A fluorine-free waterproofing agent for textiles and its preparation method and application

Abstract

The present invention proposes a fluorine-free waterproofing agent for textiles and a preparation method and application thereof, belonging to the technical field of textile auxiliaries. The preparation method comprises the following steps: S1. Preparation of silica / polyacrylate porous balls; S2. Adsorption of acrylic acid ester monomers by silica / polyacrylate porous balls; S3. Preparation of silica / polyacrylate microspheres with papillary structures; S4. Modification of silica / polyacrylate microspheres. The waterproofing agent prepared by the present invention can not only effectively improve the waterproof performance of textile products, but also has excellent durability, solves the problems of insufficient water resistance and poor durability of existing waterproofing agents, and has broad application prospects in the field of high-performance waterproof textile products.

Description

Technical Field

[0001] The invention relates to the technical field of textile auxiliaries, and in particular to a fluorine-free waterproofing agent for textiles and a preparation method and application thereof. Background Art

[0002] With the rapid development of science and technology and the improvement of living standards, people's functional requirements for textiles are also increasing. Some specially finished functional textiles have attracted much attention because they can provide people with various excellent wearing properties. Textile products with waterproof effect are one of them. Fabrics that have been waterproofed are favored by consumers because they can resist rain and do not affect the original comfort and dryness of the fabric. Textile waterproofing agents are usually used in umbrellas, tents, outdoor sportswear, printing and dyeing anti-color penetration, etc. As far as the current waterproof finishing agent market is concerned, fluorine-containing waterproofing agents are more widely used. Fluorine-containing waterproofing agents have the most obvious effect after application on textiles and have good washability, but the cost is high, and most textile fluorine-containing waterproofing agent products contain perfluorooctane sulfonyl compounds (PFOS) and perfluorooctanoic acid (PFOA). Perfluorooctane sulfonyl compounds PFOS and perfluorooctanoic acid PFOA are very stable in nature, difficult to degrade, highly bioaccumulative, have certain bioaccumulation, and have serious ecological problems. In addition, these waterproofing agents are usually not durable and are easily ineffective as the number of washings increases, resulting in a decrease in the waterproof performance of textiles. Therefore, the development of a fluorine-free waterproofing agent with a long-lasting waterproof effect has become an urgent need in the industry. Summary of the invention

[0003] The purpose of the present invention is to provide a fluorine-free waterproof agent for textiles and a preparation method and application thereof, which has excellent waterproof effect and washing resistance.

[0004] The technical solution of the present invention is achieved in this way:

[0005] The present invention provides a method for preparing a fluorine-free waterproofing agent for textiles, comprising the following steps:

[0006] S1. Preparation of silica / polyacrylate porous spheres: aminosilane and double bond silane, acrylate monomer, crosslinking agent, and oil-soluble initiator are mixed to obtain an oil phase; an emulsifier and a porogen are dissolved in water to obtain an aqueous phase;

[0007] The aqueous phase and the oil phase are mixed and emulsified, the pH value is adjusted to 3-5, and the temperature is raised to react to obtain a silica / polyacrylate porous ball emulsion; centrifugation is performed, the emulsifier and the porogen are removed by washing with water, and the silica / polyacrylate porous ball is dispersed in water again to obtain a water dispersion of silica / polyacrylate porous balls with a concentration of 20wt%-60wt%;

[0008] S2. Adsorption of acrylic acid ester monomers by silica / polyacrylate porous spheres: adding acrylic acid ester monomers and crosslinking agents to the aqueous dispersion of silica / polyacrylate porous spheres, shaking, standing, separating, and removing the lower aqueous solution to obtain an aqueous dispersion of silica / polyacrylate porous spheres with cavities adsorbing acrylic acid ester monomers and crosslinking agents;

[0009] S3. Preparation of silica / polyacrylate microspheres with papillary structures: adding a water-soluble initiator to an aqueous dispersion of silica / polyacrylate porous spheres in which acrylic monomers and crosslinking agents are adsorbed in the cavity, heating the polymerization, centrifuging, and spray drying to obtain silica / polyacrylate microspheres with papillary structures;

[0010] S4. Modification of silica / polyacrylate microspheres: Add silica / polyacrylate microspheres with a papillary structure into acetone, add a multifunctional epoxy compound, react, centrifuge, and spray dry to obtain a fluorine-free waterproofing agent.

[0011] As a further improvement of the present invention, the aminosilane in step S1 is selected from one of aminopropyltrimethoxysilane, aminopropyltriethoxysilane, N-β(aminoethyl)-γ-aminopropyltrimethoxysilane, N-β(aminoethyl)-γ-aminopropyltriethoxysilane, and γ-aminoethylaminopropyltrimethoxysilane; the double bond silane is selected from one of vinyltrimethoxysilane, vinyltriethoxysilane, vinyltri(2-methoxyethoxy)silane, vinyltriacetoxysilane, methacryloxypropyltrimethoxysilane, and methacryloxypropyltriethoxysilane; the acrylate monomer is selected from one of methyl acrylate, ethyl acrylate, butyl acrylate, hydroxyethyl acrylate, methyl methacrylate, and ethyl methacrylate; the crosslinking agent is divinylbenzene; and the oil-soluble initiator is selected from one of azobisisobutyronitrile, azobisisoheptonitrile, dimethyl azobisisobutyrate, and dibenzoyl peroxide.

[0012] As a further improvement of the present invention, in the oil phase in step S1, the mass ratio of aminosilane, double bond silane, acrylate monomer, crosslinking agent and oil-soluble initiator is 1:(0.5-2):(5-10):(1-2):(0.1-0.5).

[0013] As a further improvement of the present invention, the emulsifier in step S1 is a sodium salt hydrolysate of a styrene-maleic anhydride alternating copolymer, and its number average molecular weight is 10,000-30,000; 0.5-2 parts by mass of the emulsifier are added to every 100 parts by mass of the aqueous phase; the porogen is selected from one of polyethylene glycol octylphenyl ether and polyoxyethylene sorbitan fatty acid ester; and the mass of the porogen is 0.2-1 times the mass of the emulsifier.

[0014] As a further improvement of the present invention, in step S1, the mass ratio of the oil phase to the water phase is 1:10-30, the reaction temperature is 50-80°C, and the reaction time is 6-12h.

[0015] As a further improvement of the present invention, the acrylate monomer in step S2 is selected from one of methyl acrylate, ethyl acrylate, butyl acrylate, hydroxyethyl acrylate, methyl methacrylate, ethyl methacrylate and octadecyl methacrylate; the cross-linking agent is selected from one of ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, 1,4-butanediol dimethacrylate and hexanediol dimethacrylate; the mass ratio of the acrylate monomer to the cross-linking agent is 1:0.5-2; the shaking time is 10-60 min; the mass ratio of the porous ball to the acrylate monomer is 1:2-4.

[0016] As a further improvement of the present invention, the water-soluble initiator in step S3 is selected from one of azobisisobutylamidine hydrochloride, azobisisobutylimidazoline hydrochloride, ammonium persulfate and potassium persulfate, the concentration of the water-soluble initiator in water is 2wt%-5wt%, the polymerization temperature is 60-80°C, and the polymerization reaction time is 4-8h.

[0017] As a further improvement of the present invention, the multifunctional epoxy compound in step S4 is selected from one of 2,2'-[1,6-naphthylenebis(oxymethylene)]dioxirane and N,N,N',N'-tetracyclyl-4,4'-diaminodiphenylmethane; the mass ratio of the microspheres to the multifunctional epoxy compound is 1:0.2-0.5; the mass of the acetone is 10-30 times the mass of the microspheres, and the reaction time is 1-3h.

[0018] The present invention further protects a fluorine-free waterproofing agent prepared by the above preparation method.

[0019] The present invention further protects the use of a fluorine-free waterproofing agent prepared by the preparation method in waterproof textiles.

[0020] The principle of the present invention is as follows:

[0021] 1. In step S1, aminosilane will spontaneously face the water phase due to the hydrophilicity of amino groups, and double-bonded silane will spontaneously face the oil phase due to the lipophilicity of the double bond side. The two silanes will self-assemble at the oil-water interface, and then the sol-gel reaction will obtain silica balls with amino groups on the outside of the shell and double bonds on the inside. At the same time, the double bonds on the inside of the shell will polymerize with the acrylic acid ester monomers in the oil phase to obtain silica balls / polyacrylate balls with amino groups on the outside of the shell and polymers on the inside. As the internal reactants are consumed, hollow balls are obtained. The formation principle of shell pores is that the sodium salt hydrolysate of the emulsifier styrene-maleic anhydride alternating copolymer and the porogen will undergo microphase separation at the oil-water interface of the emulsion droplets, and the carboxyl group of the sodium salt hydrolysate of the styrene-maleic anhydride alternating copolymer will undergo electrostatic interaction with the amino group on the aminosilane, thereby inducing the silicon precursor to form a shell at the place occupied by the emulsifier, and pores will be formed at the place occupied by the porogen. After washing with water to remove the porogen, a porous silica sphere / polyacrylate shell will be obtained. The existence of the pores provides a channel for the next step of adsorbing oil-soluble monomers.

[0022] 2. In step S2, since the inner side of the silica / polyacrylate porous sphere prepared in step S1 is a lipophilic polymer layer, it will spontaneously adsorb oil-soluble acrylic ester monomers and cross-linking agents into the hydrophobic cavity, and the excess unabsorbed monomers and cross-linking agents can be removed by liquid separation.

[0023] 3. In step S3, two forces will work together to drive the papillary structure. Driving force 1: As the polymerization and cross-linking proceed, the newly adsorbed acrylate monomers will separate from the cross-linked polymers that have been grafted on the inner side of the shell layer, and thus migrate outward from the shell pores. Driving force 2: The water-soluble initiator will induce the cross-linked polyacrylate polymer molecules to migrate outward. The dual driving forces cause the cross-linked polymers to grow outward from the pores, forming a papillary structure.

[0024] 4. The papillae formed in step S3 are hydrophobic polyacrylate polymers, but the surface of the shell layer without papillae is still hydrophilic amino groups, and the surface of the shell layer is now a hydrophilic-hydrophobic patch structure. Therefore, in step S4, the hydrophilic surface is modified into a hydrophobic surface by the reaction between the epoxy group and the amino group in the multifunctional epoxy compound, thereby obtaining a fully hydrophobic surface and improving the waterproof performance of the fabric. At the same time, the surface of the fabric (especially the fabrics spun from natural fibers such as cotton and linen) often contains polar groups such as hydroxyl groups. The presence of epoxy functional groups will react with groups such as hydroxyl groups on the surface of the fabric to form chemical bonds during the fabric treatment process, and the waterproofing agent will not fall off from the surface of the fabric due to repeated washing, thereby improving the durability of the waterproofing agent.

[0025] The present invention has the following beneficial effects: the fluorine-free waterproof agent prepared by the present invention can not only effectively improve the waterproof performance of textile products, but also has excellent durability and will not fall off from the surface of the fabric after repeated washing, thus meeting the market demand for high-performance textile products. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0027] Figure 1 This is a SEM image of the fluorine-free waterproofing agent for textiles prepared in Example 1 of the present invention.

[0028] Figure 2 This is a SEM image of the fluorine-free waterproofing agent for textiles prepared in Comparative Example 1 of the present invention. DETAILED DESCRIPTION

[0029] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. 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.

[0030] Example 1

[0031] This embodiment provides a method for preparing a fluorine-free waterproofing agent for textiles, comprising the following steps:

[0032] S1. Preparation of silica / polyacrylate porous spheres: 1.8 g of aminopropyltrimethoxysilane and 1.5 g of vinyltrimethoxysilane, 10 g of butyl acrylate, 2 g of divinylbenzene, and 0.5 g of azobisisobutyronitrile were mixed to obtain an oil phase; 3 g of sodium salt hydrolyzate of styrene-maleic anhydride alternating copolymer (number average molecular weight of 20,000) as an emulsifier and 1 g of polyoxyethylene (20) sorbitan monooleate (Tween-80), a porogen, were dissolved in 200 g of water to obtain an aqueous phase;

[0033] The aqueous phase and the oil phase were mixed and emulsified, the pH value was adjusted to 3, and the temperature was raised to 70°C for reaction for 12 hours to obtain a silica / polyacrylate porous sphere emulsion; centrifuged, washed with water to remove the emulsifier and porogen, and dispersed in water again to obtain 15 g of a silica / polyacrylate porous sphere aqueous dispersion with a concentration of 40 wt%;

[0034] S2. Adsorption of acrylic acid ester monomers by silica / polyacrylate porous spheres: 12 g of butyl acrylate monomer and 6 g of crosslinking agent ethylene glycol dimethacrylate (EGDMA) were added to the aqueous dispersion of 15 g of silica / polyacrylate porous spheres, shaken for 30 min, allowed to stand, separated, and the lower aqueous solution was removed to obtain an aqueous dispersion of silica / polyacrylate porous spheres with cavity adsorption of acrylic acid ester monomers and crosslinking agents;

[0035] S3. Preparation of silica / polyacrylate microspheres with papillary structures: 0.5 g of water-soluble initiator azobisisobutylamidine hydrochloride (AIBA) was added to 20 g of aqueous dispersion of silica / polyacrylate porous spheres in which acrylate monomers and crosslinking agents were adsorbed in the cavity, and the temperature was raised to 70° C. for polymerization reaction for 8 h, centrifuged, and spray-dried to obtain silica / polyacrylate microspheres with papillary structures;

[0036] S4. Modification of silica / polyacrylate microspheres: Add 1 g of silica / polyacrylate microspheres with a papillary structure into 20 g of acetone, add 0.3 g of a multifunctional epoxy compound N,N,N',N'-tetracyclyl-4,4'-diaminodiphenylmethane (AG-80), react for 2 h, centrifuge and spray dry to obtain a fluorine-free waterproofing agent.

[0037] Comparative Example 1: The difference between this comparative example and Example 1 is that the porogen polyoxyethylene (20) sorbitan monooleate (Tween-80) is not added in step S1.

[0038] Comparative Example 2: The only difference between this comparative example and Example 1 is that the cross-linking agent ethylene glycol dimethacrylate (EGDMA) is not added in step S2.

[0039] Comparative Example 3: The difference between this comparative example and Example 1 is that the cross-linking agent ethylene glycol dimethacrylate (EGDMA) is not added in step S2, and 0.5 g of the oil-soluble initiator azobisisobutyronitrile is dissolved in 12 g of butyl acrylate monomer and adsorbed into the microsphere cavity together; and the water-soluble initiator azobisisobutyramidine hydrochloride (AIBA) is no longer added in step S3.

[0040] Comparative Example 4: The only difference between this comparative example and Example 1 is that the multifunctional epoxy compound N,N,N',N'-tetracyclyl-4,4'-diaminodiphenylmethane (AG-80) is not added in step S4.

[0041] Example 2

[0042] This embodiment provides a method for preparing a fluorine-free waterproofing agent for textiles, comprising the following steps:

[0043] S1. Preparation of silica / polyacrylate porous spheres: 1.8 g of aminopropyltrimethoxysilane and 2.5 g of methacryloyloxypropyltrimethoxysilane, 10 g of butyl acrylate, 3 g of divinylbenzene, and 0.5 g of azobisisobutyronitrile were mixed to obtain an oil phase; 2 g of sodium salt hydrolyzate of styrene-maleic anhydride alternating copolymer (number average molecular weight of 30,000) as an emulsifier and 1 g of polyoxyethylene (20) sorbitan monooleate (Tween-80) as a porogen were dissolved in 200 g of water to obtain an aqueous phase;

[0044] The aqueous phase and the oil phase were mixed and emulsified, the pH value was adjusted to 3, and the temperature was raised to 80°C for reaction for 6 hours to obtain a silica / polyacrylate porous sphere emulsion; centrifuged, washed with water to remove the emulsifier and porogen, and dispersed in water again to obtain 15 g of a silica / polyacrylate porous sphere aqueous dispersion with a concentration of 40 wt%;

[0045] S2. Adsorption of acrylic acid ester monomers by silica / polyacrylate porous spheres: 12 g of butyl acrylate monomer and 6 g of crosslinking agent ethylene glycol dimethacrylate (EGDMA) were added to the aqueous dispersion of 15 g of silica / polyacrylate porous spheres, shaken for 30 min, allowed to stand, separated, and the lower aqueous solution was removed to obtain an aqueous dispersion of silica / polyacrylate porous spheres with cavity adsorption of acrylic acid ester monomers and crosslinking agents;

[0046] S3. Preparation of silica / polyacrylate microspheres with papillary structures: 0.5 g of water-soluble initiator azobisisobutylimidazoline hydrochloride (AIPD) was added to 20 g of aqueous dispersion of silica / polyacrylate porous spheres in which acrylate monomers and crosslinking agents were adsorbed in the cavity, and the temperature was raised to 70° C. for polymerization reaction for 6 h, centrifuged, and spray-dried to obtain silica / polyacrylate microspheres with papillary structures;

[0047] S4. Modification of silica / polyacrylate microspheres: Add 1 g of silica / polyacrylate microspheres with a papillary structure into 20 g of acetone, add 0.3 g of the multifunctional epoxy compound 2,2'-[1,6-naphthylenebis(oxymethylene)]dioxirane, react for 2 h, centrifuge and spray dry to obtain a fluorine-free waterproofing agent.

[0048] Example 3

[0049] This embodiment provides a method for preparing a fluorine-free waterproofing agent for textiles, comprising the following steps:

[0050] S1. Preparation of silica / polyacrylate porous spheres: 1.8 g of aminopropyl triethoxysilane and 1.5 g of vinyl trimethoxysilane, 10 g of ethyl acrylate, 2 g of divinylbenzene, and 0.5 g of azobisisobutyronitrile were mixed to obtain an oil phase; 4 g of sodium salt hydrolyzate of styrene-maleic anhydride alternating copolymer (number average molecular weight of 10,000) as an emulsifier and 1 g of polyoxyethylene (20) sorbitan monooleate (Tween-80), a porogen, were dissolved in 200 g of water to obtain an aqueous phase;

[0051] The aqueous phase and the oil phase were mixed and emulsified, the pH value was adjusted to 4, and the temperature was raised to 60°C for reaction for 12 hours to obtain a silica / polyacrylate porous ball emulsion; centrifuged, washed with water to remove the emulsifier and porogen, and dispersed in water again to obtain 15g of a silica / polyacrylate porous ball aqueous dispersion with a concentration of 40wt%;

[0052] S2. Adsorption of acrylic acid ester monomers by silica / polyacrylate porous spheres: 12 g of octadecyl methacrylate monomer and 8 g of crosslinking agent 1,4-butanediol dimethacrylate were added to the above 15 g of silica / polyacrylate porous sphere aqueous dispersion, shaken for 30 min, allowed to stand, separated, and the lower aqueous solution was removed to obtain an aqueous dispersion of silica / polyacrylate porous spheres with cavity adsorption of acrylic acid ester monomers and crosslinking agents;

[0053] S3. Preparation of silica / polyacrylate microspheres with papillary structures: 0.5 g of water-soluble initiator azobisisobutylamidine hydrochloride (AIBA) was added to 20 g of aqueous dispersion of silica / polyacrylate porous spheres in which acrylate monomers and crosslinking agents were adsorbed in the cavity, and the temperature was raised to 70° C. for polymerization reaction for 6 h, centrifuged, and spray-dried to obtain silica / polyacrylate microspheres with papillary structures;

[0054] S4. Modification of silica / polyacrylate microspheres: Add 1 g of silica / polyacrylate microspheres with a papillary structure into 30 g of acetone, add 0.5 g of the multifunctional epoxy compound N,N,N',N'-tetracyclyl-4,4'-diaminodiphenylmethane (AG-80), react for 1 h, centrifuge and spray dry to obtain a fluorine-free waterproofing agent.

[0055] Example 4

[0056] This embodiment provides a method for preparing a fluorine-free waterproofing agent for textiles, comprising the following steps:

[0057] S1. Preparation of silica / polyacrylate porous spheres: 1.8 g of aminopropyltrimethoxysilane and 3.6 g of vinyltrimethoxysilane, 18 g of methyl acrylate, 3.6 g of divinylbenzene and 0.9 g of azobisisobutyronitrile were mixed to obtain an oil phase; 3 g of sodium salt hydrolyzate of styrene-maleic anhydride alternating copolymer (average molecular weight of 20,000) and 1 g of porogen polyoxyethylene (20) sorbitan monooleate (Tween-80) were dissolved in 200 g of water to obtain an aqueous phase;

[0058] The aqueous phase and the oil phase were mixed and emulsified, the pH value was adjusted to 3, and the temperature was raised to 70°C for reaction for 12 hours to obtain a silica / polyacrylate porous sphere emulsion; centrifuged, washed with water to remove the emulsifier and porogen, and dispersed in water again to obtain 15 g of a silica / polyacrylate porous sphere aqueous dispersion with a concentration of 40 wt%;

[0059] S2. Adsorption of acrylic acid ester monomers by silica / polyacrylate porous spheres: 12 g of butyl acrylate monomer and 6 g of crosslinking agent ethylene glycol dimethacrylate (EGDMA) were added to the aqueous dispersion of 15 g of silica / polyacrylate porous spheres, shaken for 30 min, allowed to stand, separated, and the lower aqueous solution was removed to obtain an aqueous dispersion of silica / polyacrylate porous spheres with cavity adsorption of acrylic acid ester monomers and crosslinking agents;

[0060] S3. Preparation of silica / polyacrylate microspheres with papillary structures: 0.5 g of water-soluble initiator azobisisobutylamidine hydrochloride (AIBA) was added to 20 g of aqueous dispersion of silica / polyacrylate porous spheres in which acrylate monomers and crosslinking agents were adsorbed in the cavity, and the temperature was raised to 70° C. for polymerization reaction for 6 h, centrifuged, and spray-dried to obtain silica / polyacrylate microspheres with papillary structures;

[0061] S4. Modification of silica / polyacrylate microspheres: Add 1 g of silica / polyacrylate microspheres with a papillary structure into 20 g of acetone, add 0.3 g of a multifunctional epoxy compound N,N,N',N'-tetracyclyl-4,4'-diaminodiphenylmethane (AG-80), react for 2 h, centrifuge and spray dry to obtain a fluorine-free waterproofing agent.

[0062] Performance Test:

[0063] The textile non-fluorine waterproofing agent prepared by the present invention is dispersed in ethanol to obtain a 20wt% dispersion, and the pure cotton bleached twill fabric is immersed in the dispersion for 30 minutes, double-immersed and double-rolled, baked at 80°C for 5 minutes, and baked at 160°C for 3 minutes to obtain a fabric modified by the non-fluorine waterproofing agent, and then a performance test is performed.

[0064] Test Example 1: Waterproof Effect Test

[0065] The waterproof effect test refers to the national standard GB / T 4745-2012. The specific method is as follows: Cut a sample of 18×18cm, press it with a clamp, and install it on a fixed seat at a 45° angle to the horizontal. Quickly and steadily inject 250mL (20±2℃) of distilled water or deionized water into the funnel, and spray evenly and continuously toward the center of the sample through a nozzle at a distance from the center of the sample within 25-30s. After spraying, quickly remove the clamp, make the sample face down and level, gently pat it twice, observe the degree of wetting of the sample, and then use text description and compare with pictures to evaluate its level, and take the average of 3 times.

[0066] The rating criteria are as follows:

[0067] Level 1: The exposed surface is completely wetted.

[0068] Level 2: The sample surface is wetted beyond the spray point, and the wetted area is approximately half of the sprayed surface.

[0069] Level 3: The sample surface is wetted at the spray point.

[0070] Level 4: There is sporadic wetting on the surface of the specimen at spray points.

[0071] Level 5: There is no water droplets or wetting on the surface of the specimen.

[0072] Washing resistance is to wash the finished textiles 15 times as per standard and then examine their waterproof performance.

[0073] The test results are shown in Table 1 below.

[0074] Table 1:

[0075]

[0076] Test Example 2: Contact Angle Test

[0077] In order to obtain more quantitative test results, 5 μL of water was dropped on the surface of the fabric. The DSA100 contact angle meter was used for analysis, and the test results are shown in Table 2 below. The water contact angle of the original cotton fabric is 0°.

[0078] Table 2:

[0079]

[0080] It can be seen from the above test results that the fluorine-free waterproof agent for textiles prepared in the embodiment of the present invention has good waterproof effect and durability.

[0081] The difference between Comparative Example 1 and Example 1 is that the porogen polyoxyethylene (20) sorbitan monooleate (Tween-80) is not added in step S1, no pores are formed on the shell layer, and the oil-soluble acrylate monomer and cross-linking agent in step S2 cannot enter the hydrophobic cavity, resulting in the final prepared fluorine-free waterproofing agent having no papillary result. Therefore, the waterproof effect of the cotton fabric after treatment in Comparative Example 1 is poor, and the contact angle is significantly lower than that of the example.

[0082] The only difference between Comparative Example 2 and Example 1 is that the cross-linking agent ethylene glycol dimethacrylate (EGDMA) is not added in step S2. Due to the absence of the cross-linking agent, the driving force for phase separation after the polymerization of the acrylate monomer is significantly weakened, resulting in a reduced tendency for the outward growth of papillae, resulting in fewer papillary structures on the surface of the final waterproofing agent microspheres.

[0083] The difference between Comparative Example 3 and Example 1 is that the crosslinking agent ethylene glycol dimethacrylate (EGDMA) is not added in step S2, and 0.5g of the oil-soluble initiator azobisisobutyronitrile is dissolved in 12g of butyl acrylate monomer and adsorbed into the microsphere cavity together; and the water-soluble initiator azobisisobutyramidine hydrochloride (AIBA) is no longer added in step S3. Compared with Comparative Example 2, this comparative example lacks the force of the water-soluble initiator to induce the polymer chain to migrate outward, resulting in a further reduction in the papillary structure.

[0084] The difference between Comparative Example 4 and Example 1 is that the multifunctional epoxy compound N,N,N',N'-tetraepoxypropyl-4,4'-diaminodiphenylmethane (AG-80) is not added in step S4. Since there is no hydrophobic epoxy compound to modify the amino group, the surface of the prepared fluorine-free waterproof agent microsphere has a hydrophilic-hydrophobic patch structure, so the waterproofness is significantly worse than that of Example 1. Moreover, since there is no chemical bond between the epoxy group and the fabric surface, after multiple washings, the waterproof agent will fall off the fabric surface, and the contact angle of the fabric will return to the untreated state.

[0085] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing a fluorine-free waterproofing agent for textiles, characterized in that: The following steps are involved: S1. Preparation of silica / polyacrylate porous spheres: aminosilane and double bond silane, acrylate monomer, crosslinking agent, and oil-soluble initiator are mixed to obtain an oil phase; an emulsifier and a porogen are dissolved in water to obtain an aqueous phase; the acrylate monomer in step S1 is selected from one of methyl acrylate, ethyl acrylate, butyl acrylate, hydroxyethyl acrylate, methyl methacrylate and ethyl methacrylate; the crosslinking agent in step S1 is divinylbenzene; The aqueous phase and the oil phase are mixed and emulsified, the pH value is adjusted to 3-5, and the temperature is raised to react to obtain a silica / polyacrylate porous ball emulsion; centrifugal separation, washing with water to remove the emulsifier and porogen, and dispersed in water again to obtain an aqueous dispersion of silica / polyacrylate porous balls with a concentration of 20 wt%-60wt%; the emulsifier is a sodium salt hydrolyzate of styrene-maleic anhydride alternating copolymer, and its number average molecular weight is 10000-30000; 0.5-2 mass parts of the emulsifier are added to every 100 mass parts of the aqueous phase; the porogen is selected from one of polyethylene glycol octylphenyl ether and polyoxyethylene sorbitan fatty acid ester; the mass of the porogen is 0.2-1 times the mass of the emulsifier; S2. Adsorption of acrylate monomers on silica / polyacrylate porous balls: adding acrylate monomers and crosslinking agents to the aqueous dispersion of silica / polyacrylate porous balls, shaking, standing, separating, and removing the lower aqueous solution to obtain an aqueous dispersion of silica / polyacrylate porous balls with cavities adsorbing acrylate monomers and crosslinking agents; the acrylate monomer in step S2 is selected from one of methyl acrylate, ethyl acrylate, butyl acrylate, hydroxyethyl acrylate, methyl methacrylate, ethyl methacrylate and octadecyl methacrylate; the crosslinking agent is selected from one of ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, 1,4-butanediol dimethacrylate and hexanediol dimethacrylate; S3. Preparation of silica / polyacrylate microspheres having a papillary structure: adding a water-soluble initiator to an aqueous dispersion of silica / polyacrylate porous spheres in which an acrylic monomer and a crosslinking agent are adsorbed into the cavity, polymerizing by heating, centrifuging, and spray drying to obtain silica / polyacrylate microspheres having a papillary structure; S4. Modification of silica / polyacrylate microspheres: Add silica / polyacrylate microspheres with a papillary structure into acetone, add a multifunctional epoxy compound, react, centrifuge, and spray dry to obtain a fluorine-free waterproofing agent; the multifunctional epoxy compound is selected from 2,2'-[1,6-naphthylenebis(oxymethylene)]dioxirane, N,N,N',N'-tetracyclyl-4,4'-diaminodiphenylmethane; the mass ratio of the microspheres to the multifunctional epoxy compound is 1:0.2-0.5; the mass of the acetone is 10-30 times the mass of the microspheres, and the reaction time is 1-3h.

2. The method for preparing the fluorine-free waterproofing agent for textiles according to claim 1, characterized in that: In step S1, the aminosilane is selected from one of aminopropyltrimethoxysilane, aminopropyltriethoxysilane, N-β(aminoethyl)-γ-aminopropyltrimethoxysilane, N-β(aminoethyl)-γ-aminopropyltriethoxysilane, and γ-aminoethylaminopropyltrimethoxysilane; the double bond silane is selected from one of vinyltrimethoxysilane, vinyltriethoxysilane, vinyltri(2-methoxyethoxy)silane, vinyltriacetoxysilane, methacryloxypropyltrimethoxysilane, and methacryloxypropyltriethoxysilane; the oil-soluble initiator is selected from one of azobisisobutyronitrile, azobisisoheptonitrile, dimethyl azobisisobutyrate, and dibenzoyl peroxide.

3. The method for preparing the fluorine-free waterproofing agent for textiles according to claim 1, characterized in that: In the oil phase in step S1, the mass ratio of aminosilane, double bond silane, acrylate monomer, crosslinking agent and oil-soluble initiator is 1: (0.5-2): (5-10): (1-2): (0.1-0.5).

4. The method for preparing the fluorine-free waterproofing agent for textiles according to claim 1, characterized in that: In step S1, the mass ratio of the oil phase to the water phase is 1:10-30, the reaction temperature is 50-80°C, and the reaction time is 6-12h.

5. The method for preparing the fluorine-free waterproofing agent for textiles according to claim 1, characterized in that: In step S2, the mass ratio of the acrylic ester monomer to the crosslinking agent is 1:0.5-2; the shaking time is 10-60 min; and the mass ratio of the porous ball to the acrylic ester monomer is 1:2-4.

6. The method for preparing the fluorine-free waterproofing agent for textiles according to claim 1, characterized in that: The water-soluble initiator in step S3 is selected from one of azobisisobutylamidine hydrochloride, azobisisobutylimidazoline hydrochloride, ammonium persulfate and potassium persulfate, the concentration of the water-soluble initiator in water is 2 wt%-5 wt%, the polymerization temperature is 60-80°C, and the polymerization reaction time is 4-8 h.

7. A fluorine-free waterproofing agent for textiles prepared by the preparation method according to any one of claims 1 to 6.

8. Use of the fluorine-free waterproofing agent prepared by the preparation method according to any one of claims 1 to 6 in waterproof textiles.

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