An aqueous polyurethane for medical gloves, its preparation method and application

Abstract

The present invention provides an aqueous polyurethane for medical gloves, its preparation method and applications, belonging to the technical field of medical materials. The preparation method of the aqueous polyurethane for medical gloves is as follows: by weight, 35 - 40 parts of polyurethane A, 14 - 18 parts of polyurethane B, 8 - 12 parts of surfactant, 7 - 11 parts of modified filler, 2 - 5 parts of caprolactam and 70 - 75 parts of deionized water are mixed evenly and ultrasonicated for 15 - 20 min to obtain the aqueous polyurethane for medical gloves. The aqueous polyurethane of the present invention has high storage stability, good mechanical properties, excellent radiation resistance and solvent resistance.

Description

Technical Field

[0001] The present invention belongs to the technical field of medical materials, and particularly relates to an aqueous polyurethane for medical gloves, a preparation method thereof, and an application thereof. Background Art

[0002] Medical gloves are usually made of materials such as latex, nitrile rubber, or polyvinyl chloride. However, in recent years, aqueous polyurethane has gradually become a new choice due to its environmental protection and performance advantages. The application of aqueous polyurethane in medical gloves has many advantages, including environmental protection, good mechanical properties, and comfort.

[0003] When using aqueous polyurethane to prepare medical gloves, there are some technical problems that need to be solved. These problems mainly focus on the mechanical properties, chemical properties, biocompatibility, and comfort of the gloves: (1) Aqueous polyurethane may exhibit low tensile strength and elongation at break when preparing medical gloves, affecting the durability and comfort of the gloves. (2) Medical gloves may encounter problems of tearing and wear during use, affecting their service life. (3) Aqueous polyurethane gloves may perform poorly in terms of waterproofness and chemical resistance permeability, especially when contacting certain organic solvents. (4) Aqueous polyurethane gloves may have problems of skin irritation and allergic reactions, affecting the health of users. (5) The comfort of the gloves directly affects the user experience, and there may be problems such as poor touch or insufficient breathability.

[0004] In the prior art, in order to improve the comfort of aqueous polyurethane when preparing medical gloves, the formulation of polyurethane is adjusted, such as increasing the proportion of hard segments or using high-performance isocyanates and polyols, to improve the tensile strength and elongation at break of the material. However, increasing the proportion of hard segments can improve the tensile strength and elongation at break, but it may also affect other properties of the material, such as solvent resistance and radiation resistance.

[0005] Therefore, there is an urgent need for an aqueous polyurethane for medical gloves with excellent comprehensive performance. Summary of the Invention

[0006] The purpose of the present invention is to provide an aqueous polyurethane for medical gloves, a preparation method thereof, and an application thereof.

[0007] To achieve the above purpose, the present invention provides the following technical solutions:

[0008] An aqueous polyurethane for medical gloves, comprising the following components in parts by weight: 35-40 parts of polyurethane A, 14-18 parts of polyurethane B, 8-12 parts of surfactant, 7-11 parts of modified filler, 2-5 parts of caprolactam, and 70-75 parts of deionized water;

[0009] The preparation method of the polyurethane A comprises the following steps: by weight parts,

[0010] (1) Mix 0.3 - 0.5 parts of double - ended hydroxyl polyether modified silicone oil, 15 - 20 parts of polyether polyol, 5 - 8 parts of dimethylolpropionic acid, and 4 - 6 parts of 2,3,5,6 - tetramethyl - 1,4 - dioxane - 2,5 - diol, stir and heat to 94 - 98 °C, dehydrate under vacuum, cool down to 25 - 30 °C, add 45 - 50 parts of diisocyanate, stir and heat up to 80 - 85 °C, keep the temperature for reaction for 2 - 3 h, cool down to 50 - 55 °C, continue to add 50 - 55 parts of acetone, stir and heat up to 74 - 76 °C for reaction for 7 - 9 h, then cool down to 15 - 20 °C, add 3.0 - 3.5 parts of triethylamine and 200 - 220 parts of acetone, stir for 40 - 50 min to obtain prepolymer A; the diisocyanate is selected from one or more of toluene diisocyanate, isophorone diisocyanate, or hexamethylene diisocyanate;

[0011] (2) Under the stirring condition of 1200 - 1400 r / min, add 450 - 460 parts of ice - water mixture to prepolymer A, stir for 10 - 15 min, then adjust the rotation speed to 500 - 600 r / min, add a solution composed of 2 - 2.5 parts of ethylenediamine and 10 - 12 parts of water, and continue to stir for 4 - 5 h to obtain emulsion A;

[0012] (3) Heat emulsion A to 40 - 45 °C and remove acetone to obtain polyurethane A.

[0013] Furthermore, the polyether polyol includes polyether diol with a hydroxyl number of 36 - 39 mgKOH / g, polyether triol with a hydroxyl number of 535 mgKOH / g, and polyether diol with a hydroxyl number of 153 - 188 mgKOH / g in a weight ratio of (1.3 - 1.5):(0.2 - 0.5):1.

[0014] In order to ensure that medical gloves are not easily damaged during stretching, the water - borne polyurethane for preparing medical gloves requires a relatively high tensile strength. In the prior art, the tensile strength of water - borne polyurethane is not ideal. The present invention uses double - ended hydroxyl polyether modified silicone oil to prepare polyurethane A, which can improve the tensile strength of water - borne polyurethane for medical gloves. The double - ended hydroxyl polyether modified silicone oil has good flexibility, which can improve the flexibility of polyurethane, making it not easily break during stretching. The hydroxyl functional groups at both ends can react with the isocyanate groups in the polyurethane matrix, enhancing the interfacial bonding force. However, the elongation at break of water - borne polyurethane is not ideal.

[0015] Furthermore, by weight parts, the preparation method of polyurethane B includes the following steps:

[0016] (1) Mix 15 - 20 parts of polyester polyol, 5 - 8 parts of dimethylolpropionic acid, and 4 - 6 parts of 2,3,5,6 - tetramethyl - 1,4 - dioxane - 2,5 - diol, stir and heat to 94 - 98 °C, dehydrate under vacuum at -0.1 MPa for 2 - 3 h, cool down to 25 - 30 °C, add 45 - 50 parts of isophorone diisocyanate, stir and heat up to 80 - 85 °C, keep the temperature for reaction for 2 - 3 h, cool down to 50 - 55 °C, continue to add 50 - 55 parts of acetone, stir and heat up to 74 - 76 °C for reaction for 7 - 9 h, then cool down to 15 - 20 °C, add 3.0 - 3.5 parts of triethylamine and 200 - 220 parts of acetone, stir for 40 - 50 min to obtain prepolymer B;

[0017] (2) Under the stirring condition of 1200 - 1400 r / min, add 450 - 460 parts of ice - water mixture into prepolymer B, stir for 10 - 15 min, then adjust the rotation speed to 500 - 600 r / min, add a solution composed of 2 - 2.5 parts of ethylenediamine and 10 - 12 parts of water, continue to stir for 4 - 5 h to obtain emulsion B;

[0018] (3) Heat emulsion B to 40 - 45 °C, remove acetone under the condition of -0.09 MPa to obtain polyurethane B.

[0019] Furthermore, the polyester polyol includes polybutylene adipate diol with a molecular weight of 600, a hydroxyl value of 185 - 205 mgKOH / g, polybutylene adipate diol with a molecular weight of 2000, a hydroxyl value of 53 - 59 mgKOH / g, and polybutylene adipate diol with a molecular weight of 4000, a hydroxyl value of 26 - 30 mgKOH / g in a weight ratio of (1.2 - 1.4):1:(0.3 - 0.5).

[0020] In order to improve the elongation at break of the water - borne polyurethane, the present invention mixes polyurethane A prepared from polyether polyol and polyurethane B prepared from polyester polyol, which can improve the elongation at break of the water - borne polyurethane. Under this condition, the puncture strength of the water - borne polyurethane for medical gloves is also improved.

[0021] Medical gloves are generally disinfected by irradiation, but it is easy to cause glove aging and lead to performance degradation. In the system of the present invention, when polyurethane A and polyurethane B are respectively prepared using a polyether polyol with a specific composition ratio and a polyester polyol with a specific composition ratio, the tensile strength and elongation at break of the waterborne polyurethane after irradiation can be improved. The main reason is that when polyurethane A and polyurethane B are respectively prepared using a polyether polyol with a specific composition ratio and a polyester polyol with a specific composition ratio, after mixing, they can interact with each other during the stretching process, disperse stress, prevent stress concentration, thereby increasing the elongation at break. The polyester polyol provides strength, and the polyether polyol provides flexibility. The combination of the two can achieve a balance between strength and flexibility. An appropriate proportion of polyether polyol and polyester polyol can promote the complexity of the crosslinked network system in the material and improve its stability under irradiation conditions.

[0022] Further, the surfactant is Tween 60, nonylphenol polyoxyethylene ether (Shandong Xiaoqingxin Chemical Co., Ltd., model NP - 40), and sodium dioctyl sulfosuccinate (CAS: 14481 - 60 - 8) with a weight ratio of 1:(1.2 - 1.5):(0.5 - 0.8).

[0023] Adding both polyurethane A and polyurethane B in the present invention will result in poor storage stability of the waterborne polyurethane. By using a specific surfactant, the stability of the waterborne polyurethane can be improved.

[0024] Further, the preparation method of the modified filler includes the following steps:

[0025] (1) Mix nano - calcium carbonate, nano - zinc oxide, and nano - silicon dioxide to obtain a mixed filler;

[0026] (2) Mix the mixed filler, absolute ethanol, and γ - aminopropyltriethoxysilane with a weight ratio of 1:(7 - 9):(0.2 - 0.5), stir and react at 55 - 60 °C for 4 - 6 h, filter, wash, and dry to obtain a silane - modified filler;

[0027] (3) Mix the silane - modified filler, absolute ethanol, glycidyl methacrylate, and azobisisobutyronitrile with a weight ratio of 1:(6 - 8):(0.12 - 0.17):(0.01 - 0.03), heat and stir at 65 - 70 °C for 8 - 10 h, filter, wash, and dry to obtain the modified filler.

[0028] Further, the particle size of the nano - calcium carbonate is 50 - 100 nm, the average particle size is 70 nm, and the specific surface area is 40 - 50 m 2 / g; the particle size of the nano - zinc oxide is 30 - 50 nm, the average particle size is 45 nm, and the specific surface area is 15 - 30 m 2 / g; the particle size of the nano-silica is 5 - 20 nm, the average particle size is 15 nm, and the specific surface area is 200 - 250 m 2 / g.

[0029] Furthermore, the weight ratio of nano-calcium carbonate, nano-zinc oxide and nano-silica is 1:(0.3 - 0.5):(1.5 - 1.8).

[0030] Medical gloves need to have the property of solvent resistance. This is mainly because in a medical environment, gloves may come into contact with various chemical substances and solvents, which may damage the structural integrity of the gloves and affect their protective functions. In this invention, an attempt was made to add nano-fillers to improve the solvent resistance of waterborne polyurethane, but the effect was not ideal. By modifying the nano-fillers, the solvent resistance of waterborne polyurethane can be better improved. The analysis is that by modifying the fillers, the compatibility with other components in the system can be improved, a strong interfacial bond is formed between the nano-fillers and the polyurethane matrix, enhancing the interfacial strength of the matrix, thereby improving the solvent resistance of the material.

[0031] The present invention provides a method for preparing the waterborne polyurethane for medical gloves. The preparation method includes the following steps: mixing polyurethane A, polyurethane B, surfactant, modified filler, caprolactam and deionized water evenly, and ultrasonicating for 15 - 20 min to obtain the waterborne polyurethane for medical gloves.

[0032] The present invention provides the application of the waterborne polyurethane in the preparation of medical gloves.

[0033] Compared with the prior art, the advantages and beneficial effects of the present invention are as follows:

[0034] 1. The present invention uses a double-ended hydroxyl polyether modified silicone oil to prepare polyurethane A, which can improve the tensile strength of the waterborne polyurethane for medical gloves.

[0035] 2. The present invention blends polyurethane A prepared from polyether polyol and polyurethane B prepared from polyester polyol, which can improve the elongation at break of the waterborne polyurethane. At the same time, the puncture strength of the waterborne polyurethane for medical gloves is improved.

[0036] 3. When the present invention uses a polyether polyol with a specific composition ratio and a polyester polyol with a specific composition ratio, the tensile strength and elongation at break of the waterborne polyurethane after irradiation can be improved.

[0037] 4. The present invention uses a specific surfactant, which can improve the stability of the waterborne polyurethane.

[0038] 5. The present invention can better improve the solvent resistance of the waterborne polyurethane by modifying the nano-fillers. Detailed implementation mode

[0039] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Apparently, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0040] The raw materials of the present invention are purchased from the following manufacturers:

[0041] The double-end hydroxyl polyether modified silicone oil is purchased from Qingdao Baisenmao New Materials Co., Ltd., with the model BM-13667.

[0042] The polyether diol with a hydroxyl number of 36-39 mgKOH / g is purchased from Xuzhou Yihuiyang New Materials Co., Ltd., DL-3000D.

[0043] The polyether triol with a hydroxyl number of 535 mgKOH / g is purchased from Arkema France, with the model TO330.

[0044] The polyether diol with a hydroxyl number of 153-188 mgKOH / g is purchased from Jining Tangyi Chemical Co., Ltd., HSH-310.

[0045] The polybutylene adipate diol with a molecular weight of 600 and a hydroxyl value of 185-205 mgKOH / g, the polybutylene adipate diol with a molecular weight of 2000 and a hydroxyl value of 53-59 mgKOH / g, and the polybutylene adipate diol with a molecular weight of 4000 and a hydroxyl value of 26-30 mgKOH / g are all purchased from Greenlink (Jining) Chemical Technology Co., Ltd.

[0046] The nonylphenol polyoxyethylene ether is purchased from Shandong Xiaoqingxin Chemical Co., Ltd., with the model NP-40.

[0047] Sodium dioctadecyl sulfosuccinamate, CAS: 14481-60-8.

[0048] The nano calcium carbonate in the embodiments of the present invention is all purchased from Shanghai Gerunya Nano Materials Co., Ltd. The nano zinc oxide is all purchased from Zhejiang Zhitaina Micro New Materials Co., Ltd. The nano silicon dioxide is all purchased from Beijing Dekedaojin Technology Co., Ltd.

[0049] Example 1

[0050] This example provides an aqueous polyurethane for medical gloves, which includes the following components in parts by weight: 37 parts of polyurethane A, 16 parts of polyurethane B, 9 parts of surfactant, 9 parts of modified filler, 4 parts of caprolactam, and 73 parts of deionized water.

[0051] The preparation method of the polyurethane A includes the following steps: by weight,

[0052] (1) Mix 0.4 parts of double-ended hydroxyl polyether modified silicone oil, 17 parts of polyether polyol, 6 parts of dimethylolpropionic acid, and 5 parts of 2,3,5,6-tetramethyl-1,4-dioxane-2,5-diol (CAS: 23147-57-1), stir and heat to 95 °C, dehydrate under vacuum at -0.1 MPa for 2.5 h, cool to 27 °C, add 47 parts of isophorone diisocyanate, stir and heat up to 82 °C, keep the temperature for reaction for 2.5 h, cool to 52 °C, continue to add 52 parts of acetone, stir and heat up to 75 °C for reaction for 8 h, then cool to 18 °C, add 3.2 parts of triethylamine and 210 parts of acetone, stir for 45 min to obtain prepolymer A; the polyether polyol includes polyether diol with a hydroxyl number of 36 - 39 mgKOH / g, polyether triol with a hydroxyl number of 535 mgKOH / g, and polyether diol with a hydroxyl number of 153 - 188 mgKOH / g in a weight ratio of 1.4:0.4:1.

[0053] (2) Under the stirring condition of 1300 r / min, add 455 parts of ice-water mixture to prepolymer A, stir for 12 min, then adjust the rotation speed to 550 r / min, add a solution composed of 2.3 parts of ethylenediamine and 11 parts of water, and continue to stir for 4.5 h to obtain emulsion A;

[0054] (3) Heat emulsion A to 42 °C, and remove acetone under the condition of -0.09 MPa to obtain polyurethane A.

[0055] By weight, the preparation method of polyurethane B includes the following steps:

[0056] (1) Mix 17 parts of polyester polyol, 6 parts of dimethylolpropionic acid, and 5 parts of 2,3,5,6-tetramethyl-1,4-dioxane-2,5-diol, stir and heat to 95 °C, dehydrate under vacuum at -0.1 MPa for 2.5 h, cool to 27 °C, add 47 parts of isophorone diisocyanate, stir and heat up to 82 °C, keep the temperature for reaction for 2.6 h, cool to 52 °C, continue to add 52 parts of acetone, stir and heat up to 75 °C for reaction for 8 h, then cool to 17 °C, add 3.2 parts of triethylamine and 210 parts of acetone, stir for 45 min to obtain prepolymer B; the polyester polyol includes polybutylene adipate diol with a molecular weight of 600 and a hydroxyl value of 185 - 205 mgKOH / g, polybutylene adipate diol with a molecular weight of 2000 and a hydroxyl value of 53 - 59 mgKOH / g, and polybutylene adipate diol with a molecular weight of 4000 and a hydroxyl value of 26 - 30 mgKOH / g in a weight ratio of 1.3:1:0.4.

[0057] (2) Under the stirring condition of 1300 r / min, add 455 parts of ice-water mixture to prepolymer B, stir for 12 min, then adjust the rotation speed to 550 r / min, add a solution composed of 2.2 parts of ethylenediamine and 11 parts of water, and continue to stir for 4.5 h to obtain emulsion B;

[0058] (3) Heat emulsion B to 42 °C and remove acetone under the condition of -0.09 MPa to obtain polyurethane B.

[0059] The surfactant is Tween 60, nonylphenol polyoxyethylene ether and sodium dioctadecyl sulfosuccinamate with a weight ratio of 1:1.4:0.6.

[0060] The preparation method of the modified filler includes the following steps:

[0061] (1) Mix nano calcium carbonate, nano zinc oxide and nano silicon dioxide with a weight ratio of 1:0.4:1.7 to obtain a mixed filler; the particle size of nano calcium carbonate is 50 - 100 nm, the average particle size is 70 nm, and the specific surface area is 40 - 50 m 2 / g; the particle size of nano zinc oxide is 30 - 50 nm, the average particle size is 45 nm, and the specific surface area is 15 - 30 m 2 / g; the particle size of nano silicon dioxide is 5 - 20 nm, the average particle size is 15 nm, and the specific surface area is 200 - 250 m 2 / g.

[0062] (2) Mix the mixed filler, absolute ethanol and γ-aminopropyltriethoxysilane with a weight ratio of 1:8:0.4, stir and react at 52 °C for 5 h, filter, wash, and dry to obtain a silane-modified filler;

[0063] (3) Mix the silane-modified filler, absolute ethanol, glycidyl methacrylate and azobisisobutyronitrile with a weight ratio of 1:7:0.15:0.02, heat and stir at 68 °C for 9 h, filter, wash, and dry to obtain the modified filler.

[0064] The weight ratio of nano calcium carbonate, nano zinc oxide and nano silicon dioxide is 1:0.4:1.7.

[0065] The preparation method of the aqueous polyurethane for medical gloves includes the following steps: Mix polyurethane A, polyurethane B, surfactant, modified filler, caprolactam and deionized water evenly, and ultrasonicate for 18 min to obtain the aqueous polyurethane for medical gloves.

[0066] Example 2

[0067] This embodiment provides an aqueous polyurethane for medical gloves, which comprises the following components in parts by weight: 35 parts of polyurethane A, 18 parts of polyurethane B, 8 parts of surfactant, 7 parts of modified filler, 2 parts of caprolactam, and 75 parts of deionized water.

[0068] The preparation method of the polyurethane A comprises the following steps: by weight,

[0069] (1) Mix 0.3 part of double-end hydroxyl polyether modified silicone oil, 20 parts of polyether polyol, 5 parts of dimethylolpropionic acid, and 6 parts of 2,3,5,6-tetramethyl-1,4-dioxane-2,5-diol, stir and heat to 94°C, carry out vacuum dehydration for 3 h under the condition of -0.1 MPa, cool down to 25°C, add 50 parts of isophorone diisocyanate, stir and heat up to 80°C, keep the temperature for reaction for 3 h, cool down to 55°C, continue to add 50 parts of acetone, stir and heat up to 76°C for reaction for 7 h, then cool down to 20°C, add 3.0 parts of triethylamine and 220 parts of acetone, stir for 40 min to obtain prepolymer A; the polyether polyol comprises polyether diol with a hydroxyl number of 36 - 39 mgKOH / g, polyether triol with a hydroxyl number of 535 mgKOH / g, and polyether diol with a hydroxyl number of 153 - 188 mgKOH / g in a weight ratio of 1.3:0.5:1.

[0070] (2) Under the stirring condition of 1200 r / min, add 460 parts of ice-water mixture to prepolymer A, stir for 10 min, then adjust the rotation speed to 600 r / min, add a solution composed of 2 parts of ethylenediamine and 12 parts of water, and continue to stir for 4 h to obtain emulsion A;

[0071] (3) Heat emulsion A to 45°C, and remove acetone under the condition of -0.09 MPa to obtain polyurethane A.

[0072] By weight, the preparation method of the polyurethane B comprises the following steps:

[0073] (1) Mix 15 parts of polyester polyol, 8 parts of dimethylolpropionic acid, and 4 parts of 2,3,5,6 - tetramethyl - 1,4 - dioxane - 2,5 - diol, stir and heat to 98 °C, conduct vacuum dehydration for 3 h under the condition of - 0.1 MPa, cool down to 25 °C, add 50 parts of isophorone diisocyanate, stir and heat up to 80 °C, keep the temperature for reaction for 3 h, cool down to 50 °C, continue to add 55 parts of acetone, stir and heat up to 74 °C for reaction for 9 h, then cool down to 15 °C, add 3.5 parts of triethylamine and 220 parts of acetone, stir for 40 min to obtain prepolymer B; the polyester polyol includes polybutylene adipate diol with a molecular weight of 600 and a hydroxyl value of 185 - 205 mgKOH / g, polybutylene adipate diol with a molecular weight of 2000 and a hydroxyl value of 53 - 59 mgKOH / g, and polybutylene adipate diol with a molecular weight of 4000 and a hydroxyl value of 26 - 30 mgKOH / g in a weight ratio of 1.2:1:0.5.

[0074] (2) Under the stirring condition of 1400 r / min, add 450 parts of ice - water mixture to prepolymer B, stir for 15 min, then adjust the rotation speed to 500 r / min, add a solution composed of 2.5 parts of ethylenediamine and 12 parts of water, and continue to stir for 4 h to obtain emulsion B;

[0075] (3) Heat emulsion B to 45 °C and remove acetone under the condition of - 0.09 MPa to obtain polyurethane B.

[0076] The surfactant is Tween 60, nonylphenol polyoxyethylene ether, and sodium octadecyl sulfosuccinamate in a weight ratio of 1:1.2:0.8.

[0077] The preparation method of the modified filler includes the following steps:

[0078] (1) Mix nano - calcium carbonate, nano - zinc oxide, and nano - silicon dioxide in a weight ratio of 1:0.3:1.8 to obtain a mixed filler; the particle size of nano - calcium carbonate is 50 - 100 nm, the average particle size is 70 nm, and the specific surface area is 40 - 50 m 2 / g; the particle size of nano - zinc oxide is 30 - 50 nm, the average particle size is 45 nm, and the specific surface area is 15 - 30 m 2 / g; the particle size of nano - silicon dioxide is 5 - 20 nm, the average particle size is 15 nm, and the specific surface area is 200 - 250 m 2 / g.

[0079] (2) Mix the mixed filler, absolute ethanol, and γ - aminopropyltriethoxysilane in a weight ratio of 1:7:0.2, stir and react at 60 °C for 4 h, filter, wash, and dry to obtain the silane - modified filler;

[0080] (3) Mix the silane-modified filler, anhydrous ethanol, glycidyl methacrylate, and azobisisobutyronitrile in a weight ratio of 1:6:0.12:0.03, heat and stir at 65 °C for 10 h, filter, wash, and dry to obtain the modified filler.

[0081] The weight ratio of nano calcium carbonate, nano zinc oxide, and nano silicon dioxide is 1:0.3:1.8.

[0082] The preparation method of the aqueous polyurethane for medical gloves includes the following steps: Mix polyurethane A, polyurethane B, surfactant, modified filler, caprolactam, and deionized water evenly, and ultrasonicate for 15 min to obtain the aqueous polyurethane for medical gloves.

[0083] Comparative Example 1

[0084] The difference between this comparative example and Example 1 is that 37 parts of polyurethane A and 16 parts of polyurethane B are replaced with 30 parts of polyurethane A and 23 parts of polyurethane B.

[0085] Comparative Example 2

[0086] The difference between this comparative example and Example 1 is that the polyether polyol includes polyether diol with a hydroxyl number of 36 - 39 mgKOH / g, polyether triol with a hydroxyl number of 535 mgKOH / g, and polyether diol with a hydroxyl number of 153 - 188 mgKOH / g in a weight ratio of 1:1:1.

[0087] Comparative Example 3

[0088] The difference between this comparative example and Example 1 is that the polyester polyol includes polybutylene adipate diol with a molecular weight of 600 and a hydroxyl value of 185 - 205 mgKOH / g, polybutylene adipate diol with a molecular weight of 2000 and a hydroxyl value of 53 - 59 mgKOH / g, and polybutylene adipate diol with a molecular weight of 4000 and a hydroxyl value of 26 - 30 mgKOH / g in a weight ratio of 1:1:1.

[0089] Comparative Example 4

[0090] The difference between this comparative example and Example 1 is that the surfactant is Tween 60, nonylphenol polyoxyethylene ether, and sodium dioctyl sulfosuccinate in a weight ratio of 1:1:1.

[0091] Comparative Example 5

[0092] The difference between this comparative example and Example 1 is that the surfactant is Span 80, sodium dodecyl sulfate, and sodium dodecyl sulfate in a weight ratio of 1:1.4:0.6.

[0093] Comparative Example 6

[0094] The difference between this comparative example and Example 1 is that the weight ratio of nano calcium carbonate, nano zinc oxide and nano silicon dioxide is 1:1:1. The particle size of nano calcium carbonate is 50-100 nm, the average particle size is 70 nm, and the specific surface area is 40-50 m 2 / g; the particle size of nano zinc oxide is 30-50 nm, the average particle size is 45 nm, and the specific surface area is 15-30 m 2 / g; the particle size of nano silicon dioxide is 5-20 nm, the average particle size is 15 nm, and the specific surface area is 200-250 m 2 / g.

[0095] Comparative Example 7

[0096] The difference between this comparative example and Example 1 is that the particle size of nano calcium carbonate is 150-200 nm, the average particle size is 165 nm, and the specific surface area is 10-20 m 2 / g; the particle size of nano zinc oxide is 70-100 nm, the average particle size is 85 nm, and the specific surface area is 5-10 m 2 / g; the particle size of nano silicon dioxide is 45-60 nm, the average particle size is 55 nm, and the specific surface area is 100-140 m 2 / g.

[0097] Performance Test

[0098] The aqueous polyurethane for medical gloves prepared using Examples 1-2 and Comparative Examples 1-7 was used to prepare film samples by dipping method with a glass mold having a diameter of 40 mm. After the film was formed, it was dried in a drying oven at 90 °C for 35 min to obtain samples with a thickness of 20 μm. Performance tests were carried out.

[0099] (1) Tensile property test: It was tested using a universal tensile testing machine according to the method described in GB / T 528-2009. The sample was a dumbbell-shaped thin sheet, the tensile rate was 300 mm / min, and the temperature was 25 °C.

[0100] (2) Puncture strength test: Tested with reference to the standard of GB / T10004-2008. The sample was cut into strips with scissors, and a test piece with a width of 100 mm was installed on the sample film fixing clamp ring. Then, a steel needle with a diameter of 1.0 mm and a tip radius of 0.1 mm was used to pierce it at a speed of (50±5) mm / min, and the maximum load when the steel needle penetrated the test piece was read; 3 points were tested and the arithmetic mean was taken.

[0101] (3) Solvent resistance: The sample was completely immersed in 350 mPa·S silicone oil for 48 h, and the tensile property was measured.

[0102] (4) Storage stability: Take 100 mL of the aqueous polyurethane prepared in Examples 1-2 and Comparative Examples 1-7, seal and package it with a transparent sample bottle, and place it in a constant temperature drying oven. After 7 days at 50 °C, take it out and place it at 25 °C for 3 h, visually observe its appearance state, and observe whether there is precipitation.

[0103] Table 1 Performance test results

[0104]

[0105] From the above performance test results, it can be seen that the aqueous polyurethanes in Examples 1-2 have excellent comprehensive properties, especially the comprehensive properties of Example 1 are the most prominent. This is mainly due to the synergistic compounding of various components.

[0106] In the comparative examples, since the necessary technical solutions were not adopted, their performance in the corresponding performance tests was significantly worse than that of the examples. In Comparative Example 1, the ratio of polyurethane A and polyurethane B was changed, and it can be seen that the tensile strength and elongation at break decreased, proving that the compounding scheme of polyurethane A and polyurethane B has an important impact on the tensile strength and elongation at break of the aqueous polyurethane. In Comparative Examples 2 and 3, the ratio of polyether polyol and polyester polyol was changed, and it can be seen from the results that the radiation resistance of the aqueous polyurethane decreased; in Comparative Examples 4 and 5, the raw materials and ratios of the surfactant were changed, affecting the stability of the aqueous polyurethane; in Comparative Examples 6 and 7, the ratio and parameters of the filler were changed, and the solvent resistance of the aqueous polyurethane decreased. The above experimental results further prove the importance of the technical solutions defined in the present invention for its technical effects.

[0107] The above is the preferred embodiment of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A water-based polyurethane for medical gloves, characterized in that: The composition comprises, by weight: 35-40 parts of polyurethane A, 14-18 parts of polyurethane B, 8-12 parts of surfactant, 7-11 parts of modified filler, 2-5 parts of caprolactam and 70-75 parts of deionized water; The preparation method of polyurethane A comprises: (1) Mix 0.3-0.5 parts of double-terminal hydroxyl polyether modified silicone oil, 15-20 parts of polyether polyol, 5-8 parts of dimethylol propionic acid, and 4-6 parts of 2,3,5,6-tetramethyl-1,4-dioxacyclo-2,5-diol, stir and heat to 94-98°C, vacuum dehydrate, cool to 25-30°C, add 45-50 parts of diisocyanate, stir and heat to 80-85°C, and keep warm for 2-3 hours , cool to 50-55°C, continue to add 50-55 parts of acetone, stir and heat to 74-76°C for reaction for 7-9h, then cool to 15-20°C, add 3.0-3.5 parts of triethylamine and 200-220 parts of acetone, stir for 40-50min to obtain prepolymer A; the diisocyanate is selected from one or more of toluene diisocyanate, isophorone diisocyanate or hexamethylene diisocyanate; (2) Under stirring conditions of 1200-1400 r / min, add 450-460 parts of ice-water mixture to prepolymer A, stir for 10-15 minutes, then adjust the speed to 500-600 r / min, add a solution consisting of 2-2.5 parts of ethylenediamine and 10-12 parts of water, and continue stirring for 4-5 hours to obtain emulsion A; (3) heating emulsion A to 40-45°C and removing acetone to obtain polyurethane A; The polyether polyol includes a polyether diol having a hydroxyl number of 36-39 mgKOH / g, a polyether triol having a hydroxyl number of 535 mgKOH / g, and a polyether diol having a hydroxyl number of 153-188 mgKOH / g in a weight ratio of (1.3-1.5):(0.2-0.5):1; The preparation method of polyurethane B comprises: (1) 15-20 parts of polyester polyol, 5-8 parts of dimethylol propionic acid and 4-6 parts of 2,3,5,6-tetramethyl-1,4-dioxacyclo-2,5-diol are mixed, heated to 94-98°C with stirring, vacuum dehydration is performed, the temperature is lowered to 25-30°C, 45-50 parts of isophorone diisocyanate are added, the temperature is raised to 80-85°C with stirring, the temperature is kept for reaction for 2-3 hours, the temperature is lowered to 50-55°C, 50-55 parts of acetone are added, the temperature is raised to 74-76°C with stirring and the reaction is carried out for 7-9 hours, the temperature is then lowered to 15-20°C, 3.0-3.5 parts of triethylamine and 200-220 parts of acetone are added, and the temperature is stirred for 40-50 minutes to obtain prepolymer B; (2) Under stirring conditions of 1200-1400 r / min, add 450-460 parts of ice-water mixture to prepolymer B, stir for 10-15 min, then adjust the speed to 500-600 r / min, add a solution consisting of 2-2.5 parts of ethylenediamine and 10-12 parts of water, and continue stirring for 4-5 hours to obtain emulsion B; (3) heating emulsion B to 40-45°C and removing acetone to obtain polyurethane B; The polyester polyol includes polybutylene adipate diol having a molecular weight of 600 and a hydroxyl value of 185-205 mgKOH / g, polybutylene adipate diol having a molecular weight of 2000 and a hydroxyl value of 53-59 mgKOH / g, and polybutylene adipate diol having a molecular weight of 4000 and a hydroxyl value of 26-30 mgKOH / g in a weight ratio of (1.2-1.4):1:(0.3-0.5).

2. The aqueous polyurethane for medical gloves according to claim 1, characterized in that: The surfactant is a mixture of Tween 60, nonylphenol polyoxyethylene ether and disodium octadecyl succinamide sulfonate in a weight ratio of 1: (1.2-1.5): (0.5-0.8).

3. The aqueous polyurethane for medical gloves according to claim 1, characterized in that: The preparation method of the modified filler comprises the following steps: (1) mixing nano calcium carbonate, nano zinc oxide and nano silicon dioxide to obtain a mixed filler; (2) Mixing a mixed filler, anhydrous ethanol and γ-aminopropyltriethoxysilane in a weight ratio of 1: (7-9): (0.2-0.5), stirring and reacting at 55-60° C. for 4-6 hours, filtering, washing and drying to obtain a silane-modified filler; (3) Mix silane-modified filler, anhydrous ethanol, glycidyl methacrylate and azobisisobutyronitrile in weight parts of 1: (6-8): (0.12-0.17): (0.01-0.03), heat and stir at 65-70° C. for 8-10 h, filter, wash and dry to obtain a modified filler.

4. The aqueous polyurethane for medical gloves according to claim 3, characterized in that: The particle size of nano calcium carbonate is 50-100nm, the average particle size is 70nm, and the specific surface area is 40-50 m 2 / g; the particle size of nano zinc oxide is 30-50nm, the average particle size is 45nm, and the specific surface area is 15-30m 2 / g; the particle size of nano-silicon dioxide is 5-20nm, the average particle size is 15nm, and the specific surface area is 200-250 m 2 / g.

5. The aqueous polyurethane for medical gloves according to claim 3, characterized in that: The weight ratio of nano calcium carbonate, nano zinc oxide and nano silicon dioxide is 1: (0.3-0.5): (1.5-1.8).

6. A method for preparing the aqueous polyurethane for medical gloves according to any one of claims 1 to 5, characterized in that: The preparation method comprises the following steps: uniformly mixing polyurethane A, polyurethane B, surfactant, modified filler, caprolactam and deionized water, and ultrasonicating for 15-20 minutes to obtain water-based polyurethane for medical gloves.

7. Use of the waterborne polyurethane according to any one of claims 1 to 5 in the preparation of medical gloves.

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