CN106916481B

CN106916481B - Photocatalyst additive and application method of hydrophilic coating containing same

Info

Publication number: CN106916481B
Application number: CN201710140605.4A
Authority: CN
Inventors: 袁俊军; 付裕; 王飞; 张明杰
Original assignee: Qingdao Haier Air Conditioner Gen Corp Ltd
Current assignee: Qingdao Haier Air Conditioner Gen Corp Ltd; Haier Smart Home Co Ltd; Qingdao Haier Jiaozhou Air Conditioner Co Ltd
Priority date: 2017-03-10
Filing date: 2017-03-10
Publication date: 2020-08-04
Anticipated expiration: 2037-03-10
Also published as: CN106916481A

Abstract

The invention discloses a photocatalyst additive, which is a nano-scale dioxide doped with cerium Ce, vanadium V and sulfur STitanium TiO 2₂. The hydrophilic coating with the photocatalyst additive can play an excellent role in removing formaldehyde; in addition, the invention also provides a using method of the hydrophilic coating added with the photocatalyst additive, and provides coating thicknesses corresponding to aluminum foils with different thicknesses when the hydrophilic coating is used for the aluminum fins of air conditioners.

Description

Photocatalyst additive and application method of hydrophilic coating containing same

Technical Field

The invention relates to the technical field of coating materials, in particular to a photocatalyst additive and a use method of a hydrophilic coating containing the same.

Background

The photocatalyst is nano titanium dioxide (TiO)₂) The general name of the representative photo-semiconductor material with the photocatalytic function is that the photo-semiconductor material is coated on the surface of a substrate and generates strong catalytic degradation function under the action of ultraviolet rays: can effectively degrade toxic and harmful gases in the air; can effectively kill various bacteria and decompose and harmlessly treat toxins released by bacteria or fungi; meanwhile, the composite material also has the functions of removing formaldehyde, deodorizing, resisting pollution, purifying air and the like. The photocatalyst technology is that professor of Tokyo university in 1967 establishes a professor and studies that the titanium dioxide electrode can decompose water into hydrogen and oxygen under the irradiation of ultraviolet rays accidentally under the research of the Tanskia island showa at that time. Under the irradiation of light, valence band electrons are excited to conduction band by nano titanium dioxide photocatalyst to form electrons and holes, and O adsorbed on its surface₂And H₂O acts to generate superoxide anion free radical, O2-and hydroxyl free radical-OH, the free radical has strong oxidative decomposition capability and can destroy C-C bond, C-H bond, C-N bond, C-O bond, O-H bond and N-H bond in organic matters to decompose the organic matters into carbon dioxide and water; meanwhile, the cell membrane of the bacteria is damaged to solidify the protein of the virus, and the living environment of the bacteria and the virus is changed, so that the bacteria and the virus are killed.

Although the doping research on the nano titanium dioxide is more in the prior art, the research on the nano titanium dioxide used in the hydrophilic coating is less.

Disclosure of Invention

The embodiment of the invention provides a photocatalyst additive and a using method of a hydrophilic coating containing the same. The following presents a simplified summary in order to provide a basic understanding of some aspects of the disclosed embodiments. This summary is not an extensive overview and is intended to neither identify key/critical elements nor delineate the scope of such embodiments. Its sole purpose is to present some concepts in a simplified form as a prelude to the more detailed description that is presented later.

According to a first aspect of embodiments of the present invention, there is provided a photocatalyst additive.

In some exemplary embodiments, the catalyst additive is nano-TiO doped with cerium (Ce), vanadium (V), and sulfur (S)₂。

In some optional embodiments, the photocatalyst additive comprises the following components in parts by weight:

0.01 to 10 percent of cerium Ce;

0.01 to 10 percent of vanadium V;

0.01 to 10 percent of sulfur S;

the balance of nano TiO₂。

In some illustrative embodiments, the photocatalyst additive is further doped with at least one of tungsten (W) and nitrogen (N).

In some illustrative embodiments, the tungsten W and nitrogen N in the photocatalyst additive are comprised of, by weight:

0-10% of tungsten W;

n is 0-10%.

In some illustrative embodiments, the photocatalyst additive comprises the following components in parts by weight:

the above embodiment provides a photocatalyst additive for the surface of an aluminum fin of an air-conditioning heat exchanger, and a hydrophilic coating containing the photocatalyst additive can form a hydrophilic film with a formaldehyde-removing effect after being dried.

According to a second aspect of embodiments of the present invention, there is provided a method of using a hydrophilic coating,

in some exemplary embodiments, the hydrophilic coating contains the photocatalyst additive as described in any one of claims 1 to 5, and before the air-conditioning aluminum fin is molded, the hydrophilic coating is coated on the surface of the air-conditioning aluminum fin, and after drying, a film with photocatalyst and hydrophilicity is formed on the surface of the air-conditioning aluminum fin; wherein the coating amount of the hydrophilic coating is as follows: 1mg/m²-100mg/m²。

In some illustrative embodiments, the hydrophilic coating is applied as a photocatalytic topcoat to the aluminum fin of an air conditioning heat exchanger.

In some illustrative embodiments, the thickness of the film is related to the aluminum foil thickness of the air conditioner heat exchanger aluminum fin.

In some illustrative embodiments, the oven dried film is at a temperature of 80 ℃ to 300 DEG C

The above embodiments provide methods of using hydrophilic coatings for air conditioning aluminum fins.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and together with the description, serve to explain the principles of the invention.

FIG. 1 is a graph illustrating formaldehyde decomposition effects of a hydrophilic coating with a photocatalyst additive, according to an exemplary embodiment.

Detailed Description

The following description and the drawings sufficiently illustrate specific embodiments of the invention to enable those skilled in the art to practice them. The examples merely typify possible variations. Portions and features of some embodiments may be included in or substituted for those of others. The scope of embodiments of the invention encompasses the full ambit of the claims, as well as all available equivalents of the claims. Embodiments may be referred to herein, individually or collectively, by the term "invention" merely for convenience and without intending to voluntarily limit the scope of this application to any single invention or inventive concept if more than one is in fact disclosed.

Although the research on doping elements of nano titanium dioxide is more in the prior art, the nano titanium dioxide is used for doping hydrophilic coatings, and the research is less at present; the reason is mainly that the corrosion resistance, the hydrophilicity, the heat resistance and other related properties of the hydrophilic coating are affected due to different doping elements. And improper selection or proportioning of the doping elements can greatly impair the performance of the hydrophilic coating. Furthermore, different doping elements also have a great influence on the aging behavior of the hydrophilic coating. Therefore, the selection and the proportion of different elements become technical difficulties in the field.

In some exemplary embodiments, the photocatalyst additive is used for a hydrophilic coating, and the photocatalyst additive is nano-titanium dioxide (TiO) doped with cerium (Ce), vanadium (V) and sulfur (S)₂. By adding nano TiO 2₂The cerium Ce, the vanadium V and the sulfur S are doped, so that the formaldehyde decomposition effect of the hydrophilic coating can be improved, in addition, the two elements are added, the performance of the hydrophilic coating cannot be reduced, and a film coated by the hydrophilic coating has hydrophilicity, corrosion resistance, heat resistance and alkali resistance.

Wherein the photocatalyst additive is prepared by a sol-gel method; the specific method comprises the following steps: slowly adding a mixed solution of 34ml of tetrabutyl titanate and 70ml of absolute ethyl alcohol which are uniformly stirred under magnetic stirring at room temperature into a mixed solution of cerium nitrate, vanadium nitrate and sulfur-containing S ionic liquid with different molar masses, hydrolyzing in a mixed solution of 30ml of absolute ethyl alcohol, 35ml of glacial acetic acid and 15ml of deionized water, stirring for 1.5h to obtain a uniform and transparent sol, aging to obtain a gel, then placing the gel in a vacuum drying chamber at 80 ℃ to obtain a dried gel, grinding the gel, placing the gel in a box-type resistance furnace, and calcining for 2h at different calcining temperatures to obtain the metal-doped nano titanium dioxide TiO 2₂(ii) a The ionic liquid is hydrophilic ionic liquid and can be triethylamine sulfuric acidA hydrogen salt.

Although the prior art has many researches on doping nano-titanium dioxide, the researches on the use of nano-titanium dioxide in hydrophilic coatings are few, and the reason is that the corrosion resistance, hydrophilicity, heat resistance, alkali resistance and other related performances of the hydrophilic coatings are influenced due to different doping elements. If the choice or proportion is not proper, such as the improper addition of vanadium (V), the corrosion resistance, hydrophilicity, heat resistance, and alkali resistance of the hydrophilic coating are greatly impaired. Furthermore, different doping elements have a great influence on the aging behavior of the hydrophilic coating. Therefore, the selection and the proportion of different elements are strictly controlled and are also one of the technical difficulties.

0.01 to 10 percent of cerium Ce;

0.01 to 10 percent of vanadium V;

0.01 to 10 percent of sulfur S;

the balance of nano TiO₂。

Preferably, the cerium Ce may have a composition of 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8% or 9% by weight; the vanadium V may be 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8% or 9% in parts by weight; the sulfur S may be comprised of 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8% or 9% by weight.

In some illustrative embodiments, the nano-titanium dioxide TiO₂The photocatalyst additive comprises the following components in parts by weight: 50 to 90 percent.

In some illustrative embodiments, the photocatalyst additive is further doped with at least one of tungsten W and nitrogen N. By doping one or more elements of tungsten W and nitrogen N, the nano TiO can be optimized₂The performance of the photocatalyst is improved, and the nanometer titanium dioxide TiO is improved₂The forbidden band width of the catalyst enables the response spectrum of the reaction to be expanded to visible light, and is beneficial to enhancing the absorption of the catalyst to the visible light and the charge carrying.

In the above process, if the photocatalyst additive is further doped with one or more elements of tungsten W and nitrogen N, ammonium tungstate and nitrogen N-containing ionic liquid are added in the above process of preparing the photocatalyst additive by the sol-gel method; wherein the sulfur-containing ionic liquid can be triethylamine bisulfate; the carbon-containing C ionic liquid can be 1-amino-3-alkyl-1, 2, 3-triazole nitrate.

0-10% of tungsten W;

n is 0-10%.

Preferably, the composition of the tungsten W in parts by weight may be 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8% or 9%; the composition of the nitrogen N in parts by weight can be 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8% or 9%.

the above examples respectively show the conditions of the preferred component ratio of the photocatalyst additive, and the performance of the hydrophilic coating containing the photocatalyst additive after film formation in the above two examples is tested, and the test method and results are as follows:

table 1 gives the composition of the different samples in the experimental and reference groups;

in the test, the experimental group and the reference group have the same treatment process except that the components are different; the treatment process comprises the following specific steps:

1. pretreating the surface to be detected and the surface of a 1000mm aluminum foil; the pretreatment comprises the following steps: degreasing process and priming process; wherein the degreasing process comprises the following steps: the degreasing agent is coated and then washed twice, and then dried, and in the test, the degreasing agent is an FC-315 degreasing agent provided by Paka surface treatment technology (Shanghai) Co., Ltd; the base coating process comprises the following steps: coating a corrosion-resistant bottom layer on the surface of the aluminum foil subjected to degreasing process, and then drying at 230 ℃ to form a film, wherein the film coating amount is controlled to be 95-100mg/m²The chemical treatment agent for the corrosion-resistant bottom layer is SG-E902 chemical treatment agent provided by Paka surface treatment technology (Shanghai) Co., Ltd;

2. carrying out surface coating on the aluminum foil subjected to surface pretreatment, and coating a photocatalyst surface layer; according to Table 1, hydrophilic coating materials of different compositions, namely examples A to C and the reference sample, were respectively roll-coated on the surface of aluminum foil, dried at 230 ℃ and controlled to a coating amount of 40 to 45mg/m²；

3. Evaluating the membrane performance of the experimental group and the control group;

the evaluation of the film properties was mainly investigated for several parameters: hydrophilicity, stain resistance, adherence, heat resistance, corrosion resistance, antibacterial properties, and pollutant-degrading ability; wherein the pollutant degradation capability is the capability of degrading formaldehyde by photocatalysis to pollutants; the specific evaluation methods are shown in Table 2.

TABLE 1 Experimental and control groups

Table 2 evaluation items and evaluation methods

Table 3 evaluation results of film properties

Sample number

Hydrophilicity

Resistance to soiling

Adhesion property

Heat resistance

Corrosion resistance

Antibacterial property

Formaldehyde (I)

Example A

○

Example B

○

Example C

○

Reference sample

○

△

×

In Table 3, ○ represents that the performance is good and meets the requirement, △ represents that the performance is general but qualified, and × represents that the performance is not qualified;

as can be seen from Table 3, the examples A, B and C have good performance, not only meet the requirements of the aluminum foil on the performance of the coated film, but also have the effect of decomposing formaldehyde; while ordinary nano TiO 2₂Although the hydrophilicity meets the requirement, the anti-fouling property, the adherence, the heat resistance, the corrosion resistance and the antibacterial property are common, and the formaldehyde can not be decomposed basically, so that the requirement of the aluminum foil on the photocatalyst coating can not be met;

in the process, the photocatalytic degradation performance of the pollutants is evaluated by quantitatively coating the pollutants on a treatment material subjected to an experiment, and carrying out quantitative analysis by means of FT-IR after light irradiation.

The specific analysis steps are as follows:

A. contaminant coating

Uniformly coating pollutants on a treatment material subjected to an experiment in a quantitative manner by a wire bar coater, and drying the treatment material in a constant-temperature oven at 80 ℃ until the weight is constant;

B. irradiation with visible light

Placing the experimental material coated with the pollutants in an indoor visible light environment and in a simulated visible light lamp box to perform irradiation for a specified time; wherein the irradiation intensity is 0.5mW/cm²Irradiation area of 50cm²The ambient temperature is 28 ℃ and the ambient humidity is 50%;

C. quantitative analysis

And (3) carrying out FT-IR analysis on the experimental materials before and after the visible light irradiation, carrying out quantitative integration on characteristic peaks of the pollutants, and calculating the photodegradation rate.

The results of examples A, B, C and the reference, respectively, on formaldehyde decomposition are detailed in FIG. 1;

as can be seen from fig. 1, the example a (coating a), the example B (coating B) and the example C (coating C) all have better effect on decomposing formaldehyde, and the formaldehyde decomposition rates of different proportions are similar, as long as the cerium Ce, the vanadium V and the sulfur S are contained, they all have good effect on decomposing formaldehyde; however, the reference sample had a poor decomposition effect and was almost unable to decompose the above-mentioned pollutants efficiently.

The above embodiment provides a hydrophilic coating with a photocatalyst additive for the surface of an aluminum fin of an air-conditioning heat exchanger, and the hydrophilic coating can form a hydrophilic film with a formaldehyde-removing effect after being dried.

According to a second aspect of embodiments of the present invention, there is provided a method of using a hydrophilic coating;

in some exemplary embodiments, the hydrophilic coating contains the photocatalyst additive as described in the above embodiments, and the hydrophilic coating is coated on the surface of the air-conditioning aluminum fin before the air-conditioning aluminum fin is formed, and dried to form the surface of the air-conditioning aluminum finA film having photocatalytic properties and hydrophilic properties; wherein the coating amount of the hydrophilic coating is as follows: 1mg/m²-100mg/m²。

Optionally, the hydrophilic coating is applied in an amount of 10mg/m²、20mg/m²、30mg/m²、40mg/m²、50mg/m²、60mg/m²、70mg/m²、80mg/m²Or 90mg/m². The coating amount is to exert the photocatalyst performance of the involucra to the maximum extent on the premise of ensuring that the hydrophilic coating is not influenced by aging or deterioration, thereby ensuring that the air conditioner realizes self-cleaning functions of antibiosis, oil stain removal and the like in the using process. Too low addition affects the performance of the photocatalyst, and too high addition affects the performance of the hydrophilic coating. Such as hydrophilicity, corrosion resistance, heat resistance, alkali resistance, adhesion, and the like.

In the present invention, the hydrophilic coating material to which the photocatalyst additive is added may be used as it is or after being diluted with water, and the concentration and viscosity of the treatment liquid should be appropriately adjusted to meet the operation method and the film thickness requirement.

Preferably, the film thickness after drying is 0.05 to 5 μm, more preferably: 0.1 to 2 μm, when the film thickness is less than 0.05. mu.m, it is difficult to provide satisfactory photocatalyst and hydrophilic properties, and when the film thickness exceeds 5 μm, thermal conductivity and film adhesion may be lowered.

In some illustrative embodiments, the hydrophilic coating is applied as a photocatalytic topcoat to the aluminum fin of an air conditioning heat exchanger. The hydrophilic coating provided by the embodiment of the invention is mainly developed for coating the aluminum fin of the heat exchanger of the air conditioner, so that the components of the photocatalyst additive and the coating method of the hydrophilic coating are provided for being applied to the environment.

In some illustrative embodiments, if the aluminum foil of the aluminum fin of the air conditioner heat exchanger has a thickness of 1000mm, the film thickness of the hydrophilic coating after coating is 0.05-2 μm; if the thickness of the aluminum foil of the aluminum fin of the air-conditioning heat exchanger is 3000mm, the film thickness of the hydrophilic coating after coating is 0.05-5 mu m; if the thickness of the aluminum foil of the aluminum fin of the air-conditioning heat exchanger is 8000mm, the film thickness of the hydrophilic coating after coating is 0.05-8 mu m. The thickness of the film directly influences the performance of the film, and the film is difficult to provide satisfactory photocatalytic performance and hydrophilicity due to the fact that the film is too thin, and the film is poor in thermal conductivity and poor in film adhesion due to the fact that the film is too thick; on the premise of ensuring that the hydrophilic coating can provide excellent photocatalytic performance, hydrophilic performance, aging resistance, pollution resistance and the like after being coated, the film thickness of the hydrophilic coating corresponding to different series of aluminum foils is provided in the embodiment.

In some optional embodiments, before the hydrophilic coating is applied, the method further comprises performing pretreatment on the surface of the aluminum fin of the air conditioner heat exchanger to improve the corrosion resistance of the surface.

In some alternative embodiments, the method of pre-treatment, preferably by chemical conversion, is based on, for example: chemical treatment of zirconium phosphate, titanium phosphate, vanadium phosphate or organic-inorganic hybrid; preferably, the corrosion-resistant bottom layer can be formed on the surface of the air conditioner heat exchanger fin through organic-inorganic hybrid chemical treatment.

In some illustrative embodiments, the hydrophilic coating has a film forming temperature of 80 to 300 ℃.

In some optional embodiments, the coated hydrophilic coating is dried at 80-300 ℃ by a hot air circulation oven, a heat radiation oven or the like; preferably, the hydrophilic coating is dried at a temperature of 100 ℃ and 260 ℃.

In some alternative embodiments, since the hydrophilic coating is hydrophilic and thus the solvent for dissolving the hydrophilic coating is mainly composed of water, a water-soluble solvent such as alcohol, alcohol ether solvent, etc. may be used in order to adjust the drying speed, improve the state of the coating film, or increase the solubility of the components. Further, one or more of rust inhibitors, chelating agents, fillers, colorants, defoaming agents and the like may also be added to the components of the hydrophilic coating in an amount within a range not to impair the gist of the present invention and film properties.

In some illustrative embodiments, the method of applying the hydrophilic coating comprises: dip coating, spray coating, brush coating, roller coating, flow coating esters, electrochemical deposition and chemical deposition; the roll coating in the industrial production is preferably used.

In some optional embodiments, in the photocatalyst hydrophilization treatment method, the surface of the metal material can be subjected to degreasing and surface pretreatment which are conventional in the current industrial production; subsequently, a photocatalytic hydrophilic coating is deposited on the surface of the metal material, and then heated and dried to form a film.

The embodiment provides a using method of the hydrophilic coating used for the air conditioner aluminum fin, and provides coating thicknesses corresponding to aluminum foils with different thicknesses.

It is to be understood that the present invention is not limited to the procedures and structures described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the invention is limited only by the appended claims.

Claims

1. A photocatalyst additive for hydrophilic coating is characterized in that the photocatalyst additive is nano TiO 2 doped with Ce, V and S₂(ii) a The nano TiO₂Further doped with at least one element of tungsten W and nitrogen N;

the photocatalyst additive comprises the following components in parts by weight: ce is 0.01% -10%; v is 0.01 to 10 percent; 0.01 to 10 percent of S; w is 0-10%; n is 0-10%; the balance of nano TiO₂。

2. The photocatalyst additive as defined in claim 1, wherein the photocatalyst additive is composed of, in weight fractions: ce is 8%; v is 0.07%; n is 0.06%; s is 2%; the balance of nano TiO₂。

3. A method for using a hydrophilic coating, wherein the hydrophilic coating contains the photocatalyst additive as described in claim 1 or 2, and before forming an air-conditioning aluminum fin, the hydrophilic coating is applied to the surface of the air-conditioning aluminum fin, and after drying, a film having photocatalyst property and hydrophilicity is formed on the surface of the air-conditioning aluminum fin; wherein the coating amount of the hydrophilic coating is as follows: 1 mg/square meter to 100 mg/square meter.

4. The use of claim 3, wherein the thickness of the film is related to the thickness of the aluminum foil of the aluminum fin of the air conditioning heat exchanger.

5. The use of claim 3, wherein the temperature of said film dried is from 80 ℃ to 300 ℃.