Foam stock solution for absorbing thick seepage, finger-shaped channel polyurethane foam as well as preparation method and application of foam stock solution and finger-shaped channel polyurethane foam

Abstract

The invention provides a foam stock solution for absorbing thick seepage, finger-shaped channel polyurethane foam as well as a preparation method and application of the finger-shaped channel polyurethane foam, and relates to the technical field of medical polyurethane dressings. The stock solution for absorbing the thick seepage foam comprises a stock solution A and a stock solution B in parts by weight, wherein the stock solution A comprises the following components in parts by weight: 1-20 parts of a hydrophilic chain extender, 1-10 parts of a surfactant, 1-10 parts of a lubricant, 0.1-2 parts of a catalyst and 50-99 parts of water; wherein the stock solution B is prepared from the following components in parts by weight: 50 to 200 parts of isocyanate prepolymer. The formula of the foam stock solution for absorbing the thick seepage comprises the stock solution A and the stock solution B, the stock solution A and the stock solution B are mixed and stirred and then coated and foamed to form polyurethane foam, and the polyurethane foam is special foam of a finger-shaped pore structure and has rich pore channels, so that the mass transfer performance of the polyurethane foam is improved, and the seepage absorption capacity of a foam dressing is improved.

Description

Technical Field

[0001] The invention relates to the technical field of medical wound dressings, in particular to a finger-shaped channel polyurethane foam for absorbing thick exudate foam stock solution and a preparation method and application thereof. Background Art

[0002] Wound dressings are often used to heal and protect wounds, and the ability of wound dressings to absorb and retain exudate from wounds is most important for the healing process. The liquid handling capacity of the dressing affects the frequency of dressing changes, which should be minimized to promote wound healing. In various applications, hydrophilic materials are used in wound dressings to absorb and retain wound fluids, and further in particular hydrophilic foams, such as hydrophilic open-cell polyurethane foams. Polyurethane foam is a porous polymer material that performs well in the application of medical wound dressings due to its unique softness, liquid absorption and biocompatibility.

[0003] Conventional polyurethane foam is generally formed by mixing polyols and isocyanates through coating and foaming. The pores in the foam are honeycomb-shaped, and its surface has hydrophilic groups that can attract water molecules and have good liquid absorption capacity. However, with the aging of the population and the increase in chronic diseases such as diabetes, the incidence of chronic wounds is also continuing to rise. Since chronic wounds often contain more proteins, cell fragments and necrotic tissue, this will directly lead to an increase in the viscosity of wound exudate, and greatly affect the efficiency of foam dressings in wound exudate management and the creation of a moist healing environment.

[0004] CN107185030A discloses a highly absorbent foam dressing and a preparation method thereof, wherein the composition of the highly absorbent foam dressing is: 10-40% starch, 26-40% polyurethane prepolymer, 0.6-1% crosslinking agent, 0.6-20% chain extender, 1.4-2% surfactant, 14-20% wetting agent, and 18-27% foaming agent. The invention adopts starch as a filler, so that the dressing not only has a higher and faster water absorption capacity. However, the foaming agent of the invention includes organic substances such as dichloromethane, n-hexane, n-pentane, and trichlorofluoromethane, which are less harmful to the human body, and the foam formed under the formula has honeycomb-shaped holes, and the connectivity between the holes is poor, which is not conducive to the rapid passage of substances, and the mass transfer performance of the polyurethane foam is poor.

[0005] CN118420858A discloses a high-absorption, high-bulge, high-liquid-locking polyurethane foam and its preparation, characterization and application, the preparation method comprising: S1, reacting 10 to 50 parts of isocyanate, 100 parts of polyol and 0 to 10 parts of cross-linking agent to obtain a hydrophilic polyurethane prepolymer; S2, first weighing 0.01 to 20 parts of surfactant and 0 to 10 parts of chain extender, mixing and stirring, then slowly adding 100 parts of water, stirring while adding water, until it is completely miscible with water to form a homogeneous solution, and then using it after the foam completely disappears; S3, mixing and stirring the hydrophilic polyurethane prepolymer prepared by S1 with the aqueous phase prepared by S2 to obtain a foaming liquid. The invention provides a polyurethane foam dressing with a certain ability to repair wounds and absorb exudate, but as can be clearly seen in the accompanying drawings provided in the specification, the polyurethane foam also presents a honeycomb hole structure, and there is also a problem of poor connectivity between holes, which is not conducive to the rapid passage of substances, and the mass transfer performance of the polyurethane foam is poor.

[0006] In view of this, the present invention is proposed. Summary of the invention

[0007] One of the purposes of the present invention is to provide a foam stock solution for absorbing thick exudate. The formula of the foam stock solution for absorbing thick exudate includes a stock solution A formed by a hydrophilic chain extender, a surfactant, water, a lubricant and a catalyst in a specific ratio and composition, and a stock solution B made of an isocyanate prepolymer. After the two are mixed and stirred in a certain proportion, they are coated and foamed to finally form the required polyurethane foam, which has a good liquid absorption effect.

[0008] The second object of the present invention is to provide a method for preparing the foam stock solution for absorbing thick exudate, the preparation method comprising the following steps: weighing a hydrophilic chain extender, a surfactant, a lubricant, a catalyst and water according to the formula amount, mixing and stirring to obtain a stock solution A; weighing an isocyanate prepolymer according to the formula amount, mixing and stirring to obtain a stock solution B.

[0009] The third object of the present invention is to provide a finger-shaped channel polyurethane foam, which is formed by mixing the stock solution A and the stock solution B in the above-mentioned foam stock solution for absorbing thick exudate, and then applying and foaming. The polyurethane foam is a special foam with a finger-shaped pore structure, which has abundant pores and can provide a fast mass transfer channel for medium migration. This structure is conducive to the rapid passage of substances, thereby improving the mass transfer performance of the polyurethane foam, and then improving the exudate absorption capacity of the foam dressing; and the pore size distribution is relatively wide, which can meet the mass transfer requirements of particles of different sizes.

[0010] The fourth object of the present invention is to provide a method for preparing the finger-shaped channel polyurethane foam, which comprises the following steps: mixing and stirring the stock solution A and the stock solution B, and then extruding at a constant flow rate to obtain an extruded liquid; coating the extruded liquid to form a flat foaming liquid, and drying to obtain the finger-shaped channel polyurethane foam.

[0011] A fifth object of the present invention is to provide a foam stock solution for absorbing thick exudate as described above, or use of the finger-shaped channel polyurethane foam as described above in preparing medical wound dressings or in preparing a core layer of a sanitary napkin.

[0012] In order to solve the above technical problems, the present invention particularly adopts the following technical solutions:

[0013] In a first aspect, the present invention provides a foam stock solution for absorbing thick exudate, wherein the foam stock solution for absorbing thick exudate comprises stock solution A and stock solution B in parts by weight; wherein the stock solution A comprises, in parts by weight: 1 to 20 parts of a hydrophilic chain extender, 1 to 10 parts of a surfactant, 1 to 10 parts of a lubricant, 0.1 to 2 parts of a catalyst and 50 to 99 parts of water; wherein the stock solution B comprises, in parts by weight: 50 to 200 parts of an isocyanate prepolymer.

[0014] Preferably, the foam stock solution for absorbing thick exudate includes stock solution A and stock solution B in parts by weight; wherein, the stock solution A includes, in parts by weight: 5 to 15 parts of hydrophilic chain extender, 3 to 8 parts of surfactant, 2 to 6 parts of lubricant, 0.1 to 2 parts of catalyst and 60 to 90 parts of water; wherein, the stock solution B includes, in parts by weight: 100 to 150 parts of isocyanate prepolymer.

[0015] Preferably, the foam stock solution for absorbing thick exudate includes stock solution A and stock solution B in parts by weight; wherein, the stock solution A includes, in parts by weight: 10 to 12 parts of hydrophilic chain extender, 4 to 6 parts of surfactant, 3 to 5 parts of lubricant, 0.5 to 1.5 parts of catalyst and 70 to 80 parts of water; wherein, the stock solution B includes, in parts by weight: 110 to 130 parts of isocyanate prepolymer.

[0016] Preferably, the hydrophilic chain extender includes polyoxypropylene triol, oxypropylene-oxyethylene copolyether triol, polycaprolactone, fructose, lactose, maltose, maltitol, trehalose, sucrose, tetrahydroxy polyether polyol, pentaerythritol polyether polyol, diamino polyether tetraol, polyether pentaol, polyether hexaol, polystyrene polyol, castor oil and castor oil derivative polyol, soybean oil polyol, palm oil polyol, rosin ester polyol, 4,4'-methylenebis(3-chloro-2,6-diethylaniline), 4,4'-methylenebis(2,6-diethyl)aniline, 4,4'-methylenebis(2-methyl-6-diethylaniline), 4,4'-methylenebis(2-diethylaniline), 4,4'-methylenebis(2,6-diisopropyl)aniline, 4,4'-methylenebis(2-methyl-6-diethylaniline). Methylbis(2-isopropyl-6-methyl)aniline, 2,4-diamino-3,5-dimethylthiochlorobenzene, propylene glycol bis(4-benzoate), 3,5-diamino-4-chlorobenzoic acid isobutyl ester, coconut diethanolamide, dimethyl terephthalate, isophthalic acid, phthalic anhydride, 1,4-cyclohexanedicarboxylic acid, dimethyl 1,4-cyclohexanedicarboxylate, dimer acid, maleic anhydride, trimethylolpropane, pentaerythritol, xylitol, sorbitol, mannitol, triethylamine bis-2-(hydroxypropyl)aniline, toluenediamine, aniline, isophoronediamine, diaminodicyclohexylmethane, glycolic acid, gluconic acid, DL-mandelic acid, citric acid, pyrimidine acid, alginic acid, salicylic acid, lauric acid, glycerol, trimethylhexanediamine or sorbic acid, or a combination of at least two thereof.

[0017] Preferably, the hydrophilic chain extender includes any one of trimethylolpropane, pentaerythritol, xylitol, sorbitol, mannitol, triethylamine bis-2-(hydroxypropyl)aniline, toluenediamine, aniline, isophoronediamine, diaminodicyclohexylmethane, glycolic acid, gluconic acid, DL-mandelic acid, citric acid, pyrimidine acid, alginic acid, salicylic acid, lauric acid, glycerol, trimethylhexanediamine or sorbic acid, or a combination of at least two thereof.

[0018] Preferably, the hydrophilic chain extender is any one of glycerol, trimethylhexanediamine or sorbic acid, or a combination of at least two thereof.

[0019] Preferably, the molecular weight of the polyoxypropylene triol is 200 to 8000 g / mol.

[0020] Preferably, the molecular weight of the propylene oxide-ethylene oxide copolyether triol is 300 to 7000 g / mol.

[0021] Preferably, the molecular weight of the polycaprolactone is 300-4000 g / mol.

[0022] Preferably, the molecular weight of the tetrahydroxy polyether polyol is 300 to 500 g / mol.

[0023] Preferably, the diamino polyether tetraol includes any one of ethylenediamine polyether tetraol, toluene diamine polyether tetraol, diaminodiphenylmethane polyether tetraol or meta-xylene diaminomethane polyether tetraol, or a combination of at least two thereof.

[0024] Preferably, the surfactant includes any one or a combination of at least two of polyoxyethylene ether, fatty alcohol polyoxyethylene ether, isomeric alcohol ether, propylene glycol block polyether, oleyl alcohol polyoxyethylene ether, polyethylene glycol, fatty acid polyoxyethylene ester, sorbitan stearate, Tween or tripropionin.

[0025] Preferably, the polyethylene glycol includes any one of polyethylene glycol 1000, polyethylene glycol 2000 or polyethylene glycol 3000, or a combination of at least two of them.

[0026] Preferably, the isomeric alcohol ether includes any one of isomeric decanol polyoxyethylene ether, isomeric undecanol polyoxyethylene ether or isomeric tridecanol polyoxyethylene ether, or a combination of at least two thereof.

[0027] Preferably, the surfactant is composed of a first surfactant, a second surfactant and a third surfactant; wherein the first surfactant includes any one of polyoxyethylene ether, fatty alcohol polyoxyethylene ether, isomeric alcohol ether, propylene glycol block polyether or oleyl alcohol polyoxyethylene ether, or a combination of at least two of them; the second surfactant includes polyethylene glycol and / or fatty acid polyoxyethylene ester; the third surfactant includes any one of stearin, Tween or tripropionin, or a combination of at least two of them.

[0028] Preferably, the mass ratio of the first surfactant, the second surfactant and the third surfactant is (2-4):(1-1.5):(0.5-1).

[0029] Preferably, the lubricant comprises any one of methylcellulose, carboxymethylcellulose, sodium carboxymethylcellulose, calcium carboxymethylcellulose, hydroxypropyl methylcellulose, hydroxymethylcellulose, hydroxyethyl cellulose, casein, calcium alginate, sodium alginate, gelatin, pectin, xanthan gum, carrageenan, xanthan gum, guar gum, gum arabic, hyaluronic acid, sodium hyaluronate, ceramide, niacinamide, chitosan or starch, or a combination of at least two thereof.

[0030] Preferably, the lubricant is any one of calcium alginate, sodium alginate, hyaluronic acid or sodium hyaluronate, or a combination of at least two thereof.

[0031] Preferably, the lubricant is composed of a first lubricant, a second lubricant and a third lubricant; wherein the first lubricant includes any one of methyl cellulose, carboxymethyl cellulose, sodium carboxymethyl cellulose, calcium carboxymethyl cellulose, hydroxypropyl methyl cellulose, hydroxymethyl cellulose, hydroxyethyl cellulose or casein, or a combination of at least two of them; the second lubricant includes any one of calcium alginate, sodium alginate, hyaluronic acid or sodium hyaluronate, or a combination of at least two of them; the third lubricant includes any one of gelatin, pectin, xanthan gum, carrageenan, xanthan gum, guar gum or gum arabic, or a combination of at least two of them.

[0032] Preferably, the mass ratio of the first lubricant, the second lubricant and the third lubricant is (2-3):(1-2):(0.1-1).

[0033] Preferably, the catalyst comprises any one of dimethylcyclohexylamine, ethanolamine, diethanolamine, triethanolamine, triisopropanolamine or methyldiethanolamine, or a combination of at least two thereof.

[0034] Preferably, the isocyanate prepolymer is obtained by reacting an isocyanate monomer and a polyol; wherein the polyol comprises a polyether polyol and / or a polyester polyol, preferably a polyether polyol.

[0035] Preferably, the polyether polyol includes any one of polyoxypropylene polyol, sorbitol-based polyether polyol, sucrose-based polyether polyol, trimethylolpropane-based polyether polyol or glyceryl-based polyether polyol, or a combination of at least two thereof.

[0036] Preferably, the raw materials for preparing the polyol include the following components by weight: 5 to 10 parts of low-molecular alcohol, 70 to 90 parts of epoxy compound, and 0.1 to 1 part of catalyst A.

[0037] Preferably, the small molecule alcohol includes any one or a combination of at least two of ethylene glycol, 1.3-propylene glycol, 1,3-butylene glycol, glycerol, trimethylolpropane, 1,4-butylene glycol, 1,6-hexanediol, neopentyl glycol, diethylene glycol, methylpentanediol, sucrose or sorbitol, preferably a combination of at least two of ethylene glycol, glycerol, trimethylolpropane, diethylene glycol, sucrose or sorbitol.

[0038] Preferably, the epoxy compound comprises ethylene oxide and / or propylene oxide, preferably a combination of ethylene oxide and propylene oxide.

[0039] Preferably, the catalyst A comprises potassium hydroxide and / or sodium hydroxide. Preferably, the raw materials for preparing the isocyanate prepolymer comprise the following components by weight: 40-50 parts of isocyanate monomer, 50-60 parts of polyether polyol, 0.1-1 parts of catalyst B, 0-1 parts of stabilizer, 0-5 parts of small molecule chain extender and 0-5 parts of cross-linking agent.

[0040] Preferably, the isocyanate monomer includes any one or a combination of at least two of toluene diisocyanate, diphenylmethane diisocyanate, naphthalene diisocyanate, p-phenylene diisocyanate, dimethyl diphenyl diisocyanate, polymethylene polyphenyl isocyanate, 1,6-hexamethylene diisocyanate, trimethyl-1,6-hexamethylene diisocyanate, xylylene diisocyanate, tetramethyl metaxylylene diisocyanate, isophorone diisocyanate, 1,4-cyclohexane diisocyanate, dicyclohexylmethane diisocyanate, methylcyclohexyl diisocyanate, cyclohexane dimethylene diisocyanate or norbornane diisocyanate.

[0041] Preferably, the catalyst B comprises any one or a combination of at least two of dibutyltin dilaurate, stannous octoate, dibutyltin diacetate, triethylenediamine, bis(dimethylaminoethyl) ether, N-methylmorpholine or tetramethylethylenediamine.

[0042] Preferably, the stabilizer includes any one of 2,6-di-tert-butyl-p-cresol, pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, 2-hydroxy-4-methoxybenzophenone or 2-(2H-benzotriazol-2-yl)-4,6-di-tert-amylphenol or a combination of at least two thereof.

[0043] Preferably, the small molecule chain extender includes any one or a combination of at least two of 1,4-butanediol, ethylene glycol, diethylene glycol, 1,6-hexanediol, neopentyl glycol, ethylenediamine, diethylenediamine or isophoronediamine, preferably a combination of at least two of 1,4-butanediol, ethylene glycol, 1,6-hexanediol or neopentyl glycol.

[0044] Preferably, the crosslinking agent comprises any one of glycerol, trimethylolpropane, pentaerythritol, triethanolamine, triethylenetetramine or tetraethylenepentamine, or a combination of at least two of them, preferably a combination of at least two of trimethylolpropane, triethanolamine, triethylenetetramine or tetraethylenepentamine.

[0045] Preferably, the isocyanate prepolymer is prepared by the following steps:

[0046] A small molecule alcohol, an epoxy compound and a catalyst A are polymerized to obtain a polyether polyol;

[0047] The polyether polyol, part of the isocyanate monomer, catalyst B and stabilizer are mixed to carry out a first reaction to obtain a reaction solution A; the reaction solution A and the remaining isocyanate monomer are mixed to carry out a second reaction to obtain a preliminary isocyanate prepolymer;

[0048] The preliminary isocyanate prepolymer is mixed with a small molecule chain extender and / or a cross-linking agent, and subjected to a third reaction to obtain the isocyanate prepolymer.

[0049] Preferably, in the process of preparing the polyol, the polymerization reaction temperature is 120-160° C., the polymerization reaction pressure is 0.2-0.4 MPa, and the polymerization reaction time is 4-8 h.

[0050] Preferably, the part of isocyanate monomers accounts for 30-50% of the total mass of the isocyanate monomers.

[0051] Preferably, the temperature of the first reaction is 70-75° C., and the time is 1-3 hours.

[0052] Preferably, the NCO content of the prepolymer in the reaction solution A obtained in the first reaction is 11-14%.

[0053] Preferably, the temperature of the second reaction is 75-80° C. and the time is 0.5-1.5 h.

[0054] Preferably, the NCO content of the preliminary isocyanate prepolymer obtained by the second reaction is 6-9%.

[0055] Preferably, the temperature of the third reaction is 60-70° C., and the time is 0.5-1.5 h.

[0056] Preferably, the NCO content of the isocyanate prepolymer obtained by the third reaction is 6-8%.

[0057] In a second aspect, the present invention provides a method for preparing a foam stock solution for absorbing thick exudate as described in the first aspect, the preparation method comprising the following steps:

[0058] Weigh a hydrophilic chain extender, a surfactant, a lubricant, a catalyst and water according to the formula, mix and stir to obtain a stock solution A;

[0059] The isocyanate prepolymer is weighed according to the formula amount, mixed and stirred to obtain stock solution B.

[0060] Preferably, in the preparation of the stock solution A, the temperature of the mixing and stirring is 10 to 30° C., and the rotation speed of the mixing and stirring is 100 to 500 rpm.

[0061] Preferably, in the preparation of the stock solution B, the temperature of the mixing and stirring is 30-40° C., and the rotation speed of the mixing and stirring is 100-500 rpm.

[0062] In a third aspect, the present invention provides a finger-shaped channel polyurethane foam, which is formed by mixing stock solution A and stock solution B in the foam stock solution for absorbing thick exudate as described in the first aspect, and then applying and foaming.

[0063] Preferably, the polyurethane foam is a special foam with a finger-like pore structure.

[0064] Preferably, the average pore diameter of the polyurethane foam is 150 μm or more, preferably 200 to 550 μm, and more preferably 350 to 450 μm.

[0065] Preferably, the surface open cell ratio of the polyurethane foam is 80% or more, preferably 85 to 95%, and more preferably 87 to 93%.

[0066] Preferably, the density of the polyurethane foam is 80 kg / m 3 Above, preferably 85 to 120 kg / m 3 More preferably, 95 to 110 kg / m 3 .

[0067] Preferably, when the viscosity of the absorbed liquid is 100 to 300 mPa·s, the liquid absorption rate of the polyurethane foam is 0.050 mL / s or more, preferably 0.100 mL / s or more, and more preferably 0.200 mL / s or more;

[0068] Preferably, when the viscosity of the absorbed liquid is 300 to 500 mPa·s, the liquid absorption rate of the polyurethane foam is 0.015 mL / s or more, preferably 0.030 mL / s or more, and more preferably 0.040 mL / s or more.

[0069] In a fourth aspect, the present invention provides a method for preparing the polyurethane foam as described in the third aspect, the method for preparing the polyurethane foam comprising the following steps:

[0070] The stock solution A and the stock solution B are mixed and stirred, and then extruded at a constant flow rate to obtain an extruded liquid;

[0071] The extruded liquid is coated to form a flat foaming liquid, which is then dried to obtain a polyurethane foam.

[0072] Preferably, the mixing and stirring has a rotation speed of 2000 to 5000 rpm, preferably 2500 to 4500 rpm.

[0073] Preferably, the specific steps of coating include the following steps:

[0074] The extruded liquid is passed through a roller blade coater to obtain a flat foaming liquid, which is then covered with a silicon-treated release paper, and the pulling speeds of the foaming liquid and the release paper are kept synchronous.

[0075] Preferably, the drying is carried out in a forced air oven at a drying temperature of 80-200°C.

[0076] In a fifth aspect, the present invention provides a use of the foam stock solution for absorbing thick exudate as described in the first aspect, or the polyurethane foam as described in the third aspect in preparing a medical wound dressing or in preparing a core layer of a sanitary napkin.

[0077] Compared with the prior art, the present invention has the following beneficial effects:

[0078] (1) The foam stock solution for absorbing thick exudate of the present invention comprises a stock solution A formed by a hydrophilic chain extender, a surfactant, water, a lubricant and a catalyst in a specific ratio and composition, and a stock solution B made of an isocyanate prepolymer. The two are mixed and stirred, and then coated and foamed to finally form the desired polyurethane foam. In the process of phase transformation of the polyurethane foam, special pores with a finger-like pore structure are formed, which has abundant pores and can provide a rapid mass transfer channel for medium migration.

[0079] (2) The polyurethane foam of the present invention is a special foam with a finger-like pore structure, which can provide a fast mass transfer channel for medium migration. This structure is conducive to the rapid passage of substances, thereby improving the mass transfer performance of the polyurethane foam.

[0080] (3) The pores of the polyurethane foam of the present invention are direct and well connected, so that the permeability of the polyurethane foam layer is guaranteed and a higher flux can be exhibited.

[0081] (4) The pore size distribution of the polyurethane foam of the present invention is relatively wide, which makes the polyurethane foam more adaptable in different application scenarios. Different pore sizes can meet the mass transfer requirements of particles of different sizes.

[0082] (5) The polyurethane foam of the present invention can be used to prepare medical wound dressings for absorbing thick exudates, especially for targeted treatment of chronic wounds containing a large amount of protein, cell fragments and necrotic tissue, which leads to increased viscosity of wound exudates, significantly improving the liquid absorption performance and biocompatibility of the polyurethane foam, and further improving the degree and speed of wound and wound healing.

[0083] (6) The polyurethane foam of the present invention can be used as the core layer of a sanitary napkin, and has the advantages of strong hemophilicity to menstrual blood, strong fluid conductivity, high fluid retention capacity, low blood reverse osmosis rate, and good surface dryness. BRIEF DESCRIPTION OF THE DRAWINGS

[0084] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0085] Figure 1 The figure is a schematic structural diagram of roller coating in the preparation process of the polyurethane foam of the present invention.

[0086] Among them, 1 represents the coating roller, 2 represents the foaming liquid, 3 represents the release paper, and 4 represents the water platform.

[0087] Figure 2 This is a scanning electron microscope image of the polyurethane foam provided in Example 1.

[0088] Figure 3 This is a scanning electron microscope image of the polyurethane foam provided in Example 2.

[0089] Figure 4 This is a scanning electron microscope image of the polyurethane foam provided in Example 3.

[0090] Figure 5 This is a scanning electron microscope image of the polyurethane foam provided in Example 4.

[0091] Figure 6 This is a scanning electron microscope image of the polyurethane foam provided for Comparative Example 1.

[0092] Fig. 7A This is a contact angle photograph of the polyurethane foam provided in Example 1 in a 1% CMC A solution test.

[0093] Figure 7B This is a contact angle photograph of the polyurethane foam provided in Example 1 in a 1.5% CMC A solution test.

[0094] Fig. 8A This is a contact angle photograph of the polyurethane foam provided in Example 2 in a 1% CMC A solution test.

[0095] Figure 8B This is a contact angle photograph of the polyurethane foam provided in Example 2 in a 1.5% CMC A solution test.

[0096] Fig.9A This is a contact angle photograph of the polyurethane foam provided in Example 3 in a 1% CMC A solution test.

[0097] Fig. 9BThis is a contact angle photograph of the polyurethane foam provided in Example 3 in a 1.5% CMC A solution test.

[0098] Fig. 10A This is a contact angle photograph of the polyurethane foam provided in Example 4 in a 1% CMC A solution test.

[0099] Fig. 10B This is a contact angle photograph of the polyurethane foam provided in Example 4 in a 1.5% CMC A solution test.

[0100] Fig.11A This is a contact angle photograph of the polyurethane foam provided for Comparative Example 1 in a 1% CMC A solution test.

[0101] Fig. 11B This is a contact angle photograph of the polyurethane foam provided for Comparative Example 1 in a 1.5% CMC A solution test. DETAILED DESCRIPTION

[0102] To make the purpose, technical solution and advantages of the present invention clearer, the technical solution in the embodiment of the present invention will be clearly and completely described below in combination with the embodiment of the present invention. Obviously, the described embodiment is a part of the embodiment of the present invention, but not all of the embodiments. The components of the embodiment of the present invention can be arranged and designed in various different configurations.

[0103] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0104] In a first aspect, the present invention provides a foam stock solution for absorbing thick exudate, wherein the foam stock solution for absorbing thick exudate comprises stock solution A and stock solution B in parts by weight;

[0105] The stock solution A comprises, by weight: 1 to 20 parts of a hydrophilic chain extender, 1 to 10 parts of a surfactant, 1 to 10 parts of a lubricant, 0.1 to 2 parts of a catalyst and 50 to 99 parts of water;

[0106] Wherein, the stock solution B comprises, by weight: 50 to 200 parts of isocyanate prepolymer.

[0107] The foam stock solution for absorbing thick exudate of the present invention comprises a stock solution A formed by a hydrophilic chain extender, a surfactant, water, a lubricant and a catalyst in a specific ratio and composition, and a stock solution B made of an isocyanate prepolymer. After the two are mixed and stirred, they are coated and foamed to finally form the desired polyurethane foam, and the special pores of the finger-like pore structure are formed during the phase transformation of the polyurethane foam. The foam provided by the present invention has finger-like pores in structure, that is, the foam pores are finger-shaped in the vertical cross section, and the pore diameter is small on the side close to the human body. The finger-like pore structure has the following characteristics:

[0108] I. Rich mass transfer channels: The finger-like pore structure is formed during the phase transformation of polyurethane foam, and has abundant pores, which can provide fast mass transfer channels for medium migration. This structure is conducive to the rapid passage of substances, thereby improving the mass transfer performance of polyurethane foam.

[0109] Ⅱ. Good permeability: The pores of the finger-like pore structure are relatively direct and well connected, which ensures the permeability of the polyurethane foam layer. Generally speaking, polymers with finger-like pore structures can exhibit higher flux.

[0110] III. Wide pore size distribution: The pore size distribution of the finger-like pore structure is relatively wide, which makes the polyurethane foam more adaptable in different application scenarios. Different pore sizes can meet the mass transfer requirements of particles of different sizes.

[0111] It should be noted that the factors that affect the liquid absorption effect of foam mainly include surface pore size, hydrophilicity (water contact angle), surface porosity, density, bubble uniformity and morphological structure.

[0112] As an optional embodiment, the content of the hydrophilic chain extender in the stock solution A is 1 to 20 parts, for example, it can be 1 part, 2 parts, 3 parts, 4 parts, 5 parts, 6 parts, 7 parts, 8 parts, 9 parts, 10 parts, 11 parts, 12 parts, 13 parts, 14 parts, 15 parts, 16 parts, 17 parts, 18 parts, 19 parts, 20 parts, etc.

[0113] It should be noted that the hydrophilicity (water contact angle) of the polyurethane foam is determined by the composition and content of the hydrophilic chain extender in the formula; in addition, the density is mainly determined by the hydrophilic chain extender and the lubricant. Therefore, in the present invention, the content of the hydrophilic chain extender is set to 1 to 20 parts, preferably 5 to 15 parts, and more preferably 10 to 12 parts.

[0114] As an optional embodiment, the content of the surfactant in the stock solution A is 1 to 10 parts, for example, it can be 1 part, 1.5 parts, 2 parts, 2.5 parts, 3 parts, 3.5 parts, 4 parts, 4.5 parts, 5 parts, 5.5 parts, 6 parts, 6.5 parts, 7 parts, 7.5 parts, 8 parts, 8.5 parts, 9 parts, 9.5 parts, 10 parts, etc.

[0115] It should be noted that how the finger-like pore structure is formed during the foaming process is mainly determined by the composition and content of the surfactant; in addition, the uniformity of the bubbles is mainly determined by the ratio of the surfactant to the water content; and the surface open porosity is determined by the composition and content of the surfactant. Therefore, in the present invention, the content of the surfactant is set to 1 to 10 parts, preferably 3 to 8 parts, and more preferably 4 to 6 parts.

[0116] As an optional embodiment, the content of lubricant in the stock solution A is 1 to 10 parts, for example, it can be 1 part, 1.5 parts, 2 parts, 2.5 parts, 3 parts, 3.5 parts, 4 parts, 4.5 parts, 5 parts, 5.5 parts, 6 parts, 6.5 parts, 7 parts, 7.5 parts, 8 parts, 8.5 parts, 9 parts, 9.5 parts, 10 parts, etc.

[0117] It should be noted that the density is mainly determined by the hydrophilic chain extender and the lubricant. Therefore, in the present invention, the content of the hydrophilic chain extender is set to 1 to 10 parts, preferably 2 to 6 parts, and more preferably 3 to 5 parts.

[0118] As an optional embodiment, the content of the catalyst in the stock solution A is 0.1 to 2 parts, for example, it can be 0.1 part, 0.2 part, 0.3 part, 0.4 part, 0.5 part, 0.6 part, 0.7 part, 0.8 part, 0.9 part, 1 part, 1.1 part, 1.2 parts, 1.3 parts, 1.4 parts, 1.5 parts, 1.6 parts, 1.7 parts, 1.8 parts, 1.9 parts, 2 parts, etc., and more preferably 0.5 to 1.5 parts.

[0119] As an optional embodiment, the water content in the stock solution A is 50 to 99 parts, for example, it can be 50 parts, 52 parts, 54 parts, 55 parts, 56 parts, 58 parts, 60 parts, 62 parts, 64 parts, 65 parts, 66 parts, 68 parts, 70 parts, 72 parts, 74 parts, 75 parts, 76 parts, 78 parts, 80 parts, 82 parts, 84 parts, 85 parts, 86 parts, 88 parts, 90 parts, 92 parts, 94 parts, 95 parts, 96 parts, 98 parts, 99 parts, etc.

[0120] It should be noted that the surface opening pore size of the polyurethane foam is determined by the water content in the formula; in addition, the uniformity of the bubbles is mainly determined by the ratio of the surfactant to the water content. Therefore, in the present invention, the water content is set to 50 to 99 parts, preferably 60 to 90 parts, and more preferably 70 to 80 parts.

[0121] As an optional embodiment, in the stock solution B, the content of isocyanate prepolymer is 50 to 200 parts, for example, it can be 50 parts, 55 parts, 60 parts, 65 parts, 70 parts, 75 parts, 80 parts, 85 parts, 90 parts, 95 parts, 100 parts, 105 parts, 110 parts, 105 parts, 120 parts, 125 parts, 130 parts, 135 parts, 140 parts, 145 parts, 150 parts, 155 parts, 160 parts, 165 parts, 170 parts, 175 parts, 180 parts, 185 parts, 190 parts, 195 parts, 200 parts, etc., preferably 100 to 150 parts, and more preferably 110 to 130 parts.

[0122] As a preferred embodiment, the foam stock solution for absorbing thick exudate includes stock solution A and stock solution B in parts by weight; wherein, the stock solution A includes, in parts by weight: 5 to 15 parts of hydrophilic chain extender, 3 to 8 parts of surfactant, 2 to 6 parts of lubricant, 0.1 to 2 parts of catalyst and 60 to 90 parts of water; wherein, the stock solution B includes, in parts by weight: 100 to 150 parts of isocyanate prepolymer.

[0123] As a more preferred embodiment, the foam stock solution for absorbing thick exudate includes stock solution A and stock solution B in parts by weight; wherein, the stock solution A includes, in parts by weight: 10 to 12 parts of hydrophilic chain extender, 4 to 6 parts of surfactant, 3 to 5 parts of lubricant, 0.5 to 1.5 parts of catalyst and 70 to 80 parts of water; wherein, the stock solution B includes, in parts by weight: 110 to 130 parts of isocyanate prepolymer.

[0124] As an optional embodiment, the hydrophilic chain extender includes polyoxypropylene triol, oxypropylene-oxyethylene copolyether triol, polycaprolactone, fructose, lactose, maltose, maltitol, trehalose, sucrose, tetrahydroxy polyether polyol, pentaerythritol polyether polyol, diamino polyether tetraol, polyether pentaol, polyether hexaol, polystyrene polyol, castor oil and castor oil derivative polyol, soybean oil polyol, palm oil polyol, rosin ester polyol, 4,4'-methylenebis(3-chloro-2,6-diethylaniline), 4,4'-methylenebis(2,6-diethyl)aniline, 4,4'-methylenebis(2-methyl-6-diethylaniline), 4,4'-methylenebis(2-diethylaniline), 4,4'-methylenebis(2,6-diisopropyl)aniline, 4,4 '-Methylenebis(2-isopropyl-6-methyl)aniline, 2,4-diamino-3,5-dimethylthiochlorobenzene, propylene glycol bis(4-benzoate), 3,5-diamino-4-chlorobenzoic acid isobutyl ester, coconut diethanolamide, dimethyl terephthalate, isophthalic acid, phthalic anhydride, 1,4-cyclohexanedicarboxylic acid, dimethyl 1,4-cyclohexanedicarboxylate, dimer acid, maleic anhydride, trimethylolpropane, pentaerythritol, xylitol, sorbitol, mannitol, triethylamine bis-2-(hydroxypropyl)aniline, toluenediamine, aniline, isophoronediamine, diaminodicyclohexylmethane, glycolic acid, gluconic acid, DL-mandelic acid, citric acid, pyrimidine acid, alginic acid, salicylic acid, lauric acid, glycerol, trimethylhexanediamine or sorbic acid, any one or a combination of at least two thereof.

[0125] As a preferred embodiment, the hydrophilic chain extender includes any one of trimethylolpropane, pentaerythritol, xylitol, sorbitol, mannitol, triethylamine bis-2-(hydroxypropyl)aniline, toluenediamine, aniline, isophoronediamine, diaminodicyclohexylmethane, glycolic acid, gluconic acid, DL-mandelic acid, citric acid, pyrimidine acid, alginic acid, salicylic acid, lauric acid, glycerol, trimethylhexanediamine or sorbic acid, or a combination of at least two thereof.

[0126] As a more preferred embodiment, the hydrophilic chain extender is any one of glycerol, trimethylhexanediamine or sorbic acid, or a combination of at least two thereof.

[0127] As an optional embodiment, the molecular weight of the polyoxypropylene triol is 200 to 8000 g / mol, for example, it can be 200 g / mol, 300 g / mol, 400 g / mol, 500 g / mol, 600 g / mol, 800 g / mol, 1000 g / mol, 1500 g / mol, 2000 g / mol, 2500 g / mol, 3000 g / mol, 3500 g / mol, 4000 g / mol, 4500 g / mol, 5000 g / mol, 5500 g / mol, 6000 g / mol, 6500 g / mol, 7000 g / mol, 8000 g / mol, etc.

[0128] As an optional embodiment, the molecular weight of the propylene oxide-ethylene oxide copolyether triol is 300-7000 g / mol, for example, it can be 300 g / mol, 400 g / mol, 500 g / mol, 600 g / mol, 800 g / mol, 1000 g / mol, 1500 g / mol, 2000 g / mol, 2500 g / mol, 3000 g / mol, 3500 g / mol, 4000 g / mol, 4500 g / mol, 5000 g / mol, 5500 g / mol, 6000 g / mol, 6500 g / mol, 7000 g / mol, etc.

[0129] As an optional embodiment, the molecular weight of the polycaprolactone is 300-4000 g / mol, for example, it can be 300 g / mol, 400 g / mol, 500 g / mol, 600 g / mol, 800 g / mol, 1000 g / mol, 1500 g / mol, 2000 g / mol, 2500 g / mol, 3000 g / mol, 3500 g / mol, 4000 g / mol, etc.

[0130] As an optional embodiment, the molecular weight of the tetrahydroxy polyether polyol is 300-500 g / mol, for example, it can be 300 g / mol, 320 g / mol, 340 g / mol, 350 g / mol, 360 g / mol, 380 g / mol, 400 g / mol, 420 g / mol, 440 g / mol, 460 g / mol, 480 g / mol, 500 g / mol, etc.

[0131] As an optional embodiment, the diamino polyether tetraol includes any one of ethylenediamine polyether tetraol, toluene diamine polyether tetraol, diaminodiphenylmethane polyether tetraol or meta-xylene diaminomethane polyether tetraol, or a combination of at least two thereof.

[0132] As an optional embodiment, the surfactant includes any one of polyoxyethylene ether, fatty alcohol polyoxyethylene ether, isomeric alcohol ether, propylene glycol block polyether, oleyl alcohol polyoxyethylene ether, polyethylene glycol, fatty acid polyoxyethylene ester, sorbitan stearate, Tween or tripropionin, or a combination of at least two thereof.

[0133] As an optional embodiment, the polyethylene glycol includes any one of polyethylene glycol 1000, polyethylene glycol 2000 or polyethylene glycol 3000, or a combination of at least two of them.

[0134] As an optional embodiment, the isomeric alcohol ether includes any one of isomeric decanol polyoxyethylene ether, isomeric undecanol polyoxyethylene ether or isomeric tridecanol polyoxyethylene ether, or a combination of at least two thereof.

[0135] As a preferred embodiment, the surfactant is composed of a first surfactant, a second surfactant and a third surfactant;

[0136] Among them, the first surfactant includes any one of polyoxyethylene ether, fatty alcohol polyoxyethylene ether, isomeric alcohol ether, propylene glycol block polyether or oleyl alcohol polyoxyethylene ether, or a combination of at least two of them; the second surfactant includes polyethylene glycol and / or fatty acid polyoxyethylene ester; the third surfactant includes any one of sorbitan stearate, Tween or tripropionin, or a combination of at least two of them.

[0137] It should be noted that the surfactant is preferably composed of the above-mentioned specific first surfactant, second surfactant and third surfactant, which can further improve the material migration efficiency, mass transfer performance and permeability of the polyurethane foam. Wherein, as an optional embodiment, the surfactant includes but is not limited to being composed of polyoxyethylene ether, polyethylene glycol and stearic sorbitan, or being composed of fatty alcohol polyoxyethylene ether, polyethylene glycol and Tween, or being composed of isomeric alcohol ether, fatty acid polyoxyethylene ester and tripropionin, or being composed of propylene glycol block polyether, fatty acid polyoxyethylene ester and tripropionin, etc.

[0138] It should be noted that the selection of the first surfactant, the second surfactant and the third surfactant compound composition can maintain the pore structure (such as pore size), liquid absorption rate and hydrophilicity of the prepared polyurethane foam in the best balance state. Otherwise, if some non-preferred surfactants are selected, the pore size of the polyurethane foam may be too large, but the liquid absorption rate will decrease, and the hydrophilicity will be poor; or some non-preferred surfactants may increase the hydrophilicity of the polyurethane foam, but the pore size of the foam is too small, which will also cause the liquid absorption rate to decrease.

[0139] As a preferred embodiment, the mass ratio of the first surfactant, the second surfactant and the third surfactant is (2-4):(1-1.5):(0.5-1);

[0140] Among them, "2~4" can be, for example, 2, 2.2, 2.4, 2.5, 2.6, 2.8, 3, 3.2, 3.4, 3.6, 3.8, 4, etc.; among them, "1~1.5" can be, for example, 1, 1.1, 1.2, 1.3, 1.4, 1.5, etc.; among them, "0.5~1" can be, for example, 0.5, 0.6, 0.7, 0.8, 0.9, 1, etc.

[0141] As an optional embodiment, the lubricant includes any one of methylcellulose, carboxymethylcellulose, sodium carboxymethylcellulose, calcium carboxymethylcellulose, hydroxypropyl methylcellulose, hydroxymethylcellulose, hydroxyethyl cellulose, casein, calcium alginate, sodium alginate, gelatin, pectin, xanthan gum, carrageenan, xanthan gum, guar gum, gum arabic, hyaluronic acid, sodium hyaluronate, ceramide, niacinamide, chitosan or starch, or a combination of at least two thereof.

[0142] As a preferred embodiment, the lubricant is any one of calcium alginate, sodium alginate, hyaluronic acid or sodium hyaluronate, or a combination of at least two thereof.

[0143] As an optional embodiment, the lubricant is composed of a first lubricant, a second lubricant and a third lubricant;

[0144] Among them, the first lubricant includes any one of methyl cellulose, carboxymethyl cellulose, sodium carboxymethyl cellulose, calcium carboxymethyl cellulose, hydroxypropyl methyl cellulose, hydroxymethyl cellulose, hydroxyethyl cellulose or casein, or a combination of at least two of them; the second lubricant includes any one of calcium alginate, sodium alginate, hyaluronic acid or sodium hyaluronate, or a combination of at least two of them; the third lubricant includes any one of gelatin, pectin, xanthan gum, carrageenan, xanthan gum, guar gum or gum arabic, or a combination of at least two of them.

[0145] It should be noted that the lubricant is preferably composed of the above-mentioned specific first lubricant, second lubricant and third lubricant, which can further improve the material migration efficiency, mass transfer performance and permeability of the polyurethane foam. Among them, as optional embodiments, it includes but is not limited to methyl cellulose, calcium alginate and gelatin, or carboxymethyl cellulose, sodium alginate and pectin, or hydroxyethyl cellulose, hyaluronic acid and xanthan gum, or hydroxyethyl cellulose, sodium alginate, hyaluronic acid, gum arabic, or casein, sodium alginate, sodium hyaluronate, gum arabic, etc.

[0146] It should be noted that the selection of the first lubricant, the second lubricant and the third lubricant compound composition can maintain the pore structure (such as pore size), liquid absorption rate and hydrophilicity of the prepared polyurethane foam in the best balance state. Otherwise, if some non-preferred lubricants are selected, the pore size of the polyurethane foam may be too large, but the liquid absorption rate will decrease, and the hydrophilicity will be poor; or some non-preferred lubricants may increase the hydrophilicity of the polyurethane foam, but the pore size of the foam is too small, which will also cause the liquid absorption rate to decrease.

[0147] As an optional embodiment, the mass ratio of the first lubricant, the second lubricant and the third lubricant is (2-3):(1-2):(0.1-1);

[0148] Among them, "2~3" can be, for example, 2, 2.2, 2.4, 2.5, 2.6, 2.8, 3, etc.; among them, "1~2" can be, for example, 1, 1.2, 1.4, 1.5, 1.6, 1.8, 2, etc.; among them, "0.1~1" can be, for example, 0.1, 0.2, 0.4, 0.5, 0.6, 0.8, 1, etc.

[0149] As an optional embodiment, the catalyst includes any one of dimethylcyclohexylamine, ethanolamine, diethanolamine, triethanolamine, triisopropanolamine or methyldiethanolamine, or a combination of at least two thereof.

[0150] As an optional implementation, the isocyanate prepolymer is obtained by reacting an isocyanate monomer and a polyol; wherein the polyol includes a polyether polyol and / or a polyester polyol.

[0151] As a preferred embodiment, the polyol is a polyether polyol.

[0152] As a preferred embodiment, the polyether polyol includes any one of polyoxypropylene polyol, sorbitol-based polyether polyol, sucrose-based polyether polyol, trimethylolpropane-based polyether polyol or glyceryl-based polyether polyol, or a combination of at least two thereof.

[0153] As an optional implementation, the polyether polyol is obtained by polymerization reaction of a small molecule alcohol and an epoxy compound.

[0154] As an optional embodiment, the raw materials for preparing the polyol include the following components in parts by weight: 5 to 10 parts of small molecule alcohol, 70 to 90 parts of epoxy compound, and 0.1 to 1 part of catalyst A.

[0155] As an optional embodiment, in the raw material for preparing the polyol, the content of the small molecule alcohol is 5 to 10 parts, for example, 5 parts, 6 parts, 7 parts, 8 parts, 9 parts, 10 parts, etc.

[0156] As an optional embodiment, in the raw materials for preparing the polyol, the small molecule alcohol includes any one of ethylene glycol, 1.3-propylene glycol, 1,3-butylene glycol, glycerol, trimethylolpropane, 1,4-butylene glycol, 1,6-hexanediol, neopentyl glycol, diethylene glycol, methyl pentanediol, sucrose or sorbitol, or a combination of at least two of them.

[0157] As a preferred embodiment, in the raw materials for preparing the polyol, the small molecule alcohol is a combination of at least two of ethylene glycol, glycerol, trimethylolpropane, diethylene glycol, sucrose or sorbitol.

[0158] As an optional embodiment, the content of epoxy compound in the raw material for preparing the polyol is 70 to 90 parts, for example, it can be 70 parts, 72 parts, 74 parts, 75 parts, 76 parts, 78 parts, 80 parts, 82 parts, 84 parts, 85 parts, 86 parts, 88 parts, 90 parts, etc.

[0159] As an optional embodiment, in the raw materials for preparing the polyol, the epoxy compound includes ethylene oxide and / or propylene oxide.

[0160] As a preferred embodiment, in the raw materials for preparing the polyol, the epoxy compound is a combination of ethylene oxide and propylene oxide.

[0161] As an optional embodiment, the content of catalyst A in the raw material for preparing the polyol is 0.1 to 1 part, for example, it can be 0.1 part, 0.2 part, 0.3 part, 0.4 part, 0.5 part, 0.6 part, 0.7 part, 0.8 part, 0.9 part, 1 part, etc.

[0162] As an optional embodiment, in the raw materials for preparing the polyol, the catalyst A includes potassium hydroxide and / or sodium hydroxide.

[0163] As an optional embodiment, the raw materials for preparing the isocyanate prepolymer include the following components in parts by weight: 40-50 parts of isocyanate monomer, 50-60 parts of polyether polyol, 0.1-1 part of catalyst B, 0-1 part of stabilizer, 0-5 parts of small molecule chain extender and 0-5 parts of cross-linking agent.

[0164] As an optional embodiment, the content of isocyanate monomer in the raw material for preparing the isocyanate prepolymer is 40 to 50 parts, for example, it can be 40 parts, 41 parts, 42 parts, 43 parts, 44 parts, 45 parts, 46 parts, 47 parts, 48 ​​parts, 49 parts, 50 parts, etc.

[0165] As an optional embodiment, the isocyanate monomer includes any one of toluene diisocyanate, diphenylmethane diisocyanate, naphthalene diisocyanate, p-phenylene diisocyanate, dimethyl diphenyl diisocyanate, polymethylene polyphenyl isocyanate, 1,6-hexamethylene diisocyanate, trimethyl-1,6-hexamethylene diisocyanate, xylene diisocyanate, tetramethyl metaxylene diisocyanate, isophorone diisocyanate, 1,4-cyclohexane diisocyanate, dicyclohexylmethane diisocyanate, methylcyclohexyl diisocyanate, cyclohexane dimethylene diisocyanate or norbornane diisocyanate, or a combination of at least two thereof.

[0166] As an optional embodiment, in the raw material for preparing the isocyanate prepolymer, the content of the polyether polyol is 50 to 60 parts, for example, it can be 50 parts, 51 parts, 52 parts, 53 parts, 54 parts, 55 parts, 56 parts, 57 parts, 58 parts, 59 parts, 60 parts, etc.

[0167] As an optional embodiment, in the raw materials for preparing the isocyanate prepolymer, the content of the catalyst B is 0.1 to 1 part, for example, it can be 0.1 part, 0.2 part, 0.3 part, 0.4 part, 0.5 part, 0.6 part, 0.7 part, 0.8 part, 0.9 part, 1 part, etc.

[0168] As an optional embodiment, the catalyst B includes any one of dibutyltin dilaurate, stannous octoate, dibutyltin diacetate, triethylenediamine, bis(dimethylaminoethyl) ether, N-methylmorpholine or tetramethylethylenediamine, or a combination of at least two thereof.

[0169] As an optional embodiment, the content of the stabilizer in the preparation raw materials of the isocyanate prepolymer is 0 to 1 part, for example, it can be 0.001 part, 0.005 part, 0.01 part, 0.05 part, 0.1 part, 0.2 part, 0.3 part, 0.4 part, 0.5 part, 0.6 part, 0.7 part, 0.8 part, 0.9 part, 1 part, etc.

[0170] As an optional embodiment, the stabilizer includes any one of 2,6-di-tert-butyl-p-cresol, pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, 2-hydroxy-4-methoxybenzophenone or 2-(2H-benzotriazol-2-yl)-4,6-di-tert-amylphenol or a combination of at least two thereof.

[0171] As an optional embodiment, in the preparation raw material of the isocyanate prepolymer, the content of the small molecule chain extender is 0 to 5 parts, for example, it can be 0 part, 0.001 part, 0.005 part, 0.01 part, 0.05 part, 0.1 part, 0.2 part, 0.3 part, 0.4 part, 0.5 part, 0.6 part, 0.7 part, 0.8 part, 0.9 part, 1 part, 2 parts, 3 parts, 4 parts, 5 parts, etc.

[0172] As an optional embodiment, the small molecule chain extender includes any one of 1,4-butanediol, ethylene glycol, diethylene glycol, 1,6-hexanediol, neopentyl glycol, ethylenediamine, diethylenediamine or isophoronediamine, or a combination of at least two thereof.

[0173] As a preferred embodiment, in the raw materials for preparing the polyol, the small molecule chain extender is a combination of at least two of 1,4-butanediol, ethylene glycol, 1,6-hexanediol or neopentyl glycol.

[0174] As an optional embodiment, the content of the cross-linking agent in the preparation raw material of the isocyanate prepolymer is 0 to 5 parts, for example, it can be 0 part, 0.001 part, 0.005 part, 0.01 part, 0.05 part, 0.1 part, 0.2 part, 0.3 part, 0.4 part, 0.5 part, 0.6 part, 0.7 part, 0.8 part, 0.9 part, 1 part, 2 parts, 3 parts, 4 parts, 5 parts, etc.

[0175] As an optional embodiment, the cross-linking agent includes any one of glycerol, trimethylolpropane, pentaerythritol, triethanolamine, triethylenetetramine or tetraethylenepentamine, or a combination of at least two thereof.

[0176] As a preferred embodiment, in the raw materials for preparing the polyol, the cross-linking agent is a combination of at least two of trimethylolpropane, triethanolamine, triethylenetetramine or tetraethylenepentamine.

[0177] As an optional embodiment, the isocyanate prepolymer is prepared by the following steps:

[0178] A small molecule alcohol, an epoxy compound and a catalyst A are polymerized to obtain a polyether polyol;

[0179] The polyether polyol, part of the isocyanate monomer, catalyst B and stabilizer are mixed to carry out a first reaction to obtain a reaction solution A; the reaction solution A and the remaining isocyanate monomer are mixed to carry out a second reaction to obtain a preliminary isocyanate prepolymer;

[0180] The preliminary isocyanate prepolymer is mixed with a small molecule chain extender and / or a cross-linking agent, and subjected to a third reaction to obtain the isocyanate prepolymer.

[0181] It should be noted that the third reaction process can make the preliminary isocyanate prepolymer and the small molecule chain extender mixed and reacted, or make the preliminary isocyanate prepolymer and the cross-linking agent mixed and reacted, or make the preliminary isocyanate prepolymer, the small molecule chain extender and the cross-linking agent mixed and reacted together.

[0182] As an optional embodiment, in the process of preparing the polyether polyol, the temperature of the polymerization reaction is 120-160°C, for example, it can be 120°C, 125°C, 130°C, 135°C, 140°C, 145°C, 150°C, 155°C, 160°C, etc., the pressure of the polymerization reaction is 0.2-0.4MPa, for example, it can be 0.2MPa, 0.25MPa, 0.3MPa, 0.35MPa, 0.4MPa, etc., and the time of the polymerization reaction is 4-8h, for example, it can be 4h, 4.5h, 5h, 5.5h, 6h, 6.5h, 7h, 7.5h, 8h, etc.

[0183] As an optional embodiment, the portion of isocyanate monomers accounts for 30-50% of the total mass of the isocyanate monomers, for example, it can be 30%, 32%, 34%, 36%, 38%, 40%, 42%, 44%, 46%, 48%, 50%, etc.

[0184] As an optional embodiment, the temperature of the first reaction is 70-75°C, for example, 70°C, 71°C, 72°C, 73°C, 74°C, 75°C, etc., and the time is 1-3h, for example, 1.0h, 1.2h, 1.4h, 1.5h, 1.6h, 1.8h, 2h, etc.

[0185] As an optional embodiment, the NCO content of the prepolymer in the reaction solution A obtained in the first reaction is 11-14%, for example, 11%, 12%, 13%, 14%, etc.

[0186] As an optional embodiment, the temperature of the second reaction is 75-80°C, for example, 75°C, 76°C, 78°C, 79°C, 80°C, etc., and the time is 0.5-1.5h, for example, 0.5h, 0.7h, 0.9h, 1.0h, 1.1h, 1.3h, 1.5h, etc.

[0187] As an optional embodiment, the NCO content of the preliminary isocyanate prepolymer obtained by the second reaction is 6-9%, for example, 6%, 6.5%, 7%, 7.5%, 8%, 8.5%, 9%, etc.

[0188] As an optional embodiment, the temperature of the third reaction is 60-70°C, for example, it can be 60°C, 61°C, 62°C, 63°C, 64°C, 65°C, 66°C, 67°C, 68°C, 69°C, 70°C, etc., and the time is 0.5-1.5h, for example, it can be 0.5h, 0.6h, 0.7h, 0.8h, 1h, 1.2h, 1.4h, 1.5h, etc.

[0189] As an optional embodiment, the NCO content of the isocyanate prepolymer obtained by the third reaction is 6-8%, for example, 6%, 6.5%, 7%, 7.5%, 8%, etc.

[0190] In a second aspect, the present invention provides a method for preparing a foam stock solution for absorbing thick exudate as described in the first aspect, the preparation method comprising the following steps:

[0191] Weigh a hydrophilic chain extender, a surfactant, a lubricant, a catalyst and water according to the formula, mix and stir to obtain a stock solution A;

[0192] The isocyanate prepolymer is weighed according to the formula amount, mixed and stirred to obtain stock solution B.

[0193] As an optional embodiment, in the preparation of the stock solution A, the mixing and stirring temperature is 10-30°C, for example, it can be 10°C, 12°C, 14°C, 16°C, 18°C, 20°C, 22°C, 24°C, 26°C, 28°C, 30°C, etc., and the mixing and stirring speed is 100-500rpm, for example, it can be 100rpm, 150rpm, 200rpm, 250rpm, 300rpm, 350rpm, 400rpm, 450rpm, 500rpm, etc.

[0194] As an optional embodiment, in the preparation of the stock solution B, the mixing and stirring rotation speed is 100-500 rpm, for example, it can be 100 rpm, 150 rpm, 200 rpm, 250 rpm, 300 rpm, 350 rpm, 400 rpm, 450 rpm, 500 rpm, etc.

[0195] In a third aspect, the present invention provides a polyurethane foam, wherein the polyurethane foam is formed by mixing the stock solution A and the stock solution B in the foam stock solution for absorbing thick exudate as described in the first aspect, and then applying and foaming.

[0196] As an optional embodiment, the polyurethane foam is a special foam with a finger-like pore structure.

[0197] As an optional embodiment, the thickness of the polyurethane foam is 1 to 10 mm, for example, it can be 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, 3.5 mm, 4 mm, 4.5 mm, 5 mm, 5.5 mm, 6 mm, 6.5 mm, 7 mm, 7.5 mm, 8 mm, 8.5 mm, 9 mm, 9.5 mm, 10 mm, etc.

[0198] As an optional embodiment, the average pore size of the polyurethane foam is greater than 150μm, for example, it can be 150μm, 200μm, 250μm, 300μm, 350μm, 400μm, 450μm, 500μm, 550μm, 600μm, 650μm, 700μm, etc., preferably 200-550μm, and more preferably 350-450μm.

[0199] As an optional embodiment, the surface open porosity of the polyurethane foam is greater than 80%, for example, it can be 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, etc., preferably 85-95%, and more preferably 87-93%.

[0200] As an optional embodiment, the density of the polyurethane foam is 80 kg / m 3 Above, for example, it can be 80kg / m 3 , 81kg / m 3 、82kg / m 3 、83kg / m 3 、84kg / m 3 、85kg / m 3 、86kg / m 3 、87kg / m 3 、88kg / m 3 , 90kg / m 3 , 92kg / m 3 , 94kg / m 3 , 95kg / m 3 , 96kg / m 3 、98kg / m 3 , 100kg / m 3 、102kg / m 3 、104kg / m 3 , 105kg / m 3 、106kg / m 3 、108kg / m 3 、110kg / m 3 、112kg / m 3 , 115kg / m3 etc., preferably 85 to 120 kg / m 3 More preferably, 95 to 110 kg / m 3 .

[0201] As an optional embodiment, when the viscosity of the absorbed liquid is 100 to 300 mPa·s, the liquid absorption speed of the polyurethane foam is 0.050 mL / s or more, for example, 0.050 mL / s, 0.055 mL / s, 0.060 mL / s, 0.065 mL / s, 0.070 mL / s, 0.075 mL / s, 0.080 mL / s, 0.085 mL / s, 0.090 mL / s, 0.095 mL / s, 0.100 mL / s, 0.105 mL / s, 0.110 mL / s, 0.115 mL / s, 0.120 mL / s, 0.125 mL / s, The speed of the invention can be 0.130 mL / s, 0.135 mL / s, 0.140 mL / s, 0.145 mL / s, 0.150 mL / s, 0.155 mL / s, 0.160 mL / s, 0.165 mL / s, 0.170 mL / s, 0.175 mL / s, 0.180 mL / s, 0.185 mL / s, 0.190 mL / s, 0.195 mL / s, 0.200 mL / s, 0.205 mL / s, 0.210 mL / s, 0.215 mL / s, 0.220 mL / s, etc., preferably 0.100 mL / s or more, more preferably 0.200 mL / s or more.

[0202] As an optional implementation, the absorption liquid with a viscosity of 100-300 mPa·s may be a 1% by mass CMC A solution, and the test conditions may be 20° C. and 50% RH.

[0203] As an optional embodiment, when the viscosity of the absorbed liquid is 300 to 500 mPa·s, the liquid absorption speed of the polyurethane foam is 0.015 mL / s or more, for example, 0.015 mL / s, 0.016 mL / s, 0.018 mL / s, 0.020 mL / s, 0.022 mL / s, 0.024 mL / s, 0.025 mL / s, 0.026 mL / s, 0.028 mL / s, 0.030 mL / s, 0.032 mL / s, 0.034 mL / s, 0.035 mL / s, 0.036 mL / s, 0.040 mL / s, 0.042 mL / s, 0.044 mL / s, 0.045 mL / s, 0.046 mL / s, 0.048 mL / s, 0.050 mL / s, etc., preferably 0.030 mL / s or more, more preferably 0.040 mL / s or more.

[0204] As an optional implementation, the absorption liquid with a viscosity of 300-500 mPa·s may be a 1.5% by mass CMC A solution, and the test conditions may be 20° C. and 50% RH.

[0205] In a fourth aspect, the present invention provides a method for preparing the finger-shaped channel polyurethane foam as described in the third aspect, Figure 1 As shown, the preparation method of the polyurethane foam comprises the following steps:

[0206] The stock solution A and the stock solution B are mixed and stirred, and then extruded at a constant flow rate to obtain an extruded liquid;

[0207] The extruded liquid is coated to form a flat foaming liquid, which is then dried to obtain a finger-shaped channel polyurethane foam.

[0208] As an optional embodiment, the rotation speed of the mixing and stirring is 2000-5000rpm, for example, it can be 2000rpm, 2100rpm, 2300rpm, 2500rpm, 2700rpm, 2900rpm, 3100rpm, 3300rpm, 3500rpm, 3700rpm, 3900rpm, 4100rpm, 4300rpm, 4500rpm, 4700rpm, 4900rpm, 5000rpm, etc., preferably 2500-4500rpm.

[0209] As an optional embodiment, the specific steps of coating include the following steps:

[0210] The extruded liquid is passed through a roller blade coater to obtain a flat foaming liquid, which is then covered with a silicon-treated release paper, and the pulling speeds of the foaming liquid and the release paper are kept synchronous.

[0211] As an optional embodiment, the drying is performed in a forced air oven.

[0212] As an optional embodiment, the drying temperature is 80-200°C, for example, it can be 80°C, 100°C, 120°C, 140°C, 160°C, 180°C, 200°C, etc.

[0213] In a fifth aspect, the present invention provides a use of the foam stock solution for absorbing thick exudate as described in the first aspect, or the polyurethane foam as described in the third aspect in preparing a medical wound dressing.

[0214] In conjunction with the examples, some embodiments of the present invention are described in detail below. In the absence of conflict, the following examples and features in the examples can be combined with each other. The raw materials used in the examples and comparative examples of the present invention, if no specific conditions are specified, are carried out under normal conditions or conditions recommended by the manufacturer. The reagents or instruments used, if the manufacturer is not specified, are all conventional products that can be purchased commercially.

[0215] Preparation Example 1

[0216] This preparation example provides an isocyanate prepolymer, which is prepared by the following steps:

[0217] (a) 6 parts of glycerol, 2 parts of trimethylolpropane, 60 parts of ethylene oxide, 20 parts of propylene oxide, and 0.5 parts of sodium hydroxide are mixed, and the mixture is vacuumed at 120° C. for 2 hours to obtain a glyceryl polyether polyol;

[0218] (b) adding 26 parts of toluene diisocyanate, 0.2 parts of dibutyltin dilaurate and 0.1 parts of 2,6-di-tert-butyl-p-cresol to 55 parts of glyceryl polyether polyol, reacting at 72° C. for 2 hours to obtain reaction solution A; mixing reaction solution A with 24 parts of toluene diisocyanate, heating to 78° C. for 1 hour to obtain a preliminary toluene diisocyanate prepolymer;

[0219] (c) adding 4 parts of 1,4-butanediol and 1 part of ethylene glycol to the preliminary toluene diisocyanate prepolymer, and reacting at 60° C. for 30 minutes to obtain the toluene diisocyanate prepolymer.

[0220] Preparation Example 2

[0221] This preparation example provides an isocyanate prepolymer, which is prepared by the following steps:

[0222] (a) 7 parts of trimethylolpropane, 1 part of diethylene glycol, 50 parts of ethylene oxide, 30 parts of propylene oxide, and 0.5 parts of sodium hydroxide are mixed, and the mixture is vacuumed at 120° C. for 2 hours to obtain a trimethylolpropane-based polyether polyol;

[0223] (b) adding 25 parts of diphenylmethane diisocyanate, 0.2 parts of bis(dimethylaminoethyl) ether and 0.1 parts of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate] to 56 parts of trimethylolpropane-based polyether polyol, and reacting at 72° C. for 2 hours to obtain reaction solution A; mixing reaction solution A with 25 parts of diphenylmethane diisocyanate, heating to 78° C. and reacting for 1 hour to obtain a preliminary diphenylmethane diisocyanate prepolymer;

[0224] (c) adding 3 parts of trimethylolpropane and 2 parts of triethanolamine to the preliminary diphenylmethane diisocyanate prepolymer, reacting at 60° C. for 30 minutes to obtain the diphenylmethane diisocyanate prepolymer.

[0225] Preparation Example 3

[0226] This preparation example provides an isocyanate prepolymer, which is prepared by the following steps:

[0227] (a) 7.5 parts of sucrose, 0.5 parts of sorbitol, 55 parts of ethylene oxide, 25 parts of propylene oxide, and 0.5 parts of sodium hydroxide were mixed, and the mixture was vacuumed at 120° C. for 2 hours to obtain a sucrose-based polyether polyol;

[0228] (b) adding 27 parts of dimethylbiphenyl diisocyanate, 0.2 parts of N-methylmorpholine and 0.1 parts of -hydroxy-4-methoxybenzophenone to 57 parts of sucrose-based polyether polyol, reacting at 72° C. for 2 hours to obtain reaction solution A; mixing reaction solution A with 23 parts of dimethylbiphenyl diisocyanate, heating to 78° C. for 1 hour to obtain a preliminary dimethylbiphenyl diisocyanate prepolymer;

[0229] (c) adding 4 parts of 1,6-hexanediol and 1 part of neopentyl glycol to the preliminary dimethyl biphenyl diisocyanate prepolymer, and reacting at 60° C. for 30 minutes to obtain the dimethyl biphenyl diisocyanate prepolymer.

[0230] Preparation Example 4

[0231] This preparation example provides an isocyanate prepolymer, which is prepared by the following steps:

[0232] (a) 7 parts of sorbitol, 1 part of diethylene glycol, 65 parts of ethylene oxide, 15 parts of propylene oxide, and 0.5 parts of sodium hydroxide are mixed, and the mixture is vacuumed at 120° C. The reaction time is 2 hours to obtain a sorbitol-based polyether polyol;

[0233] (b) adding 28 parts of cyclohexane dimethylene diisocyanate, 0.2 parts of tetramethylethylenediamine and 0.1 parts of 2-(2H-benzotriazole-2-yl)-4,6-di-tert-amylphenol to 58 parts of sorbitol-based polyether polyol, reacting at 72° C. for 2 hours to obtain a reaction solution A; mixing the reaction solution A with 22 parts of cyclohexane dimethylene diisocyanate, heating to 78° C. for 1 hour to obtain a cyclohexane dimethylene diisocyanate prepolymer;

[0234] (c) Add 2.5 parts of triethylenetetramine and 2.5 parts of tetraethylenepentamine to the preliminary cyclohexane dimethylene diisocyanate prepolymer, and react at 65° C. for 30 min to obtain the cyclohexane dimethylene diisocyanate prepolymer.

[0235] Preparation Example 5

[0236] This preparation example provides an isocyanate prepolymer, which is prepared by the following steps:

[0237] (a) 6 parts of glycerol, 2 parts of ethylene glycol, 80 parts of propylene oxide and 0.5 parts of sodium hydroxide were mixed, the temperature was controlled at 120° C. and vacuum was applied, and the reaction time was 2 hours to obtain polyoxypropylene polyol;

[0238] (b) adding 29 parts of norbornane diisocyanate, 0.2 parts of dibutyltin dilaurate and 0.1 parts of 2,6-di-tert-butyl-p-cresol to 59 parts of polyoxypropylene polyol, reacting at 72° C. for 2 hours to obtain a reaction solution A; mixing the reaction solution A with 21 parts of norbornane diisocyanate, heating to 78° C. for 1 hour to obtain a preliminary norbornane diisocyanate prepolymer;

[0239] (c) adding 4 parts of 1,4-butanediol and 1 part of 1,6-hexanediol to the preliminary norbornane diisocyanate prepolymer, and reacting at 65° C. for 30 minutes to obtain the norbornane diisocyanate prepolymer.

[0240] Preparation Example 6

[0241] This preparation example provides an isocyanate prepolymer, which is prepared by the following steps:

[0242] (a) 8 parts of glycerol, 80 parts of ethylene oxide and 0.5 parts of sodium hydroxide are mixed, and the mixture is vacuumed at 120° C. for 2 hours to obtain a glyceryl polyether polyol;

[0243] (b) adding 26 parts of toluene diisocyanate and 0.3 parts of dibutyltin dilaurate to 55 parts of glyceryl polyether polyol, reacting at 72° C. for 2 hours to obtain reaction solution A; mixing reaction solution A with 24 parts of toluene diisocyanate, heating to 78° C. for 1 hour to obtain a preliminary toluene diisocyanate prepolymer;

[0244] (c) Add 5 parts of ethylene glycol to the preliminary toluene diisocyanate prepolymer, and react at 65° C. for 30 minutes to obtain the toluene diisocyanate prepolymer.

[0245] Preparation Example 7

[0246] This preparation example provides an isocyanate prepolymer, which is prepared by the following steps:

[0247] (a) 8 parts of trimethylolpropane, 80 parts of propylene oxide and 0.5 parts of sodium hydroxide are mixed, and the mixture is vacuumed at 120° C. for 2 hours to obtain a trimethylolpropane-based polyether polyol;

[0248] (b) adding 25 parts of diphenylmethane diisocyanate and 0.3 parts of bis(dimethylaminoethyl)ether to 56 parts of trimethylolpropane polyether polyol, and reacting at 72° C. for 2 hours to obtain reaction solution A; mixing reaction solution A and 25 parts of diphenylmethane diisocyanate, heating to 78° C. and reacting for 1 hour to obtain a preliminary diphenylmethane diisocyanate prepolymer;

[0249] (c) adding 5 parts of triethanolamine to the preliminary diphenylmethane diisocyanate prepolymer, and reacting at 70° C. for 30 min to obtain the diphenylmethane diisocyanate prepolymer.

[0250] Preparation Example 8

[0251] This preparation example provides an isocyanate prepolymer, which is prepared by the following steps:

[0252] (a) 8 parts of sucrose, 80 parts of propylene oxide and 0.5 parts of sodium hydroxide were mixed, and the mixture was vacuumed at 120° C. for 2 hours to obtain a sucrose-based polyether polyol;

[0253] (b) adding 27 parts of dimethylbiphenyl diisocyanate and 0.3 parts of N-methylmorpholine to 57 parts of sucrose-based polyether polyol, reacting at 72° C. for 2 hours to obtain a reaction solution A; mixing the reaction solution A with 23 parts of dimethylbiphenyl diisocyanate, heating to 78° C. for 1 hour to obtain a preliminary dimethylbiphenyl diisocyanate prepolymer;

[0254] (c) adding 5 parts of 1,6-hexanediol to the preliminary dimethylbiphenyl diisocyanate prepolymer, and reacting at 70° C. for 30 minutes to obtain the dimethylbiphenyl diisocyanate prepolymer.

[0255] Example 1

[0256] This embodiment provides a polyurethane foam for absorbing thick exudate, wherein the polyurethane foam is formed by mixing the stock solution A and the stock solution B in the foam stock solution for absorbing thick exudate, and then applying and foaming.

[0257] Wherein, the thick exudate absorbing foam stock solution comprises the following components by weight:

[0258]

[0259] Wherein, the polyurethane foam for absorbing thick exudate is prepared by the following steps:

[0260] (1) Weighing a hydrophilic chain extender, a surfactant, a lubricant, a catalyst and water according to the above formula, mixing and stirring at 25° C. and 300 rpm to obtain a stock solution A; weighing a toluene diisocyanate prepolymer provided in Preparation Example 1 according to the above formula, stirring at 35° C. and 200 rpm to obtain a stock solution B;

[0261] (2) The stock solution A and the stock solution B are stirred and mixed and extruded at 3000 rpm. The extruded liquid is passed through a roller blade coater to obtain a flat foaming mixed liquid, which is then covered with a silicon-treated release paper. The pulling speeds of the foaming liquid and the release paper are kept synchronous, and the mixture is dried in a blast oven (120° C.) to obtain a polyurethane foam with a thickness of 5 mm±0.5 mm.

[0262] like Figure 2 As shown, in Example 1, finger-shaped pores are formed during the phase transformation of the polyurethane foam, and the pores have abundant channels, that is, the foam pores are finger-shaped in the vertical cross section, and the pore size is small on the side close to the human body, which can provide a fast mass transfer channel for medium migration.

[0263] Example 2

[0264] This embodiment provides a polyurethane foam for absorbing thick exudate, wherein the polyurethane foam is formed by mixing the stock solution A and the stock solution B in the foam stock solution for absorbing thick exudate, and then applying and foaming.

[0265] Wherein, the thick exudate absorbing foam stock solution comprises the following components by weight:

[0266]

[0267] Wherein, the polyurethane foam for absorbing thick exudate is prepared by the following steps:

[0268] (1) Weighing a hydrophilic chain extender, a surfactant, a lubricant, a catalyst and water according to the above formula, mixing and stirring at 20° C. and 400 rpm to obtain a stock solution A; weighing a diphenylmethane diisocyanate prepolymer provided in Preparation Example 2 according to the above formula, stirring at 30° C. and 300 rpm to obtain a stock solution B;

[0269] (2) The stock solution A and the stock solution B are stirred and mixed and extruded at 3500 rpm. The extruded liquid is passed through a roller blade coater to obtain a flat foaming mixed liquid, which is then covered with a silicon-treated release paper. The pulling speeds of the foaming liquid and the release paper are kept synchronous, and the mixture is dried in a blast oven (100° C.) to obtain a polyurethane foam with a thickness of 5 mm±0.5 mm.

[0270] like Figure 3 As shown, in Example 2, finger-shaped pores are formed during the phase transformation of the polyurethane foam, and the pores have abundant pores, that is, the foam pores are finger-shaped in the vertical cross-section, and the pore size is small on the side close to the human body, which can provide a fast mass transfer channel for medium migration.

[0271] Example 3

[0272] This embodiment provides a polyurethane foam for absorbing thick exudate, wherein the polyurethane foam is formed by mixing the stock solution A and the stock solution B in the foam stock solution for absorbing thick exudate, and then applying and foaming.

[0273] Wherein, the thick exudate absorbing foam stock solution comprises the following components by weight:

[0274]

[0275] Wherein, the polyurethane foam for absorbing thick exudate is prepared by the following steps:

[0276] (1) Weighing a hydrophilic chain extender, a surfactant, a lubricant, a catalyst and water according to the above formula, mixing and stirring at 30° C. and 250 rpm to obtain a stock solution A; weighing a dimethylbiphenyl diisocyanate prepolymer provided in Preparation Example 3 according to the above formula, stirring at 40° C. and 250 rpm to obtain a stock solution B;

[0277] (2) The stock solution A and the stock solution B are stirred and mixed and extruded at 4000 rpm. The extruded liquid is passed through a roller blade coater to obtain a flat foaming mixed liquid, which is then covered with a silicon-treated release paper. The pulling speeds of the foaming liquid and the release paper are kept synchronized. The mixture is dried in a blast oven (140° C.) to obtain a polyurethane foam with a thickness of 5 mm±0.5 mm.

[0278] like Figure 4 As shown, in Example 3, finger-shaped pores are formed during the phase transformation of the polyurethane foam, and the pores have abundant channels, that is, the foam pores are finger-shaped in the vertical cross-section, and the pore size is small on the side close to the human body, which can provide a fast mass transfer channel for medium migration.

[0279] Example 4

[0280] This embodiment provides a polyurethane foam for absorbing thick exudate, wherein the polyurethane foam is formed by mixing the stock solution A and the stock solution B in the foam stock solution for absorbing thick exudate, and then applying and foaming.

[0281] Wherein, the thick exudate absorbing foam stock solution comprises the following components by weight:

[0282]

[0283] Wherein, the polyurethane foam for absorbing thick exudate is prepared by the following steps:

[0284] (1) Weighing a hydrophilic chain extender, a surfactant, a lubricant, a catalyst and water according to the above formula, mixing and stirring at 25° C. and 300 rpm to obtain a stock solution A; weighing a cyclohexane dimethylene diisocyanate prepolymer provided in Preparation Example 4 according to the above formula, stirring at 35° C. and 200 rpm to obtain a stock solution B;

[0285] (2) The stock solution A and the stock solution B are stirred and mixed and extruded at 4500 rpm. The extruded liquid is passed through a roller blade coater to obtain a flat foaming mixed liquid, which is then covered with a silicon-treated release paper. The pulling speeds of the foaming liquid and the release paper are kept synchronized. The mixture is dried in a blast oven (120° C.) to obtain a polyurethane foam with a thickness of 5 mm±0.5 mm.

[0286] like Figure 5 As shown, in Example 4, finger-shaped pores are formed during the phase transformation of the polyurethane foam, and the pores have abundant channels, that is, the foam pores are finger-shaped in the vertical cross-section, and the pore size is small on the side close to the human body, which can provide a fast mass transfer channel for medium migration.

[0287] Example 5

[0288] This embodiment provides a polyurethane foam for absorbing thick exudate, wherein the polyurethane foam is formed by mixing the stock solution A and the stock solution B in the foam stock solution for absorbing thick exudate, and then applying and foaming.

[0289] Wherein, the thick exudate absorbing foam stock solution comprises the following components by weight:

[0290]

[0291]

[0292] Wherein, the polyurethane foam for absorbing thick exudate is prepared by the following steps:

[0293] (1) Weighing a hydrophilic chain extender, a surfactant, a lubricant, a catalyst and water according to the above formula, mixing and stirring at 15° C. and 300 rpm to obtain a stock solution A; weighing a norbornane diisocyanate prepolymer provided in Preparation Example 5 according to the above formula, stirring at 35° C. and 200 rpm to obtain a stock solution B;

[0294] (2) The stock solution A and the stock solution B are stirred and mixed and extruded at 3000 rpm. The extruded liquid is passed through a roller blade coater to obtain a flat foaming mixed liquid, which is then covered with a silicon-treated release paper. The pulling speeds of the foaming liquid and the release paper are kept synchronous, and the mixture is dried in a blast oven (120° C.) to obtain a polyurethane foam with a thickness of 5 mm±0.5 mm.

[0295] Embodiments 6 to 9

[0296] Embodiments 6 to 9 provide polyurethane foams for absorbing thick exudate in different proportions, wherein the polyurethane foams are formed by mixing the stock solution A and the stock solution B in the stock solution for absorbing thick exudate, and then applying and foaming;

[0297] Wherein, the thick exudate absorbing foam stock solution comprises the following components by weight:

[0298]

[0299] Wherein, the preparation method of the polyurethane foam for absorbing thick exudate is consistent with that in Example 1.

[0300] Example 10

[0301] This embodiment provides a polyurethane foam for absorbing thick exudate, wherein the polyurethane foam is formed by mixing the stock solution A and the stock solution B in the foam stock solution for absorbing thick exudate, and then applying and foaming.

[0302] Wherein, the thick exudate absorbing foam stock solution comprises the following components by weight:

[0303]

[0304]

[0305] Wherein, the polyurethane foam for absorbing thick exudate is prepared by the following steps:

[0306] (1) Weighing a hydrophilic chain extender, a surfactant, a lubricant, a catalyst and water according to the above formula, mixing and stirring at 25° C. and 300 rpm to obtain a stock solution A; weighing a toluene diisocyanate prepolymer provided in Preparation Example 1 according to the above formula, stirring at 35° C. and 200 rpm to obtain a stock solution B;

[0307] (2) The stock solution A and the stock solution B are stirred and mixed and extruded at 2500 rpm. The extruded liquid is passed through a roller blade coater to obtain a flat foaming mixed liquid, which is then covered with a silicon-treated release paper. The pulling speeds of the foaming liquid and the release paper are kept synchronized. The mixture is dried in a blast oven (120° C.) to obtain a polyurethane foam with a thickness of 5 mm±0.5 mm.

[0308] Embodiment 11

[0309] This embodiment provides a polyurethane foam for absorbing thick exudate, wherein the polyurethane foam is formed by mixing the stock solution A and the stock solution B in the foam stock solution for absorbing thick exudate, and then applying and foaming.

[0310] Wherein, the thick exudate absorbing foam stock solution comprises the following components by weight:

[0311]

[0312] Wherein, the polyurethane foam for absorbing thick exudate is prepared by the following steps:

[0313] (1) Weighing a hydrophilic chain extender, a surfactant, a lubricant, a catalyst and water according to the above formula, mixing and stirring at 20° C. and 400 rpm to obtain a stock solution A; weighing a diphenylmethane diisocyanate prepolymer provided in Preparation Example 2 according to the above formula, stirring at 30° C. and 300 rpm to obtain a stock solution B;

[0314] (2) The stock solution A and the stock solution B are stirred and mixed and extruded at 2700 rpm. The extruded liquid is passed through a roller blade coater to obtain a flat foaming mixed liquid, which is then covered with a silicon-treated release paper. The pulling speeds of the foaming liquid and the release paper are kept synchronous, and the mixture is dried in a blast oven (100° C.) to obtain a polyurethane foam with a thickness of 5 mm±0.5 mm.

[0315] Example 12

[0316] This embodiment provides a polyurethane foam for absorbing thick exudate, wherein the polyurethane foam is formed by mixing the stock solution A and the stock solution B in the foam stock solution for absorbing thick exudate, and then applying and foaming.

[0317] Wherein, the thick exudate absorbing foam stock solution comprises the following components by weight:

[0318]

[0319]

[0320] Wherein, the polyurethane foam for absorbing thick exudate is prepared by the following steps:

[0321] (1) Weighing a hydrophilic chain extender, a surfactant, a lubricant, a catalyst and water according to the above formula, mixing and stirring at 30° C. and 250 rpm to obtain a stock solution A; weighing a dimethylbiphenyl diisocyanate prepolymer provided in Preparation Example 3 according to the above formula, stirring at 40° C. and 250 rpm to obtain a stock solution B;

[0322] (2) The stock solution A and the stock solution B are stirred and mixed and extruded at 4000 rpm. The extruded liquid is passed through a roller blade coater to obtain a flat foaming mixed liquid, which is then covered with a silicon-treated release paper. The pulling speeds of the foaming liquid and the release paper are kept synchronized. The mixture is dried in a blast oven (140° C.) to obtain a polyurethane foam with a thickness of 5 mm±0.5 mm.

[0323] Example 13

[0324] This embodiment provides a polyurethane foam for absorbing thick exudate, wherein the polyurethane foam is formed by mixing the stock solution A and the stock solution B in the foam stock solution for absorbing thick exudate, and then applying and foaming.

[0325] Wherein, the thick exudate absorbing foam stock solution comprises the following components by weight:

[0326]

[0327] Wherein, the polyurethane foam for absorbing thick exudate is prepared by the following steps:

[0328] (1) Weighing a hydrophilic chain extender, a surfactant, a lubricant, a catalyst and water according to the above formula, mixing and stirring at 25° C. and 300 rpm to obtain a stock solution A; weighing a cyclohexane dimethylene diisocyanate prepolymer provided in Preparation Example 4 according to the above formula, stirring at 35° C. and 200 rpm to obtain a stock solution B;

[0329] (2) The stock solution A and the stock solution B are stirred and mixed and extruded at 2900 rpm. The extruded liquid is passed through a roller blade coater to obtain a flat foaming mixed liquid, which is then covered with a silicon-treated release paper. The pulling speeds of the foaming liquid and the release paper are kept synchronized. The mixture is dried in a blast oven (120° C.) to obtain a polyurethane foam with a thickness of 5 mm±0.5 mm.

[0330] Embodiment 14

[0331] This embodiment provides a polyurethane foam for absorbing thick exudate, wherein the polyurethane foam is formed by mixing the stock solution A and the stock solution B in the foam stock solution for absorbing thick exudate, and then applying and foaming.

[0332] Wherein, the thick exudate absorbing foam stock solution comprises the following components by weight:

[0333]

[0334]

[0335] Wherein, the polyurethane foam for absorbing thick exudate is prepared by the following steps:

[0336] (1) Weighing a hydrophilic chain extender, a surfactant, a lubricant, a catalyst and water according to the above formula, mixing and stirring at 25° C. and 300 rpm to obtain a stock solution A; weighing a norbornane diisocyanate prepolymer provided in Preparation Example 5 according to the above formula, stirring at 35° C. and 200 rpm to obtain a stock solution B;

[0337] (2) The stock solution A and the stock solution B are stirred and mixed and extruded at 4100 rpm. The extruded liquid is passed through a roller blade coater to obtain a flat foaming mixed liquid, which is then covered with a silicon-treated release paper. The pulling speeds of the foaming liquid and the release paper are kept synchronized. The mixture is dried in a blast oven (120° C.) to obtain a polyurethane foam with a thickness of 5 mm±0.5 mm.

[0338] Embodiment 15

[0339] This embodiment provides a polyurethane foam for absorbing thick exudate. The difference from Embodiment 1 is that glycerol is replaced by lauric acid of equal mass, and the other steps are consistent with Embodiment 1.

[0340] Example 16

[0341] This embodiment provides a polyurethane foam for absorbing thick exudate. The difference from Embodiment 1 is that glycerol is replaced with an equal mass of alginic acid, and the other steps are consistent with Embodiment 1.

[0342] Embodiment 17

[0343] This embodiment provides a polyurethane foam for absorbing thick exudate. The difference from Embodiment 1 is that propylene glycol is replaced with an equal mass of diaminodicyclohexylmethane, and the other steps are consistent with Embodiment 1.

[0344] Embodiment 18

[0345] This embodiment provides a polyurethane foam for absorbing thick exudate. The difference from Embodiment 1 is that propylene glycol is replaced with an equal mass of polyethylene glycol (average molecular weight of 2000 g / mol), and the other steps are consistent with Embodiment 1.

[0346] Embodiment 19

[0347] This embodiment provides a polyurethane foam for absorbing thick exudate. The difference from Example 1 is that propylene glycol is replaced with an equal mass of propylene oxide-ethylene oxide copolyether triol (average molecular weight of 2000 g / mol), and the other steps are consistent with Example 1.

[0348] Embodiment 20

[0349] This embodiment provides a polyurethane foam for absorbing thick exudate. The difference from Embodiment 1 is that glycerol is replaced by an equal mass of polycaprolactone (average molecular weight of 1000 g / mol), and the other steps are consistent with Embodiment 1.

[0350] Embodiment 21

[0351] This embodiment provides a polyurethane foam for absorbing thick exudate. The difference from Embodiment 1 is that glycerol is replaced with fructose of equal mass, and the other steps are consistent with Embodiment 1.

[0352] Embodiment 22

[0353] This embodiment provides a polyurethane foam for absorbing thick exudate. The difference from Embodiment 1 is that propylene glycol is replaced with an equal mass of 4,4'-methylenebis(3-chloro-2,6-diethylaniline), and the other steps are consistent with Embodiment 1.

[0354] Embodiment 23

[0355] This embodiment provides a polyurethane foam for absorbing thick exudate. The difference from Embodiment 1 is that the surfactant is only 6 parts of polyoxyethylene ether TX-10, and the other steps are consistent with Embodiment 1.

[0356] Embodiment 24

[0357] This embodiment provides a polyurethane foam for absorbing thick exudate. The difference from Embodiment 1 is that the surfactant is only 6 parts of polyethylene glycol 2000, and the other steps are consistent with Embodiment 1.

[0358] Embodiment 25

[0359] This embodiment provides a polyurethane foam for absorbing thick exudate. The difference from Embodiment 1 is that the surfactant is only 6 parts of isomeric alcohol ether PE6200, and the other steps are consistent with Embodiment 1.

[0360] Embodiment 26

[0361] This embodiment provides a polyurethane foam for absorbing thick exudate. The difference from Embodiment 1 is that the lubricant is only 4 parts of methyl cellulose, and the other steps are consistent with Embodiment 1.

[0362] Embodiment 27

[0363] This embodiment provides a polyurethane foam for absorbing thick exudate. The difference from Embodiment 1 is that the lubricant is only 4 parts of sodium carboxymethyl cellulose, and the other steps are consistent with Embodiment 1.

[0364] Embodiment 28

[0365] This embodiment provides a polyurethane foam for absorbing thick exudate. The difference from Embodiment 1 is that the lubricant is only 4 parts of xanthan gum, and the other steps are consistent with Embodiment 1.

[0366] Embodiment 29

[0367] This embodiment provides a polyurethane foam for absorbing thick exudate. The difference from Embodiment 1 is that the lubricant is only 4 parts of starch, and the other steps are consistent with Embodiment 1.

[0368] Embodiment 30

[0369] This embodiment provides a polyurethane foam for absorbing thick exudate. The difference from Example 1 is that the toluene diisocyanate prepolymer provided in Preparation Example 1 is replaced with an equal mass of toluene diisocyanate prepolymer provided in Preparation Example 6, and the other steps are consistent with Example 1.

[0370] Embodiment 31

[0371] This embodiment provides a polyurethane foam for absorbing thick exudate. The difference from Example 1 is that the toluene diisocyanate prepolymer provided in Preparation Example 1 is replaced with an equal mass of diphenylmethane diisocyanate prepolymer provided in Preparation Example 7, and the other steps are consistent with Example 1.

[0372] Embodiment 32

[0373] This embodiment provides a polyurethane foam for absorbing thick exudate. The difference from Example 1 is that the toluene diisocyanate prepolymer provided in Preparation Example 1 is replaced with an equal mass of dimethyl diphenyl diisocyanate prepolymer provided in Preparation Example 8, and the other steps are consistent with Example 1.

[0374] Comparative Examples 1 to 5

[0375] This comparative example provides polyurethane foams with different compositions and the same proportions. The polyurethane foams are formed by mixing the stock solution A and the stock solution B in the foam stock solution and then applying and foaming.

[0376] Wherein, the foam stock solution comprises the following components by weight:

[0377]

[0378]

[0379] Wherein, the polyurethane foam used to absorb thick exudate is consistent with that in Example 1:

[0380] Comparative Example 6

[0381] This comparative example provides a polyurethane foam, which is different from Example 1 only in that the diisocyanate prepolymer in the stock solution B is replaced with toluene diisocyanate of the same mass, and the other steps are consistent with Example 1.

[0382] Comparative Example 7

[0383] This comparative example provides a polyurethane foam, which is different from Example 2 only in that the diisocyanate prepolymer in the stock solution B is replaced with an equal mass of 1,6-hexamethylene diisocyanate, and the other steps are consistent with Example 2.

[0384] Comparative Example 8

[0385] This comparative example provides a polyurethane foam, which is different from Example 3 only in that the diisocyanate prepolymer in the stock solution B is replaced with an equal mass of xylene diisocyanate, and the other steps are consistent with Example 3.

[0386] Comparative Example 9

[0387] This comparative example provides a polyurethane foam, which is different from Example 4 only in that the diisocyanate prepolymer in the stock solution B is replaced with an equal mass of dicyclohexylmethane diisocyanate, and the other steps are consistent with Example 4.

[0388] Comparative Example 10

[0389] This comparative example provides a polyurethane foam, which is different from Example 5 only in that the diisocyanate prepolymer in the stock solution B is replaced with an equal mass of 1,4-cyclohexane diisocyanate, and the other steps are consistent with Example 5.

[0390] Test Example 1

[0391] Test samples: polyurethane foams for absorbing thick exudate provided in Examples 1 to 32, and polyurethane foams provided in Comparative Examples 1 to 10.

[0392] Test method:

[0393] (1) Average pore size: Cut the polyurethane foam into suitable sizes and fix it on the sample stage. After gold spraying, select a suitable area under the electronic imaging mode of a scanning electron microscope (model: HITACHI SU8010) and use a fixed magnification to photograph the surface morphology of the material. Identify the pore edge based on the grayscale difference and use the image analysis software provided by the instrument to test the pore size. Test multiple pore sizes and calculate the average value.

[0394] (2) Surface porosity: Cut the polyurethane foam into regular shapes (e.g., rectangular shapes), place it in the sample cell of a helium densimeter (model: 3H-2000TD), evacuate the sample cell to remove residual gas, fill the sample cell with helium, record the initial and equilibrium pressures of the sample cell, calculate the sample volume according to the gas state equation, calculate the apparent density using the sample mass and volume, and calculate the surface porosity of the material using the apparent density and true density;

[0395] (3) Density: According to ISO 845, the apparent density of foam plastics and rubber is determined by cutting the polyurethane foam into samples of regular shapes. The length, width and height of the samples are measured using a ruler. The mass of the material (m) is measured using an analytical balance. The density formula is used to calculate the density. Find the density of the material;

[0396] (4) Thick liquid absorption rate: CMC A solutions of different concentrations were used to simulate different degrees of thick wound exudate. At room temperature (20±3°C, 50±10% RH), the polyurethane foam was placed on a horizontal surface, 1 mL of thick liquid was taken with a dropper, and quickly dripped onto the surface of the polyurethane foam. A stopwatch was used to record the time interval from the thick exudate dripping onto the foam surface to complete absorption.

[0397] The thick liquid is selected as follows: 1% CMC A solution, 1.5% CMC A solution; A solution preparation method: It is composed of a solution of sodium chloride and calcium chloride, and the solution contains 142mmol sodium ions and 2.5mmol calcium ions. The ion content of this solution is equivalent to human serum or wound exudate. Dissolve 8.298g sodium chloride and 0.368g calcium chloride dihydrate in deionized water in a volumetric flask and dilute to 1L. CMC (sodium carboxymethyl cellulose) is selected as a white or slightly yellow fibrous powder with a viscosity of 300-800mPa·s.

[0398] The specific test results are shown in Table 1 below: The specific test results are shown in Table 1 below:

[0399] Table 1

[0400]

[0401]

[0402]

[0403] As shown in Table 1, the foam stock solution for absorbing thick exudate of the present invention includes a stock solution A formed by a hydrophilic chain extender, a surfactant, water, a lubricant and a catalyst in a specific ratio and composition, and a stock solution B made of an isocyanate prepolymer. After the two are mixed and stirred, they are coated and foamed to finally form the desired polyurethane foam. In the process of phase transformation of the polyurethane foam, special pores with a finger-like pore structure are formed, which have abundant pores and can provide a fast mass transfer channel for medium migration. The polyurethane foam of the present invention is a special foam with a finger-like pore structure, which can provide a fast mass transfer channel for medium migration. This structure is conducive to the rapid passage of substances, thereby improving the material migration efficiency and mass transfer performance of the polyurethane foam.

[0404] Test Example 2

[0405] Test samples: polyurethane foams for absorbing thick exudate provided in Examples 1 to 32, and polyurethane foams provided in Comparative Examples 1 to 10.

[0406] Test principle: The definition of contact angle refers to the angle θ between the tangent line of the gas-liquid interface and the solid-liquid boundary line at the intersection of gas, liquid and solid, which is a measure of wettability. Regulations: If θ < 90°, the solid is lyophilic, that is, the liquid can wet the solid, and the smaller the angle, the better the wettability; if θ > 90°, the solid is lyophobic, that is, the liquid does not wet the solid, it is easy to move on the surface and difficult to enter the pores.

[0407] Test method: Place the prepared sample (2cm x 2cm) on a glass slide, and then place the glass slide on the horizontal workbench of the contact angle instrument (model: KRUSSDSA30). The workbench can be moved up, down, left, and right by the knob so that the image appears in the center of the light source. The sample should be placed in a stable environment to avoid factors such as temperature and humidity from affecting the test results, and the sample should be kept horizontal. Drop 4μL of the test solution on the flat foam to be tested, use the contact angle instrument to record the shape change of the droplet on the foam to be tested, and use computer software to fit the initial contact angle when the liquid contacts the foam.

[0408] The specific test results are shown in Table 2 below:

[0409] Table 2

[0410]

[0411]

[0412]

[0413]

[0414] As shown in Table 2, the polyurethane foam for absorbing thick exudate provided by the present invention has θ < 90°, which means that the solid is lyophilic, that is, the liquid can wet the solid. The smaller the angle, the better the wettability, the excellent hydrophilicity, and the ability to fully absorb the exudate of the pressure sore wound.

[0415] As shown in Table 1 and Table 2 above, Examples 1 to 5 are preferred technical solutions of the present invention, which can maintain the pore structure (such as pore size), liquid absorption speed and hydrophilicity of the prepared polyurethane foam in an optimal equilibrium state. Preferably, the average pore size of the polyurethane foam is 350 to 450 μm, and when the absorbed liquid is tested by 1% CMC A solution, the liquid absorption speed of the polyurethane foam is above 0.20 mL / s, and when the absorbed liquid is tested by 1.5% CMC A solution, the liquid absorption speed of the polyurethane foam is above 0.040 mL / s; and the hydrophilicity is maintained in an optimal equilibrium state, the initial contact angle (1% CMC A solution test) is below 90°, and the initial contact angle (1.5% CMC A solution test) is below 100°.

[0416] From the comparison between Examples 1 to 5 and Examples 6 to 9, it can be seen that the stock solution A preferably comprises, by weight: 10 to 12 parts of a hydrophilic chain extender, 4 to 6 parts of a surfactant, 3 to 5 parts of a lubricant, 0.5 to 1.5 parts of a catalyst and 70 to 80 parts of water; wherein, the stock solution B preferably comprises, by weight: 110 to 130 parts of an isocyanate prepolymer; Examples 1 to 5 provide polyurethane foams as special foams with a finger-like pore structure having more abundant pores, and by optimizing the ratio of each component, the purpose of improving the polyurethane foam and mass transfer performance, and more significantly improving the exudate absorption capacity of the foam dressing is achieved.

[0417] From the comparison between Examples 1 to 5 and Examples 10 to 14, it can be seen that Examples 1 to 5 are the preferred technical solutions of the present invention, which can maintain the pore structure (such as pore size), liquid absorption speed and hydrophilicity of the prepared polyurethane foam in the best balance state. Although Examples 10 to 14 can also form special foams with finger-like pore structures, the liquid absorption capacity and hydrophilicity of the foam dressing are relatively poor.

[0418] From the comparison between Examples 1 to 5 and Examples 15 to 22, it can be seen that the hydrophilic chain extender provided in Examples 1 to 5 can maintain the pore structure (such as pore size), liquid absorption rate and hydrophilicity of the prepared polyurethane foam in the best balance state. Otherwise, if some non-preferred surfactants are selected, the pore size of the polyurethane foam may be too large, but the liquid absorption rate may decrease, and the hydrophilicity may be poor; or some non-preferred surfactants may increase the hydrophilicity of the polyurethane foam, but the pore size of the foam may be too small, which may also cause the liquid absorption rate to decrease.

[0419] From the comparison between Examples 1 to 5 and Examples 23 to 25, it can be seen that the selection of the first surfactant, the second surfactant and the third surfactant compound composition can maintain the pore structure (such as pore size), liquid absorption rate and hydrophilicity of the prepared polyurethane foam in the best balance state. Otherwise, if some non-preferred surfactants are selected, the pore size of the polyurethane foam may be too large, but the liquid absorption rate will decrease, and the hydrophilicity will be poor; or some non-preferred surfactants may increase the hydrophilicity of the polyurethane foam, but the pore size of the foam is too small, which will also cause the liquid absorption rate to decrease.

[0420] From the comparison between Examples 1 to 5 and Examples 26 to 29, it can be seen that the selection of the first lubricant, the second lubricant and the third lubricant compound composition can maintain the pore structure (such as pore size), liquid absorption speed and hydrophilicity of the prepared polyurethane foam in the best balance state. Otherwise, if some non-preferred lubricants are selected, the pore size of the polyurethane foam may be too large, but the liquid absorption speed may decrease, and the hydrophilicity may be poor; or some non-preferred lubricants may increase the hydrophilicity of the polyurethane foam, but the pore size of the foam is too small, which will also cause the liquid absorption speed to decrease.

[0421] From the comparison between Examples 1 to 5 and Examples 30 to 32, it can be seen that the exudate absorption capacity and hydrophilicity of the non-preferred isocyanate foam dressings used in Examples 30 to 32 are relatively poor.

[0422] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A foam stock solution for absorbing thick exudate, characterized in that: The foam stock solution for absorbing thick exudate comprises stock solution A and stock solution B in parts by weight; The stock solution A comprises, by weight: 1 to 20 parts of a hydrophilic chain extender, 1 to 10 parts of a surfactant, 1 to 10 parts of a lubricant, 0.1 to 2 parts of a catalyst and 50 to 99 parts of water; Wherein, the stock solution B comprises, by weight: 50 to 200 parts of isocyanate prepolymer.

2. The foam stock solution for absorbing thick exudate according to claim 1, characterized in that: The foam stock solution for absorbing thick exudate comprises stock solution A and stock solution B in parts by weight; The stock solution A comprises, by weight: 5 to 15 parts of a hydrophilic chain extender, 3 to 8 parts of a surfactant, 2 to 6 parts of a lubricant, 0.1 to 2 parts of a catalyst and 60 to 90 parts of water; Wherein, the stock solution B comprises, by weight: 100 to 150 parts of isocyanate prepolymer.

3. The foam stock solution for absorbing thick exudate according to claim 1 or 2, characterized in that: The foam stock solution for absorbing thick exudate comprises stock solution A and stock solution B in parts by weight; The stock solution A comprises, by weight: 10 to 12 parts of a hydrophilic chain extender, 4 to 6 parts of a surfactant, 3 to 5 parts of a lubricant, 0.5 to 1.5 parts of a catalyst and 70 to 80 parts of water; Wherein, the stock solution B comprises, by weight: 110 to 130 parts of isocyanate prepolymer.

4. The foam stock solution for absorbing thick exudate according to claim 1, characterized in that: The hydrophilic chain extender includes polyoxypropylene triol, oxypropylene-oxyethylene copolyether triol, polycaprolactone, fructose, lactose, maltose, maltitol, trehalose, sucrose, tetrahydroxy polyether polyol, pentaerythritol polyether polyol, diamino polyether tetraol, polyether pentaol, polyether hexaol, polystyrene polyol, castor oil and castor oil derivative polyol, soybean oil polyol, palm oil polyol, rosin ester polyol, 4,4'-methylenebis(3-chloro-2,6-diethylaniline), 4,4'-methylenebis(2,6-diethyl)aniline, 4,4'-methylenebis(2-methyl-6-diethylaniline), 4,4'-methylenebis(2-diethylaniline), 4,4'-methylenebis(2,6-diisopropyl)aniline, 4,4'-methylenebis(2-methyl-6-diethylaniline), 4,4'-methylenebis(2-diethylaniline), 4,4'-methylenebis(2,6-diisopropyl)aniline, 4,4'-methylenebis(2-methyl-6-diethylaniline). Any one or a combination of at least two of bis(2-isopropyl-6-methyl)aniline, 2,4-diamino-3,5-dimethylthiochlorobenzene, propylene glycol bis(4-benzoate), 3,5-diamino-4-chlorobenzoic acid isobutyl ester, coconut diethanolamide, dimethyl terephthalate, isophthalic acid, phthalic anhydride, 1,4-cyclohexanedicarboxylic acid, dimethyl 1,4-cyclohexanedicarboxylate, dimer acid, maleic anhydride, trimethylolpropane, pentaerythritol, xylitol, sorbitol, mannitol, triethylamine bis-2-(hydroxypropyl)aniline, toluenediamine, aniline, isophoronediamine, diaminodicyclohexylmethane, glycolic acid, gluconic acid, DL-mandelic acid, citric acid, pyrimidine acid, alginic acid, salicylic acid, lauric acid, glycerol, trimethylhexanediamine or sorbic acid.

5. The foam stock solution for absorbing thick exudate according to claim 4, characterized in that: The hydrophilic chain extender includes any one or a combination of at least two of trimethylolpropane, pentaerythritol, xylitol, sorbitol, mannitol, triethylamine bis-2-(hydroxypropyl)aniline, toluenediamine, aniline, isophoronediamine, diaminodicyclohexylmethane, glycolic acid, gluconic acid, DL-mandelic acid, citric acid, pyrimidine acid, alginic acid, salicylic acid, lauric acid, glycerol, trimethylhexanediamine or sorbic acid, preferably any one or a combination of at least two of glycerol, trimethylhexanediamine or sorbic acid; Preferably, the molecular weight of the polyoxypropylene triol is 200 to 8000 g / mol; Preferably, the molecular weight of the propylene oxide-ethylene oxide copolyether triol is 300 to 7000 g / mol; Preferably, the molecular weight of the polycaprolactone is 300 to 4000 g / mol; Preferably, the molecular weight of the tetrahydroxy polyether polyol is 300 to 500 g / mol; Preferably, the diamino polyether tetraol includes any one of ethylenediamine polyether tetraol, toluene diamine polyether tetraol, diaminodiphenylmethane polyether tetraol or meta-xylene diaminomethane polyether tetraol, or a combination of at least two thereof.

6. The foam stock solution for absorbing thick exudate according to claim 1, characterized in that: The surfactant includes any one or a combination of at least two of polyoxyethylene ether, fatty alcohol polyoxyethylene ether, isomeric alcohol ether, propylene glycol block polyether, oleyl alcohol polyoxyethylene ether, polyethylene glycol, fatty acid polyoxyethylene ester, sorbitan stearate, Tween or tripropionin; Preferably, the polyethylene glycol comprises any one of polyethylene glycol 1000, polyethylene glycol 2000 or polyethylene glycol 3000, or a combination of at least two thereof; Preferably, the isomeric alcohol ether includes any one of isomeric decanol polyoxyethylene ether, isomeric undecanol polyoxyethylene ether or isomeric tridecanol polyoxyethylene ether, or a combination of at least two thereof.

7. The foam stock solution for absorbing thick exudate according to claim 6, characterized in that: The surfactant is composed of a first surfactant, a second surfactant and a third surfactant; Wherein, the first surfactant comprises any one of polyoxyethylene ether, fatty alcohol polyoxyethylene ether, isomeric alcohol ether, propylene glycol block polyether or oleyl alcohol polyoxyethylene ether or a combination of at least two thereof; the second surfactant comprises polyethylene glycol and / or fatty acid polyoxyethylene ester; the third surfactant comprises any one of stearyl sorbitan, Tween or tripropionin or a combination of at least two thereof; Preferably, the mass ratio of the first surfactant, the second surfactant and the third surfactant is (2-4):(1-1.5):(0.5-1).

8. The foam stock solution for absorbing thick exudate according to claim 1, characterized in that: The lubricant includes any one or a combination of at least two of methylcellulose, carboxymethylcellulose, sodium carboxymethylcellulose, calcium carboxymethylcellulose, hydroxypropyl methylcellulose, hydroxymethylcellulose, hydroxyethyl cellulose, casein, calcium alginate, sodium alginate, gelatin, pectin, xanthan gum, carrageenan, xanthan gum, guar gum, gum arabic, hyaluronic acid, sodium hyaluronate, ceramide, niacinamide, chitosan or starch, preferably any one or a combination of at least two of calcium alginate, sodium alginate, hyaluronic acid or sodium hyaluronate.

9. The foam stock solution for absorbing thick exudate according to claim 8, characterized in that: The lubricant is composed of a first lubricant, a second lubricant and a third lubricant; Wherein, the first lubricant includes any one of methylcellulose, carboxymethylcellulose, sodium carboxymethylcellulose, calcium carboxymethylcellulose, hydroxypropyl methylcellulose, hydroxymethylcellulose, hydroxyethyl cellulose or casein, or a combination of at least two thereof; the second lubricant includes any one of calcium alginate, sodium alginate, hyaluronic acid or sodium hyaluronate, or a combination of at least two thereof; the third lubricant includes any one of gelatin, pectin, xanthan gum, carrageenan, xanthan gum, guar gum or gum arabic, or a combination of at least two thereof; Preferably, the mass ratio of the first lubricant, the second lubricant and the third lubricant is (2-3):(1-2):(0.1-1).

10. The foam stock solution for absorbing thick exudate according to claim 1, characterized in that: The catalyst includes any one of dimethylcyclohexylamine, ethanolamine, diethanolamine, triethanolamine, triisopropanolamine or methyldiethanolamine, or a combination of at least two thereof.

11. The foam stock solution for absorbing thick exudate according to claim 1, characterized in that: The isocyanate prepolymer is obtained by reacting an isocyanate monomer and a polyol; wherein the polyol comprises a polyether polyol and / or a polyester polyol, preferably a polyether polyol; Preferably, the polyether polyol comprises any one or a combination of at least two of polyoxypropylene polyol, sorbitol-based polyether polyol, sucrose-based polyether polyol, trimethylolpropane-based polyether polyol or glyceryl-based polyether polyol; Preferably, the raw materials for preparing the polyol include the following components by weight: 5 to 10 parts of low molecular alcohol, 70 to 90 parts of epoxy compound, and 0.1 to 1 part of catalyst A; Preferably, the small molecule alcohol includes any one or a combination of at least two of ethylene glycol, 1.3-propylene glycol, 1,3-butylene glycol, glycerol, trimethylolpropane, 1,4-butylene glycol, 1,6-hexanediol, neopentyl glycol, diethylene glycol, methylpentanediol, sucrose or sorbitol, preferably a combination of at least two of ethylene glycol, glycerol, trimethylolpropane, diethylene glycol, sucrose or sorbitol; Preferably, the epoxy compound comprises ethylene oxide and / or propylene oxide, preferably a combination of ethylene oxide and propylene oxide; Preferably, the catalyst A comprises potassium hydroxide and / or sodium hydroxide; Preferably, the raw materials for preparing the isocyanate prepolymer include the following components by weight: 40-50 parts of isocyanate monomer, 50-60 parts of polyether polyol, 0.1-1 parts of catalyst B, 0-1 parts of stabilizer, 0-5 parts of small molecule chain extender and 0-5 parts of cross-linking agent; Preferably, the isocyanate monomer includes any one or a combination of at least two of toluene diisocyanate, diphenylmethane diisocyanate, naphthalene diisocyanate, p-phenylene diisocyanate, dimethylbiphenyl diisocyanate, polymethylene polyphenyl isocyanate, 1,6-hexamethylene diisocyanate, trimethyl-1,6-hexamethylene diisocyanate, xylylene diisocyanate, tetramethyl-m-xylylene diisocyanate, isophorone diisocyanate, 1,4-cyclohexane diisocyanate, dicyclohexylmethane diisocyanate, methylcyclohexyl diisocyanate, cyclohexane dimethylene diisocyanate or norbornane diisocyanate; Preferably, the catalyst B comprises any one or a combination of at least two of dibutyltin dilaurate, stannous octoate, dibutyltin diacetate, triethylenediamine, bis(dimethylaminoethyl) ether, N-methylmorpholine or tetramethylethylenediamine; Preferably, the stabilizer includes any one or a combination of at least two of 2,6-di-tert-butyl-p-cresol, pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, 2-hydroxy-4-methoxybenzophenone or 2-(2H-benzotriazol-2-yl)-4,6-di-tert-amylphenol; Preferably, the small molecule chain extender includes any one or a combination of at least two of 1,4-butanediol, ethylene glycol, diethylene glycol, 1,6-hexanediol, neopentyl glycol, ethylenediamine, diethylenediamine or isophoronediamine, preferably a combination of at least two of 1,4-butanediol, ethylene glycol, 1,6-hexanediol or neopentyl glycol; Preferably, the crosslinking agent comprises any one of glycerol, trimethylolpropane, pentaerythritol, triethanolamine, triethylenetetramine or tetraethylenepentamine, or a combination of at least two of them, preferably a combination of at least two of trimethylolpropane, triethanolamine, triethylenetetramine or tetraethylenepentamine.

12. The foam stock solution for absorbing thick exudate according to claim 1 or 11, characterized in that: The isocyanate prepolymer is prepared by the following steps: A small molecule alcohol, an epoxy compound and a catalyst A are polymerized to obtain a polyether polyol; The polyether polyol, part of the isocyanate monomer, catalyst B and stabilizer are mixed to carry out a first reaction to obtain a reaction solution A; the reaction solution A and the remaining isocyanate monomer are mixed to carry out a second reaction to obtain a preliminary isocyanate prepolymer; The preliminary isocyanate prepolymer is mixed with a small molecule chain extender and / or a cross-linking agent, and subjected to a third reaction to obtain the isocyanate prepolymer; Preferably, in the process of preparing the polyol, the polymerization reaction temperature is 120-160° C., the polymerization reaction pressure is 0.2-0.4 MPa, and the polymerization reaction time is 4-8 h; Preferably, the part of the isocyanate monomers accounts for 30 to 50% of the total mass of the isocyanate monomers; Preferably, the temperature of the first reaction is 70-75°C and the time is 1-3h; Preferably, the NCO content of the prepolymer in the reaction solution A obtained in the first reaction is 11 to 14%; Preferably, the temperature of the second reaction is 75-80°C and the time is 0.5-1.5h; Preferably, the NCO content of the preliminary isocyanate prepolymer obtained by the second reaction is 6 to 9%; Preferably, the temperature of the third reaction is 60-70°C and the time is 0.5-1.5h; Preferably, the NCO content of the isocyanate prepolymer obtained by the third reaction is 6-8%.

13. A method for preparing a foam stock solution for absorbing thick exudate according to any one of claims 1 to 12, characterized in that: The preparation method comprises the following steps: Weigh a hydrophilic chain extender, a surfactant, a lubricant, a catalyst and water according to the formula, mix and stir to obtain a stock solution A; The isocyanate prepolymer is weighed according to the formula amount, mixed and stirred to obtain stock solution B.

14. The method for preparing a foam stock solution for absorbing thick exudate according to claim 13, characterized in that: In the preparation of the stock solution A, the temperature of the mixing and stirring is 10 to 30° C., and the rotation speed of the mixing and stirring is 100 to 500 rpm.

15. The method for preparing a foam stock solution for absorbing thick exudate according to claim 13, characterized in that: In the preparation of the stock solution B, the mixing temperature is 30-40° C., and the mixing speed is 100-500 rpm.

16. A finger-channel polyurethane foam, characterized in that: The polyurethane foam is formed by mixing stock solution A and stock solution B in the foam stock solution for absorbing thick exudate according to any one of claims 1 to 12, and then applying and foaming.

17. The finger channel polyurethane foam according to claim 16, characterized in that The polyurethane foam is a special foam with a finger-like pore structure; Preferably, the thickness of the polyurethane foam is 1 to 10 mm; Preferably, the average pore size of the polyurethane foam is 150 μm or more, preferably 200 to 550 μm, and more preferably 350 to 450 μm; Preferably, the surface open porosity of the polyurethane foam is 80% or more, preferably 85-95%, and more preferably 87-93%; Preferably, the density of the polyurethane foam is 80 kg / m 3 Above, preferably 85 to 120 kg / m 3 More preferably, 95 to 110 kg / m 3 ; Preferably, when the viscosity of the absorbed liquid is 100 to 300 mPa·s, the liquid absorption rate of the polyurethane foam is 0.050 mL / s or more, preferably 0.100 mL / s or more, and more preferably 0.200 mL / s or more; Preferably, when the viscosity of the absorbed liquid is 300 to 500 mPa·s, the liquid absorption rate of the polyurethane foam is 0.015 mL / s or more, preferably 0.030 mL / s or more, and more preferably 0.040 mL / s or more.

18. A method for preparing a finger-shaped channel polyurethane foam according to claim 16 or 17, characterized in that: The preparation method of the polyurethane foam comprises the following steps: The stock solution A and the stock solution B are mixed and stirred, and then extruded at a constant flow rate to obtain an extruded liquid; The extruded liquid is coated to form a flat foaming liquid, which is then dried to obtain a finger-shaped channel polyurethane foam.

19. The method for preparing the finger-shaped channel polyurethane foam according to claim 18, characterized in that: The mixing and stirring speed is 2000-5000 rpm, preferably 2500-4500 rpm; Preferably, the specific steps of coating include the following steps: Passing the extruded liquid through a roller blade coater to obtain a flat foaming liquid, and laminating and covering it with a silicon-treated release paper, wherein the pulling speeds of the foaming liquid and the release paper are kept synchronous; Preferably, the drying is carried out in a forced air oven at a drying temperature of 80-200°C.

20. Use of the foam stock solution for absorbing thick exudate according to any one of claims 1 to 12, or the finger-shaped channel polyurethane foam according to claim 16 or 17 in preparing a medical wound dressing or in preparing a core layer of a sanitary napkin.

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