Preparation method of polyurethane acrylic resin finishing agent for improving fabric stiffness

Abstract

The present invention relates to the technical field of finishing agents and discloses a method for preparing a polyurethane acrylic resin finishing agent for improving fabric stiffness. The method comprises reacting polyether polyol, isophorone diisocyanate, sodium hydroxysulfonate styrene monomer, etc. to obtain a polyurethane acrylic ester. The polyurethane acrylic ester is then polymerized with an acrylate monomer, sodium hydroxysulfonate styrene monomer, azobisisobutyronitrile, etc. to obtain a polyurethane acrylic resin finishing agent. The sodium hydroxysulfonate styrene monomer of the present invention serves as both an end-capping agent and a hardening monomer. The polyurethane acrylic resin finishing agent prepared by the polyurethane acrylic resin finishing agent significantly improves the stiffness of cotton fabric and its resistance to bending deformation. Furthermore, the finished cotton fabric maintains a low water droplet diffusion time, exhibiting excellent hydrophilicity.

Description

Technical Field

[0001] The invention relates to the technical field of finishing agents, in particular to a method for preparing a polyurethane acrylic resin finishing agent for improving the stiffness of fabrics. Background Art

[0002] Stiffeners are common fabric finishing agents that improve fabric properties such as resistance to bending deformation, a sense of heaviness, and a stiff feel. They are widely used in textiles such as cotton and polyester. Traditional stiffeners include melamine resins, urea-formaldehyde resins, and acrylic resins. Polyurethane acrylic resins offer excellent elasticity, softness, weather resistance, and mechanical strength, making them a promising fabric finishing agent.

[0003] By regulating the polymerization monomers, a polyurethane acrylic resin finishing agent can improve fabrics' waterproof and oil-proofing, wrinkle resistance, and antibacterial properties. Patent publication number CN110607690B discloses a polyacrylate-polyurethane composite emulsion with UV resistance, its preparation method, and its application. The composite emulsion, obtained by mixing a water-soluble polyacrylate emulsion containing sodium lignin sulfonate with an aqueous polyurethane emulsion, can improve cotton fabrics' UV resistance and other properties. However, the composite emulsion in this patent does not increase cotton fabric stiffness. Summary of the Invention

[0004] Technical problem solved: Solved the problem that polyurethane finishing agents are difficult to effectively improve the stiffness and other properties of cotton fabrics and other textiles.

[0005] Technical solution: Preparation method of polyurethane acrylic resin finishing agent for improving fabric stiffness:

[0006] (1) Add dry polyether polyol and isophorone diisocyanate to a reaction flask, introduce nitrogen, and carry out prepolymerization at 65-80°C for 2-3 hours to generate an isocyanate-terminated polyurethane prepolymer; then add acetone, sodium hydroxysulfonate styrene monomer, and dibutyltin dilaurate, and carry out a capping reaction for 40-60 minutes. Remove the acetone by vacuum distillation to obtain polyurethane acrylate.

[0007] (2) Deionized water, emulsifier, polyurethane acrylate, acrylate monomer, and sodium hydroxysulfonate styrene monomer are added to the reaction bottle, nitrogen is introduced after shear dispersion, azobisisobutyronitrile is added, and polymerization reaction is carried out at 70-80°C for 6-8h, deionized water is added to dilute, and shear dispersion is carried out to obtain a polyurethane acrylic resin finishing agent that improves the stiffness of the fabric.

[0008] Preferably, in step (1), the molar ratio of polyether polyol, isophorone diisocyanate, sodium hydroxysulfonate styrene monomer, and dibutyltin dilaurate is 1:(2.6-2.8):(1.3-1.4):(0.014-0.018).

[0009] Preferably, the polyether polyol is polyethylene glycol or polypropylene glycol.

[0010] Preferably, in step (2), the mass ratio of polyurethane acrylate, emulsifier, acrylate monomer, sodium hydroxysulfonate styrene monomer, and azobisisobutyronitrile is 100:(7-10):(300-450):(80-140):(8-12).

[0011] Preferably, the acrylate monomer is any one or a combination of methyl acrylate, methyl methacrylate, butyl acrylate, and butyl methacrylate.

[0012] Preferably, the emulsifier is sodium dodecylbenzenesulfonate or sodium dodecyl sulfate.

[0013] Preferably, the preparation method of sodium hydroxysulfonate styrene monomer is as follows: ethanol, deionized water, sodium 3-chloro-2-hydroxypropanesulfonate, and sodium p-vinylbenzoate (CAS registration number 77124-40-4) in a molar ratio of (1-1.2):1 are added to a reaction flask, stirred at 60-75°C for 6-10 hours, and after vacuum distillation, the product is added to deionized water, heated for volatilization, and cooled for crystallization to obtain sodium hydroxysulfonate styrene monomer. The reaction formula is:

[0014] .

[0015] The beneficial technical effect of the present invention is that the chlorine atom of sodium 3-chloro-2-hydroxypropanesulfonate reacts with the sodium carboxylate group of sodium p-vinylbenzoate to obtain a sodium hydroxysulfonate styrene monomer, which contains a hydroxyl group and can be used as a capping agent to react with the terminal isocyanate of the polyurethane prepolymer, thereby introducing a sodium sulfonate group and a polymerizable alkenyl group into the polyurethane molecular chain to obtain a polyurethane acrylate.

[0016] The sodium hydroxysulfonate styrene monomer of the present invention not only functions as an end-capping agent but also contains a styrene structure, making it suitable as a hard monomer to replace conventional styrene. The monomer can be polymerized with methyl methacrylate, butyl acrylate, and other polyurethane acrylates to produce a polyurethane acrylic resin finishing agent. This finishing agent significantly improves the stiffness and resistance to bending deformation of cotton fabrics. Furthermore, the polyurethane acrylic resin finishing agent contains a large number of hydroxyl and sodium sulfonate groups, which interact strongly with the cotton fabric, such as by hydrogen bonding. This allows the finishing agent to adhere tightly and securely to the fabric surface, making it difficult to wash off. Even after multiple washes, the cotton fabric retains its high stiffness and resistance to bending deformation.

[0017] The molecular chain of the polyurethane acrylic resin finishing agent of the present invention contains a large number of hydrophilic hydroxyl groups and sodium sulfonate groups. The cotton fabric after finishing still maintains a low water droplet diffusion time and has good hydrophilicity. DETAILED DESCRIPTION

[0018] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below through examples. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0019] Example 1

[0020] (1) Add 80 mL of ethanol, 30 mL of deionized water, 60 mmol of sodium 3-chloro-2-hydroxypropanesulfonate, and 60 mmol of sodium p-vinylbenzoate to a reaction flask, stir and react at 75°C for 6 h, and add the product to deionized water after vacuum distillation. Heat to evaporate, cool and crystallize to obtain sodium hydroxysulfonate styrene monomer.

[0021] (2) Add 20 mmol of dry polyethylene glycol 1000 and 54 mmol of isophorone diisocyanate to the reaction flask, introduce nitrogen, and carry out prepolymerization at 70°C for 3 hours to generate an isocyanate-terminated polyurethane prepolymer; then add 10 mL of acetone, 27 mmol of sodium hydroxysulfonate styrene monomer, and 0.33 mmol of dibutyltin dilaurate, and carry out a capping reaction for 40 minutes. Remove the acetone by vacuum distillation to obtain polyurethane acrylate.

[0022] (3) Add 160 mL of deionized water, 0.8 g of emulsifier sodium dodecylbenzenesulfonate, 10 g of polyurethane acrylate, 25 g of methyl methacrylate, 13 g of butyl acrylate, and 8 g of sodium hydroxysulfonate styrene monomer to the reaction bottle, introduce nitrogen after shear dispersion, add 1 g of azobisisobutyronitrile, and carry out polymerization reaction at 80 ° C for 6 h. Add 960 mL of deionized water to dilute, shear dispersion, and obtain a polyurethane acrylic resin finishing agent that improves the stiffness of the fabric.

[0023] Example 2

[0024] (1) Add 80 mL of ethanol, 40 mL of deionized water, 72 mmol of sodium 3-chloro-2-hydroxypropanesulfonate, and 60 mmol of sodium p-vinylbenzoate to a reaction flask, stir and react at 60°C for 10 h, and add the product to deionized water after vacuum distillation. Heat to evaporate, cool and crystallize to obtain sodium hydroxysulfonate styrene monomer.

[0025] (2) Add 20 mmol of dry polypropylene glycol 1000 and 56 mmol of isophorone diisocyanate to the reaction flask, introduce nitrogen, and carry out prepolymerization at 75°C for 3 hours to generate an isocyanate-terminated polyurethane prepolymer; then add 15 mL of acetone, 28 mmol of sodium hydroxysulfonate styrene monomer, and 0.36 mmol of dibutyltin dilaurate, and carry out a capping reaction for 60 minutes. Remove the acetone by vacuum distillation to obtain polyurethane acrylate.

[0026] (3) Add 150 mL of deionized water, 0.7 g of emulsifier sodium lauryl sulfate, 10 g of polyurethane acrylate, 19 g of methyl acrylate, 11 g of butyl methacrylate, and 10 g of sodium hydroxysulfonate styrene monomer to the reaction bottle, introduce nitrogen after shear dispersion, add 0.8 g of azobisisobutyronitrile, carry out polymerization reaction at 75 ° C for 8 h, add 520 mL of deionized water to dilute, shear dispersion, and obtain a polyurethane acrylic resin finishing agent for improving the stiffness of the fabric.

[0027] Example 3

[0028] (1) Prepare sodium hydroxysulfonate styrene monomer according to the method of Example 1.

[0029] (2) Add 20 mmol of dry polyethylene glycol 1000 and 52 mmol of isophorone diisocyanate to the reaction flask, introduce nitrogen, and carry out prepolymerization at 80°C for 2 hours to generate an isocyanate-terminated polyurethane prepolymer; then add 10 mL of acetone, 26 mmol of sodium hydroxysulfonate styrene monomer, and 0.28 mmol of dibutyltin dilaurate, and carry out a capping reaction for 60 minutes. Remove the acetone by vacuum distillation to obtain polyurethane acrylate.

[0030] (3) Add 180 mL of deionized water, 1 g of emulsifier sodium lauryl sulfate, 10 g of polyurethane acrylate, 28 g of methyl methacrylate, 17 g of butyl acrylate, and 12 g of sodium hydroxysulfonate styrene monomer to the reaction bottle, introduce nitrogen after shear dispersion, add 1.1 g of azobisisobutyronitrile, and carry out polymerization reaction at 75 ° C for 8 h. Add 490 mL of deionized water to dilute, shear dispersion, and obtain a polyurethane acrylic resin finishing agent that improves the stiffness of the fabric.

[0031] Example 4

[0032] (1) Prepare sodium hydroxysulfonate styrene monomer according to the method of Example 1.

[0033] (2) Add 20 mmol of dry polyethylene glycol 1000 and 56 mmol of isophorone diisocyanate to the reaction flask, introduce nitrogen, and carry out prepolymerization at 65°C for 3 hours to generate an isocyanate-terminated polyurethane prepolymer; then add 15 mL of acetone, 28 mmol of sodium hydroxysulfonate styrene monomer, and 0.36 mmol of dibutyltin dilaurate, and carry out a capping reaction for 60 minutes. Remove the acetone by vacuum distillation to obtain polyurethane acrylate.

[0034] (3) Add 170 mL of deionized water, 1 g of emulsifier sodium dodecylbenzenesulfonate, 10 g of polyurethane acrylate, 26 g of methyl methacrylate, 14 g of butyl acrylate, and 14 g of sodium hydroxysulfonate styrene monomer to the reaction flask. After shear dispersion, introduce nitrogen. Add 1.2 g of azobisisobutyronitrile and carry out polymerization reaction at 70 ° C for 8 h. Add 360 mL of deionized water to dilute and shear dispersion to obtain a polyurethane acrylic resin finishing agent for improving the stiffness of the fabric.

[0035] Comparative Example 1

[0036] (1) Add 20 mmol of dry polyethylene glycol 1000 and 54 mmol of isophorone diisocyanate to a reaction flask, introduce nitrogen, and carry out prepolymerization at 70°C for 3 h to generate an isocyanate-terminated polyurethane prepolymer; then add 10 mL of acetone, 27 mmol of hydroxyethyl acrylate, and 0.33 mmol of dibutyltin dilaurate, and carry out a capping reaction for 40 min. Remove the acetone by vacuum distillation to obtain polyurethane acrylate.

[0037] (2) Add 160 mL of deionized water, 0.8 g of emulsifier sodium dodecylbenzenesulfonate, 10 g of polyurethane acrylate, 25 g of methyl methacrylate, 13 g of butyl acrylate, and 8 g of styrene to the reaction flask. After shear dispersion, introduce nitrogen. Add 1 g of azobisisobutyronitrile and carry out polymerization reaction at 80 ° C for 6 h. Add 960 mL of deionized water to dilute and shear dispersion to obtain a polyurethane acrylic resin finishing agent that improves the stiffness of the fabric.

[0038] Comparative Example 2

[0039] (1) Prepare sodium hydroxysulfonate styrene monomer according to the method of Example 1.

[0040] (2) Add 20 mmol of dry polyethylene glycol 1000 and 54 mmol of isophorone diisocyanate to the reaction flask, introduce nitrogen, and carry out prepolymerization at 70°C for 3 hours to generate an isocyanate-terminated polyurethane prepolymer; then add 10 mL of acetone, 27 mmol of sodium hydroxysulfonate styrene monomer, and 0.33 mmol of dibutyltin dilaurate, and carry out a capping reaction for 40 minutes. Remove the acetone by vacuum distillation to obtain polyurethane acrylate.

[0041] (3) Add 160 mL of deionized water, 0.8 g of emulsifier sodium dodecylbenzenesulfonate, 10 g of polyurethane acrylate, 25 g of methyl methacrylate, 13 g of butyl acrylate, and 8 g of styrene to the reaction flask. After shear dispersion, introduce nitrogen. Add 1 g of azobisisobutyronitrile and carry out polymerization reaction at 80 °C for 6 h. Add 960 mL of deionized water to dilute and shear dispersion to obtain a polyurethane acrylic resin finishing agent for improving the stiffness of the fabric.

[0042] Comparative Example 3

[0043] (1) Prepare sodium hydroxysulfonate styrene monomer according to the method of Example 1.

[0044] (2) Add 20 mmol of dry polyethylene glycol 1000 and 54 mmol of isophorone diisocyanate to the reaction flask, introduce nitrogen, and carry out prepolymerization at 70°C for 3 hours to generate an isocyanate-terminated polyurethane prepolymer; then add 10 mL of acetone, 27 mmol of hydroxyethyl acrylate, and 0.33 mmol of dibutyltin dilaurate, and carry out a capping reaction for 40 minutes. Remove the acetone by vacuum distillation to obtain polyurethane acrylate.

[0045] (3) Add 160 mL of deionized water, 0.8 g of emulsifier sodium dodecylbenzenesulfonate, 10 g of polyurethane acrylate, 25 g of methyl methacrylate, 13 g of butyl acrylate, and 8 g of sodium hydroxysulfonate styrene monomer to the reaction bottle, introduce nitrogen after shear dispersion, add 1 g of azobisisobutyronitrile, and carry out polymerization reaction at 80 ° C for 6 h. Add 960 mL of deionized water to dilute, shear dispersion, and obtain a polyurethane acrylic resin finishing agent that improves the stiffness of the fabric.

[0046] Comparative Example 4

[0047] (1) Prepare sodium hydroxysulfonate styrene monomer according to the method of Example 1.

[0048] (2) Add 20 mmol of dry polyethylene glycol 1000 and 54 mmol of isophorone diisocyanate to the reaction flask, introduce nitrogen, and carry out prepolymerization at 70°C for 3 hours to generate an isocyanate-terminated polyurethane prepolymer; then add 10 mL of acetone, 27 mmol of sodium hydroxysulfonate styrene monomer, and 0.33 mmol of dibutyltin dilaurate, and carry out a capping reaction for 40 minutes. Remove the acetone by vacuum distillation to obtain polyurethane acrylate.

[0049] (3) Add 160 mL of deionized water, 0.8 g of emulsifier sodium dodecylbenzenesulfonate, 10 g of polyurethane acrylate, 25 g of methyl methacrylate, 13 g of butyl acrylate, and 8 g of sodium 4-styrenesulfonate to the reaction flask. After shear dispersion, introduce nitrogen. Add 1 g of azobisisobutyronitrile and carry out polymerization reaction at 80 °C for 6 h. Add 960 mL of deionized water to dilute and shear dispersion to obtain a polyurethane acrylic resin finishing agent for improving the stiffness of the fabric.

[0050] Finishing agent performance test: Cotton fabric was added to the finishing agent with a bath ratio of 1:20, and double-immersion and double-pad finishing was performed with a padding rate of 90%. The cotton fabric was then pre-dried at 80°C for 4 minutes, baked at 160°C for 3 minutes, washed with water, and air-dried to obtain the finished cotton fabric.

[0051] The cotton fabric that has not been treated with the finishing agent was used as the blank control sample.

[0052] The cotton fabric was cut into samples of 20 cm × 2.5 cm and the stiffness A was tested using a stiffness tester. Each group of samples was tested 3 times and the average value was taken.

[0053] Wash cotton fabric 30 times according to GB / T 8629-2017, then test stiffness A1. Calculate stiffness retention: (A1 / A) × 100%.

[0054] Table 1 Stiffness performance test

[0055]

[0056] Testing showed that, compared to a blank cotton fabric control, the cotton fabrics treated with the polyurethane acrylic resin finishes in Examples 1-4 exhibited stiffness ranging from 75.8 to 121.5 mm, demonstrating excellent resistance to bending deformation. Furthermore, the stiffness remained high, with minimal degradation, even after multiple washes. This is primarily due to the use of sodium hydroxysulfonate styrene monomer as both an end-capping agent and a polymerizing monomer, which introduces a large number of hydroxyl and sodium sulfonate groups into the molecular chain of the polyurethane acrylic resin. This creates strong hydrogen bonding interactions with the cotton fabric, allowing the finish to adhere tightly and securely to the surface, making it difficult to wash off and resulting in a high stiffness retention rate.

[0057] Compared to Example 1, the polyurethane acrylic resin finishes of Comparative Examples 1-4 also significantly increased the stiffness of cotton fabrics after finishing them. However, after multiple washes, the stiffness decreased to varying degrees, resulting in a low stiffness retention rate. The main reason for the difference in Comparative Example 1 is that the finish prepared using hydroxyethyl acrylate as the end-capping agent and styrene as the polymerization monomer lacks hydroxyl and sodium sulfonate groups, resulting in low interaction between the finish and the cotton fabric. This results in the finish not being firmly adhered to the fabric surface, making it easily eluted, resulting in a significant decrease in stiffness. Comparative Example 2, using sodium hydroxysulfonate styrene monomer as the end-capping agent and styrene as the polymerization monomer, has few hydroxyl and sodium sulfonate groups. This results in low interaction between the finish and the cotton fabric, making it easily eluted and resulting in a significant decrease in stiffness. Comparative Example 3, using hydroxyethyl acrylate (which does not contain sodium sulfonate groups) as the end-capping agent and sodium hydroxysulfonate styrene monomer as the polymerization monomer, results in a polyurethane acrylic resin with slightly fewer sodium sulfonate groups than in Example 1, resulting in a slightly lower stiffness retention rate than in Example 1. In Comparative Example 4, sodium 4-styrenesulfonate (containing no hydroxyl group) was used as the polymerization monomer. The obtained polyurethane acrylic resin had very few hydroxyl groups, and had low interaction with the cotton fabric. The finishing agent was easily washed off, and the stiffness decreased significantly.

[0058] The hydrophilicity and water droplet spreading time of cotton fabrics were tested according to AATCC 79-2010 method. The test was repeated 5 times and the average value was taken. The shorter the water droplet spreading time, the better the hydrophilicity.

[0059] Table 2 Hydrophilicity test

[0060]

[0061] After testing, Examples 1 to 4 used polyurethane acrylic resin finishing agents to finish cotton fabrics. The molecular chains of the finishing agents contained a large number of hydrophilic hydroxyl groups and sodium sulfonate groups, which enabled the cotton fabrics to still maintain a low water droplet diffusion time and have good hydrophilicity.

[0062] Compared to Example 1, the polyurethane acrylic resin finish in Comparative Example 1 lacked hydrophilic hydroxyl and sodium sulfonate groups, resulting in poor hydrophilicity and a long water droplet diffusion time for the cotton fabric after finishing. The polyurethane acrylic resin finish in Comparative Example 2 contained fewer hydroxyl and sodium sulfonate groups, leading to poor hydrophilicity and a long water droplet diffusion time for the cotton fabric after finishing. The polyurethane acrylic resin in Comparative Example 4 contained fewer hydroxyl groups and exhibited lower hydrophilicity than Example 1, resulting in a long water droplet diffusion time and poor hydrophilicity.

[0063] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for preparing a polyurethane acrylic resin finishing agent for improving fabric stiffness, characterized in that: The preparation method comprises the following steps: (1) Add dry polyether polyol and isophorone diisocyanate to a reaction flask, introduce nitrogen to carry out a prepolymerization reaction, then add acetone, sodium hydroxysulfonate styrene monomer, and dibutyltin dilaurate to carry out a capping reaction, and remove acetone by vacuum distillation to obtain polyurethane acrylate; (2) adding deionized water, an emulsifier, the polyurethane acrylate prepared in step (1), an acrylate monomer, and a sodium hydroxysulfonate styrene monomer to a reaction flask, introducing nitrogen after shearing and dispersing, adding azobisisobutyronitrile, carrying out a polymerization reaction, adding deionized water to dilute, and shearing and dispersing to obtain a polyurethane acrylic resin finishing agent for improving the stiffness of the fabric; The structural formula of the sodium hydroxysulfonate styrene monomer is .

2. The method for preparing the polyurethane acrylic resin finishing agent for improving fabric stiffness according to claim 1, characterized in that: The molar ratio of the polyether polyol, isophorone diisocyanate, sodium hydroxysulfonate styrene monomer, and dibutyltin dilaurate in step (1) is 1:(2.6-2.8):(1.3-1.4):(0.014-0.018); the polyether polyol is polyethylene glycol or polypropylene glycol.

3. The method for preparing the polyurethane acrylic resin finishing agent for improving fabric stiffness according to claim 1, characterized in that: The temperature of the prepolymerization reaction in step (1) is 65-80° C., and the reaction time is 2-3 hours; the time of the end-capping reaction is 40-60 minutes.

4. The method for preparing the polyurethane acrylic resin finishing agent for improving fabric stiffness according to claim 1, characterized in that: The mass ratio of polyurethane acrylate, emulsifier, acrylate monomer, sodium hydroxysulfonate styrene monomer, and azobisisobutyronitrile in step (2) is 100: (7-10): (300-450): (80-140): (8-12).

5. The method for preparing the polyurethane acrylic resin finishing agent for improving fabric stiffness according to claim 1, characterized in that: The polymerization reaction temperature in step (2) is 70-80° C., and the reaction time is 6-8 hours.

6. The method for preparing the polyurethane acrylic resin finishing agent for improving fabric stiffness according to claim 4, characterized in that: The acrylic acid ester monomer is any one or a combination of methyl acrylate, methyl methacrylate, butyl acrylate, and butyl methacrylate.

7. The method for preparing the polyurethane acrylic resin finishing agent for improving fabric stiffness according to claim 4, characterized in that: The emulsifier is sodium dodecylbenzenesulfonate or sodium dodecyl sulfate.

8. The method for preparing the polyurethane acrylic resin finishing agent for improving fabric stiffness according to claim 4, characterized in that: The preparation method of the sodium hydroxysulfonate styrene monomer comprises: adding ethanol, deionized water, sodium 3-chloro-2-hydroxypropanesulfonate, and sodium p-vinylbenzoate into a reaction bottle, stirring and reacting at 60-75° C. for 6-10 hours, adding the product into deionized water after reduced pressure distillation, heating for volatilization, and cooling for crystallization to obtain the sodium hydroxysulfonate styrene monomer.

9. The method for preparing the polyurethane acrylic resin finishing agent for improving fabric stiffness according to claim 8, characterized in that: The molar ratio of the sodium 3-chloro-2-hydroxypropanesulfonate to sodium p-vinylbenzoate is (1-1.2):1.

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