A modified self-dispersible pigment, its preparation method and use

Abstract

The application discloses a modified self-dispersible pigment and a preparation method thereof. The preparation method comprises the following steps: 5-20 parts of pigment particles, 1-10 parts of a dispersing agent and 80-95 parts of a first solvent are mixed and dispersed to obtain a pigment dispersion; the obtained pigment dispersion is prepared into a self-dispersible pigment by a spray drying method; 3-8 parts of the prepared self-dispersible pigment, 1-5 parts of a silane coupling agent and 80-100 parts of a second solvent are mixed and reacted at a certain temperature, and then modified self-dispersible pigment is obtained through centrifugation, washing and drying. The application further discloses an application of the modified self-dispersible pigment in polyamide in-situ polymerization color master batch. The method is simple, and the prepared modified self-dispersible pigment has good self-dispersing stability; the color master batch prepared by using the modified self-dispersible pigment has good dispersity and dyeing uniformity, and can improve coloring luster and coloring power.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of pigments and color masterbatch, and particularly relates to a modified self-dispersible pigment, a preparation method thereof, and application of the modified self-dispersible pigment in polyamide in-situ polymerization color masterbatch. BACKGROUND

[0002] Polyamide fibers have good wear resistance and high breaking strength, and are one of the most important synthetic fibers. Among them, PA6 and PA66 are most widely used. At present, weak acid dyes are mainly used for dyeing of polyamide fibers. The amino groups in the fibers form cations under acidic conditions, and the cations combine with the anions of ionized acid dyes in the aqueous solution through ionic bonds to dye the fabric. The aromatic polyamide fibers with good dyeing fastness and light fastness are obtained by combining the use of vat dyes or sulfur dyes during dyeing according to the Chinese patent with publication number CN103459710A. The composite material with excellent properties, moldability and productivity is obtained by impregnating benzene dimethylamine-based polyurethane resin with a molecular weight of 1000 or less into a fiber material according to the Japanese patent with publication number JP4894982B1. The molded product has excellent heat resistance, strength and low warping, thereby achieving the light weight of the product for use in various parts of electronic equipment and automobiles. However, compared with natural protein fibers such as wool and silk, polyamide fibers have high crystallinity, low amino content in the molecules and no macromolecular side chains, and the dyeing polyamide fibers have poor level dyeing, color depth and color fastness. More importantly, the traditional dyeing also has a series of problems such as serious environmental pollution and high energy consumption.

[0003] Color masterbatch is a special colorant for high polymer materials, which is generally composed of pigments, dispersants, carrier resins, additives and other components. The polyamide base is mixed with the colorant before spinning to obtain colored fibers, which is called the original solution dyeing method. This method saves the dyeing process of the fibers, has simple process and low cost, and can prepare high-quality original solution colored fibers while reducing the pollution problems caused by dyeing. It is a green and environmentally friendly dyeing technology and has broad development prospects. The Chinese patent with publication number CN107723831A discloses that the ester-soluble colorant is used as the colorant for polyester original solution dyeing, so that the colorant molecules are uniformly dispersed in the polyester polymer by controlling the occurrence of the polycondensation reaction of polyester oligomers with carrier aliphatic polyester polyols. The Chinese patent with publication number CN103255498A discloses that the liquid color paste is injected before entering the spinning box, and the polyester melt is mixed uniformly with the liquid color paste, and then melt direct spinning is carried out to prepare colored polyester fibers. The Chinese patent with publication number CN105420852A adds cyclodextrin and dye molecules before spinning, and uses the inclusion effect of cyclodextrin to fix the dyes in the cavity of cyclodextrin and blend with polyurethane.

[0004] Currently, the preparation of color master batch for polyamide dope coloring mainly includes polymerization stage coloring method and post-polymerization coloring method. The polymerization stage coloring method generally involves mixing polyamide monomers, colorants, dispersants and additives, and then polymerizing them in a high-temperature and high-pressure reactor. After that, the polyamide dope coloring color master batch is prepared by extrusion, water cooling, drying and slicing. The post-polymerization coloring method generally involves mixing polyamide resin, colorants, dispersants and additives, and then melt blending them through a twin-screw extruder. After that, the polyamide dope coloring color master batch is prepared by extrusion, water cooling, drying and slicing.

[0005] In order to fully color the polyamide fiber, a large amount of pigment must be added. The amide bond or end group of the pigment interacts with the polyamide, and part of the pigment with increased concentration forms a melt with increased viscosity. Therefore, it is inevitable to cause problems such as broken yarn, hole blockage, filter blockage, and poor spinning performance during spinning. Therefore, some performance improvements require certain modification of the polyamide. Japanese Patent No. JP4659821B2 discloses a colored polyamide composition containing a high concentration of pigment, which is used in combination with a specific compound and a coupling agent to prepare a colored polyamide fiber that does not bend or break, has good spinning performance, and has good physical properties. Chinese Patent No. CN103232596A provides an aliphatic polyamide modified copolyester, which introduces flexible aliphatic polyamide segments into the macromolecular chain of the polyester, destroys the regularity of the macromolecular chain, reduces the crystallization performance and glass transition temperature of the copolyester, and introduces sulfonate groups and flexible aliphatic polyamide segments into the macromolecular chain of the polyester at the same time, making the copolyester fiber cationic dyeable at normal pressure. Chinese Patent No. CN112745674A discloses a high-pigment carbon black polyamide color master batch containing colorants, carrier resins, dispersants, coupling agents, antioxidants and other raw materials. First, the pigment is modified with a coupling agent, then added to a banbury mixer and mixed with dispersants, antioxidants, carrier resins and other materials, melt blended with a twin-screw extruder, then extruded and granulated to obtain the high-pigment carbon black polyamide color master batch. However, in this invention, the rotation of the screw can achieve a certain degree of dispersion of the pigment particles, but due to the high surface energy of the pigment particles, the reverse process of agglomeration occurs simultaneously. Due to the high viscosity of the polyamide melt, effective dispersion of the pigment is difficult to achieve, so the dispersion of the pigment in the master batch obtained by screw extrusion is difficult to control, and the dyeing uniformity is poor.

[0006] In addition, a Chinese patent with publication number CN110527287A discloses a kind of polyamide color master batch and preparation method thereof: colorant, coupling agent, dispersant are mixed wet grinding to obtain color paste;Polyamide monomer, ring-opening agent are mixed, then after preliminary polymerization in polymerization kettle, continue to carry out in-situ polymerization by adding color paste, after reaction is completed, it is discharged from polymerization kettle, cooling, drying and granulation to obtain polyamide color master batch;Wherein dispersant is polyamide monomer, although the compatibility with polyamide is improved, but the application fails to well improve the dispersibility of pigment particles in polyamide matrix, thereby reducing the coloring effect of color master batch in polyamide. SUMMARY

[0007] To solve the above technical problems, the purpose of the present application is to provide a kind of modified self-dispersing pigment and preparation method and application thereof.The method of the present application is simple, and the modified self-dispersing pigment prepared has good self-dispersing stability;The color master batch prepared by using the modified self-dispersing pigment has good dispersibility and dyeing uniformity, can improve the coloring luster, and improve the coloring power.

[0008] To achieve the above technical purpose and achieve the above technical effect, the present application is realized by the following technical scheme:

[0009] A kind of preparation method of modified self-dispersing pigment, comprising the following steps:

[0010] (1) preparation of pigment dispersion: 5-20 parts of pigment particles, 1-10 parts of dispersant, 80-95 parts of first solvent are mixed and dispersed to obtain pigment dispersion, by mass fraction;

[0011] (2) preparation of self-dispersing pigment: the pigment dispersion obtained in step (1) is prepared into self-dispersing pigment by spray drying method;

[0012] (3) preparation of modified self-dispersing pigment: 3-8 parts of self-dispersing pigment prepared in step (2), 1-5 parts of silane coupling agent, 80-100 parts of second solvent are mixed, and reacted at a certain temperature, to obtain modified self-dispersing pigment after centrifugation, washing and drying.

[0013] The pigment particles in step (1) are at least one of phthalocyanine blue pigment particles, carbon black pigment particles and titanium dioxide pigment particles.

[0014] The dispersant in step (1) is at least one of styrene maleic anhydride copolymer, polyvinylpyrrolidone and fatty alcohol polyoxyethylene ether.

[0015] The first solvent in step (1) is at least one of deionized water, ethanol and N,N-dimethylformamide.

[0016] The mixing and dispersing process in step (1) is a commonly used process for preparing a dispersion; for example, the mixing can be performed by magnetic stirring for 30-60 min; and the dispersing can be performed by ultrasonic dispersing at a power of 400-1200 W for 4-10 h.

[0017] The spray drying process in step (2) is well known in the art; for example, the spray drying process is performed at an air inlet temperature of 160-180℃, a feeding rate of 10 mL / min, an air compressor pressure of 0.2 MPa, and an air flow of 2.95 m 3 / min.

[0018] The silane coupling agent in step (3) is at least one of 3-aminopropyltriethoxysilane, gamma-glycidoxypropyltrimethoxysilane, and gamma-methacryloyloxypropyltrimethoxysilane.

[0019] The second solvent in step (3) is a mixture of ethanol and water, and the mass ratio of ethanol to water is (7-9):(1-3).

[0020] In addition, a certain amount of ammonia water can be added during the reaction in step (3) to control the pH value to be 9-10.

[0021] The specific process of step (3) is as follows: after mixing the self-dispersing pigment, the silane coupling agent, and the solvent, the temperature is increased to 40℃, and the reaction is maintained for 24 h under the condition of continuous stirring at 300 r / min; after the reaction is completed, centrifugal separation is performed at a speed of 5000 r / min for 30 min, the residue is repeatedly washed with ethanol for three times to remove the unreacted silane coupling agent, and the modified self-dispersing pigment is obtained after drying at a temperature of 80℃ and grinding.

[0022] The application further provides a modified self-dispersing pigment prepared by the above method.

[0023] The application further provides an application of the modified self-dispersing pigment in a polyamide in-situ polymerization color master batch, specifically: 50-90 parts by mass of a carrier are added to a reaction kettle, then 10-20 parts by mass of the modified self-dispersing pigment are added, the polymerization conditions are adjusted after stirring and dispersing, a polymerization reaction is performed, the reaction is discharged from the reaction kettle after completion, and a polyamide color master batch is obtained after cooling, drying, and granulation.

[0024] Further, in the application, the carrier is at least one of caprolactam, nylon 66 salt, or polyamide 12T salt.

[0025] Further, the polymerization conditions are: nitrogen purging the reaction kettle, warming to 200-230 DEG C, maintaining the pressure at 2.15-2.35 MPa for 4-5 h; then slowly reducing the pressure to normal pressure, vacuumizing to -0.02--0.01 MPa, while warming to 260 DEG C for 2-2.5 h.

[0026] The beneficial effects of the present application are:

[0027] The present application firstly prepares the pigment dispersion by selecting specific dispersants, designing the dosage of pigment particles, dispersants and first solvents, and using ultrasonic process, and then prepares the self-dispersing pigment by spray drying, so that the particle size and uniformity of the pigment particles can be controlled, the dispersant is loaded on the surface of the pigment particles, the self-dispersing stability of the pigment itself is improved, the pigment can be fully and stably dispersed in the system, and high-efficiency coloring is realized.

[0028] The dispersant used in the present application has the same or similar structure as the polyamide structure, and the amide group is introduced by the silane coupling agent, so that the modified self-dispersing pigment has both the dispersant structure and the amide group on its own structure, thereby greatly improving the self-dispersing stability of the pigment and the compatibility with the polyamide matrix.

[0029] The present application uses a specific carrier to prepare the polyamide color master batch together with the modified self-dispersing pigment, which can improve the good compatibility between the color master batch and the polyamide matrix, so as to achieve the purpose of stable dispersion of the pigment in the subsequent molding process, improve the coloring luster, and improve the coloring power.

[0030] The present application uses a specific carrier to prepare the polyamide color master batch together with the modified self-dispersing pigment, which can improve the good compatibility between the color master batch and the polyamide matrix, so as to achieve the purpose of stable dispersion of the pigment in the subsequent molding process, improve the coloring luster, and improve the coloring power. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 The scanning electron microscope images of the polyamide color master batch prepared in Example 4 of the present application at different magnifications. DETAILED DESCRIPTION

[0032] The technical solutions in the present application will be clearly and completely described below in conjunction with specific embodiments. Obviously, the described embodiments are only some of the embodiments of the present application, but not all of them. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the protection scope of the present application.

[0033] The present application provides a preparation method of modified self-dispersible pigment, comprising the following steps:

[0034] (1) Preparation of pigment dispersion: 5-20 parts of pigment particles, 1-10 parts of dispersant, 80-95 parts of first solvent are mixed and dispersed to obtain a pigment dispersion;

[0035] (2) Preparation of self-dispersible pigment: the pigment dispersion obtained in step (1) is prepared into self-dispersible pigment by spray drying method;

[0036] (3) Preparation of modified self-dispersible pigment: 3-8 parts of self-dispersible pigment prepared in step (2), 1-5 parts of silane coupling agent, 80-100 parts of second solvent are mixed and reacted at a certain temperature, and then centrifuged, washed and dried to obtain modified self-dispersible pigment.

[0037] The pigment particles in step (1) are at least one of phthalocyanine blue pigment particles, carbon black pigment particles, and titanium dioxide pigment particles. The dispersant in step (1) is at least one of styrene maleic anhydride copolymer, polyvinylpyrrolidone, and fatty alcohol polyoxyethylene ether. The first solvent in step (1) is at least one of deionized water, ethanol, and N,N-dimethylformamide.

[0038] The mixing and dispersion process in step (1) is a commonly used process for preparing dispersion; for example, magnetic stirring can be used for mixing, and the stirring time is 30-60 min; ultrasonic dispersion can be used for dispersion, and the power is 400-1200 W, and the time is 4-10 h.

[0039] The spray drying process in step (2) is well known in the art; for example, the inlet air temperature of the spray drying process is 160-180℃, the feeding rate is 10 mL / min, the air compressor pressure is 0.2 MPa, and the air flow is 2.95 m 3 / min.

[0040] The silane coupling agent in step (3) is at least one of 3-aminopropyl triethoxysilane, γ-glycidoxypropyl trimethoxysilane, and γ-methacryloyloxypropyl trimethoxysilane. The second solvent in step (3) is a mixture of ethanol and water, and the mass ratio of ethanol to water is (7-9):(1-3).

[0041] In addition, ammonia water can be added during the reaction of step (3) to control the pH value to 9-10.

[0042] The specific process of step (3) is as follows: after mixing the self-dispersed pigment, the silane coupling agent and the solvent, the temperature is increased to 40 DEG C, and the reaction is maintained for 24 h under the condition of continuous stirring at 300 r / min; after the reaction is completed, centrifugal separation is performed at a rotation speed of 5000 r / min for 30 min, the residue is washed repeatedly with ethanol for three times to remove the unreacted silane coupling agent, and the modified self-dispersed pigment is obtained after drying at a temperature of 80 DEG C and grinding.

[0043] The application further provides a modified self-dispersed pigment prepared by the above preparation method.

[0044] The application further provides an application of the modified self-dispersed pigment in polyamide in-situ polymerization color master batch, specifically: 50-90 parts of a carrier are added into a reaction kettle, then 10-20 parts of the modified self-dispersed pigment are added, the polymerization conditions are adjusted after stirring and dispersing, and a polymerization reaction is performed, the polyamide color master batch is obtained after being discharged from the reaction kettle, and then being cooled, dried and granulated.

[0045] In the application, the carrier is at least one of caprolactam, nylon 66 salt or polyamide 12T salt; and the polymerization conditions are as follows: the reaction kettle is purged with nitrogen, the temperature is increased to 200-230 DEG C, the pressure is maintained at 2.15-2.35 MPa for 4-5 h, then the pressure is slowly reduced to normal pressure, vacuum is extracted to-0.02 to-0.01 MPa, and the temperature is increased to 260 DEG C for 2-2.5 h.

[0046] The application is further described below through specific examples.

[0047] Preparation of modified self-dispersed pigment

[0048] Example 1

[0049] 5 parts of phthalocyanine blue pigment particles, 10 parts of styrene-maleic anhydride copolymer and 85 parts of deionized water are mixed, and the mixture is magnetically stirred for 30 min and dispersed by ultrasonic at a power of 400 W for 8 h to obtain a pigment dispersion. The pigment dispersion is dried in a spray dryer under the conditions of an air inlet temperature of 160 DEG C and a feeding rate of 10 mL / min to prepare a self-dispersed pigment.

[0050] 5 parts of self-dispersed pigment were dispersed in 90 parts of mixed solvent of ethanol and water (mass ratio of 8:2), then 2.5 parts of silane coupling agent 3-aminopropyl triethoxysilane and 2.5 parts of ammonia were also dissolved in the mixed solvent, transferred to a three-necked flask, the temperature was raised to 40℃, and the reaction was kept for 24 h under the condition of continuous stirring at 300 r / min. After the reaction was completed, centrifugal separation was carried out at a speed of 5000 r / min for 30 min, the residue was washed with ethanol repeatedly for three times to remove the unreacted 3-aminopropyl triethoxysilane, and then dried at 80℃ and ground to obtain modified self-dispersed pigment A.

[0051] Example 2

[0052] 5 parts of carbon black pigment particles, 1 part of polyvinylpyrrolidone and 94 parts of ethanol were mixed, and after magnetic stirring for 45 min, pigment dispersion was obtained by ultrasonic dispersion for 4 h under the power of 1200 W. The self-dispersed pigment was prepared by drying in a spray dryer under the conditions of inlet air temperature of 180℃ and feeding rate of 10 mL / min.

[0053] 5 parts of self-dispersed pigment were dispersed in 90 parts of mixed solvent of ethanol and water (mass ratio of 9:1), then 2.5 parts of silane coupling agent γ-glycidoxypropyl trimethoxysilane and 0.5 parts of ammonia were also dissolved in the mixed solvent, transferred to a three-necked flask, the temperature was raised to 40℃, and the reaction was kept for 24 h under the condition of continuous stirring at 300 r / min. After the reaction was completed, centrifugal separation was carried out at a speed of 5000 r / min for 30 min, the residue was washed with ethanol repeatedly for three times to remove the unreacted γ-glycidoxypropyl trimethoxysilane, and then dried at 80℃ and ground to obtain modified self-dispersed pigment B.

[0054] Example 3

[0055] 10 parts of titanium dioxide pigment particles, 10 parts of fatty alcohol polyoxyethylene ether and 80 parts of N,N-dimethylformamide were mixed, and after magnetic stirring for 60 min, pigment dispersion was obtained by ultrasonic dispersion for 10 h under the power of 800 W. The self-dispersed pigment was prepared by drying in a spray dryer under the conditions of inlet air temperature of 180℃ and feeding rate of 10 mL / min.

[0056] 5 parts of self-dispersed pigment were dispersed in 90 parts of mixed solvent of ethanol and water (mass ratio of 7:3), then 2.5 parts of silane coupling agent γ-methacryloxypropyltrimethoxysilane and 0.5 parts of ammonia were also dissolved in the mixed solvent, transferred into a three-necked flask, the temperature was raised to 40℃, and the reaction was kept for 24 h under the condition of continuous stirring at 300 r / min. After the reaction was completed, the residue was centrifuged at a speed of 5000 r / min for 30 min, washed with ethanol for three times to remove the unreacted γ-methacryloxypropyltrimethoxysilane, and dried at 80℃ to obtain modified self-dispersed pigment C after grinding.

[0057] Comparative Example 1 (compared with Example 1, the pigment was not modified with silane coupling agent)

[0058] 5 parts of phthalocyanine blue pigment particles, 10 parts of styrene-maleic anhydride copolymer and 85 parts of deionized water were mixed, and after magnetic stirring for 30 min, a pigment dispersion was prepared by ultrasonic dispersion for 8 h under the condition of 400 W power. The product was dried in a spray dryer under the condition of inlet air temperature of 160℃ and feeding rate of 10 mL / min to obtain self-dispersed pigment a.

[0059] Comparative Example 2 (compared with Example 1, the pigment was not modified with dispersant)

[0060] 5 parts of phthalocyanine blue pigment particles were dispersed in 90 parts of mixed solvent of ethanol and water (mass ratio of 8:2), then 2.5 parts of silane coupling agent 3-aminopropyltriethoxysilane and 2.5 parts of ammonia were also dissolved in the mixed solvent, transferred into a three-necked flask, the temperature was raised to 40℃, and the reaction was kept for 24 h under the condition of continuous stirring at 300 r / min. After the reaction was completed, the residue was centrifuged at a speed of 5000 r / min for 30 min, washed with ethanol for three times to remove the unreacted 3-aminopropyltriethoxysilane, and dried at 80℃ to obtain modified pigment b after grinding.

[0061] Preparation of polyamide color master batch

[0062] Example 4

[0063] 10 parts of modified self-dispersed pigment A and 90 parts of nylon 66 salt were added into a reaction kettle, the reaction kettle was purged with nitrogen for three times, the temperature was raised to 200℃, the pressure was maintained at 2.15 MPa for 4 h, then the pressure was slowly reduced to normal pressure, vacuumized to-0.01 MPa, and the temperature was raised to 260℃ for 2 h, finally the melt was directly extruded, cooled, dried and granulated to obtain polyamide 66 color master batch.

[0064] The prepared polyamide 66 color master batch was placed on an aluminum foil, and the surface morphology of the sample was observed by a SU8100 type field emission scanning electron microscope at an accelerating voltage of 15 kV. The dispersion state of the pigment in the polyamide 66 color master batch was observed by a scanning electron microscope image. As shown in Figure 1

[0065] Example 5

[0066] 10 parts of modified self-dispersed pigment B and 90 parts of nylon 66 salt were added to a reaction kettle, the reaction kettle was purged with nitrogen three times, the temperature was raised to 200°C, the pressure was maintained at 2.15 MPa for 4 h, then the pressure was slowly reduced to normal pressure, vacuum was extracted to-0.01 MPa, while the temperature was raised to 260°C for 2 h, finally the melt was directly extruded, cooled, dried and granulated to obtain a polyamide 66 color master batch.

[0067] Example 6

[0068] 10 parts of modified self-dispersed pigment C and 90 parts of nylon 66 salt were added to a reaction kettle, the reaction kettle was purged with nitrogen three times, the temperature was raised to 200°C, the pressure was maintained at 2.15 MPa for 4 h, then the pressure was slowly reduced to normal pressure, vacuum was extracted to-0.01 MPa, while the temperature was raised to 260°C for 2 h, finally the melt was directly extruded, cooled, dried and granulated to obtain a polyamide 66 color master batch.

[0069] Comparative Example 3 (compared with Example 4, the pigment is not modified)

[0070] 10 parts of phthalocyanine blue pigment particles and 90 parts of nylon 66 salt were added to a reaction kettle, the reaction kettle was purged with nitrogen three times, the temperature was raised to 200°C, the pressure was maintained at 2.15 MPa for 4 h, then the pressure was slowly reduced to normal pressure, vacuum was extracted to-0.01 MPa, while the temperature was raised to 260°C for 2 h, finally the melt was directly extruded, cooled, dried and granulated to obtain a polyamide 66 color master batch.

[0071] Comparative Example 4 (compared with Example 4, the pigment is not modified with a silane coupling agent)

[0072] 10 parts of self-dispersed pigment a and 90 parts of nylon 66 salt were added to a reaction kettle, the reaction kettle was purged with nitrogen three times, the temperature was raised to 200°C, the pressure was maintained at 2.15 MPa for 4 h, then the pressure was slowly reduced to normal pressure, vacuum was extracted to-0.01 MPa, while the temperature was raised to 260°C for 2 h, finally the melt was directly extruded, cooled, dried and granulated to obtain a polyamide 66 color master batch.

[0073] Comparative Example 5 (compared with Example 4, the pigment is not modified with a dispersant) ​

[0074] 10 parts of modified pigment b and 90 parts of nylon 66 salt were added into a reaction kettle, the reaction kettle was purged with nitrogen for three times, the temperature was raised to 200℃, the pressure was maintained at 2.15 MPa for 4 h; then the pressure was slowly reduced to normal pressure, vacuum was extracted to-0.01 MPa, while the temperature was raised to 260℃ for 2 h, finally the melt was directly extruded, after cooling, drying and granulation, polyamide 66 color master batch was obtained.

[0075] Comparative example 6 (compared with example 4, directly mixed with resin granulation, not using in-situ polymerization)

[0076] 90 parts of polyamide resin powder and 10 parts of modified self-dispersible pigment A were stirred and blended, after uniform mixing, heating and melting at 260℃, extruded by a twin-screw extruder, after cooling, hot water extraction, drying and granulation, polyamide color master batch was obtained.

[0077] Polyamide color master batch filter pressing value test

[0078] The polyamide color master batch prepared in examples 4-6 and comparative examples 3-6 was tested by using a filter performance tester to test the filter pressing value DF. The test results are shown in Table 1:

[0079] Table 1

[0080]

[0081] As can be seen from Table 1, the filter pressing value of the color master batch of examples 4-6 prepared by using the modified self-dispersible pigment prepared in examples 1-3 is smaller, and the filter pressing value of the color master batch prepared by using unmodified pigment (comparative example 3) and pigment not modified according to the method of the application (comparative examples 4, 5) is larger, which shows that the modified pigment of the application has good dispersibility and stability, good compatibility with the polyamide matrix, and can be uniformly dispersed.

[0082] Comparative example 6 is directly adding modified self-dispersible pigment in polyester carrier, and the color master batch is obtained by melt extrusion granulation, compared with the method of adding modified self-dispersible pigment in polyamide in-situ polymerization to prepare color master batch in example 4, the filter pressing value of the color master batch prepared in comparative example 6 is larger, which is due to the large melt viscosity and the difficulty of uniform dispersion of the pigment.

[0083] The above is only an embodiment of the application, and does not limit the patent scope of the application, any modification or equivalent transformation made by using the content of the specification and drawings, or direct or indirect application in other related technical fields, are also included in the patent protection scope of the application.

Claims

1. The application of a modified self-dispersible pigment in polyamide in-situ polymerization masterbatch, characterized in that, By mass, 50-90 parts of carrier are added to the reactor, and then 10-20 parts of modified self-dispersible pigment are added. After stirring and dispersing, the polymerization conditions are adjusted and the polymerization reaction is carried out. After the reaction is completed, the mixture is discharged from the reactor and then cooled, dried and granulated to obtain polyamide masterbatch. The preparation method of the modified self-dispersible pigment includes the following steps: (1) Preparation of pigment dispersion: 5-20 parts by mass of pigment particles, 1-10 parts by mass of dispersant and 80-95 parts by mass of first solvent are mixed and dispersed to obtain pigment dispersion; (2) Preparation of self-dispersible pigments: The pigment dispersion obtained in step (1) is prepared by spray drying to obtain self-dispersible pigments; (3) Preparation of modified self-dispersible pigment: 3-8 parts by mass of the self-dispersible pigment prepared in step (2), 1-5 parts by mass of silane coupling agent and 80-100 parts by mass of second solvent are mixed and reacted at a certain temperature. After centrifugation, washing and drying, the modified self-dispersible pigment is obtained. The dispersant in step (1) is at least one of styrene-maleic anhydride copolymer and polyvinylpyrrolidone; The silane coupling agent in step (3) is at least one of 3-aminopropyltriethoxysilane and γ-glycidoxypropyltrimethoxysilane.

2. The application of the modified self-dispersible pigment according to claim 1 in polyamide in-situ polymerization masterbatch, characterized in that, The pigment particles in step (1) are at least one of phthalocyanine blue pigment particles, carbon black pigment particles, and titanium dioxide pigment particles.

3. The application of the modified self-dispersible pigment according to claim 1 in polyamide in-situ polymerization masterbatch, characterized in that, The first solvent in step (1) is at least one of deionized water, ethanol, and N,N-dimethylformamide.

4. The application of the modified self-dispersible pigment according to claim 1 in polyamide in-situ polymerization masterbatch, characterized in that, The second solvent in step (3) is a mixture of ethanol and water, with a mass ratio of ethanol to water of (7~9):(1~3).

5. The application of the modified self-dispersible pigment according to claim 1 in polyamide in-situ polymerization masterbatch, characterized in that, The carrier is at least one of caprolactam, nylon 66 salt, or polyamide 12T salt.

6. The application of the modified self-dispersible pigment according to claim 1 in polyamide in-situ polymerization masterbatch, characterized in that, The polymerization conditions are as follows: the reactor is purged with nitrogen, the temperature is raised to 200~230℃, the pressure is maintained at 2.15~2.35 MPa and the reaction is carried out for 4~5 hours; then the pressure is slowly reduced to atmospheric pressure and then vacuumed to -0.02~-0.01 MPa, while the temperature is raised to 260℃ and the reaction is carried out for 2~2.5 hours.

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