Fluoride-free waterproof agent for fabric and preparation method thereof

Abstract

The invention relates to the technical field of waterproof agents for fabrics, and particularly discloses a fluoride-free waterproof agent for fabrics and a preparation method of the fluoride-free waterproof agent. The preparation method specifically comprises the following steps: dehydrating polyol / ester, adding isocyanate, heating to 80-90 DEG C, reacting for 2-3 hours, cooling, dropwise adding a chain extender, reacting for 0.5-1 hour at 45-48 DEG C, adding POSS, stirring for 1-2 hours at 45-48 DEG C, adding an acrylic monomer A for blocking, cooling, dropwise adding acid, stirring and neutralizing to obtain a prepolymer; pouring the prepolymer into water, stirring and emulsifying to obtain a POSS-PU emulsion; quickly stirring the POSS-PU emulsion, an acrylic monomer B, an emulsifier, water, a co-emulsifier, a pH regulator and the like to obtain a composite emulsion; homogenizing the composite emulsion until the composite emulsion has obvious blue light; and adding dodecanethiol and an azo amidine initiator, reacting at 68-70 DEG C for 3-7 hours, cooling, filtering and taking out to obtain the fluoride-free waterproof agent.

Description

Technical Field

[0001] The present invention relates to the technical field of fabric waterproofing agents, and specifically discloses a fluorine-free waterproofing agent for fabrics and a preparation method thereof. Background Art

[0002] In the prior art, fluorine-free waterproofing agents are mainly divided into three categories: acrylate, polyurethane, and silicone. Fabrics treated with silicone waterproofing agents have a soft hand feeling, but their waterproof performance does not meet market demands; polyurethane waterproofing agents have relatively balanced performance, but their preparation process is complex and the cost is high; acrylate waterproofing agents have a simple preparation process and low cost, so they have been widely used in the textile field. However, it has been found in use that there is still great room for improvement in the hand feeling, waterproofness, and wash resistance of fabrics treated with acrylate waterproofing agents. Therefore, it is of great significance to study a fluorine-free waterproofing agent for fabrics and a preparation method thereof that combines the advantages of acrylate, polyurethane, and silicone waterproofing agents. Summary of the Invention

[0003] The purpose of the present invention is to provide a fluorine-free waterproofing agent for fabrics and a preparation method thereof to solve the problems raised in the prior art.

[0004] To achieve the above purpose, the present invention provides the following technical solution: A preparation method of a fluorine-free waterproofing agent for fabrics, comprising the following steps: S1: Add polyol / ester to a reaction kettle, at 110 - 120 °C, -0.1 MPa, dehydrate for 1 - 2 h; cool down to 40 - 50 °C, add isocyanate, ensure that the R value is between 3 and 4, raise the temperature to 80 - 90 °C and react for 2 - 3 h, cool down to 30 °C, dropwise add a chain extender, and react at 45 - 48 °C for 0.5 - 1 h to obtain a reactant system, ensuring that the r1 value is between 1.2 and 2.5;

[0005] S2: Add POSS to the reactant system, stir at 45 - 48 °C for 1 - 2 h, add acrylic monomer A, carry out capping at 60 - 70 °C for 1 - 3 h, and the capping rate is 102 - 105%; cool down to 45 °C, dropwise add an acid (the acid is one of glacial acetic acid, phosphoric acid, hydrochloric acid, and sulfuric acid), stir and neutralize to obtain a prepolymer, and the neutralization degree is 100 - 140%; pour the prepolymer into water at 40 - 50 °C, stir at 1000 - 3000 rpm, and emulsify to form a POSS-PU emulsion with a solid content of 30%;

[0006] S3: Add the POSS-PU emulsion, acrylic monomer B, emulsifier, water, co-emulsifier, pH regulator, etc. to a reaction kettle, stir rapidly at 55 - 60 °C for 1 - 2 h to obtain a composite emulsion with a solid content of 20 - 25% and a pH of 3 - 4;

[0007] S4: Pour the composite emulsion into a homogenizer, and homogenize it at 10 - 20 MPa for 4 times until obvious blue light appears; add dodecyl mercaptan and azoamidine initiator, react at 68 - 70 °C for 3 - 7 h, cool to 30 - 40 °C, filter and take out to obtain a fluorine-free water repellent.

[0008] More preferably, the polyol / ester includes at least one of polytetrahydrofuran diol (Mn = 1000 - 2000), polypropylene glycol (Mn = 800 - 2000), polycaprolactone (Mn = 1000 - 2000), polyethylene glycol (Mn = 500 - 1500), methoxypolyethylene glycol (Mn = 500 - 1000), polycarbonate (Mn = 1000 - 2000), hyperbranched polyester (Mn = 1000 - 3000), etc.; the isocyanate is at least one of IPDI, TDI, MDI, HDI, HMDI; the chain extender is a cationic chain extender for polyurethane such as N-methyldiethanolamine and triethanolamine; the POSS includes at least one of heptaoctyl methacryloxypropyl POSS, heptaisobutyl methacryloxypropyl POSS, quaternary ammonium base POSS, dihydroxy POSS, and amino POSS; the acrylic monomer A includes at least one of acrylic acid, hydroxyethyl acrylate, and hydroxyethyl methacrylate; the acrylic monomer B includes at least three of octadecyl acrylate, docosyl acrylate, methyl acrylate, methyl methacrylate, isobornyl acrylate, isobornyl methacrylate, cyclohexyl acrylate, cyclohexyl methacrylate, isooctyl acrylate, isooctyl methacrylate, hydroxyethyl acrylate, and hydroxyethyl methacrylate; the emulsifier is two or more of Span80, Span60, Tween60, AEO9, TX100, CTAB, STAC, APEG1000, TO8, and TO3, the co-emulsifier is TPG and PM, and the pH regulator is glacial acetic acid.

[0009] More preferably, the addition amount of the POSS is 5 - 40% of the mass of the reactant system;

[0010] In the composite emulsion, the POSS-PU emulsion accounts for 2 - 2.5% of the total mass; the emulsifier accounts for 0.5 - 1% of the total; the co-emulsifier accounts for 1 - 2% of the total; the acrylic monomer B accounts for 15 - 25% of the total; the rest is water;

[0011] In the fluorine-free water repellent, dodecyl mercaptan accounts for 0.15 - 1% of the mass of the acrylic monomer B; the azoamidine initiator accounts for 0.3 - 1% of the mass of the acrylic monomer B.

[0012] More preferably, the addition amount of the POSS is 5 - 15% of the mass of the reactant system.

[0013] Preferably, the POSS is heptaoctyl methacryloxypropyl POSS, and its preparation method comprises the following steps: Under the protection of nitrogen, water and anhydrous methanol are mixed, heated to 30-40 °C, the pH is adjusted to 2-3, and a mixed solution of octyltriethoxysilane and 3-(methacryloyloxy)propyltrimethoxysilane is added dropwise, and the reaction is carried out at a constant temperature for 1-5 days to obtain a turbid white solution, which is allowed to stand and separated into layers, and the transparent organic layer is separated, dissolved in hexane, washed with water until neutral, the colorless and transparent organic layer is separated, and finally hexane is removed by reduced pressure pumping and the residual moisture is removed to obtain heptaoctyl methacryloxypropyl POSS.

[0014] Preferably, in the mixed solution of octyltriethoxysilane and 3-(methacryloyloxy)propyltrimethoxysilane, the molar ratio of octyltriethoxysilane to 3-(methacryloyloxy)propyltrimethoxysilane is 7:1; the molar ratio of water to the above mixed solution is 3:1, and the addition amount of anhydrous ethanol is 85% of the total mass of water and anhydrous methanol.

[0015] Preferably, modified lignin is further added in step S1, and the addition amount is 5-8% of the mass of polyol / ester; specifically, it comprises the following steps: S1: Add polyol / ester and modified lignin to the reaction kettle, dehydrate at 110-120 °C for 1-2 h; cool down to 40-50 °C, add isocyanate to ensure that the R value is 3-4, raise the temperature to 80-90 °C and react for 2-3 h, cool down to 30 °C, add chain extender dropwise, and react at 45-48 °C for 0.5-1 h to obtain a reactant system, ensuring that the r1 value is 1.2-2.5.

[0016] Preferably, the preparation of the modified lignin comprises the following steps, by mass: Step 1: Dissolve enzymatically hydrolyzed lignin in a mixed solution of NaOH solution and ethanol (the volume ratio of 1 mol / L NaOH aqueous solution to ethanol is 1:1), add allyl bromide, stir at 55-60 °C for 24-25 h, and perform post-treatment (cool to room temperature, add an equal mass of ice-water mixture, adjust the pH to 3, stand overnight, filter to obtain the solid, dry and crush) to obtain allylated lignin;

[0017] Step 2: Mix hydroxyrosin acid, bromobenzenethiol, sodium carbonate and tetrahydrofuran evenly, react at 50-60 °C for 3-5 h, and remove the solvent to obtain modified rosin acid;

[0018] Step 3: Add allylated lignin to tetrahydrofuran, stir evenly, add mercaptoethanol and modified rosin acid, react at 60-65 °C for 24-25 h, and remove the solvent to obtain modified lignin.

[0019] Preferably, the allylated lignin comprises the following raw materials in parts by mass: 10-15 parts of enzymatically hydrolyzed lignin, 8-10 parts of allyl bromide; in the modified rosin acid, the molar ratio of hydroxy rosin acid, bromophenyl mercaptan, and sodium carbonate is (1-1.2):1:1; the modified lignin comprises the following raw materials in parts by mass: 10-15 parts of allylated lignin, 4-5 parts of mercaptoethanol, 25-30 parts of modified rosin acid.

[0020] Compared with the prior art, the beneficial effects achieved by the present invention are as follows: (1) After introducing octyl methacryloxypropyl POSS into polyurethane to prepare a polyurethane emulsion, and then copolymerizing with acrylic monomers, a POSS-PU-PA waterproofing agent is formed. Among them, POSS is a nano monomer with a three-dimensional structure, having a highly symmetric and thermally stable internal structure. The external reactive groups make POSS more easily dispersed when added as a filler, which is beneficial to the formation of a uniform lotus leaf papilla-like microstructure on the surface of fibers, yarns, and fabrics after the POSS-PU-PA waterproofing agent forms a film, and can significantly improve the hydrophobicity of the waterproofing agent. This waterproofing agent has the advantages of soft handfeel, good initial waterproof performance, improved tear strength, and good washability.

[0021] (2) Further introducing modified lignin, lignin itself contains multiple active groups, and after introduction, it can increase the crosslinking degree of the polyurethane emulsion, improving mechanical properties and waterproofness; in the present invention, lignin is modified by first introducing double bonds and then reacting with mercaptoethanol and mercapto-containing modified rosin acid, replacing some of the low-reactivity phenolic hydroxyl groups in lignin with highly reactive primary alcohol hydroxyl groups, which helps the reaction proceed and also introduces a rosin acid structure with good hydrophobicity, further improving waterproofness; the addition amount of modified lignin should not be too much. On the one hand, excessive crosslinking degree will lead to a decrease in properties such as processability, and on the other hand, lignin itself has a relatively dark color, and too much addition will cause a change in the color of the waterproofing agent, resulting in adverse effects; the addition ratios of mercaptoethanol and modified rosin acid also need to be controlled. If the addition amount of mercaptoethanol is small, the number of highly reactive primary alcohol hydroxyl groups available for reaction is small, resulting in a decrease in crosslinking degree, and if the addition amount is large, it will lead to a decrease in hydrophobicity. Description of the Drawings

[0022] Figure 1 It is a transmission electron micrograph of octyl methacryloxypropyl POSS. Detailed Embodiments

[0023] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0024] Unless otherwise specified, the following parts are parts by mass;

[0025] Example 1: S1: Add PE3556 and PEG1000 with a molar ratio of 1:1 to the reaction kettle, dehydrate at 115 °C for 1.5 h; cool down to 45 °C, add isophorone diisocyanate, ensure that the R value is 3.5, raise the temperature to 88 °C and react for 2 h, cool down to 30 °C, and dropwise add N-methyldiethanolamine as a chain extender. After 30 min of dropping, react at 45 °C for 0.8 h to obtain a reactant system, ensuring that the r1 value is 1.65;

[0026] S2: Under the protection of nitrogen, mix water and anhydrous methanol, heat up to 40 °C, adjust the pH to 3 with hydrochloric acid, and dropwise add a mixed solution of octyltriethoxysilane and 3-(methacryloyloxy)propyltrimethoxysilane with a molar ratio of 7:1. After the mixed solution is completely dropped, the system slowly becomes turbid and white. Keep reacting at 40 °C for 5 days to obtain a turbid white solution. Place it in a separating funnel and let it stand for stratification. Separate the transparent organic layer, dissolve the organic layer with hexane, wash it with water until neutral, separate the colorless and transparent organic layer with a separating funnel, finally remove hexane by vacuum pumping, and remove the residual moisture with CaCl2 to obtain a colorless, transparent and oily liquid with a certain viscosity, which is octaoctyl methacryloyloxypropyl POSS;

[0027] S3: Add 10% by mass of octaoctyl methacryloyloxypropyl POSS based on the mass of the reactant system to the reactant system, stir at 45 °C for 1 h, add hydroxyethyl acrylate to block the residual NCO, and carry out capping at 65 °C for 2 h, with a capping rate of 102%; cool down to 45 °C, dropwise add glacial acetic acid, and stir for 0.5 h for neutralization to obtain a prepolymer, with a neutralization degree of 110%; pour the prepolymer into water at 45 °C, stir, and form a POSS-PU emulsion with a solid content of 30% after emulsification;

[0028] S4: Add the POSS-PU emulsion, octadecyl ester, docosyl ester, isobornyl methacrylate, AEO9, STAC, water, TPG, and glacial acetic acid to the reaction kettle, and stir rapidly at 60 °C for 1 h to obtain a composite emulsion with a solid content of 25% and a pH of 4;

[0029] The POSS-PU emulsion accounts for 2.2% of the mass of the composite emulsion; octadecyl ester, docosyl ester, and isobornyl methacrylate are acrylic monomer B, and acrylic monomer B accounts for 20% of the mass of the composite emulsion. The mass ratio of octadecyl ester, docosyl ester, and isobornyl methacrylate is 5:1:0.5; AEO9 and STAC are emulsifiers, and the emulsifiers account for 0.8% of the mass of the composite emulsion. The mass ratio of AEO9 to STAC is 1:1; TPG is a co-emulsifier, and the co-emulsifier accounts for 2% of the mass of the composite emulsion; the rest is water;

[0030] S5: Pour the composite emulsion into a homogenizer, and homogenize it at 15 MPa for 4 times until obvious blue light appears; add dodecyl mercaptan accounting for 0.25% of the mass of acrylic monomer B and azoamidine initiator accounting for 0.5% of the mass of acrylic monomer B, react at 70 °C for 3 h, cool to 35 °C, filter and take out to obtain a fluorine-free water repellent.

[0031] Example 2: S1: Add PE3556 and PEG1000 with a molar ratio of 1:1 and modified lignin accounting for 6% of the mass of polyol / ester into a reaction kettle, dehydrate at 115 °C for 1.5 h; cool down to 45 °C, add isophorone diisocyanate, ensure the R value is 3.5, raise the temperature to 88 °C and react for 2 h, cool down to 30 °C, dropwise add N-methyldiethanolamine as a chain extender, after dropping for 30 min, react at 45 °C for 0.8 h to obtain a reactant system, and ensure the r1 value is 1.65;

[0032] S2: Under the protection of nitrogen, mix water and anhydrous methanol, heat up to 40 °C, adjust the pH to 3 with hydrochloric acid, dropwise add a mixed solution of octyltriethoxysilane and 3-(methacryloyloxy)propyltrimethoxysilane with a molar ratio of 7:1. After the mixed solution is completely dropped, the system slowly becomes turbid and white. Keep reacting at 40 °C for 5 days to obtain a turbid white solution. Place it in a separatory funnel and let it stand for stratification. Separate the transparent organic layer, dissolve the organic layer with hexane, wash it with water until neutral, separate the colorless and transparent organic layer with a separatory funnel, finally remove hexane by reduced pressure pumping, and remove residual moisture with CaCl2 to obtain a colorless, transparent and oily liquid with a certain viscosity, which is octylmethylacryloyloxypropyl POSS;

[0033] S3: Add octylmethylacryloyloxypropyl POSS accounting for 10% of the mass of the reactant system to the reactant system, stir at 45 °C for 1 h, add hydroxyethyl acrylate to block the residual NCO, and carry out end-capping at 65 °C for 2 h, with an end-capping rate of 102%; cool down to 45 °C, dropwise add glacial acetic acid, stir for 0.5 h for neutralization to obtain a prepolymer, with a neutralization degree of 110%; pour the prepolymer into water at 45 °C, stir, and form a POSS-PU emulsion with a solid content of 30% after emulsification;

[0034] S4: Add POSS-PU emulsion, octadecyl ester, docosyl ester, isobornyl methacrylate, AEO9, STAC, water, TPG, and glacial acetic acid to the reaction kettle, and stir rapidly at 60 °C for 1 h to obtain a composite emulsion with a solid content of 25% and a pH of 4;

[0035] The POSS-PU emulsion accounts for 2.2% of the mass of the composite emulsion; octadecyl stearate, docosyl stearate, and isobornyl methacrylate are acrylic monomer B, and acrylic monomer B accounts for 20% of the mass of the composite emulsion. The mass ratio of octadecyl stearate, docosyl stearate, and isobornyl methacrylate is 5:1:0.5; AEO9 and STAC are emulsifiers, and the emulsifiers account for 0.8% of the mass of the composite emulsion. The mass ratio of AEO9 to STAC is 1:1; TPG is a co-emulsifier, and the co-emulsifier accounts for 2% of the mass of the composite emulsion; the rest is water;

[0036] S5: Pour the composite emulsion into a homogenizer and homogenize it 4 times at 15 MPa until obvious blue light appears; add dodecyl mercaptan accounting for 0.25% of the mass of acrylic monomer B and azoamidine initiator accounting for 0.5% of the mass of acrylic monomer B, and react at 70 °C for 3 h. Cool to 35 °C, filter and take out to obtain a fluorine-free water repellent;

[0037] The preparation of modified lignin includes the following steps: Step 1: Dissolve 12 parts of enzymatically hydrolyzed lignin in a mixed solution 10 times its mass, add 10 parts of allyl bromide, stir at 60 °C for 24 h, and perform post-treatment to obtain allylated lignin;

[0038] Step 2: Take 12-hydroxyabietic acid, 4-bromobenzenethiol, and sodium carbonate with a molar ratio of 1:1:1, add them to tetrahydrofuran and mix evenly, react at 60 °C for 5 h, and remove the solvent to obtain modified abietic acid; the addition amount of the tetrahydrofuran is 10 times the total mass of 12-hydroxyabietic acid, 4-bromobenzenethiol, and sodium carbonate;

[0039] Step 3: Take 12 parts of allylated lignin, add it to 10 times its mass of tetrahydrofuran and stir evenly, add 5 parts of mercaptoethanol and 30 parts of modified abietic acid, react at 65 °C for 24 h, and remove the solvent to obtain modified lignin.

[0040] Example 3: S1: Add PE3556 and PEG1000 with a molar ratio of 1:1 and modified lignin accounting for 6% of the mass of polyol / ester to a reaction kettle, dehydrate at 115 °C for 1.5 h; cool to 45 °C, add isophorone diisocyanate, ensure that the R value is 3.5, raise the temperature to 88 °C and react for 2 h, cool to 30 °C, and dropwise add N-methyldiethanolamine as a chain extender. After dropping for 30 min, react at 45 °C for 0.8 h to obtain a reactant system, ensuring that the r1 value is 1.65;

[0041] S2: Under the protection of nitrogen, mix water and anhydrous methanol, heat up to 40 °C, adjust the pH to 3 with hydrochloric acid, and dropwise add a mixed solution of octyltriethoxysilane and 3-(methacryloyloxy)propyltrimethoxysilane with a molar ratio of 7:1. After the dropwise addition of the mixed solution is completed, the system gradually becomes turbid and white. Keep reacting at 40 °C for 5 days to obtain a turbid white solution. Place it in a separatory funnel and let it stand for layering. Separate the transparent organic layer, dissolve the organic layer with hexane, wash it with water until neutral, separate the colorless and transparent organic layer with a separatory funnel, and finally remove hexane by vacuum pumping and remove the residual moisture with CaCl2 to obtain a colorless, transparent and viscous oily liquid, which is octakis(octyl methacryloyloxypropyl)POSS;

[0042] S3: Add octakis(octyl methacryloyloxypropyl)POSS accounting for 10% of the mass of the reactant system to the reactant system, stir at 45 °C for 1 h, add hydroxyethyl acrylate to block the residual NCO, and carry out capping at 65 °C for 2 h, with a capping rate of 102%; cool down to 45 °C, dropwise add glacial acetic acid, stir for 0.5 h for neutralization to obtain a prepolymer, with a neutralization degree of 110%; pour the prepolymer into water at 45 °C, stir, and form a POSS-PU emulsion with a solid content of 30% after emulsification;

[0043] S4: Add the POSS-PU emulsion, octadecyl stearate, docosyl stearate, isobornyl methacrylate, AEO9, STAC, water, TPG, and glacial acetic acid to the reaction kettle, and stir rapidly at 60 °C for 1 h to obtain a composite emulsion with a solid content of 25% and a pH of 4;

[0044] The POSS-PU emulsion accounts for 2.2% of the mass of the composite emulsion; octadecyl stearate, docosyl stearate, and isobornyl methacrylate are acrylic monomer B, and acrylic monomer B accounts for 20% of the mass of the composite emulsion. The mass ratio of octadecyl stearate, docosyl stearate, and isobornyl methacrylate is 5:1:0.5; AEO9 and STAC are emulsifiers, and the emulsifiers account for 0.8% of the mass of the composite emulsion. The mass ratio of AEO9 to STAC is 1:1; TPG is a co-emulsifier, and the co-emulsifier accounts for 2% of the mass of the composite emulsion; the rest is water;

[0045] S5: Pour the composite emulsion into a homogenizer, homogenize it at 15 MPa for 4 times until there is obvious blue light; add dodecyl mercaptan accounting for 0.25% of the mass of acrylic monomer B and azoamidine initiator accounting for 0.5% of the mass of acrylic monomer B, react at 70 °C for 3 h, cool down to 35 °C, filter and take out to obtain a fluorine-free water repellent;

[0046] The preparation of modified lignin includes the following steps: Step 1: Dissolve 15 parts of enzymatically hydrolyzed lignin in a mixed solution 12 times its mass, add 10 parts of allyl bromide, stir at 60 °C for 24 h, and carry out post-treatment to obtain allylated lignin;

[0047] Step 2: Mix 12-hydroxyl rosin acid, 4-bromobenzenethiol, sodium carbonate, and tetrahydrofuran in a molar ratio of 1:1:1 evenly, react at 60 °C for 5 h, remove the solvent to obtain modified rosin acid; the addition amount of tetrahydrofuran is 10 times the total mass of 12-hydroxyl rosin acid, 4-bromobenzenethiol, and sodium carbonate;

[0048] Step 3: Take 10 parts of allylated lignin, add it to 10 times its mass of tetrahydrofuran and stir evenly, add 4 parts of mercaptoethanol and 25 parts of modified rosin acid, react at 65 °C for 24 h, remove the solvent to obtain modified lignin.

[0049] Comparative Example 1 (without adding POSS-PU emulsion, and the rest of the method steps are the same as those in Example 1): S1: Add octadecyl ester, docosyl ester, isobornyl methacrylate, AEO9, STAC, water, TPG, and glacial acetic acid to the reaction kettle, stir rapidly at 60 °C for 1 h to obtain a composite emulsion with a solid content of 25% and a pH of 4;

[0050] Octadecyl ester, docosyl ester, and isobornyl methacrylate are acrylic monomer B, and acrylic monomer B accounts for 20% of the mass of the composite emulsion. The mass ratio of octadecyl ester, docosyl ester, and isobornyl methacrylate is 5:1:0.5; AEO9 and STAC are emulsifiers, and the emulsifiers account for 0.8% of the mass of the composite emulsion. The mass ratio of AEO9 to STAC is 1:1; TPG is a co-emulsifier, and the co-emulsifier accounts for 2% of the mass of the composite emulsion; the rest is water;

[0051] S2: Pour the composite emulsion into a homogenizer, homogenize at 15 MPa for 4 times until there is obvious blue light; add 0.25% of dodecyl mercaptan based on the mass of acrylic monomer B and 0.5% of azoamidine initiator based on the mass of acrylic monomer B, react at 70 °C for 3 h, cool to 35 °C, filter and take out to obtain a fluorine-free waterproofing agent.

[0052] Comparative Example 2 (using octamethyl POSS instead of heptaoctyl methacryloxypropyl POSS, and the rest of the method steps are the same as those in Example 1): S1: Add PE3556 and PEG1000 with a molar ratio of 1:1 to the reaction kettle, dehydrate at 115 °C for 1.5 h; cool down to 45 °C, add isophorone diisocyanate, ensure that the R value is 3.5, raise the temperature to 88 °C and react for 2 h, cool down to 30 °C, dropwise add N-methyldiethanolamine as a chain extender, after dropping for 30 min, react at 45 °C for 0.8 h to obtain a reactant system, and ensure that the r1 value is 1.65;

[0053] S2: Add octamethyl POSS accounting for 10% of the mass of the reactant system to the reactant system, stir at 45°C for 1 h, add hydroxyethyl acrylate to block the residual NCO, carry out blocking at 65°C for 2 h, and the blocking rate is 102%; cool down to 45°C, dropwise add glacial acetic acid, stir for 0.5 h for neutralization to obtain a prepolymer, and the neutralization degree is 110%; pour the prepolymer into water at 45°C, stir, and form a POSS-PU emulsion with a solid content of 30% after emulsification;

[0054] S3: Add the POSS-PU emulsion, octadecyl ester, docosyl ester, isobornyl methacrylate, AEO9, STAC, water, TPG, and glacial acetic acid to the reaction kettle, stir rapidly at 60°C for 1 h to obtain a composite emulsion with a solid content of 25% and a pH of 4;

[0055] The POSS-PU emulsion accounts for 2.2% of the mass of the composite emulsion; octadecyl ester, docosyl ester, and isobornyl methacrylate are acrylic monomer B, and acrylic monomer B accounts for 20% of the mass of the composite emulsion. The mass ratio of octadecyl ester, docosyl ester, and isobornyl methacrylate is 5:1:0.5; AEO9 and STAC are emulsifiers, and the emulsifiers account for 0.8% of the mass of the composite emulsion. The mass ratio of AEO9 to STAC is 1:1; TPG is a co-emulsifier, and the co-emulsifier accounts for 2% of the mass of the composite emulsion; the rest is water;

[0056] S4: Pour the composite emulsion into a homogenizer, homogenize at 15 MPa for 4 times until obvious blue light appears; add dodecyl mercaptan accounting for 0.25% of the mass of acrylic monomer B and azoamidine initiator accounting for 0.5% of the mass of acrylic monomer B, react at 70°C for 3 h, cool down to 35°C, filter and take out to obtain a fluorine-free waterproofing agent.

[0057] Comparative Example 3 (changing the addition amount of heptaoctyl methacryloxypropyl POSS, and the rest of the method steps are the same as those in Example 1): S1: Add PE3556 and PEG1000 with a molar ratio of 1:1 to the reaction kettle, dehydrate at 115°C for 1.5 h; cool down to 45°C, add isophorone diisocyanate to ensure that the R value is 3.5, raise the temperature to 88°C and react for 2 h, cool down to 30°C, dropwise add N-methyldiethanolamine as a chain extender, and after dropping for 30 min, react at 45°C for 0.8 h to obtain a reactant system, ensuring that the r1 value is 1.65;

[0058] S2: Under the protection of nitrogen, mix water and anhydrous methanol, heat up to 40 °C, adjust the pH to 3 with hydrochloric acid, and dropwise add a mixed solution of octyltriethoxysilane and 3-(methacryloyloxy)propyltrimethoxysilane with a molar ratio of 7:1. After the dropwise addition of the mixed solution is completed, the system gradually becomes turbid and white. Keep the reaction at 40 °C for 5 days to obtain a turbid white solution. Place it in a separatory funnel and let it stand for layering. Separate the transparent organic layer, dissolve the organic layer with hexane, wash it with water until neutral, separate the colorless and transparent organic layer with a separatory funnel, finally remove hexane by vacuum pumping, and remove the residual moisture with CaCl2 to obtain a colorless, transparent, oily liquid with a certain viscosity, which is octaoctyl methacryloyloxypropyl POSS;

[0059] S3: Add octaoctyl methacryloyloxypropyl POSS accounting for 45% of the mass of the reactant system to the reactant system, stir at 45 °C for 1 h, add hydroxyethyl acrylate to block the residual NCO, and carry out capping at 65 °C for 2 h, with a capping rate of 102%; cool down to 45 °C, dropwise add glacial acetic acid, and stir for 0.5 h for neutralization to obtain a prepolymer, with a neutralization degree of 110%; pour the prepolymer into water at 45 °C, stir, and form a POSS-PU emulsion with a solid content of 30% after emulsification;

[0060] S4: Add the POSS-PU emulsion, octadecyl ester, docosyl ester, isobornyl methacrylate, AEO9, STAC, water, TPG, and glacial acetic acid to the reaction kettle, and stir rapidly at 60 °C for 1 h to obtain a composite emulsion with a solid content of 25% and a pH of 4;

[0061] The POSS-PU emulsion accounts for 2.2% of the mass of the composite emulsion; the octadecyl ester, docosyl ester, and isobornyl methacrylate are acrylic monomer B, and acrylic monomer B accounts for 20% of the mass of the composite emulsion. The mass ratio of the octadecyl ester, docosyl ester, and isobornyl methacrylate is 5:1:0.5; AEO9 and STAC are emulsifiers, and the emulsifiers account for 0.8% of the mass of the composite emulsion. The mass ratio of AEO9 to STAC is 1:1; TPG is a co-emulsifier, and the co-emulsifier accounts for 2% of the mass of the composite emulsion; the rest is water;

[0062] S5: Pour the composite emulsion into a homogenizer, homogenize it at 15 MPa for 4 times until there is obvious blue light; add dodecyl mercaptan accounting for 0.25% of the mass of acrylic monomer B and an azoamidine initiator accounting for 0.5% of the mass of acrylic monomer B, react at 70 °C for 3 h, cool down to 35 °C, filter and take out to obtain a fluorine-free waterproofing agent.

[0063] Comparative Example 4 (changing the addition ratio of modified lignin, and the rest of the method steps are the same as in Example 2): The addition amount of modified lignin is changed to 10% of the mass of polyol / ester.

[0064] Comparative Example 5 (changing the addition amounts of mercaptoethanol and modified rosin acid in the modified lignin, and the remaining method steps are the same as those in Example 2): The preparation of the modified lignin includes the following steps: Step 1: Dissolve 12 parts of enzymatically hydrolyzed lignin in a mixed solution 10 times its mass, add 10 parts of allyl bromide, stir at 60 °C for 24 h, and perform post-treatment to obtain allylated lignin;

[0065] Step 2: Take 12-hydroxyrosinic acid, 4-bromothiophenol, and sodium carbonate in a molar ratio of 1:1:1, add them to tetrahydrofuran and mix evenly, react at 60 °C for 5 h, and remove the solvent to obtain modified rosin acid; the addition amount of the tetrahydrofuran is 10 times the total mass of 12-hydroxyrosinic acid, 4-bromothiophenol, and sodium carbonate;

[0066] Step 3: Take 12 parts of allylated lignin, add it to 10 times its mass of tetrahydrofuran and stir evenly, add 8 parts of mercaptoethanol and 15 parts of modified rosin acid, react at 65 °C for 24 h, and remove the solvent to obtain modified lignin.

[0067] In the above examples, unless otherwise specified, the test methods used are all conventional methods; unless otherwise specified, the raw materials used can all be obtained from commercial sources, and the raw material sources are as follows: PE3556 (Huafeng); PEG1000 (S30188, Shanghai Yuanye); isophorone diisocyanate (CAS: 4098-71-9); N-methyldiethanolamine (CAS: 105-59-9); anhydrous methanol (CAS: 67-56-1); octyltriethoxysilane (CAS: 1385031-14-0); 3-(methacryloyloxy)propyltrimethoxysilane (CAS: 2530-85-0); hexane (CAS: 68476-44-8); 2-hydroxyethyl acrylate (CAS: 818-61-1); glacial acetic acid (CAS: 64-19-7); octadecyl ester (CAS: 4813-57-4); docosyl ester (CAS: 18299-85-9); isobornyl methacrylate (CAS: 7534-94-3); AEO9 (CAS: 68213-23-0); STAC (CAS: 112-03-8); TPG (CAS: 24800-44-0); dodecanethiol (CAS: 112-55-0); azoamidine initiator (azoamidine initiator V50, S15042, Shanghai Yuanye); enzymatically hydrolyzed lignin (A01095, Wuhan Jiyesheng Chemical Co., Ltd.); allyl bromide (CAS: 106-95-6); 12-hydroxyrosinic acid (CAS: 3484-61-5); 4-bromothiophenol (CAS: 106-53-6); sodium carbonate (S24152, Shanghai Yuanye); ethanol / anhydrous ethanol (CAS: 64-17-5); tetrahydrofuran (CAS: 109-99-9); mercaptoethanol (CAS: 60-24-2).

[0068] Experiment: (1) Take the fluorine-free waterproof agents prepared in Example 1 and Comparative Examples 1-3, prepare a working solution with a concentration of 30 g / L, immerse cotton and polyester fabrics cut into 40*25 cm in the working solution respectively, roll and then bake, and the baking conditions are 180*60 s; conduct waterproof tests with reference to the AATCC 22 standard. The AATCC 22 test uses a spraying device and scores according to the standard diagram; use a falling weight fabric tearing instrument for the tear strength with reference to the standard GB / T 3917.1; record the hand feeling; see Table 1 and Table 2 for details.

[0069] Table 1:

[0070]

[0071] Table 2:

[0072]

[0073] In Comparative Example 2, octamethyl POSS was used instead of heptaoctyl methacryloxypropyl POSS, and the rest of the method steps were the same as those in Example 1, but the performance decreased significantly; in Comparative Example 3, the addition amount of heptaoctyl methacryloxypropyl POSS was changed, and the rest of the method steps were the same as those in Example 1, and the performance decreased and the hand feeling became worse; Examples 2-3 were set based on Example 1, and modified lignin was additionally added to improve the waterproofness and mechanical properties. Comparative Examples 4-5 were set based on Example 2. In Comparative Example 4, the addition ratio of modified lignin was increased, and the rest of the method steps were the same as those in Example 2, but the performance was inferior to that of Example 1, and the color changed due to excessive addition of lignin; in Comparative Example 5, the addition amounts of mercaptoethanol and modified rosin acid in the modified lignin were changed, and the rest of the method steps were the same as those in Example 2. Due to the reduction of modified rosin acid, the waterproof performance also decreased significantly; in summary, the fluorine-free waterproof agent prepared by the present invention has excellent performance.

[0074] For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and without departing from the spirit or basic characteristics of the present invention, the present invention can be implemented in other specific forms. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present invention.

Claims

1. A method for preparing a fluorine-free waterproofing agent for fabrics, characterized in that: The following steps are involved: S1: Add polyol / ester into the reaction kettle, dehydrate at 110-120℃ for 1-2h; cool to 40-50℃, add isocyanate, ensure R value is 3-4, raise the temperature to 80-90℃ for reaction for 2-3h, cool to 30℃, add chain extender dropwise, react at 45-48℃ for 0.5-1h to obtain the reactant system, ensure r1 value is 1.2-2.5; S2: Add POSS to the reactant system, stir at 45-48°C for 1-2h, add acrylic monomer A, capping at 60-70°C for 1-3h, with a capping rate of 102-105%; cool to 45°C, drop acid, stir and neutralize to obtain a prepolymer with a neutralization degree of 100-140%; pour the prepolymer into water at 40-50°C, stir, and emulsify to form a POSS-PU emulsion with a solid content of 30%; S3: POSS-PU emulsion, acrylic monomer B, emulsifier, water, co-emulsifier, pH adjuster, etc. are added into a reaction kettle, and rapidly stirred at 55-60° C. for 1-2 hours to obtain a composite emulsion with a solid content of 20-25% and a pH of 3-4; S4: Pour the composite emulsion into a homogenizer, homogenize at 10-20 MPa for 4 times until there is obvious blue light; add dodecanethiol and azoamidine initiator, react at 68-70°C for 3-7h, cool to 30-40°C, filter and take out to obtain a fluorine-free waterproofing agent.

2. The method for preparing a fluorine-free waterproofing agent for fabric according to claim 1, characterized in that: The polyol / ester includes at least one of polytetramethylene glycol, polypropylene glycol, polycaprolactone, polyethylene glycol, polyethylene glycol monomethyl ether, polycarbonate, and hyperbranched polyester; the chain extender is a cationic chain extender for polyurethane; the POSS includes at least one of heptaoctyl methacryloyloxypropyl POSS, heptaisobutyl methacryloyloxypropyl POSS, quaternary ammonium base POSS, dihydroxy POSS, and amino POSS; the acrylic monomer A includes at least one of acrylic acid, hydroxyethyl acrylate, and hydroxyethyl methacrylate; the acrylic monomer B includes at least three of octadecyl acrylate, behenyl acrylate, methyl acrylate, methyl methacrylate, isobornyl acrylate, isobornyl methacrylate, cyclohexyl acrylate, cyclohexyl methacrylate, isooctyl acrylate, isooctyl methacrylate, hydroxyethyl acrylate, and hydroxyethyl methacrylate.

3. The method for preparing a fluorine-free waterproofing agent for fabric according to claim 1, characterized in that: The amount of POSS added is 5-40% of the mass of the reactant system; in the composite emulsion, POSS-PU emulsion accounts for 2-2.5% of the overall mass; the emulsifier accounts for 0.5-1% of the overall mass; the co-emulsifier accounts for 1-2% of the overall mass; the acrylic acid monomer B accounts for 15-25% of the overall mass; the rest is water; in the fluorine-free waterproofing agent, dodecanethiol accounts for 0.15-1% of the mass of the acrylic acid monomer B; and the azo amidine initiator accounts for 0.3-1% of the mass of the acrylic acid monomer B.

4. The method for preparing a fluorine-free waterproofing agent for fabric according to claim 1, characterized in that: The POSS is heptaoctylmethacryloxypropyl POSS, and its preparation method comprises the following steps: under the protection of nitrogen, water and anhydrous methanol are mixed, the temperature is raised to 30-40°C, the pH is adjusted to 2-3, a mixed solution of octyltriethoxysilane and 3-(isobutyleneoxy)propyltrimethoxysilane is added dropwise, the solution is kept warm for 1-5 days to obtain a turbid white solution, the solution is allowed to stand for stratification, a transparent organic layer is separated, the solution is dissolved with hexane, the solution is washed with water until neutral, a colorless and transparent organic layer is separated, and finally the hexane is removed by vacuum evacuation to remove the residual water to obtain heptaoctylmethacryloxypropyl POSS.

5. The method for preparing a fluorine-free waterproofing agent for fabric according to claim 1, characterized in that: In the mixed solution of octyltriethoxysilane and 3-(isomethacryloyloxy)propyltrimethoxysilane, the molar ratio of octyltriethoxysilane to 3-(isomethacryloyloxy)propyltrimethoxysilane is 7:

1.

6. The method for preparing a fluorine-free waterproof agent for fabric according to claim 1, characterized in that: Modified lignin is also added in step S1, and the added amount is 5-8% of the mass of the polyol / ester; specifically, the following steps are included: S1: polyol / ester and modified lignin are added into a reaction kettle, and dehydrated at 110-120°C for 1-2h; the temperature is lowered to 40-50°C, isocyanate is added, and the R value is ensured to be 3-4, the temperature is raised to 80-90°C for reaction for 2-3h, the temperature is lowered to 30°C, a chain extender is added dropwise, and the reaction is carried out at 45-48°C for 0.5-1h to obtain a reactant system, and the r1 value is ensured to be 1.2-2.

5.

7. The method for preparing a fluorine-free waterproofing agent for fabric according to claim 6, characterized in that: The preparation of the modified lignin comprises the following steps, calculated by weight: Step 1: dissolving the enzymatically hydrolyzed lignin in a mixed solution of NaOH solution and ethanol, adding propylene bromide, stirring at 55-60° C. for 24-25 hours, and post-treating to obtain allylated lignin; Step 2: Mix hydroxyabietic acid, bromothiophenol, sodium carbonate and tetrahydrofuran evenly, react at 50-60° C. for 3-5 hours, remove the solvent, and obtain modified abietic acid; Step 3: Take allylated lignin and add it into tetrahydrofuran, stir evenly, add mercaptoethanol and modified rosin acid, react at 60-65° C. for 24-25 hours, remove the solvent, and obtain modified lignin.

8. The method for preparing a fluorine-free waterproof agent for fabric according to claim 7, characterized in that: The allylated lignin comprises the following raw materials, calculated by weight: 10 to 15 parts of enzymatic lignin and 8 to 10 parts of propylene bromide; in the modified rosin acid, the molar ratio of hydroxyrosin acid, bromobenzenethiol and sodium carbonate is (1 to 1.2): 1: 1; the modified lignin comprises the following raw materials, calculated by weight: 10 to 15 parts of allylated lignin, 4 to 5 parts of mercaptoethanol and 25 to 30 parts of modified rosin acid.

9. The fluorine-free waterproofing agent prepared according to the method for preparing a fluorine-free waterproofing agent for fabric according to any one of claims 1 to 8.

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