KR20040059346A - An organic/inorganic nanohybrid and preparation method thereof using an aminosilane precusor - Google Patents

Abstract

PURPOSE: A thermosetting resin composition, a method for preparing an organic-inorganic nanocomposite material by using the composition and an organic-inorganic nanocomposite material prepared by the method are provided, to suppress the shrinkage of a resin and the formation of pores between a resin and an inorganic material, thereby improving the physical properties and dimension stability of an organic-inorganic nanocomposite material. CONSTITUTION: The thermosetting resin composition comprises 100 parts by weight of an organic polymer resin; and 20-30 parts by weight of an aminosilane. Preferably the organic polymer resin is an epoxy resin; and the aminosilane is selected from the group consisting of a dialkylaminosilane, a trialkylaminosilane, a tetraalkylaminosilane, a diarylaminosilane, a triarylaminosilane, a tetraarylaminosilane and their mixtures. The organic-inorganic nanocomposite material is prepared by carrying out sol-gel reaction and curing reaction of the composition simultaneously. Preferably the organic-inorganic nanocomposite material is an epoxy-silica nanocomposite material.

Description

Organic-Inorganic Nanocomposites and Aminosilane Precursors Manufacture Method of the Same {AN ORGANIC / INORGANIC NANOHYBRID AND PREPARATION METHOD THEREOF USING AN AMINOSILANE PRECUSOR}

The present invention relates to a method for preparing an organic-inorganic nanocomposite material filled with an inorganic resin of nano size in an epoxy resin.

Epoxy resins as organic matrices have excellent thermal and chemical properties, and have very good bonding to a variety of materials. Thus, epoxy resins have a wide range of uses, such as coatings, adhesives, composite materials, and semiconductor encapsulants. That is, the epoxy resin that is liquid at room temperature has excellent processing convenience, and has been in the spotlight as a main material of the precision parts material industry. However, relatively low physical properties compared to inorganic materials, for example, weak heat resistance and high coefficient of thermal expansion, have recently limited their use in the field of electronic semiconductor structural materials such as epoxy molding compound (EMC).

When nano-sized inorganic particles such as silica are used as the reinforcing agent in epoxy resins, a new concept of epoxy nanocomposites can be obtained with the high physical properties, low thermal expansion and excellent strength required by the precision materials industry. .

Conventional composite materials have improved mechanical strength and thermal stability by adding inorganic fillers to organic polymer materials, but have recently been developed to provide high functionality to materials while maximizing their properties by compounding at the molecular dispersion level.

Since the size of the hybrid dispersed phase obtained by the sol-gel process is generally at the nanometer level or at the molecular size level, the interfacial repulsion between heterogeneous components can be overcome, and the material is morphologically fine, thus obtaining a transparent and diverse performance material. .

In general, hybrids of organic polymers and silica have various characteristics, and are excellent in water resistance, solvent resistance, weather resistance, radiation resistance, corrosion resistance, oxygen permeability, and insulation. In fact, there are various methods of preparing a hybrid by the sol-gel method, and the characteristics of the hybrid depending on the structure of the organic-inorganic component, the degree of covalent bonding between the organic-inorganic substance, the morphological phase, and the mutual penetration between the organic-inorganic phase, etc. It can be obtained variously from this elastic body to a highly rigid material.

In general, when an organic-inorganic hybrid is prepared by mixing the hydrolyzate of an alkoxide with an organic component oligomer or polymer having a reactive group, it is necessary to form a hydrogen bond in the organic-inorganic component, or to cause a chemical reaction to occur. A very even morphological structure can be obtained. However, there are two problems with this method. One is that the types of polymers dissolved in the multi-component sol-gel solution are extremely limited, so that even if the initial solubility is improved by using a cosolvent, phase separation often occurs before the silicate network is completed. . The other sol-gel process uses tetraethoxysilane ("TEOS") as an inorganic precursor. TEOS is hydrolyzed by a catalyst to produce alcohol, a byproduct, and alcohol during the drying process. As it is vaporized, very fine cracks, voids, and the like occur in the resulting composite material, causing severe shrinkage.

In order to overcome the first problem, a method (simultaneous interpenetrating network, hereinafter referred to as "SIPN") to produce an organic polymer and an inorganic component in-situ at the same time was tried. The advantage of the SIPN method over the method of dispersing the polymer is that when crosslinking the organic polymer using a high functional monomer, it has a mixed state at the molecular level interpenetrating with the inorganic material. In other words, since the organic-inorganic polymers are simultaneously produced at the same time, a uniform composite material can be obtained even if they are insoluble in each other in a normal state. However, even with this method, the second pointed out problem, that is, the shrinkage problem caused by using TEOS, is not solved.

Accordingly, in order to prevent shrinkage, Novak et al. Used a new alkoxysilane having an alkoxy functional group capable of causing a polymerization reaction instead of a general alkoxysilane. That is, when the same compound as the compound released during the hydrolysis of the silica precursor is used as a cosolvent, and a polymerization catalyst is used, all the components are in a polymerizable combination, so that no volatile components exist and a large scale shrinkage is achieved. The phenomenon does not occur, and the composite material obtained here has physical properties superior to the mechanical properties of each component.

However, even in this case, since the alkoxysilane is used, alcohol is produced during the hydrolysis / condensation reaction to shrink the epoxy resin, thereby forming voids between the epoxy resin and the silica, thus preparing the alkoxysilane as a precursor of the inorganic component. The fundamental problem of degrading the physical and thermal properties of the resulting composite material is not solved.

Accordingly, an object of the present invention is a thermosetting resin composition composed of an organic polymer resin and an aminosilane capable of forming an organic-inorganic nanocomposite by a curing reaction, an organic-inorganic material having excellent physical properties and low thermal expansion rate prepared therefrom. The present invention provides a method for producing a nanocomposite material and an organic-inorganic nanocomposite material which can prevent shrinkage and void formation of a resin during a curing reaction.

1 shows the pH change of the reaction mixture of Example 3. FIG.

2 shows the FT-IR spectrum of the reaction mixture of Example 3. FIG.

3 is an electron micrograph of the reaction mixture of Example 3. FIG.

Figure 4 shows the glass transition temperature of the epoxy nanocomposites prepared in Example 3, Comparative Examples 1 and 2.

Figure 5 shows the elastic modulus of the epoxy nanocomposites prepared in Example 3, Comparative Examples 1 and 2.

Figure 6 shows the linear thermal expansion coefficient of the epoxy hybrid prepared in Example 3, Comparative Examples 1 and 2.

7A, 7B and 7C show TEM photographs of Comparative Example 1, Comparative Example 2 and Example 3, respectively.

The object of the present invention as described above is achieved through the use of aminosilane as precursor for inorganic packed particles of organic-inorganic nanocomposites.

In the present invention, there is provided a thermosetting resin composition composed of an organic polymer resin and an aminosilane, an organic-inorganic nanocomposite material prepared therefrom, and a method of manufacturing the same.

In the present invention, the aminosilane not only acts as a precursor for the inorganic filler particles of the nanocomposite material, but its hydrolysis product amine acts as a catalyst for the sol-gel reaction and a curing agent for the curing reaction of the organic polymer resin. do. Therefore, in the present invention for producing an organic-inorganic nanocomposite material from a composition consisting of an organic polymer resin and an aminosilane, it is not necessary to separately add a catalyst for the sol-gel reaction and a curing agent for the curing reaction, and to volatilize the alcohol. Since shrinkage phenomenon and void formation of the composite material caused can be avoided, it is possible to obtain an organic-inorganic nanocomposite material having excellent physical and thermal properties.

The resin composition of the present invention for producing a nanocomposite material is composed of an organic polymer resin and aminosilane, the mixing ratio of which is 20 to 30 parts by weight of aminosilane with respect to 100 parts by weight of the organic polymer resin.

The aminosilane may be di-, tri- or tetraalkylaminosilane or arylaminosilane which can be synthesized through the reaction of alkylamine or arylamine with chlorosilane. In preparing the aminosilane, trichlorosilane is usually used in an amount of 20 to 40% by volume with respect to the solvent, and in order to obtain an aminosilane substituted with three alkylamines or arylamines, an alkylamine or an arylamine is used. It can be used at 250-300% by volume relative to trichlorosilane. Examples of the alkylamine and arylamine include linear alkyl secondary amines, piperidine, or alkyl substituted piperies having two alkyl groups having 10 or less carbon atoms, such as diethylamine, dipropylamine, dibutylamine, and ethylpropylamine. Aryl secondary amines in which at least one of cyclic alkyl secondary amines such as dean, and secondary amines are aryl groups such as benzene, toluene and the like. Tripiperidinylsilane (hereinafter referred to as "TPS") as an example of aminosilane is prepared according to Scheme 1 below using diethyl ether (hereinafter referred to as "DEE") as a solvent from trichlorosilane and piperidine. Can be prepared.

On the other hand, the organic polymer resin may be an epoxy resin, for example, it is best to use a material represented by the formula (1), that is, DGEBA (diglycidyl ether of biphenyl-A) type. However, the present invention is not limited thereto, and any epoxy resin having 2 to 4 epoxy functional groups per molecule can be used.

The aminosilanes generate amines during the sol-gel reaction in which the silica component is formed, thereby inducing curing of the organic polymer resin with the amines on the silica surface. The curing process of the resin usually consists of a primary cure carried out at 80 ° C. for 12-18 hours followed by a post cure carried out at 120 ° C. for 2-4 hours.

In the method for producing an organic-inorganic nanocomposite according to the present invention, an in situ polymerization method, i.e., a composition in which a silica is formed by a sol-gel reaction and a curing reaction of an organic polymer resin is composed of an organic polymer resin and an aminosilane It's a method that happens at the same time. Therefore, the manufacturing method of the organic-inorganic nanocomposite material according to the present invention can be applied without limitation to the polymerization method of a thermosetting organic polymer resin, in particular an epoxy resin that is commonly used.

The content of the inorganic particles in the organic-inorganic nanocomposite material of the present invention prepared by the method described above is about 5-10 wt%, and the thermal expansion rate is 20% or more lower than that of the organic polymer resin containing no inorganic particles. Has

Example

Hereinafter, the present invention will be described in more detail with reference to Examples. However, the embodiments are only examples of the present invention, and the scope of the present invention is not limited thereto.

Example 1 Preparation of TPS

Trichlorosilane was dissolved in diethyl ether at a concentration of 20% by volume. Piperidine in an amount of 250% by volume relative to trichlorosilane was placed in a new reactor filled with nitrogen and equipped with an ice bath. The trichlorosilane solution prepared above was added to the reactor containing piperidine at a rate of 2 ml / min, stirred for 3 hours at 0 ° C. for sufficient reaction, and the temperature was raised to room temperature for a further 2 hours. It was. Hydrogen chloride gas generated from the reaction of trichlorosilane and piperidine was neutralized by installing a trap containing a dilute aqueous sodium hydroxide solution, and the hydrochloride salt of piperidine was removed by filtration after completion of the reaction. Centrifugation was performed three times or more to completely remove the hydrochloride salt of piperidine, and the supernatant was evaporated at 90 ° C. in an evaporator for at least 5 hours to completely remove piperidine to obtain the precursor compound TPS. The yield of TPS produced was approximately 80%.

Example 2: Sol-Gel Reaction of TPS

To demonstrate that TPS acts as a catalyst precursor during the epoxy curing process, TPS is dissolved at a rate of 7-12% by weight relative to 100 g of tetrahydrofuran (hereinafter referred to as "THF") and then dehydrated with stirring. About 5 ml of ionized water was added at a rate of 0.03-0.05 wt% / min relative to THF to induce the hydrolysis and condensation reaction (ie sol-gel reaction) of TPS as shown in Schemes 2 and 3 below, The progress of the reaction was confirmed from the pH change and FR-IR spectrum of the reaction mixture.

≡Si-NR + H ₂ O → ≡Si-OH + RNH

≡Si-NR + ≡Si-OH → ≡Si-O-Si≡ + RNH

In Schemes 2 and 3, RNH represents piperidine.

Figure 1 shows the pH change of the reactants, showing that the pH of the reaction mixture rises because TPS in THF is hydrolyzed to its own catalytic function in the presence of water to produce piperidine.

2 shows the FT-IR spectrum of the reaction mixture. A strong Si-O bond peak was observed around 1100 cm ^-1 , similar to the FT-IR spectrum of typical silica particles. This indicates that silica was produced while the TPS was subjected to hydrolysis and condensation with water.

3 is an electron micrograph of the reaction mixture. It can be seen that the spherical silica particles produced by the hydrolysis and condensation reaction of TPS do not show much difference from the silica particles produced from the sol-gel reaction of TEOS under basic conditions.

From these experimental results, it can be seen that the TPS prepared according to Example 1 follows the behavior of the sol-gel reaction required for the preparation of the organic-inorganic hybrid.

Example 3

The epoxy was dried under reduced pressure in a vacuum oven at 60 ° C. for 5 hours to remove bubbles and moisture trapped in the epoxy. 20-30 parts by weight of TPS prepared according to Example 1 was added to 100 parts by weight of the dried epoxy, mixed evenly, and dried under reduced pressure for 5 hours in a vacuum oven at 60 ° C. to completely remove bubbles and water. While slowly stirring the mixture, 3 g of deionized water was added dropwise at a rate of 0.1 ml / min. Hydrolysis was carried out for 1 hour, and further degassed by drying under reduced pressure in a vacuum oven at 60 ℃. The obtained material was placed in a mold, first cured at 80 ° C. for 16 hours, and post-cured at 120 ° C. for 2 hours to prepare an epoxy-silica nanocomposite.

Comparative Example 1

The epoxy resin subjected to defoaming in a vacuum oven was placed in a mold, first cured at 80 ° C. for 16 hours, and post-cured at 120 ° C. for 2 hours to prepare a neat epoxy cured resin.

Comparative Example 2

Epoxy-silica nanocomposites were prepared by placing a mixture of epoxy resin and TEOS degassed in a vacuum oven into a mold, first curing at 80 ° C. for 16 hours, and post-curing at 120 ° C. for 2 hours. This method corresponds to a typical method for producing epoxy-silica nanocomposites according to the prior art.

Example 4: Physical property test of epoxy nanocomposite

The dynamic mechanical thermal analysis (DMTA) of the epoxy-silica nanocomposites of the present invention prepared in Example 3 and the epoxy composites prepared in Comparative Examples 1 and 2 were carried out. And 5. From this, the glass transition temperature and elastic modulus of the epoxy-silica composite specimens prepared in Comparative Example 2 and Example 3 were higher than those of the knitted epoxy cured resin prepared in Comparative Example 1, and compared to the composite material of Comparative Example 2. It can be seen that the glass transition temperature and elastic modulus of the composite material of Example 3 increased significantly. This indicates that the composite material of Example 3 has a better mixing at the molecular level between the organic component and the inorganic component than the composite material of Comparative Example 2, that is, the distribution of silica particles is more uniform. In addition, the content of the silica in the organic-inorganic nanocomposite material obtained in Example 3 is 4% by weight, it can be seen that the mechanical properties increased even though the content is very low. From these results, it was confirmed that the method of preparing epoxy-silica nanocomposites using an aminosilane such as TPS as a precursor of silica was superior to the method using an alkoxysilane such as TEOS.

Figure 6 shows the linear thermal expansion coefficient of the epoxy hybrid prepared in Example 3, Comparative Examples 1 and 2, wherein the specimen prepared in Example 3 is at least 20% lower than the specimen prepared in Comparative Examples 1 and 2, respectively It can be seen that it has a coefficient of thermal expansion. These results confirm that epoxy nanocomposites prepared using TPS have excellent dimensional stability, from which the epoxy-silica nanocomposites prepared according to the present invention are the most required for materials in the field of electronic materials. You can see that you are meeting important items.

7A is a TEM photograph of a material prepared in Comparative Example 1, FIG. 7B is a TEM photograph of a material prepared in Comparative Example 2, and FIG. 7C is a TEM photograph of a material prepared in Example 3 will be. In the case of FIG. 7B in which silica components are obtained from TEOS, it can be seen that silica particles having a size of several hundred nm to several μm exist in a phase separated state from the epoxy matrix. However, in the case of FIG. 7C in which the silica component is obtained from the TPS, it can be seen that the silica component phase-separates from the epoxy and thus does not exhibit the behavior of forming an independent region. It means that it is evenly dispersed in the molecular region in the resin.

A thermosetting resin composition for preparing an organic-inorganic nanocomposite, an organic-inorganic nanocomposite prepared therefrom, and an aminosilane, as a precursor for inorganic filler particles in the nanocomposite, comprising an organic polymer resin and an aminosilane according to the present invention. By using the above, there has been provided a method for producing an organic-inorganic nanocomposite material which can prevent shrinkage phenomenon and void formation of the organic polymer resin during curing reaction. The organic-inorganic nanocomposites prepared by the method of the present invention exhibit excellent physical properties and dimensional stability compared to the conventional nanocomposites, and thus may be applied to electronic materials such as EMC, die bonding, and under-cut. It is expected to be. In addition, the manufacturing method according to the present invention may be applied to the production of organic-inorganic nanocomposites using polymers other than epoxy resins as raw materials.

Claims (16)

A thermosetting resin composition for preparing an organic-inorganic nanocomposite, comprising 100 parts by weight of an organic polymer resin and 20 to 30 parts by weight of aminosilane. The thermosetting of claim 1, wherein the aminosilane is selected from the group consisting of dialkylaminosilane, trialkylaminosilane, tetraalkylaminosilane, diarylaminosilane, triarylaminosilane, tetraarylaminosilane, and mixtures thereof. Resin composition. 3. The composition of claim 2, wherein said trialkylaminosilane is tripiperidinylsilane. The composition of claim 1, wherein the organic polymer resin is an epoxy resin. The composition of claim 4, wherein the epoxy resin is an epoxy resin of the diglycidyl ether type of biphenyl-A. The composition of claim 1, wherein the organic-inorganic nanocomposite is an epoxy-silica nanocomposite. A method for producing an organic-inorganic nanocomposite, comprising simultaneously performing a sol-gel reaction and a curing reaction of an organic polymer using a thermosetting resin composition composed of an organic polymer resin and an aminosilane. 8. The organic-inorganic inorganic compound according to claim 7, wherein the thermosetting resin composition composed of an organic polymer resin and an aminosilane is hydrolyzed by adding deionized water, and the hydrolysis product is first cured at 80 DEG C, and then post-cured at 120 DEG C. Method for producing nanocomposite material. The group according to claim 7 or 8, wherein the aminosilane is composed of dialkylaminosilane, trialkylaminosilane, tetraalkylaminosilane, diarylaminosilane, triarylaminosilane, tetraarylaminosilane and mixtures thereof. The method chosen from. 10. The process according to claim 9, wherein said trialkylaminosilane is tripiperidinylsilane. The method according to claim 7 or 8, wherein the organic polymer resin is an epoxy resin. 12. The method of claim 11, wherein the epoxy resin is an epoxy resin of the diglycidyl ether type of biphenyl-A. The method of claim 7 or 8, wherein the organic-inorganic nanocomposite is an epoxy-silica nanocomposite. The method according to claim 7 or 8, wherein the thermosetting resin composition consists of 100 parts by weight of an organic polymer and 20-30 parts by weight of aminosilane. Organic-inorganic nanoparticles prepared by the process according to claim 7 or 8, which contain inorganic particles in the range of 5-10% by weight and have a coefficient of thermal expansion of at least 20% compared to organic polymer resins containing no inorganic particles. Composite materials. The organic-inorganic nanocomposite material according to claim 15, wherein the organic polymer resin is an epoxy resin and the inorganic particles are silica.