KR20120052605A - Manufacturing method of thermal conduction adhesive and sheet using thermal conduction adhesive thereby - Google Patents

Abstract

PURPOSE: A manufacturing method of a conductive adhesive is provided to maintain dispersion stability, to fill nano-sized metal oxide between micro-sized metal oxide/carbon nanotube nanocomposite particles. CONSTITUTION: A manufacturing method of a conductive adhesive comprises: a step of surface-modifying carbon nanotubes and dispersing into distilled water; a step of forming metal oxide/carbon nanotube composite sol by adding purified metal precursor to the distilled water; a step of manufacturing metal oxide/carbon nanotube composite by sintering the composite sol; a step of manufacturing metal oxide sol through hydro thermal reaction of the distilled water and through solvent replacement; and a step of manufacturing a heat-conductive adhesive by dispersing the composite and the metal oxide sol into solvent, and adding a monomer and reaction initiator.

Description

Manufacture method of thermal conduction adhesive and sheet using thermal conduction adhesive according to the present invention

The present invention relates to a method of manufacturing a thermally conductive adhesive and a thermally conductive adhesive sheet using the same, to facilitate the dispersion of thermally conductive particles in a monomer to improve dispersion stability to prepare a thermally conductive adhesive for improving physical properties of the thermally conductive adhesive. The present invention relates to a thermally conductive adhesive sheet using the thermally conductive adhesive prepared by the method.

Along with the development of the electrical and electronics industry, small and high integration of electrical and electronic component devices is required, and thus, a serious problem of increasing the thermal stress caused by the retention of heat generated inside the device and degrading the reliability of the component device is emerging.

In order to solve this problem, the structure of dissipating heat by using a heat pipe or the like was previously reviewed, but as a method for reducing the volume due to slimming of the display, it is more preferable to use a thermally conductive adhesive in which the thermally conductive particles are dispersed in a polymer. It has been known to be efficient.

The polymer used in the thermally conductive adhesive provides adhesiveness between the additives in the adhesive, and the thermally conductive particles transmit and release heat generated from the electrical and electronic component elements in the adhesive to the heat sink. The thermally conductive particles may be made of a material having thermal conductivity and at the same time being electrically insulating.

However, the conventional thermally conductive adhesive has a disadvantage in that dispersion of the thermally conductive particles in the polymer is not easy and dispersion stability is degraded due to the reaggregation of the thermally conductive particles, thereby failing to properly perform the function as the original thermally conductive adhesive.

In addition, when used in high heat generating components such as LED lighting, the heat conduction efficiency is less than expected, there has been a limit to use.

The present invention is to solve the above problems, to facilitate the dispersion of the thermally conductive particles in the polymer to improve the dispersion stability to improve the physical properties of the thermally conductive pressure-sensitive adhesive manufacturing method and thermally conductive pressure-sensitive adhesive prepared thereby The purpose is to provide.

The present invention is to achieve the above object, the first step of surface-modifying the carbon nanotubes by acid treatment to disperse in distilled water; A second step of forming a metal oxide / carbon nanotube complex sol by adding a purified metal precursor to distilled water in which the carbon nanotubes are dispersed; Sintering the metal oxide / carbon nanotube composite sol to prepare a metal oxide / carbon nanotube composite having a metal oxide attached to a surface of the carbon nanotube; A fourth step of preparing a metal oxide sol through hydrothermal reaction and solvent replacement with distilled water to which the purified metal precursor is added; A fifth step of preparing a thermally conductive adhesive by dispersing the metal oxide / carbon nanotube composite and the metal oxide sol in a solvent to add a monomer and a reaction initiator to produce a thermally conductive adhesive; It is a technical point.

In addition, the metal oxide, it is preferable to use any one of aluminum oxide, titanium dioxide, silicon dioxide, magnesium oxide, beryllium oxide and zirconium dioxide.

In addition, the solvent of the fourth step is ethyl acetate, butyl acetate, methyl ethyl ketone, cyclohexane, dichloroethane, dichlorobenzene, heptane, toluene, n-butanol, xylene, dimethylformamide, N-methylpyrrolidone , 2-ethylhexyl acrylate, n-butyl acrylate, lauryl acrylate, lauryl methacrylate, methyl acrylate, isooctyl acrylate, isodecyl acrylate, acrylic acid, methacrylic acid, styrene, ethyl meth Acrylate, n-butyl methacrylate, isobutyl methacrylate, t-butyl methacrylate, vinyl chloride, vinyl acetate, acrylonitrile, ethyl acrylate, isobutyl acrylate, 2-ethylhexyl methacrylate, Ethylene, octadecyl methacrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, dimethylaminoethyl methacrylate, t-butylami Ethyl methacrylate, diethylaminoethyl methacrylate, glycidyl methacrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, itaconic acid, maleic acid, acrylamide and N-methylol acrylic Preference is given to using any of the amides.

In addition, the solvent of the fifth step is ethyl acetate, butyl acetate, methyl ethyl ketone, cyclohexane, dichloroethane, dichlorobenzene, heptane, toluene, n-butanol, xylene, dimethylformamide and N-methylpyrrolidone It is preferable to use either.

In addition, the monomer is 2-ethylhexyl acrylate, n-butyl acrylate, lauryl acrylate, lauryl methacrylate, methyl acrylate, isooctyl acrylate, isodecyl acrylate, acrylic acid, methacrylic acid, Styrene, ethyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, t-butyl methacrylate, vinyl chloride, vinyl acetate, acrylonitrile, ethyl acrylate, isobutyl acrylate, 2-ethyl Hexyl methacrylate, ethylene, octadecyl methacrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, dimethylaminoethyl methacrylate, t-butylaminoethyl methacrylate, diethylamino Ethyl methacrylate, glycidyl methacrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, itaconic acid, maleic acid, arc Amide and N- methyl it is preferred that all or any of them use a mixture of two or more in the acrylamide.

The reaction initiator may be any one of hydrogen peroxide, potassium persulfate, azobisisobutylonitrile, benzoyl peroxide, acetyl peroxide, diauryl peroxide, di tert-butyl peroxide and cumyl hydroperoxide. It is preferable to use one.

In addition, the present invention is a thermally conductive adhesive sheet prepared by adding a curing agent to the thermally conductive adhesive prepared by the above method and coated on a release film, and another technical gist of the curing agent is diphenylmethane diisocyanate, gyro Use of any of di-isocyanate, isophorone diisocyanate, toluene diisocyanate, hexamethylene diisocyanate, butylmelamine, polyethyleneglycol, diglycidyl ether, trimethylolpropane, triglycidyl ether and aluminum acetylacetonate It is desirable to.

By the means for solving the above problems, the present invention maintains the dispersion stability by the monomer and the additives added thereto, and by filling the nano-sized metal oxide between the micro-sized metal oxide / carbon nanotube composite particles, There is an effect of providing a thermally conductive adhesive with improved conductivity.

In addition, by using the thermally conductive adhesive according to the present invention by adhering to the heat sink of the heat dissipation plate of the electrical and electronic parts, in particular, the heat generating parts such as LED lighting, etc., the heat dissipation of the heat is efficiently achieved while maintaining the electrical insulation It has the effect of contributing to the stable use of.

The present invention relates to a method for producing a thermally conductive adhesive comprising monomers, nano and micro-sized metal oxides and carbon nanotube composites, and has excellent dispersion stability of additives added to the thermally conductive adhesive. It is to provide a thermally conductive adhesive having excellent characteristics.

In the present invention, first, the carbon nanotubes are surface-modified through acid treatment, dispersed in distilled water, hydrolyzed by addition of purified metal precursors, and metal oxides having carbon nanotubes therein through peptizing reactions. A carbon nanotube complex sol is formed. That is, the metal oxide / carbon nanotube composite sol is a metal oxide (nano size) is attached to the surface of the long carbon nanotube (micro size) to form a sol.

The metal oxide is preferably any one of aluminum oxide, titanium dioxide, silicon dioxide, magnesium oxide, beryllium oxide and zirconium dioxide, the metal precursor is a material capable of producing the metal oxide through hydrolysis. It is okay if. For example, when the metal oxide is aluminum oxide, aluminum isopropoxide, aluminum trisec-butoxide, aluminum tert-butoxide, aluminum tri-ethoxide or the like is used as the metal precursor.

In the metal oxide / carbon nanotube composite sol, a sintering process is performed to increase the crystallinity of the metal oxide portion, thereby producing a metal oxide / carbon nanotube composite having a metal oxide attached to the surface of the carbon nanotube. do.

Then, the purified metal precursor is added to distilled water to hydrolysis, and then a metal oxide sol having high crystallinity is prepared through peptization reaction and solvent replacement in a hydrothermal reactor. The metal oxide is preferably any one of aluminum oxide, titanium dioxide, silicon dioxide, magnesium oxide, beryllium oxide and zirconium dioxide, the metal precursor is a material capable of producing the metal oxide through hydrolysis. It is okay if. For example, when the metal oxide is aluminum oxide, aluminum isopropoxide, aluminum trisec-butoxide, aluminum tert-butoxide, aluminum tri-ethoxide or the like is used as the metal precursor.

Thereafter, the metal oxide / carbon nanotube composite and the high crystalline metal oxide sol are dispersed in a solvent, and then a monomer and a reaction initiator are added to prepare a pressure-sensitive adhesive to complete the thermally conductive pressure-sensitive adhesive.

Thereafter, in order to manufacture a thermally conductive adhesive sheet, a curing agent is added to the thermally conductive adhesive and coated on a release film to prepare a thermally conductive adhesive sheet.

Here, the solvent used in the solvent replacement process for preparing the metal oxide sol is ethyl acetate, butyl acetate, methyl ethyl ketone, cyclohexane, dichloroethane, dichlorobenzene, heptane, toluene, n-butanol, xylene, dimethyl Formamide, N-methylpyrrolidone, 2-ethylhexyl acrylate, n-butyl acrylate, lauryl acrylate, lauryl methacrylate, methyl acrylate, isooctyl acrylate, isodecyl acrylate, acrylic acid, Methacrylic acid, styrene, ethyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, t-butyl methacrylate, vinyl chloride, vinyl acetate, acrylonitrile, ethyl acrylate, isobutyl acrylate 2-ethylhexyl methacrylate, ethylene, octadecyl methacrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate Latex, dimethylaminoethyl methacrylate, t-butylaminoethyl methacrylate, diethylaminoethyl methacrylate, glycidyl methacrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, ita Any one of cholic acid, maleic acid, acrylamide and N-methylol acrylamide is used.

In addition, the solvent used to disperse the metal oxide / carbon nanotube complex and the metal oxide sol is ethyl acetate, butyl acetate, methyl ethyl ketone, cyclohexane, dichloroethane, dichlorobenzene, heptane, toluene, n-butanol , Using any one of xylene, dimethylformamide and N-methylpyrrolidone.

In addition, the monomer is 2-ethylhexyl acrylate, n-butyl acrylate, lauryl acrylate, lauryl methacrylate, methyl acrylate, isooctyl acrylate, isodecyl acrylate, acrylic acid, methacrylic acid, Styrene, ethyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, t-butyl methacrylate, vinyl chloride, vinyl acetate, acrylonitrile, ethyl acrylate, isobutyl acrylate, 2-ethyl Hexyl methacrylate, ethylene, octadecyl methacrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, dimethylaminoethyl methacrylate, t-butylaminoethyl methacrylate, diethylamino Ethyl methacrylate, glycidyl methacrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, itaconic acid, maleic acid, arc It uses any one of the amide and N- methylol acrylamide.

The reaction initiator may be any one of hydrogen peroxide, potassium persulfate, azobisisobutylonitrile, benzoyl peroxide, acetyl peroxide, diauryl peroxide, di tert-butyl peroxide and cumyl hydroperoxide. Use one.

Moreover, the said hardening | curing agent is diphenylmethane diisocyanate, xylene diisocyanate, isophorone diisocyanate, toluene diisocyanate, hexamethylene diisocyanate, butyl melamine, polyethyleneglycone, diglycidyl ether, trimethylolpropane, triglycol Any one of cydyl ether and aluminum acetylacetonate is used.

The thermally conductive adhesive prepared as described above has a metal oxide attached to the surface of the carbon nanotubes, and has a length of several micrometers, and by adding a metal oxide sol having a nano size to it, a microsized metal oxide It is possible to further increase the thermal conductivity by filling the metal oxide between the / carbon nanotube composite particles.

Hereinafter will be described for the embodiment of the present invention.

0.3 g of carbon nanotubes were added to 100 ml of a mixture of sulfuric acid / nitric acid, sonicated under a bath for 6 hours, filtered, and dried. Through the above method, carbon nanotubes to which carboxyl and hydroxyl groups were provided on the surface were obtained.

Next, 0.3 g of the carbon nanotubes to which the functional group is provided are dispersed by applying ultrasonic waves to 443 ml of distilled water. 100 g of aluminum isopropoxide was added to distilled water in which carbon nanotubes were dispersed and stirred at 90 ° C. for 2 hours, and then 5 g of nitric acid was added and stirred at 90 ° C. for 24 hours. Through the above process, an alumina / carbon nanotube composite sol having carbon nanotubes was prepared.

The alumina / carbon nanotube composite sol was dried at 100 ° C. for 24 hours, and sintered to prepare alumina / carbon nanotube composite powder having alumina attached to the surface of the carbon nanotube. The prepared alumina / carbon nanotube composite powder was surface-treated with acrylic silane, and then dispersed in toluene by applying a ball mill process and ultrasonic waves. Through this process, the agglomeration state is released during the sintering process, and toluene in which the composite powder is stably dispersed is obtained.

Then, 11 g of aluminum isopropoxide was added to 100 ml of distilled water, followed by stirring at 90 ° C. for 2 hours, and then 1 g of nitric acid was added and stirred at 150 ° C. and 200 atm for 1 hour in a hydrothermal reactor. After the reaction, the concentrated solvent was replaced with 10 times the organic solvent. Through the above process, alumina sol having high crystallinity dispersed in an organic solvent was prepared.

After sufficiently stirring 60 g of the alumina / carbon nanotube complex solution dispersed in toluene and 10 g of highly crystalline alumina sol dispersed in an organic solvent, 18 g of 2-ethylhexyl acrylate, 6 g of butyl acrylate, and methyl acryl were used as monomers. A thermally conductive adhesive was prepared by polymerizing 3 g rate, 3 g acrylic acid and 0.3 g of azobisisobutylonitrile as a reaction initiator at 70 ° C. Thereafter, 0.6 g of aluminum acetylacetonate was mixed as a curing agent in order to prepare a thermally conductive adhesive sheet, followed by sufficiently stirring.

In addition, the thermally conductive adhesive was degassed under reduced pressure, coated with a thickness of 0.3 mm on a release film, and dried at 100 ° C. for 2 hours to prepare a thermally conductive adhesive sheet.

The thermally conductive adhesive or the thermally conductive adhesive sheet maintains dispersion stability by monomers and additives added thereto, and together with the microsized metal oxide / carbon nanotube composite and the nanosized metal oxide, the microsized metal By filling a nano-sized metal oxide between the oxide / carbon nanotube composite particles, the thermal conductivity is further enhanced. Accordingly, by coating or sticking to the heat sink of the heat dissipation plate of the electric and electronic parts, especially the heat generating parts such as LED lighting, it will contribute to the stable use of the electric and electronic parts by maintaining heat insulation efficiently while maintaining electrical insulation. Judging.

Claims (8)

A first step of surface-modifying the carbon nanotubes by acid treatment and dispersing them in distilled water;
A second step of forming a metal oxide / carbon nanotube complex sol by adding a purified metal precursor to distilled water in which the carbon nanotubes are dispersed;
Sintering the metal oxide / carbon nanotube composite sol to prepare a metal oxide / carbon nanotube composite having a metal oxide attached to a surface of the carbon nanotube;
A fourth step of preparing a metal oxide sol through hydrothermal reaction and solvent replacement with distilled water to which the purified metal precursor is added;
And dispersing the metal oxide / carbon nanotube composite and the metal oxide sol in a solvent to add a monomer and a reaction initiator to prepare a thermally conductive adhesive. 5. The method of claim 1, wherein the metal oxide,
Method for producing a thermally conductive adhesive, characterized in that any one of aluminum oxide, titanium dioxide, silicon dioxide, magnesium oxide, beryllium oxide and zirconium dioxide. The method of claim 1, wherein the solvent of the fourth step,
Ethyl acetate, butyl acetate, methyl ethyl ketone, cyclohexane, dichloroethane, dichlorobenzene, heptane, toluene, n-butanol, xylene, dimethylformamide, N-methylpyrrolidone, 2-ethylhexyl acrylate, n- Butyl acrylate, lauryl acrylate, lauryl methacrylate, methyl acrylate, isooctyl acrylate, isodecyl acrylate, acrylic acid, methacrylic acid, styrene, ethyl methacrylate, n-butyl methacrylate, Isobutyl methacrylate, t-butyl methacrylate, vinyl chloride, vinyl acetate, acrylonitrile, ethyl acrylate, isobutyl acrylate, 2-ethylhexyl methacrylate, ethylene, octadecyl methacrylate, 2- Hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, dimethylaminoethyl methacrylate, t-butylaminoethyl methacrylate, diethyl Using any of minoethyl methacrylate, glycidyl methacrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, itaconic acid, maleic acid, acrylamide and N-methylol acrylamide Method for producing a thermally conductive adhesive, characterized in that. The method of claim 1, wherein the solvent of the fifth step,
Ethyl acetate, butyl acetate, methyl ethyl ketone, cyclohexane, dichloroethane, dichlorobenzene, heptane, toluene, n-butanol, xylene, dimethylformamide and N-methylpyrrolidone Method for producing a thermally conductive adhesive. The method of claim 1, wherein the monomer,
2-ethylhexyl acrylate, n-butyl acrylate, lauryl acrylate, lauryl methacrylate, methyl acrylate, isooctyl acrylate, isodecyl acrylate, acrylic acid, methacrylic acid, styrene, ethyl methacryl Latex, n-butyl methacrylate, isobutyl methacrylate, t-butyl methacrylate, vinyl chloride, vinyl acetate, acrylonitrile, ethyl acrylate, isobutyl acrylate, 2-ethylhexyl methacrylate, ethylene Octadecyl methacrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, dimethylaminoethyl methacrylate, t-butylaminoethyl methacrylate, diethylaminoethyl methacrylate, glyc Cydyl methacrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, itaconic acid, maleic acid, acrylamide and N-methylol A method for producing a thermally conductive adhesive, characterized in that any one of acrylamide or a mixture of two or more thereof is used. The method of claim 1, wherein the reaction initiator,
Characterized in that any one of hydrogen peroxide, potassium persulfate, azobisisobutylonitrile, benzoyl peroxide, acetyl peroxide, diauryl peroxide, di tert-butyl peroxide and cumyl hydroperoxide is used. The manufacturing method of the thermally conductive adhesive which makes. A thermally conductive adhesive sheet prepared by coating a release film by adding a curing agent to the thermally conductive adhesive prepared in any one of claims 1 to 6. The method of claim 7, wherein the curing agent,
Diphenylmethane diisocyanate, xylene diisocyanate, isophorone diisocyanate, toluene diisocyanate, hexamethylene diisocyanate, butyl melamine, polyethyleneglycol, diglycidyl ether, trimethylolpropane, triglycidyl ether and aluminum acetyl The thermally conductive adhesive sheet which uses either acetonate.