Flame-retardant water-resistant polyurethane emulsion

Abstract

The application discloses a kind of flame-retardant waterproof polyurethane emulsion, which is formed by mixing silica sol and silicone-modified polyurethane emulsion, and the mass ratio of the silica sol to the silicone-modified polyurethane emulsion is 1:3.The preparation method includes the following steps: measuring silica sol and silicone-modified polyurethane emulsion according to the proportion respectively; slowly adding the silica sol into the silicone-modified polyurethane emulsion, stirring and dispersing at a speed of 2000 r / min for 40 min to obtain the flame-retardant waterproof polyurethane emulsion.The flame-retardant waterproof polyurethane emulsion has good compatibility and coordination of each component, solves the problem of uneven dispersion of functional components in the system in the prior art, and solves the contradiction between waterproof performance and flame-retardant performance, so as to realize the process of waterproof and flame-retardant finishing in one bath.

Description

Technical Field

[0001] This invention relates to a flame-retardant and waterproof polyurethane emulsion, belonging to the field of functional polyurethane emulsions. Background Technology

[0002] With changing consumer demands, the functions of textile fabrics are constantly evolving and improving, gradually shifting from single-performance to multi-functional integration. The demand for flame-retardant textiles is further increasing, with a focus on multi-functional properties such as flame retardancy, waterproofing, breathability, antibacterial properties, and antistatic properties. The research and development of multi-functional textile fabrics is receiving increasing attention. Compared to ordinary fabrics, outdoor clothing fabrics generally require meeting specific outdoor requirements, such as waterproofing, sun protection, quick-drying, windproofing, breathability, moisture permeability, and flame retardancy.

[0003] Currently, flame-retardant and water-repellent finishing of textiles is mainly divided into step-by-step finishing and co-bath finishing. The step-by-step finishing method mainly suffers from the problem that flame-retardant and water-repellent properties can interfere with each other, while the co-bath finishing method generally has the disadvantages of poor compatibility between flame retardants and water repellents and easy aggregation. Therefore, it is very necessary to develop a textile finishing agent with flame-retardant and water-repellent functions for functional finishing of fabrics.

[0004] Waterborne polyurethane coating agents are highly valued by the textile and apparel industry both domestically and internationally due to their advantages such as highly adjustable molecular structure, strong hiding power, strong adhesion, good film-forming performance, glossy coating, full hand feel, high flexibility, fatigue resistance, wear resistance, cold resistance, and good environmental benefits. However, after waterborne polyurethane film is formed, the film has low thermal stability, poor water resistance, and is flammable, making it difficult to meet the requirements of textile processing.

[0005] Therefore, it is necessary to study multifunctional composite waterborne polyurethanes to better improve their overall performance. Summary of the Invention

[0006] To overcome the shortcomings of existing technologies, the purpose of this invention is to provide a flame-retardant and waterproof polyurethane emulsion for textile finishing and processing, enabling the fabric to possess excellent flame-retardant and waterproof properties.

[0007] To achieve the above objectives, the present invention adopts the following technical solution.

[0008] The flame-retardant and waterproof polyurethane emulsion is composed of silica sol and organosilicon-modified polyurethane emulsion, wherein the mass ratio of the silica sol to the organosilicon-modified polyurethane emulsion is 1:3.

[0009] The silica sol is prepared by the following method:

[0010] The silica sol is prepared from tetraethyl orthosilicate, phosphorus-containing siloxane, ammonia, water, and emulsifier. First, 15 parts of tetraethyl orthosilicate, 5 parts of phosphorus-containing siloxane, 0.3 parts of AEO-3, 0.4 parts of AEO-9, and 0.5 g of sodium dodecyl sulfate are added to 100 parts of distilled water and emulsified and homogenized by high-speed shearing for 30 min. The mixture is then poured into a reaction vessel, heated to 60°C in a water bath, and ammonia is slowly added dropwise to adjust the pH to 8-9. After maintaining the temperature for 6 hours, the mixture is cooled to obtain the silica sol.

[0011] The organosilicon-modified polyurethane emulsion is prepared by the following method:

[0012] 0.4 mol of isophorone diisocyanate was placed in a reactor, stirred, and 0.3 mol of polyethylene glycol (PEG) was added. The temperature was controlled at 75°C, and 3-4 drops of dibutyltin dilaurate were added dropwise. Prepolymerization was carried out for 3 hours.

[0013] Add 0.05 mol of dimethylolpropionic acid and react for 2 h;

[0014] Add 0.02 mol of 1,4-butanediol and allow the chain extension reaction to proceed for 2 hours;

[0015] Add 0.03 mol of dihydroxysiloxane and react for 1 h. Cool the product to 40 °C, add 0.05 mol of triethylamine to neutralize the reaction for 0.5 h, and add distilled water to stir at high speed for 1 h to self-emulsify.

[0016] The temperature was raised to 40℃, and 0.06 mol of long-chain siloxane was slowly added dropwise. The pH value was adjusted to 8-9 with ammonia water. The reaction was carried out for 4 hours and then cooled to room temperature to obtain organosilicon-modified polyurethane emulsion.

[0017] The preparation method of the flame-retardant and waterproof polyurethane emulsion is as follows:

[0018] Take the silica sol and organosilicon-modified polyurethane emulsion in the specified proportions.

[0019] The silica sol was slowly added dropwise to the silicone-modified polyurethane emulsion, and stirred and dispersed at 2000 r / min for 40 min to obtain a flame-retardant and waterproof polyurethane emulsion.

[0020] Waterborne polyurethane possesses excellent weather resistance, flexibility, abrasion resistance, and mechanical properties, making it widely used in the textile industry. However, waterborne polyurethane also has drawbacks such as poor water resistance of its latex films and flammability.

[0021] Organosilicon compounds possess properties such as low surface energy, strong hydrophobicity, excellent flexibility, outstanding oxygen resistance, and low-temperature resistance. Modifying waterborne polyurethane with organosilicon compounds can compensate for and enhance the low-temperature resistance, flexibility, and water resistance of waterborne polyurethane.

[0022] Nano-silica sol has weather resistance. When introduced into waterborne polyurethane, it forms an organic-inorganic composite structure, which gives the polymer better performance.

[0023] When fabrics are treated with flame-retardant and waterproof polyurethane emulsion, the hydrophobic organosilicon located laterally tends to accumulate on the surface during high-temperature curing. This combines with the rough micro-surface formed by the silica sol, thereby improving the hydrophobic properties of the fabric.

[0024] Silicon-based compounds have low environmental impact due to their degradation products, making them recognized as environmentally friendly flame retardants. They also synergistically enhance the flame retardant properties of emulsion systems with phosphorus in polymers.

[0025] The flame-retardant and waterproof polyurethane emulsion has good compatibility and coordination among its components, which solves the problem of uneven dispersion of functional components in the system and difficulty in one-time processing that often occurs in the prior art. This solves the contradiction between waterproof performance and flame retardant performance, and realizes a one-bath process for combining waterproof and flame retardant functions. Attached Figure Description

[0026] Figure 1 This is a static contact angle diagram of polyester fabric after being treated with flame-retardant and waterproof polyurethane emulsion in Example 1. Detailed Implementation

[0027] The unit "parts" of the substances involved in this invention refers to "parts by mass".

[0028] This invention discloses a flame-retardant and waterproof polyurethane emulsion, which is composed of silica sol and organosilicon-modified polyurethane emulsion, wherein the mass ratio of silica sol to organosilicon-modified polyurethane emulsion is 1:3.

[0029] The preparation method of the flame-retardant and waterproof polyurethane emulsion is as follows:

[0030] Take the silica sol and organosilicon-modified polyurethane emulsion in the specified proportions.

[0031] The silica sol was slowly added dropwise to the silicone-modified polyurethane emulsion, and stirred and dispersed at 2000 r / min for 40 min to obtain a flame-retardant and waterproof polyurethane emulsion.

[0032] The silica sol is prepared from tetraethyl orthosilicate, phosphorus-containing siloxane, ammonia, water, and emulsifier. First, 15 parts of tetraethyl orthosilicate, 5 parts of phosphorus-containing siloxane, 0.3 parts of AEO-3, 0.4 parts of AEO-9, and 0.5 g of sodium dodecyl sulfate are added to 100 parts of distilled water and emulsified and homogenized by high-speed shearing for 30 min. The mixture is then poured into a reaction vessel, heated to 60°C in a water bath, and ammonia is slowly added dropwise to adjust the pH to 8-9. After maintaining the temperature for 6 hours, the mixture is cooled to obtain the silica sol.

[0033] The preparation method of the phosphorus-containing siloxane is as follows:

[0034] 0.15 mol of diethyl chlorophosphonate and 50 mL of tetrahydrofuran were added to a clean three-necked flask. The mixture was then protected with nitrogen under ice bath conditions. 0.15 mol of N-methylethanolamine and 0.15 mol of triethylamine were added, and the mixture was stirred for 4 h under ice bath conditions. After filtration, tetrahydrofuran was removed by vacuum distillation to obtain the intermediate.

[0035] In a four-necked flask equipped with a stirrer, thermometer, and condenser, 0.1 mol of the intermediate and 150 ml of DMF (N,N-dimethylformamide) were added. The mixture was heated to 90 °C with stirring and activated for 30 min. Under nitrogen protection, 0.1 mol of KH560 (γ-(2,3-epoxypropoxy)propyltrimethoxysilane) was added, and the mixture was heated to 80 °C and maintained at this temperature for 24 hours. The mixture was filtered, and the DMF in the filtrate was removed by rotary evaporation. Ethyl acetate was added to dissolve the DMF, and the solution was washed three times each with dilute hydrochloric acid, 10% NaOH solution, and saturated NaCl solution. Finally, the solvent was removed by rotary evaporation to obtain the product, i.e., the phosphorus-containing siloxane. The reaction process is shown in reactions 1 and 2.

[0036]

[0037] The organosilicon-modified polyurethane emulsion is prepared by the following method:

[0038] 0.4 mol of isophorone diisocyanate was placed in a reactor, stirred, and 0.3 mol of polyethylene glycol (PEG1000) was added. The temperature was controlled at 75℃, and 3-4 drops of dibutyltin dilaurate were added dropwise. Prepolymerization was carried out for 3 hours.

[0039] Add 0.05 mol of dimethylolpropionic acid and react for 2 h;

[0040] Add 0.02 mol of 1,4-butanediol and allow the chain extension reaction to proceed for 2 hours;

[0041] Add 0.03 mol of dihydroxysiloxane and react for 1 h. Cool the product to 40 °C, add 0.05 mol of triethylamine to neutralize the reaction for 0.5 h, and add 1500 g of distilled water to stir at high speed for 1 h to self-emulsify.

[0042] The temperature was raised to 40℃, and 0.06 mol of long-chain siloxane was slowly added dropwise. The pH value was adjusted to 8-9 with ammonia water. The reaction was carried out for 4 hours and then cooled to room temperature to obtain organosilicon-modified polyurethane emulsion.

[0043] The dihydroxysiloxane is prepared by the following method:

[0044] A di-terminated epoxy polysiloxane (molecular weight 1050) and isopropanol solvent were added to a reactor. After stirring for 30 min, N-(γ,-dimethylaminopropyl)-γ-aminopropylmethyldimethoxysilane (HD-121) was slowly added dropwise. The system was heated to 50 °C and kept at that temperature for 4 h. The solvent was then removed to obtain dihydroxysiloxane.

[0045] The reaction process is shown in the following formula. The molar ratio of the di-epoxy polysiloxane to HD-121 is 1:2.

[0046]

[0047] The long-chain siloxane is prepared by the following method:

[0048] A measured amount of phosphorus-containing siloxane and IPDI (isophorone diisocyanate) were loaded into a reactor under nitrogen protection. A small amount of dibutyltin dilaurate was added to catalyze the reaction, and the temperature was slowly raised to 70°C. The reaction was carried out for about 2 hours until the isocyanate value reached the theoretical content. A measured amount of monohydroxy-terminated dimethicone (Mn = 1000) was added, and the reaction continued until the isocyanate value reached the new theoretical content, yielding the product phosphorus-containing PDMS. The molar ratio of phosphorus-containing siloxane, IPDI, and monohydroxy-terminated dimethicone was 1:1:1. The reaction process is shown in reaction formula 4.

[0049]

[0050] Example 1:

[0051] A flame-retardant and waterproof polyurethane emulsion is composed of silica sol and organosilicon-modified polyurethane emulsion, wherein the mass ratio of silica sol to organosilicon-modified polyurethane emulsion is 1:3.

[0052] The preparation method of the flame-retardant and waterproof polyurethane emulsion is as follows:

[0053] Take the silica sol and organosilicon-modified polyurethane emulsion in the specified proportions.

[0054] The silica sol was slowly added dropwise to the silicone-modified polyurethane emulsion, and stirred and dispersed at 2000 r / min for 40 min to obtain a flame-retardant and waterproof polyurethane emulsion.

[0055] The silica sol is made from tetraethyl orthosilicate, phosphorus-containing siloxane, catalyst, water, and emulsifier. First, 15 parts of tetraethyl orthosilicate, 5 parts of phosphorus-containing siloxane, 0.3 parts of AEO-3, 0.4 parts of AEO-9, and 0.5 g of sodium dodecyl sulfate are added to 100 parts of distilled water and emulsified and homogenized by high-speed shearing for 30 min. The mixture is then poured into a reaction vessel, heated to 60°C in a water bath, and ammonia is slowly added dropwise to adjust the pH value to 8-9. After maintaining the temperature for 6 hours, the mixture is cooled to obtain the silica sol.

[0056] The organosilicon-modified polyurethane emulsion is prepared by the following method:

[0057] 0.4 mol of isophorone diisocyanate was placed in a reactor, stirred, and 0.3 mol of polyethylene glycol (PEG1000) was added. The temperature was controlled at 75℃, and 3-4 drops of dibutyltin dilaurate were added dropwise. Prepolymerization was carried out for 3 hours.

[0058] Add 0.05 mol of dimethylolpropionic acid and react for 2 h;

[0059] Add 0.02 mol of 1,4-butanediol and allow the chain extension reaction to proceed for 2 hours;

[0060] Add 0.03 mol of dihydroxysiloxane and react for 1 h. Cool the product to 40 °C, add 0.05 mol of triethylamine to neutralize the reaction for 0.5 h, and add distilled water to stir at high speed for 1 h to self-emulsify.

[0061] The temperature was raised to 40℃, and 0.06 mol of long-chain siloxane was slowly added dropwise. The pH value was adjusted to 8-9 with ammonia water. The reaction was carried out for 4 hours and then cooled to room temperature to obtain organosilicon-modified polyurethane emulsion.

[0062] Flame-retardant and waterproof polyurethane emulsion is used to finish polyester fabric. The flame-retardant and waterproof polyurethane emulsion is mixed with water to prepare a finishing solution with a concentration of 100 g / L. The fabric is then immersed in the solution, subjected to two dips and two nips, with a nip-out ratio of 80-90%. Pre-drying is performed at 80℃ for 2 minutes, followed by baking at 170℃ for 60 seconds. Fabric: 100% polyester, weight 160 g / m². 2 .

[0063] Water-repellent performance: 100 points.

[0064] Flame retardant performance: afterflame time 0s, smoldering time 0s, damage length 9.8cm.

[0065] Static contact angle: 136°.

[0066] Water repellency performance is tested according to AATCC-22.

[0067] Flame retardant properties were tested according to GB / T5455—2014 "Vertical Method for Testing the Burning Performance of Textiles".

[0068] The static contact angle of the fabric was measured using a contact angle measuring instrument.

Claims

1. A flame-retardant and waterproof polyurethane emulsion, comprising a mixture of silica sol and organosilicon-modified polyurethane emulsion, wherein the mass ratio of the silica sol to the organosilicon-modified polyurethane emulsion is 1:

3.

2. The flame-retardant and waterproof polyurethane emulsion as described in claim 1, characterized in that: The silica sol is prepared by the following method: The silica sol is made from tetraethyl orthosilicate, phosphorus-containing siloxane, catalyst, water, and emulsifier. First, 15 parts of tetraethyl orthosilicate, 5 parts of phosphorus-containing siloxane, 0.3 parts of AEO-3, 0.4 parts of AEO-9, and 0.5 g of sodium dodecyl sulfate are added to 100 parts of distilled water and emulsified and homogenized by high-speed shearing for 30 min. The mixture is then poured into a reaction vessel, heated to 60°C in a water bath, and ammonia is slowly added dropwise to adjust the pH value to 8-9. After maintaining the temperature for 6 hours, the mixture is cooled to obtain the silica sol.

3. The flame-retardant and waterproof polyurethane emulsion as described in claim 1, characterized in that: The organosilicon-modified polyurethane emulsion is prepared by the following method: 0.4 mol of isophorone diisocyanate was placed in a reactor, stirred, and 0.3 mol of polyethylene glycol (PEG) was added. The temperature was controlled at 75°C, and 3-4 drops of dibutyltin dilaurate were added dropwise. Prepolymerization was carried out for 3 hours. Add 0.05 mol of dimethylolpropionic acid and react for 2 h; Add 0.02 mol of 1,4-butanediol and allow the chain extension reaction to proceed for 2 hours; Add 0.03 mol of dihydroxysiloxane and react for 1 h. Cool the product to 40 °C, add 0.05 mol of triethylamine to neutralize the reaction for 0.5 h, and add distilled water to stir at high speed for 1 h to self-emulsify. The temperature was raised to 40℃, and 0.06 mol of long-chain siloxane was slowly added dropwise. The pH value was adjusted to 8-9 with ammonia water. The reaction was carried out for 4 hours and then cooled to room temperature to obtain organosilicon-modified polyurethane emulsion.

4. The preparation method of the flame-retardant and waterproof polyurethane emulsion according to claim 1, comprising the following steps: Take the silica sol and organosilicon-modified polyurethane emulsion in the specified proportions. The silica sol was slowly added dropwise to the silicone-modified polyurethane emulsion, and stirred and dispersed at 2000 r / min for 40 min to obtain a flame-retardant and waterproof polyurethane emulsion.

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