Preparation method of anti-static nylon composite high polymer material

Abstract

The invention relates to a preparation method of an anti-static nylon composite high polymer material, and aims to provide a material with low cost and good anti-static effect. The method comprises the following steps: firstly, pre-oxidizing a carbon nano tube in an air atmosphere to obtain a pre-oxidized carbon nano tube; secondly, dividing a nylon high polymer material into two parts, and respectively mixing the two parts with a lubricant, an antioxidant, the pre-oxidized carbon nanotubes and graphite; and finally, mixing the two parts of mixed materials, and mixing again to obtain the anti-static nylon master batch. The obtained anti-static nylon master batch can be mixed with a nylon polymer master batch in any proportion to prepare an anti-static nylon composite polymer material. The preparation method adopted by the invention is simple, does not need excessive chemical modifiers, is relatively low in cost, can improve the conductivity of nylon with a relatively low additive amount, and meanwhile, the linear carbon nanotubes and the planar graphite have a synergistic effect to form a three-dimensional network, so that the conductivity is further improved.

Description

Technical Field

[0001] The invention relates to the field of polymer materials, in particular to the application field of antistatic materials. Background Art

[0002] Antistatic nylon material is a composite material based on nylon. It achieves antistatic properties by adding specific conductive fillers or additives. It inherits the characteristics of nylon such as high mechanical strength, superior wear resistance, chemical resistance and good dimensional stability. In addition, due to the uniform distribution of fillers, its resistivity is low and balanced. Even after mechanical processing or surface wear, the resistivity is not affected. It is widely used in semiconductors, LCDs, electronic components and other fields, and is used for storage trays, pads, rollers, bushings and other parts. During preparation, a specific method is used to ensure the uniform distribution of conductive fillers and strong coupling with nylon substrates to avoid the precipitation of conductive fillers, thereby ensuring the durability of antistatic properties. With the development of the electronics industry, the demand for antistatic materials is growing, especially in the fields of precision electronic components and semiconductor manufacturing. Antistatic nylon materials can reduce the damage of static electricity to products such as chips. The traditional practice is to add metal particles or carbon fibers and carbon black materials to nylon, but the density of metal particles is large, which greatly increases the weight of the product. Although carbon fibers have a certain conductivity, they are not conductive enough and require a sufficiently large amount of addition, resulting in increased costs. Although carbon black has low cost, it can easily destroy the nylon structure and cause powder loss due to the large amount added.

[0003] In view of the above problems, a material with low cost and good antistatic effect is urgently needed. Summary of the invention

[0004] The present invention aims to provide a method for preparing an antistatic nylon polymer material. The method uses pre-oxidized carbon nanotubes, which are rich in a variety of oxygen-containing functional groups and can form chemical bonds with nylon, so that the carbon nanotubes can be better dispersed. The modification method is simple and does not require the addition of any such machine. Graphite itself has a good lubricant and can be well dispersed without modification. The carbon nanotubes and graphite are separately compounded with nylon, which can also prevent uneven dispersion caused by graphite sheets hindering the movement of the carbon nanotubes or chemical grafting of graphite with the oxygen-containing functional groups of the carbon nanotubes.

[0005] The present invention provides a method for preparing an antistatic nylon composite polymer material, and the specific scheme is as follows:

[0006] A method for preparing an antistatic nylon composite polymer material comprises the following steps:

[0007] (1) pre-oxidizing carbon nanotubes in an air atmosphere to obtain pre-oxidized carbon nanotubes;

[0008] (2) dividing the nylon polymer material into two parts, mixing the lubricant, antioxidant, and pre-oxidized carbon nanotubes with one part of the nylon polymer material, and mixing the lubricant, antioxidant, and graphite with the other part of the nylon polymer material;

[0009] (3) The two mixed materials are mixed and mixed again to obtain an antistatic nylon masterbatch; the obtained antistatic nylon masterbatch is mixed with a nylon polymer masterbatch in any proportion to prepare an antistatic nylon composite polymer material.

[0010] In the step (1), the carbon nanotubes are one or more of single-walled, few-walled or multi-walled.

[0011] In the step (1), the pre-oxidation of the carbon nanotubes is carried out in a tubular furnace at a temperature of 400-500°C.

[0012] In the step (2), the lubricant is one or more of paraffin oil, polyethylene wax, oxidized polyethylene wax, stearamide, polyethylene glycol, polyacrylic acid or silicate.

[0013] The antioxidant in step (2) is one or more of hindered phenols, phosphites, and thio oxidants.

[0014] In the step (2), the nylon polymer material is one of PA6, PA66 and PA12.

[0015] The mixing temperature in the step (2) is 230°C to 300°C.

[0016] In the step (2), the pre-oxidized carbon nanotubes and the nylon polymer material are mixed in a mass ratio of 1:9, and the graphite and the nylon polymer material are mixed in a mass ratio of 3:7.

[0017] Beneficial effects of the present invention:

[0018] The present invention adopts a simple modification process, and only needs to pre-oxidize the carbon nanotubes in the air to have good chemical compatibility with the amide bonds of nylon, etc., and the carbon nanotubes themselves have low density and high conductivity, and can improve the conductivity of nylon with a relatively low addition amount, and the linear carbon nanotubes and the planar graphite synergistically form a three-dimensional network to further improve the conductivity. The present invention has a simple process, does not require too much chemical modifier, and has a low cost.

[0019] The present invention uses pre-oxidized carbon nanotubes. After oxidation, the carbon nanotubes will have more hydroxyl and carboxyl functional groups on their surfaces. The generated functional groups can chemically react with some functional groups of the polymer in the subsequent mixing. It is not just a simple physical mixing, but can partially undergo a condensation reaction and be better grafted on the polymer surface. Specific implementation methods

[0021] In order to make the purpose, technical scheme and technical effect of the embodiments of the present invention clearer, the technical scheme in the embodiments of the present invention is clearly and completely described. The embodiments described below are part of the embodiments of the present invention, rather than all of the embodiments. In conjunction with the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. If the specific conditions are not specified in the embodiments, they are carried out according to conventional conditions or the conditions recommended by the manufacturer; if the manufacturer of the reagents or instruments is not specified, they are all conventional products that can be purchased commercially.

[0022] In the description of the present invention, the term "and / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. A and B can be singular or plural. The character " / " generally indicates that the associated objects before and after are in an "or" relationship.

[0023] In the description of the present invention, "at least one" means one or more, and "plurality" means two or more. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single items or plural items. For example, "at least one of a, b, or c", or "at least one of a, b, and c" can all mean: a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, c can be single or multiple, respectively.

[0024] It should be understood that the weight of the relevant components mentioned in the embodiments of the present invention can not only refer to the specific content of each component, but also represent the proportional relationship between the weights of the components. Therefore, as long as the content of the relevant components in the embodiments of the present invention is proportionally enlarged or reduced, it is within the scope disclosed by the present invention. Specifically, the weight described in the embodiments of the present invention can be a mass unit known in the chemical industry such as μg, mg, g, kg, etc.

[0025] In addition, unless the context clearly uses otherwise, the expression of the singular form of a word should be understood to include the plural form of the word. The term "includes" or "having" is intended to specify the existence of a feature, quantity, step, operation, element, part or combination thereof, but is not used to exclude the existence or possible addition of one or more other features, quantities, steps, operations, elements, parts or combinations thereof.

[0026] The technical solution adopted by the present invention is to provide a method for preparing an antistatic nylon polymer material, and the specific implementation steps are as follows:

[0027] Step 1: pre-oxidizing the carbon nanotubes in an air atmosphere to obtain pre-oxidized carbon nanotubes;

[0028] Step 2: Divide the nylon polymer material into two parts, add lubricant and antioxidant, mix the pre-oxidized carbon nanotubes with one part of the nylon polymer material, and mix the graphite with the other part of the nylon polymer material;

[0029] Step 3: Mix the two mixed materials and mix them again to obtain antistatic nylon masterbatch;

[0030] The obtained antistatic nylon masterbatch can be mixed with nylon polymer masterbatch in any proportion to prepare antistatic nylon composite polymer material;

[0031] The present invention adopts a simple modification process, and only needs to pre-oxidize the carbon nanotubes in the air to have good chemical compatibility with nylon. The carbon nanotubes themselves have low density and high conductivity, and can improve the conductivity of nylon with a relatively low addition amount. The linear carbon nanotubes and the planar graphite cooperate to form a three-dimensional network, which can further improve the conductivity. The present invention has a simple process, does not require too much chemical modifier, and has a low cost.

[0032] The content of carbon nanotubes in the antistatic nylon polymer material can be any value from 0 to 10%, such as 0.1%, 0.2%, 0.5%, 1%, 2%, 3%, 4%, 5%, etc., and the content of graphite can be any value from 0 to 30%, such as 1%, 2%, 3%, 5%, 10%, 15%, etc.

[0033] Specifically, the carbon nanotubes are pre-oxidized by continuously introducing air into the furnace at 480° C., and the oxygen content of the pre-oxidized carbon nanotubes is controlled to be 5% to 10%.

[0034] Specifically, the carbon nanotubes are single-walled carbon nanotubes;

[0035] Specifically, the pre-oxidized carbon nanotubes and the nylon polymer material are mixed in a mass ratio of 1:9, and the graphite and the nylon polymer material are mixed in a mass ratio of 3:7;

[0036] Specifically, the pre-oxidized carbon nanotube mixture and the graphite mixture are mixed in a ratio of 1:1.

[0037] In order to enable those skilled in the art to clearly understand the implementation details and operations of the present invention, and to significantly demonstrate the improved performance of the embodiments of the present invention, the above technical solutions are illustrated by multiple embodiments below.

[0038] Example 1

[0039] 10g of single-walled carbon nanotubes were placed in a tube furnace (temperature of 400-500°C), and air was introduced at a rate of 200ml / min to obtain pre-oxidized carbon nanotubes. Then 43.65g of PA6 raw material, 4.85g of pre-oxidized carbon nanotubes, 1g of lubricant (polyethylene wax), and 0.5g of antioxidant (antioxidant 1010) were put into a mixer and mixed for 10min to obtain a mixed material; 33.95g of PA6 raw material, 14.55g of graphite, 1g of lubricant, and 0.5g of antioxidant were put into another mixer and mixed for 10min to obtain a mixed material.

[0040] 5 g of each of the above two mixed materials was mixed with 90 g of PA6 raw material for 10 min to obtain an antistatic nylon polymer material, and the performance was tested after injection molding.

[0041] Comparative Example 1

[0042] 0.05 g of single-walled carbon nanotubes, 1 g of graphite, 0.2 g of lubricant, 0.1 g of antioxidant, and 98.65 g of PA6 raw material were mixed for 20 minutes, and the obtained material was tested for performance after injection molding.

[0043] Table 1

[0044] Surface resistivity Tensile Strength Example 1 <![CDATA[6.2×10 6 Ohm / sq]]> 83MPa Comparative Example 1 <![CDATA[8.6×10 9 Ohm / sq]]> 84MPa

[0045] As shown in Table 1, the present invention can disperse carbon nanotubes and graphite well through a simple process. In Comparative Example 1, the material is subjected to the flow of plastic melt during injection molding, and the internal stress caused by the temperature difference causes the carbon nanotubes and graphite to agglomerate.

[0046] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit the scope of protection of the present invention. Although the present invention is described in detail with reference to the preferred embodiments, it is not limited to those listed in the embodiments. Those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the essence and scope of the technical solution of the present invention.

Claims

1. A method for preparing an antistatic nylon composite polymer material, characterized in that: The steps include: (1) pre-oxidizing carbon nanotubes in an air atmosphere to obtain pre-oxidized carbon nanotubes; (2) dividing the nylon polymer material into two parts, mixing the lubricant, antioxidant, and pre-oxidized carbon nanotubes with one part of the nylon polymer material, and mixing the lubricant, antioxidant, and graphite with the other part of the nylon polymer material; (3) The two mixed materials are mixed and then mixed again to obtain an antistatic nylon masterbatch; the obtained antistatic nylon masterbatch is mixed with a nylon polymer masterbatch in any proportion to prepare an antistatic nylon composite polymer material.

2. The method for preparing an antistatic nylon composite polymer material according to claim 1, characterized in that: In the step (1), the carbon nanotubes are one or more of single-walled, few-walled or multi-walled.

3. The method for preparing an antistatic nylon composite polymer material according to claim 1, characterized in that: In the step (1), the pre-oxidation of the carbon nanotubes is carried out in a tubular furnace, and the temperature of the tubular furnace is 400-500°C.

4. The method for preparing an antistatic nylon composite polymer material according to claim 1, characterized in that: In the step (2), the lubricant is one or more of paraffin oil, polyethylene wax, oxidized polyethylene wax, stearamide, polyethylene glycol, polyacrylic acid or silicate.

5. The method for preparing an antistatic nylon composite polymer material according to claim 1, characterized in that: The antioxidant in step (2) is one or more of hindered phenols, phosphites, and thio oxidants.

6. The method for preparing an antistatic nylon composite polymer material according to claim 1, characterized in that: In the step (2), the nylon polymer material is one of PA6, PA66 and PA12.

7. The method for preparing an antistatic nylon composite polymer material according to claim 1, characterized in that: The mixing temperature in step (2) is 230°C to 300°C.

8. The method for preparing an antistatic nylon composite polymer material according to claim 1, characterized in that: In the step (2), the pre-oxidized carbon nanotubes and the nylon polymer material are mixed in a mass ratio of 1:9, and the graphite and the nylon polymer material are mixed in a mass ratio of 3:7.