CN113105756B

CN113105756B - Carbon-coated titanium pearlescent pigment and preparation method thereof

Info

Publication number: CN113105756B
Application number: CN202110436137.1A
Authority: CN
Inventors: 费明; 林学周; 邱玉琴; 谢秉昆
Original assignee: Fujian Kuncai Material Technology Co ltd
Current assignee: Fujian Kuncai Material Technology Co ltd
Priority date: 2021-04-22
Filing date: 2021-04-22
Publication date: 2021-11-16
Anticipated expiration: 2041-04-22
Also published as: CN113105756A

Abstract

The invention relates to the technical field of pearlescent pigments, in particular to a carbon-coated titanium pearlescent pigment and a preparation method thereof. The preparation method of the carbon-coated titanium pearlescent pigment comprises the following steps: adding a polymer monomer into a reaction system of the titanium oxychloride and the carbonate so as to enable the polymer monomer to be subjected to polymerization reaction. The polymer monomer is added into a reaction system in which the titanium dioxide is formed by the reaction of the titanium oxychloride and the carbonate, so that when the titanium oxychloride and the carbonate react, the polymer monomer also carries out polymerization reaction to form a polymer, and then the polymer can coat the formed titanium dioxide, thereby avoiding disordered aggregation and enlargement of particles, ensuring the uniformity of the titanium dioxide particles formed by reactivity, and further ensuring that the finally formed pearlescent pigment is bright and uniform in color and luster and has a flat and compact surface.

Description

Carbon-coated titanium pearlescent pigment and preparation method thereof

Technical Field

The invention relates to the technical field of pearlescent pigments, in particular to a carbon-coated titanium pearlescent pigment and a preparation method thereof.

Background

The pearlescent pigment material has the glittering effect of metal pigment, can generate the soft color of natural pearl, can generate multi-level reflection when being irradiated by sunlight, and the reflected light mutually acts to present soft and dazzling or colorful luster and color. Can be widely applied to the fields of coatings, plastics, rubber, printing ink, paper, textiles, cosmetics, ornaments, artware, leather, enamel, ceramics, packaging articles, printing decoration, building materials and the like.

The pearlescent pigments in the prior art have various colors such as blue, white, red, gray-black, and the like. Among them, a gray-black pearl pigment is generally obtained by directly mixing carbon black or the like with titanium dioxide and mica, but the pearl pigment obtained by this method is dull and uneven in color.

In view of this, the invention is particularly proposed.

Disclosure of Invention

The invention aims to provide a carbon-coated titanium pearlescent pigment and a preparation method thereof. The carbon-coated titanium pearlescent pigment and the preparation method thereof provided by the embodiment of the invention have bright and uniform color.

The invention is realized by the following steps:

in a first aspect, the present invention provides a method for preparing a carbon-coated titanium pearlescent pigment, comprising: adding a polymer monomer into a reaction system of the titanium oxychloride and the carbonate so as to enable the polymer monomer to be subjected to polymerization reaction.

In an alternative embodiment, the method comprises the following steps: mixing the carbonate salt and the polymer monomer to form a first mixture; then adding the solution containing the titanyl dichloride to the base material solution with the pH of 1-2, and simultaneously adding the first mixture to maintain the pH of the reaction system unchanged.

In an alternative embodiment, the preparation of the first mixture comprises: mixing the suspension containing the carbonate with the polymer monomer.

In an alternative embodiment, the carbonate is calcium carbonate.

In alternative embodiments, the polymer monomer is a monomer that is capable of undergoing polymerization under acidic conditions;

preferably, the polymer monomer is furfuryl alcohol.

In an alternative embodiment, the base material in the base material solution is any one of mica, glass, and alumina.

In an alternative embodiment, 5 to 15 grams of the polymer monomer, 0.5 to 0.7 mole of titanyl dichloride, and 0.5 to 0.7 mole of carbonate are added per 100 grams of substrate.

In an alternative embodiment, after the reaction of adding the polymer monomer is finished, the reaction system is filtered, washed, dried and calcined.

In an alternative embodiment, the temperature for drying is 100-150 ℃ and the temperature for calcining is 500-800 ℃.

In a second aspect, the present invention provides a carbon-coated titanium pearlescent pigment prepared by the method of preparing a carbon-coated titanium pearlescent pigment according to any one of the preceding embodiments.

The invention has the following beneficial effects: according to the embodiment of the invention, the polymer monomer is added into the reaction system in which the titanium dioxide is formed by the reaction of the titanium oxychloride and the carbonate, so that the polymer monomer is also subjected to polymerization reaction to form the polymer when the titanium oxychloride and the carbonate are reacted, and then the polymer can coat the formed titanium dioxide, thereby avoiding disordered aggregation and enlargement of particles, ensuring the uniformity of the titanium dioxide particles formed by reactivity, and further ensuring that the finally formed pearlescent pigment is bright and uniform in color and smooth and compact in surface.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained according to the drawings without inventive efforts.

FIG. 1 is an SEM image of a carbon-coated titanium pearlescent pigment provided in example 1 of the present invention;

FIG. 2 is a powder comparison of example 1 and comparative example pigments provided by the present invention;

FIG. 3 is a comparison of the pigments of example 1 and comparative example provided by the present invention in a PU resin;

FIG. 4 is a diagram showing the spraying effect of the carbon-coated titanium pearlescent pigment of example 1 provided by the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. The examples, in which specific conditions are not specified, were conducted under conventional conditions or conditions recommended by the manufacturer. The reagents or instruments used are not indicated by the manufacturer, and are all conventional products available commercially.

The embodiment of the invention provides a preparation method of a carbon-coated titanium pearlescent pigment, which comprises the following steps: adding a polymer monomer into a reaction system of the titanium oxychloride and the carbonate so as to enable the polymer monomer to be subjected to polymerization reaction. First, in the embodiment of the present invention, titanium oxychloride and carbonate are utilized to perform a neutralization reaction to form nano titanium dioxide particles, but the formed titanium dioxide particles have small particle size and are easy to agglomerate and disorder, so that the titanium dioxide particles on the base material are unevenly distributed and are not dense, and the color of the whole pearlescent pigment is dull and uneven. And the polymer monomer is added into the reaction system of the titanium oxychloride and the carbonate, so that the polymer monomer and the polymer monomer can be subjected to polymerization reaction to form a polymer during the neutralization reaction of the titanium oxychloride and the carbonate, and the formed polymer can coat the formed titanium dioxide, thereby avoiding disordered aggregation and enlargement of particles, ensuring the uniformity of the titanium dioxide particles formed by hydrolysis, and further improving the brightness and uniformity of the color of the pearlescent pigment.

The method comprises the following specific operation steps: mixing the carbonate salt and the polymer monomer to form a first mixture; then, the solution containing the titanyl dichloride is dripped into the base material solution with the pH of 1-2, and simultaneously, the first mixture is added to maintain the pH of the reaction system unchanged. The first mixture added in the embodiment of the present invention contains carbonate, which can perform a neutralization reaction with the titanyl dichloride to form titanium dioxide particles, and at the same time, the carbonate neutralizes the acidity of the titanyl dichloride, so that the acidity of the reaction system is not changed, and then the polymer monomer can perform a polymerization reaction to form a polymer and coat the titanium dioxide particles.

The carbonate used is calcium carbonate, but it is understood that calcium carbonate is merely exemplary of embodiments of the present invention, and other carbonates that can react with titanyl dichloride to form titanium dioxide are within the scope of embodiments of the present invention.

The polymer monomer is a monomer capable of undergoing a polymerization reaction under an acidic condition; for example, the polymer monomer is furfuryl alcohol. Furfuryl alcohol is merely exemplary of an embodiment of the present invention and other polymer monomers that can be polymerized to form a polymer under acidic conditions at a pH of 1 to 2 and can coat titanium dioxide are within the scope of embodiments of the present invention.

The base material in the base material solution is any one of mica, glass and alumina.

Further, 5 to 15 g of the polymer monomer, 0.5 to 0.7mol of titanyl dichloride and 0.5 to 0.7mol of carbonate are added per 100g of the substrate. For example, 5 g polymer monomer, 6 g polymer monomer, 7 g polymer monomer, 8 g polymer monomer, 9 g polymer monomer, 10 g polymer monomer, 11 g polymer monomer, 12 g polymer monomer, 13 g polymer monomer, 14 g polymer monomer, 15 g polymer monomer, and any value between 5 and 15 g polymer monomer is added for every 100g substrate; 0.5mol to 0.7mol of any of 0.5mol, 0.6mol, and 0.7mol of titanium oxychloride is added to 100g of the substrate, and 0.5mol to 0.7mol of any of 0.5mol to 0.7mol of carbonate is added to 100g of the substrate. The proportion is further favorable for the formation of titanium dioxide and polymer, and the polymer is favorable for coating the titanium dioxide.

Further, the preparing of the first mixture comprises: mixing the suspension containing the carbonate with the polymer monomer.

Further, after the reaction of adding the polymer monomer is finished, filtering, washing, drying and calcining the reaction system. Wherein the drying temperature is any value between 100-150 ℃, such as 100 ℃, 110 ℃, 120 ℃, 125 ℃, 130 ℃, 140 ℃, 145 ℃ and 150 ℃, and the free water on the pearlescent pigment can be effectively removed at the temperature. The calcination temperature is 500-800 ℃, for example, 500 ℃, 550 ℃, 600 ℃, 620 ℃, 650 ℃, 700 ℃, 770 ℃ and 800 ℃, etc., and at this temperature, not only can effectively remove the bound water of the pearlescent pigment, but also can carbonize the polymer.

The embodiment of the invention also provides a carbon-coated titanium pearlescent pigment, which is prepared by the preparation method of the carbon-coated titanium pearlescent pigment.

The features and properties of the present invention are described in further detail below with reference to examples.

Example 1

The embodiment provides a preparation method of a carbon-coated titanium pearlescent pigment, which comprises the following steps:

0.6mol of calcium carbonate was mixed with water to form a 30% calcium carbonate suspension by mass and then combined with 15 g of furfuryl alcohol to form a first mixture.

0.6mol of titanyl dichloride and water were mixed to form a 2M solution containing titanyl dichloride. 100g of mica is added into a reactor, water is added to 900 ml, the pH of the system is adjusted to 1, then 300 ml of the solution containing the titanium oxychloride is dripped, and the first mixture is dripped while the solution containing the titanium oxychloride is dripped, so that the pH of the system is kept unchanged.

After the reaction was completed, the reaction mixture was filtered, washed with water 2 times, dried at 100 ℃ for 1 hour, and then calcined at 500 ℃ for 30 minutes.

This example provides a carbon-coated titanium pearlescent pigment, which is prepared by the method, and the color of the pigment is gray-black.

SEM detection is carried out on the carbon-coated titanium pearlescent pigment, and the detection result is shown in figure 1.

Example 2

0.7mol of calcium carbonate was mixed with water to form a 30% calcium carbonate suspension by mass and then combined with 10 g of furfuryl alcohol to form a first mixture.

Mixing titanyl dichloride and water to form a solution containing titanyl dichloride. Adding 100g of mica into a reactor, adding water to 900 ml, adjusting the pH of the system to 1.5, then dropwise adding the solution containing the titanium oxychloride, dropwise adding the first mixture while dropwise adding the solution containing the titanium oxychloride, and keeping the pH of the system unchanged, wherein 0.7mol of titanium oxychloride is correspondingly added to 100g of mica.

After the reaction was completed, the reaction mixture was filtered, washed 3 times with water, dried at 150 ℃ for 1.5 hours, and then calcined at 800 ℃ for 30 minutes.

Example 3

0.5mol calcium carbonate was mixed with water to form a 30% calcium carbonate suspension by mass and then combined with 5 g furfuryl alcohol to form a first mixture.

Mixing titanyl dichloride and water to form a solution containing titanyl dichloride. Adding 100g of mica into a reactor, adding water to 900 ml, adjusting the pH of the system to 2, then dropwise adding the solution containing the titanium oxychloride, dropwise adding the first mixture while dropwise adding the solution containing the titanium oxychloride, and keeping the pH of the system unchanged, wherein 100g of mica is added with 0.5mol of titanium oxychloride correspondingly.

After the reaction was completed, the reaction mixture was filtered, washed with water 2 times, dried at 120 ℃ for 1 hour, and then calcined at 750 ℃ for 40 minutes.

Example 4

0.65mol of calcium carbonate was mixed with water to form a 30% calcium carbonate suspension by mass and then combined with 12 g of furfuryl alcohol to form a first mixture.

Mixing titanyl dichloride and water to form a solution containing titanyl dichloride. Adding 100g of mica into a reactor, adding water to 900 ml, adjusting the pH of the system to 1, then dropwise adding the solution containing the titanium oxychloride, dropwise adding the first mixture while dropwise adding the solution containing the titanium oxychloride, and keeping the pH of the system unchanged, wherein the mica with 100g correspondingly adds 0.65mol of the titanium oxychloride.

After the reaction was completed, the reaction mixture was filtered, washed 3 times with water, and then dried at 145 ℃ for 1.5 hours, followed by calcination at 700 ℃ for 45 minutes.

Example 5

0.55mol calcium carbonate was mixed with water to form a 30% calcium carbonate suspension by mass and then combined with 8 g furfuryl alcohol to form a first mixture.

Mixing titanyl dichloride and water to form a solution containing titanyl dichloride. Adding 100g of mica into a reactor, adding water to 900 ml, adjusting the pH of the system to 2, then dropwise adding the solution containing the titanium oxychloride, dropwise adding the first mixture while dropwise adding the solution containing the titanium oxychloride, and keeping the pH of the system unchanged, wherein 100g of mica is added with 0.6mol of titanium oxychloride correspondingly.

After the reaction is finished, the mixture is filtered, washed by water for 2 times, dried for 1 hour at the temperature of 100 ℃, and then calcined for half an hour at the temperature of 600 ℃ in a nitrogen atmosphere.

Comparative example

Adding 100g of natural mica silver white pearlescent pigment (the particle size is 10-60 mu m) and 1000ml of deionized water into a reactor with mechanical stirring in sequence, stirring, reducing the pH value to 5.2 by using dilute hydrochloric acid, adding a solution of carbon black color paste, stirring for 15 minutes, dropwise adding 20% of aluminum trichloride solution, dropwise adding 30% of liquid alkali solution, keeping the pH value unchanged until the target addition amount is reached, continuing stirring for half an hour, filtering, washing, and drying at 110 ℃ to obtain the pearlescent pigment. The target addition amount of the comparative example and the target addition amount (reduced char content) of example 1 were consistent.

Performance evaluation of the samples:

the quality of the sample is evaluated by a common method of coating a scratch card or a spray plate. Adding a certain pearlescent pigment into resin or paint, stirring uniformly, coating or spraying a plate, and testing the color and the smoothness by using an X-Rite MA68 color difference instrument. As shown in the following table:

alice test color data

From the above results, it can be seen that example 1, which is a sample of the present invention, has significantly improved color saturation (value of h ° represents color), color saturation (value of C), and brightness (value of L) similar to those of the comparative example. In particular, the color saturation (C value) is significantly improved.

The pigment powders of example 1 and comparative example were photographed and compared, and referring to fig. 2, it can be seen that the pigment of example 1 has darker color and finer powder quality.

The pigments of example 1 and comparative example are sprayed and added to PU resin and photographed for comparison, referring to FIG. 3, the left side of FIG. 3 is the effect diagram of example 1, the right side is the effect diagram of comparative example, it can be seen that the material formed after the pigment of example 1 is mixed with PU resin is smoother.

The picture after spraying the pigment of example 1 is shown in fig. 4, and it can be seen that the surface is bright and uniform in color.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A preparation method of carbon-coated titanium pearlescent pigment is characterized by comprising the following steps: adding a polymer monomer into a reaction system of titanium oxychloride and carbonate to enable the polymer monomer to generate a polymerization reaction, and after the reaction of adding the polymer monomer is finished, filtering, washing, drying and calcining the reaction system;

wherein the polymerization reaction comprises: mixing the carbonate salt and the polymer monomer to form a first mixture; then adding the solution containing the titanyl dichloride into a base material solution with the pH value of 1-2, and simultaneously adding the first mixture to maintain the pH value of the reaction system unchanged;

the base material in the base material solution is any one of mica, glass and alumina, 5-15 g of polymer monomer, 0.5-0.7 mol of titanium oxychloride and 0.5-0.7 mol of carbonate are correspondingly added to every 100g of base material, and the polymer monomer is furfuryl alcohol.

2. The method of claim 1, wherein the preparing the first mixture comprises: mixing the suspension containing the carbonate with the polymer monomer.

3. The method according to claim 1 or 2, wherein the carbonate is calcium carbonate.

4. The method as claimed in claim 1, wherein the drying temperature is 100-150 ℃ and the calcining temperature is 500-800 ℃.

5. A carbon-coated titanium pearl pigment, which is produced by the method for producing a carbon-coated titanium pearl pigment according to any one of claims 1 to 4.