Acrylate modified polyurethane fluoride-free waterproof agent and preparation method thereof

Abstract

According to the acrylate modified polyurethane fluoride-free waterproof agent and the preparation method thereof, in the polyurethane synthesis process, hydroxyl silicone oil serves as a part of soft segment, the content of silicon in polyurethane is increased, the good waterproof effect is achieved by means of the good hydrophobic performance of the hydroxyl silicone oil, chain extension is conducted through a three-functional-group or multi-functional-group extender, and the waterproof effect is good. And then an acrylic acid crosslinking monomer is used for blocking, double bonds are introduced, and subsequent emulsion polymerization with a functional monomer is carried out. According to the formula and the preparation method of the fluoride-free waterproof agent provided by the invention, the waterproof agent can endow fabrics with excellent waterproof and washable effects.

Description

Technical Field

[0001] The invention belongs to the technical field of fluorine-free waterproofing agent preparation, and specifically relates to an acrylate modified polyurethane fluorine-free waterproofing agent and a preparation method thereof. Background Art

[0002] At present, the waterproofing agent used on fabrics is still fluorine-based waterproofing agents, and C6 and C8 waterproofing agents will decompose perfluorooctanoic acid (PFOA) or perfluorooctane sulfonic acid (PFOS), which are harmful to the ecology. The development of fluorine-free waterproofing agents to replace fluorine-based ones has attracted much attention.

[0003] Waterborne polyurethane is mainly composed of soft segment, hard segment, chain extender, end capping agent and other parts. Among them, the polyurethane soft segment plays a vital role in polyurethane. Soft segment usually refers to low molecular weight raw materials of polyether or polyol, which increase the softness, ductility and elasticity of polyurethane. The molecular weight of the soft segment has an effect on the mechanical properties of polyurethane. The polyester soft segment improves the strength, and the polyether soft segment reduces the strength but improves the elongation. The crystallinity of the soft segment also affects the performance of polyurethane. Crystallinity is conducive to improving performance, but sometimes reduces low-temperature flexibility. In addition, polyether soft segment polyurethane contains ether bonds, which are hydrophilic; polyester polyurethane contains ester bonds, which are not acid- and alkali-resistant. Patent Publication No. CN 114409853A uses PEG to prepare waterborne polyurethane. PEG is a polyether polyol with strong hydrophilicity. It is used to prepare waterproofing agents, which has a negative effect on waterproofing. Summary of the invention

[0004] Purpose of the invention: In view of this, the purpose of the present invention is to provide an acrylate modified polyurethane fluorine-free waterproofing agent and a preparation method thereof, aiming to achieve the preparation of a fluorine-free waterproofing agent, which is environmentally friendly and has low biological toxicity. The water-based polyurethane coating uses water as a solvent, which can reduce or completely avoid the use of organic solvents, so its VOC content is also extremely low, and the water-based polyurethane also has good degradability. It has little impact on environmental pollution. Fabrics treated with it can achieve excellent waterproof and washable effects.

[0005] Technical solution: The acrylate-modified polyurethane fluorine-free waterproofing agent of the present invention comprises the following components in percentage by mass:

[0006] 1-5wt% polyisocyanate;

[0007] 1-5wt% PEG-2000;

[0008] 5-10wt% hydroxy silicone oil;

[0009] 0.4-1wt% chain extender;

[0010] 0.5-1.5wt% acrylic acid crosslinking monomer;

[0011] 0.4-0.8wt% neutralizer;

[0012] 10-20wt% functional monomer;

[0013] 0.1-1 wt% surfactant;

[0014] 0.01-1wt% initiator;

[0015] The balance is pure water.

[0016] Furthermore, as a preferred embodiment, the polyisocyanate is one or a combination of hexamethylene diisocyanate, isophorone diisocyanate, methylcyclohexyl diisocyanate, and dicyclohexylmethane diisocyanate.

[0017] Furthermore, as a preferred embodiment, the chain extender is one or a combination of N-methyldiethanolamine, diethanolamine, triethanolamine, ethylene glycol, 1,2-butanediol, 1,4-butanediol, glycerol, and trimethylolpropane.

[0018] Furthermore, as a preferred embodiment, the acrylic cross-linking monomer is one or a combination of hydroxyethyl acrylate, hydroxypropyl acrylate, and hydroxyethyl methacrylate.

[0019] Furthermore, as a preferred embodiment, the neutralizing agent is one of dilute hydrochloric acid, acetic acid, and citric acid.

[0020] Furthermore, as a preferred embodiment, the functional monomer is one or a combination of lauryl acrylate, octadecyl acrylate, behenyl acrylate, and isodecyl acrylate.

[0021] Further, as a preferred embodiment, the surfactant is one or more of a cationic surfactant and a nonionic surfactant;

[0022] The cationic surfactant is an amine salt, a quaternary ammonium salt, or a combination of the two;

[0023] The nonionic surfactant is one or a combination of high-carbon fatty alcohol polyoxyethylene ether, fatty acid polyoxyethylene, sorbitan ester, and alkylphenol polyoxyethylene ether.

[0024] Furthermore, as a preferred embodiment, the initiator is one of azobisisobutylamidine hydrochloride and persulfate.

[0025] The present invention also provides a method for preparing the above-mentioned acrylate modified polyurethane fluorine-free waterproofing agent, comprising the following steps:

[0026] Step (1): Add PEG, hydroxy silicone oil monomer, and catalyst into a reaction kettle and heat to a reaction temperature of 70-80°C;

[0027] Step (2): adding polyisocyanate and keeping the temperature to react for 1-3 hours;

[0028] Step (3): dissolving the chain extender in a solvent, adding the solution to the reaction system, and keeping the reaction temperature for 0.5-1h;

[0029] Step (4): adding acrylic acid cross-linking monomer and keeping the temperature to react for 1-3 hours;

[0030] Step (5): adding a neutralizing agent and slowly adding pure water to disperse;

[0031] Step (6): stirring and dispersing at a high speed of 1000 rpm to obtain waterborne polyurethane;

[0032] Step (7): taking the waterborne polyurethane prepared in step (6), functional monomers, surfactants, and pure water, and dispersing and emulsifying them to obtain a pre-emulsion;

[0033] Step (8): heating to a reaction temperature of 70-80°C, adding an initiator aqueous solution dropwise, and keeping the temperature for reaction for 4-6 hours;

[0034] Step (9): cooling and filtering to obtain an acrylate-modified polyurethane fluorine-free waterproofing agent.

[0035] Beneficial effects:

[0036] 1. Hydroxy silicone oil monomer is selected in this application scheme. Hydroxy silicone oil has a unique chemical structure and can form hydrogen bonds with fibers. The methyl groups are arranged vertically on the fiber surface to form a hydrophobic layer on the fiber surface to repel water. Hydroxy silicone oil is used as part of the soft segment, and the content of silicon in polyurethane is increased. Its good hydrophobic properties are utilized to achieve a good waterproof effect.

[0037] 2. This scheme uses trimethylolpropane as a chain extender to increase the number of polyurethane branches and form a multi-branched structure, which subsequently forms a network copolymer with large steric hindrance. It is then capped with an acrylic cross-linking monomer to introduce double bonds for subsequent emulsion polymerization with functional monomers, further improving the water-repellent properties of the compound. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 This is the infrared spectrum of the product obtained in Example 3;

[0039] Figure 2 This is a comparison chart of waterproof performance standards. DETAILED DESCRIPTION

[0040] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0041] Unless otherwise specified, the reagents and raw materials used in the examples and comparative examples of the present invention were purchased from the market.

[0042] Example 1

[0043] Take 50g of hydroxy silicone oil, 25g of PEG-2000, drop 0.02g of dibutyltin dilaurate, stir and heat to 70°C, add 33.3g of isophorone diisocyanate, keep warm for 1h; add N-methyldiethanolamine (dissolved in an appropriate amount of solvent)

[0044] N-methylpyrrolidone) 8.9g, keep warm for 0.5h; then add 9.75g of hydroxyethyl methacrylate, keep warm for 1h; add glacial acetic acid to neutralize to pH 6-7, add 296g of pure water at 1000 rpm and high-speed shear force, disperse for 0.5h to obtain water-based polyurethane emulsion WPU.

[0045] Take 120g of the above WPU, add 30g of octadecyl acrylate, 20g of isodecyl acrylate, 1.3g of octadecyl trimethyl ammonium bromide, 1.3g of AOE-9, 1.3g of Tween-60, and 86g of pure water, and disperse at 1000 rpm to obtain a prepolymer emulsion, heat and stir the pre-emulsion to 75°C, drop 0.4g of azobisisobutylamidine hydrochloride and 40g of pure water, and keep the temperature for 6h. After the reaction is completed, cool to room temperature and filter with a 200-mesh filter to obtain a fluorine-free waterproofing agent.

[0046] Example 2

[0047] Take 65.62g of hydroxy silicone oil, 9.38g of PEG-2000, drop 0.02g of dibutyltin dilaurate, stir and heat to 70°C, add 33.3g of isophorone diisocyanate, and keep warm for 1h; add 8.9g of N-methyldiethanolamine (dissolved in an appropriate amount of solvent N-methylpyrrolidone), and keep warm for 0.5h; then add 9.75g of hydroxyethyl methacrylate, and keep warm for 1h; add glacial acetic acid to neutralize to pH 6-7, add 296g of pure water at 1000 rpm and high-speed shear force, disperse for 0.5h, and obtain water-based polyurethane emulsion WPU.

[0048] Take 120g of the above WPU, add 30g of octadecyl acrylate, 20g of isodecyl acrylate, 1.3g of octadecyltrimethylammonium bromide, 1.3g of AOE-9, 1.3g of Tween-60, and 86g of pure water, and disperse at a high speed of 1000 rpm to obtain a prepolymer emulsion, heat and stir the pre-emulsion to 75°C, add a mixture of 0.4g of azobisisobutylamidine hydrochloride and 40g of pure water, and keep warm for reaction for 6h; after the reaction is completed, cool to room temperature and filter with a 200-mesh filter to obtain a fluorine-free waterproofing agent.

[0049] Example 3

[0050] Take 65.62g of hydroxy silicone oil, 9.38g of PEG-2000, drop 0.02 dibutyltin dilaurate, stir and heat to 70℃, add 33.3g of isophorone diisocyanate, and keep warm for 1h. Add 3.35g of trimethylolpropane and 5.95g of N-methyldiethanolamine (dissolved in an appropriate amount of solvent N-methylpyrrolidone), keep warm for 0.5h; then add 9.75g of hydroxyethyl methacrylate, keep warm for 1h; add glacial acetic acid to neutralize to pH 6-7, add 296g of pure water at 1000 rpm and high-speed shear force, disperse for 0.5h, and obtain waterborne polyurethane emulsion WPU.

[0051] Take 120g of the above WPU, add 30g of octadecyl acrylate, 20g of isodecyl acrylate, 1.3g of octadecyltrimethylammonium bromide, 1.3g of AOE-9, 1.3g of Tween-60, and 86g of pure water, and disperse at a high speed of 1000 rpm to obtain a prepolymer emulsion, heat and stir the pre-emulsion to 75°C, add a mixture of 0.4g of azobisisobutylamidine hydrochloride and 40g of pure water, and keep warm for reaction for 6h; after the reaction is completed, cool to room temperature and filter with a 200-mesh filter to obtain a fluorine-free waterproofing agent.

[0052] Figure 1 The infrared spectrum of the fluorine-free waterproofing agent product obtained in this example shows that the characteristic peak of the infrared spectrum is: -1 The peaks on the left and right are the stretching vibration peaks of NH and -NH in carbamate, 2888 cm -1 The left and right absorption peaks are -CH 2 -Stretching vibration peak; 2079cm -1 The left and right absorption peaks are the stretching vibration peaks of Si-C; 1727cm -1 Nearby is the stretching vibration absorption peak of carbonyl C=O in carbamate, 662cm -1 It is the absorption peak of the out-of-plane bending vibration of CH in the olefin RCH=CHR structure. The peak position assignment proves that the polymer is successfully synthesized.

[0053] Comparative Example 1:

[0054] Take 81g of PEG-2000 after vacuum dehydration and 12g of isophorone diisocyanate and add them into a glass flask. 2 protection, heated to 76-78°C, reacted for 2h, added 1.3g of chain extender N-methyldiethanolamine (dissolved in an appropriate amount of solvent N-methylpyrrolidone), dropped 0.06g of catalyst dibutyltin dilaurate, reacted for 0.5h, added 5.6g of cross-linking monomer hydroxyethyl acrylate, reacted for 1h, discharged, added acetic acid to neutralize to pH 7-8, and finally added 230g of deionized water at 1000 rpm under high shear force to obtain a water-based acrylic polyurethane emulsion;

[0055] Take 130g of the above aqueous acrylic polyurethane emulsion, add 0.86g of hexadecyltrimethylammonium bromide, AEO-9

[0056] 0.75g, 0.65g of 1308 were stirred and dissolved, nitrogen was passed through, the temperature was raised to 60℃, 10g of dodecyl acrylate, 13g of methyl acrylate, 60g of deionized water were added, the mixture was stirred rapidly at 250 rpm, 0.3g of initiator V500 was added, the temperature was raised to 66℃, the reaction was continued for 3h, the temperature was raised to 72℃ and the temperature was kept for 3h. The temperature was lowered to 40-60℃ and filtered to obtain the fluorine-free waterproofing agent.

[0057] Effect verification:

[0058] The waterproofing effect of the fluorine-free waterproofing agent prepared in Examples 1-3 and Comparative Example 1 is verified as follows:

[0059] 1. Spray waterproof test

[0060] The spray water test is carried out according to AATCC-22. The water resistance level is used to indicate the spray resistance. The evaluation criteria are shown in Table 1 and Figure 2 ;

[0061] Table 1: Spray water resistance test standard table

[0062] Waterproof grade Evaluation Criteria Level 1 The entire surface is wetted Level 2 The surface is semi-wet Level 3 Only small, discontinuous areas of wetness on the surface Level 4 The surface is not wet, but there are water droplets on the surface Level 5 The surface is not wetted and there are no water drops on the surface

[0063] Sample preparation method: dilute the waterproofing agent prepared in Examples 1-3 and Comparative Example 1 with water to 40 g / L, treat the fabric with a dip-and-roll process, and bake at a temperature of 120-180° C. for 1-3 min.

[0064] Waterproof test method: Cut 18*18cm of finished fabric and stretch it on the clamp and place it at an angle of 45°. Set a nozzle 150mm above it and quickly sprinkle 250mL of water on the inclined fabric within 25-30s. After the spraying is completed, take out the clamp and knock it horizontally twice with the front side downward to observe the experimental wetting process, then use text description and compare with standard pictures to evaluate its level, and take the average of the two times.

[0065] Test data:

[0066] Table 2 shows the spray waterproof test results

[0067] serial number Waterproof performance before washing Waterproof after 10 washes Waterproof after 20 washes Example 1 80 80 75 Example 2 90 90 85 Example 3 90 90 90 Comparative Example 1 70 60 45

[0068] From the results in Table 2 and the implementation scheme, it can be seen that in Example 1, in the synthesis of water-based polyurethane, hydroxy silicone oil is selected as part of the soft segment to synthesize water-based polyurethane, the silicon accounts for 39.38%, and the synthetic fluorine-free waterproof agent is used to treat the fabric. In the spray test, the waterproof grade reaches level 3, and after washing 10-20 times, it still has good waterproof performance; in Example 2, the silicon content in the polyurethane is 51.69%, and the synthetic fluorine-free waterproof agent is used to treat the fabric. In the spray test, the waterproof grade reaches level 4, and after washing 10-20 times, it still has good waterproof performance. Good waterproof performance; Example 3, the silicon content in the polyurethane is 51.69%, and the trifunctional chain extender is used for chain extension and cross-linking to synthesize a fluorine-free waterproof agent to treat the fabric. In the spray test, the waterproof level reaches level 4, and after washing 10-20 times, the waterproof level can still reach level 4; Comparative Example 1, PEG-2000 is used as the soft segment in the polyurethane, and functional monomers such as dodecyl acrylate and methyl acrylate are introduced in the emulsion polymerization to treat the fabric. In the spray test, the waterproof level fails to reach level 3, and after washing, the waterproof performance is significantly attenuated.

[0069] The introduction of hydroxy silicone oil as part of the soft segment of polyurethane has a positive effect on the waterproof performance of the waterproof agent. Within a certain range, the proportion of silicon in polyurethane increases, and the waterproof performance is significantly improved. When synthesizing polyurethane, the performance of the waterproof agent can be further improved by using a trifunctional chain extender for chain extension and cross-linking.

[0070] The above is only an implementation method of the invention, and does not limit the scope of patent protection. Those skilled in the art can make non-substantial changes or substitutions based on the invention, which still fall within the scope of patent protection.

Claims

1. An acrylate modified polyurethane fluorine-free waterproofing agent, characterized in that The following components are included in mass percentage: 1-5wt% polyisocyanate; 1-5wt% PEG-2000; 5-10wt% hydroxy silicone oil; 0.4-1wt% chain extender; 0.5-1.5wt% acrylic acid crosslinking monomer; 0.4-0.8wt% neutralizer; 10-20wt% functional monomer; 0.1-1 wt% surfactant; 0.01-1wt% initiator; The balance is pure water.

2. The acrylate-modified polyurethane fluorine-free waterproofing agent according to claim 1, characterized in that: The polyisocyanate is one or a combination of 1,6-hexamethylene diisocyanate, isophorone diisocyanate, methylcyclohexyl diisocyanate and dicyclohexylmethane diisocyanate.

3. The acrylate-modified polyurethane fluorine-free waterproofing agent according to claim 1, characterized in that: The chain extender is one or a combination of N-methyldiethanolamine, diethanolamine, triethanolamine, ethylene glycol, 1,2-butanediol, 1,4-butanediol, glycerol, and trimethylolpropane.

4. The acrylate-modified polyurethane fluorine-free waterproofing agent according to claim 1, characterized in that: The acrylic acid cross-linking monomer is one or a combination of hydroxyethyl acrylate, hydroxypropyl acrylate and hydroxyethyl methacrylate.

5. The acrylate-modified polyurethane fluorine-free waterproofing agent according to claim 1, characterized in that: The neutralizing agent is one of dilute hydrochloric acid, acetic acid and citric acid.

6. The acrylate-modified polyurethane fluorine-free waterproofing agent according to claim 1, characterized in that: The functional monomer is one or a combination of lauryl acrylate, octadecyl acrylate, behenyl acrylate and isodecyl acrylate.

7. The acrylate-modified polyurethane fluorine-free waterproofing agent according to claim 1, characterized in that: The surfactant is one or more of a cationic surfactant and a nonionic surfactant; The cationic surfactant is an amine salt, a quaternary ammonium salt, or a combination of the two; The nonionic surfactant is one or a combination of high-carbon fatty alcohol polyoxyethylene ether, fatty acid polyoxyethylene, sorbitan ester, and alkylphenol polyoxyethylene ether.

8. The acrylate-modified polyurethane fluorine-free waterproofing agent according to claim 1, characterized in that: The initiator is one of azobisisobutyramidine hydrochloride and persulfate.

9. A method for preparing the acrylate modified polyurethane fluorine-free waterproofing agent according to any one of claims 1 to 8, characterized in that The steps include: Step (1): Add PEG, hydroxy silicone oil monomer, and catalyst into a reaction kettle and heat to a reaction temperature of 70-80°C; Step (2): adding polyisocyanate and keeping the temperature to react for 1-3 hours; Step (3): dissolving the chain extender in a solvent, adding the solution to the reaction system, and keeping the reaction temperature for 0.5-1h; Step (4): adding acrylic acid cross-linking monomer and keeping the temperature to react for 1-3 hours; Step (5): adding a neutralizing agent and slowly adding pure water to disperse; Step (6): stirring and dispersing at a high speed of 1000 rpm to obtain waterborne polyurethane; Step (7): taking the waterborne polyurethane prepared in step (6), functional monomers, surfactants, and pure water, and dispersing and emulsifying them to obtain a pre-emulsion; Step (8): heating to a reaction temperature of 70-80°C, adding an initiator aqueous solution dropwise, and keeping the temperature for reaction for 4-6 hours; Step (9): cooling and filtering to obtain an acrylate-modified polyurethane fluorine-free waterproofing agent.

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