CN103642068B - Antistatic slurry - Google Patents

Abstract

The invention discloses an antistatic slurry, which contains a conductive filler and a silane coupling agent. The conductive filler is composed of conductive powder A and conductive powder B at a weight ratio of 1:2-10, and the conductive powder A is carbon Black and/or graphite, the particle size is 800-2000nm, the conductive powder B is carbon black with a particle size of 20-200nm; the weight percentage of the conductive filler in the slurry is 0.5-5%, and the silane coupling agent is relatively The weight percentage of the conductive filler is 0.03-3%. The antistatic slurry of the invention has good dispersibility and small resistance variation range. Compared with other pastes with the same content of nano-scale (or micron-scale) carbon black or graphite as conductive fillers, when applied to antistatic polyimide film, the mechanical properties of the film can be increased by 20-30%. ; or in the preparation of polyimide films with the same mechanical properties, the conductive filler content in the slurry can be added by 5-10%.

Description

An antistatic slurry

technical field

The invention relates to an antistatic polyimide film, in particular to an antistatic slurry used in making the antistatic polyimide film.

Background technique

Antistatic polymer composite materials have the characteristics of antistatic, electromagnetic shielding, chemical corrosion resistance, light and soft body, and various sealing methods, so as to meet the needs of chemical products, microelectronic devices and other fields that have special requirements for packaging materials.

According to the difference in surface resistivity, materials can be divided into three categories: conductive, antistatic and insulating.

Polyimide (Polyimide, referred to as PI) film refers to a class of polymers containing imide rings in the main chain. It not only has good high and low temperature resistance, but also has good physical properties, electrical properties and mechanical properties. performance. Polyimide can maintain stable physical properties in a wide temperature range, and can withstand ambient temperatures from -269 to 400 °C. In addition, an antistatic polyimide film can be obtained by selecting suitable fillers and adopting a suitable film-forming technology. The filler particles can form a conductive network in the polyimide film matrix, which reduces the surface resistivity of the polymer. The accumulation of static electricity is prevented.

Since the 1960s, people have conducted extensive research on how to improve the antistatic properties of polymer materials, and formed four typical composite modification methods, namely: (1) adding conductive fillers; (2) adding Antistatic agent; (3) mixed with structural conductive polymer yellow; (4) surface coating.

In the modification method of adding conductive fillers, commonly used conductive fillers can be divided into two types: carbon-based and metal-based, and carbon-based conductive materials usually use conductive graphite or conductive carbon black. For example, the invention patent with the publication number CN102516574A discloses a preparation method of a three-layer antistatic polyimide film, which is prepared by adding nano-scale conductive graphite, conductive carbon black, Antimony-doped tin dioxide or fluorine-doped tin dioxide to achieve the purpose of modification. In addition, the invention patent with the publication number CN102120826A discloses a method for preparing an antistatic polyimide film. In this method, conductive fillers are added to an aprotic polar organic solvent, a silane coupling agent is added, and the temperature is controlled by ultrasonic stirring. , the conductive filler is evenly dispersed in the organic solution to make a stable and uniform conductive suspension, the conductive filler is micron-sized conductive graphite or micron-sized conductive carbon black, wherein the mass ratio of the conductive filler to the aprotic polar solvent is 0.005-0.25; the mass ratio of silane coupling agent to conductive filler is 0.02-0.1. The above-mentioned patents all use conductive graphite or conductive carbon black in a single particle size range as the conductive filler. Although the antistatic polyimide film obtained has certain antistatic properties, the mechanical properties of the obtained film are not ideal.

Contents of the invention

The technical problem to be solved by the invention is to provide an antistatic slurry with good dispersibility and stability. Compared with the antistatic polyimide film prepared by mixing the antistatic slurry with the polyamic acid resin solution in the prior art, the mechanical properties of the film can be improved. 20-30%.

An antistatic slurry, containing a conductive filler and a silane coupling agent, the conductive filler is composed of conductive powder A and conductive powder B in a weight ratio of 1:2 to 10, and the conductive powder A is carbon black and/or or graphite, the particle size of which is 800-2000nm, the conductive powder B is carbon black with a particle size of 20-200nm; the weight percentage of the conductive filler in the slurry is 0.5-5%, and the silane coupling agent is relative to The weight percentage of the conductive filler is 0.03-3%. In the present invention, conductive fillers with different particle sizes are selected for specific proportioning. After high-speed shearing, the obtained solution can effectively disperse the easily agglomerated carbon black particles, so as to obtain an antistatic slurry with good stability and small resistance variation range. The slurry is especially suitable for preparing antistatic resin materials.

In the above-mentioned technical scheme, it also includes conventional components used in making antistatic slurry, such as solvent, the choice of solvent is the same as the existing conventional technology, specifically, the solvent is preferably N-methylpyrrolidone, dimethylacetamide, Dimethylformamide or gamma-butyrolactone.

In the above technical solution, when the choice of conductive powder A is a combination of carbon black and graphite, the ratio between them can be any ratio.

In the above technical solution, when the particle size of the conductive powder A is selected to be 800-1200 nm, and the particle size of the conductive powder B is selected to be 30-50 nm, an antistatic slurry with better conductivity and stability can be obtained.

In the above technical solution, the weight ratio of the conductive powder A to the conductive powder B is preferably 1:3-5.

In the above technical solution, the weight percentage of the conductive filler in the slurry is preferably 0.9-5%.

In the above technical scheme, the silane coupling agent can be a conventional choice in the prior art, specifically, it can be selected from γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyl Methyldiethoxysilane, N-(2-aminoethyl-3-aminopropyl)methyldimethoxysilane, n-octyltriethoxysilane, γ-aminopropyltriethoxy Silane, N-β(aminoethyl)γ-aminopropyltrimethoxysilane, N-β(aminoethyl)γ-aminopropylmethyldimethoxysilane and sodium dodecylbenzenesulfonate one or a combination of two or more. When the silane coupling agent is selected as a combination of any two or more of the above, the ratio between them can be any ratio.

The antistatic slurry of the present invention can be prepared by existing conventional methods, specifically as follows: add a formulated amount of silane coupling agent to the formulated amount of solvent, stir for 10 to 30 minutes and then add the formulated amount Conductive filler, then pre-dispersed by ultrasonic for 10-60 minutes, and then homogenized under high pressure to obtain corona-resistant slurry. Wherein, the pre-dispersion time is preferably 20-40 minutes, and the homogenization is usually performed in a high-pressure homogenizer, and the homogenization time is usually 3-8 minutes.

Compared with the prior art, the present invention selects conductive fillers of different particle sizes for specific proportioning, and after high-speed shearing of the obtained solution, the easily agglomerated carbon black particles are effectively dispersed to obtain good dispersibility, The range of resistance change is small, and it is suitable for preparing antistatic slurry of antistatic resin materials. Compared with other pastes with the same content of nano-scale (or micron-scale) carbon black or graphite as conductive fillers, when applied to antistatic polyimide film, the mechanical properties of the film can be increased by 20-30%. ; or in the preparation of polyimide films with the same mechanical properties, the conductive filler content in the slurry can be added by 5-10%.

Detailed ways

The present invention will be further described below with specific examples, but the present invention is not limited to these examples.

Example 1

Weigh 1000g of N,N-dimethylacetamide as a solvent, add 0.36g of γ-aminopropyltriethoxysilane, stir for 15min, then add conductive powder A (2g of carbon black with a particle size of 1000-2000nm ) and conductive powder B (10 g of carbon black with a particle size of 30 nm), ultrasonically pre-dispersed for 30 min, and then homogenized with a high-pressure homogenizer for 5 min to obtain a stably dispersed antistatic slurry.

Comparative example 1-1

Weigh 1000g of N,N-dimethylacetamide as a solvent, add 0.36g of γ-aminopropyltriethoxysilane, stir for 15min, then add conductive powder A (2g of carbon black with a particle size of 2000-2500nm ) and conductive powder B (10 g of carbon black with a particle size of 200-250 nm), ultrasonically pre-dispersed for 30 minutes, and then homogenized with a high-pressure homogenizer for 5 minutes to obtain an antistatic slurry.

Comparative example 1-2

Weigh 1000g of N,N-dimethylacetamide as a solvent, add 0.36g of γ-aminopropyltriethoxysilane, stir for 15min, then add conductive powder A (6g of carbon black with a particle size of 1000-2000nm ) and conductive powder B (6g of carbon black with a particle size of 30nm), ultrasonically pre-dispersed for 30min, and then homogenized for 5min with a high-pressure homogenizer to obtain an antistatic slurry.

Example 2

Weigh 1000g of N,N-dimethylacetamide as a solvent, add 0.2g of sodium dodecylbenzenesulfonate, stir for 15min, then add conductive powder A (1.5g of graphite with a particle size of 1000nm) and conductive powder B (7.5 g of carbon black with a particle size of 30 nm), pre-dispersed by ultrasonic for 20 minutes, and then homogenized by a high-pressure homogenizer for 5 minutes to obtain a stably dispersed antistatic slurry.

Example 3

Weigh 1000g of N,N-dimethylacetamide as a solvent, add 0.075g of sodium dodecylbenzenesulfonate, stir for 10min, then add conductive powder A (1.5g of graphite with a particle size of 1000-2000nm) and Conductive powder B (6.0 g of carbon black with a particle size of 30 nm) was pre-dispersed by ultrasonic for 40 minutes, and then homogenized by a high-pressure homogenizer for 5 minutes to obtain a stably dispersed antistatic slurry.

Example 4

Weigh 1000g of N,N-dimethylacetamide as a solvent, add 0.3g of sodium dodecylbenzenesulfonate, stir for 15min, then add conductive powder A (2.4g of graphite with a particle size of 1000nm) and conductive powder B (9.6 g of carbon black with a particle size of 30 nm), pre-dispersed by ultrasonic for 20 minutes, and then homogenized by a high-pressure homogenizer for 10 minutes to obtain a stably dispersed antistatic slurry.

Comparative example 4-1

Weigh 1000g of N,N-dimethylacetamide as a solvent, add 0.5g of γ-aminopropyltriethoxysilane, stir for 15min, add 12g of carbon black with a particle size of 30nm, ultrasonically pre-disperse for 30min, and then Homogenize for 5 minutes with a high-pressure homogenizer to obtain an antistatic slurry.

Comparative example 4-2

Weigh 1000g of N,N-dimethylacetamide as a solvent, add 0.5g of γ-aminopropyltriethoxysilane, stir for 15min, add 12g of carbon black with a particle size of 1000-2000nm, and ultrasonically pre-disperse for 30min , and then use a high-pressure homogenizer to homogenize for 5 minutes to obtain an antistatic slurry.

Comparative example 4-3

Weigh 1000g of N,N-dimethylacetamide as a solvent, add 0.3g of sodium dodecylbenzenesulfonate, stir for 15min, then add conductive powder A (2.4g of graphite with a particle size of 500nm) and conductive powder B (9.6 g of carbon black with a particle size of 30 nm), ultrasonically pre-dispersed for 20 minutes, and then homogenized with a high-pressure homogenizer for 10 minutes to obtain an antistatic slurry.

Example 5

Weigh 1000g of N,N-dimethylacetamide as a solvent, add 0.3g of sodium dodecylbenzenesulfonate, stir for 20min, then add conductive powder A (0.6g of carbon black with a particle size of 800-1000nm, 0.9g of graphite with a particle size of 1000-1200nm) and conductive powder B (14.5g of carbon black with a particle size of 50-80nm), ultrasonically pre-dispersed for 20 minutes, and then homogenized with a high-pressure homogenizer for 5 minutes to obtain a stable dispersed antistatic slurry .

Example 6

Weigh 1000g of N,N-dimethylacetamide as a solvent, add 0.25g of sodium dodecylbenzenesulfonate, stir for 10min, then add conductive powder A (3g of carbon black with a particle size of 1500-2000nm) and Conductive powder B (6g of carbon black with a particle size of 100-200nm), ultrasonically pre-dispersed for 20 minutes, and then homogenized with a high-pressure homogenizer for 5 minutes to obtain a stably dispersed antistatic slurry.

Preparation of film sample 1:

Add 4,4'-aminodiphenyl ether of 86.16g in the antistatic slurry that embodiment 1 makes, after dissolving, then add pyromellitic dianhydride to adjust viscosity, make the viscosity of final gained polyamic acid solution be 60,000 centipoise, after the vacuum defoaming is completed, the film is made by drooling, stretching and imidization according to the conventional process. The obtained film sample 1 has a thickness of 25 microns, and the conductive filler accounts for 6.25% by weight of the entire film. The surface resistivity and mechanical properties are measured, and the data are shown in Table 1 below.

Preparation of Comparative Film Sample 1:

The method for preparing film sample 1 was repeated, except that the antistatic slurry prepared in Comparative Example 1-1 was used instead of the antistatic slurry prepared in Example 1. The obtained comparative film sample 1 has a thickness of 25 microns, and the conductive filler accounts for 6.25% by weight of the entire film. The surface resistivity and mechanical properties are measured, and the data are shown in Table 1 below.

Preparation of Comparative Film Sample 2:

The method for preparing film sample 1 was repeated, except that the antistatic slurry prepared in Comparative Example 1-2 was used instead of the antistatic slurry prepared in Example 1. The obtained comparative film sample 1 has a thickness of 25 microns, and the conductive filler accounts for 6.25% by weight of the entire film. The surface resistivity and mechanical properties are measured, and the data are shown in Table 1 below.

Preparation of film sample 2

Add 81.84g of 4,4'-aminodiphenyl ether to the corona-resistant slurry prepared in Example 2. After the dissolution, add pyromellitic dianhydride to adjust the viscosity, so that the viscosity of the final polyamic acid solution is 5.6 10,000 centipoise, after the vacuum defoaming is completed, the film is made by drooling, stretching and imidization according to the conventional process. The obtained film sample 2 has a thickness of 25 microns, wherein the conductive filler accounts for 5% by weight of the entire film, and its surface resistivity and mechanical properties are measured, and the data are shown in Table 1 below.

Preparation of film sample 3:

Add 86.16g of 4,4'-aminodiphenyl ether to the corona-resistant slurry prepared in Example 3. After dissolving, add pyromellitic dianhydride to adjust the viscosity, so that the viscosity of the finally gained polyamic acid solution is 5.2 10,000 centipoise, after the vacuum defoaming is completed, the film is made by drooling, stretching and imidization according to the conventional process. The obtained film sample 3 has a thickness of 25 microns, wherein the conductive filler accounts for 4% by weight of the entire film, and its surface resistivity and mechanical properties are measured, and the data are shown in Table 1 below.

Preparation of film sample 4:

Add 89.98g 4,4'-aminodiphenyl ether to the corona-resistant slurry prepared in Example 4. After the dissolution, add pyromellitic dianhydride to adjust the viscosity, so that the viscosity of the final polyamic acid solution is 5.5 10,000 centipoise, after the vacuum defoaming is completed, the film is made by drooling, stretching and imidization according to the conventional process. The obtained film sample 4 has a thickness of 25 microns, and the conductive filler accounts for 6% by weight of the entire film. The surface resistivity and mechanical properties are measured, and the data are shown in Table 1 below.

Preparation of Comparative Film Sample 3:

The method for preparing film sample 4 was repeated, except that the antistatic slurry prepared in Example 4 was replaced by the antistatic slurry prepared in Comparative Example 4-1. The obtained comparative film sample 3 had a thickness of 25 microns, and the conductive filler accounted for 6% by weight of the entire film. The surface resistivity and mechanical properties were measured, and the data are shown in Table 1 below.

Preparation of Comparative Film Sample 4:

The method for preparing film sample 1 was repeated, except that the antistatic slurry prepared in Comparative Example 4-2 was used instead of the antistatic slurry prepared in Example 1. The obtained comparative film sample 4 had a thickness of 25 microns, and the conductive filler accounted for 6% by weight of the entire film. The surface resistivity and mechanical properties were measured, and the data are shown in Table 1 below.

Preparation of comparative film sample 5:

The method for preparing film sample 1 was repeated, except that the antistatic slurry prepared in Comparative Example 4-3 was used instead of the antistatic slurry prepared in Example 1. The obtained comparative film sample 5 has a thickness of 25 microns, wherein the conductive filler accounts for 6% by weight of the entire film, and its surface resistivity and mechanical properties are measured, and the data are shown in Table 1 below.

Preparation of film sample 5:

Add 88.07g of 4,4'-aminodiphenyl ether to the corona-resistant slurry prepared in Example 5. After dissolving, add pyromellitic dianhydride to adjust the viscosity, so that the viscosity of the final polyamic acid solution is 4.8 10,000 centipoise, after the vacuum defoaming is completed, the film is made by drooling, stretching and imidization according to the conventional process. The obtained film sample 5 has a thickness of 20 microns, wherein the conductive filler accounts for 8% by weight of the entire film, and its surface resistivity and mechanical properties are measured, and the data are shown in Table 1 below.

Preparation of film sample 6:

Add 90.93g of 4,4'-aminodiphenyl ether to the corona-resistant slurry prepared in Example 6. After dissolving, add pyromellitic dianhydride to adjust the viscosity, so that the viscosity of the finally gained polyamic acid solution is 5.5 10,000 centipoise, after the vacuum defoaming is completed, the film is made by drooling, stretching and imidization according to the conventional process. The obtained film sample 6 has a thickness of 20 microns, wherein the conductive filler accounts for 5% by weight of the entire film, and its surface resistivity and mechanical properties are measured, and the data are shown in Table 1 below.

Table 1:

As can be seen from Table 1, the antistatic slurry obtained by selecting conductive fillers with different particle sizes in a specific proportion in the present invention has good dispersibility and a small range of resistance change, which is different from other carbons with the same content of nano-scale (or micron-scale) alone. Compared with the slurry of black or graphite as conductive filler, when applied to antistatic polyimide film, the mechanical properties of the film can be improved by 20-30%; or in the preparation of polyimide film with the same mechanical properties, the slurry The content of conductive filler in the material can be added by 5-10%.

Claims (6)

1. An antistatic slurry containing conductive filler and silane coupling agent, characterized in that: the conductive filler is composed of conductive powder A and conductive powder B in a weight ratio of 1:2 to 10, and the conductive powder A It is carbon black and/or graphite with a particle size of 800-2000nm, and the conductive powder B is carbon black with a particle size of 20-200nm; the weight percentage of the conductive filler in the slurry is 0.5-5%, and the silane The weight percentage of the coupling agent relative to the conductive filler is 0.03-3%. 2. The antistatic slurry according to claim 1, characterized in that: the particle size of the conductive powder A is 800-1200 nm. 3. The antistatic slurry according to claim 1, characterized in that: the particle size of the conductive powder B is 30-50 nm. 4. The antistatic slurry according to claim 1, characterized in that: the weight ratio of the conductive powder A to the conductive powder B is 1:3-5. 5. The antistatic slurry according to any one of claims 1-4, characterized in that: the weight percentage of the conductive filler in the slurry is 0.9-5%. 6. The antistatic slurry according to any one of claims 1 to 4, characterized in that: the silane coupling agent is selected from γ-glycidoxypropyltrimethoxysilane, γ- Glycidoxypropylmethyldiethoxysilane, N-(2-aminoethyl-3-aminopropyl)methyldimethoxysilane, n-octyltriethoxysilane, γ- Aminopropyltriethoxysilane, N-β(aminoethyl)γ-aminopropyltrimethoxysilane, N-β(aminoethyl)γ-aminopropylmethyldimethoxysilane and dodeca One or more combinations of sodium alkylbenzene sulfonates.