Preparation of reflective image component and application method thereof

Patent metadata

Field	Value
Publication number	US-11060177-B2
Application number	US-201715730722-A
Country	US
Kind code	B2
Filing date	Oct 11, 2017
Priority date	Oct 12, 2016
Publication date	Jul 13, 2021
Grant date	Jul 13, 2021

Abstract

The present invention discloses preparation of a reflective image component and application method thereof. A reflective image component in the present invention consists of a metallic semi-continuous thin film, a porous alumina film and a high reflective metal substrate. The structure is easy in preparation, low in cost, environmental friendly regarding preparing procedures and suitable for large-scale fabrication, which plays a significant role in developing a next generation of image component; the minimum pixel in the image obtained is able to reach nano level, much smaller than the pixel in most of the self-luminous screens at present; the image also provides the ability of reversible color transformations, which can be applied to information encryption and trademark decoration and the like.

First claim

What is claimed is:

1. A preparation method for a reflective image component, comprising:
a. cleaning of an aluminum sheet: soaking an aluminum sheet with a thickness of more than 0.1 mm in acetone for 5˜15 mins; then soaking the aluminum sheet in the 0.5˜1.5 mol/L sodium hydroxide solution for 5˜15 mins, and finally soaking the aluminum sheet in ethanol for 5˜15 mins;
b. polishing of the aluminum sheet: putting the soaked aluminum sheet into a mixed solution of perchloric acid and ethanol with 15%˜35% of perchloric acid to ethanol (v/v), electrochemical polishing the aluminum sheet under a voltage of 10˜30 volts for 2˜6 mins under 0˜4° C.;
c. a first oxidation of the aluminum sheet: putting the polished aluminum sheet into an electrolyte pool with 0.1˜0.3 mol/L oxalic acid; the aluminum sheet is used as an anode and the platinum sheet is used as a cathode; a growth voltage is 30˜50 volts, oxidation time is 2˜8 hours, and an oxidation temperature is 4˜8° C.;
d. etching of the aluminum sheet: putting the first oxidized aluminum sheet into a mixture of chromic acid, phosphoric acid and water for 60˜90 mins under 45˜75° C.;
e. a second oxidation of the aluminum sheet: putting the etched aluminum sheet into the electrolyte pool with 0.1˜0.3 mol/L oxalic acid solution, the aluminum sheet is used as an anode and the platinum sheet is used as a cathode, an oxidation voltage is 30˜50 volts, the oxidation time is 80˜600 s, and the oxidation temperature is 4˜8° C.;
f. exposing of an image by photolithography: spin-coating a photoresist in advance on the surface of a porous aluminum template formed after the second oxidation of an aluminum sheet, and then exposing an image by a photolithography system;
g. modulation of a pore diameter of a porous alumina template: putting a photolithography-exposed aluminum template into 0.3 mol/L oxalic acid solution, keeping a temperature at 40˜60° C., soaking for 0˜360 mins to obtain a porous alumina template with a first pore diameter, then removing the photoresist, and then changing the first pore diameter of the porous alumina template by soaking the porous alumina template into 0.3 mol/L oxalic acid solution, keeping a temperature at 40˜60° C., and soaking for 2.5˜360 mins to enlarging the first pore diameter into a second pore diameter; and
h. sputtering of a thin film: using a metal target material to sputter the thin film on the porous alumina template by a sputtering device, to obtain the reflective image component; a sputtering current is 3˜100 mA and sputtering time is 50˜300 seconds.

2. The preparation method for a reflective image component according to claim 1 , wherein a mass fraction of the chromic acid in the mixture in the step d is 1˜3%, a mass fraction of the phosphoric acid in the step d is 4˜8% and a balance is water.

3. The preparation method for a reflective image component according to claim 1 , wherein a thickness of the porous alumina template in the step f is 200˜1000 nm.

4. The preparation method for a reflective image component according to claim 1 , wherein the target material provided in the sputtering device in the step h is a gold target, a silver target or an aluminum target.

5. The preparation method for a reflective image component according to claim 1 , wherein the sputtered thin film consists of a metallic semi-continuous film, a porous alumina film and a metal substrate.

Assignees

• Univ Sun Yat Sen

Inventors

• Zhou Zhangkai
• Xue Jiancai
• Wei Zhiqiang

Classifications

• C25F3/20

  of aluminium · CPC title

• C25D11/10

  containing organic acids · CPC title

• C23C14/021 Primary

  Cleaning or etching treatments · CPC title

• C25D11/16

  Pretreatment {, e.g. desmutting} · CPC title

• C25D11/12 Primary

  Anodising more than once, e.g. in different baths · CPC title