1. The carbon black master batch for the polycarbonate engineering plastic is characterized by comprising 35-45 parts of carbon black, 45-55 parts of polycarbonate carrier resin, 10-15 parts of dispersing agent, 0.01-0.05 part of polymer processing aid and 0.1-1 part of antioxidant;

the dispersant comprises a compound represented by the following formula (I):

wherein R1 represents a thermoplastic polyurethane elastomer segment; each of R2 and R3 independently represents a polycarboxylic acid residue; r4 represents a C2 acrylate group.

2. The carbon black master batch for polycarbonate engineering plastics according to claim 1, wherein the preparation method of the dispersing agent comprises the following steps:

s11, carrying out partial esterification reaction on polyol containing at least four hydroxyl groups and mercaptopropionic acid to obtain a first intermediate;

s12, adding an NCO-terminated thermoplastic polyurethane elastomer into the first intermediate, and continuously reacting to obtain a second intermediate;

s13, adding saturated dicarboxylic acid anhydride to perform esterification reaction with the second intermediate to obtain a third intermediate;

s14, adding acrylic ester with a biphenyl structure and the third intermediate to perform an addition reaction to obtain the dispersing agent.

3. The carbon black master batch for polycarbonate engineering plastics according to claim 2, wherein the molar ratio of the polyol containing at least four hydroxyl groups to mercaptopropionic acid is (1-1.05): 1; the molar ratio of the hydroxyl group of the first intermediate to the isocyanate group of the NCO-terminated thermoplastic polyurethane elastomer is (3-3.05): 1; the molar ratio of the hydroxyl of the second intermediate to the dicarboxylic anhydride is 1 (1-1.05); the molar ratio of the sulfydryl of the third intermediate to the unsaturated bond of the acrylate with the biphenyl structure is (1-1.05): 1.

4. The carbon black masterbatch for polycarbonate engineering plastics according to claim 3, wherein the NCO-terminated thermoplastic polyurethane elastomer is a polyether thermoplastic polyurethane elastomer, and the R value of the NCO-terminated thermoplastic polyurethane elastomer is 1.1-1.12.

5. The carbon black master batch for polycarbonate engineering plastics according to claim 4, wherein the polyol having at least four hydroxyl groups is pentaerythritol; the saturated dicarboxylic acid anhydride is more than one of succinic anhydride, phthalic anhydride and hexahydrophthalic anhydride; the acrylate with the biphenyl structure is o-phenyl phenoxyethyl acrylate.

6. The carbon black masterbatch for polycarbonate engineering plastics according to claim 5, wherein the primary particle size of the carbon black is 10 to 22 nm.

7. The carbon black masterbatch for polycarbonate engineering plastic according to claim 6, wherein the polycarbonate carrier resin is a polycarbonate resin; the melt flow rate of the polycarbonate resin is 10-15 g/10 min.

8. The carbon black masterbatch for polycarbonate engineering plastic according to claim 7, wherein the antioxidant is a hindered phenol antioxidant.

9. The preparation method of the carbon black master batch for the polycarbonate engineering plastic, which is described in any one of claims 1 to 8, is characterized by comprising the following steps:

s21, adding carbon black and a dispersing agent into N-methyl pyrrolidone, carrying out ultrasonic dispersion and mixing, and filtering and drying after uniform mixing;

s22, mixing and uniformly stirring the mixture obtained in the step S21 with polycarbonate carrier resin, a polymer processing aid and an antioxidant;

and S23, performing melting and tabletting on the premix obtained in the step S22, and performing high-speed banburying extrusion, water cooling and granulation to obtain carbon black master batches.

Background

The carbon black is amorphous carbon with a surface area of 10-3000 m²(ii)/g, the particle size is 10-100 nm. The carbon black is used as a black coloring agent, has strong tinting strength, excellent performances of filling, strengthening, ageing resistance, antistatic property and the like, and is widely applied to the fields of plastics and rubber. When carbon black is added in the production of plastics, the problems of particle flying, dust and the like can be caused. To understandTo solve this problem, the plastic industry has gradually changed to use carbon black masterbatch rather than directly using carbon black. However, carbon black is one of the most difficult pigments to disperse, and the smaller the primary particle size of carbon black, the larger the specific surface area, the stronger the intermolecular force between carbon black aggregates, and the more difficult the dispersion, and the dispersibility and particle size of carbon black affect the blackness and coloring power of the carbon black master batch. In order to improve the degree of dispersion of carbon black in a carrier resin, it is common to add a dispersant such as polyethylene wax, EBS, etc. during the preparation process, but such a dispersant causes a decrease in the properties of plastics. Therefore, the research on replacing the dispersant by a special dispersant to prepare the high-performance carbon black master batch is always a problem to be solved in the field.

The carbon black master batch for the polycarbonate engineering plastic generally uses polycarbonate as a carrier resin, so that the problem of compatibility between the carbon black master batch and the polycarbonate engineering plastic can be avoided. Polycarbonate, abbreviated as PC, is an amorphous engineering plastic which is widely applied to various fields due to mechanical properties such as high strength, elastic coefficient, high impact strength, wide use temperature range and the like, but the wear resistance, oil resistance and low-temperature impact resistance of the polycarbonate are not ideal, and the flow property of the polycarbonate is poor, thereby bringing certain troubles to injection molding.

Therefore, when preparing the carbon black master batch for the PC engineering plastic, the problem of the dispersibility of the carbon black in the PC engineering plastic and the problem of how to improve the performance of the PC resin are also considered.

Disclosure of Invention

In order to overcome the defects and shortcomings in the prior art, the invention aims to provide the carbon black master batch for the polycarbonate engineering plastic.

The invention also aims to provide a preparation method of the carbon black master batch for the polycarbonate engineering plastic.

The purpose of the invention is realized by the following technical scheme:

a carbon black master batch for polycarbonate engineering plastics comprises 35-45 parts of carbon black, 45-55 parts of polycarbonate carrier resin, 10-15 parts of a dispersing agent, 0.01-0.05 part of a polymer processing aid and 0.1-1 part of an antioxidant;

the dispersant comprises a compound represented by the following formula (I):

wherein R1 represents a thermoplastic polyurethane elastomer segment; each of R2 and R3 independently represents a polycarboxylic acid residue; r4 represents a C2 acrylate group.

According to the invention, by using the dispersing agent simultaneously containing polar groups, biphenyl groups and thermoplastic polyurethane elastomer (TPU) chain segments, the dispersing agent forms hydrogen bonds with hydroxyl groups, carboxyl groups and other groups on carbon black master batches through a plurality of polar groups, a large pi conjugation effect is formed through the biphenyl groups and benzene rings of polycarbonate, and the long chain of TPU (thermoplastic polyurethane) generates steric hindrance among carbon black particles, so that the cohesion among the carbon black particles is destroyed, the carbon black particles are separated, and an excellent dispersing effect is achieved; the dispersant has an integral structure which can effectively reduce the melt viscosity of the polycarbonate carrier resin, improve the processing fluidity and further increase the dispersibility of the carbon black in the polycarbonate carrier resin.

TPU has the characteristics of high strength, high toughness, cold resistance, oil resistance and the like which cannot be compared with other plastic materials, but has poor compatibility with PC. The invention solves the problem of compatibility of TPU and PC by adding TPU to carbon black master batch in a manner of grafting TPU on a dispersant. The introduction of the TPU improves the wear resistance, solvent resistance and low-temperature impact resistance of the carbon black master batch.

Preferably, the preparation method of the dispersant comprises the following steps:

s11, carrying out partial esterification reaction on polyol containing at least four hydroxyl groups and mercaptopropionic acid to obtain a first intermediate;

s12, adding an NCO-terminated thermoplastic polyurethane elastomer into the first intermediate, and continuously reacting to obtain a second intermediate;

s13, adding saturated dicarboxylic acid anhydride and a second intermediate to perform esterification reaction to obtain a third intermediate;

s14, adding acrylic ester with a biphenyl structure and a third intermediate to perform an addition reaction to obtain the dispersing agent.

Preferably, the molar ratio of the polyol containing at least four hydroxyl groups to the mercaptopropionic acid is (1-1.05): 1; the molar ratio of the hydroxyl group of the first intermediate to the isocyanate group of the NCO-terminated thermoplastic polyurethane elastomer is (3-3.05): 1; the molar ratio of the hydroxyl of the second intermediate to the dicarboxylic anhydride is 1 (1-1.05); the molar ratio of the sulfydryl of the third intermediate to the unsaturated bond of the acrylate with the biphenyl structure is (1-1.05): 1.

In consideration of hydrolysis resistance of carbon black master batch of polycarbonate engineering plastics, the NCO-terminated thermoplastic polyurethane elastomer is preferably a polyether thermoplastic polyurethane elastomer, and the R value of the NCO-terminated thermoplastic polyurethane elastomer is preferably 1.1-1.12.

Preferably, the polyol containing at least four hydroxyl groups is pentaerythritol; the saturated dicarboxylic acid anhydride is more than one of succinic anhydride, phthalic anhydride and hexahydrophthalic anhydride; the acrylate with the biphenyl structure is o-phenyl phenoxyethyl acrylate.

Preferably, the carbon black has a primary particle size of 10 to 22 nm. The smaller the primary particle diameter of the carbon black, the higher the degree of blackness, but accordingly, the higher the degree of difficulty in dispersion.

Preferably, the polycarbonate carrier resin is a polycarbonate resin.

The viscous flow characteristics of plastics in the molten state can generally be expressed by the melt index, and the higher the melt index of the plastics is, the better the processing fluidity of the plastics is, but the properties such as breaking strength, hardness and toughness are also reduced. The melt flow rate of the polycarbonate resin is preferably 10 to 15g/10min in view of the final properties of the carbon black master batch.

Preferably, the antioxidant is a hindered phenolic antioxidant; more specifically, it is preferably at least one of pentaerythrityl tetrakis [ β - (3, 5-di-t-butyl-4-hydroxyphenyl) propionate ], (2, 4-di-t-butylphenyl) phosphite triester and bis (2, 4-di-t-butylphenyl) pentaerythritol diphosphite.

The polymer processing aid is a PPA processing aid selected from PPA2511 and/or PPA3511 (the manufacturer is Guangzhou entropy energy Innovation materials GmbH).

A preparation method of the carbon black master batch for the polycarbonate engineering plastic comprises the following steps:

s21, adding carbon black and a dispersing agent into N-methyl pyrrolidone, carrying out ultrasonic dispersion and mixing, and filtering and drying after uniform mixing;

s22, mixing and uniformly stirring the mixture obtained in the step S21 with polycarbonate carrier resin, a polymer processing aid and an antioxidant;

and S23, performing melting and tabletting on the premix obtained in the step S23, and performing high-speed banburying extrusion, water cooling, granulating, blending, extruding and granulating to obtain the carbon black master batch.

The polymer processing aid is a PPA processing aid selected from PPA2511 and/or PPA3511 (the manufacturer is Guangzhou entropy energy Innovation materials GmbH).

Compared with the prior art, the invention has the beneficial effects that:

1. according to the invention, the dispersing agent and the carbon black are mixed and dispersed, so that the dispersing agent is adsorbed on the carbon black through a plurality of polar groups, the agglomeration effect among carbon black particles is greatly weakened, and the dispersibility of the carbon black is improved.

2. The dispersing agent used in the invention has a biphenyl structure, can interact with aromatic rings on PC carrier resin through large pi conjugation, has good compatibility with the carrier resin, further increases the dispersion effect of carbon black, can improve the hydrolysis resistance of carbon black master batches, and provides a certain plasticizing effect.

3. The TPU chain segment is introduced, so that the low-temperature impact resistance, the wear resistance, the oil resistance and other properties of the carbon black master batch are improved.

4. The dispersant used in the present invention has not only a dispersing effect but also an effect of reducing the melt viscosity of the PC resin, and can improve the processing fluidity of the PC resin.

5. The high-concentration carbon black master batch is prepared by adding the special dispersing agent into the high-pigment carbon black, the addition amount of the high-pigment carbon black can reach more than 35 percent, and the carbon black master batch has the characteristics of high dispersion, high blackness and the like and has excellent compatibility with PC engineering plastics.

Detailed Description

The present invention will be further described with reference to the following examples for facilitating understanding of those skilled in the art, and the description of the embodiments is not intended to limit the present invention. Unless otherwise specified, the technical means used in the examples are conventional means well known to those skilled in the art. Reagents, methods and apparatus used in the present invention are conventional in the art unless otherwise indicated.

The polycarbonate resin was S-3000UR produced by Mitsubishi Japan.

Example 1

The preparation method of the dispersing agent related to the embodiment comprises the following steps:

(1) introducing nitrogen into a reaction kettle with a water separator and a thermometer, adding pentaerythritol, mercaptopropionic acid, methanesulfonic acid and cyclohexane, starting stirring, heating to 100 ℃, refluxing and separating water, stopping the reaction after the theoretical water yield is reached, removing the cyclohexane, washing with water, filtering, and removing water to obtain a first intermediate;

(2) after PTMG1000 (polytetrahydrofuran) and BDO (1, 4-butanediol) are vacuumized and dewatered at the temperature of 110 ℃, dibutyltin dilaurate and MDI (diphenylmethane-4, 4' -diisocyanate) are added, the temperature is raised to 100 ℃, and the reaction is carried out for 3 hours, so as to obtain NCO-terminated thermoplastic polyurethane, wherein the R value is 1.1; adding the first intermediate to continue reacting for 2h to obtain a second intermediate;

(3) dissolving the second intermediate, phthalic anhydride, p-toluenesulfonic acid and hypophosphorous acid in dimethylformamide, introducing nitrogen, heating to 120 ℃, preserving heat for 2 hours, gradually heating to 190 ℃, and continuing to react until the acid value is less than 5 mgKOH/g; vacuumizing, removing dimethylformamide, cooling to 85 ℃ after the dimethylformamide is removed, and discharging to obtain a third intermediate;

(4) and dissolving the third intermediate and o-phenylphenoxyethyl acrylate in N-methylpyrrolidone, performing ultrasonic dispersion for 30min, adding 2-hydroxy-2-methyl-1-phenyl-1-acetone, uniformly stirring, performing ultraviolet irradiation, and removing the N-methylpyrrolidone after 2h irradiation to obtain the dispersing agent (A1).

The molar ratio of the pentaerythritol to the mercaptopropionic acid is 1: 1; the molar ratio of the hydroxyl groups of the first intermediate to the isocyanate groups of the thermoplastic polyurethane elastomer with terminal NCO groups is 3: 1; the molar ratio of the hydroxyl group of the second intermediate to the phthalic anhydride is 1: 1; the molar ratio of the sulfydryl of the third intermediate to unsaturated bonds contained in the o-phenylphenoxyethyl acrylate is 1: 1; the adding amount of the methanesulfonic acid is 0.8 percent of the mass of the reaction system in the step (1); the addition amount of dibutyltin dilaurate was 1% by mass of the reaction system in step (2), the addition amount of p-toluenesulfonic acid was 0.5% by mass of the reaction system in step (3), and the addition amount of hypophosphorous acid was 0.5% by mass of the reaction system in step (3); the adding amount of the 2-hydroxy-2-methyl-1-phenyl-1-acetone is 1 percent of the mass of the reaction system in the step (4).

Example 2

The preparation method of the carbon black master batch for the polycarbonate engineering plastic comprises the following steps:

s1, adding 35 parts of carbon black and 10 parts of a dispersing agent (A1) into N-methylpyrrolidone, carrying out ultrasonic dispersion and mixing, and drying after uniform mixing;

s2, drying the polycarbonate (with the melt flow rate of 10g/10min) at 150 ℃ until the humidity is less than 0.02%;

s3, putting the mixture obtained in the step S1, 55 parts of dried polycarbonate carrier resin, 0.01 part of PPA2511 and 1 part of N, N' -bis- (3- (3, 5-di-tert-butyl-4-hydroxyphenyl) propionyl) hexamethylene diamine into a high-speed mixer at a speed of 900r/min for mixing;

and S4, melting and tabletting the pre-mixture obtained in the step S2, and carrying out high-speed banburying extrusion, water cooling and granulation to obtain the carbon black master batch for the polycarbonate engineering plastic.

Example 3

The preparation method of the carbon black master batch for the polycarbonate engineering plastic comprises the following steps:

s1, adding 45 parts of carbon black and 10 parts of a dispersing agent into N-methyl pyrrolidone, carrying out ultrasonic dispersion and mixing, and drying after uniform mixing;

s2, drying the polycarbonate (with the melt flow rate of 10g/10min) at 150 ℃ until the humidity is less than 0.02%;

s3, putting the mixture obtained in the step S1 and 45 parts of dried polycarbonate carrier resin, 0.05 part of PPA3511 and 1 part of 2.4-dimethyl-6-styrene phenol into a high-speed mixer at the speed of 900r/min for mixing;

and S4, melting and tabletting the pre-mixture obtained in the step S2, and carrying out high-speed banburying extrusion, water cooling and granulation to obtain the carbon black master batch for the polycarbonate engineering plastic.

Example 4

The preparation method of the carbon black master batch for the polycarbonate engineering plastic comprises the following steps:

s1, adding 40 parts of carbon black and 15 parts of a dispersing agent (A1) into toluene, carrying out ultrasonic dispersion and mixing, and drying after uniform mixing;

s2, drying the polycarbonate (with the melt flow rate of 10g/10min) at 150 ℃ until the humidity is less than 0.02%;

s3, putting the mixture obtained in the step S1 and 45 parts of dried polycarbonate carrier resin, 0.05 part of PPA3511 and 0.1 part of 2.4-dimethyl-6-styrene phenol into a high-speed mixer at the speed of 900r/min for mixing;

and S4, melting and tabletting the pre-mixture obtained in the step S2, and carrying out high-speed banburying extrusion, water cooling and granulation to obtain the carbon black master batch for the polycarbonate engineering plastic.

Comparative example 1

The difference from example 2 is that: no dispersant (A1)

The properties of the carbon black master batch prepared in inventive examples 2 to 4 are shown in table 1.

TABLE 1

Example 5

2 parts of the carbon black master batch prepared in examples 2 to 4 and comparative example 1 were mixed with 100 parts of a PC resin, and the mixture was molded by an injection molding machine, and was subjected to property tests such as gloss, hardness, blackness and dispersibility, and the test results are shown in Table 2.

TABLE 2

	Example 2	Example 3	Example 4	Comparative example 1	Test standard
						Carbon black dispersibility	1.6 stage	1.8 stage	Stage 1.7	Grade 5	GB/T 18251-2000
Degree of blackness	25.2	23.2	23.8	40	GB/T 7048-2012
						Degree of gloss (°)	95	98	96	50	GB 8807

As can be seen from Table 1, the carbon black master batches for polycarbonate engineering plastics prepared in examples 2 to 4 have high melt flow rate, high low-temperature notch impact strength and high tensile modulus compared with pure PC, which indicates that the carbon black master batches have the characteristics of good processing fluidity, good low-temperature impact resistance, good strong tensile strength and the like.

As can be seen from Table 2, the carbon black master batches obtained in examples 2 to 4 are excellent in dispersibility, high in blackness and high in gloss. Comparative example 1 compared with example 2, comparative example 1, in which no dispersant was added, gave a carbon black masterbatch having poor dispersibility and low blackness.

The above-described embodiments are preferred implementations of the present invention, and the present invention may be implemented in other ways without departing from the spirit of the present invention. Carbon black master batch of polycarbonate engineering plastic.