Fluoride-free multifunctional fabric finishing agent as well as preparation method and application thereof

Abstract

The invention discloses a fluoride-free multifunctional fabric finishing agent as well as a preparation method and application thereof, and belongs to the technical field of textile materials. The fluorine-free multifunctional fabric finishing agent has the following molecular structure: in the formula, one of R1, R2 and R3 is H, one is H, and the other is H; r4 is alkyl with 1 to 4 carbon atoms; and R5 is an aliphatic chain of C11-C23. The fabric finishing agent does not contain fluorine and substances capable of easily releasing formaldehyde, has hydrophobic, flame-retardant and antibacterial properties, and can be widely applied to natural fiber treatment.

Description

Technical Field

[0001] This invention relates to a fabric finishing agent, particularly a fluorine-free multifunctional fabric finishing agent, as well as its preparation method and application, belonging to the field of textile materials technology. Background Technology

[0002] The textile industry is diversified and large-scale, with competing products including fibers, fabrics, raw materials, home furnishings, and most importantly, clothing. Natural fibers, as important textile raw materials, are widely used in clothing and home furnishings due to their biodegradability and versatility, thanks to their excellent properties such as breathability, comfort, economy, softness, and warmth. However, despite their biodegradability, the flammability of natural cellulose makes them prone to causing fires, leading to significant personal and economic losses. Furthermore, natural fibers are rich in hydroxyl groups and porous structures, providing a favorable environment for water absorption and bacterial growth, making them easily stained. Therefore, these drawbacks of natural fibers limit their applications. For example, in everyday life or in places like hospitals and laboratories, fabrics are required to have flame-retardant, self-cleaning, and antibacterial properties. In applications such as outdoor clothing, automotive interiors, fire-fighting suits, tents, and military uniforms, fabrics are required to be waterproof and flame-retardant.

[0003] Currently, hydrophobic treatment of natural fiber fabrics is usually achieved through a two-step process: (1) constructing a rough structure on a cotton substrate using nanomaterials; and (2) chemically modifying the substrate with low surface energy materials. Fluorides are widely used to prepare hydrophobic surfaces due to their low surface energy. However, fluorine may be harmful to humans and the environment, posing risks such as carcinogenicity, damage to children's immune systems, and reduced female fertility. Therefore, many countries have banned the use of fluorides in hydrophobic surfaces. Superhydrophobic surfaces can be prepared by combining nano / micro particles with low surface energy materials, but the coating method reduces durability when applied to cotton fabrics because the coating material cannot form covalent bonds with cellulose fibers. The flammability of natural fiber fabrics is mainly achieved by using flame retardants, which are generally classified into four categories: halogenated, organophosphorus, inorganic metal oxides, and nitrogen-based. Halogenated flame retardants have been banned due to their toxicity. Natural fabrics treated with phosphorus-based flame retardants (such as Pyrovatex CP and Proban) may release formaldehyde during use. In recent years, bio-based flame retardants such as DNA (deoxyribonucleic acid) and phytic acid have been reported. In addition, novel nanomaterials such as graphene, nano-silica, and carbon nanotubes have also been used as flame retardants. However, natural fiber fabrics using these flame retardants often lack durability. Furthermore, although many treatment agents impart flame retardancy, water resistance, and antibacterial properties to natural fiber fabrics, treatment agents possessing flame retardancy, superhydrophobicity, and antibacterial properties simultaneously are almost never reported. Summary of the Invention

[0004] In view of the shortcomings of the existing technology, the first objective of the present invention is to provide a fluorine-free multifunctional fabric finishing agent that does not contain fluorine or substances that easily release formaldehyde, and simultaneously possesses hydrophobic, flame-retardant and antibacterial properties, and can be widely used in the treatment of natural fibers.

[0005] The second objective of this invention is to provide a method for preparing a fluorine-free multifunctional fabric finishing agent, which is simple to operate, low in cost, and mild under mild conditions, making it suitable for industrial production.

[0006] The third objective of this invention is to provide an application of a fluorine-free multifunctional fabric finishing agent, which, when used to treat natural fiber fabrics, imparts good hydrophobicity, flame retardancy, and antibacterial properties to the natural fabrics.

[0007] To achieve the above-mentioned technical objectives, the present invention provides a fluorine-free multifunctional fabric finishing agent having the following molecular structure:

[0008]

[0009] in,

[0010] Among R1, R2, and R3, one is H, and one is... One is ;

[0011] R4 is a C1~C4 alkyl group;

[0012] R5 is C 11 ~C 23 Fat chains.

[0013] The fluorine-free multifunctional fabric finishing agent of this invention has a special molecular structure, containing long aliphatic chains, alkoxysilane groups, phenolic hydroxyl groups, and quaternary ammonium phosphate groups. The presence of these functional groups endows natural fiber fabrics with excellent hydrophobicity, flame retardancy, and antibacterial properties. The alkoxysilane groups in the finishing agent's molecular structure readily react with the hydroxyl groups in natural fibers through chemical bonding, thereby improving the durability and stability of the finishing agent's effect on natural fibers. The presence of phenolic hydroxyl groups and quaternary ammonium ions in the molecular structure can disrupt the cell membranes of microorganisms (especially Gram-negative bacteria such as Escherichia coli), exhibiting certain antibacterial activity. Furthermore, the quaternary ammonium phosphate groups in the molecular structure readily decompose at high temperatures to generate NH3 and PO· free radicals, capturing active free radicals in combustion chain reactions to generate polyphosphoric acid (HPO3), promoting the dehydration and char formation of cellulose, isolating oxygen and heat, and NH4· + With PO4 3- Together, they reduce the toxicity of combustion smoke; the long fatty chains in the molecular structure of the finishing agent have poor compatibility with the hydrophilic natural fiber fabric, and are mainly free on the surface of the natural fiber fabric, playing a good role in surface hydrophobicity.

[0014] In the molecular structure of the fluorine-free multifunctional fabric finishing agent of the present invention, R4 is a substituent group in a siloxane, which acts as a leaving group during hydrolysis. A smaller molecular weight is more conducive to leaving the siloxane, and it is preferably a short-chain alkyl group (C1-C4). R5 is a long aliphatic chain, which can be a saturated or unsaturated aliphatic chain. The length of the long aliphatic chain mainly affects its hydrophobicity; the longer the chain, the higher the hydrophobicity. However, excessively long aliphatic chains lead to poor solubility, and longer chains also make the fabric stiffer and less supple, which is not conducive to its use as a fabric finishing agent. Therefore, a C1-C4 short-chain alkyl group is preferred. 11 ~C 23 The fatty acid chain can be a straight fatty acid chain or a branched fatty acid chain. The most preferred is C. 15 Fat chains.

[0015] This invention also provides a method for preparing a fluorine-free multifunctional fabric finishing agent, the method of which involves using C 12 ~C 24 The long-chain fatty acids, diammonium hydrogen phosphate and gallic acid are esterified to obtain an intermediate; the intermediate is then added to isocyanopropyltrialkoxysilane to obtain a fluorine-free multifunctional fabric finishing agent.

[0016] The isocyanopropyltriethoxysilane has the following molecular structure:

[0017] ;

[0018] R4 is a C1 to C4 alkyl group.

[0019] As a preferred embodiment, the molar ratio of the long-chain fatty acid, gallic acid, diammonium hydrogen phosphate, and isocyanopropyltrialkoxysilane siloxane is 1:(0.3~1):(0.5~2):(1.0~1.5). Controlling the proportions of various raw materials within a suitable range is beneficial for obtaining a fluorine-free multifunctional fabric finishing agent with comprehensive hydrophobic, flame-retardant, and antibacterial properties. If the proportion of long-chain fatty acids is too high, the proportion of long-chain fatty groups bound in the fluorine-free multifunctional fabric finishing agent will be too high, leading to poor solubility and causing the fabric to become stiff and less supple, which is unfavorable for use as a fabric finishing agent. Conversely, if the proportion of long-chain fatty acids is too low, the proportion of long-chain fatty groups bound in the fluorine-free multifunctional fabric finishing agent will be too low, resulting in poor hydrophobic properties. Conversely, if the proportion of diammonium hydrogen phosphate is too high, it will increase the hydrophilicity of the fabric finishing agent and reduce its durability; while if the proportion of diammonium hydrogen phosphate is too low, the flame-retardant properties of the fabric finishing agent will be poorer. When the proportion of isocyanopropyltrialkoxysilane siloxane used is too low, the bonding strength of the fluorine-free multifunctional fabric finishing agent on the fabric will be reduced. The molar ratio between the long-chain fatty acid, the gallic acid, the diammonium hydrogen phosphate and the isocyanopropyltrialkoxysilane siloxane is further preferably 1:(0.6~0.8):(1.0~1.3):(1.0~1.2).

[0020] As a preferred embodiment, the esterification reaction is carried out under the following conditions: using p-toluenesulfonic acid as a catalyst, and reacting at a temperature of 100℃~120℃ for 6~12h.

[0021] As a preferred embodiment, the addition reaction is performed at a temperature of 60-100°C for 8-12 hours.

[0022] This invention also provides an application of a fluorine-free multifunctional fabric finishing agent, which is used as a finishing agent for natural fiber fabrics.

[0023] As a preferred embodiment, the fluorine-free multifunctional finishing agent is diluted with isopropanol to form a finishing solution, which is then used to treat natural fiber fabrics via a padding-drying-baking method. The isopropanol, as a diluent, not only adjusts the viscosity of the finishing agent to ensure uniform padding, but also reduces surface tension, promoting the penetration of the finishing agent into the fiber interior.

[0024] As a preferred embodiment, the mass concentration of the fluorine-free multifunctional fabric finishing agent in the finishing solution is 4% to 20%. More preferably, the mass concentration of the fluorine-free multifunctional fabric finishing agent in the finishing solution is 8% to 15%.

[0025] As a preferred embodiment, the natural fiber fabric is cotton fiber.

[0026] The preparation process of the fluorine-free multifunctional fabric finishing agent of the present invention involves the following reaction principle:

[0027]

[0028] Among them, one of R1, R2, and R3 is H, and one is... One is ;

[0029] R4 is a C1-C4 alkyl group; R5 is a C1-C4 alkyl group. 11 ~C 23 Fat chains.

[0030] Compared with existing technologies, the beneficial technical effects of the present invention are as follows:

[0031] (1) The fluorine-free multifunctional fabric finishing agent of the present invention achieves the three-in-one function of hydrophobicity, flame retardancy and antibacterial. It only requires one padding-baking to enable natural fiber fabrics to have the characteristics of hydrophobicity, flame retardancy and antibacterial properties. In contrast, the existing technology to achieve the multifunctionality of natural fibers usually requires step-by-step hydrophobic finishing (fluorine-containing compounds), flame retardant finishing (formaldehyde-based flame retardant) and antibacterial treatment (silver ions or quaternary ammonium salts). The process is complicated, energy consumption is high, and it is easy to cause performance conflicts.

[0032] (2) The fluorine-free multifunctional fabric finishing agent of the present invention is free of fluorine elements and does not contain substances that easily release formaldehyde, which overcomes the defects of the prior art that relies on perfluorinated compounds (PFOA / PFOS) with bioaccumulation and toxicity to impart hydrophobic function, and uses formaldehyde-based resins (such as Pyrovatex CP) that easily release carcinogens as flame retardants.

[0033] (3) The fluorine-free multifunctional fabric finishing agent of the present invention can be easily bonded to the surface of natural fiber fabrics through chemical bonds, greatly improving durability and overcoming the defects of existing finishing agents that are easily washed off through physical adsorption or nano-coating.

[0034] (4) The preparation method of the fluorine-free multifunctional fabric finishing agent of the present invention is simple, easy to operate, and low in cost, and is suitable for industrial-scale production. Attached Figure Description

[0035] Figure 1 The 1H NMR spectrum of the fluorine-free multifunctional fabric finishing agent prepared in Example 2. Detailed Implementation

[0036] The following specific embodiments are intended to further illustrate the content of the present invention, rather than to limit the scope of protection of the claims.

[0037] Examples 1-7

[0038] 1) Premixing: Add stearic acid, gallic acid and diammonium hydrogen phosphate to the reaction flask and stir for 20 minutes until uniformly dispersed.

[0039] 2) Catalyst addition: Add p-toluenesulfonic acid, the amount of which is 1.1 times the molar amount of stearic acid.

[0040] 3) Esterification reaction: Maintain the reaction at 120℃ for 10 hours, and recover volatile byproducts (such as water) through a condenser.

[0041] 4) Grafted siloxane: Cool to 80℃, add isocyanopropyltrimethoxysilane and react for 10h. The amount added is 1.2 times the molar amount of stearic acid.

[0042] The proportions of stearic acid, gallic acid, and diammonium hydrogen phosphate used in the preparation of fluorine-free multifunctional fabric finishing agents in Examples 1-7 are shown in Table 1.

[0043]

[0044] Among them, PA (octadecanoic acid), GA (gallic acid), and DAHP (diammonium hydrogen phosphate).

[0045] The fluorine-free multifunctional fabric finishing agents prepared in Examples 1-7 are sequentially labeled as: PGD-1, PGD-2, PGD-3, PGD-4, PGD-5, PGD-6 and PGD-7.

[0046] The structural characterization of fluorine-free multifunctional fabric finishing agent is based on PGD-2 as an example; the main components of PGD-2 are a mixture of isomers A, B and C, wherein the molar ratio of A, B and C is approximately 1:1:2;

[0047] The structural formula of isomer A is:

[0048]

[0049] The structural formula of isomer B is:

[0050] The structural formula of isomer C is:

[0051]

[0052] The 1H NMR characterization of the fluorine-free multifunctional fabric finishing agent PGD-2 is as follows: Figure 1 As shown, Figure 1 The approximate hydrogen shift distribution in the PGD-2 molecular structure can be seen from the data: a represents the hydrogen shift of the ammonium ion, b and c represent the hydrogen shifts of the benzene ring, d represents the hydrogen shift of the phenolic hydroxyl group, e represents the hydrogen shift of the imine group, f, h, j, k and l represent the hydrogen shifts on the saturated hydrocarbon chain, and i represents the hydrogen shift of the methyl group.

[0053] The main components of the fluorine-free multifunctional fabric finishing agents PGD-1, PGD-3, PGD-4, PGD-5, PGD-6, and PGD-7 are also mixtures of isomers A, B, and C. However, the total content of isomers A, B, and C is relatively lower than that of PGD-1, while the content of by-products is relatively higher. By-products include by-products grafted with 2 or 3 octadecanoic acid molecules, or by-products grafted with 2 or 3 isocyanopropyltrimethoxysilane molecules, or by-products grafted with only 1 octadecanoic acid molecule or only 1 isocyanopropyltrimethoxysilane molecule.

[0054] Application Examples

[0055] 1) Preparation of finishing solution: Take an appropriate amount of finishing agent (PGD-1, PGD-2, PGD-3, PGD-4, PGD-5, PGD-6 and PGD-7 respectively), add isopropanol, prepare a 15% mass fraction solution, and stir for 30 minutes until homogeneous.

[0056] 2) Impregnation and padding: The cotton fabric (142 g / m²) is impregnated and padded twice (pressure 0.3 MPa, speed 2 m / min).

[0057] 3) Pre-drying: Dry with hot air at 100℃ for 3 minutes.

[0058] 4) Baking: Baking at 60℃ for 2 minutes.

[0059] 5) Post-treatment: Wash twice with cold water and dry at 80℃ for 5 minutes.

[0060] The antibacterial, flame retardant, hydrophobic, and durable properties of the fluorine-free multifunctional fabric finishing agents prepared in Examples 1-7 after treatment of cotton fabrics are shown in Table 2, and the test standards are shown in Table 3.

[0061]

[0062] The finishing agent has a mass concentration of 15%.

[0063] 1) As can be seen from Examples 1-3, the proportion of octadecanoic acid mainly affects hydrophobicity and the hand feel of the fiber fabric: Example 3 shows that the proportion of octadecanoic acid is relatively low, with a contact angle of 145.2°, indicating relatively poor hydrophobicity; Example 1 shows that the proportion of octadecanoic acid is relatively high, with the contact angle increasing to 153.1°, but the fabric becomes slightly stiff (due to excessive accumulation of long-chain alkyl groups). The proportion of octadecanoic acid in Example 2 is the optimal value, which can balance hydrophobicity and hand feel.

[0064] 2) As can be seen from Examples 2, 4-5, the proportion of gallic acid mainly affects cross-linking and antibacterial properties: Example 4 shows that the proportion of gallic acid is too low, and its inhibition zone is only 0.15 mm, and insufficient cross-linking leads to a slight decrease in durability; Example 5 shows that the proportion of gallic acid is too high, and its antibacterial properties are enhanced (0.32 mm), but excessive carboxyl groups will cause the fiber to turn yellow (acidic degradation).

[0065] 3) As can be seen from Examples 2, 6-7, the proportion of diammonium hydrogen phosphate mainly affects the flame retardancy: Example 6 shows that the proportion of diammonium hydrogen phosphate is relatively low, with an LOI of 24.8%, and the flame retardancy is slightly lower than the flame-retardant standard (LOI≥26%); Example 7 shows that the proportion of diammonium hydrogen phosphate is relatively high, with an LOI of 28.1%, but there may be residual unreacted phosphorus compounds.

[0066]

[0067] Examples 8-12

[0068] The preparation method of the fluorine-free multifunctional fabric finishing agent is as described in Example 2.

[0069] The application of the fluorine-free multifunctional fabric finishing agent is described in the application examples, except that the concentration of the finishing solution is different. Table 4 shows the preparation of finishing solutions of different concentrations using the fluorine-free multifunctional fabric finishing agent prepared in Example 2, and Table 5 shows the antibacterial, flame retardant, hydrophobic, and durable properties of cotton fabrics after being treated with different finishing solutions.

[0070]

[0071]

Claims

1. A fluorine-free, multifunctional fabric finishing agent, characterized in that: It has the following molecular structure: ； in, Among R1, R2, and R3, one is H, and one is... One is ; R4 is a C1~C4 alkyl group; R5 is C 11 ~C 23 Fat chains.

2. The preparation method of the fluorine-free multifunctional fabric finishing agent according to claim 1, characterized in that: C 12 ~C 24 Long-chain fatty acids, diammonium hydrogen phosphate, and gallic acid undergo esterification to obtain an intermediate; the intermediate undergoes an addition reaction with isocyanopropyltrialkoxysilane to obtain a fluorine-free multifunctional fabric finishing agent. The isocyanopropyltriethoxysilane has the following molecular structure: ； R4 is a C1 to C4 alkyl group.

3. The method for preparing a fluorine-free multifunctional fabric finishing agent according to claim 2, characterized in that: The C 12 ~C 24 The molar ratio of the long-chain fatty acid, the gallic acid, the diammonium hydrogen phosphate and the isocyanopropyltrialkoxysilane is 1:(0.3~1):(0.5~2):(1.0~1.5).

4. The method for preparing a fluorine-free multifunctional fabric finishing agent according to claim 2 or 3, characterized in that: The esterification reaction conditions are as follows: using p-toluenesulfonic acid as a catalyst, the reaction is carried out at a temperature of 100℃~120℃ for 6~12h.

5. The method for preparing a fluorine-free multifunctional fabric finishing agent according to claim 2 or 3, characterized in that: The conditions for the addition reaction are: reaction at 60℃~100℃ for 8~12h.

6. The application of the fluorine-free multifunctional fabric finishing agent according to claim 1, characterized in that: It is used as a finishing agent for natural fiber fabrics.

7. The application of the fluorine-free multifunctional fabric finishing agent according to claim 6, characterized in that: The fluorine-free multifunctional finishing agent is formed by diluting isopropanol into a finishing solution, which is then used to treat natural fiber fabrics through a padding-drying-baking method.

8. The application of the fluorine-free multifunctional fabric finishing agent according to claim 7, characterized in that: The mass concentration of the fluorine-free multifunctional fabric finishing agent in the finishing solution is 4%~20%.

9. The application of the fluorine-free multifunctional fabric finishing agent according to claim 7, characterized in that: The natural fiber fabric is cotton fiber.

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