阅读说明：本技术 一种橡塑专用石墨烯微球阻燃母料及制备方法 (Special graphene microsphere flame-retardant master batch for rubber and plastic and preparation method thereof ) 是由 陈庆 昝航 于 2019-10-24 设计创作，主要内容包括：本发明属于橡塑材料技术领域,具体涉及一种橡塑专用石墨烯微球阻燃母料及制备方法。本发明的一种橡塑专用石墨烯微球阻燃母料的制备方法包括如下步骤：将石墨烯粉体均匀分散悬浮在去离子水中,再继续加入无机多孔微球,继续搅拌,再加入硫酸锌、氧化锌、硼砂搅拌分散均匀,再加热至40℃并调节pH值为7～8,保温并搅拌反应1h,喷雾干燥,洗涤、烘干得到无机多孔微球负载石墨烯与硼酸锌的复合材料；将无机多孔微球负载石墨烯与硼酸锌的复合材料与热塑性橡胶、分散剂、润滑剂在密炼机混炼均匀,再移入螺杆挤出机,挤出造粒,得到分散性能优异的阻燃增强母料。本发明可同时改善橡塑保温材料的力学强度及阻燃性能,工艺简单。(The invention belongs to the technical field of rubber and plastic materials, and particularly relates to a graphene microsphere flame-retardant master batch special for rubber and plastic and a preparation method thereof. The preparation method of the special graphene microsphere flame-retardant master batch for rubber and plastic comprises the following steps: uniformly dispersing and suspending graphene powder in deionized water, continuously adding inorganic porous microspheres, continuously stirring, adding zinc sulfate, zinc oxide and borax, uniformly stirring and dispersing, heating to 40 ℃, adjusting the pH value to 7-8, preserving heat, stirring and reacting for 1h, spray drying, washing and drying to obtain the composite material of inorganic porous microsphere loaded graphene and zinc borate; the composite material of inorganic porous microsphere loaded graphene and zinc borate, thermoplastic rubber, a dispersing agent and a lubricating agent are mixed uniformly in an internal mixer, and then the mixture is transferred into a screw extruder to be extruded and granulated, so that the flame-retardant reinforced master batch with excellent dispersing performance is obtained. The invention can improve the mechanical strength and the flame retardant property of the rubber-plastic heat-insulating material at the same time, and the process is simple.)

1. a preparation method of a special graphene microsphere flame-retardant master batch for rubber and plastic is characterized by comprising the following steps:

(1) uniformly dispersing and suspending graphene powder in deionized water under the action of mechanical stirring and a dispersing agent sodium hexametaphosphate to obtain a graphene aqueous dispersion, wherein the mass ratio of the graphene powder to the sodium hexametaphosphate is as follows: 100-110: 10-20, wherein the mechanical stirring is carried out at 140-180 revolutions per minute for 40-85 minutes;

(2) continuously adding inorganic porous microspheres into the graphene aqueous dispersion in the step (1), continuously stirring and dispersing for 5-30 minutes, adding zinc sulfate, zinc oxide and borax after dispersion, and uniformly stirring and dispersing to obtain an inorganic porous microsphere dispersion;

heating the inorganic porous microsphere dispersion liquid to 40 ℃, slowly dropwise adding a 10% sodium carbonate solution at 40 ℃, adjusting the pH value of the inorganic porous microsphere dispersion liquid to 7-8, keeping the temperature at 40 ℃, stirring and reacting for 1h, then performing spray drying on a reaction product, washing and drying to obtain the inorganic porous microsphere loaded graphene and zinc borate composite material;

the zinc borate coats and fixes the graphene in pores of the inorganic porous microspheres; the inorganic porous microspheres are at least one of porous glass microspheres or porous ceramic microspheres;

the mass ratio of the graphene powder to the inorganic porous microspheres to the zinc sulfate to the zinc oxide to the borax is as follows: 1-2: 10-25: 5-12: 1-8: 4-13;

(3) and (3) uniformly mixing the composite material of the inorganic porous microsphere loaded graphene and zinc borate, the thermoplastic rubber, the dispersant and the lubricant in an internal mixer, transferring into a screw extruder, and extruding and granulating to obtain the flame-retardant reinforced master batch with excellent dispersion performance.

2. The preparation method of the special graphene microsphere flame-retardant master batch for rubber and plastic as claimed in claim 1, wherein the mass ratio of the graphene powder and the sodium hexametaphosphate in the step (1) is as follows: and (3) 100-110: 13-16, wherein the mechanical stirring is performed at 160-180 revolutions per minute for 60-70 minutes.

3. The preparation method of the graphene microsphere flame-retardant master batch special for rubber and plastic according to claim 1, wherein the spray drying method in the step (2) is a centrifugal spray drying method or an air-stream spray drying method.

4. The preparation method of the graphene microsphere flame-retardant master batch special for rubber and plastic as claimed in claim 3, wherein the centrifugal circumferential velocity of the centrifugal spray drying method in the step (2) is 130-165 m/s.

5. The preparation method of the graphene microsphere flame-retardant master batch special for rubber and plastic according to claim 1, wherein the inorganic porous microspheres in the step (2) are porous ceramic microspheres.

6. The preparation method of the graphene microsphere flame-retardant master batch special for rubber and plastic according to claim 1, wherein the particle size of the inorganic porous microsphere in the step (2) is less than 20 μm.

7. The preparation method of the graphene microsphere flame-retardant master batch special for rubber and plastic according to claim 1, wherein the inorganic porous microsphere loaded graphene and zinc borate composite material, the thermoplastic rubber, the dispersant and the lubricant in the step (3) are prepared by the following steps: 15-20: 80-120: 3-6: 0.2-0.6;

the thermoplastic rubber is at least one of thermoplastic polyolefin rubber, thermoplastic polyurethane rubber, thermoplastic polystyrene-polybutadiene-polystyrene block copolymer and thermoplastic polystyrene-polyisoprene-polystyrene block copolymer;

the dispersing agent is polyethylene wax;

the lubricant is calcium stearate or stearic acid.

8. A graphene microsphere flame-retardant master batch special for rubber and plastic, which is characterized by being prepared by the method of any one of claims 1-7.

Technical Field

The invention belongs to the technical field of rubber and plastic heat-insulating material materials, and particularly relates to a graphene microsphere flame-retardant master batch special for rubber and plastic and a preparation method thereof.

Background

Rubber and plastic are the general names of rubber and plastic industries, and are all accessory products of petroleum, and plastic is more and more extensive in technical and market demands and application in daily life, and along with continuous improvement and progress of the rubber and plastic industries and improvement of people on understanding and utilization level of rubber and plastic materials, higher requirements are provided for the strength, wear resistance and other properties of the rubber and plastic materials.

Graphene is a monoatomic layer two-dimensional crystal with carbon atoms arranged in an SP2 hybrid manner, is in a hexagonal annular sheet shape, forms a honeycomb crystal structure, is only one carbon atom thick, is the thinnest, the hardest and the most tough material known in the world at present, has very high strength, and becomes the material with the highest known mechanical strength due to strong acting force among the carbon atoms. By utilizing the excellent mechanical property, electrical property, thermal property and the like of the graphene, the composite material also has the excellent properties due to the addition of the graphene.

Graphene has been used as a heat conductive material in the fields of rubber, plastics, coatings, and the like. Although the performance can be greatly improved by adding the graphene into rubber, plastics, coatings and the like, in practical application, the graphene has many problems and restriction factors, and the easy agglomeration of the graphene is a main obstacle for restricting the research and application of the graphene. Although there are some methods for suppressing the occurrence of graphene agglomeration, this requires precise control of reaction conditions, or addition of a small molecule stabilizer, use of a special organic solvent, and the like, which are expensive. In addition, the graphene can play a filling role in the later processing process by adopting a mechanical blending mode, but due to the unique structure of the graphene, graphene lamella layers are difficult to separate, and if the structure of the graphene lamella layers cannot be effectively expanded, the function of using the graphene as a modification auxiliary agent is greatly limited.

The Chinese patent application with the application number of 201710356489.X discloses a graphene microchip reinforced master batch for rubber and plastic and a preparation method thereof. But the preparation process has strict conditions and higher energy consumption.

At present, the reinforcement and flame retardance of rubber and plastic heat-insulating materials are key points for modification, so that a technological means for effectively improving the dispersion of graphene and fully exerting the excellent properties of reinforcement and flame retardance of the graphene is urgently needed to be found.

The patent application with the application number of 201810682690.1 discloses a flame-retardant graphene film and a preparation method thereof, wherein the film is prepared from the following raw materials in parts by weight: 30-40 parts of graphene oxide, 10-13 parts of N-methylpyrrolidine, 30-40 parts of methanol, 10-14 parts of phosphorus trichloride, 1-2 parts of water and zinc borate, 3-5 parts of dammar resin and 1-2 parts of silane coupling agent kh 5501-2 parts. According to the invention, through the modification treatment, the surface activity and the quality of graphene are further improved, and the film disclosed by the invention is high in flame retardance, good in mechanical stability, and high in quality, and also has certain antibacterial performance and the like.

The patent application with the application number of 201810981831.X discloses a graphene flame-retardant shielding cable material and a preparation method thereof, and the graphene flame-retardant shielding cable material comprises, by weight, 70-85 parts of polyvinyl chloride, 10-15 parts of EVA resin, 10-15 parts of conductive carbon black, 1-2 parts of graphene, 3-8 parts of modified magnesium aluminum hydrotalcite, 1-2 parts of zinc borate, 2-3 parts of a lubricant, 0.5-1 part of a stabilizer, 1-2 parts of a cross-linking agent and 0.5-0.8 part of a composite antioxidant, wherein the composite antioxidant comprises, by weight, 30085 parts of an antioxidant, VE3 parts, 2 parts of yttrium oxide and 10 parts of white carbon black. The shielding material has excellent mechanical, electrical, flame retardant and thermal properties, particularly good oxidation resistance and flame retardant properties, and effectively prolongs the service life of the product.

The patent application with the application number of 201810426164.9 discloses a graphene modified rubber composite modified material special for tires, which is prepared from the following raw materials in parts by weight: 35-45 parts of chlorinated natural rubber, 15-25 parts of styrene-butadiene rubber, 10-15 parts of glass fiber, 3-5 parts of nano silicon dioxide, 2-3 parts of chitosan, 1-3 parts of graphite powder, 4-6 parts of calcium silicate, 2-5 parts of paraffin, 1-2 parts of zinc borate and 1-2 parts of zinc oxide. The preparation method comprises the steps of mixing chlorinated natural rubber, styrene butadiene rubber and glass fiber primarily, mixing the mixture with graphene oxide and paraffin for modification, adding related filling materials such as nano silicon dioxide, calcium silicate, zinc borate and zinc oxide and flame retardant materials, and finally mixing, extruding and granulating. The processing process and raw material collocation of the material solve the problems of dispersibility and mixing uniformity among materials, and the obtained composite material has the advantages of good heat dissipation, good static electricity conducting performance, good flame retardant performance, high strength, good wear resistance and the like, and is widely applied to bead, sidewall, crown and the like of tires.

The patent application with the application number of 201711420866.8 discloses an environment-friendly flame-retardant rubber material, which comprises the following raw materials in parts by weight: 50-65 parts of rubber, 20-30 parts of ethylene propylene diene monomer, 5-9 parts of vulcanizing agent, 20-30 parts of vinyl polybutadiene rubber, 8-12 parts of aluminum silicate fiber, 3-5 parts of trioctyl phosphate, 1-3 parts of zinc borate, 1-3 parts of ammonium polyphosphate, 0.5-1 part of nano graphene, 0.1-0.5 part of chitosan, 0.1-0.5 part of nano silver antibacterial agent, 0.1-0.5 part of nano iron dioxide powder, 1-3 parts of metal manganese powder, 0.5-1 part of kaolin, 2-4 parts of asbestos fiber, 0-0.2 part of lavender essential oil, 0-0.2 part of cinnamon essential oil, 0-0.2 part of citronella oil, 0.5-1 part of calcined clay, 1-3 parts of paraffin, 0.5-1 part of superfine glass microsphere and 0.1-0.2 part of mildew preventive; 0.1-0.2 part of preservative and 0.2-0.5 part of antifreeze. The rubber material is green and environment-friendly in raw materials, excellent in abrasion performance and flame retardant property, safe to use, capable of greatly prolonging the service life of rubber and suitable for wide application.

The patent application with the application number of 201610119714.3 discloses a graphene oxide modified polypropylene composite material, which comprises the following raw materials: graphene oxide modified polypropylene, ethylene propylene diene monomer, butadiene-acrylonitrile copolymer, silane coupling agent, zinc borate, magnesium hydroxide, pentaerythritol, epoxidized soybean oil, tricresyl phosphate, pentaerythritol stearate, yttrium oxide, nano mica powder, talcum powder, micro silicon powder, bis (3, 4-dimethyl) benzyl sorbitol, 2' -methylenebis (4, 6-di-tert-butylphenyl) sodium phosphate, ethylene-octene copolymer and 2-hydroxy-4-n-octoxybenzophenone. The graphene oxide modified polypropylene composite material provided by the invention is high in strength, excellent in heat resistance and flame retardance, and good in thermal stability.

Disclosure of Invention

Aiming at the defects that graphene is difficult to uniformly disperse in rubber and plastic materials and performance of the graphene is affected in the prior art, the invention aims to provide a preparation method of a graphene microsphere flame-retardant master batch special for rubber and plastic.

In order to achieve the purpose, the preparation method of the graphene microsphere flame-retardant master batch special for rubber and plastic comprises the following steps:

(1) uniformly dispersing and suspending graphene powder in deionized water under the action of mechanical stirring and a dispersing agent sodium hexametaphosphate to obtain a graphene aqueous dispersion, wherein the mass ratio of the graphene powder to the sodium hexametaphosphate is as follows: 100-110: 10-20, wherein the mechanical stirring is carried out at 140-180 revolutions per minute for 40-85 minutes;

(2) continuously adding inorganic porous microspheres into the graphene aqueous dispersion in the step (1), continuously stirring and dispersing for 5-30 minutes, adding zinc sulfate, zinc oxide and borax after dispersion, and uniformly stirring and dispersing to obtain an inorganic porous microsphere dispersion;

heating the inorganic porous microsphere dispersion liquid to 40 ℃, slowly dropwise adding a 10% sodium carbonate solution at 40 ℃, adjusting the pH value of the inorganic porous microsphere dispersion liquid to 7-8, keeping the temperature at 40 ℃, stirring and reacting for 1h, then performing spray drying, washing and drying on a reaction product to obtain the inorganic porous microsphere graphene-loaded zinc borate composite material;

the zinc borate coats and fixes the graphene in pores of the inorganic porous microspheres; the inorganic porous microspheres are at least one of porous glass microspheres or porous ceramic microspheres;

the mass ratio of the graphene powder to the inorganic porous microspheres to the zinc sulfate to the zinc oxide to the borax is as follows: 1-2: 10-25: 5-12: 1-8: 4-13; the graphene powder is self-made graphene powder with the number of layers within 100, which is obtained by mechanical stripping.

(3) And (3) uniformly mixing the composite material of the inorganic porous microsphere loaded graphene and zinc borate, the thermoplastic rubber, the dispersant and the lubricant in an internal mixer, transferring into a screw extruder, and extruding and granulating to obtain the flame-retardant reinforced master batch with excellent dispersion performance.

Further preferably, the mass ratio of the graphene powder and the sodium hexametaphosphate in the step (1) is as follows: 100-110: 13-16, wherein the mechanical stirring is performed at 160-180 revolutions per minute for 60-70 minutes; preferably, the mass ratio of the graphene powder to the sodium hexametaphosphate is as follows: 105-110: 13-14, and the mechanical stirring is performed at 160-170 rpm for 60-65 minutes.

Further preferably, the spray drying method in the step (2) is a centrifugal spray drying method or an air flow spray drying method; preferably, the spray drying method is centrifugal spray drying.

In order to fully disperse the composite material particles of inorganic porous microspheres loaded with graphene and zinc borate, so that the particles are not adhered, and the loaded substances on the particles are uniformly dispersed, thereby obtaining the composite material particles with uniform particles, the liquid of the invention adopts a centrifugal spray drying method, and the centrifugal circumferential velocity is preferably 130-165 m/s, so that the centrifugal circumferential velocity of the centrifugal spray drying method in the step (2) is further preferably 130-165 m/s.

Further preferably, the inorganic porous microspheres in step (2) are porous ceramic microspheres.

Further preferably, the particle size of the inorganic porous microspheres in the step (2) is less than 20 μm.

Further preferably, the mass ratio of the composite material of graphene and zinc borate loaded on the inorganic porous microspheres in the step (3), the thermoplastic rubber, the dispersant and the lubricant is as follows: 15-20: 80-120: 3-6: 0.2-0.6;

the thermoplastic rubber is preferably at least one of thermoplastic polyolefin rubber, thermoplastic polyurethane rubber, thermoplastic polystyrene-polybutadiene-polystyrene block copolymer and thermoplastic polystyrene-polyisoprene-polystyrene block copolymer;

the dispersing agent is polyethylene wax;

the lubricant is preferably calcium stearate or stearic acid.

The dispersant and the lubricant can be the existing rubber dispersant and lubricant. The rubber dispersant and the compound lubricant compounded by various components can be purchased in the market directly.

The second purpose of the invention is to provide a special graphene microsphere flame-retardant master batch for rubber and plastic, which is prepared by the preparation method of the special graphene microsphere flame-retardant master batch for rubber and plastic, wherein the special graphene microsphere flame-retardant master batch for rubber and plastic contains a composite material of inorganic porous microsphere loaded graphene and zinc borate, and graphene is coated and fixed in pores of the inorganic porous microspheres by the zinc borate.

Has the advantages that:

according to the invention, graphene powder is uniformly dispersed and suspended in deionized water under the action of mechanical stirring and a dispersing agent sodium hexametaphosphate to obtain a graphene aqueous dispersion; continuously adding inorganic porous microspheres into the dispersion liquid, stirring and dispersing, then adding zinc sulfate, zinc oxide and borax for dispersion, and fixedly loading graphene loaded by the inorganic porous microspheres into the microspheres through in-situ deposition of zinc borate with a flame retardant function; the composite material of graphene and zinc borate is loaded by inorganic porous microspheres, wherein the graphene is coated and fixed in pores of the inorganic porous microspheres by the zinc borate, the composite material of graphene and zinc borate loaded by the inorganic porous microspheres, thermoplastic rubber, a dispersing agent and a lubricating agent are mixed uniformly in an internal mixer, and then the mixture is moved into a screw extruder to be extruded and granulated, so that the flame-retardant reinforced master batch with excellent dispersion performance is obtained. The high-fluidity carrier is not easy to agglomerate, so that the uniform dispersion of graphene is promoted, and the zinc borate and the graphene on the covering layer have a synergistic effect and can also play an excellent flame-retardant function, so that the mechanical strength and the flame-retardant property of the rubber and plastic material can be improved, and the application range of the rubber and plastic material is widened.

Detailed Description

The present invention will be described in further detail with reference to specific embodiments, but it should not be construed that the scope of the present invention is limited to the following examples. Various substitutions and alterations can be made by those skilled in the art and by conventional means without departing from the spirit of the method of the invention described above.