An inorganic pearlescent pigment with cochineal-like color and a preparation method thereof

Abstract

The present application relates to the technical field of pearl pigment, and particularly relates to an inorganic pearl pigment with imitation cochineal red phase and a preparation method thereof. The inorganic pearl pigment with imitation cochineal red phase comprises a lamellar base material, the lamellar base material is sequentially coated with coating layers with different refractive indexes, and the coating layers comprise a first layer of high-refractive-index metal oxide, a low-refractive-index crosslinking layer, a promoting layer and a second layer of high-refractive-index metal oxide arranged in sequence. The purpose is to make the pearl pigment composition free of any organic colorant, and the prepared pearl pigment with imitation cochineal red phase has high brightness and color saturation, the stacking color phase is comparable to cochineal red lake, and the pearl pigment with imitation cochineal red phase also has good dispersibility, solvent resistance and weather resistance.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of pearl pigment, in particular to an inorganic pearl pigment with imitation cochineal red and a preparation method thereof. BACKGROUND

[0002] Pearl pigment refers to a new type of high-tech pigment with a layer of metal oxide film coated on the surface of a transparent flaky substrate, which produces a pearl-like soft luster by using the principle of thin film light reflection and interference. By changing the thickness of the metal oxide thin layer, different pearl effects can be produced. The purple red series pearl pigment is very frequently used in makeup, which is mainly Fe2O3 series pearl and cochineal red series colored pearl.

[0003] Cochineal red is a red pigment extracted from the female cochineal body parasitized on cactus plants. It is obtained by grinding the female cochineal body and then extracting it with water. The main component is cochineal acid (also known as carmine acid, which is an anthraquinone derivative). Cochineal red used in cosmetics may cause allergic reactions, and it also has the phenomena of bleeding and uneven dispersion in cosmetics. Moreover, it is derived from animals, which is not consistent with the increasingly stringent animal-free concept of cosmetics.

[0004] Chinese patent ZL201110406040.2 discloses a high-saturation iron series pigment and a production method thereof. It is proposed that a high-saturation iron series pearl pigment can be obtained by a "mica / Fe2O3 / SiO2 / Fe2O3" coating method. This process is a multi-layer coating method, and the coating layer is relatively thick. There are more free iron oxides in the product, which causes the product to be unclear and transparent, and the color is biased towards jujube red, the color is dark and the brightness is not enough. In actual production, in order to solve this problem, the pearl pigment after high-temperature calcination is usually dispersed in water again, and then heated and soaked, and then filtered and washed, so as to remove the free metal oxide particles in the pearl. However, this method will increase the production cost, the free material treatment is not clean, the product color will change, and the product stability will be reduced. SUMMARY

[0005] Therefore, the purpose of the present application is to provide an inorganic pearl pigment with imitation cochineal red and a preparation method thereof, so that the pearl pigment composition does not contain any organic colorant, and the imitation cochineal red pearl pigment prepared has high brightness and color saturation, the stacking color is comparable to cochineal red lake, and also has good dispersibility, solvent resistance and weather resistance.

[0006] The present application solves the above technical problems by the following technical means:

[0007] An inorganic pearl pigment with cochineal red color phase, comprising a sheet layer substrate, the sheet layer substrate is coated with coating layers with different refractive indexes in sequence, the coating layers comprise a first layer of high refractive index metal oxide, a low refractive index crosslinking layer, a promoting layer and a second layer of high refractive index metal oxide arranged in sequence.

[0008] By adopting the coating layers with high-low-high refractive indexes, the prepared pearl pigment has high brightness and color saturation, the stacking color phase is comparable to cochineal red lake, and the pearl pigment also has good dispersibility, solvent resistance and weather resistance, so that when the pearl pigment is applied to cosmetics, no bleeding, fading and uneven dispersion phenomenon occurs.

[0009] In the scheme, the second layer of high refractive index metal oxide is further coated with a silica layer, and by coating the silica layer, the cracks on the surface of the second layer of high refractive index metal oxide caused by the thickness of the coating during high-temperature calcination can be avoided, and the diffuse reflection of light can be avoided, so that the brightness and the brightness of the product are reduced. The silica layer is very thin and basically does not affect the brightness and color saturation of the pearl pigment.

[0010] Preferably, the sheet layer substrate is one of transparent natural mica, synthetic mica, glass flake, sheet-shaped silicon oxide and sheet-shaped aluminum oxide, and the particle size of the sheet layer substrate is 5-60um.

[0011] Further preferably, in the scheme, the sheet layer substrate uses synthetic mica, which has lower cost and can avoid invalid impurities. The particle size of the sheet layer substrate is less than 5um, and when the sheet layer substrate is coated with multiple layers of metal oxide, due to the increase of the coating thickness, it becomes a near-spherical state, which increases the scattering of light and causes the brightness and the brightness of the product to deviate; on the contrary, when the particle size exceeds 60um, due to the increase of the sheet area, it is difficult to build a coating layer with excellent color development.

[0012] In the scheme, the particle size of the sheet layer substrate is further preferably 8-35um, so that when the multiple layers of metal oxide are coated, an excellent color development coating layer can be formed.

[0013] Preferably, the mass of the first layer of high refractive index metal oxide is 60-90% of the mass of the sheet layer substrate.

[0014] Further preferably, the mass of the first layer of high refractive index metal oxide is 70-80% of the mass of the sheet layer substrate, and by controlling the mass ratio of the first layer of high refractive index metal oxide to the sheet layer substrate, the first layer of metal oxide can completely coat the sheet layer substrate, so that the first layer of coating is more uniform in color development and presents a wine red color.

[0015] In the scheme, the first layer of high refractive index metal oxide is ferric oxide.

[0016] Preferably, the low refractive index cross-linking layer has a mass of 20-40% of the mass of the sheet layer substrate.

[0017] Further preferably, the low refractive index cross-linking layer has a mass of 20-30% of the mass of the sheet layer substrate. By controlling the mass ratio of the low refractive index cross-linking layer to the mass of the sheet layer substrate, the cross-linking layer can completely coat the ferric oxide particles, and also reduce the release of the particles, avoiding the self-agglomeration of the coated metal oxide nanoparticles in the subsequent process, thereby affecting the color purity of the product.

[0018] In this solution, the low refractive index cross-linking layer is SiO2-Al2O3, i.e., the aluminum oxide is cross-linked on the silicon dioxide. By co-deposition of the generated silicon dioxide and aluminum oxide at a certain temperature, the metal oxides are cross-linked with each other, and due to the doping of Al2O3, the coating film of the cross-linking layer is more compact. The difference in refractive index between aluminum oxide and silicon dioxide is small, and will not affect the color effect caused by the optical effect. Also, it can adsorb the released SiO2 particles (the isoelectric point of SiO2 particles is at pH = 2.0, the isoelectric point of Al2O3 particles is at pH = 8.0, at pH 6.0-7.0, the surface of SiO2 particles is negatively charged, while the surface of Al2O3 particles is positively charged, and at a certain temperature and pH, they can co-deposit), thereby synergistically promoting the binding firmness between the silicon dioxide particles, making the combination between them more compact, reducing the release of silicon dioxide particles, and forming a smoother and continuous film layer during calcination.

[0019] Preferably, the promoting layer has a mass of 4-8% of the mass of the sheet layer substrate.

[0020] Further preferably, the promoting layer has a mass of 5-6% of the mass of the sheet layer substrate. Through the action of the promoting layer, the second layer of high refractive index metal oxide (TiO2) can be converted from anatase to rutile phase in the subsequent calcination process, thereby making the finished pearlescent pigment have good weather resistance and temperature resistance. Since the promoting layer itself has a high refractive index, the finished product has higher brightness and color saturation.

[0021] In this solution, the promoting layer is tin oxide.

[0022] Preferably, the second layer of high refractive index metal oxide has a mass of 70-100% of the mass of the sheet layer substrate.

[0023] Further preferably, the second layer of high refractive index metal oxide has a mass of 80-90% of the mass of the sheet layer substrate. By controlling the mass ratio of the second layer of high refractive index metal oxide to the sheet layer substrate, the pigment can exhibit a higher color saturation and brightness of the cochineal red phase when the second layer of metal oxide completely coats the promoting layer.

[0024] The application also discloses a preparation method of the inorganic pearl pigment.

[0025] S1. Disperse the pretreated sheet layer substrate into a slurry in deionized water, stir and heat to 80-90 DEG C, dropwise add iron chloride solution, meanwhile add sodium hydroxide solution, control the pH of the slurry to be 3.0-3.5, after adding the iron chloride solution, constant temperature stirring for 1-2 h, after the reaction is completed, a first reaction liquid is obtained and reserved;

[0026] S2. Dropwise add sodium silicate solution into the first reaction liquid, meanwhile use aluminum chloride solution, constantly control the pH to be 6.0-7.0, after adding the sodium silicate solution, constant temperature stirring for 2-3 h, after the reaction is completed, a second reaction liquid is obtained and reserved;

[0027] S3. Cool the second reaction liquid to 60-70 DEG C, place in a constant temperature water bath, dropwise add tin tetrachloride acid solution, meanwhile add sodium hydroxide solution, constantly control the pH of the reaction liquid to be 1.3-1.5, after adding the tin tetrachloride solution, constant temperature stirring for 0.5-1 h, after the reaction is completed, a third reaction liquid is obtained and reserved;

[0028] S4. Stir and heat the third reaction liquid to 70-80 DEG C, dropwise add titanium tetrachloride solution, meanwhile use sodium hydroxide solution, constantly control the pH of the reaction liquid to be 1.5-2.0, after adding the titanium tetrachloride solution, constant temperature stirring for 1-2 h, a fourth reaction liquid is obtained and reserved;

[0029] S5. Post-treat the fourth reaction liquid, after post-treatment, the upper suspension is removed by sedimentation, filtration, washing, drying and calcination, and the finished product is obtained.

[0030] Through the above steps, the pearl pigment with the color of cochineal red can be prepared, the brightness and color saturation of the pearl pigment are high, the color of the stacked pearl pigment is comparable to that of cochineal red lake, meanwhile, the pearl pigment has good dispersibility, solvent resistance and weather resistance, and when applied to makeup, the pearl pigment will not appear color bleeding and uneven dispersion.

[0031] Preferably, in the S1 step, the treatment step of the pretreated sheet layer substrate is: disperse the sheet substrate in deionized water, then add sodium metasilicate solution, ultrasonic dispersion, stir and heat to 90 DEG C, and constant temperature stirring for 1-2 h, filtration, and the pH of the filtrate is 7-8, to obtain the pretreated sheet layer substrate.

[0032] In the scheme, the solid-liquid ratio of the sheet layer substrate and deionized water is 1:10-20; the mass of sodium metasilicate is 10-15% of the mass of the sheet layer substrate, so that the optimal and most economical surface treatment effect is achieved.

[0033] By using sodium metasilicate to treat the flaky substrate, the number of hydroxyl groups on the surface of the flaky substrate can be increased, which is beneficial to the bonding strength between the ferrous oxide film layer and the substrate.

[0034] Preferably, in the S5 step, the specific post-treatment step is: constant temperature stirring at 70-80℃, then slowly adding sodium silicate solution to the pH value of the fourth reaction solution to 5.0-6.0, then constant temperature stirring for 1-2h, then adding a surfactant, and constant temperature stirring for 1h.

[0035] By adjusting the concentration of the sodium silicate solution, the free titanium oxide nanoparticles in the solution system are further adsorbed and bonded by the transparent silicon oxide particles, and at the same time, the cracking of the outermost titanium oxide film layer during subsequent high-temperature calcination due to the thickness of the coating is solved, which causes the light to be diffusely reflected, resulting in a decrease in the brightness and vividness of the product. That is, the addition of sodium silicate forms a very thin SiO2 layer during calcination, which can prevent the surface of the titanium oxide film layer from cracking.

[0036] By using a surfactant, the free metal oxide particles that cannot be firmly coated on the pearlitic substrate can be further suspended, and the free metal oxide particles in the final powder can be reduced by sedimentation and filtration washing, thereby improving the purity and color vividness of the product.

[0037] Preferably, the mass of the surfactant is 0.05-0.2% of the mass of the flaky substrate.

[0038] By controlling the amount of surfactant, when it is less than 0.05%, the suspension effect is poor, and when it is more than 0.2%, the cost increases but the effect does not change.

[0039] Further preferably, the surfactant is a fatty alcohol polyoxyethylene ether.

[0040] The application using the above scheme has the following beneficial effects:

[0041] 1. The application discloses a simulated cochineal red-like pearlescent pigment, which has high color purity and vividness, and its stacking color is comparable to that of cochineal red. Moreover, the composition of the pigment is inorganic, and the pigment is weather-resistant, temperature-resistant, and non-bleeding. The application solves the problem of avoiding the use of animal-derived ingredients and organic pigments in makeup.

[0042] 2. By using SiO2-Al2O3 to replace the traditional SiO2 to form a low-refraction layer, a very thin coating thickness can highlight high brightness and high color purity. At the same time, the adsorption tightness of the SiO2 coating is improved, and the free SiO2 nanoparticles are reduced, thereby avoiding the self-agglomeration of the coated metal oxide nanoparticles due to the free SiO2, which affects the color purity of the product.

[0043] 3. In the preparation process, the low concentration sodium silicate solution is used to adjust the value, which can form a very thin silicon oxide film layer on the pearl surface, and can further adsorb the free nano titanium oxide particles in the system; avoid the thick film structure, the outermost film layer appears crack due to high temperature calcination, thereby causing diffuse reflection, and the purity of the product is reduced;

[0044] 4. By using surfactant to treat the pearl precursor, the nano metal oxide particles that fail to be coated on the pearl precursor can be effectively dispersed, the content of free metal oxide in the product is effectively reduced at low cost, and the clear and transparent feeling and brightness of the product are improved. BRIEF DESCRIPTION OF DRAWINGS

[0045] The present application can be further illustrated by the non-limiting examples shown in the accompanying drawings;

[0046] Figure 1 is a schematic diagram of the layered inorganic pearl pigment of the imitation cochineal red phase prepared in embodiments 1-3 of the present application;

[0047] Figure 2 is an XRF spectrum of the SiO2-Al2O3 crosslinked layer formed when adding aluminum chloride in embodiment 2 of the present application;

[0048] Figure 3 is an XRF spectrum of the synthetic mica substrate in the embodiment of the present application;

[0049] Figure 4 is a scanning electron microscope image of the SiO2 layer formed without adding aluminum chloride in embodiment 5 of the present application;

[0050] Figure 5 is a scanning electron microscope image of the SiO2-Al2O3 crosslinked layer formed when adding aluminum chloride in embodiment 2 of the present application;

[0051] Figure 6 is a scanning electron microscope image of the inorganic pearl pigment powder of the imitation cochineal red phase in embodiment 2 of the present application. DETAILED DESCRIPTION

[0052] The advantages and effects of the present application can be understood by those skilled in the art from the disclosure in the specification:

[0053] In the present application, the sheet substrate uses synthetic mica, which uses synthetic mica of 8-35 μm from Anhui Gexin New Material Technology Co., Ltd. The color value is measured by X·rite MA94 Spectrophotometer, wherein L value represents brightness / darkness, a value represents the range from red to green, b value represents the range from yellow to blue, and C value represents color saturation (chroma).

[0054] The product coating condition is observed by field emission scanning electron microscope (SEM) with the test conditions of accelerating voltage 5.0KV, probe current 20nA, and magnification 10-1000000x.

[0055] The crystal form of the iron oxide and titanium dioxide is determined by a D / Max-RA type rotating anode X-ray diffractometer of Rigaku Company, Japan;

[0056] Free metal oxide test in the product: 100mL of deionized water and 10g of finished product pearl are added into a 100mL measuring cylinder, stirred and uniformly dispersed, then left to stand for 10min, and the turbidity of the supernatant is observed.

[0057] Preparation of the inorganic pearlescent pigment with imitation cochineal red phase in Example 1

[0058] Pre-treatment of the sheet layer substrate

[0059] The transparent sheet synthetic mica and deionized water are uniformly dispersed according to the mass ratio of 1:10, then 10% of sodium metasilicate solution of the mass of the synthetic mica is added, ultrasonic dispersion is performed for 10min, the ultrasonic power is 500W, and the frequency is 40KHz. The temperature is increased to 90℃ under stirring, and constant temperature stirring is performed for 1-2h, then filtration is performed, deionized water is washed until the pH value of the filtrate is 7-8, and the pre-treated sheet layer substrate is obtained.

[0060] Preparation of the inorganic pearlescent pigment with imitation cochineal red phase

[0061] S1. The pre-treated sheet layer substrate is dispersed into a slurry in deionized water, the mass ratio of the sheet layer substrate to deionized water is 1:10, the temperature is increased to 80℃ under stirring, 1.0mol / L of iron chloride solution is added dropwise, 4.0mol / L of sodium hydroxide solution is added at the same time, the pH value of the slurry is controlled to be 3.0-3.5, after the addition of the iron chloride solution is completed, constant temperature stirring is performed for 1-2h, and after the reaction is completed, a first reaction liquid is obtained and reserved;

[0062] S2. 0.5mol / L of sodium silicate solution is added dropwise in the first reaction liquid, 0.5mol / L of aluminum chloride solution is added at the same time, the pH value is constantly controlled to be 6.0-7.0, after the addition of the sodium silicate solution is completed, constant temperature stirring is performed for 2-3h, and after the reaction is completed, a second reaction liquid is obtained and reserved;

[0063] S3. The second reaction liquid is cooled to 60℃ and placed in a constant temperature water bath, 0.1mol / L of tin tetrachloride acid solution is added dropwise, 4.0mol / L of sodium hydroxide solution is added at the same time, the pH value of the reaction liquid is constantly controlled to be 1.3-1.5, after the addition of the tin tetrachloride solution is completed, constant temperature stirring is performed for 0.5-1h, and after the reaction is completed, a third reaction liquid is obtained and reserved;

[0064] S4. The third reaction solution is stirred to 70°C, and 2.0 mol / L titanium tetrachloride solution is added dropwise while using 4.0 mol / L sodium hydroxide solution to constantly control the pH value of the reaction solution to 1.5-2.0. After the addition of the titanium tetrachloride solution is completed, constant temperature stirring is performed for 1-2 h to obtain a fourth reaction solution, which is reserved;

[0065] S5. The fourth reaction solution is stirred to constant temperature at 70°C, and 0.05 mol / L sodium silicate solution is slowly added dropwise until the pH value of the suspension is 5.0-6.0. Constant temperature stirring is performed for 1-2 h, and then fatty alcohol polyoxyethylene ether is added, wherein the mass of the fatty alcohol polyoxyethylene ether is 0.05% of the mass of the synthetic mica. Constant temperature stirring is performed for 1 h, the upper suspension is removed by sedimentation, filtration, deionized water washing, drying, and calcination at 700-760°C to obtain a finished product.

[0066] Example 2, Preparation of an inorganic pearlescent pigment in imitation of cochineal red phase two

[0067] In this example, the raw materials and instruments are the same as in Example 1, and the test method is also the same.

[0068] The transparent flaky synthetic mica and deionized water are uniformly dispersed according to a mass ratio of 1:15, and then 10% of sodium metasilicate solution by mass of the synthetic mica is added. Ultrasonic dispersion is performed, and the ultrasonic dispersion conditions are the same as in Example 1. Stirring is performed to raise the temperature to 90°C, and constant temperature stirring is performed for 1-2 h. Filtration is performed, and deionized water washing is performed until the pH value of the filtrate is 7-8 to obtain a pretreated sheet layer base material.

[0069] Preparation of an inorganic pearlescent pigment in imitation of cochineal red phase

[0070] S1. The pretreated sheet layer base material is dispersed into a slurry in deionized water, wherein the mass ratio of the sheet layer base material to deionized water is 1:15. Stirring is performed to raise the temperature to 85°C, and 1.0 mol / L ferric chloride solution is added dropwise while adding 4.0 mol / L sodium hydroxide solution to control the pH of the slurry to 3.0-3.5. After the addition of the ferric chloride solution is completed, constant temperature stirring is performed for 1-2 h. After the reaction is completed, a first reaction solution is obtained, which is reserved;

[0071] S2. 0.5 mol / L sodium silicate solution is added dropwise into the first reaction solution while using 0.5 mol / L aluminum chloride solution to constantly control the pH value to 6.0-7.0. After the addition of the sodium silicate solution is completed, constant temperature stirring is performed for 2-3 h. After the reaction is completed, a second reaction solution is obtained, which is reserved;

[0072] S3. The second reaction solution is cooled to 65°C and placed in a constant temperature water bath. A 0.1 mol / L tin tetrachloride acid solution is added dropwise, and a 4.0 mol / L sodium hydroxide solution is added simultaneously. The pH value of the reaction solution is constantly controlled to be 1.3-1.5. After the tin tetrachloride solution is added, constant temperature stirring is performed for 0.5-1 h. After the reaction is completed, a third reaction solution is obtained and reserved;

[0073] S4. The third reaction solution is stirred and heated to 75°C. A 2.0 mol / L titanium tetrachloride solution is added dropwise, and a 4.0 mol / L sodium hydroxide solution is added simultaneously. The pH value of the reaction solution is constantly controlled to be 1.5-2.0. After the titanium tetrachloride solution is added, constant temperature stirring is performed for 1-2 h. A fourth reaction solution is obtained and reserved;

[0074] S5. The fourth reaction solution is stirred and heated to 75°C. A 0.05 mol / L sodium silicate solution is slowly added dropwise until the pH value of the suspension is 5.0-6.0. Constant temperature stirring is performed for 1-2 h. Fatty alcohol polyoxyethylene ether is added. The mass of the fatty alcohol polyoxyethylene ether is 0.1% of the mass of the synthetic mica. Constant temperature stirring is performed for 1 h. The upper suspension is removed by sedimentation, filtration, deionized water washing, drying, and calcination at 700-760°C to obtain a finished product.

[0075] Example 3, preparation of an inorganic pearl pigment in imitation of cochineal red

[0076] In this example, the raw materials and instruments are the same as in Example 1, and the test method is the same.

[0077] The transparent flaky synthetic mica and deionized water are uniformly dispersed according to a mass ratio of 1:20. A 10% sodium metasilicate solution by mass of the synthetic mica is added. Ultrasonic dispersion is performed. The ultrasonic dispersion conditions are the same as in Example 1. The temperature is stirred and raised to 90°C, and constant temperature stirring is performed for 1-2 h. Filtration is performed with deionized water washing until the pH value of the filtrate is 7-8. A pretreated flaky substrate is obtained.

[0078] Preparation of an inorganic pearl pigment in imitation of cochineal red

[0079] S1. The pretreated flaky substrate is dispersed into a slurry in deionized water. The mass ratio of the flaky substrate to deionized water is 1:20. The temperature is stirred and raised to 90°C. A 1.0 mol / L iron chloride solution is added dropwise, and a 4.0 mol / L sodium hydroxide solution is added simultaneously. The pH value of the slurry is controlled to be 3.0-3.5. After the iron chloride solution is added, constant temperature stirring is performed for 1-2 h. After the reaction is completed, a first reaction solution is obtained and reserved.

[0080] S2. Add 0.5 mol / L sodium silicate solution dropwise to the first reaction solution, while simultaneously using 0.5 mol / L aluminum chloride solution to maintain a constant pH value of 6.0-7.0. After adding the sodium silicate solution, stir the reaction at a constant temperature for 2-3 hours. After the reaction is complete, the second reaction solution is obtained and set aside for later use.

[0081] S3. Cool the second reaction solution to 70℃, place it in a constant temperature water bath, add 0.1mol / L tin tetrachloride acidic solution dropwise, and add 4.0mol / L sodium hydroxide solution at the same time. Keep the pH value of the reaction solution constant at 1.3-1.5. After the tin tetrachloride solution is added, stir at a constant temperature for 0.5-1h. After the reaction is completed, the third reaction solution is obtained and set aside.

[0082] S4. Stir and heat the third reaction solution to 80℃, add 2.0mol / L titanium tetrachloride solution dropwise, and simultaneously use 4.0mol / L sodium hydroxide solution to keep the pH value of the reaction solution constant at 1.5-2.0. After the titanium tetrachloride solution is added, stir at a constant temperature for 1-2 hours to obtain the fourth reaction solution for later use.

[0083] S5. Stir the fourth reaction solution and keep it at a constant temperature of 80°C. Slowly add 0.05 mol / L sodium silicate solution until the pH of the suspension reaches 5.0-6.0. Stir at a constant temperature for 1-2 hours. Then add fatty alcohol polyoxyethylene ether, wherein the mass of fatty alcohol polyoxyethylene ether is 0.2% of the mass of the synthesized mica. Stir at a constant temperature for 1 hour. Let the upper suspension settle and remove it. Filter, wash with deionized water, dry, and calcine at 700-760°C to obtain the finished product.

[0084] Example 4 (Comparative Example 1): Preparation of Cochineal Red Inorganic Pearlescent Pigment

[0085] Preparation of Cochineal Red Inorganic Pearlescent Pigments

[0086] S1. Disperse the sheet substrate in deionized water to form a slurry, wherein the mass ratio of the sheet substrate to deionized water is 1:15. Stir and heat to 85℃, add 1.0 mol / L ferric chloride solution dropwise, and simultaneously add 4.0 mol / L sodium hydroxide solution, controlling the pH of the slurry to 3.0-3.5. After adding the ferric chloride solution, stir at a constant temperature for 1-2 hours. After the reaction is complete, the first reaction solution is obtained and set aside.

[0087] S2. Add 0.5 mol / L sodium silicate solution dropwise to the first reaction solution, while simultaneously using 0.5 mol / L aluminum chloride solution to maintain a constant pH value of 6.0-7.0. After adding the sodium silicate solution, stir the reaction at a constant temperature for 2-3 hours. After the reaction is complete, the second reaction solution is obtained and set aside for later use.

[0088] S3. The second reaction solution is cooled to 65°C and placed in a constant temperature water bath. A 0.1 mol / L tin tetrachloride acid solution is added dropwise, and a 4.0 mol / L sodium hydroxide solution is added simultaneously. The pH value of the reaction solution is constantly controlled to be 1.3-1.5. After the tin tetrachloride solution is added, constant temperature stirring is performed for 0.5-1 h. After the reaction is completed, a third reaction solution is obtained and reserved;

[0089] S4. The third reaction solution is stirred and heated to 75°C. A 2.0 mol / L titanium tetrachloride solution is added dropwise, and a 4.0 mol / L sodium hydroxide solution is added simultaneously. The pH value of the reaction solution is constantly controlled to be 1.5-2.0. After the titanium tetrachloride solution is added, constant temperature stirring is performed for 1-2 h. A fourth reaction solution is obtained and reserved;

[0090] S5. The fourth reaction solution is stirred and heated to 75°C. A 0.05 mol / L sodium silicate solution is slowly added dropwise until the pH value of the suspension is 5.0-6.0. Constant temperature stirring is performed for 1-2 h. Fatty alcohol polyoxyethylene ether is added. The mass of the fatty alcohol polyoxyethylene ether is 0.1% of the mass of the synthetic mica. Constant temperature stirring is performed for 1 h. The upper suspension is removed by sedimentation, filtration, deionized water washing, drying, and calcination at 700-760°C to obtain a finished product.

[0091] Example 5 (Comparative Example 2), preparation of an inorganic pearl pigment in imitation of cochineal red

[0092] Pre-treatment of the sheet-shaped substrate

[0093] The transparent sheet-shaped synthetic mica is uniformly dispersed with deionized water at a mass ratio of 1:20. A 10% sodium metasilicate solution by mass of the synthetic mica is added. The ultrasonic dispersion conditions are the same as in Example 1. The temperature is raised to 90°C while stirring, and constant temperature stirring is performed for 1-2 h. The filter liquid is washed with deionized water until the pH value is 7-8. A pre-treated sheet-shaped substrate is obtained.

[0094] Preparation of an inorganic pearl pigment in imitation of cochineal red

[0095] S1. The pre-treated sheet-shaped substrate is dispersed into a slurry in deionized water. The mass ratio of the sheet-shaped substrate to deionized water is 1:20. The temperature is raised to 85°C while stirring. A 1.0 mol / L iron chloride solution is added dropwise, and a 4.0 mol / L sodium hydroxide solution is added simultaneously. The pH value of the slurry is controlled to be 3.0-3.5. After the iron chloride solution is added, constant temperature stirring is performed for 1-2 h. After the reaction is completed, a first reaction solution is obtained and reserved;

[0096] S2. In the first reaction liquid, 0.5 mol / L sodium silicate solution is added dropwise, and 8% hydrochloric acid solution is used to constantly control the pH value to 6.0-7.0. After the sodium silicate solution is added, constant temperature stirring reaction is carried out for 2-3 h. After the sodium silicate solution is added, constant temperature stirring reaction is carried out for 2-3 h. After the reaction is completed, the second reaction liquid is obtained and reserved.

[0097] S3. The second reaction liquid is cooled to 65°C and placed in a constant temperature water bath. 0.1 mol / L tin tetrachloride acid solution is added dropwise, and 4.0 mol / L sodium hydroxide solution is added at the same time. The pH value of the reaction liquid is constantly controlled to 1.3-1.5. After the tin tetrachloride solution is added, constant temperature stirring is carried out for 0.5-1 h. After the reaction is completed, the third reaction liquid is obtained and reserved.

[0098] S4. The third reaction liquid is stirred and heated to 75°C. 2.0 mol / L titanium tetrachloride solution is added dropwise, and 4.0 mol / L sodium hydroxide solution is used to constantly control the pH value of the reaction liquid to 1.5-2.0. After the titanium tetrachloride solution is added, constant temperature stirring is carried out for 1-2 h. The fourth reaction liquid is obtained and reserved.

[0099] S5. The fourth reaction liquid is stirred and heated to 75°C. 0.05 mol / L sodium silicate solution is slowly added dropwise until the pH value of the suspension is 5.0-6.0. Constant temperature stirring is carried out for 1-2 h. Fatty alcohol polyoxyethylene ether is added, wherein the mass of the fatty alcohol polyoxyethylene ether is 0.1% of the mass of the synthetic mica. Constant temperature stirring is carried out for 1 h. The upper suspension is removed by sedimentation, filtration, deionized water washing, drying, and calcination at 700-760°C to obtain the finished product.

[0100] Example 6 (Comparative Example 3), preparation of inorganic pearl pigment in imitation of cochineal red phase

[0101] Pre-treatment of sheet layer substrate

[0102] The transparent sheet-shaped synthetic mica is uniformly dispersed with deionized water at a mass ratio of 1:20. Then, 10% sodium metasilicate solution of the mass of the synthetic mica is added. The ultrasonic dispersion conditions are the same as those in Example 1. The stirring is heated to 90°C and constant temperature stirring is carried out for 1-2 h. The pre-treated sheet layer substrate is obtained by filtration and deionized water washing until the pH value of the filtrate is 7-8.

[0103] Preparation of inorganic pearl pigment in imitation of cochineal red phase

[0104] S1. The pretreated sheet substrate is dispersed into a slurry in deionized water, wherein the mass ratio of the sheet substrate to deionized water is 1:20, the temperature is increased to 85°C under stirring, 1.0 mol / L ferric chloride solution is added dropwise, 4.0 mol / L sodium hydroxide solution is added at the same time, the pH of the slurry is controlled to be 3.0-3.5, after the addition of the ferric chloride solution, constant temperature stirring is performed for 1-2 h, and after the reaction is completed, a first reaction liquid is obtained and reserved;

[0105] S2. 0.5 mol / L sodium silicate solution is added dropwise into the first reaction liquid, 0.5 mol / L aluminum chloride solution is added at the same time, the pH is constantly controlled to be 6.0-7.0, after the addition of the sodium silicate solution, constant temperature stirring is performed for 2-3 h, and after the reaction is completed, a second reaction liquid is obtained and reserved;

[0106] S3. The second reaction liquid is cooled to 65°C and placed in a constant temperature water bath, 0.1 mol / L tin tetrachloride acid solution is added dropwise, 4.0 mol / L sodium hydroxide solution is added at the same time, the pH of the reaction liquid is constantly controlled to be 1.3-1.5, after the addition of the tin tetrachloride solution, constant temperature stirring is performed for 0.5-1 h, and after the reaction is completed, a third reaction liquid is obtained and reserved;

[0107] S4. The third reaction liquid is stirred and heated to 75°C, 2.0 mol / L titanium tetrachloride solution is added dropwise, 4.0 mol / L sodium hydroxide solution is added at the same time, the pH of the reaction liquid is constantly controlled to be 1.5-2.0, after the addition of the titanium tetrachloride solution, constant temperature stirring is performed for 1-2 h, and a fourth reaction liquid is obtained and reserved;

[0108] S5. The fourth reaction liquid is stirred and heated to 75°C, 0.05 mol / L sodium silicate solution is slowly added dropwise until the pH of the suspension is 5.0-6.0, constant temperature stirring is performed for 1-2 h, the upper suspension is removed after sedimentation, filtration, deionized water washing, drying, and calcination at 700-760°C, and a finished product is obtained.

[0109] Example 7 (Comparative Example 4), preparation of an inorganic pearl pigment in imitation of cochineal red

[0110] Pre-treatment of the sheet substrate

[0111] The transparent sheet synthetic mica is uniformly dispersed with deionized water according to a mass ratio of 1:20, 10% sodium metasilicate solution of the synthetic mica is added, the ultrasonic dispersion conditions are the same as in Example 1, the temperature is increased to 90°C under stirring, and constant temperature stirring is performed for 1-2 h, filtration is performed, deionized water washing is performed until the pH of the filtrate is 7-8, and a pretreated sheet substrate is obtained.

[0112] Preparation of an inorganic pearl pigment in imitation of cochineal red

[0113] S1. The pretreated sheet substrate is dispersed into a slurry in deionized water, wherein the mass ratio of the sheet substrate to deionized water is 1:20, the temperature is increased to 85°C under stirring, 1.0 mol / L ferric chloride solution is added dropwise, 4.0 mol / L sodium hydroxide solution is added at the same time, the pH of the slurry is controlled to 3.0-3.5, after the addition of the ferric chloride solution, constant temperature stirring is performed for 1-2 h, and after the reaction is completed, a first reaction liquid is obtained and reserved;

[0114] S2. 0.5 mol / L sodium silicate solution is added dropwise into the first reaction liquid, 0.5 mol / L aluminum chloride solution is added at the same time, the pH is constantly controlled to 6.0-7.0, after the addition of the sodium silicate solution, constant temperature stirring is performed for 2-3 h, and after the reaction is completed, a second reaction liquid is obtained and reserved;

[0115] S3. The second reaction liquid is cooled to 65°C and placed in a constant temperature water bath, 0.1 mol / L tin tetrachloride acid solution is added dropwise, 4.0 mol / L sodium hydroxide solution is added at the same time, the pH of the reaction liquid is constantly controlled to 1.3-1.5, after the addition of the tin tetrachloride solution, constant temperature stirring is performed for 0.5-1 h, and after the reaction is completed, a third reaction liquid is obtained and reserved;

[0116] S4. The third reaction liquid is stirred and heated to 75°C, 2.0 mol / L titanium tetrachloride solution is added dropwise, 4.0 mol / L sodium hydroxide solution is added at the same time, the pH of the reaction liquid is constantly controlled to 1.5-2.0, after the addition of the titanium tetrachloride solution, constant temperature stirring is performed for 1-2 h, and a fourth reaction liquid is obtained and reserved;

[0117] S5. The fourth reaction liquid is stirred and heated to 75°C, fatty alcohol polyoxyethylene ether is added, wherein the mass of the fatty alcohol polyoxyethylene ether is 0.1% of the mass of the synthetic mica, constant temperature stirring is performed for 1 h, the upper suspension is removed after sedimentation, filtration, deionized water washing, drying, and calcination at 700-760°C are performed, and a finished product is obtained.

[0118] Example 8 (Comparative Example 5), preparation of an inorganic pearl pigment in imitation of cochineal red

[0119] Pre-treatment of the sheet substrate

[0120] The transparent sheet synthetic mica is uniformly dispersed with deionized water according to a mass ratio of 1:20, 10% of the mass of the synthetic mica is added as sodium metasilicate solution, the ultrasonic dispersion conditions are the same as in Example 1, the temperature is increased to 90°C under stirring, and constant temperature stirring is performed for 1-2 h, deionized water washing is performed until the pH of the filtrate is 7-8, and a pretreated sheet substrate is obtained.

[0121] Preparation of an inorganic pearl pigment in imitation of cochineal red

[0122] S1. Disperse the pretreated sheet substrate into a slurry in deionized water, wherein the mass ratio of the sheet substrate to deionized water is 1:20, stir to raise the temperature to 85℃, dropwise add 1.0 mol / L ferric chloride solution, at the same time add 4.0 mol / L sodium hydroxide solution, control the pH of the slurry to be 3.0-3.5, after adding the ferric chloride solution, constant temperature stirring for 1-2 h, after the reaction is completed, a first reaction liquid is obtained, ready for use;

[0123] S2. In the first reaction liquid, dropwise add 0.5 mol / L sodium silicate solution, at the same time with 0.5 mol / L aluminum chloride solution, constant control the pH value to 6.0-7.0, after adding the sodium silicate solution, constant temperature stirring reaction for 2-3 h, after the reaction is completed, a second reaction liquid is obtained, ready for use;

[0124] S3. Cool the second reaction liquid to 65℃, place it in a constant temperature water bath, dropwise add 0.1 mol / L tin tetrachloride acid solution, at the same time add 4.0 mol / L sodium hydroxide solution, constant control the pH value of the reaction liquid to be 1.3-1.5, after adding the tin tetrachloride solution, constant temperature stirring for 0.5-1 h, after the reaction is completed, a third reaction liquid is obtained, ready for use;

[0125] S4. Stir the third reaction liquid to raise the temperature to 75℃, dropwise add 2.0 mol / L titanium tetrachloride solution, at the same time with 4.0 mol / L sodium hydroxide solution, constant control the pH value of the reaction liquid to be 1.5-2.0, after adding the titanium tetrachloride solution, constant temperature stirring for 1-2 h, a fourth reaction liquid is obtained, filter, deionized water washing, drying, calcination under the condition of 700-760℃, to obtain the finished product.

[0126] The performance of the inorganic pearl pigment prepared in examples 1-8 is tested, which is scraped and coated first, and then placed on the testing instrument for testing, to test the L value, a value, b value and C value and the free degree, wherein the pearl pigment prepared in examples 1-3 is red-violet phase, and the bulk color is like the cochineal red phase, when judging, the value of 45° is mainly judged (because 45° is the closest to the angle of naked eye observation), and the C value is judged first, then the L value, and then the a value, and the test results are shown in the following table:

[0127]

[0128] From the data in the table, it can be seen that the red-violet phase pearl pigment prepared in examples 1-3 has high color saturation, brightness and better red-violet phase, wherein the color saturation, brightness and red-violet phase of the pearl pigment prepared in example 2 are the best.

[0129] The SiO2-Al2O3 crosslinked layer is tested after the reaction of the S2 step of the preparation of the pearlescent pigment in Example 2, and the SiO2-Al2O3 crosslinked layer is scanned by electron microscopy to obtain the SiO2-Al2O3 crosslinked layer coating diagram as shown in Figure 5 The SiO2-Al2O3 crosslinked layer is tested after the reaction of the S2 step of the preparation of the pearlescent pigment in Example 5. Since no aluminum chloride is added in the S2 step of Example 5, only the SiO2 layer can be obtained. The SiO2 is scanned by electron microscopy to obtain the electron microscopy diagram as shown in Figure 4 The SiO2-Al2O3 crosslinked layer is tested after the reaction of the S2 step of the preparation of the pearlescent pigment in Example 2, and the SiO2-Al2O3 crosslinked layer is scanned by electron microscopy to obtain the SiO2-Al2O3 crosslinked layer coating diagram as shown in

[0130] The SiO2-Al2O3 crosslinked layer is tested after the reaction of the S2 step of the preparation of the pearlescent pigment in Example 2, and the SiO2-Al2O3 crosslinked layer is scanned by electron microscopy to obtain the SiO2-Al2O3 crosslinked layer coating diagram as shown in Figure 2 The SiO2-Al2O3 crosslinked layer is tested after the reaction of the S2 step of the preparation of the pearlescent pigment in Example 2, and the SiO2-Al2O3 crosslinked layer is scanned by electron microscopy to obtain the SiO2-Al2O3 crosslinked layer coating diagram as shown in Figure 3 The SiO2-Al2O3 crosslinked layer is tested after the reaction of the S2 step of the preparation of the pearlescent pigment in Example 2, and the SiO2-Al2O3 crosslinked layer is scanned by electron microscopy to obtain the SiO2-Al2O3 crosslinked layer coating diagram as shown in The SiO2-Al2O3 crosslinked layer is tested after the reaction of the S2 step of the preparation of the pearlescent pigment in Example 2, and the SiO2-Al2O3 crosslinked layer is scanned by electron microscopy to obtain the SiO2-Al2O3 crosslinked layer coating diagram as shown in

[0131] It should be noted that although the flaky substrate itself contains aluminum oxide and silicon oxide, the content ratio of aluminum oxide to magnesium oxide and silicon oxide to magnesium oxide should not change without the addition of aluminum oxide and silicon oxide. The SiO2-Al2O3 crosslinked layer is tested after the reaction of the S2 step of the preparation of the pearlescent pigment in Example 2, and the SiO2-Al2O3 crosslinked layer is scanned by electron microscopy to obtain the SiO2-Al2O3 crosslinked layer coating diagram as shown in

[0132] The SiO2-Al2O3 crosslinked layer is tested after the reaction of the S2 step of the preparation of the pearlescent pigment in Example 2, and the SiO2-Al2O3 crosslinked layer is scanned by electron microscopy to obtain the SiO2-Al2O3 crosslinked layer coating diagram as shown in The SiO2-Al2O3 crosslinked layer is tested after the reaction of the S2 step of the preparation of the pearlescent pigment in Example 2, and the SiO2-Al2O3 crosslinked layer is scanned by electron microscopy to obtain the SiO2-Al2O3 crosslinked layer coating diagram as shown in

[0133] The SiO2-Al2O3 crosslinked layer is tested after the reaction of the S2 step of the preparation of the pearlescent pigment in Example 2, and the SiO2-Al2O3 crosslinked layer is scanned by electron microscopy to obtain the SiO2-Al2O3 crosslinked layer coating diagram as shown in The SiO2-Al2O3 crosslinked layer is tested after the reaction of the S2 step of the preparation of the pearlescent pigment in Example 2, and the SiO2-Al2O3 crosslinked layer is scanned by electron microscopy to obtain the SiO2-Al2O3 crosslinked layer coating diagram as shown in

[0134] It can be known by comparing the data in Example 2 and Example 6 that, in the S5 step, no surfactant is added, although the free matter is less, but there is still a certain amount of free matter, so that the free matter is more attached to the surface of the pearlescent pigment, which will affect the color saturation and brightness of the pearlescent pigment to some extent, and when the free degree test is carried out subsequently, it also shows that the addition of the surfactant can reduce the free matter attached to the surface of the pearlescent pigment.

[0135] It can be known by comparing the data in Example 2 and Example 7 that, in the S5 step, no sodium silicate solution is added, so that the outermost silicon oxide layer is not formed during calcination, which will cause the surface of the pearlescent pigment to crack due to high-temperature calcination, the color saturation will not decrease obviously under the action of diffuse reflection, but the brightness will decrease obviously, the purity will decrease, and the free matter will be more, which shows that, in the S5 step, by adding sodium silicate, the free nano titanium oxide particles in the system can be further adsorbed and the surface flatness of the outermost film layer can be improved.

[0136] It can be known by comparing the data in Example 2 and Example 8 that, if no sodium silicate and surfactant are added during the preparation of the pearlescent pigment, cracks will occur due to high-temperature calcination during calcination, the color saturation and brightness will decrease obviously, the purity will decrease, and the free matter will be more, which will cause more free matter to be attached to the surface of the pearlescent pigment, which shows that, in the S5 step, by adding sodium silicate and surfactant, on the one hand, the free nano titanium oxide particles in the system can be further adsorbed, and on the other hand, the free matter that is not adsorbed can be suspended in the upper layer of the liquid, which can play a synergistic effect to reduce the attachment of the free matter on the surface of the pearlescent pigment.

[0137] In summary, in the preparation process, SiO2-Al2O3 is formed to replace the traditional SiO2 to form a low-refraction layer, which can highlight high brightness and high color purity with very thin coating thickness; at the same time, the adsorption tightness of the SiO2 coating is improved, the free SiO2 nanoparticles are reduced, the color purity of the product is improved, and the sodium silicate and surfactant are used for post-treatment, which can further adsorb the free nano titanium oxide particles in the system and reduce the attachment of the free matter on the surface of the pearlescent pigment, so that the color purity and brightness of the prepared pearlescent pigment are high, the color of the product is comparable to that of cochineal, and the product also has good properties such as dispersion, weather resistance, temperature resistance, and non-permeability, which can be more widely used in makeup.

[0138] The above provides a kind of imitation cochineal inorganic pearlescent pigment and its preparation method. The specific embodiment is only used to help understand the method and its core idea of the present application. It should be pointed out that for ordinary skilled in the art, without departing from the principles of the present application, some improvements and modifications can be made to the present application, which also fall within the scope of protection of the claims of the present application.

[0139] It should be particularly noted that, if the specific experimental steps or conditions are not indicated in the examples, the operation or conditions can be carried out according to the conventional experimental steps described in the literature in the art. If the manufacturer of the reagent or instrument is not indicated, it is a conventional reagent product that can be obtained by purchase in the market.

[0140] The above examples are for better further understanding of the present application and do not limit the content and protection scope of the present application. Any product that is the same as or similar to the present application obtained by the inspiration of the present application or the combination of the present application with other prior art features falls within the protection scope of the present application.

Claims

1. A process for the preparation of an inorganic pearlescent pigment mimicking cochineal red phase, characterized in that, It comprises the following steps: S1. The pretreated sheet substrate is dispersed into a slurry in deionized water, stirred and heated to 80-90℃, and then the ferric chloride solution is added dropwise while the sodium hydroxide solution is added, the pH of the slurry is controlled to be 3.0-3.5, after the addition of the ferric chloride solution is completed, constant temperature stirring is carried out for 1-2h, and after the reaction is completed, a first reaction liquid is obtained for standby; S2. The sodium silicate solution is added dropwise into the first reaction liquid while the aluminum chloride solution is added, the pH value is constantly controlled to be 6.0-7.0, after the addition of the sodium silicate solution is completed, constant temperature stirring is carried out for 2-3h, and after the reaction is completed, a second reaction liquid is obtained for standby; S3. The second reaction liquid is cooled to 60-70℃, placed in a constant temperature water bath, the acidic stannic chloride solution is added dropwise while the sodium hydroxide solution is added, the pH value of the reaction liquid is constantly controlled to be 1.3-1.5, after the addition of the stannic chloride solution is completed, constant temperature stirring is carried out for 0.5-1h, and after the reaction is completed, a third reaction liquid is obtained for standby; S4. The third reaction liquid is stirred and heated to 70-80℃, the titanium tetrachloride solution is added dropwise while the sodium hydroxide solution is added, the pH value of the reaction liquid is constantly controlled to be 1.5-2.0, after the addition of the titanium tetrachloride solution is completed, constant temperature stirring is carried out for 1-2h, and a fourth reaction liquid is obtained for standby; S5. The fourth reaction liquid is post-treated, after the post-treatment, the upper suspension is removed by sedimentation, filtration, washing, drying and calcination to obtain a finished product; In the S1 step, the treatment steps of the pretreated sheet substrate are as follows: the sheet substrate is dispersed in deionized water, then the sodium metasilicate solution is added, ultrasonic dispersion is carried out, stirring and heating to 90℃ is carried out, and constant temperature stirring is carried out for 1-2h, filtration is carried out, the pH value of the filtrate is washed to be 7-8, and the pretreated sheet substrate is obtained; In the S5 step, the specific steps of the post-treatment are as follows: constant temperature stirring is carried out at 70-80℃, then the sodium silicate solution is slowly added dropwise until the pH value of the fourth reaction liquid is 5.0-6.0, constant temperature stirring is carried out for 1-2h, then the surfactant is added, and constant temperature stirring is carried out for 1h; An inorganic pearl pigment with Dactylopius coccus Costa-like red appearance comprises a sheet substrate, the sheet substrate is sequentially coated with coating layers with different refractive indexes, and the coating layers comprise a first layer of high-refractive-index metal oxide, a low-refractive-index crosslinking layer, a promoting layer and a second layer of high-refractive-index metal oxide which are sequentially arranged; The mass of the first layer of high-refractive-index metal oxide is 60-90% of the mass of the sheet substrate, and the first layer of high-refractive-index metal oxide is ferric oxide; The mass of the low-refractive-index crosslinking layer is 20-40% of the mass of the sheet substrate, and the low-refractive-index crosslinking layer is SiO2-Al2O3; The mass of the promoting layer is 4-8% of the mass of the sheet substrate, and the promoting layer is tin oxide; The mass of the second layer of high-refractive-index metal oxide is 70-100% of the mass of the sheet substrate, and the second layer of high-refractive-index metal oxide is TiO2; The sheet substrate is one of transparent natural mica, synthetic mica, glass flake, sheet-shaped silicon oxide and sheet-shaped aluminum oxide, and the particle size of the sheet substrate is 5-60um.

2. A process for the preparation of a cochineal red-like inorganic pearlescent pigment according to claim 1, characterized in that, The mass of the surfactant is 0.05-0.2% of the mass of the sheet substrate.

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