A kind of high dispersibility phthalocyanine pigment and preparation method thereof

Abstract

The present invention belongs to the technical field of organic dyes, and specifically discloses a highly dispersible phthalocyanine pigment and a preparation method thereof. The preparation method of the phthalocyanine pigment comprises the following steps: (1) ultrasonically dispersing a silane coupling agent and graphene oxide in a solvent to prepare modified graphene oxide; (2) dispersing the modified graphene oxide, polyethylene glycol and copper phthalocyanine pigment in an organic solvent, and heating the reaction to obtain the highly dispersible phthalocyanine pigment. The organophilic groups in the long straight carbon chain silane coupling agent can be physically entangled with the copper phthalocyanine organic molecules, so that the interface between graphene oxide and copper phthalocyanine pigment is bonded, greatly improving the ability of graphene oxide to disperse copper phthalocyanine pigment. The polyethylene glycol molecular structure has multiple oxygen-containing anchoring functional groups, which can make up for the deficiencies of the modified graphene oxide dispersant, enhance the spatial repulsion between copper phthalocyanine pigment particles, and thus enhance the dispersion stability of the copper phthalocyanine pigment.

Description

Technical Field

[0001] The invention belongs to the technical field of organic dyes and specifically discloses a high-dispersibility phthalocyanine pigment and a preparation method thereof. Background Art

[0002] Organic pigments have strong coloring ability, bright colors, wide color spectrum, and high light fastness. Their application in textile printing and dyeing is increasingly valued. Copper phthalocyanine organic pigments have been achieved in large-scale industrial production and are widely used in industry. Organic pigments made from copper phthalocyanine are mainly blue and green, commonly known as phthalocyanine blue and phthalocyanine green. Copper phthalocyanine pigments have the advantages of bright colors, excellent performance, convenient manufacturing, and low price, making them one of the main categories of organic pigments. However, due to the strong hydrophobicity of copper phthalocyanine pigments, pigment dispersions are prone to form larger agglomerates during the manufacturing process, which will produce defects such as decreased coloring ability and unevenness of the color paste during the application process. Therefore, the preparation of stable pigment dispersions is the key to expanding the application of pigments.

[0003] In order to solve the problem that copper phthalocyanine organic pigments have poor wettability, are easy to form agglomerates and aggregates, and result in large particle size, various methods have been tried to modify copper phthalocyanine organic pigments to improve the dispersibility of the pigment in the medium, reduce its particle size, and enhance stability and color performance.

[0004] The addition of dispersants can reduce the interaction between particles and make it difficult for particles to aggregate. At the same time, dispersants can also change the surface properties of copper phthalocyanine pigments, such as potential and hydrophilicity, and improve the dispersibility and stability of copper phthalocyanine pigments. Suitable dispersants can simultaneously provide wetting, dispersing and stabilizing effects for copper phthalocyanine pigments, prevent flocculation and precipitation of copper phthalocyanine pigments, ensure that copper phthalocyanine pigments are always in a good dispersion state, and improve the tinting power of copper phthalocyanine pigments. According to the type of dispersant, it can be divided into small molecule and polymer dispersants. Conventional small molecule dispersants mainly achieve the purpose of stabilizing copper phthalocyanine pigments by adsorbing on the surface of copper phthalocyanine pigments to increase the electrostatic repulsion between pigment particles. However, under the influence of external factors (such as temperature, shear force or electrolytes, etc.), dispersant molecules are easily separated from the surface of copper phthalocyanine pigments, resulting in aggregation and precipitation of copper phthalocyanine pigments. The polymer dispersant is adsorbed on the surface of copper phthalocyanine pigment particles through functional group anchoring, which increases the electrostatic repulsion and steric hindrance between the copper phthalocyanine pigment particles, and enhances the adhesion ability through the binding points on the long chain, and has a strong stabilizing effect on the copper phthalocyanine pigment dispersion system.

[0005] Generally, the synthesis and preparation process of polymer dispersants requires complex processes and conditions, consumes a lot of energy and chemical reagents, and thus makes the preparation cost high. At the same time, harmful by-products may be produced during the chemical synthesis process, causing pollution and impact on the environment, and the polymer-modified copper phthalocyanine organic pigment has a large particle size, which inhibits its application in printing and dyeing, color lithography and other fields. Summary of the invention

[0006] In order to solve the technical problems of the prior art copper phthalocyanine organic pigments that are easy to agglomerate, have large particle size, and uneven particle size distribution, the present invention provides a highly dispersible phthalocyanine pigment and a preparation method thereof. The particle size of the copper phthalocyanine pigment is reduced by compounding a modified graphene oxide inorganic dispersant and a polyethylene glycol organic dispersant to improve its dispersibility.

[0007] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0008] A method for preparing a highly dispersible phthalocyanine pigment comprises the following steps:

[0009] (1) ultrasonically dispersing a silane coupling agent and graphene oxide in a solvent, heating for reaction, centrifuging, washing, and drying to obtain modified graphene oxide; the silane coupling agent has a structural formula of X-Si-Y3, X is a straight-chain alkyl group with a carbon number of 8-18, and Y is an alkoxy group with a carbon number of 1-4; the mass ratio of the silane coupling agent to the graphene oxide is (0.1-1):1;

[0010] (2) Dispersing modified graphene oxide, polyethylene glycol and copper phthalocyanine pigment in an organic solvent, stirring and reacting at 35-50°C for 2-4 hours, filtering, washing and drying to obtain a highly dispersed phthalocyanine pigment; the mass ratio of copper phthalocyanine pigment to modified graphene oxide and polyethylene glycol is 100:(2-6):(0.5-1).

[0011] There are two ways to combine graphene and phthalocyanine, covalent bonding and non-covalent bonding. The substituent of substituted phthalocyanine can be combined with graphene through covalent bonds, and the result is a covalently bonded complex, which can improve the dispersion performance of copper phthalocyanine to a certain extent; however, this technology requires a complex synthesis process, and more organic solvents need to be used during the reaction process, which is not only highly polluting, but also has low stability of the covalently bonded complex and limited particle size reduction. In order to solve this problem, the present invention selects graphene oxide as a modifier for copper phthalocyanine. Both graphene oxide and copper phthalocyanine molecules have two-dimensional planar structures with conjugated π electrons. Copper phthalocyanine molecules can be parallel to graphene oxide sheets to form π-π stacking, so that non-covalently bonded complexes are obtained, which prevents copper phthalocyanine pigments from agglomerating and reduces their particle size.

[0012] However, the single graphene oxide has more hydrophilic groups on the surface and has poor compatibility with copper phthalocyanine pigment. Therefore, the present invention uses a silane coupling agent with a long straight carbon chain to modify it, which reduces the surface polarity of graphene oxide and improves its compatibility with copper phthalocyanine organic pigment. The silane coupling agent with a long straight carbon chain is an organosilicon compound with a special structure. In its molecules, there are both reactive groups that can bind to graphene oxide and long carbon chain groups that bind to copper phthalocyanine organic pigment. The alkoxy inorganic affinity group can react with the hydroxyl or carboxyl group on the surface of graphene oxide to form a strong chemical bond; the long straight carbon chain organic affinity group can be physically entangled with the copper phthalocyanine organic molecule, so that the interface between graphene oxide and copper phthalocyanine pigment is bonded, greatly improving the ability of graphene oxide to disperse copper phthalocyanine pigment. In addition, the graphene oxide modified by the long straight carbon chain silane coupling agent has both hydrophilic graphene oxide ends and lipophilic long chain alkyl groups, and has the properties of an amphoteric surfactant, which further improves the dispersibility of the copper phthalocyanine pigment. However, the dispersion of copper phthalocyanine by modified graphene oxide still belongs to inorganic material modification, which mainly plays an effective dispersing and stabilizing role through the electrostatic repulsion mechanism, and has limited dispersing ability for organic pigments.

[0013] In order to further improve the dispersion effect of copper phthalocyanine pigment and reduce its particle size, the present invention adds polyethylene glycol polymer dispersant. Polyethylene glycol has multiple oxygen-containing anchoring functional groups on its molecular structure, which can simultaneously bind to the copper phthalocyanine pigment surface multi-site through ionic bonds, hydrogen bonds and van der Waals forces, forming a firm adsorption layer. Polyethylene glycol dispersant can make up for the deficiency of modified graphene oxide dispersant, enhance the spatial repulsion between copper phthalocyanine pigment particles, thereby enhancing the stability of copper phthalocyanine pigment. Therefore, using polyethylene glycol polymer dispersant and modified graphene oxide inorganic dispersant to modify copper phthalocyanine pigment can not only improve the dispersion stability of copper phthalocyanine pigment, but also realize the improvement of other multiple performances, which provides important support for the expansion of copper phthalocyanine pigment application field.

[0014] Further, in step (1), the silane coupling agent is at least one of octyltrimethoxysilane, octyltriethoxysilane, nonyltrimethoxysilane, nonyltriethoxysilane, decyltrimethoxysilane, decyltriethoxysilane, undecyltrimethoxysilane, undecyltriethoxysilane, dodecyltrimethoxysilane, dodecyltriethoxysilane, tridecyltrimethoxysilane, tridecyltriethoxysilane, tetradecyltrimethoxysilane, tetradecyltriethoxysilane, pentadecyltrimethoxysilane, pentadecyltriethoxysilane, hexadecyltrimethoxysilane, hexadecyltriethoxysilane, octadecyltrimethoxysilane, and octadecyltriethoxysilane. Further, the silane coupling agent is a combination of coupling agents with different chain lengths. By selecting long straight carbon chain silane coupling agents with different chain lengths, the entanglement effect of the long chain can be better exerted.

[0015] Furthermore, in step (1), the graphene oxide is a single-layer graphene oxide or a multi-layer graphene oxide. Furthermore, the graphene oxide is a single-layer graphene oxide. Compared with multi-layer graphene oxide, single-layer graphene oxide has a larger specific surface area and is more likely to form π-π stacking with copper phthalocyanine pigment to form a non-covalently bonded complex. On the other hand, single-layer graphene oxide has high light transmittance and mechanical strength, and has good chemical stability, so that the modified copper phthalocyanine pigment can be used in a variety of environments.

[0016] Furthermore, in step (1), the ultrasonic power is 100-200W.

[0017] Furthermore, the solvent in step (1) is a mixed solvent of deionized water and ethanol.

[0018] Furthermore, the heating reaction temperature in step (1) is 40-60°C.

[0019] Furthermore, the copper phthalocyanine pigment in step (2) is phthalocyanine blue. Furthermore, the phthalocyanine blue is at least one of CI Pigment Blue 15, CI Pigment Blue 15:1, CI Pigment Blue 15:2, CI Pigment Blue 15:3 (also known as Phthalocyanine Blue BGS), CI Pigment Blue 15:4, CI Pigment Blue 15:5, and CI Pigment Blue 15:6.

[0020] Furthermore, the organic solvent in step (2) is at least one of methanol, ethanol, propanol, propylene glycol, acetone, and nitrogen-methylpyrrolidone.

[0021] Furthermore, in step (2), the number average molecular weight of polyethylene glycol is 200-800. Specifically, the polyethylene glycol can be any one or more of PEG200, PEG400, PEG600, and PEG800.

[0022] On the other hand, the present invention also provides a highly dispersible phthalocyanine pigment. On the one hand, by utilizing the huge specific surface area of ​​modified graphene oxide and the heterogeneous effect between modified graphene oxide and phthalocyanine compounds, the long straight carbon chain organophilic groups can be physically entangled with the copper phthalocyanine organic molecules, so that the interface between graphene oxide and copper phthalocyanine pigment is bonded, reducing the molecular aggregation between phthalocyanine compounds; on the other hand, the polyethylene glycol molecular structure has multiple oxygen-containing anchoring functional groups, which can make up for the deficiencies of the modified graphene oxide dispersant and improve its dispersibility during the application process.

[0023] Beneficial effect: The present invention selects modified graphene oxide as a modifier for copper phthalocyanine. Both graphene oxide and copper phthalocyanine molecules have two-dimensional planar structures with conjugated π electrons. Copper phthalocyanine molecules can be parallel to graphene oxide sheets to form π-π stacking, so that a non-covalently bound complex is obtained, which prevents the copper phthalocyanine pigment from agglomerating and reduces its particle size. The organophilic groups in the long straight carbon chain silane coupling agent can be physically entangled with the copper phthalocyanine organic molecules, so that the interface between graphene oxide and copper phthalocyanine pigment is bonded, greatly improving the ability of graphene oxide to disperse copper phthalocyanine pigment. There are multiple oxygen-containing anchoring functional groups on the molecular structure of polyethylene glycol, which can simultaneously bind to the surface of copper phthalocyanine pigment at multiple sites through ionic bonds, hydrogen bonds, and van der Waals forces to form a strong adsorption layer, make up for the shortcomings of the modified graphene oxide dispersant, and enhance the spatial repulsion between copper phthalocyanine pigment particles, thereby enhancing the stability of copper phthalocyanine pigment. Therefore, the use of polyethylene glycol polymer dispersant and modified graphene oxide inorganic dispersant to modify copper phthalocyanine pigment can not only improve the dispersion stability of copper phthalocyanine pigment, but also achieve improvements in many other properties, providing important support for the expansion of the application field of copper phthalocyanine pigment. DETAILED DESCRIPTION

[0024] The present invention is described in detail below in conjunction with specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that, for those of ordinary skill in the art, several variations and improvements may be made without departing from the concept of the present invention. These all belong to the protection scope of the present invention.

[0025] Example 1

[0026] A method for preparing a highly dispersible phthalocyanine pigment comprises the following steps:

[0027] (1) Ultrasonic dispersion of silane coupling agent and graphene oxide in a solvent, heating for reaction, centrifugation, washing, and drying to obtain modified graphene oxide; the mass ratio of silane coupling agent to graphene oxide is 0.3:1; the silane coupling agent is a mixture of octyltrimethoxysilane and dodecyltrimethoxysilane in a molar ratio of 1:1; the graphene oxide is a single-layer graphene oxide; the ultrasonic power is 100 W; the solvent is a mixed solvent of deionized water and ethanol in a volume ratio of 1:1; the heating reaction temperature is 40°C, and the reaction time is 2 h;

[0028] (2) Dispersing modified graphene oxide, polyethylene glycol and copper phthalocyanine pigment in an organic solvent acetone, stirring and reacting at 35°C for 4 hours, filtering, washing and drying to obtain a highly dispersed phthalocyanine pigment; the mass ratio of copper phthalocyanine pigment to modified graphene oxide and polyethylene glycol is 100:2:0.5; the copper phthalocyanine pigment is phthalocyanine blue BGS; and the number average molecular weight of polyethylene glycol is 200.

[0029] Example 2

[0030] A method for preparing a highly dispersible phthalocyanine pigment comprises the following steps:

[0031] (1) Ultrasonic dispersion of silane coupling agent and graphene oxide in a solvent, heating for reaction, centrifugation, washing, and drying to obtain modified graphene oxide; the mass ratio of silane coupling agent to graphene oxide is 0.6:1; the silane coupling agent is a mixture of decyltrimethoxysilane and hexadecyltriethoxysilane in a molar ratio of 1:1; the graphene oxide is a single-layer graphene oxide; the ultrasonic power is 200 W; the solvent is a mixed solvent of deionized water and ethanol in a volume ratio of 1:1; the heating reaction temperature is 60°C, and the reaction time is 2 h;

[0032] (2) Dispersing modified graphene oxide, polyethylene glycol and copper phthalocyanine pigment in an organic solvent acetone, stirring and reacting at 50°C for 2 h, filtering, washing and drying to obtain a highly dispersed phthalocyanine pigment; the mass ratio of copper phthalocyanine pigment to modified graphene oxide and polyethylene glycol is 100:5:1; the copper phthalocyanine pigment is phthalocyanine blue BGS; and the number average molecular weight of polyethylene glycol is 800.

[0033] Example 3

[0034] A method for preparing a highly dispersible phthalocyanine pigment comprises the following steps:

[0035] (1) Ultrasonic dispersion of silane coupling agent and graphene oxide in a solvent, heating for reaction, centrifugation, washing, and drying to obtain modified graphene oxide; the mass ratio of silane coupling agent to graphene oxide is 0.3:1; the silane coupling agent is a mixture of octyltrimethoxysilane, dodecyltrimethoxysilane, and octadecyltrimethoxysilane in a molar ratio of 1:1:1; the graphene oxide is a single-layer graphene oxide; the ultrasonic power is 200 W; the solvent is a mixed solvent of deionized water and ethanol in a volume ratio of 1:1; the heating reaction temperature is 40°C, and the reaction time is 2 h;

[0036] (2) Dispersing modified graphene oxide, polyethylene glycol and copper phthalocyanine pigment in an organic solvent acetone, stirring and reacting at 40°C for 2.4 hours, filtering, washing and drying to obtain a highly dispersed phthalocyanine pigment; the mass ratio of copper phthalocyanine pigment to modified graphene oxide and polyethylene glycol is 100:3:1; the copper phthalocyanine pigment is phthalocyanine blue BGS; and the number average molecular weight of polyethylene glycol is 400.

[0037] Example 4

[0038] A method for preparing a highly dispersible phthalocyanine pigment comprises the following steps:

[0039] (1) Ultrasonic dispersion of silane coupling agent and graphene oxide in a solvent, heating for reaction, centrifugation, washing, and drying to obtain modified graphene oxide; the mass ratio of silane coupling agent to graphene oxide is 0.4:1; the silane coupling agent is a mixture of decyltriethoxysilane and tetradecyltrimethoxysilane in a molar ratio of 1:1; the graphene oxide is a single-layer graphene oxide; the ultrasonic power is 120 W; the solvent is a mixed solvent of deionized water and ethanol in a volume ratio of 1:1; the heating reaction temperature is 45°C, and the reaction time is 2 h;

[0040] (2) Dispersing modified graphene oxide, polyethylene glycol and copper phthalocyanine pigment in an organic solvent acetone, stirring and reacting at 40°C for 3 hours, filtering, washing and drying to obtain a highly dispersed phthalocyanine pigment; the mass ratio of copper phthalocyanine pigment to modified graphene oxide and polyethylene glycol is 100:3.5:0.6; the copper phthalocyanine pigment is phthalocyanine blue BGS; and the number average molecular weight of polyethylene glycol is 400.

[0041] Example 5

[0042] A method for preparing a highly dispersible phthalocyanine pigment comprises the following steps:

[0043] (1) Ultrasonic dispersion of silane coupling agent and graphene oxide in a solvent, heating for reaction, centrifugation, washing, and drying to obtain modified graphene oxide; the mass ratio of silane coupling agent to graphene oxide is 0.5:1; the silane coupling agent is a mixture of octyltriethoxysilane and hexadecyltrimethoxysilane in a molar ratio of 1:1; the graphene oxide is a single-layer graphene oxide; the ultrasonic power is 180 W; the solvent is a mixed solvent of deionized water and ethanol in a volume ratio of 1:1; the heating reaction temperature is 55°C, and the reaction time is 2 h;

[0044] (2) The modified graphene oxide, polyethylene glycol and copper phthalocyanine pigment were dispersed in an organic solvent, acetone, and stirred for reaction at 45°C for 3.5 hours. The highly dispersed phthalocyanine pigment was obtained after filtering, washing and drying. The mass ratio of copper phthalocyanine pigment to modified graphene oxide and polyethylene glycol was 100:4.5:0.8. The copper phthalocyanine pigment was phthalocyanine blue BGS. The number average molecular weight of polyethylene glycol was 600.

[0045] Example 6

[0046] A method for preparing a highly dispersible phthalocyanine pigment comprises the following steps:

[0047] (1) Ultrasonic dispersion of silane coupling agent and graphene oxide in a solvent, heating for reaction, centrifugation, washing, and drying to obtain modified graphene oxide; the mass ratio of silane coupling agent to graphene oxide is 0.4:1; the silane coupling agent is a mixture of decyltrimethoxysilane and hexadecyltrimethoxysilane in a molar ratio of 1:1; the graphene oxide is a single-layer graphene oxide; the ultrasonic power is 150 W; the solvent is a mixed solvent of deionized water and ethanol in a volume ratio of 1:1; the heating reaction temperature is 50°C, and the reaction time is 2 h;

[0048] (2) The modified graphene oxide, polyethylene glycol and copper phthalocyanine pigment are dispersed in an organic solvent acetone, stirred and reacted at 42°C for 3 hours, filtered, washed and dried to obtain a highly dispersed phthalocyanine pigment; the mass ratio of copper phthalocyanine pigment to modified graphene oxide and polyethylene glycol is 100:4:0.8; the copper phthalocyanine pigment is phthalocyanine blue BGS; and the number average molecular weight of polyethylene glycol is 600.

[0049] Example 7

[0050] A method for preparing a highly dispersible phthalocyanine pigment comprises the following steps:

[0051] (1) Ultrasonic dispersion of silane coupling agent and graphene oxide in a solvent, heating for reaction, centrifugation, washing, and drying to obtain modified graphene oxide; the mass ratio of silane coupling agent to graphene oxide is 0.1:1; the silane coupling agent is a mixture of decyltrimethoxysilane and hexadecyltrimethoxysilane in a molar ratio of 1:1; the graphene oxide is a single-layer graphene oxide; the ultrasonic power is 150 W; the solvent is a mixed solvent of deionized water and ethanol in a volume ratio of 1:1; the heating reaction temperature is 50°C, and the reaction time is 2 h;

[0052] (2) The modified graphene oxide, polyethylene glycol and copper phthalocyanine pigment are dispersed in an organic solvent acetone, stirred and reacted at 42°C for 3 hours, filtered, washed and dried to obtain a highly dispersed phthalocyanine pigment; the mass ratio of copper phthalocyanine pigment to modified graphene oxide and polyethylene glycol is 100:4:0.8; the copper phthalocyanine pigment is phthalocyanine blue BGS; and the number average molecular weight of polyethylene glycol is 600.

[0053] Example 8

[0054] A method for preparing a highly dispersible phthalocyanine pigment comprises the following steps:

[0055] (1) Ultrasonic dispersion of silane coupling agent and graphene oxide in a solvent, heating for reaction, centrifugation, washing, and drying to obtain modified graphene oxide; the mass ratio of silane coupling agent to graphene oxide is 1:1; the silane coupling agent is a mixture of decyltrimethoxysilane and hexadecyltrimethoxysilane in a molar ratio of 1:1; the graphene oxide is a single-layer graphene oxide; the ultrasonic power is 150 W; the solvent is a mixed solvent of deionized water and ethanol in a volume ratio of 1:1; the heating reaction temperature is 50°C, and the reaction time is 2 h;

[0056] (2) The modified graphene oxide, polyethylene glycol and copper phthalocyanine pigment are dispersed in an organic solvent acetone, stirred and reacted at 42°C for 3 hours, filtered, washed and dried to obtain a highly dispersed phthalocyanine pigment; the mass ratio of copper phthalocyanine pigment to modified graphene oxide and polyethylene glycol is 100:4:0.8; the copper phthalocyanine pigment is phthalocyanine blue BGS; and the number average molecular weight of polyethylene glycol is 600.

[0057] Example 9

[0058] A method for preparing a highly dispersible phthalocyanine pigment comprises the following steps:

[0059] (1) Ultrasonic dispersion of silane coupling agent and graphene oxide in a solvent, heating reaction, centrifugation, washing, and drying to obtain modified graphene oxide; the mass ratio of silane coupling agent to graphene oxide is 0.4:1; the silane coupling agent is decyltrimethoxysilane; the graphene oxide is a single-layer graphene oxide; the ultrasonic power is 150 W; the solvent is a mixed solvent of deionized water and ethanol in a volume ratio of 1:1; the heating reaction temperature is 50 ° C, and the reaction time is 2 h;

[0060] (2) The modified graphene oxide, polyethylene glycol and copper phthalocyanine pigment are dispersed in an organic solvent acetone, stirred and reacted at 42°C for 3 hours, filtered, washed and dried to obtain a highly dispersed phthalocyanine pigment; the mass ratio of copper phthalocyanine pigment to modified graphene oxide and polyethylene glycol is 100:4:0.8; the copper phthalocyanine pigment is phthalocyanine blue BGS; and the number average molecular weight of polyethylene glycol is 600.

[0061] Example 10

[0062] A method for preparing a highly dispersible phthalocyanine pigment comprises the following steps:

[0063] (1) Ultrasonic dispersion of silane coupling agent and graphene oxide in a solvent, heating for reaction, centrifugation, washing, and drying to obtain modified graphene oxide; the mass ratio of silane coupling agent to graphene oxide is 0.4:1; the silane coupling agent is hexadecyltrimethoxysilane; the graphene oxide is a single-layer graphene oxide; the ultrasonic power is 150 W; the solvent is a mixed solvent of deionized water and ethanol in a volume ratio of 1:1; the heating reaction temperature is 50 ° C, and the reaction time is 2 h;

[0064] (2) The modified graphene oxide, polyethylene glycol and copper phthalocyanine pigment are dispersed in an organic solvent acetone, stirred and reacted at 42°C for 3 hours, filtered, washed and dried to obtain a highly dispersed phthalocyanine pigment; the mass ratio of copper phthalocyanine pigment to modified graphene oxide and polyethylene glycol is 100:4:0.8; the copper phthalocyanine pigment is phthalocyanine blue BGS; and the number average molecular weight of polyethylene glycol is 600.

[0065] Embodiment 11

[0066] A method for preparing a highly dispersible phthalocyanine pigment comprises the following steps:

[0067] (1) Ultrasonic dispersion of silane coupling agent and graphene oxide in a solvent, heating for reaction, centrifugation, washing, and drying to obtain modified graphene oxide; the mass ratio of silane coupling agent to graphene oxide is 0.4:1; the silane coupling agent is a mixture of decyltrimethoxysilane and hexadecyltrimethoxysilane in a molar ratio of 1:1; the graphene oxide is a single-layer graphene oxide; the ultrasonic power is 150 W; the solvent is a mixed solvent of deionized water and ethanol in a volume ratio of 1:1; the heating reaction temperature is 50°C, and the reaction time is 2 h;

[0068] (2) Dispersing modified graphene oxide, polyethylene glycol and copper phthalocyanine pigment in an organic solvent acetone, stirring and reacting at 42°C for 3 h, filtering, washing and drying to obtain a highly dispersed phthalocyanine pigment; the mass ratio of copper phthalocyanine pigment to modified graphene oxide and polyethylene glycol is 100:6:0.8; the copper phthalocyanine pigment is phthalocyanine blue BGS; and the number average molecular weight of polyethylene glycol is 600.

[0069] Comparative Example 1

[0070] A method for preparing a highly dispersible phthalocyanine pigment comprises the following steps:

[0071] (1) Ultrasonic dispersion of silane coupling agent and graphene oxide in a solvent, heating for reaction, centrifugation, washing, and drying to obtain modified graphene oxide; the mass ratio of silane coupling agent to graphene oxide is 0.4:1; the silane coupling agent is a mixture of decyltrimethoxysilane and hexadecyltrimethoxysilane in a molar ratio of 1:1; the graphene oxide is a single-layer graphene oxide; the ultrasonic power is 150 W; the solvent is a mixed solvent of deionized water and ethanol in a volume ratio of 1:1; the heating reaction temperature is 50°C, and the reaction time is 2 h;

[0072] (2) Dispersing modified graphene oxide, polyethylene glycol and copper phthalocyanine pigment in an organic solvent acetone, stirring and reacting at 42°C for 3 h, filtering, washing and drying to obtain a highly dispersed phthalocyanine pigment; the mass ratio of copper phthalocyanine pigment to modified graphene oxide and polyethylene glycol is 100:0:4.8; the copper phthalocyanine pigment is phthalocyanine blue BGS; and the number average molecular weight of polyethylene glycol is 600.

[0073] Comparative Example 2

[0074] A method for preparing a highly dispersible phthalocyanine pigment comprises the following steps:

[0075] (1) Ultrasonic dispersion of silane coupling agent and graphene oxide in a solvent, heating for reaction, centrifugation, washing, and drying to obtain modified graphene oxide; the mass ratio of silane coupling agent to graphene oxide is 0.4:1; the silane coupling agent is a mixture of decyltrimethoxysilane and hexadecyltrimethoxysilane in a molar ratio of 1:1; the graphene oxide is a single-layer graphene oxide; the ultrasonic power is 150 W; the solvent is a mixed solvent of deionized water and ethanol in a volume ratio of 1:1; the heating reaction temperature is 50°C, and the reaction time is 2 h;

[0076] (2) Dispersing modified graphene oxide, polyethylene glycol and copper phthalocyanine pigment in an organic solvent acetone, stirring and reacting at 42°C for 3 h, filtering, washing and drying to obtain a highly dispersed phthalocyanine pigment; the mass ratio of copper phthalocyanine pigment to modified graphene oxide and polyethylene glycol is 100:4.8:0; the copper phthalocyanine pigment is phthalocyanine blue BGS; and the number average molecular weight of polyethylene glycol is 600.

[0077] Comparative Example 3

[0078] A method for preparing a highly dispersible phthalocyanine pigment comprises the following steps:

[0079] (1) Ultrasonic dispersion of silane coupling agent and graphene oxide in a solvent, heating for reaction, centrifugation, washing, and drying to obtain modified graphene oxide; the mass ratio of silane coupling agent to graphene oxide is 0.4:1; the silane coupling agent is a mixture of decyltrimethoxysilane and hexadecyltrimethoxysilane in a molar ratio of 1:1; the graphene oxide is a single-layer graphene oxide; the ultrasonic power is 150 W; the solvent is a mixed solvent of deionized water and ethanol in a volume ratio of 1:1; the heating reaction temperature is 50°C, and the reaction time is 2 h;

[0080] (2) Dispersing modified graphene oxide, polyethylene glycol and copper phthalocyanine pigment in an organic solvent acetone, stirring and reacting at 42°C for 3 h, filtering, washing and drying to obtain a highly dispersed phthalocyanine pigment; the mass ratio of copper phthalocyanine pigment to modified graphene oxide and polyethylene glycol is 100:4:0.1; the copper phthalocyanine pigment is phthalocyanine blue BGS; and the number average molecular weight of polyethylene glycol is 600.

[0081] Comparative Example 4

[0082] A method for preparing a highly dispersible phthalocyanine pigment comprises the following steps:

[0083] (1) Ultrasonic dispersion of silane coupling agent and graphene oxide in a solvent, heating for reaction, centrifugation, washing, and drying to obtain modified graphene oxide; the mass ratio of silane coupling agent to graphene oxide is 0.4:1; the silane coupling agent is a mixture of decyltrimethoxysilane and hexadecyltrimethoxysilane in a molar ratio of 1:1; the graphene oxide is a single-layer graphene oxide; the ultrasonic power is 150 W; the solvent is a mixed solvent of deionized water and ethanol in a volume ratio of 1:1; the heating reaction temperature is 50°C, and the reaction time is 2 h;

[0084] (2) Dispersing modified graphene oxide, polyethylene glycol and copper phthalocyanine pigment in an organic solvent acetone, stirring and reacting at 42°C for 3 h, filtering, washing and drying to obtain a highly dispersed phthalocyanine pigment; the mass ratio of copper phthalocyanine pigment to modified graphene oxide and polyethylene glycol is 100:4:2; the copper phthalocyanine pigment is phthalocyanine blue BGS; and the number average molecular weight of polyethylene glycol is 600.

[0085] Comparative Example 5

[0086] A method for preparing a highly dispersible phthalocyanine pigment comprises the following steps:

[0087] (1) Ultrasonic dispersion of silane coupling agent and graphene in a solvent, heating for reaction, centrifugation, washing, and drying to obtain modified graphene; the mass ratio of silane coupling agent to graphene is 0.4:1; the silane coupling agent is n-propyltrimethoxysilane; the graphene is single-layer graphene; the ultrasonic power is 150W; the solvent is a mixed solvent of deionized water and ethanol in a volume ratio of 1:1; the heating reaction temperature is 50°C, and the reaction time is 2h;

[0088] (2) The modified graphene, polyethylene glycol and copper phthalocyanine pigment are dispersed in an organic solvent acetone, stirred and reacted at 42°C for 3 hours, filtered, washed and dried to obtain a highly dispersed phthalocyanine pigment; the mass ratio of copper phthalocyanine pigment to modified graphene and polyethylene glycol is 100:4:0.8; the copper phthalocyanine pigment is phthalocyanine blue BGS; and the number average molecular weight of polyethylene glycol is 600.

[0089] Performance test: The particle sizes of the phthalocyanine pigments prepared in Examples 1-11 and Comparative Examples 1-5 were tested using a laser particle size analyzer. The results are shown in Table 1.

[0090]

[0091] As can be seen from Table 1, the present invention selects modified graphene oxide as the modifier of copper phthalocyanine. Graphene oxide and copper phthalocyanine molecules are both two-dimensional planar structures with conjugated π electrons, and copper phthalocyanine molecules can be parallel to graphene oxide sheets to form π-π stacking, so that non-covalently bound complexes are obtained, which prevents copper phthalocyanine pigments from agglomerating and reduces their particle size. The organophilic groups in the long straight carbon chain silane coupling agent can be physically entangled with the copper phthalocyanine organic molecules, so that the interface of graphene oxide and copper phthalocyanine pigments can be bonded, greatly improving the ability of graphene oxide to disperse copper phthalocyanine pigments. There are multiple oxygen-containing anchoring functional groups on the molecular structure of polyethylene glycol, which can be combined with copper phthalocyanine pigment surface multi-sites by ionic bonds, hydrogen bonds and van der Waals forces at the same time, forming a firm adsorption layer, making up for the deficiency of modified graphene oxide dispersant, enhancing the spatial repulsion between copper phthalocyanine pigment particles, thereby enhancing the stability of copper phthalocyanine pigments. Therefore, polyethylene glycol polymer dispersant and modified graphene oxide inorganic dispersant are used to modify the copper phthalocyanine pigment, thereby improving the dispersion stability of the copper phthalocyanine pigment.

[0092] Specifically, it can be seen from Examples 1-11 and Comparative Examples 1-5 that the phthalocyanine pigment prepared in Examples 1-11 has a smaller particle size, and the difference between D10, D50, and D90 of each example fluctuates less than that of the comparative example, indicating that the phthalocyanine pigment prepared in Examples 1-11 has a more uniform particle size, a more concentrated particle size distribution, and better dispersibility. Comparative Examples 1 and 2 do not add modified graphene oxide or polyethylene glycol, and the particle size is larger, the particle size is uneven, and the dispersibility is poor. This shows that the use of a single inorganic material modification or a polymer dispersant for modification has limited effect, and it is necessary to add a polyethylene glycol polymer dispersant and a modified graphene oxide inorganic dispersant at the same time to modify the copper phthalocyanine pigment and improve the dispersion stability of the copper phthalocyanine pigment. Comparative Examples 3-4 show that polyethylene glycol, as a polymer dispersant, should be used in a controlled amount. If the dosage is too small, the modification effect cannot be achieved; if the dosage is too large, it will cause the dispersion of modified graphene oxide to be difficult, affecting the formation of π-π stacking structure between copper phthalocyanine molecules and graphene oxide sheets. Comparative Example 5 shows that graphene does not contain hydrophilic functional groups, short carbon chain silane coupling agents do not contain long chains, the adsorption effect with copper phthalocyanine organic pigments is reduced, the particle size is large, the particle size is uneven, and the dispersion performance of the pigment cannot be improved.

[0093] Although the present invention has been disclosed as above in the preferred embodiment, it is not intended to limit the present invention. Anyone familiar with this technology can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be based on the definition of the claims.

Claims

1. A method for preparing a highly dispersible phthalocyanine pigment, characterized in that: The following steps are involved: (1) ultrasonically dispersing a silane coupling agent and graphene oxide in a solvent, heating for reaction, centrifuging, washing, and drying to obtain modified graphene oxide; the mass ratio of the silane coupling agent to the graphene oxide is (0.3-0.6):1; the silane coupling agent is at least two of octyltrimethoxysilane, nonyltrimethoxysilane, decyltrimethoxysilane, undecyltrimethoxysilane, dodecyltrimethoxysilane, tridecyltrimethoxysilane, tetradecyltrimethoxysilane, pentadecyltrimethoxysilane, hexadecyltrimethoxysilane, and octadecyltrimethoxysilane, or the silane coupling agent is at least two of octyltriethoxysilane, nonyltriethoxysilane, decyltriethoxysilane, undecyltriethoxysilane, dodecyltriethoxysilane, tridecyltriethoxysilane, tetradecyltriethoxysilane, pentadecyltriethoxysilane, hexadecyltriethoxysilane, and octadecyltriethoxysilane; (2) Dispersing modified graphene oxide, polyethylene glycol and copper phthalocyanine pigment in an organic solvent, stirring and reacting at 35-50°C for 2-4 hours, filtering, washing and drying to obtain a highly dispersed phthalocyanine pigment; the mass ratio of copper phthalocyanine pigment to modified graphene oxide and polyethylene glycol is 100:(2-6):(0.5-1).

2. The method for preparing a highly dispersible phthalocyanine pigment according to claim 1, wherein: In step (1), the graphene oxide is a single-layer graphene oxide or a multi-layer graphene oxide.

3. The method for preparing a highly dispersible phthalocyanine pigment according to claim 1, wherein: The ultrasonic power in step (1) is 100-200W.

4. The method for preparing a highly dispersible phthalocyanine pigment according to claim 1, characterized in that: The solvent in step (1) is a mixed solvent of deionized water and ethanol.

5. The method for preparing a highly dispersible phthalocyanine pigment according to claim 1, characterized in that: The heating reaction temperature in step (1) is 40-60°C.

6. The method for preparing a highly dispersible phthalocyanine pigment according to claim 1, characterized in that: In step (2), the copper phthalocyanine pigment is phthalocyanine blue.

7. The method for preparing a highly dispersible phthalocyanine pigment according to claim 1, characterized in that: The organic solvent in step (2) is at least one of methanol, ethanol, propanol, propylene glycol, acetone and nitrogen methyl pyrrolidone.

8. The method for preparing a highly dispersible phthalocyanine pigment according to claim 1, characterized in that: The number average molecular weight of the polyethylene glycol in step (2) is 200-800.

9. A highly dispersible phthalocyanine pigment, characterized in that: The phthalocyanine pigment is prepared by the method for preparing a highly dispersible phthalocyanine pigment according to any one of claims 1 to 8.

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