An improved method for manufacturing quinacridone solid solution pigments

Abstract

The present invention relates to the field of pigments, particularly quinacridone pigments and quinacridone solid solution pigments and their preparation methods, specifically an improved method for manufacturing quinacridone solid solution pigments. A quinacridone solid solution pigment, by mass percentage, comprises 10% - 90% of a disubstituted quinacridone having the formula (1), and 10% - 90% of 1,3,6,9,11,14 - hexahydroimidazo[4'5':5,6]quinolino[3,2 - i]imidazo[4,5 - α]acridine - 2,8,10,16 - tetrone having the formula (2). The present invention provides a manufacturing technique for quinacridone solid solution pigments, and the colored matter obtained by this technique has more excellent heat resistance than classical quinacridone pigments.

Description

Technical Field

[0001] The present invention relates to the field of pigments, and particularly to a method for preparing quinacridone pigments and quinacridone solid solution pigments, specifically an improved method for manufacturing quinacridone solid solution pigments. Background Art

[0002] Quinacridone is a known compound used as a pigment. In practice, the application of quinacridone has strict requirements for its fastness and coloring properties. When used in engineering plastics such as PP, PA, PC, and ABC, the temperature resistance is required to reach above 320°C, and the existing dosage forms are difficult to meet the above requirements. When used in coil coatings, the temperature resistance of the coating system is required to reach above 200°C, and even reach above 220°C, and the existing quinacridone dosage forms are difficult to meet the above requirements. Summary of the Invention

[0003] The present invention provides a quinacridone solid solution pigment for improving the heat resistance of quinacridone pigments and a preparation method thereof.

[0004] A quinacridone solid solution pigment, calculated by mass percentage, includes:

[0005] ① 10% - 90% of disubstituted quinacridone having the formula (1),

[0006] ② 10% - 90% of 1,3,6,9,11,14 - hexahydroimidazo[4’,5’:5,6]quinolino[3,2 - i]imidazo[4,5 - a]acridine - 2,8,10,16 - tetrone having the formula (2).

[0007]

[0008] In addition, the present invention also provides a preparation method of the quinacridone solid solution pigment.

[0009] It includes the following processes: an intermediate synthesis process, a process for manufacturing crude quinacridone solid solution, and a pigment process.

[0010] (1) In the intermediate synthesis process, in an alcohol solvent system, 5 - amino - benzimidazolone (formula 5) and dimethyl succinylsuccinate (formula 6) are condensed under acid catalysis to obtain an intermediate 2,5 - bis((2 - oxo - 2,3 - dihydro - 1H - benzo[d]imidazol - 5 - yl)amino)dimethyl terephthalate of the following (formula 7). The intermediate of formula (7) undergoes an oxidative hydrolysis reaction in an alcohol solvent under the action of m - nitrobenzenesulfonic acid and a base, and then is acidified to obtain an intermediate of formula (4).

[0011]

[0012] (2) In the manufacturing process of the crude quinacridone solid solution, in polyphosphoric acid, a co-cyclization reaction is carried out between a disubstituted arylamino terephthalic acid (Formula 3) and 2,5-bis((2-oxo-2,3-dihydro-1H-benzo[d]imidazol-5-yl)amino)terephthalic acid (Formula 4) to obtain a solid solution of a disubstituted quinacridone compound (Formula 1) and 1,3,6,9,11,14-hexahydroimidazo[4’,5’:5,6]quinolino[3,2-i]imidazo[4,5-a]acridine-2,8,10,16-tetraone (Formula 2), that is, the crude quinacridone solid solution aqueous filter cake.

[0013] (3) In the pigment chemical process, the aforementioned crude quinacridone solid solution aqueous filter cake is heated in a liquid medium that does not dissolve the crude quinacridone solid solution.

[0014] Preferably, step (1) is specifically the condensation of dimethyl succinylsuccinate and 5-aminobenzimidazolone in ethanol under the catalysis of hydrochloric acid, separating out the filter cake and then carrying out an oxidative hydrolysis reaction with sodium m-nitrobenzenesulfonate and a base in ethanol, and then acid precipitation, washing with water, drying, and pulverizing to obtain the intermediate 2,5-bis((2-oxo-2,3-dihydro-1H-benzo[d]imidazol-5-yl)amino)terephthalic acid incorporating benzimidazolone.

[0015] More preferably, the molar ratio of 5-aminobenzimidazolone to dimethyl succinylsuccinate is 2.14:1 to 2.30:1, the molar ratio of hydrochloric acid to dimethyl succinylsuccinate is 0.05:1 to 0.20:1, the molar ratio of sodium m-nitrobenzenesulfonate to dimethyl succinylsuccinate is 0.95:1 to 1.20:1; the base is sodium hydroxide or potassium hydroxide; the molar ratio of the base to dimethyl succinylsuccinate is 3.0:1 to 5.0:1.

[0016] Preferably, the disubstituted arylamino terephthalic acid is 2,5-diphenylamino terephthalic acid or 2,5-bis(p-toluidino)terephthalic acid or 2,5-bis(p-chloroanilino)terephthalic acid or 2,5-bis(o-chloroanilino)terephthalic acid or 2,5-bis(m-chloroanilino)terephthalic acid.

[0017]

[0018] Preferably, in the co-cyclization reaction of step (2), the mass ratio of the intermediate 2,5-disubstituted arylamino terephthalic acid to 2,5-bis((2-oxo-2,3-dihydro-1H-benzo[d]imidazol-5-yl)amino)terephthalic acid is 10:90 to 90:10.

[0019] Preferably, the mass ratio of the classical quinacridone to the compound 1,3,6,9,11,14 - hexahydroimidazo[4’,5’:5,6]quinolino[3,2 - i]imidazo[4,5 - a]acridine - 2,8,10,16 - tetrone obtained by fusing quinacridone with benzimidazolone is 10:90 to 90:10.

[0020] Preferably, in the pigment manufacturing process, the liquid medium that does not dissolve the crude quinacridone solid solution is N,N - dimethylformamide, dimethyl sulfoxide, N - methylpyrrolidone, methanol, ethanol, propanol, butanol, etc.

[0021] Preferably, the pigment - forming heating temperature is above 70°C and below 150°C.

[0022] The present invention provides a manufacturing technology for quinacridone solid - solution pigments, and the coloring matter obtained by this technology has more excellent heat resistance than classical quinacridone pigments. Specific Embodiments

[0023] In the following examples, parts and percentages in each case are parts by mass and mass percentages. The examples are further descriptions of the present invention, but the protection scope of the present invention is not limited thereto.

[0024] Intermediate Preparation:

[0025] Example A:

[0026] ① In a dry reaction kettle, 480 parts of industrial ethanol, 80 parts of dimethyl succinylsuccinate, 101.3 parts of 5 - aminobenzimidazolone are added, 6.9 parts of 37% concentrated hydrochloric acid is added, the temperature is raised to reflux, reflux for 8 hours, cooled, filtered, and washed to obtain dimethyl 2,5 - bis((2 - oxo - 2,3 - dihydro - 1H - benzo[d]imidazol - 5 - yl)amino)terephthalate.

[0027] ② In a dry reaction kettle, 480 parts of industrial ethanol, the intermediate filter cake obtained in the previous step is added, stirred for 30 minutes, 87 parts of sodium m - nitrobenzenesulfonate is added, and 157 parts of 50% potassium hydroxide solution is added. The temperature is raised to reflux, reflux for 8 hours, and 2000 parts of water is added after cooling. The mother liquor is filtered, the pH is adjusted to 2.0 with about 300 parts of 30% sulfuric acid, filtered, and the filter cake is obtained. Dried and pulverized to obtain 142 parts of 2,5 - bis((2 - oxo - 2,3 - dihydro - 1H - benzo[d]imidazol - 5 - yl)amino)terephthalic acid, with a yield of 88% and a liquid - phase chromatographic content of 98.7%.

[0028] Example B:

[0029] ① In a dry reaction kettle, add 480 parts of industrial ethanol, 80 parts of dimethyl succinylsuccinate, 106.5 parts of 5-aminobenzimidazolone, and 6.9 parts of 37% concentrated hydrochloric acid. Heat up to reflux and reflux for 8 hours. Cool down, filter by suction, and wash to obtain dimethyl 2,5-bis((2-oxo-2,3-dihydro-1H-benzo[d]imidazol-5-yl)amino)terephthalate.

[0030] ② In a dry reaction kettle, add 480 parts of industrial ethanol, the intermediate filter cake obtained in the previous step, and 157 parts of 50% potassium hydroxide solution. Heat up to reflux and reflux for 8 hours. Cool down and add 2000 parts of water. Filter to obtain the mother liquor, adjust the pH to 2.0 with about 300 parts of 30% sulfuric acid, filter, and obtain the filter cake. Dry and crush to obtain 145.2 grams of 2,5-bis((2-oxo-2,3-dihydro-1H-benzo[d]imidazol-5-yl)amino)terephthalic acid, with a yield of 90.05% and a liquid chromatography content of 99.1%.

[0031] Pigment preparation:

[0032] Example 1

[0033] Add 240 parts of polyphosphoric acid containing 117.5% to the reaction kettle quantitatively, start stirring, and then add 4 parts of 2,5-((2-oxo-2,3-dihydro-1H-benzo[d]imidazol-5-yl)amino)terephthalic acid and 36 parts of 2,5-bis(p-tolyl)-terephthalic acid at 90 - 100 °C. After adding the materials, heat up to 130 °C and keep the temperature for 3 hours. After the heat preservation, slowly add this material into 1000 parts of ice water at 0 °C - 5 °C. After the addition, stir for 3 hours, filter and wash with water to obtain a crude solid solution water-containing filter cake. Then add the crude solid solution water-containing filter cake to 500 parts of N,N-dimethylformamide, beat for 1 hour, heat up to reflux, and reflux for 8 hours. Cool down, filter, wash with water, and dry to obtain 36 parts of the solid solution finished product.

[0034] Comparative Example 1

[0035] Add 240 parts of polyphosphoric acid containing 117.5% to the reaction kettle quantitatively, start stirring, and then add 40 parts of 2,5-bis(p-tolyl)-terephthalic acid at 90 - 100 °C. After adding the materials, heat up to 130 °C and keep the temperature for 3 hours. After the heat preservation, slowly add this material into 1000 parts of ice water at 0 °C - 5 °C. After the addition, stir for 3 hours, filter and wash with water to obtain a closed-loop filter cake. Then add the closed-loop filter cake to 500 parts of N,N-dimethylformamide, beat for 1 hour, heat up to reflux, and reflux for 8 hours. Cool down, filter, wash with water, and dry to obtain 36 parts of pure Pigment Red 122 finished product.

[0036] Example 2

[0037] Quantitatively add 240 parts of polyphosphoric acid containing 117.5% into the reaction kettle, start stirring, and then add 16 parts of 2,5-((2-oxo-2,3-dihydro-1H-benzo[d]imidazol-5-yl)amino)terephthalic acid and 24 parts of 2,5-bis(p-tolyl)terephthalic acid at 90 - 100 °C. After the feeding is completed, raise the temperature to 130 °C and keep the temperature for 3 hours. After the heat preservation is completed, slowly add this material into 1000 parts of ice water at 0 °C - 5 °C. After the material addition is completed, stir for 3 hours, filter and wash with water to obtain a crude solid solution hydrated filter cake. Then add the crude solid solution hydrated filter cake to 500 parts of N,N-dimethylformamide, beat for 1 hour, raise the temperature to reflux, and reflux for 8 hours. Cool down, filter, wash with water, and dry to obtain 36 parts of the finished solid solution product.

[0038] Example 3

[0039] Quantitatively add 240 parts of polyphosphoric acid containing 117.5% into the reaction kettle, start stirring, and then add 8 parts of 2,5-bis((2-oxo-2,3-dihydro-1H-benzo[d]imidazol-5-yl)amino)terephthalic acid and 32 parts of 2,5-bis(p-tolyl)terephthalic acid at 90 - 100 °C. After the feeding is completed, raise the temperature to 130 °C and keep the temperature for 3 hours. After the heat preservation is completed, slowly add this material into 1000 parts of ice water at 0 °C - 5 °C. After the material addition is completed, stir for 3 hours, filter and wash with water to obtain a crude solid solution hydrated filter cake. Then add the crude solid solution hydrated filter cake to 500 parts of dimethyl sulfoxide, beat for 1 hour, raise the temperature to reflux, and reflux for 8 hours. Cool down, filter, wash with water, and dry to obtain 36 parts of the finished solid solution product.

[0040] Example 4

[0041] Quantitatively add 240 parts of polyphosphoric acid containing 117.5% into the reaction kettle, start stirring, and then add 24 parts of 2,5-bis((2-oxo-2,3-dihydro-1H-benzo[d]imidazol-5-yl)amino)terephthalic acid and 16 parts of 2,5-bis(p-tolyl)terephthalic acid at 90 - 100 °C. After the feeding is completed, raise the temperature to 130 °C and keep the temperature for 3 hours. After the heat preservation is completed, slowly add this material into 1000 parts of ice water at 0 °C - 5 °C. After the material addition is completed, stir for 3 hours, filter and wash with water to obtain a crude solid solution hydrated filter cake. Then add the crude solid solution hydrated filter cake to 500 parts of N-methylpyrrolidone, beat for 1 hour, raise the temperature to reflux, and reflux for 8 hours. Cool down, filter, wash with water, and dry to obtain 36 parts of the finished solid solution product.

[0042] The method for testing the temperature resistance of PP is as follows:

[0043]

[0044] ② Mixing and granulation: After the above materials are accurately weighed, they are extruded and granulated by a twin-screw extruder, and then drawn into masterbatch (about 1300 grams)

[0045] ③ Test: Use SSF-III injection molding machine to do temperature resistance test, the starting temperature of the injection molding machine is set to 200℃, 20℃ as a step, and do a step experiment. At the same time, stay at this temperature for 5 minutes before injection molding, and then take the middle 4 injection molding pieces at each temperature, and then clean the machine with PP particles, and heat it to the next temperature at the same time. Stay at the set temperature for 20 minutes before experimenting, the purpose is to ensure the temperature uniformity of each heating zone of the injection molding machine, and keep heating up to 320℃.

[0046] ④ Result test: Taking the injection molding result at 200℃ as the standard, use a colorimeter to test the color difference ΔE at various temperatures. The ΔE value not exceeding 3.0 is the highest temperature resistance temperature of the pigment.

[0047] The test results of the embodiment are shown in Table 1 below:

[0048] Table 1

[0049] ΔE(260 °C) ΔE(280 °C) ΔE(300 °C) ΔE(320 °C) Example 1 0.9 1.1 1.9 2.8 Comparative Example 1 2.3 2.9 5.6 10.9 Example 2 1.0 1.1 1.5 2.6 Example 3 0.8 1.0 1.3 2.3 Example 4 0.9 1.2 1.8 2.5

[0050] As can be seen from the comparison of Example 1, Example 2, Example 3, Example 4 with Comparative Example 1, the quinacridone solid solution formed by the disubstituted quinacridone and 1,3,6,9,11,14-hexahydroimidazo[4',5':5,6]quinolino[3,2-i]imidazo[4,5-a]acridine-2,8,10,16-tetraone has significantly better heat resistance in plastics than the classic quinacridone pigment.

[0051] The temperature resistance test method in coatings is as follows:

[0052] ①Proportion:

[0053] Acrylic resin liquid (H-304) 184g

[0054] Pigment 16g

[0055] Glass beads (Φ2-3mm) 200g

[0056] ② Grinding and plate making: After the above materials are accurately weighed, they are shaken and ground in a box shaker SK450 (FM company) for 1 hour, filtered to remove the glass beads, and then sprayed on the tinplate and dried at 120℃ for 30 minutes to obtain the colored plate.

[0057] ③ Test: The above coloring plates were respectively placed in a stepwise temperature-rising oven and baked at 140°C, 160°C, 180°C, 200°C, 220°C, and 240°C for 30 minutes each. After taking them out and cooling for 1 hour, they were used for testing. The color change was compared with the reference plate baked at 120°C for 30 minutes, and the color difference ΔE at each temperature was measured with a colorimeter (Datacolor 3000). The highest heat-resistant temperature of the pigment for this coating system was when ΔE did not exceed 2.0.

[0058] The test results of the examples are shown in Table 2 below:

[0059] Table 2

[0060]

[0061]

[0062] As can be seen from the comparison between Example 1, Example 2, Example 3, Example 4 and Comparative Example 1, the quinacridone solid solution formed by disubstituted quinacridone and 1,3,6,9,11,14-hexahydroimidazo[4’,5’:5,6]quinolino[3,2-i]imidazo[4,5-a]acridine-2,8,10,16-tetrone has significantly better heat resistance in coatings compared with classical quinacridone pigments.

Claims

1. A quinacridone solid solution pigment, calculated by mass percentage, comprising: 10% - 90% of a disubstituted quinacridone having the structural formula (1), and 10% - 90% of 1,3,6,9,11,14 - hexahydroimidazo[4’,5’:5,6]quinolino[3,2 - i]imidazo[4,5 - a]acridine - 2,8,10,16 - tetrone having the structural formula (2); 2. A method for preparing the quinacridone solid solution pigment according to claim 1, comprising the following steps: (1) Synthesis process of intermediate 2,5-bis((2-oxo-2,3-dihydro-1H-benzo[d]imidazol-5-yl)amino)terephthalic acid (Formula 4): In an alcohol solvent system, 5-amino-benzimidazolone and dimethyl succinylsuccinate are condensed under acid catalysis to obtain dimethyl 2,5-bis((2-oxo-2,3-dihydro-1H-benzo[d]imidazol-5-yl)amino)terephthalate. Dimethyl 2,5-bis((2-oxo-2,3-dihydro-1H-benzo[d]imidazol-5-yl)amino)terephthalate undergoes oxidative hydrolysis reaction in an alcohol solvent under the action of m-nitrobenzenesulfonic acid and a base, and then is acidified to obtain 2,5-bis((2-oxo-2,3-dihydro-1H-benzo[d]imidazol-5-yl)amino)terephthalic acid of Formula (4); (2) Manufacturing process of crude quinacridone solid solution: In polyphosphoric acid, 2,5-disubstituted arylamino terephthalic acid (Formula 3) and 2,5-bis((2-oxo-2,3-dihydro-1H-benzo[d]imidazol-5-yl)amino)terephthalic acid (Formula 4) are subjected to co-cyclization reaction to obtain a crude quinacridone solid solution water-containing filter cake of disubstituted quinacridone (Formula 1) and 1,3,6,9,11,14-hexahydroimidazo[4’,5’:5,6]quinolino[3,2-i]imidazo[4,5-a]acridine-2,8,10,16-tetrone (Formula 2); (3) Pigment process: The obtained crude quinacridone solid solution water-containing filter cake is heated in a liquid medium that does not dissolve the crude quinacridone solid solution 3. The method for preparing a quinacridone solid solution pigment according to claim 2, characterized in that: Specifically, in step (1), dimethyl succinylsuccinate and 5 - aminobenzimidazolone are condensed in ethanol under the catalysis of hydrochloric acid. The filter cake is separated and then undergoes an oxidative hydrolysis reaction with sodium m - nitrobenzenesulfonate and a base in ethanol, followed by acid precipitation, washing with water, drying, and pulverization to obtain the intermediate 2,5 - bis((2 - oxo - 2,3 - dihydro - 1H - benzo[d]imidazol - 5 - yl)amino)terephthalic acid.

4. The method for preparing a quinacridone solid solution pigment according to claim 3, characterized in that: The molar ratio of 5 - aminobenzimidazolone to dimethyl succinylsuccinate is 2.14:1 to 2.30:1, the molar ratio of hydrochloric acid to dimethyl succinylsuccinate is 0.05:1 to 0.20:1, and the molar ratio of sodium m - nitrobenzenesulfonate to dimethyl succinylsuccinate is 0.95:1 to 1.20:

1.

5. The method for preparing a quinacridone solid solution pigment according to claim 3, characterized in that: The base is sodium hydroxide or potassium hydroxide; the molar ratio of the base to dimethyl succinylsuccinate is 3.0:1 to 5.0:

1.

6. The method for preparing a quinacridone solid solution pigment according to claim 2, characterized in that: In the co - cyclization reaction of step (2), the mass ratio of the intermediate 2,5 - disubstituted arylamino terephthalic acid to 2,5 - bis((2 - oxo - 2,3 - dihydro - 1H - benzo[d]imidazol - 5 - yl)amino)terephthalic acid is 10:90 to 90:

10.

7. The method for preparing a quinacridone solid solution pigment according to claim 2, characterized in that: In step (2), the mass ratio of the classical quinacridone to the compound 1,3,6,9,11,14 - hexahydroimidazo[4’,5’:5,6]quinolino[3,2 - i]imidazo[4,5 - a]acridine - 2,8,10,16 - tetrone in which quinacridone and benzimidazolone are fused is 10:90 to 90:

10.

8. The method for preparing a quinacridone solid solution pigment according to claim 2, characterized in that: In step (2), the 2,5 - disubstituted arylamino terephthalic acid is 2,5 - diphenylamino terephthalic acid, 2,5 - bis(p - tolylamino)terephthalic acid, 2,5 - bis(p - chloroanilino)terephthalic acid, 2,5 - bis(o - chloroanilino)terephthalic acid, or 2,5 - bis(m - chloroanilino)terephthalic acid.

9. The method for preparing a quinacridone solid solution pigment according to claim 2, characterized in that: In step (3), the liquid medium that does not dissolve the crude quinacridone solid solution is N,N - dimethylformamide, dimethyl sulfoxide, N - methylpyrrolidone, methanol, ethanol, propanol, or butanol.

10. The method for preparing a quinacridone solid solution pigment according to claim 2, characterized in that: In step (3), the heating temperature is above 70°C and below 150°C.

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