Self-cleaning anti-fog element and manufacture method thereof
Technical field
The present invention relates to a kind of self-cleaning anti-fog element, as antifog glass and antifog film etc., also relate to a kind of manufacture method of anticlouding element.
Background technology
In daily life, industrial production activities, when windshield, the glass pane and reflective mirror etc. of building window glass, automobile, when running into malaria condensation, easily form many small water droplets (mist) and astigmatism at minute surface or glass surface, transparency is reduced and affects sight line, make troubles.
The function of surface membrane material mainly TiO of the self-cleaning glass come into operation at present and research and develop
2and TiO
2with the compound of other metals, metal oxide or other element dopings.The self-cleaning function of super hydrophilic self-cleaning glass shows as two aspects: one is the organic ability of photocatalysis Decomposition.TiO
2under ultraviolet light or radiation of visible light, when the energy of illumination photons is greater than or equal to its bandwidth time, the electronics be situated between in band is excited, cross valence band and enter conduction band, conduction band and valence band form electron-hole pair, and electronics, hole have different activity, respectively be adsorbed on TiO
2the organic substance generation redox reaction on surface, generates water and CO
2, thus reach the object of degradation of organic substances.Be after Ultraviolet radiation on the other hand, its surface exhibits of titanium oxide goes out the compatibility to water, and the contact angle of the drop of water on glass material surface is gone to zero, and at its surface spreading, can form uniform moisture film, take away spot by the gravity fall of uniform water film.
And the method preparing titanium dioxide is also a lot.Such as, magnetron sputtering, chemical vapour deposition (CVD), evaporation plating, sol-gal process etc.In order to keep its surface can the hydrophily of long time, silica be also used to combine application with titanium dioxide.
With the TiO that magnetron sputtering method prepares
2the hardness of film is large, but its photocatalysis effect is bad, (the Thin Solid Films such as MakikoYamagishi, Vol 442,227,2003) find, with titanium oxide prepared by magnetron sputtering, when operating air pressure is higher, the catalytic action of light is large.And (the J.Vac.Sci.Technol.A Vol.26 such as Yushiyuki Kubo, 893,2008) find, during hyperbar downstream Slag coating oxidation titanium film, the amount of oxygen of augmenting response gas, can obtain porous titania thin films, this film has very high photocatalytic, but hardness is lower.Titanium oxide hardness prepared by magnetron sputtering is high, but the film of photocatalysis middle air pressure air-flow sputtering under high oxygen.T.Shibata etc. (J.Phys.Chem.B 107,10696,2003) find, if TiO
2film has tensile stress, and its hydrophily is than not having stress or having the film of compression stress well a lot.In fact, because under tensile stress, Ti-O key is elongated, make the increased number of-OH base adsorbed.
When lacking UV-irradiation, TiO
2itself be not hydrophilic.In order to make do not having under UV-irradiation, the surface of film can keep the hydrophilic effect of long period, the SiO of United States Patent (USP) 5854708 proposition porous
2thin layer covers TiO
2film.Like this, ultraviolet is at TiO
2the hole of inducing in film and electronics, can pass through SiO
2the organic matter effect on Kong Yuqi surface, it is decomposed.Due to SiO
2itself is hydrophilic, the hydrophily that can UV-irradiation lower surface do not had to keep the long period yet.But they do not provide TiO
2during as hydrophilic membrane or photocatalzed film, TiO
2microstructure on the impact of film and restriction.
Summary of the invention
The object of this invention is to provide a kind of self-cleaning anti-fog element, there is good lasting hydrophily and anti-fog effect.
For achieving the above object, the technical solution used in the present invention is: a kind of self-cleaning anti-fog element, it comprises
The base material of printing opacity;
The barrier film of printing opacity, is formed in the side of described base material on the surface;
Photocatalysis counterdie, is formed on described barrier film, and described photocatalysis counterdie has loose structure, and the pore volume of described photocatalysis counterdie is 5 ~ 25% to film cumulative volume ratio; Described photocatalysis counterdie is also formed with photocatalysis dura mater, and described photocatalysis dura mater also has loose structure, and the pore volume of photocatalysis dura mater is less than 5% to film cumulative volume ratio.
Furthermore, described base material is glass, and the hardness of described photocatalysis counterdie is less than or equal to 4H, and the hardness of described photocatalysis dura mater is more than or equal to 6H.
Preferably, described photocatalysis counterdie is TiO
2or ZnO or SnO
2film.
Preferably, described photocatalysis dura mater is TiO
2or ZnO or SnO
2film.
When base material is glass, barrier film can stop sodium ion in sputter procedure in glass material or other foreign ions to the diffusion of photocatalysis counterdie, affects TiO
2or ZnO or SnO
2the photocatalytic activity of film.In two-layer photocatalysis film; photocatalysis counterdie forms loose structure; the photocatalysis dura mater deposited afterwards is made also easily to form loose structure; improve light-catalysed effect; in addition due to smaller to film cumulative volume of the pore volume of photocatalysis dura mater; rete quality is comparatively hard, plays the effect of anti abrasive protection internal layer photocatalysis counterdie.Because photocatalysis dura mater has continued the loose structure of bottom, have high surface area, photocatalysis effect is enhanced.Form the gradual transition of pore volume to film cumulative volume ratio between two-layer photocatalysis film, and the density in hole reduces with the increase of photocatalysis membrana layer thickness, thus avoid dust and block internal holes completely.The TiO of such formation
2or ZnO or SnO
2film has tensile stress, because under tensile stress, Ti-O, Zn-O, Sn-O key is elongated, makes the increased number of-OH base adsorbed, is applicable to very much obtaining good hydrophily.Therefore the present invention adopts photocatalysis counterdie and photocatalysis dura mater can obtain good photocatalytic, hydrophily and wearability.
Pore volume is to film cumulative volume than can being determined by the refractive index measuring film, and refractive index can record with ellipsometer test.Then Lorentz-Lorenz equation is utilized,
Here, Vp is the cumulative volume ratio that pore volume accounts for film, and ns is the refractive index of non-porous film, and nf is the refractive index of perforated film.
Say further, described photocatalysis counterdie is TiO
2film, doped with the one in Cu, Nb, Co, N element in described photocatalysis counterdie; Or described photocatalysis counterdie is ZnO film, doped with the one in Al, B, In, Ga element in described photocatalysis counterdie; Or described photocatalysis counterdie is SnO
2film, doped with the one in F, Sb element in described photocatalysis counterdie.
Further, described photocatalysis dura mater is TiO
2film, doped with the one in Cu, Nb, Co, N element in described photocatalysis dura mater; Or described photocatalysis dura mater is ZnO film, doped with the one in Al, B, In, Ga element in described photocatalysis dura mater; Or described photocatalysis dura mater is SnO
2film, doped with the one in F, Sb element in described photocatalysis dura mater.
Preferably, the atomic ratio of described doped chemical to Ti or Zn in described photocatalysis counterdie or described photocatalysis dura mater or Sn is less than 5%.
Preferably, the thickness of described photocatalysis counterdie is 10 ~ 50nm.
Preferably, the thickness of described photocatalysis dura mater is 50 ~ 200nm.
Or described base material can also be plastic sheeting.
Preferably, described base material is PET film or PMMA or PC material.
Preferably, opposite side relative with described barrier film on described base material is provided with tack coat on the surface.
Preferably, the hardness of described photocatalysis counterdie is less than or equal to 2H, and the hardness of described photocatalysis dura mater is more than or equal to 3H.
Preferably, described photocatalysis counterdie and/or photocatalysis dura mater are by middle air pressure air-flow sputtering method deposition.
Preferably, it comprises photocatalysis counterdie described in multilayer and photocatalysis dura mater, the alternately arrangement of photocatalysis counterdie described in multilayer and photocatalysis dura mater, above ground floor photocatalysis dura mater, arrange photocatalysis counterdie and photocatalysis dura mater again, namely described film layer structure can repeated deposition multilayer TiO
2or ZnO or SnO
2/ SiO
2, be superposed to sandwich construction, like this when gross thickness is constant, repeat the interface that the number of plies can reduce steam etch base material and film, improve the weatherability of adhesive strength.
Further, described photocatalysis dura mater is also formed there is loose structure and in hydrophilic transparent hydrophilic film, described hydrophilic film is porous SiO
2film, this SiO
2membrane structure is not fine and close.Preferably, the thickness of described hydrophilic film is 10 ~ 50nm.Due to SiO
2film is deposited on the photocatalysis dura mater of porous, and has porosity characteristic.SiO
2hydroxyl can be adsorbed in surface, forms the Si-OH more stable than Ti-OH, makes the hydrophily retention time longer.SiO
2quality is also harder than photocatalysis counterdie and photocatalysis dura mater, can protect rete below further.
Preferably, described barrier film is SiO
2or Cr
2o
3, or Si
3n
4or Al
2o
3film.
Another object of the present invention is to provide a kind of method manufacturing above-mentioned anticlouding element.
Specifically, for the institute of the present invention technical scheme that achieves the above object is: a kind of manufacture method of self-cleaning anti-fog element, it comprises following step
A, first, with in air pressure air-flow sputtering method, base material deposits one deck barrier film, and reaction electric discharge air pressure is 10 ~ 40Pa, and power density is 5W/cm
2;
B, then, light-plated catalysis counterdie on described barrier film, control Ar/O in reaction
2flow-rate ratio is 100 ~ 400: 1, and coating film thickness is 10 ~ 50nm;
C, on described photocatalysis counterdie, plate one deck photocatalysis dura mater again, control Ar/O in reaction
2flow-rate ratio 600 ~ 1000: 1, coating film thickness is 50 ~ 200nm.
Preferably, in step A, middle air pressure air-flow sputtering method deposition SiO
2film, reaction electric discharge air pressure is 16Pa, and power density is 5W/cm
2;
In step B, control Ar/O
2flow-rate ratio is 450: 1;
In step C, control Ar/O
2flow-rate ratio is 900: 1, the TiO that plating 50 ~ 200nm is thick
2film.
Say further, after step C, then plate the thick hydrophilic film of one deck 10nm-50nm on described photocatalysis dura mater.
Say further, in coating process, keep the temperature of base material to be 0 ~ 300 degree Celsius.Preferably, when described base material is glass, the temperature of base material in coating process, is kept to be more than or equal to 150 degrees Celsius; When described base material is plastic sheeting, keeps the temperature of base material to be more than or equal to 25 degrees Celsius in coating process and be less than or equal to 100 degrees Celsius.
Anticlouding element of the present invention has two-layer photocatalysis film, lower floor TiO
2or ZnO or SnO
2film has more loose loose structure, and film hardness is less, can provide perforated substrate below, upper strata TiO for the photocatalysis dura mater deposited
2or ZnO or SnO
2film is relatively fine and close, and film hardness is comparatively large, plays a protective role, prevent thin film damage to film.Form the gradual transition of pore volume to film cumulative volume ratio between two-layer photocatalysis film, and the density in hole reduces with the increase of photocatalysis membrana layer thickness, the TiO formed like this
2or ZnO or SnO
2film has tensile stress, and because under tensile stress, Ti-O, Zn-O, Sn-O key is elongated, make the increased number of-OH base adsorbed, therefore photocatalysis dura mater in top layer has good hydrophily.
Compared with prior art the present invention has following advantages and effect:
1, have good hydrophily, after Ultraviolet radiation, the contact angle of anticlouding element surface water droplet is almost 0 degree, and without on the glass surface of plated film, water droplet contact angle is greater than 35 degree; Place after 24 and 48 hours in the dark, water droplet contact angle is still almost 0 degree, and therefore the hydrophily retention time is long;
2, photocatalysis counterdie and photocatalysis dura mater have larger specific surface, even if at thinner thickness, also can have strong photo-catalysis capability;
The hardness of the photocatalysis dura mater 3, prepared on glass can reach more than 6H, and on the plastics such as PET, the hardness of photocatalysis dura mater, for can reach more than 3H, has good antiwear characteristic; TiO
2, SnO
2, SiO
2there is good acid-fast alkali-proof characteristic, the weatherability therefore had; And ZnO and SnO
2there is good electric conductivity, can electrostatic be prevented;
4, anticlouding element of the present invention can be made into pad pasting with flexible plastic substrate, be cut into suitable dimension according to embody rule occasion and demand and attach on the such as minute surface such as automobile rearview mirror, glass pane or glass, and not needing to change existing rearview mirror or glass pane etc.
Accompanying drawing explanation
Accompanying drawing 1 is the structural representation of self-cleaning anti-fog element of the present invention;
Accompanying drawing 2 be white glass under UV-irradiation, the decomposition situation of methylene blue solution;
Accompanying drawing 3 be only be coated with one deck photocatalysis membrana glass under UV-irradiation, the decomposition situation of methylene blue solution;
Accompanying drawing 4 is the anticlouding element shown in use Fig. 1, under UV-irradiation, and the decomposition situation of methylene blue solution;
Wherein: 1, base material; 2, barrier film; 3, photocatalysis counterdie; 4, photocatalysis dura mater; 5, hydrophilic film; 6, adhered layer.
Detailed description of the invention
Below in conjunction with drawings and Examples, the invention will be further described:
Fig. 1 shows an embodiment of a kind of self-cleaning anti-fog element of the present invention.In embodiment, anticlouding element comprises
The base material 1 of printing opacity, this base material can be glass or plastic sheeting, when anticlouding element of the present invention is applied to automobile rearview mirror, windshield or glass pane, can directly with back-mirror glass, windshield or glass pane for base material carries out plated film, thus formed anti-fogging rearview mirror, antifog glass etc.; Another embodiment of the present invention anticlouding element is made Pasting to be fixed on film on other objects, in this case this base material can select the plastic sheeting such as PET film or PMMA or PC, and the antifog film material processed can intercept specific dimensions as required and be attached to as rearview mirror, glass pane etc. need antifog body surface;
The barrier film 2 of printing opacity, is formed in the side of described base material 1 on the surface, and this barrier film 2 is SiO
2or Si
3n
4or Cr
2o
3or Al
2o
3film, when base material is glass, barrier film 2 can stop sodium ion in sputter procedure in glass material or other foreign ions to the diffusion of photocatalysis counterdie, affects TiO
2or ZnO or SnO
2the photocatalytic activity of film, the thickness of barrier film is advisable with 15nm-50nm;
Photocatalysis counterdie 3, be formed on described barrier film 2, described photocatalysis counterdie 3 is for having the TiO of loose structure
2or ZnO or SnO
2film, and described TiO
2or ZnO or SnO
2the pore volume of film is 5 ~ 25% to film cumulative volume ratio, the TiO under this pore membrane volume ratio
2or ZnO or SnO
2film has loose loose structure, therefore organic matter is made can be deep in hole, and be decomposed, photocatalysis is best, in general the thickness of photocatalysis counterdie 3 is 10 ~ 50nm, the hardness of described photocatalysis counterdie 3 is less than or equal to 4H, and when base material is plastic sheeting, the hardness of photocatalysis counterdie 3 is less than or equal to 2H, and above-mentioned hardness adopts ASTM D3363 (pencil test method measures the standard test method of hardness of film) to measure.
Described photocatalysis counterdie 3 is also formed with photocatalysis dura mater 4, and described photocatalysis dura mater 4 is for having the TiO of loose structure
2or ZnO or SnO
2film, and TiO
2or ZnO or SnO
2the pore volume of film is less than 5% to film cumulative volume ratio, has hydrophily, and the thickness of described photocatalysis dura mater 4 is 50 ~ 200nm, when base material is glass, the hardness of photocatalysis dura mater 4 is more than or equal to 6H, and when base material is plastic sheeting, the hardness of photocatalysis dura mater 4 is greater than 3H;
The hydrophilic film 5 of transparent porous, be formed on described photocatalysis dura mater 4, hydrophilic film is SiO
2, thickness is 10 ~ 50nm, has loose structure, therefore has hydrophily.
For improving photo-catalysis capability further, anticlouding element is enable to respond wider spectral region, can to photocatalysis counterdie and the doping of photocatalysis dura mater.Described photocatalysis counterdie or photocatalysis dura mater are TiO
2during film, can to its doped with Cu, Nb, Co, N element, the atomic ratio of described doped chemical to titanium is less than 5%.
If photocatalysis counterdie 3 or photocatalysis dura mater 4 are ZnO film, can to its doped with Al, B, In, Ga element, the atomic ratio of described doped chemical to Zn is less than 5%.
If photocatalysis counterdie and photocatalysis dura mater are SnO
2during film, can to the one in its doped F, Sb element, the atomic ratio of described doped chemical to Sn is less than 5%.Make photocatalysis counterdie and photocatalysis dura mater have spectral response range widely by doping means, in existing document, existing wide coverage, no longer repeats herein.
In a preferred embodiment of the invention, this photocatalysis counterdie and photocatalysis dura mater all select TiO
2film.
When base material 1 adopts plastic sheeting, opposite side relative with described barrier film 2 on described base material 1 is provided with tack coat 6 on the surface, anticlouding element can be combined on glass or minute surface by this tack coat 6.
Material for making this anticlouding element can be selected: polyester (as PETG (PET)), Merlon (PC), allyl diglycol carbonates, polyacrylate (such as polymetylmethacrylate), polysulfone resin, the membrane materials such as polyethersulfone resin.Requirement for this base material is that light transmission is good, can the high temperature of resistance to about 100 DEG C.
The invention also discloses the manufacture method of above-mentioned self-cleaning anti-fog element, wherein, described photocatalysis counterdie 3 and/or photocatalysis dura mater 4 are by middle air pressure air-flow sputtering method deposition.Concrete preparation method is as follows:
A, first, with in air pressure air-flow sputtering method, base material deposits the SiO that one deck 30nm is thick
2film, reaction electric discharge air pressure is 16Pa, and power density is 5W/cm
2;
B, then, at described SiO
2film plates TiO
2film, control Ar/O in reaction
2flow-rate ratio 450: 1, the TiO that plating 50nm is thick
2film;
C, at described TiO
2film plates one deck TiO again
2film, control Ar/O in reaction
2flow-rate ratio 900: 1, the TiO that plating 150nm is thick
2film;
D, again at described TiO
2film plates the SiO that one deck 30nm is thick
2.
When plating above film, if base material is glass, the temperature controlling base material during plated film is about 350 DEG C, if base material is plastics, controlling its temperature is about 100 DEG C.We just obtain and have good hardness like this, and have photocatalysis effect and hydrophilic sample.
The pore structure of film depends on each technological parameter.As in middle air pressure air-flow reactive sputtering, air pressure, discharge power, Ar/O
2ratios etc. all have impact to the structure of film and characteristic.Air pressure is large, and power is low, Ar/O
2ratio is little, and film quality is by more loose, and the ratio that pore volume accounts for membrane volume is also larger, but considers the requirement such as weatherability, intensity of film, and there is Optimal Parameters, inventor obtains air pressure, Ar/O in above-mentioned preparation method through many experiments
2the combination parameter of ratio and power, can reach best effect.
Experiment 1: method detects the photocatalysis effect of anticlouding element by experiment
The photocatalytic activity of photochemical catalyst is evaluated mainly through degradation of methylene blue solution.In plate, add the methylene blue solution of finite concentration certain volume, put into the TiO made
2plated film sample, does light source with 365nm uviol lamp, and distance 20cm irradiates, and every 30min sampling, measures its light transmittance.The conversion of light transmittance and absorbance is realized by absorbance=2-log (%T).According to Beer-Lambert Law, solution concentration and absorbance are good linear relationship at low concentrations.Therefore, the change of degradation process Methylene Blue solution concentration can be calculated with the change of Relative Absorbance value.
Degrading experiment solution used with methylene blue indicator and deionized water formulated, measure the concentration of methylene blue solution by visible spectrophotometer.Due to TiO
2area and the degradation capability thereof of film sample are limited, so must select suitable degradation amount.Simultaneously the concentration exponentially relation of and solution general due to degradation reaction, so under certain degradation amount, must select suitable solution concentration and liquor capacity, to improve conventional efficient.Therefore, first we have prepared the methylene blue solution of three kinds of variable concentrations, by static reaction system, determine respectively at TiO
2under coated glass and blank glass effect, the situation of methylene blue solution absorbance change after ultra violet lamp.By the decomposition rate curve of variable concentrations methylene blue solution under ultra violet lamp, finally determine that the optium concentration of methylene blue solution and optimal volume are 0.02mmol/L, 2mL respectively.
After the optium concentration determining methylene solution and volume, evaluation TiO
2film sample photocatalytic activity mainly relies on ultra violet lamp different time, and the difference of light transmittance judges.Specific practice: be ready to be coated with TiO
2the glass sample of film, utilizes syringe to pipette quantitative methylene blue solution at TiO
2on film, then utilize cover glass to cover solution, utilize packaging plastic surrounding to be sealed, prevent solution evaporation in ultraviolet irradiation process.After sample is carried out, irradiate under being placed in uviol lamp, separated in time sampling and testing, measure the change of light transmittance.
Test anticlouding element under 365nm ultra violet lamp, the decomposition situation of the methylene blue solution of 2mL 0.02mmol/L.Figure 1 shows that common white glass is after ultra violet lamp, the decomposition situation of methylene blue solution, can find out, without the white glass of any process under 365nm ultra violet lamp, to methylene blue solution without decomposition.
Fig. 2 be only have 10nm thick plating loose structure titanium dioxide film glass to the degraded of methylene blue solution, along with the increase of UV-irradiation time, the amount that methylene blue solution is decomposed also increase.
Fig. 3 is four film structure utilizing this patent to propose.Be specially glass SiO
2(30nm) porous TiO
2(50nm) hard TiO
2(150nm) SiO
2(30nm).Can find out that ultraviolet light is very fast to methylene blue decomposition rate.And the contact angle of water is less than 5 degree.Rete overall hardness reaches more than 6H.
Above-described embodiment, only for technical conceive of the present invention and feature are described, its object is to person skilled in the art can be understood content of the present invention and implement according to this, can not limit the scope of the invention with this.All equivalences done according to Spirit Essence of the present invention change or modify, and all should be encompassed within protection scope of the present invention.