KR101222502B1 - Silicone-Epoxy-Vinyl Resin Useful for Dispersion and Coupling of Fillers and Method of Producing the Same - Google Patents

Abstract

The present invention relates to a silicone-epoxy-vinyl resin compound and a method for producing the same.
The present invention is a matrix resin that can be easily dispersed and combined with silica powder, silver fine particles, carbon fine particles, etc., which are commonly added as fillers in the manufacturing process of adhesives for electronic products, which is one of the composite materials. For vinyl resins.
The present invention can eliminate the surface treatment or addition processes using expensive binders for dispersing and bonding fillers added to the composite material by preparing a silicone-epoxy-vinyl resin and using it as a matrix resin of the composite type adhesive.

Description

Silicon-Epoxy-Vinyl Resin Useful for Dispersion and Coupling of Fillers and Method of Producing the Same}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an adhesive used in assembling electronic products and a method for manufacturing the same. More particularly, the wettability between the filler and the adhesive used in the addition of silica powder, fillers such as silver fine particles and carbon fine particles, etc. The present invention relates to a silicone-epoxy-vinyl resin having excellent wetting and adhesion properties and a method of preparing the same.

In general, adhesives used to assemble electronic products are often based on epoxy resins having excellent adhesion to substrates and excellent heat resistance and mechanical properties. However, adhesives using epoxy resins have high crosslinking densities and glass transition temperatures, which may cause cracks at low temperatures. Therefore, adhesives are often added with amine-terminated or carboxylic acid-terminated nitrile liquid rubbers to give toughness. Such rubber-added epoxy resins have high viscosity and are transparent before curing but opaque after curing.

Recently, adhesives using silicone resins have begun to be used. Silicone resins have excellent low-temperature characteristics and water resistance, but have a weaker adhesive strength than epoxy resins. Therefore, adhesives capable of producing a cured product of hybridized structures have been developed and introduced as adhesives having both the advantages of epoxy resins and silicone resins.

On the other hand, in order to impart additional properties to such adhesives, various inorganic and metal fine particles are often added. For example, powdery silica is added to impart dimensional stability and thixotropy, and flake type silver fine particles or carbon fine particles such as carbon nanotubes and graphene are added to impart conductivity. These fillers are not satisfactory due to insufficient wetting on matrix resins such as epoxy resins, silicone resins, hybrids of epoxy resins and silicone resins that express adhesion to the substrate through a curing reaction, and are not satisfactory. There are many. Therefore, in order to improve the wetting with these to improve the interfacial bonding, after the surface treatment with a silane compound such as a surfactant is added or additionally added as a binder. However, when the surface of the filler is treated with a binder to wet the matrix resin and impart adhesiveness, an expensive cost must be invested in the manufacturing process, and the surface-treated fillers tend to stick together in the treatment process. It is difficult to express easy and satisfactory performance.

On the other hand, when a binder is simply added, it is difficult for them to volatilize in a high temperature hardening reaction process and to give a desired function. Therefore, it is one of the difficult problems to implement a good interfacial bond through a process of properly treating and dispersing the filler in the production of an adhesive in the form of a composite material imparted with a variety of fillers.

Today, there is a need for the development of adhesives that improve the wettability between the filler and the matrix resin and impart interfacial bonds in the adhesive in the form of composite materials including inorganic and metallic fillers to fully reflect the performance of the filler.

The present invention is to solve the above-mentioned problems of the prior art, to provide a silicon-epoxy-vinyl resin and a method of manufacturing the same, which are well wetted with respect to silica powder, silver powder, carbon-based additives, and the like, which are used as fillers. The purpose is.

When the silicone-epoxy-vinyl resin according to the present invention is used as a matrix, it is not necessary to add a separate binder for wetting and bonding with a filler when preparing a composite material such as a functional adhesive.

In addition, the silicone-epoxy-vinyl resin adhesive according to the present invention exhibits transparent characteristics unlike the case where only three kinds of resin components are mixed.

The present invention relates to a silicone-epoxy-vinyl resin having excellent wettability to a filler and good adhesion, and a method for producing the same.

The present invention provides a silanol-terminated siloxane compound having a functional group of 2 or more from alkoxy silane compound and a hydroxyl-terminated polydimethyl siloxane through a sol-gel reaction, and an epoxy silane compound and a vinyl silane capable of reacting with a silanol-terminated group. Adding the compound to prepare a silicone-epoxy-vinyl resin as a final product.

The silicon-epoxy-vinyl resin compound according to the present invention is preferably prepared by the sol-gel condensation reaction of the silane compound.

In the present invention, the silicone-epoxy-vinyl resin is more preferably a compound represented by the general formula (II) in FIG. 3.

Method for producing a silicone-epoxy-vinyl resin according to the present invention,

a) preparing a silicone resin prepolymer having a silanol functional group of 2 or more from a hydroxyl group terminated polydimethyl siloxane having a weight average molecular weight of 500 to 6000 and an alkoxy silane through a sol-gel reaction in a nitrogen gas atmosphere;

b) adding an epoxy silane and vinyl silane compounds to a silicone resin prepolymer having a silanol functional group of at least 2 to prepare a silicone-epoxy-vinyl resin; It includes.

In the present invention, in the step of preparing a silicone resin prepolymer having two or more silanol functional groups, it is preferable to add an organometallic compound catalyst such as dibutyltin dilaurate.

As such, the silicone-epoxy-vinyl resin according to the present invention has a methoxy silane group capable of reacting with silanol groups on the surface of silica, which is often used as a filler, and thus can be bonded through surface reactions. In addition, the methoxy silane group promotes bonding with a filler such as silver powder, thereby enabling synergistic improvement of physical properties. On the other hand, the vinyl group can be bonded through a radical reaction with the surface of the carbon fine particles, such as carbon nanotubes, graphene.

In addition, the manufacturing method of the silicone-epoxy-vinyl resin according to the present invention has an advantage of producing a composite adhesive excellent in bonding with the filler even without adding a surface treatment of the filler or a separate binder.

1 is a schematic view of preparing a silicone resin having four silanol functional groups through a sol-gel condensation reaction of a silane compound [TEOS] and a hydroxyl group-terminated polydimethyl silicone [OH-PDMS],
FIG. 2 is a reaction schematic diagram of adding an epoxy silane compound and a vinyl silane compound to a silicone resin having four silanol functional groups to prepare a silicone-epoxy-vinyl resin,
Figure 3 shows the formula (II) of the silane compound of the silicone-epoxy-vinyl resin according to the present invention,
4 is infrared spectra confirming the synthesis process of the silicon-epoxy-vinyl resin according to the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the accompanying drawings are only intended to describe the technical spirit of the present invention in more detail, and the technical spirit of the present invention is not limited thereto.

Hereinafter, the present invention will be described in detail.

1. Preparation of silicone compound (formula (I)) having silanol functional group of 2 or more

The present invention includes preparing a silicone compound having two or more silanol functional groups through a sol-gel reaction with an aqueous alkoxy silane and a hydroxyl-terminated polydimethyl siloxane. This step can be carried out by a condensation reaction method in a conventional nitrogen gas atmosphere. 1 shows schematically this step.

The present invention reacts the first silane compound with a hydroxyl group terminated silicone resin having a weight average molecular weight of 500 to 6000 to produce a water dispersion polyurethane prepolymer.

In the present invention, examples of the first silane compound include compounds such as tetrachloride silane and tetraethoxy silane.

In the present invention, as the silicone resin, hydroxyl-terminated polydimethylsiloxane (OH-PDMS) and silicone in which a part of the methyl group of OH-PDMS is substituted with a phenyl group or the like is preferably used.

In the present invention, the silicone resin may be used in the form of a single compound or a mixture, and the terminal functional groups of the silicone resin are not limited to hydroxyl groups, and include the functional groups capable of achieving the object of the present invention. It is not.

In the present invention, the above-mentioned silicone resin is preferably polydimethyl siloxane having a weight average molecular weight of 500 to 6000.

In addition, in the present invention, the amount of the reactant used is equal to the first silane compound: the hydroxyl group terminal silicone resin = 1: 2.0 to 1: 2.5, more preferably 1: 2.

When the usage-amount of said 1st silane compound: hydroxyl group terminal silicone is made to react in equivalence ratio within the range of 1: 2.0-1: 2.5, this invention will obtain the silicone resin prepolymer whose silanol functional group is 2 or more. This reaction can be carried out in a condensation reaction under a conventional nitrogen gas atmosphere, which is well illustrated in FIG. At this time, a representative example of the hydroxyl terminal terminal polyfunctional silicone resin obtained is represented by the formula (I). In the said general formula (I), n is the number of repeating units of the silicone resin of 6-80, and becomes a measure of molecular weight.

In the present invention, in the process of preparing the silicone prepolymer (I) having two or more silanol functional groups, volatile hydrogen chloride or ethanol is produced through the condensation reaction. As the reaction is completed, since the volatile hydrogen chloride or ethanol is no longer produced, it may be determined that the reaction is completed when there is no change in weight.

2. Preparation of Silane Epoxy Modifier (II)

The present invention includes preparing a silicone-epoxy-vinyl resin. 2 shows schematically this step.

The present invention reacts silicone prepolymer molecules having two or more silanol functional groups with a second silane compound and a third silane compound to produce a silicone-epoxy-vinyl resin and mixtures thereof. The second silane compound is preferably a silane compound containing an epoxy group, and the third silane compound is preferably a silane compound containing a vinyl group. While FIG. 2 illustrates these reaction processes, FIG. 3 illustrates a silicon-epoxy-vinyl resin (II) having a silanol functional group as a final product after the reaction process.

In the present invention, the second silane compound is a silane compound containing an epoxy group, for example, [2- (3,4-epoxycyclohexyl) ethyl] trimethoxysilane (ETCS) and glycidyl propyl trimethoxy silane (GPTMS) are preferably used. Do. The silane groups are intended to react with the silanol functional groups at the terminal of the silicone resin of the formula (I), and the epoxy groups consider adhesive strength, heat resistance, mechanical strength, and the like. In the present invention, the third silane compound is preferably a silane compound containing a vinyl group, such as 3- (trimethoxysilyl) propyl methacrylate (TMSMC). The silane groups are also intended to react with the silanol functional groups at the terminal of the silicone resin of the formula (I), and the vinyl groups may be bonded to carbon fine particles such as carbon nanotubes or graphene.

In the present invention, the reaction between the silicone prepolymer, the second silane compound and the third silane compound is in a molar ratio of 1: 1 to 4: 1 to 4, more preferably 1: 2 to 3: 2. It is in the range of 3. If the ratio is exceeded, a branched product is obtained and the molecular weight is increased so that the viscosity is high, which is disadvantageous for mixing with the filler, and the binding force to the filler is also weak.

<< production example >>

To the three necked flask, 50 grams of hydroxyl-terminated polydimethyl siloxane having a molecular weight of 1140 were added, followed by addition of 2.364 grams of tetraehoxy silane. 1000 ppm dibutyltin dilaurate was added as a catalyst, and then a condenser was attached, and the reaction was performed for 3 hours by raising the temperature to 80 ° C. in a nitrogen gas atmosphere. The reaction was allowed to proceed for 3 hours, and when no more condensate was released, vacuum was applied to complete the one-step condensation reaction.

For the two-step reaction, 5.48 grams of [2- (3,4-epoxycyclohexyl) ethyl] trimethoxysilane (ETCS) and 5.52 grams of 3- (trimethoxysilyl) propyl methacrylate (TMSMC) were added to the three-necked flask at 80 ° C. The reaction was carried out until the condensate due to condensation no longer occurred at and the final product was obtained.

In order to confirm the progress of the reaction according to the above production example and the synthesis of the silicon-epoxy-vinyl resin obtained after the completion of the reaction, the infrared spectrum was measured at each step. Infrared spectrometer used FT / IR-300E, JASCO Fourier Transform Infrared Spectrometer.

Figure 4a is an infrared spectrum showing the reaction result of the first step of the present invention. FIG. 4A shows the spectrum of hydroxyl group-terminated polydimethylsiloxane (OH PDMS) and tedhraethoxy silane (TEOS), which are the raw materials for the one-step reaction, and the spectrum of the product thereof in the infrared spectrum. In the spectrum of OH PDMS (black), the stretching vibration peak of Si-OH group is strong at 3294 cm ^-1 , and in the spectrum of TEOS (red), bending of ethoxy group CH bond at 1391 and 1169 cm ^-1 ( It can be seen that peaks of bending and rocking oscillations are observed. OH PDMS and TEOS in the spectrum (blue) of the reaction product also in the progress of the reaction shown in Figure 1 is a hydroxyl group peak intensity of the OH PDMS greatly reduced at 3294cm ^-1 and, ethoxy TEOS at 1391 and 1169 cm ^-1 characteristic peak group CH Almost disappeared, it can be seen that the reaction of Figure 1 proceeded.

Figure 4b is an infrared spectrum showing the reaction result of the second step of the present invention. 4B shows the ETCS and TMSMC spectra input for the two-step reaction with the one-step product peak below, and the change of the spectrum with the reaction time above. As shown in FIG. 2, the Si-OH peak intensity of OH-PDMS observed at the initial 3296 cm ⁻¹ decreased with time, and the characteristic peak of the epoxy ring structure was increased from 889 to 862 cm ⁻¹ with the introduction of ETCS. With the introduction of TMSMC, carbonyl and double bond characteristic peaks of the acryl group were observed at 1723 and 1638 cm ⁻¹ , respectively, to confirm product formation of formula (II).

Although the silicone-epoxy-vinyl resin adhesive and the manufacturing method according to the present invention have been described in detail above, this is only for describing the most preferred embodiment of the present invention, and the present invention is not limited thereto. The range is determined and defined by the range.

In addition, anyone of ordinary skill in the art will be able to make various modifications and imitations by the description of the specification of the present invention, but it will be apparent that this is also outside the scope of the present invention.

Claims (5)

a) sol-gel condensation reaction of polydimethylsiloxane having a terminal hydroxyl group having a weight average molecular weight of 500 to 6000 with tetrasilane or tetraethoxy silane to prepare a silicone resin prepolymer having two or more silanol groups;
b) [2- (3,4-epoxycyclohexyl) ethyl] trimethoxysilane (ETCS) with silicone resin prepolymer and epoxy group or glycidyl propyl trimethoxy silane (GPTMS) and 3- (trimethoxysilyl) propyl methacrylate with vinyl group TMSMC) to prepare a silicone epoxy modified body and mixtures thereof in which the hydroxyl groups of the silicone resin are replaced with epoxy and vinyl groups; Method for producing a silicon-epoxy-silicone resin compound comprising a.
delete The method of claim 1,
The amount of the [2- (3,4-epoxycyclohexyl) ethyl] trimethoxysilane (ETCS) or glycidyl propyl trimethoxy silane (GPTMS) compound and the 3- (trimethoxysilyl) propyl methacrylate (TMSMC) compound described above may be based on the molar ratio. When, silicone resin prepolymer: [2- (3,4-epoxycyclohexyl) ethyl] trimethoxysilane (ETCS) or glycidyl propyl trimethoxy silane (GPTMS) compound: 3- (trimethoxysilyl) propyl methacrylate (TMSMC) compound = 1: 1-3 : The manufacturing method of the silicone-epoxy-silicone resin compound characterized by the range of 1-3.
4. The silicone-epoxy-silicone resin compound according to claim 1 or 3, wherein the silicone epoxy modified body is represented by the following general formula (II).

However, in the formula (II), n is an integer of 6 to 80.
The method of claim 4, wherein
The silicon epoxy modified compound is a silicon-epoxy-silicone resin compound, characterized in that at least one epoxy group and a vinyl group is introduced per molecule.

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