CN105037766A - Preparation method of SiO2 hollow sphere/graphene oxide/polyimide composite film - Google Patents

Abstract

The invention relates to a SiO₂ Hollow ball/Graphene oxide/A method for preparing a polyimide composite film. The base material of the prior copper clad laminate adopts a copper clad polyimide film PI, PI The electric insulation, high temperature resistance, fire resistance that have, along with electronic information product is to high-speed development of high frequency, integrated circuit signal resistance capacity delay, crosstalk and energy consumption problem also are highlighted gradually, and the signal transmission characteristic of printing board receives the influence of printing board substrate dielectric constant and dielectric loss very big, in order to satisfy the high-speed of signal transmission, improves the electronic circuit function, need urgently to develop novel low dielectric constant material and solve above-mentioned problem. The invention comprises the following steps: preparation of the core by template method - Shell "structure of microspheres in 650 Sintering at a temperature of 3h To prepare the nano silicon dioxide hollowHeart ball and by improvement Hummers Preparing the graphene oxide nanosheet by using a method. The invention is used for SiO₂ Hollow ball/Graphene oxide/A method for preparing a polyimide composite film.

Description

Preparation method of SiO2 hollow sphere/graphene oxide/polyimide composite film

Technical field:

The invention relates to the technical field of insulating materials, in particular to a SiO ₂ Preparation method of hollow sphere/graphene oxide/polyimide composite film.

Background technique:

At present, the base material of copper clad board mainly adopts copper clad polyimide film. Polyimide has excellent electrical insulation properties, mechanical properties, high temperature resistance, flame retardancy and weather resistance, etc. With the development of high-frequency and high-speed information products, the problems of signal capacitive delay, crosstalk and energy consumption in integrated circuits have become increasingly prominent, and the signal transmission characteristics of printed boards are affected by the dielectric constant and dielectric loss of printed board substrates. In order to meet the high speed of signal transmission and further improve the function of electronic circuits, it is urgent to develop new low dielectric constant materials to solve the above problems, so the preparation of nanometer materials with low dielectric constant, high heat resistance and good comprehensive performance SiO ₂ Hollow sphere/graphene oxide/polyimide composites are of great significance.

As the size of large-scale integrated circuits shrinks to the sub-micron level and the complexity of circuits and the speed of signal transmission increase, the density of wires in chips continues to increase, and the width and spacing of wires continue to decrease. The parasitic effect is becoming more and more obvious. In order to reduce the signal delay and crosstalk caused by the resistance and capacitance delay of nanoscale microelectronic devices, polyimide materials with lower dielectric constants are required. Therefore, researchers set out to modify polyimide. One of the more effective methods is to introduce inorganic nanoparticles into the polyimide matrix. The specific surface area of inorganic nanoparticles is large, and the functional groups contained on the surface More, can form a new chemical bond structure with the polyimide matrix material, this structure is conducive to endowing polyimide with better dielectric properties and mechanical properties, etc., as the inorganic nanoparticles of polyimide modifier At present, there are more nanoparticles such as silica and alumina, and polyimide/silica nanocomposites prepared by sol-gel method. When the silica content is within a certain range, the hybrid The mechanical and thermal properties of the material are significantly improved. The nano-alumina dispersion is prepared by the hydrothermal method, and then the polyimide/alumina nanocomposite material is prepared, and its breakdown strength and corona resistance have been significantly improved. , the above aspects only study the unilateral performance of polyimide by inorganic nanoparticles, and rarely involve the comprehensive performance of polyimide three-phase composite materials such as electrical properties, thermal properties and mechanical properties.

Invention content:

The object of the invention is to provide a SiO ₂ Preparation method of hollow sphere/graphene oxide/polyimide composite film.

Above-mentioned purpose realizes by following technical scheme:

A SiO ₂ A method for preparing a hollow sphere/graphene oxide/polyimide composite film, the method includes the following steps: using a template method to prepare "core-shell" structure microspheres, and sintering at 650°C for 3 hours to prepare nano-dioxide Silicon hollow spheres, and the preparation of graphene oxide nanosheets by the improved Hummers method;

(1) At room temperature, add 0.60g of polyacrylic acid and 9mL of ammonia water into a 250mL three-necked flask, oscillate and mix evenly, then quickly add 180mL of absolute ethanol, stir in an ultrasonic instrument, and add 4.5mL of normal Ethyl silicate, after the reaction, a white emulsion is obtained, dried, ground, and calcined at 650°C to obtain white nano-silica hollow spheres;

(2) Add 75mL concentrated sulfuric acid and 25mL concentrated nitric acid mixed solution in the there-necked flask, then add 2g expanded graphite, slowly add 12g potassium permanganate in six times, react for 1 hour, the whole process is carried out under the ice-water bath environment, Move the three-necked bottle to a constant temperature water bath at 35°C and continue to react for 2 hours. During the reaction, add an appropriate amount of deionized water several times and raise the water bath to 98°C for 1 hour. At this time, the solution turns brown. After the reaction, , add an appropriate amount of hydrogen peroxide solution with a concentration of 30%, at this time the solution turns bright yellow, add a large amount of deionized water to dilute, filter the reactant, remove unreacted potassium permanganate in the mixture, and centrifuge the obtained liquid repeatedly , until the pH value is 7, drying and grinding the resulting mixture to obtain graphite oxide powder, adding the prepared graphite oxide powder into deionized water, ultrasonically oscillating for 3 hours and then drying to obtain graphene oxide nanosheets;

(3) Take the required inorganic content according to the performance requirements of the composite material, weigh the required amount of graphene oxide nanosheets, N,N'-dimethylacetamide and add them to the three-necked bottle, ultrasonically oscillate, mechanically stir and disperse, Add an appropriate amount of 4,4'-diaminodiphenyl ether, under the condition of nitrogen protection, reflux at 60°C for 12h, add nano-silica hollow spheres, stir ultrasonically for 1h, then add 4,4 ^' -Diaminodiphenyl ether, add an appropriate amount of pyromellitic dianhydride into the system in 6 times, when the ratio of the two reaches the equivalent, the viscosity of the system rises sharply, and the rod climbing phenomenon occurs, and the nano-silica hollow The ball/graphene oxide/polyamic acid solution continued to stir for 24 hours at room temperature;

(4) The prepared nano-silica hollow sphere-graphene oxide/polyamic acid solution is formed into a film on glass by an automatic film laying machine, placed in an oven, and the gradient temperature is raised for imidization, and the process of thermal imidization Temperature control: 80°C, 120°C, 150°C, 180°C, 200°C, 250°C, 300°C for 30 minutes each;

(5) Wait for natural cooling, put the glass plate with nano-silica hollow sphere-graphene oxide/polyimide composite film into deionized water to remove the film, put it into a drying box after drying and carry out dehydration treatment .

The SiO ₂ The preparation method of the hollow sphere/graphene oxide/polyimide composite film, the nano-silica hollow sphere is loaded in the graphene oxide, and the graphene oxide is treated with 4,4'-diaminodiphenyl ether, The two are connected by chemical bonds to further increase the layer spacing of graphene oxide micro-sheets, which is beneficial for the hollow silica spheres to enter between the graphene oxide sheets and further peel off, which not only facilitates the dispersion of graphene oxide, It is more conducive to the uniform distribution of the three-phase material in the composite process. This process needs to be under a protective atmosphere, either nitrogen protection or argon protection.

The SiO ₂ The preparation method of hollow sphere/graphene oxide/polyimide composite film, described nano-silica hollow sphere/graphene oxide/polyimide three-component composite helps to reduce the dielectric of polyimide constant and improve its mechanical properties.

The SiO ₂ The preparation method of hollow sphere/graphene oxide/polyimide composite film, in the described nano-silica hollow sphere/graphene oxide/polyimide three-component composite material, can be by adjusting silicon dioxide hollow sphere and The proportion of graphene oxide changes the polyimide composite properties.

Beneficial effect:

1. The present invention is mainly used in high-speed integrated circuit flexible copper-clad laminate substrates. The template method is used to prepare nano-silica microspheres, which are sintered at a high temperature of 650 ° C for 3 hours to obtain nano-silica hollow spheres. Graphene oxide nanosheets were prepared by the improved Hummer's method. According to the characterization results by transmission electron microscopy, the nano-silica hollow spheres are well dispersed without obvious agglomeration, and the surface is smooth, and the particle size is between 50-70nm.

2. The graphene oxide sheet layer prepared by the improved Hummers method of the present invention is relatively thin, and the texture is uniform, and the nano-SiO ₂ Hollow spheres are loaded onto graphene oxide nanosheets and filled into polyimide matrix to prepare a composite material with good dielectric properties, thermal properties and mechanical properties, which can be widely used as substrates for high-speed integrated circuit flexible copper clad laminates middle.

The present invention has the advantages that the nano-silica hollow spheres prepared by the template method have uniform particle size, smooth surface and high degree of dispersion; the graphene oxide sheet prepared by the improved Hummers method is thinner and has a uniform texture. ₂ Hollow spheres showed good dispersion in polyimide matrix after loading, and nano-SiO ₂ Hollow sphere/graphene oxide/polyimide composites have excellent dielectric properties, thermal stability and mechanical properties.

Nano hollow sphere of the present invention is as a kind of new nanostructure, and one of its obvious features is exactly to have very big interior space and the shell layer that thickness is in nanoscale scope, nano-SiO ₂ The unique hollow structure of the hollow sphere (the dielectric constant of air k≈1) greatly reduces the dielectric constant, and the nano-silica hollow sphere also has many excellent characteristics such as zero moisture absorption rate, excellent mechanical properties, and good thermal stability. , its composite material with polyimide can meet the requirements of new technologies in high-speed integrated circuits for substrate materials.

The graphene oxide of the present invention is a new type of carbon material with excellent performance. As an important derivative of graphene, the structure of graphene oxide and graphene is roughly the same, except that it extends infinitely in a two-dimensional space composed of a layer of carbon atoms. There are a large number of oxygen-containing groups connected to the basal surface, and the plane contains hydroxyl and epoxy groups, while the edge of its sheet contains carbonyl and carboxyl groups. These functional groups endow graphene oxide with some unique properties, such as easy water absorption and ability to absorb water. A stable micellar solution is formed in the aqueous solution system. Due to the large specific surface area of graphene oxide, the strength and adsorption performance of the composite material are enhanced after the addition, and it plays a very important role in improving the thermal, electrical, mechanical and other comprehensive properties of the material. .

In the present invention, the spherical aggregate formed by polyacrylic acid in ethanol solvent is used as a template, and tetraethyl orthosilicate is used as a silicon source, and nano-silica hollow spheres are prepared by sintering, and the nano-silica hollow spheres are combined with a silane coupling agent. The graphene oxide support prepared by the improved Hummer's method, the modified nano-SiO ₂ Hollow sphere/graphene oxide powder is combined with polyamic acid, and nano-SiO with good dielectric and thermal properties is prepared after heat treatment. ₂ Hollow sphere/graphene oxide/polyimide composite.

Description of drawings:

Accompanying drawing 1 is the graphene oxide powder X-ray diffraction spectrum that is prepared as raw material with expanded graphite of the present invention.

Accompanying drawing 2 is the X-ray diffraction pattern of the 4,4'-diaminodiphenyl ether-graphene oxide that method of the present invention obtains.

Accompanying drawing 3 is the X-ray diffraction spectrum of the nano-silica hollow sphere that the method of the present invention obtains.

Accompanying drawing 4 is the morphology (transmission electron microscope picture) of the graphene oxide that the method of the present invention obtains.

Accompanying drawing 5 is the morphology (transmission electron microscope image) of the 4,4'-diaminodiphenyl ether-graphene oxide obtained by the method of the present invention.

Accompanying drawing 6 is the morphology (transmission electron microscope picture) of the nano-silica hollow sphere obtained by the method of the present invention.

Accompanying drawing 7 is the morphology (transmission electron microscope image) of the nano-scale SHS-GO powder of nano-silica hollow spheres supported graphene oxide obtained by the method of the present invention.

Accompanying drawing 8 is the scan (scanning electron micrograph) of the cross-section of the nano-silica hollow sphere-graphene oxide/polyimide composite material obtained by the method of the present invention.

Detailed ways:

Example 1:

A method for preparing a SiO2 hollow sphere/graphene oxide/polyimide composite film, the method comprising the following steps: using a template method to prepare a "core-shell" structure microsphere, and sintering at 650°C for 3 hours to obtain Nano-silica hollow spheres, and graphene oxide nanosheets prepared by the improved Hummers method;

(1) At room temperature, add 0.60g of polyacrylic acid and 9mL of ammonia water into a 250mL three-necked flask, oscillate and mix evenly, then quickly add 180mL of absolute ethanol, stir in an ultrasonic instrument, and add 4.5mL of normal Ethyl silicate, after the reaction, a white emulsion is obtained, dried, ground, and calcined at 650°C to obtain white nano-silica hollow spheres;

(2) Add 75mL concentrated sulfuric acid and 25mL concentrated nitric acid mixed solution in the there-necked flask, then add 2g expanded graphite, slowly add 12g potassium permanganate in six times, react for 1 hour, the whole process is carried out under the ice-water bath environment, Move the three-necked bottle to a constant temperature water bath at 35°C and continue to react for 2 hours. During the reaction, add an appropriate amount of deionized water several times and raise the water bath to 98°C for 1 hour. At this time, the solution turns brown. After the reaction, , add an appropriate amount of hydrogen peroxide solution with a concentration of 30%, at this time the solution turns bright yellow, add a large amount of deionized water to dilute, filter the reactant, remove unreacted potassium permanganate in the mixture, and centrifuge the obtained liquid repeatedly , until the pH value is 7, drying and grinding the resulting mixture to obtain graphite oxide powder, adding the prepared graphite oxide powder into deionized water, ultrasonically oscillating for 3 hours and then drying to obtain graphene oxide nanosheets;

(3) Take the required inorganic content according to the performance requirements of the composite material, weigh the required amount of graphene oxide nanosheets, N,N'-dimethylacetamide and add them to the three-necked bottle, ultrasonically oscillate, mechanically stir and disperse, Add an appropriate amount of 4,4'-diaminodiphenyl ether, under the condition of nitrogen protection, reflux at 60°C for 12h, add nano-silica hollow spheres, stir ultrasonically for 1h, then add 4,4 ^' -Diaminodiphenyl ether, add an appropriate amount of pyromellitic dianhydride into the system in 6 times, when the ratio of the two reaches the equivalent, the viscosity of the system rises sharply, and the rod climbing phenomenon occurs, and the nano-silica hollow The ball/graphene oxide/polyamic acid solution continued to stir for 24 hours at room temperature;

(4) The prepared nano-silica hollow sphere-graphene oxide/polyamic acid solution is formed into a film on glass by an automatic film laying machine, placed in an oven, and the gradient temperature is raised for imidization, and the process of thermal imidization Temperature control: 80°C, 120°C, 150°C, 180°C, 200°C, 250°C, 300°C for 30 minutes each;

(5) Wait for natural cooling, put the glass plate with nano-silica hollow sphere-graphene oxide/polyimide composite film into deionized water to remove the film, put it into a drying box after drying and carry out dehydration treatment .

Example 2:

SiO described in embodiment 1 The preparation method of hollow sphere/graphene oxide/polyimide composite film, described hollow nano silicon dioxide sphere is loaded in graphene oxide, graphene oxide passes through 4,4 '- Diaminodiphenyl ether treatment, the two are linked by chemical bonds to further increase the interlayer spacing of the graphene oxide microsheets, which is conducive to the entry of the silicon dioxide hollow spheres between the graphene oxide sheets and further peeling off, which not only makes It is conducive to the dispersion of graphene oxide, and it is more conducive to the uniform distribution of three-phase materials in the composite process. This process needs to be under a protective atmosphere, either nitrogen protection or argon protection.

Example 3:

SiO described in embodiment 1 The preparation method of hollow sphere/graphene oxide/polyimide composite film, described nanometer silicon dioxide hollow sphere/graphene oxide/polyimide three-component composite helps to reduce Dielectric constant of polyimide and improve its mechanical properties.

Example 4:

SiO described in embodiment 1 The preparation method of hollow sphere/graphene oxide/polyimide composite film, can be passed in the described nanometer silicon dioxide hollow sphere/graphene oxide/polyimide three-component composite material Adjusting the ratio of silica hollow spheres to graphene oxide changes the properties of polyimide composites.

Claims (4)

1. a SiO ₂the method for making of hollow ball/graphene oxide/polyimide composite film, it is characterized in that: the method comprises the steps: to adopt template synthesis " core-shell structure copolymer " structure microspheres, 3h is sintered under the condition of 650 DEG C, obtained nano-silicon dioxide hollow sphere, and the Hummers legal system passing through to improve is for stannic oxide/graphene nano sheet;

(1) under room temperature, 0.60g polyacrylic acid and 9mL ammoniacal liquor is added in 250mL there-necked flask, concussion mixes, add rapidly 180mL dehydrated alcohol subsequently, be placed in ultrasonic instrument and stir, divide and in reaction system, add 4.5mL tetraethoxy 6 times, the emulsion of white is obtained after reaction terminates, drying, grinding, 650 DEG C of calcinings, obtain white nano-silicon dioxide hollow sphere;

(2) in there-necked flask, add the 75mL vitriol oil and 25mL concentrated nitric acid mixing solutions, then 2g expanded graphite is added, divide and slowly add 12g potassium permanganate six times, react 1 hour, whole process is all carry out under ice water bath environment, there-necked flask is moved in 35 DEG C of thermostat water baths and continue reaction 2 hours, add appropriate deionized water several times in reaction process and water-bath risen to 98 DEG C of reactions 1 hour, now solution becomes brown, after reaction terminates, add the superoxol that appropriate concentration is 30%, now solution becomes glassy yellow, add the dilution of a large amount of deionized water, filter reactant, remove unreacted potassium permanganate in mixture, by repeatedly centrifugal for the liquid obtained, until pH value is 7, the mixture of gained is dried and grinds, obtain graphite oxide powder, the graphite oxide powder prepared is added in deionized water, ultrasonic vibration 3 hours post-dryings, obtain stannic oxide/graphene nano sheet,

(3) get inorganic content needed for composite property requirement, take stannic oxide/graphene nano sheet, the N of desired number, N '-dimethyl ethanamide joins in there-necked flask; sonic oscillation, mechanical stirring is disperseed, and adds appropriate 4; 4 '-diaminodiphenyl oxide, under nitrogen protection condition, 60 DEG C; backflow 12h; add nano-silicon dioxide hollow sphere, ultrasonic agitation 1h, then; 4 are added, 4 after 60 DEG C of return stirring 12h ^'-diaminodiphenyl oxide, divided by appropriate pyromellitic acid anhydride and join in the middle of system 6 times, when both ratios reach equivalent, system viscosity sharply rises, there is rod climbing phenomenon, continue to stir 24h under obtained nano-silicon dioxide hollow sphere/graphene oxide/polyamic acid solution room temperature;

(4) by obtained nano-silicon dioxide hollow sphere-graphene oxide/polyamic acid solution, through automatic film paving machine film forming on glass, be placed in baking oven, gradient increased temperature imidization, the control of hot imidization process temperature is: 80 DEG C, 120 DEG C, 150 DEG C, 180 DEG C, 200 DEG C, 250 DEG C, 300 DEG C each 30min;

(5) treat naturally cooling, the sheet glass with nano-silicon dioxide hollow sphere-graphene oxide/polyimide composite film is put into deionized water and carries out demoulding, put into loft drier after drying and carry out processed.

2. SiO according to claim 1 ₂the method for making of hollow ball/graphene oxide/polyimide composite film, it is characterized in that: described nano-silicon dioxide hollow sphere is loaded in graphene oxide, graphene oxide is through 4, the process of 4 '-diaminodiphenyl oxide, the two passes through chemical bond linkage, the interlamellar spacing of graphene oxide microplate is increased further, being conducive to described hollow silica ball enters between graphene oxide lamella, to peel off further, not only make to be conducive to graphene oxide dispersion, more contribute to three phase materials being uniformly distributed in recombination process, this process need under protective atmosphere, nitrogen protection and argon shield.

3. SiO according to claim 1 ₂the method for making of hollow ball/graphene oxide/polyimide composite film, is characterized in that: described nano-silicon dioxide hollow sphere/graphene oxide/polyimide three components be compounded with help reduce polyimide specific inductivity and improve its mechanical property.

4. SiO according to claim 1 ₂the method for making of hollow ball/graphene oxide/polyimide composite film, is characterized in that: by regulating the ratio of hollow silica ball and graphene oxide to change composite polyimide material performance in described nano-silicon dioxide hollow sphere/graphene oxide/polyimide three components matrix material.