Preparation method of light-color ESD (Electro-Static Discharge) electrostatic protection material

Abstract

The invention discloses a preparation method of a light-color ESD (Electro-Static Discharge) electrostatic protection material, and relates to the field of electrostatic protection materials, and the preparation method specifically comprises the following operation steps: S1, preparing raw materials including a polymer matrix, a conductive filler, a flexibilizer and an auxiliary agent; s2, performing pretreatment; s3, carrying out blending treatment; and S4, injection molding. According to the preparation method of the light-color ESD electrostatic protection material, the problem of color limitation can be solved, the resistivity is accurately regulated and controlled to 1E5-1E9 omega / sq, the strict electrostatic protection requirement of the microelectronic industry is met, uniform dispersion of filler under high filling is achieved through silane coupling agent pretreatment and a segmented screw shearing process, and the light-color ESD electrostatic protection material is obtained. According to the present invention, the composite material has characteristics of uniform particle size distribution and uniform particle size distribution, can avoid the performance fluctuation caused by agglomeration, can balance the heat resistance and the processing fluidity by using the polybutylene terephthalate, the polycarbonate / polybutylene terephthalate alloy and the polyether-ether-ketone, is suitable for precision injection molding, and can effectively improve the yield by simplifying the formula through the single conductive filler system.

Description

Technical Field

[0001] The present invention relates to the field of electrostatic protection materials, and particularly to a preparation method of a light-colored ESD electrostatic protection material. Background Art

[0002] Electrostatic protection plastics are plastics used to prevent electrostatic accumulation and are widely used in electrostatic protection in fields such as electronic devices, aerospace, and military equipment. The accumulation of static electricity may cause damage to electronic devices, loss of data, and even lead to safety accidents. Therefore, the research and application of electrostatic protection plastics have received extensive attention.

[0003] Existing electrostatic protection plastics mainly achieve this by adding carbon-based conductive fillers such as carbon black, carbon fiber, graphite, and carbon nanotubes to polymers. These conductive fillers can provide good electrical conductivity, thus effectively preventing the accumulation of static electricity. However, a major drawback of these plastics is that they are darker in color, usually black, which limits their use in certain applications, such as in products that require an aesthetic appearance or bright colors. There are also cases where intrinsically conductive polymers are added to polymers to achieve ESD electrostatic protection. However, these intrinsically conductive polymers have insufficient heat resistance and are prone to hydrolysis reactions, especially in hot and humid summers, resulting in insufficient durability of the plastics. At the same time, due to the insufficient electrical conductivity of these intrinsically conductive polymers themselves, it is very difficult to control the surface resistivity within 1E9 ohms / sq, unable to meet the requirements for the transportation and packaging of microelectronic products. Technicians sometimes also consider adding metal fibers to polymers to produce light-colored conductive products, but such products are either non-conductive or have very good conductivity and cannot control the surface resistivity between 1E5 - 1E9 ohms / sq;

[0004] Based on the above content, it can be seen that existing electrostatic protection plastics are either black in color, which becomes an important problem in some applications, such as carbon black, carbon fiber, graphite, carbon nanotubes, etc.; or they can be dyed bright colors to meet the market requirements for appearance, safety warning, and brand recognition, but there are problems of too high surface resistivity and poor durability; while there are also some electrostatic protection plastics that can meet the requirements of color and durability, but they are too conductive themselves and cannot meet the surface resistivity required by the microelectronics industry.

[0005] Therefore, it is necessary to propose a preparation method of a light-colored ESD electrostatic protection material to solve the above problems. Summary of the Invention

[0006] The main object of the present invention is to provide a preparation method of a light-colored ESD electrostatic protection material, which can effectively solve the problems in the background art.

[0007] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0008] A preparation method of a light-colored ESD electrostatic protection material, comprising the following operating steps:

[0009] S1: Prepare raw materials, including a polymer matrix, a conductive filler, a toughening agent, and an auxiliary agent, wherein by mass percentage, it includes 40-70 wt% of the polymer matrix, 30-60 wt% of the conductive filler, 2-5 wt% of the toughening agent, and 0.5-3 wt% of the auxiliary agent;

[0010] S2: Pretreatment, prepare the conductive filler and the auxiliary agent by mass percentage, and perform high-speed mixing and modification on the conductive filler and the auxiliary agent at 80-120 °C;

[0011] S3: Blending treatment, after premixing the conductive filler, polymer matrix, toughening agent, and color powder of the required color obtained by modifying in S2, perform melt blending through a twin-screw extruder, wherein the temperature of the twin-screw extruder is 220-380 °C, the screw speed is 200-400 revolutions per minute, and after the twin-screw extruder finishes melt blending, perform pelletizing treatment, wherein the length-diameter ratio of the twin-screw is ≥40:1;

[0012] S4: Injection molding, dry the pellets obtained by treating in S3 and then perform injection molding to obtain the light-colored ESD electrostatic protection material.

[0013] Preferably, the polymer matrix is selected from one or a combination of polybutylene terephthalate, polycarbonate / polybutylene terephthalate alloy, and polyether ether ketone.

[0014] Preferably, the conductive filler is one of mica powder coated with ATO and titanium dioxide.

[0015] Preferably, the particle size of the conductive filler is 0.1-15 μm, and the resistivity <50 Ω·cm.

[0016] Preferably, the toughening agent is ethylene-acrylate copolymer.

[0017] Preferably, the auxiliary agent includes antioxidant 1010, lubricant ethylene bisstearamide, and silane coupling agent.

[0018] Preferably, by mass percentage, it includes 50 wt% of the polymer matrix, 45 wt% of the conductive filler, 4.5 wt% of the toughening agent, and 0.5% of the auxiliary agent;

[0019] The polymer matrix is polycarbonate / polybutylene terephthalate alloy, the conductive filler is titanium dioxide coated with ATO, the particle size is 0.1-1 μm, the toughening agent is ethylene-acrylate copolymer, and 0.5 wt% of the auxiliary agent includes 0.3 wt% of antioxidant and 0.2 wt% of silane coupling agent.

[0020] Preferably, it comprises 46 wt% of polymer matrix, 50 wt% of conductive filler, 3 wt% of toughening agent and 0.5% of auxiliary agent by mass percentage;

[0021] The polymer matrix is polyetheretherketone, the conductive filler is mica powder coated with ATO, with a particle size of 5 - 15 μm, the toughening agent is ethylene-acrylate copolymer, and the auxiliary agent is lubricant ethylene bisstearamide.

[0022] Preferably, the surface resistivity of the light-colored ESD electrostatic protection material is 1E5 - 1E9 Ω / sq, and the color can be adjusted to white or light colors with a brightness value > 80.

[0023] Compared with the prior art, the present invention provides a preparation method of a light-colored ESD electrostatic protection material, having the following beneficial effects:

[0024] 1. The preparation method of the light-colored ESD electrostatic protection material mainly solves the following technical problems:

[0025] 1) Color limitation problem: Existing electrostatic protection plastics mainly add carbon-based conductive fillers, which have great limitations in color, usually black or dark gray, restricting their use in some application scenarios. For example, in products that require an aesthetic appearance or bright colors, the present invention uses mica coated with ATO or titanium dioxide coated with ATO. Since their colors are lighter, such plastics can be dyed into different colors, expanding the application range;

[0026] 2) Balance problem between conductive performance and other properties: Existing intrinsic conductive polymers, although they can provide certain electrostatic protection performance, have insufficient durability and cannot continuously provide the required mechanical strength, resulting in a decrease in product life, nor can they provide a wide range of surface resistivities to meet the more stringent electrostatic protection requirements of the microelectronics industry. The present invention realizes the balance between conductive performance and other properties by adding mica powder coated with ATO or titanium dioxide coated with ATO to plastics;

[0027] 3) Complex plastic preparation process problem: The existing electrostatic protection plastic preparation process is complex, usually requiring complex mechanical mixing, melt dispersion, and strict melt temperature control and other steps to achieve good dispersion and moderate electrical properties. The present invention can simplify the plastic preparation process, improve production efficiency and the yield rate by adding mica powder coated with ATO or titanium dioxide coated with ATO.

[0028] 2. The preparation method of the light-colored ESD electrostatic protection material only uses ATO-coated conductive mica / titanium dioxide to solve the color limitation problem, and the resistivity is precisely adjusted to 1E5 - 1E9 Ω / sq, meeting the ESD protection requirements of the microelectronics industry. Through the pretreatment with a coupling agent and the segmented screw shearing process, uniform dispersion of the filler is achieved under 60wt% high filling, avoiding performance fluctuations caused by agglomeration. Polycarbonate / polybutylene terephthalate alloy or polyether ether ketone is used to balance heat resistance (heat distortion temperature > 150°C) and processing fluidity, and is suitable for precision injection molding.

[0029] 3. The preparation method of the light-colored ESD electrostatic protection material. The material prepared by the present invention only uses inorganic conductive fillers with ATO coating to solve the color limitation problem. The resistivity is precisely adjusted to 1E5 - 1E9 Ω / sq, meeting the stringent electrostatic protection requirements of the microelectronics industry. Through the pretreatment with a silane coupling agent and the segmented screw shearing process, uniform dispersion of the filler is achieved under high filling, and performance fluctuations caused by agglomeration can be avoided. Polybutylene terephthalate, polycarbonate / polybutylene terephthalate alloy, and polyether ether ketone are used to balance heat resistance and processing fluidity, and are suitable for precision injection molding. Moreover, by simplifying the formula with a single conductive filler system, the yield can be effectively improved. Detailed implementation manners

[0030] To make the technical means, creative features, achieved purposes and effects of the present invention easy to understand, the present invention will be further described below in conjunction with specific implementation manners.

[0031] A preparation method of a light-colored ESD electrostatic protection material includes the following operation steps:

[0032] S1: Prepare raw materials, including a polymer matrix, a conductive filler, a toughening agent, and an auxiliary agent. Among them, by mass percentage, it includes 40 - 70wt% of the polymer matrix, 30 - 60wt% of the conductive filler, 2 - 5wt% of the toughening agent, and 0.5 - 3wt% of the auxiliary agent. The polymer matrix is selected from one or a combination of polybutylene terephthalate, polycarbonate / polybutylene terephthalate alloy, and polyether ether ketone; the conductive filler is one of mica powder and titanium dioxide with ATO coating, the particle size of the conductive filler is 0.1 - 15 μm, and the resistivity < 50 Ω·cm; the toughening agent is ethylene-acrylate copolymer; the auxiliary agent includes antioxidant 1010, lubricant ethylene bisstearamide, and silane coupling agent;

[0033] S2: Pretreatment. Prepare the conductive filler and the auxiliary agent by mass percentage, and perform high-speed mixing and modification of the conductive filler and the auxiliary agent at 80 - 120°C;

[0034] S3: Blending treatment. After premixing the modified conductive filler, polymer matrix, toughening agent, and color powder of the required color obtained in S2, melt blending is carried out through a twin-screw extruder. The temperature of the twin-screw extruder is 220 - 380 °C, the screw speed is 200 - 400 revolutions per minute. After the twin-screw extruder finishes melt blending, pelletizing treatment is carried out, where the ratio of the screw length to the diameter of the twin-screw is ≥ 40:1;

[0035] S4: Injection molding. After drying the pellets treated in S3, injection molding is carried out to obtain a light-colored ESD electrostatic protection material. The surface resistivity of the light-colored ESD electrostatic protection material is 1E5 - 1E9 Ω / sq, and the color can be adjusted to white or light colors with a brightness value > 80.

[0036] Example 1:

[0037] A preparation method of a light-colored ESD electrostatic protection material, comprising the following operating steps:

[0038] S1: Prepare raw materials, including polymer matrix, conductive filler, toughening agent, and additives. By mass percentage, it includes 50 wt% of polymer matrix, 45 wt% of conductive filler, 4.5 wt% of toughening agent, and 0.5% of additives;

[0039] The polymer matrix is a polycarbonate / polybutylene terephthalate alloy, the conductive filler is titanium dioxide coated with ATO, with a particle size of 0.1 - 1 μm, the toughening agent is an ethylene-acrylate copolymer, and 0.5 wt% of the additives include 0.3 wt% of antioxidant and 0.2 wt% of silane coupling agent;

[0040] S2: Pretreatment. Prepare the conductive filler and additives by mass percentage, and carry out high-speed mixing modification of the conductive filler and silane coupling agent at 80 - 120 °C;

[0041] S3: Blending treatment. After premixing the modified conductive filler, polymer matrix, toughening agent, and color powder of the required color obtained in S2, melt blending is carried out through a twin-screw extruder. The temperature of the twin-screw extruder is 220 - 380 °C, the screw speed is 200 - 400 revolutions per minute. After the twin-screw extruder finishes melt blending, pelletizing treatment is carried out, where the ratio of the screw length to the diameter of the twin-screw is ≥ 40:1;

[0042] S4: Injection molding. After drying the pellets treated in S3, injection molding is carried out to obtain a light-colored ESD electrostatic protection material. The surface resistivity of the light-colored ESD electrostatic protection material is 1E5 - 1E9 Ω / sq, and the color can be adjusted to white or light colors with a brightness value > 80.

[0043] Example 2:

[0044] A preparation method of a light-colored ESD electrostatic protection material, comprising the following operating steps:

[0045] S1: Prepare raw materials, including a polymer matrix, conductive filler, toughening agent, and additives, which include 46 wt% polymer matrix, 50 wt% conductive filler, 3 wt% toughening agent, and 0.5% additives by mass percentage;

[0046] The polymer matrix is polyetheretherketone, the conductive filler is mica powder coated with ATO, with a particle size of 5 - 15 μm, the toughening agent is ethylene - acrylate copolymer, and the additive is lubricant ethylene bisstearamide;

[0047] S2: Pretreatment, prepare the conductive filler and additives by mass percentage, and conduct high - speed mixing and modification of the conductive filler and silane coupling agent at 80 - 120 °C;

[0048] S3: Blending treatment, premix the modified conductive filler, polymer matrix, toughening agent, and color powder of the required color after S2, and then conduct melt blending through a twin - screw extruder. The temperature of the twin - screw extruder is 220 - 380 °C, the screw speed is 200 - 400 revolutions per minute. After the twin - screw extruder finishes melt blending, pelletizing treatment is carried out, where the length - to - diameter ratio of the twin - screw is ≥40:1;

[0049] S4: Injection molding, dry the pellets after S3 treatment and then inject them to obtain a light - colored ESD electrostatic protection material. The surface resistivity of the light - colored ESD electrostatic protection material is 1E5 - 1E9 Ω / sq, and the color can be adjusted to white or light colors with a brightness value > 80.

[0050] Compare the properties of the materials prepared by the present invention with those prepared by the prior art. The materials of the present invention are denoted as Examples 1 - 2, and the materials of the prior art are denoted as Comparative Example 1. The materials of the prior art include 46 parts of polyetheretherketone, 54 parts of conductive titanium dioxide, and 2 parts of color powder. After the above steps, light - colored ESD plastic samples are prepared for testing. The following is the comparison table:

[0051]

[0052]

[0053] Based on this, it can be known that the materials prepared by the present invention have excellent properties.

[0054] The material prepared by the present invention only uses inorganic conductive fillers with ATO coating to solve the color limitation problem. The resistivity is accurately regulated to 1E5 - 1E9 Ω / sq, meeting the stringent electrostatic protection requirements of the microelectronics industry. Through the pretreatment with silane coupling agent and the segmented screw shearing process, the uniform dispersion of fillers under high filling is achieved, which can avoid the performance fluctuations caused by agglomeration. Using polybutylene terephthalate, polycarbonate / polybutylene terephthalate alloy, and polyether ether ketone can balance heat resistance and processing fluidity, and is suitable for precision injection molding. Moreover, by simplifying the formula with a single conductive filler system, the yield can be effectively improved.

[0055] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments. The above embodiments and the descriptions in the specification only illustrate the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed. The scope of the present invention claimed is defined by the appended claims and their equivalents.

Claims

1. A preparation method of a light-colored ESD electrostatic protection material, characterized in that: The following operating steps are included: S1: Prepare raw materials, including a polymer matrix, a conductive filler, a toughening agent, and additives, where the polymer matrix accounts for 40 - 70 wt% by mass percentage, the conductive filler accounts for 30 - 60 wt%, the toughening agent accounts for 2 - 5 wt%, and the additives account for 0.5 - 3 wt%; S2: Pretreatment, prepare the conductive filler and additives by mass percentage, and perform high-speed mixing and modification on the conductive filler and additives at 80 - 120 °C; S3: Blending treatment, premix the conductive filler modified in S2, the polymer matrix, the toughening agent, and color powder of the required color, and then perform melt blending through a twin-screw extruder. The temperature of the twin-screw extruder is 220 - 380 °C, the screw speed is 200 - 400 revolutions per minute. After the twin-screw extruder finishes melt blending, granulation treatment is carried out, where the length-diameter ratio of the twin-screw is ≥40:1; S4: Injection molding, dry the pellets treated in S3 and then perform injection molding to obtain a light-colored ESD electrostatic protection material.

2. The preparation method of a light-colored ESD electrostatic protection material according to claim 1, characterized in that: The polymer matrix is selected from one or a combination of polybutylene terephthalate, polycarbonate / polybutylene terephthalate alloy, and polyether ether ketone.

3. The preparation method of a light-colored ESD electrostatic protection material according to claim 1, characterized in that: The conductive filler is one of mica powder coated with ATO and titanium dioxide.

4. The preparation method of a light-colored ESD electrostatic protection material according to claim 3, characterized in that: The particle size of the conductive filler is 0.1 - 15 μm, and the resistivity < 50 Ω·cm.

5. The preparation method of a light-colored ESD electrostatic protection material according to claim 1, characterized in that: The toughening agent is ethylene-acrylate copolymer.

6. The preparation method of a light-colored ESD electrostatic protection material according to claim 1, characterized in that: The additives include antioxidant 1010, lubricant ethylene bisstearamide, and silane coupling agent.

7. The preparation method of a light-colored ESD electrostatic protection material according to claim 1, characterized in that: It includes 50 wt% of the polymer matrix, 45 wt% of the conductive filler, 4.5 wt% of the toughening agent, and 0.5% of the additives by mass percentage; The polymer matrix is polycarbonate / polybutylene terephthalate alloy, the conductive filler is titanium dioxide coated with ATO, the particle size is 0.1 - 1 μm, the toughening agent is ethylene-acrylate copolymer, and 0.5 wt% of the additives include 0.3 wt% of antioxidant and 0.2 wt% of silane coupling agent.

8. The preparation method of a light-colored ESD electrostatic protection material according to claim 1, characterized in that: It includes 46 wt% of the polymer matrix, 50 wt% of the conductive filler, 3 wt% of the toughening agent, and 0.5% of the additives by mass percentage; The polymer matrix is polyether ether ketone, the conductive filler is mica powder coated with ATO, the particle size is 5 - 15 μm, the toughening agent is ethylene-acrylate copolymer, and the additive is lubricant ethylene bisstearamide.

9. The preparation method of a light-colored ESD electrostatic protection material according to claim 1, characterized in that: The surface resistivity of the light-colored ESD electrostatic protection material is 1E5 - 1E9 Ω / sq, and the color can be adjusted to white or light colors with a brightness value > 80.

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