obtain an absorption layer; the laying and shaping process parameters are: temperature 35°C, pressure 0.5 MPa, and speed 7 m / min;

[0032] Step four: the absorption layer, modified super-hydrophilic non-woven fabric, and hydrophilic non-woven fabric are sequentially covered on the breathable SMS non-woven fabric, and then hot-melt adhesive is used for hot-pressing and bonding to obtain a high-breathability and high-moisture-permeability medical pad; the hot-pressing pressure is 3 kgf / m 2The hot pressing temperature is divided into two stages: the first stage is heating at 70℃ for 2h, and the second stage is heating at 150℃ for 3min.

[0033] Example 2: Step 1: A buffer solution with a pH of 8 is obtained by adding tris(hydroxymethyl)aminomethane, 0.1 mol / L hydrochloric acid, and deionized water; tannic acid is then added to the buffer solution to obtain a tannic acid solution; a non-woven fabric is immersed in the tannic acid solution for 17 hours, and a hydrophilic non-woven fabric is obtained after the immersion is completed; in the tannic acid solution, the reaction mass ratio of tris(hydroxymethyl)aminomethane to tannic acid is 12:5.5;

[0034] Step 2: dissolving dopamine in deionized water, then adding tris(hydroxymethylaminomethane) and tris(hydroxymethylaminomethane) hydrochloride to obtain a dopamine buffer solution with a pH of 8.5; immersing the non-woven fabric in the dopamine buffer solution for 12 hours to obtain a super-hydrophilic non-woven fabric; then immersing the super-hydrophilic non-woven fabric in mercaptopropylmethyldimethoxysilane and reacting at 92° C. for 60 minutes to obtain a modified super-hydrophilic non-woven fabric; the mass volume ratio of dopamine to deionized water is 0.005:2;

[0035] Step 3: dissolve chitosan and 5-chlorosalicylaldehyde in dimethyl sulfoxide, add 4A molecular sieves, stir and react at 62°C for 13 hours, and after the reaction is completed, separate by precipitation, wash, and freeze-dry to obtain Schiff-alkalized chitosan; then mix the Schiff-alkalized chitosan, inhibitor methylhydroquinone, triethylamine and tetrahydrofuran, stir at 70°C until dissolved, and then add a tetrahydrofuran solution of acryloyl chloride dropwise, continue stirring and reacting for 13 hours, and after the reaction is completed, separate, wash, filter, rotary evaporate, and recrystallize to obtain a propenyl-modified chitosan antibacterial material; when preparing Schiff-alkalized chitosan, the reaction mass ratio of chitosan, 5-chlorosalicylaldehyde and 4A molecular sieve is 3:1.8:0.7; when preparing propenyl-modified chitosan antibacterial material, the reaction mass ratio of Schiff-alkalized chitosan and acryloyl chloride is 1:1.1;

[0036] 350g of acrylic acid and 470g of deionized water were mixed, and after thorough stirring, 240g of 49wt% sodium hydroxide solution was added dropwise. After neutralization, 3.5g of trimethylolpropane triacrylate, 5g of propylene-modified chitosan antibacterial material, 0.7g of potassium persulfate, 0.4g of sodium bisulfite, and 0.2g of sodium lauryl sulfate were added. After stirring evenly, the mixture was heated to 55°C and reacted for 4h. After the reaction, the colloid was crushed, dried, pulverized, and sieved to obtain a super absorbent resin. The super absorbent resin was then laid and formed to obtain an absorption layer. The laying and forming process parameters were: temperature 30°C, pressure 0.4MPa, and speed 6m / min.

[0037] Step 4: Cover the absorbent layer, modified super hydrophilic non-woven fabric, and hydrophilic non-woven fabric on the breathable SMS non-woven fabric in sequence, and bond them with hot melt adhesive to obtain a highly breathable and moisture permeable medical pad; the hot pressing pressure is 2.5 kgf / m 2 The hot pressing temperature is divided into two stages: the first stage is heating at 65°C for 1.5h, and the second stage is heating at 120°C for 2.5min.

[0038] Example 3: Step 1: A buffer solution with a pH of 8 is obtained by adding tris(hydroxymethyl)aminomethane, 0.1 mol / L hydrochloric acid, and deionized water; tannic acid is then added to the buffer solution to obtain a tannic acid solution; a non-woven fabric is immersed in the tannic acid solution for 15 hours, and a hydrophilic non-woven fabric is obtained after the immersion is completed; in the tannic acid solution, the reaction mass ratio of tris(hydroxymethyl)aminomethane to tannic acid is 12:5.5;

[0039] Step 2: dissolving dopamine in deionized water, then adding tris(hydroxymethylaminomethane) and tris(hydroxymethylaminomethane) hydrochloride to obtain a dopamine buffer solution with a pH of 8.5; immersing the non-woven fabric in the dopamine buffer solution for 10 hours to obtain a super-hydrophilic non-woven fabric; then immersing the super-hydrophilic non-woven fabric in mercaptopropylmethyldimethoxysilane and reacting at 90° C. for 50 minutes to obtain a modified super-hydrophilic non-woven fabric; the mass volume ratio of dopamine to deionized water is 0.005:2;

[0040] Step 3: dissolving chitosan and 5-chlorosalicylaldehyde in dimethyl sulfoxide, adding 4A molecular sieves, stirring and reacting at 60°C for 10 hours, separating by precipitation, washing, and freeze-drying after the reaction is completed to obtain Schiff-alkalized chitosan; then mixing Schiff-alkalized chitosan, inhibitor methylhydroquinone, triethylamine and tetrahydrofuran, stirring at 65°C until dissolved, adding dropwise a tetrahydrofuran solution of acryloyl chloride, and continuing to stir and react for 12 hours. After the reaction is completed, separating, washing, filtering, rotary evaporation, and recrystallization are performed to obtain a propenyl-modified chitosan antibacterial material; when preparing Schiff-alkalized chitosan, the reaction mass ratio of chitosan, 5-chlorosalicylaldehyde and 4A molecular sieves is 3:1.8:0.7; when preparing a propenyl-modified chitosan antibacterial material, the reaction mass ratio of Schiff-alkalized chitosan and acryloyl chloride is 1:1.1;

[0041] 350g of acrylic acid and 470g of deionized water were mixed, and after thorough stirring, 240g of 48wt% sodium hydroxide solution was added dropwise. After neutralization, 3.5g of trimethylolpropane triacrylate, 5g of propylene-modified chitosan antibacterial material, 0.7g of potassium persulfate, 0.4g of sodium bisulfite, and 0.2g of sodium lauryl sulfate were added. After stirring evenly, the mixture was heated to 50°C and reacted for 3h. After the reaction, the colloid was crushed, dried, pulverized, and sieved to obtain a super absorbent resin. The super absorbent resin was then laid and formed to obtain an absorption layer. The laying and forming process parameters were: temperature 25°C, pressure 0.3MPa, and speed 5m / min.

[0042] Step 4: Cover the absorbent layer, modified super hydrophilic non-woven fabric, and hydrophilic non-woven fabric on the breathable SMS non-woven fabric in sequence, and bond them with hot melt adhesive to obtain a highly breathable and moisture permeable medical pad; the hot pressing pressure is 2 kgf / m 2 The hot pressing temperature is divided into two stages: the first stage is heating at 60℃ for 1h, and the second stage is heating at 100℃ for 2min.

[0043] Comparative Example 1: The propylene-modified chitosan antibacterial material was removed, and the rest was the same as Example 1, and the specific steps were as follows: Step 1: A buffer solution with a pH of 8 was obtained by adding tris(hydroxymethylaminomethane), 0.1 mol / L hydrochloric acid, and deionized water; tannic acid was then added to the buffer solution to obtain a tannic acid solution; the non-woven fabric was immersed in the tannic acid solution for 20 hours, and a hydrophilic non-woven fabric was obtained after the immersion; in the tannic acid solution, the reaction mass ratio of tris(hydroxymethylaminomethane) and tannic acid was 12:5.5;

[0044] Step 2: dissolving dopamine in deionized water, then adding tris(hydroxymethylaminomethane) and tris(hydroxymethylaminomethane) hydrochloride to obtain a dopamine buffer solution with a pH of 8.5; immersing the non-woven fabric in the dopamine buffer solution for 15 hours to obtain a super-hydrophilic non-woven fabric; then immersing the super-hydrophilic non-woven fabric in mercaptopropylmethyldimethoxysilane and reacting at 95° C. for 70 minutes to obtain a modified super-hydrophilic non-woven fabric; the mass volume ratio of dopamine to deionized water is 0.005:2;

[0045] Step 3: 350g of acrylic acid and 470g of deionized water were mixed, and after thorough stirring, 240g of 50wt% sodium hydroxide solution was added dropwise. After neutralization, 3.5g of trimethylolpropane triacrylate, 0.7g of potassium persulfate, 0.4g of sodium bisulfite, and 0.2g of sodium lauryl sulfate were added. After stirring evenly, the temperature was raised to 60°C and reacted for 5h. After the reaction, the colloid was crushed, dried, crushed, and sieved to obtain a super absorbent resin; the super absorbent resin was then laid and formed to obtain an absorption layer; the laying and forming process parameters were: temperature 35°C, pressure 0.5MPa, and speed 7m / min;

[0046] Step 4: Cover the absorbent layer, modified super hydrophilic non-woven fabric, and hydrophilic non-woven fabric on the breathable SMS non-woven fabric in sequence, and bond them with hot melt adhesive by hot pressing to obtain a highly breathable and moisture permeable medical pad; the hot pressing pressure is 3kgf / m 2 The hot pressing temperature is divided into two stages: the first stage is heating at 70℃ for 2h, and the second stage is heating at 150℃ for 3min.

[0047] Comparative Example 2: The modified super-hydrophilic non-woven fabric was removed, and the rest was the same as in Example 1, and the specific steps were as follows: Step 1: a buffer solution with a pH of 8 was obtained by adding tris(hydroxymethylaminomethane), 0.1 mol / L hydrochloric acid, and deionized water; tannic acid was then added to the buffer solution to obtain a tannic acid solution; the non-woven fabric was immersed in the tannic acid solution for 20 hours, and a hydrophilic non-woven fabric was obtained after the immersion; in the tannic acid solution, the reaction mass ratio of tris(hydroxymethylaminomethane) and tannic acid was 12:5.5;

[0048] Step 2: dissolving chitosan and 5-chlorosalicylaldehyde in dimethyl sulfoxide, adding 4A molecular sieves, stirring and reacting at 65°C for 15 hours, separating by precipitation, washing, and freeze-drying after the reaction is completed to obtain Schiff-alkalized chitosan; then mixing Schiff-alkalized chitosan, inhibitor methylhydroquinone, triethylamine and tetrahydrofuran, stirring at 75°C until dissolved, adding dropwise a tetrahydrofuran solution of acryloyl chloride, and continuing to stir and react for 14 hours. After the reaction is completed, separating, washing, filtering, rotary evaporation, and recrystallization are performed to obtain a propenyl-modified chitosan antibacterial material; when preparing Schiff-alkalized chitosan, the reaction mass ratio of chitosan, 5-chlorosalicylaldehyde and 4A molecular sieves is 3:1.8:0.7; when preparing a propenyl-modified chitosan antibacterial material, the reaction mass ratio of Schiff-alkalized chitosan and acryloyl chloride is 1:1.1;

[0049] 350g of acrylic acid and 470g of deionized water were mixed, and after thorough stirring, 240g of 50wt% sodium hydroxide solution was added dropwise. After neutralization, 3.5g of trimethylolpropane triacrylate, 5g of propylene-modified chitosan antibacterial material, 0.7g of potassium persulfate, 0.4g of sodium bisulfite, and 0.2g of sodium lauryl sulfate were added. After stirring evenly, the mixture was heated to 60°C and reacted for 5h. After the reaction, the colloid was crushed, dried, pulverized, and sieved to obtain a super absorbent resin. The super absorbent resin was then laid and formed to obtain an absorption layer. The laying and forming process parameters were: temperature 35°C, pressure 0.5MPa, and speed 7m / min.

[0050] Step 3: Cover the absorbent layer and hydrophilic non-woven fabric on the breathable SMS non-woven fabric in sequence, and heat-press and bond them with hot melt adhesive to obtain a highly breathable and moisture-permeable medical pad; the hot pressing pressure is 3kgf / m 2 The hot pressing temperature is divided into two stages: the first stage is heating at 70℃ for 2h, and the second stage is heating at 150℃ for 3min.

[0051] Comparative Example 3: The modified super-hydrophilic non-woven fabric and the hydrophilic non-woven fabric were replaced with ordinary non-woven fabrics. The rest was the same as in Example 1, and the specific steps were as follows: Step 1: Chitosan and 5-chlorosalicylaldehyde were dissolved in dimethyl sulfoxide, and then 4A molecular sieves were added, stirred and reacted at 65 ° C for 15 h. After the reaction was completed, the Schiff alkaline chitosan was obtained by precipitation separation, washing, and freeze-drying; the Schiff alkaline chitosan, the inhibitor methylhydroquinone, triethylamine and tetrahydrofuran were mixed, and the mixture was stirred at 75 ° C for 15 h. ℃ and stirred until dissolved, then added dropwise a tetrahydrofuran solution of acryloyl chloride, and continued to stir and react for 14 hours. After the reaction, the mixture was separated, washed, filtered, rotary evaporated, and recrystallized to obtain an acryloyl-modified chitosan antibacterial material. When preparing Schiff-base chitosan, the reaction mass ratio of chitosan, 5-chlorosalicylaldehyde, and 4A molecular sieve was 3:1.8:0.7; when preparing acryloyl-modified chitosan antibacterial material, the reaction mass ratio of Schiff-base chitosan and acryloyl chloride was 1:1.1.

[0052] 350g of acrylic acid and 470g of deionized water were mixed, and after thorough stirring, 240g of 50wt% sodium hydroxide solution was added dropwise. After neutralization, 3.5g of trimethylolpropane triacrylate, 5g of propylene-modified chitosan antibacterial material, 0.7g of potassium persulfate, 0.4g of sodium bisulfite, and 0.2g of sodium lauryl sulfate were added. After stirring evenly, the mixture was heated to 60°C and reacted for 5h. After the reaction, the colloid was crushed, dried, pulverized, and sieved to obtain a super absorbent resin. The super absorbent resin was then laid and formed to obtain an absorption layer. The laying and forming process parameters were: temperature 35°C, pressure 0.5MPa, and speed 7m / min.

[0053] Step 2: Cover the absorbent layer and two layers of non-woven fabric on the breathable SMS non-woven fabric in sequence, and heat-press and bond them with hot melt adhesive to obtain a highly breathable and moisture-permeable medical pad; the hot pressing pressure is 3kgf / m 2 The hot pressing temperature is divided into two stages: the first stage is heating at 70℃ for 2h, and the second stage is heating at 150℃ for 3min.

[0054] Detection test:

[0055] Antibacterial rate test: The finished pad sheet prepared by the present invention is used as a sample, and the antibacterial rate of the sample against Escherichia coli is tested according to GB 15979-2002 standard.

[0056] Absorption speed test: The finished pad prepared by the present invention is used as a sample. The sample is placed in a beaker filled with 50 mL of deionized water and a magnetic stirrer is added. The timer starts after the sample is placed. After the sample absorbs the deionized water, the vortex on the middle liquid surface begins to disappear. When the vortex disappears and the liquid surface reaches a horizontal level, it is the end point. The time required to reach the end point is measured.

[0057] Water absorption test: The finished pad prepared by the present invention is used as a sample. After the sample is completely soaked and emptied, the mass of the sample before and after soaking is measured and substituted into the formula to calculate the mass of liquid absorbed per unit mass of the material, expressed as a percentage.

[0058] Absorption uniformity: Take 50mL of deionized water, add 3 drops of food coloring, and stir evenly to obtain a test solution that is easy to observe. Use the finished pad prepared by the present invention as a sample, spread the sample flat on a flat laboratory table, use a dropper to draw 5mL of test solution and vertically add it to the center of the sample. After 5 minutes of addition, observe the diffusion of the test solution on the sample. The results are shown in the following table:

[0059]

[0060] Conclusion: The dosage of Examples 1 to 3 remains unchanged, and only some reaction parameters are modified. From the experimental data, it can be seen that there is no significant fluctuation in the performance of the samples.

[0061] Comparative Example 1: The propylene-modified chitosan antibacterial material was removed, and the rest was the same as Example 1. It can be seen from the experimental data that the antibacterial rate was 78.2% compared with Example 1. The reason for analysis is that the propylene-modified chitosan antibacterial material contains a variety of antibacterial substances such as Schiff base C=N structure and chitosan antibacterial material, so it can effectively improve the antibacterial properties of the sample. Therefore, after removing it, the antibacterial performance is reduced and the antibacterial rate decreases.

[0062] Comparative Example 2: The modified super-hydrophilic non-woven fabric was removed, and the rest was the same as Example 1. The experimental data showed that compared with Example 1, the absorption rate was 8 seconds, the water absorption rate was 740%, and the color distribution on the surface of the sheet sample was uneven, with local color concentration. The reason for this was analyzed as follows: the modified super-hydrophilic non-woven fabric, as the inner super-hydrophilic layer, has a strong hydrophilicity, which can absorb liquid transferred from the hydrophilic layer at a faster rate and promote the rapid diffusion of liquid to the surrounding area, allowing the absorbent material inside the sheet to be more fully utilized, avoiding local accumulation of liquid and increasing the overall absorption capacity. Therefore, after removing the modified super-hydrophilic non-woven fabric, the absorption rate slowed down, the water absorption rate decreased, and local accumulation occurred.

[0063] Comparative Example 3: The modified super-hydrophilic non-woven fabric and the hydrophilic non-woven fabric are replaced with ordinary non-woven fabric, and the rest are the same as Example 1. It can be seen from the experimental data that compared with Example 1, the absorption speed is 15s, the water absorption rate is 680%, the surface color of the pad sample is different in depth, and the color is concentrated in more areas. The reason is analyzed as follows: the present invention designs hydrophilic non-woven fabric as the surface layer and the modified super-hydrophilic non-woven fabric as the inner layer, which can allow the liquid to quickly pass through the hydrophilic layer into the super-hydrophilic layer and diffuse, avoiding local accumulation of liquid and increasing the overall absorption capacity. Therefore, after replacing the modified super-hydrophilic non-woven fabric and the hydrophilic non-woven fabric with ordinary non-woven fabric, the absorption speed slows down, the water absorption rate decreases, and there is a phenomenon of color concentration in more areas.

[0064] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "include," "comprise," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, article, or apparatus comprising a series of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus.

[0065] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art will be able to modify the technical solutions described in the aforementioned embodiments or substitute equivalents for some of the technical features. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A process for preparing a highly breathable and moisture-permeable medical sheet, characterized by: The following steps are involved: Step 1: adding tris(hydroxymethyl)aminomethane, 0.10-0.12 mol / L hydrochloric acid, and deionized water to obtain a buffer solution with a pH of 7.8-8.0; then adding tannic acid to the buffer solution to obtain a tannic acid solution; immersing the non-woven fabric in the tannic acid solution for 15-20 hours to obtain a hydrophilic non-woven fabric; Step 2: dissolving dopamine in deionized water, then adding tris(hydroxymethylaminomethane) and tris(hydroxymethylaminomethane) hydrochloride to obtain a dopamine buffer solution with a pH of 8.5-8.7; immersing the non-woven fabric in the dopamine buffer solution for 10-15 hours to obtain a super-hydrophilic non-woven fabric; then immersing the super-hydrophilic non-woven fabric in mercaptopropylmethyldimethoxysilane, reacting at 90-95° C. for 50-70 minutes to obtain a modified super-hydrophilic non-woven fabric; Step 3: acrylic acid and deionized water are mixed, and after thorough stirring, 48-50 wt% sodium hydroxide solution is added dropwise. After neutralization, trimethylolpropane triacrylate, propylene-modified chitosan antibacterial material, potassium persulfate, sodium bisulfite, and sodium lauryl sulfate are added. After stirring evenly, the temperature is raised to 50-60° C. and the reaction is carried out for 3-5 hours. After the reaction is completed, the colloid is crushed, dried, crushed, and sieved to obtain a super absorbent resin; the super absorbent resin is then laid out to form an absorption layer; Step 4: Cover the absorbent layer, modified super-hydrophilic non-woven fabric, and hydrophilic non-woven fabric on the anti-seepage layer in sequence, and bond them with hot melt adhesive by hot pressing to obtain a highly breathable and moisture permeable medical pad.

2. The process for preparing a highly breathable and moisture-permeable medical sheet according to claim 1, wherein: In step 1, in the tannic acid solution, the reaction mass ratio of tris(hydroxymethyl)aminomethane to tannic acid is 12:(5-6).

3. The process for preparing a highly breathable and moisture permeable medical sheet according to claim 1, wherein: In step 2, the mass volume ratio of dopamine and deionized water is (0.004-0.005):

2.

4. The process for preparing a highly breathable and moisture permeable medical sheet according to claim 1, wherein: In step three, the contents of each component of the super absorbent resin are as follows: by mass: 350-400 parts of acrylic acid, 470-500 parts of deionized water, 240-270 parts of sodium hydroxide solution, 3.5-4.0 parts of trimethylolpropane triacrylate, 3-5 parts of propylene-modified chitosan antibacterial material, 0.7-1.0 parts of potassium persulfate, 0.4-0.6 parts of sodium bisulfite, and 0.2-0.3 parts of sodium lauryl sulfate.

5. The process for preparing a highly breathable and moisture permeable medical sheet according to claim 4, wherein: The preparation process of the propenyl-modified chitosan antibacterial material is as follows: chitosan and 5-chlorosalicylaldehyde are dissolved in dimethyl sulfoxide, and then 4A molecular sieves are added, and the mixture is stirred and reacted at 60-65°C for 10-15 hours. After the reaction is completed, the mixture is separated by precipitation, washed, and freeze-dried to obtain Schiff-alkalized chitosan; then the Schiff-alkalized chitosan, inhibitor methylhydroquinone, triethylamine and tetrahydrofuran are mixed, stirred at 65-75°C until dissolved, and then a tetrahydrofuran solution of acryloyl chloride is added dropwise, and the stirring reaction is continued for 12-14 hours. After the reaction is completed, the mixture is separated, washed, filtered, rotary evaporated, and recrystallized to obtain the propenyl-modified chitosan antibacterial material.

6. The process for preparing a highly breathable and moisture permeable medical sheet according to claim 5, wherein: When preparing Schiff-alkalized chitosan, the reaction mass ratio of chitosan, 5-chlorosalicylaldehyde and 4A molecular sieve is 3:(1.7-2.0):0.

7.

7. The process for preparing a highly breathable and moisture permeable medical sheet according to claim 5, wherein: When preparing the propylene-modified chitosan antibacterial material, the reaction mass ratio of Schiff-alkalized chitosan and acryloyl chloride is 1:(1.0-1.2).

8. The process for preparing a highly breathable and moisture permeable medical sheet according to claim 1, wherein: In step three, the laying and forming process parameters are: temperature of 25-35°C, pressure of 0.3-0.5MPa, and speed of 5-7m / min.

9. The process for preparing a highly air- and moisture-permeable medical sheet according to claim 1, wherein: In step 4, the hot pressing pressure is 2-3kgf / m 2 The hot pressing temperature is divided into two stages: the first stage is heating at 60-70°C for 1-2 hours, and the second stage is heating at 100-150°C for 2-3 minutes; the anti-seepage layer is a breathable SMS non-woven fabric.

10. A highly breathable and moisture permeable medical pad, characterized in that: Prepared according to the preparation process according to any one of claims 1 to 9.

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