Blending material based on inorganic powder and preparation method

Abstract

The invention discloses a blending material based on inorganic powder and a preparation method of the blending material. The blending material comprises the following materials in parts by mass: 50-72 parts of inorganic powder; 20 to 50 parts of a high-molecular polymer; 3-8 parts of a surface treating agent; the inorganic powder is selected from one or more of nano-scale or micron-scale calcium carbonate, barium sulfate, talcum powder, wollastonite, silicon dioxide, aluminum oxide, aluminum hydroxide, magnesium hydroxide and boehmite. The invention aims to overcome the defects in the prior art and provides an inorganic powder / polymer-based blending material and a preparation method thereof. According to the method, a transition layer with strong interaction with a polymer matrix is constructed on the surface of the inorganic powder through an innovative liquid phase pre-dispersion-reactive compounding process, so that superfine and uniform dispersion and firm interface bonding of the inorganic powder are realized, and the comprehensive performance of the composite material is remarkably improved.

Description

Technical Field

[0001] This invention relates to the field of polymer composite materials technology, specifically to a blend material based on inorganic powder and its preparation method. Background Technology

[0002] Inorganic powders (such as calcium carbonate, talc, silica, aluminum hydroxide, and magnesium hydroxide) are commonly used to fill polymers, reducing material costs and improving material rigidity, dimensional stability, flame retardancy, or certain functionalities. However, there are significant differences in the physicochemical properties between inorganic powders and organic polymer matrices, leading to poor compatibility between the two.

[0003] Existing inorganic powder-filled polymer materials suffer from the following problems: low filling amount: in traditional processes, the inorganic powder filling amount is usually below 30 wt%, and excessive amounts will lead to a sharp decline in mechanical properties; weak interfacial bonding: the inorganic powder and polymer have poor compatibility, are prone to agglomeration, and affect the material strength; limited functionality: it is difficult to simultaneously achieve lightweight, flame retardancy, and recyclability. Therefore, it is urgent to design a blend material based on inorganic powder and a preparation method to solve the above problems. Summary of the Invention

[0004] The purpose of this invention is to provide a blended material based on inorganic powder and its preparation method. This invention aims to overcome the shortcomings of existing technologies and provide an inorganic powder / polymer-based blended material and its preparation method. This method utilizes an innovative "liquid-phase pre-dispersion-reactive composite" process to construct a transition layer with strong interaction between the inorganic powder surface and the polymer matrix, achieving ultrafine and uniform dispersion of the inorganic powder and a strong interfacial bond, thereby significantly improving the overall performance of the composite material.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] An inorganic powder-based blend material and its preparation method; the inorganic powder-based blend material has the following composition by mass parts:

[0007] Inorganic powder: 50-72 parts;

[0008] Polymer: 20-50 parts;

[0009] Surface treatment agent: 3-8 parts;

[0010] Functional additives: 1-2 parts.

[0011] Preferably, the inorganic powder is selected from one or more of the following: nano- or micro-sized calcium carbonate, barium sulfate, talc, wollastonite, silicon dioxide, aluminum oxide, aluminum hydroxide, magnesium hydroxide, and boehmite.

[0012] Preferably, the surface treatment agent is one or more of coupling agents, dispersants, or compound modifiers, wherein the coupling agent is a silane, the dispersant is a polyethylene wax derivative polymeric dispersant, and the compound modifier is a hydroxyl-terminated polyethylene modified organosilane.

[0013] Preferably, the functional additives include one of the following: foaming agents or lubricants.

[0014] Preferably, the ratio of coupling agent to dispersant is 1:1 to 2:1.

[0015] A method for preparing an inorganic powder-based blend material, comprising using any one of the inorganic powder-based blend materials described in the previous step, including the following steps:

[0016] S1. Preparation of inorganic powder slurry: Inorganic powder is dispersed in a solvent to form a slurry with a solid content of 10%-40%; under ultrasonic and high-speed shearing, a reactive dispersant is added to the slurry, wherein the reactive dispersant is an organosilicon compound or titanate compound containing hydrolyzable groups (such as alkoxy groups) and polymerizable double bonds (such as methacryloyloxy groups, vinyl groups) in its molecular structure; the mixture is stirred and reacted for 0.5-2 hours to obtain a modified inorganic powder slurry with polymerizable functional groups grafted onto its surface;

[0017] S2. Preparation of prepolymer of polymer monomer: Dissolve the monomer or prepolymer corresponding to the polymer matrix and the optional initiator in a solvent to form a homogeneous solution;

[0018] S3. In-situ composite and blending: The modified inorganic powder slurry obtained in step S1 is mixed with the monomer / prepolymer solution obtained in step S2, stirred under mild conditions and subjected to a preliminary polymerization reaction to form a viscous composite slurry; the inorganic powder accounts for 5%-60% of the mass percentage in the final blended material.

[0019] S4. Solvent Removal and Final Molding: The composite slurry obtained in step S3 is desolventized under vacuum using a twin-screw extruder devolatilization device. At the same time, the deep polymerization of monomers or the melt blending, plasticizing and granulation of prepolymers are completed to obtain the inorganic powder / polymer-based blend material.

[0020] Preferably, in steps S3 and S4, the mild conditions are 40-70°C, and the mixture is stirred and slowly polymerized under nitrogen protection until the viscosity increases significantly, for a period of 1-1.5 hours.

[0021] The temperature settings for each section of the twin-screw extruder are 120-200℃.

[0022] Preferably, the reactive dispersant in step S1 is γ-(methacryloyloxy)propyltrimethoxysilane, vinyltriethoxysilane, or a titanate coupling agent with a similar structure.

[0023] Preferably, the polymer matrix in step S2 is a thermoplastic resin, and the corresponding monomers or prepolymers include methyl methacrylate, styrene, caprolactam, etc.; or it is a precursor of a thermosetting resin, such as unsaturated polyester resin or epoxy resin.

[0024] Preferably, in step S3, an interface compatibilizer may be added. The interface compatibilizer is a polymer with a main chain structure similar to that of the polymer matrix and containing groups that can react with functional groups on the surface of inorganic powder, such as maleic anhydride-grafted polyolefin, acrylic acid-grafted copolymer, etc.

[0025] In the above technical solution, the present invention provides a blend material based on inorganic powder and a preparation method thereof, which has the following beneficial effects:

[0026] This invention aims to overcome the shortcomings of existing technologies and provide an inorganic powder / polymer-based blend material and its preparation method. This method utilizes an innovative "liquid-phase pre-dispersion-reactive composite" process to construct a transition layer with strong interaction between the inorganic powder surface and the polymer matrix, achieving ultrafine and uniform dispersion of the inorganic powder and a robust interfacial bond, thereby significantly improving the overall performance of the composite material.

[0027] Inorganic powders are uniformly dispersed in the polymer matrix in the form of primary particle size or slightly agglomerated secondary particles, and the powders and the matrix form a strong interfacial bond through chemical bonds and physical entanglement.

[0028] Excellent dispersibility: Through "liquid phase pre-dispersion", solvation and mechanical force are used to break up hard agglomerates of powder; "reactive dispersant" chemically grafts polymerizable groups on the powder surface, providing reaction sites for subsequent "in-situ compounding", fundamentally preventing secondary agglomeration during processing and achieving uniform dispersion at the submicron and even nanoscale.

[0029] Strong interfacial bonding: The polymerizable groups on reactive dispersants participate in monomer polymerization or undergo grafting reactions with polymer chains, forming a "flexible bridge" connected by chemical bonds between the powder and the matrix, which greatly enhances the interfacial bonding strength and effectively transfers stress.

[0030] Significantly improved overall performance: Compared with simple mechanical blends, the material prepared by this invention has significantly improved mechanical properties such as tensile strength, impact toughness, and flexural modulus at the same filler content, while maintaining good processing fluidity.

[0031] High process versatility: This method is applicable to a variety of inorganic powders and polymer systems (thermoplastic and thermosetting). It allows for precise interface design by adjusting the molecular structure of reactive dispersants and interfacial compatibilizers, making the process flexible and controllable. Attached Figure Description

[0032] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this invention. For those skilled in the art, other drawings can be obtained based on these drawings.

[0033] Figure 1 This is a composition diagram provided for an embodiment of the present invention of a blend material based on inorganic powder and its preparation method.

[0034] Figure 2 This is a flowchart illustrating the preparation process of an inorganic powder-based blend material and its preparation method according to an embodiment of the present invention.

[0035] Figure 3 This is a performance test table provided for an embodiment of the present invention, which describes a blend material based on inorganic powder and its preparation method.

[0036] Figure 4 This table provides an application field table for an embodiment of the present invention, which describes a blend material based on inorganic powder and its preparation method. Detailed Implementation

[0037] To enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

[0038] like Figure 1 As shown, the embodiments of the present invention provide:

[0039] A blend material based on inorganic powders, comprising the following components by mass: inorganic powder: 50-72 parts; polymer: 20-50 parts; surface treatment agent: 3-8 parts; functional additives: 1-2 parts. The inorganic powders are selected from one or more of the following nano- or micron-sized calcium carbonate, barium sulfate, talc, wollastonite, silica, alumina, aluminum hydroxide, magnesium hydroxide, and boehmite. The inorganic powders undergo surface activation treatment (modified with ureapropyltrimethoxysilane) to form a core-shell structure that enhances interfacial strength. A double-layer coating of the powder with surface treatment agent and resin addresses the issues of agglomeration and weak interfacial structures. The compounded functional additives—foaming agent and flame-retardant components—synergistically achieve a balance between lightweight and high flame retardancy.

[0040] The surface treatment agent is one or more of coupling agents, dispersants, or compound modifiers. The coupling agent is a silane, the dispersant is a polyethylene wax derivative polymeric dispersant, and the compound modifier is a hydroxyl-terminated polyethylene modified organosilane. Functional additives include foaming agents or lubricants. The ratio of coupling agent to dispersant is 1:1-2:1, synergistically solving the problems of powder dispersibility and interfacial strength. The coupling agent reacts with the hydroxyl groups on the powder surface to form a chemical bond layer (such as —Si—O—inorganic bonds). The coupling agent enhances the interfacial bonding force between inorganic powder and polymer, forming chemical bond bridging; the dispersant prevents powder agglomeration and improves dispersion uniformity; the compound modifier has both coupling and dispersing functions, improving the oleophilic / hydrophilic dual compatibility of the powder.

[0041] like Figure 2 As shown, a method for preparing an inorganic powder-based blend material includes using any one of the inorganic powder-based blend materials, comprising the following steps:

[0042] S1. Preparation of Inorganic Powder Slurry: Inorganic powder is dispersed in a solvent to form a slurry with a solid content of 10%-40%; under ultrasonic and high-speed shearing, a reactive dispersant is added to the slurry. The reactive dispersant is an organosilicon compound or titanate compound containing hydrolyzable groups (such as alkoxy groups) and polymerizable double bonds (such as methacryloyloxy groups, vinyl groups) in its molecular structure; the mixture is stirred and reacted for 0.5-2 hours to obtain a modified inorganic powder slurry with polymerizable functional groups grafted onto its surface.

[0043] S2. Preparation of prepolymer of polymer monomer: Dissolve the monomer or prepolymer corresponding to the polymer matrix and the optional initiator in a solvent to form a homogeneous solution;

[0044] S3. In-situ composite and blending: The modified inorganic powder slurry obtained in step S1 is mixed with the monomer / prepolymer solution obtained in step S2. The mixture is stirred and subjected to a preliminary polymerization reaction under mild conditions (40-70°C). Under nitrogen protection, the mixture is stirred and slowly polymerized until the viscosity increases significantly, which takes 1-1.5 hours, forming a viscous composite slurry. The inorganic powder accounts for 5%-60% of the mass percentage in the final blend material.

[0045] S4. Solvent Removal and Final Molding: The composite slurry obtained in step S3 is subjected to solvent removal under vacuum using a twin-screw extruder devolatilization device. The temperature of each section of the twin-screw extruder is set at 120-200℃. Simultaneously, deep polymerization of monomers or melt blending, plasticizing, and granulation of prepolymers are completed to obtain inorganic powder / polymer-based blend materials.

[0046] In step S1, the reactive dispersant is γ-(methacryloyloxy)propyltrimethoxysilane, vinyltriethoxysilane, or a titanate coupling agent with a similar structure, preferably γ-(methacryloyloxy)propyltrimethoxysilane. In step S2, the polymer matrix is ​​a thermoplastic resin, and the corresponding monomers or prepolymers include methyl methacrylate, styrene, caprolactam, etc., preferably methyl methacrylate; or a precursor of a thermosetting resin, such as unsaturated polyester resin or epoxy resin. In step S3, an interface compatibilizer may be added. The interface compatibilizer is a polymer with a main chain structure similar to the polymer matrix and containing groups that can react with functional groups on the surface of inorganic powders, such as maleic anhydride-grafted polyolefins or acrylic acid-grafted copolymers.

[0047] Example 1:

[0048] S1. Disperse 50 parts of light calcium carbonate with an average particle size of 1 μm in 30 g of toluene and sonicate for 30 minutes. Add 3 g of γ-(methacryloyloxy)propyltrimethoxysilane (KH-570) dropwise under high-speed shear and react at 60 °C for 1.5 hours to obtain modified calcium carbonate slurry.

[0049] S2. Mix and dissolve 40 parts of methyl methacrylate (MMA) monomer with 5g of benzoyl peroxide (BPO) initiator.

[0050] S3. Mix all of the S1 slurry with the S2 solution, stir and slowly polymerize at 60℃ under nitrogen protection until the viscosity increases significantly (about 1 hour) to form a composite slurry. Then add 8 parts of surface treatment agent and 2 parts of functional additive. The target calcium carbonate filling amount is calculated to be 10 wt%.

[0051] S4. Transfer the composite slurry to a co-rotating twin-screw extruder, set the temperature of each section to 120-200℃, remove toluene and unreacted monomers under high vacuum, melt extrude, water cool, and pelletize to obtain PMMA / calcium carbonate blend particles.

[0052] Example 2

[0053] S1. Disperse 60 parts of light calcium carbonate with an average particle size of 1 μm in 30 g of toluene and sonicate for 30 minutes. Add 3 g of γ-(methacryloyloxy)propyltrimethoxysilane (KH-570) dropwise under high-speed shear and react at 60 °C for 1.5 hours to obtain modified calcium carbonate slurry.

[0054] S2. Mix and dissolve 30 parts of methyl methacrylate (MMA) monomer with 5g of benzoyl peroxide (BPO) initiator.

[0055] S3. Mix all of the S1 slurry with the S2 solution, stir and slowly polymerize at 60℃ under nitrogen protection until the viscosity increases significantly (about 1 hour) to form a composite slurry. Then add 8 parts of surface treatment agent and 2 parts of functional additive. The target calcium carbonate filling amount is calculated to be 40 wt%.

[0056] S4. Transfer the composite slurry to a co-rotating twin-screw extruder, set the temperature of each section to 120-200℃, remove toluene and unreacted monomers under high vacuum, melt extrude, water cool, and pelletize to obtain PMMA / calcium carbonate blend particles.

[0057] Comparative Example 1

[0058] The traditional melt blending method was adopted: 72 parts of calcium carbonate (untreated) and 28 parts of PMMA granules were directly melt blended and extruded into granules at 200°C in a twin-screw extruder.

[0059] like Figure 3 As shown, the granules obtained from the examples and comparative examples were injection molded into standard test strips and their performance was tested. It was found that the PMMA / calcium carbonate blend granules obtained in Example 2 had the best performance.

[0060] like Figure 4 As shown, the PMMA / calcium carbonate blend material particles obtained by this invention have excellent properties and can be well applied in packaging materials, disposable tableware, fireproof boards, structural components, coal mine reinforcement, building fireproofing, release paper, environmentally friendly films and other fields.

[0061] The foregoing has only described certain exemplary embodiments of the present invention by way of illustration. Undoubtedly, those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the foregoing drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. A blend material based on inorganic powder, characterized in that, The material composition according to parts by mass is as follows: Inorganic powder: 50-72 parts; Polymer: 20-50 parts; Surface treatment agent: 3-8 parts; Functional additives: 1-2 parts.

2. The blend material based on inorganic powder according to claim 1, characterized in that, The inorganic powder is selected from one or more of the following: nano- or micro-sized calcium carbonate, barium sulfate, talc, wollastonite, silicon dioxide, aluminum oxide, aluminum hydroxide, magnesium hydroxide, and boehmite.

3. The blend material based on inorganic powder according to claim 1, characterized in that, The surface treatment agent is one or more of coupling agents, dispersants, or compound modifiers. The coupling agent is a silane, the dispersant is a polyethylene wax derivative polymeric dispersant, and the compound modifier is a hydroxyl-terminated polyethylene modified organosilane.

4. The blend material based on inorganic powder according to claim 1, characterized in that, Functional additives include one of the following: foaming agents or lubricants.

5. The inorganic powder-based blend material according to claim 3, characterized in that, The ratio of coupling agent to dispersant is 1:1 to 2:

1.

6. A method for preparing an inorganic powder-based blend material, comprising using an inorganic powder-based blend material according to any one of claims 1-5, characterized in that, Includes the following steps: S1. Preparation of inorganic powder slurry: Inorganic powder is dispersed in a solvent to form a slurry with a solid content of 10%-40%; under ultrasonic and high-speed shearing, a reactive dispersant is added to the slurry, wherein the reactive dispersant is an organosilicon compound or titanate compound containing hydrolyzable groups and polymerizable double bonds in its molecular structure; the mixture is stirred and reacted for 0.5-2 hours to obtain a modified inorganic powder slurry with polymerizable functional groups grafted onto its surface; S2. Preparation of prepolymer of polymer monomer: Dissolve the monomer or prepolymer corresponding to the polymer matrix and the optional initiator in a solvent to form a homogeneous solution; S3. In-situ composite and blending: The modified inorganic powder slurry obtained in step S1 is mixed with the monomer / prepolymer solution obtained in step S2, stirred under mild conditions and subjected to a preliminary polymerization reaction to form a viscous composite slurry; the inorganic powder accounts for 5%-60% of the mass percentage in the final blended material. S4. Solvent Removal and Final Molding: The composite slurry obtained in step S3 is desolventized under vacuum using a twin-screw extruder devolatilization device. At the same time, the deep polymerization of monomers or the melt blending, plasticizing and granulation of prepolymers are completed to obtain the inorganic powder / polymer-based blend material.

7. The method for preparing a blended material based on inorganic powder according to claim 1, characterized in that, In steps S3 and S4, the mild conditions are 40-70℃, and the mixture is stirred and slowly polymerized under nitrogen protection until the viscosity increases significantly, which takes 1-1.5 hours. The temperature settings for each section of the twin-screw extruder are 120-200℃.

8. The method for preparing a blended material based on inorganic powder according to claim 1, characterized in that, The reactive dispersant mentioned in step S1 is γ-(methacryloyloxy)propyltrimethoxysilane, vinyltriethoxysilane, or a titanate coupling agent with a similar structure.

9. The method for preparing a blended material based on inorganic powder according to claim 1, characterized in that, The polymer matrix mentioned in step S2 is a thermoplastic resin, and the corresponding monomers or prepolymers include methyl methacrylate, styrene, caprolactam, etc.; or it is a precursor of a thermosetting resin, such as unsaturated polyester resin or epoxy resin.

10. The method for preparing a blended material based on inorganic powder according to claim 1, characterized in that, In step S3, an interface compatibilizer may be added. The interface compatibilizer is a polymer that has a similar main chain structure to the polymer matrix and contains groups that can react with functional groups on the surface of inorganic powder, such as maleic anhydride-grafted polyolefin, acrylic acid-grafted copolymer, etc.

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