Photochromic pearlescent pigment and preparation method thereof

Abstract

The invention provides a photochromic pearlescent pigment and a preparation method thereof. The pigment comprises 40-60 parts of a pearlescent pigment, 5-20 parts of photochromic powder, 15-25 parts of a metal oxide, 1-5 parts of a silane coupling agent, 0.5-2 parts of a dispersant and 20-40 parts of an adhesive. The water-based photochromic powder is prepared by dispersing a photochromic compound in a water-based carrier and carrying out multi-frequency ultrasonic treatment and the like; the oily substance is obtained by dissolving a photochromic compound and then adding polystyrene and other substances for reaction. The preparation method comprises a liquid phase deposition method and a dry adsorption method. The liquid phase deposition method comprises the following steps: pretreating pearlescent pigment to obtain pearlescent slurry, and sequentially adding a silane coupling agent, photosensitive color-changing powder and the like; according to the dry adsorption method, pearlescent pigment and the like are mixed, and then a silane coupling agent and the like are added. The photosensitive color-changing pearlescent pigment can be applied to cosmetics, coatings, printing ink or plastic products, has a good color-changing effect and stability, and can meet the requirements of different fields.

Description

Technical Field

[0001] The invention relates to the field of pearlescent pigment processing, and in particular to a photosensitive color-changing pearlescent pigment and a preparation method thereof. Background Art

[0002] In the field of modern materials science, the demand for pigments with special properties and visual effects is growing. Although traditional pearlescent pigments can provide a certain gloss and decorative effect, their performance is relatively single and cannot meet people's needs for dynamic changes in materials under different environmental conditions. With the advancement of science and technology and the improvement of people's requirements for material performance, photochromic materials have gradually attracted attention. This type of material can change color according to changes in external light, bringing unique visual experience and functionality to the product. However, existing photochromic materials still have some shortcomings in practical applications.

[0003] Most of the photochromic pigments on the market currently have problems such as insufficient color change effect, single color change, poor weather resistance and complex preparation process. The color change effect of some photochromic materials is not sensitive and durable enough, and performance degradation is prone to occur after multiple color change cycles. At the same time, its compatibility and stability with other ingredients need to be improved, which limits its application in a wider range of fields. In industries such as cosmetics, coatings, inks and plastic products, the demand for pigments that can combine beauty and functionality is becoming increasingly urgent. Existing pigments often cannot simultaneously meet the requirements of color change, stability, durability and good compatibility with various substrates in different environments.

[0004] Therefore, developing a new type of photosensitive color-changing pearlescent pigment to solve the problems existing in the prior art and improve its color-changing performance, stability and applicability has important practical significance and application value. Summary of the invention

[0005] In view of this, the present invention provides a photosensitive color-changing pearlescent pigment and a preparation method thereof to solve the above problems.

[0006] The technical solution of the present invention is achieved as follows: a photosensitive color-changing pearlescent pigment: comprising the following raw materials in parts by weight: 40-60 parts of pearlescent pigment, 5-20 parts of photosensitive color-changing powder, 15-25 parts of metal oxide, 1-5 parts of silane coupling agent, 0.5-2 parts of dispersant, and 20-40 parts of adhesive; the pearlescent pigment is mica flakes, the photosensitive color-changing powder is water-based photochromic powder or oil-based photochromic powder, the metal oxide is titanium dioxide, iron oxide, zinc oxide or aluminum oxide, and the adhesive is acrylic resin or polyurethane resin.

[0007] Furthermore, the preparation method of the water-based photochromic powder is to disperse the photochromic compound in an aqueous carrier with a solid-liquid ratio of g / mL of 1:0.5-1 to form a uniform solution, wherein the aqueous carrier is deionized water or an ethanol solution with a mass concentration of 60-80%, add 0.3-1% by volume of ultraviolet absorber BP-4 at a stirring rate of 400-600rpm, control the temperature at 25-60°C, the pressure at 0.6-1.5MPa, and the pH at 6-8 to carry out a multi-frequency ultrasonic combined mixing reaction for 3-5h, purify, and dry to form a water-based photochromic powder.

[0008] Furthermore, the multi-frequency ultrasound parameters are: any one of frequencies of 10, 15, and 20 kHz, power of 300-600 W, time of 5-20 min, and interval of 10-15 min.

[0009] Furthermore, the oily photochromic powder is prepared by dissolving a photochromic compound in xylene with a mass-to-volume ratio of 8-12:50 in g / mL, and then adding 40-60% of polystyrene by mass of the compound to the above solution at 40-60°C, and adding 20-30% of sodium dodecylbenzene sulfonate by mass of the compound, emulsifying the mixture in a high shear emulsifier at a speed of 10000-20000rpm for 20-40min to form a stable emulsion, and then adding 10-15% of benzoyl peroxide by mass of the compound, maintaining the temperature at 70-80°C, reacting for 2-4h, and purifying and dispersing the mixture to obtain the oily photochromic powder.

[0010] Furthermore, the photochromic compound is any one or a combination of spiropyran, spirooxazine, naphthopyran, fulgide, and diarylethene compounds.

[0011] Furthermore, the silane coupling agent is selected from kh-570 silane coupling agent, kh-560 silane coupling agent or kh-550 silane coupling agent.

[0012] Furthermore, the dispersant includes but is not limited to sodium stearate, sodium dodecyl sulfate, sodium dodecylbenzene sulfonate, polyvinyl alcohol hydroxypropyl methylcellulose, nonylphenol polyoxyethylene ether, polyoxyethylene alkylamine, and fatty acid polyoxyethylene ester.

[0013] Furthermore, a method for preparing a photosensitive color-changing pearlescent pigment is prepared by a liquid phase deposition method, comprising the following steps:

[0014] a. Pretreatment: put the pearlescent pigment into a reactor with deionized water, the solid-liquid ratio g / mL is 1:6-20, stir the system at a speed of 200-400rpm, stir for 10-20min, and obtain a pearlescent slurry;

[0015] b. The pearlescent slurry is heated to 60-90°C, the reaction pressure is 1-5kPa, and stirred at a rate of 500-1000rpm for 15-30min;

[0016] c. Continue to add silane coupling agent to the above pearlescent slurry, stir evenly, then slowly add water-sensitive photochromic powder and metal oxide, and continue to react for 1-4h;

[0017] d. Add dispersant and binder to the above system in sequence and stir for 1-2h;

[0018] e. After washing, filtering and drying at 50-150°C, a photosensitive color-changing pearlescent pigment is obtained.

[0019] Further, the preparation is carried out by a dry adsorption method, comprising the following steps:

[0020] a. Put the pearlescent pigment, oily photochromic powder and metal oxide into a spiral powder mixer and mix for 0.5-2h;

[0021] b. Add silane coupling agent and continue mixing for 20-40 minutes to allow the silane coupling agent to be evenly dispersed and act on the surface of the mixture;

[0022] c. Add dispersant and binder to the above system in sequence and stir for 1-2h;

[0023] d. Place the mixed materials in an oven and dry them at 50-100°C for 2-4 hours to solidify the adhesive and firmly combine the components to obtain a photosensitive color-changing pearlescent pigment.

[0024] Furthermore, the photochromic pearlescent pigment is applied to cosmetics, coatings, inks or plastic products.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] The photochromic pearlescent pigment of the present invention realizes the synergistic effect between the photochromic powder and the pearlescent pigment through precise raw material ratio and preparation process. The coated photochromic pearlescent pigment has the pearlescent pigment as its original color. The various photochromic pearlescent pigments based on the principle of photochromic color change when exposed to light provide rich color changes and excellent gloss effect. The selected metal oxides such as titanium dioxide, iron oxide, zinc oxide or aluminum oxide enhance the weather resistance and chemical resistance of the pigment, so that the pigment can remain stable under various environmental conditions. By using silane coupling agents and various dispersants, the pearlescent pigment of the present invention exhibits good dispersibility in different media, avoids agglomeration, and ensures uniform distribution of the pigment. The photochromic pearlescent pigment includes a preparation method of water-based and oil-based photochromic powder, so that it can adapt to various application environments such as water-based and oil-based cosmetics, coatings, inks or plastic products.

[0027] The present invention proposes a photochromic pearlescent pigment and a preparation method thereof, aiming to achieve rapid, obvious and stable color change of the pigment under lighting conditions through scientific proportioning and advanced technology, while retaining the unique luster of the pearlescent pigment. The pigment not only overcomes the shortcomings of traditional photochromic pigments, but also enriches the types and application range of pigments, providing a new material choice for related industries. DETAILED DESCRIPTION

[0028] In order to better understand the technical content of the present invention, specific embodiments are provided below to further illustrate the present invention.

[0029] Unless otherwise specified, the experimental methods used in the embodiments of the present invention are all conventional methods.

[0030] Unless otherwise specified, the materials, reagents, etc. used in the embodiments of the present invention can be obtained from commercial sources.

[0031] Example 1

[0032] A photochromic pearlescent pigment: comprising the following raw materials in parts by weight: 50 parts of pearlescent pigment, 12 parts of photochromic powder, 20 parts of titanium dioxide, 3 parts of kh-570 silane coupling agent, 1.2 parts of sodium stearate, and 30 parts of acrylic resin; the pearlescent pigment is mica flakes, the photochromic powder is water-sensitive photochromic powder,

[0033] The preparation method of the water-based photochromic powder is as follows: spiropyran is dispersed in deionized water with a solid-liquid ratio of 1:0.75 g / mL to form a uniform solution, 0.65% by volume of ultraviolet absorber BP-4 is added at a stirring rate of 500 rpm, the temperature is controlled at 42.5° C., the pressure is 1.05 MPa, and the pH value is 7, a multi-frequency ultrasonic combined mixing reaction is performed for 4 hours, the multi-frequency ultrasonic frequency cycle is selected to be 10, 15, and 20 kHz, the power is 450 W, the time is 12.5 minutes, the interval is 12.5 minutes, purification, drying, and forming the water-based photochromic powder;

[0034] The above-mentioned photochromic pearlescent pigment is prepared by liquid phase deposition method:

[0035] a. Pretreatment: Put the pearlescent pigment into a reactor with deionized water at a solid-liquid ratio of 1:13 g / mL, stir the system at a speed of 300 rpm for 15 minutes to obtain a pearlescent slurry.

[0036] b. The pearlescent slurry was heated to 75°C, the reaction pressure was 3 kPa, and stirred at a rate of 750 rpm for 22.5 min.

[0037] c. Continue to add KH-570 silane coupling agent to the above pearlescent slurry, stir evenly, then slowly add water-based photochromic powder and titanium dioxide, and continue the reaction for 2.5 hours.

[0038] d. Add sodium stearate and acrylic resin to the above system in sequence and stir for 1.5 hours.

[0039] e. After washing, filtering and drying at 100°C, a photosensitive color-changing pearlescent pigment is obtained.

[0040] Example 2

[0041] A photochromic pearlescent pigment: comprising the following raw materials in parts by weight: 50 parts of pearlescent pigment, 12 parts of photochromic powder, 20 parts of iron oxide, 3 parts of KH-560 silane coupling agent, 1.2 parts of sodium dodecyl sulfate, and 30 parts of polyurethane resin; the pearlescent pigment is mica flakes, the photochromic powder is oily photochromic powder,

[0042] The oily photochromic powder is prepared by dissolving a spirooxazine dye in xylene at a mass-to-volume ratio of 10:50 g / mL, then adding 50% polystyrene by mass of the compound to the solution at 50°C, and adding 25% sodium dodecylbenzene sulfonate by mass of the compound, emulsifying the mixture at a speed of 15000 rpm for 30 minutes in a high shear emulsifier to form a stable emulsion, then adding 12.5% ​​benzoyl peroxide by mass of the compound, maintaining the temperature at 75°C, reacting for 3 hours, purifying, and dispersing the mixture to obtain the oily photochromic powder;

[0043] The above-mentioned photochromic pearlescent pigment is prepared by a dry adsorption method, which comprises the following steps:

[0044] a. Put the pearlescent pigment, oily photochromic powder and iron oxide into a spiral powder mixer and mix for 1.25 hours;

[0045] b. Add kh-560 silane coupling agent and continue mixing for 30 minutes to make the kh-560 silane coupling agent evenly dispersed and act on the surface of the mixture;

[0046] c. Add sodium dodecyl sulfate and polyurethane resin to the above system in sequence and stir for 1.5h;

[0047] d. Place the mixed materials in an oven and dry them at 75°C for 3 hours to solidify the adhesive and firmly combine the components to obtain a photosensitive color-changing pearlescent pigment.

[0048] Comparative Example 1

[0049] The difference between this comparative example and Example 1 is that the photochromic powder is not modified by an aqueous carrier, and the photochromic powder is spiropyran.

[0050] Comparative Example 2

[0051] The difference between this comparative example and Example 2 is that the photochromic powder is not emulsified into an oily photochromic powder, and the photochromic powder is a spirooxazine dye.

[0052] Test Example 1-Color Change Performance

[0053] The photochromic pearlescent pigments prepared in Examples 1 and 2 and Comparative Examples 1 and 2 were tested for their color changing properties, including color changing speed, color changing amplitude, and recovery speed. The test results are shown in Table 1 below:

[0054]

[0055] Test Example 2-Stability

[0056] The light-sensitive color-changing pearlescent pigments prepared in the above-mentioned Examples 1-2 and Comparative Examples 1-2 were tested for their light resistance, heat resistance, and water resistance;

[0057] 1. Test conditions:

[0058] (1) Light resistance: Xenon lamp irradiation for 600 hours, light intensity 550W / m 2 , temperature 45℃, humidity 55%.

[0059] (2) Heat resistance: Placed in an oven at 150°C for 60 hours.

[0060] (3) Water resistance: Soak in 180℃ water for 100 hours.

[0061] 2. Test results:

[0062]

[0063] Results analysis: The photochromic pearlescent pigments of Examples 1 and 2 are significantly better than those of Comparative Examples 1 and 2 in terms of light resistance, heat resistance and water resistance. The water-sensitive photochromic powder used in Example 1 has a certain compatibility and can be more evenly dispersed in the system, thereby improving the quality and performance stability of the product. By adjusting the preparation process and formula of the water-sensitive photochromic powder, such as multi-frequency ultrasound, its color change effect and sensitivity can be precisely controlled.

[0064] Example 2: Mixing the photosensitive color-changing powder and the oily system has better solubility and dispersibility. During the preparation process of the dry adsorption method, the oily photosensitive color-changing powder can adhere well to the surface of the pearlescent pigment to form a uniform covering layer, so that the final product not only has a pearlescent effect, but also has the characteristics of photosensitive color-changing, can resist the influence of environmental factors such as ultraviolet rays, high temperature, and humidity on the performance of the pigment, and maintain a stable color-changing effect for a long time.

[0065] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A photosensitive color-changing pearlescent pigment, characterized in that: The invention comprises the following raw materials in parts by weight: 40-60 parts of pearlescent pigment, 5-20 parts of photochromic powder, 15-25 parts of metal oxide, 1-5 parts of silane coupling agent, 0.5-2 parts of dispersant and 20-40 parts of adhesive; the pearlescent pigment is mica flake, the photochromic powder is water-based photochromic powder or oil-based photochromic powder, the metal oxide is titanium dioxide, iron oxide, zinc oxide or aluminum oxide, and the adhesive is acrylic resin or polyurethane resin.

2. A photochromic pearlescent pigment as claimed in claim 1, characterized in that: The preparation method of the water-based photochromic powder comprises the following steps: dispersing a photochromic compound in an aqueous carrier with a solid-liquid ratio of 1:0.5-1 to form a uniform solution, wherein the aqueous carrier is deionized water or an ethanol solution with a mass concentration of 60-80%, adding 0.3-1% by volume of an ultraviolet absorber BP-4 at a stirring rate of 400-600rpm, controlling the temperature at 25-60°C, the pressure at 0.6-1.5MPa, and the pH at 6-8 to perform a multi-frequency ultrasonic combined mixing reaction for 3-5h, purifying, and drying to form the water-based photochromic powder.

3. A photochromic pearlescent pigment as claimed in claim 2, characterized in that: The multi-frequency ultrasound parameters are: any one of frequencies of 10, 15, and 20 kHz, power of 300-600 W, time of 5-20 min, and interval of 10-15 min.

4. The photosensitive color-changing pearlescent pigment according to claim 1, characterized in that: The oily photochromic powder is prepared by dissolving a photochromic compound in xylene with a mass-to-volume ratio of 8-12:50 in g / mL, then adding 40-60% of polystyrene by mass of the compound to the solution at 40-60° C., adding 20-30% of sodium dodecylbenzene sulfonate by mass of the compound, emulsifying the mixture in a high shear emulsifier at a speed of 10000-20000 rpm for 20-40 minutes to form a stable emulsion, then adding 10-15% of benzoyl peroxide by mass of the compound, maintaining the temperature at 70-80° C., reacting for 2-4 hours, purifying and dispersing the mixture to obtain the oily photochromic powder.

5. A photochromic pearlescent pigment as claimed in claim 3 or 4, characterized in that: The photochromic compound is any one or a combination of spiropyran, spirooxazine, naphthopyran, fulgide, and diarylethene compounds.

6. The photosensitive color-changing pearlescent pigment according to claim 1, characterized in that: The silane coupling agent is selected from kh-570 silane coupling agent, kh-560 silane coupling agent or kh-550 silane coupling agent.

7. The photochromic pearlescent pigment according to claim 1, characterized in that: The dispersant includes, but is not limited to, sodium stearate, sodium dodecyl sulfate, sodium dodecylbenzene sulfonate, polyvinyl alcohol hydroxypropyl methylcellulose, nonylphenol polyoxyethylene ether, polyoxyethylene alkylamine, and fatty acid polyoxyethylene ester.

8. The method for preparing a photosensitive color-changing pearlescent pigment according to claim 1, characterized in that: The method is liquid deposition, comprising the following steps: a. Pretreatment: put the pearlescent pigment into a reactor with deionized water, the solid-liquid ratio g / mL is 1:6-20, stir the system at a speed of 200-400rpm, stir for 10-20min, and obtain a pearlescent slurry; b. The pearlescent slurry is heated to 60-90°C, the reaction pressure is 1-5kPa, and stirred at a rate of 500-1000rpm for 15-30min; c. Continue to add silane coupling agent to the above pearlescent slurry, stir evenly, then slowly add water-sensitive photochromic powder and metal oxide, and continue to react for 1-4h; d. Add dispersant and binder to the above system in sequence and stir for 1-2h; e. After washing, filtering and drying at 50-150°C, a photosensitive color-changing pearlescent pigment is obtained.

9. The method for preparing a photosensitive color-changing pearlescent pigment according to claim 1, characterized in that: The preparation is carried out by a dry adsorption method, comprising the following steps: a. Put pearlescent pigment, oily photochromic powder and metal oxide into a powder mixer and mix for 0.5-2h; b. Add silane coupling agent and continue mixing for 20-40 minutes to allow the silane coupling agent to be evenly dispersed and act on the surface of the mixture; c. Add dispersant and binder to the above system in sequence and stir for 1-2h; d. Place the mixed materials in an oven and dry them at 50-100°C for 2-4 hours to solidify the adhesive and firmly combine the components to obtain a photosensitive color-changing pearlescent pigment.

10. A method of using the photochromic pearlescent pigment according to any one of claims 1 to 7 in cosmetics, coatings, inks or plastic products.

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