阅读说明：本技术 一种水性无氟超疏水纳米织物整理剂及其制备方法和应用 (Water-based fluorine-free super-hydrophobic nano fabric finishing agent and preparation method and application thereof ) 是由 赵燕 吴婷婷 于 2019-10-21 设计创作，主要内容包括：本发明涉及一种水性无氟超疏水纳米织物整理剂及其制备方法和应用,制备方法为：向由改性聚氨酯、纳米颗粒、长碳链硅氧烷和水组成的体系中加入交联剂搅拌均匀；制得的水性无氟超疏水纳米织物整理剂主要由改性聚氨酯乳液以及分散在其中的纳米颗粒和长碳链硅氧烷组成,改性聚氨酯乳液由改性聚氨酯和水组成,长碳链硅氧烷的链长大于等于8个碳；应用为：将水性无氟超疏水纳米织物整理剂通过浸轧法整理到织物表面。本发明的一种水性无氟超疏水纳米织物整理剂的制备方法,溶剂为水,不含氟元素,环境污染小；制得的无氟超疏水纳米织物整理剂在不同织物基材上都有良好的效果；可采用浸轧技术将该整理剂整理到织物表面,操作方便,易于规模化。(The invention relates to a water-based fluoride-free super-hydrophobic nano fabric finishing agent and a preparation method and application thereof, wherein the preparation method comprises the following steps: adding a cross-linking agent into a system consisting of modified polyurethane, nano particles, long carbon chain siloxane and water, and uniformly stirring; the prepared aqueous fluorine-free super-hydrophobic nano fabric finishing agent mainly comprises modified polyurethane emulsion, nano particles and long carbon chain siloxane dispersed in the modified polyurethane emulsion, wherein the modified polyurethane emulsion comprises modified polyurethane and water, and the chain length of the long carbon chain siloxane is more than or equal to 8 carbons; the application is as follows: finishing the water-based fluorine-free super-hydrophobic nano fabric finishing agent on the surface of the fabric by a padding method. According to the preparation method of the water-based fluorine-free super-hydrophobic nano fabric finishing agent, the solvent is water, fluorine elements are not contained, and the environmental pollution is small; the prepared fluorine-free super-hydrophobic nano fabric finishing agent has good effect on different fabric base materials; the finishing agent can be finished on the surface of the fabric by adopting a padding technology, and the finishing agent is convenient to operate and easy to scale.)

1. An aqueous fluoride-free super-hydrophobic nano fabric finishing agent is characterized in that: the modified polyurethane emulsion mainly comprises modified polyurethane emulsion, nanoparticles and long-carbon-chain siloxane, wherein the nanoparticles and the long-carbon-chain siloxane are dispersed in the modified polyurethane emulsion, the modified polyurethane emulsion comprises modified polyurethane and water, and the chain length of the long-carbon-chain siloxane is more than or equal to 8 carbons.

2. The water-based fluorine-free super-hydrophobic nano fabric finishing agent as claimed in claim 1, wherein the chain length of the long carbon chain siloxane is 8-18 carbons, and the nano particles are SiO₂The nano-particles and the aqueous fluorine-free super-hydrophobic nano-fabric finishing agent also comprise a cross-linking agent.

3. The water-based fluorine-free super-hydrophobic nano fabric finishing agent as claimed in claim 2, wherein in the water-based fluorine-free super-hydrophobic nano fabric finishing agent, the mass ratio of the modified polyurethane to the long carbon chain siloxane is 5: 1-10, and the modified polyurethane to the SiO₂The mass ratio of the nano particles is 10: 1-30, the mass ratio of the modified polyurethane to water is 100: 1-10, and the mass ratio of the modified polyurethane to the cross-linking agent is 100: 1-20.

4. The aqueous fluorine-free super-hydrophobic nano fabric finishing agent as claimed in claim 2, wherein the preparation steps of the modified polyurethane are as follows:

(1) mixing polyethylene glycol, polydimethylsiloxane, isophorone diisocyanate and dibutyltin dilaurate in a molar ratio of 10-30: 40-100: 200-500: 1-10, stirring at a speed of 100-200 rpm, and heating to 80-90 ℃ for reaction for 30-40 min;

(2) keeping the stirring speed and the temperature unchanged, adding dimethylolpropionic acid into the system in the step (1), and reacting for 2-3 h, wherein the molar addition amount of the dimethylolpropionic acid is 70-90% of that of the isophorone diisocyanate in the step (1);

(3) and (3) cooling the system in the step (2) to 20-35 ℃, and adding triethylamine to prepare the modified polyurethane, wherein the molar addition amount of the triethylamine is 100-130% of that of the dimethylolpropionic acid in the step (2).

5. The aqueous fluorine-free super-hydrophobic nano fabric finishing agent as claimed in claim 2, wherein SiO is₂The preparation steps of the nano-particles are as follows:

(1) dropping tetraethoxysilane into a mixed solution of ethanol and ammonia water, stirring at the speed of 200-300 rpm, heating to 40-50 ℃, and reacting for 4 hours, wherein the volume ratio of ethanol to ammonia water in the mixed solution of ethanol and ammonia water is 20-60: 1-5, and the volume ratio of tetraethoxysilane to the mixed solution of ethanol and ammonia water is 1-3: 40-60;

(2) keeping the stirring speed and temperature unchanged, and dropwise adding tetraethoxysilane into the system in the step (1) to react for 8-16 h to obtain SiO₂And (2) nano particles, wherein the mass addition amount of the tetraethoxysilane is 70-100% of that of the tetraethoxysilane in the step (1).

6. The aqueous fluorine-free super-hydrophobic nano fabric finishing agent as claimed in claim 2, wherein the long carbon chain siloxane is dodecyl trimethoxy silane, dodecyl triethoxy silane or hexadecyl trimethoxy silane.

7. The aqueous fluorine-free super-hydrophobic nano fabric finishing agent as claimed in claim 2, wherein the cross-linking agent is polyfunctional aziridine, polyisocyanate, amino resin or epoxy cross-linking agent.

8. The method for preparing the water-based fluorine-free super-hydrophobic nano fabric finishing agent as defined in any one of claims 1 to 7, which is characterized in that: adding a cross-linking agent into a system consisting of modified polyurethane, nano particles, long-carbon-chain siloxane and water, and uniformly stirring to obtain the aqueous fluorine-free super-hydrophobic nano fabric finishing agent, wherein the chain length of the long-carbon-chain siloxane is more than or equal to 8 carbons.

9. The use of the aqueous fluorine-free super-hydrophobic nano fabric finishing agent as claimed in any one of claims 1 to 7, characterized in that: finishing the water-based fluorine-free super-hydrophobic nano fabric finishing agent on the surface of the fabric by a padding method.

10. The use according to claim 9, wherein the padding is two-padding and two-rolling, and the single-dipping time is 30-60 s; after padding, baking the fabric for 10-40 min at the temperature of 100-180 ℃; the fabric is polyester, cotton cloth, nylon or wool fabric; the water contact angle of the surface of the finished fabric is 155.5-167.1 degrees, and the rolling angle is 9.5-23.7 degrees.

Technical Field

The invention belongs to the technical field of functional fabric finishing, and relates to an aqueous fluorine-free super-hydrophobic nano fabric finishing agent, and a preparation method and application thereof.

Background

Most of organic fluorochemicals used for textile 'three-proofing' finishing contain perfluorooctane sulfonyl compounds (PFOS) or perfluorooctanoic acid (PFOA), or are degraded to generate PFOS or PFOA compounds. Research shows that PFOS and PFOA are stable in property, not easy to degrade, and have bioaccumulation and certain toxicity, and are novel environmental pollutants all over the world. In 2006, the european parliament and the ministry of officials have jointly issued "instructions on limiting the sale and use of perfluorooctanesulfonic acid", which require: "a substance having a concentration or mass of 0.005 parts per million or more, which is marketed in the european union market and has PFOS as a constituent substance or element, will not be marketed; and finished products, semi-finished products and parts, which use PFOS in finished products and semi-finished products and have a concentration or mass equal to or exceeding 0.1%, will also be listed as a sale prohibition range ". In addition, PFOA is suspected of having similar hazardousness to PFOS and remains to be evaluated, and restrictions are currently placed on PFOA discharge and use in both the european union and the united states. Because no method for effectively solving the pollution problem of the PFOS and the PFOA exists at home and abroad at present, the search for the substitute products of the PFOS and the PFOA becomes a problem to be solved urgently in the auxiliary industry.

There are no two alternative products of PFOS and PFOA, one is a low-fluorocarbon number compound which is non-PFOS, namely C6 or C4 waterproof agent is commonly used to replace C8 waterproof agent, and the safety of the low-fluorocarbon number compound is still required to be further verified although the low-fluorocarbon number compound is considered to have relatively low bioaccumulation and toxicity; the other one is a fluorine-free waterproof agent completely free of fluorine, and the waterproof agent is non-toxic, easy to degrade, free of organism accumulation and free of troubles of environmental safety protection, and is a key direction for developing the conventional fabric waterproof agent. Chinese patent with application number 201810615450.X discloses a preparation method of a fluorine-free super-hydrophobic cotton fabric by utilizing paraffin, palm wax and MgSO₄Preparing composite wax emulsion from polyvinyl alcohol and water, and passing through ethyl orthosilicate and MgSO₄Preparation of SiO from polyvinyl alcohol and hexadecyl trimethoxy silane₂Sol, soaking cotton fabric in SiO₂Drying the sol and then soaking the sol in the composite wax emulsion to prepare a super-hydrophobic coating; the Chinese patent with the application number of 201710058038.8 discloses a preparation method of a fluorine-free super-hydrophobic surface, which is characterized in that polymethyl methacrylate and/or polydimethylsiloxane are dissolved in a solvent, ultrasonic wave is adopted to promote the dissolution, and a super-hydrophobic coating liquid is prepared, wherein the solvent is selected from tetrahydrofuran which is an organic solvent.

Although these and other few fluorine-free superhydrophobic textile finishes exist, these finishes are complicated in their preparation or use organic solvents, which are still not satisfactory for safety and environmental protection.

Therefore, the development of an aqueous, fluorine-free and mechanically good superhydrophobic fabric finishing agent is very necessary and meets the application requirements.

Disclosure of Invention

The invention aims to solve the problems that the preparation of a fluorine-free super-hydrophobic fabric finishing agent is complex, an organic solvent used in the preparation process does not meet the requirements of safety and environmental protection and the mechanical stability is not good enough in the prior art, and provides an aqueous fluorine-free super-hydrophobic nano fabric finishing agent, and a preparation method and application thereof.

In order to achieve the purpose, the invention adopts the following scheme:

an aqueous fluorine-free super-hydrophobic nano fabric finishing agent mainly comprises modified polyurethane emulsion, nano particles and long carbon chain siloxane dispersed in the modified polyurethane emulsion, wherein the modified polyurethane emulsion comprises modified polyurethane and water, and the chain length of the long carbon chain siloxane is more than or equal to 8 carbons; the fluorine can realize superhydrophobicity because the fluorine has lower surface energy, and the long carbon chain also has lower surface energy, and the longer the chain length is, the lower the surface energy is, the less easily the liquid drop can contact the surface, so the long carbon chain is used for replacing the fluorine chain, and the superhydrophobic effect is realized; the surface energy of siloxane is lower than that of water, the siloxane has hydrophobic performance, when the siloxane is added into the modified polyurethane emulsion, the siloxane can be adsorbed on modified polyurethane emulsion particles through hydrophobic interaction and van der Waals force, the siloxane is hydrolyzed after being added into the modified polyurethane emulsion, and a product after hydrolysis and hydroxyl on the modified polyurethane are subjected to condensation reaction, so that the siloxane is introduced into the modified polyurethane, and the modified polyurethane contains hydrophilic groups, so that the modified polyurethane can be dissolved in water to form stable emulsion. Furthermore, the present invention is also effective in improving the mechanical stability of the textile finish because: 1) three methyl/ethyl groups in the siloxane can be hydrolyzed and form an interpenetrating network structure with the modified polyurethane, so that the mechanical property of the fabric finishing agent is improved; 2) in the process of forming the film by water volatilization, the nano particles are mutually close to contact, and the long chains of polyurethane molecules are mutually diffused, so that a homogeneous film with certain mechanical property is formed.

As a preferred technical scheme:

the long-carbon-chain siloxane has the chain length of 8-18 carbons, and the nano particles are SiO₂Nanoparticles of SiO₂The nano particles have certain roughness, so that water drops can be suspended on the rough structure of the nano particles, the air filled in the grooves has certain supporting effect on the water drops, the hydrophobic effect is better, and the water-based fluorine-free super-hydrophobic nano fabric finishing agent also comprises a cross-linking agent which is a cross-linking agentPlays a role in enhancing the firmness of the coating, and can also achieve the super-hydrophobic property without a cross-linking agent.

According to the waterborne fluorine-free super-hydrophobic nano fabric finishing agent, in the waterborne fluorine-free super-hydrophobic nano fabric finishing agent, the mass ratio of the modified polyurethane to the long carbon chain siloxane is 5: 1-10, the hydrophobic performance of the prepared waterborne super-hydrophobic nano fabric finishing agent is the best when the mass ratio of the modified polyurethane to the long carbon chain siloxane is in the range, if the occupation ratio of the long carbon chain siloxane is too small, the hydrophobic performance is insufficient, when the long carbon chain siloxane is increased to a certain ratio, the hydrophobicity tends to be stable and does not increase any more, and the modified polyurethane and the SiO have the advantages that the modified polyurethane and the long carbon chain siloxane have the best₂The mass ratio of the nano particles is 10: 1-30, and SiO is₂It should not be used in too large or too small an amount, if SiO₂An excessively small amount may result in insufficient roughness, but SiO₂The fabric has hard hand feeling and reduced hydrophobic property due to excessive amount, the mass ratio of the modified polyurethane to water is 100: 1-10, the mass ratio of the modified polyurethane to the cross-linking agent is 100: 1-20, the presence of the cross-linking agent can increase the hydrophobic property and mechanical property of the fabric, and when the amount is increased to a certain amount, the influence on the hydrophobic property of the fabric is not enhanced.

The preparation method of the aqueous fluorine-free super-hydrophobic nano fabric finishing agent comprises the following steps:

(1) mixing polyethylene glycol (PEG), Polydimethylsiloxane (PDMS), isophorone diisocyanate (IPDI) and dibutyltin Dilaurate (DBT) in a molar ratio of 10-30: 40-100: 200-500: 1-10, stirring at a speed of 100-200 rpm, and heating to 80-90 ℃ for reaction for 30-40 min;

(2) keeping the stirring speed and the temperature unchanged, adding dimethylolpropionic acid (DMPA) into the system obtained in the step (1), and reacting for 2-3 h, wherein the molar addition amount of the dimethylolpropionic acid (DMPA) is 70-90% of that of isophorone diisocyanate in the step (1);

(3) and (3) cooling the system in the step (2) to 20-35 ℃ (the system is easy to generate gel at high temperature), adding triethylamine to prepare the modified polyurethane, wherein the molar addition amount of the triethylamine is 100-130% of that of dimethylolpropionic acid (DMPA) in the step (2), the triethylamine is used for neutralizing the DMPA, and the triethylamine cannot be completely neutralized when the triethylamine is too low, and more triethylamine remains when the triethylamine is too high.

An aqueous fluorine-free super-hydrophobic nano fabric finishing agent, SiO₂The preparation steps of the nano-particles are as follows:

(1) dropping tetraethoxysilane into a mixed solution of ethanol and ammonia water, stirring at the speed of 200-300 rpm, heating to 40-50 ℃, and reacting for 4 hours, wherein the volume ratio of ethanol to ammonia water in the mixed solution of ethanol and ammonia water is 20-60: 1-5, and the volume ratio of tetraethoxysilane to the mixed solution of ethanol and ammonia water is 1-3: 40-60;

(2) keeping the stirring speed and temperature unchanged, and dropwise adding tetraethoxysilane into the system in the step (1) to react for 8-16 h to obtain SiO₂The mass addition amount of the tetraethoxysilane is 70-100% of that of the tetraethoxysilane in the step (1), and the content of the tetraethoxysilane can influence SiO₂The larger the particle size, the more SiO₂The larger the particle, the smaller the SiO₂The particles will be smaller.

The long-carbon-chain siloxane is dodecyl trimethoxy silane, dodecyl triethoxy silane or hexadecyl trimethoxy silane.

The crosslinking agent is polyfunctional aziridine, polyisocyanate, amino resin or epoxy crosslinking agent, and the crosslinking agent is added in the preparation process of the super-hydrophobic fabric nano finishing agent, so that the crosslinked polyurethane and the hydrolytic condensed siloxane form an interpenetrating network, and the mechanical property of the fabric finishing agent can be improved.

The invention also provides a method for preparing the waterborne fluorine-free super-hydrophobic nano fabric finishing agent, which is characterized in that the waterborne fluorine-free super-hydrophobic nano fabric finishing agent is prepared by adding the cross-linking agent into a system consisting of the modified polyurethane, the nano particles, the long carbon chain siloxane and water and uniformly stirring (the waterborne polyurethane is used as a main medium and the long carbon chain siloxane is dispersed in the waterborne polyurethane), wherein the chain length of the long carbon chain siloxane is more than or equal to 8 carbonsThe system composed of the modified polyurethane, the nanoparticles, the long carbon chain siloxane and the water can be prepared by various methods, for example, by adding the modified polyurethane, the nanoparticles and the long carbon chain siloxane to the water separately, for example, by adding the aqueous dispersion of the modified polyurethane, the nanoparticles and the long carbon chain siloxane to the water separately, for example, by adding the modified polyurethane, the aqueous dispersion of the nanoparticles and the long carbon chain siloxane to the aqueous dispersion of the modified polyurethane, for example, by adding the modified polyurethane and the long carbon chain siloxane to the aqueous dispersion of the nanoparticles, for example, by mixing the aqueous dispersion of the modified polyurethane, the aqueous dispersion of the nanoparticles and the long carbon chain siloxane, and the specific method is not limited as long as the system composed of the modified polyurethane, the nanoparticles, the long carbon chain siloxane and the water is obtained, wherein the solid content of the aqueous dispersion of the modified polyurethane is 0.05-5 percent, and the aqueous dispersion of the modified polyurethane is specifically prepared by mixing the modified polyurethane with water and stirring at the stirring speed of 1000-15000 rpm until the modified polyurethane is uniformly dispersed, wherein SiO is₂The concentration of the nano-particle water dispersion liquid is 0.01-0.2 g/mL, and specifically, SiO is added₂The nano particles are centrifugally dispersed in water.

The invention also provides application of the aqueous fluorine-free super-hydrophobic nano fabric finishing agent, which is used for finishing the aqueous fluorine-free super-hydrophobic nano fabric finishing agent on the surface of a fabric by a padding method.

As a preferred technical scheme:

in the application, the padding is two-dipping and two-rolling, and the time of single dipping is 30-60 s; after padding, baking the fabric for 10-40 min at the temperature of 100-180 ℃; the fabric is polyester, cotton cloth, nylon or wool fabric; the water contact angle of the surface of the finished fabric is 155.5-167.1 degrees, and the rolling angle is 9.5-23.7 degrees.

Has the advantages that:

(1) according to the preparation method of the water-based fluorine-free super-hydrophobic nano fabric finishing agent, the solvent is water, fluorine is not contained, the cost is low, and the environmental pollution is small;

(2) according to the preparation method of the water-based fluorine-free super-hydrophobic nano fabric finishing agent, the long carbon chain siloxane is dissolved in the modified polyurethane, and then the mixture of the modified polyurethane and the long carbon chain siloxane is dissolved in water, so that the problem that low-surface-energy substances are difficult to disperse in water is solved;

(3) the water-based fluorine-free super-hydrophobic nano fabric finishing agent has good effects on different fabric substrates, and the water contact angle of the surface of the finished fabric is 155.5-167.1 degrees, so that the water-based fluorine-free super-hydrophobic nano fabric finishing agent has good self-cleaning performance;

(4) the invention finishes the water-based fluorine-free super-hydrophobic nano fabric finishing agent on the surface of the fabric by adopting a padding technology, has convenient operation, small dependence on equipment and easy scale production.

Drawings

FIG. 1 is SiO₂Schematic representation of the contact of the rough surface of the nanoparticles with water droplets;

FIG. 2 is a plot of the particle size distribution of the fabric finish of comparative example 1 of the present invention;

FIG. 3 is a graph of the static contact angle of water on the fabric surface after finishing with the aqueous fluorine-free superhydrophobic nano-fabric finishing agent of example 14 of the invention;

FIG. 4 is an EDS energy spectrum of the fabric surface after the aqueous fluorine-free super-hydrophobic nano fabric finishing agent of example 14 of the invention is finished;

FIG. 5 is an SEM image (magnification 5000) of the surface of an unfinished fabric;

FIG. 6 is an SEM image (magnification 5000) of the finished surface of the aqueous fluorine-free super-hydrophobic nano fabric finishing agent of example 14 of the invention.

Detailed Description

The invention will be further illustrated with reference to specific embodiments. It should be understood that these examples are for illustrative purposes only and are not intended to limit the scope of the present invention. Further, it should be understood that various changes or modifications of the present invention may be made by those skilled in the art after reading the teaching of the present invention, and such equivalents may fall within the scope of the present invention as defined in the appended claims.