Hydrophilic antibacterial dressing and preparation method thereof

Abstract

The invention relates to the field of medical materials, in particular to a hydrophilic antibacterial dressing and a preparation method thereof. The hydrophilic antibacterial dressing is prepared by mixing and foaming an isocyanate-terminated antibacterial hydrophilic prepolymer and a functional foaming mixture according to the mass ratio of (1-2): (1-2), wherein the isocyanate-terminated antibacterial hydrophilic prepolymer is prepared from the following raw materials in parts by weight: 10 to 100 parts of polyol I, 1 to 20 parts of a cationic polymer, 10 to 40 parts of isocyanate, 0.1 to 5 parts of a chain extender and 0.3 to 7 parts of an antioxidant; the functional foaming mixture is prepared from the following raw materials in parts by weight: 1-50 parts of polyol II, 1-20 parts of a hydrophilic surfactant, 1-20 parts of a foam stabilizer and 1-100 parts of purified water. According to the hydrophilic antibacterial dressing, an antibacterial group of a cationic polymer is grafted on a polyurethane chain segment to prepare a polyurethane prepolymer, the finally prepared polyurethane foaming dressing has lasting antibacterial performance and high water absorption, and the wound healing speed can be remarkably increased.

Description

Technical Field

[0001] The invention relates to the field of medical materials, and in particular to a hydrophilic antibacterial dressing and a preparation method thereof. Background Art

[0002] The development of science and technology has led to higher and higher requirements for medical dressings. Traditional dressings such as gauze and cotton are prone to breed bacteria, and wound exudate is easy to form scabs together with dry dermal tissue, hindering epithelialization; at the same time, the wound is easy to adhere to the dressing, causing pain when changing the dressing and bringing secondary trauma.

[0003] Polyurethane foam dressing is a commonly used functional dressing used to treat and prevent various traumatic wounds. Made of polyurethane material, polyurethane foam dressing is soft, breathable and highly absorbent. It can effectively absorb wound exudate and keep the wound healing. At the same time, it can also form a protective layer to prevent external bacteria and pollutants from entering the wound, reducing the risk of infection.

[0004] However, ordinary polyurethane foam dressings have a simple structure and single function, and cannot meet the multifunctional requirements of wound dressings. Especially in terms of antibacterial properties and wound healing speed, the existing polyurethane foam dressings have poor antibacterial properties and poor wound adhesion, which greatly affects the user experience.

[0005] Therefore, there is an urgent need for a hydrophilic antibacterial dressing to solve the above technical problems. Summary of the invention

[0006] The main purpose of the present invention is to provide a hydrophilic antibacterial dressing, which has good environmental protection and safety, has long-lasting antibacterial properties and high water absorption, and can significantly improve the healing speed of wounds.

[0007] To achieve the above-mentioned purpose, the present invention provides a hydrophilic antibacterial dressing, which is prepared by mixing and foaming an isocyanate-terminated antibacterial hydrophilic prepolymer and a functional foaming mixture in a mass ratio of 1-2:1-2; wherein the isocyanate-terminated antibacterial hydrophilic prepolymer is made of the following raw materials in parts by weight: 10-100 parts of polyol I, 1-20 parts of cationic polymer, 10-40 parts of isocyanate, 0.1-5 parts of chain extender and 0.3-7 parts of antioxidant; the functional foaming mixture is made of the following raw materials in parts by weight: 1-50 parts of polyol II, 1-20 parts of hydrophilic surfactant, 1-20 parts of foam leveling agent and 1-100 parts of purified water.

[0008] The hydrophilic antibacterial dressing of the present invention is prepared by using components such as polyols, cationic polymers, isocyanates, chain extenders and antioxidants to prepare antibacterial polyurethane prepolymers, which have a synergistic effect. The hydrophilic antibacterial dressing finally prepared by combining with a functional foaming mixture has long-lasting antibacterial properties and high water absorption, good environmental protection and safety, and can significantly improve the wound healing speed.

[0009] Preferably, the isocyanate-terminated antibacterial hydrophilic prepolymer is prepared by the following method:

[0010] S1, heating and mixing polyol I and a cationic polymer, and cooling to obtain a first mixture;

[0011] S2, adding the first mixture to isocyanate and heating with stirring to obtain a second mixture;

[0012] S3, mixing the second mixture and a chain extender to obtain a third mixture;

[0013] S4, mixing the third mixture and an antioxidant to obtain the isocyanate-terminated antibacterial hydrophilic prepolymer.

[0014] The invention prepares an isocyanate-terminated antibacterial hydrophilic prepolymer by heating a polyol and a cationic polymer to form a mixture, and then reacting the mixture with isocyanate. The hydroxyl group (-OH) of the cationic polymer acts as a nucleophilic agent to chemically react with the carbon atom (NCO) of the isocyanate molecule to release carbon dioxide, and finally generates an antibacterial synthetic compound of a carbamate or carbamate urea derivative; then, the polyol reacts with the isocyanate to generate a carbamate group to form a hydrophilic polyurethane polymer; and the isocyanate-terminated antibacterial hydrophilic prepolymer is obtained through a chain extension reaction. The cationic polymer acts as an antibacterial agent to permanently graft the antibacterial group onto the polyurethane chain segment, and the polyol hydrophilic group is grafted onto the polyurethane chain segment at the same time. The antibacterial hydrophilic prepolymer is obtained through a chain extender reaction, and finally a hydrophilic antibacterial dressing is obtained. By regulating the reaction sequence of the raw material components, the antibacterial performance of the obtained hydrophilic antibacterial dressing is more durable, the effect is better, and the wound healing speed is accelerated.

[0015] Preferably, in the above step S1, the heating temperature is 100-120°C, the reaction time is 2-6h, and the temperature is cooled to 30-75°C.

[0016] Preferably, in the above step S2, the heating temperature is 40-80°C and the reaction time is 3-5h.

[0017] Preferably, in the above step S4, the NCO content of the prepared isocyanate-terminated antibacterial hydrophilic prepolymer is 9%.

[0018] Preferably, the isocyanate-terminated antimicrobial hydrophilic prepolymer is made from the following raw materials in parts by weight: 68-71 parts of polyol I, 3-5 parts of cationic polymer, 25-28 parts of isocyanate, 0.1-1.5 parts of chain extender and 0.3-1 part of antioxidant;

[0019] The functional foaming mixture is prepared from the following raw materials in parts by weight: 4-5 parts of polyol II, 3-3.5 parts of hydrophilic surfactant, 1-2 parts of foam leveling agent and 100 parts of purified water.

[0020] Preferably, the mass ratio of polyol I: cationic polymer: isocyanate in the raw materials for preparing the isocyanate-terminated antibacterial hydrophilic prepolymer is 14:1:5.

[0021] Preferably, the cationic polymer is one or more of sulfadiazine, polyhexamethyleneguanidine hydrochloride, polyhexamethylenebiguanide hydrochloride, isoquinolinium salt and peptoid hesitantium polymer.

[0022] Preferably, the polyol I is one or more of polyethylene glycol polyol and ethylene oxide-propylene oxide (EO-PO) copolymer polyol, wherein the average functionality of the polyol I is 2-3, the average molecular weight is 300-4000, and the molar percentage of EO block is not less than 50%. Preferably, the molar percentage of EO block in the polyol I is not less than 70%.

[0023] Preferably, the isocyanate is one or more of toluene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, dicyclohexylmethane diisocyanate and isophorone diisocyanate.

[0024] Preferably, the isocyanate is one or more of diphenylmethane diisocyanate, toluene diisocyanate and hexamethylene diisocyanate.

[0025] Preferably, the chain extender is one or more of propylene glycol, 1,4-butanediol, ethylene glycol, diethanolamine and triethanolamine trimethylolpropane. Preferably, the chain extender is 1,4-butanediol.

[0026] Preferably, the antioxidant is one or more of antioxidant 245, antioxidant 1790, antioxidant GA-80, aromatic amines, antioxidant V-900, IRGASTAB PUR 68, Irganox B215 and NIAX CS-15.

[0027] Preferably, the polyol II is one or more of polyethylene glycol polyol and ethylene oxide-propylene oxide (EO-PO) copolymer polyol, wherein the average functionality of the polyol II is 2 to 3, the average molecular weight is 1000 to 20000, and the molar percentage of EO block is not less than 80%.

[0028] Preferably, the hydrophilic surfactant is one or more of fatty alcohol polyoxyethylene ether, polyoxyethylene fatty acid ester, EO / PO block polyether, polyglycerol fatty acid ester, castor oil polyoxyethylene ether, linear octa-carbon isooctyl alcohol polyoxyethylene ether, polyoxyethylene alkyl ether and sorbitan fatty acid ester. Preferably, the hydrophilic surfactant is sorbitan fatty acid ester.

[0029] Preferably, the foam leveling agent is one or more of polysiloxane, organosiloxane, H-8800, F-5580, H-963 and H-962.

[0030] On the other hand, the present invention also provides a method for preparing the above hydrophilic antibacterial dressing, comprising the following steps:

[0031] 1) mixing polyol II, a hydrophilic surfactant, a foam leveler and purified water to obtain the functional foaming mixture;

[0032] 2) uniformly mixing the functional foaming mixture and the isocyanate-terminated antibacterial hydrophilic prepolymer at high speed, and preparing the hydrophilic antibacterial foam after foaming and aging;

[0033] 3) Compounding the hydrophilic antibacterial foam with a backing layer and a protective layer to obtain the hydrophilic antibacterial dressing.

[0034] The backing layer can be made of a known base material applicable to dressings, including but not limited to non-woven tape, adhesive PU film, etc.; the protective layer can be made of a known protective film material with a release function, including but not limited to release paper, etc. The backing layer is made of a known viscose material, including but not limited to silicone, hydrocolloid, hydrogel, acrylic acid, etc.

[0035] Preferably, in the above step 2), before mixing and foaming, the isocyanate-terminated antibacterial hydrophilic prepolymer is heated to 60°C, the aging temperature is 60-90°C, and the aging time is 1-5h; the speed of the high-speed mixing is 4000rpm, and the stirring time is 10-100s.

[0036] The hydrophilic antibacterial dressing prepared by the preparation method of the present invention is environmentally friendly and non-toxic, has no harm to the skin, has a long-lasting antibacterial effect, and can promote wound healing faster. DETAILED DESCRIPTION

[0037] The technical solutions in the embodiments of the present invention will be described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without creative work belong to the scope of protection of the present invention. It should be noted that the embodiments in this application and the features in the embodiments can be combined with each other without conflict. At the same time, the raw materials mentioned below that are not described in detail are not commercially available products; the process steps or preparation methods not mentioned in detail are all process steps or preparation methods known to those skilled in the art.

[0038] The invention discloses a hydrophilic antibacterial dressing, which is prepared by mixing and foaming an isocyanate-terminated antibacterial hydrophilic prepolymer and a functional foaming mixture at a mass ratio of 1-2:1-2; wherein the isocyanate-terminated antibacterial hydrophilic prepolymer is prepared from the following raw materials in parts by weight: 10-100 parts of polyol I, 1-20 parts of cationic polymer, 10-40 parts of isocyanate, 0.1-5 parts of chain extender and 0.3-7 parts of antioxidant; and the functional foaming mixture is prepared from the following raw materials in parts by weight: 1-50 parts of polyol II, 1-20 parts of hydrophilic surfactant, 1-20 parts of foam leveling agent and 1-100 parts of purified water.

[0039] Preferably, the isocyanate-terminated antibacterial hydrophilic prepolymer is made from the following raw materials in parts by weight: 68-71 parts of polyol I, 3-5 parts of cationic polymer, 25-28 parts of isocyanate, 0.1-1.5 parts of chain extender and 0.3-1 part of antioxidant; the functional foaming mixture is made from the following raw materials in parts by weight: 4-5 parts of polyol II, 3-3.5 parts of hydrophilic surfactant, 1-2 parts of foam leveling agent and 100 parts of purified water.

[0040] The preparation method of the hydrophilic antibacterial dressing comprises the following steps:

[0041] (I) Synthesis of isocyanate-terminated antibacterial hydrophilic prepolymer:

[0042] S1, vacuum drying the polyol I and the cationic polymer at 100-130° C. to remove water for 2-6 hours, and cooling to 30-75° C. to obtain a first mixture;

[0043] S2. Under nitrogen protection, adding the first mixture to isocyanate, reacting at 40-80° C. for 3-5 hours to obtain a second mixture;

[0044] S3, mixing and stirring the second mixture and the chain extender under nitrogen protection for 0.5 to 1.5 hours to obtain a third mixture;

[0045] S4, mixing the third mixture and the antioxidant under nitrogen protection for 1 to 3 hours until the NCO content reaches 9%, thereby obtaining an isocyanate-terminated antibacterial hydrophilic prepolymer;

[0046] (ii) Synthesizing a functional foaming mixture: mixing polyol II, a hydrophilic surfactant, a foam leveler and purified water uniformly to obtain a functional foaming mixture;

[0047] (3) heating the isocyanate-terminated antibacterial hydrophilic prepolymer to 60° C., stirring at 4000 rpm, adding the functional foaming mixture, continuing to stir and disperse for 10 to 100 seconds, and preparing the hydrophilic antibacterial foam through foaming and aging; wherein the mass ratio of the isocyanate-terminated antibacterial hydrophilic prepolymer to the functional foaming mixture is 1 to 2:1 to 2; the aging temperature is 60 to 90° C., and the aging time is 1 to 5 hours.

[0048] (iv) Compounding the hydrophilic antibacterial foam, the backing layer and the protective layer through an applicator, and punching, thereby obtaining a hydrophilic antibacterial dressing.

[0049] Those skilled in the art should know that the backing layer can be made of known base materials applicable to dressings, including but not limited to non-woven tape, adhesive PU film, etc.; the protective layer can be made of known protective film materials with release function, including but not limited to release paper, etc. The backing layer is made of known viscose materials, including but not limited to silicone, hydrocolloid, hydrogel, acrylic acid, etc.

[0050] In some specific embodiments, the mass ratio of polyol I: cationic polymer: isocyanate in the raw materials for preparing isocyanate-terminated antibacterial hydrophilic prepolymer is 14:1:5.

[0051] In the present invention, the cationic polymer is selected from one or more of sulfadiazine, polyhexamethylene guanidine hydrochloride, polyhexamethylene biguanide hydrochloride (PHMB), isoquinolinium salt and peptoid uranium polymer. Polyol I is selected from one or more of polyethylene glycol polyol and ethylene oxide-propylene oxide (EO-PO) copolymer polyol; wherein the average functionality of polyol I is 2-3, the average molecular weight is 300-4000, and the molar percentage of EO block is not less than 50%, preferably, not less than 70%. Isocyanate is selected from one or more of toluene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), hexamethylene diisocyanate (HDI), dicyclohexylmethane diisocyanate (HMDI) and isophorone diisocyanate (IPDI). Preferably, isocyanate is selected from one or more of diphenylmethane diisocyanate, toluene diisocyanate and hexamethylene diisocyanate. The chain extender is selected from one or more of propylene glycol, 1,4-butanediol, ethylene glycol, diethanolamine and triethanolamine trimethylolpropane. Preferably, the chain extender is 1,4-butanediol. The antioxidant is selected from one or more of antioxidant 245, antioxidant 1790, antioxidant GA-80, aromatic amines, antioxidant V-900, IRGASTAB PUR 68, Irganox B215 and NIAX CS-15. Polyol II is selected from one or more of polyethylene glycol polyols and ethylene oxide-propylene oxide (EO-PO) copolymer polyols, wherein the average functionality of the polyol II is 2 to 3, the average molecular weight is 1000 to 20000, and the molar percentage of the EO block is not less than 80%. The hydrophilic surfactant is selected from one or more of fatty alcohol polyoxyethylene ether, polyoxyethylene fatty acid ester, EO / PO block polyether, polyglycerol fatty acid ester, castor oil polyoxyethylene ether, linear octa-carbon isooctyl alcohol polyoxyethylene ether, polyoxyethylene alkyl ether and sorbitan fatty acid ester. Preferably, the hydrophilic surfactant is sorbitan fatty acid ester. The foam leveling agent is selected from one or more of polysiloxane, organosiloxane, H-8800, F-5580, H-963 and H-962.

[0052] In the prior art, the antibacterial properties of polyurethane foam dressings are usually achieved by spraying a layer of inorganic silver antibacterial agent on the surface of polyurethane foam dressings or directly adding a blended antibacterial agent. However, the antibacterial agent in the traditional method is prone to migration and degradation in the polyurethane material, resulting in a decrease in antibacterial properties and poor antibacterial durability. At the same time, as a wound dressing, polyurethane foam dressings are used in the special environment of the wound surface, and there are also high requirements for its water absorption and wettability. The hydrophilic antibacterial dressing of the present invention is prepared by reacting a cationic polymer with polyol I first and then adding the polymer to isocyanate to form a stable antibacterial polyurethane prepolymer. The polyurethane foam dressing obtained by foaming the prepolymer with a functional foaming mixture not only has a lasting antibacterial property, but also selects specific components such as polyol I, polyol II, isocyanate, and chain extender. Through the synergistic effect of the components, the polyurethane foam dressing has good hydrophilicity and moisture permeability, good liquid absorption and retention capacity, and is safe and non-toxic. When the hydrophilic antibacterial dressing is covered, the wound surface produces a slightly moist, slightly acidic and hypoxic environment, which can accelerate the autolytic debridement of necrotic tissue on the wound surface, promote tissue repair and re-epithelialization, avoid secondary infection of the wound by bacteria and microorganisms, and significantly improve the wound healing speed.

[0053] The following examples are further cited to illustrate the present invention in detail. The specific process parameters of the following examples are only examples within a suitable range, and those skilled in the art can make selections within a suitable range through the description herein, but are not limited to the specific values ​​of the examples below. If specific conditions are not specified in the examples, they are carried out according to conventional conditions or conditions recommended by the manufacturer. If the manufacturer is not specified for the reagents or instruments used, they are all conventional products that can be purchased commercially.

[0054] Example 1

[0055] A hydrophilic antibacterial dressing, the raw material components are shown in Table 1, and the preparation method thereof comprises the following steps:

[0056] (I) Synthesis of isocyanate-terminated antibacterial hydrophilic prepolymer:

[0057] S1, vacuum drying polyol I and cationic polymer at 100° C. to remove water for 6 h, cooling to 75° C. to obtain a first mixture;

[0058] S2. Under nitrogen protection, adding the first mixture to isocyanate, reacting at 50° C. for 5 h to obtain a second mixture;

[0059] S3, mixing and stirring the second mixture and the chain extender under nitrogen protection for 0.5 h to obtain a third mixture;

[0060] S4, mixing and stirring the third mixture and the antioxidant under nitrogen protection for 3 hours until the NCO content reaches 9%, thereby obtaining an isocyanate-terminated antibacterial hydrophilic prepolymer;

[0061] (ii) synthesizing a functional foaming mixture: mixing polyol II, a hydrophilic surfactant, a foam leveling agent and purified water uniformly to obtain a functional foaming mixture;

[0062] (III) Heat 130 g of isocyanate-terminated antibacterial hydrophilic prepolymer to 60° C., stir at 4000 rpm, add 70 g of functional foaming mixture, continue stirring and dispersing for 15 seconds, pour the dispersed mixture into a mold for foaming, and mature the foamed material at 60° C. for 5 hours to obtain a hydrophilic antibacterial foam.

[0063] (iv) Compounding the hydrophilic antibacterial foam, the adhesive PU film and the release paper through an applicator, and punching and cutting, thereby obtaining a hydrophilic antibacterial dressing.

[0064] Example 2

[0065] A hydrophilic antibacterial dressing, the raw material components are shown in Table 1, and the preparation method thereof comprises the following steps:

[0066] (I) Synthesis of isocyanate-terminated antibacterial hydrophilic prepolymer:

[0067] S1, vacuum drying polyol I and cationic polymer at 110° C. to remove water for 5 h, cooling to 70° C. to obtain a first mixture;

[0068] S2. Under nitrogen protection, adding the first mixture to isocyanate, reacting at 60° C. for 4 h to obtain a second mixture;

[0069] S3, mixing and stirring the second mixture and the chain extender under nitrogen protection for 1 hour to obtain a third mixture;

[0070] S4, mixing and stirring the third mixture and the antioxidant under nitrogen protection for 2 hours until the NCO content is 9%, thereby obtaining an isocyanate-terminated antibacterial hydrophilic prepolymer;

[0071] (ii) synthesizing a functional foaming mixture: mixing polyol II, a hydrophilic surfactant, a foam leveling agent and purified water uniformly to obtain a functional foaming mixture;

[0072] (III) Heat 115 g of isocyanate-terminated antibacterial hydrophilic prepolymer to 60° C., stir at 4000 rpm, add 85 g of functional foaming mixture, continue stirring and dispersing for 20 seconds, pour the dispersed mixture into a mold for foaming, and mature the foamed material at 70° C. for 4 hours to obtain a hydrophilic antibacterial foam.

[0073] (iv) Compounding the hydrophilic antibacterial foam, the adhesive PU film and the release paper through an applicator, and punching and cutting, thereby obtaining a hydrophilic antibacterial dressing.

[0074] Example 3

[0075] A hydrophilic antibacterial dressing, the raw material components are shown in Table 1, and the preparation method thereof comprises the following steps:

[0076] (I) Synthesis of isocyanate-terminated antibacterial hydrophilic prepolymer:

[0077] S1, vacuum drying polyol I and cationic polymer at 120° C. to remove water for 4 h, cooling to 75° C. to obtain a first mixture;

[0078] S2. Under nitrogen protection, adding the first mixture to isocyanate, reacting at 70° C. for 3 h to obtain a second mixture;

[0079] S3, mixing and stirring the second mixture and the chain extender under nitrogen protection for 1 hour to obtain a third mixture;

[0080] S4, mixing and stirring the third mixture and the antioxidant under nitrogen protection for 2 hours until the NCO content is 9%, thereby obtaining an isocyanate-terminated antibacterial hydrophilic prepolymer;

[0081] (ii) synthesizing a functional foaming mixture: mixing polyol II, a hydrophilic surfactant, a foam leveling agent and purified water uniformly to obtain a functional foaming mixture;

[0082] (III) Heat 100 g of isocyanate-terminated antibacterial hydrophilic prepolymer to 60° C., stir at 4000 rpm, add 100 g of functional foaming mixture, continue stirring and dispersing for 30 seconds, pour the dispersed mixture into a mold for foaming, and mature the foamed material at 80° C. for 3 hours to obtain a hydrophilic antibacterial foam.

[0083] (iv) Compounding the hydrophilic antibacterial foam, the adhesive PU film and the release paper through an applicator, and punching and cutting, thereby obtaining a hydrophilic antibacterial dressing.

[0084] Example 4

[0085] A hydrophilic antibacterial dressing, the raw material components are shown in Table 1, and the preparation method thereof comprises the following steps:

[0086] (I) Synthesis of isocyanate-terminated antibacterial hydrophilic prepolymer:

[0087] S1, vacuum drying polyol I and cationic polymer at 125° C. to remove water for 3 h, cooling to 75° C. to obtain a first mixture;

[0088] S2. Under nitrogen protection, adding the first mixture to isocyanate, reacting at 75° C. for 4 hours to obtain a second mixture;

[0089] S3, mixing and stirring the second mixture and the chain extender under nitrogen protection for 0.5 h to obtain a third mixture;

[0090] S4, mixing and stirring the third mixture and the antioxidant under nitrogen protection for 2 hours until the NCO content is 9%, thereby obtaining an isocyanate-terminated antibacterial hydrophilic prepolymer;

[0091] (ii) synthesizing a functional foaming mixture: mixing polyol II, a hydrophilic surfactant, a foam leveling agent and purified water uniformly to obtain a functional foaming mixture;

[0092] (III) Heat 90 g of isocyanate-terminated antibacterial hydrophilic prepolymer to 60° C., stir at 4000 rpm, add 110 g of functional foaming mixture, continue stirring and dispersing for 60 seconds, pour the dispersed mixture into a mold for foaming, and mature the foamed material at 85° C. for 2 hours to obtain a hydrophilic antibacterial foam.

[0093] (iv) Compounding the hydrophilic antibacterial foam, the adhesive PU film and the release paper through an applicator, and punching and cutting, thereby obtaining a hydrophilic antibacterial dressing.

[0094] Example 5

[0095] A hydrophilic antibacterial dressing, the raw material components are shown in Table 1, and the preparation method thereof comprises the following steps:

[0096] (I) Synthesis of isocyanate-terminated antibacterial hydrophilic prepolymer:

[0097] S1, vacuum drying the polyol I and the cationic polymer at 130° C. to remove water for 2 h, and cooling to 75° C. to obtain a first mixture;

[0098] S2. Under nitrogen protection, adding the first mixture to isocyanate, reacting at 80° C. for 3 h to obtain a second mixture;

[0099] S3, mixing and stirring the second mixture and the chain extender under nitrogen protection for 1.5 hours to obtain a third mixture;

[0100] S4, mixing and stirring the third mixture and the antioxidant under nitrogen protection for 3 hours until the NCO content reaches 9%, thereby obtaining an isocyanate-terminated antibacterial hydrophilic prepolymer;

[0101] (ii) synthesizing a functional foaming mixture: mixing polyol II, a hydrophilic surfactant, a foam leveling agent and purified water uniformly to obtain a functional foaming mixture;

[0102] (III) Heat 70 g of isocyanate-terminated antibacterial hydrophilic prepolymer to 60° C., stir at 4000 rpm, add 130 g of functional foaming mixture, continue stirring and dispersing for 80 seconds, pour the dispersed mixture into a mold for foaming, and mature the foamed material at 90° C. for 1 hour to obtain a hydrophilic antibacterial foam.

[0103] (iv) Compounding the hydrophilic antibacterial foam, the adhesive PU film and the release paper through an applicator, and punching and cutting, thereby obtaining a hydrophilic antibacterial dressing.

[0104] Example 6

[0105] A hydrophilic antibacterial dressing, the raw material components are shown in Table 1, and the preparation method thereof comprises the following steps:

[0106] (I) Synthesis of isocyanate-terminated antibacterial hydrophilic prepolymer:

[0107] S1, vacuum drying polyol I and cationic polymer at 120° C. to remove water for 4 h, cooling to 75° C. to obtain a first mixture;

[0108] S2. Under nitrogen protection, adding the first mixture to isocyanate, reacting at 70° C. for 3 h to obtain a second mixture;

[0109] S3, mixing and stirring the second mixture and the chain extender under nitrogen protection for 1 hour to obtain a third mixture;

[0110] S4, mixing and stirring the third mixture and the antioxidant under nitrogen protection for 2 hours until the NCO content is 9%, thereby obtaining an isocyanate-terminated antibacterial hydrophilic prepolymer;

[0111] (ii) synthesizing a functional foaming mixture: mixing polyol II, a hydrophilic surfactant, a foam leveling agent and purified water uniformly to obtain a functional foaming mixture;

[0112] (III) Heat 100 g of isocyanate-terminated antibacterial hydrophilic prepolymer to 60° C., stir at 4000 rpm, add 100 g of functional foaming mixture, continue stirring and dispersing for 30 seconds, pour the dispersed mixture into a mold for foaming, and mature the foamed material at 80° C. for 3 hours to obtain a hydrophilic antibacterial foam.

[0113] (iv) Compounding the hydrophilic antibacterial foam, the adhesive PU film and the release paper through an applicator, and punching and cutting, thereby obtaining a hydrophilic antibacterial dressing.

[0114] Example 7

[0115] A hydrophilic antibacterial dressing, the raw material components are shown in Table 1, and the preparation method thereof comprises the following steps:

[0116] (I) Synthesis of isocyanate-terminated antibacterial hydrophilic prepolymer:

[0117] S1, vacuum drying the polyol I and the cationic polymer at 130° C. to remove water for 2 h, and cooling to 75° C. to obtain a first mixture;

[0118] S2. Under nitrogen protection, adding the first mixture to isocyanate, reacting at 80° C. for 3 h to obtain a second mixture;

[0119] S3, mixing and stirring the second mixture and the chain extender under nitrogen protection for 1.5 hours to obtain a third mixture;

[0120] S4, mixing and stirring the third mixture and the antioxidant under nitrogen protection for 3 hours until the NCO content reaches 9%, thereby obtaining an isocyanate-terminated antibacterial hydrophilic prepolymer;

[0121] (ii) synthesizing a functional foaming mixture: mixing polyol II, a hydrophilic surfactant, a foam leveling agent and purified water uniformly to obtain a functional foaming mixture;

[0122] (III) Heat 70 g of isocyanate-terminated antibacterial hydrophilic prepolymer to 60° C., stir at 4000 rpm, add 130 g of functional foaming mixture, continue stirring and dispersing for 80 seconds, pour the dispersed mixture into a mold for foaming, and mature the foamed material at 90° C. for 1 hour to obtain a hydrophilic antibacterial foam.

[0123] (iv) Compounding the hydrophilic antibacterial foam, the adhesive PU film and the release paper through an applicator, and punching and cutting, thereby obtaining a hydrophilic antibacterial dressing.

[0124] Comparative Example 1

[0125] A hydrophilic antibacterial dressing, the raw material components are the same as those in Example 3, except that the preparation method thereof comprises the following steps:

[0126] (a) Synthetic prepolymer:

[0127] S1. Dry polyol I under vacuum at 120° C. to remove water for 4 h, cool to 75° C., add isocyanate under nitrogen protection, and react at 70° C. for 3 h to obtain a first mixture;

[0128] S2, mixing and stirring the first mixture and the chain extender under nitrogen protection for 1 hour to obtain a second mixture;

[0129] S3, mixing and stirring the second mixture and the antioxidant under nitrogen protection for 2 hours until the NCO content reaches 9%, thereby obtaining a prepolymer;

[0130] (ii) synthesizing a functional foaming mixture: mixing polyol II, a hydrophilic surfactant, a cationic polymer, a foam leveling agent and purified water to obtain a functional foaming mixture;

[0131] (iii) heating 100 g of the prepolymer to 60° C., stirring at 4000 rpm, adding 100 g of the functional foaming mixture, continuing to stir and disperse for 30 seconds, pouring the dispersed mixture into a mold for foaming, and aging the foamed material at 80° C. for 3 hours to obtain a hydrophilic antibacterial foam.

[0132] (iv) Compounding the hydrophilic antibacterial foam, the adhesive PU film and the release paper through an applicator, and punching and cutting, thereby obtaining a hydrophilic antibacterial dressing.

[0133] Comparative Example 2

[0134] (I) Synthesis of isocyanate-terminated antibacterial hydrophilic prepolymer:

[0135] S1, vacuum drying the vegetable oil polyol and the cationic polymer at 120° C. to remove water for 4 hours, and cooling to 75° C. to obtain a first mixture;

[0136] S2. Under nitrogen protection, adding the first mixture to isocyanate, reacting at 70° C. for 3 h to obtain a second mixture;

[0137] S3, mixing and stirring the second mixture and the chain extender under nitrogen protection for 1 hour to obtain a third mixture;

[0138] S4, mixing and stirring the third mixture and the antioxidant under nitrogen protection for 2 hours until the NCO content is 9%, thereby obtaining an isocyanate-terminated antibacterial hydrophilic prepolymer;

[0139] (ii) synthesizing a functional foaming mixture: mixing polyol II, a hydrophilic surfactant, a foam leveling agent and purified water uniformly to obtain a functional foaming mixture;

[0140] (III) Heat 100 g of isocyanate-terminated antibacterial hydrophilic prepolymer to 60° C., stir at 4000 rpm, add 100 g of functional foaming mixture, continue stirring and dispersing for 30 seconds, pour the dispersed mixture into a mold for foaming, and mature the foamed material at 80° C. for 3 hours to obtain a hydrophilic antibacterial foam.

[0141] (iv) Compounding the hydrophilic antibacterial foam, the adhesive PU film and the release paper through an applicator, and punching and cutting, thereby obtaining a hydrophilic antibacterial dressing.

[0142] Comparative Example 3

[0143] (I) Synthesis of isocyanate-terminated antibacterial hydrophilic prepolymer:

[0144] S1, vacuum drying polyol I and cationic polymer at 120° C. to remove water for 4 h, cooling to 75° C. to obtain a first mixture;

[0145] S2. Under nitrogen protection, adding the first mixture to isocyanate, reacting at 70° C. for 3 h to obtain a second mixture;

[0146] S3, mixing and stirring the second mixture and the chain extender under nitrogen protection for 1 hour to obtain a third mixture;

[0147] S4, mixing and stirring the third mixture and the antioxidant under nitrogen protection for 2 hours until the NCO content is 9%, thereby obtaining an isocyanate-terminated antibacterial hydrophilic prepolymer;

[0148] (ii) synthesizing a functional foaming mixture: mixing the polyester polyol, the hydrophilic surfactant, the foam leveling agent and purified water to obtain a functional foaming mixture;

[0149] (III) Heat 100 g of isocyanate-terminated antibacterial hydrophilic prepolymer to 60° C., stir at 4000 rpm, add 100 g of functional foaming mixture, continue stirring and dispersing for 30 seconds, pour the dispersed mixture into a mold for foaming, and mature the foamed material at 80° C. for 3 hours to obtain a hydrophilic antibacterial foam.

[0150] (iv) Compounding the hydrophilic antibacterial foam, the adhesive PU film and the release paper through an applicator, and punching and cutting, thereby obtaining a hydrophilic antibacterial dressing.

[0151] Comparative Example 4

[0152] (I) Synthesis of isocyanate-terminated antibacterial hydrophilic prepolymer:

[0153] S1, vacuum drying polyol I and cationic polymer at 120° C. to remove water for 4 h, cooling to 75° C. to obtain a first mixture;

[0154] S2. Under nitrogen protection, adding the first mixture to isocyanate, reacting at 70° C. for 3 h to obtain a second mixture;

[0155] S3, mixing and stirring the second mixture and diethyltoluenediamine under nitrogen protection for 1 h to obtain a third mixture;

[0156] S4, mixing and stirring the third mixture and the antioxidant under nitrogen protection for 2 hours until the NCO content is 9%, thereby obtaining an isocyanate-terminated antibacterial hydrophilic prepolymer;

[0157] (ii) synthesizing a functional foaming mixture: mixing polyol II, a hydrophilic surfactant, a foam leveling agent and purified water uniformly to obtain a functional foaming mixture;

[0158] (III) Heat 100 g of isocyanate-terminated antibacterial hydrophilic prepolymer to 60° C., stir at 4000 rpm, add 100 g of functional foaming mixture, continue stirring and dispersing for 30 seconds, pour the dispersed mixture into a mold for foaming, and mature the foamed material at 80° C. for 3 hours to obtain a hydrophilic antibacterial foam.

[0159] (iv) Compounding the hydrophilic antibacterial foam, the adhesive PU film and the release paper through an applicator, and punching and cutting, thereby obtaining a hydrophilic antibacterial dressing.

[0160] Table 1

[0161]

[0162]

[0163] The performance test standards and methods of the hydrophilic antibacterial dressing prepared by the present invention are as follows:

[0164] 1. Antibacterial performance (%): The method and standard of antibacterial performance test refer to the content of GB / T20944.2-2007, and make appropriate modifications and adjustments. The test sample and the control sample are inoculated with the test bacterial solution. Immediate elution and elution after culture are performed respectively. The number of bacteria in the elution solution is determined by a spectrophotometer and the antibacterial value or antibacterial rate is calculated to evaluate the antibacterial effect of the sample.

[0165] 2. Liquid absorption (g / g): The method and standard for testing liquid absorption performance refer to YY / T0471.1-2004. Accurately weigh the sample mass (W1) and place it in a culture dish. Add the test liquid preheated to (37±1)℃, the mass of which is 40 times that of the test material, ±0.5g. Move it into a drying oven and keep it at (37±1)℃ for 30 minutes. Clamp one corner or one end of the sample with tweezers, suspend it for 30 seconds, and weigh it (W2).

[0166] Liquid absorption (g / g) = (W2-W1) / W1

[0167] 3. Water vapor transmission rate (g·(m·24h) -1 ): The method and standard of water vapor transmission rate refer to YY / T0471.2-2004. Weigh and record the mass (W) of the container, sample and liquid to an accuracy of 0.0001g. Place the container in a drying oven or incubator with the sample facing upward and the temperature maintained at (37±1)℃. After 18h to 24h, take out each container from the drying oven or incubator and record the test time (T) to an accuracy of 5min. Immediately re-weigh the container, sample and liquid and record the mass (W2) to an accuracy of 0.000lg.

[0168] Calculate the water vapor transmission rate MVTR = (W-W2)*1000*24 / T

[0169] 4. Wound healing days (days): The methods and standards for wound healing effects refer to YY / T1477.2-2016. This standard establishes an experimental scald animal model with different degrees of scald on the back of rats according to the prescribed procedures. Multiple scald animal models can be prepared within a certain period of time to evaluate the wound healing performance of contact wound dressings after covering the scald wound.

[0170] 5. Foam pore size (μm): Take a complete hole in the foam sample under a microscope to measure the transverse pore diameter and the longitudinal pore diameter data, and record them. Add the measured transverse pore diameter and longitudinal pore diameter data to get the average value as the single pore diameter data. Take the average value of all single pore diameters as the foam pore size number of this batch of foam. It is generally believed that when the foam pore size is ≤300μm, the softness and comfort are good; 300μm<foam pore size≤800μm, the softness and comfort are qualified; when the foam pore size is>800μm, the softness and comfort are poor.

[0171] The various properties of Examples 1 to 7 and Comparative Examples 1 to 4 were tested. The antibacterial properties are shown in Table 2, and the liquid absorption performance, water vapor permeability of the breathable film dressing, foam pore size and wound healing effect are shown in Table 3.

[0172] Table 2

[0173]

[0174] Table 3

[0175]

[0176]

[0177] It can be seen from Table 2 and Table 3 that, compared with Comparative Examples 1 to 4, the hydrophilic antibacterial dressings prepared in Examples 1 to 7 have better antibacterial properties, better hygroscopicity, better air permeability, and better softness and comfort. The hydrophilic antibacterial dressing prepared by this solution can obviously obtain more lasting antibacterial properties and faster wound healing speed. Preferably, by weight, when polyol I is 68-71 parts, cationic polymer is 3-5 parts, isocyanate is 25-28 parts, chain extender is 0.1-1.5 parts and antioxidant is 0.3-1 parts; polyol II is 4-5 parts, hydrophilic surfactant is 3-3.5 parts, foam leveling agent is 1-2 parts and purified water is 100 parts, the antibacterial rate of Gram-negative bacteria Escherichia coli and the antibacterial rate of Gram-positive bacteria Staphylococcus aureus can reach more than 99%, and the antibacterial persistence is strong, and the antibacterial period can reach 5-7 days; the hydrophilicity is good, and the liquid absorption performance, water vapor permeability and softness are all good. The above formula ratio can better balance the antibacterial performance and the moisture absorption and breathability of the dressing, and the comprehensive performance is excellent. While having excellent antibacterial performance, the user experience is improved, and the wound healing time can be significantly improved. After testing, the wound healing days can be reduced to 10-12 days. In particular, when polyethylene glycol 600 is selected as polyol I, PHMB is selected as cationic polymer, and TDI is selected as isocyanate, and when the mass ratio of polyol I: cationic polymer: isocyanate is 14:1:5, that is, the technical solution of Example 3, the comprehensive performance of the obtained hydrophilic antibacterial dressing is the best. Although the same PHMB cationic polymer is also used in Comparative Example 1, due to different preparation processes, the addition order of PHMB is different, and it is only added to the functional foaming mixture by physical mixing. Therefore, the antibacterial performance and antibacterial persistence are significantly reduced, and the cationic polymer is placed in the functional foaming mixture, which will also directly affect the liquid absorption, water vapor permeability and foam pore size, and cannot obtain good moisture absorption and breathability. In Comparative Example 2, polyol I is replaced with vegetable oil polyol, in Comparative Example 3, polyol II is replaced with polyester polyol, and in Comparative Example 4, the chain extender used in this scheme is replaced with diethyltoluenediamine, which affects the molecular weight of the prepolymer, and none of them can obtain the antibacterial effect, hydrophilicity, moisture absorption and air permeability, and foam pore size described in this scheme, and the wound healing speed is significantly reduced. It should be noted that Examples 1 to 7 only exemplarily show the preferred components of each raw material, and when the remaining components in the raw material range of the present invention are used, the same technical effect is achieved.

[0178] In summary, the hydrophilic antibacterial dressing prepared by the present invention has good liquid absorption, liquid retention and moisture permeability, antibacterial function and softness, which can not only avoid fluid accumulation, but also maintain an appropriate wound microclimate on the wound surface, prevent scab formation, and facilitate wound healing. At the same time, it has a long-lasting antibacterial effect to prevent wound infection and significantly improve the healing speed of the wound.

[0179] The above description is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent structural changes made by using the contents of the present invention specification under the inventive concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A hydrophilic antibacterial dressing, characterized in that: The method is prepared by mixing and foaming an isocyanate-terminated antibacterial hydrophilic prepolymer and a functional foaming mixture in a mass ratio of 1-2:1-2. The isocyanate-terminated antibacterial hydrophilic prepolymer is made of the following raw materials in parts by weight: 10 to 100 parts of polyol I, 1 to 20 parts of cationic polymer, 10 to 40 parts of isocyanate, 0.1 to 5 parts of chain extender and 0.3 to 7 parts of antioxidant; The functional foaming mixture is prepared from the following raw materials in parts by weight: 1-50 parts of polyol II, 1-20 parts of hydrophilic surfactant, 1-20 parts of foam leveling agent and 1-100 parts of purified water.

2. The hydrophilic antibacterial dressing according to claim 1, characterized in that: The isocyanate-terminated antibacterial hydrophilic prepolymer is prepared by the following method: S1, heating and mixing polyol I and a cationic polymer, and cooling to obtain a first mixture; S2, adding the first mixture to isocyanate and heating with stirring to obtain a second mixture; S3, mixing the second mixture and a chain extender to obtain a third mixture; S4, mixing the third mixture and an antioxidant to obtain the isocyanate-terminated antibacterial hydrophilic prepolymer.

3. The hydrophilic antibacterial dressing according to claim 2, characterized in that: In step S1, the heating temperature is 100-120°C, the reaction time is 2-6 hours, and the temperature is cooled to 30-75°C.

4. The hydrophilic antibacterial dressing according to claim 2, characterized in that: In step S2, the heating temperature is 40-80°C and the reaction time is 3-5h.

5. The hydrophilic antibacterial dressing according to claim 2, characterized in that: In step S4, the NCO content of the prepared isocyanate-terminated antibacterial hydrophilic prepolymer is 9%.

6. The hydrophilic antibacterial dressing according to claim 1, characterized in that: The isocyanate-terminated antibacterial hydrophilic prepolymer is prepared from the following raw materials in parts by weight: 68-71 parts of polyol I, 3-5 parts of cationic polymer, 25-28 parts of isocyanate, 0.1-1.5 parts of chain extender and 0.3-1 part of antioxidant; The functional foaming mixture is prepared from the following raw materials in parts by weight: 4-5 parts of polyol II, 3-3.5 parts of hydrophilic surfactant, 1-2 parts of foam leveling agent and 100 parts of purified water.

7. The hydrophilic antibacterial dressing according to claim 1, characterized in that: The mass ratio of polyol I: cationic polymer: isocyanate in the raw materials for preparing the isocyanate-terminated antibacterial hydrophilic prepolymer is 14:1:

5.

8. The hydrophilic antibacterial dressing according to claim 1, characterized in that: The cationic polymer is one or more of sulfadiazine, polyhexamethyleneguanidine hydrochloride, polyhexamethylenebiguanidine hydrochloride, isoquinolinium salt and peptidyl stearylium polymer.

9. The hydrophilic antibacterial dressing according to claim 1, characterized in that: The polyol I is one or more of polyethylene glycol polyol and ethylene oxide-propylene oxide (EO-PO) copolymer polyol, wherein the average functionality of the polyol I is 2-3, the average molecular weight is 300-4000, and the molar percentage of EO block is not less than 50%.

10. The hydrophilic antibacterial dressing according to claim 1, characterized in that: The isocyanate is one or more of toluene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, dicyclohexylmethane diisocyanate and isophorone diisocyanate.

11. The hydrophilic antibacterial dressing according to claim 1, characterized in that: The chain extender is one or more of propylene glycol, 1,4-butanediol, ethylene glycol, diethanolamine and triethanolamine trimethylolpropane.

12. The hydrophilic antibacterial dressing according to claim 1, characterized in that: The antioxidant is one or more of antioxidant 245, antioxidant 1790, antioxidant GA-80, aromatic amines, antioxidant V-900, IRGASTAB PUR 68, Irganox B215 and NIAXCS-15.

13. The hydrophilic antibacterial dressing according to claim 1, characterized in that: The polyol II is one or more of polyethylene glycol polyol and ethylene oxide-propylene oxide (EO-PO) copolymer polyol, wherein the average functionality of the polyol II is 2-3, the average molecular weight is 1000-20000, and the molar percentage of EO block is not less than 70%.

14. The hydrophilic antibacterial dressing according to claim 1, characterized in that: The hydrophilic surfactant is one or more of fatty alcohol polyoxyethylene ether, polyoxyethylene fatty acid ester, EO / PO block polyether, polyglycerol fatty acid ester, castor oil polyoxyethylene ether, linear octacarbon isooctyl alcohol polyoxyethylene ether, polyoxyethylene alkyl ether and sorbitan fatty acid ester.

15. The hydrophilic antibacterial dressing according to claim 1, characterized in that: The foam leveling agent is one or more of polysiloxane, organosiloxane, H-8800, F-5580, H-963 and H-962.

16. A method for preparing a hydrophilic antibacterial dressing as claimed in any one of claims 1 to 15, characterized in that: The steps include: 1) mixing polyol II, a hydrophilic surfactant, a foam leveler and purified water to obtain the functional foaming mixture; 2) uniformly mixing the functional foaming mixture and the isocyanate-terminated antibacterial hydrophilic prepolymer at high speed, and preparing the hydrophilic antibacterial foam after foaming and aging; 3) Compounding the hydrophilic antibacterial foam with a backing layer and a protective layer to obtain the hydrophilic antibacterial dressing.

17. The preparation method according to claim 16, characterized in that: In step 2), before mixing and foaming, the isocyanate-terminated antibacterial hydrophilic prepolymer is heated to 60° C., the aging temperature is 60-90° C., and the aging time is 1-5 hours; the speed of the high-speed mixing is 4000 rpm, and the stirring time is 10-100 seconds.

18. The preparation method according to claim 16, characterized in that: The backing layer is any one of a non-woven tape and an adhesive PU film; the protective layer is release paper.

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