Electrically conductive reinforced flame retardant pbt material and method for producing the same

Abstract

The present application relates to a kind of electrically conductive reinforced flame-retardant PBT materials, the electrically conductive reinforced flame-retardant PBT material includes the following mass fraction of ingredients: PBT resin 50-70 parts, modified compatilizer 15-30 parts, halogen-free flame retardant 10-20 parts, auxiliary 0.1-2 parts;Wherein, the modified compatilizer is PE, glycidyl methacrylate, the ternary random copolymer obtained by high-temperature melting of carbon nanotube grafted acrylate.This application's modified compatilizer, with PBT resin and flame retardant and other ingredients, has good compatibilization, improves the combination effect between various components, while ensuring the mechanical properties of composite material, gives product better electrically conductive, flame-retardant capacity, overcome the defects existing in the prior art product.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of high polymer composite materials, in particular to a conductive reinforced flame-retardant PBT material and a preparation method thereof. BACKGROUND

[0002] PBT (polybutylene terephthalate) is an economical and multi-application aromatic polyester material, which is a key thermoplastic polyester and belongs to the five major engineering plastics. PBT has excellent mechanical strength, outstanding thermal stability, and strong water resistance, and is widely used in many industries such as electrical, aviation, communication, vehicle, and household appliances.

[0003] By adding carbon fibers, metal powders and other substances, PBT conductive materials can be produced, which have better conductivity and antistatic properties while maintaining the original properties of PBT, and can be applied to various fields such as anti-static instruments, anti-static packaging, high-precision workbenches, and conductive components.

[0004] There are also many reports on the fire-retardant performance of PBT materials. The use of flame retardants with PBT can effectively improve the fire resistance of the composite material, significantly reduce the flame spread rate, and even achieve self-extinguishing under certain conditions. By adding an appropriate amount of flame retardant, the PBT flame-retardant material can reach the UL94 V-0 level of flame retardant standard, thereby greatly improving the safety of the product.

[0005] However, directly adding a large amount of conductive substances or flame retardants to PBT resin has the problem of low compatibility between multiple components, resulting in insufficient material stability, and the electrical properties, fire resistance, and mechanical strength of the composite material are difficult to achieve ideal levels. Therefore, how to develop a PBT composite material with strong electrical properties, flame retardant properties, and mechanical properties is a problem faced by the field.

[0006] In summary, there is an urgent need to develop a new technical solution to solve the problems in the prior art. SUMMARY

[0007] Therefore, the present application develops a conductive reinforced flame-retardant PBT material. The modified compatibilizer obtained by the reaction of PE (polyethylene), glycidyl methacrylate, and carbon nanotube grafted acrylate is used as a component, which is compounded with PBT resin and flame retardant components, has good compatibilization effect, improves the combination effect between multiple components, ensures the mechanical properties of the composite material, and gives the product better conductivity and flame retardant capacity, overcoming the defects in the existing products.

[0008] An object of the present application is to provide a conductive reinforced flame-retardant PBT material comprising ingredients in the following mass fractions:

[0009] PBT resin 50-70 parts

[0010] Modified compatibilizer 15-30 parts

[0011] Halogen-free flame retardant 10-20 parts

[0012] Auxiliary agent 0.1-2 parts

[0013] wherein,

[0014] The modified compatibilizer is a ternary random copolymer obtained by high-temperature melting of PE, glycidyl methacrylate, and carbon nanotube grafted acrylate.

[0015] Further, the mass ratio of the PE, glycidyl methacrylate, and carbon nanotube grafted acrylate is (80-100):(1-10):(60-100).

[0016] Further, the halogen-free flame retardant is selected from one or more of phosphates, hypophosphite salts, or dihypophosphite salts.

[0017] Further, the auxiliary agent includes nucleating agents, antioxidants, and dispersants.

[0018] Another object of the present application is to provide a preparation method of the conductive reinforced flame-retardant PBT material described above, comprising the following steps:

[0019] S1. Preparation of carbon nanotube grafted acrylate:

[0020] Hydroxylated carbon nanotubes are added to acrylate, and ultrasonic heating is performed to obtain carbon nanotube grafted acrylate;

[0021] S2. Preparation of modified compatibilizer:

[0022] PE, glycidyl methacrylate, carbon nanotube grafted acrylate, and initiator are uniformly mixed and added to a twin-screw extruder for melt reaction, followed by extrusion, cooling, and granulation to obtain a modified compatibilizer of ternary random copolymer;

[0023] S3. Preparation of conductive reinforced flame-retardant PBT material:

[0024] The modified compatibilizer, PBT resin, halogen-free flame retardant, and auxiliary agent are added to a twin-screw extruder for melt extrusion, cooling, and granulation to obtain a conductive reinforced flame-retardant PBT material.

[0025] Further, in step S1, the ultrasonic heating temperature is 60-100°C.

[0026] Further, in step S2, the temperature of the melt reaction is 160-190℃.

[0027] Further, in step S3, the temperature of the melt extrusion is 220-250℃.

[0028] The present application has the following beneficial effects:

[0029] The conductive reinforced flame-retardant PBT material provided by the present application is compounded by using a modified compatilizer, PBT resin, flame retardant and other components. The modified compatilizer is first obtained by adding hydroxylated carbon nanotubes into acrylic acid for reaction to introduce double bond functional groups, and then further melt reacting with PE and glycidyl methacrylate to obtain a terpolymer. The modified compatilizer obtained in this way grafts carbon nanotubes, PE and glycidyl methacrylate through covalent bonds. On the one hand, this component is mainly based on carbon nanotubes, has good conductivity, and also has certain flame-retardant and reinforcing functions. After the introduction of active vinyl and epoxy groups, the interfacial bonding force and compatibility between the organic resin can be improved, thereby improving the uniformity and stability of the composite material, avoiding the agglomeration phenomenon caused by the incompatibility between organic and inorganic components, and being conducive to enhancing the mechanical properties, conductivity and flame retardancy of the product. On the other hand, after the modified compatilizer is combined with the matrix resin through chemical bonds, a more compact and three-dimensional network crosslinked structure can be formed, thereby further improving the toughness and strength of the PBT composite material. The conductive and flame-retardant components uniformly combined and distributed in the organic resin can also effectively play the dielectric and flame-retardant functions. Therefore, the conductive reinforced flame-retardant PBT material of the present application not only ensures the electrical and flame-retardant ability of the product, but also improves the mechanical strength of the composite material, and has good application prospect. DETAILED DESCRIPTION

[0030] In order to more clearly illustrate the technical solutions of the present application, the following examples are listed. The raw materials, reactions and post-treatment methods appearing in the examples are all common raw materials on the market and technical means well known to those skilled in the art, unless otherwise stated.

[0031] The words "preferred", "preferably", "more preferred", etc. in the present application refer to the embodiments of the present application which can provide certain beneficial effects in certain cases. However, other embodiments can also be preferred in the same or other cases. In addition, the description of one or more preferred embodiments does not imply that other embodiments are not usable, nor is it intended to exclude other embodiments from the scope of the present application.

[0032] It should be understood, that, except in any operating examples, or otherwise indicated herein and that the statement of amounts of ingredients or of all numbers in the specification and claims, for example, are understood as being preceded by the word "about". It is also to be understood that the numerical parameters set forth in the following description and attached claims are approximations that can vary depending upon the desired properties sought to be obtained in accordance with the present application.

[0033] The PBT resin in the embodiment of the present application is BASF PBT B-4500.

[0034] The halogen-free flame retardant in the embodiment of the present application is triphenyl phosphate and aluminum diethyl phosphinate with a mass ratio of 1:1.

[0035] The nucleating agent in the embodiment of the present application is NA-21.

[0036] The antioxidant in the embodiment of the present application is antioxidant 1010.

[0037] The dispersing agent in the embodiment of the present application is pentaerythritol stearate.

[0038] The hydroxylated carbon nanotube in the embodiment of the present application has a hydroxyl content of 4wt%, and is purchased from Xi'an Qiyue Biological Technology Co., Ltd.

[0039] The PE in the embodiment of the present application is linear low density polyethylene, and is purchased from Maoming Branch of China Petroleum Chemical Industry Co., Ltd.

[0040] The fraction in the present application refers to mass fraction, unless otherwise specified.

[0041] Example 1

[0042] A conductive reinforced flame-retardant PBT material, comprising the following components in mass fraction:

[0043]

[0044]

[0045] The preparation method of the conductive reinforced flame-retardant PBT material comprises the following steps:

[0046] S1, preparation of carbon nanotube grafted acrylate:

[0047] The hydroxylated carbon nanotube is immersed in acrylic acid, and ultrasonic reaction is carried out at 80℃ for 12h, and after filtration, washing and drying, carbon nanotube grafted acrylate is obtained;

[0048] S2, preparation of modified compatibilizer:

[0049] The PE, glycidyl methacrylate, carbon nanotube grafted acrylate and di-tert-butyl peroxide isopropyl benzene with a mass ratio of 80:7:90:2 are uniformly mixed, added to a twin-screw extruder, melt reacted at 160-190°C, then extruded, cooled, and pelletized to obtain a modified compatilizer of a ternary random copolymer;

[0050] S3, Preparation of the conductive reinforced flame-retardant PBT material:

[0051] According to the above mass fraction, the modified compatilizer, PBT resin, halogen-free flame retardant, nucleating agent, antioxidant, and dispersant are added to a twin-screw extruder, melt extruded at 220-240°C, cooled, and pelletized to obtain the conductive reinforced flame-retardant PBT material.

[0052] Example 2

[0053] A conductive reinforced flame-retardant PBT material includes the following components in the following mass fractions:

[0054]

[0055] The preparation method of the above conductive reinforced flame-retardant PBT material includes the following steps:

[0056] S1, Preparation of carbon nanotube grafted acrylate:

[0057] The hydroxylated carbon nanotube is immersed in acrylic acid, ultrasonically reacted at 80°C for 12h, filtered, washed, and dried to obtain carbon nanotube grafted acrylate;

[0058] S2, Preparation of the modified compatilizer:

[0059] The PE, glycidyl methacrylate, carbon nanotube grafted acrylate, and di-tert-butyl peroxide isopropyl benzene with a mass ratio of 80:7:90:2 are uniformly mixed, added to a twin-screw extruder, melt reacted at 160-190°C, then extruded, cooled, and pelletized to obtain a modified compatilizer of a ternary random copolymer;

[0060] S3, Preparation of the conductive reinforced flame-retardant PBT material:

[0061] According to the above mass fraction, the modified compatilizer, PBT resin, halogen-free flame retardant, nucleating agent, antioxidant, and dispersant are added to a twin-screw extruder, melt extruded at 220-240°C, cooled, and pelletized to obtain the conductive reinforced flame-retardant PBT material.

[0062] Example 3

[0063] A conductive reinforced flame-retardant PBT material includes the following components in the following mass fractions:

[0064]

[0065] The preparation method of the conductive reinforced flame-retardant PBT material comprises the following steps:

[0066] S1, preparation of carbon nanotube grafted acrylate:

[0067] The hydroxylated carbon nanotubes are immersed in acrylic acid, and ultrasonic reaction is carried out at 80 DEG C for 12 h, and after filtration, washing and drying, the carbon nanotube grafted acrylate is obtained;

[0068] S2, preparation of modified compatilizer:

[0069] The PE, glycidyl methacrylate, carbon nanotube grafted acrylate and bis-tert-butyl peroxide isopropyl benzene with a mass ratio of 80:8:90:2 are uniformly mixed, added to a double screw extruder, and melt reacted at 160-190 DEG C, and then extruded, cooled and granulated to obtain a modified compatilizer of ternary random copolymer;

[0070] S3, preparation of conductive reinforced flame-retardant PBT material:

[0071] According to the above mass fraction, the modified compatilizer, PBT resin, halogen-free flame retardant, nucleating agent, antioxidant and dispersant are added to a double screw extruder, melt extruded at 220-240 DEG C, cooled, and granulated to obtain a conductive reinforced flame-retardant PBT material.

[0072] Comparative Example 1

[0073] A PBT material, the difference between this comparative example and Example 1 is that step S1 is omitted, and the carbon nanotube grafted acrylate is replaced by equal mass of carbon nanotubes, and the other components are the same as Example 1.

[0074] Comparative Example 2

[0075] A PBT material, the difference between this comparative example and Example 1 is that steps S1 and S2 are omitted, and the modified compatilizer is replaced by a physical mixture of PE and carbon nanotubes with a mass ratio of 1:1, and the other components and preparation method are the same as Example 1.

[0076] Test Example

[0077] Test method:

[0078] The PBT materials prepared in the examples and comparative examples are tested for performance according to standards such as ASTM-D638, ASTM-D256, UL-94, etc.

[0079] The test results are shown in Table 1:

[0080] Table 1 Performance test results

[0081] Item Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Tensile strength / MPA 126 119 123 99 82 Flexural strength / MPA 177 172 175 154 121 Impact strength / KJ / m 2 ]] 11.2 11.0 11.1 10.2 8.4 Flame retardancy V-0 V-0 V-0 V-1 V-1 Surface resistance / Ω 10 5 ]] 10 5 ]] 10 5 ]] 10 6 ]] 10 6 ]]

[0082] The test results show that the conductive reinforced flame-retardant PBT material prepared in the embodiment has good mechanical strength, excellent flame retardancy and lower surface resistance, while the comparative examples 1-2 replace the modified compatibilizer with carbon nanotubes, PE, glycidyl methacrylate melt reactant or a mixture of carbon nanotubes and PE, which leads to a significant decrease in the compatibility between components, easier aggregation of components, difficulty in uniform dispersion, and inability to obtain a three-dimensional structure formed by cross-linking of multiple components, resulting in different degrees of reduction in the mechanical properties, flame retardancy and dielectric properties of the composite material. In summary, the conductive reinforced flame-retardant PBT material of the present application solves the problems and defects of the prior art, and has important significance for the further development and application of PBT materials.

[0083] It will be obvious to a person skilled in the art that, as the application is not limited to the details of the exemplary embodiments described above, the application can be implemented in other concrete forms without departing from the spirit or essential characteristics of the application. Therefore, the embodiments should be considered in all respects as illustrative and not restrictive, and the scope of the application should be defined by the appended claims rather than the above description, and it is intended to encompass all changes falling within the meaning and scope of the equivalent elements of the claims.

[0084] Furthermore, it should be understood that, although the present specification is described in terms of embodiments, not every embodiment contains only one independent technical solution, and the present specification is described in this way only for the sake of clarity, and a person skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by a person skilled in the art.

Claims

1. An electrically conductive reinforced flame retardant PBT material, characterized in that, The conductive reinforced flame-retardant PBT material comprises ingredients in the following mass fractions: wherein, The modified compatilizer is a ternary random copolymer obtained by high-temperature melting of PE, glycidyl methacrylate, and carbon nanotube grafted acrylate.

2. The electrically conductive, reinforced, flame retardant PBT material of claim 1, wherein, The mass ratio of the PE, glycidyl methacrylate, and carbon nanotube grafted acrylate is (80-100):(1-10):(60-100).

3. The electrically conductive, reinforced, flame retardant PBT material of claim 1, wherein, The halogen-free flame retardant is selected from one or more of phosphates, hypophosphite, or diphosphite.

4. The electrically conductive, reinforced, flame retardant PBT material of claim 1, wherein, The auxiliary agents include nucleating agents, antioxidants, and dispersants.

5. Process for the preparation of the electrically conductive reinforced flame retardant PBT material according to any one of claims 1 to 4, characterized in that, The method comprises the following steps: S1. Preparation of carbon nanotube grafted acrylate: Hydroxylated carbon nanotubes are added to acrylate and heated by ultrasonic to obtain carbon nanotube grafted acrylate; S2. Preparation of modified compatilizer: PE, glycidyl methacrylate, carbon nanotube grafted acrylate, and initiator are mixed uniformly and added to a twin-screw extruder for melt reaction, then extruded, cooled, and granulated to obtain the modified compatilizer of the ternary random copolymer; S3. Preparation of conductive reinforced flame-retardant PBT material: The modified compatilizer, PBT resin, halogen-free flame retardant, and auxiliary agents are added to a twin-screw extruder for melt extrusion, then cooled and granulated to obtain the conductive reinforced flame-retardant PBT material.

6. The process for preparing electrically conductive reinforced flame retardant PBT material according to claim 5, characterized in that, In step S1, the temperature of the ultrasonic heating is 60-100℃.

7. The method for preparing the conductive reinforced flame-retardant PBT material according to claim 5, characterized in that, In step S2, the temperature of the melt reaction is 160-190℃.

8. The process for preparing electrically conductive reinforced flame retardant PBT material as claimed in claim 5, wherein, In step S3, the temperature of the melt extrusion is 220-250℃.

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