CN107383943A - Water aluminum-silver slurry with clad and preparation method thereof - Google Patents

Abstract

The invention discloses water aluminum-silver slurry with clad and preparation method thereof, there is clad outside the water aluminum-silver slurry, clad is mesoporous silicon oxide and the response type acrylic acid in mesoporous silicon oxide surface grafting, and response type acrylic acid is the one or several kinds in hydroxy-ethyl acrylate, hydroxypropyl acrylate, hy-droxybutyl and the own ester of acrylic acid hydroxyl.The above-mentioned water aluminum-silver slurry with clad, synthesis technique is simple, easy to use, and without carrying out excessive pre-treatment to oiliness aluminum paste, and obtained water aluminum-silver slurry can keep aluminium powder brightness in itself and film performance.

Description

Water-based aluminum-silver paste with coating layer and preparation method thereof

technical field

The invention relates to the field of water-based aluminum-silver paste, in particular to a water-based aluminum-silver paste with a coating layer. In addition, the present invention also relates to a preparation method comprising the above-mentioned water-based aluminum-silver paste with a coating layer.

Background technique

Aluminum silver paste (aluminum powder) is one of the important metal pigments, because of its high bright metallic luster, it has been widely used in the coating industry, printing ink and plastic industry. At present, the annual domestic production and sales of aluminum silver paste is about 50,000 tons, of which 8,000 tons are imported from abroad and its products.

For a long time, in terms of coatings, aluminum silver paste has been used in solvent-based systems. In recent years, with the further development of the paint industry and the enhancement of people's awareness of environmental protection, the regulations on the discharge of toxic solvents into the atmosphere have become increasingly strict, and the production and development of low-pollution, pollution-free, and dust-free paint products have been highly valued. Using water instead of organic solvents, water-based coatings have become an inevitable trend in the development of the coatings industry. Since the state promulgated the "Volatile Organic Compounds Pollutant Discharge Pilot Measures" in June 2015, it was stipulated that VOC sewage charges will be collected from October 1, 2015, and the national and local government's policies to control air pollution have officially come into effect. Water-based aluminum silver paste is the general trend . In order to strictly limit VOC emissions, European and American countries have formulated corresponding environmental protection regulations to promote the development of coatings in the direction of high solid content, water-based, and powder-based coatings. It is understood that the water-based use of European intermediate coatings has reached more than 38%, and the water-based use of topcoats has reached 57%. There are more and more manufacturers applying water-based paint in China. Aluminum silver paste is the source of the flashing effect of paint. To achieve a good decorative effect, aluminum silver paste must be used. The furniture industry, automotive coatings, ink industry, and hardware and home appliance industry have begun to use a large number of aluminum pigments that can be used in water-based aluminum-silver pastes for water-based paints.

Since the aluminum silver paste will react with water in a water environment, 2Al+6H ₂ O→2Al(OH) ₃ +3H ₂ will generate H ₂ , which is the so-called "gassing" and cause various problems. The so-called water-based aluminum silver paste currently on the market is to prepare water-based aluminum silver paste by surface modification treatment on the traditional oily aluminum silver paste. There are two main types, physical protection law and chemical protection law.

The physical protection method is to wrap a layer of transparent resin on the surface of aluminum powder as a protective layer. For example, in-situ polymerization is used to coat the polystyrene resin layer on the surface of aluminum powder, but it should be known that the bonding force between polystyrene and aluminum powder is very weak, and the resin is easy to fall off from the surface of aluminum powder under high shear, and loses its resistance to the aluminum powder. Protective effect of aluminum powder. Moreover, the particle size of the aluminum powder is relatively large, and the conversion rate of the in-situ polymerization monomer using the aluminum powder as the matrix and the resin coating rate will not be too high. The high voltage conductivity is also poor. Application number 200810207593.3, using epoxy phosphate resin for coating, phosphate has a strong anchoring effect on aluminum powder, strong adsorption capacity, solves the problem of bonding with aluminum powder, but the matrix used is epoxy, epoxy There are many problems in the weather resistance and compatibility with water-based paint base materials, and the molecular weight of epoxy resin is low, and the ability to prevent the diffusion of water molecules is weak, which increases the corrosion of aluminum silver paste.

There are mainly two types of chemical protection methods: additive technology and coating technology. Additive technology is mainly through the addition of organic phosphorus compounds, such as Eckart's Stapa series, Siberline's AquasilBP/AN (Eckart, Siberline are the world's two largest suppliers of aluminum powder), but because of the addition of small molecular compounds, it is difficult to really protect aluminum Stability of the powder in water. Another side effect is that the properties of the coating (such as drying time, adhesion, moisture resistance) may be affected. Wrapping technology has also gone through two generations. The first generation uses insoluble chromium compounds (such as EckartHydrolux), which is also a good representative of preventing aluminum powder pitting corrosion. However, with the enhancement of environmental protection awareness, chromate is gradually eliminated due to its carcinogenic toxicity. The second generation is the more popular SiO ₂ coating, and some even add organic modification on the basis of SiO ₂ coating to improve the compatibility with the coating base material and enhance the adhesion, such as Japan Toyo's aluminum Powder processing technology, Eckart's Hydrolan series, but this kind of SiO ₂ coating technology is to add SiO ₂ coating layer on the basis of the original aluminum powder to achieve the effect of protecting aluminum powder, although it can prevent gas, heat and humidity resistance, weather resistance and Pipe cycle performance and other excellent comprehensive performance, but the SiO ₂ coating will inevitably affect the original brightness and sparkle of the aluminum powder, and it is easy to cause the agglomeration of the aluminum powder during the treatment process, and the manufacturing cost is also very expensive. Market promotion difficulty.

To sum up, the current technological development levels have their own advantages and disadvantages, and they all have one characteristic. Before formulating coatings, aluminum-silver paste manufacturers need to perform cumbersome processing on oil-based aluminum-silver paste in order to prepare water-based aluminum-silver paste. Aluminum paste for coating.

Contents of the invention

The invention provides a water-based aluminum-silver paste with a coating layer and a preparation method thereof to solve the existing technical problem that the _SiO2 coating layer affects the brightness and sparkle of aluminum powder.

The technical scheme that the present invention adopts is as follows:

One aspect of the present invention provides a water-based aluminum-silver paste with a coating layer. The water-based aluminum-silver paste has a coating layer outside, and the coating layer is mesoporous silica coated on the aluminum sheet of the water-based aluminum-silver paste. Reactive acrylic acid grafted on the surface of mesoporous silica, wherein the reactive acrylic acid is one or more of hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxybutyl acrylate and hydroxyhexyl acrylate.

Further, the amount of reactive acrylic acid corresponding to the amount of mesoporous silica-coated aluminum sheet and reactive acrylic acid per gram of mesoporous silica-coated aluminum sheet is 2-5 mmol; wherein the mesoporous silica In the coated aluminum sheet, the mass ratio of the aluminum sheet to the mesoporous silicon dioxide is (1-10): (0.29-0.43).

Further, the mesoporous silica is mainly prepared by using hexadecyltrimethylammonium bromide as a templating agent and ethyl orthosilicate as a silicon source.

Another aspect of the present invention provides a kind of preparation method of the above-mentioned water-based aluminum-silver paste with coating layer, comprising the following steps:

With aluminum silver paste as the carrier, hexadecyltrimethylammonium bromide as the template, ethyl orthosilicate as the silicon source, ethanol and water as the solvent, and ammonia as the catalyst, the reaction is carried out at 10-50°C, and the reaction product is After separation and drying, an aluminum sheet coated with mesoporous silica is obtained;

The aluminum sheet coated with mesoporous silica is refluxed in an ethanol aqueous solution to remove the template agent, and reactive acrylic acid is added to react to obtain a water-based aluminum silver paste with a coating layer.

Further, the step of removing the templating agent from the aluminum sheet coated with mesoporous silica and reacting with reactive acrylic acid includes:

The mesoporous silica-coated aluminum sheet is stirred and refluxed in ethanol aqueous solution at 40-100°C for 1-12 hours; the reactive acrylic acid and water are mixed and added dropwise to the mesoporous silica-coated aluminum sheet solution Stir the reaction for 1-12 hours.

Further, the amount of reactive acrylic acid added per gram of mesoporous silica is 2-5 mmol, and the stirring speed after adding reactive acrylic acid is 10000 r/min.

Further, the reaction for preparing the aluminum sheet coated with mesoporous silica is specifically:

Mix aluminum silver paste, tetraethyl orthosilicate, hexadecyltrimethylammonium bromide, ethanol and water, stir for 10-15 minutes, add ammonia water dropwise, and continue to stir and react at 10-50°C for 2-4 hours .

Further, the mass ratio of aluminum silver paste, cetyltrimethylammonium bromide, tetraethyl orthosilicate, ethanol, water and ammonia water is (1～10):(0.2～0.3):(1～1.5) :(20～30):(50～70):(0.9～1.8).

Further, the drying temperature is 55-65°C.

The invention has the following beneficial effects: the above-mentioned water-based aluminum-silver paste with a coating layer has a simple synthesis process, is convenient to use, does not need to carry out too much pretreatment on the oil-based aluminum-silver paste, and the prepared water-based aluminum-silver paste can keep aluminum powder The brightness and coating performance of itself.

In addition to the objects, features and advantages described above, the present invention has other objects, features and advantages. Hereinafter, the present invention will be described in further detail with reference to the drawings.

Description of drawings

The accompanying drawings constituting a part of this application are used to provide further understanding of the present invention, and the schematic embodiments and descriptions of the present invention are used to explain the present invention, and do not constitute an improper limitation of the present invention. In the attached picture:

Fig. 1 is the particle size distribution diagram of the water-based aluminum-silver paste with coating layer according to the preferred embodiment of the present invention.

detailed description

The embodiments of the present invention will be described in detail below with reference to the accompanying drawings, but the present invention can be implemented in many different ways defined and covered by the claims.

A preferred embodiment of the present invention provides a water-based aluminum-silver paste with a coating layer, the water-based aluminum-silver paste has a coating layer outside, and the coating layer is mesoporous silica coated on the aluminum sheet of the water-based aluminum-silver paste and reactive acrylic acid grafted on the surface of the mesoporous silica, wherein the reactive acrylic acid is one or more of hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxybutyl acrylate and hydroxyhexyl acrylate.

The cladding layer is mesoporous silicon dioxide and reactive acrylic acid grafted on the surface of the mesoporous silicon dioxide. The porous structure of mesoporous silica can transmit light, and there are reactive active points in the pores, which facilitate the reaction of reactive acrylic polymers on the basis of its porous structure. Therefore, the amount of reactive acrylic acid introduced is less, so that the water-based aluminum silver paste can maintain the brightness and sparkle of the raw material. At the same time, reactive acrylic acid can make the product have good water dispersion properties. In addition, after the acrylic material is polymerized, it has a better gloss.

Mesoporous silica is a silicon dioxide material with a pore size ranging from 2 to 50 nanometers in diameter. Mesoporous nano-silica can form organic-inorganic hybrid materials with organic or polymer materials, so that it can exert its own small size effect, surface and interface effect, and quantum size effect. At the same time, different modification methods can endow materials with various other properties. Mesoporous silicas (MSNs) have been flourishing in the fields of chemical engineering and drug carriers due to their high specific surface area, high pore volume, and good biocompatibility. The hollow mesoporous silica surface is chemically inert, but the polymer-modified mesoporous silica hybrid material not only retains the structural advantages of mesoporous silica, but also combines the chemical diversity and long-chain structure of the polymer. features.

The polymer reactant selected in the present invention is reactive acrylic acid. The reactive acrylic acid is a kind of homopolymer or copolymer of acrylic acid with different molecular weight, which only slightly reduces the surface tension of the paint, and can balance the difference in surface tension of the paint film to obtain a truly flat, mirror-like paint film surface. This type of substance acts as a leveling agent. If the molecular weight is high enough, this type of leveling agent also has the effect of degassing and defoaming. Acrylic leveling agents with reactive functional groups can provide good leveling without haze and decrease surface hardness, and sometimes increase surface hardness.

The above-mentioned water-based aluminum-silver paste with a coating layer has a simple synthesis process and is convenient to use, without excessive pretreatment on the oil-based aluminum-silver paste, and the prepared water-based aluminum-silver paste can maintain the brightness and coating performance of the aluminum powder itself .

Further, the amount of reactive acrylic acid corresponding to the amount of mesoporous silica-coated aluminum sheet and reactive acrylic acid per gram of mesoporous silica-coated aluminum sheet is 2-5 mmol; wherein the mesoporous silica In the coated aluminum sheet, the mass ratio of the aluminum sheet to the mesoporous silicon dioxide is (1-10): (0.29-0.43).

Further, the mesoporous silica is mainly prepared by using hexadecyltrimethylammonium bromide as a templating agent and ethyl orthosilicate as a silicon source.

Hexadecyltrimethylammonium bromide itself has its own active group trimethoxysilane, which has been introduced when the polymer is synthesized, omitting the step of secondary modification of the polymer.

Another aspect of the present invention provides the preparation method of the above-mentioned water-based aluminum-silver paste with coating, comprising the following steps:

With aluminum silver paste as the carrier, hexadecyltrimethylammonium bromide as the template, ethyl orthosilicate as the silicon source, ethanol and water as the solvent, and ammonia as the catalyst, the reaction is carried out at 10-50°C, and the reaction product is After separation and drying, an aluminum sheet coated with mesoporous silica is obtained;

The aluminum sheet coated with mesoporous silica is refluxed in an ethanol aqueous solution to remove the template agent, and reactive acrylic acid is added to react to obtain a water-based aluminum silver paste with a coating layer.

The main component of the aluminum-silver paste is aluminum flakes. In the preparation method of the water-based aluminum-silver paste coating material of the present application, ordinary oil-based aluminum-silver paste or water-based aluminum-silver paste can be used as raw materials.

The polymer reactant selected in the present invention is reactive acrylic acid. The reactive acrylic acid is a kind of homopolymer or copolymer of acrylic acid with different molecular weight, which only slightly reduces the surface tension of the paint, and can balance the difference in surface tension of the paint film to obtain a truly flat, mirror-like paint film surface.

There are three main methods for polymer modification on the surface of mesoporous silica: physical adsorption, polymer grafting (graft to) and surface-initiated polymerization (graft from). Among them, the preparation method of the physical adsorption method is simple, but the obtained hybrid material is easy to fall off because there is no chemical bond between the two. The preparation methods of graft to and graft from are relatively complicated, but there is a covalent bond between mesoporous silica and the polymer, and the stability is high, so it is widely used. The difference between the two is: graft to uses active groups of existing polymers to connect to the surface of mesoporous silica; graft from uses the initiation point modified on the surface of mesoporous silica to directly initiate monomer polymerization.

The present invention adopts graft to method to prepare another aspect of the present invention provides the preparation method of the water-based aluminum-silver paste with coating layer, active group trimethoxysilane is initiator itself in the present invention, when polymer is synthesized It has been introduced, omitting the step of polymer secondary modification.

Further, the step of removing the templating agent from the aluminum sheet coated with mesoporous silica and reacting with reactive acrylic acid includes:

The mesoporous silica-coated aluminum sheet is stirred and refluxed in ethanol aqueous solution at 40-100°C for 1-12 hours; the reactive acrylic acid and water are mixed and added dropwise to the mesoporous silica-coated aluminum sheet solution Stir the reaction for 1-12 hours.

The aluminum sheet coated with mesoporous silica is stirred and refluxed at 40-100° C. for 1-12 hours in an ethanol aqueous solution to remove the template agent. The conditions are mild and the aluminum sheet is not easily oxidized.

Further, the amount of reactive acrylic acid added per gram of mesoporous silica is 2-5 mmol, and the stirring speed after adding reactive acrylic acid is 10000 r/min.

Further, the reaction for preparing the aluminum sheet coated with mesoporous silica is specifically:

Mix aluminum silver paste, tetraethyl orthosilicate, hexadecyltrimethylammonium bromide, ethanol and water, stir for 10-15 minutes, add ammonia water dropwise, and continue to stir and react at 10-50°C for 2-4 hours .

Further, the mass ratio of aluminum silver paste, cetyltrimethylammonium bromide, tetraethyl orthosilicate, ethanol, water and ammonia water is (1～10):(0.2～0.3):(1～1.5) :(20～30):(50～70):(0.9～1.8).

Further, the drying temperature is 55-65°C.

Example 1

Preparation of A mesoporous silica-coated aluminum sheet

Mix 1g of aluminum silver paste, 0.2g of cetyltrimethylammonium bromide, 1.25mL of tetraethyl orthosilicate (TEOS), 25mL of ethanol and 66.23mL of deionized water, and stir vigorously for 15 minutes to make the mixture well dispersed , add dropwise 1.25mL ammonia water (mass percentage concentration: 25-28%), continue to stir and react at 30°C for 3h, and centrifuge the precipitate; vacuum-dry to obtain the product which is a hollow mesoporous silica-coated aluminum sheet. In the above steps, the mass ratio of each substance is: the mass ratio of aluminum silver paste, cetyltrimethylammonium bromide, tetraethyl orthosilicate, ethanol, deionized water, and ammonia water is 1:0.2:1.16: 19.72:66.23:1.18.

B Polymer-modified mesoporous silica-coated aluminum sheet

After the mesoporous silica-coated aluminum flakes were centrifuged and dried, they were dispersed in ethanol aqueous solution, the reaction bottle was sealed at 78°C and stirred for 12 hours, and 5ml of hydroxyethyl acrylate was dissolved in 5mL of water, and then added dropwise to the mesoporous silica In the coated aluminum flake solution, the reaction bottle was sealed at 78°C and stirred for 6 hours. The resulting dispersion was centrifuged at 10,000 r/min, and washed with deionized water for 3 times to remove ungrafted polymers to obtain the product.

Example 2

Preparation of A mesoporous silica-coated aluminum sheet

Mix 10g of aluminum silver paste, 0.3g of cetyltrimethylammonium bromide, 1.62mL of tetraethyl orthosilicate (TEOS), 38mL of ethanol and 50mL of deionized water, and stir vigorously for 10 minutes to make the mixed solution well dispersed. Add 1.91 mL of ammonia water (25-28% by mass) dropwise, continue to stir and react at 50° C. for 2 h, and centrifuge to separate the precipitate; vacuum-dry to obtain the product, which is a hollow mesoporous silica-coated aluminum sheet. In the above steps, the mass ratio of each substance is: the mass ratio of aluminum silver paste, cetyltrimethylammonium bromide, tetraethyl orthosilicate, ethanol, deionized water, and ammonia water is 10:0.3:1.5: 30:50:1.8.

B Polymer-modified mesoporous silica-coated aluminum sheet

After the mesoporous silica-coated aluminum flakes were centrifuged and dried, they were dispersed in ethanol aqueous solution, the reaction bottle was sealed at 40°C and stirred for 1 hour, and 8ml of hydroxypropyl acrylate was dissolved in 5mL of water, and then added dropwise to the mesoporous silica In the coated aluminum flake solution, the reaction bottle was sealed at 100°C and stirred for 1 hour. The obtained dispersion was centrifuged at 10,000 r/min, and washed with deionized water for 3 times to remove ungrafted polymers to obtain the product.

Example 3

Preparation of A mesoporous silica-coated aluminum sheet

Mix 5g of aluminum silver paste, 0.25g of cetyltrimethylammonium bromide, 1.30mL of tetraethyl orthosilicate (TEOS), 32mL of ethanol and 70mL of deionized water, and stir vigorously for 10 minutes to disperse the mixture well. Add 1.59mL of ammonia water (25-28% by mass) dropwise, continue to stir and react at 10°C for 4 hours, and centrifuge to separate the precipitate; vacuum-dry to obtain the product, which is a hollow mesoporous silica-coated aluminum sheet. In the above steps, the mass ratio of each substance is: the mass ratio of aluminum silver paste, cetyltrimethylammonium bromide, tetraethyl orthosilicate, ethanol, deionized water, and ammonia water is 5:0.25:1.2: 25:70:1.5.

B Polymer-modified mesoporous silica-coated aluminum sheet

After the mesoporous silica-coated aluminum flakes were centrifuged and dried, they were dispersed in ethanol aqueous solution, the reaction bottle was sealed and stirred at 100°C for 6 hours, and 10ml of hydroxybutyl acrylate was dissolved in 5mL of water, and then added dropwise to the mesoporous silica In the coated aluminum flake solution, the reaction bottle was sealed at 40°C and stirred for 12 hours. The obtained dispersion was centrifuged at 10,000 r/min, and washed with deionized water for 3 times to remove ungrafted polymers to obtain the product.

data representation

The product solid content of the water-based aluminum-silver paste with coating layer that embodiment 1 makes is 60%, median diameter: 10.02um, particle diameter and its distribution are shown in the following table and Fig. 1:

Table 1 has the particle size distribution table of the water-based aluminum-silver paste of coating layer

Get respectively the raw material 10g oily aluminum-silver paste A of embodiment 1 and the prepared water-based aluminum-silver paste B with a coating layer, both of which have a particle diameter of 10 μm, and mix them with 10g ethylene glycol butyl ether, 30g After the butanol is mixed, soak for half an hour, add 50g acrylate phosphate while stirring, and continue stirring for half an hour. While stirring, add 2g of BYK180 wetting and dispersing agent, stir for 10 minutes, and then use 3g of dimethylethanolamine to adjust the pH of the aluminum-silver paste dispersion to 8.2 to prepare the corresponding coating.

The paint prepared above is sprayed by air on the electrophoretic steel plate at a relative humidity of 60-80% and a temperature of 25°C. Flash dry for 3-5 minutes, pre-bake at 80°C for 3-5 minutes, film thickness is 10-20 μm, then spray the matching varnish of 30-50 μm, bake at 80°C for 20 minutes, and measure its color data.

Embodiment 2～3 carries out corresponding operation. Its color data of A, B of each embodiment are as shown in table 2:

Table 2 The coating lightness data of oily aluminum-silver paste A and water-based aluminum-silver paste B of the cladding layer

Compared with the oily aluminum silver paste A, the water-based aluminum-silver paste B with a coating layer has a small decrease in the L value such as 15°, 25°, and 45° angles, but the decrease of B is not much compared with A, indicating that the water-based aluminum-silver paste with a coating layer The brightness and sparkle of aluminum silver paste B can be maintained.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and changes. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims (9)

1. a kind of water aluminum-silver slurry with clad, it is characterised in that there is clad, the bag outside the water aluminum-silver slurry Coating is the mesoporous silicon oxide being coated on the aluminium flake of the water aluminum-silver slurry and connect on the surface of the mesoporous silicon oxide The response type acrylic acid of branch, the response type acrylic acid are hydroxy-ethyl acrylate, hydroxypropyl acrylate, hy-droxybutyl and third One or several kinds in the own ester of olefin(e) acid hydroxyl.

2. water aluminum-silver slurry covering material according to claim 1, it is characterised in that the mesoporous silicon oxide cladding Aluminium flake with and the response type acrylic acid dosage for every gram of mesoporous silicon oxide cladding the corresponding response type third of aluminium flake The amount of olefin(e) acid is 2~5mmol；Wherein in the aluminium flake of mesoporous silicon oxide cladding, the aluminium flake and the meso-porous titanium dioxide are siliceous It is (1~10) to measure ratio：(0.29~0.43).

3. water aluminum-silver slurry covering material according to claim 1 or 2, it is characterised in that the mesoporous silicon oxide master To be template by cetyl trimethylammonium bromide, tetraethyl orthosilicate be that silicon source is prepared.

It is 4. a kind of such as the preparation method of the water aluminum-silver slurry according to any one of claims 1 to 3 with clad, its feature It is, comprises the following steps：

Using aluminum paste as carrier, cetyl trimethylammonium bromide is template, and tetraethyl orthosilicate is silicon source, and ethanol, water are molten Agent, ammoniacal liquor are catalyst, are reacted at 10~50 DEG C, after reaction product separation is dried, obtain the aluminium flake of mesoporous silicon oxide cladding；

The aluminium flake that the mesoporous silicon oxide coats is flowed back removed template method in ethanol water, adds response type acrylic acid Reaction obtains the water aluminum-silver slurry with clad.

5. the preparation method of the water aluminum-silver slurry according to claim 4 with clad, it is characterised in that described mesoporous The aluminium flake removed template method of coated with silica, include with the step of response type propylene acid reaction：

The aluminium flake of the mesoporous silicon oxide cladding is stirred at reflux 1~12h of reaction in ethanol water at 40~100 DEG C； The response type acrylic acid and water are mixed, it is small to be added drop-wise to stirring reaction 1~12 in the aluminium flake solution of mesoporous silicon oxide cladding When.

6. the preparation method of water aluminum-silver slurry covering material according to claim 5, it is characterised in that every gram described mesoporous The amount for the response type acrylic acid that silica adds is 2~5mmol, and the mixing speed added after the response type acrylic acid is 10000r/min。

7. the preparation method of the water aluminum-silver slurry according to claim 4 with clad, it is characterised in that described in preparation The reaction of aluminium flake of mesoporous silicon oxide cladding is specially：

Aluminum paste, tetraethyl orthosilicate, cetyl trimethylammonium bromide, second alcohol and water are mixed, stirring is dripped after 10~15 minutes Add the ammoniacal liquor, continue stirring reaction at 10~50 DEG C 2~4 hours.

8. the preparation method of water aluminum-silver slurry covering material according to claim 7, it is characterised in that the aluminum paste, The cetyl trimethylammonium bromide, the tetraethyl orthosilicate, the ethanol, the mass ratio of the water and the ammoniacal liquor are (1 ~10)：(0.2~0.3):(1~1.5):(20~30)：(50~70):(0.9~1.8).

9. the preparation method of the water aluminum-silver slurry with clad according to any one of claim 4~8, its feature exist In the drying temperature is 55~65 DEG C.