CN104017335A - Carbon fiber conductive enhanced PET/polyester alloy and preparation method thereof - Google Patents

Abstract

The invention relates to a carbon fiber conductive reinforced PET/polyester alloy and a preparation method thereof, which is prepared by using the following raw materials: 60-70% PET, 5-20% polyester, 2-4% nucleating agent, 0.5- 10% conductive filler, 5-20% carbon fiber, 1-2% coupling agent, 0.5-1% antioxidant and 0.5-1% lubricant. The preparation method is to first put PET, polyester, nucleating agent, conductive filler, coupling agent, antioxidant and lubricant into the high mixer and mix for 3-5 minutes, and then the first section of the twin-screw extruder The cylinder is added, and the carbon fiber used is added from the fourth section of the twin-screw extruder, and then the speed of the twin-screw extruder is controlled at 1050-1200rpm, and the temperature is 240-250°C for extrusion and granulation, that is, it has mechanical properties. High, short molding cycle, good product appearance conductive carbon fiber reinforced PET/polyester alloy.

Description

A kind of carbon fiber conductive reinforced PET/polyester alloy and preparation method thereof

technical field

The invention belongs to the field of polymer materials, in particular to a carbon fiber conductive reinforced PET/polyester alloy and a preparation method thereof.

Background technique

At present, with the continuous development of industry and the continuous progress of society, the pollution is becoming more and more serious. Therefore, it is urgent to find an environment-friendly, low-carbon, and sustainable development model, especially in terms of materials. Metal smelting consumes a lot of energy and pollutes a lot. Using polymer materials to replace metal materials in some fields can effectively reduce energy consumption and reduce pollution. Therefore, plastic products that are relatively light in weight and relatively easy to process have become ideal substitutes. However, polymer materials do not have the properties of metal materials in some aspects, which is not conducive to processing and application. For example, their electrical conductivity is poor, and the electrical conductivity of unmodified ordinary plastics is very low. The conductive plastic has become a new trend. A conductive polymer composite material comprising a polymer material and a conductive filler has been widely used in the fields of semiconductors, electric appliances, automobiles and aircraft. The main purpose of using this kind of conductive composite material is: for example, it can be directly sprayed without conductive primer in processing, the process is simple, energy saving and environmental protection, it can also protect semiconductor components from static electricity, and prevent precision instruments from malfunctioning by blocking electromagnetic waves. operation, to prevent the generation of static electricity due to friction, etc.

Polyethylene terephthalate (hereinafter referred to as PET) has excellent mechanical properties, heat resistance, electrical properties and chemical stability, and is a cheap thermoplastic engineering plastic. However, due to its easy warping and long molding cycle, its application range is largely limited. In recent years, researchers at home and abroad have done a lot of research on PET blending modification, and many alloyed products have been sold in the market, but this type of alloy is still affected by the compatibility between resins, and its mechanical properties are poor, while PET / Polyester alloys do not have such problems, and the cost is low. Therefore, PET/polyester alloys have become a new development hotspot.

However, PET, PTT (polytrimethylene terephthalate), PBT (polybutylene terephthalate), and PEN (polyethylene naphthalate), etc. have similar chemical structures, Although the compatibility between polyesters is very good, their crystallization properties are quite different from each other. In order to improve the difference in crystallinity and optimize the performance of the alloy, it is necessary to use a nucleating agent. The nucleating agents currently on the market can be divided into three categories: inorganic, organic and macromolecular. Among them, the ionomer Surlyn resin developed by DuPont Company of the United States has a better effect.

Carbon fiber not only has the inherent intrinsic characteristics of carbon materials, but also has the soft processability of textile fibers. Its specific gravity is less than 1/4 of that of steel, but its strength is very high. It is a new generation of reinforcing fiber. Compared with traditional glass fiber (GF), the Young's modulus of carbon fiber is more than three times, and it is insoluble in organic solvents, acids, and alkalis, and has excellent corrosion resistance. Carbon fibers are divided into general-purpose and high-performance types according to their mechanical properties. The general-purpose carbon fiber has a strength of 1000 megapascals (MPa) and a modulus of about 100 GPa. High-performance carbon fiber is divided into high-strength type (strength 2000MPa, modulus 250GPa) and high-model (modulus above 300GPa), the strength greater than 4000MPa is also called ultra-high-strength type: the modulus greater than 450GPa is called ultra-high model. In addition, carbon fiber itself has conductive properties, and can penetrate through the resin collective to form a conductive network chain, thereby greatly improving the conductivity of the material.

Chinese patent document CN103224694A discloses a preparation method of a conductive PBT composite material, the formula of which is: 80-100 parts of polyethylene terephthalate, 15-20 parts of conductive masterbatch, 1-5 parts of toughening agent 1-2 parts of light shielding agent, 0.2-0.8 parts of antioxidant. Among them, the conductive masterbatch is composed of 68% graphene, 22% dispersant, and 10% coupling agent. The invention makes conductive masterbatches, which increases the complexity of the process and indirectly increases the cost; more graphene is added to the compound, and the cost of the material is obviously higher. At the same time, the cost of PBT is also higher than that of PET. Obviously high, not conducive to industrialization, low competitiveness.

Chinese patent document CN1420911A discloses a conductive PPO/PA alloy and its preparation method. The composite materials are as follows in terms of weight percentage: 10-50 parts of polyphenylene ether, 35-65 parts of nylon, 0.4-3 parts of carbon fibrils parts, 5-40 parts of talc, compatibilizer up to 10 parts and impact modifier up to 20 parts. The preparation process of the invention is simple, and the prepared product has good mechanical properties, high stability, and good flame retardancy and electrical conductivity.

However, the compatibility of the two-phase system used in the above-mentioned alloy materials is not good, so it is necessary to add a compatibilizer to make them compatible, which will not only increase the cost of the alloy, but also affect the rigidity of the material, resulting in poor tensile and bending properties. decrease. Secondly, the cost of polyphenylene ether is higher than that of PET, and the cost of PET in this conductive alloy is relatively lower than that of other polyesters, and has been processed. Although the above alloy materials are reinforced with carbon fibers, no silane coupling agent is added to improve the dispersion and interfacial force of carbon fibers between resin matrices, so the reinforcement and conductive effects of carbon fibers have not been fully exerted. The mechanical properties are not ideal. In addition, the silane coupling agent can also improve the affinity between the inorganic filler and the resin in the material, thereby improving the performance of the alloy. The present invention is proposed in order to solve these problems.

Contents of the invention

The object of the present invention is to provide a carbon fiber conductive reinforced PET/polyester alloy and a preparation method thereof in order to overcome the above-mentioned defects in the prior art.

The purpose of the present invention can be achieved through the following technical solutions:

A carbon fiber conductive reinforced PET/polyester alloy is prepared from the following components and raw materials in parts by weight:

PET60-70, polyester 5-20, nucleating agent 2-4, conductive filler 0.5-10, carbon fiber 5-20, coupling agent 1-2, antioxidant 0.5-1, lubricant 0.5-1.

The PET is polyethylene terephthalate with a viscosity of 0.8-0.9dl/g.

The polyester is polypropylene terephthalate, polybutylene terephthalate or polyethylene 2,6-naphthalate.

Described nucleating agent is Surlyn resin.

The conductive filler is selected from one or more of natural flake graphite powder, artificial graphite powder, expanded graphite, carbon black or conductive metal powder.

The carbon fibers are T700 grade carbon fibers with a tensile strength of 5200MPa.

The coupling agent is a silane coupling agent.

The antioxidant is selected from one or both of the antioxidant 168 or the antioxidant 1010.

The lubricant is selected from one or both of paraffin wax, polyethylene wax or polypropylene wax.

As a preferred embodiment, the polyester alloy is prepared using the following components and raw materials in parts by weight: PET65.8, polyester 17, nucleating agent 4, conductive filler 5.7, carbon fiber 5, coupling agent 1, antioxidant 1, lubricant 0.5%; Described polyester is polyethylene 2,6-naphthalate; Described nucleating agent is Surlyn resin; Described conductive filler is selected from natural flake graphite powder, artificial graphite powder , expanded graphite, carbon black or conductive metal powder; the grade of the carbon fiber is T700, and the tensile strength is 5200MPa; the coupling agent is a silane coupling agent; the antioxidant is The mixture of antioxidant 168 and antioxidant 1010 in a mass ratio of 3:7; the lubricant is paraffin.

As a preferred embodiment, the polyester alloy is prepared using the following components and raw materials in parts by weight: PET67.4, polyester 12.6, nucleating agent 3, conductive filler 4, carbon fiber 10, coupling agent 1.5, antioxidant 1, lubricant 0.5%; Described polyester is polytrimethylene terephthalate; Described nucleating agent is Surlyn resin; Described conductive filler is selected from natural flake graphite powder, artificial graphite powder, expanded graphite, carbon One or more of black or conductive metal powder; the carbon fiber grade is T700, the tensile strength is 5200MPa; the coupling agent is a silane coupling agent; the antioxidant is antioxidant 168 and Antioxidant 1010 is a mixture composed of a mass ratio of 3:7; the lubricant is polyethylene wax.

As a preferred embodiment, the polyester alloy is prepared using the following components and raw materials in parts by weight: PET67.4, polyester 12.6, nucleating agent 3, conductive filler 4, carbon fiber 10, coupling agent 1.5, antioxidant 1, lubricant 0.5%; Described polyester is polybutylene terephthalate; Described nucleating agent is Surlyn resin; Described conductive filler is selected from natural flake graphite powder, artificial graphite powder, expanded graphite , carbon black, carbon nanotubes or conductive metal powder; the carbon fiber grade is T700, and the tensile strength is 5200MPa; the coupling agent is a silane coupling agent; the antioxidant It is a mixture of antioxidant 168 and antioxidant 1010 in a mass ratio of 3:7; the lubricant is polyethylene wax.

As a preferred embodiment, the polyester alloy is prepared using the following components and raw materials in parts by weight: PET61.2, polyester 15.3, nucleating agent 3, conductive filler 2.5, carbon fiber 15, coupling agent 1.5, antioxidant 0.5, lubricant 1%; Described polyester is polytrimethylene terephthalate; Described nucleating agent is Surlyn resin; Described conductive filler is generally made of natural flake graphite powder, artificial graphite powder, expanded graphite, carbon One or more of black or conductive metal powder; the carbon fiber grade is T700, and the tensile strength is 5200MPa; the coupling agent is a silane coupling agent; the antioxidant is antioxidant 1010; The lubricant is a mixture of paraffin wax and polypropylene wax with a mass ratio of 1:1.

As a preferred embodiment, the polyester alloy is prepared using the following components and raw materials in parts by weight: PET61.2, polyester 15.3, nucleating agent 3, conductive filler 2.5, carbon fiber 15, coupling agent 1.5, antioxidant 0.5, lubricant 1%; Described polyester is polybutylene terephthalate; Described nucleating agent is Surlyn resin; Described conductive filler is selected from natural flake graphite powder, artificial graphite powder, expanded graphite One or more of carbon black or conductive metal powder; the carbon fiber grade is T700, and the tensile strength is 5200MPa; the coupling agent is a silane coupling agent; the antioxidant is an antioxidant 1010; the lubricant is a mixture of paraffin wax and polypropylene wax with a mass ratio of 1:1.

As a preferred embodiment, the polyester alloy is prepared using the following components and raw materials in parts by weight: PET65.6, polyester 7.4, nucleating agent 2, conductive filler 1.5, carbon fiber 20, coupling agent 2, antioxidant 0.5, lubricant 1; Described polyester is polybutylene terephthalate; Described nucleating agent is Surlyn resin; Described conductive filler is selected from natural flake graphite powder, artificial graphite powder, expanded graphite, One or more of carbon black or conductive metal powder; the carbon fiber grade is T700, and the tensile strength is 5200MPa; the coupling agent is a silane coupling agent; the antioxidant is antioxidant 1010 ; The lubricant is a mixture of polyethylene wax and polypropylene wax in a mass ratio of 1:1.

The preparation method of carbon fiber conductive reinforced PET/polyester alloy adopts the following steps:

(1) Put PET, polyester, nucleating agent, conductive filler, coupling agent, antioxidant and lubricant into the high mixer and mix for 3-5 minutes, and then add it from the first section of the twin-screw extruder ;

(2) carbon fiber is added from the fourth section of the cylinder of the twin-screw extruder;

(3) Controlling the rotational speed of the twin-screw extruder to 1050-1200rpm and the temperature to 240-250°C for extrusion and granulation to prepare a conductive carbon fiber reinforced PET/polyester alloy.

Compared with the prior art, the present invention has the following advantages:

(1) Due to the adoption of a suitable nucleating agent in the preparation process, the crystallization properties of the polyester alloy are improved. Because Surlyn8920 can react with PET at high temperature to form a product PET-COONa with ionic end groups, this product forms capped ion clusters and aggregates in PET melt to form heterogeneous microdomains. promotes primary nucleation. At the same time, there is an interface layer mainly composed of PET molecular chain structure units on the surface of heterogeneous micro-domains, which has a good interaction with ion clusters, thus accelerating the formation of primary crystal nuclei. While PET-COONa was generated. There is also the generation of PET-R (R is the flexible group of Surlyn8920). Since R molecular chains are more flexible than PET molecular chains, its introduction can promote the flexible movement of PET molecular chains, which not only reduces the free energy of molecular chains diffusing into the lattice, but also increases the crystallization rate of PET. In addition, due to the presence of ester in the system, the reaction will generate ester-COONa and ester-R. The presence of these two substances will further enhance the above-mentioned effect, making the crystallization rate of the system faster, thereby shortening the conductive carbon fiber reinforced PET/ Molding cycle of polyester alloy. No other nucleating agent has been found to have such an effect.

(2) Due to the use of carbon fiber in the preparation process, not only can the mechanical properties of the material be greatly improved, but also the effect of enhancing electrical conductivity can be achieved. Carbon fiber has good electrical conductivity. The percolation theory believes that the electrical conductivity of conductive composite materials is composed of three conditions alone or in combination: ①The conductive particles contact each other to form a continuous chain structure, forming a conductive channel; ②Each conductive particle is dispersed independently In the matrix, conductive channels are formed through tunneling or electron emission; ③The conductive particles continue to connect, which is the comprehensive result of chain channels and tunneling. According to the percolation theory, the original isolated and dispersed filler particles will form a continuous conductive path after the volume dispersion reaches a certain critical content. At this time, the conductive particles are in two states. One is the physical contact between the particles, and the charge carriers can It flows in a continuous conductor; the second is that there is a thin layer of adhesive between the particles, so that the carriers themselves are activated and move. According to the principle of "percolation theory", the formation of a conductive network is a prerequisite for composite materials to achieve conductive functions. The larger the aspect ratio of carbon fibers, the more conducive to the overlapping of conductive fibers to form conductive channels. In composite materials, carbon fibers contact each other to form a carbon fiber-carbon fiber conductive network; bridges, forming a carbon black-carbon fiber-carbon black conductive network. At the same time, the carbon fiber has high mechanical properties, with a tensile modulus as high as 5200MPa, which can achieve mechanical effects that cannot be achieved by other ordinary conductive carbon fibers, and enhance the mechanical properties of the material.

(3) Due to the silane coupling agent used in the preparation process, the hydrolyzed groups in the silane coupling agent combine with inorganic substances to form siloxane; while the organic functional groups in the silane coupling agent can react with organic substances to combine, By using silane coupling agent, a "molecular bridge" can be set up between the interface of inorganic substances and organic substances, and the two materials with different properties can be connected together to improve the performance of composite materials and increase the bonding strength. After testing, the silane coupling agent KH570 is the best type of coupling agent used in polyester. The surface treatment of carbon black by KH570 improves the affinity between carbon black filler and resin, improves the mechanical properties of composite materials, and also improves the dispersion and interfacial force of carbon fibers between resin matrices, thereby optimizing the mechanical properties and properties of materials. Conductive properties, improve the appearance of the product.

(4) The prepared conductive carbon fiber reinforced PET/polyester alloy has good mechanical properties and electrical conductivity, and can replace expensive special engineering plastics in some occasions, and has broad application prospects.

Detailed ways

The present invention will be further elaborated below by specific examples, but the present invention is not limited.

The PET resin used in each embodiment of the present invention is the PET-CB-608S of Shanghai Yuanfang Industrial Co., Ltd.;

PBT (polybutylene terephthalate) is PBT-TH6100 of Xinjiang Lanshan Tunhe Polyester Co., Ltd.;

PTT (polytrimethylene terephthalate) is 4700-TFE-10 of American RTP Company;

PEN (polyethylene 2,6-naphthalate) is TN-8065S of Teijin Corporation of Japan;

The nucleating agent is the ionomer Surlyn8920 of DuPont, USA;

The carbon black is ZY6500 produced by Yunnan Qujing Zhongyi Fine Chemical Co., Ltd., with a particle size of 44um;

Flake graphite is Qingdao Dongkai Graphite Co., Ltd., with particle sizes of 12um, 44um, and 104um;

The graphite powder is Shenzhen Huananxin Technology Co., Ltd., and the particle size is 104um;

Expanded graphite is Qingdao Fusheng Graphite Co., Ltd., with a particle size of 325 mesh;

Conductive metal powder is Shenzhen Changxinda Shielding Material Co., Ltd., particle size 325, 400, 600, 800 mesh;

The carbon fiber is TG01 of Korea Hyosung Company;

The silane coupling agent is KH-570 of Nanjing Qianpeng Chemical Co., Ltd.;

Antioxidant 168 and Antioxidant 1010 are produced by BASF, Germany;

Paraffin is produced by Shijiazhuang Yima Chemical Co., Ltd.;

Polyethylene wax and polypropylene wax are produced by Shanghai Kemed Industrial Co., Ltd.

Tensile strength, flexural strength, flexural modulus, impact strength, heat deflection temperature (1.82MPa) and thermal conductivity in each embodiment of the present invention are measured by the model and manufacturer information of the instrument used.

Universal electronic tensile testing machine: CMT6104, Shenzhen Xinsansi Group Company;

Izod impact tester: XJV5.5 type, Chengde Jinjian Testing Instrument Co., Ltd.;

Heat distortion temperature measuring instrument: XWB-300A type, Chengde Kecheng Testing Machine Co., Ltd.;

Multimeter: U1231A type, American Agilent Company.

Example 1

A conductive carbon fiber reinforced PET/polyester alloy, calculated by weight percentage, the composition and content of its raw materials are as follows:

PET is polyethylene terephthalate with a viscosity of 0.8-0.9dl/g;

The polyester is polyethylene 2,6-naphthalate;

The nucleating agent is Surlyn8920;

The conductive filler can be a mixture of one or more of natural flake graphite powder, artificial graphite powder, expanded graphite, carbon black and conductive metal powder;

The tensile strength of carbon fiber is 5200MPa, and the grade of carbon fiber is T700 grade;

The coupling agent is silane coupling agent KH-570;

The antioxidant is a mixture of antioxidant 168 and antioxidant 1010 in a ratio of 3:7;

The lubricant is paraffin.

The preparation method of above-mentioned a kind of conductive carbon fiber reinforced PET/polyester alloy specifically comprises the following steps:

(1), put 34.8% PET, 8.7% polyester, 45% conductive filler, 4% nucleating agent, 1% silane coupling agent, 1% antioxidant and 0.5% lubricant into the high mixer and mix for 5 minutes , and then added from the first barrel of the twin-screw extruder;

(2), 5% carbon fiber is added from the fourth section of the cylinder of the twin-screw extruder;

(3) Control the rotation speed of the twin-screw extruder to 1050 rpm and the temperature to 240° C. for extrusion and granulation to obtain conductive carbon fiber reinforced PET/polyester alloy.

Example 2

A conductive carbon fiber reinforced PET/polyester alloy, calculated by weight percentage, the composition and content of its raw materials are as follows:

PET is polyethylene terephthalate with a viscosity of 0.8-0.9dl/g;

The polyester is polytrimethylene terephthalate;

The nucleating agent is Surlyn8920;

The conductive filler can be a mixture of one or more of natural flake graphite powder, artificial graphite powder, expanded graphite, carbon black and conductive metal powder;

The tensile strength of carbon fiber is 5200MPa, and the grade of carbon fiber is T700 grade;

The compatibilizer is silane coupling agent KH-570;

The antioxidant is a mixture of antioxidant 168 and antioxidant 1010 in a ratio of 3:7;

The lubricant is polyethylene wax.

The preparation method of above-mentioned a kind of conductive carbon fiber reinforced PET/polyester alloy specifically comprises the following steps:

(1), put 37.4% PET, 6.6% polyester, 3% nucleating agent, 40% conductive filler, 1.5% coupling agent, 1% antioxidant and 0.5% lubricant into the high mixer and mix for 5 minutes, Then add it from the first barrel of the twin-screw extruder;

(2), 10% carbon fiber is added from the fourth section barrel of the twin-screw extruder;

(3) Control the rotation speed of the twin-screw extruder to 1100 rpm and the temperature to 245° C. for extrusion and granulation to obtain conductive carbon fiber reinforced PET/polyester alloy.

Example 3

A conductive carbon fiber reinforced PET/polyester alloy, calculated by weight percentage, the composition and content of its raw materials are as follows:

PET is polyethylene terephthalate with a viscosity of 0.8-0.9dl/g;

The polyester is polybutylene terephthalate;

The nucleating agent is Surlyn8920;

The conductive filler can be a mixture of one or more of natural flake graphite powder, artificial graphite powder, expanded graphite, carbon black and conductive metal powder;

The tensile strength of carbon fiber is 5200MPa, and the grade of carbon fiber is T700 grade;

The compatibilizer is silane coupling agent KH-570;

The antioxidant is a mixture of antioxidant 168 and antioxidant 1010 in a ratio of 3:7;

The lubricant is polyethylene wax.

The preparation method of above-mentioned a kind of conductive carbon fiber reinforced PET/polyester alloy specifically comprises the following steps:

(1), put 37.4% PET, 6.6% polyester, 40% conductive filler, 3% nucleating agent, 1.5% coupling agent, 1% antioxidant and 0.5% lubricant into the high mixer and mix for 5 minutes, Then add it from the first barrel of the twin-screw extruder;

(2), 10% carbon fiber is added from the fourth section barrel of the twin-screw extruder;

(3) Control the rotation speed of the twin-screw extruder to 1100 rpm and the temperature to 245° C. for extrusion and granulation to obtain conductive carbon fiber reinforced PET/polyester alloy.

Example 4

A conductive carbon fiber reinforced PET/polyester alloy, calculated by weight percentage, the composition and content of its raw materials are as follows:

PET is polyethylene terephthalate with a viscosity of 0.8-0.9dl/g;

The polyester is polytrimethylene terephthalate;

The nucleating agent is Surlyn8920;

The conductive filler can be a mixture of one or more of natural flake graphite powder, artificial graphite powder, expanded graphite, carbon black and conductive metal powder;

The tensile strength of carbon fiber is 5200MPa, and the grade of carbon fiber is T700 grade;

The coupling agent is silane coupling agent KH-570;

The antioxidant is antioxidant 1010;

The lubricant is a mixture of paraffin wax and polypropylene wax with a mass ratio of 1:1.

The preparation method of above-mentioned a kind of conductive carbon fiber reinforced PET/polyester alloy specifically comprises the following steps:

(1), put 35.2% PET, 8.8% polyester, 3% nucleating agent, 35% conductive filler, 1.5% coupling agent, 0.5% antioxidant and 1% lubricant into a high mixer and mix 3min, then added from the first barrel of the twin-screw extruder;

(2), 15% carbon fibers are added from the fourth section of the cylinder of the twin-screw extruder;

(3) Control the rotation speed of the twin-screw extruder to 1200 rpm and the temperature to 245° C. for extrusion and granulation to obtain conductive carbon fiber reinforced PET/polyester alloy.

Example 5

A conductive carbon fiber reinforced PET/polyester alloy, calculated by weight percentage, the composition and content of its raw materials are as follows:

PET is polyethylene terephthalate with a viscosity of 0.8-0.9dl/g;

The polyester is polybutylene terephthalate;

The nucleating agent is Surlyn8920;

The conductive filler can be a mixture of one or more of natural flake graphite powder, artificial graphite powder, expanded graphite, carbon black and conductive metal powder

The tensile strength of carbon fiber is 5200MPa, and the grade of carbon fiber is T700 grade;

The coupling agent is silane coupling agent KH-570;

The antioxidant is antioxidant 1010;

The lubricant is a mixture of paraffin wax and polypropylene wax with a mass ratio of 1:1.

The preparation method of above-mentioned a kind of conductive carbon fiber reinforced PET/polyester alloy specifically comprises the following steps:

(1), put 35.2% PET, 8.8% polyester, 3% nucleating agent, 35% conductive filler, 1.5% coupling agent, 0.5% antioxidant and 1% lubricant into the high mixer and mix for 4 minutes, Then add it from the first barrel of the twin-screw extruder;

(2), 15% carbon fibers are added from the fourth section of the cylinder of the twin-screw extruder;

(3) Control the rotation speed of the twin-screw extruder to 1200 rpm and the temperature to 245° C. for extrusion and granulation to obtain conductive carbon fiber reinforced PET/polyester alloy.

Example 6

A conductive carbon fiber reinforced PET/polyester alloy, calculated by weight percentage, the composition and content of its raw materials are as follows:

PET is polyethylene terephthalate with a viscosity of 0.8-0.9dl/g;

The polyester is polybutylene terephthalate;

The nucleating agent is Surlyn8920;

The conductive filler can be a mixture of one or more of natural flake graphite powder, artificial graphite powder, expanded graphite, carbon black and conductive metal powder,

The tensile strength of carbon fiber is 5200MPa, and the grade of carbon fiber is T700 grade;

The coupling agent is silane coupling agent KH-570;

The antioxidant is antioxidant 1010;

The lubricant is a mixture of polyethylene wax and polypropylene wax with a mass ratio of 1:1.

The preparation method of above-mentioned a kind of conductive carbon fiber reinforced PET/polyester alloy specifically comprises the following steps:

(1), put 40% PET, 4.5% polyester, 2% nucleating agent, 30% conductive filler, 2% coupling agent, 0.5% antioxidant and 1% lubricant into the high mixer and mix for 5 minutes, Then add it from the first barrel of the twin-screw extruder;

(2), 20% carbon fibers are added from the fourth section of the cylinder of the twin-screw extruder;

(3) Control the rotation speed of the twin-screw extruder to 1200 rpm, and carry out extrusion pelletization at a temperature of 250° C. to obtain conductive carbon fiber-reinforced PET/polyester alloy.

Measure the specific capacitance resistance according to the following conditions and equipment, use an injection molding machine to prepare samples according to ASTM, use a hacksaw or a razor to make incisions at both ends of the narrow parallel part of the tensile strip (ASTM D638) used, and use conductive silver paint on the two incisions Coating, let the silver paint dry naturally for more than 30 minutes or place it in an oven (70-100°C) for at least 5 minutes, measure the resistance with a multimeter, and use the size of the spline to calculate the specific capacitance resistance (SPV) = ( Measuring Resistance)(Width)(Thickness)/(Length).

Tensile strength, elongation at break, flexural strength, flexural modulus, specific capacitance resistance, impact strength, heat deflection temperature (1.82MPa), molding to the conductive carbon fiber reinforced PET/polyester alloy of above-mentioned embodiment 1-6 gained Shrinkage (disc) is detected, and the results are shown in the following table 1:

The physical property of the conductive carbon fiber reinforced PET/polyester alloy of table 1 embodiment 1-6 gained

It can be seen from Table 1 that with the increase of carbon fiber content, the tensile strength, flexural strength, flexural modulus, impact strength and heat distortion temperature of the obtained conductive carbon fiber reinforced PET/polyester alloy material increase accordingly. It shows that the carbon fiber content is positively correlated with the mechanical properties of PET polyester alloy,

Further, through the comparison of Examples 3, 5, and 6, it is found that under the same alloy matrix (both PET/PBT alloy), with the continuous reduction of the conductive filler content (from 4%-2.5%-1.5%) , the resistivity of the material did not increase, but decreased a lot. At the same time, the content of carbon fiber in the alloy continues to increase, which shows that carbon fiber has excellent electrical conductivity, which can effectively enhance the electrical conductivity of the material and reduce the resistivity of the alloy.

Further, by comparing Examples 2-3 and Examples 4-5, it is found that under the same conditions in other formulations, PET/PBT alloys have more advantages in mechanical properties, while PET/PTT alloys are relatively more conductive. better. This may be due to the different polyester chain structures, which lead to different viscosities of the polyesters, and the conductivity of the higher viscosity is poor. Therefore, different types of polyesters have different effects on the properties of PET alloys. In practical applications, appropriate polyesters should be selected to modify PET according to specific conditions.

In summary, a conductive carbon fiber reinforced PET/polyester alloy of the present invention has the characteristics of good mechanical properties, low resistivity, and low cost. The present invention adopts suitable nucleating agent, conductive filler and coupling agent, enhances the crystallization performance of polyester, improves the affinity between polyester and conductive filler, and improves the dispersibility and interfacial force of carbon fiber between resin matrices , thereby optimizing the processing performance, electrical conductivity and mechanical properties of the alloy, which can replace expensive special engineering plastics in some occasions, and has broad application prospects.

The above is only a preferred implementation case of the present invention, it should be noted that, for those of ordinary skill in the art, without departing from the method of the present invention, some supplements and improvements can also be made, and these supplements and improvements should also be It is regarded as the protection scope of the present invention.

Claims (10)

1. the fine conduction of carbon REINFORCED PET/polyester alloy, is characterized in that, this polyester alloy is prepared by the raw material of following component and weight part content:

PET60-70, polyester 5-20, nucleator 2-4, conductive filler material 0.5-10, carbon fiber 5-20, coupling agent 1-2, oxidation inhibitor 0.5-1, lubricant 0.5-1.

2. the fine conduction of a kind of carbon according to claim 1 REINFORCED PET/polyester alloy, is characterized in that, described PET is the polyethylene terephthalate of viscosity 0.8-0.9dl/g; Described polyester is Poly(Trimethylene Terephthalate), polybutylene terephthalate or polyethylene glycol 2，6-naphthalene dicarboxylate.

3. the fine conduction of a kind of carbon according to claim 1 REINFORCED PET/polyester alloy, is characterized in that, described nucleator is Surlyn resin; Described conductive filler material is selected from one or more in natural flake graphite powder, graphous graphite powder, expanded graphite, carbon black or conductive metal powder; Described carbon fiber is the carbon fiber of T700 grade, tensile strength 5200MPa; Described coupling agent is silane coupling agent; Described oxidation inhibitor is selected from one or both in irgasfos 168 or antioxidant 1010; Described lubricant is selected from one or both in paraffin, polyethylene wax or Poly Propylene Wax.

4. according to the fine conduction of a kind of carbon REINFORCED PET/polyester alloy described in any one in claim 1-3, it is characterized in that, the raw material of the preferred following component of polyester alloy and weight part content prepares:

PET65.8, polyester 17, nucleator 4, conductive filler material 5.7, carbon fiber 5, coupling agent 1, oxidation inhibitor 1, lubricant 0.5%;

Described polyester is polyethylene glycol 2，6-naphthalene dicarboxylate; Described nucleator is Surlyn resin; Described conductive filler material is selected from one or more in natural flake graphite powder, graphous graphite powder, expanded graphite, carbon black or conductive metal powder; Described carbon fiber grade is T700, tensile strength 5200MPa; Described coupling agent is silane coupling agent; Described oxidation inhibitor is that irgasfos 168 and antioxidant 1010 are the mixture of 3: 7 compositions in mass ratio; Described lubricant is paraffin.

5. according to the fine conduction of a kind of carbon REINFORCED PET/polyester alloy described in any one in claim 1-3, it is characterized in that, the raw material of the preferred following component of polyester alloy and weight part content prepares:

PET67.4, polyester 12.6, nucleator 3, conductive filler material 4, carbon fiber 10, coupling agent 1.5, oxidation inhibitor 1, lubricant 0.5%;

Described polyester is Poly(Trimethylene Terephthalate); Described nucleator is Surlyn resin; Described conductive filler material is selected from one or more in natural flake graphite powder, graphous graphite powder, expanded graphite, carbon black or conductive metal powder; Described carbon fiber grade is T700, tensile strength 5200MPa; Described coupling agent is silane coupling agent; Described oxidation inhibitor is that irgasfos 168 and antioxidant 1010 are the mixture of 3: 7 compositions in mass ratio; Described lubricant is polyethylene wax.

6. according to the fine conduction of a kind of carbon REINFORCED PET/polyester alloy described in any one in claim 1-3, it is characterized in that, the raw material of the preferred following component of polyester alloy and weight part content prepares:

PET67.4, polyester 12.6, nucleator 3, conductive filler material 4, carbon fiber 10, coupling agent 1.5, oxidation inhibitor 1, lubricant 0.5%;

Described polyester is polybutylene terephthalate; Described nucleator is Surlyn resin; Described conductive filler material is selected from one or more in natural flake graphite powder, graphous graphite powder, expanded graphite, carbon black, carbon nanotube or conductive metal powder; Described carbon fiber grade is T700, tensile strength 5200MPa; Described coupling agent is silane coupling agent; Described oxidation inhibitor is that irgasfos 168 and antioxidant 1010 are the mixture of 3: 7 compositions in mass ratio; Described lubricant is polyethylene wax.

7. according to the fine conduction of a kind of carbon REINFORCED PET/polyester alloy described in any one in claim 1-3, it is characterized in that, the raw material of the preferred following component of polyester alloy and weight part content prepares:

PET61.2, polyester 15.3, nucleator 3, conductive filler material 2.5, carbon fiber 15, coupling agent 1.5, oxidation inhibitor 0.5, lubricant 1%;

Described polyester is Poly(Trimethylene Terephthalate); Described nucleator is Surlyn resin; Described conductive filler material is generally by one or more in natural flake graphite powder, graphous graphite powder, expanded graphite, carbon black or conductive metal powder; Described carbon fiber grade is T700, tensile strength 5200MPa; Described coupling agent is silane coupling agent; Described oxidation inhibitor is antioxidant 1010; Described lubricant is that paraffin and Poly Propylene Wax are the mixture of 1: 1 composition in mass ratio.

8. according to the fine conduction of a kind of carbon REINFORCED PET/polyester alloy described in any one in claim 1-3, it is characterized in that, the raw material of the preferred following component of polyester alloy and weight part content prepares:

PET61.2, polyester 15.3, nucleator 3, conductive filler material 2.5, carbon fiber 15, coupling agent 1.5, oxidation inhibitor 0.5, lubricant 1%;

Described polyester is polybutylene terephthalate; Described nucleator is Surlyn resin; Described conductive filler material is selected from one or more in natural flake graphite powder, graphous graphite powder, expanded graphite, carbon black or conductive metal powder; Described carbon fiber grade is T700, tensile strength 5200MPa; Described coupling agent is silane coupling agent; Described oxidation inhibitor is antioxidant 1010; Described lubricant is that paraffin and Poly Propylene Wax are the mixture of 1: 1 composition in mass ratio.

9. according to the fine conduction of a kind of carbon REINFORCED PET/polyester alloy described in any one in claim 1-3, it is characterized in that, the raw material of the preferred following component of polyester alloy and weight part content prepares:

PET65.6, polyester 7.4, nucleator 2, conductive filler material 1.5, carbon fiber 20, coupling agent 2, oxidation inhibitor 0.5, lubricant 1;

Described polyester is polybutylene terephthalate; Described nucleator is Surlyn resin; Described conductive filler material is selected from one or more in natural flake graphite powder, graphous graphite powder, expanded graphite, carbon black or conductive metal powder; Described carbon fiber grade is T700, tensile strength 5200MPa; Described coupling agent is silane coupling agent; Described oxidation inhibitor is antioxidant 1010; Described lubricant is that polyethylene wax and Poly Propylene Wax are the mixture of 1: 1 composition in mass ratio.

10. according to the preparation method of the fine conduction of the carbon described in any one in claim 1-9 REINFORCED PET/polyester alloy, it is characterized in that, the method adopts following steps:

(1) PET, polyester, nucleator, conductive filler material, coupling agent, oxidation inhibitor and lubricant are put into high-speed mixer and mixing 3-5min, then added by twin screw extruder first paragraph cylindrical shell;

(2) carbon fiber is added by the 4th section of cylindrical shell of twin screw extruder;

(3) rotating speed of control twin screw extruder is 1050-1200rpm, and temperature is 240-250 DEG C and carries out extruding pelletization, prepares conductive carbon fibres REINFORCED PET/polyester alloy.