Unlock instant, AI-driven research and patent intelligence for your innovation.

Reversible photochromic coating and preparation method thereof

A photochromic and coating technology, applied in the field of color-changing materials, can solve the problems of poor color-changing effect, low efficiency, and reduced color-changing and fading efficiency.

Active Publication Date: 2019-03-29
CHINA UNIV OF PETROLEUM (BEIJING)
View PDF4 Cites 5 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the composition of the coating is simple, and the drying process is difficult to control, resulting in the agglomeration of the color-changing powder during the drying process, which loses the special properties of the nano-powder, resulting in a decrease in the photoresponse performance; specifically, when photochromism occurs, most of the particles are due to Being shielded leads to the inability to achieve discoloration, resulting in poor discoloration effect, low efficiency and slow discoloration speed
On the other hand, capillary action is the only water-locking method in the above-mentioned coating system. The powder absorbs and fixes a small amount of water through capillary action. The amount of water locked is limited, which makes the water content of the coating system low, and the lack of water also leads to a decrease in the efficiency of discoloration and fading.
In addition, the reversibility of the photochromic powder’s discoloration needs to be achieved by oxidation. In a natural open environment, it depends on the oxygen in the air to achieve fading, and the efficiency is low. In the absence of oxidants under sealed conditions, the fading efficiency is lower.
Therefore, the existing photochromic coatings have poor discoloration effect, low efficiency, and low fading efficiency, that is, their light response performance is poor, which limits the application occasions and scope of photochromic coatings.
In addition, the coating film of existing coatings is poor in firmness. The actual coating film is nano-powders fixed to each other and to the coating carrier by van der Waals force, which lacks firmness and is easy to weather and peel off or wash off.

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Reversible photochromic coating and preparation method thereof
  • Reversible photochromic coating and preparation method thereof
  • Reversible photochromic coating and preparation method thereof

Examples

Experimental program
Comparison scheme
Effect test

preparation example Construction

[0060] The present invention also provides a method for preparing the reversible photochromic coating described in the above technical solution, comprising the following steps:

[0061] A) mixing the color-changing powder suspension with the dispersant solution to obtain a mixed solution a;

[0062] B) Mixing the mixed solution a with the aqueous polymer dispersion to obtain a reversible photochromic coating.

[0063] According to the present invention, the color-changing powder suspension is first mixed with the dispersant solution to obtain the mixed solution a.

[0064] Wherein, the color-changing powder suspension is a suspension formed by dispersing the color-changing powder in a solvent. The type, content and source of the color-changing powder and solvent are consistent with those described in the above technical solution, and will not be repeated here. In the present invention, the mass concentration of the color changing powder suspension is preferably 20wt%-25wt%. ...

Embodiment 1

[0083] 1.1 Sample preparation

[0084] With 0.0318g photochromic powder suspension (concentration is 25wt%, color-changing powder is nanometer MoO 3 ) into the reagent bottle, add 0.7105g polyvinyl alcohol aqueous solution (concentration is 5wt%, polyvinyl alcohol weight average molecular weight is 80000), and ultrasonically vibrate at room temperature for 1 minute.

[0085] Add 1.5859g of water-based alkyd resin (8.5wt% solid content, model STW-301), and ultrasonically vibrate at room temperature for 3 minutes.

[0086] Add 0.0828g polyacrylic acid aqueous solution (concentration: 10wt%, polyacrylic acid weight-average molecular weight: 3000), ultrasonically oscillate uniformly to obtain reversible photochromic coating.

[0087] After repeated suction and homogenization by the test tube, draw an appropriate amount of paint and apply it on a glass slide (the glass slide is rinsed with deionized water and dried in advance), and dry in the shade in the dark to form a 1mm thick ...

Embodiment 2

[0096] With 0.0294g photochromic powder suspension (concentration is 25wt%, color-changing powder is nanometer TiO 2 ) into the reagent bottle, add 0.6588g polyvinyl alcohol aqueous solution (concentration is 5wt%, polyvinyl alcohol weight average molecular weight is 80000), and ultrasonically vibrate at room temperature for 1 minute.

[0097] Add 1.4688g of water-based styrene-acrylic emulsion (solid content is 15wt%, model is KL-420), and ultrasonically vibrate at room temperature for 3 minutes.

[0098] Add 0.0770g polyacrylic acid aqueous solution (concentration: 10wt%, polyacrylic acid weight-average molecular weight: 3000), ultrasonically oscillate evenly to obtain reversible photochromic coating.

[0099] The above paint was processed according to the method of Example 1 to obtain a reversible photochromic paint smear.

[0100] The performance test was carried out according to the sample test method in Example 1, and the test results are shown in Table 1.

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

No PUM Login to View More

Abstract

The invention provides a reversible photochromic coating and a preparation method thereof. The coating provided by the invention comprises: 0.2% to 5% of a color changing powder, 1% to 5% of a dispersing agent, 4% to 15% of a dispersible polymer, and the balance a solvent, wherein the dispersing agent is one or more ingredients selected from the group consisting of starch, cellulose, vegetable gum, animal glue and polymer A; the polymer A includes one or more compounds selected from the group consisting of polyacrylamide, hydrolyzed polyacrylamide, polyvinylpyrrolidone and polyvinyl alcohol; the dispersible polymer includes one or more compounds selected from the group consisting of polyurethane, a styrene-acrylic emulsion, polyacrylic acid, alkyd resin, hydroxy cellulose, polyvinyl alcohol, polyacrylate and a copolymer B; the copolymer B is a copolymer formed by copolymerizing two or more compounds selected from the group consisting of polyurethane, a styrene-acrylic emulsion, polyacrylic acid, alkyd resin, hydroxy cellulose, polyvinyl alcohol and polyacrylate. The coating of the invention can significantly improve discoloration fading efficiency and coating performance.

Description

technical field [0001] The invention relates to the technical field of color-changing materials, in particular to a reversible photochromic coating and a preparation method thereof. Background technique [0002] Reversible photochromic coatings are functional materials with certain photoresponsive properties. Specifically, they can change color after being excited by a light source, and gradually restore the color after the light source is removed. As a functional primer, this type of coating can be widely used in visible light marking, such as laser scribing, optical drawing reusable drawing board, self-weight color spray, and anti-counterfeiting and other fields. [0003] At present, common photochromic coatings are mainly suspensions of photochromic powders, which are directly painted or coated in other ways during use. However, the composition of the coating is simple, and the drying process is difficult to control, resulting in the agglomeration of the color-changing p...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
IPC IPC(8): C09D167/08C09D125/14C09D175/04C09D133/04C09D7/61C09D7/65C09D5/29
CPCC08K2003/2241C08K2003/2255C08K2201/011C08L2205/03C09D5/29C09D7/61C09D7/65C09D125/14C09D133/04C09D167/08C09D175/04C08L29/04C08L33/02C08K3/22C08L31/04C08L1/284
Inventor 李勃天李宁张一弛
Owner CHINA UNIV OF PETROLEUM (BEIJING)