A modified polyurethane dispersion and a method for its preparation

Abstract

The present application relates to a kind of modified polyurethane dispersions and its preparation method, the modified water-based polyurethane dispersion includes the following raw materials: polyisocyanate, macromolecular polyol, silicon diol, hydrophilic chain extender, modified monomer.The printed coating prepared by the modified polyurethane dispersion of the present application has excellent water wash resistance on silicone oil treated cloth.

Description

Technical Field

[0001] This invention relates to the field of polyurethane dispersions, and in particular to a modified polyurethane dispersion that achieves moisture permeability on silicone oil-treated cloth without affecting adhesion and water-based properties, and a method for preparing the same. Background Technology

[0002] Waterborne polyurethane dispersions can form a dense, transparent film on fabric surfaces. This film exhibits good adhesion and elasticity, making it a common application for fabric surface treatment. Printing with waterborne polyurethane dispersions requires only drying, eliminating the need for washing. This simple process reduces solvent and wastewater emissions, meeting environmental protection requirements and making it a frequently used method in the printing industry.

[0003] As people's living standards improve, their requirements for clothing and footwear materials are increasing. Therefore, the colorfastness or wash fastness of prints on clothing and footwear materials has become a focus of attention. Currently, the substrates used for printing are generally cotton fabric, cotton-blend fabric, and increasingly, substrates treated with heavy silicone oil. Ordinary water-based resins exhibit relatively poor fastness on these substrates when used for printing.

[0004] Most clothing printed with plastisol is not breathable, especially in summer when wearing T-shirts with large-area prints is very stuffy. Therefore, it is very important to invent a print that can expel sweat vapor in time when the body sweats, thus increasing comfort.

[0005] With the development of waterborne polyurethane technology, hydrophilic group penetration technology has been increasingly studied in the field of waterproofing and breathability. Patent CN114437307A describes waterborne polyurethane dispersions, coating compositions and their applications, which enhance breathability by introducing diols with polyoxyethylene alkyl side chains. However, while this group improves breathability, it also leads to a decrease in water washability.

[0006] How to ensure good transparency while maintaining the washability and adhesion of polyurethane printing has become a key research focus in the industry. Summary of the Invention

[0007] In view of the above problems, the present invention provides a modified waterborne polyurethane dispersion and its preparation method, wherein the printed products made therefrom have excellent moisture permeability and excellent adhesion and washability on silicone oil treated fabrics.

[0008] To achieve the above objectives, the present invention adopts the following technical solution:

[0009] A modified polyurethane dispersion comprising the following raw materials by weight percentage:

[0010] Component 1) Polyisocyanate 30-50 wt%, preferably 32-44 wt%;

[0011] Component 2) 40-60 wt% macromolecular polyol, preferably 45-58 wt%;

[0012] Component 3) Silicon diol 1-6 wt%;

[0013] Component 4) Hydrophilic chain extender 4-6 wt%;

[0014] Based on the total mass of components 1)-4) being 100%;

[0015] In this invention, the raw materials further include: component 5) the amount of polyamine chain extender is 3-6 wt% of the total mass of components 1)-4);

[0016] In this invention, the raw materials further include: component 6) modified monomer, the amount of which is 125-140% of the total mass of components 1)-4);

[0017] The modified monomers include hard monomers containing double bonds, soft monomers containing double bonds, and sulfonate monomers containing double bonds; preferably, the amount of hard monomers containing double bonds is 15-30 wt% of the modified monomer mass; the amount of soft monomers containing double bonds is 55-75 wt% of the modified monomer mass; and the amount of sulfonate monomers containing double bonds is 7-17 wt% of the modified monomer mass.

[0018] The raw materials also include: component 7) an initiator, used in an amount of 0.05-0.3% of the total mass of the modified monomers, preferably 0.1-0.2%;

[0019] In this invention, the raw materials further include: component 8) catalyst, the amount of which is 0.01-1% of the total mass of components 1)-4).

[0020] In this invention, the polyisocyanate is selected from aliphatic polyisocyanates, alicyclic polyisocyanates, aromatic polyisocyanates, or mixtures thereof, including but not limited to one or more of toluene diisocyanate, diphenylmethane diisocyanate, trimethylhexane diisocyanate, hexahydrotoluene diisocyanate, 1,4-cyclohexane diisocyanate, dodecyl diisocyanate, and dicyclohexylmethane diisocyanate, preferably one or more of HDI, IPDI, and HMDI.

[0021] In this invention, the molecular weight of the macromolecular polyol is 1000-2000, and it is preferably selected from one or more combinations of polyether polyols, such as PTMG, PPG, etc.

[0022] In this invention, the silanediol is selected from diphenylsilanediol.

[0023] In this invention, the hydrophilic chain extender is selected from one or more of dimethylolpropionic acid, dimethylolbutyric acid, diaminobenzoic acid, sodium dihydroxypropanesulfonate, amino acids, and aminosulfonates.

[0024] In this invention, the polyamine chain extender is an organic or inorganic primary or secondary amine functional compound containing at least two active hydrogen atoms, preferably including one or more of ethylenediamine, isophorone diamine, hexamethylenediamine, diethylenetriamine, phenylenediamine, toluenediamine, and dicyclohexylmethanediamine.

[0025] In this invention, the hard monomer containing a double bond is selected from one or more of methyl methacrylate, styrene, α-methylstyrene, α-methylstyrene, p-methylstyrene, or vinyltoluene;

[0026] In this invention, the soft monomer containing a double bond is selected from one or more of ethyl acrylate, n-butyl acrylate, 2-ethylheptaacrylate, isooctyl acrylate, isobutyl acrylate, cyclohexyl acrylate, 2-ethylhexyl acrylate, vinyl acetate, and vinyl propionate.

[0027] In this invention, the sulfonate containing a double bond is selected from one or more of sodium propenyl sulfonate and sodium methpropenyl sulfonate.

[0028] In this invention, the initiator initiation system is a redox system;

[0029] Preferably, the oxidant includes one or more of ammonium persulfate, sodium persulfate, potassium persulfate di-tert-butyl peroxide, hydrogen peroxide, cumene hydrogen peroxide, and tert-butyl hydrogen peroxide, with tert-butyl hydrogen peroxide being more preferred;

[0030] Preferably, the reducing agent includes one or more of ferrous sulfate, silver nitrate, thiols, ferrous chloride, sodium metabisulfite, sodium bisulfite, and isoascorbic acid, with sodium metabisulfite being more preferred.

[0031] In this invention, the method for synthesizing the modified polyurethane dispersion is as follows:

[0032] a. In a reaction vessel, add polyisocyanate, macromolecular polyol, silanediol, hydrophilic chain extender, catalyst, and solvent and mix them evenly. React at 50-80℃ until the theoretical NCO value is reached to obtain the prepolymer.

[0033] b. Cool the system to 50-60℃, add solvent and a portion of the modified monomer, stir and mix, and continue to cool to 27-35℃;

[0034] c. Add water to the cooled system for dispersion treatment;

[0035] d. After dispersion, add the polyamine chain extender to the system to obtain the modified waterborne polyurethane dispersion emulsion;

[0036] e. Add the remaining modified monomers to the modified waterborne polyurethane dispersion emulsion to allow swelling, add an initiator to carry out free radical polymerization, remove the solvent after polymerization to obtain the modified polyurethane dispersion.

[0037] Preferably, the mass of the modified monomer added in step b is 50-75% of the total mass of the modified monomer, more preferably 55-70%.

[0038] Preferably, the mixing time in step b is 2-10 min.

[0039] The modified polyurethane dispersion of the present invention has a solid content of 50-55%, a particle size of 120-150 nm, and exhibits obvious blue light.

[0040] According to the preparation method of the present invention, in some embodiments, the catalyst is selected from organobismuth catalysts, such as bismuth isooctanoate catalyst, bismuth laurylate catalyst, bismuth neodecanoate catalyst, and preferably organobismuth Coscat 83.

[0041] In this invention, the modified waterborne polyurethane dispersion prepared by the above method can be used in the clothing industry where high requirements are placed on moisture permeability, adhesion and washability.

[0042] The positive effects of this invention are mainly reflected in the following aspects:

[0043] The preparation of modified waterborne polyurethane compositions forms a core-shell structure, which is more conducive to the entanglement between the molecular chains of polyurethane emulsion and polyacrylate emulsion than blending of pure polyurethane emulsion and polyacrylate emulsion, thus improving polymerization stability and complementing each other's advantages. The introduction of sulfonate monomers, whose strong hydrophilicity can serve as water vapor permeation channels, enhances the moisture permeability of printing. The introduction of silicone glycol monomers can increase the bonding with silicone oil-treated fabric, thereby increasing the adhesion and washability of printing on silicone oil-treated fabric. Detailed Implementation

[0044] The testing method in this invention is as follows:

[0045] Moisture permeability test: The moisture permeability of the waterproof and breathable products of the examples and comparative examples was tested according to the ASTM E-96 1995BW standard test method.

[0046] Washability test: According to the AATCC 135-2004 (WO & W5) standard test method, the printed products prepared in each example and comparative example were washed with water and detergent at 40°C. After 5 washes, the moisture permeability and surface damage of the printed products were measured again using the aforementioned method.

[0047] The process for preparing printed products using dispersions is as follows: Following the formulation shown in the table below, the prepared waterborne polyurethane dispersion resin and additives are coated onto a silicone-treated fabric. The printing process involves manual screen printing, rotary screen printing, or two passes with four passes. The resulting sample is cured in a 50℃ oven for 24 hours, then further equilibrated in a constant temperature and humidity chamber (temperature: 25℃, humidity: 65% RH) for 48 hours before being tested.

[0048] The application formula for printed products is as follows:

[0049]

[0050]

[0051] The raw materials used in the examples are as follows:

[0052] (Dicyclohexylmethane diisocyanate, NCO% content approximately 32.0%, Wanhua Chemical Group Co., Ltd.);

[0053] (Isophorone diisocyanate, NCO% content approximately 37.8%, Wanhua Chemical Group Co., Ltd.);

[0054] PPG2000 (polypropylene glycol diol, hydroxyl value 56mgKOH / g, number-average molecular weight ≈2000, functionality 2, Dongda Chemistry);

[0055] PTMG2000 (polytetrahydrofuran ether diol, hydroxyl value 56mgKOH / g, number average molecular weight 2000, functionality 2, Yantai Huada Chemical);

[0056] PTMG1000 (polytetrahydrofuran ether diol, hydroxyl value 112 mgKOH / g, number average molecular weight 1000, functionality 2, Yantai Huada Chemical);

[0057] Diphenylsilanediol, Hubei Jiufenglong Chemical Co., Ltd.

[0058] Styrene, Wanhua Chemical Group Co., Ltd.;

[0059] Methyl methacrylate, Tianjin Kemeo Chemical Reagent Co., Ltd.;

[0060] n-Butyl acrylate, Wanhua Chemical Group Co., Ltd.

[0061] Ethyl acrylate, Tianjin Kemeo Chemical Reagent Co., Ltd.;

[0062] Isooctyl acrylate, Tianjin Kemeo Chemical Reagent Co., Ltd.;

[0063] Sodium metabisulfite (Xilong Chemical Co., Ltd.)

[0064] TBHP (tert-butyl hydroperoxide, Xilong Chemical Co., Ltd.)

[0065] Sodium propylene sulfonate, Shandong Yousuo Chemical Technology Co., Ltd.

[0066] Sodium methylpropene sulfonate, Hubei Qiniu Chemical Technology Co., Ltd.

[0067] Example 1

[0068] Add 32g IPDI, 58g PTMG2000, 3g diphenylsilanediol, 4g dimethylolpropionic acid, 0.3g organobismuth Coscat 83 and 40g acetone to a four-necked flask equipped with a reflux condenser, thermometer and mechanical stirrer and mix well. React at 80℃ until the theoretical NCO value is reached to obtain the prepolymer.

[0069] Cool the system to 60°C, add 100g acetone, 12.6g styrene monomer, 63g n-butyl acrylate monomer, and 8.4g sodium propylene sulfonate and stir for 5 minutes, then continue to cool to 30-35°C.

[0070] Add 186.2g of deionized water to the cooled system and disperse it under high-speed shear conditions;

[0071] 3g of ethylenediamine diluted with 40g of water was slowly added to the system to obtain a modified waterborne polyurethane dispersion emulsion.

[0072] A pre-emulsion consisting of 6.3g styrene monomer, 31.5g n-butyl acrylate monomer, and 4.2g sodium acrylate sulfonate was added to the system. The mixture was heated to 35℃ and stirred for 1 hour. Then, 0.063g tert-butyl hydroperoxide and 0.063g sodium metabisulfite were added sequentially to initiate free radical polymerization. After polymerization, the acetone in the emulsion was removed by vacuum distillation to obtain a modified waterborne polyurethane dispersion with a particle size of 120nm and obvious blue light.

[0073] Example 2

[0074] Add 39g HMDI, 45g PTMG1000, 6g diphenylsilanediol, 6g dimethylolbutyric acid, 0.3g organobismuth Coscat83 and 40g acetone to a four-necked flask equipped with a reflux condenser, thermometer and mechanical stirrer and mix well. React at 80℃ until the theoretical NCO value is reached to obtain the prepolymer.

[0075] Cool the system to 60°C, add 100g acetone, 26.88g methyl methacrylate monomer, 49.28g n-butyl acrylate monomer, and 13.44g sodium propylene sulfonate and stir for 5 minutes, then continue to cool to 30-35°C.

[0076] Add 152g of deionized water to the cooled system and disperse it under high-speed shear conditions.

[0077] 4g of isophorone diamine diluted with 40g of water was slowly added to the system to obtain a modified waterborne polyurethane dispersion emulsion.

[0078] A pre-emulsion consisting of 13.44 g methyl methacrylate monomer, 24.64 g n-butyl acrylate monomer, and 6.72 g sodium propylene sulfonate was added to the system. The mixture was heated to 35 °C and stirred for 1 h. Then, 0.135 g tert-butyl hydroperoxide and 0.135 g sodium metabisulfite were added sequentially to initiate free radical polymerization. After polymerization, the acetone in the emulsion was removed by vacuum distillation to obtain a modified waterborne polyurethane dispersion with a particle size of 132 nm and obvious blue light.

[0079] Example 3

[0080] 11g IPDI, 33g HMDI, 48g PTMG 1000, 1g diphenylsilanediol, 4g dimethylolpropionic acid, 0.3g organobismuth Coscat 83, and 40g acetone were added to a four-necked flask equipped with a reflux condenser, thermometer, and mechanical stirrer and mixed thoroughly. The mixture was then reacted at 80°C until the theoretical NCO value was reached to obtain the prepolymer.

[0081] Cool the system to 60°C, add 100g acetone, 19.2g methyl methacrylate monomer, 56.7g isooctyl acrylate monomer, and 11.3g sodium methacrylate sulfonate, and stir for 5 minutes. Then continue to cool to 30-35°C.

[0082] 173.4g of deionized water was added to the cooled system and dispersed under high-speed shear conditions.

[0083] 3g of ethylenediamine diluted with 40g of water was slowly added to the system to obtain a modified waterborne polyurethane dispersion emulsion.

[0084] A pre-emulsion consisting of 9.6 g methyl methacrylate monomer, 28 g isooctyl acrylate monomer, and 5.7 g sodium methpropylene sulfonate was added to the system. The mixture was heated to 35 °C and stirred for 1 h. Then, 0.098 g tert-butyl hydroperoxide and 0.098 g sodium metabisulfite were added sequentially to initiate free radical polymerization. After polymerization, the acetone in the emulsion was removed by vacuum distillation to obtain a modified waterborne polyurethane dispersion with a particle size of 148 nm and obvious blue light.

[0085] Example 4

[0086] 23g HMDI, 12g HDI, 51g PTMG 1000, 3g diphenylsilanediol, 5g dimethylolbutyric acid, 0.3g organobismuth Coscat 83, and 40g acetone were added to a four-necked flask equipped with a reflux condenser, thermometer, and mechanical stirrer and mixed thoroughly. The mixture was reacted at 80°C until the theoretical NCO value was reached to obtain the prepolymer.

[0087] Cool the system to 60°C, add 100g acetone, 26.32g styrene monomer, 55.3g n-butyl acrylate monomer, and 6.13g sodium methacrylate sulfonate monomer, stir and mix for 5 minutes, and continue to cool to 30-35°C.

[0088] Add 191.7g of deionized water to the cooled system and disperse it under high-speed shear conditions;

[0089] 6g of isophorone diamine diluted with 40g of water was slowly added to the system to obtain a modified waterborne polyurethane dispersion emulsion.

[0090] A pre-emulsion consisting of 13.16 g styrene monomer, 27.6 g n-butyl acrylate monomer, and 3 g sodium methpropylene sulfonate monomer was added to the system. The mixture was heated to 35 °C and stirred for 1 h. Then, 0.07 g tert-butyl hydroperoxide and 0.07 g sodium metabisulfite were added sequentially to initiate free radical polymerization. After polymerization, the acetone in the emulsion was removed by vacuum distillation to obtain a modified waterborne polyurethane dispersion with a particle size of 120 nm and obvious blue light.

[0091] Example 5

[0092] Add 10g HDI, 25g IPDI, 51g PTMG 1000, 3g diphenylsilanediol, 5g dimethylolbutyric acid, 0.3g organobismuth Coscat 83, and 40g acetone to a four-necked flask equipped with a reflux condenser, thermometer, and mechanical stirrer, and mix well. React at 80°C until the theoretical NCO value is reached to obtain the prepolymer.

[0093] Cool the system to 60°C, add 100g acetone, 19.6g styrene monomer, 51.1g n-butyl acrylate monomer, and 14.5g sodium propylene sulfonate, and stir for 5 minutes. Then continue to cool to 30-35°C.

[0094] Add 188g of deionized water to the cooled system and disperse it under high-speed shear conditions.

[0095] 6g of isophorone diamine diluted with 40g of water was slowly added to the system to obtain a modified waterborne polyurethane dispersion emulsion.

[0096] A pre-emulsion consisting of 9.8g styrene monomer, 25.6g n-butyl acrylate monomer, and 7.2g sodium propylene sulfonate was added to the system. The mixture was heated to 35℃ and stirred for 1 hour. Then, 0.096g tert-butyl hydroperoxide and 0.096g sodium metabisulfite were added sequentially to initiate free radical polymerization. After polymerization, the acetone in the emulsion was removed by vacuum distillation to obtain a modified waterborne polyurethane dispersion with a particle size of 125nm and obvious blue light.

[0097] Comparative Example 1

[0098] 11g IPDI, 33g HMDI, 48g PTMG 1000, 5g dimethylolpropionic acid, 0.3g organic bismuth Coscat 83 and 40g acetone were added to a four-necked flask equipped with a reflux condenser, thermometer and mechanical stirrer and mixed evenly. The mixture was reacted at 80℃ until the theoretical NCO value was reached to obtain the prepolymer.

[0099] Cool the system to 60°C, add 100g acetone, 19.2g methyl methacrylate monomer, 56.7g isooctyl acrylate monomer, and 11.3g sodium methacrylate sulfonate, and stir for 5 minutes. Then continue to cool to 30-35°C.

[0100] 173.4g of deionized water was added to the cooled system and dispersed under high-speed shear conditions.

[0101] 3g of ethylenediamine diluted with 40g of water was slowly added to the system to obtain a modified waterborne polyurethane dispersion emulsion.

[0102] A pre-emulsion consisting of 9.6 g methyl methacrylate monomer, 28 g isooctyl acrylate monomer, and 5.7 g sodium methpropylene sulfonate was added to the system. The mixture was heated to 35 °C and stirred for 1 h. Then, 0.098 g tert-butyl hydroperoxide and 0.098 g sodium metabisulfite were added sequentially to initiate free radical polymerization. After polymerization, the acetone in the emulsion was removed by vacuum distillation to obtain a modified waterborne polyurethane dispersion with a particle size of 150 nm and obvious blue light.

[0103] Comparative Example 2

[0104] 23g HMDI, 12g HDI, 51g PTMG 1000, 3g diphenylsilanediol, 5g dimethylolbutyric acid, 0.3g organobismuth Coscat 83, and 40g acetone were added to a four-necked flask equipped with a reflux condenser, thermometer, and mechanical stirrer and mixed thoroughly. The mixture was reacted at 80°C until the theoretical NCO value was reached to obtain the prepolymer.

[0105] Cool the system to 60°C, add 100g acetone, 26.32g styrene monomer, and 61.4g n-butyl acrylate monomer, stir and mix for 5 minutes, and continue to cool to 30-35°C.

[0106] Add 165g of deionized water to the cooled system and disperse it under high-speed shear conditions.

[0107] 6g of isophorone diamine diluted with 40g of water was slowly added to the system to obtain a modified waterborne polyurethane dispersion emulsion.

[0108] A pre-emulsion consisting of 13.16g styrene monomer and 30.7g n-butyl acrylate monomer was added to the system. The mixture was heated to 35℃ and stirred for 1 hour. Then, 0.07g tert-butyl hydrogen peroxide and 0.07g sodium metabisulfite were added sequentially to initiate free radical polymerization. After polymerization, the acetone in the emulsion was removed by vacuum distillation to obtain a modified waterborne polyurethane dispersion with a particle size of 134nm and obvious blue light.

[0109] Comparative Example 3

[0110] 11g IPDI, 33g HMDI, 48g PTMG 1000, 5g dimethylolpropionic acid, 0.3g organic bismuth Coscat 83 and 40g acetone were added to a four-necked flask equipped with a reflux condenser, thermometer and mechanical stirrer and mixed evenly. The mixture was reacted at 80℃ until the theoretical NCO value was reached to obtain the prepolymer.

[0111] Cool the system to 60°C, add 100g acetone, 26.32g methyl methacrylate monomer, and 61.4g isooctyl acrylate monomer, stir and mix for 5 minutes, and continue to cool to 30-35°C.

[0112] Add 182.7g of deionized water to the cooled system and disperse it under high-speed shear conditions;

[0113] 3g of ethylenediamine diluted with 40g of water was slowly added to the system to obtain a modified waterborne polyurethane dispersion emulsion.

[0114] A pre-emulsion consisting of 13.16 g of methyl methacrylate monomer and 30.7 g of isooctyl acrylate monomer was added to the system. The mixture was heated to 35 °C and stirred for 1 h. Then, 0.098 g of tert-butyl hydroperoxide and 0.098 g of sodium metabisulfite were added sequentially to initiate free radical polymerization. After polymerization, the acetone in the emulsion was removed by vacuum distillation to obtain a modified waterborne polyurethane dispersion with a particle size of 146 nm and obvious blue light.

[0115] Modified waterborne polyurethane compositions were prepared using the compositions obtained in the various examples and comparative examples according to the printing formulations listed in the specific embodiments, and performance tests were conducted. The results of the printing performance tests are shown in the table below:

[0116]

[0117] As can be seen from the table above, the modified polyurethane composition prepared by this invention achieves good results in terms of moisture permeability and water resistance during printing.

Claims

1. A modified polyurethane dispersion comprising the following raw materials in weight percentages: Component 1) Polyisocyanate 30-50 wt%; Component 2) 40-60 wt% macromolecular polyols; Component 3) Silicon diol 1-6 wt%; Component 4) Hydrophilic chain extender 4-6 wt%; Assuming the sum of the total mass of components 1)-4) is 100%; The raw materials also include: component 6) modified monomer, the amount of which is 125-140% of the total mass of components 1)-4); the modified monomer includes hard monomers containing double bonds, soft monomers containing double bonds, and sulfonate monomers containing double bonds; the amount of hard monomers containing double bonds is 15-30 wt% of the mass of the modified monomers; the amount of soft monomers containing double bonds is 55-75 wt% of the mass of the modified monomers; and the amount of sulfonate monomers containing double bonds is 7-17 wt% of the mass of the modified monomers.

2. The modified polyurethane dispersion according to claim 1, characterized in that, The raw materials also include: component 5) a polyamine chain extender, the amount of which is 3-6 wt% of the total mass of components 1)-4).

3. The modified polyurethane dispersion according to claim 2, characterized in that, Polyamine chain extenders are organic primary or secondary amine functional compounds containing at least two active hydrogen atoms.

4. The modified polyurethane dispersion according to claim 3, characterized in that, Polyamine chain extenders include one or more of ethylenediamine, isophorone diamine, hexamethylenediamine, diethylenetriamine, phenylenediamine, toluenediamine, and dicyclohexylmethanediamine.

5. The modified polyurethane dispersion according to claim 1, characterized in that, The weight percentage of component 1) polyisocyanate is 32-44 wt%; the weight percentage of component 2) macromolecular polyol is 45-58 wt%.

6. The modified polyurethane dispersion according to claim 1, characterized in that, The raw materials also include: component 7) initiator, the amount of which is 0.05-0.3% of the total mass of the modified monomer.

7. The modified polyurethane dispersion according to claim 6, characterized in that, The amount of the initiator is 0.1-0.2% of the total mass of the modified monomer.

8. The modified polyurethane dispersion according to claim 1, characterized in that, The raw materials also include: component 8) catalyst, in an amount of 0.01%-1% of the total mass of components 1)-4).

9. The modified polyurethane dispersion according to claim 1, characterized in that, Polyisocyanates are selected from aliphatic polyisocyanates, alicyclic polyisocyanates, aromatic polyisocyanates, or mixtures thereof.

10. The modified polyurethane dispersion according to claim 9, characterized in that, The polyisocyanate is selected from one or more of toluene diisocyanate, diphenylmethane diisocyanate, trimethylhexane diisocyanate, hexahydrotoluene diisocyanate, 1,4-cyclohexane diisocyanate, dodecyl diisocyanate and dicyclohexylmethane diisocyanate.

11. The modified polyurethane dispersion according to claim 9, characterized in that, The polyisocyanate is selected from one or more of HDI, IPDI, and HMDI.

12. The modified polyurethane dispersion according to claim 1, characterized in that, The molecular weight of macromolecular polyols is 1000-2000.

13. The modified polyurethane dispersion according to claim 1, characterized in that, The macromolecular polyol is a polyether polyol.

14. The modified polyurethane dispersion according to claim 1, characterized in that, The silanediol is selected from diphenylsilanediol.

15. The modified polyurethane dispersion according to claim 1, characterized in that, The hydrophilic chain extender is selected from one or more of dimethylolpropionic acid, dimethylolbutyric acid, diaminobenzoic acid, sodium dihydroxypropanesulfonate, amino acids, and aminosulfonates.

16. The modified polyurethane dispersion according to claim 1, characterized in that, The hard monomer containing a double bond is selected from one or more of methyl methacrylate, styrene, α-methylstyrene, p-methylstyrene, or vinyltoluene.

17. The modified polyurethane dispersion according to claim 1, characterized in that, The soft monomer containing a double bond is selected from one or more of ethyl acrylate, n-butyl acrylate, 2-ethylheptaacrylate, isooctyl acrylate, isobutyl acrylate, cyclohexyl acrylate, vinyl acetate, and vinyl propionate.

18. The modified polyurethane dispersion according to claim 1, characterized in that, Sulfonates containing double bonds are selected from one or more of sodium propenyl sulfonate and sodium methpropenyl sulfonate.

19. The modified polyurethane dispersion according to claim 8, characterized in that, The catalyst is selected from organic bismuth catalysts.

20. The modified polyurethane dispersion according to claim 6, characterized in that, The initiation system of the initiator is a redox system.

21. The modified polyurethane dispersion according to claim 20, characterized in that, The oxidizing agent in the redox system includes one or more of ammonium persulfate, sodium persulfate, potassium persulfate, di-tert-butyl peroxide, hydrogen peroxide, cumene hydrogen peroxide, and tert-butyl hydrogen peroxide.

22. The modified polyurethane dispersion according to claim 20, characterized in that, The reducing agent in the redox system includes one or more of ferrous sulfate, thiols, ferrous chloride, sodium metabisulfite, sodium bisulfite, and isoascorbic acid.

23. The method for preparing the modified polyurethane dispersion according to any one of claims 1-22, characterized in that, Includes the following steps: a. In a reaction vessel, add polyisocyanate, macromolecular polyol, silanediol, hydrophilic chain extender, catalyst, and solvent and mix them evenly. React at 50-80℃ until the theoretical NCO value is reached to obtain the prepolymer. b. Cool the system to 50-60℃, add solvent and a portion of the modified monomer, stir and mix, and continue to cool to 27-35℃; c. Add water to the cooled system for dispersion treatment; d. After dispersion, add the polyamine chain extender to the system to obtain the modified waterborne polyurethane dispersion emulsion; e. Add the remaining modified monomers to the modified waterborne polyurethane dispersion emulsion to allow swelling, add an initiator to carry out free radical polymerization, remove the solvent after polymerization to obtain the modified polyurethane dispersion.

24. The method for preparing the modified polyurethane dispersion according to claim 23, characterized in that, In step b, the mass of the modified monomer added first is 50-75% of the total mass of the modified monomer.

25. The method for preparing the modified polyurethane dispersion according to claim 24, characterized in that, In step b, the mass of the modified monomer added first is 55-70% of the total mass of the modified monomer.

26. The method for preparing the modified polyurethane dispersion according to claim 23, characterized in that, The mixing time in step b is 2-10 minutes.

27. The application of a modified polyurethane dispersion according to any one of claims 1-22 or a modified polyurethane dispersion prepared by the preparation method according to any one of claims 23-26, characterized in that, Used in the apparel industry.

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