Highly dispersed multifunctional composite color master batch, preparation method for reducing VOC emission and application

Abstract

This invention discloses a highly dispersed multifunctional composite masterbatch, its preparation method for reducing VOC emissions, and its applications, belonging to the field of functional polymer materials. The masterbatch comprises a carrier resin, core-shell structured pigment particles, an amphiphilic block copolymer dispersant, and functional additives. The core-shell structured pigment particles consist of an inorganic pigment core layer and a coupling agent-functionalized shell layer, with the shell layer connected to the core layer via Ti-O-C or Si-O-C covalent bonds. The hydrophilic segments of the amphiphilic block copolymer are physically adsorbed onto the shell surface via hydrogen bonds, while the lipophilic segments extend outward to form a steric hindrance layer. This invention achieves nanoscale uniform dispersion of pigments in the carrier through a dual synergistic mechanism of "chemically bonded shell layer + physical adsorption dispersion," simultaneously endowing the masterbatch with antibacterial and antistatic functions. It has advantages such as simple process, wide applicability, and environmental friendliness with no VOC emissions.

Description

Technical Field

[0001] This invention relates to the field of functional polymer materials technology, specifically to a highly dispersed multifunctional composite masterbatch, a preparation method for preparing the masterbatch that reduces VOC emissions, and the application of the masterbatch. Background Technology

[0002] Color masterbatch is a granular coloring material formed by uniformly loading pigments or dyes onto a carrier resin. It is widely used in the coloring and processing of plastic products. With the continuous advancement of materials science and the increasing demands of applications, the market's performance requirements for color masterbatch have evolved from a single coloring function to high dispersibility, multi-functionality, and environmental friendliness.

[0003] The existing color masterbatch technology mainly suffers from the following technical problems: First, nanoscale pigments exhibit poor dispersion stability in carrier resins. Traditional masterbatches typically use small-molecule dispersants to disperse pigments, but these dispersants have limited compatibility with the pigment surface and carrier resin, making them prone to desorption during processing or storage. This leads to re-agglomeration of pigment particles, affecting color uniformity and the appearance quality of the finished product. Some studies have attempted to improve this defect using polymeric dispersants. For example, Chinese patent application CN120623609A discloses a high-weather-resistant masterbatch with good colorability, its preparation method, and its application. It proposes a masterbatch technology using core-shell structured carbon black particles and hyperbranched dispersants. The core-shell structured carbon black particles utilize a silica shell formed from tetraethyl orthosilicate under ammonia catalysis, further grafted with vinyltrimethoxysilyl groups to provide reactive double bond sites. However, the formation of the silica shell in this technology requires a tetraethyl orthosilicate hydrolysis process, which is relatively complex. Furthermore, its dispersion mechanism mainly relies on the steric hindrance effect of the hyperbranched dispersant, leaving room for further improvement in dispersion performance.

[0004] Secondly, existing color masterbatches do not possess antibacterial and antistatic properties. Conventional color masterbatches only provide coloring. When applied to household appliances, especially plastic products (such as shells and mounting plates) involved in food processing, cooking, baby bottle shakers, or other electrically related food processing or auxiliary processing equipment (such as electric formula makers), they cannot simultaneously provide antibacterial and antistatic effects. To impart antibacterial and antistatic functions to plastic products, multiple functional masterbatches need to be added, which not only increases processing costs and process complexity but also affects the overall performance of the final material due to the interactions between different functional masterbatches.

[0005] Third, solvent-based dispersants pose environmental and health risks. The preparation and use of traditional dispersants often involve volatile organic solvents, which on the one hand lead to VOC emissions and environmental pollution problems, and on the other hand, the residual organic solvents may cause harm to human health.

[0006] Furthermore, Chinese patent application CN121610068A discloses a polyamide cable material, its preparation method, and its application, specifically proposing a technical solution for surface modification of nano-magnesium hydroxide whiskers using a silane coupling agent and an amphiphilic block copolymer in the polyamide cable material. In this solution, the silane coupling agent is grafted onto the whisker surface, the oleophilic end of the amphiphilic block copolymer is assembled onto the whisker surface via the silane coupling agent, and the hydrophilic end is connected to the polyamide. This solution primarily addresses the flame retardancy and temperature resistance issues of the cable material. Its application areas and technical problems differ significantly from those in the field of color masterbatches, and its mechanism of action is chemical assembly rather than physical adsorption, which does not align with the research objective and lacks reference value.

[0007] Therefore, developing a composite masterbatch with high dispersibility, multiple functions, simple process, and environmental friendliness, and its preparation method, is of great practical significance for promoting the technological upgrading of polymer materials in plastic products. Summary of the Invention

[0008] The purpose of this invention is to overcome the shortcomings of the prior art and provide a highly dispersed multifunctional composite masterbatch, a preparation method for preparing the masterbatch that can reduce VOC emissions, and the application of the masterbatch, so as to solve the technical problems of poor pigment dispersibility, lack of antibacterial and antistatic functions, complex process and VOC emissions in the prior art.

[0009] To achieve the above objectives, the present invention provides the following technical solution: a highly dispersed multifunctional composite masterbatch, comprising the following components in parts by weight: Carrier resin: 60-80 parts; Core-shell structured pigment particles: 10-30 parts; Amphiphilic block copolymer dispersant: 2-8 parts; Functional additives: 0.5~5 parts; in, The core-shell structured pigment particles have a core layer and a shell layer covering the surface of the core layer. The core layer is an inorganic pigment, and the shell layer is a functionalized modified layer. The functionalized modified layer is formed by at least one of a silane coupling agent and a titanate coupling agent. The functionalized modified layer is connected to the core layer through a Ti-OC covalent bond or a Si-OC covalent bond. The functional additives include antibacterial agents and antistatic agents. The antibacterial agent is at least one of silver-based inorganic antibacterial agents and zinc-based inorganic antibacterial agents. The antistatic agent is at least one of alkyl sulfonates and ethoxylated fatty amines. The antibacterial mechanism is to destroy the bacterial cell wall and cell membrane structure by slowly releasing silver or zinc ions. The antistatic effect is to form a conductive layer on the material surface to dissipate static charge. The amphiphilic block copolymer dispersant has hydrophilic segments and lipophilic segments. The hydrophilic segments are physically adsorbed onto the surface of the functionalized modified layer through hydrogen bonds, and the lipophilic segments extend outward to form a steric hindrance layer. The average particle size D50 of the pigment dispersion phase in the masterbatch is ≤50nm.

[0010] As a preferred embodiment, the functional modified layer is a compound of titanate coupling agent and silane coupling agent, wherein the mass ratio of titanate coupling agent to silane coupling agent is 1:0.5 to 1:2. The titanate coupling agent provides strong chemical bonding (Ti-OC bond) with the pigment surface, and the silane coupling agent provides polar sites (Si-OH) for forming hydrogen bonds with the hydrophilic segments of the subsequent amphiphilic block copolymer. Together, they form a "dual-anchor" shell structure.

[0011] As a preferred embodiment, the thickness of the functionalized modified layer is 5-50 nm, and the functionalized modified layer provides a dense coating over the core layer. When the shell thickness is less than 5 nm, the coating is easily incomplete, and it is difficult to provide sufficient hydrogen bond adsorption sites; when it is greater than 50 nm, the shell layer is too thick and can easily affect the coloring effect of the pigment. Dense coating (e.g., coating rate ≥95%) ensures the continuity of the shell layer and the uniform distribution of adsorption sites. This thickness range ensures that the coupling agent molecules form a complete coating layer on the pigment surface without affecting the coloring effect of the pigment due to an excessively thick shell layer.

[0012] As a preferred embodiment, the amphiphilic block copolymer is at least one of polyethylene glycol-b-polycaprolactone block copolymer, polyethylene glycol-b-polylactic acid block copolymer, or polyethylene glycol-b-polymethyl methacrylate block copolymer; the molecular weight distribution (PDI) of the amphiphilic block copolymer is ≤1.5. A narrow molecular weight distribution (PDI≤1.5) means that the hydrophilic / lipophilic segment lengths of each dispersant molecule are relatively uniform, resulting in a more regular adsorption arrangement on the pigment surface, better predictability and consistency of steric hindrance effects, and facilitating the achievement of uniform nanoscale dispersion.

[0013] All three block copolymers possess a distinct hydrophilic-hydrophobic amphiphilic structure. The polyethylene glycol segments impart good hydrophilicity to the dispersant, while the polyester or polymethacrylate segments exhibit good hydrophobicity and compatibility with the carrier resin. Compared to fluorinated acrylate block copolymers, the block copolymers selected in this invention exhibit superior biodegradability and better meet environmental protection requirements. Compared to block copolymer dispersants modified with salt-forming groups, the amphiphilic structure of this invention achieves effective adsorption without the introduction of ionic groups.

[0014] As the preferred solution The polyethylene glycol-b-polycaprolactone block copolymer has a molecular weight of 1000~3000 for the polyethylene glycol block and a molecular weight of 3000~6000 for the polycaprolactone block. The polyethylene glycol-b-polylactic acid block copolymer has a molecular weight of 1000~3000 for the polyethylene glycol block and a molecular weight of 3000~6000 for the polylactic acid block. The polyethylene glycol-b-polymethyl methacrylate block copolymer has a molecular weight of 1000-2000 for the polyethylene glycol block and a molecular weight of 2000-4000 for the polymethyl methacrylate block.

[0015] If the hydrophilic segment is too short (<1000), there will be insufficient hydrogen bond adsorption sites; if it is too long (>3000), the hydrophilicity will be too strong, and the compatibility with the hydrophobic carrier resin will decrease. If the lipophilic segment is too short, there will be insufficient steric hindrance; if it is too long, the molecular chains will be excessively entangled, affecting the arrangement density of the dispersant on the pigment surface.

[0016] As a preferred embodiment, the adsorption density of the amphiphilic block copolymer on the surface of the core-shell structured pigment particles is 0.5~2.0 mg / m². If the adsorption density is too low, the steric hindrance is insufficient, and it cannot effectively prevent the pigment particles from agglomerating; if the adsorption density is too high, multilayer adsorption will be formed, which may lead to bridging and flocculation between pigment particles.

[0017] As a preferred embodiment, the inorganic pigment is at least one selected from titanium dioxide, carbon black, iron oxide red, iron oxide yellow, phthalocyanine blue, and phthalocyanine green.

[0018] As a preferred embodiment, the average particle size of the antibacterial agent is ≤100nm. Controlling the particle size of the antibacterial agent to below 100nm is beneficial for its uniform dispersion in the masterbatch system without affecting the dispersion state of the pigment particles.

[0019] As a preferred embodiment, the particle size distribution width (D90-D10) / D50 of the pigment dispersed phase in the masterbatch is ≤1.0. This indicates that the pigment particles are highly uniformly dispersed in the carrier.

[0020] This invention also provides a method for reducing VOC emissions from the above-mentioned highly dispersed multifunctional composite masterbatch, comprising the following steps: S1. Pigment surface modification: Inorganic pigments and coupling agents are surface coated in a modification device. The coupling agent reacts with the hydroxyl groups on the surface of the inorganic pigment to form Ti-OC covalent bonds or Si-OC covalent bonds, forming a functionalized modification layer on the surface of the inorganic pigment, thus obtaining core-shell structured pigment particles. S2. Dispersant Synthesis: Amphiphilic block copolymer dispersants are synthesized using ring-opening polymerization or atom transfer radical polymerization. S3. Dispersant gradient adsorption: The core-shell structured pigment particles obtained in step S1 are mixed with the first part of the amphiphilic block copolymer dispersant, which accounts for 60-80% of the total amount of the amphiphilic block copolymer dispersant, at 40-80°C, with a stirring speed of 200-800 rpm and a mixing time of 30-120 min, so that the hydrophilic segments of the amphiphilic block copolymer are physically adsorbed onto the surface of the functionalized modified layer through hydrogen bonds, and a pre-adsorbed product is obtained. S4. Component premixing: The carrier resin, the pre-adsorbed product obtained in step S3, the remaining 20-40% of the second part of the amphiphilic block copolymer dispersant and functional additives are put into a mixer according to the ratio and premixed to obtain a premix. S5. Melt blending extrusion: The premix obtained in step S4 is fed into a twin-screw extruder for melt blending extrusion. S6. Cooling and granulation: After cooling the material extruded in step S5, it is granulated to obtain highly dispersed multifunctional composite masterbatch.

[0021] The preparation method of this invention adopts a solvent-free melt blending process, which does not use any organic solvents and has no VOC emissions, thus exhibiting good environmental friendliness.

[0022] As a preferred embodiment, the surface coating treatment temperature in step S1 is 60~120℃, and the amount of coupling agent is 1~8% of the dry weight of the inorganic pigment. Under these process conditions, the coupling agent can form a uniform and dense (coating rate ≥95%) functionalized modified layer on the pigment surface, which not only achieves effective coating of pigment particles, but also avoids waste caused by excessive coupling agent.

[0023] As a preferred embodiment, step S1 further includes monitoring the degree of condensation reaction between the coupling agent and the inorganic pigment surface using Fourier transform infrared spectroscopy. The reaction is terminated when the peak area of ​​the characteristic absorption peak of Ti-OC or Si-OC reaches its maximum value and no longer increases. In-situ monitoring effectively ensures that the reaction degree reaches ≥90%, guaranteeing the integrity and consistency of the shell.

[0024] As a preferred embodiment, the premixing temperature in step S4 is room temperature to 60°C, the mixing time is 5 to 30 minutes, and the mixing speed is 200 to 1000 rpm.

[0025] As a preferred embodiment, the extrusion temperature of the twin-screw extruder in step S5 is 150~250℃, and the screw speed is 100~500rpm.

[0026] Furthermore, the present invention also provides the application of the above-mentioned highly dispersed multifunctional composite masterbatch in the coloring of plastic products.

[0027] Compared with existing technologies, the beneficial effects of this technical solution are: (1) This invention uses a coupling agent to directly form a functionalized modified shell on the surface of inorganic pigments, which is firmly connected to the pigment core layer through Ti-OC or Si-OC covalent bonds, avoiding the complex process of preparing a silica intermediate shell in the prior art. This shell reduces the surface energy of the pigment through chemical bonding on the one hand, and provides abundant polar sites (such as Si-OH) for subsequent dispersant adsorption on the other hand, realizing the structural innovation of "chemically bonded shell".

[0028] (2) This invention uses an amphiphilic block copolymer as a dispersant. Through the synergistic mechanism of hydrogen bond physical adsorption formed by its hydrophilic segments and polar groups on the surface of the coupling agent shell, and the extension of its lipophilic segments into the carrier resin to form a steric barrier, an innovative mechanism of "physical adsorption dispersion" is achieved. This dual synergistic effect of "chemically bonded shell + physical adsorption dispersion" allows the dispersed particle size of the pigment in the carrier to be controlled within 50 nm, which is significantly better than the prior art.

[0029] (3) The present invention adopts a gradient adsorption process. First, 60-80% of the dispersant is fully mixed with the core-shell structure pigment particles under low temperature conditions so that it is adsorbed on the shell surface. Then, the remaining 20-40% of the dispersant is added during the melt blending process, which effectively avoids the desorption of the dispersant under high temperature shear conditions and ensures the durability of the dispersion effect.

[0030] (4) By simultaneously introducing antibacterial agents and antistatic agents into the color masterbatch system, the color masterbatch can have antibacterial and antistatic functions while giving the product color, realizing the multi-functional integration of color masterbatch, reducing the amount of subsequent functional masterbatch added, and simplifying the processing technology of plastic products.

[0031] (5) The present invention adopts a solvent-free melt blending preparation process, which eliminates the VOC emission problem from the source and meets the current requirements of green environmental protection and sustainable development.

[0032] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0033] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0034] Figure 1 This is a flowchart of the preparation method of the present invention for preparing highly dispersed multifunctional composite masterbatch that can reduce VOC emissions. Detailed Implementation

[0035] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0036] Example 1 Please see Figure 1 This embodiment provides a highly dispersed multifunctional composite color masterbatch, the components and weight parts of which are as follows: Carrier resin: Polypropylene (PP), 70 parts; Core-shell structured pigment particles: 20 parts of titanium dioxide (TiO2) coated with titanate coupling agent; Amphiphilic block copolymer dispersant: 5 parts of polyethylene glycol-b-polycaprolactone block copolymer (PEG-b-PCL, PEG molecular weight 2000, PCL molecular weight 4000, PDI=1.3); Functional additives: 3 parts silver-based inorganic antibacterial agent (average particle size 60nm), 2 parts alkyl sulfonate antistatic agent, totaling 5 parts.

[0037] Its preparation method is as follows: S1. Pigment Surface Modification: Titanium dioxide and isopropyl tris(dioctyl pyrophosphoryloxy) titanate coupling agent are added to a high-speed mixer at 4% of the pigment's dry weight. The mixture is then mixed at 90℃ and 600 rpm to allow the coupling agent to undergo a condensation reaction with the hydroxyl groups on the titanium dioxide surface, forming Ti-OC covalent bonds and creating a uniformly coated functionalized modified layer on the titanium dioxide surface. The degree of reaction is monitored using Fourier transform infrared spectroscopy. When the characteristic absorption peak of Ti-OC (approximately 1120 cm⁻¹) is reached... - The reaction was terminated when the peak area of ​​¹) reached its maximum value and no longer increased, resulting in core-shell structured titanium dioxide particles with a shell thickness of about 25 nm and a coverage rate of about 96%.

[0038] S2. Dispersant Synthesis: Using polyethylene glycol monomethyl ether as an initiator (Mn=2000) and stannous octoate as a catalyst, ε-caprolactone was ring-opened polymerized to Mn=4000 at 130℃ under nitrogen protection. The molecular weight distribution PDI=1.3 was controlled by atom transfer radical polymerization to obtain polyethylene glycol-b-polycaprolactone block copolymer.

[0039] S3. Gradient adsorption of dispersant: 20 parts of the core-shell structured titanium dioxide particles obtained in step S1 are mixed with 3 parts (accounting for 60% of the total dispersant) of PEG-b-PCL dispersant at 60°C and 500 rpm for 60 min, so that the PEG hydrophilic segments of the dispersant are physically adsorbed on the surface of the titanate shell through hydrogen bonds, and a pre-adsorbed product is obtained.

[0040] S4. Component premixing: 70 parts of polypropylene resin, the pre-adsorbed product obtained in step S3, the remaining 2 parts (accounting for 40% of the total dispersant) of PEG-b-PCL dispersant, 3 parts of silver-based antibacterial agent and 2 parts of alkyl sulfonate antistatic agent are put into a high-speed mixer and mixed at 800 rpm for 20 minutes at 50°C to obtain the premix.

[0041] S5. Melt Blending Extrusion: The premixed material is fed into a twin-screw extruder, and the extrusion temperature is set to 180~220℃ (divided into five temperature zones from the feed port to the die head, namely 180℃, 190℃, 200℃, 210℃, and 220℃ respectively). The screw speed is 300 rpm, and melt blending extrusion is carried out.

[0042] S6. Cooling and granulation: After the extruded material is cooled in a water tank, it is granulated by a pelletizer to obtain highly dispersed multifunctional composite masterbatch.

[0043] The performance of the masterbatch prepared in this embodiment was tested: (1) Pigment dispersion performance: The dispersion particle size of titanium dioxide in the masterbatch was tested by laser particle size analyzer. The results were D50=45nm, D90=78nm, (D90-D10) / D50=0.73, indicating that the pigment was uniformly dispersed at the nanoscale in the carrier resin.

[0044] (2) Antibacterial performance: Antibacterial test was conducted according to GB / T 31402-2015 standard, and the antibacterial rate against Escherichia coli and Staphylococcus aureus reached more than 99.5%.

[0045] (3) Antistatic properties: The volume resistivity was tested according to GB / T 1410-2006 standard, and the result was 3.2×10⁻⁶. 9 Ω·cm, meeting the requirements for antistatic materials.

[0046] (4) Coloring performance: The color masterbatch prepared in this embodiment was mixed with polypropylene at a ratio of 1:25 and then injection molded to obtain a standard color plate. The color measurement results showed that the color difference value ΔE=0.32 and the coloring power reached 98% of the standard sample.

[0047] (5) Environmental performance: No volatile organic compounds (VOCs) were detected when tested according to GB / T 23986-2009.

[0048] Example 2 This embodiment provides a highly dispersed multifunctional composite color masterbatch, the components and weight parts of which are as follows: Carrier resin: Linear low-density polyethylene (LLDPE), 75 parts; Core-shell structured pigment particles: 15 parts of carbon black coated with silane coupling agent; Amphiphilic block copolymer dispersant: 6 parts of polyethylene glycol-b-polylactic acid block copolymer (PEG-b-PLA, PEG molecular weight 3000, PLA molecular weight 5000, PDI=1.4); Functional additives: 4 parts zinc-based inorganic antibacterial agent (average particle size 80nm), 3 parts ethoxylated fatty amine antistatic agent, totaling 7 parts.

[0049] Its preparation method is basically the same as that in Example 1, except that: In step S1, the coupling agent used is γ-aminopropyltriethoxysilane (KH550), the amount of which is 3% of the dry weight of the pigment, and the treatment temperature is 80℃ to form a Si-OC covalent shell layer. In step S2, the dispersant used is PEG-b-PLA; In step S3, the gradient adsorption temperature of the dispersant is 50℃ and the time is 80 min; The premixing time in step S4 is 25 min; In step S5, the extrusion temperature of the twin-screw extruder is 160~200℃, and the screw speed is 350rpm.

[0050] The performance of the masterbatch prepared in this embodiment was tested, and the results were as follows: pigment dispersion particle size D50=48nm, D90=82nm, (D90-D10) / D50=0.71; antibacterial rate against Escherichia coli and Staphylococcus aureus both ≥99.0%; volume resistivity 4.1×10⁻⁶. 9 Ω·cm; color difference ΔE=0.35; tinting strength is 97% of the standard sample; no VOCs were detected.

[0051] Example 3 This embodiment provides a highly dispersed multifunctional composite color masterbatch, the components and weight parts of which are as follows: Carrier resin: ABS resin, 65 parts; Core-shell structured pigment particles: Phthalocyanine blue coated with a complex coupling agent of titanate coupling agent and silane coupling agent, 25 parts; Amphiphilic block copolymer dispersant: polyethylene glycol-b-polymethyl methacrylate block copolymer (PEG-b-PMMA, PEG molecular weight 1500, PMMA molecular weight 3000, PDI=1.2), 4 parts; Functional additives: 2 parts silver-based inorganic antibacterial agent (average particle size 50nm), 2 parts alkyl sulfonate antistatic agent, totaling 4 parts.

[0052] Its preparation method is basically the same as that in Example 1, except that: In step S1, the coupling agent is a complex coupling agent of isopropyl trititanate and γ-methacryloyloxypropyltrimethoxysilane (KH570) in a 1:1 mass ratio, with a total amount of 5% of the dry weight of the pigment, and the treatment temperature is 100℃. In step S2, the dispersant used is PEG-b-PMMA; In step S3, the gradient adsorption temperature of the dispersant is 70℃ and the time is 50 min; In step S4, the premixing temperature is room temperature and the mixing time is 15 min. In step S5, the extrusion temperature of the twin-screw extruder is 190~240℃, and the screw speed is 400rpm.

[0053] The performance of the masterbatch prepared in this embodiment was tested, and the results were as follows: pigment dispersion particle size D50=42nm, D90=73nm, (D90-D10) / D50=0.74; antibacterial rate against Escherichia coli 99.3%, antibacterial rate against Staphylococcus aureus 99.1%; volume resistivity 3.8×10⁻⁶. 9 Ω·cm; color difference ΔE=0.30; tinting strength is 98.5% of the standard sample; no VOCs were detected.

[0054] Comparative Example 1 This comparative example provides a color masterbatch with the same composition as Example 1, except that the pigment is not coated with a coupling agent (i.e., the shell layer in the core-shell structure is omitted), and ordinary titanium dioxide without surface modification is used. Other conditions are the same as in Example 1.

[0055] The performance test results are as follows: the pigment dispersion particle size D50=220nm, D90=520nm, with a wide distribution and obvious agglomeration; the antibacterial rate is about 52%; the volume resistivity is 7.8×10¹¹Ω·cm, which does not meet the requirements for antistatic materials; the color difference value ΔE=1.75; and the tinting strength is 74% of the standard sample.

[0056] Comparative Example 2 This comparative example provides a color masterbatch whose composition is basically the same as that of Example 1. The difference is that core-shell structured pigment particles are used but no amphiphilic block copolymer dispersant is added (i.e., the physical adsorption dispersion layer is omitted). The dispersant synthesis and addition steps are omitted in the preparation method. Other conditions are the same as those in Example 1.

[0057] The performance test results are as follows: pigment dispersion particle size D50=135nm, D90=250nm; antibacterial rate approximately 56%; volume resistivity 6.5×10¹ 0 Ω·cm; color difference value ΔE=0.98; tinting strength is 84% ​​of the standard sample.

[0058] Comparative Example 3 This comparative example provides a color masterbatch whose composition is basically the same as that of Example 1. The difference is that the amphiphilic block copolymer dispersant is added all at once (i.e., the gradient adsorption process is omitted). All 5 parts of dispersant are added at once during the premixing stage, and other conditions are the same as those in Example 1.

[0059] Performance test results are as follows: pigment dispersion particle size D50=78nm, D90=145nm; antibacterial rate approximately 92%; volume resistivity 5.8×10⁻⁶. 9 Ω·cm; color difference ΔE=0.68; tinting strength is 91% of the standard sample. The results show that the dispersion effect and tinting performance of the dispersant added at one time are lower than those of the gradient adsorption process.

[0060] Comparative Analysis of Examples and Comparative Examples The test results of Examples 1-3 and Comparative Examples 1-3 are summarized in the following table: The above results indicate that the masterbatches prepared in Examples 1-3 of this invention exhibit excellent performance in pigment dispersibility (D50≤50nm, particle size distribution width≤0.74), antibacterial rate (≥99%), and antistatic properties (volume resistivity≤4.1×10⁻⁶). 9 In terms of Ω·cm, coloring performance (ΔE≤0.35, coloring power≥97%), it is significantly superior to each of the comparative examples.

[0061] In particular, compared with Comparative Example 2, which only used a coupling agent shell but did not add an amphiphilic block copolymer dispersant, the dispersed particle size of Example 1 was reduced by about 66.7% and the coloring power was increased by 14 percentage points, which fully demonstrates the indispensability of the physical adsorption dispersion layer in the dual synergistic mechanism of "chemically bonded shell + physical adsorption dispersion".

[0062] Compared with Comparative Example 1, which omits the coupling agent shell and uses only the amphiphilic block copolymer dispersant, the dispersed particle size of Example 1 was reduced by approximately 79.5%, and the coloring power was increased by 24 percentage points, demonstrating the key role of the chemically bonded shell as an "anchor point" for the effective adsorption of the amphiphilic block copolymer dispersant.

[0063] Compared with Comparative Example 3, which uses a one-time addition of dispersant, the dispersed particle size of Example 1 was reduced by approximately 42.3%, and the coloring power was increased by 7 percentage points, demonstrating the effectiveness of the gradient adsorption process in ensuring sufficient adsorption of the dispersant and avoiding high-temperature desorption.

[0064] Comparative Example 4 This comparative example provides a color masterbatch with essentially the same composition as Example 1, except that the amount of coupling agent is increased to 12% of the dry weight of the pigment, resulting in a shell thickness of approximately 80 nm. The preparation method and process parameters are the same as in Example 1.

[0065] The performance test results were as follows: the pigment dispersion particle size D50 = 52 nm, which was slightly larger than that of Example 1; the color difference value ΔE = 0.58, and the tinting strength was 93% of the standard sample; the elongation at break of the masterbatch decreased from 380% in Example 1 to 210%, indicating that the excessively thick coupling agent shell layer led to an increase in the rigidity of the pigment particles, which had an adverse effect on the mechanical properties of the masterbatch. Therefore, it is evident that the amount of coupling agent and the shell thickness are not necessarily better the larger they are. The coupling agent amount of 1~8% (corresponding to a shell thickness of 5~50 nm) specified in this invention is a reasonable range obtained through experimental optimization.

[0066] In this application embodiment, the highly dispersed multifunctional composite masterbatch obtained in any of the embodiments 1-3 can be mixed with the plastic raw materials of plastic products, and then the desired plastic products can be obtained by injection molding.

[0067] For example, the highly dispersed multifunctional composite masterbatch obtained in Example 1 is mixed with polypropylene resin at a weight ratio of 1:25, and then injection molded to produce household appliance casings. This is particularly useful in the coloring of plastic products for electrically connected food processing equipment or food auxiliary processing equipment. Examples include the casings and mounting plates of electric baby bottle shakers and electric formula makers.

[0068] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A highly dispersed, multifunctional composite masterbatch, characterized in that, The components include the following parts by weight: Carrier resin: 60-80 parts; Core-shell structured pigment particles: 10-30 parts; Amphiphilic block copolymer dispersant: 2-8 parts; Functional additives: 0.5~5 parts; in, The core-shell structured pigment particles have a core layer and a shell layer covering the surface of the core layer. The core layer is an inorganic pigment, and the shell layer is a functionalized modified layer. The functionalized modified layer is formed by at least one of a silane coupling agent and a titanate coupling agent. The functionalized modified layer is connected to the core layer through a Ti-OC covalent bond or a Si-OC covalent bond. The functional additives include antibacterial agents and antistatic agents. The antibacterial agent is at least one of silver-based inorganic antibacterial agents and zinc-based inorganic antibacterial agents. The antistatic agent is at least one of alkyl sulfonates and ethoxylated fatty amines. The amphiphilic block copolymer dispersant has hydrophilic segments and lipophilic segments. The hydrophilic segments are physically adsorbed onto the surface of the functionalized modified layer through hydrogen bonds, and the lipophilic segments extend outward to form a steric hindrance layer. The average particle size D50 of the pigment dispersion phase in the masterbatch is ≤50nm.

2. The highly dispersed multifunctional composite masterbatch according to claim 1, characterized in that, The functional modified layer is a compound of titanate coupling agent and silane coupling agent, wherein the mass ratio of titanate coupling agent to silane coupling agent is 1:0.5 to 1:

2.

3. The highly dispersed multifunctional composite masterbatch according to claim 1, characterized in that, The thickness of the functionalized modified layer is 5~50nm, and the functionalized modified layer coats the core layer in a dense manner.

4. The highly dispersed multifunctional composite masterbatch according to claim 1, characterized in that, The amphiphilic block copolymer is at least one of polyethylene glycol-b-polycaprolactone block copolymer, polyethylene glycol-b-polylactic acid block copolymer, or polyethylene glycol-b-polymethyl methacrylate block copolymer; the molecular weight distribution (PDI) of the amphiphilic block copolymer is ≤1.

5. The polyethylene glycol-b-polycaprolactone block copolymer has a molecular weight of 1000~3000 for the polyethylene glycol block and a molecular weight of 3000~6000 for the polycaprolactone block. The polyethylene glycol-b-polylactic acid block copolymer has a molecular weight of 1000~3000 for the polyethylene glycol block and a molecular weight of 3000~6000 for the polylactic acid block. The polyethylene glycol-b-polymethyl methacrylate block copolymer has a molecular weight of 1000-2000 for the polyethylene glycol block and a molecular weight of 2000-4000 for the polymethyl methacrylate block. The adsorption density of the amphiphilic block copolymer on the surface of the core-shell structured pigment particles is 0.5~2.0 mg / m².

5. The highly dispersed multifunctional composite masterbatch according to claim 1, characterized in that, The inorganic pigment is at least one of titanium dioxide, carbon black, iron oxide red, iron oxide yellow, phthalocyanine blue, and phthalocyanine green.

6. The highly dispersed multifunctional composite masterbatch according to claim 1, characterized in that, The average particle size of the antibacterial agent is ≤100nm; The particle size distribution width (D90-D10) / D50 of the pigment dispersed phase in the masterbatch is ≤1.

0.

7. A method for preparing a highly dispersed multifunctional composite color masterbatch with reduced VOC emissions according to any one of claims 1-6, characterized in that, Includes the following steps: S1. Pigment surface modification: Inorganic pigments and coupling agents are surface coated in a modification device. The coupling agent reacts with the hydroxyl groups on the surface of the inorganic pigment to form Ti-OC covalent bonds or Si-OC covalent bonds, forming a functionalized modification layer on the surface of the inorganic pigment, thus obtaining core-shell structured pigment particles. S2. Dispersant Synthesis: Amphiphilic block copolymer dispersants are synthesized using ring-opening polymerization or atom transfer radical polymerization. S3. Dispersant gradient adsorption: The core-shell structured pigment particles obtained in step S1 are mixed with the first part of the amphiphilic block copolymer dispersant, which accounts for 60-80% of the total amount of the amphiphilic block copolymer dispersant, at 40-80°C, with a stirring speed of 200-800 rpm and a mixing time of 30-120 min, so that the hydrophilic segments of the amphiphilic block copolymer are physically adsorbed onto the surface of the functionalized modified layer through hydrogen bonds, and a pre-adsorbed product is obtained. S4. Component premixing: The carrier resin, the pre-adsorbed product obtained in step S3, the remaining 20-40% of the second part of the amphiphilic block copolymer dispersant and functional additives are put into a mixer according to the ratio and premixed to obtain a premix. S5. Melt blending extrusion: The premix obtained in step S4 is fed into a twin-screw extruder for melt blending extrusion. S6. Cooling and granulation: After cooling the material extruded in step S5, it is granulated to obtain highly dispersed multifunctional composite masterbatch.

8. The preparation method for reducing VOC emissions according to claim 7, characterized in that, The surface coating treatment in step S1 is carried out at a temperature of 60~120℃, and the amount of coupling agent used is 1~8% of the dry weight of the inorganic pigment; The premixing temperature in step S4 is from room temperature to 60°C, the mixing time is 5 to 30 minutes, and the mixing speed is 200 to 1000 rpm. The extrusion temperature of the twin-screw extruder in step S5 is 150~250℃, and the screw speed is 100~500rpm.

9. The preparation method according to claim 7, characterized in that, Step S1 also includes using Fourier transform infrared spectroscopy to monitor the degree of condensation reaction between the coupling agent and the surface of the inorganic pigment. When the peak area of ​​the characteristic absorption peak of Ti-OC or Si-OC reaches its maximum value and no longer increases, the reaction is terminated.

10. The application of the highly dispersed multifunctional composite masterbatch according to any one of claims 1-6 in the coloring of plastic products.

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