CN111057430A

CN111057430A - Universal composition with good covering property and preparation method and application thereof

Info

Publication number: CN111057430A
Application number: CN202010000987.2A
Authority: CN
Inventors: 俞健
Original assignee: Langfang Nippon Paint Co ltd
Current assignee: Langfang Nippon Paint Co ltd
Priority date: 2020-01-02
Filing date: 2020-01-02
Publication date: 2020-04-24

Abstract

The invention discloses a universal composition with good covering property, which comprises the following raw materials in percentage by weight: 4-12% of aluminum powder, 4-8% of acrylic resin, 30-50% of dispersing aid and 30-55% of solvent. The composition has good covering property and light ray transmission resistance, and can be well applied to solvent type and water-based polymer film intermediate coating systems. The invention also discloses a preparation method and application of the composition.

Description

Universal composition with good covering property and preparation method and application thereof

Technical Field

The invention relates to the technical field of preparation of coatings. More particularly, it relates to a composition of general type with good hiding power, its preparation method and application.

Background

The existing water-based polymer material contains a large amount of water, the evaporation heat of the water is far higher than that of other solvents, the volatility is poor, so the wet film solid content after construction is low, although the wet film solid content can be improved by additionally baking (at 80 ℃ for 5 minutes) after construction, the baking process is increased, the length of a production line, personnel, energy consumption and CO are increased₂The thickness of the water-based intermediate coating is reduced, the atomizing condition is improved to atomize the coating to smaller particles during construction, the specific surface area is increased to enhance volatilization, and the coating is kept stand at normal temperature, so that the problems of pinholes, light loss, mixed layers and the like of the coating caused by low solid content of the intermediate-wet coating after construction are solved.

Although solvent-soluble high-molecular material is more volatile and has better heat of evaporation than water, the problem of coating is not easy to occur, but the temperature, humidity and construction are difficult to occur in different areas of wide factories in ChinaThe coating problem often occurs due to large differences in environment and the like; at the same time, the environmental protection requirements are more and more strict, and automobile manufacturers all hope to reduce VOC and CO₂Emission, so that the reduction of the thickness of the middle coating film is the improvement trend of the current automobile coating film.

The middle coating is used for providing good covering property and light ray transmission resistance in the automobile composite coating, the reduction of the film thickness inevitably causes poorer covering property and light ray transmission resistance, and the reduction of the covering property causes polishing marks and appearance reduction of the automobile coating film; the reduction of light transmittance causes ultraviolet rays to reach the electrophoretic layer more easily, and epoxy resin is decomposed, the coating film is pulverized, the corrosion resistance is reduced, the automobile is rusted, and the service life is reduced in electrophoresis, so that the intermediate coating needs to be improved, but the existing pigment cannot be compatible with the condition of low film thickness.

Meanwhile, with the improvement of living standard, consumers have more requirements on the color of the automobile, such as brighter white, more brilliant red, more transparent blue and the like, but the light transmittance and the covering property of the colors are poorer than the prior colors, so that the color paint needs to be coated to make up for the deficiency of the color paint, and the requirements on the light transmittance and the covering property of the middle coating are higher.

In view of the above, there is a need to develop a functional material with good covering property and light transmission resistance for use in an automotive intermediate coating system.

Disclosure of Invention

Based on the above facts, the first object of the present invention is to provide a composition with good covering property of general purpose type, which has good covering property and light ray penetration resistance, and good guarantee of coating film appearance and stone chip resistance, and can be well applied in solvent-based and water-based polymer film intermediate coating systems.

A second object of the invention is to provide a process for the preparation of a composition of the general type having good hiding power.

A third object of the invention is to provide the use of a composition of the general type having good hiding properties.

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

a general composition with good covering performance comprises the following raw materials in percentage by weight:

further, the aluminum powder is non-floating silver element type aluminum powder; the particle size D90 of the aluminum powder is 10-20 μm; the thickness-diameter ratio of the aluminum powder is 60:1-80: 1.

Further, the acrylic resin is selected from acrylic resins containing a phosphoric acid group.

Further, the dispersing aid is selected from a pigment affinity group-containing dispersant.

Further, the solvent is selected from one or more of alcohol ether solvents and ester solvents.

Further, in the raw materials, the mass ratio of the aluminum powder to the acrylic resin is (0.5-2.5): 1.

further, the raw materials also comprise 0-2% of ultraviolet absorbent in percentage by weight; preferably, the raw materials contain 0% or 0.01-2% of ultraviolet absorbent by weight percentage.

Further, in the composition, the aluminum powder is wrapped in the acrylic resin.

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

a method for preparing a composition with good covering property of general type, comprising the following steps:

soaking the aluminum powder by using a solvent to disperse the aluminum powder;

adding acrylic resin to wrap the aluminum powder by the acrylic resin;

adding a dispersing aid.

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

the application of a general composition with good covering property in water paint or solvent paint.

Further, the water-based paint or the solvent-based paint is a water-based primer surfacer or a solvent-based primer surfacer.

Further, the addition amount of the composition in the water-based coating or the solvent-based coating is 1-20% by weight percentage.

The invention has the following beneficial effects:

compared with the existing carbon ink, titanium dioxide, barium sulfate and the like commonly used for middle coating, the composition provided by the invention has better light ray transmission resistance and covering property under the condition of not increasing the thickness of the middle coating, can be directly added into the middle coating during high-speed dispersion, does not need to be sanded to prepare color paste, has simple preparation process, less required equipment and short time, can be produced according to required time and amount, saves time and inventory and reduces cost. Because the surface is flat and smooth, the ultraviolet light absorber can be added according to the requirements of weather resistance and light transmittance resistance; compared with the existing pigment with a porous surface, the ultraviolet light absorbent cannot achieve good weather resistance and light transmittance resistance, and is obviously improved; and can ensure the qualified performance of covering power, light transmittance and the like only by adding the composition under the condition of reducing the thickness of the middle coating film, thereby achieving the purpose of reducing VOC and CO₂The purpose of discharging.

Drawings

The following describes embodiments of the present invention in further detail with reference to the accompanying drawings.

Fig. 1 shows ultraviolet spectra for different ultraviolet absorber concentrations.

Detailed Description

In order to more clearly illustrate the invention, the invention is further described below with reference to preferred embodiments and the accompanying drawings. Similar parts in the figures are denoted by the same reference numerals. It is to be understood by persons skilled in the art that the following detailed description is illustrative and not restrictive, and is not to be taken as limiting the scope of the invention.

One embodiment of the invention provides a general composition with good covering property, which comprises the following raw materials in percentage by weight:

the composition is used in a water-based primer surfacer or a solvent-based primer surfacer, and can well overcome the problem that the traditional automobile primer surfacer system (such as the water-based primer surfacer or the solvent-based primer surfacer) has poor paint covering property and light transmittance resistance due to low film thickness (the composition has good light transmittance resistance and covering power due to the fact that the composition absorbs or reflects all wavelength ranges of ultraviolet light and visible light at the same time), further effectively prevent the automobile coating from being scratched and reduced in appearance, prevent ultraviolet rays from reaching an electrophoretic layer more easily due to the reduction of light transmittance, and solve the problems of epoxy resin decomposition, coating pulverization, reduced corrosion resistance, automobile rusting, reduced service life and the like in electrophoresis.

In the composition, aluminum powder is uniformly dispersed and wrapped in acrylic resin. Further, the problem that hydrogen is generated by the reaction of water and aluminum in a water-based paint system and explosion is generated when fire occurs can be solved.

The particle size range of the aluminum powder is wide, and the low-particle-size aluminum powder needs to be selected under the condition of low film thickness of the intermediate coating system, but the particle size cannot be too low because the light transmittance resistance is reduced due to the too low particle size of the aluminum powder; and when the automobile coating is used, the automobile coating can be circulated in a production line circulation system for a long time (1-3 months or so), so that the requirement on the anti-circulation performance of the middle coating and the materials in the middle coating is high, and certain requirements on the shape and the particle size ratio of aluminum powder are met, so that the good anti-circulation performance of the middle coating is ensured. In a preferred example, the aluminum powder is non-leafing silver element type aluminum powder; the particle size D90 of the aluminum powder is 10-20 μm, preferably 12-20 μm; the thickness-diameter ratio of the aluminum powder is 60:1-80: 1. The non-floating aluminum powder can be uniformly distributed in the coating film, so that the color and the self performance of the coating film are uniform and stable, and the coating film has good adhesion with the upper layer and the lower layer, and the performance of the composite coating is ensured. The particle size D90 is 10-20um, is less than 10nm, and the light transmittance resistance is reduced and is higher than 20um, which exceeds the requirements of the middle coating film thickness and fineness and the specification of the filter material of the production line. The aluminum powder is in a silver element shape, so that the deformation, the crushing degree and the quantity of the aluminum powder can be reduced due to long-time circulation in a production line circulation system, and the abnormal color and quality are avoided. When the thickness-diameter ratio is lower than 60:1, the covering property is too poor and higher than 80:1, the aluminum powder is too thin, and the aluminum powder is easy to deform and break after long-time circulation in a circulation system. Exemplary aluminum powders include, but are not limited to, one or more of 6315NS, FD-5090, ALUMINIUM PASTE 7640NS, MH-8801.

In a preferred example, the addition amount of the aluminum powder in the raw materials is 4-10% by weight.

In still another preferred example, in the raw materials, the mass ratio of the aluminum powder to the acrylic resin is (0.5-2.5): 1. in this case, the covering property against visible light and ultraviolet light is more excellent. The obtained intermediate coating has good color, appearance and stone chip resistance.

The acrylic resin suitable for the present embodiment is selected from acrylic resins containing a phosphoric group. The phosphate group and the aluminum powder are well combined, so that the acrylic acid can well wrap the aluminum powder. Exemplary acrylic resins include, but are not limited to, one or more selected from DIANAL HR-2077, ACS-1212, ACS-1016, DIANAL HR-2077.

In a preferred example, the acrylic resin is added to the raw material in an amount including, but not limited to, 4.5-8%, 4.8-8%, 5-8%, 4.8-7.2%, etc., in weight percent.

Dispersing aids suitable for use in this embodiment include, but are not limited to, those selected from pigment affinity group-containing dispersants. Illustratively, the dispersing aid includes, but is not limited to, one or more selected from BYK-DISPERBYK-192, BYK-DISPERBYK-182, SURFYNOLS 440.

Solvents suitable for use in this embodiment include, but are not limited to, solvents selected from alcohol ethers or esters. Illustratively, the solvent includes, but is not limited to, one or more of isopropanol, butyl acetate, ethylene glycol isooctyl ether. In a preferred example, the solvent is added to the raw materials in an amount of 30 to 50% by weight.

In a preferred example, the raw material also comprises 0-2% of ultraviolet absorbent; preferably, the raw materials contain 0% or 0.01-2% of ultraviolet absorbent by weight percentage. The addition of the ultraviolet absorber can further improve the weather resistance and the light transmittance resistance. Exemplary ultraviolet light absorbers include, but are not limited to, TINUVIN 384-2, TINUVIN 123, TINUVIN477, and the like.

Yet another embodiment of the present invention provides a method for preparing a composition with good hiding properties of the general type as described above, comprising the steps of:

soaking the aluminum powder by using a solvent to disperse the aluminum powder;

adding acrylic resin to wrap the aluminum powder by the acrylic resin;

adding a dispersing aid.

Yet another embodiment of the present invention provides the use of a composition as described above in a water borne coating or a solvent borne coating.

Further, the addition amount of the composition in the water-based coating or the solvent-based coating is 1-20% by weight percentage. Illustratively, the amount added includes, but is not limited to, 1-10%, 5-10%, 1-5%, etc.

The technical solution of the present invention is described below with reference to some specific examples:

examples of light transmission resistance test methods and requirements:

the test method comprises the following steps:

independently spraying each coating on a plastic film, baking the coating, then removing the coating, testing the thickness of the coating, and taking an average value for recording; on the light transmission instrument, the wavelength range to be tested is selected, the light transmission rate is measured, the test result is sorted and calculated according to the requirement, and a test report is submitted.

The light transmission resistance requirements are shown in table 1 below:

TABLE 1 light transmittance resistance requirement

The requirement is that the minimum film thickness required by each coating is 58 percent, and the light transmittance resistance meets the requirement.

The wavelength ranges of the respective lights are shown in table 2 below.

TABLE 2 wavelength ranges corresponding to different light rays

From the above data it follows that: the coating film must satisfy both ultraviolet and visible light wavelength light transmittance resistance.

Description of the drawings:

the pigment is commonly used: red, orange, yellow, green, blue, violet, white, black and other organic or inorganic pigment powders;

red, orange, yellow, green, blue, violet, etc. absorb light in a certain wavelength range of visible light, but do not absorb light in other wavelength ranges and only reflect light.

White reflects only each wavelength range and has no absorption;

black absorbs each wavelength range, but the color brightness of the coating film is obviously reduced due to the addition of black, and the coating film with high brightness cannot be added in a large amount;

the ultraviolet absorbent has absorption in the 290-380nm wave range, but has no absorption in other wavelength ranges, as shown in FIG. 1, and FIG. 1 shows the light transmittance of the ultraviolet absorbent at a concentration of 10-80mg/L in the coating film. Wherein, when the concentration of the ultraviolet absorbent is 10mg/L, the activity at 40 μm is 0.001-0.25%; when the concentration of the ultraviolet absorbent is 20mg/L, the activity at 40 mu m is 0.002-0.5%; when the concentration of the ultraviolet absorber is 40mg/L, the activity at 40 μm is 0.004-1.00%; when the concentration of the ultraviolet absorber is 60mg/L, the activity at 40 μm is 0.006-1.5%; when the concentration of the ultraviolet absorber was 80mg/L, the activity at 40 μm was 0.008 to 2.0%.

Example 1

A composition of the general type having good hiding properties was prepared as shown in Table 3 below.

Table 3 raw material composition of example 1

Serial number	Name of Material	In proportion wt%
			1	Aluminium powder MH-8801	8
2	Solvent isopropanol	44.9
			3	Acrylic resin ACS-1212	6.4
4	Dispersing aid BYK-DISPERBYK-192	40
			5	Ultraviolet light absorber TINUVIN477	0.7

In Table 3, the aluminum powder is non-floating type silver element aluminum powder, the particle diameter D90 is 12-20 μm, and the ratio of thickness to diameter is 65: 1.

The preparation of a composition with good hiding properties of the above general type comprises the following steps:

firstly adding aluminum powder into a container, then adding a solvent and soaking for 2 hours;

stirring at a high speed for dispersion, slowly adding acrylic resin in a fine flow state under the stirring state, wrapping the aluminum powder, and uniformly dispersing;

adding a dispersing auxiliary agent while stirring, and uniformly dispersing;

adding an ultraviolet absorbent under stirring, and dispersing uniformly to obtain the composition;

and (5) confirming the fineness and the particle size of the product, and packaging for later use according with requirements.

A waterborne basecoat has the formulation shown in Table 4 below.

Table 4 raw material composition of aqueous midway paint of example 1, comparative example 1 and comparative example 2

The preparation method of the waterborne primer surfacer comprises the following steps:

according to the formula shown in the table 4, firstly adding 5, sequentially adding 6, 7, 8, 9 and 10 under high-speed stirring, and uniformly dispersing;

adding 1, 2, 3 and 4 under stirring, dispersing uniformly, and determining whether the fineness is qualified; after the product is qualified, the product is obtained,

adding 15 under stirring, dispersing uniformly, and determining whether the fineness and the particle size are qualified; after the product is qualified, the product is obtained,

adding 11, 12, 13 and 14, dispersing uniformly, confirming the properties of product fineness, thixotropy and the like, and determining whether the physical and chemical properties of a coating film meet the design requirements or not, wherein the properties are met;

and obtaining the water-based primer surfacer.

Sampling and spraying, and confirming the covering power, the appearance of the coating film, the color, the stone chip resistance and the light ray transmittance resistance.

Comparative example 1

An aqueous basecoat material having the formulation shown in Table 4 above was prepared in the same manner as in example 1, except that an aqueous basecoat material was prepared without adding the composition. Sampling and spraying, and confirming the covering power, the appearance of the coating film, the color, the stone chip resistance and the light ray transmittance resistance.

Comparative example 2

The primer coatings obtained in the above example 1, comparative example 1 and comparative example 2 were consistent in construction viscosity and film thickness to compare the appearance and properties. The film thickness and process are shown in table 5 below.

TABLE 5 film thickness and Process for each of the coatings of example 1 and comparative examples 1 and 2

The comparison results are shown in table 6 below.

TABLE 6 results of performance test of the aqueous midway paint of example 1 and comparative examples 1 and 2

Item	Example 1	Comparative example 1	Comparative example 2	Experimental methods
					Hiding property	○	×	○	GB 1726
Colour(s)	○	○	○	MES MN601 6
					Appearance of the product	○	○	×	MES MN601 4
Resistance to stone impact	○	○	×	MES MN601 30
					Resistance to light transmission	○	×	○	MES MN601 40

Note ○ for pass and X for NG.

And (4) conclusion: in the water-based primer coating, the composition of the invention can simultaneously meet the requirements of covering property and light ray transmission resistance, and ensure that the appearance and the stone chip resistance of the coating film are qualified.

Example 2

A composition of the general type having good hiding properties was prepared as shown in Table 7 below.

Table 7 raw material composition of example 2

In Table 7, the aluminum powder is a non-leafing silver-element aluminum powder, the particle diameter D90 is 12-20 μm, and the ratio of thickness to diameter is 75: 1.

adding a dispersing auxiliary agent while stirring, and uniformly dispersing;

A solvent borne basecoat material having the formulation shown in table 8 below.

TABLE 8 raw material composition of solvent-type intermediate coat for example 2, comparative example 3 and comparative example 4

The preparation method of the solvent-based primer surfacer comprises the following steps:

according to the formula in the table 8, 1, 2, 3, 4, 5, 6, 7 and 8 are added in sequence under high-speed stirring, and are uniformly dispersed;

adding 10 under stirring, dispersing uniformly, and determining whether the fineness and the particle size are qualified; after the product is qualified, the product is obtained,

adding 9, dispersing uniformly, adjusting the viscosity of the product, confirming the properties of fineness, thixotropy and the like of the material, and determining whether the physical and chemical properties of the coating film meet the design requirements or not, wherein the properties meet the requirements;

and obtaining the solvent-based primer surfacer. Sampling and spraying, and confirming the covering power, the appearance of the coating film, the color, the stone chip resistance and the light ray transmittance resistance.

Comparative example 3

A solvent-borne basecoat material having the formulation shown in Table 7 above was prepared in the same manner as in example 2, except that a waterborne basecoat material was prepared without adding the composition. Sampling and spraying, and confirming the covering power, the appearance of the coating film, the color, the stone chip resistance and the light ray transmittance resistance.

Comparative example 4

A solvent-borne basecoat material having the formulation shown in Table 7 above was prepared in the same manner as in example 2, except that a waterborne basecoat material was prepared without adding the composition. Sampling and spraying, and confirming the covering power, the appearance of the coating film, the color, the stone chip resistance and the light ray transmittance resistance. The film thicknesses and processes are shown in table 9 below.

Table 9 example 2 and comparative examples 3 and 4 each film thickness and process is as follows:

the primer coatings obtained in the above example 2, comparative example 3 and comparative example 4 were consistent in construction viscosity and film thickness to compare the appearance and properties. The comparison results are shown in table 10 below.

TABLE 10 Performance test results of solvent-type intermediate paint of example 2 and comparative examples 3 and 4

Note ○ for pass and X for NG.

And (4) conclusion: the functional material prepared by the invention is applied to a solvent type high polymer material, the covering property and the light ray transmission resistance can meet the requirements at the same time, and the coating appearance and the stone chip resistance are ensured to be qualified.

Example 3

A composition of the general type having good hiding properties was prepared as shown in Table 11 below.

Table 11 raw material composition of example 3

Serial number	Name of Material	In proportion wt%
			1	Aluminum powder FD-5090	10
2	Solvent ethylene glycol isooctyl ether	42.3
			3	Acrylic resin ACS-1016	7.2
4	Dispersing assistant SURFYNOL S440	40
			5	Ultraviolet absorbent TINUVIN 384-2	0.5

In Table 11, the aluminum powder is a non-leafing silver-element aluminum powder, the particle diameter D90 is 15-20 μm, and the ratio of thickness to diameter is 80: 1.

The preparation method of the composition is the same as that of example 1, the composition is used in the water-based intermediate coat paint according to the method of example 1, the addition amount is 5 wt%, corresponding performance tests are carried out, and the obtained intermediate coat paint is qualified in covering property, color, appearance, stone chip resistance and light ray transmittance resistance.

Example 4

A composition of the general type having good hiding properties was prepared as shown in table 12 below.

Table 12 raw material composition of example 3 composition

Serial number	Name of Material	In proportion wt%
			1	Aluminum powder 6315NS	6
2	Solvent butyl acetate	44
			3	Acrylic resin DIANAL HR-2077	4.8
4	Dispersing aid BYK-DISPERBYK-182	45
			5	Ultraviolet absorbent TINUVIN 384-2	0.2

In Table 12, the aluminum powder is a non-leafing silver-element aluminum powder, the particle diameter D90 is 15-20 μm, and the ratio of thickness to diameter is 60: 1.

The preparation method of the composition is the same as that in example 2, the composition is used in a solvent-based intermediate coat paint according to the method in example 2, the addition amount is 5 wt%, corresponding performance tests are carried out, and the obtained intermediate coat paint is qualified in covering performance, color, appearance, stone chip resistance and light ray transmittance resistance.

Comparative example 5

Example 1 was repeated, except that the powdery aluminum had a particle size of 1 to 8 μm and a thickness to diameter ratio of 85:1, and the remaining conditions were not changed, and that a composition was prepared by the method of example 1.

The composition is used in water-based primer surfacer and solvent-based primer surfacer according to the methods of example 1 and example 2 respectively, and corresponding performance tests are carried out, and the obtained primer surfacer has unqualified performance in light ray transmission resistance and covering property.

Comparative example 6

Example 1 was repeated with the difference that the composition had the following raw material composition in weight percent: 15% of aluminum powder, 5% of solvent, 5% of acrylic resin, 40% of dispersing aid and 40% of solvent. The rest conditions are unchanged, and the composition is prepared.

The composition is used in water-based primer surfacer and solvent-based primer surfacer according to the methods of example 1 and example 2 respectively, and corresponding performance tests are carried out, and the obtained primer surfacer is unqualified in performance appearance and stone chip resistance.

Specific middle coat properties of the above examples 3 and 4 and comparative examples 5 and 6 are shown in table 13 below.

TABLE 13 results of performance test of the midway paints of examples 3 to 4 and comparative examples 5 to 6

Item	Example 3	Example 4	Comparative example 5	Comparative example 6	Experimental methods
						Hiding property	○	○	×	○	GB 1726
Colour(s)	○	○	○	○	MES MN601 6
						Appearance of the product	○	○	○	×	MES MN601 4
Resistance to stone impact	○	○	○	×	MES MN601 30
						Resistance to light transmission	○	○	×	○	MES MN601 40

Note ○ for pass and X for NG.

Example 5

Example 1 was repeated with the difference that the composition had the following raw material composition in weight percent: aluminum powder MH-88017.0 wt%, solvent isopropanol 42.0 wt%, acrylic resin ACS-12126.0 wt%, dispersing aid BYK-DISPERBYK-19245.0 wt%, and the rest conditions are unchanged, so that the universal composition with good covering property is prepared.

The composition was applied to a waterborne basecoat and tested for properties as in example 1, and the results indicated that the hiding, color, appearance, stone chip resistance, and light transmission resistance were acceptable, as shown in Table 14 below.

Comparative example 7

The composition comprises the following raw materials in percentage by weight: MH-88018.0 wt%, solvent isopropanol 45.0 wt%, acrylic resin ACS-12123.0 wt%, dispersing assistant BYK-DISPERBYK-19243.3 wt%, ultraviolet absorbent TINUVIN 4770.7wt%, and keeping the conditions unchanged to prepare the composition.

The composition was applied to a waterborne basecoat and tested for properties as in example 1 and the appearance was found to be off-specification as shown in Table 14 below.

TABLE 14 results of performance test of the aqueous midway paints of example 5 and comparative example 7

Note ○ for pass and X for NG.

It should be understood that the above-mentioned embodiments of the present invention are only examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention, and it will be obvious to those skilled in the art that other variations or modifications may be made on the basis of the above description, and all embodiments may not be exhaustive, and all obvious variations or modifications may be included within the scope of the present invention.

Claims

1. The general composition with good covering performance is characterized by comprising the following raw materials in percentage by weight:

2. the composition of claim 1, wherein the aluminum powder is a non-leafing silver-element type aluminum powder; the particle size D90 of the aluminum powder is 10-20 μm; the thickness-diameter ratio of the aluminum powder is 60:1-80: 1.

3. The composition as claimed in claim 1, wherein the acrylic resin is selected from the group consisting of phosphoric acid group-containing acrylic resins;

preferably, the dispersing aid is selected from a pigment affinity group containing dispersant;

preferably, the solvent is selected from one or more of alcohol ether solvents and ester solvents.

4. The composition according to claim 1, wherein the mass ratio of the aluminum powder to the acrylic resin in the raw materials is (0.5-2.5): 1.

5. the composition of claim 1, wherein the raw material further comprises 0-2% by weight of an ultraviolet absorber; preferably, the raw materials contain 0% or 0.01-2% of ultraviolet absorbent by weight percentage.

6. The composition of claim 1, wherein the aluminum powder is encapsulated in the acrylic resin.

7. A process for the preparation of a composition according to any one of claims 1 to 6, comprising the steps of:

soaking the aluminum powder by using a solvent to disperse the aluminum powder;

adding acrylic resin to wrap the aluminum powder by the acrylic resin;

adding a dispersing aid.

8. Use of a composition according to any one of claims 1 to 6 in water-borne or solvent-borne coatings.

9. Use according to claim 8, wherein the water-based or solvent-based coating is a water-based or solvent-based primer surfacer.

10. Use according to claim 9, characterized in that the composition is added in an amount of 1-20% by weight in water-borne or solvent-borne coatings.