CN103333528A - Preparation method of pearlescent pigment having fluorescent effect - Google Patents

Abstract

The invention relates to a preparation method of a pearlescent pigment with fluorescent effect. The method first uses mica to pre-prepare the mica titanium pearlescent pigment, and the process is as follows: the mica is put into water to form a suspension liquid 1, and the reaction mother liquid 1 is obtained after stirring; the titanium tetrachloride solution is added dropwise to the reaction mother liquid 1, Adjust the pH value of the system, stir to obtain the product suspension 2; implement solid-liquid separation, and dry to obtain the mica titanium pearlescent pigment raw material. Reuse the prepared mica titanium pearlescent pigment into water to form a reactant suspension 3 to obtain a reaction mother liquor; add the mixed solution of calcium liquid and transition metal M water-soluble salt to the reaction mother liquor dropwise, and keep stirring to obtain a product suspension Solution 3: implement solid-liquid separation, fully roast after drying to obtain fluorescent effect pearlescent pigments. The method of the invention is simple to prepare, the cost of raw materials is low, and it is easy to popularize and apply.

Description

A kind of preparation method of pearlescent pigment with fluorescent effect

technical field

The invention relates to a preparation method of pearlescent pigment, in particular to a preparation method of pearlescent pigment with fluorescent effect.

Background technique

Composite double-layer mica-titanium pearlescent pigment first coats titanium dioxide on the surface of mica, which interferes to produce a pearlescent effect and has a relatively good pearlescent luster. The surface of the mica titanium pearlescent pigment is coated with other metal oxides or non-metallic substances with special properties, so that the pearlescent pigment has both good pearlescent properties and some special properties.

Red fluorescent materials include several types of materials such as sulfides, sulfur oxides, oxides and titanates. Alkaline earth metal titanates doped with rare earth ions and praseodymium is a kind of red fluorescent material with stable chemical properties and high color purity. Luminescent material. Praseodymium ion-doped calcium titanate is an ideal fluorescent pigment, its CIE chromaticity coordinates x=0.680, y=0.311, its emission spectrum is pure, very close to the ideal red light, and has a great application prospect.

There are also many methods for preparing praseodymium-doped calcium titanate fluorescent materials. At present, there are high-temperature solid-phase methods, combustion methods, and sol-gel methods that are known at home and abroad. As a commonly used method for synthesizing luminescent materials, the high-temperature solid-phase method has its unique advantages. The production process is relatively simple, and the process is mature and constantly improving. Chinese patent CN 101544886 B (praseodymium-doped calcium titanate luminescent powder and its preparation) combines spray pyrolysis method and high-temperature solid-phase method, dissolves a certain amount of CaCO ₃ and Pr ₆ O ₁₁ solids in dilute nitric acid, heats and stirs After the pH value of the solution reaches 2~3, heat the solution until it melts, add n-butyl titanate, water-ethanol solution, citric acid and polyethylene glycol after cooling, and stir to obtain the precursor , spray-dried and calcined at high temperature to obtain praseodymium-doped calcium titanate phosphor. Chinese patent CN 101899298 A (a method for rapidly synthesizing luminescent materials), according to the metering ratio, calcium nitrate, zinc nitrate, butyl titanate, sodium carbonate, citric acid and polyethylene glycol were dissolved in deionized water, and weighed Praseodymium oxide is dissolved in concentrated nitric acid, and after mixing, it is burned in a muffle furnace until there is no flame, and after treatment, the praseodymium-doped calcium titanate fluorescent material is obtained.

Wuhan University of Technology has done related research on the preparation of fluorescent mica powder doped with strontium aluminate, using co-precipitation and combustion methods to prepare europium and dysprosium doped aluminate fluorescent materials. The co-precipitation method was used to prepare fluorescent mica powder doped with strontium aluminate, and the influence of factors such as the choice of precipitant, dosage, reaction temperature, dosage of activator and auxiliary agent, and reaction pH on the performance of fluorescent powder were studied (Gao Huimin, Mica Pigment Preparation and Mechanism Research [D]. Wuhan: Wuhan University of Technology, 2010.). However, the prepared fluorescent mica powder needs a relatively high calcination temperature to have a relatively excellent fluorescence intensity, which makes the pearlescent effect poor.

There are few reports on the study of pearlescent pigments with fluorescent effects. It is also a development need to integrate the pearlescent properties of pearlescent pigments and the fluorescent effects of fluorescent materials, which can bring better economic benefits, anti-counterfeiting performance, and decorative effects.

Contents of the invention

The purpose of the present invention is to provide a preparation method of pearlescent pigment with fluorescent effect.

In order to achieve the above object, the technical scheme that the present invention takes is:

1. Pre-preparation of mica titanium pearlescent pigment

a. Put 50 g of mica into 500 mL of water to form a suspension, and adjust the pH of the suspension to 2.0 with 6.0 mol/L hydrochloric acid, and stir evenly to obtain the reaction mother liquid 1;

b. Add 100mL of titanium tetrachloride solution dropwise to reaction mother liquor 1 under the condition of 78°C water bath, adjust the pH value of the system to 2.0 by 4.0mol/L sodium hydroxide, and keep stirring at the same time to promote the interaction between the components in the system. After the liquid addition was completed, the stirring was continued for 30 min to obtain the product suspension 1.

c. The solid-liquid separation is carried out on the product suspension 1, and the obtained solid matter is dried, which is the raw material of the secondary coated mica titanium pearlescent pigment.

Described titanium tetrachloride solution, solubility is 2mol/L;

The dripping is carried out at 0.3mL/min;

Described stirring, its speed is 400r/min.

2. Preparation of pearlescent pigments

a. According to the ratio of 1 gram of mica titanium pearlescent pigment to 10 milliliters of water, put the mica titanium pearlescent pigment into water and stir to form a reactant suspension 2, adjust the pH value of the suspension to 10~11 with sodium hydroxide solution, and stir evenly. Obtain reaction mother liquor 2;

b. Under the temperature condition of 70~80℃, the mixed solution of calcium liquid and water-soluble salt of transition metal M is added to the above reaction mother liquor at a rate of 0.040~0.12mL/min by metering control equipment, and at the same time, 400 r/min The speed of min keeps constant mechanical stirring to promote the uniform reaction among the components in the system;

c. After the dropwise addition of the mixed solution is completed, continue to stir for 30 min to obtain the product suspension 3;

d. implementing solid-liquid separation to the product suspension 3, and drying the gained solid matter;

e. At 600~1000°C, fully roast the dried solid matter and cool to obtain fluorescent effect pearlescent pigments.

Described calcium liquid refers to calcium nitrate solution or calcium chloride solution;

M in the transition metal M water-soluble salt refers to praseodymium, europium, zinc or cerium;

The water-soluble salt of transition metal M refers to the nitrate of praseodymium, europium, zinc or cerium, or the chloride of praseodymium, europium, zinc or cerium, or the water-soluble salt of two kinds of transition metal M in any ratio. mixture;

The mixed solution, wherein the total molar ratio of the transition metal M praseodymium, europium, zinc or cerium to the calcium molar ratio in the calcium solution is 1 to 6:1000;

The mica titanium pearlescent pigment is a silver-white pearlescent pigment made by the method described in technical scheme 1 through the present invention. The self-made mica titanium pearlescent pigment has different hues according to different coverage ratios, and with the increase of coverage ratios, it presents silvery white, yellow, red, blue and green shades in sequence. The host material mica in the self-made process can be natural or synthetic. The mica with a sheet diameter of 10-60 μm and an aspect-thickness ratio of 45 or more is preferred. Synthetic fluorophlogopite with this sheet diameter and thickness is even better;

The hydrochloric acid concentration of the present invention is 6.0 mol/L, and the sodium hydroxide concentration is 2.0-4.0 mol/L.

The method of the invention is simple to prepare, the cost of raw materials is low, and it is easy to popularize and apply.

Description of drawings

Fig. 1 is the excitation spectrum and emission spectrum of the pearlescent pigment that the present invention obtains;

Fig. 2 is the XRD spectrogram of the pearlescent pigment that the present invention obtains;

Fig. 3 is the photo of the pearlescent pigment that the present invention obtains under natural light;

Figure 4 is a series of SEM images of pearlescent pigments with fluorescent effect prepared at different pH values, reaction temperatures, liquid addition rates and calcination temperatures.

Detailed ways

In order to better understand the present invention, the present invention will be further described in conjunction with the accompanying drawings and embodiments.

Fig. 1 is the excitation spectrum and emission spectrum diagram of the pearlescent pigment with fluorescent effect obtained after the pH value is 10.5, the reaction temperature is 75°C, the liquid addition rate is 0.080mL/min, and it is roasted at 800°C.

In Fig. 2, a, b, and c are the XRD spectra of mica titanium pearlescent pigment, uncalcined fluorescent effect pearlescent pigment and 800°C roasted fluorescent effect pearlescent pigment, respectively.

Figure 3 is a photo of fluorescent effect pearlescent pigments under natural light.

In Figure 4, a is the SEM image of the pearlescent pigment with fluorescent effect after the pH value is 11.0, the reaction temperature is 70°C, the liquid addition rate is 0.12mL/min, and it is roasted at 1000°C.

In Figure 4, b is the SEM image of the fluorescent effect pearlescent pigment after the pH value is 10.0, the reaction temperature is 80°C, the liquid addition rate is 0.080mL/min, and it is roasted at 600°C.

In Fig. 4, c is the SEM image of the fluorescent effect pearlescent pigment after the pH value is 10.5, the reaction temperature is 75°C, the liquid addition rate is 0.080mL/min, and it is roasted at 800°C.

In Figure 4, d is the SEM image of the fluorescent effect pearlescent pigment after the pH value is 10.5, the reaction temperature is 75°C, the liquid addition rate is 0.040mL/min, and it is roasted at 800°C.

Example 1

1. Pre-preparation of mica titanium pearlescent pigment

a. Put 50g of mica into 500mL of water to form a suspension 1, and adjust the pH of the suspension to 2.0 with 6.0mol/L hydrochloric acid, and stir well to obtain the reaction mother solution 1.

b. Add 100mL of 2mol/L titanium tetrachloride solution to reaction mother liquor 1 under the condition of 78℃ water bath at 0.3mL/min, adjust the pH value of the system to 2.0 by 4.0mol/L sodium hydroxide, and at the same time, use 400r/L Stir continuously for 1 min to promote the uniform reaction among the components in the system. After the liquid addition is completed, continue stirring for 30 min to obtain the product suspension 2.

c. The solid-liquid separation is carried out on the product suspension 2, and the obtained solid matter is dried, which is the secondary coated mica titanium pearlescent pigment raw material.

2. Preparation of pearlescent pigments

a. Put 40g of pre-prepared mica titanium pearlescent pigment into 400mL water and stir to form reactant suspension 2, and adjust the pH value of suspension 2 to 11.0 with 3.0mol/L sodium hydroxide, and stir evenly to obtain reaction mother liquor 2 .

b. Mix 0.008mol/L praseodymium nitrate and 2mol/L calcium chloride solution to form a 20mL mixed solution, and add the mixed solution dropwise to the reaction mother liquor under the condition of 70°C water bath at a rate of 0.12mL/min, pass through 3.0 mol/L sodium hydroxide to adjust the pH value of the system to 11.0, and continuously stir at 400r/min to promote the uniform reaction between the components in the system. Turbid liquid 3.

c. The product suspension 3 was subjected to solid-liquid separation, and the obtained solid matter was dried.

d. Calcining the solid matter at 1000°C and cooling to obtain the pearlescent pigment with fluorescent effect described in the present invention. The SEM image of the pearlescent pigment prepared in this embodiment is shown in a in FIG. 4 .

Example 2

1. Pre-preparation of mica titanium pearlescent pigment

The pre-preparation method is the same as in Example 1.

2. Preparation of pearlescent pigments

a. Put 40g of mica titanium pearlescent pigment into 400mL water and stir to form reactant suspension 2, and adjust the pH value of suspension 2 to 10.0 with 2.0mol/L sodium hydroxide, and stir evenly to obtain reaction mother liquor 2.

b. Mix 0.012mol/L europium nitrate and 2mol/L calcium nitrate solution to form a 20mL mixed solution, and add the mixed solution dropwise at a rate of 0.080mL/min to the reaction mother solution 2 under the condition of 80°C water bath, pass 2.0mol/L sodium hydroxide is adjusted to adjust the pH value of the system to 10, and at the same time, it is continuously stirred at 400r/min to promote the uniform reaction between the components in the system. After the addition of the mixed solution is completed, continue to stir for 30 minutes to obtain Product suspension 3.

c. The product suspension 3 was subjected to solid-liquid separation, and the obtained solid matter was dried.

d. Calcining the solid matter at 600°C and cooling to obtain the pearlescent pigment of the present invention. The SEM image of the pearlescent pigment prepared in this embodiment is shown in b in FIG. 4 .

Example 3

1. Pre-preparation of mica titanium pearlescent pigment

The pre-preparation method is the same as in Example 1.

2. Preparation of pearlescent pigments

a. Put 40g of mica titanium pearlescent pigment into 400mL water and stir to form reactant suspension 2, and adjust the pH value of suspension 2 to 10.5 with 2.0mol/L sodium hydroxide, and stir evenly to obtain reaction mother liquor 2.

b. Mix 0.001mol/L praseodymium chloride, 0.001mol/L cerium nitrate and 2mol/L calcium chloride solution to form a 20mL mixed solution, and add the mixed solution dropwise to 75°C at a rate of 0.080mL/min In the reaction mother liquor under water bath conditions, the pH value of the system was adjusted to 10.5 by 2.0mol/L sodium hydroxide, and at the same time, it was continuously stirred at 400r/min to promote the uniform reaction between the components in the system, and the mixed solution was added dropwise. After that, the stirring was continued for 30 min to obtain the product suspension 3.

c. The product suspension 3 was subjected to solid-liquid separation, and the obtained solid matter was dried.

d. Calcining the solid matter at 800°C and cooling to obtain the pearlescent pigment of the present invention. The SEM image of the pearlescent pigment prepared in this embodiment is shown in c in FIG. 4 .

Example 4

1. Pre-preparation of mica titanium pearlescent pigment

The pre-preparation method is the same as in Example 1.

2. Preparation of pearlescent pigments

a. Put 40g of mica titanium pearlescent pigment into 400mL water and stir to form reactant suspension 2, and adjust the pH value of suspension 2 to 10.5 with 2.0mol/L sodium hydroxide, and stir evenly to obtain reaction mother liquor 2.

b. Mix 0.002mol/L praseodymium nitrate, 0.002mol/L zinc chloride and 2mol/L calcium nitrate solution to form a 20mL mixed solution, and add the mixed solution dropwise to a 75°C water bath at a rate of 0.040mL/min In the reaction mother liquid 2 below, the pH value of the adjustment system was adjusted to 10.5 by 2.0mol/L sodium hydroxide, and at the same time, it was continuously stirred at 400r/min to promote the uniform reaction between the components in the system, and the mixed solution was added dropwise. After that, the stirring was continued for 30 min to obtain the product suspension 3.

c. The product suspension 3 was subjected to solid-liquid separation, and the obtained solid matter was dried.

d. Calcining the solid matter at 800°C and cooling to obtain the pearlescent pigment of the present invention. The SEM image of the pearlescent pigment prepared in this example is shown in d in FIG. 4 .

Claims (8)

1. a kind of preparation method of the pearlescent pigment with fluorescent effect, at first is to utilize mica to carry out pre-preparation to mica titanium pearlescent pigment, utilizes self-made mica titanium pearlescent pigment to prepare pearlescent pigment again, it is characterized in that: 1) Pre-preparation of mica titanium pearlescent pigment a. Put the mica into water to form a suspension, and adjust the pH value of the suspension to 2.0 with 6.0mol/L hydrochloric acid, and stir well to obtain the reaction mother liquor 1; b. Add 100mL of titanium tetrachloride solution dropwise to reaction mother liquor 1 under the condition of 78°C water bath, adjust the pH value of the system to 2.0 by 4.0mol/L sodium hydroxide, and keep stirring at the same time to promote the interaction between the components in the system. After the liquid addition is completed, continue to stir for 30 min to obtain the product suspension 1; c. Carrying out solid-liquid separation on the product suspension, and drying the obtained solid matter is the secondary coated mica titanium pearlescent pigment raw material; 2) Preparation of pearlescent pigments a. Put the mica titanium pearlescent pigment into water to form a reactant suspension 2, adjust the pH value of the suspension 2 to 10-11 with sodium hydroxide solution, stir evenly, and obtain the reaction mother liquor 2; b. Under the temperature condition of 70~80°C, add the mixed solution of calcium liquid and water-soluble salt of transition metal M into the reaction mother liquid 2 dropwise, while maintaining constant mechanical stirring; c. After the addition of the mixed solution is completed, continue to stir for 30 min to obtain the product suspension 3; d. implementing solid-liquid separation to the product suspension 3, and drying the gained solid matter; e. At 600~1000°C, fully roast the dried solid matter and cool to obtain fluorescent effect pearlescent pigments. 2. the preparation method of a kind of pearlescent pigment with fluorescent effect according to claim 1, is characterized in that described titanium tetrachloride solution, solubility is 2mol/L; Described dripping, is with 0.3mL Carry out under /min; Described mechanical stirring, stirring speed is 400r/min. 3. the preparation method of a kind of pearlescent pigment with fluorescent effect according to claim 1 is characterized in that described reactant suspension 1 is configured according to the ratio of 1 gram of mica titanium pearlescent pigment to 10 milliliters of water. 4. the preparation method of a kind of pearlescent pigment with fluorescent effect according to claim 1 is characterized in that described dropping, its rate is 0.040～0.12mL/min; Described mechanical stirring, stirring speed is 400 r/min. 5. The preparation method of a kind of pearlescent pigment with fluorescent effect according to claim 1, characterized in that said calcium solution refers to calcium nitrate solution or calcium chloride solution. 6. the preparation method of a kind of pearlescent pigment with fluorescent effect according to claim 1 is characterized in that the water-soluble salt of described transition metal M refers to the nitrate of praseodymium, europium, zinc or cerium, or praseodymium, Chloride of europium, zinc or cerium, or a mixed solution of two water-soluble salts of transition metal M in any proportion. 7. the preparation method of a kind of pearlescent pigment with fluorescent effect according to claim 8 is characterized in that the total molar weight of praseodymium, europium, zinc or cerium in the water-soluble salt of described transition metal M is the same as that in the calcium solution. The calcium molar ratio is 1-6:1000. 8. The preparation method of a pearlescent pigment with fluorescent effect according to claim 1, characterized in that the concentration of hydrochloric acid is 6.0 mol/L, and the concentration of sodium hydroxide is 2.0-4.0 mol/L.

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