Aqueous fluorine-free low-temperature water repellent finishing agent, preparation method and application thereof

Abstract

The application relates to the technical field of finishing agents, and discloses a water-based fluorine-free low-temperature water-repellent finishing agent and a preparation method and application thereof. 2,2-dimethylol propionic acid alkyl ester and methyl phenyl dichlorosilane are reacted to obtain an alkyl ester siloxane copolymer, which is then stirred and dispersed with water and an emulsifier to obtain the water-based fluorine-free low-temperature water-repellent finishing agent. The main chain of the water-based fluorine-free low-temperature water-repellent finishing agent is a hydrophobic phenyl polysiloxane molecular chain, and the side chain contains hydrophobic ester groups and long carbon chains. After finishing of terylene fabric, water molecules can be prevented from contacting the terylene surface, and the hydrophobic and water-repellent performance of the terylene fabric is significantly improved. Moreover, a high water contact angle can be maintained after multiple washes.

Description

Technical Field

[0001] This invention relates to the field of finishing agents, specifically to a water-based, fluorine-free, low-temperature water-repellent finishing agent, its preparation method, and its application. Background Technology

[0002] Finishing agents are common textile auxiliaries that impart properties such as hydrophilicity, water repellency, flame retardancy, and softness to fabrics. They are mainly classified as polyester-based, polyether-based, and silicone-based. Water-repellent finishing agents reduce the surface energy of fabrics, giving them water- and oil-repellent properties, as well as stain resistance. Typically, water-repellent finishing agents are fluorinated; however, fluorine is highly toxic, difficult to degrade, and poses significant harm to human health and the environment. Developing fluorine-free water-repellent finishing agents is a research challenge.

[0003] Organosilicon finishing agents are environmentally friendly, possess strong hydrophobic properties, and exhibit high softness, making them widely used. Patent CN113862999B discloses an organic-inorganic nano-hybrid water-repellent finishing agent and its preparation method. This agent is formulated by combining nano-fluorinated graphite-modified organosilicon oil, emulsifiers, and other components, which can impart excellent water-repellent properties to cotton or natural fabrics. However, the nano-fluorinated graphite-modified organosilicon oil in this patent contains fluorine, posing significant pollution and hazard. Summary of the Invention

[0004] (I) Technical problems to be solved: In view of the shortcomings of the existing technology, the present invention provides a water-based fluorine-free low-temperature water-repellent finishing agent, its preparation method and application, which solves the problems that the existing finishing agents contain fluorine elements, which have great pollution and harm, and that the water-repellent finishing agents have poor water-repellent effect.

[0005] (II) Technical Solution: Preparation Method of Water-Based Fluorine-Free Low-Temperature Water-Repellent Finishing Agent:

[0006] Step S1: Add alkyl 2,2-dimethylolpropionate and triethylamine to the reaction solvent, heat to the reaction temperature, add methylphenyl dichlorosilane dropwise, stir the reaction, cool, filter, and distill the filtrate under reduced pressure. Add the product to water, stir, allow to stand and separate into layers, remove the aqueous phase, dry the oil phase, and purify to obtain the alkyl ester siloxane copolymer. The preparation reaction formula is:

[0007]

[0008] Step S2: Add alkyl ester siloxane copolymer and emulsifier to water, stir and disperse to obtain water-based fluorine-free low-temperature water-repellent finishing agent.

[0009] Furthermore, the reaction solvent in step S1 is toluene or dichloromethane.

[0010] Furthermore, in step S1, the reaction temperature is 45-80℃ and the reaction time is 12-24h.

[0011] Furthermore, in step S1, the ratio of alkyl 2,2-dimethylolpropionate, triethylamine, and methylphenyl dichlorosilane is (1-1.1) mol:(2-2.1) mol:1 mol.

[0012] Further, in step S1, the preparation method of alkyl 2,2-dimethylolpropionic acid includes the following steps: adding N,N-dimethylformamide cosolvent, 2,2-dimethylolpropionic acid, and potassium hydroxide to acetonitrile solvent, heating to 100-110℃, refluxing for 1-1.5h, and then adding alkyl bromide, wherein the ratio of 2,2-dimethylolpropionic acid, potassium hydroxide, and alkyl bromide is 1 mol:(1.1-1.2) mol:(1-1.2) mol, and the structural formula of the alkyl bromide is Br-C n H 2n+1 n is 10-18; the reaction is stirred for 12-18 h, followed by vacuum distillation. The product is washed with water and petroleum ether, and then recrystallized in dichloromethane to give alkyl 2,2-dimethylolpropionic acid ester. The preparation reaction formula is:

[0013]

[0014] Furthermore, in step S2, the ratio of water, alkyl ester siloxane copolymer, and emulsifier is 1L:(15-50)g:(0.3-1.2)g.

[0015] Furthermore, in step S2, the emulsifier is any one or a combination of sodium dodecyl sulfate, sodium dodecyl sulfonate, sodium dodecylbenzene sulfonate, and polyether-modified organosilicon.

[0016] Furthermore, water-based, fluorine-free, low-temperature water-repellent finishing agents are applied to polyester fabrics.

[0017] (III) Beneficial technical effects: Methylphenyl dichlorosilane containing hydrophobic benzene rings and with low steric hindrance is polymerized with alkyl 2,2-dimethylolpropionic acid containing hydrophobic ester groups and long carbon chains to obtain alkyl ester siloxane copolymers. Finally, it is compounded with emulsifiers such as sodium dodecylbenzenesulfonate and polyether-modified organosilicon to obtain an emulsion-type water-based fluorine-free low-temperature water-repellent finishing agent. Its main chain is a hydrophobic phenyl polysiloxane molecular chain, and the side chains contain hydrophobic ester groups and long carbon chains. The hydrophobic structure formed by the long carbon chains has a large steric hindrance. After finishing polyester fabrics, it can prevent water molecules from contacting the polyester surface, which significantly improves the hydrophobic and water-repellent properties of polyester fabrics.

[0018] The fluorine-free water-repellent finishing agent of the present invention contains a large number of ester groups, which have good affinity and interfacial interaction with polyester fibers containing polyester structural units, thereby improving the finishing effect and film-forming properties of the finishing agent on polyester. After multiple washes, the finishing agent is not easy to peel off from the polyester surface, has high fastness, and can maintain a high water contact angle after washing.

[0019] The water-repellent finishing agent of the present invention is fluorine-free, environmentally friendly, and the long carbon chain of the side chain mitigates the interaction between polymer chains, which helps to reduce the glass transition temperature, thus having excellent low-temperature film-forming performance. Detailed Implementation

[0020] The embodiments described are provided to better illustrate the present invention, but are not intended to limit the scope of the invention to the embodiments described. Therefore, non-essential improvements and adjustments made to the embodiments by those skilled in the art based on the above description are still within the scope of protection of the present invention.

[0021] Example 1:

[0022] (1) Add 15 mL of N,N-dimethylformamide cosolvent, 70 mmol of 2,2-dihydroxymethylpropionic acid and 77 mmol of potassium hydroxide to 60 mL of acetonitrile solvent, heat to 100 °C, stir and reflux for 1.5 h, then add 77 mmol of 1-bromododecane, stir and react for 12 h, remove the solvent by vacuum distillation, wash the product with water and petroleum ether, and then recrystallize in dichloromethane to obtain alkyl 2,2-dihydroxymethylpropionic acid.

[0023] (2) Add 0.2 mol of alkyl 2,2-dihydroxymethylpropionate and 0.4 mol of triethylamine to 500 mL of toluene, heat to 80 °C, add 0.2 mol of methylphenyl dichlorosilane dropwise, stir and reflux for 12 h, cool, filter, distill the filtrate under reduced pressure, add the product to water, stir and let stand to separate the layers, remove the aqueous phase, dry the oil phase, and purify to obtain alkyl ester siloxane copolymer.

[0024] (3) Add 150g of alkyl ester siloxane copolymer, 1.3g of sodium dodecylbenzene sulfonate, and 1.7g of polyether modified organosilicon (model BSM1194, the same below) to 10L of water, stir and disperse for 20min to obtain water-based fluorine-free low-temperature water-repellent finishing agent.

[0025] Example 2:

[0026] (1) Add 20 mL of N,N-dimethylformamide cosolvent, 70 mmol of 2,2-dihydroxymethylpropionic acid and 77 mmol of potassium hydroxide to 80 mL of acetonitrile solvent, heat to 100 °C, stir and reflux for 1.5 h, then add 84 mmol of 1-bromoeicosane, stir and react for 18 h, remove the solvent by vacuum distillation, wash the product with water and petroleum ether, and then recrystallize in dichloromethane to obtain alkyl 2,2-dihydroxymethylpropionic acid.

[0027] (2) Add 0.2 mol of 2,2-dihydroxymethylpropionic acid alkyl ester and 0.42 mol of triethylamine to 700 mL of dichloromethane, heat to 45 °C, add 0.2 mol of methylphenyl dichlorosilane dropwise, stir and reflux for 24 h, cool, filter, distill the filtrate under reduced pressure, add the product to water, stir and let stand to separate the layers, remove the aqueous phase, dry the oil phase, and purify to obtain alkyl ester siloxane copolymer.

[0028] (3) Add 250g of alkyl ester siloxane copolymer, 2.3g of sodium dodecyl sulfonate and 3.6g of polyether modified organosilicon to 10L of water, stir and disperse for 30min to obtain water-based fluorine-free low-temperature water-repellent finishing agent.

[0029] Example 3:

[0030] (1) Add 15 mL of N,N-dimethylformamide cosolvent, 70 mmol of 2,2-dihydroxymethylpropionic acid and 77 mmol of potassium hydroxide to 60 mL of acetonitrile solvent, heat to 110 °C, stir and reflux for 1 h, then add 70 mmol of 1-bromodecane, stir and react for 12 h, remove the solvent by vacuum distillation, wash the product with water and petroleum ether, and then recrystallize in dichloromethane to obtain alkyl 2,2-dihydroxymethylpropionic acid.

[0031] (2) Add 0.22 mol of alkyl 2,2-dihydroxymethylpropionate and 0.42 mol of triethylamine to 700 mL of dichloromethane, heat to 45 °C, add 0.2 mol of methylphenyldichlorosilane dropwise, stir and reflux for 18 h, cool, filter, distill the filtrate under reduced pressure, add the product to water, stir and let stand to separate the layers, remove the aqueous phase, dry the oil phase, and purify to obtain alkyl ester siloxane copolymer.

[0032] (3) Add 380g of alkyl ester siloxane copolymer, 3.4g of sodium dodecylbenzene sulfonate and 5.7g of polyether modified organosilicon to 10L of water, stir and disperse for 40min to obtain water-based fluorine-free low-temperature water-repellent finishing agent.

[0033] Example 4:

[0034] (1) Add 20 mL of N,N-dimethylformamide cosolvent, 70 mmol of 2,2-dihydroxymethylpropionic acid and 84 mmol of potassium hydroxide to 80 mL of acetonitrile solvent, heat to 100 °C, stir and reflux for 1.5 h, then add 84 mmol of 1-bromohexadecane, stir and react for 12 h, remove the solvent by vacuum distillation, wash the product with water and petroleum ether, and then recrystallize in dichloromethane to obtain alkyl 2,2-dihydroxymethylpropionic acid.

[0035] (2) Add 0.2 mol of alkyl 2,2-dihydroxymethylpropionate and 0.42 mol of triethylamine to 600 mL of toluene, heat to 70 °C, add 0.2 mol of methylphenyl dichlorosilane dropwise, stir and reflux for 18 h, cool, filter, distill the filtrate under reduced pressure, add the product to water, stir and let stand to separate the layers, remove the aqueous phase, dry the oil phase, and purify to obtain alkyl ester siloxane copolymer.

[0036] (3) Add 500g of alkyl ester siloxane copolymer, 4.4g of sodium dodecyl sulfate and 7.6g of polyether modified organosilicon to 10L of water, stir and disperse for 40min to obtain water-based fluorine-free low-temperature water-repellent finishing agent.

[0037] Comparative Example 1:

[0038] (1) Add 0.2 mol of 1,3-propanediol and 0.4 mol of triethylamine to 500 mL of toluene, heat to 80 °C, add 0.2 mol of methylphenyldichlorosilane dropwise, stir and reflux for 12 h, cool, filter and distill the filtrate under reduced pressure, add the product to water, stir and let stand to separate the layers, remove the aqueous phase and dry the oil phase to obtain the siloxane copolymer.

[0039] (2) Add 150g of siloxane copolymer, 1.3g of sodium dodecylbenzenesulfonate and 1.7g of polyether modified organosilicon to 10L of water, stir and disperse for 20min to obtain water-based fluorine-free low-temperature water-repellent finishing agent.

[0040] Comparative Example 2:

[0041] (1) Add 15 mL of N,N-dimethylformamide cosolvent, 70 mmol of 2,2-dimethylolpropionic acid, and 77 mmol of potassium hydroxide to 60 mL of acetonitrile solvent. Heat to 100 °C, stir, and reflux for 1.5 h. Then add 77 mmol of 1-bromoethane and stir for 12 h. Remove the solvent by vacuum distillation, wash the product with water and petroleum ether, and recrystallize in dichloromethane to obtain alkyl 2,2-dimethylolpropionic acid. The structural formula is...

[0042] (2) Add 0.2 mol of alkyl 2,2-dihydroxymethylpropionate and 0.4 mol of triethylamine to 500 mL of toluene, heat to 80 °C, add 0.2 mol of methylphenyl dichlorosilane dropwise, stir and reflux for 12 h, cool, filter and distill the filtrate under reduced pressure, add the product to water, stir and let stand to separate the layers, remove the aqueous phase and dry the oil phase to obtain ester-based siloxane copolymer.

[0043] (3) Add 150g of ester-based siloxane copolymer, 1.3g of sodium dodecylbenzenesulfonate and 1.7g of polyether-modified organosilicon to 10L of water, stir and disperse for 20min to obtain a water-based fluorine-free low-temperature water-repellent finishing agent.

[0044] Comparative Example 3

[0045] (1) Add 0.2 mol of 1,2-dodecanediol (CAS No. 1119-87-5) and 0.4 mol of triethylamine to 500 mL of toluene, heat to 80 °C, add 0.2 mol of methylphenyldichlorosilane dropwise, stir and reflux for 12 h, cool, filter, distill the filtrate under reduced pressure, add the product to water, stir and let stand to separate the layers, remove the aqueous phase, dry the oil phase to obtain alkylsiloxane copolymer.

[0046] (2) Add 150g of alkylsiloxane copolymer, 1.3g of sodium dodecylbenzenesulfonate and 1.7g of polyether modified organosilicon to 10L of water, stir and disperse for 20min to obtain water-based fluorine-free low-temperature water-repellent finishing agent.

[0047] Comparative Example 4:

[0048] (1) Add 0.2 mol of 1,12-dodecanediol (CAS No. 5675-51-4) and 0.4 mol of triethylamine to 500 mL of toluene, heat to 80 °C, add 0.2 mol of methylphenyldichlorosilane dropwise, stir and reflux for 12 h, cool, filter, distill the filtrate under reduced pressure, add the product to water, stir and let stand to separate the layers, remove the aqueous phase, dry the oil phase to obtain alkylsiloxane copolymer.

[0049] (2) Add 150g of alkylsiloxane copolymer, 1.3g of sodium dodecylbenzenesulfonate and 1.7g of polyether modified organosilicon to 10L of water, stir and disperse for 20min to obtain water-based fluorine-free low-temperature water-repellent finishing agent.

[0050] Polyester fabric was subjected to a two-dip, two-nip finishing process using a water-based, fluorine-free, low-temperature water-repellent finishing agent at a liquor ratio of 1:35 and a nip-off rate of 90%. The fabric was then dried at 70°C to constant weight. The water contact angle was tested according to the method specified in GB / T 42694-2023.

[0051] The treated polyester fabric was washed and dried according to the GB / T 8629-2017 standard, repeated 30 times, and then the water contact angle was tested.

[0052] Table 1 Performance of Water-Based Fluorine-Free Low-Temperature Water-Repellent Finishing Agent

[0053]

[0054] As shown in the table above, after the polyester fabrics were treated with water-based fluorine-free low-temperature water-repellent finishing agents in each embodiment, the water contact angle of the polyester reached 128.5-143.4°, exhibiting high hydrophobicity and water repellency. This is mainly because the main chain of the fluorine-free water-repellent finishing agent is a hydrophobic phenyl polysiloxane molecular chain, and the side chains contain hydrophobic ester groups and long carbon chains. The steric structure formed by the long carbon chains has a large steric hindrance, which can prevent water molecules from contacting the polyester surface, significantly improving the hydrophobic and water-repellent properties of the polyester fabric. Furthermore, the high water contact angle is maintained even after multiple washes. This is mainly because the fluorine-free water-repellent finishing agent contains a large number of ester groups, which have good affinity and interfacial interaction with polyester fibers containing polyester structural units, improving the finishing effect and film-forming properties of the finishing agent on the polyester. After multiple washes, the finishing agent is not easily peeled off from the polyester surface, exhibiting high fastness and maintaining a high water contact angle retention rate after washing.

[0055] Comparative Example 1 uses 1,3-propanediol and methylphenyldichlorosilane for polymerization reaction. The resulting fluorine-free water-repellent finishing agent does not contain hydrophobic ester groups or long carbon chains in its side chains. The treated polyester has a low water contact angle, and the water contact angle decreases significantly after washing, resulting in low retention.

[0056] The alkyl 2,2-dimethylolpropionic acid ester of Comparative Example 2 and the water-repellent finishing agent prepared therein do not contain hydrophobic long carbon chains in their side chains. The water contact angle of the treated polyester is low, and the hydrophobic and water-repellent properties are poor.

[0057] Comparative Example 3 uses 1,2-dodecanediol and methylphenyldichlorosilane to carry out a polymerization reaction. The resulting fluorine-free water-repellent finishing agent does not contain ester groups and has weak affinity and interfacial interaction with polyester fibers, resulting in poor finishing effect. After washing, the water contact angle decreases significantly and the retention rate is low.

[0058] Comparative Example 4 uses 1,12-dodecanediol and methylphenyldichlorosilane for polymerization. The resulting water-repellent finishing agent does not contain ester groups and only contains long carbon chains in the main chain. It does not form a hydrophobic structure, has poor hydrophobic and water-repellent properties, and has a low water contact angle.

[0059] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A process for the preparation of an aqueous, fluorine-free, low-temperature water repellent finish, characterized in that, The preparation method comprises the following steps: Step S1, adding alkyl 2,2-dimethylol propionate, triethylamine into a reaction solvent, heating to a reaction temperature, adding methyl phenyl dichlorosilane dropwise, stirring to react, cooling, filtering, distilling the filtrate under reduced pressure, and obtaining alkyl ester siloxane copolymer after purification; Step S2, adding alkyl ester siloxane copolymer, emulsifier into water, stirring and dispersing to obtain water-based fluorine-free low-temperature water-repellent finishing agent; The preparation method of the alkyl 2,2-dimethylol propionate comprises the following steps: adding N,N-dimethylformamide cosolvent, 2,2-dimethylol propionic acid, potassium hydroxide into acetonitrile solvent, heating to 100-110℃, condensing and refluxing for 1-1.5h, then adding alkyl bromide, stirring to react for 12-18h, distilling under reduced pressure, washing the product, and then recrystallizing to obtain alkyl 2,2-dimethylol propionate; The ratio of the 2,2-dimethylol propionic acid, potassium hydroxide, alkyl bromide is 1mol:(1.1-1.2)mol:(1-1.2)mol; The alkyl bromide has the structural formula Br-C n H 2n+1 , n is 10-18.

2. The method for preparing an aqueous non-fluorine low-temperature water repellent finish according to claim 1, characterized by, The reaction solvent in the step S1 is toluene or dichloromethane.

3. The preparation method of the water-based fluorine-free low-temperature water-repellent finishing agent according to claim 1, characterized in that, The reaction temperature in the step S1 is 45-80℃, and the reaction time is 12-24h.

4. The preparation method of the water-based fluorine-free low-temperature water-repellent finishing agent according to claim 1, characterized in that, The ratio of alkyl 2,2-dimethylol propionate, triethylamine, methyl phenyl dichlorosilane in the step S1 is (1-1.1)mol:(2-2.1)mol:1mol.

5. The preparation method of the water-based fluorine-free low-temperature water-repellent finishing agent according to claim 1, characterized in that, The ratio of water, alkyl ester siloxane copolymer, emulsifier in the step S2 is 1L:(15-50)g:(0.3-1.2)g.

6. The preparation method of the water-based fluorine-free low-temperature water-repellent finishing agent according to claim 5, characterized in that, The emulsifier is any one or combination of sodium dodecyl sulfate, sodium dodecyl sulfonate, sodium dodecyl benzene sulfonate, and polyether modified organosilicon.

7. Application of the water-based fluorine-free low-temperature water-repellent finishing agent obtained by the preparation method of any one of claims 1-6 in polyester fabric.

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