Phthalocyanine green, and preparation method and application thereof

Abstract

The application belongs to the field of ink, and particularly relates to a phthalocyanine green, a preparation method and application thereof. The preparation method of the phthalocyanine green comprises the following steps: 1) mixing phthalic anhydride, urea, cuprous chloride, ammonium molybdate, a solvent and a rare earth chloride, and then performing a first reaction to obtain a first mixture; 2) adding an alkaline aqueous solution to the first mixture obtained in the step 1) to perform a second reaction, remove the organic solvent, cool, and perform suction filtration to obtain a filter cake; 3) washing the filter cake obtained in the step 2) to obtain copper phthalocyanine; 4) performing a third reaction on the copper phthalocyanine obtained in the step 3) in a eutectic mixture of ferric chloride and aluminum chloride and with chlorine in a catalyst to obtain the phthalocyanine green. The purity of the phthalocyanine green prepared by the preparation method of the phthalocyanine green can be improved to more than 99%. The color paste obtained by mixing the phthalocyanine green prepared by the preparation method of the phthalocyanine green and linoleum has good infrared reflectivity at 830-870 nm.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of ink, and particularly relates to a phthalocyanine green and a preparation method and application thereof. BACKGROUND

[0002] C.I. Pigment Green 7 [CAS No. 1328-53-6] is an organic pigment with a copper phthalocyanine structure, and its structure is as follows:

[0003]

[0004] C.I. Pigment Green 7 is blue-green, has good fastness to fat, oil, soap and paraffin, and is suitable for rubber coloring and packaging ink preparation.

[0005] Chinese patent CN108084732.A discloses an environmentally friendly preparation method of phthalocyanine green, comprising the following steps: (1) adding aluminum chloride and sodium chloride into a reaction kettle, heating to 145-155℃, stopping heating after the materials are completely melted, and then adding copper phthalocyanine and copper chloride in sequence; (2) after the addition of copper phthalocyanine and copper chloride is completed, heating is restarted to 165-170℃, and the temperature is kept for 14-18 hours for reaction under the condition of passing chlorine gas; (3) the reaction liquid obtained in step (2) is put into a dilution tank while hot, stirred, cooled, washed with water until the washing liquid is neutral, beaten, and then emulsion is added, washed with water again, filtered, beaten, and then formed into balls by adding dichlorobenzene, and then the phthalocyanine green product is obtained after post-treatment. The preparation method provided by the present application can prepare high-quality phthalocyanine green with small particle size, uniform particle size distribution, excellent color light and strong coloring power.

[0006] Chinese patent CN105647225.A discloses a preparation method of phthalocyanine green G, which comprises the following steps: adding water into a reaction kettle, then feeding selected aluminum chloride into the reaction kettle for reaction, then adding copper phthalocyanine and cuprous chloride into the reaction kettle for mixed reaction, then passing chlorine gas into the reaction kettle, then performing acid-base cleaning, and finally obtaining a semi-finished product by cleaning through a filter press, and then sequentially performing drying, powdering and bagging to obtain a finished product. The acid-base treatment adopted in the present application can reduce impurities in the product, stabilize the physical properties of the product, and also prevent the product from fading. The filter press is used in the production process, so that the environmental pollution is small, and the product is concentrated in the filter press, thereby reducing waste.

[0007] In Chinese patent CN106574129A, a flaky infrared emission composition is prepared, wherein the metal film layer is mainly one of silver, aluminum, copper, gold, palladium, zinc, titanium, etc., and the dielectric layer is at least one of titanium dioxide, zinc oxide, aluminum oxide, zirconium oxide, silicon dioxide, tin oxide, indium tin oxide, and antimony-doped tin oxide, so as to improve the reflectivity. In patent CN104684848A, the improvement of infrared reflectivity is mainly realized by using a kind of antimony-doped tin oxide.

[0008] The above patents do not solve the problem from the synthesis end. The doping method has the disadvantage that it may cause uneven mixing of pigments, affecting the color, or the hardness of metal oxides such as zirconium oxide may affect the processing performance of the finished pigments. At present, reducing the infrared reflectivity of copper phthalocyanine pigments can expand their application range in special ink application fields. At present, no one has found a method for improving the infrared reflectivity of pigments. SUMMARY

[0009] The first aspect of the purpose of the present application is to provide a method for preparing phthalocyanine green, comprising the following steps,

[0010] 1) mixing phthalic anhydride, urea, cuprous chloride, ammonium molybdate, a solvent and a rare earth chloride, and then performing a first reaction to obtain a first mixture;

[0011] 2) adding an alkaline aqueous solution to the first mixture obtained in step 1) to perform a second reaction, removing the organic solvent, cooling, and suction filtering to obtain a filter cake;

[0012] 3) washing the filter cake obtained in step 2) to obtain copper phthalocyanine;

[0013] 4) performing a third reaction on the copper phthalocyanine obtained in step 3) in a eutectic mixture of ferric chloride and aluminum chloride with chlorine in a catalyst to obtain the phthalocyanine green.

[0014] Preferably, at least one of the following technical features is included:

[0015] 11) In step 1), the mass ratio of the phthalic anhydride to the urea is 1:1-2:1;

[0016] 12) In step 1), the mass ratio of the phthalic anhydride to the cuprous chloride is 1.5:0.25-2:0.25;

[0017] 13) In step 1), the mass ratio of the phthalic anhydride to the ammonium molybdate is 1.5:0.5-1.5:1;

[0018] 14) In step 1), the mass ratio of the phthalic anhydride to the solvent is 1.5:3-3:3;

[0019] 15) In step 1), the mass ratio of the phthalic anhydride to the rare earth chloride is 1.5:0.05-1.5:0.1;

[0020] 16) In step 1), the heating after mixing is included;

[0021] 21) In step 2), the mass ratio of the first mixture to the alkaline aqueous solution is 1:2-1:3;

[0022] 22) In step 2), the method for removing the organic solvent is water vapor distillation;

[0023] 23) In step 2), the time for cooling is 0.5-4h;

[0024] 31) In step 3), the washing includes first water washing, acid washing, and second water washing;

[0025] 41) In step 4), the flow rate of the chlorine gas is 30-40kg / h;

[0026] 42) In step 4), the catalyst is copper chloride;

[0027] 43) In step 4), the temperature of the third reaction is 180-200℃;

[0028] 44) In step 4), the eutectic mixture of the ferric chloride and the aluminum chloride has a mass ratio of 1:1-1:1.5;

[0029] Preferably, at least one of the following technical features is included:

[0030] 141) In feature 14), the solvent is trichlorobenzene or chlorobenzene;

[0031] 161) In feature 16), the heating is to 175-195℃;

[0032] 162) In feature 16), the holding time after heating is 2-20h;

[0033] 211) In feature 21), the alkaline aqueous solution is selected from a sodium hydroxide aqueous solution or a potassium hydroxide aqueous solution;

[0034] 311) In feature 31), the first water washing is to pH>6;

[0035] 312) In feature 31), the reagent for the acid washing is dilute hydrochloric acid;

[0036] 313) In feature 31), the acid washing further includes boiling;

[0037] 314) In feature 31), the second water washing is to pH of 6-8;

[0038] Preferably, at least one of the following technical features is included:

[0039] 1621) In feature 162), the holding time is 2-4h;

[0040] 3121) In feature 312), the mass ratio of the filter cake to the dilute hydrochloric acid is 1:2-1:3;

[0041] 3122) In feature 312), the concentration of the dilute hydrochloric acid is 10-15%wt;

[0042] 3131) In feature 313), the boiling time is 12-24h;

[0043] Preferably, in step 1), the rare earth element in the rare earth chloride is selected from one or more of La, Ce, Pr, Nd, Sm, Eu, and Gd.

[0044] Preferably, in step 1), the rare earth chloride accounts for 0.01-0.1wt% of the total amount of reactants.

[0045] Preferably, in step 2), the mass fraction of the aqueous sodium hydroxide solution is 5-10%.

[0046] Preferably, in step 2), the temperature of the second reaction is 180-200℃.

[0047] The second aspect of the present application provides a phthalocyanine green prepared by the above method.

[0048] The third aspect of the present application provides the use of the above phthalocyanine green in ink.

[0049] Preferably, the infrared reflectivity of the ink at 830-870nm is improved.

[0050] The present application has the following beneficial technical effects:

[0051] 1) The purity of the phthalocyanine green prepared by the preparation method of the phthalocyanine green of the present application can be improved to more than 99%.

[0052] 2) The phthalocyanine green prepared by the preparation method of the phthalocyanine green of the present application has very good infrared reflectivity at 830-870nm after being mixed with linoleum. BRIEF DESCRIPTION OF DRAWINGS

[0053] Figure 1 The infrared reflectivity graph of Example 1 and Comparative Example in the present application at 850nm. DETAILED DESCRIPTION

[0054] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

[0055] It should be noted that the process equipment or apparatus not specifically mentioned in the following embodiments are all conventional equipment or apparatus in the art.

[0056] Example 1

[0057] 1) Mix 1.5g phthalic anhydride, 1.5g urea, 0.25g cuprous chloride, 0.5g ammonium molybdate, 3g trichlorobenzene and 0.05g lanthanum chloride, stir evenly, heat to 175±2℃, and carry out the first reaction for 15h to obtain the first mixture;

[0058] 2) Add a 10% sodium hydroxide aqueous solution to the first mixture obtained in step 1) to carry out a second reaction at 30°C. The mass ratio of the sodium hydroxide aqueous solution added to the first reaction mixture is 2:1. Then, steam distillation is performed to remove the organic solvent. The mixture is then cooled naturally at ambient temperature for 2 hours and filtered to obtain a filter cake.

[0059] 3) Wash the filter cake obtained in step 2) with water until the pH is greater than 6. Then put the washed filter cake into dilute hydrochloric acid with a mass fraction of 3%-5%, boil for 12 hours, and then filter with water until neutral to obtain copper phthalocyanine.

[0060] 4) The copper phthalocyanine obtained in step 3) is suspended in a eutectic mixture of ferric chloride and aluminum chloride in a mass ratio of 1:1. Copper chloride is used as a catalyst to carry out a third reaction with chlorine at 180°C. The amount of chlorine is controlled to be 30-40 kg / h, and phthalocyanine green is obtained by addition.

[0061] like Figure 1 As shown, in this embodiment, the purity of the phthalocyanine green is 97.5%, and the color paste obtained by mixing the phthalocyanine green with linoleic acid has an infrared reflectance of 11.12% at 850 nm.

[0062] Example 2

[0063] 1) Mix 1.5g phthalic anhydride, 1.5g urea, 0.25g cuprous chloride, 0.5g ammonium molybdate, 3g trichlorobenzene and 0.05g cerium chloride, stir evenly, heat to 175±2℃, and carry out the first reaction for 15h to obtain the first mixture;

[0064] 2) adding 10% sodium hydroxide solution to the first mixture obtained in step 1) to carry out a second reaction at 30°C, wherein the mass ratio of the amount of sodium hydroxide solution to the first reaction mixture is 2:1, then carrying out water vapor distillation to remove the organic solvent, naturally cooling for 2 hours at natural temperature, and performing suction filtration to obtain a filter cake;

[0065] 3) performing water washing on the filter cake obtained in step 2) until the pH is greater than 6, then placing the water-washed filter cake into 3%-5% dilute hydrochloric acid, adding boiling for 12 hours, and then adding water to filter to neutral to obtain copper phthalocyanine;

[0066] 4) suspending the copper phthalocyanine obtained in step 3) in a eutectic mixture of iron chloride and aluminum chloride, using copper chloride as a catalyst, and carrying out a third reaction with chlorine gas at 180°C, wherein the amount of chlorine gas is controlled to be 30-40 kg / h, and the phthalocyanine green is obtained by addition.

[0067] In this embodiment, the purity of the phthalocyanine green is 97.6%, and the infrared reflectivity of the color paste obtained by mixing the obtained phthalocyanine green with linoleum at 850n is 12.7%.

[0068] Embodiment 3

[0069] 1) mixing 1.5 g of phthalic anhydride, 1.5 g of urea, 0.25 g of cuprous chloride, 0.5 g of ammonium molybdate, 3 g of trichlorobenzene, and 0.05 g of praseodymium chloride, stirring uniformly, heating to 175±2°C, and carrying out a first reaction for 15 hours to obtain a first mixture;

[0070] 2) adding 10% sodium hydroxide solution to the first mixture obtained in step 1) to carry out a second reaction at 30°C, wherein the mass ratio of the amount of sodium hydroxide solution to the first reaction mixture is 2:1, then carrying out water vapor distillation to remove the organic solvent, naturally cooling for 2 hours at natural temperature, and performing suction filtration to obtain a filter cake;

[0071] 3) performing water washing on the filter cake obtained in step 2) until the pH is greater than 6, then placing the water-washed filter cake into 3%-5% dilute hydrochloric acid, adding boiling for 16 hours, and then adding water to filter to neutral to obtain copper phthalocyanine;

[0072] 4) suspending the copper phthalocyanine obtained in step 3) in a eutectic mixture of iron chloride and aluminum chloride with a mass ratio of 1:1, using copper chloride as a catalyst, and carrying out a third reaction with chlorine gas at 180°C, wherein the amount of chlorine gas is controlled to be 30-40 kg / h, and the phthalocyanine green is obtained by addition.

[0073] In this embodiment, the purity of the phthalocyanine green is 98.2%, and the infrared reflectivity of the color paste obtained by mixing the obtained phthalocyanine green with linoleum at 850n is 12.7%.

[0074] Example 4

[0075] 1) After mixing 1.5g of phthalic anhydride, 1.5g of urea, 0.25g of cuprous chloride, 0.5g of ammonium molybdate, 3g of trichlorobenzene and 0.05g of neodymium chloride, stirring uniformly, heating to 175±2℃, the first reaction is carried out for 15h to obtain a first mixture;

[0076] 2) The first mixture obtained in step 1) is added with 10% by mass of sodium hydroxide aqueous solution for the second reaction, the temperature of the second reaction is 30℃, wherein the mass ratio of the amount of sodium hydroxide aqueous solution to the first reaction mixture is 2:1, then water vapor distillation is carried out, the organic solvent is removed, and natural cooling is carried out at natural temperature for 1h, and then suction filtration is carried out to obtain a filter cake;

[0077] 3) The filter cake obtained in step 2) is first washed with water until the pH is greater than 6, and then the filter cake after water washing is put into dilute hydrochloric acid with a mass fraction of 3%-5%, boiled for 12h, and then filtered with water until neutral to obtain copper phthalocyanine;

[0078] 4) The copper phthalocyanine obtained in step 3) is suspended in a eutectic mixture of iron chloride and aluminum chloride with a mass ratio of 1:1, and a third reaction is carried out with chlorine gas at 180℃ using copper chloride as a catalyst, and the amount of chlorine gas is controlled to be 30-40kg / h for addition to obtain phthalocyanine green.

[0079] In this embodiment, the purity of the phthalocyanine green is 98.3%, and the infrared reflectivity of the color paste obtained by mixing the obtained phthalocyanine green with linoleum at 850n is 12.6%.

[0080] Example 5

[0081] 1) After mixing 1.5g of phthalic anhydride, 1.5g of urea, 0.25g of cuprous chloride, 0.5g of ammonium molybdate, 3g of trichlorobenzene and 0.05g of samarium chloride, stirring uniformly, heating to 175±2℃, the first reaction is carried out for 15h to obtain a first mixture;

[0082] 2) The first mixture obtained in step 1) is added with 10% by mass of sodium hydroxide aqueous solution for the second reaction, the temperature of the second reaction is 30℃, wherein the mass ratio of the amount of sodium hydroxide aqueous solution to the first reaction mixture is 2:1, then water vapor distillation is carried out, the organic solvent is removed, and natural cooling is carried out at natural temperature for 1h, and then suction filtration is carried out to obtain a filter cake;

[0083] 3) The filter cake obtained in step 2) is first washed with water until the pH is greater than 6, and then the washed filter cake is placed in dilute hydrochloric acid with a mass fraction of 3%-5%, boiled for 12 h, and then filtered with water until neutral to obtain copper phthalocyanine;

[0084] 4) The copper phthalocyanine obtained in step 3) is suspended in a eutectic mixture of iron chloride and aluminum chloride with a mass ratio of 1:1, and a third reaction is performed with chlorine gas at 180°C using copper chloride as a catalyst, and the phthalocyanine green is obtained by addition of chlorine gas at a rate of 30-40 kg / h.

[0085] In this embodiment, the purity of the phthalocyanine green is 98.5%, and the infrared reflectivity of the color paste obtained by mixing the obtained phthalocyanine green with linoleum at 850n is 13.1%.

[0086] Example 6

[0087] 1) 1.5 g of phthalic anhydride, 1.5 g of urea, 0.25 g of cuprous chloride, 0.5 g of ammonium molybdate, 3 g of trichlorobenzene, and 0.05 g of europium chloride are mixed and stirred uniformly, heated to 175±2°C, and a first reaction is performed for 15 h to obtain a first mixture;

[0088] 2) A second reaction is performed on the first mixture obtained in step 1) by adding a 10% mass fraction of sodium hydroxide aqueous solution, and the temperature of the second reaction is 30°C, wherein the mass ratio of the amount of sodium hydroxide aqueous solution added to the first reaction mixture is 2:1, then steam distillation is performed to remove the organic solvent, and natural cooling is performed at room temperature for 1 h, and then filtration is performed to obtain a filter cake;

[0089] 3) The filter cake obtained in step 2) is first washed with water until the pH is greater than 6, and then the washed filter cake is placed in dilute hydrochloric acid with a mass fraction of 3%-5%, boiled for 12 h, and then filtered with water until neutral to obtain copper phthalocyanine;

[0090] 4) The copper phthalocyanine obtained in step 3) is suspended in a eutectic mixture of iron chloride and aluminum chloride with a mass ratio of 1:1, and a third reaction is performed with chlorine gas at 180°C using copper chloride as a catalyst, and the phthalocyanine green is obtained by addition of chlorine gas at a rate of 30-40 kg / h.

[0091] In this embodiment, the purity of the phthalocyanine green is 98.6%, and the infrared reflectivity of the color paste obtained by mixing the obtained phthalocyanine green with linoleum at 850n is 13.1%.

[0092] Example 7

[0093] 1) 1.5 g of phthalic anhydride, 1.5 g of urea, 0.25 g of cuprous chloride, 0.5 g of ammonium molybdate, 3 g of trichlorobenzene and 0.05 g of gadolinium chloride are mixed, stirred uniformly, heated to 175 ± 2 °C and subjected to a first reaction for 15 h to obtain a first mixture;

[0094] 2) The first mixture obtained in step 1) is subjected to a second reaction with the addition of 10% by mass of sodium hydroxide aqueous solution, the temperature of the second reaction is 30 °C, the amount of sodium hydroxide aqueous solution added is 2:1 by mass ratio to the first reaction mixture, then water vapor distillation is performed, the organic solvent is removed, and the mixture is naturally cooled for 2 h at natural temperature, and then filtered to obtain a filter cake;

[0095] 3) The filter cake obtained in step 2) is subjected to a first water washing until the pH is greater than 6, then the filter cake after water washing is placed in 3%-5% by mass of dilute hydrochloric acid, boiled for 12 h, and then filtered with water until neutral to obtain copper phthalocyanine;

[0096] 4) The copper phthalocyanine obtained in step 3) is suspended in a eutectic mixture of iron chloride and aluminum chloride with a mass ratio of 1:1, and a third reaction is performed with chlorine gas at 180 °C using copper chloride as a catalyst, and the amount of chlorine gas is controlled to be 30-40 kg / h to add to obtain phthalocyanine green.

[0097] In this embodiment, the purity of the phthalocyanine green is 98.4%, and the infrared reflectivity of the color paste obtained by mixing the obtained phthalocyanine green with linoleum at 850 n is 13.2%.

[0098] Comparative Example

[0099] (1) Selection of materials: the following raw materials are selected by mass parts: aluminum chloride 18-20 parts, industrial salt 2-3 parts, copper phthalocyanine 4-5 parts, cuprous chloride 0.3-0.4 parts, and chlorine gas 9-11 parts;

[0100] (2) One-step reaction: water is added to a reaction kettle, and then the selected aluminum chloride is fed into the reaction kettle for reaction, the reaction time is 0.5-1 h, and the reaction temperature is 220-250 °C;

[0101] (3) Two-step reaction: copper phthalocyanine and cuprous chloride are added to the material after one-step reaction for mixing and reaction, the reaction time is 7-8 h, and the reaction temperature is 180-220 °C;

[0102] (4) Three-step reaction: chlorine gas is introduced into the material after two-step reaction, the reaction time is 11-12 h, and the reaction temperature is 160-180 °C to obtain phthalocyanine green.

[0103] As Figure 1As shown, the infrared reflectance of the color paste obtained by mixing the phthalocyanine green obtained above with linoleum at 850 nm is 3.79%.

[0104] The above embodiments are only illustrative of the principles and effects of the present application, and are not intended to limit the present application. Any person skilled in the art can modify or change the above embodiments without departing from the spirit and scope of the present application. Therefore, all equivalent modifications or changes made by those skilled in the art without departing from the spirit and technical thought disclosed by the present application should be covered by the claims of the present application.

Claims

1. A method for preparing phthalocyanine green, characterized by, The method comprises the following steps: 1) mixing phthalic anhydride, urea, cuprous chloride, ammonium molybdate, a solvent and a rare earth chloride to perform a first reaction to obtain a first mixture; 2) adding an alkaline aqueous solution to the first mixture obtained in step 1) to perform a second reaction, removing the organic solvent, cooling, and suction filtering to obtain a filter cake; 3) washing the filter cake obtained in step 2) to obtain copper phthalocyanine; 4) performing a third reaction on the copper phthalocyanine obtained in step 3) in a eutectic mixture of ferric chloride and aluminum chloride with chlorine gas in a catalyst to obtain the phthalocyanine green.

2. The method for preparing phthalocyanine green according to claim 1, characterized in that, At least one of the following technical features is comprised: 11) in step 1), the mass ratio of the phthalic anhydride to the urea is 1:1-2:1; 12) in step 1), the mass ratio of the phthalic anhydride to the cuprous chloride is 1.5:0.25-2:0.25; 13) in step 1), the mass ratio of the phthalic anhydride to the ammonium molybdate is 1.5:0.5-1.5:1; 14) in step 1), the mass ratio of the phthalic anhydride to the solvent is 1.5:3-3:3; 15) in step 1), the mass ratio of the phthalic anhydride to the rare earth chloride is 1.5:0.05-1.5:0.1; 16) in step 1), the mixing comprises heating; 21) in step 2), the mass ratio of the first mixture to the alkaline aqueous solution is 1:2-1:3; 22) in step 2), the method for removing the organic solvent is water vapor distillation; 23) in step 2), the cooling time is 0.5-4h; 31) in step 3), the washing comprises first water washing, acid washing, and second water washing; 41) in step 4), the flow rate of the chlorine gas is 30-40kg / h; 42) in step 4), the catalyst is copper chloride; 43) in step 4), the temperature of the third reaction is 180-200℃; 44) in step 4), the ratio of the eutectic mixture of ferric chloride and aluminum chloride is 1:1-1:1.5 in mass ratio.

3. The method for preparing phthalocyanine green according to claim 2, characterized in that, At least one of the following technical features is comprised: 141) in feature 14), the solvent is trichlorobenzene or chlorobenzene; 161) in feature 16), the heating is to 175-195℃; 162) in feature 16), the holding time after the heating is 2-20h; 211) in feature 21), the alkaline aqueous solution is selected from sodium hydroxide aqueous solution or potassium hydroxide aqueous solution; 311) in feature 31), the first water washing is to pH>6; 312) in feature 31), the reagent for the acid washing is dilute hydrochloric acid; 313) in feature 31), the acid washing further comprises boiling; 314) in feature 31), the second water washing is to pH 6-8.

4. The method for preparing phthalocyanine green according to claim 3, characterized in that, At least one of the following technical features is comprised: 1621) in feature 162), the holding time is 2-4h; 3121) in feature 312), the mass ratio of the filter cake to the dilute hydrochloric acid is 1:2-1:3; 3122) in feature 312), the concentration of the dilute hydrochloric acid is 10-15%wt; 3131) in feature 313), the boiling time is 12-24h.

5. Process for the preparation of pthalocyanine green according to any one of claims 1 to 4, characterized in that, In step 1), the rare earth element in the rare earth chloride is selected from one or more of La, Ce, Pr, Nd, Sm, Eu, and Gd; In step 1), the rare earth chloride accounts for 0.01-0.1 wt% of the total amount of the reactants.

6. Process for the preparation of pthalocyanine green according to any one of claims 1 to 4, characterized in that, In step 2), the mass fraction of the aqueous sodium hydroxide solution is 5-10%.

7. Process for the preparation of pthalocyanine green according to any one of claims 1 to 4, characterized in that, In step 2), the temperature of the second reaction is 180-200°C.

8. A phthalocyanine green obtained by the method according to any one of claims 1-7.

9. Use of the phthalocyanine green according to claim 8 in an ink.

10. Use of phthalocyanine green according to claim 9 in inks, characterized in that, Enhancing the infrared reflectivity of the ink at 830-870 nm.

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