阅读说明：本技术 一种随角异色的彩色铝颜料及其制备方法 (Color aluminum pigment with color along with angle and preparation method thereof ) 是由 曹明 夏茹 张媛媛 伍斌 陈鹏 苗继斌 杨斌 苏丽芬 葛倩倩 郑争志 钱家盛 于 2020-05-28 设计创作，主要内容包括：本发明公开了一种随角异色的彩色铝颜料及其制备方法,是首先在碱性的铝颜料溶液中加入多巴胺对铝颜料进行改性,然后再加入有机染料,通过化学接枝法对改性后铝颜料进行着色,即获得随角异色的彩色铝颜料。本发明所获得的彩色铝颜料随角异色性优异、色彩饱和度高、与树脂的相容性好、耐腐蚀性良好,在水性涂料中具有广阔的应用前景。(The invention discloses a color aluminum pigment with color variation along with angles and a preparation method thereof. The color aluminum pigment obtained by the invention has excellent color flop, high color saturation, good compatibility with resin, good corrosion resistance and wide application prospect in water-based paint.)

1. A preparation method of a color aluminum pigment with the color changing along with the angle is characterized in that: firstly, adding dopamine into an alkaline aluminum pigment solution to modify the aluminum pigment, then adding an organic dye, and coloring the modified aluminum pigment by a chemical grafting method to obtain the color aluminum pigment with the color changing along with the angle.

2. The method of claim 1, comprising the steps of:

step 1, pretreatment of aluminum pigment

Weighing 10-20 parts by mass of aluminum pigment, placing the aluminum pigment in a 250mL beaker, adding 250-500 parts by mass of anhydrous ethanol and 50-100 parts by mass of acetone, and performing ultrasonic dispersion uniformly; after the ultrasonic treatment is finished, carrying out suction filtration on the obtained solution, washing a filter cake with distilled water, and then placing the filter cake in a vacuum drying oven at 60 ℃ for drying for 24 hours to obtain a pretreated aluminum pigment;

step 2, modifying the aluminum pigment with dopamine

Weighing 5-10 parts by mass of the pretreated aluminum pigment obtained in the step 1 in a 250mL beaker, adding 450-2300 parts by mass of absolute ethanol, uniformly stirring by magnetic force, immediately adding 1-8 parts by mass of dopamine into the solution, dropwise adding 450-2300 parts by mass of PBS buffer solution with the pH value of 8.5-10.5 and the concentration of 0.01mol/L into the mixed solution at the speed of 1 drop per second, and reacting for 6h at room temperature; after the reaction is finished, carrying out suction filtration on the obtained solution, and washing a filter cake with distilled water to obtain the dopamine modified aluminum pigment;

step 3, coloring of aluminum pigment

Placing the dopamine modified aluminum pigment obtained in the step 2 into a 250mL beaker, immediately adding 450-2300 parts by mass of absolute ethanol and 450-2300 parts by mass of PBS buffer solution with the pH value of 8.5-10.5 and the concentration of 0.01mol/L into the beaker, fully and uniformly stirring, then adding 5-10 parts by mass of organic dye, and reacting for 4-14h at room temperature; and after the reaction is finished, carrying out suction filtration on the obtained solution, washing a filter cake by using distilled water, and then placing the filter cake in a vacuum drying oven at 60 ℃ for drying for 24 hours to obtain the color aluminum pigment with the color changing along with the angle.

3. The method according to claim 1 or 2, characterized in that: the organic dye is disperse orange 11 or sulphur brilliant green GB.

4. A gonioapparent colored aluminum pigment obtained by the method of any one of claims 1 to 3.

Technical Field

The invention relates to a preparation method of a color aluminum pigment, in particular to a preparation method of a color aluminum pigment with a color changing along with an angle.

Background

Aluminum pigments are widely used in industrial coatings due to their excellent metallic properties. However, the aluminum pigment with single color is not enough to meet the requirement of market application, and the aluminum pigment is not resistant to acid and alkali corrosion. Although the corrosion resistance of the aluminum pigment can be remarkably improved by the traditional silica coating modification technology, the performance of the silica modified aluminum pigment such as color flop and color saturation is influenced, and the metallic luster effect of the aluminum pigment is seriously influenced. Meanwhile, the compatibility of the silicon dioxide and the resin is poor, and the silicon dioxide is difficult to uniformly disperse in a coating system. There is therefore a need to find further ways of modifying coloured aluminium pigments.

Disclosure of Invention

Based on the defects of the prior art, the invention aims to provide a preparation method of a color aluminum pigment, and aims to prepare the color aluminum pigment with excellent color flop and high color saturation and improve the compatibility of the aluminum pigment and resin.

In order to realize the purpose of the invention, the following technical scheme is adopted:

a preparation method of a color aluminum pigment with the color changing along with the angle is characterized in that: firstly, adding dopamine into an alkaline aluminum pigment solution to modify the aluminum pigment, then adding an organic dye, and coloring the modified aluminum pigment by a chemical grafting method to obtain the color aluminum pigment with the color changing along with the angle. The method specifically comprises the following steps:

step 1, pretreatment of aluminum pigment

Weighing 10-20 parts by mass of aluminum pigment, placing the aluminum pigment in a 250mL beaker, adding 250-500 parts by mass of anhydrous ethanol and 50-100 parts by mass of acetone, and performing ultrasonic dispersion uniformly; after the ultrasonic treatment is finished, carrying out suction filtration on the obtained solution, washing a filter cake with distilled water, and then placing the filter cake in a vacuum drying oven at 60 ℃ for drying for 24 hours to obtain a pretreated aluminum pigment;

step 2, modifying the aluminum pigment with dopamine

Weighing 5-10 parts by mass of the pretreated aluminum pigment obtained in the step 1 in a 250mL beaker, adding 450-2300 parts by mass of absolute ethanol, uniformly stirring by magnetic force, immediately adding 1-8 parts by mass of dopamine into the solution, dropwise adding 450-2300 parts by mass of PBS buffer solution with the pH value of 8.5-10.5 and the concentration of 0.01mol/L into the mixed solution at the speed of 1 drop per second, and reacting for 6h at room temperature; after the reaction is finished, carrying out suction filtration on the obtained solution, and washing a filter cake with distilled water to obtain the dopamine modified aluminum pigment;

step 3, coloring of aluminum pigment

Placing the dopamine modified aluminum pigment obtained in the step 2 into a 250mL beaker, immediately adding 450-2300 parts by mass of absolute ethanol and 450-2300 parts by mass of PBS buffer solution with the pH value of 8.5-10.5 and the concentration of 0.01mol/L into the beaker, fully and uniformly stirring, then adding 5-10 parts by mass of organic dye, and reacting for 4-14h at room temperature; and after the reaction is finished, carrying out suction filtration on the obtained solution, washing a filter cake by using distilled water, and then placing the filter cake in a vacuum drying oven at 60 ℃ for drying for 24 hours to obtain the color aluminum pigment with the color changing along with the angle.

Further, the organic dye is disperse orange 11 or sulphur brilliant green GB.

Compared with the prior art, the invention has the beneficial effects that:

the color aluminum pigment prepared by modifying the surface of the aluminum pigment with dopamine and chemically grafting the organic dye has good corrosion resistance, excellent color flop and high color saturation, is well compatible with the water-based acrylic resin, and has wide application prospect in water-based paint.

Drawings

In FIG. 1, a, b and c are FTIR graphs of unmodified aluminum pigment, dopamine modified aluminum pigment and colored aluminum pigment colored by disperse orange 11 dye in example 1;

in FIG. 2, a, b and c are SEM images of an unmodified aluminum pigment, a dopamine modified aluminum pigment and a colored aluminum pigment colored by a disperse orange 11 dye in example 1;

in FIG. 3, a, b and c are XPS charts of the unmodified aluminum pigment, the dopamine modified aluminum pigment and the colored aluminum pigment colored by the disperse orange 11 dye in example 1;

FIG. 4 is a test of the acid resistance of the unmodified aluminum pigment and the colored aluminum pigment colored with disperse orange 11 dye of example 1.

FIG. 5 is a graph showing the measurement of the contact angle of a coating film formed by mixing an aluminum pigment and an aqueous acrylic paint, wherein: fig. 5a is a graph showing the measurement of the contact angle of a mixed coating film of an unmodified aluminum pigment and a water-based acrylic paint, fig. 5b is a graph showing the measurement of the contact angle of a mixed coating film of a dopamine-modified aluminum pigment and a water-based acrylic paint, and fig. 5c is a graph showing the measurement of the contact angle of a mixed coating film of a color aluminum pigment colored with a disperse orange 11 dye and a water-based acrylic paint in example 1.

Detailed Description

The following examples are given for the detailed implementation and specific operation of the present invention, but the scope of the present invention is not limited to the following examples.

In the following examples, the acid and corrosion resistance of aluminum pigments was tested according to the industry standard HG/T2456.1-2013: 0.1g of aluminum pigment is weighed and placed in 50mL of 0.1mol/L HCl solution, hydrogen released within 72 hours is collected by a drainage and gas collection method, and the acid resistance of the aluminum pigment is judged according to the volume of the hydrogen.