An environmentally friendly washable solid pigment and its preparation method

Abstract

The present invention relates to an environmentally friendly washable solid pigment and a preparation method thereof. The pigment comprises the following raw materials in parts by weight: 40 - 60 parts of PEG, 2 - 4 parts of stabilizer, 2 - 4 parts of washable film-forming agent, 15 - 25 parts of filler, 0.5 - 1.5 parts of toner, and 4.5 - 13.5 parts of water. Among them, the average molecular weight of the PEG is 6000 - 8000, the stabilizer comprises potassium lauryl phosphate and sodium dodecylbenzenesulfonate, the washable film-forming agent comprises carrageenan, gum ghatti, and carboxymethyl starch with a mass ratio of 1:1:(0.5 - 1.2), and the filler comprises alumina, magnesia, heavy calcium, and kaolin. The pigment of the present invention has good water solubility, is easy to spread after painting with water, has bright colors, stable performance, and good water solubility, and is easy to clean on the skin and fabrics.

Description

Technical Field

[0001] The present invention relates to the technical field of watercolor pigments, and particularly relates to an environmentally friendly washable solid pigment and a preparation method thereof. Background Art

[0002] Watercolor pigments are delicate and transparent, and can produce a transparent and bright effect by reflecting the luster of the white watercolor paper covered by the color. Watercolor painting uses water as a medium. Since water has fluidity, special effects can be produced, which is different from the artistic expression methods of other painting types. The fluidity of water, the dry-wet, thick-thin changes of water-soluble colors, and the penetration effect on paper during the painting process endow watercolor paintings with strong expressiveness.

[0003] Although watercolor pigments are easier to clean compared to traditional pigments, not all washable pigments can be easily washed clean. Some pigments may contain staining components that are difficult to remove, and may not be completely removed even with soap or detergent. The staining intensity of some washable pigments is relatively high, and once they stain clothes or furniture, they may leave indelible marks. At the same time, the components of certain solid watercolor pigment compositions may not be easily soluble in water or have poor mobility, resulting in the pigment components not being fully dissolved and moved to the pen side when rubbed with a water-containing pen. Summary of the Invention

[0004] The purpose of the present invention is to overcome the deficiencies of the prior art and provide an environmentally friendly washable solid pigment and a preparation method thereof, which have the advantages of being easy to clean, bright in color, safe and environmentally friendly, and convenient for storage.

[0005] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0006] In the first aspect, the present invention provides an environmentally friendly washable solid pigment, comprising the following raw materials in parts by weight:

[0007] 40 - 60 parts of PEG, 2 - 4 parts of stabilizer, 2 - 4 parts of washable film-forming agent, 15 - 25 parts of filler, 0.5 - 1.5 parts of color powder, and 4.5 - 13.5 parts of water. Among them, the average molecular weight of the PEG is 6000 - 8000, the stabilizer includes potassium lauryl phosphate and sodium dodecylbenzenesulfonate, the washable film-forming agent includes carrageenan, gum ghatti, and carboxymethyl starch in a mass ratio of 1:1:(0.5 - 1.2), and the filler includes alumina, magnesia, heavy calcium, and kaolin.

[0008] The solid pigment of the present invention is based on PEG, and the average molecular weight of PEG is between 6000 and 8000, which results in a relatively high viscosity of the pigment. To avoid the aggregation and sedimentation of powder materials such as fillers and color powders, potassium lauryl phosphate and sodium dodecylbenzenesulfonate are added. This can reduce the interfacial tension between pigment particles, making the pigment particles mix more evenly, thereby improving the pigment stability. At the same time, potassium lauryl phosphate has good skin compatibility and is mild and low-irritating, which also enables it to provide a more gentle and effective cleaning effect when the pigment needs to be washed off the skin.

[0009] Because the PEG content and average molecular weight of the solid pigment of the present invention are relatively high, the solid pigment is in a semi-dry jelly state. Moreover, PEG is a non-ionic surfactant that can reduce the surface tension of water, increase the wettability of the pigment, and enable the solid pigment to be fully dissolved when used with water dipped, facilitating the movement of the brush when painting.

[0010] The washable film-forming agent of the present invention refers to a film layer that can be formed after the pigment dries, but this film layer is easily washed off by water, and even if the pigment is accidentally splashed on the skin, it can be easily washed off. Specifically, the washable film-forming agent is composed of carrageenan, carboxymethyl starch, and gum ghatti. Carrageenan is a water-soluble polysaccharide that can form a gel-like structure, which helps the dispersion and dissolution of the pigment in water; carboxymethyl starch is a water-soluble modified starch, and its carboxymethyl group increases the hydrophilicity of the molecule, which can improve the water solubility of the pigment; gum ghatti is also a water-soluble natural colloid with good emulsifying and dispersing properties, which can enhance the dissolution of the pigment in water. In the present invention, carrageenan can form a tough and transparent thin film with good film-forming properties and can be used as a film-forming agent for watercolor pigments; carboxymethyl starch can increase the strength and flexibility of the film and improve the film-forming property of the pigment; gum ghatti can enhance the stability and ductility of the film due to its protein component, which helps to form a uniform and dense film. The synergistic effect can be produced when carrageenan, carboxymethyl starch, and gum ghatti are added in a specific dosage ratio, thereby improving the dispersibility and film-forming property of the pigment. At the same time, since all three are water-soluble components, when the pigment stains the skin or furniture, it can be removed by rinsing with water.

[0011] In the filler of the present invention, a composition containing alumina, magnesia, heavy calcium carbonate and kaolin is selected. When nano-scale alumina and magnesia are mixed with PEG, they will fill the voids between PEG molecules, thereby reducing the free volume between PEG molecules. This physical filling effect will limit the movement space of the PEG molecular chain, making it more difficult for the PEG molecular chain to move or rearrange on a large scale when subjected to external force or temperature change. At the same time, because alumina and magnesia limit the interaction between PEG molecules, the crystallization tendency of PEG is reduced. Therefore, in addition to the filler function, alumina and magnesia can also synergistically support PEG to make it not easy to crystallize, while heavy calcium carbonate and kaolin can make the pigment more saturated and show color better.

[0012] Preferably, the weight part of PEG in the pigment is 50-55 parts.

[0013] Preferably, the filler comprises the following components in parts by weight: 5-8 parts of alumina, 5-6 parts of magnesia, 2-6 parts of heavy calcium carbonate, 3-5 parts of kaolin.

[0014] Preferably, the toner comprises at least one of titanium white, carbon black, phthalocyanine blue, phthalocyanine green, light fast yellow, light fast red, iron red, iron yellow, orange yellow, benzidine yellow, ruby red, silver bead, ultramarine blue, permanent violet, permanent pink, rose color source, permanent orange.

[0015] Preferably, the pigment further comprises 0.2-0.3 parts of preservative.

[0016] Preferably, the preservative is 2-methyl-4-isothiazolin-3-one and / or 2-methyl-5-chloro-4-isothiazolin-3-one.

[0017] Preferably, the stabilizer is a composition of potassium lauryl phosphate and sodium dodecylbenzenesulfonate with a mass ratio of 1:(0.5-1.5).

[0018] Preferably, the washable film-forming agent is a composition of carrageenan, gum ghatti and carboxymethyl starch with a mass ratio of 1:1:(1-1.2).

[0019] In a second aspect, the present invention provides a method for preparing an environmentally friendly washable solid pigment, comprising the following steps:

[0020] S1. Mix PEG and part of water, heat and stir at 80 - 90 °C until PEG is completely dissolved, cool down to 50 - 60 °C, then add alumina, magnesia and the washable film-forming agent, and stir evenly to obtain the base slurry. Among them, alumina and magnesia, as nanomaterials, will fill the voids between PEG molecules, thereby reducing the free volume between PEG molecules. This physical filling effect will limit the movement space of PEG molecular chains, making it more difficult for PEG molecular chains to move or rearrange on a large scale when subjected to external forces or temperature changes, thus reducing the crystallization tendency of PEG.

[0021] S2. Mix the stabilizer and the remaining water, then add color powder, heavy calcium and kaolin, and stir to obtain the color paste. Among them, the stabilizer can reduce the interfacial tension between pigment particles, making the pigment particles mix more evenly, thus improving the pigment stability.

[0022] S3. Mix the base slurry and the color paste, stir evenly, and cure the mixed slurry at 8 - 12 °C to obtain the environmentally friendly washable solid pigment.

[0023] Preferably, in step S1, the stirring speed is 200 - 400 r / min and the stirring time is 10 - 30 min.

[0024] Preferably, in step S2, the stirring speed is 80 - 150 r / min and the stirring time is 10 - 30 min.

[0025] Preferably, in step S3, the stirring speed is 80 - 150 r / min, the stirring time is 10 - 30 min, and the curing time is 10 - 20 min.

[0026] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0027] The environmentally friendly washable solid pigment of the present invention uses PEG as the base, which can reduce the surface tension of water and increase the wettability of the pigment. Therefore, when the solid pigment is used by dipping in water, it can be fully dissolved, facilitating the movement of the brushstroke during painting. The synergistic effect can be produced when carrageenan, carboxymethyl starch and gum ghatti are added in specific dosage ratios, thereby improving the dispersibility and film-forming property of the pigment. At the same time, since all three are water-soluble components, when the pigment gets on the skin or fabric, the pigment film can be removed by rinsing with water. Therefore, the pigment in the present invention has good water solubility, is easy to spread after painting with water, has bright colors, stable performance, and is easy to be cleaned on the skin and fabric. Description of the Drawings

[0028] Figure 1 It is a physical diagram of the solid pigment of the present invention. Detailed Embodiments

[0029] To better illustrate the purpose, technical solution and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments.

[0030] The sources of the reagents used in the following examples and comparative examples are as follows:

[0031] PEG: PEG4000, PEG6000, and PEG8000 are all purchased from Liaoning Xindun Pharmaceutical and Chemical Co., Ltd.; Potassium lauryl phosphate: The manufacturer is Jiangsu Haian Petrochemical Factory, and the product number is MA24PK-50;

[0032] Sodium dodecylbenzenesulfonate: The manufacturer is Shanghai Aladdin Biochemical Technology Co., Ltd., and the product number is S108366;

[0033] Carrageenan: The manufacturer is Shanghai Yuanye Bio-Technology Co., Ltd., the product number is S30559, the purity is BR, and the strength is 1200;

[0034] Gum ghatti: The manufacturer is Shanghai Aladdin Biochemical Technology Co., Ltd., and the product number is G 120958;

[0035] Carboxymethyl starch: The manufacturer is Shanghai Aladdin Biochemical Technology Co., Ltd., and the product number is C804711;

[0036] Aluminum oxide: The manufacturer is Hangzhou Hengna New Materials Co., Ltd., the product number is ZH-Alum80, and the average particle size is 20 nm;

[0037] Magnesium oxide: The manufacturer is Zhejiang Asia-America Nano-Tech Co., Ltd., the product number is LT-MgO-001, and the particle size is 30 - 50 nm.

[0038] Other materials, reagents, etc. used in the examples and comparative examples can be obtained from commercial channels without special instructions.

[0039] Example 1

[0040] An environmentally friendly washable solid pigment, characterized in that it is made of the following raw materials in parts by weight:

[0041] 55 parts of PEG, 3 parts of stabilizer, 3 parts of washable film-forming agent, 20.9 parts of filler, 1 part of color powder, 0.25 part of preservative, and 10 parts of water, wherein the average molecular weight of the PEG is 6000, the stabilizer is a composition of potassium lauryl phosphate and sodium dodecylbenzenesulfonate with a mass ratio of 1:1.2, the washable film-forming agent is a composition of carrageenan, gum ghatti, and carboxymethyl starch with a mass ratio of 1:1:1, the filler includes the following components in parts by weight: 7 parts of aluminum oxide, 5.2 parts of magnesium oxide, 4 parts of heavy calcium, 4.7 parts of kaolin, the color powder is iron red, and the preservative is 2-methyl-4-isothiazolin-3-one.

[0042] Preparation method of environmentally friendly washable solid pigment, characterized by comprising the following steps:

[0043] S1. Mix PEG and 2 / 3 of the water, heat at 85 °C and stir at a speed of 300 r / min for 25 min until the PEG is completely dissolved. After cooling to 55 °C, add alumina, magnesia and washable film-forming agent, and stir at a speed of 300 r / min for 15 min to obtain a base slurry;

[0044] S2. Mix the stabilizer and the remaining water, then add color powder, heavy calcium carbonate and kaolin, and stir at a stirring speed of 100 r / min for 20 min to obtain a color slurry;

[0045] S3. Mix the base slurry and the color slurry, and stir at a speed of 100 r / min for 20 min. Then, cure the mixed slurry at 10 °C for 15 min to obtain the environmentally friendly washable solid pigment. As Figure 1 shown, the pigment of the present invention is in the form of semi-dry jelly.

[0046] Example 2

[0047] An environmentally friendly washable solid pigment, characterized by being made of the following raw materials in parts by weight:

[0048] 40 parts of PEG, 2 parts of stabilizer, 2 parts of washable film-forming agent, 15 parts of filler, 0.5 part of color powder, 0.2 part of preservative and 4.5 parts of water, wherein the average molecular weight of the PEG is 4000, the stabilizer is a composition of potassium lauryl phosphate and sodium dodecylbenzenesulfonate with a mass ratio of 1:0.5, the washable film-forming agent is a composition of carrageenan, gum ghatti and carboxymethyl starch with a mass ratio of 1:1:0.5, the filler includes the following components in parts by weight: 5 parts of alumina, 5 parts of magnesia, 2 parts of heavy calcium carbonate, 3 parts of kaolin, the color powder is orange, and the preservative is 2-methyl-5-chloro-4-isothiazolin-3-one.

[0049] Preparation method of environmentally friendly washable solid pigment, characterized by comprising the following steps:

[0050] S1. Mix PEG and half of the water, heat at 80 °C and stir at a speed of 200 r / min for 30 min until the PEG is completely dissolved. After cooling to 50 °C, add alumina, magnesia and washable film-forming agent, and stir at a speed of 200 r / min for 20 min to obtain a base slurry;

[0051] S2. Mix the stabilizer and the remaining water, then add color powder, heavy calcium carbonate and kaolin, and stir at a stirring speed of 80 r / min for 30 min to obtain a color slurry;

[0052] S3. Mix the base paste and the color paste, stir at a speed of 80 r / min for 30 min, and then cure the mixed paste at 8 °C for 20 min to obtain the environmentally friendly washable solid pigment.

[0053] Example 3

[0054] An environmentally friendly washable solid pigment, characterized in that it is made from the following raw materials by weight:

[0055] 60 parts of PEG, 4 parts of stabilizer, 4 parts of washable film-forming agent, 25 parts of filler, 1.5 parts of color powder, 0.3 part of preservative and 13.5 parts of water, wherein the average molecular weight of the PEG is 8000, the stabilizer is a composition of potassium lauryl phosphate and sodium dodecylbenzenesulfonate with a mass ratio of 1:1.5, the washable film-forming agent is a composition of carrageenan, gum ghatti and carboxymethyl starch with a mass ratio of 1:1:1.2, the filler includes the following components by weight: 8 parts of alumina, 6 parts of magnesia, 6 parts of heavy calcium carbonate, 5 parts of kaolin, the color powder is phthalocyanine green, and the preservative is 2-methyl-4-isothiazolin-3-one.

[0056] A preparation method of an environmentally friendly washable solid pigment, characterized by comprising the following steps:

[0057] S1. Mix PEG and 2 / 3 of the water, heat at 90 °C and stir at a speed of 400 r / min for 10 min until the PEG is completely dissolved, cool down to 60 °C, add alumina, magnesia and the washable film-forming agent, and stir at a speed of 400 r / min for 10 min to obtain the base paste;

[0058] S2. After mixing the stabilizer and the remaining water, add the color powder, heavy calcium carbonate and kaolin, and stir at a stirring speed of 150 r / min for 10 min to obtain the color paste;

[0059] S3. Mix the base paste and the color paste, stir at a speed of 150 r / min for 10 min, and then cure the mixed paste at 12 °C for 10 min to obtain the environmentally friendly washable solid pigment.

[0060] Example 4

[0061] The difference between Example 4 and Example 1 is that: the total amount of the washable film-forming agent remains unchanged, and the washable film-forming agent is a composition of carrageenan, gum ghatti and carboxymethyl starch with a mass ratio of 1:1:0.5.

[0062] Example 5

[0063] Example 5 is different from Example 1 in that: the total amount of the washable film-forming agent remains unchanged, and the washable film-forming agent is a composition of carrageenan, gum acacia, and carboxymethyl starch with a mass ratio of 1:1:0.8.

[0064] Example 6

[0065] Example 6 is different from Example 1 in that: the total amount of the washable film-forming agent remains unchanged, and the washable film-forming agent is a composition of carrageenan, gum acacia, and carboxymethyl starch with a mass ratio of 1:1:1.2.

[0066] Comparative Example 1

[0067] Comparative Example 1 is different from Example 1 in that: no stabilizer is added, and water is used to make up the difference.

[0068] Comparative Example 2

[0069] Comparative Example 2 is different from Example 1 in that: the total amount of the stabilizer remains unchanged, and the stabilizer is only potassium lauryl phosphate.

[0070] Comparative Example 3

[0071] Comparative Example 3 is different from Example 1 in that: the total amount of the stabilizer remains unchanged, and the stabilizer is only sodium dodecylbenzenesulfonate.

[0072] Comparative Example 4

[0073] Comparative Example 4 is different from Example 1 in that: the total amount of the washable film-forming agent remains unchanged, and the washable film-forming agent is a composition of carrageenan, gum acacia, and carboxymethyl starch with a mass ratio of 1:1:0.4.

[0074] Comparative Example 5

[0075] Comparative Example 5 is different from Example 1 in that: the total amount of the washable film-forming agent remains unchanged, and the washable film-forming agent is a composition of carrageenan, gum acacia, and carboxymethyl starch with a mass ratio of 1:1:1.3.

[0076] Comparative Example 6

[0077] Comparative Example 6 is different from Example 1 in that: the addition amount of the filler remains unchanged, alumina and magnesia are not added, and heavy calcium carbonate and kaolin are used to make up the difference according to a mass ratio of 4:4.7.

[0078] Comparative Example 7

[0079] Comparative Example 7 is different from Example 1 in that: the addition amount of the filler remains unchanged, alumina is not added, and heavy calcium carbonate and kaolin are used to make up the difference according to a mass ratio of 4:4.7.

[0080] Comparative Example 8

[0081] The difference between Comparative Example 8 and Example 1 is that the addition amount of the filler remains unchanged, magnesium oxide is not added, and heavy calcium carbonate and kaolin are used to make up the difference according to a mass ratio of 4:4.7.

[0082] Comparative Example 9

[0083] The difference between Comparative Example 9 and Example 1 is that aluminum oxide and magnesium oxide are not added in step S1 of the pigment preparation method, but in step S2, aluminum oxide and magnesium oxide are mixed together with heavy calcium carbonate and kaolin.

[0084] Performance Test

[0085] 1. Skin washability: Divide the two arms of 5 subjects into detection areas respectively. Dip an equal amount (0.5 g) of the pigments of Examples 1-6 and Comparative Examples 1-9 and draw a 5-cm straight line on the arm areas. To ensure the same brush strokes, use the same type of silicone brush for application. After application, blow dry with a hair dryer at a temperature of 60 °C for 15 min until the pigment is completely dry. Then rinse with clean water for 2 minutes, observe the detection areas, and score the pigments in each area according to Table 1. The higher the score, the better the washability effect. Take the average score of the five people, and record the score in Table 2.

[0086] 2. Textile washability: Designate the detection areas on a pure white cotton T-shirt. Use a silicone brush to apply 1 g of the pigments of Examples 1-6 and Comparative Examples 1-9 to the detection areas respectively, and place them in a drying oven at 80 °C for 30 min. After taking out the T-shirt, soak it in clean water for 10 min, take it out and let the cotton T-shirt dry. Observe the detection areas, and score the pigments in each area according to Table 1. The higher the score, the better the washability effect. Take the average score of the five people, and record the score in Table 2.

[0087] Table 1 Washability Evaluation Table

[0088]

[0089] 3. Pigment stability test: Put the pigments of Examples 1-6 and Comparative Examples 1-9 into two iron boxes respectively. Each box contains no less than 15 g of pigment. Exclude air bubbles, seal with glass paper and mark, and then cover the iron box. Put the iron boxes into a self-controlled constant temperature oven at 75-80 °C and a freezer at -15 to -20 °C for 72 hours, and then take them out and store them at room temperature. For the pigments stored at room temperature for more than 3 hours, measure the fluidity and compare the fluidity with the ink that has not undergone heating and freezing tests. See Table 2 for details.

[0090] 4. Safety test: Conduct a cytotoxicity test on the pigment of Example 1, specifically as follows:

[0091] Take the immortalized human epidermal cell line (HaCaT) with stable growth state, adjust the cell concentration to 1×105 / mL, and inoculate 100 μL per well into a 96-well cell culture plate (except for the outermost wells and blank control wells). Add 200 μL of PBS to the outermost wells of the cell culture plate to reduce the evaporation of the culture medium. Place it in a carbon dioxide incubator and culture it at 37°C ± 1°C and a CO2 concentration of 5.0% ± 1% until the cell fusion reaches more than 90%. Add the sample with a concentration of 10 mg / L, set up a blank control and a sample group, 100 μL per well. Start timing when adding the sample of Example 1 (sample group) and PBS (blank control), keep the time interval of adding samples in each two columns consistent, ensure that the intervention time of each test substance on the cells is 5 min. After 5 min, aspirate the test substances in turn, add PBS to each well to wash the test substances, and wash 2 times. When using a vacuum liquid suction pump or a multi-channel pipette to aspirate the liquid in the wells, operate carefully to avoid aspirating the surviving cells and affecting the experimental results. Add 100 μL of complete culture medium and 10 μL of CCK-8 solution to each well respectively, and place it in the incubator for about 2 h. Measure the absorbance (OD) value at a wavelength of 450 nm and calculate the cell viability, as shown in Equation (1) specifically, and the results are shown in Table 3.

[0092]

[0093] Table 2 Washability and stability data of pigments in each group

[0094]

[0095] Table 3 Pigment cytotoxicity test of Example 1

[0096] Experimental group Survival rate of HaCaT (%) Example 1 97.6 Blank control group 100

[0097] As can be seen from Table 2, Examples 1, 4 - 6 and Comparative Examples 4 - 5 are to explore the influence of the mass ratio of carrageenan, gum ghatti and carboxymethyl starch on the performance of the pigment. Among them, the washability of the pigments in Examples 1, 4 - 6 is better than that in Comparative Examples 4 - 5, indicating that the washable film-forming agent includes a composition of carrageenan, gum ghatti and carboxymethyl starch with a mass ratio of 1∶1∶(0.5 - 1.2). Within this ratio range, the pigment can obtain better washability. If the addition amount of carboxymethyl starch is too much (such as Comparative Example 5), the pigment will be too thick and difficult to be evenly applied, and precipitation and stratification phenomena also occur at high and low temperatures, thus reducing the stability of the pigment. If the addition amount of carboxymethyl starch is too little (such as Comparative Example 4), the consistency of the watercolor pigment is not enough to meet the painting requirements, resulting in the pigment being easy to flow and spread and difficult to control, so that carboxymethyl starch may not fully play its thickening and stabilizing properties, and the performance improvement of carrageenan and gum ghatti is limited. As Figure 1 shown, the pigment of the present invention is semi-dry jelly-like.

[0098] Example 1 and Comparative Examples 1-3 were used to explore the effects of potassium lauryl phosphate and sodium dodecylbenzenesulfonate in the stabilizer on the properties of the pigment. From the data in Table 2, it can be seen that potassium lauryl phosphate and sodium dodecylbenzenesulfonate have a synergistic effect, which can better improve the stability of the pigment and also improve the washability of the pigment on the skin and fabrics.

[0099] Example 1 and Comparative Examples 6-8 were used to explore the effects of alumina and magnesia on the properties of the pigment. From the data in Table 2, it can be seen that there is a synergistic effect among alumina, magnesia, heavy calcium carbonate, and kaolin, which can better improve the stability of the pigment and also improve the washability of the pigment on the skin and fabrics. This may be because when alumina and alumina are mixed with PEG, they will fill the voids between PEG molecules, thereby reducing the free volume between PEG molecules. This physical filling effect will limit the movement space of the PEG molecular chain, thereby reducing the crystallization tendency of PEG.

[0100] Example 1 and Comparative Example 9 were used to explore the effect of the feeding sequence of alumina and magnesia on the properties of the pigment. From the data in Table 2, it can be seen that when preparing the pigment, alumina and magnesia need to be mixed with PEG first, and then mixed with other raw materials to obtain a pigment with good stability and washability.

[0101] As can be seen from Table 3, the cell survival rate of Example 1 was 97.6%, indicating that the pigment of Example 1 has a relatively small impact on cell viability, that is, it has good safety.

[0102] In summary, the pigment of the present invention has good water solubility, is easy to spread after dipping in water for painting, has bright colors, stable performance, and good water solubility, and is easy to clean on the skin and fabrics.

[0103] Finally, it should be noted that the above examples are only used to illustrate the technical solutions of the present invention rather than to limit the protection scope of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. An environmentally friendly washable solid pigment, characterized in that: The invention comprises the following raw materials in parts by weight: 40-60 parts of PEG, 2-4 parts of stabilizer, 2-4 parts of washable film-forming agent, 15-25 parts of filler, 0.5-1.5 parts of color powder and 4.5-13.5 parts of water, wherein the average molecular weight of the PEG is 6000-8000, the stabilizer comprises potassium lauryl phosphate and sodium dodecylbenzene sulfonate, the washable film-forming agent comprises carrageenan, ghatti gum and carboxymethyl starch in a mass ratio of 1:1:(0.5-1.2), and the filler comprises aluminum oxide, magnesium oxide, heavy calcium and kaolin; The environmentally friendly water-washable solid pigment is prepared by the following steps: S1. Mix PEG and part of water, heat and stir at 80-90°C until PEG is completely dissolved, cool to 50-60°C, add aluminum oxide, magnesium oxide and washable film-forming agent, stir evenly, and obtain base slurry; S2, after mixing the stabilizer and the remaining water, add the color powder, heavy calcium and kaolin, and stir to obtain a color paste; S3, mixing the base slurry and the color slurry, stirring evenly, and curing the mixed slurry at 8-12° C. to obtain the environmentally friendly water-washable solid pigment.

2. The environmentally friendly water-washable solid pigment according to claim 1, characterized in that: The filler comprises the following components in parts by weight: 5-8 parts of aluminum oxide, 5-6 parts of magnesium oxide, 2-6 parts of heavy calcium oxide, and 3-5 parts of kaolin.

3. The environmentally friendly water-washable solid pigment according to claim 1, characterized in that: The color powder includes at least one of titanium white, carbon black, phthalocyanine blue, phthalocyanine green, fast yellow, fast red, iron red, iron yellow, orange yellow, benzidine yellow, ruby, silver beads, ultramarine, permanent purple, permanent pink, rose color source, and permanent orange.

4. The environmentally friendly water-washable solid pigment according to claim 1, characterized in that: The pigment also includes 0.2-0.3 parts of preservatives.

5. The environmentally friendly water-washable solid pigment according to claim 4, characterized in that: The preservative is 2-methyl-4-isothiazoline-3-one and / or 2-methyl-5-chloro-4-isothiazoline-3-one.

6. The environmentally friendly water-washable solid pigment as claimed in claim 1 or 4, characterized in that: The mass ratio of the potassium lauryl phosphate to sodium dodecylbenzene sulfonate is 1:(0.5-1.5).

7. The environmentally friendly water-washable solid pigment as claimed in claim 1 or 4, characterized in that: The washable film-forming agent is a composition of carrageenan, gum ghatti and carboxymethyl starch in a mass ratio of 1:1:(1-1.2).

8. A method for preparing an environmentally friendly water-washable solid pigment according to any one of claims 1 to 7, characterized in that: The following steps are involved: S1. Mix PEG and part of water, heat and stir at 80-90°C until PEG is completely dissolved, cool to 50-60°C, add aluminum oxide, magnesium oxide and washable film-forming agent, stir evenly, and obtain base slurry; S2, after mixing the stabilizer and the remaining water, add the color powder, heavy calcium and kaolin, and stir to obtain a color paste; S3, mixing the base slurry and the color slurry, stirring evenly, and curing the mixed slurry at 8-12° C. to obtain the environmentally friendly water-washable solid pigment.

9. The method for preparing the environmentally friendly water-washable solid pigment according to claim 8, characterized in that: In step S1, the stirring speed is 200-400 r / min, and the stirring time is 10-30 min.

10. The method for preparing the environmentally friendly water-washable solid pigment according to claim 8, characterized in that: In step S2, the stirring speed is 80-150 r / min, and the stirring time is 10-30 min.

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