CN109504119B

CN109504119B - Black pigment and preparation method and application thereof

Info

Publication number: CN109504119B
Application number: CN201710833582.5A
Authority: CN
Inventors: 史利斌
Original assignee: Huzhou Juli New Material Technology Co ltd
Current assignee: Huzhou Juli New Material Technology Co ltd
Priority date: 2017-09-15
Filing date: 2017-09-15
Publication date: 2020-09-08
Anticipated expiration: 2037-09-15
Also published as: CN109504119A

Abstract

The invention discloses a black pigment and a preparation method and application thereof. The pigment does not contain heavy metal element chromium and contains aluminum, and the content of the aluminum element is 0.5-20 wt% based on the total weight of the pigment.

Description

Black pigment and preparation method and application thereof

Technical Field

The invention relates to an organic pigment, in particular to a black pigment taking aniline as a raw material, a preparation method and application thereof.

Background

The pigment or dye synthesized by using ANILINE as main raw material is generally called ANILINE BLACK (ANILINE BLACK), and the ANILINE BLACK related to the invention is an ANILINE polymer, belonging to organic pigments, wherein one of the ANILINE polymer isThe species commonly referred to as "nigrosine No. 1" (Chinese name: c.l. pigment Black 1, English name: ANILINE BLACK, cas accession # 13007-86-8, formula C₆₆H₅₁N₁₁Cr₃O₁₂The structural formula is shown in the following formula II), and the pigment contains hexavalent chromium, can be called chromium-containing aniline black, and has high blackness and blue hue.

Nigrosine No. 1 has effects which cannot be achieved by other black pigments such as carbon black and the like in many application occasions, however, dichromate is usually used as an initiator in the synthesis process, a large amount of chromium-containing wastewater generated in the production process is difficult to treat, serious pollution is brought to water and soil, a large amount of chromium (6-valent chromium) is also contained in the product structure, the mass percentage of the chromium is more than 20%, and great health risks are brought to human bodies, so that the application of nigrosine is limited in many occasions.

In the prior method for preparing nigrosine without dichromate, persulfate, chlorate, hydrogen peroxide or other oxidants are adopted, and chloride ions are paired on a molecular chain (acting with amino and imino) in a form of counter anions in the polymerization process. If chloride ions are not removed, the obtained product is a dark green product, and a large amount of the product is agglomerated and cannot be dispersed, so that the product cannot be used as a pigment; after the chloride ions are removed, the intermolecular hydrogen bonding action is weakened, and the dispersion is easy, but as the proton on the nitrogen atom is lost, the conjugation effect of the whole molecular chain is weakened, the absorption capacity to visible light is reduced, the blackness value of the obtained product is not high, the hue is brown, and the product cannot be compared with chromium-containing nigrosine at all and cannot meet the use requirement.

Therefore, there is a strong need in the art to provide a black organic pigment which does not use dichromate in the synthesis process, does not contain harmful substances such as chromium in the product structure, and has the blackness and very blue hue of the conventional nigrosine No. 1.

Disclosure of Invention

The invention aims to provide a novel black organic pigment and a preparation method thereof, wherein the novel black organic pigment has high blackness and blue hue and belongs to an environment-friendly product.

In a first aspect of the invention, a black pigment is provided, the structure of which comprises a structural formula shown as a formula I, wherein aluminum is contained, but heavy metal element chromium is not contained; based on the total weight of the pigment, the content of the aluminum element is 0.5 to 20 weight percent; preferably 2 to 15 wt%; more preferably 3 to 10 wt%;

in another preferred example, the pigment has a Color specification index (Color specification index) L (×) value of not higher than 10.0; preferably not higher than 8.0; more preferably not higher than 6.0.

In a second aspect of the present invention, there is provided a method for preparing the black pigment provided by the present invention as described above, the method comprising the steps of: the aniline acid salt, the aluminum salt and the oxidant are mixed and react to obtain the black pigment provided by the invention.

In another preferred embodiment, the aniline acid salt is obtained by mixing aniline with an aqueous solution containing an inorganic acid or an organic acid; the inorganic acid comprises hydrochloric acid and sulfuric acid; the organic acid comprises benzenesulfonic acid and benzenesulfonic acid derivatives.

In another preferred example, the method comprises the steps of: adding aniline into an aqueous solution containing acid to generate an aniline acid salt solution, adding a catalyst and aluminum salt to obtain a mixed solution, then adding an oxidant to perform oxidative polymerization to obtain a polymerization product, neutralizing with an alkali solution, filtering, washing with water, and drying to obtain the black pigment provided by the invention.

In another preferred embodiment, the aluminum salt is a water-soluble aluminum salt; the aluminum salt is preferably selected from aluminum sulfate, aluminum chloride, or hydrates thereof.

In another preferred example, the oxidant comprises persulfate, chlorate and hydrogen peroxide; the catalyst of the reaction is inorganic salt or biological enzyme which can promote the decomposition of the oxidant; the inorganic salt is selected from iron salt or copper salt.

In another preferred embodiment, the temperature of the reaction is 10-60 ℃; the reaction time is 2-6 hours.

In a third aspect of the present invention, there is provided a use of the black pigment provided by the present invention as described above.

Accordingly, the present invention provides a black organic pigment which does not use dichromate in the synthesis process, does not contain harmful substances such as chromium in the product structure, and has the blackness and very blue hue of the existing nigrosine No. 1.

Drawings

FIG. 1 shows the results of elemental analysis and infrared analysis of the organic black pigment 1 obtained in example 1; wherein A is an infrared spectrum and B is an EDS elemental analysis spectrum and corresponding data.

FIG. 2 shows the results of elemental analysis and infrared analysis of the organic black pigment 2 obtained in example 2; wherein A is an infrared spectrum and B is an EDS elemental analysis spectrum and corresponding data.

FIG. 3 shows the results of elemental analysis and infrared analysis of the organic black pigment 3 obtained in example 3; wherein A is an infrared spectrum and B is an EDS elemental analysis spectrum and corresponding data.

FIG. 4 shows the results of elemental analysis and infrared analysis of nigrosine obtained in comparative example 1; wherein A is an infrared spectrum and B is an EDS elemental analysis spectrum and corresponding data.

FIG. 5 shows the results of elemental analysis and infrared analysis of nigrosine obtained in comparative example 2; wherein A is an infrared spectrum and B is an EDS elemental analysis spectrum and corresponding data.

FIG. 6 shows the results of elemental analysis and infrared analysis of nigrosine obtained in comparative example 3; wherein A is an infrared spectrum and B is an EDS elemental analysis spectrum and corresponding data.

FIG. 7 shows the results of elemental analysis and infrared analysis of nigrosine obtained in comparative example 4; wherein A is an infrared spectrum and B is an EDS elemental analysis spectrum and corresponding data.

Detailed Description

The inventors have made extensive and intensive studies and have found that an organic black pigment which contains an aluminate group and has a basic structure represented by the formula I, but does not contain chromium as a heavy metal element. The blackness of the organic black pigment provided by the invention is similar to that of nigrosine No. 1 with the structure shown in a formula II. On the basis of this, the present invention has been completed.

Organic black pigments

The invention provides an organic black pigment, which belongs to aniline polymer and contains a structure shown as a formula I and aluminate, wherein the mass percent of aluminum is 0.5-20 wt%; preferably 2 to 15 wt%; more preferably 3 to 10 wt%.

The organic black pigment provided by the invention does not contain heavy metal elements, including chromium, wherein the chromium comprises hexavalent chromium.

The organic black pigment provided by the invention has high blackness, and the color specification index (Colorspecification index) L (#) value is not higher than 10.0; preferably not higher than 8.0; more preferably not higher than 6.0.

The organic black pigment provided by the invention is generally in a powder state and insoluble in any solvent, including but not limited to water, organic solvents and the like.

Preparation method

The preparation method of the organic black pigment provided by the invention comprises the following steps:

a first step of mixing an aqueous solution containing an acid, aniline, a catalyst and an aluminum salt to obtain a solution 1;

and secondly, mixing the solution 1 with an aqueous solution containing an oxidant, and carrying out oxidative polymerization reaction to obtain the organic black pigment provided by the invention.

In one embodiment of the present invention, the first step is to add aniline to an aqueous solution containing an acid to obtain an aniline acid salt mixture, and then mix the aniline acid salt mixture with a catalyst and an aluminum salt.

In one embodiment of the present invention, the first step is to add aniline to an aqueous solution containing acid to obtain an aniline acid salt mixture, then add the catalyst, add aluminum salt, and mix until all is dissolved.

In the first step, the acid may be an inorganic acid or an organic acid. In a preferred embodiment of the invention, the acids are hydrochloric acid and sulfuric acid.

In the first step, the catalyst may be an inorganic salt such as an iron salt or a copper salt, or a substance which can promote the decomposition of the oxidizing agent such as a biological enzyme. In a preferred embodiment of the present invention, the catalyst comprises ferrous chloride.

In the first step, the aluminum salt may be aluminum sulfate and its hydrate, aluminum chloride and its hydrate, or other soluble aluminum salts.

The mixing of the first step described above is carried out at room temperature. As used herein, "room temperature" means 10-30 deg.C, preferably 15-25 deg.C.

In one embodiment of the present invention, the second step is to add an aqueous solution containing an oxidizing agent to the solution 1 obtained in the first step; the process of adding the aqueous solution containing the oxidant can be one-time addition or can be carried out in a slow dropwise manner. In a preferred embodiment of the invention, the addition is carried out at 0-60 ℃, more preferably at a temperature not exceeding 30 ℃. In the present example, the above-mentioned second step is carried out at 0 to 60 ℃ and preferably not more than 30 ℃ and, after adding an aqueous solution containing an oxidizing agent to the solution 1 obtained in the first step, the reaction is stirred at 60 to 80 ℃ and preferably at 70 ℃ for 2 to 6 hours and preferably 2.5 to 4 hours.

In one embodiment of the present invention, the second step is performed by filtering after the reaction is completed, dispersing the obtained filter cake in water, adjusting the pH of the obtained filter cake to 7-9 (preferably to 7-8) with alkali, filtering, drying (for example, but not limited to, 105-. The base used may be sodium hydroxide, aqueous ammonia, etc., as well as some lewis bases.

The oxidant in the second step may be persulfate, chlorate (for example, but not limited to, sodium chlorate), hydrogen peroxide (for example, but not limited to, 30% hydrogen peroxide), or a mixture of several oxidants.

Use of

The organic black pigments provided by the present invention have a wide range of applications, such as, but not limited to, blacking by dispersion in resins. Concretely, the color paste is added into polyurethane resin, acrylic resin and other resins to prepare black color paste, printing ink and paint, so that the color paste is used for surface coloring, printing, piano paint, automobile paint and the like of leather; can also be used for coloring ABS plastics, PE plastics and the like.

The organic black pigment provided by the invention has no absorption and shielding effect on ultraviolet rays, and the carbon black has a shielding effect on the ultraviolet rays, so that the UV ink curing is influenced.

The features mentioned above with reference to the invention, or the features mentioned with reference to the embodiments, can be combined arbitrarily. All the features disclosed in this specification may be combined in any combination, and each feature disclosed in this specification may be replaced by alternative features serving the same, equivalent or similar purpose. Thus, unless expressly stated otherwise, the features disclosed are merely generic examples of equivalent or similar features.

The main advantages of the invention are:

1. the organic black pigment provided by the invention has excellent blackness and color light, and can completely match with the prior chromium-containing products.

2. The organic black pigment product provided by the invention does not contain harmful elements such as chromium and the like in the structure, is an environment-friendly pigment, can eliminate the harm of chromium to the environment in the production process, and eliminates the potential health risk of the product to human bodies.

3. The organic black pigment provided by the invention does not need to use dichromate in the synthesis process.

4. The organic black pigment provided by the invention does not contain harmful elements such as heavy metals and the like, and the application field breaks through the limitation of chromium-containing products, and can be used in various occasions requiring high blackness and high brightness.

The invention will be further illustrated with reference to the following specific examples. It should be understood that these examples are for illustrative purposes only and are not intended to limit the scope of the present invention. The experimental procedures, in which specific conditions are not noted in the following examples, are generally carried out according to conventional conditions or according to conditions recommended by the manufacturers. All percentages, ratios, proportions, or parts are by weight unless otherwise specified. The weight volume percentage units in the present invention are well known to those skilled in the art and refer to, for example, the weight of solute in a 100 ml solution. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. In addition, any methods and materials similar or equivalent to those described herein can be used in the methods of the present invention. The preferred embodiments and materials described herein are intended to be exemplary only.

Example 1

Preparation of organic Black pigment 1

15g (0.15mol) of 36% hydrochloric acid and 3g (0.03mol) of 98% sulfuric acid are added into 150ml of aqueous solution, 14g (0.15mol) of aniline is added, the mixture is stirred at a constant speed for 20 minutes at room temperature, 1g (0.005mol) of ferrous chloride and 4g (0.017mol) of aluminum chloride are added in sequence, after all the components are dissolved, 80g (0.3mol) of 40% aqueous sodium chlorate solution is added at one time at 30 ℃, the mixture is stirred and reacted for 3 hours at 70 ℃, and the reaction is finished. After the reaction is finished, the reaction solution is filtered and washed, the obtained filter cake is dispersed by 300ml of water, the pH value is neutralized to 7.5 by ammonia water, then the filter cake is filtered and washed, and the filter cake is dried and crushed at 120 ℃ to obtain the organic black pigment 1 provided by the invention.

Elemental analysis and infrared analysis were performed on the obtained organic black pigment 1, and changes in the aluminum content and characteristic peak were confirmed. The results are shown in FIG. 1, Table 1 and Table 2. The elemental analysis results showed that the sample was not washed sufficiently with water and was doped with sodium chloride or sodium sulfate.

Example 2

Preparation of organic Black pigment 2

15g (0.15mol) of 36% hydrochloric acid and 3g (0.03mol) of 98% sulfuric acid are added into 150ml of an aqueous solution, 14g (0.15mol) of aniline is added, the mixture is stirred at a constant speed for 20 minutes at room temperature, 1g (0.005mol) of ferrous chloride and 8g (0.033mol) of aluminum chloride are added in sequence, after all the ferrous chloride and the aluminum chloride are dissolved, 80g (0.3mol) of 40% aqueous sodium chlorate solution is added at one time at 30 ℃, the mixture is stirred and reacted for 3 hours at 70 ℃, and the reaction is finished. After the reaction is finished, the reaction solution is filtered and washed, the obtained filter cake is dispersed by 300ml of water, the pH value is neutralized to 7.5 by ammonia water, then the filter cake is filtered and washed, and the filter cake is dried and crushed at 120 ℃ to obtain the organic black pigment 2 provided by the invention.

Elemental analysis and infrared analysis were performed on the obtained organic black pigment 2, and the change in the aluminum content and characteristic peak was confirmed. The results are shown in FIG. 2, Table 1 and Table 2.

Example 3

Preparation of organic Black pigment 3

Adding 15g (0.15mol) of 36% hydrochloric acid and 3g (0.03mol) of 98% sulfuric acid into 200ml of aqueous solution, then adding 14g (0.15mol) of aniline, stirring at a constant speed for 20 minutes at room temperature, then adding 1g (0.005mol) of ferrous chloride and 12g (0.049mol) of aluminum chloride in sequence, after all the materials are dissolved, dropwise adding 35g (0.31mol) of 30% hydrogen peroxide at 30 ℃, stirring and reacting for 3 hours at 70 ℃ after the dropwise adding is completed, and finishing the reaction. After the reaction, the reaction solution was filtered, washed with water, the resulting filter cake was dispersed with 300ml of water, neutralized with ammonia water to pH7.5, and then filtered and washed with water, the filter cake was dried at 120 ℃ and pulverized to obtain organic black pigment 3.

Elemental analysis and infrared analysis were performed on the obtained organic black pigment 2, and the change in the aluminum content and characteristic peak was confirmed. The results are shown in FIG. 3, Table 1 and Table 2.

Comparative example 1 (without using aluminum salt)

Adding 15g (0.15mol) of 36% hydrochloric acid and 3g (0.03mol) of 98% sulfuric acid into 200ml of water solution, then adding 14g (0.15mol) of aniline, stirring at a constant speed for 20 minutes at room temperature, then adding 1g (0.005mol) of ferrous chloride, dripping 35g (0.31mol) of 30% hydrogen peroxide at 30 ℃ after completely dissolving, stirring and reacting for 3 hours at 70 ℃ after dripping is completed, filtering reaction liquid after reaction is completed, washing with water, dispersing the obtained filter cake with 300ml of water, neutralizing with ammonia water to pH7.5, then filtering and washing with water, drying and crushing the filter cake at 120 ℃ to obtain aniline black.

The obtained nigrosine was subjected to elemental analysis and infrared analysis to confirm the change in the elemental content and characteristic peak. The results are shown in FIG. 4, Table 1 and Table 2.

Comparative example 2 (use of copper sulfate instead of aluminum chloride)

Adding 15g (0.15mol) of 36% hydrochloric acid and 3g (0.03mol) of 98% sulfuric acid into 200ml of water solution, then adding 14g (0.15mol) of aniline, stirring at a constant speed for 20 minutes at room temperature, then adding 1g (0.005mol) of ferrous chloride and 5g (0.02mol) of copper sulfate in sequence, dropwise adding 35g (0.31mol) of 30% hydrogen peroxide at 30 ℃ after completely dissolving, stirring at 70 ℃ for reacting for 3 hours after dropwise adding is completed, and finishing the reaction. After the reaction, the reaction solution was filtered, washed with water, the resulting filter cake was dispersed with 300ml of water, neutralized with ammonia water to pH7.5, then filtered and washed with water, the filter cake was dried at 120 ℃ and pulverized to obtain nigrosine.

The obtained nigrosine was subjected to elemental analysis and infrared analysis to confirm the change in the elemental content and characteristic peak. The results are shown in FIG. 5, Table 1 and Table 2.

Comparative example 3 (use of Zinc chloride instead of aluminum chloride)

Adding 15g (0.15mol) of 36% hydrochloric acid and 3g (0.03mol) of 98% sulfuric acid into 200ml of aqueous solution, then adding 14g (0.15mol) of aniline, stirring at a constant speed for 20 minutes at room temperature, then adding 1g (0.005mol) of ferrous chloride and 4.5g (0.03mol) of zinc chloride in sequence, dropwise adding 35g (0.31mol) of 30% hydrogen peroxide at 30 ℃ after completely dissolving, stirring at 70 ℃ for reacting for 3 hours after dropwise adding is completed, and finishing the reaction. After the reaction, the reaction solution was filtered, washed with water, the resulting filter cake was dispersed with 300ml of water, neutralized with ammonia water to pH7.5, then filtered and washed with water, the filter cake was dried at 120 ℃ and pulverized to obtain nigrosine.

The obtained nigrosine was subjected to elemental analysis and infrared analysis to confirm the change in the elemental content and characteristic peak. The results are shown in FIG. 6, Table 1 and Table 2.

Comparative example 4

Chromium-containing nigrosine purchased from Tokyo color materials, Japan was subjected to elemental analysis and infrared analysis. The results are shown in FIG. 7, Table 1 and Table 2.

TABLE 1 elemental analysis results (EDS) of each sample

Note: nitrogen and oxygen values are only used as references due to inaccuracies in the EDS analysis of light elements

TABLE 2 characteristic IR absorption Peak position for each sample

The infrared spectrum data results of the products obtained in the above examples and comparative examples show that the characteristic peaks of the products are substantially identical (the individual peaks become insignificant due to the enhancement of adjacent peaks), and the main structures of the molecules are proved to be identical.

The blackness of the products obtained in the above examples and comparative examples was compared. The pigment dispersion into the same resin is compared, and the test is carried out by a spectrophotometer, and the evaluation is mainly carried out by the measured color specification index (L value), and the lower the L value is, the higher the blackness is, and the evaluation is also combined with a visual method under the same condition.

The specific contents are as follows:

the instrument comprises the following steps: a full-automatic vibration type mixer (Zhengzhou Sanhua technology industries, Ltd.);

aimari multi-angle spectrophotometer (model MA98)

The method comprises the following steps: 20g of the sample obtained in the above examples and comparative examples were added to 70g (solids content: 50%) of a hydroxyacrylic resin, 20g of a solvent (s 100: propylene glycol methyl ether acetate 1:1) was added, 110g (1mm) of zirconium beads were further added, the mixture was shaken in a fully automatic shaking type kneader for 2 hours, filtered, and the color paste fineness was 15 μm, and the mixture was coated on a white cardboard with a 60 μm wire bar, and then dried at 60 ℃ and measured with a spectrophotometer, and the L value was obtained with a D65 light source, a 10 ℃ observation angle and a 45 ℃ incident angle. The results are shown in Table 3.

TABLE 3

Sample (I)	Characteristics of elements	pH of the powder	L*	Visual color
					Example 1	2.84 percent of aluminum	6.5	6.65	Dark black, exhibiting blue light
Example 2	6 percent of aluminum	6.5	5.69	Dark black, exhibiting blue light
					Example 3	8.78 percent of aluminum	6.7	3.84	Dark black, exhibiting blue light
Comparative example 1	2.51 percent of iron	6.7	13.5	Black, grayish and brown
					Comparative example 2	4.48 percent of copper	6.5	11.3	Black, grayish and brown
Comparative example 3	9.5 percent of zinc	6.7	12.0	Black, grayish and brown
					Comparative example 4	29.2 percent of chromium	4.5	4.55	Dark black, exhibiting blue light

The L values for example 1, example 2 and example 3 are significantly lower than for comparative examples 1,2,3 and are closer to the values for comparative example 4.

As a result, the inventors have found that the organic black pigment synthesized by creatively introducing an aluminum salt into the synthesis has a very high blackness value and a bluish hue, and is completely comparable to chromium-containing nigrosine.

Meanwhile, the nigrosine synthesis by using copper salt and zinc salt can not improve the blackness of the product.

Iron is partially bonded on a molecular chain as a catalyst, but the bonding amount of iron is relatively small, and the phenomena of improving blackness and changing color light are not seen. Copper can be bonded on the molecular chain, so that the bonding amount is less, and the phenomena of improving the blackness and changing the color light are not seen. Zinc can also be combined on a molecular chain, and the phenomena of improving the blackness and changing the color light are not seen.

The foregoing is merely a preferred embodiment of the invention and is not intended to limit the scope of the invention, which is defined by the claims appended hereto, and any other technical entity or method that is encompassed by the claims as broadly defined herein, or equivalent variations thereof, is contemplated as being encompassed by the claims.

Claims

1. A black pigment, the structure includes the structural formula shown in formula I, characterized by that, does not contain heavy metal element chromium, contain aluminate, by the total weight of the pigment, the content of the aluminium element is 0.5-20 wt%;

2. the black pigment of claim 1, wherein the aluminum element is present in an amount of 2 to 15 wt%, based on the total weight of the pigment.

3. The black pigment of claim 1, wherein the aluminum element is present in an amount of 3 to 10 wt%, based on the total weight of the pigment.

4. The black pigment according to claim 1, wherein the pigment has an L (×) value of not higher than 10.0.

5. The black pigment according to claim 1, wherein the pigment has an L (×) value of not higher than 8.0.

6. The black pigment according to claim 1, wherein said pigment has an L (×) value of not higher than 6.0.

7. A process for preparing a black pigment according to any of claims 1 to 6, comprising the steps of: mixing aniline acid salt, aluminum salt, oxidant and catalyst, and reacting to obtain the black pigment of any one of claims 1-6;

the oxidant comprises persulfate, chlorate and hydrogen peroxide;

the aluminum salt is selected from aluminum sulfate, aluminum chloride, or hydrates thereof;

the catalyst of the reaction is inorganic salt or biological enzyme which can promote the decomposition of the oxidant;

the reaction temperature is 10-60 ℃; the reaction time is 2-6 hours.

8. The method of claim 7, wherein the inorganic salt is selected from iron or copper salts.

9. The method according to claim 7, wherein the aniline acid salt is obtained by mixing aniline with an aqueous solution containing an inorganic acid or an organic acid.

10. The method of claim 9, wherein the inorganic acid comprises hydrochloric acid, sulfuric acid; the organic acid is benzenesulfonic acid.

11. Use of a black pigment according to any of claims 1 to 6.