Pigment compositions, methods of making and using same

Abstract

The application discloses a pigment composition and a preparation method and application thereof, and relates to the technical field of pigments.The pigment composition comprises a pearl pigment substrate, a laser-sensitive layer and a toning layer which are sequentially coated on the surface of the pearl pigment substrate.The material of the laser-sensitive layer comprises Prussian blue and graphene.The Prussian blue is coated on the surface of the pearl pigment substrate, and the pearl pigment can be used as laser powder by taking the Prussian blue as the laser-sensitive layer.Further, the graphene is arranged in the laser-sensitive layer as a heat-conducting material, the surface heat conduction effect of the pigment is improved, and the laser marking effect is enhanced.The toning layer can improve the overall hiding power of the pigment.The pearl pigment is used as a base material to prepare the pigment composition with the laser-sensitive function, the pigment composition can be used as laser powder, and the lines and characters formed by laser marking have good gloss.

Description

Technical Field

[0001] The present invention relates to the technical field of pigments, and in particular to a pigment composition and a preparation method and application thereof. Background Art

[0002] The main function of laser powder is to absorb laser energy and convert it into heat, which heats the plastic, causing carbonization, evaporation, and chemical reactions. Different laser marking methods are available for plastics with different chemical properties, resulting in light-colored laser marks on dark backgrounds and dark-colored laser marks on light backgrounds. Therefore, laser powder is a special substance that must be added to plastic products when laser marking is unclear or impossible. It changes color under the influence of the laser, creating a sharp contrast and ensuring a clear, beautiful, and wear-resistant mark without affecting the color or performance of the plastic product. Laser powder can be mixed with a variety of plastics, resulting in a clear, bright laser mark. It can produce both black and white markings and is suitable for injection molding, extrusion, spraying, painting, and other applications.

[0003] Most of the existing materials that can be used for laser marking are inorganic metal materials. Although they can mark the text or pattern to be printed, their glossiness is low and they are difficult to identify.

[0004] In view of this, the present invention is proposed. Summary of the Invention

[0005] The purpose of the present invention is to provide a pigment composition and a preparation method and application thereof.

[0006] The present invention is achieved in that:

[0007] In a first aspect, the present invention provides a pigment composition comprising a pearlescent pigment matrix and a laser-sensitive layer and a color-adjusting layer sequentially coated on the surface thereof.

[0008] Materials for the laser-sensitive layer include Prussian blue and graphene.

[0009] In an optional embodiment, the thickness of the laser sensitive layer is 5-20 nm.

[0010] In an optional embodiment, the pearlescent pigment matrix is ​​a masterbatch with an interference color and a surface-coated pigment; preferably, the masterbatch is a masterbatch with an interference color and a surface-coated titanium dioxide.

[0011] Preferably, the pearlescent pigment matrix is ​​in the shape of flakes.

[0012] In an alternative embodiment, the material of the toning layer includes titanium dioxide or iron oxide.

[0013] In a second aspect, the present application provides a method for preparing the pigment composition according to any one of the preceding embodiments, comprising coating the nacreous pigment substrate with an aqueous solution to form a laser-sensitive layer, and then kneading the dried coated solid with the material of the toning layer.

[0014] In an optional embodiment, the coating with the aqueous solution to form the laser-sensitive layer comprises placing the nacreous pigment substrate in water and adding a first solution.

[0015] The first solution comprises a ferric trichloride solution containing graphene and a sodium ferrocyanide solution.

[0016] In an optional embodiment, the ferric trichloride solution containing graphene has a concentration of ferric oxide of 40-60 g / L and a content of graphene of 0.5-2%.

[0017] Preferably, the sodium ferrocyanide solution has a concentration of 8-15%.

[0018] Preferably, the ferric trichloride solution containing graphene is stirred for 5-15 min before the sodium ferrocyanide solution is added.

[0019] Preferably, the volumes of water, ferric trichloride solution containing graphene and sodium ferrocyanide solution added per 100 g of nacreous pigment substrate are 1.5-2.5 L, 10-20 ml and 12-30 ml, respectively.

[0020] In an optional embodiment, the method further comprises heating the water containing the nacreous pigment substrate and adjusting the pH of the solution before adding the first solution.

[0021] Preferably, the water containing the nacreous pigment substrate is heated to a temperature of 45-55°C and the pH is adjusted to 4.0-5.0.

[0022] In an optional embodiment, the kneading further comprises wetting the solid with an organic solvent before the kneading; preferably, the organic solvent comprises ethanol or acetone.

[0023] Preferably, the kneading is performed for 20-40 min.

[0024] Preferably, the mass ratio of the nacreous pigment substrate to the material of the toning layer is 100:0.5-3.

[0025] Preferably, the method further comprises drying and sieving the solid obtained after the kneading; preferably, the mesh size of the sieve is 300-400 mesh.

[0026] In a third aspect, the present application provides the use of the pigment composition according to any one of the preceding embodiments or prepared by the method according to any one of the preceding embodiments in a laser marking material.

[0027] The present application has the following advantages:

[0028] The present invention provides a pigment composition, preparation method, and application thereof. By coating the surface of a pearlescent pigment substrate with Prussian blue, which serves as a laser-sensitive layer, the pearlescent pigment can be used as a laser powder. Furthermore, by incorporating graphene as a thermally conductive material within the laser-sensitive layer, the surface heat conduction of the pigment is enhanced, thereby enhancing the laser marking effect. The coloring layer improves the overall hiding power of the pigment. The present invention utilizes pearlescent pigment as a substrate and improves the pigment composition to produce laser-sensitive pigments. This pigment composition can be used as a laser powder, and the textures and text formed by laser marking have good gloss. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0030] Figure 1 This is a scanning electron microscope image of the pigment composition provided in Example 1 of the present invention;

[0031] Figure 2 This is a picture obtained after the pigment composition provided in Example 1 of the present invention is used for laser coding;

[0032] Figure 3 This is a picture obtained after the pigment composition provided in Comparative Example 1 of the present invention is used for laser coding. DETAILED DESCRIPTION

[0033] To make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention are described clearly and completely below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer are used. Where the manufacturer of the reagents or instruments is not specified, all are conventional products that can be purchased commercially.

[0034] The features and performance of the present invention are further described in detail below with reference to the embodiments.

[0035] In a first aspect, the present invention provides a pigment composition comprising a pearlescent pigment matrix and a laser-sensitive layer and a color-adjusting layer sequentially coated on the surface thereof.

[0036] Materials for the laser-sensitive layer include Prussian blue and graphene.

[0037] The main function of laser powder is to absorb laser energy and convert the laser beam into heat energy, which produces heating, carbonization, evaporation and chemical reactions on plastics. Existing laser powders are mostly inorganic metal materials. Although they can mark the text or pattern to be printed, their glossiness is low and difficult to identify. Through long-term research, the applicant coated Prussian blue on the surface of the pearlescent pigment matrix, which serves as a laser sensitive layer, making it possible for pearlescent pigments to be used as laser powders. Furthermore, by arranging graphene as a heat-conducting material in the laser sensitive layer, the surface heat conduction effect of the pigment is improved, and the laser marking effect is enhanced. The coloring layer can improve the overall hiding power of the pigment. The present invention uses pearlescent pigments as a base material for improvement to prepare a pigment composition with laser sensitivity, which can be used as laser powder. The lines and words formed by laser marking have good gloss.

[0038] In an optional embodiment, the thickness of the laser sensitive layer is 5 to 20 nm. By setting the thickness within the above range, the laser marking obtained during laser printing can have both laser and pearlescent effects.

[0039] In an optional embodiment, the pearlescent pigment matrix is ​​a masterbatch with an interference color and a surface-coated pigment; preferably, the masterbatch is a masterbatch with an interference color and a surface-coated titanium dioxide.

[0040] Preferably, the pearlescent pigment matrix is ​​flaky. For example, a layer of titanium dioxide is coated on the surface of flaky mica to serve as the pearlescent pigment matrix. In other embodiments, other pigments may be coated, or the coating may be applied to other materials having interference colors instead of the mica surface.

[0041] In an optional embodiment, the material of the tinting layer includes titanium dioxide or iron oxide. The tinting layer is mainly used to enhance the overall hiding power of the pigment. Therefore, in other embodiments, the material of the tinting layer can also be any other commercially available pigment as long as it can enhance the overall hiding power of the pigment.

[0042] In a second aspect, the present invention provides a method for preparing the pigment composition according to any one of the aforementioned embodiments, the specific steps being as follows:

[0043] S01. Encapsulating the pearlescent pigment matrix with water to form a laser-sensitive layer.

[0044] In an optional embodiment, forming the laser-sensitive layer by aqueous coating includes placing the pearlescent pigment matrix in water and adding the first solution to react.

[0045] The first solution includes a ferric chloride solution and a sodium ferrocyanide solution containing graphene. The pearlescent pigment substrate is immersed in the first solution, where the ferric chloride and sodium ferrocyanide react to form Prussian blue. The resulting Prussian blue precipitates in the solution and can directly coat the surface of the pearlescent pigment substrate. Since Prussian blue is laser-sensitive, it forms a laser-sensitive layer on the surface of the pearlescent pigment substrate. The first solution also contains graphene, which has excellent thermal conductivity, promoting heat conduction on the pigment surface and enhancing the laser marking effect.

[0046] Preferably, in order to ensure that the prepared pigment composition is pure and free of impurities, the water is any one of soft water, deionized water or pure water.

[0047] In an optional embodiment, the concentration of iron oxide in the ferric chloride solution containing graphene is 40-60 g / L, for example, 40 g / L, 42 g / L, 44 g / L, 46 g / L, 48 g / L, 50 g / L, 52 g / L, 54 g / L, 56 g / L, 58 g / L, and 60 g / L. The content of graphene is 0.5-2%, for example, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1.0%, 1.1%, 1.2%, 1.3%, 1.4%, 1.5%, 1.6%, 1.7%, 1.8%, 1.9%, and 2.0%.

[0048] Preferably, the concentration of sodium ferrocyanide is 8-15%, for example, 8%, 9%, 10%, 11%, 12%, 13%, 14% or 15%.

[0049] Preferably, to ensure that Prussian blue is evenly coated on the surface of the pearlescent pigment matrix, a ferric chloride solution containing graphene is added to water and stirred for 5 to 15 minutes before adding the sodium ferrocyanide solution. This ensures that the ferric chloride solution containing graphene is evenly dispersed on the surface of the pearlescent pigment matrix, allowing the sodium ferrocyanide solution to react directly on the surface of the pearlescent pigment matrix to produce Prussian blue.

[0050] Preferably, to ensure that the obtained laser sensitive layer has an appropriate thickness, the volumes of water, graphene-containing ferric chloride solution, and sodium ferrocyanide solution added per 100 g of pearlescent pigment matrix are 1.5-2.5 L, 10-20 ml, and 12-30 ml, respectively.

[0051] In an optional embodiment, the method further comprises heating the water containing the pearlescent pigment matrix and adjusting the pH value of the solution before adding the first solution.

[0052] Preferably, the temperature of the water containing the pearlescent pigment matrix after heating is 45-55° C., for example, 45° C., 47° C., 49° C., 51° C., 53° C., or 55° C. The pH is 4.0-5.0, for example, 4.0, 4.2, 4.4, 4.6, 4.8, or 5.0.

[0053] S02. Dry the solid coated in step S01 and then add the materials of the toning layer and knead.

[0054] In an optional embodiment, the kneading further comprises wetting the solid with an organic solvent before kneading; preferably, the organic solvent comprises ethanol or acetone.

[0055] Preferably, the kneading time is 20 to 40 min, for example, 20 min, 22 min, 24 min, 26 min, 28 min, 30 min, 32 min, 34 min, 36 min, 38 min or 40 min.

[0056] Preferably, the mass ratio of the pearlescent pigment matrix to the material of the toning layer is 100:0.5-3.

[0057] Preferably, the method further comprises drying and sieving the solid obtained after kneading; preferably, the mesh number of the sieve is 300 to 400 meshes.

[0058] In a third aspect, the present invention provides a use of a pigment composition according to any one of the aforementioned embodiments or a pigment composition prepared by the preparation method according to any one of the aforementioned embodiments in a laser marking material.

[0059] Example 1

[0060] This embodiment provides a pigment composition, and the preparation method thereof is as follows:

[0061] S01. Place 100 g of flaky particles coated with titanium dioxide and exhibiting interference colors in 2 L of soft water, heat to 50°C, and adjust the water's pH to 4.0-5.0. Add 15 mL of a graphene-containing ferric chloride solution, where the iron oxide concentration is 50 g / L and the graphene content is 1%. Stir the graphene-containing ferric chloride solution for 10 minutes before adding 25 mL of a sodium ferrocyanide solution. The sodium ferrocyanide solution is slowly added dropwise until the reaction with the ferric chloride is complete and Prussian blue forms on the surface of the flaky particles. Filter the reaction liquid to separate the solid, which is then dried for later use. The thickness of the laser-sensitive layer on the solid is 10 nm.

[0062] S02. Take 100 g of the coated solid after step S01 and place it in a kneader. After adding ethanol to moisten it, add 1 g of organically treated pigment-grade titanium dioxide (commercially available) and knead it for 30 minutes. After kneading, dry and sieve it with a mesh size of 325 to obtain a pigment composition.

[0063] The pigment composition prepared in this example was placed under a scanning electron microscope for observation, and the following Figure 1 The results shown by Figure 1 It can be seen that the layers of the pigment composition prepared in the embodiment of the present invention are tightly connected, and the connections between the layers are smooth.

[0064] Example 2

[0065] This embodiment provides a pigment composition, and the preparation method thereof is as follows:

[0066] S01. Place 100 g of titanium dioxide-coated flaky particles with interference colors in 2 L of soft water, heat to 50°C, and adjust the water's pH to 4.0-5.0. Add 10 mL of a graphene-containing ferric chloride solution, where the iron oxide concentration is 50 g / L and the graphene content is 1%. After adding the graphene-containing ferric chloride solution, stir for 8 minutes before adding 15 mL of a sodium ferrocyanide solution. The sodium ferrocyanide solution is slowly added dropwise until the reaction with the ferric chloride is complete and Prussian blue forms on the surface of the flaky particles. The reacted liquid is then filtered to separate the solid, which is then dried for later use. The thickness of the solid laser-sensitive layer is 6 nm.

[0067] S02. Take 100 g of the coated solid after step S01 and place it in a kneader. After adding ethanol to moisten it, add 0.5 g of organically treated pigment-grade titanium dioxide and knead it for 30 minutes. After kneading, dry and sieve it with a mesh size of 325 to obtain a pigment composition.

[0068] Example 3

[0069] This embodiment provides a pigment composition, and the preparation method thereof is as follows:

[0070] S01, 100 g of the coated titanium dioxide with interference color flaky particles were placed in 2 L soft water, heated to 50 °C, the pH of the water was adjusted to 4.0-5.0, 10 mL of graphene-containing ferric chloride solution was added to the water, wherein the concentration of iron oxide was 50 g / L, and the content of graphene was 1%. After adding the graphene-containing ferric chloride solution, stirring for 8 min, then adding 15 ml of sodium ferrocyanide solution, the sodium ferrocyanide solution was added by slow dripping, and the dripping was stopped when the Prussian blue was formed on the surface of the flaky particles. Then the reacted liquid was filtered, the solid was separated, and the solid was dried for standby. The thickness of the laser sensitive layer of the solid was 6 nm.

[0071] S02, 100 g of the coated solid in step S01 was placed in a kneader, wetted with ethanol, then 0.5 g of organic-treated pigment-grade titanium dioxide was added and kneaded for 30 min. After kneading, drying and sieving were carried out, the mesh size of the sieve was 325 mesh, and a pigment composition was prepared.

[0072] Comparative Example 1

[0073] This comparative example provides a pigment composition, the preparation method of which is similar to that of Example 1, the only difference being that no graphene is added.

[0074] Comparative Example 2

[0075] This comparative example provides a pigment composition, the preparation method of which is similar to that of Example 1, the only difference being that the Prussian blue is directly blended and kneaded with the flaky substrate.

[0076] Comparative Example 3

[0077] This comparative example provides a pigment composition, the preparation method of which is similar to that of Example 1, the only difference being that the thickness of the laser sensitive layer is 30 nm.

[0078] Test Example 1

[0079] The pigment compositions prepared in Examples 1-2 and Comparative Examples 1-3 were tested for performance, and the testing method was as follows: the pigment composition was added to PP, processed into pigment color masterbatch, and then made into a plastic sheet with a pigment content of 4%, and a laser coding device was used for testing. The results are shown in Table 1 and Figures 2 and 3 .

[0080] Table 1 Performance of the pigment composition

[0081]

[0082]

[0083] As can be seen from Table 1, the pigment prepared in the embodiment of the present invention has good pearlescent effect and laser recognition function. Figure 2 and Figure 3 As shown, Figure 2 The pigment composition prepared in Example 1 of the present invention has a clearer laser recognition effect and a better pearlescent effect when used for laser coding. Figure 3 The pigment composition prepared in Comparative Example 1 has a fuzzy laser recognition effect when used for laser coding, irregular ghosting occurs around the font, and the pearlescent effect is poor.

[0084] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A pigment composition, characterized in that It includes a pearlescent pigment matrix and a laser sensitive layer and a color adjustment layer sequentially coated on its surface; The materials of the laser sensitive layer include Prussian blue and graphene; The thickness of the laser sensitive layer is 5 to 20 nm; The preparation method of the pigment composition comprises: coating the pearlescent pigment matrix with water to form a laser sensitive layer, drying the coated solid, and then adding the material of the color-adjusting layer and kneading; The aqueous coating to form the laser-sensitive layer comprises placing the pearlescent pigment matrix in water and adding a first solution for reaction; The first solution includes a ferric chloride solution containing graphene and a sodium ferrocyanide solution; and after adding the ferric chloride solution containing graphene, stirring for 5 to 15 minutes and then adding the sodium ferrocyanide solution.

2. The pigment composition according to claim 1, characterized in that The pearlescent pigment matrix is ​​a masterbatch with interference color and pigment coated on the surface.

3. The pigment composition according to claim 1, characterized in that The pearlescent pigment matrix is ​​a masterbatch with interference color and the surface is coated with titanium dioxide.

4. The pigment composition according to claim 2 or 3, characterized in that The pearlescent pigment matrix is ​​in the shape of a flake.

5. The pigment composition according to claim 1, characterized in that The material of the color adjustment layer includes any one of titanium dioxide and iron oxide.

6. A method for preparing the pigment composition according to any one of claims 1 to 5, characterized in that: The method comprises the steps of coating the pearlescent pigment matrix with water to form a laser sensitive layer, drying the coated solid, and then adding the material of the toning layer and kneading the mixture; The aqueous coating to form the laser-sensitive layer comprises placing the pearlescent pigment matrix in water and adding a first solution for reaction; The first solution includes a ferric chloride solution containing graphene and a sodium ferrocyanide solution, and the ferric chloride solution containing graphene is added and stirred for 5 to 15 minutes before adding the sodium ferrocyanide solution.

7. The preparation method according to claim 6, characterized in that The content of graphene in the ferric chloride solution containing graphene is 0.5-2%.

8. The preparation method according to claim 6, characterized in that The concentration of the sodium ferrocyanide is 8-15%.

9. The preparation method according to claim 6, characterized in that The volumes of water, ferric chloride solution containing graphene, and sodium ferrocyanide solution added per 100 g of the pearlescent pigment matrix are 1.5-2.5 L, 10-20 ml, and 12-30 ml, respectively.

10. The preparation method according to claim 6, characterized in that Before adding the first solution, the method further includes heating the water containing the pearlescent pigment matrix and adjusting the pH value of the solution.

11. The preparation method according to claim 10, characterized in that: The temperature of the water containing the pearlescent pigment matrix after heating is 45-55° C., and the pH value is 4.0-5.

0.

12. The preparation method according to claim 6, characterized in that Kneading also includes wetting the solid with an organic solvent and then kneading.

13. The preparation method according to claim 12, characterized in that The organic solvent includes any one of ethanol and propanol.

14. The preparation method according to claim 12, characterized in that The kneading time is 20 to 40 minutes.

15. The preparation method according to claim 12, characterized in that The mass ratio of the pearlescent pigment matrix to the material of the toning layer is 100:0.5-3.

16. The preparation method according to claim 12, characterized in that The process also includes drying and sieving the solid obtained after kneading; the mesh number of the sieve is 300-400 meshes.

17. Use of the pigment composition according to any one of claims 1 to 5 or the pigment composition prepared by the preparation method according to any one of claims 7 to 16 in laser marking materials.

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