CN103408990B - Nano-particle super-hydrophobic self-cleaning wall paint and preparation method thereof - Google Patents

Abstract

The invention provides a preparation method of hydrophobic nano titanium dioxide, which comprises the following steps of 1), adding nano titanium dioxide into distilled water with the mass of 0.1-2% of that of the nano titanium dioxide, uniformly stirring, adding a silane coupling agent with the mass of 0.1-0.5% of that of the nano titanium dioxide, heating to 80-100 ℃, and uniformly stirring to obtain a first mixture; 2) adding a silicon-fluorine material accounting for 10-30% of the mass of the first mixture under slow stirring, and continuously stirring until the materials are uniformly mixed to obtain a second mixture; 3) and adding an emulsifier which accounts for 3-5% of the mass of the second mixture into the second mixture, emulsifying at a high speed for 90-120 minutes at 80-100 ℃, and cooling to obtain viscous nano titanium dioxide slurry, namely the hydrophobic nano titanium dioxide. The invention also provides a nano-particle super-hydrophobic self-cleaning wall paint containing the hydrophobic nano titanium dioxide and a preparation method thereof, and the nano-particle super-hydrophobic self-cleaning wall paint has a good hydrophobic function, has a stable contact angle with water of more than 150 degrees, has a rolling contact angle of less than 5 degrees, and has strong and long self-cleaning capability.

Description

A kind of nanoparticle superhydrophobic self-cleaning wall paint and preparation method thereof

technical field

The invention relates to the technical field of wall paint, in particular to a nanoparticle superhydrophobic self-cleaning wall paint and a preparation method thereof.

Background technique

According to bionics reports, there are two reasons for the superhydrophobic self-cleaning effect formed on the surface of the lotus leaf: one is that the surface of the lotus leaf is covered with a layer of low surface energy wax; the other is that the surface has a certain micro-nano binary roughness. sudden. The papillae with micro-nano binary roughness refer to the following two submicrostructures: one is a micron-scale protrusion, and the other is a nano-scale hair-like structure. The generation of the "lotus leaf effect" is closely related to the above two submicrostructures of the lotus leaf. The research found that the contact angle of the lotus leaf containing the two structures is 142°, while the contact angle of the lotus leaf containing only the micron structure is 126° . Based on this, the scientists believe that the nanoscale hairy structure increases the contact angle by 16°.

Scientific research has found that water droplets can only touch a few mastoids on the surface of the lotus leaf. The water shrinks into a ball under the action of surface tension and can roll easily. And when dust falls on the lotus leaf, the dust is only on the convex point of the lotus leaf, and the contact area with the lotus leaf is very small, so the adsorption force between the dust and the lotus leaf is very small, and the contact area between the dust and water droplets is large, and the dust There is a strong adsorption force between the particles and the water droplets, so they are easily taken away by the water droplets to achieve the self-cleaning function.

It can be seen that the hydrophobic effect is better, not only good hydrophobic materials are needed to prepare super-hydrophobic surfaces, but also nano-scale bumps need to be formed on super-hydrophobic surfaces. As a good model, the "lotus leaf effect" has been used in many fields. For example, the paint produced based on the lotus leaf effect can facilitate the cleaning of the surface of houses or buildings.

Many domestic manufacturers produce hydrophobic coatings, all of which use low surface energy materials to form a layer of hydrophobic surface on the surface of the substrate. Silicone materials and fluorine-containing materials are currently recognized as better materials for preparing hydrophobic surfaces. However, silicone resins have Si-O bonds as the main chain and have highly branched silicone polymers. Silicone polymers have the advantages of excellent heat resistance and weather resistance, but at the same time have the disadvantages of poor film-forming performance and poor solvent resistance. The structure of the fluororesin contains stable C-F bonds. The C-F bonds have excellent durability, weather resistance and chemical resistance due to their large energy, small F atomic radius and small polarizability of the bonds. Adhesion, low surface tension and low friction, as well as special surface properties such as water repellency, oil repellency, and surface self-cleaning. At the same time, organic fluorocarbon polymers also have some defects. Poor adhesion, poor wettability to pigments and fillers, poor low temperature resistance, etc. These shortcomings limit the popularization and application of fluororesin coatings.

How to overcome the shortcomings of the above-mentioned organosilicon materials and organofluorine materials, combine their advantages, and apply them to the preparation of superhydrophobic coatings is a hot and difficult point of current research. At the same time, there are few reports in the prior art that there is a coating that can not only form a hydrophobic surface, but also form nanoscale bumps on the hydrophobic surface like a lotus leaf.

Contents of the invention

In order to overcome the deficiencies in the prior art, the application provides a method for preparing hydrophobic nano-titanium dioxide, and a nanoparticle superhydrophobic self-cleaning wall paint containing the hydrophobic nano-titanium dioxide and a preparation method thereof, the nanoparticle superhydrophobic self-cleaning Wall paint can not only form a hydrophobic surface, but also form nano-scale bumps on the hydrophobic surface, so that it has excellent superhydrophobic properties. Its stable contact angle with water is greater than 150 degrees, and the rolling contact angle is less than 5 degrees. Has a strong and long-lasting self-cleaning ability.

The technical scheme of the present invention is as follows: a preparation method of hydrophobic nano-titanium dioxide, comprising the steps of:

1) Add nano-titanium dioxide to distilled water with a mass of 0.1%-2%, then add a silane coupling agent with a mass of 0.1%-0.5% of nano-titanium dioxide, heat to 80-100°C, and stir evenly to obtain mixture 1;

2) Add mixture 1 with 10%-30% silicon-fluorine material by mass under slow stirring, and continue stirring until uniformly mixed to obtain mixture 2;

3) Add an emulsifier of 3%-5% of the mass of mixture 2 to mixture 2, emulsify at 80-100°C for 90-120 minutes at a high speed, and cool to obtain a viscous nano-titanium dioxide slurry, which is hydrophobic nano-titanium dioxide.

The crystal form of nanometer titanium dioxide is rutile or anatase.

The silicon-fluorine material is an organic silicon-fluorine polymer or an epoxy-modified silicon-fluorine polymer.

The silicon-fluorine material is a fluorine-containing poly(meth)acrylate emulsion grafted and modified with long-chain polysiloxane, such as dimethylsiloxane-b-polyheptafluorobutyl methacrylate.

A nanoparticle super-hydrophobic self-cleaning wall paint, comprising the following components in parts by weight

The preparation method of described hydrophobic nano titanium dioxide particle comprises the steps:

1) Add nano-titanium dioxide to distilled water with a mass of 0.1%-2%, then add a silane coupling agent with a mass of 0.1%-0.5% of nano-titanium dioxide, heat to 80-100°C, and stir evenly to obtain mixture 1;

2) Add mixture 1 with 10%-30% silicon-fluorine material by mass under slow stirring, and continue stirring until uniformly mixed to obtain mixture 2;

3) Add an emulsifier of 3%-5% of the mass of mixture 2 to mixture 2, emulsify at 80-100°C for 90-120 minutes at a high speed, and cool to obtain a viscous nano-titanium dioxide slurry, which is hydrophobic nano-titanium dioxide.

The filler is any one or a mixture of diatomite, calcium carbonate, kaolin, magnesium silicate or talcum powder.

The film-forming resin is any one or a mixture of epoxy resins, acrylic resins, phenolic resins and polyester resins.

The auxiliary agent includes a crosslinking agent, an initiator and an accelerator; the crosslinking agent is any one or a mixture of several of styrene, methyl methacrylate or diallyl phthalate; the The initiator is any one or a mixture of benzoyl peroxide, butanone peroxide, tert-butyl hydroperoxide or isopropyl hydroperoxide; the accelerator is triethylamine, dimethylaniline Or any one or a mixture of several of diethylaniline.

The preparation method of described nanoparticle superhydrophobic self-cleaning wall paint, comprises the steps:

1) Weigh the hydrophobic nano-titanium dioxide, titanium dioxide, filler, film-forming resin, additives and distilled water according to the formula;

2) At room temperature, slowly add titanium dioxide and fillers into distilled water, stir until evenly mixed, and obtain mixture 3;

3) Slowly add film-forming resin and additives to mixture 1, and stir until evenly mixed to obtain mixture 4;

4) Slowly add hydrophobic nano-titanium dioxide into the mixture 4, and stir until evenly mixed to obtain the nano-particle super-hydrophobic self-cleaning wall paint.

Silicon-fluorine materials contain F-C bonds, Si-O bonds and Si-C bonds, and have low surface energy, so they have better hydrophobic effect. Therefore, nano-titanium dioxide particles are wrapped with silicon-fluorine materials, thereby giving nano-titanium dioxide good hydrophobic properties.

In the nanoparticle superhydrophobic self-cleaning wall paint of the present invention, when the film-forming substance in the paint dries, it will shrink, so that the nano-titanium dioxide particles wrapped by the silicon-fluorine material protrude on the surface of the paint film. At this time, the surface of the coating film formed by the purifying air wall paint of the present invention is very similar to the lotus leaf surface, not only has a super-hydrophobic surface, but also forms nano-scale bumps on the super-hydrophobic surface, thus having excellent super-hydrophobic function, After testing, the stable contact angle with water is greater than 150 degrees, and the rolling contact angle is less than 5 degrees.

The beneficial effects of the present invention are: the present invention uses silicon-fluorine material to wrap nano-titanium dioxide, combines the advantages of organic silicon material and organic fluorine material, forms stable hydrophobic nano-titanium dioxide particles, makes it have lower surface energy, and has better Hydrophobic properties. The coating containing nano-titanium dioxide coated with silicon-fluorine material shrinks when dry, so that the nano-titanium dioxide particles wrapped by silicon-fluorine material protrude on the surface of the coating film, thereby forming nano-scale bumps and achieving excellent super-hydrophobic self-cleaning function. The nanometer titanium dioxide and silicon fluorine materials used in the nanoparticle superhydrophobic self-cleaning wall paint of the present invention are tasteless, odorless, nontoxic, harmless to the human body, and will not cause other pollution; the raw material cost is low, the process is simple, and it is suitable for industrialization Production; wall paint particles have high strength, the coating film is not easy to be damaged, and has excellent weather resistance. .

Detailed ways

Example 1:

A nanoparticle super-hydrophobic self-cleaning wall paint, comprising the following components in parts by weight

The filler is diatomaceous earth.

The film-forming resin is epoxy resin.

The auxiliary agent includes a cross-linking agent, an initiator and an accelerator; the cross-linking agent is styrene; the initiator is benzoyl peroxide; and the accelerator is triethylamine.

The preparation method of described hydrophobic nano titanium dioxide particles is as follows:

1) Add 10kg of nano-titanium dioxide to 0.2kg of distilled water, stir evenly, then add 0.05kg of silane coupling agent, heat to 80°C, stir evenly to obtain mixture 1;

2) Add mixture 1 with 15% silicon-fluorine material by mass under slow stirring, and continue stirring until uniformly mixed to obtain mixture 2;

3) Add an emulsifier of 3% by mass of mixture 2 to mixture 2, emulsify at 100°C for 100 minutes at high speed, and cool to obtain a viscous nano-titanium dioxide slurry, which is hydrophobic nano-titanium dioxide.

The silicon-fluorine material is organic silicon-fluorine polymer, dimethylsiloxane-b-polyheptafluorobutyl methacrylate; the emulsifier is SDS.

The preparation method of described nanoparticle superhydrophobic self-cleaning wall paint, comprises the steps:

1) Weigh the hydrophobic nano-titanium dioxide, titanium dioxide, filler, film-forming resin, additives and distilled water according to the formula;

2) At room temperature, slowly add titanium dioxide and fillers into distilled water, stir until evenly mixed, and obtain mixture 3;

3) Slowly add film-forming resin and additives to mixture 3, and stir until evenly mixed to obtain mixture 4;

4) Slowly add hydrophobic nano-titanium dioxide into the mixture 4, and stir until uniformly mixed to obtain the nano-titanium dioxide photocatalytic air purification wall paint.

Example 2

A nanoparticle super-hydrophobic self-cleaning wall paint, comprising the following components in parts by weight

The filler is a mixture of magnesium silicate and talcum powder.

The film-forming resin is phenolic resin.

Described auxiliary agent comprises linking agent, initiator and promotor; Described linking agent is styrene and methyl methacrylate; Described initiator is benzoyl peroxide and tert-butyl hydroperoxide; Described The accelerator is diethylaniline.

The preparation method of described hydrophobic nano titanium dioxide particles is as follows:

1) Add 10kg of nano titanium dioxide to 0.1kg of distilled water, stir evenly, then add 0.03kg of silane coupling agent, heat to 90°C, stir evenly to obtain mixture 1;

2) Add mixture 1 with 30% silicon-fluorine material by mass under slow stirring, and continue stirring until uniformly mixed to obtain mixture 2;

3) Add 5% emulsifier SDS of mixture 2 to mixture 2, emulsify at 80°C for 120 minutes at high speed, and cool to obtain a viscous nano-titanium dioxide slurry, which is hydrophobic nano-titanium dioxide.

The silicon-fluorine material is an epoxy-modified silicon-fluorine polymer.

The preparation method of described nanoparticle superhydrophobic self-cleaning wall paint, comprises the steps:

1) Weigh the hydrophobic nano-titanium dioxide, titanium dioxide, filler, film-forming resin, additives and distilled water according to the formula;

2) At room temperature, slowly add titanium dioxide and fillers into distilled water, stir until evenly mixed, and obtain mixture 3;

3) Slowly add film-forming resin and additives to mixture 3, and stir until evenly mixed to obtain mixture 4;

4) Slowly add hydrophobic nano-titanium dioxide into the mixture 4, and stir until uniformly mixed to obtain the nano-titanium dioxide photocatalytic air purification wall paint.

Example 3

A nanoparticle super-hydrophobic self-cleaning wall paint, comprising the following components in parts by weight

The filler is talcum powder.

The film-forming resin is acrylic resin.

Described auxiliary agent comprises cross-linking agent, initiator and accelerator; Described cross-linking agent is diallyl phthalate; Described initiator is butanone peroxide; Described accelerator is triethylamine and diethylamine A mixture of anilines.

The preparation method of described hydrophobic nano titanium dioxide particles is as follows:

1) Add 10kg of nano-titanium dioxide to 0.01kg of distilled water, stir evenly, then add 0.01kg of silane coupling agent, heat to 100°C, stir evenly to obtain mixture 1;

2) Add mixture 1 with 10% silicon-fluorine material by mass under slow stirring, and continue stirring until uniformly mixed to obtain mixture 2;

3) Add 5% emulsifier SDS of mixture 2 to mixture 2, emulsify at 80°C for 120 minutes at high speed, and cool to obtain a viscous nano-titanium dioxide slurry, which is hydrophobic nano-titanium dioxide.

The silicon-fluorine material is organic silicon-fluorine polymer, dimethylsiloxane-b-polyheptafluorobutyl methacrylate.

The preparation method of described nanoparticle superhydrophobic self-cleaning wall paint, comprises the steps:

1) Weigh the hydrophobic nano-titanium dioxide, titanium dioxide, filler, film-forming resin, additives and distilled water according to the formula;

2) At room temperature, slowly add titanium dioxide and fillers into distilled water, stir until evenly mixed, and obtain mixture 1;

3) Slowly add film-forming resin and additives to mixture 1, and stir until evenly mixed to obtain mixture 2;

4) Slowly add hydrophobic nano-titanium dioxide into the mixture 2, and stir until evenly mixed to obtain the nano-titanium dioxide photocatalytic air purification wall paint.

The present invention is compared with existing superhydrophobic coatings, and the experimental method is as follows:

The static contact angle and rolling contact angle of the coating to water were measured with a JC2000C1 contact angle measuring instrument (Zhongchen Digital Technology Equipment Co., Ltd.).

Stain resistance is measured according to the fly ash method specified in GB/T 9780-1988 "Test Method for Stain Resistance of Architectural Coating Coatings". It is evaluated according to the reflectivity and divided into five grades. The test results are shown in the table below.

The specific experimental results are as follows:

It can be seen from the above table that, in addition to having: a larger static contact angle and a smaller rolling angle than ordinary superhydrophobic materials, the present invention has more excellent superhydrophobic performance; has better stain resistance; has more excellent Excellent weather resistance, adhesion, scrub resistance and simpler construction.

The above content is a further detailed description of the present invention in conjunction with specific preferred embodiments, and it cannot be assumed that the specific implementation of the present invention is limited to these descriptions. For those of ordinary skill in the technical field to which the present invention belongs, without departing from the concept of the present invention, its architecture can be flexible and changeable, and series of products can be derived. Just making some simple deductions or replacements should be deemed to belong to the patent protection scope of the present invention determined by the submitted claims.

Claims (10)

1. a preparation method of hydrophobic nano-titanium dioxide, is characterized in that, comprises the steps: 1) Add nano-titanium dioxide to distilled water with a mass of 0.1%-2%, then add a silane coupling agent with a mass of 0.1%-0.5% of nano-titanium dioxide, heat to 80-100°C, and stir evenly to obtain a mixture 1; 2) Add mixture 1 with 10%-30% silicon-fluorine material by mass under slow stirring, and continue stirring until uniformly mixed to obtain mixture 2; 3) Add an emulsifier of 3%-5% by mass of the mixture 2 to the mixture 2, emulsify at a high speed for 90-120 minutes at 80-100° C., and cool to obtain a viscous nano-titanium dioxide slurry, which is hydrophobic nano-titanium dioxide. 2. the preparation method of hydrophobic nano titanium dioxide as claimed in claim 1 is characterized in that, described nano titanium dioxide crystal form is rutile type or anatase type. 3. The preparation method of hydrophobic nano-titanium dioxide as claimed in claim 1, wherein the silicon-fluorine material is an organic silicon-fluorine polymer or an epoxy-modified silicon-fluorine polymer. 4. The preparation method of hydrophobic nano-titanium dioxide as claimed in claim 1 or 2, characterized in that, the silicon-fluorine material is dimethylsiloxane-b-polyheptafluorobutyl methacrylate. 5. the preparation method of hydrophobic nano titanium dioxide as claimed in claim 1 or 2, described emulsifying agent is sodium lauryl sulfate. 6. A nanoparticle superhydrophobic self-cleaning wall paint, characterized in that it comprises the following components in parts by weight The preparation method of described hydrophobic nano-titanium dioxide comprises the steps: 1) Add nano-titanium dioxide to distilled water with a mass of 0.1%-2%, then add a silane coupling agent with a mass of 0.1%-0.5% of nano-titanium dioxide, heat to 80-100°C, and stir evenly to obtain a mixture 1; 2) Add mixture 1 with 10%-30% silicon-fluorine material by mass under slow stirring, and continue stirring until uniformly mixed to obtain mixture 2; 3) Add an emulsifier of 3%-5% by mass of the mixture 2 to the mixture 2, emulsify at a high speed for 90-120 minutes at 80-100° C., and cool to obtain a viscous nano-titanium dioxide slurry, which is hydrophobic nano-titanium dioxide. 7. nanoparticle superhydrophobic self-cleaning wall paint as claimed in claim 6, is characterized in that, described filler is any one or the mixture of several in diatomite, calcium carbonate, kaolin, magnesium silicate or talcum powder . 8. nanoparticle superhydrophobic self-cleaning wall paint as claimed in claim 6, is characterized in that, described film-forming resin is epoxy resin, acrylic resin, phenolic resin, the mixture of any one or more in polyester resin . 9. nanoparticle superhydrophobic self-cleaning wall paint as claimed in claim 6, is characterized in that, described auxiliary agent comprises linking agent, initiator and promotor; Described linking agent is styrene, methyl methacrylate ester or diallyl phthalate or a mixture of several; the initiator is benzoyl peroxide, butanone peroxide, tert-butyl hydroperoxide or isopropyl hydroperoxide Any one or a mixture of several; the accelerator is any one or a mixture of several of triethylamine, dimethylaniline or diethylaniline. 10. the preparation method of nanoparticle superhydrophobic self-cleaning wall surface paint as any one of claim 6-9 is characterized in that, comprises the steps: 1), weighing described hydrophobic nano-titanium dioxide, titanium dioxide, filler, film-forming resin, auxiliary agent and distilled water according to the formula; 2) At room temperature, slowly add titanium dioxide and fillers into distilled water, stir until evenly mixed, and obtain mixture 3; 3), slowly add film-forming resin and additives to mixture 1, and stir until evenly mixed to obtain mixture 4; 4) Slowly add hydrophobic nano-titanium dioxide into the mixture 4, and stir until uniformly mixed to obtain the hydrophobic nano-titanium dioxide photocatalytic air purification wall paint.