Fluorine-free durable fabric finishing agent, preparation method and application thereof

Abstract

The application discloses a fluorine-free durable fabric finishing agent as well as a preparation method and application thereof, and belongs to the technical field of textile materials. 12 The fabric finishing agent has the following molecular structure, for example: wherein R is an alkyl chain with 4 to 6 carbon atoms; R1 is a polydimethylsiloxane group; and n is a polymerization degree, which can be firmly adhered to the surface of natural fibers to form a coating with excellent mechanical properties and scrub resistance, and is particularly suitable for textile products or high-end garment fabrics which need to withstand repeated washing, rubbing and complex environments.

Description

TECHNICAL FIELD

[0001] The present application relates to a fabric finishing agent, in particular to a fluorine-free durable fabric finishing agent, and a preparation method and application thereof, and belongs to the technical field of textile materials. BACKGROUND

[0002] With the continuous growth of consumer demand for functional textiles, chemical finishing agents that endow fabrics with wrinkle resistance, water resistance, antibacterial properties, flame retardance, etc. have become the core auxiliaries of modern textile industry. However, the existing finishing agents have significant bottlenecks in terms of durability. During the washing process of fabrics, the finishing agents are easily detached from the surface of fibers or chemically degraded due to mechanical friction, chemical action of detergents (surfactants), temperature, and dissolution / swelling of water, which specifically manifests in the decrease of water resistance of fabrics, weakening of wrinkle resistance, failure of easy stain removal, and deterioration of soft hand feeling. At the same time, during daily wearing and use, the finishing agent coating on the surface of fabrics is physically worn or peeled off due to the friction between the fabrics and the skin, other fabrics, or the surface of objects, which specifically manifests in the loss of local function of fabrics (such as water resistance failure at the knee, elbow, and collar), and the thinning or even peeling off of the finishing agent coating. Therefore, it is of great significance to develop a finishing agent system that can firmly adhere to the surface of fibers and resist strong detergents and repeated mechanical action. SUMMARY

[0003] In view of the defects in the prior art, a first object of the present application is to provide a fluorine-free durable fabric finishing agent that can firmly adhere to the surface of fibers and form a coating with excellent mechanical properties and scrub resistance.

[0004] A second object of the present application is to provide a preparation method of the fluorine-free durable fabric finishing agent, which is simple to operate, low in cost, and mild in conditions, and is conducive to industrialized production.

[0005] A third object of the present application is to provide an application of the fluorine-free durable fabric finishing agent, which is used for the treatment of natural fiber fabrics, can firmly adhere to the surface of fibers, and form a coating with excellent mechanical properties and scrub resistance, and is particularly suitable for textiles or high-end garment fabrics that need to withstand repeated washing, friction, and complex environments.

[0006] In order to achieve the above technical objects, the present application provides a fluorine-free durable fabric finishing agent, which has the following molecular structure:

[0007] ;

[0008] or,

[0009] ;

[0010] wherein,

[0011] R is C4~C 12 alkyl chain;

[0012] R1 is a polydimethylsiloxane group;

[0013] n is the degree of polymerization.

[0014] The fluorine-free durable fabric finishing agent of the present application has a special molecular structure. On the one hand, the main chain has a folded chain structure, which is due to the π-π stacking of benzene rings and the hydrogen bonding interaction of amide groups or ester groups, so that the polymer main chain forms a regular and ordered folded structure. When subjected to external force, the regular phase structure formed by the folded chain can absorb a large amount of energy to realize the unfolding deformation stretching of the folded chain structure itself, thereby realizing the multiple improvement of the strength and toughness of the fabric finishing agent, and greatly improving the durability of the fabric finishing agent. On the other hand, flexible and hydrophobic silicone segments are introduced into the main chain, which can easily spread into a film on the fiber surface, has excellent water repellency, and the fabric after treatment has a comfortable hand feeling. In addition, the amide groups or ester groups introduced therein are easy to form hydrogen bonds with the fibers, greatly improving the bonding strength of the fabric finishing agent on the fiber surface.

[0015] The fluorine-free durable fabric finishing agent of the present application has a folded chain structure, which can be compared to a "curtain" in a very vivid way. The R (C4~C 12 alkyl chain) acts as a soft chain and can stretch freely, while the benzene ring structure acts as a rigid unit. When there is no external force, based on the π-π stacking of benzene rings and the hydrogen bonding interaction of amide groups on the benzene ring, the benzene ring structures are superimposed, similar to the "curtain" being contracted and gathered. When the external force is greater than the π-π stacking force of the benzene ring and the hydrogen bonding force, the benzene ring structures are unfolded, similar to the "curtain" being stretched and opened.

[0016] As a preferred scheme, the number average molecular weight of the polydimethylsiloxane group is 500~3000. If the molecular weight of the polydimethylsiloxane group is too low, the flexibility and hydrophobicity of the fabric finishing agent will be reduced, and if the molecular weight of the polydimethylsiloxane group is too high, the flexibility and hydrophobicity of the fabric finishing agent can be improved, but the durability is reduced. The number average molecular weight of the polydimethylsiloxane group is further preferably 1000~2000.

[0017] As a preferred scheme, the degree of polymerization n is 20~50.

[0018] The present application also provides a preparation method of a fluorine-free durable fabric finishing agent, which comprises the following steps:

[0019] 1) 3,5-dihydroxybenzoic acid and di-terminal halogenated alkane are subjected to polycondensation reaction to obtain a folded chain polymer;

[0020] 2) the folded-chain polymer is subjected to an amidation or esterification reaction with the polydimethylsiloxane containing terminal amino groups or terminal hydroxyl groups, and the reaction is completed;

[0021] The di-terminal group halogenated alkane has the following molecular structure:

[0022] ;

[0023] wherein,

[0024] R is a C4~C 12 alkyl chain;

[0025] X is a halogen substituent. X is further preferably a chlorine substituent and a bromine substituent which have higher reactivity.

[0026] As a preferred solution, the polycondensation reaction is carried out at a temperature of 60~100℃ for 24~36h with tetramethyl guanidine as a catalyst.

[0027] As a preferred solution, the mass ratio of the folded-chain polymer to the polydimethylsiloxane containing terminal amino groups or terminal hydroxyl groups is 1:1.2~1.8. The polydimethylsiloxane containing terminal amino groups or terminal hydroxyl groups is mainly grafted on the main chain of the folded-chain polymer through its terminal hydroxyl groups or terminal amino groups. The higher the grafting amount is, the better the softness and the hydrophobicity of the fabric finishing agent are, but the durability is reduced. Therefore, the appropriate grafting rate needs to be controlled to obtain a fabric finishing agent with good comprehensive performance of flexibility, hydrophobicity and durability.

[0028] As a preferred solution, the amidation or esterification reaction is carried out at 60~100℃ for 6~12h with DCC reagent. Tetrahydrofuran is used as a solvent for the amidation or esterification reaction. Cyclohexyl carbodiimide (DCC) is used as a catalyst to improve the efficiency of the amidation or esterification reaction. The addition amount of DCC is 1.1~1.5 times the mass of the folded-chain polymer.

[0029] The application further provides an application of the fluorine-free durable finishing agent as a natural fiber fabric finishing agent.

[0030] The fluorine-free durable finishing agent of the application can be stably combined on the surface of the fiber, uniformly form a film, and form a coating layer with excellent mechanical properties and scrub resistance, which can withstand repeated washing, rubbing resistance, and comfortable hand feeling.

[0031] As a preferred scheme, the fluorine-free durable fabric finishing agent is diluted with isopropyl alcohol to form a finishing liquid, and the natural fiber fabric is treated by padding-drying-curing method. The isopropyl alcohol as a diluent can not only adjust the viscosity of the fluorine-free durable finishing agent to ensure the uniformity of padding, but also reduce the surface tension to promote the penetration of the finishing agent into the interior of the fiber.

[0032] As a preferred scheme, the mass concentration of the fluorine-free durable fabric finishing agent in the finishing liquid is 4% to 20%.

[0033] As a preferred scheme, the natural fiber fabric is cotton fiber.

[0034] The preparation process of the fluorine-free durable fabric finishing agent of the present application is as follows (taking 3,5-dihydroxybenzoic acid, 1,6-dibromohexane and amino-terminated polydimethylsiloxane as an example for illustration):

[0035] ;

[0036] ;

[0037] Compared with the prior art, the technical scheme of the present application has the following beneficial technical effects:

[0038] (1) The fluorine-free durable fabric finishing agent of the present application has excellent durability and mechanical properties. On the one hand, it has strong physical wear resistance. Based on the intermolecular π-π interaction and hydrogen bond formation of the agent, a regular and ordered folded structure is formed. Under external force, the agent absorbs energy by unfolding, significantly improving the strength and toughness of the agent, and effectively resisting the peeling of the coating caused by daily friction, washing mechanical force (such as vulnerable parts such as elbows, collar, etc.); on the other hand, it has excellent chemical degradation resistance. The unique molecular structure design enhances the resistance to detergents (surfactants), high-temperature washing and swelling, delays chemical degradation, and maintains functionality (such as water resistance, wrinkle resistance) for a long time.

[0039] (2) The fluorine-free durable fabric finishing agent of the present application avoids the introduction of fluorine-containing hydrophobic groups and does not contain traditional fluorine-containing water repellents such as PFAS, avoiding potential ecological toxicity and meeting the development trend of green chemicals.

[0040] (3) The fluorine-free durable fabric finishing agent of the present application based on grafted polydimethylsiloxane (PDMS) can uniformly spread on the surface of the fabric to form a film, giving the natural fiber (such as cotton) persistent water repellency. The flexibility of PDMS ensures that the finished fabric remains soft and skin-friendly, avoiding the stiffness problem caused by traditional durable finishing agents.

[0041] (4) The fluorine-free durable fabric finishing agent of the present application has mild synthesis process conditions and is easy to be industrialized. For example, tetramethyl guanidine is used as a catalyst to enable synthesis at low or medium temperature, without harsh conditions (such as high temperature and high pressure), low energy consumption and simple operation.

[0042] (5) The fluorine-free durable fabric finishing agent of the present application is processed by using a conventional padding-drying-curing method to treat the fabric, without the need of special equipment. The natural fiber fabric treated by using the fluorine-free durable fabric finishing agent has excellent mechanical properties and scrub resistance, and is particularly suitable for textile products or high-end garment fabrics that need to withstand repeated washing, rubbing and complex environments. BRIEF DESCRIPTION OF DRAWINGS

[0043] Figure 1 NMR hydrogen spectrum of the folded chain polymer prepared for Example 1.

[0044] Figure 2 NMR hydrogen spectrum of the fluorine-free durable fabric finishing agent prepared for Example 1. DETAILED DESCRIPTION

[0045] The following specific examples are intended to further illustrate the present application, but not to limit the protection scope of the claims of the present application.

[0046] The chemical reagents involved in the following specific examples are all conventional commercially available products if not specifically stated.

[0047] Examples 1-5

[0048] Synthesis of the fluorine-free durable fabric finishing agent:

[0049] Take 3,5-dihydroxybenzoic acid (1.54 g, 10 mmol) in a round-bottom flask, add anhydrous acetonitrile (30 mL) and stir the mixture. Then add tetramethyl guanidine (25 mmol), 1,6-dibromohexane (2.32 g, 9.5 mmol), and reflux at 80°C for 12 hours. After the reaction is completed, remove the solvent, add ethyl acetate and water for extraction, and dry the organic phase with anhydrous sodium sulfate to obtain the folded chain polymer.

[0050] Take 2 g of the above folded chain polymer and 2.5 g of DCC in a round-bottom flask, add tetrahydrofuran (20 mL) and stir the mixture, then add amino-terminated polysiloxane (number average molecular weight 1500), and react at 80°C for 8 h. After the reaction is completed, remove the solvent, add ethyl acetate and water for extraction, and dry the organic phase with anhydrous sodium sulfate.

[0051] Examples 1-5 are the synthesis of fluorine-free durable fabric finishing agents with different mass ratios of folded chain polymers and amino-terminated polysiloxane, as shown in Table 1 below:

[0052] ;

[0053] Fabric treatment:

[0054] 1) Finishing liquor preparation: Take an appropriate amount of finishing agent, add isopropyl alcohol, and configure into a solution with a mass fraction of 10%, stir for 30 minutes to homogeneity.

[0055] 2) Pad: Cotton fabric (142 g / m²) is treated by two dip-two-nip (pressure 0.3 MPa, speed 2 m / min).

[0056] 3) Pre-drying: Hot air drying at 100°C for 3 minutes.

[0057] 4) Curing: Curing at 60°C for 2 minutes.

[0058] 5) Post-treatment: Washed twice in cold water and dried at 80°C for 5 minutes.

[0059] The effects of the fluorine-free durable fabric finishing agents synthesized in Examples 1-5 on cotton fabric treatment are shown in Table 2, and the performance test standards are shown in Table 3.

[0060] ;

[0061] ;

[0062] From the experimental data in Table 2, it can be seen that:

[0063] After the cotton fabric is treated with the fluorine-free durable fabric finishing agents synthesized in Examples 1-5, the contact angle of the obtained cotton fabric is 146.8°-164.2°, all higher than 130°, indicating that the hydrophobicity of the cotton fabric treated with the fluorine-free durable fabric finishing agent is higher than that of the cotton fabric treated with the existing conventional commercial hydrophobic agent.

[0064] The contact angle of the cotton fabric treated with the fluorine-free durable fabric finishing agent of Example 2 is relatively small, being 146.8°, and after 50 washes, the contact angle is 143.3°, with a decay of only 2.4%, while the contact angle of the cotton fabric treated with the fluorine-free durable fabric finishing agent of Example 5 is relatively large, being 164.2°, and after 50 washes, the contact angle is 148.8°, with a decay of 9.4%, indicating that the amount of polysiloxane grafting affects the hydrophobicity and durability of the fluorine-free durable fabric finishing agent. The higher the polysiloxane grafting ratio, the better the hydrophobicity, but the worse the durability.

[0065] After the cotton fabric is treated with the fluorine-free durable fabric finishing agents synthesized in Examples 1-5, the hand feeling of the obtained cotton fabric changes from slightly crisp, slightly hard, moderate, soft, to smooth and greasy, indicating that the amount of polysiloxane grafting affects the hand feeling of the fluorine-free durable fabric finishing agent. The higher the polysiloxane grafting ratio, the better the hand feeling.

[0066] In summary, the mass ratio of the folded-chain polymer to the polydimethylsiloxane containing terminal amino group is further preferably 1 : 1.2 ~ 1.8, in which range, the comprehensive properties of flexibility, hydrophobicity and durability can be ensured.

Claims

1. A fluorine-free durable fabric finishing agent, characterized in that: It has the following molecular structure: ， or, ， in, R is C4~C 12 alkyl chains; R1 is a polydimethylsiloxane group; n is 20~50.

2. The fluorine-free durable fabric finishing agent according to claim 1, characterized in that: The number average molecular weight of the polydimethylsiloxane group is 500-3000.

3. The method for preparing a fluorine-free durable fabric finishing agent according to claim 1 or 2, characterized in that: Includes the following steps: 1) 3,5-Dihydroxybenzoic acid and di-terminated haloalkanes undergo a polycondensation reaction to obtain a folded-chain polymer; 2) The folded-chain polymer is reacted with polydimethylsiloxane containing terminal amino or hydroxyl groups through amidation or esterification to obtain the product; The di-terminated haloalkane has the following molecular structure: ， in, R is C4~C 12 alkyl chains; X is a halogen substituent.

4. The method for preparing a fluorine-free durable fabric finishing agent according to claim 3, characterized in that: The conditions for the polycondensation reaction are: using tetramethylguanidine as a catalyst, reacting at a temperature of 60℃~100℃ for 24~36h.

5. The method for preparing a fluorine-free durable fabric finishing agent according to claim 3, characterized in that: The mass ratio of the folded chain polymer to the polydimethylsiloxane containing terminal amino or hydroxyl groups is 1:1.2~1.

8.

6. The method for preparing a fluorine-free durable fabric finishing agent according to claim 3, characterized in that: The conditions for the amidation or esterification reaction are: under the action of DCC reagent, at 60~100℃, for 6~12 hours.

7. The application of the fluorine-free durable fabric finishing agent according to claim 1 or 2, characterized in that: It is used as a finishing agent for natural fiber fabrics.

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

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

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

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