WO2018001204A1

WO2018001204A1 - Novel material with hydrophobic function and preparation process therefor

Info

Publication number: WO2018001204A1
Application number: PCT/CN2017/090034
Authority: WO
Inventors: 张治国; 雷加元; 岳广磊
Original assignee: 天津和悦新材料有限公司
Priority date: 2016-06-27
Filing date: 2017-06-26
Publication date: 2018-01-04
Also published as: CN105950053B; CN105950053A

Abstract

Disclosed are a novel material with a hydrophobic function and preparation process therefor. A surface of the novel material is in a bionic structure of a lotus leaf. The novel material comprises from bottom to top a substrate layer, a microporous foaming modified adhesive layer and a wax-containing layer dispersedly coated on the microporous foaming modified adhesive layer. The process comprises: firstly, during preparation of the adhesive layer, sufficiently mixing raw materials of the adhesive layer with a dispersing agent and a foaming agent and coating said mixture to a surface of a substrate; using a coating foaming process so as to obtain a modified substrate, and finally dispersedly coating wax to an outer surface of the obtained modified substrate, thereby obtaining the novel material. A rough structure on a surface of a product of the present invention is fundamentally similar to a mastoid process in a micro-nano structure on a rough surface of a lotus leaf and the structure of a hydrophobic waxy material on the surface, and a bionic structure of a lotus leaf is achieved, thereby having a good hydrophobic function.

Description

New material with hydrophobic function and preparation process thereof

Technical field

The invention relates to a new material and a preparation process thereof, in particular to a new material having a hydrophobic function and a preparation process thereof.

Background technique

In recent years, superhydrophobicity in the natural world (contact angle greater than 150°, rolling angle less than 10°) and self-cleaning phenomena have attracted research interest. The artificially prepared superhydrophobic surface can be used for anti-fouling of automobile windows, glazing windows of buildings and glass exterior walls, and can be used for radar and antenna surfaces to prevent signal attenuation caused by snow and rain adhesion, and superhydrophobic surface of materials can be suppressed. The adhesion of microorganisms on the surface of the object inhibits the coagulation phenomenon on the surface of the polymer, and is used for water transport and oil transfer to reduce the fluid resistance. Research on superhydrophobic surfaces has become a hot topic, involving many disciplines such as botany, chemistry, materials science, and engineering mechanics.

The surface of some plants in nature has super-hydrophobic properties and self-cleaning functions, the most typical of which is the surface of the lotus leaf, which forms a "self-cleaning effect of the lotus leaf" and "discharges the mud without dyeing". Researchers such as German biologist Barthlott have studied the surface of nearly 300 plant leaves, and believe that the self-cleaning properties of plant leaves are made up of micro-structured mastoids on the rough surface and hydrophobic waxy materials on the surface. of.

At present, a number of methods have been used to prepare imitation lotus leaf surfaces. Including etching, phase separation and self-assembly methods, hydrothermal methods, chemical deposition and electrodeposition methods, sol-gel methods, electrospinning methods, carbon nanotube methods, template methods and the like. Although there are many methods for preparing superhydrophobic surfaces, the above methods have great limitations. For example, lithography and laser etching can only process small-area surfaces, cannot process shaped surfaces, and the equipment is complicated and expensive. The polymer phase separation method or the self-assembly method can only be applied to a small-area surface, and the obtained super-hydrophobic surface is not resistant to high temperature, and melts at a high temperature, and the morphology is easily destroyed. Electrodeposition or chemical deposition methods have requirements on equipment and harsh conditions. Hydrothermal and sol-gel methods can only process small-area surfaces. As for carbon nanotubes, the requirements are more demanding, requiring high temperatures or equipment limitations. . Electrospinning has limitations on equipment and cannot be used for outdoor operations. The porous alumina stencil required for the templating method is not easy to prepare and cannot process a shaped surface or a large-area surface. Fluorine-containing materials such as perfluorosiloxanes for surface modification are very expensive. Therefore, it is not yet There is a large-scale production of super-hydrophobic products for industrial or daily life. The problem to be solved is that the manufacturing method is simple, suitable for large test pieces, shaped surfaces, stable performance, and certain mechanical strength.

In summary, various existing methods have various drawbacks and are in urgent need of improvement.

Summary of the invention

The present invention is directed to various deficiencies existing in the prior art, and provides a new material having a hydrophobic function and a preparation process thereof.

In order to achieve the above object, the present invention is achieved by such a technical solution:

The invention discloses a new material having a hydrophobic function, the surface of the new material is a lotus leaf bionic structure, comprising a bottom layer of a substrate layer, a microcellular foaming modified adhesive layer and a dispersion coating on the micro The waxy layer on the foamed modified adhesive layer.

The invention also discloses a preparation method of a new material having a hydrophobic function, characterized in that the preparation steps are as follows:

1) mixing the adhesive layer raw material and the dispersant fine particles and the foaming agent in a certain ratio, adjusting the appropriate viscosity of the coating with a solvent, and coating on the surface of the substrate layer;

2) after coating the substrate layer, after coating the foaming process, obtaining a microcellular foaming modified adhesive layer on the surface of the substrate layer;

3) coating a wax-soluble (melting) liquid or a wax emulsion or a wax dispersion on the surface of the obtained microporous foam-modified adhesive layer by a coating process to form a wax-containing layer, and drying to obtain a surface having a lotus leaf bionic structure. new material.

As a further improvement, the dispersing agent of the present invention is silica or titania fine particles having a particle size of from 1 nm to 10 μm.

As a further improvement, the components of the foaming agent of the present invention are sodium carbonate/citric acid, sodium hydrogencarbonate, azodicarbonamide, diisopropyl azodicarboxylate, diethyl azodicarboxylate, 4 Any of 4'-oxidized bisbenzenesulfonylhydrazide.

As a further improvement, the adhesive layer raw material, the dispersant fine particles and the foaming agent of the present invention are weighted The ratio is 1:0.01-0.4: 0.01-0.1 in a sufficient ratio.

As a further improvement, the adhesive layer coating process in the step 1) of the present invention is any one of a spray coating method, a roll coating method, a gravure coating method, a bar coating method, a brush coating method, and a doctor blade method. The coating process of the wax in the step 3) is any one of a spray coating method, a roll coating method, a gravure coating method, a bar coating method, a brush coating method, and a doctor blade method.

As a further improvement, in the step 2) of the present invention, the film is dried to form an adhesive layer, and microcellular foaming of the adhesive layer structure is realized.

As a further improvement, the wax of the present invention is a vegetable wax or a synthetic wax, and the vegetable wax is any one of insect white wax, wood wax, bayberry wax, Chinese wax, wool wax, Japanese wax, rice bran wax, and beeswax. The synthetic wax is any one of Fischer-Tropsch wax, polyethylene wax, polypropylene wax, ethylene-vinyl acetate copolymer wax, and oxidized polyethylene wax.

As a further improvement, in the step 3) of the present invention, the coating wax has a basis weight of 0.01 to 10 g/m ² .

As a further improvement, the new material having the lotus leaf bionic structure on the surface prepared by the present invention has a contact angle of more than 150° and a rolling angle of less than 10° in the hydrophobicity test.

The beneficial effects of the present invention are as follows:

1. The present invention provides a new material having a hydrophobic function, which is prepared by constructing a lotus leaf bionic structure on the surface of the substrate layer, firstly by preparing the adhesive layer raw material and dispersant in the preparation of the adhesive layer. The foaming agent is thoroughly mixed and coated on the surface of the substrate, and after the coating foaming process, a modified substrate is obtained, and finally, the wax is dispersed and coated on the outer surface of the obtained modified substrate to prepare. The rough structure on the surface of the product of the invention is basically similar to the structure of the micro-nano-structured milk-protrusion and the surface-hydrophobic waxy material on the rough surface of the lotus leaf, realizing the lotus leaf bionic structure and thus having a good hydrophobic function.

2. The invention adopts the method that the adhesive layer raw material is thoroughly mixed with the dispersing agent and the foaming agent and is coated on the surface of the substrate, and after the coating foaming process, the modified substrate adhesive layer is obtained. The method of the invention has the advantages of simple process and low cost by constructing the micro-nano structure mastoid layer on the surface of the substrate layer by the microcellular foaming process.

3. The invention adopts a new material prepared by dispersing and coating a wax on the outer surface of the obtained modified substrate to obtain a hydrophobic function. The presence of a low surface energy waterproof waxy crystal on the surface allows the product of the invention to have Excellent hydrophobic properties.

4. The material of the invention has excellent properties and long service life. These surface modification structures do not affect the application performance of the material itself, and can be widely applied to the fields of sealed container structures, packaging materials, pipes, external surfaces and the like.

DRAWINGS

Figure 1 is a schematic view showing the structure of a new material having a hydrophobic function;

In the figure, 1 is a substrate layer, 2 is a microcellular foamed modified adhesive layer, and 3 is a wax-containing layer.

detailed description

The invention discloses a new material with hydrophobic function, FIG. 1 is a schematic structural view of a new material with hydrophobic function; in the figure, from bottom to top is a substrate layer 1, a microporous foam modified adhesive layer 2 And a wax-containing layer 3 dispersedly coated on the microcellular foamed modified adhesive layer 2. The technical solutions of the present invention are further described in detail below with reference to specific embodiments, but the scope of the present invention is not limited to the embodiments.

Example 1

The substrate was coated with a vapor-deposited polyethylene terephthalate film (VMPET) and coated on the PET side. Using a heat sealant polyurethane TPU resin adhesive, add a certain amount of solvent ethyl acetate to dissolve completely, add a certain amount of dispersant silica and foaming agent sodium bicarbonate for thorough mixing, stir at room temperature and then let stand After getting the paint. The dispersant is silica fine particles having a particle size of 12 nm. The blowing agent is sodium bicarbonate, food grade. The solvent is ethyl acetate, food grade. The weight ratio of the adhesive layer raw material, the dispersant fine particles, the foaming agent and the solvent is =1:0.01:0.01:3. The resulting coating viscosity was 1900 cps. The resulting coating was then applied to the surface of the substrate by a roll coating process.

After the coating drying process, the adhesive layer is obtained by drying to form a film, and microcellular foaming of the adhesive layer structure is achieved. The film was coated on the surface of the substrate and dried at 150 ° C for 30 s to effect solvent evaporation and foaming of the foaming agent to obtain a fine structure, and the obtained coating layer had a basis weight of 20 g/m ² . After the coating of the substrate, a microcellular foamed surface-modified substrate is obtained on the surface of the substrate layer 1 by a coating foaming process.

The insect white wax micropowder (100 mesh) was heated and dissolved in an ethanol solution to obtain a 1% wax solution. The surface of the microporous foamed surface-modified substrate was sprayed by a spraying process, and after the solvent was evaporated after drying, the coating wax had a basis weight of 0.01 g/m ² . Thus, a new material having a lotus leaf bionic structure on the surface was obtained. In the hydrophobicity experiment, the contact angle was 160° and the rolling angle was 6°.

Example 2

The substrate was made of a polyethylene film (LDPE) and coated on the surface. Acrylic resin adhesive product, adding a certain amount of solvent ethyl acetate dissolved completely, adding a certain amount of dispersant titanium dioxide and foaming agent azodicarbonamide for thorough mixing, stirring at room temperature, and then standing after leaving . The dispersing agent is titanium dioxide fine particles having a particle size of 10 μm. The blowing agent is azodicarbonamide, food grade. The solvent is ethyl acetate, food grade. The weight ratio of the adhesive layer raw material, the dispersant fine particles, the foaming agent and the solvent is =1:0.4:0.1:4. The resulting coating had a viscosity of 1500 cps. The resulting coating is then applied to the surface of the substrate by a gravure coating process.

After the coating drying process, the adhesive layer is obtained by drying to form a film, and microcellular foaming of the adhesive layer structure is achieved. The film was coated on the surface of the substrate and dried at 150 ° C for 30 s to effect solvent evaporation and foaming of the foaming agent to obtain a fine structure, and the obtained coating amount was 40 g/m ² . After the coating of the substrate, a microcellular foamed surface-modified substrate is obtained on the surface of the substrate layer 1 by a coating foaming process.

A polyethylene wax emulsion (having a particle size of less than 1.0 μm) was heated and dissolved in an ethanol solution to obtain a 1% wax emulsion. The coating was applied to the surface of the microcellular foamed surface-modified substrate by a roll coating process, and after the solvent was evaporated after drying, the coating wax had a basis weight of 10 g/m ² . Thus, a new material having a lotus leaf bionic structure on the surface was obtained. In the hydrophobicity experiment, the contact angle was 152° and the rolling angle was 8°.

Example 3

The substrate was made of polystyrene sheet (PS). Using a heat-sealing paint adhesive product (160 parts by weight of polyester resin + 10 parts by weight of acrylic resin), adding a certain amount of a mixed solvent of toluene and methyl ethyl ketone, and after completely dissolving, adding a certain amount of dispersant titanium dioxide and foaming agent The 4,4'-oxidized bisbenzenesulfonyl hydrazide was thoroughly mixed, and after sufficiently stirring at room temperature, it was allowed to stand to obtain a coating. The dispersing agent is titanium dioxide fine particles having a particle size of 1 nm. The blowing agent is 4,4'-oxidized bisbenzenesulfonyl hydrazide, food grade. The weight ratio of the adhesive layer raw material, the dispersant fine particles, the foaming agent and the solvent is =1:0.04:0.03:5. The resulting coating viscosity was 1000 cps. The resulting coating is then applied to the surface of the substrate by a spray coating process.

After the coating drying process, the adhesive layer is obtained by drying to form a film, and microcellular foaming of the adhesive layer structure is achieved. The film was coated on the surface of the substrate and dried at 180 ° C for 30 s to effect solvent evaporation and foaming of the foaming agent to obtain a fine structure, and the obtained coating was quantitatively 25 g/m ² . After the coating of the substrate, a microcellular foamed surface-modified substrate is obtained on the surface of the substrate layer 1 by a coating foaming process.

The wax is melted by heating with Japanese wax. The surface of the microporous foamed surface was modified by a spraying process to modify the surface of the substrate, and after the solvent was evaporated after drying, the coating wax had a basis weight of 1.0 g/m ² . Thus, a new material having a lotus leaf bionic structure on the surface was obtained. In the hydrophobicity experiment, the contact angle was 151° and the rolling angle was 5°.

Example 4

The substrate was made of kraft paper and the basis weight was 110 g/m ² . Use starch adhesive products. In the gelatinized starch adhesive, a certain amount of dispersant silica and a foaming agent sodium carbonate/citric acid are added and thoroughly mixed, and after sufficiently stirring at room temperature, the mixture is allowed to stand to obtain a coating. The dispersant is silica fine particles having a particle size of 100 nm. The blowing agent is sodium carbonate / citric acid, food grade. The weight ratio of the raw material starch of the adhesive layer, the dispersant fine particles, the foaming agent (sodium carbonate/citric acid) and the solvent water is =1:0.08:0.0234 (0.0106/0.0128):6. The resulting coating viscosity was 1000 cps. The resulting coating was then applied to the surface of the kraft paper substrate by a bar coating process.

After the coating drying process, the adhesive layer is obtained by drying to form a film, and microcellular foaming of the adhesive layer structure is achieved. The film was coated on the surface of the substrate and dried by 180 ° C for 20 s to effect solvent evaporation and foaming of the foaming agent to obtain a fine structure, and the obtained coating was quantitatively 15 g/m ² . After the coating of the substrate, a microcellular foamed surface-modified substrate is obtained on the surface of the substrate layer 1 by a coating foaming process.

A polyethylene wax dispersion was used with a solids content of 35%. The surface of the microporous foamed surface-modified substrate was brushed by a brushing process, and after drying, the coating wax had a basis weight of 0.3 g/m ² . Thus, a new material having a lotus leaf bionic structure on the surface was obtained. In the hydrophobicity experiment, the contact angle was 159° and the rolling angle was 3°.

Finally, it should also be noted that the above list is merely a specific embodiment of the invention. It is apparent that the present invention is not limited to the above embodiment, and many variations are possible. All modifications that can be directly derived or conceived by those of ordinary skill in the art from the disclosure of the present invention are considered to be the scope of the present invention.

Claims

A new material having a hydrophobic function, characterized in that the surface of the new material is a lotus leaf bionic structure, including a substrate layer from bottom to top, a microcellular foamed modified adhesive layer, and a dispersion coating on the micro The waxy layer (3) on the foamed modified adhesive layer.
A method for preparing a novel material having a hydrophobic function according to claim 1, wherein the preparation steps are as follows:

1) mixing the adhesive layer raw material and the dispersant fine particles and the foaming agent in a certain ratio, adjusting the appropriate viscosity of the coating with a solvent, and coating on the surface of the substrate layer;

2) after coating the substrate layer, after coating the foaming process, obtaining a microcellular foaming modified adhesive layer on the surface of the substrate layer;

3) coating a wax-soluble (melting) liquid or a wax emulsion or a wax dispersion on the surface of the obtained microporous foam-modified adhesive layer by a coating process to form a wax-containing layer (3), and obtaining a surface having a lotus leaf after drying New materials for bionic structures.
The method for preparing a novel material having a hydrophobic function according to claim 2, wherein the dispersing agent is silica or titania fine particles having a particle size of from 1 nm to 10 μm.
The method for preparing a novel material having a hydrophobic function according to claim 2, wherein the foaming agent is composed of sodium carbonate/citric acid, sodium hydrogencarbonate, azodicarbonamide, azodicarboxylic acid. Any of diisopropyl ester, diethyl azodicarboxylate, and 4,4'-oxybenzobenzenesulfonyl hydrazide.
The method for preparing a new material having a hydrophobic function according to claim 2 or 3 or 4, wherein the adhesive layer raw material, the dispersant fine particles and the foaming agent are in a weight ratio of 1:0.01-0.4: The ratio of 0.01-0.1 is well mixed.
The method for preparing a new material having a hydrophobic function according to claim 2, wherein the adhesive layer coating process in the step 1) is a spray coating method, a roll coating method, a gravure coating method, and a bar coating method. Any one of the method, the brushing method, and the doctor blade method, and the coating process of the wax in the step 3) is any one of a spray coating method, a roll coating method, a gravure coating method, a bar coating method, a brush coating method, and a doctor blade method. One.
A method of preparing a novel material having a hydrophobic function according to claim 2 or 6, wherein In the step 2), the film is dried to form an adhesive layer, and the microporous foaming of the adhesive layer structure is realized.
The method for preparing a new material having a hydrophobic function according to claim 2 or 6, wherein the wax is a vegetable wax or a synthetic wax, and the vegetable wax is worm wax, wood wax, bayberry wax, China Any one of wax, wool wax, Japanese wax, rice bran wax, and beeswax, and the synthetic wax is any one of Fischer-Tropsch wax, polyethylene wax, polypropylene wax, ethylene-vinyl acetate copolymer wax, and oxidized polyethylene wax.
The method for preparing a new material having a hydrophobic function according to claim 2 or 6, wherein in the step 3), the coating wax has a basis weight of 0.01 to 10 g/m 2 .
The method for preparing a new material having a hydrophobic function according to claim 3, wherein the obtained new material having a lotus leaf bionic structure has a contact angle of more than 150° and a rolling angle of less than 10 in a hydrophobic experiment. °.