CN105153845A - Coating product and preparation method thereof - Google Patents

Abstract

The invention discloses a coating product which comprises a base material and a plurality of layers of coatings, wherein the plurality of layers of coatings cover all or part surface of the base material, and comprises the materials of acrylic resin and metallic oxide spherical particles; the metallic oxide spherical particles are made of copper oxide, zinc oxide, titanium dioxide, aluminum oxide, ferric oxide or zirconium oxide with the particle diameter of 0.2-5.0 [mu]m and the thickness of 10-100 [mu]m; the plurality of layers of coatings consist of the first coating, the second coating, ... and the Nth coating from the bottom surface to the top surface. The invention further discloses a preparation method for the coating product. The uniform coating in the prior art is replaced by the plurality of layers of coatings, so that under the condition of not adding material consumption, the spectral reflectivity of the near-infrared light area is improved, the heating effect of the coating product is reduced, and the performance of the coating product is improved.

Description

A kind of coated article and preparation method thereof

Technical field

The invention belongs to coated material field, more specifically, relate to a kind of coated article and preparation method thereof.

Background technology

Coated material is widely used in building, automobile and other cultures, and tellurian object all will receive a large amount of solar radiations every day.Arrive the solar radiation wavelength of earth surface and concentrate on 0.3 μm to 2.5 μm within the scope of this, specifically be divided into ultra-violet region (0.3 μm ~ 0.38 μm), visible region (0.38 μm ~ 0.78 μm) and near-infrared region (0.78 μm ~ 2.5 μm).Because a large amount of minimizing of city's green areas and building, road to a large amount of absorptions of quantity of radiant energy, thus create tropical island effect, make intown medial temperature higher than the temperature of surrounding environment three to five degrees Celsius.Such radiation absorption add interior of building temperature thus add room air regulate energy consumption.

In order to improve this situation, some measures effectively reducing radiation absorption are carried out, more significantly exactly pulverous metal oxide particle (as titanium dioxide, aluminum oxide, zinc oxide etc.) is permeated in some parents such as resin, such coated material can increase the reflectivity of near-infrared region thus the heat effect of reduction radiation as much as possible, reduces the reflectivity of visible region simultaneously thus presents the outward appearance softer to human eye.

Japanese scholars is from theory and test two aspects to the research of copper oxide coating, copper oxide particle is even obtains disperse in resin matrix, the coating obtained so not only has good aesthetic compared with material in the past, and heat effect is also more satisfactory, the parameters optimization R of the coating obtained _optmaximum value be 15.56.(H.Gonome, M.Baneshi, J.Okajima, A.Komiya, S.Maruyama, Controllingtheradiativepropertiesofcoolblack-colorcoatin gspigmentedwithCuOsubmicronparticles, J.Quant.Spectrosc.Radiant.Transfer132 (2014) 90-98.), but this coating performance still has the space of improving further.

Summary of the invention

For above defect or the Improvement requirement of prior art, the invention provides a kind of coated article and preparation method thereof, its object is to the reflectivity being increased near-infrared region by the laminated coating on its surface, reduce the heat effect of coated article thus.

For achieving the above object, according to one aspect of the present invention, provide a kind of coated article, comprise base material and coating, described coating is covered in all or part of surface of described base material, and the material of described coating comprises acrylic resin and metal oxide particle, and described coating is laminated coating, form from bottom to top layer by the first coating, the second coating to N coating, and wherein the volume fraction of metal oxide particle is respectively a ₁, a ₂to a _n, and 5%>=a _i>=0.5%, N be more than or equal to 2 arbitrary integer, i is 2 to the arbitrary integers of N; Described metal oxide particle is cupric oxide, zinc oxide, titanium dioxide, aluminum oxide, ferric oxide or zirconium white, and the shape of described metal oxide particle is spherical or elliposoidal, and particle diameter is 0.2 μm ~ 5.0 μm; In described coating, the volume fraction of metal oxide particle increases progressively from bottom successively to top layer, improves the spectral reflectivity of coated article in near-infrared region, reduces the heat effect of coated article, improve the parameters optimization of coating.

Preferably, the reflectivity of described substrate surface is 0 ~ 1.0.

Preferably, the total thickness of described laminated coating is 10 μm ~ 100 μm.

Preferably, the first coating, the second coating are identical to the thickness of N coating.

Preferably, the spherical particle of described metal oxide is cupric oxide.

Preferably, 5%>=a _i> a _i-1>=1%.

Preferably, N=2, a ₂: a ₁for 4:1 ~ 9:1.

According to another aspect of the present invention, provide a kind of coating for above-mentioned coated article, the material of described coating comprises acrylic resin and metal oxide particle, described metal oxide particle is cupric oxide, zinc oxide, titanium dioxide, aluminum oxide, ferric oxide or zirconium white, the shape of described metal oxide particle is spherical or elliposoidal, particle diameter is 0.2 μm ~ 5.0 μm, described coating is made up of to N coating the first coating, the second coating, and wherein the volume fraction of metal oxide particle is respectively a ₁, a ₂to a _n, and 5%>=a _i> a _i-1>=0.5%, N be more than or equal to 2 arbitrary integer, i is 2 to the arbitrary integers of N.

According to another aspect of the present invention, additionally provide a kind of preparation method of above-mentioned coated article, laminated coating is covered in all or part of surface of base material, the material of described laminated coating comprises acrylic resin and metal oxide particle, described metal oxide particle is cupric oxide, zinc oxide, titanium dioxide, aluminum oxide, ferric oxide or zirconium white, the shape of described metal oxide particle is spherical or elliposoidal, particle diameter is 0.2 μm ~ 5.0 μm, described laminated coating from bottom to top layer by a coating, second coating forms to N coating, wherein the volume fraction of metal oxide particle is respectively a ₁, a ₂to a _n, and 5%>=a _i> a _i-1>=0.5%, N be more than or equal to 2 arbitrary integer, i is 2 to the arbitrary integers of N.

The above technical scheme conceived by the present invention compared with prior art, has following beneficial effect:

1, by the laminated coating that metal oxide particle volume fraction is different, replace uniform coating of the prior art, improve the spectral reflectivity of coated article in near-infrared region, reduce the heat effect of coated article;

2, this coated article is at the spectral reflectivity of visible region and the coated article of uniform coating without significant difference, can not increase the stimulation to human eye while improving heat effect;

3, when the mean volume fraction of metal oxide particle is equal, by the parameters optimization R of coating _optimprove 30% nearly, thus when not increasing materials consumption, improving the performance of coated article, reducing production cost.

Accompanying drawing explanation

Fig. 1 is the graphic representation of complex refractivity index with wavelength change of copper oxide particle;

Fig. 2 is coated article schematic diagram of the present invention;

Fig. 3 is the comparison diagram of the spectral reflectivity of embodiment of the present invention 2-3 and comparative example 1-3;

Fig. 4 is the comparison diagram of the spectral reflectivity of embodiment of the present invention 5-6, comparative example 3 and comparative example 6;

The comparison diagram of the spectral reflectivity of Fig. 5 embodiment of the present invention 4 and comparative example 3-5.

Embodiment

In order to make object of the present invention, technical scheme and advantage clearly understand, below in conjunction with drawings and Examples, the present invention is further elaborated.Should be appreciated that specific embodiment described herein only in order to explain the present invention, be not intended to limit the present invention.In addition, if below in described each embodiment of the present invention involved technical characteristic do not form conflict each other and just can mutually combine.

When solar irradiation is mapped in the coating covering substrate surface, the physical processes such as reflection and scattering can be there is.The performance difference of coating can make above-mentioned physical process produce different results, and the performance of this coating is by parameters optimization R _optevaluate:

$R_{opt}=\frac{\underset{0.30}{\overset{2.50}{\∫}}I\left(\mathrm{\λ}\right)d\mathrm{\λ}/\underset{0.30}{\overset{2.50}{\∫}}\mathrm{\ρ}\left(\mathrm{\λ}\right)I\left(\mathrm{\λ}\right)d\mathrm{\λ}}{\underset{0.38}{\overset{0.78}{\∫}}\mathrm{\ρ}\left(\mathrm{\λ}\right)\mathrm{\η}\left(\mathrm{\λ}\right)I\left(\mathrm{\λ}\right)d\mathrm{\λ}/\underset{0.38}{\overset{0.78}{\∫}}I\left(\mathrm{\λ}\right)d\mathrm{\λ}}---\left(1\right)$

Wherein I (λ) is the yield of radiation of sun incidence, and ρ (λ) is the spectral reflectivity of coating, and h (λ) is standard luminescent efficiency, parameters optimization R _optlarger, then prove that coating performance is better.

When single spherical or ellipsoidal particle even dispersion are in non-absorbent parent (as acrylic resin), its scattering and absorption characteristic can obtain by separating Maxwell equation equation, this is mainly based on incident wavelength λ, the diameter d of metal oxide particle and the complex refractivity index m=n-i κ of metal oxide particle.The complex refractivity index of copper oxide particle with wavelength change graphic representation as shown in Figure 1.

As shown in Figure 2, wherein specific refractory power and reduction coefficient all show certain regularity in the complex refractivity index change of copper oxide particle within the scope of wavelength 0.3 μm ~ 2.5 μm.Theoretical by Mie, the complex refractivity index of copper oxide particle can be utilized, calculate the radiation characteristic of copper oxide particle, as scattering efficiency and assimilated efficiency.When the specific refractory power of base material is determined, also can obtain anisotropic scattering phase function and also can be obtained by Mie theory.

Wherein, scattering efficiency and assimilated efficiency can be obtained by following equation:

${\mathrm{\σ}}_{\mathrm{\λ}}=N_T\frac{{\mathrm{\πd}}^2}{4}{Q}_{sca,\mathrm{\λ}}\mathrm{......}\left(2\right)$

${\mathrm{\κ}}_{\mathrm{\λ}}=N_T\frac{{\mathrm{\πd}}^2}{4}{Q}_{abs,\mathrm{\λ}}\mathrm{......}\left(3\right)$

$f_{v,cal}=N_T\left(\frac{{\mathrm{\πd}}^3}{6}\right)\mathrm{......}\left(4\right)$

Here Q _{sca, λ}and Q _{abs, λ}be scattering and uptake factor respectively, d is particle diameter, f _{v, cal}grain volume fraction, N _tit is granule density.

Solar radiation incides the schematic diagram of N layer coating as shown in Figure 2, and wherein, metal oxide particle is monodispersed.Sunlight incides the parallel of coatingsurface and diffuses in penetrates the enough Bird model descriptions of radiating capacity (R.E.Bird, C.Riordan, Simplesolarspectralmodelfordirectanddiffuseirradianceonh orizontalandtiltedplanesattheearth'ssurfaceforcloudlessa tmospheres, JApplMeteorolClim25 (1986) 87-97.), at incident beam and coating N, because the different of specific refractory power specular reflection can occur between substrate from coating 1, reflectivity is solved by Fresnel theorem, between its floating coat, the scattering efficiency of metal oxide particle and assimilated efficiency can be led to Mie theory and solved.

In order to analyze the radiation delivery process in coating, coating is used as the one dimension parallel flat system process containing participating medium.Equation of radiative transfer describes at position z, direction and the yield of radiation of af at wavelength lambda:

$\frac{n}{c_0}\frac{\∂I(z,\hat{s},\mathrm{\λ})}{\∂\mathrm{\λ}}+n^2\frac{\∂}{\∂s}\[\frac{I(z,\hat{s},\mathrm{\λ})}{n^2}\]=-{\mathrm{\β}}_{\mathrm{\λ}}I(z,\hat{s},\mathrm{\λ})+\frac{{\mathrm{\σ}}_{\mathrm{\λ}}}{4\mathrm{\π}}\underset{4\mathrm{\π}}{\∫}I(z,\hat{s},\mathrm{\λ}){\mathrm{\Φ}}_{\mathrm{\λ}}({\hat{s}}_i,\hat{s}){\mathrm{d\Ω}}_i\mathrm{......}\left(5\right)$

Here I is yield of radiation, and n is the specific refractory power of parent, c ₀beam velocity of propagation in a vacuum, β _λ=κ _λ+ σ _λreduction coefficient, Φ _λit is Scattering Phase Function.Equation (5) integration is obtained:

$\frac{I(z,\hat{s},\mathrm{\λ})}{n^2}=\frac{1}{n_{z_w}^2}I(z_w,{\hat{s}}_w,\mathrm{\λ})\exp (-\underset{0}{\overset{s}{\∫}}{\mathrm{\β}}_{\mathrm{\λ}}{\mathrm{ds}}^{\′})+\underset{0}{\overset{s}{\∫}}S(z^{\′},{\hat{s}}^{\′},\mathrm{\λ})\exp (-\underset{s^{\′}}{\overset{s}{\∫}}{\mathrm{\β}}_{\mathrm{\λ}}{\mathrm{ds}}^{\′\′}){\mathrm{\β}}_{\mathrm{\λ}}{\mathrm{ds}}^{\′}\mathrm{......}\left(6\right)$

What the Section 1 on the right side of this equation showed is the contribution of base material to yield of radiation, the contribution of scatters of what Section 2 represented is scattering medium, and S is source item.Above-mentioned parameter is substituted into formula (6), obtains at an arbitrary position, the yield of radiation under any wavelength:

$\begin{array}{c}\frac{I(z,\hat{s},\mathrm{\λ})}{n^2}=\[\frac{1}{{n^2}_0}I(z_w^{\′},{\hat{s}}_w,\mathrm{\λ})+\frac{1}{\mathrm{\π}}\underset{w}{\∫}\frac{1}{{n^2}_{z_w}}\mathrm{\π}I(z_w^{\′},{\hat{s}}_w,\mathrm{\λ})R_d^s(z_w^{\′},z_w,\hat{s},\mathrm{\λ})dA\]\exp (-\underset{0}{\overset{s}{\∫}}{\mathrm{\β}}_{\mathrm{\λ}}{\mathrm{ds}}^{\′})\\ +\underset{0}{\overset{s}{\∫}}\frac{1}{4{\mathrm{\π\β}}_{\mathrm{\λ}}}\[\underset{w}{\∫}\frac{1}{n^2}\×\mathrm{\π}I(z_w^{\′},{\hat{s}}_w,\mathrm{\λ})R_d^s(z_w,z^{\′},{\hat{s}}^{\′},\mathrm{\λ})dA\]\exp (-\underset{0}{\overset{s}{\∫}}{\mathrm{\βds}}^{\′\′}){\mathrm{\βds}}^{\′}\end{array}\mathrm{......}\left(7\right)$

Here what represent is base material the energy launched is by base material z _wbe reflected under wavelength X energy fraction on direction, represent similar implication.

As can be seen from Figure 2, solar radiation is incided in coating from top, coating is divided into N decile in the z-direction, i.e. N number of unit, wherein each unit place yield of radiation is divided into again 180 deciles, after discrete, the volume fraction of metal oxide particle is a (z) (such as, a at an arbitrary position ₂(z)=3% (0≤z<0.5L), a ₁(z)=1% (0.5L≤z≤L)).

By discrete equation (7), can obtain at unit i ₁, direction and the yield of radiation of af at wavelength lambda

$\begin{array}{c}\frac{I(i_1,{\mathrm{\&theta;}}_{i_1},\mathrm{\&lambda;})}{n^2}=\&lsqb;\frac{1}{n_0^2}I(0,{\mathrm{\&theta;}}_0,\mathrm{\&lambda;})+\frac{1}{\mathrm{\&pi;}}\left(\frac{1}{{n_{N+1}}^2}\mathrm{\&pi;}I\right(0,{\mathrm{\&theta;}}_0^{\&prime;},\mathrm{\&lambda;})\&times;R_d^s(0,N+1,{\mathrm{\&theta;}}^{\&prime;},\mathrm{\&lambda;}\left)\right)\&rsqb;\exp (-{\mathrm{\&tau;}}_{0\&RightArrow;i_1})\\ \frac{1}{4{\mathrm{\&pi;\&beta;}}_{\mathrm{\&lambda;}}}\underset{i_2}{\overset{alongthepath}{\mathrm{\&Sigma;}}}\&lsqb;\frac{1}{n^2}\mathrm{\&pi;}I\left(0,{\mathrm{\&theta;}}_0^{\&prime;\&prime;},\mathrm{\&lambda;}\right)\&times;R_d^s\left(0,i_2,{\mathrm{\&theta;}}_{i_2},\mathrm{\&lambda;}\right)\&rsqb;|\exp (-{\mathrm{\&tau;}}_{i_2\&RightArrow;i_1})-\exp (-{\mathrm{\&tau;}}_{i_2\&RightArrow;i_1})|\end{array}\mathrm{......}\left(8\right)$

When particle diameter is identical and particle overall volume mark is identical, metal oxide particle can have multiple distribution mode, comprise and being uniformly distributed, Gradient distribution and Multi-layers distributing etc., and Gradient distribution can be calculated by formula (8), and in the coating of Multi-layers distributing, yield of radiation when wavelength is λ, thus calculate its parameters optimization R further _opt.

According to above theoretical basis, the invention provides a kind of coated article, comprise base material and coating, described coating is covered in all or part of surface of described base material, the material of described coating comprises acrylic resin and metal oxide particle, described coating is laminated coating, form, and wherein the volume fraction of metal oxide particle is respectively a from bottom to top layer by the first coating, the second coating to N coating ₁, a ₂to a _n, N be more than or equal to 2 arbitrary integer, i is 2 to the arbitrary integers of N; Described metal oxide particle is cupric oxide, zinc oxide, titanium dioxide, aluminum oxide, ferric oxide or zirconium white, and the shape of described metal oxide particle is spherical or elliposoidal, and particle diameter is 0.2 μm ~ 5.0 μm; In described coating, the volume fraction of metal oxide particle increases progressively from bottom successively to top layer, thus improves the parameters optimization of coating, improves the spectral reflectivity of coated article in near-infrared region, reduces the heat effect of coated article.Here the volume fraction a of metal oxide particle is selected _ibetween 0.5% ~ 5%, when grain volume fraction is too small, the effect of coated material is very little, is in close proximity to the characteristic of pure acrylic resin, and the reflectivity of its visible region is excessive, affects experience; And when grain volume fraction is excessive, particle there will be bonding phenomenon, affect the overall performance of coating.

Coat-thickness should control within 100 μm, and this also contemplates practicality and aesthetic property except considering actual tooling cost.When metal oxide particle diameter is greater than 5 μm, needs calculating theory of geometric optics being introduced this coating parameters optimization, be not suitable for the present invention.

Described metal oxide particle is preferably cupric oxide.Described first coating, the second coating are preferably the coating of same thickness to N coating.

As N=2, a ₂: a ₁be preferably 4:1 ~ 9:1.

Present invention also offers a kind of coating for above-mentioned coated article, it is characterized in that, the material of described coating comprises acrylic resin and the spherical particle of metal oxide, and described coating is made up of to N coating the first coating, the second coating, and wherein the volume fraction of metal oxide particle is respectively a ₁, a ₂to a _n, and 5%>=a _i> a _i-1>=0.5%, N be more than or equal to 2 arbitrary integer, i is 2 to the arbitrary integers of N.

The preparation method of this coating is the quality that calculates copper oxide particle needed for coating and acrylic resin, then by disperse phase copper oxide particle and mixed with resin even, under the temperature condition of 70 DEG C ~ 90 DEG C, add the colloidal sol of thermosetting homogeneous transparent.

This coating is sprayed at successively thickness base material being formed setting, after drying, namely obtains coated article of the present invention.

Embodiment 1

Base material select reflectivity be 1.0 wall, metal oxide particle selects diameter to be the copper oxide particle of 0.57 μm, scattering medium selects acrylic resin, described coating is the first coating and the second coating, first coating and the second coating are all made up of copper oxide particle and acrylic resin, wherein the volume fraction of cupric oxide is respectively 0.5% and 4.5%, and thickness is all 20 μm.First coating is covered in substrate surface, and the second coating is covered in the first coatingsurface.

Adopt the I (λ) in document and h (λ) parameter, and obtain spectral reflectivity ρ (λ) by Mie Theoretical Calculation, substitution equation (1) can be optimized parameter R _opt.The R of the coated material obtained _optmaximum value be 19.80, under equal conditions, compared with the uniform coating of cupric oxide volume fraction in prior art, improve 30% nearly.

Embodiment 2

Repeat embodiment 1, difference is that the reflectivity of described substrate surface is 0, metal oxide particle selects diameter to be the copper oxide particle of 0.50 μm, described coating is from bottom to the coating that the volume fraction of top copper oxide particle evenly increases, the volume fraction of the copper oxide particle of coating bottommost is 1%, the volume fraction of the copper oxide particle of coating top is 4%, and the total thickness of coating is 50 μm.

Embodiment 3

Repeat embodiment 2, difference is that described coating is made up of the first coating and the second coating from bottom to top layer, in first coating, the volume fraction of copper oxide particle is the volume fraction of copper oxide particle in the 1%, second coating is 4%, and the thickness of described first coating and the second coating is all 25 μm.

Embodiment 4

Repeat embodiment 3, difference is that the volume fraction of copper oxide particle in the first coating be the volume fraction of copper oxide particle in the 2.5%, second coating is 5%.

Embodiment 5

Repeat embodiment 3, difference is that the volume fraction of copper oxide particle in the first coating be the volume fraction of copper oxide particle in the 0.5%, second coating is 2.5%.

Embodiment 6

Repeat embodiment 3, difference be described coating be the first coating to the 3rd coating, wherein the volume fraction of copper oxide particle is respectively 0.5%, 2.5% and 5%, and the first coating is all 17 μm to the thickness of the 3rd coating.

Comparative example 1

Repeat embodiment 2, difference is that described coating is from bottom to the coating that the volume fraction of top copper oxide particle evenly reduces, and the volume fraction of the copper oxide particle of coating bottommost is 4%, and the volume fraction of the copper oxide particle of coating top is 1%.

Comparative example 2

Repeat embodiment 3, difference is that the volume fraction of copper oxide particle in the first coating be the volume fraction of copper oxide particle in the 4%, second coating is 1%.

Comparative example 3

Repeat embodiment 3, difference is, described coating be from bottom to the volume fraction of top layer copper oxide particle be the uniform coating of 2.5%.

Comparative example 4

Repeat embodiment 3, difference is that the volume fraction of copper oxide particle in the first coating be the volume fraction of copper oxide particle in the 5%, second coating is 2.5%.

Comparative example 5

Repeat embodiment 3 with described same steps, difference is that the volume fraction of copper oxide particle in the first coating be the volume fraction of copper oxide particle in the 2.5%, second coating is 0.5%.

Comparative example 6

Repeat embodiment 6 with described same steps, difference is that described first coating is in the 3rd coating, and the volume fraction of copper oxide particle is respectively 5%, 2.5% and 0.5%.

Interpretation

Fig. 2 is the Spectroscopic analysis results of embodiment 2-3 and comparative example 1-3 under the wavelength of 0.3 μm ~ 2.5 μm.Can find out, the visible region of 0.38 μm ~ 0.78 μm, embodiment 2-3 is compared with comparative example 1-3, its spectral reflectivity does not almost change, and the near-infrared region of 0.78 μm ~ 2.5 μm, the reflectivity of embodiment 2-3 obviously raises, confirm total volume fraction one timing when coating, metal oxide upper strata volumetric concentration is larger, there is when lower floor is less good performance, can while the solar radiation in more effectively reflect near infrared light district, be unlikely and reduce visible ray human eye is impacted.

Under this operating mode, coating has better effect, not only reduces the stimulation of luminous reflectance to human eye to a greater degree, also reduces building energy consumption simultaneously.

Fig. 3 is embodiment 5, embodiment 6, comparative example 3 and comparative example 6 Spectroscopic analysis results under the wavelength of 0.3 μm ~ 2.5 μm.Can find out, the visible region of 0.38 μm ~ 0.78 μm, embodiment 5-6 is compared with comparative example 3-6, its spectral reflectivity does not almost change, and the near-infrared region of 0.78 μm ~ 2.5 μm, embodiment 5 is similar to comparative example 3 spectral reflectivity, and embodiment 6 is better than comparative example 3, and comparative example 6 is inferior to comparative example 3.The volume fraction that can be regarded as copper oxide particle in the first coating and the second coating due to comparative example 3 is all the uniform coating of 2.5%, from embodiment 5 compared with comparative example 3, confirm when the volume fraction height of copper oxide particle during upper strata coating is than lower floor coating, even if the volume fraction reducing lower floor's copper oxide particle also can not affect the character of coating, and now can reduce the usage quantity of metal oxide particle, reduce production cost.And by embodiment 6, comparative example 6 compared with comparative example 3, confirming total volume fraction one timing when copper oxide particle in coating, during the volume fraction height of upper strata coating than copper oxide particle in lower floor coating, the spectral reflectivity of coating is better.

Fig. 4 is embodiment 4 and the Spectroscopic analysis results of comparative example 3-5 under the wavelength of 0.3 μm ~ 2.5 μm.Can find out, the visible region of 0.38 μm ~ 0.78 μm, embodiment 4 is similar with the spectral reflectivity of comparative example 3-5, and the near-infrared region of 0.78 μm ~ 2.5 μm, comparative example 4 is similar to comparative example 3 spectral reflectivity, and embodiment 4 is better than comparative example 3, and comparative example 5 is inferior to comparative example 3.From comparative example 4 compared with comparative example 3, confirm when during upper strata coating is than lower floor coating, the volume fraction of copper oxide particle is low, even if the volume fraction raising lower floor's copper oxide particle also can not affect the performance of coating, and now can increase the usage quantity of metal oxide particle.From comparative example 5 compared with comparative example 3, confirm volume fraction one timing when copper oxide particle in lower floor's coating, the volume fraction reducing copper oxide particle in the coating of upper strata can affect the spectral reflectivity of coating.From embodiment 4 compared with comparative example 3, confirm volume fraction one timing when copper oxide particle in lower floor's coating, the volume fraction improving copper oxide particle in the coating of upper strata can promote the spectral reflectivity of coating.

In sum, bilayer and laminated coating, compared with single-layer coating, higher parameters optimization can be obtained under the constant prerequisite of production cost, effectively can not only weaken the glass curtain wall sunlight reflection of buildings in general to the stimulation of human eye, and can the solar radiation in farthest reflect near infrared light district, thus reduce the cooling load of buildings.

Those skilled in the art will readily understand; the foregoing is only preferred embodiment of the present invention; not in order to limit the present invention, all any amendments done within the spirit and principles in the present invention, equivalent replacement and improvement etc., all should be included within protection scope of the present invention.

Claims (8)

1. a coated article, comprise base material and coating, described coating is covered in all or part of surface of described base material, the material of described coating comprises acrylic resin and metal oxide particle, it is characterized in that, described coating is laminated coating, form, and wherein the volume fraction of metal oxide particle is respectively a from bottom to top layer by the first coating, the second coating to N coating ₁, a ₂to a _n, and 5%>=a _i>=0.5%, i is the arbitrary integer of 2 to N; Described metal oxide particle is cupric oxide, zinc oxide, titanium dioxide, aluminum oxide, ferric oxide or zirconium white, and the shape of described metal oxide particle is spherical or elliposoidal, and particle diameter is 0.2 μm ~ 5.0 μm; In described coating, the volume fraction of metal oxide particle increases progressively from bottom successively to top layer, thus improves the spectral reflectivity of coating in near-infrared region.

2. coated article as claimed in claim 1, it is characterized in that, the reflectivity of described substrate surface is 0 ~ 1.0.

3. coated article as claimed in claim 1, it is characterized in that, the total thickness of described laminated coating is 10 μm ~ 100 μm.

4. coated article as claimed in claim 1, it is characterized in that, described first coating, the second coating are identical to the thickness of N coating.

5. coated article as claimed in claim 1, it is characterized in that, described metal oxide particle is cupric oxide.

6. coated article as claimed in claim 1, is characterized in that, 5%>=a _i>=1%.

7. coated article as claimed in claim 1, is characterized in that, N=2, a ₂: a ₁for 4:1 ~ 9:1.

8. the preparation method as coated article as described in any one in claim 1-7, it is characterized in that, laminated coating is covered in all or part of surface of base material, the material of described laminated coating comprises acrylic resin and metal oxide particle, described metal oxide particle is cupric oxide, zinc oxide, titanium dioxide, aluminum oxide, ferric oxide or zirconium white, its particle diameter is 0.2 μm ~ 5.0 μm, described laminated coating forms from bottom to top layer by the first coating, the second coating to N coating, and wherein the volume fraction of metal oxide particle is respectively a ₁, a ₂to a _n, and 5%>=a _i> a _i-1>=0.5%, N be more than or equal to 2 arbitrary integer, i is 2 to the arbitrary integers of N.