Graphene-added PET-based conductive and electromagnetic shielding master batch and preparation method thereof

Abstract

The invention discloses a graphene-added PET (Polyethylene Terephthalate)-based conductive and electromagnetic shielding master batch and a preparation method thereof, and aims to solve the problem that in the traditional scheme, in the mixing and granulating process of conductive particles such as carbon black and PET powder, the conductive particles are inevitably subjected to electrostatic agglomeration. According to the scheme of the invention, the primary master batch in which the graphene particles are uniformly distributed is prepared by a method of adding the graphene particles into the PET precursor slurry and PET powder prepared at-70 DEG C, and the primary master batch is crushed and then subjected to secondary granulation, so that the graphene particles in the obtained conductive and electromagnetic shielding master batch are uniformly distributed; therefore, the conductive and electromagnetic shielding master batch with uniform conductivity is obtained, and a foundation is laid for subsequent preparation of conductive yarns and conductive fabrics with good performance.

Description

Technical Field

[0001] The invention relates to the technical field of polymer materials, and in particular to a graphene-added PET-based conductive and electromagnetic shielding masterbatch and a preparation method thereof. Background Art

[0002] In modern society, electromagnetic waves are everywhere. In many fields, such as defense, aerospace, electronic communications, and many other situations, people need to take measures to shield electromagnetic signals. Conductive cloth is a common option. Conductive cloth is usually based on fiber cloth (usually polyester fiber cloth), which is electroplated with metal after pre-treatment to give it metallic properties and become conductive fiber cloth. It can be divided into: nickel-plated conductive cloth, gold-plated conductive cloth, carbon-plated conductive cloth, and aluminum foil fiber composite cloth.

[0003] Conductive fabrics are widely used in modern industry. Currently, this material can be seen in people's sportswear, electronics, instrumentation, and petrochemical industries. It is also widely used in the production of professional shielding work clothes. It is especially suitable for the production of protective tools in some work areas with high electromagnetic radiation, such as touch screen gloves, radiation-proof curtains, and other protective tools.

[0004] At the same time, this material itself has many advantages. It not only has the characteristics of shielding electromagnetic signals, but also has the characteristics of waterproofing, anti-static and so on. In the production process, different materials can be used to create conductive cloth with different characteristics according to different uses. At present, materials with different characteristics can be created according to different uses.

[0005] In the prior art, the formula and process selected during electroplating and carbon plating, such as the selection of materials and thickness control, have a very important impact on the final performance of the conductive cloth. Therefore, when it comes to improving the performance of the conductive cloth, the prior art often starts from the electroplating metal, carbon plating materials, and the thickness control of the electroplating layer and the carbon plating layer. However, these methods have their own limitations, resulting in the final performance of the conductive cloth being limited. The most important manifestation of this limitation is the lack of resistance uniformity and the limited lower limit of resistance of the conductive cloth.

[0006] Therefore, based on the shortcomings of the prior art, this application attempts to find a new way to solve the above problems from the preparation of masterbatch. Chinese patent application CN104277435A proposes a "black conductive electromagnetic shielding masterbatch for PET fiber and its preparation method". This patent application mixes carbon black with conductive properties and ferroferric oxide powder with good magnetic properties, and then adds it to the PET matrix to prepare a black conductive magnetic masterbatch with good conductive properties and magnetic properties. However, this method also has its shortcomings: it cannot solve the problem of uneven dispersion caused by the agglomeration of conductive materials, thereby affecting the conductive uniformity of the final product. Summary of the invention

[0007] The purpose of the present invention is to provide a PET-based conductive and electromagnetic shielding masterbatch with added graphene and a preparation method thereof, so as to obtain a masterbatch with uniform distribution of graphene particles, thereby obtaining a conductive and electromagnetic shielding masterbatch with uniform conductive properties.

[0008] The technical solution of the present invention is as follows:

[0009] A graphene-added PET-based conductive and electromagnetic shielding masterbatch, the components of which are mixed in the following proportions by mass percentage: 5-10% graphene and 90-95% PET.

[0010] The above-mentioned graphene-added PET-based conductive and electromagnetic shielding masterbatch is prepared according to the following steps:

[0011] (1) Grind the commercial PET slices into 20-80 mesh powder at -70°C; (In the embodiment, at -70°C, the powder becomes brittle and easy to crush)

[0012] (2) adding graphene particles of 20-80 meshes to a mixed slurry of terephthalic acid and ethylene glycol in a molar ratio of 1:1 at a ratio of 10-20 wt % of the mixed material, and performing prepolymerization, final polymerization, and pelletization to obtain slices;

[0013] (3) mixing the powder obtained in step (1) and the slices obtained in step (2) in a mass ratio of 1:1, and hot-melt extruding and granulating at 230-300° C. to obtain a primary masterbatch;

[0014] (4) The obtained primary masterbatch is ground again at -70°C into a powder of 20-100 mesh, and then hot-melt extruded and granulated again at 230-300°C to obtain a secondary masterbatch, i.e., the PET-based conductive and electromagnetic shielding masterbatch of the present invention.

[0015] In the conventional solution, during the mixing and granulation process of conductive particles such as carbon black and PET powder, the conductive particles will inevitably undergo electrostatic agglomeration. The solution of the present invention prepares a primary masterbatch with uniform distribution of graphene particles by adding graphene particles to PET precursor slurry and PET powder prepared at -70°C, and then performs secondary granulation after crushing. The graphene particles in the obtained conductive and electromagnetic shielding masterbatch are uniformly distributed, thereby obtaining a conductive and electromagnetic shielding masterbatch with uniform conductive properties, laying a foundation for the subsequent preparation of conductive yarn and conductive cloth with good performance. DETAILED DESCRIPTION

[0016] In order to make the purpose, technical solution and advantages of the embodiments of the present invention more clear, the technical solution in the embodiments of the present invention will be clearly and completely described below in combination with the embodiments of the present invention.

[0017] Example 1

[0018] (1) Grind 5 kg of commercial PET chips into 50 mesh powder at -70°C. The brittle temperature of PET is -70°C, at which the PET chips are very easy to crush;

[0019] (2) 500 g of 80-mesh graphene particles are added to a mixed slurry of terephthalic acid and ethylene glycol in a molar ratio of 1:1, the mixed slurry is 4.5 kg, stirred in a slurry mixing tank, pumped into a slurry feeding tank, and the slurry feeding tank enters the esterification reactor through a slurry injection nozzle. The slurry is uniformly mixed and reacted through the circulation principle of a thermosiphon or the action of a stirrer; the esterified polymers together with various additives on the pipeline are injected into the prepolymerization reactor through a gear pump, and when the materials reach the top of the prepolymerization reactor, they flow to the final polymerization reactor. The final polymerization product is filtered through a melt filter and then pulled to a pelletizer to obtain slices;

[0020] (3) mixing the powder obtained in step (1) and the slices obtained in step (2) in a mass ratio of 1:1, and hot-melt extruding and granulating at 250° C. to obtain a primary masterbatch;

[0021] (4) The obtained primary masterbatch is ground again at -70°C into a 50-mesh powder, and then hot-melt extruded and granulated again at 280°C to obtain a secondary masterbatch, i.e., the PET-based conductive and electromagnetic shielding masterbatch of the present invention.

[0022] Example 2

[0023] (1) Grind 5 kg of commercial PET chips into 50 mesh powder at -70°C;

[0024] (2) 1000 g of 80-mesh graphene particles were added to a mixed slurry of terephthalic acid and ethylene glycol in a molar ratio of 1:1, the mixed slurry was 4 kg, and the rest was the same as in Example 1;

[0025] (3) mixing the powder obtained in step (1) and the slices obtained in step (2) in a mass ratio of 1:1, and hot-melt extrusion granulating at 230° C. to obtain a primary masterbatch;

[0026] (4) The obtained primary masterbatch is ground again at -70°C into a 100-mesh powder, and hot-melt extruded and granulated again at 300°C to obtain a secondary masterbatch, i.e., the PET-based conductive and electromagnetic shielding masterbatch of the present invention.

[0027] The specific embodiments of the present invention are preferred embodiments, and various modifications and improvements may be made without departing from the spirit and scope of the present invention. The scope of the present invention is indicated by the scope of the claims of the application, and all changes that fall within the meaning and scope of equivalents are included therein.

Claims

1. A PET-based conductive and electromagnetic shielding masterbatch with added graphene, characterized in that: The components are mixed in the following proportions by mass: 5-10% graphene and 90-95% PET.

2. The PET-based conductive and electromagnetic shielding masterbatch with added graphene according to claim 1, characterized in that: Prepare according to the following steps: (1) Grind the commercial PET slices into 20-80 mesh powder at -70°C; (2) adding graphene particles of 20-80 meshes to a mixed slurry of terephthalic acid and ethylene glycol in a molar ratio of 1:1 at a ratio of 10-20 wt % of the mixed material, and performing prepolymerization, final polymerization, and pelletization to obtain slices; (3) mixing the powder obtained in step (1) and the slices obtained in step (2) in a mass ratio of 1:1, and hot-melt extruding and granulating at 230-300° C. to obtain a primary masterbatch; (4) The obtained primary masterbatch is ground again at -70°C into a powder of 20-100 mesh, and then hot-melt extruded and granulated again at 230-300°C to obtain a secondary masterbatch, i.e., the conductive and electromagnetic shielding masterbatch of the present invention.